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Chen SJ, Tsai CC, Lin SR, Lee MH, Huang SS, Zeng HY, Wang LH, Chiang MF, Sheu HM, Chang NS. Dissociation of the nuclear WWOX/TRAF2 switch renders UV/cold shock-mediated nuclear bubbling cell death at low temperatures. Cell Commun Signal 2024; 22:505. [PMID: 39420317 PMCID: PMC11487720 DOI: 10.1186/s12964-024-01866-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2024] [Accepted: 10/02/2024] [Indexed: 10/19/2024] Open
Abstract
BACKGROUND Normal cells express functional tumor suppressor WW domain-containing oxidoreductase (WWOX), designated WWOXf. UV irradiation induces WWOXf cells to undergo bubbling cell death (BCD) - an event due to the accumulation of nuclear nitric oxide (NO) gas that forcefully pushes the nuclear and cell membranes to form one or two bubbles at room temperature (22 °C) and below. In contrast, when WWOX-deficient or -dysfunctional (WWOXd) cells are exposed to UV and/or cold shock, the cells undergo nuclear pop-out explosion death (POD). We aimed to determine the morphological and biochemical changes in WWOXf cells during BCD versus apoptosis. METHODS WWOXf and WWOXd cells were exposed to UV followed by measuring BCD or POD by time-lapse microscopy and/or time-lapse holographic microscopy at 4, 22, or 37 °C to visualize morphological changes. Live cell stains were used to measure the kinetics of nitric oxide (NO) production and Ca2+ influx. Extent of cell death was measured by uptake of propidium iodide and by internucleosomal DNA fragmentation using agarose gel electrophoresis. RESULTS WWOXf cells were exposed to UV and then cold shock, or cold shock and then UV, and cultured at 4, 10, and 22 °C, respectively. Initially, UV induced calcium influx and NO production, which led to nuclear bubbling and final death. Cold shock pretreatment completely suppressed UV-mediated bubbling at 37 °C, so the UV/cold shock-treated cells underwent apoptosis. Without cold shock, UV only induced bubbling at all temperatures, whereas the efficiency of bubbling at 37 °C was reduced by greater than 50%. Morphologically, the WWOXf cell height or thickness was significantly increased during cell division or apoptosis, but the event did not occur in BCD. In comparison, when WWOXd cancer cells received UV or UV/cold shock, these cells underwent NO-independent POD. UV/cold shock effectively downregulated the expression of many proteins such as the housekeeping α-tubulin (> 70%) and β-actin (< 50%), and cortactin (> 70%) in WWOXf COS7 cells. UV/cold shock induced relocation of α-tubulin to the nucleus and nuclear bubbles in damaged cells. UV induced co-translocation of the WWOX/TRAF2 complex to the nuclei, in which the prosurvival TRAF2 blocked the proapoptotic WWOX via its zinc finger domain. Without WWOX, TRAF2 did not relocate to the nuclei. Cold shock caused the dissociation of the WWOX/TRAF2 complex in the nucleus needed for BCD. In contrast, the formation of the WWOX/TRAF2 complex, plus p53, was strengthened at 37 °C required for apoptosis. CONCLUSIONS The temperature-sensitive nuclear WWOX/TRAF2 complex acts as a molecular switch, whose dissociation favors BCD at low temperatures, and the association supports apoptosis at 37 °C in UV-treated WWOXf cells.
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Affiliation(s)
- Szu-Jung Chen
- Institute of Molecular Medicine, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Cheng-Chang Tsai
- Institute of Molecular Medicine, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Sing-Ru Lin
- Institute of Molecular Medicine, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Ming-Hui Lee
- Institute of Molecular Medicine, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Shenq-Shyang Huang
- Institute of Molecular Medicine, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Han-Yan Zeng
- Graduate Institute of Biomedical Sciences, College of Medicine, China Medical University, Taichung, 40402, Taiwan
| | - Lu-Hai Wang
- Chinese Medicine Research Center, Institute of Integrated Medicine, China Medical University, Taichung, 40402, Taiwan
| | - Ming-Fu Chiang
- Department of Neurosurgery, Fu Jen Catholic University Hospital, Taipei, 24352, Taiwan.
| | - Hamm-Ming Sheu
- Department of Dermatology, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan.
| | - Nan-Shan Chang
- Institute of Molecular Medicine, National Cheng Kung University, Tainan, 70101, Taiwan.
- Graduate Institute of Biomedical Sciences, College of Medicine, China Medical University, Taichung, 40402, Taiwan.
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Sotiropoulos JX, Oei JL. The role of oxygen in the development and treatment of bronchopulmonary dysplasia. Semin Perinatol 2023; 47:151814. [PMID: 37783577 DOI: 10.1016/j.semperi.2023.151814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
Oxygen (O2) is crucial for both the development and treatment of one of the most important consequences of prematurity: bronchopulmonary dysplasia (BPD). In fetal life, the hypoxic environment is important for alveolar development and maturation. After birth, O2 becomes a double-edged sword. While O2 is needed to prevent hypoxia, it also causes oxidative stress leading to a plethora of morbidities, including retinopathy and BPD. The advent of continuous O2 monitoring with pulse oximeters has allowed clinicians to recognize the narrow therapeutic margins of oxygenation for the preterm infant, but more knowledge is needed to understand what these ranges are at different stages of the preterm infant's life, including at birth, in the neonatal intensive care unit and after hospital discharge. Future research, especially in innovative technologies such as automated O2 control and remote oximetry, will improve the understanding and treatment of the O2 needs of infants with BPD.
