(Press-News.org) Contact information: Mika Ono
mikaono@scripps.edu
858-784-2052
Scripps Research Institute
New eye treatment effective in laboratory tests
Promising new approach may lead to treatments for common eye diseases like neovascular macular degeneration and diabetic retinopathy
	
LA JOLLA, CA – October 23, 2013 – A promising technique for treating human eye disease has proven effective in preclinical studies and may lead to new treatments to prevent blindness, according to experiments conducted at The Scripps Research Institute (TSRI) in La Jolla, California. 
	
The studies involved controlling the actions of microRNAs, tiny pieces of RNA that were once considered to be "junk" but are now known to fine-tune gene activation and expression. The researchers showed that treating mice with short RNA strands that precisely target and inhibit microRNAs ("antimicroRNAs") can stop the aberrant growth of blood vessels ("neovascularization"). 
	
It is this abnormal proliferation of vessels that exacerbates vision loss in neovascular eye diseases like "wet" macular degeneration and diabetic retinopathy, two of the leading causes of blindness.
	
Described in the cover story of the November issue of the Journal of Clinical Investigation, the microRNA treatments blocked aberrant vessel growth without damaging existing vasculature or neurons in three separate models of neovascular eye disease—a proof-of-principle that suggests future treatment based on the same approach may be effective in humans. 
	
"We believe that targeting and inhibiting the action of microRNAs involved could represent a novel and effective way to treat a broad range of neovascular eye diseases such as diabetic retinopathy, macular degeneration and macular telangiectasia," said TSRI Professor Martin Friedlander, MD, PhD, who was senior author of the study. "We are excited about this approach to halting abnormal blood vessel growth without inducing off-target side effects."
	
The work is the first published result of a five-year, $10.2 million grant awarded last year by the National Eye Institute of the National Institutes of Health. The grant aims to harness the potential of microRNAs to stop abnormal blood vessel sprouting in the back of the eye and prevent blindness.
	
Friedlander said that the researchers hope to advance this approach with clinical trials; a potential pharmaceutical partner is interested in partnering with them once the therapy is optimized for human use. Clinical trials may take several years, and any such treatment would have to prove safe and effective before it would be routinely available. 
	
"Are we ready to go to the clinic tomorrow?—no," said Friedlander. "But is this class of therapeutics 'druggable'—the answer is 'yes.'"
	
Diseases Tied to Protein Called VEGF
	
Many types of blindness can be tied directly to the abnormal growth of blood vessels in the back of the eye—the retina, a soft tissue already rich with vasculature and crowded with light-sensing cells that capture visual cues and send signals to the brain.
	
In diseases like "wet" macular degeneration and diabetic retinopathy, abnormal blood vessels proliferate under or on top of the retina, respectively, presumably in response to hypoxia, or low oxygen levels. While the precise cause of the hypoxia is not clear, in the case of macular degeneration it may be due to deposits of abnormal molecules leading to inflammation and neovascularization. In diabetic retinopathy, scientists believe that the vessels themselves function abnormally, leaking fluid and bleeding, leading to loss of vision and the growth of additional abnormal vessels. 
	
For many years, scientists have sought to address vision loss by stemming this sort of aberrant growth of blood vessels. In the last decade, much of the focus has been on a molecule found in the human body called VEGF (vascular endothelial growth factor). 
	
VEGF is central to many types of aberrant blood vessel growth. When the body senses too little oxygen, it produces VEGF, and when vessels in the eye sense the elevated levels of that molecule, they sprout new shoots. VEGF and other molecules that promote blood vessel growth activate Ras, a gene that has to be activated for blood vessel sprouting to occur. Stopping VEGF, scientists have thought, would be a viable way to prevent blindness in many people. 
	
The pharmaceutical industry has been hotly pursuing ways to block the action of VEGF in people at risk of blindness and for other diseases as well, including cancer. Tumors often overproduce VEGF to stimulate blood vessel growth within tumors so that their fast-dividing cells are kept supplied with oxygen and other nutrients. Several anti-VEGF drugs (such as Lucentis® (ranibizumab), Macugen (pegaptanib), Eylea® (aflibercept) and Avastin® (bevacizumab)) are already in use, and dozens more are in clinical trials against cancers and common eye disorders such as wet macular degeneration.
	
