ITGAM induced macrophage M2 polarization through activating
FAK/Akt1/β-catenin signaling
The mechanism that ITGAM mediated M2 polarization in macrophage was
verified by silencing Itgam mRNA, and inhibiting FAK and Akt1
phosphorylation (Figure 5A ). As shown by pre-experiment, we
picked the Itgam siRNA with the highest knockdown efficiency (mean
difference = 77.6%, Supplementary Figure 3 ). After knocking
down Itgam, we observed the decreased phosphorylation of FAK and Akt1,
and reversed the upregulation of phosphorylated GSK-3β, together with
downregulation of β-catenin protein (Figure 5B ). Meanwhile, M2
polarization was greatly attenuated after Itgam knockdown, indicated by
significant decrease in Arg1, Mr, Fizz1, and Ym1 mRNA expression
(Figure 5C ). Similar effects were found after FAK and Akt1
intervention. After inhibiting phosphorylation of these two proteins,
the downstream signaling was significantly suppressed together with
reduced M2 polarization (Figures 5D-G ).