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Michael S Mulligan

Publications and source records attributed to Michael S Mulligan.

At least 19 recordsLinked to original sources
PubMed2006

A multicenter trial of an intrabronchial valve for treatment of severe emphysema.

OBJECTIVES: Minimally invasive endoscopic treatment of emphysema could provide palliation with less risk than lung volume reduction surgery and offer therapy to patients currently not considered for lung volume reduction surgery. The Intrabronchial Valve is used to block bronchial airflow in the most emphysematous areas of lung. METHODS: Patients with severe chronic obstructive pulmonary disease and heterogeneous upper lobe-predominant emphysema were eligible. Patients underwent flexible bronchoscopic placement of valves into segmental or subsegmental airways in both upper lobes. Outcomes assessed over a minimum of 6 months of follow-up included the safety, feasibility, tolerance, and success of valve placement; health-related quality of life; exercise capacity; pulmonary function; and gas exchange. RESULTS: Five centers treated 30 patients. Patient follow-up ranged from 1 to 12 months. A mean of 6.1 valves were placed per patient. Valves were positioned by means of flexible bronchoscopy in 99% of desired airways, and the procedure duration ranged from 15 to 125 minutes (mean, 65 minutes). Hospital discharge occurred within 2 days in 27 of 30 patients. There were no deaths or episodes of valve migration, tissue erosion, or significant bleeding. Eighty-three percent of patients had no adverse events judged probably or definitely related to the device. Patients experienced significant improvement in health-related quality of life, although the physiologic and exercise outcomes did not show statistically significant improvements. CONCLUSIONS: These first multicenter results with the Intrabronchial Valve demonstrate significant improvements in health-related quality of life and acceptable safety, ease of use, and procedural complication rates. The valve might be a safer and less-invasive alternative to surgical therapy for patients with severe emphysema.

Adult↗
PubMed2006

Crosstalk between thrombosis and inflammation in lung reperfusion injury.

BACKGROUND: Activation of extravascular coagulation has been reported in acute lung injury models of sepsis and acute respiratory distress syndrome. Thrombin, the main effector protease of extravascular coagulation, activates proinflammatory cell types, including macrophages, endothelial cells, and neutrophils, each of which participates in lung ischemia-reperfusion injury. We used hirudin, a potent, specific direct thrombin inhibitor, to define the role of thrombin in lung ischemia-reperfusion injury. METHODS: Rats were pretreated with hirudin 30 minutes before warm, in situ left lung ischemia and reperfusion. Multiple in vivo assessments of lung injury were determined, and mechanistic studies assessed transcriptional regulation early in reperfusion and proinflammatory protein secretion late in reperfusion. Immunohistochemistry localized thrombin activation. RESULTS: Thrombin localized to macrophages and endothelial and epithelial cells early in reperfusion. Hirudin significantly limited lung ischemia-reperfusion injury-induced derangements in vascular permeability and intraalveolar inflammatory cell sequestration, resulting in improved arterial oxygenation after ischemia and 4 hours of reperfusion. The protection was transcriptionally mediated by attenuated activator protein-1 and early growth response-1 transactivation, but not nuclear factor kappa B transactivation. This was associated with reduced chemokine, but not tumor necrosis factor alpha, secretion late in reperfusion. CONCLUSIONS: Thrombin promotes lung ischemia-reperfusion injury, as hirudin protected against experimental acute lung injury. Hirudin conferred protection through a mechanism independent of nuclear factor kappa B and tumor necrosis factor alpha, suggesting that its effects may be mediated by a parallel, synergistic inflammatory pathway through activator protein-1 and early growth response-1.

Animals↗
PubMed2006

Interleukin-6 regulation of direct lung ischemia reperfusion injury.

