Thymosin β4 protects and improves kidney and liver health

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Description of the potential effects of Thymosin β4 based on the literature. (This is not a product description, disclaimer at the bottom of the page)

Thymosin β4 protects and improves kidney and liver health

Thymosin β4 (Tβ4), also known as timbetasin, is a naturally occurring protein in the body that helps protect cells, reduce inflammation, promote the growth of new blood vessels and prevent tissue scarring. It shows beneficial effects on both the kidneys and liver, which are often damaged by similar harmful processes, such as oxidative stress, an overactive immune system, blood vessel damage and excessive accumulation of scar tissue. In kidney disease research, thymosin β4 has several important functions: it maintains the structure of filter cells (called podocytes) intact, prevents damage caused by immune cells, and reduces scar tissue formation (fibrosis). When administered externally from the body (as a drug), it can protect the kidneys from blood flow disorders, reduce harmful signals such as TGF-β and α-SMA in renal scarring, and improve protein levels in urine and renal tissue in diabetic models without affecting healthy kidneys.

Similarly, in the case of liver disease, it has shown benefits in a wide variety of situations, whether the damage was caused by toxins (such as CCl₄ or acetaminophen), blocked bile ducts, inflammation caused by alcohol and bacteria, or liver injury after stem cell transplantation. Thymosin β4 helps reduce liver cell death, restores antioxidant protection of the liver, attenuates inflammatory pathways such as NF-κB and TLR4, and slows scarring by turning off liver scar-forming cells (stellate cells). It also helps reactivate natural protective programs in the liver.

Thymosin β4 (Tβ4) protects kidney function in many diseases

Maintains renal cell structure and reduces inflammation in glomerulonephritis. Vasilopoulou et al. (2016) found that thymosin β4 occurs naturally in renal cells called podocytes, which are essential for filtering blood in the kidneys [1]. In mice genetically engineered to lack thymosin β4, the kidneys initially appeared normal, but became severely damaged after exposure to immune-mediated kidney disease. These mice had poorer kidney function, more inflammation around the filtration units and higher levels of scarring compared to normal mice. Their podocytes also moved away from their normal position, confirming in laboratory tests that thymosin β4 helps podocytes stay in place by stabilizing their internal structure. The study suggests that natural thymosin β4 plays a protective role by maintaining podocyte stability and reducing inflammation and fibrosis in kidney disease. Importantly, in a study involving 191 patients with sepsis in the intensive care unit, Zhang et al (2021) measured thymosin β4 levels in the blood shortly after hospital admission [2]. Patients with lower thymosin β4 levels were more likely to develop acute kidney injury (AKI), need dialysis and die within 7 or 28 days. Statistical models confirmed that low levels of thymosin β4 significantly increased these risks, and survival analysis showed higher rates of renal failure and death in this group. These findings suggest that thymosin β4 can be used as a biomarker to predict renal damage and overall prognosis in critically ill patients with sepsis, confirming its known anti-inflammatory and protective effects.

In addition, it reduces kidney scarring and cell death. Yuan et al (2017) studied a model of kidney injury in rats in which one ureter was blocked, leading to kidney scarring and cell damage [3]. Systemic administration of thymosin β4 for 14 days reduced urinary protein loss and improved tissue appearance under the microscope, especially at higher doses. It also reduced the activity of deleterious proteins involved in scar formation (TGF-β and α-SMA) and increased levels of protective protein (E-cadherin). In both laboratory and animal tests, it prevented cell death and blocked the harmful changes in kidney cells caused by TGF-β. This shows that thymosin β4 helps protect the kidneys by stopping processes that lead to fibrosis and cell damage. In addition, it protects the kidneys from blood flow disorders by combating oxidative stress and inflammation. Aksu et al (2021) tested thymosin β4 on rats with kidney damage caused by blockage and subsequent restoration of blood flow (ischemia-reperfusion) [4]. Administration of thymosin β4 before or just after blood flow blockage significantly reduced markers of kidney injury in blood and microscopic studies. It lowered oxidative stress, reduced levels of inflammation-related molecules (such as TNF-α, IL-1β, IL-6 and NF-κB) and blocked enzymes that promote cell death and tissue breakdown. The combination of these effects protected the kidneys by restoring antioxidant balance and mitigating harmful cellular reactions.

