BACKGROUND: Adipose-derived mesenchymal stem cells (ADSCs) maintain the potential of multidirectional differentiation during long-term culture in vitro, and can secrete various anti-fibrotic cytokines or growth factors that are involved in regulating fibroblast proliferation and inhibiting collagen deposition, and thereby exert anti-fibrotic effects.
OBJECTIVE: To investigate the effects of ADSCs on the proliferation and apoptosis of fibroblasts in scleroderma mice and to explore the underlying mechanisms.
METHODS: Fibroblasts were isolated and purified from the skin tissue of scleroderma mice. After passage, the cells were divided into five groups according to different treatment methods: control group, ADSCs intervention group, Wnt inhibitor HY-15597 treatment group (Wnt inhibitor group), Wnt activator SB-216763 treatment group (Wnt activator group), ADSCs+SB-216763 treatment group (combined group). Cell proliferation rate and apoptosis rate were detected using MTT and flow cytometry. The levels of collagen type I, collagen type III, and Wnt signaling pathway related proteins were detected and compared.
RESULTS AND CONCLUSION: Compared with the control group, the proliferation rate of fibroblasts in the ADSCs intervention group and Wnt inhibitor group decreased and the apoptotic rate of fibroblasts increased significantly, while the proliferation rate increased and the apoptosis rate decreased in the Wnt activator group in a time-dependent manner (P < 0.05). Compared with the Wnt activator group, the proliferation rate of fibroblasts in the combined group was significantly lowered and the apoptotic rate was significantly increased (P < 0.05). Compared with the control group, the expression of hydroxyproline, collagen type I, collagen type III, Wnt2, Wnt3a, and β-catenin in the fibroblasts of ADSCs intervention group and Wnt inhibitor group were significantly decreased, while those in the Wnt activator group were significantly increased (P < 0.05). The levels of hydroxyproline, collagen type I, collagen type III, Wnt2, Wnt3a, and β-catenin in the combined group were significantly lower than those in the Wnt activator group (P < 0.05). The overall results indicate that ADSCs can inhibit the proliferation and collagen deposition of fibroblasts in the lesion tissue of mouse scleroderma models by inhibition of the Wnt/β-catenin signaling pathway.