Methylation of P16 and P15 Genes in Multiple Myeloma

Chinese Medical Sciences Journal = Chung-kuo I Hsüeh K'o Hsüeh Tsa Chih / Chinese Academy of Medical Sciences. Jun, 2002  |  Pubmed ID: 12906163

To investigate the frequency of p16 and p15 gene methylation in multiple myeloma (MM), and its relationship with bone marrow cell apoptosis and clinical outcome.

[Study on Angiogenesis of Multiple Myeloma in Vitro]

Zhongguo Shi Yan Xue Ye Xue Za Zhi / Zhongguo Bing Li Sheng Li Xue Hui = Journal of Experimental Hematology / Chinese Association of Pathophysiology. Aug, 2002  |  Pubmed ID: 12513764

Angiogenesis is a necessary step in tumor progression, and it correlates an unfavorable prognosis. In multiple myeloma, bone marrow microvessel density and angiogenesis grading correlated with plasma cell labeling index and are poor survival predictors, but the study of myeloma's angiogenesis is very rare. This article was to study the effect of multiple myeloma cell line conditioned media on the proliferation, migration and angiogenesis of human bone marrow endothelial cells (HBMEC). The multiple myeloma cell line conditioned media were obtained by using RPMI 1640 media containing 2% fetal bovine serum (FBS) to cultivate myeloma cell lines for 18 hours. Proliferation and migration of HBMEC were detected by using those media to cultivate HBMEC. Capillary tube formation was performed by using microcarriers cytodex-3 covered with HBMEC in three-dimensional fibrin matrices. The results showed that myeloma conditioned media induced HBMEC's proliferation and migration (P < 0.001), and those media induced capillary tube formation (length and width) of HBMEC (P < 0.001). It was concluded that myeloma cell lines induce HBMEC's proliferation, migration, and capillary tube formation by secreting several cytokines.

Stimulation of Na,K-ATPase by Low Potassium Requires Reactive Oxygen Species

American Journal of Physiology. Cell Physiology. Aug, 2003  |  Pubmed ID: 12686517

The signaling pathway that transduces the stimulatory effect of low K+ on the biosynthesis of Na,K-ATPase remains largely unknown. The present study was undertaken to examine whether reactive oxygen species (ROS) mediated the effect of low K+ in Madin-Darby canine kidney (MDCK) cells. Low K+ increased ROS activity in a time- and dose-dependent manner, and this effect was abrogated by catalase and N-acetylcysteine (NAC). To determine the role of ROS in low-K+-induced gene expression, the cells were first stably transfected with expression constructs in which the reporter gene chloramphenicol acetyl transferase (CAT) was under the control of the avian Na,K-ATPase alpha-subunit 1.9 kb and 900-bp 5'-flanking regions that have a negative regulatory element. Low K+ increased the CAT expression in both constructs. Catalase or NAC inhibited the effect of low K+. To determine whether the increased CAT activity was mediated through releasing the repressive effect or a direct stimulation of the promoter, the cells were transfected with a CAT expression construct directed by a 96-bp promoter fragment that has no negative regulatory element. Low K+ also augmented the CAT activity expressed by this construct. More importantly, both catalase and NAC abolished the effect of low K+. Moreover, catalase and NAC also inhibited low-K+-induced increases in the Na,K-ATPase alpha1- and beta1-subunit protein abundance and ouabain binding sites. The antioxidants had no significant effect on the basal levels of CAT activity, protein abundance, or ouabain binding sites. In conclusion, low K+ enhances the Na,K-ATPase gene expression by a direct stimulation of the promoter activity, and ROS mediate this stimulation and also low-K+-induced increases in the Na,K-ATPase protein contents and cell surface molecules.

Development of Cross-resistance Between Heat and Cisplatin or Hydroxyurea Treatments in FaDu Squamous Carcinoma Cells

The Journal of Surgical Research. May, 2003  |  Pubmed ID: 12842459

Induction of hyperthermia by radiofrequency ablation is gaining popularity in treating a variety of solid tumors. This study examined an impact of sublethal heat treatment interacted with chemotherapeutic drugs on the survival of head and neck squamous carcinoma cells using in vitro model.

Role of Transferrin in the Stimulation of Na,K-ATPase Induced by Low K+ in Madin Darby Canine Kidney Cells

Sheng Li Xue Bao : [Acta Physiologica Sinica]. Aug, 2003  |  Pubmed ID: 12937832

The presence of serum in a culture medium makes it impossible to identify whether changed cellular functions are directly caused by a manipulation itself or mediated by a component in serum. Madin Darby canine kidney cells can survive in a serum-free medium for about 48 h. We took this advantage to examine whether low K(+)-induced up-regulation of Na,K-ATPase requires serum. We found that serum was essential for low K(+) to induce an increase in Na,K-ATPase binding sites as quantified by ouabain factor binding assays. In an attempt to identify which component was critical, we screened EGF, IGF1, PGE1 and transferrin to identify which one can replace serum. We discovered that transferrin was the single most important factor that mimicked about 80% to 90% of the effect of serum. Transferrin potentiated the effect of low K(+) on the Na,K-ATPase binding sites in a time- and dose-dependent manner. Furthermore, transferrin was also required for low K(+)-induced increase in alpha(1)-promoter activity, alpha(1)- and beta(1)-subunit protein abundance of the Na,K-ATPase. In the presence of transferrin, low K(+) enhanced cellular uptake of iron approximately by 70%. Inhibition of intracellular iron activity by deferoxamine (30 micromol/L) abrogated the effect of low K(+). We conclude that stimulation of the Na,K-ATPase by low K(+) is critically dependent on transferrin. The effect of transferrin is mediated by increased iron transport.

Role of AMP-activated Protein Kinase in Cyclic AMP-dependent Lipolysis In 3T3-L1 Adipocytes

The Journal of Biological Chemistry. Oct, 2003  |  Pubmed ID: 12941946

AMP-activated protein kinase (AMPK) is a phylogenetically conserved intracellular energy sensor that has been implicated as a major regulator of glucose and lipid metabolism in mammals. However, its possible role in mediating or influencing the adrenergic control of lipolysis in adipocytes remains uncertain. In this study, we utilized the murine cultured preadipocyte line 3T3-L1 to examine this question. Treatment of adipocytes with isoproterenol or forskolin promoted the phosphorylation of AMPK at a critical activating Thr-172 residue in a dose- and time-dependent manner. This correlated well with a stimulation of the activity of AMPK, as measured in the immune complex. Analogs of cAMP mimicked the effect of isoproterenol and forskolin on AMPK phosphorylation. Treatment of adipocytes with insulin reduced both basal and forskolin-induced AMPK phosphorylation via a pathway dependent on phosphatidylinositol 3'-kinase. Overexpression of a dominant-inhibitory mutant of AMPK blocked isoproterenol-induced lipolysis by approximately 50%. These data indicate that there exists a novel pathway by which cAMP can lead to the activation of AMPK, and in adipocytes, this is required for maximal activation of lipolysis.

Analgesic and Anti-inflammatory Properties of Brucine and Brucine N-oxide Extracted from Seeds of Strychnos Nux-vomica

Journal of Ethnopharmacology. Oct, 2003  |  Pubmed ID: 12963144

To further understand the purpose of the traditional processing method of the seeds of Strychnos nux-vomica L. (Loganiaceae) as well as analgesic and anti-inflammatory activities of brucine and brucine N-oxide extracted from this medicinal plant, various pain and inflammatory models were employed in the present study to investigate their pharmacological profiles. Both brucine and brucine N-oxide revealed significant protective effects against thermic and chemical stimuli in hot-plate test and writhing test. However, on different phases they exerted analgesic activities in formalin test. Brucine N-oxide showed stronger inhibitory effect than brucine in carrageenan-induced rat paw edema, both of them significantly inhibited the release of prostaglandin E2 in inflammatory tissue, reduced acetic acid-induced vascular permeability and the content of 6-keto-PGF1a in Freund's complete adjuvant (FCA) induced arthritis rat's blood plasma. In addition, brucine and brucine N-oxide were shown to reduce the content of 5-hydroxytryptamine (5-HT) in FCA-induced arthritis rat's blood plasma, while increase the content of 5-hydroxytryindole-3-acetic acid (5-HIAA) accordingly. These results suggest that central and peripheral mechanism are involved in the pain modulation and anti-inflammation effects of brucine and brucine N-oxide, biochemical mechanisms of brucine and brucine N-oxide are different even though they are similar in chemical structure.

Protein Kinase A Potentiates Adrenal 4 Binding Protein/steroidogenic Factor 1 Transactivation by Reintegrating the Subcellular Dynamic Interactions of the Nuclear Receptor with Its Cofactors, General Control Nonderepressed-5/transformation/transcription Domain-associated Protein, and Suppressor, Dosage-sensitive Sex Reversal-1: a Laser Confocal Imaging Study in Living KGN Cells

Molecular Endocrinology (Baltimore, Md.). Jan, 2004  |  Pubmed ID: 14555713

The mechanism through which protein kinase A (PKA) potentiates the transactivation ability of adrenal 4 binding protein/steroidogenic factor 1 (Ad4BP/SF-1) is currently unclear. In the present study, we investigated the mechanism by applying laser confocal microscopy and fluorescence recovery after photobleaching technique. In KGN cells, forskolin (a PKA stimulator) could reorganize wild-type Ad4BP/SF-1, but not mutant Ad4BP/SF-1 (G35E), from a diffuse distribution pattern to foci formation in the nucleus. The subcellular distributions of GCN5 (general control nonderepressed) and TRRAP (transformation/transcription domain-associated protein), both of which were recently proved to be working in the same complex as the third class of nuclear receptor coactivators, were unexpectedly diffuse inside and outside the nucleus, respectively, when they were separately transfected. However TRRAP was translocated into the nucleus in the presence of GCN5, and together with GCN5 colocalized with Ad4BP/SF-1 in the same foci when PKA was activated. A luciferase assay also indicated that these two cofactors enhanced Ad4BP/SF-1 transactivation.Dosage-sensitive sex reversal (DAX-1) interacts with and thus inhibits Ad4BP/SF-1 transactivation. The coexistence of the two proteins dramatically altered their respective subnuclear distributions. They colocalized extensively, suggestive of binding, and Ad4BP/SF-1 was sharply immobilized when DAX-1 was coexpressed, whereas PKA could maintain mobility, as evidenced by Fluorescence Recovery After Photobleaching showing that Ad4BP/SF-1 mobility recovered after forskolin treatment.Therefore, the PKA signal pathway may modify the interaction between Ad4BP/SF-1 and its activators and repressor (GCN5 and TRRAP are integrated, whereas DAX-1 is disassociated), and thus stimulate the Ad4BP/SF-1 transactivation.

PD-L1-deficient Mice Show That PD-L1 on T Cells, Antigen-presenting Cells, and Host Tissues Negatively Regulates T Cells

Proceedings of the National Academy of Sciences of the United States of America. Jul, 2004  |  Pubmed ID: 15249675

Both positive and negative regulatory roles have been suggested for the B7 family member PD-L1(B7-H1). PD-L1 is expressed on antigen-presenting cells (APCs), activated T cells, and a variety of tissues, but the functional significance of PD-L1 on each cell type is not yet clear. To dissect the functions of PD-L1 in vivo, we generated PD-L1-deficient (PD-L1(-/-)) mice. CD4(+) and CD8(+) T cell responses were markedly enhanced in PD-L1(-/-) mice compared with wild-type mice in vitro and in vivo. PD-L1(-/-) dendritic cells stimulated greater wild-type CD4(+) T cell responses than wild-type dendritic cells, and PD-L1(-/-) CD4(+) T cells produced more cytokines than wild-type CD4(+) T cells in vitro, demonstrating an inhibitory role for PD-L1 on APCs and T cells. In vivo CD8(+) T cell responses also were significantly enhanced, indicating that PD-L1 has a role in limiting the expansion or survival of CD8(+) T cells. Studies using the myelin oligodendrocyte model of experimental autoimmune encephalomyelitis showed that PD-L1 on T cells and in host tissues limits responses of self-reactive CD4(+) T cells in vivo. PD-L1 deficiency converted the 129S4/SvJae strain from a resistant to experimental autoimmune encephalomyelitis-susceptible strain. Transfer of encephalitogenic T cells from wild-type mice into PD-L1(-/-) recipients led to exacerbated disease. Disease was even more severe in PD-L1(-/-) recipients of PD-L1(-/-) T cells. These results demonstrate that PD-L1 on T cells, APCs, and host tissue inhibits naïve and effector T cell responses and plays a critical role in T cell tolerance.

Activation of Protein Kinase A Alters Subnuclear Distribution Pattern of Human Steroidogenic Factor 1 in Living Cells

Chinese Medical Journal. Jul, 2004  |  Pubmed ID: 15265375

The aim of this study was to identify the subnuclear distribution pattern of human orphan nuclear receptor steroidogenic factor 1 (SF-1) in living cells with and without the activation of protein kinase A (PKA) signal pathway, and thus try to explain the unknown mechanism by which PKA potentiates SF-1 transactivation.

