From classical signaling pathways to the nucleus

Abstract The second messengers calcium (Ca2 +) and cyclic 3′-5′-cyclic adenosine monophosphate (cAMP) govern biological processes in mammalian cells including cardiomyocytes. Despite the well-known central and antagonistic roles for fundamental processes such as fertilization and differentiation, the contribution of Ca2 + and cAMP to cardiomyocyte function has typically focused on effector proteins regulating inotropy, chronotropy, or dromotropy of the heart and has rather been considered to be synergistic. Fundamental processes in mammalian cells are also governed by epigenetic reprogramming. In recent years, epigenetic profiling of cardiomyocytes advanced our understanding of cardiomyocyte biology and has revealed important cross talks between central cellular processes. In this chapter, we will summarize recent discoveries highlighting epigenetic regulation of Ca2 +- and cAMP-dependent gene signatures that appear to antagonistically regulate cardiac function (outlined in Fig. 3.1).