Integrative Multiomics and Regulatory Network Analyses Uncovers the Role of OAS3, TRAFD1, miR-222-3p, and miR-125b-5p in Hepatitis E Virus Infection.

The hepatitis E virus (HEV) is a long-ignored virus that has spread globally with time. It ranked 6th among the top risk-ranking viruses with high zoonotic spillover potential; thus, considering its viral threats is a pressing priority. The molecular pathophysiology of HEV infection or the underlying cause is limited. Therefore, we incorporated an unbiased, systematic methodology to get insights into the biological heterogeneity associated with the HEV. Our study fetched 93 and 2016 differentially expressed genes (DEGs) from chronic HEV (CHEV) infection in kidney-transplant patients, followed by hub module selection from a weighted gene co-expression network (WGCN). Most of the hub genes identified in this study were associated with interferon (IFN) signaling pathways. Amongst the genes induced by IFNs, the 2'-5'-oligoadenylate synthase 3 (OAS3) protein was upregulated. Protein-protein interaction (PPI) modular, functional enrichment, and feed-forward loop (FFL) analyses led to the identification of two key miRNAs, i.e., miR-222-3p and miR-125b-5p, which showed a strong association with the OAS3 gene and TRAF-type zinc finger domain containing 1 (TRAFD1) transcription factor (TF) based on essential centrality measures. Further experimental studies are required to substantiate the significance of these FFL-associated genes and miRNAs with their respective functions in CHEV. To our knowledge, it is the first time that miR-222-3p has been described as a reference miRNA for use in CHEV sample analyses. In conclusion, our study has enlightened a few budding targets of HEV, which might help us understand the cellular and molecular pathways dysregulated in HEV through various factors. Thus, providing a novel insight into its pathophysiology and progression dynamics.

Innate Immune Response and Inflammasome Activation During SARS-CoV-2 Infection.

The novel coronavirus SARS-CoV-2, responsible for the COVID-19 outbreak, has become a pandemic threatening millions of lives worldwide. Recently, several vaccine candidates and drugs have shown promising effects in preventing or treating COVID-19, but due to the development of mutant strains through rapid viral evolution, urgent investigations are warranted in order to develop preventive measures and further improve current vaccine candidates. Positive-sense-single-stranded RNA viruses comprise many (re)emerging human pathogens that pose a public health problem. Our innate immune system and, in particular, the interferon response form an important first line of defense against these viruses. Flexibility in the genome aids the virus to develop multiple strategies to evade the innate immune response and efficiently promotes their replication and infective capacity. This review will focus on the innate immune response to SARS-CoV-2 infection and the virus' evasion of the innate immune system by escaping recognition or inhibiting the production of an antiviral state. Since interferons have been implicated in inflammatory diseases and immunopathology along with their protective role in infection, antagonizing the immune response may have an ambiguous effect on the clinical outcome of the viral disease. This pathology is characterized by intense, rapid stimulation of the innate immune response that triggers activation of the Nod-like receptor family, pyrin-domain-containing 3 (NLRP3) inflammasome pathway, and release of its products including the pro-inflammatory cytokines IL-6, IL-18, and IL-1ß. This predictive view may aid in designing an immune intervention or preventive vaccine for COVID-19 in the near future.

Emergence of deadly severe acute respiratory syndrome coronavirus-2 during 2019-2020.

Wuhan, the city in Hubei province in China is in the focus of global community due to the outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), formerly known as 2019-nCoV. The virus emerged in humans from Wuhan seafood market probably via zoonotic transmission. Within a few days the virus spread its tentacles rapidly to neighboring cities in China and to different geographical regions through travelers and to some extent by human to human transmission leading to significant disease burden globally. More than 2,00,000 people (including more than 8000 deaths) have been infected with this respiratory illness across 167 countries and territories worldwide leading to a pandemic. The present review provides an outline about emergence and spread of SARS-CoV-2 from Wuhan, China in 2019-2020. We have also provided information about the classification, genome, proteins, clinical presentation of COVID-19, type of clinical specimens to be collected and diagnostic methods adopted to identify the respiratory illness. In addition we have also provided information about transmission dynamics, prevention measures and treatment options that are available at the present. Subsequently, we have given a comprehensive overview of the spread of this infection from China to the other parts of the globe. Management of the ongoing outbreak of SARS-CoV-2 encompassing surveillance, clinical, immunological, genetic and evolutionary investigations are likely to provide the desired results. Joint efforts of global scientific community are needed at this hour in terms of enhancement of research on development of accurate diagnostics, antiviral therapeutics and finally into formation of an effective vaccine against the emerging novel coronavirus.