Glomerular Endothelial Surface Layer Acts as a Barrier against Albumin Filtration

Glomerulus: hyaluronidase treated mouse(EM or RCM) Glomerulus: control mouse(EM or RCM)

23mM

23mM

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Virtual representation of bound endogenous albumin in murine glomeruli after chronic infusion (4 weeks) of active (left) and inactive (right) hyaluronidase. The entire glomerular section is shown by reflection contrast microscopy images (top), after staining for bound albumin using horse radish peroxidase (HRP) conjugated anti-mouse albumin antibody and diamino-benzidine (DAB). The reflection shown in the reflection contrast microscopy images (red) are correlated with the staining in the consecutive virtual transmission electron microscopy slides (dark black spots) (see enlargement of both slides).

  • [DOI] Ravelli Raimond B. G., Kalicharan Ruby D., Avramut M. Cristina, Sjollema Klaas A., Pronk Joachim W., Dijk Freark, Koster Abraham J., Visser Jeroen T. J., Faas Frank G. A., and Giepmans Ben N. G., “Destruction of Tissue, Cells and Organelles in Type 1 Diabetic Rats Presented at Macromolecular Resolution,” Sci. rep., vol. 3, 2013.
    [Bibtex]
    @article{scirep2013,
    author = "{Ravelli Raimond B. G.} and {Kalicharan Ruby D.} and {Avramut M. Cristina} and {Sjollema Klaas A.} and {Pronk Joachim W.} and {Dijk Freark} and {Koster Abraham J.} and {Visser Jeroen T. J.} and {Faas Frank G. A.} and {Giepmans Ben N. G.}",
    doi = "http://dx.doi.org/10.1038/srep01804 10.1038/srep01804",
    journal = "Sci. Rep.",
    month = "may",
    publisher = "Macmillan Publishers Limited. All rights reserved",
    title = "{Destruction of Tissue, Cells and Organelles in Type 1 Diabetic Rats Presented at Macromolecular Resolution}",
    volume = "3",
    year = "2013"
    }
  • E. H. Williams, P. Carpentier, and T. Misteli, “The jcb dataviewer scales up,” The journal of cell biology, vol. 198, iss. 3, pp. 271-272, 2012.
    [Bibtex]
    @article{williams2012jcb,
    title={The JCB DataViewer scales up},
    author={Williams, Elizabeth H and Carpentier, Pamela and Misteli, Tom},
    journal={The Journal of cell biology},
    volume={198},
    number={3},
    pages={271--272},
    year={2012},
    publisher={Rockefeller Univ Press}
    }
  • F. G. Faas, C. M. Avramut, B. M. van den Berg, M. A. Mommaas, A. J. Koster, and R. B. Ravelli, “Virtual nanoscopy: generation of ultra-large high resolution electron microscopy maps,” The journal of cell biology, vol. 198, iss. 3, pp. 457-469, 2012.
    [Bibtex]
    @article{faas2012virtual,
    title={Virtual nanoscopy: Generation of ultra-large high resolution electron microscopy maps},
    author={Faas, Frank GA and Avramut, M Cristina and van den Berg, Bernard M and Mommaas, A Mieke and Koster, Abraham J and Ravelli, Raimond BG},
    journal={The Journal of cell biology},
    volume={198},
    number={3},
    pages={457--469},
    year={2012},
    publisher={Rockefeller Univ Press}
    }
  • [DOI] M. J. C. Dane, B. M. van den Berg, C. M. Avramut, F. G. A. Faas, J. van der Vlag, A. L. W. M. M. Rops, R. B. G. Ravelli, B. J. Koster, A. J. van Zonneveld, H. Vink, and T. J. Rabelink, “Glomerular Endothelial Surface Layer Acts as a Barrier against Albumin Filtration,” The american journal of pathology, vol. 182, iss. 5, p. 1532–1540, 2013.
    [Bibtex]
    @article{Dane20131532,
    abstract = "Glomerular endothelium is highly fenestrated, and its contribution to glomerular barrier function is the subject of debate. In recent years, a polysaccharide-rich endothelial surface layer (ESL) has been postulated to act as a filtration barrier for large molecules, such as albumin. To test this hypothesis, we disturbed the \{ESL\} in C57Bl/6 mice using long-term hyaluronidase infusion for 4 weeks and monitored albumin passage using immunolabeling and correlative light-electron microscopy that allows for complete and integral assessment of glomerular albumin passage. \{ESL\} ultrastructure was visualized by transmission electron microscopy using cupromeronic blue and by localization of \{ESL\} binding lectins using confocal microscopy. We demonstrate that glomerular fenestrae are filled with dense negatively charged polysaccharide structures that are largely removed in the presence of circulating hyaluronidase, leaving the polysaccharide surfaces of other glomerular cells intact. Both retention of cationic ferritin in the glomerular basement membrane and systemic blood pressure were unaltered. Enzyme treatment, however, induced albumin passage across the endothelium in 90\% of glomeruli, whereas this could not be observed in controls. Yet, there was no net albuminuria due to binding and uptake of filtered albumin by the podocytes and parietal epithelium. \{ESL\} structure and function completely recovered within 4 weeks on cessation of hyaluronidase infusion. Thus, the polyanionic \{ESL\} component, hyaluronan, is a key component of the glomerular endothelial protein permeability barrier.",
    author = "Dane, Martijn J.C. and van den Berg, Bernard M. and Avramut, M. Cristina and Faas, Frank G.A. and van der Vlag, Johan and Rops, Angelique L.W.M.M. and Ravelli, Raimond B.G. and Koster, Bram J. and van Zonneveld, Anton Jan and Vink, Hans and Rabelink, Ton J.",
    doi = "10.1016/j.ajpath.2013.01.049",
    issn = "0002-9440",
    journal = "The American Journal of Pathology",
    note = "",
    number = "5",
    pages = "1532–1540",
    title = "{Glomerular Endothelial Surface Layer Acts as a Barrier against Albumin Filtration}",
    url = "http://www.sciencedirect.com/science/article/pii/S0002944013001375",
    volume = "182",
    year = "2013"
    }

abstract

Glomerular endothelium is highly fenestrated, and its contribution to glomerular barrier function is the subject of debate. In recent years, a polysaccharide-rich endothelial surface layer (ESL) has been postulated to act as a filtration barrier for large molecules, such as albumin. To test this hypothesis, we disturbed the ESL in C57Bl/6 mice using long-term hyaluronidase infusion for 4 weeks and monitored albumin passage using immunolabeling and correlative light-electron microscopy that allows for complete and integral assessment of glomerular albumin passage. ESL ultrastructure was visualized by transmission electron microscopy using cupromeronic blue and by localization of ESL binding lectins using confocal microscopy. We demonstrate that glomerular fenestrae are filled with dense negatively charged polysaccharide structures that are largely removed in the presence of circulating hyaluronidase, leaving the polysaccharide surfaces of other glomerular cells intact. Both retention of native ferritin [corrected] in the glomerular basement membrane and systemic blood pressure were unaltered. Enzyme treatment, however, induced albumin passage across the endothelium in 90% of glomeruli, whereas this could not be observed in controls. Yet, there was no net albuminuria due to binding and uptake of filtered albumin by the podocytes and parietal epithelium. ESL structure and function completely recovered within 4 weeks on cessation of hyaluronidase infusion. Thus, the polyanionic ESL component, hyaluronan, is a key component of the glomerular endothelial protein permeability barrier.