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Updated: Mar 25, 2026
Differentiation and Imaging of Brown Adipocytes from the Stromal Vascular Fraction of Interscapular Adipose Tissue from Newborn Mice
Published on: February 3, 2023
GLP-1 receptor agonist promotes brown remodelling in mouse white adipose tissue through SIRT1
Fen Xu1,2, Beisi Lin1,2, Xiaobin Zheng1,2
1Department of Endocrinology and Metabolism, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, People's Republic of China.
Aims/Hypothesis:
Accumulating evidence has revealed the significant role of glucagon-like peptide-1 (GLP-1) in weight loss. Sirtuin 1 (SIRT1) plays a vital role in the regulation of lipid metabolism. Here, we investigated the contribution of lipolytic and oxidative changes in white adipose tissue (WAT) to the weight-lowering effect induced by the GLP-1 receptor (GLP-1R) agonist exenatide (exendin-4) in mice. We also looked at the role of SIRT1 in this process.
Methods:
C57BL/6J mice and Sirt1 (+/-) mice were treated with exenatide (24 nmol/kg) or an NaCl solution (154 mmol/l) control i.p. for 8 weeks while receiving a high-fat diet (HFD) after a 12 week HFD challenge. Systemic phenotypic evaluations were carried out during and after the intervention. A lentivirus-mediated short hairpin (sh)RNA vector of the Sirt1 gene was transfected into differentiated 3T3-L1 adipocytes. An in vitro model system used adipocytes induced from Sirt1-null mouse embryonic fibroblasts (MEFs).
Results:
Exenatide reduced fat mass and enhanced the lipolytic and oxidative capacity of WAT in diet-induced obese C57BL/6J mice. However, these effects were significantly impaired in Sirt1 (+/-) mice compared with wild-type controls. In vitro, exendin-4 increased lipolysis and fatty acid oxidation by upregulating SIRT1 expression and activity in differentiated 3T3-L1 adipocytes. Conversely, RNA interference (i)-induced knockdown of SIRT1 attenuated the lipolytic and oxidative responses to exendin-4 in differentiated 3T3-L1 adipocytes. Again, these responses were entirely abolished in Sirt1-null MEFs after induction into adipocytes.
Conclusions/Interpretation:
These data highlight that a GLP-1R agonist promotes brown remodelling of WAT in a SIRT1-dependent manner; this might be one of the mechanisms underlying its effect on weight loss.
