目的研究大鼠脑出血后Nrf2-ARE通路HO-1对出血灶周神经保护作用及其相关机制探讨。方法采用SD大鼠基底节自体股动脉血注射法建立脑出血模型,分4组:单纯脑出血(ICH)组、莱菔硫烷(SFN)组、维甲酸(RA)组、对照组,观察不同时间点大鼠神经功能评分,取脑组织行免疫荧光检查、Westernblot、RT-PCR检测Nrf2、HO-1、NF-KB、TNF-α表达。对所得数据进行统计分析,观察这些指标的变化。结果SFN组与ICH组比较,神经功能障碍明显减轻,出血灶周Nrf2因子、HO-1抗氧化蛋白表达均升高,于3d达高峰值,持续表达至7d;SFN组NF-KB、TNF-α表达下降;RA组大鼠死亡率最高,神经功能障碍较ICH组及SFN组均严重,Nrf2因子、HO-1抗氧化蛋白表达均较SFN组和ICH组低,持续性抑制作用可能持续7d左右,RA处理组NF.KB、TNF-α表达升高,炎性反应持续时间可能超过7d。结论RA抑制Nrf2解离及转入核,抑制Nrf2-ARE信号通路的抗炎性作用,SFN激活Nrf2-ARE信号通路可提高HO-1抗氧化酶表达,减轻脑出血后灶周炎性反应,具有神经保护作用,提示Nrf2-ARE信号通路将是治疗脑出血灶周炎性损伤的新方向。
Objective The aim of this study is to perform sulforaphane (SFN) activating the Nrf2-ARE signaling pathway and retinoic acid(RA) inhibiting the Nrf2-ARE signaling pathway to examine the neuroprotective effect of heme ox- ygenase(HO-1 )and to explore the underlying mechanisms on perifocal tissues after ICH. Methods SD rats with autolo- gous femoral arterial blood injection into the basal ganglia were applied to establish ICH models and were divided into four groups:ICH,SFN, RA and DMSO group. We observe neurological score of the rats in different groups at different time points and collect brain tissues for immunofluorescence,Western blot, and RT-PCR to detect the expression of Nrf2, HO-1, nuclear factor-KB(NF-KB) and tumor necrosis factor-a( TNF-α). And then,we observe the changes of the metrics by statis- tical analysis. Results In the SFN group, rats showed that neurological dysfunction was significantly reduced, and the ex- pressions of Nrf2 and HO-1 in tissues surrounding the hemorrhage were increased ,reached a peak value on day 3 ,followed by sustained expression until day 7. And the level of NF-KB and TNF-α were reduced compared to the ICH group. The RA group exhibited the highest mortality, more severe neurological dysfunction and lower levels of Nrf2 and HO-1 than the SFN and ICH groups. The inhibitory effect persisted for approximately seven days. Compared to the ICH group ,the NF-KB and TNF-~t expression in the RA groups was increased, and the inflammatory response persisted for more than seven days. Con- clusion RA inhibits Nrf2 dissociation and translocation into the nucleus, thereby suppressing the anti-inflammatory effect of the Nrf2-ARE signaling pathway. The activation of the Nrf2-ARE signaling pathway by SFN can elevate the expression of the antioxidant enzyme HO-1 ,reduce the perifocal inflammatory response after ICH,and thus play a neuroprotective role. The results suggest that the Nrf2-ARE signaling pathway may serve as a new target for treatment of perifocal inflammat