Year of Publication

2017

Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation

College

Arts and Sciences

Department

Chemistry

First Advisor

Dr. D. Allan Butterfield

Abstract

Expression proteomics is the field of science wherein proteins that make up the cellular proteome are identified both by name and by fold-change. Depending on the application of proteomics, this change in level could be due to internal cellular stressors or introduction of xenobiotics. Global oxidative stress measures use immunohistochemistry to determine the relative level of oxidative stress of macromolecules within the cell. In this dissertation, both global oxidative stress measures and expression proteomics were used in a variety of mammalian models in order to determine the effects of protein upregulation, intranasal insulin administration, and resveratrol supplementation on the cellular proteome and the resultant oxidative stress that occurs.

Pin1, a phosphorylation specific peptidyl-prolyl (cis/trans) isomerase that targets specific effector proteins, has been found to act upon a number of important proteins identified as contributing towards the progression and ultimate deterioration seen in AD. Pin1 was selected for viral upregulation in AD mouse models because of Pin1’s regulatory function in regards to tauhyperphosphorylation and amyloid-precursor protein (APP) processing, and the fact that it has been shown that Pin1 levels decrease and is oxidatively modified in brain as AD progresses. In this dissertation study, expression proteomics was employed after viral upregulation of Pin1 in AD mouse models in order to observe the changes in protein expression that follow. The findings of this dissertation study uncover a number of proteins with differential expression as a function of age following upregulation of Pin1 in an AD model providing evidence for the possibility of Pin1 being the target of future therapeutics to combat the progression of AD.

Insulin, while widely being known for its role in the control of blood glucose levels and cellular energetics, has recently become the focus of interest with regards to its effect on the brain in neurodegenerative disorders such as AD, though the downstream effects with respect to changes in the proteome and oxidative stress levels in AD mouse models remain to be clarified. This dissertation study focused upon the administration of insulin via the intranasal route using four mouse models including AD (APP/PS1), induced-diabetes (dbdb), and the AD/induced-diabetes cross (dbdbxAPP/PS1), and a wildtype control in order to study the effect of insulin on the brain of these disease state models with regards to oxidative stress and expression proteomics. The information garnered from this study suggest a possible beneficial effect, with regards to protein carbonyl levels, of intra-nasal insulin administration in the AD mouse models and the cross model, while yielding mixed results for most other models which may be due to low sample size and internal variability between animals. Through the use of expression proteomics and Two-way ANOVA, proteins from many different cellular processes were identified with differential expression. The results from these dissertation studies shed new light on the application of intra-nasal insulin to mitigate the effects of AD, a link that has been shown in recent years.

A diet high in saturated fats and simple sugars, also known as a western-diet, has been implicated in the progression of metabolic disorders, cardiovascular disorders, and most recently cognitive disorders. Resveratrol, an antioxidant that has gained notoriety in the past decade, has been shown to have beneficial effects with regards to some metabolic disorders, provided the subject had metabolic disorders to begin with. This dissertation study was focused around the supplementation of resveratrol into the diets of non-human primate rhesus monkeys when given a high-fat and sugar diet. The parietal lobule was selected for examination and expression proteomics employed in order to identify proteins representative of a wide range of cellular processes as having differential expression. These identified proteins represent possible routes of downstream action by resveratrol, as well as display protein level changes simply through the ingestion of high-fat and sugar diet alone.

Digital Object Identifier (DOI)

https://doi.org/10.13023/ETD.2017.052

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