Pathological Changes Of Lung Tissue Research Articles

Protective effects of glaucocalyxin A on the airway of asthmatic mice.

The aim of this study is to investigate the protective effects of glaucocalyxin A (GLA) on airways in mouse models of asthma, concerning the inflammatory mediators, Th1/Th2 subgroup imbalance, and Toll-like receptor 4 (TLR4)/NF-κB signaling pathway. Hematoxylin and eosin/periodic acid–Schiff staining was used to observe the pathological changes in lung tissues. Inflammatory cytokine contents in the bronchoalveolar lavage fluid were detected by enzyme-linked immunosorbent assay. Protein expression levels were detected with Western blot, immunohistochemistry, and immunofluorescence. In vivo studies showed that, in ovalbumin (OVA)-induced asthmatic mouse models, the GLA treatments reduced the airway hyperresponsiveness and the secretion of inflammatory cells, declined the proliferation of goblet cells, decreased the levels of IL-4, IL-5, and IL-13, and increased the contents of interferon-γ and IL-12. Moreover, GLA inhibited the protein expression levels of TLR4, MyD88, TRAF6, and NF-κB in OVA-induced asthmatic mouse models. Further in vitro studies showed that GLA inhibited the expression of NF-κB, p-IκBα, tumor necrosis factor-α, IL-6, and IL-1β and blocked the nuclear transfer of NF-κB in lipopolysaccharide-stimulated RAW264.7 macrophages. Conclusively, GLA can inhibit the inflammatory responses in OVA-induced asthmatic mice and inhibit the release of inflammatory factors in LPS-induced RAW264.7 macrophages, which may be related to the inhibition of TLR4/NF-κB signaling pathway.

Protective effect of forsythiaside A on acute lung injury in septic rats

To observe the protective effect of forsythiaside A on acute lung injury (ALI) in septic rats. Male Sprague-Dawley (SD) rats were randomly divided into normal control group, sham operation group, sepsis model group, and forsythiaside A intervention group, with 10 rats in each group. The rats in the normal control group did not receive any intervention; the rats in the sham operation group only underwent abdominal surgery; and those in the model group and forsythiaside A intervention group received cecal ligation and puncture (CLP) to establish the sepsis rat model. The rats in the forsythiaside A intervention group were given 75 mL/kg of forsythiaside A within 0.5 hour after operation, and repeated after 6 hours. The rats in the sham operation group and model group were given the same amount of normal saline at the same time points. The lung tissues were collected for pathological examination 12 hours after operation. The lung homogenate was prepared, and enzyme-linked immunosorbent assay (ELISA) was used to detect tumor necrosis factor-α (TNF-α), interleukins (IL-1β, IL-6). The activity of superoxide dismutase (SOD) was detected by xanthine oxidase method, and the content of malonaldehyde (MDA) was detected by colorimetry. The expression of nuclear factor-κB p65 (NF-κB p65) was detected by Western blotting. There was no significant pathological change of lung tissue in both normal control group and sham operation group, and there was no significant difference in each parameter between the two groups. The rats in the model group had interstitial infiltration of inflammatory cells, alveolar structure destruction, alveolar septum thicken, extensive alveolar hemorrhage, telangiectasia; the levels of TNF-α, IL-1β, IL-6, MDA and NF-κB p65 protein expression in lung tissue were significantly higher than those in the normal control group and sham operation group [TNF-α (ng/L): 132.81±16.15 vs. 45.08±5.98, 46.10±6.72, IL-1β (ng/L): 137.32±15.22 vs. 51.03±7.89, 50.92±8.13; IL-6 (ng/L): 138.39±14.28 vs. 51.68±7.03, 52.48±7.36; MDA (kU/g): 1.79±0.13 vs. 0.96±0.05, 0.97±0.05; NF-κB p65 protein (NF-κB p65/GAPDH): 2.82±0.23 vs. 1.76±0.12, 1.82±0.13; all P < 0.05], the activity of SOD decreased significantly (kU/g: 45.90±5.46 vs. 92.11±10.13, 93.36±10.56, both P < 0.05). The changes in lung histopathology in the forsythiaside A intervention group were obviously improved as compared with the model group, which showed less inflammatory cell infiltration, less alveolar septum thickening, less bleeding and more intact structures; the levels of TNF-α, IL-1β, IL-6, MDA and the expression of NF-κB p65 protein in lung tissue were significantly lower than those in the model group [TNF-α (ng/L): 72.48±9.78 vs. 132.81±16.15, IL-1β (ng/L): 83.85±12.46 vs. 137.32±15.22, IL-6 (ng/L): 81.88±11.89 vs. 138.39±14.28, MDA (kU/L): 1.29±0.09 vs. 1.79±0.13, NF-κB p65 protein (NF-κB p65/GAPDH): 2.29±0.19 vs. 2.82±0.23, all P < 0.05], SOD activity increased significantly (kU/g: 66.03±7.98 vs. 45.90±5.46, P < 0.05). Forsythiaside A can effectively alleviate ALI in septic rats. The mechanism may be related to down-regulate the expression of NF-κB p65 and reduce the level of inflammatory factors and free radicals in lung tissue, thereby against acute lung injury in septic rats.