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Affiliation(s)
- J X Sotiropoulos
- School of Women's and Children's Health, Faculty of Medicine, University of New South Wales, Australia; Department of Newborn Care, The Royal Hospital for Women, Randwick, New South Wales, Australia; NHMRC Clinical Trials Centre, Faculty of Medicine and Health, University of Sydney, Australia
| | - J L Oei
- School of Women's and Children's Health, Faculty of Medicine, University of New South Wales, Australia; Department of Newborn Care, The Royal Hospital for Women, Randwick, New South Wales, Australia; NHMRC Clinical Trials Centre, Faculty of Medicine and Health, University of Sydney, Australia.
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Jamal M, Masood A, Belcastro R, Lopez L, Li J, Belik J, Jankov RP, Keith Tanswell A. Lipid hydroperoxide formation regulates postnatal rat lung cell apoptosis and alveologenesis. Free Radic Biol Med 2013. [PMID: 23195685 DOI: 10.1016/j.freeradbiomed.2012.11.012] [Citation(s) in RCA: 189] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An acute increase in oxygen tension after birth imposes an oxidative stress upon the lung. We hypothesized that the resultant increase in reactive oxygen species, specifically lipid hydroperoxides, would trigger postnatal alveologenesis and physiological lung cell apoptosis in the neonatal rat. Neonatal rats were either untreated or treated daily with subcutaneous vehicle or diphenyl phenyl diamine, a scavenger of lipid hydroperoxides and inhibitor of lipid peroxidation, from day 1 to 6 of life. Alveolar formation and physiological lung cell apoptosis were assessed by morphometry, immunohistochemistry, and Western blot analyses on day 7 samples. Substitution experiments were conducted using the prototypic lipid hydroperoxide t-butylhydroperoxide. At a minimum effective dose of 15μg/g body wt, treatment with diphenyl phenyl diamine resulted in a significant increase in tissue fraction and mean linear intercept and significant reductions in small peripheral blood vessels, secondary crest formation, lung and secondary crest cell DNA synthesis, and estimated alveolar number. Decreased numbers of apoptotic type II pneumocytes and mesenchymal cells, and decreased contents of proapoptotic cleaved caspase-3 and -7 and cytoplasmic cytochrome c, and an increase in antiapoptotic Bcl-xL were found in lungs treated with diphenyl phenyl diamine. A prevention of selected changes induced by diphenyl phenyl diamine was observed with concurrent treatment with intraperitoneal t-butylhydroperoxide, at a minimally effective dose of 187μg/g body wt. We conclude that oxidative stress after birth induces lipid hydroperoxide formation, which, in turn, triggers postnatal alveologenesis and physiological lung cell apoptosis in the neonatal rat.
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Affiliation(s)
- Mobin Jamal
- Lung Biology Programme, Physiology & Experimental Medicine, Hospital for Sick Children Research Institute, Toronto, ON M5G 1X8, Canada
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4
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Alphonse RS, Rajabali S, Thébaud B. Lung injury in preterm neonates: the role and therapeutic potential of stem cells. Antioxid Redox Signal 2012; 17:1013-40. [PMID: 22400813 DOI: 10.1089/ars.2011.4267] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Continuous improvements in perinatal care have allowed the survival of ever more premature infants, making the task of protecting the extremely immature lung from injury increasingly challenging. Premature infants at risk of developing chronic lung disease or bronchopulmonary dysplasia (BPD) are now born at the late canalicular stage of lung development, just when the airways become juxtaposed to the lung vasculature and when gas-exchange becomes possible. Readily available strategies, including improved antenatal management (education, regionalization, steroids, and antibiotics), together with exogenous surfactant and exclusive/early noninvasive ventilatory support, will likely decrease the incidence/severity of BPD over the next few years. Nonetheless, because of the extreme immaturity of the developing lung, the extent to which disruption of lung growth after prematurity and neonatal management lead to an earlier or more aggravated decline in respiratory function in later life is a matter of concern. Consequently, much more needs to be learned about the mechanisms of lung development, injury, and repair. Recent insight into stem cell biology has sparked interest for stem cells to repair damaged organs. This review summarizes the exciting potential of stem cell-based therapies for lung diseases in general and BPD in particular.
