| Autor: |
Dash, Rajesh, Schmidt, Albrecht G., Pathak, Anand, Gerst, Michael J., Biniakiewicz, Danuta, Kadambi, Vivek J., Hoit, Brian D., Abraham, William T., Kranias, Evangelia G. |
| Předmět: |
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| Zdroj: |
Cardiovascular Research; Mar2003, Vol. 57 Issue 3, p704, 11p |
| Abstrakt: |
Objective: Exogenous catecholamine exposure has been associated with p38 mitogen-activated protein kinase (MAPK) and cardiac hypertrophy. In this study, we investigated the regulation of p38 MAPK in cardiac remodeling elicited by endogenous adrenergic mechanisms. Methods: Transgenic male and female mice with fourfold phospholamban (PLB) overexpression exhibited enhanced circulating norepinephrine (NE), as a physiological compensatory mechanism to attenuate PLB’s inhibitory effects. This enhanced noradrenergic state resulted in left ventricular hypertrophy/dilatation and depressed function. Results: Male transgenics exhibited ventricular hypertrophy and mortality at 15 months, concurrent with cardiac p38 MAPK activation. Female transgenics, despite similar contractile dysfunction, displayed a temporal delay in p38 activation, hypertrophy, and mortality (22 months), which was associated with sustained cardiac levels of MAP Kinase Phosphatase-1 (MKP-1), a potent inhibitor of p38. At 22 months, decreases in cardiac MKP-1 were accompanied by increased levels of p38 activation. In vitro studies indicated that preincubation with 17-β-estradiol induced high MKP-1 levels, which precluded NE-induced p38 activation. Conclusion: These findings suggest that norepinephrine-induced hypertrophy is linked closely with p38 MAP kinase activation, which can be endogenously modulated through estrogen-responsive regulation of MKP-1 expression. [Copyright &y& Elsevier] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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