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Find video protocols related to scientific articles indexed in Pubmed.
Carbon Nanoparticles based Ratiometric Fluorescent Sensor for Detecting Mercury Ions in Aqueous Media and Living Cells.
ACS Appl Mater Interfaces
PUBLISHED: 11-14-2014
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A novel nanohybrid ratiometric fluorescence sensor is developed for selective detection of mercuric ions (Hg2+) and the application has been successfully demonstrated in HEPES buffer solution, lake water and living cells. The sensor is comprised of water soluble fluorescent carbon nanoparticles (CNPs) and Rhodamine B (RhB) and exhibits their corresponding dual emissions peaked at 437 and 575 nm, respectively, under a single excitation wavelength (350 nm). The photoluminescence of the CNPs in the nanohybrid system can be completely quenched by Hg2+ through effective electron or energy transfer process due to synergetic strong electrostatic interaction and metal-ligand coordination between the surface functional group of CNPs and Hg2+, while that of the RhB remains constant. This results in an obviously distinguishable fluorescence color variation (from violet to orange) of the nanohybrid solution. This novel sensor can effectively identify Hg2+ from other metal ions with relatively low background interference even in a complex system such as lake water. The detection limit of this method is as low as 42 nM. Furthermore, the sensing technique is applicable to detect Hg2+ in living cells.
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Alignment and structural control of nitrogen-doped carbon nanotubes by utilizing precursor concentration effect.
Nanotechnology
PUBLISHED: 11-05-2014
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Nitrogen-doped carbon nanotubes (NCNTs) were prepared using a simple ultrasonic spray pyrolysis method. The precursor concentration effect was examined to effectively control alignment, open tip and diameter of the NCNTs by changing xylene/cyclohexylamine ratio. The structure and morphology of the resultant NCNTs were characterized by scanning electron microscopy, transmission electron microscopy and x-ray photoelectron spectroscopy. The degree of alignment and the diameter of the NCNTs increased as the xylene/cyclohexylamine precursor mixture was changed from 0 to 35% cyclohexylamine. This precursor composition also caused a large number of open-ended nanotubes to form with graphite layers inside the cavities of the NCNTs. However, further increase cyclohexylamine content in the precursor reduced the degree of alignment and diameter of the NCNTs. We demonstrate control over the NCNT alignment and diameter, along with the formation of open-ended nanotube tips, and propose a growth mechanism to understand how these properties are interlinked.
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Effects and mechanism of "jianpi qinghua decoction" on renal fibrosis in rats with glomerulosclerosis.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao
PUBLISHED: 11-01-2014
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Objective To investigate the mechanism of "Jianpi Qinghua Decoction"(JQD)on renal fibrosis by observing the impact of JQD on serum total cholesterol(TC),triglyceride(TG),low-density lipoprotein(LDL),very-low-density lipoprotein(VLDL),and kidney tumor necrosis factor-?(TNF-?)expressions in focal segmental glomerulosclerosis rats induced by nephrectomy combined with adriamycin. Methods Totally 56 male SD rats were divided into normal group,sham operation group,model group,JQD group,Yiqi Jianpi group,Qingre Huashi group,and Niaoduqing group(all n=8). The model of focal segmental glomerulosclerosis was established by the unilateral nephrectomy and the injection of adriamycin in caudal vein of rat at a dose of 3 mg/kg in the latter 5 groups. JQD,the disassembled prescription of Jianpi Qinghua Decoction (Yiqi Jianpi Decoction and Qingre Huashi Decoction),and Niaoduqing Capsule were administered separately for 8 weeks. The serum TC,TG,LDL,and VLDL levels and the expression of Kidney TNF-? were determined. Results Compared with normal group and sham operation group,the serum TC,TG,LDL,and VLDL levels and the kidney TNF-? expression in the model group were significantly higher(all P<0.01). Compared with the model group,the JQD group,Qingre Huashi group,and Niaoduqing group had significantly lower serum TC,TG,LDL,and VLDL levels and kidney TNF-? expression(all P<0.01). Compared with the model group,the Yiqi Jianpi group had significantly lower serum TC,TG,and VLDL levels(all P<0.01),while the serum LDL level and kidney TNF-? expression remained unchanged(all P>0.05). Conclusions JQD can regulate serum lipids and lower the TNF-? expression in kidney tissue and thus improve the renal inflammation and relieve renal fibrosis. The heat-clearing and dampness-removing herbs in the prescription play a central role in fighting against renal fibrosis.
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Efficacy and Safety of Semicircular Canal Occlusion for Intractable Horizontal Semicircular Benign Paroxysmal Positional Vertigo.
Ann. Otol. Rhinol. Laryngol.
PUBLISHED: 11-01-2014
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Some studies have suggested that semicircular canal occlusion is effective and safe for treating intractable posterior semicircular benign paroxysmal positional vertigo (PSC-BPPV), and adverse effects of canal occlusions for intractable horizontal semicircular BPPV (HSC-BPPV) were rarely reported. The aim of this study was to retrospectively discuss the efficacy of semicircular canal occlusion for intractable HSC-BPPV with at least 2 years of follow-up.
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[Effects of se-riched soybean peptide on antioxidant function in rats of fatty liver caused by high-fat diet].
Zhongguo Ying Yong Sheng Li Xue Za Zhi
PUBLISHED: 10-22-2014
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To explore the effect of Se-riched soybean peptide(SSP) on antioxidant function in rats of fatty liver caused by high-fat diet.
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[Expressions of E-cadherin and N-cadherin in prostate cancer and their implications].
Zhonghua Nan Ke Xue
PUBLISHED: 10-14-2014
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To investigate the differences in the expressions of E-cadherin and N-cadherin between high-risk prostate cancer and low- and medium-risk prostate cancer, and analyze their correlation with the age, serum PSA level, and Gleason score of the patients.
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A review of the global burden, novel diagnostics, therapeutics, and vaccine targets for cryptosporidium.
Lancet Infect Dis
PUBLISHED: 10-04-2014
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Cryptosporidium spp are well recognised as causes of diarrhoeal disease during waterborne epidemics and in immunocompromised hosts. Studies have also drawn attention to an underestimated global burden and suggest major gaps in optimum diagnosis, treatment, and immunisation. Cryptosporidiosis is increasingly identified as an important cause of morbidity and mortality worldwide. Studies in low-resource settings and high-income countries have confirmed the importance of cryptosporidium as a cause of diarrhoea and childhood malnutrition. Diagnostic tests for cryptosporidium infection are suboptimum, necessitating specialised tests that are often insensitive. Antigen-detection and PCR improve sensitivity, and multiplexed antigen detection and molecular assays are underused. Therapy has some effect in healthy hosts and no proven efficacy in patients with AIDS. Use of cryptosporidium genomes has helped to identify promising therapeutic targets, and drugs are in development, but methods to assess the efficacy in vitro and in animals are not well standardised. Partial immunity after exposure suggests the potential for successful vaccines, and several are in development; however, surrogates of protection are not well defined. Improved methods for propagation and genetic manipulation of the organism would be significant advances.
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[Study on safety of Tibetan medicine zuotai and preliminary study on clinical safety of its compound dangzuo].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 10-04-2014
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Zuotai (gTso thal) is a typical representative of Tibetan medicines containing heavy metals, but there is still lack of modem safety evaluation data so far. In this study, acute toxicity test, sub-acute toxicity test, one-time administration mercury distribution experiment, long-term mercury accumulative toxicity experiment and preliminary study on clinical safety of Compound Dangzuo were conducted in the hope of obtain the medicinal safety data of Zuotai. In the acute toxicity test, half of KM mice given the lethal dose of Zuotai were not died or poisoned, and LD50 was not found. The maximum tolerated dose of Zuotai was 80 g x kg(-1). In the subacute toxicity test, Zuotai could reduce ALT, AST, Crea levels in serums under low dose (13.34 mg x kg(-1) x d(-1)) and medium dose (53.36 mg x kg(-1) x d(-1)), with significant difference under low dose, and increase the levels of ALT, AST, MDA, Crea in serums under high dose (2 000 mg x kg(-1) x d(-1)); besides, the levels of BUN and GSH in serums reduced with the increase in dose of Zuotai, indicating a significant dose-effect relationship. In the one-time administration distribution experiment, the content of mercury in rat kidney, liver and lung increased after the one-time administration with Zuotai, with a significant dose-dependent relationship in kidney. In the long-term mercury accumulative toxicity experiment, KM mice were administered with equivalent doses of Zuotai for 4.5 months and then stopped drug administration for 1.5 months. Since the 2.5th month, they showed significant mercury accumulation in kidney, which gradually reduced after drug withdrawal, without significant change in mercury content in liver, spleen and brain and ALT, AST, TBIL, BUN and Crea in serum. At the 4.5th month after drug administration, KM mice showed slight structural changes in kidney, liver and spleen tissues, and gradually recovered to normal after drug withdrawal. Besides, no significant difference in weight gain was found between the Zuotai group and the control group. According to the findings of the clinical safety study of Dangzuo, after subjects administered Dangzuo under clinical dose for one month, their serum biochemical indicators, blood routine indicators and urine routine indicators showed no significant adverse change. This study proved that traditional Tibetan medicine Zuotai was slightly toxic, with a better safety in clinical combined administration and no adverse effects on bodies under the clinical dose and clinical medication cycle. However, long-term high-dose administration of Zuotai may have a certain effect on kidney.
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The ionothermal synthesis, structure, and magnetism-structure relationship of two biphenyl tetracarboxylic acid-based metal-organic frameworks.
Dalton Trans
PUBLISHED: 09-27-2014
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Two new metal-organic frameworks () were ionothermally obtained by the reaction of a biphenyltetracarboxylic sodium (Na4BPTC) ligand and M(OOCCH3)2 (M = Co() and Mn()). Crystal structure analysis reveals that is a Co3Na6 unit-based three dimensional heterometallic MOF, while exhibits a {Mn(COO)n} chain-based three-dimensional framework. Furthermore, the magnetic measurement shows that both of them have anti-ferromagnetic properties. A combination of Density Functional Theory (DFT) and Quantum Monte Carlo (QMC) simulation uncovers that in the coupling parameters between two adjacent Mn(ii) ions are J1 = -2.0 cm(-1) and J2 = -1.6 cm(-1), and the magnetism mainly originates from the propagation of Mn(ii) ions by the super-exchange of carboxylates. Interestingly, the superexchange modes of J1 and J2 are different. Two spin nets of -/+/- dominate in the coupling for J1, while for J2 there are two spin nets of -/+/- and one spin net of +/-/+.
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Long noncoding RNA expression in dermal papilla cells contributes to hairy gene regulation.
Biochem. Biophys. Res. Commun.
