Association among Fas expression in leucocytes, serum Fas and Fas-ligand concentrations and hepatic inflammation and fibrosis in chronic hepatitis C

Single nucleotide polymorphisms of CXCL9-11 chemokines are associated with liver fibrosis in HIV/HCV-coinfected patients

BACKGROUND

CXCR3A-associated chemokines (CXCL9-11) are implicated in the pathogenesis of hepatitis C virus (HCV) infection. We analyzed the association between CXCL9-11 polymorphisms and significant liver fibrosis in human immunodeficiency virus (HIV)/HCV-coinfected patients.

METHODS

We performed a cross-sectional study in 220 patients who were genotyped for CXCL9-11 polymorphisms (CXCL9 rs10336, CXCL10 rs3921, and CXCL11 rs4619915) using GoldenGate assay. Three outcome variables related to liver fibrosis were studied: (1) F ≥ 2; (2) APRI ≥ 2; and (3) FIB-4 ≥ 3.25.

RESULTS

The percentage of patients with significant liver fibrosis (F ≥ 2, APRI ≥ 2, and FIB-4 ≥ 3.25) was significantly higher for CXCL9 rs10336 TT (P = 0.046, P = 0.010, and P = 0.046, respectively), CXCL10 rs3921 GG (P = 0.046, P = 0.011, and P = 0.049, respectively), and CXCL11 rs4619915 AA (P = 0.035, P = 0.014, and P = 0.057, respectively) genotypes. Moreover, the greater likelihood of having significant liver fibrosis (F ≥ 2, APRI ≥ 2, and FIB-4 ≥ 3.25) was found in carriers of CXCL9 rs10336 TT and CXCL10 rs3921 GG [adjusted odds ratio (aOR) > 2 (P < 0.05)]. These trends were significantly more pronounced in patients infected with HCV-genotype 1 (GT1) [aOR > 3 (P < 0.05)]. Moreover, TGA haplotype showed higher odds for having values of APRI ≥ 2 (aOR = 2.4; P = 0.012) when we considered all patients. This elevated risk for significant liver fibrosis was better represented in patients infected with HCV-GT1, where TGA haplotype had increased odds for having values of F ≥ 2 (aOR = 1.9; P = 0.045), APRI ≥ 2 (aOR = 3.2; P = 0.009), and FIB-4 ≥ 3.25 (aOR = 3.3; P = 0.026).

CONCLUSIONS

The homozygosity for the minor alleles CXCL9 rs10336 (T), CXCL10 rs3921 (G), and CXCL11 rs4619915 (A) is associated with the higher likelihood of significant liver fibrosis in HIV-infected patients coinfected with HCV-GT1.

Increased expression of Fas receptor and Fas ligand in the culture of the peripheral blood mononuclear cells stimulated with Borrelia burgdorferi sensu lato

Apoptosis of the lymphocytes plays an essential role in the regulation of inflammatory/immune responses and its abnormalities may contribute to a chronic infection, persistent inflammation and autoimmunity. Its role in the pathogenesis of the late Lyme borreliosis manifestations has not been studied so far. We have measured Th lymphocyte apoptosis rate, membrane expression of pro-apoptotic Fas receptor, and supernatant concentrations of selected soluble pro- and anti-apoptotic mediators in cultures of peripheral blood mononuclear cells from 16 patients with disseminated Lyme borreliosis (6 with osteoarticular symptoms, 7 with neuroborreliosis and 3 with acrodermatitis chronica atrophicans) and 8 healthy controls. The cultures stimulated for 48h with live Borrelia burgdorferi sensu stricto, B. garinii or B. afzelii spirochetes. Fraction of the apoptotic Th (CD3+CD4+) lymphocytes and expression of Fas in this cell population was measured cytometrically and concentrations of soluble Fas, soluble Fas ligand, IL-10, IL-12 and TGF-β in culture supernatant with ELISA assays. The expression of IL-10, soluble and membrane Fas and soluble Fas ligand was increased under stimulation and higher in the presence of B. burgdorferi sensu stricto than the other species. Apoptosis rate was not affected. There was no difference between Lyme borreliosis patients and controls. IL-10 concentration correlated negatively with the membrane Fas expression and apoptosis under stimulation with B. afzelii and B. garinii. Expression of Fas/FasL system is up-regulated under stimulation with B. burgdorferi, but without corresponding increase in lymphocyte apoptosis. Variable responses observed with different B. burgdorferi species may reflect differences in the pathogenesis of the infection in vivo.

