Effects of N-acetylcysteine combined with azithromycin on oxidative stress in rats with chronic obstructive pulmonary disease

AIM: To investigate the effects of N-acetylcysteine (NAC) combined with azithromycin (AZI) on oxidative stress in the rats with chronic obstructive pulmonary disease (COPD). METHODS: Male Wistar rats (n=60) were randomly divided into control group, model group, AZI intervention group,NAC intervention group and AZI+NAC group. The COPD model was established by passive smoking and intratracheal instillation of lipopolysaccharide. Each day 30 min prior to smoking, intragastric administration with AZI, NAC or combination of the 2 drugs was given for AZI, NAC, and AZI+NAC groups, respectively. On the 31st day, all rats were killed following lung function test. Cell counts of bronchoalveolar lavage fluid (BALF) were performed, and the contents of interleukin-8 (IL-8), interleukin-17 (IL-17) and tumor necrosis factor alpha (TNF-α) in BALF were measured by ELISA. The histopathology of the lung tissues was observed under light microscope, and the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) in the lung homogenate were measured. RESULTS: Compared with control group, the other 4 groups showed decreased pulmonary function, and inflammatory cell infiltration and alveolar destruction in histopathology. Compared with control group, the other groups showed higher white blood cells, monocyte-macrophages, neutrophils and lymphocytes in the BALF (P<0.05). Compared with model group, AZI group and NAC group, lower white blood cells, neutrophils and lymphocytes in the BALF were observed in AZI+NAC group (P<0.05). Compared with model group, IL-8, IL-17, TNF-α and MDA in AZI group, NAC group and AZI+NAC group significantly decreased (P<0.05), while SOD and GSH-Px significantly increased (P<0.05). Compared with AZI or NAC group, IL-8, IL-17, TNF-α and MDA in AZI+NAC group significantly decreased (P<0.05), while SOD and GSH-Px increased significantly (P<0.05). CONCLUSION: Both NAC and AZI attenuate the lung inflammation and oxidative damage in COPD model rats. Combined medication exerts preferable anti-oxidation effects, which might be more suitable for the treatment of COPD.     

CB2 receptor agonist JWH133 exerts protective effects on rat model of paraquat-induced acute lung injury

AIM: To study the protective effects of cannabinoid CB2 receptor agonist JWH133 on rat acute lung injury induced by paraquat (PQ).METHODS: Male Sprague-Dawley rats (n=72) were randomly divided into 4 groups. PQ group: PQ was administered intraperitoneally at the dose of 20 mg/kg; Low-dose JWH133 pretreatment group (L-JWH133 group): JWH133 (5 mg/kg, ip) was administered 1 h before PQ exposure; high-dose JWH133 pretreatment group (H-JWH133 group): JWH133 (20 mg/kg, ip) was administered 1 h before PQ exposure; control group: 1 mL saline was administered intraperitoneally. Arterial blood, bronchoalveolar lavage fluid (BALF) and lung tissue samples were collected at 8 h, 1 d and 3 d after PQ exposure. PaO2 and the levels of TNF-α and IL-1β in BALF were measured via blood gas analyzer and ELISA, respectively. The pathological changes and lung injury scores were assessed at 3 d after PQ exposure. NF-κB and AP-1 protein levels were also determined by Western blotting.RESULTS: The decrease in PaO2, structural injury of the lung tissues, interstitial pulmonary edema, and the increase in IL-1β and TNF-α in BALF were observed in PQ-treated rats compared with control group. JWH133 pretreatment reduced the degree of lung tissue injury, decreased the levels of IL-1β and TNF-α in BALF and the NF-κB and AP-1 protein expression in the lung tissue compared with PQ group, especially in H-JWH133 group. CONCLUSION: CB2 receptor agonist JWH133 inhibits NF-κB and AP-1 protein expression in the lung tissues, and reduces the secretion of IL-1β and TNF-α in BALF after paraquat exposure, thus attenuating paraquat-induced acute lung injury.     

