抗肌萎缩蛋白病一家系的临床、分子病理及遗传学特点

目的 分析并确定1个抗肌萎缩蛋白病(dystrophinopathy)家系的临床、分子病理及遗传学特征.方法 收集先证者及其家系成员的临床资料,对先证者行肌肉活体组织检查,采用抗层黏连蛋白α2(1aminin α2,又称merosin)、抗emerin蛋白、抗肌萎缩蛋白(dystrophin)中央棒状区(Dys1)、C′末端(Dys2)、N′末端(Dys3)单克隆抗体行免疫组织化学染色;提取外周血基因组DNA,采用多重连接探针扩增(MLPA)进行抗肌萎缩蛋白Duchenne型肌营养不良(DMD)基因检测.结果 该家系中包括先证者在内共有3例患者临床诊断为肌营养不良,均无腓肠肌肥大,但病情重、进展较快,同时先证者肌肉活体组织检查行免疫组织化学染色提示dystrephin蛋白部分缺失,merosin、emerin染色呈阳性表达.MLPA检测显示先证者DMD基因第45～54外显子缺失,其母在第45～54外显子区域为杂合性缺失.结论 该家系中的先证者DMD基因为第45～54外显子缺失,突变基因来自母亲,其母为表型正常的携带者.dystrophin蛋白表达异常是造成抗肌萎缩蛋白病表型的病理基础,其临床后果不仅取决于dystrophin蛋白表达缺失的程度,还取决于DMD基因缺失区域的功能.     

肌营养不良蛋白表达对肌营养不良症的诊断意义

目的：探讨肌营养不良蛋白在肌营养不良症患者肌组织中表达的意义。方法：运用免疫组化法对12例Duchenne型肌营养不良症（DMD）患者及5例Becker型肌营养不良症（BMD）患者的肌组织中肌营养不良蛋白的表达进行分析。并用6例非神经肌肉疾病患者的肌组织作为对照。结果：对照组6例肌组织标本中均可见肌营养不良蛋白表达,其阳性染色勾画出肌细胞的边界,胸及胞浆呈阴性。在DMD中有10例（83．33％）肌细胞膜肌营养不良蛋白不表达。BMD中3例（60）可见沿肌细胞膜分的不连续斑片状弱阳性染色。结论：肌营养不良蛋白的缺失或异常表达,是DMD／BMD型较为特异的改变。运用免疫组化法检测患者肌组织中肌营养不良蛋白的表达,可为DMD／BMD型的病理诊断提供特异指标。     

自噬在Duchenne型肌营养不良中的研究

目的检测Duchenne型肌营养不良症(DMD)患者骨骼肌中LC3和p62的表达情况,分析自噬在DMD骨骼肌细胞坏死中的作用。方法收集2008年1月~2015年5月在我院就诊的病理确诊为DMD的患者(DMD组,81例),另以怀疑为肌病,但肌肉病理未见明显病变者为对照组(6例)。所有入选者均行心肌酶学、肌电图、骨骼肌活检常规组织学和酶学染色、抗dystrophin-N,-C,-R和抗dysferlin免疫组织化学染色。检测其中6例DMD患者及对照组骨骼肌中LC3和p62的表达。结果 81例DMD患者均为男性,起病年龄(4.60±2.35)岁,首发症状多以双下肢起病为主。血清肌酸激酶值的高峰出现在患者年龄的6~8岁,随着肌细胞明显坏死,肌酸激酶水平下降,但仍高于正常。在DMD患者骨骼肌中,组织病理均示典型肌营养不良改变。半定量Western blot提示DMD患者骨骼肌中LC3-II的表达降低,而p62表达显著升高。结论自噬功能障碍可能参与了DMD骨骼肌细胞坏死的病理生理过程。     

免疫组织化学dystrophin染色诊断Duchenne型肌营养不良症的研究

目的 探讨Duchenne型肌营养不良症(DMD)肌萎缩蛋白(dystrophin)表达规律和临床意义.方法 收集我院7例DMD患者作为试验组,7例非DMD患者为对照组.使用抗dystrophin杆状结构域单抗、免疫组织化学染色,观察肌膜dystrophin表达.结果 7例DMD患者肌细胞膜dystrophin阴性,7例非DMD患者dystrophin染色阳性.结论 证实DMD患者肌细胞膜dystrophin表达阴性,揭示dystrophin缺失是其发病机制,可以作为确诊DMD手段,对临床诊断DMD有实际意义.     

