title: Enhancement of CCL15 expression and monocyte adhesion to endothelial cells (ECs) after hypoxia/reoxygenation and induction of ICAM-1 expression by CCL15 via the JAK2/STAT3 pathway in ECs.
abstract: CCL15, a member of the CC chemokine family, is a potent chemoattractant for leukocytes and endothelial cells (ECs). Given that chemokines play key roles in vascular inflammation, we investigated the effects of hypoxia/reoxygenation (H/R) on expression of human CCL15 and a role of CCL15 in upregulating ICAM-1 in ECs. We found that exposure of ECs to H/R increased expression of CCL15 and ICAM-1, which resulted in an increase in monocyte adhesivity to the ECs. Further studies revealed that knockdown of CCL15 or CCR1 attenuated expression of ICAM-1 in ECs after H/R, suggesting that expression of ICAM-1 is upregulated by CCL15. Stimulation of ECs with CCL15 significantly increased expression of ICAM-1 predominantly via the CCR1 receptor. We observed that phosphorylation of JAK2 and STAT3 was stimulated by CCL15 treatment of ECs. Results from reporter and chromatin immunoprecipitation assays revealed that CCL15 activates transcription from the IFN-γ activation site promoter and stimulates binding of STAT3 to the ICAM-1 promoter. Our data also showed that CCL15 increased cell adhesion of human monocytes to ECs under static and shear-stress conditions. Pretreatment of these cells with inhibitors for JAK, PI3K, and AKT prevented the CCL15-induced expression of ICAM-1 and monocyte adhesion to ECs, suggesting the involvement of those signaling molecules in ICAM-1 gene activation by CCL15. The results suggest that CCR1 and its ligands may be a potential target for treating inflammatory diseases involving upregulation of cell adhesion molecules.
authors.affiliation: Graduate School of Biotechnology, Kyung Hee University,Yongin 446-701, Republic of Korea.
authors.forename: Keun Hyung
authors.initials: KH
authors.lastname: Park
authors.forename: Tae Hoon
authors.initials: TH
authors.lastname: Lee
authors.forename: Chan Woo
authors.initials: CW
authors.lastname: Kim
authors.forename: Jiyoung
authors.initials: J
authors.lastname: Kim
mesh_terms: D015153:Blotting, Western; D002448:Cell Adhesion / Q000502:physiology; D002478:Cells, Cultured; D019742:Chemokines, CC / Q000096:biosynthesis*; D047369:Chromatin Immunoprecipitation; D042783:Endothelial Cells / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D000860:Hypoxia / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis*; D053614:Janus Kinase 2 / Q000378:metabolism; D019402:Macrophage Inflammatory Proteins / Q000096:biosynthesis*; D009000:Monocytes / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D034741:RNA, Small Interfering; D060888:Real-Time Polymerase Chain Reaction; D015424:Reperfusion; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050796:STAT3 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D014162:Transfection; D015854:Up-Regulation
chemical_list: C108814:CCL15 protein, human; D019742:Chemokines, CC; D019402:Macrophage Inflammatory Proteins; D034741:RNA, Small Interfering; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D018799:Intercellular Adhesion Molecule-1; C507924:JAK2 protein, human; D053614:Janus Kinase 2