FHL1-related reducing-body myopathy and other genetic forms of myofibrillar myopathies: composition of pathological protein aggregates revealed by laser capture microdissection and subsequent proteomic analysis

四个半LIM结构域基因(FHL1)相关的肌病(FHL1opathies)至少包括两种不同的肌病，即减少性躯体肌病(RBM)和X染色体肌病伴姿势肌萎缩(XMPMA)。这两种肌病都是进行性肌病，骨骼肌组织中有病理性胞浆内包涵体(胞浆和还原小体)。严重的RBM通常会导致儿童早期死亡。申请人独立参与了导致这两种疾病的FHL1突变的发现1，18。此外，利用激光显微解剖胞浆内包涵体和聚集体，随后在RBM肌肉组织标本中进行纳米流LC-MS/MS和蛋白质组分析，为发现罕见的骨骼肌结构异常的肌肉疾病的潜在基因突变开辟了一条新的途径。除了特殊的包涵体外，FHL1病的组织病理学与肌原纤维肌病的光谱重叠，有证据表明颗粒膜物质和Z线改变。我们项目的目标是：1.定义FHL1病的临床、组织病理学和突变谱及其对疾病机制的影响；2.定义遗传分类的肌纤维性肌病和参与该联盟的转基因动物的病理性蛋白聚集体的蛋白质组谱；3.通过激光捕获显微切割(LCM)病理性蛋白聚集体，然后进行蛋白质组和后续的遗传分析，以确定新的致病基因。

The spectrum of four and a half LIM domain gene- (FHL1) associated myopathies (FHL1opathies) encompasses at least two distinct myopathies, the reducing body myopathy (RBM) and the X-chromosomal myopathy with postural muscle atrophy (XMPMA). Both are progressive myopathies with pathognomonic intracytoplasmic inclusions (cytoplasmic and reducing bodies) in the skeletal muscle tissue. The severe form of RBM often leads to death in early childhood. The applicants were independently involved in the discovery of FHL1 mutations to be causative for both diseases1,18. Furthermore, using laser microdissection of the intracytoplasmic inclusions and aggregates followed by nanoflow LC-MS/MS coupled with proteomic analysis in RBM muscle tissue specimens, a new approach was set for the discovery of underlying gene mutations in rare myopathies with structural abnormalities of skeletal muscle. In addition to specific inclusions, the histopathology of FHL1opathies overlaps with the spectrum of myofibrillar myopathies, with evidence of granulofilamentous material and Z-line alterations. Therefore these myopathies have to be included in the group of myofibrillar myopathies.The aims of our project are: 1. to define the clinical, histopathological, and mutational spectrum of FHL1opathies and their consequences for the disease mechanisms; 2. to define proteomic spectra of pathological protein aggregates from genetically classified myofibrillar myopathies and transgenic animals involved in this consortium; 3. to define new causative genes in unclassified forms of MFM by laser capture microdissection (LCM) pathological protein aggregates followed by proteomic and subsequent genetic analysis.