Sca-1 (Stem Cell Antigen-1) is a member of the Ly-6 family proteins that functions in cell growth, differentiation, and self-renewal in multiple tissues. In skeletal muscle Sca-1 negatively regulates myoblast proliferation and differentiation, and may function in the maintenance of progenitor cells. We investigated the role of Sca-1 in skeletal muscle regeneration and show here that Sca-1 expression is upregulated in a subset of myogenic cells upon muscle injury. We demonstrate that extract from crushed muscle upregulates Sca-1 expression in myoblasts in vitro, and that this effect is reversible and independent of cell proliferation. Sca-1(-/-) mice exhibit defects in muscle regeneration, with the development of fibrosis following injury. Sca-1(-/-) muscle displays reduced activity of matrix metalloproteinases, critical regulators of extracellular matrix remodeling. Interestingly, we show that the number of satellite cells is similar in wild-type and Sca-1(-/-) muscle, suggesting that in satellite cells Sca-1 does not play a role in self-renewal. We hypothesize that Sca-1 upregulates, directly or indirectly, the activity of matrix metalloproteinases, leading to matrix breakdown and efficient muscle regeneration. Further elucidation of the role of Sca-1 in matrix remodeling may aid in the development of novel therapeutic strategies for the treatment of fibrotic diseases.

Uncontrolled fibrosis of skin and internal organs is the main characteristic of scleroderma, and collagen is a major extracellular matrix protein that deposits in the fibrotic organs. As the chaperone of collagen, heat shock protein 47 (HSP47) is closely related with the development of fibrosis. To explore the potential function of HSP47 in the pathogenesis of scleroderma, the clinical, in vivo and in vitro studies were performed. In clinical, the increased mRNA level of HSP47 was observed in the skin fibroblasts and PBMC from scleroderma patients, and the enhanced protein level of HSP47 was also detected in the skin biopsy and plasma of the above patients. Unexpectedly, the enhanced levels of HSP47 were positively correlated with the presence of anti-centromere antibody in scleroderma patients. Moreover, a high expression of HSP47 was found in the skin lesion of BLM-induced scleroderma mouse model. Further in vitro studies demonstrated that HSP47 knockdown could block the intracellular and extracellular collagen over-productions induced by exogenous TGF-β. Therefore, the results in this study provide direct evidence that HSP47 is involved in the pathogenesis of scleroderma. The high expression of HSP47 can be detected in the circulatory system of scleroderma patients, indicating that HSP47 may become a pathological marker to assess the progression of scleroderma, and also explain the systemic fibrosis of scleroderma. Meanwhile, collagen over-expression is blocked by HSP47 knockdown, suggesting the possibility that HSP47 can be a potential therapeutic target for scleroderma.

Persistent fibroblast activation underlies skin fibrosis in systemic sclerosis (SSc), but the transcriptional and epigenetic mechanisms controlling this process are not well understood. In view of the potent influence of acetylation status governing tissue fibrosis, we undertook this study to investigate the expression of the antiaging deacetylase enzyme sirtuin 1 (SIRT1) in SSc and its effects on fibrotic responses in vitro and in vivo.

Literature suggests that genetic variants associated with increased susceptibility to gastric cancer (GCa) are mostly located in genes involved in carcinogenesis and possibly tumor progression. Therefore, we hypothesize that high genetic susceptibility is also associated with prognosis of the patients. To test this hypothesis, we selected a total of 42 common genetic variants that were reportedly associated with GCa risk with a high level of evidence obtained from either genome-wide association studies (GWASs) or meta-analyses and performed survival analysis of patients used in a case-control analysis. We first used 1115 GCa cases and 1172 cancer-free controls of ethnic Han Chinese to construct a weighted genetic risk score (GRS). Then, we included 633 GCa cases with available clinical information, fit GRS in a fractional polynomial Cox proportional hazards regression model to investigate whether there is a dose-dependent effect of GRS on risk of death in survival analysis. Dynamic predictive value of genetic risk for prognosis was also calculated. The results showed that the increase of GRS had no effect on risk of death in these GCa patients. Compared with GCa patients with the medium GRS, there was no significant difference in survival in patients with either a low (P = 0.349) or a high (P = 0.847) GRS. The results unchanged when data were stratified by tumor stage and Lauren's classification. Time-dependent predictive value for prognosis in considering both clinical factors and GRS was comparable with that in considering clinical factors alone, for either all patients (P = 0.986) or stage- and Laruen type-based subgroups (P > 0.05 for all). In conclusion, higher polygenic susceptibility loci for GCa may not indicate worse prognosis of Chinese patients. Additional variants of relevant genes modulating GCa patients' survival need to be further identified.

