Speaker
Description
Epileptic disorders represent high burden diseases characterized by recurrent and unprovoked seizures, which are due to the excessive and hypersynchronous discharge of neuronal networks. Strikingly, 75% of epilepsies arise during childhood, such as developmental epileptic encephalopathies (DEEs), which are genetic conditions characterized by recurrent and drug-resistant seizures and by cognitive and developmental delays. Recently, de novo mutations in the gene encoding for hyperpolarization-activated cyclic nucleotide gated channel 1 (HCN1) have been associated with DEE24, representing a rare and severe DEE form. Noteworthy, HCN1 is present in cortical neurons, where it conducts an inward depolarizing current that contributes to the maintenance of their resting membrane potential. Even though mouse models for Hcn1 mutations have been generated, patient-specific in vitro models able to recapitulate the genetic landscape and human brain development are still missing. To this aim, we managed to reprogram somatic cells from three patients bearing different HCN1 mutations into human induced pluripotent stem cells (hiPSCs) and to differentiate them into cortical organoid models. Aiming at uncoupling the effects of HCN1 mutations on the phenotype from the patient-specific genetic background, we also leveraged isogenic hiPSCs lines genetically edited to insert the mutations under investigation. Interestingly, we observed that patient-derived cortical organoids present significantly decreased size compared to their wild-type (WT) counterpart, thus recapitulating the microcephalic phenotype observed in DEE24 patients. Preliminary analysis revealed profound alterations in neural progenitors of both patient-derived and genetically edited cortical organoids compared to WT samples. Strikingly, HCN1 mutant organoids displayed epileptic-like high-frequency calcium waves compared to their WT counterpart by calcium imaging. We are going to identify the molecular signature of DEE24-derived cortical organoids through transcriptomic analyses. Ultimately, our work will contribute to unveil the underlying pathogenic mechanisms and the genotype-phenotype relationship in DEE24, unprecedently providing personalized models to test potential therapies for this incurable disease.
| Author(s) | Elena Florio¹ *, Sara Mancinelli1, Edoardo Brandi2, Mohamed Hegazi3, Illia Simutin¹, Carla Marini4, Ilaria Rivolta5,6, Roberto Rusconi1,7, Alessandro Rosa2,8 and Simona Lodato1,7 |
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| Affiliation(s) | "¹Humanitas University, Developmental Neurobiology Lab, Pieve Emanuele, Italy, ²La Sapienza University, Rome, Italy, 3Department of Immunology and Inflammation, IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy, ⁴Neuropsichiatria infantile, Ospedale Salesi, Ospedali Riuniti di Ancona, Ancona, Italy, ⁵School of Medicine and Surgery, University of Milano-Bicocca, ⁶Institute of Molecular and Translational Cardiology (IMTC), IRCCS Policlinico San Donato, San Donato Milanese, Italy, ⁷Humanitas Clinical and Research Hospital, Rozzano, Italy, ⁸Fondazione Istituto Italiano di Tecnologia (IIT), Center for Life Nano-& Neuro-Science, Rome, Italy" |
