Influence of the metabolic profile of CD4+ T cells on testosterone-induced heart dysfunction in an experimental model of gender affirming hormone therapy

• Grant number: 22/13361-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2023
• End date: April 30, 2026
• Field of knowledge: Biological Sciences - Pharmacology - Cardiorenal Pharmacology
• Principal Investigator: Rita de Cassia Aleixo Tostes Passaglia
• Grantee: José Teles de Oliveira Neto
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 13/08216-2 - CRID - Center for Research in Inflammatory Diseases, AP.CEPID
• Associated scholarship(s): 24/05161-7 - Role of CD4+ T Cells in Testosterone-Induced Cardiac Dysfunction in an Experimental Model of Gender-Affirming Hormonal Therapy (testo-GAHT), BE.EP.DR

Abstract

Testosterone is used in the process of gender transition by transmale people and, although safe, it increases cardiovascular risk for this population. In pathophysiological contexts, testosterone exerts deleterious effects on the cardiovascular system, with pro-hypertrophic effects on the heart. Effector CD4+ T lymphocytes contribute to the cardiac remodeling process, an effect observed in different experimental models. Testosterone also interferes with cellular metabolism, increasing the activity of the glycolytic pathway. Changes in energy metabolism, especially in glycolytic metabolism, favor the differentiation of CD4+ T lymphocytes to pro-inflammatory profiles. Considering that cells of the immune system, including CD4+ T lymphocytes, are involved in cardiac dysfunction and that testosterone increases glycolytic metabolism, the hypothesis of our study is that the treatment of female mice with testosterone - an experimental hormone model - induces cardiac morphofunctional dysfunction by increased glycolytic metabolism in CD4+ T lymphocytes. We will evaluate the participation of CD4+ T lymphocytes in the inflammatory process associated with testosterone-induced cardiac dysfunction. Cardiac morphofunctional parameters will be evaluated by echocardiography and histological techniques in wild type (WT) and B and T lymphocyte-deficient [Rag1 knockout (KO)] female mice that will receive CD4+ T lymphocytes after treatment with vehicle or testosterone (48 mg.Kg- 1.week-1). Females KO for the enzyme PKM2, a key enzyme of glycolytic metabolism, specifically in CD4+ T lymphocytes (CD4CrePKM2flox/flox) will also be treated with vehicle or testosterone and submitted to an echocardiogram. In WT females, serum levels of pro-inflammatory cytokines will be measured, and the profile and location of CD4+ T lymphocytes in cardiac tissue will be evaluated by flow cytometry and confocal microscopy, respectively. The gene and protein expression of PKM2 will be evaluated in CD4+ T lymphocytes isolated from the heart tissue of WT females treated with testosterone or vehicle by RT-qPCR and Western Blot, respectively. In vitro, the influence of testosterone on the metabolism of CD4+ T lymphocytes will be evaluated using extracellular flow analysis technique (SeaHorse XFe96). The serum concentration of pro-inflammatory cytokines and the profile of CD4+ T lymphocytes from peripheral blood cells will also be evaluated in samples from transmale individuals undergoing hormoneization. (AU)