Kirenol inhibits adipogenesis through activation of the Wnt/β-catenin signaling pathway in 3T3-L1 adipocytes

Biochem Biophys Res Commun. 2014 Mar 7;445(2):433-8. doi: 10.1016/j.bbrc.2014.02.017. Epub 2014 Feb 12.

Abstract

Kirenol, a natural diterpenoid compound, has been reported to possess anti-oxidant, anti-inflammatory, anti-allergic, and anti-arthritic activities; however, its anti-adipogenic effect remains to be studied. The present study evaluated the effect of kirenol on anti-adipogenesis through the activation of the Wnt/β-catenin signaling pathway. Kirenol prevented intracellular lipid accumulation by down-regulating key adipogenesis transcription factors [peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding proteins α (C/EBPα), and sterol regulatory element binding protein-1c (SREBP-1c)] and lipid biosynthesis-related enzymes [fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC)], as well as adipocytokines (adiponectin and leptin). Kirenol effectively activated the Wnt/β-catenin signaling pathway, in which kirenol up-regulated the expression of low density lipoprotein receptor related protein 6 (LRP6), disheveled 2 (DVL2), β-catenin, and cyclin D1 (CCND1), while it inactivated glycogen synthase kinase 3β (GSK3β) by increasing its phosphorylation. Kirenol down-regulated the expression levels of PPARγ and C/EBPα, which were up-regulated by siRNA knockdown of β-catenin. Overall, kirenol is capable of inhibiting the differentiation and lipogenesis of 3T3-L1 adipocytes through the activation of the Wnt/β-catenin signaling pathway, suggesting its potential as natural anti-obesity agent.

Keywords: Adipogenesis; Kirenol; Wnt/β-catenin.

MeSH terms

  • 3T3-L1 Cells
  • Adipocytes / cytology
  • Adipocytes / drug effects*
  • Adipocytes / metabolism
  • Adipogenesis / drug effects*
  • Animals
  • Anti-Inflammatory Agents / pharmacology*
  • Anti-Obesity Agents / pharmacology
  • CCAAT-Enhancer-Binding Protein-alpha / genetics
  • Diterpenes / pharmacology*
  • Down-Regulation / drug effects
  • Lipid Metabolism / drug effects
  • Mice
  • PPAR gamma / genetics
  • RNA Interference
  • Sterol Regulatory Element Binding Protein 1 / genetics
  • Wnt Signaling Pathway / drug effects*
  • beta Catenin / genetics
  • beta Catenin / metabolism

Substances

  • Anti-Inflammatory Agents
  • Anti-Obesity Agents
  • CCAAT-Enhancer-Binding Protein-alpha
  • Diterpenes
  • PPAR gamma
  • Sterol Regulatory Element Binding Protein 1
  • beta Catenin
  • kirenol