Research Paper Volume 16, Issue 9 pp 8070—8085
KLF4 inhibited the senescence-associated secretory phenotype in ox-LDL-treated endothelial cells via PDGFRA/NAMPT/mitochondrial ROS
- 1 Department of Cardiology, Shanghai Tongji Hospital, School of Medicine, Tongji University, Shanghai 200092, China
Received: September 25, 2023 Accepted: April 4, 2024 Published: May 8, 2024
https://doi.org/10.18632/aging.205805How to Cite
Copyright: © 2024 Ding et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
Background: Inflammation is one of the significant consequences of ox-LDL-induced endothelial cell (EC) dysfunction. The senescence-associated secretory phenotype (SASP) is a critical source of inflammation factors. However, the molecular mechanism by which the SASP is regulated in ECs under ox-LDL conditions remains unknown.
Results: The level of SASP was increased in ox-LDL-treated ECs, which could be augmented by KLF4 knockdown whereas restored by KLF4 knock-in. Furthermore, we found that KLF4 directly promoted PDGFRA transcription and confirmed the central role of the NAPMT/mitochondrial ROS pathway in KLF4/PDGFRA-mediated inhibition of SASP. Animal experiments showed a higher SASP HFD-fed mice, compared with normal feed (ND)-fed mice, and the endothelium of EC-specific KLF4-/- mice exhibited a higher proportion of SA-β-gal-positive cells and lower PDGFRA/NAMPT expression.
Conclusions: Our results revealed that KLF4 inhibits the SASP of endothelial cells under ox-LDL conditions through the PDGFRA/NAMPT/mitochondrial ROS.
Methods: Ox-LDL-treated ECs and HFD-fed mice were used as endothelial senescence models in vitro and in vivo. SA-β-gal stain, detection of SAHF and the expression of inflammatory factors determined SASP and senescence of ECs. The direct interaction of KLF4 and PDGFRA promotor was analyzed by EMSA and fluorescent dual luciferase reporting analysis.
Abbreviations
KLF4: Krüppel-like factor 4; ox-LDL: Oxidized low density lipoprotein; PDGFRA: Platelet-derived growth factor receptor α; NAMPT: Nicotinamide phosphoribosyltransferase; ROS: Reactive oxygen species; SASP: Senescence-associated secretory phenotype; SA-β-gal: Senescence-associated β-galactosidase; SAHF: Senescence-associated heterochromatin aggregation; EC: Endothelial cell; IL-1: Interleukin 1; ICAM-1: Intracellular adhesion molecule 1; TNF-α: Tumor necrosis factor; MCP-1: Monocyte chemoattractant protein 1; TAD: Transactivation domain; MitoROS: Mitochondrial reactive oxygen species; NIH: National Institutes of Health; Adv: Adenoviruses; sh-RNA: Short hairpin RNA; HUVEC: Human umbilical vein endothelial cell; ECM: Endothelial cell media; IL-1β: Interleukin 1 beta; IL-6: Interleukin 6; IL-18: Interleukin 18; MMP9: Matrix metallopeptidase 9; TGF-β: Transforming growth factor beta 1; CXCR-2: C-X-C motif chemokine receptor 2; SDS-PAGE: Sodium dodecyl sulfate polyacrylamide gel electrophoresis; HRP: Horseradish peroxidase; EMSA: Electrophoretic mobility shift assay.