A group from Universidade Federal do Rio de Janeiro, etc. has reported the relationship among the expression levels of ACE2, TMPRSS2, and severity of COVID-19.
https://www.nature.com/articles/s41598-021-88944-8
ACE2 and TMPRSS2 are known to be key players on SARS-CoV-2 entry into host cells. However, it is still unclear whether expression levels of these factors could reflect disease severity. The angiotensin-converting enzyme 2 (ACE2) has been described as the entry receptor for SARS-CoV-2 and the transmembrane serine protease 2 (TMPRSS2) as an important priming enzyme required during this process.
A case–control study was carried out including 213 individuals with SARS-CoV-2 infection confirmed by RT-qPCR in nasopharyngeal samples.
Expression of both genes of ACE2 and TMPRSS2 was positively correlated to age (r = 0.20; p = 0.03 and r = 0.21; p = 0.01 for ACE2 and TMPRSS2, respectively), while no association with sex was observed.
Transcription levels of ACE2 were significantly lower among cases than in controls, while similar levels of TMPRSS2 were observed in both groups. However, TMPRSS2/ACE2 ratios were significantly higher among cases than those of controls. From blog admin’s point of view, It is interesting but quite difficult to understand that the expression levels of ACE2 showed a protective effect for the infection, no significant association between the levels of TMPRSS2 and the infection, but TMPRSS2/ACE2 ratio could be a risk factor on COVID-19 severity, suggesting that other infection paths would be behind the ACE2/TMPRSS2 infection path.
