Proteomics and metabolomics studies exploring the pathophysiology of renal dysfunction in autosomal dominant polycystic kidney disease and other ciliopathies

The primarycilium(PC)wasconsideredasa vestigial organelle withnosignificantphysiologicalimportance,untilthediscovery that PC perturbation disturbs several signalling pathways and results in the dysfunction of a variety of organs. Genetic studies have demonstrated that mutations affecting PC proteins or its anchoring structure, the basal body, underlie a class of human disorders (known as ciliopathies) characterized by a constella- tion of clinical signs. Further investigations have demonstrated that the PC is involved in a broad range of biological processes, inbothdevelopingandmaturetissues.Kidneydiseaseisacom- monclinicalfeatureofciliadisorders,supportingthehypothesis of a crucial role of the PC in kidneyhomoeostasis. Clinical pro- teomics and metabolomics are an expanding research area. Interestingly, the application of these methodologies to the analysis of urine, a biological sample that can be collected in a non-invasive fashion and possibly in large amounts, makes these studies feasible also in patients. The present article describes the most recent proteomic and metabolomic studies exploring kidney dysfunction in the setting of ciliopathies, showing the potential of these methodologies in the elucidation ofdiseasepathophysiologyandinthediscoveryofbiomarkers.