title: TRPP2 modulates ryanodine- and inositol-1,4,5-trisphosphate receptors-dependent Ca2+ signals in opposite ways in cerebral arteries.
abstract: TRPP2 is a cationic channel expressed in plasma membrane and in sarcoplasmic reticulum. In several cell lines, TRPP2 is described as a reticulum Ca(2+) leak channel but it also interacts with ryanodine and inositol 1,4,5-trisphosphate (InsP3) receptors to inhibit and increase the release of Ca(2+) stores, respectively. TRPP2 is known to be expressed in vascular smooth muscle cells, however its function in Ca(2+) signals remains poorly described in native cells, principally because the pharmacology is not developed. TRPP2 was expressed in cerebral arteries. Triptolide evoked Ca(2+) responses in a Ca(2+)-free solution as well as permeabilized arteries. This Ca(2+) signal was inhibited in presence of antisense oligonucleotide and siRNA directed against TRPP2 and antibody directed against the first loop of TRPP2. The partial inhibition of TRPP2 expression increased both the caffeine-evoked Ca(2+) responses and in vivo contraction. It also decreased the InsP3-evoked Ca(2+) responses. Finally, aging affected the regulations in which TRPP2 is engaged, whereas the triptolide-evoked Ca(2+) response was not modified. Taken together, our results have shown that TRPP2 is implicated in triptolide-induced Ca(2+) release from intracellular Ca(2+) stores. TRPP2 functionally interacts with both ryanodine and InsP3 receptors. These interactions were not similar in adult and old mice.
authors.affiliation: Univ. Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France.
authors.forename: Azzedine
authors.initials: A
authors.lastname: Abdi
authors.affiliation: ImmuSmol PTIB, Hopital Xavier Arnozan, Avenue du Haut Leveque, F-33600 Pessac, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Mazzocco
authors.affiliation: Univ. Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France.
authors.forename: François-Pierre
authors.initials: FP
authors.lastname: Légeron
authors.affiliation: INSERM, UA01, Clinatec Laboratory, Biomedical Research Center Edmond J. Safra, F-38000 Grenoble, France; UJF, UA01, Clinatec Laboratory, Biomedical Research Center Edmond J. Safra, F-38000 Grenoble, France; CHU Grenoble, UA01, Clinatec Laboratory, Biomedical Research Center Edmond J. Safra, F-38000 Grenoble, France; CEA, LETI, Clinatec, Biomedical Research Center Edmond J. Safra, F-38000 Grenoble, France.
authors.forename: Blaise
authors.initials: B
authors.lastname: Yvert
authors.affiliation: Univ. Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Macrez
authors.affiliation: Univ. Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France. Electronic address: jean-luc.morel@u-bordeaux.fr.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Morel
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling; D002536:Cerebral Arteries / Q000378:metabolism*; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D050396:TRPP Cation Channels / Q000378:metabolism*
chemical_list: D002118:Calcium; D053496:Inositol 1,4,5-Trisphosphate Receptors; D050396:TRPP Cation Channels
keywords: Aging; Calcium signaling; Ryanodine receptor; TRPP2; Triptolide