REVIEW | doi:10.20944/preprints202208.0278.v1
Subject: Medicine & Pharmacology, Other Keywords: central stress response system; sympathetic activity; HPA axis; SAR-CoV-2; catecholamine; corti-costeriods; clonidine; dexamethasone
Online: 16 August 2022 (05:07:18 CEST)
We are in amidst of COVID-19 pandemic. Since Dec 2019, severe acute respiratory corona virus (SAR-CoV-2) has infected more than half a billion people killing nearly 7 million people worldwide. Now the BA.5 variant of SARS-CoV-2 is causing mayhem and driving the global surge. Epidemiologist are aware of the fact that this virus is capable of escaping immunity and likely to infect the same person multiple times despite adequate vaccination status. Elderly people of age more than 60 years and those with underlying health conditions are considered as high-risk who are likely to suffer complications and death. While it is tempting to frame complications and mortality from COVID-19 as a simple matter of too much of a virulent virus in too weak of a host, much more is at play here. Framing the pathophysiology of COVID-19 in the context of the Chrousos and Gold model of the central stress response system can shed insight into its complex pathogenesis. Understanding the mechanisms by which pharmacologic modulation of the central stress response system via administration of clonidine and/or dexamethasone may offer an explanation as to why a viral pathogen can be well tolerated and cleared by one host while inflaming and killing another.
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: necroptosis; cisplatin; ototoxicity; organ of corti; spiral ganglion neuron
Online: 19 March 2019 (10:40:20 CET)
Cisplatin induces early-onset ototoxicity, resulting in hearing loss. The exact mechanism by which cisplatin causes ototoxicity remains unclear. The purpose of this study was to identify the involvement of receptor-interacting protein kinase(RIP)3-dependent necroptosis in cisplatin-induced ototoxicity in animal models. Sprague–Dawley rats (SD, 8 week) were treated via intraperitoneal (i.p) injection with cisplatin (16 mg/kg for 1 day), and their hearing thresholds were was measured by the auditory brainstem response (ABR) method. Hematoxylin and eosin (H-E) staining, immunohistochemistry, and western blots were performed to determine the effect of cisplatin-induced ototoxicity on cochlear morphology. H-E stains outlined necroptotic changes in the organ of Cortis (OCs) and spiral ganglion neurons (SGNs). Additionally, immunohistochemistry and western blot analysis showed overexpression of RIP3 in the OCs and SGNs that were treated with cisplatin. These results suggest that RIP3-dependent necroptosis was substantial in cisplatin-induced ototoxicity; inner cochlear regions, the OCs, and SGNs were especially sensitive to necroptosis.