Philp Deborah, Nguyen Mychi, Scheremeta Brooke, St-Surin Sharleen, Villa Ana M, Orgel Adam, Kleinman Hynda K, Elkin Michael
Cell Biology Section, NIDCR, National Institutes of Health, Bethesda, Maryland 20892, USA.
FASEB J. 2004 Feb;18(2):385-7. doi: 10.1096/fj.03-0244fje. Epub 2003 Dec 4.
Thymosin beta4, a 43-amino acid polypeptide that is an important mediator of cell migration and differentiation, also promotes angiogenesis and wound healing. Here, we report that thymosin beta4 stimulates hair growth in normal rats and mice. A specific subset of hair follicular keratinocytes in mouse skin expresses thymosin beta4 in a highly coordinated manner during the hair growth cycle. These keratinocytes originate in the hair follicle bulge region, a niche for skin stem cells. Rat vibrissa follicle clonogenic keratinocytes, closely related, if not identical, to the bulge-residing stem cells, were isolated and their migration and differentiation increased in the presence of nanomolar concentrations of thymosin beta4. Expression and secretion of the extracellular matrix-degrading enzyme matrix metalloproteinase-2 were increased by thymosin beta4. Thus, thymosin beta4 accelerates hair growth, in part, due to its effect on critical events in the active phase of the hair follicle cycle, including promoting the migration of stem cells and their immediate progeny to the base of the follicle, differentiation, and extracellular matrix remodeling.
胸腺素β4是一种由43个氨基酸组成的多肽，是细胞迁移和分化的重要介质，它还能促进血管生成和伤口愈合。在此，我们报告胸腺素β4可刺激正常大鼠和小鼠的毛发生长。在毛发生长周期中，小鼠皮肤中毛囊角质形成细胞的一个特定亚群以高度协调的方式表达胸腺素β4。这些角质形成细胞起源于毛囊隆突区，即皮肤干细胞的一个生态位。大鼠触须毛囊克隆形成角质形成细胞与位于隆突区的干细胞密切相关（即便不是完全相同），经分离后，在纳摩尔浓度的胸腺素β4存在的情况下，它们的迁移和分化能力增强。胸腺素β4可增加细胞外基质降解酶基质金属蛋白酶-2的表达和分泌。因此，胸腺素β4加速毛发生长，部分原因是其对毛囊周期活跃期关键事件的影响，包括促进干细胞及其直接后代迁移至毛囊底部、分化以及细胞外基质重塑。