神经肌肉病患者肌肉中utrophin和dystrophin蛋白表达的相关性

目的探讨utrophin和dystrophin蛋白在神经肌肉病患者肌肉中的表达及其相关性。方法采用免疫荧光方法观察26例共8种神经肌肉疾病患者及2名无神经肌肉疾病者的正常肌肉活检标本冰冻切片utrophin和dystrophin蛋白的表达。结果dystrophin蛋白在Duehenne型肌营养不良（DMD）患者显示为大部分肌纤维荧光圈带缺失、荧光圈带亮度减弱或荧光圈带呈不连续状；在非DMD的肌营养不良、脂肪累积性肌病、强直性肌营养不良、神经源性肌萎缩、多发性肌炎、线粒体脑肌病、肌源性肌萎缩患者肌肉膜上呈现一圈完整的强荧光圈带；在对照组肌肉膜上呈现一圈完整的强荧光圈带。utrophin蛋白在dystrophin蛋白重度减少的DMD患者少部分肌纤维肌膜上呈现不连续的荧光圈带，但强度较弱；在dystrophin蛋白中度减少的DMD患者、非DMD的肌营养不良及其他6种神经肌肉病患者肌肉膜上不显示荧光；在对照组肌肉膜上不显示荧光。结论DMD患者肌肉的dystrophin蛋白表达重度减少的同时，出现utrophin蛋白的表达；而包括DMD患者dystrophin蛋白中度减少、非DMD的肌营养不良在内的其他神经肌肉病患者肌肉的dystrophin蛋白正常表达时，其utrophin未出现表达。     

Turner综合征合并抗肌萎缩蛋白病的临床表现及病理学改变

目的 探讨Turner综合征合并抗肌萎缩蛋白病（dystrophinopathy）的临床表现、病理学特点。方法 开放式骨骼肌活检,组化染色、免疫组化染色,病理分析。结果 HE染色显示中度肌萎缩,萎缩肌纤维多呈圆形,偶见坏死肌纤维,散在不透明纤维,肌间结缔组织轻度增生。抗Dystrophin-N,-C,-R单克隆抗体染色肌纤维膜淡染。结论 此文报道的患者可能为携带dystrophin缺陷基因的Turner综合征患者,因其缺少1条正常X染色体的补偿作用而出现抗肌萎缩蛋白病表现。     

针吸型肌肉活检联合免疫荧光在假肥大型肌营养不良诊断中的应用

目的 探讨应用针吸型肌肉活检结合免疫荧光染色诊断假肥大型肌营养不良症的应用价值及意义。方法 应用针吸型活检术取533例假肥大型肌营养不良症患者(415例DMD, 118例BMD)的肌组织,采用HE染色观察肌细胞形态,免疫荧光染色技术检测抗肌营养不良蛋白, 以2 例正常人的肌细胞作为对照。结果 正常人肌细胞膜上抗肌萎缩蛋白染色阳性,可见沿肌细胞膜分布完整的荧光条带; DMD 患者肌膜染色阴性,肌细胞膜完全不显色; BM D患者染色弱阳性, 可见沿肌细胞膜分布的间断斑片状荧光带。结论 应用针吸型活检术联合免疫荧光染色可以有效的检测抗肌营养不良蛋白的表达, 有助于DMD 和BMD 的确诊及鉴别诊断。     

Ezrin蛋白在肌病患者骨骼肌中的表达及意义

目的 研究Ezrin蛋白在肌病患者骨骼肌中的表达及意义.方法 取肌纤维再生活跃的假肥大型肌营养不良(DMD,9例)和多发性肌炎(PM,5例)患者的骨骼肌标本,冰冻连续切片,进行HE染色及抗-Ezrin、抗-神经细胞黏附分子(NCAM)单克隆抗体免疫组化染色,观察被检肌的病理改变和Ezrin蛋白的表达.结果 DMD、PM患者被检肌HE染色所见再生肌纤维直径较小、核位于中央、胞浆嗜碱性;NCAM染色再生肌纤维深染;再生肌纤维Ezrin呈阳性表达,伴随肌纤维成熟Ezrin表达逐渐减弱,成熟肌纤维无Ezrin表达;成肌细胞Ezrin呈阳性表达.结论 Ezrin蛋白与DMD、PM肌病患者骨骼肌纤维再生可能存在密切关系.     