Induced pluripotent stem cells (iPSCs) derived from somatic cells have enormous potential for clinical applications. Notably, it was recently reported that reprogramming from somatic cells to iPSCs can induce genomic copy number variation (CNV), which is one of the major genetic causes of human diseases. However it was unclear if this genome instability is dependent on reprogramming methods and/or the genetic background of donor cells. Furthermore, genome-wide CNV analysis is technically challenging and CNV data need to be interpreted with care.

Human leukocyte antigen DPB1 was reported to contain singly nucleotide polymorphisms conferring the strongest susceptibility to systemic sclerosis in Korean population. However, associations of specific DPB1 alleles with SSc vary in different ethnic populations. The aim of this study was to profile DPB1 alleles in Chinese population and to identify specific DPB1 alleles in association with SSc and clinical and serological features of SSc in Han Chinese. A cohort containing 338 patients with SSc and 480 gender-matched and unrelated controls were examined in the study. The HLA-DPB1 genotyping was performed with sequence-based typing method. Exact p-values were obtained (Fisher's test) from 2×2 tables of allele counts or allele carriers and disease status. Thirty eight DPB1 alleles were found in the cohort. DPB1*05:01 was the most common allele in this cohort. DPB1*03:01 and *13:01 were significantly increased in SSc. DPB1*13:01 association had already been described in other ethnic populations, whereas DPB1*03:01 was specific to Han Chinese patients with SSc. In addition, comparisons between SSc subsets indicated that patients carrying DPB1*03:01 were more likely to develop pulmonary fibrosis, DPB1*04 carriers were increased in SSc patients with anti-centromere autoantibodies and in contrast, SSc patients with homozygous DPB1*05:01 showed an opposite association with marginal significance.

Human leucocyte antigen (HLA) B*27 is a susceptibility allele to ankylosing spondylitis (AS). However, major AS-associated subtypes of HLA-B*27 and other HLA-B alleles vary in different ethnic populations. Herein, we examined HLA-B alleles in a total of 360 AS patients and 350 controls of Chinese Han ancestry. The HLA-B genotyping was performed with sequence-based typing (SBT) method. Six HLA-B*27 subtypes B*27:04, B*27:05, B*27:07, B*27:08, B*27:10 and B*27:15 were observed in the cohorts. HLA-B*27:04:01 and -B*27:05:02 appeared significantly increased in AS patients, which indicated as two major susceptibility alleles to AS. Homozygous B*27 was observed only in AS patients. There are 30 HLA-B alleles identified in the studies. HLA-B*15, especially B*15:01:01:01, appeared as the major allele type in the Chinese controls. Some common HLA-B alleles such as HLA-B*15, B*13, B*46 and B*51 were significantly reduced in Chinese AS patients. In conclusion, the studies profiled the HLA-B alleles, and identified major susceptibility subtypes of B27 to AS in Han Chinese population.

Chromatin modulators are emerging as attractive drug targets, given their widespread implication in human cancers and susceptibility to pharmacological inhibition. Here we establish the histone methyltransferase G9a/EHMT2 as a selective regulator of fast proliferating myeloid progenitors with no discernible function in hematopoietic stem cells (HSCs). In mouse models of acute myeloid leukemia (AML), loss of G9a significantly delays disease progression and reduces leukemia stem cell (LSC) frequency. We connect this function of G9a to its methyltransferase activity and its interaction with the leukemogenic transcription factor HoxA9 and provide evidence that primary human AML cells are sensitive to G9A inhibition. Our results highlight a clinical potential of G9A inhibition as a means to counteract the proliferation and self-renewal of AML cells by attenuating HoxA9-dependent transcription.

