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Zhuang Y, Liu K, He Q, Gu X, Jiang C, Wu J. Hypoxia signaling in cancer: Implications for therapeutic interventions. MedComm (Beijing) 2023; 4:e203. [PMID: 36703877 PMCID: PMC9870816 DOI: 10.1002/mco2.203] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 12/14/2022] [Accepted: 12/18/2022] [Indexed: 01/25/2023] Open
Abstract
Hypoxia is a persistent physiological feature of many different solid tumors and a key driver of malignancy, and in recent years, it has been recognized as an important target for cancer therapy. Hypoxia occurs in the majority of solid tumors due to a poor vascular oxygen supply that is not sufficient to meet the needs of rapidly proliferating cancer cells. A hypoxic tumor microenvironment (TME) can reduce the effectiveness of other tumor therapies, such as radiotherapy, chemotherapy, and immunotherapy. In this review, we discuss the critical role of hypoxia in tumor development, including tumor metabolism, tumor immunity, and tumor angiogenesis. The treatment methods for hypoxic TME are summarized, including hypoxia-targeted therapy and improving oxygenation by alleviating tumor hypoxia itself. Hyperoxia therapy can be used to improve tissue oxygen partial pressure and relieve tumor hypoxia. We focus on the underlying mechanisms of hyperoxia and their impact on current cancer therapies and discuss the prospects of hyperoxia therapy in cancer treatment.
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Affiliation(s)
- Yan Zhuang
- State Key Laboratory of Pharmaceutical BiotechnologyNational Institute of Healthcare Data Science at Nanjing UniversityJiangsu Key Laboratory of Molecular MedicineMedicineMedical School of Nanjing UniversityNanjing UniversityNanjingChina
| | - Kua Liu
- State Key Laboratory of Pharmaceutical BiotechnologyNational Institute of Healthcare Data Science at Nanjing UniversityJiangsu Key Laboratory of Molecular MedicineMedicineMedical School of Nanjing UniversityNanjing UniversityNanjingChina
| | - Qinyu He
- State Key Laboratory of Pharmaceutical BiotechnologyNational Institute of Healthcare Data Science at Nanjing UniversityJiangsu Key Laboratory of Molecular MedicineMedicineMedical School of Nanjing UniversityNanjing UniversityNanjingChina
| | - Xiaosong Gu
- Microecological, Regenerative and Microfabrication Technical Platform for Biomedicine and Tissue EngineeringJinan Microecological Biomedicine Shandong LaboratoryJinan CityChina
| | - Chunping Jiang
- State Key Laboratory of Pharmaceutical BiotechnologyNational Institute of Healthcare Data Science at Nanjing UniversityJiangsu Key Laboratory of Molecular MedicineMedicineMedical School of Nanjing UniversityNanjing UniversityNanjingChina,Microecological, Regenerative and Microfabrication Technical Platform for Biomedicine and Tissue EngineeringJinan Microecological Biomedicine Shandong LaboratoryJinan CityChina
| | - Junhua Wu
- State Key Laboratory of Pharmaceutical BiotechnologyNational Institute of Healthcare Data Science at Nanjing UniversityJiangsu Key Laboratory of Molecular MedicineMedicineMedical School of Nanjing UniversityNanjing UniversityNanjingChina,Microecological, Regenerative and Microfabrication Technical Platform for Biomedicine and Tissue EngineeringJinan Microecological Biomedicine Shandong LaboratoryJinan CityChina
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2
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Kumar S, Fathima E, Khanum F, Malini SS. Significance of the Wnt canonical pathway in radiotoxicity via oxidative stress of electron beam radiation and its molecular control in mice. Int J Radiat Biol 2022; 99:459-473. [PMID: 35758974 DOI: 10.1080/09553002.2022.2094018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
PURPOSE Radiation triggers cell death events through signaling proteins, but the combined mechanism of these events is unexplored The Wnt canonical pathway, on the other hand, is essential for cell regeneration and cell fate determination. AIM The relationship between the Wnt pathway's response to radiation and its role in radiotoxicity is overlooked, even though it is a critical molecular control of the cell. The Wnt pathway has been predicted to have radioprotective properties in some reports, but the overall mechanism is unknown. We intend to investigate how this combined cascade works throughout the radiation process and its significance over radiotoxicity. MATERIALS AND METHODS Thirty adult mice were irradiated with electron beam radiation, and 5 served as controls. Mice were sacrificed after 24 h and 30 days of irradiation. We assessed DNA damage studies, oxidative stress parameters, mRNA profiles, protein level (liver, kidney, spleen, and germ cells), sperm viability, and motility. OBSERVATION The mRNA profile helps to understand how the combined cascade of the Wnt pathway and NHEJ work together during radiation to combat oxidative response and cell survival. The quantitative examination of mRNA uncovers unique critical changes in all mRNA levels in all cases, particularly in germ cells. Recuperation was likewise seen in post-30 day's radiation in the liver, spleen, and kidney followed by oxidative stress parameters, however not in germ cells. It proposes that reproductive physiology is exceptionally sensitive to radiation, even at the molecular level. It also suggests the suppression of Lef1/Axin2 could be the main reason for the permanent failure of the sperm function process. Post-irradiation likewise influences the morphology of sperm. The decrease in mRNA levels of Lef1, Axin2, Survivin, Ku70, and XRCC6 levels suggests radiation inhibits the Wnt canonical pathway and failure in DNA repair mechanisms in a coupled manner. An increase in Bax, Bcl2, and caspase3 suggests apoptosis activation followed by the decreased expression of enzymatic antioxidants. CONCLUSION Controlled several interlinked such as the Wnt canonical pathway, NHEJ pathway, and intrinsic apoptotic pathway execute when the whole body is exposed to radiation. These pathways decide the cell fate whether it will survive or will go to apoptosis which may further be used in a study to counterpart and better comprehend medication focus on radiation treatment.
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Affiliation(s)
- Shashank Kumar
- Molecular Reproductive and Human Genetics Laboratory, Department of Zoology, University of Mysore, Mysuru, India
| | - Eram Fathima
- Defense Food Research Laboratory, Defense Research Development Organisation, Mysuru, India
| | - Farhath Khanum
- Defense Food Research Laboratory, Defense Research Development Organisation, Mysuru, India
| | - Suttur S Malini
- Molecular Reproductive and Human Genetics Laboratory, Department of Zoology, University of Mysore, Mysuru, India
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3
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Abstract
IMPACT STATEMENT Tumor hypoxia promotes cancer cell aggressiveness, and is strongly associated with poor prognosis across multiple tumor types. The hypoxic microenvironments inside tumors also limit the effectiveness of radiotherapy, chemotherapy, and immunotherapy. Several approaches to eliminate hypoxic state in tumors have been proposed to delay cancer progression and improve therapeutic efficacies. This review will summarize current knowledge on hyperoxia, used alone or in combination with other therapeutic modalities, in cancer treatment. Molecular mechanisms and undesired side effects of hyperoxia will also be discussed.
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Affiliation(s)
- Sei W Kim
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Eunpyeong St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul 03312, Republic of Korea
| | - In K Kim
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Eunpyeong St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul 03312, Republic of Korea
- Cancer Research Institute, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea
| | - Sang H Lee
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Eunpyeong St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul 03312, Republic of Korea
- Cancer Research Institute, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea
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4
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Potteti HR, Rajasekaran S, Rajamohan SB, Tamatam CR, Reddy NM, Reddy SP. Sirtuin 1 Promotes Hyperoxia-Induced Lung Epithelial Cell Death Independent of NF-E2-Related Factor 2 Activation. Am J Respir Cell Mol Biol 2017; 54:697-706. [PMID: 26465873 DOI: 10.1165/rcmb.2014-0056oc] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Lung epithelial cell damage accompanied by death is a cardinal feature of toxicant- and prooxidant-induced acute lung injury. The transcription factor nuclear factor (erythroid-derived 2)-like 2 (NEF2L2 or NRF2) activates several antioxidant enzymes (AOEs) and prosurvival genes in response to oxidant stress, and its deficiency enhances susceptibility to hyperoxic lung injury and other oxidant-induced lung pathologies. Sirtuin 1 (SIRT1) regulates cell growth and survival in response to both physiological and pathological stresses by selectively deacetylating multiple proteins required for chromatin remodeling and transcription; therefore, we sought to examine potential SIRT1-NRF2 cross-talk in the regulation of AOE expression during hyperoxia-induced lung epithelial cell death. Unexpectedly, pharmacological inhibition or small interfering RNA-mediated depletion of SIRT1 caused a reduction in cell death, accompanied by reduced levels of NRF2-dependent AOE expression in chronic hyperoxia. NRF2 acetylation was markedly and transiently higher in cells exposed to acute (6 h) hyperoxia. Sirtinol blocked this acute effect, but NRF2 acetylation was low or undetectable in cells exposed to chronic hyperoxia (24-36 h) both with and without sirtinol. SIRT1 activation by resveratrol augmented hyperoxia-induced death in cells with NRF2 deficiency. SIRT1 inhibition or depletion led to a reduced activation of the cell-death executioner caspase 3, whereas caspase inhibition prevented death. Consistent with these results, sirtinol attenuated hyperoxia-induced lung alveolar permeability and toxicity in vivo. Collectively, these results reveal that, in chronic hyperoxia, SIRT1 promotes hyperoxia-induced lung epithelial cell damage and death by altering pro- and antiapoptotic balance, not by dampening optimal NRF2-dependent AOE expression.
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Affiliation(s)
- Haranatha R Potteti
- Division of Developmental Biology and Basic Research, Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois
| | - Subbiah Rajasekaran
- Division of Developmental Biology and Basic Research, Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois
| | - Senthilkumar B Rajamohan
- Division of Developmental Biology and Basic Research, Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois
| | - Chandramohan R Tamatam
- Division of Developmental Biology and Basic Research, Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois
| | - Narsa M Reddy
- Division of Developmental Biology and Basic Research, Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois
| | - Sekhar P Reddy
- Division of Developmental Biology and Basic Research, Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois
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5
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Ten VS. Mitochondrial dysfunction in alveolar and white matter developmental failure in premature infants. Pediatr Res 2017; 81:286-292. [PMID: 27901512 PMCID: PMC5671686 DOI: 10.1038/pr.2016.216] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 08/19/2016] [Indexed: 01/11/2023]
Abstract
At birth, some organs in premature infants are not developed enough to meet challenges of the extra-uterine life. Although growth and maturation continues after premature birth, postnatal organ development may become sluggish or even arrested, leading to organ dysfunction. There is no clear mechanistic concept of this postnatal organ developmental failure in premature neonates. This review introduces a concept-forming hypothesis: Mitochondrial bioenergetic dysfunction is a fundamental mechanism of organs maturation failure in premature infants. Data collected in support of this hypothesis are relevant to two major diseases of prematurity: white matter injury and broncho-pulmonary dysplasia. In these diseases, totally different clinical manifestations are defined by the same biological process, developmental failure of the main functional units-alveoli in the lungs and axonal myelination in the brain. Although molecular pathways regulating alveolar and white matter maturation differ, proper bioenergetic support of growth and maturation remains critical biological requirement for any actively developing organ. Literature analysis suggests that successful postnatal pulmonary and white matter development highly depends on mitochondrial function which can be inhibited by sublethal postnatal stress. In premature infants, sublethal stress results mostly in organ maturation failure without excessive cellular demise.
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Affiliation(s)
- Vadim S. Ten
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, New York
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6
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Forred BJ, Daugaard DR, Titus BK, Wood RR, Floen MJ, Booze ML, Vitiello PF. Detoxification of Mitochondrial Oxidants and Apoptotic Signaling Are Facilitated by Thioredoxin-2 and Peroxiredoxin-3 during Hyperoxic Injury. PLoS One 2017; 12:e0168777. [PMID: 28045936 PMCID: PMC5207683 DOI: 10.1371/journal.pone.0168777] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 12/06/2016] [Indexed: 01/22/2023] Open
Abstract
Mitochondria play a fundamental role in the regulation of cell death during accumulation of oxidants. High concentrations of atmospheric oxygen (hyperoxia), used clinically to treat tissue hypoxia in premature newborns, is known to elicit oxidative stress and mitochondrial injury to pulmonary epithelial cells. A consequence of oxidative stress in mitochondria is the accumulation of peroxides which are detoxified by the dedicated mitochondrial thioredoxin system. This system is comprised of the oxidoreductase activities of peroxiredoxin-3 (Prx3), thioredoxin-2 (Trx2), and thioredoxin reductase-2 (TrxR2). The goal of this study was to understand the role of the mitochondrial thioredoxin system and mitochondrial injuries during hyperoxic exposure. Flow analysis of the redox-sensitive, mitochondrial-specific fluorophore, MitoSOX, indicated increased levels of mitochondrial oxidant formation in human adenocarcinoma cells cultured in 95% oxygen. Increased expression of Trx2 and TrxR2 in response to hyperoxia were not attributable to changes in mitochondrial mass, suggesting that hyperoxic upregulation of mitochondrial thioredoxins prevents accumulation of oxidized Prx3. Mitochondrial oxidoreductase activities were modulated through pharmacological inhibition of TrxR2 with auranofin and genetically through shRNA knockdown of Trx2 and Prx3. Diminished Trx2 and Prx3 expression was associated with accumulation of mitochondrial superoxide; however, only shRNA knockdown of Trx2 increased susceptibility to hyperoxic cell death and increased phosphorylation of apoptosis signal-regulating kinase-1 (ASK1). In conclusion, the mitochondrial thioredoxin system regulates hyperoxic-mediated death of pulmonary epithelial cells through detoxification of oxidants and regulation of redox-dependent apoptotic signaling.
