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Suresh MV, Aktay S, Yalamanchili G, Solanki S, Sathyarajan DT, Arnipalli MS, Pennathur S, Raghavendran K. Role of succinate in airway epithelial cell regulation following traumatic lung injury. JCI Insight 2023; 8:e166860. [PMID: 37737265 PMCID: PMC10561732 DOI: 10.1172/jci.insight.166860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 08/17/2023] [Indexed: 09/23/2023] Open
Abstract
Lung contusion and gastric aspiration (LC and GA) are major risk factors for developing acute respiratory distress following trauma. Hypoxia from lung injury is mainly regulated by hypoxia-inducible factor 1α (HIF-1α). Published data from our group indicate that HIF-1α regulation in airway epithelial cells (AEC) drives the acute inflammatory response following LC and GA. Metabolomic profiling and metabolic flux of Type II AEC following LC revealed marked increases in glycolytic and TCA intermediates in vivo and in vitro that were HIF-1α dependent. GLUT-1/4 expression was also increased in HIF-1α+/+ mice, suggesting that increased glucose entry may contribute to increased intermediates. Importantly, lactate incubation in vitro on Type II cells did not significantly increase the inflammatory byproduct IL-1β. Contrastingly, succinate had a direct proinflammatory effect on human small AEC by IL-1β generation in vitro. This effect was reversed by dimethylmalonate, suggesting an important role for succinate dehydrogenase in mediating HIF-1α effects. We confirmed the presence of the only known receptor for succinate binding, SUCNR1, on Type II AEC. These results support the hypothesis that succinate drives HIF-1α-mediated airway inflammation following LC. This is the first report to our knowledge of direct proinflammatory activation of succinate in nonimmune cells such as Type II AEC in direct lung injury models.
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Romero-Lopez M, Oria M, Ferrer-Marquez F, Varela MF, Lampe K, Watanabe-Chailland M, Martinez L, Peiro JL. Fetal lung hypoxia and energetic cell failure in the nitrofen-induced congenital diaphragmatic hernia rat model. Pediatr Surg Int 2023; 39:180. [PMID: 37055635 DOI: 10.1007/s00383-023-05452-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/03/2023] [Indexed: 04/15/2023]
Abstract
PURPOSE Congenital diaphragmatic hernia (CDH) pathogenesis is poorly understood. We hypothesize that fetal CDH lungs are chronically hypoxic because of lung hypoplasia and tissue compression, affecting the cell bioenergetics as a possible explanation for abnormal lung development. METHODS To investigate this theory, we conducted a study using the rat nitrofen model of CDH. We evaluated the bioenergetics status using H1 Nuclear magnetic resonance and studied the expression of enzymes involved in energy production, the hypoxia-inducible factor 1α, and the glucose transporter 1. RESULTS The nitrofen-exposed lungs have increased levels of hypoxia-inducible factor 1α and the main fetal glucose transporter, more evident in the CDH lungs. We also found imbalanced AMP:ATP and ADP:ATP ratios, and a depleted energy cellular charge. Subsequent transcription levels and protein expression of the enzymes involved in bioenergetics confirm the attempt to prevent the energy collapse with the increase in lactate dehydrogenase C, pyruvate dehydrogenase kinase 1 and 2, adenosine monophosphate deaminase, AMP-activated protein kinase, calcium/calmodulin-dependent protein kinase 2, and liver kinase B1, while decreasing ATP synthase. CONCLUSION Our study suggests that changes in energy production could play a role in CDH pathogenesis. If confirmed in other animal models and humans, this could lead to the development of novel therapies targeting the mitochondria to improve outcomes.
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Affiliation(s)
- Mar Romero-Lopez
- McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Marc Oria
- Division of Pediatric General and Thoracic Surgery, Center for Fetal and Placental Research, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, OH, 45229, USA
- Department of Surgery, College of Medicine, University of Cincinnati, Cincinnati, OH, 45267, USA
| | - Fernando Ferrer-Marquez
- Division of Pediatric General and Thoracic Surgery, Center for Fetal and Placental Research, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, OH, 45229, USA
- Division of Obstetrics and Gynecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Maria Florencia Varela
- Division of Pediatric General and Thoracic Surgery, Center for Fetal and Placental Research, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, OH, 45229, USA
| | - Kristin Lampe
- Division of Pediatric General and Thoracic Surgery, Center for Fetal and Placental Research, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, OH, 45229, USA
| | - Miki Watanabe-Chailland
- NMR-Based Metabolomics Core, Division of Pathology and Laboratory Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Leopoldo Martinez
- Servicio de Cirugía Pediátrica, Hospital la Paz, Instituto de Investigación La Paz (IdiPAZ), Madrid, Spain
| | - Jose L Peiro
- Division of Pediatric General and Thoracic Surgery, Center for Fetal and Placental Research, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, OH, 45229, USA.
- Department of Surgery, College of Medicine, University of Cincinnati, Cincinnati, OH, 45267, USA.
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Pamies D, Vujić T, Schvartz D, Boccard J, Repond C, Nunes C, Rudaz S, Sanchez JC, González-Ruiz V, Zurich MG. Digoxin Induces Human Astrocyte Reaction In Vitro. Mol Neurobiol 2023; 60:84-97. [PMID: 36223047 PMCID: PMC9758102 DOI: 10.1007/s12035-022-03057-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 09/21/2022] [Indexed: 12/30/2022]
Abstract
Astrocyte reaction is a complex cellular process involving astrocytes in response to various types of CNS injury and a marker of neurotoxicity. It has been abundantly studied in rodents but relatively poorly in human cells due to limited access to the brain. Astrocytes play important roles in cerebral energy metabolism and are also key players in neuroinflammation. Astroglial metabolic and inflammatory changes have been reported with age, leading to the hypothesis that mitochondrial metabolism and inflammatory responses are interconnected. However, the relationship between energy metabolism and astrocyte reactivity in the context of neurotoxicity is not known. We hypothesized that changes in energy metabolism of astrocytes will be coupled to their activation by xenobiotics. Astrocyte reaction and associated energy metabolic changes were assessed by immunostaining, gene expression, proteomics, metabolomics, and extracellular flux analyses after 24 h of exposure of human ReN-derived astrocytes to digoxin (1-10 µM) or TNFα (30 ng/ml) used as a positive control. Strong astrocytic reaction was observed, accompanied by increased glycolysis at low concentrations of digoxin (0.1 and 0.5 µM) and after TNFα exposure, suggesting that increased glycolysis may be a common feature of reactive astrocytes, independent of the triggering molecule. In conclusion, whether astrocyte activation is triggered by cytokines or a xenobiotic, it is strongly tied to energy metabolism in human ReN-derived astrocytes. Increased glycolysis might be considered as an endpoint to detect astrocyte activation by potentially neurotoxic compounds in vitro. Finally, ReN-derived astrocytes may help to decipher mechanisms of neurotoxicity in ascertaining the ability of chemicals to directly target astrocytes.
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Affiliation(s)
- David Pamies
- Department of Biological Sciences, University of Lausanne, Lausanne, Switzerland ,School of Pharmaceutical Sciences and Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland
| | - Tatjana Vujić
- Swiss Centre for Applied Human Toxicology (SCAHT), Basel, Switzerland ,School of Pharmaceutical Sciences and Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland
| | - Domitille Schvartz
- Swiss Centre for Applied Human Toxicology (SCAHT), Basel, Switzerland ,School of Pharmaceutical Sciences and Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland
| | - Julien Boccard
- Translational Biomarker Group, Department of Medicine, University of Geneva, Geneva, Switzerland ,School of Pharmaceutical Sciences and Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland
| | - Cendrine Repond
- Department of Biological Sciences, University of Lausanne, Lausanne, Switzerland
| | - Carolina Nunes
- Department of Biological Sciences, University of Lausanne, Lausanne, Switzerland ,School of Pharmaceutical Sciences and Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland
| | - Serge Rudaz
- Translational Biomarker Group, Department of Medicine, University of Geneva, Geneva, Switzerland ,School of Pharmaceutical Sciences and Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland
| | - Jean-Charles Sanchez
- Swiss Centre for Applied Human Toxicology (SCAHT), Basel, Switzerland ,School of Pharmaceutical Sciences and Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland
| | - Víctor González-Ruiz
- Translational Biomarker Group, Department of Medicine, University of Geneva, Geneva, Switzerland ,School of Pharmaceutical Sciences and Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland
| | - Marie-Gabrielle Zurich
- Department of Biological Sciences, University of Lausanne, Lausanne, Switzerland ,School of Pharmaceutical Sciences and Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland
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Keppner A, Maric D, Orlando IMC, Falquet L, Hummler E, Hoogewijs D. Analysis of the Hypoxic Response in a Mouse Cortical Collecting Duct-Derived Cell Line Suggests That Esrra Is Partially Involved in Hif1α-Mediated Hypoxia-Inducible Gene Expression in mCCD cl1 Cells. Int J Mol Sci 2022; 23:7262. [PMID: 35806266 PMCID: PMC9267015 DOI: 10.3390/ijms23137262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/22/2022] [Accepted: 06/27/2022] [Indexed: 11/16/2022] Open
Abstract
The kidney is strongly dependent on a continuous oxygen supply, and is conversely highly sensitive to hypoxia. Controlled oxygen gradients are essential for renal control of solutes and urine-concentrating mechanisms, which also depend on various hormones including aldosterone. The cortical collecting duct (CCD) is part of the aldosterone-sensitive distal nephron and possesses a key function in fine-tuned distal salt handling. It is well known that aldosterone is consistently decreased upon hypoxia. Furthermore, a recent study reported a hypoxia-dependent down-regulation of sodium currents within CCD cells. We thus investigated the possibility that cells from the cortical collecting duct are responsive to hypoxia, using the mouse cortical collecting duct cell line mCCDcl1 as a model. By analyzing the hypoxia-dependent transcriptome of mCCDcl1 cells, we found a large number of differentially-expressed genes (3086 in total logFC< −1 or >1) following 24 h of hypoxic conditions (0.2% O2). A gene ontology analysis of the differentially-regulated pathways revealed a strong decrease in oxygen-linked processes such as ATP metabolic functions, oxidative phosphorylation, and cellular and aerobic respiration, while pathways associated with hypoxic responses were robustly increased. The most pronounced regulated genes were confirmed by RT-qPCR. The low expression levels of Epas1 under both normoxic and hypoxic conditions suggest that Hif-1α, rather than Hif-2α, mediates the hypoxic response in mCCDcl1 cells. Accordingly, we generated shRNA-mediated Hif-1α knockdown cells and found Hif-1α to be responsible for the hypoxic induction of established hypoxically-induced genes. Interestingly, we could show that following shRNA-mediated knockdown of Esrra, Hif-1α protein levels were unaffected, but the gene expression levels of Egln3 and Serpine1 were significantly reduced, indicating that Esrra might contribute to the hypoxia-mediated expression of these and possibly other genes. Collectively, mCCDcl1 cells display a broad response to hypoxia and represent an adequate cellular model to study additional factors regulating the response to hypoxia.
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Affiliation(s)
- Anna Keppner
- Section of Medicine, Department of Endocrinology, Metabolism and Cardiovascular System (EMC), Faculty of Science and Medicine, University of Fribourg, Chemin du Musée 5, CH-1700 Fribourg, Switzerland; (A.K.); (D.M.); (I.M.C.O.)
- National Center of Competence in Research Kidney Control of Homeostasis (NCCR Kidney.CH), University of Zurich, CH-8006 Zürich, Switzerland
| | - Darko Maric
- Section of Medicine, Department of Endocrinology, Metabolism and Cardiovascular System (EMC), Faculty of Science and Medicine, University of Fribourg, Chemin du Musée 5, CH-1700 Fribourg, Switzerland; (A.K.); (D.M.); (I.M.C.O.)
- National Center of Competence in Research Kidney Control of Homeostasis (NCCR Kidney.CH), University of Zurich, CH-8006 Zürich, Switzerland
| | - Ilaria Maria Christina Orlando
- Section of Medicine, Department of Endocrinology, Metabolism and Cardiovascular System (EMC), Faculty of Science and Medicine, University of Fribourg, Chemin du Musée 5, CH-1700 Fribourg, Switzerland; (A.K.); (D.M.); (I.M.C.O.)
| | - Laurent Falquet
- Section of Science, Department of Biology, Faculty of Science and Medicine, University of Fribourg, CH-1700 Fribourg, Switzerland;
| | - Edith Hummler
- Department of Biomedical Sciences, University of Lausanne, CH-1011 Lausanne, Switzerland;
| | - David Hoogewijs
- Section of Medicine, Department of Endocrinology, Metabolism and Cardiovascular System (EMC), Faculty of Science and Medicine, University of Fribourg, Chemin du Musée 5, CH-1700 Fribourg, Switzerland; (A.K.); (D.M.); (I.M.C.O.)
- National Center of Competence in Research Kidney Control of Homeostasis (NCCR Kidney.CH), University of Zurich, CH-8006 Zürich, Switzerland
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Maliekal TT, Dharmapal D, Sengupta S. Tubulin Isotypes: Emerging Roles in Defining Cancer Stem Cell Niche. Front Immunol 2022; 13:876278. [PMID: 35693789 PMCID: PMC9179084 DOI: 10.3389/fimmu.2022.876278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 05/05/2022] [Indexed: 11/13/2022] Open
Abstract
Although the role of microtubule dynamics in cancer progression is well-established, the roles of tubulin isotypes, their cargos and their specific function in the induction and sustenance of cancer stem cells (CSCs) were poorly explored. But emerging reports urge to focus on the transport function of tubulin isotypes in defining orchestrated expression of functionally critical molecules in establishing a stem cell niche, which is the key for CSC regulation. In this review, we summarize the role of specific tubulin isotypes in the transport of functional molecules that regulate metabolic reprogramming, which leads to the induction of CSCs and immune evasion. Recently, the surface expression of GLUT1 and GRP78 as well as voltage-dependent anion channel (VDAC) permeability, regulated by specific isotypes of β-tubulins have been shown to impart CSC properties to cancer cells, by implementing a metabolic reprogramming. Moreover, βIVb tubulin is shown to be critical in modulating EphrinB1signaling to sustain CSCs in oral carcinoma. These tubulin-interacting molecules, Ephrins, GLUT1 and GRP78, are also important regulators of immune evasion, by evoking PD-L1 mediated T-cell suppression. Thus, the recent advances in the field implicate that tubulins play a role in the controlled transport of molecules involved in CSC niche. The indication of tubulin isotypes in the regulation of CSCs offers a strategy to specifically target those tubulin isotypes to eliminate CSCs, rather than the general inhibition of microtubules, which usually leads to therapy resistance.
