低氧对间充质干细胞生物学特性的影响

Biological effects of hypoxia on mesenchymal stem cell

机体内间充质干细胞（MSC）处于相对低氧环境（体积分数为1％～7％）与常氧环境（体积分数为20％）时表现出不同的生物学特性。低氧诱导因子1α（HIF-1α）作为低氧环境下的主要转录调控因子，广泛参与细胞的增殖、分化、凋亡、糖酵解及血管生成等方面的调控。近年来发现，HIF-1α在对MSC存活、分化及迁移的调控中起重要作用。MSC处于低氧环境时，通过对HIF-1α及其下游基因的调控，可提高MSC的存活率，促进其成软骨分化，抑制成脂分化，增强迁移能力，但对成骨分化能力的影响仍存在争议。不同组织来源、氧体积分数及诱导培养条件等均会对MSC的生物学特性造成影响。因此不同实验结果的比较应在统一的实验条件基础上进行。拟从低氧对MSC的增殖、凋亡、分化及迁移的影响作一综述。

Mesenchymal stem cell （MSC） resides in a relatively hypoxia niche （volume fraction 1%-7%） compared to normoxia （20%）. MSC cultured in hypoxia condition shows different biological features from those in normoxia condition. Hypoxia inducible factor-1α （HIF-1α）, as one of main transcription factors in hypoxia, participates in the regulation of cell proliferation, differentiation, apoptosis, glycolysis and angiogenesis. Recent researches show that HIF-1α also plays an important role in regulating the survival, differentiation and migration of MSC. It turns out that hypoxia can improve survival and migration of MSC, enhance chondrogenesis but inhibit adipogenesis through HIF-1α and its downstream genes. However, whether hypoxia promotes or impedes osteogenesis remains controversial. Such differences can be caused by variances of tissue origination, oxygen concentration and culture condition. The comparison of different researches should be based on the same experiment condition. This review focuses on the influence of hypoxia on proliferation, apoptosis, differentiation and migration of MSC.