Relationship between matrix metalloproteinase-9 and tissue metalloproteinase inhibitor-1 and carotid atheromatous plaque stability

AIM: To investigate the correlation between matrix metalloproteinase-9 (MMP-9),tissue metalloproteinase inhibitor-1 (TIMP-1),MMP-9/TIMP-1 and carotid atheromatous plaque stability in cerebral infarction patients.METHODS: 80 patients with cerebral infarction were categorized as microemboli-negative group (n=70) and microemboli-positive group (n=10),20 normal human were served as control group.The MMP-9 and TIMP-1 levels in plasma were determined by mean of ELISA in 3 groups.RESULTS: The levels of MMP-9 and TIMP-1 in plasma were significantly higher in cerebral infarction patients than those in control group (P<0.01).The plasma MMP-9 content was positively correlated with TIMP-1 content (r=0.76，P<0.01).The ratio of MMP-9/TIMP-1 increased only in microemboli-positive patients (P<0.01).CONCLUSION: The results indicate that the plasma MMP-9 participates in pathophysiological process of cerebral infarction.The ratio of MMP-9/TIMP-1 shows a close relationship with carotid atheromatous plaque instability.     

Expression of MMP-2 and NF-κB in myocardium of mice with viral myocarditis

AIM: To observe the effects of TNF-α/nuclear factor-κB(NF-κB)/matrix metalloproteinase-2(MMP-2) pathway on the expression of MMP-2 in the mice with viral myocarditis. METHODS: Six-week-old inbred male mice were randomly assigned to control and myocarditis group. The mice in myocarditis group and control group were intraperitoneally inoculated with 0.1 mL 10^-5.69 TCID50/mL coxsackievirus B3 and vehicle (PBS), respectively. Ten mice were sacrificed at the 4th and 10th days after injection. The blood and heart specimens were harvested. The serum content of TNF-α was measured by ELISA. The myocardial levels of MMP-2, NF-κB p65 and IκBα were determined by Western blot. RESULTS: Compared with control group, the protein expression of MMP-2 and NF-κB p65 in the myocardium and the serum content of TNF-α were significantly increased in myocarditis group (P<0.05). The protein expression of IκBα was lower in myocarditis group than that in control group (P<0.05).CONCLUSION: TNF-α, NF-κB p65 and MMP-2 were higher in the mice with acute viral myocarditis. The increased expression of them might be involved in the pathogenesis of viral myocarditis.     

Expression of matrix metalloproteinase and tissue inhibitor of metalloproteinase in lung tissue of hypercapnia rat model

AIM: To study the expression of matrix metalloproteinase-9(MMP-9), matrix metalloproteinase-2(MMP-2) and the tissue inhibitor of metalloproteinase(TIMP-1) in the lung tissue of the hypercapnia rat.METHODS: Forty Wistar rats were randomly divided into a control group (group A, n=20) and hypercapnia group (group B, n=20). Group B received mix gas exposure (6% CO2, 21% O2, 72% N2) 7 h daily for 4 weeks. The parameters we would examine were as follow: arterial blood gas; the mean pulmonary artery pressure;MMP-2,MMP-9, TIMP-1, and NE activity in lung tissue. Masson pigmentation of elasticity fibre was analyzed by computer image analyzer. Histopathological changes of lung tissue were observed under light microscope. The protein expression of MMP (MMP-2, MMP-9) and TIMP (TIMP-1) in lung tissue were determined by immunocytochemistry.RESULTS: Decompensate respiratory acidosis (pH=7.20±0.04, PaCO2=7.84±0.15) developed in group B. The mean pulmonary artery pressure were similar between groups B and A (P>0.05). Tissue edema in the lung, endothelial cell damage of the small blood vessels, pulmonary micro thrombus formations and increased pulmonary capillary permeability were observed in group B. NE activity increased significantly (P<0.01). However, no significant change of MMP-2, MMP-9, TIMP-1 activity was found in group B and group A (P>0.05). There was significant decrease in the relative content of elasticity fibre in lung tissue in group B compared to group A (P<0.01). The expression of MMP-2 protein in the lung tissue of group B was lower than that in group A (P<0.01), but the expression of both MMP-9 and TIMP-1 proteins in the lung tissue in group B were higher than those in group A (P<0.01).CONCLUSION: Hypercapnia rat model is successfully reproduced by exposure of animals to the mix gas exposure (6% CO2, 21% O2, and 72% N2). The pulmonary artery pressure is not affected by hypercapnia. High concentration of CO2 causes increase of NE activity and decrease in the relative content of elasticity fibre. High concentration of CO2 causes the increase of MMP-2 protein expression and decrease in the MMP-9 and TIMP-1 protein expression.     

