Metabolic enzymes, antioxidants, and cytoskeletal proteins are significantly altered in vastus lateralis muscle of K-depleted cadaveric subjects.
Molecular mechanisms underlying myopathy caused by prolonged potassium (K) depletion remain poorly understood. In the present study, we examined proteome profile of vastus lateralis muscle obtained from cadaveric subjects who had K depletion (KD) (muscle K<80 micromol/g wet weight) compared to those who had no KD (NKD) (muscle K>or=80 micromol/g wet weight) (n=6 per group). Muscle proteins were extracted, resolved by 2-DE, and visualized with CBB-R250 stain. Spot matching and intensity analysis revealed significant changes in levels of 11 (6 increased and 5 decreased) protein spots in the KD group. Q-TOF MS and MS/MS analyses identified these altered proteins as metabolic enzymes (aldehyde dehydrogenase 1A1, uridine diphosphoglucose pyrophosphorylase, enolase 1, cytosolic malate dehydrogenase, and carbonic anhydrase III), antioxidants (peroxiredoxin-3 isoform b), cytoskeletal proteins (slow-twitch skeletal troponin I and myosin light chain 2), and others. These altered proteins are involved in many cellular functions, including bioenergetics, acid-base regulation, oxidative stress response, and muscle contractility. Validation was done by Western blot analysis, which confirmed the increased level of peroxiredoxin-3 and decreased level of troponin-I in the KD muscle. Linear regression analysis also revealed a significant negative correlation between peroxiredoxin-3 level and muscle K content (r=-0.887; p<0.001), as well as a significant positive correlation between troponin-I level and muscle K content (r=0.618; p<0.05). Our results implicate the important roles these altered proteins play in the development of KD-associated myopathy.
Tavichakorntrakool
Ratree
R
Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
Sriboonlue
Pote
P
Prasongwattana
Vitoon
V
Puapairoj
Anucha
A
Yenchitsomanus
Pa-thai
PT
Sinchaikul
Supachok
S
Chen
Shui-Tein
ST
Wongkham
Chaisiri
C
Thongboonkerd
Visith
V
D000444:Aldehyde Dehydrogenase / Q000378:metabolism; D000975:Antioxidants / Q000378:metabolism*; D015153:Blotting, Western; D002102:Cadaver; D024403:Carbonic Anhydrase III / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D003600:Cytosol / Q000201:enzymology; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D008291:Malate Dehydrogenase / Q000378:metabolism; D008297:Male; D009124:Muscle Proteins / Q000378:metabolism*; D054464:Peroxiredoxins / Q000378:metabolism; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D040901:Proteomics / Q000379:methods; D052097:Quadriceps Muscle / Q000201:enzymology / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D019210:Troponin I / Q000378:metabolism; D005957:UTP-Glucose-1-Phosphate Uridylyltransferase / Q000378:metabolism
D000975:Antioxidants; D003598:Cytoskeletal Proteins; D009124:Muscle Proteins; D019210:Troponin I; D008291:Malate Dehydrogenase; D054464:Peroxiredoxins; D000444:Aldehyde Dehydrogenase; D005957:UTP-Glucose-1-Phosphate Uridylyltransferase; D024403:Carbonic Anhydrase III; D010751:Phosphopyruvate Hydratase; D011188:Potassium