Multiple potential roles of thymosin ß4 in the growth and development of hair follicles.

ABSTRACT

The hair follicle (HF) is an important mini-organ of the skin, composed of many types of cells. Dermal papilla cells are important signalling components that guide the proliferation, upward migration and differentiation of HF stem cell progenitor cells to form other types of HF cells. Thymosin ß4 (Tß4), a major actin-sequestering protein, is involved in various cellular responses and has recently been shown to play key roles in HF growth and development. Endogenous Tß4 can activate the mouse HF cycle transition and affect HF growth and development by promoting the migration and differentiation of HF stem cells and their progeny. In addition, exogenous Tß4 increases the rate of hair growth in mice and promotes cashmere production by increasing the number of secondary HFs (hair follicles) in cashmere goats. However, the molecular mechanisms through which Tß4 promotes HF growth and development have rarely been reported. Herein, we review the functions and mechanisms of Tß4 in HF growth and development and describe the endogenous and exogenous actions of Tß4 in HFs to provide insights into the roles of Tß4 in HF growth and development.