BACKGROUND: Lung ischemia reperfusion injury continues to adversely affect patient and graft survival after transplantation. While the role of interleukin-6 has been studied in ischemia-reperfusion models of intestine, liver, and heart, its participation in lung reperfusion injury has not been characterized. METHODS: We administered recombinant interleukin-6 to rat lungs through the intratracheal route before inducing left lung ischemia and reperfusion. Multiple in-vivo indicators of left lung injury were studied, as were transactivation patterns for nuclear factor kappa B and signal transduction and activators of transcription-3. Downstream effects on the elaboration of proinflammatory chemokines and cytokines were also studied. RESULTS: Recombinant interleukin-6 reduced endothelial disruption and neutrophil sequestration in left lung and alveolar spaces, resulting in improved oxygenation after ischemia and 4 hours of reperfusion. This protection was associated with decreased nuclear factor kappa B and signal transduction and activators of transcription-3 nuclear translocation early in reperfusion, and diminished proinflammatory mediator secretion late in reperfusion. CONCLUSIONS: Further studies focusing on the effects of recombinant interleukin-6 in large animal models are warranted, as this may be a novel strategy to improve outcomes after lung transplantation. Intratracheal administration may focus its efficacy on the lung while reducing effects on other organ systems during organ procurement.

Active Transport, Cell Nucleus↗
PubMed2005

Tissue inhibitor of metalloproteinase-1 deficiency abrogates obliterative airway disease after heterotopic tracheal transplantation.

Obliterative bronchiolitis (OB) is a major cause of allograft dysfunction after lung transplantation and is thought to result from immunologically mediated airway epithelial destruction and luminal fibrosis. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) have been implicated in the regulation of lung inflammation, airway epithelial repair, and extracellular matrix remodeling and therefore may participate in the pathogenesis of OB. The goals of this study were to determine the expression profiles of MMPs and TIMPs and the role of TIMP-1 in the development of airway obliteration using the murine heterotopic tracheal transplant model of OB. We demonstrate the selective induction of MMP-3, MMP-9, MMP-12, and TIMP-1 in a temporally restricted manner in tracheal allografts compared with isografts. In contrast, the expression of MMP-7, TIMP-2, and TIMP-3 was decreased in allografts relative to isografts during the period of graft rejection. TIMP-1 protein localized to epithelial, mesenchymal, and inflammatory cells in the tracheal grafts in a temporally and spatially restricted manner. Using TIMP-1-deficient mice, we demonstrate that the absence of TIMP-1 in the donor trachea or the allograft recipient reduced luminal obliteration and increased re-epithelialization in the allograft compared with wild-type control at 28 d after transplantation. Our findings provide direct evidence that TIMP-1 contributes to the development of airway fibrosis in the heterotopic tracheal transplant model, and suggest a potential role for this proteinase inhibitor in the pathogenesis of OB in patients with lung transplant.

Animals↗
PubMed2005

The effect of anti-inflammatory properties of mycophenolate mofetil on the development of lung reperfusion injury.

BACKGROUND: Lung ischemia-reperfusion injury (LIRI) is associated with an increased incidence of both primary graft failure and obliterative bronchiolitis. The immunosuppressant mycophenolate mofetil (MMF) has recently been shown to attenuate inflammatory injury in acute ischemia-reperfusion models via a mechanism that is presently unclear. These experiments studied the effects of MMF in a warm, in situ LIRI model, focusing on transcriptional regulation of pro-inflammatory mediators. METHODS: Left lungs of rats were rendered ischemic for 90 minutes and reperfused for up to 4 hours. Treated animals received 10 mg/kg of intravenous MMF at 2 hours before ischemia. Left lung injury was quantitated by myeloperoxidase (MPO) content, permeability indices and bronchoalveolar lavage (BAL) inflammatory cell counts. Lungs were analyzed by electrophoretic mobility shift assay (EMSA) for transcription factor transactivation and by enzyme-linked immunoassay for BAL chemokine protein content. RESULTS: MMF significantly reduced lung vascular permeability indices, MPO content and alveolar leukocyte counts at 4 hours of reperfusion. There was significant attenuation of activator protein 1 (AP-1) and early growth response 1 (EGR-1) transactivation, whereas nuclear factor-kappaB (NF-kappaB) was unaffected. Reductions in bronchoalveolar lavage monocyte chemoattractant protein 1 (MCP-1) and cytokine-induced neutrophil chemoattractant (CINC) protein content were found at 4 hours of reperfusion. CONCLUSIONS: MMF limits lung ischemia-reperfusion-induced increases in vascular permeability and inflammatory cell sequestration in lung parenchyma and alveolar spaces. The protection is mediated at the transcriptional level via an attenuation of early EGR-1 and AP-1 transactivation, which was found to be associated with reduced late MCP-1 and CINC protein secretion. The use of MMF in concert with an agent that affects NF-kappaB activation may provide even further protection against lung reperfusion injury as multiple inflammatory pathways are inhibited.