Blocking VEGF in eye diseases has proved to be complicated, however. In addition to stimulating the growth of new blood vessels and mediating vascular permeability, the molecule also plays a critical function in maintaining the health of nerve cells and blood vessels in the retina, so disabling it too much can create unintended consequences within the eye's delicate tissues. 
	
A New Approach
	
Last year, in another paper published in the Journal of Clinical Investigation, Friedlander and his colleagues showed that VEGF is critically important for maintaining healthy vision as well and that blocking it completely can kill the eye's light-sensing cells, actually causing severe vision loss. (Friedlander's lab has investigated a number of other, non-VEGF angiogenic pathways and has shown that combining antagonists of these pathways along with a VEGF antagonist can actually enhance anti-angiogenic activity when used as combination therapy.)
	
"Our collaborator, David Cheresh, and his lab observed that microRNAs could be used to target neovascularization at a point in the pathway 'downstream' of VEGF," said Peter Westenskow, PhD, a postdoctoral fellow at TSRI and first author of the new study.  "We have now shown that microRNAs can inhibit the actions of multiple pro-angiogenic compounds including, but not limited to, VEGF.  Blocking these 'downstream' targets would stop the aberrant blood vessel sprouting while maintaining the health of the normal blood vessels in the eye."
	
In the new study, the team focused on microRNA-132, blocking it in the eye and preventing Ras activation using a tiny 22-base anti-microRNA. This work was the first to test its effect for neovascular eye diseases, showing that the new approach inhibited angiogenesis in three different models of neovascular eye disease. 
	
The researchers believe this work is especially promising, as other anti-microRNA-based therapies for different diseases are already in clinical trials.
	
INFORMATION:
	
The article, "Ras pathway inhibition prevents neovascularization by repressing endothelial cell sprouting," by Peter D. Westenskow, Toshihide Kurihara, Edith Aguilar, Elizabeth L. Scheppke, Stacey K. Moreno, Valentina Marchetti, Iacovos P. Michael, Sudarshan Anand, Andras Nagy, David Cheresh and Martin Friedlander appears in the Journal of Clinical Investigation. See: http://www.jci.org/articles/view/70230 
	
