Divergent regulation of vascular endothelial growth factor and of erythropoietin gene expression in vivo. Sandner P,Gess B,Wolf K,Kurtz A Pflugers Archiv : European journal of physiology There is accumulating evidence from in vitro experiments that the gene expression of the vascular endothelial growth factor (VEGF) is, like that of the erythropoietin (EPO) gene, regulated by the oxygen tension and by divalent cations such as cobalt. Since the information about the regulation of VEGF gene expression in vivo is rather scarce, this study aimed to examine the influence of hypoxia and of cobalt on VEGF gene expression in different rat organs and to compare it with that on EPO gene expression. To this end male Sprague-Dawley rats were exposed to carbon monoxide (0.1% CO), hypoxia (8% O2 ) or to cobalt chloride (12 and 60 mg/kg s.c.) for 6 h. mRNA levels for VEGF- 188, -164, and -120 amino acid isoforms in lungs, hearts, kidneys and livers were semiquantitated by RNase protection. For these organs we found a rank order of VEGF mRNA abundance of lung >> heart > kidney = liver. EPO mRNA levels were semiquantitated in kidneys and livers. Hypoxia, CO and cobalt increased EPO mRNA levels 60-fold, 140-fold and 5-fold, respectively, in the kidneys, and 11-fold, 11-fold and 3-fold, respectively, in the livers. None of these manoeuvres caused significant changes of VEGF mRNA in lung, heart or kidneys. Only in the livers did hypoxia lead to a significant (50%) increase of VEGF mRNA. These findings suggest that, in contrast to the in vitro situation, the expression of the VEGF gene in normal rat tissues is rather insensitive to hypoxia. In consequence, the in vivo regulation of the VEGF and the EPO genes appear to differ substantially, suggesting that the regulation of the VEGF and EPO genes may not follow the same essential mechanisms in vivo.
    [Characterisation of the protective role of erythropoetin in a murine model of acute lung injury]. Yegen C H,Haine L,Marchant D,Boncoeur E,Voituron N Revue des maladies respiratoires In addition to its role in erythropoiesis, erythropoietin (Epo) plays a role in tissue protection, which includes cardioprotective, nephroprotective and neuroprotective effects. The presence of Epo and its receptor (Epo-R) in pulmonary tissue also suggests a cytoprotective effect of Epo in the lung. Our project aims to document this role in a murine model under-expressing Epo. The obtained results will lead to a better understanding of the cytoprotective effects of Epo and will also give an appreciation of its beneficial effects in cases of lung injury. 10.1016/j.rmr.2020.02.005
    Erythropoietin is a multifunctional tissue-protective cytokine. Erbayraktar Serhat,Yilmaz Osman,Gökmen Necati,Brines Michael Current hematology reports Erythropoietin (EPO) was originally identified as a hormone produced by the adult kidney to facilitate optimum delivery of oxygen to tissue beds by adjustment of the circulating erythrocyte mass. The cloning of the EPO gene, subsequent production of recombinant protein, and successful introduction into clinical practice for the treatment of the anemia of renal failure is a triumph of biotechnology. However, molecular biologic studies have established that EPO is a member of the cytokine superfamily, with significant homology to mediators of growth and inflammation. Therefore, it is not surprising that additional biologic functions for this protein have been identified. Results from studies have shown that EPO and its receptor are widely expressed in embryonic and adult tissues, including the central nervous system, gut, kidney, muscle (eg, smooth, skeletal, and heart), uterus, retina, pancreas, gonads, and lung. We review the evidence that EPO and its receptor function as a paracrine/autocrine system to mediate the protection of tissues subjected to metabolic stress.
