MicroRNAs Regulating Renin-Angiotensin-Aldosterone System, Sympathetic Nervous System and Left Ventricular Hypertrophy in Systemic Arterial Hypertension.

MicroRNAs are small non-coding RNAs that regulate gene and protein expression. MicroRNAs also regulate several cellular processes such as proliferation, differentiation, cell cycle, apoptosis, among others. In this context, they play important roles in the human body and in the pathogenesis of diseases such as cancer, diabetes, obesity and hypertension. In hypertension, microRNAs act on the renin-angiotensin-aldosterone system, sympathetic nervous system and left ventricular hypertrophy, however the signaling pathways that interact in these processes and are regulated by microRNAs inducing hypertension and the worsening of the disease still need to be elucidated. Thus, the aim of this review is to analyze the pattern of expression of microRNAs in these processes and the possible associated signaling pathways.

The Impact of COVID-19 on the Cardiovascular System

SUMMARY The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces coronavirus-19 disease (COVID-19), has affected many people in Brazil and worldwide. This disease predominantly affects the organs of the respiratory system, but it also damages the brain, liver, kidneys and especially the heart. In the heart, scientific evidence shows that this virus can damage the coronary arteries, generating microvascular dysfunction, favoring acute myocardial infarction. Furthermore, with the increased expression of pro-inflammatory cytokines, it can lead to myocarditis and cardiac fibrosis, inducing changes in the electrical conduction system of the heart, generating cardiac arrhythmias. All these factors mentioned are protagonists in promoting the increase in the mortality outcome. This outcome may be even higher if the individuals are elderly, or if they have other diseases such as type 2 diabetes mellitus or hypertension, because they may already have cardiomyopathy. In this context, this review focused on the impact that COVID-19 can have on the heart and cardiovascular system and the association of this impact with aging, type 2 diabetes mellitus, cardiac arrhythmias and arterial hypertension

Physical exercise and immune system: Perspectives on the COVID-19 pandemic

Physical exercise training (PET) has been considered an excellent non-pharmacological strategy to prevent and treat several diseases. There are various benefits offered by PET, especially on the immune system, promoting changes in the morphology and function of cells, inducing changes in the expression pattern of pro and anti-inflammatory cytokines. However, these changes depend on the type, volume and intensity of PET and whether it is being evaluated acutely or chronically. In this context, PET can be a tool to improve the immune system and fight various infections. However, the current COVID-19 pandemic, caused by SARS-CoV-2, which produces cytokine storm, inducing inflammation in several organs, with high infection rates in both sedentary and physically active individuals, the role of PET on immune cells has not yet been elucidated. Thus, this review focused on the role of PET on immune system cells and the possible effects of PET-induced adaptive responses on SARS-CoV-2 infection and COVID-19.

High-intensity interval training improves cerebellar antioxidant capacity without affecting cognitive functions in rats.

High-intensity interval training (HIIT) is associated with better physical performance, but there is limited information about the effects of HIIT on redox state of cerebellar tissue, cerebral cortex, and cognition. The aim of this study was to evaluate the effects of HIIT on redox state parameters in cerebellar tissue, cerebral cortex, and cognitive function of Wistar rats. Forty-three young male Wistar rats were housed under controlled environmental conditions with food, and water ad libitum. Animals were assigned to HIIT or Non-trained groups. HIIT protocol was performed during six weeks. Speed was determined through the assesstment of the maximum oxygen consumption (VO2max). HIIT consisted of short bouts (1 min) running on a treadmill at 10° inclination (85-100% of VO2max) with 2 min of active recovery (60% of VO2max, without inclination). Non-trained group was daily exposed to a disconnected treadmill for the same amount of time as HITT group. Both groups were submitted to the open field, and novel object recognition tasks after six weeks. Malondialdehyde concentration (MDA), superoxide dismutase (SOD) activity, and non-enzymatic antioxidant capacity (FRAP) were quantified to determine the redox state. HIIT presented increased levels of MDA, SOD, and FRAP (p < 0.05) in the cerebellar tissue, but no differences were seen in cerebral cortex. These results indicated an improved antioxidant capacity, despite increased MDA levels in the cerebellar tissue. Both groups did not present impairment in locomotor activity, development of anxious behavior or cognitive decline. HIIT enhanced the antioxidant defenses on cerebellar tissue with no deleterious effects on rats' cognition.