Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università degli Studi di Napoli, Via Vivaldi 43, 81100 Caserta, Italy Dipartimento di Scienze e Tecnologie, Università degli Studi del Sannio, Via Port'Arsa 11, 82100 Benevento, Italy.
J Endocrinol. 2014 Apr 22;221(2):R1-12. doi: 10.1530/JOE-13-0573. Print 2014 May.
Thyroid hormones (THs) are produced by the thyroid gland and converted in peripheral organs by deiodinases. THs regulate cell functions through two distinct mechanisms: genomic (nuclear) and nongenomic (non-nuclear). Many TH effects are mediated by the genomic pathway--a mechanism that requires TH activation of nuclear thyroid hormone receptors. The overall nongenomic processes, emerging as important accessory mechanisms in TH actions, have been observed at the plasma membrane, in the cytoplasm and cytoskeleton, and in organelles. Some products of peripheral TH metabolism (besides triiodo-L-thyronine), now termed 'nonclassical THs', were previously considered as inactive breakdown products. However, several reports have recently shown that they may have relevant biological effects. The recent accumulation of knowledge on how classical and nonclassical THs modulate the activity of membrane receptors, components of the mitochondrial respiratory chain, kinases and deacetylases, opened the door to the discovery of new pathways through which they act. We reviewed the current state-of-the-art on the actions of the nonclassical THs, discussing the role that these endogenous TH metabolites may have in the modulation of thyroid-related effects in organisms with differing complexity, ranging from nonmammals to humans.
甲状腺激素 (THs) 由甲状腺产生，并在周围器官中被脱碘酶转化。TH 通过两种不同的机制调节细胞功能：基因组（核）和非基因组（非核）。许多 TH 效应是通过基因组途径介导的——一种需要 TH 激活核甲状腺激素受体的机制。整体非基因组过程，作为 TH 作用的重要辅助机制出现，已经在质膜、细胞质和细胞骨架以及细胞器中观察到。外周 TH 代谢的一些产物（除三碘-L-甲状腺素外），现在被称为“非经典 THs”，以前被认为是无活性的分解产物。然而，最近有几项报告表明，它们可能具有相关的生物学效应。最近关于经典和非经典 TH 如何调节膜受体、线粒体呼吸链成分、激酶和脱乙酰酶活性的知识积累，为发现它们作用的新途径打开了大门。我们回顾了非经典 THs 作用的最新研究现状，讨论了这些内源性 TH 代谢物在调节从非哺乳动物到人类等不同复杂程度的生物体中与甲状腺相关的效应方面可能发挥的作用。
