The signaling mechanism of the sphingosylphosphorylcholine-induced contraction in cat esophageal smooth muscle cells

Abstract

We investigated the signaling pathway on sphingosinephosphorylcholine (SPC) -induced contraction in cat esophageal smooth muscle cells. SPC induced in a dose-dependent manner contractile effect. We have previously shown that lysophospholipid (LPL) receptor subtypes including the S1P1, S1P2, S1P3, and S1P5 receptor are present in esophageal smooth muscle. Only EDG-5 (S1P2) receptor antibody penetration into permeablilized cells inhibited the SPC-induced contraction. Pertussis toxin (PTX) and specific antibodies to G(i1), G(i2), G(i3) and G(o) inhibited the contraction, implying that SPC-induced contraction depends on PTX-sensitive G(i1), G(i2), G(i3), and G(o) protein. A phospholipase inhibitor U73122 and incubation of permeabilized cells with PLC-beta3 antibody inhibited SPC-induced contraction. The PKC-mediated contraction may be isozyme specific since only PKCepsilon antibody inhibited the contraction. Preincubation with MEK inhibitor PD98059 blocked the SPC-induced contraction, but p38 MAPK inhibitor SB202190 did not. Cotreatment with GF109203X and PD98059 did not show synergistic effects, suggesting that these two kinases are involved in the same signaling pathway in the SPC-induced contraction. The data suggest that S1P-induced contraction in feline esophageal smooth muscle cells depends on activation of the G(i1), G(i2), G(i3) and G(o) proteins and the PLCbeta3 isozyme via the S1P2 receptor, leading to stimulation of a PKCE pathway, which subsequently activates a p44/p42 MAPK pathway.

Sphingosylphosphorylcholine potentiates vasoreactivity and voltage-gated Ca2+ entry via NOX1 and reactive oxygen species

“…The differential effects of Gö6983 and Gö6976 imply a novel isoform of PKC, 29 which like conventional PKCs are activated by PLC-derived diacylglycerol; conventional PKCs have been previously shown to play no role in the action of SPC. 6 , 28 While we originally proposed PKCδ, we show here that SPC-induced potentiation of constriction was unaltered in MA from mice lacking PKCδ ( Figure 2 ). However, another novel isoform, PKCε, has been implicated in SPC-induced constriction of cat oesophagus smooth muscle.…”

“…The above precludes any role for PKCδ, suggesting involvement of PKCε, another novel isoform which has been implicated in the actions of SPC. 28 We were unable to source PKCε −/− mice, but utilized instead the specific PKCε translocation inhibitor peptide (Glu-Ala-Val-Ser-Leu-Lys-Pro-Thr). 29 This strongly suppressed SPC-induced potentiation of depolarization-induced contraction in both MA and IPA ( Figure 3 A and B ).…”

The effect of sphingosine-1-phosphate on colonic smooth muscle contractility: Modulation by TNBS-induced colitis

“…The Rho kinase pathway of calcium sensitization has also been implicated in S1P-induced contraction of guinea-pig trachea [38], urinary bladder [31, 37], human airway smooth muscle [26] and porcine retinal arterioles [51]. Kim et al have reported a role for the PKC pathway of calcium sensitization in S1P-induced contraction of feline esophageal smooth muscle cells [56]. Other studies have shown that both PKC and Rho-kinase pathways of calcium-sensitization are involved in S1P-induced contractions of the myometrium [25] and porcine renal arterioles [51].…”

Signaling Pathway of Lysophosphatidic Acid-Induced Contraction in Feline Esophageal Smooth Muscle Cells

“…In our previous study, we had used formalin or acrolein, instead of accustain [35]. The accustain was less cytotoxic than formalin and acrolein when preliminary test was done.…”