ObjectiveTo observe the effect of metformin on airway remodeling in asthma and its possible mechanism.MethodsTwenty-eight B/N rats were randomly divided into control group, asthma group, metformin intervention group and rapamycin intervention group. After that, the asthma model was established and intervened with metformin and rapamycin. The airway resistance and airway reactivity were measured 48 hours after the last challenge, and then the lung tissue samples were collected. Histopathological examination was used to observe airway inflammatory cell infiltration, goblet cell proliferation, airway wall fibrosis and remodeling, as well as airway smooth muscle proliferation. The expression of AMPK/mTOR pathway related proteins was detected by Western blot.ResultsCompared with the asthma group, metformin and rapamycin significantly reduced the airway responsiveness induced by high concentration of acetylcholine (P<0.05), reduced the infiltration of inflammatory cells in lung tissue and the changes of airway wall structure (P<0.05), reduced goblet cell proliferation in airway epithelium, collagen fiber deposition in lung tissue and bronchial smooth muscle hyperplasia (P<0.05). Further studies showed that the effects of metformin and rapamycin were related to AMPK/mTOR pathway. Compared with the asthma group, metformin and rapamycin could significantly reduce the expression of p-mTOR, p-p70s6k1 and SKP2, while p21 protein expression was significantly increased (P<0.05). In addition, metformin and rapamycin had similar effects (P>0.05).ConclusionMetformin can alleviate airway hyperresponsiveness and airway remodeling by activating AMPK and then inhibiting mTOR pathway, which may be a potential drug for treating asthma and preventing airway remodeling.
Objective To investigate the incidence and management of CTEPH in the Department of Pulmonary and Critical Care Medicine in Xijing Hospital to enrich the epidemiological data of chronic thromboembolic pulmonary hypertension (CTEPH) in China.Methods We conducted a retrospective study to investigate the incidence and management of CTEPH in the Department of Pulmonary and Critical Care Medicine in Xijing Hospital from 2008 to 2012. Results The incidence of CTEPH was 5.24% . About 62.90% of venous thromboembolism/pulmonary embolism (VTE/PE) patients were unprovoked, and about 53.85% of CTEPH patients was unprovoked. About 38% of CTEPH patients had no history of VTE, and 62% of CTEPH patients had no history of acute pulmonary embolism. None of the CTEPH patients was treated by pulmonary thromboendarterctom (PTE) , and about 53.85% of patients were only given anticoagulant monotherapy. Conclusions The incidence of CTEPH is higher in our hospital than reported. This phenomenon may be related to the lack of awareness of risk factors of CTEPH and the insufficient thrombolytic and anticoagulant therapy to acute pulmonary embolism. It’s very urgent to standardize the diagnosis and management of CTEPH in pulmonologists.