Comparative single-cell profiling reveals distinct cardiac resident macrophages essential for zebrafish heart regeneration
Abstract
Zebrafish exhibit a robust ability to regenerate their hearts following injury, and the immune system plays a key role in this process. We previously showed that delaying macrophage recruitment by clodronate liposome (-1d_CL, macrophage-delayed model) impairs neutrophil resolution and heart regeneration, even when the infiltrating macrophage number was restored within the first-week post injury (Lai et al., 2017). It is thus intriguing to learn the regenerative macrophage property by comparing these late macrophages vs. control macrophages during cardiac repair. Here, we further investigate the mechanistic insights of heart regeneration by comparing the non-regenerative macrophage-delayed model with regenerative controls. Temporal RNAseq analyses revealed that -1d_CL treatment led to disrupted inflammatory resolution, ROS homeostasis, and energy metabolism during cardiac repair. Comparative single-cell RNAseq profiling of inflammatory cells from regenerative vs. non-regenerative hearts further identified heterogeneous macrophages and neutrophils, showing alternative activation and cellular crosstalk leading to neutrophil retention and chronic inflammation. Among macrophages, two residential subpopulations (hbaa+ Mac 2 and timp4.3+ Mac 3) were enriched only in regenerative hearts and barely recovered after -1d_CL treatment. To deplete the resident macrophage without delaying the circulating macrophage recruitment, we established the resident macrophage-deficient model by administrating CL earlier at 8 days (-8d_CL) before cryoinjury. Strikingly, resident macrophage-deficient zebrafish still exhibited defects in revascularization, cardiomyocyte survival, debris clearance, and ECM remodeling/scar resolution without functional compensation from the circulating/monocyte-derived macrophages. Our results characterized the diverse function and interaction between inflammatory cells and identified unique resident macrophages prerequisite for zebrafish heart regeneration.
Data availability
All data generated or analyzed during this study have been included in the manuscript and uploaded to a public entry for raw reads of both bulk and single-cell RNAseq on NCBI SRA database (accession no. PRJNA900299). Source data files of respective figures have been provided.
Article and author information
Author details
Funding
Institute of Biomedical Sciences, Academia Sinica (IBMS-CRC108-P01)
- Shih-Lei Lai
Ministry of Science and Technology, Taiwan (MOST 108-2320-B-001-032-MY2)
- Shih-Lei Lai
Academia Sinica (AS-GC-110-P7)
- Shih-Lei Lai
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the Academia Sinica. All of the animals were handled according to approved institutional animal care and use committee (IACUC) protocols (Protocol ID: 18-12-1241) of Academia Sinica. The protocol was approved by the Committee on the Ethics of Animal Experiments of the Academia Sinica. All surgery was performed under tricaine anesthesia, and every effort was made to minimize suffering.
Copyright
© 2023, Wei et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.