Cyclooxygenase-2 Deficiency Attenuates Lipopolysaccharide-induced Inflammation, Apoptosis and Acute Lung Injury in Adult Mice

Author(s):  
Leif D. Nelin ◽  
Yi Jin ◽  
Bernadette Chen ◽  
Yusen Liu ◽  
Lynette K. Rogers ◽  
...  

Many lung diseases are caused by an excessive inflammatory response, and inflammatory lung diseases are often modeled using lipopolysaccharide (LPS) in mice. Cyclooxygenase-2 (COX-2) encoded by the Ptgs2 gene is induced in response to inflammatory stimuli including lipopolysaccharide (LPS). The objective of this study was to test the hypothesis that mice deficient in COX-2 (Ptgs2-/-) will be protected from LPS-induced lung injury. Wild type (WT, CD1 mice) and Ptgs2-/- mice (on a CD1 background) were treated with LPS or vehicle for 24 hours. LPS-treatment resulted in histological evidence of lung injury, which was attenuated in the Ptgs2-/- mice. LPS-treatment increased the mRNA levels for tumor necrosis factor (TNF)-α, interleukin (IL)-10, and monocyte chemoattractant protein (MCP)-1 in the lungs of WT mice, and the LPS-induced increases in these levels were attenuated in the Ptgs2-/- mice. The protein levels of active caspase-3 and caspase-9 were lower in the LPS-treated lungs of Ptgs2-/- mice than in LPS-treated WT mice, as were the number of TUNEL positive cells in lung sections. LPS exposure resulted in greater lung wet-to-dry weight ratio (W/D) in WT mice, suggestive of pulmonary edema; while in LPS-treated Ptgs2-/- mice the W/D was not different from controls and less than in LPS-treated WT mice. These results demonstrate that COX-2 is involved in the inflammatory response to LPS, and suggest that COX-2 not only acts as a downstream participant in the inflammatory response, but also acts as a regulator of the inflammatory response likely through a feed-forward mechanism following LPS stimulation.

2019 ◽  
Vol 39 (6) ◽  
Author(s):  
Shuiqiao Fu ◽  
Weina Lu ◽  
Wenqiao Yu ◽  
Jun Hu

Abstract Background: To study the protective effect of Cordyceps sinensis extract (Dong Chong Xia Cao in Chinese [DCXC]) on experimental acute lung injury (ALI) mice. Methods and results: ALI model was induced by intratracheal-instilled lipopolysaccharide (LPS, 2.4 mg/kg) in BALB/c male mice. The mice were administrated DCXC (ig, 10, 30, 60 mg/kg) in 4 and 8 h after receiving LPS. Histopathological section, wet/dry lung weight ratio and myeloperoxidase activity were detected. Bronchoalveolar lavage fluid (BALF) was collected for cell count, the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and nitric oxide (NO) in BALF was detected by ELISA, the protein and mRNA expression of nuclear factor-κB p65 (NF-κB p65), inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in lung tissue was detected by Western blot and RT-PCR. The result showed that DCXC could reduce the degree of histopathological injury, wet/dry weight ratio (W/D ratio) and myeloperoxidase activity (P<0.05) with a dose-dependent manner. The increased number of total cells, neutrophils and macrophages in BALF were significantly inhibited by DCXC treatment (P<0.05). The increased levels of TNF-α, IL-1β, IL-6 and NO in BALF after LPS administration was significantly reduced by DCXC (P<0.05). In addition, the increased protein and mRNA levels of iNOS, COX-2 and NF-κB p65 DNA binding ability in LPS group were dose-dependently reduced by DCXC treatment (P<0.05). Conclusion: DCXC could play an anti-inflammatory and antioxidant effect on LPS-induced ALI through inhibiting NF-κB p65 phosphorylation, and the expression of COX-2 and iNOS in lung. The result showed that DCXC has a potential protective effect on the ALI.


2006 ◽  
Vol 104 (1) ◽  
pp. 133-141 ◽  
Author(s):  
Torsten Schreiber ◽  
Lars Hueter ◽  
Konrad Schwarzkopf ◽  
Sylvia Hohlstein ◽  
Barbara Schmidt ◽  
...  

