Background
Current organoid technologies are a promising advancement in drug development and disease modeling, designed to combat the increasingly high clinical drug failure rates despite rigorous conventional preclinical testing. Organoids have been considered as a gold standard for preclinical drug development: providing a model that has a human genomic background, mimics the 3D architecture and function of their respective organs, and is scalable for high-throughput use.1 Despite these benefits, organoids need improvement in certain areas before its widespread adoption in an industry context, such as standardization.2 Within this study, we use our organoid differentiation kit to develop cardiac and cerebral organoids and evaluate them as a neurological disease model and for drug toxicity screening.
Methods
Organoids were made from commercially purchased human iPSCs (Cat. No.: ACS-1007, ATCC) using either Cerebral and Cardiac organoid kit from ACROBiosystems (Cat. No. RIPO-BWM001K, RIPO-HWM002K) based on the protocol outlined in the data sheet. Briefly, harvested iPSCs were seeded onto a 96 well ultra-low attachment plate and EB formation was monitored. Cells were treated with the required media given in the kit to trigger organoid formation and cell differentiation. Organoids were used for assays on the indicated timepoints. For cell marker confirmation, organoids were fixed, permeabilized and immunolabeled with the indicated cell markers. For the Parkinson’s disease model cerebral organoids on day 92 were treated with 0.1 µM and 1 µM alpha-synuclein pre-formed fibrils (Cat. No. ALN-H5115) for 12 days. For the cardiac toxicity model, cardiac organoids at day 25 were treated with different hERG inhibitor.
Results
Both cerebral and cardiac organoids mimicked the expected cellular and physiological response. Cerebral organoids, after exposure to Tau pre-formed fibrils to mimic the toxic ‘Tau seeds’, showed an increase in the aggregation of Tau along with the degeneration of dopaminergic neurons while disrupting the dendrites of other neurons in a concentration dependent manner. Cardiac organoids exposed to a potassium channel inhibitor also showed a delayed signal propagation resulting in the prolongation of the QT interval in comparison to its normal ‘beats’.
Conclusions
Organoids are a promising preclinical model for disease modeling and toxicity screening. By replicating the physiological functions of organs in an ex vivo environment, mimicking neurological disease pathogenesis with the addition of pre-formed fibrils or screening drug effects can be performed. Furthermore, various testing methods can be used to observe organ function such as electrical signal propagation.
References
Zhao Zixuan, et al. ‘Organoids.’ Nature Reviews Methods Primers 2022;2(1):94.
Kim Jihoon, Bon-Kyoung Koo, Juergen A Knoblich. ‘Human organoids: model systems for human biology and medicine.’Nature Reviews Molecular Cell Biology 2020;21(10):571–584.