TY - JOUR
T1 - Heteromeric TRPV4/TRPC1 channels mediate calcium-sensing receptor-induced nitric oxide production and vasorelaxation in rabbit mesenteric arteries
AU - Greenberg, Harry Z. E.
AU - Carlton-Carew, Simonette R. E.
AU - Khan, Dhanak M.
AU - Zargaran, Alexander K.
AU - Jahan, Kazi S.
AU - Ho, W.-S. Vanessa
AU - Albert, Anthony P.
N1 - Funding Information: This work was supported by a British Heart Foundation PhD Studentship for H. Z. E. Greenberg (FS/13/10/30021 to A.P.A); and by the Biotechnology and Biological Sciences Research Council ( BB/J007226/1 to A.P.A).
PY - 2017/9
Y1 - 2017/9
N2 - Stimulation of calcium-sensing receptors (CaSR) by increasing the external calcium concentration (Ca2 +]o) induces endothelium-dependent vasorelaxation through nitric oxide (NO) production and activation of intermediate Ca2 +-activated K+ currents (IKCa) channels in rabbit mesenteric arteries. The present study investigates the potential role of heteromeric TRPV4-TRPC1 channels in mediating these CaSR-induced vascular responses. Immunocytochemical and proximity ligation assays showed that TRPV4 and TRPC1 proteins were expressed and co-localised at the plasma membrane of freshly isolated endothelial cells (ECs). In wire myography studies, increasing [Ca2 +]o between 1 and 6 mM induced concentration-dependent relaxations of methoxamine (MO)-induced pre-contracted tone, which were inhibited by the TRPV4 antagonists RN1734 and HC067047, and the externally-acting TRPC1 blocking antibody T1E3. In addition, CaSR-evoked NO production in ECs measured using the fluorescent NO indicator DAF-FM was reduced by RN1734 and T1E3. In contrast, [Ca2 +]o-evoked perforated-patch IKCa currents in ECs were unaffected by RN1734 and T1E3. The TRPV4 agonist GSK1016790A (GSK) induced endothelium-dependent relaxation of MO-evoked pre-contracted tone and increased NO production, which were inhibited by the NO synthase inhibitor L-NAME, RN1734 and T1E3. GSK activated 6pS cation channel activity in cell-attached patches from ECs which was blocked by RN1734 and T1E3. These findings indicate that heteromeric TRPV4-TRPC1 channels mediate CaSR-induced vasorelaxation through NO production but not IKCa channel activation in rabbit mesenteric arteries. This further implicates CaSR-induced pathways and heteromeric TRPV4-TRPC1 channels in regulating vascular tone.
AB - Stimulation of calcium-sensing receptors (CaSR) by increasing the external calcium concentration (Ca2 +]o) induces endothelium-dependent vasorelaxation through nitric oxide (NO) production and activation of intermediate Ca2 +-activated K+ currents (IKCa) channels in rabbit mesenteric arteries. The present study investigates the potential role of heteromeric TRPV4-TRPC1 channels in mediating these CaSR-induced vascular responses. Immunocytochemical and proximity ligation assays showed that TRPV4 and TRPC1 proteins were expressed and co-localised at the plasma membrane of freshly isolated endothelial cells (ECs). In wire myography studies, increasing [Ca2 +]o between 1 and 6 mM induced concentration-dependent relaxations of methoxamine (MO)-induced pre-contracted tone, which were inhibited by the TRPV4 antagonists RN1734 and HC067047, and the externally-acting TRPC1 blocking antibody T1E3. In addition, CaSR-evoked NO production in ECs measured using the fluorescent NO indicator DAF-FM was reduced by RN1734 and T1E3. In contrast, [Ca2 +]o-evoked perforated-patch IKCa currents in ECs were unaffected by RN1734 and T1E3. The TRPV4 agonist GSK1016790A (GSK) induced endothelium-dependent relaxation of MO-evoked pre-contracted tone and increased NO production, which were inhibited by the NO synthase inhibitor L-NAME, RN1734 and T1E3. GSK activated 6pS cation channel activity in cell-attached patches from ECs which was blocked by RN1734 and T1E3. These findings indicate that heteromeric TRPV4-TRPC1 channels mediate CaSR-induced vasorelaxation through NO production but not IKCa channel activation in rabbit mesenteric arteries. This further implicates CaSR-induced pathways and heteromeric TRPV4-TRPC1 channels in regulating vascular tone.
UR - http://www.scopus.com/inward/record.url?scp=85029357751&partnerID=8YFLogxK
U2 - 10.1016/j.vph.2017.08.005
DO - 10.1016/j.vph.2017.08.005
M3 - Article
C2 - 28867591
AN - SCOPUS:85029357751
SN - 1537-1891
VL - 96-98
SP - 53
EP - 62
JO - Vascular Pharmacology
JF - Vascular Pharmacology
ER -