The aim of the present study was to establish a cell model of volume-regulated anion channel subunit LRRC8A and investigate the physiological characteristics of LRRC8A. The eukaryotic expression vectors of LRRC8A and YFP-H148Q/I152L were constructed and transfected into Fischer rat thyroid (FRT) cells by Lipofectamine 2000. The FRT cell lines co-expressing LRRC8A and YFP-H148Q/I152L were obtained by antibiotic screening. The expression of LRRC8A and YFP-H148Q/I152L in FRT cells was detected by the inverted fluorescence microscope. The fluorescence quenching kinetic experiment was done to verify the function and effectiveness of the cell model. Then the cell model was utilized to study the physiological characteristics of LRRC8A, such as the characteristics of anion transport, the opening of LRRC8A by osmotic pressure, the effect of anion transport velocity, and the effect of chloride channel inhibitors on LRRC8A anion channel. The results of the inverted fluorescence microscope showed that LRRC8A was expressed on the cell membrane and YFP-H148Q/I152L was expressed in the cytoplasm. The results of fluorescence quenching kinetic test showed that under the condition of low osmotic state, LRRC8A could transport some kinds of anions, such as iodine and chloride ions. Osmotic pressure played a key role in the regulation of LRRC8A volume-regulated anion channel opening. Chloride channel inhibitors inhibited ion transport of LRRC8A channel in a dose-dependent manner. It is suggested that LRRC8A has the characteristics of classic volume-regulated anion channels by using the cell model of FRT cells co-expressing LRRC8A and YFP-H148Q/I152L.
Animals ; Anions ; Cells, Cultured ; Chloride Channels ; antagonists & inhibitors ; Ion Transport ; Membrane Proteins ; physiology ; Microscopy, Fluorescence ; Rats ; Rats, Inbred F344 ; Thyroid Gland ; cytology ; Transfection

To investigate the effect of serine/threonine-protein kinase B-Raf (BRAF)-activated long-chain non-coding RNA (lncRNA-BANCR) on apoptosis and autophagy in thyroid carcinoma cells and the underlying mechanisms.
 Methods: RT-PCR was used to detect the expression of lncRNA-BANCR in thyroid carcinoma and normal thyroid tissues. The association between lncRNA-BANCR and clinicopathological data was analyzed in patients with thyroid cancer. Cell counting kit-8 (CCK-8) was used to detect the effect of lncRNA-BANCR on the proliferation of thyroid cancer cells. The effect of lncRNA-BANCR on the apoptosis of thyroid carcinoma cells was detected by flow cytometry. Transwell invasion assay was used to detect the effect of lncRNA-BANCR on the invasive ability of thyroid cancer cells. Western blot was used to detect the changes of autophagy proteins LC3-I and LC3-II after the lncRNA-BANCR expression was suppressed.
 Results: Compared with normal thyroid tissues, the expression level of lncRNA-BANCR in thyroid carcinoma tissues was elevated (P<0.05). The expression of lncRNA-BANCR was positively related to the pathological stage of thyroid carcinoma and the lymph node metastasis. Inhibition of lncRNA-BANCR expression attenuated the proliferation and invasion ability of thyroid cancer cells (both P<0.05); but the apoptosis was enhanced (P<0.05); the expression levels of autophagy protein LC3-I and LC3-II were also increased (P<0.05).
 Conclusion: The expression level of lncRNA-BANCR affects the proliferation, invasion and apoptosis of thyroid cancer cells through modulation of autophagy behavior.
Apoptosis ; Autophagy ; Cell Proliferation ; Gene Expression Regulation, Neoplastic ; Humans ; Neoplasm Invasiveness ; Proto-Oncogene Proteins B-raf ; metabolism ; RNA, Long Noncoding ; metabolism ; Serine ; metabolism ; Threonine ; metabolism ; Thyroid Gland ; cytology ; metabolism ; Thyroid Neoplasms ; metabolism ; pathology

