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1.  A Phosphate-Binding Pocket Within the Platform-PAZ-Connector Helix Cassette of Human Dicer 
Molecular cell  2014;53(4):606-616.
We have solved two families of crystal structures of human Dicer ‘platform-PAZ-connector helix’ cassette in complex with siRNAs. The structures possess two adjacently positioned pockets: a 2-nucleotide 3′-overhang-binding pocket within the PAZ domain (3′-pocket) and a newly identified phosphate-binding pocket within the platform domain (phosphate pocket). One family of complexes contain a knob-like α-helical protrusion, designated ‘hDicer-specific helix’, that separates the two pockets and orients the bound siRNA away from the surface of Dicer, which could be indicative of a product release/transfer state. In the second complex, the helical protrusion is melted/disordered and the bound siRNA is aligned towards the surface of Dicer, suggestive of a cleavage-competent state. These structures allow us to propose that the transition from the cleavage-competent to the postulated product release/transfer state may involve release of the 5′-phosphate from the phosphate pocket, while retaining the 3′-overhang in the 3′-pocket.
PMCID: PMC4217634  PMID: 24486018
2.  Quantitative glycoproteomic analysis of OCT-embedded frozen tissues identifies glycoproteins associated with aggressive prostate cancer 
Analytical chemistry  2011;83(18):7013-7019.
Prostate cancer is the most common malignancy in men in the United States, and one in seven men with prostate cancer dies of the disease. A major issue of prostate diagnosis is that there is no good method to reliably distinguish aggressive prostate cancer from non-aggressive prostate cancer. This leads to significant unnecessary suffering among prostate cancer patients and massive unnecessary health care expenditures. In this study, we aim to identify glycoproteins associated with aggressive prostate cancer using OCT-embedded frozen tissues obtained from patients with known clinical outcome. To eliminate the interfering of mass spectrometric analysis by the compounds in OCT and identify extracellular proteins that are likely to serve as biomarkers in body fluids, we employed the glycoproteomic analysis using solid-phase extraction of glycopeptides, which allowed the immobilization of glycopeptides to solid support and removal of OCT from sample proteins before releasing the glycopeptides from solid support for mass spectrometry analysis. Tumor tissues were cryostat microdissected from 4 cases of aggressive and 4 cases of non-aggressive prostate tumors, and glycopeptides were isolated and labeled with iTRAQ reagents before the samples were analyzed with LTQ Orbitrap Velos. From the aggressive prostate cancer tissues, we identified the overexpression of four glycoproteins involved in extracellular matrix remodeling and further verified two glycoproteins, cathepsin L and periostin, using Western blot and immunohistochemistry analyses. This is the first proteomic study to identify proteins associated with aggressive prostate cancer using OCT-embedded frozen tissues. Further study of these proteins will be needed to understand the roles of extracellular matrix proteins in cancer progression and their potential clinical utility in improving diagnosis of aggressive prostate cancer.
PMCID: PMC4285776  PMID: 21780747
prostate cancer; aggressive tumor; tumor metastasis; glycoprotein; OCT-embedded frozen tissue
3.  RIOK3 Is an Adaptor Protein Required for IRF3-Mediated Antiviral Type I Interferon Production 
Journal of Virology  2014;88(14):7987-7997.
Detection of cytosolic nucleic acids by pattern recognition receptors leads to the induction of type I interferons (IFNs) and elicits the innate immune response. We report here the identification of RIOK3 as a novel adaptor protein that is essential for the cytosolic nucleic acid-induced type I IFN production and for the antiviral response to gammaherpesvirus through two independent kinome-wide RNA interference screens. RIOK3 knockdown blocks both cytosolic double-stranded B-form DNA and double-stranded RNA-induced IRF3 activation and IFN-β production. In contrast, the overexpression of RIOK3 activates IRF3 and induces IFN-β. RIOK3 functions downstream of TBK1 and upstream of IRF3 activation. Furthermore, RIOK3 physically interacts with both IRF3 and TBK1 and is necessary for the interaction between TBK1 and IRF3. In addition, global transcriptome analysis shows that the expression of many gene involved antiviral responses is dependent on RIOK3. Thus, knockdown of RIOK3 inhibits cellular antiviral responses against both DNA and RNA viruses (herpesvirus and influenza A virus). Our data suggest that RIOK3 plays a critical role in the antiviral type I IFN pathway by bridging TBK1 and IRF3.
IMPORTANCE The innate immune response, such as the production of type I interferons, acts as the first line of defense, limiting infectious pathogens directly and shaping the adaptive immune response. In this study, we identified RIOK3 as a novel regulator of the antiviral type I interferon pathway. Specifically, we found that RIOK3 physically interacts with TBK1 and IRF3 and bridges the functions between TBK1 and IRF3 in the activation of type I interferon pathway. The identification of a cellular kinase that plays a role the type I interferon pathway adds another level of complexity in the regulation of innate immunity and will have implications for developing novel strategies to combat viral infection.
