Abstract
Purpose :
The protein inhibitor of activated STAT-1 (PIAS1) is one of the well-known SUMOylation E3 ligases and has been shown implicated in different biological processes including control of apoptosis. We previously demonstrated that apoptosis of lens epithelial cells (LECs) induced by stress factors acts as the common cellular basis for non-congenital cataractogenesis. Whether PIAS1 is implicated in the stress-induced lens pathogenesis remains elusive. Here we present evidence to show that PIAS1 is implicated in the stress-induced lens pathogenesis. Mechanistically, PIAS1 controls p53 sumoylation at K386 residue to control stress-induced apoptosis through the proapoptotic regulator Bax.
Methods :
Mouse lenses were treated with glucose oxidase (GO) to induce cataract formation. QRT-PCR and western blot were used for analyzing gene expression. Both in vitro mutagenesis and sumoylation as well as Co-IP were used to confirm PIAS1 catalysis of p53 sumoylation. PIAS1 expression construct was generated to establish PIAS1 expression stable line. CRISPR/Cas9 technology was used to silence PIAS1, p53 or Bax expression. CellTiter-Glo® luminescent cell viability assay was used to detect apoptosis.
Results :
In the GO-induced cataract model, expression of PIAS1 was significantly downregulated. While overexpression of PIAS1 in mouse LECs accelerates apoptosis, its knockout enhanced viability. Downstream PIAS1, we have identified that members of the Bcl2- family play an important role.
Conclusions :
PIAS1 is implicated in stress-induced pathogenesis of the ocular lens. PIAS1 regulates stress-induced apoptosis of lens epithelial cells through control of p53 sumoylation and its downstream target, the proapoptotic target, Bax. (Supported by grants from National Natural Science Foundation of China, 82000876, 81770910, 81970787, 81700821, 81970784, 81900842) and the grant from Guangdong province (2019B1515120014) as well as the Fundamental Funds from the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University (3030901010110).
This is a 2021 ARVO Annual Meeting abstract.