Hepatitis C virus infection and type 1 and type 2 diabetes mellitus

A preliminary analysis of hepatitis C virus in pancreatic islet cells

BACKGROUND

An association between hepatitis C virus (HCV) and type 2 diabetes (T2D) is supported by numerous epidemiologic studies. We hypothesized that HCV could infect human pancreatic islet cells in vitro.

METHODS

Measures of HCV RNA synthesis and protein production were used to evaluate HCV infection of pancreatic islets recovered from human donors.

RESULTS

Significant co-staining of insulin and the HCV entry factor CD81 was observed in pancreatic islets. Positive- and negative-sense HCV RNA were detected in HCV-exposed islets at days 1, 3, 7, and 14 post-infection. The HCV core and NS3 proteins were expressed and increased with time providing further evidence of viral replication. Interferon and an HCV polymerase inhibitor reduced viral replication in islet cells. In HCV-infected islets, TNFα levels were elevated at days 1, 3, and 7 post-infection, while IL-6 levels were elevated at day 1 but not days 3 or 7. Overall, the expression of miR-122 was low in islets compared to the Huh7.5 hepatocyte-derived cell line, although the relative expression of miR-122 increased in islet cells after viral infection (1, 6.63, and 5.83 at days 1, 3, and 7, respectively).

CONCLUSIONS

In this pilot study, viral infection was demonstrated in pancreatic islet cells from multiple donors using complementary measures of viral replication, thus providing evidence of in vitro infection. Altered cytokine expression may contribute to the development of insulin deficiency, and understanding the etiology of diabetes in individuals with HCV infection may facilitate the development of novel treatment modalities and prevention strategies. This in vitro system provides an important model for mechanistic studies of HCV-pancreas interactions and facilitates future studies of the potential impact of viral infection on islet cell function.

The prevalence and association of chronic kidney disease and diabetes in liver cirrhosis using different estimated glomerular filtration rate equation

Background

Chronic kidney disease (CKD) in cirrhosis is one of the dreaded complications associated with a steep rise in mortality and morbidity, including diabetes. There are limited data on the prevalence of CKD and the association with diabetes in outpatients with cirrhosis.

Methodology

This is a cross-sectional study of 7,440 adult liver cirrhosis patients enrolled from August 2001 to April 2010 in a medical center. Case control matching by age and sex with 1,967 pairs, and conditional logistic regression for odds of diabetes was analyzed using adjusted model.

Results

CKD was present in 46.0%, 45.7% and 45.6% of the study population using the MDRD-6, CKD-EPI and MDRD-4 estimated glomerular filtration rate (eGFR) equations, respectively. Using a conditional logistic regression model after adjusting for other risk factors, odds for diabetes increased significantly compared with non-CKD in CKD stage 3 to 5 (stage 3~5) based on MDRD-6–adjusted model, ORs were: stage 3~5, 2.34 (95% CI, 1.78-3.01); MDRD-4–adjusted model, ORs were: stage 3~5, 8.51 (95% CI, 5.63-11.4); CKD-EPI–adjusted model, ORs were: stage 3~5, 8.61 (95% CI, 5.13-13.9).

Conclusion

In cirrhosis patients, prevalence of diabetes was higher in patients with advanced stage of CKD. For patients with cirrhosis, patients with CKD stages 3~5 defined by MDRD-4, MDRD-6, and CKD-EPI eGFR equations had increased risk for diabetes. More severe cirrhosis, indicated by the Child-Turcott-Pugh classification was also accompanied by an increased risk for diabetes.

Cell-autonomous cytotoxicity of type I interferon response via induction of endoplasmic reticulum stress

