scholarly journals Functional interaction between p75NTR and TrkA: the endocytic trafficking of p75NTR is driven by TrkA and regulates TrkA-mediated signalling

2004 ◽  
Vol 385 (1) ◽  
pp. 233-241 ◽  
Author(s):  
Lorena PERRONE ◽  
Simona PALADINO ◽  
Marialuisa MAZZONE ◽  
Lucio NITSCH ◽  
Massimo GULISANO ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Cellular Localization ◽  
Basolateral Membrane ◽  
Neurotrophin Receptor ◽  
Epithelial Tissue ◽  
Thyroid Cells ◽  
Basolateral Side ◽  
Specific Stimulation ◽  
Rat Thyroid

The topology and trafficking of receptors play a key role in their signalling capability. Indeed, receptor function is related to the microenvironment inside the cell, where specific signalling molecules are compartmentalized. The response to NGF (nerve growth factor) is strongly dependent on the trafficking of its receptor, TrkA. However, information is still scarce about the role of the cellular localization of the TrkA co-receptor, p75NTR (where NTR is neurotrophin receptor), following stimulation by NGF. It has been shown that these two receptors play a key role in epithelial tissue and in epithelial-derived tumours, where the microenvironment at the plasma membrane is defined by the presence of tight junctions. Indeed, in thyroid carcinomas, rearrangements of TrkA are frequently found, which produce TrkA mutants that are localized exclusively in the cytoplasm. We used a thyroid cellular model in which it was possible to dissect the trafficking of the two NGF receptors upon neurotrophin stimulation. In FRT (Fischer rat thyroid) cells, endogenous TrkA is localized exclusively on the basolateral surface, while transfected p75NTR is selectively distributed on the apical membrane. This cellular system enabled us to selectively stimulate either p75NTR or TrkA and to analyse the role of receptor trafficking in their signalling capability. We found that, after binding to NGF, p75NTR was co-immunoprecipitated with TrkA and was transcytosed at the basolateral membrane. We showed that the TrkA–p75NTR interaction is necessary for this relocation of p75NTR to the basolateral side. Interestingly, TrkA-specific stimulation by basolateral NGF loading also induced the TrkA–p75NTR interaction and subsequent p75NTR transcytosis at the basolateral surface. Moreover, specific stimulation of p75NTR by NGF activated TrkA and the MAPK (mitogen-activated protein kinase) pathway. Our data indicate that TrkA regulates the subcellular localization of p75NTR upon stimulation with neurotrophins, thus affecting the topology of the signal transduction molecules, driving the activation of a specific signal transduction pathway.

scholarly journals microRNA-339-5p modulates Na+/I− symporter-mediated radioiodide uptake

2014 ◽  
Vol 22 (1) ◽  
pp. 11-21 ◽  
Author(s):  
Aparna Lakshmanan ◽  
Anna Wojcicka ◽  
Marta Kotlarek ◽  
Xiaoli Zhang ◽  
Krystian Jazdzewski ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Radioiodine Therapy ◽  
Expression Profiles ◽  
Hek293 Cells ◽  
Human Breast ◽  
Thyroid Cells ◽  
Promising Therapeutic Target ◽  
Rat Thyroid ◽  
Mcf 7

Na+/I−symporter (NIS)-mediated radioiodide uptake (RAIU) serves as the basis for targeted ablation of thyroid cancer remnants. However, many patients with thyroid cancer have reduced NIS expression/function and hence do not benefit from radioiodine therapy. microRNA (miR) has emerged as a promising therapeutic target in many diseases; yet, the role of miRs in NIS-mediated RAIU has not been investigated.In silicoanalysis was used to identify miRs that may bind to the 3′UTR of humanNIS(hNIS). The top candidate miR-339-5p directly bound to the 3′UTR of hNIS. miR-339-5p overexpression decreased NIS-mediated RAIU in HEK293 cells expressing exogenous hNIS, decreased the levels ofNISmRNA, and RAIU in transretinoic acid/hydrocortisone (tRA/H)-treated MCF-7 human breast cancer cells as well as thyrotropin-stimulated PCCl3 rat thyroid cells. Nanostring nCounter rat miR expression assay was conducted to identify miRs deregulated by TGFβ, Akti-1/2, or 17-AAG known to modulate RAIU in PCCl3 cells. Among 38 miRs identified, 18 were conserved in humans. One of the 18 miRs, miR-195, was predicted to bind to the 3′UTR of hNISand its overexpression decreased RAIU in tRA/H-treated MCF-7 cells. miR-339-5p was modestly increased in most papillary thyroid carcinomas (PTCs), yet miR-195 was significantly decreased in PTCs. Interestingly, the expression profiles of 18 miRs could be used to distinguish most PTCs from nonmalignant thyroid tissues. This is the first report, to our knowledge, demonstrating that hNIS-mediated RAIU can be modulated by miRs, and that the same miRs may also play roles in the development or maintenance of thyroid malignancy. Accordingly, miRs may serve as emerging targets to halt the progression of thyroid cancer and to enhance the efficacy of radioiodine therapy.