Effects of angiotensionⅡon metalloproteinases and matrix in hypertrophied myocardium from infarcted rats

AIM: To investigate the roles of angiotensionⅡ (AngⅡ) receptors (AT₁, AT₂) antagonists on matrix metalloproteinases (MMPs) and extracellular matrix (ECM) system in septal myocardium from infarcted rats.METHODS: The model of rat myocardium infarction (MI) was established by permanent ligation of the left coronary artery. The treatments of the AT₁ receptor antagonist valsartan (10 mg·kg^-1·d^-1) or AT₂ receptor antagonist PD123319 (30 mg·kg^-1·d^-1) were started 7 days prior to surgery. On day 14 after MI, protein levels of MMP-2, 3, 9, fibronectin (FN), tenascin-C (TN-C) in interventricular septum (IS) were determined. The distributions of FN and TN-C were also determined by immunofluorescence.RESULTS: Pathological changes of IS on day 14 after MI showed typical myocardial hypertrophy. Protein expressions of MMP-2, 3, 9 and TN-C of IS in banding group were higher than those in sham-operation group (P<0.01). The expressions of TIMP-1 and FN were lower than those in sham-operation group (P<0.01). Protein expressions of MMP-2, 3, 9 and TN-C in valsartan group were obviously lower than those in banding and PD123319 groups (P<0.01). TIMP-1 and FN protein expressions in valsartan group were higher than those in banding and PD123319 groups (P<0.01). No difference between banding and PD123319 groups was observed (P>0.05).CONCLUSION: AngⅡis involved in myocardium remodeling in infarcted rats, which is mediated via AT₁ receptor to degrade matrix by MMPs. The heart protection of AT₁ receptor antagonists may relate to inhibition of MMPs.     

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.     

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.     

Effects of chloroquine on autophagy and collagen metabolism in activated hepatic stellate cells in vitro

AIM: To explore the effects of chloroquine (CQ) on collagen Ⅰand collagen Ⅲ expression in activated rat hepatic stellate cell line HSC-T6 and the possible mechanism.METHODS: Transforming growth factor-β1 (TGF-β1) was used to activate HSC-T6 cells and 3 doses of CQ was administered for 24 h. The cells were divided into 5 groups as follows:control group, TGF-β1 group, TGF-β1+CQ (15 μmol/L) group, TGF-β1+CQ (30 μmol/L) group and TGF-β1 + CQ (60 μmol/L) group. Western blot was used to determine the expression of LC3-Ⅱ/LC3-I, P62 and α-SMA in activated HSC-T6 cells. The expression of collagen I and collagen Ⅲ was detected by immunocytochemical staining, Western blot and RT-qPCR. Western blot and RT-qPCR were also used to detect the expression of matrix metalloproteinase-13 (MMP-13), tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2 at mRNA and protein levels.RESULTS: The ratio of LC3-Ⅱ/LC3-Ⅰ and P62 expression were increased after CQ intervention. Moreover, they were significantly higher in the TGF-β1+CQ groups than those in TGF-β1 group (P<0.01). The expression of collagen I and collagen Ⅲ at mRNA and protein levels was significantly increased in all TGF-β1+CQ groups as compared with TGF-β1 group (P<0.01), and it was markedly increased among TGF-β1+CQ groups in a dose-dependent manner. The expression of MMP-13 at mRNA and protein levels was significantly lowered and that of TIMP-1 and TIMP-2 was significantly increased in TGF-β1+CQ groups as compared with TGF-β1 group (P<0.05).CONCLUSION: Inhibition of autophagy by CQ in activated HSC-T6 cells up-regulates the expression of collagen I and collagen Ⅲ in a dose-dependent way, probably due to reduction of MMP-13 and enhancement of TIMP-1 and TIMP-2 expression.     