血清MMP-9与DMD骨骼肌纤维化的相关性分析

目的探讨血清MMP-9与DMD骨骼肌纤维化的关系。方法收集DMD、BMD患者腓肠肌组织和非抗凝血以及正常儿童非抗凝血,对腓肠肌肌组织行HE染色观察骨骼肌基本病理改变,Masson染色观察骨骼肌纤维化程度,进行免疫组织化学链霉素抗生物素蛋白过氧化物酶连结(SP)法观察MMP-9在肌肉组织中的分布情况。非抗凝血行ELISA法进行血清MMP-9、TIMP-1、TGF-β1浓度测定,并将DMD组按病情分为5岁、5~9岁组、9岁组。结果 DMD组纤维化程度比BMD组高(P0.05);在DMD患者中,5岁组、5~9岁组、9岁组间纤维化程度差异均有统计学意义(P0.05),且纤维化程度与患儿年龄成正相关(r=0.694,P0.05);MMP-9存在于DMD骨骼肌中,且在巨噬细胞浸润的部位表达增强;在DMD患者中,5岁组、9岁组与5岁组相比,血清MMP-9浓度降低(P0.05),5~9岁组与9岁组相比,血清MMP-9浓度差异无统计学意义(P0.05);9岁前的DMD患者,血清MMP-9浓度与年龄成正相关(r=0.6118,P0.05)。结论血清MMP-9浓度在一定程度上反映了DMD病情变化,可作为评估DMD病情变化及DMD早期治疗效果的指标。     

近端型脊肌萎缩症骨骼肌病理及其形态定量分析的研究

目的　探讨骨骼肌病理活检和病变肌细胞形态定量分析对婴儿及儿童期发病脊肌萎缩症的临床诊断意义。方法　 1 5岁以下脊肌萎缩症 31例 ,肌肉活检标本作常规HE染色和肌肉酶组化染色 ,应用图像分析系统对肌肉活检切片进行定量分析 ,计算每例正常细胞平均面积与病变细胞平均面积的比值。结果　肌肉病理和免疫组化改变为神经性肌萎缩 ,肌细胞变圆或呈角形 ,出现病变细胞变圆的都为 1岁以前的患者 ,而 1岁以后发病的患者大多出现呈角形细胞 ;半数有明显的同型肌群化现象。两种细胞的面积比值与发病年龄呈负相关 (r=-0 2 7,P <0 0 5) ,而与病程呈正相关 (r=0 37,P <0 0 1 ) ,与年龄没有相关关系。结论　应用图像分析系统对肌肉切片进行定量分析 ,以正常细胞与病变细胞面积比值可作为判断脊肌萎缩症病变程度的指标之一。     

DMD/BMD肌细胞抗肌营养不良蛋白免疫荧光组化研究

目的:研究Duchenne/Becker型肌营养不良症(DMD/BMD)患者肌细胞中抗肌营养不良蛋白(dystrophin)的表达及其诊断意义。方法:采用免疫荧光抗体染色技术对5例DMD,2例BMD肌细胞中抗肌营养不良蛋白进行检测,以2例正常人的肌细胞作为以照。结果:对照组肌细胞膜上染色阳性,胞核及胞浆呈阴性;DMD患者肌膜完全无显色;BMD患者染色弱阳性,可见沿肌细胞膜分布的间断斑片状荧光带。结论:抗肌营养不良蛋白缺乏或表达异常是DMD/BMD基本病理基础。应用免疫荧光抗体染色法检测抗肌营养不良蛋白,有助于DMD和BMD的确诊及鉴别诊断     

Duchenne型肌营养不良症肌肉超微病理研究

目的:观察Duchenne型肌营养不良症(DMD)患者病变肌肉超微病理特征,从亚细胞水平上探讨其发病机制。方法:对临床确诊的7例DMD患者,通过肌肉活检进行超薄切片和冷冻复型透射电镜观察。结果:超薄切片电镜观察显示:(1)肌原纤维"Z"线模糊不清,肌原纤维过收缩、肌丝排列紊乱等变性、坏死。(2)肌纤维内线粒体空泡样变;糖原累积;肌浆网有程度不等的病变。(3)间质毛细血管内皮细胞肿胀、闭塞,血流瘀滞。冷冻复型电镜观察显示:粗细肌丝排列紊乱,膜蛋白颗粒大小不等的变化。结论:DMD时,肌细胞膜结构缺陷除可导致肌纤维变性、坏死外,还可致线粒体、糖原、肌浆网及肌原纤维板层体膜内颗粒等一系列亚细胞水平的变化;另外,血液循环障碍可导致肌细胞继发变性、坏死,推测在本病的发病中也起着重要作用。     

