scholarly journals Activation of the Hippo Pathway in Rana sylvatica: Yapping Stops in Response to Anoxia

Life ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1422
Author(s):  
Aakriti Gupta ◽  
Kenneth B. Storey
Keyword(s):  
Dna Binding ◽  
Gene Transcription ◽  
Hippo Pathway ◽  
Rana Sylvatica ◽  
Whole Body ◽  
Nuclear Fraction ◽  
Wood Frogs ◽  
Downstream Targets ◽  
Protein Levels ◽  
The Hippo Pathway

Wood frogs (Rana sylvatica) display well-developed anoxia tolerance as one component of their capacity to endure prolonged whole-body freezing during the winter months. Under anoxic conditions, multiple cellular responses are triggered to efficiently cope with stress by suppressing gene transcription and promoting activation of mechanisms that support cell survival. Activation of the Hippo signaling pathway initiates a cascade of protein kinase reactions that end with phosphorylation of YAP protein. Multiple pathway components of the Hippo pathway were analyzed via immunoblotting, qPCR or DNA-binding ELISAs to assess the effects of 24 h anoxia and 4 h aerobic recovery, compared with controls, on liver and heart metabolism of wood frogs. Immunoblot results showed significant increases in the relative levels of multiple proteins of the Hippo pathway representing an overall activation of the pathway in both organs under anoxia stress. Upregulation of transcript levels further confirmed this. A decrease in YAP and TEAD protein levels in the nuclear fraction also indicated reduced translocation of these proteins. Decreased DNA-binding activity of TEAD at the promoter region also suggested repression of gene transcription of its downstream targets such as SOX2 and OCT4. Furthermore, changes in the protein levels of two downstream targets of TEAD, OCT4 and SOX2, established regulated transcriptional activity and could possibly be associated with the activation of the Hippo pathway. Increased levels of TAZ in anoxic hearts also suggested its involvement in the repair mechanism for damage caused to cardiac muscles during anoxia. In summary, this study provides the first insights into the role of the Hippo pathway in maintaining cellular homeostasis in response to anoxia in amphibians.

scholarly journals The role of MEF2 transcription factors in dehydration and anoxia survival inRana sylvaticaskeletal muscle

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4014 ◽  
Author(s):  
Myriam P. Hoyeck ◽  
Hanane Hadj-Moussa ◽  
Kenneth B. Storey
Keyword(s):  
Glucose Transporter ◽  
Protein Quality ◽  
Brain Activity ◽  
Rana Sylvatica ◽  
Wood Frogs ◽  
Downstream Targets ◽  
Protein Levels ◽  
Glut4 Expression ◽  
Vital Functions

The wood frog (Rana sylvatica) can endure freezing of up to 65% of total body water during winter. When frozen, wood frogs enter a dormant state characterized by a cessation of vital functions (i.e., no heartbeat, blood circulation, breathing, brain activity, or movement). Wood frogs utilize various behavioural and biochemical adaptations to survive extreme freezing and component anoxia and dehydration stresses, including a global suppression of metabolic functions and gene expression. The stress-responsive myocyte enhancer factor-2 (MEF2) transcription factor family regulates the selective expression of genes involved in glucose transport, protein quality control, and phosphagen homeostasis. This study examined the role of MEF2A and MEF2C proteins as well as select downstream targets (glucose transporter-4, calreticulin, and muscle and brain creatine kinase isozymes) in 40% dehydration and 24 h anoxia exposure at the transcriptional, translational, and post-translational levels using qRT-PCR, immunoblotting, and subcellular localization.Mef2a/ctranscript levels remained constant during dehydration and anoxia. Total, cytoplasmic, and nuclear MEF2A/C and phospho-MEF2A/C protein levels remained constant during dehydration, whereas a decrease in total MEF2C levels was observed during rehydration. Total and phospho-MEF2A levels remained constant during anoxia, whereas total MEF2C levels decreased during 24 h anoxia and P-MEF2C levels increased during 4 h anoxia. In contrast, cytoplasmic MEF2A levels and nuclear phospho-MEF2A/C levels were upregulated during anoxia. MEF2 downstream targets remained constant during dehydration and anoxia, with the exception ofglut4which was upregulated during anoxia. These results suggest that the upregulated MEF2 response reported in wood frogs during freezing may in part stem from their cellular responses to surviving prolonged anoxia, rather than dehydration, leading to an increase in GLUT4 expression which may have an important role during anoxia survival.