The aim of the present study was to investigate whether the physiological features of Ano1 were affected by enhanced green fluorescent protein (EGFP) fusing at Ano1 C-terminal. The eukaryotic expression vectors of Ano1 and EGFP-Ano1 were constructed, and these plasmids were transfected into Fischer rat thyroid follicular epithelial (FRT) cells using liposome. The expression and location of Ano1 were examined by using inverted fluorescence microscope. The ability of Ano1 to transport iodide was detected by kinetics experiment of fluorescence quenching. The results showed that both Ano1 and EGFP-Ano1 were expressed on FRT cell membrane and could be activated by Ca(2+). There was no significant difference of the ability to transport iodide between Ano1 and EGFP-Ano1. These results suggest Ano1 and EGFP-Ano1 have similar physiological feature.
Animals ; Anoctamin-1 ; Cell Membrane ; physiology ; Chloride Channels ; metabolism ; Epithelial Cells ; physiology ; Genetic Vectors ; Green Fluorescent Proteins ; metabolism ; Microscopy, Fluorescence ; Plasmids ; Rats ; Recombinant Fusion Proteins ; metabolism ; Thyroid Gland ; cytology ; Transfection

B-RafV600E mutant is found in 40-70% of papillary thyroid carcinoma (PTC) and has an important role in the pathogenesis of PTC. The sodium iodide symporter (NIS) is an integral plasma membrane glycoprotein that mediates active iodide transport into the thyroid follicular cells, and B-RafV600E has been known to be associated with the loss of NIS expression. In this study, we found that B-RafV600E inhibited NIS expression by the upregulation of its promoter methylation, and that specific regions of CpG islands of NIS promoter in B-RafV600E harboring PTC were highly methylated compared with surrounding normal tissue. Although DNA methyltransferase 3a and 3b (DNMT3a,3b) were not increased by B-RafV600E, DNMT1 expression was markedly upregulated in PTC and B-RafV600E expressing thyrocytes. Furthermore, DNMT1 expression was upregulated by B-RafV600E induced NF-kappaB activation. These results led us to conclude that NIS promoter methylation, which was induced by B-RafV600E, is one of the possible mechanisms involved in NIS downregulation in PTC.
Base Sequence ; Carcinoma/*genetics/metabolism/pathology ; Cells, Cultured ; DNA (Cytosine-5-)-Methyltransferase/analysis/*genetics/metabolism ; DNA Methylation ; Down-Regulation ; *Gene Expression Regulation, Neoplastic ; Humans ; Molecular Sequence Data ; *Point Mutation ; Promoter Regions, Genetic ; Proto-Oncogene Proteins B-raf/*genetics/metabolism ; Symporters/analysis/*genetics/metabolism ; Thyroid Gland/cytology/metabolism/pathology ; Thyroid Neoplasms/*genetics/metabolism/pathology ; Up-Regulation

Aim of the present study is to investigate activation effect of nobiletin on cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel activity. CFTR-mediated iodide influx assay and patch-clamp tests were done on FRT cells stably co-transfected with human CFTR and EYFP/H148Q. Nobiletin potently activated CFTR chloride channel activity in a dose- and time-dependent manner. The CFTR blocker CFTR(inh)-172 could completely reverse the effect. Preliminary mechanism study indicated that nobiletin activated CFTR chloride channel through a direct binding way. In addition, ex vivo tests done on mice trachea showed that nobiletin time-dependently stimulated submucosal gland fluid secretion. Nobiletin may be a therapeutic lead compound in treating CFTR-related diseases including disseminated bronchiectasis.
Animals ; Benzoates ; pharmacology ; Cystic Fibrosis Transmembrane Conductance Regulator ; antagonists & inhibitors ; drug effects ; metabolism ; Dose-Response Relationship, Drug ; Epithelial Cells ; metabolism ; Exocrine Glands ; secretion ; Flavones ; administration & dosage ; pharmacology ; Humans ; Mice ; Patch-Clamp Techniques ; Rats ; Rats, Inbred F344 ; Thiazolidines ; pharmacology ; Thyroid Gland ; cytology ; Time Factors ; Trachea ; secretion

OBJECTIVETo explore the toxic effect of fluoride on the human thyroid cells (Nthy-ori 3-1) and its mechanism.