PMCID: PMC4097797  PMID: 24807708
4.  Overexpression of Tbx3 is correlated with Epithelial-Mesenchymal Transition phenotype and predicts poor prognosis of colorectal cancer 
Aims: To investigate the clinical significance of Tbx3 in colorectal cancer (CRC) and the possible association between Tbx3 expression and Epithelial- Transition Mesenchymal (EMT) phenotype. Methods: Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) and western blotting were employed to evaluate the expression of Tbx3 in 30 fresh CRC and matched normal tissues. Using immunochemistry, protein level of Tbx3 and EMT markers (E-cadherin and N-cadherin) were identified in 150 pairs of paraffin-embedded specimen. Results: The results of qRT-PCR and western blotting showed that Tbx3 expression was higher in CRC tissues than in corresponding normal tissues. The statistical analysis based on immunohistochemical evaluation suggested that Tbx3 aberrant expression was significantly associated with tumor size (P=0.049), differentiation (P=0.032), invasion (P=0.019), lymph node metastasis (P=0.049) and TNM stage (P=0.018). Patients who displayed high expression of Tbx3 may achieve a poorer overall survival (OS) and disease-free survival (DFS), compared to those with low expression of Tbx3. This tendency was also observed in patients with intermediate levels of disease (II and III stage). The multivariate analysis indicated Tbx3 expression could independently predict the outcome of CRC patients. Interestingly, correlation analysis suggested Tbx3 expression was negatively correlated with E-cadherin expression, but positively correlated with N-cadherin expression. Conclusion: Tbx3 may promote CRC progression by involving EMT program and has the potential to be an effective prognostic predictor for CRC patients.
PMCID: PMC4300685  PMID: 25628943
Tbx3; Epithelial-Mesenchymal Transition; colorectal cancer; prognosis; biomarker
5.  High expression of Y-box-binding protein 1 is associated with local recurrence and predicts poor outcome in patients with colorectal cancer 
Colorectal cancer (CRC) is one of the most common and fatal malignancies worldwide. Novel prognostic biomarkers are urgently warranted to help improve the treatment of CRC. Y-box-binding protein 1 (YB-1) has been identified as a multifunctional oncoprotein in various malignancies. Our previous study has suggested that YB-1 may promote malignant progression of CRC cells in vitro. However, its clinical and prognostic significance in CRC patients remains unclear. In this study, the expression of YB-1 was examined in 32 fresh CRC tissues using quantitative real-time polymerase chain reaction (qRT-PCR) and in 170 paraffin-embedded CRC tissues using immunohistochemistry. The result of qRT-PCR demonstrated mRNA expression of YB-1 was increased in 26 of 32 (81.25%) of CRC patients. The statistical analysis based on immunohistochemical staining suggested that YB-1 expression was significantly correlated with tumor differentiation, tumor invasion, lymph node metastasis and Dukes’ classification (all P<0.05). Furthermore, we found that patients with high YB-1 expression had a poorer prognosis and were more likely to undergo local recurrence, compared to those with low YB-1 expression. We also identified that YB-1 expression, together with lymph node metastasis and Dukes’ classification were independent prognostic factors for CRC patients. In conclusion, our study for the first time demonstrated the clinical and prognostic significance of YB-1 in CRC and suggested that YB-1 is of great potential to be an attractive therapeutic target as well as prognostic biomarker for CRC patients.
PMCID: PMC4314019
YB-1; colorectal cancer; prognosis; local recurrence
6.  Identification, prioritization and evaluation of glycoproteins for aggressive prostate cancer using quantitative glycoproteomics and antibody-based assays on tissue specimens 
Proteomics  2013;13(15):2268-2277.
Prostate cancer is highly heterogeneous in nature; while the majority of cases are clinically insignificant, some cases are lethal. Currently, there are no reliable screening methods for aggressive prostate cancer. Since most established serum and urine biomarkers are glycoproteins secreted or leaked from the diseased tissue, the current study seeks to identify glycoprotein markers specific to aggressive prostate cancer using tissue specimens. With LC-MS/MS glycoproteomic analysis, we identified 350 glycopeptides with 17 being altered in aggressive prostate cancer. ELISA assays were developed/purchased to evaluate 4 candidates, i.e. cartilage oligomeric matrix protein (COMP), periostin, membrane primary amine oxidase (VAP-1) and cathepsin L, in independent tissue sets. In agreement with the proteomic analysis, we found that COMP and periostin expressions were significantly increased in aggressive prostate tumors while VAP-1 expression was significantly decreased in aggressive tumor. In addition, the expression of these proteins in prostate metastases also follows the same pattern observed in the proteomic analysis. This study provides a workflow for biomarker discovery, prioritization and evaluation of aggressive prostate cancer markers using tissue specimens. Our data suggest increase in COMP and periostin and decrease in VAP-1 expression in the prostate may be associated with aggressive prostate cancer.
