SEDL基因突变致迟发性脊柱骨骺发育不良机制的初步研究  

A pilot study on the mechanism of spondyloepiphyseal dysplasia tarda caused by SEDL gene mutation

作　　者：夏欣一[1] 周玉春[1] 崔英霞[1] 周鑫[1] 魏莉[1] 戈一峰[1] 姚兵[1] 李晓军[1] 黄宇烽[1] 

机构地区：[1]南京大学医学院临床学院(南京军区南京总医院)解放军检验医学研究所中心实验科,南京医学博士210002

出　　处：《医学研究生学报》2010年第8期800-804,共5页Journal of Medical Postgraduates

基　　金：国家自然科学基金(30901652);江苏省科技厅生殖健康研究技术服务平台项目(BM2008151);南京军区南京总医院青年基金(2009Q047)

摘　　要：目的迟发性脊柱骨骺发育不良(spondyloepiphyseal dysplasia tarda,SEDT)是一种X线表现明显的X连锁骨发育不良疾病,主要特征包括不成比例的短躯干型矮身材、大关节发育不良以及胸腰椎椎体扁平。文中初步研究SEDL基因突变致SEDT的机制。方法将野生型SEDL基因及其突变型(c.370-371insA)重组真核表达质粒分别转染COS-7细胞,通过流式细胞仪检测转染效率,激光共聚焦显微镜下观察重组蛋白表达的亚细胞定位,应用透射电镜观察转染细胞的超微结构。结果野生型和突变型重组质粒的转染效率分别为47.51%和46.39%。野生型重组Sedl-in蛋白主要定位于核周,而突变型Sedlin蛋白则主要分布于细胞核以及部分在胞质表达。超微结构显示转染SEDL突变型重组质粒的细胞溶酶体显著增多。结论SEDL基因c.370-371insA突变导致Sedlin蛋白细胞定位的变化可能是SEDT发病的分子机制。Objective Spondyloepiphyseal dysplasia tarda（SEDT） is a radiologically distinct,X-chromosome linked primary skeletal dysplasia characterized by disproportionate short-trunked short stature,dysplasia of the large joints and flattened thoracic and lumber vertebral bodies.The authors aimed to investigate the mechanism of SEDT caused by SEDL gene mutation.Methods COS-7 cells were transfected with a wild type and mutant（c.370-371insA） eukaryotic expression vector previously constructed.Transfection efficiency was detected by flow cytometer.Recombinant protein expression and subcellular localization was examined by the confocal laser microscope.Ultrastructural changes of tranfected COS-7 cells were observed by transmission electron microscope（TEM）.Results Transfection efficiency of wild and mutant type plasmid were 47.51%and 46.39%,respectively.TEM micrograph of affected fetus showed a typical cartilage with large cytoplasmic inclusion bodies,formed by dilated rough endoplasmic reticulum,and relative paucity of collagen fibers in the extracellular matrix.Transient transfection studies revealed that the EGFP-tagged Sedlin localized to perinuclear structures.SEDL c.370-371insA mutation introduced into recombinant constructs led to the misplacement of the Sedlin primarily to the cell nucleus and partially to the cytoplasm.TEM observation revealed that the number of cytolysosome in the mutant cells increased significantly.Conclusion The changes of Sedlin subcellular localization caused by SEDL gene c.370-371insA mutation might underlie the mechanism of SEDT.

关 键 词：SEDL基因 重组表达 超微结构 迟发性脊柱骨骺发育不良 

分 类 号：R394.3[医药卫生—医学遗传学]