Metformin alleviated EMT and fibrosis after renal ischemia–reperfusion injury in rats

Abstract

Purpose The purpose of this study is to assess the potential effects of metformin on the development of EMT and tubulointerstitial fibrosis 12 weeks after acute renal ischemia–reperfusion. Methods Male Sprague–Dawley rats were randomly assigned to four groups: Sham, IRI, transient administration of metformin (TAM), and continuous administration of metformin (CAM). Metformin was administered i.p. at a dose of 125 μg kg − 1 d − 1 3 d prior to suffering from IRI (TAM), or from 3 d before suffering from IRI to 12 weeks after reperfusion (CAM). Renal function, histology, and expressions of IL-6, TNF-α, α-SMA, TGF-β1, Vimentin, and E-cadherin were analyzed. Results Tubulointerstitial fibrosis worsened further in IRI, accompanied by the increased expressions of interleukin-6, TNF-α, α-SMA, TGF-β1, Vimentin, and loss of E-cadherin. Although there were no significant differences between IRI and TAM (p > 0.05). Compared with the IRI, expressions of IL-6, TNF-α, α-SMA, TGF-β1, and Vimentin were reduced and the expression of E-cadherin was restored in CAM (p < 0.05). CAM also significantly promoted activation of AMPK (p < 0.05), which showed no difference among Sham, IRI, and TAM (p > 0.05). Conclusions CAM significantly attenuated tubulointerstitial fibrosis and EMT in rats, potentially via activation of AMPK and down-regulation of TGF-β1.