Life Sciences

<p>Shiv Nadar University is a comprehensive, multidisciplinary, research-focused, and student-centric University offering a full range of academic programs at the undergraduate, postgraduate and doctoral level. With state-of-the-art infrastructure, the University comprises of academic wings, sophisticated labs, international standard sports facilities, amphitheaters, auditorium, conference rooms and smart classrooms. The University&rsquo;s goal is to become internationally recognized for the quality of its research and creative endeavors and their applicability to improving quality of life, generating new insights and expanding the boundaries of human knowledge creativity. Committed to excellence in teaching, research and service, the University aims to serve the higher education needs of India and the world beyond.</p>

Shiv Nadar University

Hepatitis E virus (HEV) has emerged as a global health concern during the last decade. In spite of a high mortality rate in pregnant women with fulminant hepatitis, no antiviral drugs or licensed vaccine is available in India. HEV-protease is a pivotal enzyme responsible for ORF1 polyprotein processing leading to cleavage of the non-structural enzymes involved in virus replication. HEV-protease region encoding 432–592 amino acids of Genotype-1 was amplified, expressed in Sf21 cells and purified in its native form. The recombinant enzyme was biochemically characterized using SDS-PAGE, Western blotting and Immunofluorescence. The enzyme activity and the inhibition studies were conducted using Zymography, FTC-casein based protease assay and ORF1 polyprotein digestion. To conduct ORF1 digestion assay, the polyprotein, natural substrate of HEV-protease, was expressed in E. coli and purified. Cleavage of 186 kDa ORF1 polyprotein by the recombinant HEV-protease lead to appearance of non-structural proteins viz. Methyltransferase, Protease, Helicase and RNA dependent RNA polymerase which were confirmed through immunoblotting using antibodies generated against specific epitopes of the enzymes. FTC-casein substrate was used for kinetic studies to determine Km and Vmax of the enzyme and also the effect of different metal ions and other protease inhibitors. A 95\% inhibition was observed with E-64 which was validated through in silico analysis. The correlation coefficient between inhibition and docking score of Inhibitors was found to have a significant value of r2 = 0.75. The predicted 3D model showed two domain architecture structures similar to Papain like cysteine protease though they differed in arrangements of alpha helices and beta sheets. Hence, we propose that HEV-protease has characteristics of “Papain-like cysteine protease,” as determined through structural homology, active site residues and class-specific inhibition. However, conclusive nature of the enzyme remains to be established. © Copyright © 2020 Saraswat, Chaudhary and Sehgal.

(SoNS) School of Natural Sciences

Fulltext

Frontiers in Cellular and Infection Microbiology

Hepatitis E Virus Cysteine Protease Has Papain Like Properties Validated by in silico Modeling and Cell-Free Inhibition Assays

Scientific Reports

Publisher Correction: Design and efficient synthesis of pyrazoline and isoxazole bridged indole C-glycoside hybrids as potential anticancer agents (Scientific Reports, (2020), 10, 1, (6660), 10.1038/s41598-020-63377-x)

Inflammation is an immune response to protect against various types of infections. When unchecked, acute inflammation can be life-threatening, as seen with the current coronavirus pandemic. Strong oxidants, such as peroxynitrite produced by immune cells, are major mediators of the inflammation-associated pathogenesis. Cellular thiols play important roles in mitigating inflammation-associated macromolecular damage including DNA. Herein, we have demonstrated a role of glutathione (GSH) and other thiols in neutralizing the effect of peroxynitrite-mediated DNA damage through stable GSH-DNA adduct formation. Our observation supports the use of thiol supplements as a potential therapeutic strategy against severe COVID-19 cases and a Phase II (NCT04374461) open-label clinical trial launched in early May 2020 by the Memorial Sloan Kettering Cancer Center. © 2020 American Chemical Society.

Chemical Research in Toxicology

Protective Role of Glutathione against Peroxynitrite-Mediated DNA Damage during Acute Inflammation

The development of direct-acting antivirals (DAAs) has revolutionized the state-of-the art treatment of HCV infections, with sustained virologic response rates above 90\%. However, viral variants harboring substitutions referred to as resistance-associated substitutions (RASs) may be present in baseline levels and confer resistance to DAAs, thereby posing a major challenge for HCV treatment. HCV replicons have been the primary tools for discovering and evaluating the inhibitory activity of DAAs against viral replication. Interest in replicon systems has further grown as they have become indispensable for discovering genotype-specific and cross-genotype RASs. Here, we review functional replicon systems for HCV, how these replicon systems have contributed to the development of DAAs, and the characteristics and distribution of RASs for DAAs. © Copyright © 2020 Khan, Soni and Veerapu.

