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Find video protocols related to scientific articles indexed in Pubmed.
[The expression and significance of chemokines eotaxin and RANTES in the rat model of allergic rhinitis].
Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
PUBLISHED: 10-22-2014
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To explore the expression and significance of Eotaxin and RANTES in the rat model of allergic rhinitis (AR).
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[3D computed tomographic analysis of frontal recess region].
Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
PUBLISHED: 09-05-2014
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The purpose of the study was to observe the three-dimensional (3D) CT imaging features of the frontal recess region with 3D reconstruction, and obtain the real image of the important anatomical structures of the region to conduct surgery.
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Genetic variations in two seahorse species (Hippocampus mohnikei and Hippocampus trimaculatus): evidence for middle Pleistocene population expansion.
PLoS ONE
PUBLISHED: 08-21-2014
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Population genetic of seahorses is confidently influenced by their species-specific ecological requirements and life-history traits. In the present study, partial sequences of mitochondrial cytochrome b (cytb) and control region (CR) were obtained from 50 Hippocampus mohnikei and 92 H. trimaculatus from four zoogeographical zones. A total of 780 base pairs of cytb gene were sequenced to characterize mitochondrial DNA (mtDNA) diversity. The mtDNA marker revealed high haplotype diversity, low nucleotide diversity, and a lack of population structure across both populations of H. mohnikei and H. trimaculatus. A neighbour-joining (NJ) tree of cytb gene sequences showed that H. mohnikei haplotypes formed one cluster. A maximum likelihood (ML) tree of cytb gene sequences showed that H. trimaculatus belonged to one lineage. The star-like pattern median-joining network of cytb and CR markers indicated a previous demographic expansion of H. mohnikei and H. trimaculatus. The cytb and CR data sets exhibited a unimodal mismatch distribution, which may have resulted from population expansion. Mismatch analysis suggested that the expansion was initiated about 276,000 years ago for H. mohnikei and about 230,000 years ago for H. trimaculatus during the middle Pleistocene period. This study indicates a possible signature of genetic variation and population expansion in two seahorses under complex marine environments.
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Complete mitochondrial genome sequence of the longsnout seahorse Hippocampus reidi (Ginsburg, 1933; Gasterosteiformes: Syngnathidae).
Mitochondrial DNA
PUBLISHED: 08-18-2014
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Abstract The complete mitochondrial genome sequence of the longsnout seahorse Hippocampus reidi was fisrt determined in this article. The total length of H. reidi mitogenome is 16,529?bp and consists of 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and 1 control region. The gene order and composition of H. reidi were similar to those of most other vertebrates. The overall base composition of H. reidi is 32.47% A, 29.41% T, 14.75% G and 23.37%?C, with a slight A?+?T rich feature (61.88%).
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Arsenic trioxide reactivates proteasome-dependent degradation of mutant p53 protein in cancer cells in part via enhanced expression of Pirh2 E3 ligase.
PLoS ONE
PUBLISHED: 08-12-2014
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The p53 gene is mutated in more than 50% of human tumors. Mutant p53 exerts an oncogenic function and is often highly expressed in cancer cells due to evasion of proteasome-dependent degradation. Thus, reactivating proteasome-dependent degradation of mutant p53 protein is an attractive strategy for cancer management. Previously, we found that arsenic trioxide (ATO), a drug for acute promyelocytic leukemia, degrades mutant p53 protein through a proteasome pathway. However, it remains unclear what is the E3 ligase that targets mutant p53 for degradation. In current study, we sought to identify an E3 ligase necessary for ATO-mediated degradation of mutant p53. We found that ATO induces expression of Pirh2 E3 ligase at the transcriptional level. We also found that knockdown of Pirh2 inhibits, whereas ectopic expression of Pirh2 enhances, ATO-induced degradation of mutant p53 protein. Furthermore, we found that Pirh2 E3 ligase physically interacts with and targets mutant p53 for polyubiquitination and subsequently proteasomal degradation. Interestingly, we found that ATO cooperates with HSP90 or HDAC inhibitor to promote mutant p53 degradation and growth suppression in tumor cells. Together, these data suggest that ATO promotes mutant p53 degradation in part via induction of the Pirh2-dependent proteasome pathway.
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Downregulation of microRNA miR-526a by enterovirus inhibits RIG-I-dependent innate immune response.
J. Virol.
PUBLISHED: 07-23-2014
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Retinoic acid-inducible gene I (RIG-I) is an intracellular RNA virus sensor that induces type I interferon-mediated host-protective innate immunity against viral infection. Although cylindromatosis (CYLD) has been shown to negatively regulate innate antiviral response by removing K-63-linked polyubiquitin from RIG-I, the regulation of its expression and the underlying regulatory mechanisms are still incompletely understood. Here we show that RIG-I activity is regulated by inhibition of CYLD expression mediated by the microRNA miR-526a. We found that viral infection specifically upregulates miR-526a expression in macrophages via interferon regulatory factor (IRF)-dependent mechanisms. In turn, miR-526a positively regulates virus-triggered type I interferon (IFN-I) production, thus suppressing viral replication, the underlying mechanism of which is the enhancement of RIG-I K63-linked ubiquitination by miR-526a via suppression of the expression of CYLD. Remarkably, virus-induced miR-526a upregulation and CYLD downregulation are blocked by enterovirus 71 (EV71) 3C protein, while ectopic miR-526a expression inhibits the replication of EV71 virus. The collective results of this study suggest a novel mechanism of the regulation of RIG-I activity during RNA virus infection by miR-526a and suggest a novel mechanism for the evasion of the innate immune response controlled by EV71.
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Overexpression of Mps1 in colon cancer cells attenuates the spindle assembly checkpoint and increases aneuploidy.
Biochem. Biophys. Res. Commun.
PUBLISHED: 07-09-2014
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The spindle assembly checkpoint kinase Mps1 is highly expressed in several types of cancers, but its cellular involvement in tumorigenesis is less defined. Herein, we confirm that Mps1 is overexpressed in colon cancer tissues. Further, we find that forced expression of Mps1 in the colon cancer cell line SW480 enables cells to become resistant to both Mps1 inhibition-induced checkpoint depletion and cell death. Overexpression of Mps1 also increases genome instability in tumor cells owing to a weakened spindle assembly checkpoint. Collectively, our findings suggest that high levels of Mps1 contribute to tumorigenesis by attenuating the spindle assembly checkpoint.
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Complete mitochondrial genome of the pacific seahorse Hippocampus ingens Girard, 1858 (Gasterosteiformes: Syngnathidae).
Mitochondrial DNA
PUBLISHED: 01-28-2014
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Abstract The complete mitochondrial genome sequence of the pacific seahorse Hippocampus ingens was determined using long polymerase chain reactions. The total length of H. ingens mitogenome is 16,526?bp and consists of 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and a control region. The gene order and composition of H. ingens were similar to those of most other vertebrates. The overall base composition of H. ingens is 32.6% A, 29.3% T, 23.5% G and 14.6% C, with a slight A+T rich feature (61.9%).
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Elevated expression of TANK-binding kinase 1 enhances tamoxifen resistance in breast cancer.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 01-21-2014
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Resistance to antiestrogens is one of the major challenges in breast cancer treatment. Although phosphorylation of estrogen receptor ? (ER?) is an important factor in endocrine resistance, the contributions of specific kinases in endocrine resistance are still not fully understood. Here, we report that an important innate immune response kinase, the I?B kinase-related TANK-binding kinase 1 (TBK1), is a crucial determinant of resistance to tamoxifen therapies. We show that TBK1 increases ER? transcriptional activity through phosphorylation modification of ER? at the Ser-305 site. Ectopic TBK1 expression impairs the responsiveness of breast cancer cells to tamoxifen. By studying the specimens from patients with breast cancer, we find a strong positive correlation of TBK1 with ER?, ER? Ser-305, and cyclin D1. Notably, patients with tumors highly expressing TBK1 respond poorly to tamoxifen treatment and show high potential for relapse. Therefore, our findings suggest that TBK1 contributes to tamoxifen resistance in breast cancer via phosphorylation modification of ER?.
