Lipids and HCV

Biomarkers of Hepatic Toxicity: An Overview

Background

Hepatotoxicity is the foremost issue for clinicians and the primary reason for pharmaceutical product recalls. A biomarker is a measurable and quantifiable attribute used to evaluate the efficacy of a treatment or to diagnose a disease. There are various biomarkers which are used for the detection of liver disease and the intent of liver damage.

Objective

This review aims to investigate the current state of hepatotoxicity biomarkers and their utility in clinical settings. Using hepatic biomarkers, the presence of liver injury, its severity, prognosis, causative agent, and type of hepatotoxicity can all be determined.

Methods

Relevant published articles up to 2022 were systematically retrieved from MEDLINE/PubMed, SCOPUS, EMBASE, and WOS databases using keywords such as drug toxicity, hepatotoxicity biomarkers, biochemical parameters, and nonalcoholic fatty liver disease.

Results

In clinical trials and everyday practice, biomarkers of drug-induced liver injury are essential for spotting the most severe cases of hepatotoxicity. Hence, developing novel biomarker approaches to enhance hepatotoxicity diagnosis will increase specificity and/or identify the person at risk. Importantly, early clinical studies on patients with liver illness have proved that some biomarkers such as aminotransferase, bilirubin, albumin, and bile acids are even therapeutically beneficial.

Conclusions

By assessing the unique signs of liver injury, health care professionals can rapidly and accurately detect liver damage and evaluate its severity. These measures contribute to ensuring prompt and effective medical intervention, hence reducing the risk of long-term liver damage and other major health concerns.

Biomarkers in Detection of Hepatitis C Virus Infection

The hepatitis C virus (HCV) infection affects 58 million people worldwide. In the United States, the incidence rate of acute hepatitis C has doubled since 2014; during 2021, this increased to 5% from 2020. Acute hepatitis C is defined by any symptom of acute viral hepatitis plus either jaundice or elevated serum alanine aminotransferase (ALT) activity with the detection of HCV RNA, the anti-HCV antibody, or hepatitis C virus antigen(s). However, most patients with acute infection are asymptomatic. In addition, ALT activity and HCV RNA levels can fluctuate, and a delayed detection of the anti-HCV antibody can occur among some immunocompromised persons with HCV infection. The detection of specific biomarkers can be of great value in the early detection of HCV infection at an asymptomatic stage. The high rate of HCV replication (which is approximately 1010 to 1012 virions per day) and the lack of proofreading by the viral RNA polymerase leads to enormous genetic diversity, creating a major challenge for the host immune response. This broad genetic diversity contributes to the likelihood of developing chronic infection, thus leading to the development of cirrhosis and liver cancer. Direct-acting antiviral (DAA) therapies for HCV infection are highly effective with a cure rate of up to 99%. At the same time, many patients with HCV infection are unaware of their infection status because of the mostly asymptomatic nature of hepatitis C, so they remain undiagnosed until the liver damage has advanced. Molecular mechanisms induced by HCV have been intensely investigated to find biomarkers for diagnosing the acute and chronic phases of the infection. However, there are no clinically verified biomarkers for patients with hepatitis C. In this review, we discuss the biomarkers that can differentiate acute from chronic hepatitis C, and we summarize the current state of the literature on the useful biomarkers that are detectable during acute and chronic HCV infection, liver fibrosis/cirrhosis, and hepatocellular carcinoma (HCC).

Proprotein convertase subtisilin/kexin 9 levels decline with hepatitis C virus therapy in people with HIV/hepatitis C virus and correlate with inflammation

BACKGROUND

Proprotein convertase subtisilin/kexin 9 (PCSK9) raises low-density lipoprotein cholesterol (LDL-C) levels and is associated with inflammation, which is elevated in HIV and hepatitis C virus (HCV) infection. We compared PCSK9 levels in people with co-occurring HIV and HCV (HIV/HCV) vs. HIV alone, and evaluated the impact of HCV direct-acting antiviral (DAA) therapy on PCSK9.

DESIGN

A prospective, observational cohort study.

METHODS

Thirty-five adults with HIV/HCV and 37 with HIV alone were evaluated, all with HIV virologic suppression and without documented cardiovascular disease. Circulating PCSK9 and inflammatory biomarkers were measured at baseline and following HCV treatment or at week 52 (for HIV alone) and compared using Wilcoxon tests and Spearman correlations.

RESULTS

At baseline, PCSK9 trended higher in HIV/HCV vs. HIV alone (307 vs. 284 ng/ml, P  = 0.06). Twenty-nine participants with HIV/HCV completed DAA therapy with sustained virologic response. PCSK9 declined from baseline to posttreatment 1 (median 7.3 weeks after end of therapy [EOT]) and posttreatment 2 (median 43.5 weeks after EOT), reaching levels similar to HIV alone; median within-person reduction was -60.5 ng/ml ( P  = 0.003) and -55.6 ng/ml ( P  = 0.02), respectively. Decline in PCSK9 correlated with decline in soluble (s)E-selectin and sCD163 ( r  = 0.64, P  = 0.002; r  = 0.58, P  = 0.008, respectively), but not with changes in LDL-C or other biomarkers. No significant change in PCSK9 occurred in the HIV alone group over 52 weeks.

CONCLUSION

PCSK9 declined with DAA therapy in participants with HIV/HCV, correlating with declines in several inflammatory biomarkers but not LDL-C. Elevated PCSK9 with HCV may be linked to particular HCV-associated inflammatory pathways more so than cholesterol homeostasis.

Akt1 is involved in HCV release by promoting endoplasmic reticulum-to-endosome transition of infectious virions

AIMS

Hepatitis C virus (HCV) relies on the viral and host factors to complete its life cycle. It has evolved to profit from Akt activation at some stage in its life cycle through various mechanisms, notably by activating lipogenesis, which is crucial for infectious virions production.

MATERIALS AND METHODS

By employing an Akt-specific inhibitor, the impact of Akt on intracellular and extracellular infectivity was investigated. To ascertain the role of Akt in the HCV life cycle, the two-part cell culture-derived HCV infection protocol utilizing Akt1 small interfering RNAs (siRNAs) was implemented. The impact of Akt1 on intracellular HCV transition was determined using membrane flotation assay and proximity ligation assay coupled with Anti-Rab7 immunoprecipitation and immunofluorescence.

KEY FINDINGS

Akt1 silencing reduced infectious virions release to a degree comparable to that of ApoE, a host component involved in the HCV assembly and release, suggesting Akt1 was critical in the late stage of the HCV life cycle. Extracellular infectivity of HCV was inhibited by brefeldin A, and the inhibitory effect was augmented by Akt1 silencing and partially restored by ectopic Akt1 expression. Immunofluorescence revealed that Akt1 inhibition suppressed the interaction between HCV core protein and lipid droplet. Akt1 silencing impeded the transition of HCV from the endoplasmic reticulum to the endosome and hence inhibited the secretion of HCV infectious virions from the late endosome.

SIGNIFICANCE

Our study demonstrates that Akt1 has an impact on the lipogenesis pathway and plays a critical role in the assembly and secretion of infectious HCV.

Apolipoprotein E and viral infection: Risks and Mechanisms

Apolipoprotein E (ApoE) is a multifunctional protein critical for lipid metabolism and cholesterol homeostasis. In addition to being a well known genetic determinant of both neurodegenerative and cardiovascular diseases, ApoE is frequently involved in various viral infection-related diseases. Human ApoE protein is functionally polymorphic with three isoforms, namely, ApoE2, ApoE3, and ApoE4, with markedly altered protein structures and functions. ApoE4 is associated with increased susceptibility to infection with herpes simplex virus type-1 and HIV. Conversely, ApoE4 protects against hepatitis C virus and hepatitis B virus infection. With the outbreak of coronavirus disease 2019, ApoE4 has been shown to determine the incidence and progression of severe acute respiratory syndrome coronavirus 2 infection. These findings clearly indicate the critical role of ApoE in viral infection. Furthermore, ApoE polymorphism has various or even opposite effects in these infection processes, which are partly related to the structural features that distinguish the different ApoE statuses. In the current review, we summarize the emerging relationship between ApoE and viral infection, discuss the potential mechanisms, and identify future directions that may help to advance our understanding of the link between ApoE and viral infection.

Association of low HDL-c levels with severe symptoms and poor clinical prognosis in patients with severe fever and thrombocytopenia syndrome

Background

Severe fever with thrombocytopenia syndrome (SFTS) is an acute infectious disease caused by a novel bunyavirus, characterized by high fever, thrombocytopenia, and multiple organ damage. Disturbances in lipid metabolism often occur during viral infections, but the changes and clinical significance of lipid profiles in SFTS patients remain unclear. This study aimed to investigate the alterations in lipid profiles and their clinical significance in SFTS patients.

Methods

A total of 157 SFTS patients and 157 healthy controls were enrolled in this study. Serum lipid levels were collected and analyzed among different groups and prognosis categories. Receiver operating characteristic (ROC) curve analysis was performed to assess the ability of lipid levels in distinguishing between severe and mild cases, as well as surviving and non-surviving patients. Pearson correlation analysis was used to examine the associations between lipid levels and clinical laboratory parameters.

Results

SFTS patients exhibited significantly lower levels of HDL-c, LDL-c, cholesterol, APoAI, and ApoB compared to healthy controls, while triglyceride levels were significantly higher. Serum HDL-c and ApoAI demonstrated good performance as indicators for distinguishing between survivors and non-survivors (AUC of 0.87 and 0.85, respectively). Multivariate regression analysis indicated that HDL-c independently acts as a protective factor in patients with SFTS. HDL-c levels showed decline in non-survivors but recovered in survivors. Moreover, HDL-c exhibited significant correlations with various clinical laboratory parameters (IL-6, CRP, AST, TT, APTT, PLT, ALB, and CD4).