Other studies have confirmed that it improves kidney health in mice with diabetes and helps control blood sugar and lipid levels. Zhu et al. (2015) administered thymosin β4 daily for 12 weeks to mice with diabetes prone to kidney damage [5]. Compared to untreated mice, the group receiving thymosin β4 had less protein in the urine and better renal tissue structure. These benefits occurred along with improvements in blood sugar, insulin sensitivity and triglyceride levels. Interestingly, healthy mice without diabetes showed no changes, suggesting that the benefits may be specific to diabetic kidney disease. The results are consistent with the anti-inflammatory and vascular supportive effects of thymosin β4 in diabetic nephropathy.

Thymosin β4 shows strong liver protective effects in animal models of injury and fibrosis

It reduces liver damage caused by toxic chemicals by controlling oxidative stress and inflammation. Li et al (2017) studied how thymosin β4 helps protect the liver from damage caused by carbon tetrachloride (CCl₄), a toxic chemical [6]. In both mice and rats, CCl₄ elevated liver enzymes (ALT, AST), induced inflammation and fibrosis (TNF-α, IL-1β, TGF-β1, α-SMA), and caused visible liver damage, including scarring and tissue necrosis. However, when thymosin β4 was administered to animals, the harmful effects were significantly reduced. It helped normalize antioxidant levels (such as SOD and glutathione), lowered inflammatory markers such as NF-κB p65, and improved liver tissue structure. Overall, the findings suggest that it protects the liver by alleviating oxidative stress and calming inflammation, which in turn helps prevent long-term scarring . In addition, thymosin β4 helps prevent liver scarring by reducing stellate cell activity and blocking Notch pathways. Based on these results, Hong et al (2017) showed that it can also directly reduce liver fibrosis by affecting hepatic stellate cells, which are the main cells responsible for scarring [7]. In mice exposed to CCl₄, it reduced the levels of fibrosis-causing genes. In stellate cells cultured in the laboratory, thymosin β4 reduced both scarring and cell growth signals. Mechanistically, it acted by reducing the activity of Notch2 and Notch3, two proteins whose levels were elevated in fibrotic livers. These results show that it can slow liver scarring by targeting and calming stellate cells through the Notch signaling pathway.

In addition, thymosin β4 protects liver blood vessels and prevents inflammation in transplant-related liver injury. In a mouse model mimicking liver damage after stem cell transplantation (hepatic sinusoidal occlusion syndrome, HSOS), Wang et al (2023) found that it helped hepatic blood vessel cells (HSECs) survive and grow [8]. It protected them from radiation-induced damage by activating the AKT signaling pathway and enhancing survival proteins such as Bcl-xL and Bcl-2. Thymosin β4 also reduced harmful reactive oxygen species (ROS), increased antioxidant levels and decreased inflammatory markers (IL-6, IL-1β, TNF-α). In addition, it blocked signaling pathways (TLR4/MyD88/NF-κB and p38 MAPK) associated with inflammation and liver scarring. These effects translated into better liver function, less fibrosis and healthier blood vessels in treated animals.

Thymosin β4 also helps the liver recover from paracetamol overdose by restoring detoxification mechanisms and reducing inflammation. In a study on paracetamol (acetaminophen) overdose, Wang et al (2018) administered thymosin β4 to mice soon after the toxic dose [9]. This lowered liver enzyme levels, reduced liver cell death and inflammation, and preserved key antioxidants such as GSH and SOD. It also prevented the release of HMGB1, a danger signal that worsens inflammation. Importantly, it restored autophagy, a detoxification process that the liver uses to clean up damaged materials. When autophagy was blocked with chloroquine, the protective effects of thymosin β4 disappeared. This shows that the benefits of thymosin β4 largely depend on its ability to restart the liver's cleansing system and restore balance.

