title: Motoneurons derived from induced pluripotent stem cells develop mature phenotypes typical of endogenous spinal motoneurons.
abstract: Induced pluripotent cell-derived motoneurons (iPSCMNs) are sought for use in cell replacement therapies and treatment strategies for motoneuron diseases such as amyotrophic lateral sclerosis (ALS). However, much remains unknown about the physiological properties of iPSCMNs and how they compare with endogenous spinal motoneurons or embryonic stem cell-derived motoneurons (ESCMNs). In the present study, we first used a proteomic approach and compared protein expression profiles between iPSCMNs and ESCMNs to show that <4% of the proteins identified were differentially regulated. Like ESCs, we found that mouse iPSCs treated with retinoic acid and a smoothened agonist differentiated into motoneurons expressing the LIM homeodomain protein Lhx3. When transplanted into the neural tube of developing chick embryos, iPSCMNs selectively targeted muscles normally innervated by Lhx3 motoneurons. In vitro studies showed that iPSCMNs form anatomically mature and functional neuromuscular junctions (NMJs) when cocultured with chick myofibers for several weeks. Electrophysiologically, iPSCMNs developed passive membrane and firing characteristic typical of postnatal motoneurons after several weeks in culture. Finally, iPSCMNs grafted into transected mouse tibial nerve projected axons to denervated gastrocnemius muscle fibers, where they formed functional NMJs, restored contractile force. and attenuated denervation atrophy. Together, iPSCMNs possess many of the same cellular and physiological characteristics as ESCMNs and endogenous spinal motoneurons. These results further justify using iPSCMNs as a source of motoneurons for cell replacement therapies and to study motoneuron diseases such as ALS.
authors.affiliation: Department of Medical Neuroscience.
authors.forename: Jeremy S
authors.initials: JS
authors.lastname: Toma
authors.affiliation: Department of Medical Neuroscience.
authors.forename: Basavaraj C
authors.identifier: http://orcid.org/0000-0002-7776-4020
authors.initials: BC
authors.lastname: Shettar
authors.affiliation: Department of Medical Neuroscience.
authors.forename: Peter H
authors.initials: PH
authors.lastname: Chipman
authors.affiliation: National Research Council, Institute for Marine Biosciences, Nova Scotia, Canada B3H 3Z1.
authors.forename: Devanand M
authors.initials: DM
authors.lastname: Pinto
authors.affiliation: Department of Medical Neuroscience.
authors.forename: Joanna P
authors.initials: JP
authors.lastname: Borowska
authors.affiliation: Howard Hughes Medical Institute.
authors.forename: Justin K
authors.initials: JK
authors.lastname: Ichida
authors.affiliation: Department of Pharmacology, and Department of Surgery, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4R2.
authors.forename: James P
authors.initials: JP
authors.lastname: Fawcett
authors.affiliation: Department of Medical Neuroscience.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Howard Hughes Medical Institute, Harvard Stem Cell Institute, Department of Stem Cell and Regenerative Biology, and Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, and.
authors.forename: Kevin
authors.initials: K
authors.lastname: Eggan
authors.affiliation: Department of Medical Neuroscience, Department of Medicine (Neurology), vrafuse@dal.ca.
authors.forename: Victor F
authors.initials: VF
authors.lastname: Rafuse
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology; D002642:Chick Embryo; D057026:Induced Pluripotent Stem Cells / Q000166:cytology*; D060850:LIM-Homeodomain Proteins / Q000378:metabolism; D051379:Mice; D009046:Motor Neurons / Q000166:cytology*; D018482:Muscle, Skeletal / Q000166:cytology* / Q000502:physiology; D055495:Neurogenesis / Q000502:physiology*; D009469:Neuromuscular Junction / Q000166:cytology* / Q000502:physiology; D010641:Phenotype; D040901:Proteomics; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D060850:LIM-Homeodomain Proteins; C094898:Lhx3 protein; D014157:Transcription Factors
keywords: electrophysiology; iPS cells; motoneuron disease; motoneurons; proteomics; stem cells