There are some evidences that an interleukin(IL)1αenhances murine as well as human keratinocyte proliferation in vitro. However, according to its results of experiments using IL-1αby several investigators, it is also conceivable that IL-1αdid
not
stimulate keratinocyte proliferation.
To determine whether keratinocyte proliferation by IL-1αis occurred, the present study was undertaken. In addition, we measured superoxide radical and superoxide dismutase to identify the intracellular biochemical events associated with effects
caused
by IL-1α. Primary keratinocyte cultures from neonatal foreskins were grown in complete MCDB 153 medium. Measurements of superoxide radical and superoxide dismutase (SOD) activity were performed according to Babior and fridovich methods,
respectively.
@ES The results as follows:
@EN 1. Cell numbers of keratinocytes without treatment of recombinant IL-1α(Ril-1α) were 6.67±0.91×10E4, 8.23±0.65×10E4, 1.09±0.12×10E5 at 4, 6 and 8 days, respectively. Cell numbers of keratinocytes with treatment of 10ng/㎖ rIL-1α were
6.20±0.92×10E4, 1.58±0.10×10E6 at 4, 6, and 8 days, respectively. Compared with that of untreated case, approximately 1.5 fold increase in cell numbers was observed after 8 days culture with treatment of 10ng/㎗rIL-1α.
2. Release of superoxide radical were measured after 30 minutes exposure to 0.1, 1.0, 10ng/㎖ Ril-1α, the results show 1.61±0.65nmol/1×10E5, 3.68±0.61nml/1×10E5 respectively. Significant superoxide radical release was detectable at 1ng/㎖
rIL-1α
compared with 0.68±0.19nmol/1×10E5 of untreated cases (P<0.05).
3. Total SOD activity without treatment of Ril-1α were 99.32±14.84, 115.25±14.32, 130.85±10.80 respectively, which suggested that Ril-1α induced increase of total SOD significantly (P<0.05). Ril-1αstimulate total SOD induction in a dose
and
time
dependent manner, although the effects was not outstanding. Mn SOD activity after treatment of 10ng/㎖ Ril-1α hours was 104.34±11.61, which was approximately 11 fold of that of untreated case. rIL-1α also induced the Cu, Zn SOD activity, but
the
effect was not so much as in the case of Mn SOD.]
In summary, the results indicate that rIL-1αenhances human keratinocyte proliferation and superoxide radical released by rIL-1αmay be play a role in human keratinocyte proliferation. Also production of total SOD, especially Mn SOD in response
to
rIL-1αinduced and scavenged overproduced superoxide radical which in turn may result in protection of keratinocytes.
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