1. Downregulation of acylglycerol kinase suppresses high-glucose-induced endothelial-mesenchymal transition in human retinal microvascular endothelial cells through regulating the LPAR1/TGF-β/Notch signaling pathway.
- Author
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Wang H, Feng Z, Han X, Xing Y, and Zhang X
- Subjects
- Cells, Cultured, Gene Expression Regulation genetics, Humans, Receptors, Lysophosphatidic Acid metabolism, Receptors, Notch genetics, Transforming Growth Factor beta genetics, Down-Regulation genetics, Down-Regulation physiology, Endothelial Cells physiology, Epithelial-Mesenchymal Transition drug effects, Epithelial-Mesenchymal Transition genetics, Glucose adverse effects, Phosphotransferases (Alcohol Group Acceptor) genetics, Phosphotransferases (Alcohol Group Acceptor) metabolism, Receptors, Lysophosphatidic Acid genetics, Receptors, Notch metabolism, Retinal Vessels cytology, Signal Transduction genetics, Signal Transduction physiology, Transforming Growth Factor beta metabolism
- Abstract
The endothelial-mesenchymal transition (EndMT) participates in the progression of diabetic retinopathy (DR), but cell-intrinsic factors modulating this process remain elusive. In this study, we explored the role of lysophosphatidic acid (LPA) - producing enzyme, acylglycerol kinase (AGK), in the EndMT of human retinal microvascular endothelial cells (HRECs) under high-glucose (HG) conditions. We found that AGK was significantly elevated in HG-treated cells. In addition, AGK knockdown reversed the HG-induced EndMT in HRECs, which was evidenced by the increased endothelial markers (CD31 and VE-cadherin) and decreased mesenchymal markers (FSP1 and α-SMA). Furthermore, downregulation of AGK inhibited the HG-induced activation of transforming growth factor β (TGF-β)/Notch pathways, whereas exogenous TGF-β1 (10 ng/mL) impeded the inhibitory effects of AGK knockdown on HG-induced EndMT in HRECs. Additionally, the silencing of AGK abolished the HG-induced upregulation of LPA and its receptor, LPA receptor 1 (LPAR1), and overexpression of LPAR1 further rescued the AGK knockdown-mediated inhibition of the EndMT process. In conclusion, we demonstrate that downregulation of AGK suppresses HG-induced EndMT in HRECs through regulating the LPAR1/TGF-β/Notch signaling pathway, indicating that AGK might be a potential therapeutic target for the treatment of DR.
- Published
- 2022
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