Article

Proinflammatory response of alveolar epithelial cells is enhanced by alveolar macrophage-produced TNF- during pulmonary ischemia-reperfusion injury

Department of Surgery, University of Virginia, Charlottesville, Virginia, United States
AJP Lung Cellular and Molecular Physiology (Impact Factor: 4.08). 08/2007; 293(1):L105-13. DOI: 10.1152/ajplung.00470.2006
Source: PubMed

ABSTRACT

Pulmonary ischemia-reperfusion (IR) injury entails acute activation of alveolar macrophages followed by neutrophil sequestration. Although proinflammatory cytokines and chemokines such as TNF-alpha and monocyte chemoattractant protein-1 (MCP-1) from macrophages are known to modulate acute IR injury, the contribution of alveolar epithelial cells to IR injury and their intercellular interactions with other cell types such as alveolar macrophages and neutrophils remain unclear. In this study, we tested the hypothesis that following IR, alveolar macrophage-produced TNF-alpha further induces alveolar epithelial cells to produce key chemokines that could then contribute to subsequent lung injury through the recruitment of neutrophils. Cultured RAW264.7 macrophages and MLE-12 alveolar epithelial cells were subjected to acute hypoxia-reoxygenation (H/R) as an in vitro model of pulmonary IR. H/R (3 h/1 h) significantly induced KC, MCP-1, macrophage inflammatory protein-2 (MIP-2), RANTES, and IL-6 (but not TNF-alpha) by MLE-12 cells, whereas H/R induced TNF-alpha, MCP-1, RANTES, MIP-1alpha, and MIP-2 (but not KC) by RAW264.7 cells. These results were confirmed using primary murine alveolar macrophages and primary alveolar type II cells. Importantly, using macrophage and epithelial coculture methods, the specific production of TNF-alpha by H/R-exposed RAW264.7 cells significantly induced proinflammatory cytokine/chemokine expression (KC, MCP-1, MIP-2, RANTES, and IL-6) by MLE-12 cells. Collectively, these results demonstrate that alveolar type II cells, in conjunction with alveolar macrophage-produced TNF-alpha, contribute to the initiation of acute pulmonary IR injury via a proinflammatory cascade. The release of key chemokines, such as KC and MIP-2, by activated type II cells may thus significantly contribute to neutrophil sequestration during IR injury.

