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Sustained Depolarization of the Resting Membrane Potential Regulates Muscle Progenitor Cell Growth and Maintains Stem Cell Identity in vitro

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title
Sustained Depolarization of the Resting Membrane Potential Regulates Muscle Progenitor Cell Growth and Maintains Stem Cell Identity in vitro
author
Fennelly, Colin Jeffrey
abstract
It is important to maintain the myogenic properties of muscle progenitor cells (MPCs) during in vitro expansion for stem cell therapies and tissue engineering applications. Controlling cell fate for biomedical interventions will require insight on all aspects that influence cellular properties. The resting membrane potential (Vmem) has proven to be a key parameter involved in cell proliferation, migration and differentiation. This current work is focused on elucidating the impact of sustained depolarization on MPC growth and differentiation in vitro. Cultures were treated with either potassium gluconate or the sodium-potassium pump blocker ouabain and evaluated for proliferation, DNA content using propidum iodide staining, and expression of myogenic markers. Cell proliferation measurements showed a stimulatory effect with lower concentrations of both agents, but higher concentrations strongly inhibited growth. This impairment was transient and MPCs recovered after the treatments were removed. Cell cycle analysis with flow cytometry showed that depolarization resulted in an increase in the number of cells in S phases, but higher concentrations of potassium gluconate or ouabain arrested cells at G1 and G2, respectively Immunostaining and light microscopy demonstrated that sustained depolarization delayed myotube formation and maintained a higher population of cells expressing the muscle stem cell marker Pax 7. Taken together, this work suggests that transmembrane voltage gradients can be used as a powerful regulator of MPC growth and differentiation in vitro. Examination of how these physiological parameters modulate cell behavior will reveal a new set of tools that can be capitalized on in tissue engineering and regenerative medicine.
subject
Bioelectricity
Cell Cycle
Muscle Stem Cell
Ouabain
Regenerative Medicine
Tissue Engineering
contributor
Soker, Shay (committee chair)
Criswell, Tracy (committee member)
Levin, Michael (committee member)
date
2015-06-23T08:36:02Z (accessioned)
2015 (issued)
degree
Molecular Medicine and Translational Science (discipline)
embargo
forever (terms)
10000-01-01 (liftdate)
identifier
http://hdl.handle.net/10339/57192 (uri)
language
en (iso)
publisher
Wake Forest University
type
Thesis

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