Theses and Dissertations at Montana State University (MSU)
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Item Development and analysis of lipidomics procedures for the causal investigation of Alzheimer's disease(Montana State University - Bozeman, College of Letters & Science, 2022) Koch, Max Richard; Chairperson, Graduate Committee: Edward Dratz; This is a manuscript style paper that includes co-authored chapters.Uncovering sets of molecular features which cause a healthy metabolic state to transition to one of disease, requires extensive experimentation and often presents a difficult analysis. In the case of neurodegenerative diseases, such as Alzheimer's Disease, simply obtaining suitable samples can be a challenging endeavor. Many current 'Omics' techniques excel at profiling a vast array of molecules, such as water-soluble metabolites, lipids, and proteins, in order to compare groups of samples from healthy and diseased organisms. Such approaches primarily use various associations between molecules and disease to identify biomarkers. However, these 'omics' experiments frequently result in intriguing biological hypotheses, but to date have rarely provided mechanistic explanations. How then, can mechanistic explanations be recovered from metabolite or lipid profile data? In our work, we applied these methods to 6 Alzheimer's diseased brain samples and 6 age matched controls. When analyzed via mass spectrometry, lipids which differed significantly between control and disease were identified, but this information was not able to'provide mechanistic insight. The beginning of any 'omics' based experiment starts with the extraction of the desired molecules. In order to assess the efficiency of three different lipid extraction methods, a lipid standard was extracted from a matrix composed of rat liver tissue and analyzed by mass spectrometry. The classic Folch extraction was found to be best at reproducibly extracting a wide range of lipids. Several of the lipids identified from human brains showed oxidative damage. Lastly, 5 statistical measures of dependence and 3 network algorithms were investigated for their ability to reconstruct mechanistic relationships in a dynamic model of arachidonic acid metabolism. Many of the metabolites of arachidonic acid are oxidation products. Under conditions of high noise and relatively few samples, standard measures of correlation, such as Pearson's correlation, Spearman's correlation and Kendall's Tau were found to perform the best. Metrics which incorporate nonlinear metabolic relations and network algorithms were found to be applicable, when sample size is large and the signal to noise ratio is close to l.Item Mass spectrometry based lipidomics as a tool in the search for biomarkers and mechanisms of disease(Montana State University - Bozeman, College of Letters & Science, 2016) Willems, Daniel Lee; Chairperson, Graduate Committee: Edward Dratz; Nicholas E. Goocey and Edward A. Dratz were co-authors of the article, 'A highly reproducible and efficient lipid extraction protocol enhanced using 3D printing of centrifuge adapters for optimum glass vials' submitted to the journal 'Lipids' which is contained within this thesis.; Max Koch, Nicholas E. Goocey, Blaine R. Roberts and Edward A. Dratz were co-authors of the article, 'Lipidomic analysis of human brain cortex in alzheimer's disease reveals aberrant levels of acetylcholine precursor speices' submitted to the journal 'American journal of alzheimer's disease and other dementias' which is contained within this thesis.; Max Koch, Nicholas E. Goocey, Blaine R. Roberts and Edward A. Dratz were co-authors of the article, 'Lipidomics reveals aberrent metabolism of lipid molecules in alzheimer's disease cerebral cortex' which is contained within this thesis.Lipidomics studies a highly diverse class of compounds insoluble in water and soluble in organic solvents. Lipids are a major component of cells and tissues, take part in a rich network of metabolic reactions, and are implicated in many disease mechanisms. Lipidomics complements genomics, proteomics and the more common metabolomic analysis of hydrophilic metabolites and can provide new insights into disease mechanisms. The problem approached in this thesis was to compare different methods of sample preparation for lipidomics and apply lipidomics to the study of two major health problems: Nonalcoholic Fatty Liver Disease (NAFLD) and Alzheimer's Disease (AD). Excessive dietary intake of sucrose and fructose, common in the Western Diet, increases deposition of triacylglycerides in the liver and leads to cognitive decline in experimental animals. NAFLD increases the risk of type 2 diabetes, obesity and AD. The high diversity and hydrophobicity of lipids complicates their separation, detection and analysis. However, modern chromatography and mass spectrometry instrumentation and techniques are greatly improving the capability of lipidomic analysis. A lipid extraction protocol was optimized for reproducibility and yield, and was used to extract lipids from rat liver under sucrose stress in a model of human NAFLD and human brain cortex from Alzheimer's Disease (AD) compared to controls. The samples were analyzed using mass spectrometry. The NALFD study did not yield the expected results, instead these data provided a foundation for designing future experiments in progress and to validate the methods used in the AD study. The AD studies showed that several phosphatidylcholine species are down regulated along with acetyl-CoA, which may be the source