Adenovirus-delivered angiopoietin-1 treatment for phosgene-induced acute lung injury

Abstract

Context: Exposure to phosgene can result in an acute lung injury, leading to pulmonary edema and even death. Angiopoietin-1 (Ang1) is a critical factor for vascular stabilization due to its ability to reduce endothelial permeability and inflammation.

Objective: In this study, the histopathological changes of the lungs after exposure to phosgene and the effect of Ang1 treatment were examined.

Materials and methods: Rats were exposed to phosgene gas at 8.33?g/m³ for 5?min. Ang1 overexpressing rats were established by an intravenous injection of adenovirus-Ang1 (Ad/Ang1). The histological changes of the lung were examined by Haematoxylin-Eosin (H&E) staining and fluorescence microscopy. The inferior lobe was used for the determination of the ratio of wet weight to dry weight of the lung. The concentration of cytokines in the serum and bronchoalveolar lavage fluid was determined by enzyme-linked immunosorbent assay.

Results: The pathological analysis showed signs of inflammation and edema, evident from a significant increase in the number of leukocytes in bronchoalveolar lavage fluid and the ratio of wet to dry weight of the lungs. The lung injury induced by phosgene was markedly reduced after the injection of Ad/Ang1. The increase of IL-1β and IL-17 and decrease of vascular endothelial growth factor in the serum and bronchoalveolar lavage fluid of phosgene-exposed animals were abolished by the administration of Ad/Ang1.

Discussion and conclusions: Ang1 has the beneficial effects on phosgene-induced lung injury. The adenovirus-delivered Ang1 may have the potential as a novel approach for the treatment of the acute lung injury caused by phosgene gas inhalation in humans.     

Mesenchymal stem cell-derived exosomes attenuate phosgene-induced acute lung injury in rats

Objective: We have previously found that mesenchymal stem cell (MSC) therapy can ameliorate phosgene-induced acute lung injury (ALI). Moreover, exosomes can be used as a cell-free alternative therapy. In the present study, we aimed to assess the effect of MSC-derived exosomes on phosgene-induced ALI.

Methods: MSC-derived exosomes were isolated from MSCs through ultracentrifugation. Sprague-Dawley (SD) rats were exposed to phosgene at 8.33?g/m³ for 5?min. MSC-derived exosomes were intratracheally administered and rats were sacrificed at the time points of 6, 24 and 48?h.

Results: Compared with the phosgene group, MSC-derived exosomes reversed respiratory function alterations, showing increased levels of TV, PIF, PEF and EF50 as well as decreased levels of RI and EEP. Furthermore, MSC-derived exosomes improved pathological alterations and reduced wet-to-dry ratio and total protein content in BALF. MSC-derived exosomes reduced the levels of TNF-α, IL-1β and IL-6 and increased the IL-10 level in BALF and plasma. MSC-derived exosomes suppressed the MMP-9 level and increased the SP-C level.

Conclusions: MSC-derived exosomes exerted beneficial effects on phosgene-induced ALI via modulating inflammation, inhibiting MMP-9 synthesis and elevating SP-C level.     

Bone marrow-derived mesenchymal stem cells attenuate phosgene-induced acute lung injury in rats

Abstract

Accidental phosgene exposure could result in acute lung injury (ALI), effective therapy is needed for the patients with phosgene-induced ALI. As a type of cells with therapeutic potential, mesenchymal stem cells (MSCs) have been showed its efficacy in multiple diseases. Here, we assessed the therapeutic potential of MSCs in phosgene-induced ALI and explored the related mechanisms. After isolation and characterization of rat bone marrow MSCs (BMMSCs), we transplanted BMMSCs into the rats exposed to phosgene and observed significant improvement on the lung wet-to-dry ratio and partial oxygen pressure (PaO₂) at 6, 24, 48?h after phosgene exposure. Histological analyses revealed reduced sign of pathological changes in the lungs. Reduced level of pro-inflammatory tumor necrosis factor α and increased level of anti-inflammatory factor interleukin-10 were found in both bronchoalveolar lavage and plasma. Significant increased expression of epithelial cell marker AQP5 and SP-C was also found in the lung tissue. In conclusion, treatment with MSC markedly decreases the severity of phosgene-induced ALI in rats, and these protection effects were closely related to the pulmonary air blood barrier repairment and inflammatory reaction regulation.     

