Thymosin-β4 FRAGMENT 17-23 10 mg (Without Mannitol)

TB4-Frag (residues 17-23 amino acids) in tissue repair, wound recovery, and hair development

Tβ4 is a significant molecule in eukaryotic cells for sequestering actin, and initially, LKKTET was identified as a primary actin-binding site on Tβ4 (2). Several other residues on Tβ4 also contribute to this crucial activity. A peptide containing an actin-binding site, with an additional amino acid, LKKTETQ, holds multiple biological functions beyond just binding to actin (refer to Table 2). Its presence in wound fluid (46) indicates it is a natural product from Tβ4 degradation, potentially playing physiological roles in wounds and perhaps in other regular and pathological conditions. Notably, it induces mast cell exocytosis, which might be pivotal in wound healing. Mast cells may offer additional repair elements (68, 69). This discovery could be a crucial function in the initial stages of wound healing, expediting the wound cascade. It stimulates angiogenesis both in controlled laboratory conditions and external tissues (9). In vitro, it demonstrates endothelial cell migration and tube formation, and ex vivo, it boosts sprouting from aortic rings. The sprouting from aortic rings and cell adhesion are impeded by the addition of soluble actin. One possible explanation is that the peptide might function by binding to the actin on the cell surface (45). Another hypothesis is that actin binding to the peptide obstructs the accessibility of the cell surface receptor for the peptide. LKKTETQ advances wound healing in healthy rats and aged mice, proving to be as effective as the parent molecule when applied topically to full-thickness skin wounds (70). An unexpected revelation was its ability to stimulate hair growth by activating existing follicles when topically administered to rodent skin. Therefore, LKKTETQ emerges as a primary biologically active site for Tβ4, and its activities, with the exception of angiogenesis, appear distinct from those of Ac-SDKP.