Preclinical
This study investigated why chemotherapy often fails to generate robust anti-tumor immunity and how the endogenous peptide thymosin alpha-1 (Tα-1) might address this gap. The researchers first observed that circulating levels of Tα-1 were reduced after chemotherapy in both cancer patients (across multiple tumor types) and tumor-bearing mice. Mechanistically, the study found that chemotherapy-induced cancer cell death produces apoptotic bodies (ABs) that are poorly immunogenic. Tα-1 was shown to bind to these ABs and interact specifically with AB-associated microRNAs—particularly miR146a-5p—protecting them from degradation by lysosomal RNase A inside dendritic cells (DCs). This protection allowed miR146a-5p to activate Toll-like receptor 7 (TLR7), which in turn licensed DC maturation, migration to tumor-draining lymph nodes, and presentation of tumor antigens to CD8+ T cells. In mouse models, therapeutic Tα-1 supplementation synergized with chemotherapy to suppress established tumors in a TLR7-dependent and miR146a-5p-dependent manner. Limitations include that mechanistic and therapeutic efficacy data are primarily from mouse models, with human data limited to observational measurements of circulating Tα-1 levels.
Cancer research · Jun 2026DOI ↗ Preclinical
This study developed a multifunctional injectable hydrogel called HCG@CDs designed to treat radiation-induced skin injury (RISI), a common complication of cancer radiotherapy. The hydrogel was constructed by cross-linking carboxymethyl chitosan (CMCS) with oxidized hyaluronic acid (OHA) conjugated to a Glycyl-L-Histidyl-L-Lysine-Copper(II) complex (GHK-Cu²⁺) via dynamic Schiff-base bonds, with carbon dots (CDs) possessing superoxide dismutase (SOD)-like activity dispersed throughout the network. The system was designed for sequential, pH-responsive drug release: CDs are rapidly released in the acidic wound environment to scavenge reactive oxygen species (ROS) and reduce early oxidative stress, while GHK-Cu²⁺ is released more gradually to promote inflammation modulation, cell migration, proliferation, and collagen deposition. Both in vitro cell-based assays and in vivo animal model experiments were conducted, with results reportedly showing reduced oxidative damage, attenuated inflammatory responses, and accelerated wound healing. Limitations include reliance on preclinical models (cell culture and animal studies), with no human clinical data presented. The translational relevance to human RISI treatment remains to be established through further clinical investigation.
Bioactive materials · Apr 2026DOI ↗ Preclinical
This study investigated whether GLP-1 receptor agonist medicines cause disproportionate loss of lean body mass (LBM) or skeletal muscle in the context of obesity-related weight loss. Researchers conducted four pre-clinical studies in obese mice and a proof-of-concept clinical trial in humans (registered as NCT05606471). In obese mice, GLP-1 medicines primarily reduced body fat, with a small but statistically significant decrease in LBM. Notably, liver mass loss exceeded muscle mass loss among lean tissues. Although absolute muscle mass and strength declined, relative muscle mass and strength improved, leading to better running performance. The study also found that muscle atrophy during immobilization was similar regardless of treatment, but GLP-1 medicines produced a distinct muscle proteome signature compared to calorie restriction alone. In the human trial, patients with obesity treated with GLP-1 medicines showed improved body composition without negative effects on strength. The authors conclude that, in middle-aged mice and humans, GLP-1 medicines slightly reduce absolute muscle values but positively affect overall body composition and mobility. Limitations include the proof-of-concept (small-scale) nature of the clinical component and the use of animal models as a primary evidence base.
