P0519HEXARELIN PROTECTS ISCHEMIA REPERFUSION INDUCED ACUTE KIDNEY INJURY BY TARGETING 14-3-3Σ

Abstract

Abstract Background and Aims Acute kidney injury (AKI), manifested as a sudden decline in renal function on the order of days or a week, is one of the most common complications and is strongly associated with renal prognosis, medical expenses and length of stay of hospitalized patients. However, incidence of AKI can be reduced by early intervention. Hexarelin is a synthetic analogue of ghrelin with a potent GH releasing activity, which is also found to exhibited a significant protectant activity against postischemic ventricular dysfunction in isolated perfused hearts subjected to low flow ischemia and reperfusion. This study aims to explore the effects of hexarelin on ischemia reperfusion induced acute kidney injury (I/R-AKI) and the underlying mechanism of it. Method Thirty healthy male SPF SD aged at 8 weeks weighing 250-300g rats were divided into 5 groups including normal group, sham operation group, acute kidney injury (AKI) group, acute kidney injury group after hexarelin (HEX + AKI), and acute kidney injury group after saline (Saline + AKI). Bilateral kidney artery clamping was applied for 50 min to induce AKI. The drug-administered group and the saline-controlled group rats were treated with intraperitoneal injections 7 days before modelling and the Hex + AKI group and the saline + AKI group were given Hexarelin (dose 100 μg/kg. d) and equal volume of saline, respectively. To explore the underlying mechanism of HEX on I/R-AKI, gene expression profiling of AKI samples were searched from Pubmed, GEO dataset. Differential expression genes were used to predict canonical signal transduction pathways and signalling networks. Molecular docking was used to predict the combination of hub proteins and HEX. Results 1) Renal function in HEX-pretreated rats was significantly improved compared with control group: HE results showed that renal tubules were less dilated and rebuilt after pretreatment, and the infiltration area was significantly reduced; serum creatinine (P = 0.0005 <0.05), urea nitrogen (P <0.0001) concentration were significantly reduced; RT-qPCR showed that relative expression of Kim-1 (P<0.0001), caspase3 (P = 0.007), Bax (P <0.0001), Bad (P = 0.0168 <0.05) in HEX+AKI group were significantly decreased while the relative expression of Bcl-2 (P <0.05) was significantly increased compared with saline treated rats; 2) Microarray data analysis showed that 63 differential expression genes including SFN, Cyr61, Kim-1 were hub genes in the development of I/R-AKI; 3) Three-dimensional structure of the hub proteins HEX were obtained from the SWISS-MODEL database and the PubChem compound database, and Autodock software was used to calculate the molecular docking between proteins and HEX. Results showed that HEX and the protein that encoded by the gene SFN (SFN, 14-3-3σ) binding stably with a binding energy of -8.51; Conclusion Hexarelin protects ischemia reperfusion induced acute kidney injury by targeting 14-3-3σ.