Insulin-like growth factor-1 enhances the expression of functional TSH receptor in orbital fibroblasts from thyroid-associated ophthalmopathy.

Insulin-like growth factor-1 enhances the expression of functional TSH receptor in orbital fibroblasts from thyroid-associated ophthalmopathy. Immunobiology. 2019 Dec 25;:151902 Authors: Paik JS, Kim SE, Kim JH, Lee JY, Yang SW, Lee SB Abstract Thyroid-associated ophthalmopathy (TAO), an autoimmune disease, occurs in approximately 50 % of patients with Graves' hyperthyroidism. Thyroid-stimulating hormone receptor (TSHR) that is expressed in orbital fibroblasts is the autoimmune target in the development of TAO. In addition to thyroid-stimulating immunoglobulin (TSI), insulin-like growth factor (IGF)-1 is also involved in the development of TAO. IGF-1 has been reported to potentiate the effects of thyroid-stimulating hormone (TSH) and TSI on TSHR signaling. In the current study, we investigated the effects of IGF-1 on the cell surface expression of the functional TSHR and its possible mechanism of action in human orbital fibroblasts. Our results show that orbital fibroblasts from the TAO patients expressed higher levels of IGF-1 receptor (IGF-R), compared to control subjects. Treatment with IGF-1 enhanced the expression of surface TSHR in orbital fibroblasts from TAO patients, but not from control subjects. In addition, treatment with IGF-1 increased the level of TSHR at both the protein and mRNA levels. Furthermore, pre-treatment with IGF-1 potentiated TSH-induced cAMP production, compared to cells that were treated with only TSH. Ou...
Source: Immunobiology - Category: Allergy & Immunology Authors: Tags: Immunobiology Source Type: research