Establishment of lipopolysaccharide induced microglial inflammation model

OBJECTIVE To establish an in vitro inflammatory model of BV2 by observing the activity,the release amount of NO and the expression of inflammatory factors of microglial cells(BV2)induced by lipopolysaccharides(LPS).METHODS BV2 was routinely cultured in vitro.Cell viability was measured by CCK-8 meth⁃od.And by drew cell growth curve to determine the logarithmic growth cycle of the cells.After 24 h of routine culture,BV2 were induced by adding different concentrations of LPS(0.1,1.0 and 10.0 mg·L-1)for 4,8,12,24 and 48 h,respectively.Meanwhile,the morphological changes of BV2 were observed under inverted microscope to compare the activation degree of microglia at dif⁃ferent time and concentration.Cell activity and nitric oxide(NO)level were determined by CCK-8 and Griess method respectively,which could help to determine the optimal concentration and time of modeling.Finally,It were determined by ELISA that the concentrations of tumor necrosis factorα(TNF-α),interleukin-6(IL-6)and IL-1βin supernatant of LPS 1 mg·L-1 culture for 24 h.RESULTS BV2 were in logarithmic growth phase for 1 to 3 d after subculture.LPS 1 mg·L-1 induced BV2 for 24 or 48 h which could increase the release amount of NO significantly(P<0.05).In order to save time,LPS induced BV2 for 24 h were selected for subsequent experiments.Microglial cells in resting state were observed to be elongated spindle shape under inverted micro⁃scope.After LPS activation,the cell body became larger and the branching processes shrank back,presenting an amoeba-like appearance.ELISA results showed that the concentrations of TNF-α,IL-6 and IL-1βin supernatant of LPS 1 mg·L-1 cultured for 24 h were significantly increased which compared with the control group(P<0.05).CONCLUSION LPS could induce the activation of BV2 and up-regulate the level of inflammatory factors.The optimal condition for establishing stable BV2 microglial inflammatory model was used LPS 1 g·L-1 induced for 24 h.