Background: Erythropoietin (EPO) can reduce myocardial ischemia/reperfusion (I/R) injury. However, the cellular mechanisms have not been elucidated entirely. The present study was to investigate whether transcription factor GATA-4 could be involved in EPO-induced cardioprotection when it was administered after ischemia, immediately before reperfusion. Methods and results: Male Balb/c mice treated with or without EPO were subjected to ischemia (45 min) followed by reperfusion (4 h). TTC staining showed that the infarct size in EPO-treated mice was significantly reduced compared with untreated I/R mice (P < 0.05). Echocardiography examination suggested that EPO administration significantly improved cardiac function following I/R. TUNEL assay indicated that EPO treatment decreased apoptosis. EPO administration also significantly increased the level of nuclear GATA-4 phosphorylation in the myocardium which was positively correlated with the reduction of myocardial infarction. In vitro hypoxia/re-oxygenation study showed that EPO treatment increased the levels of phospho-GATA-4 and decreased cardiomyocyte apoptosis. More significantly, blocking GATA-4 by transfection of a dominant-negative form of GATA-4 (dnGATA-4) abolished EPO-induced cardioprotective effects. Conclusion: EPO administration after ischemia, just before reperfusion induced cardioprotection and stimulated GATA-4 phosphorylation. Activation of GATA-4 may be one of the mechanisms by which EPO induced protection against myocardial I/R injury.
| Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-18397 |
| Date | 29 May 2009 |
| Creators | Shan, Xiaohong, Xu, Xuan, Cao, Bin, Wang, Yongmei, Guo, Lin, Zhu, Quan, Li, Jing, Que, Linli, Chen, Qi, Ha, Tuanzhu, Li, Chuanfu, Li, Yuehua |
| Publisher | Digital Commons @ East Tennessee State University |
| Source Sets | East Tennessee State University |
| Detected Language | English |
| Type | text |
| Source | ETSU Faculty Works |
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