A protein in the eye has been identified as being capable, in high enough levels, of preventing diabetic retinopathy. The discovery paves the way for a new treatment that has the potential to reverse the condition’s progress.
The protein, named Retinol Binding Protein 3 (RBP3), was identified by researchers examining the eyes of patients who have had insulin-dependent diabetes for more than 50 years but avoided complications like nerve damage, kidney disease and eye disease.
Of the patients tracked in the Joslin Diabetes Center Medalist Study, 35% avoided retinopathy despite having elevated glucose levels.
RBP3, a protein made only in the eye, was found in elevated levels among protected eyes. Its capacity to prevent, and even reverse, diabetic retinopathy was verified in mouse models.
According to the research team, the protein appears to reduce the effects of high glucose levels by reducing the amount of glucose that enters several important retinal cells.
The team also discovered that diabetes appeared to reduce the expression of RBP3 in the retina, explaining the limits of its protective effect.
“If we could find out what’s causing the decrease of RBP3 in the retina in the first place, we could design some kind of treatment to maintain its production, allowing all diabetic patients to have an endogenous protection against eye disease,” Dr George King, chief scientific officer at Joslin Diabetes Center, said.
The team hopes that further research into the mechanisms behind RBP3’s preventative qualities could lead to the development of a treatment to fight early-stage diabetic retinopathy.
Additionally, there is hope the discovery could lead to a new screening tool. RBP3 is also found in the bloodstream in limited amounts, and King’s team have planned follow-up studies to determine if it correlates with the severity of retinopathy.
The team’s findings have been reported in the journal Science Translational Medicine.