title: Role for Gβγ G-proteins in protease regulation during remodeling of the murine femoral artery.
abstract: BACKGROUND
  Intimal hyperplasia remains the principal lesion in the development of restenosis after vessel wall injury. G-protein coupled receptors are involved in smooth muscle cell proliferation but the role of Gβγ in arterial intimal hyperplasia has not been well defined. The aim of this study is to characterize the expression of Gβγ G-proteins in the developing intimal hyperplasia in a murine model and the impact of disruption of Gβγ signaling on intimal hyperplasia development.
  
  
  METHODS
  The murine femoral wire injury model was employed. Specimens were perfusion-fixed and sections were stained with H&E and Movat's stains such that morphometry could be performed using an Image-Pro system. Additional specimens of femoral artery were also harvested and snap frozen for Western blotting for the Gβγ expression and for Western blotting and zymography to allow for the study of gelatinase and plasminogen activator expression and activation. Contralateral vessels were used as controls. Additional vessels were immersed in pluronic gel containing an adenovirus with the Gβγ inhibitor βARK(CT).
  
  
  RESULTS
  The injured femoral arteries developed intimal hyperplasia, while sham vessels did not produce such a response. Cell proliferation peaked at 3-5 d and cell migration at 7 d after injury. There was a marked time-dependent increase in Gβγ over the 28 d following injury. Inhibition of Gβγ with βARK(CT) inhibited cell proliferation, cell migration and the development of intimal hyperplasia. Inhibition of Gβγ decreased peak uPA activity and expression without increasing early PAI-1 activity and expression. Inhibition of Gβγ reduced peak MMP-2 activity at d 1 but not at d 7 and also reduced peak MMP-9 activity at d 3. Protein expression for both MMP-2 and MMP-9 was also transiently decreased. There were no changes in TIMP-1 and TIMP-2 expression and activity.
  
  
  CONCLUSIONS
  These data demonstrate a time-dependent increase in Gβγ G-protein expression following wire injury in the mouse. Inhibition of Gβγ alters cell proliferation and migration with associated changes in MMP-2, MMP-9, and uPA expression and activity.
authors.affiliation: Vascular Biology and Therapeutics Program, The Methodist Hospital Research Institute, and Department of Cardiovascular Surgery, Methodist DeBakey Heart & Vascular Center, The Methodist Hospital, Houston, Texas 77030, USA.
authors.forename: Yiping
authors.initials: Y
authors.lastname: Zou
authors.forename: Yuyang
authors.initials: Y
authors.lastname: Fu
authors.forename: Mark G
authors.initials: MG
authors.lastname: Davies
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D004195:Disease Models, Animal; D005263:Femoral Artery / Q000201:enzymology* / Q000293:injuries* / Q000473:pathology; D044387:GTP-Binding Protein beta Subunits / Q000037:antagonists & inhibitors / Q000378:metabolism*; D044388:GTP-Binding Protein gamma Subunits / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006965:Hyperplasia / Q000473:pathology; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051379:Mice; D009131:Muscle, Smooth, Vascular / Q000201:enzymology / Q000293:injuries / Q000473:pathology; D010447:Peptide Hydrolases / Q000378:metabolism*; D010455:Peptides / Q000494:pharmacology; D011994:Recombinant Proteins / Q000494:pharmacology; D015398:Signal Transduction / Q000502:physiology; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism; D017539:Tunica Intima / Q000201:enzymology / Q000293:injuries / Q000473:pathology
chemical_list: D044387:GTP-Binding Protein beta Subunits; D044388:GTP-Binding Protein gamma Subunits; D010455:Peptides; D011994:Recombinant Proteins; C560825:Timp1 protein, mouse; D019715:Tissue Inhibitor of Metalloproteinase-1; C445259:beta-adrenergic receptor kinase inhibitory peptide; D019716:Tissue Inhibitor of Metalloproteinase-2; D010447:Peptide Hydrolases; D020778:Matrix Metalloproteinase 2; C522362:Mmp2 protein, mouse; D020780:Matrix Metalloproteinase 9; C501830:Mmp9 protein, mouse