- Diabetic retinopathy is a very common diabetic related eye condition that leads to blindness.
- New study finds that increase in transforming growth factor beta (TGF-β) offers protection against progression of diabetic related retinopathy.
- Inhibiting the effects of TGF-β is more likely to accelerate retinopathy in diabetic patients.
A slight increase in transforming growth factor beta (TGF-β), which is present in preclinical animal models with diabetic eye disease, protects retinal blood vessels from damage.
Damage to the retinal blood vesseld, known as diabetic retinopathy occurs during the early stages of the disease.
‘Identifying drugs that could increase transforming growth factor beta (TGF-β) signaling could be a therapeutic target for preventing diabetic retinopathy.’
Diabetic retinopathy is the most common diabetic related eye disease and a leading cause of blindness in American adults.
Retina is the structure in the back of the eye that perceives light. Diabetic retinopathy occurs when blood vessels in the retina become damaged and leak fluid.
Fluid accumulation in the retina can lead to swelling at the center of the retina known macular edema.
Progression of this condition leads to blockage of the vessels become blocked which can no longer carry blood. Though new blood vessels grow on the surface of the retina, the over accumulation of fluid can lead to its leak or rupture, impairing vision.
The current treatment options for diabetic retinopathy include controlling blood glucose and blood pressure levels. The new vessels can be treated with laser techniques, but tit causes damage to the retina.
Increase in Transforming Growth Factor beta (TGF-β)
Previous study by researchers from the Schepens Eye Research Institute of Massachusetts Eye and Ear had found an increased level of TGF-β in retinal blood vessels of diabetics.
As a result, they investigated whether diabetic retinopathy was as a result of increased TGF-β.
So, in a diabetic rat model, they used a medication to block the increased TGF-β signaling.
The results showed that taking away the small increase in TGF-β resulted in damage to the retinal vessels in the diabetic rat.
This led the authors to conclude that TGF-β protects the retinal vessels, and that inhibiting its effects is more likely to accelerate retinopathy in diabetic patients.
The findings may help in developing targeted therapeutics that delay or prevent the onset of diabetic eye in patients.
"We found that increased TGF-β is really defending the vessels in the retina," said senior author Mara Lorenzi, M.D., recently retired senior scientist at Schepens Eye Research Institute of Mass. Eye and Ear and Professor of Ophthalmology at Harvard Medical School.
"When we took away the small increase in TGF-β, we saw significant damage to the retinal vessels in animals with diabetes. Based on this finding, we'd now like to know if a little extra TGF-β will help protect the retinal vessels in patients with diabetes." Lorenzi said.
The authors concluded:
- not to use therapy for diabetes to block TGF-β as it increases damage to the retinal vessels
- to identify drugs for upward modulation of TGF-β signaling in a very controlled fashion to prevent or delay diabetic retinopathy
"There is definitely room for intervening early to protect the retina from diabetes," said Dr. Lorenzi. "Our hope is that a good TGF-β response to diabetes may protect patients from developing diabetic retinopathy, and that our findings may inspire new approaches toward this objective."
The findings are published online in the American Journal of Pathology
- Mara Lorenzi et al. The Increased Transforming Growth Factor-β Signaling Induced by Diabetes Protects Retinal Vessels. American Journal of Pathology; (year) doi.org/10.1016/j.ajpath.2016.11.007