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Induction of interleukin (IL)‐1α and β gene expression in human keratinocytes exposed to repetitive strain: Their role in strain‐induced keratinocyte proliferation and morphological change
Author(s) -
Takei Teiji,
Kito Hiroyuki,
Du Wei,
Mills Ira,
Sumpio Bauer E.
Publication year - 1998
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/(sici)1097-4644(19980501)69:2<95::aid-jcb1>3.0.co;2-p
Subject(s) - keratinocyte , autocrine signalling , microbiology and biotechnology , strain (injury) , biology , gene expression , interleukin , alpha (finance) , cell culture , in vitro , cytokine , immunology , gene , biochemistry , anatomy , medicine , genetics , construct validity , nursing , patient satisfaction
Recent studies in our laboratory have demonstrated that mechanical strain alters many facets of keratinocyte biology including proliferation, protein synthesis, and morphology. IL‐1 is known to play an important role in the autocrine regulation of these basic cellular properties under basal and stimulated conditions. However, it is not known whether IL‐1 plays a role in strain‐induced alteration of keratinocyte biology. Thus, the objective of this study was to test the hypothesis that cyclic strain stimulates IL‐1 expression and that strain‐induced changes in keratinocyte function is regulated by IL‐1. To test this hypothesis, we examined the effect of cyclic strain (10% average deformation) on keratinocyte IL‐1 gene expression and the effect of neutralizing antibodies of IL‐1α and IL‐1β on strain‐induced changes in keratinocyte proliferation, morphology, and orientation. Northern blot analyses demonstrated that steady state levels of IL‐1α and β mRNA were elevated by 4 h, peaked at 12 h of cyclic strain (IL‐1α, 304 ± 14.2%; IL‐1β, 212 ± 5.6% increase vs. static controls) and decreased gradually by 24 h. IL‐1 antibodies (IL‐1α, 0.01 μg/ml; IL‐1β, 0.01 μg/ml) significantly blocked strain‐induced keratinocyte proliferation as well as the basal rate of proliferation. In contrast, IL‐1 antibodies (IL‐1α, 0.01 μg/ml; IL‐1β, 0.1 μg/ml) had no effect on strain‐induced morphological changes such as elongation and alignment. We conclude that mechanical strain induces IL‐1 mRNA expression in keratinocytes. The role of IL‐1 in mediating strain‐induced changes in keratinocyte biology remains to be determined but appears to be independent of morphological changes. J. Cell. Biochem. 69:95–103, 1998. © 1998 Wiley‐Liss, Inc.