MiR-146a-5p Attenuates Allergic Airway Inflammation by Inhibiting the NLRP3 Inflammasome Activation in Macrophages

Objective: Asthma is a common inflammatory respiratory disease with increasing incidence worldwide. This study aimed to investigate the mechanism of miR-146a-5p in reducing allergic airway inflammation by inhibiting NLRP3 inflammasome activation in macrophages. Methods: Allergic mouse models were established by ovalbumin stimulation, and mice were treated with miR-146a-5p agomir and oe-TIRAP 3 h before OVA stimulation. The pathological changes of lung tissues were observed by hematoxylin-eosin staining. The airway hyperresponsiveness of mice were examined. The miR-146a-5p level was detected by RT-qPCR. The inflammatory cytokines (IL-18/TNF-α) and anti-inflammatory cytokine IL-10 levels in bronchoalveolar lavage fluid and serum IgE levels were examined by ELISA. Airway inflammation in mice was detected after miR-146a-5p overexpression. The levels of NLRP3/ASC/caspase1 proteins and macrophage M1/M2 surface markers in mouse lung tissues were examined using immunohistochemistry, Western blot, and flow cytometry. The targeting relationship between miR-146a-5p and TIRAP was verified by dual-luciferase assay. The p65 levels in the cytoplasm/nucleus of mouse lung tissue were measured. Results: miR-146a-5p was downregulated in the lung tissues of allergic mice, and miR-146a-5p overexpression alleviated airway inflammation in asthmatic mice. miR-146a-5p suppressed NLRP3 inflammasome activation in macrophages of allergic mice, reduced NLRP3/ASC/caspase1 protein levels in lung tissues, blocked M1 polarization, and promoted M2 polarization. miR-146a-5p targeted TIRAP. TIRAP overexpression partially reversed the promoting effect of miR-146a-5p on M2 polarization. miR-146a-5p can inhibit the activation of the TIRAP/NF-κB pathway. Conclusion: miR-146a-5p inhibited NLRP3 inflammasome activation in macrophages in the lung tissue of allergic mice, prevented pro-inflammatory phenotype M1 polarization, and promoted anti-inflammatory phenotype M2 polarization by targeting the TIRAP/NF-κB pathway, thus alleviating airway inflammation in allergic asthma.

Pristimerin alleviates cigarette smoke-induced inflammation in chronic obstructive pulmonary disease via inhibiting NF-κB pathway.

Cigarette smoke (CS) is a risk factor for chronic obstructive pulmonary disease (COPD), which can exacerbate inflammation and oxidative stress. Pristimerin (Pris) is a natural compound with antioxidant and anti-inflammatory effects. We managed to evaluate the protective effects of Pris on CS-induced COPD. The CS-induced COPD mice model and cell model were constructed. The effects of Pris treatment on lung function, inflammatory cell infiltration, myeloperoxidase (MPO), and pathological changes of lung tissues in mice model were evaluated. The impacts of Pris treatment on inflammatory factors, chemokines, and oxidative stress parameters in mice lung tissues and cells were determined by kits. The viability of human bronchial epithelial cells after Pris treatment was tested by CCK-8. The activation of NF-κB pathway was confirmed by Western blot and immunofluorescence. CS treatment impaired lung function, reduced weight of mice, and enhanced inflammatory cell infiltration, MPO, and lung tissue damage, but these effects of CS were reversed by Pris treatment. Furthermore, Pris treatment downregulated the levels of malondialdehyde, IL-6, IL-1β, TNF-α, CXCL1, and CXLC2, but upregulated superoxide dismutase and catalase levels. Pris treatment could overturn CS-induced activation of the NF-κB pathway. Pris alleviates CS-induced COPD by inactivating NF-κB pathway.

Role and mechanism of signal transducer and activator of transcription protein STAT1/3/5 in hyperoxia-induced acute lung injury

To investigate whether signal transducer and activator of transcription (STAT1/3/5) have a protective effect on hyperoxia-induced acute lung injury (HALI) and its mechanism. Seventy C57BL/6J mice were randomly divided into five groups: normoxia control group, HALI group, and STAT1/3/5 inhibitor groups, with 14 mice in each group. The HALI model was established by exposure to more than 90% hyperoxia for 48 hours; three STAT inhibitor groups were pretreated by intraperitoneal injection of STAT1 inhibitor 40 mg/kg and STAT3 inhibitor 5 mg/kg, and STAT5 inhibitor 10 mg/kg for 1 week. Six blood samples were randomly collected from each group, and microRNA-21 (miR-21) expression was measured by quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR). Lung tissue of the sacrificed mice was obtained, and enzyme linked immunosorbent assay (ELISA) was used to detect the contents of tumor necrosis factor-α (TNF-α), interleukins (IL-6, IL-1β), superoxide dismutase (SOD), malonic dialdehyde (MDA), and matrix metalloproteinase 9 (MMP9). The water content of lung tissue was calculated. The pathological changes in lung tissue were observed under the light microscope, and the pathological score of lung injury was performed. Western blotting was used to detect the expression of phosphorylated STAT (p-STAT1, p-STAT3, p-STAT5) in lung tissue. The 7-day cumulative survival rates of the remaining 8 mice in each group were analyzed using Kaplan-Meier survival curves. Under the light microscope, the alveolar structures in the HALI group and the STAT1 inhibitor group were destroyed, a large number of neutrophils (NEU) infiltrated in the alveoli and lung interstitium, which were thickened. The pathological score of lung injury and the water content of the lung tissue was significantly increased. In STAT3 inhibitor and STAT5 inhibitor groups, the alveolar cavity was clear, the degree of NEU infiltration and the thickness of lung interstitium were lower than those in HALI group, the pathological score of lung injury and the water content of lung tissue were significantly decreased, especially in STAT3 inhibitor group. Compared with the normoxia control group, the contents of TNF-α, IL-6, IL-1β, MDA, and MMP9, and the expression levels of p-STAT3 and p-STAT5 in the HALI group were significantly increased. In contrast, the content of SOD and the expression of miR-21 were significantly decreased. Compared with the HALI group, the contents of TNF-α, IL-6, IL-1β, MDA, and MMP9 in the STAT3 inhibitor group and STAT5 inhibitor group were significantly decreased. At the same time, the content of SOD and the expression of miR-21 were significantly increased, especially in STAT3 inhibitor group [TNF-α (μg/L): 42.53±3.25 vs. 86.36±5.48, IL-6 (ng/L): 68.46±4.28 vs. 145.00±6.89, IL-1β (μg/L): 28.74±3.53 vs. 68.00±5.64, MDA (μmol/g): 20.33±2.74 vs. 42.58±3.45, and MMP9 (ng/L): 128.55±6.35 vs. 325.13±6.65, SOD (kU/g): 50.53±4.19 vs. 22.53±3.27, miR-21 (2-ΔΔCt): 0.550±0.018 vs. 0.316±0.037, all P < 0.05]. Kaplan-Meier survival curve analysis showed that the 7-day cumulative survival rates of the STAT3 inhibitor group and STAT5 inhibitor group were significantly higher than those of the HALI group [62.5% (5/8), 37.5% (3/8) vs. 12.5% (1/8), both P < 0.05]. Inhibition of STAT3 hyperactivation may suppress the inflammatory response, regulate oxidative stress, improve lung permeability through regulating the expression of miR-21, which exert lung protection in HALI.

