title: The role of prolyl hydroxylase domain protein (PHD) during rosiglitazone-induced adipocyte differentiation.
abstract: Rosiglitazone, a well known insulin sensitizer, stimulates adipocyte differentiation via the activation of peroxisome proliferator-activated receptor γ (PPARγ). Previous two-dimensional proteomics studies using C3H10T1/2 murine mesenchymal pluripotent stem cells revealed that prolyl hydroxylase domain protein (PHD) levels significantly increased during rosiglitazone-induced adipocyte differentiation (RIAD). In this study, we investigated the functional role played by PHD during RIAD. Three PHD isoforms (PHD1, 2, and 3) were found to be up-regulated in C3H10T1/2 cells during RIAD, whereas PHD knockdown and treatment with PHD inhibitors (dimethyloxalyl glycine or ethyl-3,4-dihydroxybenzoate) blocked RIAD. PHD inhibition was found to be associated with increases in the levels of anti-adipogenic proteins such as GATA-3, KLF-2, and transcriptional coactivator with PDZ binding motif (TAZ), with their reduced ubiquitination, suggesting that PHDs evoke the ubiquitination/proteasomal degradation of anti-adipogenic proteins. On the other hand, MG-132 (a proteasomal inhibitor) prevented the degradation of anti-adipogenic proteins and retarded RIAD. PPARγ antagonists (bisphenol A diglycidyl ether or GW9662) blunted the effects of rosiglitazone on PHD regulation. Furthermore, putative PPARγ binding sites were identified in the promoter region of PHDs by ChIP-PCR, implying that rosiglitazone may induce PHD up-regulation directly by PPARγ activation. Consistent with in vitro results, oral administration of rosiglitazone to ob/ob mice for 2 weeks increased adipose PHD levels and decreased anti-adipogenic protein levels by increasing their ubiquitination. These results suggest that rosiglitazone increases PHD expression in a PPARγ-dependent manner and that this leads to the commitment of anti-adipogenic proteins to the ubiquitination-proteasomal pathway and to the subsequent induction of adipocyte differentiation.
authors: From the Department of Pharmacology School of Medicine and.
authors: Juyoung
authors: J
authors: Kim
authors: Hyun Jeong
authors: HJ
authors: Kwak
authors: Ji-Young
authors: JY
authors: Cha
authors: Yun-Seung
authors: YS
authors: Jeong
authors: Sang Dahl
authors: SD
authors: Rhee
authors: Hyae Gyeong
authors: HG
authors: Cheon
mesh_terms: D000217:Acyltransferases; D017667:Adipocytes / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D005260:Female; D050990:GATA3 Transcription Factor / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000494:pharmacology; D051741:Kruppel-Like Transcription Factors / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008820:Mice, Obese; D047495:PPAR gamma / Q000378:metabolism; D011393:Procollagen-Proline Dioxygenase / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000502:physiology; D040901:Proteomics; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000494:pharmacology*; D014157:Transcription Factors / Q000378:metabolism; D054875:Ubiquitination / Q000187:drug effects / Q000502:physiology
chemical_list: D050990:GATA3 Transcription Factor; C494748:Gata3 protein, mouse; D007004:Hypoglycemic Agents; C498314:Klf2 protein, mouse; D051741:Kruppel-Like Transcription Factors; D047495:PPAR gamma; D045162:Thiazolidinediones; D014157:Transcription Factors; D000077154:Rosiglitazone; C522721:PHD1 protein, mouse; D011393:Procollagen-Proline Dioxygenase; D000217:Acyltransferases; C486363:tafazzin protein, mouse
keywords: Adipocyte; Adipocyte Differentiation; Adipogenesis; Diabetes; GATA-3; Krüppel-like Factor (KLF); PHD; PPARγ; Peroxisome Proliferator-activated Receptor (PPAR); Rosiglitazone