Conclusion

This study identified abnormalities in serum lipid metabolism among SFTS patients. HDL-c and ApoAI levels hold potential as biomarkers for distinguishing survivors from non-survivors. Additionally, HDL-c and ApoAI may serve as therapeutic targets for the management of SFTS patients.

HCV Core Protein-ISX Axis Promotes Chronic Liver Disease Progression via Metabolic Remodeling and Immune Suppression

Chronic hepatitis C virus (HCV) infection is an important public health issue. However, knowledge on how the virus remodels the metabolic and immune response toward hepatic pathologic environment is limited. The transcriptomic and multiple evidences reveal that the HCV core protein-intestine-specific homeobox (ISX) axis promotes a spectrum of metabolic, fibrogenic, and immune modulators (e.g., kynurenine, PD-L1, and B7-2), regulating HCV-infection relevant pathogenic phenotype in vitro and in vivo. In a transgenic mice model, the HCV core protein-ISX axis enhance metabolic disturbance (particularly lipid and glucose metabolism) and immune suppression, and finally, chronic liver fibrosis in a high-fat diet (HFD)-induced disease model. Mechanistically, cells with HCV JFH-1 replicons upregulate ISX and, consequently, the expressions of metabolic, fibrosis progenitor, and immune modulators via core protein-induced nuclear factor-κB signaling. Conversely, cells with specific ISX shRNAi inhibit HCV core protein-induced metabolic disturbance and immune suppression. Clinically, the HCV core level is significantly correlated with ISX, IDOs, PD-L1, and B7-2 levels in HCC patients with HCV infection. Therefore, it highlights the significance of HCV core protein-ISX axis as an important mechanism in the development of HCV-induced chronic liver disease and can be a specific therapeutic target clinically.

HIGH-DENSITY LIPOPROTEIN CHOLESTEROL AND SYSTEMIC ARTERIAL HYPERTENSION ARE ASSOCIATED WITH HEPATIC NECROINFLAMMATORY ACTIVITY IN PATIENTS WITH CHRONIC HEPATITIS C

•HDL cholesterol levels <60 mg/dL were independently associated with necroinflammatory activity in chronic hepatitis C (CHC). •CHC patients with hypertension are at an increased risk of developing necroinflammatory activity. •In patients with CHC, liver fibrosis was independently associated with old age, steatosis, and HDL-C <60 mg/dL. •Triglycerides levels ≥150 mg/dL were associated with lobular inflammatory activity in patients with CHC. Background - Approximately 71 million people are chronically infected with hepatitis C virus (HCV) worldwide. A significant number of these individuals will develop liver cirrhosis and/or hepatocellular carcinoma. Beyond the liver, there is a sizeable body of scientific evidence linking cardiovascular disease and chronic hepatitis C (CHC); however, the biological mechanisms behind the concurrence of these conditions have not been completely clarified yet. Objective - To evaluate associations between hepatic histology, clinical comorbidities and lipid profile in patients with CHC. To investigate associations between liver histology and demographic, nutritional, biochemical and virological parameters. Methods - Eight-five patients with CHC prospectively underwent hepatic biopsy. Liver fragments were obtained from each patient by percutaneous route using a Menghini needle. Fibrosis was evaluated according to the METAVIR scoring system, as follows: F0, no fibrosis; F1, fibrous portal expansion; F2, fibrous portal widening with few septa; F3, bridging fibrosis with architectural distortion; and F4, liver cirrhosis. The activity was classified based on the degree of lymphocyte infiltration and hepatocyte necrosis, from A0 to A3. The diagnosis of liver disease was based on clinical, biochemical, histological, and radiological methods. The data were analyzed by logistic regression models. Results - This cross-sectional study included 85 outpatients followed at the tertiary care ambulatory centre with a mean age of 57.2±10.7 years and 45 (52.9%) were females. There were 10 patients with cirrhosis. Patients with a METAVIR F3-F4 were significantly older (P=0.02) and had higher levels of ALT (P=0.0006), AST (P<0.0001), γ-GT (P=0.03) and bilirubin (P=0.001) and higher prothrombin time than patients with F0-F2 score. Albumin levels (P=0.01) were significantly lower in METAVIR F3-F4. Age (OR=1.09; 95%CI=1.02-1.16; P=0.02), steatosis (OR=4.03; 95%CI=1.05-15.45; P=0.04) and high-density lipoprotein cholesterol (HDL-C) <60 mg/dL (OR=7.67; 95%CI=1.71-34.49; P=0.008) were independently associated with fibrosis. Hypertension (OR=6.36; 95%CI=1.31-30.85; P=0.02) and HDL-C <60 mg/dL (OR=9.85; 95%CI=2.35-41.39; P=0.002) were independently associated with necroinflammatory activity. Hypertension (OR=6.94; 95%CI=1.92-25.05; P=0.003) and HDL-C <60 mg/dL (OR=3.94; 95%CI=1.27-12.3; P=0.02) were associated with interface inflammatory activity. Triglycerides (TG ≥150 mg/dL) remained associated with lobular inflammatory activity. Conclusion - cholesterol levels <60 mg/dL were independently associated with necroinflammatory activity in chronic hepatitis C. Patients with hypertension are at an increased risk of developing necroinflammatory activity.

Hepatitis C Virus-Lipid Interplay: Pathogenesis and Clinical Impact

Hepatitis C virus (HCV) infection represents the major cause of chronic liver disease, leading to a wide range of hepatic diseases, including cirrhosis and hepatocellular carcinoma. It is the leading indication for liver transplantation worldwide. In addition, there is a growing body of evidence concerning the role of HCV in extrahepatic manifestations, including immune-related disorders and metabolic abnormalities, such as insulin resistance and steatosis. HCV depends on its host cells to propagate successfully, and every aspect of the HCV life cycle is closely related to human lipid metabolism. The virus circulates as a lipid-rich particle, entering the hepatocyte via lipoprotein cell receptors. It has also been shown to upregulate lipid biosynthesis and impair lipid degradation, resulting in significant intracellular lipid accumulation (steatosis) and circulating hypocholesterolemia. Patients with chronic HCV are at increased risk for hepatic steatosis, dyslipidemia, and cardiovascular disease, including accelerated atherosclerosis. This review aims to describe different aspects of the HCV viral life cycle as it impacts host lipoproteins and lipid metabolism. It then discusses the mechanisms of HCV-related hepatic steatosis, hypocholesterolemia, and accelerated atherosclerosis.

Endoplasmic Reticulum Stress in Hepatitis B Virus and Hepatitis C Virus Infection

Endoplasmic reticulum (ER) stress, a type of cellular stress, always occurs when unfolded or misfolded proteins accumulating in the ER exceed the protein folding capacity. Because of the demand for rapid viral protein synthesis after viral infection, viral infections become a risk factor for ER stress. The hepatocyte is a cell with large and well-developed ER, and hepatitis virus infection is widespread in the population, indicating the interaction between hepatitis viruses and ER stress may have significance for managing liver diseases. In this paper, we review the process that is initiated by the hepatocyte through ER stress against HBV and HCV infection and explain how this information can be helpful in the treatment of HBV/HCV-related diseases.

ABCA1 Polymorphism R1587K in Chronic Hepatitis C Is Gender-Specific and Modulates Liver Disease Severity through Its Influence on Cholesterol Metabolism and Liver Function: A Preliminary Study

Chronic hepatitis C (CHC) progression is highly variable and can be influenced by lipid metabolism. The ATP-binding cassette transporter A1 (ABCA1) is involved in lipid metabolism and mediates cholesterol efflux from liver cells. ABCA1 gene polymorphism rs2230808 (R1587K) modulates lipid levels as it is located in an ABCA1 protein domain, which is essential for cholesterol efflux. We aimed to analyze the role of ABCA1 polymorphism R1587K (rs2230808) in modulating the biochemical parameters of lipid metabolism and liver function and its association with liver disease severity, according to gender. A total of 161 CHC patients were clinically, histologically, and biochemically evaluated. Genotyping was performed by melting-curve analysis and statistical analysis by SPSS 24.0. There were significant differences between ABCA1_rs2230808 genotypes and total cholesterol, γGT (γ-glutamyl-transpeptidase), and HCV-RNA. Gender differences: in females, ABCA1_rs2230808 (GG or GA) was associated with higher HCV-RNA serum levels; in males, ABCA1_rs2230808 (GG or GA) was associated with higher γGT, lower total cholesterol, increased risk for γGT ≥ 38 UI/L, and total cholesterol < 4.92 mmol/L. Only in the case of males were higher γGT and lower total cholesterol associated with severe fibrosis and steatosis. Total cholesterol < 4.92 mmol/L also associates with severe necroinflammation. We conclude that ABCA1_rs2230808 is gender-specific. ABCA1_rs2230808 Allele G was associated with different clinical and biochemical parameters, which are related to more severe liver disease.

Sex-specific changes in triglyceride profiles in liver cirrhosis and hepatitis C virus infection

Background

Hepatitis C virus (HCV) infection is associated with serum lipid abnormalities, which partly normalize following direct-acting antiviral (DAA) therapy. Here, associations of serum triglycerides (TGs) with viral genotype and markers of liver disease severity were evaluated in patients with chronic HCV. 

Methods

The study included the serum of 177 patients with chronic HCV. TGs were quantified by flow injection analysis Fourier transform mass spectrometry. Laboratory values and noninvasive scores for liver fibrosis assessment were determined. The nonparametric Kruskal‒Wallis test, one-way ANOVA, multiple linear regression and Student’s t test were used as appropriate. P values were adjusted for multiple comparisons.