Serum cytochrome c and m30-neoepitope of cytokeratin-18 in chronic hepatitis C

BACKGROUND & AIMS

Cytochrome c (CYC) and M30-neoepitope of cytokeratin-18 (M30-CK18) are involved at different levels in apoptotic pathways. We aimed to evaluate an association between serum CYC, M30-CK18 and disease activity as well response to therapy in chronic hepatitis C (CHC).

METHODS

Seventy CHC patients were enrolled in this study. Forty five of them completed pegylated interferon plus ribavirin therapy. Histopathological evaluation of hepatic inflammatory activity and fibrosis, as well as blood liver function tests, was performed. Serum concentrations of M30-CK18 and CYC were measured by ELISA.

RESULTS

Median serum concentration of M30-CK18 was higher in CHC patients [283 U/L] vs. control [113 U/L] (P = 0.0003) and was associated with inflammatory activity and liver fibrosis (P < 0.001). Serum M30-CK18 positively correlated with serum activity of ALT and GGT. CYC was not detected in sera of control group, whereas in CHC, 41.43% patients had detectable CYC in serum samples [0.60 ng/ml]. Detectable baseline serum CYC had been negatively associated with sustained virological response (SVR). In patients with detectable CYC, SVR rate was 20% vs. 60% in patients with undetectable CYC (P = 0.007).

CONCLUSIONS

Elevated serum M30-CK18, as an indicator of enhanced apoptosis of hepatocytes, parallels active hepatic inflammation and fibrosis but also biochemical activity in CHC; thus, it may serve as a comprehensive non-invasive marker of disease activity. On the other hand, detection of serum CYC at baseline may be negatively associated with treatment response to pegylated interferon plus ribavirin in CHC.

Serum apoptosis markers related to liver damage in chronic hepatitis C: sFas as a marker of advanced fibrosis in children and adults while M30 of severe steatosis only in children

Background

Liver biopsy represents the gold standard for evaluating damage and progression in patients with chronic hepatitis C (CHC); however, developing noninvasive tests that can predict liver injury represents a growing medical need. Considering that hepatocyte apoptosis plays a role in CHC pathogenesis; the aim of our study was to evaluate the presence of different apoptosis markers that correlate with liver injury in a cohort of pediatric and adult patients with CHC.

Methods

Liver biopsies and concomitant serum samples from 22 pediatric and 22 adult patients with CHC were analyzed. Histological parameters were evaluated. In serum samples soluble Fas (sFas), caspase activity and caspase-generated neoepitope of the CK-18 proteolytic fragment (M30) were measured.

Results

sFas was associated with fibrosis severity in pediatric (significant fibrosis p = 0.03, advanced fibrosis p = 0.01) and adult patients (advanced fibrosis p = 0.02). M30 levels were elevated in pediatric patients with severe steatosis (p = 0.01) while in adults no relation with any histological variable was observed. Caspase activity levels were higher in pediatric samples with significant fibrosis (p = 0.03) and they were associated with hepatitis severity (p = 0.04) in adult patients. The diagnostic accuracy evaluation demonstrated only a good performance for sFas to evaluate advanced fibrosis both in children (AUROC: 0.812) and adults (AUROC: 0.800) as well as for M30 to determine steatosis severity in children (AUROC: 0.833).

Conclusions

Serum sFas could be considered a possible marker of advanced fibrosis both in pediatric and adult patient with CHC as well as M30 might be a good predictor of steatosis severity in children.

Altered of apoptotic markers of both extrinsic and intrinsic pathways induced by hepatitis C virus infection in peripheral blood mononuclear cells

Background

Chronic hepatitis C (CHC) has emerged as a leading cause of cirrhosis in the U.S. and across the world. To understand the role of apoptotic pathways in hepatitis C virus (HCV) infection, we studied the mRNA and protein expression patterns of apoptosis-related genes in peripheral blood mononuclear cells (PBMC) obtained from patients with HCV infection.