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Affiliation(s)
- Tessy Thomas Maliekal
- Cancer Research, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
- Regional Centre for Biotechnology, Faridabad, India
- *Correspondence: Tessy Thomas Maliekal, ; Suparna Sengupta,
| | - Dhrishya Dharmapal
- Cancer Research, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
- University of Kerala, Department of Biotechnology, Thiruvananthapuram, India
| | - Suparna Sengupta
- Cancer Research, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
- Regional Centre for Biotechnology, Faridabad, India
- University of Kerala, Department of Biotechnology, Thiruvananthapuram, India
- *Correspondence: Tessy Thomas Maliekal, ; Suparna Sengupta,
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Li F, Mitchell HD, Mensch AC, Hu D, Laudadio ED, Hedlund Orbeck JK, Hamers RJ, Orr G. Expression Patterns of Energy-Related Genes in Single Cells Uncover Key Isoforms and Enzymes That Gain Priority Under Nanoparticle-Induced Stress. ACS NANO 2022; 16:7197-7209. [PMID: 35290009 PMCID: PMC9134505 DOI: 10.1021/acsnano.1c08934] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 03/07/2022] [Indexed: 06/12/2023]
Abstract
Cellular responses to nanoparticles (NPs) have been largely studied in cell populations, providing averaged values that often misrepresent the true molecular processes that occur in the individual cell. To understand how a cell redistributes limited molecular resources to achieve optimal response and survival requires single-cell analysis. Here we applied multiplex single molecule-based fluorescence in situ hybridization (fliFISH) to quantify the expression of 10 genes simultaneously in individual intact cells, including glycolysis and glucose transporter genes, which are critical for restoring and maintaining energy balance. We focused on individual gill epithelial cell responses to lithium cobalt oxide (LCO) NPs, which are actively pursued as cathode materials in lithium-ion batteries, raising concerns about their impact on the environment and human health. We found large variabilities in the expression levels of all genes between neighboring cells under the same exposure conditions, from only a few transcripts to over 100 copies in individual cells. Gene expression ratios among the 10 genes in each cell uncovered shifts in favor of genes that play key roles in restoring and maintaining energy balance. Among these genes are isoforms that can secure and increase glycolysis rates more efficiently, as well as genes with multiple cellular functions, in addition to glycolysis, including DNA repair, regulation of gene expression, cell cycle progression, and proliferation. Our study uncovered prioritization of gene expression in individual cells for restoring energy balance under LCO NP exposures. Broadly, our study gained insight into single-cell strategies for redistributing limited resources to achieve optimal response and survival under stress.
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Affiliation(s)
- Fangjia Li
- Environmental
Molecular Sciences Laboratory, Pacific Northwest
National laboratory, Richland, Washington 99354, United States
| | - Hugh D. Mitchell
- Biological
Sciences Division, Pacific Northwest National
laboratory, Richland, Washington 99354, United States
| | - Arielle C. Mensch
- Environmental
Molecular Sciences Laboratory, Pacific Northwest
National laboratory, Richland, Washington 99354, United States
| | - Dehong Hu
- Environmental
Molecular Sciences Laboratory, Pacific Northwest
National laboratory, Richland, Washington 99354, United States
| | - Elizabeth D. Laudadio
- Department
of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | | | - Robert J. Hamers
- Department
of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Galya Orr
- Environmental
Molecular Sciences Laboratory, Pacific Northwest
National laboratory, Richland, Washington 99354, United States
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Hypoxia increases expression of selected blood-brain barrier transporters GLUT-1, P-gp, SLC7A5 and TFRC, while maintaining barrier integrity, in brain capillary endothelial monolayers. Fluids Barriers CNS 2022; 19:1. [PMID: 34983574 PMCID: PMC8725498 DOI: 10.1186/s12987-021-00297-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Accepted: 12/15/2021] [Indexed: 01/01/2023] Open
Abstract
Background Brain capillary endothelial cells (BCECs) experience hypoxic conditions during early brain development. The newly formed capillaries are tight and functional before astrocytes and pericytes join the capillaries and establish the neurovascular unit. Brain endothelial cell phenotype markers P-gp (ABCB1), LAT-1(SLC7A5), GLUT-1(SLC2A1), and TFR(TFRC) have all been described to be hypoxia sensitive. Therefore, we hypothesized that monolayers of BCECs, cultured under hypoxic conditions, would show an increase in LAT-1, GLUT-1 and TFR expression and display tight endothelial barriers. Methods and results Primary bovine BCECs were cultured under normoxic and hypoxic conditions. Chronic hypoxia induced HIF-1α stabilization and translocation to the nucleus, as judged by immunocytochemistry and confocal laser scanning imaging. Endothelial cell morphology, claudin-5 and ZO-1 localization and barrier integrity were unaffected by hypoxia, indicating that the tight junctions in the BBB model were not compromised. SLC7A5, SLC2A1, and TFRC-mRNA levels were increased in hypoxic cultures, while ABCB1 remained unchanged as shown by real-time qPCR. P-gp, TfR and GLUT-1 were found to be significantly increased at protein levels. An increase in uptake of [3H]-glucose was demonstrated, while a non-significant increase in the efflux ratio of the P-gp substrate [3H]-digoxin was observed in hypoxic cells. No changes were observed in functional LAT-1 as judged by uptake studies of [3H]-leucine. Stabilization of HIF-1α under normoxic conditions with desferrioxamine (DFO) mimicked the effects of hypoxia on endothelial cells. Furthermore, low concentrations of DFO caused an increase in transendothelial electrical resistance (TEER), suggesting that a slight activation of the HIF-1α system may actually increase brain endothelial monolayer tightness. Moreover, exposure of confluent monolayers to hypoxia resulted in markedly increase in TEER after 24 and 48 h, which corresponded to a higher transcript level of CLDN5. Conclusions Our findings collectively suggest that hypoxic conditions increase some BBB transporters' expression via HIF-1α stabilization, without compromising monolayer integrity. This may in part explain why brain capillaries show early maturation, in terms of barrier tightness and protein expression, during embryogenesis, and provides a novel methodological tool for optimal brain endothelial culture. Supplementary Information The online version contains supplementary material available at 10.1186/s12987-021-00297-6.
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Sod1 integrates oxygen availability to redox regulate NADPH production and the thiol redoxome. Proc Natl Acad Sci U S A 2022; 119:2023328119. [PMID: 34969852 PMCID: PMC8740578 DOI: 10.1073/pnas.2023328119] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2021] [Indexed: 12/12/2022] Open
Abstract
Cu/Zn superoxide dismutase (Sod1) is a key antioxidant enzyme, and its importance is underscored by the fact that its ablation in cell and animal models results in oxidative stress; metabolic defects; and reductions in cell proliferation, viability, and lifespan. Curiously, Sod1 detoxifies superoxide radicals (O2•−) in a manner that produces an oxidant as byproduct, hydrogen peroxide (H2O2). While much is known about the necessity of scavenging O2•−, it is less clear what the physiological roles of Sod1-derived H2O2 are. We discovered that Sod1-derived H2O2 plays an important role in antioxidant defense by stimulating the production of NADPH, a vital cellular reductant required for reactive oxygen species scavenging enzymes, as well as redox regulating a large network of enzymes. Cu/Zn superoxide dismutase (Sod1) is a highly conserved and abundant antioxidant enzyme that detoxifies superoxide (O2•−) by catalyzing its conversion to dioxygen (O2) and hydrogen peroxide (H2O2). Using Saccharomyces cerevisiae and mammalian cells, we discovered that a major aspect of the antioxidant function of Sod1 is to integrate O2 availability to promote NADPH production. The mechanism involves Sod1-derived H2O2 oxidatively inactivating the glycolytic enzyme, GAPDH, which in turn reroutes carbohydrate flux to the oxidative phase of the pentose phosphate pathway (oxPPP) to generate NADPH. The aerobic oxidation of GAPDH is dependent on and rate-limited by Sod1. Thus, Sod1 senses O2 via O2•− to balance glycolytic and oxPPP flux, through control of GAPDH activity, for adaptation to life in air. Importantly, this mechanism for Sod1 antioxidant activity requires the bulk of cellular Sod1, unlike for its role in protection against O2•− toxicity, which only requires <1% of total Sod1. Using mass spectrometry, we identified proteome-wide targets of Sod1-dependent redox signaling, including numerous metabolic enzymes. Altogether, Sod1-derived H2O2 is important for antioxidant defense and a master regulator of metabolism and the thiol redoxome.
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Yao Y, Li YM, He ZX, Civelek AC, Li XF. Likely Common Role of Hypoxia in Driving 18F-FDG Uptake in Cancer, Myocardial Ischemia, Inflammation and Infection. Cancer Biother Radiopharm 2021; 36:624-631. [PMID: 34375126 DOI: 10.1089/cbr.2020.4716] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
First introduced in 1976, 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) has become an indispensable tool for diagnosis and prognostic evaluation of tumors, heart disease, as well as other conditions, including inflammation and infection. Because 18F-FDG can accurately reflect the glucose metabolism level of organs and tissues, it is known as a "century molecule" and is currently the main agent for PET imaging. The degree of 18F-FDG uptake by cells is related to both the rate of glucose metabolism and glucose transporter expression. These, in turn, are strongly influenced by hypoxia, in which cells meet their energy needs through glycolysis, and 18F-FDG uptake increased due to hypoxia. 18F-FDG uptake is a complex process, and hypoxia may be one of the fundamental driving forces. The correct interpretation of 18F-FDG uptake in PET imaging can help clinics make treatment decisions more accurately and effectively. In this article, we review the application of 18F-FDG PET in tumors, myocardium, and inflammation. We discuss the relationship between 18F-FDG uptake and hypoxia, the possible mechanism of 18F-FDG uptake caused by hypoxia, and the associated clinical implications.
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Affiliation(s)
- Yong Yao
- Department of Nuclear Medicine, The Second Clinical Medical College (Shenzhen People's Hospital), Jinan University, Shenzhen, China.,Department of Nuclear Medicine, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, China.,Clinical Medicine Postdoctoral Research Station, Jinan University, Guangzhou, China
| | - Ya-Ming Li
- Department of Nuclear Medicine, the First Hospital of China Medical University, Shenyang, China
| | - Zuo-Xiang He
- Department of Nuclear Medicine, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
| | - A Cahid Civelek
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Johns Hopkins Medicine, Baltimore, Maryland, USA
| | - Xiao-Feng Li
- Department of Nuclear Medicine, The Second Clinical Medical College (Shenzhen People's Hospital), Jinan University, Shenzhen, China.,Department of Nuclear Medicine, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, China
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Chan JS, Chiew AE, Rimke AN, Chan G, Rampuri ZH, Kozak MD, Boulé NG, Steinback CD, Davenport MH, Day TA. Blood glucose concentration is unchanged during exposure to acute normobaric hypoxia in healthy humans. Physiol Rep 2021; 9:e14932. [PMID: 34337893 PMCID: PMC8327160 DOI: 10.14814/phy2.14932] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 05/24/2021] [Accepted: 05/25/2021] [Indexed: 11/24/2022] Open
Abstract
Normal blood [glucose] regulation is critical to support metabolism, particularly in contexts of metabolic stressors (e.g., exercise, high altitude hypoxia). Data regarding blood [glucose] regulation in hypoxia are inconclusive. We aimed to characterize blood [glucose] over 80 min following glucose ingestion during both normoxia and acute normobaric hypoxia. In a randomized cross-over design, on two separate days, 28 healthy participants (16 females; 21.8 ± 1.6 years; BMI 22.8 ± 2.5 kg/m2 ) were randomly exposed to either NX (room air; fraction of inspired [FI ]O2 ~0.21) or HX (FI O2 ~0.148) in a normobaric hypoxia chamber. Measured FI O2 and peripheral oxygen saturation were both lower at baseline in hypoxia (p < 0.001), which was maintained over 80 min, confirming the hypoxic intervention. Following a 10-min baseline (BL) under both conditions, participants consumed a standardized glucose beverage (75 g, 296 ml) and blood [glucose] and physiological variables were measured at BL intermittently over 80 min. Blood [glucose] was measured from finger capillary samples via glucometer. Initial fasted blood [glucose] was not different between trials (NX:4.8 ± 0.4 vs. HX:4.9 ± 0.4 mmol/L; p = 0.47). Blood [glucose] was sampled every 10 min (absolute, delta, and percent change) following glucose ingestion over 80 min, and was not different between conditions (p > 0.77). In addition, mean, peak, and time-to-peak responses during the 80 min were not different between conditions (p > 0.14). There were also no sex differences in these blood [glucose] responses in hypoxia. We conclude that glucose regulation is unchanged in young, healthy participants with exposure to acute steady-state normobaric hypoxia, likely due to counterbalancing mechanisms underlying blood [glucose] regulation in hypoxia.