Animals↗
PubMed2005

The role of CC and CXC chemokines in cardiac allograft rejection in rats.

Acute cellular rejection is due in part to an upregulation of chemokine genes, resulting in eventual cell-mediated cytotoxicity. The role of chemokines in acute cardiac allograft rejection is not fully characterized presently. These studies compared the patterns of expression for multiple chemokines in rodent cardiac allograft rejection. Allogeneic transplants were performed from Brown-Norway donors to Lewis recipients. Survival studies utilized daily administration of neutralizing antisera to MCP-1, CINC, and MIP-1alpha. Patterns of mRNA and protein expression were determined by Northern blots and immunohistochemistry. Allogeneic controls rejected at mean of 6.5 days. Neutralization of MCP-1 (10.8 days, P<0.001) and MIP-1alpha (7.5 days, P=0.004) function, but not CINC (6.2 days, P>0.05), significantly prolonged allograft survival. Message expression for the beta chemokines studied were increased by day 2 and continued to increase until day 6 just before rejection, while CINC levels did not change as dramatically after day 2. Chemokine protein levels mirrored mRNA patterns by IHC analysis. MCP-1 and MIP-1alpha appear to play regulatory roles in cardiac allograft rejection, while CINC is expressed, but not functional, in injury development. Beta chemokine activity should be studied further in hope of developing more targeted immunosuppression, or identifying specific chemokines that may be useful for immunosurveillance purposes.

Animals↗
PubMed2005

Obliterative airway disease in rat tracheal allografts requires tumor necrosis factor alpha.

Obliterative bronchiolitis is the major complication affecting long-term lung transplant survivors. Tumor necrosis factor-alpha (TNF-alpha) promotes inflammation and fibrosis in chronic lung injury models. These experiments defined the role of TNF-alpha in an established model of obliterative airway disease (OAD). Rat tracheas were transplanted from Brown-Norway donors into Lewis recipients, and explanted on days 7 and 14. Treated groups received either anti-TNF-alpha antibodies or a novel TNF-alpha translational inhibitor, RDP-58, beginning either immediately or on post-transplant day 7. Morphometry assessed epithelial loss and luminal obliteration, while separate tracheas were processed for TNF-alpha mRNA expression by RQRT-PCR or protein localization/expression by immunohistochemistry. EMSAs evaluated NFkappaB activation. 14-day control allografts averaged 58% occlusion and 98% epithelial loss. These parameters were significantly improved with TNF-alpha inhibition, averaging 32% luminal obliteration and 37% epithelial preservation. TNF-alpha mRNA expression increased at 14-days relative to native tracheas, and was unchanged by RDP-58 treatment. However, TNF-alpha protein expression, localized to the mucosa/submucosa, was markedly reduced with RDP-58, and resulted in diminished global NFkappaB activation in allografts. Delayed RDP treatment reduced disease progression during the second week, as luminal occlusion increased from 26% to only 35%, while respiratory epithelium persisted at 21%. TNF-alpha promotes the development of OAD in tracheal allografts via an NFkappaB-dependent mechanism, and its inhibition may prove beneficial clinically.

Animals↗
PubMed2005

Cyclosporine modulates the response to hypoxia-reoxygenation in pulmonary artery endothelial cells.

