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Phosgene is a type of poisonous gas that can cause acute lung injury (ALI) upon accidental exposure. Casualties still occur due to phosgene-induced acute lung injury (P-ALI) from accidents resulting from improper operations. The pathological mechanisms of P-ALI are still understudied. Thus, we performed scRNA-seq on cells isolated from all subpopulations of the BALF in P-ALI and found that Gal3 expression was significantly higher in the gas group than in the control group. Further analysis revealed a ligand-receptor correspondence between alveolar macrophages (AMs) and alveolar epithelial cells (AEC), with Gal3 playing a key role in this interaction. To confirm and elaborate on this discovery, we selected four time points during the previous week: sham (day 0), day 1, day 3, and day 7 in the P-ALI mouse model and found that Gal3 expression was significantly elevated in P-ALI, most abundantly expressed in AM cells. This was further confirmed with the use of a Gal3 inhibitor. The inhibition of Gal3 and elimination of AMs in mice both attenuated epithelial cell pyroptosis, as confirmed in in vitro experiments, and revealed the Gal3/caspase-8/GSDMD signaling pathway. These findings suggest that Galectin-3 inhibition can ameliorate AEC pyroptosis by inhibiting the Gal3/caspase-8/GSDMD signaling pathway, thus reducing alveolar damage in mice with P-ALI. This finding provides novel insights for improving treatment efficacy for P-ALI., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

In the absence of an identified source of carbon, the reported formation of phosgene from bleach powder is questioned. Interferences and confounding effects other than those investigated by the authors may have led to artifactual results.

Phosgene oxime (CX), categorized as a vesicating chemical threat agent, causes effects that resemble an urticant or nettle agent. CX is an emerging potential threat agent that can be deployed alone or with other chemical threat agents to enhance their toxic effects. Studies on CX-induced skin toxicity, injury progression, and related biomarkers are largely unknown. To study the physiologic changes, skin clinical lesions and their progression, skin exposure of SKH-1 and C57BL/6 mice was carried out with vapor from 10 μ l CX for 0.5-minute or 1.0-minute durations using a designed exposure system for consistent CX vapor exposure. One-minute exposure caused sharp (SKH-1) or sustained (C57BL/6) decrease in respiratory and heart rate, leading to mortality in both mouse strains. Both exposures caused immediate blanching, erythema with erythematous ring (wheel) and edema, and an increase in skin bifold thickness. Necrosis was also observed in the 0.5-minute CX exposure group. Both mouse strains showed comparative skin clinical lesions upon CX exposure; however, skin bifold thickness and erythema remained elevated up to 14 days postexposure in SKH-1 mice but not in C57BL/6 mice. Our data suggest that CX causes immediate changes in the physiologic parameters and gross skin lesions resembling urticaria, which could involve mast cell activation and intense systemic toxicity. This novel study recorded and compared the progression of skin injury to establish clinical biomarkers of CX dermal exposure in both the sexes of two murine strains relevant for skin and systemic injury studies and therapeutic target identification. SIGNIFICANCE STATEMENT: Phosgene oxime (CX), categorized as a vesicating agent, is considered as a potent chemical weapon and is of high military and terrorist threat interest since it produces rapid onset of severe injury as an urticant. However, biomarkers of clinical relevance related to its toxicity and injury progression are not studied. Data from this study provide useful clinical markers of CX skin toxicity in mouse models using a reliable CX exposure system for future mechanistic and efficacy studies., (Copyright © 2024 by The American Society for Pharmacology and Experimental Therapeutics.)

We present the first computational model of the pathophysiological consequences of phosgene-induced lung injury in porcine subjects. Data from experiments previously performed in several cohorts of large healthy juvenile female pigs (111 data points from 37 subjects), including individual arterial blood gas readings, respiratory rate and heart rate, were used to develop the computational model. Close matches are observed between model outputs (PaO 2 and PaCO 2 ) and the experimental data, for both terminally anaesthetised and conscious subjects. The model was applied to investigate the effectiveness of continuous positive airway pressure (CPAP) as a pre-hospital treatment method when treatment is initiated at different time points post exposure. The model predicts that clinically relevant benefits are obtained when 10 cmH 2 O CPAP is initiated within approximately 8 h after exposure. Supplying low-flow oxygen (40%) rather than medical air produced larger clinical benefits than applying higher CPAP pressure levels. This new model can be used as a tool for conducting investigations into ventilation strategies and pharmaceutical treatments for chemical lung injury of diverse aetiology, and for helping to refine and reduce the use of animals in future experimental studies., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Inhalation of high concentrations of phosgene often causes pulmonary edema, which obstructs the airway and causes tissue hypoxia. There is currently no specific antidote. This study was performed to investigate the effect behind pentoxifylline (PTX) treatment for phosgene-induced lung injury in rat models. Rats were exposed to phosgene. The protein levels of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), and occludin proteins in lung tissue were determined. The effect of both prophylactic and therapeutic administration of PTX (50 mg/kg and 100 mg/kg) was evaluated. The lung permeability index and HIF-1α protein level increased, the arterial blood oxygenation index (PaO 2 /FIO 2 ratio) and occludin protein level decreased significantly 6 h after phosgene exposure ( P < 0.05). PTX exerted protective effects by HIF-1α-VEGF-occludin signaling pathway to some extent. Moreover, prophylactic, but not therapeutic administration of PTX (100 mg/kg), exhibited a significant protective effect. Pretreatment with PTX protected against phosgene-induced lung injury, possibly by inhibiting differential expression of HIF-1α, VEGF, and occludin.

Phosgene is widely used as an industrial chemical, and phosgene inhalation causes acute lung injury (ALI), which may further progress into pulmonary edema. Currently, an antidote for phosgene poisoning is not known. Alpha-1 antitrypsin (α1-AT) is a protease inhibitor used to treat patients with emphysema who are deficient in α1-AT. Recent studies have revealed that α1-AT has both anti-inflammatory and anti-SARS-CoV-2 effects. Herein, we aimed to investigate the role of α1-AT in phosgene-induced ALI. We observed a time-dependent increase in α1-AT expression and secretion in the lungs of rats exposed to phosgene. Notably, α1-AT was derived from neutrophils but not from macrophages or alveolar type II cells. Moreover, α1-AT knockdown aggravated phosgene- and lipopolysaccharide (LPS)-induced inflammation and cell death in human bronchial epithelial cells (BEAS-2B). Conversely, α1-AT administration suppressed the inflammatory response and prevented death in LPS- and phosgene-exposed BEAS-2B cells. Furthermore, α1-AT treatment increased the inhibitor of DNA binding 1 (ID1) gene expression, which suppressed NF-κB pathway activation, reduced inflammation, and inhibited cell death. These data demonstrate that neutrophil-derived α1-AT acts as a self-protective mechanism, which protects against phosgene-induced ALI by activating the ID1-dependent anti-inflammatory response. This study may provide novel strategies for the treatment of patients with phosgene-induced ALI., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

In contrast to water-soluble respiratory tract irritants in their gas phase, the physicochemical properties of 'hydrophilicity' vs. 'lipophilicity' are the preponderant factors that dictate the site of major retention of the gas at the portal of entry. The lipophilic physical properties of phosgene gas facilitate retention in the alveolar region lined with amphipathic pulmonary surfactant (PS). The relationship between exposure and adverse health outcomes is complex, may vary over time, and is dependent on the biokinetics, biophysics, and pool size of PS relative to the inhaled dose of phosgene. Kinetic PS depletion is hypothesized to occur as inhalation followed by inhaled dose-dependent PS depletion. A kinetic model was developed to better understand the variables characterizing the inhaled dose rates of phosgene vs. PS pool size reconstitution. Modeling and empirical data from published evidence revealed that phosgene gas unequivocally follows a concentration x exposure (C × t) metric, independent of the frequency of exposure. The modeled and empirical data support the hypothesis that the exposure standards of phosgene are described best by a C × t time-averaged metric. Modeled data favorably duplicate expert panel-derived standards. Peak exposures within a reasonable range are of no concern., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

We studied the content of aquaporin-5 (AQP 5 ) and epithelial sodium channel (ENaC) in rat lungs during the development of toxic pulmonary edema (TPE) caused by intoxication with phosgene and perfluoroisobutylene (1.5 LC 50 ). The lung body weight index (LBI) was calculated and histological examination of the lung tissues was performed. Localization and expression of AQP 5 and ENaC were determined by immunohistochemistry. Intoxication led to a significant (p<0.05) increase in LBI and histological changes typical of TPE 1 and 3 h after the exposure. In 1 and 3 h after phosgene intoxication, the AQP 5 and ENaC content significantly (p<0.05) increased in comparison with the control. Similar changes in the AQP 5 and ENaC content were observed 1 and 3 h after exposure to perfluoroisobutylene. It was hypothesized that AQP 5 plays an important role in the formation of TPE caused by intoxication with acylating pulmonotoxicants. An increase in the content of ENaC can be considered as a compensatory reaction of the body aimed at clearance of the alveolar fluid., (© 2022. Springer Science+Business Media, LLC, part of Springer Nature.)