Genistein but not staurosporine can inhibit the mitogenic signal evoked by lithium in rat thyroid cells (FRTL-5)

1994 ◽  
Vol 143 (2) ◽  
pp. 221-226 ◽  
Author(s):  
T Takano ◽  
K Takada ◽  
H Tada ◽  
S Nishiyama ◽  
N Amino
Keyword(s):  
Signal Transduction ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Tyrosine Kinase ◽  
Dna Synthesis ◽  
Thyroid Cells ◽  
Kinase C ◽  
Mitogenic Signal Transduction ◽  
Rat Thyroid ◽  
Mitogenic Signal

Abstract Long-term administration of lithium is one of the well-known causes of goiter. It can stimulate DNA synthesis in rat thyroid cells (FRTL-5) treated with thyroid-stimulating hormone (TSH). To investigate the mitogenic signal transduction system activated by lithium, lithium-induced DNA synthesis and Ca2+ influx were studied using two protein kinase inhibitors, genistein as a specific tyrosine kinase inhibitor and staurosporine as a potent inhibitor of protein kinase C. Genistein but not staurosporine blocked the DNA synthesis induced by lithium in TSH-primed cells but neither compound had any effect on the Ca2+ entry stimulated by lithium. Genistein clearly attenuated the phosphotyrosine content of the 175 kDa substrate in the presence of lithium but staurosporine failed to do so. Moreover, lithium could also stimulate DNA synthesis in protein kinase C down-regulated cells. These data demonstrate that lithium may require the activation of a particular genistein-sensitive kinase, possibly a tyrosine kinase, to induce cell proliferation. It is suggested that the phorbol ester-sensitive protein kinase C family might not participate in the mitogenic signal transduction pathway activated by lithium. Journal of Endocrinology (1994) 143, 221–226

scholarly journals Phosphoinositide 3-kinase inhibits megalin-mediated transcytosis of thyroglobulin across thyroid epithelial cells at a post-sorting level

2001 ◽  
pp. 477-483 ◽  
Author(s):  
M Marino ◽  
L Chiovato ◽  
S Lisi ◽  
A Pinchera ◽  
RT McCluskey
Keyword(s):  
Low Density Lipoprotein ◽  
Specific Inhibitor ◽  
Density Lipoprotein ◽  
Inhibitory Effect ◽  
Thyroid Cells ◽  
Microbial Product ◽  
Phosphoinositide 3 Kinase ◽  
Rat Thyroid ◽  
Upper Chamber

BACKGROUND: Phosphoinositide 3-kinase (PI3-K) is implicated in various cellular processes involving signaling, including intracellular trafficking. PI3-K has been shown to play a part in both receptor- and non-receptor-mediated transcytosis across cultured kidney cells and undifferentiated thyroid cells. OBJECTIVE: To investigate the role of PI3-K in transcytosis of thyroglobulin (Tg) across differentiated cultured Fisher rat thyroid cells (FRTL-5 cells) - a process known to be mediated by megalin, a member of the low-density lipoprotein receptor family. DESIGN: We studied the effect of the microbial product wortmannin, a specific inhibitor of PI3-K, on transcytosis of Tg across FRTL-5 cells. METHODS: Transcytosis experiments were performed using FRTL-5 cells cultured as tight layers on filters in the upper chamber of dual chambered devices, with megalin expression exclusively on the upper cell surface. Tg was added to the upper chamber and cells were incubated at 37 degrees C. Transcytosed Tg was measured in fluids collected from the lower chamber. To study the role of PI3-K, cells were pre-incubated with wortmannin. RESULTS: Pre-incubation of FRTL-5 cells with wortmannin did not affect Tg binding and uptake, but resulted in a considerable increase in Tg transcytosis (by 40-75%, depending on the concentration of wortmannin), suggesting that PI3-K exerts an inhibitory effect on Tg transcytosis. In experiments in which a monoclonal antibody against megalin was used to reduce Tg transcytosis, pre-incubation with wortmannin did not increase Tg transcytosis from its reduced levels, indicating that PI3-K is involved in the megalin-mediated pathway. Wortmannin did not affect the extent of release of tri-iodothyronine from exogenously added Tg by FRTL-5 cells, which was used as a measure of Tg degradation in the lysosomal pathway, indicating that the effect of PI3-K on transcytosis occurs after diversion of Tg from the lysosomal pathway. CONCLUSIONS: PI3-K exerts an inhibitory role on megalin-mediated Tg transcytosis across cultured thyroid cells. PI3-K action takes place at a post-sorting level, after Tg bypassing of the lysosomal pathway.

