Identification of HSC/MPP expansion units in fetal liver by single-cell spatiotemporal transcriptomics

• 作者: Suwei Gao Qiang Shi Yifan Zhang Guixian Liang Zhixin Kang Baofeng Huang Dongyuan Ma Lu Wang Jianwei Jiao Xiangdong Fang Cheng-Ran Xu Longqi Liu Xun Xu Berthold G(o)ttgens Cheng Li Feng Liu
• 来源期刊: 细胞研究（英文版）
• 年，卷（期）: 2022,（1）
• 所属期刊栏目: ARTICLES
• 页码范围: 38-53
• 页数: 16页
• 语种: 英文

摘要

Limited knowledge of cellular and molecular mechanisms underlying hematopoietic stem cell and multipotent progenitor (HSC/MPP)expansion within their native niche has impeded the application of stem cell-based therapies for hematological malignancies.Here,we constructed a spatiotemporal transcriptome map of mouse fetal liver (FL) as a platform for hypothesis generation and subsequent experimental validation of novel regulatory mechanisms.Single-cell transcriptomics revealed three transcriptionally heterogeneous HSC/MPP subsets,among which a CD93-enriched subset exhibited enhanced stem cell properties.Moreover,by employing integrative analysis of single-cell and spatial transcriptomics,we identified novel HSC/MPP 'pocket-like'units (HSC PLUS),composed of niche cells(hepatoblasts,stromal cells,endothelial cells,and macrophages) and enriched with growth factors.Unexpectedly,macrophages showed an 11-fold enrichment in the HSC PLUS.Functionally,macrophage-HSC/MPP co-culture assay and candidate molecule testing,respectively,validated the supportive role of macrophages and growth factors (MDK,PTN,and IGFBPS) in HSC/MPP expansion.Finally,cross-species analysis and functional validation showed conserved cell-cell interactions and expansion mechanisms but divergent transcriptome signatures between mouse and human FL HSCs/MPPs.Taken together,these results provide an essential resource for understanding HSC/MPP development in FL,and novel insight into functional HSC/MPP expansion ex vivo.