The improper use of phosgene, either as a chemical warfare agent or a leak during chemical production, causes significant risks to human life and property. Therefore, it is particularly important to develop a rapid and highly selective method for the detection of phosgene. In this article, a highly selective fluorescent sensor ONB with a BODIPY unit as a fluorophore and o-aminophenol as a reactive site was constructed for the selective and rapid detection of phosgene in solution. The ONB-containing nanofibers were sprayed onto a non-woven fabric by electrostatic spinning and cut into test films, which can be used well for the detection of gaseous phosgene. While, there were no reported bio-imaging applications for phosgene detection. In this work, nasal mucosa and lung samples from the mice exposed to gaseous phosgene after dropping the ONB solution through the nasal cavity achieved bio-imaging applications successfully., (© 2022. Springer-Verlag GmbH Germany, part of Springer Nature.)

The present study compares acute and subchronic episodic exposures to phosgene to test the applicability of the 'concentration×time' (C×T) product as a measure of exposure dose, and to relate acute toxicity and adaptive responses to chronic toxicity. Rats (male Fischer 344) were exposed (six hours/day) to air or 0.1, 0.2, 0.5 and 1.0 ppm of phosgene one time or on a repeated regimen for up to 12 weeks as follows: 0.1 ppm (five days/week), 0.2 ppm (five days/week), 0.5 ppm (two days/week), or 1.0 ppm (one day/week) (note that the C×T for the three highest exposures was the same). Animals were sacrificed at 4, 8, and 12 weeks during the exposure and after four weeks recovery. Bronchoalveolar lavage (BAL) was performed 18 hours after the last exposure for each time period and the BAL supernatant assayed for protein. Elevated BAL fluid protein was defined as 'acute injury', diminished response after repeated exposure was defined as 'adaptation', and increased lung hydroxyproline or trichrome staining for collagen was defined as 'chronic injury'. Results indicated that exposures that cause maximal chronic injury involve high exposure concentrations and longer times between exposures, not high C×T products. A conceptual model is presented that explains the lack of C×T correlation by the fact that adaptation reduces an 'injury-time integral' as phosgene exposure is lengthened from acute to subchronic. At high exposure concentrations, the adaptive response appears to be overwhelmed, causing a continued injury-time integral, which appears to be related to appearance of chronic injury. The adaptive response is predicted to disappear if the time between exposures is lengthened, leading to a continued high injury-time integral and chronic injury. It has generally been assumed that long, continuous exposures of rodents is a conservative approach for detecting possible chronic effects. The present study suggests that such an approach my not be conservative, but might actually mask effects that could occur under intermittent exposure conditions. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) have promising potential in the treatment of various diseases, such as the therapeutic effect of bone marrow-derived MSCs for phosgene-induced acute lung injury (P-ALI). However, MSC-related therapeutics are limited due to poor cell survival, requiring appropriate MSC delivery systems to maximise therapeutic capacity. Biomaterial RGD-hydrogel is a potential cell delivery vehicle as it can mimic the natural extracellular matrix and provide cell adhesion support. The application of RGD-hydrogel in the MSC treatment of respiratory diseases is scarce. This study reports that RGD-hydrogel has good biocompatibility and can increase the secretion of Angiopoietin-1, hepatocyte growth factor, epidermal growth factor, vascular endothelial cell growth factor, and interleukin-10 in vitro MSCs. The hydrogel-encapsulated MSCs could further alleviate P-ALI and show better cell survival in vivo . Overall, RGD-hydrogel could improve the MSC treatment of P-ALI by modulating cell survival and reparative activities. It is exciting to see more and more ways to unlock the therapeutic potential of MSCs., Competing Interests: The authors declare that there are no conflicts of interest regarding the publication of this article., (Copyright © 2022 Jianwen Ding et al.)

Phosgene gas leakage can cause life-threatening acute lung injury (ALI), which is characterized by inflammation, increased vascular permeability, pulmonary oedema and oxidative stress. Although the downregulation of neuronal precursor cell-expressed developmentally downregulated 4 (NEDD4) is known to be associated with inflammation and oxidative damage, its functions in phosgene-induced ALI remain unclear. In this study, rats with phosgene-induced ALI were intravenously injected with NEDD4-overexpressing lentiviruses to determine the functions of NEDD4 in this inflammatory condition. NEDD4 expression was decreased in the lung parenchyma of phosgene-exposed control rats, whereas its expression level was high in the NEDD4-overexpressing rats. Phosgene exposure increased the wet-to-dry lung weight ratio, but NEDD4 abrogated this effect. NEDD4 overexpression attenuated phosgene-induced lung inflammation, lowering the high lung injury score (based on total protein, inflammatory cells and inflammatory factors in bronchoalveolar lavage fluid) and also reduced phosgene-induced oxidative stress and cell apoptosis. Finally, NEDD4 was found to interact with Notch1, enhancing its ubiquitination and thereby its degradation, thus attenuating the inflammatory responses to ALI. Therefore, we demonstrated that NEDD4 plays a protective role in alleviating phosgene-induced ALI, suggesting that enhancing the effect of NEDD4 may be a new approach for treating phosgene-induced ALI., (© 2022 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Since their use during the First World War, Blister agents have posed a major threat to the individuals and have caused around two million casualties. Major incidents occurred not only due to their use as chemical warfare agents but also because of occupational hazards. Therefore, a clear understanding of these agents and their mode of action is essential to develop effective decontamination and therapeutic strategies. The blister agents have been categorised on the basis of their chemistry and the biological interactions that entail post contamination. These compounds have been known to majorly cause blisters/bullae along with alkylation of the contaminated DNA. However, due to the high toxicity and restricted use, very little research has been conducted and a lot remains to be clearly understood about these compounds. Various decontamination solutions and detection technologies have been developed, which have proven to be effective for their timely mitigation. But a major hurdle seems to be the lack of proper understanding of the toxicological mechanism of action of these compounds. Current review is about the detailed and updated information on physical, chemical and biological aspects of various blister agents. It also illustrates the mechanism of their action, toxicological effects, detection technologies and possible decontamination strategies., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Objective: To investigate the changes in kidney and its mechanism during the development of acute phosgene exposure in rats. Methods: Rats were randomized into 2 groups: control and phosgene group (including 1, 3, 6, 12 and 24 h after exposed to phosgene) , 6 rats in each group. Rats in control group were exposed to air for 5 min, while rats in phosgene group were exposed to 8.33 mg/L phosgene for 5 min. The blood samples were collected at 1, 3, 6, 12 and 24 h after phosgene exposure. The blood creatinine (Cr) , urea nitrogen (BUN) and blood gas analysis were detected. HE staining and immunohistochemical staining were performed to observe the expression levels of 8-hydroxy deoxyguanosine and myeloperoxidase. Results: The arterial partial pressure of oxygen and oxygenation index of rats in the phosgene group were significantly lower than those in the control group at 3, 6 and 12 h after exposure ( P <0.01) . The lowest points were reached at 6 h, which were (58.67±7.89) mmHg and (202.30±27.20) mmHg, respectively. The Cr and BUN of rats in the phosgene group were significantly higher than those in the control group at 3, 6, 12, and 24 h, and the renal organ coefficients were significantly higher than those in the control group at 3, 6 and 12 h ( P <0.01) . HE staining showed that there were more erythrocytes in the glomeruli of rats in the phosgene group, the volume of renal tubular epithelial cells increased, and the cytoplasm was loose and lightly stained. The damage was most obvious at 6 h. The results of immunohistochemical staining showed that the positive expressions of 8-hydroxy deoxyguanosine and myeloperoxidase in the kidney tissue of the phosgene group increased. Conclusion: Hypoxemia and oxidative stress caused by phosgene poisoning may be the cause of renal damage in rats.

Phosgene (COCl 2 ) was once used as a classic suffocation poison and currently plays an essential role in industrial production. Due to its high toxicity, the problem of poisoning caused by leakage during production, storage, and use cannot be ignored. Phosgene mainly acts on the lungs, causing long-lasting respiratory depression, refractory pulmonary edema, and other related lung injuries, which may cause acute respiratory distress syndrome or even death in severe cases. Due to the high mortality, poor prognosis, and frequent sequelae, targeted therapies for phosgene exposure are needed. However, there is currently no specific antidote for phosgene poisoning. This paper reviews the literature on the mechanism and treatment strategies to explore new ideas for the treatment of phosgene poisoning.

Phosgene may induce acute lung injury (ALI) when a person is exposed to it. Mesenchymal stem cells (MSCs) were affirmed to have therapeutic effects on phosgene-induced ALI. In a previous study, ALI exosomes have been confirmed to promote the proliferation and migration of MSCs. However, the mechanism of this phenomenon is still unclear. MicroRNAs (miRNAs) are essential in the physiological process of cells. In this study, lung-derived exosomes were isolated from phosgene-exposed and normal rats, respectively, through ultracentrifugation and cultured MSCs with these exosomes. We found that rno-miR-34c-3p was downregulated in MSCs cocultured with ALI exosomes. MiR-34c-3p inhibitor promoted the proliferation and migration of MSCs. Moreover, the dual-luciferase reporter assay demonstrated that miR-34c-3p regulated Janus kinase 1 (JAK1) expression. The miR-34c-3p inhibitor also significantly activated the JAK1/signal transducer and activator of transcription 3 (STAT3) signaling pathway. In conclusion, ALI exosomes decrease the miR-34c-3p expression levels, influencing MSCs via the JAK1/STAT3 signaling pathway., (© 2021 Wiley Periodicals LLC.)

