Hydroxytyrosol inhibits apoptosis in ischemia/reperfusion-induced acute kidney injury via activating Sonic Hedgehog signaling pathway.

Abstract

Acute kidney injury (AKI) is a common critical illness in clinic, which seriously threatens the life of patients. The aim of this study was to validate the anti-apoptotic effect of hydroxytyrosol (HT) in ischemia/reperfusion (I/R)-induced AKI. The cell model of AKI was established by hypoxia/reoxygenation (H/R), and the animal model of AKI was established by I/R. The apoptosis was observed by Caspase-3 activity assay, flow cytometry and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) staining. Cell viability was detected by cell counting kit-8 (CCK-8) assay. Protein expression was measured by Western blot and mRNA level was analyzed by quantitative real-time polymerase chain reaction (RT-PCR). Renal function was assessed by measuring serum creatinine (Cr) and blood urea nitrogen (BUN). H/R induced apoptosis of HK-2 cells and reduced cell viability. When HK-2 cells were pretreated with HT, apoptosis was markedly inhibited, and cell viability was greatly increased. In addition, HT could inhibit I/R-induced apoptosis of rat kidney cells and could notably improve rat kidney function. H/R promoted Sonic Hedgehog (SHH) expression in HK-2 cells, while HT treatment further enhanced SHH expression. Similarly, I/R induces SHH expression in kidney tissue, and HT could further promote SHH expression. These results indicated that HT could inhibit apoptosis in I/R-induced AKI via activating SHH signaling pathway.