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Chen JX, O’Mara PW, Poole SD, Brown N, Ehinger NJ, Slaughter JC, Paria BC, Aschner JL, Reese J. Isoprostanes as physiological mediators of transition to newborn life: novel mechanisms regulating patency of the term and preterm ductus arteriosus. Pediatr Res 2012; 72:122-8. [PMID: 22565502 PMCID: PMC3586272 DOI: 10.1038/pr.2012.58] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Increased oxygen tension at birth regulates physiologic events that are essential to postnatal survival, but the accompanying oxidative stress may also generate isoprostanes. We hypothesized that isoprostanes regulate ductus arteriosus (DA) function during postnatal vascular transition. METHODS Isoprostanes were measured by gas chromatography-mass spectrometry. DA tone was assessed by pressure myography. Gene expression was measured by quantitative PCR. RESULTS Oxygen exposure was associated with increased 8-iso-prostaglandin (PG)F2α in newborn mouse lungs. Both 8-iso-PGE2 and 8-iso-PGF2α induced concentration-dependent constriction of the isolated term DA, which was reversed by the thromboxane A2 (TxA2) receptor antagonist SQ29548. SQ29548 pretreatment unmasked an isoprostane-induced DA dilation mediated by the EP4 PG receptor. Exposure of the preterm DA to 8-iso-PGE2 caused unexpected DA relaxation that was reversed by EP4 antagonism. In contrast, exposure to 8-iso-PGF2α caused preterm DA constriction via TxA2 receptor activation. Further investigation revealed the predominance of the TxA2 receptor at term, whereas the EP4 receptor was expressed and functionally active from mid-gestation onward. CONCLUSION This study identifies a novel physiological role for isoprostanes during postnatal vascular transition and provide evidence that oxidative stress may act on membrane lipids to produce vasoactive mediators that stimulate physiological DA closure at birth or induce pathological patency of the preterm DA.
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Affiliation(s)
- Jian-Xiong Chen
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Patrick W. O’Mara
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee
| | - Stanley D. Poole
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee
| | - Naoko Brown
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee
| | - Noah J. Ehinger
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee
| | - James C. Slaughter
- Department of Biostatistics, Vanderbilt University, Nashville, Tennessee
| | - Bibhash C. Paria
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee
| | - Judy L. Aschner
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee
| | - Jeff Reese
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee;,Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee
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6
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Abstract
Reactive oxygen species (ROS) serve as cell signaling molecules for normal biologic processes. However, the generation of ROS can also provoke damage to multiple cellular organelles and processes, which can ultimately disrupt normal physiology. An imbalance between the production of ROS and the antioxidant defenses that protect cells has been implicated in the pathogenesis of a variety of diseases, such as cancer, asthma, pulmonary hypertension, and retinopathy. The nature of the injury will ultimately depend on specific molecular interactions, cellular locations, and timing of the insult. This review will outline the origins of endogenous and exogenously generated ROS. The molecular, cellular, pathologic, and physiologic targets will then be discussed with a particular emphasis on aspects relevant to child development. Finally, antioxidant defenses that scavenge ROS and mitigate associated toxicities will be presented, with a discussion of potential therapeutic approaches for the prevention and/or treatment of human diseases using enzymatic and nonenzymatic antioxidants.
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Affiliation(s)
- Richard L Auten
- Department of Pediatrics, Duke Medical Center, Durham, NC 27710, USA
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Jankov RP, Kantores C, Pan J, Belik J. Contribution of xanthine oxidase-derived superoxide to chronic hypoxic pulmonary hypertension in neonatal rats. Am J Physiol Lung Cell Mol Physiol 2008; 294:L233-45. [DOI: 10.1152/ajplung.00166.2007] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Xanthine oxidase (XO)-derived reactive oxygen species (ROS) formation contributes to experimental chronic hypoxic pulmonary hypertension in adults, but its role in neonatal pulmonary hypertension has received little attention. In rats chronically exposed to hypoxia (13% O2) for 14 days from birth, we examined the effects of ROS scavengers (U74389G 10 mg·kg−1·day−1 or Tempol 100 mg·kg−1·day−1 ip) or a XO inhibitor, Allopurinol (50 mg·kg−1·day−1 ip). Both ROS scavengers limited oxidative stress in the lung and attenuated hypoxia-induced vascular remodeling, confirming a critical role for ROS in this model. However, both interventions also significantly inhibited somatic growth and normal cellular proliferation in distal air spaces. Hypoxia-exposed pups had evidence of increased serum and lung XO activity, increased vascular XO-derived superoxide production, and vascular nitrotyrosine formation. These changes were all prevented by treatment with Allopurinol, which also attenuated hypoxia-induced vascular remodeling and partially reversed inhibited endothelium-dependent arterial relaxation, without affecting normal growth and proliferation. Collectively, our findings suggest that XO-derived superoxide induces endothelial dysfunction, thus impairing pulmonary arterial relaxation, and contributes to vascular remodeling in hypoxia-exposed neonatal rats. Due to the potential for adverse effects on normal growth, targeting XO may represent a superior “antioxidant” strategy to ROS scavengers for neonates with pulmonary hypertension.
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Liao L, Ning Q, Li Y, Wang W, Wang A, Wei W, Liu X, Auten RL, Tanswell AK, Luo X. CXCR2 blockade reduces radical formation in hyperoxia-exposed newborn rat lung. Pediatr Res 2006; 60:299-303. [PMID: 16923948 DOI: 10.1203/01.pdr.0000233058.08200.d6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Inflammation contributes greatly to the pathogenesis of bronchopulmonary dysplasia. In previous studies, we showed that blocking neutrophil influx by treatment with SB265610, a selective CXCR2 antagonist, could partly reduce superoxide accumulation and preserve alveolar development in 60% O(2)-exposed newborn rats. The purpose of this study was to further investigate the role of neutrophils in the formation of reactive oxygen and nitrogen species mediating hyperoxia-impaired lung development. We found that hydroxyl radical formation and lipid peroxidation in rat lungs were significantly increased during 60% O(2) exposure. These increases were attenuated by the administration of SB265610. In addition, SB265610 largely inhibited protein nitration induced by hyperoxia. SB265610 partly prevented the hyperoxia-enhanced bronchoalveolar lavage (BAL) protein content in 60% O(2)-exposed animals. Our results demonstrate that neutrophils have a pivotal role in hydroxyl radical formation, lipid peroxidation and protein nitration. Taken together with our previous studies, the present findings show that blocking neutrophil influx protects alveolar development and improves lung function in part by preventing reactive oxygen/nitrogen species accumulation.