BACKGROUND: Depletion of macrophages, neutrophils, or lymphocytes confers only partial protection against experimental lung reperfusion injury, suggesting that inflammatory responses in other cell types contribute to tissue injury. Endothelial cell activation has previously been shown to be critical to the development of ischemia-reperfusion injury in other vascular beds. Furthermore, cyclosporine (CSA) reduces in vivo lung reperfusion injury through attenuated secretion of proinflammatory mediators. These studies determined whether pulmonary artery endothelial cells (PAEC), subjected to hypoxia and reoxygenation, promote inflammation and whether CSA afforded any modulation of that response. METHODS: Isolated rat PAEC were subjected in vitro to 2 hours hypoxia followed by up to 4 hours reoxygenation. Cells were pretreated with CSA or a cremaphor vehicle. Differences in activation of signaling kinases and transcription factors were assessed, as was cytokine-chemokine protein secretion. RESULTS: There was significant signaling kinase (extracellular signal regulated kinase [ERK 1/2]) activation by 15 minutes reoxygenation, which was temporally associated with marked activation of the transcription factors nuclear factor kappa B (NFkappaB) and early growth response one (EGR-1). At 4 hours reoxygenation there were significant increases in chemokine protein secretion. The CSA decreased ERK 1/2 phosphorylation and significantly attenuated transcription factor transactivation at 15 minutes reoxygenation. The CSA was found to be selective in reducing cytokine-chemokine elaboration at 4 hours reoxygenation. CONCLUSIONS: Hypoxia-reoxygenation induces ERK 1/2 phosphorylation, as well as transactivation of the transcription factors NFkappaB and EGR-1 in PAEC. Cyclosporine selectively reduces proinflammatory mediator secretion, likely by transcriptional regulation through NFkappaB and EGR-1. This is the first demonstration of ERK 1/2 inhibition afforded by CSA.

Animals↗
PubMed2005

Poly (ADP) ribose polymerase inhibition improves rat cardiac allograft survival.

BACKGROUND: Heart transplantation is an accepted treatment modality for end-stage heart failure. However, acute cellular rejection (ACR) continues to be a morbid complication. Recently a novel mechanism of inflammatory allograft injury has been characterized which involves overactivation of the nuclear enzyme poly (ADP-ribose) polymerase (PARP). In the present studies, we compared the efficacy of INO-1001, a novel, potent PARP inhibitor, in limiting ACR with and without adjuvant low-dose cyclosporine (CSA). METHODS: Heterotopic heart transplantation was performed utilizing Brown-Norway strains as donors and Lewis rats as recipients. Groups received daily intraperitoneal injections of: vehicle, low-dose CSA, low-dose INO-1001, high-dose INO-1001, and low-dose CSA combined with high-dose INO-1001. Additional animals were sacrificed on postoperative Day 5 for histologic assessments of allograft inflammation, including immunohistochemistry for nitrotyrosine and poly (ADP-ribose) (the product of PARP) staining. RESULTS: PARP inhibition significantly prolonged allograft survival relative to vehicle controls. The combination of low-dose CSA and INO-1001 resulted in a marked increase in allograft survival and significant reductions in allograft rejection scores. This was associated with decreased nitrotyrosine and PAR staining in transplanted cardiac allografts. CONCLUSIONS: Pharmacologic inhibition of INO-1001 prolongs allograft survival in a dose-dependent fashion in a rodent model of heart transplantation. PARP inhibitors may permit reductions in the dose of CSA needed for adequate immunosuppression after heart transplantation.

Animals↗
PubMed2004

Intratracheal poly (ADP) ribose synthetase inhibition ameliorates lung ischemia reperfusion injury.

