Project description:Analysis of third instar eye-antennal Drosophila imaginal discs with forced expression of hth, tsh or hth+tsh in the eye using an eye-specific GAL4 driver (optix2.3-GAL4). Forced maintenance of hth+tsh expression (but not of any of the two alone) results in overgrowth and aberrant cell differentiation. Results provide insight into new targets of hth+tsh.
Project description:Analysis of third instar eye-antennal Drosophila imaginal discs with forced expression of hth, tsh or hth+tsh in the eye using an eye-specific GAL4 driver (optix2.3-GAL4). Forced maintenance of hth+tsh expression (but not of any of the two alone) results in overgrowth and aberrant cell differentiation. Results provide insight into new targets of hth+tsh.
Project description:Deficiency in Krüppel-like zinc finger transcription factor, GLI-Similar 3 (GLIS3) in humans is associated with the development of congenital hypothyroidism. However, the functions of GLIS3 in the thyroid gland and by what mechanism GLIS3-dysfunction causes hypothyroidism are unknown. In this study, we demonstrate that GLIS3 acts downstream of thyroid stimulating hormone (TSH)/TSHR and is indispensable for TSH/TSHR-mediated induction of thyroid follicular cell proliferation and thyroid hormone biosynthesis. ChIP-Seq and promoter analysis revealed that GLIS3 is critical for the transcriptional activation of several genes required for thyroid hormone biosynthesis, including the iodide transporters Nis and Pds, indicating that these genes are directly regulated by GLIS3. The repression of cell proliferation regulatory genes is due to the inhibition of TSH-mediated activation of the mTORC1/RPS6 pathway as well as direct transcriptional regulation of several cell division-related genes by GLIS3. Consequently, GLIS3-deficiency prevents the development of goiter as well as the induction of inflammatory and fibrotic genes during chronic elevation of circulating TSH. Our study identifies GLIS3 as a new and key regulator of TSH/TSHR-mediated thyroid hormone biosynthesis and proliferation of thyroid follicular cells, and uncovers a mechanism by which GLIS3-deficiency causes congenital hypothyroidism and prevents goiter development.
Project description:Activation of thyroid stimulating hormone receptor (TSHR) fundamentally leads to hyperthyroidism. To elucidate TSHR signaling, we conducted transcriptome analyses for hyperthyroid mice that we generated by overexpressing TSH. TSH overexpression drastically changed their thyroid transcriptome. In particular, enrichment analyses identified the cell cycle, phosphatidylinositol-3 kinase/Akt pathway, and Ras-related protein 1 pathway as possibly associated with goiter development. Regarding hyperthyroidism, Slc26a4 was exclusively upregulated with TSH overexpression among genes crucial to thyroid hormone secretion. To verify its significance, we overexpressed TSH in Slc26a4 knockout mice. TSH overexpression caused hyperthyroidism in Slc26a4 knockout mice, equivalent to that in control mice. Thus, we did not observe significant changes in known genes and pathways involved in thyroid hormone secretion with TSH overexpression. Our datasets might include candidate genes that have not yet been identified as regulators of thyroid function. Our transcriptome datasets regarding hyperthyroidism can contribute to future research on TSHR signaling.
Project description:This study sought to identify the profile of circulating miRNAs and its response to human recombinant TSH in thyroid cancer patients with recurrent disease
Project description:Thyroid hormone receptor beta (THRB) is post-translationally modified by small ubiquitin-like modifier (SUMO). To investigate the biological role of THRB sumoylation, we generated a mouse model with a mutation that disrupts sumoylation at lysine 146 (K146Q). The THRB K146Q mutant mice had normal serum thyroxine (T4), markedly elevated serum thyrotropin (TSH) (81-fold above control), and enlargement of both the pituitary and the thyroid gland. The marked elevation in TSH, despite a normal serum T4 concentration, indicated blunted feedback regulation of TSH. TH profuction was 10-fold lower (per mg of thyroid tissue) in mutant mice compared to Wt mice.
Project description:A time-course analysis of TSH-stimulation in two rat thyroid cell lines (FRTL5 and FRT/TSHR) was performed. The expression levels of 8,784 transcripts were measured at three different time points, i.e. before (0), 30 minutes (30m) and 17 hours (17h) after TSH stimulation, by means of Affymetrix RG-U34A arrays. Keywords: Time course
