Overexpression of catalase delays G0/G1- to S-phase transition during cell cycle progression in mouse aortic endothelial cells
| Autor: | Ogbeyalu E. Onumah, ZhongMao Guo, Hong Yang, LiChun Zhou, Yanfeng Zhao, George E. Jules |
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| Rok vydání: | 2009 |
| Předmět: |
Cyclin-Dependent Kinase Inhibitor p21
Transgene Gene Expression Mice Transgenic Resting Phase Cell Cycle Biochemistry Article S Phase Flow cytometry Mice Cyclin-dependent kinase Physiology (medical) medicine Animals Humans Doubling time Aorta Cells Cultured Amitrole Cell Proliferation biology medicine.diagnostic_test Cell growth G1 Phase Free Radical Scavengers Hydrogen Peroxide Cell cycle Catalase Flow Cytometry Molecular biology Cyclin-Dependent Kinases Cell biology Endothelial stem cell biology.protein Endothelium Vascular Cyclin-Dependent Kinase Inhibitor p27 Signal Transduction |
| Zdroj: | Free Radical Biology and Medicine. 46:1658-1667 |
| ISSN: | 0891-5849 |
| Popis: | Although it is understood that hydrogen peroxide (H(2)O(2)) promotes cellular proliferation, little is known about its role in endothelial cell cycle progression. To assess the regulatory role of endogenously produced H(2)O(2) in cell cycle progression, we studied the cell cycle progression in mouse aortic endothelial cells (MAECs) obtained from mice overexpressing a human catalase transgene (hCatTg), which destroys H(2)O(2). The hCatTg MAECs displayed a prolonged doubling time compared to wild-type controls (44.0 +/- 4.7 h versus 28.6 +/- 0.8 h, p0.05), consistent with a diminished growth rate and H(2)O(2) release. Incubation with aminotriazole, a catalase inhibitor, prevented the observed diminished growth rate in hCatTg MAECs. Inhibition of catalase activity with aminotriazole abrogated catalase overexpression-induced antiproliferative action. Flow cytometry analysis indicated that the prolonged doubling time was principally due to an extended G(0)/G(1) phase in hCatTg MAECs compared to the wild-type cells (25.0 +/- 0.9 h versus 15.9 +/- 1.4 h, p0.05). The hCatTg MAECs also exhibited decreased activities of the cyclin-dependent kinase (Cdk) complexes responsible for G(0)/G(1)- to S-phase transition in the cell cycle, including the cyclin D-Cdk4 and cyclin E-Cdk2 complexes. Moreover, the reduction in cyclin-Cdk activities in hCatTg MAECs was accompanied by increased protein levels of two Cdk inhibitors, p21 and p27, which inhibit the Cdk activity required for the G(0)/G(1)- to S-phase transition. Knockdown of p21 and/or p27 attenuated the antiproliferative effect of catalase overexpression in MAECs. These results, together with the fact that catalase is an H(2)O(2) scavenger, suggest that endogenously produced H(2)O(2) mediates MAEC proliferation by fostering the transition from G(0)/G(1) to S phase. |
| Databáze: | OpenAIRE |
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