Contribution of GFP Expressing Dermal Papillae Cells to the Formation of Chimeric Embryos and their Survival in Uterine Environment

Aims: This is an innovative cell-based research project focused on the hair follicle dermal papillae (DP) as a source of key-element cells for regeneration of hair growth. DP is major dermal compartment which has a role in hair formation at embryogenesis and is able to differentiate down an endothelial lineage for in vitro functional assays. In the present study, we have tested the potential of DP cells from the lower end bulb region of hair follicles for multilineage differentiation in vivo. We have postulated that DP cells’ epigenetics can be changed under the influence of embryonic microenvironment when they are injected into early embryos which would demonstrate plasticity, regenerative and inductive properties of hair follicle dermal cells.

Study Design: Pilot research.

Place and Duration of Study: School of Biological and Biomedical Sciences, University of Durham, the UK, between February 2007 and December 2009.

Methodology: To identify the capacity of functional contribution to organogenesis we microinjected various numbers of Green Fluorescence Protein (GFP)-expressing Dermal Papillae cells (GFP-DP cells) into mice blastocysts and transferred embryos to the foster mothers for the generation of chimeric fetuses.

Results: GFP-expressing cells were detected in 3% of the epiblast egg cylinders formed from microinjected blastocysts cultured in absence or presence of mouse embryonic fibroblasts (MEFs). Surgical transfer of microinjected blastocysts resulted in 4.5% of fetuses developing fully. GFP- DP cell lineages were detected in tissue samples under fluorescence and confirmed immunohistochemically. Our finding displayed subcultural localization of GFP as a proof of chimaeric tissue from unborn pups carrying DP cell lineages which had multiplied in bone marrow, parenchyma and connective tissue, brain and hair bulbs.

Conclusion: The results confirm the capability of a small population of DP cells to convert into embryonic stem-like cells, multiply and contribute to organs and tissue. This makes them a reasonable source for regenerative studies and replacement therapy.