Project description:Large animal models for Duchenne muscular dystrophy (DMD) are indispensible for preclinical evaluation of novel diagnostic procedures and treatment strategies. To evaluate functional consequences of Duchenne muscular dystrophy (DMD) in skeletal muscle and myocardium, we used a new genetically engineered dystrophin KO pig model displaying hallmarks of human DMD. Heart and skeletal muscle tissue samples of DMD pigs and wild-type (WT) controls at three different ages were analyzed by label-free proteomics.
Project description:Muscle wasting in Duchenne Muscular Dystrophy is caused by myofiber fragility and poor regeneration that leads to chronic inflammation and muscle replacement by fibrofatty tissue. Our recent findings demonstrated that Resolvins, a class bioactive lipids derived from omega-3 fatty acids, have the capacity to dampen inflammation and stimulate muscle regeneration to alleviate disease progression. This therapeutic avenue has many advantages compared to glucocorticoids, the current gold-standard treatment for Duchenne Muscular Dystrophy. However, the use of bioactive lipids as therapeutic drugs also faces many technical challenges such as their short-half life. Here, we explored the potential of synthetic agonist of bioactive lipid receptor, namely the Gpr18 agonist PSB-KD107, as a therapeutic alternative for Duchenne Muscular Dystrophy. We showed that PSB-KD107 can stimulate the myogenic capacity of human iPSC-derived myoblasts in vitro. RNAseq analysis revealed an enrichment in biological processes related to lipid metabolism, small molecule biosynthesis, and steroid-related processes in PSB-KD107-treated cells, as well as pathways related to fatty acid signaling such as Peroxisome proliferator-activated receptors, AMP-activated protein kinase, and sphingolipid signaling pathways. In vivo, the treatment of dystrophic mdx mice with PSB-KD107 resulted in reduced inflammation, enhanced myogenesis, and improved muscle function compared to vehicle-treated mice. Overall, our findings identified a novel therapeutic target for the treatment of Duchenne Muscular Dystrophy.
Project description:Antibody suspension bead array based profiling of plasma samples collected from Duchenne and Becker muscular dystrophy patients and non-diseased controls and carriers at 4 different clinical sites
Project description:This study applies targeted Cas9-based gene insertion strategies for the correction of full-length dystrophin in a pre-clinical humanized mouse model of Duchenne muscular dystrophy. Following intramuscular or intravenous delivery, full-length dystrophin is restored in skeletal and cardiac muscle.
Project description:Canine muscular dystrophy (CXMDJ) is a dog model of the lethal X-linked muscle disorder Duchenne muscular dystrophy (DMD), which is caused by loss of dystrophin. Gene expression profile was analyzed in the diaphragm muscles of normal Beagle dogs and CXMDJ before and 1 hour after initial respiration.
Project description:Duchenne muscular dystrophy (DMD) is a genetic disease that results in the death of affected boys by early adulthood.The genetic defect responsible for DMD has been known for over 25 years, yet at present there is neither cure nor effective treatment for DMD. During early disease onset, the mdx mouse has been validated as an animal model for DMD and use of this model has led to valuable but incomplete insights into the disease process. For example, immune cells are thought to be responsible for a significant portion of muscle cell death in the mdx mouse; however, the role and time course of the immune response in the dystrophic process have not been well described. In this paper we constructed a simple mathematical model to investigate the role of the immune response in muscle degeneration and subsequent regeneration in the mdx mouse model of Duchenne muscular dystrophy. Our model suggests that the immune response contributes substantially to the muscle degeneration and regeneration processes. Furthermore, the analysis of the model predicts that the immune system response oscillates throughout the life of the mice, and the damaged fibers are never completely cleared.
Project description:Skeletal muscle wasting results from numerous pathological conditions impacting both the musculoskeletal and nervous systems. A unifying feature of these pathologies is the upregulation of members of the E3 ubiquitin ligase family, resulting in increased proteolytic degradation of target proteins. Despite the critical role E3 ubiquitin ligases in regulating muscle mass, the specific proteins they target for degradation and the mechanisms by which they regulate skeletal muscle homeostasis remain ill-defined. Here, using zebrafish loss of function models combined with in vivo cell biology and proteomic approaches, we identified the endoplasmic reticulum chaperone, BiP, as a novel target of the E3 ubiquitin ligase atrogin-1. A loss in atrogin-1 results in an accumulation of BiP, leading to impaired mitochondrial dynamics and a subsequent loss in muscle fibre integrity. We further implicate a disruption in atrogin-1 mediated BiP regulation in the pathogenesis of Duchenne Muscular Dystrophy. We reveal that BiP is not only upregulated in Duchenne Muscular Dystrophy, but its inhibition using pharmacological strategies, or by upregulating atrogin-1, significantly ameliorates pathology in a zebrafish model of Duchenne Muscular Dystrophy. Collectively, our data implicates a novel disease axis in the pathogenesis of Duchenne Muscular Dystrophy, and highlights atrogin-1’s essential role in maintaining muscle homeostasis.
Project description:Autopsy and biopsy muscle and heart tissue was collected from consented human subjects with and without confirmed myotonic dystrophy type 1, myotonic dystrophy type 2, or Duchenne muscular dystrophy. RNA was isolated for preparation of RNAseq libraries and sequenced on the Illumina platform.