NEURONAL FUNCTIONALITY AND VASCULAR INTEGRITY ALTERATION IN RETINA OF MOUSE METABOLIC SYNDROME MODEL TRIGGERED BY LONG TERM FRUCTOSE INTAKE.

PAZ MC; BARCELONA PF; SUBIRADA PV; RIDANO, ME; CASTRO, C; CHIABRANDO GA; SANCHEZ, MC

Carlos Paz

Congreso; SAN 2019 (XXXIV Congreso Anual de Sociedad Argentina de Investigación en Neurociencias.; 2019

Sociedad Argentina de Investigación en Neurociencias.

Background: Diabetic retinopathy (DR) is the most serious ocular complication associated with T2DM, which is a metabolic syndrome (MS), and one of the leading causes of secondary blindness. Although animal models of DR have helped to advance in the knowledge of this disease, these models have some limitations to reproduce completely the early stage where take place the beginning of the neuronal and vascular alteration.Objetive: Analyze in early stages of the MS, markers of retinal vascular integrity and neuronal functionality to explore details of the mechanisms of action that command this event.Materials and Methods: Animals, C57BL/6 (WT) and Apolipoprotein E knockout mice (ApoE-KO) either fed with a normal diet (ND) or a 10% w/v fructose diet (FD) in drinking water from 2 months of age. Time-dependent kinetic studies were done from 4 to 6 months of age analyzing lipid and glucose metabolic parameters, glucose tolerance test (GTT) and insulin tolerance test (ITT), Total, LDL and HDL Cholesterol, Triglycerides, among others. All groups animals (n=8 per group) for GTTs, were fasted 5 h prior to 2g/kg body weight IP injection of glucose or 0.75U/kg body weight IP of regular human insulin for ITTs. Blood samples were taken from the tail vein at time 0 before injection and at 0.5; 1 and 2 h after this. Retinal functionality was assessed by electroretinography (ERG) at 2, 3 and 4 month of treatment in mice fully dark-adapted overnight ( > 15 hours). The specify marker expression of retinal neuronal integrity or degenerative damage was evaluated by Western Blot. Retinal histology and immunofluorescence (IF) analysis were performed in flatmounts and cryosections, whereas vascular permeability and leakage were quantified by Evans Blue extravasations. GraphPad Prism program was employed for statistical analysis.Results: After 2 month of treatment, ApoE-KO FD mice showed, in addition to dyslipidemic profile, altered GTT and ITT as compared with the other groups. At this time, the ERG a- and b- wave did not show changes but the oscillatory potential (OPs) amplitudes were significantly decrease in retinas of these mice compared to ApoE-KO ND mice (pConclusion: The results showed that ApoE-KO mice after 2 months of taking fructose presented metabolic alterations mimicking some features of human MS at its initial stages of the DR. Thus, this model could offer the benefit to investigate DR at an early stage of the MS, where the beginning of neuronal and vascular retinal dysfunction take place. This represent a big opportunity to apply different therapeutic strategy at different time point to the traditional.