Welander distal myopathy is caused by a mutation in the RNA-binding protein TIA1
Welander distal myopathy is caused by a mutation in the RNA-binding protein TIA1
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DOI：
10.1002/ana.23831
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发表时间：
2013-04-01
影响因子：
11.2
通讯作者：
Udd, Bjarne
中科院分区：
文献类型：
--
作者：
Hackman, Peter;Sarparanta, Jaakko;Udd, Bjarne
目的 进行一项研究来确定 Welander 远端肌病 (WDM)（一种经典的常染色体显性远端肌病）的分子病因。方法通过微卫星和单核苷酸多态性单倍型分析证实和定义遗传连锁。通过靶向高通量测序和桑格测序对整个连锁基因组区域进行测序，并在 cDNA 水平上对编码转录本进行测序。通过蛋白质印迹和免疫荧光显微镜研究 WDM 肌肉活检。通过逆转录聚合酶链反应分析肌肉和成肌细胞培养物中 TIA1 及其靶基因的剪接。通过对 HeLa 细胞进行细胞生物学研究来表征突变体 TIA1，包括通过高内涵分析对应激颗粒进行定量以及光漂白 (FRAP) 实验后的荧光恢复。结果 2p13 处的连锁单倍型在 RNA 结合蛋白 TIA1 中缩小为 A (p.E384K)，TIA1 是应激颗粒的关键成分。 WDM 活检的免疫荧光显微镜显示萎缩和空泡纤维中 TIA1 局部增加。在 HeLa 细胞中，与野生型相比，突变型 TIA1 构建体导致应激颗粒丰度略有增加，并且在 FRAP 中显示出较慢的平均荧光恢复。解释 WDM 是由 TIA1 突变通过主要病理机制引起的，可能涉及应激颗粒动力学改变。安·尼罗尔 2013；73:500-509
Objective A study was undertaken to identify the molecular cause of Welander distal myopathy (WDM), a classic autosomal dominant distal myopathy. Methods The genetic linkage was confirmed and defined by microsatellite and single nucleotide polymorphism haplotyping. The whole linked genomic region was sequenced with targeted high-throughput and Sanger sequencing, and coding transcripts were sequenced on the cDNA level. WDM muscle biopsies were studied by Western blotting and immunofluorescence microscopy. Splicing of TIA1 and its target genes in muscle and myoblast cultures was analyzed by reverse transcriptase polymerase chain reaction. Mutant TIA1 was characterized by cell biological studies on HeLa cells, including quantification of stress granules by high content analysis and fluorescence recovery after photobleaching (FRAP) experiments. Results The linked haplotype at 2p13 was narrowed down to A (p.E384K) in the RNA-binding protein TIA1, a key component of stress granules. Immunofluorescence microscopy of WDM biopsies showed a focal increase of TIA1 in atrophic and vacuolated fibers. In HeLa cells, mutant TIA1 constructs caused a mild increase in stress granule abundance compared to wild type, and showed slower average fluorescence recovery in FRAP. Interpretation WDM is caused by mutated TIA1 through a dominant pathomechanism probably involving altered stress granule dynamics. Ann Neurol 2013;73:500-509