scholarly journals Intranuclear Crosstalk between Extracellular Regulated Kinase1/2 and Signal Transducer and Activator of Transcription 3 Regulates JEG-3 Choriocarcinoma Cell Invasion and Proliferation

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Diana M. Morales-Prieto ◽  
Stephanie Ospina-Prieto ◽  
Wittaya Chaiwangyen ◽  
Maja Weber ◽  
Sebastian Hölters ◽  
...  
Keyword(s):  
Dna Binding ◽  
Binding Capacity ◽  
Mapk Signaling ◽  
Signaling Molecules ◽  
Signal Transducer ◽  
Stat3 Phosphorylation ◽  
Functional Implications ◽  
Choriocarcinoma Cells ◽  
Cell Invasiveness ◽  
Transcription 3

Invasiveness of trophoblast and choriocarcinoma cells is in part mediated via leukemia inhibitory factor- (LIF-) induced activation of signal transducer and activator of transcription 3 (STAT3). The regulation of STAT3 phosphorylation at its ser727 binding site, possible crosstalk with intracellular MAPK signaling, and their functional implications are the object of the present investigation. JEG-3 choriocarcinoma cells were cultured in presence/absence of LIF and the specific ERK1/2 inhibitor (U0126). Phosphorylation of signaling molecules (p-STAT3 (ser727 and tyr705) and p-ERK1/2 (thr 202/tyr 204)) was assessed per Western blot. Immunocytochemistry confirmed results, but also pinpointed the location of phosphorylated signaling molecules. STAT3 DNA-binding capacity was studied with a colorimetric ELISA-based assay. Cell viability and invasion capability were assessed by MTS and Matrigel assays. Our results demonstrate that LIF-induced phosphorylation of STAT3 (tyr705 and ser727) is significantly increased after blocking ERK1/2. STAT3 DNA-binding capacity and cell invasiveness are enhanced after LIF stimulation and ERK1/2 blockage. In contrast, proliferation is enhanced by LIF but reduced after ERK1/2 inhibition. The findings herein show that blocking ERK1/2 increases LIF-induced STAT3 phosphorylation and STAT3 DNA-binding capacity by an intranuclear crosstalk, which leads to enhanced invasiveness and reduced proliferation.

scholarly journals Increased Hypothalamic Signal Transducer and Activator of Transcription 3 Phosphorylation after Hindbrain Leptin Injection

Endocrinology ◽  
2010 ◽  
Vol 151 (4) ◽  
pp. 1509-1519 ◽  
Author(s):  
Marieke Ruiter ◽  
Patricia Duffy ◽  
Steven Simasko ◽  
Robert C. Ritter
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Fourth Ventricle ◽  
Leptin Receptor ◽  
Janus Kinase ◽  
Signal Transducer ◽  
Solitary Tract ◽  
Stat3 Signaling ◽  
Stat3 Phosphorylation ◽  
Transcription 3

Reduction of food intake and body weight by leptin is attributed largely to its action in the hypothalamus. However, the signaling splice variant of the leptin receptor, LRb, also is expressed in the hindbrain, and leptin injections into the fourth cerebral ventricle or dorsal vagal complex are associated with reductions of feeding and body weight comparable to those induced by forebrain leptin administration. Although these observations suggest direct hindbrain action of leptin on feeding and body weight, the possibility that hindbrain leptin administration also activates the Janus kinase/signal transducer and activator of transcription 3 (STAT3) signaling in the hypothalamus has not been investigated. Confirming earlier work, we found that leptin produced comparable reductions of feeding and body weight when injected into the lateral ventricle or the fourth ventricle. We also found that lateral and fourth ventricle leptin injections produced comparable increases of STAT3 phosphorylation in both the hindbrain and the hypothalamus. Moreover, injection of 50 ng of leptin directly into the nucleus of the solitary tract also increased STAT3 phosphorylation in the hypothalamic arcuate and ventromedial nuclei. Increased hypothalamic STAT3 phosphorylation was not due to elevation of blood leptin concentrations and the pattern of STAT3 phosphorylation did not overlap distribution of the retrograde tracer, fluorogold, injected via the same cannula. Our observations indicate that even small leptin doses administered to the hindbrain can trigger leptin-related signaling in the forebrain, and raise the possibility that STAT3 phosphorylation in the hypothalamus may contribute to behavioral and metabolic changes observed after hindbrain leptin injections.

Oncostatin M and leukaemia inhibitory factor trigger signal transducer and activator of transcription 3 and extracellular signal-regulated kinase 1/2 pathways but result in heterogeneous cellular responses in trophoblast cells

2016 ◽  
Vol 28 (5) ◽  
pp. 608 ◽  
Author(s):  
Wittaya Chaiwangyen ◽  
Stephanie Ospina-Prieto ◽  
Diana M. Morales-Prieto ◽  
Francisco Lazaro Pereira de Sousa ◽  
Jana Pastuschek ◽  
...  
Keyword(s):  
Dna Binding ◽  
Cell Lines ◽  
Binding Capacity ◽  
Binding Activity ◽  
Oncostatin M ◽  
Inhibitory Factor ◽  
Therapeutic Interventions ◽  
Leukaemia Inhibitory Factor ◽  
Tetrazolium Salt ◽  
Signal Transducer