HCV Replicon Systems: Workhorses of Drug Discovery and Resistance

Sphingosine-1-phosphate (S1P), a bioactive lipid mediator is involved in an array of biological processes and linked to pathological manifestations. Erythrocyte is known as the major reservoir for S1P as they lack S1P-degrading enzymes (S1P lyase and S1P phosphohydrolase) and harbor sphingosine kinase-1 (SphK-1) essential for sphingosine conversion to S1P. Reduced S1P concentration in serum was correlated with disease severity in patients with Plasmodium falciparum and Plasmodium vivax infections. Herein, we aimed to identify the underlying mechanism and contribution of host erythrocytes toward depleted S1P levels in Plasmodium-infected patients vs. healthy individuals. The level and activity of SphK-1 were measured in vitro in both uninfected and cultured P. falciparum-infected erythrocytes. Infected erythrocytes demonstrated a significant decrease in SphK-1 level in a time-dependent manner. We found that 10–42 h post invasion (hpi), SphK1 level was predominantly reduced to ∼50\% in rings, trophozoites, and schizonts compared to uninfected erythrocytes. We next analyzed the phosphorylation status of SphK-1, a modification responsible for its activity and S1P production, in both uninfected control and Plasmodium-infected erythrocytes. Almost ∼50\% decrease in phosphorylation of SphK-1 was observed that could be corroborated with significant reduction in the production and release of S1P in infected erythrocytes. Serum S1P levels were studied in parallel in P. falciparum (N = 15), P. vivax (N = 36)-infected patients, and healthy controls (N = 6). The findings revealed that S1P concentration was significantly depleted in uncomplicated malaria cases and was found to be lowest in complicated malaria and thrombocytopenia in both P. falciparum and P. vivax-infected groups (∗∗p &lt; 0.01). The lower serum S1P level could be correlated with the reduced platelet count defining the role of S1P level in platelet formation. In conclusion, erythrocyte SphK-1 and S1P levels were studied in Plasmodium-infected individuals and erythrocytes that helped in characterizing the complications associated with malaria and thrombocytopenia, providing insights into the contribution of host erythrocyte biology in malaria pathogenesis. Finally, this study proposes the use of S1P and its analog as a novel adjunct therapy for malaria complications. © Copyright © 2020 Sah, Pati, Saini, Boopathi, Kochar, Kochar, Das and Singh.

World University root node

Frontiers in Cell and Developmental Biology

Reduction of Sphingosine Kinase 1 Phosphorylation and Activity in Plasmodium-Infected Erythrocytes

Here, we report the toxic effects of various imidazolium-based ionic liquids (ILs) with varying hydrocarbon chain lengths, on different human cell lines. Multiple biological assays have shown that the ILs with long hydrocarbon chains have stronger adverse effect especially on human liver cancer cells (Huh-7.5 cells). Further, our study has confirmed that the ILs induce necrosis dependent cell death and that it is related to cell membrane damage. To understand the molecular mechanism of such an effect, the cellular membranes were mimicked as lipid monolayers formed at the air-water interface and then as lipid bilayer vesicles. The pressure area-isotherms measured from the monolayer have shown that the interaction of ILs with the lipid layer is energetically favourable. The addition of these ILs reduces the in-plane elasticity of the self-assembled molecular layer. Quasielastic neutron scattering data clearly indicate that ILs in liver lipid vesicles significantly affects the dynamics of the lipid, in particular, the lateral motion of the lipids. It has been concluded that the mammalian cell death induced by these ILs is due to the modulated structure and altered physical properties of the cellular membrane. © 2019 Elsevier B.V.

Physics

Biochimica et Biophysica Acta - Biomembranes

Imidazolium-based ionic liquids cause mammalian cell death due to modulated structures and dynamics of cellular membrane

We report a case of Wegener's granulomatosis (WG) who very well responded to the combination strategy of therapeutic plasma exchange (TPE) and immunosuppression. The patient was a 38-year-old female, diagnosed with severe form of WG. A total of seven cycles was performed with 1.3 total plasma volumes (TPVs) on every alternate day. Standard induction therapy was also started that comprised of a combination of 500 mg intravenous (i.v.) cyclophosphamide and methylprednisolone 1 g slow i.v. daily for 3 days followed by oral prednisolone 60 mg daily for 4 weeks. After seven cycles of TPE, the patient improved and hence TPE was stopped. © 2020 Asian Journal of Transfusion Science.