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Complete mitochondrial genome sequence of the Barbour's seahorse Hippocampus barbouri Jordan & Richardson, 1908 (Gasterosteiformes: Syngnathidae).
Mitochondrial DNA
PUBLISHED: 01-14-2014
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Abstract The complete mitochondrial genome sequence of the Barbour's seahorse Hippocampus barbouri was first determined in this paper. The total length of H. barbouri mitogenome is 16,526?bp, which consists of 13 protein-coding genes, 22 tRNA and 2 rRNA genes and 1 control region. The features of the H. barbouri mitochondrial genome were similar to the typical vertebrates. The overall base composition of H. barbouri is 32.68% A, 29.75% T, 22.91% C and 14.66% G, with an AT content of 62.43%.
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Hepatoma SK Hep-1 Cells Exhibit Characteristics of Oncogenic Mesenchymal Stem Cells with Highly Metastatic Capacity.
PLoS ONE
PUBLISHED: 01-01-2014
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SK Hep-1 cells (SK cells) derived from a patient with liver adenocarcinoma have been considered a human hepatoma cell line with mesenchymal origin characteristics, however, SK cells do not express liver genes and exhibit liver function, thus, we hypothesized whether mesenchymal cells might contribute to human liver primary cancers. Here, we characterized SK cells and its tumourigenicity.
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Vagus nerve stimulation attenuates cerebral ischemia and reperfusion injury via endogenous cholinergic pathway in rat.
PLoS ONE
PUBLISHED: 01-01-2014
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Inflammation and apoptosis play critical roles in the acute progression of ischemic injury pathology. Emerging evidence indicates that vagus nerve stimulation (VNS) following focal cerebral ischemia and reperfusion (I/R) may be neuroprotective by limiting infarct size. However, the underlying molecular mechanisms remain unclear. In this study, we investigated whether the protective effects of VNS in acute cerebral I/R injury were associated with anti-inflammatory and anti-apoptotic processes. Male Sprague-Dawley (SD) rats underwent VNS at 30 min after focal cerebral I/R surgery. Twenty-four h after reperfusion, neurological deficit scores, infarct volume, and neuronal apoptosis were evaluated. In addition, the levels of pro-inflammatory cytokines were detected using enzyme-linked immune sorbent assay (ELISA), and immunofluorescence staining for the endogenous "cholinergic anti-inflammatory pathway" was also performed. The protein expression of a7 nicotinic acetylcholine receptor (a7nAchR), phosphorylated Akt (p-Akt), and cleaved caspase 3 in ischemic penumbra were determined with Western blot analysis. I/R rats treated with VNS (I/R+VNS) had significantly better neurological deficit scores, reduced cerebral infarct volume, and decreased number of TdT mediated dUTP nick end labeling (TUNEL) positive cells. Furthermore, in the ischemic penumbra of the I/R+VNS group, the levels of pro-inflammatory cytokines and cleaved caspase 3 protein were significantly decreased, and the levels of a7nAchR and phosphorylated Akt were significantly increased relative to the I/R alone group. These results indicate that VNS is neuroprotective in acute cerebral I/R injury by suppressing inflammation and apoptosis via activation of cholinergic and a7nAchR/Akt pathways.
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LPS-induced inflammation in the chicken is associated with CCAAT/enhancer binding protein beta-mediated fat mass and obesity associated gene down-regulation in the liver but not hypothalamus.
BMC Vet. Res.
PUBLISHED: 11-01-2013
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The fat mass and obesity associated gene (FTO) is widely investigated in humans regarding its important roles in obesity and type 2 diabetes. Studies in mammals demonstrate that FTO is also associated with inflammation markers. However, the association of FTO with inflammation in chickens remains unclear. In this study, male chickens on day 28 posthatching were injected intraperitoneally with lipopolysaccharide (LPS) or saline to investigate whether the FTO gene is involved in LPS-induced inflammation.
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Complete mitochondrial genome sequence of the lined seahorse Hippocampus erectus Perry, 1810 (Gasterosteiformes: Syngnathidae).
Mitochondrial DNA
PUBLISHED: 10-10-2013
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Abstract The complete mitochondrial genome sequence of the lined seahorse Hippocampus erectus was first determined in this article. The total length of H. erectus mitogenome is 16,529?bp, which consists of 13 protein-coding genes, 22 tRNA and 2 rRNA genes and 1 control region. The features of the H. erectus mitochondrial genome were similar to the typical vertebrates. The overall base composition of H. erectus is 31.8% A, 28.6% T, 24.3% C and 15.3% G, with a slight A?+?T rich feature (60.4%).
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Enhanced reactivity of graphene wrinkles and their function as nanosized gas inlets for reactions under graphene.
Phys Chem Chem Phys
PUBLISHED: 10-08-2013
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Formation of wrinkles at graphene/Pt(111) surface was investigated by low energy electron microscopy (LEEM). Reversible wrinkling and unwrinkling of graphene sheets were observed upon cycled heating and cooling treatments, exhibiting a hysteresis effect with the temperature. In situ LEEM studies of graphene oxidation show preferential oxidation of the wrinkles than flat graphene sheets and graphene edges. The function of the wrinkles as one-dimensional (1D) nanosized gas inlets for oxygen and the strain at the distorted sp(2)-hybridized carbon atoms of the wrinkle sites can be attributed to the enhanced reactivity of wrinkles to the oxidation. Meanwhile, wrinkles also served as nanosized gas inlets for oxidation of CO intercalated between graphene and Pt(111). Considering that wrinkles are frequently present in graphene structures, the role of wrinkles as 1D reaction channels and their enhanced reactivity to reactions may have an important effect on graphene chemistry.
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Breed-dependent transcriptional regulation of phosphoenolpyruvate carboxylase, cytosolic form, expression in the liver of broiler chickens.
Poult. Sci.
PUBLISHED: 09-19-2013
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Hepatic gluconeogenesis is the main source of glucose during chicken embryonic development, and it plays a major role in glucose homeostasis for developing embryos. Phosphoenolpyruvate carboxylase (PEPCK) catalyzes the rate-limiting step of gluconeogenesis, yet how hepatic PEPCK expression is differentially regulated between chicken breeds remains elusive. In this study, fertile eggs from a slow-growing Chinese Yellow Feathered Chicken and a fast-growing White Recessive Rock Chicken were incubated under the same standard conditions, and serum and liver samples were collected on embryonic d 18 (18E). The fast-growing breed had a significantly higher fetal weight (P < 0.01) and serum glucose concentration (P < 0.05) compared with the slow-growing breed. The fast-growing breed also had significantly higher hepatic mRNA expression levels of the cystolic form of PEPCK (PEPCK-c; P < 0.05) and significantly higher hepatic mRNA and protein expression levels of cAMP response element binding protein 1 (CREB-1; P < 0.05). Moreover, the binding of phosphorylated CREB-1 to the PEPCK-c promoter tended to be higher in the fast-growing breed (P = 0.08). Breed-specific epigenetic modifications of the PEPCK-c promoter were also observed; the fast-growing breed demonstrated lower CpG methylation (P < 0.05) and histone H3 (P < 0.05) levels but more histone H3 acetylation (H3ac) and histone H3 lysine 27 trimethylation (H3K27me3; P < 0.05) compared with the slow-growing breed. Our results suggest that hepatic PEPCK-c expression is transcriptionally regulated in a breed-specific manner and that fast- and slow-growing broiler chicken fetuses exhibit different epigenetic modifications on their PEPCK-c promoter regions.
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Diagnosis of systemic amyloidosis and amyloidosis mediated cardiomyopathy by VATS pleural biopsy for chronic pleural effusion.
