losartan-potassium and Acute-Lung-Injury

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.

Topics: Acute Lung Injury; Animals; Cytoprotection; Disease Models, Animal; Erythropoietin; Hematopoiesis; Humans; Kidney; Lung; Mice

The novel coronavirus 2019-nCoV (SARS-CoV-2) infection that emerged in China in December 2019 has rapidly spread to become a global pandemic. This article summarizes the potential benefits of erythropoietin (EPO) in alleviating SARS-CoV-2 pathogenesis which is now called COVID-19. As with other coronavirus infection, the lethality of COVID-19 is associated with respiratory dysfunction due to overexpression of proinflammatory cytokines induced by the host immune responses. The resulting cytokine storm leads to the development of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Erythropoietin, well known for its role in the regulation of erythropoiesis, may have protective effects against ALI/ARDS induced by viral and other pathogens. EPO exerts antiapoptotic and cytoprotective properties under various pathological conditions. With a high safety profile, EPO promotes the production of endothelial progenitor cells and reduce inflammatory processes through inhibition of the nuclear factor-κB (NF-κB) and JAK-STAT3 signaling pathways. Thus, it may be considered as a safe drug candidate for COVID-19 patients if given at the early stage of the disease. The potential effects of erythropoietin on different aspects of ALI/ARDS associated with SARS-CoV-2 infection are reviewed.

Topics: Acute Lung Injury; Anti-Inflammatory Agents; COVID-19; COVID-19 Drug Treatment; Cytokine Release Syndrome; Erythropoietin; Humans; Respiratory Distress Syndrome; SARS-CoV-2

This article describes the incidence and etiology of anemia in critically ill children. In addition, the article details the pathophysiology and clinical ramifications of anemia in this population. The use of transfused packed red blood cells as a therapy for anemia in critically ill patients is also discussed, including the indications for and complications associated with this practice as well as potential reasons for these complications. Finally, the article lists some therapeutic practices that may lessen the risks associated with transfusion, and briefly discusses the use of blood substitutes.

Topics: Acute Lung Injury; Anemia; Blood Substitutes; Blood Transfusion; Child; Child, Preschool; Critical Illness; Erythropoietin; Hemodilution; Humans; Immunomodulation; Infant; Infant, Newborn; Infant, Premature; Iron; Phlebotomy; Risk Factors; Transfusion Reaction; Treatment Outcome

Topics: Acute Lung Injury; Adult; Anemia; Blood Preservation; Blood Specimen Collection; Brain Injuries; Critical Illness; Erythrocyte Transfusion; Erythropoietin; Hemorrhage; Humans; Myocardial Ischemia; Nervous System Diseases; Sepsis; Shock; Stroke; Subarachnoid Hemorrhage

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.

Topics: Acute Lung Injury; Erythropoietin; Humans; Recombinant Proteins; Respiratory Distress Syndrome

Bone marrow suppression after intensive chemotherapies in patients with myeloid leukemia is severe, resulting in the reduction of the number of white blood cells, red blood cells, and platelets. Supportive therapies are indispensable for the management of these leukemia patients. The improvement of blood cell transfusion can decrease side effects of chemotherapies and establish the safety. But we still have notable side effects of transfusion such as TRALI (transfusion-related acute lung injury), platelet immunologic refractory state, and so on. Cytokine therapy especially with G-CSF (granulocyte colony-stimulating factor) administration, changed the treatment of myeloid leukemia. G-CSF can shorten the duration of neutropenia and decrease the risk of infection. Recently the effects of Epo (erythropoietin) on chemotherapy-induced anemia have been demonstrated. We discuss here the indications of blood cell transfusion and cytokine therapies in the treatment for myeloid leukemia.

