Thymosin Beta-4 (Tβ4) is a 43-amino acid protein found in virtually all mammalian cells. TB-500 is a synthetic analog corresponding to the actin-binding domain of Tβ4 (residues 17–23: LKKTETQ), preserving the key functional activity of the parent protein in a smaller molecule.
G-Actin Sequestration
Tβ4's primary function is sequestration of G-actin (monomeric actin) in a 1:1 complex, modulating the G:F actin equilibrium. By buffering available G-actin, TB-500 controls the rate and direction of actin polymerization — translating to directed lamellipodia formation and accelerated cell migration toward wound sites. Keratinocytes, fibroblasts, and endothelial cells treated with Tβ4 show significantly increased migration in scratch assay models.
Integrin-Linked Kinase (ILK) Upregulation
TB-500 upregulates ILK, a serine/threonine kinase at focal adhesions that activates Akt/PKB and β-catenin survival and proliferation pathways. In myocardial infarction models, Tβ4 pretreatment activates ILK-Akt signaling to promote cardiomyocyte survival and reduce infarct size.
Cardiovascular Research
Studies from Smart et al. (MRC, UK) demonstrated Tβ4 reactivates embryonic cardiac progenitors in the adult epicardium. In mouse MI models, Tβ4 significantly improved cardiac function at 4 weeks, reduced fibrosis, and promoted new vessel formation in the infarct zone.
Tissue Repair
In a corneal-repair model, Tβ4-containing formulations accelerated epithelial repair versus vehicle controls in the referenced study.
TB-500 is a component of our Glow Blend:
Glow Blend — View Product Page →References
- Goldstein AL, Hannappel E, Kleinman HK. (2005). Thymosin β4: actin-sequestering protein moonlights to repair injured tissues. Trends Mol Med, 11(9), 421–429.
- Smart N, et al. (2007). Thymosin β4 induces adult epicardial progenitor mobilization. Nature, 445(7124), 177–182.
- Sosne G, et al. (2010). Thymosin beta 4 and corneal wound healing. Ann NY Acad Sci, 1194, 190–198.
- Bock-Marquette I, et al. (2004). Thymosin β4 activates integrin-linked kinase and promotes cardiac repair. Nature, 432(7016), 466–472.
This article summarizes publicly available research for educational purposes and does not constitute medical advice, a therapeutic claim, or a recommendation for human use. Products referenced are sold for laboratory research use only.