2005年，美国疾病控制中心（Centers for Disease Control，CDC）公布的资料显示，美国现有糖尿病患者2080万，还有4100万人处于糖尿病前期（pre-diabetes）。中国的糖尿病患者及处于糖尿病前期的人数应该是美国的数倍。外源性补充胰岛...2005年，美国疾病控制中心（Centers for Disease Control，CDC）公布的资料显示，美国现有糖尿病患者2080万，还有4100万人处于糖尿病前期（pre-diabetes）。中国的糖尿病患者及处于糖尿病前期的人数应该是美国的数倍。外源性补充胰岛素是目前治疗糖尿病的主要措施。然而，外源性胰岛素的使用由于缺乏负反馈调节机制，不能对血糖进行精确调控，展开更多
Iodothyronine deiodinase catalyzes the initiation and termination of thyroid hormones(THs) effects, and plays a central role in the regulation of thyroid hormone level in vertebrates. In non-chordate invertebrates, on...Iodothyronine deiodinase catalyzes the initiation and termination of thyroid hormones(THs) effects, and plays a central role in the regulation of thyroid hormone level in vertebrates. In non-chordate invertebrates, only one deiodinase has been identified in the scallop C hlamys farreri. Here, two deiodinases were cloned in the Pacific oyster C rassostrea gigas( Cg Dx and C g Dy). The characteristic in-frame TGA codons and selenocysteine insertion sequence elements in the oyster deiodinase c DNAs supported the activity of them. Furthermore, seven orthologs of deiodinases were found by a tblastn search in the mollusk Lottia gigantea and the annelid C apitella teleta. A phylogenetic analysis revealed that the deiodinase gene originated from an common ancestor and a clade-specific gene duplication occurred independently during the differentiation of the mollusk, annelid, and vertebrate lineages. The distinct spatiotemporal expression patterns implied functional divergence of the two deiodinases. The expression of C g Dx and Cg Dy was influenced by L-thyroxine T4, and putative thyroid hormone responsive elements were found in their promoters, which suggested that the oyster deiodinases were feedback regulated by TH. Epinephrine stimulated the expression level of C g Dx and Cg Dy, suggesting an interaction effect between different hormones. This study provides the first evidence for the existence of a conserved TH feedback regulation mechanism in mollusks, providing insights into TH evolution.展开更多
文摘2005年，美国疾病控制中心（Centers for Disease Control，CDC）公布的资料显示，美国现有糖尿病患者2080万，还有4100万人处于糖尿病前期（pre-diabetes）。中国的糖尿病患者及处于糖尿病前期的人数应该是美国的数倍。外源性补充胰岛素是目前治疗糖尿病的主要措施。然而，外源性胰岛素的使用由于缺乏负反馈调节机制，不能对血糖进行精确调控，
基金Supported by the National Natural Science Foundation of China(Nos.31372515,31402285)the National Basic Research Program of China(973 Program)(No.2010CB126401)the National High Technology Research and Development Program(863 Program)(No.2012AA10A405)
文摘Iodothyronine deiodinase catalyzes the initiation and termination of thyroid hormones(THs) effects, and plays a central role in the regulation of thyroid hormone level in vertebrates. In non-chordate invertebrates, only one deiodinase has been identified in the scallop C hlamys farreri. Here, two deiodinases were cloned in the Pacific oyster C rassostrea gigas( Cg Dx and C g Dy). The characteristic in-frame TGA codons and selenocysteine insertion sequence elements in the oyster deiodinase c DNAs supported the activity of them. Furthermore, seven orthologs of deiodinases were found by a tblastn search in the mollusk Lottia gigantea and the annelid C apitella teleta. A phylogenetic analysis revealed that the deiodinase gene originated from an common ancestor and a clade-specific gene duplication occurred independently during the differentiation of the mollusk, annelid, and vertebrate lineages. The distinct spatiotemporal expression patterns implied functional divergence of the two deiodinases. The expression of C g Dx and Cg Dy was influenced by L-thyroxine T4, and putative thyroid hormone responsive elements were found in their promoters, which suggested that the oyster deiodinases were feedback regulated by TH. Epinephrine stimulated the expression level of C g Dx and Cg Dy, suggesting an interaction effect between different hormones. This study provides the first evidence for the existence of a conserved TH feedback regulation mechanism in mollusks, providing insights into TH evolution.
