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.

scholarly journals Therapeutic Application of Brain-Specific Angiogenesis Inhibitor 1 for Cancer Therapy

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3562
Author(s):  
Mitra Nair ◽  
Chelsea Bolyard ◽  
Tae Jin Lee ◽  
Balveen Kaur ◽  
Ji Young Yoo
Keyword(s):  
Angiogenesis Inhibitor ◽  
Suppressor Gene ◽  
Chemotherapeutic Agents ◽  
Tumor Models ◽  
In Vivo Models ◽  
Herpes Simplex Viruses ◽  
Multiple Tumor ◽  
And Function

Brain-specific angiogenesis inhibitor 1 (BAI1/ADGRB1) is an adhesion G protein-coupled receptor that has been found to play key roles in phagocytosis, inflammation, synaptogenesis, the inhibition of angiogenesis, and myoblast fusion. As the name suggests, it is primarily expressed in the brain, with a high expression in the normal adult and developing brain. Additionally, its expression is reduced in brain cancers, such as glioblastoma (GBM) and peripheral cancers, suggesting that BAI1 is a tumor suppressor gene. Several investigators have demonstrated that the restoration of BAI1 expression in cancer cells results in reduced tumor growth and angiogenesis. Its expression has also been shown to be inversely correlated with tumor progression, neovascularization, and peri-tumoral brain edema. One method of restoring BAI1 expression is by using oncolytic virus (OV) therapy, a strategy which has been tested in various tumor models. Oncolytic herpes simplex viruses engineered to express the secreted fragment of BAI1, called Vasculostatin (Vstat120), have shown potent anti-tumor and anti-angiogenic effects in multiple tumor models. Combining Vstat120-expressing oHSVs with other chemotherapeutic agents has also shown to increase the overall anti-tumor efficacy in both in vitro and in vivo models. In the current review, we describe the structure and function of BAI1 and summarize its application in the context of cancer treatment.

scholarly journals Reading and Function of a Histone Code Involved in Targeting Corepressor Complexes for Repression

2005 ◽  
Vol 25 (1) ◽  
pp. 324-335 ◽  
Author(s):  
Ho-Geun Yoon ◽  
Youngsok Choi ◽  
Philip A. Cole ◽  
Jiemin Wong
Keyword(s):  
Transcriptional Activation ◽  
Transcriptional Repression ◽  
Hormone Receptors ◽  
Critical Role ◽  
Pericentric Heterochromatin ◽  
Histone Code ◽  
Stable Association ◽  
And Function

ABSTRACT A central question in histone code theory is how various codes are recognized and utilized in vivo. Here we show that TBL1 and TBLR1, two WD-40 repeat proteins in the corepressor SMRT/N-CoR complexes, are functionally redundant and essential for transcriptional repression by unliganded thyroid hormone receptors (TR) but not essential for transcriptional activation by liganded TR. TBL1 and TBLR1 bind preferentially to hypoacetylated histones H2B and H4 in vitro and have a critical role in targeting the corepressor complexes to chromatin in vivo. We show that targeting SMRT/N-CoR complexes to the deiodinase 1 gene (D1) requires at least two interactions, one between unliganded TR and SMRT/N-CoR and the other between TBL1/TBLR1 and hypoacetylated histones. Neither interaction alone is sufficient for the stable association of the corepressor complexes with the D1 promoter. Our data support a feed-forward working model in which deacetylation exerted by initial unstable recruitment of SMRT/N-CoR complexes via their interaction with unliganded TR generates a histone code that serves to stabilize their own recruitment. Similarly, we find that targeting of the Sin3 complex to pericentric heterochromatin may also follow this model. Our studies provide an in vivo example that a histone code is not read independently but is recognized in the context of other interactions.

scholarly journals Biophysical studies of protein misfolding and aggregation in in vivo models of Alzheimer's and Parkinson's diseases

2020 ◽  
Vol 53 ◽  
Author(s):  
Tessa Sinnige ◽  
Karen Stroobants ◽  
Christopher M. Dobson ◽  
Michele Vendruscolo
Keyword(s):  
Protein Misfolding ◽  
Molecular Mechanisms ◽  
Amyloid Β ◽  
Therapeutic Interventions ◽  
In Vivo Models ◽  
Disease Modifying Drugs ◽  
Parkinson’S Diseases ◽  
Protein Misfolding And Aggregation

