Journal Investigative Dermatologyl Symp Proc 1999 Dec;4(3):290-5
In vitro main pathways of steroid
action in cultured hair follicle cells: vascular approach.
Lachgar S, Charveron M, Sarraute J, Mourard M, Gall Y, Bonafe JL.
Laboratoire de Biologie Cellulaire Cutanee, Institut de Recherche Pierre Fabre, Faculte de Medecine Rangueil, Toulouse, France. souad.lachgar@pierre-fabre.com
The known role of steroids on the
hair follicle leads us to investigate their effects on hair follicle cell angiogenic
responses in vitro. We verified, using the immunohistochemical technique, whether
human occipital scalp follicle cells express steroid receptors in vitro. We
showed that androgen and estrogen receptors were expressed by dermal papilla
cells (DPC) and keratinocytes from the outer root sheath in vitro. With regard
to steroidal enzymes (type I and II 5alpha-reductases and Cytochrome-p-450-aromatase),
the type I 5alpha-reductase gene is much more expressed in DPC than in dermal
fibroblasts; however, the type II 5a-reductase gene is transcribed more in dermal
fibroblasts than in DPC. The transcription of the two 5alpha-reductase isoform
genes in cultured DPC is regulated by a 5alpha-reductase inhibitor. We also
demonstrated that DPC, dermal fibroblasts, and outer root shealth keratinocytes
expressed cytochrome-p-450-aromatase. Using ELISA and reverse transcriptase-polymerase
chain reaction, we investigated the role played by some steroids (estrogens,
androgens, antiandrogens) in the modulation of vascular endothelial growth factor
(VEGF) expression by DPC. The association of different treatments of DPC (5alpha-reductase
inhibitor and androgen receptor antagonist) shows a great stimulation of VEGF
and aromatase expression. Strong stimulation of VEGF protein and gene expression
is observed in the presence of 17beta-estradiol. Also, the concentration-dependent
inhibition of VEGF expression by DPC using the cytochrome-p-450-aromatase inhibitor,
confirms the involvement of this estrogenic pathway in the regulation of VEGF
expression in vitro.