⏰🫀 Does the heart care about the time of day? Yes—profoundly.
A new study in the Journal of Experimental Medicine reveals a circadian checkpoint in neutrophils that determines how much damage occurs after myocardial infarction. Morning ischemia triggers more injury, while nighttime CXCL12–CXCR4 signaling reprograms neutrophils, relocating them into the infarct core and sparing healthy myocardium—without impairing antimicrobial defense. 🌙🧬
This work reframes infarct biology from how much ischemia to when it happens and opens the door to chronotherapy for cardiovascular disease. Timing, it seems, is tissue. 🕰️✨
