Researchers believe that a
protein called angiopoeietin-like
4 (ANGPTL4) may play an important role in the development of diabetic
retinopathy. Therefore, directing drugs that could target this protein may
prove to be useful in preventing and treating preventing
A healthy eye is essential for
good vision. Diabetic retinopathy
, one of the
most common diabetic eye diseases, usually affects both the eyes and causes progressive damage to the retina.
Diabetic retinopathy is the
leading cause of new cases of blindness. It is known to affect 40 to 45 percent
of American diabetics. In this condition, the eye's
regular blood vessels are taken over by abnormal, fragile vessels that leak
into the eye thereby causing damage and subsequently blindness.
In its early stages, diabetic retinopathy can be
prevented by controlling diabetes. However in the later stages,
or injection therapy is recommended to prevent further damage
to the eyes.
A protein which has been recently identified, known as angiopoietin-like 4 (ANGPTL4), has
been implicated to play an important role in the development of diabetic
retinopathy. Researchers believe that since this protein is present in high levels
in eyes of people with diabetic retinopathy, blocking it as well as
another protein, known as vascular endothelial growth
factor (VEGF), could
possibly prevent retinopathy-related blindness. VEGF has been already
identified as one of the proteins causing diabetic retinopathy. Researchers are
also of the opinion that measurement of ANGPTL4 levels could also help diagnose
and treat retinopathy at a much early stage.
Akrit Sodhi, Assistant Professor of Ophthalmology at the Johns Hopkins University School of
Medicine in Baltimore explained that, although anti-VEGF drugs such as
, ranibizumab and aflibercept, often slowed the onset of
retinopathy, they were unable to stop it altogether. This suggested that there
were other factors in the eye that played a role in retinopathy, in addition to
VEGF, and their goal was to identify these other proteins.
A study was thus undertaken which had three group of participants. The
first group of people had healthy eyes and no diabetes, the second group had
diabetes but no retinopathy, and the third group had both diabetes and
When tested and as expected, study participants from
the third group had higher levels of VEGF in their eyes. However, some had low
VEGF levels. This led the researchers to believe that there must be another
protein too which is responsible for causing the disease.
The team of researchers then performed few experiments
on human cells and mice during which they discovered the protein ANGPTL4. The researchers found
that study participants with diabetic retinopathy had consistently higher
levels of ANGPTL4 as compared to the other two groups, regardless of their VEGF
commented, "When we blocked this factor in fluid from patients with diabetic
retinopathy, this was extremely effective for blocking the ability to promote
blood vessel growth in tissue culture."
The results of the study was published in the journal Proceedings of the National Academy of Sciences
The researchers are
further studying the role of ANGPTL4 in other conditions such as macular
degeneration. They are also evaluating the development of drugs capable of