Evaluation of the rat thyroid cell strain FRTL-5 as an in-vitro bioassay system for thyrotrophin

1984 ◽  
Vol 101 (3) ◽  
pp. 269-NP ◽  
Author(s):  
S. P. Bidey ◽  
L. Chiovato ◽  
A. Day ◽  
M. Turmaine ◽  
R. P. Gould ◽  
...  

ABSTRACT The cyclic AMP response to bovine TSH was characterized in a strain of rat thyroid follicular cells (FRTL-5) maintained in continuous culture. Significant stimulation of intracellular cyclic AMP was attained at a TSH dose of 5 μu./ml. Cyclic AMP accumulation continued to increase, at higher TSH doses, with no evidence for attainment of a maximum level at the highest dose tested (5 mu./ml). The precision of TSH measurement was better than 10% over the range 50–5000 μu./ml, comparing favourably with that observed with analogous assays based on human cells, tissue slices or membrane preparations. Using sequential subcultures of FRTL-5 cells, the between-assay variation in response to a single dose of a standard preparation of bovine TSH (53/11; 370 μu./ml) was of the order of 20% which compared favourably with the between-assay variation observed with different cultures of human thyroid cells. Prolongation of the incubation of FRTL-5 cells with TSH to 3 h revealed a progressive increase in the extracellular accumulation of cyclic AMP. Addition of TSH to resting FRTL-5 cells resulted in a stimulation of inorganic iodide uptake with pronounced bell-shaped dose–response characteristics. Thus a maximum uptake was observed at a TSH dose of 100 μu./ml with a significant reduction at higher doses. Acute stimulation of cells with TSH (100 μu./ml) resulted in a rapid and marked alteration in cell morphology, with evidence of cellular retraction and surface ruffling. J. Endocr. (1984) 101, 269–276

1984 ◽  
Vol 106 (4) ◽  
pp. 482-489 ◽  
Author(s):  
S. P. Bidey ◽  
K. Ryder ◽  
R. Gaines-Das ◽  
N.J. Marshall ◽  
R. P. Ekins

Abstract. A clonal strain of thyrotrophin (TSH)-dependent rat thyroid cells (FRTL-5) has been used to evaluate the biological activity of reference preparations of both human and bovine TSH. Using the accumulation of intracellular cyclic AMP as a response parameter, the widely used bovine TSH preparation. Armour 'Thytropar', was calibrated against the First International Standard of Thyrotrophin (pituitary TSH), bovine, for immunoassay. Log dose – log response curves were parallel, and a relative potency of 2.4 IU/unit of 'Thytropar' was obtained. Subcultures of FRTL-5 cells were more responsive to both bovine and human TSH than were human thyroid follicular cells maintained as primary monolayer cultures. Dose-response curves for cyclic AMP accumulation were parallel for a single cell type differentially incubated with human TSH (the First International Reference Preparation) and bovine TSH (Armour 'Thytropar') preparations. The relative potencies (units: IU) of bovine-human TSH were of the order of 2.0 when tested on both FRTL-5 cultures and primary human thyroid monolayers. This suggests that in the spectrum of structural differences between TSH receptors of different species, the discriminatory powers of the human and FRTL-5 cell TSH receptor are similar. Thus FRTL-5 cells form the basis of a bioassay system of considerable value in the study of human thyroid stimulators, as we demonstrate in an evaluation of two recent preparations of human TSH.


Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1518
Author(s):  
Maria Qatato ◽  
Vaishnavi Venugopalan ◽  
Alaa Al-Hashimi ◽  
Maren Rehders ◽  
Aaron D. Valentine ◽  
...  

