Cell Infiltration In Lung Tissue Research Articles

Physalin B ameliorates inflammatory responses in lipopolysaccharide-induced acute lung injury mice by inhibiting NF-κB and NLRP3 via the activation of the PI3K/Akt pathway

Ethnopharmacological relevancePhysalin B (PB) is an active constituent of Physalis alkekengi L. var. Franchetii, which is a traditional medicine for clearing heat and detoxification, resolving phlegm, and diuresis. It has been commonly applied to treat sore throat, phlegm-heat, cough, dysuria, pemphigus, and eczema. Aim of studyPhysalin B has shown efficacy as an anti-acute lung injury (ALI) agent previously; however, its mechanisms of action remain unclear. In the present study, we established a lipopolysaccharide-induced septic ALI model using BALB/c mice to further confirm the therapeutic potential of PB and to assess the underlying molecular mechanisms. Materials and methodsWe used 75% ethanol and macroporous resin for extraction, separation, and enrichment of PB. The LPS-induced ALI mouse model was used to determine anti-inflammatory effects of PB. The severity of acute lung injury was evaluated by hematoxylin and eosin staining, wet/dry lung ratio, and myeloperoxidase (MPO) activity in lung tissue. An automatic analyzer was used to measure the arterial blood gas index. Protein levels of pro-inflammatory cytokines in serum, bronchoalveolar lavage fluid (BALF), and lung tissue was measured using an ELISA. Quantitative RT-PCR was used to measure changes in RNA levels of pro-inflammatory cytokines in the lungs. A fluorometric assay kit was used for determination of apoptosis-related factors to assess anti-apoptotic effects of PB. Western blotting was used to assess levels of key pathway proteins and apoptosis-related proteins. Connections between the pathways were tested through inhibitor experiments. ResultsPretreatment with PB (15 mg kg-1 d-1, i.g.) significantly reduced lung wet/dry weight ratios and MPO activity in blood and BALF of ALI mice, and it alleviated LPS-induced inflammatory cell infiltration in lung tissue. The levels of pro-inflammatory factors TNF-α, IL-6, and IL-1β and their mRNA levels in blood, BALF, and lung tissue were reduced following PB pretreatment. PB pretreatment also downregulated the apoptotic factors caspase-3, caspase-9, and apoptotic protein Bax, and it upregulated apoptotic protein Bcl-2. The NF-κB and NLRP3 pathways were inhibited through activation of the PI3K/Akt pathway due to PB pretreatment, whereas administration of PI3K inhibitors increased activation of these pathways. ConclusionsTaken together, our results suggest that the anti-ALI properties of PB are closely associated with the inactivation of NF-κB and NLRP3 by altering the PI3K/Akt pathway. Furthermore, our findings provide a novel strategy for application of PB as a potential agent for treating patients with ALI. To the best of our knowledge, this is the first study to elucidate the underlying mechanism of action of PB against ALI.

Calycosin Alleviates Sepsis-Induced Acute Lung Injury via the Inhibition of Mitochondrial ROS-Mediated Inflammasome Activation.

Sepsis-induced acute lung injury (ALI) culminates in multiple organ failure via uncontrolled inflammatory responses and requires effective treatment. Herein, we aimed to investigate the effect of calycosin (CA), a natural isoflavonoid, on sepsis-induced ALI. CA attenuated lipopolysaccharide (LPS) and cecal ligation and puncture (CLP)-induced structural damage and inflammatory cell infiltration in lung tissues by histopathological analysis. CA significantly reduced lung wet/dry ratio, inflammatory cell infiltration in bronchoalveolar lavage fluid, and myeloperoxidase activity. Moreover, CA improved the survival of septic mice. CA also substantially inhibited interleukin (IL)-1β and IL-18 levels and cleaved caspase 1 expression and activity in lung tissues. Additionally, CA markedly suppressed oxidative stress by increasing levels of superoxide dismutase and glutathione while decreasing malondialdehyde. In vitro assay showed that CA significantly inhibited LPS-induced IL-1β and IL-18 levels and cleaved caspase 1 expression and activity in BMDMs. Moreover, CA blocked the interaction among NLRP3, ASC, and caspase 1 in LPS-treated cells. CA markedly reduced mitochondrial ROS levels. Significantly, compared with CA treatment, the combination of CA and MitoTEMPO (mitochondria-targeted antioxidant) did not further reduce the IL-1β and IL-18 levels and cleaved caspase 1 expression and activity and decreased mitochondrial ROS levels. Collectively, the inhibition of mitochondrial ROS-mediated NLRP3 inflammasome activation contributes to the protective effects of CA, which may be considered a potential therapeutic agent for septic ALI.

