Systems level insights into the impact of airborne exposure on SARS-CoV-2 pathogenesis and COVID-19 outcome - A multi-omics big data study

Aluminium oxide nanoparticles (Al2O3-NPs) exposure impairs cardiovascular physiology and elevates health risk - proteomic and molecular mechanistic insights

The interactions of nanoparticles with biomolecules lead to toxicopathological outcomes through various mechanisms including oxidative stress. In this regard, the interplay of oxidative stress with other molecular mechanisms of cytotoxicity during aluminium oxide nanoparticles (Al2O3-NPs) induced cardiovascular toxicity was not yet precisely explored. Initially, the human serum protein interaction and its corona composition were explored through the gel/label-free proteomics (nLC-HRMS/MS) method. In addition, endothelial cells (EC) and cardiomyoblasts (CM) cultures were employed along with various oxidative stress and cell stress assays. Further, various expression studies (RT-qPCR, western blot, and immunofluorescence), kinase signalling, and siRNA mediated gene knockout assays were performed. Alongside, the in ovo impact on antioxidant enzymes and metabolomic pathways (1H NMR) in the heart validated the role of oxidative stress during cardiotoxicity. The current outcome illustrates the dose-dependent increase of cytotoxicity and caspase (3 and 9) activation. The dose-dependent elevation and its synergy with cardiovascular stress signalling (ET-1 and Ang-II) illustrate the prominent role of oxidative stress during toxicity. In conclusion, the current study connects the role of the redox system and molecular stress pathways during Al2O3-NPs induced cardiotoxicity which extends the knowledge towards the precise health risk assessment during human exposure.

HIF-1α Pathway in COVID-19: A Scoping Review of Its Modulation and Related Treatments

The COVID-19 pandemic, driven by SARS-CoV-2, has led to a global health crisis, highlighting the virus's unique molecular mechanisms that distinguish it from other respiratory pathogens. It is known that the Hypoxia-Inducible Factor 1α (HIF-1α) activates a complex network of intracellular signaling pathways regulating cellular energy metabolism, angiogenesis, and cell survival, contributing to the wide range of clinical manifestations of COVID-19, including Post-Acute COVID-19 Syndrome (PACS). Emerging evidence suggests that dysregulation of HIF-1α is a key driver of systemic inflammation, silent hypoxia, and pathological tissue remodeling in both the acute and post-acute phases of the disease. This scoping review was conducted following PRISMA-ScR guidelines and registered in INPLASY. It involved a literature search in Scopus and PubMed, supplemented by manual reference screening, with study selection facilitated by Rayyan software. Our analysis clarifies the dual role of HIF-1α, which may either worsen inflammatory responses and viral persistence or support adaptive mechanisms that reduce cellular damage. The potential for targeting HIF-1α therapeutically in COVID-19 is complex, requiring further investigation to clarify its precise role and translational applications. This review deepens the molecular understanding of SARS-CoV-2-induced cellular and tissue dysfunction in hypoxia, offering insights for improving clinical management strategies and addressing long-term sequelae.

Human circulatory proteome interaction, oxidative stress-associated signalling and cardiovascular implications during titanium dioxide nanoparticle (TiO2-NP) exposure

The increasing exposure to nanoparticles raises a concern over their toxicity. Incidentally, reactive oxygen species (ROS) are produced as a result of the nanoparticle's physicochemical characteristics and interactions with intracellular elements, primarily enzymes, leading to oxidative stress. In this context, the extent of oxidative stress resulting from the toxicity of titanium dioxide nanoparticles (TiO2-NPs) on the cardiovascular system has not yet been thoroughly investigated. Initially, the gel/label-free proteomics (nLC-HRMS/MS) method was used to examine human serum protein interaction and corona composition. Furthermore, different oxidative stress assays (superoxide, total ROS, mitochondrial ROS, and lipid peroxidation) and cell stress assays (apoptosis, ER stress, mitochondrial dysfunction, autophagy, and hypertrophy) were performed in conjunction with endothelial (rat aortic cells) and cardiomyoblast (H9c2) cell cultures. In addition, expression studies (RT-qPCR and immunofluorescence), kinase signalling, and siRNA-mediated gene knockout (NOX2 and XO) studies were conducted. Alongside, in ovo effects on the heart's antioxidant enzymes (SOD and CAT) and metabolomic pathways (1H NMR) confirmed the involvement of oxidative stress in cardiotoxicity. The present results demonstrate a dose-dependent increase in cytotoxicity via the activation of caspase 3 and 9. The dose-dependent increase and its synergistic relationship with cardiovascular stress signalling (ET-1 and Ang-II) highlight the significant role of oxidative stress in nanoparticle toxicity. In summary, this study expands our understanding of the precise health risks associated with human exposure by establishing a connection between the role of the redox system and molecular stress pathways in TiO2-NPs-induced cardiotoxicity.

