Protein Concentration In Bronchoalveolar Lavage Fluid Research Articles

Linezolid Exerts Greater Bacterial Clearance but No Modification of Host Lung Gene Expression Profiling: A Mouse MRSA Pneumonia Model

BackgroundLinezolid (LZD) is beneficial to patients with MRSA pneumonia, but whether and how LZD influences global host lung immune responses at the mRNA level during MRSA-mediated pneumonia is still unknown.MethodsA lethal mouse model of MRSA pneumonia mediated by USA300 was employed to study the influence of LZD on survival, while the sublethal mouse model was used to examine the effect of LZD on bacterial clearance and lung gene expression during MRSA pneumonia. LZD (100mg/kg/day, IP) was given to C57Bl6 mice for three days. On Day 1 and Day 3 post infection, bronchoalveolar lavage fluid (BALF) protein concentration and levels of cytokines including IL6, TNFα, IL1β, Interferon-γ and IL17 were measured. In the sublethal model, left lungs were used to determine bacterial clearance and right lungs for whole-genome transcriptional profiling of lung immune responses.ResultsLZD therapy significantly improved survival and bacterial clearance. It also significantly decreased BALF protein concentration and levels of cytokines including IL6, IL1β, Interferon-γ and IL17. No significant gene expression changes in the mouse lungs were associated with LZD therapy.ConclusionLZD is beneficial to MRSA pneumonia, but it does not modulate host lung immune responses at the transcriptional level.

Systemic Administration of FC-77 Dampens Ischemia–Reperfusion-Induced Acute Lung Injury in Rats

Systemic administration of perfluorocarbons (PFCs) reportedly attenuates acute lung injury induced by acid aspiration and phorbol myristate acetate. However, the effects of PFCs on ischemia–reperfusion (IR)-induced lung injury have not been investigated. Typical acute lung injury was induced in rats by 60 min of ischemia and 60 min of reperfusion in isolated and perfused rat lung model. Rat lungs were randomly assigned to receive PBS (control), 1 % FC-77, IR only, or IR with different doses of FC-77 (0.1 %, 0.5 %, or 1 %). Subsequently, bronchoalveolar lavage fluid (BALF), perfusate, and lung tissues were collected to evaluate the degree of lung injury. IR caused a significant increase in the following parameters: pulmonary arterial pressure, capillary filtration coefficient, lung weight gain, lung weight/body weight ratio, wet/dry lung weight ratio, and protein concentration in BALF. TNF-α and cytokine-induced neutrophil chemoattractant-1 concentrations in perfusate samples and MDA concentration and MPO activities in lung tissues were also significantly increased. Histopathology showed increased septal thickness and neutrophil infiltration in the lung tissues. Furthermore, NF-κB activity was significantly increased in the lungs. However, pretreatment with 1 % FC-77 prior to IR significantly attenuated the increases in these parameters. In conclusion, our results suggest that systemic FC-77 administration had a protective effect on IR-induced acute lung injury. These protective mechanisms may have been mediated by the inhibition of NF-κB activation and attenuation of subsequent inflammatory response.

Effects of penehyclidine hydrochloride pretreatment on expression of β-arrestin-1 during sepsis-induced acute lung injury in mice

Objective To investigate the effects of penehyclidine hydrochloride (PHCD) pretreatment on β-arrestin-1 expression during sepsis-induced acute lung injury in mice.Methods Thirty female Kunming mice,weighing 18-20 g,were randomly divided into 3 groups (n =10 each):sham operation group (S group),sepsis group (CLP group) and PHCD group.Sepsis was induced by cecal ligation and puncture (CLP).In PHCD group,PHCD 0.45 mg/kg was injected intraperitoneally 1 h before CLP.The equal volume of normal saline was given instead in groups S and CLP.The mice were sacrificed at 12 h after CLP,bronchoalveolar lavage fluid (BALF) was collected for measurement of the total protein concentration,and the lungs were removed for determination of wet/dry lung weight ratio and expression of myosin light chain kinase (MLCK),vascular endothelial cadherin (VE-cad-herin) and β-arrestin-1 in lung tissues.The pathological changes of the lung were scored.Results Compared with group S,the lung injury score,wet/dry lung weight ratio and total protein concentration in BALF were significantly increased,MLCK expression was up-regulated and VE-cadherin expression was down-regulated in groups CLP and PHCD,β-arrestin-1 expression was down-regulated in group CLP and β-arrestin-1 expression was up-regulated in group PHCD (P ＜ 0.05 or 0.01).The lung injury score,wet/dry lung weight ratio,total protein concentration in BALF,and MLCK expression were significantly lower,while the expression of VE-cadherin and β-arrestin-1 was higher in PHCD group than in CLP group (P ＜ 0.05 or 0.01).Conclusion PHCD pretreatment can ameliorate acute lung injury through up-regulating β-arrestin-1 expression and reducing microvascular permeability in septic mice. Key words: Cholinergic antagonists ; Arrestins ; ; Respiratory distress syndrome, adult ; Sepsis

