Recently several investigators have reported that endothelin(ET)-1 is produced and secreted from the human keratinocytes and playing an essential role for maintaining the melanocyte proliferation and melanization in the epidermis as a paracrine
effect.
This study is designed to investigate function of ET-1 whether it has an autocrine effect to the keratinocyte or not. Primary keratinocytes cultures from neonatal foreskins were done in complete MCDB 153 medium. Author performed
immunohistochemical
staining and Western blotting using keratin(K)14, K1, 10 and involucrin as a marker to confirm the effect of keratinocyte differentiation.
@ES The results were as follows:
@EN 1. Cell numbers of keratinocytes in culture medium without treatment of ET-1 were 6.17±0.38×10E4, 8.92±0.29×10E4, 10.42±1.51×10E4 after 4th, 6th, 8th days, respectively. Cell numbers of keratinocytes in culture medium with treatment of
ET-1(10
nM) were 6.75±0.25×10E4, 9.92±1.26×10E4, 14.08±1.13×10E4 after 4th, 6th, 8th, days, respectively. Compared with the control, the numbers of keratinocytes were increased statistically significant in the ET-1 treated group at 8 days(P<0.05).
2. In the immunohistochemical study using monoclonal antibodies(mAb) to K1, 10 and involucrin, cells of Ca++(0.5 mM)+ET-1(10 nM) treated group were stained weaker than those of Ca++(0.5 mM) treated group. In the study using mAb to K14, cells of
Ca++(0.5mM)+ET-1(10 nM) treated group were positively stained. However, cells of Ca++(0.5mM) treated group were not stained.
3. In the Western blotting study using mAb to involucrin, cells of Ca++(0.5 mM) treated group showed more intense reactivity than those of Ca++(0.5 mM)+ET-1(10 nM) treated group. However, K14 band expression was more intense in cells of Ca++(0.5
mM)+ET-1(10 nM) treated group than those of Ca++(0.5mM) treated group.
The above results strongly suggest that ET-1 may be synthesized and secreted from kerationocytes and ET-1 may have a specific role to proliferate and suppress differentiation of the keratinocytes in the human skin. In conclusion, it is believed
that the
ET-1 has autocrine effects to the keratinocytes themselves.
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