Different response patterns of several ligands at the sphingosine‐1‐phosphate receptor subtype 3 (S1P₃)

Abstract

Background and purpose: Recently, some ligands targeting the sphingosine-1-phosphate receptor subtype 3 (S1P3) have become available. The characterization of these compounds was mainly based on one functional read-out system, although S1P3 receptors are known to activate different signal transduction pathways. Therefore, this study pharmacologically characterizes these compounds using different assays. Experimental approach: Using CHO-FlpIn cells expressing the human S1P3 receptor the potencies and maximal effects of S1P, FTY720-P, VPC23019, VPC23153 and VPC24191 were determined in three different assays [inhibition of cAMP accumulation, elevation of intracellular calcium concentrations ([Ca 2+ ]i) and S1P3 receptor internalization].Key results: All compounds tested inhibited forskolin-induced cAMP accumulation, increased [Ca 2+ ]i and induced S1P3 receptor internalization but with different potencies and maximal effects. S1P was the most potent compound in all assays followed by FTY720-P. The VPC compounds were generally less potent than S1P and FTY720-P. Regarding the maximal effects, all compounds except VPC23153, behaved as full agonists in the cAMP accumulation assay. In the calcium assay, FTY720-P, VPC23019 and VPC24191 displayed partial and VPC23153 weak partial agonist activity, relative to S1P. Interestingly, treatment with the Gi inactivator Pertussis toxin, did not affect S1P-induced [Ca 2+ ]i elevations but inhibited those in response to the other compounds, by about 50%. Conclusions and implications:This study demonstrated differential response patterns at the S1P3 receptor for a range of ligands. These differences could indicate the presence of functional selectivity at this receptor as FTY720-P and the VPC compounds seemed to signal predominantly via Gi -whereas S1P activated Gi and Gq-coupled pathways.

Regulation of endothelial nitric oxide synthase activation in endothelial cells by S1P1 and S1P3

“…These results show that FTY720P-induced eNOS activation is regulated primarily via S1P 3 , whereas S1P 1 seems to have also a regulatory, but subordinate meaning. These results are in line with previously published data [39]. Therefore, the inhibitory effect of W146 and CAY10444 may not be suitable for studying the effects of FTY720P on S1P receptors in HUVEC, whereas VPC23019 could block an FTY720P-induced eNOS activation comparable to the knockout experiments.…”

“…For the unselective S1P 3 agonists S1P, FTY720 and VPC24191, different response patterns of S1P 3 activation are known. Whereas FTY720 and VPC24191 signal predominantly via G(i)-mediated pathways, S1P signals via G(i) and G(q)-coupled pathways [39]. Therefore, VPC24191 and FTY720P, both agonists of S1P 1 and S1P 3 [19,40], were tested.…”

S1P3 confers differential S1P‐induced migration by autoreactive and non‐autoreactive immature B cells and is required for normal B‐cell development

“…Thus, we hypothesized that S1P3 was responsible for non-autoreactive immature B cell chemotaxis to S1P and initially used pharmacological S1P receptor agonists and antagonists to test this hypothesis. Specifically, we used the CAY10444 selective S1P3 antagonist [37], VPC24191, an S1P1 and S1P3 agonist [38–40], SEW2871, a selective S1P1 agonist [41], and VPC23152, an S1P4 agonist [42]. Treatment of non-autoreactive immature B cells with CAY10444 led to a significant (p = 0.05) inhibition of S1P migration (Fig.…”

Inflammatory lipid sphingosine-1-phosphate upregulates C-reactive protein via C/EBPβ and potentiates breast cancer progression

“…24,32,33 We examined the involvement of S1P 3 -G aq coupling in S1P-induced CRP expression in MCF10A cells. As shown in Figure 3a, S1P-induced CRP expression was markedly inhibited by an siRNA targeting S1P 3 or by an S1P 3 receptor antagonist CAY10444.…”