scholarly journals Mitochondrial Coenzyme Q Protects Sepsis-Induced Acute Lung Injury by Activating PI3K/Akt/GSK-3β/mTOR Pathway in Rats

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Ruirui Li ◽  
Tao Ren ◽  
Jianqiong Zeng

The aim of our study was to assess the effects of mitochondrial coenzyme Q (MitoQ) on sepsis-induced acute lung injury (ALI) and investigate its possible mechanisms. The cecal ligation and puncture (CLP) method was used to establish a septic ALI model. Rats were randomly divided into Con group, CLP group, MitoQ group, and MitoQ + LY294002 group. The survival rate of the rats was recorded, and the survival rate curve was plotted. Moreover, the ratio of wet/dry weight (W/D) in lung tissue was measured. The activity of myeloperoxidase (MPO) was measured by using the MPO colorimetric activity assay kit. The levels of high-mobility group box 1 (HMGB1) and interleukin-6 (IL-6), macrophage inflammatory protein 2 (MIP2), and keratinocyte chemoattractant (KC) were analyzed by ELISA. The histopathological changes were measured by HE staining, and the lung injury was scored. TUNEL assay was applied to detect the apoptotic cells in lung tissue. The protein expressions were detected by western blot. MitoQ increased the survival rate and alleviated pulmonary edema in septic ALI rats. In addition, MitoQ inhibited the MPO activity and decreased the levels of HMGB1 and IL-6. After treatment with MitoQ, alveolar wall edema, inflammatory cell infiltration, and red blood cell exudation were relieved. MitoQ inhibited cell apoptosis in lung tissue of septic ALI rats. Meanwhile, MitoQ treatment remarkedly increased the expression of p-Akt, p-GSK-3β, and p-mTOR but decreased Bax, caspase-3, caspase-9, Beclin-1, and LC-3II/LC-3I. The effects of MitoQ were significantly reversed by the PI3K inhibitor (LY294002). Our study demonstrated that MitoQ could protect sepsis-induced acute lung injury by activating the PI3K/Akt/GSK-3β/mTOR pathway in rats.

2020 ◽  
Vol 19 (3) ◽  
pp. 533-539
Author(s):  
Qinghai You ◽  
Jinmei Wang ◽  
Lijuan Jiang ◽  
Yuanmin Chang ◽  
Wenmei Li

Purpose: To investigate the therapeutic effect of aqueous extract of Aconitum carmichaelii Debeaux (AEACD) on sepsis-induced acute lung injury (ALI), as well as explore the underlying mechanism of action. Methods: C57BL/6 mice were treated with AEACD by gavage (4.0 g/kg/day) for 5 days before cecal ligation and puncture (CLP) challenge. After 24 h, the pathological morphology of lung tissue and the biochemical parameters in bronchoalveolar lavage fluid (BALF) were determined by H&E staining and enzyme-linked immunosorbent assay (ELISA). Furthermore, the total protein content and lactate dehydrogenase (LDH) level of BALF, as well as the oxidative biomarkers (malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD)) were evaluated in the lung homogenates by ELISA assay. The levels of pro-inflammatory cytokines, TNFα, IL-1β, and IL-6, in lung tissue were measured by qRT-PCR or ELISA. Finally, key proteins in Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) pathway in lung tissue were evaluated by western blot. Results: CLP challenge induced abnormal changes in the histological structures of lung tissue, lung wet-to-dry weight (W/D) ratio, protein content and LDH levels of BALF, which were remarkably reversed by AEACD. In addition, AEACD decreased MDA levels, and increased GSH levels and SOD activity in the lung tissue of CLP–treated mice (p < 0.05). Furthermore, AEACD attenuated the CLP challengeinduced upregulation of TNFα, IL-1β, and IL-6. Finally, AEACD inactivated TLR4/NF-κB pathway by upregulating IκBα and downregulating TLR4 and phosphorylated-p65 levels. Conclusion: AEACD administration protects mice against sepsis-induced ALI through the regulation of oxidative stress and inflammatory responses in lung tissues. The underlying mechanism occurs by inhibiting TLR4/NF-κB signaling pathway. Keywords: Aconitum carmichaelii Debeaux, Acute lung injury, Sepsis, TLR4, NF-κB


