Identification of ionotrophic purinergic receptors in Huh-7 cells and their response towards structural proteins of HCV genotype 3a

Hepatitis C virus (HCV) is blood borne pathogen which is a major cause of different liver associated diseases varying from an asymptomatic condition to hepatocellular carcinoma (HCC) [1-5]. It is estimated that 3.3% of the population globally and 10% of the Pakistani population is chronically infected with HCV [6,7]). The genome of HCV is 9.6-kb-long, which predetermines a polyprotein of about 3,010 amino acids and encodes 3 structural (core, E1, E2, p7) and 7 nonstructural (P7, NS2, NS3, NS4A, NS4B, NS5A, NS5B) proteins [3,8-10]. These viral proteins not only function in viral replication but also dysregulate a variety of cellular functions [1,11,12].During their synthesis, HCV envelope proteins E1E2 are inserted into the membranes of endoplasmic reticulum (ER). Immunolocalization studies have revealed the presence of E1E2 in the ER [13]. Liver mitochondria from transgenic mice expressing the HCV proteins core, E1 and E2, showed a significant decrease in mitochondrial glutathione and reduced activity and increased reactive oxidative species (ROS) production from mitochondrial electron transport complex I. These results suggest that changes in mitochondrial glutathione and complex I inhibition induced by core, E1 and E2 is an important cause of the oxidative stress seen in chronic hepatitis C [14]. Therefore, HCV envelope glycoproteins (E1E2) are a good candidate to study the HCV induced ROS, very well known reported to play a key role in the development of hepatic and extrahepatic complications in HCV chronic infection [15]. The major HCV genotype in Pakistan is 3a, with a strong association between chronic HCV infection and HCC in Pakistani population correlated with genotype 3a [6,16,17].Significant attention is presently being drawn towards the HCV modulated molecular pathways that lead to liver pathogenesis [18,19]. Although many of the signals that regulate induction of liver pathogenesis have been defined, however, the second messengers by whom these signals