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.     

Cucurbitin E relieves airway inflammation by inhibiting MAPKs/NF-κB signaling pathways in asthmatic mice

AIMTo investigate the effects of cucurbitacin E on airway inflammation and the signaling pathways of MAPKs and NF-κB in asthmatic mice. METHODSHealthy mice (n=40) were randomly divided into control group, model group, low-dose cucurbitacin E group, high-dose cucurbitacin E group and dexamethasone group. Ovalbumin sensitization was used to induce asthma in the mice. The protein levels of p-JNK, p-ERK1/2, p-p38 MAPK and p-p65 in the lung tissues were determined by Western blot. RESULTSCompared with control group, the numbers of inflammatory cells, such as eosinophils, lymphocytes and neutrophils, were significantly increased in model group, and the activity of MAPKs and NF-κB signaling pathway-related proteins was significantly enhanced. Cucurbitin E at high dose attenuated airway inflammation in asthmatic mice, and significantly inhibited the activity of MAPKs and NF-κB signaling pathway-related proteins. Histopathological results showed proliferation of goblet cells and bronchial mucosal epithelial cells, infiltration of inflammatory cells in the alveoli, and narrow alveolar cavity in model group, while the pathological changes were significantly alleviated in cucurbitin E treatment groups. CONCLUSION Cucurbitin E improves airway inflammation in asthmatic mice, and its mechanism may be related to the inhibition of MAPKs and NF-κB signaling pathways.     

Expression of matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-1 and collagen type IV in lung of rats with multiple organ dysfunction syndrome

AIM: To determine the expression of matrix metalloproteinase-9 (MMP-9), tissue inhibitor of me-talloproteinase-1 (TIMP-1) and collagen type IV (IV-C) in the lung of rats with multiple organ dysfunction syndrome (MODS) and to investigate the mechanism of lung injury in MODS. METHODS: Adult male Sprague-Dawley (SD) rats (n=40) were randomly divided into sham control group and cecal ligation and puncture (CLP) model group. The rats in CLP group were divided into 4 subgroups as different intervals (6 h, 12 h, 24 h and 48 h), and there were 8 rats in each group. The rat model of MODS was established by CLP. All rats were sacrificed at various intervals. The functions of the liver, kidney and lung were determined by blood biochemical and blood gas analysis. The morphological changes of the lung tissues were observed with HE staining. The serum levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, MMP-9 and TIMP-1 were measured by ELISA. The expression of MMP-9 and TIMP-1 in the lung tissues was detected by RT-PCR and immunohistochemistry, and the expression of IV-C in the lung tissues was detected by immunofluorescence and Western blot. RESULTS: Compared with sham control group, the functions of the liver, kidney and lung were damaged at different degrees in model groups. No histopathological change in the lung tissues of sham control group was found, and the lung injury was serious in model groups. Compared with sham control group, the serum levels of TNF-α, IL-1β, MMP-9 and TIMP-1 in model groups increased significantly (P<0.05) and peaked at the interval of 12~24 h after modeling (P<0.01). The expression of MMP-9 and TIMP-1 in the lung tissues of model groups increased, and peaked at 12 and 24 h, respectively (P<0.01). The protein level of IV-C in MODS 6 h group was not changed as compared with control group, while that at the interval of 12~48 h after modeling was significantly decreased and dropped to the lowest at 24 h (P<0.01). CONCLUSION: MMP-9 and TIMP-1 play important roles in lung injury of MODS rats by regulating the synthesis and decomposition of IV-C which is the main component of extracellular matrix.     

