The Effect Of Cobalt And Chromium Ions On Monocyte-macrophage Cells: Expression Of RANK And Its Mechanism Of Experimental Study

Objective: Research the cytotoxicity of chromium (Cr3+) and cobalt(Co2+) ions and the mechanism of osteolysis after artificial joint replacement by RANK express in rats monocyte/macrophages(RAW264.7) stimulated with Co2+ and Cr3+Methods: Culture monocyte-macrophage cells in vitro. Monocyte-macrophage cells exposed to Co2+ and Cr3+ ions, The cell viability was assured by MTT test. The cells were divided into 5 groups, Group A:monocyte/macrophages; Group B: monocyte/macrophages + 500 mg/L Cr3+;Group C:monocyte/macrophages+500 mg/LCr3++20μmol/L SP600125; Group D:monocyte/macrophages + 10 mg/L Co2+ Group E:monocyte/macrophages + 10 mg/L Co2+ +20μmol/L SP600125 Then,Semi-quantitative reverse transcription PCR method was used to detect the level of RANK mRNA after 24 h and 48 h.Results Compared to the control, MTT test demonstrated that Co2+ and Cr3+ ions can both obviously decrease the cell viability of monocyte/macrophages. Cells exposed to Co2+ and Cr3+ ions, compared to the control(Group A), mRNA expression of RANK was both incresaed at 24 h and 48 h (P<0.05),and SP600125 (JNK Inhibitor) could inhibite cells to express of RANK mRNA in cells stimulated with Co2+ and Cr3+(P<0.05)Conclusion:Co2+,Cr+ ions have a cytotoxic effect on monocyte/macrophages and can stimulate the expression of RANK in monocyte/macrophages.In addition,metal ions could stimulate monocyte/macrophages to express RANK through JNK pathway.