TLR3-mediated NET formation and macrophage activation in acute liver failure: Targeting IL-36 signaling to attenuate inflammatory drivers

  • Int Immunopharmacol. 2025 Aug 28:161:115112. doi: 10.1016/j.intimp.2025.115112.
Zhi-Hong Zhang  1 Hong-Xu Yang  2 Jun-Liang Yang  1 Xue-Li Jiang  1 Si-Qi Wang  1 Yan-Ling Wu  1 Zi-Ying Zhan  3 Ji-Xing Nan  4 Li-Hua Lian  5
Affiliations
  • 1. Key Laboratory of Traditional Chinese Korean Medicine Research of State Ethnic Affairs Commission, College of Pharmacy, Yanbian University, Yanji, Jilin Province 133002, China; Key Laboratory of Natural Medicines of the Changbai Mountain, Ministry of Education, College of Pharmacy, Yanbian University, Yanji, Jilin Province 133002, China.
  • 2. Longgang Central Hospital, 6082 longgang Road, Shenzhen, Guangdong Province 518116, China.
  • 3. Key Laboratory of Traditional Chinese Korean Medicine Research of State Ethnic Affairs Commission, College of Pharmacy, Yanbian University, Yanji, Jilin Province 133002, China; Key Laboratory of Natural Medicines of the Changbai Mountain, Ministry of Education, College of Pharmacy, Yanbian University, Yanji, Jilin Province 133002, China. Electronic address: [email protected].
  • 4. Key Laboratory of Traditional Chinese Korean Medicine Research of State Ethnic Affairs Commission, College of Pharmacy, Yanbian University, Yanji, Jilin Province 133002, China; Key Laboratory of Natural Medicines of the Changbai Mountain, Ministry of Education, College of Pharmacy, Yanbian University, Yanji, Jilin Province 133002, China. Electronic address: [email protected].
  • 5. Key Laboratory of Traditional Chinese Korean Medicine Research of State Ethnic Affairs Commission, College of Pharmacy, Yanbian University, Yanji, Jilin Province 133002, China; Key Laboratory of Natural Medicines of the Changbai Mountain, Ministry of Education, College of Pharmacy, Yanbian University, Yanji, Jilin Province 133002, China. Electronic address: [email protected].
Abstract

Background: Acute liver failure (ALF), characterized by inflammation-mediated hepatocyte dysfunction, poses a significant global health burden. Although neutrophils and macrophages are central to driving inflammatory responses in ALF, the molecular mechanisms governing IL-36-driven inflammation in Toll-like Receptor 3 (TLR3)-mediated NETosis and macrophage activation remain poorly understood. This study systematically delineates wherein TLR3 activation induces IL-36 hyperactivation and NETosis, which cooperatively trigger macrophage activation to accelerate ALF progression.

Methods: First, the role of IL-36 signaling was evaluated in the TLR3-provoked mouse peritoneal macrophages (MPMs) and murine bone-derived macrophages (BMDMs) in vitro. Further, the murine model of ALF was established with polyinosinic-polycytidylic acid (Poly(I:C))/D-GalN and acute ethanol gavage in Il1rl2-deficient mice generated by lentivirus-mediated shRNA, and the released NETs were evaluated with immunoblotting and immunofluorescence staining.

Results: We observed Poly(I:C), the specific ligand of TLR3, when combined with extracellular ATP, provoked the IL-36 signaling and the release of IL-1β in macrophages. In contrast, Il36g deficiency reduced the secretion of proinflammatory cytokines, such as IL-1β and HMGB1, upon macrophage activation. While Poly(I:C)/D-GalN or binge ETOH-induced ALF in mice was accompanied by the enhanced level of IL-36γ and NET formation, IL-36R knockdown reversed the liver damage by decreasing the expressions of proinflammatory cytokines and chemokines, reducing the lipid accumulation and preventing the NET formation as well.

Conclusion: Our study demonstrates that TLR3-mediated NET formation was enhanced in ALF, and this process was tightly regulated by IL-36 signaling. These findings suggest that targeting IL-36 represents a potential therapeutic target for modulating inflammation in ALF.

Keywords
Acute liver failure; IL-36 signaling; Macrophage activation; NETosis; TLR3 pathway.
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