Effects of mitogen activated protein kinase on γ-glutamylcysteine synthase in lung of guinea pigs with bronchial asthma

AIM: To investigate the effects of mitogen activated protein kinase on γ-glutamylcysteine synthase (γ-GCS) in lung of guinea pigs with bronchial asthma.METHODS: Twenty adult male guinea pigs were divided into asthmatic group and control group (10 in each group).Asthmatic model was established by ovalbumin intraperitoneal injection combined with inhalation.The numbers of total and inflammation cells in bronchoalveolar lavage fluid (BALF) were measured.The γ-GCS-h mRNA in lung tissue was examined by in situ hybridization and RT-PCR.Immunohistochemistry was used to detecte the expression of γ-GCS,phosphorylated extracellular signal regulated kinase (p-ERK),phosphrylated c-Jun amino terminal kinase (p-JNK) and phosphorylated p38 (p-p38) in lung tissues.Western blotting was conducted to determine the expressions of p-ERK,p-JNK and p-p38 in lung tissue.The activity of γ-GCS was measured by coupled enzyme assay.RESULTS: (1) The total cell number and number of eosinophils in BALF of asthmatic group were significantly higher than those in control group (P<0.01).(2) Immunohistochemistry indicated that the p-ERK,p-p38,p-JNK and γ-GCS were stronger expressed in asthmatic group than those in control group (P<0.01).Western blotting also discovered that the expressions of p-ERK,p-JNK and p-p38 in lung tissue of asthmatic group were stronger than those in control group.(3) Both in situ hybridization and RT-PCR analysis showed that the expression of γ-GCS-h mRNA was more positive in asthmatic group compared with control group (P <0.01).(4) The activity of γ-GCS of asthmatic group was significantly higher than that in control group (P<0.01).(5) Linear correlation analysis indicated that in lung tissue of guinea pig with asthma,p-ERK and p-p38 markedly positive correlated with γ-GCS-h mRAN and γ-GCS protein.No relationship between p-JNK and γ-GCS-h mRAN,γ-GCS protein was observed.CONCLUSION: The expressions of p-ERK,p-p38,p-JNK and γ-GCS increase in lung of guinea pigs with bronchial asthma.p-ERK and p-p38 may positively regulate the expression of γ-GCS.     

Immunomodulatory effect of Sema4D on Th1/Th2 in asthmatic rats induced by RSV and intervention of Kechuanning oral liquid

AIM To explore the effect of semaphorin 4D (Sema4D) on the immune regulation of Th1/Th2 in asthmatic rats induced by respiratory syncytial virus (RSV) and the effect of Kechuanning (KCN) intervention on the asthmatic rats. METHODS Healthy SPF female Wistar rats (n=100) were randomly divided into 10 groups: normal group, model group, Sema4D group, Sema4D antibody group, low, middle and high doses of KCN groups, and Sema4D+low, middle and high doses of KCN groups. Except the rats in normal group, the other rats were treated with RSV combined with ovalbumin (OVA) to induce asthmatic model. The pathological changes of the lung tissue were observed by HE staining, and the levels of interleukin-4 (IL-4), IL-6, IL-8, tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) in bronchoalveolar lavage fluid (BALF) were measured by ELISA. RESULTS Inflammatory cell infiltration and inflammatory damage in lung tissues of the rats in model group, Sema4D group and Sema4D+low dose of KCN group were observed by HE staining, while these pathological changes were attenuated in Sema4D antibody group, low, middle and high doses of KCN groups, and Sema4D+middle and high doses of KCN groups. Compared with normal group, the levels of IL-4, IL-6, IL-8 and TNF-α in BALF of the rats in the other groups were significantly increased, and the level of IFN-γ was significantly lowered (P<0.05 or P<0.01). Compared with model group, the levels of IL-4, IL-6, IL-8 and TNF-α in Sema4D group were increased, and the content of IFN-γ was decreased (P<0.05 or P<0.01). Compared with model group, the levels of IL-4, IL-6, IL-8 and TNF-α in Sema4D antibody group, low, middle and high doses of KCN groups, and Sema4D+low, middel and high doses of KCN groups were significantly decreased (P<0.01), while the content of IFN-γ was significantly increased (P<0.05 or P<0.01). No significant difference among Sema4D antibody group, Sema4D+middle and high doses of KCN groups, and low, middle and high doses of KCN groups was observed (P>0.05). CONCLUSION Sema4D causes Th1/Th2 immune imbalance and aggravates asthma. Inhibition of Sema4D reduces the production of inflammatory factors and regulates the balance of Th1/Th2. KCN may attenuate RSV-induced immune inflammation of asthmatic rats by inhibiting Sema4D, so as to achieve the anti-asthma effect.     

