What began with a sign of pneumonia-related respiratory disorders in China has now become a pandemic named by WHO as Covid-19 known to be caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). The SARS-CoV-2 are newly emerged b coronaviruses belonging to the Coronaviridae family. SARS-CoV-2 has a positive viral RNA genome expressing open reading frames that code for structural and non-structural proteins. The structural proteins include spike (S), nucleocapsid (N), membrane (M), and envelope (E) proteins. The S1 subunit of S protein facilitates ACE2 mediated virus attachment while S2 subunit promotes membrane fusion. The presence of glutamine, asparagine, leucine, phenylalanine and serine amino acids in SARS-CoV-2 enhances ACE2 binding. The N protein is composed of a serine-rich linker region sandwiched between N Terminal Domain (NTD) and C Terminal Domain (CTD). These terminals play a role in viral entry and its processing post entry. The NTD forms orthorhombic crystals and binds to the viral genome. The linker region contains phosphorylation sites that regulate its functioning. The CTD promotes nucleocapsid formation. The E protein contains a NTD, hydrophobic domain and CTD which form viroporins needed for viral assembly. The M protein possesses hydrophilic C terminal and amphipathic N terminal. Its long-form promotes spike incorporations and the interaction with E facilitates virion production. As each protein is essential in viral functioning, this review describes the insights of SARS-CoV-2 structural proteins that would help in developing therapeutic strategies by targeting each protein to curb the rapidly growing pandemic.
As the incidence of COVID-19 increases with time, more and more efforts are made to pave a way out for the therapeutic strategies to deal with the disease progression. Inflammation being a significant influencer has implicated us to re-look into its signaling cascades drawing attention towards the JAK/STAT pathway. Considered as a major signaling mediator of cytokines and chemokines, the JAK/STAT pathway has significantly contributed to the worsening of COVID-19. JAK phosphorylation mediated by cytokine receptor activation leads to phosphorylation of STATs that translocate into the nucleus to translate for inflammatory mediators. The SARS-CoV-2 infection triggers the inflammation via the JAK/STAT pathway mainly through its structural and non-structural proteins leading towards the development of cytokine storms. This produces various inflammatory markers in the host that determine the disease severity. Therefore, inhibiting JAK/STAT signaling with JAK/STAT inhibitors like Ruxolitinib, Baricitinib, Tofacitinib could hamper the inflammatory cascade and reduce inflammation. Even though they are implicated with multiple adverse effects, the regulatory authorities have supported its use, and numerous clinical trials are in progress to prove their safety and efficacy. On the contrary, the exact mechanism of JAK/STAT inhibition at molecular levels remains to be speculative for which further investigations are required.
Purpose of Review The rapid spread of virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has turned out to be a global emergency. Symptoms of this viral infection, coronavirus disease 2019 (COVID-19), include mild infections of the upper respiratory tract, viral pneumonia, respiratory failure, multiple organ failure and death. Till date, no drugs have been discovered to treat COVID-19 patients, and therefore, a considerable amount of interest has been shown in repurposing the existing drugs. Recent Findings Out of these drugs, chloroquine (CQ) and hydroxychloroquine (HCQ) have demonstrated positive results indicating a potential antiviral role against SARS-CoV-2. Its mechanism of action (MOA) includes the interference in the endocytic pathway, blockade of sialic acid receptors, restriction of pH mediated spike (S) protein cleavage at the angiotensin-converting enzyme 2 (ACE2) binding site and prevention of cytokine storm. Unfortunately, its adverse effects like gastrointestinal complications, retinopathy and QT interval prolongation are evident in treated COVID-19 patients. Yet, multiple clinical trials have been employed in several countries to evaluate its ability in turning into a needed drug in this pandemic. Summary This review attempts to summarize the MOA of CQ/HCQ and its side effects. The existing literature hints that till date, the role of CQ/HCQ in COVID-19 may be sceptical, and further studies are warranted for obtaining a therapeutic option that could be effectively used across the world to rise out from this pandemic.
