scholarly journals Low Doses of Methylmercury Induce the Proliferation of Thyroid Cells In Vitro Through Modulation of ERK Pathway

2020 ◽  
Vol 21 (5) ◽  
pp. 1556 ◽  
Author(s):  
Valentina Maggisano ◽  
Stefania Bulotta ◽  
Marilena Celano ◽  
Jessica Maiuolo ◽  
Saverio Massimo Lepore ◽  
...  
Keyword(s):  
Cell Viability ◽  
Prolonged Exposure ◽  
Signal Transduction Pathway ◽  
Immunoblot Analysis ◽  
Thyroid Cell ◽  
Promoting Effect ◽  
Thyroid Cells ◽  
M Phase ◽  
High Concentrations

Exposure to environmental endocrine disruptors has been associated with an increased frequency of thyroid pathology. In this study, we evaluated the effects of various concentrations of methylmercury (MeHg) on immortalized, non-tumorigenic thyroid cells (Nthy-ori-3-1). Exposure to MeHg at 2.5 and 5 µM for 24 h caused a reduction in cell viability with a decrease of the cell population in sub-G0 phase, as detected by MTT and flow cytometry. Conversely, MeHg at the lower concentration of 0.1 µM increased the cell viability with a rise of G2/M phase. An immunoblot analysis showed higher expression levels of phospho-ERK and not of phospho-Akt. Further enhancement of the cell growth rate was observed after a prolonged exposure of the cells up to 18 days to MeHg 0.1 µM. The present findings demonstrate the toxicity of high concentrations of MeHg on thyroid cells, while showing that treatment with lower doses of Hg, as may occur after prolonged exposure to this environmental contaminant, exerts a promoting effect on thyroid cell proliferation, by acting on the ERK-mediated pro-oncogenic signal transduction pathway.

scholarly journals The new generation PFAS C6O4 does not produce adverse effects on thyroid cells in vitro

2020 ◽  
Author(s):  
F. Coperchini ◽  
L. Croce ◽  
P. Pignatti ◽  
G. Ricci ◽  
D. Gangemi ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Cell Viability ◽  
Human Thyroid ◽  
Thyroid Cell ◽  
Ros Production ◽  
Thyroid Cells ◽  
Time Points ◽  
Rat Thyroid ◽  
Long Chain

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.

Methods of experimental polyploidization and their use in apple breeding

2020 ◽  
Vol 62 ◽  
pp. 85-90
Author(s):  
L. V. Tashmatova ◽  
O. V. Matsneva ◽  
T. M. Khromova ◽  
V. V. Shakhov
Keyword(s):  
Exposure Time ◽  
Cell Walls ◽  
Prolonged Exposure ◽  
Ornamental Plants ◽  
Colchicine Treatment ◽  
Apple Trees ◽  
Open Ground ◽  
High Concentrations ◽  
Diploid Gametes

The article presents methods of experimental polyploidy of fruit, berry and ornamental plants. The purpose of this review is to highlight the problems and prospects of polyploidization of plants in the open ground and in vitro culture and the possibility of their application for apple trees. For the purpose of obtaining apple tetraploids as donors of diploid gametes, seed seedlings were treated with a solution of colchicine in concentrations of 0.1-0.4 % for 24 and 48 hours. Colchicine concentrations of 0.3 % and 0.4 % at 48 hours of treatment had a detrimental eff ect on their development. As a result, tetraploids and chimeras were obtained from seeds from free pollination of the varieties Orlik, Svezhest, Kandil Orlovsky, as well as from seeds obtained from crossing the varieties Svezhest×Bolotovskoe, Moskovskoe Оzherel’e×Imrus, Girlyanda×Venyaminovskoe. The optimal concentration of colchicine was 0.1 %. Methods of colchicine treatment have been studied: 1) adding to the nutrient medium, colchicine concentration: 0.01%, 0.02%, exposure time 24h-19 days; 2) applying amitotic solution to the growth point, colchicine concentration: 0.1 %, 0.2 %, exposure time 24h-7 days. To increase the penetration of colchicine through the cell walls, a 0.1 % dimexide solution was used. Studies have shown that high concentrations and prolonged exposure to colchicine reduce the viability of explants.

The Effects of Butyric Acid on the Differentiation, Proliferation, Apoptosis, and Autophagy of IPEC-J2 Cells

2020 ◽  
Vol 20 (4) ◽  
pp. 307-317
Author(s):  
Yuan Yang ◽  
Jin Huang ◽  
Jianzhong Li ◽  
Huansheng Yang ◽  
Yulong Yin
Keyword(s):  
Cell Viability ◽  
P38 Mapk ◽  
Butyric Acid ◽  
Cell Apoptosis ◽  
Mapk Pathway ◽  
Mrna Level ◽  
Dependent Manner ◽  
M Phase ◽  
High Concentrations ◽  
Underlying Mechanisms