BACKGROUND: We previously demonstrated that intravenous poly (ADP) ribose synthetase (PARS) inhibition protects against experimental lung ischemia reperfusion injury (LIRI) in an in situ, hilar occlusion model. This study determined its efficacy when administered intratracheally (IT). METHODS: Left lungs of rats were rendered ischemic for 90 minutes, and reperfused for up to 4 hours. Treated animals received INO-1001, a PARS inhibitor, intratracheally 30 minutes before ischemia, while controls were given IT vehicle at equivalent volumes. All groups contained at least 4 animals. Lung injury was quantitated utilizing vascular permeability to radiolabeled albumin, tissue myeloperoxidase (MPO) content, alveolar leukocyte cell counts, and arterial pO(2) at 4 hours of reperfusion. Electrophoretic mobility shift assays (EMSA) assessed the nuclear translocation of NFkappaB and AP-1 in injured left lungs, while ELISAs quantitated secreted cytokine induced neutrophil chemoattractant (CINC) and MCP-1 protein in bronchoalveolar lavage fluid. RESULTS: Intratracheal PARS inhibition was 73% (p < 0.0001) and 87% (p < 0.0001) protective against increases in vascular permeability and alveolar leukocyte accumulation, respectively, and improved arterial pO(2) (p < 0.0004) at 4 hours of reperfusion. Myeloperoxidase (MPO) activity in treated lungs was reduced by 70% (p < 0.02). The nuclear translocation of NFkappaB and AP-1 was attenuated at 15 minutes of reperfusion, and the secretion of CINC and MCP-1 (p < 0.05) protein into the alveolus was diminished at 4 hours of reperfusion. CONCLUSIONS: Intratracheal INO-1001 protects against experimental LIRI. The reduction in secreted chemokine protein at 4 hours of reperfusion appears to be mediated at the pretranscriptional level through attenuated NFkappaB and AP-1 activation. This route may optimize future donor organ management and improve lung recipient outcomes.

Animals↗
PubMed2004

Poly (ADP) ribose synthetase inhibition reduces obliterative airway disease in rat tracheal allografts.

BACKGROUND: Obliterative bronchiolitis (OB) is the major long-term complication affecting lung transplant recipients, and is characterized pathologically by chronic inflammatory and fibroproliferative airway disease. Based on studies revealing anti-inflammatory and anti-apoptotic properties of poly (ADP)-ribose synthetase (PARS) inhibitors, we hypothesized that their administration would be protective in a heterotopic model of experimental OB. METHODS: We transplanted rat tracheas from Brown-Norway donors into Lewis recipients, and treated 2 groups with a novel PARS inhibitor, INO-1001. One group received 14 days of treatment, whereas a second received delayed treatment beginning on Day 7 post-transplant. Tracheas were analyzed by light microscopy and computerized morphometry. Effects on cytokine transcription, nuclear transcription factor activation and cellular death were assessed by in situ hybridization for tumor necrosis factor-alpha (TNF-alpha), electromobility shift assays for nuclear factor-kappaB (NF-kappaB) and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assays, respectively. RESULTS: PARS inhibition significantly decreased luminal obstruction (p < 0.001) and enhanced preservation of epithelial lining (p < 0.001) at 14 days post-transplant. Day 7 controls confirmed the development of an obstructive lesion in the lumen, averaging 28% occlusion. Delayed treatment (beginning on Day 7) arrested (p < 0.001) progression of the established lesion. Allograft airways treated with INO-1001 demonstrated attenuated NF-kappaB nuclear translocation, reduced transcription of TNF-alpha mRNA, and decreased cellular death on TUNEL and caspase 3 staining. CONCLUSIONS: PARS inhibition is anti-inflammatory, protects against experimental OB, and is associated with enhanced preservation of respiratory epithelium and decreased cellular death. Delayed treatment with INO-1001 arrests progression of the lesion developed by Day 7. These studies suggest that activation of PARS plays a critical role in the development of airway obliterative disease.

Animals↗
PubMed2004

Role of poly (ADP) ribose synthetase in lung ischemia-reperfusion injury.

