대피지
2001년 39권 2호 161 ~ 167
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 nerv ous 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. |
