0
Original Research: Occupational and Environmental Lung Disease |

Solnatide Demonstrates Profound Therapeutic Activity in a Rat Model of Pulmonary Edema Induced by Acute Hypobaric Hypoxia and Exercise OPEN ACCESS

Qiquan Zhou, MD; Dong Wang, MSc; Yunsheng Liu, PhD; Xiaohong Yang, MSc; Rudolf Lucas, PhD; Bernhard Fischer, PhD
Author and Funding Information

FUNDING/SUPPORT: The authors have reported to CHEST that no funding was received for this study.

aDepartment of High Altitude Geographical and High Altitude Disease, College of High Altitude Military Medicine, Third Military Medical University, and Key Laboratory of High Altitude Medicine, Ministry of Education, Chongqing, China

bVascular Biology Center, Division of Pulmonary Medicine, Medical College of Georgia, Augusta University, GA

cAPEPTICO Research and Development, Vienna, Austria

CORRESPONDENCE TO: Bernhard Fischer, PhD, APEPTICO, Mariahilferstr. 136, 1150 Vienna, Austria


Copyright 2016, The Authors. All Rights Reserved.


Chest. 2017;151(3):658-667. doi:10.1016/j.chest.2016.10.030
Text Size: A A A
Published online

Background  The synthetic peptide solnatide is a novel pharmacologic agent that reduces extravascular lung water, blunts reactive oxygen species production, and improves lung function due to its ability to directly activate the epithelial sodium channel. The goal of this study was to investigate the effect of solnatide in pulmonary edema induced by acute hypobaric hypoxia and exercise in rats, which is considered a model for high-altitude pulmonary edema.

Methods  Sprague-Dawley rats were assigned to low-altitude control and eight treatment groups. Animals of all groups were subjected to exhaustive exercise in a hypobaric hypoxic environment simulating an altitude of 4,500 meters, followed by simulated ascent to 6,000 meters. After 48 h at 6,000 meters, rats were given sodium chloride, dexamethasone, aminophylline, p38 mitogen activated protein kinase inhibitor, and NOD-like receptor containing a pyrin domain 3 inhibitor, or one of three different doses of solnatide, once daily for 3 consecutive days. After 3 days, arterial blood gas, BAL fluid, lung water content, and histologic and ultra-microstructure analyses were performed. Tight junction protein occludin was assayed by using immunohistochemistry.

Results  Rats treated with solnatide had significantly lower BAL fluid protein and lung water content than high-altitude control rats. Lungs of solnatide-treated rats were intact and showed less hemorrhage and disruption of the alveolar-capillary barrier than those of high-altitude control animals. Occludin expression was significantly higher in solnatide-treated animals, compared with high-altitude control, dexamethasone-, and aminophylline-treated animals.

Conclusions  Solnatide reduced pulmonary edema, increased occludin expression, and improved gas-blood barrier function during acute hypobaric hypoxia and exercise in rats. These results provide a rationale for the clinical application of solnatide to patients with pulmonary edema and exposure to a high-altitude hypoxic environment.

Figures in this Article

High-altitude pulmonary edema (HAPE), a life-threatening condition, affects otherwise healthy individuals rapidly ascending to altitudes > 3,000 meters.,,, The first detailed clinical description of HAPE can be found in a series of reports from the Mont Blanc expedition of 1891, published in Neue Zürcher Zeitung April 18 to 26, 1892. Four members of the expedition experienced HAPE, and the expedition’s medical physician died of HAPE at an altitude of 4,000 meters. HAPE is characterized by diffuse pulmonary edema with bloody foamy fluid present in the airways but no evidence of left ventricular failure., Histologic and microscopic examinations reveal hyaline membranes, arteriolar thrombi, pulmonary hemorrhages, bronchioles with inflammatory cell infiltration, infarcts, alveolar epithelial cell damage, pulmonary capillary cell connection gap widening, and thinning of the gas-blood barrier structure.

Early diagnosis of HAPE is essential to enable a prompt response. HAPE can be avoided by acclimatization over several days. However, in emergency circumstances, acclimatization is not a feasible option. Basic on-site treatment of HAPE consists of bed rest, oxygen inhalation, and IV administration of aminophylline, dexamethasone, and furosemide. HAPE remains the major cause of death related to high-altitude exposure. Accordingly, there is a pressing need for an effective therapy because the number of fatalities from HAPE increases annually and because the mountain tourism industry is rapidly expanding.,

The synthetic peptide, solnatide, whose molecular structure mimics the lectin-like domain of human tumor necrosis factor (TNF), is a potential drug candidate to treat HAPE. Solnatide activates the lung epithelial sodium channel (ENaC), located apically in alveolar epithelial cells, by directly binding to the crucial α-subunit of the channel, thus enhancing sodium ion uptake from the alveolar space across the alveolar cell membrane.,,, Earlier studies using rodent models of flooded lungs indicated the capacity of solnatide to improve alveolar fluid clearance., Solnatide reduced the extravascular lung water index and improved lung function in trauma-induced pulmonary edema in pigs, as well as improved oxygenation and blunt reactive oxygen species (ROS) production in a rat lung transplantation model. The safety and efficacy of orally inhaled solnatide aerosol have been reported in healthy volunteers and in two interventional clinical studies of acute lung dysfunction., It has also been shown that the ENaC activity is decreased under hypoxic conditions in cultured rat alveolar epithelial cells and in rodent models in vivo.,,

The current formulation of solnatide as an aqueous aerosol allows oral inhalation into the lungs, thus enabling it to rapidly reach its target and activate ENaC in the alveolar epithelium. In addition, a dry powder formulation for use with a dry powder inhaler device has been developed, allowing solnatide administration in remote areas.

The goal of the present study was to evaluate the capacity of solnatide to reduce edema and improve lung barrier function in an acute hypobaric hypoxia rat model for pulmonary edema, which is a type of HAPE model. We assessed lung water content (LWC), protein content in BAL fluid (BALF), histology and ultra-microstructure of alveolar tissue, and expression of the tight junction protein occludin. We also evaluated the potential antiinflammatory effects of solnatide.

Animals

Adult Sprague-Dawley rats were randomly allocated to groups (30 animals per group) as shown in Table 1. All animal experiments were conducted according to the Declaration of Helsinki conventions for the use and care of animals.

Table Graphic Jump Location
Table 1 Rodent Model of HAPE: Experimental Groups and Treatment Regimens
a Animals of all experimental groups were subject to exhaustive exercise.
b Otsuka Pharmaceutical Co, Ltd.
c Henan Hong Pharmaceutical Co Ltd.

