Abstract
Tenascin is an extracellular matrix glycoprotein contributing in early organogenesis, tissue remodeling, cancer development, and other diseases. During skin wound healing, tenascin appears transiently in the wound edges of epidermis, hair follicles muscle layer, and in the granulation tissue. By immunohistochemistry, positive staining of tenascin is observed in fibroblasts, myofibroblasts and smooth muscle cells. However, by in situ hybridization, mRNA of tenascin is observed even in the epithelial cells besides myofibroblasts and smooth muscle cells. Tenascin expression is up-regulated by various cytokines such as TGFβ, bFGF, TNFα, interleukines, angiotensin II, and down-regulated by glucocorticoid. Tenascin is the substrate for matrix metalloproteinases (MMP-1, -3, and -7), catepsin G, and leucoelastase. The degradation of tenascin occurs when cultured the cells in the presence of IL-1, -2, and -6. These cytokines likely induce tenascin proteinase (s) in the various cells.
