title: Evaluation of the cardiolipin biosynthetic pathway and its interactions in the diabetic heart.
abstract: OBJECTIVE
  We have previously reported alterations in cardiolipin content and inner mitochondrial membrane (IMM) proteomic make-up specifically in interfibrillar mitochondria (IFM) in the type 1 diabetic heart; however, the mechanism underlying this alteration is unknown. The goal of this study was to determine how the cardiolipin biosynthetic pathway and cardiolipin-IMM protein interactions are impacted by type 1 diabetes mellitus.
  
  
  METHODS
  Male FVB mice were made diabetic by multiple low-dose streptozotocin injections and sacrificed five weeks post-diabetic onset. Messenger RNA was measured and cardiac mitochondrial subpopulations were isolated. Further mitochondrial functional experimentation included evaluating the protein expression of the enzymes directly responsible for cardiolipin biosynthesis, as well as ATP synthase activity. Interactions between cardiolipin and ATP synthase subunits were also examined.
  
  
  RESULTS
  Western blot analysis revealed a significant decrease in cardiolipin synthase (CRLS) protein content in diabetic IFM, with a concomitant decrease in its activity. ATP synthase activity was also significantly decreased. We identified two novel direct interactions between two subunits of the ATP synthase F0 complex (ATP5F1 and ATP5H), both of which were significantly decreased in diabetic IFM.
  
  
  CONCLUSIONS
  Overall, these results indicate that type 1 diabetes mellitus negatively impacts the cardiolipin biosynthetic pathway specifically at CRLS, contributing to decreased cardiolipin content and loss of interactions with key ATP synthase F0 complex constituents in the IFM.
authors.affiliation: West Virginia University School of Medicine, Division of Exercise Physiology, Center for Cardiovascular and Respiratory Sciences, Morgantown, WV 26506, USA.
authors.forename: Tara L
authors.initials: TL
authors.lastname: Croston
authors.forename: Danielle L
authors.initials: DL
authors.lastname: Shepherd
authors.forename: Dharendra
authors.initials: D
authors.lastname: Thapa
authors.forename: Cody E
authors.initials: CE
authors.lastname: Nichols
authors.forename: Sara E
authors.initials: SE
authors.lastname: Lewis
authors.forename: Erinne R
authors.initials: ER
authors.lastname: Dabkowski
authors.forename: Rajaganapathi
authors.initials: R
authors.lastname: Jagannathan
authors.forename: Walter A
authors.initials: WA
authors.lastname: Baseler
authors.forename: John M
authors.initials: JM
authors.lastname: Hollander
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002308:Cardiolipins / Q000096:biosynthesis*; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008929:Mitochondria, Heart / Q000378:metabolism*; D051336:Mitochondrial Membranes / Q000378:metabolism*; D025261:Mitochondrial Proton-Translocating ATPases / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D013311:Streptozocin; D017855:Transferases (Other Substituted Phosphate Groups) / Q000378:metabolism
chemical_list: D002308:Cardiolipins; D008565:Membrane Proteins; D012333:RNA, Messenger; D013311:Streptozocin; D017855:Transferases (Other Substituted Phosphate Groups); C100091:cardiolipin synthetase; D025261:Mitochondrial Proton-Translocating ATPases
keywords: ATP synthase; Cardiolipin; Diabetes mellitus; Inner mitochondria membrane; Mitochondria