Expression of immediate-early genes in response to ischemia/reperfusion has been reported, but little is known about the role of transcription factors that may regulate the gene expression. NF-κB is a critical regulator of many immediate-early gene-expression involved in immune responses, inflammatory reaction, and defense mechanisms. Isolated perfused rat hearts subjected to 0, 1, 2, 3, 4, 5, 7.5, 10, 15, and 30 min of global normothermic ischemia were used to study the activation and translocation of NF-κB. Western blot shows that cytoplasmic IκBα levels were reduced at 3 min of ischemia and markedly diminished by ischemia for 5 min, but were rapidly returned at 15 min after ischemia. Electrophoretic mobility shift assay using nuclear extract indicated NF-κB binding activity began at 3 min, peaked around 5 min, and persisted up to 30 min of myocardial ischemia. Concurrent to the disappearance of cytoplasmic IκBα protein, the NF-κB was activated and translocated to the nucleus. Pyrrolidine dithiocarbamate, an antioxidant, significantly inhibited the cytoplasmic IκBα disappearance and prevented the activation of NF-κB. The results suggest that ischemia rapidly induced NF-κB activation by dissociating its inhibitor IκBα. The activation of NF-κB which can be prevented by antioxidant indicates the reactive oxygen intermediates may serve as messengers.
| Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-14738 |
| Date | 01 December 1997 |
| Creators | Li, C., Ha, T., Williams, M., Messerschmidt, W., Kao, R. L. |
| 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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