Researchers Confirm Importance of a Growth Factor in Maintaining Retinal Blood Vessels

They reported in PLoS One that blocking TGF-beta led to loss of vision in mice.

The growth factor TGF-ß is essential to the health of blood vessels in the retina, scientists at Schepens Eye Research Institute have confirmed. They say that blocking it can cause retinal dysfunction.

Researchers have believed that communication between endothelial cells and pericytes in a capillary is necessary to maintain blood vessel structure and function. The team from Schepens Eye Research Institute, using tissue cultures, previously identified that this communication results in the production of the protein TGF-ß.

In the current study, which appears in the April 2 issue PLoS ONE, they wanted to confirm that finding in animals. They thus injected mice with a virus that produces large quantities of soluble endoglin, a protein that would circulate and then bind to and inhibit TGF-ß.

Blockade of TGF-ß signaling led to increased vascular and neural cell apoptosis in the retina, which was associated with decreased retinal function, as measured by electroretinogram. Perfusion of the inner retinal vasculature was impaired and was accompanied by defective autoregulation and loss of capillary integrity.

Blood was not moving efficiently through the smaller vessels into the retina tissue, and fluid was leaking out of the vessels. These defects led to the death of ganglion cells and a loss of visual function.

These findings are detailed in a paper titled “TGF-ß Is Required for Vascular Barrier Function, Endothelial Survival and Homeostasis of the Adult Microvasculature.” Future studies are aimed at exploring what other molecules are involved in maintaining healthy blood vessels and how these relate to the development of microvascular diseases.