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Novel interventional approaches for ALI/ARDS: cell-based gene therapy. Mediators Inflamm 2011; 2011:560194. [PMID: 21785528 PMCID: PMC3139183 DOI: 10.1155/2011/560194] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 05/09/2011] [Accepted: 05/22/2011] [Indexed: 12/21/2022] Open
Abstract
Acute lung injury (ALI) and its more severe
form, acute respiratory distress syndrome (ARDS),
continue to be a major cause of morbidity and
mortality in critically ill patients. The present
therapeutic strategies for ALI/ARDS including
supportive care, pharmacological treatments, and
ventilator support are still controversial. More
scientists are focusing on therapies involving
stem cells, which have self-renewing capabilities
and differentiate into multiple cell lineages,
and, genomics therapy which has the potential to
upregulate expression of anti-inflammatory
mediators. Recently, the combination of cell and
gene therapy which has been demonstrated to
provide additive benefit has opened up a new
chapter in therapeutic strategy and provides a
basis for the development of an innovative
approach for the prevention and treatment of
ALI/ARDS.
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Acute administration of recombinant Angiopoietin-1 ameliorates multiple-organ dysfunction syndrome and improves survival in murine sepsis. Cytokine 2011; 55:251-9. [PMID: 21531574 DOI: 10.1016/j.cyto.2011.04.005] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Revised: 03/22/2011] [Accepted: 04/05/2011] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Endothelial activation leading to vascular barrier breakdown plays an essential role in the pathophysiology of multiple-organ dysfunction syndrome (MODS) in sepsis. Increasing evidence suggests that the function of the vessel-protective factor Angiopoietin-1 (Ang-1), a ligand of the endothelial-specific Tie2 receptor, is inhibited by its antagonist Angiopoietin-2 (Ang-2) during sepsis. In order to reverse the effects of the sepsis-induced suppression of Ang-1 and elevation of Ang-2 we aimed to investigate whether an intravenous injection of recombinant human (rh) Ang-1 protects against MODS in murine sepsis. METHODS Polymicrobiological abdominal sepsis was induced by cecal ligation and puncture (CLP). Mice were treated with either 1 μg of intravenous rhAng-1 or control buffer immediately after CLP induction and every 8h thereafter. Sham-operated animals served as time-matched controls. RESULTS Compared to buffer-treated controls, rhAng-1 treated septic mice showed significant improvements in several hematologic and biochemical indicators of MODS. Moreover, rhAng-1 stabilized endothelial barrier function, as evidenced by inhibition of protein leakage from lung capillaries into the alveolar compartment. Histological analysis revealed that rhAng-1 treatment attenuated leukocyte infiltration in lungs and kidneys of septic mice, probably due to reduced endothelial adhesion molecule expression in rhAng-1 treated mice. Finally, the protective effects of rhAng-1 treatment were reflected by an improved survival time in a lethal CLP model. CONCLUSIONS In a clinically relevant murine sepsis model, intravenous rhAng-1 treatment alone is sufficient to significantly improve a variety of sepsis-associated organ dysfunctions and survival time, most likely by preserving endothelial barrier function. Further studies are needed to pave the road for clinical application of this therapy concept.
