Muscular Dystrophy and Stem Cell Therapy
What is Muscular Dystrophy?
Muscular Dystrophy (MD) refers to a group of hereditary muscle diseases that weakens the muscles that move the human body.
Muscular dystrophies are characterized by progressive skeletal muscle weakness, defects in muscle proteins, and the death of muscle cells and tissue.
Nine diseases including Duchenne, Becker, limb girdle, congenital, facioscapulohumeral, myotonic, oculopharyngeal, distal, and Emery-Dreifuss are always classified as muscular dystrophy but there are more than 100 diseases in total with similarities to muscular dystrophy.
Most types of MD are multi-system disorders with manifestations in body systems including the heart, gastrointestinal and nervous systems, endocrine glands, skin, eyes and even brain.
The condition may also lead to mood swings and learning difficulties.
Effective myotube formation in human adipose tissue-derived stem cells expressing dystrophin and myosin heavy chain by cellular fusion with mouse C2C12 myoblasts.
Biochem Biophys Res Commun. 2011 Apr 5;
Authors: Eom YW, Lee JE, Yang MS, Jang IK, Kim HE, Lee DH, Kim YJ, Park WJ, Kong JH, Shim KY, Lee JI, Kim HS
Stem cell therapy for muscular dystrophies requires stem cells that are able to participate in the formation of new muscle fibers. However, the differentiation steps that are the most critical for this process are not clear.
We investigated the myogenic phases of human adipose tissue-derived stem cells (hASCs) step by step and the capability of myotube formation according to the differentiation phase by cellular fusion with mouse myoblast C2C12 cells.
In hASCs treated with 5-azacytidine and fibroblast growth factor-2 (FGF-2) for 1day, the early differentiation step to express MyoD and myogenin was induced by FGF-2 treatment for 6days. Dystrophin and myosin heavy chain (MyHC) expression was induced by hASC conditioned medium in the late differentiation step.
Myotubes were observed only in hASCs undergoing the late differentiation step by cellular fusion with C2C12 cells. In contrast, hASCs that were normal or in the early stage were not involved in myotube formation.
Our results indicate that stem cells expressing dystrophin and MyHC are more suitable for myotube formation by co-culture with myoblasts than normal or early differentiated stem cells expressing MyoD and myogenin.
PMID: 21473854 [PubMed - as supplied by publisher]
Genomic integration of the full-length dystrophin coding sequence in Duchenne muscular dystrophy induced pluripotent stem cells.
Genomic integration of the full-length dystrophin coding sequence in Duchenne muscular dystrophy induced pluripotent stem cells. Biotechnol J. 2017 Jan 31;: Authors: Farruggio AP, Bhakta MS, du Bois H, Ma J, P Calos M Abstract We developed plasmid vectors that express the full-length human dystrophin coding sequence in human cells. Dystrophin, the protein mutated in Duchenne muscular dystrophy, is extraordinarily large, providing challenges for cloning and plasmid production in E. coli. We expressed dystrophin from the strong, widely expressed CAG promoter, along with co-transcribed luciferase and mCherry marker genes useful for tracking plasmid expression. Introns were added at the 3' and 5' ends of the dystrophin sequence to prevent translation in E. coli, resulting in improved plasmid yield. Stability and yield were further improved by employing a lower-copy number plasmid origin of replication. The dystrophin plasmids also carried an attB site recognized by phage phiC31 integrase, enabling the plasmids to be integrated into the human genome at preferred locations by phiC31 integrase. We demonstrated single-copy integration of plasmid DNA into the genome and production of human dystrophin in the human 293 cell line, as well as in induced pluripotent stem cells derived from a patient with Duchenne muscular dystrophy. Plasmid-mediated dystrophin expression was also demonstrated in mouse muscle. The dystrophin expression plasmids described here will be useful in cell and gene therapy studies aimed at ameliorating Duchenne muscular dystrophy. PMID: 28139886 [PubMed - as supplied by publisher]Read more...