Guohong Deng

Regulatory Polymorphisms in the Promoter of CXCL10 Gene and Disease Progression in Male Hepatitis B Virus Carriers

BACKGROUND & AIMS The importance of expression of interferon gamma-inducible protein of 10 kilodaltons (IP-10, CXCL10) during chronic hepatitis B virus (HBV) infection has been recently emphasized. In this report, we investigated whether the naturally occurred sequence variations in the CXCL10 gene impact liver damage and disease progression of chronic HBV infection. METHODS A hospital-based case-control study was conducted, and a total of 613 and 1787 unrelated Han Chinese HBV carriers were recruited from Beijing and Chongqing, respectively. We systematically screened sequence variations in the CXCL10 gene and examined the association between the variations in this gene and susceptibility to disease progression of chronic HBV infection in Chinese populations from Beijing and Chongqing. Functional analyses were conducted to verify the biological significances of the associated genetic variation. RESULTS We identified that the polymorphism G-201A, located in the promoter region of CXCL10, was associated with susceptibility to disease progression in male HBV carriers (dominant model; odds ratio, 1.53; P = .001). Functional analyses show that the G-201A polymorphism alters the binding affinity of nuclear protein and regulates CXCL10 expression. We observed higher CXCL10 transcription in interferon gamma-stimulated peripheral blood mononuclear cells with the disease-susceptible genotypes. Enzyme-linked immunosorbent assay and immunohistochemical analysis showed augmented CXCL10 production in serum and liver tissues of progressed HBV carriers. CONCLUSIONS The novel regulatory polymorphism G-201A [corrected] in the promoter of CXCL10 gene could be a part of the genetic variation underlying the susceptibility of individuals to disease progression of chronic HBV infection.

Regulatory polymorphisms in the IL-10 gene promoter and HBV-related acute liver failure in the Chinese population

Summary.  Recent reports indicated that high levels of interleukin 10 (IL‐10) contribute to the monocytes paralysis and poor clinical outcome in acute liver failure (ALF). Polymorphisms in the promoter region of IL‐10 affect IL‐10 production and confer susceptibility to inflammatory diseases. The aim of this study was to determine the possible association of the three polymorphisms (A‐1082G, T‐819C, A‐592C) in the IL‐10 gene promoter with the susceptibility to hepatitis B virus (HBV)‐related ALF in a Chinese population. The IL‐10 gene promoter polymorphisms were genotyped in 414 unrelated healthy blood donors, 367 asymptomatic HBV carriers and 345 HBV‐related ALF patients. Functional analyses were conducted to verify the biological significances of the associated genetic variations. The allele frequencies of IL‐10−592C and −819C were significantly higher in HBV‐related ALF patients than in blood donors and asymptomatic HBV carriers. Logistic regression analysis and stratification analysis with adjustment for age and sex indicated that the polymorphisms of A‐592C and T‐819C were associated with susceptibility to HBV‐related ALF (P = 6.9 × 10−7), and the ‐1082A‐819C‐592C haplotype in the IL‐10 gene promoter were associated with an increased susceptibility to ALF in HBV carriers (dominant model, P = 0.0002, odds ratio = 1.60, 95% CI 1.25–2.07). Functional analyses showed that the A‐592C polymorphism is a nuclear proteins binding site, and the disease susceptible −592C allele had a higher transcription activity compared with −592A allele. This study emphasizes the importance of IL‐10 in the pathophysiology of HBV‐related ALF on the population level.

Relationship between HLA-DR gene polymorphisms and outcomes of hepatitis B viral infections: A meta-analysis

