Auto-Regulation of the Thyroid Gland Beyond Classical Pathways
Exp Clin Endocrinol Diabetes DOI: 10.1055/a-1080-2969This mini-review asks how self-regulation of the thyroid gland is realized at
the cellular and molecular levels by canonical and non-canonical means.
Canonical pathways of thyroid regulation comprise thyroid stimulating
hormone-triggered receptor signaling. As part of non-canonical regulation,
we hypothesized an interplay between protease-mediated thyroglobulin
processing and thyroid hormone release into the circulation by means of
thyroid hormone transporters like Mct8. We proposed a sensing mechanism by
different thyroid hormone transporters, present in specific subcellular
locations of thyroid epithelial cells, selectively monitoring individual
steps of thyroglobulin processing, and thus, the cellular thyroid hormone
status. Indeed, we found that proteases and thyroid hormone transporters are
functionally inter-connected, however, in a counter-intuitive manner
fostering self-thyrotoxicity in particular in Mct8- and/or
Mct10-deficient mice. Furthermore, the possible role of the G
protein-coupled receptor Taar1 is discussed, because we detected Taar1 at
cilia of the apical plasma membrane of thyrocytes in vitro and in
situ. Eventually, through pheno-typing Taar1-deficient mice, we
identified a co-regulatory role of Taar1 and the thyroid stimulating hormone
receptors. Recently, we showed that inhibition of thyroglobulin-processing
enzymes results in disappearance of cilia from the apical pole of
thyrocytes, while Taar1 is r...
Source: Experimental and Clinical Endocrinology and Diabetes - Category: Endocrinology Authors: Brix, Klaudia Szumska, Joanna Weber, Jonas Qatato, Maria Venugopalan, Vaishnavi Al-Hashimi, Alaa Rehders, Maren Tags: Mini-Review Source Type: research