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Isoform-specific functions of PPARγ in gene regulation and metabolism

Authors :
Wenxiang Hu
Chunjie Jiang
Mindy Kim
Yang Xiao
Hannah J. Richter
Dongyin Guan
Kun Zhu
Brianna M. Krusen
Arielle N. Roberts
Jessica Miller
David J. Steger
Mitchell A. Lazar
Source :
Genes & Development. 36:300-312
Publication Year :
2022
Publisher :
Cold Spring Harbor Laboratory, 2022.

Abstract

Peroxisome proliferator-activated receptor γ (PPARγ) is a nuclear receptor that is a vital regulator of adipogenesis, insulin sensitivity, and lipid metabolism. Activation of PPARγ by antidiabetic thiazolidinediones (TZD) reverses insulin resistance but also leads to weight gain that limits the use of these drugs. There are two main PPARγ isoforms, but the specific functions of each are not established. Here we generated mouse lines in which endogenous PPARγ1 and PPARγ2 were epitope-tagged to interrogate isoform-specific genomic binding, and mice deficient in either PPARγ1 or PPARγ2 to assess isoform-specific gene regulation. Strikingly, although PPARγ1 and PPARγ2 contain identical DNA binding domains, we uncovered isoform-specific genomic binding sites in addition to shared sites. Moreover, PPARγ1 and PPARγ2 regulated a different set of genes in adipose tissue depots, suggesting distinct roles in adipocyte biology. Indeed, mice with selective deficiency of PPARγ1 maintained body temperature better than wild-type or PPARγ2-deficient mice. Most remarkably, although TZD treatment improved glucose tolerance in mice lacking either PPARγ1 or PPARγ2, the PPARγ1-deficient mice were protected from TZD-induced body weight gain compared with PPARγ2-deficient mice. Thus, PPARγ isoforms have specific and separable metabolic functions that may be targeted to improve therapy for insulin resistance and diabetes.

Details

ISSN :
15495477 and 08909369
Volume :
36
Database :
OpenAIRE
Journal :
Genes & Development
Accession number :
edsair.doi.dedup.....352e9a6de201ff2c31a5937ff6784307
Full Text :
https://doi.org/10.1101/gad.349232.121