Department of Pathology and Laboratory Medicine, Cancer Research Cluster, University of Saskatchewan, Room 4D40, 107 Wiggins Road, Saskatoon, Saskatchewan S7N 5E5, Canada.
Department of Pathology and Laboratory Medicine, Cancer Research Cluster, University of Saskatchewan, Room 4D40, 107 Wiggins Road, Saskatoon, Saskatchewan S7N 5E5, Canada.
Biochem Biophys Res Commun. 2014 Jan 10;443(2):604-9. doi: 10.1016/j.bbrc.2013.12.019. Epub 2013 Dec 11.
A rise in intracellular myocardial Ca(2+) during cardiac ischemia activates calpain (Calpn) thereby causing damage to myocardial proteins, which leads to myocyte death and consequently to loss of myocardial structure and function. Calcineurin (CaN) interacts with Calpn and causes cellular damage eventually leading to cell death. Calpastatin (Calp) and high molecular weight calmodulin-binding protein (HMWCaMBP) (homolog of Calp), inhibit Calpn activity and thus prevent cell death. CaN stimulation can also result in self-repair of damaged cardiomyocytes. The present study attempts to elucidate the expression of these proteins in cells under pre-ischemic condition (control), following ischemia induction and also reperfusion subsequent to ischemia. For the first time, flow cytometric analysis (FACS) has been used for analyzing protein expression concurrently with viability. We induced ischemia and subsequently reperfusion in 80% confluent cultures of neonatal murine cardiomyocytes (NMCC). Viability following induction was assessed with 7-AAD staining and the cells were simultaneously checked for protein expression by FACS. We observed that ischemia induction results in increased expression of CaN, Calp and Calpn. HMWCaMBP expression was reduced in live cells following ischemia which suggests that there is a poor survival outcome of cells expressing HMWCaMBP thereby making it a potential biomarker for such cells. Most live cells following ischemia expressed CaN pointing towards self-repair and favorable survival outcomes.
在心肌缺血期间,细胞内心肌 Ca(2+)的增加会激活钙蛋白酶(Calpn),从而导致心肌蛋白受损,导致心肌细胞死亡,进而导致心肌结构和功能丧失。钙调神经磷酸酶(CaN)与 Calpn 相互作用并导致细胞损伤,最终导致细胞死亡。钙蛋白酶抑制剂(Calp)和高分子量钙调蛋白结合蛋白(HMWCaMBP)(Calp 的同源物)抑制 Calpn 活性,从而防止细胞死亡。CaN 的刺激也可以导致受损心肌细胞的自我修复。本研究试图阐明这些蛋白质在缺血前条件(对照)下、缺血诱导后以及随后再灌注时细胞中的表达情况。首次使用流式细胞术分析(FACS)同时分析蛋白质表达和细胞活力。我们在 80%汇合培养的新生鼠心肌细胞(NMCC)中诱导缺血,随后再灌注。用 7-AAD 染色评估诱导后的活力,并通过 FACS 同时检查细胞的蛋白质表达。我们观察到,缺血诱导会导致 CaN、Calp 和 Calpn 的表达增加。缺血后活细胞中 HMWCaMBP 的表达减少,这表明表达 HMWCaMBP 的细胞生存结局较差,因此它可能成为此类细胞的潜在生物标志物。缺血后大多数活细胞表达 CaN,这表明细胞具有自我修复和良好的生存结局。