scholarly journals p300 relieves p53-evoked transcriptional repression of hypoxia-inducible factor-1 (HIF-1)

2004 ◽  
Vol 380 (1) ◽  
pp. 289-295 ◽  
Author(s):  
Tobias SCHMID ◽  
Jie ZHOU ◽  
Roman KÖHL ◽  
Bernhard BRÜNE
Keyword(s):  
Transcription Factor ◽  
Transcriptional Repression ◽  
Hypoxia Inducible Factor ◽  
Severe Hypoxia ◽  
Metabolic Adaptation ◽  
Adaptation To Hypoxia ◽  
P53 Expression ◽  
Hypoxia Inducible Factor 1 ◽  
Reporter Activity

HIF-1 (hypoxia-inducible factor-1), a heterodimeric transcription factor comprising HIF-1α and HIF-1β subunits, serves as a key regulator of metabolic adaptation to hypoxia. HIF-1 activity largely increases during hypoxia by attenuating pVHL (von Hippel–Lindau protein)-dependent ubiquitination and subsequent 26 S-proteasomal degradation of HIF-1α. Besides HIF-1, the transcription factor and tumour suppressor p53 accumulates and is activated under conditions of prolonged/severe hypoxia. Recently, the interaction between p53 and HIF-1α was reported to evoke HIF-1α degradation. Destruction of HIF-1α by p53 was corroborated in the present study by using pVHL-deficient RCC4 (renal carcinoma) cells, supporting the notion of a pVHL-independent degradation process. In addition, low p53 expression repressed HIF-1 transactivation without affecting HIF-1α protein amount. Establishing that p53-evoked inhibition of HIF-1 reporter activity was relieved upon co-transfection of p300 suggested competition between p53 and HIF-1 for limiting amounts of the shared co-activator p300. This assumption was confirmed by showing competitive binding of in vitro transcription/translation-generated p53 and HIF-1α to the CH1 domain of p300 in vitro. We conclude that low p53 expression attenuates HIF-1 transactivation by competing for p300, whereas high p53 expression destroys the HIF-1α protein and thereby eliminates HIF-1 reporter activity. Thus once p53 becomes activated under conditions of severe hypoxia/anoxia, it contributes to terminating HIF-1 responses.

scholarly journals HIF-1–dependent repression of equilibrative nucleoside transporter (ENT) in hypoxia

2005 ◽  
Vol 202 (11) ◽  
pp. 1493-1505 ◽  
Author(s):  
Holger K. Eltzschig ◽  
Parween Abdulla ◽  
Edgar Hoffman ◽  
Kathryn E. Hamilton ◽  
Dionne Daniels ◽  
...  
Keyword(s):  
Transcriptional Repression ◽  
Molecular Mechanisms ◽  
Hypoxia Inducible Factor ◽  
Nucleoside Transporter ◽  
In Vivo Models ◽  
Equilibrative Nucleoside Transporter ◽  
Hypoxia Inducible Factor 1 ◽  
And Function

Extracellular adenosine (Ado) has been implicated as central signaling molecule during conditions of limited oxygen availability (hypoxia), regulating physiologic outcomes as diverse as vascular leak, leukocyte activation, and accumulation. Presently, the molecular mechanisms that elevate extracellular Ado during hypoxia are unclear. In the present study, we pursued the hypothesis that diminished uptake of Ado effectively enhances extracellular Ado signaling. Initial studies indicated that the half-life of Ado was increased by as much as fivefold after exposure of endothelia to hypoxia. Examination of expressional levels of the equilibrative nucleoside transporter (ENT)1 and ENT2 revealed a transcriptionally dependent decrease in mRNA, protein, and function in endothelia and epithelia. Examination of the ENT1 promoter identified a hypoxia inducible factor 1 (HIF-1)–dependent repression of ENT1 during hypoxia. Using in vitro and in vivo models of Ado signaling, we revealed that decreased Ado uptake promotes vascular barrier and dampens neutrophil tissue accumulation during hypoxia. Moreover, epithelial Hif1α mutant animals displayed increased epithelial ENT1 expression. Together, these results identify transcriptional repression of ENT as an innate mechanism to elevate extracellular Ado during hypoxia.