Self-assembled Biomimetic Monolayers Using Phospholipid-containing Disulfides

Biomaterials. May, 2005  |  Pubmed ID: 15585234

Several phospholipid-based disulfide molecules were synthesized and attached onto the gold-coated silicon wafer using the self-assembling method. The syntheses of these surface-modifying agents were conducted by introducing bromoethylphosphorate (PBr), phosphorylcholine (PC) or phosphorylethanolamine (PE) groups on the terminals of a dialkyl disulfide. After disulfides adsorption onto gold substrate surfaces, the composition, the film thickness, and the conformational order of self-assembled monolayer surfaces were explored and discussed in detail based on reflection-absorption infrared spectroscopy, contact angle measurement, Auger electron spectroscopy, X-ray photoelectron spectroscopy, and so on. The monolayer having the PBr end group could also be converted to a PC surface by treating with trimethylamine. The model functional surfaces of Au-SC11-PC, -PE, -PBr, -OH or corresponding mixed layers were used to mimic biomembrane surfaces. The monolayer having PC groups was found to reduce fibrinogen adsorption as evaluated from protein adsorption experiments using quartz crystal microbalance. It also showed relatively low platelet adherence compare to the glass, PBr and PE surfaces. The cell viability test also revealed that the PC surface displayed lower cytotoxicity than other surfaces.

Tob Proteins Suppress Steroid Hormone Receptor-mediated Transcriptional Activation

Molecular and Cellular Endocrinology. Jan, 2005  |  Pubmed ID: 15664454

Although sex steroid hormones have significant effects on bone metabolism, the molecular mechanisms of these actions have not been fully elucidated yet. We examined the functional relationship between steroid hormone receptors and Tob, a member of an anti-proliferative protein family and a negative regulator of osteoblast proliferation and differentiation. Luciferase assay using promoters carrying hormone-responsive elements revealed that both Tob1 and Tob2 proteins but not PC3 suppressed steroid hormone receptor-dependent transcriptional activation in MC3T3-E1 osteoblastic cells. Mutated Tob proteins carrying amino acid substitutions at an LXXLL motif also showed the same degree of inhibition of the transcriptional activation as the wild type. By observation of androgen receptor (AR)-tagged with green fluorescent protein under a confocal laser scanning microscope, we found that Tob1 inhibits the nuclear foci formation of dihydrotestosterone-bound AR. These results indicate that Tob family proteins may negatively regulate sex steroid hormone action in bone formation.

Stent-based Delivery of Tissue Inhibitor of Metalloproteinase-3 Adenovirus Inhibits Neointimal Formation in Porcine Coronary Arteries

Arteriosclerosis, Thrombosis, and Vascular Biology. Apr, 2005  |  Pubmed ID: 15681295

Stent-based antiproliferative therapy appears to decrease in-stent restenosis. However, alternative approaches might produce equivalent efficacy with better long-term safety. In previous work, an adenovirus capable of expressing the tissue inhibitor of metalloproteinase-3 (RAdTIMP-3) inhibited neointima formation in cell cultures and porcine saphenous vein grafts. RAdTIMP-3 decreased smooth muscle cell migration, stabilized the extracellular matrix, and uniquely promoted apoptosis. The current study developed eluting stent technology to deliver RAdTIMP-3 during stenting of pig coronary arteries.

Uniform, Axial-orientation Alignment of One-dimensional Single-crystal Silicon Nanostructure Arrays

Angewandte Chemie (International Ed. in English). Apr, 2005  |  Pubmed ID: 15812791

Impaired Nuclear Translocation, Nuclear Matrix Targeting, and Intranuclear Mobility of Mutant Androgen Receptors Carrying Amino Acid Substitutions in the Deoxyribonucleic Acid-binding Domain Derived from Androgen Insensitivity Syndrome Patients

The Journal of Clinical Endocrinology and Metabolism. Nov, 2005  |  Pubmed ID: 16118342

Recent imaging studies revealed that androgen receptor (AR) is ligand-dependently translocated from the cytoplasm into the nucleus and forms intranuclear fine foci. In this study, we examined whether intracellular dynamics of mutant ARs detected in two androgen insensitivity syndrome (AIS) patients was impaired.

[Tropism of Adult Liver Stem Cells Toward Hepatocellular Carcinoma Cells in Vitro]

Zhonghua Gan Zang Bing Za Zhi = Zhonghua Ganzangbing Zazhi = Chinese Journal of Hepatology. Sep, 2005  |  Pubmed ID: 16174449

To explore the biological behavior of adult liver stem cells in a co-cultured system of them with hepatocellular carcinoma (HCC) cells without direct contact between the two kinds of cells.

Aligned Single-crystalline Si Nanowire Arrays for Photovoltaic Applications

Small (Weinheim an Der Bergstrasse, Germany). Nov, 2005  |  Pubmed ID: 17193395

Diffusion Tensor MRI Study of Myocardium Structural Remodeling After Infarction in Porcine Model

Conference Proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference. 2006  |  Pubmed ID: 17946019

Investigation of infarct myocardium structure will lead to better understanding of functional adaptation and remodeling. Diffusion tensor magnetic resonance imaging (DTI) provides a means for rapid and nondestructive characterization of the three-dimensional fiber architecture of myocardium. DTI studies were performed on 10 excised, formalin-fixed hearts of both infarct (two months after left anterior descending coronary artery (LAD) occlusion surgery, n=4) and control (n=6) porcine. Each slice was divided into eight segments, and fractional anisotropy (FA) value and helix angle were measured in multiples short-axis slices, respectively. Infarct myocardium exhibited decreased FA value, flatter helix angle courses fluctuating around small helix angle with greater standard error of the mean (SEM) and smaller range of helix angle. The results provide structure information of infarct myocardium.

The Anti-tumor Effects of Alkaloids from the Seeds of Strychnos Nux-vomica on HepG2 Cells and Its Possible Mechanism

Journal of Ethnopharmacology. Jun, 2006  |  Pubmed ID: 16442763

To screen the anti-tumor effects of the four alkaloids: brucine, strychnine, brucine N-oxide and isostrychnine from the seed of Strychnos nux-vomica, MTT assay was used to examine the growth inhibitory effects of these alkaloids on human hepatoma cell line (HepG2). Brucine, strychnine and isostrychnine revealed significant inhibitory effects against HepG2 cell proliferation, whereas brucine N-oxide didn't have such an effect. In addition, brucine caused HepG2 cell shrinkage, membrane blebbing, apoptotic body formation, all of which are typical characteristics of apoptotic programmed cell death. The results of flow cytometric analysis demonstrated that brucine caused dose-dependent apoptosis of HepG2 cells through cell cycle arrest at G0/G1 phase, thus preventing cells entering S or G2/M phase. Immunoblot results revealed that brucine significantly decreased the protein expression level of cyclooxygenase-2, whereas increased the expression caspase-3 as well as the caspase-3-like protease activity in HepG2 cells, suggesting the involvement of cyclooxygenase-2 and caspase-3 in the pro-apoptotic effects exerted by brucine. Therefore, this paper indicate that the major alkaloids present in the seed of Strychnos nux-vomica are effective against HepG2 cells proliferation, among which brucine proceed HepG2 cells death via apoptosis, probably through the participation of caspase-3 and cyclooxygenase-2.

The Apoptotic Effect of Brucine from the Seed of Strychnos Nux-vomica on Human Hepatoma Cells is Mediated Via Bcl-2 and Ca2+ Involved Mitochondrial Pathway

Toxicological Sciences : an Official Journal of the Society of Toxicology. May, 2006  |  Pubmed ID: 16443926

In an attempt to dissect the mechanism of Strychnos nux-vomica, a commonly used Chinese folk medicine in the therapy of liver cancer, the cytotoxic effects of four alkaloids in Strychnos nux-vomica, brucine, brucine N-oxide, strychnine, and isostrychnine, on human hepatoma cells (HepG2) were screened by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrasolium bromide (MTT) assay. Brucine, among the four alkaloids, exhibited the strongest toxic effect, the mechanism of which was found to cause HepG2 cell apoptosis, since brucine caused HepG2 cell shrinkage, the formation of apoptotic bodies, DNA fragmentation, cell cycle arrest, as well as phosphatidylserine externalization, all of which are typical characteristics of apoptotic programmed cell death. Brucine-induced HepG2 cell apoptosis was caspase dependent, with caspase-3 activated by caspase-9. Brucine also caused the proteolytic processing of caspase-9. In addition, brucine caused depolarization of the mitochondrial membrane of HepG2 cells, the inhibition of which by cyclosporine A completely abrogated the activation of casapses and release of cytochrome c in brucine-treated HepG2 cells. These findings suggested a pivotal role of mitochondrial membrane depolarization in HepG2 cell apoptosis elicited by brucine. Furthermore, brucine induced a rapid and sustained elevation of intracellular [Ca2+], which compromised the mitochondrial membrane potential and triggered the process of HepG2 cell apoptosis. Finally, Bcl-2 was found to predominately control the whole event of cell apoptosis induced by brucine. The elevation of [Ca2+]i caused by brucine was also suppressed by overexpression of Bcl-2 protein in HepG2 cells. From the facts given above, Ca2+ and Bcl-2 mediated mitochondrial pathway were found to be involved in brucine-induced HepG2 cell apoptosis.

Testicular Zinc Finger Protein Recruits Histone Deacetylase 2 and Suppresses the Transactivation Function and Intranuclear Foci Formation of Agonist-bound Androgen Receptor Competitively with TIF2

Molecular and Cellular Endocrinology. Mar, 2006  |  Pubmed ID: 16469430

We previously reported that testicular zinc finger protein (TZF) is a corepressor for androgen receptor (AR). The present study demonstrated that a central portion (amino acids 512-663) of TZF, TZF(512-663), is responsible for both binding to AR and repressing the transactivation. TZF recruited endogenous histone deacetylase 2 (HDAC2) and formed a complex with agonist-bound AR. Imaging analyses showed that TZF and TZF(512-663) were recruited by AR and simultaneously impaired distinct AR foci formation. Quantification of the foci number using a three-dimensional imaging method revealed that the number of intranuclear AR foci was related to its transactivation activity. Moreover, increased levels of TZF dissociated a coactivator, TIF2, from the AR foci and vice versa. These results indicate that the ligand-dependent transactivation function of AR is quantitatively related to its intranuclear foci formation, and suggest that corepressors, such as TZF, act on these intranuclear events competitively with coactivators.

Comparison of Gene Expression Profiles in Mouse Primary T Cells Under Normal and Prolonged Activation

Blood Cells, Molecules & Diseases. Jul-Aug, 2006  |  Pubmed ID: 16740399

In order to investigate the global transcriptional change of mouse primary T cells after prolonged activation, we took advantage of a Mouse Genome 430 2.0 Array to assess and compare the overall gene expression profiles of mouse T cells after activated with anti-CD3/CD28 for 18 or 48 h. The results demonstrated that most activation-related genes were preferentially up-regulated in mouse primary T cells after stimulated for 18 h; some apoptotic genes, however, were also found to be moderately up-regulated simultaneously. After the activation of T cells for 48 h, lots of apoptosis-related genes were dramatically up-regulated, followed by the augmentation of activation-induced cell death. In general, the number of differentially expressed genes in T cells after activation over 48 h declined almost in half as compared to that of 18 h. Both microarray and cytokine content analyses revealed that Th1 cytokines, rather than Th2 cytokines, were specifically up-regulated in activated mouse primary T cells. The present study also identified a number of genes that were dramatically up or down-regulated in T cells activated for 48 h for the first time, although the exact functions of these proteins are not known. Our studies provide detailed information on genes expression profiles of mouse primary T cells after normal (18 h) and prolonged activation (48 h); these data may accelerate the understanding of the T cell activation process and offer clues to the therapy of immune diseases.

Metal-particle-induced, Highly Localized Site-specific Etching of Si and Formation of Single-crystalline Si Nanowires in Aqueous Fluoride Solution

Chemistry (Weinheim an Der Bergstrasse, Germany). Oct, 2006  |  Pubmed ID: 16871502

A straightforward metal-particle-induced, highly localized site-specific corrosion-like mechanism was proposed for the formation of aligned silicon-nanowire arrays on silicon in aqueous HF/AgNO3 solution on the basis of convincing experimental results. The etching process features weak dependence on the doping of the silicon wafers and, thus, provides an efficient method to prepare silicon nanowires with desirable doping characteristics. The novel electrochemical properties between silicon and active noble metals should be useful for preparing novel silicon nanostructures and also new optoelectronic devices.

