Mitofusin-2 regulates leukocyte adhesion through the maturation of beta2 integrin activation in differentiation

Abstract

Abstract Neutrophils are critical in inflammation and innate immunity. Neutrophil adhesion to vascular endothelium is a crucial step in neutrophil recruitment. Mitofusin-2 is required for neutrophil adhesion, but molecular details are unclear. Here, we demonstrated that β2-integrin-mediated slow-rolling and arrest, but not PSGL-1-mediated cell rolling, are defective in mitofusin-2-deficient neutrophil-like HL60 cells. This adhesion defect is associated with reduced expression of fMLP receptors and β2 integrins as well as the inhibited β2 integrin activation, as assessed by conformational-specific antibodies. Mitofusin-2 deficiency limited the maturation of β2 integrin activation during the neutrophil-directed differentiation of HL60 cells, which is indicated by identified markers CD35 and CD87. Reversed to results in overall HL60 cells, mitofusin-2 knockdown in β2-integrin-activation-matured cells (CD87high population) enhanced integrin activation. Our study illustrates the function of mitofusin-2 in leukocyte adhesion and may provide new insights into the development and treatment of mitofusin-2-deficiency-related disease.