| dc.description.abstract | N-acyl-phosphatidylethanolamine-hydrolyzing phospholipase D (NAPE-PLD) is a zinc metallohydrolase that hydrolyzes N-acyl-phosphatidylethanolamines (NAPEs) to form N-acyl-ethanolamides (NAEs) and phosphatidic acid. Several lines of evidence suggest that reduced NAPE-PLD activity could contribute to cardiometabolic diseases, notably atherosclerosis. For instance, NAPEPLD expression is reduced in human coronary arteries with unstable atherosclerotic lesions, defective efferocytosis is implicated in the enlargement of necrotic cores of these lesions, and NAPE-PLD products such as palmitoylethanolamide and oleoylethanolamide have been shown to enhance efferocytosis. Thus, we predicted that modulating NAPE-PLD activity could be an effective means of both studying and treating atherosclerosis, particularly due to the enzyme’s role in regulating efferocytosis. However, no NAPE-PLD activators and only three potent NAPE-PLD inhibitors existed. Therefore, the primary goal of my project was to discover novel modulators of NAPE-PLD that could be used as research tools to determine the effect of NAPE-PLD modulation on efferocytosis, and which could be developed into therapeutics. We hypothesized that inhibiting NAPE-PLD activity or expression would decrease efferocytosis, and that activating NAPE-PLD would increase efferocytosis. Due to the potential health benefits of NAPE-PLD activators and the fact that any NAPE-PLD activator would be the first of its kind, we focused our efforts more heavily on activators. This primary goal was accomplished in four steps. The first was identifying potential novel NAPE-PLD modulators by high-throughput screening. The second was validating and characterizing the activities of those modulators. The third was developing a selective NAPE-PLD activity assay that worked in live cells. The fourth was demonstrating the modulators’ ability to modulate NAPE-PLD activity in living cells safely and effectively, so that they could be used to test the hypothesis that NAPE-PLD activity regulates efferocytosis. This project yielded a novel PLD-selective activity assay, a selection of first-in-class NAPE-PLD activators, and demonstrated that NAPE-PLD activation enhances macrophage efferocytosis capacity. | |
