The SARS-CoV-2 spike protein binds and modulates estrogen receptors

Sex differences in airway disease: estrogen and airway surface liquid dynamics

Biological sex differences exist for many airway diseases in which females have either worse or better health outcomes. Inflammatory airway diseases such as cystic fibrosis (CF) and asthma display a clear male advantage in post-puberty while a female benefit is observed in asthma during the pre-puberty years. The influence of menstrual cycle stage and pregnancy on the frequency and severity of pulmonary exacerbations in CF and asthma point to a role for sex steroid hormones, particularly estrogen, in underpinning biological sex differences in these diseases. There are many ways by which estrogen may aggravate asthma and CF involving disturbances in airway surface liquid (ASL) dynamics, inappropriate hyper-immune and allergenic responses, as well as exacerbation of pathogen virulence. The deleterious effect of estrogen on pulmonary function in CF and asthma contrasts with the female advantage observed in airway diseases characterised by pulmonary edema such as pneumonia, acute respiratory distress syndrome (ARDS) and COVID-19. Airway surface liquid hypersecretion and alveolar flooding are hallmarks of ARDS and COVID-19, and contribute to the morbidity and mortality of severe forms of these diseases. ASL dynamics encompasses the intrinsic features of the thin lining of fluid covering the airway epithelium which regulate mucociliary clearance (ciliary beat, ASL height, volume, pH, viscosity, mucins, and channel activating proteases) in addition to innate defence mechanisms (pathogen virulence, cytokines, defensins, specialised pro-resolution lipid mediators, and metabolism). Estrogen regulation of ASL dynamics contributing to biological sex differences in CF, asthma and COVID-19 is a major focus of this review.

Receptors and Cofactors That Contribute to SARS-CoV-2 Entry: Can Skin Be an Alternative Route of Entry?

To prevent the spread of SARS-CoV-2, all routes of entry of the virus into the host must be mapped. The skin is in contact with the external environment and thus may be an alternative route of entry to transmission via the upper respiratory tract. SARS-CoV-2 cell entry is primarily dependent on ACE2 and the proteases TMPRSS2 or cathepsin L but other cofactors and attachment receptors have been identified that may play a more important role in specific tissues such as the skin. The continued emergence of new variants may also alter the tropism of the virus. In this review, we summarize current knowledge on these receptors and cofactors, their expression profile, factors modulating their expression and their role in facilitating SARS-CoV-2 infection. We discuss their expression in the skin and their possible involvement in percutaneous infection since the presence of the virus has been detected in the skin.

Androgen receptor, a possible anti-infective therapy target and a potent immune respondent in SARS-CoV-2 spike binding: a computational approach

BACKGROUND

Although androgen in gender disparity of COVID-19 has been implied, no direct link has been provided.

RESEARCH DESIGN AND METHODS

Here, we applied AlphaFold multimer, network and single cells database analyses to highlight specificity of Androgen receptor (AR) against spike receptor binding protein (RBD) of SARS-CoV-2.

RESULTS

LXXL motifs in spike RBD are essential for AR binding. RBD LXXA mutation complex with the AR depicting slightly reduced binding energy, as LXXLL motif usually mediates nuclear receptor binding to coregulators. Moreover, AR preferred to bind a LYRL motif in specificity and interaction interface, and showed reduced affinity against Omicron compared to other variants (alpha, beta, gamma, and delta). Importantly, RBD LYRL motif is a conserved antigenic epitope (9 residues) for T-cell response. Network analysis of AR-related genes against COVID-19 database showed T-cell signaling regulation, and CD8+ T-cell spatial location in AR+ single cells, which is consistent with the AR binding motif LYRL in epitope function.

CONCLUSIONS

We provided the potent mechanisms of AR binding to RBD linking to immune response and vaccination shift. AR could be an anti-infective therapy target for anti-Omicron new lineages.

Simulation of COVID-19 symptoms in a genetically engineered mouse model: implications for the long haulers

The ongoing pandemic (also known as coronavirus disease-19; COVID-19) by a constantly emerging viral agent commonly referred as the severe acute respiratory syndrome corona virus 2 or SARS-CoV-2 has revealed unique pathological findings from infected human beings, and the postmortem observations. The list of disease symptoms, and postmortem observations is too long to mention; however, SARS-CoV-2 has brought with it a whole new clinical syndrome in "long haulers" including dyspnea, chest pain, tachycardia, brain fog, exercise intolerance, and extreme fatigue. We opine that further improvement in delivering effective treatment, and preventive strategies would be benefited from validated animal disease models. In this context, we designed a study, and show that a genetically engineered mouse expressing the human angiotensin converting enzyme 2; ACE-2 (the receptor used by SARS-CoV-2 agent to enter host cells) represents an excellent investigative resource in simulating important clinical features of the COVID-19. The ACE-2 mouse model (which is susceptible to SARS-CoV-2) when administered with a recombinant SARS-CoV-2 spike protein (SP) intranasally exhibited a profound cytokine storm capable of altering the physiological parameters including significant changes in cardiac function along with multi-organ damage that was further confirmed via histological findings. More importantly, visceral organs from SP treated mice revealed thrombotic blood clots as seen during postmortem examination. Thus, the ACE-2 engineered mouse appears to be a suitable model for studying intimate viral pathogenesis thus paving the way for identification, and characterization of appropriate prophylactics as well as therapeutics for COVID-19 management.

Understanding the Pharmacology of COVID-19 mRNA Vaccines: Playing Dice with the Spike?

Coronavirus disease-19 (COVID-19) mRNA vaccines are the mainstays of mass vaccination campaigns in most Western countries. However, the emergency conditions in which their development took place made it impossible to fully characterize their effects and mechanism of action. Here, we summarize and discuss available evidence indicating that COVID-19 mRNA vaccines better reflect pharmaceutical drugs than conventional vaccines, as they do not contain antigens but an active SARS-CoV-2 S protein mRNA, representing at the same time an active principle and a prodrug, which upon intracellular translation results in the endogenous production of the SARS-CoV-2 S protein. Both vaccine-derived SARS-CoV-2 S protein mRNA and the resulting S protein exhibit a complex pharmacology and undergo systemic disposition. Defining COVID-19 mRNA vaccines as pharmaceutical drugs has straightforward implications for their pharmacodynamic, pharmacokinetic, clinical and post-marketing safety assessment. Only an accurate characterization of COVID-19 mRNA vaccines as pharmaceutical drugs will guarantee a safe, rational and individualized use of these products.