Browsing by Author "Vikas Pareek"

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COVID-19 Mechanisms in the Human Body—What We Know So Far
(Frontiers Media S.A., 2021) Ashutosh Kumar; Ravi K. Narayan; Pranav Prasoon; Chiman Kumari; Gurjot Kaur; Santosh Kumar; Maheswari Kulandhasamy; Kishore Sesham; Vikas Pareek; Muneeb A. Faiq; Sada N. Pandey; Himanshu N. Singh; Kamla Kant; Prakash S. Shekhawat; Khursheed Raza; Sujeet Kumar
More than one and a half years have elapsed since the commencement of the coronavirus disease 2019 (COVID-19) pandemic, and the world is struggling to contain it. Being caused by a previously unknown virus, in the initial period, there had been an extreme paucity of knowledge about the disease mechanisms, which hampered preventive and therapeutic measures against COVID-19. In an endeavor to understand the pathogenic mechanisms, extensive experimental studies have been conducted across the globe involving cell culture-based experiments, human tissue organoids, and animal models, targeted to various aspects of the disease, viz., viral properties, tissue tropism and organ-specific pathogenesis, involvement of physiological systems, and the human immune response against the infection. The vastly accumulated scientific knowledge on all aspects of COVID-19 has currently changed the scenario from great despair to hope. Even though spectacular progress has been made in all of these aspects, multiple knowledge gaps are remaining that need to be addressed in future studies. Moreover, multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants have emerged across the globe since the onset of the first COVID-19 wave, with seemingly greater transmissibility/virulence and immune escape capabilities than the wild-type strain. In this review, we narrate the progress made since the commencement of the pandemic regarding the knowledge on COVID-19 mechanisms in the human body, including virus–host interactions, pulmonary and other systemic manifestations, immunological dysregulations, complications, host-specific vulnerability, and long-term health consequences in the survivors. Additionally, we provide a brief review of the current evidence explaining molecular mechanisms imparting greater transmissibility and virulence and immune escape capabilities to the emerging SARS-CoV-2 variants. Copyright © 2021 Kumar, Narayan, Prasoon, Kumari, Kaur, Kumar, Kulandhasamy, Sesham, Pareek, Faiq, Pandey, Singh, Kant, Shekhawat, Raza and Kumar.
Predicting susceptibility for SARS-CoV-2 infection in domestic and wildlife animals using ACE2 protein sequence homology
(Wiley-Liss Inc., 2021) Ashutosh Kumar; Sada N. Pandey; Vikas Pareek; Ravi K. Narayan; Muneeb A. Faiq; Chiman Kumari
The article is presenting a bioinformatics based method predicting susceptibility for SARS-CoV-2 infection in domestic and wildlife animals. Recently, there were reports of cats and ferrets, dogs, minks, golden hamster, rhesus monkeys, tigers, and lions testing for SARS-CoV-2 RNA which indicated for the possible interspecies viral transmission. Our method successfully predicted the susceptibility of these animals for contracting SARS-CoV-2 infection. This method can be used as a screening tool for guiding viral RNA testing for domestic and wildlife animals at risk of getting COVID-19. We provide a list of the animals at risk of developing COVID-19 based on the susceptibility score. © 2020 Wiley Periodicals LLC
Relevance of SARS-CoV-2 related factors ACE2 and TMPRSS2 expressions in gastrointestinal tissue with pathogenesis of digestive symptoms, diabetes-associated mortality, and disease recurrence in COVID-19 patients
(Churchill Livingstone, 2020) Ashutosh Kumar; Muneeb A. Faiq; Vikas Pareek; Khursheed Raza; Ravi K. Narayan; Pranav Prasoon; Pavan Kumar; Maheswari Kulandhasamy; Chiman Kumari; Kamla Kant; Himanshu N. Singh; Rizwana Qadri; Sada N. Pandey; Santosh Kumar
COVID-19 is caused by a new strain of coronavirus called SARS-coronavirus-2 (SARS-CoV-2), which is a positive sense single strand RNA virus. In humans, it binds to angiotensin converting enzyme 2 (ACE2) with the help a structural protein on its surface called the S-spike. Further, cleavage of the viral spike protein (S) by the proteases like transmembrane serine protease 2 (TMPRSS2) or Cathepsin L (CTSL) is essential to effectuate host cell membrane fusion and virus infectivity. COVID-19 poses intriguing issues with imperative relevance to clinicians. The pathogenesis of GI symptoms, diabetes-associated mortality, and disease recurrence in COVID-19 are of particular relevance because they cannot be sufficiently explained from the existing knowledge of the viral diseases. Tissue specific variations of SARS-CoV-2 cell entry related receptors expression in healthy individuals can help in understanding the pathophysiological basis the aforementioned collection of symptoms. ACE2 mediated dysregulation of sodium dependent glucose transporter (SGLT1 or SLC5A1) in the intestinal epithelium also links it to the pathogenesis of diabetes mellitus which can be a possible reason for the associated mortality in COVID-19 patients with diabetes. High expression of ACE2 in mucosal cells of the intestine and GB make these organs potential sites for the virus entry and replication. Continued replication of the virus at these ACE2 enriched sites may be a basis for the disease recurrence reported in some, thought to be cured, patients. Based on the human tissue specific distribution of SARS-CoV-2 cell entry factors ACE2 and TMPRSS2 and other supportive evidence from the literature, we hypothesize that SARS-CoV-2 host cell entry receptor—ACE2 based mechanism in GI tissue may be involved in COVID-19 (i) in the pathogenesis of digestive symptoms, (ii) in increased diabetic complications, (iii) in disease recurrence. © 2020 Elsevier Ltd