Neurodevelopmental Mechanisms in Patient Induced Pluripotent Stem Cell - Derived Spheroids Modelling Dravet Syndrome
Abstract number :
1.073
Submission category :
1. Basic Mechanisms / 1E. Models
Year :
2024
Submission ID :
978
Source :
www.aesnet.org
Presentation date :
12/7/2024 12:00:00 AM
Published date :
Authors :
Cristiana Mattei, PhD – The Florey Institute of Neuroscience and Mental Health
Miaomiao Mao, PhD – The Florey Institute of Neuroscience and Mental Health
Sean Byars, PhD – Central Clinical School, Monash University
Erlina Mohamed Syazwan, BS – The Florey Institute of Neuroscience and Mental Health
Megan Oliva, PhD – The Florey Institute of Neuroscience and Mental Health
Timothy Karle, PhD – The Florey Institute of Neuroscience and Mental Health
Kay Richards, PhD – The Florey Institute of Neuroscience and Mental Health
Ingrid Scheffer, MBBS, PhD, FRACP, FRS – University of Melbourne, Austin Hospital and Royal Children's Hospital, Florey and Murdoch Children’s Research Institutes
Steven Petrou, PhD – Praxis Precision Medicines, Boston, MA, USA
Presenting Author: Snezana Maljevic, PhD – Florey Institute of Neuroscience and Mental Health, University of Melbourne, Australia
Rationale: SCN1A encodes Naᵥ1.1, a voltage-gated sodium channel predominantly expressed in GABAergic interneurons. SCN1A variants present the major cause of Dravet Syndrome (DS), a rare condition of developmental and epileptic encephalopathy (DEE). Among over 1000 DS mutations reported to date, almost all cause SCN1A loss-of function. A reduction in NaV1.1 function in inhibitory neurons is proposed to cause disinhibition, with the increased excitation of glutamatergic neurons resulting in seizures. The goal of this study was to establish a stem cell derived in vitro model of Dravet syndrome to elucidate disease mechanism in the context of brain development.
Methods: In this study we generated and assessed DS patient induced pluripotent stem cell (iPSC) – derived spheroids enriched with GABAergic neurons. The recruited patient carrying the SCN1A T1722N mutation presented with a severe and very defined DS clinical phenotype. To investigate developmental disruptions in DS pathophysiology, we profiled the transcriptome of patient-derived spheroids and subsequently tested the capability of this 3D in vitro model to reveal the cellular mechanisms of DS and predict drug response.
Results: We exploited the unique property of recently developed 3D inhibitory differentiation protocol in recapitulating crucial aspects of cortical development and used this technology to derive subpallium-like spheroids (SS) from DS patient iPSC and corrected control lines. The transcriptomic profile analysis of SSs revealed many differentially expressed genes, especially at the earliest timepoint, including a significant upregulation of several crucial factors regulating brain ventralization. In addition to revealing developmental disruptions, this 3D model showed the capability of recapitulating functional abnormalities of DS epilepsy with fewer GABAergic cells firing action potentials and receiving synaptic currents. The functional deficit in the patient-derived SSs could be rescued to some extent by acute application of fenfluramine as assessed by two-photon calcium imaging.
Conclusions: In summary, our patient iPSC-derived neuronal model of SCN1A DS revealed a profound dysregulation of developmental processes, which correlated with functional disruption in GABAergic neurons and predicted response to fenfluramine, a medication increasingly used for the treatment of DS.
Funding: The study received MDHS support grant to IS, SP and SM and MRFF Stem cell grant to SP and SM.
Basic Mechanisms