title: Higher levels of ATGL are associated with exercise-induced enhancement of lipolysis in rat epididymal adipocytes.
abstract: BACKGROUND
  In adipose cells, adipose triglyceride lipase (ATGL) catalyzes the first step in adipocyte triacylglyceride hydrolysis, thereby regulating both basal and hormone-stimulated lipolysis. However, little is known about the molecular mechanism(s) underlying habitual exercise-induced adaptive modulation of ATGL in white adipocytes via alteration in transcription regulator and lipolytic cofactors.
  Male Wistar rats were randomly divided into 2 groups a sedentary control group (CG) and a habitual exercise group (EG). The EG was subjected to running on a treadmill set at 5 days per week for 9 weeks. The CG was not subjected to running on a treadmill. In the EG, levels of ATGL mRNA and protein were elevated with a significant increase in lipolysis compared with the CG, accompanied by a significant increase in associations of CGI-58 with ATGL protein. Under these conditions, an upregulation of peroxisome proliferation-activated receptorg-2 (PPARg-2) was observed. In the EG, the addition of rosiglitazone further significantly increased the levels of ATGL protein compared with the CG. However, attenuated levels of the ATGL protein in adipocytes were obtained by the addition of insulin, which is known to inhibit the expression of ATGL, in both types of groups. Actually, levels of plasma insulin were significantly reduced in the EG compared with the CG.
  
  
  CONCLUSIONS
  These data suggest that elevated levels of ATGL are involved in the exercise-induced enhancement of lipolysis in primary adipocytes. The exact mechanism(s) underlying this phenomenon is associated, at least in part, with upregulated transcriptional activation of PPARg-2. In addition, exercise-induced lower circulation levels of insulin also correlate with habitual exercise-induced higher levels of ATGL in primary adipocytes.
authors: Department of Molecular Predictive Medicine and Sport Science, Kyorin University, School of Medicine, Tokyo, Japan. junetsu@ks.kyorin-u.ac.jp
authors: Junetsu
authors: J
authors: Ogasawara
authors: Takuya
authors: T
authors: Sakurai
authors: Takako
authors: T
authors: Kizaki
authors: Yoshinaga
authors: Y
authors: Ishibashi
authors: Tetsuya
authors: T
authors: Izawa
authors: Yoshikazu
authors: Y
authors: Sumitani
authors: Hitoshi
authors: H
authors: Ishida
authors: Zsolt
authors: Z
authors: Radak
authors: Shukoh
authors: S
authors: Haga
authors: Hideki
authors: H
authors: Ohno
mesh_terms: D000217:Acyltransferases; D017667:Adipocytes / Q000187:drug effects / Q000201:enzymology*; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002352:Carrier Proteins / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004822:Epididymis / Q000166:cytology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D007328:Insulin / Q000097:blood / Q000494:pharmacology; D008049:Lipase / Q000235:genetics / Q000378:metabolism*; D008066:Lipolysis / Q000187:drug effects; D008297:Male; D009929:Organ Size / Q000187:drug effects; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism; D000070778:Perilipin-1; D010750:Phosphoproteins / Q000378:metabolism; D010805:Physical Conditioning, Animal; D011485:Protein Binding / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D000077154:Rosiglitazone; D002787:Sterol Esterase / Q000378:metabolism; D045162:Thiazolidinediones / Q000494:pharmacology
chemical_list: C520594:Abhd5 protein, rat; D002352:Carrier Proteins; D007328:Insulin; D047495:PPAR gamma; D000070778:Perilipin-1; D010750:Phosphoproteins; D012333:RNA, Messenger; D045162:Thiazolidinediones; D000077154:Rosiglitazone; D004247:DNA; D000217:Acyltransferases; D002787:Sterol Esterase; D008049:Lipase; C571275:PNPLA2 protein, rat