AdipoR2 enhances adipocyte thermogenesis in Tibetan pigs via AMPK-ACC signaling

Abstract

Previous studies have demonstrated that the adiponectin receptor 2 (AdipoR2) gene is significantly upregulated in the subcutaneous inguinal adipose tissue of cold-resistant Tibetan pigs compared to cold-sensitive Landrace pigs under long-term cold exposure. Adiponectin interacts with its receptors on adipocyte membranes, initiating a signaling cascade that promotes thermogenesis. However, the specific role of AdipoR2 in thermogenesis within Tibetan pig adipocytes remains unclear. This study investigates the effects of AdipoR2 overexpression on glucose and lipid metabolism, as well as thermogenesis, in Tibetan pig adipocytes. Subcutaneous inguinal fat tissue was collected from 2-week-old Tibetan piglets, and preadipocytes were isolated through enzymatic digestion. The pcDNA3.1-AdipoR2 overexpression plasmid was transfected into these cells, and transfection efficiency was assessed using RT-qPCR, along with the expression of genes related to glucose and lipid metabolism. Cell proliferation was evaluated using the CCK8 assay, while Western blot (WB) was employed to detect the phosphorylation of AMPK and ACC. Adipogenic differentiation capacity was assessed via Oil Red O staining, mitochondrial membrane potential was measured using JC-1 staining, and ATP production was quantified using ATP generation reagents. The results demonstrate that AdipoR2 overexpression activates the AMPK-ACC signaling pathway, leading to increased expression of glycolysis and lipolysis genes, concomitant with reduced adipogenic differentiation ability, enhanced mitochondrial respiration and ATP synthesis, and elevated thermogenesis in Tibetan pig preadipocytes. These findings provide a theoretical foundation for further exploration of the role of AdipoR2 in thermogenesis and its potential applications in improving cold adaptation in Tibetan pigs.