脂肪干细胞移植对Duchenne型肌营养不良症鼠神经肌肉再生单位的影响

背景：目前,Duchenne型肌营养不良症尚无有效治疗方法,之前的研究表明基因治疗和干细胞移植治疗是可能的“治愈”方法。实验拟将两者结合起来,在动物模型上观察其疗效,并验证之前提出的神经肌肉再生单位的假说。 目的：探讨脂肪干细胞移植治疗Duchenne型肌营养不良症的有效性和可行性,观察细胞移植对肌纤维、新生血管及神经末梢的影响。 方法：体外分离培养mdx鼠脂肪干细胞,经杆状病毒基因载体进行基因修饰,用于移植治疗Duchenne型肌营养不良症模型鼠。移植后检测实验动物的血清肌酸激酶水平、肌肉病理改变及肌肉内dystrophin表达;免疫荧光检测细胞移植后血管、肌肉和神经再生情况。 结果与结论：细胞移植后,能够重建模型鼠的dystrophin表达,一定程度上减轻并逆转肌肉的病理损害,进而降低血清激酸激酶水平;此外,细胞移植后能够形成干细胞来源的肌纤维、血管内皮细胞和神经末梢。这些证据表明,脂肪干细胞移植是有希望治疗Duchenne型肌营养不良症的方法之一。     

Duchenne型肌营养不良症的细胞治疗

Duchenne型肌营养不良症（Duchenne muscular dystrophy，DMD）表现为进行性肌肉萎缩，是一种致死性、遗传性神经肌肉疾病。尽管对肌肉萎缩的分子机理的研究取得了很大进展，但是仍然不能治愈，细胞治疗是很有前景的一种治疗方法。成肌细胞移植面临的主要限制是注射后细胞分布差，免疫排斥和细胞存活率低；骨髓干细胞移植需要解决横向分化的低效率问题；而肌源性干细胞看来能更有效地再生表达dystrophin的肌纤维。     

Duchenne型肌营养不良症肌细胞膜异常的研究

本文应用凝集素免疫电镜和冷冻断裂电镜技术，通过对6例DMD患者组和4例健康对照组骨骼肌细胞膜的观察，发现RCA-I和WGA凝集素受体主要分布在肌质膜上，DMD患者有40％左右的肌质膜存在局限性的受体分布缺损区，并且DMD肌质膜的PF面和EF面上的膜蛋白颗粒还明显减少，从分子病理学水平证实了DMD存在肌细胞膜的异常。     

Duchenne型肌营养不良症的产前基因诊断研究

应用Ｄｕｃｈｅｎｎｅ型肌营养不良症（Ｄｕｃｈｅｎｎｅ　ｍｕｓｃｕｌａｒ　ｄｙｓｔｒｏｐｙ，ＤＭＤ）基因的ｃＤＮＡｓ作为探针，以限制性片段长度多态（ＲＦＬＰ）分析为策略，采用Ｓｏｕｔｈｅｒｎ分子杂交方法，成功地对１例可疑ＤＭＤ的男性胎儿及１例ＤＭＤ患儿进行基因诊断。结果显示该胎儿ＤＭＤ基因正常，而患儿存在ＤＭＤ基因缺失（缺失２．１５ｋｂ）。在基因分析前，应用聚合酶链式反应（ｐｏｌｙｍｅｒａｓｅ　ｃｈａｉｎ　ｒｅａｃｔｉｏｎ，ＰＣＲ）技术鉴定胎儿性别为男性。胎儿出生后检查结果与与产前基因诊断相吻合。为了获得高灵敏度探针，本文采用地高辛配基标记ＤＮＡ探针的方法，通过酶联免疫法，使分子杂交的ＤＮＡ检测带出现颜色反应。实验结果表明，此方法适用于基因组单拷贝ＤＮＡ顺序的检测，具有快速、安全等优越性，可以替代同位素进行推广、应用。     

外显子跳跃治疗Duchenne型肌营养不良症的研究进展

Duchenne型肌营养不良症是一种致死性肌肉疾病,抗肌萎缩蛋白基因缺陷是导致本病的原因,目前本病尚无特效的疗法.反义寡核苷酸(antisense oligonucleotides,AOs)诱导的外显子跳跃作为一种新的治疗手段具有良好的应用前景.本文主要从外显子跳跃治疗的原理、基础研究及临床研究进行综述.     

Duchenne型肌营养不良症基因诊断进展

Duchenne dystrophies(DMD)是人类常见的X染色体连锁隐性遗传病,至今尚无有效的治疗方法。DMD由人类Dystrophin基因突变引起,其突变机制复杂,探索简便、准确的基因突变检测技术是DMD研究的热点之一。基因诊断已经被广泛应用到DMD的临床研究中,并且在确诊患者、筛查携带者、产前诊断以及指导基因治疗等方面取得了较大进展。     

Duchenne型肌营养不良症的基因诊断和产前诊断的研究进展

Ｄｕｃｈｅｎｎｅ型肌营养不良症的基因诊断和产前诊断的研究进展天津儿童医院儿研所（３０００７４）高文英Ｄｕｃｈｅｎｎｅ型肌营养不良症（Ｄｕｃｈｅｎｎｅｍｕｓｅｃｕｌａｒｄｙｓｔｒｏｐｈｙ）简称（ＤＭＤ），是神经系统遗传性疾病中的一种较常见的Ｘ－连锁隐性...     