Survivin Nuclear Labeling Index: a Superior Biomarker in Superficial Urothelial Carcinoma of Human Urinary Bladder

Modern Pathology : an Official Journal of the United States and Canadian Academy of Pathology, Inc. Nov, 2006  |  Pubmed ID: 16892011

The caspase family proteases are key proapoptotic proteins while the inhibitor of apoptosis proteins (IAP) prevent apoptosis by antagonizing the caspases or other key proapoptotic proteins. Limited studies of IAPs suggested their deregulation contributed to urothelial neoplasia. However, the expression status and biologic or prognostic significance of the caspase and IAP family proteins in urothelial neoplasms is not clear. In the present study, we first systematically evaluated the expression profile of the major apoptosis regulators, including caspases (CASP3, 6, 7, 8, 9, 10, and 14), IAPs (survivin/BIRC5, CIAP1, CIAP2, XIAP, and LIVIN), APAF1, SMAC, and BCL2, as well as proliferation markers Ki67 and PHH3, in Ta/T1 human urinary bladder urothelial carcinomas and normal urothelium samples by immunohistochemistry. The analysis showed that survivin/BIRC5 nuclear labeling index (BIRC5-N), but not cytoplasmic staining, was the only apoptotic marker which correlated significantly with tumor grade, stage, and patient outcome. We further analyzed the prognostic value of BIRC5-N in 101 Ta/T1 urinary bladder urothelial carcinomas by univariate analysis, which showed that BIRC5-N as well as the more classical prognosticators (stage, grade, and Ki67 index) were of prognostic significance. However, multivariate analysis by Cox proportional hazard regression demonstrated BIRC5-N was a stronger prognosticator than tumor grade, stage, and Ki67 labeling index. BIRC5-N index of 8% or more predicted unfavorable disease-specific survival (relative risk (RR)=6.6, 95% confidence interval=1.6-26.7, P=0.0080) as well as progression-free survival (RR=4.4, 95% confidence interval=1.3-14.6, P=0.0151). We conclude that BIRC5-N is a superior biologic and prognostic marker for Ta/T1 urothelial carcinomas of urinary bladder.

Nuclear Compartmentalization of N-CoR and Its Interactions with Steroid Receptors

Molecular and Cellular Biology. Sep, 2006  |  Pubmed ID: 16914745

The repression mechanisms by the nuclear receptor corepressor (N-CoR) of steroid hormone receptor (SHR)-mediated transactivation were examined. Yellow fluorescent protein (YFP)-N-CoR was distributed as intranuclear discrete dots, while coexpression of androgen receptor (AR), glucocorticoid receptor alpha, and estrogen receptor alpha ligand-dependently triggered redistribution of YFP-N-CoR. In fluorescence recovery after photobleaching analysis, mobility of the N-CoR was reduced by 5alpha-dihydrotestosterone (DHT)-bound AR. The middle region of N-CoR mostly contributed to the interaction with agonist-bound SHRs and the suppression of their transactivation function. N-CoR impaired the DHT-induced N-C interaction of AR, and the impaired interaction was dose-dependently recovered by coexpression of SRC-1 and CBP. N-CoR also impaired the intranuclear complete (distinct) focus formation of SHRs. Coexpression of SRC-1 or CBP released YFP-N-CoR or endogenous N-CoR from incomplete foci and simultaneously recovered complete foci of AR-green fluorescent protein. These results indicate that the relative ratio of coactivators and corepressors determines the conformational equilibrium between transcriptionally active and inactive SHRs in the presence of agonists. The intranuclear foci formed by agonist-bound SHRs were completely destroyed by actinomycin D and alpha-amanitin, indicating that the focus formation does not precede the transcriptional activation. The focus formation may reflect the accumulation of SHR/coactivator complexes released from the transcriptionally active sites and thus be a mirror of transcriptionally active complex formation.

Screening of Single-chain Variable Fragments Against TSP50 from a Phage Display Antibody Library and Their Expression As Soluble Proteins

Journal of Biomolecular Screening. Aug, 2006  |  Pubmed ID: 16928985

A novel gene, testes-specific protease 50 (TSP50), is abnormally activated and differentially expressed in most patients with breast cancer, suggesting it as a novel biomarker for this disease. The possibility that TSP50 may be an oncogene is presently under investigation. In this study, the single-chain variable fragments (scFvs) against TSP50 were panned from a phage display antibody library using TSP50-specific peptide, pep-50, as a target antigen. After 4 rounds of panning, 3 clones (A1, A11, and C8) from the library were verified to show strong binding affinities for TSP50 by enzyme-linked immunosorbent assay (ELISA) and to contain the variable region genes of the light and heavy chains of scFv antibodies but different complementary determining regions by sequencing. The genes of scFv-A1 and scFv-A11 were cloned into expression vector pPELB and successfully expressed as a soluble protein inEscherichia coli Rosetta. The yields of expressions were about 4.0 to 5.0 mg of protein from 1 L of culture. The expressed proteins were purified by a 2-step procedure consisting of ion-exchange chromatography, followed by immobilized metal affinity chromatography. The purified proteins were shown a single band at the position of 31 KDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Sandwich ELISA demonstrated that the expressed scFv proteins were able to specifically react with pep-50, laying a foundation for the investigation of the function of TSP50 in the development and treatment of breast cancer.

Apoptosis and Proliferation Markers in Diffusely Infiltrating Astrocytomas: Profiling of 17 Molecules

Journal of Neuropathology and Experimental Neurology. Sep, 2006  |  Pubmed ID: 16957584

Caspases and inhibitor of apoptosis proteins (IAPs) are antagonizing key apoptosis regulators. Limited studies of a few IAPs indicated their roles in astrocytomas. However, the overall expression status and significance of apoptosis regulators in astrocytomas is not clear. We examined the expression profile of the caspases (CASP3, 6, 7, 8, 9, 10, and 14), APAF1, SMAC, BCL2, the IAPs (BIRC5/survivin, CIAP1, CIAP2, XIAP, and LIVIN), and the proliferation markers Ki67 and PHH3 in 78 diffusely infiltrating astrocytomas and 24 normal brain samples by immunohistochemistry. Western blotting for major caspases and IAPs and reverse transcription-polymerase chain reaction analyses for IAPs were performed on a subset of 27 fresh samples. Our data showed BIRC5 nuclear labeling index (BIRC5-N) was the apoptosis marker most significantly different in World Health Organization grade II to IV astrocytomas and most strongly associated with proliferative activity. Expression level of other apoptosis-related proteins was modest or low in astrocytomas and did not correlate significantly with tumor grade or proliferation. Apoptosis regulators and proliferation markers were not detected in astrocytes of normal brain by immunostaining. This expression profile suggested involvement of apoptosis regulators in astrocytoma tumorigenesis, but tumor progression was more closely associated with proliferative advantages of which BIRC5 nuclear expression appeared to be a manifestation.

A Simple and Fast Experimental Model of Myocardial Infarction in the Mouse

Texas Heart Institute Journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital. 2006  |  Pubmed ID: 17041683

In this report, we describe a simple and fast method for creating a murine myocardial infarction model and providing a useful and convenient tool for the research in ischemic heart disease. We established acute myocardial infarction in the Kunming-strain mouse within 2 minutes by ligating the left anterior descending coronary artery. The model was evaluated by observing the changes in histology and in the serum levels of aspartate aminotransferase and lactate dehydrogenase. Obvious myocardial necrosis was found in the 24-hr experimental (ligation) group. The average size of the infarction was 44.3% +/- 2.9% of the left ventricle. Serum levels of aspartate aminotransferase and lactate dehydrogenase reached their peak in the 24-hr experimental group and were normal in the 72-hr experimental group. We set forth a simple and quick method for producing acute myocardial infarction experimentally in the mouse. The model can be reproduced in a stable manner, under experimental conditions that are easy to duplicate.

[Analysis of Cholesterol Ester Transfer Protein Gene Taq IB and -629 C/A Polymorphisms in Patients with Endogenous Hypertriglyceridemia in Chinese Population]

Zhonghua Yi Xue Yi Chuan Xue Za Zhi = Zhonghua Yixue Yichuanxue Zazhi = Chinese Journal of Medical Genetics. Dec, 2006  |  Pubmed ID: 17160943

To investigate the variations of cholesterol ester transfer protein (CETP) gene and its relation to endogenous hypertriglyceridemia (HTG) in Chinese population.

[Dissolved Oxygen on the Respiratory and Red Blood Cell Characteristic in Rainbow Trout (Oncorhynchus Mykiss)]

Zhongguo Ying Yong Sheng Li Xue Za Zhi = Zhongguo Yingyong Shenglixue Zazhi = Chinese Journal of Applied Physiology. Nov, 2006  |  Pubmed ID: 21155260

In Vivo MR Coronary Artery Imaging in Mice

Conference Proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference. 2007  |  Pubmed ID: 18003010

In vivo coronary artery imaging remains technically difficult in mice and only a few studies have been reported so far. 3D method is usually time-consuming and presents a practical limitation for MRI study of coronary arteries in mouse models of various cardiovascular diseases. The current study aims to develop a rapid and robust 2D procedure to visualize both LCA and RCA of mice in vivo. In addition, contrast agent of Gd-DPTA by rapid intraperitoneal (i.p.) injection was examined for its ability to improve the quality of LCA and RCA visualization. The current study demonstrated the feasibility of rapid MRI examination of coronary arteries of mice in vivo using 2D method and i.p. injection of contrast agent.

[Comparative Study on the Clinical Efficacy and Safety of Inhaled Corticosteroid Combined with Slow-release Theophylline Compared to Seretide in the Control of Asthma in Children]

Zhonghua Er Ke Za Zhi. Chinese Journal of Pediatrics. Oct, 2007  |  Pubmed ID: 18211767

Polyethylenimine-complexed Plasmid Particles Targeting Focal Adhesion Kinase Function As Melanoma Tumor Therapeutics

Molecular Therapy : the Journal of the American Society of Gene Therapy. Mar, 2007  |  Pubmed ID: 17285141

Focal adhesion kinase (FAK) is a non-receptor protein tyrosine kinase implicated in cell cycle progression and cell migration. Overexpression of FAK in a variety of tumors has suggested that FAK is a promising target for therapeutic intervention. In this study, we took advantage of a modified polyethylenimine (M-PEI) with high transfection efficiency for tumor cells and tissues, and targeted FAK function through both in vitro and in vivo approaches. The results demonstrated that both plasmid-encoded FAK small interfering RNA (siRNA) and overexpression of FAK-related non-kinase (FRNK, FAK dominant negative) dramatically inhibited in vitro B16F10 cell proliferation and invasion. We used two transplantable mouse tumor models of primary and metastatic melanoma to evaluate the therapeutic potential of PEI-complexed plasmids targeting FAK function. The results revealed that intratumoral delivery of PEI-complexed plasmids targeting FAK significantly suppressed primary tumor growth as well as metastasis of B16F10 cells into lung and lymph nodes. Both approaches prolonged the survival of the tumor-bearing mice. Taken together, these results indicate that intratumoral delivery of plasmid DNA targeting FAK function, using M-PEI as a gene carrier, represents a promising avenue for melanoma therapy.

The Matrix Metalloproteinases As Pharmacological Target in Osteoarthritis: Statins May Be of Therapeutic Benefit

Medical Hypotheses. 2007  |  Pubmed ID: 17360129

Osteoarthritis (OA) is a common joint disease; however, current pharmacologic agents for OA are only symptomatic and they can not prevent the disease progression. Matrix metalloproteinases (MMPs) produced by chondrocytes play an important role in the development of cartilage destruction in OA, and agents that can target against MMPs activity may be of therapeutical value. There were reports that statins can inhibit the secretion of MMPs in vitro and in vivo, which were believed to account for the plaque stabilizing effects of statins in the treatment of atherosclerosis. We based our hypothesis on that atherosclerosis possesses some aspects that are similar to that of osteoarthritis, such as inflammation and matrix degradation. Since statins have displayed great benefits in modifying the progression of atherosclerosis via anti-inflammatory and matrix-stabilizing mechanisms, it is conceivable that statins may also prevent the disease progression of osteoarthritis. Further work are needed to verify if statins can protect cartilage from destruction through inhibition of MMP secretion by chondrocytes, and their potential to be used as therapeutic agents in OA should be investigated.

Sinomenine Inhibits Primary CD4+ T-cell Proliferation Via Apoptosis

Cell Biology International. Aug, 2007  |  Pubmed ID: 17383204

Sinomenine is an active component isolated from Sinomenium acutum and is widely used as an immunosuppressive drug for treating autoimmune diseases. CD4(+) T-cell population plays a key role in adaptive immune response and is related to some autoimmune diseases. In this study, we investigated the possible immunosuppressive effect of sinomenine on CD4(+) T cells and its underlying mechanism. Our data demonstrated that sinomenine remarkably suppressed the proliferation of CD4(+) T cells, blocked the cell cycle progression from G0/G1 phase to S plusG2/M phases. Finally, the immunosuppressive activity elicited by sinomenine in CD4(+) primary lymphocytes was found to be largely accounted for by caspase 3-dependent cells apoptosis. Sinomenine did not significantly alter the expression of bcl-2 in activated CD4(+) primary T cells, suggesting that bcl-2 might not be involved in sinomenine-induced T cells apoptosis. In sum, this study proposes a novel mechanism for the immunosuppressive function of sinomenine on primary mouse CD4(+) T cells.

Anti-hypertensive Effects of Laiju Extract in Two Different Rat Models

Asia Pacific Journal of Clinical Nutrition. 2007  |  Pubmed ID: 17392125

The aim of the study was to evaluate whether laiju extract (LJE) from Semen Raphani and Flos Chrysanthemi has an anti-hypertensive effect in renal hypertensive rat (RHR) and spontaneous hypertensive rat (SHR). LJE was prepared by extracting dried Semen Raphani and Flos Chrysanthemi with 70% ethanol. RHR and SHR models were prepared by standard methods. Forty RHRs and 40 SHRs were randomly divided into high LJE (300 mg/kg), moderate LJE (200 mg/kg), low LJE (100 mg/kg) and saline control four groups (n=10), respectively. Compared with saline control, blood pressure was significantly lowered at 6 and 5 hours in high and moderate LJE respectively in both RHR and SHR groups. However, blood pressure was significantly lowered at 2 and 3 hours in low LJE in both RHR and SHR groups, respectively. Compared with saline control, blood pressure remained significantly lower in SHR in all dosage groups with a single daily dose for 28 days of study. LJE has potential in the prevention management of hypertension. Further studies are needed to identify the active chemical constituents and mechanisms of action of LJE.

