[Changes of reactive oxygen species in mitochondria of retinal endothelial cells and pericytes induced by high glucose].

Objective: To study changes of reactive oxygen species (ROS) in mitochondria of bovine retinal endothelial cells and pericytes cultured in high-glucose and its relevance with the pathogenesis of diabetic retinopathy.
Methods: Bovine retinal endothelial cells and pericytes were cultured with selective culture media. ROS changes in mitochondria of retinal endothelial cells and pericytes in response to different concentrations of glucose were detected with scanning laser confocal microscope. The mitochondria membrane potential (MMP) and cell death ratio (CDR) were measured with flow cytometry. Expression of MnSOD and uncoupling protein (UCP) were detected with reverse-transcriptase PCR (RT-PCR).
Results: In high-glucose, increased ROS was seen in mitochondria of retinal endothelial cells and pericytes. However MMP and CDR only increased in endothelial cells, no change was found in pericytes. UCP1, 2 mRNA expressed in cultured cells whereas UCP3 was negative. The expression of UCP1, 2, MnSOD mRNA changed with the variation of glucose concentrations.
Conclusions: Increasing of ROS production in mitochondria of retinal endothelial cells and pericytes can be induced by high glucose. There is feedback accommodation mechanism between ROS increasing and MMP elevation in endothelial cells. The different features of endothelial cells and pericytes in high glucose demonstrate their roles in pathogenesis of diabetic retinopathy are different.