The interaction of IFN with specific membrane receptors that transduce death-inducing signals is considered to be the principle mechanism of IFN-induced cytotoxicity. In this study, the classic non-cell-autonomous cytotoxicity of IFN was augmented by cell-autonomous mechanisms that operated independently of the interaction of IFN with its receptors. Cells primed to produce IFN by 5-azacytidine (5-aza) underwent endoplasmic reticulum (ER) stress. The chemical chaperones tauroursodeoxycholate (TUDCA) and 4-phenylbutyrate (4-PBA), as well as the iron chelator ciclopirox (CPX), which reduces ER stress, alleviated the cytotoxicity of 5-aza. Ablation of CCAAT-enhancer-binding protein homologous protein (CHOP), the major ER stress-associated proapoptotic transcription factor, protected fibroblasts from 5-aza only when the cytotoxicity was examined cell autonomously. In a medium-transfer experiment in which the cell-autonomous effects of 5-aza was dissociated, CHOP ablation was incapable of modulating cytotoxicity; however, neutralization of IFN receptor was highly effective. Also the levels of caspase activation showed a distinct profile between the cell-autonomous and the medium-transfer experiments. We suggest that besides the classic paracrine mechanism, cell-autonomous mechanisms that involve induction of ER stress also participate. These results have implications in the development of anti-IFN-based therapies and expand the class of pathologic states that are viewed as protein-misfolding diseases.-Mihailidou, C., Papavassiliou, A. G., Kiaris, H. Cell-autonomous cytotoxicity of type I interferon response via induction of endoplasmic reticulum stress.

Improvement in Glycemic Control of Type 2 Diabetes After Successful Treatment of Hepatitis C Virus

OBJECTIVE

Hepatitis C virus (HCV) infection is associated with diabetes and may worsen glycemic control in patients with diabetes. We aimed to investigate whether eradication of HCV infection with direct-acting antiviral (DAA) agents is associated with improved glycemic control in patients with diabetes.

RESEARCH DESIGN AND METHODS

We identified 2,435 patients with diabetes who underwent interferon-free and ribavirin-free DAA-based antiviral treatment for HCV in the national Veterans Affairs health care system. Changes in average hemoglobin A_1c (HbA_1c) level and use of antidiabetic medications 1 year before and after antiviral treatment were compared between patients who achieved sustained virologic response (SVR) and those who did not.

RESULTS

Among patients with elevated baseline HbA_1c, the drop in HbA_1c associated with antiviral treatment was greater in those who achieved SVR (0.98%) than in those who sustained treatment failure (0.65%) (adjusted mean difference 0.34, P = 0.02). Use of antidiabetic medications decreased more in patients who achieved SVR than in those who sustained treatment failure, especially for the use of insulin, which dropped significantly from 41.3% to 38% in patients achieving SVR compared with a slight increase from 49.8% to 51% in those who sustained treatment failure.

CONCLUSIONS

DAA-based eradication of HCV is associated with improved glycemic control in patients with diabetes as evidenced by decreased mean HbA_1c and decreased insulin use. These endocrine benefits of SVR provide additional justification for considering antiviral treatment in all patients with diabetes.

Factors Associated with Improved Glycemic Control by Direct-Acting Antiviral Agent Treatment in Egyptian Type 2 Diabetes Mellitus Patients with Chronic Hepatitis C Genotype 4

BACKGROUND

The association of chronic hepatitis C virus (HCV) infection with type 2 diabetes mellitus (T2DM) was first reported in 1994. Little is known about the effect of direct-acting antiviral agents (DAAs) on glycemic control in T2DM patients. The aim of the present study was to evaluate the factors associated with improved glycemic control (IGC) by DAA treatment in Egyptian T2DM patients with chronic HCV genotype 4 infection.

METHODS

This study included 460 T2DM patients with chronic HCV genotype 4 infection. Four hundred patients received DAAs and 60 patients did not receive DAAs. Patients with sustained virological response after 3 months of DAAs (378 patients) were allocated into two groups: first group included 292 patients (77.2%) with IGC and second group included 86 patients (22.8%) with non-improved glycemic control (NIGC).

RESULTS

In IGC group, 78 patients (26.7%) needed to decrease the dose of antidiabetic treatment. There were no significant differences between IGC and NIGC groups as regards age, sex, and body mass index. The percentage of patients with positive family history of T2DM, those with Child B class and duration of T2DM were significantly higher in NIGC group compared to IGC.

CONCLUSION

Diabetic patients receiving DAAs should be closely monitored for reduction of antidiabetic drugs especially insulin and sulfonylurea to avoid hypoglycemic events. Improvement of glycemic control with DAAs is more in patients without family history of T2DM, short duration of diabetes mellitus, and mild liver disease.

