American researchers have found that the protein, secretogranin III (Scg3), increases vascular leakage in mice.
The findings, published in The Journal of Experimental Medicine, suggest that inhibiting this molecule may help to prevent retinopathy in premature babies and diabetics.
When administered to mice, the protein was found to stimulate blood vessel growth in diabetic animals but not in healthy animals.
Scientists discovered that treating diabetic mice with Scg3-neutralising antibodies dramatically reduced the leakiness of their retinal blood vessels. This effect was also seen in mice with oxygen-induced retinopathy, an animal model used to test the effect of treatments on retinopathy of prematurity.
Researchers still need to confirm the role of Scg3 in humans. Because it is thought that the protein is not needed for normal vascular development, the likelihood of harmful side effects is minimised.
Another advantage of inhibiting the protein is that it would involve targeting a distinct signalling pathway. This means that antiScg3 therapies could be used in combination with VEGF inhibitors.