Gelatinases mediate neutrophil recruitment in vivo: evidence for stimulus specificity and a critical role in collagen IV remodeling.

TY - JOUR

T1 - Gelatinases mediate neutrophil recruitment in vivo: evidence for stimulus specificity and a critical role in collagen IV remodeling.

AU - Reichel, Christoph A

AU - Rehberg, Markus

AU - Bihari, Peter

AU - Moser, Christian M

AU - Linder, Stefan

AU - Khandoga, Andrej

AU - Krombach, Fritz

PY - 2008/4/1

Y1 - 2008/4/1

N2 - In the present study, the role of gelatinases [matrix metalloproteinase-2 and -9 (MMP-2 and -9)] for leukocyte rolling, adherence, and transmigration was analyzed in the mouse cremaster muscle under different inflammatory conditions including ischemia-reperfusion (I/R) and stimulation with MIP-1alpha or platelet-activating factor (PAF). Using zymography, we detected a significant elevation of MMP-9 activity in response to the stimuli applied, and MMP-2 expression was not altered. However, treatment with a specific MMP-2/-9 inhibitor significantly abrogated elevated MMP-9 activity. As observed by intravital microscopy, all inflammatory conditions induced a significant increase in numbers of adherent and transmigrated leukocytes (>80% Ly-6G(+) neutrophils). Blockade of gelatinases significantly diminished I/R- and MIP-1alpha-induced leukocyte adherence and subsequent transmigration, and upon stimulation with PAF, gelatinase inhibition had no effect on leukocyte adherence but selectively reduced leukocyte transmigration. Concomitantly, we observed an increase in microvascular permeability after I/R and upon stimulation with MIP-1alpha or PAF, which was almost completely abolished in the inhibitor-treated groups. Using immunofluorescence staining and confocal microscopy, discontinuous expression of collagen IV, a major substrate of gelatinases within the perivascular basement membrane (BM), was detected in postcapillary venules. Analysis of intensity profiles demonstrated regions of low fluorescence intensity, whose size was enlarged significantly after I/R and upon stimulation with MIP-1alpha or PAF as compared with unstimulated controls. However, this enlargement was abolished significantly after inhibition of gelatinases, respectively. In conclusion, these data demonstrate that gelatinases strictly regulate microvascular permeability and BM remodeling during the early inflammatory response, whereas concomitant leukocyte recruitment is mediated by these proteases in a stimulus-specific manner.

AB - In the present study, the role of gelatinases [matrix metalloproteinase-2 and -9 (MMP-2 and -9)] for leukocyte rolling, adherence, and transmigration was analyzed in the mouse cremaster muscle under different inflammatory conditions including ischemia-reperfusion (I/R) and stimulation with MIP-1alpha or platelet-activating factor (PAF). Using zymography, we detected a significant elevation of MMP-9 activity in response to the stimuli applied, and MMP-2 expression was not altered. However, treatment with a specific MMP-2/-9 inhibitor significantly abrogated elevated MMP-9 activity. As observed by intravital microscopy, all inflammatory conditions induced a significant increase in numbers of adherent and transmigrated leukocytes (>80% Ly-6G(+) neutrophils). Blockade of gelatinases significantly diminished I/R- and MIP-1alpha-induced leukocyte adherence and subsequent transmigration, and upon stimulation with PAF, gelatinase inhibition had no effect on leukocyte adherence but selectively reduced leukocyte transmigration. Concomitantly, we observed an increase in microvascular permeability after I/R and upon stimulation with MIP-1alpha or PAF, which was almost completely abolished in the inhibitor-treated groups. Using immunofluorescence staining and confocal microscopy, discontinuous expression of collagen IV, a major substrate of gelatinases within the perivascular basement membrane (BM), was detected in postcapillary venules. Analysis of intensity profiles demonstrated regions of low fluorescence intensity, whose size was enlarged significantly after I/R and upon stimulation with MIP-1alpha or PAF as compared with unstimulated controls. However, this enlargement was abolished significantly after inhibition of gelatinases, respectively. In conclusion, these data demonstrate that gelatinases strictly regulate microvascular permeability and BM remodeling during the early inflammatory response, whereas concomitant leukocyte recruitment is mediated by these proteases in a stimulus-specific manner.

KW - Animals

KW - Cell Membrane Permeability

KW - Collagen Type IV

KW - Gelatinases

KW - Hemodynamics

KW - Leukocyte Count

KW - Male

KW - Matrix Metalloproteinase 2

KW - Matrix Metalloproteinase 9

KW - Mice

KW - Mice, Inbred C57BL

KW - Neutrophils

KW - Tissue Inhibitor of Metalloproteinase-2

KW - Tissue Inhibitor of Metalloproteinases

U2 - 10.1189/jlb.1007666

DO - 10.1189/jlb.1007666

M3 - SCORING: Journal article

C2 - 18174361

VL - 83

SP - 864

EP - 874

JO - J LEUKOCYTE BIOL

JF - J LEUKOCYTE BIOL

SN - 0741-5400

IS - 4

M1 - 4

ER -