The preventive effects of colony-stimulating factor 1 receptor (CSF-1R) inhibition on bladder outlet obstruction induced remodeling

Introduction Bladder outlet obstruction (BOO) is a common problem that can affect bladder structure and function. Currently, there is no effective drugs available to prevent BOO-induced remodeling. Previous reports have demonstrated that the pathogenesis of BOO is associated with macrophage infiltration and polarization, which is physiologically dependent on colony-stimulating factor 1 receptor (CSF-1R) activation. Here we utilized a highly selective CSF-1R inhibitor, GW2580, to determine its preventive effects on BOO-induced remodeling. Methods A total of 24 Sprague-Dawley rats were randomly divided into sham, BOO + vehicle, and BOO + GW2580 group. GW2580 or vehicle control was administrated by oral gavage at daily doses of 40 mg/kg for 6 weeks. Bladder samples were collected for histopathology, immunohistochemistry, immunofluorescence, western blotting, and flow cytometry analysis. Results Our results demonstrated that bladder fibrosis was ameliorated by GW2580 compared with the vehicle group (22.01% +/- 5.13% vs. 32.15% +/- 7.24%, p < 0.01). Furthermore, treatment with GW2580 induced an inhibition of macrophage infiltration (4.41% +/- 1.28% vs. 13.57% +/- 3.42%, p < 0.001) and M2 macrophage polarization (10.67% +/- 4.15% vs. 28.59% +/- 6.38%, p < 0.001). There was also a decrease of profibrotic F4/80(+) alpha-smooth muscle actin(+) (alpha-SMA(+)) macrophage to myofibroblast transition (9.11% +/- 2.58% vs. 17.33% +/- 4.01%, p < 0.001) and CD163(+)TGF-beta 1(+) cells (7.68% +/- 2.10% vs. 14.17% +/- 4.09%, p < 0.01) in the GW2580 group when compared with the vehicle group. Conclusions In summary, our findings showed that GW2580 is a worthwhile candidate for a follow-up study to test in the treatment of BOO-induced remodeling.