Reduction of cholesterol ester (CE) from lipid burden lesion-associated macrophage foam cells has been shown to reduce plaque volumes. Hydrolysis of CE to free cholesterol (FC) in macrophages is an essential step for removal of CE from the macrophage and its transport to the liver by high density lipoprotein (HDL) for further metabolism. Since CE must again be hydrolyzed into FC in the liver catalyzing this hydrolysis, it becomes imperative to find the identity of these enzymes. In this study the role of key enzyme in catalyzing the hydrolysis of CE to FC, neutral cholesterol ester hydrolase (CEH) was evaluated. Further, ability of this CEH to hydrolyze CE delivered via scavenger receptor BI (SR-BI) or SR-BII was also monitored. CE hydrolysis and FC efflux were monitored from cells transfected with CEH expression vector. No significant difference was noted in either the intracellular CEH activity or FC efflux between cells transfected with an empty vector or a CEH expression vector. Further no difference was seen when experiments were repeated with cells stably transfected with SR-BI or SR-BII. Future experiments with more optimization of the cells system used will be required to reach any conclusions on the role of CEH in hydrolyzing HDL-CE delivered via SR-BI/BII.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.