Arsenate suppression of human keratinocyte programming
Arsenate suppression of human keratinocyte programming
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DOI：
10.1016/s1383-5742(97)00015-x
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发表时间：
1997-06-01
影响因子：
5.3
通讯作者：
Rice, RH
中科院分区：
文献类型：
--
作者：
Kachinskas, DJ;Qin, Q;Rice, RH
人角化细胞系SCC-9已被用作砷酸盐诱导的分化扰动模型。这些细胞在10 μ M砷酸盐中生长，使培养物达到融合，但通过Northern blotting检测，阻止了6种基底上分化标记物的表达（天花素、氯霉素、聚丝蛋白、spr 1、角蛋白1和角蛋白10）。相比之下，一种分化标记物（角质细胞转谷氨酰胺酶）和角蛋白5、角蛋白14、AP2或甘油醛磷酸脱氢酶的mRNA水平仅发生轻微变化。过渡金属氧离子钒酸盐和铬酸盐对这些标记物的抑制作用与砷酸盐基本相同，而醋酸十四烷酰磷的慢性抑制分化效果一般较差。为了确定先前观察到的砷酸盐介导的AP1和AP2活性的改变是否可以解释天花子蛋白的抑制，进行了启动子分析。推测的AP1和AP2应答元件在5'侧DNA转录活性的重要区域被确定。两个AP1位点和一个AP2位点的突变显著降低了启动子活性，并将其降低到约为天然序列所赋予的10%。这些结果支持了一种假说，即砷酸盐通过改变转录因子AP1和AP2来抑制天花素的表达，更一般地说，抑制角质形成细胞的编程。
The human keratinocyte line SCC-9 has been used as a model for arsenate-induced perturbations of differentiation. Growth of these cells in 10 mu M arsenate permitted the cultures to reach confluence, but prevented expression of 6 markers of suprabasal differentiation (involucrin, loricrin, filaggrin, spr 1, keratin 1 and keratin 10) as assayed by Northern blotting. By contrast, only slight alterations in mRNA levels were observed for one differentiation marker (keratinocyte transglutami- nase) and for keratin 5, keratin 14, AP2 or glyceraldehyde phosphate dehydrogenase. The transition metal oxyanions vanadate and chromate had essentially the same suppressive effect on these markers as arsenate, while chronic treatment with tetradecanoylphorbol acetate was generally less effective in suppressing differentiation. To determine whether the previously observed arsenate-mediated alteration in AP1 and AP2 activities could account for the suppression of involucrin, a promoter analysis was conducted. Putative AP1 and AP2 response elements were identified in regions important for transcriptional activity of the 5'-flanking DNA. Mutations in two AP1 sites and one AP2 site were observed to decrease promoter activity significantly, and in combination, to reduce it to approximate to 10% of that conferred by the native sequence. These results lend support to the working hypothesis that arsenate suppresses involucrin expression, and, more generally, keratinocyte programming, by altering the transcription factors AP1 and AP2.