Thyrotropin receptor (TSHR) and insulin-like growth factor 1 receptor (IGF-1R) have been shown to crosstalk in primary cultures of human thyrocytes (hThyros) and Graves' orbital fibroblasts. The phenomenon of TSHR/IGF-1R crosstalk has been largely studied in the pathogenesis of thyroid eye disease (TED) in human orbital fibroblasts. Here, we investigated the effects of inhibiting the IGF-1R-mediated contribution to crosstalk by linsitinib (Lins), a small-molecule IGF-1R kinase inhibitor, on TSH-induced regulation of thyroperoxidase (TPO) and thyroglobulin (TG) mRNAs and proteins in hThyros and on TPO and TG mRNAs and free thyroxine (fT4) levels in mice.
View Article and Find Full Text PDFIn ataxia disorders, motor incoordination (ataxia) is primarily linked to the dysfunction and degeneration of cerebellar Purkinje cells (PCs). In spinocerebellar ataxia 6 (SCA6), for example, decreased BDNF-TrkB signalling appears to contribute to PC dysfunction and ataxia. However, abnormal BDNF-TrkB signalling in granule cells (GCs) may contribute to PC dysfunction and incoordination in ataxia disorders, as TrkB receptors are also present in GCs that provide extensive input to PCs.
View Article and Find Full Text PDFContext: Thyroid-stimulating hormone (or thyrotropin) receptor (TSHR) could be a selective target for small molecule ligands to treat thyroid cancer (TC).
Objective: We report a novel, orally efficacious ligand for TSHR that exhibits proliferation inhibitory activity against human TC in vitro and in vivo, and inhibition of metastasis in vivo.
Methods: A35 (NCATS-SM4420; NCGC00241808) was selected from a sublibrary of >200 TSHR ligands.
Regulation of thyroid cells by thyrotropin (TSH) and epidermal growth factor (EGF) has been known but different effects of these regulators on proliferation and differentiation have been reported. We studied these responses in primary cultures of human thyroid cells to determine whether TSH receptor (TSHR) signaling may involve EGF receptor (EGFR) transactivation. We confirm that EGF stimulates proliferation and de-differentiation whereas TSH causes differentiation in the absence of other growth factors.
View Article and Find Full Text PDFPurpose: To study the changes in subfoveal choroidal thickness in children with progressive myopia who have been wearing bifocal soft contact lenses (BSCL) with an ADD power of +4.0 D for 3 months.
Material And Methods: The study included 40 patients (80 eyes) with progressive myopia of low and moderate degrees.
The TSH receptor (TSHR) is the major regulator of thyroid hormone biosynthesis in human thyrocytes by regulating the transcription of a number of genes including thyroglobulin (TG) and thyroperoxidase (TPO). Until recently, it was thought that TSHR initiated signal transduction pathways only at the cell-surface and that internalization was primarily involved in TSHR desensitization and downregulation. Studies primarily in mouse cells showed that TSHR internalization regulates gene transcription at an intracellular site also.
View Article and Find Full Text PDFWe compared the effects of the first-, second- and third-generation antihistamines in different doses on enzyme activity and cytokine production by macrophages and their death using an in vitro model. It was found that decreasing the dose led to an increase in the number of viable cells; after contact with second-generation antihistamines (loratadine, desloratadine), apoptosis of macrophages predominated. A dose-dependent increase in activity of ATPase and 5'-AMP with less pronounced effect of second-generation drugs was revealed.
View Article and Find Full Text PDFThe article describes a clinical case of bilateral occlusion of retinal vessels in a patient with Waldenstrom's disease - a rare lymphoplasmocytic tumor of the bone marrow characterized by a complex of syndromes, among which the syndrome of blood hyperviscosity dominates. Comprehensive clinical, instrumental and laboratory examinations revealed that besides the syndrome of blood hyperviscosity the patient also had loci of cerebral ischemia (according to magnetic resonance imaging), ocular hypoperfusion with severe deficiency of retinal and choroidal blood flow (according to Doppler methods) indicating the presence of ocular ischemic syndrome. Since bilateral occlusion of retinal vessels without concomitant vascular and/or systemic pathology is rare, patients with such diagnosis should be referred to a hematologist.
View Article and Find Full Text PDFThe thyrotropin (TSH) receptor (TSHR) signals via G proteins of all four classes and -arrestin 1. Stimulation of TSHR leads to increasing cAMP production that has been reported as a monotonic dose-response curve that plateaus at high TSH doses. In HEK 293 cells overexpressing TSHRs (HEK-TSHR cells), we found that TSHR activation exhibits an "inverted U-shaped dose-response curve" with increasing cAMP production at low doses of TSH and decreased cAMP production at high doses (>1 mU/ml).
View Article and Find Full Text PDFRecently, we showed that TSH-enhanced differentiation of a human preosteoblast-like cell model involved a -arrestin 1 (-Arr 1)-mediated pathway. To study this pathway in more detail, we sought to discover a small molecule ligand that was functionally selective toward human TSH receptor (TSHR) activation of -Arr 1. High-throughput screening using a cell line stably expressing mutated TSHRs and mutated -Arr 1 (DiscoverX1 cells) led to the discovery of agonists that stimulated translocation of -Arr 1 to the TSHR, but did not activate G-mediated signaling pathways, i.
View Article and Find Full Text PDFAn original model of nephrogenic hypertension in rats was used for histochemical mapping of NADPH diaphorase (NO synthase) in various renal segments to examine the effect of hypotensive drugs furosemide, bendazol, and clonidine on the time course of nitroxide production in the kidneys. In various nephron segments, these drugs modulated NO synthesis in different ways. Clonidine induced a stable up-regulation of NO synthesis, which can maintain active vasodilation and gradually diminish the rennin production.