PMCID: PMC4235679  PMID: 23716368
aggressive; prostate cancer; biomarker; glycoproteomics; OCT
7.  Zinc Supplementation Inhibits Complement Activation in Age-Related Macular Degeneration 
PLoS ONE  2014;9(11):e112682.
Age-related macular degeneration (AMD) is the leading cause of blindness in the Western world. AMD is a multifactorial disorder but complement-mediated inflammation at the level of the retina plays a pivotal role. Oral zinc supplementation can reduce the progression of AMD but the precise mechanism of this protective effect is as yet unclear. We investigated whether zinc supplementation directly affects the degree of complement activation in AMD and whether there is a relation between serum complement catabolism during zinc administration and the complement factor H (CFH) gene or the Age-Related Maculopathy susceptibility 2 (ARMS2) genotype. In this open-label clinical study, 72 randomly selected AMD patients in various stages of AMD received a daily supplement of 50 mg zinc sulphate and 1 mg cupric sulphate for three months. Serum complement catabolism–defined as the C3d/C3 ratio–was measured at baseline, throughout the three months of supplementation and after discontinuation of zinc administration. Additionally, downstream inhibition of complement catabolism was evaluated by measurement of anaphylatoxin C5a. Furthermore, we investigated the effect of zinc on complement activation in vitro. AMD patients with high levels of complement catabolism at baseline exhibited a steeper decline in serum complement activation (p<0.001) during the three month zinc supplementation period compared to patients with low complement levels. There was no significant association of change in complement catabolism and CFH and ARMS2 genotype. In vitro zinc sulphate directly inhibits complement catabolism in hemolytic assays and membrane attack complex (MAC) deposition on RPE cells. This study provides evidence that daily administration of 50 mg zinc sulphate can inhibit complement catabolism in AMD patients with increased complement activation. This could explain part of the mechanism by which zinc slows AMD progression.
Trial Registration
The Netherlands National Trial Register NTR2605
PMCID: PMC4231060  PMID: 25393287
8.  Effect of galectin-3 on the behavior of Eca-109 human esophageal cancer cells 
Molecular Medicine Reports  2014;11(2):896-902.
Galectin-3, a β-galactoside-binding lectin, is a cell adhesion molecule involved in the regulation of tumor progression. However, the importance of galectin-3 in Eca-109 human esophageal cancer cells has not yet been elucidated. In the present study, a lentiviral vector was designed for overexpression of galectin-3 in Eca-109 cells following plasmid-mediated transfection (Eca-109/Gal-3 cells). A negative lentiviral vector was introduced into Eca-109 cells as a control (Eca-109/Neo cells). Western blot and reverse transcription-polymerase chain reaction analyses were used to measure the expression levels of galectin-3 protein and mRNA. The proliferation of Eca-109 cells was measured by a cell counting kit-8 assay. Eca-109 cell apoptosis was determined by Annexin V/7-amino-actinomycin double-staining. The migration and invasion capacity of Eca-109 cells was determined by a Transwell assay. A total of >98% Eca-109 cells were transfected with the lentiviral vector harboring galectin-3, and galectin-3 expression was detected in Eca-109 cells, Eca-109/Gal-3 cells and Eca-109/Neo cells. Compared with non-transfected and negative control Eca-109 cells, proliferation was increased significantly in the Eca-109/Gal-3 cells (P<0.05). Galectin-3 also significantly reduced Eca-109 cell apoptosis, compared with the two control groups (P=0.007 and P=0.04, respectively). Transwell migration and invasion assays revealed that significantly greater numbers of Eca-109/Gal-3 cells crossed the artificial basement membrane (55.4±3.9) compared with either the non-transfected or negative control Eca-109 cells (30.6±1.5 and 29±2.6 respectively, P<0.05). In conclusion, galectin-3 expression was significantly increased in transfected Eca-109 esophageal cancer cells, resulting in enhanced proliferation, migration and invasion, as well as reduced apoptosis. These data indicate that galectin-3 may be a potential molecular target in the treatment of esophageal cancer.
PMCID: PMC4262483  PMID: 25373317
esophageal carcinoma; galectin-3; Eca-109 cells
9.  A Novel Fungal Hyperparasite of Puccinia striiformis f. sp. tritici, the Causal Agent of Wheat Stripe Rust 
PLoS ONE  2014;9(11):e111484.
Puccinia striiformis f. sp. tritici (Pst), the causal fungus of wheat stripe rust, was previously reported to be infected by Lecanicillium lecanii, Microdochium nivale and Typhula idahoensis. Here, we report a novel hyperparasite on Pst. This hyperparasitic fungus was identified as Cladosporium cladosporioides (Fresen.) GA de Vries based on morphological characteristics observed by light and scanning electron microscopy together with molecular data. The hyperparasite reduced the production and viability of urediniospores and, therefore, could potentially be used for biological control of wheat stripe rust.