Metformin and daclatasvir: absence of a pharmacokinetic-pharmacodynamic drug interaction in healthy volunteers

AIM

The aim of the present study was to evaluate the effect of the proposed organic cation transporter (OCT) inhibitor daclatasvir on the pharmacokinetics and pharmacodynamics of the OCT substrate metformin.

METHODS

This was an open-label, two-period, randomized, crossover trial in 20 healthy subjects. Treatment A consisted of metformin and treatment B consisted of metformin + daclatasvir. Pharmacokinetic curves were recorded at steady-state. Geometric mean ratios (GMRs) with 90% confidence intervals (CIs) were calculated for metformin area under the concentration-time curve from 0 h to 12 h (AUC_0-12 ), maximum plasma concentration (C_max ) and final plasma concentration (C_last ). An oral glucose tolerance test was performed, measuring insulin, glucose and lactate levels.

RESULTS

The GMRs (90% CI) of metformin AUC_0-12 , C_max and C_last (B vs. A) were 109% (102-116%), 108% (101-116%) and 112% (103-122%). The geometric mean AUC_0-2 for insulin, glucose and lactate during treatments A and B were 84 h^. mEl^-1 and 90 h^. mEl^-1 , 13.6 h^. mmol l^-1 and 13.4 h^. mmol l^-1 , and 3.4 h^. mmol l^-1 and 3.5 h^. mmol l^-1 , respectively.

CONCLUSIONS

Bioequivalence analysis showed that daclatasvir does not influence the pharmacokinetics of metformin in healthy subjects. Pharmacodynamic parameters were also comparable between treatments.

Diabetic aggravation of stroke and animal models

Cerebral ischemia in diabetics results in severe brain damage. Different animal models of cerebral ischemia have been used to study the aggravation of ischemic brain damage in the diabetic condition. Since different disease conditions such as diabetes differently affect outcome following cerebral ischemia, the Stroke Therapy Academic Industry Roundtable (STAIR) guidelines recommends use of diseased animals for evaluating neuroprotective therapies targeted to reduce cerebral ischemic damage. The goal of this review is to discuss the technicalities and pros/cons of various animal models of cerebral ischemia currently being employed to study diabetes-related ischemic brain damage. The rational use of such animal systems in studying the disease condition may better help evaluate novel therapeutic approaches for diabetes related exacerbation of ischemic brain damage.

IL28B gene variants and glucose metabolism in Type 2 Diabetes

Type 2 Diabetes (T2D) develops, when β-cell insulin response fails to compensate for insulin resistance. Recent studies reported associations between the IL28B polymorphisms (rs12979860 and rs8099917) and T2D development in Hepatitis C virus (HCV) patients. To identify possible association with T2D independent from virus infection, we investigated both IL28B polymorphisms in T2D patients and healthy controls (HC). No association was found comparing the genotype and allele frequencies of both IL28B polymorphisms between T2D patients and HC. However, higher glucose levels were found in T2D patients carrying the IL28B CT/TT rs12979860 and GT/GG rs8099917 HCV risk genotypes compared to those with the protective CC and TT genotype (p=0.06 and p=0.02, respectively). Moreover, T2D patients with CT/TT rs12979860 HCV risk genotypes possessed significantly higher HbA1c levels than CC carriers (p=0.04). In conclusion, the IL28B HCV risk genotypes may influence glucose homeostasis in T2D patients without HCV.

Noninvasive Assessment of Liver Fibrosis By Transient Elastography and FIB4/APRI for Prediction of Treatment Response in Chronic Hepatitis C-An Experience from a Tertiary Care Hospital

BACKGROUND

Liver fibrosis and its sequel cirrhosis represent a major health care burden, and assessment of fibrosis by biopsy is gradually being replaced by noninvasive methods. In clinical practice, the determination of fibrosis stage is important, since patients with advanced fibrosis have faster progression to cirrhosis and antiviral therapy is indicated in these patients.

AIMS

To assess the role of transient elastography (TE) and compare it with APRI and FIB4 for predicting liver fibrosis and assessing the effect of host and viral factors on fibrosis and treatment outcome in CHC patients.

