Identification of a novel intracellular cholesteryl ester hydrolase (carboxylesterase 3) in human macrophages: compensatory increase in its expression after carboxylesterase 1 silencing
| Autor: | Shobha Ghosh, Jinghua Bie, Jing Wang, Stephanie A. Marqueen, Bin Zhao |
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| Rok vydání: | 2012 |
| Předmět: |
Physiology
Carboxylesterase 1 Molecular Sequence Data Biology Real-Time Polymerase Chain Reaction Gene Expression Regulation Enzymologic Monocytes Carboxylesterase Cell Line Small hairpin RNA chemistry.chemical_compound Chlorocebus aethiops Hydrolase Animals Humans Amino Acid Sequence Gene Silencing Cloning Molecular Carboxylesterase 3 Cells Cultured Gene knockdown Macrophages Articles Cell Biology Molecular biology Cholesterol chemistry Biochemistry COS Cells Cholesteryl ester Carboxylic Ester Hydrolases Intracellular |
| Zdroj: | American Journal of Physiology-Cell Physiology. 303:C427-C435 |
| ISSN: | 1522-1563 0363-6143 |
| DOI: | 10.1152/ajpcell.00103.2012 |
| Popis: | Cholesteryl ester (CE) hydrolysis is the rate-limiting step in the removal of free cholesterol (FC) from macrophage foam cells, and several enzymes have been identified as intracellular CE hydrolases in human macrophages. We have previously reported the antiatherogenic role of a carboxylesterase [carboxylesterase 1 (CES1)], and the objective of the present study was to determine the contribution of CES1 to total CE hydrolytic activity in human macrophages. Two approaches, namely, immune depletion and short hairpin (sh)RNA-mediated knockdown, were used. Immuneprecipitation by a CES1-specific antibody resulted in a 70–80% decrease in enzyme activity, indicating that CES1 is responsible for >70% of the total CE hydrolytic activity. THP1-shRNA cells were generated by stably transfecting human THP1 cells with four different CES1-specific shRNA vectors. Despite a significant (>90%) reduction in CES1 expression both at the mRNA and protein levels, CES1 knockdown neither decreased intracellular CE hydrolysis nor decreased FC efflux. Examination of the underlying mechanisms for the observed lack of effects of CES1 knockdown revealed a compensatory increase in the expression of a novel CES, CES3, which is only expressed at |
| Databáze: | OpenAIRE |
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