BDNF,NGF和NT-3的mRNA和蛋白在猫左侧腰第六背根节共表达的不同方式(英文)

Different types of coexpression of BDNF, NGF and NT-3 mRNA and proteins in the left sixth lumbar dorsal root ganglion of cats

本实验研究了脑源性神经营养因子(brain derived neurotrophic factor,BDNF),神经生长因子(nerve growth factor,NGF)和神经营养因子-3(neurotrophin-3,NT-3)的mRNA和蛋白在猫左侧腰第六背根节(dorsal root ganglion,DRG)共表达的不同方式,并探讨了共表达的机制,为阐明神经营养因子的表达与脊髓可塑性的关系提供依据。本实验所使用的为未接受任何处理的健康猫。猫的左侧腰第六DRG被取出,行免疫组织化学染色与原位杂交方法结合的双重标记,确定是否有BDNF,NGF和NT-3的蛋白与mRNA共表达。实验结果显示BDNF,NGF和NT-3的蛋白与mRNA在猫DRG均有表达,但这三种神经营养因子mRNA和蛋白共表达的方式是不同的。免疫组化结果显示:BDNF阳性产物主要分布于细胞质和细胞核,细胞核的染色颜色较细胞质浅;NGF阳性产物主要分布于细胞核;NT-3阳性产物主要分布于细胞质。原位杂交结果显示:BDNF和NGF阳性信号主要分布于细胞质;NT-3阳性信号在细胞质和细胞核都有分布。由此可见,BDNF,NGF和NT-3的mRNA和蛋白在猫左侧腰第六DRG有不同的共表达方式,提示它们可能存在与脊髓可塑性有关的自分泌和/或旁分泌机制。

The present study investigated different types of coexpression of brain derived neurotrophic factor （ BDNF）, nerve growth factor （NGF） and neutrophin-3 （NT-3） mRNA and/or proteins in the left sixth lumbar dorsal root ganglion （DRG） of cats and discuss the mechanism of coexpression in order to provide foundation for elucidating the relationship between the expression of neurotrophic factors and spinal cord plasticity. The cats used in this study were normal animals without any interventional treatment. They were subjected to remove of the left L6 DRG and their DRG were processed for immunohistochemistry and in situ hybridization double staining to observe whether there are coexpression of mRNA and proteins of BDNF, NGF and NT-3. The results showed that the proteins and mRNA of BDNF, NGF and NT-3 were all expressed in the DRG of cats, but the types of coexpression of mRNA and proteins were different and diverse among these three neurotrophic factors. The results of immunohiatochemistry showed that BDNF immunoreaetivities were mainly observed in the cytoplasm and nucleus, and the staining of nucleus was weaker than that of cytoplasm; NGF immunoreaetivities were mainly observed in nucleus while NT-3 mainly in cytoplasm. The results of in situ hybridization showed that BDNF and NGF positive signals mostly distributed in the cytoplasm, NT-3 positive signals were observed in both the cytoplasm and nucleus. Our results suggest that the proteins and mRNA of BDNF, NGF and NT-3 have different types of coexpression which indicate they may have autocrine and/or paracrine mechanism contributing to the plasticity of spinal cord in the left L6 DRG of cats.