Cargando…

Osteogenic Factor Runx2 Marks a Subset of Leptin Receptor-Positive Cells that Sit Atop the Bone Marrow Stromal Cell Hierarchy

Bone marrow mesenchymal stem and progenitor cells (BM-MSPCs) maintain homeostasis of bone tissue by providing osteoblasts. Although several markers have been identified for labeling of MSPCs, these labeled cells still contain non-BM-MSPC populations. Studies have suggested that MSPCs are observed as...

Descripción completa

Detalles Bibliográficos
Autores principales: Yang, Mengyu, Arai, Atsushi, Udagawa, Nobuyuki, Hiraga, Toru, Lijuan, Zhao, Ito, Susumu, Komori, Toshihisa, Moriishi, Takeshi, Matsuo, Koichi, Shimoda, Kouji, Zahalka, Ali H., Kobayashi, Yasuhiro, Takahashi, Naoyuki, Mizoguchi, Toshihide
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5503992/
https://www.ncbi.nlm.nih.gov/pubmed/28694469
http://dx.doi.org/10.1038/s41598-017-05401-1
Descripción
Sumario:Bone marrow mesenchymal stem and progenitor cells (BM-MSPCs) maintain homeostasis of bone tissue by providing osteoblasts. Although several markers have been identified for labeling of MSPCs, these labeled cells still contain non-BM-MSPC populations. Studies have suggested that MSPCs are observed as leptin receptor (LepR)-positive cells, whereas osteoblasts can be classified as positive for Runx2, a master regulator for osteoblastogenesis. Here, we demonstrate, using Runx2-GFP reporter mice, that the LepR-labeled population contains Runx2-GFP(low) sub-population, which possesses higher fibroblastic colony-forming units (CFUs) and mesensphere capacity, criteria for assessing stem cell activity, than the Runx2-GFP(−) population. In response to parathyroid hormone (PTH), a bone anabolic hormone, LepR(+)Runx2-GFP(low) cells increase Runx2 expression and form multilayered structures near the bone surface. Subsequently, the multilayered cells express Osterix and Type I collagen α, resulting in generation of mature osteoblasts. Therefore, our results indicate that Runx2 is weakly expressed in the LepR(+) population without osteoblastic commitment, and the LepR(+)Runx2-GFP(low) stromal cells sit atop the BM stromal hierarchy.