of low levels of the neurotransmitter acetylcholine in AD. Two different chromatography methods were used to seek a higher coverage of different lipids. Differences in the lipids in AD and controls were evident in the omega-6 and omega-3 fatty acids. The precursors of long omega-3s synthesis were increased while the products EPA and DHA were decreased. In a similar fashion, precursors to long omega-6s were found to be decreased, while the products were increased. This suggests that the omega-6 synthesis pathway may be outcompeting the omega-3 synthesis.Item Mouse and stem cell models of frontotemporal dementia(Montana State University - Bozeman, College of Letters & Science, 2012) Orr, Miranda Ethel; Chairperson, Graduate Committee: George A. Carlson; Frances Lefcort (co-chair)Alzheimer's disease (AD) is the most prevalent brain disease in the United States, and an escalating health concern. AD patient brains acquire hallmark protein aggregates, referred to as senile A beta plaques and neurofibrillary tangles (NFTs), that coincide with brain cell loss and dementia. A subset of AD patients carry mutant genes. Our understanding of AD largely relies on model systems that express these gene variants. Mice engineered to express AD-mutant human genes develop A beta plaques, but fail to develop the tau-containing NFTs or cell loss. Mutant tau variants are required to induce NFTs and neuronal loss in mice, but AD patients carry normal tau genes. The inability of mouse tau to become a pathogenic protein in the presence of AD-mutant gene variants, and the general insufficiency of the current systems to recapitulate AD, inspired the research described here. To determine if species differences between mouse and human tau inhibit the progression of AD in mice, I utilized a well-characterized mouse model of a related disease, frontotemporal dementia (FTD). FTD mice carry mutant human tau and develop NFTs and cell loss. I ablated mouse tau in FTD mice and looked for signs of more severe pathology. I compared the FTD mice, with and without mouse tau, to FTD mice with and without wild type human tau to investigate potential tau species-specific differences. My studies indicated that wild type tau, mouse or human, dampened the pathological effects of FTD tau implying a general, not mouse-specific, effect of normal tau protein. Our data suggest that unknown factors, distinct from endogenous mouse tau, contribute to the inability of mice to model AD. The recent interest in patient-specific stem cell (SC) models to study disease necessitates a thorough evaluation of their ability to recapitulate key characteristics of disease, reproducibility, and longevity. I generated and characterized brain SC cultures from FTD fetal mice and compared them to those generated from mice with normal human tau. Significant genotype associated differences were discovered in the SC system and later verified in adult mice to reinforce the potential of patient-specific SC models to study disease.Item Supporting caregivers through education on dementia(Montana State University - Bozeman, College of Nursing, 2011) Smith, Kammiell Marie; Chairperson, Graduate Committee: Elizabeth S. KinionDementia, a degenerative condition, is a progressive and debilitating disease evidenced by a decline in cognitive function affecting memory, communication, motor activity, and judgment. It is difficult for caregivers to cope with substantial changes in behavior, personality, and communication associated with this illness. Consequently, as the population ages the incidence of dementia will increase. It draws particular importance to the family caregiver role in maintaining the activities of daily care and managing unpredictable, progressive changes of the disease. Caregivers of persons with dementia take on a role that has considerable responsibility. Family caregivers also experience an added sense of duty that often leads to caregiver stress and burden. The purpose of this project was to develop an educational program. The program included a comprehensive literature review, input gathered from two assistive living homes and one senior center, and a one-hour educational presentation. The one hour educational presentation was presented at two assisted living homes and one senior center. Careful consideration was given to the aspects of stress and burden on family care givers of individuals with dementia. Psychosocial interventions, caregiver self-care, community resources, and interventions to assist with activities of daily living were also discussed. Content for the educational presentation addressed the following topics: signs and symptoms of dementia; interventions to assist with communication, behavioral and environmental management; and community resources to help with caregiver burden. Of the eight key lessons learned, two lessons are important to note. First, it is imperative to assess the emotional needs of the caregiver prior to the program development. Second, caregivers require an individualized approach to dealing with individuals with dementia. Important roles for Family Psychiatric Mental Health Nurse Practitioners (FPMHNP) are to provide anticipatory guidance to family caregivers about managing the changes in behavior, personality, and communication associated with dementia. They should also develop individualized, appropriately tailored, psychosocial interventions for the management of dementia. The FPMHNP is instrumental in assisting family caregivers with self-care management and providing information on community resources.