J Thorac Dis
PUBLISHED: 07-05-2013
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Amyloidosis is a family of diseases characterized by the extracellular accumulation of amyloid protein, causing altered physiology based on its abnormal deposition in an organ. The etiology of persistent pleural effusions in patients with systemic amyloidosis is unknown. Endomyocardial biopsy is the gold standard of diagnosis for patients with cardiac involvement in systemic amyloidosis. We present the case of a patient with systemic amyloidosis whose diagnosis was made by pleural pathology collected via video-assisted thoracic surgery after a false negative endomyocardial biopsy.
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MAVS regulates apoptotic cell death by decreasing K48-linked ubiquitination of voltage-dependent anion channel 1.
Mol. Cell. Biol.
PUBLISHED: 06-10-2013
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The mitochondrial antiviral signaling protein MAVS (IPS-1, VISA, or Cardif) plays an important role in the host defense against viral infection by inducing type I interferon. Recent reports have shown that MAVS is also critical for virus-induced apoptosis. However, the mechanism of MAVS-mediated apoptosis induction remains unclear. Here, we show that MAVS binds to voltage-dependent anion channel 1 (VDAC1) and induces apoptosis by caspase-3 activation, which is independent of its role in innate immunity. MAVS modulates VDAC1 protein stability by decreasing its degradative K48-linked ubiquitination. In addition, MAVS knockout mouse embryonic fibroblasts (MEFs) display reduced VDAC1 expression with a consequent reduction of the vesicular stomatitis virus (VSV)-induced apoptosis response. Notably, the upregulation of VDAC1 triggered by VSV infection is completely abolished in MAVS knockout MEFs. We thus identify VDAC1 as a target of MAVS and describe a novel mechanism of MAVS control of virus-induced apoptotic cell death.
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Expression, purification and characterization of a recombinant Tat47-57-Oct4 fusion protein in Pichia pastoris.
Mol Med Rep
PUBLISHED: 05-22-2013
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The transcription factor, Oct-4, is involved in the self-renewal of undifferentiated embryonic stem cells, and is also significant in the reprogramming process and in the development of tumors. In the present study, the fusion protein, Tat47?57-Oct4, was secreted by the signal peptide of human serum albumin in Pichia pastoris under the control of alcohol oxidase promoter 1. The yield of recombinant Tat47?57-Oct4 fusion protein was ~210 mg/l. Following pilot?scale fermentation, Tat47?57-Oct4 was purified by ammonium sulfate precipitation, Vivaflow 200 ultrafiltration and SP Sepharose fast flow chromatography in order to obtain 95.6% purity. Immunofluorescence analysis validated the ability of Tat47?57-Oct4 to cross the cell membrane. The results demonstrated that the experimental procedure developed in the present study could produce large quantities of active Tat47?57-Oct4 fusion protein from P. pastoris.
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Ubiquitin-like domain of IKK? regulates osteoclastogenesis and osteolysis.
Calcif. Tissue Int.
PUBLISHED: 04-19-2013
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The transcription factor NF-?B family is central for osteoclastogenesis and inflammatory osteolysis. Activation of NF-?B dimers is regulated by a kinase complex predominantly containing IKK? (IKK1), IKK? (IKK2), and a regulatory subunit, IKK?/NEMO. IKK? and IKK? catalyze the cytoplasmic liberation and nuclear translocation of various NF-?B subunits. The requirement of IKK? and IKK? for normal bone homeostasis has been established. Congruently, mice devoid of IKK? or IKK? exhibit in vitro and in vivo defects in osteoclastogenesis, and IKK?-null mice are refractory to inflammatory arthritis and osteolysis. To better understand the molecular mechanism underlying IKK? function in bone homeostasis and bone pathologies, we conducted structure-function analysis to determine IKK? functional domains in osteoclasts. IKK? encompasses several domains, of which the ubiquitination-like domain (ULD) has been shown essential for IKK? activation. In this study, we examined the role of ULD in IKK?-mediated NF-?B activation in osteoclast precursors and its contribution to osteoclastogenesis and osteolysis. We generated and virally introduced IKK? in which the ULD domain has been deleted (IKK??ULD) into osteoclast progenitors. The results show that deletion of ULD diminishes IKK? activity and that IKK??ULD strongly inhibits osteoclastogenesis. In addition, unlike wild type (WT)-IKK?, IKK??ULD fail to restore RANKL-induced osteoclastogenesis by IKK?-null precursors. Finally, we provide evidence that IKK??ULD blocks inflammatory osteolysis in a model of murine calvarial osteolysis. Thus, we identified the ULD as crucial for IKK? activity and osteoclastogenesis and found that ULD-deficient IKK? is a potent inhibitor of osteoclastogenesis and osteolysis.
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UV-C irradiation delays mitotic progression by recruiting Mps1 to kinetochores.
Cell Cycle
PUBLISHED: 03-26-2013
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The effect of UV irradiation on replicating cells during interphase has been studied extensively. However, how the mitotic cell responds to UV irradiation is less well defined. Herein, we found that UV-C irradiation (254 nm) increases recruitment of the spindle checkpoint proteins Mps1 and Mad2 to the kinetochore during metaphase, suggesting that the spindle assembly checkpoint (SAC) is reactivated. In accordance with this, cells exposed to UV-C showed delayed mitotic progression, characterized by a prolonged chromosomal alignment during metaphase. UV-C irradiation also induced the DNA damage response and caused a significant accumulation of ?-H2AX on mitotic chromosomes. Unexpectedly, the mitotic delay upon UV-C irradiation is not due to the DNA damage response but to the relocation of Mps1 to the kinetochore. Further, we found that UV-C irradiation activates Aurora B kinase. Importantly, the kinase activity of Aurora B is indispensable for full recruitment of Mps1 to the kinetochore during both prometaphase and metaphase. Taking these findings together, we propose that UV irradiation delays mitotic progression by evoking the Aurora B-Mps1 signaling cascade, which exerts its role through promoting the association of Mps1 with the kinetochore in metaphase.
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Nalp3 inflammasome is activated and required for vascular smooth muscle cell calcification.
Int. J. Cardiol.
PUBLISHED: 01-18-2013
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The calcification of blood vessels correlates with increased morbidity and mortality in patients with atherosclerosis, diabetes, and end-stage kidney disease. Increased inflammasome activation has been shown to play an important role in the pathogenesis of atherosclerosis. However, the contribution of inflammasome activation on the development of vascular calcification has not been investigated.
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Genes involved in fatty acid metabolism: molecular characterization and hypothalamic mRNA response to energy status and neuropeptide Y treatment in the orange-spotted grouper Epinephelus coioides.
Mol. Cell. Endocrinol.
PUBLISHED: 01-15-2013
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As in mammals, fatty acid (FA) metabolism plays diverse and vital roles in regulating food intake in fish. Multiple lines of evidence suggest that the effect of FA metabolism on food intake is linked to changes in the level of neuropeptide Y (NPY) in the hypothalamus of the rainbow trout. In mammals, the evidence suggests that FA metabolism regulates feeding via hypothalamic NPY. NPY is therefore considered an important factor that mediates the modulation of food intake by FA metabolism in vertebrates. The stimulatory effect of NPY on food intake is well known. However, to the best of our knowledge, the effect of NPY on FA metabolism in the hypothalamus has not been examined. In this study, we cloned the cDNA of four key enzymes involved in FA metabolism and assessed the effect of energy status and NPY on their mRNA expression in the hypothalamus of grouper. The full-length cDNAs of UCP2 and CPT1a and the partial coding sequence (CDS) of ACC1 and FAS were isolated from the grouper hypothalamus. These genes are expressed in the hypothalamus and during the organogenetic stage of embryogenesis. A feeding rhythm study showed that the hypothalamic expression level of NPY and CPT1a was highly correlated with feeding rhythm. Long-term fasting was found to significantly induce the hypothalamic mRNA expression of NPY, CPT1a and UCP2. An in vitro study demonstrated that NPY strongly stimulated CPT1a and UCP2 mRNA expression in a time- and dose-dependent manner. Collectively, these results suggest that these four genes related to FA metabolism may play a role in regulating food intake in grouper and, that NPY modulates FA metabolism in the grouper hypothalamus. This study showed, for the first time in vertebrates, the effect of NPY on the gene expression of FA metabolism-related enzymes.
