Duchenne Muscular Dystrophy (DMD), the most common inherited muscular dystrophy, leads to progressive muscle weakness and death by the third decade of life. A conundrum is that the mouse model that has the same genetic defect, absence of dystrophin, does not mimic the human disease, which has limited the development of efficacious therapies. Recently, we hypothesized that telomere length differences between mice and humans could account for this discrepancy and developed a mouse model that lacks dystrophin and has shortened telomeres (mdx/mTRKO ). This model exhibits all of the major pathological hallmarks of human DMD. In particular, the mdx/mTRKO mice exhibit impaired regeneration and progressive muscle wasting due to functional defects in their muscle stem cells (MuSCs). Here we address a major challenge: MuSCs are known to be functionally heterogeneous, but the nature of their diversity has yet to be characterized which is essential for targeting therapies. We propose to capitalize on two groundbreaking technologies developed in our laboratories to elucidate the defects in the signaling networks that underlie the dysfunctional MuSC subsets in a manner previously not possible. To this end we will use novel (1) state-of-the-art single cell mass cytometry (CyTOF) and (2) artificial bioengineered stem cell niches. The CyTOF is uniquely suited to identify dysfunctional MuSC subsets. Using new parameters identified by CyTOF, we will purify these subsets and in conjunction with our biomimetic hydrogel microwell platform perform single-cell fate mapping. The combination of highly multivariate single cell CyTOF analyses and real time single cell time-lapse imaging will reveal dysfunctional signaling profiles and behaviors within subsets of stem cells. Defects in signaling pathways identified in specific MuSC subsets in the mouse model will be validated in MuSCs isolated from human DMD patient samples. These subsets and pathways can then be targeted, leading to novel therapeutic strategies that will enhance muscle fiber repair in DMD patients.

Public Health Relevance

Duchenne Muscular Dystrophy (DMD) is a lethal progressive muscle wasting disease, caused by mutations in the dystrophin gene, which culminates in death by the third decade of life. Our laboratory developed a new mouse model that recapitulates the human disease and discovered that the impaired regeneration process is due to a defect in the muscle stem cells. Here we propose to use two cutting-edge technologies, specifically artificial stem cell niches in combination with single-cell mass cytometry, to elucidate previously unidentified dysfunctional signaling pathways in MuSCs from mice and human DMD biopsies, which will constitute novel therapeutic targets.

National Institute of Health (NIH)
National Institute of Neurological Disorders and Stroke (NINDS)
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Special Emphasis Panel (ZNS1-SRB-N (06))
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Nuckolls, Glen H
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Stanford University
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Madl, Christopher M; Heilshorn, Sarah C; Blau, Helen M (2018) Bioengineering strategies to accelerate stem cell therapeutics. Nature 557:335-342
Burns, Tyler J; Frei, Andreas P; Gherardini, Pier F et al. (2017) High-throughput precision measurement of subcellular localization in single cells. Cytometry A 91:180-189
Theodoris, Christina V; Mourkioti, Foteini; Huang, Yu et al. (2017) Long telomeres protect against age-dependent cardiac disease caused by NOTCH1 haploinsufficiency. J Clin Invest 127:1683-1688
Esteva, Andre; Kuprel, Brett; Novoa, Roberto A et al. (2017) Dermatologist-level classification of skin cancer with deep neural networks. Nature 542:115-118
Porpiglia, Ermelinda; Samusik, Nikolay; Ho, Andrew Tri Van et al. (2017) High-resolution myogenic lineage mapping by single-cell mass cytometry. Nat Cell Biol 19:558-567
Angst, Martin S; Fragiadakis, Gabriela K; Gaudillière, Brice et al. (2016) In Reply. Anesthesiology 124:1414-5
Chang, Alex Chia Yu; Ong, Sang-Ging; LaGory, Edward L et al. (2016) Telomere shortening and metabolic compromise underlie dystrophic cardiomyopathy. Proc Natl Acad Sci U S A 113:13120-13125
Burridge, Paul W; Li, Yong Fuga; Matsa, Elena et al. (2016) Human induced pluripotent stem cell-derived cardiomyocytes recapitulate the predilection of breast cancer patients to doxorubicin-induced cardiotoxicity. Nat Med 22:547-56
Anchang, Benedict; Hart, Tom D P; Bendall, Sean C et al. (2016) Visualization and cellular hierarchy inference of single-cell data using SPADE. Nat Protoc 11:1264-79
Behbehani, Gregory K; Samusik, Nikolay; Bjornson, Zach B et al. (2015) Mass Cytometric Functional Profiling of Acute Myeloid Leukemia Defines Cell-Cycle and Immunophenotypic Properties That Correlate with Known Responses to Therapy. Cancer Discov 5:988-1003

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