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1.
LDL particle size and antioxidant HDL function improve after sustained virological response in patients with chronic HCV.
Vargas, JI, Rivera, K, Arrese, M, Benitez, C, Barrera, F, Hugo, M, Arab, JP, Pino, K, Barrera, A, Lopez-Lastra, M, et al
Annals of hepatology. 2022;(1):100555
Abstract
HCV infection is associated with an increased incidence of cardiovascular (CV) events. Mechanisms underlying this association remain unknown. In our study, twenty HCV patients (median age 60.5 years, 65% male and 80% with cirrhosis) were evaluated prior, during and after direct-acting antiviral treatment. Ninety percent of patients achieved sustained virological response (SVR). Significant changes were observed in LDL particle size index, measured by LDL-C/apoB ratio, which increased after treatment (p = 0.023). In addition, HDL antioxidant capacity improved gradually from 34.4% at baseline to 42.4% at 4 weeks (p = 0.011), 65.9% at end of treatment EOT (p = 0.002) and remained elevated at 12-week (p = 0.001) after EOT compared to baseline values. Our findings suggest that a shift to a less atherogenic lipid profile may be a possible mechanism associated with CV risk reduction in patients with HCV infection achieving SVR.
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2.
An interferon lambda 4-associated variant in the hepatitis C virus RNA polymerase affects viral replication in infected cells.
Bamford, CGG, McLauchlan, J
The Journal of general virology. 2021;(2)
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Abstract
Host IFNL4 haplotype status contributes to the development of chronic hepatitis C virus (HCV) infection in individuals who are acutely infected with the virus. In silico studies revealed that specific amino acid variants at multiple sites on the HCV polyprotein correlate with functional single-nucleotide polymorphisms (SNPs) in the IFNL4 locus. Thus, SNPs at the IFNL4 locus may select variants that influence virus replication and thereby the outcome of infection. Here, we examine the most significantly IFNL4-associated amino acid variants that lie in the 'lambda (L) 2 loop' of the HCV NS5B RNA polymerase. L2 loop variants were introduced into both sub-genomic replicon and full-length infectious clones of HCV and viral replication was examined in the presence and absence of exogenous IFNλ4. Our data demonstrate that while mutation of the NS5B L2 loop affects replication, individual IFNL4-associated variants have modest but consistent effects on replication in both the presence and absence of IFNλ4. Given the strong genetic association between these variants and IFNL4, these data suggest a nuanced effect of each individual position on viral replication, the combined effect of which might mediate resistance to the effects of IFNλ4.
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Prophylaxis, diagnosis and therapy of infections in patients undergoing high-dose chemotherapy and autologous haematopoietic stem cell transplantation. 2020 update of the recommendations of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO).
Christopeit, M, Schmidt-Hieber, M, Sprute, R, Buchheidt, D, Hentrich, M, Karthaus, M, Penack, O, Ruhnke, M, Weissinger, F, Cornely, OA, et al
Annals of hematology. 2021;(2):321-336
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Abstract
To ensure the safety of high-dose chemotherapy and autologous stem cell transplantation (HDC/ASCT), evidence-based recommendations on infectious complications after HDC/ASCT are given. This guideline not only focuses on patients with haematological malignancies but also addresses the specifics of HDC/ASCT patients with solid tumours or autoimmune disorders. In addition to HBV and HCV, HEV screening is nowadays mandatory prior to ASCT. For patients with HBs antigen and/or anti-HBc antibody positivity, HBV nucleic acid testing is strongly recommended for 6 months after HDC/ASCT or for the duration of a respective maintenance therapy. Prevention of VZV reactivation by vaccination is strongly recommended. Cotrimoxazole for the prevention of Pneumocystis jirovecii is supported. Invasive fungal diseases are less frequent after HDC/ASCT, therefore, primary systemic antifungal prophylaxis is not recommended. Data do not support a benefit of protective room ventilation e.g. HEPA filtration. Thus, AGIHO only supports this technique with marginal strength. Fluoroquinolone prophylaxis is recommended to prevent bacterial infections, although a survival advantage has not been demonstrated.
