Table 1. Summary of studies using human pluripotent stem cells for in vitro models of the NMJ.
Only studies with one or both cell types derived from human embryonic or induced pluripotent stem cells were considered, not studies using adult stem cell-derived models. The characterization/analysis column describes what assays they used to confirm NMJ structure and functionality.
| Study | Motor neuron source | Skeletal muscle source | Characterization/ Analysis | Disease modeling |
|---|---|---|---|---|
| Marteyn et al. 2011 | hESC-derived | Human Mu2bR3 cells | Immunocytochemistry | Myotonic dystrophy type I (hESC-derived motor neurons) |
| Corti et al. 2012 | hiPSC-derived | Human myoblasts | Immunocytochemistry | SMA (hiPSC-derived motor neurons from SMA patients and genetically corrected controls) |
| Demestre et al. 2015 | hiPSC-derived | hiPSC-derived | Immunocytochemistry | N/A |
| Maury et al. 2015 | hiPSCs and hESCs-derived | Human myoblasts | Immunocytochemistry | N/A |
| Shimojo et al. 2015 | hESC-derived | Human myoblasts | Immunocytochemistry | N/A |
| Yoshida et al. 2015 | hiPSC-derived | Mouse C2C12 cells | Immunocytochemistry | SMA (hiPSC-derived motor neurons from SMA patients and controls) |
| Steinbeck et al. 2016 | hESC-derived, transduced with Channelrhodopsin2 | Human primary myoblasts from adult and fetal donors | Immunocytochemistry. Optogenetic stimulation, blocked with vercuronium. Calcium imaging and microelectrode recordings | Myasthenia gravis (Added MG patient IgG and complement) |
| Maffioletti et al. 2018 | hiPSC-derived | hiPSC-derived | Immunocytochemistry | 3D muscle constructs from hiPSCs of patients with Duchenne, limb-girdle type 2D, and LMNA-related muscular dystrophies and healthy donors (but control lines only for co-cultures) |
| Osaki et al. 2018 | hiPSC- and ESC-derived, transfected with channelrhodopsin-2 | hiPSC-derived skeletal myoblasts in 3D collagen/Matrigel mixture | Immunocytochemistry. Glutamic acid, electrical, and light stimulation. Contractions blocked with BTX, visualized with calcium imaging, and quantified by pillar deflection. | Two models of ALS: 1) Excess glutamic acid; 2) motor neurons derived from sporadic ALS patient iPSCs |
| Santhanam et al. 2018 | Human spinal cord stem cell or iPSC-derived | Human skeletal muscle myoblasts | Immunocytochemistry, electrical stimulation and treatment with NMJ toxins | N/A |
| Bakooshli et al. 2019 | hESC-derived | Primary myogenic progenitors from patient biopsies | Immunocytochemistry. Glutamate-induced contractions viewed by calcium imaging (cells were transduced with GCaMP6 calcium reporter) recorded with electrophysiology and inhibited by BOTOX and d-tubocurarine | Myasthenia gravis (treated co-culture with IgG from MG patients) and congenital myasthenic syndromes (Waglerin-1 treatment to block the AChR epsilon subunit) |
| Lin et al. 2019 | hiPSC and hESC-derived, with channelrhodopsin | hiPSC-derived | Immunocytochemistry and electron microscopy. Contractions stimulated by light, viewed by calcium imaging (Fluo-8), blocked with dantrolene or curare | SMA (used shRNA to knock down SMN) |
| Picchiarelli et al. 2019 | hiPSC-derived | hiPSC-derived | Immunocytochemistry | Amyotrophic lateral sclerosis (mutations in FUS) |
| Vila et al. 2019 | Human primary muscle cells reprogrammed to iPSCs and transfected with channelrhodopsin-2 | Human skeletal muscle stem cells | Immunocytochemistry. Electrical and light stimulation of contractions, blocked with BTX treatment | Myasthenia gravis (added serum from myasthenia gravis patients) |
| Guo et al. 2020 | hiPSC-derived | hiPSC-derived | Immunocytochemistry and electrophysiology. | N/A |
| Martins et al. 2020 | hESC and hiPSC-derived axial stem cells | hESC and hiPSC-derived axial stem cells | Immunocytochemistry and electron microscopy. Measured spontaneous and glutamate-stimulated contractions with MEA and visualized with calcium imaging. Blocked with curare. | Myasthenia gravis (treated with MG patient serum) |
| Mazaleyrat et al. 2020 | hiPSC-derived codifferentiation | hiPSC-derived codifferentiation | Immunocytochemistry, electron microscopy, RNA sequencing, calcium imaging, contraction stimulation with glutamate and inhibition with BTX and tetrodotoxin. Also drug tested muscle relaxants. | Duchenne muscular dystrophy, facio scapulo humeral dystrophy, myotonic dystrophy, limb girdle muscular dystrophy type 2A |
Abbreviations: hESC, human embryonic stem cell; hiPSC, human induced pluripotent stem cell; SMA, spinal muscular atrophy; N/A, not applicable; MG, myasthenia gravis; LMNA, lamin A/C; BTX, bungarotoxin; ALS, amyotrophic lateral sclerosis; NMJ, neuromuscular junction; IgG, immunoglobulin; AchR, acetylcholine receptor; shRNA, short hairpin ribonucleic acid; SMN, survival motor neuron; MEA, multielectrode array.