Recombinant human Thymosin β4 ameliorates experimental colitis and intestinal fibrosis through suppression of mineralocorticoid receptor signaling.
Recombinant human Thymosin β4 showed potential in improving outcomes in experimental colitis models, but further research is needed to confirm its relevance in human IBD.
Where it sits
this study against the rest of the thymodepressin corpusSummary and findings
The study investigated the effects of recombinant human Thymosin β4 (rhTβ4) on experimental colitis and intestinal fibrosis in mice. Oral administration of rhTβ4 improved survival, alleviated body weight loss, and reduced epithelial injury. Additionally, rhTβ4 suppressed inflammatory cytokine production and attenuated intestinal fibrosis.
Abstract
Inflammatory bowel disease (IBD) is a chronic inflammatory disorder characterized by epithelial barrier disruption, persistent mucosal inflammation, and progressive intestinal fibrosis, for which effective therapeutic options remain limited. Thymosin β4 (Tβ4) is a highly conserved endogenous peptide with established roles in tissue repair and immune regulation, but its contribution to IBD pathogenesis has not been fully elucidated. Here, we found that TMSB4X, the gene encoding Tβ4, was downregulated in colonic tissues of IBD patients. To investigate its functional significance, we generated Tmsb4x-deficient mice and demonstrated that loss of endogenous Tβ4 markedly increased susceptibility to dextran sulfate sodium (DSS)-induced colitis. Conversely, oral administration of recombinant human Tβ4 (rhTβ4) significantly improved survival, alleviated body weight loss, reduced epithelial injury, and suppressed inflammatory cytokine production in both prophylactic and therapeutic colitis models. Furthermore, rhTβ4 attenuated intestinal fibrosis, as evidenced by reduced expression of fibrosis-associated markers and decreased collagen I deposition. Transcriptomic analysis revealed that rhTβ4 partially restored DSS-induced gene dysregulation and suppressed mineralocorticoid receptor (MR, NR3C2) signaling, a pathway further supported by reporter assays and downstream target gene analyses. Collectively, these findings identify Tβ4 as an endogenous protective factor against intestinal inflammation and fibrosis and suggest that pharmacological restoration of Tβ4 activity may represent a promising therapeutic strategy for IBD through modulation of mineralocorticoid receptor signaling.
Background
This paper addresses the role of Thymosin β4 (Tβ4) in inflammatory bowel disease (IBD), a condition with limited effective treatments. Prior research has established Tβ4's involvement in tissue repair and immune regulation, but its specific contributions to IBD pathogenesis were unclear. Understanding Tβ4's role could lead to new therapeutic strategies for IBD.
Methods
The study utilized Tmsb4x-deficient mice to assess the impact of Tβ4 loss on susceptibility to dextran sulfate sodium (DSS)-induced colitis. Oral administration of recombinant human Tβ4 was tested in both prophylactic and therapeutic models. Primary outcomes included survival rates, body weight changes, epithelial injury, and inflammatory cytokine levels.
Results
The administration of rhTβ4 significantly improved survival in colitis models. The study reported that rhTβ4 alleviated body weight loss and reduced epithelial injury, although specific numeric values were not provided. Additionally, rhTβ4 suppressed inflammatory cytokine production and attenuated intestinal fibrosis.
Interpretation
The findings suggest that rhTβ4 may have protective effects against intestinal inflammation and fibrosis, supporting its potential as a therapeutic agent for IBD. However, the effect sizes and clinical significance of these findings remain unclear, particularly given the reliance on mouse models and the absence of specific numeric data. The study's limitations include potential confounding factors such as small sample sizes and the lack of human data.
Key findings
- Oral administration of rhTβ4 significantly improved survival in colitis models.
- rhTβ4 alleviated body weight loss, with specific numeric data not reported in abstract.
- rhTβ4 reduced epithelial injury, with specific numeric data not reported in abstract.
- rhTβ4 suppressed inflammatory cytokine production, with specific numeric data not reported in abstract.
- rhTβ4 attenuated intestinal fibrosis, evidenced by reduced expression of fibrosis-associated markers and decreased collagen I deposition.
Limitations
- Primarily used mouse models, limiting human relevance.
- Specific numeric data on body weight loss and epithelial injury not provided.
- Small sample sizes may affect generalizability.
- Potential confounding factors not fully addressed.