AIM To assess the rigorous relationship between human leukocyte antigens (HLA)-DR alleles and outcomes of hepatitis B virus (HBV) infections by means of meta-analysis. METHODS Medline/PubMed, EMBASE, CNKI and VIP were searched to identify relevant studies. Study quality was evaluated using the Newcastle-Ottawa Scale. Odds ratios (OR) and 95% confidence interval (95% CI) were pooled using Stata 11.0. Subgroup analyses were performed by ethnicity. Heterogeneity and publication bias analyses were performed to validate the credibility. RESULTS A total of 2609 patients with chronic hepatitis B and 2606 controls spontaneously recovering from prior HBV infection were included. Meta-analysis showed that HLA-DR*04 (OR = 0.72, 95% CI: 0.60-0.85) and DR*13 (OR = 0.27, 95% CI: 0.19-0.37) alleles were significantly associated with HBV clearance while patients carrying HLA-DR*03 (OR = 1.47, 95% CI: 1.16-1.87) or DR*07 (OR = 1.59, 95% CI: 1.24-2.03) alleles had a significantly increased risk of chronic HBV persistence. For the HLA-DR*01 polymorphism, a significantly association with HBV clearance was found in Chinese Han group (OR = 0.48, 95% CI: 0.26-0.86), but not found in other ethnic groups (P = 0.191). For other polymorphisms, no association with the HBV infection outcome was found. CONCLUSION HLA-DR*04 and DR*13 alleles may be the protective factors for HBV clearance and HLA-DR*03, and DR*07 alleles may be the risk factors for HBV persistence.

A Common Promoter Variant of TBX21 is Associated with Allele Specific Binding to Yin‐Yang 1 and Reduced Gene Expression

T‐bet is a key regulator for the lineage commitment in CD4 T helper (Th) 1 cells by activating the hallmark production of interferon‐γ, and its expression level is linked to autoimmune, infectious, and allergic diseases. A T to C base substitution has been identified at position ‐1993 in the TBX21 (encoding T‐bet) promoter and has been associated with asthma and systemic lupus erythematosus. This study aimed to investigate the molecular mechanisms responsible for the influence of the T‐1993C polymorphism on transcription and its functional effect by luciferase reporter, EMSAs, Chromatin immunoprecipitation assay, and flow cytometric analysis of intracellular T‐bet, IFN‐γ and IL‐4 expression in activated CD4+ T cells. The presence of a ‐1993T allele obviously increases promoter activity compared with that of a promoter with a ‐1993C allele. TBX21 promoter carrying ‐1993C allele possesses significantly stronger binding affinity to the Yin Yang 1 (YY1) transcription factor than that carrying ‐1993T allele. YY1 overexpression decreased TBX21 promoter function in a T cell line, demonstrating that this element functions as a repressor. The C to T base exchange relieves the repression mediated by YY1. The individuals carrying ‐1993C allele were determined to have significantly diminished expression of TBX21 and IFN‐γ and increased IL‐4 production in cells compared with the individuals carrying ‐1993T allele (P < 0.05). These findings demonstrate that the TBX21 T‐1993C polymorphism represses TBX21 expression and Th1 cytokine production through control of YY1, which might result in the imbalance between Th1 and Th2 immune responses in autoimmune or allergic diseases.

Association of TBX21 gene haplotypes in a Chinese population with systemic lupus erythematosus

Objective: T-cell-specific T-box transcription factor (T-bet) is a member of the T-box family of transcription factors regulating type 1 T-helper (Th1) cell development and is thought to be linked with several autoimmune diseases including systemic lupus erythematosus (SLE). The aim of this study was to evaluate whether T-bet gene (TBX21) polymorphisms or its haplotypes are associated with SLE in a Chinese population. Methods: The study included 248 cases with SLE and 261 gender- and age-matched healthy controls. The polymorphisms T-1993C (rs4794067) and T-1514C (rs17250932) in the TBX21 promoter were identified by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Results: The frequency of both the -1993T and the -1514T allele were significantly higher in SLE patients than in controls. By haplotype analysis, there was significantly decreased frequency of the haplotype at positions -1993C/-1514C in the case group compared with the control group (p = 0.0002). Multifactorial logistic regression analysis showed that individuals with CC/CC haplotype homozygotes had a decreased susceptibility to SLE [p = 0.0004, odds ratio (OR) 0.316, 95% confidence interval (CI) 0.167–0.599]. Conclusion: Our results suggest that the -1993C/-1514C haplotype may be a protective factor for genetic susceptibility to SLE in the Chinese population.

Thyroid dysfunction in chinese patients with chronic hepatitis C treated with interferon alpha: incidence, long-term outcome and predictive factors.

