脑室注射Nogo-A抗体对HIBD新生大鼠脑组织神经细胞再生的影响

Effect of ventricle injection of Nogo-A antibody on neuronal regeneration following hypoxic-ischemic brain damage in the neonatal rat

摘要:

目的：Nogo-A对中枢神经轴突的生长具有很强的抑制作用，而Nogo-A特异性抗体IN-1能中和这种抑制性蛋白，从而促进损伤轴突的再生。该文旨在探讨脑室注射Nogo-A抗体（IN-1）对缺氧缺血性脑损伤（HIBD）新生大鼠脑组织神经细胞再生的影响。方法: 建立新生大鼠HIBD模型，随机分为IN-1组和人工脑脊液组，每组20只，前者脑室注射IN-1 10 μL，后者脑室注射人工脑脊液10 μL，另外选择20只新生大鼠为假手术组，只施行颈部手术分离颈总动脉，但不结扎，不做缺氧缺血处理。应用免疫组织化学ABC法结合图像分析研究其脑组织Nogo-A及GAP-43蛋白表达水平。结果:IN-1组新生鼠脑组织Nogo-A蛋白表达弱于人工脑脊液组，前者Nogo-A免疫组化阳性细胞数（28.61±1.70）也较后者（39.52±1.40）明显减少，两者比较差异具有显著性（P<0.01）；IN-1组Nogo-A免疫组化阳性细胞数明显少于假手术组（32.78±1.87），两者比较差异具有显著性（P<0.01）；而人工脑脊液组（39.52±1.40）明显多于假手术组（P<0.01）。IN-1组GAP-43蛋白的表达（31.14±1.88）强于人工脑脊液组（27.73±1.43），两组GAP-43免疫组化阳性细胞数比较差异具有显著性（P<0.01）；IN-1组及人工脑脊液组GAP-43免疫组化阳性细胞数明显少于假手术组（33.64±1.24），差异均有显著性（P<0.01）。结论: Nogo-A抗体可导致HIBD新生大鼠脑组织Nogo-A蛋白表达明显减少，对神经细胞再生的抑制作用减弱。而脑组织神经细胞GAP-43表达增强，提示神经细胞再生作用增强。［中国当代儿科杂志，2007，9（4）：301-304］

Abstract:

OBJECTIVE: Nogo-A antibody IN-1 can neutralize Nogo-A, a neurite growth inhibitory protein, promoting axonal regeneration following lesions of the central nervous system (CNS) in adult rats. This study aimed to examine the effect of ventricle injection of Nogo-A antibody on neuronal regeneration in neonatal rats following hypoxic-ischemic brain damage (HIBD). METHODS: A model of neonatal HIBD was prepared by the ligation of the left common carotid artery, followed by 8% hypoxia exposure. Forty HIBD rats were randomly given a ventricle injection of 10 μL Nogo-A antibody IN-1 (IN-1 group) or 10 μL artificial cerebrospinal fluid (artificial CSF group) (n=20 each). Another 20 neonatal rats were sham-operated, without hypoxia-ischemia, and were used as the controls. The levels of Nogo-A and GAP-43 protein in the brain were measured by immunohistochemistry. RESULTS: The number of immunohistory positive cells of Nogo-A in the brain in the IN-1 group (28.61±1.70) was obviously less than that in the artificial CSF (39.52±1.40) and the sham-operated groups (32.78±1.87) (both P<0.01). There were significant differences in the Nogo-A protein expression between the artificial CSF and the sham-operated groups (P<0.01). The GAP-43 protein expression in the IN-1 group (31.14±1.88) was noticeably higher than that in the artificial CSF group (27.73±1.43 ) (P<0.01). Both the IN-1 and the artificial CSF groups showed lower GAP-43 protein levels than the sham-operated groups (33.64±1.24) (both P<0.01). CONCLUSIONS: Nogo-A antibody can reduce the expression of Nogo-A protein in the brain and thus promote neuronal regeneration in neonatal rats following HIBD. An increased GAP-43 protein expression in the brain after Nogo-A antibody administration shows an enhanced neuronal regeneration in the neonatal rats following HIBD.［Chin J Contemp Pediatr, 2007, 9 (4):301-304］