Indirect regulation of human dehydroepiandrosterone sulfotransferase family 1A member 2 by thyroid hormones
Indirect regulation of human dehydroepiandrosterone sulfotransferase family 1A member 2 by thyroid hormones
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DOI：
10.1210/en.2005-1166
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发表时间：
2006-05-01
期刊：
影响因子：
4.8
通讯作者：
Lin, KH
中科院分区：
文献类型：
--
作者：
Huang, YH;Lee, CY;Lin, KH
甲状腺激素 T-3 调节细胞代谢、分化和发育。采用 cDNA 微阵列研究 T-3 处理过表达甲状腺激素受体 α (TR α) 的肝癌细胞系 (HepG2-TR α) 后靶基因调控的机制。差异表达的靶基因是几种代谢酶，包括脱氢表雄酮磺基转移酶家族1A成员2（SULT2A1）。在 HepG2-TR α 细胞中经过 48 小时 T-3 处理后，酶 SULT2A1 的蛋白质水平升高约 5 倍，mRNA 水平升高约 9 倍。放线菌酮抑制 T-3 诱导的 SULT2A1 表达，表明调节是间接的。据报道，SULT2A1 受人类肾上腺中两种转录因子类固醇生成因子 1 (SF1) 和 GATA 的调节。在 HepG2-TR α 细胞中，T-3 诱导 SF1 在蛋白质水平上升高 2.5 至 3.5 倍，在 RNA 水平上升高 6.2 倍。 SULT2A1 基因上存在大约七个 SF1 结合位点。为了鉴定和定位关键的 SF1 结合位点，构建了 pGL2 质粒中 SULT2A1 启动子片段的一系列缺失突变体。 T-3 使 SULT2A1 基因的启动子活性增强约 2.8 至 7.1 倍。 -228 SF1 结合位点被确定为最关键的位点，因为删除该区域会减少 T-3 诱导的表达。转录因子SF1的应用增强了-228但不增强-117报告质粒的活性。应用 T-3 后，甲状腺切除大鼠中 SULT2A1 和 SF1 的蛋白质和 RNA 水平上调。总之，这项工作证明 SULT2A1 基因由 SF1 介导并间接受 T-3 调控。需要进一步研究来阐明 T-3 介导的 SULT2A1 诱导的生理重要性。
Thyroid hormone, T-3, regulates cell metabolism, differentiation, and development. cDNA microarrays were performed to study the mechanism of target gene regulation after T-3 treatment in a thyroid hormone receptor-alpha (TR alpha)-overexpressing hepatoma cell line (HepG2-TR alpha). The differentially expressed target genes are several metabolic enzymes, including dehydroepiandrosterone-sulfotransferase family 1A member 2 (SULT2A1). Enzyme SULT2A1 was elevated roughly 5-fold at the protein level and 9-fold increase at the mRNA level after 48 h T-3 treatment in HepG2-TR alpha cells. Cycloheximide inhibited T-3-induced SULT2A1 expression, suggesting that regulation was indirect. SULT2A1 has been reported to be regulated by the two transcription factors, steroidogenic factor 1 (SF1) and GATA, in the human adrenal gland. T-3 induced a 2.5- to 3.5-fold elevation of SF1 at the protein level and a 6.2-fold increase at the RNA level in HepG2-TR alpha cells. About seven SF1 binding sites exist on the SULT2A1 gene. To identify and localize the critical SF1 binding site, series of deletion mutants of SULT2A1 promoter fragments in pGL2 plasmid were constructed. The promoter activity of the SULT2A1 gene was enhanced about 2.8- to 7.1-fold by T-3. The -228 SF1 binding site was identified as the most critical site because deleting this region reduced T-3-induced expression. Transcription factor SF1 application enhanced the -228 but not -117 reporter plasmid activities. SULT2A1 and SF1 up-regulation at protein and RNA levels in thyroidectomized rats occurred after T-3 application. In summary, this work demonstrated that the SULT2A1 gene was mediated by SF1 and indirectly regulated by T-3. Further study is required to elucidate the physiological importance of SULT2A1 induction mediated by T-3.