Divergence in Endothelin-1- and Bradykinin-Activated Store-Operated Calcium Entry in Afferent Sensory Neurons

Abstract

Endothelin-1 (ET-1) and bradykinin (BK) are endogenous peptides that signal through Gαq/11-protein coupled receptors (GPCRs) to produce nociceptor sensitization and pain. Both peptides activate phospholipase C to stimulate Ca2+ accumulation, diacylglycerol production, and protein kinase C activation and are rapidly desensitized via a G-protein receptor kinase 2-dependent mechanism. However, ET-1 produces a greater response and longer lasting nocifensive behavior than BK in multiple models, indicating a potentially divergent signaling mechanism in primary afferent sensory neurons. Using cultured sensory neurons, we demonstrate significant differences in both Ca2+ influx and Ca2+ release from intracellular stores following ET-1 and BK treatments. As intracellular store depletion may contribute to the regulation of other signaling cascades downstream of GPCRs, we concentrated our investigation on store-operated Ca2+ channels. Using pharmacological approaches, we identified transient receptor potential canonical channel 3 (TRPC3) as a dominant contributor to Ca2+ influx subsequent to ET-1 treatment. On the other hand, BK treatment stimulated Orai1 activation, with only minor input from TRPC3. Taken together, data presented here suggest that ET-1 signaling targets TRPC3, generating a prolonged Ca2+ signal that perpetuates nocifensive responses. In contrast, Orai1 dominates as the downstream target of BK receptor activation and results in transient intracellular Ca2+ increases and abridged nocifensive responses.

Modulation of cardiac vagal tone by bradykinin acting on nucleus ambiguus

“…Likewise, previous studies indicate that BK increased [Ca 2+ ] i in rat submucosal plexus (Avemary and Diener, 2010), myenteric neurons (Wurner et al, 2014), sensory neurons of trigeminal ganglia (Szteyn et al, 2015), or liver cells (Garcia-Sainz and Avendano-Vazquez, 1999). In cardiac vagal neurons, the effect of BK was mediated by B2 receptors, similarly to the response in rat submucosal plexus (Avemary and Diener, 2010) or liver cells (Garcia-Sainz and Avendano-Vazquez, 1999), while in myenteric neurons both B1 and B2 receptors were involved in the response (Wurner et al, 2014).…”

“…In cardiac vagal neurons of nucleus ambiguus, similarly to sensory neurons (Szteyn et al, 2015) or subcutaneous fibroblasts (Pinheiro et al, 2013), both Ca 2+ influx and Ca 2+ release from internal stores contributed to the increase in [Ca 2+ ] i produced by BK. Using a pharmacological approach, we identified that in nucleus ambiguus neurons BK triggers Ca 2+ entry via P/Q-type voltage-gated Ca 2+ channels.…”

“…In other neuronal populations, BK elicited Ca 2+ influx via different mechanisms. For example, BK activated L-, N- and Q-types of Ca 2+ channels in neurons from rat submucosal plexus (Avemary and Diener, 2010) or produced store-operated calcium entry (SOCE) via Orai1 activation and TRPC3 channels in rat trigeminal neurons (Szteyn et al, 2015). …”

Multiple Inhibitory Mechanisms of Lidocaine on Bradykinin Receptor Activity in Model Sensory Neurons

“…A late shoulder in the calcium response was apparent in cells exposed to 100 nM BK, as a result of entry of extracellular calcium through receptor-modulated calcium-permeable channels 21 or of the release of calcium through store-operated channels, 22 or of entry through voltage-gated Ca +2 channels in response to a depolarization caused by BK. 23 When extracellular [Ca +2 ] was at its physiological level, this shoulder was relatively unaffected by LID (10 mM), compared with the peak response (Figs.…”

Bradykinin‐mediated Ca2+ signalling regulates cell growth and mobility in human cardiac c‐Kit+ progenitor cells

“…41 However, an earlier study demonstrated that bradykinin induces an increase in inositol 1,4,5-triphosphate (IP3) in neonatal rat cardiomyocytes 42 and bradykinin-mediated short nocifensive responses is related to activating PLC, followed by Orai1 in afferent sensory neurons. 18 In rat C6 glioma cells, bradykinin triggers Ca 2+ influx, resulting in calcium store Ca 2+ release, which is associated with nitric oxide generation for regulating permeability of blood-tumour barrier, 43 while in primary cultured rat brain microvascular endothelial cells, bradykinin-triggered Ca 2+ influx-induced Ca 2+ release is involved in regulation of the junction protein claudin-5. 19 A recent study shows that Ca 2+ signalling induced by bradykinin results from initial Ca 2+ release from ER IP3Rs followed by Ca 2+ entry through Ca 2+ release-activated channels in normal pancreatic stellate cells.…”