Post‐treatment with the heat shock protein 90 (hsp90) inhibitor, 17‐AAG, reduces pulmonary inflammation, hyper‐permeability and airway dysfunction associated with LPS‐induced acute lung injury (ALI) in mice.

Pre‐treatment with the heat shock protein 90 (hsp90) inhibitor, 17‐ AAG, reduces the magnitude of LPS‐induced ALI in mice. We now tested the hypothesis that post‐treatment with 17‐AAG would also reduce the magnitude of LPS‐induced ALI. 24h after the intratracheal instillation of vehicle or LPS (1.5mg/kg), mice received either vehicle or 17‐AAG (i.p. 10mg/kg). 48h later bronchoalveolar lavage fluid (BALF) was collected, and the number of cells and protein concentration were estimated as indicators of inflammation and permeability, respectively. In separate groups, lung capillary permeability was estimated by the Evans’ Blue Dye (EBD) method. LPS alone increased BALF cellularity (452±50 ×103cells/ml vs 33±2 ×103cells/ml in vehicle) and BALF protein concentration (204±5% from vehicle). 17‐AAG post‐treatment reduced the LPS‐induced BALF cellularity (140±32 ×103cells/ml) and protein concentration (119±18% from vehicle). Furthermore, LPS produced a 193±18% increase in EBD extravasation which was also significantly reduced to 135±27% in mice post‐treated with 17‐AAG. In additional mice, pulmonary function tests were performed. LPS caused a nearly 100% increase in airway resistance that was completely prevented by post‐treatment with 17‐AAG. These data strongly suggest important reparative actions of hsp90 inhibitors when administered after the LPS insult.

Therapeutic effects of inhaling aerosolized surfactant alone or with dexamethasone generated by a novel noninvasive apparatus on acute lung injury in rats

Pulmonary surfactant (PS) administration has been attempted for the treatment of adults with acute lung injury (ALI)/adult respiratory distress syndrome. Aerosolized surfactants inhaled by spontaneous breathing may be an effective method of surfactant-based therapies. Using a noninvasive apparatus, we evaluated the therapeutic effects of aerosolized PS alone or together with dexamethasone (Dex) on a rat model of ALI. Severe ALI was induced by intravenous injection of 20% oleic acid (0.2 mL/kg) into adult Sprague-Dawley rats. Animals were divided into eight groups: sham (n = 10); model (injury only, n = 10); normal saline (NS) aerosol driven by compressed air (air-NS, n = 13); PS aerosol driven by compressed air (air-PS, n = 13); NS aerosol driven by O2 (O2-NS, n = 13); PS aerosol driven by O2 (O2-PS, n = 13); Dex aerosol driven by O2 (O2-Dex, n = 13); and PS and Dex aerosol driven by O2 (O2-PS-Dex, n = 13). Blood gases, breathing rate, lung index, total protein, and proinflammatory cytokines (tumor necrosis factor-α, interleukin 1β, interleukin 6) in the bronchoalveolar lavage fluid (BALF), and lung histology were examined. Animals treated with air-PS for 20 minutes had significantly improved lung function, reduced pulmonary edema, decreased concentration of total protein and proinflammatory cytokines in BALF, ameliorated lung injury, and improved animal survival. In the O2-PS group, the breathing rates and lung injury scores were significantly lower than that of the air-PS group. In the O2-PS-Dex group, lung edema, total protein, and inflammatory cytokines in BALF were significantly reduced in comparison with the O2-PS group. Inhalation of aerosolized PS generated by the noninvasive apparatus could significantly reduce lung injury, while using oxygen line available in the clinical wards to generate PS aerosol is more convenient and adds further benefits. This method can also be used to deliver Dex and other therapeutic agents to ameliorate lung injury.