2021 ◽  

Background: Sepsis is most likely to cause lung damage in patients, and the detection rate and mortality rate are high. Here, we investigated the expression of miR-20a in sepsis-induced acute lung injury (ALI) rats and its effect on inflammatory response, and reveal its possible molecular mechanism. Method: The model of acute lung injury caused by sepsis in rats was established by cecal ligation and puncture. The expression of miR-20a in lung tissue was determined by RT-qPCR. Acute lung injury rats were injected with 5 nmol miR-20a agomir or agomir NC every day for 3 days. Rats were sacrificed by arterial bleeding and lung tissues were removed. Serum interleukin (IL) -1β, IL-6, and tumor necrosis factor alpha (TNF-α) were detected by ELISA. HE staining was used to observe the pathology of lung tissue and calculate the pathological score of lung injury. Western blot to determine the level of TLR4 and nuclear transcription factor κB p65 (NF-κB p65) protein in lung tissue. The luciferase reporter assay was used to verify the binding effect of miR-20a on the 3 non-coding TLR4. Results: We found that compared with that in Normal group, the expression of miR-20a in lung tissues of rats with ALI was decreased (p < 0.05). In miR-20a agomir group, the plasma level of IL-1β, IL-6, and TNF-α was significantly lower than that in agomir NC group and ALI group (p < 0.05), while higher than those in Normal group (p < 0.05). The HE staining results showed that the pathological score of lung injury in rats in miR-20a agomir group was lower than that of agomir NC group and ALI group (p < 0.05). Compared with agomir NC group and ALI group, the expression of TLR4 and NF-κB p65 in miR-20a agomir group was decreased (p < 0.01). The luciferase reporting experiment confirmed that TLR4 was a target gene of miR-20a. Conclusion: To sum up, miR-20a exerts a protective effect on sepsis-induced ALI rats through its anti-inflammatory effect. The targeting of TLR4 by miR-20a may be an effective method to reduce the inflammatory response in sepsis-induced ALI.


2021 ◽  
Author(s):  
Yan-nian Luo ◽  
Nan-nan He ◽  
Juan Xu ◽  
Rui Wang ◽  
Wen Cao ◽  
...  

Abstract The present study was aimed to explore the protective role of isoacteoside (ISO) in cecal ligation and puncture (CLP)-induced acute lung injury (ALI) in mice. Mice were divided into the following groups: sham control group, ALI group, and ALI+ISO group, in which mice received 10,50 or 100 mg/kg/day of ISO for 3 days before, 0h and 12h after CLP surgery. In the first experiment, all mice were maintained until 72 h after the CLP operation to calculate the survival rate. In the second experiment, mouse serum and lung and bronchoalveolar lavage fluid (BALF) were collected 24 h after model establishment for detection. The results revealed that ISO significantly improved the ALI associated survival rate, reduced the pathological injury, ALI score, infiltration of inflammatory cells, leakage of cells and proteins into BALF, systemic and local cytokine secretion, and pulmonary oxidative stress. Moreover, ISO significantly inhibited the expression levels of the pro-inflammatory proteins TLR4, MyD88, p-NF-κB p65, p-IKKαβ, and p-IκBα and increased the expression levels of the endothelial permeability related proteins ZO-1, claudin 5 and VE-cadherin. In conclusions, ISO mitigated acute lung injury in mice which was attributed to the capacity of ISO to inhibit inflammation, oxidative stress and endothelial hyperpermeability.


2007 ◽  
Vol 293 (2) ◽  
pp. L446-L452 ◽  
Author(s):  
Takefumi Itoh ◽  
Hiroaki Obata ◽  
Shinsuke Murakami ◽  
Kaoru Hamada ◽  
Kenji Kangawa ◽  
...  

