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Antagonism of receptor interacting protein 1 using necrostatin-1 in oxidized LDL- induced endothelial injury
Songtao An1, Yanyan Qi2, Zhiguo Zhang3
1Department of Cardiology, Zhongshan Hospital Affiliated to Fudan University, Shanghai, 200032, China.
Abstract:
Oxidized LDL (ox-LDL) is the key risk factor of developing atherosclerosis. In endothelial cells, exposure of ox-LDL causes endothelial dysfunction and injury. In this study, we investigated the role of receptor interacting protein 1 (RIP1), one of the kinases involved in apoptosis and necroptosis mediated by the death receptor tumor necrosis factor receptor (TNFR), in endothelial dysfunction. We show that RIP1 is responsively induced in human umbilical vein endothelial cells (HUVECs) upon ox-LDL treatment. Blockage of RIP1 activity by its antagonist, necrostatin-1, ameliorates ox-LDL-induced nitric oxide (NO) reduction and induction of vascular adhesion molecules, including vascular cell adhesion molecule 1 (VCAM-1) and E-selectin, as well as adhesion of immune cells to endothelial cells. Mechanistically, we show that inactivation of RIP1 by necrostatin-1 suppressed nuclear factor κB (NF-κB) cascade signals, including activation of IKKα, nuclear factor kappa B inhibitor protein α (IκBα), accumulation of nuclear p65 and NF-κB promoter activity. Silencing of RIP1 largely attenuates the action of ox-LDL on the expression of vascular adhesion molecules and adhesion of immune cells to endothelial cells. Collectively, our data indicate that the response of RIP1 to ox-LDL and its activation are required for ox-LDL-induced endothelial injury.
Insights
Oxidized LDL (ox-LDL) triggers endothelial dysfunction by activating receptor interacting protein 1 (RIP1). Inhibiting RIP1 protects against ox-LDL-induced injury, highlighting RIP1 as a therapeutic target for atherosclerosis.
Area of Science:
- Cardiovascular Biology
- Molecular Medicine
- Cellular Signaling
Background:
- Oxidized low-density lipoprotein (ox-LDL) is a primary driver of atherosclerosis, causing endothelial dysfunction and injury.
- Receptor interacting protein 1 (RIP1) is a kinase involved in cell death pathways, including apoptosis and necroptosis, mediated by tumor necrosis factor receptor (TNFR).
Purpose of the Study:
- To investigate the role of RIP1 in ox-LDL-induced endothelial dysfunction.
- To determine if RIP1 inhibition can ameliorate ox-LDL-induced endothelial injury.
Main Methods:
- Treatment of human umbilical vein endothelial cells (HUVECs) with ox-LDL.
- Assessment of RIP1 induction and activity.
- Pharmacological inhibition of RIP1 using necrostatin-1.
- Evaluation of nitric oxide (NO) levels, vascular adhesion molecule expression (VCAM-1, E-selectin), and immune cell adhesion.
- Analysis of the nuclear factor-kappa B (NF-κB) signaling pathway.
- Gene silencing of RIP1.
Main Results:
- RIP1 expression is induced in HUVECs upon ox-LDL treatment.
- Necrostatin-1 (RIP1 inhibitor) reduced ox-LDL-induced NO reduction, vascular adhesion molecule expression, and immune cell adhesion.
- Necrostatin-1 suppressed NF-κB signaling components (IKKα, IκBα, p65 nuclear translocation, and promoter activity).
- RIP1 silencing attenuated ox-LDL effects on adhesion molecules and immune cell adhesion.
Conclusions:
- RIP1 activation is a critical mediator of ox-LDL-induced endothelial injury.
- Targeting RIP1 activity offers a potential therapeutic strategy for preventing or treating atherosclerosis-related endothelial dysfunction.
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