APH = high-altitude animals treated with solnatide high concentration; APM = high-altitude animals treated with solnatide medium concentration; APS = high-altitude animals treated with solnatide low concentration; DMT = high-altitude animals treated with dexamethasone; HAPE = high-altitude pulmonary edema; PCT = plain control animals not exposed to hypobaric or hypoxic conditions; SCT = high-altitude control animals treated with sodium chloride.

Solnatide Peptide

Solnatide peptide was provided by APEPTICO.

HAPE Model

The HAPE model was based on a previously described method. Except for low-altitude control animals, all animals were exposed to acute hypobaric and hypoxic conditions in a high-altitude environment simulation chamber (DYC-2842T), highly equivalent to an altitude of 4,500 meters (at a velocity of 20 m/s within 4 min to 4,500 meters). Animals were subjected to exhaustive exercise by placing them on a treadmill at a speed of 15 m/min. After this exhaustive exercise phase, ascent to 6,000 meters was simulated and maintained until the end of the experimental schedule. After 48 h at 6,000 meters, animals were subjected to the treatment regimens shown in Table 1 over a 3-day period. Low-altitude control animals were also subjected to exhaustive exercise but were not exposed to the acute hypobaric-hypoxic condition.

Dissection and Collection of Samples

Following anesthesia with chloral hydrate, an abdominal incision was performed and blood drawn from the aorta abdominalis for analysis of cytokine levels. The chest cavity was opened and a cannula inserted into the trachea. BALF was withdrawn from the left lung after flushing it three times with sterile saline; pooled lavage fluid was centrifuged, and the supernatant was kept for determination of protein and cytokine content.

Analytical Procedures of Relevant Indicators

Following harvesting of samples for histologic examination, the remaining right lung tissue was quickly weighed (wet weight) and dried at 60°C for 96 h to constant weight. Calculation of the LWC percentage was made according to Elliott and Jasper, applying the following formula: LWC (%) = (wet weight – dry weight)/wet weight × 100%.

The protein content of BALF was determined by using the bicinchoninic assay with 96-well plates and a Synergy HT multimode microplate reader (BioTek Instruments). Cytokine detection of blood plasma and BALF was performed by using a radioimmunologic method (Zhongja Scientific Instruments) using detection kits (North Biotechnology Research Institute) for rat TNF, IL-1β, IL-6, and IL-8.

Lung Histology and Ultra-structure Analyses

Samples of right lung tissue were stored for 48 to 72 h in 4% paraformaldehyde for light microscopy or 2.5% glutaraldehyde for electron microscopy assessments. Lung tissue for light microscopy analysis was paraffin-embedded, sectioned, and stained with hematoxylin and eosin. Lung tissue for electron microscopy analysis was fixed in 1% lanthanum nitrate, rinsed twice with 0.1 M dimethyl sodium arsenate buffer, and post-fixed for 2 h with 1% osmium tetroxide. After rinsing twice with 0.1 mol/L of sodium dimethyl arsenic acid, specimens were dehydrated, sliced, contrasted by using uranium acetate and lead citrate, and examined by using transmission electron microscopy.

Occludin Detection

Expression of the tight junction protein occludin was determined by using a immunohistochemical detection method with occludin polyclonal rat antibody (Abcam). Occludin expression was determined by measuring the average optical density as a gray value of 10 randomly selected lung tissue slices, using the ImageJ image processing system (BI-2000 Medical Image Analysis System).

Statistical Analysis

SPSS version 19.0 software (IBM SPSS Statistics, IBM Corporation) was used for statistical analysis. Quantitative data were expressed as a percentage and measurement data as average ± SD. Comparisons between groups were performed by using single-factor analysis of variance between groups. Group means were compared by using independent sample Student t tests, with P < .05 for the difference being considered statistically significant.

Lung Gross Anatomy

Lungs of animals with hypobaric hypoxia-induced pulmonary edema treated with saline were swollen, with a dark pink surface (Figs 1A and 1B), hemorrhage and abscess formation, increased hardness of tissue, and frothy exudate (Figs 1C and 1D). There were no macroscopic findings in the lungs of plain control animals (Figs 1E and 1F). Macroscopic examination of the lungs of animals treated with solnatide, dexamethasone, and aminophylline revealed a smooth, pale pink lung surface, without hemorrhage or abscess formation and little frothing; lungs of the solnatide-treated animals exhibited less discoloration than those of the other treatment groups.

Figure 1
Figure Jump LinkFigure 1 A-F, Lung gross anatomy of the high-altitude control group and the low-altitude control group animals. A-B, High-altitude control group animals exhibit lung swelling and dark red discoloration. C-D, High-altitude control animals exhibit hemorrhage and abscess formation on lung surface with frothing. E-F, Low-altitude control group animals exhibit pale pink lung surface without bubble overflow.Grahic Jump Location
Light Microscopy

To assess the effect of solnatide on alveolar structure in animals with hypoxia-induced pulmonary edema, a low dose (100 μg), a medium dose (300 μg), or a high dose (500 μg) was used. Light microscopy examination revealed that low-altitude control animals had normal alveolar structure, with no red blood cells or pink proteinaceous material in the alveolar space (Fig 2A). Lung tissue from untreated animals with hypoxia-induced pulmonary edema had a compact texture, with signs of pulmonary vascular congestion, thickening of the alveolar septa, and the presence of red blood cells and pink proteinaceous material in the alveolar cavity (Fig 2B). Results of lung histology tests in the dexamethasone-treated animals (Fig 2C) revealed improved alveolar structure but still some degree of alveolar septal thickening. Alveolar structure in the solnatide-treated animals at all doses tested was normal, with slight alveolar septal thickening, but there were no signs of red blood cells or proteinaceous material in the alveolar cavity (Figs 2D, 2E, 2F).

Figure 2
Figure Jump LinkFigure 2 A-F, Lung histologic findings of lung tissue of rats after treatment with solnatide and other agents. A, Low-altitude control group animals. B, High-altitude control group animals. C, Dexamethasone treatment group animals. D, Solnatide low-dose treatment group animals. E, Solnatide medium-dose treatment group animals. F, Solnatide high-dose treatment group animals. Scale bar indicates 100 μm.Grahic Jump Location
Electron Microscopy

Electron microscopy studies revealed normal lung ultrastructure in low-altitude control animals, without fusion or fractures (Fig 3A). By contrast, profound changes to the lung ultrastructure were detected in the untreated high-altitude control animals, characterized by extensive disruption of the alveolar epithelial and capillary endothelial layers, and discontinuity of the blood-gas barrier. Disintegration of the bilayer membrane structure of capillary walls gave rise to a fuzzy or beaded appearance (Fig 3B). Membrane bilayer structure of the alveolar epithelium, septa, and blood vessels was mostly intact but fused in parts in HAPE animals undergoing treatment with dexamethasone (Fig 3C). Solnatide-treated animals, at all doses tested, exhibited an intact membrane structure of alveolar epithelium, septa, and capillary endothelium, with no evidence of fracture or disintegration (Figs 3D, 3E, 3F).

