Characterization of glomerular extracellular matrix in IgA nephropathy by proteomic analysis of laser-captured microdissected glomeruli

BMC Nephrol. 2019 Nov 14;20(1):410. doi: 10.1186/s12882-019-1598-1.

Abstract

Background: IgA nephropathy (IgAN) involves mesangial matrix expansion, but the proteomic composition of this matrix is unknown. The present study aimed to characterize changes in extracellular matrix in IgAN.

Methods: In the present study we used mass spectrometry-based proteomics in order to quantitatively compare protein abundance between glomeruli of patients with IgAN (n = 25) and controls with normal biopsy findings (n = 15).

Results: Using a previously published paper by Lennon et al. and cross-referencing with the Matrisome database we identified 179 extracellular matrix proteins. In the comparison between IgAN and controls, IgAN glomeruli showed significantly higher abundance of extracellular matrix structural proteins (e.g periostin, vitronectin, and extracellular matrix protein 1) and extracellular matrix associated proteins (e.g. azurocidin, myeloperoxidase, neutrophil elastase, matrix metalloproteinase-9 and matrix metalloproteinase 2). Periostin (fold change 3.3) and azurocidin (3.0) had the strongest fold change between IgAN and controls; periostin was also higher in IgAN patients who progressed to ESRD as compared to patients who did not.

Conclusion: IgAN is associated with widespread changes of the glomerular extracellular matrix proteome. Proteins important in glomerular sclerosis or inflammation seem to be most strongly increased and periostin might be an important marker of glomerular damage in IgAN.

Keywords: ESRD; Glomerulonephritis; IgA nephropathy; Proteomics.

MeSH terms

  • Adult
  • Case-Control Studies
  • Cell Adhesion Molecules / analysis
  • Extracellular Matrix / chemistry*
  • Extracellular Matrix Proteins / analysis*
  • Female
  • Glomerular Basement Membrane / chemistry
  • Glomerular Filtration Rate
  • Glomerulonephritis, IGA* / physiopathology
  • Humans
  • Kidney / chemistry
  • Kidney Glomerulus / chemistry*
  • Kidney Glomerulus / surgery
  • Laser Capture Microdissection
  • Male
  • Proteomics / methods*
  • Tandem Mass Spectrometry

Substances

  • Cell Adhesion Molecules
  • Extracellular Matrix Proteins
  • POSTN protein, human