title: Potentially positive ageing-related variations of medial smooth muscle cells in the saphenous veins used as aortocoronary bypass grafts.
abstract: BACKGROUND
  Currently, elderly people constitute a large proportion of patients undergoing coronary artery bypass grafting (CABG). Activated smooth muscle cells in the tunica media of saphenous vein (SV) grafts are thought to play a key role in the formation of neointima and development of occluding atherosclerotic plaques. The aim of this study was to identify ageing-related variations in the expression of the smooth muscle cells pro-teins that may impact on patency rate of the grafts and the CABG outcomes.
  
  
  METHODS
  The study involved 216 consecutive patients with the mean of 62.7 ± 8.4 years who underwent isolated CABG with at least one SV aortocoronary bypass graft. Expression of a-smooth muscle actin (a-SM actin), smooth muscle-myosin heavy chain (SM-MHC), calponin (CALP), cytokeratin 8 (CK-8), metalloproteinase-2 (MMP-2) and tissue inhibitors of metalloproteinases-2 and -3 (TIMP-2, TIMP-3) in the SV wall was assessed by immunohistochemistry and correlated with the age of patients.
  
  
  RESULTS
  Calponin and a-SM actin were expressed in all studied SV transplants. SM-MHC immunoreactivity was observed in SV segments in 68.5% of patients, whereas MMP-2a and TIMPs expression was found in 75% of cases. In more than 50% of analyzed SV transplants, no expression of cytokeratin-8 was found. Moderate correlations between preexisting expressions of either cytoskeletal or hemostatic proteins in the tunica media of the SV grafts and the age of CABG patients were demonstrated. They were positive for SM-MHC (r = 0.494), CALP (r = 0.548), TIMP-2 (r = 0.413) and TIMP-3 (r = 0.406) whereas negative for CK-8 (r = -0.528) and MMP-2 (r = -0.417).
  
  
  CONCLUSIONS
  Age-dependent decreases in the expression of MMP-2 and CK-8 accompanied by increases in expression of SM-MHC, TIMP-2 and TIMP-3 may promote SV graft patency and, thus, suggest a rationale for common use of SV grafts in the elderly.
authors.affiliation: Department of Cardiac Surgery and Transplantology, Poznan University of Medical Sciences, Poland. bperek@yahoo.com.
authors.forename: Bartlomiej
authors.initials: B
authors.lastname: Perek
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Malinska
authors.forename: Jerzy
authors.initials: J
authors.lastname: Gasowski
authors.forename: Danuta
authors.initials: D
authors.lastname: Ostalska-Nowicka
authors.forename: Anna
authors.initials: A
authors.lastname: Perek
authors.forename: Marek
authors.initials: M
authors.lastname: Jemielity
authors.forename: Maciej
authors.initials: M
authors.lastname: Zabel
authors.forename: Michal
authors.initials: M
authors.lastname: Nowicki
mesh_terms: D000367:Age Factors; D000368:Aged; D002135:Calcium-Binding Proteins / Q000096:biosynthesis; D001026:Coronary Artery Bypass / Q000379:methods*; D005260:Female; D018398:Homeodomain Proteins / Q000096:biosynthesis; D006801:Humans; D053533:Keratin-8 / Q000096:biosynthesis; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis / Q000378:metabolism; D008840:Microfilament Proteins / Q000096:biosynthesis; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000166:cytology*; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000637:transplantation*; D058426:Neointima / Q000473:pathology; D012501:Saphenous Vein / Q000166:cytology* / Q000000981:diagnostic imaging / Q000637:transplantation*; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000096:biosynthesis; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000096:biosynthesis; D016896:Treatment Outcome; D017540:Tunica Media / Q000166:cytology / Q000000981:diagnostic imaging; D000096985:Calponins
chemical_list: D002135:Calcium-Binding Proteins; D018398:Homeodomain Proteins; D053533:Keratin-8; D020778:Matrix Metalloproteinase 2; D008840:Microfilament Proteins; D019716:Tissue Inhibitor of Metalloproteinase-2; D019717:Tissue Inhibitor of Metalloproteinase-3; D000096985:Calponins; C560823:TIMP2 protein, human; C088390:TIMP3 protein, human; C522361:MMP2 protein, human
keywords: MMP-2; SM-MHC; TIMP-2; TIMP-3; a-SM actin; calponin; cytokeratin 8; smooth muscle cells; venous aortocoronary grafts