Cilia to basement membrane signalling is a biomechanical driver of autosomal dominant polycystic kidney disease
Autosomal dominant polycystic kidney disease (ADPKD), which affects around 4 million patients worldwide, is characterized by the formation of multiple tubule derived cysts, which grossly enlarge both kidneys and progressively compromise renal function. ADPKD mainly results from mutations in PKD1, leading to the loss of polycystin-1 protein, which localizes to primary cilia. Primary cilia are required for cyst formation but the biomechanical changes underlying cystogenesis upon loss of polycytin-1 are unknown. We find that cilia and polycystin-1 shape the tubular basement membrane (TBM). Combining orthologous mouse models with a tubule-on-chip approach allowing manipulations of TBM stiffness, we find that cilia regulate the composition and biomechanical properties of the TBM. In the setting of polycytin-1 loss, reduced TBM stiffness and increased luminal pressure act as biomechanical drivers of cyst formation. These findings suggest a novel biomechanical model for ADPKD and unveil that cilia to TBM signalling controls kidney shape.