Hepatitis C virus core protein-induced miR-93-5p up-regulation inhibits interferon signaling pathway by targeting IFNAR1.

AIM: To investigate the mechanism by which hepatitis C virus (HCV) core protein-induced miR-93-5p up-regulation regulates the interferon (IFN) signaling pathway. METHODS: HCV-1b core protein was exogenously expressed in Huh7 cells using pcDNA3.1 (+) vector. The expression of miR-93-5p and interferon receptor 1 (IFNAR1) was measured using quantitative reverse transcription-polymerase chain reaction and Western blot. The protein expression and phosphorylation level of STAT1 were evaluated by Western blot. The overexpression and silencing of miR-93-5p and IFNAR1 were performed using miR-93-5p agomir and antagomir, and pcDNA3.1-IFNAR1 and IFNAR1 siRNA, respectively. Luciferase assay was used to identify whether IFNAR1 is a target of miR-93-5p. Cellular experiments were also conducted. RESULTS: Serum miR-93-5p level was increased in patients with HCV-1b infection and decreased to normal level after HCV-1b clearance, but persistently increased in those with pegylated interferon-α resistance, compared with healthy subjects. Serum miR-93-5p expression had an AUC value of 0.8359 in distinguishing patients with pegylated interferon-α resistance from those with pegylated interferon-α sensitivity. HCV-1b core protein increased miR-93-5p expression and induced inactivation of the IFN signaling pathway in Huh7 cells. Furthermore, IFNAR1 was identified as a direct target of miR-93-5p, and IFNAR1 restore could rescue miR-93-5p-reduced STAT1 phosphorylation, suggesting that the miR-93-5p-IFNAR1 axis regulates the IFN signaling pathway. CONCLUSION: HCV-1b core protein-induced miR-93-5p up-regulation inhibits the IFN signaling pathway by directly targeting IFNAR1, and the miR-93-5p-IFNAR1 axis regulates STAT1 phosphorylation. This axis may be a potential therapeutic target for HCV-1b infection.

miR-375 is downregulated by promoter hypermethylation in MIN6 insulinoma cells.

Epigenetics may affect the susceptibility for type 2 diabetes mellitus (T2DM). Aberrant DNA methylation patterns are nowadays recognized as a key epigenetic hallmark of T2DM. Previously, our studies have shown that the hypomethylation of human miR-375 promoter may contribute to the pathogenesis of T2DM. However, no comprehensive study defines the miR-375 promoter methylation patterns present in the established pancreatic ß cell line. To address this matter, we have analyzed the DNA methylation profile of insulinoma MIN6 cells by MassARRAY spectrometry and employed the DNA demethylating drug 5-aza-2'-deoxycytidine (5-aza-CdR) to treat MIN6 cells to explore the methylation patterns of the mmu-miR-375. The expression of mmu-miR-375 in mRNA level was measured by quantitative RT-PCR (qRT-PCR). Methylation analysis reveals that MIN6 cells display hypermethylation at the mmu-miR-375 promoter. Following the decreased methylation of mmu-miR-375, the relative expression of mmu-miR-375 increased gradually after 5-Aza-CdR treatment. In addition, we find that there was an inverse correlation between DNA methylation levels and transcription level of mmu-miR-375. In summary, this is the first report for analyzing mmu-miR-375 promoter methylation using MALDI-TOF MS technology and our results indicate that promoter hypermethylation of the mmu-miR-375 is a common event in MIN6 cells.

Effect of entecavir on CD4+ T-cell subpopulations in patients with chronic hepatitis B.

UNLABELLED:  Background and aims. CD4+ T cells play an important role in response to hepatitis B virus (HBV) infection. We investigated the change in CD4+ T-cell subpopulations and viral load in patients with chronic HBV infection who were treated with entecavir. MATERIAL AND METHODS: Thirty patients with chronic HBV infection were enrolled according to the criteria recommended by the Chinese Society of Infectious Diseases and the Chinese Society of Hepatology. The expressions of signature transcription factors and cytokines of CD4+ T-cell subpopulations were measured in chronic hepatitis B (CHB) patients treated with entecavir treatment. RESULTS: Entecavir treatment significantly attenuated hepatitis B virus DNA load and affected the CD4+ T-cell subsets in CHB patients. A dramatic decrease in the Th17 and Treg cell frequencies and expressions of their related cytokines were found in CHB patients with entecavir treatment. In contrast, entecavir treatment caused a remarkable increase in the Th2 cell frequencies and expressions of their related cytokines. CONCLUSION: Our results suggested that Th17 and Treg cells were the more sensitive subtypes to entecavir- induced inhibition of HBV replication compared to Th1 and Th2 cells in chronic HBV patients.

[Distribution and characteristics of hepatitis B virus genotypes in Uighur patients with chronic hepatitis B in Xinjiang province of China].

OBJECTIVE: To study genotype distribution and the characteristics of hepatitis B virus (HBV) in Uighur patients with chronic hepatitis B (CHB) in Xinjiang, China. METHODS: Type specific primers and PCR were used to detect the HBV genotypes of 127 Uighur CHB patients in Xinjiang. Genotyping results were confirmed by PCR product sequencing. RESULTS: Among the 127 patients, the proportions of genotype D, B, C and B/D, C/D, B/C/D were 39.4% (50/127), 22.0% (28/127), 16.5% (21/127) and 9.4% (12/127), 8.7% (11/127) and 3.9% (5/127), respectively. The distribution of the HBV genotypes showed no significant differences between male and female patients (x2 = 8.058, P > 0.05), between HBeAg positive and negative patients (x2 = 6.033, P > 0.05), and between patients of different ages (x2 = 3.137, P > 0.05). CONCLUSION: Genotype D HBV is predominant in Uighur patients with chronic hepatitis B in Xinjiang. The distribution of various HBV genotypes shows no significant differences between these Uighur patients with different HBeAg positivity, sex and age.