Phosgene is a gas crucial to industrial chemical processes with widespread production (∼1 million tons/year in the USA, 8.5 million tons/year worldwide). Phosgene's high toxicity and physical properties resulted in its use as a chemical warfare agent during the First World War with a designation of CG ('Choky Gas'). The industrial availability of phosgene makes it a compound of concern as a weapon of mass destruction by terrorist organizations. The hydrophobicity of phosgene exacerbates its toxicity often resulting in a delayed toxidrome as the upper airways are moderately irritated; by the time symptoms appear, significant damage has occurred. As the standard of care for phosgene intoxication is supportive therapy, a pressing need for effective therapeutics and treatment regimens exists. Proposed toxicity mechanisms for phosgene based on human and animal exposures are discussed. Whereas intermediary components in the phosgene intoxication pathways are under continued discussion, generation of reactive oxygen species and oxidative stress is a common factor. As animal models are required for the study of phosgene and for FDA approval via the Animal Rule; the status of existing models and their adherence to Haber's Rule is discussed. Finally, we review the continued search for efficacious therapeutics for phosgene intoxication; and present a rapid post-exposure response that places exogenous human heat shock protein 72, in the form of a cell-penetrating fusion protein (Fv-HSP72), into lung tissues to combat apoptosis resulting from oxidative stress. Despite significant progress, additional work is required to advance effective therapeutics for acute phosgene exposure.

Highly toxic industrial chemicals that are widely accessible, and hazardous chemicals like phosgene oxime (CX) that can be easily synthesized, pose a serious threat as potential chemical weapons. In addition, their accidental release can lead to chemical emergencies and mass casualties. CX, an urticant, or nettle agent, grouped with vesicating agents, causes instant pain, injury and systemic effects, which can lead to mortality. With faster cutaneous penetration, corrosive properties, and more potent toxicity compared to other vesicating agents, CX causes instantaneous and severe tissue damage. CX, a potential chemical terrorism threat agent, could therefore be weaponized with other chemical warfare agents to enhance their harmful effects. CX is the least studied vesicant and its acute and long-term toxic effects as well as its mechanism of action are largely unknown. This has hampered the identification of therapeutic targets and the development of effective medical countermeasures. There are only protective measures, decontamination, and supportive treatments available for reducing the toxic effects from CX exposure. This review summarizes CX toxicity, its known mechanism of action, and our current studies exploring the role of mast cell activation and associated signaling pathways in CX cutaneous exposure under the National Institutes of Health Countermeasures Against Chemical Threats program. Potential treatment options and the development of effective targeted countermeasures against CX-induced morbidity and mortality is also discussed.

Phosgene (carbonyl dichloride) gas is an indispensable high-production-volume chemical intermediate used worldwide in numerous industrial processes. Published evidence of human exposures due to accidents and warfare (World War I) has been reported; however, these reports often lack specificity because of the uncharacterized exposure intensities of phosgene and/or related irritants. These may include liquid or solid congeners of phosgene, including di- and triphosgene and/or the respiratory tract irritant chlorine which are often collectively reported under the umbrella of phosgene exposure without any appreciation of their differences in causing acute lung injury (ALI). Among these irritants, phosgene gas is somewhat unique because of its poor water solubility. This prevents any appreciable retention of the gas in the upper airways and related trigeminal sensations of irritation. By contrast, in the pulmonary compartment, amphiphilic surfactant might scavenge this lipophilic gas. The interaction of phosgene and the surfactant may affect basic physiological functions controlled by Starling's and Laplace's laws, which can be followed by cardiogenic pulmonary edema. The phenotypic manifestations are dependent on the concentration × exposure duration (C × t); the higher the C × t is, the less time that is required for edema to appear. It is hypothesized that this type of edema is caused by cardiovascular and colloid osmotic imbalances to initial neurogenic events but not because of the injury itself. Thus, hemodynamic etiologies appear to cause imbalances in extravasated fluids and solute accumulation in the pulmonary interstitium, which is not drained away by the lymphatic channels of the lung. The most salient associated findings are hemoconcentration and hypoproteinemia. The involved intertwined pathophysiological processes coordinating pulmonary ventilation and cardiopulmonary perfusion under such conditions are complex. Pulmonary arterial catheter measurements on phosgene-exposed dogs provided evidence of 'cor pulmonale', a form of acute right heart failure produced by a sudden increase in resistance to blood flow in the pulmonary circulation about 20 h postexposure. The objective of this review is to critically analyze evidence from experimental inhalation studies in rats and dogs, and evidence from accidental human exposures to better understand the primary and secondary events causing cardiopulmonary dysfunction and an ensuing life-threatening lung edema. Mechanism-based diagnostic and therapeutic approaches are also considered for this form of cardiogenic edema., (Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objective: To investigate the effect of heat shock protein 60 (HSP60) overexpression on the ability of bone marrow mesenchymal stem cells (MSCs) and its therapeutic effect on rats with phosgene induced acute lung injury. Methods: HSP60 was transfected into MSCs by adenovirus. Western blot was used to measure the expressions of HSP60 before and after transfection. CCK-8 assay was used to detect the activity of MSCs, flow cytometry was used to detect the apoptotic ability of MSCs, and Transwell assay was used to observe the migration ability of MSCs. Sixty SPF grade male SD rats were randomly divided into control group, phosgene exposure group (inhalation of phosgene for 5 min) , MSCs group (phosgene exposure, MSCs treatment group) and transfected MSCs group (phosgene exposure, overexpression of HSP60 MSCs treatment group) . The pathological changes of lung were observed by lung pathological section, lung wet dry ratio, the degree of pulmonary edema, the total cell count and total protein content of alveolar lavage fluid, the inflammatory changes of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in BALF and serum were observed. The data were analyzed by Graphpad Prism 8.0 software. Paired comparisons were performed by non paired t- test. One way ANOVA was used for comparison between groups. Results: The proliferation ability of MSCs transfected with HSP60[ A = (0.69±0.05) ] was significantly higher than that of MSCs not transfected with HSP60[ A = (0.27±0.02) ] ( P <0.05) . Compared with the phosgene exposure group, the pulmonary edema and inflammatory factor infiltration of MSCs group and MSCs transfected group were reduced. However, compared with MSCs group, the degree of pulmonary edema in MSCs transfected group was significantly improved, the levels of inflammatory factors IL-6 and TNF-α were significantly decreased, and the total protein content and total cell count in bronchoalveolar lavage fluid were less ( P <0.05) . Conclusion: MSCs transfected with HSP60 can enhance the ability of proliferation, anti apoptosis, migration and the curative effect in rats with phosgene induced acute lung injury.

In our previous study, we have confirmed that in phosgene-induced acute lung injury (ALI) rats, mesenchymal stem cells (MSCs) can treat the disease. Moreover, heat shock protein 70 (Hsp70) can be used as a protective protein, and Hsp70 upregulated drastically when exposed to stressful conditions. We aimed to assess that MSCs overexpressed Hsp70 could enhance the capacity of MSCs and have a good therapeutic effect on phosgene-induced ALI. We transduced MSCs with Hsp70 and then we tested the function of the transduced MSCs. Sprague Dawley rats inhaled phosgene in a closed container for 5 minutes. The transduced MSCs and MSCs were administered via the trachea immediately. Rats in each group were killed at 6, 24, and 48 hours after exposure. Compared to MSCs, MSCs overexpressed Hsp70 enhanced MSCs viability, antiapoptotic ability, and migration ability, and these effects disappeared when using the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway inhibitor. Furthermore, the results of pathological alterations improved. The lung wet-to-dry ratio declined. The lung injury index total protein content and total cells in bronchoalveolar lavage fluid (BALF) also declined. The level of tumor necrosis factor α declined and the level of interleukin-10 improved in BALF and serum. MSCs overexpressed Hsp70 can enhance the capacity and efficacy of MSCs in the treatment of phosgene-induced ALI and may be mediated through the PI3k/AKT signaling pathway. This article introduces a new approach to stem cell therapy for improving the efficacy of phosgene-induced ALI., (© 2020 Wiley Periodicals LLC.)

