Synergistic neutrophil elastase-cytokine interaction degrades collagen in three-dimensional culture.
Proteolytic degradation of extracellular matrix is thought to play an important role in many lung disorders. In the current study, human lung fibroblasts were cast into type I collagen gels and floated in medium containing elastase, cytomix (combination of tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma), or both. After 5 days, gel collagen content was determined by measuring hydroxyproline. Elastase alone did not result in collagen degradation, but in the presence of fibroblasts, elastase reduced hydroxyproline content to 75.2% (P < 0.01), whereas cytomix alone resulted in reduction of hydroxyproline content to 93% (P < 0.05). The combination of elastase and cytomix reduced hydroxyproline content to 5.2% (P < 0.01). alpha(1)-Proteinase inhibitor blocked this synergy. Gelatin zymography and Western blot revealed that matrix metalloproteinase (MMP)-1, -3, and -9 were induced by cytomix and activated in the presence of elastase. Tissue inhibitor of metalloproteinase (TIMP)-1 and -2 were also induced by cytomix but were cleaved by elastase. We conclude that a synergistic interaction between cytomix and elastase, mediated through cytokine induction of MMP production and elastase-induced activation of latent MMPs and degradation of TIMPs, can result in a dramatic augmentation of collagen degradation. These findings support the notion that interaction among inflammatory mediators secreted by mononuclear cells and neutrophils can induce tissue cells to degrade extracellular matrix. Such a mechanism may contribute to the protease-anti-protease imbalance in emphysema.
Zhu
Y K
YK
Jincheng Hospital, Lanzhou 730050, China.
Liu
X D
XD
Sköld
C M
CM
Umino
T
T
Wang
H J
HJ
Spurzem
J R
JR
Kohyama
T
T
Ertl
R F
RF
Rennard
S I
SI
D000818:Animals; D002452:Cell Count; D018929:Cell Culture Techniques / Q000379:methods; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism* / Q000494:pharmacology; D004357:Drug Synergism; D004646:Emphysema / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D005782:Gels; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism / Q000494:pharmacology; D007375:Interleukin-1 / Q000378:metabolism / Q000494:pharmacology; D019272:Leukocyte Elastase / Q000378:metabolism* / Q000494:pharmacology; D008168:Lung / Q000166:cytology*; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism; D019278:Matrix Metalloproteinase 3 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051381:Rats; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism / Q000494:pharmacology
D016207:Cytokines; D005782:Gels; D007375:Interleukin-1; D019715:Tissue Inhibitor of Metalloproteinase-1; D014409:Tumor Necrosis Factor-alpha; D019716:Tissue Inhibitor of Metalloproteinase-2; D007371:Interferon-gamma; D003094:Collagen; D019272:Leukocyte Elastase; D019278:Matrix Metalloproteinase 3; D020780:Matrix Metalloproteinase 9; D020781:Matrix Metalloproteinase 1