Search

Thermogenic adipocytes, including brown and beige adipocytes, are capable of dissipating energy via heat production in response to external stimuli, such as cold exposure and exercise. This distinct feature makes them promising targets for therapy of obesity and related metabolic disease. In most mammals, the thermogenic function relies on uncoupling protein 1 (UCP1), which creates a proton leak across the inner mitochondrial membrane, diverting protons away from ATP synthesis and resulting in heat dissipation. However, that is not the case in pigs. Accumulating evidence suggested that in pigs neither functional UCP1 nor brown adipocytes were identified, which might be the leading cause for cold stress-caused neonatal mortality and greater adiposity. In our previous study, beige adipocyte formation was found in cold-tolerant pig breeds, together with the finding that UCP1 knock-in improved thermoregulatory ability and decreased fat deposition in pigs, suggesting the potential application of beige induction in pigs for both agricultural purpose and biomedical implication. In this context, we review the anatomical features, developmental origins, plasticity, transcriptional regulation, and the metabolic benefits of thermogenic adipocytes. Particularly, we describe the contribution of beige adipocytes and reconstitution of UCP1 to improve cold sensitivity and decrease fat deposition in pigs. Furthermore, future undertaking regarding beige adipocyte formation in pigs and its potential application is also discussed.

Beige adipocytes are a distinct type of fat cells with a thermogenic activity that have gained substantial attention as an alternative cellular anti-obesity target in humans. These cells may provide an alternative strategy for the genetic selection of pigs with reduced fat deposition. Despite the presence of beige adipocytes in piglets, the molecular signatures of porcine beige adipocytes remain unclear. Here, white and beige adipocytes from Tibetan piglets were primarily cultured and differentiated. Compared to the white adipocytes, the beige adipocytes exhibited a stronger thermogenic capacity. RNA-sequencing-based genome-wide comparative analyses revealed distinct gene expression profiles for white and beige adipocytes. In addition, two genes, integrin alpha-2 (ITGA2) and calponin 1 (CNN1), which were specifically differentially expressed in porcine beige adipocytes, were further functionally characterized using a loss-of-function approach. Our data showed that both genes were involved in differentiation and thermogenesis of porcine beige adipocytes. Collectively, these data furthered our understanding of gene expression in porcine white and beige adipocytes. Elucidating the genetic basis of beige adipogenesis in pigs will pave the way for molecular design breeding in both pigs and large animal models of human diseases.