Results

HCV-infected women had lower serum TGs than men, and thus, a sex-specific analysis was performed. None of the 46 TG species analyzed differed in the serum of female patients with and without liver cirrhosis. In contrast, in the serum of male patients with liver cirrhosis, TGs with 53, 56 and 58 carbon atoms and three to eight double bonds were diminished. These polyunsaturated TGs were also low in males with a high fibrosis-4 score. TGs with 7 or 8 double bonds negatively correlated with the model of end-stage liver disease score in males. In addition, TGs with 49, 51 and 53 carbon atoms were reduced in male patients infected with genotype 3a in comparison to genotype 1a. TGs with 56 carbon atoms were lower in genotype 3a-infected males than in genotype 1b-infected males. TGs did not differ in females by genotype. Genotype 3-related changes disappeared at the end of therapy with DAAs. Overall, the levels of serum TGs did not change during DAA therapy in either sex. Consequently, the serum TGs of males with liver cirrhosis were lower than those of males without cirrhosis at the end of therapy. Such a difference was not apparent in females.

Conclusions

The decline in TGs observed only in male patients with liver cirrhosis and male patients infected with genotype 3 illustrates sex-specific changes in lipid metabolism in chronic HCV.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01715-w.

The potential roles of interleukin-25 in infectious diseases

Interleukin-25 (IL-25), also known as IL-17E, is a recently identified cytokine of the IL-17 family. Numerous studies illustrated that the expression of IL-25 is regulated by multiple pathogens, including parasitic, viral, and bacterial infections. IL-25 has a dual function in infectious diseases. On the one hand, IL-25 activates type 2 immunity via the relevant cytokines, including IL-4, IL-5, and IL-13, which are associated with the development of pathogenic infection-related allergic diseases. On the other hand, IL-25 involves in the recruitment of group 2 innate lymphoid cells (ILC2) to enhanced T helper 2 (Th2) cell differentiation, which are important to the clearance of pathogens. However, the precise roles of IL-25 in infectious diseases remain largely unknown. Thus, the current review will shed light on the pivotal roles of IL-25 in infectious diseases.

microRNA-27b regulates hepatic lipase enzyme LIPC and reduces triglyceride degradation during hepatitis C virus infection

miRNAs are short, noncoding RNAs that negatively and specifically regulate protein expression, the cumulative effects of which can result in broad changes to cell systems and architecture. The miRNA miR-27b is known to regulate lipid regulatory pathways in the human liver and is also induced by the hepatitis C virus (HCV). However, the functional targets of miR-27b are not well established. Herein, an activity-based protein profiling method using a serine hydrolase probe, coupled with stable isotope labeling and mass spectrometry identified direct and indirect targets of miR-27b. The hepatic lipase C (LIPC) stood out as both highly dependent on miR-27b and as a major modulator of lipid pathway misregulation. Modulation of miR-27b using both exogenous miRNA mimics and inhibitors demonstrated that transcription factors Jun, PPARα, and HNF4α, all of which also influence LIPC levels and activity, are regulated by miR-27b. LIPC was furthermore shown to affect the progress of the life cycle of HCV and to decrease levels of intracellular triglycerides, upon which HCV is known to depend. In summary, this work has demonstrated that miR-27b mediates HCV infection by downregulating LIPC, thereby reducing triglyceride degradation, which in turn increases cellular lipid levels.

Effect of achieving sustained virological response with direct-acting antiviral agents on glycemic control in diabetic patients with chronic hepatitis C infection

Background

Hepatitis C virus (HCV) is a significant cause of chronic hepatitis, cirrhosis, and hepatocellular carcinoma worldwide. Liver disease is not the only problem caused by chronic HCV infection; many extrahepatic complications, such as insulin resistance, can be associated with HCV infection. The aim of this study was to assess the effect of achieving a sustained virological response after treatment with directly acting antiviral drugs on insulin resistance in patients with chronic HCV infection.

Results

This prospective study was conducted on 46 HCV patients with type 2 diabetes mellitus who received directly acting antiviral drugs for HCV infections. Fasting insulin, fasting blood glucose, and lipid profiles were assessed in all patients at three time points: before treatment, at the end of treatment, and 12 weeks after the end of treatment. Despite using three different directly acting antiviral drug regimens, all patients achieved a sustained viral response, regardless of the regimen used. the Homeostatic Model Assessment for Insulin Resistance decreased significantly at the end of treatment; however, when recalculated at week 12 after end of treatment, the reduction of the Homeostatic Model Assessment for Insulin Resistance was not significant compared to the baseline levels. Total cholesterol and low-density lipoproteins increased at the end of treatment and continued to increase for 12 weeks after the end of treatment.

Conclusions

Improvements in insulin resistance and glycemic control were noted in HCV patients at the end of treatment with directly acting antiviral drugs; this effect was also apparent after 12 weeks. An increase in the levels of total cholesterol and low-density lipoprotein can be expected after treatment with directly acting antiviral drugs.

Hepatitis C virus: A critical approach to who really needs treatment

Introduction of effective drugs in the treatment of hepatitis C virus (HCV) infection has prompted the World Health Organization to declare a global eradication target by 2030. Propositions have been made to screen the general population and treat all HCV carriers irrespective of the disease status. A year ago the new severe acute respiratory syndrome coronavirus 2 virus appeared causing a worldwide pandemic of coronavirus disease 2019 disease. Huge financial resources were redirected, and the pandemic became the first priority in every country. In this review, we examined the feasibility of the World Health Organization elimination program and the actual natural course of HCV infection. We also identified and analyzed certain comorbidity factors that may aggravate the progress of HCV and some marginalized subpopulations with characteristics favoring HCV dissemination. Alcohol consumption, HIV coinfection and the presence of components of metabolic syndrome including obesity, hyperuricemia and overt diabetes were comorbidities mostly responsible for increased liver-related morbidity and mortality of HCV. We also examined the significance of special subpopulations like people who inject drugs and males having sex with males. Finally, we proposed a different micro-elimination screening and treatment program that can be implemented in all countries irrespective of income. We suggest that screening and treatment of HCV carriers should be limited only in these particular groups.

Domain 2 of Hepatitis C Virus Protein NS5A Activates Glucokinase and Induces Lipogenesis in Hepatocytes

Hepatitis C virus (HCV) relies on cellular lipid metabolism for its replication, and actively modulates lipogenesis and lipid trafficking in infected hepatocytes. This translates into an intracellular accumulation of triglycerides leading to liver steatosis, cirrhosis and hepatocellular carcinoma, which are hallmarks of HCV pathogenesis. While the interaction of HCV with hepatocyte metabolic pathways is patent, how viral proteins are able to redirect central carbon metabolism towards lipogenesis is unclear. Here, we report that the HCV protein NS5A activates the glucokinase (GCK) isoenzyme of hexokinases through its D2 domain (NS5A-D2). GCK is the first rate-limiting enzyme of glycolysis in normal hepatocytes whose expression is replaced by the hexokinase 2 (HK2) isoenzyme in hepatocellular carcinoma cell lines. We took advantage of a unique cellular model specifically engineered to re-express GCK instead of HK2 in the Huh7 cell line to evaluate the consequences of NS5A-D2 expression on central carbon and lipid metabolism. NS5A-D2 increased glucose consumption but decreased glycogen storage. This was accompanied by an altered mitochondrial respiration, an accumulation of intracellular triglycerides and an increased production of very-low density lipoproteins. Altogether, our results show that NS5A-D2 can reprogram central carbon metabolism towards a more energetic and glycolytic phenotype compatible with HCV needs for replication.

Adherence to a Fish-Rich Dietary Pattern Is Associated with Chronic Hepatitis C Patients Showing Low Viral Load: Implications for Nutritional Management

Hepatitis C virus (HCV) infection is influenced by genetic (e.g., APOE polymorphisms) and environmental factors between the virus and the host. HCV modulates the host’s lipid metabolism but dietary components influence lipids and in vitro HCV RNA replication. Few data exist on the role of dietary features or patterns (DPs) in HCV infection. Herein, we aimed to evaluate the nutritional profiles of chronic HCV (CHC) and spontaneous clearance (SC) Mexican patients in the context of APOE alleles and their correlation with HCV-related variables. The fibrosis-related APOEε3 allele prevailed in CHC and SC patients, who had four DPs (“meat and soft drinks”, DP1; “processed animal and fried foods”, DP2; “Mexican-healthy”, DP3; and “fish-rich”, DP4). In CHC subjects, polyunsaturated fatty acid intake (PUFA ≥ 4.9%) was negatively associated, and fiber intake (≥21.5 g/day) was positively associated with a high viral load (p < 0.036). High adherence to fish-rich DP4 was associated with a higher frequency of CHC individuals consuming PUFA ≥ 4.9% (p = 0.004) and low viral load (p = 0.036), but a lower frequency of CHC individuals consuming fiber ≥21.5 g/day (p = 0.038). In SC and CHC individuals, modifying unhealthy DPs and targeting HCV-interacting nutrients, respectively, could be part of a nutritional management strategy to prevent further liver damage.

Hepatitis C virus induces oxidation and degradation of apolipoprotein B to enhance lipid accumulation and promote viral production

Hepatitis C virus (HCV) infection induces the degradation and decreases the secretion of apolipoprotein B (ApoB). Impaired production and secretion of ApoB-containing lipoprotein is associated with an increase in hepatic steatosis. Therefore, HCV infection-induced degradation of ApoB may contribute to hepatic steatosis and decreased lipoprotein secretion, but the mechanism of HCV infection-induced ApoB degradation has not been completely elucidated. In this study, we found that the ApoB level in HCV-infected cells was regulated by proteasome-associated degradation but not autophagic degradation. ApoB was degraded by the 20S proteasome in a ubiquitin-independent manner. HCV induced the oxidation of ApoB via oxidative stress, and oxidized ApoB was recognized by the PSMA5 and PSMA6 subunits of the 20S proteasome for degradation. Further study showed that ApoB was degraded at endoplasmic reticulum (ER)-associated lipid droplets (LDs) and that the retrotranslocation and degradation of ApoB required Derlin-1 but not gp78 or p97. Moreover, we found that knockdown of ApoB before infection increased the cellular lipid content and enhanced HCV assembly. Overexpression of ApoB-50 inhibited lipid accumulation and repressed viral assembly in HCV-infected cells. Our study reveals a novel mechanism of ApoB degradation and lipid accumulation during HCV infection and might suggest new therapeutic strategies for hepatic steatosis.

