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Non muscle myosin light chain kinase isoform is an attractive molecular target in acute inflammatory lung injury

ABSTRACT: Acute lung injury (ALI), a major cause of acute respiratory failure with high morbidity and mortality, isare characterized by significant pulmonary inflammation and both alveolar and vascular barriers dysfunction. In Pprior studies have highlighted the role of nonmuscle myosin light chain kinase (nmMLCK) as an essential element of inflammatory response with MYLK polymorphisms associated withwhich alters ALI susceptibility. In the present study we sought to further define nmMLCK in acute inflammatory syndromes and examined We examined nmMLCK as a molecular target involved in increase of lung epithelial and endothelial barrier permeability. We utilized in two muirine models of inflammatory lung injury: intratracheal administration of endotoxin/lipopolysaccharide (LPS, 2.5 mg/kg) and VILI (ventilator-induced lung injury, tidal volume 40ml/kg). Two complementary strategies were used to reduce nmMLCK activity or expression. We found that membrane permeant oligopeptide, PIK, inhibited MLC kinase activity in vitro in aand displayed dose-dependent mannerinhibition of MLC kinase activity.. Intravenous delivery of PIK significantly attenuated LPS-induced lung inflammation reflected by decreasing accumulation of bronchoalveolar lavage (BAL) albumin (~ 50% reduction) as well as reduction in BAL cells, tissue MPO activity and tissue albumin in lung homogenates. A second regulatory approach explored targeting murine nmMLCK by administration of siRNA (5mg/kg) 3 days prior to LPS challenge. siRNA decreased of nmMLCK expression in lungs (~ 70% reduction) and resulted in significant attenuation LPS-induced lung inflammation (~ 40% reduction) as reflected by decreased BAL protein level and BAL cells. For targeting pulmonary vessels nmMLCK we used ACE antibody-conjugated liposomes with nmMLCK siRNA in murine ventilator-induced lung injury (VILI) model. Protein silencing of nmMLCK was evident by immunohistochemical analysis with a decrease in relative intensity of fluorescence in lung vessels compared with control animals. Furthermore, the inhibition of nmMLCK expression by siRNA in vessels significantly attenuated VILI lung injury as reflected by decreased BAL protein level (40% reduction). Finally, MLCK knockout mice were significantly protected (reduced BAL protein and albumin) when exposed to a model of severe VILI (4h, 40ml/kg tidal volume). Conclusion: the MLCK gene KO and chemical biology results indicate that the targeting of nmMLCK in vivo attenuate the severity of LPS-induced or VILI acute lung injury. We used microarrays to detail the global programme of gene expression induced by VILI in Wild type and nmMLCK-/- mouse.

ORGANISM(S): Mus musculus

PROVIDER: GSE14525 | GEO | 2009/03/02

SECONDARY ACCESSION(S): PRJNA111603

REPOSITORIES: GEO

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Project description:Acute lung injury (ALI), a major cause of acute respiratory failure with high morbidity and mortality, isare characterized by significant pulmonary inflammation and both alveolar and vascular barriers dysfunction. In Pprior studies have highlighted the role of nonmuscle myosin light chain kinase (nmMLCK) as an essential element of inflammatory response with MYLK polymorphisms associated withwhich alters ALI susceptibility. In the present study we sought to further define nmMLCK in acute inflammatory syndromes and examined We examined nmMLCK as a molecular target involved in increase of lung epithelial and endothelial barrier permeability. We utilized in two muirine models of inflammatory lung injury: intratracheal administration of endotoxin/lipopolysaccharide (LPS, 2.5 mg/kg) and VILI (ventilator-induced lung injury, tidal volume 40ml/kg). Two complementary strategies were used to reduce nmMLCK activity or expression. We found that membrane permeant oligopeptide, PIK, inhibited MLC kinase activity in vitro in aand displayed dose-dependent mannerinhibition of MLC kinase activity.. Intravenous delivery of PIK significantly attenuated LPS-induced lung inflammation reflected by decreasing accumulation of bronchoalveolar lavage (BAL) albumin (~ 50% reduction) as well as reduction in BAL cells, tissue MPO activity and tissue albumin in lung homogenates. A second regulatory approach explored targeting murine nmMLCK by administration of siRNA (5mg/kg) 3 days prior to LPS challenge. siRNA decreased of nmMLCK expression in lungs (~ 70% reduction) and resulted in significant attenuation LPS-induced lung inflammation (~ 40% reduction) as reflected by decreased BAL protein level and BAL cells. For targeting pulmonary vessels nmMLCK we used ACE antibody-conjugated liposomes with nmMLCK siRNA in murine ventilator-induced lung injury (VILI) model. Protein silencing of nmMLCK was evident by immunohistochemical analysis with a decrease in relative intensity of fluorescence in lung vessels compared with control animals. Furthermore, the inhibition of nmMLCK expression by siRNA in vessels significantly attenuated VILI lung injury as reflected by decreased BAL protein level (40% reduction). Finally, MLCK knockout mice were significantly protected (reduced BAL protein and albumin) when exposed to a model of severe VILI (4h, 40ml/kg tidal volume). Conclusion: the MLCK gene KO and chemical biology results indicate that the targeting of nmMLCK in vivo attenuate the severity of LPS-induced or VILI acute lung injury. We used microarrays to detail the global programme of gene expression induced by VILI in Wild type and nmMLCK-/- mouse. Experiment Overall Design: four group (n=3) of animals were treated by SB (Spontaneouse breathing) or VILI (4 hours, 30 ml/kg tidal volume) in Wild type or nmMLCK-/- animals;

