Abstract

Neurodegenerative diseases, including tauopathies and amyotrophic lateral sclerosis (ALS), place a severe burden on patients and healthcare systems. The biological complexity and clinical heterogeneity of these conditions have historically slowed down the development of effective treatments. However, focusing on core pathogenic mechanisms like the toxic accumulation of misfolded proteins and progressive neuronal loss provides a clear path forward for designing targeted therapies. RNA-targeted therapeutics, particularly antisense oligonucleotides (ASOs), are powerful tools for modulating gene expression and studying complex disease networks in vivo. This thesis applies these emerging molecular tools to build new therapeutic frameworks for neurodegenerative diseases, targeting both primary genetic drivers and downstream protein clearance pathways. The central goal is to explore how ASOs can be used to correct pathogenic RNA splicing, map out proteasomal clearance mechanisms, and deeply profile structural biomarkers as the disease progresses. Chapter 2 investigates a strategy to correct pathogenic tau splicing in a newly characterized mouse model expressing the MAPT N279K variant. We administered a splice-switching ASO via continuous osmotic pump delivery for one month to facilitate exon 10 exclusion, which successfully reduced the accumulation of pathogenic 4R tau. This treatment halted further neurodegeneration, evidenced by preserved ventricular volume, and lowered p62 levels, pointing to a reduction in intracellular protein build-up. We also observed that this genetic correction rescued several physiological and behavioral deficits, improving nestlet building and normalizing sleep functions based on piezoelectric recordings. This work not only advances a specific targeted treatment but also proves that RNA-mediated splice modulation is a viable, disease-modifying approach for tauopathies. Chapter 3 details an in vivo approach to enhance the clearance of toxic tau species by modulating the ubiquitin-proteasome system. We used ASOs as precision tools to target specific deubiquitinating enzymes, focusing on USP11 and USP14 in the PS19 tauopathy mouse model. Our results show that the targeted reduction of USP11 and USP14 lowers total tau levels. This chapter validates the modulation of proteasomal clearance pathways as a realistic strategy for reducing toxic protein burden, while also demonstrating how ASOs can be used to uncover and validate new therapeutic targets. Chapter 4 shifts focus to the longitudinal characterization of neurofilament light chain (NfL) and uses ASOs for biomarker validation in the SOD1 G93A rat model of ALS. We profiled NfL levels in both serum and cerebrospinal fluid from the pre-onset stage through end-stage disease. The data confirm NfL is highly sensitive for tracking disease progression, especially when correlated with functional electromyography measurements like fibrillations and positive sharp waves that indicate active denervation. Interestingly, while NfL is a reliable marker of neuronal decline, applying a targeted ASO to knock down NfL did not change the overall survival. This indicates that NfL acts as a highly sensitive biological passenger that reflects structural damage rather than an active driver of ALS pathology. In summary, this dissertation highlights the versatility of RNA-targeting therapies as both direct clinical treatments and precision tools for basic biological research. By proving the efficacy of splice-switching ASOs, mapping out new clearance mechanisms, and defining the exact biological role of major structural biomarkers, this work provides a solid foundation for developing new therapeutic strategies against neurodegenerative disorders.

Committee Chair

Timothy Miller

Committee Members

Celeste Karch; Chris Weihl; David Holtzman; Joanna Jankowsky

Degree

Doctor of Philosophy (PhD)

Author's Department

Biology & Biomedical Sciences (Neurosciences)

Author's School

Graduate School of Arts and Sciences

Document Type

Dissertation

Date of Award

8-17-2026

Language

English (en)

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Available for download on Monday, August 14, 2028

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Neurosciences Commons

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