The fire within: cardiac inflammatory signaling in health and disease.

Inflammatory mediators are operative in the pathogenesis of the most common forms of heart disease. Although in most cases the induction of these pathways is maladaptive and deleterious, there are notable exceptions when inflammatory pathways participate in healing or limiting the extent of injury. The appreciation of the role of these mechanisms in myocardial homeostasis and pathophysiology has led to increased efforts to elucidate the specific signaling pathways most relevant to the heart. Our goal in this introductory overview is to provide context for the five detailed reviews that follow by introducing the major relevant stimuli, the receptors, and pathways that mediate inflammatory signaling in the heart. We try to impart a sense of the scope and complexity of these pathways, as well as their interactions with signaling pathways regulating cell survival and metabolism. These complexities underscore the potential challenges of therapeutically targeting inflammatory mechanisms in heart disease and may help explain the mostly disappointing results of this approach to date.