低氧环境及不同流体静压下体外培养的人髓核细胞凋亡的变化

Change of Apoptosis of Human Nucleus Pulposus Cells Cultured in Vitro under Hypoxic Condition and Different Hydrostatic Pressure

目的:观察体外培养的髓核细胞在低氧及不同流体静压下凋亡的变化。方法:体外培养人退变髓核细胞,根据低氧环境随机分成2组:低氧组和正常氧分压组;然后根据不同流体静压条件再随机分为3组:不加压对照组、加压50 kPa组和加压100 kPa组;用MTT和末端脱氧核苷酸转移酶介导的dUTP缺口末端标记(terminal dexynucleotidyl transferase-mediated dUTP nick end labeling,TUNEL)测定法检测髓核细胞凋亡的变化。结果:低氧状态下髓核细胞的存活率较正常氧分压状态高,凋亡细胞减少。在不同流体压力下,50 kPa压力组髓核细胞的凋亡阳性率与对照组相比,差异无统计学意义(P>0.05);100 kPa压力组比对照组髓核细胞凋亡增加31.65%,差异有统计学意义(P<0.01)。结论:低氧和低压力环境可以减少髓核细胞的凋亡。

Objective：To observe the change of apoptosis of nucleus pulposus cells cultured in vitro under hypoxic condition and different hydrostatic pressure. Methods： The human degenerative nucleus pulposus cells were cultured in vitro and randomly divided into 2 groups according to hypoxic condition： the hypoxia group and the normal oxygen partial pressure group. While the nucleus pulposus cells were randomly divided into three groups according to different hydrostatic pressure： the control group without pressure, the 50 kPa pressure group and the 100 kPa pressure group. The change of apoptosis of nucleus pulpo- sus cells was detected by methyl thiazolyl tetrazolium（MTF） method and terminal dexynucleotidyl transferase-mediated dUTP nick end labeling （TUNEL） assay. Results： As compared with that in normal oxygen partial pressure group, the proportion of survival nucleus pulposus cells in hypoxic group increased, while the number of apoptotic cells decreased. Under different hy- drostatic pressure, there was no statistically significant difference regarding the apoptotic positive rate of nucleus pulposus cells between the 50 kPa pressure group and the control group （P〉0. 05）. However, the apoptosis positive rate in the 100 kPa pressure group increased by 31.65 %, compared with that in the control group, and the difference was statistically significant （P〈0. 01）. Conclusions： Hypoxic condition, as well as low pressure condition, can reduce the occurrence of apoptosis of nu- cleus pulposus cells.