Ausma J, van Eys G J, Broers J L, Thoné F, Flameng W, Ramaekers F C, Borgers M
Department of Molecular Cell Biology & Genetics, Maastricht, University of Limburg, The Netherlands.
J Mol Cell Cardiol. 1996 Jun;28(6):1297-305. doi: 10.1006/jmcc.1996.0120.
Cardiomyocytes of chronic hibernating myocardium are known to undergo structural changes, indicative of dedifferentiation. Amongst these are changes in nuclear shape and chromatin distribution. Nuclear A-type lamins are known to be expressed in a differentiation-related fashion and to contribute to nuclear integrity and chromatin organization. Lamin expression was investigated with immunocytochemical staining procedures in biopsies from patients with chronic hibernating myocardium. The expression of A-type (lamin A and C) were shown to be downregulated during hibernation, while lamin B2 remained present in hibernating cardiomyocytes in a way similar to embryonic muscle cells. All heart muscle cells were shown to be negative for lamin B1. The absence of A-type lamins in chronic hibernating cardiomyocytes could be taken as an additional argument for the dedifferentiation state of these cells. The absence of A-type lamins was accompanied by dispersion of the nuclear heterochromatin, in a way similar to nuclei of embryonic cardiomyocytes.
已知慢性冬眠心肌的心肌细胞会发生结构变化，这表明其去分化。其中包括核形状和染色质分布的变化。已知核A型核纤层蛋白以与分化相关的方式表达，并有助于核完整性和染色质组织。采用免疫细胞化学染色方法对慢性冬眠心肌患者的活检组织进行核纤层蛋白表达研究。结果显示，A型（核纤层蛋白A和C）在冬眠期间表达下调，而核纤层蛋白B2在冬眠心肌细胞中的存在方式与胚胎肌肉细胞相似。所有心肌细胞的核纤层蛋白B1均呈阴性。慢性冬眠心肌细胞中缺乏A型核纤层蛋白可被视为这些细胞处于去分化状态的又一证据。A型核纤层蛋白的缺乏伴随着核异染色质的分散，其方式类似于胚胎心肌细胞核。
