Alzheimer’s Disease (AD) is a chronic progressive neurological condition, clinically characterized by memory deficits, cognitive and physical impairment, and personality changes. Traditionally, AD was considered a type of protein folding disorder. Here, the concept of AD as an autoimmune disease of the innate immune system was developed. After exploring evolutionary connections between the AD peptide β-amyloid (Aβ) and known antimicrobial peptides (AMPs), and elucidating the structural similarities between Aβ and AMPs, a mechanism of action for Aβ’s antimicrobial activity is proposed that is based on the compromise of bacterial membranes. Following these theoretical considerations, experimental evidence is presented for the production of Aβ by cells in response to infection, and for Aβ’s antibacterial and antiviral activity. Rooted in similarities of the cell membranes of neuronal and bacterial cells in terms of lipid composition and transmembrane potential, it is hypothesised that Aβ’s neurotoxicity is caused by its misguided attack on neurons as an AMP. In reversing the concept of Aβ as an AMP, the similarity of AMPs to Aβ is demonstrated in experiments revealing the neurotoxicity of two AMPs, LL 37, and cecropin A. To determine a mechanism for the progressive nature of AD, it was shown that, although apoptosis may be involved in AD, it is actually necrosis that is responsible for the propagation of neuronal cell death so characteristic of AD. With the Vicious Cycle of AD, a scheme was devised, integrating the results obtained here with data and research from other groups, which explains the chronic and progressive nature of AD as a result of Aβ’s physiological role as an AMP and innate immune system effector. Borne from Aβ’s activity as an AMP and its central role in the Vicious Cycle of AD, a question was investigated: do antibiotics, such as penicillin, that cause release of bacterial endotoxins due to their mechanism of action, trigger the Vicious Cycle of AD and thus lead to the development of AD? Preliminary evidence supporting this notion was presented.

The purpose of this descriptive study was to document and analyze the perceptions of family caregivers of non-institutionalized Alzheimer's patients about the benefits and limitations of Alzheimer's support groups. Survey methodology was used to survey caregivers and support group leaders from eight Alzheimer's support groups in the central Indiana area. Several of the major findings challenge the literature. These findings are as follows: The majority of caregivers attended the support group to receive information. None of the caregivers attended the support group due to frustration, and only one caregiver responded that relieving frustration was a benefit of participating in the support group. A majority of caregivers and support group leaders were positive about mixed (spouses and adult children) support groups. A majority of caregivers responded that they did not have guilt, anger, fears about caregiving in the future, or stress concerning their caregiving responsibilities. The study generated several implications that can be used by planners to improve support groups. / Department of Educational Leadership

Alzheimer's disease (AD) is characterised by a series of biomolecular aggregation events, which include the formation of neurotoxic protein structures composed of the β-amyloid (Aβ) peptide. In this thesis, fluorescence self-quenching (FSQ) between fluorescently-labelled peptides is introduced as a strategy for detecting and characterizing Aβ aggregates in solution, and for overcoming limitations associated with conventional methods. Using a combination of steady-state, picosecond time-resolved fluorescence and transmission electron microscopy, the fluorescence response of HiLyte Fluor 555-labelled Aβ peptides is characterised to demonstrate that Aβ self-assembly organizes the covalently attached probes in close proximity to trigger the self-quenching sensing process over a broad range of conditions. Importantly, N-terminal tagging of β-amyloid peptides is shown to not alter the self-assembly kinetics or the resulting aggregated structures. When performed in Förster resonance energy transfer (FRET) format, this method becomes a ratiometric platform to gain insights into amyloid structure and for standardizing in vitro studies of amyloid self-assembly. The ability of FSQ-based methods to monitor the inhibition of Aβ aggregation by model test compounds including the small heat shock protein (Hsp), the amyloid-binding alcohol dehydrogenase protein (ABAD) and bovine serum albumin (BSA) is also demonstrated. Given that Aβ is formed within the cell membrane and is known to induce its disruption, sophisticated single-molecule fluorescence spectroscopy methods were developed to quantify membrane dynamics induced by the presence of disrupting agents, such as Aβ and detergents. The solubilisation dynamics of single liposomes induced by the non-ionic surfactant Triton-X 100 (TX-100) were studied in real-time. Using this approach, the swelling and permeabilization steps of the solubilisation process were unambiguously separated within single FRET trajectories, and their kinetic details as a function of Triton-X 100 and presence of cholesterol within the membrane structure were examined. Finally, single-molecule stepwise-photobleaching techniques were employed to study the effect of Aβ oligomers interacting with supported-lipid bilayers, establishing a platform from which to investigate how the presence of a membrane layer affects Aβ oligomerization at the level of individual molecules. Overall, the fluorescence-based strategies for amyloid- and liposome-sensing presented in this work bridges the gap between current morphology-specific techniques and highly-specialized single-molecule methods to provide a biophysical toolbox to investigate the changes in structure, size and molecular interactions accompanying the amyloid aggregation pathway and for the screening of novel therapeutic and diagnostic agents.