Persisting mild hypothermia suppresses hypoxia-inducible factor-1α protein synthesis and hypoxia-inducible factor-1-mediated gene expression

2010 ◽  
Vol 298 (3) ◽  
pp. R661-R671 ◽  
Author(s):  
Tomoharu Tanaka ◽  
Takuhiko Wakamatsu ◽  
Hiroki Daijo ◽  
Seiko Oda ◽  
Shinichi Kai ◽  
...  
Keyword(s):  
Gene Expression ◽  
Low Temperature ◽  
Hypoxia Inducible Factor ◽  
The Body ◽  
The Other ◽  
Adaptation To Hypoxia ◽  
Hypoxia Inducible Factor 1 ◽  
Other Hand

The transcription factor hypoxia-inducible factor-1 (HIF-1) plays an essential role in regulating gene expression in response to hypoxia-ischemia. Ischemia causes the tissue not only to be hypoxic but also to be hypothermic because of the hypoperfusion under certain circumstances. On the other hand, the induced hypothermia is one of the most common therapeutic modalities to extend tolerance to hypoxia. Although hypoxia elicits a variety of cellular and systemic responses at different organizational levels in the body, little is known about how hypoxia-induced responses are affected by low temperature. We examined the influence of mild hypothermic conditions (28–32°C) on HIF-1 in both in vitro and in vivo settings. In vitro experiments adopting cultured cells elucidated that hypoxia-induced HIF-1 activation was resistant to 4-h exposure to the low temperature. In contrast, exposure to the low temperature as long as 24 h suppressed HIF-1 activation and the subsequent upregulation of HIF-1 target genes such as VEGF or GLUT-1. HIF-1α protein stability in the cell was not affected by hypothermic treatment. Furthermore, intracellular ATP content was reduced under 1% O2 conditions but was not largely affected by hypothermic treatment. The evidence indicates that reduction of oxygen consumption is not largely involved in suppression of HIF-1. In addition, we demonstrated that HIF-1 DNA-binding activity and HIF-1-dependent gene expressions induced under 10% O2 atmosphere in mouse brain were not influenced by treatment under 3-h hypothermic temperature but were inhibited under 5-h treatment. On the other hand, we indicated that warming ischemic legs of mice for 24 h preserved HIF-1 activity. In this report we describe for the first time that persisting low temperature significantly reduced HIF-1α neosynthesis under hypoxic conditions, leading to a decrease in gene expression for adaptation to hypoxia in both in vitro and in vivo settings.

scholarly journals Hypoxia-Inducible Factor 1 Is an Inductor of Transcription Factor Activating Protein 2 Epsilon Expression during Chondrogenic Differentiation

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Stephan Niebler ◽  
Peter Angele ◽  
Richard Kujat ◽  
Anja K. Bosserhoff
Keyword(s):  
Transcription Factor ◽  
Chondrogenic Differentiation ◽  
Mrna Level ◽  
Marker Gene ◽  
Hypoxia Inducible Factor ◽  
Oxygen Deprivation ◽  
Hypoxia Inducible Factor 1 ◽  
Hypoxia Marker

The transcription factor AP-2ε(activating enhancer-binding protein epsilon) is expressed in cartilage of humans and mice. However, knowledge about regulatory mechanisms influencing AP-2εexpression is limited. Using quantitative real time PCR, we detected a significant increase in AP-2εmRNA expression comparing initial and late stages of chondrogenic differentiation processesin vitroandin vivo. Interestingly, in these samples the expression pattern of the prominent hypoxia marker geneangiopoietin-like 4 (Angptl4)strongly correlated with that ofAP-2εsuggesting that hypoxia might represent an external regulator of AP-2εexpression in mammals. In order to show this, experiments directly targeting the activity of hypoxia-inducible factor-1 (HIF1), the complex mediating responses to oxygen deprivation, were performed. While the HIF1-activating compounds 2,2′-dipyridyl and desferrioxamine resulted in significantly enhanced mRNA concentration of AP-2ε, siRNA against HIF1αled to a significantly reduced expression rate ofAP-2ε. Additionally, we detected a significant upregulation of the AP-2εmRNA level after oxygen deprivation. In sum, these different experimental approaches revealed a novel role for the HIF1 complex in the regulation of theAP-2εgene in cartilaginous cells and underlined the important role of hypoxia as an important external regulatory stimulus during chondrogenic differentiation modulating the expression of downstream transcription factors.

