The cardioprotective agent urocortin induces expression of CT-1

The corticotrophin-releasing hormone-related factor, urocortin (Ucn) and the interleukin (IL)-6 family cytokine cardiotrophin-1 (CT-1) are both cardioprotective agents able to protect the heart from ischemic damage. In both cases the protective effect involves activation of the p42/p44 MAPK and PI-3 kinase/Akt pathways, but the protective effect of Ucn requires de novo protein synthesis whereas that of CT-1 does not. In this study, we show that Ucn induces enhanced expression of CT-1 at both the mRNA and protein levels. This effect is mediated by activation of the CT-1 gene promoter and requires the transcription factor C/EBPbeta/NF-IL6. Hence, a specific cardioprotective factor can induce enhanced expression of another cardioprotective factor belonging to an unrelated protein family.