Is the myofibrillarlytic myocyte a forme fruste apoptotic myocyte?
Is the myofibrillarlytic myocyte a forme fruste apoptotic myocyte?
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DOI：
10.1016/j.athoracsur.2004.09.061
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发表时间：
2005-04-01
影响因子：
4.6
通讯作者：
Tomaszewski, JE
中科院分区：
文献类型：
--
作者：
Narula, N;Narula, J;Tomaszewski, JE
背景肌原纤维溶解（MFL）细胞常见于心肌梗死的内膜下心肌。由于心肌细胞的缺血性损伤也被认为会诱导细胞凋亡，我们评估了9例缺血性心肌病心脏移植过程中MFL细胞凋亡的发生率。胞质部分或完全透明的肌细胞，通常在内膜下观察到，被认为是MFL细胞。TUNEL和ISOL染色检测细胞凋亡，免疫组化检测caspase-3、Bcl 2、BCL-X-L、Bax、增殖细胞核抗原（PCNA）和Ki 67。4131 MFL细胞检查，1305（32%）拥有核在一个给定的组织切片; 1140（88%）的有核心肌细胞TUNEL阳性。在842个外观正常的细胞中，257个（31%）细胞在给定的组织切片中显示出细胞核。在这些对照区中的5例（1.9%）中观察到TUNEL染色。所有的MFL细胞对半胱天冬酶3染色阳性。抗凋亡蛋白Bcl 2和BCL-X-L在MFL细胞内和周围表现出强烈的上调，而促凋亡蛋白Bax的表达仅见于对照水平。MFL细胞核Ki 67阴性，PCNA阳性。目前的研究表明，大多数MFL细胞凋亡，并与caspase 3的上调。Bcl 2的同时上调代表了这些肌细胞中的存活努力。这与文献综述一致，即MFL细胞是活的，在心肌中持续很长时间，并且可能在功能上是可逆的。同时凋亡和生存本能的证据代表了一个概念上的悖论，并表明，经历凋亡的心肌细胞应服从重建的功能。(c)2005年，美国胸外科医师协会（Society of Thoracic Surgeons）
Background. Myofibrillarlytic (MFL) cells are commonly observed in subendocardial myocardium in myocardial infarction. Because ischemic damage to myocytes is also known to induce apoptosis, we evaluated the prevalence of apoptosis in MFL cells in nine ischemic cardiomyopathic hearts explanted during transplantation.Methods. Myocytes with partial or complete clearing of cytoplasm, observed commonly in the subendocardium, were recognized as MFL cells. Prevalence of apoptosis was defined by TUNEL and ISOL staining and further characterized by immunohistochemical staining for caspase-3, Bcl2, BCL-X-L, Bax, proliferating cell nuclear antigen (PCNA), and Ki67.Results. Of 4131 MFL cells examined, 1305 (32%) possessed nuclei in a given histologic section; 1140 (88%) of the nucleated myocardial cells were TUNEL positive. Of 842 cells with normal appearance, 257 (31%) cells demonstrated nuclei in the given histologic section. TUNEL staining was observed in 5 (1.9%) in these control areas. All MFL cells stained positive for caspase 3. The antiapoptotic proteins, Bcl2 and BCL-X-L, demonstrated intense upregulation within and surrounding MFL cells, whereas pro-apoptotic protein Bax expression was only seen at control level. The MFL cells had Ki67 negative and PCNA positive nuclei.Conclusions. The present study demonstrates that the majority of MFL cells are apoptotic and are associated with upregulation of caspase 3. Simultaneous upregulation of Bcl2 represents a survival effort in these myocytes. This is consistent with the review of the literature that MFL cells are viable, persist in myocardium for long time and may be functionally reversible. Evidence for concurrent apoptosis and survival instinct represent a conceptual paradox and suggests that myocytes undergoing apoptosis should be amenable to reconstitution of function. (c) 2005 by The Society of Thoracic Surgeons.