Correlation Between sPLA2-llA and Phosgene-Induced Rat Acute Lung Injury

Secreted phospholipase A₂ of group IIA (sPLA₂-IIA) has been involved in a variety of inflammatory diseases, including acute lung injury. However, the specific role of sPLA₂-IIA in phosgene-induced acute lung injury remains unidentified. The aim of the present study was to investigate the correlation between sPLA₂-IIA activity and the severity of phosgene-induced acute lung injury. Adult male rats were randomly exposed to either normal room air (control group) or a concentration of 400 ppm phosgene (phosgene-exposed group) for there are 5 phosgene-exposed groups altogether. For the time points of 1, 3, 6, 12 and 24 h post-exposure, one phosgene-exposed group was sacrificed at each time point. The severity of acute lung injury was assessed by Pa_O2/F_IO2 ratio, wet-to-dry lung-weight ratio, and bronchoalveolar lavage (BAL) fluid protein concentration. sPLA₂-IIA activity in BAL fluid markedly increased between 1 h and 12 h after phosgene exposure, and reached its highest level at 6 h. Moreover, the trend of this elevation correlated well with the severity of lung injury. These results indicate that sPLA₂-IIA probably participates in phosgene-induced acute lung injury.     

The temporal profile of cytokines in the bronchoalveolar lavage fluid in mice exposed to the industrial gas phosgene

Diagnosis of an exposure to airborne toxicants can be problematic. Phosgene is used widely in industry for the production of many synthetic products, such as polyfoam rubber, plastics, and dyes. Although nearly 100% of the gas is consumed during processing, there is the potential problem of accidental or even intentional exposure to this irritant/choking agent. Exposure to phosgene has been known to cause latent life-threatening pulmonary edema. A major problem is that there is a clinical latency phase from 3 to 24 h in people before irreversible acute lung injury occurs. Assessment of markers of acute lung injury after a suspected exposure would be useful in developing rational treatment strategies. These experiments were designed to assess bronchoalveolar lavage fluid (BALF) for the presence of the early markers of exposure to phosgene in mice from 1 to 72 h after exposure. Separate groups of 40 CD-1 male mice (Crl:CD-1(ICR)BR) weighing 29 +/- 1 g were exposed whole-body to either air or a concentration x time (c x t) amount of 32 mg/m(3) (8 ppm) phosgene for 20 min (640 mg x min/m(3)). BALF from air- or phosgene-exposed mice was taken at 1, 4, 8, 12, 24, 48, and 72 h postexposure. After euthanasia, the trachea was excised, and 800 micro l saline was instilled into the lungs and washed 5x. BALF was assessed for interleukin (IL)-4, IL-6, tumor necrosis factor (TNF) alpha, IL-1alpha, macrophage inflammatory protein (MIP)-2, and IL-10. At 4 h postexposure, IL-6 was 15-fold higher for phosgene-exposed mice than for the time-matched air-exposed control group. At 8 and 12 h, IL-6, IL-1beta, MIP-2, and IL-10 were significantly higher in phosgene-exposed mice than in time-matched air-exposed controls, p < or = 0.05 to p < or = 0.001, whereas TNF alpha reached peak significance from 24 to 72 h. IL-4 was significantly lower in the phosgene-exposed mice than in the air-exposed mice from 4 to 8 h after exposure. These data show that BALF is an important tool in assessing pro- and anti-inflammatory markers of phosgene-induced acute lung injury and that knowledge of these temporal changes may allow for timely treatment strategies to be applied.     

