Instituto de Neurobiología, Departamento de Neurobiología Celular y Molecular, Universidad Nacional Autónoma de México (UNAM), Boulevard Juriquilla 3001, Querétaro, Qro.76230, Mexico.
Instituto de Neurobiología, Departamento de Neurobiología Celular y Molecular, Universidad Nacional Autónoma de México (UNAM), Boulevard Juriquilla 3001, Querétaro, Qro.76230, Mexico.
Mol Cell Endocrinol. 2017 Dec 25;459:59-63. doi: 10.1016/j.mce.2017.03.003. Epub 2017 Mar 4.
Thyroid hormones, or THs, are well-known regulators of a wide range of biological processes that occur throughout the lifespan of all vertebrates. THs act through genomic mechanisms mediated by thyroid hormone receptors (TRs). The main product of the thyroid gland is thyroxine or T4, which can be further transformed by different biochemical pathways to produce at least 15 active or inactive molecules. T3, a product of T4 outer-ring deiodination, has been recognized as the main bioactive TH. However, growing evidence has shown that other TH derivatives are able to bind to, and/or activate TRs, to induce thyromimetic effects. The compiled data in this review points to at least two of these TR alternative ligands: TRIAC and T2. Taking this into account, non-mammalian models have proven to be advantageous to explore new TH derivatives with potential novel actions, prompting a re-evaluation of the role and mechanism of action of TR alternative ligands that were previously believed to be inactive. The functional implications of these ligands across different vertebrates may require us to reconsider current established notions of thyroid physiology.
甲状腺激素（THs）是众所周知的调节因子，能够调节所有脊椎动物生命周期中发生的广泛的生物学过程。THs 通过甲状腺激素受体（TRs）介导的基因组机制发挥作用。甲状腺的主要产物是甲状腺素或 T4，它可以通过不同的生化途径进一步转化为至少 15 种活性或非活性分子。T3 是 T4 外环脱碘的产物，被认为是主要的生物活性 TH。然而，越来越多的证据表明，其他 TH 衍生物能够与 TR 结合并/或激活 TR，从而诱导甲状腺刺激作用。本综述中汇编的数据至少指向了两种 TR 替代配体：TRIAC 和 T2。考虑到这一点，非哺乳动物模型已被证明有利于探索具有潜在新作用的新 TH 衍生物，促使人们重新评估先前被认为无活性的 TR 替代配体的作用和作用机制。这些配体在不同脊椎动物中的功能意义可能需要我们重新考虑当前已建立的甲状腺生理学概念。
