Macrophage ITGAM is highly expressed with alternative M2 polarization in hyperuricemia-related CKD
Based on findings from integrated bioinformatic analysis, we firstly verified the expression and location of ITGAM in kidneys of hyperuricemia-related CKD mice. Compared to Day 0, ITGAM expression significantly increased on Day 7, 14, and 21 with a trend continuous growth at both of mRNA and protein levels (Figure 3A ). Considering ITGAM mainly but not only expressed in macrophage, we investigated the location of ITGAM in kidney tissue and found it highly co-located with macrophage marker F4/80 in tubulointerstitial and glomerular mesangial space (Figure 3B ). Furthermore, FAK signaling was significantly activated, indicated by the increased phosphorylation of FAK and Akt1, the decreased phosphorylation of GSK-3β, and the increased expression of β-catenin (Figure 3C ). Phosphorylated FAK and β-catenin mainly expressed in tubulointerstitial space (Figure 3D ), supporting the hypothesis that activation of FAK signaling might be related to macrophage ITGAM and they co-worked together mediating macrophage polarization in hyperuricemia-related CKD. Both of proteomic and proteomic data revealed activated macrophage M2 polarization in kidney tissue on Day 21, clarified by greatly the increased mRNA expression of Arg1 and Mr (Figure 3E ). We further performed qPCR to validate this finding and observed robust increase in Arg1 and Mr, followed by mild increase in Fizz1 (Figure 3F ).