Article Text
Abstract
Introduction Muscle wasting, that is present in a subgroup of patients with COPD, is an independent predictor of health related quality of life and survival. The two-dimensional fluorescence difference in gel electrophoresis (2D-DIGE) technology is now recognised as an accurate method to determine and quantify proteins.
Methods and results With the aim of identifying proteins potentially involved in the process of muscle wasting, we performed 2D-DIGE protein expression profiling in the vastus lateralis of 10 patients with COPD and low fat free mass index (FFMI) (COPDL) (FEV1 33 ± 4.3%pred, FFMI 15 ± 0.2 Kg.m-2) in comparison with both 8 patients with preserved FFMI (COPDN) (FEV1 47 ± 7.3%pred, FFMI 19 ± 0.6 Kg.m-2) and 9 age and gender-matched healthy sedentary subjects (C) (FEV1 96 ± 4.0%pred, FFMI 20 ± 0.9 Kg.m-2). Data analysis was performed using DeCyder software and for protein identification MALDI_TOF mass spectrometry (MS).
Ten proteins, whose expression was significantly changed in COPDL, were identified; serum albumin (ALBU), heat shock protein beta-1 (HSPB1), peroxiredoxin-6 (PRDX6), Alpha-crystallin B chain (CRYAB) and Alpha-1-antitrypsin (A1AT) were increased while Histone-lysine N-methyltransferase (DOT1L), Troponin T (TNNT1), Myozenin-1 (MYOZ1), Myosin light chain 1 (MYL1) and mitochondrial ATP synthase subunit alpha (ATPA) were decreased.
Conclusion Our results showed a down-regulation of structural muscle proteins, proteins involved in myofibrillogenesis, cell cycle arrest and energy production and up-regulation of proteins reacting to cell stress and proteins involved in oxidative stress protection.
Supported by Chief Scientist Office (CSO) Scotl06/S1103/5 and FIS PI08/0320.