Project description:Rationale: Using an ortholog candidate gene approach, we previously identified GADD45a (growth arrest and DNA damage-inducible gene 45a) as a potential novel candidate involved in ventilator-induced lung injury (VILI). Objectives: We investigated whether genetically engineered mice with GADD45a deletion were more susceptible to ventilator- or endotoxin (LPS)-induced lung injury. We employed genomic strategies to explore the mechanistic involvement of GADD45a in inflammatory lung injury. Methods: Wild-type C57Bl/6 and GADD45a-/- mice were phenotyped for lung injury following exposure to high tidal volume ventilation (VILI) or intratracheal LPS. Whole lung homogenates were utilized for gene expression studies of ventilated animals and spontaneously breathing controls. To explore the consequences of GADD45a depletion on lung vascular permeability, electrical resistance was measured using human endothelial cells (EC) transfected with small interfering RNA (siRNA) specific for GADD45a or control sequence, or with active Akt1/PKBï¡ cDNA. Results: Mice harboring deletion of GADD45a were modestly susceptible to LPS-induced injury and profoundly susceptible to VILI, demonstrating increased inflammation and increased microvascular permeability. VILI-exposed GADD45a-/- mice manifested striking neutrophilic alveolitis and increased levels of BAL protein, IgG, and inflammatory cytokines. Expression profiling revealed strong dysregulation in the B cell receptor signaling pathway in GADD45a-/- mice, with involvement of several PI3K/Akt signaling components. Akt protein and phospho-Akt were reduced in GADD45a-/- lungs. Further, human EC with reduced GADD45a (siRNA) exhibited potentiated LPS-induced barrier dysfunction, which was attenuated by overexpressing active Akt1. Conclusions: GADD45a, which modulates Akt availability, is a significant participant in modulating vascular permeability and susceptibility to VILI. Experiment Overall Design: 4 experimental groups, each with 3 mouses. Wild type control group, VILI group, GADD-/- group, GADD-/- and VILI group.

Project description:We have previously demonstrated that pre-B-cell colony enhancing factor (PBEF) ais a biomarker in sepsis and sepsis-induced acute lung injury (ALI) with genetic variants conferring ALI susceptibility118. In the current study, we explored the mechanistic participation of PBEF in ALI and ventilator-induced associated lung injury (VIALI). Initial in vitro studies and demonstrated rhPBEF aas a direct rat neutrophil chemotactic factor in vitro producing marked in vivo increases in BAL leukocytes (PMNs) in vivo following (intratracheal injection (,IT) in C57B6 mice. These latter changes were accompanied by increased BAL levels of the PMN chemoattractants (, KC and MIP2), and modest changes in lung vascular and but were not associated with significant increasesin alveolar permeability. We next explored the potential synergism between rhPBEF administration (IT) and a mechanical ventilation model of modest VILI lung injury (4 hours, 30 ml/kg tidal volume). We and observed dramatic synergistic increases in BAL PMNs, and both BAL protein and cytokine levels (IL-6, TNF-?, KC). Gene expression profiling Microarray analysis further supported a major role for PBEF in the induction of gene modules associated with ALI and VALI (NFkB pathway, leukocyte extravasation, apoptosis, toll receptor signaling). Finally, we exposed wild type and heterozygous PBEF+/- mice (targeted deletion of a single PBEF allele deletion) to a model of severe VILImechanical ventilation-induced lung injury (4 hours, 40 ml/kg tidal volume). PBEF+/- mice were significantly protected from VIALI-associated increases in BAL protein and BAL IL-6 levels and exhibited significantly reduced expression of ALI-associated gene expression modules. Together, these results indicate that PBEF is a key inflammatory mediator intimately involved in both the development and severity of ventilator-induced ALI. Experiment Overall Design: animals were treated by PBS, rhPBEF (IT administration), VILI (4 hours, 30 ml/kg tidal volume), or both.

