Peroxisome proliferator-activated receptor {delta} is an essential transcriptional regulator for mitochondrial protection and biogenesis in adult heart.
BACKGROUND
Peroxisome proliferator-activated receptors (PPARs) (alpha, gamma, and delta/beta) are nuclear hormone receptors and ligand-activated transcription factors that serve as key determinants of myocardial fatty acid metabolism. Long-term cardiomyocyte-restricted PPARdelta deficiency in mice leads to depressed myocardial fatty acid oxidation, bioenergetics, and premature death with lipotoxic cardiomyopathy.


OBJECTIVE
To explore the essential role of PPARdelta in the adult heart.


RESULTS
We investigated the consequences of inducible short-term PPARdelta knockout in the adult mouse heart. In addition to a substantial transcriptional downregulation of lipid metabolic proteins, short-term PPARdelta knockout in the adult mouse heart attenuated cardiac expression of both Cu/Zn superoxide dismutase and manganese superoxide dismutase, leading to increased oxidative damage to the heart. Moreover, expression of key mitochondrial biogenesis determinants such as PPARgamma coactivator-1 were substantially decreased in the short-term PPARdelta deficient heart, concomitant with a decreased mitochondrial DNA copy number. Rates of palmitate and glucose oxidation were markedly depressed in cardiomyocytes of PPARdelta knockout hearts. Consequently, PPARdelta deficiency in the adult heart led to depressed cardiac performance and cardiac hypertrophy.


CONCLUSIONS
PPARdelta is an essential regulator of cardiac mitochondrial protection and biogenesis and PPARdelta activation can be a potential therapeutic target for cardiac disorders.
Wang
Peiyong
P
Department of Nutrition Sciences, University of Alabama at Birmingham, Webb 435, 1675 University Blvd, Birmingham, AL 35242, USA.
Liu
Jian
J
Li
Yuquan
Y
Wu
Sijie
S
Luo
Jinwen
J
Yang
Huan
H
Subbiah
Ramasamy
R
Chatham
John
J
Zhelyabovska
Olga
O
Yang
Qinglin
Q
D000375:Aging; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D006332:Cardiomegaly / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D004272:DNA, Mitochondrial / Q000378:metabolism; D004734:Energy Metabolism / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D005947:Glucose / Q000378:metabolism; D006706:Homeostasis; D050356:Lipid Metabolism / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008929:Mitochondria, Heart / Q000378:metabolism* / Q000473:pathology; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000473:pathology; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000235:genetics; D047494:PPAR delta / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D019308:Palmitic Acid / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis*; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D000072105:Superoxide Dismutase-1; D014158:Transcription, Genetic; D018487:Ventricular Dysfunction, Left / Q000235:genetics / Q000378:metabolism; D000099156:Superoxide Dismutase 2
D000975:Antioxidants; D004272:DNA, Mitochondrial; D005947:Glucose; D047494:PPAR delta; D019308:Palmitic Acid; D012333:RNA, Messenger; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D000099156:Superoxide Dismutase 2; C000606291:Sod1 protein, mouse