    Erythropoetin as a novel agent with pleiotropic effects against acute lung injury. Kakavas Sotirios,Demestiha Theano,Vasileiou Panagiotis,Xanthos Theodoros European journal of clinical pharmacology Current pharmacotherapy for acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) is not optimal, and the biological and physiological complexity of these severe lung injury syndromes requires consideration of combined-agent treatments or agents with pleiotropic action. In this regard, exogenous erythropoietin (EPO) represents a possible candidate since a number of preclinical studies have revealed beneficial effects of EPO administration in various experimental models of ALI. Taken together, this treatment strategy is not a single mediator approach, but it rather provides protection by modulating multiple levels of early signaling pathways involved in apoptosis, inflammation, and peroxidation, potentially restoring overall homeostasis. Furthermore, EPO appears to confer vascular protection by promoting angiogenesis. However, only preliminary studies exist and more experimental and clinical studies are necessary to clarify the efficacy and potentially cytoprotective mechanisms of EPO action. In addition to the attempts to optimize the dose and timing of EPO administration, it would be of great value to minimize any potential toxicity, which is essential for EPO to fulfill its role as a potential candidate for the treatment of ALI in routine clinical practice. The present article reviews recent advances that have elucidated biological and biochemical activities of EPO that may be potentially applicable for ALI/ARDS management. 10.1007/s00228-010-0938-7
    PDGF-BB modulates hematopoiesis and tumor angiogenesis by inducing erythropoietin production in stromal cells. Xue Yuan,Lim Sharon,Yang Yunlong,Wang Zongwei,Jensen Lasse Dahl Ejby,Hedlund Eva-Maria,Andersson Patrik,Sasahara Masakiyo,Larsson Ola,Galter Dagmar,Cao Renhai,Hosaka Kayoko,Cao Yihai Nature medicine The platelet-derived growth factor (PDGF) signaling system contributes to tumor angiogenesis and vascular remodeling. Here we show in mouse tumor models that PDGF-BB induces erythropoietin (EPO) mRNA and protein expression by targeting stromal and perivascular cells that express PDGF receptor-β (PDGFR-β). Tumor-derived PDGF-BB promoted tumor growth, angiogenesis and extramedullary hematopoiesis at least in part through modulation of EPO expression. Moreover, adenoviral delivery of PDGF-BB to tumor-free mice increased both EPO production and erythropoiesis, as well as protecting from irradiation-induced anemia. At the molecular level, we show that the PDGF-BB-PDGFR-bβ signaling system activates the EPO promoter, acting in part through transcriptional regulation by the transcription factor Atf3, possibly through its association with two additional transcription factors, c-Jun and Sp1. Our findings suggest that PDGF-BB-induced EPO promotes tumor growth through two mechanisms: first, paracrine stimulation of tumor angiogenesis by direct induction of endothelial cell proliferation, migration, sprouting and tube formation, and second, endocrine stimulation of extramedullary hematopoiesis leading to increased oxygen perfusion and protection against tumor-associated anemia. 10.1038/nm.2575
    Importance of erythropoietin in brain protection after cardiac surgery: a pilot study. Lakic Nikola,Surlan Katarina,Jerin Ales,Meglic Bernard,Curk Nina,Bunc Matjaz The heart surgery forum BACKGROUND:Neurologic complications after cardiac operations present an important medical problem, as well as a financial burden. They increase the morbidity and hospital stays of patients who have otherwise undergone successful heart operations. The current protocols for perioperative brain protection against ischemic events are not optimal. Because of its different pleiotropic mechanisms of action, recombinant human erythropoietin might provide neuroprotection. METHODS:In this study, we included 20 patients who were older than 18 years and required surgical revascularization of the heart with the use of the heart-lung machine. Ten patients received 3 consecutive intravenous doses (24,000 IU) of recombinant human erythropoietin (rHuEpo). Neurologic and magnetic resonance imaging (MRI) examinations were done before and in the first 5 days after surgery. RESULTS:The erythropoietin-treated and control groups were comparable with respect to study protocol outcomes: number of coronary artery bypass grafts (3.3 and 3.2 grafts/patient, respectively), operative time (4.12 and 4.6 hours), and transfusion volume per patient (708 and 674 mL). The groups were also comparable with respect to blood pressure values at all stages of the operation. MRI scans revealed that 4 of 10 patients from the control group had fresh ischemic brain lesions after open heart surgery. None of the patients in the erythropoietin-treated group had fresh ischemic brain lesions. CONCLUSION:Although the number of patients was small, the results regarding brain protection with rHuEpo are encouraging. rHuEpo is a promising neuroprotective agent. 10.1532/HSF98.20091150
