Knockdown of thioredoxin-interacting protein ameliorates high glucose-induced epithelial to mesenchymal transition in renal tubular epithelial cells

Cell Signal. 2013 Dec;25(12):2788-96. doi: 10.1016/j.cellsig.2013.09.009. Epub 2013 Sep 13.


Epithelial to mesenchymal transition (EMT) of tubular cells contributes to the renal accumulation of matrix protein that is associated with diabetic nephropathy. Both high glucose and transforming growth factor-β (TGF-β) are able to induce EMT in cell culture. In this study, we examined the role of the thioredoxin-interacting protein (TXNIP) on EMT induced by high glucose or TGF-β1 in HK-2 cells. EMT was assessed by the expression of α-smooth muscle actin (α-SMA) and E-cadherin and the induction of a myofibroblastic phenotype. High glucose (30mM) was shown to induce EMT at 72h. This was blocked by knockdown of TXNIP or antioxidant NAC. Meanwhile, we also found that knockdown of TXNIP or antioxidant NAC inhibited high glucose-induced generation of reactive oxygen species (ROS), phosphorylation of p38 MAPK and ERK1/2 and expression of TGF-β1. HK-2 cells that were exposed to TGF-β1 (4ng/ml) also underwent EMT. The expression of TXNIP gene and protein was increased in HK-2 cells treated with TGF-β1. Transfection with TXNIP shRNA was able to attenuate TGF-β1 induced-EMT. These results suggested that knockdown of TXNIP antagonized high glucose-induced EMT by inhibiting ROS production, activation of p38 MAPK and ERK1/2, and expression of TGF-β1, highlighting TXNIP as a potential therapy target for diabetic nephropathy.

Keywords: AGEs; Ang II; DN; Diabetic nephropathy; ECM; EMT; ERK; HG; MAPK; N-acetylcysteine; NAC; ROS; TBP-2; TGF-β; TGF-β1; TRX; TXNIP; VDUP-1; advanced glycation end products; angiotensin II; diabetic nephropathy; epithelial to mesenchymal transition; extracellular matrix; extracellular signal-regulated kinase; high glucose; mitogen-activated protein kinase; reactive oxygen species; thioredoxin; thioredoxin binding protein-2; thioredoxin-interacting protein; transforming growth factor-β; vitamin D3 up-regulated protein-1; α-SMA; α-smooth muscle actin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • Epithelial Cells / cytology
  • Epithelial Cells / metabolism*
  • Epithelial-Mesenchymal Transition*
  • Gene Knockdown Techniques*
  • Glucose / metabolism*
  • Humans
  • Kidney Tubules / cytology*
  • MAP Kinase Signaling System
  • Transforming Growth Factor beta / metabolism


  • Carrier Proteins
  • TXNIP protein, human
  • Transforming Growth Factor beta
  • Glucose