Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
Molecular and Cellular Pharmacology Training Program, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.
J Proteome Res. 2023 Mar 3;22(3):931-941. doi: 10.1021/acs.jproteome.2c00729. Epub 2023 Feb 17.
Ischemic cardiomyopathy (ICM) is a prominent form of heart failure, but the molecular mechanisms underlying ICM remain relatively understudied due to marked phenotypic heterogeneity. Alterations in post-translational modifications (PTMs) and isoform switches in sarcomeric proteins play important roles in cardiac pathophysiology. Thus, it is essential to define sarcomeric proteoform landscape to better understand ICM. Herein, we have implemented a top-down liquid chromatography (LC)-mass spectrometry (MS)-based proteomics method for the identification and quantification of sarcomeric proteoforms in the myocardia of donors without heart diseases ( = 16) compared to end-stage ICM patients ( = 16). Importantly, quantification of post-translational modifications (PTMs) and expression reveal significant changes in various sarcomeric proteins extracted from ICM tissues. Changes include altered phosphorylation and expression of cardiac troponin I (cTnI) and enigma homologue 2 (ENH2) as well as an increase in muscle LIM protein (MLP) and calsarcin-1 (Cal-1) phosphorylation in ICM hearts. Our results imply that the contractile apparatus of the sarcomere is severely dysregulated during ICM. Thus, this is the first study to uncover significant molecular changes to multiple sarcomeric proteins in the LV myocardia of the end-stage ICM patients using liquid chromatography-mass spectrometry (LC-MS)-based top-down proteomics. Raw data are available via the PRIDE repository with identifier PXD038066.
缺血性心肌病（ICM）是心力衰竭的一种突出形式，但由于表型异质性显著，ICM 的分子机制仍相对研究不足。肌节蛋白翻译后修饰（PTMs）的改变和肌节蛋白异构体的转换在心脏病理生理学中发挥着重要作用。因此，定义肌节蛋白的蛋白质组学图谱对于更好地理解 ICM 至关重要。在此，我们采用了自上而下的液相色谱（LC）-质谱（MS）-基于蛋白质组学的方法，用于鉴定和定量来自无心脏病供体（n = 16）和终末期 ICM 患者（n = 16）心肌中的肌节蛋白蛋白质组。重要的是，对翻译后修饰（PTMs）和表达的定量揭示了从 ICM 组织中提取的各种肌节蛋白的显著变化。变化包括心肌肌钙蛋白 I（cTnI）和谜蛋白同源物 2（ENH2）的磷酸化和表达改变，以及肌 LIM 蛋白（MLP）和钙调蛋白 1（Cal-1）在 ICM 心脏中的磷酸化增加。我们的结果表明，在 ICM 期间，肌节的收缩装置严重失调。因此，这是第一项使用基于 LC-MS 的自上而下蛋白质组学技术在终末期 ICM 患者左心室心肌中发现多种肌节蛋白发生显著分子变化的研究。原始数据可通过 PRIDE 存储库获取，标识符为 PXD038066。
