Abstract 4121104: Fish Oil-Derived N-3 Very-Long-Chain Polyunsaturated Fatty Acids Improve Retinal Function in Aged Mice

Introduction: Epidemiological studies and clinical trials have revealed cardiometabolic benefits associated with dietary fish oil-derived omega-3 polyunsaturated fatty acids, particularly EPA and DHA. Omega-3 very-long-chain polyunsaturated fatty acids (VLCPUFA), synthesized in vivo by very-long-chain fatty acid elongase (ELOVL), e.g. ELOVL2 and 4, have recently garnered interest for their role in eye and cardiometabolic diseases. In our previous study, aging mice fed a VLCPUFA-rich diet for 8 weeks exhibited lowered plasma lipid levels, and repeated gavage of VLCPUFA in young mice resulted in improved retinal function. However, it is largely not known if VLCPUFA intake for a short term in aged mice would also improve retinal function and have beneficial effects in cardiometabolic risk factors. Hypothesis: We hypothesized that VLCPUFA may delay or rescue age-related vision loss by supplementing the products of ELOVL2, which decrease in quantity with age. We also hypothesize that short-term VLCPUFA intake may also confer favorable cardiometabolic benefits. Aims: We aimed to evaluate the effects of exogenous VLCPUFA on visual function and lipoprotein profiles in aged mice. Methods: Sixteen-month-old mice received a daily oral gavage of C24-28-rich VLCPUFA-oil (80 mg/kg BW) or an Intralipid vehicle for 15 consecutive days (n=8). The electroretinogram (ERG) instrument used was a UTAS E-3000 with gold corneal and stainless-steel scalp electrodes. Fast Protein Liquid Chromatography was performed using pooled plasma. Results: Consumption of VLCPUFA for 15 days increased scotopic a- (p < 0.05 at −5, 0, 5, 10, and 15 dB) and b-wave (p < 0.05 at 0 and 5 dB, p = 0.08 at 10 dB) amplitudes on ERG in both male and female mice compared with control. Although photopic ERG results did not exhibit statistically significant differences, likely due to low sample size, the overall results were consistent with those in our previous studies in young mice. We report no statistically significant difference in the composition of pro-atherogenic VLDL and LDL fractions due to VLCPUFA gavage. Increasing the duration and samples size in future gavage studies may be critical to determine the effects of VLCPUFA on eye and cardiovascular risk factors. Conclusions: This study revealed that a short-term oral administration of VLCPUFA was effective in improving ERG response overall, but not lipoprotein profiles.