Pirfenidone inhibits macrophage infiltration in 5/6 nephrectomized rats

Tubulointerstitial macrophage infiltration is a hallmark of chronic kidney disease involved in the progression of renal fibrosis. Pirfenidone is a newly identified antifibrotic drug, the potential mechanism of which remains unclear. The aim of this study was to investigate the effects of pirfenidone on M1/M2 macrophage infiltration in nephrectomized rats. Nephrectomized rats were treated with pirfenidone by gavage for 12 wk. Twenty-four hour urinary protein, N-acetyl-β-d-glycosaminidase (NAG) activity, systolic blood pressure, and C-reactive protein were determined. Paraffin-embedded sections were stained for CD68, CCR7, and CD163 macrophages. Monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1α (MIP-1α), as well as M1 and M2 macrophages secretory markers, were evaluated by real-time RT-PCR and Western blotting analysis. Pirfenidone significantly improved the elevated proteinuria and NAG activity from week 2 onward after surgery. Pirfenidone attenuated interstitial fibrosis an...