The Temporal Profile of Cytokines in the Bronchoalveolar Lavage Fluid in Mice Exposed to the Industrial Gas Phosgene

Diagnosis of an exposure to airborne toxicants can be problematic. Phosgene is used widely in industry for the production of many synthetic products, such as polyfoam rubber, plastics, and dyes. Although nearly 100% of the gas is consumed during processing, there is the potential problem of accidental or even intentional exposure to this irritant/choking agent. Exposure to phosgene has been known to cause latent life-threatening pulmonary edema. A major problem is that there is a clinical latency phase from 3 to 24 h in people before irreversible acute lung injury occurs. Assessment of markers of acute lung injury after a suspected exposure would be useful in developing rational treatment strategies. These experiments were designed to assess bronchoalveolar lavage fluid (BALF) for the presence of the early markers of exposure to phosgene in mice from 1 to 72 h after exposure. Separate groups of 40 CD-1 male mice (Crl:CD-1(ICR)BR) weighing 29 ± 1 g were exposed whole-body to either air or a concentration × time (c × t) amount of 32 mg/m 3 (8 ppm) phosgene for 20 min (640 mg·min/m 3) . BALF from air- or phosgene-exposed mice was taken at 1, 4, 8, 12, 24, 48, and 72 h postexposure. After euthanasia, the trachea was excised, and 800 µl saline was instilled into the lungs and washed 5 ×. BALF was assessed for interleukin (IL)-4, IL-6, tumor necrosis factor (TNF)α, IL-1α, macrophage inflammatory protein (MIP)-2, and IL-10. At 4 h postexposure, IL-6 was 15-fold higher for phosgene-exposed mice than for the time-matched air-exposed control group. At 8 and 12 h, IL-6, IL-1β, MIP-2, and IL-10 were significantly higher in phosgene-exposed mice than in time-matched air-exposed controls, p ≤ .05 to p ≤ .001, whereas TNFα reached peak significance from 24 to 72 h. IL-4 was significantly lower in the phosgene-exposed mice than in the air-exposed mice from 4 to 8 h after exposure. These data show that BALF is an important tool in assessing pro- and anti-inflammatory markers of phosgene-induced acute lung injury and that knowledge of these temporal changes may allow for timely treatment strategies to be applied.     

PM2.5致大鼠肺损伤模型中肺巨噬细胞NLRP3 炎性小体活化研究

摘要： 目的 探讨肺巨噬细胞NLRP3炎性小体活化在大气细颗粒物 （PM2.5） 所致肺炎症损伤中的作用。方法 采用中流量采样器收集PM2.5颗粒物制成混悬液， 经气管滴注给予高、 中、 低剂量 （分别为15、 10、 5 mg/kg） 制成大鼠肺损伤模型， 3 d后麻醉动物进行肺泡灌洗， 收集支气管肺泡灌洗液 （BALF） 中的巨噬细胞， 中性红法测定其吞噬功能， 并采用免疫荧光双染色观察肺巨噬细胞内NLRP3的表达； 处死大鼠解剖取肺组织， HE染色观察肺损伤严重程度并评分， 免疫组化法检测肺组织NLRP3表达， ELISA法测定肺组织内IL-18、 IL-1β及Caspase-1的表达情况。结果 大鼠经气管滴注PM2.5染毒后， BALF内巨噬细胞吞噬功能下降。实验组大鼠肺损伤明显， 表现为间质性肺炎； 肺泡间隔明显增宽， 部分肺泡壁断裂， 尤以高剂量组表现明显； 各实验组大鼠的肺组织病理学评分均明显高于对照组 （均 P＜0.05）。低、 中、 高剂量组大鼠肺组织内NLRP3表达均高于对照组。肺组织内IL-18、 IL-1β及Caspase-1的表达不同程度上调。结论 大鼠气管滴注PM2.5引起的肺损伤和炎症反应与肺巨噬细胞内NLRP3炎症小体的活化有关。     

Mesenchymal stem cells overexpressing Ang1 attenuates phosgene-induced acute lung injury in rats

Abstract

Phosgene-induced acute lung injury (P-ALI) is characterized by inflammation and effective treatments are lacking. Angiopoietin-1 (Ang1) has the beneficial effects on P-ALI. Mesenchymal stem cells (MSCs) have the potential for re-epithelization and recovery in lung injury. Thus, we hypothesized that Ang1 expressing MSCs would have beneficial effects on P-ALI. Here, an Ang1 expressing lentiviral vector was constructed and infected into rat bone marrow MSCs. Histological analyses revealed significant pathological improvements especially after treatment with MSCs in the rats exposed to phosgene. Ang1 facilitated the homing of MSCs to injured lung tissue and significantly increased expression of both epithelial cell marker Aquaporin-5 (AQP5) and surfactant protein-C (SPC) in the lung tissues. Moreover, MSCs-Ang1 reduced level of pro-inflammatory cytokines TGF-β1 and IL-1β and increased the expression of the anti-inflammatory cytokine IL-10 in the serum and bronchoalveolar lavage fluid (BALF) of P-ALI rats. In conclusion, our results suggest that Ang1 may improve the therapeutic potential of MSCs for P-ALI treatment.     

