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1.  Distinct different sensitivity of Treg and Th17 cells to Fas-mediated apoptosis signaling in patients with acute coronary syndrome 
Objective: An imbalance in CD4+CD25+ regulatory T (Treg) cells and Th17 cells has been found to correlate to occurrence of acute coronary syndrome [ACS, including unstable angina (UA) and acute myocardial infarction (AMI)]. However, the mechanisms of Th17/Treg imbalance in ACS patients are still unclear. The purpose of this study is to investigate the possibility of differences in sensitivity of Th17 and Tregs to Fas-mediated apoptosis which could lead to Th17/Treg imbalance in ACS patients. Methods: We examined the apoptosis of Th17 and Treg cells, apoptosis-related Fas/Fas ligand(FasL) pathway, and inflammatory markers in patients with AMI, UA, stable angina (SA) and controls by Flow cytometry and ELISA. Then we analysed the correlation of inflammatory markers and sFasL to Treg apoptosis, and the effect of anti-FasL antibody on Treg apoptois in vitro. Results: Our study demonstrated that apoptotic Tregs, Fas and FasL expression, Caspase-3 activity of Tregs were significantly higher in ACS patients than those in NCA and SA patients (all P < 0.05). The percentage of apoptotic Tregs is positively correlated with the levels of inflammatory markers and sFasL. In vitro incubation of peripheral blood mononuclear cells from ACS patients with anti-FasL antibody resulted in a markedly reduction of apoptotic Treg cells. However, there were no significant differences in apoptotic Th17 cells and in Fas and FasL expression for Th17 cells between the four groups (all P >0.05). Conclusions: Tregs, but not Th17 cells, become apoptotic through Fas/FasL pathway, which contributed to reduction of Tregs leading to an imbalance between Th17 and Treg cells. This could be the mechanism underlying Th17/Treg imbalance and occurrence of ACS.
PMCID: PMC3544239  PMID: 23330016
Apoptosis; Fas; Fas ligand; T helper 17; regulatory T cells; acute coronary syndrome
2.  Jagged-1 signaling suppresses the IL-6 and TGF-β treatment-induced Th17 cell differentiation via the reduction of RORγt/IL-17A/IL-17F/IL-23a/IL-12rb1 
Scientific Reports  2015;5:8234.
Jagged-1 signaling has recently been reported to be involved in the Th17 cell differentiation. However, little is known about its mechanisms. Soluble Jagged-1 was used to activate the Jagged-1–Notch signaling to interfere with the IL-6 and TGF-β-induced Th17 cell skewing. Genes relevant to the autoimmunity or inflammation were screened for the first time in this system by qPCR array for the differential expressions. The 18 genes out of 84, including Clec7a, Il12b, Il12rb1, Il12rb2, Csf3, Il15, Il17a, Il17f, Il17rc, Il17rd, Il17re, Il23a, Myd88, Socs1, Stat4, Stat5a, Sykb and Tbx21, were downregulated, but only Cxcl2, Cxcl12 and Mmp3 were upregulated. The expressions of the genes, Rorγt, Il17a, Il17f, Il12rb1 and Il23a, induced by simultaneous IL-6 and TGF-β treatment were significantly suppressed by Jagged-1, followed by the reduction of RORγt, IL-17A, and IL-17F. Consistent with the attenuation of RORγt, and the reduced production and secretion of IL-17A and IL-17F in the cell supernatant and the in situ stained cells, the number of CD4+IL-17+ cells was also diminished. It is concluded that the Jagged-1–Notch signaling can suppress the IL-6 and TGF-β treatment-induced Th17 cell skewing through the attenuation of RORγt and, hence by, the down-regulation of IL-17A, IL-17F, IL-23a, and IL-12rb1.
PMCID: PMC4316398  PMID: 25648768
3.  The clinical significance of CDK1 expression in oral squamous cell carcinoma 
Objectives: To evaluate the clinical significance of cyclin-dependent kinase 1 (CDK1) in 77 oral squamous cell carcinomas (OSCC) using immunohistochemical methods. Study Design: Immunohistochemical expression of CDK1 was compared with various clinicopathological features in 77 OSCC and 60 controlled epithelia adjacent to the tumours. In addition, correlation of CDK1 expression and prognostic and the 5-year accumulative survival rate of OSCC were investigated. Results: The CDK1 protein was expressed in 52 cases of 77 tumor tissues (67.5%), compared with 21 cases of 60 controlled (35.0%). The expression of CDK1 was significantly correlated with the histological grade of OSCC (P<0.05). The CDK1 protein was over-expressed in recurrent tumors or in those with lymph node metastasis. Statistical analysis showed a significant reduction in the 5-year accumulative survival rate in CDK1 positive cases compared with CDK1 negative cases (P<0.05). Namely, the CDK1 positive patients had poor prognosis. Conclusions: The expression of CDK1 might serve as malignant degree and prognostic markers for the survival of OSCC.
Key words:Cyclin-dependent kinase 1 (CDK1), oral squamous cell carcinoma (OSCC), immunohistochemistry, cell proliferation.
PMCID: PMC4320424  PMID: 25129248
4.  Transient inhibition of the ERK pathway prevents cerebellar developmental defects and improves long-term motor functions in murine models of neurofibromatosis type 1 
eLife  null;3:e05151.