BACKGROUND: The activation of poly (adenosine diphosphate) ribose synthetase (PARS) is known to be important in the cellular response to oxidative stress. Previous studies have reported that PARS inhibition confers protection in models of endotoxic shock and ischemia-reperfusion. The purpose of this study was to determine the role of PARS inhibition in lung ischemia-reperfusion injury (LIRI). METHODS: Left lungs of Long-Evans rats were rendered ischemic for 90 minutes and reperfused for up to 4 hours. Treated animals received 3 mg/kg of INO-1001 (a PARS inhibitor) intravenously 30 minutes before ischemia. Injury was quantitated in terms of tissue myeloperoxidase (MPO) content, vascular permeability ((125)I radiolabeled bovine serum albumin extravasation) and bronchoalveolar lavage (BAL) leukocyte content. BAL fluid was assessed for cytokine and chemokine content by enzyme-linked immunoassay. Further samples were processed for nuclear protein analysis by electromobility shift assay (EMSA) and cellular death by terminal deoxyribonucleotidyl transferase-mediated d-UTP biotin nick-end labeling (TUNEL) assay and caspase-3 staining. RESULTS: Lung vascular permeability was reduced in treated animals by 73% compared with positive controls (p < 0.009). The protective effects of PARS inhibition correlated with a 46% reduction in tissue MPO content (p < 0.008) and marked reductions in BAL leukocyte accumulation. This positively correlated with the diminished expression of pro-inflammatory mediators and nuclear transcription factors, as well as decreased levels of cellular death. CONCLUSIONS: The deleterious effects of LIRI are in part mediated by the formation of free radicals and superoxides, which lead to DNA single-strand breaks. This leads to activation of PARS, which causes rapid cellular energy depletion and cell death. PARS inhibition is protective against this and represents a potentially useful therapeutic tool in the prevention of LIRI.

Animals↗
PubMed2004

FR167653 reduces obliterative airway disease in rats.

BACKGROUND: Obliterative bronchiolitis (OB) is the main cause of late mortality among long-term survivors of lung transplantation. Although p38 kinase is functional in multiple acute inflammatory injury models, its role in chronic lung rejection is undefined. p38 regulates the expression of the cytokines tumor necrosis (TNF)-alpha and interleukin (IL)-1beta, 2 mediators involved in the development of OB in a tracheal transplant model. These studies assessed whether specific inhibition of p38 with FR167653 (FR) protects against the development of OB in rat tracheal allografts. METHODS: Rat airways were heterotopically transplanted from Brown-Norway donors into Lewis recipients, and animals were sacrificed on day 14 (6 per group). Treated animals received 10 mg/kg daily of FR intraperitoneally beginning either immediately or at day 7 after transplant. Allografts were assessed by computerized morphometry, and tracheas were processed for TNF-alpha mRNA and protein expression by quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry, respectively. Electrophoretic mobility shift assays evaluated nuclear factor kappa beta (NFkappaB) transactivation. RESULTS: Control allografts averaged 61% occlusion and 98% loss of epithelium at 14 days, whereas FR administration reduced luminal occlusion to 28% (p < 0.001) and epithelial loss to 71% (p < 0.001). Delayed treatment beginning on day 7 slowed progression of disease, as tracheal occlusion averaged 44% and epithelial loss averaged 80%, both of which were significant (p < 0.05) improvements relative to 14-day controls. NFkappa transactivation (p < 0.004) and TNF-alpha mRNA and protein expression were reduced dramatically by FR at 14 days. CONCLUSIONS: A specific p38 inhibitor, FR 167653, ameliorates obliterative airway disease in rat tracheal allografts via attenuated NFkappaB transactivation, which ultimately results in diminished TNF-alpha mRNA and protein expression.

Animals↗
PubMed2004

Early tumor necrosis factor-alpha release from the pulmonary macrophage in lung ischemia-reperfusion injury.

