The Effect of Ovine Secreted Soluble Factors on Human Dermal Papilla Cell Aggregation.
BACKGROUND
In androgenetic alopecia, follicular miniaturization and dynamic changes to the hair cycle produce patterned baldness. The most effective treatment for baldness is hair transplantation surgery. The major limitation to hair transplantation is the availability of donor hair from the relatively unaffected occipital scalp. Hair induction with in vitro expansion of donor follicle populations has the potential to overcome this. The major obstacle to this is that in vitro expansion of human dermal papilla cell (DPC) colonies is associated with irreversible loss of aggregative behavior and hair follicle-inductive potential. In contrast, cultured ovine DPCs maintain these properties after extensive proliferation.


OBJECTIVE
To determine whether aggregating ovine DPC secrete factors that enhance the aggregative behavior or inductive potential of human DPC.


METHODS
Fluorescently-labelled ovine DPC were mixed in culture with human DPC at passage number seven-nine, which had lost their aggregative behavior. The effects of different culture substrates and medium compositions on aggregative behavior were determined. Ovine and human papilla cells were co-cultured, separated by a permeable membrane to determine whether the ovine cells secrete soluble factors that affect human papilla cells.


RESULTS
In direct co-culture experiments, well-formed aggregates were produced by 90:10 human:ovine and 50:50 human:ovine DPC mixtures. In contrast, unmixed human DPC remained in a monolayer state after 18 days. Both human and ovine DPC had a higher tendency to aggregate in medium containing 20% (v/v) lamb serum (LS) compared to 10% (v/v) fetal calf serum (FCS). In co-culture experiments separated with permeable membrane, the human DPC aggregates were bigger and more rapidly formed with the addition of ovine secreted soluble factors.


CONCLUSIONS
Soluble factors secreted by ovine DPC and present in LS increase the aggregative behavior of human DPC. These molecules might improve follicle inductiveness of human DPCs for the purpose of hair replacement therapy.
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, Australia.
Nicholas Wolfgang
NW
Rufaut
Department of Medicine, University of Melbourne, Parkville, Australia; Department of Dermatology, Epworth Hospital, Melbourne, Australia.
Leslie Norman
LN
Jones
Department of Medicine, University of Melbourne, Parkville, Australia; Department of Dermatology, Epworth Hospital, Melbourne, Australia.
Rodney Daniel
RD
Sinclair
Dermal papilla cells; human; ovine