Background Endotoxin, when delivered shortly before or during mechanical ventilation, increases susceptibility to ventilation-associated lung injury. However, it is unclear whether increased susceptibility to ventilator-associated lung injury is still present after clinical recovery from a transient endotoxin challenge. Methods Anesthetized rats were submitted to a 4-h period of mechanical ventilation with low (8 ml/kg) or high (24, 27, or 30 ml/kg) tidal volumes (VTs) 24 h after transient illness had been provoked by a single nonlethal intravenous injection of Escherichia coli endotoxin. Control animals were injected with phosphate-buffered saline and underwent the same protocol. Results At 24 h, endotoxin-treated nonventilated animals showed no symptoms of clinical illness, and oxygenation was comparable with that of controls, but lung neutrophil counts were increased. Compared with controls, mechanical ventilation with high VT induced a stronger pulmonary inflammatory response and more severe lung injury in endotoxin-treated animals, as indicated by impaired oxygenation, increased lung wet-to-dry weight ratio, and increased levels of protein, neutrophils, and cytokines in lung lavage fluid. In addition, the highest VT resulted in increased mortality in endotoxin-treated animals. Low VT after endotoxin treatment did not cause functional pulmonary impairment but induced an inflammatory response. Conclusions In this animal model, a 24-h delay after a single systemic injection of endotoxin resulted in clinical recovery and preserved pulmonary function but did not prevent increased susceptibility to ventilator-associated lung injury provoked by high VT. Residual pulmonary inflammation and neutrophilic infiltration at initiation of mechanical ventilation probably contribute to these findings.


2021 ◽  
Vol 49 (5) ◽  
pp. 117-124
Author(s):  
Wenmei Liang ◽  
Li Guo ◽  
Tonghua Liu ◽  
Song Qin

Background: Sepsis is a systemic inflammatory response syndrome and leads to patient’s death. Objective: To investigate the effect of myocyte enhancer factor 2 (MEF2C) on acute lung injury (ALI) with sepsis and its possible mechanism.Material and Methods: The cecal ligation and puncture (CLP)-induced sepsis rat model was established. The lung injury was determined by lung wet–dry weight ratio, the concentration of inflammatory cytokines, including tumor necrosis factor-α (TNF-α), Interlukin (IL)-6, IL-1β, and IL-10, were measured by the enzyme-linked-immunosorbent serologic assay kit. The cell apoptosis was detected by TUNEL staining assay.Results: Interestingly, MEF2C was down-regulated in this model. Moreover, adeno-associated virus (AAV)-MEF2C treatment markedly suppressed TNF-α, IL-1β, and IL-6 concentrations but promoted IL-10 concentration in serum in CLP-challenged rats. Besides, overexpression of MEF2C alleviates CLP-induced lung injury. Interestingly, AAV-MEF2C treatment was confirmed to suppress apoptosis in CLP-induced sepsis rats as well as promote aquaporin APQ1 expres-sion. Mechanistically, the rescue experiments indicated that MEF2C alleviated CLP-induced lung inflammatory response and apoptosis via up-regulating AQP1.Conclusion: In summary, overexpression of MEF2C suppressed CLP-induced lung inflamma-tory response and apoptosis via up-regulating AQP1, providing a novel therapeutic target for sepsis-induced ALI.


1986 ◽  
Vol 71 (2) ◽  
pp. 205-209 ◽  
Author(s):  
Stanley Braude ◽  
David Royston

1. The effect in the rat of salbutamol infusion (1 μg min−1 kg−1) on acid-induced lung injury has been determined. Severity of lung injury was assessed by two techniques: the pulmonary clearance of 99mTc-diethylenetriaminepenta-acetate (99mTc-DTPA) and the lung wet/dry weight ratio, giving indices of alveolar epithelial permeability and transendothelial water filtration respectively. 2. Mean half-time of clearance of 99mTc-DTPA was increased significantly in rats who had intratracheal acid-induced injury and control (saline) intravenous infusion (19.4 ± 2.6 min) compared with non-acid-treated rats (98.1 ± 7.2) (P < 0.0001). However, those animals who had intratracheal acid injury and subsequent salbutamol intravenous infusion had significantly faster clearance (11.5 ± 1.9) than the acid and control infusion group (P < 0.05). 3. Gravimetric lung water in the acid-only rats (expressed as wet/dry weight ratio) was increased significantly (6.4 ± 0.3) compared with the non-acid-treated controls (5.4 ± 0.2) (P < 0.01). Acid-treated rats who had salbutamol infused had dramatically increased lung water (10.0 ± 0.6) (P < 0.001 vs acid and control infusion). 4. Intravenous salbutamol infusion itself produced no significant difference in the results for both techniques, compared with the non-acid-treated time-course controls. 5. Infused salbutamol accentuates acid-induced lung injury in the rat. Possible factors responsible for these findings include β2-adrenergic agonist mediated inhibition of hypoxic pulmonary vasoconstriction (HPV) and a predominant β1-adrenergic agonist inotropic effect of salbutamol with resultant rise in pulmonary artery pressure.