Network pharmacology analysis and experimental validation to explore the mechanism of Hanchuan Zupa Granule in asthma

Ethnopharmacological relevanceHanchuan Zupa Granule (HCZP) is a classic prescription of Uyghur medicine, that is used for cough and abnormal mucinous asthma caused by a cold and “Nai-Zi-Lai”. Aim of the studyThis study aimed to explore the possible molecular mechanism of HCZP in the treatment of asthma, using a network pharmacology method and in vivo experiments. Materials and methodsFirst, we conducted qualitative analysis of the chemical composition of HCZP as a basis for network pharmacology analysis. Using network pharmacology tools, the possible signaling pathways of HCZP in the treatment of asthma were obtained. An OVA-sensitized asthma model was established, and HCZP was continuously administered for one week. BALF was collected for cell counting, and serum and lung tissues were collected to analyze the expression of IgE, IL-4, IL-5, IL-13 and IFN-γ. Hematoxylin & eosin (H&E) staining was performed to assess the pathological changes in the lung tissues. Related protein expression in the lung tissues was analyzed by Western blotting for molecular mechanism exploration. ResultsFifty-six chemical compounds were identified by UPLC Q-TOF MS. According to the network pharmacology results, 18 active compounds were identified among the 56 compounds, and 68 target genes of HCZP in the treatment of asthma were obtained. A total of 19 pathways were responsible for asthma (P < 0.05) according to KEGG pathway analysis. In vivo results showed that OVA sensitivity induced increased respiratory system resistance and inflammatory responses, which included inflammatory cell infiltration and high levels of IgE, IL-4, IL-5 and IL-13 in serum and lung tissues. Furthermore, OVA upregulated p-PI3K, p-JNK and p-p38 expression in lung tissues. Moreover, HCZP treatment significantly downregulated respiratory system resistance, and the expression of IL-4, IL-5, IL-13 and IgE, as well as significantly improved inflammatory cell infiltration in lung tissues. Moreover, the protein expression of p-PI3K, p-JNK and p-p38 in lung tissues decreased after HCZP treatment. ConclusionHCZP significantly inhibited the OVA-induced inflammatory response via the PI3K-Akt and Fc epsilon RI signaling pathways.

Dexmedetomidine alleviates pulmonary edema through the epithelial sodium channel (ENaC) via the PI3K/Akt/Nedd4-2 pathway in LPS-induced acute lung injury

Dexmedetomidine (Dex), a highly selective α2-adrenergic receptor (α2AR) agonist, has an anti-inflammatory property and can alleviate pulmonary edema in lipopolysaccharide (LPS)-induced acute lung injury (ALI), but the mechanism is still unclear. In this study, we attempted to investigate the effect of Dex on alveolar epithelial sodium channel (ENaC) in the modulation of alveolar fluid clearance (AFC) and the underlying mechanism. Lipopolysaccharide (LPS) was used to induce acute lung injury (ALI) in rats and alveolar epithelial cell injury in A549 cells. In vivo, Dex markedly reduced pulmonary edema induced by LPS through promoting AFC, prevented LPS-induced downregulation of α-, β-, and γ-ENaC expression, attenuated inflammatory cell infiltration in lung tissue, reduced the concentrations of TNF-α, IL-1β, and IL-6, and increased concentrations of IL-10 in bronchoalveolar lavage fluid (BALF). In A549 cells stimulated with LPS, Dex attenuated LPS-mediated cell injury and the downregulation of α-, β-, and γ-ENaC expression. However, all of these effects were blocked by the PI3K inhibitor LY294002, suggesting that the protective role of Dex is PI3K-dependent. Additionally, Dex increased the expression of phosphorylated Akt and reduced the expression of Nedd4-2, while LY294002 reversed the effect of Dex in vivo and in vitro. Furthermore, insulin-like growth factor (IGF)-1, a PI3K agonists, promoted the expression of phosphorylated Akt and reduced the expression of Nedd4-2 in LPS-stimulated A549 cells, indicating that Dex worked through PI3K, and Akt and Nedd4-2 are downstream of PI3K. In conclusion, Dex alleviates pulmonary edema by suppressing inflammatory response in LPS-induced ALI, and the mechanism is partly related to the upregulation of ENaC expression via the PI3K/Akt/Nedd4-2 signaling pathway.

