Dietary regulation of fat oxidative gene expression in different skeletal muscle fiber types.
OBJECTIVE
To determine the effect of a high-fat diet on the expression of genes important for fat oxidation, the protein abundance of the transcription factors peroxisome proliferator-activated receptor (PPAR) isoforms alpha and gamma, and selected enzyme activities in type I and II skeletal muscle.


METHODS
Sprague-Dawley rats consumed either a high-fat (HF: 78% energy, n = 8) or high-carbohydrate (64% energy, n = 8) diet for 8 weeks while remaining sedentary.


RESULTS
The expression of genes important for fat oxidation tended to increase in both type I (soleus) and type II (extensor digitorum longus) fiber types after an HF dietary intervention. However, the expression of muscle type carnitine palmitoyltransferase I was not increased in extensor digitorum longus. Analysis of the gene expression of both peroxisome proliferator-activated receptor-gamma coactivator and fork-head transcription factor O1 demonstrated no alteration in response to the HF diet. Similarly, PPARalpha and PPARgamma protein levels were also not altered by the HF diet.


CONCLUSIONS
An HF diet increased the expression of an array of genes involved in lipid metabolism, with only subtle differences evident in the response within differing skeletal muscle fiber types. Despite changes in gene expression, there were no effects of diet on peroxisome proliferator-activated receptor-gamma coactivator and fork-head transcription factor O1 mRNA and the protein abundance of PPARalpha and PPARgamma.
McAinch
Andrew J
AJ
School of Health Sciences, Deakin University, Burwood, Victoria, Australia.
Lee
Jong-Sam
JS
Bruce
Clinton R
CR
Tunstall
Rebecca J
RJ
Hawley
John A
JA
Cameron-Smith
David
D
D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D018955:CD36 Antigens / Q000235:genetics / Q000378:metabolism; D002334:Carnitine O-Palmitoyltransferase / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins; D004041:Dietary Fats / Q000378:metabolism* / Q000494:pharmacology*; D005260:Female; D051858:Forkhead Transcription Factors; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D018482:Muscle, Skeletal / Q000201:enzymology / Q000378:metabolism / Q000502:physiology*; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D020033:Protein Isoforms; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D000071161:Forkhead Box Protein O1
D015094:3-Hydroxyacyl CoA Dehydrogenases; D018955:CD36 Antigens; D002334:Carnitine O-Palmitoyltransferase; D004268:DNA-Binding Proteins; D004041:Dietary Fats; D051858:Forkhead Transcription Factors; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D020033:Protein Isoforms; D011494:Protein Kinases; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors; C074639:Foxo1 protein, rat; D000071161:Forkhead Box Protein O1; C403287:pyruvate dehydrogenase kinase 4