MicroRNA as therapeutics for the treatment of retinal degenerations
The study of MicroRNAs (miRNAs) will provide a new avenue for drug discovery for diseases such as Age-Related Macular Degeneration (AMD), and have applications for other retinal diseases such as diabetic retinopathy, retinitis pigmentosa, retinoblastoma and other neurodegenerative diseases such as Parkinson’s and Alzheimer’s.
MiRNA are small non-coding RNA molecules that post transcriptionally regulate gene expression. While miRNAs were only identified in humans as recently as the turn of this century, some miRNA-based agents are already in phase 2 clinical trials. This rapid progress from discovery to drug development reflects the effectiveness of miRNAs as therapeutic targets.
However, relatively little research has been conducted in the retina on the therapeutic potential of these molecules. The eye has the advantage of being a closed compartment, where therapeutic constructs can be readily delivered to the vitreous with minimal damage to a neural target - the retina - and without complications of surgery. MiRNAs are abundant throughout the central nervous system (CNS), and so the retina (part of the CNS) is ideal for studying endogenous miRNA function as well as their potential as therapeutic targets. Furthermore, some retinal miRNA’s are known to be heavily involved in modulating expression of inflammatory signals, including several that feature prominently in neuroinflammation and AMD.
We have shown that miRNA are modulated in retinal degenerations, and have identified a number of candidate miRNAs involved in retinal inflammation. We have demonstrated that a particular miRNA, miR-124, is capable of slowing the progression of retinal degeneration, reducing retinal inflammation, increasing retinal function and slowing photoreceptor cell death. It is our belief that further researcher into these novel and unexplored molecues will provide novel therapeutics for the treatment of retinal degenerations and other neurodegenerative diseases.