Peroxisome Proliferator-activated Receptor (PPAR)-2 Controls Adipocyte Differentiation and Adipose Tissue Function through the Regulation of the Activity of the Retinoid X Receptor/PPARγ Heterodimer

Péter Bai,Sander M Houten,Aline Huber,Valérie Schreiber,Mitsuhiro Watanabe,Borbála Kiss,Gilbert De Murcia,Johan Auwerx,Josiane Ménissier-De Murcia

doi:10.1074/jbc.m701021200

Abstract

Peroxisome Proliferator-activated Receptor (PPAR)-2 Controls Adipocyte Differentiation and Adipose Tissue Function through the Regulation of the Activity of the Retinoid X Receptor/PPARγ Heterodimer

Highlights

Adipose tissue is composed of adipocytes that store energy in the form of triglycerides
In this report we show that poly(ADP-ribose) polymerase-2 (PARP-2), known as an enzyme participating in the surveillance of the genome integrity, is a member of the PPAR␥/ retinoid X receptor (RXR) transcription machinery
In Vivo Dysfunction of the PPAR␥/RXR Heterodimer in the white adipose tissue (WAT) of PARP-2Ϫ/Ϫ Mice—The different fat depots and the interscapular brown adipose tissue-associated WAT were measured in 7-month-old PARP-2Ϫ/Ϫ mice and their wild-type littermates

Summary

EXPERIMENTAL PROCEDURES

Materials—All chemicals were from Sigma-Aldrich unless stated otherwise. Animals—PARP-2Ϫ/Ϫ mice and their wild-type (WT) littermates [26] coming from heterozygous crossings were used. Cells were differentiated in DMEM, 10% newborn calf serum, 5 ␮M troglitazone, 5 ␮M dexamethasone, 500 ␮M isobutylmethylxanthine, and 10 ␮g/ml insulin (later defined as differentiation mix), while the control cells received DMEM, 10% fetal calf serum, and Me2SO as vehicle. Control cells after confluency were cultured in DMEM plus 10% fetal calf serum containing only vehicle (Me2SO, 0.21%). Luciferase Activity Measurement—3 ϫ 105 HEK cells were seeded in 6-well plates and were transfected with pSupersiPARP-2, pSuper-scrPARP-2, pBabe, or pBabe-PARP-2 using the BES-buffered saline method. Cells were transfected 24 h later with 0.6 ␮g of pSuper-siPARP2/pSuper-scrPARP-2/pBabe/pBabe-PARP-2, 0.4 ␮g of ␤-galactosidase expression plasmid, 1 ␮g of pSG-PPAR␣/pSGPPAR␤/pSG-PPAR␥2/pCMX-ER␤ expression vector, and 1 ␮g of PPAR-/ER-responsive construct. For the determination of PPAR activity, just before transfection, cells were washed in serum-free DMEM medium, and the transfection was carried out in DMEM plus 10% fat-free serum. Chromatin Immunoprecipitation—Chromatin immunoprecipitation was performed according to a previous study [33] on TABLE 3

Chip primers

RESULTS

DISCUSSION