Ontology highlight
ABSTRACT: Background & aims
Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) has long been recognized as an adipokine. However, the exact role of eNAMPT in alcoholic liver disease (ALD) and its relevance to brown adipose tissue (BAT) remain largely unknown. This study aimed to evaluate the impact of eNAMPT on liver function and the underlying mechanisms involved in BAT-Liver communication.Methods
Serum eNAMPT levels were detected in the serum of both ALD patients and mice. Chronic and binge ethanol feeding was used to induce alcoholic liver injury in mice. An eNAMPT antibody, a coculture model of brown adipocytes and hepatocytes, and BAT-specific Nampt knockdown mice were used to investigate the role of eNAMPT in ALD.Results
Serum eNAMPT levels are elevated in ALD patients and are significantly positively correlated with the liver injury index. In ALD mice, neutralizing eNAMPT reduced the elevated levels of circulating eNAMPT induced by ethanol and attenuated liver injury. In vitro experiments revealed that eNAMPT induced hepatocyte ferroptosis through the TLR4-dependent mitochondrial ROS-induced ferritinophagy pathway. Furthermore, ethanol stimulated eNAMPT secretion from brown adipocytes but not from other adipocytes. In the coculture model, ethanol-induced release of eNAMPT from brown adipocytes promoted hepatocyte ferroptosis. In BAT-specific Nampt-knockdown mice, ethanol-induced eNAMPT secretion was significantly reduced, and alcoholic liver injury were attenuated. These effects can be reversed by intraperitoneal injection of eNAMPT.Conclusion
Inhibition of ethanol-induced eNAMPT secretion from BAT attenuates liver injury and ferroptosis. Our study reveals a previously uncharacterized critical role of eNAMPT-mediated BAT-Liver communication in ALD and highlights its potential as a therapeutic target.
SUBMITTER: Zhou Y
PROVIDER: S-EPMC11327441 | biostudies-literature | 2024 Sep
REPOSITORIES: biostudies-literature
Zhou Yujia Y Pang Nengzhi N Li Wenli W Li Qiuyan Q Luo Jing J Gu Yingying Y Hu Qianrong Q Ding Yi Jie YJ Sun Yan Y Pan Jie J Gao Mengqi M Xiao Ying Y Ma Sixi S Hao Yanxu Y Xing Huichun H Fang Evendro Fei EF Ling Wenhua W Zhang Zhenfeng Z Yang Lili L
Redox biology 20240722
<h4>Background & aims</h4>Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) has long been recognized as an adipokine. However, the exact role of eNAMPT in alcoholic liver disease (ALD) and its relevance to brown adipose tissue (BAT) remain largely unknown. This study aimed to evaluate the impact of eNAMPT on liver function and the underlying mechanisms involved in BAT-Liver communication.<h4>Methods</h4>Serum eNAMPT levels were detected in the serum of both ALD patients and mice. Chr ...[more]