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Affiliation(s)
- Jason S. Chan
- Department of BiologyFaculty of Science and TechnologyMount Royal UniversityCalgaryABCanada
| | - Alexandra E. Chiew
- Department of BiologyFaculty of Science and TechnologyMount Royal UniversityCalgaryABCanada
| | - Alexander N. Rimke
- Department of BiologyFaculty of Science and TechnologyMount Royal UniversityCalgaryABCanada
| | - Garrick Chan
- Department of BiologyFaculty of Science and TechnologyMount Royal UniversityCalgaryABCanada
| | - Zahrah H. Rampuri
- Department of BiologyFaculty of Science and TechnologyMount Royal UniversityCalgaryABCanada
| | - Mackenzie D. Kozak
- Department of BiologyFaculty of Science and TechnologyMount Royal UniversityCalgaryABCanada
| | - Normand G. Boulé
- Alberta Diabetes InstituteFaculty of Kinesiology, Sport, and RecreationUniversity of AlbertaEdmontonABCanada
| | - Craig D. Steinback
- Alberta Diabetes InstituteFaculty of Kinesiology, Sport, and RecreationUniversity of AlbertaEdmontonABCanada
| | - Margie H. Davenport
- Alberta Diabetes InstituteFaculty of Kinesiology, Sport, and RecreationUniversity of AlbertaEdmontonABCanada
| | - Trevor A. Day
- Department of BiologyFaculty of Science and TechnologyMount Royal UniversityCalgaryABCanada
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11
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Logette E, Lorin C, Favreau C, Oshurko E, Coggan JS, Casalegno F, Sy MF, Monney C, Bertschy M, Delattre E, Fonta PA, Krepl J, Schmidt S, Keller D, Kerrien S, Scantamburlo E, Kaufmann AK, Markram H. A Machine-Generated View of the Role of Blood Glucose Levels in the Severity of COVID-19. Front Public Health 2021; 9:695139. [PMID: 34395368 PMCID: PMC8356061 DOI: 10.3389/fpubh.2021.695139] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 06/30/2021] [Indexed: 01/08/2023] Open
Abstract
SARS-CoV-2 started spreading toward the end of 2019 causing COVID-19, a disease that reached pandemic proportions among the human population within months. The reasons for the spectrum of differences in the severity of the disease across the population, and in particular why the disease affects more severely the aging population and those with specific preconditions are unclear. We developed machine learning models to mine 240,000 scientific articles openly accessible in the CORD-19 database, and constructed knowledge graphs to synthesize the extracted information and navigate the collective knowledge in an attempt to search for a potential common underlying reason for disease severity. The machine-driven framework we developed repeatedly pointed to elevated blood glucose as a key facilitator in the progression of COVID-19. Indeed, when we systematically retraced the steps of the SARS-CoV-2 infection, we found evidence linking elevated glucose to each major step of the life-cycle of the virus, progression of the disease, and presentation of symptoms. Specifically, elevations of glucose provide ideal conditions for the virus to evade and weaken the first level of the immune defense system in the lungs, gain access to deep alveolar cells, bind to the ACE2 receptor and enter the pulmonary cells, accelerate replication of the virus within cells increasing cell death and inducing an pulmonary inflammatory response, which overwhelms an already weakened innate immune system to trigger an avalanche of systemic infections, inflammation and cell damage, a cytokine storm and thrombotic events. We tested the feasibility of the hypothesis by manually reviewing the literature referenced by the machine-generated synthesis, reconstructing atomistically the virus at the surface of the pulmonary airways, and performing quantitative computational modeling of the effects of glucose levels on the infection process. We conclude that elevation in glucose levels can facilitate the progression of the disease through multiple mechanisms and can explain much of the differences in disease severity seen across the population. The study provides diagnostic considerations, new areas of research and potential treatments, and cautions on treatment strategies and critical care conditions that induce elevations in blood glucose levels.
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Affiliation(s)
- Emmanuelle Logette
- Blue Brain Project, École polytechnique fédérale de Lausanne (EPFL), Geneva, Switzerland
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Henry Markram
- Blue Brain Project, École polytechnique fédérale de Lausanne (EPFL), Geneva, Switzerland
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12
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Zamora-Briseño JA, Améndola-Pimenta M, Ortega-Rosas DA, Pereira-Santana A, Hernández-Velázquez IM, González-Penagos CE, Pérez-Vega JA, Del Río-García M, Árcega-Cabrera F, Rodríguez-Canul R. Gill and liver transcriptomic responses of Achirus lineatus (Neopterygii: Achiridae) exposed to water-accommodated fraction (WAF) of light crude oil reveal an onset of hypoxia-like condition. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:34309-34327. [PMID: 33646544 DOI: 10.1007/s11356-021-12909-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 02/08/2021] [Indexed: 06/12/2023]
Abstract
Crude oil is one of the most widespread pollutants released into the marine environment, and native species have provided useful information about the effect of crude oil pollution in marine ecosystems. We consider that the lined sole Achirus lineatus can be a useful monitor of the effect of crude oil in the Gulf of Mexico (GoM) because this flounder species has a wide distribution along the GoM, and its response to oil components is relevant. The objective of this study was to compare the transcriptomic changes in liver and gill of adults lined sole fish (Achirus lineatus) exposed to a sublethal acute concentration of water-accommodated fraction (WAF) of light crude oil for 48 h. RNA-Seq was performed to assess the transcriptional changes in both organs. A total of 1073 differentially expressed genes (DEGs) were detected in gills; 662 (61.69%) were upregulated, and 411 (38.30%) were downregulated whereas in liver, 515 DEGs; 306 (59.42%) were upregulated, and 209 (40.58%) were downregulated. Xenobiotic metabolism and redox metabolism, along with DNA repair mechanisms, were activated. The induction of hypoxia-regulated genes and the generalized regulation of multiple signaling pathways support the hypothesis that WAF exposition causes a hypoxia-like condition.
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Affiliation(s)
- Jesús Alejandro Zamora-Briseño
- Departamento de Recursos del Mar, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional-Unidad Mérida, Km 6 Antigua Carretera a Progreso, CORDEMEX, CP 97310, Mérida, Yucatán, Mexico
| | - Monica Améndola-Pimenta
- Departamento de Recursos del Mar, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional-Unidad Mérida, Km 6 Antigua Carretera a Progreso, CORDEMEX, CP 97310, Mérida, Yucatán, Mexico
| | | | - Alejandro Pereira-Santana
- División de Biotecnología Industrial, CONACYT-Centro de Investigación y Asistencia en Tecnología y Diseño del estado de Jalisco, Camino Arenero 1227, El Bajío, C.P. 45019, Zapopan, Jalisco, Mexico
| | - Ioreni Margarita Hernández-Velázquez
- Departamento de Recursos del Mar, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional-Unidad Mérida, Km 6 Antigua Carretera a Progreso, CORDEMEX, CP 97310, Mérida, Yucatán, Mexico
| | - Carlos Eduardo González-Penagos
- Departamento de Recursos del Mar, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional-Unidad Mérida, Km 6 Antigua Carretera a Progreso, CORDEMEX, CP 97310, Mérida, Yucatán, Mexico
| | - Juan Antonio Pérez-Vega
- Departamento de Recursos del Mar, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional-Unidad Mérida, Km 6 Antigua Carretera a Progreso, CORDEMEX, CP 97310, Mérida, Yucatán, Mexico
| | - Marcela Del Río-García
- Departamento de Recursos del Mar, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional-Unidad Mérida, Km 6 Antigua Carretera a Progreso, CORDEMEX, CP 97310, Mérida, Yucatán, Mexico
| | - Flor Árcega-Cabrera
- Unidad de Química Sisal, Facultad de Química, Universidad Nacional Autónoma de México, Puerto de Abrigo S/N, 97356, Sisal, Yucatán, Mexico
| | - Rossanna Rodríguez-Canul
- Departamento de Recursos del Mar, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional-Unidad Mérida, Km 6 Antigua Carretera a Progreso, CORDEMEX, CP 97310, Mérida, Yucatán, Mexico.
- Laboratorio de Inmunología y Biología Molecular, CINVESTAV-IPN Unidad Mérida, Antigua carretera a Progreso Km 6., CP 97310, Mérida, Yucatán, Mexico.
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13
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Page LK, Staples KJ, Spalluto CM, Watson A, Wilkinson TMA. Influence of Hypoxia on the Epithelial-Pathogen Interactions in the Lung: Implications for Respiratory Disease. Front Immunol 2021; 12:653969. [PMID: 33868294 PMCID: PMC8044850 DOI: 10.3389/fimmu.2021.653969] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/09/2021] [Indexed: 12/11/2022] Open
Abstract
Under normal physiological conditions, the lung remains an oxygen rich environment. However, prominent regions of hypoxia are a common feature of infected and inflamed tissues and many chronic inflammatory respiratory diseases are associated with mucosal and systemic hypoxia. The airway epithelium represents a key interface with the external environment and is the first line of defense against potentially harmful agents including respiratory pathogens. The protective arsenal of the airway epithelium is provided in the form of physical barriers, and the production of an array of antimicrobial host defense molecules, proinflammatory cytokines and chemokines, in response to activation by receptors. Dysregulation of the airway epithelial innate immune response is associated with a compromised immunity and chronic inflammation of the lung. An increasing body of evidence indicates a distinct role for hypoxia in the dysfunction of the airway epithelium and in the responses of both innate immunity and of respiratory pathogens. Here we review the current evidence around the role of tissue hypoxia in modulating the host-pathogen interaction at the airway epithelium. Furthermore, we highlight the work needed to delineate the role of tissue hypoxia in the pathophysiology of chronic inflammatory lung diseases such as asthma, cystic fibrosis, and chronic obstructive pulmonary disease in addition to novel respiratory diseases such as COVID-19. Elucidating the molecular mechanisms underlying the epithelial-pathogen interactions in the setting of hypoxia will enable better understanding of persistent infections and complex disease processes in chronic inflammatory lung diseases and may aid the identification of novel therapeutic targets and strategies.
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Affiliation(s)
- Lee K Page
- Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, Southampton, United Kingdom
| | - Karl J Staples
- Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, Southampton, United Kingdom.,NIHR Southampton Biomedical Research Centre, Southampton Centre for Biomedical Research, Southampton General Hospital, Southampton, United Kingdom
| | - C Mirella Spalluto
- Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, Southampton, United Kingdom.,NIHR Southampton Biomedical Research Centre, Southampton Centre for Biomedical Research, Southampton General Hospital, Southampton, United Kingdom
| | - Alastair Watson
- Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, Southampton, United Kingdom.,NIHR Southampton Biomedical Research Centre, Southampton Centre for Biomedical Research, Southampton General Hospital, Southampton, United Kingdom.,Birmingham Medical School, University of Birmingham, Birmingham, United Kingdom
| | - Tom M A Wilkinson
- Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, Southampton, United Kingdom.,NIHR Southampton Biomedical Research Centre, Southampton Centre for Biomedical Research, Southampton General Hospital, Southampton, United Kingdom
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14
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Labrecque MP, Brown LG, Coleman IM, Nguyen HM, Lin DW, Corey E, Nelson PS, Morrissey C. Cabozantinib can block growth of neuroendocrine prostate cancer patient-derived xenografts by disrupting tumor vasculature. PLoS One 2021; 16:e0245602. [PMID: 33471819 PMCID: PMC7817027 DOI: 10.1371/journal.pone.0245602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 01/04/2021] [Indexed: 12/15/2022] Open
Abstract
With the advent of potent second-line anti-androgen therapy, we and others have observed an increased incidence of androgen receptor (AR)-null small cell or neuroendocrine prostate cancer (SCNPC) in metastatic castration-resistant prostate cancer (mCRPC). Our study was designed to determine the effect of cabozantinib, a multi-targeted tyrosine kinase inhibitor that inhibits VEGFR2, MET and RET on SCNPC. Transcriptome analysis of the University of Washington rapid autopsy and SU2C mCRPC datasets revealed upregulated MET and RET expression in SCNPCs relative to adenocarcinomas. Additionally, increased MET expression correlated with attenuated AR expression and activity. In vitro treatment of SCNPC patient-derived xenograft (PDX) cells with the MET inhibitor AMG-337 had no impact on cell viability in LuCaP 93 (MET+/RET+) and LuCaP 173.1 (MET-/RET-), whereas cabozantinib decreased cell viability of LuCaP 93, but not LuCaP 173.1. Notably, MET+/RET+ LuCaP 93 and MET-/RET- LuCaP 173.1 tumor volumes were significantly decreased with cabozantinib treatment in vivo, and this activity was independent of MET or RET expression in LuCaP 173.1. Tissue analysis indicated that cabozantinib did not inhibit tumor cell proliferation (Ki67), but significantly decreased microvessel density (CD31) and increased hypoxic stress and glycolysis (HK2) in LuCaP 93 and LuCaP 173.1 tumors. RNA-Seq and gene set enrichment analysis revealed that hypoxia and glycolysis pathways were increased in cabozantinib-treated tumors relative to control tumors. Our data suggest that the most likely mechanism of cabozantinib-mediated tumor growth suppression in SCNPC PDX models is through disruption of the tumor vasculature. Thus, cabozantinib may represent a potential therapy for patients with metastatic disease in tumor phenotypes that have a significant dependence on the tumor vasculature for survival and proliferation.
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Affiliation(s)
- Mark P. Labrecque
- Department of Urology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Lisha G. Brown
- Department of Urology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Ilsa M. Coleman
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Holly M. Nguyen
- Department of Urology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Daniel W. Lin
- Department of Urology, University of Washington School of Medicine, Seattle, Washington, United States of America
- Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Eva Corey
- Department of Urology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Peter S. Nelson
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Colm Morrissey
- Department of Urology, University of Washington School of Medicine, Seattle, Washington, United States of America
- * E-mail:
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15
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Islam ABMMK, Khan MAAK. Lung transcriptome of a COVID-19 patient and systems biology predictions suggest impaired surfactant production which may be druggable by surfactant therapy. Sci Rep 2020; 10:19395. [PMID: 33173052 PMCID: PMC7656460 DOI: 10.1038/s41598-020-76404-8] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 10/28/2020] [Indexed: 12/12/2022] Open
Abstract
An incomplete understanding of the molecular mechanisms behind impairment of lung pathobiology by COVID-19 complicates its clinical management. In this study, we analyzed the gene expression pattern of cells obtained from biopsies of COVID-19-affected patient and compared to the effects observed in typical SARS-CoV-2 and SARS-CoV-infected cell-lines. We then compared gene expression patterns of COVID-19-affected lung tissues and SARS-CoV-2-infected cell-lines and mapped those to known lung-related molecular networks, including hypoxia induced responses, lung development, respiratory processes, cholesterol biosynthesis and surfactant metabolism; all of which are suspected to be downregulated following SARS-CoV-2 infection based on the observed symptomatic impairments. Network analyses suggest that SARS-CoV-2 infection might lead to acute lung injury in COVID-19 by affecting surfactant proteins and their regulators SPD, SPC, and TTF1 through NSP5 and NSP12; thrombosis regulators PLAT, and EGR1 by ORF8 and NSP12; and mitochondrial NDUFA10, NDUFAF5, and SAMM50 through NSP12. Furthermore, hypoxia response through HIF-1 signaling might also be targeted by SARS-CoV-2 proteins. Drug enrichment analysis of dysregulated genes has allowed us to propose novel therapies, including lung surfactants, respiratory stimulants, sargramostim, and oseltamivir. Our study presents a distinct mechanism of probable virus induced lung damage apart from cytokine storm.