View Article and Find Full Text PDFFront Endocrinol (Lausanne)
August 2016
We are developing an orally available small-molecule, allosteric TSH receptor (TSHR) agonist for follow-up diagnostics of patients with thyroid cancer. The agonist C2 (NCGC00161870) that we have studied so far is a racemic mixture containing equal amounts of two enantiomers, E1 and E2. As enantiomers of many drugs exhibit different pharmacologic properties, we assessed the properties of E1 and E2.
View Article and Find Full Text PDFThe results of the systemic antimicrobials (AM) consumption and expenditures assessment in the departments of surgery of multi-profile hospitals in different regions of the Russian Federation and the Republic of Belarus in 2009-2010 based on retrospective collection and analysis of the data from the hospital expenditure notes using ATC/DDD methodology are presented. The average AM consumption and expenditure rates in the above mentioned departments varied from 24.9 DDD/100 bed-days to 61.
View Article and Find Full Text PDFLimited evidence has associated lower ventilation rates (VRs) in schools with reduced student learning or achievement. We analyzed longitudinal data collected over two school years from 150 classrooms in 28 schools within three California school districts. We estimated daily classroom VRs from real-time indoor carbon dioxide measured by web-connected sensors.
View Article and Find Full Text PDFThis research assesses benefits of adding to California Title-24 ventilation rate (VR) standards a performance-based option, similar to the American Society of Heating, Refrigerating, and Air Conditioning Engineers 'Indoor Air Quality Procedure' (IAQP) for retail spaces. Ventilation rates and concentrations of contaminants of concern (CoC) were measured in 13 stores. Mass balance models were used to estimate 'IAQP-based' VRs that would maintain concentrations of all CoCs below health- or odor-based reference concentration limits.
View Article and Find Full Text PDFThyrotropin (TSH) activation of the TSH receptor (TSHR), a 7-transmembrane-spanning receptor (7TMR), may have osteoprotective properties by direct effects on bone. TSHR activation by TSH phosphorylates protein kinases AKT1, p38α, and ERK1/2 in some cells. We found TSH-induced phosphorylation of these kinases in 2 cell lines engineered to express TSHRs, human embryonic kidney HEK-TSHR cells and human osteoblastic U2OS-TSHR cells.
View Article and Find Full Text PDFBecause the TSH receptor (TSHR) plays an important role in the pathogenesis of thyroid disease, a TSHR antagonist could be a novel treatment. We attempted to develop a small molecule, drug-like antagonist of TSHR signaling that is selective and active in vivo. We synthesized NCGC00242364 (ANTAG3) by chemical modification of a previously reported TSHR antagonist.
View Article and Find Full Text PDFLimited evidence associates inadequate classroom ventilation rates (VRs) with increased illness absence (IA). We investigated relationships between VRs and IA in California elementary schools over two school years in 162 3rd-5th-grade classrooms in 28 schools in three school districts: South Coast (SC), Bay Area (BA), and Central Valley (CV). We estimated relationships between daily IA and VR (estimated from two year daily real-time carbon dioxide in each classroom) in zero-inflated negative binomial models.
View Article and Find Full Text PDFWe herein describe the rapid synthesis of a diverse set of dihydroquinazolin-4-ones and quinazolin-4-ones, their biological evaluation as thyroid stimulating hormone receptor (TSHR) agonists, and SAR analysis. Among the compounds screened, 8b was 60-fold more potent than the hit compound 1a, which was identified from a high throughput screen of over 73,000 compounds.
View Article and Find Full Text PDFResults of fundus autofluorescence imaging using confocal scanning laser ophthalmoscope HRA II ("Heidelberg Engeneering", Heidelberg, Germany) are presented. 106 patients with various retinal and optic nerve conditions were examined. The following conditions were diagnosed using autofluorescence imaging: early stage of age-related macular degeneration, macular hard and soft drusen, signs of retinitis pigmentosa, senile macular hole, central serous chorioretinopathy and optic disc drusen.
View Article and Find Full Text PDFContext: Graves' disease (GD) is caused by persistent, unregulated stimulation of thyrocytes by thyroid-stimulating antibodies (TSAbs) that activate the TSH receptor (TSHR). We previously reported the first small-molecule antagonist of human TSHR and showed that it inhibited receptor signaling stimulated by sera from four patients with GD.
Objective: Our objective was to develop a better TSHR antagonist and use it to determine whether inhibition of TSAb activation of TSHR is a general phenomenon.
Background: Dampness and mold have been shown in qualitative reviews to be associated with a variety of adverse respiratory health effects, including respiratory tract infections. Several published meta-analyses have provided quantitative summaries for some of these associations, but not for respiratory infections. Demonstrating a causal relationship between dampness-related agents, which are preventable exposures, and respiratory tract infections would suggest important new public health strategies.
View Article and Find Full Text PDFSmall molecule inverse agonists for the TSH receptor (TSHR) may be used as probes of the role of basal (or agonist-independent or constitutive) signaling and may have therapeutic potential as orally active drugs to inhibit basal signaling in patients with thyroid cancer and in some patients with hyperthyroidism. We describe the first small-molecule ligand [1;2-(3-((2,6-dimethylphenoxy)methyl)-4-methoxyphenyl)-3-(furan-2-ylmethyl)-2,3-dihydroquinazolin-4(1H)-one] that exhibits inverse agonist properties at TSHR. 1 inhibits basal and TSH-stimulated signaling, measured as cAMP production, by TSHRs in HEK-EM 293 cells stably expressing wild-type TSHRs; the antagonism of TSH-mediated signaling is competitive.
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