In another study, Zhu et al (2017) found that thymosin β4 levels were lower in fibrotic mouse livers and in lab-cultured stellate cells [10]. After artificially lowering thymosin β4 levels, the stellate cells became more active and produced more fibrosis-related proteins. However, when thymosin β4 was added again, these cells slowed down, stopped proliferating, and even began to die. This effect was linked to the PI3K/AKT pathway, a key signal for cell survival. These findings suggest that it helps prevent and reverse liver scarring by reducing the activity of stellate cells and increasing their propensity to shut down. In addition, it reduces liver fibrosis by affecting inflammation, oxidative stress and fibrosis pathways. In a study involving mice with biliary obstruction (a condition that causes liver damage and scarring), Wang et al. (2023) found that thymosin β4 levels decreased after injury [11]. However, when additional thymosin β4 was administered via gene therapy, it protected the liver by reducing levels of harmful reactive oxygen species (ROS), decreasing the activity of proteins associated with inflammation and stress (MAPK and NF-κB), and slowing the growth and movement of liver scarring cells (HSCs). Blocking the MAPK pathway enhanced these protective effects, while its activation abolished them. These results show that it works by breaking the damaging cycle between oxidative stress and inflammation that causes liver scarring.

Maintains liver cells in a healthy state, without scarring from toxic damage. Reyes-Gordillo et al. (2012) studied how thymosin β4 works during early liver damage caused by carbon tetrachloride (CCl₄), a toxic chemical [12]. In treated rats, it reduced tissue death and inflammation and inhibited fibrosis-causing genes. Importantly, it helped restore markers of "resting" liver cells (such as PPARγ) and reduced levels of proteins (such as MeCP2) associated with cell activation and fibrosis. This suggests that thymosin β4 not only reduces damage, but also keeps key liver cells in a resting, scar-free state. In addition, it helps prevent bile-associated liver fibrosis by silencing PDGF and TGFβ signals. Chen et al. (2020) showed that in mice with bile duct obstruction, treatment with thymosin β4 reduced mortality and reduced symptoms of liver damage, such as collagen accumulation and fibrosis [13]. It also inhibited two major fibrosis signaling pathways, PDGF and TGFβ/Smad, both in animals and in cultured liver cells. This led to a reduction in the activity of genes and proteins involved in fibrosis (such as α-SMA, fibronectin and collagen). These results highlight how thymosin β4 cuts off signals that cause liver cells to produce scar tissue.

In addition, thymosin β4 protects against alcohol- and endotoxin-induced liver damage by blocking stress-inducing factors and fibrosis. Shah et al. (2018) studied mice that were chronically fed alcohol and then exposed to an inflammation-inducing agent (LPS) [14]. Thymosin β4 treatment reduced liver enzymes and tissue damage, reduced oxidative stress (ROS and lipid peroxidation), and enhanced natural antioxidants (such as GSH and MnSOD). It also blocked the activation of NF-κB, a molecule that causes inflammation, and helped restore the balance between proteins that promote scarring and proteins that prevent it by reversing the effects of MeCP2 on PPARγ. This led to lower levels of fibrosis markers, including PDGFR-β and collagen. Taken together, these results support the efficacy of thymosin β4 in treating alcohol- and inflammation-induced liver damage. In another study, thymosin β4 blocked cell death and fibrosis caused by deleterious RNA. In liver cells exposed to long non-coding RNA (lincRNA-p21), which causes cell death and scarring, Yang et al (2020) showed that thymosin β4 reduced damage [15]. It decreased apoptosis signals (such as cleaved caspase-3 and -9), fibrosis markers (α-SMA, TIMP-1, collagen) and liver enzyme levels. It also suppressed harmful signals in liver scarring cells (HSCs). The protective effect of thymosin β4 on the liver depends on its ability to block the PI3K-AKT-NF-κB pathway.

