Effects of a CCR2 antagonist on macrophages and Toll-like receptor 9 expression in a mouse model of diabetic nephropathy

We classified kidney macrophages (Mφs) into bone marrow-derived (BM-) macrophages expressing high CD11b and tissue-specific resident (Res-) macrophages expressing low CD11b. In diabetic nephropathy (DN) model mice, TLR9 expression and TNF-α production via TLR9 activation in BM-Mφs and ROS production in Res-Mφs were enhanced. Furthermore, CCR2 antagonist suppressed the kidney infiltration of BM-Mφs and their function and the ROS production by Res-Mφs, with concomitant TLR9 suppression. Our study presents a new therapeutic strategy for DN.