5(S)-hydroxyeicosatetraenoic acid stimulates DNA synthesis in human microvascular endothelial cells via activation of Jak/STAT and phosphatidylinositol 3-kinase/Akt signaling, leading to induction of expression of basic fibroblast growth factor 2.
To understand the role of eicosanoids in angiogenesis, we have studied the effect of lipoxygenase metabolites of arachidonic acid on human microvascular endothelial cell (HMVEC) DNA synthesis. Among the various lipoxygenase metabolites of arachidonic acid tested, 5(S)-hydroxyeicosatetraenoic acid (5(S)-HETE) induced DNA synthesis in HMVEC. 5(S)-HETE also stimulated Jak-2, STAT-1, and STAT-3 tyrosine phosphorylation and STAT-3-DNA binding activity. Tyrphostin AG490, a specific inhibitor of Jak-2, significantly reduced tyrosine phosphorylation and DNA binding activity of STAT-3 and DNA synthesis induced by 5(S)-HETE. In addition, 5(S)-HETE stimulated phosphatidylinositol 3-kinase (PI3-kinase) activity and phosphorylation of its downstream targets Akt, p70S6K, and 4E-BP1 and their effector molecules ribosomal protein S6 and eIF4E. LY294002 and rapamycin, potent inhibitors of PI3-kinase and mTOR, respectively, also blocked the DNA synthesis induced by 5(S)-HETE. Interestingly, AG490 attenuated 5(S)-HETE-induced PI3-kinase activity and phosphorylation of Akt, p70S6K, ribosomal protein S6, 4E-BP1, and eIF4E. 5(S)-HETE induced the expression of basic fibroblast growth factor 2 (bFGF-2) in a Jak-2- and PI3-kinase-dependent manner. In addition, a neutralizing anti-bFGF-2 antibody completely blocked 5(S)-HETE-induced DNA synthesis in HMVEC. Together these results suggest that 5(S)-HETE stimulates HMVEC growth via Jak-2- and PI3-kinase-dependent induction of expression of bFGF-2. These findings also reveal a cross-talk between Jak-2 and PI3-kinase in response to 5(S)-HETE in HMVEC.
Zeng
Zhao-Zhu
ZZ
Department of Physiology and Center for Vascular Biology, University of Tennessee Health Science Center, 894 Union Avenue, Memphis, TN 38163, USA.
Yellaturu
Chandrahasa R
CR
Neeli
Indira
I
Rao
Gadiparthi N
GN
D002478:Cells, Cultured; D002867:Chromones / Q000494:pharmacology; D004261:DNA Replication / Q000187:drug effects*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000235:genetics*; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000494:pharmacology*; D053614:Janus Kinase 2; D009025:Morpholines / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt; D050794:STAT1 Transcription Factor; D050796:STAT3 Transcription Factor; D015398:Signal Transduction; D015534:Trans-Activators / Q000378:metabolism*
D002867:Chromones; D004268:DNA-Binding Proteins; D016222:Fibroblast Growth Factor 2; D006893:Hydroxyeicosatetraenoic Acids; D053614:Janus Kinase 2; D009025:Morpholines; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D011505:Protein-Tyrosine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D050794:STAT1 Transcription Factor; D050796:STAT3 Transcription Factor; D015534:Trans-Activators; C494079:STAT1 protein, human; C494086:STAT3 protein, human; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C022022:5-hydroxy-6,8,11,14-eicosatetraenoic acid; C507924:JAK2 protein, human; C494918:AKT1 protein, human