COMMITMENT TO DIFFERENTIATION AND EXPRESSION OF EARLY DIFFERENTIATION MARKERS IN MURINE KERATINOCYTES IN-VITRO ARE REGULATED INDEPENDENTLY OF EXTRACELLULAR CALCIUM CONCENTRATIONS
COMMITMENT TO DIFFERENTIATION AND EXPRESSION OF EARLY DIFFERENTIATION MARKERS IN MURINE KERATINOCYTES IN-VITRO ARE REGULATED INDEPENDENTLY OF EXTRACELLULAR CALCIUM CONCENTRATIONS
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DOI：
10.1083/jcb.123.4.909
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发表时间：
1993-11-01
影响因子：
7.8
通讯作者：
PLEDGER, WJ
中科院分区：
文献类型：
--
作者：
DROZDOFF, V;PLEDGER, WJ
在表皮中，角质形成细胞分化中最早的特征性事件之一是协调诱导一对角蛋白，角蛋白1（K1）和角蛋白10（K10）特异性表达于基底上细胞。在体内和体外，细胞外钙是必要的几个生化和结构变化角质形成细胞分化过程中。然而，它一直不清楚，如果钙作为角质形成细胞的分化信号。在这些研究中，基底上角蛋白的mRNA和蛋白质的表达被用来测试是否在体外的初始分化的原代小鼠角质形成细胞依赖于细胞外钙的浓度的变化。K1的mRNA表达在低水平的培养物中的角质形成细胞生长在塑料在0.05 mM的钙，但在附着的细胞没有进一步诱导细胞外钙的浓度增加。角质形成细胞悬浮到半固体培养基中诱导K1 mRNA的表达和表达基底上角蛋白的细胞百分比的快速和大幅增加。的诱导是不受半固体培养基中的钙浓度，并不能通过将附着的细胞悬浮前暴露于更高的钙来增强。角质形成细胞暴露于EGF或纤连蛋白可抑制K1 mRNA的诱导。这些结果表明，承诺的小鼠角质形成细胞的终末分化是独立的细胞外钙，并可能主要是由细胞外因子以外的钙调节。
In the epidermis, one of the earliest characterized events in keratinocyte differentiation is the coordinate induction of a pair of keratins specifically expressed in suprabasal cells, keratin 1 (K1) and keratin 10 (K10). Both in vivo and in vitro, extracellular calcium is necessary for several biochemical and structural changes during keratinocyte differentiation. However, it has been unclear if calcium serves as a differentiation signal in keratinocytes. In these studies, expression of suprabasal keratin mRNA and protein is used to test whether the initial differentiation of primary mouse keratinocytes in vitro is dependent on changes in the concentration of extracellular calcium.K1 mRNA was expressed at low levels in cultures of keratinocytes growing on plastic in 0.05 mM calcium but in attached cells was not further induced by increases in the concentration of extracellular calcium. Suspension of the keratinocytes into semi-solid medium induced a rapid and substantial increase in both expression of K1 mRNA and in the percentage of cells expressing suprabasal keratin proteins. The induction was unaffected by the concentration of calcium in the semi-solid medium and could not be enhanced by exposing attached cells to higher calcium before suspension. The induction of K1 mRNA could be inhibited by exposure of the keratinocytes to either EGF or fibronectin. These results suggest that commitment of mouse keratinocytes to terminal differentiation is independent of extracellular calcium and may be regulated primarily by extracellular factors other than calcium.