Hepatitis C virus (HCV) infection induces the degradation of apolipoprotein B (ApoB), which is the primary apolipoprotein in low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL). Impaired production and secretion of ApoB-containing lipoprotein is associated with an increase in hepatic steatosis. Thus, ApoB degradation might contribute to HCV infection-induced fatty liver. Here, we found that ApoB was not degraded through endoplasmic reticulum-associated degradation (ERAD) or autophagy, as reported previously. Instead, HCV infection induced ApoB oxidation through oxidative stress, and oxidatively damaged ApoB could be recognized and directly degraded by the 20S proteasome. We also found that ApoB was retrotranslocated from the endoplasmic reticulum (ER) to lipid droplets (LDs) for degradation. Through overexpression of ApoB-50, which can mediate the assembly and secretion of LDL and VLDL, we confirmed that ApoB degradation contributed to hepatocellular lipid accumulation induced by HCV infection. Additionally, expression of ApoB-50 impaired HCV production due to the observed decrease in lipid accumulation. In this study, we identified new mechanisms of ApoB degradation and HCV-induced lipid accumulation, and our findings might facilitate the development of novel therapeutic strategies for HCV infection-induced fatty liver.

Quantitative and qualitative lipid improvement with chronic hepatitis C virus eradication using direct-acting antivirals

AIM

Direct-acting antivirals have revolutionized hepatitis C virus (HCV) therapy by providing a high sustained virological response (SVR) rate and subsequent favorable lipid increases. Proprotein convertase subtilisin-kexin like-9 (PCSK9) plays an important role in regulating quantitative lipid levels. This study examined the interactions between quantitative PCSK9 and lipid changes, as well as qualitative lipid changes in terms of lectin-like oxidized low-density lipoprotein (LDL) receptor-1 ligand containing apolipoprotein B (LAB) and high-density lipoprotein (HDL) cholesterol uptake capacity (HDL-CUC).

METHODS

Patients with chronic HCV infection (N = 231) who achieved an SVR by direct-acting antivirals without lipid-lowering therapy were included for comparisons of PCSK9, LAB, HDL-CUC, and other clinical indices between pretreatment and SVR12 time points.

RESULTS

LDL (LDL) cholesterol and HDL cholesterol levels were quantitatively increased at SVR12, along with higher PCSK9 (all p < 0.0001). PCSK9 was significantly correlated with LDL cholesterol (r = 0.244, p = 0.0003) and apolipoprotein B (r = 0.222, p = 0.0009) at SVR12. Regarding qualitative LDL changes, LAB was significantly decreased and LAB/LDL cholesterol and LAB/apolipoprotein B proportions were improved at SVR12 (all p < 0.0001). In terms of qualitative HDL changes, HDL-CUC was significantly ameliorated, along with HDL-CUC/HDL cholesterol, HDL-CUC/ apolipoprotein A1, and HDL-CUC/ apolipoprotein A2 at SVR12 (all p < 0.0001).

CONCLUSIONS

HCV eradication by direct-acting antivirals may produce quantitative lipid profile changes, along with PCSK9 production recovery in addition to qualitative lipid improvement, which possibly confers the additional secondary benefits of atherosclerosis improvement and cardiovascular disease event reduction.

PCSK9 and cancer: Rethinking the link

BACKGROUND

Cancer is emerging as a major problem globally, as it accounts for the second cause of death despite medical advances. According to epidemiological and basic studies, cholesterol is involved in cancer progression and there are abnormalities in cholesterol metabolism of cancer cells including prostate, breast, and colorectal carcinomas. However, the importance of cholesterol in carcinogenesis and thereby the role of cholesterol homeostasis as a therapeutic target is still a debated area in cancer therapy. Proprotein convertase subtilisin/kexin type-9 (PCSK9), a serine protease, modulates cholesterol metabolism by attachment to the LDL receptor (LDLR) and reducing its recycling by targeting the receptor for lysosomal destruction. Published research has shown that PCSK9 is also involved in degradation of other LDLR family members namely very-low-density-lipoprotein receptor (VLDLR), lipoprotein receptor-related protein 1 (LRP-1), and apolipoprotein E receptor 2 (ApoER2). As a result, this protein represents an interesting therapeutic target for the treatment of hypercholesterolemia. Interestingly, clinical trials on PCSK9-specific monoclonal antibodies have reported promising results with high efficacy in lowering LDL-C and in turn reducing cardiovascular complications. It is important to note that PCSK9 mediates several other pathways apart from its role in lipid homeostasis, including antiviral activity, hepatic regeneration, neuronal apoptosis, and modulation of various signaling pathways. Furthermore, recent literature has illustrated that PCSK9 is closely associated with incidence and progression of several cancers. In a number of studies, PCSK9 siRNA was shown to effectively suppress the proliferation and invasion of the several studied tumor cells. Hence, a novel application of PCSK9 inhibitors/silencers in cancer/metastasis could be considered. However, due to poor data on effectiveness and safety of PCSK9 inhibitors in cancer, the impact of PCSK9 inhibition in these pathological conditions is still unknown.

SEARCH METHODS

A vast literature search was conducted to find intended studies from 1956 up to 2020, and inclusion criteria were original peer-reviewed publications.

PURPOSE OF REVIEW

To date, PCSK9 has been scantly investigated in cancer. The question that needs to be discussed is "How does PCSK9 act in cancer pathophysiology and what are the risks or benefits associated to its inhibition?". We reviewed the available publications highlighting the contribution of this proprotein convertase in pathways related to cancer, with focus on the potential implications of its long-term pharmacological inhibition in cancer therapy.

Molecular Events Occurring in Lipophagy and Its Regulation in Flaviviridae Infection

Diseases caused by Flaviviridae have a wide global and economic impact due to high morbidity and mortality. Flaviviridae infection usually leads to severe, acute or chronic diseases, such as liver injury and liver cancer resulting from hepatitis C virus (HCV) infection, dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS) caused by dengue virus (DENV). Given the highly complex pathogenesis of Flaviviridae infections, they are still not fully understood at present. Accumulating evidence suggests that host autophagy is disrupted to regulate the life cycle of Flaviviridae. Organelle-specific autophagy is able to selectively target different organelles for quality control, which is essential for regulating cellular homeostasis. As an important sub process of autophagy, lipophagy regulates lipid metabolism by targeting lipid droplets (LDs) and is also closely related to the infection of a variety of pathogenic microorganisms. In this review, we briefly understand the LDs interaction relationship with Flaviviridae infection, outline the molecular events of how lipophagy occurs and the related research progress on the regulatory mechanisms of lipophagy in Flaviviridae infection. Exploring the crosstalk between viral infection and lipophagy induced molecular events may provide new avenues for antiviral therapy.

Profiling of MicroRNA Targets Using Activity-Based Protein Profiling: Linking Enzyme Activity to MicroRNA-185 Function

MicroRNAs (miRNAs) act as cellular signal transducers through repression of protein translation. Elucidating targets using bioinformatics and traditional quantitation methods is often insufficient to uncover global miRNA function. Herein, alteration of protein function caused by miRNA-185 (miR-185), an immunometabolic miRNA, was determined using activity-based protein profiling, transcriptomics, and lipidomics. Fluorophosphonate-based activity-based protein profiling of miR-185-induced changes to human liver cells revealed that exclusively metabolic serine hydrolase enzymes were regulated in activity, some with roles in lipid and endocannabinoid metabolism. Lipidomic analysis linked enzymatic changes to levels of cellular lipid species, such as components of very-low-density lipoprotein particles. Additionally, inhibition of one miR-185 target, monoglyceride lipase, led to decreased hepatitis C virus levels in an infectious model. Overall, the approaches used here were able to identify key functional changes in serine hydrolases caused by miR-185 that are targetable pharmacologically, such that a small molecule inhibitor can recapitulate the miRNA phenotype.

High-density lipoprotein cholesterol is a predictor of survival in cirrhotic patients with acute gastrointestinal bleeding: a retrospective study

Background

Lipid profiles are declined in patients with viral liver cirrhosis and correlated with severity of liver disease. Hepatitis B virus (HBV) is the leading cause of liver cirrhosis in China. Our primary aim was to investigate whether serum lipids and lipoproteins associate with survival in patients with HBV-related cirrhosis and acute gastrointestinal bleeding, and develop a 6-week mortality risk score that incorporates it.

Methods

From January 2008 to December 2015, consecutive cirrhotic patients with acute gastrointestinal bleeding admitted to our hospital were evaluated and randomly divided into the derivation (n = 629) and validation (n = 314) cohorts. A logistic regression model was established to confirm the association between lipoprotein cholesterol and mortality. Accuracy to predict mortality were assessed by area under the receiver operating characteristic curves (AUROCs) and compared using the Hanley and McNeil test.

Results

Among study subjects, the 6-week mortality rate was 10.6%. High-density lipoprotein cholesterol (HDL-C) level was found to correlate most strongly with prognostic scores. On ROC analysis, HDL-C showed excellent diagnostic accuracy for 6-week mortality. Logistic regression analysis provided a simple algorithm based on the combined use of 4 variables (total bilirubin (TBIL), HDL-C, International normalized ratio, and hemoglobin), allowing accurate discrimination of 3 distinct prognostic subgroups with 1.7% (low risk), 12.3% (intermediate risk), and 56.9% (high risk) mortality. Its accuracy was significantly better than that of Child–Pugh, model of end-stage liver disease, albumin-bilirubin score, D’Amico model, Augustin model, AIMS65 score and Glasgow-Blatchford score. Baseline HDL-C values ≤ 0.54 mmol/L were associated with markedly lower 6-week survival. Comparable results were found in the validation set.

