Type 1 diabetes is associated with significant changes of ACE and ACE2 expression in peripheral blood mononuclear cells

Background and aims: The renin-angiotensin system (RAS), which is a key mediator of cardiovascular homeostasis, has two main axes. The classic one, including angiotensin-converting enzyme (ACE) and Angiotensin (Ang) II, promoting vasoconstriction, and the “alternative” one, including ACE2 and Ang1-7, with opposed actions to AngII. ACE2 has been identified as the main receptor of SARS-CoV2, whereby it enters the cells, leading to the downregulation of surface ACE2 and RAS tissue unbalance. Given that diabetes is associated with an increase in COVID-19 severity and death, we aimed at evaluating RAS expression in patients with type 1 diabetes (T1D). Methods and results: This is a case–control study comparing 39 T1D patients to 33 controls, with a median age of 29 and 32 years, and no comorbidities. ACE and ACE2 gene expression was assessed in peripheral blood mononuclear cells. T1D patients had higher ACE expression and circulating AngII, which were related to glucose levels. T1D patients had lower ACE2 expression. However, ACE2 expression was also related to the sex of participants, being higher in the female group. T1D women did not show the same increase of ACE2 expression that was seen in control women. Conclusion: T1D promotes the increase of ACE, AngII, and ACE/ACE2, which might contribute to the higher cardiovascular risk, as well as to severe tissue injury induced by SARS-CoV2 in these patients. The ratio ACE/ACE2 does not differ between men and women with T1D, which might explain why CVD or COVID-19 do not show substantial gender differences in these patients.