Background Thyroid dysfunction (TD) represents an extra-hepatic manifestation of chronic hepatitis C (CHC) and it may also be a side effect of interferon-alpha (IFN-α) based treatment. However, previous studies have shown a wide variation in the incidence of TD in patients with CHC. Furthermore, the long-term outcomes and the predictive factors of TD in patients who receive IFN-α based treatment have still not been fully studied. Objectives The purpose of this study was to describe the incidence and long-term outcomes of TD in Chinese patients with CHC receiving IFN-αbased treatment. We also aimed to identify the predictive factors of TD associated with this type of therapy. Patients and Methods A retrospective case-series study of 592 consecutive CHC patients with normal baseline thyroid functions, who received IFN-αbased therapy, was performed. Thyroid function was assessed at baseline and every three months during treatment, as well as in the follow-up after cessation of therapy. The incidence and long-term outcomes of TD were observed. The prevalence of pretreatment thyroid peroxidase antibodies (TPOAb) were assayed in a sex- and age-matched nested case-control study. Multivariable stepwise regression analysis was used to explore the independent effects of the baseline factors, on the incidence of TD. Results At the end of the IFN-αbased therapy, 68 patients (11.5%) in the study had developed TD, 58 patients (85.3%) presented with subclinical TD, and only 10 patients (14.7%) developed overt thyroiditis. The thyroid function of 46 patients (67.8%) spontaneously returned to normal in the six months of follow-up and only three patients (4.4%) had persistent overt TD symptoms after the 24 month follow-up period. Multivariate stepwise analysis suggested that gender and pretreatment TPOAb were the independent factors related to the incidence of TD. Both female patients (OR, 4.31; 95%CI, 2.06–7.31; P = 1.26×10-4) and participants with a positive pretreatment TPOAb (OR = 3.9, 95%CI, 1.72–8.54, P = 0.008) had an increased risk for the development of TD. Conclusions The incidence of TD in Chinese patients with CHC during IFN-αbased therapy was 11.5%, the majority of which was subclinical, while only a very small group had long-term overt TD requiring ongoing medical therapy. Female gender and pretreatment TPOAb positivity are risk factors for the development of TD during IFN-αbased therapy.

SLCO1B1 *15 haplotype is associated with rifampin-induced liver injury

The organic anion transporting polypeptide 1B1 (OATP1B1, encoded by SLCO1B1) plays an important role in the transport of endogenous and xenobiotic compounds, such as bile acids and rifampin. In this study, the association between OATP1B1 polymorphisms and rifampin hepatotoxicity was investigated using integrated population genetic analysis and functional studies. A total of 273 unrelated patients treated with rifampin were recruited. The allele frequencies were examined in patients with drug (rifampin)-induced liver injury (DILI) (n = 118) and without (non-DILI) (n = 155). Functional analyses were conducted to determine whether the inhibition of bile acids by rifampin was associated with OATP1B1 variants. In the present study, 24 single nucleotide polymorphisms (SNPs) in OATP1B1 were detected in a Chinese population, with two of them causing an amino acid change (rs2306283 and rs4149056). The haplotypes constructed by these two SNPs were OATP1B1 *1a, *1b, *5 and *15, with their respective frequencies being 23.44, 66.30, 0.73 and 9.52% in a total of 273 individuals. The logistic regression analysis indicated that the *15 haplotype was associated with susceptibility to DILI (p = 0.03, OR = 2.04, 95% CI 1.05-3.96). The frequency of the *15 haplotype in DILI patients was significantly higher than that in non-DILI patients (p = 0.03). In the subgroup analysis, the *15 haplotype was associated with susceptibility to cholestatic/mixed injury (p = 0.03, OR = 2.31, 95% CI 1.06-5.02). Functional assessment of the OATP1B1 *15 haplotype revealed that the activity of bile acid uptake was markedly reduced compared to the three other haplotypes. In the inhibition study, the inhibition by rifampin in the *15 haplotype was greater compared to that in the other haplotypes. These results suggest that the OATP1B1 *15 haplotype is an important predisposing factor for rifampin-induced liver injury.

