Insulin treatment alters phagocytic activity.

A) Latex beads conjugated with FITC-IgG (green) were incubated for 4 hours with BV2 cells (DAPI nuclear stain–blue) exposed to control conditions, insulin, LPS, or LPS + insulin (representative images). B) Quantitation of phagocytosed beads demonstrated that insulin alone led to a significant reduction in phagocytosis activity at 28 hours (24 hour incubation with stimulation, 4 hour incubation with beads), which was further reduced by LPS stimulation. Addition of insulin to the LPS treated group partially alleviated this suppression, significantly increasing phagocytosis in comparison to the LPS group. n = 5/group. C) Vybrant phagocytosis assay performed 3 hours after stimulation (2 hours with phagocytic material), showed that acute insulin administration significantly increased phagocytosis. Similar to the longer condition, LPS reduced phagocytosis, which was reversed by insulin administration. TNFa, on the other hand, significantly increased phagocytosis, which was reversed by insulin. N = 3/group. Bars are mean +/- SEM. *p<0.05, **p<0.01, ****p<0.0001. Size bar = 50μm.