Lung lever after COVID-19: clinical-X-ray, surgical and morphological characteristics

MATERIALS AND METHODS. Preliminary clinical and morphological analysis of a group of patients with various post-COVID complications and with surgical treatment was performed. For the period 2020-2021 in the clinic of thoracic surgery of the SI “National institute of phthisiology and pulmonology named after F.G. Yanovsky of the NAMS of Ukraine” 12 patients were treated who had coronavirus disease (COVID-19) in anamnesis and underwent surgery for COVID-19 complications.&#x0D; RESULTS AND DISCUSSION. Data on the type of surgery, X-ray conclusion and preliminary clinical diagnoses of patients with post-COVID pulmonary complications are presented. At the time of surgical treatment, according to clinical data, 4 (22.2 %) patients were diagnosed with lung abscess, 4 (22.2 %) patients had a disseminated process in the lungs of unclear origin, 2 (11.0 %) – a solitary formation of the lung, one (5.5 %, respectively) observation – spontaneous pneumothorax and suspected tumor of the lung. The results of the histopathological conclusion on the operative material and the final clinical diagnosis in the group of patients with atypical lung lesions after COVID-19 are presented. The results of histopathological examination showed that after 3 months and more after recovery from COVID-19 in some patients there are persistent pathological changes in lung tissue of various characters, and quantitatively among them prevail cases of various pathologies associated with damage to the vascular bed of the lungs.&#x0D; CONCLUSIONS. In most cases of pulmonary complications after suffering COVID-19, preliminary clinical diagnoses did not fully correspond to the identified pathological process. Morphological examination of the operative material of patients with a history of COVID-19 and postcocious complications associated with the lungs, found that vascular pulmonary pathology predominates: persistent microvasculitis of small blood vessels, pulmonary infarction, metacarpal metaplasia, secondary vascular malformation.

Yanghe Decoction Effectively Alleviates Lung Injury and Immune Disorder in Asthmatic Mice Induced by Ovalbumin.

Objective To probe into the ameliorative effect of Yanghe Decoction on pulmonary injury and immunologic derangement in asthmatic mice. Methods C57BL/6 mice were randomized into control (Con), Model, and Yanghe Decoction (YHF) groups, with 12 in each. The asthma model of adult female mice was induced by ovalbumin in the Model group, and the YHF group was treated by Yanghe Decoction on the basis of asthma modeling. The Con group received the same amount of normal saline. Inspiratory resistance (Ri), expiratory resistance (Re), lung compliance (CL), and maximal voluntary ventilation (MVV) were measured after modeling. Lung tissue was collected for the measurement of interleukin (IL)-4, IL-5, IL-6, IL-10, IL-13, and tumor necrosis factor-α (TNF-α) by ELISA kits. Combined with HE staining and PAS staining, the pathological alterations of the lung in each group were observed, and CD4+, Th2, and Th1 contents were determined by flow cytometry (FCM). Results The pulmonary function (PF) test revealed notably reduced Ri and Re as well as enhanced CL and MVV in asthmatic mice after the application of Yanghe Decoction. Yanghe Decoction dramatically ameliorated the pathological changes of lung tissue in asthmatic mice, as demonstrated by the staining results. ELISA results showed that Yanghe Decoction validly reduces lung tissue IL-4, IL-5, IL-6, IL-13, TNF-α and upregulates IL-10 in asthmatic mice. FCM indicated that Yanghe Decoction obviously reduced the number of Th1 and Th2 cells in asthmatic mice, although it caused the decrease of CD4+ cells, but the difference was not statistically significant. Conclusions Yanghe Decoction can effectively ameliorate the inflammatory reaction, immune cell disorder, and PF injury in ovalbumin-induced asthmatic mice.

