STAT transcription in the ischemic heart

All seven STAT proteins are expressed in the heart, and in this review we will focus on their contribution to cardiac physiology and to ischemic heart disease and its consequences. A substantial literature has focused on the roles of STAT1 and STAT3 in ischemic heart disease, where, at least in the acute phase, they appear to have a yin-yang relationship. STAT1 contributes to the loss of irreplaceable cardiac myocytes both by increasing apoptosis and by reducing cardioprotective autophagy. In contrast, STAT3 is cardioprotective, since STAT3-deficient mice have larger infarcts following ischemic injury, and a number of cardioprotective agents have been shown to act, at least partly, through STAT3 activation. STAT3 is also absolutely required for preconditioning—a process where periods of brief ischemia protect against a subsequent or previous prolonged ischemic episode. Prolonged activation of STAT3, however, is strongly implicated in the post-infarction remodeling of the heart which leads to heart failure, where, possibly together with STAT5, it augments activation of the renin-angiotensin system.