In vivo Identification and Characterization of Synovial Membrane Mesenchymal Stem Cells

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

The use of mesenchymal stem cells (MSCs) as an alternative to mature cells for cell-based tissue repair is aggressively sought because more versatile and amenable to upscaling. We have identified and characterized multipotent MSCs from the adult human synovial membrane (SM). Such MSCs were derived from mixed populations of adherent SM cells following in vitro expansion. Expansion in mixed cell populations, however, alters the biological behaviour of SM MSCs and may be a source of variability in clinical applications. The purification of MSCs from the fresh SM digest, desirable to increase the consistency of MSC preparations and their efficacy, is currently impeded by the lack of specific markers.

In this project we propose a strategy to identify marker sets specific for uncultured SM MSCs, which would allow their direct purification from fresh SM digests as well as their identification in vivo within the tissue. To achieve this, we will sort the uncultured SM digest using combinations of negative markers (expressed by differentiated cell types) as well as positive candidate markers, associated with stem cells in other tissues/organs/systems. Individually, however, these markers are not specific for MSCs. To identify a specific MSC molecular profile, we will compare the transcriptome of the MSC-enriched fraction with that of the unsorted and negatively sorted (MSC-depleted) cell populations. These marker sets will be validated by comparing the purified cell populations with the unsorted cell populations for clonogenicity, kinetics of growth and multipotentcy using standardized quantitative in vitro and in vivo assays. The identified markers will also be used to localize the native MSCs within the intact SM and to investigate their stem cell function within the joint by prospectively monitoring their fate coupling cell-tracking techniques with marker analysis in a mouse model of mechanical joint surface injury.