Surface receptors for SARS-CoV-2 cellular entry in oral cavity tissues and salivary glands: autopsies from COVID-19 cases

• Grant number: 21/03004-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2021
• End date: July 31, 2022
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Paulo Henrique Braz da Silva
• Grantee: Italo Tomonari Kano
• Host Institution: Faculdade de Odontologia (FO). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The first interaction between the SARS-CoV-2 and the human cells occurs between the protein S of the viral capside and the ACE2 receptors, the main targets being the organs and tissues that contain these receptors. Protein S cleavage is mediated by a host protease and is crucial to the infection process. Even a high expression of ACE2, successful cell entry by SARS-CoV-2 cannot be guaranteed if the expression levels of these proteases vary. It is known that high levels of ACE2, and proteases, such as TMPRSS2 and furin, result in an exacerbation of the clinical symptoms of SARS-CoV-2. Thus, the objective of this work is, therefore, to compare the expression of ACE2, furin and TMPRSS2 surface receptors in oral tissue autopsies of patients who died of COVID-19. For this, 60 samples of different samples of the oral cavity will be used, being the buccal mucosa, gingiva, lateral border of the tongue, taste buds and major salivary glands (parotid and submandibular) and minor salivary glands (lower lip) through a minimally invasive autopsy guided by ultrasound. For the analyzes, immunohistochemistry will be used to evaluate the expression of the following primary antibodies, in specific dilutions, anti-TMPRSS2 (1: 1,000), anti-furin (1: 500 and anti-ACE2 (1: 200) using the ImageJ software (Image Processing and Analysis in Java), and qRT-PCR will be used for gene expression analysis using specific primers corresponding to each of the genes, a specific correlation test will be used. For all tests, a 95% significance level will be considered. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SCHWAB, GABRIELA; PALMIERI, MICHELLE; ZERBINATI, RODRIGO M.; SARMENTO, DMITRY J. S.; REIS, THAIS; ORTEGA, KAREM L.; KANO, ITALO T.; CAIXETA, RAFAEL A., V; HASSEUS, BENGT; SAPKOTA, DIPAK; et al. Lack of direct association between oral mucosal lesions and SARS-CoV-2 in a cohort of patients hospitalised with COVID-19. JOURNAL OF ORAL MICROBIOLOGY, v. 14, n. 1, p. 9-pg., 2022-12-31. (21/03004-3, 21/07490-0)