Role TNF-alpha on the cardiac generation of reactive oxygen species and on the reduction of nitric oxide bioavailability induced by chronic ethanol consumption

• Grant number: 16/11883-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2016
• End date: October 31, 2017
• Field of knowledge: Biological Sciences - Pharmacology - Cardiorenal Pharmacology
• Principal Investigator: Carlos Renato Tirapelli
• Grantee: Marcelo de Almeida Nakashima
• Host Institution: Escola de Enfermagem de Ribeirão Preto (EERP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Alcoholic cardiomyopathy is a disease caused by excessive consumption of ethanol and can lead to progressive cardiac dysfunction and heart failure. Ethanol consumption is associated with increased systemic production of pro-inflammatory cytokines such as tumor necrosis factor (TNF-alpha). TNF-alpha R1 receptors (TNFR1) induces activation of the enzyme NAD(P) H oxidase with consequent increase in the production of reactive oxygen species (ROS), such as superoxide anion (O2-), which induces lipid peroxidation, protein oxidation and the activation of intracellular pathways associated with inflammation, cardiac hypertrophy and remodeling. In addition, O2- can react with nitric oxide (NO), leading to the generation of peroxynitrite (ONOO-), a molecule with a high oxidizing capacity. In the heart, NO plays an important physiological role in controlling coronary blood flow and the contractility of the cardiac muscle, and the reduced NO bioavailability is related to myocardial necrosis and heart failure. The physiological cardiac NO production is mediated by the constitutive isoforms of the enzyme NOS: endothelial NO synthase (eNOS) and neuronal NO synthase (nNOS). The TNFR1 receptor negatively modulates the activity of eNOS and its activation by TNF-alpha is associated with reduced bioavailability of NO. Although the relationship between ethanol consumption and increased systemic production of TNF-alpha is well established, there are no studies evaluating the mechanisms and the participation of this cytokine in the cardiac toxicity induced by ethanol consumption. Our hypothesis is that ethanol increases TNF-alpha production which, via TNFR1 receptors will promote NAD(P)H oxidase activation with consequent increase in ROS production and lipid peroxidation, and reduced bioavailability NO and NOS expression.

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)

NAKASHIMA, MARCELO A.; SILVA, CARLA B. P.; GONZAGA, NATALIA A.; SIMPLICIO, JANAINA A.; OMOTO, ANA C. M.; TIRAPELLI, LUIS F.; TANUS-SANTOS, JOSE E.; TIRAPELLI, CARLOS R.. Chronic ethanol consumption increases reactive oxygen species generation and the synthesis of pro-inflammatory proteins in the heart through TNFR1-dependent mechanisms. CYTOKINE, v. 121, SEP 2019. (14/09595-0, 16/11883-9)