Abstract
Purpose :
Abnormal retinal neovascularization associated with various retinopathies can result in irreversible vision loss. Although the mechanisms involved in the occurrence of retinal neovascularization is still under investigation, increasing evidence suggests that aberrant Wnt signaling activated by reactive oxygen species (ROS), such as hydrogen peroxide (H2O2), participates in the pathogenesis of abnormal neovascularization. We utilized novel small molecule Wnt inhibitors to study the role of ROS regulating Wnt activity affecting tight junction formation and transcytosis of human retinal microvascular endothelial cells (HRMECs) in vitro.
Methods :
HRMECs were treated with H2O2 for 30 minutes, H2O2 together with Wnt inhibitors or vehicle. Quantitative PCR (qPCR) analysis of Axin2 was utilized to assess the inhibitory profile of Wnt inhibitors and the activation profile of Wnt signaling upon H2O2 stimulation. Transepithelial endothelial Electrical Resistance (TEER) was used to evaluate cell tight junction formation. Transcytosis assay was used to explore whether Wnt signaling regulates transcytosis of HRMEC in vitro.
Results :
Application of H2O2 to the HRMECs leads to increased Axin2 mRNA expression. In contrast to this, Wnt inhibitors attenuated H2O2 mediated Axin2 mRNA expression. Additionally, HRMECs treated with H2O2 presented altered tight junction formation and transcytosis that were regulated by Wnt inhibitors.
Conclusions :
We found that increased Wnt signaling activity was detected in H2O2 treated HRMECs. The abilities of HRMECs to form tight junction and transcytosis affected by H2O2 treatment through upregulation of Wnt signaling in vitro. Moreover, these effects were effectively suppressed by small-molecule Wnt inhibitors.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.