G-Protein-Coupled Receptor 120 Agonist Mitigates Steatotic and Fibrotic Features Triggered in Obese Mice by the Administration of a High-Fat and High-Carbohydrate Diet.

Abstract

Nonalcoholic fatty liver disease (NALFD) represents a complex condition ranging from simple steatosis (nonalcoholic fatty liver, NAFL) to inflammation, and fibrosis is one of the main features of nonalcoholic steatohepatitis (NASH). The pathogenesis of NAFLD is not well established but involves several factors (i.e., predisposition of genetic variants, obesity, and unhealthy lifestyle as unbalanced diets) that lead to an alteration of lipid homeostasis and consequently to an abnormal accumulation of triglycerides and other lipids in the liver parenchyma. Currently, no resolutive pharmacological treatment for NAFLD is available, and the only therapeutic approach is a healthy diet and physical exercise. In this study, we investigated the potential beneficial effect of GprA, a new synthetic agonist of G-protein-coupled receptor 120/free fatty acid receptor 4 (GPR120/FFAR4), in the progression of NAFL/NASH in mice fed for different periods (26 weeks and 30 weeks), with a high-fat (40% kcal) and high-carbohydrate diet, also called a Western-style diet (WSD). In our experimental model, the histological, protein, and transcriptomic analyses highlighted that the GprA can reduce signs of steatosis in WSD-fed mice. Furthermore, in 30 week-treated mice, GprA is also effective in the reduction of collagen deposition and fibrosis development. Altogether, our data validate the central role of FFAR4 in the context of NAFL/NASH onset and progression and reveal that GprA could represent an interesting candidate for the development of a new therapeutic approach in NAFLD treatment.