scholarly journals Tumor Necrosis Factor-α Causes Accumulation of a Ubiquitinated Form of Hypoxia Inducible Factor-1α through a Nuclear Factor-κB-Dependent Pathway

2003 ◽  
Vol 14 (6) ◽  
pp. 2216-2225 ◽  
Author(s):  
Jie Zhou ◽  
Tobias Schmid ◽  
Bernhard Brüne
Keyword(s):  
Hypoxia Inducible Factor ◽  
Nuclear Factor Κb ◽  
Metabolic Adaptation ◽  
Adaptation To Hypoxia ◽  
Nuclear Factor ◽  
Human Embryonic Kidney Cells ◽  
Von Hippel Lindau ◽  
Hypoxia Inducible Factor 1 ◽  
Tnf Α ◽  
Factor Α

Hypoxia-inducible factor-1 (HIF-1) is a regulator of metabolic adaptation to hypoxia. It is now appreciated that HIF-1α accumulation is achieved under normoxic conditions by various factors, such as TNF-α. Here, it was our intention to gain insight into the signaling mechanisms used by TNF-α to stimulate HIF-1α. In tubular LLC-PK1or human embryonic kidney cells, TNF-α induced accumulation of HIF-1α protein but not HIF-1α mRNA. Blocking nuclear factor (NF)-κB with sulfasalazine or expression of an IκB superrepressor attenuated HIF-1α accumulation, whereas transfection of active p50/p65-NF-κB subunits mimicked a TNF-α response. Experiments with actinomycin D and cycloheximide also pointed to a transcriptional and translational process in facilitating the TNF-α response. Interestingly, and in contrast to established hypoxic signaling concepts, TNF-α elicited HIF-1α accumulation in a ubiquitinated form that still bound the von Hippel-Lindau (pVHL) protein. These data indicate that HIF-1α accumulation by TNF-α demands the NF-κB pathway, preserves ubiquitination of HIF-1α, and allows the HIF-1α-pVHL interaction.

Anticancer Activity of Natural Flavonoids: Inhibition of HIF-1α Signaling Pathway

2020 ◽  
Vol 23 (26) ◽  
pp. 2945-2959 ◽  
Author(s):  
Xiangping Deng ◽  
Yijiao Peng ◽  
Jingduo Zhao ◽  
Xiaoyong Lei ◽  
Xing Zheng ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Secondary Metabolites ◽  
Anticancer Agents ◽  
Hypoxia Inducible Factor ◽  
Tumor Hypoxia ◽  
Pharmacological Activities ◽  
Hypoxia Inducible Factor 1 ◽  
The Past ◽  
Low Toxicity ◽  
Tumor Blood Vessels

Rapid tumor growth is dependent on the capability of tumor blood vessels and glycolysis to provide oxygen and nutrients. Tumor hypoxia is a common characteristic of many solid tumors, and it essentially happens when the growth of the tumor exceeds the concomitant angiogenesis. Hypoxia-inducible factor 1 (HIF-1) as the critical transcription factor in hypoxia regulation is activated to adapt to this hypoxia situation. Flavonoids, widely distributed in plants, comprise many polyphenolic secondary metabolites, possessing broadspectrum pharmacological activities, including their potentiality as anticancer agents. Due to their low toxicity, intense efforts have been made for investigating natural flavonoids and their derivatives that can be used as HIF-1α inhibitors for cancer therapy during the past few decades. In this review, we sum up the findings concerning the inhibition of HIF-1α by natural flavonoids in the last few years and propose the idea of designing tumor vascular and glycolytic multi-target inhibitors with HIF-1α as one of the targets.

