ABSTRACT
BACKGROUND: High mobility group box1 (HMGB1) and poly(ADP-ribose) polymerase1 (PARP1) proteins repair cellular DNA damage. Reduced expression of the corresponding genes can lead to an impaired DNA damage repair mechanism. Intracellular replication of hepatitis B virus (HBV) in such conditions can favor the integration of viral DNA into host genome leading to the development of hepatocellular carcinoma (HCC). OBJECTIVE: This study was performed to assess the expression of HMGB1 and PARP1 mRNAs in conjunction with the estimation of HBV replication intermediate pregenomic RNA (PgRNA) in various phases of HBV infection. MATERIALS: Eighty eight patients and 26 voluntary blood donors as controls were included in the study. Patients were grouped in to acute (AHB; n = 15), inactive carriers (IC; n = 36), cirrhosis (Cirr; n = 25) and hepatocellular carcinoma (HCC; n = 12). Serum HBV DNA was quantified by real time polymerase chain reaction (PCR) assay. Expression of HMGB1, PARP1 and PgRNA were evaluated using peripheral blood mononuclear cells (PBMCs) derived RNA by reverse transcription PCR (RT-PCR) and densitometry. RESULTS: Significant reduction of HMGB1 and PARP1 gene expressions (P < 0.05) were observed in patients than controls with more explicit decline of PARP1 (P = 0.0002). Both genes were significantly downregulated (P < 0.001) in ICs than controls. In ICs, HMGB1 was significantly lowered than cirrhosis (P = 0.002) and HCC (P = 0.0006) while PARP1 declined significantly (P = 0.04) than HCC. Level of PgRNA was comparable in all the disease categories. CONCLUSION: In conclusion, our findings indicate impaired DNA damage repair mechanisms in HBV infected cells of ICs. This, along with low viral load but higher level of PgRNA in this group is suggestive of the diversion of HBV replication pathway that might facilitate viral DNA integration in to host genome. Intrusion of HBV PgRNA reverse transcription in early stage of infection might appear advantageous to thwart the development of HCC.
ABSTRACT
Introduction. HBV genotypes and subtypes are useful clinical and epidemiological markers. In this study prevalent HBV genotypes were assessed in relation to serological profile and clinical status. Material & Methods. 107 cases of HBV were genotyped. Detailed clinical history was elicited from them. HBsAg, HBeAg, anti-HBs, anti-HBe, and anti-HBc-IgM were assessed. HBV genotyping was performed using Kirschberg's type specific primers (TSP-PCR), heminested PCR, and Naito's monoplex PCR. Nucleotide sequencing was performed. Results. A total of 97 (91%) were genotyped following the methods of Kirschberg et al./Naito et al. Genotype D was by far the most prevalent genotype 91 (85.04%) in this region. A surprising finding was the detection of genotype F in 5 (4.67%) of our patients. Genotype A strangely was observed only in one case. In 85.7% genotype D was associated with moderate to severe liver disease, 43.9% HBeAg, and 18.7% anti-HBc-IgM positivity. Majority of genotype F (80%) was seen in mild to moderate liver disease. It was strongly associated with HBeAg 60% and 20% anti-HBc-IgM positivity. Conclusion. Emergence of genotype F in India merits further study regarding its clinical implications and treatment modalities. Knowledge about HBV genotypes can direct a clinician towards more informed management of HBV patients.
ABSTRACT
BACKGROUND: The interferon regulatory factors (IRFs) are a family of transcription factors known to be involved in the modulation of cellular responses to interferons (IFNs) and viral infection. While IRF-1 acts as a positive regulator, IRF-2 is known to repress IFN-mediated gene expression. The increase in the IRF-1/IRF-2 ratio is considered as an important event in the transcriptional activation of IFN-α gene toward development of the cellular antiviral response. OBJECTIVE: This study was performed to assess the expression of IRF mRNAs along with the expression level of IFN-α, its receptor (IFNAR-1), and the signal transduction factor (STAT-1) in treatment naive hepatitis C virus (HCV)-infected subjects. MATERIALS: Thirty-five chronically infected (CHC) patients and 39 voluntary blood donors as controls were included in the study. Quantification of HCV-RNA (ribonucleic acid) and genotyping were done by real-time polymerase chain reaction (PCR) and hybridization assays, respectively, using patient's serum/plasma. In both controls and patients, the serum level of IFN-α and IFN-α was measured by flow cytometry. Target gene expressions were studied by retro-transcription of respective mRNAs extracted from peripheral blood mononuclear cells (PBMCs) followed by PCR amplification and densitometry. Minus-strand HCV-RNA as a marker of viral replication in PBMCs was detected by an inhouse PCR assay. RESULTS: Both IRF-1 and IRF-2 genes were significantly enhanced in CHC than in control subjects (P < 0.001). A significant positive correlation (r (2) = 0.386, P <0.01) was obtained between higher IRF-2 gene expression and increasing level of HCV-RNA. Chronically infected subjects (13%) harboring replicating HCV in PBMCs showed no significant differences in gene expressions than the subjects without HCV in PBMCs. CONCLUSION: Our findings indicate that HCV modulates host immunity by inducing IRF-2 gene to counteract IRF-1-mediated IFN-α gene expression. Since the IRF-2 gene is known to encode oncogenic protein, the role of IRF-2 in CHC patients developing hepatocellular carcinoma warrants further studies.
