Usta Engin, Mustafi Migdat, Artunc Ferruh, Walker Tobias, Voth Vladimir, Aebert Hermann, Ziemer Gerhard
Children's University Hospital, Div, Congenital & Pediatric Cardiac Surgery; University Hospital Tübingen, Germany.
J Cardiothorac Surg. 2011 Mar 28;6:38. doi: 10.1186/1749-8090-6-38.
Cardioplegia and reperfusion of the myocardium may be associated with cardiomyocyte apoptosis and subsequent myocardial injury. In order to establish a pharmacological strategy for the prevention of these events, this study aimed to verify the reliability of our human cardiac model and to evaluate the pro-apoptotic properties of the sphingolipid second messenger ceramide and the anti-apoptotic properties of the acid sphingomyelinase inhibitor amitryptiline during simulated cardioplegia and reperfusion ex vivo.
Cardiac biopsies were retrieved from the right auricle of patients undergoing elective CABG before induction of cardiopulmonary bypass. Biopsies were exposed to ex vivo conditions of varying periods of cp/rep (30/10, 60/20, 120/40 min). Groups: I (untreated control, n = 10), II (treated control cp/rep, n = 10), III (cp/rep + ceramide, n = 10), IV (cp/rep + amitryptiline, n = 10) and V (cp/rep + ceramide + amitryptiline, n = 10). For detection of apoptosis anti-activated-caspase-3 and PARP-1 cleavage immunostaining were employed.
In group I the percentage of apoptotic cardiomyocytes was significantly (p < 0.05) low if compared to group II revealing a time-dependent increase. In group III ceramid increased and in group IV amitryptiline inhibited apoptosis significantly (p < 0.05). In contrast in group V, under the influence of ceramide and amitryptiline the induction of apoptosis was partially suppressed.
Ceramid induces and amitryptiline suppresses apoptosis significantly in our ex vivo setting. This finding warrants further studies aiming to evaluate potential beneficial effects of selective inhibition of apoptosis inducing mediators on the suppression of ischemia/reperfusion injury in clinical settings.
心肌停搏和再灌注可能与心肌细胞凋亡及随后的心肌损伤有关。为了建立预防这些事件的药理学策略,本研究旨在验证我们的人体心脏模型的可靠性,并评估鞘脂第二信使神经酰胺的促凋亡特性以及酸性鞘磷脂酶抑制剂阿米替林在体外模拟心肌停搏和再灌注期间的抗凋亡特性。
在体外循环诱导前,从接受择期冠状动脉旁路移植术(CABG)的患者右心耳获取心脏活检组织。将活检组织暴露于不同时长的体外心肌停搏/再灌注(cp/rep,分别为30/10、60/20、120/40分钟)条件下。分组:I组(未处理对照组,n = 10),II组(处理对照组cp/rep,n = 10),III组(cp/rep + 神经酰胺,n = 10),IV组(cp/rep + 阿米替林,n = 10)和V组(cp/rep + 神经酰胺 + 阿米替林,n = 10)。采用抗活化半胱天冬酶-3和PARP-1裂解免疫染色检测凋亡情况。
与II组相比,I组凋亡心肌细胞百分比显著较低(p < 0.05),且呈时间依赖性增加。III组中神经酰胺增加,IV组中阿米替林显著抑制凋亡(p < 0.05)。相比之下,在神经酰胺和阿米替林的影响下,V组中凋亡诱导被部分抑制。
在我们的体外实验中,神经酰胺诱导凋亡,而阿米替林显著抑制凋亡。这一发现值得进一步研究,旨在评估选择性抑制凋亡诱导介质对临床环境中缺血/再灌注损伤抑制的潜在有益作用。