Background: Butyric acid (BT), a short-chain fatty acid, is the preferred colonocyte energy source. The effects of BT on the differentiation, proliferation, and apoptosis of small intestinal epithelial cells of piglets and its underlying mechanisms have not been fully elucidated. Methods: In this study, it was found that 0.2-0.4 mM BT promoted the differentiation of procine jejunal epithelial (IPEC-J2) cells. BT at 0.5 mM or higher concentrations significantly impaired cell viability in a dose- and time-dependent manner. In addition, BT at high concentrations inhibited the IPEC-J2 cell proliferation and induced cell cycle arrest in the G2/M phase. Results: Our results demonstrated that BT triggered IPEC-J2 cell apoptosis via the caspase8-caspase3 pathway accompanied by excess reactive oxygen species (ROS) and TNF-α production. BT at high concentrations inhibited cell autophagy associated with increased lysosome formation. It was found that BT-reduced IPEC-J2 cell viability could be attenuated by p38 MAPK inhibitor SB202190. Moreover, SB202190 attenuated BT-increased p38 MAPK target DDIT3 mRNA level and V-ATPase mRNA level that were responsible for normal acidic lysosomes. Conclusion: In conclusion, 1) at 0.2-0.4 mM, BT promotes the differentiation of IPEC-J2 cells; 2) BT at 0.5 mM or higher concentrations induces cell apoptosis via the p38 MAPK pathway; 3) BT inhibits cells autophagy and promotes lysosome formation at high concentrations.

scholarly journals Trace Amine-Associated Receptor 1 Trafficking to Cilia of Thyroid Epithelial Cells

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1518
Author(s):  
Maria Qatato ◽  
Vaishnavi Venugopalan ◽  
Alaa Al-Hashimi ◽  
Maren Rehders ◽  
Aaron D. Valentine ◽  
...  
Keyword(s):  
Cell Surface ◽  
Cell Lines ◽  
Human Thyroid ◽  
Apical Plasma Membrane ◽  
Thyroid Cell ◽  
Thyroid Cells ◽  
Trace Amine ◽  
Rat Thyroid

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.

scholarly journals Acrylamide does not induce tumorigenesis or major defects in mice in vivo

2008 ◽  
Vol 198 (2) ◽  
pp. 301-307 ◽  
Author(s):  
Ling Jin ◽  
Vanessa Chico-Galdo ◽  
Claude Massart ◽  
Christine Gervy ◽  
Viviane De Maertelaere ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Chronic Administration ◽  
Serum Levels ◽  
Human Thyroid ◽  
Thyroid Cell ◽  
Thyroid Cells ◽  
Hormone Synthesis ◽  
Rat Thyroid

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.

Effects of protein kinase C activators on the in-vitro action of thyrotrophin in pigs

1988 ◽  
Vol 118 (2) ◽  
pp. 199-203 ◽  
Author(s):  
J. Ginsberg ◽  
P. G. Murray
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Thyroid Function ◽  
Receptor Site ◽  
Thyroid Cell ◽  
Thyroid Cells ◽  
Cell Extracts ◽  
Kinase C

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

Modulation of Platelet Activation In Vitro by Thrombopoietin

1995 ◽  
Vol 74 (06) ◽  
pp. 1541-1545 ◽  
Author(s):  
Hiroshi Kojima ◽  
Yoko Hamazaki ◽  
Yuka Nagata ◽  
Kazuo Todokoro ◽  
Toshiro Nagasawa ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Tyrosine Phosphorylation ◽  
Platelet Activation ◽  
Signal Transduction Pathway ◽  
Immunoblot Analysis ◽  
Transduction Pathway ◽  
Intracellular Signal Transduction Pathway ◽  
Granule Secretion ◽  
Induced Aggregation

SummaryEffect of human recombinant thrombopoietin (TPO) on platelet activation in vitro was studied. Although TPO by itself did not cause platelet aggregation, it upregulated ADP-induced aggregation, especially the second wave of aggregation. This effect was dose-dependent for up to 5 ng/ml of TPO. When platelets were activated by epinephrine, collagen, or α-thrombin, similar effect was observed. However, TPO did not affect A23187- or PMA-induced aggregation, suggesting that TPO may have modulated the signal transduction pathway upstream of inositol 1,4,5-trisphosphate and diacylglycerol production. TPO also upregulated thrombin-induced α-granule secretion. To clarify the involvement of protein tyrosine phosphorylation, platelets were activated by TPO and/or suboptimal concentration of ADP, then tyrosine phosphorylation was detected by immunoblot analysis, using anti-phosphotyrosine monoclonal antibody. TPO by itself caused significant tyrosine phosphorylation of 146,130,122,108, 97,94, and 88 kDa proteins. Further, by using antibodies against signal transduction molecules for immunoprecipitation, we observed the significant tyrosine phosphorylation in Jak2 and Tyk2 molecules after TPO-stimulation. The results of the present experiment clearly indicate that TPO directly activated platelets and modulated intracellular signal transduction pathway.

scholarly journals The Flavonoid Quercetin Induces AP-1 Activation in FRTL-5 Thyroid Cells

