LncRNA MALAT1 Regulates miR-144-3p to Facilitate Epithelial-Mesenchymal Transition of Lens Epithelial Cells via the ROS/NRF2/Notch1/Snail Pathway

Abstract

Diabetic cataract is a common complication of diabetes. The epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) is a key event in the development of diabetic cataracts. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been reported to be highly expressed in different tissues of diabetic patients. This study is aimed at investigating the function and mechanism of MALAT1 in the regulation of EMT in human LECs under high glucose conditions. MALAT1, α-smooth muscle actin (α-SMA), fibronectin (FN), and nuclear factor erythroid-derived 2-like 2 (NRF2) were highly expressed in the LECs of diabetic cataract patients and in the human LECs under high glucose conditions; meanwhile, the decreased expressions of E-cadherin and zonula occludens 1 (ZO-1) were detected. Knockdown of MALAT1 could significantly reduce ROS, prevent EMT, arrest S phase cell cycle, and suppress the expression of total NRF2 and its nucleus translocation in LECs. Furthermore, after NRF2 was knocked down, total NRF2, α-SMA, and FN in cells, and NRF2, Notch intracellular domain (NICD), and Snail were decreased in the nucleus. Using bioinformatics methods, we predicted that MALAT1 and NRF2 shared the same microRNA-144-3p (miR-144-3p) combining site. Luciferase reporter coupled with qRT-PCR assays revealed that miR-144-3p was a target of MALAT1, which was confirmed to downregulate miR-144-3p in the LECs. In addition, after transfection of miR-144-3p mimics or inhibitor, western blot assay demonstrated that miR-144-3p negatively regulated the expression of total NRF2, α-SMA, and FN in cells, and NRF2, NICD, and Snail in the nucleus without affecting Kelch-like ECH-associated protein 1 (KEAP1). Finally, we confirmed that transfection of shMALAT1 inhibited NRF2 expression, and its mediated EMT could be rescued by miR-144-3p inhibitor; transfection of pcDNA3.1-MALAT1 promoted NRF2 expression, and its mediated EMT could be reversed by miR-144-3p inhibitor. In summary, we demonstrate that MALAT1 regulates miR-144-3p to facilitate EMT of LECs via the ROS/NRF2/Notch1/Snail pathway.

DLRAPom: a hybrid pipeline of Optimized XGBoost-guided integrative multiomics analysis for identifying targetable disease-related lncRNA–miRNA–mRNA regulatory axes

“…All the P values ( t -tests) were less than 0.05 ( Figure 6 ). Furthermore, when searching the literature to obtain supportive evidence for the target interactions of MALAT1/hsa-miR-144-3p and hsa-miR-144-3p/ IRS1 in the key regulatory axis, we found in recently published articles that their biological targeting relationships were both confirmed by the dual-luciferase reporter assay [ 35–38 ]. However, the relationship of this key regulatory axis with GDM has not yet been reported.…”

lncRNA XIST knockdown suppresses cell proliferation and promotes apoptosis in diabetic cataracts through the miR‑34a/SMAD2 axis

“…DC is an early ocular complication in diabetic patients and one of the main causes of blindness ( 20 ). Certain studies have indicated that lncRNAs affect multiple biological processes in DC ( 21 , 22 ). Therefore, understanding the function of lncRNAs in LECs under HG conditions may enable the discovery of novel targets for DC treatment.…”

LncRNA XIST knockdown suppresses cell proliferation and promotes apoptosis in diabetic cataract via miR-34a/SMAD2 axis

“…DC is an early ocular complication in diabetic patients and one of the main causes of blindness [17]. Some literature indicated that lncRNAs affected multiple biological processes in DC [18, 19]. Thus, understanding the function of lncRNA in LECs development under HG is helpful to discover new targets for DC treatment.…”