Effects of glucocorticoid on miRNA-155 expression in CD4+T cells of asthmatic mice

AIM:To investigate the effects of glucocorticoid on the regulation of microRNA-155 (miRNA-155) expression in the CD4⁺ T cells of asthmatic mice. METHODS:The ovalbumin (OVA)-induced asthma mouse model was established and the mice were treated with glucocorticoid. The effects of glucocorticoid on the pulmpnary histopathological changes, the expression of miRNA-155 in the lung tissues and CD4⁺T cells, and the levels of cytokines in the bronchoal-veolar lavage fluid (BALF) were evaluated. RESULTS:The results of RT-qPCR showed that the expressions of miRNA-155 in the lung tissues and CD4⁺T cells from the spleen of asthmatic mice were significantly increased, and the level of miRNA-155 in the CD4⁺T cells was significantly increased with the increase in the allergen exposure time (P<0.01). HE and PAS staining showed that OVA significantly increased inflammatory cell infiltration as compared with control group, and the peribronchial and perivascular inflammation and mucus secretion of proliferative goblet cells were significantly reduced after glucocorticoid treatment. Glucocorticoid treatment inhibited the increase in the proportion of CD4⁺ CD8^- cells in the spleen and decreased the accumulation of CD4⁺ T cells in the lung tissues of asthmatic mice (P<0.01). After glucocorticoid treatment, the levels of interleukin-4 (IL-4), IL-5 and IL-13 in BALF were decreased, while the level of interferon-γ was increased significantly (P<0.01). CONCLUSION:Glucocorticoid reduces the accumulation of CD4⁺ T cells and inhibits the expression of miRNA-155 in the lung tissues and spleen CD4⁺ T cells of asthmatic mice.     

Roles of ERK pathway and Panax notoginoside treatment in hypoxic hypercapnia pulmonary hypertension in rats

AIM: To investigate the roles of Panax notoginoside (PNS) and ERK1/2 signaling pathway in the pathological process of chronic hypoxic hypercapnia pulmonary hypertension in rats.METHODS: The animal model of chronic hypoxic hypercapnia pulmonary hypertension was set up in 72 male Sprague-Dawley rats and the animals were randomly divided into 6 groups: normal (N) group, hypoxic hypercapnia for 3-day (H_3d) group, hypoxic hypercapnia for 1-week (H_1w) group, hypoxic hypercapnia for 2-week (H_2w) group, hypoxic hypercapnia for 4-week (H_4w) group and PNS treatment (H_p) group.The rats in H_p group were injected with PNS (50 mg·kg^-1·d^-1, ip) before placing the animals into the hypoxic hypercapnia chamber.The rats in other groups were injected with normal saline (2 mL/kg, ip).The morphological changes of the pulmonary artery were observed under microscope with HE staining.Western blotting was used to detect the protein expression of p-ERK.The protein levels of p-ERK in the lung tissues and pulmonary blood vessels were determined by immunohistochemistry.RESULTS: The ratios of WA/TA in H_1w, H_2w, H_4w and H_p groups were higher than that in N group (P<0.05).The ratio of WA/TA in H_p group was obviously lower than that in H_4w group (P<0.05).The protein expression of p-ERK was barely positive in N group, but was up-regulated in the pulmonary tissues in all hypoxic rats.Compared with N group, the protein level of p-ERK was markedly up-regulated in H_3d group, reached its peak in H_2w group, and tended to decline in H_4w group (P<0.05).In pulmonary arterial tunica intima and tunica media, p-ERK protein was dramatically expressed in all hypoxic rats compared with the control animals (P<0.05).In the lung tissues, the protein level of p-ERK in H_p group was lower than that in H_4w group (P<0.05).In pulmonary arterial tunica intima and tunica media, the protein level of p-ERK in H_p group was lower by 84.86% than that in H_4w group (P<0.05).CONCLUSION: ERK1/2 as a signal transducer may play an important role in the development of hypoxia and hypercapnia induced pulmonary hypertension.PNS inhibits the expression of ERK1/2, thus attenuating the development of pulmonary hypertension and improving pulmonary vascular remodeling.     