Conclusion

HDL-C is a potential indicator for the prognosis of patients with cirrhosis and acute gastrointestinal bleeding. The new algorithm based on HDL-C allowed an accurate predictive assessment of 6-week mortality after bleeding attack.

Correlation of Fasting Lipid Profile in Patients With Chronic Liver Disease: A Descriptive Cross-Sectional Study in Tertiary Care Hospital

Introduction: Chronic liver disease (CLD) is a term used to describe a wide spectrum of disorders, including idiopathic, infectious, genetic, drug-induced, toxin-induced, and autoimmune disorders. The common consequence of chronic damage to the liver is cirrhosis. Cirrhotic patients are further classified by their severity based on the Child-Pugh scoring system. Currently, Child-Pugh scoring consists of ascites, hepatic encephalopathy (HE), prothrombin time, serum albumin level, and total bilirubin level. Lipid panel in CLD is a great marker in determining the severity of CLD.

Method and methodology: It was a descriptive cross-sectional study conducted at a tertiary care hospital. A sample size of 122 was calculated by using a RaoSoft Digital Sample Size Calculator (RaoSoft, Inc., Seattle, WA) in which we used 5% as a margin of error, 95% as confidence interval (CI), 178 as population size, and response distribution as 50%. Non-complicated CLD patients having age in between 15 and 80 years with no cirrhotic complications including HE, spontaneous bacterial peritonitis, hepato-pumonary, or hepato-renal syndrome were included in our study; the rest of the CLD patients were excluded from our study.

Results: The mean age of the study population was 47.09 ± 12.30 years with more than half of the patients lying among the age group 25-50 years. The study population included 76% of males (n=93) and 24% of females (n=29), with a mean age of females higher than the males. Diabetes mellitus (58.19%) was the most frequent comorbidity associated with CLD in subjects included in our study. Parameters of lipid panel were decreased exponentially as the severity of CLD increases from Child score A to C. Total cholesterol, low-density lipoprotein (LDL), very-low-density lipoprotein (VLDL), high-density lipoprotein (HDL), and triglyceride (TG) level decreased as the severity increases in our study. The mean model for end-stage liver disease (MELD) score increased as per hypothesized as the severity increases from Child score A to Child score C, respectively.

Conclusion: Our study concluded that as the severity of CLD increases from Child class A to Child class C, the lipid panel profile decreases exponentially which proved the idea that had been hypothesized at the beginning of our study.

Metabolic and renal changes in patients with chronic hepatitis C infection after hepatitis C virus clearance by direct-acting antivirals

Background and Aim

The impact of hepatitis C virus (HCV) clearance by direct-acting antiviral agents (DAAs) on HCV-related extrahepatic manifestations is not well known. We evaluated the effect of viral clearance on metabolic and renal parameters.

Methods

In this prospective study, HCV patients who achieved a sustained virologic response (SVR) by DAAs were evaluated before, at the end, and 24 weeks after treatment for glycemic (serum glucose and insulin, HOMA-IR, HOMA-β, and HOMA-S) and lipid (serum cholesterol, triglycerides, low-density lipoprotein [LDL], high-density lipoprotein) metabolism and renal function (serum creatinine, estimated glomerular filtration rate [eGFR]).

Results

A total of 343 consecutive HCV patients were evaluated. At 24 weeks of post-follow-up, an increase in body mass index (BMI) was observed (P < 0.05). Regardless of hepatic fibrosis levels and BMI, a reduction in serum glucose (P = 0.001), HOMA-IR (P < 0.001) and HOMA-β (P < 0.001) and an increase in HOMA-S (P < 0.001) values were observed at 24 weeks after HCV clearance as compared to pretreatment values; 32.4% of patients with impaired fasting glucose normalized serum glucose values and 44.6% of diabetics showed an improvement in glycemic control. In contrast, serum cholesterol (P < 0.001) and LDL cholesterol (P < 0.001) values were increased. Renal function was improved with about 10% reduction of serum creatinine values (P < 0.02) and an increase of eGFR (P < 0.001). A baseline eGFR of ≤60 mL/min/1.73 m² was a negative predictor of renal function improvement. HCV clearance was an independent factor improving glucose metabolism and renal function.

Conclusions

Our study shows an occurrence of changes in metabolic and renal parameters in HCV patients with SVR, anticipating possible future clinical scenarios that the clinician must know for proper management.

IL28B gene polymorphism is correlated with changes in low-density lipoprotein cholesterol levels after clearance of hepatitis C virus using direct-acting antiviral treatment

BACKGROUND

Direct-acting antivirals (DAAs) rapidly clear hepatitis C virus (HCV), but the lipid dynamics after DAA treatment remain unknown. Low-density lipoprotein (LDL) cholesterolemia is the predicting factor for the onset and death of atherosclerotic cardiovascular diseases. Thus, in this study, we examined the frequency and risk of hyper-LDL cholesterolemia in HCV patients who achieved sustained virologic response (SVR) with DAA treatment.

METHODS

A total of 121 patients with HCV genotype 1b, who achieved SVR with DAA treatment, were examined for serum levels of total cholesterol, LDL-cholesterol (LDL-C), high-density lipoprotein, and triglycerides from the start of treatment until 2 years after SVR (SVR-2y). ΔLDL-C was defined as the change in LDL-C levels from treatment initiation to SVR-2y. Hyper-LDL cholesterolemia was defined as ≥ 140 mg/dL LDL-C at SVR-2y. Stepwise multiple regression analysis was performed to determine whether ΔLDL-C and hyper-LDL cholesterolemia are associated with other factors, including viral kinetics.

RESULTS

A total of 63, 3, and 55 patients were administered daclatasvir + asunaprevir, ombitasvir + paritaprevir + ritonavir, and ledipasvir + sofosbuvir, respectively. ΔLDL-C in patients with the IL28B (rs8099917) TG/GG genotype was significantly higher than in those with IL28B TT (27.3 ± 27.0 and 9.6 ± 27.3 mg/dL; P < 0.001). In addition, IL28B TG/GG was an independent risk factor for hyper-LDL cholesterolemia (odds ratio: 8.47; P < 0.001).

CONCLUSIONS

An IL28B polymorphism is associated with ΔLDL-C and hyper-LDL cholesterolemia after achieving SVR. Thus, lipid markers should be carefully monitored in patients who achieve SVR with DAA.

A genome-wide association study on low susceptibility to hepatitis C virus infection (GEHEP012 study)

BACKGROUND

A low proportion of individuals repeatedly exposed to the hepatitis C virus (HCV) remain uninfected. This condition could have a genetic basis but it is not known whether or not it is mainly driven by a high-penetrance common allele.

OBJECTIVE

To explore whether low susceptibility to HCV infection is mainly driven by a high-penetrance common allele.

METHODS

In this genome-wide association study (GWAS), a total of 804 HCV-seropositive individuals and 27 high-risk HCV-seronegative (HRSN) subjects were included. Plink and Magma software were used to carry out single nucleotide polymorphism (SNP)-based and gene-based association analyses respectively.

RESULTS

No SNP nor any gene was associated with low susceptibility to HCV infection after multiple testing correction. However, SNPs previously associated with this trait and allocated within the LDLR gene, rs5925 and rs688, were also associated with this condition in our study under a dominant model (24 out of 27 [88.9%] rs5925-C carriers in the HRSN group vs 560 of 804 [69.6%] rs5925-C carriers in the HCV-seropositive group, P = 0.031, odds ratio [OR] = 3.48; 95% confidence interval [CI] = 1.04-11.58; and 24 out of 27 [88.9%] rs688-T carriers in the HRSN group vs 556 of 804 [69.1%] rs688-T carriers in the HCV-seropositive group, P = 0.028, OR = 3.57, 95% CI = 1.65-11.96).

CONCLUSIONS

Low susceptibility to HCV infection does not seem to be mainly driven by a high-penetrant common allele. By contrast, it seems a multifactorial trait where genes such as LDLR could be involved.

Transforming Growth Factor β Acts as a Regulatory Molecule for Lipogenic Pathways among Hepatitis C Virus Genotype-Specific Infections

Hepatitis C virus (HCV) infection promotes metabolic disorders, and the severity of lipogenic disease depends upon the infecting virus genotype. Here, we have examined HCV genotype 1-, 2-, or 3-specific regulation of lipid metabolism, involving transforming growth factor β (TGF-β)-regulated phospho-Akt (p-Akt) and peroxisome proliferator-activated receptor alpha (PPARα) axes. Since HCV core protein is one of the key players in metabolic regulation, we also examined its contribution in lipid metabolic pathways. The expression of regulatory molecules, TGF-β1/2, phospho-Akt (Ser473), PPARα, sterol regulatory element-binding protein 1 (SREBP-1), fatty acid synthase (FASN), hormone-sensitive lipase (HSL), and acyl dehydrogenases was analyzed in virus-infected hepatocytes. Interestingly, HCV genotype 3a exhibited much higher activation of TGF-β and p-Akt, with a concurrent decrease in PPARα expression and fatty acid oxidation. A significant and similar decrease in HSL, unlike in HCV genotype 1a, was observed with both genotypes 2a and 3a. Similar observations were made from ectopic expression of the core genomic region from each genotype. The key role of TGF-β was further verified using specific small interfering RNA (siRNA). Together, our results highlight a significant difference in TGF-β-induced activity for the HCV genotype 2a- or 3a-induced lipogenic pathway, exhibiting higher triglyceride synthesis and a decreased lipolytic mechanism. These results may help in therapeutic modalities for early treatment of HCV genotype-associated lipid metabolic disorders.IMPORTANCE Hepatic steatosis is a frequent complication associated with chronic hepatitis C virus (HCV) infection and is a key prognostic indicator for progression to fibrosis and cirrhosis. Several mechanisms are proposed for the development of steatosis, especially with HCV genotype 3a. Our observations suggest that transforming growth factor β (TGF-β) and peroxisome proliferator-activated receptor alpha (PPARα)-associated mechanistic pathways in hepatocytes infected with HCV genotype 2a and 3a differ from those in cells infected with genotype 1a. The results suggest that a targeted therapeutic approach for enhanced PPARα and lipolysis may reduce HCV genotype-associated lipid metabolic disorder in liver disease.

