Statins inhibit protein kinase D (PKD) activation in intestinal cells and prevent PKD1-induced growth of murine enteroids

We examined the impact of statins on protein kinase D (PKD) activation by G protein-coupled receptor (GPCR) agonists. Treatment of intestinal IEC-18 cells with cerivastatin inhibited PKD auto-phosphorylation at Ser916 induced by angiotensin II (ANG II) or vasopressin in a dose-dependent manner with half-maximal inhibition at 0.2 mM. Cerivastatin treatment inhibited PKD activation stimulated by these agonists for different times (5-60min) and blunted HDAC5 phosphorylation, a substrate of PKD. Other lipophilic statins, including simvastatin, atorvastatin and fluvastatin also prevented PKD activation in a dose-dependent manner. Using IEC-18 cell lines expressing PKD1 tagged with EGFP (Enhanced green fluorescent protein), cerivastatin or simvastatin blocked GPCR-mediated PKD1-EGFP translocation to the plasma membrane and its subsequent nuclear accumulation. Similar results were obtained in IEC-18 cells expressing PKD3-EGFP. Mechanistically, statins inhibited agonist-dependent PKD activation rather than acting directly on PKD catalytic activity since exposure to cerivastatin or simvastatin did not impair PKD auto-phosphorylationor PKD1-EGFP membrane translocation in response to phorbol dibutyrate, which bypasses GPCRs and directly stimulates PKC and PKD. Furthermore, cerivastatin did not inhibit recombinant PKD activity determined via an in vitro kinase assay. Using enteroids generated from intestinal crypt-derived epithelial cells from PKD1 transgenic mice as a model of intestina...
Source: Am J Physiol Cell Ph... - Category: Cytology Authors: Source Type: research