title: Aldose reductase inhibition prevents endotoxin-induced inflammatory responses in retinal microglia.
abstract: OBJECTIVE
  Retinal microglia become activated in diabetes and produce pro-inflammatory molecules associated with changes in retinal vasculature and increased apoptosis of retinal neurons and glial cells. We sought to determine if the action of aldose reductase (AR), an enzyme linked to the pathogenesis of diabetic retinopathy, contributes to activation of microglial cells.
  
  
  METHODS
  Involvement of AR in the activation process was studied using primary cultures of retinal microglia (RMG) isolated from wild-type and AR-null mice, or in mouse macrophage cultures treated with either AR inhibitors or small interfering RNA (siRNA) directed to AR. Inflammatory cytokines were measured by ELISA. Cell migration was measured using a transwell assay. Gelatin zymography was used to detect active matrix metalloproteinase (MMP)-9, while RMG-induced apoptosis of adult retinal pigment epithelium (ARPE-19) cells was studied in a cell coculture system.
  
  
  RESULTS
  Aldose reductase inhibition or genetic deficiency substantially reduced lipopolysacharide (LPS)-induced cytokine secretion from macrophages and RMG. Aldose reductase inhibition or deficiency also reduced the activation of MMP-9 and attenuated LPS-induced cell migration. Additionally, blockade of AR by sorbinil or through genetic means caused a reduction in the ability of activated RMG to induce apoptosis of ARPE-19 cells.
  
  
  CONCLUSIONS
  These results demonstrate that the action of AR contributes to the activation of RMG. Inhibition of AR may be a therapeutic strategy to reduce inflammation associated with activation of RMG in disease.
authors.affiliation: Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States.
authors.forename: Kun-Che
authors.initials: KC
authors.lastname: Chang
authors.forename: Jessica
authors.initials: J
authors.lastname: Ponder
authors.forename: Daniel V
authors.initials: DV
authors.lastname: Labarbera
authors.forename: J Mark
authors.initials: JM
authors.lastname: Petrash
mesh_terms: D000449:Aldehyde Reductase / Q000037:antagonists & inhibitors* / Q000172:deficiency / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D015153:Blotting, Western; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D004731:Endotoxins / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D048289:Imidazolidines / Q000494:pharmacology; D008264:Macrophages / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D017628:Microglia / Q000201:enzymology*; D012160:Retina / Q000166:cytology / Q000201:enzymology*; D012164:Retinal Diseases / Q000201:enzymology* / Q000503:physiopathology
chemical_list: D016207:Cytokines; D004731:Endotoxins; D004791:Enzyme Inhibitors; D048289:Imidazolidines; D000449:Aldehyde Reductase; D020780:Matrix Metalloproteinase 9; C026411:sorbinil
keywords: LPS; MMP-9; aldose reductase; aldose reductase inhibitor; inflammation; migration; retinal microglia; β-glucogallin