Effect of Angiotensin Converting Enzyme Inhibitor or Angiotensin II Receptor Blocker Treatment of Differentiated Primary Airway Epithelial Cells on Ace2 Expression and SarsCoV2 Replication

RATIONALE: SARS-CoV-2 gains entrance to airway epithelial cells (AECs) through binding of the viral spike protein to the angiotensin-converting enzyme 2 (ACE2) on the cell surface. However, ACE-2 also converts angiotensin II into angiotensin-(1-7) and counterbalances the renin-angiotensin-aldosterone system, with resultant protective effects in the cardiovascular system. Some data suggest that two common antihypertension medications (angiotensin II receptor blockers, ARBs;and angiotensin-converting-enzyme inhibitors, AECi) may increase ACE-2 expression in heart and kidney cells, fueling debate about how these widely used medications may modulate SARS-CoV2 infectivity and risk of COVID-19. Aim: Determine whether exposure of bronchial AECs to the ARB losartan or the ACEi captopril modulate expression of ACE-2 by AECs and/or SARS CoV2 replication. Methods: Primary bronchial AECs from children and adults (n=18;ages 8-75 yrs.) were differentiated ex vivo at an air-liquid interface to generate organotypic cultures. Cultures were treated with captopril (1μM) or losartan (2μM) added to basolateral media with each culture media change starting 72 hrs. before infection with SARS-CoV-2. In a biosafety level 3 (BSL-3) facility, cultures were infected with SARS-CoV-2 isolate USA-WA1/2020 at a multiplicity of infection (MOI) of 0.5. At 96 hrs. following infection, RNA and protein were isolated from cultures. SARS-CoV-2 replication in cultures was assessed with quantitative PCR, and quantified as viral copy number/ng RNA. ACE-2 expression was assessed by qPCR. Results: Neither captopril nor losartan treatment significantly changed AEC-2 expression by AECs as compared to untreated AEC cultures or SARS-CoV-2 infected AEC cultures without captopril or losartan treatment. At 96 hrs. following infection, SARS-CoV-2 copy number/ng RNA was not significantly different between untreated AEC cultures (median 1752, 95% CI 213 - 8599), cultures treated with captopril (median 448.6, 95% CI 160 - 3051), or cultures treated with lorsartan (median 640, 95% CI 127 - 1610;Kruskal-Wallis ANOVA p=0.4). Conclusion: These findings suggest that at the level of the airway epithelium neither the ACEi captopril or ARB losartan significantly modify expression of the SARS-CoV-2 entry factor ACE-2, nor does either medication effect the replication of SARS-CoV-2. This ex vivo data is reassuring and is consistent with evolving clinical data suggesting ACEi and ARB medications do not increase the risk for poor prognosis with COVID-19, and may actually reduce the risk of COVID-19 disease.