Recent genome-wide association studies (GWAS) have found a single nucleotide polymorphism (SNP, rs2274223 A>G) in PLCE1 to be associated with risk of gastric adenocarcinoma. In the present study, we validated this finding and also explored the risk associated with another unreported potentially functional SNP (rs11187870 G>C) of PLCE1 in a hospital-based case-control study of 1059 patients with pathologically confirmed gastric adenocarcinoma and 1240 frequency-matched healthy controls.

Xeroderma pigmentosum group D (XPD) codes for a DNA helicase involved in nucleotide excision repair that removes platinum-induced DNA damage. Genetic polymorphisms of XPD may affect DNA repair capacity and lead to individual differences in the outcome of patients after chemotherapy. This study aims to identify whether XPD polymorphisms affect clinical efficacy among advanced non-small cell lung cancer (NSCLC) patients treated with platinum-based chemotherapy.

The genes of SPARC, CCR2, and SMAD3 are implicated in orchestrating inflammatory response that leads to fibrosis in scleroderma and other fibrotic disorders. The aim of the studies is to evaluate synergistic anti-fibrotic potency of the siRNAs of these genes.

Endothelial cell injury and subsequent inflammation play pivotal roles in the pathogenesis of pulmonary fibrosis, a progressive and fatal disorder. We found previously that salvianolic acid B (SAB) attenuated experimental pulmonary fibrosis. Pulmonary fibrosis is driven by inflammation, but the anti-inflammatory role and mechanism of SAB on the treatment of pulmonary fibrosis is still unknown. Here, our in vivo studies showed that SAB had a strong anti-inflammatory effect on bleomycin-instilled mice by inhibiting inflammatory cell infiltration and inflammatory cytokine production. Moreover, SAB protected endothelial cells against oxidative stress injury and inhibited endothelial cell apoptosis in bleomycin-treated mice. The in vitro studies also showed that SAB decreased the H2O2-induced overproduction of reactive oxygen species to protect EA.hy926 endothelial cells from oxidative damage, and further inhibited H2O2-induced permeability and overexpression of pro-inflammatory molecules. The next studies revealed that SAB inhibited the H2O2-induced cell apoptosis and attenuated the decrease of tight junction-related gene expression, resulting in a decrease of the endothelial permeability in injured endothelial cells. Furthermore, Western blot analysis suggested that SAB decreased endothelial cell permeability and expression of pro-inflammatory cytokines by inhibiting MAPK and NF-κB signaling pathways. Taken together, these data indicate that SAB exerted anti-inflammatory roles in pulmonary fibrosis by protection of the endothelial cells against oxidative stress injury, mediated by inhibition of endothelial permeability and expression of pro-inflammatory cytokine via the MAPK and NF-κB signaling pathways.

Asymptomatic brain abnormalities are common incidental findings on brain MRI in the elderly population and can be regarded as imaging markers of early stroke and dementia. We initiated the Taizhou Imaging Study (TIS) to examine the prevalence and correlates of incidental findings using brain MRI among an elderly population residing in a rural area of China. A total of 562 individuals, at the age of 55 to 65 years, participated in the TIS study with a response rate of 90%. The prevalence of lacunes, white matter hyperintensity (WMH), cerebral microbleeds (CMB), perivascular space, and intracranial arterial stenosis was 26.69%, 10.68%, 18.51%, 27.76%, and 12.81%, respectively. Age and hypertension were the major correlates of these incidental findings. Per each year increase in age, the risks of WMH and CMB increased by 15% and 14%. Compared to individuals with normal blood pressure, individuals with hypertension had an increased risk of all incidental findings, with the adjusted odds ratios of 2.28 to 5.45. Correlations of age, gender and body mass index with brain gray matter fraction were also observed. The high prevalence of these findings indicates a need of preventative strategy to help prevent future stroke and dementia in this population.

