Ishtiaq Qadri

Oxidative stress and hepatitis C virus

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.

Biomarkers for virus-induced hepatocellular carcinoma (HCC)

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and is advanced by severe viral hepatitis B or C (HBV or HCV) as well as alcoholic liver disease. Many patients with early disease are asymptomatic therefore HCC is frequently diagnosed late requiring costly surgical resection or transplantation. The available non-invasive detections systems are based on the clinical utility of alpha fetoprotein (AFP) measurement, together with ultrasound and other more sensitive imaging techniques. The hallmark of liver disease and its propensity to develop into fully blown HCC is depended on several factors including the host genetic make-up and immune responses. While common symptoms involve diarrhea, bone pain, dyspnea, intraperitoneal bleeding, obstructive jaundice, and paraneoplastic syndrome, the evolution of cell and immune markers is important to understand viral induced liver cancers in humans. The circulating miRNA, cell and immune based HCC biomarkers are imperative candidates to successfully develop strategies to restrain liver injury. The current molecular genetics and proteomic analysis have lead to the identification of number of key biomarkers for HCC for earlier diagnosis and more effective treatment of HCC patients. In this review article, we provide latest updates on the biomarkers of HBV or HCV-associated HCC and their co-evolutionary relationship with liver cancer.

Acoustic and hybrid 3D-printed electrochemical biosensors for the real-time immunodetection of liver cancer cells (HepG2)

This study presents an efficient acoustic and hybrid three-dimensional (3D)-printed electrochemical biosensors for the detection of liver cancer cells. The biosensors function by recognizing the highly expressed tumor marker CD133, which is located on the surface of liver cancer cells. Detection was achieved by recrystallizing a recombinant S-layer fusion protein (rSbpA/ZZ) on the surface of the sensors. The fused ZZ-domain enables immobilization of the anti-CD133 antibody in a defined manner. These highly accessible anti-CD133 antibodies were employed as a sensing layer, thereby enabling the efficient detection of liver cancer cells (HepG2). The recognition of HepG2 cells was investigated in situ using a quartz crystal microbalance with dissipation monitoring (QCM-D), which enabled the label-free, real-time detection of living cells on the modified sensor surface under controlled conditions. Furthermore, the hybrid 3D additive printing strategy for biosensors facilitates both rapid development and small-scale manufacturing. The hybrid strategy of combining 3D-printed parts and more traditionally fabricated parts enables the use of optimal materials: a ceramic substrate with noble metals for the sensing element and 3D-printed capillary channels to guide and constrain the clinical sample. Cyclic voltammetry (CV) measurements confirmed the efficiency of the fabricated sensors. Most importantly, these sensors offer low-cost and disposable detection platforms for real-world applications. Thus, as demonstrated in this study, both fabricated acoustic and electrochemical sensing platforms can detect cancer cells and therefore may have further potential in other clinical applications and drug-screening studies.

Docking Studies of Pakistani HCV NS3 Helicase: A Possible Antiviral Drug Target

The nonstructural protein 3 (NS3) of hepatitis C virus (HCV) helicase is believed to be essential for viral replication and has become an attractive target for the development of antiviral drugs. The study of helicase is useful for elucidating its involvement in positive sense single-stranded RNA virus replication and to serve as templates for the design of novel antiviral drugs. In recent years, several models have been proposed on the conformational change leading to protein movement and RNA unwinding. Some compounds have been recently reported to inhibit the helicase and these include small molecules, RNA aptamers and antibodies. The current study is designed to help gain insights for the consideration of potential inhibitors for Pakistani HCV NS3 helicase protein. We have cloned, expressed and purified HCV NS3 helicase from Pakistani HCV serum samples and determined its 3D structure and employed it further in computational docking analysis to identify inhibitors against HCV genotype 3a (GT3a),including six antiviral key molecules such as quercetin, beta-carotene, resveratrol, catechins, lycopene and lutein. The conformation obtained after docking showed good hydrogen bond (HBond) interactions with best docking energy for quercetin and catechins followed by resveratrol and lutein. These anti-helicase key molecules will offer an alternative attraction to target the viral helicase, due to the current limitation with the interferon resistance treatment and presences of high rate of resistance in anti-protease inhibitor classes.

Battle against poliovirus in Pakistan

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.