Effect of endothelin-1 on inflammation and oxidative stress in COPD

AIM:To investigate the effect of endothelin-1 on inflammation and oxidative stress in chronic obstructive pulmonary disease (COPD). METHODS:Healthy non-smokers (30 cases), healthy smokers (30 cases) and COPD patients (29 cases) were collected and induced to produce sputum. The concentration of endothelin-1 in the induced sputum was detected. The model of emphysema was established by cigarette smoke extract to stimulate SD rats. Endothelin A receptor antagonist BQ123 and non-selective endothelin receptor antagonist bosentan were used to intervene with the model rats. The experiment was divided into control group, cigarette-treated group, selective antagonist group and non-selective antagonist group. The protein levels of cleaved caspase-3 in the lung tissue were determined by Western blot. Gelatin zymography was used to analyze the activity of matrix metalloproteinase-2 (MMP-2) and MMP-9 in the lung tissue. The levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were measured by ELISA. The bioantioxidant power (BAP) was detected by BAP assay kit. RESULTS:The concentrations of endothelin-1 in induced sputum of healthy smokers and COPD patients were significantly higher than that of healthy non-smokers (P<0.05), and the level of endothelin-1 in COPD patients was significantly higher than that in healthy smokers (P<0.05). The levels of cleaved caspase-3, MMP-2, MMP-9, TNF-α and IL-1β in the lung tissues from cigarette-treated group were significantly higher than those in control group (P<0.05). The endothelin A receptor antagonist significantly inhibited the levels of cleaved caspase-3, MMP-2, MMP-9, TNF-α and IL-1β (P<0.05). The serum BAP in cigarette-treated group was significantly lower than that in control group (P<0.05). However, endothelin A receptor antagonist significantly increased serum BAP (P<0.05). CONCLUSION:Endothelin-1 may play an important role in the development and progression of COPD through regulating apoptosis, matrix metalloproteinase activity, inflammation and oxidative stress.     

Bone marrow-derived mesenchymal stem cell-conditioned medium atte-nuates LPS-induced acute lung injury in mice

AIM:To explore the effects of bone marrow-derived mesenchymal stem cells-conditioned medium (MSCs CdM) on lipopolysaccharide (LPS)-induced acute lung injury. METHODS:Lung injury was induced in mice by intraperitoneal injection of LPS. The mice were given a tail vein injection of MSCs CdM or normal saline 1 h after LPS administration. The mice were killed by an intraperitoneal injection of pentobarbital 6 h after LPS injection for either bronchoalveolar lavage fluid (BALF) and serum collection or lung histological analysis. RESULTS:Compared with control group, the BALF levels of protein, interleukin-10 (IL-10) and keratinocyte growth factor (KGF), the serum levels of tumor necrosis factor α (TNF-α) and IL-6, and the myeloperoxidase (MOP) activity in the lung tissues were significantly higher in LPS group, and severe pathological damages in the lung tissues were also observed. Treatment with MSCs CdM significantly reduced the BALF prtein level, the seum TNF-α and IL-6　levels and the lung MPO activity, and attenuated the lung pathological damages, but further increased the levels of IL-10 and KGF in the BALF. CONCLUSION:Treatment with MSCs CdM attenuates the lung injuries induced by LPS, which may be via regulating the expression of TNF-α, IL-6, IL-10 and KGF.     

Effect of Toll-like receptor 4 signal transduction on airway inflammation in infant asthmatic rat

AIM: To study the change and regulatory mechanism of Toll-like receptor 4 (TLR4) on eosinophil (EOS) apoptosis. METHODS: Twenty-seven SD rats were randomly divided into control group (A), asthma group (B) and dexamethasone group (D). Asthmatic model rats were sensitized and repeatedly exposed to aerosolized ovalbumin. Pulmonary tissues were observed under light microscope (LM). The inflammatory cells in BALF were counted. The levels of IL-10 in serum were measured by ELISA. Expressions of TLR4 mRNA were tested by hybridization. The apoptotic EOS was detected by TUNEL.RESULTS: (1) LM showed that inflammatory cells infiltrated around the bronchus, airway mucous plug in group B, obviously lightened in group D. (2) Inflammatory cells count in BALF: the total cellular score, EOS absolute count and EOS% in group B were significantly increased (P<0.01). Compared to group B, a significant decrease in group D was observed (P<0.01). (3) The level of IL-10 in group B was significantly higher than that in group A and in group D (P<0.01). (4) No significant difference (P>0.05) of TLR4 mRNA expression was observed between group A and group B. However, that in group D were significantly increased (P< 0.01). (5) Percentages of apoptotic EOS in group B were significantly lower than those in group A (P<0.01), those in group D were significantly increased (P<0.01). A significant correlation between TLR4 mRNA and apoptotic EOS (r=0.612, P<0.01) was observed. CONCLUSION: Dexamethasone can increase IL-10 secretion, induce EOS apoptosis, which may correlate with TLR4 signal transduction.     