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Mutant p53 Cooperates with Knockdown of Endogenous Wild-Type p53 to Disrupt Tubulogenesis in Madin-Darby Canine Kidney Cells.
PLoS ONE
PUBLISHED: 01-01-2013
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Mutation of the p53 gene is the most common genetic alteration in human malignances and associated clinically with tumor progression and metastasis. To determine the effect of mutant p53 on epithelial differentiation, we developed three-dimensional culture (3-D) of Madin-Darby canine kidney (MDCK) cells. We found that parental MDCK cells undergo a series of morphological changes and form polarized and growth-arrested cysts with hollow lumen, which resembles branching tubules in vitro. We also found that upon knockdown of endogenous wild-type p53 (p53-KD), MDCK cells still form normal cysts in 3-D culture, indicating that p53-KD alone is not sufficient to disrupt cysts formation. However, we found that ectopic expression of mutant R163H (human equivalent R175H) or R261H (human equivalent R273H) in MDCK cells leads to disruption of cyst polarity and formation of invasive aggregates, which is further compounded by knockdown of endogenous wild-type p53. Consistently, we found that expression of E-cadherin, ?-catenin, and epithelial-to-mesenchymal transition (EMT) transcription factors (Snail-1, Slug and Twist) is altered by mutant p53, which is also compounded by knockdown of wild-type p53. Moreover, the expression level of c-Met, the hepatocyte growth factor receptor and a key regulator of kidney cell tubulogenesis, is enhanced by combined knockdown of endogenous wild-type p53 and ectopic expression of mutant R163H or R261H but not by each individually. Together, our data suggest that upon inactivating mutation of the p53 gene, mutant p53 acquires its gain of function by altering morphogenesis and promoting cell migration and invasion in part by upregulating EMT and c-Met.
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PUMA Cooperates with p21 to Regulate Mammary Epithelial Morphogenesis and Epithelial-To-Mesenchymal Transition.
PLoS ONE
PUBLISHED: 01-01-2013
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Lumen formation is essential for mammary morphogenesis and requires proliferative suppression and apoptotic clearance of the inner cells within developing acini. Previously, we showed that knockdown of p53 or p73 leads to aberrant mammary acinus formation accompanied with decreased expression of p53 family targets PUMA and p21, suggesting that PUMA, an inducer of apoptosis, and p21, an inducer of cell cycle arrest, directly regulate mammary morphogenesis. To address this, we generated multiple MCF10A cell lines in which PUMA, p21, or both were stably knocked down. We found that morphogenesis of MCF10A cells was altered modestly by knockdown of either PUMA or p21 alone but markedly by knockdown of both PUMA and p21. Moreover, we found that knockdown of PUMA and p21 leads to loss of E-cadherin expression along with increased expression of epithelial-to-mesenchymal transition (EMT) markers. Interestingly, we found that knockdown of ?Np73, which antagonizes the ability of wide-type p53 and TA isoform of p73 to regulate PUMA and p21, mitigates the abnormal morphogenesis and EMT induced by knockdown of PUMA or p21. Together, our data suggest that PUMA cooperates with p21 to regulate normal acinus formation and EMT.
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Metaplastic breast carcinomas are enriched in markers of tumor-initiating cells and epithelial to mesenchymal transition.
Mod. Pathol.
PUBLISHED: 11-11-2011
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Metaplastic breast carcinomas constitute a distinct aggressive form of invasive breast cancer with histological evidence of epithelial to mesenchymal transition toward spindle, chondroid, or osseous cell types. During tumorigenesis, epithelial to mesenchymal transition promotes invasion and metastasis and has been linked to the presence of stem cells. We hypothesized that metaplastic carcinomas may express epithelial to mesenchymal transition markers and may be enriched in tumor-initiating cells specifically in the non-glandular metaplastic elements. In 27 primary metaplastic carcinomas of the breast we tested the expression of epithelial to mesenchymal transition inducers ZEB1 and E-cadherin and the presence of tumor-initiating cells by using aldehyde dehydrogenase-1 (ALDH-1) and CD44(+)/CD24(-/low) immunohistochemistry. Of the 27 metaplastic carcinomas, 20 (74%) had squamous and/or spindle areas and 7 (26%) had heterologous elements (6 chondroid and 1 osseous). ALDH-1-positive and CD44(+)/CD24(-/low)-expressing cells were detected in the non-glandular metaplastic components (Fishers exact, P=0.0017). E-cadherin expression was reduced or absent (aberrant) in all metaplastic components whereas it was normal in the glandular areas. On the contrary, overexpression of ZEB1 was detected in 41% (11 of 27) of the non-glandular, metaplastic components, and in none of the glandular areas. The presence of tumor-initiating cells, aberrant E-cadherin, and ZEB1 upregulation was associated in over 90% of the spindle areas and heterologous elements (?(2) test, P<0.05). We provide first in situ evidence that epithelial to mesenchymal transition inducers and tumor-initiating cells are present specifically in the non-glandular components of metaplastic carcinomas.
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Two LXXLL motifs in the N terminus of Mps1 are required for Mps1 nuclear import during G(2)/M transition and sustained spindle checkpoint responses.
Cell Cycle
PUBLISHED: 08-15-2011
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Spindle assembly checkpoint kinase Mps1 is spatially and temporally regulated during cell cycle progression. Mps1 is predominately localized to the cytosol in interphase cells, whereas it is concentrated on kinetochores in prophase and prometaphase cells. The timing and mechanism of Mps1 redistribution during cell cycle transition is currently poorly understood. Here, we show that Mps1 relocates from the cytosol to the nucleus at the G 2/M boundary prior to nuclear envelope breakdown (NEB). This timely translocation depends on two tandem LXXLL motifs in the N terminus of Mps1, and mutations in either motif abolish Mps1 nuclear accumulation. Furthermore, we found that phosphorylation of Mps1 Ser80 (which is located between the two LXXLL motifs) also plays a role in regulating timely nuclear entry of Mps1. Mps1 that is defective in LXXLL motifs has near wild-type kinase activity. Moreover, the kinase activity of Mps1 appears to be dispensable for nuclear translocation, as inhibition of Mps1 by a highly specific small-molecule inhibitor did not perturb its nuclear entry. Remarkably, translocation-deficient Mps1 can mediate activation of spindle assembly checkpoint response; however, it fails to support a sustained mitotic arrest upon prolonged treatment with nocodazole. The mitotic slippage can be attributed to precocious degradation of Mps1 in the arrested cells. Our studies reveal a novel cell cycle-dependent nuclear translocation signal in the N terminus of Mps1 and suggest that timely nuclear entry could be important for sustaining spindle assembly checkpoint responses.
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Mutant p53 protein is targeted by arsenic for degradation and plays a role in arsenic-mediated growth suppression.
J. Biol. Chem.
PUBLISHED: 03-29-2011
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p53 is frequently mutated in tumor cells, and mutant p53 is often highly expressed due to its increased half-life. Thus, targeting mutant p53 for degradation might be explored as a therapeutic strategy to manage tumors that are addicted to mutant p53 for survival. Arsenic trioxide, a drug for patients with acute promyelocytic leukemia, is found to target and degrade a class of proteins with high levels of cysteine residues and vicinal thiol groups, such as promyelocytic leukemia protein (PML) and PML-retinoic acid receptor ? fusion protein. Interestingly, wild type p53 is accumulated in cells treated with arsenic compounds, presumably due to arsenic-induced oxidative stresses. In this study, we found that wild type p53 is induced by arsenic trioxide in tumor cells, consistent with published studies. In contrast, we found that arsenic compounds degrade both endogenous and ectopically expressed mutant p53 in time- and dose-dependent manners. We also found that arsenic trioxide decreases the stability of mutant p53 protein through a proteasomal pathway, and blockage of mutant p53 nuclear export can alleviate the arsenic-induced mutant p53 degradation. Furthermore, we found that knockdown of endogenous mutant p53 sensitizes, whereas ectopic expression of mutant p53 desensitizes, tumor cells to arsenic treatment. Taken together, we found that mutant p53 is a target of arsenic compounds, which provides an insight into exploring arsenic compound-based therapy for tumors harboring a mutant p53.
