Abstracts

Development of Personalized “Disease-in-a-Dish” Model of Focal Cortical Dysplasia Using Induced Pluripotent Stem Cells

Abstract number : V.011
Submission category : 2. Translational Research / 2B. Devices, Technologies, Stem Cells
Year : 2021
Submission ID : 1826322
Source : www.aesnet.org
Presentation date : 12/9/2021 12:00:00 PM
Published date : Nov 22, 2021, 06:53 AM

Authors :
Muhammad Javaid, PhD - Monash University; Ben Rollo - Monash University; Alison Anderson - Monash University; Terence J.O'Brien - Monash University; Patrick Kwan - Monash University; Ana Antonic-Baker - Monash University

Rationale: Focal cortical dysplasia (FCD) is a type of malformation of the cerebral cortex and abnormal cytoarchitecture linked to disruption in the mTOR pathway, and is among the most common pathologies causing drug-resistant epilepsy. A range of somatic and germline mutations in mTOR pathway genes have been associated with FCD. Almost 30%-50% of all refractory epileptic patients admitted to surgery are FCD patients. Complex epilepsy aetiology and pathogenesis make it difficult for the surgery to be used alone to achieve seizure freedom. Conventional animal-based models are challenging to recapitulate the complex pathophysiological mechanisms of FCD. Improved disease models are needed for effective drug development. Human-based epilepsy models are desirable to mimic the pathophysiology of epilepsy. We developed a “personalised” human-based model using induced pluripotent stem cells (iPSCs) obtained from an individual patient with FCD.

Methods: Patient with a loss-of-function mutation in the mTOR pathway gene, DEPDC5, identified through whole-genome sequencing. Peripheral blood mononuclear cells were prepared from the patient to generate iPSCs. Using these iPSCs, monolayer neurons and 3D brain organoids were generated. Their morphology, neuronal gene expression, electrical activity, and mTOR activation was studied using immunocytochemistry, qPCR, flow cytometry, and microelectrode array (MEA) analysis.

Results: Monolayer neurons derived from the patient’s iPSCs expressed cortical and general neuronal markers. Patient derived neurons showed an increase in the phosphorylation and proliferation rate. This indicates the hyperactivation of mTOR pathway due to loss-of-function mutation in the DEPDC5 gene. Action potential based neuronal activity measured by MEA showed higher spike frequency in monolayer neurons derived from patients compared to control neurons.

Conclusions: We have developed “disease-in-a-dish” model from a patient with FCD. This model may provide novel insight into pathophysiological mechanisms that underpin FCD-related drug-resistant epilepsy involving the mTOR pathway, and could be used as a “personalised” drug screening platform in individual patients with FCD.

Funding: Please list any funding that was received in support of this abstract.: N/A.

Translational Research