A Kinetic Study On The MRNA Expression Of Inflammatory Factors And Their Receptors In Activated Microglial Cells

Objective: To investigate the expression of the genes encoding MCP-1, FKN, CCR2, CX3CR1, TNF-a and IL-lpin the murine microglial cell line N9, and to detect the kinetic change of these factors in the N9 culture stimulated with LPS.Methods: The N9 cells were grown in DMEM supplemented with 5% heat-inactivated PCS. For in vitro experiments, N9 cells were incubated in the presence or absence of LPS or p-amyloid peptides. Culture supernatants and cells were isolated at different time intervals for the assays of ELISA and RT-PCR.Result: when LPS was added to cultured murine microglial cells, MCP-1 and FKN mRNA expression were significantly enhanced after a period of 12h . In contrast, LPS rapidly and drastically inhibited the expression of CCR2 and CX3CR1 after 4h, despite their presence at substantial levels in untreated murine microglial cells. On the other hand, LPS also induced the expression of inflammatory cytokines such as TNF-a and IL-1 p after 4h and 1 h, respectively.Conclusion: These results suggest that LPS regulates the expression of MCP-1, FKN, CCR2, CX3CR1, TNF-a and IL-lp in murine microglial cells and provide further insight into the microglial functions in the inflammatory diseases in the CNS.