The world is fuming at SARS-CoV-2 for being the culprit for causing the devastating COVID-19, claiming millions of lives across the globe in the form of respiratory disorders. But lesser known are its effects on the CNS that are slowly surfacing in the worldwide population. Our review illustrates findings that claim SARS-CoV-2's arrival onto the ACE2 receptors of neuronal and glial cells mainly via CSF, olfactory nerve, trigeminal nerve, neuronal dissemination, and hematogenous pathways. The role of SARS-CoV-2 structural proteins in its smooth viral infectivity of the host cannot be ignored, especially the spike proteins that mediate spike attachment and host membrane fusion. Worth mentioning the nucleocapsid, envelope, and membrane proteins make the proliferation of SARS-CoV-2 much simpler than expected in spreading infection. This has led to catastrophic conditions like seizures, Guillain-Barré syndrome, viral encephalitis, meningoencephalitis, acute cerebrovascular disease, and respiratory failures. Placing a magnifying lens on the lesser-explored CNS consequences of COVID-19, we attempt to shift the focus of our readers onto the new supporting threats to which further studies are needed.
Adenoid cystic carcinoma of the lower respiratory tract is an uncommon tumor that can arise in the mainstem bronchus and often presents as an endobronchial mass lesion causing bronchial obstruction with post obstructive atelectasis and pneumonia. Exfoliative cytology is seldom useful in the diagnosis of primary bronchial adenoid cystic carcinoma, because these neoplasms usually have a submucosal location with often intact mucosa. Since most endobronchial adenoid cystic carcinomas are endoscopically visible, bronchoscope-guided fine-needle aspiration constitutes an excellent approach to establish a pathologic diagnosis. The fine-needle aspiration cytology of primary pulmonary adenoid cystic carcinoma has been rarely described. We report a case of primary adenoid cystic carcinoma of the lung having characteristic cytologic features and correlate with computed tomography, bronchoscopic, and histological findings. Bronchoscope-guided aspiration cytology provided a conclusive diagnosis of adenoid cystic carcinoma, which was further corroborated by histology in the pneumonectomy specimen. Diagn. Cytopathol. 2004;30:51-56.
These findings suggest the antidementia activity of caffeic acid against AlCl3 -induced dementia in rats. The outcome of present study offers a wider scope to screen caffeic acid against neurodegeneration associated disorders.
Objectives. Aluminium, a neurotoxic agent in humans, has been implicated in the pathogenesis of neurodegenerative disorders. In this study, we examined the behavioral and biochemical effects of aluminium in rats with special emphasis on memory centres, namely, hippocampus and frontal cortex. Further, the effect of simvastatin treatment on aluminium intoxication was evaluated. Methods. Rats were exposed to aluminium chloride (AlCl3) for 60 days. Simvastatin (10 mg/kg/p.o.) and rivastigmine (1 mg/kg/p.o.) were administered daily prior to AlCl3. Behavioral parameters were assessed using Morris water maze test and actophotometer followed by biochemical investigations, namely, acetylcholinesterase (AChE) activity, TNF-α level, antioxidant enzymes (GSH, catalase), lipid peroxidation, and nitrite level in hippocampus and frontal cortex. Triglycerides, total cholesterol, LDL, and HDL levels in serum were also determined. Key Findings. Simvastatin treatment improved cognitive function and locomotor activity in rats. Simvastatin reversed hyperlipidemia and significantly rectified the deleterious effect of AlCl3 on AChE activity. Further, in hippocampus and frontal cortex, aluminium-induced elevation in nitrite and TNF-α and reduction in antioxidant enzymes were inhibited by simvastatin. Conclusion. To conclude, the present study suggests that simvastatin per se protects the neurons in hippocampus and frontal cortex from AlCl3, an environmental toxin.
Insulin is a cytokine which promotes cell growth. Recently, a few published reports on insulin in different cell lines support the antiapoptotic effect of insulin. But the reports fail to explain the role of insulin in modulating glutamate-mediated neuronal cell death through excitotoxicity. Thus, we examined the neuroprotective effect of insulin on glutamate-induced toxicity on differentiated SH-SY5Y neuronal cells. Changes in cell viability were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) based assay, while apoptotic damage was detected by acridine orange/ethidium bromide and Hoechst staining. Intracellular reactive oxygen species (ROS) accumulation and morphological alterations were also measured. Treatment with glutamate induced apoptosis, elevated ROS levels and caused damage to neurons. Insulin was able to attenuate the glutamate-induced excitotoxic damage to neuronal cells.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.