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Affiliation(s)
- Benjamin J. Forred
- Children’s Health Research Center, Sanford Research, Sioux Falls, South Dakota, United States of America
| | - Darwin R. Daugaard
- Children’s Health Research Center, Sanford Research, Sioux Falls, South Dakota, United States of America
| | - Brianna K. Titus
- Children’s Health Research Center, Sanford Research, Sioux Falls, South Dakota, United States of America
| | - Ryan R. Wood
- Children’s Health Research Center, Sanford Research, Sioux Falls, South Dakota, United States of America
| | - Miranda J. Floen
- Children’s Health Research Center, Sanford Research, Sioux Falls, South Dakota, United States of America
| | - Michelle L. Booze
- Children’s Health Research Center, Sanford Research, Sioux Falls, South Dakota, United States of America
| | - Peter F. Vitiello
- Children’s Health Research Center, Sanford Research, Sioux Falls, South Dakota, United States of America
- Department of Pediatrics, University of South Dakota Sanford School of Medicine, Sioux Falls, South Dakota, United States of America
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7
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Morales-Nebreda LI, Rogel MR, Eisenberg JL, Hamill KJ, Soberanes S, Nigdelioglu R, Chi M, Cho T, Radigan KA, Ridge KM, Misharin AV, Woychek A, Hopkinson S, Perlman H, Mutlu GM, Pardo A, Selman M, Jones JCR, Budinger GRS. Lung-specific loss of α3 laminin worsens bleomycin-induced pulmonary fibrosis. Am J Respir Cell Mol Biol 2016; 52:503-12. [PMID: 25188360 DOI: 10.1165/rcmb.2014-0057oc] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Laminins are heterotrimeric proteins that are secreted by the alveolar epithelium into the basement membrane, and their expression is altered in extracellular matrices from patients with pulmonary fibrosis. In a small number of patients with pulmonary fibrosis, we found that the normal basement membrane distribution of the α3 laminin subunit was lost in fibrotic regions of the lung. To determine if these changes play a causal role in the development of fibrosis, we generated mice lacking the α3 laminin subunit specifically in the lung epithelium by crossing mice expressing Cre recombinase driven by the surfactant protein C promoter (SPC-Cre) with mice expressing floxed alleles encoding the α3 laminin gene (Lama3(fl/fl)). These mice exhibited no developmental abnormalities in the lungs up to 6 months of age, but, compared with control mice, had worsened mortality, increased inflammation, and increased fibrosis after the intratracheal administration of bleomycin. Similarly, the severity of fibrosis induced by an adenovirus encoding an active form of transforming growth factor-β was worse in mice deficient in α3 laminin in the lung. Taken together, our results suggest that the loss of α3 laminin in the lung epithelium does not affect lung development, but plays a causal role in the development of fibrosis in response to bleomycin or adenovirally delivered transforming growth factor-β. Thus, we speculate that the loss of the normal basement membrane organization of α3 laminin that we observe in fibrotic regions from the lungs of patients with pulmonary fibrosis contributes to their disease progression.
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Affiliation(s)
- Luisa I Morales-Nebreda
- 1 Division of Pulmonary and Critical Care Medicine and the Department of Cell and Molecular Biology, Feinberg School of Medicine at Northwestern University, Chicago, Illinois
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8
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Patel A, Zhang S, Moorthy B, Shivanna B. Omeprazole does not Potentiate Acute Oxygen Toxicity in Fetal Human Pulmonary Microvascular Endothelial Cells Exposed to Hyperoxia. ACTA ACUST UNITED AC 2015; 6. [PMID: 26779382 PMCID: PMC4712726 DOI: 10.4172/2153-2435.1000424] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Hyperoxia contributes to the pathogenesis of broncho-pulmonary dysplasia (BPD), which is a developmental lung disease of premature infants that is characterized by an interruption of lung alveolar and pulmonary vascular development. Omeprazole (OM) is a proton pump inhibitor that is used to treat humans with gastric acid related disorders. Earlier we observed that OM-mediated aryl hydrocarbon receptor (AhR) activation attenuates acute hyperoxic lung injury in adult mice and oxygen toxicity in adult human lung cells. However, our later studies in newborn mice demonstrated that OM potentiates hyperoxia-induced developmental lung injury. Whether OM exerts a similar toxicity in primary human fetal lung cells is unknown. Hence, we tested the hypothesis that OM potentiates hyperoxia-induced cytotoxicity and ROS generation in the human fetal lung derived primary human pulmonary microvascular endothelial cells (HPMEC). OM activated AhR as evident by a dose-dependent increase in cytochrome P450 (CYP) 1A1 mRNA levels in OM-treated cells. Furthermore, OM at a concentration of 100 μM (OM 100) increased NADP(H) quinone oxidoreductase 1 (NQO1) expression. Surprisingly, hyperoxia decreased rather than increase the NQO1 protein levels in OM 100-treated cells. Exposure to hyperoxia increased cytotoxicity and hydrogen peroxide (H2O2) levels. Interestingly, OM 100-treated cells exposed to air had increased H2O2 levels. However, hyperoxia did not further augment H2O2 levels in OM 100-treated cells. Additionally, hyperoxia-mediated oxygen toxicity was similar in both vehicle- and OM-treated cells. These findings contradict our hypothesis and support the hypothesis that OM does not potentiate acute hyperoxic injury in HPMEC in vitro.
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Affiliation(s)
- Ananddeep Patel
- Section of Neonatology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Shaojie Zhang
- Section of Neonatology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Bhagavatula Moorthy
- Section of Neonatology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Binoy Shivanna
- Section of Neonatology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
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9
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Resseguie EA, Staversky RJ, Brookes PS, O'Reilly MA. Hyperoxia activates ATM independent from mitochondrial ROS and dysfunction. Redox Biol 2015; 5:176-185. [PMID: 25967673 PMCID: PMC4430709 DOI: 10.1016/j.redox.2015.04.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 04/25/2015] [Indexed: 01/12/2023] Open
Abstract
High levels of oxygen (hyperoxia) are often used to treat individuals with respiratory distress, yet prolonged hyperoxia causes mitochondrial dysfunction and excessive reactive oxygen species (ROS) that can damage molecules such as DNA. Ataxia telangiectasia mutated (ATM) kinase is activated by nuclear DNA double strand breaks and delays hyperoxia-induced cell death through downstream targets p53 and p21. Evidence for its role in regulating mitochondrial function is emerging, yet it has not been determined if mitochondrial dysfunction or ROS activates ATM. Because ATM maintains mitochondrial homeostasis, we hypothesized that hyperoxia induces both mitochondrial dysfunction and ROS that activate ATM. In A549 lung epithelial cells, hyperoxia decreased mitochondrial respiratory reserve capacity at 12h and basal respiration by 48 h. ROS were significantly increased at 24h, yet mitochondrial DNA double strand breaks were not detected. ATM was not required for activating p53 when mitochondrial respiration was inhibited by chronic exposure to antimycin A. Also, ATM was not further activated by mitochondrial ROS, which were enhanced by depleting manganese superoxide dismutase (SOD2). In contrast, ATM dampened the accumulation of mitochondrial ROS during exposure to hyperoxia. Our findings suggest that hyperoxia-induced mitochondrial dysfunction and ROS do not activate ATM. ATM more likely carries out its canonical response to nuclear DNA damage and may function to attenuate mitochondrial ROS that contribute to oxygen toxicity.
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Affiliation(s)
- Emily A Resseguie
- Department of Environmental Medicine, University of Rochester, Rochester, NY 14642, USA
| | - Rhonda J Staversky
- Department of Pediatrics, University of Rochester, Rochester, NY 14642, USA
| | - Paul S Brookes
- Department of Anesthesiology, University of Rochester, Rochester, NY 14642, USA
| | - Michael A O'Reilly
- Department of Environmental Medicine, University of Rochester, Rochester, NY 14642, USA; Department of Pediatrics, University of Rochester, Rochester, NY 14642, USA.
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10
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Zhang S, Patel A, Moorthy B, Shivanna B. Adrenomedullin deficiency potentiates hyperoxic injury in fetal human pulmonary microvascular endothelial cells. Biochem Biophys Res Commun 2015. [PMID: 26196743 DOI: 10.1016/j.bbrc.2015.07.067] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Bronchopulmonary dysplasia (BPD) is a chronic lung disease of premature infants that is characterized by alveolar simplification and decreased lung angiogenesis. Hyperoxia-induced oxidative stress and inflammation contributes to the development of BPD in premature infants. Adrenomedullin (AM) is an endogenous peptide with potent angiogenic, anti-oxidant, and anti-inflammatory properties. Whether AM regulates hyperoxic injury in fetal primary human lung cells is unknown. Therefore, we tested the hypothesis that AM-deficient fetal primary human pulmonary microvascular endothelial cells (HPMEC) will have increased oxidative stress, inflammation, and cytotoxicity compared to AM-sufficient HPMEC upon exposure to hyperoxia. Adrenomedullin gene (Adm) was knocked down in HPMEC by siRNA-mediated transfection and the resultant AM-sufficient and -deficient cells were evaluated for hyperoxia-induced oxidative stress, inflammation, cytotoxicity, and Akt activation. AM-deficient HPMEC had significantly increased hyperoxia-induced reactive oxygen species (ROS) generation and cytotoxicity compared to AM-sufficient HPMEC. Additionally, AM-deficient cell culture supernatants had increased macrophage inflammatory protein 1α and 1β, indicating a heightened inflammatory state. Interestingly, AM deficiency was associated with an abrogated Akt activation upon exposure to hyperoxia. These findings support the hypothesis that AM deficiency potentiates hyperoxic injury in primary human fetal HPMEC via mechanisms entailing Akt activation.
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Affiliation(s)
- Shaojie Zhang
- Section of Neonatology, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Ananddeep Patel
- Section of Neonatology, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Bhagavatula Moorthy
- Section of Neonatology, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Binoy Shivanna
- Section of Neonatology, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.
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11
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Abstract
Oxygen is the basic molecule which supports life and it truly is "god's gift to life." Despite its immense importance, research on "oxygen biology" has never received the light of the day and has been limited to physiological and biochemical studies. It seems that in modern day biology, oxygen research is summarized in one word "hypoxia." Scientists have focused on hypoxia-induced transcriptomics and molecular-cellular alterations exclusively in disease models. Interestingly, the potential of oxygen to control the basic principles of biology like homeostatic maintenance, transcription, replication, and protein folding among many others, at the molecular level, has been completely ignored. Here, we present a perspective on the crucial role played by oxygen in regulation of basic biological phenomena. Our conclusion highlights the importance of establishing novel research areas like oxygen biology, as there is great potential in this field for basic science discoveries and clinical benefits to the society.
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12
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Zhang S, Patel A, Chu C, Jiang W, Wang L, Welty SE, Moorthy B, Shivanna B. Aryl hydrocarbon receptor is necessary to protect fetal human pulmonary microvascular endothelial cells against hyperoxic injury: Mechanistic roles of antioxidant enzymes and RelB. Toxicol Appl Pharmacol 2015; 286:92-101. [PMID: 25831079 DOI: 10.1016/j.taap.2015.03.023] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 03/10/2015] [Accepted: 03/19/2015] [Indexed: 02/03/2023]
Abstract
Hyperoxia contributes to the development of bronchopulmonary dysplasia (BPD) in premature infants. Activation of the aryl hydrocarbon receptor (AhR) protects adult and newborn mice against hyperoxic lung injury by mediating increases in the expression of phase I (cytochrome P450 (CYP) 1A) and phase II (NADP(H) quinone oxidoreductase (NQO1)) antioxidant enzymes (AOE). AhR positively regulates the expression of RelB, a component of the nuclear factor-kappaB (NF-κB) protein that contributes to anti-inflammatory processes in adult animals. Whether AhR regulates the expression of AOE and RelB, and protects fetal primary human lung cells against hyperoxic injury is unknown. Therefore, we tested the hypothesis that AhR-deficient fetal human pulmonary microvascular endothelial cells (HPMEC) will have decreased RelB activation and AOE, which will in turn predispose them to increased oxidative stress, inflammation, and cell death compared to AhR-sufficient HPMEC upon exposure to hyperoxia. AhR-deficient HPMEC showed increased hyperoxia-induced reactive oxygen species (ROS) generation, cleavage of poly(ADP-ribose) polymerase (PARP), and cell death compared to AhR-sufficient HPMEC. Additionally, AhR-deficient cell culture supernatants displayed increased macrophage inflammatory protein 1α and 1β, indicating a heightened inflammatory state. Interestingly, loss of AhR was associated with a significantly attenuated CYP1A1, NQO1, superoxide dismutase 1(SOD1), and nuclear RelB protein expression. These findings support the hypothesis that decreased RelB activation and AOE in AhR-deficient cells is associated with increased hyperoxic injury compared to AhR-sufficient cells.