Maresin-2 alleviates allergic airway inflammation in mice by inhibiting the activation of NLRP3 inflammasome, Th2 type immune response and oxidative stress

Asthma is a chronic inflammatory disease of the respiratory system. Maresin-2 (MaR2) is biosynthesized from docosahexaenoic acid (DHA) by macrophages, display strong anti-inflammatory and pro-resolving activity. To investigate the therapeutic effect and mechanism of MaR2 on asthmatic mice induced by ovalbumin (OVA) in conjunction with the adjuvant aluminum hydroxide. Twenty four female BALB/c mice were randomly divided into control, OVA, OVA + MaR2, and OVA + dexamethasone (Dexa) groups. MaR2 or Dexa were given as a treatment for OVA-induced asthma. Serum, bronchoalveolar alveolar lavage fluid (BALF) and lung tissue were collected for further analysis. The Pathological changes of lung tissue, proportion of inflammatory cells in BALF, levels of inflammatory cytokines in BALF or serum, oxidative stress indices, and the protein concentration of ASC, MPO, Ly-6G, ICAM-1, NLRP3 and Caspase-1 in lung tissues were evaluated. Compared with the OVA group, both OVA + MaR2 and OVA + Dexa group had reduced inflammation and mucus secretion in lung tissue, number of inflammatory cells in BALF, levels of related inflammatory cytokines in serum or BALF, and expressions of ASC, MPO, Ly-6G, ICAM-1, NLRP3 and Caspase-1 proteins in lung tissue. In addition, the oxidative stress was alleviated as indicated by decreased MDA, and elevated SOD and GSH. MaR2 has an obvious protective effect on OVA-induced bronchial asthma in mice, in a similar manner as Dexa. The mechanism may be related to the inhibition of the Th2 type immune response, the NLRP3 inflammasome activation and oxidative stress.

Mechanism of chlorogenic acid reducing lipopolysaccharide-induced acute lung injury in mice by regulating miR-223/NLRP3 axis.

Chlorogenic acid has various physiological activities such as antibacterial, anti-inflammatory, and antiviral activities. Studies have shown that chlorogenic acid can alleviate the inflammatory response of mice with acute lung injury (ALI), but the specific mechanism is still unclear. This study aims to investigate whether chlorogenic acid attenuates lipopolysaccharide (LPS)-induced ALI in mice by regulating the microRNA-223 (miR-223)/nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) axis. SPF grade BALBc male mice were randomly divided into a control group, a model group, a chlorogenic acid group, a chlorogenic acid+miR-223 negative control (miR-223 NC) group, and a chlorogenic acid+miR-223 inhibitor (miR-223 antagomir) group, 10 mice in each group. Except the control group, the other groups were instilled with 4 mg/kg LPS through the airway to establish the ALI mouse model. After the modeling, the mice in the chlorogenic acid group were continuously given chlorogenic acid (100 mg/kg) by gavage for 7 d. The chlorogenic acid+miR-223 NC group and the chlorogenic acid+miR-223 antagomir group were given 100 mg/kg chlorogenic acid by gavage every day, and then were injected with 10 μL of miR-223 NC (0.5 nmol/μL) and miR-223 antagomir (0.5 nmol/μL) respectively for 7 consecutive days.The control group and the model group were replaced with normal saline. The lung tissues of mice were taken to measure the ratios of lung wet to dry weight (W/D). The bronchoalveolar lavage fluid of mice was collected to measure the levels of TNF-α, IL-6, and IL-1β by ELISA kit and to count the number of eosinophils (EOS), lymphocytes, neutrophils under light microscope. After HE staining, the pathological changes of lung tissues were observed and lung injury was scored. qRT-PCR method were used to determine the expression levels of miR-223 in lung tissues. Western blotting was used to determine the expression levels of NLRP3 protein in mouse lung tissues. Luciferase reporter assay was used to analyze the targeting relationship of miR-223 to NLRP3. Compared with the control group, the lung W/D value, the lung injury score and the level of inflammatory factors in the bronchoalveolar lavage fluid were significantly increased in the model group (all P<0.05); the infiltration of inflammatory cells in the lung tissue was severe; the alveolar space was significantly increased; the alveolar wall was significantly thickened; the number of EOS, lymphocytes, and neutrophils in the bronchoalveolar lavage fluid was significantly increased (all P<0.05); the expression levels of miR-223 in lung tissue were significantly decreased (P<0.05); and the protein expression levels of NLRP3 were significantly increased (P<0.05). Compared with the model group, the W/D value of lungs, lung injury score, and levels of inflammatory factors in bronchoalveolar lavage fluid were significantly decreased in the chlorogenic acid group, the chlorogenic acid+miR-223 NC group, and the chlorogenic acid+miR-223 antagomir group (all P<0.05); lung tissues damage was alleviated; the numbers of EOS, lymphocytes, and neutrophils in bronchoalveolar lavage fluid were significantly decreased (all P<0.05); the expression levels of miR-223 in lung tissues were significantly increased (P<0.05); and the expression levels of NLRP3 protein were significantly decreased (P<0.05). Compared with the chlorogenic acid group, the lung W/D value, lung injury score, and inflammatory factor levels in the bronchoalveolar lavage fluid were significantly increased in the chlorogenic acid+miR-223 antagomir group (all P<0.05); lung tissue damage was aggravated; the number of EOS, lymphocytes and neutrophils in bronchoalveolar lavage fluid significantly increased (all P<0.05); the expression levels of miR-223 in lung tissues were significantly decreased (P<0.05); and the expression levels of NLRP3 protein were significantly increased (P<0.05). The results of luciferase reporter assay showed that miR-223 had a targeting relationship with NLRP3. Chlorogenic acid may increase the level of miR-223, target the inhibition of NLRP3 expression, reduce LPS-induced inflammatory response in ALI mice, and alleviate pathological damage of lung tissues.

The activation of SIRT3 by dexmedetomidine mitigates limb ischemia-reperfusion-induced lung injury.