Project description:We have previously demonstrated that pre-B-cell colony enhancing factor (PBEF) ais a biomarker in sepsis and sepsis-induced acute lung injury (ALI) with genetic variants conferring ALI susceptibility118. In the current study, we explored the mechanistic participation of PBEF in ALI and ventilator-induced associated lung injury (VIALI). Initial in vitro studies and demonstrated rhPBEF aas a direct rat neutrophil chemotactic factor in vitro producing marked in vivo increases in BAL leukocytes (PMNs) in vivo following (intratracheal injection (,IT) in C57B6 mice. These latter changes were accompanied by increased BAL levels of the PMN chemoattractants (, KC and MIP2), and modest changes in lung vascular and but were not associated with significant increasesin alveolar permeability. We next explored the potential synergism between rhPBEF administration (IT) and a mechanical ventilation model of modest VILI lung injury (4 hours, 30 ml/kg tidal volume). We and observed dramatic synergistic increases in BAL PMNs, and both BAL protein and cytokine levels (IL-6, TNF-?, KC). Gene expression profiling Microarray analysis further supported a major role for PBEF in the induction of gene modules associated with ALI and VALI (NFkB pathway, leukocyte extravasation, apoptosis, toll receptor signaling). Finally, we exposed wild type and heterozygous PBEF+/- mice (targeted deletion of a single PBEF allele deletion) to a model of severe VILImechanical ventilation-induced lung injury (4 hours, 40 ml/kg tidal volume). PBEF+/- mice were significantly protected from VIALI-associated increases in BAL protein and BAL IL-6 levels and exhibited significantly reduced expression of ALI-associated gene expression modules. Together, these results indicate that PBEF is a key inflammatory mediator intimately involved in both the development and severity of ventilator-induced ALI. We used microarrays to detail the global programme of gene expression induced by rhPBEF treatment and VALI. Experiment Overall Design: animals were treated by PBS, rhPBEF (IT administration), VILI (4 hours, 30 ml/kg tidal volume), or both.

Project description:Background: Microvascular injury and increased vascular leakage are prominent features of the radiation-induced lung injury (RILI) which follows cancerâ??associated thoracic irradiation. The mechanisms of RILI are incompletely understood and therapeutic strategies to limit RILI are currently unavailable. We established a murine model of radiation pneumonitis in order to assess mechanism-based therapies for RILI-induced inflammation and vascular barrier dysfunction. Based on prior studies, we investigated the therapeutic potential of simvastatin as a vascular barrier protective agent in RILI. Methods: C57BL6/J mice receiving single dose exposure to 18, 20, 22, or 25 Gy, (n=10/group) were temporally assessed (4-12 weeks) for cellular and biochemical indices of injury present in both bronchoalveolar lavage (BAL) and lung tissues (cytokines, tyrosine nitrosylated proteins, leukocytes, extravasation of Evans blue dye or EBD, BAL albumin, histology). In specific experiments, irradiated mice (25Gy) received simvastatin (10 mg/kg) via intraperitoneal injection three times a week (pre and post irradiation) for 2- 6 weeks post irradiation. Results. Acute RILI evolved in a dose- and time-dependent fashion. Mice irradiated with 25Gy exhibited modest increases in BAL leukocytes but significant increases in BAL IL-6 (p=0.03) and TNF-a (p=0.01) at 4 weeks compared to controls. Increases in BAL nitrotyrosine content peaked at 6 weeks (p=0.03) and was accompanied by marked nitrotyrosine immunostaining in lung tissues. Indices of increase lung vascular permeability such as EBD extravasation, BAL protein and BAL albumin significantly increased over time beginning at 6 weeks (p>0.002 all) with histological evidence of severe edema formation and airway inflammation. Simvastatin- treated irradiated mice were noted to exhibit marked attenuation of vascular leak with significantly decreased BAL protein (p=0.01) and inflammatory cell infiltration (50% reduction). Conclusion: Simvastatin is a potentially important therapeutic strategy to limit RILI and may influence radiation associated morbidity and mortality. We used microarrays to detail the global programme of gene expression induced by radiation in Wild type and the protection of SIMVA Experiment Overall Design: animals were treated by Vehical, Radiation (25Gy), SIMVA(10mg/kg), or both.

