Protein kinase Cdelta mediates lysophosphatidic acid-induced NF-kappaB activation and interleukin-8 secretion in human bronchial epithelial cells.
Lysophosphatidic acid (LPA), a potent bioactive lipid, elicits many of its biological actions via the specific G-protein-coupled receptors LPA1, LPA2, LPA3, and LPA4. Recently, we have shown that LPA-induced transactivation of platelet-derived growth factor receptor-beta is regulated by phospholipase D2 in human bronchial epithelial cells (HBEpCs) (Wang, L., Cummings, R. J., Zhao, Y., Kazlauskas, A., Sham, J., Morris, A., Brindley, D. N., Georas, S., and Natarajan, V. (2003) J. Biol. Chem. 278, 39931-39940). Here, we report that protein kinase Cdelta (PKCdelta) mediates LPA-induced NF-kappaB transcription and interleukin-8 (IL-8) secretion in HBEpCs. Treatment of HBEpCs with LPA increased both IL-8 gene and protein expression, which was coupled to Gi and G(12/13) proteins. LPA caused a marked activation of NF-kappaB in HBEpCs as determined by IkappaB phosphorylation and of NF-kappaB nuclear translocation and a strong induction of NF-kappaB promoter-mediated luciferase activity. Furthermore, LPA-activated PKCdelta and the LPA-mediated activation of NF-kappaB and IL-8 production were attenuated by overexpression of dominant-negative PKCdelta and rottlerin. Intratracheal administration of LPA in mice resulted in elevated levels of macrophage inflammatory protein-2, a murine homolog of IL-8, and an influx of neutrophils in the bronchoalveolar lavage fluid. These results demonstrate for the first time that LPA is a potent stimulator of IL-8 production in HBEpCs, which involves PKCdelta/NF-kappaB signaling pathways.
Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21224, USA.
Rhett
R
Cummings
Yutong
Y
Zhao
David
D
Jacoby
E William
EW
Spannhake
Motoi
M
Ohba
Joe G N
JG
Garcia
Tonya
T
Watkins
Donghong
D
He
Bahman
B
Saatian
Viswanathan
V
Natarajan
D000098:Acetophenones / Q000494:pharmacology; D021581:Active Transport, Cell Nucleus; D000818:Animals; D001578:Benzopyrans / Q000494:pharmacology; D015153:Blotting, Western; D018893:Bronchoalveolar Lavage; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D054426:Chemokine CXCL2; D018925:Chemokines / Q000378:metabolism; D016207:Cytokines / Q000096:biosynthesis / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D005786:Gene Expression Regulation; D006801:Humans; D007249:Inflammation; D016209:Interleukin-8 / Q000378:metabolism; D008156:Luciferases / Q000378:metabolism; D008246:Lysophospholipids / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D016328:NF-kappa B / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D010766:Phosphorylation; D020033:Protein Isoforms; D011493:Protein Kinase C / Q000502:physiology*; D051745:Protein Kinase C-delta; D021381:Protein Transport; D012313:RNA / Q000378:metabolism; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D015533:Transcriptional Activation; D014162:Transfection
D000098:Acetophenones; D001578:Benzopyrans; D054426:Chemokine CXCL2; D018925:Chemokines; C404915:Cxcl2 protein, mouse; D016207:Cytokines; D018076:DNA, Complementary; D016209:Interleukin-8; D008246:Lysophospholipids; D016328:NF-kappa B; D020033:Protein Isoforms; D012313:RNA; C085746:rottlerin; D008156:Luciferases; C497259:Prkcd protein, mouse; D020797:Receptor, Platelet-Derived Growth Factor beta; C497258:PRKCD protein, human; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; C032881:lysophosphatidic acid