表皮生长因子对人牙髓细胞DNA合成及细胞周期的影响

Effects of EGF on the cell cycling of human dental pulp cells and DNA synthesis

目的研究表皮生长因子(EGF)对体外培养的人牙髓细胞(HDPCs)DNA合成及细胞周期的影响.方法将培养的第5代HDPCs分成EGF(1ng/ml)实验组和对照组,分别以含5%FBS的DMEM培养48h;常规消化、固定细胞,调整细胞密度为2.0×106/ml,经DNA荧光染色后用流式细胞仪(FCM)测定DNA分子含量.结果与对照组相比,EGF实验组HDPCs的DNA合成前期细胞比例(G1%)明显降低,而DNA合成期细胞比例(S%)及细胞增殖指数PrI值(S+G2M)%均显著增高.结论EGF具有促进HDPCs的DNA合成和分裂增殖的作用,可能主要是通过促使处于G1期的细胞进入S期来实现的;提示EGF在牙髓组织的损伤修复过程中起着重要作用.

Objective To study the effects of epidermal growth factor (EGF) on the cell cycling and DNA synthesis of human dental pulp cells (HDPCs). Methods The 5th passage of HDPCs were cultured with and without Ing/ml EGF in DMEM supplemented with 5% fetal bovine serum (FBS) for 48h. Flow cytometry (FCM) was used to measure DNA content. The collected cells were trypsinized and fixed, then 2. 0×106 cells/ml were stained by propidium iodide before DNA specific fluorescence were measured. Results The percentage of HDPCs in G1 phase during exponential growth was decreased by a function of Ing/ml EGF compared with the control, while the percentage of HDPCs in S phase and S+ G2M was increased in the experimental group. Conclusion EGF can stimulate DNA synthesis of HDPCs in vitro. It suggests that the proliferation of HDPCs be most probably regulated by EGF in the G1 phase of cell cycle. EGF can be regarded as a positive regulatory growth factor and may play a role in the repair of human dental pulp tissue.