A ticking clock links metabolic pathways and organ systems function in health and disease.

Rhythmic variations with 24-h periodicity hallmark homeostatic regulation, metabolic processes and organ systems function, driven by a circadian timing system composed of central and peripheral oscillators. Recent reports suggest that disrupted circadian rhythmicity of physiology and behavior severely alters body homeostasis. Nuclear receptors and transcriptional regulators sense hormonal and metabolic cues and manage the rhythmic patterns of chromatin remodelling and gene expression, playing a key role in the cross talk between the circadian clock circuitry, the metabolic pathways and the organ systems. The alteration of this cross talk contributes to the pathophysiology of metabolic, degenerative, immune-related and neoplastic diseases.