7-hydroxycoumarin protects against acute kidney injury by inhibiting necroptosis and promoting Sox-9-mediated cell proliferation

Abstract

Introduction: Acute kidney injury (AKI) is a sudden damage to kidney resulting in the abrupt decline of kidney function. In the study, we evaluated the renoprotective effect of 7-hydroxycoumarin, a natural derivative of coumarin from plants, in the cisplatin-induced AKI model. Methods: AKI was induced in male C57BL/6 mice (aged 6-8 weeks) by injection of cisplatin with a single dose at 20mg/kg intraperitoneally. Mice received the 7-hydroxycoumarin intraperitoneally at 12.5, 25 and 50 mg/kg for 3 consecutive days. The mice were sacrificed under anesthesia. Kidney tissues and serum were collected for further analysis. The signaling mechanisms were examined in tubular epithelial cells under the normal/cisplatin condition. Results: In vivo results showed that 7-hydroxycoumarin substantially protected against the decline of kidney function (decreased levels of serum creatinine and blood urea nitrogen) in AKI mice. The finding was consistent with the attenuation of tubular damage as shown by PAS staining and KIM-1 analyses. Moreover, 7-hydroxycoumarin also inhibited inflammation as demonstrated by the decreased inflammatory cytokines (TNF-a, IL-6 and MCP-1) and NF-kB P65 phosphorylation in the kidneys of AKI, which was associated with the cMyc/cyclin-D1 mediated cell proliferation. We further revealed that 7- hydroxycoumarin reduced inflammation by inhibiting RIPK1/RIPK3/MLKL-mediated necroptosis. Importantly, 7-hydroxycoumarin induced the cell proliferation of tubular epithelial cells with or without cisplatin stimulation, the knockout of Sox9 reversed the protective effects of 7-hydroxycoumarin on the cisplatin-treated HK-2 cells, indicating 7-hydroxycoumarin may work in a Sox9-dependent mechanism. Conclusions: 7-hydroxycoumarin inhibits cisplatin-induced acute kidney injury by suppressing RIPK1/RIPK3/MLKL-mediated necroptosis and promoting Sox-9-mediated proliferation. 7-hydroxycoumarin may serve as a potential therapeutic agent for AKI.