Study on the mechanism of PM2.5 affecting Th1/Th2 immune imbalance through the notch signaling pathway in asthmatic mice.

Some research has shown that PM2.5 causes Th1/Th2 immune imbalance and aggravates asthma. However, the exact mechanism of PM2.5 causing aggravation of asthma remains unclear. The purpose of this study was to investigate whether exposure to PM2.5 exacerbates Th1/Th2 immune imbalance through the Notch signaling pathway. Eight-week-old SPF female BALF/c mice were sensitized by ovalbumin to establish an asthma mouse model. PM2.5 exposure was carried out by aerosol inhalation of PM2.5 (510 µg/m3) after each provocation. The lung function of mice was measured and Splenic T lymphocyte subsets were detected. Notch signaling pathway was tested. The levels of interferon (IFN)-γ and interleukin (IL)-4 in serum and bronchoalveolar lavage fluid were determined. The results showed that the expression of the mRNA and protein of Notch1 and Hes1 in the asthma group were significantly higher than those in healthy controls. The levels of IL-4 were also remarkably high; while the levels of IFN-γ were remarkably low in serum and BALF, the Th1% and Th1/Th2 ratios were significantly lower, and Th2% was significantly higher in the asthma group than in the healthy controls. PM2.5 promoted further activation of the Notch signaling pathway and aggravated Th1/Th2 immune imbalance in asthmatic mice. γ-secretase inhibitor can partially inhibit the activation of the Notch signaling pathway and alleviate aggravation of immune imbalance. In conclusion, the asthmatic mice had a Th1/Th2 immune imbalance and an overactivated Notch signaling pathway. PM2.5 further aggravated Th1/Th2 immune imbalance by activating the Notch signaling pathway.

[The relationship between coagulation/anticoagulation imbalance and oxidative stress in patients with chronic obstructive pulmonary disease].

OBJECTIVE: To explore the relationship between coagulation/anticoagulation imbalance and oxidative stress in the patients with chronic obstructive pulmonary disease during acute exacerbation (AECOPD) before and after treatment. METHODS: Plasma tissue factor (TF) and tissue factor pathway inhibitor (TFPI) activity was detected by chromogenic assay in 28 AECOPD patients before and after treatment as well as in 30 healthy controls. The total antioxidative capacity (TAC), malondialdehyde (MDA) and glutathione peroxidase (GSH-PX) in plasma were measured in both groups. RESULTS: The levels of plasma TF and TFPI, and their ratio (TF/TFPI) in AECOPD patients before treatment were significantly higher than those after treatment (all P < 0.01), the latter were still higher than those in the healthy persons (all P < 0.01). The levels of the TAC and GSH-PX in plasma in AECOPD patients before treatment were significantly lower than those after treatment (all P < 0.01), the latter were still lower than those in the healthy persons (all P < 0.01). The plasma MDA in AECOPD patients before treatment was significantly higher than that after treatment (P < 0.01), which was still higher than that in the healthy persons (P < 0.05). There were negative correlations between TF/TFPI ratio and TAC (r = -0.518, P < 0.01), GSH-PX (r = -0.454, P < 0.05), PaO2 (r = -0.511, P < 0.01) respectively and a positive correlation between TF/TFPI ratio and the percentage of neutrophils (r = 0.379, P < 0.05) in AECOPD patients before treatment. There still were negative correlations between TF/TFPI ratio and TAC (r = -0.420, P < 0.05), FEV(1)% to predicted (r = -0.480, P < 0.05) respectively, and a positive correlation between TF/TFPI ratio and MDA (r = 0.451, P < 0.05) in AECOPD patients after treatment. CONCLUSIONS: There existed coagulation/anticoagulation imbalance and oxidation/antioxidation imbalance before and after treatment in AECOPD patients and their relationship was explored.

[Effects of rosiglitazone on peroxisome proliferator activated receptor-γ pathway in patients with chronic obstructive pulmonary disease].

