Association of Hypoxia-Inducible Factor-2 Alpha Gene Polymorphisms with the Risk of Hepatitis B Virus-Related Liver Disease in Guangxi Chinese: A Case-Control Study

The role of EPAS1 polymorphisms on COPD susceptibility in southern Chinese

Objective

COPD is the most common chronic respiratory disease with complex environmental and genetic etiologies. It was reported that EPAS1 might participate in the occurrence and development of respiratory diseases. However, the association between EPAS1 and COPD was unclear.

Methods

First, a case-control study enrolling 1130 COPD patients and 1115 healthy controls in Guangzhou was conducted to clarify the association between EPAS1 polymorphisms and COPD susceptibility. Secondly, a prevalence study recruited 882 participants in Gansu to verify the effect of positive polymorphisms on lung function. Finally, the 10-year absolute risk considering environmental factors and genetic variations was calculated by the method of Gail and Bruzzi.

Results

EPAS1 rs13419896 AA genotype reduced COPD risk in southern Chinese (AA vs. GG: adjusted OR = 0.689, 95% CI = 0.498-0.955; AA vs. GG/GA: adjusted OR = 0.701, 95% CI = 0.511-0.962). Further, the rs13419896 A allele was significantly associated with higher pre-FEV1/pre-FVC in both the Guangzhou and Gansu populations (P < 0.05). Smoking status, coal as fuels, education level, and rs13419896 G > A were finally retained to develop a relative risk model for males. Smoking status, biomass as fuels, and rs13419896 G > A were retained in the female model. The population-attributable risk of the male or female model was 0.457 (0.283-0.632) and 0.421 (0.227-0.616), respectively.

Conclusions

This study first revealed that EPAS1 rs13419896 G > A decreased COPD susceptibility and could be a genetic marker to predict the 10-year absolute risk for COPD.

Association of HLADQ-B1 polymorphisms in three generations of chronic hepatitis B patients

The presence of polymorphisms in the human leukocyte antigen (HLA)-DQB1 gene, along with its expression, has been demonstrated to be correlated with spontaneous clearance and susceptibility to HBV infection. The present study aimed to evaluate the possible role of genetic polymorphisms in HLA-DQB1 in three generations of patients with chronic hepatitis B (CHB). Based on the inclusion criteria, 90 CHB patients, 18 individuals recovered from HBV infection, and 40 healthy subjects were chosen. The DNA contents of the whole blood samples were extracted in order to perform HLA-DQB1 typing by the PCR technique. Besides whole blood samples, sera were applied to measure liver function tests (LFTs), as well as the titers of anti-HDV and anti-HCV. Also, in all CHB patients were measured liver stiffness (LSM) by Fibro Scan. The results of HLA-DQB1 polymorphisms (rs2856718 and rs7453920) demonstrated that the majority of polymorphisms in CHB patients were HLA-DQB1*03, HLA-DQB1*05, HLA-DQB1*04:01 and HLA-DQB1*03:01 that associated with HBV persistence and chronicity. Among the patients who showed these polymorphisms, the mean±SD, LSM was 4±1.57 KPa and most of them, F grade was reported as F2, which was a sign of disease progression towards chronicity. HLA polymorphisms imputation revealed that HLA-DQB1*06:04 (3.4%, P-Value= 0.2) was detected only in healthy subjects as protective polymorphism, while the allele HLA-DQB1*03:03 was reported in both healthy subjects (P-Value= 0.06) and recovered patients (P-Value= 0.1) as suppressor of CHB formation. The allele HLA-DQB1*05:02 was found in both healthy subjects (3.4%) and CHB patients (4.5%) which was associated with risk to liver cirrhosis (P-Value= 0, OR: 0.002 0.95CI: 0.000-0.15). HLA polymorphism analysis indicated that 17.39% of patients who were seropositive for anti-HCV carried the HLA-DQB1*03:01. HBV resistance or infection risk could be assessed by DBQ1 typing. The existence of polymorphisms in HLA gene could influence the clearance (HLA-DQB1*03:03) or susceptibility and persistence of infection (HLA-DQB1*03, HLA-DQB1*05, HLA-DQB1*04:01 and HLA-DQB1*03:01). These results have the potential to improve personalized therapy and prognosis for HBV infection.

Loss of Heterozygosity for KrasG12D Promotes Malignant Phenotype of Pancreatic Ductal Adenocarcinoma by Activating HIF-2α-c-Myc-Regulated Glutamine Metabolism

Loss of heterozygosity (LOH) for KRAS, in which a wild-type KRAS allele is progressively lost, promotes invasive and migratory abilities of pancreatic ductal adenocarcinoma (PDAC) cells and tissues. Moreover, the occurrence of KrasG12D-LOH activates nonclassical glutamine metabolism, which is related to the malignant behavior of PDAC cells. Herein, we aim to demonstrate the regulatory link between hypoxia-inducible factor-2α (HIF-2α) and glutamine metabolism that mediates malignant phenotypes in KrasG12D-LOH PDAC cells. HIF-2α-shRNA knockdown lentivirus transfection and metabolite analysis were performed in KrasG12D-LOH and KrasG12D cell lines, respectively. Cell proliferation, migration, and invasion were examined using Cell Counting Kit-8, colony formation, and Transwell assays. Cell cycle phase and apoptosis were determined using flow cytometry. Western blotting and real-time quantitative PCR were also performed. Additionally, a subcutaneous xenograft mouse model was established. LOH stimulated HIF-2α activity and transactivated c-Myc, which has a central regulatory effect on glutamine metabolism independent of hypoxia. Meanwhile, HIF-2α silencing repressed KrasG12D-LOH PDAC cell proliferation, invasion, and migration. HIF-2α knockdown inhibited glutamine uptake and GOT1 expression via a c-Myc-dependent pathway. Collectively, KrasG12D-LOH can activate HIF-2α to regulate c-Myc-mediated glutamine metabolism and promote malignant phenotypes. Moreover, targeting HIF-2α-c-Myc regulated nonclassical glutamine metabolism, providing a new therapeutic perspective for KrasG12D-LOH PDAC.