Leukaemia inhibitory factor (LIF) and oncostatin M (OSM) are pleiotropic cytokines present at the implantation site that are important for the normal development of human pregnancy. These cytokines share the cell membrane receptor subunit gp130, resulting in similar functions. The aim of this study was to compare the response to LIF and OSM in several trophoblast models with particular regard to intracellular mechanisms and invasion. Four trophoblast cell lines with different characteristics were used: HTR-8/SVneo, JEG-3, ACH-3P and AC1-M59 cells. Cells were incubated with LIF, OSM (both at 10 ng mL–1) and the signal transducer and activator of transcription (STAT) 3 inhibitor S3I-201 (200 µM). Expression and phosphorylation of STAT3 (tyr705) and extracellular regulated kinase (ERK) 1/2 (thr202/204) and the STAT3 DNA-binding capacity were analysed by Western blotting and DNA-binding assays, respectively. Cell viability and invasiveness were assessed by the methylthiazole tetrazolium salt (MTS) and Matrigel assays. Enzymatic activity of matrix metalloproteinase (MMP)-2 and MMP-9 was investigated by zymography. OSM and LIF triggered phosphorylation of STAT3 and ERK1/2, followed by a significant increase in STAT3 DNA-binding activity in all tested cell lines. Stimulation with LIF but not OSM significantly enhanced invasion of ACH-3P and JEG-3 cells, but not HTR-8/SVneo or AC1-M59 cells. Similarly, STAT3 inhibition significantly decreased the invasiveness of only ACH-3P and JEG-3 cells concomitant with decreases in secreted MMP-2 and MMP-9. OSM shares with LIF the capacity to activate ERK1/2 and STAT3 pathways in all cell lines tested, but their resulting effects are dependent on cell type. This suggests that LIF and OSM may partially substitute for each other in case of deficiencies or therapeutic interventions.

scholarly journals Astaxanthin Ameliorates Lipopolysaccharide-Induced Neuroinflammation, Oxidative Stress and Memory Dysfunction through Inactivation of the Signal Transducer and Activator of Transcription 3 Pathway

Marine Drugs ◽  
2019 ◽  
Vol 17 (2) ◽  
pp. 123 ◽  
Author(s):  
Ji Han ◽  
Yong Lee ◽  
Jun Im ◽  
Young Ham ◽  
Hee Lee ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dna Binding ◽  
Inflammatory Responses ◽  
Memory Loss ◽  
Signal Transducer ◽  
Mice Model ◽  
Neuroinflammatory Response ◽  
Transcription 3

Astaxanthin (AXT), a xanthophyll carotenoid compound, has potent antioxidant, anti-inflammatory and neuroprotective properties. Neuroinflammation and oxidative stress are significant in the pathogenesis and development of Alzheimer’s disease (AD). Here, we studied whether AXT could alleviate neuroinflammation, oxidative stress and memory loss in lipopolysaccharide (LPS) administered mice model. Additionally, we investigated the anti-oxidant activity and the anti-neuroinflammatory response of AXT in LPS-treated BV-2 microglial cells. The AXT administration ameliorated LPS-induced memory loss. This effect was associated with the reduction of LPS-induced expression of inflammatory proteins, as well as the production of reactive oxygen species (ROS), nitric oxide (NO), cytokines and chemokines both in vivo and in vitro. AXT also reduced LPS-induced β-secretase and Aβ1–42 generation through the down-regulation of amyloidogenic proteins both in vivo and in vitro. Furthermore, AXT suppressed the DNA binding activities of the signal transducer and activator of transcription 3 (STAT3). We found that AXT directly bound to the DNA- binding domain (DBD) and linker domain (LD) domains of STAT3 using docking studies. The oxidative stress and inflammatory responses were not downregulated in BV-2 cells transfected with DBD-null STAT3 and LD-null STAT3. These results indicated AXT inhibits LPS-induced oxidant activity, neuroinflammatory response and amyloidogenesis via the blocking of STAT3 activity through direct binding.

scholarly journals P10.01 Anti-migration and anti-invasion effects of curcumin via suppression of fascin expression in glioblastoma cells

2019 ◽  
Vol 21 (Supplement_3) ◽  
pp. iii40-iii40
Author(s):  
P Ki-Su ◽  
S Yoon ◽  
J Hwang ◽  
H Ahn
Keyword(s):  
Western Blot ◽  
Tumor Cells ◽  
Natural Compound ◽  
Sandwich Elisa ◽  
Actin Binding ◽  
Migration And Invasion ◽  
Signal Transducer ◽  
Stat3 Phosphorylation ◽  
Transcription 3 ◽  
Invasion Assays

Abstract BACKGROUND The natural compound Curcumin was known to inhibit migration and invasion of glioblastoma (GBM) cells. Fascin, a kind of actin-binding proteins, is correlated with migration and invasion of GBM cells. The purpose of this study was to investigate anti-migration and anti-invasion effects of Curcumin via suppression of fascin expression in GBM cells. MATERIAL AND METHODS U87 cell line was used as an experimental model of GBM. Fascin was quantified by Western blot analysis. And, the signal transducer and activator of transcription 3 (STAT3), known to play an important role in migration and invasion of tumor cells, were analyzed by sandwich-ELISA. Migration and invasion capacities were assessed by attachment, migration and invasion assays. Cellular morphology was demonstrated by immunofluorescence. RESULTS At various concentrations of curcumin and exposure times, fascin expression decreased. After temporarily exposure to 10μM/L Curcumin during 6 hours as less invasive concentration and time, fascin expression temporarily decreased at 12 hours (18.4%, p=0.024), and since then recovered. And, the change of phosphrylated STAT3 level also reflected the temporarily decreased pattern of fascin expression at 12 hours (19.7%, p=0.010). Attachment, migration, and invasion capacities consistently decreased at 6, 12, and 24 hours. And, immunofluorescence showed the change of shape and the reduction of filopodia formation in cells. CONCLUSION Curcumin is likely to suppress the fascin expression in GBM cells, and this might be a possible mechanism for anti-migration and anti-invasion effects of Curcumin via inhibition of STAT3 phosphorylation.

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