Modeling G2019S-LRRK2 Sporadic Parkinson's Disease in 3D Midbrain Organoids

Summary: Recent advances in generating three-dimensional (3D) organoid systems from stem cells offer new possibilities for disease modeling and drug screening because organoids can recapitulate aspects of in vivo architecture and physiology. In this study, we generate isogenic 3D midbrain organoids with or without a Parkinson's disease-associated LRRK2 G2019S mutation to study the pathogenic mechanisms associated with LRRK2 mutation. We demonstrate that these organoids can recapitulate the 3D pathological hallmarks observed in patients with LRRK2-associated sporadic Parkinson's disease. Importantly, analysis of the protein-protein interaction network in mutant organoids revealed that TXNIP, a thiol-oxidoreductase, is functionally important in the development of LRRK2-associated Parkinson's disease in a 3D environment. These results provide proof of principle for the utility of 3D organoid-based modeling of sporadic Parkinson's disease in advancing therapeutic discovery. : H. Kim and colleagues generated 3D midbrain organoids containing a G2019S mutation in LRRK2 and used this system for sporadic Parkinson’s disease (PD) modeling in vitro. Their results demonstrate that these 3D midbrain organoids can recapitulate the pathological features of LRRK2-associated sporadic PD. These results demonstrate that the 3D midbrain organoids are invaluable for recapitulating PD phenotypes and understanding the molecular underpinnings of these phenotypes. Keywords: Parkinson's disease, iPSC, organoids, disease modeling, midbrai