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Affiliation(s)
- Shaojie Zhang
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ananddeep Patel
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Chun Chu
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Weiwu Jiang
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lihua Wang
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Stephen E Welty
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Bhagavatula Moorthy
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Binoy Shivanna
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA.
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13
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Ding Z, Zhang Z, Ma H, Chen Y. In vitro hemocompatibility and toxic mechanism of graphene oxide on human peripheral blood T lymphocytes and serum albumin. ACS APPLIED MATERIALS & INTERFACES 2014; 6:19797-19807. [PMID: 25371999 DOI: 10.1021/am505084s] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Graphene oxide (GO) has shown tremendous application potential as a biomedical material. However, its interactions with blood components are not yet well understood. In this work, we assess the toxicity of pristine GO (p-GO) and functionalized GO (GO-COOH and GO-PEI) to primary human peripheral blood T lymphocytes and human serum albumin (HSA), and also study the underlying toxic mechanism. Our results indicate that p-GO and GO-COOH have good biocompatibility to T lymphocytes at the concentration below 25 μg mL(-1), but notable cytotoxicity above 50 μg mL(-1). By contrast, GO-PEI exhibits significant toxicity even at 1.6 μg mL(-1). Further investigations show that although p-GO does not enter into the cell or damage the membrane, its presence leads to the increase in reactive oxygen species (ROS), moderate DNA damage, and T lymphocyte apoptosis. Interestingly, little effect on T lymphocyte immune response suppression is observed in this process despite p-GO inflicting cell apoptosis. The toxic mechanism is that p-GO interacts directly with the protein receptors to inhibit their ligand-binding ability, leading to ROS-dependent passive apoptosis through the B-cell lymphoma-2 (Bcl-2) pathway. Compared with p-GO, GO-COOH exhibits a similar toxic effect on T lymphocytes except keeping a normal ROS level. A proposed toxic mechanism is that GO-COOH inhibits protein receptor-ligand binding, and passes the passive apoptosis signal to nucleus DNA through a ROS-independent mechanism. On the other hand, GO-PEI shows severe hematotoxicity to T lymphocytes by inducing membrane damage. For plasma protein HSA, the binding of GO-COOH results in minimal conformational change and HSA's binding capacity to bilirubin remains unaffected, while the binding of p-GO and GO-PEI exhibits strong toxicity on HSA. These findings on the interactions of two-dimensional nanomaterials and biological systems, along with the enquiry of the mechanisms, would provide essential support for further safety evaluation of the biomedical applications of GO.
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Affiliation(s)
- Zhijia Ding
- Key Laboratory for Nano-Bio Interface Research, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences , Suzhou 215123, China
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Biphasic response of checkpoint control proteins in hyperoxia: exposure to lower levels of oxygen induces genome maintenance genes in experimental baboon BPD. Mol Cell Biochem 2014; 395:187-98. [PMID: 24939362 DOI: 10.1007/s11010-014-2124-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 06/02/2014] [Indexed: 12/23/2022]
Abstract
Breathing high concentrations of oxygen (hyperoxia) causes lung injury and is associated with lung diseases such as bronchopulmonary dysplasia (BPD), respiratory distress syndrome and persistent pulmonary hypertension of the newborns. Hyperoxia (95-100 %O2) causes DNA damage and growth arrest of lung cells and consequently cells die by apoptosis or necrosis. Although supplemental oxygen therapy is clinically important, the level and duration of hyperoxic exposure that would allow lung cells to reenter the cell cycle remains unclear. We hypothesized that cells exposed to lower concentrations of hyperoxia will retain the capacity to enter cell cycle when recovered in room air. We employed varying concentrations of oxygen (21-95 %) to determine the response of lung cells to hyperoxia. Our results indicate that cells were growth arrested and failed to reenter the cell cycle when exposed to greater than 60 % oxygen. Cell cycle checkpoint proteins were increased in a biphasic manner, increasing until 70 % oxygen, but declined in greater than 90 % oxygen. Microarray analysis shows that there is significant decrease in the abundance of Cdks 6-8 and retinoblastoma protein (Rb), p107 and p130 in exposure to 90 % oxygen for 48 h. We further tested the effect of clinically relevant as needed oxygen [(pro-re-nata (prn)] in premature infant (125-days and 140-days) baboon model of BPD. The microarray results show that 6 or 14d PRN oxygen-exposed animals had induced expression of chromosomal maintenance genes (MCMs), genes related to anti-inflammation, proliferation, and differentiation.
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Influence of oxygen tension on dopaminergic differentiation of human fetal stem cells of midbrain and forebrain origin. PLoS One 2014; 9:e96465. [PMID: 24788190 PMCID: PMC4008610 DOI: 10.1371/journal.pone.0096465] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 04/08/2014] [Indexed: 01/09/2023] Open
Abstract
Neural stem cells (NSCs) constitute a promising source of cells for transplantation in Parkinson's disease (PD), but protocols for controlled dopaminergic differentiation are not yet available. Here we investigated the influence of oxygen on dopaminergic differentiation of human fetal NSCs derived from the midbrain and forebrain. Cells were differentiated for 10 days in vitro at low, physiological (3%) versus high, atmospheric (20%) oxygen tension. Low oxygen resulted in upregulation of vascular endothelial growth factor and increased the proportion of tyrosine hydroxylase-immunoreactive (TH-ir) cells in both types of cultures (midbrain: 9.1±0.5 and 17.1±0.4 (P<0.001); forebrain: 1.9±0.4 and 3.9±0.6 (P<0.01) percent of total cells). Regardless of oxygen levels, the content of TH-ir cells with mature neuronal morphologies was higher for midbrain as compared to forebrain cultures. Proliferative Ki67-ir cells were found in both types of cultures, but the relative proportion of these cells was significantly higher for forebrain NSCs cultured at low, as compared to high, oxygen tension. No such difference was detected for midbrain-derived cells. Western blot analysis revealed that low oxygen enhanced β-tubulin III and GFAP expression in both cultures. Up-regulation of β-tubulin III was most pronounced for midbrain cells, whereas GFAP expression was higher in forebrain as compared to midbrain cells. NSCs from both brain regions displayed less cell death when cultured at low oxygen tension. Following mictrotransplantation into mouse striatal slice cultures predifferentiated midbrain NSCs were found to proliferate and differentiate into substantial numbers of TH-ir neurons with mature neuronal morphologies, particularly at low oxygen. In contrast, predifferentiated forebrain NSCs microtransplanted using identical conditions displayed little proliferation and contained few TH-ir cells, all of which had an immature appearance. Our data may reflect differences in dopaminergic differentiation capacity and region-specific requirements of NSCs, with the dopamine-depleted striatum cultured at low oxygen offering an attractive micro-environment for midbrain NSCs.
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Eftedal I, Ljubkovic M, Flatberg A, Jørgensen A, Brubakk AO, Dujic Z. Acute and potentially persistent effects of scuba diving on the blood transcriptome of experienced divers. Physiol Genomics 2013; 45:965-72. [PMID: 23964024 DOI: 10.1152/physiolgenomics.00164.2012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
During scuba diving, the circulatory system is stressed by an elevated partial pressure of oxygen while the diver is submerged and by decompression-induced gas bubbles on ascent to the surface. This diving-induced stress may trigger decompression illness, but the majority of dives are asymptomatic. In this study we have mapped divers' blood transcriptomes with the aim of identifying genes, biological pathways, and cell types perturbed by the physiological stress in asymptomatic scuba diving. Ten experienced divers abstained from diving for >2 wk before performing a 3-day series of daily dives to 18 m depth for 47 min while breathing compressed air. Blood for microarray analysis was collected before and immediately after the first and last dives, and 10 matched nondivers provided controls for predive stationary transcriptomes. MetaCore GeneGo analysis of the predive samples identified stationary upregulation of genes associated with apoptosis, inflammation, and innate immune responses in the divers, most significantly involving genes in the TNFR1 pathway of caspase-dependent apoptosis, HSP60/HSP70 signaling via TLR4, and NF-κB-mediated transcription. Diving caused pronounced shifts in transcription patterns characteristic of specific leukocytes, with downregulation of genes expressed by CD8+ T lymphocytes and NK cells and upregulation of genes expressed by neutrophils, monocytes, and macrophages. Antioxidant genes were upregulated. Similar transient responses were observed after the first and last dive. The results indicate that sublethal oxidative stress elicits the myeloid innate immune system in scuba diving and that extensive diving may cause persistent change in pathways controlling apoptosis, inflammation, and innate immune responses.
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Affiliation(s)
- Ingrid Eftedal
- Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
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17
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Ballinger MN, Newstead MW, Zeng X, Bhan U, Horowitz JC, Moore BB, Pinsky DJ, Flavell RA, Standiford TJ. TLR signaling prevents hyperoxia-induced lung injury by protecting the alveolar epithelium from oxidant-mediated death. THE JOURNAL OF IMMUNOLOGY 2012; 189:356-64. [PMID: 22661086 DOI: 10.4049/jimmunol.1103124] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Mechanical ventilation using high oxygen tensions is often necessary to treat patients with respiratory failure. Recently, TLRs were identified as regulators of noninfectious oxidative lung injury. IRAK-M is an inhibitor of MyD88-dependent TLR signaling. Exposure of mice deficient in IRAK-M (IRAK-M(-/-)) to 95% oxygen resulted in reduced mortality compared with wild-type mice and occurred in association with decreased alveolar permeability and cell death. Using a bone marrow chimera model, we determined that IRAK-M's effects were mediated by structural cells rather than bone marrow-derived cells. We confirmed the expression of IRAK-M in alveolar epithelial cells (AECs) and showed that hyperoxia can induce the expression of this protein. In addition, IRAK-M(-/-) AECs exposed to hyperoxia experienced a decrease in cell death. IRAK-M may potentiate hyperoxic injury by suppression of key antioxidant pathways, because lungs and AECs isolated from IRAK-M(-/-) mice have increased expression/activity of heme oxygenase-1, a phase II antioxidant, and NF (erythroid-derived)-related factor-2, a transcription factor that initiates antioxidant generation. Treatment of IRAK-M(-/-) mice in vivo and IRAK-M(-/-) AECs in vitro with the heme oxygenase-1 inhibitor, tin protoporphyrin, substantially decreased survival and significantly reduced the number of live cells after hyperoxia exposure. Collectively, our data suggest that IRAK-M inhibits the induction of antioxidants essential for protecting the lungs against cell death, resulting in enhanced susceptibility to hyperoxic lung injury.
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Affiliation(s)
- Megan N Ballinger
- Division of Pulmonary and Critical Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
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Kim MN, Lee KE, Hong JY, Heo WI, Kim KW, Kim KE, Sohn MH. Involvement of the MAPK and PI3K pathways in chitinase 3-like 1-regulated hyperoxia-induced airway epithelial cell death. Biochem Biophys Res Commun 2012; 421:790-6. [PMID: 22554524 DOI: 10.1016/j.bbrc.2012.04.085] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 04/14/2012] [Indexed: 11/17/2022]
Abstract
BACKGROUND Exposure to 100% oxygen causes hyperoxic acute lung injury characterized by cell death and injury of alveolar epithelial cells. Recently, the role of chitinase 3-like 1 (CHI3L1), a member of the glycosyl hydrolase 18 family that lacks chitinase activity, in oxidative stress was demonstrated in murine models. High levels of serum CHI3L1 have been associated with various diseases of the lung, such as asthma, chronic obstructive pulmonary disease, and cancer. However, the role of CHI3L1 in human airway epithelial cells undergoing oxidative stress remains unknown. In addition, the signaling pathways associated with CHI3L1 in this process are poorly understood. PURPOSE In this study, we demonstrate the role of CHI3L1, along with the MAPK and PI3K signaling pathways, in hyperoxia-exposed airway epithelial cells. METHOD The human airway epithelial cell line, BEAS-2B, was exposed to >95% oxygen (hyperoxia) for up to 72h. Hyperoxia-induced cell death was determined by assessing cell viability, Annexin-V FITC staining, caspase-3 and -7 expression, and electron microscopy. CHI3L1 knockdown and overexpression studies were conducted in BEAS-2B cells to examine the role of CHI3L1 in hyperoxia-induced apoptosis. Activation of the MAPK and PI3K pathways was also investigated to determine the role of these signaling cascades in this process. RESULTS Hyperoxia exposure increased CHI3L1 expression and apoptosis in a time-dependent manner. CHI3L1 knockdown protected cells from hyperoxia-induced apoptosis. In contrast, CHI3L1 overexpression promoted cell death after hyperoxia exposure. Finally, phosphorylation of ERK1/2, p38, and Akt were affected by CHI3L1 knockdown. CONCLUSION This study indicates that CHI3L1 is involved in hyperoxia-induced cell death, suggesting that CHI3L1 may be one of several cell death regulators influencing the MAPK and PI3K pathways during oxidative stress in human airway epithelial cells.
