Study reveals new potential treatment for diabetic macular oedema

Scientists in the US say they have identified a new approach to treating diabetic macular oedema (DMO), a sight-threatening complication of diabetes.
Cleveland Clinic researcher Bela Anand-Apte, MD, PhD, and colleagues found that combining insulin treatment with inhibition of the epidermal growth factor (EGF) betacellulin could help prevent macular oedema in diabetic mice.
Working with collaborators at Case Western Reserve University and the University of Wisconsi, they used a mouse model for diabetes to look at betacellulin (BTC) produced in the pancreas by proliferating beta cells .
After treating the mice with insulin, they saw a rise in levels of a soluble form of betacellulin in the retina. Simply injecting BTC into the vitreous fluid of both hyperglycemic and normal mice also increased vascular permeability in the retina .
Following further investigatio, the researchers determined that insulin was disrupting tight junctions between retinal pigment cells (RPEs), the barrier layer wrapped around retinal nerves, by driving up BTC expression and production of a protein called ADAM10.
By blocking the production of BTC and ADAM10, they discovered these cell-cell tight junctions could be protected.
By using a BTC-targeted EGF inhibitor, the researchers prevented the “cross-talk” between insulin and BTC and managed to preserve the animals’ “vascular integrity”.
Dr. Anand-Apte explained that by substituting a BTC-targeted EGF inhibitor, they managed to prevent the “cross-talk” between BTC and insulin and preserve “vascular integrity” in the diabetic mice.
Speaking at the recent annual meeting of the American Society for Cell Biology, she said: “These studies suggest that a combinatorial treatment of insulin and EGF inhibition might be a useful therapeutic combination to prevent macular oedema, but needs to be determined in people with diabetes.”