PMCID: PMC4219752  PMID: 25369036
10.  Utility of Clostridium difficile Toxin B for Inducing Anti-Tumor Immunity 
PLoS ONE  2014;9(10):e110826.
Clostridium difficile toxin B (TcdB) is a key virulence factor of bacterium and induces intestinal inflammatory disease. Because of its potent cytotoxic and proinflammatory activities, we investigated the utility of TcdB in developing anti-tumor immunity. TcdB induced cell death in mouse colorectal cancer CT26 cells, and the intoxicated cells stimulated the activation of mouse bone marrow-derived dendritic cells and subsequent T cell activation in vitro. Immunization of BALB/c mice with toxin-treated CT26 cells elicited potent anti-tumor immunity that protected mice from a lethal challenge of the same tumor cells and rejected pre-injected tumors. The anti-tumor immunity generated was cell-mediated, long-term, and tumor-specific. Further experiments demonstrated that the intact cell bodies were important for the immunogenicity since lysing the toxin-treated tumor cells reduced their ability to induce antitumor immunity. Finally, we showed that TcdB is able to induce potent anti-tumor immunity in B16-F10 melanoma model. Taken together, these data demonstrate the utility of C. difficile toxin B for developing anti-tumor immunity.
PMCID: PMC4207755  PMID: 25340750
11.  Gas phase studies of substrates for the DNA mismatch repair enzyme MutY 
Journal of the American Chemical Society  2012;134(48):19839-19850.
The gas phase thermochemical properties (tautomeric energies, acidity, and proton affinity) have been measured and calculated for adenine and six adenine analogs that were designed to test features of the catalytic mechanism used by the adenine glycosylase MutY. The gas phase intrinsic properties are correlated to possible excision mechanisms and MutY excision rates to gain insight into the the MutY mechanism. The data support a mechanism involving protonation at N7 and hydrogen bonding to N3 of adenine. We also explored the acid-catalyzed (non-enzymatic) depurination of these substrates, which appears to follow a different mechanism than that employed by MutY, which we elucidate using calculations.
PMCID: PMC4204490  PMID: 23106240
12.  Alteration in basal and depolarization induced transcriptional network in iPSC derived neurons from Timothy syndrome 
Genome Medicine  2014;6(10):75.
Common genetic variation and rare mutations in genes encoding calcium channel subunits have pleiotropic effects on risk for multiple neuropsychiatric disorders, including autism spectrum disorder (ASD) and schizophrenia. To gain further mechanistic insights by extending previous gene expression data, we constructed co-expression networks in Timothy syndrome (TS), a monogenic condition with high penetrance for ASD, caused by mutations in the L-type calcium channel, Cav1.2.
To identify patient-specific alterations in transcriptome organization, we conducted a genome-wide weighted co-expression network analysis (WGCNA) on neural progenitors and neurons from multiple lines of induced pluripotent stem cells (iPSC) derived from normal and TS (G406R in CACNA1C) individuals. We employed transcription factor binding site enrichment analysis to assess whether TS associated co-expression changes reflect calcium-dependent co-regulation.
We identified reproducible developmental and activity-dependent gene co-expression modules conserved in patient and control cell lines. By comparing cell lines from case and control subjects, we also identified co-expression modules reflecting distinct aspects of TS, including intellectual disability and ASD-related phenotypes. Moreover, by integrating co-expression with transcription factor binding analysis, we showed the TS-associated transcriptional changes were predicted to be co-regulated by calcium-dependent transcriptional regulators, including NFAT, MEF2, CREB, and FOXO, thus providing a mechanism by which altered Ca2+ signaling in TS patients leads to the observed molecular dysregulation.
We applied WGCNA to construct co-expression networks related to neural development and depolarization in iPSC-derived neural cells from TS and control individuals for the first time. These analyses illustrate how a systems biology approach based on gene networks can yield insights into the molecular mechanisms of neural development and function, and provide clues as to the functional impact of the downstream effects of Ca2+ signaling dysregulation on transcription.
Electronic supplementary material
The online version of this article (doi:10.1186/s13073-014-0075-5) contains supplementary material, which is available to authorized users.
PMCID: PMC4213483  PMID: 25360157
13.  MicroRNA-27a promotes proliferation and suppresses apoptosis by targeting PLK2 in laryngeal carcinoma 
BMC Cancer  2014;14(1):678.
miRNA-27a has been confirmed as an important regulator in carcinogenesis and other pathological processes. Whether and how it plays a role in the laryngeal carcinoma is unknown.
