Abstract
Purpose: :
To measure the level of brain derived neurotrophic factor (BDNF) in the serum of patients with diabetic retinopathy and in the serum and retina of streptozotocin-induced diabetic rats.
Methods: :
The levels of BDNF in the serum of proliferative diabetic retinopathy (PDR) patients and in the serum and retina of diabetic rats were measured by ELISA techniques. Western blotting experiments were performed to quantitate the expression level of BDNF in diabetic retina. Caspase-3 activity was measured in diabetic rat retina using a caspase-3 colorimetric assay.
Results: :
The level of BDNF was significantly decreased in serum of PDR patients compared to non-diabetic healthy controls (25.5 ± 11.0 to 10.0 ± 8.2 ng/ml, p=0.001). The level of BDNF in the serum and retina of diabetic rats was also significantly reduced compared to non-diabetic controls (p< 0.05). Caspase-3 activity was increased in diabetic retina after 3 weeks of diabetes and remained elevated until 10 weeks, which negatively correlated with the level of BDNF (r = -0.544, p = 0.013).
Conclusions: :
Reduced level of BDNF in diabetes may cause apoptosis andneurodegeneration in diabetic retina which may lead to neuro-vascular damage later in diabetic retinopathy.
Keywords: diabetic retinopathy • retina: neurochemistry • neuroprotection