title: Cardiac metabolic pathways affected in the mouse model of barth syndrome.
abstract: Cardiolipin (CL) is a mitochondrial phospholipid essential for electron transport chain (ETC) integrity. CL-deficiency in humans is caused by mutations in the tafazzin (Taz) gene and results in a multisystem pediatric disorder, Barth syndrome (BTHS). It has been reported that tafazzin deficiency destabilizes mitochondrial respiratory chain complexes and affects supercomplex assembly. The aim of this study was to investigate the impact of Taz-knockdown on the mitochondrial proteomic landscape and metabolic processes, such as stability of respiratory chain supercomplexes and their interactions with fatty acid oxidation enzymes in cardiac muscle. Proteomic analysis demonstrated reduction of several polypeptides of the mitochondrial respiratory chain, including Rieske and cytochrome c1 subunits of complex III, NADH dehydrogenase alpha subunit 5 of complex I and the catalytic core-forming subunit of F0F1-ATP synthase. Taz gene knockdown resulted in upregulation of enzymes of folate and amino acid metabolic pathways in heart mitochondria, demonstrating that Taz-deficiency causes substantive metabolic remodeling in cardiac muscle. Mitochondrial respiratory chain supercomplexes are destabilized in CL-depleted mitochondria from Taz knockdown hearts resulting in disruption of the interactions between ETC and the fatty acid oxidation enzymes, very long-chain acyl-CoA dehydrogenase and long-chain 3-hydroxyacyl-CoA dehydrogenase, potentially affecting the metabolic channeling of reducing equivalents between these two metabolic pathways. Mitochondria-bound myoglobin was significantly reduced in Taz-knockdown hearts, potentially disrupting intracellular oxygen delivery to the oxidative phosphorylation system. Our results identify the critical pathways affected by the Taz-deficiency in mitochondria and establish a future framework for development of therapeutic options for BTHS.
authors.affiliation: The Heart Institute, Department of Pediatrics, the University of Cincinnati College of Medicine and Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States of America.
authors.forename: Yan
authors.initials: Y
authors.lastname: Huang
authors.affiliation: The Heart Institute, Department of Pediatrics, the University of Cincinnati College of Medicine and Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States of America.
authors.forename: Corey
authors.initials: C
authors.lastname: Powers
authors.affiliation: Division of Pulmonary Medicine, Department of Pediatrics, the University of Cincinnati College of Medicine and Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States of America.
authors.forename: Satish K
authors.initials: SK
authors.lastname: Madala
authors.affiliation: Department of Cancer Biology, UC College of Medicine, University of Cincinnati, Cincinnati, OH, United States of America.
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Greis
authors.affiliation: Department of Cancer Biology, UC College of Medicine, University of Cincinnati, Cincinnati, OH, United States of America.
authors.forename: Wendy D
authors.initials: WD
authors.lastname: Haffey
authors.affiliation: The Heart Institute, Department of Pediatrics, the University of Cincinnati College of Medicine and Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States of America; University of Tennessee Health Science Center, Memphis, TN, United States of America; St. Jude Children's Research Hospital, Memphis, TN, United States of America; Le Bonheur Children's Hospital, Memphis, TN, United States of America.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Towbin
authors.affiliation: The Heart Institute, Department of Pediatrics, the University of Cincinnati College of Medicine and Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States of America.
authors.forename: Enkhsaikhan
authors.initials: E
authors.lastname: Purevjav
authors.affiliation: Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, 00936-5067, PR.
authors.forename: Sabzali
authors.initials: S
authors.lastname: Javadov
authors.affiliation: The Heart Institute, Department of Pediatrics, the University of Cincinnati College of Medicine and Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States of America.
authors.forename: Arnold W
authors.initials: AW
authors.lastname: Strauss
authors.affiliation: The Heart Institute, Department of Pediatrics, the University of Cincinnati College of Medicine and Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States of America.
authors.forename: Zaza
authors.initials: Z
authors.lastname: Khuchua
mesh_terms: D044942:Acyl-CoA Dehydrogenase, Long-Chain / Q000378:metabolism; D000217:Acyltransferases; D000818:Animals; D056889:Barth Syndrome / Q000378:metabolism* / Q000473:pathology*; D002308:Cardiolipins / Q000378:metabolism; D004195:Disease Models, Animal; D042967:Electron Transport Complex I / Q000378:metabolism; D055785:Gene Knockdown Techniques / Q000379:methods; D006321:Heart / Q000502:physiology*; D008297:Male; D053858:Metabolic Networks and Pathways / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008928:Mitochondria / Q000378:metabolism; D051336:Mitochondrial Membranes / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D010085:Oxidative Phosphorylation; D010743:Phospholipids / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D002308:Cardiolipins; D010743:Phospholipids; D014157:Transcription Factors; D044942:Acyl-CoA Dehydrogenase, Long-Chain; D000217:Acyltransferases; C486363:tafazzin protein, mouse; D042967:Electron Transport Complex I