The possibility of adsorption of toxic phosgene gas (COCl 2 ) molecule on one of the nucleobase of DNA-adenine-has been analyzed using the first principle calculations based on density function theory. In accordance with the geometry of the nucleobase, two possible positions have been considered for effective adsorption of gas molecule. The calculations performed on adsorption energies suggest that the gas molecule is able to physisorb at both the considered positions with negligibly small values of charge transfer. The in-depth analysis of electron charge densities depicts that there is no orbital overlapping between the gas molecule and adenine. We observe a significant variation of transport properties of adenine-based molecular junction on adsorption of phosgene molecule while calculation the transport parameters at both the equilibrium as well as non-equilibrium. Also, the variation of HOMO-LUMO gap of adenine molecule on adsorption of phosgene leads to alteration of current and voltage, thus implying that adenine-based sensor can be effectively utilized to sense the presence of phosgene gas in a given environment. Small adsorption energies and recovery time suggest that the rate of desorption of phosgene is very high; thus, the proposed adenine sensor can be effectively used as a highly stable and selective reusable sensor.

Chloropicrin is a volatile and reactive chemical that has been utilized as a warfare agent and a pesticide to fumigate soil against insects, fungi and nematodes. It poses a health risk to humans and animals if inhaled. The main source of chloropicrin exposure is occupational and occurs during its manufacture, transport and fumigation. Chloropicrin is toxic via all routes of exposure but the main route of systemic exposure is inhalation of the ambient air. Thus, the toxicity mainly affects the respiratory system. After a low level exposure, the first sign is irritation of the upper respiratory tract and eyes. Irritation is mediated by the sensory nerve fibers, which coordinate further activation of various protective reflexes. Chloropicrin-induced irritation is generally reversible but can alter airway responsiveness to other inhalation toxicants. Severe exposures cause injuries in the respiratory tract, inflammation, and even life-threatening edema. Much of the chloropicrin-caused symptoms and toxicity in the respiratory system displays similarities with those evoked by chlorine, which is also a breakdown product of chloropicrin. This review summarizes the latest information on chloropicrin with emphasis on the toxicity in the respiratory system. The data indicates that oxidative stress, modification of macromolecules, mutations, dysfunctions of cell organelles and cell death are involved in acute chloropicrin-induced toxicity in the respiratory system., Competing Interests: Declaration of Competing Interest The authors declare that there are no conflicts of interest., (Copyright © 2020. Published by Elsevier B.V.)

Accidental phosgene exposure can result in acute lung injury (ALI). Mesenchymal stem cells (MSCs) have been found to alleviate phosgene-induced ALI. However, the mechanism of MSCs underlying such protective effect remains largely unexplored. Exosomes, important components of microenvironment, are closely associated with intercellular information transfer. In the present study, we isolated lung exosomes in rats after phosgene exposure by ultracentrifugation and explored their effects on MSCs in vitro. ALI exosomes were elliptical in shape and 50-200 nm in size. ALI exosomes could promote proliferation and migration of MSCs. Moreover, ALI exosomes increased the secretion of IL-10, leading to enhanced immunoregulatory properties of MSCs. The paracrine factors, VEGF, HGF, LL-37 and Ang-1, were also augmented by ALI exosomes. However, ALI exosomes had no effect on differentiation of MSCs towards lung alveolar cells. To identify the effective miRNAs in ALI exosomes, we performed miRNA profile analysis. MiR-28-5p was considered as a possible effective molecule. We further studied the effect of miR-28-5p on MSCs. MiR-28-5p mimic promoted proliferation, migration, immunomodulation of MSCs. MiR-28-5p mimic promoted the paracrine of VEGF, HGF, LL-37 and Ang-1. Besides, we explored molecular mechanism of miR-28-5p in MSCs. PI3K/Akt signaling pathway was found significantly augmented by miR-28-5p mimic, indicating the activation in this process. Taken together, our findings could help identify the effects of lung-derived exosomes on MSCs, and the effective molecule in exosomes, miR-28-5p, activated MSCs through PI3K/Akt signaling pathway., (Copyright © 2019 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

The toxic effects resulting from inhalation exposure depend on both the concentration (C) of the inhaled substance and the exposure duration (t), including the assumptions that the exposure-limiting toxic effect is linearly linked with the accumulated C × t (inhaled dose), and detoxification or compensatory responses diminishing this dose are negligible. This interrelationship applies for both constant and fluctuating concentrations and is usually expressed by the toxic load equation C n × t = constant effect (k). The toxic load exponent 'n' is derived from both C- and t-dependent exponents with C b2 ×t b3 = k with n = b 2 /b 3 . This model is taken as a fundamental basis for assessing the acute hazard posed by atmospheric releases of noxious substances, whether deliberate or accidental. Despite its universal use, especially for inhaled irritants, the toxicological significance of this mathematical construct is still discussed controversially. With n = 1 this equation is called Haber's rule. The underlying assumption is that the exposure-based calculated and the actually inhaled C b2 ×t b3 are identical. Unlike the calculated dose, the latter is dependent on the test species and its t-dependent change in respiratory minute volume (MV). The retention patterns of inhaled irritant vapors may differ in obligate nasal breathing rodents and oronasally breathing humans as well. Thus, due to the interdependence of n on both C, t and k, this mathematical construct generates a bioassay-specific 'n' which can hardly be considered as human-equivalent, especially following exposure to sensory irritants known to elicit reflex-related changes in MV. The C- and t-dependent impact on C n × t = k was analyzed with the sensory irritant n-butyl monoisocyanate and compared with t-dependent changes elicited by highly, moderately, and poorly water-soluble sensory irritants ammonia, toluene diisocyanate, and phosgene, respectively. This comparison reveals that n depends on several factors: In cases where MV is instantly and plateau-like depressed with onset of exposure, n appears to be most dependent on C b2 × MV whereas for a similar slower time-dependent response n becomes more dependent on MV × t b3 . For any ensuing risk characterization that focuses on acute non-lethal threshold C b2 × t b3 's, the sensory irritation-related depression in MV must be known to arrive at meaningful conclusions. In summary, both C n - and t-dependent dosimetry-related pitfalls may occur in acute bioassays on rodents following inhalation exposure to irritants. These must be identified and dealt with judiciously prior to translation to apparently similar human exposures. By default, extrapolations from one duration to another should start with that C n × t eliciting the least depression in MV with n = 1., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Phosgene is classified as a chemical warfare agent, yet data on its short-duration high concentration toxicity in a nose-only exposure rat model is sparse and inconsistent. Hence, an exposure system for short-term/high concentration exposure was developed and characterized. Herein, we report the median lethal concentration (LC 50 ) for a 10-min nasal exposure of phosgene in a 24-h rat survival model. Male Wistar rats (Envigo) weighing 180-210 g on the day of exposure, were exposed to phosgene gas via nose-only inhalation using a system specifically designed to allow the simultaneous exposure and quantification of phosgene. After 24 h, the surviving rats were euthanized, the lung/body mass ratio determined, and lung tissues analyzed for histopathology. Increased terminal airway edema in the lungs located primarily at the alveoli (resulting in an increased lung/body mass ratio) coincided with the observed mortality. An LC 50 value of 129.2 mg/m 3 for a 10-min exposure was determined. Furthermore, in agreement with other highly toxic compounds, this study reveals a LC 50 concentration value supportive of a nonlinear toxic load model, where the toxic load exponent is >1 ( n = 1.17). Thus, in line with other chemical warfare agents, phosgene toxicity is predicted to be more severe with short-duration, high-concentration exposures than long-duration, low-concentration exposures. This model is anticipated to be refined and developed to screen novel therapeutics against relevant short-term high concentration phosgene exposures expected from a terrorist attack, battlefield deployment, or industrial accident.e = 1.17). Thus, in line with other chemical warfare agents, phosgene toxicity is predicted to be more severe with short-duration, high-concentration exposures than long-duration, low-concentration exposures. This model is anticipated to be refined and developed to screen novel therapeutics against relevant short-term high concentration phosgene exposures expected from a terrorist attack, battlefield deployment, or industrial accident.

Phosgene (Carbonyl Chloride, COCl 2 ) remains an important chemical intermediate in many industrial processes such as combustion of chlorinated hydrocarbons and synthesis of solvents (degreasers, cleaners). It is a sweet smelling gas, and therefore does not prompt escape by the victim upon exposure. Supplemental oxygen and ventilation are the only available management strategies. This study was aimed to delineate the pathogenesis and identify novel biomarkers of acute lung injury post exposure to COCl 2 gas. Adult male and female C57BL/6 mice (20-25 g), exposed to COCl 2 gas (10 or 20 ppm) for 10 min in environmental chambers, had a dose dependent reduction in P a O 2 and an increase in P a CO 2 , 1 day post exposure. However, mortality increased only in mice exposed to 20 ppm of COCl 2 for 10 min. Correspondingly, these mice (20 ppm) also had severe acute lung injury as indicated by an increase in lung wet to dry weight ratio, extravasation of plasma proteins and neutrophils into the bronchoalveolar lavage fluid, and an increase in total lung resistance. The increase in acute lung injury parameters in COCl 2 (20 ppm, 10 min) exposed mice correlated with simultaneous increase in oxidation of red blood cells (RBC) membrane, RBC fragility, and plasma levels of cell-free heme. In addition, these mice had decreased plasmalogen levels (plasmenylethanolamine) and elevated levels of their breakdown product, polyunsaturated lysophosphatidylethanolamine, in the circulation suggesting damage to cellular plasma membranes. This study highlights the importance of free heme in the pathogenesis of COCl 2 lung injury and identifies plasma membrane breakdown product as potential biomarkers of COCl 2 toxicity., (Copyright © 2019 The Author(s). Published by Elsevier B.V. All rights reserved.)

