[Iron overload impairs mitochondrial function, induces neutrophil aging, inhibits its bactericidal ability, and exacerbates mouse peritonitis].

Objective To explore the effects of iron overload on neutrophil function and peritonitis, as well as the possible mechanisms. Methods C57BL/6 mice were randomly divided into a control group and an iron overload group (10 mice in each group). Acute peritonitis model was induced by intraperitoneal injection of E.coli. The iron deposition in liver and spleen was assessed using H&E staining and the iron level in neutrophils was quantified by colorimetric analysis. The proportion and morphology of neutrophils were evaluated by blood cell counting plate and MGG staining, and the cellular aging of neutrophils was determined by senescence-associated β-galactosidase (SA-β-Gal) staining. The protein expression levels of P16 in neutrophils was detected using Western blot analysis and the bactericidal function of neutrophils was detected by LB smears. The mitochondrial membrane potential and mitochondrial function of neutrophils were detected by JC-1 staining and ATP kit, respectively. Results Compared with the control group, mice in the iron overload group exhibited following effects, including significantly higher iron content in the liver and spleen, a shorter survival time, significantly reduced bactericidal ability of neutrophil with no significant differences in the quantity or morphology, aggravated aging in neutrophils (indicated by increased expression of P16 and a higher number of SA-β-Gal positive cells), and decreased mitochondrial membrane potential and ATP levels. Conclusion Iron overload aggravates peritonitis by reducing the bactericidal ability of neutrophils.