New treatment for eye disease was developed by researchers at the Scripps Research Institute (TSRI) in La Jolla, California. The preclinical studies conducted so far showed promising results and researchers hope that in the future patients with macular degeneration and diabetic retinopathy will benefit from this new treatment.
The study results were published in the Journal of Clinical Investigation and showed that treatment with microRNAs can block aberrant growth of blood vessels without harming normal vasculature or neurons. TSRI Professor Martin Friedlander, MD, PhD, senior author of the study, stressed that they believe that inhibition of these microRNAs could represent a new and effective way to treat many neurovascular eye diseases such as macular degeneration, diabetic retinopathy or macular telangiectasia. Researchers are excited that this approach stops the growth of abnormal blood vessels without inducing side effects.
Macular degeneration is an eye disease that can lead to blindness due to aberrant growth of blood vessels. In fact, blindness is the final event in several eye diseases. In conditions such as ‘wet’ macular degeneration or diabetic retinopathy, due to hypoxia ( low oxygen ), abnormal blood vessels begin to proliferate. Nobody knows the exact cause of this but it seems that in macular degeneration hypoxia occurs due to inflammation and neovascularization. Regarding diabetic retinopathy, it is known that in diabetes the blood vessels are damaged and this leads,among other conditions, to nephropathy, that is kidney disease and retinopathy, or eye disease.
Researchers are trying for several years to prevent blindness that occurs in these patients by inhibiting the neovascularization. Lately, researchers have turned their attention to a molecule involved in angiogenesis called vascular endothelial growth factor ( VEGF ). This molecule is released in hypoxia and activates Ras, which is a gene involved in blood vessel growth. Researchers have thought that VEGF is a good target and the drugs that appeared (VEGF inhibitors, such as bevacizumab , aflibercept, etc. ) were used not only for eye diseases such as macular degeneration but also for the treatment of certain cancers.
However blocking VEGF in eye diseases has proved to be a little more complicated because this molecule, besides stimulating neovascularization has other functions such as maintaining good functioning of blood vessels and nerves in the retina. So inhibiting VEGF in eye diseases leads also to some adverse effects. Now researchers have been able to prove that aberrant growth of blood vessels can be stopped using microRNA ‘s. “We have now shown that microRNAs can inhibit the actions of multiple pro-angiogenic compounds including, but not limited to, VEGF”, said Peter Westenskow, PhD, a postdoctoral fellow at TSRI and first author of the new study.