Department of Neurology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China.
Neurosci Lett. 2013 Oct 11;553:72-7. doi: 10.1016/j.neulet.2013.08.020. Epub 2013 Aug 21.
Sirtuin1 (SIRT1) has protective effects in some neurodegenerative disease models, but it is not clear whether SIRT1 play the same role on inflammation-mediated Parkinson's disease (PD) models. In this study, we firstly established an inflammation environment by stimulating microglial BV-2 cells with the inflammatory agent lipopolysaccharides (LPS), which demonstrated by increasing of the levels of TNF-a, and IL-6 in cultured medium. Then we exposed PC12 cells (a model of catecholaminergic neuronal cells) with the supernant from LPS stimulated BV-2 cells (activated BV-2). PC12 cell apoptosis and SIRT1 involved protection were investigated. The results indicated that treatment with LPS caused significant decrease in SIRT1 expression in activated BV-2 cells, and increased the levels of TNF-a and IL-6, as measured by ELISA, whereas resveratrol (a known SIRT1 activator) suppressed this effect, which was conversely strengthened by sirtinol (a SIRT1 inhibitor), suggesting that SIRT1 may be involved in regulating proinflammatory cytokines from microglial activation. Further, we found that factors derived from activated microglia significantly decreased the level of deacetylation of p53 by reducing the expression of SIRT1, an effect that increased the apoptosis of PC12 and reduced cell viability. The addition of resveratrol could protect PC12 cells from inflammation-mediated damage above-mentioned, while nicotinamide (another SIRT1 inhibitor) treatment had the opposite effect of resveratrol. Together, these data suggests that: SIRT1 inhibits LPS-mediated proinflammatory cytokines release in microglia, and circumvents dopaminergic neurons injury induced by activated microglial-derived factors via p53-caspase-3-dependent mechanism of apoptosis. Thus, upregulation of SIRT1 provides a promising research field for therapeutic intervention in neuroinflammation diseases.
Sirtuin1(SIRT1)在一些神经退行性疾病模型中具有保护作用,但 SIRT1 是否在炎症介导的帕金森病(PD)模型中发挥相同作用尚不清楚。在这项研究中,我们首先通过用炎症剂脂多糖(LPS)刺激小胶质细胞 BV-2 细胞来建立炎症环境,这通过培养物中 TNF-a 和 IL-6 水平的增加来证明。然后,我们将 PC12 细胞(儿茶酚胺能神经元细胞的模型)暴露于 LPS 刺激的 BV-2 细胞(激活的 BV-2)的上清液中。研究了 PC12 细胞凋亡和涉及 SIRT1 的保护作用。结果表明,LPS 处理导致激活的 BV-2 细胞中 SIRT1 表达显着降低,并通过 ELISA 测量增加了 TNF-a 和 IL-6 的水平,而白藜芦醇(已知的 SIRT1 激活剂)抑制了这种作用,而 Sirtinol(SIRT1 抑制剂)则相反增强了这种作用,表明 SIRT1 可能参与调节小胶质细胞活化的促炎细胞因子。此外,我们发现,来自激活的小胶质细胞的因子通过降低 SIRT1 的表达显着降低了 p53 的去乙酰化水平,从而增加了 PC12 的凋亡并降低了细胞活力。白藜芦醇的添加可以保护 PC12 细胞免受上述炎症介导的损伤,而烟酰胺(另一种 SIRT1 抑制剂)的处理则具有与白藜芦醇相反的作用。总之,这些数据表明:SIRT1 抑制 LPS 介导的小胶质细胞中促炎细胞因子的释放,并通过 p53-caspase-3 依赖性凋亡机制规避激活的小胶质细胞衍生因子诱导的多巴胺能神经元损伤。因此,SIRT1 的上调为神经炎症疾病的治疗干预提供了一个有前途的研究领域。