Modulation of host lipid metabolism by hepatitis C virus: Role of new therapies

Association of serum lipid profile with liver fibrosis in HCV‑coinfected HIV patients on suppressive anti‑retroviral therapy

Hepatitis C virus (HCV) coinfection in individuals living with human immunodeficiency virus (HIV) (PLWH) may affect lipid metabolism and accelerate the progression of chronic hepatitis. Therefore, the identification of risk factors for progressive liver disease is needed. The present study aimed to examine the prevalence and clinical features associated with liver fibrosis in HCV-coinfected HIV patients, including metabolic markers. A total of 105 patients coinfected with HIV and HCV were recruited and liver fibrosis was assessed using the fibrosis-4 (FIB-4) score and aspartate aminotransferase-to-platelet ratio index (APRI). Logistic regression analyses indicated that patients aged >50 years and with a CD4+ cell count <350 cells/µl had an 11.4-times higher (P=0.001) and a 5.7-times higher (P=0.017) risk of liver fibrosis, as determined by FIB-4 score, compared to patients aged ≤40 years and a CD4+ cell count of ≥350 cells/µl, respectively. In addition, patients naïve to HCV treatment or receiving treatment had 5.4- and 12.7-times higher risks for liver fibrosis, as determined by APRI, than those with sustained virologic response (SVR) (P=0.003 and P=0.033, respectively). Univariate analysis indicated lower risks of liver fibrosis, as determined by APRI, in the patients with abnormally high levels of cholesterol, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) than those with normal levels [odds ratio (OR) 0.3, 95% confidence interval (CI) 0.1-0.9, P=0.037; OR 0.4, 95% CI 0.2-0.9, P=0.041; OR 0.2, 95% CI 0.1-0.5, P=0.001] and multivariate analysis suggested only patients with high levels of LDL had a lower risk for liver fibrosis determined by APRI (OR 0.1, 95% CI 0.3-0.8, P=0.029). Consistently, serum levels of cholesterol, HDL and LDL were significantly lower in the patient groups with more advanced fibrosis, evaluated by FIB-4 score and APRI, than those without liver fibrosis and the levels of cholesterol and LDL in the patients achieving SVR were higher than those with no response or not receiving treatment (all P<0.05). In conclusion, the present study identified serum lipid levels as associated factors of hepatic fibrosis, together with age, CD4+ cell count and HCV treatment status, in HCV-coinfected PLWH on long-term suppressive anti-retroviral therapy.

Unveiling Actin Cytoskeleton Role in Mediating Chikungunya-Associated Arthritis: An Integrative Proteome-Metabolome Study

Background: Chikungunya is a zoonotic disease caused by the Chikungunya virus (CHIKV), primarily transmitted to humans through infected Aedes mosquitoes. The infection is characterized by symptoms such as high fever, musculoskeletal pain, polyarthritis, and a rash, which can lead to severe complications such as encephalitis, meningitis, and even fatalities. While many disease manifestations resemble those of other viral infections, chronic arthritis caused by CHIKV is unique, and its molecular mechanisms remain ill-defined. Materials and Methods: Proteomics data from both cellular and patient levels of CHIKV infection were curated from PubMed and screened using inclusion and exclusion criteria. Patient serum proteomics data obtained from P RIDE underwent reanalysis using Proteome Discoverer 2.2. Enrichment and protein-protein interaction network analysis were conducted on differentially expressed proteins from both serum and cellular datasets. Metabolite data from CHIKV-infected patients were further retrieved, and their protein binding partners were identified using BindingDB. The protein-metabolite interaction pathway was further developed using MetaboAnalyst. Results: The proteomics data analysis revealed differential expression of proteins involved in critical host mechanisms, such as cholesterol metabolism and mRNA splicing, during CHIKV infection. Consistent upregulation of two actin cytoskeleton proteins, TAGLN2 and PFN1, was noted in both serum and cellular datasets, and their upregulations are associated with arthritis. Furthermore, alterations in purine metabolism were observed in the integrative proteome-metabolome analysis, correlating with cytoskeletal remodelling. Conclusion: Collectively, this integrative view sheds light on the involvement of actin cytoskeleton remodeling proteins and purine metabolic pathways in the development of arthritis during CHIKV infection.

Myocardial perfusion reserve in patients with chronic hepatitis C before and after direct-acting antiviral treatment-a pilot study

INTRODUCTION

Patients with chronic hepatitis C (CHC) have an increased risk of atherosclerotic cardiovascular disease which may be due to inflammation and endothelial dysfunction caused by the chronic infection. In this prospective pilot study, we assessed, for the first time among patients with CHC the myocardial perfusion reserve (MPR) by Rubidium-82 (⁸² Rb) positron emission tomography (PET)/computed tomography (CT) before and after direct-acting antiviral (DAA) treatment and compared them with biomarkers of systemic inflammation and endothelial dysfunction.

