title: Activation of MMP-9 by human lung epithelial cells in response to the cystic fibrosis-associated pathogen Burkholderia cenocepacia reduced wound healing in vitro.
abstract: Burkholderia cepacia complex is a group of bacterial pathogens that cause opportunistic infections in cystic fibrosis (CF). The most virulent of these is Burkholderia cenocepacia. Matrix metalloproteinases (MMPs) are upregulated in CF patients. The aim of this work was to examine the role of MMPs in the pathogenesis of B. cepacia complex, which has not been explored to date. Real-time PCR analysis showed that B. cenocepacia infection upregulated MMP-2 and MMP-9 genes in the CF lung cell line CFBE41o- within 1 h, whereas MMP-2, -7, and -9 genes were upregulated in the non-CF lung cell line 16HBE14o-. Conditioned media from both cell lines showed increased MMP-9 activation following B. cenocepacia infection. Conditioned media from B. cenocepacia-infected cells significantly reduced the rate of wound healing in confluent lung epithelia (P < 0.05), in contrast to conditioned media from Pseudomonas aeruginosa-infected cells, which showed predominant MMP-2 activation. Treatment of control conditioned media from both cell lines with the MMP activator 4-aminophenylmercuric acetate (APMA) also resulted in clear activation of MMP-9 and to a much lesser extent MMP-2. APMA treatment of control media also delayed the repair of wound healing in confluent epithelial cells. Furthermore, specific inhibition of MMP-9 in medium from cells exposed to B. cenocepacia completely reversed the delay in wound repair. These data suggest that MMP-9 plays a role in the reduced epithelial repair observed in response to B. cenocepacia infection and that its activation following B. cenocepacia infection contributes to the pathogenesis of this virulent pathogen.
authors: Centre of Microbial Host Interactions, Institute of Technology Tallaght, Dublin, Ireland.
authors: Ciara
authors: C
authors: Wright
authors: Ruth
authors: R
authors: Pilkington
authors: Máire
authors: M
authors: Callaghan
authors: Siobhán
authors: S
authors: McClean
mesh_terms: D019121:Burkholderia Infections / Q000150:complications / Q000201:enzymology* / Q000382:microbiology / Q000473:pathology; D057508:Burkholderia cenocepacia / Q000254:growth & development; D002460:Cell Line; D017077:Culture Media, Conditioned / Q000737:chemistry / Q000494:pharmacology*; D003550:Cystic Fibrosis / Q000150:complications / Q000201:enzymology* / Q000382:microbiology / Q000473:pathology; D018076:DNA, Complementary; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects*; D015870:Gene Expression; D006801:Humans; D008168:Lung / Q000201:enzymology* / Q000382:microbiology / Q000473:pathology; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D020783:Matrix Metalloproteinase 7 / Q000235:genetics / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors; D010662:Phenylmercuric Acetate / Q000031:analogs & derivatives / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D011480:Protease Inhibitors / Q000494:pharmacology; D011552:Pseudomonas Infections / Q000201:enzymology / Q000382:microbiology / Q000473:pathology; D011550:Pseudomonas aeruginosa / Q000254:growth & development; D015854:Up-Regulation; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D017077:Culture Media, Conditioned; D018076:DNA, Complementary; D061965:Matrix Metalloproteinase Inhibitors; D011480:Protease Inhibitors; C010024:4-aminophenylmercuriacetate; C060932:MMP7 protein, human; D020783:Matrix Metalloproteinase 7; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D010662:Phenylmercuric Acetate