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16
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Thomas S. The Structure of the Membrane Protein of SARS-CoV-2 Resembles the Sugar Transporter SemiSWEET. Pathog Immun 2020; 5:342-363. [PMID: 33154981 PMCID: PMC7608487 DOI: 10.20411/pai.v5i1.377] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 06/16/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the disease COVID-19 that has decimated the health and economy of our planet. The virus causes the disease not only in people but also in companion and wild animals. People with diabetes are at risk of the disease. As yet we do not know why the virus has been highly successful in causing the pandemic within 3 months of its first report. The structural proteins of SARS include membrane glycoprotein (M), envelope protein (E), nucleocapsid protein (N), and the spike protein (S). METHODS The structure and function of the most abundant structural protein of SARS-CoV-2, the membrane (M) glycoprotein, is not fully understood. Using in silico analyses we determined the structure and potential function of the M protein. RESULTS The M protein of SARS-CoV-2 is 98.6% similar to the M protein of bat SARS-CoV, maintains 98.2% homology with pangolin SARS-CoV, and has 90% homology with the M protein of SARS-CoV; whereas, the similarity is only 38% with the M protein of MERS-CoV. In silico analyses showed that the M protein of SARS-CoV-2 has a triple helix bundle, forms a single 3-trans-membrane domain, and is homologous to the prokaryotic sugar transport protein SemiSWEET. SemiSWEETs are related to the PQ-loop family whose members function as cargo receptors in vesicle transport, mediate movement of basic amino acids across lysosomal membranes, and are also involved in phospholipase flippase function. CONCLUSIONS The advantage and role of the M protein having a sugar transporter-like structure is not clearly understood. The M protein of SARS-CoV-2 interacts with S, E, and N protein. The S protein of the virus is glycosylated. It could be hypothesized that the sugar transporter-like structure of the M protein influences glycosylation of the S protein. Endocytosis is critical for the internalization and maturation of RNA viruses, including SARS-CoV-2. Sucrose is involved in endosome and lysosome maturation and may also induce autophagy, pathways that help in the entry of the virus. Overall, it could be hypothesized that the SemiSWEET sugar transporter-like structure of the M protein may be involved in multiple functions that may aid in the rapid proliferation, replication, and immune evasion of the SARS-CoV-2 virus. Biological experiments would validate the presence and function of the SemiSWEET sugar transporter.
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Affiliation(s)
- Sunil Thomas
- Lankenau Institute for Medical Research, Wynnewood, PA-19096, USA
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17
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Khatri R, Gupta RK, Vats P, Bansal V, Yadav AK, Reddy PK, Bharadwaj A, Chaudhary P, Sharma S, Bajaj AC, Deskit P, Dass D, Baburaj TP, Singh SB, Kumar B. Subclinical elevated B-type Natriuretic Peptide (BNP) indicates endothelial dysfunction contributing to hypoxia susceptibility in healthy individuals. Life Sci 2020; 260:118408. [PMID: 32926931 PMCID: PMC7486215 DOI: 10.1016/j.lfs.2020.118408] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/31/2020] [Accepted: 09/04/2020] [Indexed: 12/21/2022]
Abstract
Aims Baseline elevated B-type Natriuretic Peptide (BNP) has been found in high altitude pulmonary edema susceptible population. Exaggerated pulmonary vascular response to hypoxia may be related to endothelial dysfunction in hypoxia susceptible. We hypothesize that baseline BNP levels can predict hypoxia susceptibility in healthy individuals. Main methods The pulmonary vascular response to hypoxia was compared in 35 male healthy individuals divided into two groups based on BNP levels (Group 1 ≤ 15 and Group 2 > 15 pg/ml). Acute normobaric hypoxia was administered to both the groups, to confirm hypoxia susceptibility in Group 2. Key findings Unlike Group 1, Group 2 had elevated post hypoxia BNP levels (26 vs 33.5 pg/ml, p = 0.002) while pulmonary artery pressure was comparable. A negative correlation with tissue oxygen consumption (delta pO2) and compartmental fluid shift was seen in Group 1 only. Endothelial dysfunction in Group 2 resulted in reduced vascular compliance leading to elevation of mean blood pressure on acute hypoxia exposure. BNP showed a positive correlation with endothelial dysfunction in Group 2 and has been linked to pre-diabetic disorder (HbA1c 6 ± 0.44%) and may additionally represent a lower cross-sectional area of vascular bed related to vascular remodeling mediated by chronic hypoxia. Significance Hypoxia susceptibility in healthy individuals may be related to endothelial dysfunction that limits vascular compliance during hypoxic stress. BNP level showed positive correlation with HbA1c (r = 0.49, p = 0.04) and negative correlation with delta pO2 (r = −0.52, p = 0.04) can predict reduced microvascular compliance due to endothelial dysfunction contributing to hypoxia susceptibility in healthy individuals. BNP levels≤15 pg/ml at sea level is indicative of hypoxia resistance.
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Affiliation(s)
- Rahul Khatri
- Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi 110054, India
| | - Rajinder K Gupta
- Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi 110054, India.
| | - Praveen Vats
- Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi 110054, India
| | - Vishal Bansal
- Vallabhbhai Patel Chest Institute (VPCI), Delhi University, New Delhi, Delhi 110007, India
| | - Anand Kumar Yadav
- Vallabhbhai Patel Chest Institute (VPCI), Delhi University, New Delhi, Delhi 110007, India
| | - Prasanna K Reddy
- Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi 110054, India
| | - Abhishek Bharadwaj
- Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi 110054, India
| | - Pooja Chaudhary
- Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi 110054, India
| | - Shivani Sharma
- Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi 110054, India
| | - Amir Chand Bajaj
- Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi 110054, India
| | - Padma Deskit
- Sonam Norboo Memorial (S.N.M.) Hospital, Leh-Ladakh, Jammu and Kashmir 194101, India
| | - Deepak Dass
- Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi 110054, India
| | - Thiruthara P Baburaj
- Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi 110054, India
| | - Shashi Bala Singh
- Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi 110054, India
| | - Bhuvnesh Kumar
- Defence Institute of Physiology and Allied Sciences (DIPAS), Timarpur, Delhi 110054, India
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18
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Flint LE, Hamm G, Ready JD, Ling S, Duckett CJ, Cross NA, Cole LM, Smith DP, Goodwin RJA, Clench MR. Characterization of an Aggregated Three-Dimensional Cell Culture Model by Multimodal Mass Spectrometry Imaging. Anal Chem 2020; 92:12538-12547. [PMID: 32786495 PMCID: PMC7497704 DOI: 10.1021/acs.analchem.0c02389] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
![]()
Mass
spectrometry imaging (MSI) is an established analytical tool
capable of defining and understanding complex tissues by determining
the spatial distribution of biological molecules. Three-dimensional
(3D) cell culture models mimic the pathophysiological environment
of in vivo tumors and are rapidly emerging as a valuable
research tool. Here, multimodal MSI techniques were employed to characterize
a novel aggregated 3D lung adenocarcinoma model, developed by the
group to mimic the in vivo tissue. Regions of tumor
heterogeneity and the hypoxic microenvironment were observed based
on the spatial distribution of a variety of endogenous molecules.
Desorption electrospray ionization (DESI)-MSI defined regions of a
hypoxic core and a proliferative outer layer from metabolite distribution.
Targeted metabolites (e.g., lactate, glutamine, and citrate) were
mapped to pathways of glycolysis and the TCA cycle demonstrating tumor
metabolic behavior. The first application of imaging mass cytometry
(IMC) with 3D cell culture enabled single-cell phenotyping at 1 μm
spatial resolution. Protein markers of proliferation (Ki-67) and hypoxia (glucose transporter 1) defined metabolic
signaling in the aggregoid model, which complemented the metabolite
data. Laser ablation inductively coupled plasma (LA-ICP)-MSI analysis
localized endogenous elements including magnesium and copper, further
differentiating the hypoxia gradient and validating the protein expression.
Obtaining a large amount of molecular information on a complementary
nature enabled an in-depth understanding of the biological processes
within the novel tumor model. Combining powerful imaging techniques
to characterize the aggregated 3D culture highlighted a future methodology
with potential applications in cancer research and drug development.
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Affiliation(s)
- Lucy E Flint
- Centre for Mass Spectrometry Imaging, Biomolecular Research Centre, Sheffield Hallam University, Howard Street, Sheffield S1 1WB, United Kingdom
| | - Gregory Hamm
- Imaging and Data Analytics, Clinical Pharmacology and Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, Darwin Building, Cambridge Science Park, Milton Road, Cambridge, Cambridgeshire CB4 0WG, United Kingdom
| | - Joseph D Ready
- Centre for Mass Spectrometry Imaging, Biomolecular Research Centre, Sheffield Hallam University, Howard Street, Sheffield S1 1WB, United Kingdom
| | - Stephanie Ling
- Imaging and Data Analytics, Clinical Pharmacology and Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, Darwin Building, Cambridge Science Park, Milton Road, Cambridge, Cambridgeshire CB4 0WG, United Kingdom
| | - Catherine J Duckett
- Centre for Mass Spectrometry Imaging, Biomolecular Research Centre, Sheffield Hallam University, Howard Street, Sheffield S1 1WB, United Kingdom
| | - Neil A Cross
- Centre for Mass Spectrometry Imaging, Biomolecular Research Centre, Sheffield Hallam University, Howard Street, Sheffield S1 1WB, United Kingdom
| | - Laura M Cole
- Centre for Mass Spectrometry Imaging, Biomolecular Research Centre, Sheffield Hallam University, Howard Street, Sheffield S1 1WB, United Kingdom
| | - David P Smith
- Centre for Mass Spectrometry Imaging, Biomolecular Research Centre, Sheffield Hallam University, Howard Street, Sheffield S1 1WB, United Kingdom
| | - Richard J A Goodwin
- Imaging and Data Analytics, Clinical Pharmacology and Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, Darwin Building, Cambridge Science Park, Milton Road, Cambridge, Cambridgeshire CB4 0WG, United Kingdom.,Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Malcolm R Clench
- Centre for Mass Spectrometry Imaging, Biomolecular Research Centre, Sheffield Hallam University, Howard Street, Sheffield S1 1WB, United Kingdom
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19
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Hewitson TD, Holt SG, Samuel CS, Wigg B, Smith ER. Profiling histone modifications in the normal mouse kidney and after unilateral ureteric obstruction. Am J Physiol Renal Physiol 2019; 317:F606-F615. [DOI: 10.1152/ajprenal.00262.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Posttranslational modification of nucleosomal histones is a major determinant of chromatin structure and gene activity. In the present study, we hypothesized that unilateral ureteric obstruction (UUO), a widely used model of tubulointerstitial injury, would be associated with a distinct pattern of histone modifications (marks) in the kidney. Mass spectrometry was used to profile 63 different histone marks in normal mouse kidneys and those after 10 days of UUO. A subsequent histochemical analysis further examined examples of specific marks that changed significantly after UUO for which antisera are available. Histone marks were much more widely distributed and abundant in the normal kidney than is usually appreciated. Although aggregate analysis of the mass spectrometry results revealed net differences between control and UUO groups, residue-specific variations were subtle. Of the 16/63 significant changes ( P < 0.05), only 8 changes were quantitatively different by >5%. Nevertheless, we identified several that are not usually examined in the kidney, including marks in the globular domain of core histones (H3:K79), linker histones (H1.4), and histone variants (H3.1:K27 and H3.3:K27). In several cases, there were complementary changes in different marks on the same amino acid. Using H3:K79ME2 as an example, mark enrichment was heterogeneous but largely colocalized with active transcription in a subset of tubular pathology. In conclusion, our study highlights the importance of unbiased screening in examining histone marks. Simultaneous changes in multiple marks on the same amino acid indicate a coordinated histone mark signature. The heterogeneous enrichment of marks, even within the same tubule, highlights the importance of regulatory context.
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Affiliation(s)
- Timothy D. Hewitson
- Department of Nephrology, Royal Melbourne Hospital, Parkville, Victoria, Australia
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
| | - Stephen G. Holt
- Department of Nephrology, Royal Melbourne Hospital, Parkville, Victoria, Australia
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
| | - Chrishan S. Samuel
- Biomedicine Discovery Institute and Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Belinda Wigg
- Department of Nephrology, Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Edward R. Smith
- Department of Nephrology, Royal Melbourne Hospital, Parkville, Victoria, Australia
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
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20
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Sodium-glucose cotransporters: new targets of cancer therapy? Arh Hig Rada Toksikol 2019; 69:278-285. [PMID: 30864374 DOI: 10.2478/aiht-2018-69-3204] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Accepted: 11/01/2018] [Indexed: 01/17/2023] Open
Abstract
Glucose, the key source of metabolic energy, is imported into cells by two categories of transporters: 1) facilitative glucose transporters (GLUTs) and 2) secondary active sodium-glucose cotransporters (SGLTs). Cancer cells have an increased demand for glucose uptake and utilisation compared to normal cells. Previous studies have demonstrated the overexpression of GLUTs, mainly GLUT1, in many cancer types. As the current standard positron emission tomography (PET) tracer 2-deoxy-2-(18F)fluoro-D-glucose (2-FDG) for imaging tumour cells via GLUT1 lacks in sensitivity and specificity, it may soon be replaced by the newly designed, highly sensitive and specific SGLT tracer α-methyl-4-(F-18)fluoro-4-deoxy-Dglucopyranoside (Me-4FDG) in clinical detection and tumour staging. This tracer has recently demonstrated the functional activity of SGLT in pancreatic, prostate, and brain cancers. The mRNA and protein expression of SGLTs have also been reported in colon/colorectal, lung, ovarian, head, neck, and oral squamous carcinomas. So far, SGLTs have been poorly investigated in cancer, and their protein expression and localisation are often controversial due to a lack of specific SGLT antibodies. In this review, we describe current knowledge concerning SGLT1 and SGLT2 (over)expression in various cancer types. The findings of SGLTs in malignant cells may help in developing novel cancer therapies with SGLT2 or SGLT1/SGLT2 inhibitors already used in diabetes mellitus treatment.
