Fig. 8: Model of sleep fragmentation exacerbates myocardial ischemia‒reperfusion injury by promoting copper overload in cardiomyocytes.

Sleep fragmentation increases sympathetic innervation of the myocardium via SCG, releasing more norepinephrine, which indirectly inhibits VPS35 in cardiomyocytes, leading to ATP7A-associated impairment of copper transport, triggering intracellular copper overload and ultimately exacerbating myocardial ischemia-reperfusion injury. The figure was drawn by Figdraw (https://www.figdraw.com/#/) and Adobe Photoshop.