Intermittent Cold Exposure Enhances Fat Accumulation in Mice

Abstract

Due to its high energy consuming characteristics, brown adipose tissue (BAT) has been suggested as a key player in energy metabolism. Cold exposure is a physiological activator of BAT. Intermittent cold exposure (ICE), unlike persistent exposure, is clinically feasible. The main objective of this study was to investigate whether ICE reduces adiposity in C57BL/6 mice. Surprisingly, we found that ICE actually increased adiposity despite enhancing Ucp1 expression in BAT and inducing beige adipocytes in subcutaneous white adipose tissue. ICE did not alter basal systemic insulin sensitivity, but it increased liver triglyceride content and secretion rate as well as blood triglyceride levels. Gene profiling further demonstrated that ICE, despite suppressing lipogenic gene expression in white adipose tissue and liver during cold exposure, enhanced lipogenesis between the exposure periods. Together, our results indicate that despite enhancing BAT recruitment, ICE in mice increases fat accumulation by stimulating de novo lipogenesis.

Chronic cold exposure: A white adipose tissue browning factor

“…All we knew for the patient was that he had been homeless and he died in the middle of the winter. Similar ndings occur in mice subjected to intermittent cold exposure (11).…”

Cold exposure drives weight gain and adiposity following chronic suppression of brown adipose tissue

“…In obese animals lacking BAT, there seems to be an entirely different homeostatic response to cold-stress where following BAT lipectomy, obese, cold-exposed rats gain weight and exhibit nearly a one fold increase in adipose tissue mass [20]. There is also evidence to suggest that intermittent cold-exposure (from 20°C to 4°C) over a period of days increases weight gain and adiposity and that this is associated with transient, intermittent increases in energy intake [21]. Although other mechanisms such as intestinal growth and increased fatty acid absorption [22] may also play a role the impact of BAT, lipectomy on the response to cold-exposure mirrors our own findings and would suggest a compensatory mechanism for heat production in obesity when adaptive thermogenesis is insufficient.…”

Characterization of cold‐induced remodelling reveals depot‐specific differences across and within brown and white adipose tissues in mice

“…, Yoo et al . ). Moreover, some studies reported that cold exposure enhances both glucose‐derived lipogenesis and fatty acid oxidation in BAT, but its effects on WAT were controversial (Yu et al .…”