Apatinib Inhibits Angiogenesis in Intrahepatic Cholangiocarcinoma by Regulating the Vascular Endothelial Growth Factor Receptor-2/Signal Transducer and Activator of Transcription Factor 3/Hypoxia Inducible Factor 1 Subunit Alpha Signaling Axis

Pharmacology ◽  
2021 ◽  
pp. 1-11
Author(s):  
Man-Ping Huang ◽  
Shan-Zhi Gu ◽  
Bin Huang ◽  
Guo-Wen Li ◽  
Zheng-Ping Xiong ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Transcription Factor ◽  
Growth Factor ◽  
Intrahepatic Cholangiocarcinoma ◽  
Hypoxia Inducible Factor ◽  
Growth Factor Receptor ◽  
Vascular Endothelial ◽  
Signal Transducer ◽  
Hypoxia Inducible Factor 1 ◽  
Endothelial Growth Factor

<b><i>Introduction:</i></b> Intrahepatic cholangiocarcinoma (ICC), which is difficult to diagnose and is usually fatal due to its late clinical presentation and a lack of effective treatment, has risen over the past decades but without much improvement in prognosis. <b><i>Objective:</i></b> The study aimed to investigate the role of apatinib that targets vascular endothelial growth factor receptor-2 (VEGFR2) in ICC. <b><i>Methods:</i></b> MTT assays, cell scratch assays, and tube formation assays were used to assess the effect of apatinib on human ICC cell line (HuCCT-1) and RBE cells proliferation, migration, and angiogenic capacity, respectively. Expression of vascular endothelial growth factor (VEGF), VEGFR2, signal transducer and activator of transcription factor 3 (STAT3), pSTAT3, and hypoxia inducible factor 1 subunit alpha (HIF-1α) pathway proteins was assessed using Western blotting and mRNA expression analysis in HuCCT-1 was performed using RT-qPCR assays. The pcDNA 3.1(-)-VEGFR2 and pcDNA 3.1(-)-HIF-1α were transfected into HuCCT-1 and RBE cells using Lipofectamine 2,000 to obtain overexpressed HuCCT-1 and RBE cells. <b><i>Results:</i></b> We found that apatinib-inhibited proliferation, migration, and angiogenesis of HuCCT-1 and RBE cells in vitro in a dose-dependent manner. We also proved that apatinib effectively inhibits angiogenesis in tumor cells by blocking the expression of VEGF and VEGFR2 in these cells. In addition, we demonstrated that apatinib regulates the expression of STAT3 phosphorylation by inhibiting VEGFR2. Finally, we showed that apatinib regulates ICC angiogenesis and HIF-1α/VEGF expression via STAT3. <b><i>Conclusions:</i></b> Based on the above findings, we conclude that apatinib inhibits HuCCT-1 and RBE cell proliferation, migration, and tumor angiogenesis by inhibiting the VEGFR2/STAT3/HIF-1α axis signaling pathway. Apatinib can be a promising drug for ICC-targeted molecular therapy.

scholarly journals Normoxic Tumour Extracellular Vesicles Modulate the Response of Hypoxic Cancer and Stromal Cells to Doxorubicin In Vitro

2020 ◽  
Vol 21 (17) ◽  
pp. 5951
Author(s):  
Laura Patras ◽  
Marcel H. A. M. Fens ◽  
Pieter Vader ◽  
Arjan Barendrecht ◽  
Alina Sesarman ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Extracellular Vesicles ◽  
Hypoxia Inducible Factor ◽  
B Cell Lymphoma ◽  
Tumour Microenvironment ◽  
Hypoxia Inducible Factor 1 ◽  
Apoptotic Protein ◽  
Donor Cells

Extracellular vesicles (EV) secreted in the tumour microenvironment (TME) are emerging as major antagonists of anticancer therapies by orchestrating the therapeutic outcome through altering the behaviour of recipient cells. Recent evidence suggested that chemotherapeutic drugs could be responsible for the EV-mediated tumour–stroma crosstalk associated with cancer cell drug resistance. Here, we investigated the capacity of tumour EV (TEV) secreted by normoxic and hypoxic (1% oxygen) C26 cancer cells after doxorubicin (DOX) treatment to alter the response of naïve C26 cells and RAW 264.7 macrophages to DOX. We observed that C26 cells were less responsive to DOX treatment under normoxia compared to hypoxia, and a minimally cytotoxic DOX concentration that mounted distinct effects on cell viability was selected for TEV harvesting. Homotypic and heterotypic pretreatment of naïve hypoxic cancer and macrophage-like cells with normoxic DOX-elicited TEV rendered these cells slightly less responsive to DOX treatment. The observed effects were associated with strong hypoxia-inducible factor 1-alpha (HIF-1α) induction and B-cell lymphoma–extra-large anti-apoptotic protein (Bcl-xL)-mediated anti-apoptotic response in normoxic DOX-treated TEV donor cells, being also tightly connected to the DOX-TEV-mediated HIF-1α induction, as well as Bcl-xL levels increasing in recipient cells. Altogether, our results could open new perspectives for investigating the role of chemotherapy-elicited TEV in the colorectal cancer TME and their modulatory actions on promoting drug resistance.