Factors That Influence the Virological Response in Patients with Chronic Hepatitis C Treated with Pegylated Interferon and Ribavirin

INTRODUCTION

The success of the antiviral treatment in patients with chronic hepatitis C depends on the factors related to the virus and the host. The aim of the study is the analysis of the antiviral therapy which is a combination of pegylated interferon and ribavirin, considering various factors that will identify the predictors of the sustained virological response.

MATERIAL AND METHODS

This retrospective study included 226 patients, divided in two groups. Patients with sustained virological response and patients without sustained virological response were compared in terms of the following factors: genotype, viral load, gender, age, inflammatory and fibrotic changes in the liver, metabolic abnormalities, obesity and fatty liver.

RESULTS

The rate of the sustained virological response is 83.6%, more frequently in patients with genotype 3, with evidenced statistical significance (90.54%). The factors that significantly contribute to sustained virological response are related to the age (p = 0.0001), genotype (p = 0.002), mode of transmission (p = 0.005), inflammatory changes in the liver (p = 0.028), body mass index (p = 0.022) and insulin resistance (p = 0.039). The high rate of sustained virological response is related to the younger age of the patients which indirectly means short Hepatitis C Virus infection duration, absence of advanced liver disease and lack of significant co-morbid conditions. Single confirmed independent predictors of sustained virological response are the age (OR 0.928, p = 0.0001) and genotype (OR 3.134, p = 0.005).

CONCLUSIONS

Factors that are related to the virological response are the age, genotype, mode of transmission, inflammatory changes in the liver, body mass index and insulin resistance, but still, independent predictors of sustained virologic response are the age and the genotype.

Genetic markers of lipid metabolism genes associated with low susceptibility to HCV infection

Due to the relation between lipids and Hepatitis C virus (HCV) life-cycle, we aimed to explore the existence of single nucleotide polymorphisms (SNPs) associated with low susceptibility to HCV-infection within lipid metabolism genes. This was a case-control study in three phases: (I) allelic frequencies of 9 SNPs within 6 genes were compared in 404 HCV-infected patients and 801 population controls; (II) results were validated in 602 HCV-infected individuals and 1352 controls; (III) results were confirmed in 30 HCV-exposed uninfected (EU) individuals. In phase I, only the LDLRAP1-rs4075184-A allele was differentially distributed in patients and controls (358 of 808 alleles [44.3%] and 807 of 1602 alleles [50.3%], respectively) (p = 0.004). In phase II, the A allele frequency was 547 of 1204 alleles (45.4%) in patients and 1326 of 2704 alleles (49.0%) in controls (p = 0.037). This frequency in EU was 36 of 60 alleles (60%), which was higher than that observed in patients from phase I (p = 0.018) and phase II (p = 0.027). The LDLRAP1-mRNA expression was lower in AA carriers than in non-AA carriers (median [Q1-Q3]: 0.85 [0.17–1.75] relative-units [ru] versus 1.71 [1.00–2.73] ru; p = 0.041). Our results suggest that LDLRAP1-rs4075184-A allele is associated with lower susceptibility to HCV-infection and with reduced expression of LDLRAP1-mRNA.

Hepatocellular Carcinoma Recurrence in HCV Patients Treated with Direct Antiviral Agents

The risk of hepatocellular carcinoma recurrence is universal regardless of the treatment modality applied, and secondary prevention is still an unmet issue even though the elimination of hepatitis C (HCV) with direct antiviral agents (DAAs) was expected to be one of the new options. Unfortunately, the impact of DAAs on hepatocellular carcinoma (HCC) development (de novo and recurrence) is still controversial. Since the first publication on the subject in 2016, almost all groups worldwide have carried out research in this field with hundreds of publications now available. This revision is focused on the impact of DAAs on HCC recurrence and aims to discuss the potential underlying mechanisms and host factors pointing out the time association phenomenon between DAA treatment and HCC recurrence. Moreover, we comment on the methodological issues that could affect the different interpretations of the published results. In conclusion, this is an area of research with potential in the understanding of the impact of factors not previously considered, and may also help change hepatocarcinogenesis tenets, such as the belief that the elimination of HCV should be used as a second prevention treatment.

Atherogenic cytokines and chemokines in chronic hepatitis C are not associated with the presence of cardiovascular diseases

There appears to be an associative link between chronic hepatitis C (CHC) and cardiovascular diseases (CVDs). However, the exact nature of the relationship between CHC and CVDs has not been elucidated. We investigated the presence of CVDs and the clinical and laboratory alterations associated with these diseases in CHC patients. Twenty-six CHC patients, 35 individuals with atherosclerosis (Athero) and 27 healthy individuals were examined for risk factors for CVD, lipid profile, atherogenic risk indexes, and insulin resistance (IR). Cardiac biomarkers and the chemokines and cytokines involved in atherosclerosis were also evaluated. A higher prevalence of prior acute myocardial infarction was found in the Athero group. Most CHC patients were infected with the hepatitis C virus genotype 1 and exhibited either no hepatic fibrosis or a mild to moderate liver fibrosis. The apolipoprotein B/apolipoprotein A-I and triglyceride/high-density lipoprotein cholesterol ratios and C-reactive protein levels were lower in CHC patients than in the Athero group. Further, IR was elevated in the CHC group and associated with the waist circumference. High GDF-15 levels were observed in the CHC group, which were inversely correlated with APOB levels. Peripheral blood mononuclear cells from CHC patients produced more IFN-γ, TNF-α and IL-6 than CAD PBMC but the production of IL-10 and IL-1β was similar. CHC and CAD groups presented similar levels of IL-8, MCP-1 and LAP-TGF-β1. Increased IR, elevated levels of GDF-15, and high production of atherogenic cytokines can be observed in Brazilian CHC patients without association with diabetes and clinical manifestation of cardiovascular diseases.

Recovery of metabolic impairment in patients who cleared chronic hepatitis C infection after direct-acting antiviral therapy

Chronic hepatitis C (CHC) is a complex disease that can affect different metabolic processes, including glucose and lipid metabolic pathways, with a significant impact on the development of heart disease and stroke. Recent therapy with direct-acting antivirals (DAAs), beyond its high efficacy on CHC eradication, showed a beneficial impact on glucose and lipid metabolism. This review aimed to describe current evidence regarding the association between hepatitis C virus (HCV) infection and impairment of glucose and lipid metabolism and also discusses potential public-health implications in light of the new DAA therapies and their availability at a global level. The excellent safety profile and efficacy of DAAs offer an exceptional opportunity to control the HCV pandemic at a global level and represent an opportunity for developing an operational research framework aimed at investigating the complex dynamics between host, pathogen and therapy that lead to metabolic damage in subjects with infectious diseases.

Lipids, glucose and iron metabolic alterations in chronic hepatitis C after viral eradication - comparison of the new direct-acting antiviral agents with the old regimens

BACKGROUND

Hepatitis C virus (HCV) is a unique virus which interacts with cholesterol, iron and insulin metabolism. There is limited data on the effects of direct-acting antiviral agents (DAAs) on metabolic profiles. We aimed at evaluating the behavior of metabolic risk factors of chronically HCV-infected patients after sustained virologic response (SVR), comparing the outcomes with the new DAAs versus the old treatment regimen Peg-interferon ± ribavirin.

METHODS

A total of 178 patients who achieved SVR and completed one year of follow-up were prospectively included in this study: group 1 with 105 patients treated with DAAs and group 2 with 73 patients treated with old regimens. Outcomes included lipid, glucose and iron metabolism variation after SVR.

RESULTS

There was a significant increase in total cholesterol in both groups (group 1: p < .001, 95% CI: 0.41-0.78; group 2: p < .001, 95% CI: 0.24-0.69). Triglyceride levels significantly decreased (p = .015, 95% CI: -0.33-0.04) in group 1 and increased (p = .014, 95% CI: 0.07-0.59) in group 2. LDL levels increased in group 1 (p = .029, 95% CI: 0.05-0.88), but no significant variation was found in group 2. No significant variation in HDL, fast glucose and iron was seen in both groups. There was a significant increase of HOMA (p = .002, 95% CI: 0.17592-0.72317) only in group 2. Ferritin serum levels significantly decreased (p < .001, 95% CI:-138.3-74.4) in group 1 but no significant variation was found in group 2.

CONCLUSION

Patients who have achieved SVR may have increased risk of cardiovascular outcomes due to development of hyperlipidemia and insulin resistance.

Worsening of Serum Lipid Profile after Direct Acting Antiviral Treatment

INTRODUCTION

Host lipid metabolism influences viral replication and lifecycle of hepatitis C virus. Our aim was to evaluate changes in glucose and lipid metabolism of patients with chronic hepatitis C after therapy with direct acting antivirals (DAA).

MATERIAL AND METHODS

We considered patients consecutively treated between January and November 2015 recording clinical data at baseline and week 24 of follow-up. Frozen serum samples were used for apolipoprotein A1 (apoA1), apolipoprotein B (apoB) and lipoprotein (a) [Lp(a)]. Wilcoxon test was utilized to estimate trends and Logistic Regression for predictors of lipid changes.