METHODSNthy-ori 3-1 cells were exposed to 0.0, 0.1, 1.0, 3.0 mmol/L of sodium fluoride (NaF) in vitro. After 24 hours incubation, 3 (4,5-Dimethylthiazol-z-yl)-3, 5-diphenyltetrazolium bromide (MTT) assay and lactate dehydrogenase (LDH) assay were used to measure cell viability and the LDH leakage rate. Reactive oxygen species (ROS) level, constituent ratio of the cell cycle, and apoptosis rate were measured by flow cytometry.

RESULTSComparing to viability of control group (set as 100.00%), the cell viability of the 1.0, 3.0 mmol/L fluoride-treated groups (76.64 +/- 9.13)%, (64.04 +/- 6.32)% were significantly decreased (all P values <0.01). LDH leakage rate and ROS level of the 3.0 mmol/L fluoride-treated group ((48.66 +/-7.15)%, (29993.50 +/- 1786. 86) FI) were significantly increased (all P values <0.01) compared to control group ((35.24 +/- 3.02)%, (13021.33 +/- 1067.55) FI). The G0/G1 phase cells of the 1.0 mmol/L fluoride-treated group ((40.76 +/- 5.65)%) were lower than control group (60.09 +/- 1.76)% (P < 0.01), yet the percentage of cells in S phase ((54.05 +/- 4.59)%) were higher than the control group (32.59 +/- 2.43) % (P < 0.01). Comparing to control group ((9.64 +/- 3.44)%), the percentage of apoptosis cells increased in the 3.0 mmol/L fluoride-treated group ((20.09 +/- 3.22)%) (P < 0.01).

CONCLUSIONTo Nthy-ori 3-1 cells, fluoride under experimental concentrations decreases cell viability, improve the LDH leakage rate, and ROS level. It blocks the cells in S phase and induce cell apoptosis.

Apoptosis ; drug effects ; Cell Cycle ; Cell Division ; Cell Line ; Fluorides ; toxicity ; Humans ; Reactive Oxygen Species ; analysis ; Thyroid Gland ; cytology ; drug effects

This study is to investigate the activation effect of butyl-p-hydroxybenzoate (Bpb) on cAMP-dependent cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel gating. A stably transfected Fischer rat thyroid (FRT) epithelial cell lines co-expressing human CFTR and a green fluorescent protein mutant with ultra-high halide sensitivity (EYFP) were used to measure CFTR-mediated iodide influx rates. Bpb was identified as an effective activator of wild-type CFTR chloride channel, it can correct delta F508-CFTR gating defects but not processing defect. Bpb can't potentiate G551D-CFTR channel gating. The activity was reversible and dose-dependent. The study also provided clues that Bpb activates CFTR chloride channel through a direct binding mechanism. Our study identified Bpb as a novel structure CFTR activator. Bpb may be useful for probing CFTR channel gating mechanisms and as a lead compound to develop pharmacological therapy for CFTR-related disease.
Animals ; Cell Line ; Cystic Fibrosis Transmembrane Conductance Regulator ; genetics ; metabolism ; Dose-Response Relationship, Drug ; Epithelial Cells ; metabolism ; Green Fluorescent Proteins ; genetics ; metabolism ; Ion Channel Gating ; drug effects ; Mutation ; Parabens ; administration & dosage ; pharmacology ; Rats ; Rats, Inbred F344 ; Thyroid Gland ; cytology

OBJECTIVETo study the effect of different selenium intake on the expression of apoptosis protein Fas/FasL in experimental autoimmune thyroiditis (EAT) rats' thyroid with adequate iodine.

METHODSThirty-two female lewis rats were divided stochastically into 4 groups as C group, M group, Se(+) + M group, Se(-) + M group, respectively, and pretreated with feedstuffs containing different concentrations of selenium (Se(+) + M group 2 mg/kg, C and M group 0.20 mg/kg, Se(-) + M group 0.02 mg/kg, respectively) for two weeks, and immunized the rats with porcine thyroglobulin (pTg) to establish an EAT model. The thyroid gland was sampled, embedded in mineral wax and sliced, and the expression of Fas/FasL was measured with immunohistochemistry.

