BASIC SCIENCE IL-2 and IFN-gamma in the retina of diabetic rats Siv Johnsen-Soriano & María Sancho-Tello & Emma Arnal & Amparo Navea & Enrique Cervera & Francisco Bosch-Morell & Maria Miranda & Francisco Javier Romero Received: 15 May 2009 / Revised: 30 November 2009 / Accepted: 20 December 2009 / Published online: 6 March 2010 # Springer-Verlag 2010 Abstract Background The pathophysiology of the early events leading to diabetic retinopathy is not fully understood. It has been suggested that Inflammatory processes are involved in the development of the disease; however, the concentrations of tissue retinal inflammatory mediators and their possible alteration in diabetic retinopathy have not been described. The aim of this work was to study T-helper cell cytokine and chemokine profiles, and tyrosine nitration in retinal tissue of diabetic rats. Methods Cytokines (interleukin IL-1a, IL-1b, IL-2, IL-4, IL-6, IL-10, TNFa, GM-CSF, IFN-g), chemokines (MIP-1a, MIP-2, MIP-3a, MCP-1, GRO/KC, RANTES, Fractalkine), and tyrosine nitration were measured in retinal homogenate obtained from Long–Evans rats after 5 months of experi- mental diabetes. Results The T-helper type 1 cytokines IL-2 and INF- gamma, in addition to NO production (measured as nitro- tyrosine), were found to be significantly elevated in diabetic rat retina homogenates. None of the other cytokines and chemokines studied were affected by the diabetic condition. Conclusions Immunoregulatory cytokines belonging to the Th-1 group (IL-2 and IFN-gamma) were increased in the retina of experimental diabetic rats. Moreover, the nitro- tyrosine formation (as an expression of increased NO production) was significantly elevated in the diabetic retina, supporting the concept of an inflammatory element in the development of diabetic retinopathy. Keywords Diabetic retinopathy . IL-2 . IFN-gamma . Chemokine . Cytokine Introduction Diabetic retinopathy is a progressive disease induced by chronic exposure to high blood glucose levels, e.g. hyperglycemia, and it is generally recognized as a vascular disease like many other diabetes-related alterations. Exten- sive research has been carried out in order to develop therapies for diabetic retinopathy; however, the pathogene- sis of diabetic retinopathy has not been clearly elucidated due to the complicated and intricate biochemical and pathophysiological aspects of the disease. In addition to metabolic control, current therapy for diabetic retinopathy A financial relationship with the Conselleria de Educación exists in form of a Grant. The authors have full control of all primary data, and we agree to allow Graefe’ s Archive for Clinical and Experimental Ophthalmology to review our data upon request. S. Johnsen-Soriano : M. Sancho-Tello : E. Arnal : A. Navea : F. Bosch-Morell : F. Javier Romero (*) Fundación Oftalmológica del Mediterráneo (FOM), Bifurcación Pio Baroja-General Avilés, s/n 46015 Valencia, Spain e-mail: jromero@uch.ceu.es S. Johnsen-Soriano : F. Bosch-Morell : M. Miranda : F. Javier Romero Departamento de Fisiología, Farmacología y Toxicología, Universidad CEU-Cardenal Herrera, Avda Seminario s/n, Moncada, 46113 Valencia, Spain M. Sancho-Tello Departamento de Patología, Facultad de Medicina y Odontología, Universidad de Valencia, Avda. Blasco Ibañez 15, 46010 Valencia, Spain E. Cervera Servicio de Oftalmología, Hospital General Universitario, 46015 Valencia, Spain Graefes Arch Clin Exp Ophthalmol (2010) 248:985–990 DOI 10.1007/s00417-009-1289-x