Expression of myosin heavy chain isoforms in Duchenne muscular dystrophy patients and carriers

The expression of MHC isoforms in the skeletal muscles of nine patients with Duchenne muscular dystrophy (DMD) (from 2.5 to 15 yr of age) and three DMD carriers was studied using different specific anti-MHC MAbs. We also analyzed muscle fiber size and fiber reactivity with acridine orange and/or with a surface antigen marker. One-quarter of all fibers of DMD patients, or less with age, were of normal size and contained only adult slow MHC. Half of the muscle fibers contained adult and developmental MHCs. Only half of these fibers were representative of an active regenerative process. MHC co-expression also altered the proportion of normal fast or slow fibers. Adult fast MHCs were expressed as unique MHC only in small and very small fibers in the oldest DMD patients. In DMD carrier muscles, the greatest alterations in MHC expression were observed in patients with the most reduced dystrophin expression. However, MHC changes in dystrophin-positive fibers were similar to those observed in dystrophin-free fibers. In conclusion, disruptions or delays in the switching of all genes coding for adult fast and slow MHC and developmental MHC coincided with dystrophin deletion and with perturbations in its expression.     

Dystrophin-associated protein abnormalities in dystrophin-deficient muscle fibers from symptomatic and asymptomatic Duchenne/Becker muscular dystrophy carriers

The absence of dystrophin in muscle fibers is associated with a major reduction in dystrophin-associated proteins (DAPs) and disruption of the linkage between the subsarcolemmal cytoskeleton and the extracellular matrix. We investigated the expression of the DAPs β-dystroglycan, α-sarcoglycan, γ-sarcoglycan and syntrophin as well as utrophin in the muscles of 13 Duchenne muscular dystrophy (DMD) carriers (with variable percentages of dystrophin-deficient fibers and with a range of clinical symptoms), 2 Becker muscular dystrophy (BMD) carriers (expressing a highly truncated protein in some fibers), 2 girls with a DMD-like phenotype, and 11 BMD carriers with almost normal dystrophin expression (reduced or patchy distribution in a few fibers only and rare dystrophin-deficient fibers). DAPs were highly reduced in all fibers lacking dystrophin in the DMD carriers, but were almost normal in the dystrophin-deficient fibers of the 2 BMD carriers with highly truncated dystrophin. In the 11 BMD carriers with nearly normal dystrophin, the few fibers with reduced or patchy dystrophin immunostaining also showed reduced DAP expression in correlation with dystrophin expression. Immunoblot for β-dystroglycan and α-sarcoglycan confirmed the immunohistochemical findings. Utrophin expression was slightly increased in a proportion of fibers in the DMD and BMD carriers with dystrophin mosaicism. We found no correlation between utrophin expression and DAP expression. We conclude that absence or reduction of dystrophin in muscle fibers of DMD and BMD carriers causes a reduction of DAPs in the same fibers, as observed in DMD and BMD patients, while utrophin does not seem to play a role in DAP expression in adult muscle. Received: 11 January 1996 / Revised, accepted: 16 April 1996     

Transcriptional activation of the non-muscle, full-length dystrophin isoforms in Duchenne muscular dystrophy skeletal muscle.

Despite promoter tissue specificity, up-regulation of the brain and Purkinje cell type dystrophin isoforms was described in skeletal muscle of X-linked dilated cardiomyopathy (XLDCM) and BMD affected individuals. An extended population of 11 Duchenne muscular dystrophy (DMD) and 11 Becker muscular dystrophy (BMD) patients was investigated to determine whether ectopic muscle expression of the two full-length non-muscular isoforms is a common event in dystrophinopathies and if it has functional significance. Up-regulation of the two non-muscle-specific isoforms was detected in four DMD patients but in none of the BMD affected individuals or non-dystrophic controls. This is the first report of an expression of these two isoforms in DMD skeletal muscle. Ectopic expression is not confined to regenerating or revertant fibers and does not correlate with age at biopsy, clinical phenotype, cardiac involvement, deletion size or location.We consider that muscle ectopic expression of the brain and Purkinje cell-type isoforms has no favorable prognostic significance in DMD and BMD patients.     

Immunocytochemical analysis of dystrophin in congenital muscular dystrophy.

