Effects of Phosphodiesterase Variants on Angiogenic Functions of Vascular Endothelial Cells
Loading...
Authors
Monteith, Katie
Date
Type
thesis
Language
eng
Keyword
angiogenesis , phosphodiesterase splice variant , cAMP , endothelial cells
Alternative Title
Abstract
Angiogenesis, the biological process of new vessel growth from already existing vasculature, occurs
physiologically and pathologically. Previous studies have linked insufficient angiogenic activity to
ischemic disease and excessive angiogenesis to cancer. These disease states have a massive global
burden. During angiogenic sprouting, a select few endothelial cells (ECs) develop a tip cell phenotype
and function to guide cell migration towards angiogenic factors to form the new growth. While
angiogenesis is a highly regulated process, the precise molecular mechanisms dictating individual EC
functions like migration are not fully identified. The cAMP second messenger is involved in regulating
EC angiogenic activity. Macromolecular complexes containing unique combinations of cAMP effectors
and individual phosphodiesterase isoforms, provide signal specificity by allowing control of local pools
of cAMP to mediate distinct functions. A PDE3B/ protein kinase A (PKA) signalling complex regulating
angiogenesis has previously been defined and more recently, it has been shown that impairment of
PDE4D signalling induces a hyper-migratory EC phenotype. The studies presented in this thesis
investigated the individual PDE4D splice variant responsible for regulating EC migration in telomerase-immortalized
ECs. We identified that PDE4D5, not pan-PDE4D or PDE4D7, silencing impedes EC
migration. We further identified unique sequences in the N-terminal region of PDE3B and PDE4D
isoforms that can be targeted using CRISPR-Cas9 to create stable variant selective knockout cell lines;
though due to time constraints, we opted to use other strategies to elucidate individual splice variant
function. We additionally found that the creation of a cell line stably expressing a dominant negative
PDE4D5 is possible, while PDE4D7 is not. Overall, this work supports the concept that individual PDE
isoforms regulate distinct functional pools of cAMP activity and indicates that translation would lead to
increased efficacy and decreased side effect profiles of therapeutics targeting dysregulated PDE
signalling.
Description
Citation
Publisher
License
Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.