Cell reports. Medicine · Mar 2026DOI ↗ Preclinical
This study investigated whether mazdutide, a dual GLP-1/glucagon receptor agonist previously studied for weight and metabolic management, could reduce early-stage metabolic dysfunction-associated steatotic liver disease (MASLD). Researchers used two model systems: mice fed a high-fat diet for 12 weeks (then treated with subcutaneous mazdutide for 4 weeks) and hepatocytes exposed to free fatty acids in cell culture (then co-treated with mazdutide or an ER stress inhibitor). The study measured blood and liver lipid profiles, liver injury markers, inflammatory cytokines, oxidative stress indicators, and liver histology, as well as protein expression linked to endoplasmic reticulum (ER) stress, inflammation, and lipid metabolism. The authors report that mazdutide treatment was associated with improved lipid metabolism, reduced hepatic steatosis, lower liver injury markers, and decreased inflammation and oxidative stress in both the animal and cell models. Mechanistically, the authors propose that mazdutide acts at least partly by dampening ER stress pathways. Key limitations include the exclusive use of preclinical models (no human subjects), a single mouse strain/diet protocol, and the early-stage disease focus, meaning translation to human MASLD remains unestablished.
Pharmaceuticals (Basel, Switzerland) · Feb 2026DOI ↗ Preclinical
This study investigated whether two peptides derived from Thymosin β4 (Tβ4) — TB500 and Ac-SDKP — could reduce Alzheimer's disease (AD)-related pathology using both cell-based and animal models. In vitro, the peptides were tested in Aβ25-35-treated HT22 neuronal cells and primary cortical neurons, where they were found to reduce neurite atrophy, restore cell viability, and modulate apoptosis-related gene expression. In BV2 microglia, the peptides suppressed LPS-induced nitric oxide production, reduced pro-inflammatory cytokines, and inhibited M1 microglial polarization. In the 5×FAD transgenic mouse model of AD, treated animals showed improved performance on the Morris water maze and novel object recognition tests compared to untreated counterparts. Immunohistochemical analyses indicated reduced glial activation and neuronal apoptosis in treated mice, along with restored axonal density in the perirhinal cortex. However, hippocampal amyloid-β plaque burden was not significantly changed. Transcriptomic profiling highlighted genes such as Foxb2 and Or2k2 as potentially relevant to the observed neuroprotective effects. Key limitations include the exclusive use of preclinical models (no human data), reliance on a single transgenic mouse strain, and the need for further mechanistic validation. No human trials were conducted.
International immunopharmacology · Dec 2025DOI ↗ Preclinical
This study investigated the role of mast cell (MC)-derived thymosin β4 (Tβ4) in stress-induced intestinal barrier dysfunction in irritable bowel syndrome (IBS). Researchers measured Tβ4 levels in colonic mucus of IBS patients and used a combination of in vitro experiments, rodent models (including Tβ4-knockout rats and MC-deficient mice), and reconstitution experiments to examine mechanisms. The study found that Tβ4 levels were elevated in the colonic mucosa and intestinal MCs of IBS patients. In animal models, Tβ4 appeared to reduce tight junction proteins and the IL22RA1/Reg3γ cascade while increasing myosin light chain kinase activity, collectively impairing the epithelial barrier. Tβ4-deficient rats showed resistance to stress-induced barrier disruption, and reintroduction of Tβ4 or wild-type peritoneal MCs restored that disruption. Mechanistically, Tβ4 release from MCs was found to depend on corticotropin-releasing hormone receptor 1 signaling rather than classic degranulation, and its barrier-impairing effects were linked to inhibition of the IL22RA1/JAK1/STAT3 signaling pathway. Limitations include reliance on rodent models for mechanistic work, modest human clinical data, and the complexity of translating these findings to therapeutic applications.
World journal of gastroenterology · Nov 2025DOI ↗ Preclinical
This study investigated how dysregulation of the NLRP3 inflammasome in melanocytes contributes to vitiligo pathogenesis. Using skin samples from vitiligo patients and a melanoma-Treg-induced vitiligo mouse model, the researchers found that NLRP3 expression is significantly elevated in vitiligo melanocytes. Mechanistically, they identified that decreased expression of the E3 ubiquitin ligase β-TrCP1 in vitiligo melanocytes reduces K27-linked ubiquitination of NLRP3, weakening its interaction with the autophagy receptor NDP52. This disrupts selective autophagic clearance of NLRP3, allowing it to hyperactivate inflammatory and pyroptotic pathways—including GSDMD pore formation and IL-1β release—ultimately destroying melanocytes. Genetic knockout of NLRP3 in mice alleviated vitiligo progression. As a potential therapeutic approach, the authors developed lysine-proline-valine (KPV)-modified deformable liposomes carrying Nlrp3 shRNA, which achieved melanocyte-targeted NLRP3 knockdown and reduced vitiligo development in mice. Key limitations include reliance primarily on a mouse model, limited human mechanistic validation, and the therapeutic intervention being tested only in animals, leaving clinical translation unestablished.
