Abstract
Purpose :
Diabetic retinopathy, the major ocular complication associated with diabetes, remains the primary cause of vision loss in the working age population. Using non-targeted transcriptome analysis approaches, several groups have identified specific regulatory pathways affected in diabetic rodents. Use of those animal models has yielded critical discoveries relative to the general changes affecting the retinal transcriptome, but those are limited by the absence of a macula and the limited difference of peripheral versus central retina in rodents. These limitations are critical as diabetic retinopathy is a regional disease that affects the retina heterogeneously, as demonstrated by macular edema, peripheral non-perfusion and regional loss of receptor fields in diabetic patients.
Methods :
Using non-fixed, freshly isolated retinal tissues from human donors, with and without diabetes and with or without retinopathy, we used RNA deep sequencing to assess the transcriptional changes affecting the retina. In this study, we independently analyzed the transcriptome of the macular, perimacular and peripheral regions of the retina (n=6 per tissue and per group) in order to identify the regional impact of diabetes. Results were validated by quantitative pcr analysis using the same samples (n=6) as well as an independent set of samples (n=12).
Results :
Over 800 genes were statistically significantly affected (p>0.05) with region specific patterns as a function of the disease state. Principal component analysis confirmed the clustering of the samples while pathway analysis using the GeneGo/MetaCore integrated software identified specific inflammatory, metabolic and neuroglial regulatory pathway. Using qRT-PCR, consistent significant alterations of the expression of genes associated with inflammation (including the alternative pathway of the complement) and neuroglial regulatory pathways (growth factor signaling) were dissected and demonstrated a regional alteration with a primary diabetes component in the central retina and a primary retinopathy component in the peripheral retina.
Conclusions :
This study offers the first regional analysis of the pathophysiological mechanisms of diabetic retinopathy with a high potential of identification of specific therapeutic targets including specific regulators of the inflammatory response and regulation of the neuroglial tissue homeostasis.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.