Association of HCV mutated proteins and host SNPs in the development of hepatocellular carcinoma

Hepatitis C virus plays a significant role in the development of hepatocellular carcinoma (HCC) globally. The pathogenic mechanisms of hepatocellular carcinoma with HCV infection are generally linked with inflammation, cytokines, fibrosis, cellular signaling pathways, and liver cell proliferation modulating pathways. HCV encoded proteins (Core, NS3, NS4, NS5A) interact with a broad range of hepatocytes derived factors to modulate an array of activities such as cell signaling, DNA repair, transcription and translational regulation, cell propagation, apoptosis, membrane topology. These four viral proteins are also implicated to show a strong conversion potential in tissue culture. Furthermore, Core and NS5A also trigger the accretion of the β-catenin pathway as a common target to contribute viral induced transformation. There is a strong association between HCV variants within Core, NS4, and NS5A and host single nucleotide polymorphisms (SNPs) with the HCC pathogenesis. Identification of such viral mutants and host SNPs is very critical to determine the risk of HCC and response to antiviral therapy. In this review, we highlight the association of key variants, mutated proteins, and host SNPs in development of HCV induced HCC. How such viral mutants may modulate the interaction with cellular host machinery is also discussed.

Upregulated hepatic expression of mitochondrial PEPCK triggers initial gluconeogenic reactions in the HCV-3 patients.

OBJECTIVE To identify the differential expression of candidate gluconeogenic genes which may initiate hepatitis C virus (HCV) related metabolic disorder during early stages of disease. METHODS Patients of diverse age and sex, with positive HCV genotype 3 (HCV-3) RNA in serum and with no history of other related infections, co-infections, alcoholism, diabetes or chemotherapeutic treatments were considered for this study. Semi-quantitative reverse transcriptase PCR analysis and quantitative fold change analysis of the fresh liver biopsies of eight chronically infected HCV-3 patients and six healthy individuals were evaluated for three potential biomarkers involved in glucose homeostasis induction, namely mitochondrial phosphoenolpyruvate carboxykinase 2 (PCK2), glucose-6-phosphatase catalytic subunit (G6PC) and associated forkhead box protein 01 (FOXO1). RESULTS Symptomatic evaluation, clinical history and blood test were conducted according to general disease prognosis procedures and reported here. Significantly upregulated expression of PCK2 independent of age, sex and viral infectivity levels in all HCV patients was observed, whereas no significant changes in the expression of G6PC and FOXO1 were found. CONCLUSIONS PCK2 triggers initial gluconeogenic reactions which ultimately result in the accumulation of glycogen in the liver hepatocytes. We therefore suggest that the overproduction of PCK2 has important physiological role in the onset of metabolic disorder in the HCV-3 patients.

Consequence of HIV and HCV co-infection on host immune response, persistence and current treatment options

Hepatitis C virus (HCV) is a common opportunistic pathogen especially among Human immunodeficiency virus (HIV) infected patients. Due to incongruous studies, the pathological effect of HCV on HIV induced disease are still not fully understood. While some studies have showed no effect of HCV on HIV infection, others reported a defined role of HCV in aggravating the rates of AIDS-related illnesses and mortality. The explanation of such variances may be due to the host immune response, viral genotypes, sub-type and quasi-species distribution. The factors that complicate the management of HIV/HCV patients are: (1) reduced HCV antibody production, (2) drug interactions, (3) liver disease and (4) different epidemiologic characteristics. However, it is abundantly clear that the morbidity and mortality caused by HCV have increased since the introduction of highly active antiretroviral therapy (HAART) against HIV. In this review, the consequence of HIV/HCV co-infection on host immune response, viral replication, disease progression, mortality and morbidity, viral load, persistence and current treatment options have been discussed. Based on the clinical studies, it is necessary to evaluate the effect of HCV therapy on HIV progression and to provide a fully active HCV treatment for patients receiving HIV treatment. In conclusion, it is recommended to provide fully active HAART therapy in combination with a known HCV therapy.

The dual specificity role of transcription factor FOXO in type 2-diabetes and cancer

The FOXO (Forkhead box O) transcription factors are implicated in several signaling pathways and play a vital role in various cellular and physiological processes include for instance, ROS (reactive oxygen species) response, cell proliferation, regulation of programmed cell death, longevity, metabolism and cancer and regulation of cell cycle. In humans, the four FOXO family members are responsible for resemblance in their structure, regulation and functions. FOXO1 gene is highly expressed in adipose tissues and it affects the regulation of glycogenolysis and gluconeogenesis through insulin signaling. The gene of FOXO3 is highly expressed in the kidney, heart, spleen and brain and is characterized as diverse forkhead DNA-binding domain of transcription factors. The FOXO3 is a tumor suppressor gene and found to interact with p53, the trigger for apoptosis through BCl2 family genes and a regulator of Notch signaling pathway for the self-renewal of stem cells. Therefore, FOXOs remains to be a fascinating and potential target to acquire novel therapeutic approaches to cure cancer. This review will provide a comprehensive overview about the biology of FOXO proteins, which can be utilized for developing current therapeutic approaches to treat cancer.