PUBLISHED: 09-22-2014
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Dermal papilla (DP) cells may be the source of dermal-derived signaling molecules involved in hair-follicle development and postnatal hair cycling. Early-passage DP cells can induce hair growth in vivo, but, on further culture, this ability is lost. The cellular mechanisms underlying the hair-follicle induction property of early-passage DP cells are unclear. Long noncoding RNAs (lncRNAs) are an important class of genes involved in various biological functions. They are aberrantly expressed and play roles in the regulation of the Wnt signaling pathway, a critical point in maintaining hair-induction activity. LncRNA microarray revealed 1683 upregulated and 1773 downregulated lncRNAs in passage-4 DP cells compare with passage-10 DP cells. To investigate the relation between lncRNAs and coding genes in WNT signaling, we constructed a coding-noncoding gene co-expression network using lncRNAs and coding genes that were differentially expressed between the passage-4 and -10 DP cells. RP11-766N7.3, H19 and HOTAIR are specific lncRNAs that were aberrantly expressed in DP cells and played an important role in regulating Wnt signaling. This study may provide potential targets for discovering the hair-follicle induction mechanism of early-passage DP cells.
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Effect of dialysis dose and membrane flux on hemoglobin cycling in hemodialysis patients.
Hemodial Int
PUBLISHED: 09-13-2014
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Many studies found that hemoglobin (Hb) fluctuation was closely related to the prognosis of the maintenance hemodialysis patients. We investigated the association of factors relating dialysis dose and dialyzer membrane with Hb levels. We undertook a randomized clinical trial in 140 patients undergoing thrice-weekly dialysis and assigned patients randomly to a standard or high dose of dialysis; Hb level was measured every month for 12 months. In the standard-dose group, the mean (±SD) urea reduction ratio was 65.1%?±?7.3%, the single-pool Kt/V was 1.26?±?0.11, and the equilibrated Kt/V was 1.05?±?0.09; in the high-dose group, the values were 73.5%?±?8.7%, 1.68?±?0.15, and 1.47?±?0.11, respectively. The standard deviation (SD) and residual SD (liner regression of Hb) values of Hb were significantly higher in the standard-dose group and low-flux group. The percentage achievement of target Hb in the high-dose dialysis group and high-flux dialyzer group was significantly higher than the standard-dose group and low-flux group, respectively. Patients undergoing hemodialysis thrice weekly appear to have benefit from a higher dialysis dose than that recommended by current KDQQI (Kidney Disease Qutcome Quality Initiative) guidelines or from the use of a high-flux membrane, which is in favor of maintaining stable Hb levels.
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Capsaicin induces high expression of BAFF and aberrantly glycosylated IgA1 of tonsillar mononuclear cells in IgA nephropathy patients.
Hum. Immunol.
PUBLISHED: 08-27-2014
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IgA nephropathy (IgAN) is the most common type of primary glomerulonephritis in the world. Hot pepper is the most favorite vegetable for Chinese in Hunan and Sichuan provinces. It can be assumed that capsaicin, the active ingredient of hot pepper, is a possible risk factor in diet in the pathogenesis of IgAN.
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An upconverted photonic nonvolatile memory.
Nat Commun
PUBLISHED: 08-21-2014
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Conventional flash memory devices are voltage driven and found to be unsafe for confidential data storage. To ensure the security of the stored data, there is a strong demand for developing novel nonvolatile memory technology for data encryption. Here we show a photonic flash memory device, based on upconversion nanocrystals, which is light driven with a particular narrow width of wavelength in addition to voltage bias. With the help of near-infrared light, we successfully manipulate the multilevel data storage of the flash memory device. These upconverted photonic flash memory devices exhibit high ON/OFF ratio, long retention time and excellent rewritable characteristics.
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[Infection status of HBV, HCV and HIV in voluntary blood donors of Chinese Nanjing area during 2010-2013].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 08-19-2014
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This study was purposed to understand the infection of HBV, HCV, HIV among the voluntary blood donors and the epidemic trend in infectious population in Chinese Nanjing area, and to guide the mobilization and recruitment of blood donors. A total of 199777 whole blood samples of voluntary blood donors were tested by ELISA, the nucleic acid technology (NAT) combined detection (HBV-DNA, HCV-RNA, HIV-RNA) was added for detection of the samples with HBsAg,anti-HCV, anti-HIV at least unilateral negative donors from June 10, 2010 to June 9, 2013 years, and these statistic data were analyzed. Every HIV reactive sample(HIV-antibody and/or HIV-RNA) was sent to be confirmed in the Centers for Disease Control and Prevention in Nanjing. The results showed that the voluntary donors' infection rate of HBsAg, anti-HCV, anti-HIV were 0.45%, 0.28%, 0.11% respectively; NAT positive rate was 0.07%, 32 cases were confirmed with anti-HIV positive, in which 30 cases were male (6 cases were repeated blood donors) and 2 cases were female, 3 cases were unconfirmed, in which 2 cases were males and 1 case was female. The statistical analysis demonstrated that the difference of unqualitative rate of HBsAg, anti-HCV, anti-HIV was statistically significant between the first-time and repeated blood donors.It is concluded that the positive rate of anti-HCV and anti-HIV displayed a declining trend year by year in Nanjing voluntary blood donation population from June 10,2010 to June 9, 2013 years. The unqualitative rate of HBsAg and NAT increased with the age increasing, while that of anti-HCV, anti-HIV decreased with age increasing. The unqualitative rate of the repeated blood donors is far lower than that of the first-time blood donors. The ELISA positive rate of anti-HIV testing in females is higher than that in males, but the confirmed positive rate of male is significantly higher than that of female. Therefore the consulting skills before donating should be improved, concerning the link of recruiting donors, focusing on strengthening the first-time donors' consultation, evaluating and developing the fixed voluntary blood donors, and vigorously popularizing NAT technology in blood screening to improve the blood safety effectively.
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A new method for modeling coalescent processes with recombination.
BMC Bioinformatics
PUBLISHED: 08-11-2014
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Recombination plays an important role in the maintenance of genetic diversity in many types of organisms, especially diploid eukaryotes. Recombination can be studied and used to map diseases. However, recombination adds a great deal of complexity to the genetic information. This renders estimation of evolutionary parameters more difficult. After the coalescent process was formulated, models capable of describing recombination using graphs, such as ancestral recombination graphs (ARG) were also developed. There are two typical models based on which to simulate ARG: back-in-time model such as ms and spatial model including Wiuf&Hein's, SMC, SMC', and MaCS.
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Zoledronic acid exerts antitumor effects in NB4 acute promyelocytic leukemia cells by inducing apoptosis and S phase arrest.
Biomed. Pharmacother.
PUBLISHED: 08-01-2014
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The aim of this study was to investigate the antitumor effect of zoledronic acid (ZOL) in the NB4 human acute promyelocytic leukemia (APL) cell line and explore the potential mechanism of action of this compound. NB4 cells were exposed to various concentrations (0-200?M) of ZOL. Cell viability was measured by MTS assay. The extent of cell apoptosis and distribution of cells in the different phases of the cell cycle were analyzed with flow cytometry. The expression of apoptosis- and cell cycle-related proteins was assayed by Western blot. The combined effect of ZOL and arsenic trioxide (ATO) on the proliferation of NB4 cells was also determined. The results of this study indicate that ZOL inhibits cell proliferation in a time- and dose-dependent fashion and also induces apoptosis and S phase arrest in a dose-dependent manner. The Western blot analysis confirmed the induction of apoptosis and S phase arrest, revealing that the pro-apoptosis proteins Bax, Puma and activated caspase-9 were upregulated and the anti-apoptosis proteins Bcl-2 and Bcl-xL were downregulated. ZOL at a concentration of 50?M synergized with 0.5?M ATO on the growth inhibition of NB4 cells. Taken together, our data indicate that ZOL exerts a potent antitumor effect on NB4 cells by inducing apoptosis and cell cycle arrest, and that ZOL can synergize with the traditional chemotherapy drug ATO.
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Photon upconversion in core-shell nanoparticles.
Chem Soc Rev
PUBLISHED: 07-25-2014
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Photon upconversion generally results from a series of successive electronic transitions within complex energy levels of lanthanide ions that are embedded in the lattice of a crystalline solid. In conventional lanthanide-doped upconversion nanoparticles, the dopant ions homogeneously distributed in the host lattice are readily accessible to surface quenchers and lose their excitation energy, giving rise to weak and susceptible emissions. Therefore, present studies on upconversion are mainly focused on core-shell nanoparticles comprising spatially confined dopant ions. By doping upconverting lanthanide ions in the interior of a core-shell nanoparticle, the upconversion emission can be substantially enhanced, and the optical integrity of the nanoparticles can be largely preserved. Optically active shells are also frequently employed to impart multiple functionalities to upconversion nanoparticles. Intriguingly, the core-shell design introduces the possibility of constructing novel upconversion nanoparticles by exploiting the energy exchange interactions across the core-shell interface. In this tutorial review, we highlight recent advances in the development of upconversion core-shell nanoparticles, with particular emphasis on the emerging strategies for regulating the interplay of dopant interactions through core-shell nanostructural engineering that leads to unprecedented upconversion properties. The improved control over photon energy conversion will open up new opportunities for biological and energy applications.
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Expression of FK506-binding protein 52 (FKBP52) in chorionic villi with early recurrent spontaneous abortion.
J. Matern. Fetal. Neonatal. Med.
PUBLISHED: 07-24-2014
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Abstract Objective: To investigate the mRNA and protein expression of FK506-binding protein 52 (FKBP52) in the chorionic villi of patients with recurrent spontaneous abortion (RSA) and normal women during early pregnancy. Methods: Fresh chorionic villus tissues were collected from 60 subjects. A total of 30 patients with a history of RSA were enrolled into the RSA group and 30 normal pregnant women were enrolled into the control group. The FKBP52 mRNA expression levels in chorionic villi of the RSA patients and healthy controls were measured via semiquantitative RT-PCR. The protein distribution and expression levels of FKBP52 in chorionic villi were analyzed through immunohistochemistry (IHC). The correlation between FKBP52 expression and RSA was analyzed. Results: We demonstrated that FKBP52 mRNA is expressed in chorionic villi samples of normal pregnancy and RSA. RSA patients exhibited significantly lower FKBP52 gene expression levels compared with those in normal pregnancies (p?
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Prolyl hydroxylation by EglN2 destabilizes FOXO3a by blocking its interaction with the USP9x deubiquitinase.
Genes Dev.
