Scientists Recognize a Protein With Key Role in Diabetic Blindness

By NaDica | Articles

Oct 30

Diabetic retinopathy is a diabetes complication which impacts the eyes. Diabetic retinopathy occurs due to damage to the blood vessels of the tissue which is sensitive to light in the retina (back of the eye).

At first, it might cause mild vision issues or no symptoms. Eventually, it might lead to blindness.

This condition may develop in anyone with type 1 or type 2 diabetes. The longer individuals have diabetes, and the less controlled their blood glucose is, the more likely they are to have this eye complication.

Symptoms

Some of the symptoms of diabetic retinopathy might include:

  • Vision loss
  • Dark strings or spots floating in the vision
  • Empty or dark areas in the vision
  • Blurred vision
  • Impaired color vision
  • Fluctuating vision

Study

On this topic, there are a lot of studies. The most recent one is published in the Journal of Clinical Investigation. In this study, the researchers from the Utah Health University found a protein (ARF6) which when inhibited lowers diabetic retinopathy.

The results from this study provide an opportunity for new treatments of this eye disorder. According to the Weiguan Zhu, the co-first author, research assistant professor at U Health, the collaborators identified a compound (NAV-2729).

This compound inhibits ARF6, that is vital for diabetic retinopathy and its development. Studies are done in rodents treated in order to stimulate that particular condition.

By injecting the compound mentioned above in the eyes of the rodents, overgrowth of blood vessels and vessel leakage were notably reduced.

The long-term effects of this treatment remain unknown. When it comes to that, it remains to determine whether this drug will be proper for people.

According to the head of translational medicine, vice president, Dean Li says that ARF6 organizes multiple inflammatory signals which lead to inflammation common in many diseases such as diabetic eye disease.

ARF6 maintains the signal protein VEGF. It stimulates series of cascading responses which leads to a certain diseased state in the eyes.

New Treatments Are Necessary

Today the patients that have this condition may receive anti-VEGF injections once per month into the eyes to lower inflammation . This treatment is successful in around 40 % of the patients.

In this study, the NAV-2729 injections into the rodents were more efficient in lowering blood vessel leakage in comparison to the anti-VEGF injections.

M. Elizabeth Hartnett, is a contributor to the study and professor in visual sciences and ophthalmology at Moran Eye Center. She notes that diabetic retinopathy might develop over time and lead to dramatic vision loss. This vision loss might not improve with glasses.

There is need of new treatments. It is like that since diabetic retinopathy is growing around the world. Also it is expected to increase even more in the following few decades.

Furthermore, according to this study, the scientists found 2 proteins ARNO ¾ and ¾ GEP100. These proteins play a vital role when it comes to the signaling process. The 2 proteins activate ARF6 at 2 different places in the cell in order to continue with the signaling cycle.

The corresponding author of this study is Shannon Odelberg. According to Odelberg these results are crucial since they found a mechanism, With this mechanism  ARF6 actually controls the VEGF receptor signaling.

And for that reason it might have broader implications to other diseases which involve activation of the VEGF receptor like cancer.

In fact, Odelberg notes that ARNO activates ARF6 that transfers the VEGF receptor in the cell and here the signal might be amplified.

GEP100 actually activates ARF6 in order to recycle the VEGF receptor, and bring it back to the cell to be more precise its outside. Here is where it might reactivate in order the signaling process to start again.

The signaling loop sets off disease simply by enlarging blood vessel leak and forming weak and new blood vessels.

Future Plans

The scientists plan to continue and explore more about ARF6 and its role in other inflammatory conditions. Moreover, NAV-2720 was recognized by A6.

This is a subsidiary company of Navigen Inc which is a development company whose scientists contributed to the study.

Zhu notes that the A6 researchers are going forward when it comes to the development of other different compounds, more suitable for new treatments.

This work got funds from the American Asthma Foundation, Burroughs Wellcome Fund, National Health Institutes, and Juvenile Diabetes Research Foundation.

In addition to Hartnett, Zhu, and Odelberg, contributors to the study are Zhengfu and Yi Huang at Sichuan Provincial People’s Hospital, China.

And Kirk Thomas, Dallas Shi, Diane Ward, Jacob Winter, Lisa Lesniewski, Bianca Rich, Amanda Jiang, Lise Sorensen, Jackson Richards, Helong Zhao, Jake Bergquist, Tara Mleynek, Jing Ling and Jae Hyuk Yoo at U of U Health.

Also, Alan Mueller, Zongzhong Tong, Kirill Ostanin and Christine Dunn. If you find this article useful, share it with your friends and family.