RT Journal Article
T1 Orai1 and TRPC1 Proteins Co-localize with CaV1.2 Channels to Form a Signal Complex in Vascular Smooth Muscle Cells.
A1 Ávila-Medina, Javier
A1 Calderón-Sánchez, Eva
A1 González-Rodríguez, Patricia
A1 Monje-Quiroga, Francisco
A1 Rosado, Juan Antonio
A1 Castellano, Antonio
A1 Ordóñez, Antonio
A1 Smani, Tarik
K1 CaV1.2
K1 CaV1.2 channel
K1 Orai1
K1 TRPC1
K1 Vascular tone regulation
K1 calcium
K1 calcium release-activated calcium channel protein 1 (ORAI1)
K1 excitation-contraction coupling (E-C coupling)
K1 ion channel
K1 vascular smooth muscle cells
AB Voltage-dependent CaV1.2 L-type Ca2+ channels (LTCC) are the main route for calcium entry in vascular smooth muscle cells (VSMC). Several studies have also determined the relevant role of store-operated Ca2+ channels (SOCC) in vascular tone regulation. Nevertheless, the role of Orai1- and TRPC1-dependent SOCC in vascular tone regulation and their possible interaction with CaV1.2 are still unknown. The current study sought to characterize the co-activation of SOCC and LTCC upon stimulation by agonists, and to determine the possible crosstalk between Orai1, TRPC1, and CaV1.2. Aorta rings and isolated VSMC obtained from wild type or smooth muscle-selective conditional CaV1.2 knock-out (CaV1.2KO) mice were used to study vascular contractility, intracellular Ca2+ mobilization, and distribution of ion channels. We found that serotonin (5-HT) or store depletion with thapsigargin (TG) enhanced intracellular free Ca2+ concentration ([Ca2+]i) and stimulated aorta contraction. These responses were sensitive to LTCC and SOCC inhibitors. Also, 5-HT- and TG-induced responses were significantly attenuated in CaV1.2KO mice. Furthermore, hyperpolarization induced with cromakalim or valinomycin significantly reduced both 5-HT and TG responses, whereas these responses were enhanced with LTCC agonist Bay-K-8644. Interestingly, in situ proximity ligation assay revealed that CaV1.2 interacts with Orai1 and TRPC1 in untreated VSMC. These interactions enhanced significantly after stimulation of cells with 5-HT and TG. Therefore, these data indicate for the first time a functional interaction between Orai1, TRPC1, and CaV1.2 channels in VSMC, confirming that upon agonist stimulation, vessel contraction involves Ca2+ entry due to co-activation of Orai1- and TRPC1-dependent SOCC and LTCC.
YR 2016
FD 2016-08-17
LK http://hdl.handle.net/10668/10367
UL http://hdl.handle.net/10668/10367
LA en
DS RISalud
RD Apr 17, 2025