Characterization of Ovine Dermal Papilla Cell Aggregation.
BACKGROUND
The dermal papilla (DP) is a condensation of mesenchymal cells at the proximal end of the hair follicle, which determines hair shaft size and regulates matrix cell proliferation and differentiation. DP cells have the ability to regenerate new hair follicles. These cells tend to aggregate both in vitro and in vivo. This tendency is associated with the ability of papilla cells to induce hair growth. However, human papilla cells lose their hair-inducing activity in later passage number. Ovine DP cells are different from human DP cells since they do not lose their aggregative behavior or hair-inducing activity in culture. Nonetheless, our understanding of ovine DP cells is still limited.


OBJECTIVE
The aim of this study was to observe the expression of established DP markers in ovine cells and their association with aggregation.


METHODS
Ovine DP cells from three different sheep were compared. Histochemistry, immunoflourescence, and polymerase chain reaction experiments were done to analyze the DP markers.


RESULTS
We found that ovine DP aggregates expressed all the 16 markers evaluated, including alkaline phosphatase and versican. Expression of the versican V0 and V3 isoforms, neural cell adhesion molecule, and corin was increased significantly with aggregation, while hey-1 expression was significantly decreased.


CONCLUSIONS
Overall, the stable expression of numerous markers suggests that aggregating ovine DP cells have a similar phenotype to papillae in vivo. The stability of their molecular phenotype is consistent with their robust aggregative behavior and retained follicle-inducing activity after prolonged culture. Their phenotypic stability in culture contrasts with DP cells from other species, and suggests that a better understanding of ovine DP cells might provide opportunities to improve the hair-inducing activity and therapeutic potential of human cells.
Department of Medicine, University of Melbourne, Parkville, Australia.
Agnes Rosarina Prita
AR
Sari
Department of Medicine, University of Melbourne, Parkville, Australia; Department of Dermatology, Epworth Hospital, Melbourne, Victoria, Australia.
Nicholas Wolfgang
NW
Rufaut
Department of Medicine, University of Melbourne, Parkville, Australia; Department of Dermatology, Epworth Hospital, Melbourne, Victoria, Australia.
Leslie Norman
LN
Jones
Department of Medicine, University of Melbourne, Parkville, Australia; Department of Dermatology, Epworth Hospital, Melbourne, Victoria, Australia.
Rodney Daniel
RD
Sinclair
Aggregation; dermal papilla cells; ovine; versican