ObjectiveTo investigate the changes of autophage-related protein in lung tissues of rats with chronic obstructive pulmonary disease (COPD). MethodsPassive cigarette smoking was used to establish COPD model in rats. The mRNA and protein expressions of PI3K, total AKT, phosphorylated-AKT, total mTOR, phosphorylated-mTOR, and autophagy-related genes including LC3Ⅱ/Ⅰ, Beclin1, Atg5, Atg7, Atg12, P62 in lung tissues were measured by real-time PCR and Western blot. The autophagy level was compared between the COPD rats and the normal rats by LC3B immunohistochemistry. ResultsReal-time PCR analysis showed that the mRNA expressions of Beclin1, Atg5 and Atg12 significantly increased in lung tissues of the COPD rats compared with the normal rats (all P < 05). There was no significant difference between the COPD rats and the normal rats as for Atg7 mRNA expression (P > 0.05). Western blot analysis showed that the protein expressions of PI3K, p-AKT/AKT and p-mTOR/mTOR significantly decreased, the protein expressions of LC3 Ⅱ/Ⅰ, Atg5, and Beclin1 increased, and protein expression of P62 significantly decreased in lung tissues of the COPD rats compared with the normal rats (all P < 05). LC3B immunohistochemistry showed that the LC3B expression was higher in the COPD rats than that in the normal rats. ConclusionThe level of autophagy significantly increases in COPD rats with decreased expression of upstream proteins in autophagy signal pathway and increased expression of autophage proteins.
ObjectiveTo investigate the role of autophagy-lysosomal system in skeletal muscle atrophy in rats with chronic obstructive pulmonary disease (COPD). MethodsPassive cigarette smoking was used to establish COPD model. The mRNA and protein expression of FOXO transcription factor and autophagy-related genes Bnip3, Beclin1, p62, MAP-LC3Ⅱ/Ⅰ, Atg5 in extensor digitorum longus of rats were measured by real time PCR and Western blot. The changes of extensor digitorum longus tissue sections and lung tissue sections in the experimental group rats were observed under transmission electron microscopy. ResultsCompared with the control group, the mRNA expression of FOXO transcription factor and autophagy-related genes Bnip3, Beclin1, p62, Atg5 in extensor digitorum longus of the experimental group group rats was significantly increased (all P<0.05, as for Bnip3, the P value between two groups <0.01); The mRNA expression of MAP-LC3Ⅱ/Ⅰwas not significantly different between two groups (P>0.05). The protein expression of FOXO, Bnip3, Beclin1, p62, MAP-LC3Ⅱ/Ⅰ, Atg5 significantly increased in the COPD group (all P<0.05, as for Bnip3, MAP-LC3Ⅱ/Ⅰ, Beclin1, the P values between two groups <0.01). Compared with the control group, autolysosome in extensor digitorum longus tissue sections of the experimental group rats increased and lung tissue fibrosis and more inflammatory cells were observed in lung tissue sections of the experimental group rats under transmission electron microscopy. ConclusionThe mRNA and protein expressions of FOXO transcription factor and autophagy-related genes in extensor digitorum longus increase significantly in the experimental group rats, suggesting that the activity of autophagy-lysosomal system, which may be one mechanism of skeletal muscle atrophy in COPD.
ObjectiveTo investigate the expression of autophagy-related genes and proteins in the lung tissues of patients with non-small cell lung cancer (NSCLC).MethodsPulmonary tissues were obtained from the surgically resected lung tissues of patients with NSCLC who were clinical diagnosed. The lung cancer tissues were derived from the pathologically diagnosed NSCLC and the normal tissues were from lung tissues 5 cm away from the lung lesions (29 cases in the lung cancer group and 32 cases in the normal group). The expression of autophagy-related proteins ATG5, LC3B, and p62 in lung tissues were measured by Western blot, and mRNA expression of ATG5 and p62 in the lung tissues were measured by real-time PCR.ResultsWestern blot analysis showed that the expression of ATG5 and p62 in lung cancer group were significantly higher than those in normal group (P<0.05). However, the expression of LC3B in lung cancer group was significantly lower than that in normal group (P<0.05). Real-time PCR analysis found that the mRNA expression of ATG5 and p62 in lung cancer group were significantly higher than those in normal group (P<0.05). The expression of ATG5, LC3B and p62 had no relationship with gender, age, smoking history, tumor location, tumor size, clinicopathological classification, differentiation or TNM stage. The expression of ATG5 had statistical significance in lymph node metastasis (P<0.05), but there was no difference for LC3B or p62 in lymph node metastasis (P>0.05).ConclusionsAutophagy plays a role in the tumorigenesis of lung cancer. If it’s possible to regulate and control autophagy-related genes and proteins effectively, it may supply new insights or targets into treatment for lung cancer patients.