Hyperglycemia and Angiotensin-Converting Enzyme 2 in Pulmonary Function in the Context of SARS-CoV-2 Infection

Vascular actions of Ang 1-7 and Ang 1-8 through EDRFs and EDHFs in non-diabetes and diabetes mellitus

The renin-angiotensin system (RAS) plays a pivotal role in regulating vascular homeostasis, while angiotensin 1-8 (Ang 1-8) traditionally dominates as a vasoconstrictor factor. However, the discovery of angiotensin 1-7 (Ang 1-7) and Ang 1-8 has revealed counter-regulatory mechanisms mediated through endothelial-derived relaxing factors (EDRFs) and endothelial-derived hyperpolarizing factors (EDHFs). This review delves into the vascular actions of Ang 1-7 and Ang 1-8 in both non-diabetes mellitus (non-DM) and diabetes mellitus (DM) conditions, highlighting their effects on vascular endothelial cell (VECs) function as well. In a non-DM vasculature context, Ang 1-8 demonstrate dual effect including vasoconstriction and vasodilation, respectively. Additionally, Ang 1-7 induces vasodilation upon nitric oxide (NO) production as a prominent EDRFs in distinct mechanisms. Further research elucidating the precise mechanisms underlying the vascular actions of Ang 1-7 and Ang 1-8 in DM will facilitate the development of tailored therapeutic interventions aimed at preserving vascular health and preventing cardiovascular complications.

Sodium and Water Disorders

The balancing of fluids and electrolytes is a core function of the kidneys. There are redundant mechanisms within the body to sense the adequacy of organ perfusion and the composition of body fluids aimed at maintaining hemodynamics and protecting an environment for optimal cellular function. Sodium and water are key components of extracellular fluid and are regulated in response to end-organ perfusion and serum tonicity. Baroreceptors activate the renin-angiotensin-aldosterone system, sympathetic nervous system, vasopressin, and atrial natriuretic peptide to adjust sodium handling to alter extracellular volume. Osmoreceptors affect anti-diuretic hormone release and aquaporin activity in the medullary collecting duct to modify the handling of water. Disordered handling of sodium and/or water may be adaptive or maladaptive, and understanding the stimuli and responses to clinical scenarios assists clinicians in developing appropriate treatment strategies.

Exercise as a therapeutic approach to alleviate diabetic kidney disease: mechanisms, clinical evidence and potential exercise prescriptions

Diabetic kidney disease (DKD) is a global and severe complication that imposes a significant burden on individual health, families, and society. Currently, the main treatment approaches for DKD include medication, blood glucose control, protein-restricted diet, and blood pressure management, all of which have certain limitations. Exercise, as a non-pharmacological intervention, has attracted increasing attention. This review introduces the mechanisms and clinical evidence of exercise on DKD, and proposes potential exercise prescriptions. Exercise can improve blood glucose stability related to DKD and the renin-angiotensin-aldosterone system (RAAS), reduce renal oxidative stress and inflammation, enhance the crosstalk between muscle and kidneys, and improve endothelial cell function. These mechanisms contribute to the comprehensive improvement of DKD. Compared to traditional treatment methods, exercise has several advantages, including safety, effectiveness, and no significant side effects. It can be used as an adjunct therapy to medication, blood glucose control, protein-restricted diet, and blood pressure management. Despite the evident benefits of exercise in DKD management, there is still a lack of large-scale, long-term randomized controlled trials to provide more evidence and develop exercise guidelines for DKD. Healthcare professionals should actively encourage exercise in DKD patients and develop personalized exercise plans based on individual circumstances.

Long-Term Impacts of COVID-19 on Thyroid Health: Insights From Clinical Studies

BACKGROUND

COVID-19 emerged in December 2019 and rapidly became a global pandemic. It has since been associated with the progression of various endocrine disorders, including thyroid disease. The long-term effects of this interplay have yet to be explored. This review explores the relationship between COVID-19 and thyroid diseases, emphasizing thyroid gland function and the clinical implications for managing thyroid disorders in infected individuals.

OBJECTIVES

This narrative review intends to provide insight into the scope of research that future clinical studies may aim to address regarding the long-term effects of COVID-19 infection on thyroid health.

METHODS

Keywords including "thyroid disease", "COVID-19", and "long-term" were used to search PubMed and Google Scholar for updated and relevant clinical research.