COVID-19: Post infection implications in different age groups, mechanism, diagnosis, effective prevention, treatment, and recommendations

SARS-CoV-2 is a highly contagious pathogen that predominantly caused the COVID-19 pandemic. The persistent effects of COVID-19 are defined as an inflammatory or host response to the virus that begins four weeks after initial infection and persists for an undetermined length of time. Chronic effects are more harmful than acute ones thus, this review explored the long-term effects of the virus on various human organs, including the pulmonary, cardiovascular, and neurological, reproductive, gastrointestinal, musculoskeletal, endocrine, and lymphoid systems and found that SARS-CoV-2 adversely affects these organs of older adults. Regarding diagnosis, the RT-PCR is a gold standard method of diagnosing COVID-19; however, it requires specialized equipment and personnel for performing assays and a long time for results production. Therefore, to overcome these limitations, artificial intelligence employed in imaging and microfluidics technologies is the most promising in diagnosing COVID-19. Pharmacological and non-pharmacological strategies are the most effective treatment for reducing the persistent impacts of COVID-19 by providing immunity to post-COVID-19 patients by reducing cytokine release syndrome, improving the T cell response, and increasing the circulation of activated natural killer and CD8 T cells in blood and tissues, which ultimately reduces fever, nausea, fatigue, and muscle weakness and pain. Vaccines such as inactivated viral, live attenuated viral, protein subunit, viral vectored, mRNA, DNA, or nanoparticle vaccines significantly reduce the adverse long-term virus effects in post-COVID-19 patients; however, no vaccine was reported to provide lifetime protection against COVID-19; consequently, protective measures such as physical separation, mask use, and hand cleansing are promising strategies. This review provides a comprehensive knowledge of the persistent effects of COVID-19 on people of varying ages, as well as diagnosis, treatment, vaccination, and future preventative measures against the spread of SARS-CoV-2.

Risk Factors of Severe COVID-19: A Review of Host, Viral and Environmental Factors

The clinical course and outcome of COVID-19 are highly variable, ranging from asymptomatic infections to severe disease and death. Understanding the risk factors of severe COVID-19 is relevant both in the clinical setting and at the epidemiological level. Here, we provide an overview of host, viral and environmental factors that have been shown or (in some cases) hypothesized to be associated with severe clinical outcomes. The factors considered in detail include the age and frailty, genetic polymorphisms, biological sex (and pregnancy), co- and superinfections, non-communicable comorbidities, immunological history, microbiota, and lifestyle of the patient; viral genetic variation and infecting dose; socioeconomic factors; and air pollution. For each category, we compile (sometimes conflicting) evidence for the association of the factor with COVID-19 outcomes (including the strength of the effect) and outline possible action mechanisms. We also discuss the complex interactions between the various risk factors.

Iron dysregulation in COVID-19 and reciprocal evolution of SARS-CoV-2: Natura nihil frustra facit

After more than a year of the COVID-19 pandemic, SARS-CoV-2 infection rates with newer variants continue to devastate much of the world. Global healthcare systems are overwhelmed with high positive patient numbers. Silent hypoxia accompanied by rapid deterioration and some cases with septic shock is responsible for COVID-19 mortality in many hospitalized patients. There is an urgent need to further understand the relationships and interplay with human host components during pathogenesis and immune evasion strategies. Currently, acquired immunity through vaccination or prior infection usually provides sufficient protection against the emerging variants of SARS-CoV-2 except Omicron variant requiring recent booster. New strains have shown higher viral loads and greater transmissibility with more severe disease presentations. Notably, COVID-19 has a peculiar prognosis in severe patients with iron dysregulation and hypoxia which is still poorly understood. Studies have shown abnormally low serum iron levels in severe infection but a high iron overload in lung fibrotic tissue. Data from our in-silico structural analysis of the spike protein sequence along with host proteolysis processing suggests that the viral spike protein fragment mimics Hepcidin and is resistant to the major human proteases. This functional spike-derived peptide dubbed "Covidin" thus may be intricately involved with host ferroportin binding and internalization leading to dysregulated host iron metabolism. Here, we propose the possible role of this potentially allogenic mimetic hormone corresponding to severe COVID-19 immunopathology and illustrate that this molecular mimicry is responsible for a major pathway associated with severe disease status. Furthermore, through 3D molecular modeling and docking followed by MD simulation validation, we have unraveled the likely role of Covidin in iron dysregulation in COVID-19 patients. Our meta-analysis suggests the Hepcidin mimetic mechanism is highly conserved among its host range as well as among all new variants to date including Omicron. Extensive analysis of current mutations revealed that new variants are becoming alarmingly more resistant to selective human proteases associated with host defense.