RESULTSBoth the expressions of Fas and FasL of EAT rats were significantly increased as compared with control group. The expression of Fas in rats' thyroid follicular cells with EAT was down-regulated as the increased selenium intake (optical density: 0.059 +/- 0.006), the expression of Fas of Se(+) + M group (0.036 +/- 0.004) was significantly inhibited (q = 11.591, P = 0.000), and expression of Fas was lower in the Se(+) + M group than Se(-) + M group (0.050 +/- 0.005) (q = 7.055 , P = 0.000). Effect of selenium on FasL was not identified.

CONCLUSIONIncreasing the intake of selenium might decrease the expression of Fas on thyroid follicular cells and restrain the development of EAT.

Animals ; Apoptosis ; Fas Ligand Protein ; biosynthesis ; Female ; Rats ; Rats, Inbred Lew ; Selenium ; pharmacology ; therapeutic use ; Thyroid Gland ; cytology ; metabolism ; Thyroiditis, Autoimmune ; drug therapy ; metabolism

Members of the inhibitors of differentiation (Id) family of helix-loop-helix (HLH) proteins are known to play important roles in the proliferation and differentiation of many cell types. Thyroid-stimulating hormone (TSH) regulates proliferation and differentiation by activating TSH receptor (TSHR) in thyrocytes. In this study, we found that Id2, one of the Id family proteins, is a major target for regulation by TSH in FRTL-5 thyroid cells. TSH rapidly increases the Id2 mRNA level in FRTL-5 thyroid cells but the Id2 protein showed biphasic regulatory patterns, being transiently reduced and subsequently induced by TSH treatment. Transient reduction of Id2 protein was noted within 2 hr of TSH treatment and was mediated by proteasomal degradation. Moreover, reduced Id2 expression correlated with the activity of the phosphatidylinositol 3 kinase pathway, which is activated by TSH. Although TSH increases the activity of the Id2 promoter, TSH-induced activation of this promoter was independent of c-Myc. Id2 did not alter TTF-1- and Pax-8-mediated effects on the regulation of the Tg promoter. Thus, in summary, we found that TSH regulates Id2 expression, but that Id2 does not alter the expression of thyroid-specific genes, such as Tg, in FRTL-5 thyroid cells.
1-Phosphatidylinositol 3-Kinase/metabolism ; Animals ; Cattle ; Cell Differentiation ; Cell Proliferation ; *Gene Expression Regulation ; Inhibitor of Differentiation Protein 2/metabolism ; Insulin/metabolism ; Paired Box Transcription Factors/metabolism ; Promoter Regions, Genetic ; Proto-Oncogene Proteins c-myc/metabolism ; Rats ; Thyroglobulin/metabolism ; Thyroid Gland/*cytology ; Thyrotropin/*metabolism

OBJECTIVETo observe the effects of amitrole on the transcription of thyroglobulin (tg), thyroid peroxidase (tpo), Na(+)/I- symporter (nis), Na(+)/I- symporter (nis), thyroid-stimulating hormone receptor (tshr), thyroid transcription factor 1 (ttf-1) and paired-domain protein-8 (pax-8) genes in FRTL-5 cells and investigate the mechanism of amitrole for intervening in thyroid hormone activity.

METHODSFRTL-5 cells were treated with amitrole at 0.001, 0.01 and 0.1 mg/ml for 24 h, respectively, after which the cells were collected for extraction of the total RNA. RT-PCR was used to examine the effects of amitrole on the transcription of tg, tpo, nis, tshr, pax-8 and ttf-1 genes in FRTL-5 cells.

RESULTSAmitrole significantly induced tg gene transcription at all the doses, but produced no obvious effects on tpo and nis gene transcription. At the concentration of 0.1 mg/ml, amitrole significantly reduced pax-8 and tshr gene transcription but increased ttf-1 gene transcription.

CONCLUSIONThe effects of amitrole on thyroid hormone activity may be related with its actions on tg, ttf-1, tshr and pax-8 gene transcription.

Amitrole ; toxicity ; Animals ; Cells, Cultured ; Enzyme Inhibitors ; toxicity ; Epithelial Cells ; cytology ; drug effects ; metabolism ; Nuclear Proteins ; genetics ; Rats ; Rats, Inbred F344 ; Receptors, Thyrotropin ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Thyroglobulin ; genetics ; Thyroid Gland ; cytology ; Thyroid Nuclear Factor 1 ; Transcription Factors ; genetics ; Transcription, Genetic ; drug effects