title: Neutrophil Protease Cleavage of Von Willebrand Factor in Glomeruli - An Anti-thrombotic Mechanism in the Kidney.
abstract: Adequate cleavage of von Willebrand factor (VWF) prevents formation of thrombi. ADAMTS13 is the main VWF-cleaving protease and its deficiency results in development of thrombotic microangiopathy. Besides ADAMTS13 other proteases may also possess VWF-cleaving activity, but their physiological importance in preventing thrombus formation is unknown. This study investigated if, and which, proteases could cleave VWF in the glomerulus. The content of the glomerular basement membrane (GBM) was studied as a reflection of processes occurring in the subendothelial glomerular space. VWF was incubated with human GBMs and VWF cleavage was assessed by multimer structure analysis, immunoblotting and mass spectrometry. VWF was cleaved into the smallest multimers by the GBM, which contained ADAMTS13 as well as neutrophil proteases, elastase, proteinase 3 (PR3), cathepsin-G and matrix-metalloproteinase 9. The most potent components of the GBM capable of VWF cleavage were in the serine protease or metalloprotease category, but not ADAMTS13. Neutralization of neutrophil serine proteases inhibited GBM-mediated VWF-cleaving activity, demonstrating a marked contribution of elastase and/or PR3. VWF-platelet strings formed on the surface of primary glomerular endothelial cells, in a perfusion system, were cleaved by both elastase and the GBM, a process blocked by elastase inhibitor. Ultramorphological studies of the human kidney demonstrated neutrophils releasing elastase into the GBM. Neutrophil proteases may contribute to VWF cleavage within the subendothelium, adjacent to the GBM, and thus regulate thrombus size. This anti-thrombotic mechanism would protect the normal kidney during inflammation and could also explain why most patients with ADAMTS13 deficiency do not develop severe kidney failure.
authors.affiliation: Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden.
authors.forename: Ramesh
authors.initials: R
authors.lastname: Tati
authors.affiliation: Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden.
authors.forename: Ann-Charlotte
authors.initials: AC
authors.lastname: Kristoffersson
authors.affiliation: Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden.
authors.forename: Minola
authors.initials: M
authors.lastname: Manea Hedström
authors.affiliation: Department of Infection Medicine, Clinical Sciences Lund, Lund University, Lund, Sweden.
authors.forename: Matthias
authors.initials: M
authors.lastname: Mörgelin
authors.affiliation: Department of Nephrology, Clinical Sciences Lund, Lund University, Lund, Sweden.
authors.forename: Jörgen
authors.initials: J
authors.lastname: Wieslander
authors.affiliation: Department of Nephrology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Cees
authors.initials: C
authors.lastname: van Kooten
authors.affiliation: Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden. Electronic address: diana.karpman@med.lu.se.
authors.forename: Diana
authors.initials: D
authors.lastname: Karpman
mesh_terms: D000071120:ADAMTS13 Protein / Q000378:metabolism; D000328:Adult; D001792:Blood Platelets / Q000378:metabolism; D056649:Cathepsin G / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism; D050533:Glomerular Basement Membrane / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D007668:Kidney / Q000098:blood supply / Q000378:metabolism* / Q000648:ultrastructure; D007678:Kidney Glomerulus / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D019272:Leukocyte Elastase / Q000037:antagonists & inhibitors / Q000378:metabolism; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D053146:Myeloblastin / Q000378:metabolism; D009504:Neutrophils / Q000201:enzymology*; D010447:Peptide Hydrolases / Q000378:metabolism*; D053491:Proteinase Inhibitory Proteins, Secretory / Q000494:pharmacology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013927:Thrombosis / Q000378:metabolism* / Q000517:prevention & control; D014841:von Willebrand Factor / Q000378:metabolism*
chemical_list: D053491:Proteinase Inhibitory Proteins, Secretory; D014841:von Willebrand Factor; D010447:Peptide Hydrolases; D056649:Cathepsin G; D019272:Leukocyte Elastase; D053146:Myeloblastin; D020780:Matrix Metalloproteinase 9; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human
keywords: ADAMTS13; Elastase; Glomerular basement membrane; Kidney; Neutrophils; Von Willebrand factor