凝血因子Ⅺp.L424CfsX8突变蛋白结构与功能分析  

An analysis of the structure and function of mutant protein of coagulation factor

作　　者：李阳阳 李君 蔡晓晓 夏雯丽 杨丽红[2] LI Yangvang;LI Jun;CAI Xiaoxiao;XIA Wenli;YANG Lihong(Center of Laboratory Medicine,Wenzhou People’s Hospital,Wenzhou 325000,China;Center of Laboratory Medicine,the First Affiliated Hospital of Wenzhou Medical University,Wenzhou 325015,China)

机构地区：[1]温州市人民医院医学检验中心,浙江温州325000 [2]温州医科大学附属第一医院医学检验中心,浙江温州325015

出　　处：《温州医科大学学报》2024年第11期927-931,936,共6页Journal of Wenzhou Medical University

基　　金：温州市基础性科研项目(Y2023783)。

摘　　要：目的:对一个罕见F11基因杂合缺失突变进行致病机制研究。方法:分析该遗传性凝血因子XI(FXI)缺陷症先证者及父母的相关凝血试验和基因测序。构建FXI野生型和突变型质粒,并转染HEK293FT细胞。采用ELISA法和Westernblot法检测FXI蛋白的表达水平。结果:先证者的FXI活性(FXI:C)降低至3%,FXI抗原(FXI:Ag)降低至8.6%,其父母的FXI:C和FXI:Ag均下降至正常对照的一半左右。基因分析发现先证者F11基因第7号外显子存在杂合无义突变(c.738G>A,p.Trp228stop),以及第12号外显子存在杂合缺失突变(c.1325delT,p.L424CfsX8)。瞬时转染的HEK293FT细胞的体外研究结果显示,FXI-L424CfsX8突变体在细胞培养液和裂解液中,与野生型相比,FXI蛋白含量都明显下降(P<0.001)。结论:p.L424CfsX8杂合缺失突变与先证者FXI水平降低有关,该突变可能会导致细胞内外FXI蛋白含量均显著降低。Objective:To analyze the pathogenesis of a rare heterozygous deletion mutation of F11 gene.Methods:The blood clotting tests and gene sequencing of the progenitors of hereditary coagulation factorⅪ(FⅪ)deficiency and their parents were analyzed.FⅪwild-type and mutant expression plasmids were constructed and transfected into HEK293FT cells.The FⅪprotein expression level was evaluated by ELISA and Western blot.Results:The FⅪactivity(FⅪ:C)and FXI antigen(FⅪ:Ag)of the proband were decreased to 3%and 8.6%,respectively FⅪ:C and FⅪ:Ag of his parents were both reduced to about half the normal control levels.Genetic analysis showed that the proband had heterozygous mutations in exon 7(c.738G>A,p.Trp228stop)and heterozygous deletions in exon 12(c.1325delT,p.L424CfsX8).In vitro studies of transient transfected HEK293FT cells showed that the FⅪprotein content of FⅪ-L424CfsX8 mutant decreased significantly in cell culture and lysate compared with the wild type(P<0.001).Conclusion:P.L424CfsX8 heterozygous deletion mutation is associated with decreased FⅪlevels in the proband,which may lead to impaired FⅪprotein secretion.

关 键 词：凝血因子XI缺陷症 基因突变 体外表达 

分 类 号：R446.1[医药卫生—诊断学]