Korean J Dermatol.  2001 Feb;39(2):161-167.

The Effect of Nerve Growth Factor on Cell Proliferation and Expression of Its Receptors in Cultured Human Keratinocytes

• Ryou JH
• Lim TW
• Park JK
• Kim NI

Abstract

BACKGROUND: Nerve growth factor(NGF) is a neurotrophic polypeptide necessary for the survival and growth of some central neurons, as well as sensory afferent and sympathetic neurons. In addition to its actions on the nervous system, it also has a significant biologic effects on cells of the immune-inflammatory compartment. Recent studies suggest that NGF is an important autocrine growth factor and survival factor for keratinocytes which express both high- and low-affinity receptors for NGF.
OBJECTIVE
The purpose of this study is to detect NFG receptors on cultured human keratinocytes and to evaluate the effect of NGF on proliferation of cultured human keratinocytes.
METHODS
Cultured human keratinocytes were examined for the expression of high affinity receptor TrkA and low affinity receptor p75 by Northern blot, Western blot and immunocytochemistry. The effects of NGF on proliferation of cultured human keratinocytes were also evaluated. To specify the NGF effect on proliferation of human keratinocytes, excess of anti-NGF neutralizing polyclonal antibody was added.
RESULTS
1) NGF significantly stimulated the proliferation of keratinocytes in both 1% of keratinocyte growth supplement(KGS)-added medium(100ng/ml) and 0.2% KGS-added media(50, 100, 500ng/ml), (p<0.05). The cell number was dose-dependently increased in 0.2% KGS-added media. 2) Whenever we added 500 ng/ml of anti-NGF polyclonal antibody to the growth media, the cell number was statistically higher in 100ng/ml NGF-added group of 1% KGS-added medium, but there was not any statistical significance in 0.2% KGS-added media group. 3) Immunocytochemical staining with specific antibodies to TrkA and p75 revealed positive findings for these receptors, but TrkB and TrkC were not detected. 4) We could not detect both the mRNA and protein of TrkA and p75 by Northern and Western blot methods.
CONCLUSION
These results suggest that both high affinity- and low affinity receptors for NGF are expressed in cultured human keratinocytes and NGF can induce keratinocyte proliferation.

Keyword

Nerve growth factor; Keratinocyte

MeSH Terms

Antibodies
Blotting, Northern
Blotting, Western
Cell Count
Cell Proliferation*
Humans*
Immunohistochemistry
Keratinocytes*
Nerve Growth Factor*
Nervous System
Neurons
RNA, Messenger
Antibodies
Nerve Growth Factor
RNA, Messenger