title: Salicylate-based anti-inflammatory drugs inhibit the early lesion of diabetic retinopathy.
abstract: It has been previously reported that aspirin inhibited the development of diabetic retinopathy in diabetic animals, raising the possibility that anti-inflammatory drugs may have beneficial effects on diabetic retinopathy. To further explore this, we compared effects of oral consumption of three different salicylate-based drugs (aspirin, sodium salicylate, and sulfasalazine) on the development of early stages of diabetic retinopathy in rats. These three drugs differ in their ability to inhibit cyclooxygenase but share an ability to inhibit nuclear factor-kappaB (NF-kappaB). Diabetes of 9-10 months duration significantly increased the number of TUNEL (transferase-mediated dUTP nick-end labeling)-positive capillary cells and acellular (degenerate) capillaries in the retinal vasculature, and all three salicylate-based drugs inhibited this cell death and formation of acellular capillaries without altering the severity of hyperglycemia. In short-term diabetes (2-4 months), all three salicylates inhibited the diabetes-induced loss of neuronal cells from the ganglion cell layer. Oral aspirin (as a representative of the salicylate family) inhibited diabetes-induced increase in NF-kappaB DNA-binding affinity in electrophoretic mobility shift assay and transcription factor array in nuclear extract isolated from whole retina. All three salicylates inhibited the diabetes-induced translocation of p50 (a subunit of NF-kappaB) into nuclei of retinal vascular endothelial cells of the isolated retinal vasculature, as well as of p50 and p65 into nuclei of cells in the ganglion cell layer and inner nuclear layer on whole-retinal sections. Sulfasalazine (also as a representative of the salicylates) inhibited the diabetes-induced upregulation of several inflammatory gene products, which are regulated by NF-kappaB, including vascular cell adhesion molecule, intracellular adhesion molecule-1, inducible nitric oxide synthase, and cyclooxygenase-2 in whole-retinal lysate. Salicylates, in doses administrated in our experiments, inhibited NF-kappaB and perhaps other transcription factors in the retina, were well tolerated, and offered new tools to investigate and inhibit the development of diabetic retinopathy.
authors.affiliation: Department of Medicine and Ophthalmology, 434 Biomedical Research Building, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA.
authors.forename: Ling
authors.initials: L
authors.lastname: Zheng
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Howell
authors.forename: Denise A
authors.initials: DA
authors.lastname: Hatala
authors.forename: Kun
authors.initials: K
authors.lastname: Huang
authors.forename: Timothy S
authors.initials: TS
authors.lastname: Kern
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology / Q000627:therapeutic use*; D001241:Aspirin / Q000494:pharmacology / Q000627:therapeutic use; D016923:Cell Death / Q000187:drug effects; D003921:Diabetes Mellitus, Experimental / Q000473:pathology; D003930:Diabetic Retinopathy / Q000188:drug therapy* / Q000517:prevention & control; D007249:Inflammation / Q000473:pathology; D008297:Male; D016328:NF-kappa B / Q000187:drug effects* / Q000378:metabolism; D052002:NF-kappa B p50 Subunit / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D011897:Random Allocation; D051381:Rats; D011917:Rats, Inbred Lew; D012160:Retina / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D012165:Retinal Ganglion Cells / Q000187:drug effects*; D012459:Salicylates / Q000494:pharmacology / Q000627:therapeutic use*; D012980:Sodium Salicylate / Q000494:pharmacology / Q000627:therapeutic use; D012460:Sulfasalazine / Q000494:pharmacology / Q000627:therapeutic use; D051996:Transcription Factor RelA / Q000187:drug effects
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D016328:NF-kappa B; D052002:NF-kappa B p50 Subunit; D012459:Salicylates; D051996:Transcription Factor RelA; D012460:Sulfasalazine; D001241:Aspirin; D012980:Sodium Salicylate