Protective effect of N-acetylcysteine on mice with acute lung injury induced by H9N2 swine influenza virus

AIM: To investigate the effects of N-acetylcysteine (NAC) on acute lung injury induced by H9N2 swine influenza virus (SIV) in mice. METHODS: BALB/c mice were used to establish the animal model of acute lung injury by nasal inoculation of H9N2 SIV. The mice were divided into control group (without SIV infection), H9N2 SIV group (inoculation of H9N2 SIV) and NAC group (inoculation of H9N2 SIV plus pretreatment with NAC). The pulmonary edema was evaluated by determining the lung wet weight/dry weight (W/D) ratio. The pathological changes of the lung tissues were observed. The concontrations of TNF-α, IL-1β and IL-6 in bronchoalveolar lavage fluid (BALF) were measured.The virus titer, T-SOD activity, MPO activity and MDA content in the homogenate of the lung tissues were detected. RESULTS: Treatment with NAC decreased the morality of infected mice, and significantly prolonged the survival time of infected mice. The pathological changes of the lung tissues, the lung W/D ratio and the lung index were relieved when SIV infected the mice treated with NAC. Treatment with NAC significantly decreased the infiltration of inflammatory cells including macrophages, lymphocytes and neutrophils in the BALF. The levels of TNF-α, IL-6, IL-1β and MDA and the activity of MPO were also decreased. Treatment with NAC also significantly increased the T-SOD activity. CONCLUSION: The protective effect of NAC on the acute lung injury mouse model is related to suppression of the oxidative stress and inflammatory responses.     

Effect of IFN-γ inhalation on the cellular immunity of the lungs

AIM:To study the effect of IFN-γ inhalation on the anti-infection ability of the lungs in the immunocompromised host. METHODS:The immunological factors in the immunocompromised rats and the immunocompromised rats administrated IFN-γ via aerosol were investigated after 1, 3, 7 days when they were injected Candida albicans via tracheal. The Canidda albicans count of the left lung was also determined after 7 days when injecting pathogen. RESULTS:The Canidda albicans count of the left lung in IFN-γ group was significantly less than that of control group. The phagocyting and bactericidal percentages, Ia antigen expression percentages, the levels of TNF-α, IL-1β and IL-6 in the culture supernatant of the AM, the activity of IFN-γ and TNF-α in BALF (except the TNF-α on 7 th day) in IFN-γ group were markedly higher than those in control group. The expression of IFN-γ and IL-1β pulmonary tissues in IFN-γ group was higher than that in control group. The expression of TNF-α in IFN-γ group was less than that in control group. The expression of IL-6 was no changes between two groups. The levels of IFN-γ, IL-1β and IL-6 in the blood (except IL-1β on 3 rd day), and the killing ability of the lymphocytes in blood had no difference between two groups. CONCLUSION:Administration of IFN-γ via aerosol obviously enhanced the anti-infection ability of the lungs in the immunocompromised host, but has no influence on the whole body cellular immunity.     

Effects of Jiedu-Qingfei mixture on NF-κB and p38 MAPK pathways in lung tissues of rats with Mycoplasma pneumoniae infection

