Xie F, Chen R, Zhao J, Xu C, Zan C, Yue B, Tian W, Yi W. Cell cycle kinase CHEK2 in macrophages alleviates the inflammatory response to Staphylococcus aureus-induced pneumonia.
Exp Lung Res 2022;
48:53-60. [PMID:
35075953 DOI:
10.1080/01902148.2022.2029625]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND
Excessive macrophage-mediated inflammation participates in the development of Staphylococcus aureus (S. aureus)-induced pneumonia. Checkpoint kinase 2 (Chek2) was screened out as macrophage-related infantile pneumonia gene after the differentially expressed analysis of RNAseq data derived from pam3CSK4 stimulated bone marrow-derived macrophages (BMDMs).
METHODS
RAW264.7 macrophage cells were transfected with Chek2-specific gRNA, which were further overexpressed with wide-type Chek2 or Chek2 kinase activity mutant (Chek2 KD, D368N). At the same time, the relative protein and mRNA expression of inflammatory cytokines were determined. C57BL/6J WT mice were intranasally infected with S. aureus to induce S. aureus-induced pneumonia, which was treated with BML-277, an inhibitor of Chek2. The symptoms of pneumonia mice and inflammatory cytokines associated with the nuclear factor kappa B (NF-κB) signaling pathways were further examined.
RESULTS
In vivo, BML-277 significantly promoted pneumonia symptoms, including mortality, lung infiltration of immune cells, and the abundance of lung pro-inflammatory cytokines. Mechanically, BML-277 did not affect BMDMs survival but up-regulated the mRNA expression of tumor necrosis factor (Tnf), nitric oxide synthase 2 (Nos2), interleukin (Il)23a, and the secretion of Tnf-α and Il-23a. At the same time, genetic complementation experiment testified that Chek2 KD did not inhibit NF-κB and relevant inflammatory cytokines expression.
CONCLUSION
Chek2 functions through the kinase mechanism to down-regulate the NF-κB pathway in macrophages to alleviate S. aureus-induced pneumonia in mice.
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