[Release of TNF-alpha and activation of Caspase-3 during apoptosis of human mononuclear cell induced by metal ion].

OBJECTIVE

To observe the human mononuclear cell releasing TNF-alpha and the activation of Caspase-3 during apoptosis after stimulated by Co2+ and Cr3+, to discuss the mechanism of artificial joint wear production metal ion on aseptic loosening.

METHODS

CoCl2 powder and CrCl3 powder were dissolved by asepsis inject water, preparing solution for 10 mg/L and 500 mg/L, respectively. Mononuclear cells were acquired from peripheral blood, 4 x 10(6)/culture dish. According to the difference of culture solution, the cells were divided into 3 groups. Group A: mononuclear cell was culture with normal saline as control; group B: mononuclear cell was cultured with CoC2 solution; group C: mononuclear cell was cultured with CrCl3 solution. The production of TNF-alpha was assessed by ELISA, the activation of Caspase-3 was measured by colorimetric assay and the apoptotic cell was detected by TUNEL assays at 12, 24 and 48 hours after co-cultured respectively.

RESULTS

The concentration of TNF-alpha and the expression of Caspase-3 in groups B and C were higher than those in group A (P < 0.05), and reached the peak level at 24, 48 hours, respectively. The TUNEL positive cells were detected in the all groups, nucleus was pyknotic and darker-staining, cell body was crinkle and cell membrane was integrity. There were significant differences in the apoptosis rate between groups B, C and group A (P < 0.05). And the activation of Caspase-3 increased and had the positive correlation with the apoptosis rate (r = 0.765).

CONCLUSION

Co2+ and Cr3+ ions can stimulate human mononuclear cell to release TNF-alpha and induce human mononuclear cell apoptosis, which result in periprosthetic osteolysis and related to activation of Caspase-3.