2021 ◽  
Vol 22 (11) ◽  
pp. 5533
Author(s):  
Alessio Filippo Peritore ◽  
Ramona D’Amico ◽  
Rosalba Siracusa ◽  
Marika Cordaro ◽  
Roberta Fusco ◽  
...  

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are common and devastating clinical disorders with high mortality and no specific therapy. Lipopolysaccharide (LPS) is usually used intratracheally to induce ALI in mice. The aim of this study was to examine the effects of an ultramicronized preparation of palmitoylethanolamide (um-PEA) in mice subjected to LPS-induced ALI. Histopathological analysis reveals that um-PEA reduced alteration in lung after LPS intratracheal administration. Besides, um-PEA decreased wet/dry weight ratio and myeloperoxidase, a marker of neutrophils infiltration, macrophages and total immune cells number and mast cells degranulation in lung. Moreover, um-PEA could also decrease cytokines release of interleukin (IL)-6, interleukin (IL)-1β, tumor necrosis factor (TNF)-α and interleukin (IL)-18. Furthermore, um-PEA significantly inhibited the phosphorylation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation in ALI, and at the same time decreased extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38/MAPK) expression, that was increased after LPS administration. Our study suggested that um-PEA contrasted LPS-induced ALI, exerting its potential role as an adjuvant anti-inflammatory therapeutic for treating lung injury, maybe also by p38/NF-κB pathway.


1999 ◽  
Vol 112 (18) ◽  
pp. 3147-3155
Author(s):  
N.A. Callejas ◽  
M. Casado ◽  
L. Bosca ◽  
P. Martin-Sanz

Recently isolated trophoblasts express nitric oxide synthase 2 (NOS-2) and cyclooxygenase 2 (COX-2), decreasing the levels of the corresponding mRNAs when the cells were maintained in culture. The sustained expression of COX-2 and NOS-2 in trophoblasts was dependent on the activation of nuclear factor kappaB (NF-kappaB) since proteasome inhibitors and antioxidants that abrogated NF-kappaB activity suppressed the induction of both genes. The time-dependent fall of the mRNA levels of NOS-2 and COX-2 paralleled the inhibition of NF-kappaB, determined by electrophoretic mobility shift assays, and the increase of the IkappaBalpha and IkappaBbeta inhibitory proteins. Isolated trophoblasts synthesized reactive oxygen intermediates (ROI), a process impaired after culturing the cells, and that might be involved in the NF-kappaB activation process. Moreover, treatment of recently isolated cells with ROI scavengers suppressed the expression of COX-2 and NOS-2. Challenge of trophoblasts with interleukin-1beta up-regulated the expression of both proteins, an effect that was potentiated by lipopolysaccharide. These results indicate that the physiological expression of NOS-2 and COX-2 in trophoblasts involves a sustained activation of NF-kappaB which inhibition abrogates the inducibility of both genes.


2006 ◽  
Vol 291 (4) ◽  
pp. L580-L587 ◽  
Author(s):  
Je Hyeong Kim ◽  
Min Hyun Suk ◽  
Dae Wui Yoon ◽  
Seung Heon Lee ◽  
Gyu Young Hur ◽  
...  

