Date Available

11-26-2021

Year of Publication

2015

Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation

College

Medicine

Department/School/Program

Anatomy and Neurobiology

First Advisor

Dr. Luke H. Bradley

Abstract

A major challenge in developing disease altering therapeutics for the treatment of Parkinson’s disease (PD) has been the delivery of compounds across the blood-brain barrier (BBB) to the central nervous system (CNS). While direct surgical infusion has been utilized to deliver compounds to the brain that don’t cross the BBB, issues of poor biodistribution in the CNS due in part to properties of the molecules being delivered and/or infusion device protocols have limited the widespread success of this invasive approach. To avoid the issues of surgically delivering compounds to the CNS, numerous studies have examined the use of intranasal administration as a non-invasive delivery method. The data presented in this dissertation examines intranasal administration of dopamine neuron stimulating peptide-11 (DNSP-11), a small, amidated peptide with neuroprotective and restorative properties, and its effects on the nigrostriatal system in animal models of PD.

Here we demonstrate that severely lesioned 6-hydroxydopamine (6-OHDA) F344 rats repeatedly administered DNSP-11 intranasally exhibited a decrease in damphetamine- induced rotation, dopamine (DA) turnover, and an increase in tyrosine hydroxylase positive neuronal sparing. Additionally, tracer studies indicated rapid distributed throughout the CNS and CSF following a one-time bilateral intranasal dose of 125I-labeled DNSP-11. These results demonstrate that DNSP-11 can be delivered to the CNS intranasally, and maintains its neuroactive properties on the nigrostriatal system in a rat model of PD.

In a dose escalation study of DNSP-11, we evaluated the efficacy of repeated intranasal administration in awake, vertically chaired trained, 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine (MPTP) hemiparkinsonian rhesus macaques using an atomizer system over a 10-week period. Here we report that animals did not exhibit observable adverse effects at the DNSP-11 concentrations examined, bilateral increases in fine motor performance of the upper limbs, and changes in tissue levels of DA and its metabolites. Finally, tracer studies indicated signal present throughout the CNS and CSF following a one-time bilateral intranasal dose of 125I-labeled DNSP-11. These studies support the efficacy of the repeated intranasal administration of DNSP-11 in awake Rhesus macaques over 10-weeks, while also enhancing motor performance and striatal neurochemistry in a non-human primate model of PD.

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