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Endoplasmic reticulum stress in degenerative human nucleus pulposus cells



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Endoplasmic reticulum stress in degenerative human nucleus pulposus cells


WEN Tianyong LIU Yue CHENG Shi YING Jinwei RUAN Dike


Department of Orthopedics Xijing Hospital Air Force Military Medical University Xi&rsquoan Shaanxi Province 710032 Department of Orthopedic Surgery Navy General Hospital Beijing 100048 China


ObjectiveTo investigate the difference in the levels of endoplasmic reticulum (ER) stress between degenerative and normal human nucleus pulposus cells. MethodsNucleus pulposus tissues were collected from specimens of normal and degenerative intervertebral discs from 9 surgical patients (mean age 33 years) admitted in the Department of Orthopedic Surgery, Navy General Hospital between January, 2016 and June, 2017. The nucleus pulposus cells (NPCs) were isolated and cultured, and the morphology of the ER was observed using transmission electron microscopy (TEM). The expression levels of 2 ER stressrelated molecules, namely glucoseregulated protein 78 (GRP78) and C/EBP homologous protein (CHOP), were analyzed using immunohistochemical assay, realtime PCR and Western blotting. ResultsTEM revealed obvious ER dilation and swelling in degenerative NPCs as compared with normal NPCs. Immunohistochemical assay and Western blotting showed obviously increased expressions of GRP78 and CHOP proteins in degenerative NPCs. GRP78 and CHOP mRNA expressions were also significantly increased in degenerative as compared with normal NPCs (2.471±0.53 vs 1.076±0.13, and 6.873±1.4 vs 1.09±0.21, respectively; P<0.05). ConclusionThe abnormal morphology of ER and increased expression of ER stress markers in degenerative NPCs suggest the involvement of ER stress in the development of NPC degeneration.


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Last Update: 2018-07-03