scholarly journals Activating Hippo Pathway via Rassf1 by Ursolic Acid Suppresses the Tumorigenesis of Gastric Cancer

2019 ◽  
Vol 20 (19) ◽  
pp. 4709 ◽  
Author(s):  
Seong-Hun Kim ◽  
Hua Jin ◽  
Ruo Yu Meng ◽  
Da-Yeah Kim ◽  
Yu Chuan Liu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gastric Cancer ◽  
Cancer Cells ◽  
Ursolic Acid ◽  
Hippo Pathway ◽  
Dependent Manner ◽  
Gastric Cancer Cells ◽  
Protein Levels ◽  
Tumor Tissues ◽  
The Hippo Pathway

The Hippo pathway is often dysregulated in many carcinomas, which results in various stages of tumor progression. Ursolic acid (UA), a natural compound that exists in many herbal plants, is known to obstruct cancer progression and exerts anti-carcinogenic effect on a number of human cancers. In this study, we aimed to examine the biological mechanisms of action of UA through the Hippo pathway in gastric cancer cells. MTT assay showed a decreased viability of gastric cancer cells after treatment with UA. Following treatment with UA, colony numbers and the sizes of gastric cancer cells were significantly diminished and apoptosis was observed in SNU484 and SNU638 cells. The invasion and migration rates of gastric cancer cells were suppressed by UA in a dose-dependent manner. To further determine the gene expression patterns that are related to the effects of UA, a microarray analysis was performed. Gene ontology analysis revealed that several genes, such as the Hippo pathway upstream target gene, ras association domain family (RASSF1), and its downstream target genes (MST1, MST2, and LATS1) were significantly upregulated by UA, while the expression of YAP1 gene, together with oncogenes (FOXM1, KRAS, and BATF), were significantly decreased. Similar to the gene expression profiling results, the protein levels of RASSF1, MST1, MST2, LATS1, and p-YAP were increased, whereas those of CTGF were decreased by UA in gastric cancer cells. The p-YAP expression induced in gastric cancer cells by UA was reversed with RASSF1 silencing. In addition, the protein levels in the Hippo pathway were increased in the UA-treated xenograft tumor tissues as compared with that in the control tumor tissues; thus, UA significantly inhibited the tumorigenesis of gastric cancer in vivo in xenograft animals. Collectively, UA diminishes the proliferation and metastasis of gastric cancer via the regulation of Hippo pathway through Rassf1, which suggests that UA can be used as a potential chemopreventive and therapeutic agent for gastric cancer.

scholarly journals The NDR Kinase DBF-2 Is Involved in Regulation of Mitosis, Conidial Development, and Glycogen Metabolism in Neurospora crassa

2009 ◽  
Vol 9 (4) ◽  
pp. 502-513 ◽  
Author(s):  
Efrat Dvash ◽  
Galia Kra-Oz ◽  
Carmit Ziv ◽  
Shmuel Carmeli ◽  
Oded Yarden
Keyword(s):  
Cell Cycle ◽  
Neurospora Crassa ◽  
Filamentous Fungus ◽  
Hippo Pathway ◽  
Glycogen Metabolism ◽  
Content Type ◽  
Protein Levels ◽  
Carbon Nitrogen Ratio ◽  
Cdc 2 ◽  
The Hippo Pathway