The experiment tested the hypothesis that 192 IgG-saporin lesions of the nucleus basalis magnocellularis (NBM) in rats would impair performance in a biconditional visual discrimination task, which requires configural association learning. Experiment used 22 male Long-Evan rats (Harlan Sprague-Dawley). Behavioral testing was conducted in two identical T-mazes. Rats were randomly assigned to either a bilateral 192 IgG-saporin lesion group (n = 10) or to a control group (n = 12). Results support the hypothesis that NBM is critically involved in configural but not simple association learning and suggest that NBM may be involved more generally in cognitive flexibility.

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Master of Science / Biochemistry and Molecular Biophysics / Jianhan Chen / Proteins are fundamental building blocks of life in an organism, and to function properly, they must adopt an appropriate three-dimensional conformation or conformational ensemble. In protein aggregation diseases, proteins misfold to incorrect structures that allow them to join together and form aggregates. A wide variety of proteins are involved in these aggregation diseases and there are multiple theories of their disease mechanism. However, a common theme is that they aggregate into filamentous structures. Therapies that target the process by which the aggregating proteins assemble into these similar fibril-like structures may by effective at countering aggregation diseases. This requires models that can accurately describe the assembly process of the fibrils. An analytical theory was recently described where fibrils grow by the templating of peptides onto an existing amyloid core and the kinetics of the templating process is modeled as a random walk in the backbone hydrogen bonding space. In this thesis, I present my work integrating molecular simulation with this analytical model to investigate the dependence of fibril growth kinetics on peptide sequence and other molecular details. Using the Aβ16-22 peptide as a model system, we first calculate the rate matrix of transitions among all possible hydrogen bonding microscopic states using numerous short-time simulations. These rates were then used to construct a kinetic Monte Carlo model for simulations of long-timescale fibril growth. The results demonstrate the feasibility of using such a theory/simulation framework for bridging the significant gap between fibril growth and simulation timescales. At the same time, the study also reveals some limits of describing the fibril growth as a templating process in the backbone hydrogen bonding space alone. In particular, we found that dynamics in nonspecifically bound states must also be considered. Possible solutions to this deficiency are discussed at the end.

Mammalian brain is challenging to study due to its heterogeneity and complexity. However, recent advances in molecular imaging, genomics and proteomics have contributed significantly to achieve insights into molecular basis of brain function and pathogenesis of neurological disorders. Efficient sample preparation is an integral part of a successful mass spectrometry (MS)-based proteomics. Apart from the identification, quantification of proteins is needed to investigate the alterations between proteome profiles from different sample sets. Therefore, this thesis investigates optimizing and application of the MS compatible sample preparation techniques for the identification and quantification of proteins from brain tissue. The central objective of this thesis was (i) to improve the extraction of proteins as well as membrane proteins (MPs) from the brain tissue and (ii) to apply the optimized method along with the stable isotope dimethyl labeling (DML) and label-free (LF) MS approaches for the relative quantification of the brain proteome profiles during neurological conditions such as Alzheimer’s disease (AD) and traumatic brain injury (TBI).  First study described in this thesis is focused on the qualitative aspects for the brain tissue sample preparation. The optimized extraction buffers from first study containing n-octyl-β-glucopyranside or triton X-114 were used in the further quantitative studies to extract the proteins from patient (AD or TBI) and control human brain samples. Triton X-114 has additional advantage of separating MPs into a micellar phase. Therefore we also investigated the possibility to apply this in combination with DML quantitation approach for enrichment of low abundant MPs from AD brains. AD and TBI causes severe socio-economic burden on the society and therefore there is a need to develop diagnostic markers to detect the early changes in the pathology of the disease. Analytical tools and techniques applied and discussed in this thesis for neuroproteomics applications proved to be powerful and reliable for analyzing complex biological samples to generate high-throughput screening and unbiased identification and quantitation of disease-specific proteins that are of great importance in understanding the disease pathology.