scholarly journals Inhibitor of DNA Binding 1 Is Induced during Kidney Ischemia-Reperfusion and Is Critical for the Induction of Hypoxia-Inducible Factor-1α

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Dan Wen ◽  
Yan-Fang Zou ◽  
Yao-Hui Gao ◽  
Qian Zhao ◽  
Yin-Yin Xie ◽  
...  
Keyword(s):  
Dna Binding ◽  
Ischemia Reperfusion ◽  
Hypoxia Inducible Factor ◽  
Kidney Injury ◽  
Mrna Levels ◽  
Hypoxia Inducible Factor 1 ◽  
Renal Tubular ◽  
Inhibitor Of Dna Binding

In this study, rat models of acute kidney injury (AKI) induced by renal ischemia-reperfusion (I/R) and HK-2 cell models of hypoxia-reoxygenation (H/R) were established to investigate the expression of inhibitor of DNA binding 1 (ID1) in AKI, and the regulation relationship between ID1 and hypoxia-inducible factor 1 alpha (HIF-1α). Through western blot, quantitative real-time PCR, immunohistochemistry, and other experiment methods, the induction of ID1 after renal I/R in vivo was observed, which was expressed mainly in renal tubular epithelial cells (TECs). ID1 expression was upregulated in in vitro H/R models at both the protein and mRNA levels. Via RNAi, it was found that ID1 induction was inhibited with silencing of HIF-1α. Moreover, the suppression of ID1 mRNA expression could lead to decreased expression and transcription of HIF-1αduring hypoxia and reoxygenation. In addition, it was demonstrated that both ID1 and HIF-1αcan regulate the transcription of twist. This study demonstrated that ID1 is induced in renal TECs during I/R and can regulate the transcription and expression of HIF-1α.

Activating transcription factor 2 increases transactivation and protein stability of hypoxia-inducible factor 1α in hepatocytes

2009 ◽  
Vol 424 (2) ◽  
pp. 285-296 ◽  
Author(s):  
Jeong Hae Choi ◽  
Hyun Kook Cho ◽  
Yung Hyun Choi ◽  
JaeHun Cheong
Keyword(s):  
Transcription Factor ◽  
Protein Stability ◽  
Gene Transcription ◽  
Hypoxia Inducible Factor ◽  
Protein Stabilization ◽  
Hypoxic Conditions ◽  
Tumour Suppressor Protein ◽  
Activating Transcription Factor

HIF-1 (hypoxia inducible factor 1) performs a crucial role in mediating the response to hypoxia. However, other transcription factors are also capable of regulating hypoxia-induced target-gene transcription. In a previous report, we demonstrated that the transcription factor ATF-2 (activating transcription factor 2) regulates hypoxia-induced gene transcription, along with HIF-1α. In the present study, we show that the protein stability of ATF-2 is induced by hypoxia and the hypoxia-mimic CoCl2 (cobalt chloride), and that ATF-2 induction enhances HIF-1α protein stability via direct protein interaction. The knockdown of ATF-2 using small interfering RNA and translation-inhibition experiments demonstrated that ATF-2 plays a key role in the maintenance of the expression level and transcriptional activity of HIF-1α. Furthermore, we determined that ATF-2 interacts directly with HIF-1α both in vivo and in vitro and competes with the tumour suppressor protein p53 for HIF-1α binding. Collectively, these results show that protein stabilization of ATF-2 under hypoxic conditions is required for the induction of the protein stability and transactivation activity of HIF-1α for efficient hypoxia-associated gene expression.

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