Individuals with neurofibromatosis type 1 (NF1) frequently exhibit cognitive and motor impairments and characteristics of autism. The cerebellum plays a critical role in motor control, cognition, and social interaction, suggesting that cerebellar defects likely contribute to NF1-associated neurodevelopmental disorders. Here we show that Nf1 inactivation during early, but not late stages of cerebellar development, disrupts neuronal lamination, which is partially caused by overproduction of glia and subsequent disruption of the Bergmann glia (BG) scaffold. Specific Nf1 inactivation in glutamatergic neuronal precursors causes premature differentiation of granule cell (GC) precursors and ectopic production of unipolar brush cells (UBCs), indirectly disrupting neuronal migration. Transient MEK inhibition during a neonatal window prevents cerebellar developmental defects and improves long-term motor performance of Nf1-deficient mice. This study reveals essential roles of Nf1 in GC/UBC migration by generating correct numbers of glia and controlling GC/UBC fate-specification/differentiation, identifying a therapeutic prevention strategy for multiple NF1-associcated developmental abnormalities.
eLife digest
Neurofibromatosis type 1 is a condition characterized by the growth of tumors along the nerves of the body. It is caused by mutations in a gene called NF1, which codes for a protein that normally works to inhibit the activity of another protein called Ras. In healthy cells, Ras is needed to stimulate the cells to grow and divide. However, if the Ras protein is not turned off at the right time or if it is activated at the wrong time, it can force cells to keep growing and dividing; this leads to the growth of tumors.
Along with being prone to developing cancer, individuals with neurofibromatosis type 1 also develop a range of neurodevelopmental disorders that alter their learning, motor skills and social interactions. Some also exhibit behaviors that are associated with autism. This led Kim, Wang et al. to investigate whether a region of the brain—called the cerebellum—that has recently been associated with autism is also affected in a mouse model of neurofibromatosis type 1.
The cerebellum is best known for its role in coordinating movement, although it also has functions in cognition, behavior and other processes. Ras is involved in the development of the cerebellum; and so Kim, Wang et al. asked whether the loss of the Nf1 gene from cells in the mouse cerebellum might cause the neurodevelopmental defects associated with neurofibromatosis type 1.
Loss of Nf1 during early (but not in late) development of the cerebellum disrupted the normal organization of the nerve cells (or neurons) into specific cell layers. These defects were caused, in part, by the over-growth of a type of supporting cell—called glia cells—at a specific developmental stage—that would normally form a scaffold to help neurons migrate to their correct position. Nf1 also controls the generation of the correct types of neurons in the right time and at right location during the early development of the cerebellum.
Next, Kim, Wang et al. treated newborn mice with a compound that inhibits Ras signaling via their mother's milk for 3 weeks. In mice with an inactive Nf1 gene, the treatment helped to prevent some defects in the cerebellum and the mice had improved motor coordination several months later. Whether this could form the basis of a preventative treatment for neurodevelopmental disorders associated with neurofibromatosis type 1 in humans remains a question for future work.
PMCID: PMC4297949  PMID: 25535838
neurofibromatosis type 1; cerebellum; bergmann glial cells; granule cells; unipolar brush cells; tumor suppressor gene; mouse
5.  Structural basis for a hand-like site in the calcium sensor CatchER with fast kinetics 
High-resolution crystal structures of the designed calcium sensor CatchER revealed snapshots of calcium and gadolinium ions binding within the designed site in agreement with its fast kinetics.
Calcium ions, which are important signaling molecules, can be detected in the endoplasmic reticulum by an engineered mutant of green fluorescent protein (GFP) designated CatchER with a fast off-rate. High resolution (1.78–1.20 Å) crystal structures were analyzed for CatchER in the apo form and in complexes with calcium or gadolinium to probe the binding site for metal ions. While CatchER exhibits a 1:1 binding stoichiometry in solution, two positions were observed for each of the metal ions bound within the hand-like site formed by the carboxylate side chains of the mutated residues S147E, S202D, Q204E, F223E and T225E that may be responsible for its fast kinetic properties. Comparison of the structures of CatchER, wild-type GFP and enhanced GFP confirmed that different conformations of Thr203 and Glu222 are associated with the two forms of Tyr66 of the chromophore which are responsible for the absorbance wavelengths of the different proteins. Calcium binding to CatchER may shift the equilibrium for conformational population of the Glu222 side chain and lead to further changes in its optical properties.
PMCID: PMC3852649  PMID: 24311573
calcium sensors; green fluorescent protein; metal-binding sites in proteins
6.  Axial Plane Optical Microscopy 
Scientific Reports  2014;4:7253.
We present axial plane optical microscopy (APOM) that can, in contrast to conventional microscopy, directly image a sample's cross-section parallel to the optical axis of an objective lens without scanning. APOM combined with conventional microscopy simultaneously provides two orthogonal images of a 3D sample. More importantly, APOM uses only a single lens near the sample to achieve selective-plane illumination microscopy, as we demonstrated by three-dimensional (3D) imaging of fluorescent pollens and brain slices. This technique allows fast, high-contrast, and convenient 3D imaging of structures that are hundreds of microns beneath the surfaces of large biological tissues.
PMCID: PMC4248283  PMID: 25434770
7.  Isolation and epithelial co-culture of mouse renal peritubular endothelial cells 
BMC Cell Biology  2014;15(1):40.
