TB-500
Technical Monograph
TB-500 is a synthetic version of the naturally occurring peptide Thymosin Beta-4 (Tβ4). It is a highly conserved 43-amino acid peptide that acts as a major actin-sequestering molecule in eukaryotic cells, playing a crucial role in tissue regeneration, angiogenesis, and anti-inflammatory processes.
Mechanism of Action
Thymosin β4 functions primarily as a G-actin sequestering molecule through high-affinity binding to monomeric actin via its central actin-binding domain (amino acids 5-20). This sequestration blocks actin polymerization into F-actin, modulating cytoskeletal dynamics essential for cell motility, chemotaxis, and cytokinesis. It forms a ternary complex with actin and profilin, and interacts with focal adhesion components (PINCH and ILK), activating the ILK/Akt survival pathway. Tβ4 reactivates fetal gene programs in adult tissues by inducing protein kinase C (PKC) and promoting epithelial-to-mesenchymal transition (EMT).
Pharmacological Detail
Tβ4 interacts with focal adhesion complexes and activates the ILK/Akt survival pathway. Distinct domains control different functions: AA 1-4 regulate antifibrotic effects, 1-15 inhibit apoptosis, and 17-23 trigger angiogenesis.
Pharmacodynamics
Pleiotropic effects. Promotes angiogenesis via VEGF upregulation and the PI3K/Akt/eNOS pathway. Suppresses inflammation by inhibiting NF-κB activation and pro-inflammatory cytokines (TNF-α, IL-1β). Modulates Notch and TGF-β/Smad pathways to reduce fibrosis, and exerts anti-apoptotic effects via upregulation of Bcl-2.
Pharmacokinetics
Dose-proportional absorption.Systemic administration yields Tmax at 3-15 minutes. Vz indicates moderate tissue distribution. Primarily metabolized in kidneys via meprin α and prolyl oligopeptidase (POP) to active fragment Ac-SDKP. Renal elimination.
Preclinical Observations & In Vitro Data
Extensive preclinical data supports potent cellular regenerative and anti-inflammatory properties, particularly in cardiac and dermal tissue engineering models.
Pharmacokinetic Profile
- Receptor Affinity: High affinity for BP3 receptor
- Terminal Half-Life: 0.5-2.0 hours (increases with escalating IV dose)
- Peak Systemic Saturation (Tmax): 3-15 minutes
- Molecular Stability: High gastric stability; susceptible to UV degradation.
Observed Timeline of Action
| Timeframe | Pharmacological Effect |
|---|---|
| 3-15 mins | Peak plasma concentration (Tmax) achieved IV. |
| 4-5 hours | Keratinocyte migration stimulated 2-3-fold over baseline. |
| Day 4 | Wound reepithelialization increased 42% over controls. |
| Day 7 | Wound reepithelialization 61% greater than controls. Increased collagen deposition. |
| Day 15 | First observation of complete corneal healing in neurotrophic keratopathy trials. |
| Day 29 | 60% complete healing rate in human corneal trials vs 12.5% placebo. |
| 6 Months | LVEF improved >50% in EPC transplant patients post-MI. |
Abstract Highlights
- Binds to G-actin monomers, regulating cytoskeletal dynamics for cell migration
- Demonstrated 60% complete corneal healing rate in Phase III trials (RGN-259)
- Activates ILK/Akt signaling, inhibiting NF-κB-mediated inflammation
- Improved left ventricular ejection fraction >50% at 6 months post-MI in EPC pre-treatment study
References
Chemical Specifications
Material Handling & Stability
Strict Notice
THIS COMPOUND IS PRODUCED FOR LABORATORY RESEARCH PURPOSES ONLY. NOT FOR HUMAN CONSUMPTION. MATERIAL DATA SHEETS AND LABORATORY GUIDELINES SHOULD BE CONSULTED PRIOR TO HANDLING.