TY - JOUR
T1 - Sphingosine-1-phosphate induces Gαi-coupled, PI3K/ras-dependent smooth muscle cell migration
AU - Tanski, William
AU - Roztocil, Elisa
AU - Davies, Mark G.
N1 - Funding Information:
This research was supported by grants for Mark Davies, M.D., Ph.D., from the American College of Surgeons Junior Faculty Award and from the Mentored Clinical Scientist Development Award, sponsored by the NIH-NHLBI/Lifeline Foundation (K08 HL 67746), and for William Tanski, M.D., from the NIH through a National Research Service Award (NRSA Grant 1 F32 HL69598-01).
PY - 2002
Y1 - 2002
N2 - Background. Sphingolipids such as sphingosine-1-phosphate (S-1-P) are potent extracellular mediators released in response to vessel injury. S-1-P binds to G-protein-coupled receptors, which can be either Gαi or Gαq linked. This study examines the signaling pathways involved in vascular smooth muscle cell migration after stimulation by S-1-P. We hypothesized that S-1-P stimulates migration of smooth muscle cells that is dependent upon a Gαi-coupled receptor, ras, phosphoinositol 3-kinase (PI3-K), and ERK 1/2. Methods. Vascular smooth muscle cells were cultured in vitro. A linear wound assay and Boyden chamber assay of migration were employed in the presence of S-1-P and inhibitors of Gαi [pertussis toxin (PTx), 100)ng/ml], Gαq (GP-2A, 10 μM), ras [manumycin A (MA), 10 μM], PI3-K [Wortmannin (Wn), 10 μM], and MEK1 [PD98059 (PD), 25 μM]. Western blotting was performed separately to examine p42/p44 MAP kinase (ERK 1/2) activation in response to S-1-P with these inhibitors. Results. S-1-P induced vascular smooth muscle cell migration. This response was decreased by preincubation with PTx, suggesting a receptor linked, Gαi-mediated response. Application of a Gαq inhibitor did not affect this response. S-1-P induced ERK 1/2 phosphorylation in a time-dependent manner. This S-1-P-induced cell migration was PD-sensitive in the Boyden chamber assay, confirming that it is MEK1- and ERK 1/2-dependent. Inhibition of ras with MA and PI3-K with Wn also reduced ERK phosphorylation and smooth muscle cell migration in response to S-1-P. Conclusion. S-1-P induces smooth muscle cell migration through a Gαi-linked, ras- and PI3-K-coupled, ERK) 1/2-dependent process. Understanding signal transduction will allow targeted molecular interventions to treat the response of a vessel to injury.
AB - Background. Sphingolipids such as sphingosine-1-phosphate (S-1-P) are potent extracellular mediators released in response to vessel injury. S-1-P binds to G-protein-coupled receptors, which can be either Gαi or Gαq linked. This study examines the signaling pathways involved in vascular smooth muscle cell migration after stimulation by S-1-P. We hypothesized that S-1-P stimulates migration of smooth muscle cells that is dependent upon a Gαi-coupled receptor, ras, phosphoinositol 3-kinase (PI3-K), and ERK 1/2. Methods. Vascular smooth muscle cells were cultured in vitro. A linear wound assay and Boyden chamber assay of migration were employed in the presence of S-1-P and inhibitors of Gαi [pertussis toxin (PTx), 100)ng/ml], Gαq (GP-2A, 10 μM), ras [manumycin A (MA), 10 μM], PI3-K [Wortmannin (Wn), 10 μM], and MEK1 [PD98059 (PD), 25 μM]. Western blotting was performed separately to examine p42/p44 MAP kinase (ERK 1/2) activation in response to S-1-P with these inhibitors. Results. S-1-P induced vascular smooth muscle cell migration. This response was decreased by preincubation with PTx, suggesting a receptor linked, Gαi-mediated response. Application of a Gαq inhibitor did not affect this response. S-1-P induced ERK 1/2 phosphorylation in a time-dependent manner. This S-1-P-induced cell migration was PD-sensitive in the Boyden chamber assay, confirming that it is MEK1- and ERK 1/2-dependent. Inhibition of ras with MA and PI3-K with Wn also reduced ERK phosphorylation and smooth muscle cell migration in response to S-1-P. Conclusion. S-1-P induces smooth muscle cell migration through a Gαi-linked, ras- and PI3-K-coupled, ERK) 1/2-dependent process. Understanding signal transduction will allow targeted molecular interventions to treat the response of a vessel to injury.
KW - Migration
KW - Signal transduction
KW - Sphingosine-1-phosphate
KW - Vascular smooth muscle cells
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U2 - 10.1006/jsre.2002.6529
DO - 10.1006/jsre.2002.6529
M3 - Article
C2 - 12443721
AN - SCOPUS:0036436753
SN - 0022-4804
VL - 108
SP - 98
EP - 106
JO - Journal of Surgical Research
JF - Journal of Surgical Research
IS - 1
ER -