[Analysis of ATP Binding Cassette A1 Gene R219K Polymorphism in Patients with Endogenous Hypertriglyceridemia in Chinese Population]

Zhonghua Yi Xue Yi Chuan Xue Za Zhi = Zhonghua Yixue Yichuanxue Zazhi = Chinese Journal of Medical Genetics. Apr, 2007  |  Pubmed ID: 17407076

To investigate the variations of ATP binding cassette A1 (ABCA1) gene and its relation to endogenous hypertriglyceridemia (HTG) in Chinese population.

The Cytotoxicity Induced by Brucine from the Seed of Strychnos Nux-vomica Proceeds Via Apoptosis and is Mediated by Cyclooxygenase 2 and Caspase 3 in SMMC 7221 Cells

Food and Chemical Toxicology : an International Journal Published for the British Industrial Biological Research Association. Sep, 2007  |  Pubmed ID: 17449162

To study the cytotoxicity of four alkaloids: brucine, strychnine, brucine N-oxide and isostrychnine from nux vomica on SMMC 7721 cells and their possible mechanisms, MET assay was used to examine the growth inhibitory effects of these alkaloids. Brucine revealed the strongest growth inhibitory effect on SMMC-7721 cells. Furthermore, as directly observed under an inverted microscope, fluorescent microscope and transmission electronic microscope, brucine caused SMMC-7721 cell shrinkage, membrane blobbing, formation of apoptotic body as well as nucleus condensation, all of which are typical characteristics of apoptotic programmed cell death. In addition, brucine dose-dependently caused SMMC-7721 cells apoptosis via formation of subdipolid DNA and phosphatidylserine externalization, as evidenced by flow cytometry analysis. The brucine-induced apoptosis was partially attributed to the activation of caspase 3 as well as cyclooxygenase 2 inhibition, since neither caspase 3 specific inhibitor, z-DEVD-fmk nor was exogenous addition of prostaglandin E(2) able to completely abrogate the brucine-induced SMMC 7721 cell apoptosis. In sum, this paper indicate that the major alkaloids present in the seed of Strychnos nux-vomica are effective against SMMC-7721 cells proliferation, among which brucine proceeds SMMC-7721 cells death via apoptosis, probably through the participation of caspase 3 and cyclooxygenase 2.

[Effects of Starvation and Re-feeding on Carbohydrate Metabolism of Marsupenaeus Japonicus]

Ying Yong Sheng Tai Xue Bao = The Journal of Applied Ecology / Zhongguo Sheng Tai Xue Xue Hui, Zhongguo Ke Xue Yuan Shenyang Ying Yong Sheng Tai Yan Jiu Suo Zhu Ban. Mar, 2007  |  Pubmed ID: 17552216

This paper studied the variations of glucose concentration in haemolymph and glycogen concentration in hepatopancreas and muscle of Marsupenaeus japonicus under starvation and re-feeding. Groups C, S1, S2 and S3 were deprived of food for 0, 10, 15 and 25 days, respectively, and then re-fed for 10 days. Under starvation, the glucose concentration in haemolymph and glycogen concentration in hepatopancreas decreased rapidly at the beginning, and the glycogen concentration in muscle was the lowest after 10-day fasting. In the following 5 days, the glucose concentration in haemolymph and glycogen concentration in hepatopancreas and muscle recovered to their initial levels due to gluconeogenesis, but the glycogen concentration kept declining with fasting. After refeeding, the glycogen concentration in hepatopancreas and muscle recovered well, and the glucose concentration in haemolymph had a sharper increase in groups S1 and S2 than in group C, but was markedly less in group S3 than in group C. These results indicated that long-term starvation had a greater effect on the glucose concentration in haemolymph.

Mutual Transactivational Repression of Runx2 and the Androgen Receptor by an Impairment of Their Normal Compartmentalization

The Journal of Steroid Biochemistry and Molecular Biology. Jun-Jul, 2007  |  Pubmed ID: 17627815

Steroid hormones play important roles not only in the reproductive system but also in bone metabolism. We examined the functional relationship between steroid hormone receptors and the Runx2 transcription factor that is essential for osteoblast differentiation and proliferation. A functional reporter assay using promoters carrying steroid hormone-responsive elements revealed that Runx2 suppressed ligand-dependent transcriptional activation mediated by receptors. To examine intracellular localization of these proteins, a three-dimensional imaging study was performed by laser scanning confocal microscopy of green fluorescent protein (GFP)-fused proteins. As previously reported, ligand-bound human androgen receptor (AR) was translocated from the cytoplasm to the nucleus and formed subnuclear fine foci. Coexpression of human Runx2 disrupted the AR subnuclear fine foci formation, and the intranuclear fluorescent pattern of AR became similar to that of Runx2. On the other hand, ligand-bound ARs repressed the Runx2-mediated transactivation function. Runx2 was also extracted from its original compartment by ligand-bound ARs. These results suggest that both Runx2 and ARs repress the transactivation function of the other protein by extracting it from its original compartment. The AR and Runx2 may play a mutual role in transcriptional activation in osteoblasts.

Selective Tropism of Liver Stem Cells to Hepatocellular Carcinoma in Vivo

World Journal of Gastroenterology : WJG. Jul, 2007  |  Pubmed ID: 17657848

To investigate the selective tropism of liver stem cells to hepatocellular carcinoma (HCC) in an animal model and its feasibility as a vector to deliver therapeutic genes for targeted therapy of HCC.

Study of Myocardial Fiber Pathway Using Magnetic Resonance Diffusion Tensor Imaging

Magnetic Resonance Imaging. Sep, 2007  |  Pubmed ID: 17707167

The purpose of this study was to investigate myocardial fiber pathway distribution in order to provide supplemental information on myocardial fiber architecture and cardiac mechanics. Diffusion tensor imaging (DTI) with medium diffusion resolution (15 directions) was performed on normal canine heart samples (N=6) fixed in formalin. With the use of diffusion tensor fiber tracking, left ventricle (LV) myocardial fiber pathways and helix angles were computed pixel by pixel at short-axis slices from base to apex. Distribution of DTI-tracked fiber pathway length and number was analyzed quantitatively as a function of fiber helix angle in step of 9 degrees . The long fiber pathways were found to have small helix angles. They are mostly distributed in the middle myocardium and run circumferentially. Fiber pathways tracked at the middle and upper LV are generally longer than those near the apex. Majority of fiber pathways have small helix angles between -20 degrees and 20 degrees , dominating the fiber architecture in myocardium. Likely, such myocardial fiber pathway measurement by DTI may reflect the spatial connectiveness or connectivity of elastic myofiber bundles along their preferential pathway of electromechanical activation. The dominance of the long and circumferentially running fiber pathways found in the study may explain the circumferential predominance in left ventricular contraction.

MR Diffusion Tensor Imaging Study of Postinfarct Myocardium Structural Remodeling in a Porcine Model

Magnetic Resonance in Medicine : Official Journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. Oct, 2007  |  Pubmed ID: 17899595

This study aimed to investigate postinfarct left ventricular (LV) fiber structural alterations by ex vivo diffusion tensor imaging (DTI) in a porcine heart model. In vivo cardiac MR imaging was first performed to measure ventricular function in six adult pigs with septal infarction near apex induced by the LAD ligation 13 weeks earlier. Hearts were then excised from the infarct pigs (n = 6) and six intact controls (n = 6) and fixed in formalin. High-resolution DTI was employed to examine changes in fractional anisotropy (FA), apparent diffusion coefficient (ADC), and transmural helix angle distribution in the infarct, adjacent and remote regions as compared to the sham regions in the controls. FA values were found to decrease in the infarct and differ between the adjacent and remote regions. ADC increase in the infarct region was substantial, while changes in the adjacent and remote regions were insignificant. Structurally, the double-helix myocardial structure shifted toward more left-handed around the infarcted myocardium. Accordingly, the histological analysis revealed clear fiber structural degradation in the adjacent region. These findings confirmed the subtle alterations in the myocardial fiber quality and structure not only in the infarcted but also in the surrounding noninfarcted myocardium or borderzone.

Identification and Characterization of the Human Testes-specific Protease 50 Gene Promoter

DNA and Cell Biology. Jun, 2008  |  Pubmed ID: 18462069

Testes-specific protease 50 (TSP50) has been identified as one of the testis-specific proteins that is expressed at high levels in approximately 92% of human breast cancer samples, making it an attractive molecular marker and a potential target for diagnosis and therapy. However, little is known about the transcriptional mechanisms controlling TSP50 gene expression. In the present study, we have characterized the 5' regulatory region of the TSP50 gene in order to understand the molecular mechanisms regulating its expression. Analysis with a series of deletions demonstrated that a 624-bp region was essential for the basal promoter activity of the TSP50 gene. Further analysis results indicated that the two fragment regions +231 to +251 and -22 to -8, especially the putative Sp1 binding site (+237 to +239) and the putative CCAAT/enhancer binding protein (C/EBP) binding site (-15 to -13), are more important for the basal transcription activity of the human TSP50 promoter. Overexpression of Sp1 and C/EBPbeta transcriptional factors upregulated the activities of the TSP50 promoter. Taken together, these results will help to better understand the role of the TSP50 gene in signal-dependent transcriptional regulation, and to develop new reagents for therapeutic downregulation of the TSP50 gene in human breast cancer.

Cantharidin Reverses Multidrug Resistance of Human Hepatoma HepG2/ADM Cells Via Down-regulation of P-glycoprotein Expression

Cancer Letters. Dec, 2008  |  Pubmed ID: 18703276

Multidrug resistance (MDR) is a serious obstacle encountered in cancer treatment. In this study, we established an in vitro multiple drug resistant HepG2 cell line (HepG2/ADM), and characterized its MDR. This model was used to screen potential candidate chemosensitisers from over 200 purified naturally occurring compounds extracted from plants and animals. Cantharidin was found to have a significant reversal on MDR in our model. Further, our results showed that Cantharidin could significantly inhibit P-gp (P-glycoprotein) expression, mRNA transcription, as well as MDR1 promoter activity. These results suggest that Cantharidin is a novel and potent MDR reversal agent and may be a potential adjunctive agent for tumor chemotherapy.

Measurement of Common Carotid Artery Lumen Dynamics During the Cardiac Cycle Using Magnetic Resonance TrueFISP Cine Imaging

Journal of Magnetic Resonance Imaging : JMRI. Dec, 2008  |  Pubmed ID: 19025960

To demonstrate magnetic resonance (MR) measurements of vascular lumen dynamics in common carotid arteries by using true fast imaging with steady-state precession (TrueFISP) cine imaging with an aim to provide additional physiologic information on the vessels.

Requirement of Hydrogen Peroxide and Sp1 in the Stimulation of Na,K-ATPase by Low Potassium in MDCK Epithelial Cells

The International Journal of Biochemistry & Cell Biology. 2008  |  Pubmed ID: 18155951

We have previously implicated reactive oxygen species oxygen (ROS) as a critical signal transducer in the upregulation of Na,K-ATPase by low K+ in MDCK cells, but how ROS mediate this process has not been well defined. We reported here that both of hydrogen peroxide (H2O2) and superoxide anion (O2*(-)) were rapidly produced at the early stage of low K+-treated MDCK cells. Further analysis revealed that NADP/NADPH oxidase-derived H2O2 was specifically involved in low K+-induced Na,K-ATPase alpha1 gene transcription as well as alpha1 and beta1 subunits expressions. Exogenous H2O2 even mimicked the stimulatory effect of low K+ on Na,K-ATPase alpha1 gene transcription. Low K+ triggered a H2O2-dependent ERK1/2 phosphorylation in MDCK cells, nonetheless, this ERK1/2 activation did not finally lead to the upregulation of Na,K-ATPase. Similar to previous findings that Na,K-ATPase beta1 gene transcription was mediated by Sp1, Na,K-ATPase alpha1 gene transcription in low K+-treated MDCK cells was also closely relevant to Sp1 participation, as confirmed by siRNA as well as PCR mutagenesis technologies. Furthermore, Sp1 activation was dependent on H2O2 generation triggered by low K+. Taken together, the data described in this study outlines an essential role of H2O2 and Sp1 in mediating the upregulation of Na,K-ATPase in MDCK cells by low external K+.

[Osteonecrosis of the Jaw Associated with the Use of Bisphosphonates in Multiple Myeloma: Report of Four Cases and Literature Review]

Zhonghua Yi Xue Za Zhi. Nov, 2008  |  Pubmed ID: 19080077

To summarize the clinical features of osteonecrosis of the jaw (ONJ) in multiple myeloma (MM) patients treated with bisphosphonate.

MR Study of the Effect of Infarct Size and Location on Left Ventricular Functional and Microstructural Alterations in Porcine Models

Journal of Magnetic Resonance Imaging : JMRI. Feb, 2009  |  Pubmed ID: 19161181

To investigate the effect of infarct size and location on left ventricular (LV) functional and microstructural alterations in well-established porcine models.

