APN attenuates late fibrosis induced by acute ischemia reperfusion injury in mice via APPL1/AMPK signaling pathway

ZHOU Jun; LIN Wen-jing; LIN Sen; HUANG Zhen-xing; HUANG Teng; ZHONG Ji-ying; YANG Cheng-xiang

Abstract：Objective To investigate the attenuation by APN on late fibrosis induced by acute ischemia reperfu-sion injury in mice via APPL1 /AMPK signaling pathway.Methods Forty -eight male C57BL/6 mice were randomly di-vided into sham operation group (Group Sham), acute ischemia -reperfusion group (Group IRI), acute ischemia -reper-fusion plus APN group (Group APN/IRI) and acute ischemia -reperfusion plus NS group (Group NS/IRI).The gAPN (5 μg/g) and physiological saline were injected intraperitoneally 15 min before operation and every 24 h after operation in Group APN/IRI and Group NS/IRI, respectively.Renal acute ischemia reperfusion group were performed open renal per-fusion after bilateral renal pedicle clip for 30 min was performed in Group IRI, as separation of renal pedicle without clip was performed in Group Sham.On the 2nd day after the operation, 6 mice were randomly selected from each groups were sacrificed for blood and kidney samples.The renal histopathological changes were observed through Schiff periodic acid staining (PAS).The contents of BUN and Scr were determined.The APPL1 protein expression and the phosphorylate lev-el of AMPK were detected by Western blot.On the 14th day after the operation, 6 mice from each group were sacrificed for kidney samples.The αsmooth muscle actin (α-SMA) and transforming growth factor beta 1 (TGF -β1 ) mRNA were determined by real -time PCR.The degree of kidney fibrosis was observed through Sirus red staining.Results Com-pared with Group Sham, tubular interstitial damage were significantly aggravated and the levels of BUN and Scr were in-creased in Group IRI, APN/IRI group and NS/IRI group on the 2nd day after the operation (P <0.05), so were the in-creases APPL1 protein and the phosphorylate level of AMPK (P <0.05).Compared with Group IRI, tubular interstitial damage were significantly attenuated and the levels of BUN and Scr were significantly reduced in Group APN/IRI group on the 2nd day after the operation (P <0.05), so were the increases APPL1 protein and the phosphorylate level of AMPK (P <0.05).Compared with Group Sham, the degree of kidney fibrosis and the expression of α-SMA and TGF -β1 were significantly increased on the 14th day after the operation (P <0.05).Compared with Group IRI, the degree of kidney fi-brosis and the expression of α-SMA and TGF -β1 were significantly reduced on the 14th day after the operation (P <0.05).Conclusion APN attenuates late fibrosis induced by acute ischemia reperfusion injury in mice via APPL1/AMPK signaling pathway.