Date of Award
College of Natural Science and Mathematics, Chemistry and Biochemistry
Michelle K. Knowles
Alzheimer's disease, Amyloids, Caenorhabditis elegans, Cancer, Neurodegenerative diseases, Parkinson's disease
The aberrant fibrous, extracellular, and intracellular proteinaceous deposits in cells, organs and tissues are referred to as amyloids. These deposits are dominated by β-sheet structures that have been implicated in several neurodegenerative diseases and cancer. In this work, the types of amyloidosis studied include Parkinson’s disease (PD) using UA196 and NL5901 strains of Caenorhabditis elegans (C. elegans), Alzheimer’s disease (AD) using GMC101 strain of C. elegans, and cancer-associated mutant p53 aggregation in MIA PaCa-2 mutant cells. Several molecules including SK-129, NS132, NS163, bexarotene, a polyphenol (-)-epi-gallocatechine gallate (EGCG), ADH40, RD148, and RD242 were screened in vitro and in vivo while studying the inhibition of the amyloid protein aggregation. Also, the prion-like spread of amyloid fibrils was studied (through secondary nucleation) in NL5901 strain of C. elegans using α-Synuclein (αS) preformed fibrils and in MIA-PaCa-2 cells using p53 preformed fibrils. Various techniques were used in this study including paralysis assay, Thioflavin T (ThT) assay, immunofluorescence (IF) assay, confocal imaging, Proteomics analysis, Western Blot (WB) analysis to study the locomotion of C. elegans, to determine the amyloid fibril content in vitro and in vivo, determine upregulated and downregulated proteins in cells, and identify target proteins through immunoblotting of cell lysates, respectively. Oligopyridylamides (OPs) and Oligoquinolines (OQs) displayed remarkable neuroprotective effects in DA neurons and rescued various PD phenotypes of C. elegans, including rescue of degeneration of DA neurons, improved motility rate, decreased reactive oxygen species, food-sensing behavioral deficits, and rescue of dopamine synthesis. Also, we demonstrated that OPs rescue PD phenotypes when administered to the post-disease-onset C. elegans model. The results from this study proposed that SK-129, NS132, NS163, bexarotene, EGCG, ADH40, RD148, and RD242 are potent antagonists for amyloid protein aggregation.
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Johnson Anazoba Joseph
Received from ProQuest
Joseph, Johnson Anazoba, "Inhibition of de novo and the Prion-Like Spread of Amyloidogenesis Using in vitro and in vivo Disease Models" (2022). Electronic Theses and Dissertations. 2120.
Biochemistry, Cellular biology