BackgroundThe lung is one of the most sensitive organs, and is vulnerable to injury caused by limb ischemia-reperfusion (LIR). Dexmedetomidine, an anesthetic adjunct, has been shown to have therapeutic effects on lung injury secondary to LIR. This study aimed to investigate the role of dexmedetomidine in ameliorating LIR-induced lung injury in a mouse model of bilateral hind LIR.MethodsIn this study, 75 mice were randomly divided into 5 groups to prepare the LIR model. After the model was established, arterial blood was extracted for blood gas analysis. The pathological changes of lung tissue, lung wet/dry weight ratio, arterial blood gas analysis, detection of myeloperoxidase (MPO) activity, the content of reactive oxygen species (ROS), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) in oxidative stress indexes, mitochondrial membrane potential (MMP), adenosine triphosphate (ATP) content and cytochrome c content were measured, and the relative protein expression levels of sirtuin-3 (SIRT3) and apoptosis factor Bcl-2 related X protein (Bax), B-cell Lymphoma 2 (Bcl-2), cleaved caspase 3, and nuclear factor erythroid 2-related factor 2 (Nrf2) and cytoplasmic heme oxygenase-1 (HO-1).ResultsPretreatment with dexmedetomidine dramatically ameliorated LIR-induced lung injury, the wet/dry weight ratio, the arterial blood gas parameters, and enhanced SIRT3 expression. Moreover, dexmedetomidine significantly inhibits ROS and MDA level and restores antioxidant enzyme activities (SOD, GSH-Px). Of note, dexmedetomidine suppressed LIR-induced lung tissue apoptosis by modulating apoptosis-associated protein such as Bax, Bcl-2, and cleaved caspase 3. Moreover, dexmedetomidine inhibited the LIR-induced decreases in MMP, ATP levels, and the release of cytochrome c of LIR to maintain mitochondrial function. Latest study has shown that activating Nrf2 could promote SIRT3 expression to alleviate IR injury. Intriguingly, dexmedetomidine could facilitate nuclear Nrf2 and cytoplasmic HO-1 expression.ConclusionsOur findings suggest that dexmedetomidine protects against LIR-induced lung injury by inhibiting the oxidative response, mitochondrial dysfunction and apoptosis. The mechanism appears to be at least partly mediated through the upregulation of SIRT3 expression.

Comparative Study of Radiation-induced Lung Injury Model in Two Strains of Mice.

Radiation-induced lung injury (RILI) is a common complication of radiotherapy for thoracic tumor. Its incidence rate is as high as 20%. At present, there is no effective treatment in clinical practice. However, to study the mechanism of radiation-induced lung injury, we should first establish an appropriate animal model. In a series of scientific studies on RILI, mice are the animals most often chosen by researchers. However, there are few reports on which strain of mice is more suitable as a model of RILI. In this study, Kunming (KM) and C57BL/6 strains of mice were used as research objects to find the most suitable mice to replicate the RILI model. C57BL/6 mice and KM mice were exposed to irradiation at a dose of 20 Gy. The lung tissue of C57BL/6 mice exposed to radiation showed dilation and hyperemia of capillaries, infiltration of inflammatory cells, and thickening of alveolar septum, while the lung tissue of KM mice exposed to radiation was not as obvious as that of C57BL/6 mice. After irradiation, the expression of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in the lung tissue of C57BL/6 mice was significantly increased, while the expression of IL-6 and TNF-α in KM mice was almost unchanged. These studies showed that C57BL/6 mice are more suitable for the model of radiation-induced lung injury because of sensitive inflammatory reaction and the pathological changes of lung tissue.

Shufeiya Recipe Improves Monocrotaline-Induced Pulmonary Hypertension in Rats by Regulating SIRT3/FOXO3a and Its Downstream Signaling Pathways.

Pulmonary hypertension (PH) is a chronic and progressive disease caused by obstructions and functional changes of small pulmonary arteries. Current treatment options of PH are costly with patients needing long-term taking medicine. The traditional Chinese medicine (TCM) compound “Shufeiya Recipe” was used to intervene in monocrotaline- (MCT-) induced pulmonary hypertension in rats. The rats were randomly divided into the control group, model group, positive drug (Sildenafil) group, and Shufeiya Recipe low-, moderate-, and high-dose groups. The improvement effect of the Shufeiya Recipe on the mean pulmonary artery pressure (mPAP) was assessed in PH rats, and pathological staining was used to observe the pathological changes of lung tissue. The impact of the Shufeiya Recipe on oxidative stress damage in rats with pulmonary hypertension and the regulation of SIRT3/FOXO3a and its downstream signaling pathways were determined. The results showed that Shufeiya Recipe could significantly downregulate mPAP and improve lung histopathological changes; downregulate serum levels of reactive oxygen species (ROS); upregulate the concentrations of COX-1 and COX-2 and the activity of Mn-SOD; inhibit oxidative response damage; promote the protein expression of SIRT3, FOXO3a, p-PI3K, p-AKT, and p-eNOS; increase the level of expression of NO, sGC, cGMP, and PKG; and downregulate the level of protein expression of Ras, p-MEK1/2, p-ERK1/2 and c-fos. These results indicate that Shufeiya Recipe can improve MCT-induced pulmonary hypertension in rats by regulating SIRT3/FOXO3a and its downstream PI3K/AKT/eNOS and Ras/ERK signaling pathways.

Electroacupuncture Alleviates LPS-Induced ARDS Through α7 Nicotinic Acetylcholine Receptor-Mediated Inhibition of Ferroptosis.