OBJECTIVE: To explore the effects of rosiglitazone on peroxisome proliferator activated receptor-γ (PPAR-γ), nuclear factor-κB and tumor necrosis factor-α (TNF-α) in patients with chronic obstructive pulmonary disease (COPD). METHODS: From Apr. 2010 to Nov. 2010, 30 patients with acute exacerbations of COPD, 22 males and 8 females, age 54 - 87 (mean 72 ± 9) years and 24 healthy controls, 18 males and 6 females, age 52 - 80 (mean 69 ± 10) years were included. The peripheral blood mononuclear cells (PBMCs) were isolated from venous blood and then cultured. On the basis of the treatment given, the PBMCs of COPD patients were divided into 3 groups: non-treatment group, rosiglitazone treatment group (rosiglitazone group) and rosiglitazone and GW9662 treatment group (combined treatment group). Cells from the healthy controls (control group) did not receive any drug treatment. The mRNA expression of PPAR-γ and NF-κB was measured with real-time PCR. The protein expression and nuclear translocation of PPAR-γ and NF-κB were detected using immunofluorescence with laser scanning confocal microscopy. The TNF-α level in culture supernatant was measured with ELISA. One-way ANOVA and LSD-t test and the Pearson correlation coefficient were used for statistical analysis. RESULTS: The mRNA and protein levels of PPAR-γ were lower in the non-treatment group (0.52 ± 0.10, 55 ± 11) than those in the control group (1, 85 ± 9), while the levels of NF-κB mRNA and protein were higher in the non-treatment group (1.69 ± 0.07, 145 ± 17) than those in the control group (1, 118 ± 7). The mRNA and protein levels of PPAR-γ in the rosiglitazone group (4.47 ± 0.11, 204 ± 12) were significantly increased compared with the non-treatment group, while the mRNA and protein levels of NF-κB (0.33 ± 0.04, 59 ± 14) were remarkably decreased compared with the non-treatment group. The mRNA and protein levels of PPAR-γ (2.25 ± 0.31, 142 ± 23) were significantly decreased in the combined treatment group compared to the rosiglitazone group, but higher compared with the non-treatment group, while the mRNA and protein levels of NF-κB (0.64 ± 0.02, 90 ± 10) were increased compared with the rosiglitazone group, but decreased compared to the non-treatment group (F = 29.21 - 567.42, all P < 0.01). The TNF-α level was significantly higher in the non-treatment group (96.2 ± 1.4) µg/L than that in the control group (85.3 ± 1.0) µg/L. The TNF-α level in the rosiglitazone group (63.0 ± 2.5) µg/L was remarkably decreased compared with the non-treatment group, while that in the combined treatment group (83.3 ± 1.9) µg/L was increased compared with the rosiglitazone group, but decreased compared to the non-treatment group (F = 293.72, P < 0.01). The proteins of PPAR-γ and NF-κB were respectively located in cytoplasm and in nucleus in the non-treatment group, meanwhile they were located in both cytoplasm and nucleus in the control group. PPAR-γ protein was translocated from cytoplasm into nucleus and NF-κB protein was translocated from nucleus into cytoplasm in the rosiglitazone group. In the combined treatment group, PPAR-γ protein translocated from nucleus into cytoplasm and NF-κB protein partly translocated from cytoplasm into nucleus. By linear correlation analysis, PPAR-γ protein was negatively correlated with NF-κB protein and TNF-α level (r = -0.935, -0.924, all P < 0.01), while NF-κB protein was positively correlated to TNF-α level (r = 0.846, P < 0.01). CONCLUSIONS: The expression and activity of PPAR-γ were decreased in COPD patients. PPAR-γ agonist rosiglitazone inhibited inflammation in COPD through upregulating the expression and activity of PPAR-γ and inhibition of NF-κB and TNF-α. It suggests that PPAR-γ may play an important role in the inflammation of COPD.

Effects of PM2.5 exposure on the Notch signaling pathway and immune imbalance in chronic obstructive pulmonary disease.

Chronic Obstructive Pulmonary Disease (COPD) is associated with T lymphocytes subset (Th1/Th2, Th17/Treg) imbalance. Notch signaling pathway plays a key role in the development of the adaptive immunity. The immune disorder induced by fine particulate matter (PM2.5) is related to COPD. The aim of this study was to investigate the mechanism by which PM2.5 influences the Notch signaling pathway leading to worsening immune disorder and accelerating COPD development. A COPD mouse model was established by cigarette smoke exposure. PM2.5 exposure was performed by aerosol inhalation. γ-secretase inhibitor (GSI) was given using intraperitoneal injection. Splenic T lymphocytes were purified using a density gradient centrifugation method. CD4+ T lymphocyte subsets (Th1/Th2, Th17/Treg) were detected using flow cytometry. mRNA and proteins of Notch1/2/3/4, Hes1/5, and Hey1 were detected using RT-PCR and Western blot. Serum INF-γ, IL-4, IL-17 and IL-10 concentrations were measured using ELISA. The results showed that in COPD mice Th1% and Th17%, Th1/Th2 and Th17/Treg were increased, and the levels of mRNA and protein in Notch1/2/3/4, Hes1/5, and Hey1 and serum INF-γ and IL-17 concentrations were significantly increased, and Th2%, Treg%, and serum IL-4 and IL-10 concentrations were significantly decreased. COPD Mice have Th1- and Th17-mediated immune disorder, and the Notch signaling pathway is in an overactivated state. PM2.5 promotes the overactivation of the Notch signaling pathway and aggravates the immune disorder of COPD. GSI can partially inhibit the activation of the Notch signaling pathway and alleviate the immune disorder under basal state and the immune disorder of COPD caused by PM2.5. This result suggests that PM2.5 is involved in the immune disorder of mice with COPD by affecting the Notch signaling pathway and that PM2.5 aggravates COPD.

