A triple-node heart-brain neuroimmune loop underlying myocardial infarction.

Myocardial infarction (MI) triggers adverse cardiac events, immune responses, and nervous system activation, but the neural and neuroimmune mechanisms remain understudied. Using single-cell RNA sequencing (scRNA-seq) and tissue clearing, we identified transient receptor potential vanilloid-1 (TRPV1)-expressing vagal sensory neurons (VSNs) that increase ventricular innervation post MI. Ablating these VSNs mitigated MI pathology, reducing infarct size, abnormal electrocardiograms, cardiac dysfunction, sympathetic innervation, and pro-inflammatory cytokine interleukin 1β (IL-1β). Single-nuclei RNA-seq (snRNA-seq) and spatial transcriptomics revealed reduced border zone expansion in MI hearts following VSN ablation. Tracing the effects to the brain, we found that MI activated angiotensin II receptor type 1 (AT1aR)-expressing neurons in the paraventricular nucleus (PVN), whose inhibition mirrored benefits of TRPV1 VSN ablation. Additionally, the superior cervical ganglia (SCGs) exhibited intensified post-MI sympathetic innervation and IL-1β signaling. Blocking IL-1β in the SCG significantly reduced complications post MI. This study reveals a triple-node heart-brain loop underlying MI and potential therapeutic targets.