Lysophosphatidylcholine regulates human microvascular endothelial cell expression of chemokines.
The role of lysophosphatidylcholine (LPC) in the induction of MCP-1, IL-8 and RANTES, which are chemotactic factors to monocytes, neutrophils and lymphocytes, respectively, by human vascular endothelial cells (EC), was examined. LPC induced the expression of MCP-1 and IL-8 in a concentration- and time-dependent manner in microvascular EC (MVEC) and in large vessel EC from aorta, pulmonary artery and umbilical vein. LPC also induced RANTES in MVEC but not in large vessel EC. Signaling pathways responsible for LPC induction of chemokines were examined in MVEC. LPC and TNFalpha, a cytokine secreted in sites of inflammation, additively stimulated RANTES expression. LPC did not augment TNFalpha induction of MCP-1 or IL-8. A platelet-activating factor receptor antagonist (BN52021) failed to block LPC induction of MVEC chemokines, but the G(i)-protein inhibitor pertussis toxin partially blocked LPC induction of RANTES and IL-8. LPC activated multiple kinases in MVEC; it increased the phosphorylation of ERK1/2, AKT and p38 MAP kinase in a time-dependent manner. An inhibitor of the MAPK/ERK pathway, PD98059, blocked the phosphorylation of ERK1/2 and RANTES induction by LPC, but augmented IL-8 induction. LY294002, a specific inhibitor of phosphoinositide 3 kinase (PI3 kinase), blunted the phosphorylation of AKT and inhibited LPC induction of RANTES more strongly than IL-8. Inhibition of p38 MAP kinase pathway by SB202190 also blocked LPC-induced expression of IL-8 and RANTES. Our results suggest that LPC induction of chemokines in MVEC is distinct from that in large vessel EC, and required the activities of MAP kinases and PI3 kinase for the induction of RANTES and IL-8. We speculate that the presence of LPC, a bioactive lipid product of phospholipase A(2) (PLA(2)) and a constituent of oxidized low-density lipoprotein, can differentially influence the chemotaxis of particular leukocyte subpopulations during inflammation.
Department of Clinical Pathology @ L30, The Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA. murugeg@ccf.org
Gurunathan
G
Murugesan
M R
MR
Sandhya Rani
Christina E
CE
Gerber
Chaitali
C
Mukhopadhyay
Richard M
RM
Ransohoff
Guy M
GM
Chisolm
Kandice
K
Kottke-Marchant
D001011:Aorta / Q000378:metabolism; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000096:biosynthesis; D018946:Chemokine CCL5 / Q000096:biosynthesis; D018925:Chemokines / Q000378:metabolism*; D002633:Chemotaxis; D002867:Chromones / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D016209:Interleukin-8 / Q000096:biosynthesis; D008244:Lysophosphatidylcholines / Q000494:pharmacology*; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000378:metabolism; D009025:Morpholines / Q000494:pharmacology; D037342:Pertussis Toxin; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000187:drug effects / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D011651:Pulmonary Artery / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D015398:Signal Transduction; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D014471:Umbilical Veins / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases
D018932:Chemokine CCL2; D018946:Chemokine CCL5; D018925:Chemokines; D002867:Chromones; D004791:Enzyme Inhibitors; D005419:Flavonoids; D007093:Imidazoles; D016209:Interleukin-8; D008244:Lysophosphatidylcholines; D009025:Morpholines; D011518:Proto-Oncogene Proteins; D011725:Pyridines; D014409:Tumor Necrosis Factor-alpha; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D037342:Pertussis Toxin; C494918:AKT1 protein, human; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C090942:4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one