Figure 3
Figure Jump LinkFigure 3 A-F, Ultrastructure observation of lung tissue of rats after treatment with solnatide and other agents. A, Low-altitude control group animals. B, High-altitude control group animals. C, Dexamethasone treatment group animals. D, Solnatide low-dose treatment group animals. E, Solnatide medium-dose treatment group animals. F, Solnatide high-dose treatment group animals. Scale bars are provided with each picture.Grahic Jump Location
LWC and BALF Protein Content

As summarized in Table 1, we evaluated the effect of the three doses of solnatide on LWC in animals with hypobaric hypoxia- and exercise-induced pulmonary edema compared with dexamethasone. Both LWC and BALF protein levels were significantly lower in all solnatide treatment groups compared with the untreated HAPE animals (Table 2). LWC was lowest in the medium-dose solnatide group. BALF protein was lowest in both the low- and medium-dose solnatide groups (even lower than in the low-altitude control animals). BALF protein levels in rats treated with solnatide at all dose levels were significantly lower than in rats treated with dexamethasone.

Table Graphic Jump Location
Table 2 Lung Water Content and Alveolar Fluid Protein Content of Rats Treated With Solnatide and Dexamethasone
a P < .05 compared with high-altitude control animals treated with sodium chloride.
b P < .01 compared with high-altitude control animals treated with sodium chloride.
c P < .01 compared with high-altitude animals treated with dexamethasone.
d P < .01 compared with high-altitude animals treated with aminophylline.
e P < .05 compared with plain control animals not exposed to hypobaric or hypoxic conditions.
f P < .01 compared with plain control animals not exposed to hypobaric or hypoxic conditions.
g P < .05 compared with high-altitude animals treated with dexamethasone.
h P < .05 compared with high-altitude animals treated with aminophylline.

Data are presented as mean ± SD.

Detection of Tight Junction Protein Occludin

Immunohistochemical staining of lung tissue (Figs 4A to 4F) found that the expression of occludin protein was strongly positive in cells of the alveolar-capillary barrier in the low-altitude control animals (Fig 4A) and in all solnatide treatment groups (Figs 4D, 4E, 4F). In the untreated high-altitude animals (Fig 4B) and dexamethasone-treated rats (Fig 4C), the occludin expression was weakly positive.

Figure 4
Figure Jump LinkFigure 4 A-F, Immunohistochemical visualization of occludin expression in lung tissue of rats after treatment with solnatide and other agents. A, Low-altitude control group animals. B, High-altitude control group animals. C, Dexamethasone treatment group animals. D, Solnatide low-dose treatment group animals. E, Solnatide medium-dose treatment group animals. F, Solnatide high-dose treatment group animals. Magnification ×400.Grahic Jump Location

Quantitative measurement of occludin gray scale values revealed the highest occludin expression in low-altitude control animals compared with the other groups (Table 3), where the lowest occludin expression was observed in the untreated high-altitude control animals. Solnatide- and dexamethasone-treated animals exhibited significantly higher occludin expression than untreated high-altitude control rats. The level of occludin expression was particularly increased following treatment with medium and high doses of solnatide and significantly higher than in dexamethasone-treated animals.

Table Graphic Jump Location
Table 3 Occludin Expression in Alveolar Capillary Barriers of Rats Treated With Solnatide and Dexamethasone
a P < .01 compared with plain control animals not exposed to hypobaric or hypoxic conditions.
b P < .05 compared with high-altitude control animals treated with sodium chloride.
c P < .01 compared with high-altitude control animals treated with sodium chloride.
d P < .05 compared with high-altitude animals treated with dexamethasone.
e P < .05 compared with high-altitude animals treated with aminophylline.
f P < .05 compared with plain control animals not exposed to hypobaric or hypoxic conditions.
g P < .01 compared with high-altitude animals treated with dexamethasone.
h P < .01 compared with high-altitude animals treated with aminophylline.

Data are presented as mean ± SD.

Detection of Inflammatory Cytokines

As shown in Table 4, levels of TNF, IL-1β, IL-6, and IL-8 were significantly elevated in the blood of untreated high-altitude control animals compared with all other groups. Compared with the untreated high-altitude control animals, solnatide-treated animals had significantly lower levels of all cytokines/chemokines tested. Interestingly, TNF levels in the blood were significantly lower in animals treated with medium doses of solnatide compared with the dexamethasone-treated animals and the high-altitude control animals.

Table Graphic Jump Location
Table 4 Inflammatory Cytokines in the Blood of Rats Treated With Solnatide and Dexamethasone
a P < .01 compared with high-altitude control animals treated with sodium chloride.
b P < .05 compared with high-altitude animals treated with dexamethasone.
c P < .05 compared with high-altitude animals treated with aminophylline.
d P < .01 compared with plain control animals not exposed to hypobaric or hypoxic conditions.
e P < .01 compared with high-altitude animals treated with dexamethasone.
f P < .01 compared with high-altitude animals treated with aminophylline.
g P < .05 compared with plain control animals not exposed to hypobaric or hypoxic conditions.
h P < .05 compared with high-altitude control animals treated with sodium chloride.

Data are presented as mean ± SD. TNF = tumor necrosis factor.

Levels of TNF, IL-1β, IL-6, and IL-8 were significantly elevated in the BALF of the untreated high-altitude control animals (Table 5). Compared with the untreated high-altitude control animals, solnatide-treated animals had significantly lower levels of inflammatory cytokines in the BALF. Levels of TNF in the BALF of solnatide-treated animals were lower or nearly the same as those seen in low-altitude control animals and significantly lower than levels recorded for dexamethasone and untreated high-altitude control animals. Levels of IL-1β in solnatide- and dexamethasone-treated animals were significantly reduced compared with untreated high-altitude control rats. We also compared the therapeutic potency of solnatide vs aminophylline and inhibitors of mitogen-activated protein kinases and of the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome (e-Tables 1-5).

Table Graphic Jump Location
Table 5 Inflammatory Cytokines in the BALF of Rats Treated With Solnatide and Other Agents
a P < .05 compared with high-altitude control animals treated with sodium chloride.
b P < .05 compared with high-altitude animals treated with dexamethasone.
c P < .01 compared with high-altitude control animals treated with sodium chloride.
d P < .01 compared with high-altitude animals treated with dexamethasone.
e P < .01 compared with high-altitude animals treated with aminophylline.
f P < .05 compared with high-altitude animals treated with aminophylline.
g P < .05 compared with plain control animals not exposed to hypobaric or hypoxic conditions.
h P < .01 compared with plain control animals not exposed to hypobaric or hypoxic conditions.

