Enhanced Expression of Integrin Receptors During Proliferation of Activated Keratinoblasts Prepared for Transplantation as Cell Suspension in Fibrinous Matrix
Integrins are principal receptors on animal cells for binding most extracellular matrix proteins, including collagen, fibronectin, and laminin. One integrin function is to transmit mechanical forces by connecting the cytoskeletal network of keratinoblasts/keratinocytes with the exoskeleton of the connective tissue. This function is related to the maintenance of basal keratinoblasts/keratinocytes by preventing terminal differentiation. The keratinoblasts/keratinocytes remain in unrestricted proliferation. Terminal differentiation correlates with downregulation of the integrins . Cell functions like proliferation, differentiation, attachment, spreading, and migration depend on cell-matrix contacts mediated by cell surface receptors including the integrin group. The a 5 subunit, which is part of the fibronectin receptor a 5 β 1, was expressed by defined activated keratinoblasts [2, 3]. Different types of clones  develop in the secondary clonal culture of keratinoblasts: clone type mitotic keratinoblast I, II, and III (CTMK I, CTMK II and CTMK III). Changes in the frequencies of the distinct clone types can be observed as a function of the cummulative population doubling level of the heterogeneous populations. For the analysis of the biological changes accompanying cytodif-ferentiation of secondary keratinoblasts in the cell lineage, methods have been developed to enrich the three mitotic keratinoblasts from the heterogeneous mitotic populations.
KeywordsIntegrin Receptor Fibrinous Matrix Basal Cell Membrane Fibronectin Receptor Normal Human Epidermal Keratinocytes
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- 1.Hertie MD, Adams JC, Watt FM (1991) Integrin expression during human epidermal development in vivo and in vitro. Development 112:193–206.Google Scholar
- 4.Barrandon Y, Green H (1987) Three clonal types of keratinocyte with different capacities for multiplication. Cell Biology 84:2302–2306.Google Scholar
- 5.Reissig D, Bekele A, Brylla E, Steinborn B (1994) Die mitotischen und postmitotischen Zelltypen des Keratinoblasten-Stammzellsystems in der normalen menschlichen Haut. Annals of Anatomie 176(Suppl.):31.Google Scholar
- 6.Bayreuther K, Rodemann P, Francz PI, Maier K (1988) Differentiation of fibroblast stem cells. J Cell Sei Suppl 10:115–130.Google Scholar
- 7.Shipley GD, Pittelkow MR (1987) Control of growth and differentiation in vitro of human keratinocytes cultured in serum-free medium. Arch Dermatol 123:154la–1544a.Google Scholar
- 12.Meredith JE, Schwartz MA (1997) Integrins, adhesion and apoptosis. J Cell Biol 7:146–150.Google Scholar