LPS-induced macrophage HMGB1-loaded extracellular vesicles trigger hepatocyte pyroptosis by activating the NLRP3 inflammasome

  • Cell Death Discov. 2021 Nov 6;7(1):337. doi: 10.1038/s41420-021-00729-0.
Guozhen Wang  #  1  2 ,  Siyi Jin  #  2  3 ,  Weichang Huang  #  1  2 ,  Yang Li  2  3 ,  Jun Wang  2  3 ,  Xuguang Ling  1 ,  Yun Huang  2  3 ,  Ye Hu  2  3 ,  Congcong Li  2 ,  Ying Meng  4 ,  Xu Li  5  6
Affiliations
  • 1. Department of Emergency Medicine, Nanfang Hospital, Southern Medical University, 510515, Guangzhou, China.
  • 2. State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, 510515, Guangzhou, Guangdong, China.
  • 3. Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
  • 4. Department of Respiratory Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China. [email protected].
  • 5. Department of Emergency Medicine, Nanfang Hospital, Southern Medical University, 510515, Guangzhou, China. [email protected].
  • 6. State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, 510515, Guangzhou, Guangdong, China. [email protected].
  • # Contributed equally.
PMID: 34743181 DOI: 10.1038/s41420-021-00729-0
Abstract

Extracellular vesicles (EVs) have emerged as important vectors of intercellular dialogue. High mobility group box protein 1 (HMGB1) is a typical damage-associated molecular pattern (DAMP) molecule, which is cytotoxic and leads to cell death and tissue injury. Whether EVs are involved in the release of HMGB1 in lipopolysaccharide (LPS)-induced acute liver injuries need more investigation. EVs were identified by transmission electron microscopy, nanoparticle tracking analysis (NTA), and western blotting. The co-localization of HMGB1, RAGE (receptor for advanced glycation end-products), EEA1, Rab5, Rab7, Lamp1 and transferrin were detected by confocal microscopy. The interaction of HMGB1 and RAGE were investigated by co-immunoprecipitation. EVs were labeled with the PKH67 and used for uptake experiments. The pyroptotic cell death was determined by FLICA 660-YVAD-FMK. The expression of NLRP3 (NOD-like Receptor family pyrin domain containing 3) inflammasomes were analyzed by western-blot or immunohistochemistry. Serum HMGB1, ALT (alanine aminotransferase), AST (aspartate aminotransferase), LDH (Lactate Dehydrogenase) and MPO (myeloperoxidase) were measured using a commercial kit. The extracellular vesicle HMGB1 was detected in the serums of sepsis patients. Macrophages were found to contribute to HMGB1 release through the EVs. HMGB1-RAGE interactions participated in the loading of HMGB1 into the EVs. These EVs shuttled HMGB1 to target cells by transferrin-mediated endocytosis leading to hepatocyte Pyroptosis by the activation of NLRP3 inflammasomes. Moreover, a positive correlation was verified between the sepsis serum EVs-HMGB1 level and clinical liver damage. This finding provides insights for the development of novel diagnostic and therapeutic strategies for acute liver injuries.