title: Long-term caloric restriction up-regulates PPAR gamma co-activator 1 alpha (PGC-1alpha) expression in mice.
abstract: The peroxisome proliferator-activated receptor (PPAR) gamma co-activator 1 alpha (PGC-1alpha), a signal-sensing transcriptional co-activator in association with many nuclear receptors regulates various genes that control energy balance in animals. In this study, the effect of long-term caloric restriction (CR) (alternate days of fasting for 3 months) on the expression of PGC-1alpha protein in various tissues was investigated in mice. Western blot analyses showed positive immunoreactive PGC-1alpha (approximately 92 kDa) signal from various tissues. Heart, kidney and skeletal muscles expressed significant levels of PGC-1alpha, while a comparatively lower level was detected in the liver, small intestine and brain. The expression of PGC-1alpha was the highest and lowest in the heart and liver respectively. CR mice exhibited a significant increase in PGC-1alpha level in the heart (5.13-fold), kidney (3.57-fold), skeletal muscle (3.02-fold), liver (2.60-fold), small intestine (2.45-fold) and brain (2.05-fold), compared to normal (ad libitum) fed. The elevation in PGC-1alpha level, especially in highly oxidative tissues such as heart, kidney and skeletal muscle of CR mice might synergistically up-regulate genes that require PGC-1alpha co-activation. Taken together, the up-regulation of PGC-1alpha expression might potentially support optimal energy metabolism and biochemical adaptation, necessary for maintaining energy homeostasis during long-term CR.
authors.affiliation: Orphan receptor laboratory, Department of Biochemistry, St. Edmund's College, Shillong 793 003, India. harmitran@gmail.com
authors.forename: Harmit S
authors.initials: HS
authors.lastname: Ranhotra
mesh_terms: D000818:Animals; D031204:Caloric Restriction / Q000379:methods*; D004435:Eating / Q000502:physiology*; D008297:Male; D008657:Metabolic Clearance Rate; D051379:Mice; D008807:Mice, Inbred BALB C; D009928:Organ Specificity / Q000502:physiology; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D014018:Tissue Distribution; D015534:Trans-Activators / Q000378:metabolism*; D014157:Transcription Factors; D015854:Up-Regulation / Q000502:physiology
chemical_list: D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; C485290:Ppargc1a protein, mouse; D015534:Trans-Activators; D014157:Transcription Factors