Modulation of the epidermal growth factor receptor of human keratinocytes by calcium ion.
Modulation of the epidermal growth factor receptor of human keratinocytes by calcium ion.
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钙离子对人角质细胞表皮生长因子受体的调节。
DOI：
10.1111/1523-1747.ep12518204
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
PayneJr,RE
中科院分区：
文献类型：
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作者：
O'Keefe,EJ;PayneJr,RE
已经发现，与在具有生理钙浓度（1-2 mM）的培养基中生长的细胞相比，在含有降低的钙浓度（0.07mM）的培养基中生长的人角质形成细胞显示改变的形态和降低的分化。由于这种改变可以通过生长因子介导，我们测量了[125 I]表皮生长因子（EGF）的结合。将新生角质形成细胞在没有饲养层的情况下传代培养，并在1.1 mM钙中生长至汇合。在结合测定之前，更换培养基并将细胞在钙减少的情况下孵育不同的时间段。结合数据的Scatchard图显示，在37°C下4-24 h后，受体数量增加5倍，亲和力无变化（3 × 10- 9 M）。最大结合发生在0.02-0.04 mM钙，并随着钙浓度的增加急剧下降。这种增加可以通过在结合开始增加后不久加入钙来防止，但在发生实质性升高后改变较少，尽管钙浓度降低时的形态学变化在几小时内逆转。检测到[125 I]生长调节素C和[125 I]伴刀豆球蛋白A的结合显著增加，但[125 I]pindalol（一种β受体配体）的结合几乎没有变化。角质形成细胞在减少钙浓度增加EGF减少表面EGF受体轻快地在时间和温度依赖性的方式。这些数据表明，角质形成细胞表现出增强的结合EGF和一些其他细胞表面配体的条件下，分化迟缓。
Human keratinocytes grown in medium containing reduced calcium concentrations (0.07 mM) have been found to show altered morphology and decreased differentiation in comparison with cells grown in medium with physiologic calcium concentrations (1–2 mM). Since such alterations could be mediated by growth factors, we measured binding of [125I]epidermal growth factor (EGF). Neonatal keratinocytes were subcultured without feeder layers and grown to confluence in 1.1 mM calcium. Medium was changed and cells incubated for various periods in reduced calcium prior to binding assays. Scatchard plots of binding data showed a 5-fold increase in receptor number with no change in affinity (3 × 10-9M) after 4–24 h at 37°C. Maximal binding occurred at 0.02–0.04 mM calcium and decreased sharply with increasing calcium concentrations. The increase could be prevented by calcium added soon after binding began to increase but was altered less after substantial elevation had occurred, although morphologic changes at reduced calcium concentrations were reversed within several hours. Substantial increases in binding of [125I]somatomedin C and [125I]concanavalin A were detected, but binding of [125I]pindalol, a beta-receptor ligand, was changed little. Keratinocytes at reduced calcium concentrations responded to added EGF by decreasing surface EGF receptors briskly in a time- and temperature-dependent fashion. The data suggest that keratinocytes show enhanced binding of EGF and some other cell surface ligands under conditions in which differentiation is retarded.