Effects of PFOA exposure on inflammatory mediators IL-4, IFN-γ and glucocorticoid receptor in asthmatic mice

AIM: To investigate the effects of perfluorooctanoic acid (PFOA) exposure on the changes of asthmatic mouse airway inflammation, inflammatory mediators interleukin-4 (IL-4) and interferon-γ (IFN-γ) in serum, and glucocorticoid receptor (GR) expression in the lung tissue.METHODS: BALB/c mice (n=30) were randomly divided into 5 groups:normal control (C) group, asthma (A) group, asthma+low-dose PFOA (AP10) group, asthma+ mode-rate-dose PFOA (AP50) group and asthma+high-dose PFOA (AP100) group. Asthma model and PFOA exposure model of mice were established according to the grouping. The animals were sacrificed and their lungs were collected for HE staining, transmission electron microscopy, Western blot and immunohistochemical staining. ELISA was applied to detect the levels of IL-4 and IFN-γ in the serum.RESULTS: HE staining of the lungs showed that the asthmatic mice, compared with the normal control mice, had obvious mucus secretion around the airways and infiltration of inflammatory cells around airways and blood vessels, and the effects were much more marked in AP groups. Ultrastructural alteration of the lung tissues in the asthmatic mice were indicated by transmission electron microscopy. Compared with C group, the results of ELISA in A group and AP groups proved that IL-4 in the serum was increased and IFN-γ was decreased significantly (P<0.05). Compare with A group, IL-4 was significantly increased and IFN-γ was decreased in AP100 group (P<0.05), and no difference of those between AP10 group and AP50 group was found. The results of Western blot indicated that GR protein expression in the asthmatic mice were decreased compare with the normal mice (P<0.05), and no difference of that among A group and AP groups was observed. Immunohistochemical staining manifested that GR protein was mainly located in the cytoplasm of bronchial columnar epithelial cells, airway smooth muscle cells and vascular smooth muscle cells.CONCLUSION: Acute airway PFOA exposure in asthmatic mice dose-dependently exacebates lung inflammation by inducing Th2 type immune responses, promotes infiltration of inflammatory cells and mucus secretion around the airways and blood vessels, and destroys the ultrastructure of the lung tissues.     

Effect of Yangyu Tuji on content of type Ⅰ, Ⅲ collagen and the expression of MMPs and TIMP-1 in wound caused by streptozotocin in rats

AIM: To study the effects of Yangyu Tuji (YYTJ) on delayed healing wound of diabetic rats caused by streptozotocin (STZ). METHODS: SD male rats were randomly divided into control group (control), model group (model); and 3 different dose groups of YYTJ. 55 mg/kg STZ were given by intraperitoneal injection except for control group. After 30 days, a round skin of 1.6 cm diametre was excised on all dorsal back of rats. The healing time and healing rate were observed according to re-epithelization. The content of collagenⅠ and Ⅲ was observed by Picric acid-Sirius red staining , Matrix metalloproteinase-1, 13 (MMP-1, -13), tissue inhibitor of metalloproteinases-1 (TIMP-1) by immuno-histochemistry assay. All data were analyzed by IPP software. RESULTS: The healing time in each group treated with YYTJ was shorter than that in model group (P<0.01), and the healing rate was increased (P<0.01, P<0.05). Content of type I collagen, ratio of type Ⅰ and Ⅲ collagen of high and mid dose group were significantly higher than that in model group (P<0.01) at 3rd, 7th, 11th day. The expression of MMP-1, -13 of each groups were higher than that in model group at 7th day (P<0.01, P<0.05), and MMP-1 trend to equal with model group at 11th day. MMP-13 was significantly lower than that in model group at 11th day (P<0.01, P<0.05). TIMP-1 of each group of wound was higher than that in model group at 3rd, 7th, 11th day (P<0.01, P<0.05). The ratio of type Ⅰ and Ⅲ collagens in each group was lower than that in model group at 11th day (P<0.01). Ratio of MMP-13 and TIMP-1 of high dose group and mid dose group were higher than that in model group at 3rd and 7th day (P<0.01). The ratio of each group was lower than that in model group at 11th day (P<0.01). Meanwhile, ratio of MMP-13 and TIMP-1 of high dose group and mid dose group were lower than that of lower dose group (P<0.05). CONCLUSION: It is possible that YYTJ accelerates wound healing by increasing collagen content of type Ⅰ and Ⅲ, especially type Ⅰ, as well as improves collagen deposition by regulating the balance of MMP and TIMP.     