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Affiliation(s)
- Lingjie Liao
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
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9
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Yi M, Jankov RP, Belcastro R, Humes D, Copland I, Shek S, Sweezey NB, Post M, Albertine KH, Auten RL, Tanswell AK. Opposing Effects of 60% Oxygen and Neutrophil Influx on Alveologenesis in the Neonatal Rat. Am J Respir Crit Care Med 2004; 170:1188-96. [PMID: 15347560 DOI: 10.1164/rccm.200402-215oc] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The lungs of newborn rats exposed to 60% oxygen for 14 days develop an injury that shares morphologic similarities to human bronchopulmonary dysplasia (BPD). Neutrophil influx into the lung, as part of an inflammatory response, may play a pivotal role in the development of BPD. A neutrophil chemokine, cytokine-induced neutrophil chemoattractant-1, which signals through the neutrophil CXC chemokine receptor-2, is increased in the lung tissue of newborn rats exposed to 60% oxygen. The purpose of this study was to explore the role of neutrophils in the rat model of BPD by inhibiting neutrophil influx using SB265610, a selective CXC chemokine receptor-2 antagonist. SB265610, administered to 60% oxygen-exposed newborn rats from birth to 14 days, completely inhibited neutrophil influx. It also attenuated increased production of reactive oxygen species in newborn rat lung tissue after exposure to 60% oxygen for 4 days. Lung morphometric analysis revealed that 60% oxygen for 14 days, when accompanied by treatment with SB265610 to prevent neutrophil accumulation, increased alveolar formation over that seen in newborn rats exposed to air. These data suggest that exposure of the neonatal lung to moderate hyperoxia may enhance postnatal lung growth, provided postnatal pulmonary inflammation is suppressed.
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Affiliation(s)
- Man Yi
- Lung Biology Programme, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada
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10
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Abstract
In the cell, reducing and oxidizing molecules modulate the redox state. In embryonic and fetal growth, increased oxidative stress may be detrimental, but an oxidized state can also be beneficial. This is because redox may also affect key transcription factors that can alter gene expression during development. In addition, redox may impact on placentation and amniotic membrane integrity during pregnancy. Lastly, diseases of prematurity, such as necrotizing enterocolitis, retinopathy of prematurity, and chronic lung disease, may be modulated by redox in the premature. Because antioxidant therapies have not necessarily modified the outcome of these diseases, some debate exists as to this. Nonetheless, sufficient evidence suggests a role for redox throughout embryonic, fetal, and postnatal development. This evidence will be explored here.
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Affiliation(s)
- Phyllis A Dennery
- Department of Pediatrics, University of Pennsylvania, Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
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11
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Laffey JG, Jankov RP, Engelberts D, Tanswell AK, Post M, Lindsay T, Mullen JB, Romaschin A, Stephens D, McKerlie C, Kavanagh BP. Effects of Therapeutic Hypercapnia on Mesenteric Ischemia–Reperfusion Injury. Am J Respir Crit Care Med 2003; 168:1383-90. [PMID: 14644926 DOI: 10.1164/rccm.2108078] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Hypercapnic acidosis protects against direct lung injury in in vivo and ex vivo models, however, lung injury/acute respiratory distress syndrome commonly occurs after a nonpulmonary etiology. We investigated whether therapeutic hypercapnia (TH)-deliberate elevation of carbon dioxide (CO2) tension-would protect against lung injury after splanchnic ischemia-reperfusion injury in an in vivo model. TH was associated with preservation of lung mechanics, attenuation of protein leakage, and improved oxygenation compared with control conditions. Lung protection was therapeutic as well as prophylactic. Protection was dose-dependent, but inspired CO2 concentrations above 5.0% were associated with little additional lung protection. Before lung injury, increasing FICO2 resulted in a dose-dependent increase in PaO2. Lung protection with hypercapnia occurred despite pulmonary artery pressures that were greater than observed with normocapnia. Reperfusion increased lipid peroxidation (tissue 8-isoprostane concentration) in the bowel, liver, and lung, and caused histologically apparent bowel injury; however, none of these effects was altered by TH. Therefore, TH-induced by adding CO2 to inspired gas-provides consistent protection against lung injury in terms of lung permeability, oxygenation, and lung mechanics after mesenteric ischemia-reperfusion. These data further support the emerging evidence for ongoing physiologic study of TH at the bedside.