Topics: Acute Lung Injury; Antineoplastic Agents; Blood Component Transfusion; Blood Transfusion; Erythropoietin; Graft vs Host Disease; Granulocyte Colony-Stimulating Factor; Humans; Leukemia, Myeloid; Practice Guidelines as Topic; Transfusion Reaction

Severe pneumonia is a kind of disease that develops from lung inflammation, and new drugs are still required to treat the same. Erythropoietin (EPO) is widely used to treat anemia in patients. However, there are fewer studies on the role of EPO in neutrophil extracellular trappings (NETs) and pneumonia, and the mechanism is unclear.. To investigate the possible effects of EPO on the formation of NETs and progression of pneumonia.. Mice pneumonia model was induced by tracheal lipopolysaccharide (LPS) administration. Hematoxylin and eosin (H&E) staining and automatic blood cell analysis were performed in this model to confirm the effects of EPO on lung injury. Flow cytometry, enzyme-linked immunosorbent serological assay, and immunostaining assay were conducted to detect the effects of EPO on the inflammation as well as formation of NETs in mice. Immunoblot was further conducted to confirm the mechanism.. EPO alleviated LPS-induced lung injury. EPO reduced the release of inflammatory factors induced by LPS. In addition, EPO inhibited the formation of NETs. Mechanically, EPO inhibited tumor necrosis factor (TNF) receptor associated factor 2 (TRAF2)/nuclear factor kappa-B (NF-κB) activity in mouse models, and therefore suppressed the progression of pneumonia.. EPO inhibited formation of NETs to ameliorate lung injury in a pneumonia model, and could serve as a drug of pneumonia.

Topics: Acute Lung Injury; Animals; Erythropoietin; Extracellular Traps; Humans; Lipopolysaccharides; Mice; Pneumonia

Topics: Acute Lung Injury; Animals; Cell Line; Erythropoietin; Humans; p38 Mitogen-Activated Protein Kinases; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction

Acute lung injury (ALI) is a clinical problem with poor prognosis and high mortality. The purpose of this study was to explore the effects of helix B position peptide (HBSP) on ALI and its mechanism.. C57/BL6 male mice were used to construct ALI models by LPS tracheal injection and detect the effect of HBSP on mouse ALI by subcutaneously injecting HBSP. In addition, normal human lung epithelial cell line (BEAS-2B) were cultured and stimulated with HBSP. Then, the effects of HBSP on oxidative stress and endoplasmic reticulum stress (ERS) in BEAS-2B cells were examined. Finally, the effect of HBSP on the Nrf2/HO-1 signaling pathway was examined, and the mechanism of action of HBSP was verified using the Nrf2/HO-1 signaling pathway inhibitor ML385.. In vitro, HBSP increased the expression of SOD1/2 and decreased the expression of ERS-related molecules such as CHOP, GRP-78, and caspase-12, indicating that HBSP effectively reduces the level of oxidative stress and ERS in BEAS-2B cells. In addition, HBSP also increased the activity of the Nrf2/HO-1 signaling pathway and ML385 reduced the protective effect of HBSP on BEAS-2B cells. In vivo, HBSP significantly reduced LPS-induced mouse ALI. W/D and inflammatory factors in the BALF of the mouse lung were significantly reduced and the level of oxidative stress was also reduced.. HBSP plays an important role in relieving ALI by activating Nrf2/HO-1 signaling pathway, which reduces the level of inflammation in lung tissue and oxidative stress and ERS in lung epithelial cells.

Topics: Acute Lung Injury; Animals; Cells, Cultured; Disease Models, Animal; Endoplasmic Reticulum Stress; Erythropoietin; Heme Oxygenase-1; Humans; Injections, Subcutaneous; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; NF-E2-Related Factor 2; Oxidative Stress; Peptide Fragments; Signal Transduction