Alveolar Epithelial Cells Promote IGF-1 Production by Alveolar Macrophages Through TGF-β to Suppress Endogenous Inflammatory Signals.

To maintain alveolar gas exchange, the alveolar surface has to limit unnecessary inflammatory responses. This involves crosstalk between alveolar epithelial cells (AECs) and alveolar macrophages (AMs) in response to damaging factors. We recently showed that insulin-like growth factor (IGF)-1 regulates the phagocytosis of AECs. AMs secrete IGF-1 into the bronchoalveolar lavage fluid (BALF) in response to inflammatory stimuli. However, whether AECs regulate the production of IGF-1 by AMs in response to inflammatory signals remains unclear, as well as the role of IGF-1 in controlling the alveolar balance in the crosstalk between AMs and AECs under inflammatory conditions. In this study, we demonstrated that IGF-1 was upregulated in BALF and lung tissues of acute lung injury (ALI) mice, and that the increased IGF-1 was mainly derived from AMs. In vitro experiments showed that the production and secretion of IGF-1 by AMs as well as the expression of TGF-β were increased in LPS-stimulated AEC-conditioned medium (AEC-CM). Pharmacological blocking of TGF-β in AECs and addition of TGF-β neutralizing antibody to AEC-CM suggested that this AEC-derived cytokine mediates the increased production and secretion of IGF-1 from AMs. Blocking TGF-β synthesis or treatment with TGF-β neutralizing antibody attenuated the increase of IGF-1 in BALF in ALI mice. TGF-β induced the production of IGF-1 by AMs through the PI3K/Akt signaling pathway. IGF-1 prevented LPS-induced p38 MAPK activation and the expression of the inflammatory factors MCP-1, TNF-α, and IL-1β in AECs. However, IGF-1 upregulated PPARγ to increase the phagocytosis of apoptotic cells by AECs. Intratracheal instillation of IGF-1 decreased the number of polymorphonuclear neutrophils in BALF of ALI model mice, reduced alveolar congestion and edema, and suppressed inflammatory cell infiltration in lung tissues. These results elucidated a mechanism by which AECs used TGF-β to regulate IGF-1 production from AMs to attenuate endogenous inflammatory signals during alveolar inflammation.

Bifidobacterium infantis Relieves Allergic Asthma in Mice by Regulating Th1/Th2.

BackgroundBifidobacteria are among the probiotics used in treating intestinal diseases and are rarely used for allergic asthma treatment. The present study investigated the mechanism of B. infantis in treating allergic asthma in mice.Material/MethodsA total of 40 male Balb/c mice were randomized into control, ovalbumin (OVA), montelukast (Mon), and B. infantis (B10) groups, and allergic asthma was induced in the OVA, Mon, and B10 groups. Airway reactivity was measured on day 29 by methacholine at various doses. The numbers of total cells and inflammatory cells in bronchoalveolar lavage fluid (BALF) were counted by blood cell counter and Diff-Quik staining. Hematoxylin-eosin (HE) staining was performed to observe inflammatory cell infiltration in lung tissues. Total IgE and OVA-specific IgE in serum were measured by ELISA. Mucin 5AC expression was detected by Western blot to evaluate airway obstruction. The levels of Th1 (IFN-γ, IL-2) and Th2 (IL-4, IL-5, IL-13) cytokines in BALF and tissues were detected by ELISA and qRT-PCR, respectively.ResultsThe mice in the OVA group had airway hyperreactivity, while the symptoms in the B10 group and Mon group were effectively relieved. B10 reduced the number of inflammatory cells in BALF as well as inflammatory cell infiltration in tissues. Moreover, the levels of total serum IgE, OVA-specific IgE, and Mucin 5AC were increased in the OVA group, but were reduced in the Mon group and B10 group. B. infantis increased the levels of Th1 cytokines and decreased those of Th2 cytokines.ConclusionsB. infantis can reduce the infiltration of inflammatory cells induced by OVA-specific antibodies in mice. B. infantis has therapeutic effects on allergic asthma by promoting Th1 and inhibiting Th2 immune responses.