    Prophylactic erythropoietin exacerbates ventilation-induced lung inflammation and injury in preterm lambs. Polglase Graeme R,Barton Samantha K,Melville Jacqueline M,Zahra Valerie,Wallace Megan J,Siew Melissa L,Tolcos Mary,Moss Timothy J M The Journal of physiology Ventilation-induced lung injury (VILI) of preterm neonates probably contributes to the pathogenesis of bronchopulmonary dysplasia (BPD). Erythropoietin (EPO) has been suggested as a therapy for BPD. The aim of this study was to determine whether prophylactic administration of EPO reduces VILI in preterm newborn lambs. Lambs at 126 days of gestation (term is 147 days) were delivered and ventilated with a high tidal volume strategy for 15 min to cause lung injury, then received gentle ventilation until 2 h of age. Lambs were randomized to receive intravenous EPO (5000 IU kg(-1): Vent+EPO; n = 6) or phosphate-buffered saline (Vent; n = 7) soon after birth: unventilated controls (UVC; n = 8) did not receive ventilation or any treatment. Physiological parameters were recorded throughout the experimental procedure. Samples of lung were collected for histological and molecular assessment of inflammation and injury. Samples of liver were collected to assess the systemic acute phase response. Vent+EPO lambs received higher F IO 2, P aO 2 and oxygenation during the first 10 min than Vent lambs. There were no differences in physiological indices beyond this time. Total lung injury score, airway wall thickness, inflammation and haemorrhage were higher in Vent+EPO lambs than in Vent lambs. Lung inflammation and early markers of lung and systemic injury were elevated in ventilated lambs relative to unventilated lambs; EPO administration further increased lung inflammation and markers of lung and systemic injury. Prophylactic EPO exacerbates VILI, which may increase the incidence and severity of long-term respiratory disease. More studies are required before EPO can be used for lung protection in preterm infants. 10.1113/jphysiol.2013.270348
    Erythropoietin attenuates renal and pulmonary injury in polymicrobial induced-sepsis through EPO-R, VEGF and VEGF-R2 modulation. Heitrich Mauro,García Daiana Maria de Los Ángeles,Stoyanoff Tania Romina,Rodríguez Juan Pablo,Todaro Juan Santiago,Aguirre María Victoria Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie Sepsis remains the most important cause of acute kidney injury (AKI) and acute lung injury (ALI) in critically ill patients. The cecal ligation and puncture (CLP) model in experimental mice reproduces most of the clinical features of sepsis. Erythropoietin (EPO) is a well-known cytoprotective multifunctional hormone, which exerts anti-inflammatory, anti-oxidant, anti-apoptotic and pro-angiogenic effects in several tissues. The aim of this study was to evaluate the underlying mechanisms of EPO protection through the expression of the EPO/EPO receptor (EPO-R) and VEGF/VEF-R2 systems in kidneys and lungs of mice undergoing CLP-induced sepsis. Male inbred Balb/c mice were divided in three experimental groups: Sham, CLP, and CLP+EPO (3000IU/kg sc). Assessment of renal functional parameters, survival, histological examination, immunohistochemistry and/or Western blottings of EPO-R, VEGF and VEGF-R2 were performed at 18h post-surgery. Mice demonstrated AKI by elevation of serum creatinine and renal histologic damage. EPO treatment attenuates renal dysfunction and ameliorates kidney histopathologic changes. Additionally, EPO administration attenuates deleterious septic damage in renal cortex through the overexpression of EPO-R in tubular interstitial cells and the overexpression of the pair VEGF/VEGF-R2. Similarly CLP- induced ALI, as evidenced by parenchymal lung histopathologic alterations, was ameliorated through pulmonary EPO-R, VEGF and VEGF-R2 over expression suggesting and improvement in endothelial survival and functionality. This study demonstrates that EPO exerts protective effects in kidneys and lungs in mice with CLP-induced sepsis through the expression of EPO-R and the regulation of the VEGF/VEGF-R2 pair. 10.1016/j.biopha.2016.05.045