Phosgene-induced acute lung injury (ALI) is characterized by a concentration x time (Cxt)-dependent increased pulmonary vascular permeability, phenotypically manifested as potentially life-threatening acute lung edema. In contemporary animal bioassays, the quantification of protein in bronchoalveolar lavage fluid (BAL) is taken as an unequivocal endpoint suggestive of disruption of alveolar barrier function. However, extravasated protein can only be a surrogate endpoint for assessing the extravascular fluid dynamics of the lung. This pathophysiological hallmark of ALI is diagnosed and quantified in vivo in humans by assessing the accumulation of excess extravascular lung water (EVLW). The Point of Departure (POD) of the Cxt relationship of this adverse outcome pathway should also constitute the basis for setting safe occupational and emergency response values. Unlike the EVLW approach, toxicology-based animal models utilize postmortem analyses of total protein in BAL and lung weights as the basis for human risk assessment. With either approach, it remains difficult to unequivocally evaluate pulmonary edema in terms of etiopathology and specificity, i.e., cardiogenic and hydrostatic versus increased permeability edema. The objective of this paper is to retrospectively analyze the clinical scoring of the severity grades of in vivo EVLWs from humans with the respective postmortem biomarkers BAL protein and collagen versus wet lung weights in rats and dogs exposed by inhalation to phosgene gas. Despite the different methodological approaches taken in humans and animals, the EVLW-based predicted thresholds for the onset of pulmonary edema and potentially life-threatening severe pulmonary edema were in remarkable agreement. Data from dogs appear to more aptly reflect the human etiopathology and should be given preference over data from rodents. Especially in rats, elevations in BAL protein may lead to a marked overestimation of the edematous potency of phosgene due to secreted protein into airways. In summary, increased lung weight in rats and dogs scaled favorably with the human-EVLW and was shown to be the biomarker of choice for the scaling lung edema. Caution is advised when using BAL protein in isolation as a surrogate endpoint of pulmonary edema., (Copyright © 2019 Elsevier B.V. All rights reserved.)

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/m 3 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.

Phosgene Oxime (CX, Cl 2 CNOH), a halogenated oxime, is a potent chemical weapon that causes immediate acute injury and systemic effects. CX, grouped together with vesicating agents, is an urticant or nettle agent with highly volatile, reactive, corrosive, and irritating vapor, and has considerably different chemical properties and toxicity compared to other vesicants. CX is absorbed quickly through clothing with faster cutaneous penetration compared to other vesicating agents causing instantaneous and severe damage. For this reason, it could be produced as a weaponized mixture with other chemical warfare agents to enhance their deleterious effects. The immediate devastating effects of CX and easy synthesis makes it a dangerous chemical with both military and terrorist potentials. Although CX is the most potent vesicating agent, it is one of the least studied chemical warfare agents and the pathophysiology as well as long term effects are largely unknown. CX exposure results in immediate pain and inflammation, and it mainly affects skin, eye and respiratory system. There are no antidotes available against CX-induced injury and the treatment is only supportive. This review summarizes existing knowledge regarding exposure, toxicity and the probable underlying mechanisms of CX compared to other important vesicants' exposure., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Objective: To investigate the effects of methylprednisolone on NOD-like receptor hot protein domain-associated protein 3 (NLRP3) inflammasome in phosgene-induced acute lung injury. Methods: Rats were randomly divided into four groups, 10 rats in Air group (inhalation of air of the same volume as the phosgene group) , 10 rats in Phosgene group (inhalation of 8.33 mg/L with 100% purity phosgene for 5 min) , 10 rats in Saline control group (inhalation of the same dose of phosgene and 2 mg/kg saline via tail vein injection one hour later) , 10 rats in MP group (inhalation of the same dose of phosgene and 2 mg/kg MP via tail vein injection one hour later) . The specimens of serum, bronchoalveolar lavage fluid (BALF) and lung tissue were collected after 6h. Morphological changes were observed by HE staining. The expression of NLRP3 in the lung of four groups was detected by immunohistochemistry. NLRP3、ASC and caspase-1 expression in the lung tissue was quantified by Western blot. Reverse transcription-polymerase chain reaction (RT-PCR) were used to detect the expression of NLRP3、ASC and caspase-1 mRNA in the lung tissue. The concentrations of IL-1β、IL-18 and IL-33 in the serum and BALF were measured by enzyme-linked immunosorbent assay. Results: We successfully replicated the model of phosgene-induced ALI in rats. Morphological of HE staining after phosgene exposure to 6 h observed inflammatory cell infiltration in lung tissue in Phosgene group. Immunohistochemical staining results showed that there were many NLRP3 positive cells in lung tissue in Phosgene group. The levels of NLRP3, caspase-1 mRNA and protein expression in lung were significantly increased ( P <0.05) in Phosgene group compared with Air group; compared with Phosgene group, The levels of NLRP3 and caspase-1 mRNA and protein expression in MP group were significantly decreased ( P <0.05) . Compared with Air group, The levels IL-1β、IL-18 and IL-33 mRNA protein expression in the serum and BALF were significantly increased ( P <0.05) in Phosgene group. Compared with Phosgene group, The levels IL-1β、IL-18 and IL-33 mRNA protein expression in the serum and BALF were significantly decreased ( P <0.05) in MP group. Conclusion: Methylprednisolone can effectively protect the rats from phosgene-induced acute lung injury by inhibiting the expression of the NLRP3 inflammasome and reducing the release of inflammatory factors such as interleukin-1β (IL-1β) mediated by it.

The toxic industrial chemical (TIC 1 ) phosgene remains an important chemical intermediate in many industrial processes. Inhalation of phosgene can cause an acute lung injury (ALI) which, in severe cases may result in death. There are currently no effective pharmacological therapies or evidence-based treatment guidelines for managing exposed individuals. N-acetylcysteine (NAC) is a commercially available drug licensed in the UK and elsewhere for the treatment of paracetamol (acetaminophen) overdose. It has a number of mechanisms of action which may provide therapeutic benefit for the treatment of phosgene-induced ALI. It has previously been shown to provide therapeutic efficacy against the lung damaging effects of sulfur mustard vapour exposure, when given by the inhaled route, in the pig (Jugg et al., 2013). Our research objective was to determine whether inhaled NAC might also be therapeutic for other chemicals, in this case, phosgene. This study has demonstrated that multiple nebulised doses, administered from 30 min after exposure of terminally anaesthetised pigs to phosgene, is not an effective therapy when administered at the times and doses employed in this study. There remains no pharmacological treatment for phosgene-induced lung injury., (Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.)

Objective: Angiopoietin-1 (Ang1) is reported to have the ability to attenuate endothelial permeability and inflammation during the stress condition and is considered to play a critical role in vascular stabilization. The aim of this study was to investigate the mechanisms involved in the protective effects of adenovirus-delivered Ang1 in phosgene-induced acute lung injury (ALI)., Methods: ALI was induced in rats by phosgene exposure at 8.33 g/m 3 for 5 min, followed by an intravenous injection of adenovirus-Ang1 (Ad/Ang1). The histologic changes of the lung were evaluated with H&E staining. The levels of cytokines in the serum and bronchoalveolar lavage fluid (BALF) were determined by ELISA. NLRP3 inflammasome activation was assessed with immunohistochemistry, RT-PCR, Western blotting and TUNEL staining., Results: Histologic analyses suggested that reduced severity in phosgene-induced ALI with Ad/Ang1 treatment. Reduced levels of IL-1β, IL-18 and IL-33 were found in both serum and BALF samples from Ad/Ang1-treated ALI rats induced by phosgene. Moreover, immunohistochemistry analysis revealed that Ad/Ang1 treatment inhibited the NLRP3 inflammasome activation. Decreased mRNA and protein levels of NLRP3 and caspase-1 were found in phosgene-exposed rats treated with Ad/Ang1. In addition, TUNEL staining indicated a decrease in pyroptosis in phosgene-exposed rats treated with Ad/Ang1., Conclusions: Ang1 exerts beneficial effects on phosgene-induced lung injury via inhibition of NLRP3 inflammasome activation. Disruption of NLRP3 inflammasome activation might be served as therapeutic modality for the treatment of phosgene-induced ALI.

