Purchase this article with an account.
Xiaoxi Qiao, Yue Li, Xiuli Liu, Tongrong Zhou, Mark Kelley, Paul Edwards, Hua Gao; APE1/Ref-1 redox inhibitor APX3330 modulates choroidal endothelial cells by transcriptional regulation of NF-κB and STAT3 activity. Invest. Ophthalmol. Vis. Sci. 2013;54(15):4101.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
We previously reported that APE1/Ref-1 redox function is required for retinal angiogenesis and APE1/Ref-1 redox inhibition with a novel small molecule inhibitor APX3330 inhibits both retinal and choroidal neovascularization in vitro and in vivo. In this study, we investigated which transcription factor(s) mediate such action in choroidal endothelial cells.
Choroid endothelial cells (CEC, RF/6A) from rhesus monkey were used in this study. Cells were first treated with various doses of APX3330 or vehicle control. A cell-based reporter gene assay was used to examine the activities of transcription factor hypoxia induced factor (HIF1α), nuclear factor kappa B (NF-κB) and signal transducers and activators of transcription3 (STAT3). Expression levels of activated NF-κB p65 and pSTAT3 were further verified by western blot analysis. Production of monocyte chemotactic protein-1 (MCP-1) was determined by ELISA after incubating these cells in an inflammatory cytokine mixture (ICM).
The reporter gene assay revealed that APX3330 dose-dependently inhibited the transcriptional activities of both NF-κB and STAT3. A low dose treatment of 10 μM APX3330 had minimal effect on the NF-κB transcriptional activity, but it remarkably reduced STAT3 activity by about 44%; whereas 20 μM APX3330 reduced NF-κB activity by 32% and STAT3 activity by 53% in these endothelial cells. Expression levels of activated pSTAT3 and NF-κB p65 were significantly reduced at higher dosages of 40 μM and 80 μM APX3330, respectively. STAT3 is more sensitive than NF-κB to the APX3330-mediated APE1/Ref-1 redox inhibition than NF-κB. In addition, 40 μM APX3330 treatment significantly attenuated the ICM-induced increase of MCP-1 (p < 0.05). The level and activity of HIF1α were not altered by APX3330 in these cells.
APE1/Ref-1 redox inhibitor APX3330 elicits its inhibition on choroidal endothelial cells by inhibiting the transcriptional activities of STAT3 and NF-κB at low doses and the expression levels at high doses. Inhibiting the redox function of APE1/Ref-1 may offer a novel approach to control choroidal neovascularization for AMD treatment.
This PDF is available to Subscribers Only