NecroX-5 alleviate lipopolysaccharide-induced acute respiratory distress syndrome by inhibiting TXNIP/NLRP3 and NF-κB

The activation of NLRP3 inflammasome and NF-κB pathway, associating with oxidative stress, have been implicated in the development of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). NecroX-5 has been reported to exhibit the effects of anti-oxidation and anti-stress in various diseases. However, the role of NecroX-5 in ALI has not been explicitly demonstrated. The aim of this study was to explore the therapeutic effects and potential mechanism action of NecroX-5 on ALI. Here, we found that NecroX-5 pretreatment dramatically diminished the levels of IL-1β, IL-18 and ROS in in RAW264.7 cells challenged with LPS and ATP. Furthermore, NecroX-5 suppressed the activation of NLRP3 inflammasome and NF-κB signal pathway. In addition, NecroX-5 also inhibited the thioredoxin-interacting protein (TXNIP) expression. In vivo, NecroX-5 reduced the LPS-induced lung histopathological injury, the number of TUNEL-positive cells, lung wet/dry (W/D) ratio, levels of total protein and inflammatory cytokines in the bronchoalveolar lavage fluid (BALF) in mice. Additionally, LPS-induced upregulation of myeloperoxidase (MPO), ROS production and malondialdehyde (MDA) were inhibited by NecroX-5 administration. Thus, our results demonstrate that NecroX-5 protects against LPS-induced ALI by inhibiting TXNIP/NLRP3 and NF-κB.     

Dexamethasone alleviate allergic airway inflammation in mice by inhibiting the activation of NLRP3 inflammasome

Dexamethasone (DEX) is the mainstay treatment for asthma, which is a common chronic airway inflammation disease. However, the mechanism of DEX resolute symptoms of asthma is not completely clear. Here, we aimed to analyze the effect of DEX on airway inflammation in OVA-induced mice and whether this effect is related to the inhibition of the activation of NLRP3 inflammasome. Female (C57BL/6) mice were used to establish the allergic airway inflammation model by inhalation OVA. The number of inflammatory cells in the bronchi alveolar lavage fluid (BALF) was counted by Swiss-Giemsa staining, and the contents of IL-1β, IL-18, IL-5 and IL-17 were detected by ELISA. The degree of inflammatory cells infiltration and mucous cells proliferation in lung tissue were separately observed by H&E and PAS staining. The proteins expression of NLRP3, pro-caspase-1, caspase-1, IL-1β, IL-6 and IL-17 in lung tissue were detected by Western blotting. We found that DEX significantly inhibited OVA-induced inflammatory cells infiltration, airway mucus secretion and goblet cell proliferation in mice. The total and classified numbers of inflammatory cells and the levels of IL-1β, IL-18, IL-5 and IL-17 in the BALF of the experimental group were significantly lower than those of the model group after DEX treatment. DEX also significantly inhibited the activity of NLRP3 inflammasome and reduced the protein contents of Pro-Caspase-1, Caspase-1, Capase-1/Pro-Caspase-1, IL-1β, IL-6 and IL-17 in lung tissues. Our study suggested that DEX alleviates allergic airway inflammation by inhibiting the activity of NLRP3 inflammasome and the levels of IL-1β and IL-18.     

Involvement of endoplasmic reticulum stress in angiotensin II-induced NLRP3 inflammasome activation in human renal proximal tubular cells in vitro

Aim:

NLRP3 inflammasome plays an important role in renal injury and may be a therapeutic target in the treatment of patients with progressive chronic kidney disease. In this study we investigated whether angiotensin II (Ang II)-induced NLRP3 inflammasome activation was linked to endoplasmic reticulum stress (ERS) in human renal proximal tubular cells in vitro.

Methods:

Human kidney proximal epithelial cells (HK-2) were pretreated with telmisartan or 4-PBA, and then treated with Ang II. The expression levels of mRNAs and proteins related to NLRP3 inflammasomes and ERS was examined by real-time PCR, Western blot and immunofluorescence.

