The disproportionate imbalance between the systemic manifestation of reactive oxygen species and body’s ability to detoxify the reactive intermediates is referred to as oxidative stress. Several biological processes as well as infectious agents, physiological or environmental stress, and perturbed antioxidant response can promote oxidative stress. Oxidative stress usually happens when cells are exposed to more electrically charged reactive oxygen species (ROS) such as H2O2 or O2-. The cells’ ability to handle such pro-oxidant species is impeded by viral infections particularly within liver that plays an important role in metabolism and detoxification of harmful substances. During liver diseases (such as hepatocellular or cholestatic problems), the produced ROS are involved in transcriptional activation of a large number of cytokines and growth factors, and continued production of ROS and Reactive Nitrogen Species (RNS) feed into the vicious cycle. Many human viruses like HCV are evolved to manipulate this delicate pro- and antioxidant balance; thus generating the sustainable oxidative stress that not only causes hepatic damage but also stimulates the processes to reduce treatment of damage. In this review article, the oxidant and antioxidant pathways that are perturbed by HCV genes are discussed. In the first line of risk, the pathways of lipid metabolism present a clear danger in accumulation of viral induced ROS. Viral infection leads to decrease in cellular concentrations of glutathione (GSH) resulting in oxidation of important components of cells such as proteins, DNA and lipids as well as double strand breakage of DNA. These disorders have the tendency to lead the cells toward cirrhosis and hepatocellular carcinoma in adults due to constant insult. We have highlighted the importance of such pathways and revealed differences in the extent of oxidative stress caused by HCV infection.
Hepatitis B virus (HBV) infections play an important role in the development of hepatocellular carcinoma (HCC). HBV X protein (HBx) is a multifunctional protein that can modulate various cellular processes and plays a crucial role in the pathogenesis of HCC. HBx is known to interact with DNA helicase components of TFIIH, a basal transcriptional factor and an integral component of DNA excision repair.
Chronic Hepatitis C virus has the potential of inducing insulin resistance and type 2 Diabetes Mellitus in vitro as well as in vivo . Structural and non-structural proteins of HCV modulate cellular gene expression in such a way that insulin signaling is hampered, concomitantly leads toward diabetes mellitus. A number of mechanisms have been proposed in regard to the HCV induced insulin resistance involving the upregulation of Inflammatory cytokine TNF-α, hypophosphorylation of IRS-1 and IRS-2, phosphorylation of Akt, up-regulation of gluconeogenic genes, accumulation of lipids and targeting lipid storage organelles. This review provides an insight of molecular mechanisms by which HCV structural and non-structural proteins can induce insulin resistance.
Hepatitis C virus (HCV) is a major health problem in developing countries including Pakistan. Chronic HCV infection results in progressive liver disease including fibrosis, cirrhosis, insulin resistance and eventually hepatocellular carcinoma (HCC). Ionotrophic purinergic (P2X) receptors are identified to involve in a spectrum of physiological and pathophysiological processes. However, the role of P2X receptors in HCV liver associated diseases still remains to be investigated. The current study was designed to identify the presence of P2X receptors in human liver cells. Furthermore, it investigates the response of P2X receptors towards HCV structural proteins (E1E2). To determine that how many isoforms of P2X receptors are expressed in human liver cells, human hepatoma cell line (Huh-7) was used. Transcripts (mRNA) of five different isoforms of P2X receptors were identified in Huh-7 cells. To examine the gene expression of identified isoforms of P2X receptors in presence of HCV structural proteins E1E2, Huh-7/E1E2 cell line (stably expressing HCV structural proteins E1E2) was used. The results showed significant increase (6.2 fold) in gene expression of P2X4 receptors in Huh-7/E1E2 cells as compared to control Huh-7 cells. The findings of present study confirmed the presence of transcripts of five different isoforms of P2X receptors in human liver cells and suggest that P2X4 receptors could be represented an important component of the purinergic signaling complex in HCV induced liver pathogenesis.
On 22 Feb 2013, the Polio Monitoring Cell of Pakistan announced that the 2012-2013 polio campaign ended, and that 1.6 million children could not be vaccinated due to security concerns in several regions where polio workers had been killed. Those who could not be vaccinated included 50,000 children from the Federally Administrated Tribal Area (FATA), 150,000 form Khyber Pakhtoon Khao, 400,000 from a Quetta, 400,000 from Karachi, and a small number from the Rawalpindi District. These statistics are worrying, as several districts in the large metropolitan cities of Karachi and Quetta were also excluded. The fear of advanced medicine, ideas, or complex devices is a new phenomenon in many conservative and poor countries such as Pakistan, Afghanistan, Sudan, and Somalia. To safeguard the safety of the rest of the world, the failure in the implementation of WHO guidelines for vaccination must be regulated by the UN. There are a number of reasons for the phobias surrounding vaccination, but as technology continues to evolve at such a rapid rate, those with self-determined ideologies cannot cope with such advances. They become vocal to gain popularity and prevent the use of these technologies and medicine by creating and spreading rumors and propaganda of expediency. The struggle to vaccinate children is not easily understood by anyone living in the developed world. The irrational fear of vaccines and the lack of vaccination pose a serious global health risk and must be curbed through a wide variety of pro-vaccination media and religious campaigns.