EGFR-p38 MAPK signaling pathway is involved in expression of HMGB1 in pulmonary tissues of rats with ventilator-induced lung injury

AIM: To investigate the role of epidermal growth factor receptor (EGFR)-p38 mitogen-activated protein kinase (MAPK) pathway in the expression of high mobility group box 1 protein (HMGB1) in the lung tissues of rats with ventilator-induced lung injury (VILI).METHODS: Thirty-two healthy Sprague-Dawley (SD) rats were randomly divided into 4 groups (n=8 each): group A, spontaneous breathing; group B, small tidal volume ventilation (VT=8 mL/kg); group C, high tidal volume ventilation (VT=40 mL/kg); group D, high tidal volume ventilation plus EGFR antagonist AG-1478. The rats in group B, group C and group D were mechanically ventilated for 4 h and then all animals were sacrificed.Total protein content and white blood cell (WBC) count in bronchoalveolar lavage fluid (BALF), the lung wet/dry weight ratio (W/D) and myeloperoxidase (MPO) activity were determined. The histological changes of lung tissues were observed by HE staining. The EGFR protein and mRNA expression, p38 MAPK activity and HMGB1 protein expression in the lung tissues were also detected.RESULTS: The inflammatory responses as evidenced by lung HE staining, total protein and WBC in BALF, the lung W/D and MPO activity were significantly higher in group C than those in group A (P<0.05). The mRNA expression of EGFR, EGFR activity, p38 activity and HMGB1 protein level also significantly increased in group C (P<0.05) as compared with group A. Significant decreases in the above indexes in group D were observed as compared with group C.CONCLUSION: High tidal volume ventilation induces acute lung injury, which may be related to up-regulation of HMGB1 expression through EGFR-p38 MAPK signal pathway.     

Yiqi-Yangyin recipe attenuates myocardial ischemia-reperfusion injury in diabetic rats by activation of ERK/Nrf2/HO-1 pathway