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Angiopoietin-1 treatment reduces inflammation but does not prevent ventilator-induced lung injury. PLoS One 2010; 5:e15653. [PMID: 21179479 PMCID: PMC3001877 DOI: 10.1371/journal.pone.0015653] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Accepted: 11/14/2010] [Indexed: 01/28/2023] Open
Abstract
Background Loss of integrity of the epithelial and endothelial barriers is thought to be a prominent feature of ventilator-induced lung injury (VILI). Based on its function in vascular integrity, we hypothesize that the angiopoietin (Ang)-Tie2 system plays a role in the development of VILI. The present study was designed to examine the effects of mechanical ventilation on the Ang-Tie2 system in lung tissue. Moreover, we evaluated whether treatment with Ang-1, a Tie2 receptor agonist, protects against inflammation, vascular leakage and impaired gas exchange induced by mechanical ventilation. Methods Mice were anesthetized, tracheotomized and mechanically ventilated for 5 hours with either an inspiratory pressure of 10 cmH2O (‘low’ tidal volume ∼7.5 ml/kg; LVT) or 18 cmH2O (‘high’ tidal volume ∼15 ml/kg; HVT). At initiation of HVT-ventilation, recombinant human Ang-1 was intravenously administered (1 or 4 µg per animal). Non-ventilated mice served as controls. Results HVT-ventilation influenced the Ang-Tie2 system in lungs of healthy mice since Ang-1, Ang-2 and Tie2 mRNA were decreased. Treatment with Ang-1 increased Akt-phosphorylation indicating Tie2 signaling. Ang-1 treatment reduced infiltration of granulocytes and expression of keratinocyte-derived chemokine (KC), macrophage inflammatory protein (MIP)-2, monocyte chemotactic protein (MCP)-1 and interleukin (IL)-1β caused by HVT-ventilation. Importantly, Ang-1 treatment did not prevent vascular leakage and impaired gas exchange in HVT-ventilated mice despite inhibition of inflammation, vascular endothelial growth factor (VEGF) and Ang-2 expression. Conclusions Ang-1 treatment downregulates pulmonary inflammation, VEGF and Ang-2 expression but does not protect against vascular leakage and impaired gas exchange induced by HVT-ventilation.
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Abstract
Reactive oxygen species (ROS) have been implicated in many intra- and intercellular processes. High levels of ROS are generated as part of the innate immunity in the respiratory burst of phagocytic cells. Low levels of ROS, however, are generated in a highly controlled manner by various cell types to act as second messengers in redox-sensitive pathways. A NADPH oxidase has been initially described as the respiratory burst enzyme in neutrophils. Stimulation of this complex enzyme system requires specific signaling cascades linking it to membrane-receptor activation. Subsequently, a family of NADPH oxidases has been identified in various nonphagocytic cells. They mainly differ in containing one out of seven homologous catalytic core proteins termed NOX1 to NOX5 and DUOX1 or 2. NADPH oxidase activity is controlled by regulatory subunits, including the NOX regulators p47phox and p67phox, their homologs NOXO1 and NOXA1, or the DUOX1 or 2 regulators DUOXA1 and 2. In addition, the GTPase Rac modulates activity of several of these enzymes. Recently, additional proteins have been identified that seem to have a regulatory function on NADPH oxidase activity under certain conditions. We will thus summarize molecular pathways linking activation of different membrane-bound receptors with increased ROS production of NADPH oxidases.
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Affiliation(s)
- Andreas Petry
- Experimental Pediatric Cardiology, Technical University Munich, Munich, Germany
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55
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Curry FRE, Adamson RH. Vascular permeability modulation at the cell, microvessel, or whole organ level: towards closing gaps in our knowledge. Cardiovasc Res 2010; 87:218-29. [PMID: 20418473 PMCID: PMC2895542 DOI: 10.1093/cvr/cvq115] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 04/13/2010] [Accepted: 04/19/2010] [Indexed: 01/20/2023] Open
Abstract
Multiple processes modulate net blood-to-tissue exchange in a microvascular unit in normal and pathophysiological conditions. These include mechanisms that control the number and type of microvessels perfused, the balance of adhesion and contractile forces that determine the conductance of the spaces between endothelial cells to water and solutes, the pressure and chemical potential gradients determining the driving forces through these conductive pathways, and the organization of barriers to macromolecules in the endothelial glycocalyx. Powerful methods are available to investigate these mechanisms at the levels of cultured endothelial monolayers, isolated microvessels, and the microvascular units within intact organs. Here we focus on current problems that limit the integration of our knowledge of mechanisms investigated in detail at the cellular level into a more complete understanding of modulation of blood-to-tissue exchange in whole organs when the endothelial barrier is exposed to acute and more long-term inflammatory conditions. First, we review updated methods, applicable in mouse models of vascular permeability regulation, to investigate both acute and long-term changes in permeability. Methods to distinguish tracer accumulation due to change in perfusion from real increases in extravascular accumulation are emphasized. The second part of the review compares normal and increased permeability in individually perfused venular microvessels and endothelial cell monolayers. The heterogeneity of endothelial cell phenotypes in the baseline state and after exposure to injury and inflammatory conditions is emphasized. Lastly, we review new approaches to investigation of the glycocalyx barrier properties in cultured endothelial monolayers and in whole-body investigations.