Objective: To investigate changes of NLRP3 signal transduction pathway of acute lung injury induced by phosgene to analyze NLRP3-mediated IL-1β release inflammatory process in rats. Methods: Rats were randomly divided into two groups, 10 rats in the Air group that consists of the rats with air exposure, 10 rats in the Psg group that consists of the rats with phosgene exposure at 8.33 g/m(3) for 5 min. The specimens of serum, bronchoalveolar lavage fluid (BALF) and lung were collected after 6h. Morphological changes were observed by HE staining. The expression of NLRP3 in the lung of two groups was detected by immunohistochemistry. NLRP3、ASC and caspase-1 expression in the lung tissue was quantified by Western blot. Reverse transcription-polymerase chain reaction (RT-PCR) were used to detect the expression of NLRP3、ASC and caspase-1 mRNA in the lung tissue. The concentrations of IL-1β、IL-18 and IL-33 in the serum and BALF were measured by enzyme-linked immunosorbent assay. RT-PCR were used to detect the expression of IL-1β、IL-18 and IL-33 mRNA in the lung tissue. Results: We successfully replicated the model of phosgene-induced ALI in rats. Morphological of HE staining after phosgene exposure to 6 h observed inflammatory cell infiltration in lung tissue in Phosgene group. Immunohistochemical staining results showed that there were many NLRP3 positive cells in lung tissue in Phosgene group. The levels of NLRP3 and caspase-1 mRNA and protein expression in lung were significantly increased ( P <0.05) in Phosgene group, but no significant change was observed in lung ASC mRNA and protein expression ( P >0.05) . Compared with Air group, the serum, BALF and lung tissue of IL-1β、IL-18 and IL-33 mRNA and protein expression were significantly increased ( P <0.01) in Phosgene group. Conclusion: NLRP3-mediated inflammatory response probably involved in the process of the phosgene, so it maybe one of the pathogenesis of acute lung injury.

Phosgene Oxime (CX), an urticant or nettle agent categorized as a vesicant, is a potential chemical warfare and terrorist weapon. Its exposure can result in widespread and devastating effects including high mortality due to its fast penetration and ability to cause immediate severe cutaneous injury. It is one of the least studied chemical warfare agents with no effective therapy available. Thus, our goal was to examine the acute effects of CX following its cutaneous exposure in SKH-1 hairless mice to help establish a relevant injury model. Results from our study show that topical cutaneous exposure to CX vapor causes blanching of exposed skin with an erythematous ring, necrosis, edema, mild urticaria and erythema within minutes after exposure out to 8h post-exposure. These clinical skin manifestations were accompanied with increases in skin thickness, apoptotic cell death, mast cell degranulation, myeloperoxidase activity indicating neutrophil infiltration, p53 phosphorylation and accumulation, and an increase in COX-2 and TNFα levels. Topical CX-exposure also resulted in the dilatation of the peripheral vessels with a robust increase in RBCs in vessels of the liver, spleen, kidney, lungs and heart tissues. These events could cause a drop in blood pressure leading to shock, hypoxia and death. Together, this is the first report on effects of CX cutaneous exposure, which could help design further comprehensive studies evaluating the acute and chronic skin injuries from CX topical exposure and elucidate the related mechanism of action to aid in the identification of therapeutic targets and mitigation of injury., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Therapeutic development against exposure to toxic gases is hindered by the lack of appropriate models to evaluate candidate compounds prior to animal efficacy studies. In this study, an in vitro, air-liquid interface exposure model has been tested to examine its potential application for screening treatments for phosgene (carbonyl chloride)-induced pulmonary injury. Epithelial cultures on Transwell ® inserts, combined with a Vitrocell ® exposure apparatus, provided a physiologically relevant exposure environment. Differentiated human bronchial epithelial (16HBE) cultures were exposed for 8 min to phosgene ranging from 0 to 64 ppm and assessed for changes in transepithelial electrical resistance (TEER, epithelial barrier integrity), cellular viability (XTT) and post-exposure (PE) cellular metabolic energy status. Exposure to phosgene concentrations ≥8 ppm caused dose-dependent and significant decreases in TEER and XTT which did not recover within 24-h PE. In addition, at 64 ppm the rate of oxidative glutamine metabolism was significantly inhibited at 6 and 24 h after exposure. Glycolytic activities (glucose utilization and lactate production) were also inhibited, but to a lesser extent. Decreased glycolytic function can translate to insufficient energy sources to counteract barrier function failure. Consistent and sensitive markers of phosgene exposure were TEER, cell viability and decreased metabolism. As such, we have assessed an appropriate in vitro model of phosgene inhalation that produced quantifiable alterations in markers of lung cell metabolism and injury in human airway epithelial cells. Data indicate the suitability of this model for testing classes of anti-edemagenic compounds such as corticosteroids or phosphodiesterase inhibitors for evaluating phosgene therapeutics.

An increase in epithelial cell permeability has been proposed to contribute to phosgene-induced acute lung injury (ALI). However, no specific and effective means for blocking increases in permeability are currently available. Cell-based therapy using bone marrow-derived mesenchymal stem cells (MSCs) is an attractive new approach. Canonical wnt/β-catenin signaling has been demonstrated to contribute to both epithelial cell injury and repair mechanisms in ALI. The goal of our study was to determine the effects of MSCs on epithelial permeability in phosgene-induced ALI in Sprague-Dawley (SD) rats and identify changes in major components of the wnt3a/β-catenin signaling pathway during this process. Epithelial cell permeability was evaluated by measuring total protein, albumin, keratinocyte growth factor, and occludin in bronchoalveolar lavage fluid and lung tissue. MSCs-harboring lentiviral vectors expressing green fluorescent protein (GFP) were used to determine rates of MSC engraftment at injured sites. Lung tissue was excised to evaluate changes in the levels of proteins that function in wnt3a/β-catenin signaling, including wnt3a, total β-catenin, non-phosphorylated-Ser33/37/Thr41 β-catenin, axin2, and cyclin D1 by western blot analysis. Because TGF-β1 and wnt5a can inhibit canonical wnt/β-catenin signaling, we also measured levels of TGF-β1 and wnt5a by western blotting., Conclusions: (1) TGF-β1 and wnt5a expression correlated with inhibition of wnt3a/β-catenin signaling in our phosgene-induced ALI model and (2) exogenously supplied MSCs homed to sites of lung injury and reduced epithelial permeability likely by blocking TGF-β1- and wnt5a-mediated inhibition of wnt3/β-catenin signaling.

Phosgene (CG), a toxic inhalation and industrial hazard, causes bronchoconstriction, vasoconstriction and associated pathological effects that could be life threatening. Ion channels of the transient receptor potential (TRP) family have been identified to act as specific chemosensory molecules in the respiratory tract in the detection, control of adaptive responses and initiation of detrimental signaling cascades upon exposure to various toxic inhalation hazards (TIH); their activation due to TIH exposure may result in broncho- and vasoconstriction. We studied changes in the regulation of intracellular free Ca(2+) concentration ([Ca(2+)]i) in cultures of human bronchial smooth muscle cells (BSMC) and human pulmonary microvascular endothelial cells (HPMEC) exposed to CG (16ppm, 8min), using an air/liquid interface exposure system. CG increased [Ca(2+)]i (p<0.05) in both cell types, The CG-induced [Ca(2+)]i was blocked (p<0.05) by two types of TRP channel blockers, SKF-96365, a general TRP channel blocker, and RR, a general TRPV (vanilloid type) blocker, in both BSMC and HPMEC. These effects correlate with the in vivo efficacies of these compounds to protect against lung injury and 24h lethality from whole body CG inhalation exposure in mice (8-10ppm×20min). Thus the TRP channel mechanism appears to be a potential target for intervention in CG toxicity., (Published by Elsevier Ireland Ltd.)

Biomarkers have gained immense scientific interest and clinical value in the practice of medicine. With unprecedented advances in high-throughput technologies, research interest in identifying novel and customized disease biomarkers for early detection, diagnosis, or drug responses is rapidly growing. Biomarkers can be identified in different levels of molecular biomarkers, networks biomarkers and dynamical network biomarkers (DNBs). The latter is a recently developed concept which relies on the idea that a cell is a complex system whose behavior is emerged from interplay of various molecules, and this network of molecules dynamically changes over time. A DNB can serve as an early-warning signal of disease progression, or as a leading network that drives the system into the disease state, and thus unravels mechanisms of disease initiation and progression. It is therefore of great importance to identify DNBs efficiently and reliably. In this work, the problem of DNB identification is defined as a multi-objective optimization problem, and a framework to identify DNBs out of time-course high-throughput data is proposed. Temporal gene expression data of a lung injury with carbonyl chloride inhalation exposure has been used as a case study, and the functional role of the discovered biomarker in the pathogenesis of lung injury has been thoroughly analyzed.

