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.     

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.     

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.     

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 ischemic post-conditioning on Egr-1 and IL-1β expression in ischemia-reperfusion injured lung in rats

AIM: To investigate the protective effects of ischemic post-conditioning on the expression of early growth response factor 1 (Egr-1) and interleukin-1β(IL-1β) in ischemia-reperfusion injured lung in rats. METHODS: The model of lung ischemia-reperfusion injury was established in 24 rats and the rats were randomly allocated to 3 different groups (n=8 in each group): (1) sham group: only sham operation (thoracotomy) and no ischemia for 3 h; (2)ischemia-reperfusion group (I/R group): interruption of pulmonary perfusion and ventilation for 1 h followed by reperfusion for 2 h; (3) ischemic post-conditioning group (IPostC group): ischemic post-conditioning (5 min of reperfusion and 5 min of ischemia for 3 times) between the end of ischemia and the beginning of the reperfusion followed by reperfusion for 1.5 h. The lung tissues (prepared to small pieces of about 20 mg) were collected and homogenized at the end of the experiment. The concentration of myeloperoxidase (MPO) in the homogenate was determined. The wet to dry weight ratio (W/D) of the lung tissues was also measured at the end of reperfusion. The pathological changes of the lung tissues were observed under light microscope after reperfusion. The mRNA expression of Egr-1 and IL-1β in the lung tissues was detected by RT-PCR. RESULTS: Compared with sham group, the mRNA expression of Egr-1 and IL-1β, the levels of MPO and W/D were significantly increased in I/R group (P<0.05). The inflammatory responses of the lungs in I/R group were significantly severer than those in sham group. Compared with I/R group, the mRNA expression of Egr-1 and IL-1β, the levels of MPO and W/D in IPostC group were significantly decreased (P<0.05). The inflammatory responses of the lungs in IPostC group were also significantly attenuated. CONCLUSION: Ischemic post-conditioning significantly reduces ischemic reperfusion injury of the lung by inhibiting the expression of Egr-1 and IL-1β.     

Hypoxia-inducible factor-1α attenuates myocardial inflammatory injury induced by ischemia and reperfusion in rats

AIM:To investigate the role of hypoxia-inducible factor-1α (HIF-1α) stable expression in myocardial inflammatory injury induced by ischemia and reperfusion (I/R) in rats. METHODS:Male Wistar rats were randomly divided into 4 groups:sham operation (sham) group, I/R group, HIF-1α stabilizer dimethyloxalyl glycine (DMOG)+I/R group and HIF-1α inhibitor YC-1+I/R group. The protein expression of myocardial Toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) was determined by Western blot. The mRNA levels of interleukin (IL)-1β, tumor necrosis factor-α (TNF-α), IL-6, TLR4 and NF-κB were detected by real-time PCR. The myeloperoxidase (MPO) activity in the myocardial tissues was measured. HE staining was used to observe the infiltration of inflammatory cells. RESULTS:HIF-1α decreased the infiltration of inflammatory cells, the MPO activity, and the mRNA levels of inflammatory factors IL-1β, IL-6 and TNF-α in the myocardial tissues. HIF-1α also reduced the expression of TLR4 and NF-κB at mRNA and protein levels (P<0.05). CONCLUSION:The stable expression of HIF-1α has an anti-inflammatory effect on the myocardial tissues after I/R injury in rats. The mechanism may be related to the inhibition of TLR4/NF-κB signaling pathway.     