Endothelial-mesenchymal transition (EndoMT) has been shown to be a major source of myofibroblasts, contributing to kidney fibrosis. However, in vitro study of endothelial cells often relies on culture of isolated primary endothelial cells due to the unavailability of endothelial cell lines. Our recent study suggested that peritubular endothelial cells could contribute to kidney fibrosis through EndoMT. Therefore, successful isolation and culture of mouse peritubular endothelial cells could provide a new platform for studying kidney fibrosis. This study describes an immunomagnetic separation method for the isolation of mouse renal peritubular endothelial cells using anti-CD146 MicroBeads, followed by co-culture with mouse renal proximal tubular epithelial cells to maintain endothelial phenotype.
Flow cytometry showed that after isolation and two days of culture, about 95% of cells were positive for endothelial-specific marker CD146. The percentage of other cells, including dendritic cells (CD11c) and macrophages (F4/80), was less than 1%. Maintenance of endothelial cell phenotype required vascular endothelial growth factor (VEGF) and co-culture with mouse proximal tubular epithelial cells.
In this study, we established a method for the isolation of mouse renal peritubular endothelial cells by using immunomagnetic separation with anti-CD146 MicroBeads, followed by co-culture with mouse renal proximal tubular epithelial cells to maintain phenotype.
Electronic supplementary material
The online version of this article (doi:10.1186/s12860-014-0040-6) contains supplementary material, which is available to authorized users.
PMCID: PMC4260259  PMID: 25433516
Peritubular endothelial cells; Tubular epithelial cells; CD146; Co-culture; Vascular endothelial growth factor
8.  Estimating rice chlorophyll content and leaf nitrogen concentration with a digital still color camera under natural light 
Plant Methods  2014;10(1):36.
The color of crop leaves is closely correlated with nitrogen (N) status and can be quantified easily with a digital still color camera and image processing software. The establishment of the relationship between image color indices and N status under natural light is important for crop monitoring and N diagnosis in the field. In our study, a digital still color camera was used to take pictures of the canopies of 6 rice (Oryza sativa L.) cultivars with N treatments ranging from 0 to 315 kg N ha-1 in the field under sunny and overcast conditions in 2010 and 2011, respectively.
Significant correlations were observed between SPAD readings, leaf N concentration (LNC) and 13 image color indices calculated from digital camera images using three color models: RGB, widely used additive color model; HSV, a cylindrical-coordinate similar to the human perception of colors; and the L*a*b* system of the International Commission on Illumination. Among these color indices, the index b*, which represents the visual perception of yellow-blue chroma, has the closest linear relationship with SPAD reading and LNC. However, the relationships between LNC and color indices were affected by the developmental phase. Linear regression models were used to predict LNC and SPAD from color indices and phasic development. After that, the models were validated with independent data. Generally, acceptable performance and prediction were found between the color index b*, SPAD reading and LNC with different cultivars and sampling dates under different natural light conditions.
Our study showed that digital color image analysis could be a simple method of assessing rice N status under natural light conditions for different cultivars and different developmental stages.
Electronic supplementary material
The online version of this article (doi:10.1186/1746-4811-10-36) contains supplementary material, which is available to authorized users.
PMCID: PMC4236477  PMID: 25411579
Digital still color camera; Leaf color; Image processing technology; Natural light; Nitrogen; Rice
9.  PRDI-BF1-RIZ domain of retinoblastoma protein-interacting zinc finger gene 1 induces apoptosis and exerts anticancer activity in esophageal squamous cell carcinoma cells 
Oncology Letters  2014;9(1):341-346.
The present study examined the role of the PRDI-BF1-RIZ (PR) domain of tumor suppressor retinoblastoma protein-interacting zinc finger gene 1 (RIZ1) as an anticancer domain and its ability to induce apoptosis in esophageal squamous cell carcinoma (ESCC) cells. The TE13 ESCC cell line was transfected with pcDNA3.1(+) eukaryotic expression vectors bearing the open reading frames of either the human RIZ1 gene or the PR domain, and the mRNA and protein expression levels were then detected using quantitative reverse transcription polymerase chain reaction and western blotting, respectively. The rate of apoptosis was determined by flow cytometry and the cell invasion ability was determined by an invasion assay. RIZ1 and the PR domain induced apoptosis and reduced the cell invasion ability (P<0.01). These findings indicate that the RIZ1 gene possesses anticancer activity in the PR domain, which may be important in inhibiting the development of ESCC.
PMCID: PMC4246629  PMID: 25435989
retinoblastoma protein-interacting zinc finger gene 1; PRDI-BF1-RIZ domain; esophageal squamous cell carcinoma
10.  Melatonin alleviates myosin light chain kinase expression and activity via the mitogen-activated protein kinase pathway during atherosclerosis in rabbits 
Molecular Medicine Reports  2014;11(1):99-104.