Duchenne型肌营养不良产前诊断的研究进展

众所周知，Duchenne型肌营养不良(Duchenne muscular dystrophy，DMD)是男性最常见的性连锁隐性遗传的致死性疾病。发病率为男性活婴的1／3500，女性致病基因携带者频率亦较高。多数受累儿童运动肌发育延迟，约有一半患儿在18个月前不会走路．肌肉无力和萎缩通常是对称的，9—12岁瘫痪。在该病的末期，全身肌肉无力并萎缩，患者出现恶病质。胸廓强直变形，进行性呼吸衰竭，导致慢性呼吸功能不全。     

骨髓移植治疗Duchenne型肌营养不良模型鼠的实验研究

目的：观察骨髓移植治疗Duchenne型肌营养不良（DMD）模型鼠（mdx鼠）后,骨骼肌中抗肌萎缩蛋白的表达，以及病理、生理和运动功能的变化情况，从而正确评价骨髓移植治疗DMD的疗效。 方法： 以正常C57鼠作为供者，以致死剂量放疗后的mdx鼠作为受者进行骨髓移植，在移植后4个月和6个月分别用荧光免疫组化法观察抗肌萎缩蛋白表达情况，用HE染色观察并计算骨骼肌细胞核中心移位纤维比例（CNF），同时进行mdx鼠腓肠肌电生理检查和运动功能检测。 结果： 骨髓移植后的mdx鼠骨骼肌细胞膜上有部分抗肌萎缩蛋白表达，CNF比例和肌肉湿重下降，mdx鼠的被动运动功能增强。 结论： 骨髓移植后，骨髓干细胞在mdx鼠体内的骨骼肌和骨髓中定居，并分化成可以表达抗肌萎缩蛋白的骨骼肌细胞，使mdx鼠病理、生理得到部分改善，最终导致了肌肉的运动功能的增强。说明骨髓移植治疗DMD是有一定价值的，为临床应用提供实验基础。     

神经肌接头乙酰胆碱受体簇集的分子机制

从运动神经元到肌细胞的信息传递主要通过神经肌接头来完成。神经肌接头重要的结构特征是高度特化的突触后膜。突触后膜异常簇集着大量的乙酰胆碱受体。乙酰胆碱受体簇集与3种分子密切相关,即集聚蛋白(Agrin)、肌特有受体酪氨酸激酶(MuSK)及突触后膜受体缔合蛋白(Rapsyn);Agrin诱导AChR在终板膜的簇集,MuSK为Agrin信号转导受体复合体的重要组分之一,Rapsyn则参与其效应机制。     

Immunoproteasome in animal models of Duchenne muscular dystrophy

Increased proteasome activity has been implicated in the atrophy and deterioration associated with dystrophic muscles of Duchenne muscular dystrophy (DMD). While proteasome inhibitors show promise in the attenuation of muscle degeneration, proteasome inhibition-induced toxicity was a major drawback of this therapeutic strategy. Inhibitors that selectively target the proteasome subtype that is responsible for the loss in muscle mass and quality would reduce side effects and be less toxic. This study examined proteasome activity and subtype populations, along with muscle function, morphology and damage in wild-type (WT) mice and two murine models of DMD, dystrophin-deficient (MDX) and dystrophin- and utrophin-double-knockout (DKO) mice. We found that immunoproteasome content was increased in dystrophic muscles while the total proteasome content was unchanged among the three genotypes of mice. Proteasome proteolytic activity was elevated in dystrophic muscles, especially in DKO mice. These mice also exhibited more severe muscle atrophy than either WT or MDX mice. Muscle damage and regeneration, characterized by the activity of muscle creatine kinase in the blood and the percentage of central nuclei were equally increased in dystrophic mice. Accordingly, the overall muscle function was similarly reduced in both dystrophic mice compared with WT. These data demonstrated that there was transformation of standard proteasomes to immunoproteasomes in dystrophic muscles. In addition, DKO that showed greatest increase in proteasome activities also demonstrated more severe atrophy compared with MDX and WT. These results suggest a putative role for the immunoproteasome in muscle deterioration associated with DMD and provide a potential target for therapeutic intervention.     

Pathogenic and nonpathogenic deletions in two families with Duchenne muscular dystrophy

Two deletions detected within the Duchenne/Becker muscular dystrophy (D/BMD) gene of normal male members of two DMD families were both independent, nonpathogenic deletions located in a large intron in the XJ region (DXS206) toward the 5' end of the gene [Burghes et al., 1987]. Investigation of the surrounding exons revealed no exon deletions or duplications. The simplest interpretation of these observations is that the deletions are entirely intronic and do not cause perturbation of the gene product, resulting in a normal phenotype. The disease phenotypes in the affected males in these two families are caused by exon deletions remote from this intron. Some caution is therefore indicated in using genomic deletions for clinical prediction.     

Components of energy expenditure in themdx mouse model of Duchenne muscular dystrophy

Previous observations showing that basal heat production rates and glucose metabolism were reduced inmdx mouse skeletal muscles incubated in vitro led us to study the components of total energy expenditure by open-circuit indirect calorimetry in the intact, free-movingmdx mouse. Our purpose was to verify if themdx mouse exhibited whole-body alterations in energy metabolism. The results revealed that total and basal energy expenditure, as well as spontaneous activity, energetic cost of activity, and, therefore, energy expended in relation to activity were not significantly different in C57B1 / 10 (control) and in dystrophic (mdx) mice. In contrast, the thermic effect of food was 32% larger inmdx than in control mice and was accompanied by significant differences in postprandial glucose and lipid oxidation. The present in vivo study could not show a direct demonstration that impaired glucose metabolism by skeletal muscles participated in this phenomenon. However, since postprandial glucose metabolism by skeletal muscles contributes a significant part of the thermic effect of food, the present data are in line with previous studies in vitro that show thatmdx mouse skeletal muscles probably suffer an impaired control of their energy metabolism.