Characterization of adhesion and differentiation markers of osteogenic marrow stromal cells

Abstract

Marrow stroma cells (MSC) play a major role in osteogenesis. The potential of the MSC to differentiate to bone-forming cells relies upon molecular regulation. This study analyzed MBA-15 cells for the expression of genes and proteins that are key regulators of osteoblast differentiation. These cells express Cbfa1 and c-fos transcription factors (TF) of osteoprogenitor proliferating cells. RT-PCR and immunohistochemistry were used to demonstrate the message and protein expression of extracellular matrix proteins that are a prerequisite for matrix formation and mineralization, including alkaline phosphatase (ALP), osteocalcin, osteopontin, biglycan, and bone sialoprotein (BSP). The activity of ALP was correlated at various cell densities with co-expression of osteocalcin or osteopontin. Adhering cells must attach to the appropriate matrix to enable survival and differentiation. Using attachment assays, we demonstrated that MBA-15 cells adhered to collagenous matrix and the effect on survival measured by changes in intracellular calcium (Ca) levels. The cells' adhesion to matrix is mediated via cell surface molecules. We quantified the expression of cells surface molecules that are important players in mediating cell-matrix interaction. Flow cytometry analysis (FACS) was used to determine the expression of CD-31 (36%), and lower levels were identified for CD-62E and CD11b. In summary, the present study demonstrates the expression of molecular markers that are distinctive for the osteoblastic phenotype in MBA-15 marrow stroma cells and have crucial role in cell-matrix interaction, in establishing the cellular osteogenic phenotype and their survival.

BMP2-loaded hollow hydroxyapatite microspheres exhibit enhanced osteoinduction and osteogenicity in large bone defects

“…As reported previously, [45][46] ALP activity is a biochemical marker for the differentiation of mesenchymal stem cells into an osteoblast phenotype and, accordingly, bone regeneration. The higher serum ALP level was detected as early as 4 weeks in the group of BMP2-loaded hollow HA microspheres compared with two other groups, showing the best therapeutic response in this group.…”

Osteogenic potency of human bone marrow mesenchymal stem cells from femoral atrophic non-union fracture site

“…[16] Alizarin red is a staining method to determine the presence of calcific deposition by cells of an osteogenic lineage during mineralization phase. It is an early stage marker of matrix mineralization [17][18].…”

Human Adipose Tissue-Derived SSEA-4 Subpopulation Multi-Differentiation Potential Towards the Endothelial and Osteogenic Lineages

“…Besides the expression ( > 90%) of CD90, CD73, and CD105 and the absence of CD34-and CD45-positive cells, these cells were able to differentiate, in addition to the endothelial lineage, into osteoblasts and chondrocytes (data not shown). The osteogenic differentiation of hASCs and SSEA-4 + hASCs was followed at the molecular and protein levels by the expression of the osteogenic-related markers (OCN and OPN) 58 and by subsequent deposition and mineralization of the extracellular matrix. For each cell population, the inverse expression profile of OPN and OCN, respectively, with higher levels at earlier and later time points, confirmed the expected progress of the osteogenic differentiation.…”