Fig 3.

Autosomal dominant polycystic kidney disease (ADPKD) osteoblasts bone mineralize more rapidly in culture compared with healthy controls. (A) Cultured PKD mutant osteoblasts exhibit low alkaline phosphatase (ALP) activities (μmol/min/mL) after 14 days in culture. (B,C) Time‐course analyses of ADPKD osteoblast mineralization compared with healthy controls after 7, 14, and 21 days assessed by Alizarin Red S staining. Cells were grown under mineralizing conditions (10mM‐β‐glycerol phosphate and 100‐μg/mL ascorbic acid). Osteoblasts with nontruncating mutations in PKD1/2 showed lowest levels of mineralization, whereas truncating PKD1/2 mutations mineralized at levels similar to or higher than healthy controls. Quantification of mineralization rates were assessed by Alizarin Red S staining after 2 weeks. (D) Alizarin Red S stained mineralized nodules under light microcopy (×40) at 14 and 21 days from mutant PKD osteoblasts. (E) Osteoblasts from patients with non‐ADPKD chronic kidney disease (CKD) with low bone turnover mineralize slower than healthy osteoblasts after 21 days as assessed by Alizarin Red S staining intensity. Images displayed are representative of replicate experiments (n > 3). PKD1‐T = PKD1‐truncated; PKD1‐NT = PKD1‐nontruncated; PKD2‐T = PKD2‐truncated; PKD2‐NT = PKD2‐nontruncated. Error bars indicate mean ± SEM. **p > 0.01 and ***p > 0.001.