Abstract
A sequential model involving chemokines has been proposed for leukocyte extravasation into areas of inflammation; however, site-specific aspects remain to be elucidated. Hence, we studied the role of chemokines produced by mesangial (MC) or glomerular endothelial cells (GEC) and their receptors in glomerular recruitment of monocytes. Stimulation of MC with TNF-alpha up-regulated mRNA and protein of CC and CXC chemokines but not constitutive expression of the CX(3)C chemokine fractalkine. While growth-related activity (GRO)-alpha was immobilized to MC proteoglycans, monocyte chemotactic protein (MCP)-1 was secreted into the soluble phase. Firm adhesion and sequestration of monocytes on activated MC was supported by the GRO-alpha receptor CXCR2 and to a lesser extent by CX(3)CR, whereas the MCP-1 receptor CCR2 contributed to their transendothelial chemotaxis toward activated MC. In contrast, fractalkine mRNA and protein was induced by TNF-alpha in transformed rat GEC, and both CXCR2 and CX(3)CR mediated monocyte arrest on GEC in shear flow. The relevance of these mechanisms was confirmed in a rat nephrotoxic nephritis model where acute glomerular macrophage recruitment was profoundly inhibited by blocking CXCR2 or CCR2. In conclusion, our results epitomize a combinatorial model in which chemokines play specialized roles in driving glomerular monocyte recruitment and emphasize an important role for CXCR2 in macrophage infiltration during early phases of nephrotoxic nephritis.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Animals
-
Cell Adhesion / immunology
-
Cell Line
-
Cell Membrane / immunology
-
Cell Membrane / metabolism
-
Cell Migration Inhibition
-
Cell Movement / immunology*
-
Cells, Cultured
-
Chemokine CCL2 / metabolism
-
Chemokine CX3CL1
-
Chemokine CXCL1
-
Chemokines, CX3C / biosynthesis
-
Chemokines, CXC / biosynthesis
-
Chemokines, CXC / genetics
-
Chemokines, CXC / physiology*
-
Chemotactic Factors / biosynthesis
-
Chemotaxis, Leukocyte / immunology
-
Diffusion Chambers, Culture
-
Disease Models, Animal
-
Endothelium, Vascular / immunology
-
Endothelium, Vascular / pathology
-
Glomerular Mesangium / immunology
-
Glomerular Mesangium / metabolism
-
Glomerular Mesangium / pathology
-
Glomerulonephritis / immunology*
-
Glomerulonephritis / pathology
-
Growth Substances / biosynthesis
-
Humans
-
Intercellular Signaling Peptides and Proteins*
-
Interleukin-8 / biosynthesis
-
Interleukin-8 / metabolism
-
Kidney Glomerulus / blood supply
-
Kidney Glomerulus / immunology*
-
Kidney Glomerulus / metabolism
-
Kidney Glomerulus / pathology
-
Male
-
Membrane Proteins / biosynthesis
-
Monocytes / immunology*
-
Monocytes / pathology
-
RNA, Messenger / biosynthesis
-
Rats
-
Rats, Sprague-Dawley
-
Receptors, CCR2
-
Receptors, Chemokine / antagonists & inhibitors
-
Receptors, Interleukin-8B / antagonists & inhibitors
-
Receptors, Interleukin-8B / physiology*
-
Tumor Necrosis Factor-alpha / physiology
-
Up-Regulation / immunology
Substances
-
CCR2 protein, human
-
CX3CL1 protein, human
-
CXCL1 protein, human
-
Ccr2 protein, rat
-
Chemokine CCL2
-
Chemokine CX3CL1
-
Chemokine CXCL1
-
Chemokines, CX3C
-
Chemokines, CXC
-
Chemotactic Factors
-
Cx3cl1 protein, rat
-
Cxcl1 protein, rat
-
Growth Substances
-
Intercellular Signaling Peptides and Proteins
-
Interleukin-8
-
Membrane Proteins
-
RNA, Messenger
-
Receptors, CCR2
-
Receptors, Chemokine
-
Receptors, Interleukin-8B
-
Tumor Necrosis Factor-alpha