1. Academic Validation
  2. Impaired adrenergic agonist-dependent beige adipocyte induction in obese mice

Impaired adrenergic agonist-dependent beige adipocyte induction in obese mice

  • J Vet Med Sci. 2019 Jun 6;81(6):799-807. doi: 10.1292/jvms.19-0070.
Woongchul Shin 1 Yuko Okamatsu-Ogura 1 Shinya Matsuoka 1 Ayumi Tsubota 1 Kazuhiro Kimura 1
Affiliations

Affiliation

  • 1 Laboratory of Biochemistry, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido 060-0818, Japan.
Abstract

Brown adipocytes, which exist in brown adipose tissue (BAT), are activated by adrenergic stimulation, depending on the activity of uncoupling protein 1 (UCP1). Beige adipocytes emerge from white adipose tissue (WAT) in response to chronic adrenergic stimulation. We investigated obesity-related changes in responses of both types of adipocytes to adrenergic stimulation in mice. Feeding of mice with high-fat diets (HFD: 45%-kcal fat) for 14 weeks resulted in significantly higher body and WAT weight compared to feeding with normal diets (ND: 10%-kcal fat). Injection with β3-adrenergic receptor agonist CL316,243 (CL; 0.1 mg/kg, once a day) for one week elevated the mRNA and protein expression levels of UCP1 in BAT, irrespective of diet. In WAT, CL-induced UCP1 expression in ND mice; however, the responses to CL treatment were attenuated in HFD mice, indicating that CL-induced browning of WAT was impaired in obese mice. Flow cytometric analysis revealed a significant decrease in platelet-derived growth factor receptor (PDGFR) α-expressing beige adipocyte progenitors in WAT of HFD mice compared with those of ND mice. Expression of PDGF-B, a PDGFRα ligand, increased in WAT following CL-injection in ND mice, but not in HFD mice. Treatment of mice with a PDGFR Inhibitor significantly decreased CL-dependent UCP1 protein induction in WAT. Our study demonstrates that β3-adrenergic stimulation-dependent beige adipocyte induction in WAT is impaired by obesity in mice, potentially due to obesity-dependent reduction in the number of PDGFRα-expressing progenitors and decreased PDGF-B expression.

Keywords

beige adipocytes; brown adipocytes; obesity; uncoupling protein 1; β3-adrenergic receptor agonist.

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