Mature miRNA-27a expression in laryngeal cancer was detected by qRT-PCR. Gain-of-function studies using mature miR-27a were performed to investigate cell proliferation and apoptosis in the Hep2 cells. In silico database analysis and luciferase reporter assay were applied to predict and validate the direct target, respectively. Loss-of-function assays were performed to investigate the functional significance of the miR-27a target gene. qRT-PCR and Western blot were used to evaluate mRNA and protein levels of the target, respectively.
miR-27a was significantly up-regulated in the laryngeal tumor tissues compared to the adjacent non-tumor tissues. In silico database analysis result revealed that PLK2 is a potential target of miR-27a. luciferase reporter assay result showed the direct inhibition of miR-27a on PLK2-3′UTR. In the cases with miR-27a up-regulation, PLK2 protein expression level was significantly lower in cancer tissues than that in the adjacent non-tumor tissues, which showed a negative correlation with miR-27a expression level. Both miR-27a and knockdown of PLK2 caused the increase of the cell viability and colony formation and inhibition of the late apoptosis in the Hep2 cell lines. Moreover, miR-27a but not PLK2 also repressed the early apoptosis in the Hep2 cells. Additionally, no alteration of the Hep2 cell cycle induced by miR-27a was detected.
miR-27a acts as an oncogene in laryngeal squamous cell carcinoma through down-regulation of PLK2 and may provide a novel clue into the potential mechanism of LSCC oncogenesis or serve as a useful biomarker in diagnosis and therapy in laryngeal cancer.
Electronic supplementary material
The online version of this article (doi:10.1186/1471-2407-14-678) contains supplementary material, which is available to authorized users.
PMCID: PMC4177177  PMID: 25239093
Laryngeal squamous cell carcinoma; miR-27a; PLK2; Apoptosis; Proliferation
14.  Large Area Stress Distribution in Crystalline Materials Calculated from Lattice Deformation Identified by Electron Backscatter Diffraction 
Scientific Reports  2014;4:5934.
We report a method to obtain the stress of crystalline materials directly from lattice deformation by Hooke's law. The lattice deformation was calculated using the crystallographic orientations obtained from electron backscatter diffraction (EBSD) technology. The stress distribution over a large area was obtained efficiently and accurately using this method. Wurtzite structure gallium nitride (GaN) crystal was used as the example of a hexagonal crystal system. With this method, the stress distribution of a GaN crystal was obtained. Raman spectroscopy was used to verify the stress distribution. The cause of the stress distribution found in the GaN crystal was discussed from theoretical analysis and EBSD data. Other properties related to lattice deformation, such as piezoelectricity, can also be analyzed by this novel approach based on EBSD data.
PMCID: PMC4121609  PMID: 25091314
15.  Expression of astrocyte elevated gene-1 (AEG-1) as a biomarker for aggressive pancreatic ductal adenocarcinoma 
BMC Cancer  2014;14:479.
Altered expression of astrocyte elevated gene-1 (AEG-1) is associated with tumorigenesis and progression. The present study aimed to investigate the clinical and prognostic significance of AEG-1 expression in pancreatic ductal adenocarcinoma (PDAC).
Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and Western blot analyses were employed to assess AEG-1 expression in three pancreatic cancer cell lines and normal pancreatic duct epithelial cells. qRT-PCR and immunohistochemical analyses were performed to detect AEG-1 expression in ten pairs of PDAC and normal pancreas tissues. Immunohistochemistry was then used to examine AEG-1 expression in paraffin-embedded tissues obtained from 105 patients, and its association with clinicopathological parameters including cancer classification was examined. Kaplan-Meier analysis was performed to study the survival rates of patients.
Expression of AEG-1 mRNA and protein was markedly higher in pancreatic cancer cell lines than that in the normal pancreatic duct epithelial cells. AEG-1 expression was evidently upregulated in PDAC tissues compared to that of the matched distant normal pancreas tissues. qRT-PCR data revealed that the tumor/non-tumor ratio of AEG-1 expression was >1.5-fold (up to 6.5-fold). Immunohistochemical data showed that AEG-1 protein was detected in 98.09% (103/105) of PDAC tissues; and they were found to be associated with tumor size (P = 0.025), advanced clinical stage (P = 0.004), T classification (P = 0.006), N classification (P = 0.003), and M classification (P = 0.007). Furthermore, Kaplan-Meier analysis showed that patients with high AEG-1-expressed PDAC had shorter overall survival. A multivariate Cox regression analysis revealed that clinical stage, T classification, and AEG-1 expression were the independent prognostic predictors for PDAC.
This study suggests that AEG-1 protein was highly expressed in PDAC and associated with poor prognosis of the patients.
PMCID: PMC4227053  PMID: 24989027
AEG-1; Biomarker; Prognosis; Pancreatic ductal adenocarcinoma
16.  The effects of perinatal testosterone exposure on the DNA methylome of the mouse brain are late-emerging 
The biological basis for sex differences in brain function and disease susceptibility is poorly understood. Examining the role of gonadal hormones in brain sexual differentiation may provide important information about sex differences in neural health and development. Permanent masculinization of brain structure, function, and disease is induced by testosterone prenatally in males, but the possible mediation of these effects by long-term changes in the epigenome is poorly understood.