Applications

In summary, studies show that thymosin β4 promotes healing in both the kidney and liver through four main actions. It protects the structural integrity of these organs by stabilizing renal filter cells and helping liver blood vessel cells survive. In addition, thymosin β4 reduces inflammation and oxidative stress by restoring antioxidant systems, such as SOD and GSH, and by lowering harmful inflammatory pathways. It also reduces levels of inflammatory molecules such as TNF-α, IL-1β and IL-6. It prevents scarring or fibrosis by reducing the production of proteins such as α-SMA, collagen and fibronectin. It also blocks the activation of scar-forming cells while promoting natural healing processes by restoring markers. The consistent improvement observed in various studies underscores the potential of thymosin β4 as a therapeutic agent for organ damage. Moreover, in intensive care unit patients, low blood levels of thymosin β4 are associated with a higher risk of renal failure and death, suggesting that it may also serve as a useful marker for identifying high-risk individuals.

Researchers need to determine the most effective dose and time of administration for each condition, as the highest dose is not necessarily the most effective. It is also essential to know how thymosin β4 is absorbed and utilized by the body. The drug's effectiveness can be increased with better methods of administration, such as extended-release formulations or gene therapy. The drug can also be combined with standard therapies such as RAAS blockers, SGLT2 inhibitors or drugs targeting bile acids and fibrosis pathways. Future clinical trials using clear and measurable indicators of kidney and liver health will be crucial to demonstrate whether this natural peptide can become a reliable therapeutic option for the treatment of kidney and liver disease.

Disclaimer

This article was written for educational purposes and is intended to raise awareness of the substance under discussion. It is important to note that the article is about the substance in general - it is not a description of a specific product (chemical reagent). We do not suggest the use of chemical reagents on humans - this is prohibited by law, for a product to be used for treatment it must be registered as a drug. The information contained in the text is based on available scientific research and is not intended to serve as medical advice or promote self-medication. The reader should consult any health and treatment decisions with a qualified health professional.

References

1. Vasilopoulou, E., Kolatsi-Joannou, M., Lindenmeyer, M. T., White, K. E., Robson, M. G., Cohen, C. D., Sebire, N. J., Riley, P. R., Winyard, P. J., and Long, D. A. (2016). Loss of endogenous thymosin β(₄₎  Accelerates the development of glomerular disease. Kidney international, 90(5), 1056-1070. https://doi.org/10.1016/j.kint.2016.06.032https://pubmed.ncbi.nlm.nih.gov/27575556/ 
2. Zhang, J., Long, M., Sun, Z., Yang, C., Jiang, X., He, L., Su, L., and Peng, Z. (2021). Association between thymosin beta-4, acute kidney injury and mortality in sepsis patients: an observational cohort study. International Immunopharmacology, 101(Pt A), 108167. https://doi.org/10.1016/j.intimp.2021.108167https://pubmed.ncbi.nlm.nih.gov/34607232/ 
3. Yuan, J., Shen, Y., Yang, X., Xie, Y., Lin, X., Zeng, W., Zhao, Y., Tian, M. and Zha, Y. (2017). Thymosin β4 attenuates renal fibrosis and tubular cell apoptosis by inhibiting TGF-β pathway in UUO rat models. BMC Nephrology, 18(1), 314. https://doi.org/10.1186/s12882-017-0708-1https://pubmed.ncbi.nlm.nih.gov/29047363/ 
4. Aksu, U., Yaman, O. M., Guner, I., Guntas, G., Sonmez, F., Tanriverdi, G., Eser, M., Cakiris, A., Akyol, S., Seçkin, İ., Uzun, H., Yelmen, N., & Sahin, G. (2021). Protective effects of thymosin-β4 in a rat model of ischemic acute kidney injury. Journal of Investigative Surgery, 34(6), 601–609. https://doi.org/10.1080/08941939.2019.1672841 https://pubmed.ncbi.nlm.nih.gov/31702404/
5. Zhu, J., Su, L.-P., Zhou, Y., Ye, L., Lee, K.-O. and Ma, J.-H. (2015). Thymosin β4 attenuates early diabetic nephropathy in a mouse model of type 2 diabetes. American Journal of Therapeutics, 22(2), 141–146. https://doi.org/10.1097/MJT.0b013e3182785ecc https://pubmed.ncbi.nlm.nih.gov/23846524/
6. Li, X., Wang, L., and Chen, C. (2017). Effects of exogenous thymosin β4 on carbon tetrachloride-induced liver injury and fibrosis. Scientific Reports, 7(1), 5872. https://doi.org/10.1038/s41598-017-06318-5https://pubmed.ncbi.nlm.nih.gov/28724974/ 
7. Hong, Y., Yao, Q., and Zheng, L. (2017). Thymosin β4 alleviates liver fibrosis by inhibiting Notch signaling. Biochemical and Biophysical Research Communications, 493(4), 1396-1401. https://doi.org/10.1016/j.bbrc.2017.09.156https://pubmed.ncbi.nlm.nih.gov/28965947/ 
8. Wang, X., Zhou, Y., Sun, Q., Zhang, Q., Zhou, H., Zhang, J., Du, Y., Wang, Y., Yuan, K., Xu, L., Zhang, M., Yan, D., Zeng, L., Xu, K. and Sang, W. (2023). Thymosin β4 exerts cytoprotective function and attenuates liver injury in mouse occluded hepatic sinus syndrome after hematopoietic stem cell transplantation. Transplantation and Cellular Therapy, 29(8), 492.e1-492.e10. https://doi.org/10.1016/j.jtct.2023.05.009https://pubmed.ncbi.nlm.nih.gov/37192732/ 
9. Wang, L., Li, X., and Chen, C. (2018). Inhibition of acetaminophen-induced hepatotoxicity in mice by exogenous administration of thymosin β4. International Immunopharmacology, 61, 20-28. https://doi.org/10.1016/j.intimp.2018.05.011 https://pubmed.ncbi.nlm.nih.gov/29793165/ 
10. Zhu, L., Cheng, M., Liu, Y., Yao, Y., Zhu, Z., Zhang, B., Mou, Q. and Cheng, Y. (2017). Thymosin-β4 inhibits proliferation and induces apoptosis of hepatic stellate cells via PI3K/AKT pathway. Oncotarget, 8(40), 68847-68853. https://doi.org/10.18632/oncotarget.18748 https://pubmed.ncbi.nlm.nih.gov/28978161/
11. Wang, Z., Zhang, Y., Wang, Y., Mou, Q., Ren, T., and Zhu, L. (2023). Mechanism of action of thymosin β4 in ameliorating liver fibrosis via MAPK/NF-κB pathway. Journal of Biochemical and Molecular Toxicology, 37(7), e23338. https://do i.org/10.1002/jbt.23338 https://pubmed.ncbi.nlm.nih.gov/37211724/
12. Reyes-Gordillo, K., Shah, R., Arellanes-Robledo, J., Rojkind, M., and Lakshman, M. R. (2012). Protective effects of thymosin β4 on acute carbon tetrachloride-induced hepatotoxicity in rats. Annals of the New York Academy of Sciences, 1269, 61–68. https://doi.org/10.1111/j.1749-6632.2012.06728.x https://pubmed.ncbi.nlm.nih.gov/23045971/
13. Chen, C., Li, X., and Wang, L. (2020). Thymosin β4 ameliorates cholestatic liver fibrosis in mice via down-regulation of PDGF/PDGFR and TGFβ/Smad pathways. Gastrointestinal and liver diseases, 52(3), 324-330. https://doi.org/10.1016/j.dld.2019.08.014 https://pubmed.ncbi.nlm.nih.gov/31542221/
14. Shah, R., Reyes-Gordillo, K., Cheng, Y., Varatharajalu, R., Ibrahim, J., and Lakshman, M. R. (2018). Thymosin β4 prevents oxidative stress, inflammation and fibrosis in ethanol- and LPS-induced liver injury in mice. Oxidative Medicine and Cellular Longevity, 2018, 9630175. https://doi.org/10.1155/2018/9630175 https://pubmed.ncbi.nlm.nih.gov/30116499/
15. Yang, L., Fu, W. L., Zhu, Y. and Wang, X. G. (2020). Tβ4 inhibits apoptosis and liver fibrosis mediated by lincRNA-p21 through inhibition of the PI3K-AKT-NF-κB pathway. Gene, 758, 144946. https://doi.org/10.1016/j.gene.2020.144946 https://pubmed.ncbi.nlm.nih.gov/32649978/