Mangiferin alleviates arsenic induced oxidative lung injury via upregulation of the Nrf2-HO1 axis

Arsenic contaminated drinking water consumption is a serious health issue around the world. Chronic inorganic arsenic exposure has been associated with respiratory dysfunctions. It exerts various detrimental effects, disrupting normal cellular homeostasis and turning on severe pulmonary complications. This study elucidated the role of mangiferin, a natural xanthone, against arsenic induced lung toxicity. Chronic exposure of sodium arsenite (NaAsO2) at 10 mg/kg bw for 3 months abruptly increased the LDH release in broncho-alveolar lavage fluid, generated reactive oxygen species (ROS), impaired the antioxidant defense and distorted the alveoli architecture. It caused significant inflammatory outburst and promoted the apoptotic mode of cell death via upregulating the expressions of various proapoptotic molecules related to mitochondrial, extra-mitochondrial and ER stress mediated apoptotic pathway. Activation of inflammatory cascade led to disruption of alveolar capillary barrier and impaired Na+/K+-ATPase function that led to detaining of alveolar fluid clearance activity. Mangiferin due to its anti-inflammatory activity suppressed this inflammation and reduced inflammatory cell infiltration in lung tissue. It significantly restored the antioxidant balance and inhibited apoptosis in lung via upregulating Nrf2-HO1 axis.

Umbelliferone Alleviates Lipopolysaccharide-Induced Inflammatory Responses in Acute Lung Injury by Down-Regulating TLR4/MyD88/NF-κB Signaling.

This study investigated the protective effect and underlying mechanism of action of umbelliferone (Umb) against lipopolysaccharide (LPS)-induced acute lung injury (ALI). An intragastric Umb injection prior to the administration of LPS dramatically decreased the wet/dry lung weight ratio, attenuated inflammatory cell infiltration in lung tissue, and reduced the LPS-induced production of inflammatory cytokines, including monocyte chemotactic protein-1(MCP-1), interleukin (IL)-6, tumor necrosis factor-α (TNF-α), and IL-1β, in broncheoalveolar lavage fluid(BALF). In addition, Umb resulted in significant anti-oxidative effects as shown by decreased myeloperoxidase (MPO) and malondialdehyde (MDA) activity and increased superoxide dismutase (SOD) activity compared with the LPS group. Finally, the inhibitory effects of Umb on the expression of toll-like receptor 4 (TLR4)/myeloid differentiation protein 88 (MyD88)/nuclear factor-κB (NF-κB) signaling pathway proteins were also measured. Our results clearly indicated that Umb exerted significant protective effects on LPS-induced ALI by inhibiting the activation of the TLR4/MyD88/NF-κB pathway.

Roles of citric acid in conjunction with saline nebulization in experimental tracheostomy in guinea pigs

Purpose: Tracheostomy usually accompanied by the impairment of cough reflex, which may affect the clearance of secretions and result in the occurrence and development of pulmonary inflammation. Previous research has demonstrated that citric acid could effectively evoke cough. However, there are limited data available on this topic specific to the cough stimulation method, and the roles of citric acid in tracheostomy still remain obscure. The aims of present study were to identify the potential roles of citric acid in conjunction with saline nebulization in tracheostomy in guinea pigs. Materials and Methods: Experimental tracheostomy model was induced in guinea pigs, and different nebulization interventions were implemented. The expression of P-selectin and platelet count were analyzed by flow cytometer and automatic globulimeter, the histological changes in trachea and lung tissue were assessed by hematoxylin and eosin staining, and the inflammatory cytokines and substance P (SP) levels in bronchoalveolar lavage fluid were evaluated by enzyme-linked immunosorbent assay. Results: Tracheostomy resulted in the disorder of trachea mucosa and cilia, the inflammatory cell infiltration in lung tissue, the increase of IL-6, TNF-α levels and the decrease of SP level. Citric acid alone increase the SP level, and the joint action of citric acid and saline nebulization further showed significantly beneficial effects on pathological, inflammatory changes and SP level.Conclusions: Citric acid combined with saline nebulization contributes to the alleviation of tracheotomy-induced tracheal damage and pulmonary inflammation in an experimental tracheostomy model in guinea pigs. This may provide novel insights into the inflammation management and cough recovery after tracheostomy.

