Activation effect of β-amyloid on microglia in vitro

Objective To investigate the relationship between β-amyloid(Aβ) and microglia(MG) activation.Methods The survival rate,the morphological changes,the gene expression and release of proinflammatory cytokines IL-1β and IL-6 in cultured murine microglia BV-2 cells in response to Aβ in vitro were observed.The survival rate of BV-2 cells was assayed by MTT assay.IL-1β and IL-6 were examined by radioimmunoassay,IL-1β and IL-6 mRNA expression was analyzed by RT-PCR.Results At the doses studied,Aβ_(1-42) had no toxicity in BV-2 cells.BV-2 cells changed their morphology after treatment with Aβ_(1-42) at low doses(5-10 μmol/L),which was related to the aggregation of peptides.Aβ_(1-42) could induce the gene expression and secretion of IL-1β in a dose-and time-dependent manner,but did not trigger the production of IL-6.The aggregation of peptides was not necessary for the induction.Conclusions Aβ_(1-42) has no toxicity in BV-2 cells.On exposure to Aβ_(1-42),microglial cells exhibit morphological changes and secrete proinflammatory cytokines IL-1β,but there is difference between the pathways of these two actions.The morphological changes are relate to the aggregation of Aβ_(1-42),but it is not necessary for the induction of IL-1β.