MICA: Strategy for heart repair in Duchenne Muscular Dystrophy (DMD) using genetically engineered autologous Mesoangioblasts

MICA：利用基因工程自体中成血管细胞修复杜氏肌营养不良症 (DMD) 的心脏的策略

• 批准号: MR/X00466X/1
• 负责人: Francesco Galli
• 金额: $ 51.79万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FX00466X%2F1
• 关键词: MICA; Strategy; heart; repair; Duchenne

The NHS official website indicates that around 70,000 people have Muscular Dystrophy (MD) or a related condition in the UK. Duchenne Muscular Dystrophy (DMD) is the most common and one of the most severe forms of MD. DMD is an inherited disease due to lack of expression of the dystrophin protein, causing a progressive waste of skeletal muscle which lead to progressive loss of ambulation, muscle weakness and muscle wasting in children. In the most severe cases, also heart muscle cells are affected, and this result in heart failure, the most common cause of premature death in DMD patients. All MDs still lack an effective therapy, even though administration of steroids (although with severe adverse effects), corrective surgery, assisted ventilation and drugs to support cardiac function have improved both the duration and the quality of life for patients.Many approaches based on either stem cells or gene therapy have entered clinical experimentation with the aim of repairing DMD heart, but none has reached significant clinical efficacy. The limited success of these therapies is due both to the difficulties of delivering the treatment to the heart and to the activation of the immune system of the patients towards donor cells or viral vectors. To overcome these limitations, I have developed a cell mediated exon skipping strategy, for skeletal muscle, currently being tested in a clinical trial in Manchester (EudrAct n.2019-001825-28), based upon transplantation of autologous Mesoangioblasts (Mabs), which are vessel-associated myogenic progenitors. Mabs are genetically corrected using a lentivector expressing a small nuclear RNA (snRNA) designed to induce exon-skipping on dystrophin exon 51 and to generate a short but functional version of dystrophin. The novelty of this approach is based on the ability of snRNA to diffuse along the regenerating muscle fibre and then correcting the resident dystrophic neighbouring nuclei inducing exon skipping. However, Mabs can be used only for the treatment of skeletal muscle as they cannot naturally differentiate into cardiac muscle: for this reason, the heart of the MD patients would remain untreated. In this project I will address this problem. It is well known that fibroblasts can be converted to cardiac muscle cells but, in comparison with Mabs, they cannot be delivered systematically, due to their inability to cross the vessel walls. This makes cardiac-converted fibroblasts good candidates to treat only localised lesions like myocardial infarct but not to treat progressive and widespread cardiomyopathies. My preliminary data show that Mabs can be converted to cardiomyocytes by transient over-expression of specific cardiac related genes in around 10-15 days. I therefore hypothesize that this time window will allow to deliver these Mabs-converted cardiomyocytes by cardiac catheterization in the whole heart. This project aims to evaluate the structural and functional amelioration of the heart in a mouse model of DMD after transplantation of Mabs-converted cardiomyocytes. Moreover, I will quantify the extent of the fusion of genetically corrected Mabs-converted cardiomyocytes with resident cardiomyocytes and subsequently the rate of correction, by exon-skipping, in the neighbouring nuclei quantifying the amount of dystrophin produced.The core element of this strategy is already in clinical experimentation for DMD skeletal muscle but not for the heart. This project will test the applicability of the cell mediated exon-skipping strategy to the heart. The succesful outcome of this project, demonstrating the efficacy of this strategy, will lead the way for a future clinical testing of this strategy in the heart of DMD patients and in heart diseases in general.

NHS官方网站指出，大约有70,000人患有肌肉营养不良（MD）或英国相关状况。 Duchenne肌肉营养不良（DMD）是最常见的MD形式，也是最严重的形式之一。 DMD由于缺乏肌营养不良蛋白的表达而导致遗传性疾病，导致骨骼肌的逐渐浪费导致儿童的行动逐渐丧失，肌肉无力和肌肉浪费。在最严重的情况下，心肌细胞也受到影响，这导致心力衰竭，这是DMD患者过早死亡的最常见原因。即使服用类固醇（尽管严重不良），矫正手术，辅助通风和支持心脏功能的药物也已改善了患者的持续时间和生活质量，但基于干细胞或基因治疗的经常方法已经进入了临床实验，但没有一个临床实验，但所有MD的目标都可以改善临床实验，但没有任何临床实验，但没有一个临床实现的目的，但所有MD的目标都在临床实验中，但没有一个临床实验，但没有任何MDS仍缺乏有效的疗法，矫正手术，辅助通风和支持心脏功能的药物已经改善了患者的持续时间和生活质量。基于干细胞或基因疗法的许多方法已经进入了临床实验，但没有任何维修DMD心脏的临床实验，但具有重要的临床效果。这些疗法的成功有限是由于将治疗方法传递给心脏的困难以及患者免疫系统向供体细胞或病毒载体的激活。为了克服这些局限性，我已经开发了一种细胞介导的外显子跳过策略，用于骨骼肌，目前在曼彻斯特的临床试验中对基于自体中含中含中含中的肌血管分泌（MABS）的临床试验（Eudract N.2019-001825-28）进行了测试，这些试验是血管中的自体血管分泌（MABS），这些（MABS）是血管 - 与血管相关的肌肉相同的疾病。使用表达小核RNA（SNRNA）的烯烃校正mAb，旨在诱导肌营养不良蛋白外显子51上的外显子伸缩并产生短而功能的肌营养不良蛋白。这种方法的新颖性是基于snRNA沿重生肌肉纤维扩散的能力，然后纠正驻留性障碍性邻近的核能诱导外显子跳过。但是，mAB只能用于治疗骨骼肌，因为它们无法自然地分化为心肌：因此，MD患者的心脏将不受治疗。在这个项目中，我将解决此问题。众所周知，成纤维细胞可以转化为心肌细胞，但与mAb相比，由于它们无法越过血管壁，因此无法系统地输送它们。这使得心脏转化的成纤维细胞可以仅治疗诸如心肌梗死的局部病变，但不能治疗进步和广泛的心肌病。我的初步数据表明，可以通过大约10-15天内特定心脏相关基因的瞬时过表达将mAB转换为心肌细胞。因此，我假设这个时间窗口将允许通过心脏插入术在整个心脏中通过心脏导管来传递这些转换的心肌细胞。该项目旨在评估移植受mABS转换的心肌细胞移植后DMD小鼠模型中心脏的结构和功能改善。此外，我将量化遗传校正的mAb转换的心肌细胞与驻留心肌细胞的融合程度，随后通过外显子甲基化在附近的核中量化了这种策略的核心元素。该项目将测试细胞介导的外显子刀具策略对心脏的适用性。该项目的成功结果证明了这种策略的功效，将为DMD患者的心脏中心和心脏病的心脏疾病的未来临床测试带来途径。