Objective: To establish an in vitro apoptosis model of rat intervertebral disc nucleus pulposus cells.
Method: In order to fully simulate the microenvironment of degenerative disc dystrophy, this experiment uses DMEM medium containing 1%, 3%, 5%, 8% and 10% fetal calf serum, and then cultures the disc nucleus pulposus cells. The highest pro-apoptotic concentration on the screen is used to detect the apoptotic rate of nucleus pulposus cells, the expression of apoptosis-related proteins Bax, bcl-2 and caspase-3, cell proliferation curves 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. Western blotting shows the expression of Bax and caspase-3. The enzyme in the 3% FBS group was significantly higher than that in the 10% FBS group, and the expression of bcl-2 was reduced. The results of the CCK-8 test showed that in the medium containing 3% FBS, the proliferation rate of nucleus pulposus cells increased with the increase of the apoptosis rate. The 3% FBS group was delayed, and the expression of FAS was significantly higher than that of the 10% FBS group.
Conclusion: 3% FBS induces apoptosis of nucleus pulposus cells, which may eventually lead to loss of cell function.