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Affiliation(s)
- Mi Na Kim
- Department of Pediatrics and Institute of Allergy, Severance Medical Research Institute, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Republic of Korea
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Bhandari V, Choo-Wing R, Harijith A, Sun H, Syed MA, Homer RJ, Elias JA. Increased hyperoxia-induced lung injury in nitric oxide synthase 2 null mice is mediated via angiopoietin 2. Am J Respir Cell Mol Biol 2012; 46:668-76. [PMID: 22227562 DOI: 10.1165/rcmb.2011-0074oc] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Supplemental oxygen is frequently prescribed. However, prolonged exposure to high concentrations of oxygen causes hyperoxic acute lung injury (HALI), which manifests as acute respiratory distress syndrome in adults and leads to bronchopulmonary dysplasia in newborns (NBs). Nitric oxide (NO), NO synthases (NOSs), and angiopoietin (Ang) 2 have been implicated in the pathogenesis of HALI. However, the mechanisms of the contributions of NOS/NO and the relationship(s) between NOS/NO and Ang2 have not been addressed. In addition, the relevance of these moieties in adults and NBs has not been evaluated. To address these issues, we compared the responses in hyperoxia of wild-type (NOS [+/+]) and NOS null (-/-) young adult and NB mice. When compared with NOS2(+/+) adult controls, NOS2(-/-) animals manifest exaggerated alveolar-capillary protein leak and premature death. These responses were associated with enhanced levels of structural cell death, enhanced expression of proapoptotic regulatory proteins, and Ang2. Importantly, silencing RNA knockdown of Ang2 decreased the levels of cell death and the expression of proapoptotic mediators. These effects were at least partially NOS2 specific, and were development dependent, because survival was similar in adult NOS3(+/+) and NOS3(-/-) mice and NB NOS2(+/+) and NOS2(-/-) mice, respectively. These studies demonstrate that NOS2 plays an important protective role in HALI in adult animals. They also demonstrate that this response is mediated, at least in part, by the ability of NOS2 to inhibit hyperoxia-induced Ang2 production and thereby decrease Ang2-induced tissue injury.
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Affiliation(s)
- Vineet Bhandari
- Division of Perinatal Medicine, Yale University School of Medicine, Department of Pediatrics, Children's Hospital, 20 York Street, New Haven, CT 06520-8057, USA.
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Sturrock A, Seedahmed E, Mir-Kasimov M, Boltax J, McManus ML, Paine R. GM-CSF provides autocrine protection for murine alveolar epithelial cells from oxidant-induced mitochondrial injury. Am J Physiol Lung Cell Mol Physiol 2011; 302:L343-51. [PMID: 22140071 DOI: 10.1152/ajplung.00276.2011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Exposure of mice to hyperoxia induces alveolar epithelial cell (AEC) injury, acute lung injury and death. Overexpression of granulocyte-macrophage colony-stimulating factor (GM-CSF) in the lung protects against these effects, although the mechanisms are not yet clear. Hyperoxia induces cellular injury via effects on mitochondrial integrity, associated with induction of proapoptotic members of the Bcl-2 family. We hypothesized that GM-CSF protects AEC through effects on mitochondrial integrity. MLE-12 cells (a murine type II cell line) and primary murine type II AEC were subjected to oxidative stress by exposure to 80% oxygen and by exposure to H(2)O(2). Exposure to H(2)O(2) induced cytochrome c release and decreased mitochondrial reductase activity in MLE-12 cells. Incubation with GM-CSF significantly attenuated these effects. Protection induced by GM-CSF was associated with Akt activation. GM-CSF treatment also resulted in increased expression of the antiapoptotic Bcl-2 family member, Mcl-1. Primary murine AEC were significantly more tolerant of oxidative stress than MLE-12 cells. In contrast to MLE-12 cells, primary AEC expressed significant GM-CSF at baseline and demonstrated constitutive activation of Akt and increased baseline expression of Mcl-1. Treatment with exogenous GM-CSF further increased Akt activation and Mcl-1 expression in primary AEC. Conversely, suppression of AEC GM-CSF expression by use of GM-CSF-specific small interfering RNA resulted in decreased tolerance of oxidative stress, Furthermore, silencing of Mcl-1 prevented GM-CSF-induced protection. We conclude that GM-CSF protects alveolar epithelial cells against oxidative stress-induced mitochondrial injury via the Akt pathway and its downstream components, including Mcl-1. Epithelial cell-derived GM-CSF may contribute to intrinsic defense mechanisms limiting lung injury.
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Affiliation(s)
- Anne Sturrock
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, Univ. of Utah School of Medicine, Salt Lake City, UT 84132, USA
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21
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Shivanna B, Chu C, Welty SE, Jiang W, Wang L, Couroucli XI, Moorthy B. Omeprazole attenuates hyperoxic injury in H441 cells via the aryl hydrocarbon receptor. Free Radic Biol Med 2011; 51:1910-7. [PMID: 21906671 PMCID: PMC3901644 DOI: 10.1016/j.freeradbiomed.2011.08.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Revised: 08/16/2011] [Accepted: 08/17/2011] [Indexed: 10/17/2022]
Abstract
Hyperoxia contributes to the development of bronchopulmonary dysplasia in premature infants. Earlier we observed that aryl hydrocarbon receptor (AhR)-deficient mice are more susceptible to hyperoxic lung injury than AhR-sufficient mice, and this phenomenon was associated with a lack of expression of cytochrome P450 1A enzymes. Omeprazole, a proton pump inhibitor used in humans with gastric acid-related disorders, activates AhR in hepatocytes in vitro. However, the effects of omeprazole on AhR activation in the lungs and its impact on hyperoxia-induced reactive oxygen species (ROS) generation and inflammation are unknown. In this study, we tested the hypothesis that omeprazole attenuates hyperoxia-induced cytotoxicity, ROS generation, and expression of monocyte chemoattractant protein-1 (MCP-1) in human lung-derived H441 cells via AhR activation. Experimental groups included cells transfected with AhR small interfering RNA (siRNA). Hyperoxia resulted in significant increases in cytotoxicity, ROS generation, and MCP-1 production, which were significantly attenuated with the functional activation of AhR by omeprazole. The protective effects of omeprazole on cytotoxicity, ROS production, and MCP-1 production were lost in H441 cells whose AhR gene was silenced by AhR siRNA. These findings support the hypothesis that omeprazole protects against hyperoxic injury in vitro via AhR activation that is associated with decreased ROS generation and expression of MCP-1.
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Affiliation(s)
- Binoy Shivanna
- Division of Neonatal–Perinatal Medicine, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA.
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Mutlu EA, Engen PA, Soberanes S, Urich D, Forsyth CB, Nigdelioglu R, Chiarella SE, Radigan KA, Gonzalez A, Jakate S, Keshavarzian A, Budinger GRS, Mutlu GM. Particulate matter air pollution causes oxidant-mediated increase in gut permeability in mice. Part Fibre Toxicol 2011; 8:19. [PMID: 21658250 PMCID: PMC3132719 DOI: 10.1186/1743-8977-8-19] [Citation(s) in RCA: 146] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 06/09/2011] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Exposure to particulate matter (PM) air pollution may be an important environmental factor leading to exacerbations of inflammatory illnesses in the GI tract. PM can gain access to the gastrointestinal (GI) tract via swallowing of air or secretions from the upper airways or mucociliary clearance of inhaled particles. METHODS We measured PM-induced cell death and mitochondrial ROS generation in Caco-2 cells stably expressing oxidant sensitive GFP localized to mitochondria in the absence or presence of an antioxidant. C57BL/6 mice were exposed to a very high dose of urban PM from Washington, DC (200 μg/mouse) or saline via gastric gavage and small bowel and colonic tissue were harvested for histologic evaluation, and RNA isolation up to 48 hours. Permeability to 4 kD dextran was measured at 48 hours. RESULTS PM induced mitochondrial ROS generation and cell death in Caco-2 cells. PM also caused oxidant-dependent NF-κB activation, disruption of tight junctions and increased permeability of Caco-2 monolayers. Mice exposed to PM had increased intestinal permeability compared with PBS treated mice. In the small bowel, colocalization of the tight junction protein, ZO-1 was lower in the PM treated animals. In the small bowel and colon, PM exposed mice had higher levels of IL-6 mRNA and reduced levels of ZO-1 mRNA. Increased apoptosis was observed in the colon of PM exposed mice. CONCLUSIONS Exposure to high doses of urban PM causes oxidant dependent GI epithelial cell death, disruption of tight junction proteins, inflammation and increased permeability in the gut in vitro and in vivo. These PM-induced changes may contribute to exacerbations of inflammatory disorders of the gut.
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Affiliation(s)
- Ece A Mutlu
- Department of Medicine, Section of Gastroenterology and Nutrition Rush University Medical College, 1725 W Harrison Street, Chicago, IL, 60612 USA
| | - Phillip A Engen
- Department of Medicine, Section of Gastroenterology and Nutrition Rush University Medical College, 1725 W Harrison Street, Chicago, IL, 60612 USA
| | - Saul Soberanes
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, 240 E Huron Street, McGaw M300, Chicago, IL, 60611, USA
| | - Daniela Urich
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, 240 E Huron Street, McGaw M300, Chicago, IL, 60611, USA
| | - Christopher B Forsyth
- Department of Medicine, Section of Gastroenterology and Nutrition Rush University Medical College, 1725 W Harrison Street, Chicago, IL, 60612 USA
| | - Recep Nigdelioglu
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, 240 E Huron Street, McGaw M300, Chicago, IL, 60611, USA
| | - Sergio E Chiarella
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, 240 E Huron Street, McGaw M300, Chicago, IL, 60611, USA
| | - Kathryn A Radigan
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, 240 E Huron Street, McGaw M300, Chicago, IL, 60611, USA
| | - Angel Gonzalez
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, 240 E Huron Street, McGaw M300, Chicago, IL, 60611, USA
| | - Shriram Jakate
- Department of Pathology, Rush University Medical College, 1725 W Harrison Street, Chicago, IL, 60612 USA
| | - Ali Keshavarzian
- Department of Medicine, Section of Gastroenterology and Nutrition Rush University Medical College, 1725 W Harrison Street, Chicago, IL, 60612 USA
| | - GR Scott Budinger
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, 240 E Huron Street, McGaw M300, Chicago, IL, 60611, USA
| | - Gökhan M Mutlu
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, 240 E Huron Street, McGaw M300, Chicago, IL, 60611, USA
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Budinger GRS, Mutlu GM, Urich D, Soberanes S, Buccellato LJ, Hawkins K, Chiarella SE, Radigan KA, Eisenbart J, Agrawal H, Berkelhamer S, Hekimi S, Zhang J, Perlman H, Schumacker PT, Jain M, Chandel NS. Epithelial cell death is an important contributor to oxidant-mediated acute lung injury. Am J Respir Crit Care Med 2011; 183:1043-54. [PMID: 20959557 PMCID: PMC3086743 DOI: 10.1164/rccm.201002-0181oc] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Accepted: 10/15/2010] [Indexed: 01/11/2023] Open
Abstract
RATIONALE Acute lung injury and the acute respiratory distress syndrome are characterized by increased lung oxidant stress and apoptotic cell death. The contribution of epithelial cell apoptosis to the development of lung injury is unknown. OBJECTIVES To determine whether oxidant-mediated activation of the intrinsic or extrinsic apoptotic pathway contributes to the development of acute lung injury. METHODS Exposure of tissue-specific or global knockout mice or cells lacking critical components of the apoptotic pathway to hyperoxia, a well-established mouse model of oxidant-induced lung injury, for measurement of cell death, lung injury, and survival. MEASUREMENTS AND MAIN RESULTS We found that the overexpression of SOD2 prevents hyperoxia-induced BAX activation and cell death in primary alveolar epithelial cells and prolongs the survival of mice exposed to hyperoxia. The conditional loss of BAX and BAK in the lung epithelium prevented hyperoxia-induced cell death in alveolar epithelial cells, ameliorated hyperoxia-induced lung injury, and prolonged survival in mice. By contrast, Cyclophilin D-deficient mice were not protected from hyperoxia, indicating that opening of the mitochondrial permeability transition pore is dispensable for hyperoxia-induced lung injury. Mice globally deficient in the BH3-only proteins BIM, BID, PUMA, or NOXA, which are proximal upstream regulators of BAX and BAK, were not protected against hyperoxia-induced lung injury suggesting redundancy of these proteins in the activation of BAX or BAK. CONCLUSIONS Mitochondrial oxidant generation initiates BAX- or BAK-dependent alveolar epithelial cell death, which contributes to hyperoxia-induced lung injury.
