DLGAP5 Promotes Acute Liver Injury via Hepatocyte Pyroptosis-Driven Macrophage Metabolic Reprogramming and M1
Xianzhi Liu1, Zhiyuan Chen1, Jun Lin2
1Department of Gastroenterology, Xiang'an Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 361000, China.
Abstract:
Pyroptosis is a novel programmed cell death that exists in inflammatory diseases and methyltransferase-like 3 (METTL3) is a core N6-methyladenosine (m6A) modified methyltransferase that has been shown to regulate cell fate. However, the role of pyroptosis in acute liver injury (ALI) is still unknown and whether it is regulated by m6A modification needs to be elucidated. Here, Mettl3 mutant and Nlrp3 knockout mouse were constructed, CCl4- and TAA-induced ALI models were established and primary cells were isolated, and cell pyroptosis and m6A modification were evaluated. We found that hepatocyte pyroptosis is a key characteristic of ALI, and METTL3-mediated m6A modification was upregulated in hepatocytes during ALI. Inhibition of METTL3-mediated m6A modification alleviated hepatocyte pyroptosis and ALI. Through MeRIP-seq analysis and verification, Dlgap5 was determined as the target of METTL3-mediated m6A modification, which was regulated in an IGF2BP2-dependent manner. Mechanistically, METTL3 can bind to DLGAP5, and then DLGAP5 promoted pyroptosis through NF-κB-dependent NLRP3 inflammasome activation and direct potentiation of inflammasome structure formation and assembly. Mettl3 mutation or AT9283-mediated DLGAP5 inhibition alleviated pyroptosis and ALI. The effects of hepatocyte pyroptosis on cell interaction were then explored and we revealed that NLRP3 inflammasome and interleukin releasing by the GSDMD-N-dependent membrane pores from pyroptotic hepatocytes activated macrophage metabolic reprogramming and M1 polarization, further exacerbating ALI. Nlrp3 deficiency alleviated ALI by suppressing hepatocyte pyroptosis and blocking communication between macrophages and hepatocytes. Our findings indicate the potential mechanisms of ALI from an intercellular communication perspective, and targeted-inhibition of DLGAP5 and -blockade of hepatocyte-macrophage interaction provide promising strategies for ALI treatment.
Insights
Pyroptosis, a programmed cell death, is key in acute liver injury (ALI). METTL3-mediated m6A modification promotes pyroptosis via DLGAP5, exacerbating ALI, but inhibition offers therapeutic potential.
Area of Science:
- Molecular Biology
- Immunology
- Hepatology
Background:
- Pyroptosis is a programmed cell death pathway implicated in inflammatory diseases.
- Methyltransferase-like 3 (METTL3) is crucial for N6-methyladenosine (m6A) modification and cell fate regulation.
- The role of pyroptosis and m6A modification in acute liver injury (ALI) remains unclear.
Purpose of the Study:
- To investigate the role of pyroptosis in ALI.
- To elucidate the involvement of METTL3-mediated m6A modification in ALI pathogenesis.
- To identify molecular targets and intercellular communication pathways in ALI.
Main Methods:
- Construction of Mettl3 mutant and Nlrp3 knockout mice.
- Establishment of CCl4- and TAA-induced ALI models.
- Evaluation of pyroptosis and m6A modification using cell assays, MeRIP-seq, and molecular analyses.
Main Results:
- Hepatocyte pyroptosis is a hallmark of ALI, with upregulated METTL3-mediated m6A modification.
- METTL3 targets DLGAP5, promoting pyroptosis via NLRP3 inflammasome activation and exacerbating ALI.
- Pyroptotic hepatocytes activate macrophages, worsening ALI; inhibiting DLGAP5 or hepatocyte-macrophage interaction shows therapeutic promise.
Conclusions:
- METTL3-mediated m6A modification drives pyroptosis and ALI progression through DLGAP5.
- Intercellular communication between hepatocytes and macrophages is critical in ALI pathogenesis.
- Targeted inhibition of DLGAP5 and blocking hepatocyte-macrophage crosstalk are potential ALI treatment strategies.