Effect of fucoidan on intestinal ischemia-reperfusion injury in rats

AIM:To investigate the effect and potential mechanism of fucoidan on intestinal ischemia-reperfusion (I/R) injury in rats. METHODS:Adult male Wistar rats were randomly divided into 3 groups:sham group, I/R group and Fucoidan+I/R group. Fucoidan at 160 mg/kg was intraperitoneally injected in rats of Fucoidan+I/R group 7 d prior to operation, and the equal volume of saline was intraperitoneally injected in rats of sham group and I/R group. The rats in I/R group and Fucoidan+I/R group underwent superior mesenteric artery occlusion for 1 h and then reperfusion for 2 h. Following reperfusion, the histomorphological changes of the ileum were examined by HE staining. The levels of diamine oxidase (DAO), D-lactic acid (D-LA), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-1β were detected in the blood samples, the levels of malondialdehyde (MDA) and glutathione (GSH), the activity of superoxide dismutase (SOD) and myeloperoxidase (MPO), and the protein levels of Bax, cleaved caspase-3 and Bcl-2 were analyzed in intestinal tissue samples. RESULTS:Compared with sham group and Fucoidan+I/R group, the serum levels of DAO, D-LA, TNF-α, IL-6 and IL-1β were significantly increased in I/R group (P<0.05), Chiu's score of intestinal tissue, MDA content, MPO activity, the levels of Bax and cleaved caspase-3 protein in the intestinal tissues were also significantly increased (P<0.05), while the tissue GSH content, SOD activity, and Bcl-2 protein levels were significantly decreased (P<0.05). CONCLUSION:Fucoidan attenuates intestinal tissue damage caused by I/R, which may be related to anti-oxidation, anti-inflammatory and anti-apoptotic effects.     

Effects of icariin preconditioning on inflammatory responses in myocar-dial ischemia-reperfusion injury

AIM:To observe the effects of icariin on myocardial ischemia-reperfusion injury. METHODS:The left anterior descending coronary artery was ligated for 30 min and then loosened for 2 h to establish the rat model of myocardial ischemia-reperfusion injury. Forty-eight healthy adult male SD rats weighing 250~300 g were randomly divided into sham group, model group, low-, middle-and high-dose icariin groups, and aspirin group. The morphological changes of the myocardium were observed by HE staining. The protein expression of NF-κB p65 in the myocardial nucleus was determined by the method of immunohistochemistry. The content of tumor necrosis factor α (TNF-α) in the myocardial tissues was detected by Western blotting. The level of interleukin 1β (IL-1β) in the serum was measured by ELISA. The activity of myeloperoxidase (MPO) in the myocardial tissues was assayed by colorimetry. RESULTS:Compared with sham group, TNF-α content, IL-1β concentration, NF-κB expression and MPO activity in all other groups increased. Compared with model group, TNF-α content, IL-1β concentration, NF-κB expression and MPO activity in low-, middle- and high-dose icariin groups and aspirin group all decreased. No significant difference of the above parameters between high-dose icariin group and aspirin group was observed. CONCLUSION: Icariin preconditioning reduces inflammatory responses in the process of myocardial ischemia-reperfusion injury in a dose-dependent manner.     

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.     

Clonidine inhibits inflammatory response in lung injury mice through cholinergic anti-inflammatory pathway

AIM:To explore the influence of clonidine on inflammatory response in lung injury mice and its possible mechanism.METHODS:Clonidine solution was intravenously injected into the mice with lung injury induced by LPS.The left upper lobe of the lung was collected to detect lung wet/dry weight ratio (W/D) and total lung water content (TLW).The concentrations of IL-6,IL-1β and TNF-α were measured by ELISA.The expression of α7 nicotinic acetylcholine receptor (α7nAChR) and high-mobility group box protein 1(HMGB1) at mRNA and protein levels was determined by RT-PCR and Western blot.After importing α7nAChR siRNA lentiviral vector or injecting exogenous HMGB1 protein,the inflammatory cytokines were detected.RESULTS:Clonidine attenuated lung injury and inhibited inflammatory reaction.Clonidine promoted the activation of cholinergic anti-inflammatory pathway by promoting α7nAChR expression.Clonidine inhibited HMGB1 expression,which promoted the secretion of IL-6,IL-1β and TNF-α.HMGB1 was negatively regulated by α7nAChR.CONCLUSION:Clonidine functions as an anti-inflammatory reagent to the lung injury mice.The mechanism may be related to activating the cholinergic anti-inflammatory pathway and inhibiting the expression of HMGB1.     