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21
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Additional effects of duodenojejunal bypass on glucose metabolism in a rat model of sleeve gastrectomy. Surg Today 2019; 49:637-644. [DOI: 10.1007/s00595-019-1772-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 01/12/2019] [Indexed: 02/07/2023]
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22
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Bernhardt S, Tönsing C, Mitra D, Erdem N, Müller-Decker K, Korf U, Kreutz C, Timmer J, Wiemann S. Functional Proteomics of Breast Cancer Metabolism Identifies GLUL as Responder during Hypoxic Adaptation. J Proteome Res 2019; 18:1352-1362. [PMID: 30609375 DOI: 10.1021/acs.jproteome.8b00944] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Hypoxia as well as metabolism are central hallmarks of cancer, and hypoxia-inducible factors (HIFs) and metabolic effectors are crucial elements in oxygen-compromised tumor environments. Knowledge of changes in the expression of metabolic proteins in response to HIF function could provide mechanistic insights into adaptation to hypoxic stress, tumorigenesis, and disease progression. We analyzed time-resolved alterations in metabolism-associated protein levels in response to different oxygen potentials across breast cancer cell lines. Effects on the cellular metabolism of both HIF-dependent and -independent processes were analyzed by reverse-phase protein array profiling and a custom statistical model. We revealed a strong induction of glucose transporter 1 (GLUT1) and lactate dehydrogenase A (LDHA) as well as reduced glutamate-ammonia ligase (GLUL) protein levels across all cell lines tested as consistent changes upon hypoxia induction. Low GLUL protein levels were correlated with aggressive molecular subtypes in breast cancer patient data sets and also with hypoxic tumor regions in a xenograft mouse tumor model. Moreover, low GLUL expression was associated with poor survival in breast cancer patients and with high HIF-1α-expressing patient subgroups. Our data reveal time-resolved changes in the regulation of metabolic proteins under oxygen-deprived conditions and elucidate GLUL as a strong responder to HIFs and the hypoxic environment.
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Affiliation(s)
- Stephan Bernhardt
- Division of Molecular Genome Analysis , German Cancer Research Center (DKFZ) , Im Neuenheimer Feld 580 , 69120 Heidelberg , Germany
| | - Christian Tönsing
- Institute of Physics , University of Freiburg , Hermann-Herder-Str. 3 , 79104 Freiburg , Germany
| | - Devina Mitra
- Division of Molecular Genome Analysis , German Cancer Research Center (DKFZ) , Im Neuenheimer Feld 580 , 69120 Heidelberg , Germany
| | - Nese Erdem
- Division of Molecular Genome Analysis , German Cancer Research Center (DKFZ) , Im Neuenheimer Feld 580 , 69120 Heidelberg , Germany.,Faculty of Biosciences , Heidelberg University , Im Neuenheimer Feld 234 , 69120 Heidelberg , Germany
| | - Karin Müller-Decker
- DKFZ Tumor Models Core Facility , German Cancer Research Center (DKFZ) , Im Neuenheimer Feld 280 , 69120 Heidelberg , Germany
| | - Ulrike Korf
- Division of Molecular Genome Analysis , German Cancer Research Center (DKFZ) , Im Neuenheimer Feld 580 , 69120 Heidelberg , Germany
| | - Clemens Kreutz
- Center for Systems Biology (ZBSA) , University of Freiburg , Habsburgerstr. 49 , 79104 Freiburg , Germany.,CIBSS Centre for Integrative Biological Signalling Studies , University of Freiburg , Schänzlestr. 18 , 79104 Freiburg , Germany
| | - Jens Timmer
- Institute of Physics , University of Freiburg , Hermann-Herder-Str. 3 , 79104 Freiburg , Germany.,Center for Systems Biology (ZBSA) , University of Freiburg , Habsburgerstr. 49 , 79104 Freiburg , Germany.,CIBSS Centre for Integrative Biological Signalling Studies , University of Freiburg , Schänzlestr. 18 , 79104 Freiburg , Germany
| | - Stefan Wiemann
- Division of Molecular Genome Analysis , German Cancer Research Center (DKFZ) , Im Neuenheimer Feld 580 , 69120 Heidelberg , Germany.,Faculty of Biosciences , Heidelberg University , Im Neuenheimer Feld 234 , 69120 Heidelberg , Germany
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23
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Muñoz‐Sánchez J, Chánez‐Cárdenas ME. The use of cobalt chloride as a chemical hypoxia model. J Appl Toxicol 2018; 39:556-570. [DOI: 10.1002/jat.3749] [Citation(s) in RCA: 149] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 09/13/2018] [Accepted: 10/07/2018] [Indexed: 12/19/2022]
Affiliation(s)
- Jorge Muñoz‐Sánchez
- Laboratorio de Patología Vascular CerebralInstituto Nacional de Neurología y Neurología (INNN) Insurgentes Sur 3877, la Fama 14269 Tlalpan Ciudad de México Mexico
| | - María E. Chánez‐Cárdenas
- Laboratorio de Patología Vascular CerebralInstituto Nacional de Neurología y Neurología (INNN) Insurgentes Sur 3877, la Fama 14269 Tlalpan Ciudad de México Mexico
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24
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Galardo MN, Gorga A, Merlo JP, Regueira M, Pellizzari EH, Cigorraga SB, Riera MF, Meroni SB. Participation of HIFs in the regulation of Sertoli cell lactate production. Biochimie 2017; 132:9-18. [PMID: 27750035 DOI: 10.1016/j.biochi.2016.10.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 10/12/2016] [Indexed: 12/19/2022]
Abstract
Hypoxia Inducible Factors (HIFs) are master regulators of glycolytic metabolism. HIFs consist of a constitutive HIFbeta (HIFβ) subunit and a HIFalpha (HIFα) subunit, whose half-life depends on prolyl-hydroxylases activity. Inhibition of prolyl-hydroxylases by hypoxia or transition metals, or augmentation of HIFα subunit levels by hormonal stimuli lead to a higher HIF transcriptional activity. On the other hand, it is well known that lactate produced by Sertoli cells is delivered to and used by germ cells as an energy substrate. The aim of this work was to investigate whether HIFs participate in the regulation of lactate production in rat Sertoli cells and whether they are involved in the FSH mechanism of action. In order to reach a higher HIF transcriptional activity, Sertoli cells were treated with CoCl2. We observed that a higher HIF transcriptional activity leads to an augmentation of: lactate production, glucose uptake and LDH activity. Besides, an increase in Glut1, Pkm2 and Ldha mRNA levels was observed. These findings suggested that HIFs may participate in the modulation of Sertoli cell nutritional function. As FSH regulates lactate production, we evaluated whether HIFs were involved in FSH action. Sertoli cells were stimulated with FSH in the absence or presence of LW6, a drug which promotes HIFα subunit degradation. On the one hand, we observed that FSH increases HIF1α protein, Hif1α and Hif2α mRNA levels and, on the other hand, that LW6 inhibits FSH-stimulated lactate production, glucose uptake, Glut1, Pkm2 and Ldha expression. It is proposed that HIFs are key components of the intricate pathways utilized by FSH to regulate the provision of lactate for germ cells. Considering that FSH is the master endocrine regulator of Sertoli cells, it is not surprising that this hormone may employ several regulatory mechanisms to fulfill the nourishing functions of this cell type.
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Affiliation(s)
- María Noel Galardo
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE) CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330, C1425EFD, Ciudad Autónoma de Buenos Aires, Argentina
| | - Agostina Gorga
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE) CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330, C1425EFD, Ciudad Autónoma de Buenos Aires, Argentina
| | - Joaquín Pedro Merlo
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE) CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330, C1425EFD, Ciudad Autónoma de Buenos Aires, Argentina
| | - Mariana Regueira
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE) CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330, C1425EFD, Ciudad Autónoma de Buenos Aires, Argentina
| | - Eliana Herminia Pellizzari
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE) CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330, C1425EFD, Ciudad Autónoma de Buenos Aires, Argentina
| | - Selva Beatriz Cigorraga
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE) CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330, C1425EFD, Ciudad Autónoma de Buenos Aires, Argentina
| | - María Fernanda Riera
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE) CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330, C1425EFD, Ciudad Autónoma de Buenos Aires, Argentina
| | - Silvina Beatriz Meroni
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE) CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330, C1425EFD, Ciudad Autónoma de Buenos Aires, Argentina.
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25
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Paik JY, Jung KH, Lee JH, Park JW, Lee KH. Reactive oxygen species-driven HIF1α triggers accelerated glycolysis in endothelial cells exposed to low oxygen tension. Nucl Med Biol 2016; 45:8-14. [PMID: 27835826 DOI: 10.1016/j.nucmedbio.2016.10.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 10/12/2016] [Accepted: 10/24/2016] [Indexed: 12/26/2022]
Abstract
Endothelial cells and their metabolic state regulate glucose transport into underlying tissues. Here, we show that low oxygen tension stimulates human umbilical vein endothelial cell 18F-fluorodeoxyglucose (18F-FDG) uptake and lactate production. This was accompanied by augmented hexokinase activity and membrane Glut-1, and increased accumulation of hypoxia-inducible factor-1α (HIF1α). Restoration of oxygen reversed the metabolic effect, but this was blocked by HIF1α stabilization. Hypoxia-stimulated 18F-FDG uptake was completely abrogated by silencing of HIF1α expression or by a specific inhibitor. There was a rapid and marked increase of reactive oxygen species (ROS) by hypoxia, and ROS scavenging or NADPH oxidase inhibition completely abolished hypoxia-stimulated HIF1α and 18F-FDG accumulation, placing ROS production upstream of HIF1α signaling. Hypoxia-stimulated HIF1α and 18F-FDG accumulation was blocked by the protein kinase C (PKC) inhibitor, staurosporine. The phosphatidylinositol 3-kinase (PI3K) inhibitor, wortmannin, blocked hypoxia-stimulated 18F-FDG uptake and attenuated hypoxia-responsive element binding of HIF1α without influencing its accumulation. Thus, ROS-driven HIF1α accumulation, along with PKC and PI3K signaling, play a key role in triggering accelerated glycolysis in endothelial cells under hypoxia, thereby contributing to 18F-FDG transport.
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Affiliation(s)
- Jin-Young Paik
- Department of Nuclear Medicine, Samsung Medical Center, Seoul, Republic of Korea
| | - Kyung-Ho Jung
- Department of Nuclear Medicine, Samsung Medical Center, Seoul, Republic of Korea; Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Jin-Hee Lee
- Department of Nuclear Medicine, Samsung Medical Center, Seoul, Republic of Korea; Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Jin-Won Park
- Department of Nuclear Medicine, Samsung Medical Center, Seoul, Republic of Korea; Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Kyung-Han Lee
- Department of Nuclear Medicine, Samsung Medical Center, Seoul, Republic of Korea; Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
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26
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Li L, Watson CJ, Dubourd M, Bruton A, Xu M, Cooke G, Baugh JA. HIF-1-Dependent TGM1 Expression is Associated with Maintenance of Airway Epithelial Junction Proteins. Lung 2016; 194:829-38. [PMID: 27423780 DOI: 10.1007/s00408-016-9918-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 07/02/2016] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Hypoxia has been implicated in the pathogenesis of many inflammatory and fibrotic lung diseases. The effect of hypoxia on epithelial junction protein expression is yet to be fully elucidated but evidence suggests a protective role for the hypoxia-inducible transcription factor HIF-1 in stabilising occludin. Transglutaminase 1 (TGM1) has been shown to stabilise endothelial and keratinocyte cell junctions, and while its expression and function have been mostly studied in the skin, recent studies have reported its expression in the lung. We hypothesised that TGM1 is a hypoxia-induced regulator of pulmonary epithelial junction protein stability, and the aim of this study was to investigate the regulation of TGM1 expression by hypoxia. METHODS Hypoxia-responsive genes were identified in human small airway epithelial cells (SAECs) by DNA microarray. TGM1 mRNA expression in SAECs was measured by quantitative real-time PCR. Protein expression of TGM1 and junction proteins was investigated by western blotting. Hypoxia-induced TGM1 was analysed by immunohistochemistry in vivo. The TGM1 gene promoter was investigated by luciferase assay. RESULTS In vitro exposure of SAECs to hypoxia induced a significant increase in TGM1 expression at both mRNA and protein levels. TGM1 was also significantly upregulated in hypoxic mouse lung epithelium. The hypoxia-responsive region was mapped to a HIF-1-responsive element. Inhibition of HIF-1 expression abolished hypoxia-induced promoter activation. Overexpression of TGM1 in lung epithelial cells or exposure of SAECs to hypoxia led to upregulated expression of junction proteins. CONCLUSION Herein we report that TGM1 is a HIF-1-regulated gene that is associated with the upregulation of airway epithelial junction proteins, supporting a protective role for HIF-1 in the lung. Interventions that augment the expression of TGM1 may provide useful therapeutic strategies for maintaining pulmonary epithelial integrity during lung injury.