Data are presented as mean ± SD. BALF = BAL fluid. See Table 4 legend for expansion of other abbreviation.

The dual mode of action of solnatide has been described in a battery of nonclinical studies. Upon binding of solnatide to ENaC in the airspace, the peptide increases both expression and open conformation of ENaC, thus improving sodium uptake and alveolar fluid clearance from the alveolar space across the alveolar cell membrane. Solnatide delivered by the pulmonary route was also shown to blunt ROS production upon lung transplantation and thereby improve lung function.,,,,,,,,

LWC is an indicator of overall lung edema severity, and BALF protein is an indicator of increased alveolar-capillary membrane permeability. The results of the present study showed that solnatide-treated animals experiencing acute hypobaric hypoxia and exercise had the lowest LWC of all treatment groups, significantly lower than the dexamethasone-treated animals. This finding indicates that solnatide is more efficacious for improving alveolar fluid clearance and edema resorption than the currently used agent in this model.

Solnatide was more potent in reducing the protein content in BALF than dexamethasone in this rat model. Solnatide was more effective at reducing protein leakage to the BALF and inhibiting the inflammatory cascade than current therapies for HAPE. Lower levels of IL-1β and IL-6 were found in both the BALF and blood of the solnatide-treated rats compared with the untreated animals. Significantly less TNF was detected in the BALF of solnatide-treated rats than in the dexamethasone-treated rats. Solnatide was also more potent than aminophylline in terms of LWC, BALF protein content, and inhibition of the inflammatory cascade.

Pulmonary application of solnatide resulted in increased expression of the tight junction protein occludin in alveolar walls. This finding translates into increased stability of the alveolar-capillary barrier and thus correlates with our observed reduction in the extent of protein leakage in solnatide-treated animals.

Inflammation is an important pathogenic feature of HAPE. Levels of alveolar macrophages, neutrophils and lymphocytes, albumin, and low-density lipoprotein cholesterol, as well as proinflammatory cytokines and chemokines (including IL-1β, IL-6, IL-8, and TNF), are increased in the BALF of patients with HAPE. A battery of inflammatory factors is apparently involved in the pathogenesis of HAPE. Hypoxia-induced rupture of cells in the pulmonary vascular endothelium, basement membrane exposure, and release of endogenous injury material and ROS could trigger the inflammatory response. Hypoxia stress conditions and block of electron transfer of the mitochondrial respiratory chain lead to increased ROS levels. Mitochondrial complex III is the main source of ROS under hypoxic conditions.,, IL-1β secretion resulting from ROS activation of the NLRP3 inflammasome is one of the major inflammatory mediators causing lung injury.,

Intratracheally applied solnatide also demonstrated potent antiinflammatory effects in a rat lung transplantation model by reducing neutrophil content and ROS generation in addition to improvement of lung function. In addition, the solnatide analogue peptide AP318 significantly mitigated the pulmonary inflammation markers IL-6, TNF, cyclooxygenase-2, and tenascin C in a porcine sepsis model after pulmonary application.

The NLRP3 inflammasome-activated cytokine IL-1β is found at significantly increased levels in HAPE, thus implicating the NLRP3 inflammasome in its pathogenesis. Rats given NLRP3 inhibitor had significantly reduced LWC, less severe edema and local pathologic changes of the lung, improved pulmonary vascular gas-blood barrier membrane structure, and reduced leakage of proteins and cytokine content in the BALF and blood. Solnatide-treated animals showed similar effects, suggesting solnatide can inhibit and interfere with the pathway of the NLRP3 inflammasome and with cytokine activation.

This study showed the effectiveness of solnatide in reducing LWC and BALF protein in rats stressed by exhaustive exercise and exposed to hypoxic hypobaric conditions. In our rat model used, the results provide convincing evidence that the antiedema and antiinflammatory properties of solnatide render it more effective than currently used drugs, such as dexamethasone and aminophylline. Furthermore, solnatide exerted an inhibitory effect on proinflammatory pathways by reducing the synthesis of cytokines and the inflammatory response. In addition, solnatide increased the expression of the tight junction protein occludin, thereby improving the stability of the alveolar capillary barriers, which in turn reduced leakage of protein into the alveolar fluid. Although our model is not representative for all HAPE cases, these results nevertheless indicate a promising therapeutic potential of solnatide for the treatment of human patients with pulmonary edema exposed to a high-altitude hypoxic environment.

Author contributions: B. F. is the guarantor of the paper, taking responsibility for the integrity of the work as a whole, from inception to published article. B.F. contributed to the experimental design; drafting the article or revising it critically for important intellectual content; and final approval of the version to be published. He had no role in the animal experiments, data collection, or data analysis. Q. Z. contributed to study conception and design; data acquisition, analysis, and interpretation; drafting the article or revising it critically for important intellectual content; and final approval of the version to be published. Q. Z. takes responsibility for the integrity of the data and the accuracy of the data analysis and serves as principal author. D. W., Y. L., and X. Y. contributed to experimental preparation; data acquisition, analysis, and interpretation; drafting the article or revising it critically for important intellectual content; and final approval of the version to be published. R. L. contributed to experimental design and data interpretation; drafting the article or revising it critically for important intellectual content; and final approval of the version to be published.

Financial/nonfinancial disclosures: The authors have reported to CHEST the following: B. F. is employee of APEPTICO, and APEPTICO has a pending patent in this scientific field. B. F. had no role in the animal experiments, data collection, or data analysis. None declared (Q. Z., D. W., Y. L., X. Y., R. L.).

Other contributions: The authors thank the personnel from the Key Laboratory of High Altitude Medicine of the Ministry of National Education, Biomedical Analysis Center of Southwest Hospital and Central Laboratory of Xinqiao Hospital, for their assistance in this study. They also thank Dr Susan Tzotzos (APEPTICO) for her support in scientific writing.

Additional information: The e-Tables can be found in the Supplemental Materials section of the online article.

