甲状腺素和葡萄糖对鸡前脂肪细胞增殖和THRSPα基因表达的影响

在培养基中添加葡萄糖和甲状腺素(T3),观察鸡前脂肪细胞的生长及分化后的增殖情况及检测THRSPα基因在不同时间段的表达情况。结果表明,葡萄糖和甲状腺素(T3)的使用没有显著促进脂肪细胞数量的增长,各试验组在前3 d细胞数量保持一定幅度的增长,但低于对照组,第4天数量降幅很大,除200 nmol/L T3外其他3组在第5天稍有回升,组间差异不显著(P>0.05)。添加50 nmol/L T3和200 nmol/L T3的2个试验组THRSPα基因相对表达量在第2天有较大幅度的增加且差异极显著(P<0.01);100 nmol/L T3在第6天稍有升高,前面5 d无显著变化。总之葡萄糖和甲状腺素(T3)细胞增殖和THRSPα基因表达未产生显著的影响。

Characterization of the Xenopus homolog of animmediate early gene associated with cell activation: sequence analysis and regulation of its expression by thyroid hormone during amphibian metamorphosis

The complex transformation of a tadpole to a frogduring amphibian development is under the control of thyroid hormone (T3). T3 is known to regulate gene transcription through its nuclear receptors. We have previouslyisolated many genes which are up-regulated by T3 in theintestine of Xenopus laevis tadpoles. We have now cloneda full- length cDNA for one such gene (IU12). Sequenceanalysis shows that the IU12 cDNA encodes a plasmamembrane protein with 12 transmembrane domains andhomologous to a mammalian gene associated with cell activation and organ development. Similarly, we have foundthat IU12 is activated during intestinal remodeling whenboth cell death and proliferation take place. Furthermore,IU12 is an early T3-response gene and its expression in theintestine during T3-induced metamorphosis mimics thatduring normal development. These results argue for a roleof IU12 in the signal transduction pathways leading to intestinal metamorphosis.