AIM: To explore the effect of Yiqi-Yangyin recipe on myocardial ischemia-reperfusion injury (MIRI) in rats with diabetes mellitus (DM) and the possible mechanism. METHODS: The rats were divided into normal group (control group), DM sham operation (DM-S) group, DM+MIRI group, low-, medium-and high-dose Yiqi-Yang-yin recipe (TL, TM and TH) groups (7.5, 15 and 30 g/kg decoction of Yiqi-Yangyin recipe by gavage), and Nrf2 inhibitor (bardoxolone methyl) group (30 mg/kg bardoxolone methyl by intragastric administration). The gavage volume was 1 mL/kg. There were 15 rats in each group, and they were administered continuously for 7 d. The tail vein blood was collec-ted after the last administration to detect the blood sugar and lipid levels in the rats. The serum levels of cardiac troponin I (cTnI), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-10 were measured by ELISA. Echocardiography was used to detect the changes of cardiac function in the rats after blood collection. After cardiac function test, the rats were sacrificed to obtain cardiac tissues, and the volume changes of myocardial infarction were assessed by triphenylte-trazole chloride staining. The histopathological changes of myocardium was observed by HE staining. The cardiomyocyte apoptosis was determined by TUNEL assay. The protein levels of phosphorylated extracellular signal-regulated kinase (p-ERK), nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in the myocardium were determined by Western blot. The myocardial activity of superoxide dismutase (SOD) was measured by nitro blue tetrazolium method, the content of malondialdehyde (MDA) was tested by thiobarbituric acid method, and the production of reactive oxygen species (ROS) was analyzed by iron ion reduction method. RESULTS: Compared with control group, the levels of fasting blood glucose (FBG), total cholesterol (TC) and triglyceride (TG) in DM-S group and DM+MIRI group were significantly elevated, while the level of high-density lipoprotein cholesterol (HDL-C) was significantly lowered (P<0.05). Compared with DM-S group and DM+MIRI group, the levels of FBG, TC, TG in TL, TM, TH and bardoxolone methyl groups were significantly decreased, while HDL-C level was significantly increased (P<0.05). Compared with control group and DM-S group, heart rate (HR) and left ventricular end-diastolic pressure (LVEDP) were increased in DM+MIRI group, mean arterial pressure (MAP), left ventricular systolic pressure (LVSP) and left ventricular ejection fraction (LVEF) were decreased, serum levels of cTnI, TNF-α, IL-1β and IL-10 were increased, the myocardial infarction volume percentage was increased, the myocardial cell breakage and necrosis were increased, the myocardial cell apoptotic rate was increased, the protein levels of p-ERK1/2, Nrf2 and HO-1 were decreased, MDA and ROS levels were increased, and the activity of SOD was decreased (P<0.05). Compared with DM+MIRI group, HR and LVEDP were decreased in TL, TM, TH and bardoxolone methyl groups, MAP, LVSP and LVEF were increased, the serum levels of cTnI, TNF-α, IL-1β and IL-10 were decreased, the myocardial infarction volume percentage was decreased, myocardial cell breakage and necrosis were decreased, myocardial cell apoptotic rate was decreased, the protein levels of p-ERK1/2, Nrf2 and HO-1 were increased, the MDA and ROS levels were decreased, and the activity of SOD was increased (P<0.05). CONCLUSION: Yiqi-Yangyin recipe protects the myocardial tissue of DM+MIRI rats from injury and reduces the oxidative stress level, which may be achieved by activating ERK/Nrf2/HO-1 pathway.     

Effects of endogenous nitric oxide on potassium channels of bronchial smooth muscle cells from asthmatic rats

AIM: To investigate the effects of in vivo application of L-arginine on potassium channels in bronchial smooth muscle cells (BSMC) isolated from asthmatic model rats. METHODS: Male SD rats were randomly divided into control group, asthmatic group and asthmatic rats treated with L-arginine (L-Arg group). Single BSMCs were obtained by acute enzyme separation method. The resting membrane potential (Em), Ca2+-activated K+ channels (BKCa) currents and voltage-dependent K+ channel (Kv) currents in BSMCs were recorded under whole-cell patch clamp technique. RESULTS: (1) The Em of asthmatic group was significantly lower than that in control group (P<0.05). In vivo application of L-Arg significantly hyperpolarized BSMCs near to control group (P>0.05). (2) The peak current density at +50 mV of KCa: IKca in asthmatic group ［(43.8±16.5) pA/pF］ was significantly lower than that in normal group ［(72.5±19.9) pA/pF］ (P<0.01). Treatment with 300 mg/kg L-Arg significantly increased IKca in asthmatic group to (58.7±12.4) pA/pF (P<0.05). (3) The peak currents density at +50 mV of Kv: IKv in asthmatic group ［(32.4±8.7) pA/pF］ was significantly lower than that in control group ［(57.7±9.8) pA/pF］ (P<0.01). Treatment with L-Arg also significantly increased IKv in asthmatic group to (43.6±7.9) pA/pF, (P<0.05). CONCLUSION: Endogenous NO improves Em in asthmatic BSMCs, increases the activities of BKCa channels and Kv channel. These findings implicate that NO may have a potential therapeutically role in airway hypersensitivity.     

