Single-cell multiomic analysis identifies macrophage subpopulations in promoting cardiac repair
Mingzhu Fu, Shengtao Jia, Longhui Xu, Xin Li, Yufang Lv, Yulong Zhong, Shanshan Ai
Mingzhu Fu, Shengtao Jia, Longhui Xu, Xin Li, Yufang Lv, Yulong Zhong, Shanshan Ai
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Research Article Cardiology

Single-cell multiomic analysis identifies macrophage subpopulations in promoting cardiac repair

Abstract

Cardiac mononuclear phagocytic cells (Cardiac MPCs) participate in maintaining homeostasis and orchestrating cardiac responses upon injury. However, the function of specific MPC subtypes and the related cell fate commitment mechanisms remain elusive in regenerative and nonregenerative hearts due to their cellular heterogeneities. Using spatiotemporal single-cell epigenomic analysis of cardiac MPCs in regenerative (P1) and nonregenerative (P10) mouse hearts after injury, we found that P1 hearts accumulate reparative Arg1+ macrophages, while proinflammatory S100a9+Ly6c+ monocytes are uniquely abundant during nonregenerative remodeling. Moreover, blocking chemokine CXCR2 to inhibit the specification of the S100a9+Ly6c+-biased inflammatory fate in P10 hearts resulted in elevated wound repair responses and marked improvements in cardiac function after injury. Single-cell RNA-Seq further confirmed an increased Arg1+ macrophage subpopulation after CXCR2 blockade, which was accomplished by increased expression of wound repair–related genes and reduced expression of proinflammatory genes. Collectively, our findings provide instructive insights into the molecular mechanisms underlying the function and fate specification of heterogeneous MPCs during cardiac repair and identify potential therapeutic targets for myocardial infarction.

Authors

Mingzhu Fu, Shengtao Jia, Longhui Xu, Xin Li, Yufang Lv, Yulong Zhong, Shanshan Ai

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Figure 11

Single-cell H3K27ac ChIP-Seq of macrophages/monocytes in adult hearts at 3 and 7 days after MI/sham.

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Single-cell H3K27ac ChIP-Seq of macrophages/monocytes in adult hearts at...
(A) Schematic representation of the experimental design. (B) UMAP plot of 4,613 cardiac CD45+F4/80+ mononuclear phagocytic cells from adult hearts 3 and 7 days after MI/sham identified 7 clusters. (C) Genome browser view of H3K27ac signals around cluster-specific marker genes. (D) Bar plot showing proportions of each cluster according to experimental conditions. (E) Heatmap displaying the fraction of cells in each adult cluster linked to corresponding P1/P10 H3K27ac ChIP-identified clusters through integration by Seurat V3. The color bar represents values normalized by z score for each column. (F) UMAP showing P1/P10 ChIP-identified monocyte-related clusters embedding onto the adult scChIP-Seq UMAP. (G and H) Representative immunostaining (G) and quantification (H) of ARG1+F4/80+ cells in the IZ of Adult-MI_3D hearts. (I and J) Representative immunostaining (I) and quantification (J) of S100A9+F4/80+ cells in the IZ of Adult-MI_3D hearts. (K and L) Ternary plot showing stage-specific enhancer activities of genes involved in wound healing (K) and proinflammatory activities (L) in C4 and C6, respectively. The red dashed line represents the central axis between P1 and adult stages and the circles represent genes. (M and N) Dot plots displaying the enhancer activities of representative genes related to wound healing functions in Arg1+ IMφ (M) and proinflammatory functions in S100a9+Ly6c+ IMo (N) among 3 stages. Scale bar: 50 μM. n = 5 mice per experimental group. The P value was determined by unpaired 2-tailed Student’s t test. Data represent mean ± SEM. ***P < 0.001.