Expression of diaphragmatic myostatin and correlation with apoptosis in rats with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow limitation and loss of lung function. The present study aimed to investigate the diaphragmatic protein expression of myostatin and its correlation with apoptosis in a rat model of CPOD. Sprague Dawley rats were randomly divided into a control group and a COPD group, the latter of which were exposed to cigarette smoke to build a rat model of COPD. The validity of the COPD model was evaluated by assessment of lung function and histopathological analysis. Diaphragmatic myostatin expression and apoptosis were measured by western blot and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling, respectively. The rat model of COPD was efficiently established by cigarette smoke exposure. Diaphragmatic myostatin expression and apoptotic index in COPD rats were obviously increased as compared with that in the control animals. A positive correlation between diaphragmatic myostatin expression and apoptotic index was identified (r=0.857). Diaphragmatic myostatin overexpression in rats with COPD may promote diaphragmatic apoptosis and atrophy, leading to diaphragm weakness and respiratory muscle dysfunction, which is involved in the pathology of COPD.