title: Decreasing mitochondrial fission diminishes vascular smooth muscle cell migration and ameliorates intimal hyperplasia.
abstract: OBJECTIVE
  Vascular smooth muscle cell (VSMC) migration in response to arterial wall injury is a critical process in the development of intimal hyperplasia. Cell migration is an energy-demanding process that is predicted to require mitochondrial function. Mitochondria are morphologically dynamic, undergoing continuous shape change through fission and fusion. However, the role of mitochondrial morphology in VSMC migration is not well understood. The aim of the study is to understand how mitochondrial fission contributes to VSMC migration and provides its in vivo relevance in the mouse model of intimal hyperplasia.
  
  
  RESULTS
  In primary mouse VSMCs, the chemoattractant PDGF induced mitochondrial shortening through the mitochondrial fission protein dynamin-like protein 1 (DLP1)/Drp1. Perturbation of mitochondrial fission by expressing the dominant-negative mutant DLP1-K38A or by DLP1 silencing greatly decreased PDGF-induced lamellipodia formation and VSMC migration, indicating that mitochondrial fission is an important process in VSMC migration. PDGF induced an augmentation of mitochondrial energetics as well as ROS production, both of which were found to be necessary for VSMC migration. Mechanistically, the inhibition of mitochondrial fission induced an increase of mitochondrial inner membrane proton leak in VSMCs, abrogating the PDGF-induced energetic enhancement and an ROS increase. In an in vivo model of intimal hyperplasia, transgenic mice expressing DLP1-K38A displayed markedly reduced ROS levels and neointima formation in response to femoral artery wire injury.
  
  
  CONCLUSIONS
  Mitochondrial fission is an integral process in cell migration, and controlling mitochondrial fission can limit VSMC migration and the pathological intimal hyperplasia by altering mitochondrial energetics and ROS levels.
authors.affiliation: Department of Physiology, Medical College of Georgia, Georgia Regents University, 1120 Fifteenth Street, Augusta, GA 30912-3000, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Physiology, Medical College of Georgia, Georgia Regents University, 1120 Fifteenth Street, Augusta, GA 30912-3000, USA.
authors.forename: Tianzheng
authors.initials: T
authors.lastname: Yu
authors.affiliation: Department of Physiology, Medical College of Georgia, Georgia Regents University, 1120 Fifteenth Street, Augusta, GA 30912-3000, USA.
authors.forename: Hakjoo
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Physiology, Medical College of Georgia, Georgia Regents University, 1120 Fifteenth Street, Augusta, GA 30912-3000, USA.
authors.forename: Dawn K
authors.initials: DK
authors.lastname: O'Brien
authors.affiliation: Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Sesaki
authors.affiliation: Department of Physiology, Medical College of Georgia, Georgia Regents University, 1120 Fifteenth Street, Augusta, GA 30912-3000, USA yyoon@gru.edu.
authors.forename: Yisang
authors.initials: Y
authors.lastname: Yoon
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000502:physiology*; D049109:Cell Proliferation / Q000502:physiology; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000378:metabolism; D006965:Hyperplasia / Q000378:metabolism*; D051379:Mice; D008931:Mitochondria, Muscle / Q000378:metabolism* / Q000473:pathology; D063154:Mitochondrial Dynamics / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D058426:Neointima / Q000473:pathology; D017539:Tunica Intima / Q000378:metabolism / Q000473:pathology*
keywords: Cell migration; DLP1; Drp1; Mitochondria; Mitochondrial fission; Vascular smooth muscle cells