Singh I. .Kapila C.C. .Khanna P.K. .Nanda R.B. .Rao B.D. . High altitude pulmonary oedema. Lancet. 1965;1:229-234 [PubMed]journal. [PubMed]
 
Mortimer H. .Patel S. .Peacock A.J. . The genetic basis of high-altitude pulmonary oedema. Pharmacol Ther. 2004;101:183-192 [PubMed]journal. [CrossRef] [PubMed]
 
West J.B. . American College of Physicians, American Physiological Society The physiologic basis of high-altitude diseases. Ann Intern Med. 2004;141:789-800 [PubMed]journal. [CrossRef] [PubMed]
 
Hackett P.H. .Rennie D. .Levine H.D. . The incidence, importance, and prophylaxis of acute mountain sickness. Lancet. 1976;2:1149-1155 [PubMed]journal. [PubMed]
 
Report on Mont Blanc Expedition April 1891. Neue Zürcher Zeitung. 1892;1:- [PubMed]journal
 
Arias-Stella J. .Kruger H. . Pathology of high altitude pulmonary edema. Arch Pathol. 1963;76:147-157 [PubMed]journal. [PubMed]
 
Nayak N.C. .Roy S. .Narayanan T.K. . Pathologic of altitude sickness. Am J Pathol. 1964;45:381-391 [PubMed]journal. [PubMed]
 
Bärtsch P. .Mairbäurl H. .Maggiorini M. .Swenson E.R. . Physiological aspects of high-altitude pulmonary edema. J Appl Physiol (1985). 2005;98:1101-1110 [PubMed]journal. [PubMed]
 
Zhou Q. . Standardization of methods for early diagnosis and on-site treatment of high-altitude pulmonary edema. Pulm Med. 2011;2011:190648- [PubMed]journal. [PubMed]
 
Wu T. . Mountain rescue: the highest earthquake in Yushu. High Alt Med Biol. 2011;12:93-95 [PubMed]journal. [CrossRef] [PubMed]
 
Basnyat B. .Subedi D. .Sleggs J. .et al Disoriented and ataxic pilgrims: an epidemiological study of acute mountain sickness and high-altitude cerebral edema at a sacred lake at 4300 m in the Nepal Himalayas. Wilderness Environ Med. 2000;11:89-93 [PubMed]journal. [CrossRef] [PubMed]
 
Ren Y. .Fu Z. .Shen W. .et al Incidence of high altitude illnesses among unacclimatized persons who acutely ascended to Tibet. High Alt Med Biol. 2010;11:39-42 [PubMed]journal. [CrossRef] [PubMed]
 
Lucas R. .Magez S. .De Leys R. .et al Mapping the lectin-like activity of tumor necrosis factor. Science. 1994;263:814-817 [PubMed]journal. [CrossRef] [PubMed]
 
Shabbir W. .Scherbaum-Hazemi P. .Tzotzos S. .et al Mechanism of action of novel lung edema therapeutic AP301 by activation of the epithelial sodium channel. Mol Pharmacol. 2013;84:899-910 [PubMed]journal. [CrossRef] [PubMed]
 
Czikora I. .Alli A. .Bao H.F. .et al A novel tumor necrosis factor-mediated mechanism of direct epithelial sodium channel activation. Am J Respir Crit Care Med. 2014;190:522-532 [PubMed]journal. [CrossRef] [PubMed]
 
Shabbir W. .Tzotzos S. .Bedak M. .et al Glycosylation-dependent activation of epithelial sodium channel by solnatide. Biochem Pharmacol. 2015;98:740-753 [PubMed]journal. [CrossRef] [PubMed]
 
Tzotzos S. .Fischer B. .Fischer H. .et al AP301, a synthetic peptide mimicking the lectin-like domain of TNF, enhances amiloride-sensitive Na(+) current in primary dog, pig and rat alveolar type II cells. Pulm Pharmacol Ther. 2013;26:356-363 [PubMed]journal. [CrossRef] [PubMed]
 
Elia N. .Tapponnier M. .Matthay M.A. .et al Functional identification of the alveolar edema reabsorption activity of murine tumor necrosis factor-alpha. Am J Respir Crit Care Med. 2003;168:1043-1050 [PubMed]journal. [CrossRef] [PubMed]
 
Braun C. .Hamacher J. .Morel D.R. .Wendel A. .Lucas R. . Dichotomal role of TNF in experimental pulmonary edema reabsorption. J Immunol. 2005;175:3402-3408 [PubMed]journal. [CrossRef] [PubMed]
 
Hartmann E.K. .Boehme S. .Duenges B. .et al An inhaled tumor necrosis factor-alpha-derived TIP peptide improves the pulmonary function in experimental lung injury. Acta Anaesthesiol Scand. 2013;57:334-341 [PubMed]journal. [CrossRef] [PubMed]
 
Hamacher J. .Stammberger U. .Roux J. .et al The lectin-like domain of tumor necrosis factor improves lung function after rat lung transplantation—potential role for a reduction in reactive oxygen species generation. Crit Care Med. 2010;38:871-878 [PubMed]journal. [CrossRef] [PubMed]
 
Schwameis R. .Eder S. .Pietschmann H. .et al A FIM study to assess safety and exposure of inhaled single doses of AP301-A specific ENaC channel activator for the treatment of acute lung injury. J Clin Pharmacol. 2014;54:341-350 [PubMed]journal. [CrossRef] [PubMed]
 
National Institutes of Health Clinical Center. Study in intensive care patients to investigate the clinical effect of repetitive orally inhaled doses of AP301 on alveolar liquid clearance in acute lung injury. NCT01627613. ClinicalTrials.gov. Bethesda, MD: National Institutes of Health (last updated: August 28, 2014).https://clinicaltrials.gov/ct2/show/NCT01627613?term=NCT01627613&rank=1.
 
National Institutes of Health Clinical Center. Study in intensive care patients regarding the effect of inhaled AP-301 after primary graft dysfunction after lung transplantation. NCT02095626. ClinicalTrials.gov. Bethesda, MD: National Institutes of Health (last updated: July 23, 2015).https://clinicaltrials.gov/ct2/show/NCT02095626?term=NCT02095626&rank=1.
 
Vivona M.L. .Matthay M. .Chabaud M.B. .Friedlander G. .Clerici C. . Hypoxia reduces alveolar epithelial sodium and fluid transport in rats: reversal by beta-adrenergic agonist treatment. Am J Respir Cell MolBiol. 2001;25:554-561 [PubMed]journal. [CrossRef]
 
Urner M. .Herrmann I.K. .Booy C. .Roth-Z’ Graggen B. .Maggiorini M. .Beck-Schimmer B. . Effect of hypoxia and dexamethasone on inflammation and ion transporter function in pulmonary cells. Clin ExpImmunol. 2012;169:119-128 [PubMed]journal
 
Gille T. .Randrianarison-Pellan N. .Goolaerts A. .et al Hypoxia-induced inhibition of epithelial Na(+) channels in the lung. Role of Nedd4-2 and the ubiquitin-proteasome pathway. Am J Respir Cell MolBiol. 2014;50:526-537 [PubMed]journal. [CrossRef]
 
Abstracts from The Aerosol Society Drug Delivery to the Lungs 26 Edinburgh International Conference Centre Edinburgh, Scotland, UK December 9-11, 2015. J Aerosol Med Pulm Drug Deliv. 2016;29:A1-A25 [PubMed]journal. [CrossRef] [PubMed]
 
