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Objective:To explore the protective effect of Lindera aggregata on acute respiratory distress syndrome (ARDS) induced by lipopolysaccharide (LPS) in mice and its possible mechanism.Methods:Forty C57BL/6 mice were randomly divided into sham operation group, ARDS model group, low-dose Lindera aggregata (L-LA) group and high-dose Lindera aggregata (H-LA) group, with 10 mice in each group. ARDS model was established by injecting 5 mg/kg LPS through the trachea. The L-LA group and H-LA group were orally administrated 1 g/kg and 5 g/kg of the Lindera aggregate extract once a day, respectively, while the ARDS model group was given the same volume of normal saline, the sham group received no treatment. The Lindera aggregata was preadministered for 3 days before modeling, and continued for 2 days after modeling, then the animals were sacrificed, and bronchoalveolar lavage fluid (BALF) and lung tissue were collected. The pathological changes of lung tissue in each group of mice were observed under the microscope and the wet/dry weight ratio (W/D) of the lung were measured. Enzyme linked immunosorbent assay (ELISA) was used to examine the levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in mice serum and BALF, and flow cytometry was used to detect the expression rate of CD40 on the surface of BALF macrophages. The phosphorylation levels of p38 and extracellular signal-regulated protein kinase 1/2 (ERK1/2) proteins in lung tissue were measured by Western blotting.Results:Lung histopathology under light microscope showed that the damage of alveolar structure, thickening of alveolar septum and infiltration of inflammatory cells in the H-LA group were less severe than those in the ARDS model group, while the pathological characteristics of ARDS in the L-LA group were not significantly different from those in the ARDS model group. Compared with the sham operation group, the lung W/D ratio, TNF-α and IL-6 protein contents in serum and BALF, BALF macrophage CD40 expression rate and lung tissue p38 and ERK1/2 protein phosphorylation levels were significantly increased in ARDS model group. The W/D ratio, the concentrations of TNF-α and IL-6 in serum and BALF, the expression rate of CD40 in BALF macrophages, and the phosphorylation levels of p38 and ERK1/2 protein in lung tissue in the L-LA group were not significantly different from those in the ARDS model group. The above indexes in the H-LA group were significantly lower than those in the ARDS model group and the L-LA group [W/D ratio: 5.70±0.19 vs. 6.20±0.31, 6.01±0.17; serum TNF-α (ng/L): 83.63±15.04 vs. 111.75±18.45, 108.12±13.98; serum IL-6 (ng/L): 111.38±8.75 vs. 244.13±26.85, 227.50±9.37; BALF TNF-α (ng/L): 36.25±2.82 vs. 51.13±5.44, 47.50±5.78; BALF IL-6 (ng/L): 35.63±2.20 vs. 49.63±4.90, 46.38±3.50; CD40 expression rate (%): 23.28±2.45 vs. 30.32±2.40, 28.17±1.98; p-p38/p38: 0.50±0.04 vs. 0.74±0.07, 0.69±0.04; p-ERK1/2/ERK1/2: 0.47±0.07 vs. 0.72±0.07, 0.68±0.05; all P < 0.01]. Conclusions:Lindera aggregata can inhibit LPS-induced lung inflammation and alleviate lung injury in ARDS mice. The mechanism may be related to the inhibition of the activation of p38 mitogen activated protein kinase/ERK (p38MAPK/ERK) signaling pathway.
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Inflammatory bowel disease (IBD) is a chronic and recurrent disease characterized by chronic inflammation of the gastrointestinal tract. The quality of life of patients with IBD is seriously affected. The pathogenesis of IBD is complex, among which immune factors are considered to be the predominant factor. Leptin is a hormone derived from adipocytes and recent studies have shown that it is involved in the regulation of immune cells and inflammatory signaling pathways. This review summarized the pathogenesis of IBD, the immunoregulatory mechanism of leptin and research progress in immune modulators, introduced the potential effects of leptin on the regulation of immunological homeostasis in IBD and its potential roles in the etiology and pathogenesis of IBD, and discussed a possible immunotherapy method to treat IBD through leptin antagonist to reduce the inflammatory response and inhibit the inflammatory signaling pathways.
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Colorectal cancer is a common malignant tumor of digestive tract, and the risk of inflammatory bowel disease developing into colorectal cancer is significantly increased. Immune signaling pathways NF-κB, IL-6/STAT3, COX-2/PGE2, IL-23/Th17 and TLRs have been confirmed to promote the transformation from colitis to colorectal cancer. NOD2 and intestinal microbes also participate in the regulation of inflammation mediated carcinogenesis. Chronic inflammation is a potential risk for colorectal cancer, and anti-inflammatory drugs may play a chemical preventive role. In this review, we summarize the signaling pathways involved in inflammation-associated colon carcinogenesis and evaluate the chemoprophylaxis of colon cancer.
