Comparing Teratogenic Risk of Anti-Seizure Medications in Single-Rosette Brain Organoids
Abstract number :
3.501
Submission category :
2. Translational Research / 2B. Devices, Technologies, Stem Cells
Year :
2023
Submission ID :
1488
Source :
www.aesnet.org
Presentation date :
12/4/2023 12:00:00 AM
Published date :
Authors :
Presenting Author: Andrew Tidball, PhD – University of Michigan Medical School
Joy Huang, Undergraduate – Neurology – University of Michigan Medical School; Roksolana Sudyk, Undergrad – Neurology – University of Michigan Medical School; Jinghui Luo, PhD – Neurology – University of Michigan Medical School; Taylor Takla, BSc – Neurology – University of Michigan Medical School; Jonathan Z. Sexton Sexton, PhD – Internal Medicine – University of Michigan Medical School; Jack Parent, MD – Neurology – University of Michigan Medical School
Rationale: Neural tube defects (NTDs), including anencephaly and spina bifida, are common major fetal malformations resulting from incomplete closure of the neural tube. These conditions lead to universal death or life-long severe complications. Many anti-seizure medications (ASMs) increase the risk of NTDs during pregnancy but are typically not discontinued because of danger to the mother and fetus from seizures. Therefore, it is important to compare the neuroteratogenic risk of these compounds to choose the most appropriate ASM during pregnancy.
Methods: Using our self-organizing single rosette cortical organoid (SOSR-CO) system, we have developed a high-throughput image analysis pipeline for evaluating SOSR-CO structure. During the neurulation-like phase, SOSR-COs generated from a ZO1-EGFP expressing induced pluripotent stem cell line were treated with test compounds for 48 hours followed by automated confocal microscopy. These images were processed in a custom CellProfiler pipeline to identify the metrics of each SOSR-CO (labeled with HCS CellMask) and the apical lumen (ZO1-EGFP). Over 400 features were measured, including intensity, fluorescence distribution, and morphometric/shape characteristics.
Results: Treatment of SOSR-COs with valproic acid (VPA), the most teratogenic ASM, resulted in increased lumen size that was linearly correlated over a large concentration range (100-1000 µM). This feature was the most instructive for predicting the VPA concentration. Additionally, VPA treatment resulted in enlarged apical surface areas, and, thus, impairment of apical constriction, a known NTD mechanism, is the likely cause of VPA-induced NTDs. Using the normalized lumen size as an NTD structural signature, we investigated the structural consequences of commonly used ASMs in SOSR-COs at seven concentrations covering 10-fold above and below the best estimate of typical patient peak serum concentrations. For each ASM we have six independent experimental replicates, with between 367-1360 individual SOSR-COs analyzed for each ASM. The results were evaluated to determine a concentration dependent risk for each. Currently, we see VPA-like signatures for known teratogens, topiramate and phenytoin, as well as the newer ASM, zonisamide. We see no NTD signature for cannabidiol, clonazepam, lamotrigine, levetiracetam, oxcarbazepine, or the inactive, unmetabolized form of carbamazepine. Currently, our data is inconclusive or intermediate for phenobarbital and lacosamide.
Conclusions: Our study shows the utility of screening pharmaceuticals in vitro for teratogenic risk. We see teratogenic signatures similar to VPA for known teratogens including topiramate and phenytoin, with some intriguing results for the newer ASM zonisamide. This makes sense given the structural similarities between topiramate and zonisamide. While our screen does not prove teratogenicity in a whole organism context, it does raise concern for the use of zonisamide during pregnancy that should be closely evaluated.
Funding: NIH/NICHD HD106580 (AT)
Translational Research