Abstract 349: Signal Transducer and Activator of Transcription 3 (Stat3) in the Matrix of Cardiomyocyte Mitochondria

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Kerstin Boengler ◽  
Ina Konietzka ◽  
Anita van de Sand ◽  
Denise Hilfiker-Kleiner ◽  
Gerd Heusch ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Western Blot ◽  
Outer Membrane ◽  
Confocal Laser ◽  
Signal Transducer ◽  
Confocal Laser Scan Microscopy ◽  
Marker Proteins ◽  
The Matrix ◽  
Transcription 3 ◽  
Phosphorylated Stat3

STAT3 (signal transducer and activator of transcription 3) transduces signals from the plasma membrane to the nucleus and is central for the cardioprotection by ischemic pre- and postconditioning. However, preliminary data suggest that STAT3 is also located in mitochondria. The aim of the present study was to confirm the presence of STAT3 in cardiomyocyte mitochondria, to elucidate its submitochondrial localization and to identify interacting proteins and the import mechanism of STAT3. STAT3 was detected by Western blot analysis in mitochondrial preparations from rat left ventricle (LV), which were negative for marker proteins of other subcellular compartments (sarcolemma, sarcoplasmic reticulum, nucleus, and cytosol). This finding was confirmed by confocal laser scan microscopy on mouse LV mitochondria (n=4). In contrast, no STAT3 was detected in mitochondria isolated from the LV of mice with a cardiomyocyte-specific deletion of STAT3 (n=3). Immunoprecipitation and confocal laser scan microscopy showed that, apart from total STAT3, also Ser727- and Tyr705-phosphorylated STAT3 was present in rat mitochondria. The analysis of subfractionated mitochondria by Western blot displayed STAT3 predominantly in the fraction negative for marker proteins of the outer membrane (voltage dependent anion channel), inner membrane (ATP synthase alpha), and the intermembrane space (cytochrome c), but positive for marker proteins of the matrix such as cyclophilin D (n=4). Immunoprecipitation of STAT3 from right ventricular and mitochondrial proteins showed a co-precipitation of connexin 43 (Cx43), which is present both at the sarcolemma and at the inner mitochondrial membrane and is also involved in cardioprotection, but not with GSK3β, MnSOD or cytochrome c. Furthermore, STAT3 co-precipitated with Tom20 (translocase of the outer membrane 20), which regulates the import of proteins into the mitochondria. Taken together, total and phosphorylated STAT3 are present in the matrix of cardiomyocyte mitochondria, STAT3 is possibly imported via a Tom20-dependent pathway, and STAT3 interacts with mitochondrial Cx43, and is thus possibly involved in Cx43-mediated cardioprotection.

scholarly journals Cloning of porcine signal transducer and activator of transcription 3 cDNA and its expression in reproductive tissues

Reproduction ◽  
2006 ◽  
Vol 132 (3) ◽  
pp. 511-518 ◽  
Author(s):  
Lihua Wen ◽  
Jesse Craig ◽  
Paul W Dyce ◽  
Julang Li
Keyword(s):  
Growth Factor ◽  
Ovarian Function ◽  
Control Level ◽  
Signal Transducer ◽  
Rt Pcr ◽  
Western Blots ◽  
Epidermal Growth ◽  
Mucosal Folds ◽  
Transcription 3 ◽  
Phosphorylated Stat3

The signal transducer and activator of transcription 3 (Stat3) protein is a member of the Stat family that has a variety of biological functions including cell growth, anti-apoptosis, and cell motility, depending on the cell type and stimulus. Recent studies have suggested that Stat3 plays an important role in embryo development. Although the Stat3 gene has been cloned in humans, mice, cow, and rats, its sequence in pigs is unknown. In the present study, the 2476 bp Stat3 cDNA was cloned using real time reverse transcriptase (RT)-PCR. Comparison of sequences across species revealed that the porcine Stat3 cDNA is 93 and 90% homologous to human and mouse respectively. To study the expression pattern of Stat3, RNA and protein were isolated from heart, lung, kidney, ovary, oviduct, and uterus tissues. RT-PCR and western blot indicated that Stat3 is expressed in all the tissues tested, and the level of expression is relatively high in tissues from the reproductive system. In addition, immunohistochemistry studies suggested that the Stat3 protein was present in the oocyte, granulosa, theca, and interstitial cells of the ovary, the mucosal folds in the oviduct, and both the epithelium and stromal layers in the endometrium. To study whether Stat3 is functional in responding to growth factor stimulation in the ovary, granulosa cells were isolated from large follicles (>3 mm) and cultured in the presence of epidermal growth factor (EGF; 10 ng/ml) for 5, 10, 15, 30, and 60 min, following which western blots were performed using an antibody against the phosphorylated Stat3. Phosphorylated Stat3 was upregulated following 5 min of EGF challenge and was sustained during the 15-min stimulation, and decreased back to the control level following 60-min stimulation. The translocation of phosphorylated Stat3 from cytoplasm to nucleus following stimulation of EGF was also detected via immunocytochemistry. Our data suggests that Stat3 may play a role in porcine ovarian function.