Genetic Variation in ANGPTL4 Provides Insights into Protein Processing and Function

The Journal of Biological Chemistry. May, 2009  |  Pubmed ID: 19270337

Angiopoietin-like protein 4 (ANGPTL4) is a secreted protein that modulates the disposition of circulating triglycerides (TG) by inhibiting lipoprotein lipase (LPL). Here we examine the steps involved in the synthesis and post-translational processing of ANGPTL4, and the effects of a naturally occurring sequence variant (E40K) that is associated with lower plasma TG levels in humans. Expression of the wild-type and mutant proteins in HEK-293A cells indicated that ANGPTL4 formed dimers and tetramers in cells prior to secretion and cleavage of the protein. After cleavage at a canonical proprotein convertase cleavage site ((161)RRKR(164)), the oligomeric structure of the N-terminal domain was retained whereas the C-terminal fibrinogen-like domain dissociated into monomers. Inhibition of cleavage did not interfere with oligomerization of ANGPTL4 or with its ability to inhibit LPL, whereas mutations that prevented oligomerization severely compromised the capacity of the protein to inhibit LPL. ANGPTL4 containing the E40K substitution was synthesized and processed normally, but no monomers or oligomers of the N-terminal fragments accumulated in the medium; medium from these cells failed to inhibit LPL activity. Parallel experiments performed in mice recapitulated these results. Our findings indicate that oligomerization, but not cleavage, of ANGPTL4 is required for LPL inhibition, and that the E40K substitution destabilizes the protein after secretion, preventing the extracellular accumulation of oligomers and abolishing the ability of the protein to inhibit LPL activity.

Identification and Characterization of Human ARIP2 and Its Relation to Breast Cancer

Cytokine. May, 2009  |  Pubmed ID: 19349195

Activin, a member of the TGF-beta superfamily, inhibits the proliferation of breast cancer cells. Activin interacts with its type I and type II receptors to induce phosphorylation of intracellular signaling molecules known as Smads. Previous studies showed that mouse ARIP2 can reduce activin signaling by interacting with activin type II receptors (ActRIIs); however, the activity of ARIP2 in breast cancer is still unclear. In this study, we used RT-PCR to obtain a human homologue of mouse ARIP2, human activin receptor-interacting protein 2 (hARIP2). Like murine ARIP2, hARIP2 has a PDZ domain in its NH2-terminal region and can interact specifically with ActRIIs. Overexpression of hARIP2 reduced activin-induced transcriptional activity and enhanced cell proliferation and colony formation in human breast adenocarcinoma MCF-7 cells and MDA-MB-231 cells. However, down-regulation of hARIP2 expression by RNAi enhanced activin-induced transcriptional activity and reduced cell proliferation and colony formation. Immunohistochemistry revealed that hARIP2 was expressed more frequently and much more intensely in malignant breast tissues such as simple carcinoma, invasive ductal carcinoma and mucinous adenocarcinoma than in benign hyperplasia or fibroadenoma cases. These results suggest that hARIP2 is a putative growth-promoting factor involved in breast tumorigenesis and tumor development.

Role of the Immune Modulator Programmed Cell Death-1 During Development and Apoptosis of Mouse Retinal Ganglion Cells

Investigative Ophthalmology & Visual Science. Oct, 2009  |  Pubmed ID: 19420345

Mammalian programmed cell death (PD)-1 is a membrane-associated receptor regulating the balance between T-cell activation, tolerance, and immunopathology; however, its role in neurons has not yet been defined. The hypothesis that PD-1 signaling actively promotes retinal ganglion cell (RGC) death within the developing mouse retina was investigated.

Nuclear Localization of C-FLIP-L and Its Regulation of AP-1 Activity

The International Journal of Biochemistry & Cell Biology. Aug-Sep, 2009  |  Pubmed ID: 19433309

Cellular FLICE-like inhibitory protein (c-FLIP-L), similar in structure to caspase-8, is capable of blocking Fas- or other death receptors (DR)-mediated apoptosis through association with FADD in the DISC. Recent studies have implicated the function of c-FLIP-L in T-cell proliferation, but the exact mechanism underlying this process remains to be elucidated. In this report, we showed for the first time that c-FLIP-L was present in both the cytoplasm and nucleus of cells, but was more abundantly distributed in the nucleus. The putative NLS signal locates within the p12 region of caspase-like domain. Furthermore, c-FLIP's export to cytoplasm membrane was dependent on apoptotic stimulation, while it rapidly translocated to the nucleus in response to proliferative stimuli. To gain insights into the possible function of c-FLIP-L in the nucleus, we found c-FLIP-L could activate the AP-1 transcriptional activity independent of MAPK activation. In sum, our findings describe a novel function of c-FLIP-L involved in AP-1 activation and cell proliferation.

Plasma Membrane Depolarization and Na,K-ATPase Impairment Induced by Mitochondrial Toxins Augment Leukemia Cell Apoptosis Via a Novel Mitochondrial Amplification Mechanism

Biochemical Pharmacology. Jul, 2009  |  Pubmed ID: 19442964

Na,K-ATPase is a ubiquitous transmembrane protein that regulates and maintains the intracellular Na(+) and K(+) gradient necessary for cell homeostasis. Recently, the importance of this pump in external stimuli-induced leukemia cell apoptosis has been increasingly appreciated, however, the exact role of Na,K-ATPase in mitochondrial apoptotic pathway still remains little understood. In this study, we found mitochondrial toxin rotenone caused a rapid mitochondrial membrane potential (MMP) collapse in Jurkat cells followed by plasma membrane depolarization (PMP). Similar results were also obtained in human U937 cells and non-cancerous mouse primary T cells. Rotenone-induced PMP depolarization occurred before apoptosis and well correlated with Na,K-ATPase impairment. To understand the mechanisms, Jurkat cells with mtDNA depletion and catalase overexpression were used. The results demonstrated that both PMP depolarization and Na,K-ATPase impairment induced by rotenone were regulated by mitochondrial H(2)O(2) and Bcl-2. Finally, Na,K-ATPase suppression by ouabain greatly accelerated and enhanced mitochondrial toxins-induced cells apoptosis in Jurkat, U937 and primary T cells. In sum, by using leukemia cells and mouse primary T cells, we confirmed that mitochondria-to-Na,K-ATPase and PMP depolarization might represent a novel mechanism for mitochondria to amplify death signals in the initiation stage of cells apoptosis induced by mitochondrial toxins.

[Ligation and Resection of the Inferior Vena Cava During Surgical Removal of the Retroperitoneal Tumors Involving the Inferior Vena Cava: Feasibility and Safety Assessment]

Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University. May, 2009  |  Pubmed ID: 19460709

To assess the feasibility and safety of excising or patching the inferior vena cava (IVC) without replacement in patients with primary retroperitoneal tumors (PRPT) involving the IVC.

MR Study of Postnatal Development of Myocardial Structure and Left Ventricular Function

Journal of Magnetic Resonance Imaging : JMRI. Jul, 2009  |  Pubmed ID: 19466715

To investigate postnatal development of left ventricular (LV) cardiac function and myocardium structure.

Anti-angiogenesis and Anti-tumor Effects of AdNT4-anginex

Cancer Letters. Nov, 2009  |  Pubmed ID: 19540664

Anginex is a novel artificial peptide that can inhibit angiogenesis. AdNT4-anginex was constructed by inserting the artificial anginex gene into a recombinant adenoviral vector. We demonstrated that AdNT4-anginex inhibited migration of human endothelial cells, angiogenesis and tumor growth in in vitro and in vivo studies. Tumor growth of human H22 hepatoma in mice was inhibited after AdNT4-anginex treatment for 4 weeks, and a significant decrease in tumor size was observed as compared with the control group. Overall, these studies indicate that AdNT4-anginex is an effective anti-tumor agent, and deserves more attention and research.

[Construction and Expression of Recombinant Adenovirus Containing Secreted Endostatin in Liver Stem Cell As a Vector for Gene Therapy]

Zhonghua Gan Zang Bing Za Zhi = Zhonghua Ganzangbing Zazhi = Chinese Journal of Hepatology. Aug, 2009  |  Pubmed ID: 19719927

Human Gamma Delta T Cells: a Lymphoid Lineage Cell Capable of Professional Phagocytosis

Journal of Immunology (Baltimore, Md. : 1950). Nov, 2009  |  Pubmed ID: 19843947

Professional phagocytosis in mammals is considered to be performed exclusively by myeloid cell types. In this study, we demonstrate, for the first time, that a mammalian lymphocyte subset can operate as a professional phagocyte. By using confocal microscopy, transmission electron microscopy, and functional Ag presentation assays, we find that freshly isolated human peripheral blood gammadelta T cells can phagocytose Escherichia coli and 1 microm synthetic beads via Ab opsonization and CD16 (FcgammaRIII), leading to Ag processing and presentation on MHC class II. In contrast, other CD16(+) lymphocytes, i.e., CD16(+)/CD56(+) NK cells, were not capable of such functions. These findings of distinct myeloid characteristics in gammadelta T cells strongly support the suggestion that gammadelta T cells are evolutionarily ancient lymphocytes and have implications for our understanding of their role in transitional immunity and the control of infectious diseases and cancer.

MR Investigation of the Coupling Between Myocardial Fiber Architecture and Cardiac Contraction

Conference Proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference. 2009  |  Pubmed ID: 19964360

Left ventricular structure has proved to be related with cardiac function; however the relation of myocardial fiber distribution with regional wall motion remains to be elucidated. In this study, both in vivo tagging and ex vivo DTI studies were performed in adult rats. LV circumferential strain, myocardium twist and myocardial fiber architecture were investigated. Results show that myocardial fiber distribution has direct relation with LV myocardium magnitude of circumferential strain and twist angle. Such integrated functional and structural analysis may provide more information for understanding the fundamental cardiac mechanics and assessment of pathological changes.

Rare Loss-of-function Mutations in ANGPTL Family Members Contribute to Plasma Triglyceride Levels in Humans

The Journal of Clinical Investigation. Jan, 2009  |  Pubmed ID: 19075393

The relative activity of lipoprotein lipase (LPL) in different tissues controls the partitioning of lipoprotein-derived fatty acids between sites of fat storage (adipose tissue) and oxidation (heart and skeletal muscle). Here we used a reverse genetic strategy to test the hypothesis that 4 angiopoietin-like proteins (ANGPTL3, -4, -5, and -6) play key roles in triglyceride (TG) metabolism in humans. We re-sequenced the coding regions of the genes encoding these proteins and identified multiple rare nonsynonymous (NS) sequence variations that were associated with low plasma TG levels but not with other metabolic phenotypes. Functional studies revealed that all mutant alleles of ANGPTL3 and ANGPTL4 that were associated with low plasma TG levels interfered either with the synthesis or secretion of the protein or with the ability of the ANGPTL protein to inhibit LPL. A total of 1% of the Dallas Heart Study population and 4% of those participants with a plasma TG in the lowest quartile had a rare loss-of-function mutation in ANGPTL3, ANGPTL4, or ANGPTL5. Thus, ANGPTL3, ANGPTL4, and ANGPTL5, but not ANGPTL6, play nonredundant roles in TG metabolism, and multiple alleles at these loci cumulatively contribute to variability in plasma TG levels in humans.

Identification and Characterization of the Human SLC5A8 Gene Promoter

Cancer Genetics and Cytogenetics. Jan, 2010  |  Pubmed ID: 20082847

The human SLC5A8 gene is a tumor suppressor. Its silencing may contribute to the carcinogenesis and progression of various tumors, which makes this gene an attractive molecular marker and a potential target for diagnosis and therapy. Little is known about transcriptional mechanisms controlling SLC5A8 gene expression. To better understand the molecular mechanisms regulating SLC5A8 expression, we characterized the 5'-regulatory region and a part of exon 1. Luciferase reporter assays of deletion mutants of SLC5A8 promoter demonstrated that a 295-bp region is essential for the basal promoter activity of the SLC5A8 gene. Further analysis indicated that the CCAAT boxes and GC boxes were involved in positive regulation of SLC5A8 promoter. Overexpression of two transcription factors, CCAAT/enhancer binding protein beta (C/EBPbeta) and specific transcription factor 1 (Sp1), upregulated the activities of the human SLC5A8 promoter and protein expression, suggesting that both C/EBPbeta and Sp1 transcription factors might have functions in SLC5A8 transcription. Taken together, our results elucidate the mechanism underlying the regulation of SLC5A8 gene transcription and also define a novel regulatory sequence that may be used to increase expression of the SLC5A8 gene in cancer gene therapy.

