Abstract
Purpose :
Age-related macular degeneration (AMD) of the aging retina represents a complex pro-inflammatory degeneration involving multiple molecular-genetic signaling pathways and a progressive disintegration of the central visual field. Accompanying AMD are the temporal accumulation of amyloid-enriched retinal lesions known as drusen. Using high-integrity total RNA from different stages of AMD-retina and age- and gender-matched controls, RNA sequencing, Genechip- and LED Northern-based analyses and multiple miRNA-mRNA bioinformatics algorithms the purpose of these studies was (i) to quantify the expression levels of all 2,650 microRNA (miRNA) and 27,000 messenger RNA (mRNA) species in AMD; (ii) to analyze the magnitude and complexity of miRNA-mRNA interactions at different stages of AMD; and (iii) to analyze these effects on neurobiological signaling pathways in AMD that involve amyloidogenesis, innate-immune deficits and retinal inflammation.
Methods :
AMD and age- and gender-matched control tissues; immunocytochemistry, mRNA and miRNA arrays and bioinformatics algorithms, LED-Northern dot blot, RNA-sequencing, stabilized anti-miRNA, RPE cells, transgenic murine models for AMD (TgAMD); Western analysis.
Results :
We report for the first time the RNA oligonucleotide abundance, complexity and sequence of 9 miRNAs significantly-increased in AMD. Of particular interest is the NF-kB-regulated pro-inflammatory miRNA-146a involved in multiple aspects of AMD pathology. Bioinformatics, miRNA-mRNA complementarity, next-gen RNA sequencing and feature-alignment-analysis further indicate that these miRNAs have potential to interact with about ~1,809 target-mRNAs (about 6.7% of the genome) involved in the regulation and synchronization of amyloidogenesis (βAPP-associated integrated membrane proteins such as TSPAN-12), innate-immune deficits (including down-regulation of complement factor H) and retinal inflammation (including increases in COX-2 expression).
Conclusions :
Highly integrated pathogenic miRNA-mRNA signaling contributes to the development of the AMD process. Understanding of miRNA-mRNA-mediated mechanisms and their contribution to specific pathological pathways in the retina should contribute to a refinement in the pharmacological strategies and intervention treatments available for AMD in the elderly population.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.