Nicotinamide enhances lipid deposition and thermogenesis in goat brown adipocytes

Brown adipose tissue (BAT) serves as a crucial thermogenic tissue in newborn goats, playing an important role in maintaining their core body temperature through adaptive thermogenesis. Initially, we found that nicotinamide (NAM) content was significantly higher in BAT (0.047 μg/g, n = 6 biological replicates) than that in white adipose tissue (WAT, 0.021 μg/g, n = 6 biological replicates). However, the effect of NAM on goat brown adipocytes remains unknown. The experimental results revealed that NAM enhanced lipid deposition, mitochondrial DNA content and the expression of uncoupling protein 1 (UCP1) in brown adipocytes. Here, 20 μM isoproterenol (ISO), a non-selective agonist for β-adrenergic receptors (β-ARs), was used to simulate cold exposure in brown adipocytes. We found that 2 mM NAM treatment significantly elevated lipid deposition and amplified thermogenesis of brown adipocytes under ISO-induced cold conditions. Furthermore, we found that NAM enhanced UCP1 promoter activity involving the EBF2 binding site, suggesting potential involvement of EBF2 in promoting UCP1 expression and thermogenesis in brown adipocytes. These findings offer new insights into nutritional strategies for enhancing BAT thermogenesis with NAM in goats.