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Affiliation(s)
- G. R. Scott Budinger
- Department of Medicine, Department of Cell and Molecular Biology, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Biology, McGill University, Montreal, Quebec, Canada; and Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Gökhan M. Mutlu
- Department of Medicine, Department of Cell and Molecular Biology, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Biology, McGill University, Montreal, Quebec, Canada; and Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Daniela Urich
- Department of Medicine, Department of Cell and Molecular Biology, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Biology, McGill University, Montreal, Quebec, Canada; and Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Saul Soberanes
- Department of Medicine, Department of Cell and Molecular Biology, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Biology, McGill University, Montreal, Quebec, Canada; and Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Leonard J. Buccellato
- Department of Medicine, Department of Cell and Molecular Biology, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Biology, McGill University, Montreal, Quebec, Canada; and Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Keenan Hawkins
- Department of Medicine, Department of Cell and Molecular Biology, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Biology, McGill University, Montreal, Quebec, Canada; and Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Sergio E. Chiarella
- Department of Medicine, Department of Cell and Molecular Biology, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Biology, McGill University, Montreal, Quebec, Canada; and Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Kathryn A. Radigan
- Department of Medicine, Department of Cell and Molecular Biology, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Biology, McGill University, Montreal, Quebec, Canada; and Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - James Eisenbart
- Department of Medicine, Department of Cell and Molecular Biology, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Biology, McGill University, Montreal, Quebec, Canada; and Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Hemant Agrawal
- Department of Medicine, Department of Cell and Molecular Biology, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Biology, McGill University, Montreal, Quebec, Canada; and Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Sara Berkelhamer
- Department of Medicine, Department of Cell and Molecular Biology, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Biology, McGill University, Montreal, Quebec, Canada; and Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Siegfried Hekimi
- Department of Medicine, Department of Cell and Molecular Biology, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Biology, McGill University, Montreal, Quebec, Canada; and Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Jianke Zhang
- Department of Medicine, Department of Cell and Molecular Biology, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Biology, McGill University, Montreal, Quebec, Canada; and Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Harris Perlman
- Department of Medicine, Department of Cell and Molecular Biology, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Biology, McGill University, Montreal, Quebec, Canada; and Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Paul T. Schumacker
- Department of Medicine, Department of Cell and Molecular Biology, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Biology, McGill University, Montreal, Quebec, Canada; and Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Manu Jain
- Department of Medicine, Department of Cell and Molecular Biology, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Biology, McGill University, Montreal, Quebec, Canada; and Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Navdeep S. Chandel
- Department of Medicine, Department of Cell and Molecular Biology, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Biology, McGill University, Montreal, Quebec, Canada; and Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
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Wu YCM, O'Reilly MA. Bcl-X(L) is the primary mediator of p21 protection against hyperoxia-induced cell death. Exp Lung Res 2010; 37:82-91. [PMID: 21128858 DOI: 10.3109/01902148.2010.521617] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A tight balance between anti- and proapoptotic members of the Bcl-2 family controls cell survival and death. Exposure to hyperoxia shifts this balance towards a prodeath state that ultimately activates Bak- and Bax-dependent cell death. Mechanisms underlying this shift are undefined; however, the cell cycle inhibitor p21 delays the loss of antiapoptotic Mcl-1 and Bcl-X(L), and protects against hyperoxia. Here, H1299 human lung adenocarcinoma cells are used to investigate how these and other members of the Bcl-2 family cooperate with p21 to protect against hyperoxia. Expression of antiapoptotic Mcl-1 and Bcl-X(L), but not Bcl-2 or A1, declined during hyperoxia, whereas proapoptotic Bak, but not Bax, increased. Conditional overexpression of p21 selectively delayed the loss of Mcl-1 and Bcl-X(L), without affecting expression of the other members. siRNA knockdown of Mcl-1 and Bcl-X(L) sensitized cells to hyperoxia, but only the loss of Bcl-X(L) ablated the protective effects of p21. Conversely, overexpression of Mcl-1 and Bcl-X(L) protected against hyperoxia, but only Bcl-X(L) bound Bak and Bax. Altogether, these data suggest that Bcl-X(L) is the primary mediator by which p21 protects against hyperoxia-induced Bak/Bax-dependent cell death.
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Affiliation(s)
- Yu-Chieh M Wu
- Department of Biomedical Genetics, School of Medicine and Dentistry, The University of Rochester, Rochester, New York 14642, USA
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25
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Lo JF, Sinkala E, Eddington DT. Oxygen gradients for open well cellular cultures via microfluidic substrates. LAB ON A CHIP 2010; 10:2394-401. [PMID: 20559583 PMCID: PMC3188960 DOI: 10.1039/c004660d] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Controlling oxygen concentration at a microscale level can benefit experimental investigations involving oxidative stress, ischemia, and reactive oxygen species (ROS) mediated cellular pathways. Here, we report the application of microfluidic gradient generation in an open-well culture model, in which a gradient of gas is delivered via diffusion through a gas permeable substrate that separates cells from the gas microchannels below. By using diffusion to localize oxygen delivery, microgradients of oxygen concentrations can be rapidly and controllably applied without exposing cells to mechanical stresses or reducing culture volumes inside microfluidic culture chambers. Furthermore, we demonstrate the modulation of intracellular ROS levels in Madin-Darby Canine Kidney (MDCK) cells by applying these oxygen microgradients. Increases in ROS levels consistent with both oxidative stress and hypoxic exposures were observed in MDCK cells. The measured ROS increases were comparable to 100 microM hydrogen peroxide exposure in a control comparison, which is within the range of standard ROS induction methods. Incubation with 200 microM vitamin C was able to demodulate the ROS response at both hypoxic and hyperoxic exposures. By providing microfluidic controlled gradients, constant ROS exposure, and a shear-free open well design, the devices introduced here greatly improve upon standard oxygen-based culturing methods.
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Affiliation(s)
- Joe F Lo
- Department of Bioengineering, University of Illinois at Chicago, 60607, USA
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26
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Métrailler-Ruchonnet I, Pagano A, Carnesecchi S, Khatib K, Herrera P, Donati Y, Bron C, Barazzone C. Bcl-2 overexpression in type II epithelial cells does not prevent hyperoxia-induced acute lung injury in mice. Am J Physiol Lung Cell Mol Physiol 2010; 299:L312-22. [DOI: 10.1152/ajplung.00212.2009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Bcl-2 is an anti-apoptotic molecule preventing oxidative stress damage and cell death. We have previously shown that Bcl-2 is able to prevent hyperoxia-induced cell death when overexpressed in a murine fibrosarcoma cell line L929. We hypothesized that its specific overexpression in pulmonary epithelial type II cells could prevent hyperoxia-induced lung injury by protecting the epithelial side of the alveolo-capillary barrier. In the present work, we first showed that in vitro Bcl-2 can rescue murine pulmonary epithelial cells (MLE12) from oxygen-induced cell apoptosis, as shown by analysis of LDH release, annexin V/propidium staining, and caspase-3 activity. We then generated transgenic mice overexpressing specifically Bcl-2 in lung epithelial type II cells under surfactant protein C (SP-C) promoter (Tg-Bcl-2) and exposed them to hyperoxia. Bcl-2 did not hinder hyperoxia-induced mitochondria and DNA oxidative damage of type II cell in vivo. Accordingly, lung damage was identical in both Tg-Bcl-2 and littermate mice strains, as measured by lung weight, bronchoalveolar lavage, and protein content. Nevertheless, we observed a significant lower number of TUNEL-positive cells in type II cells isolated from Tg-Bcl-2 mice exposed to hyperoxia compared with cells isolated from littermate mice. In summary, these results show that although Bcl-2 overexpression is able to prevent hyperoxia-induced cell death at single cell level in vitro and ex vivo, it is not sufficient to prevent cell death of parenchymal cells and to protect the lung from acute damage in mice.
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Affiliation(s)
| | - Alessandra Pagano
- Institut National de la Santé et de la Recherche Médicale UMR 911, Centre de Recherche en Oncologie biologique et en Oncopharmacologie, Université Aix-Marseille, France; and
| | - Stéphanie Carnesecchi
- Departments of 1Pediatrics and
- Pathology-Immunology, Medical School, University of Geneva, Switzerland
| | - Karim Khatib
- Pathology-Immunology, Medical School, University of Geneva, Switzerland
| | - Pedro Herrera
- Department of Genetic Medicine and Development, Medical School, University of Geneva, Switzerland
| | - Yves Donati
- Departments of 1Pediatrics and
- Pathology-Immunology, Medical School, University of Geneva, Switzerland
| | - Camille Bron
- Departments of 1Pediatrics and
- Pathology-Immunology, Medical School, University of Geneva, Switzerland
| | - Constance Barazzone
- Departments of 1Pediatrics and
- Pathology-Immunology, Medical School, University of Geneva, Switzerland
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27
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Mauth C, Pavlica S, Deiwick A, Steffen A, Bader A. The influence of oxygen supply on metabolism of neural cells cultured on a gas-permeable PTFE foil. Biotechnol Prog 2010; 26:1724-32. [PMID: 20662095 DOI: 10.1002/btpr.478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The influence of oxygen on neural stem cell proliferation, differentiation, and apoptosis is of great interest for regenerative therapies in neurodegenerative disorders, such as Parkinson's disease. These oxygen depending mechanisms have to been considered for the optimization of neural cell culture conditions. In this study, we used a cell culture system with an oxygen-permeable polytetrafluorethylene (PTFE) foil to investigate the effect of oxygen on metabolism and survival of neural cell lines in vitro. Human glial astrocytoma-derived cells (GOS-3) and rat pheochromacytoma cells (PC12) were cultured on the gas-permeable PTFE foil as well as a conventional non oxygen-permeable cell culture substrate at various oxygen concentrations. Analyses of metabolic activity, gene expression of apoptotic grade, and dopamine synthesis were performed. Under low oxygen partial pressure (2%, 5%) the anaerobic metabolism and apoptotic rate of cultured cells is diminished on PTFE foil when compared with the conventional culture dishes. In contrast, under higher oxygen atmosphere (21%) the number of apoptotic cells on the PTFE foil was enhanced. This culture model demonstrates a suitable model for the improvement of oxygen dependent metabolism under low oxygen conditions as well as for induction of oxidative stress by high oxygen atmosphere without supplementation of neurotoxins.
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Affiliation(s)
- Corinna Mauth
- Dept. of Cell Techniques and Stem Cell Biology, Biotechnological Biomedical Center, University of Leipzig, Leipzig 04103, Germany
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28
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Gore A, Muralidhar M, Espey MG, Degenhardt K, Mantell LL. Hyperoxia sensing: from molecular mechanisms to significance in disease. J Immunotoxicol 2010; 7:239-54. [PMID: 20586583 DOI: 10.3109/1547691x.2010.492254] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Oxygen therapy using mechanical ventilation with hyperoxia is necessary to treat patients with respiratory failure and distress. However, prolonged exposure to hyperoxia leads to the generation of excessive reactive oxygen species (ROS), causing cellular damage and multiple organ dysfunctions. As the lungs are directly exposed, hyperoxia can cause both acute and chronic inflammatory lung injury and compromise innate immunity. ROS may contribute to pulmonary oxygen toxicity by overwhelming redox homeostasis, altering signaling cascades that affect cell fate, ultimately leading to hyperoxia-induced acute lung injury (HALI). HALI is characterized by pronounced inflammatory responses with leukocyte infiltration, injury, and death of pulmonary cells, including epithelia, endothelia, and macrophages. Under hyperoxic conditions, ROS mediate both direct and indirect modulation of signaling molecules such as protein kinases, transcription factors, receptors, and pro- and anti-apoptotic factors. The focus of this review is to elaborate on hyperoxia-activated key sensing molecules and current understanding of their signaling mechanisms in HALI. A better understanding of the signaling pathways leading to HALI may provide valuable insights on its pathogenesis and may help in designing more effective therapeutic approaches.