METHODS

In a retrospective analysis, 330 CHC patients underwent liver stiffness measurement (LSM) by TE and tests needed for calculating APRI and FIB4 scores at baseline. 228 patients received a combination of Pegylated IFN-based antiviral therapy and were analyzed for therapeutic response.

RESULTS

The study included 330 patients (median age 39 years [range 18-67]), predominantly males (n = 227, 68.8%) with baseline LSMs. The median liver stiffness was 7.8 kPa (range 3.2-69.1 kPa). LSMs and its thresholds for severe fibrosis progression (≥9.5 kPa) and cirrhosis (≥12.5 kPa) were significantly higher in patients with age ≥40 years, diabetes mellitus, and patients with significant alcohol intake (P = 0.003 to P < 0.001). By taking TE as a reference, the diagnostic accuracy of FIB4 scores for predicting cirrhosis (AUROC 0.896) was good (+LR 13.4) compared to APRI (AUROC 0.823) with moderate likelihood ratio (+LR 6.9). Among 228 treated patients the SVR rate in genotype 3 was 70% versus 57.8% in genotype 1. Fibrosis score F4 (P = 0.023) and HCV genotype (P = 0.008) were independent predictors of SVR.

CONCLUSION

The study shows that LSM by TE and fibrosis assessment by FIB4/APRI scores can be used with fair reliability to predict fibrosis and treatment response in patients with CHC infection.

PGC-1α, glucose metabolism and type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a chronic disease characterized by glucose metabolic disturbance. A number of transcription factors and coactivators are involved in this process. Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) is an important transcription coactivator regulating cellular energy metabolism. Accumulating evidence has indicated that PGC-1α is involved in the regulation of T2DM. Therefore, a better understanding of the roles of PGC-1α may shed light on more efficient therapeutic strategies. Here, we review the most recent progress on PGC-1α and discuss its regulatory network in major glucose metabolic tissues such as the liver, skeletal muscle, pancreas and kidney. The significant associations between PGC-1α polymorphisms and T2DM are also discussed in this review.

Markedly Improved Glycemic Control in Poorly Controlled Type 2 Diabetes following Direct Acting Antiviral Treatment of Genotype 1 Hepatitis C

Type 2 diabetes mellitus (T2DM) is often associated with hepatitis C virus (HCV) infection. Successful HCV treatment may improve glycemic control and potentially induce remission of T2DM. We report a case of an obese 52-year-old woman with mixed genotype 1a/1b HCV infection with compensated cirrhosis and a 10-year history of poorly controlled T2DM on insulin therapy. Following successful therapy with sofosbuvir, simeprevir, and ribavirin, her insulin requirements decreased and her glycosylated hemoglobin (HgA1c) normalized despite weight gain. This case suggests an association between HCV and T2DM and the potential for significant improvement in glycemic control with eradication of HCV.

Experimental Neuromyelitis Optica Induces a Type I Interferon Signature in the Spinal Cord

Neuromyelitis optica (NMO) is an acute inflammatory disease of the central nervous system (CNS) which predominantly affects spinal cord and optic nerves. Most patients harbor pathogenic autoantibodies, the so-called NMO-IgGs, which are directed against the water channel aquaporin 4 (AQP4) on astrocytes. When these antibodies gain access to the CNS, they mediate astrocyte destruction by complement-dependent and by antibody-dependent cellular cytotoxicity. In contrast to multiple sclerosis (MS) patients who benefit from therapies involving type I interferons (I-IFN), NMO patients typically do not profit from such treatments. How is I-IFN involved in NMO pathogenesis? To address this question, we made gene expression profiles of spinal cords from Lewis rat models of experimental neuromyelitis optica (ENMO) and experimental autoimmune encephalomyelitis (EAE). We found an upregulation of I-IFN signature genes in EAE spinal cords, and a further upregulation of these genes in ENMO. To learn whether the local I-IFN signature is harmful or beneficial, we induced ENMO by transfer of CNS antigen-specific T cells and NMO-IgG, and treated the animals with I-IFN at the very onset of clinical symptoms, when the blood-brain barrier was open. With this treatment regimen, we could amplify possible effects of the I-IFN induced genes on the transmigration of infiltrating cells through the blood brain barrier, and on lesion formation and expansion, but could avoid effects of I-IFN on the differentiation of pathogenic T and B cells in the lymph nodes. We observed that I-IFN treated ENMO rats had spinal cord lesions with fewer T cells, macrophages/activated microglia and activated neutrophils, and less astrocyte damage than their vehicle treated counterparts, suggesting beneficial effects of I-IFN.