Project description:Lung transplantation remains the only viable therapy for patients with end-stage lung disease; however, full utilization of this treatment strategy is severely compromised by the lack of donor lung availability. For example, the vast majority of donor lungs available for transplantation are obtained from brain death (BD) individuals. Unfortunately, the autonomic storm which accompanies BD often results in neurogenic pulmonary edema (NPE), thereby either producing irreversible lung injury or leading to primary graft dysfunction following lung transplantation. We previously demonstrated that sphingosine 1-phosphate (S1P), a phospholipid angiogenic factor and major barrier-enhancing agent, as well as S1P analogues serve to reduce vascular permeability and ischemia/reperfusion (I/R) lung injury in rodents via ligation of the S1P1 receptor, S1PR1. As primary lung graft dysfunction is induced by lung vascular endothelial cell barrier dysfunction, we hypothesized that SEW-2871, a S1PR1 agonist, may attenuate NPE when administered to the donor shortly after BD. Significant lung injury was observed 4h after BD in a rat BD model with ~60% increases in BAL total protein, BAL cell counts, and lung tissue W/D weight ratios. In contrast, rats receiving SEW-2871 (0.1 mg/kg) 15 minutes after the induction of BD and assessed 4h later exhibited significant lung protection (~50% reduction, p=0.01) reflected by reduced BAL total protein, BAL cytokines concentrations, BAL albumin, BAL total cell count and lung tissue wet/dry (W/D) weights ratio. Microarray analysis at 4hrs revealed a global impact of both BD and SEW on lung gene expression with differential expression of a subclass of genes enriched in immune/inflammation response pathways across the 4 experimental groups. Overall, SEW served to attenuate the BD-mediated ie gene expression upregulation. Two potentially useful biomarkers, Tnf and Ccrl2, exhibited gene dysregulation by microarray analysis, which was validated by qPCR. We conclude that SEW-2871 significantly attenuates BD-induced lung injury and may serve as a potential candidate to improve human lung donor availability and transplantation outcomes. Animals were divided into four groups: sham, BD (A Fogarty catheter 4 Fr. was inserted and secured into the extradural space and inflated to induce BD), SEW (injection of SEW-2871), and BD/SEW. Three replicates each.

Project description:Acute respiratory distress syndrome (ARDS) is a catastrophic form of acute lung injury (ALI). The necessity for mechanical ventilation (MV) renders patients at risk for ventilator induced lung injury (VILI). Exposure to repetitive cyclic stretch (CS) and/or over-inflation exacerbates injury. Reducing tidal volume (VT) is the only therapeutic strategy shown to mitigate morbidity and mortality. Cyclic stretch has been shown to differentially regulate gene expression in part through the activation of mammalian mitogen-activated protein kinase (MAPK). Although these studies have shown both molecular and cellular alterations, no unifying hypothesis to explain MV-induced lung injury has emerged. In the current study, we hypothesized that coordinated expression of cyclic stretch (CS)-responsive genes relies on the presence of common CS-sensitive regulatory elements. To identify CS-responsive genes, we undertook a comparative examination of the gene expression profile of human bronchial epithelial airway (Beas-2B) cells in response to various injurious stimuli involved in the pathogenesis of acute lung injury (ALI)/Ventilator induced lung injury (VILI): cyclic stretch, tumor necrosis factor alpha (TNF-a), and lipopolysaccharide (LPS). Experiment Overall Design: Human Bronchial Epithelial Cells (Beas-B2) cells grown on silicon elastic plates coated with Type I collagen (Flexercell International, McKeesport, PA) were exposed to six regiments for 4 h: 1) control (static, [control]); 2) mechanical stretch (25 PKa, 30 cycles per min, [stretch]); 3) LPS (1 mcg/ml [LPS]); 4) TNF-Î± (20 ng/ml; [TNF]); 5) mechanical stretch plus LPS [LPS+S], and 6) mechanical stretch plus TNF-Î± [TNF+S]. Total RNA (duplicate experiments) was extracted using TRIZOL reagent (as per manufactures specifications) and purified using Qiagen mRNA purification Kit (as per manufacturers specifications). mRNA was hybridized to Affymetrix Human U133plus2.0 chips. Probe based analysis, background reduction, and quantile data normalization was performed in MeV 4.0 of TM4 using Robust Multi-array Average (RMA).