HDAC3 Silencing Enhances Acute B Lymphoblastic Leukaemia Cells Sensitivity to MG-132 by Inhibiting the JAK/Signal Transducer and Activator of Transcription 3 Signaling Pathway

Chemotherapy ◽  
2020 ◽  
Vol 65 (3-4) ◽  
pp. 85-100
Author(s):  
Yongling Guo ◽  
Xinyao Li ◽  
Zhengchang He ◽  
Dan Ma ◽  
Zhaoyuan Zhang ◽  
...  
Keyword(s):  
Western Blot ◽  
Therapeutic Strategy ◽  
Lymphocytic Leukaemia ◽  
Signal Transducer ◽  
Poor Survival ◽  
Stat3 Pathway ◽  
Cycle Arrest ◽  
M Phase ◽  
Interfering Rna ◽  
Transcription 3

<b><i>Purpose:</i></b> HDAC3, which is associated with smurf2, has been shown to be associated with poor prognosis in B-ALL. This study examined the efficacy of targeting HDAC3 combined with MG-132 as a possible therapeutic strategy for B-ALL patients. <b><i>Methods:</i></b> Real-time PCR and western blot were used to measure the expression of smurf2 and HDAC3 from B-ALL patients bone marrow samples. Sup-B15 and CCRF-SB cells were treated with MG-132, small interfering RNA of smurf2 or HDAC3. A plasmid designed to up-regulate smurf2 expression was transfected into B-ALL cells. Flow cytometry and western blot were used to measure variation due to these treatments in terms of apoptosis and cell cycle arrest. <b><i>Results:</i></b> Expression of Smurf2 and HDAC3 mRNA were inversely related in B-ALL patients. Up-regulation of smurf2 or MG-132 influenced HDAC3, further inhibiting the JAK/signal transducer and activator of transcription 3 (STAT3) signal pathway and inducing apoptosis in B-ALL cells. When we treated Sup-B15 and CCRF-SB cells with siHDAC3 and MG-132 for 24 h, silencing HDAC3 enhanced the apoptosis rate induced by MG-132 in B-ALL cells and further inhibited the JAK/STAT3 pathway. Furthermore, MG-132 was observed to cause G2/M phase arrest in B-ALL cells and inhibited the JAK/STAT3 pathway, leading to apoptosis. <b><i>Conclusions:</i></b> Silencing of HDAC3 enhanced the sensitivity of B-ALL cells to MG-132. The combination of targeting HDAC3 and MG-132 may provide a new avenue for clinical treatment of acute B lymphocytic leukaemia and improve the poor survival of leukaemia patients.

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.

Signal transducer and activator of transcription 3 is located in the matrix of cardiomyocyte mitochondria

2008 ◽  
Vol 44 (4) ◽  
pp. 762
Author(s):  
Kerstin Boengler ◽  
Ina Konietzka ◽  
Anita van de Sand ◽  
Denise Hilfiker-Kleiner ◽  
Gerd Heusch ◽  
...  
Keyword(s):  
Signal Transducer ◽  
The Matrix ◽  
Transcription 3

Hypoxia is a potent inducer of the iron masterswitch hepcidin via Signal Transducer and Activator of Transcription 3 (STAT3)

2017 ◽  
Author(s):  
I Silva ◽  
V Rausch ◽  
T Peccerella ◽  
G Millonig ◽  
HK Seitz ◽  
...  
Keyword(s):  
Signal Transducer ◽  
Potent Inducer ◽  
Transcription 3

Magnesium-dependent Phosphatase (MDP) 1 is a Potential Suppressor of Gastric Cancer

2019 ◽  
Vol 19 (10) ◽  
pp. 817-827
Author(s):  
Jianbo Zhu ◽  
Lijuan Deng ◽  
Baozhen Chen ◽  
Wenqing Huang ◽  
Xiandong Lin ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Dna Methylation ◽  
Cell Proliferation ◽  
Protein C ◽  
Biological Function ◽  
Prognostic Markers ◽  
Biological Effects ◽  
Signal Transducer ◽  
Gastric Cancer Cells ◽  
Transcription 3

Background:Recurrence is the leading cause of treatment failure and death in patients with gastric cancer (GC). However, the mechanism underlying GC recurrence remains unclear, and prognostic markers are still lacking.Methods:We analyzed DNA methylation profiles in gastric cancer cases with shorter survival (<1 year) or longer survival (> 3 years), and identified candidate genes associated with GC recurrence. Then, the biological effects of these genes on gastric cancer were studied.Results:A novel gene, magnesium-dependent phosphatase 1 (mdp1), was identified as a candidate gene whose DNA methylation was higher in GC samples from patients with shorter survival and lower in patients with longer survival. MDP1 protein was highly expressed in GC tissues with longer survival time, and also had a tendency to be expressed in highly differentiated GC samples. Forced expression of MDP1 in GC cell line BGC-823 inhibited cell proliferation, whereas the knockdown of MDP1 protein promoted cell growth. Overexpression of MDP1 in BGC-823 cells also enhanced cell senescence and apoptosis. Cytoplasmic kinase protein c-Jun N-terminal kinase (JNK) and signal transducer and activator of transcription 3 (Stat3) were found to mediate the biological function of MDP1.Conclusion:These results suggest that MDP1 protein suppresses the survival of gastric cancer cells and loss of MDP expression may benefit the recurrence of gastric cancer.

Sign in / Sign up

Export Citation Format

Share Document