Efficacy of Aerosol Combination Therapy of 13 Cis Retinoic Acid and Captopril for Treating Covid-19 Patients Via Indirect Inhibition of Transmembrane Protease, Serine 2 (TMPRSS2)

Efficacy of Aerosol Combination Therapy of 13 Cis Retinoic Acid and Captopril for Treating Covid-19 Patients Via Indirect Inhibition of Transmembrane Protease, Serine 2 (TMPRSS2) Severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) has infected over 20,000,000 people causing over 700,000 deaths. It has no currently approved treatments.Airborne SARS-CoV-2 infections in humans initiate from the virus entering nasal and airway epithelial cells through binding to angiotensin-converting enzyme 2 (ACE2). Transmembrane protease, serine 2 (TMPRSS2), a cellular protease that activates the SARS-CoV-2 spike protein, colocalizes with ACE2 and can prime SARS-CoV-2 fusion directly at the plasma membrane. Transmembrane protease, serine 2 (TMPRSS2) is an androgen receptor signaling target gene and an androgen-regulated cell-surface serine protease expressed predominantly in prostate and lung epithelial cell. TMPRSS2 is normally expressed several folds higher in the prostate relative to any other human tissue, though the normal physiological function(s) remains unknown. A study found that dihydrotestosterone (DHT) s a potent activator of TMPRSS2.On the other hand, Feily et al noted that low-dose isotretinoin (0.5 mg/kg/day for 15-20 weeks) in PCO patients with moderate to severe nodulocystic acne resulted in significant decreases in levels of serum total testosterone, prolactin, and dihydrotestosterone A study demonstrated that 13- cis -Retinoic acid competitively and reversibly inhibits dihydrotestosterone. Therefore, we suggest that 13- cis -Retinoic acid will downregulate TMPRSS2 expression thorough temporary preventing the effect of dihydrotestosterone (DHT) on the activation of TMPRSS2 gene expression. ACE inhibitors and ARBs are commonly taken by heart patients to reduce blood pressure and to treat heart failure.Earlier studies had cautioned that this class of drugs could possibly increase the risk for the novel coronavirus, SARS-CoV-2, infection and elevate COVID-19