We investigated the organizational effects of testosterone on the DNA methylome and transcriptome in two sexually dimorphic forebrain regions—the bed nucleus of the stria terminalis/preoptic area and the striatum. To study the contribution of testosterone to both the establishment and persistence of sex differences in DNA methylation, we performed genome-wide surveys in male, female, and female mice given testosterone on the day of birth. Methylation was assessed during the perinatal window for testosterone's organizational effects and in adulthood.
The short-term effect of testosterone exposure was relatively modest. However, in adult animals the number of genes whose methylation was altered had increased by 20-fold. Furthermore, we found that in adulthood, methylation at a substantial number of sexually dimorphic CpG sites was masculinized in response to neonatal testosterone exposure. Consistent with this, testosterone's effect on gene expression in the striatum was more apparent in adulthood.
Taken together, our data imply that the organizational effects of testosterone on the brain methylome and transcriptome are dramatic and late-emerging. Our findings offer important insights into the long-term molecular effects of early-life hormonal exposure.
PMCID: PMC4074311  PMID: 24976947
Brain sexual differentiation; Epigenetic modifications; DNA methylation; Testosterone; Organizational effects
17.  Clinical significance of serum soluble death receptor 5 concentration in locally advanced non-small cell lung cancer patients 
Oncology Letters  2014;8(3):1333-1339.
There is an urgent requirement for the identification of suitable biomarkers for the diagnosis and prognosis of non-small cell lung cancer (NSCLC). The present study aimed to measure the levels of serum soluble death receptor 5 (sDR5) in patients with locally advanced stage III NSCLC, and to evaluate its diagnostic and prognostic significance in these patients. The sDR5 concentrations were evaluated by the enzyme-linked immunosorbent assay method in 50 healthy controls and 122 patients with locally advanced stage III NSCLC [including 57 adenocarcinoma (ADC) and 65 squamous cell carcinoma (SCC) patients], before and after concurrent chemoradiotherapy. It was found that the pretreatment sDR5 levels in patients with NSCLC were higher than the sDR5 levels of healthy controls (P<0.001). However, no significant difference in the sDR5 levels was observed between the ADC and SCC subgroups (P=0.874). According to multiple clinical classifications, a significant increase in the pretreatment serum sDR5 levels could be observed in IIIB-stage patients compared with IIIA-stage patients (P=0.009). Patients with a tumor burden >3 cm had higher pretreatment sDR5 concentration than those with a tumor burden ≤3 cm (P=0.026). Additionally, T4-stage patients had significantly higher pretreatment sDR5 levels compared with those of T1-stage patients (P<0.001). There were no significant differences between pre- and post-treatment sDR5 concentrations in the total NSCLC patient group (P=0.462), ADC subgroup (P=0.066) and SCC subgroup (P=0.052). Furthermore, when patients were divided according to therapeutic response, the pretreatment sDR5 levels in the responder patients were significantly lower compared with those of the non-responders (P<0.001). Further survival analysis showed that the patients whose pretreatment sDR5 levels were ≤14 pg/ml (cutoff value, 14 pg/ml) had a longer progression-free survival (PFS) time than patients with sDR5 levels >14 pg/ml. However, no correlation was observed between the post-treatment sDR5 levels and therapeutic response or PFS time. To the best of our knowledge, the present study results provide the first evidence that the pretreatment serum levels of sDR5 may be a useful biomarker for the diagnosis, prediction and prognosis of patients with locally advanced stage III NSCLC.
PMCID: PMC4114649  PMID: 25120719
soluble death receptor 5; non-small cell lung cancer; chemoradiotherapy
18.  Remote Ischemic Preconditioning Protects against Liver Ischemia-Reperfusion Injury via Heme Oxygenase-1-Induced Autophagy 
PLoS ONE  2014;9(6):e98834.
Growing evidence has linked autophagy to a protective role of preconditioning in liver ischemia/reperfusion (IR). Heme oxygenase-1 (HO-1) is essential in limiting inflammation and preventing the apoptotic response to IR. We previously demonstrated that HO-1 is up-regulated in liver graft after remote ischemic preconditioning (RIPC). The aim of this study was to confirm that RIPC protects against IR via HO-1-mediated autophagy.
RIPC was performed with regional ischemia of limbs before liver ischemia, and HO-1 activity was inhibited pre-operation. Autophagy was assessed by the expression of light chain 3-II (LC3-II). The HO-1/extracellular signal-related kinase (ERK)/p38/mitogen-activated protein kinase (MAPK) pathway was detected in an autophagy model and mineral oil-induced IR in vitro.