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Affiliation(s)
- John G Laffey
- Department of Critical Care Medicine, The Research Institute, The Hospital for Sick Children, Toronto, ON, Canada
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12
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Nelin LD, Morrisey JF, Effros RM, Dawson CA, Schapira RM. The effect of inhaled nitric oxide and oxygen on the hydroxylation of salicylate in rat lungs. Pediatr Res 2003; 54:337-43. [PMID: 12788987 DOI: 10.1203/01.pdr.0000079183.85517.ce] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Inhaled nitric oxide (iNO) is used as a selective pulmonary vasodilator, and often under conditions when a high fraction of inspired oxygen is indicated. However, little is known about the potential toxicity of iNO therapy with or without concomitant oxygen therapy. NO can combine with superoxide (O2-) to form peroxynitrite (ONOO-), which can in turn decompose to form hydroxyl radical (OH.). Both OH. and ONOO- are involved in various forms of lung injury. To begin evaluation of the effect of iNO under either normoxic or hyperoxic conditions on OH. and/or ONOO- formation, rats were exposed for 58 h to either 21% O2, 21% O2 + 10 parts per million (ppm) NO, 21% O2 + 100 ppm NO, 50% O2, 90% O2, 90% O2 + 10 ppm NO, or 90% O2 + 100 ppm NO. We used a salicylate hydroxylation assay to detect the effects of these exposures on lung OH. and/or ONOO- formation measured as the appearance of 2,3-dihydroxybenzoic acid (2,3-DHBA). Exposure to 90% O2 and 90% O2 + 100 ppm NO resulted in significantly (p < 0.05) greater lung wet weight (1.99 +/- 0.14 g and 3.14 +/- 0.30 g, respectively) compared with 21% O2 (1.23 +/- 0.01 g). Exposure to 21% O2 + 100 ppm NO led to 2.5 times the control (21% O2 alone) 2,3 DHBA formation (p < 0.05) and exposure to 90% O2 led to 2.4 times the control 2,3-DHBA formation (p < 0.05). However, with exposure to both 90% O2 and 100 ppm NO, the 2,3-DHBA formation was no greater than the control condition (21% O2). Thus, these results indicate that, individually, both the hyperoxia and the 100 ppm NO led to greater salicylate hydroxylation, but that the combination of hyperoxia and 100 ppm NO led to less salicylate hydroxylation than either did individually. The production of OH. and/or ONOO- in the lung during iNO therapy may depend on the ratio of NO to O2.
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Affiliation(s)
- Leif D Nelin
- Department of Pediatrics, Medical College of Wisconsin, and Research Service, Zablocki VA Medical Center, Milwaukee, USA.
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13
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Jankov RP, Luo X, Campbell A, Belcastro R, Cabacungan J, Johnstone L, Frndova H, Lye SJ, Tanswell AK. Fibroblast growth factor receptor-1 and neonatal compensatory lung growth after exposure to 95% oxygen. Am J Respir Crit Care Med 2003; 167:1554-61. [PMID: 12626345 DOI: 10.1164/rccm.200207-662oc] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Neonatal rats exposed to 95% oxygen (O2) for 7 days from birth had inhibited lung growth, DNA synthesis, and secondary septation. These parameters were rapidly restored by a period of recovery in air. Northern and Western blot analysis and immunohistochemistry were used to screen for the fibroblast growth factor receptor-1 (FGF-R1) and its high affinity ligand, basic fibroblast growth factor (bFGF), which could have a role in this recovery process. Expression of bFGF in the lung was significantly reduced at the end of the 7-day exposure to 95% O2 and was increased after 3 days of recovery in air. Expression of FGF-R1 was not affected by exposure to 95% O2 or recovery in air. We hypothesized that the increase in bFGF after removal from 95% O2, acting through the FGF-R1, would be critical for compensatory growth. Intraperitoneal injection of soluble truncated FGF-R1 at the onset of the recovery phase arrested compensatory lung DNA synthesis and secondary septation seen in control animals after 3 days of recovery, confirming a role for FGF-R1 in this model of compensatory neonatal lung growth.
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Affiliation(s)
- Robert P Jankov
- Division of Neonatology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8 Canada
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14
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Saugstad OD. Bronchopulmonary dysplasia-oxidative stress and antioxidants. SEMINARS IN NEONATOLOGY : SN 2003; 8:39-49. [PMID: 12667829 DOI: 10.1016/s1084-2756(02)00194-x] [Citation(s) in RCA: 217] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
There is increasing evidence that oxidative stress is implicated in the development of bronchopulmonary dysplasia. Several important factors contribute to augmented oxidative stress in the newborn and especially the preterm infant: first, because of its immaturity, the lung of preterm infants is frequently exposed to oxygen therapy and hyperoxia. Second, the antioxidant defense and its ability to be induced during an hyperoxic challenge are impaired. Third, the preterm infant has an increased susceptibility to infection and inflammation, which increases oxidative stress. Fourth, free iron, which catalyzes the production of toxic reactive oxygen species, can be detected in preterm infants. The molecular and cellular mechanisms for free radical-induced injury are now understood in more detail, and it is clear that oxidative stress plays an important role in triggering apoptosis, in serving as second messenger and in signal transduction. This new insight might lead to novel and efficient therapies. So far, there has been no significant breakthrough regarding antioxidant therapies. Care should, however, be exercised in supplementing the preterm infant with antioxidants since this may affect growth and development.