Melatonin (MLT) is an endogenous indole compound with numerous biological activities that has been associated with atherosclerosis (AS). In the present study, rabbits were used as an AS model in order to investigate whether MLT affects endothelial cell permeability, myosin light chain kinase (MLCK) activity and MLCK expression via the mitogen-activated protein kinase (MAPK) pathway. Expression and activity of MLCK were measured using western blot analysis, quantitative polymerase chain reaction, immunohistochemistry and γ-32P-adenosine triphosphate incorporation. Endothelial permeability was detected using rhodamine phalloidin fluorescence staining. The phosphorylation of extracellular regulated protein kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 in endothelial cells were also analyzed using western blot analysis. Atheromatous plaques were formed in rabbits with a high cholesterol diet; however, following treatment with MLT, the number and areas of atheromatous plaques were significantly reduced. In addition, MLT treatment reversed the increase of MLCK activity and expression that occurred in rabbits with high cholesterol intake. Furthermore, levels of phosphorylated ERK, JNK and p38 decreased following MLT treatment. In conclusion, the results of the present study indicated that AS may be associated with increased MLCK expression and activity, which was reduced following treatment with MLT. The mechanism of action of MLT was thought to proceed via modulating MAPK pathway signal transduction; however, further studies are required in order to fully elucidate the exact regulatory mechanisms involved.
PMCID: PMC4237093  PMID: 25339116
melatonin; permeability; myosin light chain kinase; atherosclerosis; mitogen-activated protein kinase
11.  Glaucoma, Alzheimer's Disease, and Parkinson's Disease: An 8-Year Population-Based Follow-Up Study 
PLoS ONE  2014;9(10):e108938.
Glaucoma is the leading cause of irreversible blindness worldwide and primary open-angle glaucoma (POAG) is the most common type of glaucoma. An association between POAG and the subsequent risk of Alzheimer's disease (AD) and Parkinson's disease (PD) was unclear.
To investigate the association between POAG (including normal-tension glaucoma) and the subsequent risk of AD or PD 8 years following a diagnosis of POAG.
We performed a retrospective, propensity-score-matched analysis of a population-based cohort consisting of patients with and without POAG aged 60 years and older. Control patients without POAG were propensity-score matched to POAG patients based on their baseline characteristics.
The incidence rates and confidence intervals (CIs) of AD among the patients with and without POAG were 2.85 (95% CI: 2.19–3.70) and 1.98 (95% CI: 1.68–2.31) per 1000 person-years, respectively. The incidence rates of PD among the POAG and non-POAG cohorts were 4.36 (95% CI: 3.52–5.39) and 4.37 (95% CI: 3.92–4.86) per 1000 person-years, respectively. Kaplan-Meier failure curves showed that the POAG patients had a higher risk of AD than the control patients did (log-rank test, P = .0189). However, the cumulative PD hazard ratios for the POAG and non-POAG patients did not differ significantly (log-rank test, P = .9953).
In elderly patients, POAG is a significant predictor of AD, but POAG is not a predictor of PD.
PMCID: PMC4183534  PMID: 25275530
12.  Drinking Patterns and Alcohol Use Disorders in São Paulo, Brazil: The Role of Neighborhood Social Deprivation and Socioeconomic Status 
PLoS ONE  2014;9(10):e108355.
Research conducted in high-income countries has investigated influences of socioeconomic inequalities on drinking outcomes such as alcohol use disorders (AUD), however, associations between area-level neighborhood social deprivation (NSD) and individual socioeconomic status with these outcomes have not been explored in Brazil. Thus, we investigated the role of these factors on drink-related outcomes in a Brazilian population, attending to male-female variations.
A multi-stage area probability sample of adult household residents in the São Paulo Metropolitan Area was assessed using the WHO Composite International Diagnostic Interview (WMH-CIDI) (n = 5,037). Estimation focused on prevalence and correlates of past-year alcohol disturbances [heavy drinking of lower frequency (HDLF), heavy drinking of higher frequency (HDHF), abuse, dependence, and DMS-5 AUD] among regular users (RU); odds ratio (OR) were obtained.
Higher NSD, measured as an area-level variable with individual level variables held constant, showed an excess odds for most alcohol disturbances analyzed. Prevalence estimates for HDLF and HDHF among RU were 9% and 20%, respectively, with excess odds in higher NSD areas; schooling (inverse association) and low income were associated with male HDLF. The only individual-level association with female HDLF involved employment status. Prevalence estimates for abuse, dependence, and DSM-5 AUD among RU were 8%, 4%, and 8%, respectively, with excess odds of: dependence in higher NSD areas for males; abuse and AUD for females. Among RU, AUD was associated with unemployment, and low education with dependence and AUD.
Regular alcohol users with alcohol-related disturbances are more likely to be found where area-level neighborhood characteristics reflect social disadvantage. Although we cannot draw inferences about causal influence, the associations are strong enough to warrant future longitudinal alcohol studies to explore causal mechanisms related to the heterogeneous patterns of association and male-female variations observed herein. Hopefully, these findings may help guide future directions for public health.
PMCID: PMC4182710  PMID: 25272008
13.  Highly Potent HIV-1 Protease Inhibitors with Novel Tricyclic P2-ligands: Design, Synthesis, and Protein-ligand X-Ray Studies 
Journal of medicinal chemistry  2013;56(17):6792-6802.