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Affiliation(s)
- Lili Li
- UCD Conway Institute for Biomolecular and Biomedical Research, School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - Chris J Watson
- UCD Conway Institute for Biomolecular and Biomedical Research, School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland.,Centre for Experimental Medicine, Queen's University Belfast, Wellcome-Wolfson Building, Belfast, Northern Ireland, UK
| | - Mickael Dubourd
- UCD Conway Institute for Biomolecular and Biomedical Research, School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - Aine Bruton
- UCD Conway Institute for Biomolecular and Biomedical Research, School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - Maojia Xu
- UCD Conway Institute for Biomolecular and Biomedical Research, School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - Gordon Cooke
- UCD Conway Institute for Biomolecular and Biomedical Research, School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - John A Baugh
- UCD Conway Institute for Biomolecular and Biomedical Research, School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
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27
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Gill KS, Fernandes P, O'Donovan TR, McKenna SL, Doddakula KK, Power DG, Soden DM, Forde PF. Glycolysis inhibition as a cancer treatment and its role in an anti-tumour immune response. Biochim Biophys Acta Rev Cancer 2016; 1866:87-105. [PMID: 27373814 DOI: 10.1016/j.bbcan.2016.06.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 06/29/2016] [Accepted: 06/30/2016] [Indexed: 12/23/2022]
Abstract
Increased glycolysis is the main source of energy supply in cancer cells that use this metabolic pathway for ATP generation. Altered energy metabolism is a biochemical fingerprint of cancer cells that represents one of the "hallmarks of cancer". The immune system can prevent tumour growth by eliminating cancer cells but this editing process ultimately results in poorly immunogenic cells remaining allowing for unchallenged tumour growth. In this review we look at the glycolysis pathway as a target for cancer treatments. We also examine the interplay between the glycolysis modulation and the immune response as an anti-cancer therapy.
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Affiliation(s)
- Kheshwant S Gill
- Cork Cancer Research Centre, Western Gateway Building, University College Cork, Cork, Ireland; Cardiothoracic Surgery Department, Cork University Hospital, Cork, Ireland
| | - Philana Fernandes
- Cork Cancer Research Centre, Western Gateway Building, University College Cork, Cork, Ireland
| | - Tracey R O'Donovan
- Cork Cancer Research Centre, Western Gateway Building, University College Cork, Cork, Ireland
| | - Sharon L McKenna
- Cork Cancer Research Centre, Western Gateway Building, University College Cork, Cork, Ireland
| | | | - Derek G Power
- Cork Cancer Research Centre, Western Gateway Building, University College Cork, Cork, Ireland; Department of Medical Oncology, Mercy University Hospital, Grenville Place, Cork, Ireland
| | - Declan M Soden
- Cork Cancer Research Centre, Western Gateway Building, University College Cork, Cork, Ireland
| | - Patrick F Forde
- Cork Cancer Research Centre, Western Gateway Building, University College Cork, Cork, Ireland.
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28
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McGillick EV, Orgeig S, Morrison JL. Regulation of lung maturation by prolyl hydroxylase domain inhibition in the lung of the normally grown and placentally restricted fetus in late gestation. Am J Physiol Regul Integr Comp Physiol 2016; 310:R1226-43. [PMID: 26936783 DOI: 10.1152/ajpregu.00469.2015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 02/23/2016] [Indexed: 12/28/2022]
Abstract
Intrauterine growth restriction induced by placental restriction (PR) in sheep leads to chronic hypoxemia and reduced surfactant maturation. The underlying molecular mechanism involves altered regulation of hypoxia signaling by increased prolyl hydroxylase domain (PHD) expression. Here, we evaluated the effect of intratracheal administration of the PHD inhibitor dimethyloxalylglycine (DMOG) on functional, molecular, and structural determinants of lung maturation in the control and PR sheep fetus. There was no effect of DMOG on fetal blood pressure or fetal breathing movements. DMOG reduced lung expression of genes regulating hypoxia signaling (HIF-3α, ACE1), antioxidant defense (CAT), lung liquid reabsorption (SCNN1-A, ATP1-A1, AQP-1, AQP-5), and surfactant maturation (SFTP-A, SFTP-B, SFTP-C, PCYT1A, LPCAT, ABCA3, LAMP3) in control fetuses. There were very few effects of DMOG on gene expression in the PR fetal lung (reduced lung expression of angiogenic factor ADM, water channel AQP-5, and increased expression of glucose transporter SLC2A1). DMOG administration in controls reduced total lung lavage phosphatidylcholine to the same degree as in PR fetuses. These changes appear to be regulated at the molecular level as there was no effect of DMOG on the percent tissue, air space, or numerical density of SFTP-B positive cells in the control and PR lung. Hence, DMOG administration mimics the effects of PR in reducing surfactant maturation in the lung of control fetuses. The limited responsiveness of the PR fetal lung suggests a potential biochemical limit or reduced plasticity to respond to changes in regulation of hypoxia signaling following exposure to chronic hypoxemia in utero.
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Affiliation(s)
- Erin V McGillick
- Early Origins of Adult Health Research Group and Molecular and Evolutionary Physiology of the Lung Laboratory, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
| | - Sandra Orgeig
- Molecular and Evolutionary Physiology of the Lung Laboratory, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
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29
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Kerridge C, Kozlova DI, Nalivaeva NN, Turner AJ. Hypoxia Affects Neprilysin Expression Through Caspase Activation and an APP Intracellular Domain-dependent Mechanism. Front Neurosci 2015; 9:426. [PMID: 26617481 PMCID: PMC4643132 DOI: 10.3389/fnins.2015.00426] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 10/20/2015] [Indexed: 12/12/2022] Open
Abstract
While gene mutations in the amyloid precursor protein (APP) and the presenilins lead to an accumulation of the amyloid β-peptide (Aβ) in the brain causing neurodegeneration and familial Alzheimer's disease (AD), over 95% of all AD cases are sporadic. Despite the pathologies being indistinguishable, relatively little is known about the mechanisms affecting generation of Aβ in the sporadic cases. Vascular disorders such as ischaemia and stroke are well established risk factors for the development of neurodegenerative diseases and systemic hypoxic episodes have been shown to increase Aβ production and accumulation. We have previously shown that hypoxia causes a significant decrease in the expression of the major Aβ-degrading enzyme neprilysin (NEP) which might deregulate Aβ clearance. Aβ itself is derived from the transmembrane APP along with several other biologically active metabolites including the C-terminal fragment (CTF) termed the APP intracellular domain (AICD), which regulates the expression of NEP and some other genes in neuronal cells. Here we show that in hypoxia there is a significantly increased expression of caspase-3, 8, and 9 in human neuroblastoma NB7 cells, which can degrade AICD. Using chromatin immunoprecipitation we have revealed that there was also a reduction of AICD bound to the NEP promoter region which underlies the decreased expression and activity of the enzyme under hypoxic conditions. Incubation of the cells with a caspase-3 inhibitor Z-DEVD-FMK could rescue the effect of hypoxia on NEP activity protecting the levels of AICD capable of binding the NEP promoter. These data suggest that activation of caspases might play an important role in regulation of NEP levels in the brain under pathological conditions such as hypoxia and ischaemia leading to a deficit of Aβ clearance and increasing the risk of development of AD.
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Affiliation(s)
- Caroline Kerridge
- Faculty of Biological Sciences, School of Molecular and Cellular Biology, University of Leeds Leeds, UK ; Neuroscience, Eli Lilly and Company Limited, Lilly Research Centre Surrey, UK
| | - Daria I Kozlova
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences St. Petersburg, Russia
| | - Natalia N Nalivaeva
- Faculty of Biological Sciences, School of Molecular and Cellular Biology, University of Leeds Leeds, UK ; I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences St. Petersburg, Russia
| | - Anthony J Turner
- Faculty of Biological Sciences, School of Molecular and Cellular Biology, University of Leeds Leeds, UK
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30
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Liemburg-Apers DC, Willems PHGM, Koopman WJH, Grefte S. Interactions between mitochondrial reactive oxygen species and cellular glucose metabolism. Arch Toxicol 2015; 89:1209-26. [PMID: 26047665 PMCID: PMC4508370 DOI: 10.1007/s00204-015-1520-y] [Citation(s) in RCA: 229] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 04/27/2015] [Indexed: 12/20/2022]
Abstract
Mitochondrial reactive oxygen species (ROS) production and detoxification are tightly balanced. Shifting this balance enables ROS to activate intracellular signaling and/or induce cellular damage and cell death. Increased mitochondrial ROS production is observed in a number of pathological conditions characterized by mitochondrial dysfunction. One important hallmark of these diseases is enhanced glycolytic activity and low or impaired oxidative phosphorylation. This suggests that ROS is involved in glycolysis (dys)regulation and vice versa. Here we focus on the bidirectional link between ROS and the regulation of glucose metabolism. To this end, we provide a basic introduction into mitochondrial energy metabolism, ROS generation and redox homeostasis. Next, we discuss the interactions between cellular glucose metabolism and ROS. ROS-stimulated cellular glucose uptake can stimulate both ROS production and scavenging. When glucose-stimulated ROS production, leading to further glucose uptake, is not adequately counterbalanced by (glucose-stimulated) ROS scavenging systems, a toxic cycle is triggered, ultimately leading to cell death. Here we inventoried the various cellular regulatory mechanisms and negative feedback loops that prevent this cycle from occurring. It is concluded that more insight in these processes is required to understand why they are (un)able to prevent excessive ROS production during various pathological conditions in humans.
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Affiliation(s)
- Dania C. Liemburg-Apers
- />Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Medical Center (RUMC), P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Peter H. G. M. Willems
- />Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Medical Center (RUMC), P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Werner J. H. Koopman
- />Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Medical Center (RUMC), P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Sander Grefte
- />Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Medical Center (RUMC), P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
- />Department of Human and Animal Physiology, Wageningen University, P.O. Box 338, 6700 AH Wageningen, The Netherlands
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Structure and function of BCRP, a broad specificity transporter of xenobiotics and endobiotics. Arch Toxicol 2014; 88:1205-48. [DOI: 10.1007/s00204-014-1224-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 03/06/2014] [Indexed: 12/20/2022]
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Gille T, Randrianarison-Pellan N, Goolaerts A, Dard N, Uzunhan Y, Ferrary E, Hummler E, Clerici C, Planès C. Hypoxia-induced inhibition of epithelial Na(+) channels in the lung. Role of Nedd4-2 and the ubiquitin-proteasome pathway. Am J Respir Cell Mol Biol 2014; 50:526-37. [PMID: 24093724 DOI: 10.1165/rcmb.2012-0518oc] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Transepithelial sodium transport via alveolar epithelial Na(+) channels (ENaC) and Na(+),K(+)-ATPase constitutes the driving force for removal of alveolar edema fluid. Alveolar hypoxia associated with pulmonary edema may impair ENaC activity and alveolar Na(+) absorption through a decrease of ENaC subunit expression at the apical membrane of alveolar epithelial cells (AECs). Here, we investigated the mechanism(s) involved in this process in vivo in the β-Liddle mouse strain mice carrying a truncation of β-ENaC C-terminus abolishing the interaction between β-ENaC and the ubiquitin protein-ligase Nedd4-2 that targets the channel for endocytosis and degradation and in vitro in rat AECs. Hypoxia (8% O2 for 24 h) reduced amiloride-sensitive alveolar fluid clearance by 69% in wild-type mice but had no effect in homozygous mutated β-Liddle littermates. In vitro, acute exposure of AECs to hypoxia (0.5-3% O2 for 1-6 h) rapidly decreased transepithelial Na(+) transport as assessed by equivalent short-circuit current Ieq and the amiloride-sensitive component of Na(+) current across the apical membrane, reflecting ENaC activity. Hypoxia induced a decrease of ENaC subunit expression in the apical membrane of AECs with no change in intracellular expression and induced a 2-fold increase in α-ENaC polyubiquitination. Hypoxic inhibition of amiloride-sensitive Ieq was fully prevented by preincubation with the proteasome inhibitors MG132 and lactacystin or with the antioxidant N-acetyl-cysteine. Our data strongly suggest that Nedd4-2-mediated ubiquitination of ENaC leading to endocytosis and degradation of apical Na(+) channels is a key feature of hypoxia-induced inhibition of transepithelial alveolar Na(+) transport.
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Affiliation(s)
- Thomas Gille
- 1 Université Paris 13, Sorbonne Paris Cité, Laboratoire Réponses Cellulaires et Fonctionnelles à l'Hypoxie (EA 2363), Bobigny, France
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Siervo M, Riley HL, Fernandez BO, Leckstrom CA, Martin DS, Mitchell K, Levett DZH, Montgomery HE, Mythen MG, Grocott MPW, Feelisch M. Effects of prolonged exposure to hypobaric hypoxia on oxidative stress, inflammation and gluco-insular regulation: the not-so-sweet price for good regulation. PLoS One 2014; 9:e94915. [PMID: 24733551 PMCID: PMC3986261 DOI: 10.1371/journal.pone.0094915] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 03/21/2014] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVES The mechanisms by which low oxygen availability are associated with the development of insulin resistance remain obscure. We thus investigated the relationship between such gluco-insular derangements in response to sustained (hypobaric) hypoxemia, and changes in biomarkers of oxidative stress, inflammation and counter-regulatory hormone responses. METHODS After baseline testing in London (75 m), 24 subjects ascended from Kathmandu (1,300 m) to Everest Base Camp (EBC;5,300 m) over 13 days. Of these, 14 ascended higher, with 8 reaching the summit (8,848 m). Assessments were conducted at baseline, during ascent to EBC, and 1, 6 and 8 week(s) thereafter. Changes in body weight and indices of gluco-insular control were measured (glucose, insulin, C-Peptide, homeostasis model assessment of insulin resistance [HOMA-IR]) along with biomarkers of oxidative stress (4-hydroxy-2-nonenal-HNE), inflammation (Interleukin-6 [IL-6]) and counter-regulatory hormones (glucagon, adrenalin, noradrenalin). In addition, peripheral oxygen saturation (SpO2) and venous blood lactate concentrations were determined. RESULTS SpO2 fell significantly from 98.0% at sea level to 82.0% on arrival at 5,300 m. Whilst glucose levels remained stable, insulin and C-Peptide concentrations increased by >200% during the last 2 weeks. Increases in fasting insulin, HOMA-IR and glucagon correlated with increases in markers of oxidative stress (4-HNE) and inflammation (IL-6). Lactate levels progressively increased during ascent and remained significantly elevated until week 8. Subjects lost on average 7.3 kg in body weight. CONCLUSIONS Sustained hypoxemia is associated with insulin resistance, whose magnitude correlates with the degree of oxidative stress and inflammation. The role of 4-HNE and IL-6 as key players in modifying the association between sustained hypoxia and insulin resistance merits further investigation.