Intrapleural delivery of MSCs attenuates acute lung injury by paracrine/endocrine mechanism

Two different repair mechanisms of mesenchymal stem cells (MSCs) are suggested to participate in the repair of acute lung injury (ALI): (i) Cell engraftment mechanism, (ii) Paracrine/endocrine mechanism. However, the exact roles they play in the repair remain unclear. The aim of the study was to evaluate the role of paracrine/endocrine mechanism using a novel intrapleural delivery method of MSCs. Either 1 × 106 MSCs in 300 μl of PBS or 300 μl PBS alone were intrapleurally injected into rats with endotoxin-induced ALI. On days 1, 3 or 7 after injections, samples of lung tissues and bronchoalveolar lavage fluid (BALF) were collected from each rat for assessment of lung injury, biochemical analysis and histology. The distribution of MSCs was also traced by labelling the cells with 4′,6-diamidino-2-phenylindole dihydrochloride (DAPI). MSCs intrapleural injection significantly improved LPS-induced lung histopathology compared with PBS-treated group at day 3. There was also a significant decrease in total cell counts and protein concentration in BALF at day 7 in the MSCs -treated rats compared to PBS control group. Tracking the DAPI-marked MSCs showed that there were no exotic MSCs in the lung parenchyma. MSCs administration resulted in a down-regulation of pro-inflammatory response to endotoxin by reducing TNF-α both in the BALF and in the lung, while up-regulating the anti-inflammatory cytokine IL-10 in the lung. In conclusion, treatment with intrapleural MSCs administration markedly attenuates the severity of endotoxin-induced ALI. This role is mediated by paracrine/endocrine repair mechanism of MSCs rather than by the cell engraftment mechanism.

Host Platelets and, in Part, Neutrophils Mediate Lung Accumulation of Transfused UVB-Irradiated Human Platelets in a Mouse Model of Acute Lung Injury

We previously reported that ultraviolet light B (UVB)-treated human platelets (hPLTs) can cause acute lung injury (ALI) in a two-event SCID mouse model in which the predisposing event was Lipopolysaccharide (LPS) injection and the second event was infusion of UVB-treated hPLTs. To delineate contributions of host mouse platelets (mPLTs) and neutrophils in the pathogenesis of ALI in this mouse model, we depleted mPLTs or neutrophils and measured hPLT accumulation in the lung. We also assessed lung injury by protein content in bronchoalveolar lavage fluid (BALF). LPS injection followed by infusion of UVB-treated hPLTs resulted in sequestration of both mPLTs and hPLTs in the lungs of SCID mice, although the numbers of neutrophils in the lung were not significantly different from the control group. Depletion of mouse neutrophils caused only a mild reduction in UVB-hPLTs accumulation in the lungs and a mild reduction in protein content in BALF. In comparison, depletion of mPLTs almost completely abolished hPLTs accumulation in the lung and significantly reduced protein content in BALF. UVB-treated hPLTs bound to host mPLTs, but did not bind to neutrophils in the lung. Aspirin treatment of hPLTs in vitro abolished hPLT accumulation in the lung and protected mice from lung injury. Our data indicate that host mPLTs accumulated in the lungs in response to an inflammatory challenge and subsequently mediated the attachment of transfused UVB-hPLTs. Neutrophils also recruited a small percentage of platelets to the lung. These findings may help develop therapeutic strategies for ALI which could potentially result from transfusion of UV illuminated platelets.

