Angiopoietins modulate endothelial adaptation, glomerular and podocyte hypertrophy after uninephrectomy

PLoS One. 2013 Dec 18;8(12):e82592. doi: 10.1371/journal.pone.0082592. eCollection 2013.

Abstract

Glomerular capillary remodeling is an essential process in the development of glomerular hypertrophy. Angiopoietins, which are important regulators in angiogenesis, plays a role in the development of glomerulus during embryogenesis. Here, we evaluated the influence of angiopoietin on glomerular components and hypertrophy after uninephrectomy in adult male BALB/c mice. The actions of angiopoietin 1 or 2 were systemically antagonized by the subcutaneous administration of antagonists. We observed that the angiopoietin system was activated after uninephrectomy, and that the blockade of angiopoietin 1 or 2 decreased the activation of the angiopoietin receptor--tyrosine kinase with Ig and EGF homology domains-2--and attenuated the development of glomerular and podocyte hypertrophy. The increase in endothelial density staining (anti-CD31) following uninephrectomy was also reversed by angiopoietin 1 or 2 blockades. Glomerular basement thickness and foot process width were observed to decrease in the angiopoietin blockade groups. These changes were associated with the down regulation of the expression of genes for the glomerular matrix and basement membrane, including collagen type IV α1, collagen type IV α2, collagen type IV α5, and laminin α5. Thus, angiopoietin 1 or 2 may play an important role in the development of glomerular hypertrophy after uninephrectomy. A blockade of the angiopoietin system not only influenced the endothelium but also the podocyte, leading to diminished gene expression and morphological changes after uninephrectomy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiopoietin-1 / genetics
  • Angiopoietin-1 / metabolism*
  • Angiopoietins / genetics
  • Angiopoietins / metabolism*
  • Animals
  • Blotting, Western
  • Fluorescent Antibody Technique
  • Hypertrophy / metabolism*
  • Hypertrophy / pathology
  • Immunohistochemistry
  • Kidney Glomerulus / metabolism*
  • Kidney Glomerulus / pathology
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Nephrectomy
  • Podocytes / metabolism*
  • Podocytes / pathology
  • Real-Time Polymerase Chain Reaction

Substances

  • Angiopoietin-1
  • Angiopoietins
  • Angpt1 protein, mouse

Grants and funding

This study was supported by grant from the National Health Research Institute Taiwan (PS9505, NHRI-EX101-10125SC), grant from National Taiwan University Hospital (100N01), Ta-Tung Kidney Foundation, Mrs. Hsiu-Chin Lee Kidney Research Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.