Results:

Treatment with Ang II (10, 100, and 1000 nmol/L) increased the expression of the inflammasome markers NLRP3 and ASC, as well as caspase-1, IL-1β, and IL-18 in dose- and time-dependent manners with peak levels detected at 100 nmol/L and 12 h. Ang II-induced increases in the expression of NLRP3, ASC, caspase-1, IL-1β, and IL-18 were significantly reduced by pretreatment with telmisartan (1 μmol/L). Immunofluorescence studies showed that Ang II increased the expression of NLRP3 and ASC, which was inhibited by telmisartan. Furthermore, Ang II treatment increased the expression of ERS markers GRP78 and p-eIF2α in dose- and time-dependent manners, which was significantly reduced by telmisartan. Moreover, Ang II-induced increases in the expression of NLRP3, ASC, caspase-1, IL-1β, and IL-18 were significantly inhibited by pretreatment with the ERS inhibitor 4-PBA (5 mmol/L).

Conclusion:

Ang II treatment induces NLRP3 inflammasome activation in HK-2 cells in vitro and ER stress is involved in this process, which may represent a new mechanism for the renal rennin-angiotensin system to induce tubulointerstitial inflammation.     

Genipin alleviates LPS-induced acute lung injury by inhibiting NF-κB and NLRP3 signaling pathways

Genipin has been reported to have anti-inflammatory effect. However, its role on lipopolysaccharide (LPS)-induced acute lung injury (ALI) has not been explored. This study aimed to evaluate the effect of genipin on murine model of acute lung injury induced by LPS. The mice were treated with genipin 1 h before LPS administration. 12 h later, the myeloperoxidase (MPO) in lung tissues and lung wet/dry ratio were detected. The levels of TNF-α, IL-1β and IL-6 in bronchoalveolar lavage fluid (BALF) were measured by ELISA. Apart from this, we use western blot to detect the protein expression in the NF-κB and NLRP3 signaling pathways. The results showed that the treatment of genipin markedly attenuated the lung wet/dry ratio and the MPO activity. Moreover, it also inhibited the levels of TNF-α, IL-1β, IL-6 in the BALF. In addition, genipin significantly inhibited LPS-induced NF-κB and NLRP3 activation. In conclusion, these results demonstrate that genipin protected against LPS-induced ALI through inhibiting NF-κB and NLRP3 signaling pathways.     

Extracellular HMGB1 regulates multi-walled carbon nanotube-induced inflammation in vivo

Abstract

Endotoxin is often used to activate NF-κB in vitro when assessing NLRP3 inflammasome activation by various exogenous particles including nanoparticles. However, the endogenous source of this signal 1 is unknown. High-mobility group box 1 (HMGB1) is known to play a critical role in acute lung injury, however the potential contribution of the alarmin HMGB1 to NLRP3 Inflammasome activation has not been determined in response to nanoparticles in vivo. In this study, the ability of multi-walled carbon nanotubes (MWCNT) to cause release of HMGB1 in vitro and in vivo, as well as the potential of HMGB1 to function as signal 1 in vitro and in vivo, was determined. HMGB1 activity in vivo was assessed by administration of HMGB1 neutralization antibodies following MWCNT exposure. Caspase-1^?/? mice were utilized to elucidate the dependence of HMGB1 secretion on NLRP3 inflammasome activity. MWCNT exposure increased extracellular HMGB1 levels in primary alveolar macrophages from C57Bl/6 mice and C10 mouse epithelial cell culture supernatants, and in C57Bl/6 mouse lung lavage fluid. MWCNT-induced HMGB1 secretion was dependent upon caspase-1. HMGB1 increased MWCNT-induced IL-1β release from macrophages in vitro, and neutralization of extracellular HMGB1 reduced MWCNT-induced IL-1β secretion in vivo. HMGB1 neutralization was accompanied with overall decreased inflammation. In summary, this study suggests extracellular HMGB1 participates in NLRP3 inflammasome activity and regulates IL-1β associated sterile inflammation induced by MWCNT.     

