Description of Thymosin Beta-4

TB-500 is a synthetic analogue of naturally occurring peptide Thymosin Beta-4, which is important in regeneration of injured cells and tissues. It also decreases scar formation and fibrosis by reducing the number of myofibroblasts in wounds, and has therapeutic potential also in skin, eye, heart, and brain injuries. Advances in understanding its biology have paved the way for ongoing and potential clinical trials in treating dermal wounds, corneal injuries, and regenerating heart and CNS tissue following ischemic insults or trauma. TB-500 functions primarily as an actin-binding protein, with actin being a crucial component of cell structure forming microfilaments. Microfilaments are vital for cell shape, membrane integrity, cell movement, and certain cellular reproduction steps. Actin is also a primary component of muscle protein, essential for muscle contraction. There have been numerous research studies conducted to prove the effects of this special peptide.

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Research Confirmed Effects

1. TB-500 and Neurological Function

Thymosin β4 (Tβ4) has emerged as a promising therapeutic agent for spinal cord injury (SCI) due to its neuroprotective, anti-inflammatory, and vasculoprotective properties. In a rat model of SCI, Tβ4 treatment significantly improved locomotor recovery, increased the numbers of surviving neurons and oligodendrocytes, and reduced inflammation compared to saline-treated controls. Moreover, Tβ4 treatment led to a decrease in pro-inflammatory cytokine expression and an increase in anti-inflammatory IL-10 levels. These findings suggest that Tβ4 holds potential for SCI treatment in humans, supported by its known safety profile in clinical trials.

Beyond SCI, Thymosin β4 (Tβ4) shows promise as a therapeutic strategy for neurological injuries and neurodegenerative diseases. It promotes central nervous system (CNS) and peripheral nervous system (PNS) plasticity, neurovascular remodeling, angiogenesis, neurogenesis, and oligodendrogenesis, leading to improved functional outcomes. Oligodendrogenesis, in particular, emerges as a common mechanism underlying Tβ4's restorative effects. Further research into the role of microRNAs (miRNAs) and exosomal communication networks may provide insights into the molecular mechanisms driving Tβ4-mediated neuroprotection and regeneration, paving the way for enhanced therapeutic strategies.

Thymosin Beta-4 (Tβ4) demonstrates a protective role against oxidative stress-induced injury in spinal cord-derived neural stem/progenitor cells (NSPCs) by acting through the toll-like receptor 4 (TLR4)/myeloid differentiation primary response 88 (MyD88) pathway. When exposed to oxidative stress, NSPCs showed reduced Tβ4 expression, leading to decreased cell viability and increased apoptosis. However, treatment with Tβ4 reversed these effects, increasing cell viability and reducing apoptosis. Additionally, Tβ4 mitigated the oxidative stress-induced increase in intracellular calcium concentration, lactate dehydrogenase levels, ROS production, and pro-inflammatory cytokine expression in NSPCs. Mechanistically, Tβ4 downregulated the expression of TLR4 and MyD88, suggesting involvement of the TLR4/MyD88 pathway in its protective effects. Inhibition of this pathway mirrored the effects of Tβ4 treatment, further supporting its role in attenuating oxidative stress injury in NSPCs. These findings underscore the therapeutic potential of Tβ4 in promoting NSPC survival and enhancing spinal cord regeneration after injury, offering hope for improving outcomes in severe spinal cord injuries.

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2. Thymosin Beta-4 and Blood Vessel Growth

Thymosin β4 (Tβ4) plays multifaceted roles in vascular development, repair, and protection against disease. The formation of the vasculature is crucial for embryonic survival and influences health in later life. Tβ4, an actin monomer binding protein, participates in various processes underlying vascular network assembly, including vasculogenesis, angiogenesis, arteriogenesis, endothelial-mesenchymal transition, and extracellular matrix remodeling. While the precise molecular mechanisms of Tβ4's vascular functions remain elusive, it is known to enhance capillary formation and pericyte recruitment while perturbing vessel growth and stability when deficient. Although Tβ4's cytoskeletal remodeling is implicated in endothelial cell migration, its paracrine and nuclear roles warrant further exploration. Delineating the molecular pathways influenced by Tβ4 offers promise for identifying novel targets to prevent and treat vascular diseases. Moreover, TB-500, a derivative of TB-4, exhibits potent stimulatory effects on VEGF expression, suggesting its involvement in multiple steps of blood vessel growth and remodeling, including extracellular matrix remodeling, vasculogenesis, and angiogenesis.