In liver IR, the expression of LC3-II peaked 12–24 h after IR, and the ultrastructure revealed abundant autophagosomes in hepatocytes after IR. Autophagy was inhibited when HO-1 was inactivated, which we believe resulted in the aggravation of liver IR injury (IRI) in vivo. Hemin-induced autophagy also protected rat hepatocytes from IRI in vitro, which was abrogated by HO-1 siRNA. Phosphorylation of p38-MAPK and ERK1/2 was up-regulated in hemin-pretreated liver cells and down-regulated after treatment with HO-1 siRNA.
RIPC may protect the liver from IRI by induction of HO-1/p38-MAPK-dependent autophagy.
PMCID: PMC4051645  PMID: 24914543
19.  Decreased interleukin 27 expression is associated with active uveitis in Behçet’s disease 
Arthritis Research & Therapy  2014;16(3):R117.
Interleukin 27 (IL-27) is an important regulator of the proinflammatory T-cell response. In this study, we investigated its role in the pathogenesis of Behçet’s disease (BD).
IL-27 mRNA in peripheral blood mononuclear cells (PBMCs) was examined by performing RT-PCRs. Cytokine levels in sera or supernatants of PBMCs, naïve CD4+ T cells, dendritic cells (DCs) and DC/T cells were determined by enzyme-linked immunosorbent assay. We used RNA interference in naïve CD4+ T cells to study the role of interferon regulatory factor 8 (IRF8) in the inhibitory effect of IL-27 on Th17 cell differentiation. Flow cytometry was used to evaluate the frequency of IL-17- and interferon γ–producing T cells.
The expression of IL-27p28 mRNA by PBMCs and IL-27 in the sera and supernatants of cultured PBMCs were markedly decreased in patients with active BD. A higher frequency of IL-17-producing CD4+ T (Th17) cells and increased IL-17 production under Th17 polarizing conditions were observed in patients with active BD. IL-27 significantly inhibited Th17 cell differentiation. Downregulation of IRF8 by RNA interference abrogated the suppressive effect of IL-27 on Th17 differentiation. IL-27 inhibited the production of IL-1β, IL-6 and IL-23, but promoted IL-10 production, by DCs. IL-27-treated DCs inhibited both the Th1 and Th17 cell responses.
The results of the present study suggest that a decreased IL-27 expression is associated with disease activity in BD patients. Low IL-27 expression may result in a higher Th1 and Th17 cell response and thereby promote the autoinflammatory reaction observed in BD. Manipulation of IL-27 may offer a new treatment modality for this disease.
PMCID: PMC4095700  PMID: 24887071
20.  Polyol Pathway Exacerbated Ischemia/Reperfusion-Induced Injury in Steatotic Liver 
Background. The polyol pathway, a bypass pathway of glucose metabolism initiated by aldose reductase (AR), has been shown to play an important role in mediating tissue ischemia/reperfusion (I/R) impairment recently. Here, we investigated how and why this pathway might affect the fatty liver following I/R. Methods. Two opposite models were created: mice with high-fat-diet-induced liver steatosis were treated with aldose reductase inhibition (ARI) and subsequent I/R; and AR-overexpressing L02 hepatocytes were sequentially subjected to steatosis and hypoxia/reoxygenation. We next investigated (a) the hepatic injuries, including liver function, histology, and hepatocytes apoptosis/necrosis; (b) the NAD(P)(H) contents, redox status, and mitochondrial function; and (c) the flux through the caspase-dependent apoptosis pathway. Results. AR-inhibition in vivo markedly attenuated the I/R-induced liver injuries, maintained the homeostasis of NAD(P)(H) contents and redox status, and suppressed the caspase-dependent apoptosis pathway. Correspondingly, AR overexpression in vitro presented the opposite effects. Conclusion. The flux through the polyol pathway may render steatotic liver greater vulnerability to I/R. Interventions targeting this pathway might provide a novel adjunctive approach to protect fatty liver from ischemia.
PMCID: PMC4055005  PMID: 24967007
21.  Quantitative Analysis of Matrine in Liquid Crystalline Nanoparticles by HPLC 
A reversed-phase high-performance liquid chromatographic method has been developed to quantitatively determine matrine in liquid crystal nanoparticles. The chromatographic method is carried out using an isocratic system. The mobile phase was composed of methanol-PBS(pH6.8)-triethylamine (50 : 50 : 0.1%) with a flow rate of 1 mL/min with SPD-20A UV/vis detector and the detection wavelength was at 220 nm. The linearity of matrine is in the range of 1.6 to 200.0 μg/mL. The regression equation is y = 10706x − 2959 (R2 = 1.0). The average recovery is 101.7%; RSD = 2.22%  (n = 9). This method provides a simple and accurate strategy to determine matrine in liquid crystalline nanoparticle.