AIM: To observe the therapeutic effect of Jiedu-Qingfei mixture on Mycoplasma pneumoniae (MP)-infected rat lung tissues and to explore its mechanism. METHODS: SD rats (n=40) were randomly divided into 4 groups:blank control group, model group, Jiedu-Qingfei group and positive control group, with 10 rats in each group. The rats in experimental groups were slowly dripped with 1×10⁹ CFU/L MP solution into their nostrils for 4 d. One rat in each group was sacrificed for MP nucleic acid detection at the second day after inoculation, and the other rats were given gavage therapy. The rats in blank control group and model group were intragastrically given the same volume of normal saline, the rats in Jiedu-Qingfei group were given 8 mL/kg Jiedu-Qingfei mixture daily for 4 weeks, and the rats in psoitive control group were given dexmethasone sodium phosphate (0.5 mg·kg^-1·d^-1). After the experiment, the rats were killed. The serum and bronchoalveolar lavage fluid (BALF) were collected for detecting the levels of interleukin-12 (IL-12), IL-13 and TNF-α by ELISA. The right lung tissues were used for pathological observation and HE staining, while the left lung tissues were used to detect the expression of NF-κB p50, I-κBα and p38 mitogen-activated protein kinase (p38 MAPK) at mRNA and protein levels. RESULTS: The results of MP nucleic acid detection showed that all the rats except blank control group were MP nucleic acid positive, indicating that the rat model of MP infection was successfully established. On the 1st day of the treatment, the pathological scores of the lung tissues in model group and Jiedu-Qingfei group were significantly higher than those in blank control group (P<0.05). After treatment, the pathological scores of the lung tissues in mo-del group were significantly higher than those in blank control group and Jiedu-Qingfei group. The levels of IL-12 in the serum and BALF in model group were significantly lower than those in blank control group after MP infection (P<0.05), while those after treatment with Jiedu-Qingfei mixture were significantly higher than those in model group (P<0.05). The levels of IL-13 and TNF-α in the serum and BALF of MP-infected rats were increased significantly, while those after treatment with Jiedu-Qingfei mixture were significantly lower than those in model group (P<0.05). The mRNA expression levels of NF-κB p50 and p38 MAPK in model group were increased significantly (P<0.01). After treatment, the mRNA expression levels of NF-κB p50 and p38 MAPK were decreased significantly compared with model group (P<0.01). The mRNA expression level of I-κBα in model group was significantly lower than that in control group. After treatment, the mRNA expression of I-κBα in Jiedu-Qingfei group was significantly higher than that in model group (P<0.05). The protein levels of NF-κB p50 and p38 MAPK in the lung tissues of model group were significantly higher than those of blank control group. After treatment, the protein expression of NF-κB p50 and p38 MAPK was decreased significantly. The protein level of I-κBα in model group was significantly lower than that in blank control group, and after treatment with Jiedu-Qingfei mixture, the protein expression level of I-κBα was increased significantly (P<0.05). CONCLUSION: Jiedu-Qingfei mixture may attenuate lung tissue inflammation caused by MP through NF-κB and p38 MAPK pathways.     

Effect of Kechuanning on airway remodeling and protein level of p-ERK1/2 in lung tissues of asthmatic rats induced by virus

AIM:To investigate the effect of Kechuanning on airway remodeling and the protein level of p-ERK1/2 in lung tissues of asthmatic rats induced by virus. METHODS:The asthmatic rat model induced by respiratory syncytial virus was established. The experimental rats were divided into normal group, asthma model group, low dose (0.33 mL/kg), middle dose (3.0 mL/kg) and high dose (10 mL/kg) of Kechuanning groups, and PD98059 (3 mg/kg) group. The airway responsiveness of the rats was measured by animal ventilator. The pathological changes of the lung tissues were observed by HE staining. PAS staining and Masson staining were used to observe goblet epithelial cells metaplasia and airway collagen deposition. The expression of matrix metalloproteinases-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in the lung tissues of the rats was detected by immunohistochemical staining. The protein levels of ERK1/2 and p-ERK1/2 were determined by Western blot. RESULTS:Compared with model group, the airway responsiveness of the rats in middle dose and high dose of Kechuanning groups was significantly decreased (P<0.01), the injury of lung tissues was significantly decreased, the goblet epithelial cells metaplasia and airway collagen deposition were significantly reduced (P<0.01), and the expression of MMP-9 and TIMP-1 in the lung tissues was also significantly decreased (P<0.01). In addition, the protein level of p-ERK1/2 in high dose of Kechuanning group was significantly decreased compared with model group (P<0.01). CONCLUSION:Kechuanning may treat asthma by regulating the expression of p-ERK1/2 in the lung tissues and improving the airway remodeling symptoms of asthmatic rats induced by virus.     

