|
Tenascin C (TN-C) is a glycoprotein that in humans is encoded by the ''TNC'' gene. It is expressed in the extracellular matrix of various tissues during development, disease or injury, and in restricted neurogenic areas of the central nervous system. Tenascin-C is the founding member of the gene family (Tenascin). In the embryo it is made by migrating cells like the neural crest; it is also abundant in developing tendons, bone and cartilage. == Gene and expression == The human tenascin C gene, ''TNC'', is located on chromosome 9 with location of the cytogenic band at the 9q33. The entire Tenascin family coding region spans approximately 80 kilobases translating into 2203 amino acids. Expression of TN-C changes from development to adulthood. TN-C is highly expressed during embryogenesis and is briefly expressed during oranogensis, while in developed organs, expression is absent or in trace amounts. TN-C has been shown to be upregulated under pathological conditions caused by inflammation, infection, tumorigenesis, and at sites that are subject to unique biomechanics forces.〔 The regulation of TN-C is induced or repressed by a number of different factors that are expressed during embryonic tissue, as well as developed tissues during remodeling, injured, or neoplastic. TGF-β1, tumor necrosis factor-α, interleukin-1, nerve growth factor, and keratinocyte growth factor are factors that have been shown to regulate TN-C. Other extracellular matrix components such as matrix metalloproteins and integrins are also frequently co-expressed with TN-C. In the developing central nervous system, TN-C is involved in regulating the proliferation of both oligodendrocyte precursor cells and astrocytes. Expression of TN-C by radial glia precedes the onset of gliogenesis, during which time it is thought to drive the differentiation of astrocytes.〔 In the adult brain, TN-C expression is downregulated except for the areas that maintain neurogenesis into adulthood and the hypothalamus.〔 TN-C is also present in central nervous system injuries and gliomas.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Tenascin C」の詳細全文を読む スポンサード リンク
|