Delayed oseltamivir plus sirolimus treatment attenuates H1N1 virus-induced severe lung injury correlated with repressed NLRP3 inflammasome activation and inflammatory cell infiltration

Severe influenza A virus infection causes high mortality and morbidity worldwide due to delayed antiviral treatment and inducing overwhelming immune responses, which contribute to immunopathological lung injury. Sirolimus, an inhibitor of mammalian target of rapamycin (mTOR), was effective in improving clinical outcomes in patients with severe H1N1 infection; however, the mechanisms by which it attenuates acute lung injury have not been elucidated. Here, delayed oseltamivir treatment was used to mimic clinical settings on lethal influenza A (H1N1) pdm09 virus (pH1N1) infection mice model. We revealed that delayed oseltamivir plus sirolimus treatment protects mice against lethal pH1N1 infection by attenuating severe lung damage. Mechanistically, the combined treatment reduced viral titer and pH1N1-induced mTOR activation. Subsequently, it suppressed the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome-mediated secretion of interleukin (IL)-1β and IL-18. It was noted that decreased NLRP3 inflammasome activation was associated with inhibited nuclear factor (NF)-κB activation, reduced reactive oxygen species production and increased autophagy. Additionally, the combined treatment reduced the expression of other proinflammatory cytokines and chemokines, and decreased inflammatory cell infiltration in lung tissue and bronchioalveolar lavage fluid. Consistently, it inhibited the mTOR-NF-κB-NLRP3 inflammasome-IL-1β axis in a lung epithelial cell line. These results demonstrated that combined treatment with sirolimus and oseltamivir attenuates pH1N1-induced severe lung injury, which is correlated with suppressed mTOR-NLRP3-IL-1β axis and reduced viral titer. Therefore, treatment with sirolimus as an adjuvant along with oseltamivir may be a promising immunomodulatory strategy for managing severe influenza.

The effects of methylprednisolone on NLRP3 inflammasome in rats with acute lung injury Induced by Phosgene

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

Development of a hollow mesoporous silica nanoparticles vaccine to protect against house dust mite induced allergic inflammation

Allergen specific immunotherapy (SIT) is the only specific therapeutic way for house dust mite (HDM) allergy. To improve the efficacy of SIT, hollow mesoporous silica nanoparticles (HMSNs) were used as vehicles for HDM allergen. The HMSNs were prepared and characterized. The major HDM allergen (Der f2) was loaded onto HMSNs, and the drug loading capacity and release profile were determined. Then the Der f2 loaded HMSNs were injected subcutaneously to mouse model of Der f2 induced allergic asthma and the preventive effects were evaluated. Our results showed that HMSNs were spherical (100 nm) with pore diameter of 2.897 nm and successfully loaded with Der f2 protein. The loading capacity is 90 μg Der f2/1 mg HMSNs. The Der f2 loaded on HMSNs released slowly in 72 h. Treatment with Der f2 loaded HMSNs could efficiently decrease Der f2 specific IgE levels, inflammatory cells infiltration in lung tissue, and Th2 cytokine IL4 levels in BALF. In the meanwhile, it could increase the Der f2 specific IgG levels, Th1 cytokine IFN-γ levels, and induce proliferation of splenocytes to Der f2 accompanied by increased IFN-γ levels. These results showed that Der f2 loaded HMSNs were efficient in preventing allergic inflammation, and HMSNs may be potential vehicles for SIT of HDM allergy.

Mechanism of lung injury of rats induced by inhalation of white smoke from burning smoke pot