POSTTREATMENT WITH ETYA PROTECTS AGAINST PHOSGENE-INDUCED LUNG INJURY BY AMPLIFYING THE GLUTATHIONE TO LIPID PEROXIDATION RATIO

Exposure to phosgene has been shown to cause severe and life-threatening pulmonary edema. There is evidence that successful treatment of phosgene-induced acute lung injury may be related to increased antioxidant activity. Acetylenic acids such as 5,8,11,14-eicosatetraynoic acid (ETYA) have been shown to be effective in preventing pulmonary edema formation (PEF). In phosgene-exposed guinea pigs, we examined the effects of ETYA on PEF. Lipid peroxidation (thiobarbituric acid-reactive substance, TBARS) and total glutathione (GSH) were measured in lung tissue from isolated, buffer-perfused guinea pig lungs at 180 min after start of exposure. Guinea pigs were challenged with 175 mg/m³ (44 ppm) phosgene for 10 min (1750 mg min/m³). Five minutes after removal from the exposure chamber, guinea pigs were treated, ip, with 200 mu l of 100 mu M ETYA in ethanol (ETOH). Two hundred microliters of 50 mu M ETYA in ETOH was added to the 200 ml perfusate every 40 min beginning at 60 min after start of exposure (t = 0). There were four groups in this study: air-exposed, phosgene-exposed, phosgene + ETYA-posttreated, and air + ETYA-posttreated. Posttreatment with ETYA prevented GSH depletion, 2.7 +/- 0.5 mu mol/mg protein versus 1 +/- 0.2 mu mol/mg protein, for the untreated phosgene-exposed lungs (p less than or equal to.05). ETYA posttreatment also significantly decreased PEF (p less than or equal to.025), as measured by lung wet weight/dry weight ratio, 16.1 +/- 2.5 versus 8.5 +/- 1 for phosgene-exposed + ETYA-posttreated guinea pigs. Postexposure treatment with ETYA significantly increased the GSH to TBARS protection ratio, 12 +/- 2, compared with the phosgene-exposed group, 3.7 +/- 0.5 (p less than or equal to.05). In conclusion, ETYA posttreatment decreased PEF by increasing the GSH/TBARS protection ratio by functioning in an antioxidant-like capacity.     

Rapamycin ameliorates lipopolysaccharide-induced acute lung injury by inhibiting IL-1β and IL-18 production

Interleukin (IL)-1β and IL-18 play central and detrimental roles in the development of acute lung injury (ALI), and mammalian target of rapamycin (mTOR) is involved in regulating IL-1β and IL-18 production. However, it is not clear whether the mTOR specific inhibitor rapamycin can attenuate lipopolysaccharide (LPS)-induced ALI by modulating IL-1β and IL-18 production. In this study, we found that rapamycin ameliorated LPS-induced ALI by inhibiting NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome-mediated IL-1β and IL-18 secretion. Mechanistically, elevated autophagy and decreased nuclear factor (NF)-κB activation were associated with downregulated IL-1β and IL-18. Moreover, rapamycin reduced leukocyte infiltration in the lung tissue and bronchoalveolar lavage fluid (BALF), and contributed to the alleviation of LPS-induced ALI. Consistently, rapamycin also significantly inhibited IL-1β and IL-18 production by RAW264.7 cells via increased autophagy and decreased NF-κB signaling in vitro. Our results demonstrated that rapamycin protects mice against LPS-induced ALI partly by inhibiting the production and secretion of IL-1β and IL-18. mTOR and rapamycin might represent an appropriate therapeutic target and strategy for preventing ALI induced by LPS.     

Fraxinol attenuates LPS-induced acute lung injury by equilibrating ACE-Ang II-AT1R and ACE2-Ang (1-7)-Mas and inhibiting NLRP3

