SOCS3 and IRS-1 gene expression differs between genotype 1 and genotype 2 hepatitis C virus-infected HepG2 cells.

BACKGROUND: The poor response to antiviral treatment of hepatitis C virus (HCV)-infected patients with genotype 1b has been associated with a higher prevalence of metabolic syndrome. However, the molecular link between these clinical entities is not clear. The goal of this study was to clarify the role of genotype 1b and 2 in the genetic expression of suppressor of cytokine signaling 3 (SOCS3) and insulin receptor substrate 1 (IRS-1). METHODS: We infected human hepatocellular carcinoma cell line (HepG2) cells with human HCV genotype 1b or 2 and measured the gene and protein expression of SOCS3 at various times. We also evaluated impairment in the insulin pathway by analysis of IRS-1 and phospho-AKT. For the control, we used HepG2 cell cultures treated with non-infectious serum. We also demonstrated the occurrence of HCV infection by the detection of both positive and negative strands in the cells and culture medium. To test infection of the HepG2 cells, we performed quantitative real-time polymerase chain reaction (qRT-PCR) of viral load at different time points. We analyzed the viral genotype in the pellet and supernatant. RESULTS: At each time point, we found positive and negative strands in the infected cells, while in the medium we found positive, but no negative strands. We also detected the presence of the correct genotype in the medium. Two weeks following infection when the viral load was higher, we tested genotype 1b and 2 infected cells. SOCS3 gene expression was significantly higher in genotype 1b-infected cells (median 2.56; mean 2.82+/-0.59) compared with genotype 2 (median 1.34; mean 1.46+/-0.31) (p=0.04) and control cells (median 1.09; mean 1.02+/-0.11, p=0.02). There was no difference between cells exposed to genotype 2 and control cells. Conversely, IRS-1 was significantly lower in genotype 1b-infected cells (median 15.97; mean 15.45+/-0.67) compared with genotype 2-infected cells (median 16.45; mean 16.44+/-0.01, p=0.04). Statistically significant differences were seen when comparing the pAKT/AKT ratio in genotype 1b-infected cells (0.19+/-0.034) and not genotype 1b-infected (genotype 2-infected and non-infected) cells (0.253+/-0.004, p=0.03). This inverse regulation is compatible with interactions between the molecular expression of SOCS3, IRS-1 and phospho-AKT mediated by the genotype 1b virus. CONCLUSIONS: Up-regulation of the SOCS3 gene might be one of the mechanisms governing non-response to therapy and expression of insulin resistance mediated via a direct mechanism at this level of genotype 1b HCV.

Clinical expression of insulin resistance in hepatitis C and B virus-related chronic hepatitis: differences and similarities.

AIM: To investigate the prevalence of the clinical parameters of insulin resistance and diabetes in patients affected by chronic hepatitis C (CHC) or chronic hepatitis B (CHB). METHODS: We retrospectively evaluated 852 consecutive patients (726 CHC and 126 CHB) who had undergone liver biopsy. We recorded age, sex, ALT, type 2 diabetes and/or metabolic syndrome (MS), body mass index (BMI), and apparent disease duration (ADD). RESULTS: Age, ADD, BMI, prevalence of MS and diabetes in patients with mild/moderate liver fibrosis were significantly higher in CHC. However, the degree of steatosis and liver fibrosis evaluated in liver biopsies did not differ between CHC and CHB patients. At multivariate analysis, age, sex, BMI, ALT and diabetes were independent risk factors for liver fibrosis in CHC, whereas only age was related to liver fibrosis in CHB. We also evaluated the association between significant steatosis (>30%) and age, sex, BMI, diabetes, MS and liver fibrosis. Diabetes, BMI and liver fibrosis were associated with steatosis >30% in CHC, whereas only age and BMI were related to steatosis in CHB. CONCLUSION: These data may indicate that hepatitis C virus infection is a risk factor for insulin resistance.

Suppressor of cytokine signaling 3 (SOCS3) expression and hepatitis C virus-related chronic hepatitis: Insulin resistance and response to antiviral therapy.

UNLABELLED: The response to antiviral therapy is lower in hepatitis C virus (HCV) patients with genotype 1 than in those with genotype 2. Overexpression of the suppressor of cytokine signaling 3 (SOCS3) gene in liver tissue is associated with a poorer treatment outcome in patients with chronic hepatitis C viral genotype 1. Also, insulin resistance has been implicated in nonresponse to an anti-HCV treatment. To understand why HCV genotype 1 patients respond differently, we investigated SOCS3 gene expression, metabolic syndrome (MS), and the response to therapy in a cohort of patients with HCV-related hepatitis. A total of 198 patients (108 with genotype 1 and 90 with genotype 2) treated with pegylated interferon plus ribavirin were consecutively enrolled in the study. We measured SOCS3 expression in Epstein-Barr virus-transformed lymphoblastoid cell lines derived from peripheral lymphocytes of a subset of 130 patients. MS was more frequent in genotype 1 patients than in genotype 2 patients (P < 0.01). Nonresponders (P < 0.01), MS (P < 0.001), and genotype 1 (P < 0.001) were significantly related to SOCS3 overexpression. However, SOCS3 levels were higher in nonresponders also, regardless of the genotype (P < 0.01). In a univariate analysis, the genotype (P < 0.001), age (P < 0.001), SOCS3 (P < 0.001), and MS (P < 0.001) were significantly related to the response to therapy. However, in a multivariate analysis, SOCS3 was the only independent predictor of the response (odds ratio = 6.7; P < 0.005). CONCLUSION: We speculate that SOCS3 expression per se may influence the response to antiviral therapy and that the genotype 1b virus might induce its up-regulation. This may account for the different responses to therapy between genotype 1-infected and genotype 2-infected patients.

