Mammalian cells synthesize hundreds of different variants of their prominent membrane lipid phosphatidylcholine (PC), all differing in the side chain composition. This batch is constantly remodeled by the Lands cycle, a metabolic pathway replacing one chain at the time. Using the alkyne lipid lyso-phosphatidylpropargylcholine (LpPC), a precursor and intermediate in PC synthesis and remodeling, we study both processes in brain endothelial bEND3 cells. A novel method for multiplexed sample analysis by mass spectrometry is developed that offers high throughput and molecular species resolution of the propargyl-labeled PC lipids. Their time resolved profiles and kinetic parameters of metabolism demonstrate the plasticity of the PC pool and the acute handling of lipid influx in endothelial cells differs from that in hepatocytes. Side chain remodeling as a form of lipid cycling adapts the PC pool to the cells need and maintains lipid homeostasis. We estimate that endothelial cells possess the theoretical capacity to remodel up to 99% of their PC pool within 3.5 h using the Lands cycle. However, PC species are not subjected stochastically to this remodeling pathway as different species containing duplets of saturated, omega-3 and omega-6 side chains show different decay kinetics. Our findings emphasize the essential function of Lands cycling for monitoring and adapting the side chain composition of PC in endothelial cells.
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http://dx.doi.org/10.1016/j.jlr.2025.100773 | DOI Listing |
J Cell Mol Med
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Department of Cell Biology, National Cerebral and Cardiovascular Center Research Institute.
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Department of Medical Biotechnology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran; Non-Communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran. Electronic address:
L-asparaginase is a critical therapeutic enzyme for treating acute lymphoblastic leukemia (ALL), a common childhood malignancy. In this study, the L-asparaginase coding sequence from halophilic Vibrio sp. (GBPx3) was cloned, expressed in Escherichia coli, and characterized.
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LIMES Life and Medical Sciences Institute, University of Bonn, Bonn, Germany. Electronic address:
Mammalian cells synthesize hundreds of different variants of their prominent membrane lipid phosphatidylcholine (PC), all differing in the side chain composition. This batch is constantly remodeled by the Lands cycle, a metabolic pathway replacing one chain at the time. Using the alkyne lipid lyso-phosphatidylpropargylcholine (LpPC), a precursor and intermediate in PC synthesis and remodeling, we study both processes in brain endothelial bEND3 cells.
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