Antioxidants ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 112 ◽  
Author(s):  
Cesidio Giuliani
Keyword(s):  
Binding Site ◽  
Thyroid Function ◽  
Thyroid Cell ◽  
Consensus Binding Site ◽  
Thyroid Cells ◽  
Basal Activity ◽  
Reporter Vector ◽  
Rat Thyroid

Previous studies have shown that quercetin inhibits thyroid function both in vitro and in vivo. An attempt to evaluate the effect of quercetin at the promoter level of the thyroid-specific genes led to the observation that this compound induces the basal activity of the reporter vector. Therefore, the action of quercetin has been evaluated on the basal activity of several reporter vectors: The PGL3 basic, promoter and control vectors from Promega, and a pSV-based chloramphenicol acetyltransferase (CAT) reporter vector. In the Fisher Rat Thyroid cell Line FRTL-5 thyroid cells transiently transfected, quercetin 10 μM increased the basal activity of all the reporter vectors evaluated, although the degree of the effect was significantly different among them. The analysis of the difference among the regulatory regions of these vectors identified the activator protein 1 (AP-1) binding site as one of the potential sites involved in the quercetin effect. Electromobility shift assay experiments showed that the treatment with quercetin induced the binding of a protein complex to an oligonucleotide containing the AP-1 consensus binding site. This is the first study showing an effect of quercetin on AP-1 activity in thyroid cells. Further studies are in progress to understand the role of AP-1 activation in the effects of quercetin on thyroid function.

scholarly journals Reevaluation of the Effect of Iodine on Thyroid Cell Survival and Function Using PCCL3 and Nthy-ori 3-1 Cells

2020 ◽  
Vol 4 (11) ◽  
Author(s):  
Tomomi Kurashige ◽  
Mika Shimamura ◽  
Yuji Nagayama
Keyword(s):  
Normal Function ◽  
Iodine Uptake ◽  
Thyroid Cell ◽  
Dependent Manner ◽  
Messenger Rnas ◽  
Thyroid Cells ◽  
Excess Iodine ◽  
Wide Range ◽  
And Function

Abstract The appropriate amount of iodine is critical for normal function of thyroid cells synthesizing thyroid hormones. Although normal thyroid cell lines such as rat PCCL3 and FRTL5 and human Nthy-ori 3-1 have been widely used for in vitro studies on physiological and pathophysiological effects of iodine on thyroid cells, we have recently pointed out the critical differences between FRTL5/PCCL3 cells and Nthy-ori 3-1 cells. Therefore, we here directly compared some of the cellular characteristics—iodine uptake, differentiated status, iodine-induced cytotoxicity, and iodine-regulation of autophagy—between PCCL3 and Nthy-ori 3-1 cells. PCCL3 cells express messenger RNAs for thyrotropin receptor and sodium/iodine symporter and incorporate iodine in a thyrotropin-dependent manner, whereas Nthy-ori 3-1 cells do not either. Nevertheless, both cells were comparably resistant to iodine cytotoxicity: Only far excess iodine (5 × 10–2 M) killed 20% to 40% cells in 24 hours with perchlorate exhibiting no effect, suggesting this cytotoxic effect is due to extracellular iodine. In contrast, a wide range of iodine (5 × 10–9 to 5 × 10–2 M) induced autophagy in PCCL3 cells, which was abolished by perchlorate, indicating intracellular iodine-induction of autophagy, but this effect was not observed in Nthy-ori 3-1 cells. In conclusion, it is critical to discriminate the effect of iodine incorporated into cells from that of extracellular iodine on thyroid cells. Iodine-uptake competent thyroid cells such as PCCL3 and FRTL5 cells, not Nthy-ori 3-1 cells, should be used for studies on iodine effect on thyroid cells.

STUDIES ON HYALINE MEMBRANES

PEDIATRICS ◽  
1961 ◽  
Vol 27 (4) ◽  
pp. 567-577
Author(s):  
Natalie Aronson
Keyword(s):  
Prolonged Exposure ◽  
Proteolytic Enzymes ◽  
Mouse Lung ◽  
Thioglycollic Acid ◽  
Hyaline Membranes ◽  
Human Lungs ◽  
High Concentrations ◽  
Dissolution In Vitro ◽  
Do So

Pulmonary hyaline membranes were studied by observations on their dissolution in vitro by proteolytic enzymes, by streptokinase and by urea with and without added thioglycollic acid. Pepsin, trypsin and chymotrypsin dissolved the hyaline membranes both in sections of human lungs as well as in sections of mouse lung with the experimentally produced disease, whereas streptokinase, alone, failed to do so. The combination of 8 molar urea with 2% thioglycollic acid partially removed the hyaline membranes from lung slices. These findings are consistent with the view that fibrin is an important component of pulmonary hyaline membranes. Four possible therapeutic agents were evaluated in the experimental disease in mice, produced by prolonged exposure to high concentrations of oxygen. Chymotrypsin, trypsin and chloropromazine did not influence the mortality rate or incidence of pulmonary lesions. Heparin treatment led to a striking increase in mortality and to an increased incidence of pulmonary hyaline membranes.

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