Trace amine-associated receptor 1 (rodent Taar1/human TAAR1) is a G protein-coupled receptor that is mainly recognized for its functions in neuromodulation. Previous in vitro studies suggested that Taar1 may signal from intracellular compartments. However, we have shown Taar1 to localize apically and on ciliary extensions in rodent thyrocytes, suggesting that at least in the thyroid, Taar1 may signal from the cilia at the apical plasma membrane domain of thyrocytes in situ, where it is exposed to the content of the follicle lumen containing putative Taar1 ligands. This study was designed to explore mouse Taar1 (mTaar1) trafficking, heterologously expressed in human and rat thyroid cell lines in order to establish an in vitro system in which Taar1 signaling from the cell surface can be studied in future. The results showed that chimeric mTaar1-EGFP traffics to the apical cell surface and localizes particularly to spherical structures of polarized thyroid cells, procilia, and primary cilia upon serum-starvation. Moreover, mTaar1-EGFP appears to form high molecular mass forms, possibly homodimers and tetramers, in stably expressing human thyroid cell lines. However, only monomeric mTaar1-EGFP was cell surface biotinylated in polarized human thyrocytes. In polarized rat thyrocytes, mTaar1-EGFP is retained in the endoplasmic reticulum, while cilia were reached by mTaar1-EGFP transiently co-expressed in combination with an HA-tagged construct of the related mTaar5. We conclude that Taar1 trafficking to cilia depends on their integrity. The results further suggest that an in vitro cell model was established that recapitulates Taar1 trafficking in thyrocytes in situ, in principle, and will enable studying Taar1 signaling in future, thus extending our general understanding of its potential significance for thyroid autoregulation.


2008 ◽  
Vol 198 (2) ◽  
pp. 301-307 ◽  
Author(s):  
Ling Jin ◽  
Vanessa Chico-Galdo ◽  
Claude Massart ◽  
Christine Gervy ◽  
Viviane De Maertelaere ◽  
...  

Chronic administration of acrylamide has been shown to induce thyroid tumors in rat. In vitro acrylamide also causes DNA damage, as demonstrated by the comet assay, in various types of cells including human thyroid cells and lymphocytes, as well as rat thyroid cell lines. In this work, mice were administered acrylamide in their drinking water in doses comparable with those used in rats, i.e., around 3–4 mg/kg per day for mice treated 2, 6, and 8 months. Some of the mice were also treated with thyroxine (T4) to depress the activity of the thyroid. Others were treated with methimazole that inhibits thyroid hormone synthesis and consequently secretion and thus induces TSH secretion and thyroid activation. These moderate treatments were shown to have their known effect on the thyroid (e.g. thyroid hormone and thyrotropin serum levels, thyroid gland morphology…). Besides, T4 induced an important polydipsia and degenerative hypertrophy of adrenal medulla. Acrylamide exerted various discrete effects and at high doses caused peripheral neuropathy, as demonstrated by hind-leg paralysis. However, it did not induce thyroid tumorigenesis. These results show that the thyroid tumorigenic effects of acrylamide are not observed in another rodent species, the mouse, and suggest the necessity of an epidemiological study in human to conclude on a public health policy.


1977 ◽  
Vol 72 (1) ◽  
pp. 87-96 ◽  
Author(s):  
S. P. BIDEY ◽  
P. MARSDEN ◽  
J. ANDERSON ◽  
C. G. McKERRON ◽  
H. BERRY

SUMMARY Follicular cells isolated from normal human thyroid tissue have been cultured for up to 140 h with bovine thyrotrophin (TSH) or dibutyryl cyclic AMP (DBcAMP). Both compounds induced marked reorganization of the cells into three-dimensional follicular structures, whilst non-supplemented cells assumed a monolayer form. Cultures treated initially with TSH or DBcAMP showed a greater iodide uptake capacity, in comparison with unsupplemented cultures, in which iodide uptake was markedly diminished after 24 h. The release of tri-iodothyronine (T3) and thyroxine (T4) into the medium was determined by radioimmunoassay. Both TSH- and DBcAMP-treated cells showed a significant increase in iodothyronine output compared with unsupplemented control cells. In contrast to the 'classical' TSH-induced depression of the T4:T3 ratio in vivo, an increase in the ratio was observed for both TSH- and DBcAMP-supplemented cells in vitro. The ratio was also significantly greater after TSH than after DBcAMP, and possible implications of this finding are discussed.


