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Assessment of Kidney Function in Mouse Models of Glomerular Disease
09:16

Assessment of Kidney Function in Mouse Models of Glomerular Disease

Published on: June 30, 2018

Expression of sialidase and dystroglycan in human glomerular diseases

Nils P J Vogtländer1, Johan van der Vlag, Marinka A H Bakker

  • 1Department of Nephrology, Nephrology Research Laboratory, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands.

Nephrology, Dialysis, Transplantation : Official Publication of the European Dialysis and Transplant Association - European Renal Association
|September 17, 2009
PubMed
Abstract

Insights

Glomerular sialidase expression increases in membranous glomerulopathy (MG), potentially causing charge loss in kidney filters. Dystroglycan expression does not reliably distinguish between minimal change nephropathy and focal segmental glomerulosclerosis.

Area of Science:

  • Nephrology
  • Glomerular Biology
  • Biochemistry

Background:

  • Alpha-dystroglycan (alpha-DG) is a key podocyte glycoprotein involved in glomerular filtration.
  • Previous studies suggested alpha-DG expression differences could distinguish minimal change nephropathy (MCN) from focal segmental glomerulosclerosis (FSGS).
  • Sialic acid, a component of alpha-DG, contributes to the glomerular filter's negative charge; exogenous sialidase causes podocyte damage.

Purpose of the Study:

  • To investigate endogenous glomerular sialidase expression in various kidney diseases.
  • To re-evaluate dystroglycan expression in these conditions.
  • To explore the role of sialidase in glomerular charge abnormalities.

Main Methods:

  • Immunofluorescence was used to assess glomerular alpha-DG and sialidase expression in kidney biopsies from patients with MCN, FSGS, lupus nephritis (LN), membranous glomerulopathy (MG), and normal kidney controls (NHK).
  • Urinary sialic acid levels were quantified using LC-tandem mass spectrometry.
  • Statistical analysis compared expression levels across disease groups.

Main Results:

  • Glomerular sialidase expression was significantly increased (3-fold) in membranous glomerulopathy (MG) compared to normal kidneys.
  • Elevated urinary sialic acid concentrations were observed in two MG patients.
  • No significant changes in alpha-dystroglycan (alpha-DG) expression were found across the studied glomerular diseases, including between MCN and FSGS.

Conclusions:

  • Increased endogenous glomerular sialidase in MG may contribute to the loss of negative charge in the glomerular filter.
  • Dystroglycan expression is not a reliable biomarker for differentiating between MCN and FSGS.
  • These findings highlight a potential role for sialidase in the pathogenesis of glomerular diseases like MG.

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