Cause of Macular Degeneration Discovered?

Researchers have discovered what they believe is the cause of macular degeneration.  Published in the online edition of Nature Medicine, researchers from the University of Utah have suggested that a cell surface protein called Roundabout (ROBO-4) may play a role in preventing the development of age-related macular degeneration.

According to the research there is a biological pathway that may block the development of abnormal blood vessels and leakage that is associated with wet macular degeneration.  This discovery may provide some insight into the cause of macular degeneration that could lead to alternative treatments for the eye disease.

The lead researchers Dr. Dean Li and Dr. Kang Zhang, the presence of this protein on blood vessels may provide clues as to what is causing macular degeneration.  The research team managed to mutate this protein gene in mice and then observed behaviour of cells in response to the growth factor VEGF in the presence and absence of its binding partner, another protein called SLIT2.

Normal VEGF is responsible for the growth of normal vascular materials.  It has also been shown to lead to the development of age-related macular degeneration.  “What we are saying is the cells of the blood vessels have a protein receptor, and this is called Robo4, and if you activate the Robo4 receptor by giving it a protein that binds to it, the blood vessel cells know the cells shouldn’t leak and grow,” Dr. Li stated.

This potential cause of macular degeneration and the presence of VEGF have been targeted by anti-VEGF drugs such as Avastin, Lucentis and Macugen.  These macular degeneration drugs target the production of VEGF.

This new discovery may not only unveil other potential causes of macular degeneration, but may also allow for the development of alternative drugs that may treat the eye disease.  Developing mechanisms to inhibit the role of VEGF in macular degeneration patients may prevent progression of the disease or lead to an eventual cure.