Glyphosate implications on Metabolic-associated Fatty Liver Desease in mice: role of NFR2, p65, SREBP1 transcription factors

• Grant number: 21/07954-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): October 01, 2021
• Effective date (End): December 31, 2022
• Field of knowledge: Health Sciences - Medicine - Pathological Anatomy and Clinical Pathology
• Principal Investigator: Guilherme Ribeiro Romualdo
• Grantee: Ana Carolina Sprocatti dos Santos
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

The metabolic-associated fatty liver disease (MAFLD) is closely associated with diabetes and obesity, affecting 25% of the global population. MAFLD is also related to the high intake of saturated fatty acids and simple carbohydrates. MAFLD pathogenesis involves an imbalance in hepatic lipid metabolism, increased inflammation, and oxidative stress, that is associated with deregulation of SREBP1, NF-ºB (p65), and Nrf2 transcription factors. respectively. The herbicide glyphosate (N-(phosphonomethyl) glycine) is widely used in agriculture and its residues are frequently identified in foods. This herbicide has already demonstrated hepatic pro-oxidant, lipogenic, and/or inflammatory effects in preclinical studies, at doses below the toxicological limits adopted by regulatory agencies. Thus, the project will evaluate whether the administration of the herbicide glyphosate promotes MAFLD in an in vivo nutritional model. In detail, we will evaluate the implications of this herbicide on NF-ºB (p65), Nrf2, and SREBP1 transcription factors, directly related to the pathogenesis of MAFLD. C57BL/6J male mice (n=10/group) will receive a high-fat diet (30% lard and 0.2% cholesterol), containing 20% sucrose and high sugar solution (23.1 g/L of fructose and 18.9 g/L of glucose) for 6 months. Concomitantly, the animals will receive glyphosate [0.05, 5 or 50 mg/kg/day by gavage (5x/week)]. The doses were based on the Acceptable Daily Intake (ADI) or the No Observed Adverse Effect Level (NOAEL) values from European/American regulatory agencies. The glucose tolerance test will be calculated (after 3 and 6 months) and serum will be sampled for biochemical analysis (alanine aminotransferase, triglycerides, and cholesterol). Liver samples will be collected for histological analysis, including MAFLD grade (H&E), collagen (Sirius red) and lipid (Oil red) morphometry, and immunohistochemistry for Ki-67 (i.e., proliferation), CD68 (i.e., macrophage marker), and ±-SMA (i.e., active stellate cell marker). Other liver samples will be obtained for immunoblotting (p65, Nrf2, and SREBP1) the determination lipid hydroperoxide levels, catalase, superoxide dismutase, glutathione peroxidase, and glutathione-S transferase activities. (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)

ROMUALDO, GUILHERME R.; VALENTE, LETICIA CARDOSO; SPROCATTI, ANA CAROLINA; BACIL, GABRIEL PRATA; DE SOUZA, ISADORA PENEDO; RODRIGUES, JOSIAS; RODRIGUES, MARIA APARECIDA MARCHESAN; VINKEN, MATHIEU; COGLIATI, BRUNO; BARBISAN, LUIS FERNANDO. Western diet-induced mouse model of non-alcoholic fatty liver disease associated with metabolic outcomes: Features of gut microbiome-liver-adipose tissue axis. NUTRITION, v. 103-104, p. 12-pg., 2022-10-03. (21/07954-6, 20/00377-0, 20/01078-7)