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Affiliation(s)
- Ashwini Gore
- Department of Pharmaceutical Sciences, St. John's University College of Pharmacy and Allied Health Professions, Queens, NY, USA
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29
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Tyrosine phosphorylation of apoptotic proteins during hyperoxia in mitochondria of the cerebral cortex of newborn piglets. Neurochem Res 2010; 35:1003-9. [PMID: 20213344 DOI: 10.1007/s11064-010-0147-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/19/2010] [Indexed: 01/22/2023]
Abstract
The present study tests the hypothesis that hyperoxia results in increased tyrosine phosphorylation of apoptotic proteins Bcl-2, Bcl-xl, Bax & Bad in the mitochondrial fraction of the cerebral cortex of newborn piglets. Twelve newborn piglets were divided into normoxic [Nx, n = 6], exposed to a FiO(2) of 0.21 for 1 h and hyperoxic [Hyx, n = 6], exposed to FiO(2) of 1.0 for 1 h. PaO(2) in Hyx group was maintained at 400 mmHg while the Nx group was kept at 80 to 100 mmHg. The density (O.D.x mm(2)) of phosphorylated Bcl2 protein on westernblot was 19.3 +/- 3.6 in Nx and 41.5 +/- 18.3 in Hyx, (P < 0.05). The density of phosphorylated Bcl-xl protein density was 26.9 +/- 7.0 in Nx and 47.9 +/- 2.5 in Hyx, (P < 0.05). Phosphorylated Bax density was 43.5 +/- 5.0 in Nx and 43.3 +/- 5.2 in Hyx. Phosphorylated Bad density was 23.6 +/- 3.9 in Nx, 24.4 +/- 4.7 in Hyx. The data show that during hyperoxia there is a significant increase in tyrosine phosphorylation of Bcl2 and Bcl-xl, while the phosphorylation of proapototic proteins Bax & Bad was not altered. We conclude that hyperoxia leads to post translational modification of anti apoptotic proteins Bcl2 and Bcl-xl in cerebral cortical mitochondria. We propose that phosphorylation of Bcl2 will result in loss of its antiapoptotic potential by preventing its dimerization with Bax leading to activation of the caspase pathway and subsequent neuronal death in the cerebral cortex of the newborn piglets.
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30
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Staversky RJ, Vitiello PF, Yee M, Callahan LM, Dean DA, O'Reilly MA. Epithelial ablation of Bcl-XL increases sensitivity to oxygen without disrupting lung development. Am J Respir Cell Mol Biol 2009; 43:376-85. [PMID: 19880821 DOI: 10.1165/rcmb.2009-0165oc] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Recent studies indicate that the antiapoptotic Bcl-X(L), one of five isoforms expressed by the Bcl-X gene, protects a variety of cell lines exposed to hyperoxia. However, its role in lung development and protection against oxidative stress in vivo is not known. Here, we show Bcl-X(L) is the predominant isoform expressed in the lung, and the only isoform detected in respiratory epithelium. Because loss of Bcl-X(L) is embryonically lethal, Bcl-X(L) was ablated throughout the respiratory epithelium by mating mice with a floxed exon II of the Bcl-X gene with mice expressing Cre under control of the surfactant protein-C promoter. Interestingly, the loss of Bcl-X(L) in respiratory epithelium was perinatally lethal in approximately 50% of the expected offspring. However, some adult mice lacking the gene were obtained. The epithelial-specific ablation of Bcl-X(L) did not disrupt pulmonary function, the expression of epithelial cell-specific markers, or lung development. However, it shifted the lung toward a proapoptotic state, defined by a reduction in antiapoptotic Mcl-1, an increase in proapoptotic Bak, and increased sensitivity of the respiratory epithelium to hyperoxia. Intriguingly, increased 8-oxoguanine lesions seen during hyperoxia were also evident as lungs transitioned to room air at birth, a time when perinatal lethality in some mice lacking Bcl-X(L) was observed. These findings reveal that the epithelial-specific expression of Bcl-X(L) is not required for proper lung development, but functions to protect respiratory epithelial cells against oxygen-induced toxicity, such as during hyperoxia and the lung's first exposure to ambient air.
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31
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Outten C, Falk R, Culotta V. Cellular factors required for protection from hyperoxia toxicity in Saccharomyces cerevisiae. Biochem J 2009; 388:93-101. [PMID: 15641941 PMCID: PMC1186697 DOI: 10.1042/bj20041914] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Prolonged exposure to hyperoxia represents a serious danger to cells, yet little is known about the specific cellular factors that affect hyperoxia stress. By screening the yeast deletion library, we have identified genes that protect against high-O2 damage. Out of approx. 4800 mutants, 84 were identified as hyperoxia-sensitive, representing genes with diverse cellular functions, including transcription and translation, vacuole function, NADPH production, and superoxide detoxification. Superoxide plays a significant role, since the majority of hyperoxia-sensitive mutants displayed cross-sensitivity to superoxide-generating agents, and mutants with compromised SOD (superoxide dismutase) activity were particularly vulnerable to hyperoxia. By comparison, factors known to guard against H2O2 toxicity were poorly represented amongst hyperoxia-sensitive mutants. Although many cellular components are potential targets, our studies indicate that mitochondrial glutathione is particularly vulnerable to hyperoxia damage. During hyperoxia stress, mitochondrial glutathione is more susceptible to oxidation than cytosolic glutathione. Furthermore, two factors that help maintain mitochondrial GSH in the reduced form, namely the NADH kinase Pos5p and the mitochondrial glutathione reductase (Glr1p), are critical for hyperoxia resistance, whereas their cytosolic counterparts are not. Our findings are consistent with a model in which hyperoxia toxicity is manifested by superoxide-related damage and changes in the mitochondrial redox state.
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Affiliation(s)
- Caryn E. Outten
- Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, 615 N. Wolfe St. Room 7032, Baltimore, MD 21205, U.S.A
| | - Robert L. Falk
- Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, 615 N. Wolfe St. Room 7032, Baltimore, MD 21205, U.S.A
| | - Valeria C. Culotta
- Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, 615 N. Wolfe St. Room 7032, Baltimore, MD 21205, U.S.A
- To whom correspondence should be addressed (email )
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32
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Zhang M, Lin L, Lee SJ, Mo L, Cao J, Ifedigbo E, Jin Y. Deletion of caveolin-1 protects hyperoxia-induced apoptosis via survivin-mediated pathways. Am J Physiol Lung Cell Mol Physiol 2009; 297:L945-53. [PMID: 19767411 DOI: 10.1152/ajplung.00081.2009] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hyperoxia-induced lung injury is an established model that mimics human acute respiratory distress syndrome. Cell death is a prominent feature in lungs following prolonged hyperoxia. Caveolae are omega-shaped invaginations of the plasma membrane. Caveolin-1 (cav-1), a 22-kDa transmembrane scaffolding protein, is the principal structural component of caveolae. We have recently shown that deletion of cav-1 (cav-1-/-) protected against hyperoxia-induced cell death and lung injury both in vitro and in vivo; however, the mechanisms remain unclear. Survivin, a member of the inhibitor of apoptosis protein family, inhibits apoptosis in tumor cells. Although emerging evidence suggests that survivin is involved in wound healing, especially in vascular injuries, its role in hyperoxia-induced lung injury has not been investigated. Our current data demonstrated that hyperoxia induced apoptosis via suppressing survivin expression. Deletion of cav-1 abolished this suppression and subsequently protected against hyperoxia-induced apoptosis. Using "gain" and "loss" of function assays, we determined that survivin protected lung cells from hyperoxia-induced apoptosis via the inhibition of apoptosis executor caspase-3. Overexpression of survivin by deletion of cav-1 was regulated by Egr-1. Egr-1 functioned as a negative regulator of survivin expression. Deletion of cav-1 upregulated survivin via decreased Egr-1 binding of the survivin promoter region. Together, this study illustrates the effect of hyperoxia on survivin expression and the role of survivin in hyperoxia-induced apoptosis. We also demonstrate that deletion of cav-1 protects hyperoxia-induced apoptosis via modulation of survivin expression.
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Affiliation(s)
- Meng Zhang
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, MUH 628NW, 3459 5th Ave., Pittsburgh, PA 15213, USA
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33
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The effect of 100% oxygen on intestinal preservation and recovery following ischemia-reperfusion injury in rats*. Crit Care Med 2009; 37:1054-61. [DOI: 10.1097/ccm.0b013e31819d0f5c] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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34
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Urich D, Soberanes S, Burgess Z, Chiarella SE, Ghio AJ, Ridge KM, Kamp DW, Chandel NS, Mutlu GM, Budinger GRS. Proapoptotic Noxa is required for particulate matter-induced cell death and lung inflammation. FASEB J 2009; 23:2055-64. [PMID: 19237507 DOI: 10.1096/fj.08-114546] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Elevated ambient levels of particulate matter air pollution are associated with excess daily mortality, largely attributable to increased rates of cardiovascular events. We have previously reported that particulate matter induces p53-dependent apoptosis in primary human alveolar epithelial cells. Activation of the intrinsic apoptotic pathway by p53 often requires the transcription of the proapoptotic Bcl-2 proteins Noxa, Puma, or both. In this study, we exposed alveolar epithelial cells in culture and mice to fine particulate matter <2.5 microm in diameter (PM(2.5)) collected from the ambient air in Washington, D. C. Exposure to PM(2.5) induced apoptosis in primary alveolar epithelial cells from wild-type but not Noxa(-/-) mice. Twenty-four hours after the intratracheal instillation of PM(2.5), wild-type mice showed increased apoptosis in the lung and increased levels of mRNA encoding Noxa but not Puma. These changes were associated with increased permeability of the alveolar-capillary membrane and inflammation. All of these findings were absent or attenuated in Noxa(-/-) animals. We conclude that PM(2.5)-induced cell death requires Noxa both in vitro and in vivo and that Noxa-dependent cell death might contribute to PM-induced alveolar epithelial dysfunction and the resulting inflammatory response.
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Affiliation(s)
- Daniela Urich
- Feinberg School of Medicine, Northwestern University, Division of Pulmonary and Critical Care Medicine, 240 E. Huron, Chicago, IL 60611, USA
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35
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Effect of hyperoxia on serine phosphorylation of apoptotic proteins in mitochondrial membranes of the cerebral cortex of newborn piglets. Neurochem Res 2009; 34:1219-25. [PMID: 19169818 DOI: 10.1007/s11064-008-9898-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/17/2008] [Indexed: 10/21/2022]
Abstract
Previous studies have shown that hyperoxia results in cerebral cortical neuronal apoptosis. Studies have also shown that phosphorylation of anti-apoptotic proteins Bcl-2 and Bcl-xl results in loss of their anti-apoptotic potential leading to alteration in mitochondrial membrane permeability and the release of apoptogenic proteins in the neuronal cell of the newborn piglets. The present study tests the hypothesis that cerebral hyperoxia will result in increased serine phosphorylation of apoptotic proteins Bcl-2, Bcl-xl, Bax, and Bad in the mitochondrial membranes of the cerebral cortex of newborn piglets. Twelve newborn piglets were divided into normoxic (Nx, n = 6) exposed to an FiO(2) of 0.21 for 1 h and hyperoxic (Hyx, n = 6) exposed to FiO(2) of 1.0 for 1 h. In the Hyx group, PaO(2) was maintained above 400 mmHg while the Nx group was kept at 80-100 mmHg. Cerebral cortical tissue was harvested and mitochondrial fractions were isolated. Mitochondrial membrane proteins were separated using 12% SDS-PAGE, and probed with anti-serine phosphorylated Bcl-2, Bcl-xl, Bax, and Bad antibodies. Protein bands were detected, analyzed by imaging densitometry and density expressed as absorbance (OD x mm(2)). Phosphorylated Bcl-2 (p-Bcl-2) protein density (OD x mm(2)) was 81.81 +/- 9.24 in Nx and 158.34 +/- 10.66 in Hyx (P < 0.05). Phosphorylated Bcl-xl (p-Bcl-xl) protein density was 52.98 +/- 3.59 in Nx and 99.62 +/- 18.22 in Hyx (P < 0.05). Phosphorylated Bax (p-Bax) protein was 161.13 +/- 6.27 in Nx and 174.21 +/- 15.95 in Hyx (P = NS). Phosphorylated Bad (p-Bad) protein was 166.24 +/- 9.47 in Nx 155.38 +/- 12.32 in Hyx (P = NS). The data show that there is a significant increase in serine phosphorylation of Bcl-2 and Bcl-xl proteins while phosphorylation of Bad and Bax proteins were not altered during hyperoxia in the mitochondrial fraction of the cerebral cortex of newborn piglets. We conclude that hyperoxia results in differential post-translational modification of anti-apoptotic proteins Bcl-2 and Bcl-xl as compared to pro-apoptotic proteins Bax and Bad in mitochondria. We speculate that phosphorylation of Bcl-2 and Bcl-xl will result in loss of their anti-apoptotic potential by preventing their dimerization with Bax leading to activation of the caspase cascade of neuronal death.
