Effects Of Macrophage Colony-Stimulating Factor On Protease Secretion From RAW264.7 Cell And Its Possible Mechanism

M-CSF is a growth factor that stimulates proliferation and differentiation of monocyte/macrophage-lineage cell. Concentrations of macrophage colony stimulating factor are abnormally increased in patients with severe unstable angina and acute coronary syndromes. M-CSF has been used as a predictive factor for long-term outcome of AS patients in clinic. However, whether the M-CSF has any internal association with other known AS-causing factors such as metalloproteinase 9 has not been evaluated.AIM: To investigate the possible effect of Macrophage colony-stimulating factor on protease secretion from RAW264.7 cell.METHORD: RAW264.7 mouse macrophage cell line was used. Gelatin zymographic analysis was used to determine MMP-9 activity. RT-PCR analysis was performed to evaluate MMP-9 expression at mRNA level. Western blotting was used to study p-ERK1/2 expression at protein level.RESULTS: Gelatin zymographic analysis revealed that MMP-9 activity was increased in the conditioned medium after 24-hour M-CSF exposure, but M-CSF had no effect on the enzymatic activity of previously secreted MMP-9. Reverse transcription polymerase chain reaction (RT-PCR) showed that M-CSF upregulated MMP-9 mRNA expression. Pre-treatment with PD98059 decreased the expression of p-ERKl/2 and the activity of MMP-9,but PD98059 had no effect on the enzymatic activity of previously secreted MMP-9. Furthermore, both the time-course and dose-responsiveness course of M-CSF on the expression of p-ERKl/2 were determined. The treatment of 250ng/ml M-CSF was found to be effective in upregulating p-ERKl/2 as early as 3min and leveling off at 20min. All...