实验性变态反应性脑脊髓炎大鼠发病中脑组织血红素氧合酶-1基因和蛋白表达的动态变化

Dynamic changes of heme oxygenase-1 protein and mRNA in the brains of rats with experimental allergic encephalomyelitis

为探讨脑组织血红素氧合酶-1(heme oxygenase-1, HO-1)对实验性变态反应性脑脊髓炎(experimentalallergic encephalomyelitis,EAE)的作用, 分别应用逆转录-聚合酶链反应(RT-PCR)和免疫组化技术测定了豚鼠脊髓生理盐水匀浆+完全福氏佐剂诱导EAE大鼠1、7、14、21 d 时, 脑组织HO-1 基因和蛋白表达的动态变化, 并观察与症状之间的关系。结果显示: 对照组大鼠脑组织仅有少量HO-1 基因和蛋白表达; 诱导EAE 后, 伴随着大鼠EAE 症状及脑组织病理损伤的出现和进行性加重, 脑组织HO-1 基因和蛋白表达量逐渐增高。在豚鼠脊髓生理盐水匀浆+ 完全福氏佐剂诱导7 d 后, HO-1 mRNA上升至高峰。14 d 时, HO-1 蛋白表达至高峰, HO-1 阳性细胞主要位于脉络丛、穹隆下器、血管“套袖样”病灶的周围, 与 EAE 病变部位一致。此时大鼠的病情最重、体重减轻最显著、脑组织病理改变最明显。21 d 时脑组织HO-1 基因和蛋白表达量逐渐下降, 大鼠EAE 症状也逐渐减轻。应用HO-1 特异性抑制剂锡原卟啉-9 以抑制脑内HO-1 蛋白表达后, 大鼠EAE 症状和脑组织损伤明显减轻, 说明脑组织HO-1 的动态变化与EAE 症状及脑组织损伤密切相关。提示脑组织HO-1 基因和蛋白过表达对EAE 发病起着重要的作用, 应用 HO-1

In order toinvestigate the role of heme oxygenase-1 (HO-1) in the molecular mechanism of experimentalallergic encephalomyelitis (EAE), which was induced by guinea pig spinal cord homogenate + complete freund adjuvant on Wistar rats, we observed the gene of HO-1 and its protein expression with reverse transcriptase polymerase chain reaction(RT-PCR) and immunohistochemistry 1, 7, 14, and 21 d after EAE induction in rats. The relationship between HO-1 and the symptoms of EAE was also observed. The results showed that the levels of HO-1 mRNA and its protein expression were very low in the brains of the control group, whereas they were enhanced gradually with pathological course in the brain and onsets of symptoms, signs of EAE. On day 7, the level of HO-1 mRNA reached the peak, but the expression level of HO-1 protein in the brains reached the peak on day 14. The immunoreactive cells of HO-1 were mainly located at the choroid plexuses and subfornical organ (SFO), as well as in regions around the “sleeve-like” lesion foci, all of which were coincident with the locations of lesions of EAE. The levels of HO-1 mRNA and its protein expression were lowered gradually on day 21, which were in parallel with the severities of symptoms and signs of EAE. After a specific inhibitor of HO-1, Snpp-9, was applied , both of the symptoms and pathological lesions of EAE in the rat brains were mitigated markedly. Therefore, these results may suggest that the dynamic changes of HO-1 mRNA and its protein expression are in parallel with the changes of symptoms and pathological lesions of EAE in the brain. In conclusion, the levels of HO-1 mRNA and its protein expression in brains may play an important role in the pathogenesis of EAE, and application of inhibitors of HO-1 may be one of the potential therapeutic ways for the prevention and treatment of EAE.