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PPAR Research
Volume 2011, Article ID 372854, 13 pages
Research Article

Cardiomyocyte-Restricted Deletion of PPARβ/δ in PPARα-Null Mice Causes Impaired Mitochondrial Biogenesis and Defense, but No Further Depression of Myocardial Fatty Acid Oxidation

1Department of Nutrition Sciences, University of Alabama at Birmingham, 1675 University Boulevard, Birmingham, AL 35294-3360, USA
2Department of Anatomy, Second Military Medical University, Shanghai 200433, China
3Department of Cardio Thoracic Surgery, Hunan Children’s Hospital, Changsha 410007, China
4Division of Cardiology, Department of Medicine, Emory University, Atlanta, GA 30322, USA
5Department of Anatomy, Morehouse School of Medicine, Atlanta, GA 30310, USA
6Department of Pathology, Emory University, Atlanta, GA 30322, USA

Received 30 April 2011; Revised 27 June 2011; Accepted 28 June 2011

Academic Editor: Brian Finck

Copyright © 2011 Jian Liu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


It is well documented that PPARα and PPARβ/δ share overlapping functions in regulating myocardial lipid metabolism. However, previous studies demonstrated that cardiomyocyte-restricted PPARβ/δ deficiency in mice leads to severe cardiac pathological development, whereas global PPARα knockout shows a benign cardiac phenotype. It is unknown whether a PPARα-null background would alter the pathological development in mice with cardiomyocyte-restricted PPARβ/δ deficiency. In the present study, a mouse model with long-term PPARβ/δ deficiency in PPARα-null background showed a comparably reduced cardiac expression of lipid metabolism to those of single PPAR-deficient mouse models. The PPARα-null background did not rescue or aggravate the cardiac pathological development linked to cardiomyocyte-restricted PPARβ/δ deficiency. Moreover, PPARα-null did not alter the phenotypic development in adult mice with the short-term deletion of PPARβ/δ in their hearts, which showed mitochondrial abnormalities, depressed cardiac performance, and cardiac hypertrophy with attenuated expression of key factors in mitochondrial biogenesis and defense. The present study demonstrates that cardiomyocyte-restricted deletion of PPARβ/δ in PPARα-null mice causes impaired mitochondrial biogenesis and defense, but no further depression of fatty acid oxidation. Therefore, PPARβ/δ is essential for maintaining mitochondrial biogenesis and defense in cardiomyocytes independent of PPARα.