    Genipin attenuates hyperoxia-induced lung injury and pulmonary hypertension via targeting glycogen synthase kinase-3 β in neonatal rats. Li Jing,Shi Jipeng,Li Peiling,Guo Xixia,Wang Tuanjie,Liu Aijuan Nutrition (Burbank, Los Angeles County, Calif.) OBJECTIVES:Bronchopulmonary dysplasia is the most common chronic lung disease of infancy and is associated with pulmonary hypertension (PH). Inhibition of glycogen synthase kinase (GSK)-3 β has been shown to attenuate lung injury and PH in hyperoxia-exposed newborn rats. Genipin has been widely used for the treatment of inflammatory diseases. The aim of this study was to show that genipin decreased the expression of GSK-3 β in lung tissues of hyperoxia-exposed rat pups. METHODS:We established models of hyperoxia-exposed rat pups, evaluated lung injury and pulmonary hypertension and detected the mRNA and protein expression of key molecules. RESULTS:Hyperoxia resulted in the reduction of survival rate and histologic injury of lung tissues; an increase of the messenger RNA (mRNA) expression of transforming growth factor-β1, extracellular matrix proteins collagen-I and fibronectin, and α-smooth muscle actin; an increase of right ventricular (RV) systolic pressure and the weight ratio of RV to left ventriclar (LV) plus septum (S) (RV/LV + S) were inhibited by genipin. Genipin also decreased the levels of tumor necrosis factor-α, interleukin-1 β, and interleukin-6 in both bronchoalveolar lavage fluid and lung tissues after hyperoxia exposure. In addition, genipin inhibited p65 nuclear factor-κB nuclear translocation and matrix metalloproteinase-2 and -9 expression. Moreover, hyperoxia resulted in an increase of methane dicarboxylic aldehyde content and a decrease of superoxide dismutase activity, catalytic subunit of glutamate-cysteine ligase, modified subunit of glutamate-cysteine ligase, and nuclear factor erythroid 2-related factor 2 expression were inhibited by genipin. All these effects induced by genipin were blocked by upregulation of GSK-3 β. Genipin downregulated GSK-3 β expression, decreased nuclear factor-κB translocation, increased nuclear factor erythroid 2-related factor 2 expression, attenuated inflammation and oxidative stress, leading to amelioration of lung injury and PH in hyperoxia-exposed rat pups. CONCLUSION:Overall, genipin may provide a novel therapeutic option for preventing and treating infants with bronchopulmonary dysplasia. 10.1016/j.nut.2018.05.017
    The effects of bosentan on hyperoxia-induced lung injury in neonatal rats. Özdemir Özmert Ma,Taban Özgün,Enli Yaşar,Bir Ferda,Şahin Barbaros,Ergin Hacer Pediatrics international : official journal of the Japan Pediatric Society BACKGROUND:Bronchopulmonary dysplasia (BPD) remains an important cause of morbidity and mortality in premature infants. There is currently no proven effective treatment modality for BPD, and inflammation and oxidative injury play an important role in the pathogenesis of this disease. This study investigated the histopathological and biochemical effects of bosentan, which is a non-specific endothelin receptor antagonist with known antioxidant and anti-inflammatory properties, on hyperoxia-induced lung injury (HILI) in neonatal rats. METHODS:The experiment was performed on newborn rats from the 3rd to the 13th postnatal day. The rats were randomly divided into six groups: Group 1 (air-exposed + saline, n = 6); Group 2 (HILI, n = 8); Group 3 (air-exposed + bosentan, n = 7); Group 4 (HILI + saline, n = 7); Group 5 (HILI + early bosentan-treated group, n = 6), and Group 6 (HILI + late bosentan-treated group, n = 7). Bosentan was administered (30 mg/kg/day) intraperitoneally. The histopathological effects of bosentan on lung tissue were assessed by their alveolar surface area, fibrosis, and smooth muscle actin (SMA) scores, and the biochemical effects on lung tissue were assessed by interleukin-1 beta (IL-1β), IL-6, IL-10, and tumor necrosis factor-alpha (TNF-α). RESULTS:The alveolar surface area and fibrosis scores were found to be significantly higher in HILI groups compared with Group 1 (P < 0.01). The SMA scores in HILI groups were also significantly higher than Group 1 (P < 0.01). Bosentan treatment, especially late therapy, reduced all of these histopathological scores and the levels of IL-6 and TNF-α in the hyperoxia groups (P < 0.01). CONCLUSION:This experimental study showed that bosentan had a protective effect on hyperoxic lung injury through its anti-inflammatory properties. 10.1111/ped.14013