Lactulose preconditioning protects against intestinal ischemia-reperfusion injury in rats

AIM: To investigate the protective effect of lactulose preconditioning on intestinal ischemia-reperfusion (IR) injury in rats. METHODS: Thirty Sprague-Dawley rats were randomly divided into 3 groups: sham operation group, IR group and IR plus lactulose preconditioning group. Lactulose was intragastrically administered in lactulose group 7 days prior to operation, and the equal volume of saline was administered in the other 2 groups. The intestinal IR injury was induced in IR group and IR+lactulose group using bulldog clamps on superior mesenteric artery by 30 min of ischemia followed by 60 min of reperfusion. Following reperfusion, the serum samples were collected for estimating the levels of interleukin 6 (IL-6), tumor necrosis factor α (TNF-α) and IL-1β. Segments of terminal jejunum were rapidly fixed in 4% paraformaldehyde, and HE staining was applied to assess the histopathology. Apoptosis in intestinal epithelium was determined by the technique of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL). The samples of terminal jejunum were also taken for measuring malondialdehyde,superoxide dismutase and the expression of cleaved caspase-3. RESULTS: Lactulose preconditioning significantly attenuated the severity of intestinal IR injury, with inhibition of IR-induced apoptosis. Moreover, lactulose preconditioning significantly limited the release of cytokines and lipid oxidation. CONCLUSION: Lactulose preconditioning has a protective effect on intestinal ischemia reperfusion by inhibiting IR-induced apoptosis and oxidative stress.     

Effects of Radix Angelicae Sinensis on changes of IL-6, TNF-α and bFGF in renal ischemia/reperfusion injury in rabbits

AIM: To determine the effect of Radix Angelicae Sinensis(RAS) on renal ischemia/reperfusion injury in rabbits and to explore its mechanism. METHODS: Twenty-five rabbits were divided randomly into the sham operated group(Control group), renal ischemia/reperfusion injury group(IR group) and RAS+IR group. At the time point of reperfusion 48 h after renal ischemia 1 h, the renal tissue were observed by electron-microscope and the contents of creatinine(Cr) in serum, tumor necrosis factor-α(TNF-α), interleukin-6(IL-6)and basic fibroblast growth factor(bFGF) in the renal tissue were measured. RESULTS: A remarkably degenerative changes in renal tissue were showed under electronmicroscope in IR group, but the changes in RAS+IR group were slight. The contents of Cr, TNF-α and IL-6 in IR group were higher than those in Control group, these parameters in RAS+IR group were lower than those in IR group, the difference between these groups was significant(P< 0.05 or P< 0.01). At the same time, the content of bFGF in IR group was lower than that in Control group(P< 0.01), while the content of bFGF in RAS+IR group was higher than that in IR group(P< 0.01) and Control group(P< 0.05). CONCLUSION: RAS has an effect of alleviating the renal ischemia/reperfusion injury by modulating the production or release of TNF-α, IL-6 and bFGF.     

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.     

Propofol inhibits LPS-induced inflammatory response in microglia via TRPV1 ion channels

AIM:To investigate the effects of propofol (P) on the inflammatory response of microglia induced by lipopolysaccharide (LPS) and the mechanisms. METHODS:Mouse microglia BV2 cells were treated with LPS at 100 μg/L to establish a neuroinflammatory injury model. The BV2 cells were divided into 4 groups:control group (C group), model group (L group), L+P group and LPS+AMG517 group (L+A group). The level of tumor necrosis factor-α (TNF-α) in the cell culture supernatant was measured by ELISA. The mRNA expression of transient receptor potential cation channel subfamily V member 1 (TRPV1) was detected by real-time PCR. The protein levels of TRPV1, TNF-α, interleukin-1β (IL-1β), interleukin-6 (IL-6) and phosphorylated calcium/calmodulin-dependent protein kinase Ⅱ (p-CaMKⅡ) were determined by Western blot. The content of free Ca²⁺ in the microglia BV2 cells was detected by Fluo-3 AM assay. RESULTS:Compared with C group, the level of TNF-α was significantly increased in L group (P<0.01), but that in P group was not changed. Compared with L group, the level of TNF-α was significantly lower than that in L+P group within 4 h (P<0.01). Compared with C group, the mRNA expression of TRPV1 was significantly increased in L group (P<0.01). Compared with L group, the mRNA expression of TRPV1 was significantly down-regulated in L+P group (P<0.01).Compared with L group, the protein levels of TNF-α, IL-1β, IL-6 and p-CaMKⅡ and intracellular Ca²⁺ concentration were significantly lower than those in L+P group and L+A group (P<0.01). CONCLUSION:Propofol inhibits the inflammatory response of microglia by reducing the expression of TNF-α, IL-1 and IL-6, which may be related to the down-regulation of TRPV1 and p-CaMKⅡ and the reduction of intracellular Ca²⁺ concentration.     