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Mechanism of zinc ejection by disulfiram in nonstructural protein 5A.
Rehman, AU, Zhen, G, Zhong, B, Ni, D, Li, J, Nasir, A, Gabr, MT, Rafiq, H, Wadood, A, Lu, S, et al
Physical chemistry chemical physics : PCCP. 2021;(21):12204-12215
Abstract
Hepatitis C virus (HCV) is a notorious member of the Flaviviridae family of enveloped, positive-strand RNA viruses. Non-structural protein 5A (NS5A) plays a key role in HCV replication and assembly. NS5A is a multi-domain protein which includes an N-terminal amphipathic membrane anchoring alpha helix, a highly structured domain-1, and two intrinsically disordered domains 2-3. The highly structured domain-1 contains a zinc finger (Zf)-site, and binding of zinc stabilizes the overall structure, while ejection of this zinc from the Zf-site destabilizes the overall structure. Therefore, NS5A is an attractive target for anti-HCV therapy by disulfiram, through ejection of zinc from the Zf-site. However, the zinc ejection mechanism is poorly understood. To disclose this mechanism based on three different states, A-state (NS5A protein), B-state (NS5A + Zn), and C-state (NS5A + Zn + disulfiram), we have performed molecular dynamics (MD) simulation in tandem with DFT calculations in the current study. The MD results indicate that disulfiram triggers Zn ejection from the Zf-site predominantly through altering the overall conformation ensemble. On the other hand, the DFT assessment demonstrates that the Zn adopts a tetrahedral configuration at the Zf-site with four Cys residues, which indicates a stable protein structure morphology. Disulfiram binding induces major conformational changes at the Zf-site, introduces new interactions of Cys39 with disulfiram, and further weakens the interaction of this residue with Zn, causing ejection of zinc from the Zf-site. The proposed mechanism elucidates the therapeutic potential of disulfiram and offers theoretical guidance for the advancement of drug candidates.
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An electrochemical biosensor for direct detection of hepatitis C virus.
Antipchik, M, Korzhikova-Vlakh, E, Polyakov, D, Tarasenko, I, Reut, J, Öpik, A, Syritski, V
Analytical biochemistry. 2021;:114196
Abstract
This paper is aimed at the development of a biosensor for direct detection of Hepatitis C virus (HCV) surface antigen: envelope protein (E2). A recombinant LEL fragment of biological cell receptor CD81 and two short synthetic peptides imitating the fragment of LEL sequence of CD81 (linear and loop-like peptides) capable of specific binding to E2 were tested as molecular recognition elements of the biosensor. For this purpose the selected ligands were immobilized to the surface of a screen-printed electrode utilized as an electrochemical sensor platform. The immobilization parameters such as the ligand concentration and the immobilization time were carefully optimized for each ligand. Differential pulse voltammetry used to evaluate quantitatively binding of E2 to the ligands revealed their similar binding affinity towards E2. Thus, the linear peptide was selected as a less expensive and easily prepared ligand for the HCV biosensor preparation. The resulting HCV biosensor demonstrated selectivity towards E2 in the presence of interfering protein, conalbumin. Moreover, it was found that the prepared biosensor effectively detected E2 bound to hepatitis C virus-mimetic particles (HC VMPs) at LOD value of 2.1∙10-5 mg/mL both in 0.01 M PBS solution (pH 7.4) and in simulated blood plasma.
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Lipid Droplets Accumulation during Hepatitis C Virus Infection in Cell-Culture Varies among Genotype 1-3 Strains and Does Not Correlate with Virus Replication.
