Developing a more clinically-relevant mouse model of cisplatin-induced nephrotoxicity.

Cisplatin is a nephrotoxic chemotherapeutic that causes acute kidney injury (AKI) in 30% of patients. Although recovery can occur after one episode of cisplatin-induced AKI, studies have indicated multiple episodes may lead to the development of chronic kidney disease (CKD), an irreversible disease with no current treatments. The standard mouse model of cisplatin-induced AKI consists of one, high dose of cisplatin (\u3e 20 mg/kg) that is lethal to the animal three days later. This model doesn’t accurately reflect the repeated dosing regimen patients receive, and doesn’t allow for long-term outcome studies of pathologies associated with CKD. We have developed a repeated dosing model of cisplatin (7mg/kg once a week for four weeks). This model allows for the long-term survival of mice, and the associated pathology is fibrosis-the hallmark of CKD. Thus, data indicate that the repeated dosing model can be used to study AKI to CKD progression

Inhibiting glucosylceramide synthase exacerbates cisplatin-induced acute kidney injury

Acute kidney injury (AKI), resulting from chemotherapeutic agents such as cisplatin, remains an obstacle in the treatment of cancer. Cisplatin-induced AKI involves apoptotic and necrotic cell death, pathways regulated by sphingolipids such as ceramide and glucosylceramide. Results from this study indicate that C57BL/6J mice treated with cisplatin had increased ceramide and hexosylceramide levels in the renal cortex 72 h following cisplatin treatment. Pretreatment of mice with inhibitors of acid sphingomyelinase and de novo ceramide synthesis (amitriptyline and myriocin, respectively) prevented accumulation of ceramides and hexosylceramide in the renal cortex and protected from cisplatin-induced AKI. To determine the role of ceramide metabolism to hexosylceramides in kidney injury, we treated mice with a potent and highly specific inhibitor of glucosylceramide synthase, the enzyme responsible for catalyzing the glycosylation of ceramides to form glucosylceramides. Inhibition of glucosylceramide synthase attenuated the accumulation of the hexosylceramides and exacerbated ceramide accumulation in the renal cortex following treatment of mice with cisplatin. Increasing ceramides and decreasing glucosylceramides in the renal cortex sensitized mice to cisplatin-induced AKI according to markers of kidney function, kidney injury, inflammation, cell stress, and apoptosis. Under conditions of high ceramide generation, data suggest that metabolism of ceramides to glucosylceramides buffers kidney ceramides and helps attenuate kidney injury.-Dupre, T. V., M. A. Doll, P. P. Shah, C. N. Sharp, D. Siow, J. Megyesi, J. Shayman, A.Bielawska, J. Bielawski, L. J. Beverly, M. Hernandez-Corbacho, C. J. Clarke, A. J. Snider, R. G. Schnellmann, L. M. Obeid, Y. A. Hannun, and L. J. Siskind. Inhibiting glucosylceramide synthase exacerbates cisplatin-induced acute kidney injury.National Institute of Diabetes and Digestive and Kidney Diseases [R01-DK093462]; National Institutes of Health [P30 CA138313, P20RR017677, UH2NS092981, 1R01HD076004-04, GM097741, PO1CA097132]; Veterans Affairs Merit Awards [1I01BX002021-04, CAMM-011-13S]12 month embargo; Published online: May 10, 2017,This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]