Role of neutrophil elastase in lung injury induced by burn–blast combined injury in rats

ObjectiveNeutrophil elastase (NE) takes part in the pathogenesis of acute lung injury. However, its role in lung injury of burn–blast combined injury is unclear. Our objective was to assess the role of NE, and effect of sivelestat, a specific NE inhibitor, in lung injury induced by burn–blast combined injury in rats. MethodsOne hundred and sixty male Sprague-Dawley rats were randomly subjected to burn–blast combined injury (BB) group, burn–blast combined injury plus sivelestat treatment (S) group or control (C) group. Blood gas, protein concentration and NE activity in bronchoalveolar lavage fluid (BALF), pulmonary myeloperoxidase (MPO) activity, serum concentrations of TNF-α and IL-8, etc. were investigated from 0h to 7d post-injury. ResultsIn BB group, PaO2 decreased, while NE activity in BALF, total protein concentration in BALF, pulmonary MPO activity and W/D ratio, serum concentrations of TNF-α and IL-8 increased with neutrophil infiltration, progressive bleeding and pulmonary oedema. Compared with BB group, sivelestat treatment decreased the NE activity and ameliorated the above indexes. ConclusionSivelestat, exerts a protective effect in lung injury after burn–blast combined injury through inhibiting NE activity to decrease pulmonary vascular permeability, neutrophil sequestration, and production of TNF-α and IL-8.

Effect of dexamethasone on MKP-1 expression in lung tissues in rats with lipopolysaccharide-induced acute lung injury

Objective To investigate the effect of dexamethasone on mitogen-activated protein kinase phosphatase-1 (MKP-1) expression in lung tissues in rats with lipopolysaccharide (LPS)-induced acute lung injury (ALI).Methods Fifty-four male SD rats weighing 180-230 g were randomly divided into 3 groups:control group (group C,n =6) ;ALI group ( n =24) and dexamethasone group (group D,n =24).LPS 5 mg/kg was injected via tail vein in groups ALI and D,while the equal volume of normal saline was given in group C.Dexamethasone 6 mg/kg was injected intraperitoneally at 30 min before LPS administration in group D.Eight rats in each group were sacrificed at 1 h after normal saline administration (T1) in group C and at 1,3,and 6 h after LPS administration (T1-3 ) in groups ALI and D.The lung tissues were then removed for determination of the expression of phosphorylated p38 mitogen-activated protein kinase (p-p38MAPK) and MKP-1.The concentrations of albumin and TNF-α in bronchoalveolar lavage fluid (BALF) were detected and histopathological changes were observed at T3 ·Another 32 SD rats weighing 180-230 g were randomly divided into 2 groups ( n =16 each):group ALI1 and group D1.The rats were treated as the method mentioned above and the 48 h survival condition was observed.Results Compared with group C, the concentrations of protein and TNF-α in BALF were significantly increased,p-p38MAKP expression was up-regulated at T1.3,and MKP-1 expression was down-regulated at T2,3 in group ALI,and TNF-α concentration in BALF was significantly increased and the expression of p-p38MAKP and MKP-1 was up-regulated at T1-3 in group D ( P ＜ 0.05).Compared with group ALI,the concentrations of protein and TNF-α in BALF were significantly decreased,p-p38MAKP expression was down-regulated and MKP-1 expression was up-reg-ulated at T1-3 ( P ＜ 0.05 ),and the pathological damage was attenuated in group D.The 48 h survival rate was significantly higher in group D1 than in group ALI1 ( P ＜ 0.05).Conclusion The mechanism by which dexamethasone attenuates the ALI induced by LPS may be related to up-regulation of MKP-1,inhibition of phosphorylation of p38MAPK and decrease in inflammatory response. Key words: Dexamethasone; Respiratory distress syndrome, adult; Endotoxins; Mitogen-activated protein kinase phosphatase -1; Lung

Hypercapnic acidosis attenuates reperfusion injury in isolated and perfused rat lungs*

Although ischemia-reperfusion injury is a major determinant of primary graft dysfunction after lung transplantation, an approach to extend preoperative lung preservation to postoperative protection has not yet been defined. The purpose of this study was to determine the protective effects of and the signal pathway regulated by hypercapnic acidosis in ischemia-reperfusion-induced lung injury. Animal study. Animal care facility procedure room in a medical center. Adult male Sprague-Dawley rats. Lung injury was induced in a clinically relevant ex vivo animal model. Animals were divided into a control group (FICO(2), 5%; n = 6), ischemia-reperfusion group (FICO(2), 5%; n = 6), and hypercapnic acidosis (ischemia-reperfusion + hypercapnic acidosis) group (FICO(2), 10%; n = 6). Ischemia-reperfusion caused significant increases in alveolar lavage and perfusate tumor necrosis factor-α, inflammatory cell infiltration, lung tissue malondialdehyde, bronchoalveolar lavage fluid protein concentration and lactate dehydrogenase activity, lung weight gain, and infiltration coefficient. Ventilation with 10% CO(2) significantly suppressed the inflammatory response and attenuated lung ischemia-reperfusion injury. Our results also showed that hypercapnic acidosis significantly inhibited the ischemia-reperfusion-induced phosphorylation and nuclear translocation of nuclear factor-κB. This was associated with elevation of inhibitor of nuclear factor-κB-α level and reduced IκB kinase-β phosphorylation, suggesting a suppression of IκB kinase and thus IκB-α activation. Hypercapnic acidosis may attenuate lung ischemia-reperfusion injury by suppressing the activation of the IκB kinase-nuclear factor-κB pathway.

