2022, Vol. 26 ›› Issue (30): 4780-4786

Integrin-targeted peptide promotes proliferation of bone marrow mesenchymal stem cells in SD rats

Jia Qiyu1, Huang Xiaoxia1, Guo Jian1, Huang Jinyong2, Guo Xiaobin3, Abdussalam·Alimujiang1, Wu Tong1, Ma Chuang1   

Abstract: BACKGROUND: Studies have reported that integrin-targeted peptide dopamine-arginine-glycine-aspatic acid (DOPA-RGD) could inhibit osteoclast activation and promote cell adhesion, while the optimal concentration and optimal time to apply DOPA-RGD peptide to intervene with bone marrow mesenchymal stem cells or modified titanium-based materials are unclear.  
OBJECTIVE: To investigate the optimal mass concentration and the optimal intervention time of DOPA-RGD peptide to produce pro-proliferative effect when acting on bone marrow mesenchymal stem cells in rats.
METHODS: SD rat bone marrow mesenchymal stem cells were isolated and cultured in vitro and the cells with the required purity were selected for the next step of intervention. The third-generation bone marrow mesenchymal stem cells were inoculated in 96-well culture plates. Cells in the control group were cultured with simple α-MEM complete medium, while the remaining of the experimental groups were cultured with conditioned medium containing 2.5, 5, 10, 20, 40, and 80 mg/L DOPA-RGD peptide. Cell proliferation was measured by CCK-8 method after 1, 3, 5, and 7 days of DOPA-RGD peptide intervention. The optimal mass concentration and intervention time of DOPA-RGD peptide in bone marrow mesenchymal stem cells were selected, and the optimal mass concentration of DOPA-RGD peptide in bone marrow mesenchymal stem cells was further verified by apoptosis rate using flow cytometry. The effect of optimal mass concentration of DOPA-RGD peptide on the migration ability of bone marrow mesenchymal stem cells was verified by scratch assay.  
RESULTS AND CONCLUSION: (1) Using repeated measures analysis of variance, the absorbance values of the cells intervened by DOPA-RGD peptide changed differently between different time length groups, and the best proliferation effect was achieved by the 5th day of intervention, and the difference was significant (F=3 012.618, P < 0.001). Paired comparison of grouping factors by the LSD method showed that there was a significant difference between the 10 mg/L DOPA-RGD peptide group and the three groups with concentrations greater than or equal to 20 mg/L and the control group (P < 0.01). (2) Apoptosis rate assay showed that DOPA-RGD peptide at a mass concentration of 10 mg/L on the fifth day of intervention significantly reduced the apoptosis rate of bone marrow stem cells compared with the rest of the groups (P < 0.001). (3) Compared with the control group, 10 mg/L DOPA-RGD peptide intervention for 24 hours showed some migration ability of bone marrow mesenchymal stem cells and the migration speed was significantly accelerated. (4) The results showed that 10 mg/L DOPA-RGD peptide intervention on day 5 had a significant pro-proliferative effect on bone marrow mesenchymal stem cells.
Key words: integrin, DOPA-RGD peptide, integrin-targeted peptide, bone marrow mesenchymal stem cells, cell proliferation, cell migration, distraction osteogenesis, rats