sorbinil and Retinal-Diseases

Topics: Adult; Aldehyde Reductase; Aneurysm; Capillaries; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Edema; Humans; Imidazoles; Imidazolidines; Laser Therapy; Neovascularization, Pathologic; Retinal Diseases; Retinal Vessels; Sorbitol; Vitrectomy

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.. 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.. 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.. 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.

Topics: Aldehyde Reductase; Analysis of Variance; Animals; Apoptosis; Blotting, Western; Cell Movement; Cells, Cultured; Cytokines; Disease Models, Animal; Endotoxins; Enzyme Inhibitors; Enzyme-Linked Immunosorbent Assay; Imidazolidines; Macrophages; Matrix Metalloproteinase 9; Mice; Mice, Inbred BALB C; Microglia; Retina; Retinal Diseases

Normotensive and spontaneously hypertensive rats fed a 30% galactose diet until 15-21 months of age developed significant (P less than 0.05) retinal capillary basement membrane thickening, compared with animals fed a standard test diet. Animals on the high galactose diet containing 250 mg/kg of the aldose reductase inhibitor, Sorbinil, did not develop basement membrane thickening. No cytologic abnormalities of pericytes or endothelial cells were noted, and pericyte:endothelial cell nuclear ratios did not differ in the various experimental groups. This model reproduces a characteristic lesion of diabetes mellitus in non-diabetic animals, and should facilitate study of the biochemical mechanisms of basement membrane thickening.

Topics: Animals; Basement Membrane; Female; Galactose; Imidazoles; Imidazolidines; Rats; Rats, Inbred Strains; Retinal Diseases; Retinal Vessels