Role of p38 MAPK-HSP27 signaling pathway in rat acute lung injury induced by lipopolysaccharide

AIM: To observe the role of p38 mitogen-activated protein kinase (p38 MAPK)-heat-shock protein 27 (HSP27) signaling pathway in lipopolysaccharide-induced acute lung injury (ALI) in rats. METHODS: Wistar rats were randomly divided into control group, ALI group and ALI+SB203580 group. After the experimental model was established, the rats were sacrificed. The pathological changes of the lung and the changes of F-actin and G-actin in the endothelial cells were observed. The ratio of wet weight to dry weight (W/D) of the lung tissues was measured. The protein levels in bronchoalveolar lavage fluid (BALF) were detected. The levels of IL-6 and TNF-α in serum and BALF were tested. The concentrations of p-p38 and p-HSP27 in the lung were determined. RESULTS: In ALI group, the protein levels in BALF and W/D ratio of the lung increased significantly at 2 h. The levels of TNF-α and IL-6 in serum and BALF began to increase at 2 h, which had significant difference as compared with control group. Aleolar epithelial swelling, alveolar walls widening, alveolar interstitial and cavity edema, and the exudation of alveolar inflammation cells, red blood cells and protein were observed in ALI group. The protein levels in BALF and W/D ratio of the lung in ALI+SB203580 group were much less than those in ALI group. The exudation of alveolar inflammation cells, red blood cells and protein, and the interstitial and alveolar edema in ALI+SB203580 group alleviated as compared with ALI group. The expression of p-p38 MAPK and p-HSP27 in the lung at 2 h in ALI group was higher than that in control group. F-actin expression in ALI group obviously increased than that in control group at time points of 0 h and 8 h. Compared with ALI group, the expression of p-HSP27 and F-actin in ALI+SB203580 group was reduced. CONCLUSION: Lipopolysaccharide activates p38 MAPK-HSP27 signaling pathway and induces lung injury. Blockage of p38 MAPK-HSP27 signaling pathway may reduce lung injury.     

Effects of hesperidin on inflammatory cytokine levels in chronic bronchitic rats

AIM: To observe the effects of hesperidin on the inflammatory cytokine levels in chronic bronchitic rats.METHODS: The rats were randomly divided into control group, model group and hesperidin treatment group. The rat model of chronic bronchitis was established by smoking. The pathological changes of the bronchial and lung tissues were observed by HE staining. The levels of TNF-α, IL-6 and IL-10 in the bronchoalveolar lavage fluid were analyzed by ELISA. The protein expression levels of ICAM-1 and VCAM-1 were detected by Western blot.RESULTS: Compared with model group, hesperidin treatment significantly reduced inflammatory infiltration in the bronchial and lung tissues, improved the integrity of the alveolar structure, and decreased the levels of TNF-α and IL-6 in the bronchoalveolar lavage fluid, but had no effect on the IL-10 level. Moreover, the protein expression of ICAM-1 and VCAM-1 were dramatically inhibited after hesperidin treatment.CONCLUSION: Hesperidin decreases the levels of TNF-α and IL-6 in the bronchoalveolar lavage fluid in the rats with chronic bronchitis, which may be associated with the inhibition of ICAM-1 and VCAM-1 expression.     

Effect of hydrogen sulfide on airway inflammation induced by ozone in mice

AIM: To investigate the effect of hydrogen sulfide (H₂S) on airway inflammation induced by ozone (O₃) exposure and its mechanisms.METHODS: C57BL/6 mice (n=32) were randomly divided into control group, O₃ group, NaHS+O₃ group and NaHS group. The mice in O₃ group and O₃+NaHS group were exposed to 2.14 mg/m³ O₃ for 3 h on days 1, 3 and 5, while the mice in control group and NaHS group were exposed to filtered air. NaHS (14 μmol/kg) was administered intraperitoneally to the mice in NaHS group and O₃+NaHS group 30 min before each exposure. After the last exposure for 24 h, the airway responsiveness was determined, and bronchoalveolar lavage fluid (BALF) was collected for counting inflammatory cells and measuring total protein concentration. The lung tissues were collected for observing the morphological changes with HE staining. The levels of interleukin-6 (IL-6), interleukin-8 (IL-8), malondialdehyde (MDA) and NF-κB p65 protein in the lungs were determined.RESULTS: Compared with control group, the airway responsiveness, inflammatory cells, protein concentration, inflammation score, levels of IL-6, IL-8, MDA and NF-κB p65 in O₃ group increased significantly, but these in NaHS+O₃ group decreased compared with O₃  group.CONCLUSION: The present findings suggest that H₂S attenuates O₃ induced airway inflammation by inhibiting NF-κB expression and preventing lipid peroxidation.     

