Blog
About

0
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found

      Acquired Loss of Erythrocyte Complement Receptor Type 1 in Patients with Diabetic Nephropathy Undergoing Hemodialysis

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Background: Complement receptor type 1 on erythrocytes (E-CR1) plays important roles not only in the regulation of complement activation, but also the clearance of immune complexes. Reduced E-CR1 was previously found in patients undergoing hemodialysis (HD). We investigated whether the E-CR1level in HD patients with diabetic nephropathy (DMN) is decreased. The levels of decay accelerating factor (DAF) and CD59 on erythrocytes (E) were also determined to ascertain whether the loss of CR1 is a specific phenomenon or other complement regulatory proteins are also affected. Methods: The levels of CR1, DAF, and CD59 on E were analyzed in 176 HD patients with DMN, 101 HD patients with non-diabetes mellitus renal diseases (non-DMN), and 108 healthy individuals. Hind III restriction fragment length polymorphism of intron 27 of the CR1 gene was analyzed. The serum-soluble CR1 levelwas measured by ELISA. Results: The E-CR1 level was significantly lower in the DMN group than the non-DMN group (p < 0.0001) and healthy individuals (p < 0.05). The E-CR1 level was significantly higher in the non-DMN group than in healthy individuals (p < 0.01). The levels of E-DAF and E-CD59 were significantly lower in the DMN group than non-DMN group (DAF, p < 0.01; CD59, p < 0.0001). Within each genotype of the CR1 gene, the E-CR1 level was significantly lower in the DMN group than in the non-DMN group and healthy individuals (non-DMN, p < 0.01; healthy individuals, p < 0.05). The serum-soluble CR1 level was significantly higher in the DMN group than non-DMN group and control group (p < 0.01 each). However, soluble CR1 did not correlate with E-CR1. Conclusion: Acquired loss of E-CR1 was found among HD patients with DMN. From the viewpoint of host defense, it may be a prognostic factor.

          Related collections

          Most cited references 23

          • Record: found
          • Abstract: found
          • Article: not found

          Complement Receptor 1/Cd35 Is a Receptor for Mannan-Binding Lectin

          Mannan-binding lectin (MBL), a member of the collectin family, is known to have opsonic function, although identification of its cellular receptor has been elusive. Complement C1q, which is homologous to MBL, binds to complement receptor 1 (CR1/CD35), and thus we investigated whether CR1 also functions as the MBL receptor. Radioiodinated MBL bound to recombinant soluble CR1 (sCR1) that had been immobilized on plastic with an apparent equilibrium dissociation constant of 5 nM. N-acetyl-d-glucosamine did not inhibit sCR1–MBL binding, indicating that the carbohydrate binding site of MBL is not involved in binding CR1. C1q inhibited MBL binding to immobilized sCR1, suggesting that MBL and C1q might bind to the same or adjacent sites on CR1. MBL binding to polymorphonuclear leukocytes (PMNs) was associated positively with changes in CR1 expression induced by phorbol myristate acetate. Finally, CR1 mediated the adhesion of human erythrocytes to immobilized MBL and functioned as a phagocytic receptor on PMNs for MBL–immunoglobulin G opsonized bacteria. Thus, MBL binds to both recombinant sCR1 and cellular CR1, which supports the role of CR1 as a cellular receptor for the collectin MBL.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Early complement activation and decreased levels of glycosylphosphatidylinositol-anchored complement inhibitors in human and experimental diabetic retinopathy.