OBJECTIVE: Tumor necrosis factor-alpha is a proinflammatory mediator required for the development of experimental lung ischemia-reperfusion injury. The alveolar macrophage is a rich source of tumor necrosis factor-alpha in multiple models of acute lung injury. The present study was undertaken to determine whether the alveolar macrophage is an important source of tumor necrosis factor-alpha in lung ischemia-reperfusion injury and whether suppression of its function protects against injury. METHODS: Left lungs of Long-Evans rats underwent normothermic ischemia for 90 minutes and reperfusion for up to 4 hours. Treated animals received gadolinium chloride, a rare earth metal that inhibits macrophage function. Injury was quantitated via lung tissue neutrophil accumulation (myeloperoxidase content), lung vascular permeability, and bronchoalveolar lavage fluid leukocyte, cytokine, and chemokine content. Separate samples were generated for immunohistochemistry. RESULTS: Tumor necrosis factor-alpha secretion occurred at 15 minutes of reperfusion and was localized to the alveolar macrophage by immunohistochemistry. In gadolinium-treated animals, lung vascular permeability was reduced by 66% at 15 minutes (P <.03) of reperfusion and by 34% at 4 hours (P <.02) of reperfusion. Suppression of macrophage function resulted in a 35% reduction in lung myeloperoxidase content (P <.03) and similar reductions in bronchoalveolar lavage leukocyte accumulation. Tumor necrosis factor-alpha and microphage inflammatory protein-1alpha protein levels were markedly reduced in the bronchoalveolar lavage of gadolinium-treated animals by enzyme-linked immunosorbent assay. CONCLUSIONS: The alveolar macrophage secretes tumor necrosis factor-alpha protein by 15 minutes of reperfusion, which orchestrates the early events that eventually result in lung ischemia-reperfusion injury at 4 hours. Gadolinium pretreatment markedly reduces tumor necrosis factor-alpha elaboration, resulting in significant protection against lung ischemia-reperfusion injury.

Animals↗
PubMed2004

Endotracheal calcineurin inhibition ameliorates injury in an experimental model of lung ischemia-reperfusion.

OBJECTIVES: We previously demonstrated that calcineurin inhibitors given intravenously ameliorate experimental lung ischemia-reperfusion injury. This study evaluates whether these effects can be achieved when these agents are delivered endotracheally. METHODS: Left lungs of Long Evans rats were rendered ischemic for 90 minutes and reperfused for up to 4 hours. Treated animals received tacrolimus endotracheally at doses of 0.2, 0.1, or 0.025 mg/kg 60 minutes before ischemia. Injury was quantitated in terms of vascular permeability. Additional animals treated at a dose of 0.1 mg/kg were assessed for lung tissue myeloperoxidase content and bronchoalveolar lavage leukocyte content. Bronchoalveolar lavage fluid was assessed for cytokine and chemokine content by enzyme-linked immunosorbent assay. Tissue samples were processed for nuclear factor-kappaB activation, and blood levels of tacrolimus were measured in treated animals. RESULTS: Left lung vascular permeability was reduced in treated animals in a dose-dependent fashion compared with controls. The protective effects correlated with a 47% (0.50% +/- 0.06% vs 0.27% +/- 0.08%, respectively) reduction in tissue myeloperoxidase content (P <.004) and marked reductions in bronchoalveolar lavage leukocyte accumulation. This protection was also associated with decreased nuclear factor-kappaB activation and diminished expression of proinflammatory mediators. Blood tacrolimus levels in treated animals at 4 hours of reperfusion were undetectable. CONCLUSIONS: Tacrolimus administered endotracheally is protective against lung ischemia-reperfusion injury in our model. This protection is associated with a decrease in nuclear factor-kappaB activation. This route of tacrolimus administration broadens its potential clinical use and decreases concerns about systemic and renal toxicity. It may be a useful therapy in lung donors to protect against lung ischemia-reperfusion injury.

Animals↗
PubMed2004

Beta-chemokine function in experimental lung ischemia-reperfusion injury.