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Affiliation(s)
- Ola Didrik Saugstad
- Department of Pediatric Research, Rikshospitalet, University of Oslo, Norway.
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15
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Jankov RP, Belcastro R, Ovcina E, Lee J, Massaeli H, Lye SJ, Tanswell AK. Thromboxane A(2) receptors mediate pulmonary hypertension in 60% oxygen-exposed newborn rats by a cyclooxygenase-independent mechanism. Am J Respir Crit Care Med 2002; 166:208-14. [PMID: 12119234 DOI: 10.1164/rccm.200112-124oc] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Endothelin-1 (ET-1) mediates the development of pulmonary hypertension (PHT) in newborn rats exposed to 60% O(2) for 14 days, a model for human chronic neonatal lung injury. ET-1 production by d-14 rat pulmonary artery smooth muscle cells in vitro was markedly increased by thromboxane (TX) A(2) receptor agonists and inhibited by a competitive antagonist. We hypothesized that stimulation of the TX A(2) receptor contributed to O(2)-mediated PHT in vivo. Newborn rat pups received daily intraperitoneal injections of L670596, a competitive TX A(2) receptor antagonist, or 5,5-dimethyl-3-(3-fluorophenyl)4-(4-methylsulfonyl)phenyl-2(5H)-furanone (DFU), a cyclooxygenase-2 inhibitor, during 14 days of 60% O(2) or air exposure. L670596, but not DFU, prevented 60% O(2)-mediated right ventricular and small pulmonary vessel smooth muscle hypertrophy. Lung ET-1 content was significantly reduced by L670596 in 60% O(2)-exposed animals. We conclude that TX A(2) receptor activation, though not by TX A(2), caused upregulation of ET-1 and PHT in this model. A likely mediator is the stable lipid peroxidation product, 8-iso-prostane, which acts as an incidental ligand of the TX A(2) receptor and is a potent inducer of ET-1 production by cultured d-14 rat pulmonary artery smooth muscle cells in vitro.
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MESH Headings
- 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid/pharmacology
- Animals
- Animals, Newborn
- Blotting, Western
- Carbazoles/pharmacology
- Cells, Cultured
- Cyclooxygenase Inhibitors/pharmacology
- Dinoprost/analogs & derivatives
- Endothelin-1/metabolism
- F2-Isoprostanes/metabolism
- F2-Isoprostanes/pharmacology
- Furans/pharmacology
- Hypertension, Pulmonary/metabolism
- Hypertension, Pulmonary/physiopathology
- Hypertrophy, Right Ventricular/physiopathology
- Immunohistochemistry
- Lung/metabolism
- Muscle, Smooth, Vascular/metabolism
- Oxygen/physiology
- Oxygen/toxicity
- Prostaglandin Antagonists/pharmacology
- Prostaglandin-Endoperoxide Synthases/physiology
- Pulmonary Artery/metabolism
- Rats
- Receptors, Thromboxane/antagonists & inhibitors
- Receptors, Thromboxane/physiology
- Thromboxane B2/metabolism
- Up-Regulation
- Vasoconstrictor Agents/pharmacology
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Affiliation(s)
- Robert P Jankov
- Canadian Institutes of Health Research Group in Lung Development, Lung Biology Programme, Toronto, Ontario, Canada
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16
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Auten RL, Whorton MH, Nicholas Mason S. Blocking neutrophil influx reduces DNA damage in hyperoxia-exposed newborn rat lung. Am J Respir Cell Mol Biol 2002; 26:391-7. [PMID: 11919074 DOI: 10.1165/ajrcmb.26.4.4708] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Hyperoxia-induced neutrophil infux in neonatal rats may contribute to impaired lung development through oxidative DNA damage. To determine whether blocking neutrophil influx prevents DNA damage, we treated newborn rats with 95% O2 beginning at birth, and at 3 and 4 d with nonimmune immunoglobulin G (IgG) (control) or anti-cytokine-induced neutrophil chemoattractant (CINC). At 8 d, lungs were inflation-fixed. Random sections were labeled using terminal transferase nick end-labeling (TUNEL), and DNA oxidation was measured using anti-8-OH-2'-deoxyguanosine (OHdG). To determine whether hyperoxia-induced TUNEL represented apoptosis, we labeled sections with anti-Bax (proapoptotic) and anti-Bcl-2 (antiapoptotic). We labled additional sections with anti-M30, directed against an epitope formed by caspase 6 digestion of cytokeratin 18 during apoptosis. Hyperoxia induced marked increases in TUNEL and OHdG signal in lung parenchymal cells, which was substantially prevented by treatment with anti-CINC. The large effects of hyperoxia on TUNEL were not accompanied by substantial effects on Bax, Bcl-2, or M30. We conclude that neutrophil influx during hyperoxia damages DNA by nicking and oxidation, and that blocking neutrophil influx can prevent this. Effects of 95% O2 on TUNEL are not primarily due to apoptosis in this model. Neutrophil-mediated oxidative DNA damage may contribute to abnormal lung development in newborns subjected to significant oxidative stress.
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Affiliation(s)
- Richard L Auten
- Neonatal-Perinatal Research Institute, Division of Neonatal Medicine, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina 27710, USA.
