scholarly journals Metallothionein Expression and its Influence on the In Vitro Biological Behavior of Mucoepidermoid Carcinoma

Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 157
Author(s):  
João Rafael Habib Souza Aquime ◽  
Lara Carolina D’Araújo Pinto Zampieri ◽  
Maria Sueli da Silva Kataoka ◽  
Nelson Antonio Bailão Ribeiro ◽  
Ruy Gastaldoni Jaeger ◽  
...  
Keyword(s):  
Mucoepidermoid Carcinoma ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Biological Behavior ◽  
Migration And Invasion ◽  
Transforming Growth Factor Α ◽  
Protein Levels ◽  
Tnf Α ◽  
Factor Α

Mucoepidermoid carcinoma (MEC) is the most common tumor in the salivary glands, often presenting with recurrence and metastasis due to its high invasive capacity. Metallothionein (MT), a zinc storage protein that supplies this element for protease activity, is probably related to mucoepidermoid carcinoma behavior. This prompted us to characterize a cell line derived from mucoepidermoid carcinoma and to correlate metallothionein expression with transforming growth factor-α (TGF-α), tumor necrosis factor-α (TNF-α) and matrix metalloproteinases (MMPs). Transcriptomic analysis and cytogenetic assays were performed to detect the expression of genes of interest and cellular chromosomal alterations, respectively. MEC cells with a depleted metallothionein 2A (MT2A) gene were subjected to Western blot to correlate metallothionein expression with growth factors and MMPs. Additionally, cells with depleted MT were subjected to migration and invasion assays. The transcriptomic study revealed reads mapped to cytokeratins 19 and AE1/AE3, α-smooth muscle actin, vimentin, and fibronectin. Cytogenetic evaluation demonstrated structural and numerical alterations, including the translocation t(11;19)(q21;p13), characteristic of MEC. Metallothionein depletion was correlated with the decreased expression of TGF-α and MMP-9, while TNF-α protein levels were augmented. Migration and invasion activity were diminished after metallothionein silencing. Our findings suggest an important role of MT in MEC invasion, through the regulation of proteins involved in this process.

scholarly journals Tumor Necrosis Factor-α Triggers Mucus Production in Airway Epithelium through an IκB Kinase β-dependent Mechanism

2005 ◽  
Vol 280 (43) ◽  
pp. 36510-36517 ◽  
Author(s):  
José M. Lora ◽  
Dong Mei Zhang ◽  
Sha Mei Liao ◽  
Timothy Burwell ◽  
Anne Marie King ◽  
...  
Keyword(s):  
Airway Epithelium ◽  
Transforming Growth Factor ◽  
Mucus Production ◽  
Transforming Growth Factor Α ◽  
Iκb Kinase ◽  
Tnf Α ◽  
Factor Α

Excessive mucus production by airway epithelium is a major characteristic of a number of respiratory diseases, including asthma, chronic bronchitis, and cystic fibrosis. However, the signal transduction pathways leading to mucus production are poorly understood. Here we examined the potential role of IκB kinase β (IKKβ) in mucus synthesis in vitro and in vivo. Tumor necrosis factor-α (TNF-α) or transforming growth factor-α stimulation of human epithelial cells resulted in mucus secretion as measured by MUC5AC mRNA and protein. TNF-α stimulation induced IKKβ-dependent p65 nuclear translocation, mucus synthesis, and production of cytokines from epithelial cells. TNF-α, but not transforming growth factor-α, induced mucus production dependent on IKKβ-mediated NF-κB activation. In vivo, TNF-α induced NF-κB as determined by whole mouse body bioluminescence. This activation was localized to the epithelium as revealed by LacZ staining in NF-κB-LacZ transgenic mice. TNF-α-induced mucus production in vivo could also be inhibited by administration into the epithelium of an IKKβ dominant negative adenovirus. Taken together, our results demonstrated the important role of IKKβ in TNF-α-mediated mucus production in airway epithelium in vitro and in vivo.

Recognition sequences and structural elements contribute to shedding susceptibility of membrane proteins

2001 ◽  
Vol 353 (3) ◽  
pp. 663-672 ◽  
Author(s):  
Katja ALTHOFF ◽  
Jürgen MÜLLBERG ◽  
Dorthe AASLAND ◽  
Nicole VOLTZ ◽  
Karl-Josef KALLEN ◽  
...  
Keyword(s):  
Cleavage Site ◽  
Structural Changes ◽  
Phorbol Esters ◽  
Transforming Growth Factor ◽  
Proximal Region ◽  
Leukaemia Inhibitory Factor ◽  
Transforming Growth Factor Α ◽  
Tnf Α ◽  
Interleukin 6 Receptor ◽  
Factor Α

