The Mysterious Universe of the TSH Receptor

Abstract

The thyroid-stimulating hormone receptor (TSH-R) is predominantly expressed in the basolateral membrane of thyrocytes, where it stimulates almost every aspect of their metabolism. Several extrathyroidal locations of the receptor have been found including: the pituitary, the hypothalamus, and other areas of the central nervous system; the periorbital tissue; the skin; the kidney; the adrenal; the liver; the immune system cells; blood cells and vascular tissues; the adipose tissue; the cardiac and skeletal muscles, and the bone. Although the functionality of the receptor has been demonstrated in most of these tissues, its physiological importance is still a matter of debate. A contribution to several pathological processes is evident in some cases, as is the case of Grave’s disease in its multiple presentations. Conversely, in the context of other thyroid abnormalities, the contribution of the TSH-R and its ligand is still a matter of debate. This article reviews the several different sites of expression of the TSH-R and its potential role in both physiological and pathological processes.

Uric Acid Metabolic Disorders in Pituitary-Target Gland Axis

“…26 With the discovery of TSH receptor expression on the kidney, the mechanism of TSH affecting UA metabolism remains to be explored. 27…”

“… 26 With the discovery of TSH receptor expression on the kidney, the mechanism of TSH affecting UA metabolism remains to be explored. 27

Figure 3 The effect of pituitary-target gland hormones on XO and UA transporters. Various endocrine hormones affect UA production and excretion.

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The Usefulness of Thyroid Antibodies in the Diagnostic Approach to Autoimmune Thyroid Disease

“…TSHR is encoded by a gene located at chromosome 14q31 and belongs to the family of G-protein-coupled receptors. It has a large extracellular domain (containing an N-terminal domain, a leucine-rich repeat domain, and a hinge region or cleavage domain), seven transmembrane passageways, and a small intracellular domain [ 25 , 26 ]).…”

Deciphering the roles of triiodothyronine (T3) and thyroid-stimulating hormone (TSH) on cardiac electrical remodeling in clinical and experimental hypothyroidism

“…Obviously, for this to be true, the TSH receptor must be expressed in cardiac muscle. In the last decades, TSH receptor expression has been described in several extrathyroidal tissues such as skin, kidney, liver, bone, blood vessels, or the immune system, although its physiological relevance is difficult to establish and is still a matter of debate [ 62 ]. In the heart, the TSH receptor was first described in mouse atria and human cardiac muscle in 1995 [ 14 ].…”