Abstract
Purpose: :
To investigate the expression of endoplasmic reticulum (ER) stress proteins in diabetic retinopathy.
Methods: :
Diabetes was induced in the SD rat by intra-peritoneal injection of streptozotocin. The protein expression of ER stress sensors including caspase-12, C/EBP-homologous protein (CHOP) and JUN N-terminal kinases (p-JNK) were examined by Immunofluorescent and Real-time PCR analysis.
Results: :
Real-time PCR assays showed that the mRNA expression of caspase-12, CHOP and p-JNK was up-regulated in diabetic retinas when compared with the normal control. In the normal retina, no positive caspase-12 staining was demonstrated. In the diatetic retina positive caspase-12 staining was mainly demonstrated in the ganglion cell layer, the inner nuclear layer and inner plexiform layer also showed positive labeling. In the normal retina, no positive CHOP staining was demonstrated. In the diatetic retina the positive CHOP staining was demonstrated in the ganglion cell layer. In the normal retina, no positive p-JNK staining was demonstrated. In the diatetic retina the positive p-JNK staining was demonstrated in the ganglion cell layer.
Conclusions: :
Activation of endoplasmic reticulum stress proteins appears to play an important role in diabetic retinopathy. Therefore endoplasmic reticulum stress modulators could become a strong candidate as a therapeutic agent in the treatment of this disease.
Keywords: diabetic retinopathy • apoptosis/cell death • ganglion cells