(1295-D) Functional Phenotypic Excitation of Human iPSC-derived Spinal Motor Neurons Cultures from Amyotrophic Lateral Sclerosis Patients
Tuesday, February 6, 2024
2:00 PM – 3:00 PM EST
Location: Exhibit Halls AB
Abstract: Amyotrophic lateral sclerosis, ALS, is a fatal disease with not fully understood disease mechanisms. Therefore, phenotypic disease models are needed for the development of new therapies. The disease occurs in familial and sporadic forms, fALS and sALS. Although only about 10% of cases are familial with a known hereditary origin, they are important for disease modeling. Known fALS forms have mutations in the SOD1, C9orf72, TDP-43, FUS, and other genes. Human-induced pluripotent stem cells with fALS mutations can be differentiated toward spinal motor neurons. They are canonical disease models that reflect phenotypic disease symptoms. In our hands, iPSC-derived spinal motor neurons with a SOD1 D90A, a SOD1 A4V mutation, a C9orf72 mutation, a TDP43-G298S, and a TDP43 A384V mutation could be cultivated on microelectrode array plates for 14 to 28 days. No difference in survivability between diseased and wild-type cells was observed. First, electrophysiological activity can be observed after 7 days and lasts more than 5 weeks. After 14 days in vitro, a reliable hyperexcitation of the disease motor neurons compared to the wild-type neurons can be observed for C9orf72 and SOD1 mutated forms but not for the TDP43 mutated forms. Riluzole 2 µM applied on days 8 and 11 in vitro with medium change caused a reliable reduction of hyperexcitation after 14 days in vitro in three different models: with C9orf72 and SOD1 motor neurons and in TDP43 mutations, we saw any effect of riluzole. Surprisingly TDP-43 mutation cell lines also showed a hyperexcitation after more extended cultivation of more than 20 DIV. The excitation state of diseased ALS motor neurons can deliver new insights for potential treatment strategies.