Asian Journal of Transfusion Science

Therapeutic plasma exchange: A life-saving modality in Wegener's granulomatosis

A biostratigraphic and biochronological study from the late Neogene-Quaternary section of Ocean Drilling Pro-gram (ODP) Site 807A, located on the Ontong Java Plateau, western equatorial Pacific, revealed 50 planktic foraminiferal events, enabling the identification of eight late Neogene-Quaternary biozones, from the Globorotalia plesiotumida Interval Zone to the Globorotalia truncatulinoides Interval Zone. A significant faunal turnover (17 events) from late Pliocene identified in cores 7 and 8, between 70 and 55 meters below seafloor (mbsf), and spanning 0.67 million years (Myr). This noteworthy turnover may be the result of a shift in oceanographic conditions pertaining to the closure of the Indo-Pacific Seaway, followed by the Northern Hemisphere Glaciation. This study provides a high resolution biostrati-graphic and biochronological framework for ODP Site 807A that will aid in correlation and timing the various paleoceano-graphic changes over the last 6 million years in the western equatorial Pacific. © 2020 Cushman Foundation. All rights reserved.

Journal of Foraminiferal Research

Late Neogene-Quaternary Planktic Foraminiferal Biostratigraphy and Biochronology from ODP Site 807A, Ontong Java Plateau, Western Equatorial Pacific

Background: Salidroside is a glucoside of tyrosol found mostly in the roots of Rhodiola spp. It exhibits diverse biological and pharmacological properties. In the last decade, enormous research is conducted to explore the medicinal properties of salidroside; this research reported many activities like anti-cancer, anti-oxidant, anti-aging, anti-diabetic, anti-depressant, anti-hyperlipidemic, anti-inflammatory, immunomodulatory, etc. Objective: Despite its multiple pharmacological effects, a comprehensive review detailing its metabolism and therapeutic activities is still missing. This review aims to provide an overview of the metabolism of salidroside, its role in alleviating different metabolic disorders, diseases and its molecular interaction with the target molecules in different conditions. This review mostly concentrates on the metabolism, biological activities and molecular pathways related to various pharmacological activities of salidroside. Conclusion: Salidroside is produced by a three-step pathway in the plants with tyrosol as an intermediate molecule. The molecule is biotransformed into many metabolites through phase I and II pathways. These metabolites, together with a certain amount of salidroside may be responsible for various pharmacological functions. The salidroside based inhibition of PI3k/AKT, JAK/ STAT, and MEK/ERK pathways and activation of apoptosis and autophagy are the major reasons for its anti-cancer activity. AMPK pathway modulation plays a significant role in its anti-diabetic activity. The neuroprotective activity was linked with decreased oxidative stress and increased antioxidant enzymes, Nrf2/HO-1 pathways, decreased inflammation through suppression of NF-κB pathway and PI3K/AKT pathways. These scientific findings will pave the way to clinically translate the use of salidroside as a multi-functional drug for various diseases and disorders in the near future. © 2020, Bentham Science Publishers. All rights reserved.

Current Drug Metabolism

Salidroside-can it be a multifunctional drug?

Patients who suffer from chronic obstructive pulmonary disease (COPD) often experience deterioration of baseline respiratory symptoms, acute exacerbations of COPD (AECOPD), that become more frequent with disease progression. Based on symptom severity, approximately 20% of these patients will require hospitalization. The most common indicators for intensive care unit (ICU) admission have been found to be worsening or impending respiratory failure and hemodynamic instability. Bacterial and viral bronchial infections are the causative triggers in the majority of COPD exacerbations in the ICU, with a comprehensive assessment revealing them in 72% of cases. The distribution of bacterial pathogens involved in AECOPD requiring ICU admission show an increased incidence of gram-negative respiratory isolates, including Pseudomonas and Enterobacteriaceae spp., when compared with outpatient exacerbations. Evaluation of these patients requires careful attention to comorbid conditions. An effort to rapidly obtain lower respiratory samples for microbiological samples prior to initiation of antibiotics should be made as adequate samples can guide subsequent modifications of antibiotic treatment if the clinical response to empiric treatment is poor. Empiric antibiotic treatment should be promptly initiated in all patients with a major consideration for the choice being the presence of risk factors for Pseudomonas infection. Evaluation of clinical response at 48 to 72 hours is crucial, and total duration of antibiotics of 5 to 7 days should be adequate. © 2020 Royal Society of Chemistry. All rights reserved.