Biology subjects

Roy, A. N.

Publications and source records attributed to Roy, A. N..

3 recordsLinked to original sources

bioRxiv2026

Complex Modulation of IL-6 Signaling by Apelin and Elabela in HTR-8/SVneo Cells Under Cobalt Chloride Induced Chemical Hypoxia

Preeclampsia is a pregnancy complication characterized by hypertension, proteinuria, and end-organ dysfunction. Abnormal placentation leading to reduced placental perfusion may contribute to its development. Previous studies demonstrated that the activation of the apelin receptor (APJ) system has hypotensive, renoprotective, and antioxidant effects in preeclamptic rat models. Apelin and elabela (ELA) can stimulate the proliferation of trophoblast cells, suggesting a role in embryonic development. However, the mechanisms underlying the actions of apelin or ELA in trophoblast cells are not well understood, particularly in hypoxic settings. The immortalized HTR-8/SVneo trophoblastic cells were treated with cobalt chloride (CoCl2) at 0.2 mM for 24 hours to mimic hypoxic conditions. RT-qPCR, ELISA or Western blotting was used to measure mRNA or protein levels of apelin, elabela, and the components of IL-6 signaling in cell lysates or conditioned media. The exposure to CoCl2 increased total apelin and elabela content approximately 2-fold in the conditioned media but did not affect APJ levels. CoCl2 upregulated proinflammatory cytokine concentrations: soluble fms-like tyrosine kinase 1 (sFlt-1), soluble gp130 (sgp130), interleukin-6 (IL-6), and sIL-6 receptor (IL-s6R). Both apelin and elabela downregulated IL-6 mRNA but had no effect on sFlt-1 mRNA. Apelin attenuated sgp130, while ELA decreased the membrane form of IL-s6R. Apelin also decreased the pSTAT3/STAT3 ratio. CoCl2-induced hypoxia upregulated the pro-inflammatory milieu in HTR-8/SVneo cells. Local activation of this peptidergic system may be a compensatory response of the trophoblast cells to hypoxia as exogenous apelin and elabela treatment ameliorated the hypoxia-induced pro-inflammatory milieu.

molecular biology↗

bioRxiv2025

Repurposing Melatonin in dual-mode for Wilson disease therapy as a Copper Chelator and an antioxidant agent

Loss-of-function mutations in copper-ATPase ATP7B underlie Wilson disease (WD), a disorder characterized by hepatic copper accumulation and severe hepato-neuropathology. Existing chelation therapeutics remove excess copper but lack intrinsic antioxidant capacity and frequently cause systemic toxicity. Here we evaluate melatonin, an FDA-approved indoleamine with antioxidant and putative metal-chelating activity, as a candidate therapeutic for WD. In ATP7B-/- hepatocytes, melatonin restored copper-induced reactive oxygen species (ROS) to basal levels, reduced apoptosis twofold, and attenuated Nrf2 nuclear translocation leading to reduction of Hemoxygenase-1 abundance. Live-cell ratiometric analysis of GSSG/GSH using GRX1-roGFP2 expressed in melatonin-treated ATP7B-/- hepatocytes revealed a significant reduction in intensity-ratio, indicating an effective mitigation of copper-induced glutathione oxidation. Isothermal calorimetric titration revealed moderate Cu2+ affinity (K ITC=4.54 x 103 M-{superscript 1}), rationalized by MD-simulations showing an interaction energy of 18.5 x 10-3 kcal{middle dot}mol-{superscript 1} via amide-Cu{superscript 2} coordination. In-cellulo studies also revealed that copper-induced vesicularized ATP7B reinstates to Golgi in melatonin-treated hepatocytes. In vivo, melatonin treatment reduced copper-induced oxidative stress in zebrafish embryos and lowered copper burden in Caenorhabditis elegans WD model. Our studies revealed that encapsulation of melatonin within an engineered polymeric nanocapsules having dithiol linkers, susceptible to cleavage by GSH, extended melatonins circulatory half-life ten-fold and enhanced its ROS-scavenging efficacy three-fold relative to free melatonin. This work introduces a unique dual-function therapeutic strategy that integrates antioxidant activity with copper chelation, simultaneously addressing copper overload and redox imbalance. Repurposing melatonin, with its established clinical safety, offers rapid and cost-effective translational pathway toward WD-therapy while providing a generalizable platform for redox- and metal-associated disorders.

cell biology↗

bioRxiv2023

Unraveling the Interactions between Human DPP4 Receptor, SARS-CoV-2 Variants, and MERS-CoV, converged for Pulmonary Disorders Integrating through Immunoinformatics and Molecular Dynamics

Human coronaviruses like MERS CoV are known to utilize dipeptidyl peptidase 4 (DPP4), apart from angiotensin-converting enzyme 2(ACE2) as potential co-receptor for viral cell entry. DPP4, ubiquitous membrane-bound aminopeptidase is closely associated with elevation of disease severity in comorbidities. In SARS-CoV-2, there is inadequate evidence for combination of spike protein variants with DPP4, and underlying adversity in COVID19. To elucidate this mechanistic basis, we have investigated interaction of spike protein variants with DPP4 through molecular docking and simulation studies. The possible binding interactions between receptor binding domain (RBD) of different spike variants of SARS-CoV-2 and DPP4 have been compared with interactions observed in experimentally determined structure of complex of MERS-CoV with DPP4. Comparative binding affinity confers that Delta-CoV-2:DPP4 shows close proximity with MERS-CoV:DPP4, as depicted from accessible surface area, radius of gyration, number of hydrogen bonding and energy of interactions. Mutation in delta variant, L452R and T478K, directly participate in DPP4 interaction enhancing DPP4 binding. E484K in alpha and gamma variant of spike protein is also found to interact with DPP4. Hence, DPP4 interaction with spike protein gets more suitable due to mutation especially due to L452R, T478K and E484K. Furthermore, perturbation in the nearby residues Y495, Q474 and Y489 is evident due to L452R, T478K and E484K respectively. Virulent strains of spike protein are more susceptible to DPP4 interaction and are prone to be victimized in patients due to comorbidities. Our results will aid the rational optimization of DPP4 as a potential therapeutic target to manage COVID-19 disease severity.

bioinformatics↗