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目的:观察缺氧对软骨细胞体外培养时的失分化过程的影响，探讨胶原蛋白脯氨酰4-羟化酶（collagen prolyl 4-hydroxylases，C-P4Hs）在其中的作用。方法:对软骨细胞进行不同浓度的COCln 2处理，筛选用于缺氧诱导的最佳COCln 2浓度为100 μmol/L后，将小鼠肋软骨细胞分为：常氧组、缺氧组，分别检测第3代0.5-72 h及1、3、5、7代于72 h的各项指标。使用CCK8法及细胞计数测定增殖率，RT-qPCR、免疫荧光染色、Western blot检测各组HIF-1α、P4Hα1、P4Hα2和Col-II的动态变化。n 结果:肋软骨细胞在不同浓度COCln 2条件下培养48 h，100 μmol/L的COCln 2组增殖率最高，呈典型的铺路石状；当COCln 2浓度>150 μmol/L时，增殖率（n P0.05）。免疫荧光显示缺氧下HIF-1α与P4Hα2累积于胞核内，P4Hα2逐渐由胞核进入胞浆中。Western-blot显示缺氧组HIF-1α、P4Hα2蛋白表达（n P<0.05）增高。缺氧组ColⅡ蛋白表达（n P<0.05）在诱导后期增高。常氧与缺氧下培养肋软骨细胞1-7代，CCK8与细胞计数结果显示缺氧组各代细胞增值率及细胞数均增高（n P<0.05），且传至6-7代时仍有增殖的潜力。RT-qPCR显示缺氧组各代细胞中P4Hα2、ColⅡ的mRNΑ均增高（n P<0.05）。Western-blot显示，缺氧组各代HIF-1α、P4Hα2、ColⅡ蛋白表达（n P150 μmol/L, the proliferation rate (n P<0.05) was significantly decreased. Normal oxygen and hypoxia induced rib chondrocytes for 0-72 h, and RT-qPCR showed significant increases in P4Hα2 and Col II mRNA in hypoxia group (n P<0.05). IF showed that HIF-1α and P4Hα2 accumulated in the nucleus under hypoxia, and P4Hα2 gradually entered the cytoplasm from the nucleus. Westernblot analysis showed that HIF-1α and P4Hα2 protein expressions were significantly increased in hypoxia group (n P<0.05). The expression of Col II protein in hypoxia group (n P<0.05) increased at the induction stage. CCK8 and cell count results showed that the proliferation rate and cell number of each generation in the hypoxic group were significantly increased (n P<0.05), and there was still potential for proliferation when the cells were transferred to the 6-7 generation. RT-qPCR showed that hypoxia group each generation cells P4Hα2, Col II mRNΑ were significantly increased (n P<0.05). Westernblot results showed that HIF-1α, P4Hα2 and Col II protein expressions were increased in each generation of hypoxia group (n P<0.05).n ConcIusion:Increased expression of P4Hα2 through hypoxia induced HIF-1α can accelerate post-translational modification of Col II in chondrocytes and increase synthesis and accumulation of Col II. P4Hα2 may be responsible for increased proliferation rate and delayed dedifferentiation of chondrocytes cultured in vitro under hypoxia condition.