Retinal heparanase expression in streptozotocin-induced diabetic rats

Area of Science:

• Ophthalmology
• Diabetology
• Molecular Biology

Background:

• Heparanase is an endoglycosidase with proangiogenic properties.
• It can induce vascular endothelial growth factor (VEGF) expression, a key factor in tumor angiogenesis.
• The role of heparanase in diabetic retinopathy is not fully understood.

Purpose of the Study:

• To evaluate heparanase expression in the retinas of rats with streptozotocin (STZ)-induced diabetes.
• To investigate the relationship between heparanase and VEGF in this diabetic model.
• To explore heparanase as a potential therapeutic target for diabetic retinopathy.

Main Methods:

• Cultured human retinal microvascular endothelial cells (HRECs) were exposed to high glucose.
• Diabetes was induced in Sprague-Dawley rats using STZ.
• Heparanase and VEGF expression were analyzed using Western blot, immunohistochemistry, and ELISA.
• A heparanase inhibitor (phosphomannopentaose sulfate) was administered.

Main Results:

• High glucose increased heparanase expression in HRECs.
• Diabetic rat retinas showed significantly higher heparanase expression (3.2-fold increase) compared to controls.
• VEGF levels were elevated in both high-glucose HRECs and diabetic rat retinas.
• Inhibition of heparanase reduced these increases.

Conclusions:

• Heparanase expression is upregulated in STZ-induced diabetic rat retinas.
• Increased heparanase is associated with elevated VEGF expression.
• Heparanase may contribute to the pathogenesis of diabetic retinopathy.
• Targeting heparanase could be a novel therapeutic strategy for diabetic retinopathy.