METHODS

We included 10 patients with CHC who received 8 or 12 weeks of DAA treatment. To obtain the MPR, a cardiac ⁸² Rb PET/CT scan at rest and adenosine-induced stress was performed at baseline and between 12 and 24 weeks post DAA treatment. Additionally, markers of endothelial dysfunction and inflammation were measured at baseline and 12 weeks after DAA treatment.

RESULTS

All 10 patients achieved cure and the median age was 50 (range: 40-62 years). The median MPR before treatment was 3.1 (range: 2.3-4.8) compared to 2.9 (range: 2.2-4.1) after DAA treatment p = 0.63. Also, cure after DAA treatment was not associated with an overall significant decrease in markers of endothelial dysfunction and inflammation.

DISCUSSION

Cure after DAA treatment in patients with CHC did not improve coronary microvascular function nor did it lead to a decrease in soluble markers of cardiovascular risk in the given time frame where the patients were followed. It should be noted, that MPR before DAA treatment was in the normal range. Considering the small sample size and short follow-up time, further studies are warranted to determine if viral clearance has an effect on coronary microvascular function and endothelial dysfunction.

Non-Targeted Metabolomic Analysis of Chicken Kidneys in Response to Coronavirus IBV Infection Under Stress Induced by Dexamethasone

Stress in poultry can lead to changes in body metabolism and immunity, which can increase susceptibility to infectious diseases. However, knowledge regarding chicken responses to viral infection under stress is limited. Dexamethasone (Dex) is a synthetic glucocorticoid similar to that secreted by animals under stress conditions, and has been widely used to induce stress in chickens. Herein, we established a stress model in 7-day-old chickens injected with Dex to elucidate the effects of stress on IBV replication in the kidneys. The metabolic changes, immune status and growth of the chickens under stress conditions were comprehensively evaluated. Furthermore, the metabolic profile, weight gain, viral load, serum cholesterol levels, cytokines and peripheral blood lymphocyte ratio were compared in chickens treated with Dex and infected with IBV. An LC-MS/MS-based metabolomics method was used to examine differentially enriched metabolites in the kidneys. A total of 113 metabolites whose abundance was altered after Dex treatment were identified, most of which were lipids and lipid-like molecules. The principal metabolic alterations in chicken kidneys caused by IBV infection included fatty acid, valine, leucine and isoleucine metabolism. Dex treatment before and after IBV infection mainly affected the host’s tryptophan, phenylalanine, amino sugar and nucleotide sugar metabolism. In addition, Dex led to up-regulation of serum cholesterol levels and renal viral load in chickens, and to the inhibition of weight gain, peripheral blood lymphocytes and IL-6 production. We also confirmed that the exogenous cholesterol in DF-1 cells promoted the replication of IBV. However, whether the increase in viral load in kidney tissue is associated with the up-regulation of cholesterol levels induced by Dex must be demonstrated in future experiments. In conclusion, chick growth and immune function were significantly inhibited by Dex. Host cholesterol metabolism and the response to IBV infection are regulated by Dex. This study provides valuable insights into the molecular regulatory mechanisms in poultry stress, and should support further research on the intrinsic link between cholesterol metabolism and IBV replication under stress conditions.

Coronavirus Infection and Cholesterol Metabolism

Host cholesterol metabolism remodeling is significantly associated with the spread of human pathogenic coronaviruses, suggesting virus-host relationships could be affected by cholesterol-modifying drugs. Cholesterol has an important role in coronavirus entry, membrane fusion, and pathological syncytia formation, therefore cholesterol metabolic mechanisms may be promising drug targets for coronavirus infections. Moreover, cholesterol and its metabolizing enzymes or corresponding natural products exert antiviral effects which are closely associated with individual viral steps during coronavirus replication. Furthermore, the coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 infections are associated with clinically significant low cholesterol levels, suggesting cholesterol could function as a potential marker for monitoring viral infection status. Therefore, weaponizing cholesterol dysregulation against viral infection could be an effective antiviral strategy. In this review, we comprehensively review the literature to clarify how coronaviruses exploit host cholesterol metabolism to accommodate viral replication requirements and interfere with host immune responses. We also focus on targeting cholesterol homeostasis to interfere with critical steps during coronavirus infection.