Induction of C-Jun Phosphorylation in Spinal Motoneurons in Neonatal and Adult Rats Following Axonal Injury

Brain Research. Mar, 2010  |  Pubmed ID: 20096669

This study aims to address if phosphorylation of the transcription factor c-Jun is associated with lesion-induced death of spinal motoneurons, and if this cellular response is modulated by glial-cell-line-derived neurotrophic factor (GDNF). We found that after both distal axotomy and root avulsion, spinal motoneurons in neonatal rats expressed phosphorylated c-Jun (p-c-Jun) and almost all injured motoneurons in these animals died. Similarly, root avulsion in adult rats also induced p-c-Jun expression that preceded the loss of motoneurons. In contrast, neither motoneuron death nor p-c-Jun induction was found after distal axotomy of spinal nerves in adult rats. Application of GDNF after distal axotomy in the neonatal model prevented motoneuron death but did not alter the expression of p-c-Jun in the surviving motoneurons. We conclude that c-Jun phosphorylation correlates with the cellular events leading to motoneuron death and that its expression cannot be modulated by GDNF. We further showed that expression of p-c-Jun was not correlated with the expression of growth-associated protein-43 (GAP-43), whose expression was closely correlated both temporally and spatially with periods of axonal outgrowth, suggesting that p-c-Jun may not be related with axonal regeneration of injured motoneurons.

C-reactive Protein Promotes Cardiac Fibrosis and Inflammation in Angiotensin II-induced Hypertensive Cardiac Disease

Hypertension. Apr, 2010  |  Pubmed ID: 20157054

C-reactive protein (CRP) is a risk factor or biomarker for cardiovascular diseases, including hypertension. The present study investigated the functional importance of human CRP in hypertensive cardiac remodeling by a chronic infusion of angiotensin II (Ang II) into mice that express human CRP. Compared with the wild-type mice, although Ang II infusion caused an equally high systolic blood pressure, levels of human CRP were further elevated, and cardiac remodeling was markedly exacerbated in mice that express human CRP, resulting in a significant reduction in the left ventricular ejection fraction and fractional shortening and an increase in cardiac fibrosis (collagen I and III and alpha-smooth muscle actin) and inflammation (interleukin 1beta and tumor necrosis factor-alpha). The enhancement in cardiac remodeling in mice that express human CRP was associated with further upregulation of the Ang II type I receptor and transforming growth factor-beta1 and overactivation of both transforming growth factor-beta/Smad and nuclear factor-kappaB signaling pathways. Furthermore, in vitro studies in cardiac fibroblasts revealed that CRP alone was able to significantly induce expression of the Ang II type I receptor, collagen I/III, and alpha-smooth muscle actin, as well as proinflammation cytokines (interleukin 1beta and tumor necrosis factor-alpha), which was further enhanced by addition of Ang II. In conclusion, CRP is not only a biomarker but also a mediator in Ang II-mediated cardiac remodeling. Enhanced upregulation of the Ang II type I receptor and activation of the transforming growth factor-beta/Smad and nuclear factor-kappaB signaling pathways may be the mechanisms by which CRP promotes cardiac fibrosis and inflammation under high Ang II conditions.

Mapping Site-specific Protein N-glycosylations Through Liquid Chromatography/mass Spectrometry and Targeted Tandem Mass Spectrometry

Rapid Communications in Mass Spectrometry : RCM. Apr, 2010  |  Pubmed ID: 20209665

Glycosylation is one of the most common posttranslational modifications (PTMs) of proteins, the characterization of which is commonly achieved through proteomic protocol, involving trypsin digestion followed by liquid chromatography/tandem mass spectrometry (LC/MS/MS). However, it is often not possible to characterize all glycopeptides in a complex sample because of the high complexity of glycoproteomic samples, and the relative lower abundances of glycopeptides in comparison to the unmodified peptides. We present here a targeted MS/MS analysis approach, which utilizes a previously developed computational tool, GlyPID, to guide multiple experiments, thus permitting a complete characterization of all N-glycosylation sites of glycoproteins present in a complex sample. We have tested our approach using model glycoproteins analyzed by high-resolution LTQ-FT MS. The results demonstrate a potential use of our method for a high-throughput characterization of complex mixtures of glycosylated proteins.

Butyrate Induces Cell Apoptosis Through Activation of JNK MAP Kinase Pathway in Human Colon Cancer RKO Cells

Chemico-biological Interactions. May, 2010  |  Pubmed ID: 20346929

Butyrate has been shown to display anti-cancer activity through the induction of apoptosis in various cancer cells. However, the underlying mechanism involved in butyrate-induced apoptosis is still not fully understood. Here, we investigated the cytotoxicity mechanism of butyrate in human colon cancer RKO cells. The results showed that butyrate induced a strong growth inhibitory effect against RKO cells. Butyrate also effectively induced apoptosis in RKO cells, which was characterized by DNA fragmentation, nuclear staining of DAPI, and the activation of caspase-9 and caspase-3. The expression of anti-apoptotic protein Bcl-2 decreased, whereas the apoptotic protein Bax increased in a dose-dependent manner during butyrate-induced apoptosis. Moreover, treatment of RKO cells with butyrate induced a sustained activation of the phosphorylation of c-jun N-terminal kinase (JNK) in a dose- and time-dependent manner, and the pharmacological inhibition of JNK MAPK by SP600125 significantly abolished the butyrate-induced apoptosis in RKO cells. These results suggest that butyrate acts on RKO cells via the JNK but not the p38 pathway. Butyrate triggered the caspase apoptotic pathway, indicated by an enhanced Bax-to-Bcl-2 expression ratio and caspase cascade reaction, which was blocked by SP600125. Taken together, our data indicate that butyrate induces apoptosis through JNK MAPK activation in colon cancer RKO cells.

Rare Hemoglobinopathy Presenting As Progressive Dyspnea

American Journal of Hematology. May, 2010  |  Pubmed ID: 20425798

Basic FGF Downregulates TSP50 Expression Via the ERK/Sp1 Pathway

Journal of Cellular Biochemistry. Sep, 2010  |  Pubmed ID: 20506264

Previous studies demonstrated that the expression of testes-specific protease 50 (TSP50) was increased in breast cancer cells and that overexpression of TSP50 can promote tumorigenesis. Thus, it is important to identify the regulatory mechanisms of TSP50 for tumor therapy. In this study, we elucidated the mechanism underlying TSP50 downregulation by basic fibroblast growth factor (bFGF). We used MDA-MB-231 and HEK293T cell lines to address this issue. RT-PCR and promoter activity assays indicated that bFGF downregulates TSP50 expression via transcriptional activation. We next investigated the signaling pathway that mediated the effect of bFGF on TSP50 transcription, and identified that bFGF induced the phosphorylation of ERK and Sp1. An ERK inhibitor suppressed Sp1 phosphorylation and bFGF-reduced TSP50 expression at the mRNA level. In addition, the dominant negative (DN) mutants of ERK and Sp1 both suppressed the reduction of TSP50 by bFGF. Deletion and mutation analyses indicated that the Sp1 site, located within the +237/+239 region of the human TSP50 promoter, is the major responsive element for bFGF. Taken together, our results strongly suggest that bFGF mediates TSP50 downregulation by ERK activation, leading to the phosphorylation of Sp1 in this process.

NSAID Sulindac and Its Analog Bind RXRalpha and Inhibit RXRalpha-dependent AKT Signaling

Cancer Cell. Jun, 2010  |  Pubmed ID: 20541701

Nonsteroidal anti-inflammatory drugs (NSAIDs) exert their anticancer effects through cyclooxygenase-2 (COX-2)-dependent and independent mechanisms. Here, we report that Sulindac, an NSAID, induces apoptosis by binding to retinoid X receptor-alpha (RXRalpha). We identified an N-terminally truncated RXRalpha (tRXRalpha) in several cancer cell lines and primary tumors, which interacted with the p85alpha subunit of phosphatidylinositol-3-OH kinase (PI3K). Tumor necrosis factor-alpha (TNFalpha) promoted tRXRalpha interaction with the p85alpha, activating PI3K/AKT signaling. When combined with TNFalpha, Sulindac inhibited TNFalpha-induced tRXRalpha/p85alpha interaction, leading to activation of the death receptor-mediated apoptotic pathway. We designed and synthesized a Sulindac analog K-80003, which has increased affinity to RXRalpha but lacks COX inhibitory activity. K-80003 displayed enhanced efficacy in inhibiting tRXRalpha-dependent AKT activation and tRXRalpha tumor growth in animals.

Attenuation of Left Ventricular Adverse Remodeling with Epicardial Patching After Myocardial Infarction

Journal of Cardiac Failure. Jul, 2010  |  Pubmed ID: 20610235

Previous studies suggested that epicardial patch applied to the infarcted site after acute myocardial infarction (MI) can alleviate left ventricular (LV) remodeling and improve cardiac performance; however, the effects of regional epicardial patch on chronic phase of LV remodeling remain unclear.

Effect of Antler Extract on Corticosteroid-induced Avascular Necrosis of the Femoral Head in Rats

Journal of Ethnopharmacology. Jan, 2010  |  Pubmed ID: 19818844

Deer antler, traditionally used as a tonic and valuable drug in oriental medicine, has been considered to possess bone-strengthening activity and effectively used in bone diseases therapy.

Activin A Induces SLC5A8 Expression Through the Smad3 Signaling Pathway in Human Colon Cancer RKO Cells

The International Journal of Biochemistry & Cell Biology. Dec, 2010  |  Pubmed ID: 20732443

SLC5A8 (Solute carrier family 5, member 8), proposed to be a potential tumor suppressor gene, is down-regulated by epigenetic changes in some colorectal cancer cells, and ectopic expression of SLC5A8 in SLC5A8-deficient colon cancer cell lines leads to suppression of the colony-forming ability of these cells. Activin A, a member of the transforming growth factor-β (TGF-β) superfamily, has been shown to inhibit the proliferation of a variety of tumor (and normal) human cell types. However, the mechanism(s) by which activin A exerts its inhibitory effects are not yet understood. In this study, we showed that activin A up-regulated SLC5A8 expression in colorectal cancer RKO cells and human embryonic kidney (HEK) 293T cells. To elucidate the underlying mechanism involved in this process, we investigated the activation of the Smad signaling pathway, and analyzed the effects of dominant negative Smad3 and Smad2 proteins on activin A-induced SLC5A8 expression. The results indicated that activin A-induced SLC5A8 expression was dependent on activation of Smad3. Further analysis showed that activin A induced SLC5A8 expression via transcriptional activation. Deletion analysis indicated that the CAGA elements located within the -273/-222 region of the human SLC5A8 promoter were responsive to activin A. Taken together, our results strongly suggest that activin A up-regulates SLC5A8 expression through the Smad signaling pathway, which also partially explains the inhibitory effects of activin A in RKO cells.

Proarrhythmic Risk of Embryonic Stem Cell-derived Cardiomyocyte Transplantation in Infarcted Myocardium

Heart Rhythm : the Official Journal of the Heart Rhythm Society. Dec, 2010  |  Pubmed ID: 20833268

Cellular replacement strategies using embryonic stem cells (ESCs) and their cardiac derivatives are emerging as novel experimental therapeutic paradigms for the treatment of post-myocardial infarction (MI) left ventricular (LV) dysfunction; however, their potential proarrhythmic risk remains unclear.

O-glycosylation Modulates Proprotein Convertase Activation of Angiopoietin-like Protein 3: Possible Role of Polypeptide GalNAc-transferase-2 in Regulation of Concentrations of Plasma Lipids

The Journal of Biological Chemistry. Nov, 2010  |  Pubmed ID: 20837471

The angiopoietin-like protein 3 (ANGPTL3) is an important inhibitor of the endothelial and lipoprotein lipases and a promising drug target. ANGPTL3 undergoes proprotein convertase processing (RAPR(224)↓TT) for activation, and the processing site contains two potential GalNAc O-glycosylation sites immediately C-terminal (TT(226)). We developed an in vivo model system in CHO ldlD cells that was used to show that O-glycosylation in the processing site blocked processing of ANGPTL3. Genome-wide SNP association studies have identified the polypeptide GalNAc-transferase gene, GALNT2, as a candidate gene for low HDL and high triglyceride blood levels. We hypothesized that the GalNAc-T2 transferase performed critical O-glycosylation of proteins involved in lipid metabolism. Screening of a panel of proteins known to affect lipid metabolism for potential sites glycosylated by GalNAc-T2 led to identification of Thr(226) adjacent to the proprotein convertase processing site in ANGPTL3. We demonstrated that GalNAc-T2 glycosylation of Thr(226) in a peptide with the RAPR(224)↓TT processing site blocks in vitro furin cleavage. The study demonstrates that ANGPTL3 activation is modulated by O-glycosylation and that this step is probably controlled by GalNAc-T2.

Knockdown of TSP50 Inhibits Cell Proliferation and Induces Apoptosis in P19 Cells

IUBMB Life. Nov, 2010  |  Pubmed ID: 21086474

Earlier studies identified testes-specific protease 50 (TSP50), which encodes a threonine protease, and showed that it was abnormally reactivated in many breast cancer biopsies. Further, it was shown to be negatively regulated by the p53 gene. However, little is known about the biological function of TSP50. In this study, we applied RNA interference to knockdown TSP50 gene expression in P19 murine embryonal carcinoma stem cells and tested whether this modulated the cell phenotype. The results showed that downregulation of TSP50 expression not only reduced cell proliferation, colony formation, and migration but also induced cell apoptosis. Further investigation revealed that knockdown of TSP50 resulted in greater sensitivity to doxorubicin-induced apoptosis and that activation of caspase-3 was involved in this process.