PUBLISHED: 07-04-2014
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The three EglN prolyl hydroxylases (EglN1, EglN2, and EglN3) regulate the stability of the HIF transcription factor. We recently showed that loss of EglN2, however, also leads to down-regulation of Cyclin D1 and decreased cell proliferation in a HIF-independent manner. Here we report that EglN2 can hydroxylate FOXO3a on two specific prolyl residues in vitro and in vivo. Hydroxylation of these sites prevents the binding of USP9x deubiquitinase, thereby promoting the proteasomal degradation of FOXO3a. FOXO transcription factors can repress Cyclin D1 transcription. Failure to hydroxylate FOXO3a promotes its accumulation in cells, which in turn suppresses Cyclin D1 expression. These findings provide new insights into post-transcriptional control of FOXO3a and provide a new avenue for pharmacologically altering Cyclin D1 activity.
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Increased chromogranin A and neuron-specific enolase in rats with chronic nonbacterial prostatitis induced by 17-beta estradiol combined with castration.
Int J Clin Exp Pathol
PUBLISHED: 06-15-2014
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Although chronic nonbacterial prostatitis (CNBP) is a common diagnosis in middle-aged men, the etiology of this disease remains poorly understood. Neuroendocrine cells play an important role in the neuroendocrine regulation of the prostate, and chromogranin A (CgA) and neuron-specific enolase (NSE) are regarded as classic markers of neuroendocrine cells. This study aimed to determine CgA and NSE levels in a CNBP rat model to evaluate the role of neuroendocrine cells in the pathogenesis of CNBP. For developing a CNBP rat model, we examined the ability of 17-beta estradiol and surgical castration alone or in combination to induce CNBP. Histologic inflammation of the prostate was assessed in CNBP-induced rats by hematoxylin-eosin staining, whereas CgA and NSE protein levels were assessed by immunohistochemistry, Western blot analysis, and enzyme-linked immunosorbent assays. Our results showed that 17-beta estradiol combined with castration successfully induced CNBP and that CgA and NSE levels were increased in the prostate of CNBP rats as compared to those without CNBP. These findings indicate that the neuroendocrine regulation mediated by neuroendocrine cells may be involved in the pathogenesis of CNBP.
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Solvent-Free Syntheses of Hierarchically Porous Aluminophosphate-Based Zeolites with AEL and AFI Structures.
Chemistry
PUBLISHED: 06-10-2014
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Development of sustainable routes for synthesizing aluminophosphate-based zeolites are very important because of their wide applications. As a typical sustainable route, solvent-free synthesis of zeolites not only decreases polluted wastes but also increases product yields. Systematic solvent-free syntheses of hierarchically porous aluminophosphate-based zeolites with AEL and AFI structures is presented. XRD patterns and SEM images show that these samples have high crystallinity. N2 sorption isotherm tests show that these samples are hierarchically porous, and their surface areas are comparable with those of corresponding zeolites from hydrothermal route. Chosen as an example, catalytic oxidation of ethylbenzene with O2 shows that cobalt substituted APO-11 from the solvent-free route (S-CoAPO-11) is more active than conventional CoAPO-11 from hydrothermal route owing to the sample hierarchical porosity.
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Risk factors for hypospadias in China.
Asian J. Androl.
PUBLISHED: 05-31-2014
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This case-controlled study was designed to evaluate the association between various baseline parental factors and the risk of hypospadias in China. Patients were selected from tertiary referral hospitals in Anhui, a province in mid-eastern China. A questionnaire was given to the parents of each patient. The final database included 193 cases and 835 controls. The incidence of additional coexistent anomalies was 13.0%, primarily cryptorchidism (9.8%). Ten patients (5.1%) were from families with genital anomaly, including five families (2.6%) with hypospadias. The risks of hypospadias was higher for children of mothers > 35 (odds ratio [OR] =1.47) and < 18 (OR = 2.95) years of age, and in mothers who had consumed alcohol (OR = 2.67), used drugs (OR = 1.53) and had an infection (OR = 1.87) during pregnancy. The risk of hypospadias was also higher when mothers (OR = 1.68) and fathers (OR = 1.74) were engaged in agriculture. Other factors assessed were not associated with the risk of hypospadias.
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Fibrinogen ?-chain-derived peptide is upregulated in hippocampus of rats exposed to acute morphine injection and spontaneous alternation testing.
Pharmacol Res Perspect
PUBLISHED: 05-24-2014
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Fibrinogen is a secreted glycoprotein that is synthesized in the liver, although recent in situ hybridization data support its expression in the brain. It is involved in blood clotting and is released in the brain upon injury. Here, we report changes in the extracellular levels of fibrinogen ?-chain-derived peptides in the brain after injections of saline and morphine. More specifically, in order to assess hippocampus-related working memory, an approach pairing in vivo microdialysis with mass spectrometry was used to characterize extracellular peptide release from the hippocampus of rats in response to saline or morphine injection coupled with a spontaneous alternation task. Two fibrinopeptide A-related peptides derived from the fibrinogen ?-chain-fibrinopeptide A (ADTGTTSEFIEAGGDIR) and a fibrinopeptide A-derived peptide (DTGTTSEFIEAGGDIR)-were shown to be consistently elevated in the hippocampal microdialysate. Fibrinopeptide A was significantly upregulated in rats exposed to morphine and spontaneous alternation testing compared with rats exposed to saline and spontaneous alternation testing (P < 0.001), morphine alone (P < 0.01), or saline alone (P < 0.01), respectively. The increase in fibrinopeptide A in rats subjected to morphine and a memory task suggests that a complex interaction between fibrinogen and morphine takes place in the hippocampus.
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Understanding the effects of the number of pyrazines and their positions on charge-transport properties in silylethynylated N-heteropentacenes.
J Mol Model
PUBLISHED: 05-14-2014
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The charge-transport properties of a series of silylethynylated N-heteropentacenes (TIPS-PEN-xN; x = 2, 4) were systematically investigated using Marcus electron-transfer theory coupled with kinetic Monte Carlo simulations. Electronic structure calculations showed that introducing more pyrazine rings decreases the energy levels of the lowest unoccupied molecular orbitals (LUMOs) and should aid electron transfer. The number and the positions of the pyrazine rings greatly influence the molecular packing in crystals and hence the intermolecular electronic coupling. Furthermore, the introduction of internal (rather than external) pyrazine rings leads to a better charge-transport network. Transport parameters evaluated from the hopping and band-like models both demonstrate that, among the TIPS-PEN-xN molecules, B-TIPS-PEN-4N-which has two internal pyrazine rings-is the most promising n-type material.
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Non-coding RNAs in epithelial immunity to Cryptosporidium infection.
Parasitology
PUBLISHED: 05-14-2014
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Cryptosporidium spp. is a protozoan parasite that infects the gastrointestinal epithelium and causes diarrhoeal disease worldwide. It is one of the most common pathogens responsible for moderate to severe diarrhoea in children younger than 2 years. Because of the 'minimally invasive' nature of Cryptosporidium infection, mucosal epithelial cells are critical to the host's anti-Cryptosporidium immunity. Gastrointestinal epithelial cells not only provide the first and most rapid defence against Cryptosporidium infection, they also mobilize immune effector cells to the infection site to activate adaptive immunity. Recent advances in genomic research have revealed the existence of a large number of non-protein-coding RNA transcripts, so called non-coding RNAs (ncRNAs), in mammalian cells. Some ncRNAs may be key regulators for diverse biological functions, including innate immune responses. Specifically, ncRNAs may modulate epithelial immune responses at every step of the innate immune network following Cryptosporidium infection, including production of antimicrobial molecules, expression of cytokines/chemokines, release of epithelial cell-derived exosomes, and feedback regulation of immune homoeostasis. This review briefly summarizes the current science on ncRNA regulation of innate immunity to Cryptosporidium, with a focus on microRNA-associated epithelial immune responses.
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Hydrogen sulfide reduces kidney injury due to urinary-derived sepsis by inhibiting NF-?B expression, decreasing TNF-? levels and increasing IL-10 levels.
Exp Ther Med
PUBLISHED: 05-08-2014
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The present study aimed to investigate the effect of hydrogen sulfide (H2S) on kidney injury induced by urinary-derived sepsis. Rabbits were randomly divided into control, sham, sepsis, NaHS 2.8 ?mol/kg and NaHS 8.4 ?mol/kg groups, with six rabbits in each group. Upper urinary tract obstruction and acute infection was induced to establish the sepsis model. Blood was collected to carry out a white blood cell (WBC) count, and creatinine (Cr) and blood urea nitrogen (BUN) analysis. Morphological changes were observed by hematoxylin and eosin (H&E) staining and transmission electron microscopy. Immunohistochemical staining was used to detect the expression levels of tumor necrosis factor (TNF)-?, interleukin (IL)-10 and nuclear factor ?-light-chain-enhancer of activated B cells (NF-?B). Cystathionine-?-lyase (CSE) activity was measured by the spectrophotometric methylene blue method and the blood H2S concentration was measured by deproteinization. WBC, Cr and BUN levels were significantly elevated in the sepsis group compared with those in the control group (P<0.05). Following treatment with NaHS, the WBC, Cr and BUN levels were significantly decreased in the NaHS groups compared with those in the sepsis group (P<0.05). The pathological features of kidney injury were also alleviated by NaHS. In the sepsis group, the levels of TNF-?, IL-10 and NF-?B were significantly increased compared with those in the control group (P<0.05). In the NaHS groups, the TNF-? and NF-?B levels were significantly reduced whereas the IL-10 level was significantly increased compared with the respective levels in the sepsis group (P<0.05). The H2S concentration was significantly decreased in the sepsis group and this reduction was attenuated in the NaHS groups (P<0.05). Furthermore, the NaHS 8.4 ?mol/kg dose revealed a more potent effect than the NaHS 2.8 ?mol/kg dose. Thus, exogenous H2S reduced kidney injury from urinary-derived sepsis by decreasing the levels of NF-?B and TNF-?, and increasing the level of IL-10.
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Redox Regulation of Rac1 by Thiol Oxidation.
Free Radic. Biol. Med.