Role of heme oxygenase-1 in dachengqitang ameliorating lipopolysaccharide-induced acute lung injury in mice

To explore the role of heme oxygenase (HO)-1 experimental system in dachengqitang (DD) ameliorating ALI induced by lipopolysaccharide (LPS) in mice. Seventy-five male Kunming mice were randomly divided into control group (normal saline was instilled intratracheally(50 microL/per mouse), LPS group (LPS was instilled intratracheally to replicate ALI model), DD + LPS group, DD + LPS + ZnPP (ZnPP, HO-1 specific inhibitor) group and the DD group. Mice were killed at 6 h after administration. Lung indexes were tested; lung histomorphological changes were observed under microscope, and neutrophils (PMN) number and protein content of bronchoalveolar lavage fluid (BALF) were measured; HO-1 mRNA and protein expression in lung tissue were detected by RT-PCR and Western blot. The results showed that intratracheal instillation of LPS in mice can cause significant morphological changes in lung tissue. Both PMN numbers and protein content in BALF were increased. meanwhile the expressions of HO-1 mRNA and protein in lung tissue were increased. Pretreated with DD and then intratracheally instillated LPS coulde ameliorat lung tissue injury, reduced PMN BALF number and protein content, but increase HO-1 mRNA and protein expression in the lung tissue when compared with LPS. HO-1 inhibitor ZnPP coulde inhibite the ameliorative effect of DD. The results suggest that the ameliorative effect of DD on ALI induced by LPS in mice were related with upregulation HO-1 mRNA and protein.

Metformin attenuates ventilator-induced lung injury.

IntroductionDiabetic patients may develop acute lung injury less often than non-diabetics; a fact that could be partially ascribed to the usage of antidiabetic drugs, including metformin. Metformin exhibits pleiotropic properties which make it potentially beneficial against lung injury. We hypothesized that pretreatment with metformin preserves alveolar capillary permeability and, thus, prevents ventilator-induced lung injury.MethodsTwenty-four rabbits were randomly assigned to pretreatment with metformin (250 mg/Kg body weight/day per os) or no medication for two days. Explanted lungs were perfused at constant flow rate (300 mL/min) and ventilated with injurious (peak airway pressure 23 cmH2O, tidal volume ≈17 mL/Kg) or protective (peak airway pressure 11 cmH2O, tidal volume ≈7 mL/Kg) settings for 1 hour. Alveolar capillary permeability was assessed by ultrafiltration coefficient, total protein concentration in bronchoalveolar lavage fluid (BALF) and angiotensin-converting enzyme (ACE) activity in BALF.ResultsHigh-pressure ventilation of the ex-vivo lung preparation resulted in increased microvascular permeability, edema formation and microhemorrhage compared to protective ventilation. Compared to no medication, pretreatment with metformin was associated with a 2.9-fold reduction in ultrafiltration coefficient, a 2.5-fold reduction in pulmonary edema formation, lower protein concentration in BALF, lower ACE activity in BALF, and fewer histological lesions upon challenge of the lung preparation with injurious ventilation. In contrast, no differences regarding pulmonary artery pressure and BALF total cell number were noted. Administration of metformin did not impact on outcomes of lungs subjected to protective ventilation.ConclusionsPretreatment with metformin preserves alveolar capillary permeability and, thus, decreases the severity of ventilator-induced lung injury in this model.

