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氧化应激是缺血再灌注后星形胶质细胞损伤和死亡的重要分子机制之一,可能成为有效的干预靶点。下述治疗策略可减轻缺血再灌注条件下产生的多种反应性氮氧化合物损伤。这种方法可通过使用化学试剂或适当条件促进转录活化因子NRF2从细胞浆转入细胞核,并与抗氧化基因反应位点结合,来诱导缺血再灌注后损伤细胞的Ⅱ期基因反应。本研究将验证如下假说:NRF2基因表达通路激活剂sulforaphane能对体外无氧无糖环境处理的培养皮质星形胶质细胞起神经保护作用。将皮质星形胶质细胞暴露于无氧无糖环境(OGD)4 h,于干预前48 h或干预后给予5μMsulforaphane(NRF2基因表达通路激活剂)培养48 h,两种培育条件下细胞死亡均明显减少。免疫细胞化学结果表明干预前给予sulforaphane处理,细胞中DNA/RNA氧化标志物8-hydroxy-2-deox-yguanosine的表达在恢复给氧4 h后降低,两种培育条件下胞浆内及胞核内NRF2的免疫反应均增强且NQO1(NRF2转录活化基因产物)的表达和酶活性均增强。本研究提示sulforaphane可通过激活NRF2抗氧化基因表达通路,减少体外缺氧再灌注后星形胶质细胞的死亡。
Oxidative stress is one of the important molecular mechanisms of astrocyte injury and death after ischemia-reperfusion, which may be an effective intervention target. The following treatment strategies can reduce a variety of reactive oxygen species generated under the conditions of ischemia-reperfusion injury. This method can induce the phase Ⅱ gene response of injured cells after ischemia-reperfusion by promoting the transfer of the transcriptional activator NRF2 from the cytoplasm to the nucleus using chemical reagents or appropriate conditions and binding to antioxidant gene response sites. This study will validate the hypothesis that sulforaphane, a NRF2 gene expression pathway activator, has neuroprotective effects on cultured cortical astrocytes treated in an oxygen-free and sugar-free environment in vitro. Cortical astrocytes were exposed to oxygen free and sugar free environment (OGD) for 4 h. 48 h before or 48 h after intervention, 5 μM sulfulfate (NRF2 gene expression pathway activator) obviously decrease. Immunocytochemistry results showed that sulforaphane treatment before intervention, the expression of DNA / RNA oxidative marker 8-hydroxy-2-deox-yguanosine decreased after 4 h recovery of oxygenation, both in the cytoplasm and nucleus The immune response to both NRF2 was enhanced and the expression and enzyme activity of NQO1 (NRF2 transcriptional activation gene product) increased. This study suggests that sulforaphane can reduce the death of astrocytes after hypoxia-reperfusion in vitro by activating the NRF2 antioxidant gene expression pathway.