TB-500 (Thymosin BETA-4)

Nguyen J, Verma S, Vuong VT, Queener H, Coulson-Thomas VJ, Gesteira TF

Investigative ophthalmology & visual science

Researchers engineered a tandem TB4 peptide (tTB4) fusing two TB4 monomers into dual G-actin binding domains and compared it to native TB4 in cultured human corneal epithelial cells and a murine alkali-induced corneal injury model. The engineered peptide increased actin polymerization, cell viability, and migration in vitro, and produced greater wound closure with reduced scarring than native TB4 in the mouse model, illustrating how actin-binding-domain engineering shapes TB4's mechanism of action in epithelial repair research.

Ding Y, Wang J, Li J, Cheng Y, Zhou S, Zhang Y, et al.

Advanced science (Weinheim, Baden-Wurttemberg, Germany)

In a rat diabetic wound model, investigators delivered TB4-engineered adipose-derived stem cell extracellular vesicles via dissolvable microneedle patches. The approach reduced markers of cellular senescence and modulated the PTEN/PI3K/AKT signaling pathway, improving wound-closure kinetics in the animal model relative to controls.

Li W, Yang Y, Lin Y, Mu D

Aesthetic plastic surgery

Using adipose-derived stem cells isolated from human liposuction samples, this in vitro study found TB4 exposure increased proliferation and migration and reduced apoptosis of the cells, with concurrent changes in angiogenesis-related and Hippo-pathway gene expression, indicating a mechanistic role for TB4 in regulating stem-cell behavior in graft-survival research models.

Goldstein AL, Hannappel E, Sosne G, Kleinman HK

Expert opinion on biological therapy

This foundational review synthesizes early mechanistic work showing that TB4, released by platelets and macrophages after injury, binds actin to promote cell migration and the mobilization of stem/progenitor cells contributing to new vessel formation, and describes evidence that TB4 reduces myofibroblast numbers and fibrosis in animal wound models -- establishing the actin-binding mechanism underlying its regenerative research applications in skin, cornea, heart, and CNS injury models.

Smart N, Risebro CA, Melville AA, Moses K, Schwartz RJ, Chien KR, et al.

Annals of the New York Academy of Sciences

Using mouse coronary vessel development and adult epicardial explant models, this landmark study showed that TB4, an actin monomer-binding protein secreted from myocardium, provides a paracrine signal driving epicardium-derived progenitor cells to migrate inward and differentiate into endothelial and smooth-muscle lineages forming coronary vasculature, identifying TB4-driven epicardial reactivation as a mechanism underlying neovascularization research in the adult heart.