Enhancement by neutrophils of collagen degradation by corneal fibroblasts.
Activated corneal fibroblasts and infiltrated leukocytes are thought to contribute to corneal ulceration. The potential roles of neutrophil-fibroblast and cell-matrix interactions in the degradation of stromal collagen associated with corneal ulceration have now been investigated with the use of three-dimensional cultures of rabbit cells in collagen gels. Degradation of collagen fibrils during culture was measured by spectrophotometric determination of released hydroxyproline. Whereas corneal fibroblasts alone degraded collagen fibrils to a small extent, neutrophils did not. However, the addition of neutrophils or neutrophil-conditioned medium (CM) to cultures of corneal fibroblasts resulted in a marked increase in the amount of collagen degraded by the fibroblasts. The effect of CM from neutrophils cultured in collagen gels on collagen degradation by corneal fibroblasts was greater than that of medium conditioned by neutrophils in monolayer culture. Immunoblot as well as reverse transcription and real-time polymerase chain reaction analyses revealed that neutrophil-CM stimulated the synthesis of matrix metalloproteinase (MMP)-1 and MMP-3 by corneal fibroblasts. The stimulatory effect of neutrophils on collagen degradation by corneal fibroblasts was inhibited by the synthetic MMP inhibitor ilomastat and by interleukin-1 (IL-1) receptor antagonist. These results suggest that factors secreted by collagen-stimulated neutrophils augment collagen degradation by corneal fibroblasts through a stimulatory effect on MMP synthesis and that IL-1 released by neutrophils may contribute to this effect.
Li
Qin
Q
Department of Biomolecular Recognition and Ophthalmology, Yamaguchi University School of Medicine, Ube City, Japan.
Fukuda
Ken
K
Lu
Ying
Y
Nakamura
Yoshikuni
Y
Chikama
Tai-Ichiro
T
Kumagai
Naoki
N
Nishida
Teruo
T
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D018920:Coculture Techniques; D003094:Collagen / Q000378:metabolism*; D003319:Corneal Stroma / Q000166:cytology*; D017931:DNA Primers / Q000737:chemistry; D005347:Fibroblasts / Q000378:metabolism*; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000378:metabolism; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000235:genetics / Q000378:metabolism; D019278:Matrix Metalloproteinase 3 / Q000235:genetics / Q000378:metabolism; D009504:Neutrophils / Q000378:metabolism*; D011817:Rabbits; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012795:Sialoglycoproteins / Q000037:antagonists & inhibitors / Q000378:metabolism
D017931:DNA Primers; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D012795:Sialoglycoproteins; D003094:Collagen; D019278:Matrix Metalloproteinase 3; D020781:Matrix Metalloproteinase 1