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36
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Vitiello PF, Wu YCM, Staversky RJ, O’Reilly MA. p21(Cip1) protects against oxidative stress by suppressing ER-dependent activation of mitochondrial death pathways. Free Radic Biol Med 2009; 46:33-41. [PMID: 18948188 PMCID: PMC2631574 DOI: 10.1016/j.freeradbiomed.2008.09.022] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Revised: 08/04/2008] [Accepted: 09/11/2008] [Indexed: 01/23/2023]
Abstract
Although it is well established that the cell cycle inhibitor p21 protects against genotoxic stress by preventing the replication of damaged DNA, recent studies have shown that the cytoplasmic form can also protect. It protects by delaying the loss of the antiapoptotic proteins Mcl-1 and Bcl-X(L); however, the mechanism of regulation is unknown. Utilizing hyperoxia as a model of chronic oxidative stress and DNA damage, p21 was detected in the nucleus and cytoplasm and cytoplasmic expression of p21 was sufficient for cytoprotection. p21 was enriched in a subcellular fraction containing mitochondria and endoplasmic reticulum (ER), suggesting that it may be coordinating ER and mitochondrial stress pathways. Consistent with this, p21 suppressed hyperoxic downregulation of BiP and subsequent activation of ER stress signaling, which affected Mcl-1, but not Bcl-X(L); though both inhibited hyperoxic cell death. Taken together, these data show that p21 integrates the DNA damage response with ER stress signaling, which then regulates mitochondrial death pathways during chronic genotoxic stress.
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Affiliation(s)
- Peter F. Vitiello
- Department of Environmental Medicine, The University of Rochester, Rochester, NY 14642
- Department of Pediatrics, The University of Rochester, Rochester, NY 14642
| | - Yu-Chieh M. Wu
- Department of Biomedical Genetics, The University of Rochester, Rochester, NY 14642
| | | | - Michael A. O’Reilly
- Department of Environmental Medicine, The University of Rochester, Rochester, NY 14642
- Department of Pediatrics, The University of Rochester, Rochester, NY 14642
- Address Correspondence to: Michael A. O’Reilly, Ph.D., Department of Pediatrics, Box 850, The University of Rochester, 601 Elmwood Avenue, Rochester, NY 14642, Tel: (585) 275-5948, Fax: (585) 756-7780,
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37
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Susnow N, Zeng L, Margineantu D, Hockenbery DM. Bcl-2 family proteins as regulators of oxidative stress. Semin Cancer Biol 2008. [PMID: 19138742 DOI: 10.1016/j.semcancer.2008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The Bcl-2 family of proteins includes pro- and anti-apoptotic factors acting at mitochondrial and microsomal membranes. An impressive body of published studies, using genetic and physical reconstitution experiments in model organisms and cell lines, supports a view of Bcl-2 proteins as the critical arbiters of apoptotic cell death decisions in most circumstances (excepting CD95 death receptor signaling in Type I cells). Evasion of apoptosis is one of the hallmarks of cancer [Hanahan D, Weinberg RA. The hallmarks of cancer. Cell 2000;100:57-70], relevant to tumorigenesis as well as resistance to cytotoxic drugs, and deregulation of Bcl-2 proteins is observed in many cancers [Manion MK, Hockenbery DM. Targeting BCL-2-related proteins in cancer therapy. Cancer Biol Ther. 2003;2:S105-14; Olejniczak ET, Van Sant C, Anderson MG, Wang G, Tahir SK, Sauter G, et al. Integrative genomic analysis of small-cell lung carcinoma reveals correlates of sensitivity to bcl-2 antagonists and uncovers novel chromosomal gains. Mol Cancer Res. 2007;5:331-9]. The rekindled interest in aerobic glycolysis as a cancer trait raises interesting questions as to how metabolic changes in cancer cells are integrated with other essential alterations in cancer, e.g. promotion of angiogenesis and unbridled growth signals. Apoptosis induced by multiple different signals involves loss of mitochondrial homeostasis, in particular, outer mitochondrial membrane integrity, releasing cytochrome c and other proteins from the intermembrane space. This integrative process, controlled by Bcl-2 family proteins, is also influenced by the metabolic state of the cell. In this review, we consider the role of reactive oxygen species, a metabolic by-product, in the mitochondrial pathway of apoptosis, and the relationships between Bcl-2 functions and oxidative stress.
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Affiliation(s)
- Nathan Susnow
- Department of Medicine, University of Washington, Seattle, 98195-6424, United States
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38
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Bcl-2 family proteins as regulators of oxidative stress. Semin Cancer Biol 2008; 19:42-9. [PMID: 19138742 DOI: 10.1016/j.semcancer.2008.12.002] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Accepted: 12/13/2008] [Indexed: 12/22/2022]
Abstract
The Bcl-2 family of proteins includes pro- and anti-apoptotic factors acting at mitochondrial and microsomal membranes. An impressive body of published studies, using genetic and physical reconstitution experiments in model organisms and cell lines, supports a view of Bcl-2 proteins as the critical arbiters of apoptotic cell death decisions in most circumstances (excepting CD95 death receptor signaling in Type I cells). Evasion of apoptosis is one of the hallmarks of cancer [Hanahan D, Weinberg RA. The hallmarks of cancer. Cell 2000;100:57-70], relevant to tumorigenesis as well as resistance to cytotoxic drugs, and deregulation of Bcl-2 proteins is observed in many cancers [Manion MK, Hockenbery DM. Targeting BCL-2-related proteins in cancer therapy. Cancer Biol Ther. 2003;2:S105-14; Olejniczak ET, Van Sant C, Anderson MG, Wang G, Tahir SK, Sauter G, et al. Integrative genomic analysis of small-cell lung carcinoma reveals correlates of sensitivity to bcl-2 antagonists and uncovers novel chromosomal gains. Mol Cancer Res. 2007;5:331-9]. The rekindled interest in aerobic glycolysis as a cancer trait raises interesting questions as to how metabolic changes in cancer cells are integrated with other essential alterations in cancer, e.g. promotion of angiogenesis and unbridled growth signals. Apoptosis induced by multiple different signals involves loss of mitochondrial homeostasis, in particular, outer mitochondrial membrane integrity, releasing cytochrome c and other proteins from the intermembrane space. This integrative process, controlled by Bcl-2 family proteins, is also influenced by the metabolic state of the cell. In this review, we consider the role of reactive oxygen species, a metabolic by-product, in the mitochondrial pathway of apoptosis, and the relationships between Bcl-2 functions and oxidative stress.
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Wright CJ, Zhuang T, La P, Yang G, Dennery PA. Hyperoxia-induced NF-kappaB activation occurs via a maturationally sensitive atypical pathway. Am J Physiol Lung Cell Mol Physiol 2008; 296:L296-306. [PMID: 19074556 DOI: 10.1152/ajplung.90499.2008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
NF-kappaB activation is exaggerated in neonatal organisms after oxidant and inflammatory insults, but the reason for this and the downstream effects are unclear. We hypothesized that specific phosphorylation patterns of IkappaBalpha could account for differences in NF-kappaB activation in hyperoxia-exposed fetal and adult lung fibroblasts. After exposure to hyperoxia (>95% O(2)), nuclear NF-kappaB binding increased in fetal, but not adult, lung fibroblasts. Unique to fetal cells, phosphorylation of IkappaBalpha on tyrosine 42, rather than serine 32/36 as seen in TNF-alpha-exposed cells, preceded NF-kappaB nuclear translocation. In fetal cells stably transfected with an NF-kappaB-driven luciferase reporter, hyperoxia significantly suppressed reporter activity, in contrast to increased reporter activity after TNF-alpha incubation. Targeted gene profiling analysis showed that hyperoxia resulted in decreased expression of multiple genes, including proapoptotic factors. Transfection with a dominant-negative IkappaBalpha (Y42F), which cannot be phosphorylated on tyrosine 42, resulted in upregulation of multiple proapoptotic genes. In support of this finding, caspase-3 activity and DNA laddering were specifically increased in fetal lung fibroblasts expressing Y42F after exposure to hyperoxia. These data demonstrate a unique pathway of NF-kappaB activation in fetal lung fibroblasts after exposure to hyperoxia, whereby these cells are protected against apoptosis. Activation of this pathway in fetal cells may prevent the normal pattern of fibroblast apoptosis necessary for normal lung development, resulting in aberrant lung morphology in vivo.
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Affiliation(s)
- Clyde J Wright
- Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
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Soberanes S, Urich D, Baker CM, Burgess Z, Chiarella SE, Bell EL, Ghio AJ, De Vizcaya-Ruiz A, Liu J, Ridge KM, Kamp DW, Chandel NS, Schumacker PT, Mutlu GM, Budinger GRS. Mitochondrial complex III-generated oxidants activate ASK1 and JNK to induce alveolar epithelial cell death following exposure to particulate matter air pollution. J Biol Chem 2008; 284:2176-86. [PMID: 19033436 DOI: 10.1074/jbc.m808844200] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We have previously reported that airborne particulate matter air pollution (PM) activates the intrinsic apoptotic pathway in alveolar epithelial cells through a pathway that requires the mitochondrial generation of reactive oxygen species (ROS) and the activation of p53. We sought to examine the source of mitochondrial oxidant production and the molecular links between ROS generation and the activation of p53 in response to PM exposure. Using a mitochondrially targeted ratiometric sensor (Ro-GFP) in cells lacking mitochondrial DNA (rho0 cells) and cells stably expressing a small hairpin RNA directed against the Rieske iron-sulfur protein, we show that site III of the mitochondrial electron transport chain is primarily responsible for fine PM (PM2.5)-induced oxidant production. In alveolar epithelial cells, the overexpression of SOD1 prevented the PM2.5-induced ROS generation from the mitochondria and prevented cell death. Infection of mice with an adenovirus encoding SOD1 prevented the PM2.5-induced death of alveolar epithelial cells and the associated increase in alveolar-capillary permeability. Treatment with PM2.5 resulted in the ROS-mediated activation of the oxidant-sensitive kinase ASK1 and its downstream kinase JNK. Murine embryonic fibroblasts from ASK1 knock-out mice, alveolar epithelial cells transfected with dominant negative constructs against ASK1, and pharmacologic inhibition of JNK with SP600125 (25 microM) prevented the PM2.5-induced phosphorylation of p53 and cell death. We conclude that particulate matter air pollution induces the generation of ROS primarily from site III of the mitochondrial electron transport chain and that these ROS activate the intrinsic apoptotic pathway through ASK1, JNK, and p53.
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Affiliation(s)
- Saul Soberanes
- Division of Pulmonary and Critical Care Medicine, The Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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Klimova TA, Bell EL, Shroff EH, Weinberg FD, Snyder CM, Dimri GP, Schumacker PT, Budinger GRS, Chandel NS. Hyperoxia-induced premature senescence requires p53 and pRb, but not mitochondrial matrix ROS. FASEB J 2008; 23:783-94. [PMID: 18948382 DOI: 10.1096/fj.08-114256] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Senescence is a potential tumor-suppressing mechanism and a commonly used model of cellular aging. One current hypothesis to explain senescence, based in part on the correlation of oxygen with senescence, postulates that it is caused by oxidative damage from reactive oxygen species (ROS). Here, we further test this theory by determining the mechanisms of hyperoxia-induced senescence. Exposure to 70% O(2) led to stress-induced, telomere-independent senescence. Although hyperoxia elevated mitochondrial ROS production, overexpression of antioxidant proteins was not sufficient to prevent hyperoxia-induced senescence. Hyperoxia activated AMPK; however, overexpression of a kinase-dead mutant of LKB1, which prevented AMPK activation, did not prevent hyperoxia-induced senescence. Knocking down p21 via shRNA, or suppression of the p16/pRb pathway by either BMI1 or HPV16-E7 overexpression, was also insufficient to prevent hyperoxia-induced senescence. However, suppressing p53 function resulted in partial rescue from senescence, suggesting that hyperoxia-induced senescence involves p53. Suppressing both the p53 and pRb pathways resulted in almost complete protection, indicating that both pathways cooperate in hyperoxia-induced senescence. Collectively, these results indicate a ROS-independent but p53/pRb-dependent senescence mechanism during hyperoxia.
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Affiliation(s)
- Tatyana A Klimova
- Department of Medicine, Northwestern University, Chicago, Illinois, USA
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Xue H, Jin L, Jin L, Zhang P, Li D, Xia Y, Lu Y, Xu Y. Neuroprotection of aucubin in primary diabetic encephalopathy. ACTA ACUST UNITED AC 2008; 51:495-502. [DOI: 10.1007/s11427-008-0069-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2007] [Accepted: 03/26/2008] [Indexed: 11/28/2022]
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Vitiello PF, Staversky RJ, Keng PC, O’Reilly MA. PUMA inactivation protects against oxidative stress through p21/Bcl-XL inhibition of bax death. Free Radic Biol Med 2008; 44:367-74. [PMID: 18215742 PMCID: PMC2276618 DOI: 10.1016/j.freeradbiomed.2007.09.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Revised: 09/05/2007] [Accepted: 09/21/2007] [Indexed: 01/10/2023]
Abstract
The tumor suppressor protein p53 activates growth arrest and proapoptotic genes in response to DNA damage. It is known that negative feedback by p21(Cip1/Waf1/Sdi1) represses p53-dependent transactivation of PUMA. The current study investigates PUMA feedback on p53 during oxidative stress from hyperoxia and the subsequent effects on cell survival mediated through p21 and Bcl-X(L). Deletion of PUMA in HCT116 colon carcinoma cells increased levels of p53 and p21, resulting in a larger G(1) population during hyperoxia. P21-dependent increase in Bcl-X(L) levels protected PUMA-deficient cells against hyperoxic cell death. Bax and Bak were both able to promote hyperoxic cell death. Bcl-X(L) protection against hyperoxic death was lost in cells lacking Bax, not PUMA, suggesting that Bcl-X(L) acts to inhibit Bax-dependent death. These results indicate that PUMA exerts a negative feedback on p53 and p21, leading to p21-dependent growth suppressive and survival changes. Enhanced survival was associated with increased Bcl-X(L) to block Bax activated cell death during oxidative stress.
