The role of DNA damage as a therapeutic target in autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenic kidney disease and is caused by heterozygous germ-line mutations in either PKD1 (85%) or PKD2 (15%). It is characterised by the formation of numerous fluid-filled renal cysts and leads to adult-onset kidney failure in ~50% of patients by 60 years. Kidney cysts in ADPKD are focal and sporadic, arising from the clonal proliferation of collecting-duct principal cells, but in only 1-2% of nephrons for reasons that are not clear. Previous studies have demonstrated that further postnatal reductions in PKD1 (or PKD2) dose are required for kidney cyst formation, but the exact triggering factors are not clear. A growing body of evidence suggests that DNA damage, and activation of the DNA damage response pathway, are altered in ciliopathies. The aims of this review are to: (i) analyse the evidence linking DNA damage and renal cyst formation in ADPKD; (ii) evaluate the advantages and disadvantages of biomarkers to assess DNA damage in ADPKD and finally, (iii) evaluate the potential effects of current clinical treatments on modifying DNA damage in ADPKD. These studies will address the significance of DNA damage and may lead to a new therapeutic approach in ADPKD.