Introduction: Chemical weapons dumped into the ocean for disposal in the twentieth century pose a continuing environmental and human health risk., Objective: In this review we discuss locations, quantity, and types of sea-dumped chemical weapons, related environmental concerns, and human encounters with sea-dumped chemical weapons., Methods: We utilized the Ovid (http://ovidsp.tx.ovid.com) and PubMed (http://www.pubmed.org) search engines to perform MEDLINE searches for the terms 'sea-dumped chemical weapons', 'chemical warfare agents', and 'chemical munitions'. The searches returned 5863 articles. Irrelevant and non-English articles were excluded. A review of the references for these articles yielded additional relevant sources, with a total of 64 peer-reviewed articles cited in this paper. History and geography of chemical weapons dumping at sea: Hundreds of thousands of tons of chemical munitions were disposed off at sea following World War II. European, Russian, Japanese, and United States coasts are the areas most affected worldwide. Several areas in the Baltic and North Seas suffered concentrated large levels of dumping, and these appear to be the world's most studied chemical warfare agent marine dumping areas. Chemical warfare agents: Sulfur mustard, Lewisite, and the nerve agents appear to be the chemical warfare agents most frequently disposed off at sea. Multiple other type of agents including organoarsenicals, blood agents, choking agents, and lacrimators were dumped at sea, although in lesser volumes. Environmental concerns: Numerous geohydrologic variables contribute to the rate of release of chemical agents from their original casings, leading to difficult and inexact modeling of risk of release into seawater. Sulfur mustard and the organoarsenicals are the most environmentally persistent dumped chemical agents. Sulfur mustard in particular has a propensity to form a solid or semi-solid lump with a polymer coating of breakdown products, and can persist in this state on the ocean floor for decades. Rates of solubility and hydrolysis and levels of innate toxicity of a chemical agent are used to predict the risk to the marine environments. The organoarsenicals eventually breakdown into arsenic, and thus present an indefinite timeline for contamination. Generally, studies assaying sediment and water levels of parent chemical agents and breakdown products at dumpsites have found minimal amounts of relevant chemicals, although arsenic levels are typically higher in dumpsites than reference areas. Studies of marine organisms have not shown concerning amounts of chemical agents or breakdown products in tissue, but have shown evidence of chronic toxicity. There is believed to be minimal risk posed by seafood consumption. Microbiota assays of dumpsites are significantly altered in species composition compared to reference sites, which may imply unseen but significant changes to ecosystems of dumpsites. Human health concerns: The major human health risk at this time appears to arise from acute exposure to an agent by either accidental recovery of a chemical weapon on a fishing vessel, or by munitions washed ashore onto beaches., Conclusions: Improving technology continues to make the deep sea more accessible, thus increasing the risk of disturbing munitions lying on or buried in the seabed. Pipe laying, cable burying, drilling, scuba diving, trawling, and undersea scientific research are the activities posing the most risk. The long-term threat to the benthic habitat via increased arsenic concentrations, shifts in microbiota speciation, and chronic toxicity to vertebrates and invertebrates is not currently understood. The risk to the environment of massive release via disturbance remains a distinct possibility. Terrorist recovery and re-weaponization of chemical agents is a remote possibility.

Phosgene exposure via an industrial or warfare release produces severe acute lung injury (ALI) with high mortality, characterized by massive pulmonary edema, disruption of epithelial tight junctions, surfactant dysfunction, and oxidative stress. There are no targeted treatments for phosgene-induced ALI. Previous studies demonstrated that nitric oxide synthase 2 (NOS-2) is upregulated in the lungs after phosgene exposure; however, the role of NOS-2 in the pathogenesis of phosgene-induced ALI remains unknown. We previously demonstrated that NOS-2 expression in lung epithelium exacerbates inhaled endotoxin-induced ALI in mice, mediated partially through downregulation of surfactant protein B (SP-B) expression. Therefore, we hypothesized that a selective NOS-2 inhibitor delivered to the lung epithelium by inhalation would mitigate phosgene-induced ALI. Inhaled phosgene produced increases in bronchoalveolar lavage fluid protein, histologic lung injury, and lung NOS-2 expression at 24 h. Administration of the selective NOS-2 inhibitor 1400 W via inhalation, but not via systemic delivery, significantly attenuated phosgene-induced ALI and preserved epithelial barrier integrity. Furthermore, aerosolized 1400 W augmented expression of SP-B and prevented downregulation of tight junction protein zonula occludens 1 (ZO-1), both critical for maintenance of normal lung physiology and barrier integrity. We also demonstrate for the first time that NOS-2-derived nitric oxide downregulates the ZO-1 expression at the transcriptional level in human lung epithelial cells, providing a novel target for ameliorating vascular leak in ALI. Our data demonstrate that lung NOS-2 plays a critical role in the development of phosgene-induced ALI and suggest that aerosolized NOS-2 inhibitors offer a novel therapeutic strategy for its treatment., (© The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Various therapeutic regimes have been proposed for treatment of phosgene-induced acute lung injury (P-ALI). Most of these treatments rely on late-stage supportive measures to maintain the oxygenation of the lung. This exploratory proof-of-concept study on Beagle dogs focused on protective positive end-expiratory pressure (PEEP) ventilation, initiated early at the yet asymptomatic stage after phosgene exposure. Conscious, spontaneously breathing dogs were head-only exposed to a potentially lethal inhalation dose of phosgene (870 ppm × min). Shortly after exposure, the dogs were anesthetized, intubated and then subjected to mechanical ventilation (PEEP; tidal volume (VT)=10-12 mL/kg body weight, 40 breaths/min) at 0, 4, or 12 cm H2O over a post-exposure period of 8h (one dog per setting). For reference, one additional dog received the same dose of phosgene without anesthesia and mechanical ventilation. Time-course changes of hematocrit, leukocytes, and thrombocytes were determined in peripheral blood. At necropsy, changes lung weights, bronchoalveolar lavage, and histology were used to assess the efficacy of treatment. The most salient outcome in the non-ventilated dog was a time-related hemoconcentration and leukocytosis and autopsy findings suggestive of pulmonary congestion and edema. The pulmonary epithelium of the major airways was generally intact; however, in their lumen inflammatory cells, cellular debris and mucus were present. Relative to the dog receiving no intervention, the lung edema was markedly alleviated by PEEP at both 4 and 12 cm H2O but not at 0 cm H2O PEEP. In summary, the time-dependent progression into a life-threatening pulmonary edema can effectively be suppressed by protective, low-pressure PEEP when implemented early enough after exposure to phosgene. However, due to the exploratory nature of this study, the findings may suggest an association between PEEP and protection from pulmonary edema. However, definite conclusions and recommendations cannot be made yet based upon the small sample size and the limited variables examined., (Copyright © 2014. Published by Elsevier GmbH.)

Context: Phosgene's primary mode of action is as a pulmonary irritant characterized by its early latent phase where life-threatening, non-cardiogenic pulmonary edema is typically observed 6-24 h post-exposure., Objective: To develop an inhaled phosgene acute lung injury (ALI) model in C57BL/6 mice that can be used to screen potential medical countermeasures., Methods: A Cannon style nose-only inhalation exposure tower was used to expose mice to phosgene (8 ppm) or air (sham). An inhalation lethality study was conducted to determine the 8 ppm median lethal exposure (LCt50) at 24 and 48 h post-exposure. The model was then developed at 1.2 times the 24 h LCt50. At predetermined serial sacrifice time points, survivors were euthanized, body and lung weights collected, and lung tissues processed for histopathology. Additionally, post-exposure clinical observations were used to assess quality of life., Results and Discussion: The 24-hour LCt50 was 226 ppm*min (8 ppm for 28.2 min) and the 48-hour LCt50 was 215 ppm*min (8 ppm for 26.9 min). The phosgene exposed animals had a distinct progression of clinical signs, histopathological changes and increased lung/body weight ratios. Early indicators of a 1.2 times the 24-hour LCt50 phosgene exposure were significant changes in the lung-to-body weight ratios by 4 h post-exposure. The progression of clinical signs and histopathological changes were important endpoints for characterizing phosgene-induced ALI for future countermeasure studies., Conclusion: An 8 ppm phosgene exposure for 34 min (1.2 × LCt50) is the minimum challenge recommended for evaluating therapeutic interventions. The predicted higher mortality in the phosgene-only controls will help demonstrate efficacy of candidate treatments and increase the probability that a change in survival rate is statistically significant.

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.

