Generation and characterization of motor neuron disease model derived from hPSC

Abstract

Motor neurons within the spinal cord are essential cells with complex and long axonal structures that connect to muscle cells and control movement. Recent research has reported that the neural tube of the spinal cord is created from neuromesodermal progenitors (NMPs) with bipotentiality, and motor neurons are differentiated from them. Many studies are underway to develop motor neuron models with these unique structures using human pluripotent stem cells (hPSCs). However, techniques for inducing differentiation of motor neurons using hPSCs have shown low differentiation efficiency and problems with ambiguous motor neuron cell identity. Therefore, in this study, I induced and verified the differentiation of high-efficiency motor neurons from NMP cells. I also tested the potential of C9ORF72-Amyotrophic Lateral Sclerosis (ALS) patient-derived NMP-human induced pluripotent stem cells (hiPSCs) as disease models, with efficiently generated motor neurons confirmed by subtype markers (FOXP1, ISL1, HB9, and ChAT) of motor neurons. I investigated gene changes related to RNA synthesis, cell clearance, and cell death in the disease models as preclinical indicators through initial gene analysis. Although disease-specific toxic proteins (dipeptide repeat, DPR) in the ALS mutant motor neuron model did not significantly increase at the time of maturation, I was able to detect some of genes reported to be relevant to the progression of the diseases altered in the ALS mutant model compared to the normal one. Additionally, I artificially induced an oxidative stress condition in cells with sodium arsenite, which is a reactive oxygen species (ROS) inducer and observed that motor axons of ALS model degenerate faster or more compared to the normal one. In conclusion, I have generated motor neurons with high-efficiency, uniform identity motor neuron through NMP cells and verified its disease-specific characteristics using the NMP-MN protocol as a disease model.