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Updated: Jul 31, 2026

Mechanism of Regulation of Adipocyte Numbers in Adult Organisms Through Differentiation and Apoptosis Homeostasis
08:34

Mechanism of Regulation of Adipocyte Numbers in Adult Organisms Through Differentiation and Apoptosis Homeostasis

Published on: June 3, 2016

Functional role of RXRs and PPARgamma in mature adipocytes

D Metzger1, T Imai, M Jiang

  • 1Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC) INSERM/CNRS/ULP, 1, rue Laurent Fries, 67404 ILLKIRCH, France. metzger@mail-igbmc.u-strasbg.fr

Prostaglandins, Leukotrienes, and Essential Fatty Acids
|June 7, 2005
PubMed

Insights

Retinoid X receptor alpha (RXRalpha) is crucial for fat storage in adipocytes. While RXRalpha is essential for lipogenesis, RXRgamma can compensate for RXRalpha

Area of Science:

  • Metabolism and Endocrinology
  • Adipocyte Biology
  • Molecular Genetics

Background:

  • Peroxisome proliferator-activated receptor gamma (PPARgamma) is vital for adipocyte differentiation and fat storage.
  • PPARgamma forms heterodimers with retinoid X receptors (RXRs), including RXRalpha, which are present in adipose tissue.

Purpose of the Study:

  • To investigate the specific roles of RXRalpha and PPARgamma in mature adipocytes.
  • To overcome the embryonic lethality associated with complete gene ablation.

Main Methods:

  • Generation of adult adipocyte-specific knockout mice for RXRalpha (RXRalpha(ad-/-)) and PPARgamma (PPARgamma(ad-/-)).
  • Analysis of adiposity, lipogenesis, and adipocyte survival in these models under various dietary conditions.

Main Results:

  • RXRalpha(ad-/-) mice exhibit resistance to diet- and chemically-induced obesity despite normal adiposity on a regular diet.
  • Mature adipocytes lacking RXRalpha and RXRgamma, or PPARgamma, undergo cell death and are replaced by new adipocytes.
  • RXRalpha is essential for lipogenesis in adipocytes.

Conclusions:

  • RXRalpha plays a critical role in adipocyte lipogenesis and maintaining adipocyte viability.
  • RXRgamma can functionally substitute for RXRalpha in supporting essential adipocyte functions regulated by PPARgamma/RXR heterodimers.
  • Selective ablation models are crucial for studying gene functions in mature adipocytes.

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