Adrenomedullin (AM), an endogenous peptide, has been shown to have a variety of protective effects on the cardiovascular system. However, the effect of AM on acute lung injury remains unknown. Accordingly, we investigated whether AM infusion ameliorates lipopolysaccharide (LPS)-induced acute lung injury in rats. Rats were randomized to receive continuous intravenous infusion of AM (0.1 μg·kg−1·min−1) or vehicle through a microosmotic pump. The animals were intratracheally injected with either LPS (1 mg/kg) or saline. At 6 and 18 h after intratracheal instillation, we performed histological examination and bronchoalveolar lavage and assessed the lung wet/dry weight ratio as an index of acute lung injury. Then we measured the numbers of total cells and neutrophils and the levels of tumor necrosis factor (TNF)-α and cytokine-induced neutrophil chemoattractant (CINC) in bronchoalveolar lavage fluid (BALF). In addition, we evaluated BALF total protein and albumin levels as indexes of lung permeability. LPS instillation caused severe acute lung injury, as indicated by the histological findings and the lung wet/dry weight ratio. However, AM infusion attenuated these LPS-induced abnormalities. AM decreased the numbers of total cells and neutrophils and the levels of TNF-α and CINC in BALF. AM also reduced BALF total protein and albumin levels. In addition, AM significantly suppressed apoptosis of alveolar wall cells as indicated by cleaved caspase-3 staining. In conclusion, continuous infusion of AM ameliorated LPS-induced acute lung injury in rats. This beneficial effect of AM on acute lung injury may be mediated by inhibition of inflammation, hyperpermeability, and alveolar wall cell apoptosis.


2022 ◽  
Author(s):  
Yibin Zeng ◽  
Hongying Zhao ◽  
Tong Zhang ◽  
Chao Zhang ◽  
Yanni He ◽  
...  

Background: Punicalagin (Pun) is one of the main bioactive compounds in pomegranate peel, it possesses many properties, including antioxidant, anti-inflammation, and immunosuppressive activities. The study was aimed to investigate the protective effect and mechanisms of Pun on lipopolysaccharide (LPS) induced acute lung injury (ALI) in mice. Methods and Results: Forty-eight BALB/c male mice were used to establish ALI by intratracheal-instilled 2.4 mg/kg LPS, the mice were randomly divided into model and Pun (10, 20, 40 mg/kg) groups. The other twelve mice were intratracheal-instilled same volume of water as control. After 2 h of receiving LPS, mice were administrated drug through intraperitoneal injection. Lung index, histopathological changes, white blood cells and biomarkers in bronchoalveolar lavage fluid (BALF) were analyzed. The protein expression of total and phosphor p65, IκBα, ERK1/2, JNK and p38 in lung tissue was detected. The result showed that Pun could reduce the lung index and wet/dry weight ratio, improve lung histopathological injury. In addition, Pun decreased the inflammation cells and regulated the biomarkers in BALF. Furthermore, Pun dose-dependently reduced the phosphor protein levels of p65, IκBα, ERK1/2, JNK and p38 in lung tissue, which exhibited that the effect of Pun related to MAPKs pathway. More importantly, there is no toxicity was observed in the acute toxicity study of Pun. Conclusion: Pun improves LPS-induced ALI mainly through its anti-inflammatory properties, which is associated with NF-κB and MAPKs signaling pathways. The study implied that Pun maybe a potent agent against ALI in future clinic.


2021 ◽  
Author(s):  
Mei-Ling Zhang ◽  
Meng Wang ◽  
Jian Chen ◽  
Yan-Jie Liu ◽  
Xiao-Hui Zheng ◽  
...  

