Sodium Salicylate Reduced Insulin Resistance in the Retina of a Type 2 Diabetic Rat Model

• Published in: PloS one Vol. 10; no. 4; p. e0125505
• Main Authors: Jiang, Youde, Thakran, Shalini, Bheemreddy, Rajini, Coppess, William, Walker, Robert J., Steinle, Jena J.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 14.04.2015; Public Library of Science (PLoS)
• Subjects: Animal models; Animals; Apoptosis; Caspase; Caspase 3 - analysis; Caspase-3; Cells, Cultured; Diabetes; Diabetes mellitus; Diabetes Mellitus, Type 2 - metabolism; Diabetes Mellitus, Type 2 - pathology; Diabetic retinopathy; Disease Models, Animal; Electroretinography; Endothelial cells; Endothelial Cells - cytology; Endothelial Cells - drug effects; Endothelial Cells - metabolism; Enzyme-Linked Immunosorbent Assay; Ependymoglial Cells - cytology; Ependymoglial Cells - drug effects; Ependymoglial Cells - metabolism; Glucose - pharmacology; Humans; I-kappa B Proteins - metabolism; Insulin; Insulin - metabolism; Insulin receptor substrate 1; Insulin Receptor Substrate Proteins - metabolism; Insulin Resistance; Intraocular Pressure - physiology; Lysates; Male; Markers; NF-KappaB Inhibitor alpha; Nonsteroidal anti-inflammatory agents; Obesity; Phosphorylation - drug effects; Rats; Rats, Inbred BB; Receptor, Insulin - metabolism; Retina; Retina - drug effects; Retina - metabolism; Retinopathy; Salicylic acid; Signal Transduction - drug effects; Signaling; Sodium; Sodium salicylate; Sodium Salicylate - pharmacology; Substrates; Suppressor of Cytokine Signaling 3 Protein; Suppressor of Cytokine Signaling Proteins - metabolism; Tumor Necrosis Factor-alpha - analysis; Tumor necrosis factor-α; Type 2 diabetes; Western blotting
• DOI: 10.1371/journal.pone.0125505
• ISSN: 1932-6203

Sodium salicylate has been reported to reduce markers of diabetic retinopathy in a type 1 rat model. Because rates of type 2 diabetes are on the rise, we wanted to determine whether salicylate could improve insulin resistance in a type 2 rat model, as well as improve retinal function. We treated lean and obese BBZDR/Wor type 2 diabetic rats with salicylate in their chow for 2 months. Prior to salicylate treatment, rats underwent an electroretinogram to measure retinal function. After 2 months of treatment, rats underwent an additional electroretinogram prior to sacrifice. In addition to the animal model, we also treated retinal endothelial cells (REC) and rat Müller cells with salicylate and performed the same analyses as done for the rat retinal lysates. To investigate the role of salicylate in insulin signaling, we measured TNFα and caspase 3 levels by ELISA, as well as performed Western blotting for insulin receptor substrate 1, insulin receptor, SOCS3, and pro- and anti-apoptotic markers. Data demonstrated that salicylate significantly improved retinal function, as well as reduced TNFα and SOCS3-induced insulin resistance in all samples. Overall, results suggest that salicylate is effective in reducing insulin resistance in the retina of type 2 diabetic rat models.