RESULTS

We enrolled 100 patients, mostly cirrhotic (81%) and with genotype 1b (59%). Ninety-three patients achieved sustained virological response (SVR), while 7 relapsed. Homeostasis model assessment of insulin resistance declined (from 3 to 2.7, p &lt; 0.001); non-high density lipoprotein (HDL) cholesterol increased from 102 ± 29 to 116 ± 35 (p &lt; 0.001), and Lp(a) from 5.6 ± 6.5 to 9.8 ± 11.5 mg/dL (p &lt; 0.001). Rise of low-density lipoprotein/HDL and apoB/apoA1 ratio were registered (from 1.79 ± 1.10 to 2.08 ± 1.05 and from 0.48 ± 0.18 to 0.53 ± 0.18 mg/dL, p &lt; 0.001). We conducted a subanalysis on patients with relapse. In this subgroup, no change of lipid profile was recorded. At multivariate analysis emerged that the addition of ribavirin to DAA, represented an independent predictor of increased Lp(a) (OR 3.982, 95% CI 1.206-13.144, p = 0.023).

CONCLUSION

DAA therapy led to reduction of insulin resistance. In contrast, pro-atherogenic lipid changes were observed in patients with SVR. Further studies will be necessary to evaluate the cardiovascular balance between amelioration of glucose metabolism and negative changes of lipid profile.

Rapid Changes in Serum Lipid Profiles during Combination Therapy with Daclatasvir and Asunaprevir in Patients Infected with Hepatitis C Virus Genotype 1b

Background/Aims

Changes in lipid profiles in patients infected with hepatitis C virus (HCV) during direct-acting antiviral therapy have been reported in recent years. However, the clinical aspects of disturbed lipid metabolism in chronic HCV infection have not been fully elucidated.

Methods

Dynamic changes in serum total, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol and apolipoprotein levels in patients infected with HCV genotype 1b were examined during combination therapy with daclatasvir (DCV) and asunaprevir (ASV).

Results

Total, LDL−, and HDL-cholesterol levels increased rapidly and persistently after week 4. Apolipoprotein (apo) A-I, apo B, apo C-II, and apo C-III levels were significantly higher at week 4 than at week 0. In contrast, apo A-II and apo E levels were significantly lower. The differences in LDL− and HDL-cholesterol levels were positively correlated with those of apo B and apo A-I, respectively. Interestingly, in patients with non-sustained virological response, these cholesterol levels decreased rapidly after viral breakthrough or viral relapse. Furthermore, similar changes were observed for apo A-I, apo B and apo C-III levels.

Conclusions

Clearance of HCV using combination therapy with DCV and ASV results in rapid changes in serum lipid profiles, suggesting an influence of HCV infection on disturbed lipid metabolism.

Chronic Hepatitis C Association with Diabetes Mellitus and Cardiovascular Risk in the Era of DAA Therapy

Patients with chronic hepatitis C have both higher prevalence of diabetes mellitus type 2 (T2DM) and increased cardiovascular risk compared to never infected people. Sustained viral response (SVR) achievement led to decreasing incidence and prevalence of T2DM during the interferon era of HCV treatment. Currently, direct-acting antiviral drugs (DAA) are the gold standard for treating HCV infection, while yielding SVR in nearly all patients. In chronic HCV patients with T2DM (prediabetes most likely too), DAA therapy is associated with both better fasting glucose and glycated hemoglobin (HbA1C) controls; thus reducing pharmacotherapy in a certain part of patients is possible. Papers mentioned in the review confirmed DAA role in both total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) increase. This alteration was accompanied by an increase in high-density lipoprotein cholesterol (HDL-C) and a decrease in triglycerides (TG) verified by most of the studies. However, the clinical significance of lipoprotein alterations caused by DAA therapy has not been explained yet. Moreover, DAA treatment of chronic hepatitis C improves hypertension control and atherosclerotic plaques. It is very likely that DAA therapeutic regimens will decrease both T2DM prevalence and cardiovascular risk in chronic hepatitis C patients; further research, however, is needed.

Exploring lipid and apolipoprotein levels in chronic hepatitis C patients according to their response to antiviral treatment

BACKGROUND

Hepatitis C virus is known to be highly dependent of lipid metabolism to infect new cells and replicate.

AIMS

To investigate lipid and apolipoprotein profile in chronic HCV patients according to treatment response.

METHODS

Patients recruited from the Hepatitis Treatment Center at Niteroi (Brazil) who received interferon (IFN)-based therapies were separated into two groups, those who achieved sustained virological response (SVR) or not (non-SVR). Another group of patients treated with IFN-free direct-acting antiviral (DAA) therapies was followed from before starting the treatment until one year after therapy. Triglycerides, total cholesterol and fractions were determined by colorimetric and/or electrophoresis techniques. Lecithin cholesterol acyltransferase (LCAT) activity and serum levels of apolipoproteins A1, A2, B, C2, C3 and E were assessed by enzymatic and multiplex assays, respectively.

RESULTS

We studied 114 patients, and SVR was reached in 28 (39.4%) patients treated with IFN-therapy and in all (100%) patients who received DAA. Non-SVR patients (n = 43) presented altered liver parameters post-treatment. Levels of total cholesterol, LDL-C, VLDL-C and triglycerides were significant higher in SVR group. In contrast, LCAT activity and HDL-C levels were elevated in non-SVR patients. Only apolipoproteins B, C2 and C3 levels were increased in SVR group. The follow-up of SVR-DAA patients (n = 43) revealed a significant and progressive increase in serum levels of total cholesterol, LDL-C, VLDL-C and triglycerides.

CONCLUSIONS

After a successful treatment, chronic hepatitis C patients experienced a reestablishment of lipid metabolism. Our results suggest that the monitoring of serum lipids could be a practical and routine laboratory tool to be applied during the treatment follow-up.

Hidden heterogeneity in Alzheimer's disease: Insights from genetic association studies and other analyses

Despite evident success in clarifying many important features of Alzheimer's disease (AD) the efficient methods of its prevention and treatment are not yet available. The reasons are likely to be the fact that AD is a multifactorial and heterogeneous health disorder with multiple alternative pathways of disease development and progression. The availability of genetic data on individuals participated in longitudinal studies of aging health and longevity, as well as on participants of cross-sectional case-control studies allow for investigating genetic and non-genetic connections with AD and to link the results of these analyses with research findings obtained in clinical, experimental, and molecular biological studies of this health disorder. The objective of this paper is to perform GWAS of AD in several study populations and investigate possible roles of detected genetic factors in developing AD hallmarks and in other health disorders. The data collected in the Framingham Heart Study (FHS), Cardiovascular Health Study (CHS), Health and Retirement Study (HRS) and Late Onset Alzheimer's Disease Family Study (LOADFS) were used in these analyses. The logistic regression and Cox's regression were used as statistical models in GWAS. The results of analyses confirmed strong associations of genetic variants from well-known genes APOE, TOMM40, PVRL2 (NECTIN2), and APOC1 with AD. Possible roles of these genes in pathological mechanisms resulting in development of hallmarks of AD are described. Many genes whose connection with AD was detected in other studies showed nominally significant associations with this health disorder in our study. The evidence on genetic connections between AD and vulnerability to infection, as well as between AD and other health disorders, such as cancer and type 2 diabetes, were investigated. The progress in uncovering hidden heterogeneity in AD would be substantially facilitated if common mechanisms involved in development of AD, its hallmarks, and AD related chronic conditions were investigated in their mutual connection.

Small heterodimer partner 1 directly interacts with NS5A viral protein and has a key role in HCV related liver cell transformation

HCV life cycle is strictly correlated with the hepatocyte lipid metabolism; moreover, the progression of HCV chronic hepatitis is accelerated by the presence of liver steatosis. Among the steatogenic genes deregulated during the HCV infection one of the most attractive is the Small Heterodimer Protein 1 (SHP1; NR0B2), that is involved in a remarkable number of metabolic functions. HCV NS5A is an essential and integral component of the HCV membranous-web replicon complex (RC) and plays an essential role to transfer the viral genome from the RCs to the surface of the lipid droplets (LDs) that, in turn, play a key function during HCV life cycle.

With the help of a HCV infection model, we demonstrate a functional interaction between SHP1 and HCV NS5A protein. SHP1 silencing (siSHP1) reversed the pro-oncogenic effects of HCV infection, inducing a significant decrease in liver lipid accumulation and in NS5A protein expression. Moreover, siSHP1 causes a strong modulation of some genes involved in HCV-related EMT, such as: HNF4, a central regulators of hepatocyte differentiation, E-Cadherin, SNAILs.

Our data suggest that SHP1 results not only to be strictly connected to the pathogenesis of HCV-related liver steatosis, but also to its progression towards the liver transformation.

In vivo analysis at the cellular level reveals similar steatosis induction in both hepatitis C virus genotype 1 and 3 infections

Steatosis is a frequent histological feature of hepatitis C virus (HCV) infection. Cohort studies of patients with chronic hepatitis C identified HCV genotype 3 (HCV GT3) as the prevalent steatotic genotype. Moreover, Huh-7 cells over-expressing HCV GT3 core protein accumulate more triglyceride in larger lipid droplets than cells expressing core proteins of other HCV genotypes. However, little is known about the relationship of steatosis and HCV infection at the cellular level in vivo. In this study, we used highly sensitive multiplex in situ hybridization methodology together with lipid staining to investigate HCV-induced lipid droplet accumulation at the cellular level in liver biopsies. Consistent with previous reports, histological steatosis grades were significantly higher in GT3 compared to GT1 infected livers, but independent of viral load. Using nile red lipid stainings, we observed that the frequency of lipid droplet containing cells was similar in HCV GT1- and HCV GT3-infected livers. Lipid droplet formation preferentially occurred in HCV-infected cells irrespective of the genotype, but was also observed in noninfected cells. These findings demonstrate that the main difference between GT1- and GT3-induced steatosis is the size of lipid droplets, but not the number or relative distribution of lipid droplets in infected vs uninfected hepatocytes.