Analysis of Bronchoalveolar Lavage Fluid Adhering to Lung Surfactant

Nickel oxide with two different particle sizes, micron size (NiO) and submicron size (nNiOm), as well as crystalline silica as a positive control and titanium dioxide as a negative control, were intratracheally instilled in rats and the phospholipid concentration and the protein concentration and surface tension of bronchoalveolar lavage fluid (BALF), which are used in surfactant assessment, were measured to see if they could be effective biomarkers in toxicity assessment. The results showed that the NiO instilled group showed no significant difference compared to the control group throughout the observation period. In contrast, a significant difference was found in the nNiOm instilled group compared to the control group throughout the observation period. Moreover, a significant difference was found in the crystalline silica instilled group for each measurement compared to the control group while for the titanium dioxide group, almost no significant difference was found. These results indicate that submicronsized particles of nickel oxide with smaller median diameters potentially have a stronger biological effect than micron size particles. They also indicate that screening can be done by measuring the phospholipid concentration and the protein concentration and surface tension of BALF.

Ubiquitin and Stromal Cell-Derived Factor-1α in Bronchoalveolar Lavage Fluid After Burn and Inhalation Injury

The objective of the study was to determine whether the CXC chemokine receptor (CXCR) 4 ligands ubiquitin and stromal cell-derived factor (SDF)-1α are detectable in bronchoalveolar lavage fluid (BALF) after burn and inhalation injury and whether their concentrations in BALF are associated with injury severity, physiological variables, or clinical outcomes. BALF was obtained on hospital admission from 51 patients (48 ± 18 years) with burn (TBSA: 23 ± 24%) and inhalation injury (controls: 10 healthy volunteers, 42 ± 8 years). BALF was analyzed for total protein and for ubiquitin and SDF-1α by enzyme-linked immunosorbent assay. Ubiquitin/SDF-1α levels were normalized to total BALF protein content. The extent of inhalation injury was determined during bronchoscopy using a standardized scoring system. Percent TBSA, Baux scores, revised Baux scores, and clinical variables were documented. Ubiquitin and SDF-1α were detectable in 40% of normal BALF specimens. After injury, ubiquitin was detectable in 90% (P < .01 vs control) and SDF-1α in 10% of the specimens (P < .05 vs control). While SDF-1α levels were reduced in patients (P < .01), ubiquitin levels were increased (P < .01). Ubiquitin concentrations correlated inversely with grade of inhalation injury, revised Baux scores, and resuscitation fluid requirements (Spearman correlation coefficients [r]: -.3, -.33, and -.45, respectively). Ubiquitin levels correlated positively with arterial oxygenation at the time of bronchoscopy (r: .35). BALF levels of CXCR4 agonists are differentially regulated after burn and inhalation injury. Increases in BALF ubiquitin after inhalation injury may maintain CXCR4-mediated lung protection and repair processes. The finding that BALF ubiquitin decreased with higher grades of inhalation injury may provide a biological correlate for an insufficient local inflammatory response after severe inhalation injury.

Bupleurum chinense DC polysaccharides attenuates lipopolysaccharide-induced acute lung injury in mice

Bupleurum chinense DC had hepato-protective, anti-inflammatory, antipyretic, analgesic, and immunomodulatory effect in traditional Chinese medicine. This study was to determine whether the crude polysaccharides isolated from the roots of Bupleurum chinense DC (BCPs) attenuated lipopolysaccharide (LPS)-induced acute lung injury in mice. Mice were challenged with LPS intratracheally 2 h before BCPs (20, 40 and 80 mg/kg) administration. The bronchoalveolar lavage fluid (BALF) was collected 24 h after LPS challenge. Treatment with BCPs reduced lung wet-to-dry weight ratio. The elevated number of total cells and protein concentration in BALF was reduced. The increased level of myeloperoxidase (MPO), tumor necrosis factor-α (TNF-α) in BALF, and serum nitric oxide (NO) were also inhibited. BCPs significantly attenuated lung injury with improved lung morphology and reduced complement deposition. These results suggested that the effect of BCPs against ALI might be related with its inhibitory effect on excessive activation of complement and on the production of proinflammatory mediators.