Effect of high-fructose diet on adipose tissue renin-angiotensin system in rats

AIM: To observe the effects of high-fructose diet on adipose tissue inflammation and renin-angiotensin system (RAS), and to reveal the role of Toll-like receptor 2 (TLR2) in this process.METHODS: Male SD rats (n=16) were randomly divided into control group, high fructose group, high fructose+siRNA negative control group, and high fructose+TLR2-siRNA group. The rats in control group were fed with a standard chow diet. The rats in high fructose group were fed with a diet with 60% fructose, and the rats in high fructose+TLR2-siRNA group and high fructose+siRNA negative control group were transfected with TLR2 siRNA and scrambled siRNA, respectively. Serum uric acid was measured and visceral adipose tissue was weighed at the 14th week. The levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), angiotensinogen (AGT), and angiotensin Ⅱ (Ang Ⅱ) were measured by ELISA. Infiltrating macrophages in the adipose tissues were measured with immunohistochemistry. The mRNA expression of IL-6, TNF-α, monocyte chemoattractant protein-1 (MCP-1), AGT, angiotensin-converting enzyme 1 (ACE1), angiotensin Ⅱ type 1 receptor (AT1R), and angiotensin Ⅱ type 2 receptor (AT2R) was detected by RT-qPCR. The protein level of TLR2 was determined by Western blot.RESULTS: High fructose-fed rats showed elevated serum uric acid, raising fat content, higher serum concentrations of IL-6, TNF-α, AGT and AngⅡ, and more infiltrating macrophages in the adipose tissues (P<0.05). Moreover, the mRNA levels of IL-6, TNF-α,MCP-1, AGT, ACE1, AT1R and AT2R in the adipose tissues were increased (P<0.05). When high fructose-fed rats were transfected with TLR2-siRNA, the dramatic decreases in TLR2 protein level and number of infiltrating macrophages in the adipose tissues were found. Both in serum and adipose tissues, the mRNA levels of inflammatory cytokines and RAS components were all significantly decreased (P<0.05).CONCLUSION: High-fructose diet up-regulates RAS in adipose tissues via activation of TLR2 inflammation signaling pathway.     

Adipolin/CTRP12 protects against LPS-induced ARDS by up-regulating alveolar epithelial sodium channel in mice

AIM: To investigate the effect of adipolin/CTRP12 in LPS-induced acute respiratory distress syndrome(ARDS) and its potential regulation on alveolar epithelial sodium channel(ENaC) in mice. METHODS: C57BL/6J mice(n=40) were randomly divided into control group, LPS group, adipolin group and wortmannin(PI3K inhibitor) group with 10 mice in each group using random number table. The pathological changes of the lung tissues were evaluated by HE staining. The alveolar fluid clearance(AFC) was measured by Evans blue-marked albumin, and the concentrations of total protein in bronchoalveolar lavage fluid(BALF) were assessed by bicinchoninic acid(BCA) method. In BALF, the levels of IL-1β and TNF-α were determined by ELISA, and the activity of myeloperoxidase(MPO) was detected by an MPO assay kit. The total cell counts and polymorphonuclear neutrophil(PMN) counts in the BALF were analyzed by Giemsa staining. The mRNA levels of α-ENaC were assessed by qPCR, while the protein levels of α-ENaC and p-Akt were determined by Western blot. RESULTS: Compared with control group, the classic ARDS pathological changes were observed in the mice in LPS group, manifesting by severe pathological lung injury(P<0.05), increases in W/D weight ratio, total protein levels, cell counts, MPO activitiy, and IL-1β and TNF-α levels in the BALF, and decrease in AFC(P<0.05), accompanied by down-regulated levels of α-ENaC and p-Akt in the lung tissues(P<0.05). The deteriorating effects triggered by LPS were significantly reversed by administration of adipolin. However, PI3K inhibitor wortmannin canceled the beneficial effects of adipolin on LPS-induced ARDS, as evidenced by aggravated lung injury, increased levels of W/D weight ratio, protein levels, cell counts, MPO activity, and IL-1β and TNF-α levels in the BALF(P<0.05), and decreased levels of AFC, α-ENaC and p-Akt in the lung tissues. CONCLUSION: Adipolin protects against LPS-induced ARDS in the mice by up-regulating α-ENaC and enhancing AFC via PI3K/Akt signal pathway.     

