Objective To investigate the role of AKT/FOXOs /atrogin-1/MuRF1 signaling pathway in skeletal muscle atrophy in rats with chronic obstructive pulmonary diseases( COPD) .Methods Passive cigarette smoking was used to establish COPD model. The protein expression of atrogin-1, MuRF1, FOXO-1, phosohorylated-AKT and total AKT were measured by Western blot. The mRNA expression of atrogin-1, MuRF1 and FOXO-1 were measured by reverse transcription-polymerase chain reaction( RT-PCR) . Results Compared with the control group, the mRNA expressions of atrogin-1, MuRF1 and FOXO-1 significantly increased in extensor digitorum longus ( EDL) of the COPD group (Plt;0.05 ) . Meanwhile the protein expression of atrogin-1 and MuRF1 significantly increased in the COPD group(Plt;0.05) , while the protein expression of FOXO-1 was not significantly different between two groups(Pgt;0.05) . In addition, , the protein expression of phosohorylated-AKTand the ratio of phosohorylated-AKT to total AKT significantly increased in EDL of the COPD group(Plt;0.05) . Conclusion The mRNA and protein expression of AKT/FOXOs/ atrogin-1 /MuRF1 in skeletal muscle are significantly increased in COPD rats, suggesting that AKT/FOXOs/ atrogin-1 /MuRF1 signalling pathway plays a crucial role in skeletal muscle atrophy of COPD.
