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ERIC Number: ED552330
Record Type: Non-Journal
Publication Date: 2012
Pages: 149
Abstractor: As Provided
Reference Count: N/A
ISBN: 978-1-2679-4117-6
(1) The Relationship of Protein Expression and Cell Division, (2) 3D Imaging of Cells Using Digital Holography, and (3) General Chemistry Enrollment at University of Michigan
Matz, Rebecca L.
ProQuest LLC, Ph.D. Dissertation, University of Michigan
Chapter 1: The role of cell division in protein expression is important to understand in order to guide the development of better nonviral gene delivery materials that can transport DNA to the nucleus with high efficiency for a variety of cell types, particularly when nondividing cells are targets of gene therapy. We evaluated the relationship between cell division and protein expression when using commercial poly(ethylenimine) (PEI)-based polyplexes. The membrane dye PKH26 was used to assess cell division, and cyan fluorescent protein (CFP) was used to monitor protein expression. When analyzed at the whole population level, a greater number of cells divided than expressed protein, regardless of the level of protein expression observed, giving apparent consistency with the hypothesis that protein expression requires cells to pass through mitosis in order for the transgene to overcome the nuclear membrane. However, when the polyplex-exposed population was evaluated for the amount of division in the protein-expressing subpopulation, it was observed that substantial amounts of expression had occurred in the absence of division. Indeed, in HeLa S3 cells, this represented the majority of expressing cells. Of interest, the doubling time for both cell lines was slowed by ~2-fold upon exposure to polyplexes. This change was not altered by the origin of the plasmid DNA (pDNA) transgene promoter (viral vs nonviral). Gene expression arrays in polyplex-exposed HeLa S3 cells showed upregulation of cell cycle arrest genes and downregulation of genes related to mitosis. Chemokine, interleukin, and toll-like receptor genes were also upregulated, suggesting activation of proinflammatory pathways. In summary, we find evidence that a cell division-independent expression pathway exists, and that polyplex exposure slows cell division and increases inflammatory response. Chapter 2: Cell volume changes play important roles in processes associated with normal cell activities as well as disease states. Consequently, there is considerable need to accurately measure volumes of individual cells and cell populations over time. In this study, we monitored cell volume changes in real time during apoptosis using digital holographic microscopy (DHM). The results showed that after exposure to 1 mM staurosporine for four hours, the volumes of KB cells were reduced by ~50-60%, which is consistent with previous results obtained using electronic cell sizing and atomic force microscopy. In comparison with other techniques, DHM is advantageous because it employs noninvasive detection, has high time resolution and real time measurement capability, and can simultaneously probe the time-dependent volume changes of individual cells and cell populations. Chapter 3: At the collegiate level, science laboratories and their corresponding lectures are often offered as separate courses, and students may not be required to concurrently enroll in both. We examined the impact of concurrent versus nonconcurrent enrollment on 9,438 students¡¦ withdrawal rates from and final grades in the general chemistry lecture at the University of Michigan at Ann Arbor using multiple linear and binary logistic regression analyses, respectively, at a significance level of 0.05. We found that concurrent enrollment in the lecture and laboratory positively impacts (1) the odds of retention in the lecture by a factor of 2.2 times on average and (2) the final grades in the lecture course by up to 0.19 grade points on a 4.0 scale for the students that scored the lowest on university-level mathematics and chemistry placement exams. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page:]
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Publication Type: Dissertations/Theses - Doctoral Dissertations
Education Level: Higher Education; Postsecondary Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Identifiers - Location: Michigan