ABSTRACT
The migration of endothelial cells (ECs) plays critical roles in vascular physiology and pathology. The receptors CXCR1 and CXCR2, known as G protein-coupled receptors which are essential for migratory response of ECs toward the shear stress-dependent CXCL8 (interleukin-8), are potential mechano-sensors for mechanotransduction of the hemodynamic forces. In present study, the mRNA and protein expression of CXCR1 and CXCR2 in EA.hy926 cells was detected by RT-PCR and Western blot analysis under three conditions of laminar shear stress (5.56, 10.02 and 15.27 dyn/cm(2)) respectively. Using a scratched-wound assay, the effects of CXCR1 and CXCR2 were assessed by the percentage of wound closure while CXCR1 and CXCR2 were functional blocked by the CXCL8 receptor antibodies. The results showed that the mRNA and protein expression of CXCR1 and CXCR2 was both upregulated by 5.56 dyn/cm(2) laminar shear stress, but was both downregulated by 15.27 dyn/cm(2). The wound closure was inhibited significantly while cells were treated with those antibodies in all the conditions. It was suggested that CXCR1 and CXCR2 are involved in mediating the laminar shear stress-induced EC migration. Taken together, these findings indicated that CXCR1 and CXCR2 are novel mechano-sensors mediating laminar shear stress-induced EC migration. Understanding this expanded mechanism of laminar shear stress-induced cell migration will provide novel molecular targets for therapeutic intervention in cancer and cardiovascular diseases.
Subject(s)
Cell Movement , Endothelial Cells/cytology , Endothelial Cells/metabolism , Mechanotransduction, Cellular , Receptors, Interleukin-8A/metabolism , Receptors, Interleukin-8B/metabolism , Stress, Mechanical , Antibodies/pharmacology , Cell Movement/drug effects , Down-Regulation/drug effects , Down-Regulation/genetics , Endothelial Cells/drug effects , Humans , Mechanotransduction, Cellular/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Interleukin-8A/genetics , Receptors, Interleukin-8B/genetics , Up-Regulation/drug effects , Up-Regulation/genetics , Wound Healing/drug effectsABSTRACT
CXCR1 and CXCR2 are important receptors in regulating vascular endothelial cell activities. In order to elucidate the role of CXCR1/2 in shear stress-induced endothelial cell migration, we have investigated the expression levels of CXCR1 and CXCR2 in the endothelial cells exposed to shear stress. In the experiment, anti-IL8RA and anti-IL8RB were used to antagonize CXCR1 and CXCR2. Different shear stresses were generated in a flow chamber; scratch test was carried out to compare endothelial cell migration in the control group and the receptor-antagonized groups. The results indicated that the migration of endothelial cells was restrained effectively after CXCR1 and CXCR2 were antagonized by anti-IL8RA and anti-IL8RB. And anti-IL8RA showed a stronger inhibitive effect than did anti-IL8RB (P<0.05). In the group with both receptor antagonisms, the migration was further inhibited. These results suggest that both CXCR1 and CXCR2 are important factors in mediating the migration of endothelial cells induced by shear stress, and CXCR1 fulfills a more important role.
