Phenotypic Expression of ADAMTS13 in Glomerular Endothelial Cells

Abstract

BackgroundADAMTS13 is the physiological von Willebrand factor (VWF)-cleaving protease. The aim of this study was to examine ADAMTS13 expression in kidneys from ADAMTS13 wild-type (Adamts13+/+) and deficient (Adamts13−/−) mice and to investigate the expression pattern and bioactivity in human glomerular endothelial cells.Methodology/Principal FindingsImmunohistochemistry was performed on kidney sections from ADAMTS13 wild-type and ADAMTS13-deficient mice. Phenotypic differences were examined by ultramorphology. ADAMTS13 expression in human glomerular endothelial cells and dermal microvascular endothelial cells was investigated by real-time PCR, flow cytometry, immunofluorescence and immunoblotting. VWF cleavage was demonstrated by multimer structure analysis and immunoblotting. ADAMTS13 was demonstrated in glomerular endothelial cells in Adamts13+/+ mice but no staining was visible in tissue from Adamts13−/− mice. Thickening of glomerular capillaries with platelet deposition on the vessel wall was detected in Adamts13−/− mice. ADAMTS13 mRNA and protein were detected in both human endothelial cells and the protease was secreted. ADAMTS13 activity was demonstrated in glomerular endothelial cells as cleavage of VWF.Conclusions/SignificanceGlomerular endothelial cells express and secrete ADAMTS13. The proteolytic activity could have a protective effect preventing deposition of platelets along capillary lumina under the conditions of high shear stress present in glomerular capillaries.

Biomarkers of endothelial activation/dysfunction in infectious diseases

“…Once released, ADAMTS13 cleaves biologically active and prothrombotic ultra-large vWF multimers and inhibits thrombus formation 44 . ADAMTS13 has been shown, in animal models, to decline during systemic infection.…”

Role of calcium in regulating the intra- and extracellular cleavage of von Willebrand factor by the protease ADAMTS13

“…Under physiological conditions, VWF size is partly regulated by the constitutively active blood metalloprotease, a disintegrin and metalloprotease with thrombospondin type 1 motif 13 (ADAMTS13). [2][3][4] This protease is secreted into blood by hepatic stellate cells 3,5,6 and is also synthesized by ECs [7][8][9] and platelets. 10,11 ADAMTS13 cleaves the Tyr1605-Met1606 scissile bond located within the A2-domain of VWF (VWF-A2) that is exposed upon the application of fluid/hydrodynamic shear stress.…”

ADAMTS13 Retards Progression of Diabetic Nephropathy by Inhibiting Intrarenal Thrombosis in Mice

“…ULVWF multimers are not present in the plasma of healthy individuals because, upon release from platelets or endothelial cells, they are rapidly cleaved by the plasma protease ADAMTS13 (A Disintegrin And Metalloprotease with Thrombospondin type I repeats-13) into less active, smaller VWF multimers. ADAMTS13 is synthesized primarily by hepatic stellate cells 4, 5 and to a lesser extent by endothelial cells 6, 7 megakaryocytes, 8 and podocytes. 9 Deficiency of ADAMTS13 or very low levels of ADAMTS13 (<10%) increases plasma levels of ULVWF and causes thrombotic thrombocytopenic purpura (TTP), a disorder of thrombotic microangiopathy (TMA).…”