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Updated: Jul 13, 2026
Evaluation of a Reliable Biomarker in a Cecal Ligation and Puncture-Induced Mouse Model of Sepsis
Published on: December 9, 2022
Peroxynitrite mediates the failure of neutrophil migration in severe polymicrobial sepsis in mice
D Torres-Dueñas1, M R N Celes, A Freitas
1Department of Pharmacology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Avenida Bandeirantes, 3900, Ribeirão Preto, São Paulo, Brazil.
Background And Purpose:
Sepsis is a systemic inflammatory response resulting from the inability of the host to restrict local infection. The failure of neutrophil migration to the infection site is one of the mechanisms involved in this process. Recently, it was demonstrated that this event is mediated by nitric oxide (NO). The present study addresses the possibility that peroxynitrite (ONOO(-)), a NO-derived powerful oxidizing and nitrating compound, could also be involved in neutrophil migration failure.
Experimental Approach:
Male C57Bl/6 mice were subjected to moderate (MSI) or severe (SSI) septic injury, both induced by cecal ligation and puncture (CLP). The leukocyte rolling and adhesion in the mesentery was evaluated by intravital microscopy. Cytokines (TNF-alpha and MIP-1alpha) were measured by ELISA and 3-nitrotyrosine (3-NT) by immunofluorescence.
Key Results:
Compared with saline pretreatment of SSI mice, pre-treatment with uric acid, a ONOO(-) scavenger, partially restored the failure of neutrophil rolling, adhesion and migration to the site of infection. These mice also presented low circulating bacterial counts and diminished systemic inflammatory response. Pretreatment with uric acid reduced 3-NT labelling in leukocytes in mesenteric tissues and in neutrophils obtained from peritoneal exudates. Finally, uric acid pretreatment enhanced significantly the survival rate in the SSI mice. Similarly, treatment with FeTPPs, a more specific ONOO(-) scavenger, re-established neutrophil migration and increased mice survival rate.
Conclusions And Implications:
These results indicate that ONOO(-) contributed to the reduction of neutrophil/endothelium interaction and the consequent failure of neutrophil migration into infection foci and hence susceptibility to severe sepsis.
Insights
Peroxynitrite (ONOO(-)) contributes to neutrophil migration failure during severe sepsis. Scavenging ONOO(-) with uric acid or FeTPPs restored neutrophil function and improved survival rates in septic mice.
Area of Science:
- Immunology
- Pathophysiology
- Biochemistry
Background:
- Sepsis involves a systemic inflammatory response due to uncontrolled local infection.
- Neutrophil migration failure is a key mechanism in sepsis pathogenesis.
- Nitric oxide (NO) mediates neutrophil migration, but the role of its derivative, peroxynitrite (ONOO(-)), is unclear.
Purpose of the Study:
- To investigate the involvement of peroxynitrite (ONOO(-)) in neutrophil migration failure during sepsis.
- To determine if scavenging ONOO(-) can ameliorate sepsis-induced neutrophil dysfunction and improve outcomes.
Main Methods:
- Male C57Bl/6 mice underwent cecal ligation and puncture (CLP) to induce moderate (MSI) or severe (SSI) sepsis.
- Leukocyte rolling and adhesion were assessed using intravital microscopy.
- Cytokines (TNF-alpha, MIP-1alpha) and 3-nitrotyrosine (3-NT) levels were measured.
Main Results:
- Uric acid, an ONOO(-) scavenger, partially restored neutrophil migration and reduced bacterial load in SSI mice.
- ONOO(-) scavenging decreased 3-NT labeling in leukocytes and peritoneal neutrophils.
- Treatment with uric acid or FeTPPs (another ONOO(-) scavenger) significantly enhanced survival rates in SSI mice.
Conclusions:
- ONOO(-) plays a significant role in reducing neutrophil-endothelium interactions during sepsis.
- This interaction failure leads to impaired neutrophil migration into infection sites, increasing sepsis severity.
- Targeting ONOO(-) represents a potential therapeutic strategy for severe sepsis.
