Anti-Polyamine Therapy Restrains Kidney Cyst Growth in an Orthologous Mouse Model of Autosomal Dominant Polycystic Kidney Disease

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most common monogenic kidney disease worldwide. Tolvaptan is currently the only approved intervention to slow kidney cyst growth, but its indication is limited to rapidly progressing ADPKD and use compromises quality of life. Hence, new therapeutic options are of high clinical importance. Metabolic dysregulation is a hallmark of kidney cyst growth, including reprogramming of arginine metabolism and polyamine production. Sustained increases in polyamine synthesis drive pathological epithelial cell proliferation, tissue remodeling, and activation of M2-like macrophages, all known drivers of PKD. Difluoromethylornithine (DFMO) is an FDA approved irreversible inhibitor of ornithine decarboxylase (ODC1), the rate limiting enzyme in the arginine-polyamine pathway. Here, we treated C57Bl6/J p.R3277C (Pkd1RC/RC) mice for five months with DFMO-supplemented drinking water to test if DFMO treatment can slow kidney cyst growth in an orthologous model of ADPKD that mimics the disease pathophysiology seen in patients. At study end, Pkd1RC/RC mice treated with DFMO presented with significantly reduced percent kidney weight normalized to body weight as well as kidney cystic index and cyst number compared to control. Kidney RNA-seq analyses revealed correction of many genes and pathways perturbed in PKD post DFMO treatment, as well as overall heathier kidney cellular architecture as inferred by RNAseq-base cell type deconvolution. Our data highlight significant potential to repurpose DFMO for the treatment of patients with ADPKD and investigate the role of polyamines in modulating epithelial as well as myeloid cell fate in the setting of PKD.