COVID-19: relationship between angiotensin-converting enzyme 2, cardiovascular system and host immune response

Coronavirus disease 2019 (COVID-19) causes severe acute respiratory syndrome due to coronavirus 2 (SARS-CoV-2), and can be particularly detrimental to patients with underlying cardiovascular disease (CVD), and is a cause of morbidity and mortality. significant worldwide. The virus infects host cells through angiotensin-converting enzyme 2 (ACE2) receptors and their internalization of the complex into that cell. ACE2 is a key enzyme component of the renin-angiotensin-aldosterone (RAAS) system, degrading angiotensin (Ang) II, a peptide with multiple actions that promote CVD, and generating Ang-(1-7), which antagonizes the effects of Ang II. Furthermore, experimental evidence suggests that blocking SRAA by ACE inhibitors and Ang II type 1 receptor antagonists increases ACE2, which in part contributes to the benefit of these patients. This virus leads to lung disease, while causing acute myocardial injury and chronic damage to the cardiovascular system. This myocardial injury occurs in the most severe phase of COVID-19; but still, the pathophysiological mechanism of the injury was not clarified. Therefore, special attention should be paid to cardiovascular protection during treatment for COVID-19. Acute respiratory distress syndrome (ARDS) is a highmortality clinical disease, and ACE2 has a protective effect on this type of acute lung injury. Current research shows that the poor prognosis of COVID-19 patients is related to factors such as male gender, age> 60 years, underlying diseases: hypertension, diabetes and CVD, secondary ARDS, and other relevant factors. Although the data is limited, possible mechanisms of myocardial injury include direct viral entry through the ACE2 membrane receptor and host cell toxicity, hypoxia-related myocyte injury, and cytokine release syndrome. mediated by the immune system, further studies are needed to clarify the mechanism of cardiotoxicity and its prevention. This article updates current knowledge of the biology of SARS-CoV-2 and the possible mechanisms of myocardial injury due to viral toxicities and host immune responses.