Project description:Background: Microvascular injury and increased vascular leakage are prominent features of the radiation-induced lung injury (RILI) which follows cancer–associated thoracic irradiation. The mechanisms of RILI are incompletely understood and therapeutic strategies to limit RILI are currently unavailable. We established a murine model of radiation pneumonitis in order to assess mechanism-based therapies for RILI-induced inflammation and vascular barrier dysfunction. Based on prior studies, we investigated the therapeutic potential of simvastatin as a vascular barrier protective agent in RILI. Methods: C57BL6/J mice receiving single dose exposure to 18, 20, 22, or 25 Gy, (n=10/group) were temporally assessed (4-12 weeks) for cellular and biochemical indices of injury present in both bronchoalveolar lavage (BAL) and lung tissues (cytokines, tyrosine nitrosylated proteins, leukocytes, extravasation of Evans blue dye or EBD, BAL albumin, histology). In specific experiments, irradiated mice (25Gy) received simvastatin (10 mg/kg) via intraperitoneal injection three times a week (pre and post irradiation) for 2- 6 weeks post irradiation. Results. Acute RILI evolved in a dose- and time-dependent fashion. Mice irradiated with 25Gy exhibited modest increases in BAL leukocytes but significant increases in BAL IL-6 (p=0.03) and TNF-a (p=0.01) at 4 weeks compared to controls. Increases in BAL nitrotyrosine content peaked at 6 weeks (p=0.03) and was accompanied by marked nitrotyrosine immunostaining in lung tissues. Indices of increase lung vascular permeability such as EBD extravasation, BAL protein and BAL albumin significantly increased over time beginning at 6 weeks (p>0.002 all) with histological evidence of severe edema formation and airway inflammation. Simvastatin- treated irradiated mice were noted to exhibit marked attenuation of vascular leak with significantly decreased BAL protein (p=0.01) and inflammatory cell infiltration (50% reduction). Conclusion: Simvastatin is a potentially important therapeutic strategy to limit RILI and may influence radiation associated morbidity and mortality. We used microarrays to detail the global programme of gene expression induced by radiation in Wild type and the protection of SIMVA

Project description:We have previously demonstrated that pre-B-cell colony enhancing factor (PBEF) ais a biomarker in sepsis and sepsis-induced acute lung injury (ALI) with genetic variants conferring ALI susceptibility118. In the current study, we explored the mechanistic participation of PBEF in ALI and ventilator-induced associated lung injury (VIALI). Initial in vitro studies and demonstrated rhPBEF aas a direct rat neutrophil chemotactic factor in vitro producing marked in vivo increases in BAL leukocytes (PMNs) in vivo following (intratracheal injection (,IT) in C57B6 mice. These latter changes were accompanied by increased BAL levels of the PMN chemoattractants (, KC and MIP2), and modest changes in lung vascular and but were not associated with significant increasesin alveolar permeability. We next explored the potential synergism between rhPBEF administration (IT) and a mechanical ventilation model of modest VILI lung injury (4 hours, 30 ml/kg tidal volume). We and observed dramatic synergistic increases in BAL PMNs, and both BAL protein and cytokine levels (IL-6, TNF-?, KC). Gene expression profiling Microarray analysis further supported a major role for PBEF in the induction of gene modules associated with ALI and VALI (NFkB pathway, leukocyte extravasation, apoptosis, toll receptor signaling). Finally, we exposed wild type and heterozygous PBEF+/- mice (targeted deletion of a single PBEF allele deletion) to a model of severe VILImechanical ventilation-induced lung injury (4 hours, 40 ml/kg tidal volume). PBEF+/- mice were significantly protected from VIALI-associated increases in BAL protein and BAL IL-6 levels and exhibited significantly reduced expression of ALI-associated gene expression modules. Together, these results indicate that PBEF is a key inflammatory mediator intimately involved in both the development and severity of ventilator-induced ALI. Keywords: We used microarrays to detail the global programme of gene expression induced by rhPBEF treatment and VALI.

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Non muscle myosin light chain kinase isoform is an attractive molecular target in acute inflammatory lung injury

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