Neuronal and vascular retinal dysfunction on the stages of disease progression in a new experimental model of metabolic syndrome

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

Montreal

Congreso; ISN/ASN 2019 Annual Meeting (International Society of Neurochemistry and the American Society of Neurochemistry; 2019

ISN/ASN 2019 Annual Meeting (International Society of Neurochemistry and the American Society of Neurochemistry

YIC01-01NEURONAL AND VASCULAR RETINAL DYSFUNCTION ON THE STAGES OF DISEASE PROGRESSION IN A NEW EXPERIMENTAL MODEL OF METABOLIC SYNDROMEPablo BarcelonaCIBICI CONICET, Department of Clinical Biochemistry, School of Chemical Sciences, UNC, Córdoba, Argentina 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 (p Conclusion: 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