Heteromeric TRPV4/TRPC1 channels mediate calcium-sensing receptor-induced nitric oxide production and vasorelaxation in rabbit mesenteric arteries

Abstract

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.

Feedback Control of Second Messengers Signaling Systems in White Adipose Tissue Adipocytes in Healthy State and Its Loss at Adiposity

“…[15][16][17][18][19][20]. Besides that, controversial results on the role of Ca 2+ and calcium-sensing receptors in the regulation of body fat depots [21][22][23] point on the important role of Ca 2+ in the mechanisms of self-control of second messengers signaling systems.…”

Endothelial Transient Receptor Potential Channels and Vascular Remodeling: Extracellular Ca2 + Entry for Angiogenesis, Arteriogenesis and Vasculogenesis

“…As reported in other cell types, naïve TRP channels may consist of heteromeric subunits also in vascular endothelial cells. The following endothelial TRP channel complexes were reported: TRPC1-TRPC4 (Cioffi et al, 2012;Sundivakkam et al, 2012;Greenberg et al, 2017), TRPC1-TRPV4 (Ma et al, 2011a,b), TRPC3-TRPC4 (Poteser et al, 2006), TRPV1-TRPV4 (O'Leary et al, 2019), TRPP2-TRPC1 (Berrout et al, 2012), and TRPC1-TRPP2-TRPV4 (Du et al, 2014). As anticipated earlier, heteromerization expands the range of gating properties and biophysical properties of endothelial TRP channels, thereby boosting their impact on the regulation of endothelial cell functions.…”

It takes more than two to tango: mechanosignaling of the endothelial surface

“…Activation of TRPV4 (agonist) induced NO production, and subsequent vasodilation could be prevented by L-NAME (N(ω)-nitro-L-arginine methyl ester, eNOS inhibitor), TRPV4 antagonist (RN1734), or TRPC1 antagonism (T1E3, blocking peptide). Heteromeric TRPV4 and TRPC1 channels mediate calcium-sensing receptor induced vasorelaxation through NO production [65].…”

“…TRPC1 is also co-localized with TRPV4 in EC from mesenteric arteries. This heteromeric channel is activated by CaSR and induces an increase in NO production and vasorelaxation [65,66].…”