Objective: To establish an in vitro apoptosis model of rat nucleus pulposus cells.
Method: In order to completely simulate the microenvironment of degenerative disc dystrophy, this experiment used DMEM medium containing 1%, 3%, 5%, 8% and 10% calf fetal serum. Used for culturing and screening the nucleus pulposus cells of the intervertebral disc. The optimal pro-apoptotic concentration is used to detect the apoptosis rate of nucleus pulposus cells, the expression of apoptosis-related proteins Bax, bcl-2 and caspase-3, cell proliferation curve and immunofluorescence analysis.
Result: The apoptosis rate of nucleus pulposus cells measured by flow cytometry increased with the decrease of fetal bovine serum (FBS) concentration, and 3% FBS was the most effective concentration for inducing apoptosis. Westernblot shows the expression of Bax and caspase-3 enzymes. In the 3% FBS group, the expression of bcl-2 was significantly higher than that of the 10% FBS group, and the expression of bcl-2 was decreased; the CCK-8 test results showed that the apoptosis rate in the medium containing 3% FBS increased.
The results showed that the proliferation rate of nucleus pulposus cells increased. The expression of FAS in the 3% FBS group was significantly higher than that in the 10% FBS group. Conclusion: 3% FBS induces nucleus pulposus cell apoptosis, which may eventually lead to the loss of cell function.