| Objective Notch is a signal-pass transmembrane receptor protein by lymphocyte, macrophage, dendritic cell and histocyte. y-Secretase inhibitor (GSI) acts as an effective blocker of Notch signaling. In this study, by observing the influence Notchl receptor and its downstream target genes Hesl in chronic obstructive pulmonary disease (COPD) on alveolar macrophage (AM), and the cytokines IL-6, TNF-a to explose the role of Notch signaling pathways in inflammation in COPD.Methods 80 male BALB/c mice were randomly divided into healthy control group, healthy GSI intervened group, COPD control group, and COPD GSI intervened group. COPD mice were exposed to cigarette smoke. The relative quantity of Notchl mRNA, Hesl mRNA for alveolar macrophage were tried out by real time-polymerase chain reaction (RT-PCR). Notchl and its downstream Hesl protein expression were tried out by Western blot. The IL-6, TNF-a in blood serum and bronchial alveolar lavage fluid (BALF), were analyzed by enzyme linked immunosorbent assay (ELISA).Result (1) After exposure to cigarette smoke,the pulmonary function of PIF and PEF in the mice of COPD group (6.82±0.46) ml/s, (3.87±0.44) ml/s were significantly lower than those in healthy control group (9.84±0.46) ml/s, (7.96±0.52) ml/s, (P<0.01,0.05). Significant small airway inflammation and emphysema were seen in the lung tissue of COPD group.(2)The AM surface Notchl and its downstream Hesl mRNA expression. As to healthy control group (0.64±0.16) and healthy GSI intervened group (0.55±0.28), the relative quantity of Notchl mRNA for alveolar macrophage in COPD group(1.45±0.16) was increased, the differences were statistically significant(P< 0.01). As to COPD group, the relative quantity of Notchl mRNA in COPD GSI intervened group (0.72±0.37) was decreased, the differences were statistically significant (P<0.05). As to healthy control groups (1.03±0.26) and healthy GSI intervened group (1.14±0.27), the relative quantity of Hesl mRNA for alveolar macrophage in COPD group (2.24±0.33) was increased, the differences were statistically significant(P<0.01). As to COPD group, the relative quantity of Hesl mRNA in COPD GSI intervened group (1.24±0.32) was decreased, the differences were statistically significant(P<0.01).(3) The AM surface Notch1 and its downstream Hesl protein expression. As to healthy control groups (1.05±0.07) and healthy GSI intervened group (1.09±0.04), the expression of Notchl protein for alveolar macrophage in COPD group (1.96±0.07) was increased, the differences were statistically significant (P<0.01). As to COPD group, the expression of Notchl protein in COPD GSI intervened group (1.13±0.03) was decreased, the differences were statistically significant (P<0.01). As to healthy control groups (0.93±0.06) and healthy GSI intervened group (0.90±0.06), the expression of Hesl protein for alveolar macrophage in COPD group (1.30±0.02) was increased, the differences were statistically significant (P<0.01). As to COPD group, the expression of Hesl protein in COPD GSI intervened group (1.11±0.04) was decreased, the differences were statistically significant (P<0.05).(4)The level of IL-6, TNF-a in BALF or blood serum. ①COPD group, COPD GSI intervened group [(81.84±2.06,58.36±1.90) pg/ml] compared with healthy control group and healthy GSI intervened group [(30.82±2.01,29.24±1.40) pg/ml], the IL-6 in BALF was significantly increase,the differences were statistically significant (P<0.01). COPD GSI intervened compared with COPD group,the IL-6 in BALF was significantly decrease, the differences were statistically significant (P< 0.01). COPD group, COPD GSI intervened group [(98.36±2.18,67.23±2.40) pg/ml] compared with healthy control group and healthy GSI intervened group [(39.08±1.81,37.94±3.12) pg/ml], the IL-6 in blood serum was significantly increase,the differences were statistically significant (P<0.01). COPD GSI intervened compared with COPD group,the IL-6 in blood serum was significantly decrease, the differences were statistically significant (P<0.01). COPD group, COPD GSI intervened group [(63.04±3.84、43.86±2.63) pg/ml] compared with healthy control group and healthy GSI intervened group [(24.84±1.56、23.71±1.79) pg/ml], the TNF-a in BALF was significantly increase, the differences were statistically significant(P<0.01). COPD GSI intervened compared with COPD group, the TNF-a in BALF was significantly decrease, the differences were statistically significant (P<0.01). COPD group, COPD GSI intervened group [(69.35±2.94、 52.77±2.66) pg/ml] compared with healthy control group and healthy GSI intervened group [(20.38±1.93、19.69±1.43) pg/ml], the TNF-a in blood serum was significantly increase,the differences were statistically significant (P<0.01). COPD GSI intervened group compared with COPD group,the TNF-a in blood serum was significantly decrease, the differences were statistically significant (P<0.01)(5) Correlation analysis:①For the COPD group:the AM’s Notchl mRNA expression was positively correlated with IL-6 of BALF and blood serum(r=0.850, 0.871, all P<0.01). Notchl protein expression was positively correlated with IL-6 of BALF and blood serum(r=0.819,0.874, all P<0.01). For the COPD group:the AM’s Hesl mRNA expression was positively correlated with IL-6 of BALF and blood serum(r=0.948,0.825, all P<0.01). Hesl protein expression was positively correlated with IL-6 of BALF and blood serum(r=0.726,0.814, P<0.05,0.01). ②For the COPD group:the AM’s Notchl mRNA expression was positively correlated with TNF-a of BALF and blood serum(r=0.872,0.828, all P<0.01). Notchl protein expression was positively correlated with TNF-a of BALF and blood serum(r=0.847, 0.928, all P<0.01). For the COPD group:the AM’s Hesl mRNA expression was positively correlated with TNF-a of BALF and blood serum(r=0.855,0.877, all P< 0.01). Hes 1 protein expression was positively correlated with TNF-a of BALF and blood serum(r=0.714,0.801, P<0.05,0.01).③ For the COPD GSI intervened group: the AM’s Notchl mRNA expression was positively correlated with IL-6 of BALF and blood serum(r=0.819,0.879, all P<0.01). Notchl protein expression was positively correlated with IL-6 of BALF and blood serum(r=0.919,0.786, all P<0.01). For the COPD GSI intervened group:the AM’s Hesl mRNA expression was positively correlated with IL-6 of BALF and blood serum(r=0.805,0.887, all P<0.01). Hes1 protein expression was positively correlated with IL-6 of BALF and blood serum(r=0.910,0.905, all P<0.01). ④For the COPD GSI intervened group:the AM’s Notchl mRNA expression was positively correlated with TNF-a of BALF and blood serum(r=0.723,0.708, all P<0.05). Notchl protein expression was positively correlated with TNF-a of BALF and blood serum(r=0.795,0.814, all P<0.01). For the COPD GSI intervened group:the AM’s Hesl mRNA expression was positively correlated with TNF-a of BALF and blood serum(r=0.764,0.707, all P<0.01). Hes 1 protein expression was positively correlated with TNF-aof BALF and blood serum(r=0.801,0.744, P<0.01,0.05).Conclusion Exposed to cigarette smoke can be successfully established the model of COPD mice. Notch signaling pathway involved in the pathogenesis of COPD. Notch1/Hes1 and its downstream cells cytokine levels was partially inhibited by GSI, Notch signaling pathway may control AM participate in inflammatory response of COPD. |
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