AUTHOR=Braga-Paz Isabela , Ferreira de Araújo João Locke , Alves Hugo José , de Ávila Renata Eliane , Resende Gustavo Gomes , Teixeira Mauro Martins , de Aguiar Renato Santana , de Souza Renan Pedra , Bahia Diana 

TITLE=Negative correlation between ACE2 gene expression levels and loss of taste in a cohort of COVID-19 hospitalized patients: New clues to long-term cognitive disorders

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.905757

DOI=10.3389/fcimb.2022.905757

ISSN=2235-2988

ABSTRACT=<p>In early 2020, one of the most prevalent symptoms of SARS-CoV-2 infection was the loss of smell (anosmia), found in 60-70% of all cases. Anosmia used to occur early, concomitantly with other symptoms, and often persisted after recovery for an extended period, sometimes for months. In addition to smell disturbance, COVID-19 has also been associated with loss of taste (ageusia). The latest research suggests that SARS-CoV-2 could spread from the respiratory system to the brain through receptors in sustentacular cells localized to the olfactory epithelium. The virus invades human cells <italic>via</italic> the obligatory receptor, angiotensin-converting enzyme II (ACE2), and a priming protease, TMPRSS2, facilitating viral penetration. There is an abundant expression of both <italic>ACE2</italic> and <italic>TMPRSS2</italic> in sustentacular cells. In this study, we evaluated 102 COVID-19 hospitalized patients, of which 17.60% presented anosmia and 9.80% ageusia. <italic>ACE1</italic>, <italic>ACE2</italic>, and <italic>TMPRSS2</italic> gene expression levels in nasopharyngeal tissue were obtained by RT-qPCR and measured using ΔCT analysis. ACE1 <italic>Alu</italic>287bp association was also evaluated. Logistic regression models were generated to estimate the effects of variables on ageusia and anosmia Association of <italic>ACE2</italic> expression levels with ageusia. was observed (OR: 1.35; 95% CI: 1.098-1.775); however, no association was observed between <italic>TMPRSS2</italic> and <italic>ACE1</italic> expression levels and ageusia. No association was observed among the three genes and anosmia, and the <italic>Alu</italic>287bp  polymorphism was not associated with any of the outcomes. Lastly, we discuss whetherthere is a bridge linking these initial symptoms, including molecular factors, to long-term COVID-19 health consequences   such as cognitive dysfunctions.</p>