红藻氨酸致癫痫持续状态大鼠海马neuropilin-2 mRNA及其蛋白表达的研究

Altered expression of neuropilin-2 mRNA and protein in hippocampus after kainic-induced status epilepticus rats

目的研究轴索导向分子NPN-2mRNA及其蛋白对癫痫持续状态(SE)后大鼠海马内神经纤维外向性生长和突触重建中的调控作用。方法采用侧脑室内注射红藻氨酸(KA)制作TLE大鼠模型,用Nissl染色、原位杂交和免疫组织化学的方法,分别检测致SE后1d、1w、2w、3w、4w大鼠海马齿状回(DG)、CA1区、CA3区、门区神经元丢失程度以及NPN-2mRNA及其蛋白的表达。结果 KA致SE后1d开始出现神经元丢失,至4w神经元丢失明显增多。KA致SE后1d,NPN-2mRNA及其蛋白在DG和CA1区表达明显下降,持续至3w(P<0.01),4w恢复至正常(P>0.05);NPN-2mRNA及其蛋白在门区、CA3区表达实验组与对照组无明显差别(P>0.05)。结论 KA致SE后,海马DG及CA1区神经元下调NPN-2mRNA及其蛋白的表达,促进DG及CA1区神经纤维外向性生长和突触的重建。

Objective To study the guiding fuctions of axon guidance molecules,NPN-2 in axonal sprouting outgrowth and synaptic reorganization in hippocampus by detecting it＇s mRNA and protein expression in rats after kainic acid （KA）-induced status epilepticus （SE）.Methods Adult rats were made to be a model of SE by intraventricular injection of KA.At 1d,1w,2w,3w and 4w after KA-induced SE,neurons loss were detected by Nissl staining,NPN-2 mRNA and protein expression in the dentate gyrus （DG）,CA1,CA3 and hillus regions of hippocampus were studied by in situ hybridization and immunohistochemistry.Results From the first day after KA-induced SE,neurons loss had been detected and increased for 4 weeks.On 1d after KA-induced SE,NPN-2 mRNA and protein expression decreased in the DG and CA1 region（P0.01）,and lasted for 3w,then increased in 4w（P0.05）.NPN-2 mRNA and protein expression had no difference in CA3 and hillus comparaed to the controlled group（P0.05）.Conclusions Those findings suggest that neurons in gyrus and CA1 region in hippocampus may down-regulate the NPN-2 mRNA and protain expression and thereby contribute to axonal sprouting outgrowth and synaptic reorganizating in hippocampus.