Effect of dexamethasone on the adrenomedullin and its gene expression in lung tissue of asthmatic rats

AIM: To study the effect of dexamethasone (DEX) on the adrenomedullin (ADM) and its gene expression in lung tissue of asthmatic rats. METHODS: 30 healthy male SD rats were randomly divided into three groups (10 for each). The asthmatic model was established by ovalbumin inhalation and injection. The mRNA expression of ADM was examined by RT-PCR and the protein expression was detected by immunohistochemical method. The airway wall thickness, the airway smooth muscle (ASM) thickness and pulmonary tissue changes were observed under light microscope. RESULTS: The expression of ADM mRNA and protein in the asthma group A were higher than those in the control group(group C) (P<0.05), indicating that the moderate expression of ADM in asthmatic rat lung tissue is compensatory. The expression was significantly higher in DEX group (group B) than that in group A (P<0.01), indicating that DEX stimulated the expression of ADM mRNA and protein in lung tissue of asthmatic rats. CONCLUSION: The remarkable expression of ADM after the therapy of dexamethasone is one of its therapeutic mechanisms.     

Vinpocetine injection attenuates lipopolysaccharide-induced acute lung injury in rats

AIM:To observe the inhibitory effects of vinpocetine injection on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in the rats and to explore the underlying mechanisms.METHODS:Male Wistar rats (n=50) were randomly divided into 5 groups:control group,ALI model group,and low,medium and high doses of vinpocetine treatment groups.The rats in control group were injected with 0.9% NaCl at 5 mL/kg through femoral vein.The rats in ALI model group received LPS at 10 mg/kg through femoral vein.After injected with LPS,the rats in vinpocetine treatment groups received vinpocetine at 0.2 mg/kg,0.7 mg/kg or 1.2 mg/kg via intraperitoneal injection.The pathological changes of the lung tissues were observed under microscope with HE staining.The cell apoptosis in the lung tissues was detected by TUNEL staining.Myeloperoxidase (MPO) activity was measured by the method of spectrophotometry.The protein expression of NF-κB,ICAM-1,VCAM-1,Bax and Bcl-2 was determined by Western blot.RESULTS:Compared with ALI group,administration of vinpocetine significantly attenuated the structural injury of the lung and the infiltration of inflammatory cells.Moreover,vinpocetine decreased cell apoptosis and MPO activity in the lung tissues of ALI rats.In addition,the protein expression of NF-κB,ICAM-1,VCAM-1 and Bax was inhibited after vinpocetin treatment,whereas Bcl-2 expression was increased.CONCLUSION:Vinpocetine attenuates LPS-lung injury by reducing MPO activity and regulating NF-κB,ICAM-1,VCAM-1,Bax and Bcl-2 protein expression.     

Role of cyclin D1 in PKC regulating the proliferation of airway smooth muscle cells in asthmatic rat

AIM: To observe the expression of cyclin D1 following PKC activation and the correlation between PKC-α and cyclin D1 in asthmatic rat airway smooth muscle cells (ASMCs), and to discuss the effects of cyclin D1 on the proliferation of airway smooth muscle cells regulated by PKC in asthmatic rat. METHODS: Twelve SD rats were randomly divided into control group (group N) and asthmatic 2-week group (group A), and then subdivided into 4 groups based on the drug interventions: (1) control group; (2) PMA; (3) PMA+5 μmol/L Ro-31-8220 group; (4) 5 μmol/L Ro-31-8220 group. The proliferations of ASMCss were examined with cell cycle analysis, MTT colorimetric assay and proliferating cell nuclear antigen (PCNA) immunocytochemical staining. The expressions of PKC-α and cyclin D1 were analyzed by RT-PCR and Western blotting. The data were subject to correlation analysis. RESULTS: (1) Compared to group A1, there were significant differences in the percentage of S+G2/M phase, absorbance A value of MTT and the rate of positive expression of PCNA protein in group A2 and A4 (P<0.01). The same tendency in group N was observed according with group A. (2) Compared with A1, the ratios of A values of PKC-α mRNA and protein in group A2 and A4 were significantly changed (P<0.01) as well as the ratios of A values of cyclin D1 mRNA and protein. (3) There were positive correlations between PKC-α and cyclin D1 in mRNA (r=0.476, P<0.05) and protein(r=0.899, P<0.01). CONCLUSION: The activation of PKC-α promotes ASMCs proliferation in asthmatic rats, and there are positive correlations between the PKC-α and cyclin D1 in mRNA and protein, indicating that the PKC-α signal pathway may be involved in the process of airway smooth muscle remodeling by regulating the expression of cyclin D1 in asthmatic rats.     