RESULTS

COVID-19 affects the thyroid gland multifacetedly and includes direct viral invasion, immune-mediated damage, and hypothalamic-pituitary-thyroid axis disruption. Approximately 15% of COVID-19 patients experience thyroid dysfunction, which can present as thyrotoxicosis, hypothyroidism, or non-thyroidal illness syndrome (NTI). Noteworthy findings include inflammatory thyroiditis. Long-term effects, including those observed in children, include persistent hypothyroidism and exacerbated pre-existing thyroid-autoimmune conditions. Management of thyroid disorders in COVID-19 patients requires consideration: anti-thyroid drug (ATD) therapy used to treat hyperthyroidism in COVID-19 patients may need adjustment to prevent immunosuppression. Radioactive iodine (ROI) alternatives and interleukin-6 (IL-6) receptor antagonists could offer potential benefits and should be further explored.

CONCLUSION

Longitudinal follow-ups post-COVID-19 for patients with new and pre-existing thyroid disorders can improve disease outcomes. In addition, pathophysiological research on thyroid dysfunction in COVID-19 may help develop strategies to prevent and alleviate thyroid gland abnormalities post-COVID-19.

SARS-CoV-2 infects cells lining the blood-retinal barrier and induces a hyperinflammatory immune response in the retina via systemic exposure

SARS-CoV-2 has been shown to cause wide-ranging ocular abnormalities and vision impairment in COVID-19 patients. However, there is limited understanding of SARS-CoV-2 in ocular transmission, tropism, and associated pathologies. The presence of viral RNA in corneal/conjunctival tissue and tears, along with the evidence of viral entry receptors on the ocular surface, has led to speculation that the eye may serve as a potential route of SARS-CoV-2 transmission. Here, we investigated the interaction of SARS-CoV-2 with cells lining the blood-retinal barrier (BRB) and the role of the eye in its transmission and tropism. The results from our study suggest that SARS-CoV-2 ocular exposure does not cause lung infection and moribund illness in K18-hACE2 mice despite the extended presence of viral remnants in various ocular tissues. In contrast, intranasal exposure not only resulted in SARS-CoV-2 spike (S) protein presence in different ocular tissues but also induces a hyperinflammatory immune response in the retina. Additionally, the long-term exposure to viral S-protein caused microaneurysm, retinal pigmented epithelium (RPE) mottling, retinal atrophy, and vein occlusion in mouse eyes. Notably, cells lining the BRB, the outer barrier, RPE, and the inner barrier, retinal vascular endothelium, were highly permissive to SARS-CoV-2 replication. Unexpectedly, primary human corneal epithelial cells were comparatively resistant to SARS-CoV-2 infection. The cells lining the BRB showed induced expression of viral entry receptors and increased susceptibility towards SARS-CoV-2-induced cell death. Furthermore, hyperglycemic conditions enhanced the viral entry receptor expression, infectivity, and susceptibility of SARS-CoV-2-induced cell death in the BRB cells, confirming the reported heightened pathological manifestations in comorbid populations. Collectively, our study provides the first evidence of SARS-CoV-2 ocular tropism via cells lining the BRB and that the virus can infect the retina via systemic permeation and induce retinal inflammation.

Gene Networks of Hyperglycemia, Diabetic Complications, and Human Proteins Targeted by SARS-CoV-2: What Is the Molecular Basis for Comorbidity?

People with diabetes are more likely to have severe COVID-19 compared to the general population. Moreover, diabetes and COVID-19 demonstrate a certain parallelism in the mechanisms and organ damage. In this work, we applied bioinformatics analysis of associative molecular networks to identify key molecules and pathophysiological processes that determine SARS-CoV-2-induced disorders in patients with diabetes. Using text-mining-based approaches and ANDSystem as a bioinformatics tool, we reconstructed and matched networks related to hyperglycemia, diabetic complications, insulin resistance, and beta cell dysfunction with networks of SARS-CoV-2-targeted proteins. The latter included SARS-CoV-2 entry receptors (ACE2 and DPP4), SARS-CoV-2 entry associated proteases (TMPRSS2, CTSB, and CTSL), and 332 human intracellular proteins interacting with SARS-CoV-2. A number of genes/proteins targeted by SARS-CoV-2 (ACE2, BRD2, COMT, CTSB, CTSL, DNMT1, DPP4, ERP44, F2RL1, GDF15, GPX1, HDAC2, HMOX1, HYOU1, IDE, LOX, NUTF2, PCNT, PLAT, RAB10, RHOA, SCARB1, and SELENOS) were found in the networks of vascular diabetic complications and insulin resistance. According to the Gene Ontology enrichment analysis, the defined molecules are involved in the response to hypoxia, reactive oxygen species metabolism, immune and inflammatory response, regulation of angiogenesis, platelet degranulation, and other processes. The results expand the understanding of the molecular basis of diabetes and COVID-19 comorbidity.