            Diabetic retinal microangiopathy is characterized by increased permeability, leukostasis, microthrombosis, and apoptosis of capillary cells, all of which could be caused or compounded by activation of complement. In this study, we observed deposition of C5b-9, the terminal product of complement activation, in the wall of retinal vessels of human eye donors with 9 +/- 3 years of type 2 diabetes, but not in the vessels of age-matched nondiabetic donors. C5b-9 often colocalized with von Willebrand factor in luminal endothelium. C1q and C4, the complement components unique to the classical pathway, were not detected in the diabetic retinas, suggesting that C5b-9 was generated via the alternative pathway, the spontaneous activation of which is regulated by complement inhibitors. The diabetic donors showed a prominent reduction in the retinal levels of CD55 and CD59, the two complement inhibitors linked to the plasma membrane by glycosylphosphatidylinositol anchors, but not in the levels of transmembrane CD46. Similar complement activation in retinal vessels and selective reduction in the levels of retinal CD55 and CD59 were observed in rats with a 10-week duration of streptozotocin-induced diabetes. Thus, diabetes causes defective regulation of complement inhibitors and complement activation that precede most other manifestations of diabetic retinal microangiopathy. These are novel clues for probing how diabetes affects and damages vascular cells.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Identification of the membrane glycoprotein that is the C3b receptor of the human erythrocyte, polymorphonuclear leukocyte, B lymphocyte, and monocyte

               DT Fearon (1980)
              A human erythrocyte membrane glycoprotein of 205,000 mol wt (gp205) has been identified as the C3b receptor of the erythrocyte, polymorphonuclear leukocyte (PMN), B lymphocyte, and monocyte. Initially, gp205 was sought and characterized as a constituent of the human erythrocyte membrane that can impair activation of the alternative complement pathway by inducing loss of function of the properdin-stabilized amplification C3 convertase (C3b,Bb,P) through displacement of Bb from C3b and by promoting cleavage-inactivation of C3b by C3b inactivator. These inhibitory activities of gp205 suggested that this membrane glyeoprotein had an affinity for C3b and prompted an analysis of its possible identity as the C3b receptor of human peripheral blood cells. The F(ab’)2 fragment of rabbit IgG anti-gp205 inhibited the formation of rosettes with sheep EC3b of human erythroeytes, B lymphocytes, monocytes and PMN in a dose-response manner; the 50 percent inhibitory doses were 0.13/μg/ml, 0.90 μg/ml, 1.25 μg/ml, and 1.20 μg/ml of F(ab’)2, respectively. Anti-gp205 did not impair the formation of rosettes by monocytes and B lymphocytes with sheep EC3bi or with EC3d. Scatchard analysis of the number of specific (125)I-F(ab’)(2) anti-gp205 binding sites/cell revealed 950 sites/erythrocyte, 21,000 sites/cell of B lymphocyte preparation, 57,000 sites/PMN, and 48,000 sites/monocyte, indicating that the higher concentrations of antibody that had been required for inhibition of rosette formation by the nucleated cells reflected larger numbers of receptors on these cells. Direct evidence for the identity of gp205 as the C3b receptor of the four cell types was obtained when detergent-solubilized membrane proteins of the surface-radioiodinated cells were reacted with anti- gp205 and the immunoprecipitate was analyzed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. In each instance, the antigenic material reacting with anti-gp205 represented a single protein with an apparent 205,000 mol wt. Thus, gp205 is the C3b receptor of human erythrocytes, PMN, B lymphocytes, and monocytes.
                Bookmark

                Author and article information

                Journal
                NEE
                Nephron Exp Nephrol
                10.1159/issn.1660-2129
                Cardiorenal Medicine
                S. Karger AG
                1660-2129
                2006
                October 2006
                14 July 2006
                : 104
                : 3
                : e89-e95
                Affiliations
                aDivision of Nephrology, Department of Internal Medicine, Juntendo University School of Medicine, Tokyo, bKasukabe-Kisen Hospital, Saitama, and cFukushima Medical College, Fukushima, Japan
                Article
                94547 Nephron Exp Nephrol 2006;104:e89–e95
                10.1159/000094547
                16837818
                © 2006 S. Karger AG, Basel

                Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher. Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug. Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

                Page count
                Figures: 2, Tables: 2, References: 32, Pages: 1
                Product
                Self URI (application/pdf): https://www.karger.com/Article/Pdf/94547
                Categories
                Original Paper

                Comments

                Comment on this article