Acute respiratory distress syndrome (ARDS) is an uncontrollable, progressive pulmonary inflammatory disease, and as a common clinical critical disease, there is no effective treatment available. Electroacupuncture (EA) therapy is a type of traditional Chinese medicine physiotherapy that can alleviate the inflammatory response. However, the potential mechanism of EA in the treatment of ARDS is not yet clear. Ferroptosis is a new type of programmed cell death characterized by intracellular iron accumulation and lipid peroxidation. Recently, emerging evidence has shown that ferroptosis is closely related to the occurrence and development of ARDS caused by various pathological factors. Here, we further investigated whether EA-mediated inhibition of ferroptosis in lung tissue could attenuate lipopolysaccharide (LPS)-induced ARDS and explored its underlying mechanisms. In this study, mice were administered LPS intraperitoneally to establish a model of LPS-induced ARDS. We found that EA stimulation could not only reduce the exudation of inflammatory cells and proteins in the alveolar lumen but also significantly alleviate the pathological changes of lung tissue, inhibit the production of proinflammatory cytokines and improve the survival rate of mice. Concurrently, we also found that ferroptosis events occurred in the lung tissue of LPS-induced ARDS mice, manifested by elevated iron levels, ROS production and lipid peroxidation. Intriguingly, our results showed that EA stimulation at the Zusanli (ST36) acupoint activated α7 nicotinic acetylcholine receptor (α7nAchR) in lung tissue mainly through the sciatic nerve and cervical vagus nerve, thus exerting anti-ferroptosis and pulmonary protective effects. Additionally, these effects were eliminated by methyllycaconitine (MLA), a selective antagonist of α7nAchR. In vitro experiments, activation of α7nAchR protected alveolar epithelial cells from LPS-induced ferroptosis. Furthermore, our experiments showed that the pulmonary protective effects of EA stimulation were effectively reversed by erastin, a ferroptosis activator. Collectively, we demonstrated that EA stimulation could alleviate LPS-induced ARDS by activating α7nAchR to inhibit LPS-induced ferroptosis in alveolar epithelial cells. Targeting and regulating ferroptosis in alveolar epithelial cells may be a potential intervention approach for the treatment of LPS-induced ALI/ARDS in the future.

Propofol Regulates the Expression of BecliN-1 through miR-30b and Protects against Lung Ischemia-Reperfusion Injury.

Pulmonary ischemia-reperfusion can cause severe dysfunction of alveolar epithelium and alveolar cells. Drugs such as propofol have a protective effect on lung ischemia-reperfusion, but this protective mechanism is not stable and requires other factors such as nucleosides. The purpose of this article is to study the protective mechanism of propofol on lung ischemia-reperfusion injury by regulating the expression of BecliN-1 by miR-30b. With 72 male rats as the research object, a rat lung ischemia-reperfusion model was established. Phenol agents were perfused as the perfusion solution to detect the expression levels of miR-30b and BecliN-1, statistical experimental data and analyze the regulatory mechanism of miR-30b on the expression of BecliN-1 and the effect of propofol on the protection of lung ischemia-reperfusion. Research results show that propofol can reduce inflammation, reduce oxidative stress, inhibit lung tissue apoptosis, improve lung function and pathological changes of lung tissue by inhibiting the activation of the JAK-STAT signaling pathway, and propofol can pass. The protection of miR-30b's regulation of BecliN-1 expression against lung ischemia-reperfusion injury is 30% higher than that of other protective mechanisms. At the same time, the apoptosis rate of inflammatory lung tissue cells is reduced by 13%.

Concentrations, seasonal trends, sources, health risk and subchronic toxicity to the respiratory and immune system of PAHs in PM2.5 in Xi'an

PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) have been proved to be hazardous to health. Previous studies have focused on the distribution and sources of PAHs, whereas there is little knowledge of the damage to organs. Here we sought to investigate the pollution level and seasonal variation characteristics of PAHs in PM2.5 in Xi’an and assess the health risk, to establish a PAHs exposure model, and investigate the toxicological effects of PAHs on the respiratory and immune functions. A sub-chronic exposure model of PAHs was established by inhalation. The pathological changes of lung tissues were observed with a light microscope. Inflammatory reactions in alveolar lavage fluid were determined using the corresponding kit. The levels of interleukin-6 (IL-6) and interleukin-8 (IL-8) were detected with enzyme linked immunosorbent assay (ELISA) kit; the proliferation of lymphocytes in spleen was detected with methyl tetrazolium (MTT); DNA immune damage was determined with DNA gel electrophoresis. The results showed that (1) the total concentration of 16 PAHs ranged from 41.1 to 387 ng/m3, with a mean value of 170 ng/m3, and the concentration of PAHs in PM2.5 was higher in winter than in other seasons. (2) The sources of PAHs in the atmosphere of Xi’an urban area were mainly coal combustion, and the equivalent carcinogenic concentration of PAHs in PM2.5 was 3.9 ng/m3. (3) Foreign body granuloma formation and inflammatory cell damage were observed in the lungs of rats infected with toxin; the levels of reactive oxygen species (ROS) and mobile device assistant (MDA) increased while nitric oxide synthase (NOS) decreased with the increase of dose; the expression levels of IL-6 and IL-8 elevated with the increase of toxin dose, showing an obvious dose-effect relationship; the level of PAHs damage to cells showed a dose-effect relationship. Sub-chronic exposure to PAHs could cause sustained inflammatory injury to the organism. Measures should be taken to counter the problems of PAHs in PM2.5 in Xi’an and relevant health promotion strategies should be developed.

