Osterix enhances proliferation and osteogenic potential of bone marrow stromal cells.
Osterix (Osx) is a zinc-finger-containing transcription factor that is expressed in osteoblasts of all endochondral and membranous bones. In Osx null mice osteoblast differentiation is impaired and bone formation is absent. In this study, we hypothesized that overexpression of Osx in murine bone marrow stromal cells (BMSC) would be able to enhance their osteoblastic differentiation and mineralization in vitro. Retroviral transduction of Osx in BMSC cultured in non-differentiating medium did not affect expression of Runx2/Cbfa1, another key transcription factor of osteoblast differentiation, but induced an increase in the expression of other markers associated with the osteoblastic lineage including alkaline phosphatase, bone sialoprotein, osteocalcin, and osteopontin. Retroviral transduction of Osx in BMSC also increased their proliferation, alkaline phosphatase activity, and ability to form bone nodules. These events occurred without significant changes in the expression of alpha1(II) procollagen or lipoprotein lipase, which are markers of chondrogenic and adipogenic differentiation, respectively.
Tu
Qisheng
Q
Division of Oral Biology, Tufts University School of Dental Medicine, Boston, MA 02111, USA.
Valverde
Paloma
P
Chen
Jake
J
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology* / Q000187:drug effects*; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D050659:Core Binding Factor Alpha 1 Subunit / Q000096:biosynthesis; D051379:Mice; D010012:Osteogenesis / Q000187:drug effects*; D000076182:Sp7 Transcription Factor; D017154:Stromal Cells / Q000166:cytology* / Q000187:drug effects*; D014157:Transcription Factors / Q000096:biosynthesis / Q000502:physiology*; D014161:Transduction, Genetic
D050659:Core Binding Factor Alpha 1 Subunit; C493716:Runx2 protein, mouse; D000076182:Sp7 Transcription Factor; C479466:Sp7 protein, mouse; D014157:Transcription Factors; D000469:Alkaline Phosphatase