Blockade of insulin receptor substrate-1 inhibits biological behavior of choroidal endothelial cells

Abstract

AIM: To investigate the effects of blockade of insulin receptor substrate-1 (IRS-1) on the bio-function of tube formation of human choroidal endothelial cells (HCECs). METHODS: Quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were performed to determine the expression level of IRS-1 and phospho-IRS-1 in HCECs. Tube formation of HCECs was analyzed using three dimensional in vitro Matrigel assay with or without IRS-1 blockage via IRS-1 inhibitor (GS-101) and vascular endothelial growth factor receptor 2 (VEGFR2) inhibitor. In addition, cell counting kit (CCK)-8 and Transwell migration assay were exerted to analyze the effects of blockade of IRS-1 on the bio-function of proliferation and migration of HCECs, respectively. The apoptosis of HCECs was examined using flow cytometry (FCM). RESULTS: RT-PCR and Western blot revealed that IRS-1 phospho-IRS-1 were expressed in HCECs and the expression level was enhanced by stimulation of VEGF-A. The number of tube formation was decreased significantly in GS-101 treated groups compared to phosphate buffered saline (PBS) treated control groups. Furthermore, both cell proliferation and migration of HCECs were decreased in the presence of GS-101. FCM analysis showed that the apoptosis of HCECs was enhanced when the cells were treated with GS-101. Western blot also showed that the expression level of cleaved-caspase 3 in GS-101 treated group was higher than that in control group. CONCLUSION: Blockade of IRS-1 can inhibit tube formation of HCECs through reducing cell proliferation and migration and promoting cell apoptosis.

Keywords

• insulin receptor substrate-1
• choroidal endothelial cells
• neovascularization
• proliferation