Proteomics analysis revealed the therapeutic role of adipose-derived mesenchymal stem cells on radiation-induced colorectal fibrosis in rats.

BACKGROUND

Radiation-induced colorectal fibrosis (RICF) is a chronic condition that can develop after pelvic radiation therapy for colorectal cancer. Adipose-derived mesenchymal stem cells (ADSCs) have emerged as promising candidate for fibrosis treatment, yet the mode of action of ADSC upon RICF remains obscure. This study aimed to investigate the optimal delivery route, treatment timing, anti-fibrotic effects, and underlying mechanisms of ADSCs upon RICF.

METHODS

The RICF rat model was constructed by single dose of 20 Gy irradiation, and ADSCs were delivered via diverse ways (e.g., tail vein injection, abdominal aorta injection, peritoneal injection, or perianal tissue injection) at different frequencies (once, twice, or thrice a week) for 10 weeks. TMT-labelled proteomic and phosphoproteomic analysis was conducted for dissecting the underlying mechanisms of ADSCs upon RICF. ADSCs were co-cultured with primary human intestinal fibroblasts to verify the anti-fibrotic effects upon radiation-induced fibroblasts. Additionally, 4D label-free proteomic analysis and 4D-parallel reaction monitoring were carried out to explore their molecular mechanisms.

RESULTS

RICF rats revealed better outcomes after intraperitoneal injection of ADSCs rather than the relative ways, and in particular, those with thrice-weekly injections showed effective prevention and improvement in RICF. Proteomic and phosphoproteomic analyses, together with multifaceted analyses (e.g., co-culture, 4D-PRM analysis), indicated Cytochrome b-245 alpha chain (Cyba) as a candidate target in mediating the efficacy of ADSCs upon RICF.

CONCLUSIONS

This comprehensive multilevel proteomic study provides valuable insights into the molecular mechanisms underlying RICF and enhances understanding of the potential of ADSCs-based cytotherapy.