PUBLISHED: 04-29-2014
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The Rac1 GTPase is an essential and ubiquitous protein that signals through numerous pathways to control critical cellular processes, including cell growth, morphology, and motility. Rac1 deletion is embryonic lethal, and its dysregulation or mutation can promote cancer, arthritis, cardiovascular disease, and neurological disorders. Rac1 activity is highly regulated by modulatory proteins and post-translational modifications. While much attention has been devoted to guanine nucleotide exchange factors that act on Rac1 to promote GTP loading and Rac1 activation, cellular oxidants may also regulate Rac1 activation by promoting guanine nucleotide exchange. Herein, we show that Rac1 contains a redox-sensitive cysteine (Cys(18)) that can be selectively oxidized at physiological pH due to its lowered pKa. Consistent with these observations, we show that Rac1 is glutathiolated in primary chondrocytes. Oxidation of Cys(18) by glutathione greatly perturbs Rac1 guanine nucleotide binding and promotes nucleotide exchange. As aspartate substitutions have been previously used to mimic cysteine oxidation, we characterized the biochemical properties of Rac1(C18D). We also evaluated Rac1(C18S) as a redox-insensitive variant and find that it retains structural and biochemical properties similar to Rac1(WT) but is resistant to thiol oxidation. In addition, Rac1(C18D), but not Rac1(C18S), shows greatly enhanced nucleotide exchange, similar to that observed for Rac1 oxidation by glutathione. We employed Rac1(C18D) in cell-based studies to assess whether this fast-cycling variant, which mimics Rac1 oxidation by glutathione, affects Rac1 activity and function. Expression of Rac1(C18D) in Swiss 3T3 cells showed greatly enhanced GTP-bound Rac1 relative to Rac1(WT) and the redox-insensitive Rac1(C18S) variant. Moreover, expression of Rac1(C18D) in HEK-293T cells greatly promoted lamellipodia formation. Our results suggest that Rac1 oxidation at Cys(18) is a novel post-translational modification that upregulates Rac1 activity.
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Bone morphogenetic protein 2 inhibits the proliferation and growth of human colorectal cancer cells.
Oncol. Rep.
PUBLISHED: 04-15-2014
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Colorectal cancer (CRC) is one of the most deadly cancers worldwide. Significant progress has been made in understanding the molecular pathogenesis of CRC, which has led to successful early diagnosis, surgical intervention and combination chemotherapy. However, limited therapeutic options are available for metastatic and/or drug-resistant CRC. While the aberrantly activated Wnt/?-catenin pathway plays a critical initiating role in CRC development, disruption of the bone morphogenetic protein (BMP) pathway causes juvenile polyposis syndrome, suggesting that BMP signaling may play a role in CRC development. However, conflicting results have been reported concerning the possible roles of BMP signaling in sporadic colon cancer. Here, we investigated the effect of BMP2 on the proliferation, migration, invasiveness and tumor growth capability of human CRC cells. Using an adenovirus vector that overexpresses BMP2 and the piggyBac transposon-mediated stable BMP2 overexpression CRC line, we found that exogenous BMP2 effectively inhibited HCT116 cell proliferation and colony formation. BMP2 was shown to suppress colon cancer cell migration and invasiveness. Under a low serum culture condition, forced expression of BMP2 induced a significantly increased level of apoptosis in HCT116 cells. Using a xenograft tumor model, we found that forced expression of BMP2 in HCT116 cells suppressed tumor growth, accompanied by decreased cell proliferation activity. Taken together, our results strongly suggest that BMP2 plays an important inhibitory role in governing the proliferation and aggressive features of human CRC cells.
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Bone morphogenetic protein-9 effectively induces osteo/odontoblastic differentiation of the reversibly immortalized stem cells of dental apical papilla.
Stem Cells Dev.
PUBLISHED: 03-21-2014
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Dental pulp/dentin regeneration using dental stem cells combined with odontogenic factors may offer great promise to treat and/or prevent premature tooth loss. We previously demonstrated that bone morphogenetic protein 9 (BMP9) is one of the most potent factors in inducing bone formation. Here, we investigate whether BMP9 can effectively induce odontogenic differentiation of the stem cells from mouse apical papilla (SCAPs). Using a reversible immortalization system expressing SV40 T flanked with Cre/loxP sites, we demonstrate that the SCAPs can be immortalized, resulting in immortalized SCAPs (iSCAPs) that express mesenchymal stem cell markers. BMP9 upregulates Runx2, Sox9, and PPAR?2 and odontoblastic markers, and induces alkaline phosphatase activity and matrix mineralization in the iSCAPs. Cre-mediated removal of SV40 T antigen decreases iSCAP proliferation. The in vivo stem cell implantation studies indicate that iSCAPs can differentiate into bone, cartilage, and, to lesser extent, adipocytes upon BMP9 stimulation. Our results demonstrate that the conditionally iSCAPs not only maintain long-term cell proliferation but also retain the ability to differentiate into multiple lineages, including osteo/odontoblastic differentiation. Thus, the reversibly iSCAPs may serve as an important tool to study SCAP biology and SCAP translational use in tooth engineering. Further, BMP9 may be explored as a novel and efficacious factor for odontogenic regeneration.
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The 3M complex maintains microtubule and genome integrity.
Mol. Cell
PUBLISHED: 02-22-2014
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CUL7, OBSL1, and CCDC8 genes are mutated in a mutually exclusive manner in 3M and other growth retardation syndromes. The mechanism underlying the function of the three 3M genes in development is not known. We found that OBSL1 and CCDC8 form a complex with CUL7 and regulate the level and centrosomal localization of CUL7, respectively. CUL7 depletion results in altered microtubule dynamics, prometaphase arrest, tetraploidy, and mitotic cell death. These defects are recaptured in CUL7 mutated 3M cells and can be rescued by wild-type, but not by 3M patient-derived CUL7 mutants. Depletion of either OBSL1 or CCDC8 results in defects and sensitizes cells to microtubule damage similarly to loss of CUL7 function. Microtubule damage reduces the level of CCDC8 that is required for the centrosomal localization of CUL7. We propose that CUL7, OBSL1, and CCDC8 proteins form a 3M complex that functions in maintaining microtubule and genome integrity and normal development.
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Improvement of image quality and radiation dose of CT perfusion of the brain by means of low-tube voltage (70 KV).
Eur Radiol
PUBLISHED: 02-18-2014
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To investigate the feasibility of 70 kV cerebral CT perfusion by comparing image quality and radiation exposure to 80 kV.
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Expression and correlation analysis of IL-4, IFN-? and Fc?RI in tonsillar mononuclear cells in patients with IgA nephropathy.
Cell. Immunol.
PUBLISHED: 02-18-2014
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Clinical deterioration of IgA nephropathy (IgAN) is frequently preceded by episodes of upper respiratory tract infection such as tonsillitis. The aim of this study was attempt to investigate the expression and correlation of IL-4, IFN-? and Fc?RI in tonsillar mononuclear cells under stimulations of ?-hemolytic streptococcus (HS) or lipopolysaccharide (LPS) in patients with IgA nephropathy.
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Direct detection of circulating microRNAs in serum of cancer patients by coupling protein-facilitated specific enrichment and rolling circle amplification.
Chem. Commun. (Camb.)
PUBLISHED: 02-14-2014
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We have developed a simple method for direct detection of circulating microRNAs in serum by using the p19 protein-functionalized magnetic beads (PFMBs) for specific enrichment and rolling circle amplification (RCA). The detection limit for microRNAs is 1 fM. Therefore, the proposed method has the potential of being used in the analysis of circulating microRNAs and clinical diagnosis.
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Microbubble-mediated sonoporation amplified lipid peroxidation of Jurkat cells.
Chem. Phys. Lipids
PUBLISHED: 02-12-2014
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Sonoporation is a developing technique used in drug delivery for cancer cells. Low frequency ultrasound is used to trigger the cavitation of microbubbles to puncture the cell membrane, and during this process, lipid metabolism becomes disrupted. In this study, cell viability and the generation of specific oxidized lipid products were assessed in Jurkat cells before and after sonoporation. A reduction in cell viability and an induction of apoptosis of Jurkat cells were found 4 h and 24 h post-sonoporation, respectively. Sonoporation suppressed cholesterol concentration and arachidonic, eicosapentaenoic and docosahexaenoic acids in the Jurkat cells. Levels of enzyme-independent oxidized products (F2-isoprostanes, F3-isoprostanes, 7-ketocholesterol) were elevated by sonoporation compared with the control, whereas enzyme-dependent oxidized products (5(S)-, 9(S)-, 12(S)-, 15(S)- and 20-HETE and 27-hydroxycholesterol) were not altered. Antioxidant enzymes activities were also increased in sonoporated Jurkat cells compared with the control. In this study, the loss of lipids potentially increased the availability for enzyme-independent lipid peroxidation, leading to cell fragility and death.
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Effect of Mild Hypothermia on the Expression of Toll-like Receptor 2 in Lung Tissues with Experimental Acute Lung Injury.
Heart Lung Circ
PUBLISHED: 02-10-2014
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Our study aimed to determine the effect of mild hypothermia (MHT) on the expression of toll-like receptor 2 (TLR2) in lung tissue with acute lung injury. The animals were randomly divided into control, model and mild hypothermia groups.
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Targeting BMP9-promoted human osteosarcoma growth by inactivation of notch signaling.
Curr Cancer Drug Targets
PUBLISHED: 02-02-2014
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Osteosarcoma (OS) is the most common primary malignancy of bone and is usually associated with poor prognosis due to its high incidence of metastasis and chemoresistance. Molecular pathogenesis of OS is poorly understood. We previously showed that OS cells are refractory to BMP9-induced osteogenesis and respond favorably to proliferation and tumor growth. Here we investigate if Notch signaling mediates the BMP9-promoted cell proliferation and tumor growth of human osteosarcoma (OS). We find that the expression of Notch1, Notch2, Notch3, DLL1, JAG1 and JAG2 is readily detected in most of the tested OS cell lines. BMP9-promoted OS cell proliferation, migration, and cell cycle S/G2 progression are effectively inhibited by a dominant-negative mutant of Notch1 (dnNotch1) or the ?-secretase inhibitor Compound E (ComE). Furthermore, BMP9-promoted tumor growth and osteolytic lesions in vivo are significantly inhibited by dnNotch1. BMP9 up-regulates the expression of Notch1, Notch3, DLL1, and JAG1 in OS cells. Accordingly, BMP9 stimulation induces a nuclear accumulation of NICD, which is blocked by ComE. Our results demonstrate that BMP9-promoted OS proliferation and tumor growth is at least in part mediated by Notch signaling, suggesting that osteogenic BMPs may function as upstream regulators of Notch signaling in OS tumorigenesis. Thus, pharmacologic intervention of Notch signaling may be explored as a new therapeutic strategy for human OS tumors.
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Prognostic value of miR-96 in patients with acute myeloid leukemia.
Diagn Pathol
PUBLISHED: 01-28-2014
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Aberrant expression of miRNA (miR)-96 is associated with tumorigenesis and tumor progression in several solid cancers. However, little is known about the expression and prognostic value of miR-96 in acute myeloid leukemia (AML). Therefore, the aim of this study was to investigate the correlation of miR-96 expression with clinicopathological features and prognosis of AML.
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Cryptosporidium parvum induces SIRT1 expression in host epithelial cells through downregulating let-7i.
Hum. Immunol.
