Hepatitis C virus NS5A and core proteins induce oxidative stress-mediated calcium signalling alterations in hepatocytes

• Published in: Journal of hepatology Vol. 50; no. 5; pp. 872 - 882
• Main Authors: Dionisio, Natalia, Garcia-Mediavilla, Maria V, Sanchez-Campos, Sonia, Majano, Pedro L, Benedicto, Ignacio, Rosado, Juan A, Salido, Gines M, Gonzalez-Gallego, Javier
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01-05-2009; Elsevier
• Subjects: Actin reorganization; Actins - metabolism; Antioxidants - pharmacology; Biological and medical sciences; Calcium - metabolism; Calcium Signaling - drug effects; Calcium Signaling - physiology; Calcium signalling; Calcium-Binding Proteins - pharmacology; Cell Line; Cell Survival - physiology; Core protein; Cysteine Proteinase Inhibitors - pharmacology; Cytokines - metabolism; Gastroenterology and Hepatology; Gastroenterology. Liver. Pancreas. Abdomen; Hepacivirus - physiology; Hepatitis C - drug therapy; Hepatitis C - metabolism; Hepatitis C virus; Hepatocytes - cytology; Hepatocytes - drug effects; Hepatocytes - physiology; Homeostasis - drug effects; Homeostasis - physiology; Humans; Medical sciences; NS5A protein; Oxidative Stress - drug effects; Oxidative Stress - physiology; Quercetin; Quercetin - pharmacology; Reactive Nitrogen Species - metabolism; Reactive Oxygen Species - metabolism; Viral Core Proteins - physiology; Viral Nonstructural Proteins - physiology; Virus Replication - drug effects; Virus Replication - physiology; NS5A protein; Hepes-buffered saline; CHL; store-operated calcium entry; ROS/RNS; human interferon-alpha2b; sarcoendoplasmic reticulum Ca 2+-ATPase; Calcium signalling; Chang liver cells; HBS; hepatitis C virus; SOCE; Actin reorganization; 2′,7′-dichlorodihydrofluorescein diacetate; plasma membrane Ca 2+-ATPase; SERCA; ER; IFN-alpha; reactive oxygen and nitrogen species; DCFH-DA; TG; Core protein; Quercetin; HCV; thapsigargin; endoplasmic reticulum; PMCA; Hepatitis C virus; Oxidative stress; Calcium; Signalling; Inorganic element; Flavonoid; Protein; Virus; Polyphenol; Hepatocyte; Actin; Gastroenterology; Phenols; Flaviviridae; Hepacivirus
• ISSN: 0168-8278; 1600-0641
• DOI: 10.1016/j.jhep.2008.12.026

Background/Aims The hepatitis C virus (HCV) structural core and non-structural NS5A proteins induce in liver cells a series of intracellular events, including elevation of reactive oxygen and nitrogen species (ROS/RNS). Since oxidative stress is associated to altered intracellular Ca2+ homeostasis, we aimed to investigate the effect of these proteins on Ca2+ mobilization in human hepatocyte-derived transfected cells, and the protective effect of quercetin treatment. Methods Ca2+ mobilization and actin reorganization were determined by spectrofluorimetry. Production of ROS/RNS was determined by flow cytometry. Results Cells transfected with NS5A and core proteins showed enhanced ROS/RNS production and resting cytosolic Ca2+ concentration, and reduced Ca2+ concentration into the stores. Phenylephrine-evoked Ca2+ release, Ca2+ entry and extrusion by the plasma membrane Ca2+ -ATPase were significantly reduced in transfected cells. Similar effects were observed in cytokine-activated cells. Phenylephrine-evoked actin reorganization was reduced in the presence of core and NS5A proteins. These effects were significantly prevented by quercetin. Altered Ca2+ mobilization and increased calpain activation were observed in replicon-containing cells. Conclusions NS5A and core proteins induce oxidative stress-mediated Ca2+ homeostasis alterations in human hepatocyte-derived cells, which might underlie the effects of both proteins in the pathogenesis of liver disorders associated to HCV infection.