Alzheimer's disease (AD) is an age progressive neurodegenerative brain disorder, affecting 37 million people worldwide. Cleavage of amyloid precursor protein by ?- and ?-secretase produces the amyloid-beta (A?) protein, which significantly contributes to AD pathogenesis. The A? aggregates, formed at the surface of neurons and intracellularly, cause neurotoxicity and decrease synaptic function. Inhibiting or degrading A? accumulation is a key goal for development of new AD treatments. Evidence shows that human Myelin Basic Protein (MBP) binds to and degrades A? thereby, preventing cytotoxicity. A potential method for oral drug delivery that will allow plant-derived bioencapsulated MBP to pass through intestinal epithelium and bypass denaturing stomach acidity is quite novel. Cholera Toxin B subunit (CTB), when fused with MBP, can serve as a vehicle for oral delivery of this chloroplast expressed therapeutic protein into the systemic circulation. Within chloroplast, CTB forms a pentameric structure that binds to GM1 ganglioside receptors, allowing receptor-mediated endocytosis. In order to investigate protein entry through neuronal GM1 receptors, we first created CTB fused to the green fluorescent protein (GFP). Incubation of this fusion protein with human neuroblastoma cells resulted in GFP entry into these cells whereas GFP alone was unable to enter. Similarly, co-incubation of CTB-MBP, via neuronal GM1 binding, allowed MBP to reduce neurotoxicity of A?42 treated cells by 37.1%. Delivery of CTB-MBP through GM1 receptor mediated binding should therefore facilitate oral administration, storage, heat stability and low cost AD treatment.
If this is your Honors thesis, and want to learn how to access it or for more information about readership statistics, contact us at STARS@ucf.edu
Bachelor of Science (B.S.)
Burnett School of Biomedical Sciences
Molecular Biology and Microbiology
Dissertations, Academic -- Medicine;Medicine -- Dissertations, Academic
Length of Campus-only Access
Honors in the Major Thesis
Ayache, Alexandra, "Amyloid-beta42 toxicity reduction in human neuroblastoma cells using cholera toxin b subunit-myelin basic protein expressed in chloroplasts" (2012). HIM 1990-2015. 1321.