Isoliquiritigenin attenuates LPS-induced acute kidney injury through suppression of HMGB1 pathway in renal tubular against ferritinophagy

Septic acute kidney injury (AKI) mainly results in life-threatening renal dysfunction involving renal tubular injury to bring heavy burden to patients in intensive care unit (ICU). However, there is still a lack of therapy to prevent septic AKI effectively and inexpensive. To observe the role and novel mechanism of isoliquiritigenin (ISL) which isolated from the roots of licorice in septic AKI, we used LPS to induce renal tubular injury upon septic AKI both in vitro and in vivo. 50mg/kg ISL and 5 mg/kg Ferrostatin-1 were once given to the male C57BL/6 mice one hour before 1 mg/kg LPS i.p injection. 50 μM and 100 μM ISL respectively pre-treat the human renal tubular cells 5 hrs before 2 μg/ml LPS stimulation. We found ISL pretreatment apparently reversed LPS-induced renal dysfunction and ameliorated murine renal tubular injury by suppression HMGB1 pathway. Furthermore, we observed that LPS induced autophagy and ferroptosis in renal tubular, whereas ISL pretreatment significantly suppress autophagy and ferroptosis of renal tubular both in vitro and in vivo. Mechanically, autophagy activated ferroptosis via NCOA4-mediated ferritinophagy. Moreover, HMGB1 is required for ferritinophagy in renal tubular. ISL treatment inhibited the expression of HMGB1. Taken together, these results suggest that ISL protects LPS-induced acute kidney injury through suppression of HMGB1 pathway in renal tubular against ferritinophagy.