title: Transforming growth factor-β in graft vessels: histology and immunohistochemistry.
abstract: OBJECTIVE
  The biological functions of transforming growth factor-β signaling that involves Smad proteins have not been previously investigated with respect to coronary artery bypass grafts. The aim of the present study was to observe the immunostaining of proteins that are related to this signaling pathway.
  
  
  METHODS
  Fifteen remnants of coronary artery bypass grafts, including nine saphenous veins, three radial arteries and three mammary arteries, were collected from 12 patients who were undergoing coronary artery bypass. Hematoxylin and eosin, Masson's trichrome, and immunohistochemical staining of transforming growth factor-β1, type I receptor of transforming growth factor-β, Smad2/3, Smad4, and Smad7 were performed.
  
  
  RESULTS
  The saphenous veins showed more severe intimal degeneration, more severe smooth muscle cell proliferation and more collagen deposition than the arterial grafts, as evidenced by hematoxylin and eosin and Masson's trichrome stainings. Immunohistochemical assays demonstrated that the majority of the transforming growth factor-β1 signaling cytokines were primarily localized in the cytoplasm in the medial layers of all three types of grafts, whereas ectopic transforming growth factor-β1, type I receptor of transforming growth factor-β, and Smad7 overexpressions in the interstices were observed particularly in the saphenous vein and radial arterial grafts.
  
  
  CONCLUSIONS
  Enhanced transforming growth factor-β1 signal transduction with medial smooth muscle cell proliferation and ectopic transforming growth factor-β1, the presence of the type I receptor of transforming growth factor-β, and Smad7 overexpressions in the extracellular matrix may provide primary evidence for early or late graft failure.
authors.affiliation: Department of Cardiothoracic Surgery, Jinling Hospital, School of Clinical Medicine, Nanjing University, No. 305 Zhongshan East Road, Nanjing 210002, Jiangsu Province, People's Republic of China.
authors.forename: Shi-Min
authors.initials: SM
authors.lastname: Yuan
authors.forename: Yan-Qing
authors.initials: YQ
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: Shen
authors.forename: Hua
authors.initials: H
authors.lastname: Jing
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001026:Coronary Artery Bypass; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008323:Mammary Arteries / Q000737:chemistry* / Q000473:pathology; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000737:chemistry / Q000473:pathology; D055031:Primary Graft Dysfunction / Q000378:metabolism* / Q000473:pathology; D017534:Radial Artery / Q000737:chemistry* / Q000473:pathology; D012501:Saphenous Vein / Q000737:chemistry* / Q000473:pathology; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000032:analysis*
chemical_list: D016212:Transforming Growth Factor beta