From June 5 to 8, 2024, the European Association for the Study of the Liver (EASL) Annual Meeting was successfully held in Milan, Italy. During the conference, Professor Liang Peng's team from the Third Affiliated Hospital ,Sun Yat-sen University unveiled the significant link between hepatocyte pyroptosis and acute-on-chronic liver failure (ACLF). The research found that IL-1β released from pyroptotic hepatocytes activates the IL1R1/MyD88/TBK1 pathway in neutrophils, promoting the formation of neutrophil extracellular traps (NETs) and exacerbating liver injury. Through bioinformatics analysis, mouse model experiments, and clinical patient data validation, the team confirmed this mechanism and identified IL-1R1 and MyD88 as potential therapeutic targets for ACLF. This discovery provides new perspectives and strategies for the treatment of ACLF.Research Background and Objectives
ACLF is characterized by hepatocyte necrosis and systemic inflammation, particularly significant neutrophil infiltration in the liver. Currently, there are no specific treatments for ACLF, and the role of neutrophils in ACLF is not well understood. Our research aims to elucidate the role of neutrophils in ACLF to understand the disease mechanism better and identify potential therapeutic targets.
Research Methods
The study involved bioinformatics analysis of four ACLF-related datasets retrieved from the Gene Expression Omnibus (GEO) database. A mouse model of ACLF was constructed, and Bulk-RNA sequencing of mouse liver tissues was performed for further confirmation. IL-1R1 knockout mice were used to validate the in vivo role of IL-1R1. In vitro, recombinant IL-1β was used to stimulate neutrophils, and neutrophil-hepatocyte co-culture was conducted to verify the role of neutrophils. Co-immunoprecipitation (Co-IP) was used to explore the molecular mechanism. Finally, the expression levels of related molecules in the serum and neutrophils of ACLF patients and healthy individuals were validated, and their correlation with the 28-day mortality of ACLF patients was explored.
Research Results
Bioinformatics analysis indicated high expression of IL-1-related pathways in the peripheral blood of ACLF patients, which was also confirmed by Bulk-RNA sequencing of mouse liver tissues. ACLF mice exhibited significant GSDME/caspase3-mediated hepatocyte pyroptosis, increased neutrophil infiltration, and elevated peripheral blood inflammatory and chemokine levels. IL-1R1 knockout mice showed significantly reduced hepatocyte pyroptosis and neutrophil infiltration, with decreased peripheral blood inflammatory and chemokine levels. In vitro, sh-IL1R1 neutrophils exposed to IL-1β showed reduced ROS levels, NET formation, chemokine release, and cytotoxicity. Co-IP results indicated that IL-1β acting on IL1-R1 led to MyD88 interacting with TBK1, mediating NET formation and promoting interferon-beta (IFNB) transcription. IFNB induced mitochondrial oxidative stress in neutrophils, mediating hepatocyte damage.
Additionally, the MyD88 inhibitor (ST2825) significantly improved liver injury and neutrophil aggregation in ACLF mice. Compared to healthy individuals, ACLF patients had significantly elevated serum levels of IL-1, soluble IL-1R1, IL-18, CXCL-1, and CXCL-2, with increased expression of IL-1R1, MyD88, MPO, and CD177 in neutrophils. Serum soluble IL-1R1 was identified as a risk factor for 28-day mortality in ACLF patients.
Research Conclusion
In ACLF, hepatocyte pyroptosis releases IL-1β, which activates the IL1R1/MyD88/TBK1 pathway, mediating ROS production, NET formation, and chemotaxis in neutrophils, thereby exacerbating liver injury. IL-1R1 and MyD88 are potential therapeutic targets for ACLF.
Expert Profile
Professor Liang Peng
- Professor/Chief Physician, Department of Infectious Diseases, Third Affiliated Hospital of Sun Yat-sen University
- Doctor of Medicine, Ph.D. Supervisor
- Deputy Director, Guangdong Provincial Key Laboratory of Liver Disease Research
- Assistant to the President, Third Affiliated Hospital of Sun Yat-sen University
- Chairman, Medical Ethics Committee, Third Affiliated Hospital of Sun Yat-sen University
- First “Outstanding Young Medical Talent in Guangdong Province”
- First “Excellent Young Teacher of Sun Yat-sen University”
- Member, Chinese Medical Association Virology Branch
- Deputy Leader, Hepatic Failure and Artificial Liver Group, Chinese Medical Association Infectious Diseases Branch
- Deputy Chairman, Youth Committee of the Chinese Medical Doctor Association Infectious Diseases Branch
- Youth Committee Member, Chinese Medical Association Infectious Diseases Branch
- Deputy Chairman, Stem Cell Translational Medicine Branch of the Chinese Society of Anatomy
- Chairman, Infectious Diseases Branch of the Guangdong Provincial Preventive Medicine Association
- Standing Committee Member, Infectious Diseases Branch of the Guangdong Medical Association
Main Research Directions:
- Mechanisms and treatment of liver failure
- Mechanisms and treatment of stem cells and artificial liver
- Genetic and protein mechanisms and treatment of chronic hepatitis B
Publications:
- Over 80 papers published
- First/co-first author and corresponding/co-corresponding author of more than 40 SCI papers in journals such as Hepatology, Clin Microbiol Infect, Cell Death & Disease
Grants:
- Principal Investigator of five projects funded by the National Natural Science Foundation of China
- Principal Investigator of more than ten provincial and ministerial-level research grants