Abstract Background: The pathological characteristics of acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) are pulmonary edema resulting from pulmonary permeability increasing. The main cause is uncontrolled inflammatory response leading to the damage of pulmonary vascular endothelial and alveolar epithelial barriers. However, there has not been effective drugs against ALI. In this study, we investigated the function of Isopropyl 3-(3, 4-dihydroxypheny l)-2-hydroxypropanoate (IDHP), a novel metabolite of Danshen dripping pill having anti-inflammatory effect, in lipopolysaccharide (LPS) induced ALI in mice, and its underlying mechanisms.Methods: Pretreatment of IDHP in LPS-induced acute lung injury in mice were observed on survival rate, pulmonary morphologic changes, total protein content in bronchoalveolar lavage fluid (BALF), and inflammatory cytokines in lung tissue and BALF. To further explore its mechanism on ALI, THP-1 macrophages was studied to analyse propotosis related proteins and co-culture with epithelial or endothelial cells to assess protection function of IDHP in vitro.Results: As revealed by survival study, pretreatment with high dose of IDHP reduced the mortality of mice from ALI. IDHP pretreatment significantly improved LPS-induced lung pathological changes, reduced protein leakage and lung myeloperoxidase activity. IDHP also inhibited the release of inflammatory mediators TNFα, IL-1β, IL-6 and IL-18 in BALF and lung tissue. Meanwhile, IDHP decreased the expression of active-caspase1 (in canonical pyroptosis pathway), caspase4/5 (non-canonical pyroptosis pathway), Nrlp3, mature IL-1β, mature IL-18, Asc speck formation, and cleaved Gsdmd, all these are required for pyroptosis, in LPS stimulated THP-1 macrophages. Moreover, IDHP also decreased ROS production in LPS-stimulated THP-1 macrophages, inhibited the expression of tight junction proteins (Occludin, Zo-1) in endothelial cells, and decreased lactate dehydrogenase activity in supernatants of epithelial or endothelial cells, co-cultured with LPS-stimulated THP-1 macrophages. Conclusions: Pretreatment of IDHP improves survival rate and ameliorates LPS-induced ALI in mice possibly via inhibiting canonical and non-canonical pyroptosis pathways.


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.


2020 ◽  
Vol 19 (9) ◽  
pp. 1815-1819
Author(s):  
Meijiao Fu ◽  
Tong Shen ◽  
Ying Yang ◽  
Yaling Zheng ◽  
Lilin Zhong

Purpose: To investigate the effect of echinacoside (ECH) on acute lung injury (ALI) and the underlying mechanism of action.Methods: The ALI model was established through intranasal instillation of lipopolysaccharide (LPS). Lung tissue damage was determined using hematoxylin and eosin (H&E) staining and lung wet-to-dry–weight ratio. Bronchoalveolar lavage fluid (BALF) protein concentration, cell count, and cytokine level were evaluated. Western blotting was used to determine protein expression level.Results: ECH attenuated lung tissue injury and lung wet-to-dry–weight ratio in the ALI model (p < 0.01). The total protein content and number of total cells, neutrophils, and macrophages increased in BALF of mice treated with LPS, but these increases were reversed by ECH treatment (p < 0.01). The levels of TNF-α and IL-1β increased in BALF and lung tissue of LPS-treated mice; however, ECH treatment decreased these changes (p < 0.01). In addition, ECH inhibited the activation of the nuclear factor-κB (NF-κB)/NLR family pyrin domain containing 3 (NLRP3) pathway in LPS-treated mice (p < 0.01).Conclusion: Echinacoside attenuates LPS-induced ALI via inactivation of the NF-κB/NLRP3 pathway, making echinacoside a potential drug for the treatment of ALI. Keywords: Echinacoside, Acute lung injury, Lipopolysaccharide, Nuclear factor-κB, NLR family pyrin domain containing 3


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Xia Liu ◽  
Fei Ai ◽  
Hui Li ◽  
Qin Xu ◽  
Liyan Mei ◽  
...  