    Protective effect of agmatine against hyperoxia-induced acute lung injury via regulating lncRNA gadd7. Liu Guoyue,Mei Hong,Chen Miao,Qin Song,Li Kang,Zhang Wei,Chen Tao Biochemical and biophysical research communications Hyperoxia-induced acute lung injury (HALI) is a kind of iatrogenic pulmonary dysfunction caused by the prolonged exposure to high concentrations of oxygen, which is commonly seen in the treatment of refractory hypoxemia. Agmatine (AGM), a biogenic amine metabolite of l-arginine, induces a variety of physiological and pharmacological effects in the body. In this study, we investigated the protective effect of AGM on hyperoxia-induced lung injury and explored the underlying mechanism. A series of methods were used including flow cytometry, tunnel assay, dual-luciferase reporter assay, qRT-PCR and Western blotting. The results indicate that AGM can protect hyperoxia-induced lung injury. Further studies suggest that AGM decreased the upregulated expression of lncRNA gadd7 caused by hyperoxia and due to the presence of the competitive binding of lncRNA gadd7 and MFN1 to miR-125a, AGM indirectly decreased MFN1 protein expression to inhibit the cells apoptosis. In conclusion, AGM protects hyperoxia-induced lung injury by decreasing the expression of lncRNA gadd7 to regulate MFN1 expression. 10.1016/j.bbrc.2019.04.164
    Maternal Tn Immunization Attenuates Hyperoxia-Induced Lung Injury in Neonatal Rats Through Suppression of Oxidative Stress and Inflammation. Chen Chung-Ming,Hwang Jaulang,Chou Hsiu-Chu Frontiers in immunology Hyperoxia therapy is often required to treat newborns with respiratory disorders. Prolonged hyperoxia exposure increases oxidative stress and arrests alveolar development in newborn rats. Tn antigen is N-acetylgalactosamine residue that is one of the most remarkable tumor-associated carbohydrate antigens. Tn immunization increases the serum anti-Tn antibody titers and attenuates hyperoxia-induced lung injury in adult mice. We hypothesized that maternal Tn immunizations would attenuate hyperoxia-induced lung injury through the suppression of oxidative stress in neonatal rats. Female Sprague-Dawley rats (6 weeks old) were intraperitoneally immunized five times with Tn (50 μg/dose) or carrier protein at biweekly intervals on 8, 6, 4, 2, and 0 weeks before the day of delivery. The pups were reared in room air (RA) or 2 weeks of 85% O, creating the four study groups: carrier protein + RA, Tn vaccine + RA, carrier protein + O, and Tn vaccine + O. The lungs were excised for oxidative stress, cytokine, vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) expression, and histological analysis on postnatal day 14. Blood was withdrawn from dams and rat pups to check anti-Tn antibody using western blot. We observed that neonatal hyperoxia exposure reduced the body weight, increased 8-hydroxy-2-deoxyguanosine (8-OHdG) expression and lung cytokine (interleukin-4), increased mean linear intercept (MLI) values, and decreased vascular density and VEGF and PDGF-B expressions. By contrast, Tn immunization increased maternal and neonatal serum anti-Tn antibody titers on postnatal day 14, reduced MLI, and increased vascular density and VEGF and PDGF-B expressions to normoxic levels. Furthermore, the alleviation of lung injury was accompanied by a reduction in lung cytokine and 8-OHdG expression. Therefore, we propose that maternal Tn immunization attenuates hyperoxia-induced lung injury in neonatal rats through the suppression of oxidative stress and inflammation. 10.3389/fimmu.2019.00681
    Lipoxin A4 reduces hyperoxia-induced lung injury in neonatal rats through PINK1 signaling pathway. Wu Qiuping,Chong Lei,Shao Youyou,Chen Shangqin,Li Changchong International immunopharmacology Bronchopulmonary dysplasia (BPD) is a common chronic lung disease in premature infants and is mainly caused by hyperoxia exposure and mechanical ventilation. Alveolar simplification, pulmonary vascular abnormalities and pulmonary inflammation are the main pathological changes in hyperoxic lung injury animals. Lipoxin A4 (LXA4) is an important endogenous lipid that can mediate the regression of inflammation and plays a role in acute lung injury and asthma. The purpose of this study was to evaluate the effects of LXA4 on inflammation and lung function in neonatal rats with hyperoxic lung injury and to explore the mechanism of the PINK1 pathway. After 85% oxygen exposure in newborn rats for 7 days, the BPD model was established. We found that LXA4 could significantly reduce cell and protein infiltration and oxidative stress in rat lungs, improve pulmonary function and alveolar simplification, and promote weight gain. LXA4 inhibited the expression of TNF-α, MCP-1 and IL-1β in serum and BALF from hyperoxic rats. Moreover, we found that LXA4 could reduce the expression of the PINK1 gene and down-regulate the expression of PINK1, Parkin, BNIP3L/Nix and the autophagic protein LC3B.These protective effects of LXA4 could be partially reversed by addition of BOC-2.Thus, we concluded that LXA4 can alleviate the airway inflammatory response, reduce the severity of lung injury and improve lung function in a hyperoxic rat model of BPD partly through the PINK1 signaling pathway. 10.1016/j.intimp.2019.05.046
