title: Rabbit annulus fibrosus cell apoptosis induced by mechanical overload via a mitochondrial apoptotic pathway.
abstract: In order to investigate the apoptotic pathway of rabbit annulus fibrosus (AF) cells induced by mechanical overload, an experimental air-pressure model was established in this study to pressurize the rabbit AF cells in vitro. Cells were randomly divided into five groups in which the cells were exposed to a continuous pressure of 1.1 MPa for different lengths of time (0, 5, 12, 24 and 36 h). The cell proliferation and apoptosis were detected by cell counting kit-8 (CCK-8) assay and flow cytometry; the alterations in mitochondrial membrane potential were measured by fluorescence microscopy and fluorescence spectrophotometer; the activities of caspase-8 and 9 were determined by spectrophotometry. The results showed that after the cells were subjected to the pressure for 24 or 36 h, the cell proliferation was inhibited; the ratio of cell apoptosis was increased; the mitochondrial membrane potential was decreased; the activity of caspase-9 was enhanced; no activity changes were observed in caspase-8. The results suggested that treatment with a pressure of 1.1 MPa for more than 24 h can lead to the proliferation inhibition and the apoptosis of rabbit AF cells in vitro, and the mitochondrial-dependent pathway is implicated in the pressure-induced AF cell apoptosis.
authors.affiliation: Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China. xiemao886@163.com
authors.forename: Mao
authors.initials: M
authors.lastname: Xie
authors.forename: Shuhua
authors.initials: S
authors.lastname: Yang
authors.forename: Hein Latt
authors.initials: HL
authors.lastname: Win
authors.forename: Liming
authors.initials: L
authors.lastname: Xiong
authors.forename: Jijun
authors.initials: J
authors.lastname: Huang
authors.forename: Jianguo
authors.initials: J
authors.lastname: Zhou
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D007403:Intervertebral Disc / Q000166:cytology / Q000473:pathology*; D053078:Membrane Potential, Mitochondrial / Q000502:physiology; D008928:Mitochondria / Q000502:physiology*; D011817:Rabbits; D015398:Signal Transduction; D013314:Stress, Mechanical