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Objective To study any change in the expression of γ-glutamylcysteine synthetase (γ-GCS) in the skeletal muscles of mice with emphysema.MethodsTwenty Kunming male mice were divided into a normal control group and an emphysema group (n =10 in each ).An emphysema model was established by passive cigarette smoking in 8 of the emphysema group mice.TUNEL staining was used to detect apoptotic skeletal muscle cells.Im munohistochemical assays were used to determine the protein level of γ-GCS synthetase.ResultsThe average optical density of apoptotic cells was significantly higher in the skeletal muscles of the mice with emphysema compared with the normal controls,and their average γ-GCS synthetase levels were also significantly higher.Conclusions Apoptotic cells increase in skeletal muscle during emphysema,which may be caused by an oxidation/antioxidant imbalance mediated by γ-GCS synthetase.
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AIM: To explore the effects of peroxisome proliferator-activated receptor γ (PPARγ) on the activity and expression of γ-glutamylcysteine synthetase (γ-GCS), and its role in rats with chronic obstructive pulmonary disease. METHODS: COPD model was established by the method of combining fumigation and lipopolysaccharide (LPS) intra-tracheal dripping. Meanwhile, some of the COPD rats were administered with rosiglitazone (RGZ), a PPARγ activator. The pulmonary function and the pathological changes were determined. ROS content and γ-GCS activity in lung tissues were detected. The levels of PPARγ, γ-GCS mRNA and protein expression in lung tissues were measured by immunohistochemistry, Western blotting, in situ hybridization (ISH) and reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The pulmonary function (FEV_(0.3), FEV_(0.3)/FVC%, PEF) were significantly improved in RGZ group compared to COPD group. Under light microscope, lung pathological changes in COPD group conformed to pathological features of COPD. The pathological changes of lung tissue were obviously reduced in RGZ group compared to COPD group. In RGZ group, ROS content was obviously reduced and γ-GCS activity significantly increased compared to COPD group. Protein and mRNA expressions of PPARγ and γ-GCS in COPD group significantly higher than those in control group (all P<0.01), and those in RGZ group was markedly increased compared to COPD group (all P<0.05). Linear correlation analysis showed that PPARγ protein was positively correlated with γ-GCS activity (r=0.634, P<0.01), and was no significantly correlated with ROS content (r=0.214, P>0.05). PPARγ protein was positively correlated with γ-GCS protein and mRNA (r=0.553, r=0.442, all P<0.01). CONCLUSION: PPARγ activation by RGZ reduces the extent of COPD oxidant/antioxidant imbalance, which plays an important role in the prevention and treatment of COPD. In addition, PPARγ may play an important antioxidant protection role by reducing ROS production, and increasing activity and gene expression of γ-GCS in the lung.
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Objective To explore the influence of inhaled glucocorticosteroid on ?-glutamylcysteine synthetase(?-GCS) in inflammatory cell of sputum in children with asthma.Methods Twenty-two asthmatic children were divided into 2 groups according to treatment.The children who were treated by inhaled budesonide combined with salbutamol were due to group A and the others inhaling salbutamol only were due to group B,the healthy children were acted as healthy control group(group C).The glutation(GSH),total GSH and the activity of ?-GCS in sputum were measured respectively;Expression of ?-GCS in inflammatory cell of sputum were detected by immunohistochemistry;the expression of ?-GCS heavy chain(?-GCS-h) mRNA were detected by reverse transcriptase-polymerase chain reaction(RT-PCR).Results 1.The total GSH[(1.08?0.14) ?mol/L] and oxidized glutathione(GSSG)[(0.37?0.09) ?mol/L] were decreased in sputum of group A of post-treatment compared with pre-treatment(Pa
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AIM: To investigate atypical protein kinase C(aPKC), extracellular signal regulated kinnase (ERK) regulating NF-E2-related factor 2 (NRF2)-?-gutamylcysteine synthetase (?-GCS) and the effect on lung of rats with chronic obstructive pulmonary disease (COPD). METHODS: The rat COPD model was established by intratracheal instillation of lipopolysaccharide twice and exposure to cigarette smoke daily. The ?-GCS activity was measured. The expression of ?-GCS mRNA in lung tissue was examined by in situ hybridization (ISH) and reverse transcription-polymerase chain reaction (RT-PCR). The protein expressions of p-aPKC?/?, p-ERK, NRF2 and ?-GCS in lung tissue were detected by immunohistochemistry (IH) and Western blotting, respectively. RESULTS: (1) The ?-GCS activity was higher in COPD group than that in control group. (2) The expression of ?-GCS mRNA in the COPD group was stronger than that in control group. ISH showed that the ?-GCS mRNA was expressed in alveolar epithelium and bronchiolar smooth muscle cell in the COPD group. (3) The protein expressions of p-aPKC, p-ERK, NRF2, ?-GCS were significantly higher than those in control group. IH showed that p-aPKC, p-ERK, NRF2, ?-GCS proteins were expressed in alveolar and bronchiolar epithelium in the COPD group. (4) There was a positive correlation between NRF2 and ?-GCS. ?-GCS mRNA, p-aPKC?/?, p-ERK were also positively correlated with NRF2. CONCLUSION: By upregulating the signal transduction of NRF2-?-GCS, the ERK and aPKC?/? may play an important role in the mechanism of COPD formation.
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AIM: To investigate the effect of erythromycin on the level of transforming growth factor-?1(TGF-?1) and ?-glutaglutamylcysteine synthetase(?-GCS) in smoking rats,and to explore the antioxidate therapeutic role of erythromycin in chronic obstructive pulmonary disease.METHODS: Wistar rats were exposed to cigarettes smoking to establish the model.After passive smoking for 4 weeks,erythromycin intragastric intervention was administered continuously for 8 weeks.The expiratory airway resistance and lung compliance were assessed and the expression levels of TGF-?1 and ?-GCS proteins(and the mRNA) in airway endothelial cells and alveolar macrophages were observed respectively by immunohistochemical,immunocytochemical and(in situ) hybridization.RESULTS: The expiratory airway resistance was increased and the lung compliance was degraded significantly in smoking group and erythromycin group,compared to control group.In erythromycin group,the airway resistance was lower and the lung compliance was higher than that in smoking group(P