Endothelial Microparticles Derived from Primary Pulmonary Microvascular Endothelial Cells Mediate Lung Inflammation in Chronic Obstructive Pulmonary Disease by Transferring microRNA-126.

BackgroundExtracellular vesicles (EVs) are considered to new types of intercellular communication media, and microRNA is one of the most common transferring components of EVs. This study aimed to explore the potential role of endothelial microparticles (EMPs) derived from primary pulmonary microvascular endothelial cells in regulating lung inflammation of chronic obstructive pulmonary disease (COPD) through transferring microRNA-126 (miR-126).MethodsEMPs generated from primary pulmonary microvascular endothelial cells were isolated by gradient centrifugation and characterized by transmission electron microscopy, flow cytometry and Western blotting. EMPs were treated to in vitro and in vivo COPD models induced by cigarette smoke extract (CSE). miR-126 mimics or inhibitors were transfected into EMPs by calcium chloride. Pathological changes of lung tissue, mRNA and protein levels of inflammation-related factors were measured to explore the effect of EMPs transferring miR-126 on CSE-induced inflammation.ResultsBoth in vitro and in vivo studies demonstrated that mRNA and protein levels of inflammation-related factors were significantly increased in COPD group, while EMPs could dramatically reverse these increases. In vitro, overexpression of miR-126 in EMPs decreased HMGB1 expression and magnified the decreasing effect of EMPs on inflammation-related factors.ConclusionThe present study reveals that EMPs are capable of alleviating lung inflammation and transferring miR-126 can magnify the anti-inflammatory effect of EMPs, which may provide a novel therapeutic alternative for COPD.

Active components of Descurainia sophia improve lung permeability in rats with allergic asthma by regulating airway inflammation and epithelial damage

The present study investigated the effect of active components of Descurainia sophia on allergic asthma and explored the underlying mechanism. SD male rats were randomly divided into a normal group(NC), a model group(M), a D. sophia decoction group(DS), a D. sophia fatty oil group(FO), a D. sophia flavonoid glycoside group(FG), a D. sophia oligosaccharide group(Oli), and a positive drug dexamethasone group(Y). The allergic asthma model was induced in rats by intraperitoneal injection of ovalbumin(OVA) and aluminum hydroxide gel adjuvant(sensitization) and atomization of OVA solution(excitation). After modeling, asthma-related indicators, tracheal phenol red excretion, inflammatory cell levels in the peripheral blood, lung permeability index(LPI), and oxygenation index(OI) of rats were detected. The pathological changes of lung tissues were observed by HE staining. Enzyme-linked immunosorbent assay(ELISA) was used to detect the content of inflammatory factors immunoglobulin E(IgE), interleukin-4(IL-4), and interferon-γ(IFN-γ) in the bronchoalveolar lavage fluid(BALF) and the content of endothelin-1(ET-1) and angiotensin-converting enzyme(ACE) in lung tissue homogenate. The serum content of nitric oxide(NO) was detected by colorimetry. Western blot was employed to determine the protein expression of Toll-like receptor 4(TLR4), nuclear factor κB-p65(NF-κB-p65), phosphorylated NF-κB-p65(p-NF-κB-p65), myosin light chain kinase(MLCK), vascular endothelial cadherin(VE cadherin), connexin 43, and claudin 5, and the mechanism of active components of D. sophia on allergic asthma was explored. As revealed by the results, the M group showed extensive infiltration of inflammatory cells around the bronchus of the lung tissues of the allergic asthma rats, thickened bronchial wall, severely deformed alveolar structure, increased number of wheezes, the content of IgE, IL-4, ET-1, and ACE, inflammatory cells, and LPI, and reduced latency of asthma, tracheal phenol red excretion, IFN-γ, NO content, and OI. After the intervention of the active components of D. sophia, the DS, FO, FG, Oli, and Y groups showed improved asthma-related indicators, tracheal phenol red excretion, and lung tissue lesions in allergic asthma rats, and the effects in the FO and Oli groups were superior. The content of inflammatory factors in BALF was recovered in the DS, FO, and Y groups and the FG and Oli groups. The number of inflammatory cells in rats was reduced in the DS and FO groups, and the FG, Oli, and Y groups to varying degrees, and the effect in the FO group was superior. DS, FO, Oli, and Y reduced ET-1, ACE, and LPI and increased NO and OI. FG recovered NO, ET-1, ACE, LPI, and OI to improve lung epithelial damage and permeability. Further investigation of inflammation-related TLR4/NF-κB pathways, MLCK, and related skeleton protein levels showed that TLR4, NF-κB-p65, p-NF-κB-p65, and MLCK levels were increased, and VE cadherin, connexin 43, and claudin 5 were reduced in the M group. DS, FO, FG, Oli, and Y could reduce the protein expression related to the TLR4 pathway to varying degrees, and regulate the protein expression of MLCK, VE cadherin, connexin 43, and claudin 5. It is inferred that the active components of D. sophia improve lung permeability in rats with allergic asthma presumedly by regulating the TLR4/NF-κB signaling pathway to improve airway inflammation, mediating MLCK and connexin, and regulating epithelial damage.

