Antisense to LOX-1 inhibits oxidized LDL-mediated upregulation of monocyte chemoattractant protein-1 and monocyte adhesion to human coronary artery endothelial cells.
BACKGROUND
We have recently demonstrated a lectin-like receptor for oxidized (ox)-LDL (LOX-1) in human coronary artery endothelial cells (HCAECs). This receptor is upregulated by ox-LDL. The present study examined the significance of LOX-1 in monocyte adhesion to HCAECs and endothelial injury in response to ox-LDL.


RESULTS
HCAECs were incubated in the presence of antisense oligodeoxynucleotides to the 5'-coding sequence of the human LOX-1 gene (0.5 microm/L). Basal LOX-1 mRNA and protein were suppressed by antisense LOX-1. Ox-LDL-mediated upregulation of LOX-1 was also suppressed by antisense LOX-1. Incubation of HCAECs with ox-LDL (40 microg/mL) for 24 hours markedly increased monocyte chemoattractant protein-1 (MCP-1) mRNA and protein expression as well as monocyte adhesion to HCAECs (P<0.01). After 48 hours of preincubation of HCAECs with antisense LOX-1, ox-LDL-mediated upregulation of MCP-1 and monocyte adhesion to HCAECs both were suppressed (P<0.01), whereas sense LOX-1 had no effect. Whereas antisense or sense LOX-1 alone (both 0.5 nmol/L) did not injure the cells, antisense LOX-1, but not sense LOX-1, reduced ox-LDL-mediated HCAEC injury, determined as LDH release (P<0.01). Activation of mitogen-activated protein kinase (MAPK) may play a critical role in signal transduction in ox-LDL-mediated alteration in MCP-1 expression, since antisense LOX-1, but not the sense LOX-1, completely inhibited the ox-LDL-induced MAPK activation.


CONCLUSIONS
These observations with the first use of a specific antisense to human LOX-1 mRNA suggest that LOX-1 is a key factor in ox-LDL-mediated monocyte adhesion to HCAECs.
Li
D
D
Departments of Medicine and Physiology, University of Florida and VA Medical Center, Gainesville, FL 32610, USA.
Mehta
J L
JL
D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000378:metabolism*; D003331:Coronary Vessels / Q000187:drug effects / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008077:Lipoproteins, LDL / Q000494:pharmacology / Q000502:physiology*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009000:Monocytes / Q000502:physiology*; D016376:Oligonucleotides, Antisense / Q000378:metabolism / Q000494:pharmacology; D011973:Receptors, LDL / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D051131:Receptors, Oxidized LDL; D051127:Scavenger Receptors, Class E; D015854:Up-Regulation / Q000187:drug effects
D018932:Chemokine CCL2; D008077:Lipoproteins, LDL; C495137:OLR1 protein, human; D016376:Oligonucleotides, Antisense; D011973:Receptors, LDL; D051131:Receptors, Oxidized LDL; D051127:Scavenger Receptors, Class E; C099252:oxidized low density lipoprotein; D007770:L-Lactate Dehydrogenase; D020928:Mitogen-Activated Protein Kinases