低氧对大鼠髁突软骨细胞HIF-1α和VEGF表达的影响

Effects of hypoxia on the expression of HIF-1α and VEGF in rat mandibular condylar chondrocytes

目的:探讨低氧诱导因子-1α(hypoxia inducible factor-lα,HIF-1α)和血管内皮生长因子(vascular endothelial growthfactor,VEGF)的表达变化在髁突软骨生长发育中的意义。方法:选用3周龄SD大鼠的髁突软骨进行原代细胞培养,建立二氯化钴(CoCl2)化学低氧的细胞培养模型,RT-PCR检测常氧状态下与低氧后12、24、48 h内大鼠髁突软骨细胞HIF-1α和VEGF的mRNA表达。结果:髁突软骨细胞低氧培养后12、24 h、48 h时间点HIF-1α和VEGF的mRNA表达均明显升高(P<0.05);并且VEGF、HIF-1α表达12 h与24 h、12 h与48 h、24 h与48 h比较差异均有统计学意义;HIF-1α表达逐次升高,而VEGF在12 h达到最高点后逐次下降,但是均高于常氧状态下。结论:低氧早期可上调髁突软骨细胞HIF-1α、VEGF mRNA表达,可能在髁突软骨血管形成及生长发育发挥重要作用。

Objective： To investigate the expression of hypoxia inducible factor-1α（HIF-1α） and vascular endothelial growth factor（VEGF） in rat mandibular condylar chondrocytes cultured under hypoxic and normoxia conditions for different time periods.Methods： The condylar chondrocytes were in vitro cultured from SD rats aged 3 weeks.Cobalt chloride（CoCl2） was used as a chemical hypoxia-inducible reagent to mimic hypoxic microenvironment.HIF-1α and VEGF mRNA were detected by real-time PCR at 12,24 and 48 hours after initiation of hypoxia and normoxia conditions.Results： HIF-1α and VEGF mRNA were increased at 12,24 and 48 h after hypoxia（P〈0.05）.There were significantly differences of the expressions of HIF-1α（P〈0.05）and VEGF（P〈0.05） mRNA between 12 and 24 h,12 h and 48 h,24 h and 48 h respectively after hypoxia.In hypoxia culture HIF-1α mRNA expression was gradually increased.While VEGF mRNA reached peak at 12h,and then decreased,however,it was higher than normoxia condition at all time points.Conclusion： The expressions of HIF-1α and VEGF mRNA are up-regulated under early hypoxia in mandibular condylar chondrocytes.HIF-1α increases with the time lasting and may play a role in cartilage vascularization and development.