Bakgrund: Alzheimers sjukdom (AD) är den vanligaste formen av demenssjukdomar och antalet människor som insjuknar i AD förväntas öka kraftigt med tiden. Dessutom kännetecknas personer med AD ofta av beteendemässiga och psykiska symtom (BPSD) som kan innefatta agitation, depression, vanföreställningar, oro, ångest, hallucinationer, sömnrubbningar, rastlöshet och apati. Dessa symtom kan orsaka lidande hos patienten och är svåra att hantera för både vårdgivaren och anhöriga, samt försvårar omvårdnadsarbetet. Syftet var att beskriva icke-farmakologiska metoder och effekter av dessa metoder vid omvårdnad av personer med Alzheimers sjukdom som har beteendemässiga och psykiska symtom. Metod: En litteraturöversikt bestående av 16 utvalda kvantitativa forskningsartiklar har genomförts. Artiklarna publicerades mellan år 2006-2016. Resultat. De studerade icke-farmakologiska metoderna var musikterapi, vissa typer av massage, reminiscence-terapi, vårdhundterapi och ljusterapi. Resultaten visade att icke-farmakologiska metoder kan ha en varierande effekt på BPSD. Litteraturöversikten visade att musikintervention var mest effektiv för att minska agitationsbeteende. Individualiserad musik i samband med speciella minnen minskade stress, fobier hos personer med svår demens. Intervention av handmassage, aromaterapi, taktil massage och terapeutisk beröring minskade aggression och agitationsbeteende. Vissa studier visade dock att fotmassageintervention och vårdhundterapi kunde öka verbal aggressivitet hos personer med demens, medan en annan studie visade att djurassisterade aktiviteter kunde minska nedstämdhet medan glädje och generell uppmärksamhet ökade. Effekten av ljusbehandling var förbättrad sömn, minskad depression, agitation och ätstörningar. Slutsats. Icke-farmakologiska metoder kan minska beteendemässiga och psykiska symtom hos personer med Alzheimers sjukdom, dock med varierande effekt. De varierande resultaten kan tolkas som att icke-farmakologiska metoder bör individanpassas och att det behövs vidare forskning inom området. / Background: Alzheimer's disease (AD) is the most common of dementia and the number of people diagnosed with AD is expected to rise significantly over time. In addition, people diagnosed with AD often exhibit the Behavioural and Psychological Symptoms of Dementia (BPSD), which include agitation, depression, delusions, agitation, anxiety, hallucinations, sleep disturbances, anxiety and apathy. These symptoms can cause suffer to the patient and is difficult to manage for both the caregiver and family members, as well as hampers nursing. Aim: the aim was to describe non-pharmacological methods and effects of these methods when caring for people with Alzheimer's disease who have behavioural and psychological symptoms. Method: a literature review consisting of 16 selected quantitative research articles has been performed. The selected articles ware published between years 2006- 2016. Results: The studied non-pharmacological methods were: music therapy, certain types of massage, reminiscence therapy, dog therapy and light therapy. The results showed that non-pharmacological methods can have a varying effect on BPSD. The literature review showed that music intervention was most effective in reducing agitated behaviour. Individualized music in conjunction with special memories reduced stress, phobias for persons with severe dementia. The hand massage, aroma therapy, tactile massage and therapeutic touch decreased aggression and agitated behaviour. Some studies showed that foot massage intervention and dog therapy could increase the verbal aggression for people with dementia, while another study showed that animal-assisted activities could reduce depression and increase joy and general attention. The effect of light therapy was an improved sleep, decreased depression, agitation, and eating disorders. Conclusions: non-pharmacological nursing interventions can reduce behavioural and psychological symptoms for people with Alzheimer's disease, however, with varying effect. The varying results can be interpreted as following: nonpharmacological nursing interventions should be adapted in each individual case and that there is a need for further research in this area.

published_or_final_version / Physiology / Doctoral / Doctor of Philosophy