Role of adipose-derived mesenchymal stem cells in inhibiting bleomycin-induced skin fibrosis development in nude mice / 中华整形外科杂志

ABSTRACT

Objective@#To investigate the role and the mechanism of adipose-derived mesenchymal stem cells (ADSCs) in inhibiting bleomycin-induced skin fibrosis in nude mice, in order to provide experimental basis for the prevention and treatment of dermatitis, keloid, scleroderma, and other skin fibrosis disorders.@*Methods@#Twenty-four female BALB/c nude mice aged 5-6 weeks were randomly divided into blank control group, transplantation control group, model group, and transplantation group. There were 6 mice in each group. In blank control group, PBS solution was injected subcutaneously on the back of nude mice twice a day, at intervals of 1 h. The transplanted control group was injected with 1×106/ml ADSCs 1 ml and then injected with 1 ml PBS solution at intervals of 1 h. In the model group, 1 mg/ml bleomycin was injected firstly, and then 1 ml PBS was injected at intervals of 1 h. In the transplantation group, 1 ml of bleomycin was injected firstly, and 1 ml of ADSCs were injected at intervals of 1 h. After 4 weeks injection, the skin texture of each group nude mice was grossly observed. The expression of fibrosis-related proteins was detected by Western blot. The expression of fibrosis-associated genes was detected by RT-PCR. The expression of α-smooth muscle actin (α-SMA), an indicator marker of skin fibrosis, was detected by immunohistochemistry staining. The experimental data was analyzed with GraphPad 7.0 software. Two groups were compared by t test, and multiple groups of samples were compared using one-way ANOVA. The P<0.05 was regarded as statistically significant.@*Results@#The results of Western blot showed that the expression of TGF-β1, Notch1 and α-SMA in ADSCs transplantation group was significantly lower than that in the model group, but there was no significant difference between the blank control group and the transplantation control group. Real-time PCR results showed that the expression levels of TGF-β1, type Ⅰ collagen, Notch1, and Smad3 were significantly higher than those in the ADSCs group. The expression of α-SMA mRNA in the control group, transplantation control group, model group and transplantation group was 0.37±0.01, 0.35±0.05, 1.43±0.10, and 0.83±0.03, respectively. Compared with the blank control group and the transplantation control group, the expression level of α-SMA in the model group was significantly increased (F=352.3, P=0.000), while the expression level of α-SMA in the ADSCs transplantation group was significantly lower than that in the model group (t=10.39, P=0.009).@*Conclusions@#The local injection of ADSCs may reduce the expression of TGF-β1, Smad3 and Notch1 by paracrine function, remodel the extracellular matrix, inhibit the proliferation of fibroblasts, and thus inhibit the process of skin fibrosis.