Tissue‐Specific Differences in Myocardial and Coronary Vascular ACE2 and TMPRSS2 mRNA Levels are Dependent Upon Sex, Comorbidities, Pressure‐Overload, and Pig Species

Kelly, Shannon; Thorne, Pamela; Leary, Emily; Emter, Craig

SARS‐COV‐2, or COVID‐19, is a respiratory virus infecting over 86 million people worldwide. In addition to respiratory infections, SARS‐COV‐2 has been shown to include cardiovascular (CV) complications, including myocarditis and acute coronary syndrome. Risk of severe complications from SARS‐COV‐2 in individuals with existing CV and metabolic disease has been shown to be increased. Evidence indicates SARS‐COV‐2 enters tissues via the angiotensin‐converting enzyme 2 (ACE2) receptor and that the virus is primed and activated by transmembrane protease, serine 2 (TMPRSS2). The goal of this study was to determine ACE2 and TMPRSS2 mRNA levels in pre‐clinical swine models of heart failure (HF). We hypothesized sex, pressure‐overload, and comorbidities would increase ACE2 and TMPRSS2 mRNA levels. A retrospective analysis was conducted in previously completed studies in our lab including: 1) Female, intact Ossabaw swine that were either lean control or western diet‐fed aortic‐banded (N=4‐5/group); 2) Female Yucatan mini‐swine subject to ovariectomy and/or aortic banding (N=5‐8/group); and 3) Sedentary and exercise trained male, intact Yucatan mini‐swine that were aortic banded. ACE2 and TMPRSS2 mRNA levels were evaluated in the left ventricle (LV), right ventricle (RV), and coronary vasculature using qRT‐PCR. Linear regression analysis was used to determine differences between the following variables: pig species, sex hormones, aortic banding, comorbidities, exercise training, and tissue. Data was log‐transformed to meet linear regression assumptions. ACE2 and TMPRSS2 mRNA levels were significantly influenced by sex, comorbidity, and tissue type. TMPRSS2 mRNA levels were also influenced by species and disease status. Specifically, ACE2 mRNA levels decreased 57.1% in the LV and increased 169.9% in the RV of males compared to coronary vessels in intact females. TMPRSS2 mRNA levels increased in the LV and RV of males (1,218.6% and 5,479.8%, respectively) compared to coronary vessels in intact females. ACE2 and TMPRSS2 mRNA levels increased 344% and 453.4%, respectively, in the LV of Ossabaw swine fed a Western Diet compared to coronary vessels from Yucatan and Ossabaw swine without comorbidities. Species differences indicated TMPRSS2 mRNA levels increased 449.2% in the RV and 498.6% in the LV in Yucatan mini‐swine compared to coronary vessels in Ossabaw swine. A 107.3% increase in TMPRSS2 mRNA level was observed in male swine without HF compared to female intact swine with HF highlighting the importance of sex and disease state. Exercise training did not impact ACE2 or TMPRSS2 mRNA levels irrespective of tissue. In conclusion, these results suggest differences in RV, LV and coronary mRNA levels of ACE2 and TMPRSS2 are dependent upon sex and comorbidities. TMPRSS2 levels are additionally influenced by pig species and pressure‐overload. These results provide insight into how ACE2 and TMPRSS2 mRNA levels may influence the cardiovascular involvement of SARS‐COV‐2 infection in an experimental setting of pre‐clinical HF incorporating different swine species, sex, and comorbidities.