PT - JOURNAL ARTICLE AU - Ludmilla Bär AU - Philipp Hase AU - Michael Föller TI - PKC regulates the production of fibroblast growth factor 23 (FGF23) AID - 10.1101/520254 DP - 2019 Jan 01 TA - bioRxiv PG - 520254 4099 - http://biorxiv.org/content/early/2019/01/14/520254.short 4100 - http://biorxiv.org/content/early/2019/01/14/520254.full AB - Serine/threonine protein kinase C (PKC) is activated by diacylglycerol that is released from membrane lipids by phospholipase C in response to activation of G protein-coupled receptors or receptor tyrosine kinases. PKC isoforms are particularly relevant for proliferation and differentiation of cells including osteoblasts. Osteoblasts/osteocytes produce fibroblast growth factor 23 (FGF23), a hormone regulating renal phosphate and vitamin D handling. PKC activates NFκB, a transcription factor complex controlling FGF23 expression. Here, we analyzed the impact of PKC on FGF23 synthesis. Fgf23 expression was analyzed by qRT-PCR in UMR106 osteoblastlike cells and in IDG-SW3 osteocytes. Phorbol ester 12-O-tetradecanoylphorbol-13-acetate (PMA), a PKC activator, up-regulated Fgf23 expression. In contrast, PKC inhibitors calphostin C, Gö6976, sotrastaurin and ruboxistaurin supressed Fgf23 gene expression. NFκB inhibitor withaferin A abolished the stimulatory effect of PMA on Fgf23. PKC is a powerful regulator of FGF23 synthesis, an effect which is at least partly mediated by NFκB.