Effects of lysophosphatidylcholine on monolayer cell permeability of human coronary artery endothelial cells.
BACKGROUND
Lysophosphatidylcholine (LysoPC) is a product of phosphatidylcholine hydrolysis by phospholipase A2, which is associated with atherosclerosis. However, the underlying molecular mechanisms are still unclear. The purpose of this study was to determine the effects of LysoPC on monolayer permeability of human coronary artery endothelial cells (HCAECs).


METHODS
HCAECs were cultured with LysoPC in a dose- and time-dependent manner. Monolayer permeability was studied by using a transwell system with a Texas-Red-labeled dextran tracer. The messenger RNA and protein levels of endothelial tight junction proteins were determined with the use of real-time reverse transcriptase-polymerase chain reaction and Western blot analysis, respectively. Superoxide anion levels were determined with the use of fluorescent dye dihydroethidium-based flow cytometry analysis. Activation of mitogen-activated protein kinases was determined by performing Bio-Plex immunoassay.


RESULTS
LysoPC (30 micromol/L) increased monolayer permeability by 53% and decreased the messenger RNA levels of zonula occludens-1, occludin, claudin-1, and junctional adhesion molecule by 44%, 53%, 50%, and 52%, respectively, compared with controls (P < .05). Western blot analysis showed reduced protein levels of these tight junction molecules. LysoPC (15 and 30 micromol/L) also increased superoxide anion production by 54% and 58%, respectively, compared with controls (P < .05). Antioxidant seleno-L-methionine (20 and 30 micromol/L) inhibited LysoPC (30 micromol/L)-induced permeability by 42% and 68%, respectively (P < .05). Furthermore, LysoPC (30 micromol/L) activated c-Jun N-terminal kinase and p38 phosphorylation, but not extracellular signal-related kinase 1/2, within 5 to 10 minutes.


CONCLUSIONS
LysoPC increases monolayer permeability and reduces the expression of tight junction molecules in HCAECs through oxidative stress and activation of c-Jun N-terminal kinase and p38 mitogen-activated protein kinase. The antioxidant can effectively block LysoPC-induced endothelial permeability.
Yan
Shaoyu
S
Molecular Surgeon Research Center, Division of Vascular Surgery and Endovascular Therapy, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA.
Chai
Hong
H
Wang
Hao
H
Yang
Hui
H
Nan
Bicheng
B
Yao
Qizhi
Q
Chen
Changyi
C
D015820:Cadherins / Q000235:genetics; D002463:Cell Membrane Permeability / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D062445:Claudin-1; D003331:Coronary Vessels; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D008244:Lysophosphatidylcholines / Q000494:pharmacology*; D008565:Membrane Proteins / Q000235:genetics; D062793:Occludin; D020133:Reverse Transcriptase Polymerase Chain Reaction
C568108:CLDN1 protein, human; D015820:Cadherins; D062445:Claudin-1; C502403:FAT1 protein, human; D008244:Lysophosphatidylcholines; D008565:Membrane Proteins; C568985:OCLN protein, human; D062793:Occludin