Shenfu injection (SFI), a Chinese herbal medicine with substances extracted from Ginseng Radix et Rhizoma Rubra and Aconiti Lateralis Radix Praeparata, is widely used as an anti-inflammatory reagent to treat endotoxin shock in China. However, the mechanism of SFI in endotoxin shock remains to be illuminated. High mobility group box 1 (HMGB1), a vital inflammatory factor in the late stage of endotoxin shock, may stimulate multiple signalling cascades, including κB (NF-κB), a nuclear transcription factor, as well as tumour necrosis factor (TNF)-α and interleukin (IL)-1β, among others in the overexpression of downstream proinflammatory cytokines. An investigation into the effects of SFI on the inhibition of the HMGB1-NF-κB pathway revealed the contribution of SFI to acute lung injury (ALI) in a rat model of endotoxin shock. To assess the anti-inflammatory activity of SFI, 5 ml/kg, 10 ml/kg, or 15 ml/kg of SFI was administered to different groups of rats following an injection of LPS, and the mean arterial pressure (MAP) at 5 h and the survival rate at 72 h were measured. 24 h after LPS injection, we observed pathological changes in the lung tissue and measured the mRNA expression, production, translocation, and secretion of HMGB1, as well as the expression of the NF-κB signal pathway-related proteins inhibitor of NF-κB (IκB)-α, P50, and P65. We also evaluated the regulation of SFI on the secretion of inflammatory factors including interleukin-1 beta (IL-1β) and TNF-α. SFI effectively prevented the drop in MAP, relieved lung tissue damage, and increased the survival rate in the endotoxin shock model in dose-dependent manner. SFI inhibited the transcription, expression, translocation, and secretion of HMGB1, increased the expression of toll-like receptor (TLR4), increased the production of IκB-α, and decreased the levels of P65, P50, and TNF-α in the lung tissue of endotoxin shock rats in a dose-dependent manner. Furthermore, SFI decreased the secretion of proinflammatory cytokines TNF-α and IL-1β. In summary, SFI improves the survival rate of endotoxin shock, perhaps through inhibiting the HMGB1-NF-κB pathway and thus preventing cytokine storm.


2021 ◽  
Author(s):  
Mei-Ling Zhang ◽  
Meng Wang ◽  
Jian Chen ◽  
Yan-Jie Liu ◽  
Xiao-Hui Zheng ◽  
...  

Abstract BackgroundThe pathological characteristics of acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) are pulmonary edema resulting from pulmonary permeability increasing. The main cause is uncontrolled inflammatory response leading to the damage of pulmonary vascular endothelial and alveolar epithelial barriers. However, there has not been effective drugs against ALI. In this study, we investigated the function of Isopropyl 3-(3, 4-dihydroxypheny l)-2-hydroxypropanoate (IDHP), a novel metabolite of Danshen dripping pill having anti-inflammatory effect, in lipopolysaccharide (LPS) induced ALI in mice, and its underlying mechanisms.MethodsPretreatment of IDHP in LPS-induced acute lung injury in mice were observed on survival rate, pulmonary morphologic changes, total protein content in bronchoalveolar lavage fluid (BALF), and inflammatory cytokines in lung tissue and BALF. To further explore its mechanism on ALI, THP-1 macrophages was studied to analyse pyroptosis related proteins and co-culture with epithelial or endothelial cells to assess protection function of IDHP in vitro.ResultsAs revealed by survival study, pretreatment with high dose of IDHP reduced the mortality of mice from ALI. IDHP pretreatment significantly improved LPS-induced lung pathological changes, reduced protein leakage and lung myeloperoxidase activity. IDHP also inhibited the release of inflammatory mediators TNFα, IL-1β, IL-6 and IL-18 in BALF and lung tissue. Meanwhile, IDHP decreased the expression of active-caspase1 (in canonical pyroptosis pathway), caspase4/5 (non-canonical pyroptosis pathway), Nrlp3, mature IL-1β, mature IL-18, Asc speck formation, and cleaved Gsdmd, all these are required for pyroptosis, in LPS stimulated THP-1 macrophages. Moreover, IDHP also decreased ROS production in LPS-stimulated THP-1 macrophages, inhibited the expression of tight junction proteins (Occludin, Zo-1) in endothelial cells, and decreased lactate dehydrogenase activity in supernatants of epithelial or endothelial cells, co-cultured with LPS-stimulated THP-1 macrophages. ConclusionsPretreatment of IDHP improves survival rate and ameliorates LPS-induced ALI in mice possibly via inhibiting canonical and non-canonical pyroptosis pathways.


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