Oxygen Sensing and Viral Replication: Implications for Tropism and Pathogenesis

The ability to detect and respond to varying oxygen tension is an essential prerequisite to life. Several mechanisms regulate the cellular response to oxygen including the prolyl hydroxylase domain (PHD)/factor inhibiting HIF (FIH)-hypoxia inducible factor (HIF) pathway, cysteamine (2-aminoethanethiol) dioxygenase (ADO) system, and the lysine-specific demethylases (KDM) 5A and KDM6A. Using a systems-based approach we discuss the literature on oxygen sensing pathways in the context of virus replication in different tissues that experience variable oxygen tension. Current information supports a model where the PHD-HIF pathway enhances the replication of viruses infecting tissues under low oxygen, however, the reverse is true for viruses with a selective tropism for higher oxygen environments. Differences in oxygen tension and associated HIF signaling may play an important role in viral tropism and pathogenesis. Thus, pharmaceutical agents that modulate HIF activity could provide novel treatment options for viral infections and associated pathological conditions.

The role of IL22 polymorphisms on liver cirrhosis in patients with hepatitis B virus: A case control study

AIMS

Interleukin(IL)-22 plays an important role in promoting liver regeneration and repair, but its role in chronic HBV-related liver diseasesis not clear. The goal of this study was to evaluate associations between eight IL22 single nucleotide polymorphisms (SNPs) and the development of chronic HBV cirrhosis and HBV-related HCC within a Chinese Han population.

METHODS

We investigated associations between single nucleotide polymorphisms (SNPs) in the IL22 gene (rs1026788, rs2227472, rs2227491, rs2227485, rs1179249, rs2046068,rs2227473, and rs7314777) and the risk of HBV-related chronic liver diseases within a Han population in Northeast China. A total of 649 participants were included in the study, including 103 patients with CHB, 264 patients with LC, and 282 patients with HCC. The odds ratios (OR) and corresponding 95% confidence intervals (CI) were calculated using chi-square test. Haplotype analysis was conducted by haploview software.

RESULTS

Genotype and allele distributions of SNPs rs1179249 and rs2227472 differed between LC and CHB groups (both P < 0.05).The G alleles of SNP rs2227491 and rs1026788 were more frequent in the LC group than in the CHB group (P = 0.046, P = 0.041 respectively). A IL22 haplotype consisting of the minor alleles of SNP rs1179249 and the major alleles of seven other SNPs occurred less frequently in the LC and HCC groups than in the CHB group (28.2%, 33.94%, and 37.86%, respectively, P < 0.05). Moreover, there were no significant associations between smoking or drinking and IL22 SNPs on the risk of HCC (P > 0.05).

CONCLUSION

IL22 genetic variations were associated with chronic HBV infection progression, especially in the HBV-LC group. The IL22 genetic variations may help clinicians initiate the correct treatment strategy at the CHB stage.

Quantitative assessment of HLA-DQ gene polymorphisms with the development of hepatitis B virus infection, clearance, liver cirrhosis, and hepatocellular carcinoma

Hepatitis B is one of the most common infectious diseases, which leads to public health problems in the world, especially in Asian counties. In recent years, extensive human genetic association studies have been carried out to identify susceptible genes and genetic polymorphisms to understand the genetic contributions to the disease progression of HBV infection. HLA-DQ gene variations have been reported to be associated with HBV infection/clearance, disease progression and the development of hepatitis B-related complications, including liver cirrhosis (LC) and hepatocellular carcinoma (HCC). However, the results are either inconclusive or controversial. Therefore, to derive a more precise estimation of the association, a meta-analysis was performed. Our data revealed that the HLA-DQ alleles rs2856718-G, rs7453920-A and rs9275319-G were significantly associated with decreased risk of HBV infection and HBV natural clearance. Logistic regression analyses showed that HLA-DQ alleles rs9275572-A significantly increased HBV infection clearance, and decreased HBV natural clearance. However, rs2856718-G and rs9275572-A were not associated with development of cirrhosis. The HLA-DQ polymorphisms (rs2856718 and rs9275572) were associated with a decreased HBV-related HCC risk in all genetic models, but rs9272105-A increased the risk of HBV-related HCC. In addition, no significant association was observed between HLA-DQ rs9275319-G polymorphism and HBV-related HCC. These stratified analyses were limited due to relatively modest size of correlational studies. In future, further investigation on a large population and different ethnicities are warranted. Our findings contribute to the personalized care and prognosis in hepatitis B.