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Título: Persistent proliferation of smooth muscle cells cultured from rabbit aorta following endothelial injury accompanied by enhanced biosynthesis of proteoglycan and collagen
Autores: Li, Zhihe.
Fecha: 1993
Publicador: McGill University - MCGILL
Fuente:
Tipo: Electronic Thesis or Dissertation
Tema: Biology, Cell.
Health Sciences, Pathology.
Descripción: Smooth muscle cell (SMC) proliferation in response to injury leads to the development of a neointima, which resembles, in many aspects, atherosclerotic lesions. Studies on experimental atherosclerosis have highlighted the role of SMC in atherogenesis. To gain further knowledge on the behaviour of SMC after arterial injury, SMC were cultured from neointimal explants with or without a covering of regenerated endothelium, 15 weeks after a single balloon catheter deendothelialization. Proliferation of these cells was studied by the examination of the cell growth curve, $ rm lbrack sp3H rbrack$-thymidine incorporation and determination of the cell cycle. The growth factors released from neointimal SMC and their effect on SMC proliferation were studied in neointimal SMC conditioned media. The production of proteoglycan and collagen by these SMC were also measured following the incorporation of radiolabelled precursors into these extracellular matrix components. The morphological features of the cells were observed using LM, TEM, SEM as well as immunofluorescence microscopy. Results revealed that neointimal SMC were characteristically different in their metabolic behaviour after injury. They have a higher proliferation rate, as indicated by higher $ rm lbrack sp3H rbrack$-thymidine incorporation and increased cell number. Neointimal SMC also exhibit alterations in their morphological features and synthesize significantly more proteoglycan and collagen. This study, demonstrated for the first time, that SMC have the ability for sustained proliferation, a long time (15 weeks) after injury. This persistent proliferation may be associated with some growth factors, such as PDGF-AB and TGF-$ beta sb1.$ These proliferating SMC and their cellular products contribute to the development of the neointima, which has many features in common with early atherosclerosis. Thus, endothelial injury is a strong and persistent stimulus for a sustained increase in thickness of the neointima,
Idioma: en