鸡源Wnt3a融合蛋白表达载体的构建及其对鸡胚脊髓神经前体细胞增殖和轴突形成的影响  

Construction of Wnt3a fusion protein vector and its effect on the proliferation and axon formation of neural precursor cells during the chick embryonic spinal cord development

作　　者：李秋玲[1] 杨慈清[1,2] 张必超[1] 朱少义 林俊堂[1,2] 

机构地区：[1]新乡医学院生命科学技术学院,河南新乡453003 [2]河南省医用组织再生重点实验室,河南新乡453003

出　　处：《解剖学报》2017年第1期7-13,共7页Acta Anatomica Sinica

基　　金：河南省科技厅基础与前沿技术研究项目(162300410134;162300410232);河南省科技创新人才项目(14HASTIT032);河南省国际科技合作项目(144300510054);新乡医学院研究生科研创新支持计划项目(YJSCX201513Y)

摘　　要：目的构建鸡源Wnt3a融合蛋白真核表达载体(pCAG-MCs-Wnt3a-EGFP),并探讨其在鸡胚脊髓发育过程中超表达后对神经前体细胞增殖及轴突形成的影响。方法利用分子生物学手段,提取鸡胚脊髓总RNA并获得Wnt3a片段,将其克隆到pCAG-MCs-EGFP载体中构建pCAG-MCs-Wnt3a-EGFP表达载体。在鸡胚发育至2.5~3d(E2.5~E3)时,利用鸡胚活体电转技术将pCAG-MCs-Wnt3a-EGFP(实验组)和pCAG-MCs-EGFP(对照组)质粒分别转入鸡胚脊髓,E4时取材切片,每组5个胚胎组织,采用免疫荧光染色技术检测Wnt3a和增殖细胞核抗原(PCNA)蛋白表达变化分析Wnt3a与细胞增殖间的关系,根据载体自发绿色荧光蛋白(GFP)观察脊髓神经前体细胞轴突生成情况。结果 pCAG-MCs-Wnt3a-EGFP表达载体基因测序结果与Gene bank中基因序列一致,将pCAGMCs-Wnt3a-EGFP导入鸡胚脊髓中发现绿色荧光。在脊髓组织切片水平上,免疫荧光染色结果表明,Wnt3a在鸡胚脊髓中能够超表达。Wnt3a超表达后,与对照组比较,含有轴突的神经元数量明显减少(n=3,P<0.01),而PCNA的表达量显著增加(n=3,P<0.01)。结论成功构建了鸡源性Wnt3a融合蛋白真核表达载体,并证实Wnt3a在鸡胚发育过程中促进神经前体细胞的增殖并抑制轴突的形成。Objective To construct a eukaryotic vector of chicken-derived Wnt3 a tagged with EGFP（pCAG-MCsWnt3a-EGFP） and investigate the influence to the proliferation and axonal formation of neural precursor cells when Wnt3 a was overexpressed during the development of chick embryonic spinal cord.Methods Wnt3 a gene was amplified from the total RNA obtained from chick embryonic spinal cord using molecular techniques,then connected with pCAG-MCs-EGFP to construct pCAG-MCs-Wnt3a-EGFP,which was identifled by digestion and genetic sequencing.At embryonic day（E） 2.5-3.0,pCAG-MCs-Wnt3a-EGFP（experimental group） and pCAG-MCs-EGFP（control group） were transfected into the chick embryonic spinal cord using in vivo electroporation,respectively.Samples were collected at E4（5 simples of each groups） and then conducted frozen section.The immunofluorescent staining was performed to detect the expression of Wnt3 a and proliferating cell nuclear actigen（PCNA） for analyzing the relationship between Wnt3 a and cell proliferation,and observe the axonal formation of neural precursor according to the green fluorescence of Wnt3 a protein.Results pCAGMCs-Wnt3a-EGFP was obtained and its gene sequencing was identical with the Gene bank.Green fluorescence wasobserved at E4 after pCAG-MCs-Wnt3a-EGFP transformed to chick spinal cord.In transversal section of chick embryonic spinal cord,the results of immunofluorescent staining showed Wnt3 a was successfully overexpressed.Meanwhile,the amount of neurons projecting axons was dramatically decreased（n = 3,P 〈 0.01）,compared to the control group,concomitant with the significant elevation of PCNA level（n = 3,P 〈 0.01）.Conclusion pCAG-MCs-Wnt3a-EGFP is successfully constructed and our study confirmed that Wnt3 a plays a vital role in the proliferation and axonal formation of neural precursor cells in the developing chick spinal cord.

关 键 词：WNT3A 增殖 轴突形成 活体原位电转 免疫荧光 鸡胚 

分 类 号：Q954.48[生物学—动物学]