This work was funded by the National Institutes of Health (grants EY022025-01, EY11254, CA50286, HL103956 and EY021416). Additional support was provided by the Lowy Medical Research Institute and via a fellowship from the Manpei Suzuki Diabetes Foundation and the Japan Society for the Promotion of Science Postdoctoral Fellowship for Research Abroad.
New eye treatment effective in laboratory tests
Promising new approach may lead to treatments for common eye diseases like neovascular macular degeneration and diabetic retinopathy
2013-10-23
ELSE PRESS RELEASES FROM THIS DATE:
Changes in epigenetic DNA functions reveal how diabetes predisposes individuals to Alzheimer's
2013-10-23
Changes in epigenetic DNA functions reveal how diabetes predisposes individuals to Alzheimer's
Mount Sinai researchers hope to exploit findings to develop novel preventive and treatment strategies for Alzheimer's disease
	New ...
Swiss private banking in clinch with high cost level
2013-10-23
Swiss private banking in clinch with high cost level
	For the international wealth management industry, 2012 was a more benign year than the harsh 2011. Due to favorable stock and bond markets the volumes of managed funds increased, though not returning to pre-crisis ...
The molecular clock of the common buzzard
2013-10-23
The molecular clock of the common buzzard
Bielefeld biologists reveal the influence of genes on dispersal behavior
  This news release is available in German.    	Be it hibernation or the routes of migratory birds: all animal behaviour that is subject to annual ...
Nanopore opens new cellular doorway for drug transport
2013-10-23
Nanopore opens new cellular doorway for drug transport
	A living cell is built with barriers to keep things out – and researchers are constantly trying to find ways to smuggle molecules in. Professor Giovanni Maglia (Biochemistry, Molecular and Structural ...
New software traces origins of genetic disorders 20 times more accurately
2013-10-23
New software traces origins of genetic disorders 20 times more accurately
	In a bioinformatics breakthrough, iMinds – STADIUS – KU Leuven researchers have successfully applied advanced artificial intelligence to enable the automated analysis of huge amounts of ...
Insights into how TB tricks the immune system could help combat the disease
2013-10-23
Insights into how TB tricks the immune system could help combat the disease
	Researchers have identified a potential way to manipulate the immune system to improve its ability to fight off tuberculosis (TB).
	TB is a major problem for both humans and ...
Communication with similar people stronger than believed
2013-10-23
Communication with similar people stronger than believed
	People's tendency to communicate with similar people is stronger than earlier believed, which restricts the flow of information and ideas in social networks. These are the findings that an Aalto University ...
People don't put a high value on climate protection
2013-10-23
People don't put a high value on climate protection
Without further incentives selfish behavior will continue to dominate
  This news release is available in German.    	People are bad at getting a grip on collective risks. Climate change is a good ...
Long-term memory helps chimpanzees in their search for food
2013-10-23
Long-term memory helps chimpanzees in their search for food
Searching for bountiful fruit crops in the rain forest, chimpanzees remember past feeding experiences
  This news release is available in German.    	Where do you go when the fruits in ...
Study finds natural compound can be used for 3-D printing of medical implants
2013-10-23
Study finds natural compound can be used for 3-D printing of medical implants
	Researchers from North Carolina State University, the University of North Carolina at Chapel Hill and Laser Zentrum Hannover have discovered that a naturally-occurring compound ...
LAST 30 PRESS RELEASES:
Yonsei University develops a new era of high-voltage solid-state batteries
Underweight and unbalanced: Gut microbial diversity in underweight Japanese women
Astringent, sharper mind: Flavanols trigger brain activity for memory and stress response
New editorial urges clinicians to address sex-based disparities in sepsis treatment
Researchers at MIT develop new nanoparticles that stimulate the immune system to attack ovarian tumors
Opening the door to a vaccine for multiple childhood infections
New clue to ALS and FTD: Faulty protein disrupts brain’s ‘brake’ system
Detailed map of US air-conditioning usage shows who can beat the heat — and who can’t
An electronic fiber for stretchable sensing
New image captures spooky bat signal in the sky
Cobalt single atom-phosphate functionalized reduced graphene oxide/perylenetetracarboxylic acid nanosheet heterojunctions for efficiently photocatalytic H2O2 production
World-first study shows Australian marsupials contaminated with harmful ‘forever chemicals’
Unlocking the brain’s hidden drainage system
Enhancing smoking cessation treatment for people living with HIV
Research spotlight: Mapping how gut neurons respond to bacteria, parasites and food allergy
Gordon and Betty Moore Foundation Experimental Physics Investigators awards to UCSB experimentalists opens the door to new insights and innovations
Meerkats get health benefit from mob membership
COVID-19 during pregnancy linked to higher risk of neurodevelopmental disorders in children
How a chorus of synchronized frequencies helps you digest your food
UAlbany researcher partners on $1.2 million NSF grant to explore tropical monsoon rainfall patterns
Checkup time for Fido? Wait might be longer in the country
Genetic variation impact scores: A new tool for earlier heart disease detection
The Lundquist Institute awarded $9 million to launch Community Center of Excellence for Regenerative Medicine
'Really bizarre and exciting': The quantum oscillations are coming from inside
Is AI becoming selfish?
New molten salt method gives old lithium batteries a second life
Leg, foot amputations increased 65% in Illinois hospitals between 2016-2023
Moffitt studies uncover complementary strategies to overcome resistance to KRAS G12Cinhibitors in lung cancer
National summit of experts charts unprecedented roadmap to reduce harms from firearms in new ways
Global environmental DNA (eDNA) surveys significantly expand known geographic and ecological niche ranges of marine fish, highlighting current biases in conservation and ecological modeling
[Press-News.org] New eye treatment effective in laboratory testsPromising new approach may lead to treatments for common eye diseases like neovascular macular degeneration and diabetic retinopathy