Effect of azithromycin on airway inflammation and airway mucus hypersecretion in rats with chronic obstructive pulmonary disease

AIM: To observe the effect of azithromycin on the rats with chronic obstructive pulmonary disease (COPD), and to explore the underlying mechanism about the airway inflammation and mucus hypersecretion. METHODS: Male SD rats were randomly divided into normal control group, COPD model group, azithromycin treatment group. The COPD model was established by the method of cigarette smoking combined with intratracheal injection of LPS. Pathological changes of the bronchi and lung tissues of the rats were observed with HE staining. Pulmonary ventilation function in the rats was detected with pulmonary function instrument. The levels of IL-8, IL-17 and TNF-α in bronchoalveolar lavage fluid (BALF) were measured by ELISA. The expression of MUC5ac and TLR4 at mRNA and protein levels in bronchi and lung tissues was determined by real-time PCR and Western blot.RESULTS: HE staining showed that the changes of bronchi and lung tissues in model group were consistent with typical pathological manifestations of COPD. Compared with model group, these changes were alleviated in treatment group. The pulmonary functions in model group were significantly decreased compared with control group. The levels of IL-8, IL-17 and TNF-α in the BALF in model group were significantly increased compared with control group (P <0.05). The expression of MUC5ac and TLR4 at mRNA and protein levels in model group was significantly higher than that in control group (P <0.05). Compared with model group, the degree of the descent in pulmonary function in treatment group was significantly lessened. Compared with model group, the levels of IL-8, IL-17 and TNF-α in treatment group were significantly inhibited (P <0.05). Furthermore, the expression of MUC5ac and TLR4 at mRNA and protein levels in treatment group was significantly lower than that in model group (P <0.05). CONCLUSION: Azithromycin decreases the levels of IL-8, IL-17 and TNF-α in the BALF of COPD model rats, inhibits the protein expression of MUC5ac and TLR4 in the lung tissues, thus playing a preventive and therapeutic role to reduce airway inflammation and airway mucus hypersecretion.     

Liraglutide attenuates hyperhomocysteinemia-induced oxidative stress and inflammatory response in rat hippocampus via p38 MAPK signaling pathway

AIM: To investigate the protective effect of liraglutide (Lir), an analog of glucgon-like peptide-1 (GLP-1), on hyperhomocysteinemia (Hhcy)-induced hippocampal pathological injury and the underlying molecular mechanisms in rats. METHODS: Sprague-Dawley rats (n=40) were randomly divided into 5 groups:control (Ctrl) group, model (Hhcy) group, low-dose Lir treatment (Lir-L) group, medium-dose Lir treatment (Lir-M) group and high-dose Lir treatment (Lir-H) group. The protein levels of p-p38, p-ERK1/2, p-JNK, immunoglobulin heavy chain binding protein (BIP) and C/EBP homology protein (CHOP) were determined by Western blot and immunohistochemical staining. The activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH), and the content of malondialdehyde (MDA) were measured. The expression levels of interleukin-1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α) were examined by ELISA. RESULTS: Hhcy increased the levels of p-p38, BIP, CHOP, MDA, IL-1β, IL-6 and TNF-α,and reduced the activity of SOD and GSH, while simultaneous administration of Lir dose-dependently attenuated the Hhcy-induced oxidative stress and inflammatory responses, accompanied with the inhibition of p38 MAPK signaling pathway. CONCLUSION: Lir ameliorates Hhcy-induced oxidative stress and inflammatory injury in rat hippocampi with the mechanisms involving suppression of p38 MAPK pathway.     