Acute lung injury (ALI) exhibits high clinical morbidity and mortality rates. Our previous study has indicated that the novel proteolysis-resistant cyclic helix B peptide (CHBP) exerts an anti-inflammatory effect in mice with AKI. In the present study, we evaluated the effect of CHBP in an in vivo sepsis-induced ALI model and in vitro using lipopolysaccharide (LPS) and ATP stimulated bone marrow-derived macrophages (BMDMs). For in vivo experiments, mice were randomly divided into three groups: 1) sham; 2) LPS; and 3) LPS + CHBP (n = 6). All relevant data were collected after 18 h. Following CHBP treatment, the lung function of the mice was significantly improved compared to the LPS group. CHBP administration inhibited interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α production at both the protein and mRNA levels. Additionally, following CHBP treatment, the population of pulmonary macrophages decreased. Simultaneously, the proportion of caspase-1-activated alveolar macrophages was also decreased after CHBP treatment. The protein levels of NLRP3 and cleaved caspase-1 were attenuated in the lung tissue following CHBP treatment. In in vitro experiments, CHBP treatment decreased NLRP3 inflammasome expression and downstream IL-1β secretion, consistent with the in vivo results. In addition, CHBP reversed nuclear factor (NF)-κB and I-κB phosphorylation with a significant dose-dependent effect. Therefore, these findings suggest the potential of CHBP as a therapeutic agent in sepsis-induced ALI owing to inhibition of the NLRP3 inflammasome via the NF-κB pathway in macrophages.

Topics: Acute Lung Injury; Animals; Caspase 1; Cells, Cultured; Cytokines; Down-Regulation; Erythropoietin; I-kappa B Proteins; Inflammasomes; Lipopolysaccharides; Lung; Macrophages; Macrophages, Alveolar; Male; Mice, Inbred C57BL; NF-kappa B p50 Subunit; NLR Family, Pyrin Domain-Containing 3 Protein; Peptide Fragments; Sepsis; Signal Transduction

Kidney ischemia and reperfusion injury could cause microvascular barrier dysfunction, lung inflammatory cascades activation, and programmed cell death of pulmonary endothelium, leading to acute lung injury. Our study aimed at determining whether erythropoietin (EPO) can ameliorate lung dysfunction following renal ischemia and reperfusion (IR) injury and explored the underlying mechanisms.. In vivo, C57BL/6 mice received EPO (6000 U/kg) before right renal vascular pedicles clamping for 30 minutes, followed by 24 hours of reperfusion. The lung histopathologic changes and inflammatory cytokines expression were assessed. In vitro, cultured human umbilical vein endothelial cells were treated with EPO, and apoptosis rate, proliferation capacity, and phosphorylation status of the Janus kinase-signal transducer and activator of transcription 3 (Jak-STAT3) pathway were measured respectively in the presence or absence of lipopolysaccharide stimulation.. In vivo, EPO remarkably attenuated pulmonary interstitial and alveolar epithelial edema caused by renal IR injury. In vitro, the proliferation capacity of human umbilical vein endothelial cells was significantly increased under EPO stimulation, which correlated with changes in Jak-STAT3 signaling.. Our data indicated that EPO is able to ameliorate acute lung tissue damage induced by renal IR, and at least in part, via the Jak-STAT3 pathway.

Topics: Acute Lung Injury; Animals; Cell Line; Cell Proliferation; Endothelium, Vascular; Erythropoietin; Humans; Janus Kinases; Kidney; Kidney Diseases; Male; Mice; Mice, Inbred C57BL; Reperfusion Injury; Signal Transduction; STAT3 Transcription Factor

The aim of this study was to explore the effects of erythropoietin (EPO) in acute lung injuries in rats with sepsis. 127 male SD rats were divided into 3 groups (n=8): group Sham, group ALI (sepsis-caused lung injury), group EPO (EPO intervention). The blood gas analysis, C-reactive protein level (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-10 were detected and compared. The water content fraction and myeloperoxidase (MPO) activities, apoptosis, and expression level of nuclear factor -κB (NF-κB p65) in lung tissues were also detected. Compared to group Sham, the oxygenation index of group ALI was decreased (140.66±12.82 vs. 194.7±16.36), CRP (peak value: 2.31±0.33 mg/L vs. 1.00±0.16 mg/L), IL-10 (peak value: 711.26±84.97 ng/L vs. 51.21±11.45 ng/L), TNF-a (63.69±6.85 ng/L vs. 12.92±0.91 ng/L), and IL-6 (peak value: 1768.93±195.11 ng/L vs. 68.71±11.48 ng/L) increased (