MCT1 and its accessory protein CD147 are differentially regulated by TSH in rat thyroid cells

2003 ◽  
Vol 285 (6) ◽  
pp. E1223-E1229 ◽  
Author(s):  
Albertina Fanelli ◽  
Evelyn F. Grollman ◽  
Dian Wang ◽  
Nancy J. Philp
Keyword(s):  
Lactic Acid ◽  
Protein Expression ◽  
Aerobic Glycolysis ◽  
Basolateral Membrane ◽  
Thyroid Tissue ◽  
Accessory Protein ◽  
Thyroid Cells ◽  
Cd147 Expression ◽  
Rat Thyroid ◽  
Dependent Mechanism

In thyroid cells, basal and TSH-stimulated glycolysis is associated with lactic acid efflux. In this report, we address whether monocarboxylate transporters (MCTs) are present in thyroid tissue for exporting excess lactic acid generated by aerobic glycolysis. Using immunostaining techniques, we show that MCT4 localizes with its accessory protein CD147 in the basolateral membrane of rat thyroid follicular cells. In cultured rat thyroid (FRTL-5) cells, MCT1 rather than MCT4 is expressed. CD147 colocalizes and coimmunoprecipitates with MCT1. TSH upregulates MCT1/CD147 expression as a function of time through a cAMP-dependent mechanism as forskolin reproduces the effect of TSH. TSH enhances protein expression of both MCT1 and CD147 in FRTL-5 cells. Whereas MCT1 protein expression is controlled at the level of transcription, CD147 protein expression is regulated by a posttranscriptional mechanism. Results of these studies suggest that hormone stimulation of lactate transport is mediated by regulating MCT1 transcription.

scholarly journals RET/PTC-induced gene expression in thyroid PCCL3 cells reveals early activation of genes involved in regulation of the immune response

2005 ◽  
Vol 12 (2) ◽  
pp. 319-334 ◽  
Author(s):  
E Puxeddu ◽  
J A Knauf ◽  
M A Sartor ◽  
N Mitsutake ◽  
E P Smith ◽  
...  
Keyword(s):  
Gene Expression ◽  
Signal Transduction ◽  
Immune Response ◽  
Critical Role ◽  
Expression Change ◽  
Thyroid Cells ◽  
Functional Clustering ◽  
Cytokines And Chemokines ◽  
Intracellular Signal

RET/PTC rearrangements represent key genetic events involved in papillary thyroid carcinoma (PTC) initiation. The aim of the present study was to identify the early changes in gene expression induced by RET/PTC in thyroid cells. For this purpose, microarray analysis was conducted on PCCL3 cells conditionally expressing the RET/PTC3 oncogene. Gene expression profiling 48 h after activation of RET/PTC3 identified a statistically significant modification of expression of 270 genes. Quantitative PCR confirmation of 20 of these demonstrated 90% accuracy of the microarray. Functional clustering of genes with greater than or less than 1.75-fold expression change (86 genes) revealed RET/PTC3-induced regulation of genes with key functions in apoptosis (Ripk3, Tdga), cell–cell signaling (Cdh6, Fn1), cell cycle (Il24), immune and inflammation response (Cxcl10, Scya2, Il6, Gbp2, Oas1, Tap1, RT1Aw2, C2ta, Irf1, Lmp2, Psme2, Prkr), metabolism (Aldob, Ptges, Nd2, Gss, Gstt1), signal transduction (Socs3, Nf1, Jak2, Cpg21, Dusp6, Socs1, Stat1, Stat3, Cish) and transcription (Nr4a1, Junb, Hfh1, Runx1, Foxe1). Genes coding for proteins involved in the immune response and in intracellular signal transduction pathways activated by cytokines and chemokines were strongly represented, indicating a critical role of RET/PTC3 in the early modulation of the immune response.