Effect of intervention for mast cell function before reperfusion on intestinal ischemia-reperfusion-induced early liver injury in rats

AIM：To explore the effect of intervention for mast cell function before reperfusion on intestinal ischemia-reperfusion (IR)-induced early liver injury. METHODS：Adult SD rats (n=35) were randomized into 5 groups with 7 rats each: sham operation group (S group), IR group, cromolyn sodium treatment group (IR+C group, 25 mg/kg), ketotifen treatment group (IR+K group, 1 mg/kg), compound 48/80 treatment group (IR+CP group, 0.75 mg/kg). IR was induced by superior mesenteric artery occlusion for 75 min followed by 4 h of reperfusion. The agents were intravenously administered 5 min before reperfusion. The serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and histamine, and the liver levels of lactate dehydrogenase (LDH), tumor necrosis factor α (TNF-α), interleukin-8 (IL-8), malondialdehyde (MDA) and superoxide dismutase (SOD) were assessed. The liver histopathologic changes were also evaluated. RESULTS：IR resulted in severe liver injury as demonstrated by great increases in injury scores, concomitant significant increases in serum levels of AST, ALT and histamine, and liver levels of LDH, TNF-α, IL-8, and MDA, accompanied by reduced SOD activity (all P<0.05 vs S group). Treatment with cromolyn sodium or ketotifen markedly alleviated IR-mediated liver injury as confirmed by significant reduction of the above biomedical changes, whereas compound 48/80 further aggravated liver injury by dramatically enhancing the biomedical changes (all P<0.05 vs IR group). CONCLUSION：Inhibition of mast cell function before reperfusion may reduce early liver injury induced by intestinal ischemia reperfusion. Histamine, oxidative stress and inflammatory response may provide promising effects on it.     

Role of NOX1 in TNF-α-induced oxidative damage and inflammation in alveolar epithelial cells

AIM: To explore the role of NADPH oxidase 1 (NOX1) in tumor necrosis factor-α (TNF-α)-induced oxidative damage and inflammation in alveolar epithelial cells.METHODS: The mRNA and protein expression levels of NOX1 in alveolar epithelial cells after TNF-α treatment were determined by real-time PCR and Western blot. NOX1 siRNA and its negative control were transfected into the alveolar epithelial cells. After the induction of TNF-α, NOX1 levels in the cells were measured by real-time PCR and Western blot, and the content of malondialdehyde (MDA) in the cells was detected by thiobarbituric acid method. Xanthine oxidation assay was used to detect the activity of superoxide dismutase (SOD) in the cells. The contents of interleukin-4 (IL-4), IL-6 and IL-1β in cell culture medium were examined by ELISA. The rate of apoptosis was analyzed by flow cytometry. Western blot was used to detect the level of apoptotic protein cleaved caspase-3.RESULTS: The expression of NOX1 at mRNA and protein levels in TNF-α-induced cells was increased after induction (P<0.05). After transfection of NOX1 siRNA, the expression of NOX1 at mRNA and protein levels in the cell was downregulated (P<0.05). Transfection of siRNA negative control had no effect on the expression level of NOX1 in the cells. The content of MDA in the cells after TNF-α treatment was increased, the activity of SOD was reduced, the releases of IL-4, IL-6 and IL-1β by the cells were increased, and the apoptotic rate and the level of apoptotic protein cleaved caspase-3 were increased as compared with the cells that were not treated with TNF-α (P<0.05). The content of MDA in the cells with NOX1 knockdown induced by TNF-α was reduced, the activity of SOD elevated, and the releases IL-4, IL-6 and IL-1β, the apoptotic rate and the level of apoptotic protein cleaved caspase-3 decreased, as compared with the cells only treated with TNF-α induction (P<0.05).CONCLUSION: TNF-α induces the expression of NOX1 in the alveolar epithelial cells. Knockdown of NOX1 expression reduces cellular oxidative damage, releases of inflammatory factors, and cell apoptosis.