Thymosin beta 4: An emerging therapeutic candidate for kidney diseases

Summary

Review article (no new experimental data) on thymosin β4 (Tβ4) and its N-terminal metabolite N-acetyl-Ser-Asp-Lys-Pro (Ac-SDKP) in kidney disease. Tβ4 is a highly conserved 43-amino-acid peptide encoded by the X-linked TMSB4X gene and is the predominant β-thymosin in mammalian cells. The authors map intra- and extracellular mechanisms and signaling pathways, describe cell-type and spatial expression across glomerular and tubular compartments, and evaluate reported renoprotective effects across models of acute and chronic kidney injury.

Key Findings

• Once viewed mainly as an actin-sequestering molecule, Tβ4 is now considered a multifunctional regulator of cellular homeostasis
• Tβ4 and Ac-SDKP emerge as dynamic mediators of renal injury and repair
• Reported renoprotective effects include cytoprotection and anti-inflammatory and antifibrotic actions in acute and chronic kidney injury models
• Findings on fibrosis are not uniform; the authors propose frameworks that account for bidirectional effects and model-dependent mechanisms
• Translational issues reviewed include pharmacokinetics, peptide stability and delivery; key challenges are validating efficacy in more clinically relevant models, overcoming peptide instability and completing safety assessments

Relevance to TB-500

Extends the Tβ4 evidence base beyond musculoskeletal healing into kidney injury and fibrosis. The evidence reviewed comes from experimental kidney-injury models, and the abstract does not describe human trials. The review concerns Tβ4 and Ac-SDKP, not TB-500 specifically, so its findings should not be assumed to apply to TB-500 products.

Citation

Di H, Huang J, Zhang D, Ni F, Zheng R, Geng H. Peptides. 2026;195:171467. doi: 10.1016/j.peptides.2026.171467. PMID: 41570941

See Also

• Parent compound: TB-500