Table 1_Dynamic changes in excitability and viability of sporadic and SOD1-related amyotrophic lateral sclerosis iPSC-derived motor neurons.docx

ObjectiveTo explore the dynamic changes in excitability and viability of induced pluripotent stem cells (iPSC)-derived motor neurons from sporadic amyotrophic lateral sclerosis (ALS) and compare them with SOD1-related ALS patients and healthy control.
MethodsPeripheral blood samples were collected from ALS patients and healthy controls (HC) to establish the iPSC-derived motor neurons (MNs). Whole-cell patch-clamp recordings at different culture stages was made using an Axopatch 700B amplifier in combination with pClamp 11 software (Molecular Devices). The frequency of action potentials (APs) was recorded. Additionally, Terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) Nick-End Labeling (TUNEL) was used to assess the apoptosis of MNs.
ResultsALS patient-derived MNs exhibited significantly higher firing rates compared to HCs at both 4–7 weeks (p = 0.004) and 7–9 weeks (p = 0.009). Further analysis revealed that SOD1-derived MNs showed significantly higher firing frequencies than sALS (p = 0.009) and HCs (p < 0.001) in 4–7 weeks. In 7–9 weeks, it remained significant between SOD1 and HC-derived MNs (p = 0.015), but became insignificant between SOD1 and sALS (p = 0.855). The apoptotic rate of sALS (Day 30: 61.37% ± 9.63%; Day 60: 78.41% ± 6.63%) and SOD1 (Day 30: 73.69% ± 8.81%; Day 60: 60.37% ± 11.53%) -derived MNs was significantly higher than those of HCs at both Day 30 (30.72% ± 7.57%) and Day 60 (50.85% ± 19.36%) (p < 0.001).
ConclusionMNs derived from both patients with mutant SOD1 and sporadic ALS exhibited increased excitability compared to HCs. The increased excitability of MNs derived from ALS patients with mutant SOD1 occurred earlier, and over time, became consistent with the excitability observed in MNs derived from sporadic ALS. The apoptosis rates of MNs showed similar trends. iPSC-derived MNs from both sporadic and mutant ALS may serve as useful cell models for ALS in future studies.