Characterisation of Embryonic Dermal Precursor Cells

Abstract

Skin is an attractive organ for the acquisition of stem cells due to its accessibility, size and potential for autologous transplants. Research into skin development has implications for the isolation of stem cell populations, for example skin-derived precursors (SKPs), as well as the treatment of skin conditions, such as fibrosis.
This study centred on the early development, differentiation and stem cell potential of the dermis in embryonic mouse skin. Based on microarray data, the expression of specific Wnt family members was examined using RT-PCR and immunohistochemistry. No evidence of Wnt protein expression was observed in the dermis, but more embryonic stages and Wnt family members need to be explored to better understand Wnt signalling and its role in dermal development.
Our main focus was to investigate the plasticity of the common dermal fibroblast precursor population present at E13.5. We hypothesised that the dermis contains a common precursor capable of producing all cell types of the dermis and could harbour a high proportion of mesenchymal stem cell (MSC)-like precursors.
This E13.5 dermal cell (DC) population was investigated by exploring its differentiation potential when cultured in adipogenic and osteogenic media. These experiments indicated the E13.5 DCs contained a small subpopulation of MSC-like progenitors. However, when E13.5 DCs were cultured to produce SKPs and, subsequently, pushed to adipogenic and osteogenic lineages, they differentiated less than expected.
Most research regarding SKPs has used adult and older embryonic skin, therefore the findings here are novel in that SKPs were not expected at a younger age. However, RT-PCR revealed differences between the gene expression profiles of early and late embryonic dermal SKPs. Moreover, neither displayed the expected differentiation potential. The possible reasons for these unexpected findings include the potential role of hair follicle induction and/or a later migration of neural crest progenitors into the dermis.