Research Of The Expression Of ERK1/2 And Beclin-1 Protein In Rat Model Of COPD Skeletal Muscle Atrophy

Objective:To investigate apoptosis of skeletal muscles dystrophy and the expression of ERK and Beclin-1 in chronic obstructive pulmonary diseases(COPD) model rat.Additionally, to research the effect of ERK and Beclin-1 in skeletal muscles myotrophy of COPD model rat.Method:one hundred healthy male Wistar rats were randomly divided into two groups:normal control group(n=20)and model group (n=80).The COPD model rats were established by having been exposed to cigarette smoke for 60 days,30 minutes per day and intratracheal instillation of pig pancreatic elastase (PEE)(20u/100pl) in 30th day.The control group rats were established by intratracheal instillation of the same dose normal saline in 30th day, without having been exposed to cigarette smoke.Then the COPD model rats were raised to the 90th day in order to make the average weight of control group as low as 90% of control group. It is the standards of malnutrition. Then being given the lung function testing, evaluation model, rats were divided into:control group, COPD group of the normal weight and COPD group of malnutrition. After all rats were sacrificed, the measures are as follows:1. Collect the samples of lung tissue and left extensor digitorum longus2. Measure the body weight and the weight of extensor digitorum longus3.Measure the Apoptosis of extensor digitorum longus by TUNEL In situ hybridization4.Measure the expression of skeletal muscle ERK, Beclin-1 protein by immunohistochemistry (ABC method)5. Use high-resolution digital camera Nikon DS to photograph by NIS-Elements AR 3.0 software. The images of Positive cells in Sections of skeletal muscle cells were collected through the photograph. All experimental results were acquired by digital image and analyzed in quantitative way with the help of Ver.3.00 software, and all obtained data were statistically processing, by the SPSS 13.0 software. Result:1.with the paraffin sections of lung tissue having been given HE staining, lung tissue Paraffin sections of COPD model rats were consistent with the characteristics pathological changes of COPD model in optical microscopic2. The muscle fiber of the COPD model rat was analosis.3. The weight of long extensor muscle digits of the malnutrition group were significantly decreased compared with that of the control group, the non—malnutrition group.While the weight of long extensor muscle digits of the non-malnutrition group were significantly decreased compared with that of the control group.The weight of the malnutrition group were significantly decreased compared with that of the control group, the non—malnutrition group.The weight of the non—malnutrition group were significantly decreased compared with that of the control group.4.The rates of apoptosis in malnutrition group were significantly higher than those of the control group, the non—malnutrition group.And the rates of apoptosis of the non-malnutrition and malnutrition of group were significantly higher than those of the control group.5.The expressions of ERK and Beclin-1 were significantly different among the COPD malnutrition group,COPD non—malnutrition group and the control group.Conclusion:1. The smoke and the tracheal instillation of elastase protease replicate COPD model successfully2. The apoptosis rate of COPD rat's skeletal muscle increases significantly. And the apoptosis rate of malnutrition COPD group is significantly higher than that of the non-malnutrition COPD group. The fact that the increase of expressions of ERK and Beclin-1 in COPD rat's skeletal muscle suggests that both of them participate in the Pathogenesis of skeletal muscle atrophy in COPD model rat.