Methods

The present study included 50 subjects which plasma samples were positive for HCV, but negative for human immunodeficiency virus (HIV) or hepatitis B virus (HBV). These cases were divided into four groups according to METAVIR, a score-based analysis which helps to interpret a liver biopsy according to the degree of inflammation and fibrosis. mRNA expression of the studied genes were analyzed by reverse transcription of quantitative polymerase chain reaction (RT-qPCR) and protein levels, analyzed by ELISA, was also conducted. HCV genotyping was also determined.

Results

HCV infection increased mRNA expression and protein synthesis of caspase 8 in group 1 by 3 fold and 4 fold, respectively (p < 0.05). In group 4 HCV infection increased mRNA expression and protein synthesis of caspase 9 by 2 fold and 1,5 fold, respectively (p < 0.05). Also, caspase 3 mRNA expression and protein synthesis had level augumented by HCV infection in group 1 by 4 fold and 5 fold, respectively, and in group 4 by 6 fold and 7 fold, respectively (p < 0.05).

Conclusions

HCV induces alteration at both genomic and protein levels of apoptosis markers involved with extrinsic and intrinsic pathways.

Hepatitis C virus entry: role of host and viral factors

Hepatitis C virus (HCV) has been considered to be a significant risk factor in developing liver associated diseases including hepatocellular carcinoma all over the world. HCV is an enveloped positive strand virus comprising a complex between genomic RNA and viral envelope glycoproteins (E1 and E2), which are anchored within host derived double-layered lipid membrane surrounding the nucleocapsid composed of several copies of core protein. HCV cell entry is the first step in infection and viral replication into host cells mainly hepatocytes. HCV cell entry is a complex process involving both the viral (envelope glycoproteins E1/E2) and host factors (cellular receptors and associated factors i.e. CD81, SR-BI, LDL-R, CLDN1, Occludin, DC-SIGN, L-SIGN and Glycosaminoglycans). Besides these the expression of certain other conditions such as polarization and EWI-2 expression inhibits the viral cell entry. Exploring the mechanism of HCV entry will help to better understand the viral life cycle and possible therapeutic targets against HCV infection including viral and host factors involved in this process. New strategies such as RNAi represents a new option for targeting the host or viral factors for prevention and therapeutic against HCV infection. In the current review we try to summarize the current knowledge about mechanism and interaction of cellular and viral factors involved in HCV cell entry and its implication as therapeutic target to inhibit HCV infection.

Characterization of chronic HCV infection-induced apoptosis

Background

To understand the complex and largely not well-understood apoptotic pathway and immune system evasion mechanisms in hepatitis C virus (HCV)-associated hepatocellular carcinoma (HCC) and HCV associated chronic hepatitis (CH), we studied the expression patterns of a number of pro-apoptotic and anti-apoptotic genes (Fas, FasL, Bcl-2, Bcl-xL and Bak) in HepG2 cell line harboring HCV- genotype-4 replication. For confirmation, we also assessed the expression levels of the same group of genes in clinical samples obtained from 35 HCC and 34 CH patients.

Methods

Viral replication was assessed in the tissue culture medium by RT-PCR, quantitative Real-Time PCR (qRT-PCR); detection of HCV core protein by western blot and inhibition of HCV replication with siRNA. The expression level of Fas, FasL, Bcl-2, Bcl-xL and Bak was assessed by immunohistochemistry and RT-PCR whereas caspases 3, 8 and 9 were assessed by colorimetric assay kits up to 135 days post infection.

Results

There was a consistent increase in apoptotic activity for the first 4 weeks post-CV infection followed by a consistent decrease up to the end of the experiment. The concordance between the changes in the expression levels of Fas, FasL, Bcl-2, Bcl-xL and Bak in vitro and in situ was statistically significant (p < 0.05). Fas was highly expressed at early stages of infection in cell lines and in normal control liver tissues followed by a dramatic reduction post-HCV infection and an increase in the expression level of FasL post HCV infection. The effect of HCV infection on other apoptotic proteins started very early post-infection, suggesting that hepatitis C modulating apoptosis by modulating intracellular pro-apoptotic signals.

Conclusions

Chronic HCV infection differently modulates the apoptotic machinery during the course of infection, where the virus induces apoptosis early in the course of infection, and as the disease progresses apoptosis is modulated. This study could open a new opportunity for understanding the various signaling of apoptosis and in the developing a targeted therapy to inhibit viral persistence and HCC development.