Runx2+ Niche Cells Maintain Incisor Mesenchymal Tissue Homeostasis through IGF Signaling

Shuo Chen; Junjun Jing; Yuan Yuan; Jifan Feng; Xia Han; Quan Wen; Thach-Vu Ho; Chelsea Lee; Yang Chai

Cell Reports (Aug 2020)

Runx2+ Niche Cells Maintain Incisor Mesenchymal Tissue Homeostasis through IGF Signaling

Shuo Chen,
Junjun Jing,
Yuan Yuan,
Jifan Feng,
Xia Han,
Quan Wen,
Thach-Vu Ho,
Chelsea Lee,
Yang Chai

Affiliations

Shuo Chen: Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, CA 90033, USA; Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing 100081, China
Junjun Jing: Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, CA 90033, USA
Yuan Yuan: Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, CA 90033, USA
Jifan Feng: Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, CA 90033, USA
Xia Han: Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, CA 90033, USA
Quan Wen: Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, CA 90033, USA
Thach-Vu Ho: Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, CA 90033, USA
Chelsea Lee: Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA 90033, USA
Yang Chai: Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, CA 90033, USA; Corresponding author

Journal volume & issue: Vol. 32, no. 6
p. 108007

Abstract

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Summary: Stem cell niches provide a microenvironment to support the self-renewal and multi-lineage differentiation of stem cells. Cell-cell interactions within the niche are essential for maintaining tissue homeostasis. However, the niche cells supporting mesenchymal stem cells (MSCs) are largely unknown. Using single-cell RNA sequencing, we show heterogeneity among Gli1+ MSCs and identify a subpopulation of Runx2+/Gli1+ cells in the adult mouse incisor. These Runx2+/Gli1+ cells are strategically located between MSCs and transit-amplifying cells (TACs). They are not stem cells but help to maintain the MSC niche via IGF signaling to regulate TAC proliferation, differentiation, and incisor growth rate. ATAC-seq and chromatin immunoprecipitation reveal that Runx2 directly binds to Igfbp3 in niche cells. This Runx2-mediated IGF signaling is crucial for regulating the MSC niche and maintaining tissue homeostasis to support continuous growth of the adult mouse incisor, providing a model for analysis of the molecular regulation of the MSC niche.

Published in Cell Reports

ISSN: 2211-1247 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Science: Biology (General)
Website: http://www.cell.com/cell-reports/home

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