Although regulated ectodomain shedding affects a large panel of structurally and functionally unrelated proteins, little is known about the mechanisms controlling this process. Despite a lack of sequence similarities around cleavage sites, most proteins are shed in response to the stimulation of protein kinase C by phorbol esters. The signal-transducing receptor subunit gp130 is not a substrate of the regulated shedding machinery. We generated several chimaeric proteins of gp130 and the proteins tumour necrosis factor α (TNF-α), transforming growth factor α (TGF-α) and interleukin 6 receptor (IL-6R), which are known to be subject to shedding. By exchanging small peptide sequences of gp130 for cleavage-site peptides of TNF-α, TGF-α and IL-6R we showed that these short sequences conferred susceptibility to spontaneous and phorbol-ester-induced shedding of gp130. Importantly, these chimaeric gp130 proteins were functional, as shown by the phosphorylation of gp130 and the activation of signal transduction and activators of transcription 3 (‘STAT3’) on stimulation with cytokine. To investigate minimal requirements for shedding, truncated cleavage-site peptides of IL-6R were inserted into gp130. The resulting chimaeras were susceptible to shedding and showed the same cleavage pattern as observed in the chimaeras containing the complete IL-6R cleavage site. Surprisingly, we could also generate cleavable chimaeras by exchanging the juxtamembrane sequence of gp130 for the corresponding region of leukaemia inhibitory factor (‘LIF’) receptor, a protein that like gp130 is not subject to regulated or spontaneous shedding. Thus it seems that there is no minimal consensus shedding sequence. We speculate that structural changes allow the access of the protease to a membrane-proximal region, leading to shedding of the protein.

scholarly journals Enhanced Cerebral Expression of MCT1 and MCT2 in a Rat Ischemia Model Occurs in Activated Microglial Cells

2009 ◽  
Vol 29 (7) ◽  
pp. 1273-1283 ◽  
Author(s):  
Tiago JTP Moreira ◽  
Karin Pierre ◽  
Fumihiko Maekawa ◽  
Cendrine Repond ◽  
Aleta Cebere ◽  
...  
Keyword(s):  
Protein Expression ◽  
Mrna Level ◽  
Protein Levels ◽  
Microglial Cell Line ◽  
Tnf Α ◽  
Ischemic Episode ◽  
Isolectin B4 ◽  
Factor Α ◽  
Necrosis Factor

Monocarboxylate transporters (MCTs) are essential for the use of lactate, an energy substrate known to be overproduced in brain during an ischemic episode. The expression of MCT1 and MCT2 was investigated at 48 h of reperfusion from focal ischemia induced by unilateral extradural compression in Wistar rats. Increased MCT1 mRNA expression was detected in the injured cortex and hippocampus of compressed animals compared to sham controls. In the contralateral, uncompressed hemisphere, increases in MCT1 mRNA level in the cortex and MCT2 mRNA level in the hippocampus were noted. Interestingly, strong MCT1 and MCT2 protein expression was found in peri-lesional macrophages/microglia and in an isolectin B4+/S100β+ cell population in the corpus callosum. In vitro, MCT1 and MCT2 protein expression was observed in the N11 microglial cell line, whereas an enhancement of MCT1 expression by tumor necrosis factor-α (TNF-α) was shown in these cells. Modulation of MCT expression in microglia suggests that these transporters may help sustain microglial functions during recovery from focal brain ischemia. Overall, our study indicates that changes in MCT expression around and also away from the ischemic area, both at the mRNA and protein levels, are a part of the metabolic adaptations taking place in the brain after ischemia.

Transforming growth factor-α directly augments histidine decarboxylase and vesicular monoamine transporter 2 production in rat enterochromaffin-like cells

2004 ◽  
Vol 286 (3) ◽  
pp. G508-G514 ◽  
Author(s):  
Hideaki Kazumori ◽  
Shunji Ishihara ◽  
Mohammad A. K. Rumi ◽  
Cesar F. Ortega-Cava ◽  
Yasunori Kadowaki ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Histidine Decarboxylase ◽  
Vesicular Monoamine Transporter ◽  
Vesicular Monoamine Transporter 2 ◽  
Transforming Growth Factor Α ◽  
Ecl Cells ◽  
Factor Α

For the production and vesicle storage of histamine, Enterochromaffin-like (ECL) cells express histidine decarboxylase (HDC) and vesicular monoamine transporter 2 (VMAT2). Although HDC and VMAT2 show dynamic changes during gastric ulcer healing, the control system of their expression has not been fully investigated. In the present study, we investigated the effect of transforming growth factor-α (TGF-α) and proinflammatory cytokines on HDC and VMAT2 expression in rat ECL cells. Time course changes in the expression of TGF-α during the healing of acetic acid-induced ulcers were studied. EGF receptor (EGFR) expression was also examined in ECL cells, whereas the direct effects of TGF-α and proinflammatory cytokines on HDC and VMAT2 expression in ECL cells were investigated using in vivo and in vitro models. During the process of ulcer healing, expression of TGF-α mRNA was markedly augmented. Furthermore, EGFR was identified in isolated ECL cells. TGF-α stimulated HDC and VMAT2 mRNA expression and protein production and also increased histamine release from ECL cells. Selective EGFR tyrosine kinase inhibitor tyrphostin AG1478 almost completely inhibited HDC and VMAT2 gene expression induced by TGF-α in vivo and in vitro. During gastric mucosal injury, TGF-α was found to stimulate ECL cell functions by increasing HDC and VMAT2 expression.

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