Author ORCID Identifier
Document Type
Dissertation
Date of Award
2025
Degree Name
Doctor of Philosophy (PhD)
Department
Basic Biomedical Science
First Advisor
Jill Weimer
Abstract
Neurons are highly compartmentalized, specialized cells that are foundational to brain function. Moreover, the neurons we have early in life are the same cells that we carry through our entire life. For these cells to stay healthy and functional over this long period, a process called autophagy is used to clear unwanted, toxic, or unneeded materials from the cell. Alterations in autophagy caused by genetic mutations can lead to the death of neurons and neurodegenerative disease. Here, we use CRISPR technology to genetically modify mouse models to generate a model of autophagy associated neurological disease and study the molecular function of neurons. We first established a CRISPR method that allows us to genetically modify neurons during early brain development. Using this method, we were able to label endogenously expressed proteins to determine their localization in the cell and isolate these proteins to understand their interactions with other proteins. Next, we used CRISPR editing to modify the autophagy gene WDR45 in mice to generate a model of Beta-propeller Protein Associated Neurodegeneration (BPAN). We show these mice have robust behavior phenotypes consistent with BPAN, presenting with developmental issues, motor decline, and learning and memory impairment. We further found that this mutation leads to profound effects on the neurons as they develop large, dysmorphic compartments, referred to as spheroids, in the distal portions of their axons. Spheroids form early in the development of the animals and affect numerous types of neurons throughout the brain. These phenotypes are accompanied by changes in expression of several genes involved in synaptic maintenance, vesicular function, ER-associated calcium maintenance, and iron regulation including ferroptosis. We found WDR45 mutant neurons have fewer autophagosomes and an accumulation of mitochondria in their projections as well as significant changes in the proteins residing in their synapses. Finally, we discovered WDR45 associated spheroids contain large accumulations of endoplasmic reticulum and structures for synaptic function. Together, this work establishes WDR45 as a critical regulator of axon homeostasis and provides a new method of leveraging CRISPR for exploring the molecular biology of neural cells.
Subject Categories
Neuroscience and Neurobiology
Keywords
autophagy BPAN CRISPR
Number of Pages
196
Publisher
University of South Dakota
Recommended Citation
Meyerink, Brandon Lee, "Leveraging CRISPR technology to model Beta-propeller Protein Associated Neurodegeneration and explore mechanisms of neurological dysfunction" (2025). Dissertations and Theses. 335.
https://red.library.usd.edu/diss-thesis/335