title: Macrophage matrix metalloproteinase-9 mediates epithelial-mesenchymal transition in vitro in murine renal tubular cells.
abstract: As a rich source of pro-fibrogenic growth factors and matrix metalloproteinases (MMPs), macrophages are well-placed to play an important role in renal fibrosis. However, the exact underlying mechanisms and the extent of macrophage involvement are unclear. Tubular cell epithelial-mesenchymal transition (EMT) is an important contributor to renal fibrosis and MMPs to induction of tubular cell EMT. The aim of this study was to investigate the contribution of macrophages and MMPs to induction of tubular cell EMT. The murine C1.1 tubular epithelial cell line and primary tubular epithelial cells were cultured in activated macrophage-conditioned medium (AMCM) derived from lipopolysaccharide-activated J774 macrophages. MMP-9, but not MMP-2 activity was detected in AMCM. AMCM-induced tubular cell EMT in C1.1 cells was inhibited by broad-spectrum MMP inhibitor (GM6001), MMP-2/9 inhibitor, and in AMCM after MMP-9 removal by monoclonal Ab against MMP-9. AMCM-induced EMT in primary tubular epithelial cells was inhibited by MMP-2/9 inhibitor. MMP-9 induced tubular cell EMT in both C1.1 cells and primary tubular epithelial cells. Furthermore, MMP-9 induced tubular cell EMT in C1.1 cells to an extent similar to transforming growth factor-beta. Transforming growth factor-beta-induced tubular cell EMT in C1.1 cells was inhibited by MMP-2/9 inhibitor. Our in vitro study provides evidence that MMPs, specifically MMP-9, secreted by effector macrophages can induce tubular cell EMT and thereby contribute to renal fibrosis.
authors.affiliation: Centre for Transplantation and Renal Research, the University of Sydney at Westmead Millennium Institute, Sydney, NSW 2145 Australia. ttan4526@mail.usyd.edu.au
authors.forename: Thian Kui
authors.initials: TK
authors.lastname: Tan
authors.forename: Guoping
authors.initials: G
authors.lastname: Zheng
authors.forename: Tzu-Ting
authors.initials: TT
authors.lastname: Hsu
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Vincent W S
authors.initials: VW
authors.lastname: Lee
authors.forename: Xinrui
authors.initials: X
authors.lastname: Tian
authors.forename: Yiping
authors.initials: Y
authors.lastname: Wang
authors.forename: Qi
authors.initials: Q
authors.lastname: Cao
authors.forename: Ya
authors.initials: Y
authors.lastname: Wang
authors.forename: David C H
authors.initials: DC
authors.lastname: Harris
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000494:pharmacology; D004151:Dipeptides / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology*; D004848:Epithelium / Q000201:enzymology* / Q000473:pathology; D005355:Fibrosis / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D007684:Kidney Tubules / Q000473:pathology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008262:Macrophage Activation / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors; D008648:Mesoderm / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D010641:Phenotype; D021381:Protein Transport / Q000187:drug effects; D011994:Recombinant Proteins / Q000494:pharmacology; D014517:Ureteral Obstruction / Q000201:enzymology / Q000473:pathology
chemical_list: D000199:Actins; D017077:Culture Media, Conditioned; D004151:Dipeptides; D036341:Intercellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides; D061965:Matrix Metalloproteinase Inhibitors; C078131:N-(2(R)-2-(hydroxamidocarbonylmethyl)-4-methylpentanoyl)-L-tryptophan methylamide; D011994:Recombinant Proteins; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9