Study explains why diabetic retinopathy is difficult to treat

Damage to the retina due to diabetes can be ameliorated only partially, despite treatment with the standard drug metformin. Scientists of Helmholtz Zentrum München have discovered that metformin treatment normalizes the alterations induced by diabetes in only about half of the altered retinal proteins. The results of the study were published in the journal Diabetologia.

Retinal damage is one of the most common complications of , affecting about 90 percent of type 1 diabetics and 75 percent of type 2 diabetics. According to the World Health Organization (WHO), diabetic retinopathy is the leading cause of blindness in adults of working age, and its incidence is showing an upward trend.

The retina is the part of the eye that converts optical images into nerve signals, which are then transmitted to the brain where vision is interpreted. Numerous proteins and molecules are involved in the process of . Diabetic leads to impaired function of these proteins. Within the framework of research projects of the German Center for Diabetes Research (DZD), scientists of the Research Unit Protein Science (PROT) and the Institute of Experimental Genetics (IEG) at Helmholtz Zentrum München (HMGU) have now investigated how drug treatment affects these signal carriers. They compared the concentrations of proteins in the retinas of non-diabetic mice, of mice with type 2 diabetes without treatment and of type 2 diabetic mice that were treated with the standard drug metformin, which lowers and thus reduces diabetes complications. A total of 98 proteins were differentially abundant in the diabetic animals. About half of the proteins were normalized by treatment with metformin. The other proteins were unchanged, however, despite treatment and improved blood glucose levels. Among these was the VGLUT1, which is essential for signal transduction in specific nerve cells.

"Our results show that normalized blood glucose levels alone are not sufficient to fully treat ," said Dr. Alice Ly (PROT), lead author of the study. "In further studies we want to examine how different combination therapies affect the retinal proteins, in order to achieve a better understanding of the causes and treatment of this diabetes complication," added Dr. Stefanie Hauck (PROT).

The most common diseases in the population, such as type 2 diabetes, are the focus of research at Helmholtz Zentrum München. The aim is to develop new approaches to diagnosis, and prevention.

More information: Ly, A. et al. (2013), Retinal proteome alterations in a mouse model of type 2 diabetes, Diabetologia. DOI: 10.1007/s00125-013-3070-2

add to favorites email to friend print save as pdf

Related Stories

Diabetes drug may reduce brain damage after stroke

Dec 03, 2012

In a study in mice, scientists at Karolinska Institutet in Sweden have discovered a new potential therapy that may reduce brain damage following stroke in type 2 diabetic patients. The suggested drug is already approved for ...

Diabetes leading to blindness in many people

Nov 30, 2012

Diabetes is the leading cause of new cases of blindness among adults 20 to 74 years old. Dr. Michael Grodin, co-director of retinal services and director of clinical research at Katzen Eye Group, with locations around Baltimore, ...

Recommended for you

Shift work linked to heightened risk of type 2 diabetes

Jul 24, 2014

Shift work is linked to a heightened risk of developing type 2 diabetes, with the risk seemingly greatest among men and those working rotating shift patterns, indicates an analysis of the available evidence published online ...

Rosemary and oregano contain diabetes-fighting compounds

Jul 23, 2014

The popular culinary herbs oregano and rosemary are packed with healthful compounds, and now lab tests show they could work in much the same way as prescription anti-diabetic medication, scientists report. In their new study ...

User comments