Cell death and differentiation · Sep 2025DOI ↗ Preclinical
This study investigated the role of Thymosin β4 (Tβ4) in breast cancer progression and its molecular mechanism. The researchers found that Tβ4 is significantly overexpressed in breast cancer tissues and cell lines, with high expression correlating with poorer clinical outcomes. Using functional experiments, the study showed that elevated Tβ4 promotes cancer cell proliferation, migration, epithelial-mesenchymal transition (EMT), and angiogenesis, while inhibiting apoptosis. Mechanistically, the study identified that Tβ4 directly regulates SLC7A11, a cystine/glutamate antiporter, which in turn enhances glutathione biosynthesis and suppresses lipid peroxidation — effectively inhibiting ferroptosis (an iron-dependent form of programmed cell death). Rescue experiments, conducted both in cell cultures (in vitro) and animal models (in vivo), demonstrated that silencing SLC7A11 reversed the cancer-promoting effects of Tβ4. The study concludes that a novel Tβ4/SLC7A11 signaling axis modulates ferroptosis resistance and contributes to breast cancer malignancy. Limitations include reliance on preclinical models, and no human clinical trials were conducted, leaving the translational relevance to patients yet to be established.
Cellular signalling · Sep 2025DOI ↗ Preclinical
This study investigated whether thymosin beta 4 (Tβ4), encoded by the gene TMSB4X, plays a role in Alzheimer's disease (AD) pathology and could serve as a potential intervention target. Researchers generated cerebral organoids ("mini-brains") from induced pluripotent stem cells (iPSCs) carrying familial AD (fAD)-associated mutations in the amyloid precursor protein (APP) gene. Using these organoids, they characterized dynamic changes in cellular states and found that mature neuron formation was markedly reduced in fAD organoids compared to healthy controls, alongside increased cellular senescence and beta-amyloid (Aβ) production. Notably, TMSB4X/Tβ4 expression was significantly decreased both in fAD organoid neurons and in excitatory neurons from post-mortem AD patient brain data. Treatment with Tβ4 protein appeared to rescue neurodevelopmental deficits and reduce Aβ formation in the fAD organoids. Corroborating findings were also reported in 5xFAD transgenic mice. The study concludes that Tβ4 may act as a neuroprotective factor capable of mitigating altered neurogenesis and AD pathology. Key limitations include the use of organoid and animal models rather than human clinical data, and the inherent complexity of translating organoid findings to human disease.
Stem cell reports · Aug 2025DOI ↗ Preclinical
This study developed a novel injectable soft tissue filler by loading the GHK-Cu tripeptide (glycyl-L-histidyl-L-lysine copper complex) onto hydroxyapatite microspheres (HAPs), which were then combined with carboxymethyl cellulose, glycerol, and water to form a gel formulation called GHK-Cu@CMHA. The researchers report this is the first combination of HAPs and GHK-Cu designed to address implant-induced inflammation. The formulation demonstrated sustained GHK-Cu release over 7 days in laboratory testing, along with good flowability and injectability. Using a lipopolysaccharide (LPS)-induced inflammation model tested both in cell culture (in vitro) and in animals (in vivo), the study found that GHK-Cu@CMHA reduced levels of inflammatory cytokines and reactive oxygen species (ROS), while increasing superoxide dismutase (SOD) activity, suggesting antioxidant effects. Histological staining (H&E and Masson) indicated collagen deposition at treatment sites. Key limitations include the absence of human data, reliance on an LPS-induced inflammation model that may not fully replicate clinical filler complications, and no long-term safety or efficacy follow-up. These findings are preliminary and require further clinical validation before any conclusions about human benefit can be drawn.