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Orange-spotted grouper (Epinephelus coioides) orexin: molecular cloning, tissue expression, ontogeny, daily rhythm and regulation of NPY gene expression.
Peptides
PUBLISHED: 03-26-2011
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Orexin-A and -B, collectively called orexins, are hypothalamic neuropeptides involved in the regulation of food intake, sleep and energy balance. In this study, the full-length cDNA of prepro-orexin was isolated from the hypothalamus of orange-spotted grouper (Epinephelus coioides) using RT-PCR and RACE. The grouper prepro-orexin cDNA is 711 bp in length and encodes a 149-amino acid precursor protein that contains a 46-amino acid signal peptide, a 43-amino acid mature orexin-A peptide, a 27-amino acid mature orexin-B peptide and a 33-amino acid C terminus of unknown function. The tissue distribution and ontogeny of prepro-orexin were examined by quantitative real-time PCR. We found that the prepro-orexin mRNA is widely expressed in brain and peripheral tissues, with abundant expression in the hypothalamus. During the embryonic development, prepro-orexin mRNA was first detected in neurula stage embryos, and its expression gradually increased during the remainder of embryogenesis. Our analysis of grouper hypothalamic prepro-orexin expression showed that prepro-orexin mRNA levels were greater in the light phase than in the dark phase and increased significantly at meal-time. Intraperitoneal injection of orexin-A caused a dose-related increase in hypothalamus NPY mRNA expression level after 4h. Orexin-A also increased NPY mRNA expression level from static hypothalamic fragments incubation. Our results imply that orexin may be involved in feeding in the orange-spotted grouper and orexin-A is a stimulator of NPY mRNA expression in vivo and in vitro.
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Mutant p53 disrupts MCF-10A cell polarity in three-dimensional culture via epithelial-to-mesenchymal transitions.
J. Biol. Chem.
PUBLISHED: 03-22-2011
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Mutant p53 is not only deficient in tumor suppression but also acquires additional activity, called gain of function. Mutant p53 gain of function is recapitulated in knock-in mice that carry one null allele and one mutant allele of the p53 gene. These knock-in mice develop aggressive tumors compared with p53-null mice. Recently, we and others showed that tumor cells carrying a mutant p53 are addicted to the mutant for cell survival and resistance to DNA damage. To further define mutant p53 gain of function, we used the MCF-10A three-dimensional model of mammary morphogenesis. MCF-10A cells in three-dimensional culture undergo a series of morphological changes and form polarized and growth-arrested spheroids with hollow lumen, which resembles normal glandular architectures in vivo. Here, we found that endogenous wild-type p53 in MCF-10A cells was not required for acinus formation, but knockdown of endogenous wild-type p53 (p53-KD) led to partial clearance of cells in the lumen due to decreased apoptosis. Consistent with this, p53-KD altered expression patterns of the cell adhesion molecule E-cadherin, the cytoskeletal marker ?-catenin, and the extracellular matrix protein laminin V. We also found that ectopic expression of the mutant G245S led to a phenotype similar to p53-KD, whereas a combination of ectopic expression of siRNA-resistant G245S with p53-KD led to a less cleared lumen. In contrast, ectopic expression of mutant R248W, R175H, and R273H disrupted normal acinus architectures with filled lumen and led to formation of irregular and multiacinus structures regardless of p53-KD. In addition, these mutants altered normal expression patterns and/or levels of E-cadherin, ?-catenin, laminin V, and tight junction marker ZO-1. Furthermore, epithelial-to-mesenchymal transitions (EMT) markers, Snail, Slug, and Twist, were highly induced by mutant p53 and/or p53-KD. Together, we postulate that EMT represents a mutant p53 gain of function and mutant p53 alters cell polarity via EMT.
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Thinking and practice of accelerating transformation of traditional Chinese medicine from experience medicine to evidence-based medicine.
Front Med
PUBLISHED: 03-10-2011
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The gradual development of Chinese medicine is based on constant accumulation and summary of experience in clinical practice, but without the benefit of undergoing the experimental medicine stage. Although Chinese medicine has formed a systematic and unique theory system through thousands of years, with the development of evidence-based medicine, the bondage of the research methods of experience medicine to Chinese medicine is appearing. The rapid transition and transformation from experience medicine to evidence-based medicine have become important content in the development of Chinese medicine. According to the features of Chinese medicine, we propose the research idea of "taking two ways simultaneously," which is the study both in the ideal condition and in the real world. Analyzing and constructing the theoretical basis and methodology of clinical research in the real world, and building the stage for research technique is key to the effective clinical research of Chinese medicine. Only by gradually maturing and completing the clinical research methods of the real world could we realize "taking two ways simultaneously" and complementing each other, continuously produce scientific and reliable evidence of Chinese medicine, as well as transform and develop Chinese medicine from experience medicine to evidence-based medicine.
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Reversible self-assembly of dendrimer based on polyhedral oligomeric silsesquioxanes (POSS).
Chem. Commun. (Camb.)
PUBLISHED: 11-22-2010
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An acid-base switchable dendritic complex was constructed by self-assembly between dibenzo-24-crown-8 terminated T(10)-POSS dendrimer and dibenzylammonium hexafluorophosphate salt based on T(8)-POSS. The formation and its threading-dethreading property were characterized by (1)H NMR and UV-visible absorption spectroscopy.
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G Protein-Coupled Receptor 87: a Promising Opportunity for Cancer Drug Discovery.
Mol Cell Pharmacol
PUBLISHED: 08-06-2010
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G protein-coupled receptors (GPRs) constitute one of the largest families of membrane proteins encoded by the human genome. Upon binding to various ligands, these seven-transmembrane receptors play an essential role in many physiological processes, including neurotransmission, immunity, inflammation, regulation of mood and behavior. In view of their important functions, aberrant expression and activity of GPRs have been implicated in a wide spectrum of diseases, including tumorigenesis. GPR87, a cell surface GPR related to the LPA receptor family, is overexpressed in diverse carcinomas and plays an essential role in tumor cell survival. In our recent work, we uncovered that GPR87 expression is regulated by the tumor suppressor p53 and by DNA damage in a p53-dependent manner. Moreover, we found that a lack of GPR87 triggers an increase in p53, concomitant with a decrease in Akt, which results in the sensitization of tumor cells to DNA damage-induced apoptosis and growth suppression. Altogether, we uncovered an essential function for GPR87 in p53-dependent cell survival in response to stress signals. Due to their unique structure, localization and ligand binding ability, GPRs have been extensively used for drug development and are the most common targets of commercial drugs. Although studies are required to determine GPR87 natural ligand(s) and signaling pathways, GPR87 is undoubtedly a very promising novel target for cancer prevention and treatment.
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Expression, purification, and refolding of a recombinant human bone morphogenetic protein 2 in vitro.
Protein Expr. Purif.
PUBLISHED: 07-08-2010
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In this work, the recombinant human bone morphogenetic protein 2 (rhBMP-2) gene was cloned from MG-63 cells by RT-PCR, and the protein was expressed in Escherichia coli expression system, purified by Ni-NTA column under denaturing conditions and refolded at 4°C by urea gradient dialysis. We found that the protein refolding yield was increased with the increase of pH value from pH 6.0 to pH 9.0. The yield was 42% and 96% at pH 7.4 and pH 9.0, respectively, while that at pH 6.0 was only 3.4%. The cell culture results showed that the rhBMP-2 refolded at pH 7.4 urea gradient dialysis had higher biological activity for MG-63 cell proliferation and differentiation than that refolded at pH 9.0 since pH 7.4 is closer to the conditions in vivo leading to the formation of dimers through the interchain disulfide bond. Moreover, the biological activity for MG-63 was promoted with the increase of rhBMP-2 concentration in the cell culture medium. This work may be important for the in vitro production and biomedical application of rhBMP-2 protein.
