The eNAMPT-Integrin α5β1 Axis Mediates Neutrophil-Endothelial Cell Interactions Driving Inflammation in Ulcerative...

Area of Science:

• Immunology
• Gastroenterology
• Molecular Biology

Background:

• Ulcerative colitis (UC) is a chronic inflammatory bowel disease with increasing global incidence.
• Neutrophil-driven mucosal damage is a hallmark of UC, but the underlying mechanisms are not fully understood.
• Current understanding of pathogenic neutrophil activation in UC is limited, hindering the development of targeted therapies.

Purpose of the Study:

• To elucidate the key signaling axes responsible for pathogenic neutrophil activation in ulcerative colitis.
• To integrate single-cell transcriptomics data with in vivo experimental validation.
• To identify novel therapeutic targets for ulcerative colitis based on neutrophil-endothelial cell interactions.

Main Methods:

• Single-cell transcriptomics was employed to characterize the inflammatory microenvironment in UC.
• Analysis focused on neutrophil functional states and intercellular communication within the UC context.
• The eNAMPT-integrin α5β1 signaling axis was hypothesized and functionally validated in vivo.

Main Results:

• Neutrophils in UC demonstrated aberrant activation and significant NAMPT overexpression.
• Extracellular NAMPT (eNAMPT) was identified as a signaling molecule that binds endothelial integrin α5β1.
• This interaction mediates pathological neutrophil-endothelial cell crosstalk, leading to inflammation and tissue damage.
• Pharmacological blockade of the eNAMPT/integrin α5β1 axis significantly reduced neutrophil infiltration, inflammation, and tissue damage in UC mouse models.

Conclusions:

• The eNAMPT-integrin α5β1 signaling axis represents a newly discovered pathogenic pathway in ulcerative colitis.
• This pathway is crucial for neutrophil-endothelial cell communication in UC.
• Targeting this axis offers a promising strategy for developing precision therapies for ulcerative colitis.