title: The role of calcium-independent phospholipase A2 in cardiolipin remodeling in the spontaneously hypertensive heart failure rat heart.
abstract: Cardiolipin (CL) is an essential phospholipid component of the inner mitochondrial membrane. In the mammalian heart, the functional form of CL is tetralinoleoyl CL [(18:2)(4)CL]. A decrease in (18:2)(4)CL content, which is believed to negatively impact mitochondrial energetics, occurs in heart failure (HF) and other mitochondrial diseases. Presumably, (18:2)(4)CL is generated by remodeling nascent CL in a series of deacylation-reacylation cycles; however, our overall understanding of CL remodeling is not yet complete. Herein, we present a novel cell culture method for investigating CL remodeling in myocytes isolated from Spontaneously Hypertensive HF rat hearts. Further, we use this method to examine the role of calcium-independent phospholipase A(2) (iPLA(2)) in CL remodeling in both HF and nonHF cardiomyocytes. Our results show that 18:2 incorporation into (18:2)(4)CL is: a) performed singly with respect to each fatty acyl moiety, b) attenuated in HF relative to nonHF, and c) partially sensitive to iPLA(2) inhibition by bromoenol lactone. These results suggest that CL remodeling occurs in a step-wise manner, that compromised 18:2 incorporation contributes to a reduction in (18:2)(4)CL in the failing rat heart, and that mitochondrial iPLA(2) plays a role in the remodeling of CL's acyl composition.
authors.affiliation: Department of Integrative Physiology, University of Colorado Cardiovascular Institute, University of Colorado at Boulder, Boulder, CO 80309-0354, USA.
authors.forename: Derek K
authors.initials: DK
authors.lastname: Zachman
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Chicco
authors.forename: Sylvia A
authors.initials: SA
authors.lastname: McCune
authors.forename: Robert C
authors.initials: RC
authors.lastname: Murphy
authors.forename: Russell L
authors.initials: RL
authors.lastname: Moore
authors.forename: Genevieve C
authors.initials: GC
authors.lastname: Sparagna
mesh_terms: D000818:Animals; D002308:Cardiolipins / Q000737:chemistry* / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006321:Heart / Q000187:drug effects / Q000503:physiopathology; D006333:Heart Failure / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D010715:Phosphatidylglycerols / Q000378:metabolism; D054512:Phospholipases A2, Calcium-Independent / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR; D013312:Stress, Physiological; D013997:Time Factors; D014022:Tissue Survival / Q000187:drug effects
chemical_list: D002308:Cardiolipins; D004791:Enzyme Inhibitors; D010715:Phosphatidylglycerols; C523441:tetralinoleoylcardiolipin; D054512:Phospholipases A2, Calcium-Independent