| Autor: |
Zhao, Jing, Renner, Oliver, Wightman, Lionel, Sugden, Peter H., Stewart, Luisa, Miller, Andrew D., Latchman, David S., Marber, Michael S. |
| Zdroj: |
Journal of Biological Chemistry; September 1998, Vol. 273 Issue: 36 p23072-23079, 8p |
| Abstrakt: |
The role of protein kinase C (PKC) in ischemic preconditioning remains controversial because of difficulties with both its measurement and pharmacological manipulation. We investigated preconditioning in isolated neonatal rat cardiocytes by expressing constitutively active isotypes of PKC. Observations at differing durations of simulated ischemia suggested β-galactosidase (β-gal) activity reflected viability within transfected myocytes. Preconditioning with 90 min of ischemia significantly increased β-gal activity and myocyte survival after 6 h of ischemia; an effect abolished by PKC inhibitors. After co-transfection with plasmids encoding β-gal and either constitutively active mutants of PKC-δ, PKC-α, wild type PKC-δ, or empty vector, cardiocytes were subjected to 6 h of ischemia. Only PKC-δ, rendered constitutively active by a limited deletion within the pseudosubstrate domain, consistently increased resistance to simulated ischemia (β-gal activity was 85.6 ± 11.9% versus53.7 ± 6.5% (p≤ 0.01) and dead myocytes 46.8 ± 3.4%versus68.7 ± 2.8% (p≤ 0.01)). Since transfection was apparent in only 5–12% of cells, the results suggested a protective bystander effect that was confirmed by co-culture of transfected myocytes with untransfected myocytes. In neonatal cardiocytes expression of active PKC-δ increases resistance to simulated ischemia. This observation may provide further insight into the mechanism and possible avenues for therapeutic exploitation of preconditioning. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