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.     

Effect of Zhengtian pills on P2X3 receptor expression in trigeminal gan-glion of migraine rats

AIM: To explore the effect of Zhengtian pills on P2X₃ receptor expression in trigeminal ganglion (TG) of migraine rat. METHODS: Sprague-Dawley (SD) rats were randomly divided into control group, migraine group, Zhengtian pills (ZTP) group and A-317491 group. After given corresponding drugs for 7 d, migraine rat model was established by subcutaneously injection of nitroglycerin (10 mg/kg), while the control rats were injected with saline. The beha-vioral manifestations of the rats were observed. The expression of P2X₃ receptor in rat TG was detected by the methods of immunofluorescence, Western blot and rea-time PCR. RESULTS: About 5 min after subcutaneousl injection, the behavioral manifestations such as scratching head and climbing cage were observed. The behavioral manifestations were observed within the first 30 min in control group, but the erythroid ears did not appear. After 2 h of molding, the behavioral manifestations disappeared in ZTP group and A-317491 group, while those in migraine group lasted for 3 h. Immunofluorescence results showed that the expression of P2X₃ receptor in TG was positive in each group. The expression level in migraine group was significantly higher than that in other groups. The P2X₃ receptor protein and mRNA levels in the TG of migraine group were higher than those in control group (P<0.01), while those in ZTP group were lower than those in migraine group (P<0.01). No difference of the P2X₃ receptor expression between ZTP group and A-317491 group was observed. CONCLUSION: Zhengtian pills may effectively alleviate migraine by inhibiting the expression of P2X₃ receptor in TG.     

Effects of Shenmai injection on myocardial fibrosis in rat model of diabe-tic cardiomyopathy

AIM：To explore the effects of Shenmai injection on myocardial fibrosis in a rat model of diabetic cardiomyopathy (DCM). METHODS：Wistar rats (n=30) were randomly divided into control group, diabetes group and treatment group. Single intraperitoneal injection of streptozotocin was utilized to establish a rat model of DCM. The rats with DCM in treatment group were intraperitoneally injected with Shenmai injection. Ventricular cannulation was applied to assess the cardiac functions. The formation of collagen in the cardiac tissues was assessed by Masson staining. The generation of reactive oxygen species (ROS) in the cardiac tissues was detected by dihydroethidium staining. The expression levels of matrix metalloproteinase 2 (MMP-2), tissue inhibitor of metalloproteinase 2 (TIMP-2) and collagen I in the cardiac tissues were determined by Western blotting. RESULTS：Compared with control group, the cardiac functions were deteriorated in diabetes group (P<0.05), which was improved in treatment group as compared with diabetes group (P<0.05). Compared with control group, the formation of collagen and ROS increased significantly in diabetes group (P<0.05), which was decreased in treatment group as compared with diabetes group (P<0.05). Compared with control group, the expression level of MMP-2 in the cardiac tissues was deceased and TIMP-2 was increased significantly in diabetes group (P<0.05), but reversed significantly in treatment group (P<0.05).CONCLUSION:Shenmai injection attenuates cardiac fibrosis in the rats with DCM by inhibiting the generation of ROS.     

