Decorin can reverse the expression ratio of bcl-2 to bax in high glucose-treated cells (Fig 2C and 2D). Open in a (-)-Huperzine A separate window Fig 2 Effects of decorin on cell apoptosis.(A) Quantitative analysis of HLEB3 cell apoptosis tested by circulation cytometry with Annexin-V-FITC apoptosis detection kit. by western blotting. Small interfering RNA transfection to p22phox and p38 MAPK was also carried out on (-)-Huperzine A HLEB3. Results High glucose caused HLE cells oxidative stress and apoptosis exhibiting the increase of apoptotic cells and ROS production and decrease of bcl-2/bax ratio, GSH/GSSG ration and SOD activity. P22phox and phospho-p38 MAPK were upregulated in high glucose treated HLEB3 (-)-Huperzine A cells. Knocking down p22phox or p38 by siRNAs can reduce high glucose induced cell apoptosis and oxidative stress level. Silencing p22phox by siRNA can downregulate the phosphorylation of p38 MAPK. Decorin can inhibit the apoptosis, oxidative stress level and the induction of p22phox and phospho-p38 of HLEB3 induced by high glucose. Furthermore, the expression of p22phox and p38 were found significantly increased in lens anterior capsules of diabetic cataract patients compared to that of normal age-related cataract patients. Conclusions Results showed that p22phox-p38 pathway may be participated in high glucose induced lens epithelial cell injury, decorin may inhibit the high glucose induced apoptosis and oxidative stress injury by suppressing this pathway in part. Introduction Diabetic cataract is one of the most important complications of diabetes [1]. Oxidative stress induced by high glucose plays a pivotal role in the mechanism of diabetic cataract. Oxidation and aggregation of protein in lens epithelium cells, which led to lens opacity, are caused by high glucose [2]. Apoptosis and oxidative stress, which participated in the formation of diabetic cataract, occurred when human lens epithelial (HLE) cells exposing for 24 h to the condition of high glucose [3]. Decorin, which is a small leucine-rich proteoglycan, has been found to negatively regulate a variety of cellular functions when binding to extracellular matrix components or cell surface receptors [4, 5]. Overexpression of decorin could restrain angiogenesis mediated by tumor cell by suppressing the production of vascular endothelial growth factor (VEGF) [6]. Administration of decorin into corneal stroma could inhibit neovascularization of cornea in rabbit (-)-Huperzine A model [7]. In the post-traumatic brain injuries (TBI) rat cerebrum, it is reported (-)-Huperzine A that decorin increased the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH) and prevented oxidative stress injury and apoptosis [8, 9]. Preliminary data of our team showed that decorin can inhibit retina pigmentosa epithelial (RPE) barrier disruption under diabetic condition through suppression of p38 mitogen-activated protein kinase (MAPK) activation [10]. However, the influence of decorin on diabetic cataract has not been studied yet. In the current study, the effect and potential mechanism of decorin on high glucose induced oxidative stress and apoptosis in HLE cells were investigated. Apoptosis, reactive oxygen species (ROS), SOD and GSH were decided. Besides, p38 MAPK phosphorylation and the expressed level of p22phox of HLEB3 and human lens anterior capsules were evaluated. Furthermore, the role of p22phox and p38 MAPK were evaluated in mediating the oxidative stress caused by high glucose. Materials and methods Antibodies and chemical brokers Mouse anti-bcl-2 (Abcam, Cambridge, UK), mouse anti-bax (Abcam, Cambridge, UK), mouse anti–actin (Proteintech, Chicago, Illinois, USA), rabbit anti-p38 (Abcam, Cambridge, UK), rabbit anti-phospho-p38 (Thr180/Tyr182, Abcam, Cambridge, UK), PTCRA mouse anti-p22phox (Gentex, Irvine, USA), goat anti-mouse (Proteintech, Chicago, Illinois, USA) and goat anti-rabbit (Proteintech, Chicago, Illinois, USA) antibodies, recombinant human decorin (R&D Systems, Minneapolis, MN, USA), apoptosis detection kit (Beyotime Inst. Biotech, Haimen, China), Cell Counting Kit-8 (CCK-8, Dojindo, Japan). Human lens anterior capsules The human lens anterior capsular tissues were obtained from the eye-tissue lender. All procedures for collecting the anterior capsules followed the guidelines for the use of human materials. This study and the protocols used in the paper were approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University or college. All patients offered written reports of informed consent..