Unraveling the role of miRNAs as biomarkers in Chagas cardiomyopathy: Insights into molecular pathophysiology.

BACKGROUND: Chagas cardiomyopathy (ChCM) is a severe form of Chagas disease and a major cause of cardiovascular morbidity and mortality. The dysregulation of the immune response leads to cardiac remodeling and functional disruptions, resulting in life-threatening complications. Conventional diagnostic methods have limitations, and therapeutic response evaluation is challenging. MicroRNAs (miRNAs), important regulators of gene expression, show potential as biomarkers for diagnosis and prognosis. AIM: This review aims to summarize experimental findings on miRNA expression in ChCM and explore the potential of these miRNAs as biomarkers of Chagas disease. METHODS: The search was conducted in the US National Library of Medicine MEDLINE/PubMed public database using the terms "Chagas cardiomyopathy" OR "Chagas disease" AND "microRNA" OR "miRNA" OR "miR." Additionally, bioinformatics analysis was performed to investigate miRNA-target interactions and explore enrichment pathways of gene ontology biological processes and molecular functions. RESULTS: The miR-21, miR-146b, miR-146a, and miR-155 consistently exhibited up-regulation, whereas miR-145 was down-regulated in ChCM. These specific miRNAs have been linked to fibrosis, immune response, and inflammatory processes in heart tissue. Moreover, the findings from various studies indicate that these miRNAs have the potential as biomarkers for the disease and could be targeted in therapeutic strategies for ChCM. CONCLUSION: In this review, we point out miR-21, miR-146b, miR-146a, miR-155, and miR-145-5p role in the complex mechanisms of ChCM. These miRNAs have been shown as potential biomarkers for precise diagnosis, reliable prognostic evaluation, and effective treatment strategies in the ChCM.

Previous vitamin D status and total cholesterol are associated with SARS-CoV-2 infection.

BACKGROUND: The relationship of vitamin D status and other biochemical parameters with the risk of SARS-CoV-2 infection remains inconclusive, especially in regions with high solar incidence. Therefore, we aimed to associate the 25-hydroxyvitamin D (25(OH)D) concentrations and lipid profile prior to the SARS-CoV-2 tests in a population from a sunny region in Brazil (5 degrees S, 35 degrees W). METHODS: This retrospective cohort study enrolled 1634 patients tested for SARS-CoV-2 of a private medical laboratory with 25(OH)D concentration and lipid profile measured ≥ 7 days before the date of the first SARS-CoV-2 RT-PCR test and were categorized according to 25(OH)D sufficiency (≥30 ng/mL) or insufficiency (<30 ng/mL). Multiple logistic regression analyses were performed to assess risk factors associated with positive tests for SARS-CoV-2. RESULTS: Average serum 25(OH)D was 33.6 ng/mL. Vitamin D deficiency (<20 ng/mL) was only found in 2.6% of the participants. Multivariate analysis demonstrated that patients > 49 y with insufficient 25(OH)D (<30 ng/mL) presented increased odds to test positive for SARS-CoV-2 (OR: 2.02, 95 %CI: 1.15 to 3.55, P = 0.015). The same is observed among those with total cholesterol > 190 mg/dL (OR: 1.90, 95 %CI: 1.10 to 3.28, P = 0.020). CONCLUSIONS: Previous insufficient 25(OH)D (<30 ng/mL) concentration and high total cholesterol were associated with SARS-CoV-2 infection among adults > 48 y in the study population. Further studies should be conducted to confirm whether measurement of 25(OH)D and lipid profile could be useful to identify patients who are more susceptible to COVID-19.