The design, synthesis, and biological evaluation of a series of HIV-1 protease inhibitors incorporating stereochemically defined fused tricyclic P2-ligands are described. Various substituent effects were investigated in order to maximize the ligand-binding site interactions in the protease active site. Inhibitors 16a and 16f showed excellent enzyme inhibitory and antiviral activity while incorporation of sulfone functionality resulted in a decrease in potency. Both inhibitors 16a and 16f have maintained activity against a panel of multidrug resistant HIV-1 variants. A high-resolution X-ray crystal structure of 16a-bound HIV-1 protease revealed important molecular insights into the ligand-binding site interactions which may account for the inhibitor’s potent antiviral activity and excellent resistance profiles.
PMCID: PMC3800042  PMID: 23947685
14.  Hepatitis B virus X protein accelerates the development of hepatoma 
Cancer Biology & Medicine  2014;11(3):182-190.
The chronic infection of hepatitis B virus (HBV) is closely related to the occurrence and development of hepatocellular carcinoma (HCC). Accumulated evidence has shown that HBV X protein (HBx protein) is a multifunctional regulator with a crucial role in hepatocarcinogenesis. However, information on the mechanism by which HBV induces HCC is lacking. This review focuses on the pathological functions of HBx in HBV-induced hepatocarcinogenesis. As a transactivator, HBx can modulate nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and transcription factor AP-2. Moreover, HBx can affect regulatory non-coding RNAs (ncRNAs) including microRNAs and long ncRNAs (lncRNAs), such as miRNA-205 and highly upregulated in liver cancer (HULC), respectively. HBx is also involved in epigenetic modification, including methylation and acetylation. HBx interacts with various signal-transduction pathways, such as protein kinase B/Akt, Wnt/β-catenin, signal transducer and activator of transcription, and NF-κB pathways. Moreover, HBx affects cellular fate by shifting the balance toward cell survival. HBx may lead to the loss of apoptotic functions or directly contributes to oncogenesis by achieving transforming functions, which induce hepatocarcinogenesis. Additionally, HBx can modulate apoptosis and immune response by direct or indirect interaction with host factors. We conclude that HBx hastens the development of hepatoma.
PMCID: PMC4197427  PMID: 25364579
Hepatocellular carcinoma (HCC); hepatitis B virus (HBV); HBV X protein (HBx protein); hepatocarcinogenesis
15.  Medicinal plant activity on Helicobacter pylori related diseases 
World Journal of Gastroenterology : WJG  2014;20(30):10368-10382.
More than 50% of the world population is infected with Helicobacter pylori (H. pylori). The bacterium highly links to peptic ulcer diseases and duodenal ulcer, which was classified as a group I carcinogen in 1994 by the WHO. The pathogenesis of H. pylori is contributed by its virulence factors including urease, flagella, vacuolating cytotoxin A (VacA), cytotoxin-associated gene antigen (Cag A), and others. Of those virulence factors, VacA and CagA play the key roles. Infection with H. pylori vacA-positive strains can lead to vacuolation and apoptosis, whereas infection with cagA-positive strains might result in severe gastric inflammation and gastric cancer. Numerous medicinal plants have been reported for their anti-H. pylori activity, and the relevant active compounds including polyphenols, flavonoids, quinones, coumarins, terpenoids, and alkaloids have been studied. The anti-H. pylori action mechanisms, including inhibition of enzymatic (urease, DNA gyrase, dihydrofolate reductase, N-acetyltransferase, and myeloperoxidase) and adhesive activities, high redox potential, and hydrophilic/hydrophobic natures of compounds, have also been discussed in detail. H. pylori-induced gastric inflammation may progress to superficial gastritis, atrophic gastritis, and finally gastric cancer. Many natural products have anti-H. pylori-induced inflammation activity and the relevant mechanisms include suppression of nuclear factor-κB and mitogen-activated protein kinase pathway activation and inhibition of oxidative stress. Anti-H. pylori induced gastric inflammatory effects of plant products, including quercetin, apigenin, carotenoids-rich algae, tea product, garlic extract, apple peel polyphenol, and finger-root extract, have been documented. In conclusion, many medicinal plant products possess anti-H. pylori activity as well as an anti-H. pylori-induced gastric inflammatory effect. Those plant products have showed great potential as pharmaceutical candidates for H. pylori eradication and H. pylori induced related gastric disease prevention.
PMCID: PMC4130844  PMID: 25132753
Helicobacter pylori; Virulence factor; Medicinal plant; Active compound; Mechanism; Inflammation; Gastric cancer; Nuclear factor-κB pathway
16.  Transcriptional Repression by the BRG1-SWI/SNF Complex Affects the Pluripotency of Human Embryonic Stem Cells 
Stem Cell Reports  2014;3(3):460-474.
The SWI/SNF complex plays an important role in mouse embryonic stem cells (mESCs), but it remains to be determined whether this complex is required for the pluripotency of human ESCs (hESCs). Using RNAi, we demonstrated that depletion of BRG1, the catalytic subunit of the SWI/SNF complex, led to impaired self-renewing ability and dysregulated lineage specification of hESCs. A unique composition of the BRG1-SWI/SNF complex in hESCs was further defined by the presence of BRG1, BAF250A, BAF170, BAF155, BAF53A, and BAF47. Genome-wide expression analyses revealed that BRG1 participated in a broad range of biological processes in hESCs through pathways different from those in mESCs. In addition, chromatin immunoprecipitation sequencing (ChIP-seq) demonstrated that BRG1 played a repressive role in transcriptional regulation by modulating the acetylation levels of H3K27 at the enhancers of lineage-specific genes. Our data thus provide valuable insights into molecular mechanisms by which transcriptional repression affects the self-renewal and differentiation of hESCs.
