Berry D A, Balcar V J, Barden J A, Keogh A, dos Remedios C G
Protein Laboratory Sutherland Center of Immunology, Sutherland Hospital, Caringbah, NSW, Australia.
Electrophoresis. 2000 Nov;21(17):3857-62. doi: 10.1002/1522-2683(200011)21:17<3857::AID-ELPS3857>3.0.CO;2-R.
This study is concerned with the molecular basis of human idiopathic dilated cardiomyopathy (DCM). This disorder affects the entire heart including both atria and ventricles. It is characterized by a progressive dilatation of the ventricles and loss of contractile power that results in an impaired cardiac output. Changes in cellular levels of dystrophin have been reported in patients with muscular dystrophies (Beckers and Duchenne) which manifest as DCM. However, previous studies using Western blots dos Remedios et al., Electrophoresis 1996, 17, 235-238) of samples of left ventricles from DCM patients showed no abnormalities in dystrophin content. P2X receptors are ATP-gated cation channels located in the sarcolemma. They are upregulated by a factor of about two in the atria of DCM patients compared with nondiseased control samples. A dystrophin-associated protein, alpha-sarcoglycan, has recently been shown to be an ecto-ATPase (an extracellular ATPase) capable of regulating ATP concentrations in the space between the cardiomyocytes. In this report we examine the relationship between changes in P2X1 receptors in left ventricle samples from DCM patients and the concentration of alpha-sarcoglycan. We found no evidence for upregulation of P2X1 receptors nor was the expression of alpha-sarcoglycan significantly altered.
本研究关注人类特发性扩张型心肌病（DCM）的分子基础。这种疾病会影响整个心脏，包括心房和心室。其特征是心室逐渐扩张以及收缩力丧失，进而导致心输出量受损。据报道，患有表现为DCM的肌营养不良症（贝克型和杜兴型）的患者，其肌营养不良蛋白的细胞水平会发生变化。然而，之前使用蛋白质免疫印迹法（dos Remedios等人，《电泳》，1996年，第17卷，第235 - 238页）对DCM患者左心室样本进行的研究表明，肌营养不良蛋白含量并无异常。P2X受体是位于肌膜上的ATP门控阳离子通道。与未患病的对照样本相比，DCM患者心房中的P2X受体上调了约两倍。一种与肌营养不良蛋白相关的蛋白，α - 肌聚糖，最近被证明是一种能够调节心肌细胞间空间中ATP浓度的胞外ATP酶（一种细胞外ATP酶）。在本报告中，我们研究了DCM患者左心室样本中P2X1受体的变化与α - 肌聚糖浓度之间的关系。我们没有发现P2X1受体上调的证据，α - 肌聚糖的表达也没有显著改变。