Kinetics of pathologic changes in bleomycin-induced murine pulmonary fibrosis model

AIM: To Investigate the kinetics of pathologic changes in bleomycin-induced pulmonary fibrosis in rats. METHODS: Sixty male SD rats were randomized as a negative control group and pulmonary fibrosis model groups (B3, B7, B14, B28, B56 sub-groups). Except for control group, rats in the other groups were intratracheally administered with bleomycin. Animals in pulmonary fibrosis model groups were sacrificed on day 3, 7, 14, 28 and 56. The sections of the right lung were stained by HE, Masson and sirius red. The left lung was weighed and its hydroxyproline content was assayed. The mRNAs of TGF-β1, MMP-9 and TIMP-1 in the lung homogenate were measured by semi-quantitative RT-PCR. The expressions of TGF-β1, MMP-9 and TIMP-1 in lungs were observed by immunohistochemistry. RESULTS: (1) The content of lung hydroxyproline in pulmonary fibrosis model groups was significantly increased than that in control group (P<0.05). The pulmonary inflammation in pulmonary fibrosis model groups was significantly serious than that in control group, pulmonary fibrosis in B14, B28 and B56 groups was also significantly serious than that in control group. (2) A small quantity of TGF-β1, MMP-9 and TIMP-1mRNA were measured in normal lung, and the expression increased significantly after administration of bleomycin. Different expressions of TGF-β1, MMP-9 and TIMP-1 in different days after bleomycin administration were observed. CONCLUSION: The pathological changes in different days after bleomycin administration are different. TGF-β1, MMP-9 and TIMP-1 may play important roles in the pathogenesis of pulmonary fibrotic process.     

Effects of olaquindox on PLA2 activity and phospholipid metabolism of biomembrane in chicks

AIM: To study the effect of olaquindox on phospholipase A₂ (PLA₂) activity and phospholipid metabolism in biomembrane.METHODS: 150 healthy avin chicks were divided into normal control group and olquindox group.The two groups were fed with same feedstuff without olaquindox.The animals in olquindox group were fed with olquindox at dose of 15mg/kg body weight everyday.The experimental period lasted six weeks.Every week 6 vein blood samples were collected randomly from every group for preparing erythrocyte membrane (ECM) and hepatic mitochondria membrane (MiM).RESULTS: PLA₂ activities of ECM and MiM in olquindox group were significant higher than those in control group from 3 to 6 weeks of experiment (P<0.05，P<0.01).The level of major membrane phospholipids in olquindox group was lower than that in control group (P<0.05,P<0.01).CONCLUSION: Olaquindox affects PLA₂ activity and major phospholipid concentration in ECM and MiM,indicating that olaquindox may induce biomembrane injury.     

Effects of different ventilation strategies on gas exchange and extravascular lung water during early stage of acute lung injury in a canine model

AIM: To evaluate the effects of different ventilation strategies on gas exchange and extravascular lung water during early stage of acute lung injury (ALI). METHODS: Upon the establishment of oleic acid-induced ALI (diagnostic standard: PaO₂/FiO₂ ≤ 300 mmHg), 24 adult mongrel dogs were randomly divided into 3 groups (n=8 each) according to different ventilation strategies: controlling high-concentration oxygen therapy (O₂) group, continuous positive airway pressure (CPAP) group and bi-level positive airway pressure (BiPAP) group. The parameters of gas exchange and hemodynamics including the values of normal baseline, at ALI early stage (positive control) and from 1 to 4 h after treatment were recorded continuously. RESULTS: Compared with the value at the beginning of ALI, after 4 h of artificial ventilation, the improvement in oxygenation index (PaO₂/FiO₂) in BiPAP group (375.83±81.55, P<0.01) and CPAP group (327.17±78.82, P<0.01) were better than that in O₂ group (255.00±49.85, P>0.05). The ratio of alveolar dead space to tidal volume [V_D(alv)/V_T]in O₂ group further increased (P<0.01), while it obviously declined in CPAP group and BiPAP group (P<0.01). Oxygen delivery (DO₂) in BiPAP group (P<0.01) was much higher than that in CPAP group and O₂ group, while oxygen consumption (VO₂) and oxygen extraction rate (O₂ER) in O₂ group were evidently higher than those in CPAP group and BiPAP group (P<0.05, P<0.01). After treatment, the alveolar-arterial oxygen differences [P_(A-a)O₂] of the 3 ventilation groups were significantly higher than the normal baseline values and the values at early ALI stage (P<0.01). BiPAP and CPAP greatly reduced the ratio of shunted blood to total perfusion (Qs/Qt) as compared with O₂ group (P<0.01). Some parameters including pulmonary arterial wedge pressure (PAWP) and index of cardiac output (CI) kept stable, while mean pulmonary arterial pressure (MPAP) and pulmonary vascular resistance index (PVRI) further increased in CPAP group and BiPAP group (P<0.05,P<0.01). Three ventilation strategies did not effectively control the increase in extravascular lung water index (ELWI). CONCLUSION: During early stage of ALI, BiPAP and CPAP make active effects on improving gas exchange and tissue oxygenation. BiPAP displays more significant therapeutic effect than CPAP and oxygen therapy. The 3 ventilation strategies have no obvious effects on reducing extravascular lung water.     

