Effect Of Simvastatin On Apoptosis In Chronic Obstructive Pulmonary Disease Rat Model

[Objective] To observe the effect of Simvastatin on apoptosis and apoptosis related factors endothelium nitric oxide synthase, inducible nitric oxide synthase and cysteine protease-3on chronic obstructive pulmonary disease rat model. Explore the effect of Simvastatin on COPD, so as to provide a theoretical basis for the use of Simvastatin in the treatment of COPD.[Methods]1.30health male Wistar rats were randomly divided into three group, the normal group (n=10), the control group (n=10) and the treatment group (n=10).2. The model of COPD was established by passive smoking and dripping lipopolysaccharide into the trachea, the treatment group was given Simvastatin (2.5mg/kg) by gastric lavage after two weeks modeling, and the Simvastatin treatment lasted for6weeks.3. The lung tissue pathology of the rat was observed by HE, and the apoptosis by terminal-deoxynucleoitidyltransferase mediated nick end labeling, to calculate apoptosis index, the expression of proteins and mRNA in eNOS, iNOS and Caspase-3was detected by reverse transcription PCR and immunohistochemistry.[Results]1. The pathology of the lung tissueThe normal group showed that tracheal mucosal ciliated columnar epithelial cells were full, it can be found the airway, blood vessels and alveoli were normal. It could be found in the control group obviously that the trachea and bronchial epithelium cilia was thicken, lodging, cilia adhesion, part of the airway epithelial cell fell off, glands hypertrophy, submucosa and muscularis infiltration of inflammatory cells, numerous inflammatory cells came out incircumvascular, capillary vessels congestion, the pulmonary alveoli structure was damaged, and the alveolar fused. It could also be found in the treatment group that the cast-off airway epithelial cell, the hyperplasia globet cells, and the infiltrated inflammatory cells were all less than the control group.2. Lung tissue morphologyCompared with the normal group, Mean linear intercept (MLI) in the control and treatment group increased (P<0.05), and Mean alveolar numbers (MAN) decreased (P<0.05); compared with the control group, MLI decreased(P<0.05)and MAN increased(P<0.05) in the treatment group.3. TUNEL detecting lung tissue cell apoptosisThe nucleus in apoptosis cells of the lung could be dyed from light brown to dark brown, the positive result could be found in alveolar epithelial cells, airway epitheliums, vascular endothelial cells, smooth muscule cells and some inflammatory cells. Compared with the normal, there could be more apoptosis of the alveolar epithelial and airway epithelium cells inthe control group and the treatment group (P<0.05); there were more apoptosis cells in the control than the treatment group (P<0.05)4. SP to detect the expression of lung tissueeNOS was mainly expressed in airway epithelial cells, alveolar epithelial cells and vascular endothelial cells. Compared with the normal group, the expression of eNOS was decreased (P<0.05) in the control and treatment group and the expression of eNOS was increased in the treatment group contrast to the control (P<0.05). iNOS was mainly expressed in alveolar epithelial cells, vascular endothelial cells and inflammatory cells. Compared with the normal group, the expression of iNOS was increased (P<0.05) in the control and treatment group, the expression of iNOS was decreased in treatment group contrast to the control (P<0.05). Caspase-3was expressed in alveolar epithelial cells, airway epithelial cells, vascular endothelial cells, blood vessels and airway smooth muscle cells. Compared with the normal group, the expression of Caspase-3increased (P<0.05) in the control and treatment group, the expression of Caspase-3was decreased in treatment group contrast to the control group (P<0.05).5. RT-PCR detects the expression of eNOS, iNOS and Caspase-3mRNACompared with the normal group, the expression of eNOS mRNA was decreased (P<0.05) in the control and treatment group, and iNOS, Caspase-3increased (P<0.05); the expression of eNOS mRNA was increased (P<0.05) and iNOS, Caspase-3decreased (P<0.05) in the treatment group compared with the control group.6. The correlation analysis of protein expression of Caspase-3, eNOS and iNOSIn the normal group, the expression of Caspase-3in the lung tissue correlated negatively with the eNOS (r=-0.86,P<0.05), and positively with the iNOS (r=0.80,P<0.05); In the control group, the expression of Caspase-3in the lung correlated negatively with the eNOS (r=-0.67,P<0.05), and positively with the iNOS (r=0.77,P<0.05); In the treatment group, the expression of Caspase-3in the lung correlated negatively with the eNOS (r=-0.85,P<0.05), and positively with the iNOS (r=0.88,P<0.05).7. The correlation analysis of mRNA expression of Caspase-3, iNOS and eNOSIn the normal group, the expression of Caspase-3mRNA in the lung correlated negatively with the eNOS mRNA (r=-0.86,P<0.05), and positively with the iNOS mRNA (r=0.94,P<0.05); In the control group, the expression of Caspase-3mRNA in the lung correlated negatively with the eNOS (r=-0.65,P<0.05), and positively with the iNOS (r=0.89,P<0.05); In the treatment group, the expression of Caspase-3mRNA in the lung correlated negatively with the eNOS (r=-0.92,P<0.05), and positively with the iNOS (r=0.90,P<0.05).[Conclusion]1. Simvastatin can ease the inflammation reactions of bronchial and airway peripheralvascular in COPD rat model.2. Simvastatin may ease the apoptosis of bronchus and lung tissue in COPD rats.3. Simvastatin can decrease the expression of Caspase-3by increasing the expression of eNOS and decreasing the expression of iNOS, consequently eases the apoptosis in COPD lung tissue, and plays a protective role in COPD, which can provide a theoretical basis for the Simvastatin treatment in COPD.