Abstract
Purpose :
To examine the effects of nerve growth factor (NGF) on apoptosis and inflammation in diabetic cornea using human corneal epithelial cells (HCECs) and streptozotocin-induced diabetic rat cornea.
Methods :
The effects of NGF on high glucose-induced apoptosis were investigated in HCECs using Annexin-V and PI staining, and cleaved caspase-3 and BAX expression levels using immunoblotting. The effects of NGF on inflammatory response were examined using quantified IL-1β and TNF-a expression levels by multiplex cytokine analysis, and NF-kB activation and IkB-a degradation by western blot analysis. Diabetes was induced by intraperitoneal streptozotocin injection in male Sprague–Dawley rats. The SD rats were divided into 3 groups. (1) Control group (2) Diabetic control group (3) NGF group; Topical NGF were given 3 times a day for 3 weeks. Apoptosis was detected by TUNEL assay. The expressions of caspase-3 and IL-1 β were studied by immunohistochemistry in corneal tissues.
Results :
High glucose at 25 mM stimulated ROS generation, apoptosis, and release of inflammatory cytokines in HCECs. The addition of NGF markedly reduced the high glucose-induced ROS activation, Annexin-PI-positive cells, and levels of cleaved caspase-3, BAX, IL-1β, and TNF-α in HCECs. Enhanced apoptotic and inflammatory responses and expressions of cleaved caspase-3 and IL-1 β in diabetic corneas of rat were observed. These responses were markedly reduced by NGF.
Conclusions :
Apoptosis and inflammation were enhanced in diabetic cornea and NGF contributed to reduction of apoptotic and inflammatory response in vivo and in vitro conditions. NGF may be a novel therapeutic approach for managing diabetic keratopathy.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.