The goal of regenerative medicine is to restore form and function to damaged and aging tissues. Muscle stem cells (MuSCs), also known as satellite cells, are responsible for maintenance and regeneration of skeletal muscle mass. We showed that MuSCs in aged muscles have inherent defects in their quiescence and self-renewal mechanisms, and prematurely senesce and differentiate. Our laboratory has established methods to characterize murine MuSCs by flow cytometry in conjunction with in vivo functional assays and has been able to successfully culture MuSCs ex-vivo in artificial stem cell niches that recapitulate the biophysical environment in which muscle stem cells reside. Here we propose to discern the role of extrinsic factors within or near the niche in modulating MuSC function during aging. Critical to the approach is single- cell analysis, as the behavior of slow proliferating MuSC may be masked by more rapidly proliferating progenitors and the MuSC population, though highly enriched, is heterogeneous and contains multiple subsets based on expression profiles, signaling and functional studies. We will capitalize on two single-cell technologies: (a) a bioengineered culture platform that supports maintenance of MuSC phenotype ex-vivo and long-term single-cell lineage tracking by time-lapse microscopy and (b) single cell mass cytometry, which allows high-throughput analysis of multiple biological cell surface and intracellular markers with single-cell resolution enabling an unbiased approach to the identification of novel subsets within a complex cell population. We will compare MuSCs from young and aged tissues, which have inherently different quiescence and self-renewal capacities.
We aim (1) to identify extrinsic factors that regulate MuSC fate in vitro. A family of cytokines identified in a 660-peptide library of secreted and transmembrane ectodomain proteins will be assayed for their potential to alter MuSC proliferation and phenotype; (2) to characterize specific members of the family of cytokines that regulate MuSC quiescence, asymmetric, or symmetric self- renewal to alter cell fate; (3) to elucidate the MuSC subsets and signaling networks stimulated by this cytokine family. We will employ single-cell mass cytometry to resolve distinct functional subsets of MuSCs, investigate how these subsets differentially activate signaling networks in response to extrinsic quiescence, proliferation, and commitment-inducing stimulation by the cytokine family members, and determine how those differences affect MuSC contributions to regeneration and strength. Together, these studies will provide insights into the role of extrinsic factors in the stem cell microenvironment on stem cell function and suggest novel therapeutic approaches to muscle degenerative diseases and muscle aging.
The ability of the resident muscle stem cell population to maintain and repair skeletal muscle progressively declines in the eldery, severely affecting muscle strength, mobility and quality of life. Here we will capitalize on our extensive experience in the isolation, culture and transplantation of muscle stem cells in mice. Additionally, we will develop novel technologies to test the effects of micro environmental proteins on young and aged muscle stem cell function in regeneration in order to identify novel therapeutics.
|Sampath, Srinath C; Sampath, Srihari C; Ho, Andrew T V et al. (2018) Induction of muscle stem cell quiescence by the secreted niche factor Oncostatin M. Nat Commun 9:1531|
|Mai, Thach; Markov, Glenn J; Brady, Jennifer J et al. (2018) NKX3-1 is required for induced pluripotent stem cell reprogramming and can replace OCT4 in mouse and human iPSC induction. Nat Cell Biol 20:900-908|
|Madl, Christopher M; Heilshorn, Sarah C; Blau, Helen M (2018) Bioengineering strategies to accelerate stem cell therapeutics. Nature 557:335-342|
|Ulman, Vladimír; Maška, Martin; Magnusson, Klas E G et al. (2017) An objective comparison of cell-tracking algorithms. Nat Methods 14:1141-1152|
|Sleep, Eduard; Cosgrove, Benjamin D; McClendon, Mark T et al. (2017) Injectable biomimetic liquid crystalline scaffolds enhance muscle stem cell transplantation. Proc Natl Acad Sci U S A 114:E7919-E7928|
|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|
|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|
|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|
|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|
|Magnusson, Klas E G; Jalden, Joakim; Gilbert, Penney M et al. (2015) Global linking of cell tracks using the Viterbi algorithm. IEEE Trans Med Imaging 34:911-29|
Showing the most recent 10 out of 70 publications