Prevalence of pruritus in patients with chronic liver disease: A multicenter study

AIM

Pruritus is a common comorbidity in chronic liver disease. The aim of this study was to clarify the prevalence of pruritus and its characteristics in patients with chronic liver disease.

METHODS

A total of 1631 patients with chronic liver disease who attended one of nine joint-research facilities from January to June 2016 were enrolled. We investigated the prevalence of pruritus, itch location, itch duration, daily itch fluctuation, seasonal itch exacerbation, treatment drugs, and therapeutic effects using a medical interview questionnaire.

RESULTS

The median age was 66 years and 890 (54.6%) patients were women. The prevalence of pruritus was 40.3% (658/1631), and it differed according to the underlying liver disease. The most frequent body location for pruritus was on the back (63.1%). Pruritus duration was more than 6 months in 252 (38.3%) patients. The severity of pruritus, assessed using a visual analog scale, was higher during the day than at night (median, 4 vs. 3, P < 0.001). Seasonal exacerbation was observed in 296 (45.0%) patients. Although 301 (45.7%) patients were treated with antipruritic agents, 57.8% (174/301) patients reported an insufficient effect. Active hepatitis B virus infection (odds ratio [OR], 2.51; P = 0.043), primary biliary cholangitis (OR, 3.69; P = 0.018), diabetes (OR, 1.57; P = 0.010), and aspartate aminotransferase ≥60 U/L (OR, 2.06; P = 0.011) were independent factors associated with pruritus.

CONCLUSION

The prevalence of pruritus varies according to the chronic liver disease etiology. Underlying liver disease, aspartate aminotransferase ≥60 U/L, and comorbid diabetes are factors associated with pruritus in patients with chronic liver disease.

Changes in serum lipid profiles caused by three regimens of interferon-free direct-acting antivirals for patients infected with hepatitis C virus

AIM

Serum low-density lipoprotein cholesterol (LDL-C) increases during treatment of chronic hepatitis C (CHC) with interferon-free direct-acting antivirals (DAAs). We sought to compare the changes of serum lipid profiles caused by three regimens.

METHODS

A total of 216 CHC patients were enrolled. Among 170 patients infected with hepatitis C virus (HCV) genotype 1b, 85 received daclatasvir plus asunaprevir (DCV/ASV) and 85 received sofosbuvir plus ledipasvir (SOF/LDV). Forty-six infected with HCV genotype 2 received sofosbuvir plus ribavirin (SOF/RBV). Serum total cholesterol (TC), LDL-C, high-density lipoprotein cholesterol, and triglyceride were measured at baseline and 4, 8, 12 (for all regimens), and 24 weeks (for DCV/ASV) during treatment (4w, 8w, 12w, and 24w, respectively) and 12 and 24 weeks after treatment (p12w and p24w, respectively).

RESULTS

In 69 (81.2%) patients who received DCV/ASV and achieved a sustained virologic response at 24 weeks after the end of treatment (SVR24), TC and LDL-C increased significantly from baseline to p24w. In 84 (98.8%) treated with SOF/LDV who achieved SVR24, TC and LDL-C increased significantly from baseline to 8w, and TC decreased significantly from 8w to p12w. The 45 (97.8%) who received SOF/RBV and achieved SVR24 showed no significant changes. At 12w, TC and LDL-C increased to a greater degree in patients receiving SOF/LDV than in those receiving DCV/ASV or SOF/RBV.

CONCLUSION

During treatment with DAAs, the serum lipid profile may reflect not only recovery from the disruption of lipid metabolism induced by HCV, but also the pharmacological effects of DAAs. Further investigations are needed to elucidate the effect of DAAs on serum lipid profiles.

Newly discovered hepatitis C virus minicores circulate in human blood

Hepatitis C virus (HCV) is one of the most prevalent causes of chronic blood‐borne infections worldwide. Despite developments of highly effective treatments, most infected individuals are unaware of their infection. Approximately 75% of infections are in low‐ and middle‐income countries; therefore, continuing research in HCV molecular virology and the development of vaccines and affordable diagnostics is required to reduce the global burden. Various intracellular forms of the HCV nucleocapsid (core) protein are produced in cell culture; these comprise the conventional p21 core and the newly discovered shorter isoforms (minicores). Minicores lack the N‐terminus of p21 core. This study was conducted to determine if minicores are secreted in cell culture and more importantly if they circulate in the blood of individuals infected with HCV. We also developed a new monoclonal antibody that detects minicores targeting a C‐terminal region common to p21 core and minicores. Direct evidence of minicores requires western blot analysis to distinguish the detection of p21 core from minicores. However, the sensitivity for western blot detection of HCV proteins from blood is nil without their prior purification/enrichment from blood. Therefore, we developed a purification method based on a heparin/Mn⁺² precipitation of apolipoprotein B‐containing lipoproteins because HCV is thought to circulate as a hybrid lipoviral particle. Minicores are secreted in culture when cells are grown in the presence of human serum. The heparin/Mn⁺² precipitate from HCV‐infected cell culture supernatants and from the blood of 4 patients with high‐titer genotype‐1 HCV contained minicores. Conclusion: Minicores are major newly discovered HCV proteins that are secreted and circulate in blood during natural infections. Minicore proteins have translational potential as targets in diagnostic assays and in vaccine development. (Hepatology Communications 2018;2:21–28)

Long Non-coding RNAs in Hepatitis C Virus-Infected Cells

Hepatitis C virus (HCV) often leads to a chronic infection in the liver that may progress to steatosis, fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Several viral and cellular factors are required for a productive infection and for the development of liver disease. Some of these are long non-coding RNAs (lncRNAs) deregulated in infected cells. After HCV infection, the sequence and the structure of the viral RNA genome are sensed to activate interferon (IFN) synthesis and signaling pathways. These antiviral pathways regulate transcription of several cellular lncRNAs. Some of these are also deregulated in response to viral replication. Certain viral proteins and/or viral replication can activate transcription factors such as MYC, SP1, NRF2, or HIF1α that modulate the expression of additional cellular lncRNAs. Interestingly, several lncRNAs deregulated in HCV-infected cells described so far play proviral or antiviral functions by acting as positive or negative regulators of the IFN system, while others help in the development of liver cirrhosis and HCC. The study of the structure and mechanism of action of these lncRNAs may aid in the development of novel strategies to treat infectious and immune pathologies and liver diseases such as cirrhosis and HCC.

Treatment-Induced Viral Cure of Hepatitis C Virus-Infected Patients Involves a Dynamic Interplay among three Important Molecular Players in Lipid Homeostasis: Circulating microRNA (miR)-24, miR-223, and Proprotein Convertase Subtilisin/Kexin Type 9

In patients with chronic hepatitis C virus (HCV) infection, viral hijacking of the host-cell biosynthetic pathways is associated with altered lipid metabolism, which contributes to disease progression and may influence antiviral response. We investigated the molecular interplay among four key regulators of lipid homeostasis [microRNA (miR)-122, miR-24, miR-223, and proprotein convertase subtilisin/kexin type 9 (PCSK9)] in HCV-infected patients (n=72) who achieved a treatment-based viral cure after interferon-based therapy with first-generation direct-acting antivirals. Real-time PCR was used to quantify microRNA plasma levels, and ELISA assays were used to determine plasma concentrations of PCSK9. We report that levels of miR-24 and miR-223 significantly increased in patients achieving sustained virologic response (SVR), whereas the levels of miR-122, a liver-specific cofactor for HCV infection, decreased in these patients. PCSK9 concentrations were significantly increased in SVRs, suggesting that PCSK9 may help impede viral infection. The modulatory effect of PCSK9 on HCV infection was also demonstrated in the context of HCV-infected Huh-7.5.1 cells employing recombinant human PCSK9 mutants. Together, these results provide insights into a novel coordinated interplay among three important molecular players in lipid homeostasis - circulating miR-24, miR-223 and PCSK9 - whose regulation is affected by HCV infection and treatment-based viral cure.

Analysis of Hepatitis C Virus Particle Heterogeneity in Immunodeficient Human Liver Chimeric fah-/- Mice

BACKGROUND & AIMS

Hepatitis C virus (HCV) is a leading cause of chronic liver diseases and the most common indication for liver transplantation in the United States. HCV particles in the blood of infected patients are characterized by heterogeneous buoyant densities, likely owing to HCV association with lipoproteins. However, clinical isolates are not infectious in vitro and the relative infectivity of the particles with respect to their buoyant density therefore cannot be determined, pointing to the need for better in vivo model systems.

METHODS

To analyze the evolution of the buoyant density of in vivo-derived infectious HCV particles over time, we infected immunodeficient human liver chimeric fumaryl acetoacetate hydrolase-/- mice with J6/JFH1 and performed ultracentrifugation of infectious mouse sera on isopicnic iodixanol gradients. We also evaluated the impact of a high sucrose diet, which has been shown to increase very-low-density lipoprotein secretion by the liver in rodents, on lipoprotein and HCV particle characteristics.

RESULTS

Similar to the severe combined immunodeficiency disease/Albumin-urokinase plasminogen activator human liver chimeric mouse model, density fractionation of infectious mouse serum showed higher infectivity in the low-density fractions early after infection. However, over the course of the infection, viral particle heterogeneity increased and the overall in vitro infectivity diminished without loss of the human liver graft over time. In mice provided with a sucrose-rich diet we observed a minor shift in HCV infectivity toward lower density that correlated with a redistribution of triglycerides and cholesterol among lipoproteins.

CONCLUSIONS

Our work indicates that the heterogeneity in buoyant density of infectious HCV particles evolves over the course of infection and can be influenced by diet.