ContextAcute lung injury (ALI) is a serious heterogenous pulmonary disorder. Fraxinol was selected for this study since it is a simple coumarin compound, not previously investigated in ALI.ObjectivesThis study investigates the ALI therapeutic effect and mechanisms of fraxinol.Materials and methodsMale BALB/c mice were treated with fraxinol (20, 40, and 80 mg/kg) following intranasal injection of lipopolysaccharide (LPS; 10 μg in 50 μL). The mice in control group were intratracheally injected with 50 μL phosphate buffered saline (PBS). Raw264.7 cells were treated with fraxinol by 100 ng/mL LPS for 6 h, then treated by different concentrations of fraxinol (5, 10, and 25 μM) for 48 h. Cells in control group were treated with PBS.ResultsFraxinol with doses of 20, 40, and 80 mg/kg significantly attenuated LPS-induced lung injury in mice (lung injury score, 10.4, 31.2, 50.3%). Fraxinol attenuated the apoptosis and nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing-3 (NLRP3) activation induced by LPS (apoptosis, 18.3, 30.2, 55.6%; NLRP3, 30.0, 47.7, 63.6%). The anti-apoptosis and anti-inflammation effects of fraxinol were also confirmed in Raw264.7 cells (apoptosis, 38.8, 55.3, 68.9%; NLRP3, 20.6, 55.7, 73.9%).Discussion and conclusionThe anti-ALI effects of fraxinol maybe by equilibrating ACE-Ang II-AT1R and ACE2-Ang (1-7)-Mas axis and inhibiting NLRP3 inflammasome. Our research provides a candidate drug in the treatment of ALI.     

Posttreatment with ETYA protects against phosgene-induced lung injury by amplifying the glutathione to lipid peroxidation ratio

Exposure to phosgene has been shown to cause severe and life-threatening pulmonary edema. There is evidence that successful treatment of phosgene-induced acute lung injury may be related to increased antioxidant activity. Acetylenic acids such as 5,8,11, 14-eicosatetraynoic acid (ETYA) have been shown to be effective in preventing pulmonary edema formation (PEF). In phosgene-exposed guinea pigs, we examined the effects of ETYA on PEF. Lipid peroxidation (thiobarbituric acid-reactive substance, TBARS) and total glutathione (GSH) were measured in lung tissue from isolated, buffer-perfused guinea pig lungs at 180 min after start of exposure. Guinea pigs were challenged with 175 mg/m(3) (44 ppm) phosgene for 10 min (1750 mg( small middle dot)min/m(3)). Five minutes after removal from the exposure chamber, guinea pigs were treated, ip, with 200 microl of 100 microM ETYA in ethanol (ETOH). Two hundred microliters of 50 microM ETYA in ETOH was added to the 200 ml perfusate every 40 min beginning at 60 min after start of exposure (t = 0). There were four groups in this study: air-exposed, phosgene-exposed, phosgene + ETYA-posttreated, and air + ETYA-posttreated. Posttreatment with ETYA prevented GSH depletion, 2. 7 +/- 0.5 micromol/mg protein versus 1 +/- 0.2 micromol/mg protein, for the untreated phosgene-exposed lungs (p < or =.05). ETYA posttreatment also significantly decreased PEF (p 相似文献   

Glyburide attenuates ozone‐induced pulmonary inflammation and injury by blocking the NLRP3 inflammasome

Glyburide is a classic antidiabetic drug that is dominant in inflammation regulation, but its specific role in ozone‐induced lung inflammation and injury remains unclear. In order to investigate whether glyburide prevents ozone‐induced pulmonary inflammation and its mechanism, C57BL/6 mice were intratracheally pre‐instilled with glyburide or the vehicle 1 hour before ozone (1 ppm, 3 hours) or filtered air exposure. After 24 hours, the total inflammatory cells and total protein in bronchoalveolar lavage fluid (BALF) were detected. The pathological alternations in lung tissues were evaluated by HE staining. The expression of NLRP3, interleukin‐1β (IL‐1β), and IL‐18 protein in lung tissues was detected by immunohistochemistry. Western blotting was used to examine the levels of caspase‐1 p10 and active IL‐1β protein. Levels of IL‐1β and IL‐18 in BALF were measured using ELISA kits. Glyburide treatment decreased the total cells in BALF, the inflammatory score, and the mean linear intercept induced by ozone in lung tissues. In addition, glyburide inhibited the expression of NLRP3, IL‐18, and IL‐1β protein in lung tissues, and also suppressed NLRP3 inflammasome activation, including caspase‐1 p10, active IL‐1β protein in lung tissues, IL‐1β, and IL‐18 in BALF. These results demonstrate that glyburide effectively attenuates ozone‐induced pulmonary inflammation and injury via blocking the NLRP3 inflammasome.