Effects of N-acetylcysteine on Clara cells and CC16 in rat COPD model

AIM: To investigate the effects of N-acetylcysteine (NAC) on the number of Clara cells and secretion of Clara cells secretory protein (CC16) in rat chrohic obstructive pulmonary disesae (COPD) model.METHODS: Thirty rats were divided into control, COPD and NAC groups (n=10). The change of Clara cell ultrastructure was detected through transmission electron microscope. The number of Clara cells and synthesis of CC16 were measured by immunohistochemistry. The CC16 levels in bronchoalveolar lavage fluid (BALF) and serum were tested by ELISA. The level of CC16 mRNA in lung was determined by RT-PCR.RESULTS: The percentage of Clara cells in terminal bronchioles in the COPD group was significantly decreased than that in the control (P<0.01), and the percentage in NAC group was significantly higher than that in COPD group (P<0.01). The levels of CC16 in the BALF and serum in COPD group were significantly lower than those in control group (P<0.01, respectively), and the levels of CC16 in NAC group were significantly higher than those in COPD group (P<0.05, respectively). The expression of CC16 mRNA in COPD group was weaker than that in control group and NAC group (P<0.01, respectively).CONCLUSION: The number of Clara cells and the secretion of CC16 decrease in a rat model of COPD. Antioxidant NAC can enhance the synthesis and secretion of CC16, which may be a mechanism for the suppression of airway inflammation.     

Influence of Cordyceps sinensis on cytokine profile of dendritic cells in chronic obstructive pulmonary rat model

AIM: To investigate the effect of Cordyceps sinensis (CS) on dendritic cells (DCs) in the rat model of chronic obstructive pulmonary disease (COPD). METHODS: Eighteen Sprague-Dawley male rats were randomly divided into 3 groups: control group, COPD group and CS group.The rats in the latter 2 groups were exposed to cigarette smoking for 8 weeks with (CS group) or without (COPD group) CS treatment. The rats in control group were maintained under normal condition. After 8 weeks,the histological changes of the right lung were observed under microscope. The DCs from the 3 groups were harvested and the supernatants of DCs were analyzed for the levels of TNF-α and IL-12 p70 by commercially available ELISA kit. The DCs were then washed and cocultured in vitro with autologous T cells purified by a nylon cotton column. The supernatants of DCs-T coculture were collected after 72 h incubation, and analyzed for the levels of interleukin-5 (IL-5) and interferon-γ (IFN-γ) by ELISA. RESULTS: Analysis of the rat lung parenchyma revealed a significant decrease in the mean alveolar number, an indicator of alveolar density, in COPD group (38±16) and CS group (48±9) in comparison with control group (62±8). The mean alveolar number tended to be increased in CS group than that in COPD group, although this difference did not achieve statistical significance (P>0.05). The concentrations of TNF-α and IL-12 p70 in the culture supernatants of DCs and IFN-γ in the supernatants of DCs-T cocluture were up-regulated in CS group as compared with those in COPD group and control group (P<0.05). The level of IL-5 in the DCs-T coculture supernatants of the 3 groups did not show differences with statistical significance (P>0.05). CONCLUSION: The therapeutic effects of CS on COPD rats may be related to modulation of Th1 and Th2 cell functions. This effect is probably mediated through IL-12 p70 produced by DCs and Th1 cytokine IFN-γ produced by autologous T cells.     

Effects of Maxing-Shigan decoction on airway remodeling and expression of MMP-9 and TIMP-1 in lung tissues of asthmatic mice