Recombinant Proteins Secreted from Tissue-engineered Bioartificial Muscle Improve Cardiac Dysfunction and Suppress Cardiomyocyte Apoptosis in Rats with Heart Failure

Chinese Medical Journal. Dec, 2010  |  Pubmed ID: 22166642

Tissue-engineered bioartificial muscle-based gene therapy represents a promising approach for the treatment of heart diseases. Experimental and clinical studies suggest that systemic administration of insulin-like growth factor-1 (IGF-1) protein or overexpression of IGF-1 in the heart exerts a favorable effect on cardiovascular function. This study aimed to investigate a chronic stage after myocardial infarction (MI) and the potential therapeutic effects of delivering a human IGF-1 gene by tissue-engineered bioartificial muscles (BAMs) following coronary artery ligation in Sprague-Dawley rats.

Social Comparison Affects Brain Responses to Fairness in Asset Division: An ERP Study with the Ultimatum Game

Frontiers in Human Neuroscience. 2011  |  Pubmed ID: 22087088

Previous studies have shown that social comparison influences individual's fairness consideration and other-regarding behavior. However, it is not clear how social comparison affects the brain activity in evaluating fairness during asset distribution. In this study, participants, acting as recipients in the ultimatum game, were informed not only of offers to themselves but also of the average amount of offers in other allocator-recipient dyads. Behavioral results showed that the participants were more likely to reject division schemes when they were offered less than the other recipients, especially when the offers were highly unequal. Event-related brain potentials recorded from the participants showed that highly unequal offers elicited more negative-going medial frontal negativity than moderately unequal offers in an early time window (270-360 ms) and this effect was not significantly modulated by social comparison. In a later time window (450-650 ms), however, the late positive potential (LPP) was more positive for moderately unequal offers than for highly unequal offers when the other recipients were offered less than the participants, whereas this distinction disappeared when the other recipients were offered the same as or more than the participants. These findings suggest that the brain activity in evaluating fairness in asset division entails both an earlier (semi-) automatic process in which the brain responds to fairness at an abstract level and a later appraisal process in which factors related to social comparison and fairness norms come into play.

Novel Biomarker Panel Predicts Prognosis in Human Papillomavirus-negative Oropharyngeal Cancer: An Analysis of the TAX 324 Trial

Cancer. Aug, 2011  |  Pubmed ID: 22009819

BACKGROUND: New treatment strategies for locally advanced head and neck squamous cell carcinoma combine induction chemotherapy and chemoradiation. Identifying the predictors of outcome in sequentially treated patients is critical for focusing therapeutic research. In this analysis, the authors evaluated human papillomavirus type 16 (HPV-16) status and the expression levels of a defined set of biomarkers to identify predictors of response to this treatment modality. METHODS: In total, 114 patients with oropharyngeal cancer (OPC) who were treated on the TAX 324 trial (cisplatin and fluorouracil with or without docetaxel in patients with locally advanced head and neck squamous cell carcinoma) had pretreatment biopsy specimens that were evaluable for HPV-16 DNA and immunohistochemical expression of the following biomarkers: beta-tubulin II (βT-II), glutathione S-transferase (GST-π), p53, and B-cell lymphoma 2 (Bcl-2). Patients were categorized into risk groups based on their HPV status and biomarker expression levels. RESULTS: Patients with high-risk OPC were defined by HPV-negative status and either elevated expression of βT-II or levels of at least 2 of the other 3 adverse markers (elevated GST-π, elevated p53, or low Bcl-2). All other HPV-negative patients were categorized as moderate risk. In total, 55 patients were HPV-positive, and 59 patients were HPV-negative, with 34 were categorized as high risk and 25 categorized as moderate risk. The median survival for HPV-positive patients was not reached. The median survival was 44.2 months for moderate-risk patients (95% confidence interval, 20.9 months to not reached) and 12.1 months for high-risk patients (95% confidence interval, 7.5-19.7 months). The 24-month survival rate was 89% for HPV-positive patients, 67% for moderate-risk patients, and 29% for high-risk patients (P < .0001). CONCLUSIONS: The molecular data set in this study readily differentiated between 2 distinct groups of patients with locally advanced, HPV-negative OPC. This risk-stratification strategy may serve as a guide for treatment selection. Cancer 2011;. © 2011 American Cancer Society.

Regulation of Nur77 Expression by β-catenin and Its Mitogenic Effect in Colon Cancer Cells

FASEB Journal : Official Publication of the Federation of American Societies for Experimental Biology. Jan, 2011  |  Pubmed ID: 20847229

The orphan nuclear receptor Nur77 is an immediate-early response gene whose expression is rapidly induced by various extracellular stimuli. The aims of this study were to study the role of Nur77 expression in the growth and survival of colon cancer cells and the mechanism by which Nur77 expression was regulated. We showed that levels of Nur77 were elevated in a majority of human colon tumors (9/12) compared to their nontumorous tissues and that Nur77 expression could be strongly induced by different colonic carcinogens including deoxycholic acid (DCA). DCA-induced Nur77 expression resulted in up-regulation of antiapoptotic BRE and angiogenic VEGF, and it enhanced the growth, colony formation, and migration of colon cancer cells. In studying the mechanism by which Nur77 was regulated in colon cancer cells, we found that β-catenin was involved in induction of Nur77 expression through its activation of the transcriptional activity of AP-1 (c-Fos/c-Jun) that bound to and transactivated the Nur77 promoter. Together, our results demonstrate that Nur77 acts to promote the growth and survival of colon cancer cells and serves as an important mediator of the Wnt/β-catenin and AP-1 signaling pathways.

Reversal Effect of Dioscin on Multidrug Resistance in Human Hepatoma HepG2/adriamycin Cells

European Journal of Pharmacology. Mar, 2011  |  Pubmed ID: 21195709

Multidrug resistance is a serious obstacle encountered in cancer treatment. Since drug resistance in human cancer is mainly associated with overexpression of the multidrug resistance gene 1 (MDR1), the promoter of the human MDR1 gene may be a target for multidrug resistance reversion drug screening. In the present study, HEK293T cells were transfected with pGL3 reporter plasmids containing the 2kb of MDR1 promoter, and the transfected cells were used as models to screen for candidate multidrug resistance inhibitors from over 300 purified naturally occurring compounds extracted from plants and animals. Dioscin was found to have an inhibiting effect on MDR1 promoter activity. The resistant HepG2 cell line (HepG2/adriamycin) was used to validate the activity of multidrug resistance reversal by Dioscin. Results showed that Dioscin could decrease the resistance degree of HepG2/adriamycin cells, and significantly inhibit P-glycoprotein expression, as well as increase the accumulation of adriamycin in HepG2/adriamycin cells as measured by Flow Cytometric analysis. These results suggest that Dioscin is a potent multidrug resistance reversal agent and may be a potential adjunctive agent for tumor chemotherapy.

Assembly of Folate-polyoxometalate Hybrid Spheres for Colorimetric Immunoassay Like Oxidase

Chemical Communications (Cambridge, England). Mar, 2011  |  Pubmed ID: 21258749

Folate-functionalized polyoxometalate nanoparticles have unique oxidase-like activity, which can facilitate the fast oxidation of organic dyes without using any oxidizing agents or peroxidases especially at neutral pH conditions. This nanoparticle could be used as an agent in colorimetric multiplexed immunoassays.

Dimensions of Problem Gambling Behavior Associated with Purchasing Sports Lottery

Journal of Gambling Studies / Co-sponsored by the National Council on Problem Gambling and Institute for the Study of Gambling and Commercial Gaming. Mar, 2011  |  Pubmed ID: 21365440

The purpose of this study was to identify and examine the dimensions of problem gambling behaviors associated with purchasing sports lottery in China. This was accomplished through the development and validation of the Scale of Assessing Problem Gambling (SAPG). The SAPG was initially developed through a comprehensive qualitative research process. Research participants (N = 4,982) were Chinese residents who had purchased sports lottery tickets, who responded to a survey packet, representing a response rate of 91.4%. Data were split into two halves, one for conducting an EFA and the other for a CFA. A five-factor model with 19 items (Social Consequence, Financial Consequence, Harmful Behavior, Compulsive Disorder, and Depression Sign) showed good measurement properties to assess problem gambling of sports lottery consumers in China, including good fit to the data (RMSEA = 0.050, TLI = 0.978, and CFI = 0.922), convergent and discriminate validity, and reliability. Regression analyses revealed that except for Depression Sign, the SAPG factors were significantly (P < 0.05) predictive of purchase behaviors of sports lottery. This study represents an initial effort to understand the dimensions of problem gambling associated with Chinese sports lottery. The developed scale may be adopted by researchers and practitioners to examine problem gambling behaviors and develop effective prevention and intervention procedures based on tangible evidence.

Alantolactone Inhibits Cell Proliferation by Interrupting the Interaction Between Cripto-1 and Activin Receptor Type II A in Activin Signaling Pathway

Journal of Biomolecular Screening. Jun, 2011  |  Pubmed ID: 21378277

It has been suggested that deregulation of activin signaling contributes to tumor formation. Activin signaling is blocked in cancer cells due to the complex formed by Cripto-1, activin, and activin receptor type II (ActRII). In this study, the authors used a mammalian two-hybrid system to construct a drug screening model to obtain a small molecular inhibitor capable of interrupting the interaction between Cripto-1 and ActRII. They screened 300 natural components and identified alantolactone. Data suggested that alantolactone induced activin/SMAD3 signaling in human colon adenocarcinoma HCT-8 cells. The authors also found that alantolactone exhibited antiproliferative function specific to tumor cells, with almost no toxicity to normal cells at a concentration of 5 µg/mL. Furthermore, they proved that the antiproliferative function of alantolactone was activin/SMAD3 dependent. These results suggest that alantolactone performs its antitumor effect by interrupting the interaction between Cripto-1 and the activin receptor type IIA in the activin signaling pathway. Moreover, screening for inhibitors of Cripto-1/ActRII is a potentially beneficial approach to aid in discovering novel cancer treatment.

Functional Characterization of the Recombinant Antimicrobial Peptide Trx-Ace-AMP1 and Its Application on the Control of Tomato Early Blight Disease

Applied Microbiology and Biotechnology. May, 2011  |  Pubmed ID: 21380518

Ace-AMP1 is a potent antifungal peptide found in onion (Allium cepa) seeds with sequence similarity to plant lipid transfer proteins. Transgenic plants over-expressing Ace-AMP1 gene have enhanced disease resistance to some fungal pathogens. However, mass production in heterologous systems and in vitro application of this peptide have not been reported. In this study, Ace-AMP1 was highly expressed in a prokaryotic Escherichia coli system as a fusion protein. The purified protein inhibited the growth of many plant fungal pathogens, especially Alternaria solani, Fusarium oxysporum f. sp. vasinfectum, and Verticillium dahliae. The inhibitory effect was accompanied by hyphal hyperbranching for V. dahliae but not for F. oxysporum f. sp. vasinfectum and A. solani, suggesting that the mode of action of Ace-AMP1 on different fungi might be different. Application of Ace-AMP1 on tomato leaves showed that the recombinant protein conferred strong resistance to the tomato pathogen A. solani and could be used as an effective fungicide.

Testes-specific Protease 50 (TSP50) Promotes Cell Proliferation Through the Activation of the Nuclear Factor κB (NF-κB) Signalling Pathway

The Biochemical Journal. Jun, 2011  |  Pubmed ID: 21385156

TSP50 (testes-specific protease 50) is a testis-specific expression protein, which is expressed abnormally at high levels in breast cancer tissues. This makes it an attractive molecular marker and a potential target for diagnosis and therapy; however, the biological function of TSP50 is still unclear. In the present study, we show that overexpression of TSP50 in CHO (Chinese-hamster ovary) cells markedly increased cell proliferation and colony formation. Mechanistic studies have revealed that TSP50 can enhance the level of TNFα (tumour necrosis factor α)- and PMA-induced NF-κB (nuclear factor κB)-responsive reporter activity, IκB (inhibitor of NF-κB) α degradation and p65 nuclear translocation. In addition, the knockdown of endogenous TSP50 in MDA-MB-231 cells greatly inhibited NF-κB activity. Co-immunoprecipitation studies demonstrated an interaction of TSP50 with the NF-κB-IκBα complex, but not with the IKK (IκB kinase) α/β-IKKγ complex, which suggested that TSP50, as a novel type of protease, promoted the degradation of IκBα proteins by binding to the NF-κB-IκBα complex. Our results also revealed that TSP50 can enhance the expression of NF-κB target genes involved in cell proliferation. Furthermore, overexpression of a dominant-negative IκB mutant that is resistant to proteasome-mediated degradation significantly reversed TSP50-induced cell proliferation, colony formation and tumour formation in nude mice. Taken together, the results of the present study suggest that TSP50 promotes cell proliferation, at least partially, through activation of the NF-κB signalling pathway.

