Bone marrow subendosteal microenvironment harbours functionally distinct haemosupportive stromal cell populations.
In adult animals, bone marrow is the major site of blood cell production, which is controlled by interactions between the local stroma and blood cell progenitors. The endosteal/subendosteal environment comprises bone-lining and adjacent reticular cells and sustains haemopoietic stem cell (HSC) self-renewal, proliferation and differentiation. We have questioned the specific role of each of these stroma cells in controlling HSC fate. We have isolated two distinct stroma-cell populations containing subendosteal reticulocytes (F-RET) and osteoblasts (F-OST) from periosteum-free fragments of murine femurs by a two-step collagenase-digestion procedure. Both populations produce similar extracellular matrix (collagen I, laminin, fibronectin, decorin), except for collagen IV, which is low in F-OST. They also express osteogenic markers: osteopontin, osteonectin, bone sialoprotein and alkaline phosphatase (ALP). The quantity and activity of ALP are however higher in F-OST. When co-cultured with bone marrow mononuclear cells or lineage-negative haemopoietic progenitors, F-OST stroma induces low proliferation and high maintenance of early haemopoietic progenitors, whereas F-RET stroma induces high short-term proliferation and differentiation. Analysis by reverse transcription/polymerase chain reaction has revealed higher levels of Jagged-1 expression by F-OST cells than by the F-RET population. Thus, two adjacent stroma cells (subendosteal and endosteal) play distinct roles in controlling the stem-cell capacity and fate of HSC and probably contribute distinctly to HSC niche formation.
Balduino
Alex
A
Departamento de Histologia e Embriologia, Instituto de Ciências Biomédicas, Cidade Universitária, 21941-970, Rio de Janeiro, Brasil.
Hurtado
Sandra P
SP
Frazão
Priscilla
P
Takiya
Christina M
CM
Alves
Leandro M
LM
Nasciutti
Luiz-Eurico
LE
El-Cheikh
Márcia C
MC
Borojevic
Radovan
R
D000469:Alkaline Phosphatase / Q000032:analysis / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001854:Bone Marrow Cells / Q000378:metabolism* / Q000648:ultrastructure; D002454:Cell Differentiation; D002478:Cells, Cultured; D018920:Coculture Techniques; D017364:Collagenases / Q000494:pharmacology; D004727:Endothelium / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D005269:Femur / Q000166:cytology / Q000187:drug effects / Q000648:ultrastructure; D019084:Fluorescent Antibody Technique, Indirect; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000648:ultrastructure; D007150:Immunohistochemistry; D051379:Mice; D008807:Mice, Inbred BALB C; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017154:Stromal Cells / Q000378:metabolism* / Q000648:ultrastructure; D014357:Trypsin / Q000494:pharmacology
D015415:Biomarkers; D000469:Alkaline Phosphatase; D014357:Trypsin; D017364:Collagenases