title: Aldose Reductase Mediates Transforming Growth Factor β2 (TGF-β2)-Induced Migration and Epithelial-To-Mesenchymal Transition of Lens-Derived Epithelial Cells.
abstract: OBJECTIVE
  Cataract surgery involves removal of lens tissue, but is associated with a high complication rate due to regrowth of residual lens epithelial cells to produce posterior capsule opacification (PCO) and diminished visual acuity. As inhibitors of aldose reductase (AR) have been shown to suppress markers of PCO, our studies were designed to identify a role for AR in the pathogenesis of PCO.
  
  
  METHODS
  Sorbinil-mediated AR inhibition was determined by measuring sorbitol accumulation. Cell migration was measured using both transwell and scratch assays. Proteins in the SMAD signaling pathway were measured by Western blotting. The interactions of AR and SMADs were demonstrated by co-immunoprecipitation (Co-IP) and proximity ligation assay (PLA). Epithelial-to-mesenchymal transition (EMT) expression was measured by Western blot and quantitative PCR (q-PCR). Matrix metalloproteinase (MMP)-2 and MMP-9 activities were measured in conditioned medium by zymography.
  
  
  RESULTS
  We observed that either Sorbinil-mediated AR inhibition or siRNA-mediated AR gene knockdown prevented migration of lens epithelial cells following exposure to TGF-β2. AR inhibition or AR knockdown reduced SMAD and MMP activation triggered by TGF-β2. In addition, we demonstrated AR inhibition or AR knockdown decreased TGF-β2-induced expression of EMT markers. Co-IP studies and PLA were used to demonstrate that AR and SMAD2 interact either directly or in close concert with additional factor(s) in a nonenzymatic manner.
  
  
  CONCLUSIONS
  This study demonstrates that AR participates in the response of lens epithelial cells to TGF-β2. Our studies raise the possibility that AR inhibition may be effective in preventing development of PCO by disrupting the TGF-β2/SMAD pathway.
authors.affiliation: Department of Ophthalmology School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Anschutz.
authors.forename: Kun-Che
authors.initials: KC
authors.lastname: Chang
authors.affiliation: Department of Ophthalmology School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Anschutz.
authors.forename: J Mark
authors.initials: JM
authors.lastname: Petrash
mesh_terms: D000449:Aldehyde Reductase / Q000494:pharmacology*; D000818:Animals; D015153:Blotting, Western; D058442:Capsule Opacification / Q000378:metabolism* / Q000473:pathology; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000378:metabolism* / Q000473:pathology; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D007903:Lens Capsule, Crystalline / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D015398:Signal Transduction / Q000187:drug effects; D053781:Transforming Growth Factor beta2 / Q000378:metabolism*
chemical_list: D053781:Transforming Growth Factor beta2; D000449:Aldehyde Reductase