Neutrophils are considered to play a central role in ventilator-induced lung injury (VILI). However, the pulmonary consequences of neutrophil accumulation have not been fully elucidated. Matrix metalloproteinase-9 (MMP-9) had been postulated to participate in neutrophil transmigration. The purpose of this study was to investigate the role of MMP-9 in the neutrophilic inflammation of VILI. Male Sprague-Dawley rats were divided into three groups: 1) low tidal volume (LVT), 7 ml/kg of tidal volume (VT); 2) high tidal volume (HVT), 30 ml/kg of VT; and 3) HVT with MMP inhibitor (HVT+MMPI). As a MMPI, CMT-3 was administered daily from 3 days before mechanical ventilation. Degree of VILI was assessed by wet-to-dry weight ratio and acute lung injury (ALI) scores. Neutrophilic inflammation was determined from the neutrophil count in the lung tissue and myeloperoxidase (MPO) activity in the bronchoalveolar lavage fluid (BALF). MMP-9 expression and activity were examined by immunohistochemical staining and gelatinase zymography, respectively. The wet-to-dry weight ratio, ALI score, neutrophil infiltration, and MPO activity were increased significantly in the HVT group. However, in the HVT+MMPI group, pretreatment with MMPI decreased significantly the degree of VILI, as well as neutrophil infiltration and MPO activity. These changes correlated significantly with MMP-9 immunoreactivity and MMP-9 activity. Most outcomes were significantly worse in the HVT+MMPI group compared with the LVT group. In conclusion, VILI mediated by neutrophilic inflammation is closely related to MMP-9 expression and activity. The inhibition of MMP-9 protects against the development of VILI through the downregulation of neutrophil-mediated inflammation.


2006 ◽  
Vol 34 (04) ◽  
pp. 613-621 ◽  
Author(s):  
Yanning Qian ◽  
Jie Sun ◽  
Zhongyun Wang ◽  
Jianjun Yang

Sepsis is associated with the highest risk of progression to acute lung injury or acute respiratory distress syndrome. Shen-Fu has been advocated to treat many severely ill patients. Our study was designed to investigate the effect of Shen-Fu on endotoxin-induced acute lung injury in vivo. Adult male Wistar rats were randomly divided into 6 groups: controls; those challenged with endotoxin (5 mg/kg) and treated with saline; those challenged with endotoxin (5 mg/kg) and treated with Shen-Fu (1 mg/kg); those challenged with endotoxin (5 mg/kg) and treated with Shen-Fu (10 mg/kg); increase challenged with endotoxin (5 mg/kg) and treated with Shen-Fu (100 mg/kg); saline injected and treated with Shen-Fu (100 mg/kg). TNF-α, IL-6, and NF-kappa B were investigated in the lung two hours later. Myeloperoxidase (MPO) activity and wet/dry weight ratio were investigated six hours later. Intravenous administration of endotoxin provoked significant lung injury, which was characterized by increment increase of MPO activity and wet/dry lung weight ratio, and TNF-α and IL-6 expression and NF-kappa B activation. Shen-Fu (10,100 mg/kg) decreased MPO activity and wet/dry weight ratio and inhibited TNF-α and IL-6 production, endotoxin-induced NF-kappa B activation. Our results indicated that Shen-Fu at a dose of higher than 10 mg/kg inhibited endotoxin-induced pulmonary inflammation in vivo.


1999 ◽  
Vol 87 (6) ◽  
pp. 2319-2325 ◽  
Author(s):  
Masashi Kishi ◽  
Lois F. Richard ◽  
Robert O. Webster ◽  
Thomas E. Dahms

Reactive oxygen species have been shown to play an important role in the pathogenesis of lung injury. This study was designed to clarify the role of intrapulmonary neutrophils in the development of xanthine/xanthine oxidase (X/XO)-induced lung injury in isolated buffer-perfused rabbit lungs. We measured microvascular fluid filtration coefficient ( K f) and wet-to-dry weight ratio to assess lung injury. X/XO induced a significant increase in K f and wet-to-dry weight ratio in neutrophil-replete lungs, whereas the lung injury was attenuated in neutrophil-depleted lungs. A neutrophil elastase inhibitor, ONO-5046, also attenuated the lung injury. In addition, X/XO induced a transient pulmonary arterial pressure (Ppa) increase. The thromboxane inhibitor OKY-046 attenuated the Ppa increase but did not alter the increase in permeability. Neutrophil depletion reduced the K f increase but had no effect on the Ppa increase. These results suggest that intrapulmonary neutrophils activated by X/XO play a major role in development of the lung injury, that neutrophil elastase is involved in the injury, and that the X/XO-induced vasoconstriction is independent of intrapulmonary neutrophils.


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