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[摘要]：Celecoxib, a cyclooxygenase-2 (COX-2)-selective nonsteroidal anti-inflammatory drug, has been shown to inhibit Akt and prevent cardiac remodeling in aortic banding-induced failing heart in mice. However, it may be difficult to use celecoxib for the treatment of heart failure because of thromboembolic adverse reactions. Since 2,5-dimethyl (DM)-celecoxib, a derivative unable to inhibit COX-2, has been also reported to inhibit Akt, we attempted to examine whether DM-celecoxib retains the ability to prevent cardiac remodeling and improve cardiac functions using a mouse model of inherited dilated cardiomyopathy (DCM). DM-celecoxib as well as celecoxib administered daily for 4 weeks inhibited Akt and subsequent phosphorylation of glycogen synthase kinase-3 beta and mammalian target of rapamycin. Furthermore, both celecoxib and DM-celecoxib inhibited the activities of nuclear factor of activated T cell and beta-catenin and the expression of TCF7L2 (T-cell-specific transcriptional factor-7L2) and c-Myc, downstream mediators related to cardiac hypertrophy. Functional and morphological measurements showed that these compounds improved left ventricular systolic functions (ejection fraction: vehicle, 34.7 +/- 3.9%; 100 mg/kg celecoxib, 50.3 +/- 1.1%, p < 0.01; 100 mg/kg DM-celecoxib, 49.8 +/- 0.8%, p < 0.01), which was also evidenced by the decrease in beta-myosin heavy chain and B-type natriuretic peptide, and prevented hypertrophic cardiac remodeling (heart/body weight ratio: vehicle, 10.4 +/- 0.7 mg/g; 100 mg/kg celecoxib, 8.0 +/- 0.3 mg/g, p < 0.01; 100 mg/kg DM-celecoxib, 8.2 +/- 0.1 mg/g, p < 0.05). As a consequence, both compounds improved the survival rate (vehicle, 45%; 100 mg/kg celecoxib, 75%, p < 0.05; 100 mg/kg DM-celecoxib, 70%, p < 0.05). These results suggested that not only celecoxib but also DM-celecoxib prevents cardiac remodeling and reduces mortality in DCM through a COX-2-independent mechanism involving Akt and its downstream mediators. |
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