title: A disintegrin and metalloenzyme (ADAM) 17 activation is regulated by α5β1 integrin in kidney mesangial cells.
abstract: BACKGROUND
  The disintegrin and metalloenzyme ADAM17 participates in numerous inflammatory and proliferative diseases, and its pathophysiological role was implicated in kidney fibrosis, polycystic kidney disease and other chronic kidney diseases. At present, we have little understanding how the enzyme activity is regulated. In this study we wanted to characterize the role of α5β1 integrin in ADAM17 activity regulation during G protein-coupled receptor (GPCR) stimulation.
  
  
  RESULTS
  We showed previously that the profibrotic GPCR agonist serotonin (5-HT) induced kidney mesangial cell proliferation through ADAM17 activation and heparin-binding epidermal growth factor (HB-EGF) shedding. In the present studies we observed that in unstimulated mesangial cell lysates α5β1 integrin co-precipitated with ADAM17 and that 5-HT treatment of the cells induced dissociation of α5β1 integrin from ADAM17. Using fluorescence immunostaining and in situ proximity ligation assay, we identified the perinuclear region as the localization of the ADAM17/α5β1 integrin interaction. In cell-free assays, we showed that purified α5β1 integrin and β1 integrin dose-dependently bound to and inhibited activity of recombinant ADAM17. We provided evidence that the conformation of the integrin determines its ADAM17-binding ability. To study the effect of β1 integrin on ADAM17 sheddase activity, we employed alkaline phosphatase-tagged HB-EGF. Overexpression of β1 integrin lead to complete inhibition of 5-HT-induced HB-EGF shedding and silencing β1 integrin by siRNA significantly increased mesangial cells ADAM17 responsiveness to 5-HT.
  
  
  CONCLUSIONS
  Our data show for the first time that β1 integrin has an important physiological role in ADAM17 activity regulation. We suggest that regulating α5β1 integrin binding to ADAM17 could be an attractive therapeutic target in chronic kidney diseases.
authors.affiliation: Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America.
authors.forename: Pal
authors.initials: P
authors.lastname: Gooz
authors.forename: Yujing
authors.initials: Y
authors.lastname: Dang
authors.forename: Shigeki
authors.initials: S
authors.lastname: Higashiyama
authors.forename: Waleed O
authors.initials: WO
authors.lastname: Twal
authors.forename: Courtney J
authors.initials: CJ
authors.lastname: Haycraft
authors.forename: Monika
authors.initials: M
authors.lastname: Gooz
mesh_terms: D051722:ADAM Proteins / Q000378:metabolism*; D000072198:ADAM17 Protein; D000818:Animals; D002478:Cells, Cultured; D004789:Enzyme Activation; D066257:Heparin-binding EGF-like Growth Factor; D039081:Integrin alpha5beta1 / Q000378:metabolism*; D019012:Integrin beta1 / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D050527:Mesangial Cells / Q000201:enzymology* / Q000378:metabolism; D046912:Multiprotein Complexes / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D021381:Protein Transport; D051381:Rats; D017207:Rats, Sprague-Dawley; D043562:Receptors, G-Protein-Coupled / Q000819:agonists; D013876:Thiophenes / Q000494:pharmacology
chemical_list: C587885:Hbegf protein, rat; D066257:Heparin-binding EGF-like Growth Factor; D039081:Integrin alpha5beta1; D019012:Integrin beta1; D036341:Intercellular Signaling Peptides and Proteins; D046912:Multiprotein Complexes; D043562:Receptors, G-Protein-Coupled; D013876:Thiophenes; C055058:5-(3-hydroxybenzoyl)-2-thiophenesulfonamide; D051722:ADAM Proteins; D000072198:ADAM17 Protein; C000606464:Adam17 protein, rat