PMCID: PMC4009329  PMID: 24834359
22.  Glycoproteomic and glycomic databases 
Clinical proteomics  2014;11(1):15.
Protein glycosylation serves critical roles in the cellular and biological processes of many organisms. Aberrant glycosylation has been associated with many illnesses such as hereditary and chronic diseases like cancer, cardiovascular diseases, neurological disorders, and immunological disorders. Emerging mass spectrometry (MS) technologies that enable the high-throughput identification of glycoproteins and glycans have accelerated the analysis and made possible the creation of dynamic and expanding databases. Although glycosylation-related databases have been established by many laboratories and institutions, they are not yet widely known in the community. Our study reviews 15 different publicly available databases and identifies their key elements so that users can identify the most applicable platform for their analytical needs. These databases include biological information on the experimentally identified glycans and glycopeptides from various cells and organisms such as human, rat, mouse, fly and zebrafish. The features of these databases - 7 for glycoproteomic data, 6 for glycomic data, and 2 for glycan binding proteins are summarized including the enrichment techniques that are used for glycoproteome and glycan identification. Furthermore databases such as Unipep, GlycoFly, GlycoFish recently established by our group are introduced. The unique features of each database, such as the analytical methods used and bioinformatical tools available are summarized. This information will be a valuable resource for the glycobiology community as it presents the analytical methods and glycosylation related databases together in one compendium. It will also represent a step towards the desired long term goal of integrating the different databases of glycosylation in order to characterize and categorize glycoproteins and glycans better for biomedical research.
PMCID: PMC3996109  PMID: 24725457
23.  One-Pot Synthesis of Graphene-Supported Monodisperse Pd Nanoparticles as Catalyst for Formic Acid Electro-oxidation 
Scientific Reports  2014;4:4501.
To synthesize monodisperse palladium nanoparticles dispersed on reduced graphene oxide (RGO) sheets, we have developed an easy and scalable solvothermal reduction method from an organic solution system. The RGO-supported palladium nanoparticles with a diameter of 3.8 nm are synthesized in N-methyl-2-pyrrolidone (NMP) and in the presence of oleylamine and trioctylphosphine, which facilitates simultaneous reduction of graphene oxide and formation of Pd nanocrystals. So-produced Pd/RGO was tested for potential use as electrocatalyst for the electro-oxidation of formic acid. Pd/RGO catalyzes formic acid oxidation very well compared to Pd/Vulcan XC-72 catalyst. This synthesis method is a new way to prepare excellent electrocatalysts, which is of great significance in energy-related catalysis.
PMCID: PMC3968451  PMID: 24675779
24.  Trichostatin A Targets the Mitochondrial Respiratory Chain, Increasing Mitochondrial Reactive Oxygen Species Production to Trigger Apoptosis in Human Breast Cancer Cells 
PLoS ONE  2014;9(3):e91610.
Histone deacetylase inhibitors (HDACIs)-based therapies have stimulated interest via their anti-tumor activities, including apoptosis induction, cell cycle arrest, cell differentiation, and autophagy. However, the mechanisms of HDACI-associated anti-tumor activity are not yet clearly defined. The aim of this study was to explore the key events of Trichostatin A (TSA), a classic HDACI agent, against breast cancer cells.
The MCF-7, MDA-MB-231 and MCF-10A cell lines were evaluated with colony-forming and cell viability assays. Apoptosis and cell cycle distribution were detected by flow cytometry. Mitochondrial function was measured with biochemical assays, flow cytometry and transmission electron microscopy.
TSA inhibited breast cancer cell viability and proliferation, without affecting MCF-10A cell. TSA-induced breast cancer cell apoptosis was initiated by G2-M arrest and depended on mitochondrial reactive oxygen species (ROS) produced subsequent to reduced mitochondrial respiratory chain activity. The enhanced mitochondrial ROS production and apoptosis in cancer cells were markedly attenuated by antioxidants, such as N-acetyl cysteine (NAC), reduced glutathione (GSH) and Vitamin C.
The present study demonstrated that TSA-induced cell death by arresting cell cycle in G2-M phase and was dependent on production of mitochondria-derived ROS, which was derived from impaired mitochondrial respiratory chain.
PMCID: PMC3953478  PMID: 24626188
25.  Influence of stress in GaN crystals grown by HVPE on MOCVD-GaN/6H-SiC substrate 
Scientific Reports  2014;4:4179.
GaN crystals without cracks were successfully grown on a MOCVD-GaN/6H-SiC (MGS) substrate with a low V/III ratio of 20 at initial growth. With a high V/III ratio of 80 at initial growth, opaque GaN polycrystals were obtained. The structural analysis and optical characterization reveal that stress has a great influence on the growth of the epitaxial films. An atomic level model is used to explain these phenomena during crystal growth. It is found that atomic mobility is retarded by compressive stress and enhanced by tensile stress.
PMCID: PMC3935196  PMID: 24569601

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