Author(s):  
F. Coperchini ◽  
L. Croce ◽  
P. Pignatti ◽  
G. Ricci ◽  
D. Gangemi ◽  
...  

Abstract Purpose Per- and poly-fluoroalkyl-substances (PFASs) are synthetic compounds that raised concern due to their potential adverse effects on human health. Long-chain PFAS were banned by government rules in many states, and thus, new emerging PFAS were recently introduced as substitutes. Among these, Perfluoro{acetic acid, 2-[(5-methoxy-1,3-dioxolan-4-yl)oxy]}, ammonium salt (C6O4) was recently introduced to produce a range of food contact articles and literature data about this compound are scanty. The aim of this study was to evaluate the in vitro effects of exposure to C6O4, compared with PFOA and PFOS on thyroid cells. Methods FRTL5 rat-thyroid cell lines and normal human thyroid cells (NHT) were incubated with increasing concentrations of C6O4 for 24, 48, 72, and 144 h to assess cell viability by WST-1. Cell viability was confirmed by AnnexinV/PI staining. Long-chain PFAS (PFOA and PFOS) were used at same concentrations as positive controls. The proliferation of cells exposed to C6O4, PFOA, and PFOS was measured by staining with crystal violet and evaluation of optical density after incubation with SDS. Changes in ROS production by FRTL5 and NHT after exposure to C6O4 at short (10, 20, and 30 min) and long-time points (24 h) were evaluated by cytofluorimetry. Results C6O4 exposure did not modify FRTL5 and NHT cell viability at any concentration and/or time points with no induction of necrosis/apoptosis. At difference, PFOS exposure reduced cell viability of FRTL5 while and NHT, while PFOA only in FRTL5. FRTL5 and NHT cell proliferation was reduced by incubation with by PFOA and PFOS, but not with C6O4. ROS production by NHT and FRTL5 cells was not modified after C6O4 exposure, at any time/concentration tested. Conclusions The present in vitro study constitutes the first evaluation of the potential adverse effects of the new emerging PFAS C6O4 in cultured rat and human thyroid cells, suggesting its safety for thyroid cells in vitro.


1981 ◽  
Vol 98 (3) ◽  
pp. 370-376 ◽  
Author(s):  
Stephen P. Bidey ◽  
Nicholas J. Marshall ◽  
Roger P. Ekins

Abstract. The cyclic AMP response to thyrotrophin (TSH) has been investigated in cells prepared from human thyroid tissue obtained during surgery for sub-total laryngectomy, and maintained under in vitro conditions as primary monolayer cultures. When cells were incubated with 1.0 mU TSH/ml, a maximal level of intracellular cyclic AMP was reached after 20 min of incubation in the presence of 0.5 mm 3-isobutyl-1-methyl xanthine (MIX). This level of cyclic AMP was sustained for at least 2 h. Half-maximal stimulation of cyclic AMP was produced by TSH doses of between 1 and 5 mU/ml. In a study of a series of eight groups of monolayer cultures, each derived from a single, different thyroid gland, the mean stimulation of cyclic AMP given by 50 mU TSH/ml was 37.8-fold greater than in non-stimulated cell monolayers. Significant stimulation to 50 μU TSH/ml was observed in some monolayers and the precision of measurement of TSH was better than 15% over the TSH dose range 0.2–1.0 mU/ml. The magnitude of the cyclic AMP response to TSH was unaffected by the presence in the incubation medium of 20% (v/v) normal human serum. A cyclic AMP response to TSH was still demonstrable in cells that had been maintained for a period of 22 days in monolayer culture, although the response was reduced in comparison with that given by 4–5 day old cultures.


