Defense Date

2019

Document Type

Thesis

Degree Name

Doctor of Philosophy

Department

Anatomy & Neurobiology

First Advisor

Andrew K. Ottens

Abstract

The development of traumatic brain injury (TBI) therapeutics and effective translation to clinic remains stubbornly elusive despite the high prevalence of TBI within the United States and across the globe. Interventions must be devised around testable targets, appropriately timed to intercede on secondary results. Here, we have utilized temporal neuroproteomics as an ideal approach to inform on the complex biochemical processing in order to address the well-recognized temporal evolution of TBI pathobiology and interrogate a novel therapeutic target in a mild-moderate rat Controlled Cortical Impact (CCI) within perilesioned somatosensory cortex. First, our findings revealed 2047 proteins significantly impacted within the first two weeks following TBI. Subsequent artificial neural network analysis revealed a delayed-onset cluster of proteins highly enriched in GABAergic neurotransmission and ion transport to reveal the prototypical target potassium/chloride transport 2 (KCC2 or SLC12A5) for further investigation with the KCC2-specific pharmacologic CLP290. Our tested therapeutic window guided by post-translational processing preceding one-day prior to protein loss revealed effective CLP290 restoration of KCC2 localization. We further demonstrated recovery in functional and behavioral assessments with one-day administration paradigm supporting the effectiveness of CLP290 treatment after brain injury. To better understand the underlying mechanism of CLP290, we utilized proteomic and bioinformatic approaches to tease out the biological response to treatment. Results demonstrate recovery of PKCδ-mediated phosphorylation of KCC2 and recovery of transporter activity. Additionally, findings reveal preservation of tyrosine kinase by reversing ubiquitin-mediated proteasomal degradation. Our functional assessment of secondary injury insults two-weeks following TBI revealed recovery in seizure threshold, reduction in lesion expansion and a decrease in cell loss suggesting maintained recovery of KCC2 and restored E/I balance. In conclusion, the presented studies in these two chapters propose a novel approach for development of therapeutics for TBI and test the selective manipulation via pharmacological intervention. These findings are promising for the development and treatment of other neurological disorders.

Rights

© Pavel Lizhnyak

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

5-3-2019

Available for download on Wednesday, May 01, 2024

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