The core of hepatitis C virus pathogenesis

Capsid proteins form protective shells around viral genomes and mediate viral entry. However, many capsid proteins have additional and important roles for virus infection and in modulating cellular response to infection, with important consequences on pathogenesis. Infection by the Hepatitis C virus (HCV) can lead to liver steatosis, cirrhosis, and hepatocellular carcinoma. Herein, we focus on the role in pathogenesis of Core, the capsid protein of the HCV.

Psychological disorders and oral lichen planus: matched case-control study and literature review

OBJECTIVE

Oral lichen planus (OLP) may be linked to psychological disorders. This study investigated psychological factors associated with OLP.

METHODS

A case-control study with incident OLP case patients and age-gender-socio-economic status-matched controls, recruited from among relatives, accompanying persons, and departmental staff, investigated psychological traits using the Psychological General Well-Being Index-Short form. Common factor analysis was used to generate a set of psychological dimensions. The association between these dimensions and OLP adjusted for confounders (education, number of lifetime sexual partners, drinking-smoking) and interactions was assessed through conditional logistic regression and odds ratios (OR) were estimated.

RESULTS

A total of 67 case-control pairs were recruited. Psychological dimensions generated were: dimension-1 (anxiety, low vitality), dimension-2 (negative well-being, low vitality), dimension-3 (depressed mood, low self-control). The ORs for OLP were, dimension-1, 1.0 (95% confidence interval -95CI, 0.3-2.6); dimension-2, 0.5 (95CI, 0.2-1.2); dimension-3, 4.8 (95CI, 1.8-12.9). Dimension-3 was highly associated with mild, but not associated with severe, OLP. Literature searching provided 21 studies, with anxiety and depression principally associated with OLP.

CONCLUSIONS

Depressed mood and low self-control were highly associated with OLP, particularly the reticular-papular forms. These traits could have a causative role in OLP development-progression, but further investigations are necessary.

Risk of de novo post-transplant type 2 diabetes in patients undergoing liver transplant for non-alcoholic steatohepatitis

Background

Non-alcoholic steatohepatitis (NASH) is often seen together with components of metabolic syndrome. The aim of this study was to assess the risk of de novo post-transplant type 2 diabetes (DM) in liver transplant recipients with NASH.

Methods

All adult patients from the Scientific Registry of Transplant Recipients (2003–2012) transplanted for NASH or cryptogenic cirrhosis (the NASH cohort) without pre-transplant DM were included in this retrospective cross-sectional study.

Results

Total 2,916 NASH subjects and 14,268 controls with non-HCV related cirrhosis or hepatocellular carcinoma were included. Patients with NASH were, on average, 6 years older, more likely female and overweight/obese. By 5 years post-transplant, 39.8 % NASH vs. 27.0 % controls developed at least one onset of de novo DM; this was observed starting 6 months post-transplant: 22.9 % vs. 16.7 % (relative risk 1.38). Later in follow-up, the relative risk of de novo DM was also higher in NASH: 1.46 by 3 years, 1.47 by 5 years (all p < 0.0001). After exclusion of DM that resolved after the first year, long-term DM remained higher in the NASH cohort: 7.6 % vs. 4.3 %, p < 0.0001. In multivariate analysis, after adjustment for confounders including the use of immunosuppressants, having NASH was independently associated with development of de novo post-transplant DM: adjusted hazard ratio (95 % CI) = 1.29 (1.18–1.42), p < 0.0001.

Conclusions

Liver transplant recipients with NASH have a higher risk of de novo post-transplant DM. This suggests the presence of an underlying metabolic disorder beyond fatty liver that may be causative for both NASH and type 2 diabetes.

