Pericellular enzymatic hydrolysis: implications for the regulation of cell proliferation in the vessel wall and the bone marrow.
The stromal microenvironment in the vessel wall as well as in the bone marrow provides specific adhesion molecules for cell-cell and cell-matrix interactions and allows a variety of growth factors to be positioned at the cell surface or the extracellular matrix for optimal signal transmission. While cell proliferation and differentiation within the different haematopoietic lineages in the bone marrow is a continuous process leading to the generation and egression of mature blood cells, endothelial and smooth muscle cells in the intact undisturbed vessel wall retain a non-proliferative quiescent cell phenotype. This changes drastically upon vascular injury, which is followed by the activation of the haemostatic system combined with a variety of growth modulatory reactions necessary for the wound healing. Several locally expressed enzymatic systems including the plasminogen activator/plasmin system, endoglycosidases and phospholipases are operative in a concerted fashion to modify the pericellular microenvironment in order to allow cell migration and invasion, but also to participate in the balance of growth regulatory processes. In particular, localization and presentation as well as mobilization and activation of growth factors are coordinated by a number of hydrolytic processes. The major components of the hydrolytic enzyme systems involved in pericellular modification as well as the consequences for the regulation of cell proliferation in the hydrolytic enzyme systems involved in pericellular modification as well as the consequences for the regulation of cell proliferation in the vessel wall and the bone marrow are discussed.
Brunner
G
G
Department of Cell Biology, New York Medical Center, NY 10016.
Preissner
K T
KT
D001853:Bone Marrow / Q000201:enzymology; D001854:Bone Marrow Cells; D002448:Cell Adhesion / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology*; D016207:Cytokines / Q000378:metabolism; D010450:Endopeptidases / Q000502:physiology*; D004730:Endothelium, Vascular / Q000166:cytology* / Q000201:enzymology; D004789:Enzyme Activation; D005109:Extracellular Matrix / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism; D006133:Growth Substances / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D008565:Membrane Proteins / Q000378:metabolism; D008666:Metalloendopeptidases / Q000378:metabolism; D009361:Neoplasm Invasiveness; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism; D010960:Plasminogen Activators / Q000378:metabolism; D019714:Tissue Inhibitor of Metalloproteinases
D016207:Cytokines; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D006133:Growth Substances; D008565:Membrane Proteins; D017395:Plasminogen Activator Inhibitor 1; D019714:Tissue Inhibitor of Metalloproteinases; D010450:Endopeptidases; D010960:Plasminogen Activators; D008666:Metalloendopeptidases