•We report a conserved but distinct role of SWI/SNF complex in hESC pluripotency•Depletion of BAF170 in SWI/SNF complex leads to impaired pluripotency of hESCs•BRG1 negatively regulates transcription of lineage-specific genes•BRG1 downregulates H3K27ac levels at enhancers of lineage-specific genes
In this article, Wang and colleagues show that a unique composition of the BRG1-SWI/SNF complex is required for maintaining self-renewal and proper differentiation of human embryonic stem cells. In addition, they demonstrate that BRG1 participates in a broad range of biological processes in human stem cells through transcriptional repression via downregulation of the acetylation levels of H3K27 at enhancers of lineage-specific genes.
PMCID: PMC4266000  PMID: 25241744
17.  A Novel Role of CDX1 in Embryonic Epicardial Development 
PLoS ONE  2014;9(7):e103271.
The molecular mechanism that regulates epicardial development has yet to be understood. In this study, we explored the function of CDX1, a Caudal-related family member, in epicardial epithelial-to-mesenchymal transition (EMT) and in the migration and the differentiation of epicardium-derived progenitors into vascular smooth muscle cells. We detected a transient expression of CDX1 in murine embryonic hearts at 11.5 days post coitum (dpc). Using a doxycycline-inducible CDX1 mouse model, primary epicardium, and ex vivo heart culture, we further demonstrated that ectopic expression of CDX1 promoted epicardial EMT. In addition, a low-dose CDX1 induction led to enhanced migration and differentiation of epicardium-derived cells into α-SMA+ vascular smooth muscles. In contrast, either continued high-level induction of CDX1 or CDX1 deficiency attenuated the ability of epicardium-derived cells to migrate and to mature into smooth muscles induced by TGF-β1. Further RNA-seq analyses showed that CDX1 induction altered the transcript levels of genes involved in neuronal development, angiogenesis, and cell adhesions required for EMT. Our data have revealed a previously undefined role of CDX1 during epicardial development, and suggest that transient expression of CDX1 promotes epicardial EMT, whereas subsequent down-regulation of CDX1 after 11.5 dpc in mice is necessary for further subepicardial invasion of EPDCs and contribution to coronary vascular endothelium or smooth muscle cells.
PMCID: PMC4113346  PMID: 25068460
18.  Melatonin Inhibits the Migration of Human Lung Adenocarcinoma A549 Cell Lines Involving JNK/MAPK Pathway 
PLoS ONE  2014;9(7):e101132.
Melatonin, an indolamine produced and secreted predominately by the pineal gland, exhibits a variety of physiological functions, possesses antioxidant and antitumor properties. But, the mechanisms for the anti-cancer effects are unknown. The present study explored the effects of melatonin on the migration of human lung adenocarcinoma A549 cells and its mechanism.
MTT assay was employed to measure the viability of A549 cells treated with different concentrations of melatonin. The effect of melatonin on the migration of A549 cells was analyzed by wound healing assay. Occludin location was observed by immunofluorescence. The expression of occludin, osteopontin (OPN), myosin light chain kinase (MLCK) and phosphorylation of myosin light chain (MLC), JNK were detected by western blots.
After A549 cells were treated with melatonin, the viability and migration of the cells were inhibited significantly. The relative migration rate of A549 cells treated with melatonin was only about 20% at 24 h. The expression level of OPN, MLCK and phosphorylation of MLC of A549 cells were reduced, while the expression of occludin was conversely elevated, and occludin located on the cell surface was obviously increased. The phosphorylation status of JNK in A549 cells was also reduced when cells were treated by melatonin.
Melatonin significantly inhibits the migration of A549 cells, and this may be associated with the down-regulation of the expression of OPN, MLCK, phosphorylation of MLC, and up-regulation of the expression of occludin involving JNK/MAPK pathway.
PMCID: PMC4084631  PMID: 24992189
19.  Genetic variants in DNA repair pathway genes and risk of esophageal squamous cell carcinoma and gastric adenocarcinoma in a Chinese population 
Carcinogenesis  2013;34(7):1536-1542.
The DNA repair pathways help to maintain genomic integrity and therefore genetic variation in the pathways could affect the propensity to develop cancer. Selected germline single nucleotide polymorphisms (SNPs) in the pathways have been associated with esophageal cancer and gastric cancer (GC) but few studies have comprehensively examined the pathway genes. We aimed to investigate associations between DNA repair pathway genes and risk of esophageal squamous cell carcinoma (ESCC) and GC, using data from a genome-wide association study in a Han Chinese population where ESCC and GC are the predominant cancers. In sum, 1942 ESCC cases, 1758 GC cases and 2111 controls from the Shanxi Upper Gastrointestinal Cancer Genetics Project (discovery set) and the Linxian Nutrition Intervention Trials (replication set) were genotyped for 1675 SNPs in 170 DNA repair-related genes. Logistic regression models were applied to evaluate SNP-level associations. Gene- and pathway-level associations were determined using the resampling-based adaptive rank-truncated product approach. The DNA repair pathways overall were significantly associated with risk of ESCC (P = 6.37 × 10− 4), but not with GC (P = 0.20). The most significant gene in ESCC was CHEK2 (P = 2.00 × 10− 6) and in GC was CLK2 (P = 3.02 × 10− 4). We observed several other genes significantly associated with either ESCC (SMUG1, TDG, TP53, GTF2H3, FEN1, POLQ, HEL308, RAD54B, MPG, FANCE and BRCA1) or GC risk (MRE11A, RAD54L and POLE) (P < 0.05). We provide evidence for an association between specific genes in the DNA repair pathways and the risk of ESCC and GC. Further studies are warranted to validate these associations and to investigate underlying mechanisms.