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17
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Abstract
Reactive oxygen and nitrogen species are considered to play a major role in the pathogenesis of a wide range of human disorders. This may be a particularly important pathogenetic mechanism in the newborn nursery. The phrase "oxygen radical disease of prematurity" has been coined to collectively describe a wide range of neonatal disorders based on the belief that premature newborns are deficient in antioxidant defenses at a time when they are subjected to acute and chronic oxidant stresses. This belief has led to a number of clinical trials of antioxidant therapies being undertaken in neonatal patients. The realization that reactive oxygen species play a critical role in neonatal illnesses has only recently been paralleled by an increased understanding of their physiologic roles. A major concern is that effective scavenging of reactive oxygen species, to attenuate their toxic effects, will also inhibit essential cellular functions such as growth in potential target organs such as lung, brain, intestine, and retina.
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Affiliation(s)
- R P Jankov
- Canadian Institutes of Health Research Group in Lung Development and Lung Biology Programme, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
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18
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Jankov RP, Luo X, Belcastro R, Copland I, Frndova H, Lye SJ, Hoidal JR, Post M, Tanswell AK. Gadolinium chloride inhibits pulmonary macrophage influx and prevents O(2)-induced pulmonary hypertension in the neonatal rat. Pediatr Res 2001; 50:172-83. [PMID: 11477200 DOI: 10.1203/00006450-200108000-00003] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Newborn rats exposed to 60% O(2) for 14 d demonstrated a bronchopulmonary dysplasia-like lung morphology and pulmonary hypertension. A 21-aminosteroid antioxidant, U74389G, attenuated both pulmonary hypertension and macrophage accumulation in the O(2)-exposed lungs. To determine whether macrophage accumulation played an essential role in the development of pulmonary hypertension in this model, pups were treated with gadolinium chloride (GdCl(3)) to reduce lung macrophage content. Treatment of 60% O(2)-exposed animals with GdCl(3) prevented right ventricular hypertrophy (p < 0.05) and smooth muscle hyperplasia around pulmonary vessels, but had no effect on morphologic changes in the lung parenchyma. In addition, GdCl(3) inhibited 60% O(2)-mediated increases in endothelin-1, 8-isoprostane, and nitrotyrosine residues. Organotypic cultures of fetal rat distal lung cells were subjected to cyclical mechanical strain to assess the potential role of GdCl(3)-induced blockade of stretch-mediated cation channels in these effects. Mechanical strain caused a moderate increase of endothelin-1 (p < 0.05), which was unaffected by GdCl(3), but had no effect on 8-isoprostane or nitric oxide synthesis. A critical role for endothelin-1 in O(2)-mediated pulmonary hypertension was confirmed using the combined endothelin receptor antagonist SB217242. We concluded that pulmonary macrophage accumulation, in response to 60% O(2), mediated pulmonary hypertension through up-regulation of endothelin-1.
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MESH Headings
- Animals
- Animals, Newborn
- Bronchopulmonary Dysplasia/etiology
- Bronchopulmonary Dysplasia/pathology
- Cell Movement/drug effects
- Cells, Cultured
- Dinoprost/analogs & derivatives
- Dinoprost/metabolism
- Endothelin-1/metabolism
- F2-Isoprostanes
- Gadolinium/pharmacology
- Humans
- Hypertension, Pulmonary/etiology
- Hypertension, Pulmonary/pathology
- Hypertension, Pulmonary/prevention & control
- Hypertrophy, Right Ventricular/etiology
- Hypertrophy, Right Ventricular/pathology
- Infant, Newborn
- Macrophages, Alveolar/drug effects
- Macrophages, Alveolar/pathology
- Macrophages, Alveolar/physiology
- Oxygen/toxicity
- Rats
- Rats, Sprague-Dawley
- Tyrosine/analogs & derivatives
- Tyrosine/metabolism
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Affiliation(s)
- R P Jankov
- Canadian Institutes of Health Research Groups in Lung Development, Toronto, Ontario, Canada
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19
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Auten RL, Mason SN, Tanaka DT, Welty-Wolf K, Whorton MH. Anti-neutrophil chemokine preserves alveolar development in hyperoxia-exposed newborn rats. Am J Physiol Lung Cell Mol Physiol 2001; 281:L336-44. [PMID: 11435208 DOI: 10.1152/ajplung.2001.281.2.l336] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Inflammation may contribute to lung injury and impaired alveolar development in bronchopulmonary dysplasia. We treated hyperoxia-exposed newborn rats with antibodies to the neutrophil chemokine cytokine-induced neutrophil chemoattractant-1 (CINC-1) during 95% O2 exposure to reduce adverse effects of hyperoxia-induced inflammation on lung development. Rats were exposed at birth to air, 95% O2, or 95% O2 + anti-CINC-1 (injected on days 3 and 4). Bromodeoxyuridine (BrdU) was injected 6 h before death. Anti-CINC-1 treatment improved weight gain but not survival at day 8. Anti-CINC-1 reduced bronchoalveolar lavage neutrophils at day 8 to levels equal to air controls. Total detectable lung CINC-1 was reduced to air control levels. Lung compliance was improved by anti-CINC-1, achieving air control levels in the 10-microg anti-CINC-1 group. Anti-CINC-1 preserved proliferating cell nuclear antigen expression in airway epithelium despite 95% O2 exposure. BrdU incorporation was depressed by hyperoxia but preserved by anti-CINC-1 to levels similar to air control. Alveolar volume and surface density were decreased by hyperoxia but preserved by anti-CINC-1 to levels equal to air control. Blockade of neutrophil influx in newborns may avert early lung injury and avoid alveolar developmental arrest that contributes to bronchopulmonary dysplasia.
