title: Interleukin(IL)-4 promotion of CXCL-8 gene transcription is mediated by ERK1/2 pathway in human pulmonary artery endothelial cells.
abstract: Interleukin-4 is central to allergic pulmonary inflammatory responses, but its contribution to airway neutrophilia remains controversial. The endothelium plays a critical role in regulating leukocyte recruitment and migration during inflammation. However, its response to IL-4 is reported to either increase or decrease the production of neutrophil chemotactic factors. We hypothesized that these conflicting findings may be due to the tissue and the size of the vessels from which endothelial cells have been derived. The expression of CXCL-8 by human primary culture umbilical veins endothelial cells (HUVECs), human pulmonary artery endothelial cells (HPAECs), and human pulmonary microvascular endothelial cells (HPMECs) when stimulated with recombinant human IL-4 (rhIL-4) was studied. The chemoattractant property of the cells' supernatants for neutrophils was evaluated using Boyden chambers. The role of the nuclear factor-κB (NF-κB), and mitogen-activated protein kinases (MAPK) in IL-4-induced HPAECs was studied using Western blotting and electrophoretic mobility shift assay (EMSA). We demonstrated that IL-4 increased the mRNA expression and the protein production of CXCL-8 in HPAECs, but not in HUVECs and HPMECs. The supernatants of HAPECs stimulated by IL-4 significantly promoted neutrophils migration in a dose-dependent manner, and was significantly attenuated by an inhibitor of CXCL-8. We also found that extracellular-regulated protein kinase1/2 (ERK1/2) is activated by IL-4 in HPAECs, but not JUN-N-terminal protein kinase (JNK) or p38 MAPK pathway. Furthermore, NF-κB-DNA binding activity, phosphorylation of IκBα and p65 levels were not affected by rhIL-4 in HAPECs. These findings indicate marked functional differences in the response of micro and macro-ECs to IL-4. ERK1/2, rather than NF-κB, JNK and p38 MAPK signaling, plays a role in IL-4 induced chemokine activation. Our results suggest that inhibition of ERK1/2 may be a possible target for airway neutrophilia in allergic lung diseases.
authors.affiliation: Department of Respiratory Diseases, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095# Jiefang Ave., Wuhan 430030, China.
authors.forename: Dao-Feng
authors.initials: DF
authors.lastname: Yang
authors.forename: Hong
authors.initials: H
authors.lastname: Huang
authors.forename: Sha
authors.initials: S
authors.lastname: Guan
authors.forename: Hui-Fen
authors.initials: HF
authors.lastname: Zhu
authors.forename: Chun-Chen
authors.initials: CC
authors.lastname: Zhang
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Zhao
authors.forename: Hui-Juan
authors.initials: HJ
authors.lastname: Fang
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Lavoie
mesh_terms: D015153:Blotting, Western; D002478:Cells, Cultured; D002634:Chemotaxis, Leukocyte / Q000276:immunology; D024202:Electrophoretic Mobility Shift Assay; D042783:Endothelial Cells / Q000276:immunology / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000276:immunology*; D006801:Humans; D015847:Interleukin-4 / Q000276:immunology / Q000378:metabolism*; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D055806:Microvessels / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000276:immunology / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000276:immunology / Q000378:metabolism*; D011014:Pneumonia / Q000276:immunology / Q000378:metabolism; D011651:Pulmonary Artery / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D015398:Signal Transduction; D014158:Transcription, Genetic; D014471:Umbilical Veins / Q000166:cytology / Q000276:immunology / Q000378:metabolism
chemical_list: C508598:IL4 protein, human; D016209:Interleukin-8; D015847:Interleukin-4; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3