The Endothelial Dysfunction in Patients with Type 2 Diabetes Mellitus is Associated with IL-6 Gene Promoter Polymorphism in Chinese Population

Endocrine. Aug, 2011  |  Pubmed ID: 21424184

The purpose of this study is to examine the effects of IL-6 gene promoter -174G/C and -572G/C polymorphism on endothelial function of Chinese T2DM and normal glucose regulation (NGR) subjects. 512 newly diagnosed T2DM patients and 483 NGR subjects were recruited and Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) was performed for the IL-6 gene promoter -174G/C and -572G/C polymorphism. Flow-mediated dilation (FMD) was measured as a non-invasive indicator for endothelial function. The results show that the C allele and CC genotype at -174 of IL-6 gene promoter region was extremely rare in both T2DM and NGR groups; genotypes' and alleles' frequency at -572 of IL-6 gene promoter region is of no difference between T2DM and NGR groups; within T2DM group, higher plasma IL-6 concentration and lower FMD was found in patients with -572 GC (2.36 ± 0.69, 4.23 ± 3.82%) or GG (2.32 ± 0.74, 4.24 ± 3.67%) genotype, compared with patients with CC (2.15 ± 0.62, 5.28 ± 3.94%) genotype. The conclusion of the study is that in comparison with patients of CC genotype, the T2DM patients of -572 GC or GG genotype may have more aggravated endothelial dysfunction (ED) and be at higher risk for coronary artery disease (CAD).

Nogo-66 Inhibits the Dye-coupling of Astrocytic Gap Junctions in Vitro

Neurochemical Research. Jun, 2011  |  Pubmed ID: 21461775

Communication between astrocytes via the gap junction is crucial for maintaining homeostasis of the extra-neuronal microenvironment of the central nervous system. Dysfunction of astrocytic gap junctions is involved in many brain disorders. Our previous studies demonstrated a novel co-localization of Nogo-66 receptor at glial gap junctions in rat cerebellum and posterior pituitary. The present study was aimed at exploring whether Nogo-66 can modulate glial gap junctions in vitro. We confirmed the co-localization of Nogo-66 receptor with Cx43 in cultured astrocytes, and stimulated astrocytes with myelin extracts, or Nogo-66-Fc conditioned medium. Finally, we expressed and purified a functionally effective GST-Nogo-66 peptide. Lucifer yellow transfer assay was adopted to measure the gap junction permeability. The results showed that the spreading of Lucifer yellow was inhibited significantly by all three treatments as compared with their corresponding controls. Therefore, this study shows a novel inhibitory effect of Nogo-66 on the permeability of astrocytic gap junctions, suggesting a presumable role of Nogo-66 receptor in modulating the glial gap junction.

Reduced Transverse Relaxation Rate (RR2) for Improved Sensitivity in Monitoring Myocardial Iron in Thalassemia

Journal of Magnetic Resonance Imaging : JMRI. Jun, 2011  |  Pubmed ID: 21591022

To evaluate the reduced transverse relaxation rate (RR2), a new relaxation index which has been shown recently to be primarily sensitive to intracellular ferritin iron, as a means of detecting short-term changes in myocardial storage iron produced by iron-chelating therapy in transfusion-dependent thalassemia patients.

Differential Effect of ATP Binding Cassette Transporter A1 R219K and Cholesteryl Ester Transfer Protein TaqIB Genotypes on HDL-C Levels in Overweight/obese and Non-obese Chinese Subjects

Acta Cardiologica. Apr, 2011  |  Pubmed ID: 21591583

ATP-binding cassette transporter A1 (ABCA1) and cholesteryl ester transfer protein (CETP) are involved in the HDL metabolism and play a key role in reverse cholesterol transport. The study aim was mainly to examine the possible association of the ABCA1 and CETP polymorphisms with overweight/obesity in a South-West Chinese population.

Transmural Heterogeneity of Left Ventricular Myocardium Remodeling in Postinfarct Porcine Model Revealed by MR Diffusion Tensor Imaging

Journal of Magnetic Resonance Imaging : JMRI. Jul, 2011  |  Pubmed ID: 21618331

To investigate the transmural heterogeneity of left ventricular myocardium structural remodeling.

Improving Confidence in Detection and Characterization of Protein N-glycosylation Sites and Microheterogeneity

Rapid Communications in Mass Spectrometry : RCM. Jul, 2011  |  Pubmed ID: 21698683

Protein glycosylation is one of the most common post-translational modifications, estimated to occur in over 50% of human proteins. Mass spectrometry (MS)-based approaches involving different fragmentation mechanisms have been frequently used to detect and characterize protein N-linked glycosylations. In addition to the popular Collision-Induced Dissociation (CID), high-energy C-trap dissociation (HCD) fragmentation, which is a feature of a linear ion trap orbitrap hybrid mass spectrometer (LTQ Orbitrap), has been recently used for the fragmentation of tryptic N-linked glycopeptides in glycoprotein analysis. The oxonium ions observed with high mass accuracy in the HCD spectrum of glycopeptides can be combined with characteristic fragmentation patterns in the CID spectrum resulting from consecutive glycosidic bond cleavages, to improve the detection and characterization of N-linked glycopeptides. As a means of automating this process, we describe here GlypID 2.0, a software tool that implements several algorithmic approaches to utilize MS information including accurate precursor mass and spectral patterns from both HCD and CID spectra, thus allowing for an unequivocal and accurate characterization of N-linked glycosylation sites of proteins.

Social Distance Modulates Recipient's Fairness Consideration in the Dictator Game: an ERP Study

Biological Psychology. Dec, 2011  |  Pubmed ID: 21889968

Previous research showed that social distance (e.g., being friends or strangers) influences people's fairness consideration and other-regarding behavior. However, it is not entirely clear how social distance influences the recipient's evaluation of (un)fair behavior. In this study, we let people play a dictator game in which they received (un)fair offers from either friends or strangers while their brain potentials were recorded. Results showed that the medial frontal negativity (MFN), a component associated with the processing of expectancy violation, was more negative-going in response to unfair than to fair offers from friends whereas it did not show differential responses to offers from strangers. The P300 was more positive for fair than for unfair offers irrespective of friends or strangers making the offers. These results suggest that violation of social norms can be detected at an early stage of evaluative processing and that this detection can be modulated by social distance.

Involvement of Na(+), K (+)-ATPase and Its Inhibitors in HuR-mediated Cytokine MRNA Stabilization in Lung Epithelial Cells

Cellular and Molecular Life Sciences : CMLS. Jan, 2011  |  Pubmed ID: 20614158

Increasing evidence demonstrates that Na(+), K(+)-ATPase plays an important role in pulmonary inflammation, but the mechanism remains largely unknown. In this study, we used cardiotonic steroids as Na(+), K(+)-ATPase inhibitors to explore the possible involvement of Na(+), K(+)-ATPase in pulmonary epithelial inflammation. The results demonstrated that mice after ouabain inhalation developed cyclooxygenase-2-dependent acute lung inflammation. The in vitro experiments further confirmed that Na(+), K(+)-ATPase inhibitors significantly stimulated cyclooxygenase-2 expression in lung epithelial cells of human or murine origin, the process of which was participated by multiple cis-elements and trans-acting factors. Most importantly, we first described here that Na(+), K(+)-ATPase inhibitors could evoke a significant Hu antigen R nuclear export in lung epithelial cells, which stabilized cyclooxygenase-2 mRNA by binding with a proximal AU-rich element within its 3'-untranslated region. In conclusion, HuR-mediated mRNA stabilization opens new avenues in understanding the importance of Na(+), K(+)-ATPase, as well as its inhibitors in inflammation.

Optimal Time Point for Neuronal Generation of Transplanted Neural Progenitor Cells in Injured Spinal Cord Following Root Avulsion

Cell Transplantation. 2011  |  Pubmed ID: 20719091

Root avulsion of the brachial plexus results in a progressive and pronounced loss of motoneurons. Cell replacement strategies have therapeutic potential in the treatment of motoneuron degenerative neurological disorders. Here, we transplanted spinal cord-derived neural progenitor cells (NPCs) into the cervical ventral horn of adult rats immediately, 2 weeks, or 6 weeks after root avulsion to determine an optimal time scale for the survival and differentiation of grafted cells. We showed that grafted NPCs survived robustly at all three time points and there was no statistical difference in survival rate. Interestingly, however, transplantation at 2 weeks postavulsion significantly increased the neuronal differentiation of transplanted NPCs compared to transplantation immediately or at 6 weeks postavulsion. Moreover, only NPCs transplanted at 2 weeks postavulsion were able to differentiate into choline acetyltransferase (ChAT)-positive neurons. Specific ELISAs and quantitative reverse transcriptase polymerase chain reaction (RT-PCR) demonstrated that expression levels of BDNF and GDNF were significantly upregulated in the ventral cord at 2 weeks postavulsion compared to immediately or at 6 weeks postavulsion. Our study suggests that the cervical ventral horn at 2 weeks postavulsion both supports neuronal differentiation and induces region-specific neuronal generation possibly because of its higher expression of BDNF and GDNF.

Histone Deacetylase 1 is Required for Carbamazepine-induced CYP3A4 Expression

Journal of Pharmaceutical and Biomedical Analysis. Jan, 2012  |  Pubmed ID: 21996064

Carbamazepine (CBZ) is a commonly prescribed antiepileptic drug. Adverse effects and drug-drug interaction are the two major concerns for its clinic application. CBZ is mainly metabolized by cytochrome P450 (CYP) 3A4, a strong inducer of CYP3A4 as well, which in turn influences the pharmaceutical profiles of the co-administrated drugs. To date, little is known about the mechanisms underlying CBZ-induced CYP3A4 expression. In this study, we explored the possible roles of Pregnane X receptor (PXR) and the histone deacetylase 1 (HDAC1) on the CBZ-induced CYP3A4 expression. The results showed that: (1) Although the expression of PXR was increased in CBZ treated cells, PXR gene silencing surprisingly showed no significant effects on CBZ-induced CYP3A4 expression; (2) CBZ inhibited the binding of HDAC1 to the promoter of CYP3A4. In addition, both dominant negative form and siRNA of HDAC1 could repress the CBZ-induced CYP3A4 expression. These data, for the first time indicate that HDAC1, is required for the CBZ-induced CYP3A4 expression.

Long-term Follow-up of a Prospective Trial of Trimodality Therapy of Weekly Paclitaxel, Radiation, and Androgen Deprivation in High-risk Prostate Cancer with or Without Prior Prostatectomy

International Journal of Radiation Oncology, Biology, Physics. Jan, 2012  |  Pubmed ID: 21036487

Weekly paclitaxel, concurrent radiation, and androgen deprivation (ADT) were evaluated in patients with high-risk prostate cancer (PC) with or without prior prostatectomy (RP).

Plasma Lipid Profiling Across Species for the Identification of Optimal Animal Models of Human Dyslipidemia

Journal of Lipid Research. Jan, 2012  |  Pubmed ID: 22021650

In an attempt to understand the applicability of various animal models to dyslipidemia in humans and to identify improved preclinical models for target discovery and validation for dyslipidemia, we measured comprehensive plasma lipid profiles in 24 models. These included five mouse strains, six other nonprimate species, and four nonhuman primate (NHP) species, and both healthy animals and animals with metabolic disorders. Dyslipidemic humans were assessed by the same measures. Plasma lipoprotein profiles, eight major plasma lipid fractions, and FA compositions within these lipid fractions were compared both qualitatively and quantitatively across the species. Given the importance of statins in decreasing plasma low-density lipoprotein cholesterol for treatment of dyslipidemia in humans, the responses of these measures to simvastatin treatment were also assessed for each species and compared with dyslipidemic humans. NHPs, followed by dog, were the models that demonstrated closest overall match to dyslipidemic humans. For the subset of the dyslipidemic population with high plasma triglyceride levels, the data also pointed to hamster and db/db mouse as representative models for practical use in target validation. Most traditional models, including rabbit, Zucker diabetic fatty rat, and the majority of mouse models, did not demonstrate overall similarity to dyslipidemic humans in this study.

Human γδ T Lymphocytes Are Licensed for Professional Antigen Presentation by Interaction with Opsonized Target Cells

Journal of Immunology (Baltimore, Md. : 1950). Feb, 2012  |  Pubmed ID: 22250090

Activated human blood γδ T cells have also been previously demonstrated to behave as professional APCs, although the processes that control APC function have not been characterized. n this study, we show that the acquisition of potent APC function by human blood γδ T cells is achieved after physical interaction with an Ab-coated target cell, a process that we refer to as licensing. In cancer models, licensing of γδ T cells by tumor-reactive mAbs promotes the uptake of tumor Ags and professional presentation to tumor-reactive αβ T cells. We propose that licensing by Ab is a mechanism whereby the adaptive properties of γδ T cells are induced by their innate functions in a spatially and temporally controlled manner.

Ro52/SSA Sensitizes Cells to Death Receptor-induced Apoptosis by Down-regulating C-FLIP(L)

Cell Biology International. Jan, 2012  |  Pubmed ID: 22288650

Ro52/SSA is an autoantigen which presents in patients with Sjogren's syndrome (SS) and systemic lupus erythematosus (SLE). Ro52/SSA was reported to increase cell death and redistributed itself to apoptotic blebs, but its proapoptotic function has not been completely identified. In the present study, we found that overexpression of Ro52/SSA promoted cell apoptosis induced by death receptor in caspase-8-dependent manner. Ro52/SSA expression down-regulated the expression of c-FLIP(L), and Ro52/SSA siRNAs increased c-FLIP(L) production, indicating that Ro52/SSA plays a role in c-FLIP(L) regulation. Furthermore, using reporter assays, we found Ro52/SSA negatively regulated c-FLIP(L) transcriptional level dependent on NF-κB signaling. Taken together, our results suggest that Ro52/SSA is involved in death receptor mediated apoptosis by regulating c-FLIP(L).