2. Academic Validation
  3. GCN2 activates macrophage autophagy to inhibit NLRP3 inflammasome-mediated acute lung injury

GCN2 activates macrophage autophagy to inhibit NLRP3 inflammasome-mediated acute lung injury

  • Int Immunopharmacol. 2026 Jan 1;168(Pt 1):115785. doi: 10.1016/j.intimp.2025.115785.
Yun Xie 1,  Xiao Chen 2,  Xinji Gong 1,  Huamei Chen 3,  Sicheng Xu 4
Affiliations

Affiliations

  • 1 Department of Respiratory Intensive Care Unit, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China.
  • 2 Department of Respiratory Medicine, Tai'an City Central Hospital, Tai'an, Shandong, China.
  • 3 Department of Pulmonary and Critical Care Medicine, Changsha Central Hospital, Changsha, Hunan, China.
  • 4 Department of Respiratory Intensive Care Unit, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China. Electronic address: [email protected].
PMID: 41176906 DOI: 10.1016/j.intimp.2025.115785
Abstract

Background: Acute lung injury (ALI) is a life-threatening respiratory condition. This study aimed to investigate the role of general control nonderepressible 2 (GCN2) in lipopolysaccharide (LPS)-induced ALI models.

Methods: Mice were intratracheally administered adeno-associated virus-delivered GCN2 14 days before LPS challenge. Lung histopathology was evaluated using hematoxylin and eosin staining, pro-inflammatory cytokines in the bronchoalveolar lavage fluid were measured using enzyme-linked immunosorbent assay, and protein expression in lung tissues was analyzed using western blotting. NLR family pyrin domain-containing 3 (NLRP3) inflammasome components and autophagy-related proteins were assessed using immunohistochemical staining and western blotting. Moreover, RAW264.7 cells were transfected with the GCN2 overexpression vector and subsequently subjected to quantitative real-time polymerase chain reaction, western blotting, and immunofluorescence staining to examine alterations in inflammatory responses and Autophagy.

Results: GCN2 was downregulated in the macrophages of ALI mice compared to controls. Overexpression of GCN2 in mice alleviated lung histopathological injury, decreased lung wet/dry weight ratio and myeloperoxidase activity, and reduced the levels of pro-inflammatory cytokines. Moreover, GCN2 overexpression increased the expression of light chain 3-II, autophagy-related gene 5, and Beclin1. However, it decreased the expression of NLRP3, cleaved Caspase-1, PYD and CARD domain-containing proteins, as well as the N-terminal domain of gasdermin D. The regulatory effects of GCN2 on inflammation and Autophagy were validated in RAW264.7 cells. Treatment of mice or RAW264.7 cells with 3-methyladenine, an inhibitor of Autophagy, effectively reversed the anti-inflammatory action of GCN2.

Conclusion: GCN2 overexpression in macrophages in ALI models attenuated NLRP3-mediated inflammation by inducing Autophagy activation.

Keywords

Acute lung injury; Autophagy; GCN2; NLRP3 inflammasome.

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