Direct evidence that GM-CSF inhalation improves lung clearance in pulmonary alveolar proteinosis

Autoimmune pulmonary alveolar proteinosis (aPAP) is caused by granulocyte/macrophage-colony stimulating factor (GM-CSF) autoantibodies in the lung. Previously, we reported that GM-CSF inhalation therapy improved alveolar-arterial oxygen difference and serum biomarkers of disease severity in these patients. It is plausible that inhaled GM-CSF improves the dysfunction of alveolar macrophages and promotes the clearance of the surfactant. However, effect of the therapy on components in bronchoalveolar lavage fluid (BALF) remains unclear. To figure out changes in surfactant clearance during GM-CSF inhalation therapy. We performed retrospective analyses of BALF obtained under a standardized protocol from the same bronchus in each of 19 aPAP patients before and after GM-CSF inhalation therapy (ISRCTN18931678, JMA-IIA00013; total dose 10.5-21 mg, duration 12-24 weeks). For evaluation, the participants were divided into two groups, high responders with improvement in alveolar-arterial oxygen difference ≥13 mmHg (n = 10) and low responders with that < 13 mmHg (n = 9). Counts of both total cells and alveolar macrophages in BALF did not increase during the therapy. However, total protein and surfactant protein-A (SP-A) were significantly decreased in high responders, but not in low responders, suggesting that clearance of surfactant materials is correlated with the efficacy of the therapy. Among 94 biomarkers screened in bronchoalveolar lavage fluid, we found that the concentration of interleukin-17 and cancer antigen-125 were significantly increased after GM-CSF inhalation treatment. GM-CSF inhalation decreased the concentration of total protein and SP-A in BALF, and increase interleukin-17 and cancer antigen-125 in improved lung of autoimmune pulmonary alveolar proteinosis.

17β-Estradiol Protects the Lung against Acute Injury: Possible Mediation by Vasoactive Intestinal Polypeptide

Beyond their classical role as a class of female sex hormones, estrogens (e.g. 17β-estradiol) exert important biological actions, both protective and undesirable. We have investigated the ability of estradiol to protect the lung in three models of acute injury induced by 1) oxidant stress due to the herbicide paraquat; 2) excitotoxicity, caused by glutamate agonist N-methyl-d-aspartate; and 3) acute alveolar anoxia. We also assessed the role of estrogen receptors (ER) ERα and ERβ and the neuropeptide vasoactive intestinal peptide (VIP) in mediating this protection. Isolated guinea pig or rat lungs were perfused in situ at constant flow and mechanically ventilated. The onset and severity of lung injury were monitored by increases in pulmonary arterial and airway pressures, wet/dry lung weight ratio, and bronchoalveolar lavage fluid protein content. Estradiol was infused into the pulmonary circulation, beginning 10 min before induction of injury and continued for 60-90 min. Lung injury was marked by significant increases in the above measurements, with paraquat producing the most severe, and excitotoxicity the least severe, injury. Estradiol significantly attenuated the injury in each model. Both ER were constitutively expressed and immunohistochemically demonstrable in normal lung, and their selective agonists reduced anoxic injury, the only model in which they were tested. As it protected against injury, estradiol rapidly and significantly stimulated VIP mRNA expression in rat lung. Estradiol attenuated acute lung injury in three experimental models while stimulating VIP gene expression, a known mechanism of lung protection. The up-regulated VIP expression could have partially mediated the protection by estrogen.

Lysophosphatidic acid receptor 1 modulates lipopolysaccharide-induced inflammation in alveolar epithelial cells and murine lungs

Lysophosphatidic acid (LPA), a bioactive phospholipid, plays an important role in lung inflammation by inducing the release of chemokines and lipid mediators. Our previous studies have shown that LPA induces the secretion of interleukin-8 and prostaglandin E(2) in lung epithelial cells. Here, we demonstrate that LPA receptors contribute to lipopolysaccharide (LPS)-induced inflammation. Pretreatment with LPA receptor antagonist Ki16425 or downregulation of LPA receptor 1 (LPA(1)) by small-interfering RNA (siRNA) attenuated LPS-induced phosphorylation of p38 MAPK, I-κB kinase, and I-κB in MLE12 epithelial cells. In addition, the blocking of LPA(1) also suppressed LPS-induced IL-6 production. Furthermore, LPS treatment promoted interaction between LPA(1) and CD14, a LPS coreceptor, in a time- and dose-dependent manner. Disruption of lipid rafts attenuated the interaction between LPA(1) and CD14. Mice challenged with LPS increased plasma LPA levels and enhanced expression of LPA receptors in lung tissues. To further investigate the role of LPA receptors in LPS-induced inflammation, wild-type, or LPA(1)-deficient mice, or wild-type mice pretreated with Ki16425 were intratracheally challenged with LPS for 24 h. Knock down or inhibition of LPA(1) decreased LPS-induced IL-6 release in bronchoalveolar lavage (BAL) fluids and infiltration of cells into alveolar space compared with wild-type mice. However, no significant differences in total protein concentration in BAL fluids were observed. These results showed that knock down or inhibition of LPA(1) offered significant protection against LPS-induced lung inflammation but not against pulmonary leak as observed in the murine model for lung injury.