PMCID: PMC3697889  PMID: 23504502
20.  The Ron receptor tyrosine kinase activates c-Abl to promote cell proliferation through tyrosine phosphorylation of PCNA in breast cancer 
Oncogene  2013;33(11):1429-1437.
Multiple growth pathways lead to enhanced proliferation in malignant cells. However, how the core machinery of DNA replication is regulated by growth signaling remains largely unclear. The sliding clamp PCNA (Proliferating Cell Nuclear Antigen) is an indispensable component of the DNA machinery responsible for replicating the genome and maintaining genomic integrity. We previously reported that epidermal growth factor receptor (EGFR) triggered tyrosine 211 (Y211) phosphorylation of PCNA, which in turn stabilized PCNA on chromatin to promote cell proliferation. Here we show that the phosphorylation can also be catalyzed by the non-receptor tyrosine kinase c-Abl. We further demonstrate that, in the absence of EGFR, signaling to PCNA can be attained through the activation of the Ron receptor tyrosine kinase and the downstream non-receptor tyrosine kinase c-Abl. We show that Ron and c-Abl form a complex, and that activation of Ron by its ligand, HGFL, stimulates c-Abl kinase activity, which in turn directly phosphorylates PCNA at Y211 and leads to an increased level of chromatin-associated PCNA. Correspondingly, HGFL-induced Ron activation resulted in Y211 phosphorylation of PCNA while silencing of c-Abl blocked this effect. We show that cAbl and Y211 phosphorylation of PCNA is an important axis downstream of Ron, which is required for cell proliferation. Treatment with a specific peptide which inhibits Y211 phosphorylation of PCNA or with the c-Abl pharmacological inhibitor imatinib suppressed HGFL-induced cell proliferation. Our findings identify the pathway of Ron-cAbl-PCNA as a mechanism of oncogene-induced cell proliferation, with potentially important implications for development of combination therapy of breast cancer.
PMCID: PMC4064789  PMID: 23542172
PCNA; Ron; receptor tyrosine kinase; tyrosine phosphorylation; Y211; tyrosine kinase; c-Abl
21.  Spatial patterns of the congenital heart disease prevalence among 0- to 14-year-old children in Sichuan Basin, P. R China, from 2004 to 2009 
BMC Public Health  2014;14:595.
Congenital heart disease (CHD) is the most common type of major birth defects in Sichuan, the most populous province in China. The detailed etiology of CHD is unknown but some environmental factors are suspected as the cause of this disease. However, the geographical variations in CHD prevalence would be highly valuable in providing a clue on the role of the environment in CHD etiology. Here, we investigate the spatial patterns and geographic differences in CHD prevalence among 0- to 14-year-old children, discuss the possible environmental risk factors that might be associated with CHD prevalence in Sichuan Basin from 2004 to 2009.
The hierarchical Bayesian model was used to estimate CHD prevalence at the township level. Spatial autocorrelation statistics were performed, and a hot-spot analysis with different distance thresholds was used to identify the spatial pattern of CHD prevalence. Distribution and clustering maps were drawn using geographic information system tools.
CHD prevalence was significantly clustered in Sichuan Basin in different spatial scale. Typical hot/cold clusters were identified, and possible CHD causes were discussed. The association between selected hypothetical environmental factors of maternal exposure and CHD prevalence was evaluated.
The largest hot-spot clustering phenomena and the CHD prevalence clustering trend among 0- to 14-year-old children in the study area showed a plausibly close similarity with those observed in the Tuojiang River Basin. The high ecological risk of heavy metal(Cd, As, and Pb)sediments in the middle and lower streams of the Tuojiang River watershed and ammonia–nitrogen pollution may have contribution to the high prevalence of CHD in this area.
PMCID: PMC4073187  PMID: 24924350
Congenital heart disease(CHD); Hierarchical Bayesian model(HB); Spatial autocorrelation; Hot-spot analysis; Sichuan Basin
22.  Attitude and Impact of Perceived Depression in the Workplace 
Information concerning the occurrence and consequences of depression in the workplace is scarce. This study estimates how workers perceive depression, to investigate depression-related disabilities, and management of depression in the workplace. This investigation is based on a cross-sectional web-based survey of 1,000 workers recruited from online sources. The participants were Brazilian workers, aged 16–64 years, current workers and managers, or who have worked within the past year. Subjects answered a 13-item questionnaire about depression, its related consequences in the workplace, and available resources to handle depression. Common symptoms attributable to depression were crying, loss of interest, and sadness. Almost one in five participants reported having ever been labeled by a doctor/medical professional as suffering from depression. However, the majority of ever-depressed workers (73.5%) remained working. Performance-related impairments were reported by around 60% of depressed workers who continued working. Over half of them also complained about cognitive symptoms (concentration difficulties, indecisiveness, forgetfulness). One in three workers had taken off work due to depression (mean 65.7 out-of-role days), with these periods being lengthier for men than women. Managers underestimated the number of days out-of-role (29.5 days). The findings suggested that identification and management of symptoms of depression should be set as a priority in worker’s health care.