Download full-text

Full-text

Available from: Victor E Laubach
  • Source
    • "It is believed that the antiinflammatory nature of HDL-C could also be beneficial in other inflammatory diseases as sepsis or rheumatoid arthritis [8, 9]. Inflammatory processes precede or develop at cerebral death of the donor and follow the graft in subsequent phases of conservation and surgery during lung transplantation101112. We have previously shown that pretransplant dyslipidaemia determines outcome in lung transplant recipients [13], but up to now, the role of lipids in lung patients has been poorly investigated. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Objectives: Primary graft dysfunction (PGD) is a major cause of mortality within the first year following lung transplantation. Pulmonary hypertension, elevated body mass index (BMI), prolonged ischaemic time of the graft, intraoperative blood transfusions >1000 ml and the use of cardiopulmonary bypass or extracorporeal membrane oxygenation increase the risk for PGD. We aimed to evaluate whether dyslipidaemia is an additional risk factor for the development of PGD. Methods: We retrospectively analysed demographic and clinical data of 264 patients who received their first bilateral lung transplantation between March 2000 and October 2013 at our institution. The endpoint was PGD grade 3 at any time, defined according to the International Society for Heart and Lung Transplantation (ISHLT) criteria. Fasting lipid profiles at listing time or just before transplantation (baseline) were documented and dyslipidaemia was defined as any of the parameters being out of range. Comparisons of continuous variables between patients with PGD grade 3 and patients without were performed with the Mann-Whitney U-test, whereas proportions were compared with the χ(2) test. Continuous variables were presented as arithmetic means with standard deviation for ease of comparison, but levels of statistical significance were computed using the appropriate non-parametric statistical test. To identify PGD risk factors, a forward stepwise logistic regression model was used. Results: PGD occurred in 63 recipients (24%). Pretransplant dyslipidaemia was documented in 153 recipients (58%) and was significantly more prevalent among recipients developing PGD (45 vs 108, P < 0.013). Despite various underlying pulmonary pathologies, higher triglyceride (TG) levels (1.41 ± 0.78 vs 1.16 ± 0.78, P < 0.012), lower high-density lipoprotein-cholesterol (HDL-C) concentrations (1.24 ± 0.55 vs 1.57 ± 0.71, P < 0.0005) and higher cholesterol/HDL-C values (3.80 ± 2.02 vs 3.00 ± 0.92, P < 0.0005) were associated with a lower incidence of PGD. Patients with PGD had significantly longer ischaemic time (350 ± 89 vs 322 ± 91, P = 0.017) and higher BMI (23 ± 5 vs 21 ± 4.4, P < 0.007). Conclusion: Dyslipidaemia seems to be an independent risk factor for PGD after lung transplantation: low circulating levels of HDL-C and hypertriglyceridaemia increase the incidence of PGD. Even if HDL-C levels are difficult to alter today, triglyceride and cholesterol levels can be addressed therapeutically and may have a positive influence on the development of PGD.
    Full-text · Article · Dec 2015 · Interactive Cardiovascular and Thoracic Surgery
  • Source
    • "These results suggest that the cytokine and chemokine response provoked by LPS varies between different cell types and that epithelial cells also contribute to the enhanced acute lung inflammation by augmenting the chemokine response. It has been demonstrated that alveolar macrophage-derived TNF-α induces alveolar epithelial cells to produce chemokines, resulting in subsequent lung injury [23], [29]. Thus, alveolar macrophages appear to interact with epithelial cells and contribute to the evolution of acute lung inflammation. "
    [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Acute respiratory distress syndrome (ARDS) is a severe and life-threatening acute lung injury (ALI) that is caused by noxious stimuli and pathogens. ALI is characterized by marked acute inflammation with elevated alveolar cytokine levels. Mitogen-activated protein kinase (MAPK) pathways are involved in cytokine production, but the mechanisms that regulate these pathways remain poorly characterized. Here, we focused on the role of Sprouty-related EVH1-domain-containing protein (Spred)-2, a negative regulator of the Ras-Raf-extracellular signal-regulated kinase (ERK)-MAPK pathway, in lipopolysaccharide (LPS)-induced acute lung inflammation.
    Full-text · Article · Oct 2014 · PLoS ONE
  • Source
    • "However, neither dosage of ibuprofen could reduce BALF IL-1β concentration. The expression of RANTES in the airway has been shown to increase in ischemia reperfusion-induced lung injury and respiratory virus infection [32]. Growth factors such as GM-CSF and IFN-γ drive the differentiation and activation of macrophage progenitors or lineage precursors [33]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Background: Ventilator-induced lung injury-(VILI-) induced endothelial permeability is regulated through the Rho-dependent signaling pathway. Ibuprofen inhibits Rho activation in animal models of spinal-cord injury and Alzheimer's disease. The study aims to investigate ibuprofen effects on high tidal volume associated VILI. Methods: Twenty-eight adult male Sprague-Dawley rats were randomized to receive a ventilation strategy with three different interventions for 2 h: (1) a high-volume zero-positive end-expiratory pressure (PEEP) (HVZP) group; (2) an HVZP + ibuprofen 15 mg/kg group; and (3) an HVZP + ibuprofen 30 mg/kg group. A fourth group without ventilation served as the control group. Rho-kinase activity was determined by ratio of phosphorylated ezrin, radixin, and moesin (p-ERM), substrates of Rho-kinase, to total ERM. VILI was characterized by increased pulmonary protein leak, wet-to-dry weight ratio, cytokines level, and Rho guanine nucleotide exchange factor (GEF-H1), RhoA activity, p-ERM/total ERM, and p-myosin light chain (MLC) protein expression. Results: Ibuprofen pretreatment significantly reduced the HVZP ventilation-induced increase in pulmonary protein leak, wet-to-dry weight ratio, bronchoalveolar lavage fluid interleukin-6 and RANTES levels, and lung GEF-H1, RhoA activity, p-ERM/total ERM, and p-MLC protein expression. Conclusion: Ibuprofen attenuated high tidal volume induced pulmonary endothelial hyperpermeability. This protective effect was associated with a reduced Rho-kinase activity.
    Full-text · Article · Jun 2014 · BioMed Research International
Show more