Topics: Acute Lung Injury; Animals; Apoptosis; Blood Gas Analysis; Cecum; Erythropoietin; Inflammation Mediators; Ligation; Lung; Peroxidase; Protective Agents; Punctures; Rats, Sprague-Dawley; Sepsis; Transcription Factor RelA; Water

Traumatic brain injury (TBI) can be complicated by TBI-triggered acute lung injury (ALI), in which inflammation plays a central role. It has been reported that an Erythropoietin-derived peptide (pHBSP) was able to ameliorate TBI; however, its function in TBI-caused ALI has not been reported yet.. In this study, we studied the effect of pHBSP on TBI-caused ALI by using a weight-drop induced TBI model. At 8 h and 24 h post-TBI, pulmonary edema (PE) and bronchoalveolar lavage fluid (BALF) proteins were measured, and haematoxylin and eosin (H&E) staining of lung sections was carried out. At 24 h following TBI, the lungs were harvested for immunofluorescence staining and qRT-PCR analysis.. At 8 h and 24 h post-TBI, pHBSP treatment significantly decreased wet/dry ratios, decreased total BALF protein, and attenuated the histological signs of pulmonary injury. At 24 h post-TBI, pHBSP treatment decreased the accumulation of CD68+ macrophages in the lung and reduced the mRNA levels of TNF-α, IL-6, IL-1β and iNOS in the lung.. We identified the protective role that pHBSP played in TBI-caused ALI, suggesting that pHBSP is a potent candidate for systemic therapy in TBI patients.

Topics: Acute Lung Injury; Animals; Brain Injuries, Traumatic; Cytokines; Disease Models, Animal; Erythropoietin; Lung; Macrophages; Male; Nitric Oxide Synthase Type II; Peptides; Rats; Rats, Inbred Lew; Time Factors

Seawater drowning-induced acute lung injury (ALI) is a serious clinical condition characterized by increased alveolar-capillary permeability, excessive inflammatory responses, and refractory hypoxemia. However, current therapeutic options are largely supportive; thus, it is of great interest to search for alternative agents to treat seawater aspiration-induced ALI. Erythropoietin (EPO) is a multifunctional agent with antiinflammatory, antioxidative, and antiapoptotic properties. However, the effects of EPO on seawater aspiration-induced ALI remain unclear. In the present study, male rats were randomly assigned to the naive group, normal saline group, seawater group, or seawater + EPO group. EPO was administered intraperitoneally at 48 and 24 h before seawater aspiration. Arterial blood gas analysis was performed with a gas analyzer at baseline, 30 min, 1 h, 4 h, and 24 h after seawater aspiration, respectively. Histological scores, computed tomography scan, nuclear factor kappa B p65, inducible nitric oxide synthase, caspase-3, tumor necrosis factor-alpha, interleukin (IL)-1β, IL-6, IL-10, wet-to-dry weight ratio, myeloperoxidase activity, malondialdehyde, and superoxide dismutase in the lung were determined 30 min after seawater aspiration. Our results showed that EPO pretreatment alleviated seawater aspiration-induced ALI, as indicated by increased arterial partial oxygen tension and decreased lung histological scores. Furthermore, EPO pretreatment attenuated seawater aspiration-induced increase in the expressions of pulmonary nuclear factor kappa B p65, inducible nitric oxide synthase, caspase-3, tumor necrosis factor-alpha, IL-1β, myeloperoxidase activity, and malondialdehyde when compared with the seawater group. Collectively, our study suggested that EPO pretreatment attenuates seawater aspiration-induced ALI by down-regulation of pulmonary pro-inflammatory cytokines, oxidative stress, and apoptosis.