Diabetes mellitus and renal involvement in chronic viral liver disease

HYPOTHESIS

Chronic viral liver disease is often associated with other conditions. Diabetes mellitus (DM) is frequently reported in this context and may play a role in the progression of the liver disease to hepatocellular carcinoma (HCC). Renal disease is also an important extrahepatic manifestation of hepatitis viral infection and its presence is associated with poor prognosis and management issues.

OBJECTIVES

Our study had multiple purposes: to determine the frequency of the association between chronic viral liver disease and diabetes mellitus, evaluate the potential of diabetes mellitus as a risk factor for HCC and assess an eventual renal involvement.

METHODS AND RESULTS

We included in our study a number of 246 patients with chronic liver disease, from whom 136 were diagnosed with chronic viral hepatitis and 110 with viral liver cirrhosis. These patients were assessed by using a clinical examination and a series of tests, including serum transaminase levels, serum bilirubin, serum albumin, markers of cholestasis, fasting plasma glucose levels, serum creatinine, urea, albuminuria, Addis-Hamburger test, electrophoresis of urinary proteins, abdominal ultrasound and, in some cases, CT examination. We obtained the following results: diabetes mellitus is often associated with chronic liver disease of viral etiology, having been identified in 18.29% of the patients in our study. Age above 60 in patients with chronic hepatitis (p=0.013<0.05) and presence of hepatitis C virus were particularly correlated with the presence of diabetes mellitus. Renal disease was present in 13.4% of the patients with chronic liver disease and it was especially associated with liver cirrhosis and hepatitis C virus. The most common form of renal injury was glomerulonephritis. Acute kidney injury was diagnosed only in cirrhotic patients as hepatorenal syndrome, occurring in 7.27% of the subjects, while chronic kidney disease was identified only in two cases of chronic viral hepatitis. Four patients in our study were diagnosed with HCC and none of them presented diabetes mellitus.

DISCUSSION

Our study revealed that there is a significant association between diabetes mellitus and chronic viral liver disease induced by hepatitis C virus. Glomerulonephritis was the most common type of renal disease in both hepatitis patients and in those with cirrhosis. Glomerular injury was strongly correlated with the presence of hepatitis C virus than with hepatitis B virus. A connection between diabetes mellitus and hepatocellular carcinoma could not be established.

Statin Use Is Associated With Incident Diabetes Mellitus Among Patients in the HIV Outpatient Study

INTRODUCTION

Statin therapy is effective in the prevention of cardiovascular disease in the general population but has been shown to modestly increase the risk for incident diabetes mellitus (DM).

METHODS

We analyzed incident DM in HIV Outpatient Study (HOPS) participants followed at 8 HIV clinic sites during 2002-2011, comparing rates among those who initiated statin therapy during that period with those who did not. Using Cox proportional hazards models, we examined the association between cumulative years of statin exposure and the risk of developing DM, after controlling for age, sex, race/ethnicity, antiretroviral history, prevalent hepatitis C, body mass index, and cumulative exposure to protease inhibitor therapy. We also adjusted for propensity scores to account for residual confounding by indication.

RESULTS

Of 4692 patients analyzed, 590 (12.6%) initiated statin therapy and 355 (7.2%) developed DM. Incident DM was independently associated with statin therapy (adjusted hazard ratio, 1.14 per year of statin use), as well as older age, Hispanic/Latino ethnicity, non-Hispanic/Latino black race, antiretroviral-naive status, prevalent hepatitis C, and body mass index ≥30 kg/m² (P < 0.05 for all). The association of statin use with incident DM was similar in the model adjusted for propensity score.

CONCLUSIONS

Statin use was associated with a modestly increased risk of incident DM in an HIV-infected population, similar to existing data for the general population. HIV-infected patients should be monitored for glucose intolerance, but statins should not be withheld if clinically indicated for cardiovascular disease risk reduction.

Improper sharp disposal practices among diabetes patients in home care settings: Need for concern?

