title: CXCR1 and CXCR2 silencing modulates CXCL8-dependent endothelial cell proliferation, migration and capillary-like structure formation.
abstract: CXCR1 and CXCR2 are receptors for angiogenic ELR+CXC chemokines and are differentially expressed on endothelial cells; however, their functional significance in angiogenesis remains unclear. In this study, we determined the functional significance of these receptors in modulating endothelial cell phenotype by knocking-down the expression of CXCR1 and/or CXCR2 in human microvascular endothelial cells (HMEC-1) using short-hairpin RNA (shRNA). Cell proliferation, migration, invasion and capillary-like structure (CLS) formation were analyzed. Our data demonstrate that knock-down of CXCR1 and/or CXCR2 expression inhibited endothelial cell proliferation, survival, migration, invasion and CLS formation. Additionally, we examined the mechanism of CXCL8-dependent CXCR1 and/or CXCR2 mediated phenotypic changes by evaluating ERK phosphorylation and cytoskeletal rearrangement and observed inhibition of ERK phosphorylation and cytoskeletal rearrangement in HMEC-1-shCXCR1, HMEC-1-shCXCR2 and HMEC-1-shCXCR1/2 cells. Together, these data demonstrate that CXCR1 and CXCR2 expression plays a critical role in regulating multiple biological activities in human microvascular endothelial cells.
authors.affiliation: Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA. rsingh@unmc.edu
authors.forename: Seema
authors.initials: S
authors.lastname: Singh
authors.forename: Sheng
authors.initials: S
authors.lastname: Wu
authors.forename: Michelle
authors.initials: M
authors.lastname: Varney
authors.forename: Ajay P
authors.initials: AP
authors.lastname: Singh
authors.forename: Rakesh K
authors.initials: RK
authors.lastname: Singh
mesh_terms: D017209:Apoptosis; D002460:Cell Line; D002465:Cell Movement; D049109:Cell Proliferation; D002470:Cell Survival; D042783:Endothelial Cells / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005838:Genotype; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism*; D018919:Neovascularization, Physiologic; D010641:Phenotype; D010766:Phosphorylation; D034622:RNA Interference; D023062:Receptors, Interleukin-8A / Q000235:genetics / Q000378:metabolism*; D023063:Receptors, Interleukin-8B / Q000235:genetics / Q000378:metabolism*; D022502:Stress Fibers / Q000378:metabolism; D014162:Transfection
chemical_list: C508606:CXCL8 protein, human; D016209:Interleukin-8; D023062:Receptors, Interleukin-8A; D023063:Receptors, Interleukin-8B; D048049:Extracellular Signal-Regulated MAP Kinases