Substrate induction of osteogenesis from marrow-derived mesenchymal precursors

10.1089/scd.2005.14.632Stem Cells and Development146632-642SCDT

The osteoblast-heparan sulfate axis: Control of the bone cell lineage

10.1016/j.biocel.2005.03.006International Journal of Biochemistry and Cell Biology3791739-1745IJBB

Microscopic age changes in the human occipital bone

The value of histological examination of the human occipital bone for estimation of age-at-death was assessed. Undecalcified sections of occipital bone from eighteen male Caucasian subjects between the ages of 21 and 70 years were prepared for analysis using polarized light microscopy. The fractional volumes of primary osteons, secondary osteons, osteon fragments, and lamellar bone in both the outer and inner cortical tables were determined. It was found that with increasing age there is a decrease in the fractional volume of primary osteons and a significant decrease in the fractional volume of lamellar bone. The fractional volume of secondary osteons was not found to change significantly with age, while the fractional volume of osteon fragments significantly increases. The microscopic results reflect the continuous process of bone remodeling that is responsible for the variation in cortical parameters with age and is the primary basis for age predicting methods. While observable changes in the occipital bone do occur with increasing age, the amount of random variation in the parameters examined preclude their use for accurate age estimation

Heparan Sulfate Proteoglycans: Key Mediators of Stem Cell Function

10.3389/fcell.2020.581213Frontiers in Cell and Developmental Biology858121

New strategies for cartilage regeneration exploiting selected glycosaminoglycans to anhance cell fate determination.

Most research strategies for cartilage tissue engineering use extended culture with complex media loaded with costly GFs (growth factors) to drive tissue assembly and yet they result in the production of cartilage with inferior mechanical and structural properties compared with the natural tissue. Recent evidence suggests that GAGs (glycosaminoglycans) incorporated into tissue engineering scaffolds can sequester and/or activate GFs and thereby more effectively mimic the natural ECM (extracellular matrix). Such approaches may have potential for the improvement of cartilage engineering. However, natural GAGs are structurally complex and heterogeneous, making structure–function relationships hard to determine and clinical translation difficult. Importantly, subfractions of GAGs with specific chain lengths and sulfation patterns have been shown to activate key signalling processes during stem cell differentiation. In addition, recently, GAGs have been bound to synthetic biomaterials, such as electrospun scaffolds and hydrogels, in biologically active conformations, and methods to purify and select affinity-matched GAGs for specific GFs have also been developed. The identification and use of specific GAG moieties to promote chondrogenesis is therefore an exciting new avenue of research. Combining these with synthetic biomaterials may allow a more effective mimicry of the natural ECM, reduction in the need for expensive GFs, and perhaps the deposition of an articular cartilage-like matrix in a clinically relevant manner.</jats:p

Characterisation and differentiation of porcine bone marrow mesenchymal stem cells in 2D and 3D mPCL-TCP-collagen scaffolds

European Cells and Materials11SUPPL.282

Telomere length analysis of human mesenchymal stem cells by quantitative PCR

10.1016/j.gene.2013.01.039Gene5192348-355GENE

Glycosaminoglycan and growth factor mediated murine calvarial cell proliferation

Understanding the complex mechanisms underlying bone remodeling is crucial to the development of novel therapeutics. Glycosaminoglycans (GAGs) localised to the extracellular matrix (ECM) of bone are thought to play a key role in mediating aspects of bone development. The influence of isolated GAGs was studied by utilising in vitro murine calvarial monolayer and organ culture model systems. Addition of GAG preparations extracted from the cell surface of human osteoblasts at high concentrations (5 microg/ml) resulted in decreased proliferation of cells and decreased suture width and number of bone lining cells in calvarial sections. When we investigated potential interactions between the growth factors fibroblast growth factor-2 (FGF2), bone morphogenic protein-2 (BMP2) and transforming growth factor-beta1 (TGFbeta1) and the isolated cell surface GAGs, differences between the two model systems emerged. The cell culture system demonstrated a potentiating role for the isolated GAGs in the inhibition of FGF2 and TGFbeta1 actions. In contrast, the organ culture system demonstrated an enhanced stimulation of TFGbeta1 effects. These results emphasise the role of the ECM in mediating the interactions between GAGs and growth factors during bone development and suggest the GAG preparations contain potent inhibitory or stimulatory components able to mediate growth factor activity