Mutations in factor H reduce binding affinity to C3b and heparin and surface attachment to endothelial cells in hemolytic uremic syndrome
Tamara Manuelian, … , Giuseppe Remuzzi, Peter F. Zipfel
Tamara Manuelian, … , Giuseppe Remuzzi, Peter F. Zipfel
Published April 15, 2003
Citation Information: J Clin Invest. 2003;111(8):1181-1190. https://doi.org/10.1172/JCI16651.
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Article Nephrology

Mutations in factor H reduce binding affinity to C3b and heparin and surface attachment to endothelial cells in hemolytic uremic syndrome

Abstract

Hemolytic uremic syndrome (HUS) is a disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. Recent studies have identified a factor H–associated form of HUS, caused by gene mutations that cluster in the C-terminal region of the complement regulator factor H. Here we report how three mutations (E1172Stop, R1210C, and R1215G; each of the latter two identified in three independent cases from different, unrelated families) affect protein function. All three mutations cause reduced binding to the central complement component C3b/C3d to heparin, as well as to endothelial cells. These defective features of the mutant factor H proteins explain progression of endothelial cell and microvascular damage in factor H–associated genetic HUS and indicate a protective role of factor H for tissue integrity during thrombus formation.

Authors

Tamara Manuelian, Jens Hellwage, Seppo Meri, Jessica Caprioli, Marina Noris, Stefan Heinen, Mihaly Jozsi, Hartmut P.H. Neumann, Giuseppe Remuzzi, Peter F. Zipfel

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Binding of recombinant wild-type and mutant factor H proteins to HUVECs:...
Binding of recombinant wild-type and mutant factor H proteins to HUVECs: immunofluorescence. HUVECs cultivated in serum-free medium were incubated with cell culture supernatant containing the indicated recombinant proteins, i.e., the recombinant wild-type protein (FH 8-20; WT) (a), the R1210C mutant (i.e., FH 8-20/R1210C) (b), and the R1215G mutant (i.e., FH 8-20/R1215G) (c), and FH 8-11 (d) was used as a control. Unfixed cells were used directly for immunofluorescence analysis by staining with factor H antiserum in combination with an FITC-labeled secondary antiserum. The bars in the lower corner show the length of 20 μm.