Enhancement by sphingosine 1-phosphate in vasopressin-induced phosphoinositide hydrolysis in aortic smooth-muscle cells: involvement of p38 MAP kinase.
We previously reported that sphingosine 1-phosphate (S-1-P), a sphingomyelin metabolite, activates p44/p42 mitogen-activated protein (MAP) kinase and p38 MAP kinase in aortic smooth-muscle A10 cells. In the present study, we investigated the effect of sphingomyelin metabolites on phospholipase C-catalyzing phosphoinositide hydrolysis induced by arginine vasopressin (AVP) in A10 cells. C(2)-ceramide and sphingosine had little effect on inositol phosphate (IP) formation stimulated by AVP. S-1-P, which alone slightly stimulated the IPs formation, dose-dependently amplified the AVP-induced formation of IPs. Tumor necrosis factor-alpha enhanced the AVP-induced formation of IPs. However, S-1-P did not enhance the formation of IPs by NaF, a heterotrimeric GTP-binding protein activator. Pertussis toxin inhibited the effect of S-1-P. PD98059, an inhibitor of the upstream kinase that activates p44/p42 MAP kinase, had little effect on the enhancement by S-1-P. SB203580, an inhibitor of p38 MAP kinase, suppressed the effect of S-1-P on the formation of IPs by AVP. SB203580 inhibited the AVP-induced phosphorylation of p38 MAP kinase. Pertussis toxin suppressed the phosphorylation of p38 MAP kinase by S-1-P. These results indicate that S-1-P amplifies AVP-induced phosphoinositide hydrolysis by phospholipase C through p38 MAP kinase in vascular smooth-muscle cells.
Kozawa
O
O
Department of Pharmacology, Gifu University School of Medicine, Gifu 500-8705, Japan.
Yamamoto
T
T
Tanabe
K
K
Akamatsu
S
S
Dohi
S
S
Uematsu
T
T
D001011:Aorta / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D001127:Arginine Vasopressin / Q000494:pharmacology*; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D006868:Hydrolysis; D007093:Imidazoles / Q000494:pharmacology; D008246:Lysophospholipids; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D037342:Pertussis Toxin; D010716:Phosphatidylinositols / Q000378:metabolism*; D010766:Phosphorylation; D011725:Pyridines / Q000494:pharmacology; D012969:Sodium Fluoride / Q000494:pharmacology; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D010566:Virulence Factors, Bordetella / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases
D004791:Enzyme Inhibitors; D005419:Flavonoids; D007093:Imidazoles; D008246:Lysophospholipids; D010716:Phosphatidylinositols; D011725:Pyridines; D014409:Tumor Necrosis Factor-alpha; D010566:Virulence Factors, Bordetella; D001127:Arginine Vasopressin; C060506:sphingosine 1-phosphate; D012969:Sodium Fluoride; D037342:Pertussis Toxin; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D013110:Sphingosine; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one