Effects of resveratrol and genistein on nuclear factor­κB, tumor necrosis factor­α and matrix metalloproteinase­9 in patients with chronic obstructive pulmonary disease.

Chronic airway inflammation and airway remodeling are the major pathophysiological characteristics of chronic obstructive pulmonary disease (COPD). Resveratrol and genistein have been previously demonstrated to have anti­inflammatory and antioxidative properties. The present study aimed to measure the inhibitory effects of resveratrol and genistein on tumor necrosis factor (TNF)­α and matrix metalloproteinase (MMP)­9 concentration in patients with COPD. Lymphocytes were isolated from the blood of 34 patients with COPD and 30 healthy subjects, then randomly divided into the following four treatment groups: Control, dexamethasone (0.5 µmol/l), resveratrol (12.5 µmol/l) and genistein (25 µmol/l) groups. After 1 h of treatment, 100 µl lymphocytes were collected for nuclear factor (NF)­κB immunocytochemical staining. After 48 h treatment, the supernatant of the lymphocytes was collected for analysis of TNF­α and MMP­9 concentration levels. The percentage of lymphocytes with positive nuclear NF­κB expression was analyzed by immunocytochemical staining. The concentration levels of TNF­α and MMP­9 were measured using radioimmunoassay and enzyme­linked immunosorbent assay, respectively. The present study demonstrated that the percentage of NF­κB­positive cells, and the levels of TNF­α and MMP­9 in lymphocytes from patients with COPD patients were significantly higher compared with healthy subjects. Additionally, there were positive correlations between the percentage of NF­κB­positive cells, and the concentration levels of TNF­α and MMP­9 in patients with COPD. All three factors were significantly reduced in lymphocytes treated with resveratrol and genistein, and the inhibitory effects of resveratrol on NF­κB, TNF­α and MMP­9 were more potent than the effects of genistein. In conclusion, resveratrol and genistein may inhibit the NF­κB, TNF­α and MMP­9­associated pathways in patients with COPD. It is suggested that resveratrol and genistein may be potential drugs candidates for use in the treatment of COPD.

Effects of Astragalus and Codonopsis pilosula polysaccharides on alveolar macrophage phagocytosis and inflammation in chronic obstructive pulmonary disease mice exposed to PM2.5.

Astragalus and Codonopsis pilosula are used for their immunomodulatory and anti-inflammatory effects. Here, we investigated the effects of Astragalus polysaccharides (APS) and Codonopsis pilosula polysaccharides (CPP) on alveolar macrophage (AM) phagocytosis and inflammation in chronic obstructive pulmonary disease (COPD) associated with exposure to particulate matter with a mean aerodynamic diameter ≤2.5µm (PM2.5). A mouse model of COPD was established by cigarette smoke exposure. PM2.5 exposure was performed by inhalation of a PM2.5 solution aerosol. APS and CPP were administered intragastrically. COPD showed defective AM phagocytosis and increased levels of interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-α in bronchoalveolar lavage fluid and serum. PM2.5 exposure aggravated the damage, and this effect was reversed by APS and CPP gavage. The results indicate that APS and CPP may promote defective AM phagocytosis and ameliorate the inflammatory response in COPD with or without PM2.5 exposure.

Sinomenine attenuates airway inflammation and remodeling in a mouse model of asthma.

Asthma is an inflammatory disease that involves airway inflammation and remodeling. Sinomenine (SIN) has been demonstrated to have immunosuppressive and anti­inflammatory properties. The aim of the present study was to investigate the inhibitory effects of SIN on airway inflammation and remodeling in an asthma mouse model and observe the effects of SIN on the transforming growth factor­ß1 (TGF­ß1)/connective tissue growth factor (CTGF) pathway and oxidative stress. Female BALB/c mice were sensitized by repetitive ovalbumin (OVA) challenge for 6 weeks in order to develop a mouse model of asthma. OVA­sensitized animals received SIN (25, 50 and 75 mg/kg) or dexamethasone (2 mg/kg). A blank control group received saline only. The area of smooth muscle and collagen, levels of mucus secretion and inflammatory cell infiltration were evaluated 24 h subsequent to the final OVA challenge. mRNA and protein levels of TGF­ß1 and CTGF were determined by reverse transcription­quantitative polymerase chain reaction and immunohistology, respectively. The indicators of oxidative stress were detected by spectrophotometry. SIN significantly reduced allergen­induced increases in smooth muscle thickness, mucous gland hypertrophy, goblet cell hyperplasia, collagen deposition and eosinophilic inflammation. The levels of TGF­ß1 and CTGF mRNA and protein were significantly reduced in the lungs of mice treated with SIN. Additionally, the total antioxidant capacity was increased in lungs following treatment with SIN. The malondialdehyde content and myeloperoxidase activities in the lungs from OVA­sensitized mice were significantly inhibited by SIN. In conclusion, SIN may inhibit airway inflammation and remodeling in asthma mouse models, and may have therapeutic efficacy in the treatment of asthma.