The changes of the ratio of angiopoietin-2 to angiopoietin-1 in the acute lung injury induced by phosgene in rats

To observe the relationship between the indicators of lung injury and the ratio of angiopoietin-2 (ang-2) to angiopoietin-1 (ang-1) in serum of rats with acute lung injury induced by phosgene. Eighty four adult male SD rats were randomly divided into 13 phosgene groups and 1 control group. Control group was exposed to fresh air for 5 minutes; the phosgene groups were exposed to phosgene (100% purity of 8.33 mg/L phosgene ) for 5 minutes. At different time points after exposure, the wet/dry weight ratio of mouse lungs was examined, the levels of ang-1 and ang-2 in serum of rats were detected with ELISA assay, and the white blood cell count and total protein levels in bronchoalveolar lavage fluid (BALF) of rats were measured. In 48 h after exposure,the serum ang-2, lung wet/dry weight ratio, BALF white blood cell count, protein concentration tended to increase with time, and the serum ang-1 tended to decrease with time. The ratios of ang-2 to ang-1 at 6, 8, 10, 12, 14, 16, 18, 20, 22, 24 and 48 h after exposure in phosgene groups were significantly higher than that in control group (P < 0.05 or P < 0.01). There were the positive correlations between ang-2 and lung wet/dry ratio, BALF white blood cell count or protein concentration (P < 0.01). There were the negative correlations between ang-1 and lung wet/dry ratio or BALF white blood cell count (P < 0.01). There were the positive correlations between the ratio of ang-2 to ang-1 and lung wet/dry ratio, BALF white blood cell count or protein concentration (P < 0.01). After exposure of rats to phosgene, there is a positive correlation between the ratio of ang-2 to ang-1 and lung injury indicators, which may be an early indicator of the severity of phosgene-induced acute lung injury.

Intensive Insulin Treatment Attenuates Burn-Initiated Acute Lung Injury in Rats: Role of the Protective Endothelium

Nonmetabolic effects of intensive insulin therapy in critically ill patients have been reported, but the underlying mechanisms are unclear. This study was designed to test the hypothesis that intensive insulin treatment would attenuate burn-induced acute lung injury by protecting the pulmonary microvascular endothelium. The rat model of burn injury was achieved by exposure to 92°C water for 18 seconds. The rats were randomly allocated into the sham, burn/normal saline (NS), and burn/intensive insulin treatment groups. Blood glucose level was maintained between 5 and 7 mmol/L in rats in the burn/intensive insulin treatment group. Pulmonary injury was assessed by hematoxylin and eosin staining, scanning electron microscopy, bronchoalveolar lavage fluid protein concentrations, the lung wet:dry weight ratio, and lung myeloperoxidase activity. Pulmonary microvascular endothelial cells were examined by transmission electron microscopy. Western blotting was used to determine the protein expression of caspase-3. Intensive insulin treatment markedly attenuated the acute lung injury, revealed by improvements in histological features and significant decreases in bronchoalveolar lavage fluid protein concentrations, pulmonary wet:dry weight ratio, and myeloperoxidase activity at 12 hours after injury (P < .05 or P < .01 vs burn/NS). Moreover, the injured pulmonary microvascular endothelial cells showed significant improvements, whereas caspase-3 was markedly downregulated in the burn/intensive insulin treatment group when compared with the burn/NS group. Overall, intensive insulin treatment efficiently attenuated pulmonary microvascular endothelial cell dysfunction, decreased cell apoptosis, and inhibited acute lung injury after a burn. These findings may be useful in preventing organ failure after burn injury.