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Affiliation(s)
- Mario Siervo
- Human Nutrition Research Centre, Institute for Ageing and Health, Newcastle University, Newcastle on Tyne, United Kingdom
| | - Heather L. Riley
- Warwick Systems Biology Centre, University of Warwick, Coventry, United Kingdom
| | - Bernadette O. Fernandez
- Warwick Medical School, University of Warwick, Coventry, United Kingdom
- University of Southampton, Clinical & Experimental Sciences, Faculty of Medicine, Southampton General Hospital, Southampton, United Kingdom
| | - Carl A. Leckstrom
- Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Daniel S. Martin
- Centre for Altitude Space and Extreme Environment Medicine, Portex Unit, UCL Institute of Child Health, London, United Kingdom
- Division of Surgery and Interventional Science, University College London, Royal Free Hospital, London, United Kingdom
| | - Kay Mitchell
- Centre for Altitude Space and Extreme Environment Medicine, Portex Unit, UCL Institute of Child Health, London, United Kingdom
- University Hospital Southampton NHS Foundation Trust, Southampton General Hospital, Southampton, United Kingdom
| | - Denny Z. H. Levett
- Centre for Altitude Space and Extreme Environment Medicine, Portex Unit, UCL Institute of Child Health, London, United Kingdom
- University Hospital Southampton NHS Foundation Trust, Southampton General Hospital, Southampton, United Kingdom
- Southampton NIHR Respiratory Biomedical Research Unit, Southampton, United Kingdom
| | - Hugh E. Montgomery
- Centre for Altitude Space and Extreme Environment Medicine, Portex Unit, UCL Institute of Child Health, London, United Kingdom
| | - Monty G. Mythen
- Centre for Altitude Space and Extreme Environment Medicine, Portex Unit, UCL Institute of Child Health, London, United Kingdom
| | - Michael P. W. Grocott
- University of Southampton, Clinical & Experimental Sciences, Faculty of Medicine, Southampton General Hospital, Southampton, United Kingdom
- Centre for Altitude Space and Extreme Environment Medicine, Portex Unit, UCL Institute of Child Health, London, United Kingdom
- University Hospital Southampton NHS Foundation Trust, Southampton General Hospital, Southampton, United Kingdom
- Southampton NIHR Respiratory Biomedical Research Unit, Southampton, United Kingdom
| | - Martin Feelisch
- Warwick Systems Biology Centre, University of Warwick, Coventry, United Kingdom
- Warwick Medical School, University of Warwick, Coventry, United Kingdom
- University of Southampton, Clinical & Experimental Sciences, Faculty of Medicine, Southampton General Hospital, Southampton, United Kingdom
- Southampton NIHR Respiratory Biomedical Research Unit, Southampton, United Kingdom
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Lottes RG, Newton DA, Spyropoulos DD, Baatz JE. Alveolar type II cells maintain bioenergetic homeostasis in hypoxia through metabolic and molecular adaptation. Am J Physiol Lung Cell Mol Physiol 2014; 306:L947-55. [PMID: 24682450 DOI: 10.1152/ajplung.00298.2013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Although many lung diseases are associated with hypoxia, alveolar type II epithelial (ATII) cell impairment, and pulmonary surfactant dysfunction, the effects of O(2) limitation on metabolic pathways necessary to maintain cellular energy in ATII cells have not been studied extensively. This report presents results of targeted assays aimed at identifying specific metabolic processes that contribute to energy homeostasis using primary ATII cells and a model ATII cell line, mouse lung epithelial 15 (MLE-15), cultured in normoxic and hypoxic conditions. MLEs cultured in normoxia demonstrated a robust O(2) consumption rate (OCR) coupled to ATP generation and limited extracellular lactate production, indicating reliance on oxidative phosphorylation for ATP production. Pharmacological uncoupling of respiration increased OCR in normoxic cultures to 175% of basal levels, indicating significant spare respiratory capacity. However, when exposed to hypoxia for 20 h, basal O(2) consumption fell to 60% of normoxic rates, and cells maintained only ∼50% of normoxic spare respiratory capacity, indicating suppression of mitochondrial function, although intracellular ATP levels remained at near normoxic levels. Moreover, while hypoxic exposure stimulated glycogen synthesis and storage in MLE-15, glycolytic rate (as measured by lactate generation) was not significantly increased in the cells, despite enhanced expression of several enzymes related to glycolysis. These results were largely recapitulated in murine primary ATII, demonstrating MLE-15 suitability for modeling ATII metabolism. The ability of ATII cells to maintain ATP levels in hypoxia without enhancing glycolysis suggests that these cells are exceptionally efficient at conserving ATP to maintain bioenergetic homeostasis under O(2) limitation.
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Affiliation(s)
- Robyn G Lottes
- Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolia; and
| | - Danforth A Newton
- Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolia; and
| | - Demetri D Spyropoulos
- Department of Pathology & Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolia
| | - John E Baatz
- Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolia; and
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Falcon BL, Stewart J, Ezell S, Hanson J, Wijsman J, Ye X, Westin E, Donoho G, Credille K, Uhlik MT. High-content multiplexed tissue imaging and quantification for cancer drug discovery. Drug Discov Today 2013; 18:510-22. [DOI: 10.1016/j.drudis.2012.08.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 07/11/2012] [Accepted: 08/23/2012] [Indexed: 01/01/2023]
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Resistance to hypoxia-induced necroptosis is conferred by glycolytic pyruvate scavenging of mitochondrial superoxide in colorectal cancer cells. Cell Death Dis 2013; 4:e622. [PMID: 23640464 PMCID: PMC3674358 DOI: 10.1038/cddis.2013.149] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Cancer cells may survive under oxygen and nutrient deprivation by metabolic reprogramming for high levels of anaerobic glycolysis, which contributes to tumor growth and drug resistance. Abnormally expressed glucose transporters (GLUTs) are colocalized with hypoxia (Hx) inducible factor (HIF)1α in peri-necrotic regions in human colorectal carcinoma. However, the underlying mechanisms of anti-necrotic resistance conferred by glucose metabolism in hypoxic cancer cells remain poorly understood. Our aim was to investigate signaling pathways of Hx-induced necroptosis and explore the role of glucose pyruvate metabolite in mechanisms of death resistance. Human colorectal carcinoma cells were Hx exposed with or without glucose, and cell necroptosis was examined by receptor-interacting protein (RIP)1/3 kinase immunoprecipitation and (32)P kinase assays. Our results showed increased RIP1/3 complex formation and phosphorylation in hypoxic, but not normoxic cells in glucose-free media. Blocking RIP1 signaling, by necrostatin-1 or gene silencing, decreased lactodehydrogenase (LDH) leakage and plasma membrane disintegration. Generation of mitochondrial superoxide was noted after hypoxic challenge; its reduction by antioxidants inhibited RIP signaling and cell necrosis. Supplementation of glucose diminished the RIP-dependent LDH leakage and morphological damage in hypoxic cells, whereas non-metabolizable sugar analogs did not. Hypoxic cells given glucose showed nuclear translocation of HIF1α associated with upregulation of GLUT-1 and GLUT-4 expression, as well as increase of intracellular ATP, pyruvate and lactate levels. The glucose-mediated death resistance was ablated by iodoacetate (an inhibitor to glyceraldehyde-3-phosphate dehydrogenase), but not by UK5099 (an inhibitor to mitochondrial pyruvate carrier), suggesting that glycolytic pathway was involved in anti-necrotic mechanism. Lastly, replacing glucose with cell-permeable pyruvate derivative also led to decrease of Hx-induced necroptosis by suppression of mitochondrial superoxide in an energy-independent manner. In conclusion, glycolytic metabolism confers resistance to RIP-dependent necroptosis in hypoxic cancer cells partly through pyruvate scavenging of mitochondrial free radicals.
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Veith C, Schmitt S, Veit F, Dahal BK, Wilhelm J, Klepetko W, Marta G, Seeger W, Schermuly RT, Grimminger F, Ghofrani HA, Fink L, Weissmann N, Kwapiszewska G. Cofilin, a hypoxia-regulated protein in murine lungs identified by 2DE: Role of the cytoskeletal protein cofilin in pulmonary hypertension. Proteomics 2013; 13:75-88. [DOI: 10.1002/pmic.201200206] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2012] [Revised: 10/08/2012] [Accepted: 10/29/2012] [Indexed: 01/18/2023]
Affiliation(s)
- Christine Veith
- Universities of Giessen and Marburg Lung Center (UGMLC); Giessen Germany
| | - Sigrid Schmitt
- Department of Biochemistry; University of Giessen; Giessen Germany
| | - Florian Veit
- Universities of Giessen and Marburg Lung Center (UGMLC); Giessen Germany
| | - Bhola Kumar Dahal
- Universities of Giessen and Marburg Lung Center (UGMLC); Giessen Germany
| | - Jochen Wilhelm
- Universities of Giessen and Marburg Lung Center (UGMLC); Giessen Germany
| | - Walter Klepetko
- Department of Cardiac Surgery; University of Vienna; Vienna Austria
| | - Gabriel Marta
- Department of Cardiac Surgery; University of Vienna; Vienna Austria
| | - Werner Seeger
- Universities of Giessen and Marburg Lung Center (UGMLC); Giessen Germany
| | | | | | | | - Ludger Fink
- Universities of Giessen and Marburg Lung Center (UGMLC); Giessen Germany
| | - Norbert Weissmann
- Universities of Giessen and Marburg Lung Center (UGMLC); Giessen Germany
| | - Grazyna Kwapiszewska
- Universities of Giessen and Marburg Lung Center (UGMLC); Giessen Germany
- Ludwig Boltzmann Institute for Lung Vascular Research; Graz Austria
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Watanabe K, Iwahara C, Nakayama H, Iwabuchi K, Matsukawa T, Yokoyama K, Yamaguchi K, Kamiyama Y, Inada E. Sevoflurane suppresses tumour necrosis factor-α-induced inflammatory responses in small airway epithelial cells after anoxia/reoxygenation. Br J Anaesth 2013; 110:637-45. [PMID: 23295714 DOI: 10.1093/bja/aes469] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Lung ischaemia-reperfusion (I/R) injury is correlated with poor clinical outcome. The inflammatory cytokines interleukin (IL)-6, IL-8, and monocyte chemotactic protein-1 (MCP-1) are produced by pulmonary epithelial cells during lung transplantation and are considered to be involved in I/R injury. The volatile anaesthetic sevoflurane has been shown to exert a protective effect on I/R injury in various organs. We investigated the effect of sevoflurane on the inflammatory functions of pulmonary epithelial cells in vitro. METHODS Human normal small airway epithelial cells (SAEC) were incubated under anoxic conditions for 24 h with or without sevoflurane and then stimulated with tumour necrosis factor (TNF)-α under hyperoxic conditions for 5 h with or without sevoflurane. After incubation, IL-6, IL-8, and MCP-1 mRNA expression was analysed by quantitative real-time RT-PCR. The production of IL-6, IL-8, and MCP-1 was assayed by enzyme-linked immunosorbent assay, the effects of sevoflurane on inflammatory gene expression were examined by DNA microarray analysis, and the effects of sevoflurane on NF-κB-mediated inflammatory cytokine production were examined by immunoblotting. RESULTS Sevoflurane suppressed TNF-α-induced IL-6, IL-8, and MCP-1 gene expression and the production of IL-6 and IL-8 in SAEC under anoxia/reoxygenation conditions. DNA microarray analysis indicated that sevoflurane modulated NF-κB-related gene expression. Sevoflurane significantly inhibited TNF-α-induced translocation of p65 NF-κB into the nucleus. Sevoflurane enhanced TNF-α-induced gene expression of inhibitor κB (IκB) but not of NF-κB. CONCLUSIONS Sevoflurane suppressed the NF-κB-mediated production of pulmonary epithelial cell-derived inflammatory cytokines, including IL-6 and IL-8, which are capable of causing I/R injury.
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Affiliation(s)
- K Watanabe
- Department of Anesthesiology and Pain Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Tokyo 113-8421, Japan
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Abstract
PURPOSE The aim of this study was to establish a relationship between hypoxic stress and the expression of ΔNp63α in an established rabbit contact lens model and in cultured corneal epithelial cells. METHODS New Zealand white rabbits were fit in one eye with either a non-oxygen transmissible or hyper-oxygen-permeable rigid contact lens for 24 hrs of wear; the contralateral eye was used as a control. All the rabbits underwent a bilateral nictitating membranectomy to facilitate lens retention. ΔNp63α expression was analyzed by immunofluorescence and western blot. Telomerase-immortalized human corneal epithelial cells (hTCEpi) were grown in serum-free media and treated with the hypoxia-mimetic cobalt chloride to simulate hypoxia for 6 hrs (short term) or 24 hrs (prolonged). Transcriptional activity and protein levels were assessed using luciferase reporter assays, reverse transcription polymerase chain reaction, and western blot. Cell viability was assessed by live/dead assay. RESULTS Compared with the non-lens wearing eye, 24 hrs of non-oxygen transmissible lens wear in vivo decreased ΔNp63α protein levels in both the limbal and central corneal epithelium; this decrease was not found in the hyper-oxygen transmissible lens group. In hTCEpi cells in vitro, hypoxia increased the activity of the ΔN promoter but reduced the levels of ΔNp63α mRNA after 24 hrs of prolonged culture. Similarly, ΔNp63α expression levels were unaffected from short-term exposure but decreased after 24 hrs. Live/dead assay confirmed the presence of viable cells after CoCl2 treatment at 6- and 24-hr time points. Cells treated for 24 hrs were viable but were smaller and rounded with signs of membrane blebbing, consistent with early stages of apoptosis. CONCLUSIONS Hypoxic stress induced by either prolonged wear of a nonoxygen transmissible lens in vivo or hypoxic-mimic conditions by cobalt chloride in vitro downregulates ΔNp63α in the corneal epithelium. The loss of ΔNp63α in response to hypoxic stress may contribute to the disruption of normal renewal mechanisms reported with low oxygen transmissible contact lens wear and prolonged eyelid closure.
