低氧激活HIF-1α对人牙周膜成纤维细胞增殖与凋亡的影响

摘要

目的:初步探讨低氧环境对人牙周膜成纤维细胞(periodontal ligament cells,PDLCs)增殖与凋亡的影响,以及低氧诱导因子-1 α(hypoxia inducible factor-1α,HIF-1α)在该过程中的作用.方法:体外常氧条件和低氧(1％O2)条件下培养PDLCs,采用四甲基偶氮唑盐(MTT)法检测低氧诱导前后PDLCs生长速度的差异;流式细胞术比较PDLCs凋亡水平的变化.Western免疫印迹和实时定量PCR检测HIF-1α的表达水平.通过小干扰RNA(HIF1α-Si)转染PDLCs,检测低氧诱导下HIF-1α水平、细胞活性以及细胞凋亡水平的变化.结果:人PDLCs在低氧环境中培养48h后细胞活性显著抑制,凋亡水平增高,HIF-1α在蛋白和mRNA水平均显著升高.小干扰RNA(aRNA)转染PDLCs并于低氧下培养后HIF-1α表达明显降低,同时细胞活性增加、细胞凋亡显著下降.结论:低氧能通过上调HIF-1α表达抑制PDLCs增殖并促进其凋亡.%Objective:To investigate the effect of hypoxia on proliferation and apoptosis in human periodontal ligament cells (PDLCs),and the role of HIF-1α in this process.Methods:PDLCs were cultured under hypoxia (1％ O2) or normoxia.MTT was used to detect cell viability of PDLCs treat with or without hypoxia.Effect ofhypoxia on apoptosis of PDLCs was detected by Annexin V-APC on a flow cytometer.Western blot and qRT-PCR were used to detect expression of HIF-1 α at protein and mRNA level respectively.HIF-1 (HIF1) was transfected into PDLCs by small interfering RNA.HIF-hα,cell viability,as well as apoptosis,were furthered detected in PDLCs.Results:In the hypoxic environment,the activity of PDLCs was significantly inhibited after 48 h of culture.The level of apoptosis was increased,and the levels of HIF-1 protein and mRNA were significantly increased After knocking down of HIF-1α with siRNA,HIF-1α was significantly downregulated in PDLCs under hypoxia,as well as increased cell viability but decreased apoptosis.Conclusion:Hypoxia inhibits proliferation and promotes apoptosis of PDLCs via upregulated HIF-1 α.