The Notch pathway mediates the angiotensin II-induced synthesis of extracellular matrix components in podocytes

Int J Mol Med. 2015 Jul;36(1):294-300. doi: 10.3892/ijmm.2015.2193. Epub 2015 Apr 22.

Abstract

The Notch pathway is known to contribute to the development of glomerular disease. Angiotensin II (Ang II), an important member of the renin-angiotensin system, stimulates the accumulation of extracellular matrix components in glomerular disease; however, the exact mechanisms involved remain to be elucidated. In the present study, we aimed to investigate the effects of the Notch pathway on the synthesis of extracellular matrix components in Ang II-stimulated podocytes. Mouse podocytes were stimulated with Ang II (10-6 mol/l). The activation of the Notch pathway was inhibited by a vector carrying short hairpin RNA (shRNA) targeting Notch1 (sh-Notch1) or by γ-secretase inhibitor (GSI). The protein levels of Notch1, Notch intracellular domain 1 (NICD1), hairy and enhancer of split-1 (Hes1), matrix metalloproteinase (MMP)-2, MMP-9, transforming growth factor-β1 (TGF-β1), type IV collagen and laminin were determined by western blot analysis. The Notch1, Hes1, MMP-2, MMP-9, TGF-β1, type IV collagen and laminin mRNA levels were detected by RT-PCR. The MMP-2 and MMP-9 activity was measured using a cell active fluorescence assay kit. The levels of TGF-β1, type IV collagen and laminin were determined in the culture medium of the podocytes by enzyme-linked immunosorbent assay (ELISA). Our results revealed that Ang II upregulated Notch1, NICD1, Hes1, TGF-β1, type IV collagen and laminin expression and downregulated MMP-2 and MMP-9 expression in the cultured podocytes. The inhibition of the Notch pathway by sh-Notch1 or GSI increased MMP-2 and MMP-9 expression, decreased the TGF-β1 level and suppressed type IV collagen and laminin expression. The inhibition of the Notch pathway by sh-Notch1 or GSI also increased MMP-2 and MMP-9 activity, and decreased TGF-β1 levels, type IV collagen levels and laminin secretion. These findings indicate that the Notch pathway potentially mediates the Ang II-induced synthesis of extracellular matrix components in podocytes through the regulation of MMPs and TGF-β1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid Precursor Protein Secretases / antagonists & inhibitors
  • Angiotensin II / metabolism
  • Angiotensin II / pharmacology*
  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Cell Line
  • Collagen Type IV / metabolism
  • Enzyme Activation
  • Extracellular Matrix / metabolism
  • Extracellular Matrix Proteins / biosynthesis*
  • Homeodomain Proteins / metabolism
  • Kidney Glomerulus / physiopathology
  • Laminin / metabolism
  • Matrix Metalloproteinase 2 / metabolism
  • Matrix Metalloproteinase 9 / metabolism
  • Mice
  • Oligopeptides / pharmacology
  • Podocytes / cytology
  • Podocytes / metabolism*
  • RNA Interference
  • RNA, Messenger / genetics
  • RNA, Small Interfering
  • Receptor, Notch1 / genetics
  • Receptor, Notch1 / metabolism*
  • Transcription Factor HES-1
  • Transforming Growth Factor beta1 / metabolism*

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • Collagen Type IV
  • Extracellular Matrix Proteins
  • Hes1 protein, mouse
  • Homeodomain Proteins
  • Laminin
  • Notch1 protein, mouse
  • Oligopeptides
  • RNA, Messenger
  • RNA, Small Interfering
  • Receptor, Notch1
  • Transcription Factor HES-1
  • Transforming Growth Factor beta1
  • benzyloxycarbonyl-leucyl-leucyl-norleucinal
  • Angiotensin II
  • Amyloid Precursor Protein Secretases
  • Matrix Metalloproteinase 2
  • Mmp2 protein, mouse
  • Matrix Metalloproteinase 9
  • Mmp9 protein, mouse