Muscle cells affect the promoting effect of FGF21 on lipid accumulation in porcine adipocytes through AhR/FGFR1 signaling pathway

Abstract

The intramuscular fat (IMF) content, as an important meat quality trait, can directly affect the tenderness, juiciness, and flavor of pork. Reasonably increasing the IMF content can improve the palatability of pork. Therefore, identification of important factors for the lipid accumulation among muscles is the breakthrough point for improving meat quality. FGF21, identified as a novel metabolic regulator, has been found to regulate glucose and lipid metabolism in 3T3-L1 adipocytes, but its function in porcine adipocytes remains unclear. In this study, we discovered that the administration of recombinant FGF21 protein promotes adipogenic differentiation and increases triglyceride accumulation in porcine adipocytes. While the expression of FGFR1 in adipocytes under muscle conditions is inhibited, affecting the signal transduction of FGF21. This inhibitory effect is accompanied by activation of the AhR signaling pathway. When treated with the AhR antagonist CH223191, there was a partial restoration of FGFR1 expression levels. This indicates that muscle cells suppress the expression of FGFR1 in adipocytes by activating the AhR signaling pathway, thereby affecting the signal transduction of FGF21. Our results reveal the regulatory role of FGF21 in pig adipocyte differentiation and the regulatory mechanism of muscle environment on FGFR1 expression, providing new theoretical basis for IMF content improvement from the perspective of FGF21-FGFR1 signaling transduction.