Using immunocytochemical methods, we examined the intensity and distribution of dystrophin and spectrin immunostaining of skeletal muscles from 51 congenital muscular dystrophy (CMD) patients including 36 Fukuyama congenital muscular dystrophy (FCMD) and 15 non-FCMD (other CMD). 17 age-matched spinal muscular atrophy (SMA) and 5 Duchenne muscular dystrophy (DMD) patient biopsies were studied as controls. All 15 non-FCMD and SMA patients showed normal localization of dystrophin at the surface membrane of each muscle fiber which was undetectable in DMD. In contrast, 34 of 36 FCMD patients exhibited an unusual immunostaining pattern with occasional (17-43%; mean = 28) negative or abnormally immunoreacted (partially deficient, fluffy or intense) fibers for dystrophin. Dystrophin was absent in 2 of 36 patients having a clinical diagnosis of FCMD, and intragenic deletion of the DMD gene was detected in one. Spectrin, a membrane cytoskeletal protein related to dystrophin, also showed an increased number of abnormally immunostained fibers in FCMD (25%), but not so high in age-matched DMD (9%) or SMA patient muscle (0%). Thus, our results suggested the presence of intrinsic factor(s) that produce abnormality of the plasma membrane of FCMD muscle.     

Molecular therapy of muscular dystrophy]

Muscular dystrophy is a nosology for a group of hereditary muscle disorders characterized by progressive wasting and weakness of skeletal muscle, where degeneration of muscle fibers is detected by pathological examination. Since the causative gene of Duchenne muscular dystrophy (DMD), the most severe and abundant form of muscular dystrophy, the DMD gene, and its product dystrophin was isolated by positional cloning by Dr. Kunkel and his colleagues, the studies on molecular pathologies of muscular dystrophy has been extensively developed. The current therapeutic approaches of muscular dystrophy, such as DMD involves pharmacological suppression of the inflammatory and immure responses, which usually provides only modest and temporary beneficial effects. Future approaches depend on cell and gene therapy technology and will require different strategies, none of which are currently ready to enter clinical practice. These approaches involve the efficient, non-antigenic gene transfer for in vivo gene therapy, pharmacological upregulation of the synthesis of utrophin, a related protein that compensates for the loss of dystrophin, and myogenic stem cell transplantation. These approaches could be integrated each other and called as molecular therapy.     

Dystrophin analysis in carriers of Duchenne and Becker muscular dystrophy

Associations between clinical phenotype (muscle weakness, dilated cardiomyopathy) and dystrophin abnormalities in muscle tissue among definite carriers of Duchenne (DMD) and Becker muscular dystrophy (BMD) were investigated. No associations between dystrophin abnormalities and clinical variables in DMD/BMD carriers were found. Because 26% of nonmanifesting carriers have dystrophin-negative fibers, this might be used in suspected DMD/BMD carriers in whom DNA analysis fails to give an answer about their carrier risk.     

A two-year-old clinically manifesting carrier of Duchenne muscular dystrophy

A two-year-old symptomatic carrier of Duchenne muscular dystrophy (DMD) confirmed by dystrophin immunohistochemical study was reported. She had mild proximal muscular weakness and elevated serum creatine kinase (CK) level. There were no family members of DMD. CT examination revealed low density areas in the muscles similar to that seen in the early stage of DMD. Biopsied specimen of muscle showed myopathic changes with necrotic and regenerating fibers. The immunohistochemical study using an antiserum against dystrophin showed the mosaic expression of the surface membrane, with positive and negative patches. Accordingly, she was strongly suggested to be a DMD carrier. This case shows that dystrophin immunohistochemistry is useful for diagnosis of a DMD carrier without affected family members.     

Dystrophin在不同类型肌营养不良症中的变化及诊断价值

目的研究dystrophin在不同类型肌营养不良症中的变化及分型诊断价值.方法用抗dystrophin抗体对107例肌营养不良症患者肌组织标本行免疫组织化学分析.结果Duchenne型肌营养不良(DMD)患者肌细胞膜上无显色,Becker型肌营养不良(BMD)患者肌细胞膜上显色浅淡、不连续或呈斑片状.肢带型肌营养不良(LGMD)患者肌细胞膜上染色正常.结论dystrophin免疫组化染色对于年龄较小临床不易区分的DMD/BMD患者,可区分开来,以早期预测功能影响程度.该方法也有助于区分临床表现相似的成年散发BMD和LGMD患者,对于正确地进行遗传咨询具有重要意义.