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3. Thymosin Beta-4 and Hair Growth

Thymosin Beta-4 (Tβ4) has emerged as a key regulator of hair growth, stimulating the process through various mechanisms. Studies involving rat and mice models, including transgenic mice overexpressing Tβ4, have demonstrated its ability to promote hair growth. Tβ4 influences hair follicle stem cells by facilitating their growth, migration, differentiation, and protease production. The discovery of TB-500's hair growth-promoting effects stemmed from observations in genetically modified mice deficient in Tβ4, which exhibited slower hair regrowth post-shaving, while those with elevated Tβ4 levels showed accelerated hair regrowth. Microscopic examination revealed increased hair shafts and grouped hair follicles in mice with augmented Tβ4 expression, underscoring its pivotal role in regulating hair growth.

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4. Thymosin Beta-4 and Antibiotic Synergy

The study aimed to develop Thymosin Beta-4 (Tβ4) as an adjunctive therapy to antibiotics for treating bacterial keratitis, addressing multidrug resistance and corticosteroid contraindication concerns. Tβ4 adjunct therapy significantly improved disease outcome compared to PBS, Tβ4 alone, and ciprofloxacin, correlating with enhanced wound healing, host defense, and inflammation resolution. Results underscored the importance of wound healing in developing new therapies for corneal infection, with adjunctive Tβ4 offering a more efficacious approach by targeting both the infectious pathogen and deleterious host response. Furthermore, research on TB-4 and its adjuvants, particularly in the context of Pseudomonas aeruginosa infection, revealed promising outcomes, showing that TB-4 combined with ciprofloxacin enhances antibiotic effects, accelerates healing, reduces inflammation, and promotes faster recovery, offering a potential strategy to combat multi-drug resistance and enhance antibiotic efficacy.

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5. TB-500 and Cardiovascular Health

The Tβ4-Ac-SDKP pathway emerges as a promising therapeutic avenue for cardiovascular and renal diseases, with Tβ4 and Ac-SDKP demonstrating various beneficial effects. Ac-SDKP, derived from Tβ4, promotes cardiac repair post-infarction, exhibiting endothelial cell migration and myocyte survival. Both Tβ4 and Ac-SDKP possess antifibrotic and anti-inflammatory properties in multiple organs, stimulating angiogenesis. While the exact mechanisms remain unclear, potential receptors such as Ku80 have been implicated, suggesting new therapeutic opportunities for cardiovascular and renal injury. Meanwhile, hydrogels incorporating collagen, chitosan, and Tβ4 have shown promise in promoting angiogenesis and heart cell migration, offering a potential treatment avenue for myocardial infarction by reducing scarring and enhancing recovery. Additionally, TB-500 demonstrates various beneficial effects in cardiovascular health, promoting collateral blood vessel growth, endothelial cell migration, myocyte survival post-heart attack, and reducing inflammation and fibrosis, suggesting its potential therapeutic use in preventing and treating cardiovascular diseases.

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6. TB-500 and Neurodegenerative Disease

Thymosin Beta-4 (Tβ4) induces autophagy markers LC3A/B and Beclin1, protecting against Prion protein peptide (PrP)-induced neurotoxicity in HT22 cells. It maintains a balance between autophagy markers and pathway factors, while preserving cholinergic signaling markers ChTp and AChE. Tβ4's competitive effect against PrP (106-126) on autophagy and cholinergic signaling is reversed by 3-MA, suggesting its therapeutic potential in preventing neurodegenerative diseases, including prion and Alzheimer's diseases, by enhancing autophagy.

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7. Thymosin Beta-4 and Its Wide Application

Serum levels of Thymosin Beta-4 (Tβ4) are significantly elevated in rheumatoid arthritis (RA) patients compared to healthy controls and are positively associated with disease activity. Higher Tβ4 levels may also indicate resistance to treatment with disease-modifying antirheumatic drugs (DMARDs) and tumor necrosis factor (TNF)-α blockers. This suggests that Tβ4 could serve as a potential biomarker for disease activity and treatment response in RA. Further research is needed to determine whether Tβ4 could be a therapeutic target for controlling inflammation associated with RA.