PUBLISHED: 01-10-2014
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Epithelial cells along human gastrointestinal mucosal surface express pathogen-recognizing receptors and actively participate in the regulation of inflammatory reactions in response to microbial infection. The NAD-dependent deacetylase sirtuin-1 (SIRT1), one member of the sirtuin family of proteins and an NAD-dependent deacetylase has been implicated in the regulation of multiple cellular processes, including inflammation, longevity, and metabolism. In this study, we demonstrated that infection of cultured human biliary epithelial cells (H69 cholangiocytes) with a parasitic protozoan, Cryptosporidium parvum, induced SIRT1 expression at the protein level without a change in SIRT1 mRNA content. Using real-time PCR and Northern blot analyses, we found that C. parvum infection decreased the expression of let-7i in infected H69 cells. Down-regulation of let-7i caused relief of miRNA-mediated translational suppression of SIRT1 and consequently, resulted in an increased SIRT1 protein level in infected H69 cell cultures. Moreover, gain- and loss-of-function studies revealed that let-7i could modulate NF-?B activation through modification of SIRT1 protein expression. Thus, our data suggest that let-7i regulates SIRT1 expression in human biliary epithelial cells in response to microbial challenge, suggesting a new role of let-7i in the regulation of NF-?B-mediated epithelial innate immune response.
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Activation of the PI3K/Akt/mTOR/p70S6K pathway is involved in S100A4-induced viability and migration in colorectal cancer cells.
Int J Med Sci
PUBLISHED: 01-01-2014
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The S100 protein family member S100A4 regulates various cellular functions. Previous studies have shown that elevated expression of S100A4 is associated with progression and metastasis of colorectal cancer (CRC). However, little is known about whether and how S100A4 contributes to CRC development. In our present study, the elevated expression of S100A4 in CRC tissues compared to matched adjacent normal tissues was confirmed by immunohistochemistry, semi-quantitative RT-PCR and Western blot. Adenovirus-mediated S100A4 overexpression obviously enhanced viability and migration of CRC cells, which was detected by MTT assay and transwell assay, respectively. Additionally, S100A4 overexpression increased the phosphorylation levels of Akt, mTOR and p70S6K. These effects of S100A4 were abolished by treatment with either the specific PI3K/Akt inhibitor LY294002, or the specific mTOR/p70S6K inhibitor rapamycin. Furthermore, overexpression of S100A4 resulted in upregulation of VEGF and downregulation of E-cadherin, which were strongly reversed by either LY294002 or rapamycin. Altogether, our results demonstrate that activation of the PI3K/Akt/mTOR/p70S6K signaling pathway is involved in S100A4-induced viability, migration, upregulation of VEGF and downregulation of E-cadherin in CRC cells.
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The piggyBac transposon-mediated expression of SV40 T antigen efficiently immortalizes mouse embryonic fibroblasts (MEFs).
PLoS ONE
PUBLISHED: 01-01-2014
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Mouse embryonic fibroblasts (MEFs) are mesenchymal stem cell (MSC)-like multipotent progenitor cells and can undergo self-renewal and differentiate into to multiple lineages, including bone, cartilage and adipose. Primary MEFs have limited life span in culture, which thus hampers MEFs' basic research and translational applications. To overcome this challenge, we investigate if piggyBac transposon-mediated expression of SV40 T antigen can effectively immortalize mouse MEFs and that the immortalized MEFs can maintain long-term cell proliferation without compromising their multipotency. Using the piggyBac vector MPH86 which expresses SV40 T antigen flanked with flippase (FLP) recognition target (FRT) sites, we demonstrate that mouse embryonic fibroblasts (MEFs) can be efficiently immortalized. The immortalized MEFs (piMEFs) exhibit an enhanced proliferative activity and maintain long-term cell proliferation, which can be reversed by FLP recombinase. The piMEFs express most MEF markers and retain multipotency as they can differentiate into osteogenic, chondrogenic and adipogenic lineages upon BMP9 stimulation in vitro. Stem cell implantation studies indicate that piMEFs can form bone, cartilage and adipose tissues upon BMP9 stimulation, whereas FLP-mediated removal of SV40 T antigen diminishes the ability of piMEFs to differentiate into these lineages, possibly due to the reduced expansion of progenitor populations. Our results demonstrate that piggyBac transposon-mediated expression of SV40 T can effectively immortalize MEFs and that the reversibly immortalized piMEFs not only maintain long-term cell proliferation but also retain their multipotency. Thus, the high transposition efficiency and the potential footprint-free natures may render piggyBac transposition an effective and safe strategy to immortalize progenitor cells isolated from limited tissue supplies, which is essential for basic and translational studies.
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Characterization of constitutive promoters for piggyBac transposon-mediated stable transgene expression in mesenchymal stem cells (MSCs).
PLoS ONE
PUBLISHED: 01-01-2014
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Multipotent mesenchymal stem cells (MSCs) can undergo self-renewal and give rise to multi-lineages under given differentiation cues. It is frequently desirable to achieve a stable and high level of transgene expression in MSCs in order to elucidate possible molecular mechanisms through which MSC self-renewal and lineage commitment are regulated. Retroviral or lentiviral vector-mediated gene expression in MSCs usually decreases over time. Here, we choose to use the piggyBac transposon system and conduct a systematic comparison of six commonly-used constitutive promoters for their abilities to drive RFP or firefly luciferase expression in somatic HEK-293 cells and MSC iMEF cells. The analyzed promoters include three viral promoters (CMV, CMV-IVS, and SV40), one housekeeping gene promoter (UbC), and two composite promoters of viral and housekeeping gene promoters (hEFH and CAG-hEFH). CMV-derived promoters are shown to drive the highest transgene expression in HEK-293 cells, which is however significantly reduced in MSCs. Conversely, the composite promoter hEFH exhibits the highest transgene expression in MSCs whereas its promoter activity is modest in HEK-293 cells. The reduced transgene expression driven by CMV promoters in MSCs may be at least in part caused by DNA methylation, or to a lesser extent histone deacetlyation. However, the hEFH promoter is not significantly affected by these epigenetic modifications. Taken together, our results demonstrate that the hEFH composite promoter may be an ideal promoter to drive long-term and high level transgene expression using the piggyBac transposon vector in progenitor cells such as MSCs.
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Adenovirus-mediated efficient gene transfer into cultured three-dimensional organoids.
PLoS ONE
PUBLISHED: 01-01-2014
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Three-dimensional organoids have been recently established from various tissue-specific progenitors (such as intestinal stem cells), induced pluripotent stem cells, or embryonic stem cells. These cultured self-sustaining stem cell-based organoids may become valuable systems to study the roles of tissue-specific stem cells in tissue genesis and disease development. It is thus conceivable that effective genetic manipulations in such organoids may allow us to reconstruct disease processes and/or develop novel therapeutics. Recombinant adenoviruses are one of the most commonly used viral vectors for in vitro and in vivo gene deliveries. In this study, we investigate if adenoviruses can be used to effectively deliver transgenes into the cultured "mini-gut" organoids derived from intestinal stem cells. Using adenoviral vectors that express fluorescent proteins, we demonstrate that adenoviruses can effectively deliver transgenes into the cultured 3-D "mini-gut" organoids. The transgene expression can last at least 10 days in the cultured organoids. As a proof-of-principle experiment, we demonstrate that adenovirus-mediated noggin expression effectively support the survival and self-renewal of mini-gut organoids, while adenovirus-mediated expression of BMP4 inhibits the self-sustainability and proliferation of the organoids. Thus, our results strongly suggest that adenovirus vectors can be explored as effective gene delivery vehicles to introduce genetic manipulations in 3-D organoids.
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Single-site sonoporation disrupts actin cytoskeleton organization.
J R Soc Interface
PUBLISHED: 01-01-2014
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Sonoporation is based upon an ultrasound-microbubble cavitation routine that physically punctures the plasma membrane on a transient basis. During such a process, the actin cytoskeleton may be disrupted in tandem because this network of subcellular filaments is physically interconnected with the plasma membrane. Here, by performing confocal fluorescence imaging of single-site sonoporation episodes induced by ultrasound-triggered collapse of a single targeted microbubble, we directly observed immediate rupturing of filamentary actin (F-actin) at the sonoporation site (cell type: ZR-75-30; ultrasound frequency: 1 MHz; peak negative pressure: 0.45 MPa; pulse duration: 30 cycles; bubble diameter: 2-4 µm). Also, through conducting a structure tensor analysis, we observed further disassembly of the F-actin network over the next 60 min after the onset of sonoporation. The extent of F-actin disruption was found to be more substantial in cells with higher uptake of sonoporation tracer. Commensurate with this process, cytoplasmic accumulation of globular actin (G-actin) was evident in sonoporated cells, and in turn the G-actin : F-actin ratio was increased in a trend similar to drug-induced (cytochalasin D) actin depolymerization. These results demonstrate that sonoporation is not solely a membrane-level phenomenon: organization of the actin cytoskeleton is concomitantly perturbed.
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Adenovirus-mediated gene transfer in mesenchymal stem cells can be significantly enhanced by the cationic polymer polybrene.
PLoS ONE
PUBLISHED: 01-01-2014
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Mesenchymal stem cells (MSCs) are multipotent progenitors, which can undergo self-renewal and give rise to multi-lineages. A great deal of attentions have been paid to their potential use in regenerative medicine as potential therapeutic genes can be introduced into MSCs. Genetic manipulations in MSCs requires effective gene deliveries. Recombinant adenoviruses are widely used gene transfer vectors. We have found that although MSCs can be infected in vitro by adenoviruses, high virus titers are needed to achieve high efficiency. Here, we investigate if the commonly-used cationic polymer Polybrene can potentiate adenovirus-mediated transgene delivery into MSCs, such as C2C12 cells and iMEFs. Using the AdRFP adenovirus, we find that AdRFP transduction efficiency is significantly increased by Polybrene in a dose-dependent fashion peaking at 8 ?g/ml in C2C12 and iMEFs cells. Quantitative luciferase assay reveals that Polybrene significantly enhances AdFLuc-mediated luciferase activity in C2C12 and iMEFs at as low as 4 ?g/ml and 2 ?g/ml, respectively. FACS analysis indicates that Polybrene (at 4 ?g/ml) increases the percentage of RFP-positive cells by approximately 430 folds in AdRFP-transduced iMEFs, suggesting Polybrene may increase adenovirus infection efficiency. Furthermore, Polybrene can enhance AdBMP9-induced osteogenic differentiation of MSCs as early osteogenic marker alkaline phosphatase activity can be increased more than 73 folds by Polybrene (4 ?g/ml) in AdBMP9-transduced iMEFs. No cytotoxicity was observed in C2C12 and iMEFs at Polybrene up to 40 ?g/ml, which is about 10-fold higher than the effective concentration required to enhance adenovirus transduction in MSCs. Taken together, our results demonstrate that Polybrene should be routinely used as a safe, effective and inexpensive augmenting agent for adenovirus-mediated gene transfer in MSCs, as well as other types of mammalian cells.
