Hübner G, Werner S
Max-Planck-Institut für Biochemie, Martinsried, Germany.
Exp Cell Res. 1996 Oct 10;228(1):106-13. doi: 10.1006/excr.1996.0305.
Recently we demonstrated a large induction of activin expression in fibroblasts and keratinocytes after cutaneous injury in mice. To identify possible mediators of activin induction during skin repair, we have now analyzed the regulation of this factor in cultured keratinocytes and fibroblasts. Here we show that activin A mRNA and protein levels are low in quiescent keratinocytes and fibroblasts but expression is strongly induced upon serum treatment. The stimulatory effect of serum on activin expression is likely to be a combinatorial effect of different growth factors, since platelet-poor plasma serum and several purified serum growth factors also stimulated activin expression, although to a lesser extent than complete serum. Furthermore, we found increased expression of activin in keratinocytes and fibroblasts after addition of the proinflammatory cytokines interleukin 1beta and tumor necrosis factor alpha. Taken together, our data suggest that serum growth factors which are released upon hemorrhage as well as proinflammatory cytokines derived from neutrophils and macrophages might be responsible for induction of activin expression after injury.
最近我们证明，在小鼠皮肤损伤后，成纤维细胞和角质形成细胞中激活素的表达大量增加。为了确定皮肤修复过程中激活素诱导的可能介质，我们现在分析了这种因子在培养的角质形成细胞和成纤维细胞中的调控情况。在这里我们表明，在静止的角质形成细胞和成纤维细胞中，激活素A的mRNA和蛋白质水平较低，但血清处理后表达会强烈诱导。血清对激活素表达的刺激作用可能是不同生长因子的组合效应，因为血小板贫乏血浆血清和几种纯化的血清生长因子也能刺激激活素表达，尽管程度比完全血清小。此外，我们发现添加促炎细胞因子白细胞介素1β和肿瘤坏死因子α后，角质形成细胞和成纤维细胞中激活素的表达增加。综上所述，我们的数据表明，出血时释放的血清生长因子以及源自中性粒细胞和巨噬细胞的促炎细胞因子可能是损伤后激活素表达诱导的原因。
