Tavichakorntrakool Ratree, Sriboonlue Pote, Prasongwattana Vitoon, Puapairoj Anucha, Yenchitsomanus Pa-thai, Sinchaikul Supachok, Chen Shui-Tein, Wongkham Chaisiri, Thongboonkerd Visith
Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
J Proteome Res. 2009 May;8(5):2586-93. doi: 10.1021/pr800941g.
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.
长期钾（K）缺乏所致肌病的分子机制仍未完全明确。在本研究中，我们检测了取自尸体受试者的股外侧肌蛋白质组图谱，将钾缺乏（KD）者（肌肉钾含量<80微摩尔/克湿重）与无钾缺乏（NKD）者（肌肉钾含量≥80微摩尔/克湿重）进行比较（每组n = 6）。提取肌肉蛋白质，通过二维电泳分离，并用考马斯亮蓝R250染色进行可视化。斑点匹配和强度分析显示，KD组中有11个蛋白质斑点的水平发生了显著变化（6个增加，5个减少）。串联飞行时间质谱（Q-TOF MS）和串联质谱（MS/MS）分析将这些变化的蛋白质鉴定为代谢酶（醛脱氢酶1A1、尿苷二磷酸葡萄糖焦磷酸化酶、烯醇化酶1、胞质苹果酸脱氢酶和碳酸酐酶III）、抗氧化剂（过氧化物酶3同工型b）、细胞骨架蛋白（慢肌型骨骼肌肌钙蛋白I和肌球蛋白轻链2）等。这些变化的蛋白质参与许多细胞功能，包括生物能量学、酸碱调节、氧化应激反应和肌肉收缩性。通过蛋白质免疫印迹分析进行验证，证实KD肌肉中过氧化物酶3水平升高和肌钙蛋白I水平降低。线性回归分析还显示，过氧化物酶3水平与肌肉钾含量之间存在显著负相关（r = -0.887；p<0.001），肌钙蛋白I水平与肌肉钾含量之间存在显著正相关（r = 0.618；p<0.05）。我们的结果表明这些变化的蛋白质在KD相关肌病的发生发展中起重要作用。