Colloids and surfaces. B, Biointerfaces · Jul 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 a composite hydrogel wound dressing (termed "GEK") by combining two food-derived biomaterials — oxidized konjac glucomannan (OKGM) from konjac and egg white (EW) proteins — cross-linked via Schiff base bonds to create a self-healing scaffold. The natural tripeptide-copper complex glycyl-l-histidyl-l-lysine-Cu (GHK-Cu) was incorporated into this hydrogel matrix. Researchers characterized the material's mechanical, self-repairing, and adhesive properties, then evaluated its biological performance in vitro and in vivo (likely using rodent infected wound models). The study reports that the GEK hydrogel demonstrated antibacterial and anti-inflammatory activity, promoted hemostasis through tissue adhesion, and supported neovascularization and skin regeneration. The all-natural composition was highlighted for its biocompatibility and biodegradability, with the authors proposing it as a cost-effective clinical strategy for infected wound management. Key limitations include that this is a preclinical materials science study with no human clinical data; evidence of efficacy is derived from laboratory and animal experiments. The translation of these findings to human wound care remains to be established through clinical trials.
Biomaterials research · Feb 2025DOI ↗ Preclinical
This study investigated whether the copper-bound tripeptide GHK-Cu (glycyl-l-histidyl-l-lysine-Cu²⁺) could reduce lung inflammation and fibrosis in silicosis — a serious occupational lung disease caused by chronic inhalation of crystalline silica (CS) with no approved specific treatment. Researchers first established a silicosis mouse model by exposing mice to CS, then assessed GHK-Cu's effects on lung inflammation and fibrosis. In parallel, they used the RAW264.7 macrophage cell line (an in vitro model of alveolar macrophages) to study cellular mechanisms. Using molecular docking and binding studies, they identified peroxiredoxin 6 (PRDX6) as a potential molecular target of GHK-Cu. The study reported that GHK-Cu bound to PRDX6 and attenuated CS-induced oxidative stress in alveolar macrophages, which was associated with reduced pulmonary inflammation and fibrosis in the mouse model. No significant systemic toxicity was observed in the treated animals. Key limitations include reliance on animal and cell-line models with no human clinical data, and the mechanistic link to PRDX6 requires further validation. The authors conclude that GHK-Cu warrants investigation as a potential therapeutic candidate for silicosis.
Redox biology · Jun 2024DOI ↗ 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 ↗ Preclinical
This study investigated how synthetic and endogenous ligands bind to and activate the growth hormone secretagogue receptor (GHS-R), a G-protein coupled receptor involved in growth hormone (GH) release and appetite regulation. Using radiolabeled ligand-binding assays, calcium-response (aequorin-based) assays, GH release assays in mice, receptor chimeras (human/puffer fish domain swaps), and site-directed mutagenesis, researchers characterized the structural basis of ligand-receptor interactions. The study found that synthetic agonists MK-0677 and GHS-25 displayed high binding affinity and, notably, greater in vivo GH secretagogue activity compared to the endogenous peptide ghrelin. GHS-R knockout mice showed complete abolition of activity, confirming receptor specificity. Chimera analysis identified the C-terminal region, particularly transmembrane domain 6 (TM6), as critical for ligand-dependent activation. Site-directed mutagenesis pinpointed residues D99 and W276 as essential for ligand binding, while E124 was selectively important for MK-0677, and F279 was preferentially involved in ghrelin and GHS-25 interactions. The study is primarily mechanistic and largely preclinical (in vitro and animal models), limiting direct translation to human therapeutic contexts. Its findings advance structural understanding of GHS-R and may inform future drug design efforts.
Journal of translational internal medicine · Jun 2022DOI ↗