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Th1/Th2 polarization in tonsillar lymphocyte form patients with IgA nephropathy.
Ren Fail
PUBLISHED: 12-03-2013
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Abstract Imbalance of Th1/Th2 pro-inflammatory cytokines plays an important role in the development and progression of IgA nephropathy (IgAN). Clinical development and exacerbation of IgAN are frequently preceded by episodes of upper respiratory tract infection, and palatine tonsils represent the predominant immunocompetent tissue of the upper respiratory tract. This study examined tonsillar lymphocytes of IgAN who suffered from tonsillitis (n?=?22), and using tonsils derived from patients with chronic tonsillitis (n?=?24) but without renal disease as a control. We identified a polarization toward Th2 response in tonsils of IgAN patients. TH0 cells are differentially mobilized during contact sensitization and by adjuvants such as lipopolysaccharide (LPS) that induce T-helper type 1 (Th1) responses, or ?-hemolytic streptococcus (HS) that induces T-helper type 2 (Th2) responses. Th1:Th2 ratio is correlated with proteinuria and renal pathologic changes in IgAN group. Our study suggests that IgAN is associated with the change in Th1/Th2 balance in favor of Th2 lymphocytes.
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Radix tetrastigma hemsleyani flavone induces apoptosis in human lung carcinoma a549 cells by modulating the MAPK pathway.
Asian Pac. J. Cancer Prev.
PUBLISHED: 12-03-2013
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Radix Tetrastigma Hemsleyani Flavone (RTHF) is widely used as a traditional herb for its detoxification and anti-inflammation activity. Recently, several studies have shown that RTHF can inhibit growth and induce apoptosis in human cancer cell lines. However, the mechanisms are not completely understood yet. In this study we investigated the potential effects of RTHF on growth and apoptosis in human lung adenocarcinoma A549 cells as well as its mechanisms. A549 cells were treated with RTHF at various concentrations for different times. In vitro the MTT assay showed that RTHF had obvious anti-proliferation effects on A549 cells in a dose- and time- dependent manner. Cell morphological changes observed by inverted microscope and Hoechst33258 methods were compared with apoptotic changes observed by fluorescence microscope. Cell apoptosis inspected by flow cytometry showed significant increase in the treatment group over the control group (P<0.01). Expression of apoptosis related Bax/Bcl-2, caspases and MAPK pathway proteins were detected by Western blotting. The results showed that RTHF up-regulated the Bax/Bcl-2 ratio and cle-caspase3/9, cle-PARP expression in a dose- dependent manner. Expression of p-p38 increased, p-ERK decreased significantly and that of p-JNK was little changed in the RTHF group when compared with the control group. These results suggest that RTHF might exert anti-growth and apoptosis activity against lung cancer A549 cells through activation of caspases and Bcl-2 family proteins and the MAPK pathway, therefore presenting as a promising therapeutic agent for the treatment of lung cancer.
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Amplified spontaneous emission and lasing from lanthanide-doped up-conversion nanocrystals.
ACS Nano
PUBLISHED: 12-02-2013
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Lanthanide-doped nanocrystals (NCs), which found applications in bioimaging and labeling, have recently demonstrated significant improvement in up-conversion efficiency. Here, we report the first up-conversion multicolor microcavity lasers by using NaYF4:Yb/Er@NaYF4 core-shell NCs as the gain medium. It is shown that the optical gain of the NCs, which arises from the 2- and 3-photon up-conversion processes, can be maximized via sequential pulses pumping. Amplified spontaneous emission is observed from a Fabry-Perot cavity containing the NCs dispersed in cyclohexane solution. By coating a drop of silica resin containing the NCs onto an optical fiber, a microcavity with a bottle-like geometry is fabricated. It is demonstrated that the microcavity supports lasing emission through the formation of whispering gallery modes.
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Comparison of the Membrane Proteome of Virulent Mycobacterium tuberculosis and the Attenuated Mycobacterium bovis BCG Vaccine Strain by Label-Free Quantitative Proteomics.
J. Proteome Res.
PUBLISHED: 10-28-2013
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The Mycobacterium tuberculosis membrane is rich in antigens that are potential targets for diagnostics and the development of new vaccines. To better understand the mechanisms underlying MTB virulence and identify new targets for therapeutic intervention, we investigated the differential composition of membrane proteomes between virulent M. tuberculosis H37Rv (MTB) and the Mycobacterium bovis BCG vaccine strain. To compare the membrane proteomes, we used LC-MS/MS analysis in combination with label-free quantitative proteomics, utilizing the area under the curve of the extracted ion chromatograms of peptides obtained from m/z and retention time alignment of MS1 features. With this approach, we obtained relative abundance ratios for 2203 identified membrane-associated proteins in high confidence. Of these proteins, 294 showed statistically significant differences of at least two fold in relative abundance between MTB and BCG membrane fractions. Our comparative analysis detected several proteins associated with known genomic regions of difference between MTB and BCG as being absent, which validated the accuracy of our approach. In further support of our label-free quantitative data, we verified select protein differences by immunoblotting. To our knowledge, we have generated the first comprehensive and high-coverage profile of comparative membrane proteome changes between virulent MTB and its attenuated relative BCG, which helps elucidate the proteomic basis of the intrinsic virulence of the MTB pathogen.
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Quantitative proteomic dissection of a native 14-3-3? interacting protein complex associated with hepatocellular carcinoma.
Amino Acids
PUBLISHED: 10-26-2013
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The 14-3-3 proteins regulate diverse biological processes that are implicated in cancer development, and seven 14-3-3 isoforms were identified with isoform-specific roles in different human tumors. In our previous work, we dissected the interactome of 14-3-3? formed during the DNA damage response in a hepatocellular carcinoma (HCC) cell using an AACT/SILAC-based quantitative proteomic approach. In this study, we used a similar proteomic approach to profile/identify the 14-3-3? interactome formed in native HCC cells. Functional categorization and data-dependent network analysis of the native HCC-specific 14-3-3? interactome revealed that 14-3-3? is involved in the regulation of multiple biological processes (BPs)/pathways, including cell cycle control, apoptosis, signal transduction, transport, cell adhesion, carbohydrate metabolism, and nucleic acid metabolism. Biological validation further supports that 14-3-3?, via association with multiple BP/pathway-specific proteins, coordinates the regulation of proliferation, survival, and metastasis of HCC. The findings in this study, together with those of our previous study, provide an extensive profile of the 14-3-3? interaction network in HCC cells, which should be valuable for understanding the pathology of HCC and HCC therapy.
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S100A6 stimulates proliferation and migration of colorectal carcinoma cells through activation of the MAPK pathways.
Int. J. Oncol.
PUBLISHED: 10-25-2013
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The S100A6 protein, a member of the S100 protein family, is overexpressed in many tumors including colorectal carcinoma (CRC). Although recent studies showed that the elevated expression of S100A6 was associated with the stage and lymphatic permeation of CRC, little is known about whether and how S100A6 contributes to CRC development. Here we investigated the S100A6 expression in CRC tissues and cell lines, and explored the molecular mechanisms underlying the role of S100A6 in CRC development by examining cell proliferation and migration in vitro, and tumorigenicity in nude mice. The results show that S100A6 expression was markedly increased in CRC tissues and cell lines compared to normal colon tissues and a normal colon mucosal epithelial cell line, respectively. Recombinant adenovirus-mediated overexpression of S100A6 or treatment with recombinant S100A6 protein in HCT116, a CRC cell line with relative low S100A6 expression, resulted in enhanced cell proliferation and migration, and the mitogen-activated protein kinase (MAPK) activation in vitro, and tumor growth in vivo. Conversely, RNAi-mediated knockdown of S100A6 in LoVo, a CRC cell line with relative high S100A6 expression, resulted in reduced cell proliferation, migration and MAPK activity. S100A6-induced proliferation was partially attenuated by an ERK inhibitor while migration was suppressed by a p38 inhibitor. Taken together, our results suggest that the cellular effects of S100A6 are mediated by the ERK and p38 MAPK pathways, and modulation of these pathways may be employed for CRC prevention and therapy.
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Navigation system with real-time finite element analysis for minimally invasive surgery.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 10-11-2013
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This paper presents a navigation system for minimally invasive surgery, especially laparoscopic surgery in which operates in abdomen. Conventional navigation systems show virtual images by superimposing models of target tissues on real endoscopic images. Since soft tissues within the abdomen are deformed during the surgery, the navigation system needs to provide surgeons reliable information by deforming the models according to their biomechanical behavior. However, conventional navigation systems dont consider the tissue deformation during the surgery. We have been developing a new real-time FEM-based simulation for deforming a soft tissue model by using neural network[1]. The network is called the neuroFEM. The incorporation of the neuroFEM into the navigation leads to improve the accuracy of the navigation system. In this paper, we propose a new navigation system with a framework of the neuroFEM.
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Influence of cartilage extracellular matrix molecules on cell phenotype and neocartilage formation.
Tissue Eng Part A
PUBLISHED: 09-25-2013
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Interaction between chondrocytes and the cartilage extracellular matrix (ECM) is essential for maintaining the cartilages role as a low-friction and load-bearing tissue. In this study, we examined the influence of cartilage zone-specific ECM on human articular chondrocytes (HAC) in two-dimensional and three-dimensional (3D) environments. Two culture systems were used. SYSTEM 1: HAC were cultured on cell-culture plates that had been precoated with the following ECM molecules for 7 days: decorin, biglycan, tenascin C (superficial zone), collagen type II, hyaluronan (HA) (middle and deep zones), and osteopontin (deep zone). Uncoated standard culture plates were used as controls. Expanded cells were examined for phenotypic changes using real-time polymerase chain reaction. In addition, expanded cells were placed into high-density pellet cultures for 14 days. Neocartilage formation was assessed via gene expression and histology evaluations. SYSTEM 2: HAC that were cultured on untreated plates and encapsulated in a 3D alginate scaffold were mixed with one of the zone-specific ECM molecules. Cell viability, gene expression, and histology assessments were conducted on 14-day-old tissues. In HAC monolayer culture, exposure to decorin, HA, and osteopontin increased COL2A1 and aggrecan messenger RNA (mRNA) levels compared with controls. Biglycan up-regulated aggrecan without a significant impact on COL2A1 expression; Tenascin C reduced COL2A1 expression. Neocartilage formed after preculture on tenascin C and collagen type II expressed higher COL2A1 mRNA compared with control pellets. Preculture of HAC on HA decreased both COL2A1 and aggrecan expression levels compared with controls, which was consistent with histology. Reduced proteoglycan 4 (PRG4) mRNA levels were observed in HAC pellets that had been precultured with biglycan and collagen type II. Exposing HAC to HA directly in 3D-alginate culture most effectively induced neocartilage formation, showing increased COL2A1 and aggrecan, and reduced COL1A1 compared with controls. Decorin treatments increased HAC COL2A1 mRNA levels. These data indicate that an appropriate exposure to cartilage-specific ECM proteins could be used to enhance cartilage formation and to even induce the formation of zone-specific phenotypes to improve cartilage regeneration.