PMCID: PMC4078563  PMID: 24914639
depression; workplace; cognitive symptoms; productivity
23.  Extreme multidrug resistant HIV-1 protease with 20 mutations is resistant to novel protease inhibitors with P1′-pyrrolidinone or P2-tris-tetrahydrofuran 
Journal of medicinal chemistry  2013;56(10):4017-4027.
Extreme drug resistant mutant of HIV-1 protease (PR) bearing 20 mutations (PR20) has been studied with the clinical inhibitor amprenavir (1) and two potent antiviral investigational inhibitors GRL-02031 (2) and GRL-0519 (3). Clinical inhibitors are >1000-fold less active on PR20 than on wild type enzyme, which is consistent with dissociation constants (KL) from isothermal titration calorimetry of 40 nM for 3, 178 nM for amprenavir, and 960 nM for 2. High resolution crystal structures of PR20-inhibitor complexes revealed altered interactions compared with the corresponding wild-type PR complexes in agreement with relative inhibition. Amprenavir lacks interactions due to PR20 mutations in the S2/S2′ subsites relative to PR. Inhibitors 2 and 3 lose interactions with Arg8′ in PR20 relative to the wild type enzyme since Arg8′ shifts to interact with mutated L10F side chain. Overall, inhibitor 3 compares favorably with darunavir in affinity for PR20 and shows promise for further development.
PMCID: PMC3719844  PMID: 23590295
HIV/AIDS; aspartic protease; X-ray crystallography; drug resistance
24.  Effect of Chicken Egg Yolk Antibodies (IgY) against Diarrhea in Domesticated Animals: A Systematic Review and Meta-Analysis 
PLoS ONE  2014;9(5):e97716.
IgY antibodies are serum immunoglobulin in birds, reptiles and amphibians, and are transferred from serum to egg yolk to confer passive immunity to their embryos and offspring. Currently, the oral passive immunization using chicken IgY has been focused as an alternative to antibiotics for the treatment and control of diarrhea in animals and humans. This systematic review was focused to determine the effect of IgY in controlling and preventing diarrhea in domesticated animals including Piglets, Mice, Poultry and Calves.
Methods and Results
Previous research reports focused on treatment effect of Chicken IgY against diarrhea were retrieved from different electronic data bases (MEDLINE, EMBASE, SPRINGER-LINK, WILEY, AGRICOLA, MEDWELL Journals, Scientific Publish, Chinese articles from Core periodicals in 2012). A total of 61 studies in 4 different animal classes met the inclusion criteria. Data on study characteristics and outcome measures were extracted. The pooled relative risk (RR) of 49 studies of different animals [Piglets – 22; Mice – 14; Poultry – 7 and Calves – 6] in meta-analyses revealed that, IgY significantly reduced the risk of diarrhea in treatment group when compare to the placebo. However, the 95% confidence intervals of the majority of studies in animal class piglets and calves embrace RR of one. The same results were obtained in sub group analyses (treatment regiment – prophylactic or therapeutic; pathogen type – bacterial or viral). Perhaps, this inconsistency in the effect of IgY at the individual study level and overall effect measures could be influenced by the methodological heterogeneity.
The present systematic review (SR) and meta-analysis demonstrated the beneficial effect of IgY. This supports the opinion that IgY is useful for prophylaxis and treatment. However, more intensive studies using the gold standard animal experiments with the focus to use IgY alone or in combination with other alternative strategies are indispensable.
PMCID: PMC4028221  PMID: 24846286
25.  A Randomized Trial of Chinese Diaoshi Jifa on Treatment of Dizziness in Meniere's Disease 
Background. Meniere's disease is characterized by refractory dizziness and hearing disturbance. We aimed to investigate the efficacy and tolerance of Diaoshi Jifa, a Chinese hand skill for treating dizziness in Meniere's disease. Methods. An open-labeled, randomized, controlled intervention trial was conducted. Twenty-seven patients diagnosed with Meniere's disease were randomly allocated to control group or experimental group. Both groups were assessed by DHI (dizziness handicap inventory (DHI)) questionnaire score before and within 24 hours of receiving treatment, respectively. Results. Twenty-six participants completed the study, and no adverse event was reported due to Diaoshi Jifa treatment. The difference in the DHI scores between baseline and posttreatment reached significant difference in both groups (63.88 ± 19.94 versus 10.25 ± 9.77 and 54.36 ± 17.97 versus 49.6 ± 20.50). Significant difference in DHI scores was observed between the two groups after treatment (10.25 ± 9.77 versus 49.6 ± 20.50). Further investigation of DHI subscales in the experimental group revealed significant improvement posttreatment in the physical domain, functional domain, and emotional domain. Although higher rate of improvement in the emotional domain compared to physical or functional domains was found, the difference was not statistically significant. Conclusions. Diaoshi Jifa might be a fast, effective, and well-tolerated method for alleviating dizziness in Meniere's disease.
PMCID: PMC4052476  PMID: 24955104

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