Bai C. .She J. .Goolaerts A. .et al Stress failure plays a major role in the development of high-altitude pulmonary oedema in rats. Eur Respir J. 2010;35:584-591 [PubMed]journal. [CrossRef] [PubMed]
 
Elliott K.A. .Jasper H. . Measurement of experimentally induced brain swelling and shrinkage. Am J Physiol. 1949;157:122-129 [PubMed]journal. [PubMed]
 
West J.B. .Colice G.L. .Lee Y.J. .et al Pathogenesis of high-altitude pulmonary oedema: direct evidence of stress failure of pulmonary capillaries. Eur Respir J. 1995;8:523-529 [PubMed]journal. [PubMed]
 
Mooradian A.D. .Haas M.J. .Chehade J.M. . Age-related changes in rat cerebral occludin and zonula occludens-1 (ZO-1). Mech Ageing Dev. 2003;124:143-146 [PubMed]journal. [CrossRef] [PubMed]
 
Michel R.P. .Hakim T.S. .Smith T.T. .Poulsen R.S. . Quantitative morphology of permeability lung edema in dogs induced by alpha-naphthylthiourea. Lab Investig J Tech Methods Pathol. 1983;49:412-419 [PubMed]journal
 
Briot R. .Bayat S. .Anglade D. .Martiel J.L. .Grimbert F. . Monitoring the capillary-alveolar leakage in an A.R.D.S. model using broncho-alveolar lavage. Microcirculation 1994. 2008;15:237-249 [PubMed]journal
 
Kubo K. .Hanaoka M. .Hayano T. .et al Inflammatory cytokines in BAL fluid and pulmonary hemodynamics in high-altitude pulmonary edema. Respir Physiol. 1998;111:301-310 [PubMed]journal. [CrossRef] [PubMed]
 
Zhou L. .Aon M.A. .Almas T. .Cortassa S. .Winslow R.L. .O’Rourke B. . A reaction-diffusion model of ROS-induced ROS release in a mitochondrial network. PLoS Comput Biol. 2010;6:e1000657- [PubMed]journal. [CrossRef] [PubMed]
 
Zhou R. .Yazdi A.S. .Menu P. .Tschopp J. . A role for mitochondria in NLRP3 inflammasome activation. Nature. 2011;469:221-225 [PubMed]journal. [CrossRef] [PubMed]
 
Korde A.S. .Yadav V.R. .Zheng Y.M. .Wang Y.X. . Primary role of mitochondrial Rieske iron-sulfur protein in hypoxic ROS production in pulmonary artery myocytes. Free Radic Biol Med. 2011;50:945-952 [PubMed]journal. [CrossRef] [PubMed]
 
Han S. .Cai W. .Yang X. .et al ROS-mediated NLRP3 inflammasome activity is essential for burn-induced acute lung injury. Mediators Inflamm. 2015;2015:720457- [PubMed]journal. [PubMed]
 
Zhou G. .Dada L.A. .Sznajder J.I. . Regulation of alveolar epithelial function by hypoxia. Eur Respir J. 2008;31:1107-1113 [PubMed]journal. [CrossRef] [PubMed]
 
Hartmann E.K. .Ziebart A. .Thomas R. .et al Inhalation therapy with the synthetic TIP-like peptide AP318 attenuates pulmonary inflammation in a porcine sepsis model. BMC Pulm Med. 2015;15:7- [PubMed]journal. [CrossRef] [PubMed]
 

Figures

Figure Jump LinkFigure 1 A-F, Lung gross anatomy of the high-altitude control group and the low-altitude control group animals. A-B, High-altitude control group animals exhibit lung swelling and dark red discoloration. C-D, High-altitude control animals exhibit hemorrhage and abscess formation on lung surface with frothing. E-F, Low-altitude control group animals exhibit pale pink lung surface without bubble overflow.Grahic Jump Location
Figure Jump LinkFigure 2 A-F, Lung histologic findings of lung tissue of rats after treatment with solnatide and other agents. A, Low-altitude control group animals. B, High-altitude control group animals. C, Dexamethasone treatment group animals. D, Solnatide low-dose treatment group animals. E, Solnatide medium-dose treatment group animals. F, Solnatide high-dose treatment group animals. Scale bar indicates 100 μm.Grahic Jump Location
Figure Jump LinkFigure 3 A-F, Ultrastructure observation of lung tissue of rats after treatment with solnatide and other agents. A, Low-altitude control group animals. B, High-altitude control group animals. C, Dexamethasone treatment group animals. D, Solnatide low-dose treatment group animals. E, Solnatide medium-dose treatment group animals. F, Solnatide high-dose treatment group animals. Scale bars are provided with each picture.Grahic Jump Location
Figure Jump LinkFigure 4 A-F, Immunohistochemical visualization of occludin expression in lung tissue of rats after treatment with solnatide and other agents. A, Low-altitude control group animals. B, High-altitude control group animals. C, Dexamethasone treatment group animals. D, Solnatide low-dose treatment group animals. E, Solnatide medium-dose treatment group animals. F, Solnatide high-dose treatment group animals. Magnification ×400.Grahic Jump Location

Tables

Table Graphic Jump Location
Table 1 Rodent Model of HAPE: Experimental Groups and Treatment Regimens
a Animals of all experimental groups were subject to exhaustive exercise.
b Otsuka Pharmaceutical Co, Ltd.
c Henan Hong Pharmaceutical Co Ltd.

APH = high-altitude animals treated with solnatide high concentration; APM = high-altitude animals treated with solnatide medium concentration; APS = high-altitude animals treated with solnatide low concentration; DMT = high-altitude animals treated with dexamethasone; HAPE = high-altitude pulmonary edema; PCT = plain control animals not exposed to hypobaric or hypoxic conditions; SCT = high-altitude control animals treated with sodium chloride.

Table Graphic Jump Location
Table 2 Lung Water Content and Alveolar Fluid Protein Content of Rats Treated With Solnatide and Dexamethasone
a P < .05 compared with high-altitude control animals treated with sodium chloride.
b P < .01 compared with high-altitude control animals treated with sodium chloride.
c P < .01 compared with high-altitude animals treated with dexamethasone.
d P < .01 compared with high-altitude animals treated with aminophylline.
e P < .05 compared with plain control animals not exposed to hypobaric or hypoxic conditions.
f P < .01 compared with plain control animals not exposed to hypobaric or hypoxic conditions.
g P < .05 compared with high-altitude animals treated with dexamethasone.
h P < .05 compared with high-altitude animals treated with aminophylline.

Data are presented as mean ± SD.

