title: Arachidonic acid release by H2O2 mediated proliferation of mouse embryonic stem cells: involvement of Ca2+/PKC and MAPKs-induced EGFR transactivation.
abstract: Reactive oxygen species (ROS) generated by a variety of endogenous factors and roles in embryonic stem (ES) cells has yet to be identified. Thus, we examined role of arachidonic acid (AA) in H(2)O(2)-induced proliferation of mouse ES cells and its related signaling molecules. AA release was maximally increased in response to 10(-4) M H(2)O(2) for 1 h. In addition, H(2)O(2) increased intracellular Ca(2+) concentration ([Ca(2+)](i)) and the phosphorylation of protein kinase C (PKC), p44/42, p38 mitogen-activated protein kinase (MAPK), and JNK/SAPK. Moreover, H(2)O(2) induced an increase in the phosphorylation of epidermal growth factor receptor (EGFR), which was blocked by the inhibition of p44/42 or p38 MAPKs. The inhibition of each signal molecule with specific inhibitors blocked H(2)O(2)-induced cytosolic phospholipase A(2) (cPLA(2)) activation and AA release. H(2)O(2) increased NF-kappaB phosphorylation to induce an increase in the levels of cyclooxygenase (COX)-2 proteins. Subsequently, H(2)O(2) stimulated PGE(2) synthesis, which was reduced by the inhibition of NF-kappaB activation. Moreover, each H(2)O(2) or PGE(2) increased DNA synthesis and the number of cells. However, H(2)O(2)-induced increase in DNA synthesis was inhibited by the suppression of cPLA(2) pathway. In conclusion, H(2)O(2) increased AA release and PGE(2) production by the upregulation of cPLA(2) and COX-2 via Ca(2+)/PKC/MAPKs and EGFR transactivation, subsequently proliferation of mouse ES cells.
authors.affiliation: Department of Veterinary Physiology, Biotherapy Human Resources Center (BK 21), College of Veterinary Medicine, Chonnam National University, Gwangju 500-757, South Korea.
authors.forename: Sang Hun
authors.initials: SH
authors.lastname: Lee
authors.forename: Sun Im
authors.initials: SI
authors.lastname: Na
authors.forename: Jung Sun
authors.initials: JS
authors.lastname: Heo
authors.forename: Min Hee
authors.initials: MH
authors.lastname: Kim
authors.forename: Yun Hee
authors.initials: YH
authors.lastname: Kim
authors.forename: Min Young
authors.initials: MY
authors.lastname: Lee
authors.forename: Seong Hong
authors.initials: SH
authors.lastname: Kim
authors.forename: Yun Jung
authors.initials: YJ
authors.lastname: Lee
authors.forename: Ho Jae
authors.initials: HJ
authors.lastname: Han
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D049109:Cell Proliferation; D051546:Cyclooxygenase 2 / Q000235:genetics*; D015232:Dinoprostone / Q000096:biosynthesis; D053595:Embryonic Stem Cells / Q000166:cytology*; D066246:ErbB Receptors / Q000235:genetics*; D006861:Hydrogen Peroxide / Q000378:metabolism; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D054467:Phospholipases A2 / Q000235:genetics*; D011493:Protein Kinase C / Q000378:metabolism; D015533:Transcriptional Activation
chemical_list: D016718:Arachidonic Acid; D006861:Hydrogen Peroxide; D051546:Cyclooxygenase 2; D066246:ErbB Receptors; D011493:Protein Kinase C; D020928:Mitogen-Activated Protein Kinases; D054467:Phospholipases A2; D015232:Dinoprostone; D002118:Calcium