Recovery & repair

TB-500 (Thymosin Beta-4)

The full-length thymosin beta-4 protein; TB-500 refers to its active fragment.

About

Thymosin beta-4 is a 43-amino-acid protein present in most human cells and one of the principal actin-sequestering molecules in mammalian tissue. The designation TB-500 is commonly used in research supply for a synthetic fragment of this sequence rather than the full protein — a distinction worth noting when comparing sources, since the two are not chemically identical. The record referenced here is the full-length protein.

Mechanism

Thymosin beta-4 binds monomeric G-actin and regulates its availability for assembly into filamentous F-actin. Because actin polymerisation underlies cell motility, this places the protein upstream of how cells migrate into a wound bed. Research has also described associations with angiogenesis and with modulation of inflammatory signalling during tissue remodelling. As with most compounds in this category, the mechanistic work is predominantly preclinical and the translation to human outcomes is not established.

What research has examined

Studies have investigated thymosin beta-4 in models of dermal wound healing, cardiac tissue injury and corneal repair.