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The hepatitis B virus X protein disrupts innate immunity by downregulating mitochondrial antiviral signaling protein.
J. Immunol.
PUBLISHED: 06-16-2010
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Previous studies have shown that both hepatitis A virus and hepatitis C virus inhibit innate immunity by cleaving the mitochondrial antiviral signaling (MAVS) protein, an essential component of the virus-activated signaling pathway that activates NF-kappaB and IFN regulatory factor-3 to induce the production of type I IFN. For human hepatitis B virus (HBV), hepatitis B s-Ag, hepatitis B e-Ag, or HBV virions have been shown to suppress TLR-induced antiviral activity with reduced IFN-beta production and subsequent induction of IFN-stimulated genes. However, HBV-mediated suppression of the RIG-I-MDA5 pathway is unknown. In this study, we found that HBV suppressed poly(deoxyadenylate-thymidylate)-activated IFN-beta production in hepatocytes. Specifically, hepatitis B virus X (HBX) interacted with MAVS and promoted the degradation of MAVS through Lys(136) ubiquitin in MAVS protein, thus preventing the induction of IFN-beta. Further analysis of clinical samples revealed that MAVS protein was downregulated in hepatocellular carcinomas of HBV origin, which correlated with increased sensitivities of primary murine hepatocytes isolated from HBX knock-in transgenic mice upon vesicular stomatitis virus infections. By establishing a link between MAVS and HBX, this study suggests that HBV can target the RIG-I signaling by HBX-mediated MAVS downregulation, thereby attenuating the antiviral response of the innate immune system.
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[Design and activity analysis of chimeric epidermal growth factor fusion vaccine E5T-mSEA].
Sheng Wu Gong Cheng Xue Bao
PUBLISHED: 06-04-2010
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Epidermal growth factor receptor (EGFR) and its ligands (EGF and TGFalpha) are over-expressed in a variety of tumors. Immunization EGF-carrier protein inhibits tumor growth through abrogating binding of EGF to EGFR. Here, a chimeric protein of EGF and TGFalpha (E5T) was genetically fused to Staphylococcal enterotoxin A (SEA), a bacterial superantigenic protein which promotes humoral B cell response through enhancement of Ag-specific CD4 T cells activity. The resulted fusion proteins were expressed in Escherichia coli and purified though metal chelating affinity chromatography. Immunization of E5T-mSEA fusion protein in mice induced production of high titers antibodies, which recognize both EGF and TGFalpha. Anti- E5T-mSEA serum at dilution of 1:10 significantly inhibited growth of A431 cell lines but had little effect on 293T cell lines.
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Inhibition of HBV replication by theophylline.
Antiviral Res.
PUBLISHED: 04-19-2010
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We have suggested recently that ATM-Rad3-Related (ATR) DNA damage signaling pathway, which responds to single-strand breaks in DNA, was activated in response to HBV infection. ATR knockdown cells showed decreased HBV DNA yields, implying HBV infection and replication activate and exploit the activated DNA damage response. Host cell proteins may constitute an attractive target for anti-HBV-1 therapeutics, since development of drug resistance against compounds targeting these cellular cofactor proteins is unlikely. In this study, we show that one of the clinically used compounds of ATR and ataxia telangiectasia-mutated (ATM) kinases inhibitor, theophylline (Tp), significantly reduced the yield of HBV DNA, HBsAg and HBeAg in HepG2215 cell culture system, furthermore, Tp could also suppress serum HBV DNA and HBsAg levels in the HBV-transgenic mice. Consistent with this result, immunohistology also showed reduced intensity of HBsAg staining on livers from Tp-treatment group. Taken together, these data indicated the feasibility of therapeutic approaches that target host cell proteins by inhibiting a cellular gene that was required for HBV replication and provided a potential approach for the prevention and treatment of HBV infection.
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[Expression and optimization of anti-AFB1 scFv in Escherichia colil].
Wei Sheng Wu Xue Bao
PUBLISHED: 10-31-2009
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A drawback of the expression of single chain antibody fragment (scFv) in prokaryotic system is the protein accumulation in the cytoplasm as inclusion body. We aimed at high-level production of an anti-aflatoxin B1 scFv in functional form.
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The occurrence and concentration of mycotoxins in U.S. distillers dried grains with solubles.
J. Agric. Food Chem.
PUBLISHED: 10-02-2009
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To provide a scientific sound assessment of the prevalence and levels of mycotoxins in U.S. distillers dried grains with solubles (DDGS), we measured mainly aflatoxins, deoxynivalenol, fumonisins, T-2 toxin, and zearalenone in 235 DDGS samples collected from 20 ethanol plants in the midwestern United States and 23 export shipping containers from 2006 to 2008 using state-of-the-art analytical methodologies. The results suggested that (1) none of the samples contained aflatoxins or deoxynivalenol levels higher than the U.S. Food and Drug Administration (FDA) guidelines for use in animal feed; (2) no more than 10% of the samples contained fumonisin levels higher than the recommendation for feeding equids and rabbits, and the rest of the samples contained fumonisins lower than FDA guidelines for use in animal feed; (3) none of the samples contained T-2 toxins higher than the detection limit, and no FDA guidance levels are available for T-2 toxins; (4) most samples contained zearalenone levels lower than the detection limit, and no FDA guidance levels are available for zearalenone; and (5) the containers used for export shipping of DDGS did not seem to contribute to mycotoxin production. This study was based on representative DDGS samples from the U.S. ethanol industry, and the data were collected using reference methods. This study provided a comprehensive and scientifically sound assessment of the occurrence and levels of mycotoxins in DDGS from the U.S. ethanol industry.
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Negative regulation of MAVS-mediated innate immune response by PSMA7.
J. Immunol.
PUBLISHED: 09-04-2009
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Innate immunity to viruses involves receptors such as Retinoic Acid Induced Gene-1 (RIG-I), which senses viral RNA and triggers a signaling pathway involving the outer mitochondrial membrane protein mitochondrial antiviral signaling (MAVS). Recent work has identified that NLRX1, a member of another class of innate immune receptors, sequesters MAVS away from RIG-I and thereby prevents mitochondrial antiviral immunity. In this study, we demonstrate that the proteasome PSMA7 (alpha4) subunit associates with MAVS in vivo and in vitro. Expression of PSMA7 results in a potent inhibition of RIG-1 and MAVS-mediated IFN-beta promoter activity; conversely, depletion of PSMA7 with small interference RNA enhances virus-induced type I IFN production, with consequent reduction of virus replication. Furthermore, a striking reduction in the abundance of endogenous MAVS with overexpressed PSMA7 was found and virus infection leads to transient increase in the endogenous PSMA7 protein level. Cumulatively, these results suggest that PSMA7 is a negative regulator of the MAVS-mediated innate immunity that probably serves to attenuate the establishment of an antiviral state during viral infection, highlighting the biological significance of PSMA7-MAVS association as an important cellular regulatory control.
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[Phylogenetic analysis of symbiotic archaea in the gut of Reticulitermes chinensis Snyder].
Wei Sheng Wu Xue Bao
PUBLISHED: 07-27-2009
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To analyze the phylotypes of symbiotic archaea in the gut of Reticulitermes chinensis Snyder by using non-cultivating method.
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Reaction between nitric oxide, glutathione, and oxygen in the presence and absence of protein: How are S-nitrosothiols formed?
Free Radic. Biol. Med.
