title: Vascular endothelial growth factor induces protein kinase D-dependent production of proinflammatory cytokines in endothelial cells.
abstract: Emerging evidence indicates that vascular endothelial growth factor (VEGF) plays a critical role in host inflammatory responses in several disease states, including atherosclerosis, sepsis, and rheumatoid arthritis. In this study, we determined the effect of VEGF on endothelial induction of proinflammatory cytokines and investigated the responsible signal pathways. By using a cytokine antibody array that detects the end point protein products released from endothelial cells (ECs), we found that VEGF, via VEGF receptor 2 (VEGFR2), predominantly induced the production of proinflammatory cytokine interleukin (IL)-6 and CXC chemokines IL-8 and growth-related oncogene-alpha (GRO-alpha) in ECs but not in leukocytes among 36 cytokines in the array. The production of these inflammatory cytokines by VEGF was much stronger than the induction of cell adhesion molecule in ECs. We further found that the cytokine production by VEGF was essentially mediated by the Gö-6976-sensitive protein kinase D (PKD) family kinases. Importantly, the VEGF-induced production of IL-6, IL-8, and GRO-alpha was inhibited approximately 70%, 40%, or 37% by PKD1 silencing (more than 90% knockdown) with three small interference RNAs that target different PKD1 regions. Moreover, silencing PKD2 downregulated VEGFR2 and markedly inhibited the cytokine production by VEGF in ECs. Our results indicate that VEGF, via VEGFR2-PKD1 axis, induces the production of proinflammatory cytokine IL-6, IL-8, and GRO-alpha in ECs but not in leukocytes, which may offer new insights into the mechanism of the proinflammatory activity of VEGF.
authors.affiliation: Dept. of Biochemistry, The Univ. of Texas Health Science Center at Tyler, 11937 US Highway 271, Tyler, TX 75708, USA.
authors.forename: Qin
authors.initials: Q
authors.lastname: Hao
authors.forename: Linping
authors.initials: L
authors.lastname: Wang
authors.forename: Hua
authors.initials: H
authors.lastname: Tang
mesh_terms: D002227:Carbazoles / Q000494:pharmacology; D002478:Cells, Cultured; D054360:Chemokine CXCL1 / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism*; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology* / Q000276:immunology*; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D007962:Leukocytes / Q000201:enzymology / Q000276:immunology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000091283:Protein Kinase D2; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011494:Protein Kinases / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D015854:Up-Regulation; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
chemical_list: C475829:CXCL1 protein, human; C508606:CXCL8 protein, human; D002227:Carbazoles; D054360:Chemokine CXCL1; D016207:Cytokines; C508600:IL6 protein, human; D018836:Inflammation Mediators; D015850:Interleukin-6; D016209:Interleukin-8; D000091283:Protein Kinase D2; D047428:Protein Kinase Inhibitors; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; C467484:VEGFA protein, human; D019010:Vascular Cell Adhesion Molecule-1; D042461:Vascular Endothelial Growth Factor A; C081021:Go 6976; D011494:Protein Kinases; C089212:protein kinase D; D040301:Vascular Endothelial Growth Factor Receptor-2; D011493:Protein Kinase C