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Differing mechanisms of leukocyte recruitment and sensitivity to conditioning by shear stress for endothelial cells treated with tumour necrosis factor‐ α or interleukin‐1 β
Author(s) -
Sheikh Sajila,
Rahman Mahbub,
Gale Zoe,
Luu N Thin,
Stone Philip C W,
Matharu Nick M,
Rainger G Edward Luu,
Nash Gerard B
Publication year - 2005
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1038/sj.bjp.0706281
Subject(s) - tumor necrosis factor alpha , chemokine , cytokine , immunology , integrin , cell adhesion molecule , umbilical vein , selectin , microbiology and biotechnology , receptor , biology , chemistry , inflammation , medicine , in vitro , biochemistry
1 The cytokines tumour necrosis factor‐ α (TNF α ) and interleukin‐1 β (IL‐1B) induce endothelial cells to recruit leukocytes. However, the exact adhesion and activation mechanisms induced by each cytokine, and their relative sensitivities to modulation by endothelial exposure to shear stress remain unclear. 2 We cultured human umbilical vein endothelial cells (HUVEC) in glass capillaries at various shear stresses, with TNF α or IL‐1B added for the last 4 h. Subsequently, human neutrophils were perfused over the HUVEC, and adhesion and migration were recorded. 3 Both cytokines induced dose‐dependent capture of neutrophils. However, while conditioning of HUVEC by increasing shear stress for 24 h diminished their response to TNF α , the response of HUVEC to IL‐1B was similar at all shear stresses. The differing sensitivities were evident at levels of adhesive function and mRNA for adhesion molecules and chemokines. 4 Analysis of nuclear factor κ B (NF‐ κ B)/Rel family of transcription factors showed that their expression and activation were modified by exposure to shear stress, but did not obviously explain differential responses to TNF α and IL‐1B. 5 Antibodies against selectins were effective against capture of neutrophils on TNF α ‐treated but not IL‐1B‐treated HUVEC. Stable adhesion was supported by β 2‐integrins in each case. Activation of neutrophils occurred dominantly through CXC‐chemokine receptor 2 (CXCR2) for TNF α ‐treated HUVEC, while blockade of CXCR1, CXCR2 and of platelet‐activating factor receptors caused additive inhibition of migration on IL‐1B‐treated HUVEC. 6 The mechanisms which underlie neutrophil recruitment, and their modulation by the haemodynamic environment, differ between cytokines. Interventions aimed against leukocyte recruitment may not operate equally in different inflammatory milieu.British Journal of Pharmacology (2005) 145 , 1052–1061. doi: 10.1038/sj.bjp.0706281