Nucleotide excision repair (NER) pathway plays critical roles in repairing DNA disorders caused by platinum. To comprehensively understand the association between variants of NER and clinical outcomes of platinum-based chemotherapy, 173 SNPs in 27 genes were selected to evaluate association with toxicities and efficiency in 1004 patients with advanced non-small cell lung cancer. The results showed that consecutive significant signals were observed in XPA, RPA1, POLD1, POLD3. Further subgroup analysis showed that GTF2H4 presented consecutive significant signals in clinical benefit among adenocarcimoma. In squamous cell carcinoma, rs4150558, rs2290280, rs8067195 were significantly associated with anemia, rs3786136 was significantly related to thrombocytopenia, ERCC5 presented consecutive significant signals in response rate. In patients receiving TP regimen, significant association presented in neutropenia, thrombocytopenia and gastrointestinal toxicity. Association with anemia and neutropenia were found in GP regimen. rs4150558 showed significant association with anemia in NP regimen. In patients > 58, ERCC5 showed consecutive significant signals in gastrointestinal toxicity. Survival analysis showed SNPs in POLD2, XPA, ERCC6 and POLE were significantly associated with progression free survival, SNPs in GTF2H4, ERCC6, GTF2HA, MAT1, POLD1 were significantly associated with overall survival. This study suggests SNPs in NER pathway could be potential predictors for clinical outcomes of platinum-based chemotherapy among NSCLC.

Retinoic acid (RA) is an active metabolite of vitamin A and has been reported to improve the clinical symptoms of patients with systemic sclerosis (SSc). However, the mechanism of RA in the prevention of SSc remains unclear. Regulatory T cells (Tregs) are a subpopulation of T cells with immunosuppressive activity. The quantitative and functional defects of Tregs may mediate the immune dysfunction in SSc. The addition of all-trans retinoic acid (ATRA) to human naïve CD4+ cells could promote the maturation of Tregs and increase the stable expression of Foxp3. In this study, we explored the role of RA on Tregs in SSc CD4+ T cells and its possible epigenetic mechanisms, so as to further understand the mechanisms of RA on SSc.

The aims of this study were to identify candidate pathways associated with serum urate and to explore the genetic effect of those pathways on the risk of gout. Pathway analysis of the loci identified in genome-wide association studies (GWASs) showed that the ion transmembrane transporter activity pathway (GO: 0015075) and the secondary active transmembrane transporter activity pathway (GO: 0015291) were both associated with serum urate concentrations, with PFDR values of 0.004 and 0.007, respectively. In a Chinese population of 4,332 individuals, the two pathways were also found to be associated with serum urate (PFDR = 1.88E-05 and 3.44E-04, separately). In addition, these two pathways were further associated with the pathogenesis of gout (PFDR = 1.08E-08 and 2.66E-03, respectively) in the Chinese population and a novel gout-associated gene, SLC17A2, was identified (OR = 0.83, PFDR = 0.017). The mRNA expression of candidate genes also showed significant differences among different groups at pathway level. The present study identified two transmembrane transporter activity pathways (GO: 0015075 and GO: 0015291) were associations with serum urate concentrations and the risk of gout. SLC17A2 was identified as a novel gene that influenced the risk of gout.

Murine transplantation models are used extensively to research immunological rejection and tolerance. Here we studied both murine heart and liver allograft models using microarray technology. We had difficulty in identifying genes related to acute rejections expressed in both heart and liver transplantation models using two standard methodologies: Student's t test and linear models for microarray data (Limma). Here we describe a new method, standardized fold change (SFC), for differential analysis of microarray data. We estimated the performance of SFC, the t test and Limma by generating simulated microarray data 100 times. SFC performed better than the t test and showed a higher sensitivity than Limma where there is a larger value for fold change of expression. SFC gave better reproducibility than Limma and the t test with real experimental data from the MicroArray Quality Control platform and expression data from a mouse cardiac allograft. Eventually, a group of significant overlapping genes was detected by SFC in the expression data of mouse cardiac and hepatic allografts and further validated with the quantitative RT-PCR assay. The group included genes for important reactions of transplantation rejection and revealed functional changes of the immune system in both heart and liver of the mouse model. We suggest that SFC can be utilized to stably and effectively detect differential gene expression and to explore microarray data in further studies.