Serum lipid profile in HCV patients treated with direct-acting antivirals: a systematic review and meta-analysis

Although direct-acting antivirals are very effective and safe drugs, several authors have reported the alteration of lipid profile during and after anti-HCV therapy suggesting a potential impact on the risk of cardiovascular events. We performed a systematic review and meta-analysis of observational studies to investigate the magnitude and temporal trend of lipid profile changes in DAA treated patients. All selected studies included data on lipid profile before starting therapy and at least one follow-up assessment during or after antiviral treatment. We identified 14 studies (N = 1537 patients) after removing duplicates. Pooled data showed an increase in total cholesterol 4 weeks after starting therapy (+ 15.86 mg/dl; 95% CI + 9.68 to 22.05; p < 0.001) and 12 weeks after treatment completion (+ 17.05 mg/dl; 95% CI + 11.24 to 22.85; p < 0.001). LDL trend was similar to the total cholesterol change in overall analysis. A mean increase in HDL-cholesterol of 3.36 mg/dl (95% CI + 0.92 to 5.79; p = 0.07) was observed after 12 weeks of treatment, whereas at SVR24 HDL difference was + 4.34 mg/dl (95% CI + 1.40 to 7.28; p = 0.004).Triglycerides did not show significant changes during treatment and after treatment completion. DAAs induce mild lipid changes in chronic hepatitis C patients treated with DAAs, which may persist after treatment completion.

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.

Paper spray mass spectrometry utilizing Teslin® substrate for rapid detection of lipid metabolite changes during COVID-19 infection

The SARS-CoV-2 virus is known as the causal agent for the current COVID-19 global pandemic. The majority of COVID-19 patients develop acute respiratory distress syndrome (ARDS), while some experience a cytokine storm effect, which is considered as one of the leading causes of patient mortality. Lipids are known to be involved in the various stages of the lifecycle of a virus functioning as receptors or co-receptors that controls viral propagation inside the host cell. Therefore, lipid-related metabolomics aims to provide insight into the immune response of the novel coronavirus. Our study has focused on determination of the potential metabolomic biomarkers utilizing a Teslin® Substrate in paper spray mass spectrometry (PS-MS) for the development of a rapid detection test within 60 seconds of analysis time. In this study, results were correlated with PCR tests to reflect that the systemic responses of the cells were affected by the COVID-19 virus.

Reprogramming of cellular metabolic pathways by human oncogenic viruses

Oncogenic viruses, like all viruses, relies on host metabolism to provide the metabolites and energy needed for virus replication. Many DNA tumor viruses and retroviruses will reprogram metabolism during infection. Additionally, some viral oncogenes may alter metabolism independent of virus replication. Virus infection and cancer development share many similarities regarding metabolic reprogramming as both processes demand increased metabolic activity to produce biomass: cell proliferation in the case of cancer and virion production in the case of infection. This review discusses the parallels in metabolic reprogramming between human oncogenic viruses and oncogenesis.

Antiviral treatment does not improve subclinical atheromatosis in patients with chronic hepatitis caused by hepatitis C virus

INTRODUCTION

Chronic infection with hepatitis C virus is a risk factor for developing atheromatous plaques, although the possible effect of virus clearance is unknown. Our aim was to determine whether or not subclinical atheromatosis improved and there was any modification in the composition of the plaques 12 months after eradication of hepatitis C virus by direct-acting antiviral agents.

MATERIALS AND METHODS

Prospective study that included 85 patients with chronic hepatitis C virus infection in different stages of fibrosis who were on direct-acting antiviral agents. Patients with a cardiovascular history, diabetes and kidney disease were excluded. An arterial ultrasound (carotid and femoral) was performed to diagnose atheromatous plaques (defined as intima-media thickness ≥1.5mm) and the composition (percentage of lipids, fibrosis and calcium with HEMODYN4 software) was analysed at the beginning of the study and 12 months after stopping the therapy.

RESULTS

After follow-up no changes were detected in the intima-media thickness (0.65mm vs. 0.63mm, P=.240) or in the presence of plaques (65.9% vs 71.8%, P=.063). There was also no significant change in their composition or affected vascular territory, with an increase in blood lipid profile (P<.001) after 12 months of treatment. These results were confirmed in subgroups by severity of liver disease.

DISCUSSION

The eradication of hepatitis C virus by direct-acting antiviral agents does not improve the atheroma plaques and nor does it vary their composition, regardless of liver fibrosis. More prospective studies are needed to evaluate residual cardiovascular risk after virus eradication.

