RESUMEN
Although thymosin beta 4 (Tß4) is known to play a role in hair growth, its mechanism of action is unclear. We examined the levels of key genes in a Tß4 epidermal-specific over-expressing mouse model and Tß4 global knockout mouse model to explore how Tß4 affects hair growth. By depilation and histological examination of the skin, we confirmed the effect of Tß4 on hair growth, the number of hair shafts and hair follicle (HF) structure. The mRNA and protein expression of several genes involved in hair growth were detected by real-time PCR and western blotting, respectively. Changes in the expression of ß-catenin and Lef-1, the two key molecules in the Wnt signaling pathway, were similar to the changes observed in Tß4 expression. We also found that compared to the control mice, the mRNA and protein expression of MMP-2 and VEGF were increased in the Tß4 over-expressing mice, while the level of E-cadherin (E-cad) remained the same. Further, in the Tß4 global knockout mice, the mRNA and protein levels of MMP-2 and VEGF decreased dramatically and the level of E-cad was stable. Based on the above results, we believe that Tß4 may regulate the levels of VEGF and MMP-2 via the Wnt/ß-catenin/Lef-1 signaling pathway to influence the growth of blood vessels around HFs and to activate cell migration. Tß4 may have potential for the treatment of hair growth problems in adults, and its effects should be further confirmed in future studies.