This study compares changes in cardiopulmonary function, selected endpoints in exhaled breath, blood, and bronchoalveolar lavage fluid (BAL) following a single, high-level 30-min nose-only exposure of rats to chlorine and phosgene gas. The time-course of lung injury was systematically examined up to 1-day post-exposure with the objective to identify early diagnostic biomarkers suitable to guide countermeasures to accidental exposures. Chlorine, due to its water solubility, penetrates the lung concentration-dependently whereas the poorly water-soluble phosgene reaches the alveolar region without any appreciable extent of airway injury. Cardiopulmonary endpoints were continually recorded by telemetry and barometric plethysmography for 20h. At several time points blood was collected to evaluate evidence of hemoconcentration, changes in hemostasis, and osteopontin. One day post-exposure, protein, osteopontin, and cytodifferentials were determined in BAL. Nitric oxide (eNO) and eCO2 were non-invasively examined in exhaled breath 5 and 24h post-exposure. Chlorine-exposed rats elaborated a reflexively-induced decreased respiratory rate and bradycardia whereas phosgene-exposed rats developed minimal changes in lung function but a similar magnitude of bradycardia. Despite similar initial changes in cardiac function, the phosgene-exposed rats showed different time-course changes of hemoconcentration and lung weights as compared to chlorine-exposed rats. eNO/eCO2 ratios were most affected in chlorine-exposed rats in the absence of any marked time-related changes. This outcome appears to demonstrate that nociceptive reflexes with changes in cardiopulmonary function resemble typical patterns of mixed airway-alveolar irritation in chlorine-exposed rats and alveolar irritation in phosgene-exposed rats. The degree and time-course of pulmonary injury was reflected best by eNO/eCO2 ratios, hemoconcentration, and protein in BAL. Increased fibrin in blood occurred only in chlorine-exposed rats 1-day post-exposure. Hence, the analysis of NO and CO2 in exhaled breath, including endpoints in blood mirroring changes in the peripheral to pulmonary fluid distribution, seem to be sensitive diagnostic endpoints readily available for early prognostic assessment of severity of injury and efficacy of any chosen countermeasure., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Objective: To investigate the dynamic changes of a group of cytokines in phosgene-induced lung injury and the function of different dose of ulinastatin through animal experiment., Methods: 104 male SD rats were randomly assigned into the control group, ulinastatin control group, phosgene treatment groups and different dose of ulinastatin intervention groups, 8 rats each group. Treatment groups were dynamic constant exposure in phosgene, and immediately injected ulinastatin intraperitoneal, and then the experimental animal, the lung tissue biopsy, lung wet/dry ratio, RT-PCR detection, the plasma for detection of Bio-Plex 18 cytokines., Results: Compared with the control group, plasma concentrations of IL-1α, IL-6, GM-CSF, TNF-α, INF-γ, MIP-3α, VEGF were increased significantly first (2 h), and gradually decreased with the passage of time , the difference was statistically significant (P < 0.05). Plasma concentrations of IL-4, IL-10 were decreased earlier (2h, 6 h) and increased later (24 h) (P < 0.05). The change of plasma concentration of IL-13 was not obvious earlier (2 h) and still rising later (24h), the difference was statistically significant (P < 0.05). After drug intervention, the levels of pro-inflammatory cytokines declined and the levels of anti-inflammatory cytokines raise by different degrees at different times in ulinastatin intervention groups, the difference was statistically significant. The degree of lung injury was improved than the phosgene treatment groups and better in high dose of ulinastatin intervention group. The expression of IL-10, IL-4, IL-13-mRNA of tissue increased in accordance with plasma results., Conclusion: A group of cytokines are dynamicly changed in phosgene-induced lung injury by time. High dose of ulinastatin can improved phosgene-induced lung injury, regulate the synthesis and release of inflammatory cytokines and inhibit inflammatory react in a dose-dependent manner.

Phosgene (CG) is an industrial chemical used to make plastics, rubbers, dyestuff, and pesticides. Although the inhalation of CG is relatively uncommon, its accidental exposure can lead to acute lung injury (ALI). Ulinastatin, a urinary trypsin inhibitor, has been emerged to use for the treatment of acute inflammatory state of a number of organs including the lung. In this study, we examined the pathogenic changes in the lungs after the inhalation of CG gas and also examined the effect of ulinastatin treatment in reversing these changes in rats. We found that the rats exposed to CG gas at a dose of 5.0 g/m(3) for 5 min led to ALI after 6 h. The signs of lung injury include pulmonary edema, hemorrhage, and cellular infiltration in pulmonary alveoli. In addition, interleukin-15 (IL-15) and intercellular adhesion molecule-1 (ICAM-1) were significantly increased in CG-inhaled animals. Ulinastatin administration at 1 h postexposure significantly reduced the intensity of all the pathological changes in the lungs of these CG-exposed animals. Ulinastatin at a dose of 400 U/g was shown to decrease the total number of cells in bronchoalveolar lavage fluid and the levels of IL-15 and ICAM-1 in the serum. We also found that the structure of the lung was protected by ulinastatin treatment. Thus, our data suggest that ulinastatin can be used as an effective drug for the treatment of CG-induced ALI. The serum levels of IL-15 and ICAM-1 can be used as the markers of lung injury after exposure to CG and may also serve as useful therapeutic targets at an early stage. The effects of long-term treatment of ulinastatin and the mechanisms by which ulinastatin decreases the infiltration of blood cells and reduces cytokines need further investigation., (© The Author(s) 2012.)

Objective: To investigate the effect of melatonin (MT) on p38 mitogen-activated protein kinase (MAPK) signaling pathway in rats with phosgene-induced lung injury., Methods: Fifty specific pathogen-free male Sprague-Dawley rats were randomly divided into phosgene inhalation group, air control group, saline control group, MT treatment group, and SB203580 (specific inhibitor of p38 MAPK) group, with 10 mice in each group. All groups except the air control group were exposed to phosgene, and the animals were sacrificed 6 h later. Lung wet/dry weight (W/D) ratio and the content of malondialdehyde (MDA) and nitric oxide (NO) and activity of myeloperoxidase (MPO) in bronchoalveolar lavage fluid (BALF) were measured. The qualitative and quantitative expression of p38 MAPK and phospho-p38 MAPK (p-p38) was measured by immunohistochemistry (IHC) and Western blot, respectively. Inducible nitric oxide synthase (iNOS) level in lung tissue was determined by Western blot., Results: Compared with the air control group, the phosgene inhalation group had significantly increased lung W/D ratio and neutrophil count in BALF (P < 0.01); the MT treatment group had significantly lower neutrophil count and lung W/D ratio than the phosgene inhalation group (P < 0.05). IHC demonstrated that the air control group had relatively weak expression of p-p38 in lung tissue; the expression of p-p38 was significantly up-regulated after phosgene inhalation, and it was mainly distributed in infiltrating inflammatory cells and vascular endothelial cells, positive in the cytoplasm and nucleus of many cells. The distribution of p-p38-positive cells in the MT treatment and SB203580 groups was similar to that in the phosgene inhalation group, but the MT treatment and SB203580 groups had a significantly reduced number of cells with p-p38-positive nuclei and a significantly reduced intensity of p-p38 expression signals. The phosgene inhalation group had significantly increased content of MDA and NO and activity of MPO compared with the air control group (P < 0.01); the MT treatment and SB203580 groups had significantly reduced content of MDA and NO and activity of MPO compared with the phosgene inhalation group (P < 0.05), but had higher content of MDA and NO and activity of MPO than the air control group. The Western blot showed that the phosgene inhalation group had significantly increased expression of iNOS and p-p38 compared with the air control group (P < 0.01); the MT treatment and SB203580 groups had lower expression of iNOS and p-p38 than the phosgene inhalation group (P < 0.05)., Conclusion: MT and SB203580 have a significant protective effect in rats with phosgene-induced lung injury, and the mechanism may be associated with scavenging free radicals and inhibiting activation of p38 MAPK and expression of iNOS.

Objective: To investigate the effects of adenovirus-delivered angiopoietin-1 siRNA (Ad. Ang-1siRNA) on the expression of matrix metalloproteinase-2, 9 (MMP-2, 9) and tissue inhibitor of metallopro-teinase-1 (TIMP-1) in rats with acute lung injury (ALI) induced by phosgene (Psg)., Methods: We first established a rat model of Psg-induced acute lung injury (ALI). The rats were randomly divided into 6 groups: air control group with exposure to air, air+adenovirus (air+Ad) group with caudal vein injection of 1×10(8) pfu/ml adenovirus 1 h after air exposure, air+Ad/Ang1 group with caudal vein injection of 1×10(8) pfu/ml Ad.Ang-1siRNA 1 h after air exposure, Psg group with exposure to 8.33 mg/L Psg (purity 100%, of the same volume as the inhaled air in the air control group) for 5 min, Psg+Ad group with caudal vein injection of 1×10(8) pfu/ml adenovirus 1 h after exposure to the same dose of Psg, and Psg+Ad/Ang1 group with caudal vein injection of 1×10(8) pfu/ml Ad.Ang-1siRNA 1 h after exposure to the same dose of Psg. Serum, bronchoalveolar lavage fluid (BALF), and lung tissue were collected 36 h after exposure. The protein expression of Ang-1, MMP-2, 9, and TIMP-1 in serum and BALF was determined by double-antibody sandwich ELISA. RT-PCR was used to determine the mRNA levels of Ang-1, MMP-2, 9, and TIMP-1 in lung tissue. The protein expression of MMP-2, 9 and TIMP-1 in lung tissue was determined by Western blot., Results: A rat model of Psg-induced ALI was successfully established. The levels of MMP-2, 9 in serum, BALF, and lung tissue were significantly increased in the Psg group and Psg+Ad/Ang1 group as compared with the control group (P<0.01); no significant change was observed in serum TIMP-1 protein expression (P>0.05); interestingly, TIMP-1 protein expression in BALF and lung tissue was significantly increased (P<0.01). Compared with the Psg group, the Psg+Ad/Ang1 group showed a significant decrease in MMP-2, 9 expression in BALF, serum, and lung tissue (P<0.05), but no significant change in protein expression of TIMP-1 was discovered (P>0.05)., Conclusion: Ad.Ang-1siRNA has a potential beneficial effect in rats with Psg-induced ALI through inhibition of MMP-2, 9 expression, but has no significant effect on the expression of TIMP-1.