Stem Cells: Advancing Treatment for Neuromuscular Disease
Neuromuscular diseases come in many different forms and arise from many different causes, but they all have one aspect in common: they make everyday movement a challenge for those affected. Those living with neuromuscular diseases may experience muscle pain, paralysis, or twitching, all of which can make it incredibly difficult to accomplish everyday tasks. Unfortunately, another commonality between neuromuscular diseases is that they are often incurable.1 Recent breakthroughs using stem cells may provide scientists with the tools they need to develop better treatment options for neuromuscular diseases.
Neuromuscular diseases represent a broad class of conditions affecting the movement of voluntary muscles.2 Muscle twitches, cramps, and aches are all symptoms caused by the breakdown of nerves controlling voluntary muscles, making it difficult for an individual to take control of their own movements.2 This is the case for diseases such as Pompe disease, a metabolic storage disorder3, and muscular dystrophy. Duchenne muscular dystrophy, the most common form, is a genetic disorder that occurs in men due to a mutation on the X chromosome.4 The mutation occurs in a gene encoding for the dystrophin protein, which plays a necessary role in maintaining muscle membrane integrity.1 Without this protein, muscle membranes lose their strength, and, as a result, patients are usually confined to a wheelchair.1
There are no current treatments for diseases like Duchenne muscular dystrophy, although there are methods of managing symptoms. Engaging in activities such as physical therapy and exercise can help to build strength and control muscle twitches.4 Additionally, drugs such as corticosteroids are often prescribed in the hope that this medication will slow the rate of muscle weakness and deterioration.4 Drugs and exercise regimes are not always sufficient, and advancements are still necessary to provide better care for individuals with neuromuscular diseases.
Recent research conducted in the United States aims to improve the outlook of muscular dystrophy treatment through the use of bioengineering and gene editing. Scientists at Duke University have recently developed skeletal muscle cells directly from human pluripotent stem cells.5 These new methods allow skeletal muscle to be produced using a blood sample taken from a patient with muscular dystrophy.5 Tests can then be done on these manufactured muscle cells instead of invasively taking muscle biopsies from the patients. Additionally, research at the University of California, Los Angeles, has utilized gene-editing techniques to restore the dystrophin protein to blood samples from muscular dystrophy patients. Cells are taken from patients with Duchenne muscular dystrophy and pluripotent stem cells are genetically altered through the use of CRISPR-Cas9 gene editing to remove the mutation in the dystrophin gene.6 Using these methods, researchers were able to restore dystrophin function in mouse models, proving that gene therapy may be an effective treatment modality for muscular dystrophy.6 By developing an efficient method for engineering human skeletal muscle cells and utilizing gene therapy to restore protein function, these groups of researchers have unlocked the key to a stable supply of muscle cells that can be used to model and potentially treat diseases such as Duchenne muscular dystrophy.
Neuromuscular diseases, such as Duchenne muscular dystrophy, have a severe impact on individuals and families of those who have been diagnosed. Individuals are often wheelchair bound and unable to fully control their motions. In some cases, diseases can be managed through exercise or the use of certain prescriptions, but, despite the fact that treatments for diseases like muscular dystrophy are desperately needed, currently none exist. In order for treatments to be developed, skeletal muscle tissue is needed for testing. Current research has developed a method for manufacturing these cells, as well as potentially editing the genomes of affected individuals, opening doors to the possibilities of new treatments for neuromuscular diseases.
1. Rehabilitation Management of Neuromuscular Disease: Overview, Clinical Characteristics of Neuromuscular Disease, Management of Neuromuscular Disease. December 2017. https://emedicine.medscape.com/article/321397-overview.
2. Neuromuscular Disorders. https://medlineplus.gov/neuromusculardisorders.html.
3. Reference GH. Pompe disease. Genetics Home Reference. https://ghr.nlm.nih.gov/condition/pompe-disease. Accessed January 27, 2018.
4. Duchenne Muscular Dystrophy - NORD (National Organization for Rare Disorders). NORD Natl Organ Rare Disord. https://rarediseases.org/rare-diseases/duchenne-muscular-dystrophy/.
5. Rao L, Qian Y, Khodabukus A, Ribar T, Bursac N. Engineering human pluripotent stem cells into a functional skeletal muscle tissue. Nat Commun. 2018;9(1):126. doi:10.1038/s41467-017-02636-4
6. Hicks MR, Hiserodt J, Paras K, et al. ERBB3 and NGFR mark a distinct skeletal muscle progenitor cell in human development and hPSCs. Nat Cell Biol. 2018;20(1):46. doi:10.1038/s41556-017-0010-2
Cite This Article:
Coles V., Chan G., Palczewski K., Lewis K., Ho J. Stem Cells: Advancing Treatment for Neuromuscular Disease. Illustrated by W. Zhang. Rare Disease Review. January 2019. DOI:10.13140/RG.2.2.12457.24164.