Thymosin Beta 4's Regenerative Powers

The Regenerative Power of Thymosin Beta 4

As the building blocks of proteins, peptides are crucial for all life. Organisms need peptides to synthesize proteins in their cells. Generally they achieve this by breaking down larger proteins in their food, and so thankfully peptide deficiencies rarely arise in subjects with a decent diet.

But scientists have discovered that pure peptides are not just raw material used by cells; peptides also modulate the activity of cells in a manner similar to hormones. Beta Thymosins are some of the most promising peptides to study because they were originally believed to hormones produced by the thyroid gland to modulate cell activity in a broad number of ways. While it turns out they aren’t true hormones, their influence on cells can be just as dramatic.

Thymosin-beta 4 in particular has garnered a lot of attention for its incredible ability to aid in tissue regeneration. Thymosin-beta 4 is a chain of just 43 little amino acids, but it has been found to have profound effects on cells’ proliferation, migration, and differentiation.

An analysis of genomic DNA from several organisms (Gomez-Marquez et. Al. 1989) found that Thymosin-beta 4 was highly conserved in mammals, but not in bacteria or other lower organisms. In rats, Thymosin-beta 4 was often found throughout all the tissues of the body, but with the highest concentrations in the lungs, spleen (esp. in lg- lymphocytes), and thymus (esp. in thymocytes). At this stage in the research, it was clear that Thymosin-beta 4 was NOT clearly related to cellular immunity and the differentiation of lymphoid cells, but what it DID do was still a mystery.

By 2010, Thymosin-beta 4’s had been identified as having several prime functions in mammal physiology, serving an important role in: blood vessel formation, stem cell differentiation, cell migration, and regulation of gene expression and major nuclear transcription factor (Crockford et. Al. 2010). This research indicates that the most promising applications of Thymosin-beta 4 are in the protection, regeneration, and repair of cardiac, dermal, or corneal tissues.

Rui et. Al. (2014) found that Thymosin-beta 4 treatement was particular effective at extending the time window for heart tissue regeneration in newborn mice. While 1-day-old mice are generally able to migrate cells and regenerate heart tissue after a partial surgical resection, 7-day-old mice lose this ability. Thymosin-beta 4 treatment allowed another group of 7-day-old mice to regenerate heart tissue just as effectively as 1-day-old mice, as if the tissues had not yet “forgotten” how to make new heart tissue.

Bollini et. Al. (2014) explain the process in more depth: Thymosin-beta 4 gains its regenerative potential from the way it reactivates epicardium-derived cells (EPDCs) in the heart after heart damage, causing these EPDCs to proliferate and differentiate into new heart tissue. This allows adult mice heart cells to regenerate like embryonic cells, without actually regressing the cellular life cycle.

It is not yet clear how long Thymosin-Beta 4 can keep windows of cellular regeneration “open” and which other tissues (if any) it might have the same effect on. The full regenerative potential of this peptide may still be untapped.

While human testing has not yet been approved, the vital importance of this peptide in facilitating the repair of mammalian heart and skin tissue makes it a very promising avenue for future study.

Works Cited:

Bollini S1, Vieira JM, Howard S, Dubè KN, Balmer GM, Smart N, Riley PR (Aug 2014). “Re-activated adult epicardial progenitor cells are a heterogeneous population molecularly distinct from their embryonic counterparts.” Stem Cells Dev. PMID 24702282.

Crockford D, Turjman N, Allan C, Angel J (April 2010). "Thymosin beta4: structure, function, and biological properties supporting current and future clinical applications". Ann. N. Y. Acad. Sci. 1194: 179–89. Bibcode:2010NYASA1194..179C. doi:10.1111/j.1749-6632.2010.05492.x. PMID 20536467.

Gomez-Marquez J, Dosil M, Segade F, Bustelo XR, Pichel JG, Dominguez F, Freire M (Nov 1989). "Thymosin-beta 4 gene. Preliminary characterization and expression in tissues, thymic cells, and lymphocytes". J Immunol 143 (8): 2740–4. PMID 2677145.

Rui L1, Yu N, Hong L, Feng H, Chunyong H, Jian M, Zhe Z, Shengshou H (Oct 2014). “Extending the time window of mammalian heart regeneration by thymosin beta 4.”  J Cell Mol Med.  PMID 25284727.