Evaluation of biomolecular mechanisms of methylmercury toxicity and its interaction with selenium in Amazon riverside communities

• Grant number: 23/12796-6
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: March 01, 2024
• End date: October 12, 2026
• Field of knowledge: Biological Sciences - Pharmacology - Toxicology
• Principal Investigator: Fernando Barbosa Júnior
• Grantee: Gabriel Neves Cezarette
• Host Institution: Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 18/24069-3 - ReSEARCH: Recognizing Signatures of the Exposome to Anticipate the Risks for a Continuous Health, AP.TEM

Abstract

Mercury (Hg) is a toxic metal, found naturally in the environment in three basic forms: elemental (Hg0), inorganic (i-Hg) and organic (o-Hg). Among this group of compounds, methylmercury (MeHg) stands out for its greater potential for penetration through membranes and efficiency in bioaccumulation, being the largest target of toxicological evaluations. Although several studies demonstrate the toxic effects of MeHg, its mechanisms of toxicity and its relationship to biological detoxification factors lack details at the molecular level. Selenium (Se) is an essential micronutrient that acts as a key component of several antioxidant mechanisms, presents several reports of protective effect against the toxicity of MeHg. In this context, the Amazonian population is a highlight for the understanding of the interaction Se/Hg. Its nutritional singularities are considered the main factor of exposure to Hg, but it also differs from populations exposed to Hg worldwide, because it is rich in foods with high levels of Se. Given the relevance of MeHg in the development of several chronic diseases and their environmental and human health impacts, the present study proposes the characterization of the exposure of Amazonian riverine populations to MeHg, through molecular speciation and isotopic tracking, and in an innovative way, will perform the first proteomic analysis in adult individuals exposed to this toxicant. It is expected that these results will contribute beyond the understanding of the biomolecular mechanisms of MeHg and its interaction with Se, with the identification of new biomarkers of its chronic intoxication, and provide new subsidies for public policy actions in the region.