Hang Yang1, Yong-Yan Luo2, Lue-Tao Zhang3, Kai-Ran He3, Xiao-Jun Lin3. 1. Department of Emergency and Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Second Road, Guangzhou, 510080, Guangdong, China. hangyang_gpph@163.com. 2. Department of Emergency and Critical Care Medicine, Zhuhai Hospital of Guangdong Provincial People's Hospital, 2 Hongyang Road, Sanzao Town, Jinwan District, Zhuhai, China. 3. Department of Emergency and Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Second Road, Guangzhou, 510080, Guangdong, China.
Abstract
BACKGROUND: Sepsis is an abnormal immune-inflammatory response that is mainly caused by infection. It can lead to life-threatening organ dysfunction and death. Severely damaged tissue cells will release intracellular histones into the circulation as damage-related molecular patterns (DAMPs) to accelerate the systemic immune response. Although various histone-related cytotoxicity mechanisms have been explored, those that affect extracellular histones involved in vascular smooth muscle cell (VSMC) dysfunction are yet to be determined. METHODS: Mouse aortic vascular smooth muscle cells (VSMCs) were stimulated with different concentrations of histones, and cell viability was detected by CCK-8 assay. Cellular senescence was assessed by SA β-gal staining. C57BL/6 mice were treated with histones with or without BML-275 treatment. RT-qPCR was performed to determine the expression of inflammatory cytokines. Western blotting was used to analyze the expression of NLRP3, ASC and caspase-1 inflammasome proteins. The interaction of NLRP3 and ASC was detected by CoIP and immunofluorescence staining. RESULTS: In this study, we found that extracellular histones induced senescence and inflammatory response in a dose-dependent manner in cultured VSMCs. Histone treatment significantly promoted apoptosis-associated speck-like protein containing CARD (ASC) as well as NACHT, LRR and PYD domains-containing protein 3 (NLRP3) interaction of inflammasomes in VSMCs. Forkhead box protein O4 (FOXO4), which is a downstream effector molecule of extracellular histones, was found to be involved in histone-regulated VSMC inflammatory response and senescence. Furthermore, the 5'-AMP-activated protein kinase (AMPK) signaling pathway was confirmed to mediate extracellular histone-induced FOXO4 expression, and blocking this signaling pathway with an inhibitor can suppress vascular inflammation induced by extracellular histones in vivo and in vitro. CONCLUSION: Extracellular histones induce inflammation and senescence in VSMCs, and blocking the AMPK/FOXO4 pathway is a potential target for the treatment of histonemediated organ injury.
BACKGROUND: Sepsis is an abnormal immune-inflammatory response that is mainly caused by infection. It can lead to life-threatening organ dysfunction and death. Severely damaged tissue cells will release intracellular histones into the circulation as damage-related molecular patterns (DAMPs) to accelerate the systemic immune response. Although various histone-related cytotoxicity mechanisms have been explored, those that affect extracellular histones involved in vascular smooth muscle cell (VSMC) dysfunction are yet to be determined. METHODS: Mouse aortic vascular smooth muscle cells (VSMCs) were stimulated with different concentrations of histones, and cell viability was detected by CCK-8 assay. Cellular senescence was assessed by SA β-gal staining. C57BL/6 mice were treated with histones with or without BML-275 treatment. RT-qPCR was performed to determine the expression of inflammatory cytokines. Western blotting was used to analyze the expression of NLRP3, ASC and caspase-1 inflammasome proteins. The interaction of NLRP3 and ASC was detected by CoIP and immunofluorescence staining. RESULTS: In this study, we found that extracellular histones induced senescence and inflammatory response in a dose-dependent manner in cultured VSMCs. Histone treatment significantly promoted apoptosis-associated speck-like protein containing CARD (ASC) as well as NACHT, LRR and PYD domains-containing protein 3 (NLRP3) interaction of inflammasomes in VSMCs. Forkhead box protein O4 (FOXO4), which is a downstream effector molecule of extracellular histones, was found to be involved in histone-regulated VSMC inflammatory response and senescence. Furthermore, the 5'-AMP-activated protein kinase (AMPK) signaling pathway was confirmed to mediate extracellular histone-induced FOXO4 expression, and blocking this signaling pathway with an inhibitor can suppress vascular inflammation induced by extracellular histones in vivo and in vitro. CONCLUSION: Extracellular histones induce inflammation and senescence in VSMCs, and blocking the AMPK/FOXO4 pathway is a potential target for the treatment of histonemediated organ injury.
Authors: Carolin Fleischmann; André Scherag; Neill K J Adhikari; Christiane S Hartog; Thomas Tsaganos; Peter Schlattmann; Derek C Angus; Konrad Reinhart Journal: Am J Respir Crit Care Med Date: 2016-02-01 Impact factor: 21.405
Authors: Rhian M Touyz; Rheure Alves-Lopes; Francisco J Rios; Livia L Camargo; Aikaterini Anagnostopoulou; Anders Arner; Augusto C Montezano Journal: Cardiovasc Res Date: 2018-03-15 Impact factor: 10.787