CAJ | 학술논문

目的探讨从血循环中渗入到脑内的自体内源性免疫球蛋白G (IgG)对外周脂多糖(LPS)刺激引起的中枢神经系统内Toll 样受体4 (TLR4)表达的作用.方法将SD大鼠20只随机分为4组,每组5只.LPS+生理盐水组:腹腔注射LPS 100μg/kg,6h后尾静脉给予生理盐水15μg/kg;AD组:尾静脉给予盐酸肾上腺素(AD)15μg/kg;LPS+AD组:先腹腔给予LPS,6h后静脉注射AD;对照组大鼠静脉注射生理盐水作为对照.最后一次注射后30 min处死动物,取脑,分别用免疫荧光染色和RT-PCR方法检测脑内TLR4的表达. 结果　免疫荧光染色显示,单独给予AD的动物中IgG免疫阳性产物呈斑片状分布于脑实质. LPS+生理盐水组的IgG免疫阳性产物仅限于血管周围;在LPS+AD组,IgG渗出区域内可见TLR4免疫阳性产物与小胶质细胞标志物Iba-1共存,双标的细胞分散于脑实质及血管附近,而LPS+盐水组TLR4阳性细胞呈内皮细胞样.RT-PCR结果显示,LPS+AD组TLR4的表达显著高于LPS+生理盐水组、AD单独注射组以及生理盐水对照组. 结论大鼠血循环中的IgG渗入脑内可促进外周LPS引起的脑内TLR4表达.
목적 탐토종혈순배중삼입도뇌내적자체내원성면역구단백G (IgG)대외주지다당(LPS)자격인기적중추신경계통내Toll 양수체4 (TLR4)표체적작용.방법 장SD대서20지수궤분위4조,매조5지.LPS+생리염수조:복강주사LPS 100μg/kg,6h후미정맥급여생리염수15μg/kg;AD조:미정맥급여염산신상선소(AD)15μg/kg;LPS+AD조:선복강급여LPS,6h후정맥주사AD;대조조대서정맥주사생리염수작위대조.최후일차주사후30 min처사동물,취뇌,분별용면역형광염색화RT-PCR방법 검측뇌내TLR4적표체. 결과　면역형광염색현시,단독급여AD적동물중IgG면역양성산물정반편상분포우뇌실질. LPS+생리염수조적IgG면역양성산물부한우혈관주위;재LPS+AD조,IgG삼출구역내가견TLR4면역양성산물여소효질세포표지물Iba-1공존,쌍표적세포분산우뇌실질급혈관부근,이LPS+염수조TLR4양성세포정내피세포양.RT-PCR결과현시,LPS+AD조TLR4적표체현저고우LPS+생리염수조、AD단독주사조이급생리염수대조조. 결론 대서혈순배중적IgG삼입뇌내가촉진외주LPS인기적뇌내TLR4표체.
Objective To investigate the effect of immunoglobulin G (IgG) extravasated from blood circulation on the expression of toll-like receptor 4 (TLR4) induced by peripheral lipopolysaccharide (LPS) in rat brain. Methods The rats were divided into four groups in random, 5 rats in each. Group one received LPS 100μg/kg by intraperitoneal administration, normal saline was given by intravenous injection 6 hours later; group two was injected with adrenalin (AD) 15μg/kg intravenously; group three was treated with LPS intraperitoneally, AD was injected 6 hours later; group four was injected normal saline intravenously as control. For all groups, the animals were sacrificed 30 min after the last injection, and the brains were taken for investigation of the TLR4 expressions by immunofluorescence staining and RT-PCR. Result Immunofluorescence staining showed that IgG immunoreactive product was patch-like, distributed in the brain parenchyma in all the animals that received AD. In the LPS+normal saline group, IgG was found merely around the blood vessels. Meanwhile, in LPS+AD animals, TLR4 immunoreactive product coexisted with microglia marker Iba-1 within the IgG extravasated area. The double-labeled cells dispersed in the brain parenchyma and near to the cerebral vessels. In the LPS+saline group, TLR4 positive cells were endothelial-like. RT-PCR results indicated that the expression level of TLR4 in the LPS+AD group were significantly higher than that in the LPS+saline group or AD group or the saline control (P<0.01). Conclusion Extravasated circulating IgG may enhance the TLR4 expression in the rat brain induced by peripheral LPS.