BACKGROUND: Although chemokines are functionally important in models of ischemia-reperfusion injury, little is known about their role in lung ischemia-reperfusion injury (LIRI). This study examined the role of the beta-chemokines, macrophage inflammatory protein (MIP)-1alpha, monocyte chemoattractant protein (MCP)-1, and regulated upon activation normal T cells expressed and secreted (RANTES) in LIRI. METHODS: Left lungs of Long-Evans rats underwent normothermic ischemia for 90 minutes and reperfusion for up to 4 hours. Treated animals received anti-MIP-1alpha, anti-MCP-1, or anti-RANTES antibodies before reperfusion. Changes in lung vascular permeability were measured with iodine 125-labeled bovine serum albumin. Neutrophil accumulation in the lung parenchyma was determined by myeloperoxidase activity, and bronchoalveolar lavage was performed to measure leukocyte cell counts. Western blots, Northern blots, and ribonuclease protection assays assessed beta-chemokine messenger RNA and protein levels. RESULTS: Animals receiving anti-MIP-1alpha demonstrated reduced vascular permeability compared with controls (p < 0.001). Attenuation of permeability was less dramatic in animals treated with anti-MCP-1 and anti-RANTES antibody, which demonstrated permeability decreases of 15% and 16%, respectively (p < 0.02). Lung neutrophil accumulation was reduced in animals receiving anti-MIP-1alpha antibody (p < 0.005) but was unchanged in animals receiving either anti-MCP-1 or anti-RANTES. Bronchoalveolar lavage leukocyte content was also reduced by treatment with anti-MIP-1alpha (p < 0.003) and was unchanged in anti-MCP-1-treated and anti-RANTES-treated animals. MIP-1alpha treatment decreased tumor necrosis factor-alpha messenger RNA in injured left lungs. CONCLUSIONS: MIP-1alpha is functionally significant in the development of LIRI. It likely exerts its effects in part by mediating the expression of proinflammatory and antiinflammatory cytokines and influencing tissue neutrophil recruitment. MCP-1 and RANTES seem to play relatively minor roles in the development of direct LIRI.

Animals↗
PubMed2004

Novel broad-spectrum chemokine inhibitor protects against lung ischemia-reperfusion injury.

BACKGROUND: Functional roles for chemokines have been demonstrated in several models of ischemia-reperfusion injury. The redundancy inherent to chemokine pathways makes administration of neutralizing antibodies to any single chemokine ineffective in ameliorating injury. This study was undertaken to define the pattern of chemokine expression in lung ischemia-reperfusion injury (LIRI), and to determine whether a broad-spectrum chemokine inhibitor, NR58-3.14.3, could confer significant protection against LIRI. METHODS: Left lungs of rats were rendered ischemic for 90 minutes and then reperfused for 4 hours. Chemokine secretion into the alveolar space was quantified by enzyme-linked immunoassay. Treated animals received NR58-3.14.3 prior to reperfusion. Vascular injury was measured by lung permeability index, neutrophil accumulation in lung parenchyma was determined by myeloperoxidase (MPO) activity, and alveolar leukocyte counts were quantified in bronchoalveolar lavage (BAL) effluent. A ribonuclease protection assay evaluated mRNA expression of various chemokines. RESULTS: Lavage effluent in untreated animals demonstrated significant increases in the secretion of cytokine-induced neutrophil chemoattractant (CINC), tumor necrosis factor-alpha (TNF-alpha), macrophage inflammatory protein-2 (MIP-2), MIP-1alpha and monocyte chemoattractant protein-1 (MCP-1). Animals receiving NR58-3.14.3 demonstrated a 37% (p < 0.001) reduction in vascular injury and a marked reduction in lung MPO activity (p < 0.001) and alveolar cell counts (p = 0.005). Chemokine inhibition decreased mRNA expression of a number of early response cytokines when compared with positive control animals, and caused a significant decrease (p < 0.04) in the secretion of TNF-alpha. CONCLUSIONS: These studies demonstrate that chemokines are expressed after lung ischemia and reperfusion, and that broad-spectrum chemokine inhibition ameliorates reperfusion injury. mRNA expression of early response cytokines was modulated, and the secretion of TNF-alpha was decreased.

Animals↗