Thymosin beta4 (Tβ4) has shown promising effects in promoting angiogenesis, wound healing, and hair follicle development in both normal and aged rodents. It acts by enhancing angiogenesis and cell migration, making it a potential candidate for clinical applications in wound repair and tissue regeneration. Additionally, TB-500, a derivative of Tβ4, has garnered significant attention in various fields of research, including cardiovascular and neurological diseases, as well as in enhancing the effects of antibiotics. Despite its promising therapeutic potential, TB-500 is currently limited to educational and scientific research purposes, with strict regulations against human consumption.

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References

1. A. L. Goldstein et al., „Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications“, 2012 Jan;12(1):37-51
2. P. Cheng, F. Kuang, H. Zhang, G. Ju, and J. Wang, “Beneficial effects of thymosin β4 on spinal cord injury in the rat,” Neuropharmacology, vol. 85, pp. 408–416, Oct. 2014. [PubMed]
3. M. Chopp and Z. G. Zhang, “Thymosin β4 as a restorative/regenerative therapy for neurological injury and neurodegenerative diseases,” Expert Opin. Biol. Ther., vol. 15 Suppl 1, pp. S9-12, 2015. [PubMed]
4. H. Li, Y. Wang, X. Hu, B. Ma, and H. Zhang, “Thymosin beta 4 attenuates oxidative stress-induced injury of spinal cord-derived neural stem/progenitor cells through the TLR4/MyD88 pathway,” Gene, vol. 707, pp. 136–142, May 2019. [PubMed]
5. K. N. Dubé and N. Smart, “Thymosin β4 and the vasculature: multiple roles in development, repair and protection against disease,” Expert Opin. Biol. Ther., vol. 18, no. sup1, pp. 131–139, 2018. [PubMed]
6. D. Philp, S. St-Surin, H.-J. Cha, H.-S. Moon, H. K. Kleinman, and M. Elkin, “Thymosin beta 4 induces hair growth via stem cell migration and differentiation,” Ann. N. Y. Acad. Sci., vol. 1112, pp. 95–103, Sep. 2007. [PubMed]
7. T. W. Carion et al., “Thymosin Beta-4 and Ciprofloxacin Adjunctive Therapy Improves Pseudomonas aeruginosa-Induced Keratitis,” Cells, vol. 7, no. 10, Sep. 2018. [PubMed]
8. K. M. Kassem, S. Vaid, H. Peng, S. Sarkar, and N.-E. Rhaleb, “Tβ4-Ac-SDKP pathway: Any relevance for the cardiovascular system?,” Can. J. Physiol. Pharmacol., pp. 1–11, Mar. 2019. [PubMed]
9. A. D. Shaghiera, P. Widiyanti, and H. Yusuf, “Synthesis and Characterization of Injectable Hydrogels with Varying Collagen–Chitosan–Thymosin β4 Composition for Myocardial Infarction Therapy,” J. Funct. Biomater., vol. 9, no. 2, Mar. 2018. [PubMed]
10. H.-J. Han, S. Kim, and J. Kwon, “Thymosin beta 4-Induced Autophagy Increases Cholinergic Signaling in PrP (106-126)-Treated HT22 Cells,” Neurotox. Res., Dec. 2018. [PubMed]
11. Song, Ran & Choi, Hyun & Yang, Hyung-In & Yoo, Myung & Park, Yong-Beom & Kim, Kyoung. (2012). Association between serum thymosin β4 levels of rheumatoid arthritis patients and disease activity and response to therapy. Clinical rheumatology. 31. 1253-8. 10.1007/s10067-012-2011-7. [Research Gate]
12. Philp, D., et al. “Thymosin β4 Promotes Angiogenesis, Wound Healing, and Hair Follicle Development.” Mechanisms of Ageing and Development, vol. 125, no. 2, Feb. 2004, pp. 113–115, 10.1016/j.mad.2003.11.005. [PubMed]