Relationship between HLA-DP gene polymorphisms and clearance of chronic hepatitis B virus infections: Case–control study and meta-analysis

Hepatitis B virus (HBV) infection is a serious public health problem worldwide. Two common genetic variants (rs3077 and rs9277535) of human leukocyte antigen DP (HLA-DP) have been reported to be associated with persistent HBV infection in populations of Japan and Thailand. To confirm whether the association can be replicated in Chinese populations, an independent case-control study were conducted, and two polymorphisms (rs3077 and rs9277535) were genotyped using the TaqMan SNP genotyping assay in 282 persistent chronic HBV carriers and 64 spontaneously HBV recovered carriers. To provide a more definitive conclusion, a meta-analysis combining and summarizing five studies was performed by random-effects model using the DerSimonian and Lairds method. By using logistic regression analysis with adjustment for covariates, including age, sex, and alcohol consumption, the results of our independent case-control study showed that the minor alleles homozygote (AA genotype) of rs3077 and rs9277535 was significantly associated with decreasing risk/protection of HBV persistent chronic infection (for rs3077: P=0.0017, OR=0.29, 95% CI=0.13-0.62; for rs9277535, P=0.0004, OR=0.26, 95% CI=0.12-0.54). The results of meta-analysis pooling all eligible studies also showed that rs3077-A and rs9277535-A alleles were associated with an increased clearance rate to HBV infection (rs3077: OR=0.57, 95% CI=0.44-0.75; rs9277535: OR=0.56, 95% CI=0.47-0.63). These results further confirmed the strong influence of HLA-DP gene variants on risk of spontaneous HBV clearance from persistent HBV infection. Both A alleles of HLA-DP SNP rs3077 and rs9277535 showed strong protective effects for spontaneous HBV clearance from persistent HBV infection in the Han Chinese population.

A cis-acting regulatory variation of the estrogen receptor α (ESR1) gene is associated with hepatitis B virus-related liver cirrhosis.

The hepatic fibrogenesis and sexual dimorphism of hepatitis B virus‐related liver cirrhosis (HBV‐LC) are related to estrogen and its receptors. Abnormal expression of estrogen receptor α (ESR1) is implicated in the development of cirrhosis in both animal models and humans. Here, we examine whether the ESR1 polymorphisms are related to HBV‐LC risk among chronic HBV carriers, and we investigate the functional significance of positively associated polymorphisms. A total of 2,404 unrelated Chinese HBV carriers were recruited to conduct the two‐stage designed case–control study. Two ESR1 haplotype tagging polymorphisms, c.30T>C (rs2077647) and c.453‐397T>C (rs2234693), were genotyped in 1,285 patients with HBV‐LC and in 1,119 asymptomatic HBV carriers. We observed a significantly increased susceptibility to HBV‐LC associated with the c.30C allele (P = 4.2×10−8), c.453‐397C allele (P = 2.0×10−8), and [c.30C; c.453‐397C] haplotype (Dominant model, P = 8.85×10−10, odds ratio = 1.50, 95% CI 1.32∼1.71) compared with the T alleles and (c.30T; c.453‐397T) haplotype of c.30T>C and c.453‐397T>C polymorphisms, respectively. Functional analyses were conducted to verify the biological functions of the associated genetic variations and showed that the c.453‐397T>C polymorphism is a novel c.453‐397C allele‐specific and c‐myb‐dependent enhancer‐like cis‐acting regulatory variation and could be part of the genetic variations underlying the susceptibility of individuals to HBV‐LC. Hum Mutat 32:1128–1136, 2011. ©2011 Wiley‐Liss, Inc.

Effect of HLA-DP and IL28B gene polymorphisms on response to interferon treatment in hepatitis B e-antigen seropositive chronic hepatitis B patients

The reason why the majority of chronic hepatitis B (CHB) patients do not respond to conventional interferon (IFN)‐α or pegylated interferon (PEG IFN) treatment has not been formally demonstrated. The aim of this study was to investigate the association between single nucleotide polymorphisms (SNPs) and response to IFN‐α or PEG IFN therapy in Chinese patients with CHB.