Genetic Knockout of Fatty Acid Amide Hydrolase Ameliorates Cisplatin-Induced Nephropathy in Mice

Abstract

Cisplatin is a potent first-line therapy for many solid malignancies such as breast, ovarian, lung, testicular and head and neck cancer. However, acute kidney injury (AKI) is a major dose-limiting toxicity in cisplatin therapy, which often hampers the continuation of cisplatin treatment. The endocannabinoid system, consisting of anandamide (AEA) and 2-arachidonoylglycerol and cannabinoid receptors, participates in different kidney diseases. Inhibition of fatty acid amide hydrolase (FAAH), the primary enzyme for the degradation of AEA and AEA-related N-acylethanolamines, elicits antiinflammatory effects; however, little is known about its role in cisplatin nephrotoxicity.The current study tested the hypothesis that genetic deletion of Faah mitigates cisplatininduced AKI. Male wild-type C57BL6 (WT) and Faah −/− mice were administered a single dose of intraperitoneal injection of cisplatin (30 mg/kg) and euthanatized 72 hours later.Faah −/− mice showed a reduction of cisplatin-induced blood urea nitrogen, plasma creatinine levels, kidney injury markers and tubular damage in comparison with WT mice. The renal protection from Faah deletion was associated with enhanced tone of AEA-related N-acylethanolamines (PEA and OEA), attenuated NF-κB/p65 activity, DNA damage markers p53, p21 and decreased expression of the inflammatory cytokine IL-1β as well as infiltration of macrophages and leukocytes in the kidneys. Notably, a selective FAAH inhibitor (PF-04457845) did not interfere with or perturb the antitumor effects of cisplatin in two head and neck squamous cell carcinoma cell lines, HN30 and HN12. Our work highlights that FAAH inactivation prevents cisplatin-induced nephrotoxicity in mice and that targeting FAAH could provide a novel strategy to mitigate cisplatin-induced nephrotoxicity.