Objective: To explore mechanism of lung injury of rats induced by inhalation of white smoke from burning smoke pot. Methods: Forty-eight Sprague Dawley rats were divided into control group (n=12) and injury group (n=36) according to the random number table. Rats in injury group were placed in smoke-induced injury experimental equipment fulled with white smoke from burning smoke pot for 5 minutes to make lung injury, and rats in control group were placed in smoke-induced injury experimental equipment fulled with air for 5 minutes to make sham injury. Six rats in injury group at post injury hour (PIH) 6, 24, and 72 and six rats in control group at PIH 72 were collected to observe pathological changes of lung tissue and pathological score of rats in the two groups by hematoxylin-eosin staining, to detect expression of nuclear factor-κB (NF-κB) p65 mRNA in lung tissue of rats by reverse transcriptional polymerase chain reaction, and to detect content of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and IL-6 in lung tissue of rats by enzyme-linked immunosorbent assay. Data were processed with one-way analysis of variance and t test. Results: At PIH 72, lung tissue structure of rats in control group was clear and complete, with no inflammatory cell infiltration. At PIH 6, there was edema, hemorrhage, and inflammatory cell infiltration in lung tissue of rats in injury group. At PIH 24, edema, hemorrhage, and inflammatory cell infiltration in lung tissue of rats in injury group aggravated. At PIH 72, area of edema in lung tissue of rats in injury group was enlarged, with obvious hemorrhage and inflammatory cell infiltration. At PIH 6, 24, and 72, pathological score of lung tissue of rats in injury group was (3.43±0.86), (5.39±0.93), and (9.99±0.84) points, respectively, obviously higher than that of rats in control group at PIH 72 [(2.11±0.20) points, t=3.659, 8.450, 22.355, P<0.05]. As time post injury prolonged, pathological scores of lung tissue of rats in injury group were significantly increased (F=121.244, P<0.01). At PIH 6, 24, and 72, expression of NF-κB p65 mRNA in lung tissue of rats in injury group was 15.5±4.3, 25.9±1.8, 30.9±3.5 respectively, significantly higher than that of rats in control group at PIH 72 (7.8±0.8, t=4.315, 20.445, 14.408, P<0.01). As time post injury prolonged, expression of NF-κB p65 mRNA in lung tissue of rats in injury group gradually increased (F=32.691, P<0.01). At PIH 6, 24, and 72, content of TNF-α, IL-1β, and IL-6 in lung tissue of rats in injury group was significantly higher than that of rats in control group at PIH 72, respectively (t=7.650, 8.968, 6.827, 6.726, 8.978, 3.460, 5.420, 13.289, 16.438, P<0.01). At PIH 24, content of TNF-α and IL-1β in lung tissue of rats in injury group was higher than that of rats in the same group at PIH 6 and 72, respectively (t=3.409, -2.549, 4.047, -4.100, P<0.05). At PIH 24 and 72, content of IL-6 in lung tissue of rats in injury group was respectively higher than that of rats in the same group at PIH 6 (t=8.273, 9.711, P<0.05). Conclusions: After inhaling white smoke from burning smoke pot, rats are inflicted with lung injury by increasing expression of NF-κB p65 mRNA and content of TNF-α, IL-1β, and IL-6, and induce pathological changes of edema, hemorrhage, and inflammatory cell infiltration of lung tissue.

Silica nanoparticle exposure during the neonatal period impairs hippocampal precursor proliferation and social behavior later in life.

IntroductionSilica nanoparticles (SiO2-NPs) are currently among the most widely used nanomaterials, but their potentially adverse effects on brain development remain unknown. The developing brain is extremely sensitive to NP neurotoxicity during the early postnatal period.Materials and methodsHerein, we investigated the effects of SiO2-NPs (doses of 10, 20, or 50 mg with a particle size of ~91 nm, equivalent to aerosol mass concentrations 55.56, 111.11, and 277.78 mg/m3, respectively) exposure from postnatal day (P) 1 to P7 on hippocampal precursor proliferation at P8 and long-term neurobehavior in adults.ResultsSiO2-NP exposure resulted in inflammatory cell infiltration in lung tissue, microglia over-activation in the hippocampal dentate gyrus (DG), and decreased hippocampal precursor proliferation in the DG-subgranular zone at P8. Moreover, after exposure to 20 mg of SiO2-NPs, mice exhibited social interaction deficits and slight anxiety-like behaviors in adulthood, but this exposure did not induce locomotor activity impairment, depression-like behavior, or short-term memory impairment.DiscussionThese findings suggest that early-age SiO2-NP exposure induced inflammation and inhibited precursor proliferation in the DG in a dose-dependent manner, which might be related to the social dysfunction observed in adulthood.

Comparison of lung protection for hydrochloric acid or oleic acid induced rat acute respiratory distress syndrome models pretreated with penehyclidine

