Abstract：
Sulfonation is an important step in the metabolism of dopamine, estrogens, dehydroepiandrosterone, as well as thyroid hormones. However, the regulation of cytosolic sulfotransferases in the thyroid is not well understood. In a DNA microarray analysis of rat thyroid FRTL-5 cells, we found that the mRNA expression of 10 of 48 sulfotransferases was significantly altered by thyroid stimulating hormone (TSH), with that of sulfotransferase family 1A member 1 (SULT1A1) being the most significantly affected. Real-time PCR and Western blot analyses revealed that TSH, forskolin and dibutyryl cyclic AMP significantly suppressed SULT1A1 mRNA and protein levels in a time- and concentration-dependent manner. Moreover, immunofluorescence staining of FRTL-5 cells showed that SULT1A1 is localized in the perinuclear area in the absence of TSH but is spread throughout the cytoplasm with reduced fluorescence intensity in the presence of TSH. Sulfotransferase activity in FRTL-5 cells, measured using 3\'-phosphoadenosine-5\'-phosphosulfate as a donner and p-nitrophenol as an acceptor substrate, was significantly reduced by TSH. These findings suggest that the expression and activity of SULT1A1 are modulated by TSH in thyrocytes.
摘要：
磺化是多巴胺代谢的重要步骤,雌激素,脱氢表雄酮，以及甲状腺激素。然而,甲状腺中胞质磺基转移酶的调节尚不清楚。在大鼠甲状腺FRTL-5细胞的DNA微阵列分析中，我们发现48种磺基转移酶中有10种的mRNA表达被促甲状腺激素(TSH)显著改变,其中磺基转移酶家族1A成员1（SULT1A1）受到的影响最大。实时PCR和蛋白质印迹分析显示，TSH，毛喉素和二丁酰基环AMP以时间和浓度依赖性方式显着抑制SULT1A1mRNA和蛋白质水平。此外，FRTL-5细胞的免疫荧光染色显示，在没有TSH的情况下，SULT1A1位于核周区域，但在存在TSH的情况下，以降低的荧光强度散布在整个细胞质中。FRTL-5细胞中的硫基转移酶活性，使用3'-磷酸腺苷-5'-磷酸硫酸盐作为受体底物和对硝基苯酚作为受体底物进行测量，TSH显著降低。这些发现表明，甲状腺细胞中TSH调节SULT1A1的表达和活性。
