Human Induced Pluripotent Stem Cell–Derived Motor Neuron Transplant for Neuromuscular Atrophy in a Mouse Model of Sciatic Nerve Injury

Abstract

IMPORTANCE Human motor neurons may be reliably derived from induced pluripotent stem cells (iPSCs). In vivo transplant studies of human iPSCs and their cellular derivatives are essential to gauging their clinical utility.OBJECTIVE To determine whether human iPSC-derived motor neurons can engraft in an immunodeficient mouse model of sciatic nerve injury. DESIGN, SETTING, AND SUBJECTSThis nonblinded interventional study with negative controls was performed at a biomedical research institute using an immunodeficient, transgenic mouse model. Induced pluripotent stem cell-derived motor neurons were cultured and differentiated. Cells were transplanted into 32 immunodeficient mice with sciatic nerve injury aged 6 to 15 weeks. Tissue analysis was performed at predetermined points after the mice were killed humanely. Animal experiments were performed from February 24, 2015, to May 2, 2016, and data were analyzed from April 7, 2015, to May 27, 2016.INTERVENTIONS Human iPSCs were used to derive motor neurons in vitro before transplant. MAIN OUTCOMES AND MEASURESEvidence of engraftment based on immunohistochemical analysis (primary outcome measure); evidence of neurite outgrowth and neuromuscular junction formation (secondary outcome measure); therapeutic effect based on wet muscle mass preservation and/or electrophysiological evidence of nerve and muscle function (exploratory end point).RESULTS In 13 of the 32 mice undergoing the experiment, human iPSC-derived motor neurons successfully engrafted and extended neurites to target denervated muscle. Human iPSC-derived motor neurons reduced denervation-induced muscular atrophy (mean [SD] muscle mass preservation, 54.2% [4.0%]) compared with negative controls (mean [SD] muscle mass preservation, 33.4% [2.3%]) (P = .04). No electrophysiological evidence of muscle recovery was found.CONCLUSIONS AND RELEVANCE Human iPSC-derived motor neurons may have future use in the treatment of peripheral motor nerve injury, including facial paralysis.LEVEL OF EVIDENCE NA.

Comparative genomic analysis of embryonic, lineage-converted, and stem cell-derived motor neurons

“…In particular, the realization that Oct4, Sox2, Klf4 and Myc can reprogram easily obtained cell types to pluripotency has fueled new approaches to studying human disease. By reprogramming cells from individuals with genetic forms of disease into induced pluripotent stem cells (iPSCs) or somatic cell types, it has become possible to understand and develop interventions for cell type-specific pathologies that previously could have only been studied using postmortem tissues (Blanchard et al, 2015;Brennand et al, 2011;Ichida et al, 2009Ichida et al, , 2014Ichida and Kiskinis, 2015;Kiskinis et al, 2014;Kramer et al, 2018;Mertens et al, 2015;Pepper et al, 2017;Shi et al, 2018;Son et al, 2011;Takahashi et al, 2007a,b;Toma et al, 2015;Wainger et al, 2015;Wen et al, 2014;Wilkinson et al, 2018;Xu et al, 2015;Zhang et al, 2015;Zhao et al, 2015).…”

Endogenous Cell Type–Specific Disrupted in Schizophrenia 1 Interactomes Reveal Protein Networks Associated With Neurodevelopmental Disorders

“…The control 03231 iPSC line was generated from a lymphoblastoid cell line derived from a healthy 56 year-old male (NINDS repository, ND03231) as previously described (34). For gene-editing, guide RNAs were cloned into pSpCas9(BB)-2A-Puro (PX459) V2.0 and the homologous recombination donor vector was constructed using the pFETCH_Donor plasmid (35,36).…”

Concise Review: Human-Animal Neurological Chimeras: Humanized Animals or Human Cells in an Animal?

“…Both ESCs and iPSCs differentiated toward NS/PCs or glial cells have been transplanted directly into the spinal cord of rodent models of ALS. Human cells have been observed within transplanted animals up to 9 months post‐transplantation and have been shown to form neurites, axons, and even functional neuromuscular junctions . However, the terminal differentiation of these cells is variable.…”

“…Two separate groups observed that up to 1,600,000 human cells integrated into the spinal cord of mutant SOD1 transgenic rodents up to 9 months post‐transplant, with the majority of transplanted human cells differentiating toward astrocytes . Although some studies have shown grafted human neural stem cells to extend axons and innervate muscle, it is likely that the benefits seen are at least in part due to the neuroprotective mechanisms exerted by the engrafted human cells .…”