Matrix metalloproteinases induction by pseudomonal virulence factors and inflammatory cytokines in vitro.

Abstract

The pathogenesis of pseudomonal keratitis was investigated by focusing on induction and activation of matrix metalloproteinases (MMPs) by pseudomonal virulence factors and proinflammatory cytokines. Corneal lesions and MMP induction in vivo were evaluated in rabbit corneas infected with a clinical isolate of Pseudomonas aeruginosa. Effects of pseudomonal virulence factors [elastase, alkaline protease, exotoxin A and lipopolysaccharide (LPS)], tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta on MMP induction and activation were further examined in vitro in rabbit corneal fibroblasts (RCF) and human fibrosarcoma (HT1080) cells using reverse transcriptase-polymerase chain reaction (RT-PCR), zymography and immunoblotting. Corneal ulcers with typical ring abscesses were observed 12-24 h after infection, and MMPs, particularly MMP-9, were upregulated in infected corneas. Pseudomonal elastase caused the most extensive damage to both cell types. RCF treated with pseudomonal exoproteases or LPS expressed and secreted MMP-9. Exotoxin A had no effect on MMP expression. Both IL-1beta and TNF-alpha augmented MMP-9 expression in HT1080 cells. Pseudomonal elastase proteolytically activated MMP-2 and MMP-9 released from the cells. In conclusion, corneal destruction seen with P. aeruginosa infections may result from enhanced expression of MMPs by corneal stromal cells stimulated with pseudomonal exoproteases and proinflammatory cytokines and the proteolytic activation of MMPs by pseudomonal elastase.

• Authors: S Miyajima, T Akaike, K Matsumoto, T Okamoto, J Yoshitake, K Hayashida, A Negi, H Maeda
• Journal: Microbial pathogenesis (Microb Pathog) Vol. 31 Issue 6 Pg. 271-81 (Dec 2001) ISSN: 0882-4010 [Print] England
• PMID: 11747375 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright 2001 Academic Press.

Chemical References

• AprE protein, Bacteria
• Bacterial Proteins
• Bacterial Toxins
• Cytokines
• Exotoxins
• Lipopolysaccharides
• Membrane Transport Proteins
• Virulence Factors
• ADP Ribose Transferases
• Pseudomonas aeruginosa exotoxin A
• Matrix Metalloproteinases
• Metalloendopeptidases
• pseudolysin, Pseudomonas aeruginosa

Topics

• ADP Ribose Transferases
• Animals
• Bacterial Proteins (pharmacology)
• Bacterial Toxins
• Cells, Cultured
• Cornea (cytology, metabolism)
• Corneal Ulcer (enzymology, microbiology)
• Cytokines (pharmacology)
• Exotoxins (pharmacology)
• Humans
• Immunoblotting
• Keratitis (etiology)
• Lipopolysaccharides (pharmacology)
• Matrix Metalloproteinases (biosynthesis, isolation & purification)
• Membrane Transport Proteins
• Metalloendopeptidases (pharmacology)
• Pseudomonas Infections (etiology)
• Pseudomonas aeruginosa (pathogenicity)
• Rabbits
• Reverse Transcriptase Polymerase Chain Reaction
• Virulence (physiology)
• Virulence Factors