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Ho JJD, Man HSJ, Marsden PA. Nitric oxide signaling in hypoxia. J Mol Med (Berl) 2012; 90:217-31. [DOI: 10.1007/s00109-012-0880-5] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 02/03/2012] [Accepted: 02/06/2012] [Indexed: 01/06/2023]
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Munksgaard Persson M, Johansson ME, Monsef N, Planck M, Beckman S, Seckl MJ, Rönnstrand L, Påhlman S, Pettersson HM. HIF-2α expression is suppressed in SCLC cells, which survive in moderate and severe hypoxia when HIF-1α is repressed. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 180:494-504. [PMID: 22115707 DOI: 10.1016/j.ajpath.2011.10.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 09/16/2011] [Accepted: 10/11/2011] [Indexed: 12/27/2022]
Abstract
Small cell lung carcinoma (SCLC) is extremely aggressive and frequently metastasizes widely in its early stage. Because tumor hypoxia is related to aggressive tumor behavior and the hypoxic adaptation of SCLC is poorly documented, we stained SCLC tumors arranged in a tissue microarray for hypoxia-inducible factor (HIF)-1α and HIF-2α proteins. We found an overall lack of HIF-2α protein expression, which was confirmed in large tumor sections. HIF-1α protein was strongly expressed in most tumors, frequently adjacent to necrotic regions. In concordance, cultured SCLC but not non-small cell lung carcinoma cells showed no or extremely low levels of HIF-2α mRNA and no HIF-2α protein at hypoxia. HIF-1α was stabilized after 4 hours at hypoxia, and its accumulation increased up to 96 hours. SCLC cells survived well and showed net proliferation and low cell death in modest (1% oxygen) and severe (0.1% oxygen) hypoxia. HIF-1α repression virtually did not influence cell death or viability despite reduced levels of hypoxia-inducible genes, such as BNIP3 and BNIP3L. At 1% oxygen no increased autophagy (LC3B-II activation) or NF-κB signaling were detected, whereas the unfolded protein response was activated at severe hypoxia. Our data indicate that HIFs are not exclusively required for SCLC cell survival at modest or severe hypoxia and that additional, yet uncharacterized, hypoxia-driven adaptation pathways may become activated.
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Affiliation(s)
- Matilda Munksgaard Persson
- Center for Molecular Pathology, Department of Laboratory Medicine, CREATE Health, Lund University, Skåne University Hospital, Malmö, Sweden
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Velázque-Amado RM, Escamilla-Chimal EG, Fanjul-Moles ML. Daily Light-Dark Cycles Influence Hypoxia-Inducible Factor 1 and Heat Shock Protein Levels in the Pacemakers of Crayfish. Photochem Photobiol 2011; 88:81-9. [DOI: 10.1111/j.1751-1097.2011.01012.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Gorospe M, Tominaga K, Wu X, Fähling M, Ivan M. Post-Transcriptional Control of the Hypoxic Response by RNA-Binding Proteins and MicroRNAs. Front Mol Neurosci 2011; 4:7. [PMID: 21747757 PMCID: PMC3130151 DOI: 10.3389/fnmol.2011.00007] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 06/17/2011] [Indexed: 01/08/2023] Open
Abstract
Mammalian gene expression patterns change profoundly in response to low oxygen levels. These changes in gene expression programs are strongly influenced by post-transcriptional mechanisms mediated by mRNA-binding factors: RNA-binding proteins (RBPs) and microRNAs (miRNAs). Here, we review the RBPs and miRNAs that modulate mRNA turnover and translation in response to hypoxic challenge. RBPs such as HuR (human antigen R), PTB (polypyrimidine tract-binding protein), heterogeneous nuclear ribonucleoproteins (hnRNPs), tristetraprolin, nucleolin, iron-response element-binding proteins (IRPs), and cytoplasmic polyadenylation-element-binding proteins (CPEBs), selectively bind to numerous hypoxia-regulated transcripts and play a major role in establishing hypoxic gene expression patterns. MiRNAs including miR-210, miR-373, and miR-21 associate with hypoxia-regulated transcripts and further modulate the levels of the encoded proteins to implement the hypoxic gene expression profile. We discuss the potent regulation of hypoxic gene expression by RBPs and miRNAs and their integrated actions in the cellular hypoxic response.
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Affiliation(s)
- Myriam Gorospe
- Laboratory of Molecular Biology and Immunology, National Institute on Aging-Intramural Research Program, National Institutes of HealthBaltimore, MD, USA
| | - Kumiko Tominaga
- Laboratory of Molecular Biology and Immunology, National Institute on Aging-Intramural Research Program, National Institutes of HealthBaltimore, MD, USA
| | - Xue Wu
- Department of Medicine, Indiana University School of MedicineIndianapolis, IN, USA
| | - Michael Fähling
- Institut für Vegetative Physiologie, Campus Charité Mitte, Charité – Universitätsmedizin BerlinBerlin, Germany
| | - Mircea Ivan
- Department of Medicine, Indiana University School of MedicineIndianapolis, IN, USA
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Ito Y, Ahmad A, Kewley E, Mason RJ. Hypoxia-inducible factor regulates expression of surfactant protein in alveolar type II cells in vitro. Am J Respir Cell Mol Biol 2011; 45:938-45. [PMID: 21454802 DOI: 10.1165/rcmb.2011-0052oc] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Alveolar type II (ATII) cells cultured at an air-liquid (A/L) interface maintain differentiation, but they lose these properties when they are submerged. Others showed that an oxygen tension gradient develops in the culture medium as ATII cells consume oxygen. Therefore, we wondered whether hypoxia inducible factor (HIF) signaling could explain differences in the phenotypes of ATII cells cultured under A/L interface or submerged conditions. ATII cells were isolated from male Sprague-Dawley rats and cultured on inserts coated with a mixture of rat-tail collagen and Matrigel, in medium including 5% rat serum and 10 ng/ml keratinocyte growth factor, with their apical surfaces either exposed to air or submerged. The A/L interface condition maintained the expression of surfactant proteins, whereas that expression was down-regulated under the submerged condition, and the effect was rapid and reversible. Under submerged conditions, there was an increase in HIF1α and HIF2α in nuclear extracts, mRNA levels of HIF inducible genes, vascular endothelial growth factor, glucose transporter-1 (GLUT1), and the protein level of pyruvate dehydrogenase kinase isozyme-1. The expression of surfactant proteins was suppressed and GLUT1 mRNA levels were induced when cells were cultured with 1 mM dimethyloxalyl glycine. The expression of surfactant proteins was restored under submerged conditions with supplemented 60% oxygen. HIF signaling and oxygen tension at the surface of cells appears to be important in regulating the phenotype of rat ATII cells.
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Affiliation(s)
- Yoko Ito
- Department of Medicine, National Jewish Health, Denver, CO 80206, USA.
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Grek CL, Newton DA, Spyropoulos DD, Baatz JE. Hypoxia up-regulates expression of hemoglobin in alveolar epithelial cells. Am J Respir Cell Mol Biol 2010; 44:439-47. [PMID: 20508070 DOI: 10.1165/rcmb.2009-0307oc] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Alveolar epithelial cells are directly exposed to acute and chronic fluctuations in alveolar oxygen tension. Previously, we found that the oxygen-binding protein hemoglobin is expressed in alveolar Type II cells (ATII). Here, we report that ATII cells also express a number of highly specific transcription factors and other genes normally associated with hemoglobin biosynthesis in erythroid precursors. Because hypoxia-inducible factors (HIFs) were shown to play a role in hypoxia-induced changes in ATII homeostasis, we hypothesized that the hypoxia-induced increase in intracellular HIF exerts a concomitant effect on ATII hemoglobin expression. Treatment of cells from the ATII-like immortalized mouse lung epithelial cell line-15 (MLE-15) with hypoxia for 20 hours resulted in dramatic increases in cellular levels of HIF-2α protein and parallel significant increases in hemoglobin messenger RNA (mRNA) and protein expression, as compared with that of control cells cultured in normoxia. Significant increases in the mRNA of globin-associated transcription factors were also observed, and RNA interference (RNAi) experiments demonstrated that the expression of hemoglobin is at least partially dependent on the cellular levels of globin-associated transcription factor isoform 1 (GATA-1). Conversely, levels of prosurfactant proteins B and C significantly decreased in the same cells after exposure to hypoxia. The treatment of MLE-15 cells cultured in normoxia with prolyl 4-hydroxylase inhibitors, which mimic the effects of hypoxia, resulted in increases of hemoglobin and decreases of surfactant proteins. Taken together, these results suggest a relationship between hypoxia, HIFs, and the expression of hemoglobin, and imply that hemoglobin may be involved in the oxygen-sensing pathway in alveolar epithelial cells.
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Affiliation(s)
- Christina L Grek
- Department of Pediatrics and Neonatology, Medical University of South Carolina, Charleston, SC 29425, USA.
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Abstract
In cells responding to low oxygen levels, gene expression patterns are strongly influenced by post-transcriptional processes. RNA-binding proteins (RBPs) are pivotal regulators of gene expression in response to numerous stresses, including hypoxia. Here, we review the RBPs that modulate mRNA turnover and translation in response to hypoxic challenge. The RBPs HuR (human antigen R) and PTB (polypyrimidine tract-binding protein) associate with mRNAs encoding hypoxia-response proteins such as HIF-1α and VEGF mRNAs, enhance their expression after hypoxia and play a major role in establishing hypoxic gene expression patterns. Additional RBPs such as iron-response element-binding proteins (IRPs), cytoplasmic polyadenylation-element-binding proteins (CPEBs) and several heterogeneous nuclear ribonucleoproteins (hnRNPs) also bind to hypoxia-regulated transcripts and modulate the levels of the encoded proteins. We discuss the efficient regulation of hypoxic gene expression by RBPs and the mounting interest in targeting hypoxia-regulatory RBPs in diseases with aberrant hypoxic responses.
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Affiliation(s)
- Kiyoshi Masuda
- Laboratory of Cellular and Molecular Biology, National Institute on Aging-Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
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Shukla D, Saxena S, Jayamurthy P, Sairam M, Singh M, Jain SK, Bansal A, Ilavazaghan G. Hypoxic Preconditioning with Cobalt Attenuates Hypobaric Hypoxia-Induced Oxidative Damage in Rat Lungs. High Alt Med Biol 2009; 10:57-69. [DOI: 10.1089/ham.2008.1028] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Dhananjay Shukla
- Defence Institute of Physiology & Allied Sciences, Defence Research and Development Organization, Lucknow Road, Timarpur, Delhi 110054, India
| | - Saurabh Saxena
- Defence Institute of Physiology & Allied Sciences, Defence Research and Development Organization, Lucknow Road, Timarpur, Delhi 110054, India
| | - Purushotman Jayamurthy
- Defence Institute of Physiology & Allied Sciences, Defence Research and Development Organization, Lucknow Road, Timarpur, Delhi 110054, India
| | - Mustoori Sairam
- Defence Institute of Physiology & Allied Sciences, Defence Research and Development Organization, Lucknow Road, Timarpur, Delhi 110054, India
| | - Mrinalini Singh
- Defence Institute of Physiology & Allied Sciences, Defence Research and Development Organization, Lucknow Road, Timarpur, Delhi 110054, India
| | | | - Anju Bansal
- Defence Institute of Physiology & Allied Sciences, Defence Research and Development Organization, Lucknow Road, Timarpur, Delhi 110054, India
| | - Govindaswamy Ilavazaghan
- Defence Institute of Physiology & Allied Sciences, Defence Research and Development Organization, Lucknow Road, Timarpur, Delhi 110054, India
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50
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Clerici C, Planès C. Gene regulation in the adaptive process to hypoxia in lung epithelial cells. Am J Physiol Lung Cell Mol Physiol 2008; 296:L267-74. [PMID: 19118091 DOI: 10.1152/ajplung.90528.2008] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Lung alveolar epithelial cells are normally very well oxygenated but may be exposed to hypoxia in many pathological conditions such as pulmonary edema, acute respiratory distress syndrome, chronic obstructive pulmonary diseases, or in some environmental conditions such ascent to high altitude. The ability of alveolar epithelial cells to cope with low oxygen tensions is crucial to maintain the structural and functional integrity of the alveolar epithelium. Alveolar epithelial cells appear to be remarkably tolerant to oxygen deprivation as they are able to maintain adequate cellular ATP content during prolonged hypoxic exposure when mitochondrial oxidative phosphorylation is limited. This property mostly relies on the ability of the cells to rapidly modify their gene expression program, stimulating the expression of genes involved in anaerobic energy supply and repressing expression of genes involved in some ATP-consuming cellular processes. This adaptive strategy of the cells is mostly, but not entirely, dependent on the expression of hypoxia-inducible factors (HIFs), known to be responsible for orchestrating a large number of hypoxia-sensitive genes. This review focuses on the role of HIF isoforms expressed in alveolar epithelial cells exposed to hypoxia and on the specific hypoxic gene regulation that takes place in alveolar epithelial cells either through HIF-dependent or -independent pathways.
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Affiliation(s)
- Christine Clerici
- Service de Physiologie-Explorations Fonctionnelles, Paris cedex 18, France.
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