Topics: Acute Lung Injury; Animals; Anti-Inflammatory Agents; Antioxidants; Apoptosis; Blood Gas Analysis; Caspase 3; Cytokines; Down-Regulation; Drowning; Erythropoietin; Interleukin-10; Interleukin-1beta; Interleukin-6; Lung; Male; Malondialdehyde; NF-kappa B; Nitric Oxide Synthase Type II; Oxidative Stress; Oxygen; Peroxidase; Rats; Rats, Sprague-Dawley; Seawater; Superoxide Dismutase; Tomography, X-Ray Computed; Tumor Necrosis Factor-alpha

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.

Topics: Acute Kidney Injury; Acute Lung Injury; Animals; Blood Urea Nitrogen; Cecum; Creatinine; Disease Models, Animal; Erythropoietin; Kidney; Ligation; Male; Mice, Inbred BALB C; Punctures; Receptors, Erythropoietin; Sepsis; Survival Analysis; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-2

Acute pancreatitis is a life-threatening necroinflammatory disease that is characterized by systemic inflammatory response syndrome and acute lung injury even in its very first days. Erythropoietin (EPO) is a hormone considered as an antiapoptotic and cytoprotective with observed receptors of anti-inflammatory effect on organs apart from the liver and the kidneys. In this study, the effects of EPO on pulmonary mast cells and on secondary injury caused by acute pancreatitis are investigated.. Twenty one Wistar Albino rats were divided into three groups--sham, control, and EPO groups-with 7 rats per group. Pancreatitis was induced by administering 4.5% sodium taurocholate into the pancreatic duct. A 1000 U/kg/day dosage (three times) of EPO was administered to the EPO group. Blood urea nitrogen (BUN), creatinine, amylase, and troponin I in the serum were studied; and lung, kidney, brain, and heart tissues were examined histopathologically.. There were no histopathological changes in the other organ tissues except for the lung tissue. Compared to the control group, the EPO group showed significantly reduced alveolar hemorrhage, septal neutrophil infiltration, lung wall thickness score, and mast cell count in the lung tissue.. Administration of EPO reduces the mast cell count and lung wall thickness, and it reduces the alveolar hemorrhage and septal infiltration induced by acute pancreatitis.

Topics: Acute Lung Injury; Amylases; Animals; Blood Urea Nitrogen; Brain; Creatinine; Erythropoietin; Heart; Kidney; Lung; Male; Mast Cells; Pancreatitis, Acute Necrotizing; Rats; Rats, Wistar; Taurocholic Acid; Troponin I

Accumulating evidences have indicted the participation and repairing effects of endothelial progenitor cells (EPCs) on acute lung injury (ALI). Researchers have also revealed that erythropoietin (EPO) may exert multiple effects on EPCs including proliferative and adhesive properties. The present study was designed to investigate whether EPO can promote the healing efficiency of transplanted EPCs against ALI and the potential mechanism.. Endothelial progenitor cells were derived from bone marrow mononuclear cells of BALB/c mice. In our in vitro studies, we tested the proproliferative and antiapoptotic effects of EPO on cultured EPCs. In our in vivo studies, we induced BALB/c mice ALI model by intratracheal instillation of lipopolysaccharide and treated with/without intravenous injection of enhanced green fluorescent protein-EPCs harvested from enhanced green fluorescent protein-BALB/c mice. Mice that received EPC transplantation either underwent EPO administration or not. The effects of EPO and EPC treatment on promoting pulmonary endothelial repair, decreasing pulmonary capillary permeability, alleviating pulmonary inflammation, improving gas exchange, and promoting pulmonary vessel angiogenesis were tested. The potential mechanisms that mediate EPO functions on EPC were also investigated.. Our studies revealed a significant antiapoptotic property of EPO on cultured EPCs as well as its promotion on EPC proliferation. We also found the severity of ALI was reduced by EPC therapy, and the protective effects of EPCs were highly enhanced when combined with EPO administration. However, all these stimulating effects of EPO on EPCs were consisted with the expression of phospho-Akt and were abrogated by PI3K inhibitors.. Transplanted EPCs directly incorporated into the injured pulmonary vessels and maintain the integrity of pulmonary endothelium. Erythropoietin improved the survival and proliferation of transplanted EPCs and recruited them to the injured sites to exert their repairing functions. PI3K/Akt pathway mediated EPO's functions on EPCs. The combination of EPO and EPC treatment may be a promising cell-based therapy for ALI patients.

