Effect of short-term and long-term fasting on transcriptional regulation of metabolic genes in rat tissues.
Ninety-eight genes/ESTs with differential expressions in epididymal adipose tissue of fed and 3-day fasting (F3) rats were identified by microarray analysis. Genes for lipogenesis, glycolysis, and glucose aerobic oxidation were decreased in response to starvation. Further study was performed to investigate the expression patterns of these genes in rat tissues after short- and long-term starvations. The results of the increased expression of the pyruvate dehydrogenase kinase 4 (PDK4) gene and decreased pyruvate dehydrogenase (PDH) in rat muscle together with decreased fatty acid synthase (FAS) in rat adipose tissue after 1 day of fasting (F1) suggested from transcriptional level that glucose aerobic oxidation was down-regulated in rat muscle and synthesis of saturated fatty acids was inhibited in rat adipose tissue after short-term fasting. It was noted that the transcriptions of genes involved in the fatty acid oxidation, such as very-long-chain Acyl-CoA dehydrogenase (LCAH), Acyl-CoA oxidase (ACO), carnitine palmitoyltransferase-I (CPT-I), and carnitine-acylcarnitine translocase (CAT)L, were greatly increased in F1 rat liver, then began to decrease in F3 and 5-day fasting (F5) rat liver, combined with significantly increased serum non-esterified fatty acids (NEFA) in F1 rats and increased urea in F5 rats, suggesting that inhibition of the oxidation of lipid and not the decreased availability of these fuels may play an important role in the phase II-phase III of fasting transition in the long-term fasting rats.
Li
Rong-Ying
RY
Ruijin Hospital, Center of Molecular Medicine, Shanghai Institute of Endocrinology, State Key Laboratory of Medical Genomics, Shanghai Jiaotong University Medical School, 197 Ruijin Road II, Shanghai 200025, China.
Zhang
Qing-Hua
QH
Liu
Zhi
Z
Qiao
Jie
J
Zhao
Shuang-Xia
SX
Shao
Li
L
Xiao
Hua-Sheng
HS
Chen
Jia-Lun
JL
Chen
Ming-Dao
MD
Song
Huai-Dong
HD
D000222:Adaptation, Physiological / Q000502:physiology; D000818:Animals; D004734:Energy Metabolism / Q000502:physiology*; D005215:Fasting / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic / Q000502:physiology*
D014157:Transcription Factors