Phospholipid profiles and hepatocellular carcinoma risk and prognosis in cirrhotic patients

Background

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Phospholipids are now well-recognised players in tumour progression. Their metabolic tissue alterations can be associated with plasmatic modifications. The aim of this study was to evaluate the potential of the plasma phospholipid profile as a risk and prognostic biomarker in HCC.

Methods

Ninety cirrhotic patients with (cases) or without HCC (controls) were studied after matching for inclusion centre, age, gender, virus infection, cirrhosis duration and Child-Pugh grade. High-performance liquid chromatography coupled with tandem-mass spectrometry was used to quantify the main species of seven categories of phospholipids in plasma.

Results

Elevated concentrations of phosphatidylcholine (PC) 16:0/16:1 (p=0.0180), PC 16:0/16:0 (p=0.0327), PC 16:0/18:1 (p=0.0264) and sphingomyelin (SM) 18:2/24:1 (p=0.0379) and low concentrations of lysophosphatidylcholine 20:4 (0.0093) and plasmalogen-phosphatidylethanolamine (pPE) 16:0/20:4 (p=0.0463), pPE 18:0/20:4 (p=0.0077), pPE 18:0/20:5 (p=0.0163), pPE 18:0/20:3 (p=0.0463) discriminated HCC patients from cirrhotic controls. Two ceramide species were associated with increased HCC risk of death while lysophospholipids, a polyunsaturated phosphatidylinositol, some PC and SM species were associated with low risk of death in HCC patients in 1 and/or 3 years.

Conclusion

This study identified phospholipid profiles related to HCC risk in liver cirrhotic patients and showed for the first time the potential of some phospholipids in predicting HCC patient mortality.

Chronic hepatitis C infection: An independent risk factor for subclinical atheromatosis

BACKGROUND

The association between subclinical atheromatosis and chronic hepatitis C virus (HCV) infection is unknown but is relevant now that antivirals are improving the survival of patients with the infection.

OBJECTIVES

To determine whether HCV is an independent risk factor for subclinical atheromatosis and to analyse the changes in lipid profiles according to viral RNA levels and hepatic fibrosis.

PATIENTS AND METHODS

We conducted an observational, cross-sectional study that included 102 HCV-positive patients and 102 HCV-negative patients with parity in terms of sex and age, with no history of cardiovascular or kidney disease or diabetes. Atheromatosis (the presence of atheromatous plaques) and the carotid intima-media thickness (CIMT) were assessed using ultrasonography of the carotid and femoral arteries.

RESULTS

There was a greater presence of atheromatosis in any vascular territory in HCV-positive patients than in the patients without infection (58.8% vs. 28.4%, p<.0001). In the multivariate analysis, the factors significantly associated with atheromatosis included HCV infection (OR, 14.37 [5.5-37.3]; p<.001), age (OR, 1.12 [1.1-1.2]; p<.001), male sex (OR, 4.32 [1.9-9.5]; p<.001) and the triglyceride/HDL cholesterol coefficient (TG/HDL-indirect indicator of insulin resistance) (OR, 1.34 [1.1-1.6]; p=.007). The HCV-positive patients with atheromatous plaques had a higher TG/HDL coefficient but no significant differences in terms of the viral load or degree of hepatic fibrosis and with a 'low risk' lipid profile.

CONCLUSIONS

HCV infection is an independent risk factor for subclinical atheromatosis. Systemic arterial ultrasonography for this population improves the cardiovascular risk assessment beyond lipid profile abnormalities and the risk calculation using SCORE tables.

Transcriptional Regulatory Networks in Hepatitis C Virus-induced Hepatocellular Carcinoma

Understanding the transcriptional regulatory elements that influence the progression of liver disease in the presence of hepatitis C virus (HCV) infection is critical for the development of diagnostic and therapeutic approaches. Systems biology provides a roadmap by which these elements may be integrated. In this study, a previously published dataset of 124 microarray samples was analyzed in order to determine differentially expressed genes across four tissue types/conditions (normal, cirrhosis, cirrhosis HCC, and HCC). Differentially expressed genes were assessed for their functional clustering and those genes were annotated with their potential transcription factors and miRNAs. Transcriptional regulatory networks were constructed for each pairwise comparison between the 4 tissue types/conditions. Based on our analysis, it is predicted that the disruption in the regulation of transcription factors such as AP-1, PPARγ, and NF-κB could contribute to the liver progression from cirrhosis to steatosis and eventually to HCC. Whereas the condition of the liver digresses, the downregulation of miRNAs' (such as miR-27, Let-7, and miR-106a) expression makes the transition of the liver through each pathological stage more apparent. This preliminary data can be used to guide future experimental work. An understanding of the transcriptional regulatory attributes acts as a road map to help design interference strategies in order to target the key regulators of progression of HCV induced HCC.