Behçet's disease (BD) is a multi-systemic inflammatory disease. Previous reports indicated that MICA*009 confers susceptibility to BD. MICA*049 differs from MICA*009:01, a major MICA*009 subtype, only at codon 335 in exon 6. However, the potential association of MICA*049 with BD  has not been addressed. In this study, we differentiated association among MICA*049, MICA*009 and HLA-B*51 with BD. A Han Chinese cohort consisting of 41 BD patients and 197 ethnically matched controls were examined with sequencing and T-ARMS-PCR for genotyping of MICA, and ARMS-PCR for HLA-B*51. The phenotype frequency of MICA*049 (41.5% versus 8.1%, OR = 8.01, P = 1.91 × 10-8) and HLA-B*51 (46.3% versus 15.7%, OR = 4.62, P = 1.21 × 10-5) were significantly higher in BD patients than those in controls, whereas MICA*009 showed no significant difference between the two groups (17.1% versus 13.2%, OR = 1.35, P = 0.51). After stratification for the effect of HLA-B*51, MICA*049 was still associated with BD in HLA-B*51 negative patients (OR = 40.61, P = 0.02). Our results indicate that MICA*049, not MICA*009, is a risk factor to BD, and that is independent from HLA-B*51 in the Han Chinese cohort.

We investigated whether genetic susceptibility to tuberculosis (TB) influences lung adenocarcinoma development among never-smokers using TB genome-wide association study (GWAS) results within the Female Lung Cancer Consortium in Asia. Pathway analysis with the adaptive rank truncated product method was used to assess the association between a TB-related gene-set and lung adenocarcinoma using GWAS data from 5512 lung adenocarcinoma cases and 6277 controls. The gene-set consisted of 31 genes containing known/suggestive associations with genetic variants from previous TB-GWAS. Subsequently, we followed-up with Mendelian Randomization to evaluate the association between TB and lung adenocarcinoma using three genome-wide significant variants from previous TB-GWAS in East Asians. The TB-related gene-set was associated with lung adenocarcinoma (p = 0.016). Additionally, the Mendelian Randomization showed an association between TB and lung adenocarcinoma (OR = 1.31, 95% CI: 1.03, 1.66, p = 0.027). Our findings support TB as a causal risk factor for lung cancer development among never-smoking Asian women.

Recent evidence supports a role for microRNA-223 (miR-223) in modulating tumor cell sensitivity to chemotherapeutic drugs; however, its role in cellular resistance to the effects of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) used in treatment of non-small cell lung cancer (NSCLC) remains to be elucidated. The levels of miR-223 in parental cell line (HCC827) and erlotinib resistant HCC827 cell line (HCC827/ER) were detected by qRT-PCR. HCC827/ER cells were treated with MK-2206 to block the Akt signaling pathway or RO4929097 to block the Notch signaling pathway, and then transfected with an miR-223 inhibitor or interference expression plasmid of F-Box/WD repeat-containing protein 7 (FBXW7) or insulin-like growth factor 1 receptor (IGF1R). HCC827 cells were transfected with miR-223 mimics. Next, CCK-8, colony formation, and flow cytometric apoptosis assays were used to assess cell resistance to erlotinib. When compared with its expression in HCC827 cells, miR-223 expression was significantly up-regulated in HCC827/ER cells. Blocking either the Akt or Notch signaling pathway and reducing miR-223 expression resulted in decreased resistance in HCC827/ER cells. Conversely, increasing miR-223 expression induced cell resistance to erlotinib in HCC827 cells. miR-223 enhanced resistance to erlotinib by down-regulating FBXW7 expression. Reducing FBXW7 expression lowered resistance to erlotinib in HCC827/ER cells, while interference with expression of IGF1R produced no significant effect. This study demonstrated that NSCLC cells can up-regulate their levels of miR-223 expression via the Akt and Notch signaling pathways. miR-223 may serve as an important regulator of erlotinib sensitivity in NSCLC cells by targeting FBXW7.