Ulinastatin protects rat pulmonary tissues from paraquat-induced acute injury

AIM: To investigate the protective effects of ulinastatin on the rats with paraquat-induced acute lung injury and its mechanisms. METHODS: The Wistar rats (n=108) were randomly divided into control group, paraquat group and ulinastatin group. The rats in paraquat group and ulinastatin group were given paraquat by gavage, while the rats in control group were given sterile saline by gavage. The rats in ulinastatin group were also given ulinastatin treatment. The serum levels of MDA, SOD, IL-6, IL-10 and TNF-α were measured after 1 d, 3 d, 7 d, 14 d, 21 d and 28 d. The expression levels of p38 MAPK, MMP-2 and TIMP-1 in the lung were also measured. RESULTS: The levels of SOD in 1 d, 3 d and 7 d in paraquat group and ulinastatin group were significantly lower than those in control group (P<0.01). The level of SOD in ulinastatin group was significantly higher than that in paraquat group (P<0.05). The levels of MDA, IL-6, IL-10 and TNF-α in 1 d, 3 d and 7 d in paraquat group and ulinastatin group increased compared with control group (P<0.01), and those in ulinastatin group were significantly lower than those in paraquat group (P<0.05). The levels of p38 MAPK and TIMP-1 in 1 d, 3 d, 7 d, 14 d, 21 d and 28 d in paraquat group and ulinastatin group were higher than those in control group (P<0.01), and those in ulinastatin group was significantly lower than those in paraquat group (P<0.05). The level of MMP-2 in 1 d, 3 d, 7 d, 14 d and 21 d in paraquat group and ulinastatin group increased compared with control group (P<0.01), and that in ulinastatin group was significantly lower than that in paraquat group (P<0.05).CONCLUSION: Ulinastatin protects the lung tissues of rats from paraquat-induced acute lung injury by inhibiting p38 MAPK signaling pathway and ameliorating inflammatory and oxidative responses.     

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.     

Expression of MMP-2 mRNA and MMP-9 mRNA in pulmonary arterioles ofrats with pulmonary hypertension induced by chronic hypoxia hypercapnia

AIM:To investigate the expression of matrix metalloproteinases(MMPs) in pulmonary arterioles of rats with chronic hypoxia and hypercapnia-induced pulmonary hypertension.METHODS:MMP-2, MMP-9 and MMP-2 mRNA, MMP-9 mRNA were observed in pulmonary arterioles by the techniques of immunohistochemistry and in situ hybridization.RESULTS:①The mean pulmonary artery pressure (mPAP) and weight ratio of right ventricle to left ventricle and septum (RV/LV+S) of hypoxia-hypercapnia groups were higher than those of normal control group (P＜0.01). ②Light microscopy showed that vessel wall and media of pulmonary arterioles were thicker in rats of hypoxia-hypercapnia groups than normal control group. There were vessel smooth muscle cell hypertrophy, vessel cavity straitness in hypoxia-hypercapnia group, but no same performance was found in normal control group. ③The expression of MMP-2, MMP-9 and MMP-2 mRNA, MMP-9 mRNA in pulmonary arterioles were significantly higher in rats of hypoxia-hypercapnia groups than control group (P＜0.01).CONCLUSION:Expression of matrix metalloproteinases in pulmonary arterioles is enhanced by hypoxia hypercapnia. This may be involved in pulmonary vascular remodeling in rats with pulmonary hypertension.