A Parathyroid Hormone/Salt-Inducible Kinase Signaling Axis Controls Renal Vitamin D Activation and Organismal Calcium Homeostasis

The underling mechanism used by PTH to promote 1,25-vitamin D synthesis remains unknown. Here, we demonstrate that Salt Inducible Kinases (SIK) inhibitors drive renal 1,25-vitamin D production, as PTH inhibits SIK cellular activity by cAMP-dependent PKA phosphorylation. Although there are some evidence that PTH increases Cyp27b1 in proximal tubule epithelial cells, this has not been explored/confirmed using next generation sequencing. Thus, we are interested in identifying cell populations that are responsible for PTH- or SIK-inhibition induced Cyp27b1 increase. 8 week old C57BL6 male mice were treated with a single IP injection of either the vehicle, PTH (1-34) or SK-124 (n=3 per treatment group). After euthanasia, kidneys were immediately prepared for single cell suspensions.