EAE大鼠SFO中NF-kB、HO-1蛋白表达的相关性

目的探讨实验性自身免疫性脑脊髓炎(EAE)时,大鼠核转录因子-κB(NF-κB)、血红素氧合酶-1(HO-1)在穹隆下器(SFO)中的变化,为证明SFO是感受外周信息物质的早期位点之一提供依据。方法分别用HE染色和免疫组化双色标记技术,观察了完全福氏佐剂+豚鼠脊髓匀浆(CFA-GPSCH)诱导大鼠EAE1d、7d、14d、21d时SFO部位HO-1、NF-κB蛋白表达的动态变化,并分析了与症状之间的相关性。结果对照组大鼠脑仅有少量HO-1、NF-κB蛋白表达;实验组大鼠诱导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,其HO-1、NF-κB蛋白表达量逐渐增高;在诱导后1d,SFO部位即出现HO-1/NF-κB阳性细胞表达,而其他脑区变化不明显;7d时进一步增多;14d时,HO-1+/NF-κB+细胞至高峰,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EAE病情最重、体重减轻最显著、脑组织病理改变最明显;21d时脑组织HO-1+/NF-κB+细胞逐渐下降,大鼠EAE症状也逐渐恢复。应用NF-κB特异性抑制剂PDTC后,HO-1+/NF-κB表达明显减少,大鼠EAE症状和脑组织病变明显减轻,说明NF-κB水平的高低可以调节HO-1的活性及其生物学作用。结论SFO可能是外周信息物质向中枢神经系统传递的重要而早期的位点之一。

The relation of activated nuclear factor-kappa B and heme oxygenase-1(HO-1) in SFO of rat-brains with experimental autoimmune encephalomyelitis

Objective To observe the dynamic changes of heine oxygenase-1 （ HO-1 ） and nuclear factor kappa B （NF-KB） protein express in subfornical organ in rats with experimental autoimmune encephalomyelitis （EAE） to confirm that SFO is one of the sites for blood-bearing signaling molecules entering into brain. Methods EAE was induced by CFA-GPSCH on Wistar rats, we observed the levels of HO-1 and NF-KB protein expression with immunohistochemistry, meanwhile, the pathology were observed on 1 d, 7d, 14d, and 21d after EAE induction in SFO of rats. The relationship of HO-1 and NF-KB to symptoms of EAE was also investigated. Results The expression levels of HO-1 and NF-KB 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 1 d after induction of EAE, positive ceils of HO-1 ^＋ / NF-KB ^＋ were observed at SFO, but the labeled cells were rarely seen in the other brain regions. On 7d, the HO-1 ＋/NF-KB^＋ ceils increased markedly. On 14d the levels of HO-1 and NF-KB protein expression in the brains reached the peak, the positive cells of HO-1 ^＋ / NF-KB ^＋ were mainly located at the choroid plexuses and SFO, as well as the regions around “sleeve-like” lesion loci, all of which were coincident with the locations of lesions of EAE. The changes of incidence, symptom, reduction of the body weight, and pathology lesions of EAE in rat brains were the most significant. On 21d, the levels of HO-1 and NF-KB protein expression reduced gradually, which was in parallel with remitted symptoms of EAE. When a specific inhibitor of NF-KB, PDTC, was applied, the symptoms and pathological lesions of EAE in brains were mitigated markedly. Conclusion SFO may be one of the earliest sites for blood-bearing signaling molecules entering into brain.