Compared with naturally aged intervertebral discs, degenerated discs exhibit significantly upregulated gene expression levels of NPY and its receptors Y1R/Y2R, indicating that neuropeptide signaling plays a crucial role in the disc degeneration process.143 Further investigations have revealed that under pathological stimuli such as inflammatory factors (e.g., IL-1β) and abnormal mechanical stress, NPY synthesis is increased and Y1R expression is upregulated in AF cells.144 NPY demonstrates protective effects against degeneration. Here, NPY is linked to atrial fibrillation.