To compare the lung protection roles of intraperitoneal pre-injection with penehyclidine for two kinds of rat models with pulmonary and extrapulmonary acute respiratory distress syndrome (ARDSp and ARDSexp). Forty healthy adult Sprague-Dawley (SD) rats were randomly divided into five groups (each n = 8): the rats in sham group received only tracheotomy; the ARDS rat models were reproduced by intratracheal inhalation of 0.1 mol/L hydrochloric acid (HCl) 2 mL/kg to simulate ARDSexp (HCl group) and 0.15 mL/kg oleic acid (OA) intravenous injection to simulate ARDSp (OA group) after tracheotomy; and the rats in two intervention groups were intraperitoneal injected with penehyclidine 0.5 mg/kg. All rats were received mechanical ventilation immediately after model reproduction. Carotid arterial blood was collected 4 hours after model reproduction for determining the arterial partial pressure of oxygen (PaO2), and oxygenation index (PaO2/FiO2) was calculated. Carotid venous blood and lung tissues were harvested, and the levels of myeloperoxidase (MPO), interleukin-8 (IL-8) and nuclear factor-κB (NF-κB) in serum and lung tissue were determined by enzyme linked immunosorbent assay (ELISA). Pulmonary pathology was observed under optical microscope, and pathological score of Smith was calculated. Under optical microscope, a large number of inflammatory cells infiltration in lung tissue, obvious alveolar collapse, fibrous exudation in alveolar and alveolar hyaline were found in HCl group. In OA group, however, microvascular congestion and interstitial pulmonary edema were the main pathological changes, with alveolar structure being kept relatively intact. Compared with sham group, pathological score of Smith in HCl and OA groups were increased, oxygenation was lowered, and inflammatory factors levels in serum and lung tissue were increased with levels in lung tissue being higher than those in serum, without significant difference between the two models. When pretreated with penehyclidine, however, pathological injury induced by HCl or OA was alleviated, and pathological score of Smith was also decreased as compared with that of corresponding model groups (5.48±1.76 vs. 9.69±2.02, 3.97±2.14 vs. 8.71±2.18, both P < 0.05), PaO2/FiO2 was raised significantly [mmHg (1 mmHg = 0.133 kPa): 323±55 vs. 211±27, 307±56 vs. 207±31, both P < 0.05], the inflammatory factors levels in serum and lung tissue were obviously decreased [MPO (μg/L): 11.91±1.55 vs. 14.82±1.25, 12.75±1.16 vs. 16.97±2.06 in serum, 25.80±3.36 vs. 35.18±4.01, 24.23±1.24 vs. 33.94±1.43 in lung tissue; IL-8 (ng/L): 358±30 vs. 459±25, 377±38 vs. 427±34 in serum, 736±53 vs. 866±51, 701±53 vs. 809±39 in lung tissue; NF-κB (ng/L): 483±68 vs. 632±73, 514±83 vs. 685±78 in serum, 984±75 vs. 1 217±123, 944±90 vs. 1 163±105 in lung tissue; all P < 0.05]. But all parameters above were similar between the two pretreatment groups (all P > 0.05). Inflammatory cell infiltration and alveolar collapse mainly happened in HCl induced ARDSp, while pulmonary interstitial edema and hemorrhage was mostly seen in ARDSexp rats induced by OA intravenous injection. There was no significant difference in oxygenation and inflammatory response between the two models of rats. Pre-intraperitoneal injection of penehyclidine equally improved oxygenation state, inhibited lung inflammation response, and reduced lung injury in the two kinds of ARDS, but there was no difference in protective role between two models pretreated with penehyclidine.

Establishment of a mouse model of pneumonia with an isolated epidemic ST23 Klebsiella pneumonia strain

Objective To establish a mouse model of pneumonia with C57BL/6 and MyD88KO mice after infection with an isolated ST23 Klebsiella pneumonia (KP) strain, which was an epidemic strain and identified by multilocus sequence typing (MLST). Methods Fifty C57BL/6 mice were randomly divided into three groups: KP infection, control and immunosuppressive groups. Thirty MyD88KO mice were divided into KP infection and control groups. All mice in the KP infection groups were infected with 50 μl of ST23 KP strain through nasal dripping. Equal volume of PBS was used to set up the control groups. Mice in the immunosuppressive group were first injected with cyclophosphamide for three days and then infected with equal volume of ST23 KP strains through nasal dripping. Clinical signs and survival curves during KP infection were monitored. Moreover, pulmonary bacterial loads and histopathological changes in the KP-infected mice were detected at different time points. Results ST23 KP-infected C57BL/6 mice showed inflammatory cell infiltration in lung tissues on the 10th day and remained alive on the 21st day. All ST23 KP-infected MyD88KO mice died on the 5th day with severe histopathological damage in lung tissues. C57BL/6 mice that pretreated with cyclophosphamide had similar symptoms with MyD88KO mice after infection and died on the 5th day. Some critical inflammatory mediators such as TNF-a, nitric oxide synthase 1 (NOS1) and NF-κBp65 were up-regulated in lung tissues of mice after KP infection. No inflammatory syndromes were found in the mice of PBS control groups. Conclusion This study suggests that the mouse model of pneumonia is successfully established with KP strain. It will help researchers to study the characteristics and pathogenesis of ST23 KP strain-induced pneumonia and to seek safe treatments in the future. Key words: Klebsiella pneumonia (KP); ST23; TNF-α; NF-κBp65

