Identification of GPR39 receptor and ghrelin receptor in thyroid tissues in paediatric patients with immune and non-immune thyroid diseases.

The preproghrelin gene is responsible for generating ghrelin and obestatin, two gastric peptides with opposite effects on food intake. Obestatin suppresses food intake and digestive motility through interaction with GPR39 (GPCR). Ghrelin is supposed to be a link connecting metabolism and energy homeostasis with growth as the result of activation of the growth hormone secretagogue receptor (GHSR). The aim of the current study was to assess the expression of preproghrelin, GPR39 and GHSR in thyroid tissues from patients with Graves' disease (GD; n = 15), non-toxic nodular goiter (NTNG; n = 10) and toxic nodular goiter (TNG; n = 10). GPR39 and GHSR in thyroid tissues were detected by immunohistochemistry and Western blot, revealing higher expression of both proteins in GD patients (+++; ++) in comparison with NTNG (+; +) and TNG (++; +) patients. GPR39 was present in thyroid autoimmune disease, NTNG and TNG at band p51 (kDa). The ghrelin receptor was identified in all study groups at p70. mRNA expression for preproghrelin was found in thyroid tissues from patients with immune and non-immune thyroid diseases. We conclude that the expression of the ghrelin receptor family in thyroid tissues may suggest a role of gastric peptides in thyroid functions. mRNA of preproghrelin expression is a proof of ghrelin gene-derived peptide presence in thyroid tissues. Copyright (c) 2013 S. Karger AG, Basel