title: A functional interaction between TRPC/NCKX induced by DAG plays a role in determining calcium influx independently from PKC activation.
abstract: Ca(2+)influx might occur through K(+)-dependent Na(+)/Ca(2+) exchanger operating in reverse mode (rNCKX). In a cellular model different from platelets, an interaction between canonical transient receptor potential cation (TRPC) channels and NCX has been found. The aim of this study was to verify whether the TRPC/NCKX interaction operates in human platelets. Our results showed that the diacylglycerol (DAG) analogue, 1-oleoyl-2-acetyl-sn-glycerol (OAG) induced rNCKX-mediated Ca(2+) influx through TRPC-mediated Na(+) influx. DAG-induced activation of TRPC/NCKX occurs independently of protein kinase C (PKC) activation, as PKC inhibitor did not modify OAG-mediated Ca(2+) influx. Moreover, as both rNCKX and TRPC inhibitors reduced OAG-induced platelet aggregation which, conversely, was increased by flufenamic acid, known to develop TRPC activity, it could be suggested that the TRPC/NCKX interaction has a role in OAG-dependent platelet aggregation.
authors.affiliation: Department of Experimental Medicine, Sapienza University of Rome , Rome , Italy.
authors.forename: Fabio M
authors.initials: FM
authors.lastname: Pulcinelli
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Trifirò
authors.forename: Isabella
authors.initials: I
authors.lastname: Massimi
authors.forename: Livia
authors.initials: L
authors.lastname: Di Renzo
mesh_terms: D001792:Blood Platelets / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002118:Calcium / Q000097:blood*; D015220:Calcium Channels / Q000097:blood*; D004075:Diglycerides / Q000494:pharmacology*; D004789:Enzyme Activation; D006801:Humans; D010974:Platelet Aggregation / Q000187:drug effects / Q000502:physiology; D011493:Protein Kinase C / Q000097:blood*; D015398:Signal Transduction; D050052:TRPC Cation Channels / Q000097:blood*
chemical_list: C011439:1,2-diacylglycerol; D015220:Calcium Channels; D004075:Diglycerides; D050052:TRPC Cation Channels; D011493:Protein Kinase C; D002118:Calcium