ABSTRACT Neurospora crassa dbf-2 encodes an NDR (nuclear Dbf2-related) protein kinase, homologous to LATS1, a core component of the Hippo pathway. This pathway plays important roles in restraining cell proliferation and promoting apoptosis in differentiating cells. Here, we demonstrate that DBF-2 is involved in three fundamental processes in a filamentous fungus: cell cycle regulation, glycogen biosynthesis, and conidiation. DBF-2 is predominantly localized to the nucleus, and most (approximately 60%) dbf-2 null mutant nuclei are delayed in mitosis, indicating that DBF-2 activity is required for properly completing the cell cycle. The dbf-2 mutant exhibits reduced basal hyphal extension rates accompanied by a carbon/nitrogen ratio-dependent bursting of hyphal tips, vast glycogen leakage, defects in aerial hypha formation, and impairment of all three asexual conidiation pathways in N. crassa. Our findings also indicate that DBF-2 is essential for sexual reproduction in a filamentous fungus. Defects in other Hippo and glycogen metabolism pathway components (mob-1, ccr-4, mst-1, and gsk-3) share similar phenotypes such as mitotic delay and decreased CDC-2 (cell division cycle 2) protein levels, massive hyphal swellings, hyphal tip bursting, glycogen leakage, and impaired conidiation. We propose that DBF-2 functions as a link between Hippo and glycogen metabolism pathways.

DNA-binding mechanism of the Hippo pathway transcription factor TEAD4

Oncogene ◽  
2017 ◽  
Vol 36 (30) ◽  
pp. 4362-4369 ◽  
Author(s):  
Z Shi ◽  
F He ◽  
M Chen ◽  
L Hua ◽  
W Wang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Dna Binding ◽  
Hippo Pathway ◽  
Binding Mechanism ◽  
The Hippo Pathway

scholarly journals Liver Zonation in Health and Disease: Hypoxia and Hypoxia-Inducible Transcription Factors as Concert Masters

2019 ◽  
Vol 20 (9) ◽  
pp. 2347 ◽  
Author(s):  
Thomas Kietzmann
Keyword(s):  
Transcription Factors ◽  
Hedgehog Signaling ◽  
Hippo Pathway ◽  
Cell Types ◽  
Whole Body ◽  
Liver Zonation ◽  
Current Review ◽  
Health And Disease ◽  
The Hippo Pathway ◽  
Dynamic Interplay

The liver and its zonation contribute to whole body homeostasis. Acute and chronic, not always liver, diseases impair proper metabolic zonation. Various underlying pathways, such as β-catenin, hedgehog signaling, and the Hippo pathway, along with the physiologically occurring oxygen gradient, appear to be contributors. Interestingly, hypoxia and hypoxia-inducible transcription factors can orchestrate those pathways. In the current review, we connect novel findings of liver zonation in health and disease and provide a view about the dynamic interplay between these different pathways and cell-types to drive liver zonation and systemic homeostasis.

scholarly journals Nerfin-1 represses transcriptional output of Hippo signaling in cell competition

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Pengfei Guo ◽  
Chang-Hyun Lee ◽  
Huiyan Lei ◽  
Yonggang Zheng ◽  
Katiuska Daniela Pulgar Prieto ◽  
...  
Keyword(s):  
Dna Binding ◽  
Hippo Pathway ◽  
Ectopic Expression ◽  
Tissue Growth ◽  
Hippo Signaling ◽  
Dependent Manner ◽  
Cell Competition ◽  
Regulatory Mode ◽  
The Hippo Pathway ◽  
Transcriptional Output

The Hippo tumor suppressor pathway regulates tissue growth in Drosophila by restricting the activity of the transcriptional coactivator Yorkie (Yki), which normally complexes with the TEF/TEAD family DNA-binding transcription factor Scalloped (Sd) to drive the expression of growth-promoting genes. Given its pivotal role as a central hub in mediating the transcriptional output of Hippo signaling, there is great interest in understanding the molecular regulation of the Sd-Yki complex. In this study, we identify Nerfin-1 as a transcriptional repressor that antagonizes the activity of the Sd-Yki complex by binding to the TEA DNA-binding domain of Sd. Consistent with its biochemical function, ectopic expression of Nerfin-1 results in tissue undergrowth in an Sd-dependent manner. Conversely, loss of Nerfin-1 enhances the ability of winner cells to eliminate loser cells in multiple scenarios of cell competition. We further show that INSM1, the mammalian ortholog of Nerfin-1, plays a conserved role in repressing the activity of the TEAD-YAP complex. These findings reveal a novel regulatory mode converging on the transcriptional output of the Hippo pathway that may be exploited for modulating the YAP oncoprotein in cancer and regenerative medicine.

