Fluorescence spectroscopy and imaging of myocardial apoptosis
Fluorescence spectroscopy and imaging of myocardial apoptosis
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DOI：
10.1117/1.2400701
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发表时间：
2006-11-01
影响因子：
3.5
通讯作者：
Chance, Britton
中科院分区：
文献类型：
--
作者：
Ranji, Mahsa;Kanemoto, Shinya;Chance, Britton
用荧光分光光度法检测开胸兔心肌缺血再灌注损伤模型中内源性黄素蛋白(FP)和烟酰胺腺嘌呤二核苷酸(NADH)信号。临床研究表明，心肌细胞的凋亡与缺血心肌再灌注后的心肌梗死面积有关。在这种情况下，一种评估细胞凋亡的非侵入性手段将有助于随后的心室重塑的治疗。我们的研究表明，体内荧光法可用于检测开胸手术中的细胞凋亡。心肌氧化还原状态的特殊变化已被证明是细胞凋亡的存在。在常氧、缺血和再灌流实验过程中，检测了线粒体两个主要的内源性荧光团，NADH和FP信号。通过阻断冠状动脉回旋支最大支致心肌缺血，应用两种不同的荧光技术：活体荧光测定法和死后冷冻成像技术采集荧光信号。第一种技术用于在体内检测FP和NADH信号，第二种技术使用冷冻捕获和低温荧光成像。当心脏仍在胸腔内时，心脏被快速冷冻，以拍摄组织新陈代谢状态的快照。冷冻后，切除缺血区及其周围交界区，将标本埋入冰冻缓冲液中进行冷冻扫描。这两组数据，体内荧光法和低温氧化还原扫描，显示一致的线粒体氧化还原状态的极端氧化(较高的氧化还原比率)，表明再灌注后启动了细胞凋亡。这是第一次尝试评估心脏跳动中的心肌细胞凋亡。(C)2006年光学仪器工程师学会。
Fluorometry is used to detect intrinsic flavoprotein (FP) and nicotinamide adenine dinucleotide (NADH) signals in an open-chest rabbit model of myocardial ischemia-reperfusion injury. Myocyte apoptosis has been shown clinically to contribute to infarct size following reperfusion of ischemic myocardium. A noninvasive means of assessing apoptosis in this setting would aid in the treatment of subsequent ventricular remodeling. We show that in vivo fluorometry can be useful in apoptosis detection in open-chest surgeries. Specific changes in myocardial redox states have been shown to indicate the presence of apoptosis. Two main mitochondrial intrinsic fluorophores, NADH and FP signals, were measured during normoxia, ischemia, and reperfusion experimental protocol. Ischemia was induced by occlusion of the largest branch of the circumflex coronary artery and fluorescence signals are collected by applying two different fluorescence techniques: in vivo fluorometry and postmortem cryoimaging. The first technique was employed to detect FP and NADH signals in vivo and the latter technique uses freeze trapping and low-temperature fluorescence imaging. The heart is snap frozen while still in the chest cavity to make a "snapshot" of the metabolic state of the tissue. After freezing, the ischemic area and its surrounding border zone were excised and the sample was embedded in a frozen buffer for cryoscanning. These two data sets, in vivo fluorometry and low-temperature redox scanning, show consistent extreme oxidation of the mitochondrial redox states (higher redox ratio) suggesting the initiation of apoptosis following reperfusion. This represents the first attempt to assess myocyte apoptosis in the beating heart. (c) 2006 Society of Photo-Optical Instrumentation Engineers.