Role and Mechanism of miR-181a-5p in Mice with Chronic Obstructive Pulmonary Disease by Regulating HMGB1 and the NF-κB Pathway

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease. This study explored the mechanism of miR-181a-5p in the inflammatory response in COPD mice. COPD mouse models were established by cigarette smoke (CS) exposure following pretreatment with recombinant adeno-associated virus (rAAv)-miR-181a-5p, si-HMGB1 (high mobility group box 1), and NF-κB pathway inhibitor PDTC, respectively. Pathological changes of lung tissues were determined by HE staining. Bronchoalveolar lavage fluid was collected to count total cells, neutrophils, and lymphocytes using a Countess II automatic cell counter. Expressions of neutrophil elastase (NE) and inflammatory factors (TNF-α, IL-6, IL-8, and IFN-γ) were detected by ELISA. Binding relationship between miR-181a-5p and HMGB1 was predicted on starBase and validated by dual-luciferase assay. miR-181a-5p expression was detected by RT-qPCR, and expressions of HMGB1, IκBα, and p-IκBα were detected by western blot. The expression level of miR-181a-5p was lower in lung tissues. miR-181a-5p overexpression alleviated inflammatory response and pathological changes of lung tissues in COPD mice, with decreased pulmonary inflammation scores, total cells, neutrophils, and lymphocytes and expressions of NE and inflammatory factors. HMGB1 expression level was increased in COPD mice. miR-181a-5p targeted HMGB1. si-HMGB1 relieved inflammatory responses in COPD mice. NF-κB was activated in COPD mice, evidenced by degraded IκBα and increased p-IκBα levels. si-HMGB1 significantly restrained the activation of NF-κB pathway. Briefly, miR-181a-5p targets HMGB1 to inhibit the NF-κB pathway, thus alleviating the inflammatory response in COPD mice.

Interventional effect of asiaticosdide on rats exposed to silica dust

Objective: To investigate the effect of asiaticoside for fibrosis in lung tissues of rats exposed to silica and to explore its possible mechanism. Methods: 144 SD male rats were randomly divided into control group, model group, positive drug control group, asiaticoside high-dose group, medium-dose group and low-dose group, each group included 24 rats. Rats in the control group were perfused with 1.0 ml of normal saline, and the other groups were given 1.0 ml 50 mg/ml SiO(2) suspension. Gavage of herbal was given from the next day after model establishment, once a day. Rats in the positive drug control group were administration with 30 mg/kg tetrandrine and rats in the low-dose group, medium-dose group and high-dose group were given 20 mg/kg, 40 mg/kg and 60 mg/kg asiaticoside for fibrosis respectively. Rats in the control group and the model group were given 0.9% normal saline. The rats were sacrificed in on the 14th, 28th and 56th day after intragastric administration and collect the lung tissues to detect the content of hydroxyproline, TGF-β(1) and IL-18, observe the pathological changes of the lung tissues by HE and Masson staining and determine the expressions of Col-I, a-SMA, TGF-β in lung tissues by Western Blot. Results: On the 14th day, 28th day and 56th day after model establishment, the lung tissues of rats in the model group showed obvious inflammatory response and accumulation of collagen fibers, and the degree of inflammation and fibrosis increased with time. The intervention of asiaticoside could effectively inhibit the pathological changes of lung tissues. The contents of hydroxyproline, IL-18 and TGF-β1 in lung tissues of model group were higher than those in the control group (P<0.05) , while the level of hydroxyproline, IL-18 and TGF-β1 in asiaticoside groups were significantly decreased, and the difference was statistically signicant (P<0.05) . Compared with the control group, the expression levels of Col-I, TGF-β1and α-SMA in lung tissue of model group were increased (P<0.05) , while the expression level of Col-I, TGF-β1 and α-SMA were decreased after the intervention of asiaticoside, and the difference was statistically signicant (P<0.05) . Conclusion: Asiaticoside can inhibit the increase of Col-I, TGF-β1 and α-SMA content in the SiO(2)-induced lung tissues of rats, reduce the release of TGF-β1 and IL-18 inflammatory factors in lung tissue, and then inhibit the synthesis and deposition of extracellular matrix in rat lung tissue, and improve silicosis fibrosis.

LTB4 Promotes Acute Lung Injury via Upregulating the PLCε-1/TLR4/NF-κB Pathway in One-Lung Ventilation.

Background Mechanical ventilation (MV) can provoke acute lung injury (ALI) by increasing inflammation activation and disrupting the barrier in lung tissues even causing death. However, the inflammation-related molecules and pathways in MV-induced ALI remain largely unknown. Hence, the purposes of this study are to examine the role and mechanism of a novel inflammation-related molecule, leukotriene B4 (LTB4), in ALI. Methods The functions of LTB4 in one-lung ventilation (OLV) model were detected by the loss-of-function experiments. H&E staining was used to examine the pathologic changes of lung tissues. Functionally, PLCε-1 knockdown and Toll-like receptor 4 (TLR4)/NF-κB pathway inhibitor were used to detect the regulatory effects of LTB4 on the phospholipase Cε (PLCε-1)/TLR4/nuclear factor-kappa B (NF-κB) pathway. The levels of genes and proteins were determined by RT-qPCR and western blotting assay. The levels of inflammation cytokines and chemokines were measured by ELISA. Results Here, we found LTA4H, leukotriene B (4) receptor 1 (BLT1), LTB4, and PLCε-1 upregulated in OLV rats and associated with inflammatory activation and lung permeability changes of lung tissues. Inhibition of LTB4 alleviated the OLV-induced ALI by inhibiting inflammatory activation and lung permeability changes of lung tissues. For mechanism analyses, LTB4 promoted OLV-induced ALI by activating the PLCε-1/TLR4/NF-κB pathway. Conclusion LTB4 induced ALI in OLV rats by activating the PLCε-1/TLR4/NF-κB pathway. Our findings might supply a new potential therapeutic for OLV-induced ALI.