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Affiliation(s)
- Fitz-Roy E Curry
- Department of Physiology and Membrane Biology, School of Medicine, University of California, 1 Shields Avenue, Davis, CA 95616, USA.
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Chen J, Yu H, Sun K, Song W, Bai Y, Yang T, Song Y, Zhang Y, Hui R. Promoter variant of angiopoietin-2 and plasma angiopoietin-2 are associated with risk of stroke recurrence in lacunar infarct patients. Biochem Biophys Res Commun 2010; 398:212-6. [DOI: 10.1016/j.bbrc.2010.06.062] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Accepted: 06/15/2010] [Indexed: 10/19/2022]
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van Nieuw Amerongen GP, Groeneveld ABJ. A plethora of angiopoietin-2 effects during clinical sepsis. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2010; 14:166. [PMID: 20587077 PMCID: PMC2911750 DOI: 10.1186/cc9053] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The interesting study by Davis and colleagues in the current issue of Critical Care expands on the increasingly recognized role of angiopoietins in human sepsis but raises a number of questions, which are discussed in this commentary. The authors describe an association between elevated angiopoietin (ang)-2 levels and impaired vascular reactivity, measured by the partly nitric oxide-dependent finger hyperemic response to forearm vascular occlusion, in patients with sepsis. This suggests that the ang-1/2-Tie2 system is involved in a number of pathophysiologic, phenotypic and perhaps prognostic alterations in human sepsis, on top of the effect on pulmonary endothelial barrier function. The novel inflammatory route may be a target for future therapeutic studies in human sepsis and acute lung injury, including those with activated protein C.
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Affiliation(s)
- Geerten P van Nieuw Amerongen
- Department of Physiology, Institute for Cardiovascular Research, Vrije Universiteit Medical Centre, 1081 HV Amsterdam, The Netherlands
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Ganta VC, Cromer W, Mills GL, Traylor J, Jennings M, Daley S, Clark B, Michael Mathis J, Bernas M, Jordan P, Witte M, Steven Alexander J, Alexander JS. Angiopoietin-2 in experimental colitis. Inflamm Bowel Dis 2010; 16:1029-39. [PMID: 19902545 PMCID: PMC2881632 DOI: 10.1002/ibd.21150] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND The pathophysiology of inflammatory bowel disease (IBD) includes leukocyte infiltration, blood and lymphatic remodeling, weight loss and protein enteropathy. The roles of angiopoietin-2 (Ang-2) in initiating gut inflammation, leukocyte infiltration and angiogenesis are not well understood. METHODS Disease activity index, histopathological scoring, myeloperoxidase assay, immunohistochemistry and sodium dodecyl sulphate- polyacrylamide gel electrophoretic methods were employed in the present study to address the roles of Ang-2 in experimental colitis. RESULTS Several important differences were seen in the development of experimental IBD in Ang-2(-/-) mice. Although weight change and disease activity differ only slightly in WT and Ang-2(-/-) + DSS treated mice, leukocyte infiltration, inflammation and blood and lymphatic vessel density is significantly attenuated compared to WT + DSS mice. Gut capillary fragility and water export (stool blood and form) appear significantly earlier in Ang-2(-/-) + DSS mice vs. WT. Colon lengths were also significantly reduced in Ang-2(-/-) and gut histopathology was less severe in Ang-2(-/-) compared to WT + DSS. Lastly, the decrease in serum protein content in WT + DSS was less severe in Ang-2(-/-) + DSS, thus protein losing enteropathy (PLE) a feature of IBD is relieved by Ang-2(-/-). CONCLUSION These data demonstrate that in DSS colitis, Ang-2 mediates inflammatory hemangiogenesis, lymphangiogenesis and neutrophil infiltration to reduce some, but not all clinical features of IBD. The implications for Ang-2 manipulation in the development of IBD and other inflammatory diseases and treatments involving Ang-2 are discussed.
