Therapeutic manipulation of the neutrophil clock

• Autores: Alejandra Aroca Crevillén
• Directores de la Tesis: Andrés Hidalgo Alonso (dir. tes.)
• Lectura: En la Universidad Autónoma de Madrid ( España ) en 2024
• Idioma: inglés
• Número de páginas: 139
• Títulos paralelos:
  • Manipulación terapéutica del reloj circadiano de neutrófilos
• Enlaces
  • Tesis en acceso abierto en: Biblos-e Archivo
• Resumen

  • Neutrophils are critical drivers of vascular inflammation, as seen during ischemic or vasoocclusive events (1, 2). However, targeting neutrophils has not been a therapeutic option because unspecific inhibition compromises anti-microbial defense. The discovery of a cell-intrinsic clock that controls the circadian properties of neutrophils (3) suggested that inflammatory diseases that follow circadian patterns might be driven by this clock, thereby unveiling potential strategies to alleviate inflammation without compromising immune defense. Because CXCR4 is a key negative regulator of this circadian clock, in this thesis we examined whether this receptor could be targeted to interfere with circadian programs in neutrophils, and to prevent the deleterious consequences of neutrophils in vascular inflammation without interfering with immune protection.

    Through in vivo and ex vivo assays, including multiparametric cytometry, migration assays, single-cell transcriptomics, infection models and 4D intravital microscopy, we found that genetic and pharmacologic activation of CXCR4 increased neutrophil migration during inflammation but critically reduced pathogenic “behaviors” within inflamed vessels, without altering the immune response against bacterial or fungal infections. Using a model of ischemia/reperfusion injury after ligation of the coronary artery (acute myocardial infarction or AMI), we found that the degree of cardiac damage displayed diurnal variations in mice, which were lost in mice with disruption of the neutrophil clock (Bmal1ΔN and CXCR4WHIM mice). Consistent with our model, administration of a commercial agonist for CXCR4 (ATI-2341), or custom-designed CXCR4 agonists (peptides P1-P3), dramatically blunted cardiac injury during AMI and preserved vascular flow in a mouse model of sickle cell disease. Notably, this protective effect was lost in mice with neutrophil-specific deficiency in CXCR4 (CXCR4ΔN mice), indicating that protection was through specific targeting of the receptor in neutrophils. Determination of neutrophil distribution in skin wounds and infarcted hearts suggested that activation of CXCR4 limited the localization of neutrophils to the site of injury, thereby preventing damage to adjacent areas. Our data demonstrate that the circadian clock of neutrophils can be targeted therapeutically to manipulate the temporal properties of neutrophils and to protect from cardiovascular disease