PUBLISHED: 07-20-2009
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The reaction between NO, thiols, and oxygen has been studied in some detail in vitro due to its perceived importance in the mechanism of NO-dependent signal transduction. The formation of S-nitrosothiols and thiol disulfides from this chemistry has been suggested to be an important component of the biological chemistry of NO, and such subsequent thiol modifications may result in changes in cellular function and phenotype. In this study we have reinvestigated this reaction using both experiment and simulation and conclude that: (i) S-nitrosation through radical and nonradical pathways is occurring simultaneously, (ii) S-nitrosation through direct addition of NO to thiol does not occur to any meaningful extent, and (iii) protein hydrophobic environments do not catalyze or enhance S-nitrosation of either themselves or of glutathione. We conclude that S-nitrosation and disulfide formation in this system occur only after the initial reaction between NO and oxygen to form nitrogen dioxide, and that hydrophobic protein environments are unlikely to play any role in enhancing and targeting S-nitrosothiol formation.
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The G protein-coupled receptor 87 is necessary for p53-dependent cell survival in response to genotoxic stress.
Cancer Res.
PUBLISHED: 07-14-2009
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p53 regulates an array of target genes, which mediates p53 tumor suppression by inducing cell cycle arrest, apoptosis, and cell survival. G protein-coupled receptors belong to a superfamily of cell surface molecules and are known to regulate cell proliferation, migration, and survival. Here, we found that G protein-coupled receptor 87 (GPR87) was up-regulated by p53 and by DNA damage in a p53-dependent manner. We also found that p53 directly regulated GPR87 potentially via a p53-responsive element in the GPR87 gene. To investigate the role of GPR87 in the p53 pathway, we generated multiple RKO and MCF7 cell lines in that GPR87 can be inducibly overexpressed or knocked down by a tetracycline-inducible system. We found that overexpression of GPR87 had little effect on cell growth. However, GPR87 knockdown sensitized cancer cells to DNA damage-induced growth suppression via enhanced p53 stabilization and activation. Importantly, the prosurvival activity of GPR87 can be reversed by knockdown of p53. Together, our results suggested that GPR87 is essential for p53-dependent cell survival in response to DNA damage. Thus, due to its expression on the cell surface and its role in cell survival, GPR87 may be explored as a novel therapeutic target for cancer treatment and prevention.
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Responses of free radicals to subcutaneous implantation of alginate-chitosan-alginate (ACA) microcapsules in mice.
Int J Artif Organs
PUBLISHED: 07-02-2009
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The objective of this study was to characterize the levels of free radicals in serum and antioxidase activity after microcapsules were implanted into the subcutaneous space of mice. cell viability was evaluated using ao/Eb staining. serum free radicals, malondialdehyde and superoxide dismutase levels were evaluated by colorimetry analysis. the mice were divided into three groups: saline injection group (n=15), empty microcapsules injected group (n=21), encapsulated cells injected group (n=21). cell viability and serum analysis were executed at 1, 4 and 7 days post-implantation. Hydrogen peroxide and malondialdehyde levels initially increased in the recipients of the empty microcapsules, before decreasing to the basal level. However, in mice receiving the encapsulated cells, the levels were higher at the end of study. nitric oxide and superoxide dismutase increased after the implantation of microcapsules with or without the bHK-21 cells, but were not changed in response to the saline injection. the viability of the encapsulated cells was high in vivo, although some microcapsules had broken by 7 days post-implantation. these results suggest that nitric oxide plays a role in the specific response to microcapsules. the levels of free radicals rapidly increased immediately following microcapsule transplantation, but they caused only slight cellular damage before the microencapsulated cells were exposed.
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Proliferating cell nuclear antigen destabilizes c-Abl tyrosine kinase and regulates cell apoptosis in response to DNA damage.
Apoptosis
PUBLISHED: 01-22-2009
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The tyrosine kinase, c-Abl, plays important roles in many aspects of cellular function. The activity of c-Abl is tightly controlled, but the underlying mechanism is unclear. Recent studies suggest that c-Abl function is regulated by distinct lipids in different cell types. In the present study, we show that the DNA replication factor, proliferating cell nuclear antigen (PCNA), interacts with c-Abl and destabilizes c-Abl by promoting its polyubiquitination and degradation. Moreover, deletion of a domain in c-Abl, the PIP box, disrupts its interaction with PCNA, abolishes the PCNA-induced degradation of nuclear c-Abl, and substantially increases the nuclear c-Abl apoptotic function. These findings indicate that PCNA negatively regulates the stability of c-Abl and thereby inhibits apoptosis in the response to DNA damage.
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Development of a disease-specific health-related quality of life questionnaire for patients with post-stroke spasticity.
J Tradit Chin Med
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This study was designed to develop a disease-specific health-related quality of life (HR-QOL) measure for patients with post-stroke spasticity.
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Arsenic suppresses cell survival via Pirh2-mediated proteasomal degradation of ?Np63 protein.
J. Biol. Chem.
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Transcription factor p63, a member of the p53 family, shares a high degree of sequence similarity with p53. Because of transcription from two distinct promoters, the p63 gene encodes two isoforms, TAp63 and ?Np63. Although TAp63 acts as a tumor suppressor, ?Np63 functions as an oncogene and is often overexpressed in squamous cell carcinomas. Thus, therapeutic agents targeting ?Np63 might be used to manage tumors that overexpress ?Np63. Here we found that arsenic trioxide, a frontline agent for acute promyelocytic leukemia, inhibits ?Np63 but not TAp63 expression in time- and dose-dependent manners. In addition, we found that arsenic trioxide decreases the stability of ?Np63 protein via a proteasome-dependent pathway but has little effect on the level of ?Np63 transcript. Furthermore, we found that arsenic trioxide activates the Pirh2 promoter and consequently induces Pirh2 expression. Consistent with this, we found that knockdown of Pirh2 inhibits, whereas ectopic expression of Pirh2 enhances, arsenic-induced degradation of ?Np63 protein. Importantly, we found that knockdown of ?Np63 sensitizes, whereas ectopic expression of ?Np63 inhibits, growth suppression induced by arsenic. Together, these data suggest that arsenic degrades ?Np63 protein at least in part via Pirh2-dependent proteolysis and that inhibition of ?Np63 expression facilitates tumor cells to arsenic-induced death.
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[Analysis of binary classification repeated measurement data with GEE and GLMMs using SPSS software].
Nan Fang Yi Ke Da Xue Xue Bao
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To analyze binary classification repeated measurement data with generalized estimating equations (GEE) and generalized linear mixed models (GLMMs) using SPSS19.0.
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HuR is necessary for mammary epithelial cell proliferation and polarity at least in part via ?Np63.
PLoS ONE
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HuR, a RNA binding protein, is known to function as a tumor maintenance gene in breast cancer and associated with tumor growth and poor prognosis. However, the cellular function of this protein remains largely unknown in normal mammary epithelial cells. Here, we showed that in immortalized MCF10A mammary epithelial cells, HuR knockdown inhibits cell proliferation and enhances premature senescence. We also showed that in three-dimensional culture, MCF10A cells with HuR knockdown form abnormal acini with filled lumen and an aberrant expression pattern of the extracellular matrix protein laminin V. In addition, we showed that HuR knockdown increases ?Np63, but decreases wild-type p53, expression in MCF10A cells. Moreover, we showed that ?Np63 knockdown partially rescues the proliferative defect induced by HuR knockdown in MCF10A cells. Consistent with this, we identified two U-rich elements in the 3-untranslated region of p63 mRNA, to which HuR specifically binds. Finally, we showed that HuR knockdown enhances ?Np63 mRNA translation but has no effect on p63 mRNA turnover. Together, our data suggest that HuR maintains cell proliferation and polarity of mammary epithelial cells at least in part via ?Np63.
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In ovo leptin administration affects hepatic lipid metabolism and microRNA expression in newly hatched broiler chickens.
