Abstract

Alzheimer’s disease (AD) and cerebral amyloid angiopathy (CAA) are neurodegenerative diseases that are pathologically defined by accumulations of amyloid beta (Aβ) in the brain parenchyma and vascular walls, respectively. CAA comorbidity occurs in more than half of advanced AD cases. Aβ can activate complement, an enzymatic cascade that terminates in a cytolytic pore called membrane attack complex (MAC). Protectin (CD59) is a GPI-anchored glycoprotein that physically interrupts formation of MAC. At autopsy, individuals with AD and CAA have high levels of MAC and normal to low levels of CD59 in the tunica media of affected blood vessels. We proposed the introduction of exogenous CD59 gene expression via a plasmid (pDNA) to rescue cerebrovascular smooth muscle cells (cvSMC) from lysis by MAC. Chitosan (Cs) is a linear glucosamine polysaccharide that is well described in a variety of nano- and micro-carrier payload delivery applications and frequently considered biologically inert. In this investigation we examined the stability of chitosan microparticles (CsM) under physiologic conditions and describe the response of primary human cvSMC to CsM and pDNA-loaded CsM (pCsM) as quantified by flow cytometry. We also explored the impact of chitosan polymers, the building blocks of CsM, on CD59 expression in cvSMC. We found that CsM are not stable under standard cell culture conditions while in cell culture media. CsM effectively delivered plasmid into cvSMC, as evidenced by high CD59 mRNA expression levels 24 h after transfection. However, this effect appeared to be lost in translation and no increase in CD59 surface expression was seen after treatment with pCsM. Surprisingly, Cs alone induced robust and persistent increases CD59 in cvSMC surface expression. These finds challenge assumption that Cs is inert and encourage the use of chitosan-only controls in future transfection experiments.

LLU Discipline

Microbiology and Molecular Genetics

Department

Microbiology

School

School of Medicine

First Advisor

Wolff Kirsch

Second Advisor

Penelope Duerksen-Hughes

Third Advisor

Samuel Hudson

Fourth Advisor

William Pearce

Fifth Advisor

Salvador Soriano

Degree Name

Doctor of Philosophy (PhD)

Degree Level

Ph.D.

Year Degree Awarded

2019

Date (Title Page)

9-2019

Language

English

Library of Congress/MESH Subject Headings

Neurodegenerative Diseases; Chitosan; CD59 Antigens; Complement Membrane Attack Complex

Type

Dissertation

Page Count

xiv, 114 p.

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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