Abstract
Purpose :
The aim of current investigation was to explore the influence of hypobaric hypoxia on the rat retina and determine whether resveratrol has a protective efficacy on hypoxic damage to retina.
Methods :
54 Sprague-Dawley(SD) rats were randomly divided into the control, hypoxia group and resveratrol +hypoxia group.The hypoxia group and the resveratrol +hypoxia group were maintained at low pressure oxygen cabin (simulation for 5000m above sea level), and the resveratrol +hypoxia group was given daily intraperitoneal injection(30mg/kg,per day). Retina was removed after rats were treated for 7 days. Immunohistochemisty was processed for detecting the expression of thioredoxin 1 (TRX1), thioredoxin 2 (TRX2) and thioredoxin-interacting protein (TXNIP). The levels of superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)in retina were measured by ELISA. RT-PCR was performed to evaluate the mRNA expression of hypoxia inducible factor-1 (HIF-1),caspase 3, caspase 9, heat shock protein 70 (HSP70), and heat shock protein 90 (HSP90).
Results :
Increased TXNIP, TRX1 and TRX2 expression presented in hypoxia group compared with controls, resveratrol treatment reversed these changes and especially significantly suppressed TRX1 and TRX2 expression in retinas, compared with those of the hypoxia group(P = 0.023, P = 0.034 respectively). Hypobaric hypoxia reduced protein level of GSH-Px(41.55±2.04pg/ml) and SOD(137.21±16.10ng/ml) as compared to unexposed group(50.22±2.30pg/ml, 164.47±25.31ng/ml respectively) , the administration of resveratrol attenuated hypoxia-induced alterations by enhancing the activity of two proteins(P=0.01, P>0.05 respectively). In comparison with controls, hypoxia up-regulated the gene expression levels of caspase3(P < 0.001), caspase9 (P =0.007), HSP70(P=0.025), HSP90 (P < 0.001) and HIF-1(P = 0.034). Resveratrol administration caused a significant decreases in the gene expression of caspase3(P < 0.001), HSP90(P = 0.024) and HIF-1 mRNA (P =0.001) as well as an increase in HSP70 mRNA when compared with the hypoxia group.
Conclusions :
Hypobaric hypoxia poses a pathological impact on rat retina. The intervention of resveratrol elicits a protective role on hypobaric hypoxia-induced retina impairment by increasing antioxidant production and regulating the expression of hypoxia-related genes.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.