    Roles of the mammalian target of rapamycin (mTOR) signaling pathway in the repair of hyperoxia-induced acute lung injury. Wang Shao-Hua,Li Long-Hui,Zou Dong-Mei,Zheng Xue-Mei,Deng Jian Advances in clinical and experimental medicine : official organ Wroclaw Medical University BACKGROUND:Rapamycin inhibits the mammalian target of rapamycin (mTOR) activity and has been proven effective for the treatment of lung injury. OBJECTIVES:The objective of this study was to investigate the roles of the mTOR pathway and its inhibitor rapamycin in the repair of hyperoxia-induced acute lung injury (ALI). MATERIAL AND METHODS:Firstly, premature rat lung fibroblast L929 cells were cultured under different oxygen concentrations (40%, 60%, and 90%). At day 3, 7 and 14 after exposure, MTT assay and flow cytometry were used to evaluate the effect of oxygen stress on cell viability and apoptosis of L929 cells, respectively. Secondly, microscopy, MTT assay and flow cytometry was used to investigate the effect of 10 nM rapamycin on 90% O2 exposed L929 cells. We also used small interfering RNAs (siRNAs) to abrogate the expression of mTOR in 90% O2 exposed L929 cells, and then evaluated the apoptosis and cell viability using flow cytometry and the MTT assay, respectively. In addition, western blot was used to detect the protein expression of Bcl-2, p53, TGF-β and connective tissue growth factor (CTGF). A hyperoxia-induced lung injury model was established in Sprague Dawley (SD) rats in order to evaluate the histopathological changes in lung tissues and expression of the mTOR pathway and fibrosis related factors. RESULTS:Exposure to 40%, 60% or 90% oxygen all significantly inhibited the growth of L929 cells. Application of 10 nM rapamycin was found to effectively promote apoptosis of 90% O2 exposed L929 cells. In addition, mTOR siRNA promoted the apoptosis and inhibited the growth of L929 cells. Rapamycin inhibited the activation of the mTOR signaling pathway, down-regulated the expression of downstream proteins p70S6K and 4EBP1, reduced the collagen deposition and the production of fibrosis-inducing factors, including TGF-β and CTGF in hyperoxia-induced lung injury rats. CONCLUSIONS:Rapamycin may be useful for the treatment of hyperoxia-induced acute lung injury (ALI) by inhibiting the activation of mTOR signaling pathway. 10.17219/acem/76170
    Effects of nebulized N--acetylcystein on the expression of HMGB1 and RAGE in rats with hyperoxia--induced lung injury. Qiao Junying,Chen Lixia,Huang Xianjie,Guo Feifei Journal of cellular physiology OBJECTIVE:To investigate the role of high mobility group box 1 (HMGB1) and receptor for advanced glycation end product (RAGE) in the lungs of hyperoxia-induced rats and the effect of N--acetlycystein (NAC). METHODS:A model of hyperoxic lung injury was established, rats in the NAC intervention, and control, hyperoxia group were given nebulized NAC aerosol, nebulized same volume of saline once a day for 7 consecutive days, respectively. Wet/dry ( W/ D) ratio of the lungs was determined to evaluate the edema of the lung tissues. Conventional hematoxylin-eosin (HE) staining was used to observe the pathological changes of lung tissues. Immunohistochemical staining was used to investigate the expression of HMGB1 and RAGE in the lung tissues. Quantitative reverse-transcription polymerase chain reaction and western blot analysis were used to measured the changes in the messenger RNA (mRNA) and protein expression of HMGB1 and RAGE, respectively. RESULTS:Weight gain of the rats in the hyperoxia group was significantly slower than that in the control group and intervention group (p < 0.05). HE staining results showed lung tissues in the hyperoxia group were severely damaged compared with control group. W/D ratio in hyperoxia group was significantly higher than that in control group and intervention group (p < 0.05). Protein and mRNA expression of HMGB1 and RAGE in the hyperoxia group were significantly higher than control group and intervention group (p < 0.05). CONCLUSION:HMGB1 and RAGE were involved in the pathogenesis of hyperoxia-induced lung injury, inhalation of NAC might alleviate hyperoxia-induced lung injury by regulating the expression of HMGB1 and RAGE. 10.1002/jcp.27724