Table Graphic Jump Location
Table 3 Occludin Expression in Alveolar Capillary Barriers of Rats Treated With Solnatide and Dexamethasone
a P < .01 compared with plain control animals not exposed to hypobaric or hypoxic conditions.
b P < .05 compared with high-altitude control animals treated with sodium chloride.
c P < .01 compared with high-altitude control animals treated with sodium chloride.
d P < .05 compared with high-altitude animals treated with dexamethasone.
e P < .05 compared with high-altitude animals treated with aminophylline.
f P < .05 compared with plain control animals not exposed to hypobaric or hypoxic conditions.
g P < .01 compared with high-altitude animals treated with dexamethasone.
h P < .01 compared with high-altitude animals treated with aminophylline.

Data are presented as mean ± SD.

Table Graphic Jump Location
Table 4 Inflammatory Cytokines in the Blood of Rats Treated With Solnatide and Dexamethasone
a P < .01 compared with high-altitude control animals treated with sodium chloride.
b P < .05 compared with high-altitude animals treated with dexamethasone.
c P < .05 compared with high-altitude animals treated with aminophylline.
d P < .01 compared with plain control animals not exposed to hypobaric or hypoxic conditions.
e P < .01 compared with high-altitude animals treated with dexamethasone.
f P < .01 compared with high-altitude animals treated with aminophylline.
g P < .05 compared with plain control animals not exposed to hypobaric or hypoxic conditions.
h P < .05 compared with high-altitude control animals treated with sodium chloride.

Data are presented as mean ± SD. TNF = tumor necrosis factor.

Table Graphic Jump Location
Table 5 Inflammatory Cytokines in the BALF of Rats Treated With Solnatide and Other Agents
a P < .05 compared with high-altitude control animals treated with sodium chloride.
b P < .05 compared with high-altitude animals treated with dexamethasone.
c P < .01 compared with high-altitude control animals treated with sodium chloride.
d P < .01 compared with high-altitude animals treated with dexamethasone.
e P < .01 compared with high-altitude animals treated with aminophylline.
f P < .05 compared with high-altitude animals treated with aminophylline.
g P < .05 compared with plain control animals not exposed to hypobaric or hypoxic conditions.
h P < .01 compared with plain control animals not exposed to hypobaric or hypoxic conditions.

Data are presented as mean ± SD. BALF = BAL fluid. See Table 4 legend for expansion of other abbreviation.

References

Singh I. .Kapila C.C. .Khanna P.K. .Nanda R.B. .Rao B.D. . High altitude pulmonary oedema. Lancet. 1965;1:229-234 [PubMed]journal. [PubMed]
 
Mortimer H. .Patel S. .Peacock A.J. . The genetic basis of high-altitude pulmonary oedema. Pharmacol Ther. 2004;101:183-192 [PubMed]journal. [CrossRef] [PubMed]
 
West J.B. . American College of Physicians, American Physiological Society The physiologic basis of high-altitude diseases. Ann Intern Med. 2004;141:789-800 [PubMed]journal. [CrossRef] [PubMed]
 
Hackett P.H. .Rennie D. .Levine H.D. . The incidence, importance, and prophylaxis of acute mountain sickness. Lancet. 1976;2:1149-1155 [PubMed]journal. [PubMed]
 
Report on Mont Blanc Expedition April 1891. Neue Zürcher Zeitung. 1892;1:- [PubMed]journal
 
Arias-Stella J. .Kruger H. . Pathology of high altitude pulmonary edema. Arch Pathol. 1963;76:147-157 [PubMed]journal. [PubMed]
 
Nayak N.C. .Roy S. .Narayanan T.K. . Pathologic of altitude sickness. Am J Pathol. 1964;45:381-391 [PubMed]journal. [PubMed]
 
Bärtsch P. .Mairbäurl H. .Maggiorini M. .Swenson E.R. . Physiological aspects of high-altitude pulmonary edema. J Appl Physiol (1985). 2005;98:1101-1110 [PubMed]journal. [PubMed]
 
Zhou Q. . Standardization of methods for early diagnosis and on-site treatment of high-altitude pulmonary edema. Pulm Med. 2011;2011:190648- [PubMed]journal. [PubMed]
 
Wu T. . Mountain rescue: the highest earthquake in Yushu. High Alt Med Biol. 2011;12:93-95 [PubMed]journal. [CrossRef] [PubMed]
 
Basnyat B. .Subedi D. .Sleggs J. .et al Disoriented and ataxic pilgrims: an epidemiological study of acute mountain sickness and high-altitude cerebral edema at a sacred lake at 4300 m in the Nepal Himalayas. Wilderness Environ Med. 2000;11:89-93 [PubMed]journal. [CrossRef] [PubMed]
 
Ren Y. .Fu Z. .Shen W. .et al Incidence of high altitude illnesses among unacclimatized persons who acutely ascended to Tibet. High Alt Med Biol. 2010;11:39-42 [PubMed]journal. [CrossRef] [PubMed]
 
Lucas R. .Magez S. .De Leys R. .et al Mapping the lectin-like activity of tumor necrosis factor. Science. 1994;263:814-817 [PubMed]journal. [CrossRef] [PubMed]
 
Shabbir W. .Scherbaum-Hazemi P. .Tzotzos S. .et al Mechanism of action of novel lung edema therapeutic AP301 by activation of the epithelial sodium channel. Mol Pharmacol. 2013;84:899-910 [PubMed]journal. [CrossRef] [PubMed]
 
Czikora I. .Alli A. .Bao H.F. .et al A novel tumor necrosis factor-mediated mechanism of direct epithelial sodium channel activation. Am J Respir Crit Care Med. 2014;190:522-532 [PubMed]journal. [CrossRef] [PubMed]
 
Shabbir W. .Tzotzos S. .Bedak M. .et al Glycosylation-dependent activation of epithelial sodium channel by solnatide. Biochem Pharmacol. 2015;98:740-753 [PubMed]journal. [CrossRef] [PubMed]
 
Tzotzos S. .Fischer B. .Fischer H. .et al AP301, a synthetic peptide mimicking the lectin-like domain of TNF, enhances amiloride-sensitive Na(+) current in primary dog, pig and rat alveolar type II cells. Pulm Pharmacol Ther. 2013;26:356-363 [PubMed]journal. [CrossRef] [PubMed]
 
Elia N. .Tapponnier M. .Matthay M.A. .et al Functional identification of the alveolar edema reabsorption activity of murine tumor necrosis factor-alpha. Am J Respir Crit Care Med. 2003;168:1043-1050 [PubMed]journal. [CrossRef] [PubMed]
 
