COLD INDUCES EXPRESSION OF GENES SPECIFIC TO THERMOGENESIS (PGC-1α, UCP1) AND BEIGE CELLS (TMEM26, SLC27A1) IN MOUSE INGUINAL WHITE ADIPOSE TISSUE

Studying adaptive thermogenic responses as being a strategy to protect against several metabolic disorders. The browning process is a crucial point of adaptive thermogenic responses. The present study was carried out to examine whether inguinal white adipose tissue (iWAT) is a candidate for the browning process. Mice were caged in a 4 °C cold chamber (Cold group) for 24 hours and 23 °C room temperature condition (RT group). The result showed that mRNA expression of genes specific to thermogenesis, including peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and uncoupling protein 1 (UCP1), was markedly upregulated in iWAT of the mice in the Cold group compared to the mice in the RT group. Consistent with this, mRNA expression of the Transmembrane protein 26 (TMEM26) gene, specific to beige cells, was also significantly higher in the iWAT of the cold exposed mice than that in the iWAT of the mice housed at room temperature. Expression of solute carrier family 27member 1 (SLC27A1) gene, another gene coding for a protein of beige cells, was tendency to increase in iWAT of the cold exposed mice compared with that in iWAT of the control mice. However, this change was not significantly differed between the two groups. These data demonstrate that iWAT is an important tissue responding to cold-induced thermogenesis and browning process. Thus, iWAT is a promising candidate for further studies on the mechanism of cold-induced thermogenic responses in white adipose tissues.