Date of Graduation

2017

Document Type

Dissertation

Degree Type

PhD

College

Eberly College of Arts and Sciences

Department

Chemistry

Committee Chair

Stephen J Valentine

Committee Co-Chair

Suzanne Bell

Committee Member

Glen P Jackson

Committee Member

Carsten Milsmann

Committee Member

Timothy R Nurkiewicz

Abstract

Proteomic and metabolomic analyses provide information about altered metabolic processes in plants and animals. This information can be used to assess the impact of toxicant exposure or diseases on biological systems. In this dissertation, development of an ion mobility spectrometry - mass spectrometry (IMS-MS) strategy has been evaluated in addition to utilizing traditional liquid chromatography tandem mass spectrometry (LC-MS/MS) techniques for metabolite and protein analysis. Traditional LC-MS/MS techniques have been applied to the study of: 1) the molecular mechanisms responsible for altered microvasculature function as a result of pulmonary TiO2 exposure in rats; and 2) the effectiveness of intracerebroventricular (ICV) injection of streptozotocin (STZ) to mimic early metabolic changes found in tauopathies in mice exhibiting P301L or human wild-type tau.;Inhalation exposure to TiO2 nanoparticles (NPs) has been shown to produce a pulmonary inflammatory response, to induce oxidative and nitrosative biomarkers in the systemic microcirculation, and to influence downstream microvascular dysfunction. However, the molecular mechanisms relating pulmonary inflammation with the systemic microvascular dysfunction in addition to differences in responses of vascular tissues have yet to be fully elucidated. The first study examined plasma from rats exposed to TiO2 NPs. A total of 58 proteins were identified by at least 2 unique peptides and found in at least 3 samples, and 23 metabolites were identified through ChemSpider matches and filtered for endogenous compounds. The compounds were then analyzed by principal component analysis (PCA) and 29 proteins and 18 metabolites were found to contribute most to the separation in PC1. These proteins and metabolites were then input into Ingenuity Pathway Analysis (IPA). IPA revealed 13 canonical pathways as being significant (p ≤ 0.05) based on the input proteins, but none were found to be significantly up or down regulated (z ≥ |2|) based on fold differences of the input proteins.;The second study examining plasma, aorta, and small resistance vasculature tissue from rats exposed to TiO2 NPs was performed in order to gain further insight into the pathway activation mechanisms as well as to determine if responses differ based on tissue structural and functional differences. Congruent with the previous study, acute phase response signaling, LXR/RXR activation, and FXR/RXR activation emerge as being significant pathways (p ≤ 0.05) in the aorta and plasma; however, none were found to be significantly up or down regulated (z > |2|). ILK signaling, D-myo-inositol (1,3,4)-trisphosphate biosynthesis, and 1D-myo-inositol hexakisphosphate biosynthesis II (mammalian) pathways are observed to be significant (p ≤ 0.05) in the vasculature, but none were found to be significantly up or down regulated (z ≥ |2|).;P301L and human wild-type (WT) tau mice were administered an intracerebroventricular (ICV) injection of control vehicle buffer (Veh) or streptozotocin (STZ) to mimic early metabolic changes found in tauopathies, including Alzheimer's disease and frontotemporal dementia. Brain hemispheres were analyzed from 6 sample cohorts: Control (CT)-Veh, CT-STZ, P301L-Veh, P301L-STZ, WT-Veh, and WT-STZ. Bottom-up proteomic analyses were utilized to identify differentially abundant proteins within the brain proteome and the biopathways altered as a result of ICV-STZ treatment. An ANOVA was used to determine the top 50 significant proteins among the 6 sample cohorts. Biopathway analysis of the top 50 proteins revealed 49 biological pathways as being significant (p ≤ 0.05), but none were significantly up or down-regulated (z ≥ |2|) among the cohorts. 14-3-3 Mediated Signaling was found to be the most significant pathway among the cohorts. Protein Kinase A Signaling pathway was also found to be significant and had an associated z-score, although it was not found to be significantly up or down-regulated in any of the comparisons. Proteome and pathway changes were observed as a result of ICV-STZ administration; however, none were found to be significantly up or down-regulated. (Abstract shortened by ProQuest.).

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