Exercise training enhances tumor necrosis factor-alpha-induced expressions of anti-apoptotic genes without alterations in caspase-3 activity in rat epididymal adipocytes.
The effect of exercise training on tumor necrosis factor-alpha (TNF-alpha) signaling was investigated in rat epididymal adipocytes. Incubation of isolated adipocytes with TNF-alpha (20 ng/ml) for 5 h enhanced the expression of the inhibitor apoptosis protein 2 (IAP2) gene without any enhancement of caspase-3 activity in both the sedentary control (C) and exercise-trained (TR) groups. However, the ability of TNF-alpha to enhance IAP2 gene expression was significantly greater in TR than in C rats. The basal expression of the IkappaB kinase beta (IKK beta) gene and that of the BCL-x(L) gene were also higher in TR than in C rats. Mn-superoxidedismutase contents in adipocytes were higher in TR than in C rats. Moreover, no apoptotic nucleuses of adipocytes in response to acute exercise were observed in either group at least up to 5 h after exercise. Exercise training also enhanced the inhibitory effect of TNF-alpha on the gene expression of the fatty acid synthase (FAS), a lipogenic enzyme, suggesting that fatty acid synthesis may be reduced. Thus, exercise training enhanced TNF-alpha signaling directed toward the expressions of survival signals and the suppression of FAS gene expression.
Sakurai
Takuya
T
Department of Kinesiology, Graduate School of Science, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan.
Takei
Megumi
M
Ogasawara
Junetsu
J
Watanabe
Naoto
N
Sanpei
Minori
M
Yoshida
Midori
M
Nakae
Dai
D
Sakurai
Tomonobu
T
Nakano
Norihiko
N
Kizaki
Takako
T
Ohno
Hideki
H
Izawa
Tetsuya
T
D017667:Adipocytes / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D001835:Body Weight; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002478:Cells, Cultured; D004822:Epididymis / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D064429:Fatty Acid Synthases / Q000378:metabolism; D051550:I-kappa B Kinase / Q000235:genetics / Q000378:metabolism; D051034:Inhibitor of Apoptosis Proteins / Q000235:genetics / Q000378:metabolism; D050155:Lipogenesis / Q000235:genetics; D008297:Male; D051379:Mice; D010805:Physical Conditioning, Animal; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha; D051020:bcl-X Protein / Q000235:genetics / Q000378:metabolism
C494813:Bcl2l1 protein, rat; D051034:Inhibitor of Apoptosis Proteins; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D051020:bcl-X Protein; D013482:Superoxide Dismutase; D064429:Fatty Acid Synthases; D051550:I-kappa B Kinase; C505409:Casp3 protein, mouse; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases