Limited · humanPreprint
This observational study examined the relationship between salivary oxidized forms of thymosin β4 (Tβ4) and thymosin β10 (Tβ10) and oxidative stress-related diseases in preterm infants born before 30 weeks of gestation. Researchers collected 149 saliva samples from 18 infants and analyzed the intact salivary proteome using nano-HPLC-ESI-MS, with relative quantification based on extracted ion current (XIC) peak area. The study found that post-menstrual age correlated significantly with total Tβ4, oxidized Tβ4 percentage, and total Tβ10. Higher fraction of inspired oxygen (FiO₂) values were associated with lower levels and percentages of oxidized Tβ10. Thymosin levels did not differ between infants with or without retinopathy of prematurity; however, higher oxidized Tβ10 levels were observed in infants who did not develop bronchopulmonary dysplasia (BPD), leading the authors to suggest a possible protective role for oxidized Tβ10 in inflammation and tissue repair. Key limitations include the very small sample size (18 infants), observational design, and the inability to establish causality. The authors propose saliva as a non-invasive matrix for future monitoring of oxidative stress in neonates.
Unknown journal · May 2025DOI ↗ Limited · human
This study investigated the role of CCN5, a matricellular protein, in preventing vascular restenosis after stent implantation (in-stent restenosis, ISR). Using RNA sequencing of stent-implanted porcine coronary arteries and single-cell RNA sequencing of mouse femoral artery injury models, the researchers found that CCN5 expression was reduced in vascular smooth muscle cells (VSMCs) following injury but elevated in regenerating endothelial cells (ECs). In ISR patients, plasma CCN5 levels were significantly lower and correlated inversely with restenosis severity. Using cell-type-specific loss- and gain-of-function mouse models, the study found that EC- and VSMC-specific deletion of CCN5 worsened neointimal hyperplasia, while CCN5 overexpression was protective. Mechanistically, CCN5 was found to interact with thymosin β4 (Tβ4) in ECs, promoting endothelial repair via the cleavage product Ac-SDKP, and also interacted with CD9 to support EC recovery. A CCN5 recombinant protein (CCN5rp)-coated stent deployed in a porcine model significantly increased endothelial strut coverage and reduced neointimal formation. Limitations include the translational gap between animal models and humans, and the observational nature of the patient plasma data.
European heart journal · May 2025DOI ↗ Animal only
This study investigated whether Thymosin β4 (Tβ4), a bioactive polypeptide, could regulate liver inflammation in nonalcoholic fatty liver disease (NAFLD) by influencing macrophage polarization. Researchers used a mouse model of NAFLD induced by a methionine and choline-deficient (MCD) diet in C57 mice, with liver Tβ4 knocked down via tail-vein-injected siRNA. Macrophage involvement was assessed using clodronate liposome depletion. Additionally, in vitro experiments co-cultured THP-1 macrophage cells with oleic acid-treated LO2 hepatocytes at varying Tβ4 concentrations. The study found that Tβ4 treatment was associated with reduced liver inflammation and steatosis in mice, while Tβ4 knockdown worsened steatosis. Tβ4 appeared to shift macrophages toward an M2 (anti-inflammatory) phenotype, reduce M1 marker expression, decrease hepatocyte apoptosis, downregulate STAT1 phosphorylation, and increase SOCS1/3 expression. A publicly available dataset was also used to assess Tβ4 expression in hepatocellular carcinoma-adjacent fatty tissue. Limitations include reliance primarily on animal and in vitro models, a relatively small experimental scope, and no direct human clinical data, leaving the translational relevance of these findings uncertain.
Journal of inflammation research · Apr 2025DOI ↗ Animal only
This study investigated whether inhaled recombinant human thymosin beta 4 (rhTβ4), delivered via nebulization, could reduce pulmonary fibrosis in a mouse model. Researchers induced pulmonary fibrosis in mice using bleomycin and then administered rhTβ4 aerosols at three different time points: early, mid-term, and late stages of fibrosis development. Efficacy was assessed through hydroxyproline content (a marker of collagen deposition), lung function measurements, and histopathological examination of lung tissue. The study found that nebulized rhTβ4 was associated with reduced fibrosis markers across all three dosing strategies. In parallel cell-based experiments, rhTβ4 appeared to suppress lung fibroblast proliferation, migration, and activation, and to inhibit epithelial-mesenchymal transition (EMT) in pulmonary epithelial cells, with both effects linked to modulation of the TGF-β1 signalling pathway. Limitations include the exclusive use of a mouse bleomycin model (which incompletely recapitulates human IPF), the absence of human clinical data, and the lack of direct mechanistic confirmation in vivo. The authors conclude that nebulized rhTβ4 warrants further investigation as a potential therapy for idiopathic pulmonary fibrosis.
The Journal of pharmacy and pharmacology · Apr 2025DOI ↗ Preclinical
This study investigated the biological activities of Ac-Tβ1-17, a novel acetylated peptide metabolite derived from the first 17 amino acids of thymosin β4 (Tβ4), with applications in regenerative biomaterials. Researchers first assessed its antiviral potential, finding that Ac-Tβ1-17 demonstrated protease inhibition activity against SARS-CoV-2 that reportedly exceeded that of its parent protein. In human umbilical vein endothelial cells (HUVECs), the peptide was associated with enhanced cell proliferation, wound healing, and reactive oxygen species (ROS) scavenging. The study also incorporated Ac-Tβ1-17 into a peptide-based scaffold, where it appeared to support cell growth and angiogenesis both within the scaffold and through gradual release. Mechanistically, treatment upregulated gene expression of Akt, ERK, PI3K, MEK, and Bcl-2, along with proangiogenic proteins. Ex vivo experiments in mouse fetal metatarsal tissue further suggested enhanced tissue growth and angiogenesis. Limitations include the predominantly in vitro and ex vivo design with no human clinical data, a small-animal ex vivo model, and the absence of controlled in vivo studies. The findings are exploratory and suggest Ac-Tβ1-17 as a candidate biomaterial-active peptide warranting further investigation.
Bioactive materials · Mar 2025DOI ↗ Preclinical
This study investigated the role of plasmacytoid dendritic cells (pDCs) during the active effector phase of allergic asthma, moving beyond their previously known role in immune tolerance. Using BDCA2-DTR transgenic mice in which pDCs can be selectively depleted with diphtheria toxin, researchers sensitized and challenged animals with house dust mite allergen. They found that pDC depletion worsened asthmatic inflammation by increasing CCR2-dependent recruitment of inflammatory monocyte-derived cells. RNA sequencing of lung pDCs revealed that the small anti-inflammatory peptide thymosin β4 (Tβ4) was among the most upregulated genes in asthmatic conditions. IL-33 released by airway epithelial cells was found to drive Tβ4 expression in pDCs, which represented the dominant pulmonary source of Tβ4. Mechanistically, Tβ4 suppressed IL-4/IL-13-induced JAK1/STAT6/EGR2 signaling in alveolar macrophages, reducing CCL2 production and monocyte recruitment. Tβ4 supplementation reversed disease exacerbation in pDC-depleted mice. Notably, reduced serum Tβ4 levels were observed in both asthmatic mice and a human cohort with active allergic asthma. Limitations include the predominantly murine mechanistic data and a small, cross-sectional human serum dataset that limits causal interpretation in humans.
The Journal of allergy and clinical immunology · Feb 2025DOI ↗ Preclinical
This study developed and validated a simultaneous analytical method using ultra-high-performance liquid chromatography coupled with high-resolution Orbitrap mass spectrometry (UHPLC-Q-Exactive MS/MS) to quantify TB-500 (Ac-LKKTETQ), a synthetic peptide derived from the active site of thymosin β4 (Tβ4), alongside its metabolites. Metabolism was studied in human serum, multiple in-vitro enzyme systems, and rat urine samples following TB-500 administration. Researchers synthesized authentic standards of the metabolites to enable structural identification. Key findings included that Ac-LK was the predominant short-term metabolite (0–6 hours), while Ac-LKK was detectable as a longer-term metabolite up to 72 hours. In fibroblast cell culture experiments, neither TB-500 nor its metabolites demonstrated cytotoxicity. Notably, among all compounds tested, only the metabolite Ac-LKKTE showed statistically significant wound-healing activity compared to controls, leading the authors to suggest that previously reported wound-healing effects attributed to TB-500 in the literature may actually be mediated by this metabolite rather than the parent peptide. Limitations include that biological activity testing was confined to cell-based assays, and no human pharmacokinetic or efficacy data were generated.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences · Feb 2024DOI ↗