雷帕霉素在炎症状态下对牙髓干细胞分化能力的影响研究

Effect of rapamycin on differentiation capacity of dental pulp stem cell under inflammatory conditions

目的观察雷帕霉素(RAPA)在炎症状态下对牙髓干细胞(DPSCs)增殖和凋亡、成骨及成脂分化能力的影响。方法体外培养第四代人牙髓干细胞,加载1000 ng/ml脂多糖(LPS)作为炎症刺激,加入50 ng/ml雷帕霉素,检测炎症状态下人牙髓干细胞增殖能力、凋亡及成骨成脂分化能力改变,并检测相关基因水平的变化。结果雷帕霉素在炎症状态下对人牙髓干细胞增殖能力及凋亡没有明显影响。但是雷帕霉素可以增强炎症状态下人牙髓干细胞成骨能力,降低成脂能力。同时,检测发现ERK1/2及JNK mRNA水平下降。结论雷帕霉素通过靶向抑制mTOR通路,进而降低下游ERK1/2及JNK的表达水平,从而在炎症状态下发挥促进人牙髓干细胞成骨能力,降低成脂能力的作用。

Objective To evaluate the effect of rapamycin on the proliferation,apoptosis,osteogenesis and adipogenic differentiation capacity under inflammatory condition.Methods The fourth generation of human dental pulp stem cell(hDPSCs)cultured in vitro was used in this experiment,and 1000ng/ml lipopolysaccharide(LPS)was added as inflammatory stimulation.Then 50ng/ml rapamycin was added and the change of proliferation,apoptosis,and osteogenesis/adipogenic differentiation capacity were detected.Also the relative gene expression was checked.Results Rapamycin had no significant influence on the proliferation and apoptosis of hDPSCs under condition of LPS stimulating.While rapamycin enhanced the osteogenesis capacity of hDPSCs which was weakened under inflammatory condition.Meanwhile,rapamycin down-regulated the adipogenic capacity of hDPSCs with LPS stimulating.The relative gene level of ERK1/2 and JNK was down-regulated.Conclusion Rapamycin promoted the osteogenesis capacity and decreased the adipogenic capacity of hDPSCs under condition of inflammation through down-regulating the ERK1/2 and JNK level via inhibiting mTOR pathway.