Galli, A, Ramirez, S, Bukh, J
Viruses. 2021;(3)
Abstract
Liver steatosis is a common complication of chronic hepatitis C virus (HCV) infection, which can result in accelerated liver fibrosis development, especially in patients infected with genotype 3a. The precise mechanisms of HCV-induced liver steatosis remain unclear, but it is often posited that increased intracellular lipid accumulation is the underlying cause of steatosis. To study experimentally how HCV infection in human liver derived cells by different genotypes and subtypes might affect lipid accumulation, we performed detailed cytofluorimetric and microscopy analyses of intracellular lipid droplets (LDs) in relation to the viral Core and to cell endoplasmic reticulum proteins. Following culture infection with HCV genotype 1a, 2a, 2b, 2c, and 3a strains, we found variable levels of intracellular LDs accumulation, associated to the infecting strain rather than to the specific genotype. Although two genotype 3a strains showed high levels of lipid accumulation, as previously observed, some strains of other genotypes displayed a similar phenotype. Moreover, the analyses of LDs size, number, and shape indicated that the apparent increase in lipid accumulation is due to an increase in the overall number rather than in the size of droplets. Finally, differences in total lipid content across genotypes did not correlate to differences in Core distribution nor Core levels. In conclusion, our study provides a quantitative in-depth analysis of the effect of HCV infection on LDs accumulation in cell-culture.
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Hepatitis C Virus Clearance by Direct-Acting Antivirals Agents Improves Endothelial Dysfunction and Subclinical Atherosclerosis: HEPCAR Study.
Muñoz-Hernández, R, Ampuero, J, Millán, R, Gil-Gómez, A, Rojas, Á, Macher, HC, Gallego-Durán, R, Gato, S, Montero-Vallejo, R, Rico, MC, et al
Clinical and translational gastroenterology. 2020;(8):e00203
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Abstract
INTRODUCTION Hepatitis C virus (HCV) infection has been related to increased cardiovascular (CV) risk. The aim of this study was to analyze the impact of sustained virological response (SVR) on endothelial dysfunction and subclinical atherosclerosis in patients with hepatitis C virus treated with direct-acting antiviral agents. METHODS A total of 114 patients were prospectively recruited and underwent CV risk assessment including (i) endothelial dysfunction determined through laser Doppler flowmetry and (ii) subclinical atherosclerosis, elucidated by the ankle-brachial index (ABI). Atherogenic lipid profile (total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides); markers of oxidative stress (oxidized low-density lipoprotein antibodies [OLAbs]), soluble markers of adhesion (vascular cell adhesion molecule [VCAM], e-selectin, and soluble markers of angiogenesis; and vascular endothelial growth factor, endothelial [EMPs] and platelet [PMPs] apoptotic microparticles, and cell-free DNA [cfDNA]) were measured. All determinations were performed at baseline, 12 weeks (SVR time), and 1 year after treatment. RESULTS In patients with endothelial dysfunction, area of hyperemia improved after virus clearance (P = 0.013) and was related to significant decrease in VCAM, e-selectin (P < 0.001), and cfDNA (P = 0.017) and to increased OLAb levels (P = 0.001). In patients with subclinical atherosclerosis at baseline, a significantly improved ABI was seen after HCV clearance (P < 0.001). Levels of both EMPs and PMPs also decreased after SVR and at follow-up (P = 0.006 and P = 0.002, respectively). DISCUSSION HCV clearance improved not only liver function but also endothelial dysfunction and subclinical atherosclerosis promoted by decrease in levels of VCAM, e-selectin, cfDNA, and PMPs and EMPs.
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Clinicopathologic characteristics of follicular lymphoma in hepatitis C virus-infected patients.
