Date of Award
Spring 2023
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Neuroscience
First Advisor
Park, In-Hyun
Abstract
Human cerebral organoids are three-dimensional cultures of brain-like tissue that model early human fetal cortical development. They recapitulate important neurodevelopmental events, including neural progenitor cell expansion, formation of a well-defined outer radial glia layer resembling the human outer subventricular zone, neurogenesis, and neuronal migration. In this study, I utilize cerebral organoids generated from induced pluripotent stem cells as a human-specific platform to investigate the mechanisms underlying neurodevelopmental and infectious central nervous system disease. The immediate application for cerebral organoids is to address the global healthpandemic of COVID-19 and its associated neurological manifestations. I demonstrate that exposure of cerebral organoids to SARS-CoV-2 leads to direct and widespread infection of cortical neurons and metabolic changes in infected as well as neighboring neurons. Neuronal infection can be prevented by blocking ACE2, the entry receptor for SARS-CoV-2, with antibodies or by administering cerebrospinal fluid from a COVID-19 patient. Finally, in autopsies from patients who died of COVID-19, SARS-CoV-2 can be detected in cortical neurons with accompanying pathological features associated with infection. These results provide evidence for the neuroinvasive capacity of SARS-CoV-2. Another important application of cerebral organoids is to study early human cortical development and its associated diseases. I utilize control, patient, and CRISPR-edited cerebral organoids to investigate the pathogenesis of pachygyria-lissencephaly caused by recessive stop-gain mutations in P53-Induced Death Domain Protein 1 (PIDD1). By performing phenotypic analyses of PIDD1 mutant organoids, I demonstrate neural progenitor and neuronal defects, including a thickened cortical plate-like structure reminiscent of pachygyria found in lissencephaly patients. Using single-cell RNA-sequencing and mass spectrometry, I demonstrate the hypoactivity of the AKT-mTOR signaling pathway in organoids harboring the PIDD1 mutation. These results shed light on the unknown role of PIDD1 in human cortical development and establish a previously unassociated pathway affecting neural development in the pathogenesis of lissencephaly. My dissertation work demonstrates the utility of cerebral organoid models to elucidate the underlying cellular and molecular mechanisms and inform potential therapeutic strategies for neurodevelopmental and infectious diseases.
Recommended Citation
Zhang, Ce, "Human Cerebral Organoids for Modeling Neurodevelopmental and Infectious Disease" (2023). Yale Graduate School of Arts and Sciences Dissertations. 1024.
https://elischolar.library.yale.edu/gsas_dissertations/1024