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Destabilization of Heterologous Proteins Mediated by the GSK3? Phosphorylation Domain of the ?-Catenin Protein.
Cell. Physiol. Biochem.
PUBLISHED: 09-23-2013
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Background and Aims : Wnt/?-catenin signaling plays important roles in development and cellular processes. The hallmark of canonical Wnt signaling activation is the stabilization of ?-catenin protein in cytoplasm and/or nucleus. The stability of ?-catenin is the key to its biological functions and is controlled by the phosphorylation of its amino-terminal degradation domain. Aberrant activation of ?-catenin signaling has been implicated in the development of human cancers. It has been recently suggested that GSK3?may play an essential role in regulating global protein turnover. Here, we investigate if the GSK3? phosphorylation site-containing degradation domain of ?-catenin is sufficient to destabilize heterologous proteins. Methods and Results : We engineer chimeric proteins by fusing ?-catenin degradation domain at the N- and/or C-termini of the enhanced green fluorescent protein (eGFP). In both transient and stable expression experiments, the chimeric GFP proteins exhibit a significantly decreased stability, which can be effectively antagonized by lithium and Wnt1. An activating mutation in the destruction domain significantly stabilizes the fusion protein. Furthermore, GSK3 inhibitor SB-216763 effectively increases the GFP signal of the fusion protein. Conversely, the inhibition of Wnt signaling with tankyrase inhibitor XAV939 results in a decrease in GFP signal of the fusion proteins, while these small molecules have no significant effects on the mutant destruction domain-GFP fusion protein. Conclusion: Our findings strongly suggest that the ?-catenin degradation domain may be sufficient to destabilize heterologous proteins in Wnt signaling-dependent manner. It is conceivable that the chimeric GFP proteins may be used as a functional reporter to measure the dynamic status of ?-catenin signaling, and to identify potential anticancer drugs that target ?-catenin signaling. © 2013 S. Karger AG, Basel.
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The E-F hand calcium-binding protein S100A4 regulates the proliferation, survival and differentiation potential of human osteosarcoma cells.
Cell. Physiol. Biochem.
PUBLISHED: 09-16-2013
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Osteosarcoma (OS) is the most common primary bone malignancy in children and young adults. Molecular mechanisms underlying the pathogenesis of OS remain to be fully understood. Several members of the E-F hand calcium-binding S100 protein family are differentially expressed in human cancers. We previously showed that S100A6 is highly expressed in OS tumors. In this study, we investigated the role of S100A4 in regulating OS proliferation and osteogenic differentiation.
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Characterization of scaffold carriers for BMP9-transduced osteoblastic progenitor cells in bone regeneration.
J Biomed Mater Res A
PUBLISHED: 08-23-2013
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Successful bone tissue engineering at least requires sufficient osteoblast progenitors, efficient osteoinductive factors, and biocompatible scaffolding materials. We have demonstrated that BMP9 is one of the most potent factors in inducing osteogenic differentiation of mesenchymal progenitors. To facilitate the potential use of cell-based BMP9 gene therapy for bone regeneration, we characterize the in vivo osteoconductive activities and bone regeneration potential of three clinically-used scaffold materials, type I collagen sponge, hydroxyapatite-tricalcium phosphate (HA-TCP) and demineralized bone matrix (DBM), using BMP9-expressing C2C12 osteoblastic progenitor cells. We find that recombinant adenovirus-mediated BMP9 expression effectively induces osteogenic differentiation in C2C12 cells. Although direct subcutaneous injection of BMP9-transduced C2C12 cells forms ectopic bony masses, subcutaneous implantation of BMP9-expressing C2C12 cells with collagen sponge or HA-TCP scaffold yields the most robust and mature cancellous bone formation, whereas the DBM carrier group forms no or minimal bone masses. Our results suggest that collagen sponge and HA-TCP scaffold carriers may provide more cell-friendly environment to support the survival, propagation, and ultimately differentiation of BMP9-expressing progenitor cells. This line of investigation should provide important experimental evidence for further pre-clinical studies in BMP9-mediated cell based approach to bone tissue engineering.
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Upconverting Near-Infrared Light through Energy Management in Core-Shell-Shell Nanoparticles.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 08-03-2013
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Blue emission at NIR excitation: A strategy, based on energy management in nanostructured materials, is reported for photon upconversion of near-infrared light. Several optical processes can be integrated into a single nanoparticle. The effect offers upconversion emissions spanning from ultraviolet to the visible spectral region by excitation at 808?nm.
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Activation of the interleukin-4/signal transducer and activator of transcription 6 signaling pathway and homeodomain-interacting protein kinase 2 production by tonsillar mononuclear cells in IgA nephropathy.
Am. J. Nephrol.
PUBLISHED: 07-25-2013
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Clinical development and exacerbation of IgA nephropathy (IgAN) are frequently preceded by episodes of upper respiratory tract infection such as tonsillitis. This study aimed to determine the role of the interleukin-4 (IL-4)/signal transducer and activator of transcription 6 (STAT6) signaling pathway and homeodomain-interacting protein kinase 2 (HIPK2) in aberrant IgA1 O-glycosylation production, and identify potential therapeutic targets in IgAN.
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Inhibition of histone deacetylases potentiates BMP9-induced osteogenic signaling in mouse mesenchymal stem cells.
Cell. Physiol. Biochem.
PUBLISHED: 07-19-2013
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We have demonstrated that bone morphogenetic protein 9 (BMP9) is one of the most potent BMPs in regulating osteoblast differentiation of mesenchymal stem cells (MSCs) although the molecular mechanism underlying BMP9-induced osteogenesis remains to be fully elucidated. It is known that epigenetic regulations play an important role in regulating the stem cell potency and lineage commitment. Here, we investigate if the inhibition of histone deacetylases (Hdacs) affects BMP9-induced osteogenic differentiation of MSCs.
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A difunctional DNA-AuNP dendrimer coupling DNAzyme with intercalators for femtomolar detection of nucleic acids.
Chem. Commun. (Camb.)
PUBLISHED: 07-16-2013
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A novel difunctional DNA-nanogold (AuNP) dendrimer with a hemin-G-quadruplex was for the first time utilized as the nanotag for the in situ amplified electronic signal for nucleic acid detection by coupling high-efficiency DNAzyme with the intercalated methylene blue (MB).
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Reversible acetylation regulates acetate and propionate metabolism in Mycobacterium smegmatis.
Microbiology (Reading, Engl.)
PUBLISHED: 06-27-2013
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Carbon metabolic pathways are important to the pathogenesis of Mycobacterium tuberculosis, the causative agent of tuberculosis. However, extremely little is known about metabolic regulation in mycobacteria. There is growing evidence for lysine acetylation being a mechanism of regulating bacterial metabolism. Lysine acetylation is a post-translational modification in which an acetyl group is covalently attached to the side chain of a lysine residue. This modification is mediated by acetyltransferases, which add acetyl groups, and deacetylases, which remove the acetyl groups. Here we set out to test whether lysine acetylation and deacetylation impact acetate metabolism in the model mycobacteria Mycobacterium smegmatis, which possesses 25 candidate acetyltransferases and 3 putative lysine deacetylases. Using mutants lacking predicted acetyltransferases and deacetylases we showed that acetate metabolism in M. smegmatis is regulated by reversible acetylation of acetyl-CoA synthetase (Ms-Acs) through the action of a single pair of enzymes: the acetyltransferase Ms-PatA and the sirtuin deacetylase Ms-SrtN. We also confirmed that the role of Ms-PatA in regulating Ms-Acs regulation depends on cAMP binding. We additionally demonstrated a role for Ms-Acs, Ms-PatA and Ms-SrtN in regulating the metabolism of propionate in M. smegmatis. Finally, along with Ms-Acs, we identified a candidate propionyl-CoA synthetase, Ms5404, as acetylated in whole-cell lysates. This work lays the foundation for studying the regulatory circuit of acetylation and deacetylation in the cellular context of mycobacteria.
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Combined mesophilic anaerobic and thermophilic aerobic digestion process: effect on sludge degradation and variation of sludge property.
Appl. Biochem. Biotechnol.
PUBLISHED: 06-18-2013
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One-stage autothermal thermophilic aerobic digestion (ATAD) is effective for the reduction of volatile solids (VSs) and pathogen in sewage sludges. A novel process of combining mesophilic (<35 °C) anaerobic digestion with a thermophilic (55 °C) aerobic digestion process (AN/TAD) occurred in a one-stage digester, which was designed for aeration energy savings. The efficiency of sludge degradation and variation of sludge properties by batch experiments were evaluated for the AN/TAD digester with an effective volume of 23 L for 30 days compared with conventional thermophilic aerobic digestion (TAD). The AN/TAD system can efficiently achieve sludge stabilization on the 16th day with a VS removal rate of 38.1 %. The AN/TAD system was operated at lower ORP values in a digestion period with higher contents of total organic compounds, volatile fatty acids, protein, and polysaccharide in the soluble phase than those of the TAD system, which can rapidly decreased and had low values in the late period of digestion for the AN/TAD system. In the AN/TAD system, intracellular substances had lysis because of initial hydrolytic acidification.
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Cerium oxide-triggered one-to-many catalytic cycling strategy for in situ amplified electronic signal of low-abundance protein.
Analyst
PUBLISHED: 06-14-2013
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Multifunctionalized thionine-modified cerium oxide (Thi-CeO2) nanostructures with redox ability and catalytic activity were designed as the bionanolabels for in situ amplified electronic signal of low-abundance protein (carcinoembryonic antigen, CEA, used as a model) based on a cerium oxide-triggered one-to-many catalytic cycling strategy. Initially, the carried CeO2 nanoparticles autocatalytically hydrolyzed the phosphate ester bond of l-ascorbic acid 2-phosphate (AAP) to produce a new reactant (l-ascorbic acid, AA), then the generated AA was electrochemically oxidized by the assembled thionine on the Thi-CeO2, and the resultant product was then reduced back to AA by the added tris(2-carboxyethy)phosphine (TCEP). The catalytic cycling could be re-triggered by the thionine and TCEP, resulting in amplification of the electrochemical signal. Under the optimized conditions, the electrochemical immunosensor exhibited a wide linear range of 0.1 pg mL(-1) to 80 ng mL(-1) with a low detection limit of 0.08 pg mL(-1) CEA at the 3?blank level. In addition, the methodology was evaluated for the analysis of clinical serum samples, and was in good accordance with values obtained using the commercialized enzyme-linked immunosorbent assay (ELISA) method.
