The activation of mTOR is required for monocyte pro-inflammatory response in patients with coronary artery disease.

Abstract

Nuclear factor-κB (NF-κB) is a key regulator of systematic inflammation in atherosclerosis (AS). The mammalian target of rapamycin (mTOR), a serine/threonine protein kinase, has emerged as an important regulator of chronic inflammation. However, the relationship between mTOR and NF-κB remains poorly defined. The aim of the present study was to investigate the role of mTOR in the pro-inflammatory pathway of human monocytes (HMCs) in patients with coronary artery disease (CAD) and to determine the interaction between mTOR and NF-κB signalling in the inflammatory state. HMCs were isolated from fasting blood samples of 68 patients with CAD and 59 subjects without CAD (non-CAD) to test the activity of NF-κB, p65 nuclear translocation and mTOR phosphorylation, which were all significantly elevated in the CAD group compared with those in the non-CAD group. The concentrations of serum interleukin (IL)-6 and tumour necrosis factor (TNF)-α were higher in the CAD group than in the non-CAD group. In an in vitro experiment, HMCs isolated from non-CAD subjects were used as culture model and were treated with sera extracted from CAD patients (CAD sera) or non-CAD subjects (con sera). CAD sera induced time-dependent phosphorylation of mTOR, aberrant NF-κB activation, as well as up-regulation of inflammatory factors. Moreover, inhibition of mTOR by pharmacological or genetic means abolished the CAD sera-triggered NF-κB activation and pro-inflammatory response. Furthermore, lipid-lowering drug statins partly blocked the CAD sera-activated mTOR and pro-inflammatory response. Our results show that CAD patients are in the pro-inflammatory state with increased NF-κB binding activity and enhanced mTOR phosphorylation. We also found that the activation of mTOR is required for the pro-inflammatory response via NF-κB-dependent pathway in HMCs, which unveils the underlying mechanism of AS and potential strategies to attenuate AS in clinical practice.

• Authors: Shanshan Gao, Weimin Liu, Xiaozhen Zhuo, Lijun Wang, Gang Wang, Tao Sun, Zhao Zhao, Junhui Liu, Yuling Tian, Juan Zhou, Zuyi Yuan, Yue Wu
• Journal: Clinical science (London, England : 1979) (Clin Sci (Lond)) Vol. 128 Issue 8 Pg. 517-26 (Apr 2015) ISSN: 1470-8736 [Electronic] England
• PMID: 25428582 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Hydroxymethylglutaryl-CoA Reductase Inhibitors
• Inflammation Mediators
• Lipoproteins, LDL
• NF-kappa B
• oxidized low density lipoprotein
• Phosphoserine
• MTOR protein, human
• TOR Serine-Threonine Kinases

Topics

• Coronary Artery Disease (blood, drug therapy, enzymology, pathology)
• Enzyme Activation (drug effects)
• Female
• Gene Knockdown Techniques
• Humans
• Hydroxymethylglutaryl-CoA Reductase Inhibitors (pharmacology, therapeutic use)
• Inflammation (metabolism, pathology)
• Inflammation Mediators (metabolism)
• Lipoproteins, LDL (metabolism)
• Male
• Middle Aged
• Monocytes (enzymology, pathology)
• NF-kappa B (metabolism)
• Phosphorylation (drug effects)
• Phosphoserine (metabolism)
• Protein Binding (drug effects)
• Signal Transduction (drug effects)
• TOR Serine-Threonine Kinases (metabolism)
• Time Factors