In the recent years, outbreaks of blood-borne infections have been reported from assisted living facilities, which were traced back to improper blood glucose monitoring practices. Needle-stick injuries have been implicated in many such cases. This directly raises concerns over sharp disposal practices of diabetic patients self-managing their condition in home care settings. With India being home to a huge diabetic population, this issue, if neglected, can cause substantial damage to the health of the population and a marked economic loss. This article discusses the sharp disposal practices prevalent among diabetes patients, the importance of proper sharp disposal, barriers to safe disposal of sharps, and the options available for doing the same. For adopting an environmentally safe wholesome approach, disposal of plastics generated as a result of diabetes self-care at home is important as well. The article also looks at the possible long-term solutions to these issues that are sustainable in an Indian context.

Management of patients with hepatitis C infection and renal disease

Hepatitis C virus (HCV) infection in patients with end-stage renal disease (ESRD) is associated with more rapid liver disease progression and reduced renal graft and patients' survival following kidney transplantation. Evaluations and management of HCV in patients with renal disease are challenging. The pharmacokinetics of interferons (IFN), ribavirin (RBV) and some direct acting antiviral (DAA), such as sofosbuvir, are altered in patients with ESRD. With dose adjustment and careful monitoring, treatment of HCV in patients with ESRD can be associated with sustained virological response (SVR) rates nearly comparable to that of patients with normal renal function. DAA-based regimens, especially the IFN-free and RBV-free regimens, are theoretically preferred for patients with ESRD and KT in order to increase SVR rates and to reduce treatment side effects. However, based on the data for pharmacokinetics, dosing safety and efficacy of DAA for patients with severe renal impairment are lacking. This review will be focused on the evaluations, available pharmacologic data, and management of HCV in patients with severe renal impairment, patients who underwent KT, and those who suffered from HCV-related renal disease, according to the available treatment options, including DAA.

Inhibition of IRS-1 by hepatitis C virus infection leads to insulin resistance in a PTEN-dependent manner

Background

Hepatitis C virus (HCV) infection was recently recognized as an independent risk factor for insulin resistance (IR), the onset phase of type 2 diabetes mellitus (T2DM). Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) negatively regulates PI3K/Akt signaling pathway, which is critical for IR development and progression of cirrhosis to hepatocellular carcinoma (HCC). Here, we investigate the role of PTEN in HCV-associated IR and explored the mechanisms by which HCV regulates PTEN.

Methods

Western blotting was used to detect the levels of insulin signaling pathway components, including insulin receptor substrate-1 (IRS-1), phosphorylated IRS-1 (pIRS-1) at serine 307 (Ser307), both phosphorylated Akt (pAkt) and total Akt. A time-course experiment measuring activation of the insulin signaling pathway was performed to assess the effect of HCV infection on insulin sensitivity by examining the phosphorylation levels of Akt and GSK3β, a downstream target of Akt. Huh7.5.1 cells were transduced with a lentiviral vector expressing PTEN or PTEN shRNA, and IRS-1 and pIRS-1 (Ser307) levels were determined in both HCV-infected and uninfected cells. The pc-JFH1-core plasmid was constructed to explore the underlying mechanisms by which HCV regulated PTEN and therefore IRS-1 levels.

Results

HCV infection inhibited the insulin signaling pathway by reducing the levels of IRS-1 and pAkt/Akt while increasing phosphorylation of IRS-1 Ser307. In addition, HCV infection decreased the sensitivity to insulin-induced stimulation by inhibiting Akt and GSK3β phosphorylation. Furthermore, PTEN mRNA and protein levels were reduced upon HCV infection as well as transfection with the pc-JFH1-core plasmid. The reduction in IRS-1 level observed in HCV-infected cells was rescued to a limited extent by overexpression of PTEN, which in turn slightly reduced pIRS-1 (Ser307) level. In contrast, IRS-1 level were significantly decreased and phosphorylation of IRS-1 at Ser-307 was strongly enhanced by PTEN knockdown, suggesting that both reduction in IRS-1 level and increase in IRS-1 phosphorylation at Ser307 upon HCV infection occurred in a PTEN-dependent manner.

Conclusions

HCV infection suppresses the insulin signaling pathway and promotes IR by repressing PTEN, subsequently leading to decreased levels of IRS-1 and increased levels of pIRS-1 at Ser307. The findings provide new insight on the mechanism of HCV-associated IR.