BDKRB1 activation induces CXCR2 desensitization in neutrophils during severe sepsis and exacerbates disease severity
Raquel Duque do Nascimento Arifa, Carolina Braga Resende Mascarenhas, Lívia Caroline Resende Rossi, Maria Eduarda Freitas Silva, Larissa M. Lucas, João Paulo Pezzini Barbosa, Daiane Boff, Brenda Gonçalves Resende, Lívia Duarte Tavares, Alesandra Corte Reis, Vanessa Pinho, Flavio Almeida Amaral, Caio Tavares Fagundes, Cristiano Xavier Lima, Mauro Martins Teixeira, Daniele G Souza
Raquel Duque do Nascimento Arifa, Carolina Braga Resende Mascarenhas, Lívia Caroline Resende Rossi, Maria Eduarda Freitas Silva, Larissa M. Lucas, João Paulo Pezzini Barbosa, Daiane Boff, Brenda Gonçalves Resende, Lívia Duarte Tavares, Alesandra Corte Reis, Vanessa Pinho, Flavio Almeida Amaral, Caio Tavares Fagundes, Cristiano Xavier Lima, Mauro Martins Teixeira, Daniele G Souza
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Research Article Inflammation Microbiology

BDKRB1 activation induces CXCR2 desensitization in neutrophils during severe sepsis and exacerbates disease severity

Abstract

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. During early sepsis, kinins are released and bind to B1 (BDKRB1) and B2 (BDKRB2) bradykinin receptors, but the involvement of these receptors in sepsis remains incompletely understood. This study demonstrated that the genetic deletion of Bdkrb2 had no significant impact on sepsis induced by cecal ligation and puncture (CLP) compared to wild-type (WT) mice. In contrast, Bdkrb1−/− mice subjected to CLP exhibited decreased lethality and bacterial load, associated with an increased influx of neutrophils into the peritoneal cavity, compared with WT mice. Neutrophils from CLP-Bdkrb1−/− mice partially restored CXCR2 expression and reduced the upregulation of P110γ observed in WT CLP neutrophils. Pharmacologic inhibition of BDKRB1 combined with imipenem treatment substantially improved survival compared with antibiotic therapy alone. In human neutrophils, stimulation with LPS led to the upregulation of BDKRB1 expression, and antagonism of BDKRB1 restored neutrophil migration in response to CXCL8. These findings identify BDKRB1 as an important modulator of neutrophil dysfunction in sepsis and a promising therapeutic target whose inhibition improves bacterial clearance, restores neutrophil migration, and increases the efficacy of antibiotic treatment.

Authors

Raquel Duque do Nascimento Arifa, Carolina Braga Resende Mascarenhas, Lívia Caroline Resende Rossi, Maria Eduarda Freitas Silva, Larissa M. Lucas, João Paulo Pezzini Barbosa, Daiane Boff, Brenda Gonçalves Resende, Lívia Duarte Tavares, Alesandra Corte Reis, Vanessa Pinho, Flavio Almeida Amaral, Caio Tavares Fagundes, Cristiano Xavier Lima, Mauro Martins Teixeira, Daniele G Souza

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Figure 2

Absence of BDKRB1 prevents lung inflammation and injury.

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Absence of BDKRB1 prevents lung inflammation and injury. (A) Lung sectio...
(A) Lung sections were stained with H&E for histopathologic analysis, and (B) tissue damage was quantified in 3 sections of each sample to assess capillary congestion, hemorrhage, neutrophil infiltration, and alveolar edema. (C) Neutrophil influx was determined by quantification of MPO activity. (D) CXCL1 and (E) TNF concentration in the lung was determined by ELISA. Experiments were replicated at least twice, and 1 representative experiment is presented in the figure. Results are expressed as mean ± SEM of at least 4 animals per group. ANOVA followed by Tukey’s multiple comparisons posttest was used for data with a normal distribution. For data that did not follow a normal distribution, the Kruskal-Wallis test followed by Dunn’s multiple comparisons posttest was applied to compare 3 or more independent groups. *, P < 0.05, compared with the sham group; #, P < 0.05, compared with WT mice subjected to CLP.