Endogenous glycation derivatives delay diabetic retinopathy
MedWire News: The progression of diabetic retinopathy (DR) may be slower in diabetic patients with high levels of soluble receptors of advanced glycation end products (sRAGE) than in those with low levels of the receptor, a study suggests.
The study also implicates soluble forms of vascular cell adhesion molecules (sVCAM-1) and nitric oxide (NO) in the development of DR, indicating that low sVCAM-1 and NO levels may help delay DR progression.
Basma Khalil (Misr International University, Cairo, Egypt) and colleagues hypothesize that sRAGE can protect blood vessels, such as those in the eye, from damage by advanced glycation end products (AGE), by limiting the binding of AGE to cell membrane RAGE.
They explain that in the body, AGEs bind to RAGE or to sRAGE. When AGEs bind to RAGE, an inflammatory response, which assists the development and progression of DR, is triggered in vessel walls. However, when AGEs bind to sRAGE, this response does not occur.
The team measured the serum levels of sVCAM-1, NO, and sRAGE in 37 patients with diabetes, and 20 healthy participants.
All patients with diabetes were classified as having no retinopathy (n=14), nonproliferative retinopathy (n=14), or proliferative retinopathy (n=9).
The findings, published in the Journal of Diabetes and its Complications, show that sRAGE levels varied with DR severity, with mean sRAGE levels being 1712.7 and 1833.1 pg/ml in healthy controls and diabetics without retinopathy, respectively, versus 1331.13 and 934.87 pg/ml in patients with NPDR and PDR, respectively.
All diabetic patients also had elevated levels of NO and sVCAM-1 compared with the healthy controls, at 96.43 versus 28.78 ng/ml, and 1310.22 versus 616.55 ng/ml, respectively.
The team also notes that the patients with more advanced forms of DR had higher NO and sVCAM-1 levels.
Khalil et al conclude: "sRAGE could be protective by acting as a decoy receptor for plasma AGEs."
They add: "The therapeutic potential for novel agents that can ameliorate AGE formation and attenuate RAGE signalling in the retina is recommended."
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By Lauretta Ihonor