Thyrotrophin and cyclic AMP regulation of thyroglobulin gene expression in cultured porcine thyroid cells

1988 ◽  
Vol 116 (1) ◽  
pp. 25-33 ◽  
Author(s):  
O. Chabaud ◽  
M. Chambard ◽  
N. Gaudry ◽  
J. Mauchamp
Keyword(s):  
Gene Expression ◽  
Cyclic Amp ◽  
Cholera Toxin ◽  
Basolateral Membrane ◽  
Synthesis Rate ◽  
Maximal Response ◽  
Thyroid Cells ◽  
Basolateral Side ◽  
Mrna Content ◽  
Thyroglobulin Gene

ABSTRACT The effects of thyrotrophin, cholera toxin and 8-chloro-cyclic AMP on thyroglobulin gene expression in cultured porcine thyroid cells were compared. Cells organized either into monolayers in culture chambers with porous bases or into inside-out follicles in suspension were used. Thyroglobulin mRNA content was measured by dot-blot hybridization, and thyroglobulin synthesis rate was determined by immunoprecipitation of [35S]thyroglobulin after 2 h labelling with [35S]methionine. Cholera toxin and 8-chlorocyclic AMP increased the thyroglobulin mRNA content and thyroglobulin synthesis rate in the same ratio (∼3) as did thyrotrophin, showing that cyclic AMP mediates the effect of thyrotrophin on thyroglobulin gene expression. The culture chamber system provides for contact of the effectors with either the apical or the basolateral membrane. The addition of 0·02–0·1 mU thyrotrophin/ml on the basolateral side of the cell layer gave a maximal response whereas this response was not reached on the apical side even with the addition of 5 mU/ml. In contrast, cholera toxin and 8-chloro-cyclic AMP stimulated thyroid cells equally on both sides. J. Endocr. (1988) 116, 25–33

scholarly journals Detergent-insoluble GPI–anchored Proteins Are Apically Sorted in Fischer Rat Thyroid Cells, but Interference with Cholesterol or Sphingolipids Differentially Affects Detergent Insolubility and Apical Sorting

2000 ◽  
Vol 11 (2) ◽  
pp. 531-542 ◽  
Author(s):  
Concetta Lipardi ◽  
Lucio Nitsch ◽  
Chiara Zurzolo
Keyword(s):  
Alkaline Phosphatase ◽  
Lipid Rafts ◽  
Neurotrophin Receptor ◽  
Apical Surface ◽  
Placental Alkaline Phosphatase ◽  
Thyroid Cells ◽  
Gpi Proteins ◽  
Rat Thyroid ◽  
Apical Sorting ◽  
Triton X

In contrast to Madin–Darby canine kidney cells, Fischer rat thyroid cells deliver the majority of endogenous glycosylphosphatidyl inositol (GPI)–anchored proteins to the basolateral surface. However, we report here that the GPI proteins Placental Alkaline Phosphatase (PLAP) and Neurotrophin Receptor–Placental Alkaline Phosphatase (NTR-PLAP) are apically localized in transfected Fischer rat thyroid cells. In agreement with the “raft hypothesis,” which postulates the incorporation of GPI proteins into glycosphingolipids and cholesterol-enriched rafts, we found that both of these proteins were insoluble in Triton X-100 and floated into the lighter fractions of sucrose density gradients. However, disruption of lipid rafts by removal of cholesterol did not cause surface missorting of PLAP and NTR-PLAP, and the altered surface sorting of these proteins after Fumonisin B1 treatment did not correlate with reduced levels in Triton X-100 –insoluble fractions. Furthermore, in contrast to the GPI-anchored forms of both of these proteins, the secretory and transmembrane forms (in the absence of a basolateral cytoplasmic signal) were sorted to the apical surface without association with lipid microdomains. Together, these data demonstrate that the GPI anchor is required to mediate raft association but is not sufficient to determine apical sorting. They also suggest that signals present in the ectodomain of the proteins play a major role and that lipid rafts may facilitate the recognition of these signals in thetrans-Golgi network, even though they are not required for apical sorting.

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