1988 ◽  
Vol 118 (2) ◽  
pp. 199-203 ◽  
Author(s):  
J. Ginsberg ◽  
P. G. Murray

ABSTRACT The ability of the non-phorbol protein kinase C (PKC) activator 12-hydroxy-daphnetoxin (mezerein) to modulate differentiated thyroid function was examined in vitro. A dose-dependent inhibition of TSH-stimulated iodide organification was observed in porcine thyroid cells exposed to mezerein. Under identical conditions mezerein caused the translocation of PKC from its inactive cytosolic form to an active membrane-bound form in thyroid cell extracts. The relative biological potencies of mezerein and the phorbol ester, 12-0-tetradecanoylphorbol-13-acetate (TPA), to inhibit thyroid function in vitro corresponded to their abilities to activate PKC. This effect was also observed when dibutyryl cyclic AMP was used, implying a post-receptor site of action. To provide further evidence for this concept, the effects of mezerein and TPA on receptor-related events were studied. Neither mezerein nor TPA had any effect on the binding of radiolabelled TSH to solubilized porcine thyroid membranes. However, both mezerein and TPA were capable of stimulating cyclic AMP (cAMP) production in porcine thyroid cells in the basal state but could not augment TSH or forskolin-activated cAMP release. These data provide evidence that activation of PKC plays a role in the regulation of differentiated thyroid function in vitro and suggest that the effects of PKC are complex, with independent actions on cAMP accumulation and post-receptor events. J. Endocr. (1988) 118, 199–203


1999 ◽  
pp. 94-103 ◽  
Author(s):  
T Kimura ◽  
JE Dumont ◽  
A Fusco ◽  
J Golstein

In the rat thyroid cell lines PC Cl3, FRTL- 5 and WRT, proliferation is mainly regulated by insulin or IGF, and TSH. However, the mechanism regulating cell mass doubling prior to division is still unknown. Our laboratory has shown that in dog thyroid cells insulin promotes growth in size while TSH in the presence of insulin triggers DNA replication. In the absence of insulin, TSH has no effect on cell growth. In this report we investigated insulin action on both cell mass and DNA synthesis and its modulation by TSH and insulin in PC Cl3 and FRTL-5 cells. In PC Cl3 cells, insulin activated not only DNA synthesis but also protein synthesis and accumulation. Although TSH potentiated the stimulation of DNA synthesis induced by insulin, enhancement of protein synthesis by both agents was additive. All TSH effects were reproduced by forskolin. Similar effects were also obtained in FRTL-5 cells. This suggests that insulin and TSH, via cAMP, modulate both growth in size and DNA replication in these cell lines. Lovastatin, which blocks 3-hydroxy-3-methylglutaryl coenzyme A reductase, decreased the induction of DNA synthesis, but not of protein synthesis induced by insulin or TSH in PC Cl3 cells. In FRTL-5 cells, lovastatin reduced protein and DNA synthesis stimulated by insulin but not TSH-induced protein synthesis. Taking these data together, we propose that insulin and/or TSH both modulate cell mass doubling and DNA synthesis in these cell lines, presumably via different pathways, and that there are at least two pathways which regulate growth in size in FRTL-5 thyroid cells: one triggered by insulin, which is lovastatin sensitive, and the other activated by TSH, which is not sensitive to lovastatin.


1990 ◽  
Vol 122 (4) ◽  
pp. 520-526 ◽  
Author(s):  
Å. Krogh Rasmussen ◽  
L. Kayser ◽  
K. Bech ◽  
U. Feldt-Rasmussen ◽  
H. Perrild ◽  
...  

Abstract The effects of human recombinant interleukin 1α (20 pg/1-2 μg/l) and 1β (200 pg/1-20 μg/l) on two systems of thyroid cells have been compared. The thyroglobulin and cAMP secretion and the DNA content of human thyroid cells cultured in monolayer and of continuously grown rat thyroid cells, Fischer rat thyroid cell line have been studied. The growth of the rat thyroid cell line was inhibited by interleukin 1β (20 ng/1-20 μg/l), but not by interleukin 1α. None of the cytokines changed the cAMP production of the rat thyroid cells. In contrast, both cAMP production and thyroglobulin secretion were inhibited dose-dependently by the cytokines in human thyroid cells in secondary cultures. These results caution the interpretation and extrapolation of changes induced by interleukin 1 from one cell system to the other.


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