Biphasic increase in c-jun mRNA is required for induction of AP-1-mediated gene transcription: differential effects of muscarinic and thrombin receptor activation

1992 ◽  
Vol 12 (10) ◽  
pp. 4742-4750
Author(s):  
J Trejo ◽  
J C Chambard ◽  
M Karin ◽  
J H Brown
Keyword(s):  
Dna Binding ◽  
Gene Transcription ◽  
Time Course ◽  
Firefly Luciferase ◽  
Receptor Activation ◽  
Binding Activity ◽  
Protein Levels ◽  
Dna Binding Activity ◽  
Firefly Luciferase Gene ◽  
The Difference

Activation of either muscarinic cholinergic or thrombin receptors increases phosphoinositide turnover, Ca2+ mobilization, and redistribution of protein kinase C and induces rapid transient increases in c-fos mRNA and c-jun mRNA in 1321N1 cells. To determine whether the increases in c-fos and c-jun mRNA induced by carbachol and thrombin are sufficient to stimulate AP-1-mediated transactivation, 1321N1 cells were transfected with a reporter carrying two copies of the tetradecanoyl phorbol acetate response element and the firefly luciferase gene. Thrombin was significantly more effective than carbachol at stimulating AP-1-mediated transactivation. To identify the factors underlying the difference in AP-1 activity induced by carbachol and thrombin, members of the fos and jun families which encode components of AP-1 were examined. Carbachol and thrombin have similar effects on expression of c-fos, fosB, fra-2, junB, and junD, both acutely and over a 24-h time course. However, whereas carbachol leads only to transient induction of c-jun (maximal at 0.5 h), thrombin induces a biphasic increase in c-jun mRNA--an initial peak at 0.5 h and a second, more-prolonged increase at 12 h. Thrombin but not carbachol also induces a late increase in fra-1 mRNA, which peaks at 12 h. The secondary increase in c-jun mRNA is associated with marked increases in c-Jun protein levels and AP-1 DNA-binding activity. The late induction of c-jun and fra-1 mRNA can be prevented by adding the antagonist hirudin 30 min after thrombin, which results in loss of thrombin-stimulated increases in c-Jun protein, AP-1 DNA-binding activity, and AP-1-mediated transactivation. These findings suggest that rapid and transient conduction of c-fos and c-jun mRNA is insufficient to induce prominent changes in gene transcription, while the sustained increase in c-jun mRNA and perhaps the late induction of fra-1 mRNA are required for generation of AP-1 DNA-binding activity and transactivation through AP-1.

A cell-based assay to screen stimulators of the Hippo pathway reveals the inhibitory effect of dobutamine on the YAP-dependent gene transcription

2011 ◽  
Vol 150 (2) ◽  
pp. 199-208 ◽  
Author(s):  
Y. Bao ◽  
K. Nakagawa ◽  
Z. Yang ◽  
M. Ikeda ◽  
K. Withanage ◽  
...  
Keyword(s):  
Gene Transcription ◽  
Hippo Pathway ◽  
Inhibitory Effect ◽  
A Cell ◽  
The Hippo Pathway

Metabolic responses to dehydration by liver of the wood frog, Rana sylvatica

1994 ◽  
Vol 72 (8) ◽  
pp. 1420-1425 ◽  
Author(s):  
Thomas A. Churchill ◽  
Kenneth B. Storey
Keyword(s):  
Total Body Water ◽  
Energy Charge ◽  
Rana Sylvatica ◽  
Body Water ◽  
Whole Body ◽  
Metabolic Responses ◽  
Wood Frogs ◽  
Form Analysis ◽  
Glucose Synthesis ◽  
Total Body

