Multiple roles of PPARalpha in brown adipose tissue under constitutive and cold conditions.
Peroxisome proliferator-activated receptor alpha (PPARalpha) is a member of the nuclear receptor family, regulating fatty acid degradation in many organs. Two-dimensional SDS-PAGE of brown adipose tissue (BAT) from PPARalpha-null mice produced a higher-density spot. Proteomic analysis indicated that the protein was pyruvate dehydrogenase beta (PDHbeta). To observe PDHbeta regulation in BAT, the organ was stimulated by long-term cold exposure, and the activities of associated enzymes were investigated. Histological and biochemical analyses of BAT showed a significant decrease in the triglyceride content in wild-type mice and some degree of decrease in PPARalpha-null mice on cold exposure. Analyses of molecules related to glucose metabolism showed that the expression of PDHbeta is under PPARalpha-specific regulation, and that glucose degradation ability may decrease on cold exposure. In contrast, analyses of molecules related to fatty acid metabolism showed that numerous PPARalpha/gamma target molecules are induced on cold exposure, and that fatty acid degradation ability in wild-type mice is markedly enhanced and also increases to same degree in PPARalpha-null mice on cold exposure. Thus, this study proposes novel and multiple roles of PPARalpha in BAT.
Komatsu
Makiko
M
Department of Metabolic Regulation, Institute on Aging and Adaptation, Shinshu University Graduate School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan.
Tong
Yuhong
Y
Li
Yufeng
Y
Nakajima
Takero
T
Li
Gang
G
Hu
Rui
R
Sugiyama
Eiko
E
Kamijo
Yuji
Y
Tanaka
Naoki
N
Hara
Atsushi
A
Aoyama
Toshifumi
T
D002001:Adipose Tissue, Brown / Q000378:metabolism*; D000818:Animals; D003080:Cold Temperature; D005227:Fatty Acids / Q000378:metabolism*; D015870:Gene Expression; D005786:Gene Expression Regulation; D005947:Glucose / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D047493:PPAR alpha / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics; D030481:Pyruvate Dehydrogenase (Lipoamide) / Q000378:metabolism*; D014280:Triglycerides / Q000378:metabolism*
D005227:Fatty Acids; D047493:PPAR alpha; D014280:Triglycerides; D030481:Pyruvate Dehydrogenase (Lipoamide); D005947:Glucose