Fig. 4

GNAZ is a negative regulator of ADAM17. G protein subunit alpha Z (GNAZ), which is ubiquitously expressed in retinas, is thought to be regulated by the biological clock. A The co-immunoprecipitation data demonstrated the association between GNAZ and ADAM17 in untreated bEnd.3 cell. However, blue light exposure (160 lx, 3 h) seemed to disturb the protein–protein interaction. In addition, the GNAZ/ADAM17 protein complex is harmful for ADAM17 phosphorylation. B Immunofluorescent staining images showed the co-localization of GNAZ (red) and ADAM17 (green) on the cell membrane of untreated HREC. After blue light stimulation (160 lx, 3 h), GNAZ moved from the cell membrane to the cytosol. The nucleus was stained by DAPI (blue). C Silencing GNAZ was achieved by the transfection of shRNA. The successful knockdown of GNAZ coincided with the downregulation of CLDN5 and the hyperactivation of ADAM17. (**p < 0.01, ***p < 0.001, indicates statistical difference from the control). D GNAZ-KD clones were increased in their ADAM17 activity. (E) The TEER value also dropped in GNAZ-KD clones. (***p < 0.001, indicates statistical difference from the wild-type control). F TEM images showed an obvious cleft between adjacent HRECs, instead of the appearance of a TJ