Hosry, J, Miranda, RN, Samaniego, F, Angelidakis, G, Torres, HA
Hematological oncology. 2020;(3):301-308
Abstract
Follicular lymphoma (FL) is the most common subtype of indolent non-Hodgkin lymphoma. It has been hypothesized that chronic hepatitis C virus (HCV) infection stimulates IGH-BCL2 clone proliferation, leading to development of FL. Furthermore, regression of FL after antiviral treatment without chemotherapy has been reported in HCV-infected patients. To clarify the relationship between HCV and FL, we compared the prevalence of IGH-BCL2 translocation and other clinicopathologic characteristics between HCV-infected and HCV-uninfected FL patients and determined the impact of HCV eradication on the oncologic outcomes of HCV-infected FL patients. The study included HCV-infected patients (cases) with FL seen at our institution during 2004-2018. Cases were matched with HCV-uninfected FL patients (controls) according to year of lymphoma diagnosis, sex, and hepatitis B serology. We studied 19 cases and 57 controls. More cases than controls had splenic involvement of FL (26% vs 5%, P = 0.02), higher histologic grade (grade 3 in 56% vs 24%, P = 0.01), absent or weak CD10 expression (42% vs 11%, P = 0.005), and absent BCL2 expression (33% vs 4%, P = 0.004). Compared to controls, cases had a lower rate of detection of IGH-BCL2 translocation (31% vs 68%, P = 0.02). Finally, cases with a sustained virologic response (virologic cure of HCV) had a better 10-year overall survival rate than did cases not treated with antivirals or controls (P = 0.001). In conclusion, HCV-infected patients with FL have unique clinicopathologic characteristics including improved overall survival with HCV eradication. The pathogenesis of FL in HCV-infected patients seems unrelated to antiapoptotic effect of IGH-BCL2 rearrangement.
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Phenotypic analysis of mutations at residue 146 provides insights into the relationship between NS5A hyperphosphorylation and hepatitis C virus genome replication.
Goonawardane, N, Yin, C, Harris, M
The Journal of general virology. 2020;(3):252-264
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Abstract
The hepatitis C virus genotype 2a isolate, JFH-1, exhibits much more efficient genome replication than other isolates. Although basic replication mechanisms must be conserved, this raises the question of whether the regulation of replication might exhibit isolate- and/or genotype-specific characteristics. Exemplifying this, the phenotype of NS5A hyperphosphorylation is genotype-dependent; in genotype 1b a loss of hyperphosphorylation correlates with an enhancement of replication. In contrast, the replication of JFH-1 is not regulated by hyperphosphorylation. We previously identified a novel phosphorylation site in JFH-1 NS5A: S146. A phosphomimetic substitution (S146D) had no effect on replication but correlated with a loss of hyperphosphorylation. In genotype 1b, residue 146 is alanine and we therefore investigated whether the substitution of A146 with a phosphorylatable (S), or phosphomimetic, residue would recapitulate the JFH-1 phenotype, decoupling hyperphosphorylation from replication. This was not the case, as A146D exhibited both a loss of hyperphosphorylation and a reduction in replication, accompanied by a perinuclear restriction of replication complexes, reductions in lipid droplet and PI4P lipid accumulation, and a disruption of NS5A dimerization. In contrast, the S232I culture-adaptive mutation in the low-complexity sequence I (LCSI) also exhibited a loss of hyperphosphorylation, but was associated with an increase in replication. Taken together, these data imply that hyperphosphorylation does not directly regulate replication. In contrast, the loss of hyperphosphorylation is a consequence of perturbing genome replication and NS5A function. Furthermore, we show that mutations in either domain I or LCSI of NS5A can disrupt hyperphosphorylation, demonstrating that multiple parameters influence the phosphorylation status of NS5A.
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Whole Lotta Lipids-from HCV RNA Replication to the Mature Viral Particle.
Bley, H, Schöbel, A, Herker, E
International journal of molecular sciences. 2020;(8)
Abstract
Replication of the hepatitis C virus (HCV) strongly relies on various lipid metabolic processes in different steps of the viral life cycle. In general, HCV changes the cells' lipidomic profile by differentially regulating key pathways of lipid synthesis, remodeling, and utilization. In this review, we sum up the latest data mainly from the past five years, emphasizing the role of lipids in HCV RNA replication, assembly, and egress. In detail, we highlight changes in the fatty acid content as well as alterations of the membrane lipid composition during replication vesicle formation. We address the role of lipid droplets as a lipid provider during replication and as an essential hub for HCV assembly. Finally, we depict different ideas of HCV maturation and egress including lipoprotein association and potential secretory routes.