S100A9 Blockade Prevents Lipopolysaccharide-induced Lung Injury Via Suppressing the NLRP3 Pathway
Overview
Affiliations
Background: S100 calcium binding protein A9 (S100A9) is a pro-inflammatory alarmin associated with several inflammation-related diseases. However, the role of S100A9 in lung injury in sepsis has not been fully investigated. Therefore, the present study aimed to determine the role of S100A9 in a lipopolysaccharide (LPS)-induced lung injury murine model and its underlying molecular mechanisms.
Methods: LPS was utilized to induce sepsis and lung injury in C57BL/6 or NOD-like receptor family pyrin domain containing 3 (NLRP3) mice. To investigate the effects of S100A9 blockade, mice were treated with a specific inhibitor of S100A9. Subsequently, lung injury and inflammation were evaluated by histology and enzyme‑linked immunosorbent assay (ELISA), respectively. Furthermore, western blot analysis and RT-qPCR were carried out to investigate the molecular mechanisms underlying the effects of S100A9.
Results: S100A9 was upregulated in the lung tissues of LPS-treated mice. However, inhibition of S100A9 alleviated LPS-induced lung injury. Additionally, S100A9 blockade also attenuated the inflammatory responses and apoptosis in the lungs of LPS-challenged mice. Furthermore, the increased expression of NLRP3 was also suppressed by S100A9 blockade, while S100A9 blockade had no effect on NLRP3 mice. In vitro, S100A9 downregulation mitigated LPS-induced inflammation. Interestingly, these effects were blunted by NLRP3 overexpression.
Conclusion: The results of the current study suggested that inhibition of S100A9 could protect against LPS-induced lung injury via inhibiting the NLRP3 pathway. Therefore, S100A9 blockade could be considered as a novel therapeutic strategy for lung injury in sepsis.
Ismail R, Habib H, Anter A, Amin A, Heeba G Front Pharmacol. 2025; 16:1528978.
PMID: 39917614 PMC: 11798997. DOI: 10.3389/fphar.2025.1528978.
Sun C, Xie Y, Zhu C, Guo L, Xu B, Qin H PeerJ. 2024; 12:e18718.
PMID: 39686985 PMC: 11648679. DOI: 10.7717/peerj.18718.
Immunological mechanisms in steatotic liver diseases: An overview and clinical perspectives.
Yan M, Man S, Ma L, Guo L, Huang L, Gao W Clin Mol Hepatol. 2024; 30(4):620-648.
PMID: 38988278 PMC: 11540396. DOI: 10.3350/cmh.2024.0315.
Sun C, Xie Y, Zhu C, Guo L, Wei J, Xu B J Inflamm Res. 2024; 17:2939-2949.
PMID: 38764498 PMC: 11100500. DOI: 10.2147/JIR.S457547.
Kang Z, Huang Q, Zhen N, Xuan N, Zhou Q, Zhao J Front Immunol. 2024; 15:1382449.
PMID: 38745657 PMC: 11092984. DOI: 10.3389/fimmu.2024.1382449.