Transforming growth factor-β in graft vessels: histology and immunohistochemistry

Abstract

OBJECTIVES: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.CONCLUSION: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.

Hemodynamic and Biologic Determinates of Arteriovenous Fistula Outcomes in Renal Failure Patients

“…Graft failure is common following coronary artery bypass grafting [ 40 , 41 ] puzzling vascular biologists and surgeons as to mechanisms. Yuan et al [ 42 ] have shown that severe vascular wall degeneration and collagen deposition together with overexpressed TGF- β signaling cytokines were responsible for failure (early and late) of the saphenous vein and radial artery grafts. As TGF- β is responsible for NH in a number of vascular disease models that have similarities to the arterialized vein in an AVF, targets to impede this early gene signaling may be future directions to help retard the aggressive NH which occurs in AVF.…”

Morphologic comparison of blood vessels used for coronary artery bypass graft surgery

“…TGFβ family includes a structurally diverse set of more than 33 cytokines that regulate the differentiation, proliferation, migration and survival of diverse cell types [46]. As Shi-Min Yuan et al (2011) states that severe vascular wall degeneration and collagen deposition together with overexpressed TGF-β signalling cytokines may provide preliminary evidence for the failure of the saphenous vein grafts [47]. This might indicate internal thoracic artery grafts longer durability.…”

Aortic ⍺-smooth muscle actin expressions in aortic disorders and coronary artery disease: An immunohistochemical study

“…Aortic tissue samples were fixed in 10% methanol solution in 1 mm 3 blocks, embedded in paraffin wax, processed routinely, and stained with hematoxylin and eosin on 4-µm sections ( 9 ). Immunohistochemical staining of α-SMA was performed using EnVision method ( 9 ). A primary antibody α-SMA sc-58671 (1:100) purchased from Santa Cruz Biotechnology, Inc., CA, USA, was used.…”