Topics: Acute Lung Injury; Animals; Endothelial Progenitor Cells; Erythropoietin; Humans; Mice; Mice, Inbred BALB C; Phosphatidylinositol 3-Kinase; Proto-Oncogene Proteins c-akt; Signal Transduction

In our previous studies, antioxidant transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway has been shown to play an important role in protecting traumatic brain injury (TBI)-induced acute lung injury (ALI). This study was designed to explore whether recombinant human erythropoietin (rhEPO) administration modulates pulmonary Nrf2 signaling pathway in a murine TBI model.. Closed head injury was made by Hall's weight-dropping method. The rhEPO was administered at a dose of 5,000 IU/kg 30 minutes after TBI. Pulmonary capillary permeability, wet or dry weight ratio, apoptosis, Nrf2 and its downstream cytoprotective enzymes including NAD(P)H:quinone oxidoreductase 1, and glutathione S-transferase were investigated at 24 hours after TBI.. We found that treatment with rhEPO markedly ameliorated TBI-induced ALI, as characterized by decreased pulmonary capillary permeability, wet or dry weight ratio, and alveolar cells apoptosis. Administration of rhEPO also significantly upregulated the mRNA expressions and activities of Nrf2 signaling pathway-related agents, including Nrf2, NAD(P)H:quinone oxidoreductase 1, and glutathione S-transferase.. The results of this study suggest that post-TBI rhEPO administration may induce Nrf2-mediated cytoprotective response in the lung, and this may be a mechanism whereby rhEPO reduces TBI-induced ALI.

Topics: Acute Lung Injury; Animals; Apoptosis; Brain Injuries; Capillary Permeability; Erythropoietin; Lung; Male; Mice; NF-E2-Related Factor 2; Signal Transduction

Fas-mediated apoptosis of the alveolar epithelium is important in the pathogenesis of acute respiratory distress syndrome. Erythropoietin (EPO) has cytoprotective properties in other organ systems, and is relatively deficient in critical illness. This study investigates a potential role for EPO in reducing apoptosis in a model of acute lung injury. Apoptosis was induced in human alveolar epithelial (A549) cells or normal human bronchial epithelial (NHBE) cells by Fas activation with CH-11 Fas-crosslinking antibody or by co-culture with polymorphonuclear neutrophils in a transwell system. The effect of recombinant human (rh)EPO on apoptosis was measured by poly(ADP-ribose) polymerase cleavage and cell death detection assay. The specific EPO-EPO receptor (EPOR)-mediated effect was determined using an EPO-blocking antibody or EPOR small interfering RNA. Expression of EPOR was demonstrated in A549, NHBE and normal human alveolar epithelium. Fas- and neutrophil-mediated apoptosis of A549 and NHBE cells was inhibited by rhEPO by a specific EPO-EPOR-mediated mechanism. This anti-apoptotic effect was associated with induction of a pro-apoptotic Bcl-xL/Bax ratio. EPO has cytoprotective properties in respiratory epithelium in an in vitro model, which may indicate a potential therapeutic role in acute lung injury.

Topics: Acute Lung Injury; Analysis of Variance; Apoptosis; Blotting, Western; Cells, Cultured; Coculture Techniques; Epithelial Cells; Erythropoietin; fas Receptor; Flow Cytometry; Humans; Immunohistochemistry; Lipopolysaccharides; Recombinant Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Small Interfering; Transfection; Up-Regulation