The metabolic responses by the liver to the evaporative loss of up to 60% of total body water were quantified in spring-collected wood frogs, Rana sylvatica, a freeze-tolerant species. Dehydration stimulated rapid hyperglycemia, liver glucose levels rising 3.8-fold to 90 nmol/mg protein (9.9 μmol/g wet mass) by the time that 10% of total body water had been lost. Glucose accumulation occurred at the expense of liver glycogen reserves, which fell over the course of dehydration, and was supported by a 5.8-fold increase in the activity of glycogen phosphorylase a in the liver, made up of increases in both the total phosphorylase activity expressed and the percentage of the enzyme in the active form. Analysis of changes in the levels of glycolytic intermediates in the liver over the course of dehydration showed sharp increases in glucose-6-phosphate and fructose-6-phosphate during the period of active glucose synthesis but no change in the levels of fructose-1,6-bisphosphate or triose phosphates. This indicated that an inhibitory block on glycolysis at the phosphofructokinase reaction helped to promote the diversion of glycogenolysis into glucose export. When water loss exceeded 10%, cellular energetics were affected; ATP levels fell progressively between 25 and 60% dehydration, but a concomitant drop in the total adenylate pool held the energy charge stable at 0.7–0.8 up to 35% dehydration. At extreme dehydration (50 and 60%), metabolic indicators of hypoxia stress appeared in the liver: lactate accumulated and the energy charge fell. The data show that a primary response to whole-body dehydration in wood frogs is the activation of liver glucose synthesis and this suggests that the production of glucose as a cryoprotectant during freezing in this species is probably derived from a pre-existing amphibian volume-regulatory response to dehydration.

scholarly journals Prostate-Derived ETS Factor (PDEF) Regulates Yes Associated Protein 1 (YAP1) in Prostate Cancer Cells: A Potential Cross-Talk between PDEF and Hippo Signaling

2019 ◽  
Author(s):  
Praveen Kumar Jaiswal ◽  
Suman Mohajan ◽  
Sweaty Koul ◽  
Fengtian Wang ◽  
Runhua Shi ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Progression ◽  
Cross Talk ◽  
Hippo Pathway ◽  
Critical Role ◽  
Prostate Cancer Progression ◽  
Normal Prostate ◽  
Protein Levels ◽  
Pc3 Cells ◽  
The Hippo Pathway

PDEF is expressed in luminal epithelial cells of the prostate gland and associates with luminal phenotype. Hippo pathway regulates cell growth/proliferation, cellular homeostasis, and organ development by modulating phosphorylation of its downstream effectors. In previous studies, we observed decreased levels of PDEF during prostate cancer progression. In the present studies, we evaluated the effects of PDEF on total and phospho (Ser-127)YAP1 protein(a downstream effector of the Hippo pathway) levels in PC3 cells, a line of castrate resistant prostate cancer. We observed that the expression of PDEF in PC3 cells resulted in increased increased phospho(Ser127) -YAP1 protein levels. Our immunofluorescence analysis for YAP1 revealed an increased cytoplasmic/nuclear ratio of YAP1 in PDEF-PC3 cells as compared to VC-PC3 cells, suggesting PDEF may play a critical role in modulating YAP1 phosphorylation, and by extension in the regulation of the Hippo pathway. We also observed a decrease in YAP1 protein levels in prostate cancer tissues as compared to normal prostate tissues. Our analysis of multiple publicly available clinical cohorts revealed a gradual decrease in YAP1 mRNA expression during prostate cancer progression and metastasis. This decrease was similar to the decrease in PDEF levels which we reported earlier. In addition we observed further decreased in PDEF and YAP1 expression in Neuro-Endocrine Prostate Cancer (NEPC), and a direct correlation between PDEF and YAP1 expression. To the best of our knowledge, these results provide the first demonstration of modulation of YAP1 by PDEF in any system and suggest a cross-talk between PDEF and the Hippo pathway.

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