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Updated: Aug 12, 2026
Cecal Ligation and Puncture-induced Sepsis as a Model To Study Autophagy in Mice
Published on: February 9, 2014
[LCN2 knockout protects endothelial barrier function in mice with sepsis-induced acute lung injury by regulating the
Mengjie Yu1,2, Anbo Zhao1,2, Yixuan Hao1,2
1Department of Physiology, Bengbu Medical University, Bengbu 233030, China.
Objectives:
To investigate the protective effect of lipocalin-2 (LCN2) gene knockout against sepsis-induced acute lung injury (ALI) and vascular endothelial dysfunction in mice and the mediating role of the nuclear factor-κB (NF-κB) signaling pathway.
Methods:
Wild-type (WT) C57BL/6 mice receiving sham operation or cecal ligation and puncture (CLP) to induce sepsis were randomized into 3 subgroups for intraperitoneal injections of saline, PDTC, or Bay 11-7082 (n=10). Twenty LCN2 knockout (LCN2KO) mice were randomized for sham operation or CLP modeling. Pulmonary histopathological changes, lung wet-to-dry (W/D) ratio, lung index, Evans blue extravasation, and serum TNF-α and IL-6 levels in the mice were assessed. The colocalization of NF-κB, ICAM-1, and VCAM-1 with CD31 were analyzed using immunofluorescence staining, and endothelial cell apoptosis was examined with TUNEL/CD31 double staining. Western blotting and co-immunoprecipitation assay were performed to analyze the protein expressions of LCN2, p-P65/P65, ICAM-1, VCAM-1 and VE-cadherin and the interaction between LCN2 and P65.
Results:
The WT mice receiving CLP showed severe lung structural damage with obvious edema and inflammation. In contrast, both the LCN2KO mouse and PDTC-treated WT mouse models of CLP showed milder lung injury with lower W/D ratio, lung index, Evans blue leakage, serum TNF‑α and IL-6 levels and markedly reduced colocalization signals of NF-κB, ICAM-1, and VCAM-1 with CD31. CLP resulted in significantly increased expression levels of LCN2, p-P65/P65, ICAM-1, and VCAM-1, lowered VE-cadherin levels, and enhanced endothelial cell apoptosis, and all these changes were significantly ameliorated in LCN2KO mice and WT mice with NF‑κB inhibitor treatment. Co-immunoprecipitation results suggested the interaction between lung LCN2 and P65. Bay 11-7082 significantly reduced inflammatory cytokine production, downregulated p-P65 expression and its downstream adhesion molecules, and restored VE-cadherin expression.
Conclusions:
LCN2 knockout alleviates sepsis-induced ALI and vascular endothelial dysfunction in mice by inhibiting NF-κB signaling.