J Anim Sci Biotechnol
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A leptin-like immunoreactive substance has been found in chicken eggs and has been implicated in serving as a maternal signal to program offspring growth and metabolism. In the present study, we investigated the effects of in ovo leptin administration on hatch weight, serum and hepatic concentrations of metabolites and hormones, as well as on the expression of genes involved in hepatic lipid metabolism and the predicted microRNAs (miRNAs) targeting the affected genes. To this end we injected fertile eggs with either 0.5 ?g of recombinant murine leptin or vehicle (PBS) before incubation.
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Identification of tyrosine-9 of MAVS as critical target for inducible phosphorylation that determines activation.
PLoS ONE
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Innate immunity to viruses involves receptors such as RIG-I, which senses viral RNA and triggers an IFN-? signaling pathway involving the outer mitochondrial membrane protein MAVS. However, the functional status of MAVS phosphorylation remains elusive.
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Production of recombinant orange-spotted grouper (Epinephelus coioides) follicle-stimulating hormone (FSH) in single-chain form and dimer form by Pichia pastoris and their biological activities.
Gen. Comp. Endocrinol.
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FSH is a key regulator of steroidogenesis and gonadal growth in teleosts. However, function of FSH is elusive in grouper due to the lack of purified and native FSH. In the present study, we reported production of bioactive orange-spotted grouper (Epinephelus coioides) FSH in dimer form and single-chain form by Pichia pastoris. Dimer form of recombinant grouper FSH (rgFSHba) was accomplished by co-expressing mature FSHb-subunit and a-subunit genes. Fusion of mature FSHb-subunit and a-subunit genes together linking with a polypeptide (4×(Gly-Ser)-Gly-Thr) gene generated single-chain form of recombinant grouper FSH (rgFSHb-a). Recombinant grouper common ?-subunit (rgCga) and FSHb-subunit (rgFSHb) were also separately produced. Recombinant proteins were verified by Western blot and mass spectrometry assays, and characterized by deglycosylation analysis. Deglycosylation assay suggested that glycosylation of recombinant FSH mainly occurred on common a-subunit. Bioactivities of recombinant proteins were initially evaluated by activating grouper FSH receptor, and further demonstrated by incubating ovarian fragments of adult grouper and intraperitoneal injection in juvenile female grouper. Two forms of recombinant FSH presented similar biological activities of activating FSH receptor and stimulating in vitro testosterone (T) and estradiol-17? (E2) secretion, though the dimer form functioned slightly weaker than the single-chain form. However, injections of rgFSHb-a or rgFSHba could significantly increase serum T and E2 levels, induce early ovarian development, reduce hypothalamic gnrh1 mRNA level, and increase hypothalamic cyp19a1b mRNA level. Data in this study suggested that recombinant gonadotropin could be produced in dimer form or single-chain form by P. pastoris, and FSH could regulate steroidogenesis and early ovarian development in juvenile grouper.
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p73 expression is regulated by RNPC1, a target of the p53 family, via mRNA stability.
Mol. Cell. Biol.
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p73, a p53 family tumor suppressor, is expressed as TA and ?N isoforms. Due to the role of p73 in tumor suppression and neural development, its expression and activity are tightly regulated by multiple mechanisms, including transcription and posttranslational modifications. Here, we found that p73 mRNA stability is regulated by RNPC1, an RNA binding protein and a target of the p53 family. We also showed that a CU-rich element in the 3 untranslated region of p73 is recognized by and responsive to RNPC1. To explore the physiological significance of RNPC1-regulated p73 expression, we showed that the loss of RNPC1 in p53-null mouse embryonic fibroblasts leads to reduced expression of p73, along with decreased expression of p21, p130, and ?-H2A.X, and consequently a decreased number of senescent cells. Furthermore, we observed that knockdown of TAp73 or p21, another target of RNPC1, attenuates the inhibitory effect of RNPC1 on cell proliferation and premature senescence, whereas combined knockdown of TAp73 and p21 completely abolishes it. Due to the fact that RNPC1 is a target of p73, the mutual regulation between p73 and RNPC1 constitutes a novel feed-forward loop, which might be explored as a target for tumors without a functional p53.
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Mammary epithelial cell polarity is regulated differentially by p73 isoforms via epithelial-to-mesenchymal transition.
J. Biol. Chem.
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p73 is expressed as TA and ?N isoforms, both of which are implicated in tumor suppression and/or promotion. To address how p73 possesses these opposing functions, we developed three-dimensional culture of MCF10A cells, which undergo cell morphogenesis to form polarized spheroids with hollow lumen similar to normal mammary acini in vivo. Here, we showed that upon knockdown of p73, particularly TAp73 but not ?Np73, MCF10A cells formed irregular and near-normal acini without hollow lumen in three-dimensional culture. We also found that upon knockdown of p73 or TAp73, but not ?Np73, MCF10A cells underwent epithelial-to-mesenchymal transition (EMT) via down-regulation of E-cadherin coupled with up-regulation of ?-catenin and laminin V. In addition, we found that Snail-1, Slug, and Twist, all of which are known to act as EMT inducers by repressing E-cadherin expression, were increased markedly upon knockdown of p73 and TAp73 but little if any by ?Np73. Furthermore, we showed that knockdown of p73 or TAp73 in MCF10A cells led to a marked increase in cell proliferation and migration. Together, our data suggest that TAp73 is necessary for maintaining normal cell polarity by suppressing EMT.
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Activation of inflammatory responses in human U937 macrophages by particulate matter collected from dairy farms: an in vitro expression analysis of pro-inflammatory markers.
Environ Health
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The purpose of the present study was to investigate activation of inflammatory markers in human macrophages derived from the U937 cell line after exposure to particulate matter (PM) collected on dairy farms in California and to identify the most potent components of the PM.
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Stimulatory effects of chitinase on growth and immune defense of orange-spotted grouper (Epinephelus coioides).
Fish Shellfish Immunol.
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Chitinase, belonging to either family 18 or family 19 of the glycosylhydrolases, hydrolyze chitin into oligosaccharides. In the present study, the cDNA fragment encoding orange-spotted grouper (Epinephelus coioides) chitinase1 was subcloned into pPIC3.5K vector and expressed in Pichia pastoris GS115. The results showed that a band with the size of about 53 kDa could be detected by SDS-PAGE and Western blot. The recombinant protein of grouper chitinase1 (rgChi1) was added into the fish diet containing shrimp shell chitin for feeding experiment lasting 8 weeks. The weight of orange-spotted grouper, fed with diets containing rgChi1 at 0, 5, 10 and 20 ?g/g was calculated on the 2nd, 4th, 6th and 8th weeks, and difference in growth rates was first observed in the 6th week of the feeding period and it kept until the end of the feeding experiment. At the end of 8 weeks feeding trial, the percent weight gain (PWG), growth rate (GR) and specific growth rate (SGR) of fish fed with 10 and 20 ?g rgChi1/g feed were significantly higher compared to the control group. The neuropeptide Y (NPY), growth-hormone-releasing hormone (GHRH), growth-hormone (GH), interleukin-1beta (IL-1?), cyclooxygenase-2 (COX-2), superoxide dismutase (SOD) (Cu/Zn) and SOD (Mn) mRNA expression of fish fed with diet containing 10 ?g/g or/and 20 ?g/g rgChi1 were obviously higher than the control group. The lysozyme (LZM) and total SOD activity of fish fed with diet containing rgChi1 at 10 and 20 ?g/g were significantly higher than that of the control. The aspartate aminotransferase (AST)/glutamic oxalacetic transaminases (GOT) activity in 20 ?g/g group decreased compared to the control group. These results indicated that the grouper chitinase1 was successfully produced using the P. pastoris expression system and the recombinant protein had obvious effects on growth and immune defense. The mRNA expression and protein secretion of grouper chitinase1 and chitinase2 were significantly stimulated in spleen in response to bacterial lipopolysaccharide (LPS) challenge, strongly suggesting the existence of an innate pathway for local defense against chitin-containing organisms. Moreover, the pathogen such as Escherichia coli and Staphylococcus aureus could be inhibited by the recombinant protein of grouper chitinase1 to a certain extent.
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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.