title: Strain-induced vascular endothelial cell proliferation requires PI3K-dependent mTOR-4E-BP1 signal pathway.
abstract: The aim of this study was to determine whether the phosphatidylinositol 3-kinase (PI3K)-dependent mammalian target of rapamycin (mTOR)-eukaryotic initiation factor 4E binding protein 1 (4E-BP1) signal pathway and S6 kinase (S6K), the major element of the mTOR pathway, play a role in the enhanced vascular endothelial cell (EC) proliferation induced by cyclic strain. Bovine aortic ECs were subjected to an average of 10% strain at a rate of 60 cycles/min for < or =24 h. Cyclic strain-induced EC proliferation was reduced by pretreatment with rapamycin but not the MEK1 inhibitor PD-98059. The PI3K inhibitors wortmannin and LY-294002 also attenuated strain-induced EC proliferation and strain-induced activation of S6K. Rapamycin but not PD-98059 prevented strain-induced S6K activation, and PD-98059 but not rapamycin prevented strain-induced activation of extracellular signal-regulated kinases 1 and 2. Cyclic strain also activated 4E-BP1, which could be inhibited by PI3K inhibitors. These data suggest that the PI3K-dependent S6K-mTOR-4E-BP1 signal pathway may be critically involved in strain-induced bovine aortic EC proliferation.
authors.affiliation: Dept. of Surgery, Yale University School of Medicine, 333 Cedar St., New Haven, CT 06520, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Bauer E
authors.initials: BE
authors.lastname: Sumpio
mesh_terms: D064413:3-Phosphoinositide-Dependent Protein Kinases; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D001011:Aorta / Q000166:cytology; D002352:Carrier Proteins / Q000378:metabolism*; D002417:Cattle; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002867:Chromones / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000166:cytology* / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism; D009025:Morpholines / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D019893:Ribosomal Protein S6 Kinases / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D020123:Sirolimus / Q000494:pharmacology; D058570:TOR Serine-Threonine Kinases; D000077191:Wortmannin
chemical_list: D064413:3-Phosphoinositide-Dependent Protein Kinases; D000730:Androstadienes; D000903:Antibiotics, Antineoplastic; D002352:Carrier Proteins; D002867:Chromones; D004791:Enzyme Inhibitors; D005419:Flavonoids; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D009025:Morpholines; D019869:Phosphatidylinositol 3-Kinases; D010726:Phosphodiesterase Inhibitors; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010750:Phosphoproteins; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D019893:Ribosomal Protein S6 Kinases; D020123:Sirolimus; D058570:TOR Serine-Threonine Kinases; D000077191:Wortmannin; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one