Abstract Neurodegenerative disorders, including Alzheimer's (AD) and Parkinson's diseases (PD), are characterised by the formation of aberrant assemblies of misfolded proteins. The discovery of disease-modifying drugs for these disorders is challenging, in part because we still have a limited understanding of their molecular origins. In this review, we discuss how biophysical approaches can help explain the formation of the aberrant conformational states of proteins whose neurotoxic effects underlie these diseases. We discuss in particular models based on the transgenic expression of amyloid-β (Aβ) and tau in AD, and α-synuclein in PD. Because biophysical methods have enabled an accurate quantification and a detailed understanding of the molecular mechanisms underlying protein misfolding and aggregation in vitro, we expect that the further development of these methods to probe directly the corresponding mechanisms in vivo will open effective routes for diagnostic and therapeutic interventions.

scholarly journals Advanced Resistance Studies Identify Two Discrete Mechanisms in Staphylococcus aureus to Overcome Antibacterial Compounds that Target Biotin Protein Ligase

Antibiotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 165 ◽  
Author(s):  
Andrew J. Hayes ◽  
Jiulia Satiaputra ◽  
Louise M. Sternicki ◽  
Ashleigh S. Paparella ◽  
Zikai Feng ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Transcriptional Repression ◽  
Molecular Mechanisms ◽  
Resistance Mechanism ◽  
Resistance Mechanisms ◽  
Resistance Rate ◽  
Biotin Protein Ligase ◽  
Essential Enzyme

Biotin protein ligase (BPL) inhibitors are a novel class of antibacterial that target clinically important methicillin-resistant Staphylococcus aureus (S. aureus). In S. aureus, BPL is a bifunctional protein responsible for enzymatic biotinylation of two biotin-dependent enzymes, as well as serving as a transcriptional repressor that controls biotin synthesis and import. In this report, we investigate the mechanisms of action and resistance for a potent anti-BPL, an antibacterial compound, biotinyl-acylsulfamide adenosine (BASA). We show that BASA acts by both inhibiting the enzymatic activity of BPL in vitro, as well as functioning as a transcription co-repressor. A low spontaneous resistance rate was measured for the compound (<10−9) and whole-genome sequencing of strains evolved during serial passaging in the presence of BASA identified two discrete resistance mechanisms. In the first, deletion of the biotin-dependent enzyme pyruvate carboxylase is proposed to prioritize the utilization of bioavailable biotin for the essential enzyme acetyl-CoA carboxylase. In the second, a D200E missense mutation in BPL reduced DNA binding in vitro and transcriptional repression in vivo. We propose that this second resistance mechanism promotes bioavailability of biotin by derepressing its synthesis and import, such that free biotin may outcompete the inhibitor for binding BPL. This study provides new insights into the molecular mechanisms governing antibacterial activity and resistance of BPL inhibitors in S. aureus.

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.

Bioactive Compounds from Seaweed with Anti-Leukemic Activity: A Mini-Review on Carotenoids and Phlorotannins

2020 ◽  
Vol 20 (1) ◽  
pp. 39-53 ◽  
Author(s):  
Tânia P. Almeida ◽  
Alice A. Ramos ◽  
Joana Ferreira ◽  
Amaya Azqueta ◽  
Eduardo Rocha
Keyword(s):  
Drug Resistance ◽  
Bioactive Compounds ◽  
Myeloid Leukemia ◽  
Molecular Mechanisms ◽  
Kinase Inhibitors ◽  
First Line ◽  
In Vivo Models ◽  
Few Data

: Chronic Myeloid Leukemia (CML) represents 15-20% of all new cases of leukemia and is characterized by an uncontrolled proliferation of abnormal myeloid cells. Currently, the first-line of treatment involves Tyrosine Kinase Inhibitors (TKIs), which specifically inhibits the activity of the fusion protein BCR-ABL. However, resistance, mainly due to mutations, can occur. In the attempt to find more effective and less toxic therapies, several approaches are taken into consideration such as research of new anti-leukemic drugs and “combination chemotherapy” where different drugs that act by different mechanisms are used. Here, we reviewed the molecular mechanisms of CML, the main mechanisms of drug resistance and current strategies to enhance the therapeutic effect of TKIs in CML. Despite major advances in CML treatment, new, more potent anticancer drugs and with fewer side effects are needed. Marine organisms, and particularly seaweed, have a high diversity of bioactive compounds with some of them having anticancer activity in several in vitro and in vivo models. The state-of-art suggests that their use during cancer treatment may improve the outcome. We reviewed here the yet few data supporting anti-leukemic activity of some carotenoids and phlorotannins in some leukemia models. Also, strategies to overcome drug resistance are discussed, particularly the combination of conventional drugs with natural compounds.