Genotype specific peripheral lipid profile changes with hepatitis C therapy

AIM

To evaluate magnitude/direction of changes in peripheral lipid profiles in patients undergoing direct acting therapy for hepatitis C by genotype.

METHODS

Mono-infected patients with hepatitis C were treated with guideline-based DAAs at a university-based liver clinic. Patient characteristics and laboratory values were collected before and after the treatment period. Baseline demographics included age, ethnicity, hypertension, diabetes, hyperlipidemia, treatment regimen, and fibrosis stage. Total cholesterol (TCHOL), high density lipoprotein (HDL), low density lipoprotein (LDL), triglycerides (TG), and liver function tests were measured prior to treatment and ETR. Changes in lipid and liver function were evaluated by subgroups with respect to genotype. Mean differences were calculated for each lipid profile and liver function component (direction/magnitude). The mean differences in lipid profiles were then compared between genotypes for differences in direction/magnitude. Lipid profile and liver function changes were evaluated with Levene’s test and student’s t test. Mean differences in lipid profiles were compared between genotypes using ANOVA, post hoc analysis via the Bonferroni correction or Dunnett T3.

RESULTS

Three hundred and seventy five patients enrolled with 321 (85.6%) achieving sustained-viral response at 12 wk. 72.3% were genotype 1 (GT1), 18.1% genotype 2 (GT2), 9.7% genotype 3 (GT3). Baseline demographics were similar. Significant change in lipid profiles were seen with GT1 and GT3 (ΔGT1, p and ΔGT3, p), with TCHOL increasing (+5.3, P = 0.005 and +16.1, P < 0.001), HDL increasing (+12.5, P < 0.001 and +7.9, P = 0.038), LDL increasing (+7.4, P = 0.058 and +12.5, P < 0.001), and TG decreasing (-5.9, P = 0.044 and -9.80 P = 0.067). Among genotypes (ΔGT1 v. ΔGT2 v. ΔGT3, ANOVA), significant mean differences were seen with TCHOL (+5.3 v. +0.1 v. +16.1, P = 0.017) and HDL (+12.3 v. +2 v. +7.9, P = 0.040). Post-hoc, GT3 was associated with a greater increase in TCHOL than GT1 and GT2 (P = 0.028 and P = 0.019).

CONCLUSION

Successful DAA therapy results in increases in TCHOL, LDL, and HDL and decrease in TG, particularly in GT1/GT3. Changes are most pronounced in GT3.

Hepatitis C virus core protein impairs metabolic disorder of liver cell via HOTAIR-Sirt1 signalling

It has been suggested that Hepatitis C virus (HCV) core protein is associated with metabolic disorders of liver cell. However, the precise mechanism is still unclear. The aim of the present study was to explore the impact of HCV core protein on hepatocyte metabolism by HepG2 and the possible involvement of long non-coding (lnc) RNAs in this process. The effect of HCV core protein on lncRNAs expression was examined with quantitative RT-PCR (qRT-PCR). Manipulation of HVC core protein and lncRNA HOTAIR was to evaluate the role of interaction between them on cell metabolism-related gene expression and cellular metabolism. The potential downstream Sirt1 signal was examined by western blotting and qRT-PCR. Our data suggested that suppression of HOTAIR abrogates HCV core protein-induced reduction in Sirt1 and differential expression of glucose- and lipid-metabolism-related genes. Also it benefits for metabolic homoeostasis of hepatocyte indicated by restoration of cellular reactive oxygen species (ROS) level and NAD/NADH ratio. By manipulation of HOTAIR, we concluded that HOTAIR negatively regulates Sirt1 expression through affecting its promotor methylation. Moreover, overexpression of Sirt1 reverses pcDNA-HOTAIR-induced glucose- and lipid-metabolism-related gene expression. Our study suggests that HCV core protein causes dysfunction of glucose and lipid metabolism in liver cells through HOTAIR-Sirt1 signalling pathway.

Rotavirus replication and the role of cellular lipid droplets: New therapeutic targets?

Rotaviruses (RVs) are a major cause of acute gastroenteritis in infants and young children worldwide. These viruses infect the villous epithelium of the small intestine. Part of their replication occurs in cytoplasmic inclusion bodies termed viroplasms. Viroplasms and the lipid droplets (LDs) of cellular organelles are known to interact both physically and functionally. Compounds interfering with the homoeostasis of LDs significantly decrease the production of infectious RV progeny. There is considerable scope for more detailed exploration of such compounds as potential antiviral agents for a disease for which at present no specific therapy exists.