Arachidonic acid release by H2O2 mediated proliferation of mouse embryonic stem cells: involvement of Ca2+/PKC and MAPKs-induced EGFR transactivation.
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.
Lee
Sang Hun
SH
Department of Veterinary Physiology, Biotherapy Human Resources Center (BK 21), College of Veterinary Medicine, Chonnam National University, Gwangju 500-757, South Korea.
Na
Sun Im
SI
Heo
Jung Sun
JS
Kim
Min Hee
MH
Kim
Yun Hee
YH
Lee
Min Young
MY
Kim
Seong Hong
SH
Lee
Yun Jung
YJ
Han
Ho Jae
HJ
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
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