Abstract:Objective To develop an apoptosis model of nucleus pulposus cells in cell culture. Methods To mimic the nutrient-deficient microenvironment of degenerative intervertebral disc,nucleus pulposus cells derived from infant SD rat disc were cultured under serum limiting conditions. Nucleus pulposus cells were cultured in culture medium containing 1%, 3%, 5%, 8% and 10% fetal bovine serum(FBS) respectively to select the optimum FBA concentration.Apoptosis was assessed by flow cytometry, Western blot,cell counting kit, and immunofluorescence technique.Results The flow cytometry revealed that apoptosis rate of the nucleus pulposus cells increased with decreasing concentration of FBS, and 3%FBS used in the experimental group was the most effective concentration to induce apoptosis(P<0.05). Western blot demonstrated significantly higher expression of Bax and caspase-3 enzyme in the 3%FBS group than in the 10%FBS group,while bcl-2 activity decreased. The results of CCK-8 test indicated that the nucleus pulposus cells got slower proliferation in the medium containing 3%FBS.Immunofluoresence analysis showed that FAS expression was significantly higher in the 3%FBS group than in the 10%FBS group. Conclusions 3%FBS condition may induce apoptosis in the nucleus pulposus cells and compromise the cell function to induce intervertebral disc degeneration.The caspase family should be involved in the process.