Glycogen Synthase kinase-3 Inhibition Attenuates Fibroblast Activation and Development of Fibrosis Following Renal Ischemia-Reperfusion in Mice

Dis Model Mech. 2015 Aug 1;8(8):931-40. doi: 10.1242/dmm.020511. Epub 2015 Jun 18.

Abstract

Glycogen synthase kinase-3β (GSK3β) is a serine/threonine protein kinase that plays an important role in renal tubular injury and regeneration in acute kidney injury. However, its role in the development of renal fibrosis, often a long-term consequence of acute kidney injury, is unknown. Using a mouse model of renal fibrosis induced by ischemia-reperfusion injury, we demonstrate increased GSK3β expression and activity in fibrotic kidneys, and its presence in myofibroblasts in addition to tubular epithelial cells. Pharmacological inhibition of GSK3 using TDZD-8 starting before or after ischemia-reperfusion significantly suppressed renal fibrosis by reducing the myofibroblast population, collagen-1 and fibronectin deposition, inflammatory cytokines, and macrophage infiltration. GSK3 inhibition in vivo reduced TGF-β1, SMAD3 activation and plasminogen activator inhibitor-1 levels. Consistently in vitro, TGF-β1 treatment increased GSK3β expression and GSK3 inhibition abolished TGF-β1-induced SMAD3 activation and α-smooth muscle actin (α-SMA) expression in cultured renal fibroblasts. Importantly, overexpression of constitutively active GSK3β stimulated α-SMA expression even in the absence of TGF-β1 treatment. These results suggest that TGF-β regulates GSK3β, which in turn is important for TGF-β-SMAD3 signaling and fibroblast-to-myofibroblast differentiation. Overall, these studies demonstrate that GSK3 could promote renal fibrosis by activation of TGF-β signaling and the use of GSK3 inhibitors might represent a novel therapeutic approach for progressive renal fibrosis that develops as a consequence of acute kidney injury.

Keywords: Fibrosis; Glycogen synthase kinase-3β; TGF-β1.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation / drug effects
  • Cell Line
  • Epithelial Cells / drug effects
  • Epithelial Cells / metabolism
  • Extracellular Matrix / drug effects
  • Extracellular Matrix / metabolism
  • Fibroblasts / drug effects
  • Fibroblasts / enzymology*
  • Fibroblasts / pathology*
  • Fibrosis
  • Glycogen Synthase Kinase 3 / antagonists & inhibitors*
  • Glycogen Synthase Kinase 3 / metabolism
  • Glycogen Synthase Kinase 3 beta
  • Inflammation Mediators / metabolism
  • Kidney / drug effects
  • Kidney / enzymology
  • Kidney / pathology*
  • Macrophages / drug effects
  • Macrophages / metabolism
  • Mice, Inbred C57BL
  • Myofibroblasts / drug effects
  • Myofibroblasts / metabolism
  • Myofibroblasts / pathology
  • Protein Kinase Inhibitors / pharmacology*
  • Protein Kinase Inhibitors / therapeutic use
  • Reperfusion Injury / drug therapy
  • Reperfusion Injury / enzymology*
  • Reperfusion Injury / pathology*
  • Signal Transduction / drug effects
  • Thiadiazoles / pharmacology
  • Thiadiazoles / therapeutic use
  • Transforming Growth Factor beta / metabolism
  • beta Catenin / metabolism

Substances

  • 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione
  • Inflammation Mediators
  • Protein Kinase Inhibitors
  • Thiadiazoles
  • Transforming Growth Factor beta
  • beta Catenin
  • Glycogen Synthase Kinase 3 beta
  • Gsk3b protein, mouse
  • Glycogen Synthase Kinase 3