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Objective@#To investigate the effect of bilirubin on inflammatory signaling pathway mediated by NOD-like receptor 2(NOD2) in premature infants.@*Methods@#Fifteen cases of premature infants hospitalized at the Department of Neonatology, Children′s Hospital of Soochow University from April 2016 to January 2017, were selected, and 2 mL peripheral blood were collected from 15 cases of premature infants, and the mononuclear cells were isolated and divided into 6 groups, including blank control group (group A), muramyl dipeptide(MDP) group (group B), 102 μmol/L bilirubin group(group C), 102 μmol/L bilirubin+ MDP group (group D), 153 μmol/L bilirubin+ MDP group (group E), 255 μmol/L bilirubin+ MDP group (group F). Group A and group B were stimulated by buffer, group C, group D, group E and group F were stimulated by 102 μmol/L, 102 μmol/L, 153 μmol/L, 255 μmol/L bilirubin, respectively.The supernatant was discarded after 1 h, then the medium was added to group A and group C, and the rest of the 4 groups were agonisted with MDP, the cells were stimulated for 24 h, and then the cells and supernatant fluids were collected respectively, the expression levels of NOD2 mRNA in the cells were determinated by real time-PCR, and the expression levels interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) in the supernatant was determinated by enzyme linked immunosorbent assay.@*Results@#The expression levels of NOD2 mRNA had no obvious changes after being stimulated by MDP or by different concentrations of bilirubin(7.16±3.08, 6.19±1.99, 7.02±4.04, 6.84±1.81) compared to those of the blank control group(7.46±3.70)(all P>0.05). After being stimulated by MDP, the expression level of IL-6 (5.13±2.36)was significantly higher than that of the blank control group(3.84±1.44), and the difference was statistically significant(P<0.05), but TNF-α had no obvious changes(4.85±2.47 vs.4.04±2.26, P>0.05). The expression levels of IL-6 and TNF-α had no obvious changes compared to those of the blank control group after being stimulated by 102 μmol/L bilirubin(3.26±1.06 vs.3.84±1.44, 3.45±1.84 vs.4.04±2.26, all P>0.05); but the expression levels of IL-6 and TNF-α were significantly lower after 153 μmol/L and 255 μmol/L bilirubin stimulation (IL-6: 2.58±1.33, 2.16±0.94; TNF-α: 2.32±1.49, 2.42±1.42)compared to those of the blank control group(3.84±1.44, 4.04±2.26), and the differences were statistically significant(all P<0.05).@*Conclusions@#Bilirubin have no obvious inhibitory effect on NOD2, and low concentration of bilirubin had no obvious inhibitory effect on IL-6 or TNF-α in this study, but high concentration of bilirubin can inhibit the expression levels of IL-6 and TNF-α, hyperbilirubin may inhibit the ability of anti-infection immune response in body by inhibiting inflammatory signaling pathway mediated by NOD2.
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Objective·To establish a reliable alcoholic liver disease mouse model (ALDNM) that mimics the drinking pattern of alcoholic liver disease (ALD) patients.Methods·Using the self-designed feeding tubes and liquid diet,ALDNM model was developed through chronic feeding combined with acute gavage of ethanol based on Lieber-DeCarli model and Gao-Binge model.C57BL/6 mice were administered with control liquid diet for adaptation for first 5 d,and then divided into pair-fed group and ethanol-fed group (10 mice each group).Ethanol-fed mice were fed with the liquid diet in which ethanol accounts for 30％ of total energy,while the pair-fed mice were fed with the control diet for 10 d.At the 16th day,ethanol-fed mice and pair-fed mice were respectively gavaged a single dose of 31.5％ ethanol or isocaloric maltose dextrin,and euthanized 9 h later.Sera and livers were collected.The general physiological condition,hepatic tissue pathological changes and serum indexes between Lieber-DeCarli models and ALDNM models were compared.The liver lipids of ALDNM mice were determined by Oil red O (ORO) staining and hepatic triacylglyceride (TAG) test.Meanwhile,the mRNA levels of interleukin-6 (IL-6),tumor necrosis factor α (TNF-α),fatty acid synthase (Fas),long chain fatty acid elongase 6 (Elovl6) and stearyl-CoA desaturase (Scdl) were detected by real-time PCR in ALDNM models.Western blotting was used to detect the changes of phosphorylated signal transduction and transcriptional activator (p-STAT3) in the livers.Results·Lieber-DeCarli model mice were generally in poor condition,and there was no significant change in serum glutamic-pyruvic transaminase (GPT) and glutamic-oxaloacetic transaminase (GOT) compared to pair-fed group.However,in ALDNM models,H-E staining showed that the hepatocytes of ethanol-fed mice were extremely swollen with round volume,increased cytoplasm and filled with large amounts of fat vacuoles.ORO staining analyses showed obvious microsteatosis in the liver cells from all ethanol-fed mice.The hepatosomatic index,liver TAG content,serum GPT and GOT of ALDNM models were significantly higher than those in the pair-fed group,while the serum HDL significantly decreased compared to the pair-fed group.Moreover,the expression levels of both lipid synthesis pathways and inflammatory signaling pathways related genes in livers significantly increased in the ethanol-fed mice of ALDNM model.Conclusion·ALDNM model was successfully constructed.This model is cost-and time-efficient.Moreover,ALDNM model mimics the drinking pattern and pathogenesis of ALD patients with the advantages of stable food intake,good repeatability,and obvious liver damage.