Interleukin-10 - 1082 GG polymorphism influences the occurrence and the clinical characteristics of hepatitis C virus infection.

BACKGROUND/AIMS: In this study, we determined the genotypic and allelic frequencies of the Interleukin (IL)-10(-1082G/A) IL-10(-592A/C), and IL-10(-819C/T) polymorphisms, and their association with the risk to develop B cell Non Hodgkin Lymphoma (NHL) in hepatitis virus C (HCV) carriers. RESULTS: Genetic polymorphisms in the IL-10 gene promoter were studied in 250 consecutive patients with B-cell NHL with no clinical and/or laboratory findings of cryoglobulinemia, 142 NHL/HCV- and 108 NHL/HCV+ with chronic hepatitis (CH), 120 consecutive subjects with HCV-related CH, and 110 age, sex-matched healthy blood donors. The frequency of the IL-10(-1082GG) genotype vs remaining genotypes (IL-10(-1082GA/AA)) was higher in NHL/HCV+ patients than HCV-related CH patients (P=0.0002, OR=2.89, CI: 1.62-5.15) and in NHL/HCV+ than NHL/HCV- patients (P=0.0001, OR=2.99, CI: 1.72-5.19). Moreover, the IL-10(-1082GG) genotype was more prevalent in indolent NHL/HCV+ cases than aggressive NHL/HCV+ (P=0.0004, OR=4.97, CI: 2.10-11.79). Finally, we confirmed that IL-10(-1082GG) genotype is associated with higher IL-10 production compared to AA homozygous (P=0.037). CONCLUSIONS: The high IL-10 production, due to IL-10(-1082GG) genotype, influences the clinical expression of the HCV infection by increasing susceptibility to develop NHL and might contribute to the indolent form of the disease.

Prevalence and incidence of cryoglobulins in hepatitis C virus-related chronic hepatitis patients: a prospective study.

OBJECTIVE: A high prevalence of cryoglobulins has been reported in patients with hepatitis C virus (HCV)-related liver disease. The aim of this study was to evaluate the prevalence and the incidence of cryoglobulins and their association with clinical symptoms in chronic hepatitis and cirrhosis patients. METHODS: The prevalence of cryoglobulins and cryoglobulinemic syndrome was investigated at enrollment in 237 patients (213 with chronic hepatitis and 24 with cirrhosis). A 7-yr follow-up was conducted evaluating the occurrence of cryoglobulins and/or cryoglobulinemic syndrome every 6 months. Rheumatoid factor was also tested in all patients. RESULTS: Prevalence of rheumatoid factor, cryoglobulins, and cryoglobulinemic syndrome in chronic hepatitis patients were 2%, 0.8%, and 0%, respectively. In cirrhosis patients the prevalence was 4%, 8%, and 0%, respectively. No statistically significant differences were found between the two groups. During the follow-up only one patient for each group abruptly developed cryoglobulinemic syndrome, and none of the patients who showed signs of cryoglobulinemia developed the syndrome or showed signs of evolution of the disease. CONCLUSIONS: Our data demonstrate that the presence of cryoglobulins and/or cryoglobulinemic syndrome in HCV-related liver disease is unusual, as is the occurrence of cryoglobulinemia over time in these patients. This leads us to think that HCV-related cryoglobulinemic syndrome and HCV-related liver disease are independent diseases. This supports new and indirect evidence for an independent and direct role of HCV in liver and blood disorders.

High prevalence of hepatitis G virus infection in Hodgkin's disease and B-cell lymphoproliferative disorders: absence of correlation with hepatitis C virus infection.

BACKGROUND AND OBJECTIVES: During the last decade an epidemiological association between hepatitis C virus (HCV) and B-cell lymphoproliferative disorders (B-LPD) has been reported; the same association has not been observed for Hodgkin's disease (HD). Hepatitis G virus (HGV) shares genetic and biological features with HCV, thus it might also be involved in lymphomagenesis. DESIGN AND METHODS: The aim of this study was to compare the prevalence of HCV and HGV infection in patients at diagnosis of B-LPD or HD. RESULTS: We tested 227 consecutive untransfused patients (127 with B-LPD and 100 with HD) and 110 healthy controls. The prevalence of HCV infection was significantly higher in B-LPD patients than in controls (17.3% vs. 1.8%, p<0.002 ), whereas it was the same in HD patients as in controls. In contrast, the prevalence of HGV was significantly higher in patients, both those with B-LPD (7.8% vs. 0.9%, p<0.03) and those with HD (13% vs. 0.9%, p<0.002), than in controls. Among the various B-LPD tested, HGV infection was more frequent in B-NHL (11.5%). INTERPRETATION AND CONCLUSIONS: Our data support the hypothesis that HGV infection may play a role in lymphomagenesis and that this role is different and separate from that of HCV.