Cyst growth in ADPKD is prevented by pharmacological and genetic inhibition of TMEM16A in vivo

In autosomal dominant polycystic kidney disease (ADPKD) multiple bilateral renal cysts gradually enlarge, leading to a decline in renal function. Transepithelial chloride secretion through cystic fibrosis transmembrane conductance regulator (CFTR) and TMEM16A ( anoctamin 1 ) are known to drive cyst enlargement. Here we demonstrate that loss of Pkd1 increased expression of TMEM16A and CFTR and Cl − secretion in murine kidneys, with TMEM16A essentially contributing to cyst growth. Upregulated TMEM16A enhanced intracellular Ca 2+ signaling and proliferation of Pkd1 -deficient renal epithelial cells. In contrast, increase in Ca 2+ signaling, cell proliferation and CFTR expression was not observed in Pkd1/Tmem16a double knockout mice. Knockout of Tmem16a or inhibition of TMEM16A in vivo by the FDA-approved drugs niclosamide and benzbromarone, as well as the TMEM16A-specific inhibitor Ani9 largely reduced cyst enlargement and abnormal cyst cell proliferation. The present data establish a therapeutic concept for the treatment of ADPKD. Polycystic kidney disease (PKD) is characterized by the formation of large renal cysts, which lead to a decline in renal function. Here the authors show that genetic and chemical inhibition of TMEM16A largely reduces cyst enlargement in an in vivo model of autosomal dominant PKD.