scholarly journals The quinoxaline di-N-oxide DCQ blocks breast cancer metastasis in vitro and in vivo by targeting the hypoxia inducible factor-1 pathway

2014 ◽  
Vol 13 (1) ◽  
pp. 12 ◽  
Author(s):  
Khaled Ghattass ◽  
Sally El-Sitt ◽  
Kazem Zibara ◽  
Saide Rayes ◽  
Makhluf J Haddadin ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Metastasis ◽  
Hypoxia Inducible Factor ◽  
Breast Cancer Metastasis ◽  
Hypoxia Inducible Factor 1

scholarly journals Dissecting Breast Cancer Circulating Tumor Cells Competence via Modelling Metastasis in Zebrafish

2021 ◽  
Vol 22 (17) ◽  
pp. 9279
Author(s):  
Inés Martínez-Pena ◽  
Pablo Hurtado ◽  
Nuria Carmona-Ule ◽  
Carmen Abuín ◽  
Ana Belén Dávila-Ibáñez ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Cells ◽  
Circulating Tumor Cells ◽  
Molecular Mechanisms ◽  
Zebrafish Embryo ◽  
Cancer Metastasis ◽  
Fluid Shear Stress ◽  
In Vivo Models

Background: Cancer metastasis is a deathly process, and a better understanding of the different steps is needed. The shedding of circulating tumor cells (CTCs) and CTC-cluster from the primary tumor, its survival in circulation, and homing are key events of the metastasis cascade. In vitro models of CTCs and in vivo models of metastasis represent an excellent opportunity to delve into the behavior of metastatic cells, to gain understanding on how secondary tumors appear. Methods: Using the zebrafish embryo, in combination with the mouse and in vitro assays, as an in vivo model of the spatiotemporal development of metastases, we study the metastatic competency of breast cancer CTCs and CTC-clusters and the molecular mechanisms. Results: CTC-clusters disseminated at a lower frequency than single CTCs in the zebrafish and showed a reduced capacity to invade. A temporal follow-up of the behavior of disseminated CTCs showed a higher survival and proliferation capacity of CTC-clusters, supported by their increased resistance to fluid shear stress. These data were corroborated in mouse studies. In addition, a differential gene signature was observed, with CTC-clusters upregulating cell cycle and stemness related genes. Conclusions: The zebrafish embryo is a valuable model system to understand the biology of breast cancer CTCs and CTC-clusters.

scholarly journals Molecular Docking and Drug-Likeness for the Identification of Inhibitory Action of Acetogenins from Annona muricata as Potential Anticancer against Hypoxia Inducible Factor 1 Alpha

2018 ◽  
Vol 11 (3) ◽  
pp. 1301-1307
Author(s):  
Supri I. Handayani ◽  
Rahmiati Rahmiati ◽  
Lisnawati Rahmadi ◽  
Rosmalena Rosmalena ◽  
Vivitri D. Prasasty
Keyword(s):  
Molecular Docking ◽  
Hypoxia Inducible Factor ◽  
Binding Energies ◽  
Binding Modes ◽  
Annona Muricata ◽  
Chemical Structures ◽  
Hypoxia Inducible Factor 1 ◽  
Human Cancers

Hypoxia inducible factor 1 alpha (HIF-1α) regulates cell growth and differentiation which is implicated in human cancers. HIF-1α activates its cascade carcinogenesis mechanism in cancer cells. It is well-understood that signaling is initiated by HIF-1α receptor. Overexpression of HIF-1α is associated with several different human cancers, including breast cancer, lung cancer and colon cancer. Thus, HIF-1α becomes potential target of therapeutic approach in developing HIF-1α inhibitors. The aim of this research is to investigate potential inhibitors which are known as Acetogenins (AGEs) isolated from Annona muricata against HIF-1α. In order to achieve this goal, chemical structures of all compounds were retrieved from PubChem database. Molecular docking was performed by AutoDock Vina program and the resulting binding modes were analyzed with AutoDock Tools program. Among all the compounds, murihexocin A showed the best binding modes compared to other two inhibitors based on the lowest binding energies (LBE = -7.9 kcal/mol) as high as gefitinib. This was indicating that murihexocin A has favorable interaction with the essential amino acid residues at catalytic site of HIF-1α. Drug-likeness calculation of AGEs were also performed. These in silico results could be beneficial as a compound model for further studies in-vitro and in-vivo.

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