UC San Diego

Brown adipose tissue (BAT) is the most essential thermogenic organ in homeotherms. In mice, brown adipocytes like cells (beige adipocytes) appear in subcutaneous fat depot after prolonged cold exposure. Fully-functioning BAT and beige adipocytes in subcutaneous fat depot drive a sharp increase in energy expenditure. In fact, cold-elicited BAT activation and beige cell recruitment in subcutaneous adipose tissue have shown anti -obesity effect, making them a promising target for obesity treatment. Due to the practice reasons, intermittent cold exposure may be an effective approach to activate BAT and to treat obesity and type 2 diabetes. However, cold exposure is known to induce various physiological changes and therefore warrants a comprehensive study looking at the effects of cold exposure on the whole body energy homeostasis. We found that intermittent cold exposure (ICE) leads to mild adaptive hyperphagia and fat accumulation in mice. Fat accumulation was mostly observed in subcutaneous adipose tissue with increased lipogenesis genes expression. ICE also increased fat accumulation in liver. Interestingly, pair-feeding and restrain studies ruled out the causal role of hyperphagia and stress on ICE-induced fat accumulation. In conclusion, intermittent cold exposure shifts energy homeostasis favoring fat accumulation in mice, although ICE stimulates BAT activation and beige cell recruitment in inguinal fat