title: Targeting of Mesenchymal Stromal Cells by Cre-Recombinase Transgenes Commonly Used to Target Osteoblast Lineage Cells.
abstract: The targeting specificity of tissue-specific Cre-recombinase transgenes is a key to interpreting phenotypes associated with their use. The Ocn-Cre and Dmp1-Cre transgenes are widely used to target osteoblasts and osteocytes, respectively. Here, we used high-resolution microscopy of bone sections and flow cytometry to carefully define the targeting specificity of these transgenes. These transgenes were crossed with Cxcl12gfpmice to identify Cxcl12-abundant reticular (CAR) cells, which are a perivascular mesenchymal stromal population implicated in hematopoietic stem/progenitor cell maintenance. We show that in addition to osteoblasts, Ocn-Cre targets a majority of CAR cells and arteriolar pericytes. Surprisingly, Dmp1-Cre also targets a subset of CAR cells, in which expression of osteoblast-lineage genes is enriched. Finally, we introduce a new tissue-specific Cre-recombinase, Tagln-Cre, which efficiently targets osteoblasts, a majority of CAR cells, and both venous sinusoidal and arteriolar pericytes. These data show that Ocn-Cre and Dmp1-Cre target broader stromal cell populations than previously appreciated and may aid in the design of future studies. Moreover, these data highlight the heterogeneity of mesenchymal stromal cells in the bone marrow and provide tools to interrogate this heterogeneity. © 2016 American Society for Bone and Mineral Research.
authors.affiliation: Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Jingzhu
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Link
mesh_terms: D000818:Animals; D001160:Arterioles / Q000378:metabolism; D019070:Cell Lineage; D054377:Chemokine CXCL12 / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D019426:Integrases / Q000378:metabolism*; D059630:Mesenchymal Stem Cells / Q000378:metabolism*; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism; D009124:Muscle Proteins / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism*; D015675:Osteocalcin / Q000378:metabolism; D020286:Pericytes / Q000378:metabolism; D019076:Transgenes
chemical_list: D054377:Chemokine CXCL12; C513308:Dmp1 protein, mouse; D016326:Extracellular Matrix Proteins; D008840:Microfilament Proteins; D009124:Muscle Proteins; C051615:transgelin; D015675:Osteocalcin; C045073:Cre recombinase; D019426:Integrases
keywords: BONE HISTOMORPHOMETRY; GENETIC ANIMAL MODELS; OSTEOBLASTS; STROMAL/STEM CELLS