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Affiliation(s)
- Vijay C. Ganta
- Department of Molecular and Cellular Physiology, Louisiana Health Sciences Centre-Shreveport, Louisiana
| | - Walter Cromer
- Department of Cell Biology and Anatomy Louisiana Health Sciences Centre-Shreveport, Louisiana
| | - Ginny L. Mills
- Department of Molecular and Cellular Physiology, Louisiana Health Sciences Centre-Shreveport, Louisiana
| | - James Traylor
- Department of Pathology Louisiana Health Sciences Centre-Shreveport, Louisiana
| | - Merilyn Jennings
- Department of Molecular and Cellular Physiology, Louisiana Health Sciences Centre-Shreveport, Louisiana
| | - Sarah Daley
- Department of Surgery, University of Arizona, Arizona
| | - Benjamin Clark
- Department of Molecular and Cellular Physiology, Louisiana Health Sciences Centre-Shreveport, Louisiana
| | - J. Michael Mathis
- Department of Cell Biology and Anatomy Louisiana Health Sciences Centre-Shreveport, Louisiana
| | | | - Paul Jordan
- Department of Gastroenterology, University of Arizona, Arizona
| | - Marlys Witte
- Department of Surgery, University of Arizona, Arizona
| | - J. Steven Alexander
- Department of Molecular and Cellular Physiology, Louisiana Health Sciences Centre-Shreveport, Louisiana
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van der Heijden M, van Nieuw Amerongen GP, van Hinsbergh VWM, Groeneveld ABJ. The interaction of soluble Tie2 with angiopoietins and pulmonary vascular permeability in septic and nonseptic critically ill patients. Shock 2010; 33:263-8. [PMID: 19543148 DOI: 10.1097/shk.0b013e3181b2f978] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Circulating angiopoietin (Ang) 1 may inhibit and Ang-2 may enhance pulmonary vascular permeability in septic and nonseptic patients with or at risk for acute lung injury or acute respiratory distress syndrome. We hypothesized that the soluble form of the Ang-binding Tie2 receptor (sTie2), whose shedding may be induced by vascular endothelial growth factor (VEGF) levels, may bind circulating Angs and thereby inhibit their effects on pulmonary vascular permeability. In 24 septic and 40 nonseptic mechanically ventilated patients, sTie2, Ang-1, Ang-2, and VEGF plasma levels were measured together with the pulmonary leak index (PLI) for (67)Gallium-labeled transferrin as a measure of pulmonary vascular permeability. Soluble Tie2 and VEGF levels correlated (r = 0.53, P = 0.001). Soluble Tie2 was higher in septic than in nonseptic patients (7.43 [6.57 - 8.40] vs. 5.03 [4.57 - 5.54] ng/mL; P < 0.001). Soluble Tie2 was associated with the PLI (standardized regression coefficient [beta] = 0.26; P = 0.006) but lost its association with the PLI when the Angs were included in a multivariate model. Soluble Tie2 did not affect the association between Ang-1 or Ang-2 and the PLI (beta = -0.39, P < 0.001; beta = 0.52, P < 0.001, respectively), independently of underlying disease. Although limited to correlations and associations, the clinical data support in vivo shedding of sTie2 through VEGF signaling upon pulmonary vascular injury. However, this shedding may not prevent a direct role of Angs in pulmonary vascular permeability.
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Affiliation(s)
- Melanie van der Heijden
- Department of Intensive Care, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands.
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Liu SN, Shi L, Li M, Lv XX, Kan J, Ma JZ, Chen LY. Effects of Qizhu granules on Ang-1, Ang-2/Tie-2 signal transduction pathways in CCl 4-induced liver fibrosis rats. Shijie Huaren Xiaohua Zazhi 2009; 17:2495-2498. [DOI: 10.11569/wcjd.v17.i24.2495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To observe the effects of Qizhu granules on Angiopoietin-1, Angiopoietin-2/Tie-2 signal transduction pathways in CCl4-induced liver fibrosis rats.
METHODS: The rats were randomly divided into blank, model, Qizhu granules and tablet of compound Biejia ruangan groups. Liver fibrosis rat models were replicated by CCl4, Qizhu granules and tablets of compound Biejia ruangan were given. And 4 weeks later, liver tissues of each rat were collected and the expression quantity of Angiopoietin-1 mRNA, Angiopoietin-2 mRNA and Tie-2 mRNA was detected by real-time fluorescence quantitative PCR.
