Localization and functional characterization of glycosaminoglycan domains in the normal human kidney as revealed by phage display-derived single chain antibodies.
Glycosaminoglycans (GAG) play an important role in renal homeostasis. They are strongly negatively charged polysaccharides that bind and modulate a myriad of proteins, including growth factors, cytokines, and enzymes. With the aid of specific phage display-derived antibodies, the distribution of heparan sulfate (HS) and chondroitin sulfate (CS) domains in the normal human kidney was studied. HS domains were specifically located in basement membranes and/or surfaces of renal cells and displayed a characteristic distribution over the nephron. A characteristic location in specific parts of the tubular system was also observed. CS showed mainly an interstitial location. Immunoelectron microscopy indicated specific ultrastructural location of domains. Only partial overlap with any of seven different proteoglycan core proteins was observed. Two HS domains, one highly sulfated (defined by antibody HS4C3) and one low sulfated (defined by antibody RB4Ea12), were studied for their cell biologic relevance with respect to the proliferative effect of FGF-2 on human mesangial cells in vitro. Fibroblast growth factor 2 (FGF-2) binding was HS dependent. Addition of purified HS4C3 antibody but not of the RB4Ea12 antibody counteracted the binding and the proliferative effect of FGF-2, indicating that the HS4C3 domain is involved in FGF-2 handling by mesangial cells. In conclusion, specific GAG domains are differentially distributed in the normal human kidney and are likely involved in binding of effector molecules such as FGF-2. The availability of tools to identify and study relevant GAG structures allows the development of glycomimetica to halt, for instance, mesangial proliferation and matrix production as seen in diabetic nephropathy.
Lensen
Joost F M
JF
Department of Biochemistry 194, Radboud University Nijmegen Medical Center, NCMLS, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
Rops
Angelique L W M M
AL
Wijnhoven
Tessa J M
TJ
Hafmans
Theo
T
Feitz
Wouter F J
WF
Oosterwijk
Egbert
E
Banas
Bernhard
B
Bindels
René J M
RJ
van den Heuvel
Lambert P W J
LP
van der Vlag
Johan
J
Berden
Jo H M
JH
van Kuppevelt
Toin H
TH
D000328:Adult; D000906:Antibodies / Q000235:genetics* / Q000276:immunology; D000918:Antibody Specificity; D002809:Chondroitin Sulfates / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D005920:Glomerular Mesangium / Q000378:metabolism* / Q000648:ultrastructure; D006025:Glycosaminoglycans / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism*; D006497:Heparan Sulfate / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D006801:Humans; D008297:Male; D008856:Microscopy, Fluorescence; D016253:Microscopy, Immunoelectron; D008875:Middle Aged; D019151:Peptide Library; D017434:Protein Structure, Tertiary
D000906:Antibodies; D002809:Chondroitin Sulfates; D016222:Fibroblast Growth Factor 2; D006025:Glycosaminoglycans; D006497:Heparan Sulfate; D019151:Peptide Library