纤维粘连蛋白和凝集素受体在高温致神经管畸形中作用的研究

STUDY OF THE RULES OF FIBRONECTIN AND IECTIN BINDING SIYES IN DEVELOPMENT OF THE NEURAL TUBE DEFECTS INDUCED BY HYPERTHERMIA

采用免疫组织化学方法探讨了高温致神经管畸形的分子机理。雌性金黄地鼠交配后将实验组给予高温处理，并与对照组一起在相应时间取材，做石蜡切片。各组部分切片用ＡＢＣ法显示纤维粘连蛋白（ＦＮ）；其余切片用刀豆凝集素（ＣｏｎＡ）、花生凝集素（ＰＮＡ）、麦胚凝集素（ＷＧＡ）和荆豆凝集素（ＵＥＡ）作为分子探针，用亲合细胞化学染色，对神经上皮及基膜、脊索和周围间充质的基质粘着分子（ＦＮ）和相应糖基即凝集素受体进行定性、定位观察。结果显示：１．实验组各组胚胎的ＦＮ染色均有不同程度的减弱。２．ＰＮＡ和ＣｏｎＡ染色比对照组显著增强，ＷＧＡ和ＵＥＡ染色差异无显著性。提示在神经管发育过程中，高温可使神经上皮及其基膜和周围间充质的ＦＮ降低，同时增加了神经上皮细胞表面的ＰＮＡ和ＣｏｎＡ的受体糖蛋白数量，破坏了细胞粘着和基质粘着之间的协调关系，从而干扰了神经上皮细胞的正常增殖、迁移和粘着过程。

Mated female hamsters were immersed partially in water bath at 42℃ for 20 minutes on 8th of gestation and dissected at 14,24,48,72,96 hours after treatment.Part of sections were stained with immunohistochemical ABC methods for observation of quality and distribution of FN in the embryonic neural epithelium and its basement membrane,natochord and the mesenchyma around neural tube.The others were stained with ConA、WGA、PNA and UEA,Which were used as molecule probes to explore the quality and distribution of the related oligosaccharides on the cell membrane.The results showed 1.stain intensity for FN in each treated group is weaker than that in the controls.2.the staining of ConA and PNA in each treated group was more intense than that in the controls,but no difference in staining for UEA and WGA between the treated and the controls.It is indicated that hyperthermia could reduce the substrate adhesion molecules(FN)in quantity and make an increase in amoun of glycoproteins containing ConA and PNA binding receptors on the cells of neural epithelium during neurulation,resulting in interference of the coordination between the cell cell adhesion and cell substrated adhesion and disturbing the normal proliferation and migration of the neural epithelium,which induce neural tube defects.