Inhibitory effects of Tanshinone ⅡA on radiation-induced inflammatory response in microglia BV-2 cells / 中华放射医学与防护杂志

ABSTRACT

Objective To explore the inhibitory effects of Tanshinone Ⅱ A on the radiationinduced microglia activation and the possible mechanism.Methods Microglia cells BV-2 were irradiated with 2,4,8,16,and 32 Gy doses or sham-irradiated in presence or absence of 1.0 μg/ml Tanshinone Ⅱ A for 12 h,respectively.The effects of Tanshinone Ⅱ A on radiation-induced pro-inflammatory cytokines were evaluated using real-time PCR.The expression level of NF-κB p65 in cytoplasm and nucleus was measured by using Western blot.Immunofluorescence staining and confocal microscopy analysis were applied to detect the expression of γ-H2AX and p65 post-irradiation.Results The microglia cells were activated at 16,32 Gy post-irradiation.Radiation-induced release of the pro-inflammatory cytokines in BV-2 cells was detectable after irradiation.Tanshinone Ⅱ A decreased radiation-induced release of proinflammatory cytokines(t=5.56,P ＜ 0.05).Furthermore,western blotting showed that Tanshinone Ⅱ A could attenuate the nuclear translocation of NF-κB p65 submit post-irradiation.Immunofluorescence staining showed that γ-H2AX foci formation while p65 translocation into nucleus post-irradiation.Conclusions Tanshinone Ⅱ A exerts anti-inflammatory properties by suppressing the transcription of proinflammatory cytokine genes that might be associated with NF-κB signaling pathway.It is postulated that irradiation causes immediate cellular reaction and DSB triggers the molecular response which leads to NFκB pathway activation.