Title

Development of a High-Throughput Assay for Alzheimer’s Disease Drug Identification

Date

12-8-2020 2:40 PM

Abstract

The Amyloid Cascade Hypothesis places the aggregation of the peptide Beta Amyloid (AB) as the root cause of the pathogenic cascade of Alzheimer’s Disease (AD). As such, it becomes important to identify species which may inhibit or reverse the aggregation of AB in the brain as these may lead to the discovery of a cure or treatment for AD. Here, we seek to identify small molecules which may inhibit or reverse AB aggregation via a novel, high throughput method and confirmed by two additional methods. Fluorescence Anisotropy (FLA) is the novel method used to rapidly analyze the aggregative state of Beta Amyloid (AB) via the attachment of the fluorophore, TAMRA to AB, and is then confirmed by Fluorescence Intensity (FLI) and Atomic Force Microscopy (AFM). Previously, we have been successful in using FLA, FLI, and AFM to demonstrate that metal chelators such as EDTA may reverse aggregation of AB where aggregation is due to metal-induced oligomerization. Here, we study the effects of small biomolecules trehalose (TREL), tramiprosate (TRAM), and curcumin (CURC) on the aggregative state of AB where oligomerization is self-induced. This will be assessed in two studies: induction and reversal. In the induction study, TREL showed the smallest increase in anisotropy as compared to self-aggregated AB at 24 h, followed by CURC and TRAM implying TREL is the most effective in preventing aggregation, and none are inducing aggregation. In the reversal study, TREL shows the least significant increase in anisotropy followed by CURC and TRAM, similar to the induction study. FLA results of the reversal study, however, may be invalid due to an unusual decrease in anisotropy of self-aggregated AB. Where FLI corroborates the induction study, AFM will be conducted in the future and FLA repeated in the reversal study to ensure accuracy of these results.

Biographies

Kim Paulin Major: Chemistry
Born in Ventura, CA and raised in Oxnard, CA, Paulin moved to the Portland area his senior year of high school. He graduated from Sam Barlow High School in 2017 and began at Portland State University the following fall studying chemistry. At the end of his first year, Paulin joined the Mackiewicz Laboratory of Nanostructured Materials in the Department of Chemistry and was also accepted into the BUILD EXITO program. Under the guidance of Dr. Marilyn R. Mackiewicz, he studied the effects of small molecules on beta amyloid aggregation which has since evolved into his McNair Research Project in his third year. Under the BUILD EXITO program, Paulin is also working on the design and synthesis of oxidation-resistant nickel nanoparticles. As a first-generation and independent student, Paulin is very proud of the progress he’s made in his academic career. As he begins the application process for doctoral programs in inorganic and materials chemistry, he looks to the future with excitement and determination to fulfill his life-long goal of completing a PhD.

Faculty Mentor: Dr. Marilyn R Mackiewicz
Dr. Marilyn Mackiewicz is an Assistant Professor with the Department of Chemistry. She earned her doctorate in Chemistry at Texas A&M University in 2005.The Mackiewicz lab consists of modern-day explorers of the molecular world and architects of nanoscale materials. Our research is focused the development of nanostructured materials for applications that relate to human health, the environment, and energy. Our major projects revolve around 1) the design of nanoscale materials for biomedical applications, 2) studying nanoparticle-biological interactions and nanotoxicology, 3) the development of diagnostic assays and imaging agents to monitor disease states and therapeutic response, and 4) systems for targeted drug delivery. Our long-term goal is to advance our bench side chemistry into translational applications in cancer, Alzheimer's disease, and macular degeneration. At the same time, it is important to study the nanotoxicological effects of the new materials developed and their nanoparticlebiological interactions that will advance their designs.

Disciplines

Chemistry

Persistent Identifier

https://archives.pdx.edu/ds/psu/33597

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Aug 12th, 2:40 PM

Development of a High-Throughput Assay for Alzheimer’s Disease Drug Identification

The Amyloid Cascade Hypothesis places the aggregation of the peptide Beta Amyloid (AB) as the root cause of the pathogenic cascade of Alzheimer’s Disease (AD). As such, it becomes important to identify species which may inhibit or reverse the aggregation of AB in the brain as these may lead to the discovery of a cure or treatment for AD. Here, we seek to identify small molecules which may inhibit or reverse AB aggregation via a novel, high throughput method and confirmed by two additional methods. Fluorescence Anisotropy (FLA) is the novel method used to rapidly analyze the aggregative state of Beta Amyloid (AB) via the attachment of the fluorophore, TAMRA to AB, and is then confirmed by Fluorescence Intensity (FLI) and Atomic Force Microscopy (AFM). Previously, we have been successful in using FLA, FLI, and AFM to demonstrate that metal chelators such as EDTA may reverse aggregation of AB where aggregation is due to metal-induced oligomerization. Here, we study the effects of small biomolecules trehalose (TREL), tramiprosate (TRAM), and curcumin (CURC) on the aggregative state of AB where oligomerization is self-induced. This will be assessed in two studies: induction and reversal. In the induction study, TREL showed the smallest increase in anisotropy as compared to self-aggregated AB at 24 h, followed by CURC and TRAM implying TREL is the most effective in preventing aggregation, and none are inducing aggregation. In the reversal study, TREL shows the least significant increase in anisotropy followed by CURC and TRAM, similar to the induction study. FLA results of the reversal study, however, may be invalid due to an unusual decrease in anisotropy of self-aggregated AB. Where FLI corroborates the induction study, AFM will be conducted in the future and FLA repeated in the reversal study to ensure accuracy of these results.