AIM:To investigate the effects of Maxing-Shigan decoction on airway remodeling and expression of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the lung tissues of asthmatic mice, and to explore its possible mechanism in treatment of asthma. METHODS:The BALB/c mice were divided into blank control group, model group, low-dose Maxing-Shigan decoction group, middle-dose Maxing-Shigan decoction group, high-dose Maxing-Shigan decoction group and positive control group. The mice were sensitized and challenged with ovalbumin to establish asthma model. The mice in blank control group and model group were given saline by oral administration before 30 min of suscitation. The mice in low-dose, middle-dose and high-dose Maxing-Shigan decoction groups were given Maxing-Shigan decoction at 5.0 g/kg, 10.0 g/kg and 20.0 g/kg, respectively, by oral administration before 30 min of suscitation. The mice in positive control group was given dexamethasone at 0.005 g/kg by oral administration before 30 min of suscitation. After consecutive administration for 7 d, the variations of airway responsiveness, the percentage of the goblet cells, the collagen deposition, and the eosinophil (EOS) counts in bronchoalveolar lavage fluid (BALF) of each group were observed. The protein levels of MMP-9 and TIMP-1 in the lung tissues were determined by ELISA and Western blot. The mRNA expression of MMP-9 and TIMP-1 was detected by RT-qPCR. RESULTS:Compared with blank control group, the airway responsiveness, the goblet cell percentage, the collagen deposition, the EOS counts in BALF, the protein levels of MMP-9 and TIMP-1, and the mRNA expression of MMP-9 and TIMP-1 were significantly increased in model group (P<0.01). Compared with model group, all of the indexes were reversed in low-dose, middle-dose and high-dose Maxing-Shigan decoction groups and positive control group (P<0.05 or P<0.01). CONCLUSION:Maxing-Shigan decoction improves airway remodeling in asthma model mice by down-regulating the expression of MMP-9 and TIMP-1.     

Effects of nacetylcysteine on cigarette smoke-induced airway inflammation

AIM: To study the effects of nacetylcysteine on cigarette smoke-induced airway inflammation. METHODS: SD rats were divided into three groups randomly: control, cigarette smoking and cigarette smoking plus nacetylcysteine (NAC). Animals were treated for four weeks. Airway inflammation was assessed with light microscope. The concentrations of IL-8 and glutathione (GSH) in bronchoalveolar lavage fluid (BALF) were measured by ELISA. The expression of nuclear factor-κB (NF-κB) in the cells of BALF was detected with EMSA. RESULTS: Airway inflammation in NAC treatment group was significantly decreased than that in cigarette smoking group. GSH levels in BALF in NAC treated groups were significantly higher than those in cigarette smoking group. IL-8 levels in BALF in NAC treated groups were significantly lower than those in cigarette smoking group. Expression of NF-κB in the cells of BALF was much lower than that in the cigarette smoking group. CONCLUSION: NAC not only increases oxidative capacity in the bronchial, but also reduces the express of NF-κB, which inhibits the IL-8 production. At last it further reduces the airway inflammation.     

Effects of tripterygium glycosides combined with dexamethasone on TLRs/NF-κB signaling pathway in EAE rats

AIM: To investigate the role of TLRs/NF-κB pathway in experimental allergic encephalomyelitis (EAE) rats treated with tripterygium glycosides (TG) + dexamethasone (DX). METHODS: Lewis rats were used in the study and divided into control group, EAE model group, therapy 1 group (EAE rats treated with DX) and therapy 2 group (EAE rats treated with DX+TG). The mean clinical score of the rats was determined. The expression of TLR4 and TLR9 at mRNA and protein levels was detected by the methods of real-time quantitative RT-PCR and immunohistochemistry. The protein level of NF-κB p65 was also measured. The levels of TNF-α, IL-1β and IL-6 were assayed by ELISA. RESULTS: The mean clinical scores at 5th, 16th and 20th day were lower in therapy 1 group and therapy 2 group than that in EAE model group. The mean clinical score in therapy 2 group was even lower than that in therapy 1 group. At the 16th day (the peaking period), the mRNA expression of TLR4 and TLR9 in therapy 1 group and therapy 2 group were obviously lower than that in EAE model group. The protein levels of TLR4, TLR9 and NF-κB p65 were also significantly lower in therapy 1 group and therapy 2 group than those in EAE model group at peak stage of EAE. The levels of TNF-α, IL-1β and IL-6 were lower in therapy1 group and therapy2 group than those in EAE model group. The significant differences of the mean clinical score, the mRNA expression of TLR4 and TLR9, the positive ratio of NF-κB p65 and the levels of TNF-α, IL-1β and IL-6 between therapy 1 group and therapy 2 group were found. The result of orthogonal factorial analysis of variance indicated that the difference of therapeutic effect between DX and DX+TG was significant (F=75.749, P<0.01). CONCLUSION: The TLRs/NF-κB pathway takes part in the pathological process of EAE. TG combined with DX alleviates the symptoms of EAE by suppressing inflammatory and immunological reactions of EAE.