HSP27 inhibitor attenuates radiation-induced pulmonary inflammation

Radiation therapy has been used to treat over 70% of thoracic cancer; however, the method usually causes radiation pneumonitis. In the current study, we investigated the radioprotective effects of HSP27 inhibitor (J2) on radiation-induced lung inflammation in comparison to amifostine. In gross and histological findings, J2 treatment significantly inhibited immune cell infiltration in lung tissue, revealing anti-inflammatory potential of J2. Normal lung volume, evaluated by micro-CT analysis, in J2-treated mice was higher compared to that in irradiated mice. J2-treated mice reversed radiation-induced respiratory distress. However, amifostine did not show significant radioprotective effects in comparison to that of J2. In HSP27 transgenic mice, we observed increased immune cells recruitment and decreased volume of normal lung compared to wild type mice. Increased ROS production and oxidative stress after IR were down-regulated by J2 treatment, demonstrating antioxidant property of J2. The entire data of this study collectively showed that J2 may be an effective therapeutic agent for radiation-induced lung injury.

Significance of the NLRP3 inflammasome expression in rats with acute lung injury induced by phosgene

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

Angiogenesis correlates with macrophage and mast cell infiltration in lung tissue of animals exposed to fluoro-edenite fibers

Angiogenesis plays a crucial role in progression of pleural malignant mesothelioma. A significantly increased incidence of pleural mesothelioma has been attributed to exposure to fluoro-edenite, a fibrous amphibole extracted from a local stone quarry. In this study, we have investigated the expression of CD68-positive macrophages, tryptase-positive mast cells and CD31 positive areas, as expression of microvascular density, in lung tissue of sheeps exposed to fluoro-edenite fibers vs controls, by immunohistochemical, morphometric and Western blot analysis. The result have evidenced a significant increase in the expression of CD68-positive macrophages, tryptase-positive mast cells as well as a significant increase in microvascular density evaluated as CD31 positive areas in lung tissue of of sheeps exposed to fluoro-edenite fibers vs controls. These data confirmed the important role played by tumor microenvironment components, including macrophages and mast cells, in favour of angiogenesis in pleural mesothelioma induced by fluoro-edenite exposure.

The roles and mechanisms of p-STAT3 signaling pathway in acute pancreatitis

To detect the expression ofsignal transducer and activator of transcription 3 (STAT3) in pancreatic tissue of the mouse model of pancreatitis, and to explore its role in the evolution of acute pancreatitis. Forty-eight healthy male balb/c mice were randomly divided into 3 groups (n=16):control group (Con) 0.09% NaCl, intraperitoneal injection; mild acute pancreatitis group (MAP) caerulein, intraperitoneal injection; severe acute pancreatitis group (SAP) caerulein plus lipopolysaccharide(LPS), intraperitoneal injection. The mice were sacrificed after 2 h and 6 h after intraperitoneall injection. Serum was isolated for amylase activity. Pancreatic was isolated and weighedto calculate the pancreatic wet weight ratio. Myeloperoxidase (MPO) activity was measured to assess the degree of inflammatory cell infiltration in lung tissue. Using HE staining, the pathological changes of pancreatic and lung were observed under the light microscope. The expression of phosphorylated STAT3 (p-STAT3) was detected by Western blot. Compared with control group, serum amylase activity, pancreatic wet weight ratio and lung MPO activity were significantlyincreased (P<0.05) in MAP and SAP group at each time point, especially SAP group showed higher levels of MPO activity than that in MAP group (P<0.01). The pathological changes of pancreas and lung were observed after modeling in 2 h. Western blot showed the expression of p-STAT3 could be detected in SAP group, the level increased most significantly after modeling 2 h, and decreased slightly after 6 h. The level of p-STAT3 was low in MAP group and negative in Con group at each time point. The expression of p-STAT3 in MAP and SAP groups are significantly different from that in control group, which indicates that STAT3 isclosely related in acute pancreatitis. Inhibition of STAT3 activity is a potential target to alleviate acute pancreatitis progression.