a-flow-cytometry-based-high-throughput-technique-for-screening

A Flow Cytometry-Based High-Throughput Technique for Screening Integrin-Inhibitory Drugs

This protocol aims to establish a method for identifying small molecular antagonists of &#946;2 integrin activation, utilizing ...

Uconn Health

Neutrophils are the most abundant leukocyte in human blood. They are critical for fighting infections and are involved in inflammatory diseases. Mitochondria are indispensable for eukaryotic cells, as they control the biochemical processes of respiration and energy production. Mitochondria in neutrophils have been underestimated since glycolysis is a major metabolic pathway for fuel production in neutrophils. However, several studies have shown that mitochondria are greatly involved in multiple neutrophil functions as well as neutrophil-related diseases. In this review, we focus on how mitochondrial components, metabolism, and related genes regulate neutrophil functions and relevant diseases.

Roles of mitochondria in neutrophils.

Neutrophils are critical for mediating inflammatory responses. Inhibiting neutrophil recruitment is an attractive approach for preventing inflammatory injuries, including myocardial ischemia-reperfusion (I/R) injury, which exacerbates cardiomyocyte death after primary percutaneous coronary intervention in acute myocardial infarction. In this study, we found out that a neutrophil exocytosis inhibitor Nexinhib20 inhibits not only exocytosis but also neutrophil adhesion by limiting β integrin activation. Using a microfluidic chamber, we found that Nexinhib20 inhibited IL-8-induced β integrin-dependent human neutrophil adhesion under flow. Using a dynamic flow cytometry assay, we discovered that Nexinhib20 suppresses intracellular calcium flux and β integrin activation after IL-8 stimulation. Western blots of Ras-related C3 botulinum toxin substrate 1 (Rac-1)-GTP pull-down assays confirmed that Nexinhib20 inhibited Rac-1 activation in leukocytes. An in vitro competition assay showed that Nexinhib20 antagonized the binding of Rac-1 and GTP. Using a mouse model of myocardial I/R injury, Nexinhib20 administration after ischemia and before reperfusion significantly decreased neutrophil recruitment and infarct size. Our results highlight the translational potential of Nexinhib20 as a dual-functional neutrophil inhibitory drug to prevent myocardial I/R injury.

Article	Year
Roles of mitochondria in neutrophils. Frontiers in immunology\| PubMed ID: 36081497	2022
Nexinhib20 Inhibits Neutrophil Adhesion and β Integrin Activation by Antagonizing Rac-1-Guanosine 5'-Triphosphate Interaction. Journal of immunology (Baltimore, Md. : 1950)\| PubMed ID: 36165184	2022

Ziming Cao

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