甲状旁腺激素通过激活自噬调节糖皮质激素引起的髓核细胞衰老及其机制  

PTH Inhibits Senescence in Primary Rat Nucleus Pulposus Cells by Activating Autophagy Induced by Glucocorticoid

作　　者：王小英[1] 焦丽艳[1] 付治安[1] 贺靖澜[1] Wang Xiaoying;Jiao Liyan;Fu Zhian;He Jinglan(Department of Orthopedic Surgery,Affiliated Hospital of Hebei University of Engineering,Handan 056002,China)

机构地区：[1]河北工程大学附属医院骨科,邯郸056002

出　　处：《中国细胞生物学学报》2018年第7期1111-1119,共9页Chinese Journal of Cell Biology

基　　金：邯郸市科技局计划内项目(批准号:1723208067-2)资助的课题~~

摘　　要：骨质疏松与椎间盘退变密切相关,甲状旁腺素(parathyroid hormone,PTH)被认为可以缓解伴有骨松的椎间盘退变,但其对髓核细胞及椎间盘退变的作用及其机制尚不清楚。该文培养原代SD大鼠髓核细胞并进行表型鉴定,不同浓度的地塞米松(dexamethasone,DXM)作用髓核细胞48 h,细胞表面积大小测量及β-半乳糖苷酶染色分析DXM对髓核细胞衰老的影响。Western blot检测LC3-II、Beclin-1、P62、p-m TOR和p-p70S6k蛋白质水平,分析PTH对DXM处理下髓核细胞自噬水平以及m TOR信号通路的调节作用。ATG5 si RNA转染后,分析PTH对髓核细胞衰老的调控及自噬在其中的作用机制。结果显示,随着DXM的处理浓度增加,髓核细胞体积增大,β-半乳糖苷酶阳性率增加(P<0.05);PTH提高DXM处理下髓核细胞中LC3-II和Beclin-1蛋白质水平,降低P62蛋白质水平,并且降低p-m TOR和p-p70S6k蛋白质水平(P<0.05);PTH可以抑制DXM引起的髓核细胞的体积增大和β-半乳糖苷酶阳性率升高,但是ATG5 si RNA转染抑制自噬后却显著逆转PTH对细胞衰老的保护作用(P<0.05)。该研究结果提示,PTH可能通过m TOR信号通路激活髓核细胞自噬来缓解DXM引起的髓核细胞衰老。Osteoporosis is closely related to the degeneration of the intervertebral disc. Parathyroid hormone（PTH） is thought to relieve the disc degeneration associated with osteoporosis, but its effect on the degeneration of nucleus pulposus cells and disc herniation is not yet clear. In this paper, primary SD rat nucleus pulposus cells were cultured and phenotyped. Nucleus pulposus cells were treated with dexamethasone（DXM） for 48 h. Cell area analysis and β-galactosidase staining were used to analyze the effect of DXM on nucleus pulposus cell senescence. Protein levels of LC3-II, Beclin-1, P62, p-m TOR and p-p70 S6 k detected by Western blot to analyze the regulatory effect of PTH on the autophagy and m TOR pathway in the cells treated with DXM. After ATG5 si RNA transfection, the regulation of PTH on nucleus pulposus cell senescence and the involvement of autophagy were analyzed. The results showed that as the concentration of DXM increased, the morphology of nucleus pulposus were enlarged and the positive rate of β-galactosidase were increased（P0.05）. PTH increased LC3-II and Beclin-1 pro-tein levels, decreased P62 protein levels and inhibited p-m TOR and p-p70 S6 k protein expression in DXM-treated nucleus pulposus cells（P0.05）. PTH could attenuate the effect of DXM on the positive rate of β-galactosidase and cellular morphology; However, ATG5 si RNA transfection reversed the protective effect of PTH on cell senescence（P0.05）. The results of this study suggested that PTH might relieve the senescence of nucleus pulposus cells induced by DXM by activating autophagy via m TOR pathway.

关 键 词：髓核细胞 甲状旁腺素 地塞米松 细胞衰老 

分 类 号：R681.53[医药卫生—骨科学]