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Affiliation(s)
- R L Auten
- Division of Neonatal Medicine, Department of Pediatrics, Neonatal-Perinatal Research Institute, Durham, North Carolina 27710, USA.
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20
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Abstract
An increasing number of articles related to free radicals in the newborn period is published. The hypothesis that there exists a socalled 'Oxygen radical disease of neonatology' has not been proven but an increasing body of evidence seems to indicate that free radicals are involved in several disease processes leading to conditions such as chronic lung disease, retinopathy of prematurity, necrotizing enterocolitis and periventricular leukomalacia. There are also accumulating data implying the involvement of reactive oxygen species and oxidative stress in signal transduction and they therefore perhaps affect growth and development. In the last year there have been no new breakthroughs in antioxidant therapy.
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Affiliation(s)
- O D Saugstad
- Department of Pediatric Research, The National Hospital, University of Oslo, Norway.
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21
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Laffey JG, Tanaka M, Engelberts D, Luo X, Yuan S, Tanswell AK, Post M, Lindsay T, Kavanagh BP. Therapeutic hypercapnia reduces pulmonary and systemic injury following in vivo lung reperfusion. Am J Respir Crit Care Med 2000; 162:2287-94. [PMID: 11112153 DOI: 10.1164/ajrccm.162.6.2003066] [Citation(s) in RCA: 178] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Permissive hypercapnia, involving tolerance to elevated Pa(CO(2)), is associated with reduced acute lung injury (ALI), thought to result from reduced mechanical stretch, and improved outcome in ARDS. However, deliberately elevating inspired CO(2) concentration alone (therapeutic hypercapnia, TH) protects against ALI in ex vivo models. We investigated whether TH would protect against ALI in an in vivo model of lung ischemia-reperfusion (IR). Anesthetized open chest rabbits were ventilated (standard eucapnic settings), and were randomized to TH (FI(CO(2)) 0.12) versus control (FI(CO(2)) 0.00). Pa(CO(2)) and arterial pH values achieved in the TH versus CON groups were 101 +/- 3 versus 44.4 +/- 4 mm Hg and 7.10 +/- 0.03 versus 7.37 +/- 0.03, respectively. Following left lung ischemia and reperfusion, TH versus control was associated with preservation of lung mechanics, attenuation of protein leakage, reduction in pulmonary edema, and improved oxygenation. Indices of systemic protection included improved acid-base and lactate profile, in the absence of systemic hypoxemia. In the TH group, mean BALF TNF-alpha levels were 3.5% of CON levels (p < 0.01), and mean 8-isoprostane levels were 30% of CON levels (p = 0.02). Western blot analysis demonstrated reduced lung tissue nitrotyrosine in TH, indicating attenuation of tissue nitration. Finally, preliminary data suggest that TH may attenuate apoptosis following lung IR. We conclude that in the current model TH is protective versus IR lung injury and mechanisms of protection include preservation of lung mechanics, attenuation of pulmonary inflammation, and reduction of free radical mediated injury. If these findings are confirmed in additional models, TH may become a candidate for clinical testing in critical care.
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Affiliation(s)
- J G Laffey
- The Lung Biology Programme, The Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
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22
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Jankov RP, Luo X, Cabacungan J, Belcastro R, Frndova H, Lye SJ, Tanswell AK. Endothelin-1 and O2-mediated pulmonary hypertension in neonatal rats: a role for products of lipid peroxidation. Pediatr Res 2000; 48:289-98. [PMID: 10960492 DOI: 10.1203/00006450-200009000-00005] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We hypothesized that reactive O2 species, or their intermediary products, generated during exposure to elevated O2 lead to pathologic endothelin-1 expression in the newborn lung. Endothelin-1 expression and 8-isoprostane content (an in vivo marker of lipid peroxidation) were examined and found to be elevated (p < 0.05) in the lungs of newborn rats with abnormal lung morphology and pulmonary hypertension, as assessed by right ventricular hypertrophy, after a 14-d exposure to 60% O2. The antioxidant and lipid hydroperoxide scavenger, U74389G (10 mg/kg), given by daily i.p. injection prevented O2-dependent right ventricular hypertrophy (p < 0.05 compared with vehicle-treated controls), but had no effect on abnormal lung morphology. Additionally, we observed that 8-isoprostane caused marked endothelin-1 mRNA up-regulation in vitro in primary rat fetal lung cell cultures. We conclude that reactive O2 species, or their bioactive intermediaries, are causative in O2-mediated pulmonary hypertension and endothelin-1 up-regulation. It is likely that the bioactive lipid peroxidation product, 8-isoprostane, plays a key role in pathologic endothelin-1 expression and pulmonary hypertension during oxidant stress.
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Affiliation(s)
- R P Jankov
- Medical Research Council Group in Lung Development and Lung Biology Programme, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
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