Braun C. .Hamacher J. .Morel D.R. .Wendel A. .Lucas R. . Dichotomal role of TNF in experimental pulmonary edema reabsorption. J Immunol. 2005;175:3402-3408 [PubMed]journal. [CrossRef] [PubMed]
 
Hartmann E.K. .Boehme S. .Duenges B. .et al An inhaled tumor necrosis factor-alpha-derived TIP peptide improves the pulmonary function in experimental lung injury. Acta Anaesthesiol Scand. 2013;57:334-341 [PubMed]journal. [CrossRef] [PubMed]
 
Hamacher J. .Stammberger U. .Roux J. .et al The lectin-like domain of tumor necrosis factor improves lung function after rat lung transplantation—potential role for a reduction in reactive oxygen species generation. Crit Care Med. 2010;38:871-878 [PubMed]journal. [CrossRef] [PubMed]
 
Schwameis R. .Eder S. .Pietschmann H. .et al A FIM study to assess safety and exposure of inhaled single doses of AP301-A specific ENaC channel activator for the treatment of acute lung injury. J Clin Pharmacol. 2014;54:341-350 [PubMed]journal. [CrossRef] [PubMed]
 
National Institutes of Health Clinical Center. Study in intensive care patients to investigate the clinical effect of repetitive orally inhaled doses of AP301 on alveolar liquid clearance in acute lung injury. NCT01627613. ClinicalTrials.gov. Bethesda, MD: National Institutes of Health (last updated: August 28, 2014).https://clinicaltrials.gov/ct2/show/NCT01627613?term=NCT01627613&rank=1.
 
National Institutes of Health Clinical Center. Study in intensive care patients regarding the effect of inhaled AP-301 after primary graft dysfunction after lung transplantation. NCT02095626. ClinicalTrials.gov. Bethesda, MD: National Institutes of Health (last updated: July 23, 2015).https://clinicaltrials.gov/ct2/show/NCT02095626?term=NCT02095626&rank=1.
 
Vivona M.L. .Matthay M. .Chabaud M.B. .Friedlander G. .Clerici C. . Hypoxia reduces alveolar epithelial sodium and fluid transport in rats: reversal by beta-adrenergic agonist treatment. Am J Respir Cell MolBiol. 2001;25:554-561 [PubMed]journal. [CrossRef]
 
Urner M. .Herrmann I.K. .Booy C. .Roth-Z’ Graggen B. .Maggiorini M. .Beck-Schimmer B. . Effect of hypoxia and dexamethasone on inflammation and ion transporter function in pulmonary cells. Clin ExpImmunol. 2012;169:119-128 [PubMed]journal
 
Gille T. .Randrianarison-Pellan N. .Goolaerts A. .et al Hypoxia-induced inhibition of epithelial Na(+) channels in the lung. Role of Nedd4-2 and the ubiquitin-proteasome pathway. Am J Respir Cell MolBiol. 2014;50:526-537 [PubMed]journal. [CrossRef]
 
Abstracts from The Aerosol Society Drug Delivery to the Lungs 26 Edinburgh International Conference Centre Edinburgh, Scotland, UK December 9-11, 2015. J Aerosol Med Pulm Drug Deliv. 2016;29:A1-A25 [PubMed]journal. [CrossRef] [PubMed]
 
Bai C. .She J. .Goolaerts A. .et al Stress failure plays a major role in the development of high-altitude pulmonary oedema in rats. Eur Respir J. 2010;35:584-591 [PubMed]journal. [CrossRef] [PubMed]
 
Elliott K.A. .Jasper H. . Measurement of experimentally induced brain swelling and shrinkage. Am J Physiol. 1949;157:122-129 [PubMed]journal. [PubMed]
 
West J.B. .Colice G.L. .Lee Y.J. .et al Pathogenesis of high-altitude pulmonary oedema: direct evidence of stress failure of pulmonary capillaries. Eur Respir J. 1995;8:523-529 [PubMed]journal. [PubMed]
 
Mooradian A.D. .Haas M.J. .Chehade J.M. . Age-related changes in rat cerebral occludin and zonula occludens-1 (ZO-1). Mech Ageing Dev. 2003;124:143-146 [PubMed]journal. [CrossRef] [PubMed]
 
Michel R.P. .Hakim T.S. .Smith T.T. .Poulsen R.S. . Quantitative morphology of permeability lung edema in dogs induced by alpha-naphthylthiourea. Lab Investig J Tech Methods Pathol. 1983;49:412-419 [PubMed]journal
 
Briot R. .Bayat S. .Anglade D. .Martiel J.L. .Grimbert F. . Monitoring the capillary-alveolar leakage in an A.R.D.S. model using broncho-alveolar lavage. Microcirculation 1994. 2008;15:237-249 [PubMed]journal
 
Kubo K. .Hanaoka M. .Hayano T. .et al Inflammatory cytokines in BAL fluid and pulmonary hemodynamics in high-altitude pulmonary edema. Respir Physiol. 1998;111:301-310 [PubMed]journal. [CrossRef] [PubMed]
 
Zhou L. .Aon M.A. .Almas T. .Cortassa S. .Winslow R.L. .O’Rourke B. . A reaction-diffusion model of ROS-induced ROS release in a mitochondrial network. PLoS Comput Biol. 2010;6:e1000657- [PubMed]journal. [CrossRef] [PubMed]
 
Zhou R. .Yazdi A.S. .Menu P. .Tschopp J. . A role for mitochondria in NLRP3 inflammasome activation. Nature. 2011;469:221-225 [PubMed]journal. [CrossRef] [PubMed]
 
Korde A.S. .Yadav V.R. .Zheng Y.M. .Wang Y.X. . Primary role of mitochondrial Rieske iron-sulfur protein in hypoxic ROS production in pulmonary artery myocytes. Free Radic Biol Med. 2011;50:945-952 [PubMed]journal. [CrossRef] [PubMed]
 
Han S. .Cai W. .Yang X. .et al ROS-mediated NLRP3 inflammasome activity is essential for burn-induced acute lung injury. Mediators Inflamm. 2015;2015:720457- [PubMed]journal. [PubMed]
 
Zhou G. .Dada L.A. .Sznajder J.I. . Regulation of alveolar epithelial function by hypoxia. Eur Respir J. 2008;31:1107-1113 [PubMed]journal. [CrossRef] [PubMed]
 
Hartmann E.K. .Ziebart A. .Thomas R. .et al Inhalation therapy with the synthetic TIP-like peptide AP318 attenuates pulmonary inflammation in a porcine sepsis model. BMC Pulm Med. 2015;15:7- [PubMed]journal. [CrossRef] [PubMed]
 
NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).
Supporting Data

e-Tables 1-5

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

CHEST Journal Articles
  • CHEST Journal
    Print ISSN: 0012-3692
    Online ISSN: 1931-3543