JOURNAL ARTICLE

Downregulation of lung mitochondrial prohibitin in COPD

Nikolaos Soulitzis, Eirini Neofytou, Maria Psarrou, Aristotelis Anagnostis, Nektarios Tavernarakis, Nikolaos Siafakas, Eleni G Tzortzaki
Respiratory Medicine 2012, 106 (7): 954-61
22521224
Prohibitins (PHB1 and PHB2) are versatile proteins located at the inner mitochondrial membrane, maintaining normal mitochondrial function and morphology. They interact with the NADH dehydrogenase protein complex, which is essential for oxidoreductase activity within cells. However, their expression in lung epithelium, especially in smokers and patients with inflammatory lung diseases associated with increased oxidative stress, such as COPD, is unknown. Lung tissue specimens from 45 male subjects were studied: 20 COPD patients [age: 65.7 ± 5.8 years, smoking: 84.6 ± 33.6 pack-years, FEV(1) (%pred.): 58.7 ± 14.6, FEV(1)/FVC (%): 63.8 ± 9.4], 15 non-COPD smokers [age: 59.0 ± 12.1 years, smoking: 52.5 ± 20.8 pack-years, FEV(1) (%pred.): 85.5 ± 14.2, FEV(1)/FVC (%): 78.5 ± 4.7] and 10 non-smokers. Quantitative real-time PCR experiments were carried out for PHB1 and PHB2, using β-actin as internal control. Non-COPD smokers exhibited lower PHB1 mRNA levels when compared to non-smokers (0.55 ± 0.06 vs. 0.90 ± 0.06, P = 0.043), while PHB1 expression was even further decreased in COPD patients (0.32 ± 0.02), a statistically significant finding vs. both non-COPD smokers (P = 0.040) and non-smokers (P < 0.001). By contrast, PHB2 levels were similar among the three study groups. Western blot analysis for the PHB1 protein verified the qPCR results (non-smokers: 1.77 ± 0.13; non-COPD smokers: 0.97 ± 0.08; COPD patients: 0.59 ± 0.10, P = 0.007). Further analysis revealed that PHB1 downregulation in COPD patients cannot be attributed solely to smoking, and that PHB1 expression levels are associated with the degree of airway obstruction [FEV(1) (P(mRNA) = 0.004, P(protein) = 0.014)]. The significant downregulation of PHB1 in COPD and non-COPD smokers in comparison to non-smokers possibly reflects a distorted mitochondrial function due to decreased mitochondrial stability, especially in the mitochondria of COPD patients.

Full Text Links

Find Full Text Links for this Article

Discussion

You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read
22521224
×

Save your favorite articles in one place with a free QxMD account.

×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"