Myostatin is both a regulator of muscle growth and a stimulator of muscle fibroblasts to proliferate; and there is an accumulating body of evidence that demonstrates inhibition of myostatin/ActRIIB signaling can ameliorate the pathology and function of dystrophic muscle in preclinical models of Duchene muscular dystrophy.
Sphingosine-1-Phosphate Enhances Satellite Cell Activation in Dystrophic Muscles through a S1PR2/STAT3 Signaling Pathway
A recent publication from Dr. Julie Saba et al., (Children’s Hospital Oakland Research Institute, Oakland, California, reference http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0037218) highlights the role played by the signaling lipid sphingosine-1-phosphate (S1P) in controlling the fate of satellite cells (muscle stem cells) in mdx mice.
Objective: To determine whether pentoxifylline (PTX) slows the decline of muscle strength and function in ambulatory boys with Duchenne muscular dystrophy (DMD).
microRNAs (miRNAs) are noncoding RNAs that regulate gene expression in post-transcriptional fashion, and emerging studies support their importance in a multitude of physiological and pathological processes. Here, we describe the regulation and function of miR-29 in Duchenne muscular dystrophy (DMD) and its potential use as therapeutic target.
Therapeutic potential of PEGylated insulin-like growth factor I for skeletal muscle disease evaluated in two murine models of muscular dystrophy
Duchenne muscular dystrophy (DMD) is a fatal monogenetic disease with affected males displaying severe and progressive muscle wasting and weakness eventually leading to premature death. Possible therapeutic benefits of insulin-like growth factor I (IGF-I) have been studied extensively in various models of muscle disease and DMD with IGF-I as a mediator of improved skeletal muscle regeneration by enhancing myoblast proliferation and differentiation.
Rescue of severely affected dystrophin/utrophin-deficient mice through scAAV-U7snRNA-mediated exon skipping
Comments by Chief Scientific Officer, Michael Kelly: Antisense-mediated exon skipping drugs are presently the most advanced therapeutics for the treatment of DMD; with drug candidates in Phase 2 and Phase 3 clinical trials. While the current antisense approach is an important breakthrough in the treatment of the disease, it suffers from a major limitation in its ability to restore dystrophin expression in both diaphragm and cardiac muscle.The work described by Goyenvalle and Davis et al. in
Human Molecular Genetics, directly addresses this limitation in a relevant mouse model by using an alternate technology (AAV delivered small nuclear RNAâ€™s) to distribute the antisense and elicit exon skipping. In this paper, the authors demonstrate that widespread dystrophin expression was restored in all muscles examined and report a remarkable rescue of the dystrophic pathology in utrophin/dystrophin double knockout mouse.
Comments by Chief Scientific Officer, Michael Kelly: This paper demonstrates that the regulation of quiescence, i.e. keeping cells in a resting (non-dividing) state is dependent on specific miRNAâ€™s. In this report, Rando et al, identify a specific miRNA (miR-489) as a key regulator of muscle stem-cell quiescence and this opens the door to future studies that could lead to strategies that could be used to target new muscle growth.
Dystrophin quantification and clinical correlations in Becker muscular dystrophy: implications for clinical trials
Duchenne muscular dystrophy is caused by mutations in the DMD gene that disrupt the open reading frame and prevent the full translation of its protein product, dystrophin. Restoration of the open reading frame and dystrophin production can be achieved by exon skipping using antisense oligonucleotides targeted to splicing elements. This approach aims to transform the Duchenne muscular dystrophy phenotype to that of the milder disorder, Becker muscular dystrophy, typically caused by in-frame dystrophin deletions that allow the production of an internally deleted but partially functional dystrophin.
Researchers report on the use of genetically modified stem cells to generate new muscle fibers and improve disease-associated muscle function and phenotype in a mouse model of Duchenne muscular dystrophy (DMD).
The vision of the Department of Defense Duchenne Muscular Dystrophy Research Program (DMDRP) is to extend and improve the function, quality of life and life span for all individuals diagnosed with DMD. This program is administered by the US Army Medical Research and Materiel Command through the Office of the Congressionally Directed Medical Research Programs (CDMRP).