Vagal neuroimmune axis modulates heart failure by limiting monocyte-derived inflammatory CCRL2 macrophage

Autonomic neuronal dysfunction is associated with heart failure (HF). Here, we report that targeted vagal nerve stimulation (VNS) using optogenetics attenuates cardiac remodelling and HF induced by pressure overload. Unbiased approaches revealed that VNS decreased the proportion of the Ccrl2+ macrophage subset, which derived from myeloid monocytes and exhibited a distinct tumour necrosis factor-alpha (TNFα)-responsive, pro-hypertrophic, and profibrotic signature. Elimination of Ccrl2+ macrophages prevented cardiac remodelling and HF. Functional characterisation by Ccrl2+ macrophage-specific overexpression or global genetic loss of α7 nicotinic acetylcholine receptor (α7nAChR) highlighted its crucial contribution to VNS-mediated cardioprotection. Mechanistically, activation of α7nAChR inhibited the TNFα responsiveness through upregulated expression of the transcription factor NRF2. Cardiac Ccrl2+ macrophages and TNFα-responsive proteins were positively correlated with cardiac remodelling and dysfunction in humans. Finally, an α7nAChR agonist effectively blocked the development of HF. These results suggest that the vagal neuroimmune axis modulates heart failure and is a promising target for treatment. To explore this phenomenon, we isolated four macrophage subsets from the hearts of Ctrl-TAC mice and performed bulk transcriptome profiling.