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Noggin resistance contributes to the potent osteogenic capability of BMP9 in mesenchymal stem cells.
J. Orthop. Res.
PUBLISHED: 06-07-2013
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Mesenchymal stem cells (MSCs) are multipotent progenitors and can differentiate into osteogenic, chondrogenic, and adipogenic lineages. Bone morphogenetic proteins (BMPs) play important roles in stem cell proliferation and differentiation. We recently demonstrated that BMP9 is a potent but less understood osteogenic factor. We previously found that BMP9-induced ectopic bone formation is not inhibited by BMP3. Here, we investigate the effect of BMP antagonist noggin on BMP9-induced osteogenic differentiation. BMP antagonists noggin, chording, gremlin, follistatin, and BMP3 are highly expressed in MSCs, while noggin and follistatin are lowly expressed in more differentiated pre-osteoblast C2C12 cells. BMP9-induced osteogenic markers and matrix mineralization are not inhibited by noggin, while noggin blunts BMP2, BMP4, BMP6, and BMP7-induced osteogenic markers and mineralization. Likewise, ectopic bone formation by MSCs transduced with BMP9, but not the other four BMPs, is resistant to noggin inhibition. BMP9-induced nuclear translocation of Smad1/5/8 is not affected by noggin, while noggin blocks BMP2-induced activation of Smad1/5/8 in MSCs. Noggin fails to inhibit BMP9-induced expression of downstream targets in MSCs. Thus, our results strongly suggest that BMP9 may effectively overcome noggin inhibition, which should at least in part contribute to BMP9s potent osteogenic capability in MSCs.
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Enhanced reversibility and unusual microstructure of a phase-transforming material.
Nature
PUBLISHED: 05-15-2013
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Materials undergoing reversible solid-to-solid martensitic phase transformations are desirable for applications in medical sensors and actuators, eco-friendly refrigerators and energy conversion devices. The ability to pass back and forth through the phase transformation many times without degradation of properties (termed reversibility) is critical for these applications. Materials tuned to satisfy a certain geometric compatibility condition have been shown to exhibit high reversibility, measured by low hysteresis and small migration of transformation temperature under cycling. Recently, stronger compatibility conditions called the cofactor conditions have been proposed theoretically to achieve even better reversibility. Here we report the enhanced reversibility and unusual microstructure of the first martensitic material, Zn45Au30Cu25, that closely satisfies the cofactor conditions. We observe four striking properties of this material. (1) Despite a transformation strain of 8%, the transformation temperature shifts less than 0.5?°C after more than 16,000 thermal cycles. For comparison, the transformation temperature of the ubiquitous NiTi alloy shifts up to 20?°C in the first 20 cycles. (2) The hysteresis remains approximately 2?°C during this cycling. For comparison, the hysteresis of the NiTi alloy is up to 70?°C (refs 9, 12). (3) The alloy exhibits an unusual riverine microstructure of martensite not seen in other martensites. (4) Unlike that of typical polycrystal martensites, its microstructure changes drastically in consecutive transformation cycles, whereas macroscopic properties such as transformation temperature and latent heat are nearly reproducible. These results promise a concrete strategy for seeking ultra-reliable martensitic materials.
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14-3-3? boosts bleomycin-induced DNA damage response by inhibiting the drug-resistant activity of MVP.
J. Proteome Res.
PUBLISHED: 05-09-2013
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Major vault protein (MVP) is the predominant constituent of the vault particle, the largest known ribonuclear protein complex. Although emerging evidence have been establishing the links between MVP (vault) and multidrug resistance (MDR), little is known regarding exactly how the MDR activity of MVP is modulated during cellular response to drug-induced DNA damage (DDR). Bleomycin (BLM), an anticancer drug, induces DNA double-stranded breaks (DSBs) and consequently triggers the cellular DDR. Due to its physiological implications in hepatocellular carcinoma (HCC) and cell fate decision, 14-3-3? was chosen as the pathway-specific bait protein to identify the critical target(s) responsible for HCC MDR. By using an LC-MS/MS-based proteomic approach, MVP was first identified in the BLM-induced 14-3-3? interactome formed in HCC cells. Biological characterization revealed that MVP possesses specific activity to promote the resistance to the BLM-induced DDR. On the other hand, 14-3-3? enhances BLM-induced DDR by interacting with MVP. Mechanistic investigation further revealed that 14-3-3?, in a phosphorylation-dependent manner, binds to the phosphorylated sites at both Thr52 and Ser864 of the monomer of MVP. Consequently, the phosphorylation-dependent binding between 14-3-3? and MVP inhibits the drug-resistant activity of MVP for an enhanced DDR to BLM treatment. Our findings provide an insight into the mechanism underlying how the BLM-induced interaction between 14-3-3? and MVP modulates MDR, implicating novel strategy to overcome the chemotherapeutic resistance through interfering specific protein-protein interactions.
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Ultrasensitive electrochemical detection of cancer-associated circulating microRNA in serum samples based on DNA concatamers.
Biosens Bioelectron
PUBLISHED: 04-25-2013
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MicroRNAs (miRNAs), a kind of endogenous, noncoding RNAs (19-24 nucleotides), play vital roles in regulating gene expression and cellular processes. In recent years, it has been found that circulating miRNAs are differentially expressed in patients and healthy controls. This leads to the suggestion that circulating miRNAs are promising biomarkers for cancer classification and prognosis. However, it is still difficult to detect circulating miRNAs directly from real samples such as human serum without prior extraction and purification. In this work, we developed an ultrasensitive electrochemical biosensor for detection of cancer-associated circulating miRNAs based on DNA concatamers amplification. The proposed biosensor showed a high sensitivity for target miRNA-21 in a concentration range from 100 aM to 100 pM with a detection limit of 100 aM. Furthermore, the biosensor was successfully employed for direct detection of circulating miRNAs in human serum. Due to the high sensitivity, good selectivity and stability, the proposed electrochemical biosensor might have potential clinical application for circulating miRNAs in relation to diagnosis and prognosis.
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Ulinastatin reduces urinary sepsis?related inflammation by upregulating IL?10 and downregulating TNF?? levels.
Mol Med Rep
PUBLISHED: 04-09-2013
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The aim of the present study was to determine the efficacy of ulinastatin (UTI) for the treatment of sepsis and to investigate the associated molecular mechanisms. Twenty?four male rabbits were randomly divided into 4 groups, the normal, sham, sepsis model and UTI groups, each containing 6 rabbits. Serum levels of interleukin (IL)?10 and tumor necrosis factor?? (TNF??) were measured by enzyme?linked immunosorbent assay (ELISA). Liver, kidney and lung tissues were stained with hematoxylin and eosin (H&E) 36 h after sacrifice and morphological changes were observed under an optical microscope. The expression levels of IL?10 and TNF?? proteins in rabbit kidney tissue in each group were determined by immunohistochemical detection and western blot analysis. ELISA results indicated that, compared with the sepsis model, IL?10 levels were significantly higher in the UTI treatment group (183.91±11.521 pg/ml) at 36 h (P=0.000), while serum TNF?? concentration decreased significantly in the UTI treatment group (31.637±2.770 pg/ml; P=0.000). Results of western blot analysis were consistent with the immunohistochemistry, indicating that UTI upregulates IL?10 and downregulates TNF?? levels. In the current study, UTI was demonstrated to effectively treat urinary sepsis and alleviate the inflammatory response in tissues. These effects were mediated by the upregulation of IL?10 and downregulation of TNF?? levels.
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PPE38 of Mycobacterium marinum triggers the cross-talk of multiple pathways involved in the host response, as revealed by subcellular quantitative proteomics.
J. Proteome Res.
PUBLISHED: 04-08-2013
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The PE/PPE family of proteins which are in high abundance in pathogenic species such as Mycobacterium tuberculosis and M. marinum , play the critical role in generating antigenic variation and evasion of host immune responses. However, little is known about their functional roles in mycobacterial pathogenesis. Previously, we found that PPE38 is associated with the virulence of mycobacteria, presumably by modulating the host immune response. To clarify the link between PPE38 and host response, we employed a subcellular, amino acid-coded mass tagging (AACT)/SILAC-based quantitative proteomic approach to determine the proteome changes during host response to M. marinum PPE38. As a result, 291 or 290 proteins were found respectively to be up- or down-regulated in the nucleus. Meanwhile, 576 upregulated and 272 downregulated proteins were respectively detected in the cytosol. The data of quantitative proteomic changes and concurrent biological validations revealed that M. marinum PPE38 could trigger extensive inflammatory responses in macrophages, probably through interacting with toll-like receptor 2 (TLR2). We also found that PPE38 may arrest MHC-1 processing and presentation in infected macrophages. Using bioinformatics tools to analyze global changes in the host proteome, we obtained a PPE38-respondor network involved in various transcriptional factors (TFs) and TF-associated proteins. The results of our systems investigation now indicate that there is cross-talk involving a broad range of diverse biological pathways/processes that coordinate the host response to M. marinum PPE38.
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Release of luminal exosomes contributes to TLR4-mediated epithelial antimicrobial defense.
PLoS Pathog.
PUBLISHED: 04-01-2013
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Exosomes are membranous nanovesicles released by most cell types from multi-vesicular endosomes. They are speculated to transfer molecules to neighboring or distant cells and modulate many physiological and pathological procedures. Exosomes released from the gastrointestinal epithelium to the basolateral side have been implicated in antigen presentation. Here, we report that luminal release of exosomes from the biliary and intestinal epithelium is increased following infection by the protozoan parasite Cryptosporidium parvum. Release of exosomes involves activation of TLR4/IKK2 signaling through promoting the SNAP23-associated vesicular exocytotic process. Downregulation of let-7 family miRNAs by activation of TLR4 signaling increases SNAP23 expression, coordinating exosome release in response to C. parvum infection. Intriguingly, exosomes carry antimicrobial peptides of epithelial cell origin, including cathelicidin-37 and beta-defensin 2. Activation of TLR4 signaling enhances exosomal shuttle of epithelial antimicrobial peptides. Exposure of C. parvum sporozoites to released exosomes decreases their viability and infectivity both in vitro and ex vivo. Direct binding to the C. parvum sporozoite surface is required for the anti-C. parvum activity of released exosomes. Biliary epithelial cells also increase exosomal release and display exosome-associated anti-C. parvum activity following LPS stimulation. Our data indicate that TLR4 signaling regulates luminal exosome release and shuttling of antimicrobial peptides from the gastrointestinal epithelium, revealing a new arm of mucosal immunity relevant to antimicrobial defense.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.