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Affiliation(s)
- Peter F. Vitiello
- Department of Environmental Medicine, School of Medicine and Dentistry, The University of Rochester, Rochester NY 14642
| | - Rhonda J. Staversky
- Department of Pediatrics, School of Medicine and Dentistry, The University of Rochester, Rochester NY 14642
| | - Peter C. Keng
- Department of Radiation Oncology, School of Medicine and Dentistry, The University of Rochester, Rochester NY 14642
| | - Michael A. O’Reilly
- Department of Pediatrics, School of Medicine and Dentistry, The University of Rochester, Rochester NY 14642
- Address Correspondence to: Michael A. O’Reilly, Ph.D., Department of Pediatrics, Box 850, The University of Rochester, School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester NY 14642, Tel: (585) 275-5948, Fax: (585) 756-7780,
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Esquibies AE, Bazzy-Asaad A, Ghassemi F, Nishio H, Karihaloo A, Cantley LG. VEGF attenuates hyperoxic injury through decreased apoptosis in explanted rat embryonic lung. Pediatr Res 2008; 63:20-5. [PMID: 18043510 DOI: 10.1203/pdr.0b013e31815b4857] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Ambient oxygen concentration and vascular endothelial growth factor (VEGF)-A are vital in lung development. Since hypoxia stimulates VEGF-A production and hyperoxia reduces it, we hypothesized that VEGF-A down-regulation by exposure of airways to hyperoxia may result in abnormal lung development. An established model of in vitro rat lung development was used to examine the effects of hyperoxia on embryonic lung morphogenesis and VEGF-A expression. Under physiologic conditions, lung explant growth and branching is similar to that seen in vivo. However, in hyperoxia (50% O2) the number of terminal buds and branch length was significantly reduced after 4 d of culture. This effect correlated with a significant increase in cellular apoptosis and decrease in proliferation compared with culture under physiologic conditions. mRNA for Vegf164 and Vegf188 was reduced during hyperoxia and addition of VEGF165, but not VEGF121, to explants grown in 50% O2 resulted in partial reversal of the decrease in lung branching, correlating with a decrease in cell apoptosis. Thus, hyperoxia suppresses VEGF-A expression and inhibits airway growth and branching. The ability of exogenous VEGF165 to partially reverse apoptotic effects suggests this may be a potential approach for the prevention of hyperoxic injury.
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Affiliation(s)
- Americo E Esquibies
- Department of Pediatrics, Section of Respiratory Medicine, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
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Yanai R, Liu Y, Ko JA, Nishida T. Effects of ambient oxygen concentration on the proliferation and viability of cultured human corneal epithelial cells. Exp Eye Res 2007; 86:412-8. [PMID: 18187131 DOI: 10.1016/j.exer.2007.11.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2007] [Revised: 10/13/2007] [Accepted: 11/26/2007] [Indexed: 11/27/2022]
Abstract
Ambient oxygen (O(2)) affects the metabolism and other functions of corneal epithelial cells. The effects of O(2) concentration on the proliferation and viability of corneal epithelial cells in culture were investigated. Simian virus 40-transformed human corneal epithelial (HCE) cells were maintained at 37 degrees C in a humidified incubator containing 5% CO(2) and 95% air. The cells were subsequently transferred to a multigas incubator and exposed to 5% CO(2) and either 1, 21, or 60% O(2) plus 94, 74, or 35% N(2), respectively. Cell proliferation was evaluated by determination of cell number and measurement of the incorporation of bromodeoxyuridine. Cell lysis was quantified by measurement of the release of lactate dehydrogenase. Apoptosis was evaluated by flow cytometric analysis of cells stained with annexin V and propidium iodide as well as by immunoblot analysis of cleavage of caspase-7. The phosphorylation (activation) of Akt was also detected by immunoblot analysis. Hyperoxia (60% O(2)) inhibited the increase in cell number and the incorporation of bromodeoxyuridine apparent in HCE cells exposed to normoxia (21% O(2)). It also induced the release of lactate dehydrogenase, an increase in the proportion of apoptotic (annexin V(+), propidium iodide(-)) cells, the cleavage of caspase-7, and the phosphorylation of Akt. None of these effects was observed in cells exposed to hypoxia (1% O(2)). The amounts of the cleaved forms of caspase-3, 6, and 9 did not differ among HCE cells cultured under 1, 21, or 60% O(2). These results indicate that hyperoxia inhibited the proliferation of, and induced death by apoptosis in, cultured human corneal epithelial cells. The antiapoptotic protein Akt was also activated in cells exposed to hyperoxia, possibly reflecting a protective response to oxygen toxicity.
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Affiliation(s)
- Ryoji Yanai
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube City, Yamaguchi, Japan.
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Yamada T, Iwasaki Y, Nagata K, Fushiki S, Nakamura H, Marunaka Y, Yodoi J. Thioredoxin-1 protects against hyperoxia-induced apoptosis in cells of the alveolar walls. Pulm Pharmacol Ther 2007; 20:650-9. [PMID: 17045827 DOI: 10.1016/j.pupt.2006.07.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2006] [Revised: 07/21/2006] [Accepted: 07/31/2006] [Indexed: 11/19/2022]
Abstract
BACKGROUND The mechanisms of hyperoxia-induced lung injury remain poorly defined. Thioredoxin-1 (TRX-1) is a small ubiquitous protein that acts as an important radical scavenger. We investigated the effect of TRX-1 on apoptosis in hyperoxia-induced lung injury. METHODS Mice were exposed to 98% O(2) to produce a model of hyperoxia-induced lung injury. Using transgenic mice overexpressing human TRX-1 (hTRX-1), we assessed lung structure (n=4 per group), immunohistochemical staining for 8-hydroxy-deoxyguanosine (n=4 per group), TUNEL staining (n=5 per group), cytokine (n=5 per group) of IL-1beta and IL-6, and protein (n=6 per group) and m-RNA levels (n=4 per group) (or both) of cytochrome c, Bcl-2, Bax, p21, and p53 in the lungs. RESULTS After exposure to hyperoxia, hTRX-1 transgenic mice had significantly decreased alveolar damage. The apoptotic index was significantly lower in hTRX-1 transgenic mice than in wild-type (WT) mice after exposure to hyperoxia. Protein expression of cytochrome c in the lung was significantly lower in hTRX-1 transgenic mice than in WT mice after exposure to hyperoxia. Protein expression and m-RNA levels of Bcl-2 in the lung were significantly higher in hTRX-1 transgenic mice than in WT mice after exposure to hyperoxia. TRX-1 had no effect on the protein and m-RNA levels of Bax and p21. The protein and m-RNA levels of p53 was unaffected by hyperoxia in hTRX-1 transgenic mice. The cytokine level of IL-6 was significantly higher in hTRX-1 transgenic mice than in WT mice after exposure to hyperoxia. TRX-1 had no effect on cytokine level of IL-1beta. CONCLUSIONS These findings suggest that overexpression of hTRX-1 protects against hyperoxia-induced apoptosis in cells of the alveolar walls. The up-regulating Bcl-2 protein is considered to be one of antiapoptotic effects of TRX-1 in hyperoxia-induced lung injury.
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Affiliation(s)
- Tadaaki Yamada
- Department of Respiratory Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan.
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Abstract
PURPOSE OF REVIEW Hyperoxic inspired gas is essential for patients with hypoxic respiratory failure; it is also suspected, however, as a contributor to the pathogenesis of acute lung injury. Several recent studies in humans, animals, and cell culture have identified mechanisms by which hyperoxia may exert deleterious effects on critically ill patients. This review identifies relevant new findings regarding hyperoxic lung injury in the context of providing guidance for future clinical studies. RECENT FINDINGS Recent studies have clarified the roles of both receptor-mediated and mitochondrial cell death pathways in experimental hyperoxic lung injury. Studies in animals demonstrate that hyperoxia interacts with mechanical stretch to augment ventilator-induced lung injury. Finally, studies in humans implicate hyperoxia in impairment of host defense responses to infections. SUMMARY Although hyperoxia has not been conclusively identified as a clinically important cause of lung injury in humans, animal data strongly implicate it. Reports of interaction effects between hyperoxia and both mechanical ventilation and host defense suggest that clinical studies of hyperoxia must take these variables into account. Accumulating data about how hyperoxia initiates cell death provide guidance for development of both biomarkers to identify hyperoxia-induced injury and pharmacological interventions to limit hyperoxia's adverse effects.
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Affiliation(s)
- William A Altemeier
- Department of Medicine, University of Washington, Seattle, Washington 98195-6522, USA.
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Bhandari V, Choo-Wing R, Homer RJ, Elias JA. Increased hyperoxia-induced mortality and acute lung injury in IL-13 null mice. THE JOURNAL OF IMMUNOLOGY 2007; 178:4993-5000. [PMID: 17404281 DOI: 10.4049/jimmunol.178.8.4993] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
IL-13 is a critical effector at sites of Th2 inflammation and remodeling. As a result, anti-IL-13-based therapies are being actively developed to treat a variety of diseases and disorders. However, the beneficial effects of endogenous IL-13 in the normal and diseased lung have not been adequately defined. We hypothesized that endogenous IL-13 is an important regulator of oxidant-induced lung injury and inflammation. To test this hypothesis, we compared the effects of 100% O(2) in mice with wild-type and null IL-13 loci. In this study, we demonstrate that hyperoxia significantly augments the expression of the components of the IL-13R, IL-13Ralpha1, and IL-4Ralpha. We also demonstrate that, in the absence of IL-13, hyperoxia-induced tissue inflammation is decreased. In contrast, in the IL-13 null mice, DNA injury, cell death, caspase expression, and activation and mortality are augmented. Interestingly, the levels of the cytoprotective cytokines vascular endothelial cell growth factor, IL-6, and IL-11 were decreased in the bronchoalveolar lavage fluid. These studies demonstrate that the expression of the IL-13R is augmented and that the endogenous IL-13-IL-13R pathway contributes to the induction of inflammation and the inhibition of injury in hyperoxic acute lung injury.
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Affiliation(s)
- Vineet Bhandari
- Division of Perinatal Medicine, Yale University School of Medicine, Department of Pediatrics, Children's Hospital, New Haven, CT 06520, USA
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Chandel NS, Budinger GRS. The cellular basis for diverse responses to oxygen. Free Radic Biol Med 2007; 42:165-74. [PMID: 17189822 DOI: 10.1016/j.freeradbiomed.2006.10.048] [Citation(s) in RCA: 165] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Revised: 09/27/2006] [Accepted: 10/24/2006] [Indexed: 11/22/2022]
Abstract
Mammalian cells have divergent responses to varying oxygen levels. Cells exposed to low oxygen levels (hypoxia) activate the transcription factor hypoxia-inducible factor-1 (HIF-1) as an adaptive response. Cells exposed to hypoxia do not undergo senescence or cell death and do not diminish ATP levels. By contrast, cells exposed to high oxygen levels (hyperoxia) undergo senescence and cell death and decrease their ATP levels, yet do not activate HIF-1. Despite these divergent responses with respect to senescence, cell death, metabolism, and gene expression, the signaling events in both systems are mediated by the generation of mitochondrial-derived reactive oxygen species (ROS). This perspective reviews the role of signaling through mitochondrial ROS in hypoxic and hyperoxic environments.
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Affiliation(s)
- Navdeep S Chandel
- Department of Medicine and Department of Cell & Molecular Biology, Northwestern University, McGaw Pavilion M-334, 240 East Huron Avenue, Chicago, IL 60611, USA
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Budinger GRS, Sznajder JI. The alveolar-epithelial barrier: a target for potential therapy. Clin Chest Med 2007; 27:655-69; abstract ix. [PMID: 17085253 DOI: 10.1016/j.ccm.2006.06.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
During acute lung injury (ALI), the alveolar-capillary barrier is damaged, resulting in the accumulation of fluid and protein in the alveolar space characteristic of the acute respiratory distress syndrome (ARDS). Disordered epithelial repair may contribute to the development of fibrosis and worsen outcomes in patients who have lung injury. This article discusses novel emerging therapies based on these mechanisms that are designed to preserve the function and promote the repair of the alveolar epithelium in patients who have ALI/ARDS.
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Affiliation(s)
- G R Scott Budinger
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, IL 60611, USA
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