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.     

Role of ERK on proliferation of airway smooth muscle cells in chronic asthmatic rats

AIM: To investigate the roles of extracellular signal-regulated kinase(ERK) signaling pathway on regulating proliferation of airway smooth muscle by observing the expression of ERK in airway smooth muscle(ASM) in chronic asthmatic rats.METHODS: Airway remodeling was detected in chronic asthmatic rats by using image analysis system. The expressions of ERK and proliferating cell nuclear antigen(PCNA) in lung tissue from chronic asthmatic rats were observed by immuocytochemistry staining. The expressions of ERK1/2, p ERK1/2 and PCNA were detected in airway smooth muscle (ASM) by immunofluorescence double staining with confocal microscopy, and the expressions of protein or mRNA of ERK and PCNA in ASM were also detected by immunoblotting and hybridization in situ,respectively.RESULTS: The thickening of smooth muscle and structural remodeling in airway were observed in chronic asthmatic rats by image analysis. The enhanced expressions of ERK and PCNA appeared obviously increased in same lung tissue and the expressions of protein or mRNA of ERK and PCNA were significantly increased in ASM.CONCLUSION: ERK signal pathway might be an important pathway on regulating cell proliferation of ASM resulting in asthmatic airway remodeling.     

Effect of Tripterygium hypoglaucum Hutch on MMP-13 protein expression and IL-12, IL-23 and IL-37 levels in serum and foot paws of rats with collagen-induced arthritis

AIM: To investigate the effect of tripterygium hypoglaucum Hutch (THH) on collagen-induced arthritis (CIA) in rats and its possible mechanism. METHODS: SD rats were randomly divided into normal group and CIA group. The rat model of type Ⅱ CIA was successfully established and the model rats were randomly divided into 4 different groups: model group, dexamethasone group, THH (200 mg/kg) group, and THH (400 mg/kg) group. The contents of IL-12, IL-23 and IL-37 in the serum and foot paws of the CIA rats were detected by ELISA. The histopathological changes of the skin of the food paws were observed by HE staining. The protein expression of MMP-13 was determined by Western blot. The MMP-13 activity in the foot paws was detected by fluorescence labeling method. RESULTS: Compared with CIA group, THH at dose of 400 mg/kg significantly reduced the weight loss in type Ⅱ CIA rats (P<0.01). THH at dose of 400 mg/kg obviously decreased the contents of IL-12 by 28.31%, IL-23 by 41.57% in the serum and IL-12 by 30.78%, IL-23 by 39.46% in the foot paws, while IL-37 was significantly increased by 79.43% in the serum and 75.78% in the foot paws (P<0.01). The pathological changes of the subcutaneous tissues were improved by treating with THH (400 mg/kg). The protein expression of MMP-13 was significantly decreased by 31.82% (P<0.01), and the MMP-13 activity was also reduced. THH at dose of 200 mg/kg had no obvious improvement on the above indexes. CONCLUSION: THH has significant inhibitory effect on rat CIA by reducing the content of proinflammatory cytokines IL-12 and IL-23, increasing the content of anti-inflammatory factor IL-37, inhibiting inflammatory cell infiltration and vascular proliferation, and attenuating the protein expression of MMP-13 and MMP-13 activity in rats.