RESULTS: The Ang-1 mRNA expression quantity of Qizhu granules was obviously lower than that of the model group (0.32 ± 0.11 vs 0.66 ± 0.80, P < 0.01). The Ang-2 mRNA expression quantity was higher than that of the model group (0.27 ± 0.34 vs 0.09 ± 0.01, P < 0.05). There was no significant difference in the expression quantity of Ang-1 mRNA, Ang-2 mRNA and Tie-2 mRNA between groups of Qizhu granules and compound Biejia ruangan.
CONCLUSION: Qizhu granules can alleviate liver fibrosis by intervening liver sinusoidal capillarization, and one of its mechanisms is to regulate the expression of Angiopoietin-1 mRNA, Angiopoietin-2 mRNA and Tie-2 mRNA.
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van der Heijden M, Pickkers P, van Nieuw Amerongen GP, van Hinsbergh VWM, Bouw MPWJM, van der Hoeven JG, Groeneveld ABJ. Circulating angiopoietin-2 levels in the course of septic shock: relation with fluid balance, pulmonary dysfunction and mortality. Intensive Care Med 2009; 35:1567-74. [PMID: 19551369 PMCID: PMC2726915 DOI: 10.1007/s00134-009-1560-y] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Accepted: 06/07/2009] [Indexed: 11/28/2022]
Abstract
PURPOSE To investigate whether angiopoietin-2, von Willebrand factor (VWF) and angiopoietin-1 relate to surrogate indicators of vascular permeability, pulmonary dysfunction and intensive care unit (ICU) mortality throughout the course of septic shock. METHODS In 50 consecutive mechanically ventilated septic shock patients, plasma angiopoietin-2, VWF and angiopoietin-1 levels and fluid balance, partial pressure of oxygen/inspiratory oxygen fraction and the oxygenation index as indicators of vascular permeability and pulmonary dysfunction, respectively, were measured until day 28. RESULTS Angiopoietin-2 positively related to the fluid balance and pulmonary dysfunction, was higher in non-survivors than in survivors and independently predicted non-survival throughout the course of septic shock. VWF inversely related to the fluid balance and pulmonary dysfunction throughout the course of septic shock, was comparable between survivors and non-survivors and predicted non-survival on day 0 only. Angiopoietin-1 positively related to pulmonary dysfunction throughout the course, but did not differ between survivors and non-survivors. CONCLUSIONS In contrast to VWF, plasma angiopoietin-2 positively relates to fluid balance, pulmonary dysfunction and mortality throughout the course of septic shock, in line with a suggested mediator role of the protein.
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He P. Beyond tie-ing up endothelial adhesion: new insights into the action of angiopoietin-1 in regulation of microvessel permeability. Cardiovasc Res 2009; 83:1-2. [PMID: 19429667 DOI: 10.1093/cvr/cvp145] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Giuliano JS, Wheeler DS. Excess circulating angiopoietin-2 levels in sepsis: harbinger of death in the intensive care unit? CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2009; 13:114. [PMID: 19226440 PMCID: PMC2688109 DOI: 10.1186/cc7685] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The early recognition and management of sepsis remain the greatest challenges in the field of critical care medicine. Endothelial injury is one of the hallmarks of sepsis, leading to capillary leak, microcirculatory dysfunction, organ failure, and eventual death in many critically ill patients. The angiogenic growth factors, angiopoietin (angpt)-1 and angpt-2, act upon the Tie-2 receptor in opposing roles. Angpt-2 has been found in abundance in septic patients when compared with healthy controls. In the study by Kümpers and colleagues in the previous issue of Critical Care, angpt-2 levels correlated with markers of tissue hypoxia, disease severity, and mortality in septic adults. However, the temporal kinetics of the angiopoietins were not assessed. It remains to be seen whether angpt-2 levels will function solely as an early marker of sepsis or whether the manipulation of the angpt/Tie-2 system will become a rational therapeutic target for the management of sepsis.
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Affiliation(s)
- John S Giuliano
- Department of Pediatrics, Division of Critical Care Medicine, Yale University School of Medicine, Yale-New Haven Children's Hospital, New Haven, CT 06510, USA.
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