Regulation Of Phenotype By Dibutyryl-cAMP In Irradiation-stimulated Murine BV2 Microglial Cells

AIMSThe aim of the present study was to determine the role of dibutyryl-cAMP on cell phenotype in a murine macroglial cell line (BV-2cells) stimulated by irradiation.METHORDSBV-2 cells were pretreated with db-cAMP for 30 min, with concentration of 0μM, 10μM, 30μM, 100μM respectively. Then cells were irradiated with a single dose of 10Gy, 1h, 3h, 6h, 12h, 24h, 48h later, supernatants and cells were collected. ELISA was used to determine the concentrations of TNF-α, IL-12, IL-13, IL-10 in the supernatants. and iNOS, COX-2, IL-12, IL-13, IL -10 mRNA expression in microglia were detected by fluorescence quantitative PCR.RESULT1.The concentrations of TNF-αand IL-12 in the supernatants increased significantly after irradiation, but no significant changes were observed in IL-13 and IL-10 .2.Radiation led to significant increases in gene expression of the proin?ammatory cytokines IL-12, iNOS and COX-2 postirradiation, while IL-13 and IL-10 mRNA had no such changes.3.Db-cAMP dramatically decreased the concentrations of TNF-αand IL-12 in the supernatants of the radiation-activated BV-2 cell, but increased IL-10,IL-13 concentrations significantly, in a dose and time dependent way.4.Db-cAMP downregulated the level of iNOS, COX-2, IL-12mRNA in the radiation-activated BV-2,but upregulated IL-10, IL-13mRNA level, which also in a time and dose dependent manner. CONCLUSIONIronizing radiation could induce BV-2 cells to be a M1 microglia, expressing high level of pro-inflammatory cytokines such as TNF-α, IL-12, iNOS, and COX-2. Db-cAMP could downregulate the expression of pro-inflammatory cytokines, but significantly increased the expression of anti-inflammatory factor IL-10 and IL-13, turn the M1 microglia into the M2 microglia.