Subcellular distribution of chelatable iron: a laser scanning microscopic study in isolated hepatocytes and liver endothelial cells
Subcellular distribution of chelatable iron: a laser scanning microscopic study in isolated hepatocytes and liver endothelial cells
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DOI：
10.1042/0264-6021:3560061
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发表时间：
2001-05-15
影响因子：
4.1
通讯作者：
Rauen, U
中科院分区：
文献类型：
--
作者：
Petrat, F;de Groot, H;Rauen, U
细胞可螯合铁库（“游离铁”、“低分子量铁”、“不稳定铁库”）通常被认为主要存在于细胞质内。在本研究中，我们采用了先前建立的基于定量激光扫描显微镜的 Phen Green 方法，首次检查了单个完整细胞中可螯合铁的亚细胞分布。在分离的大鼠肝细胞和大鼠肝内皮细胞中进行的这些测量显示，不仅在细胞质中而且在其他几个亚细胞区室中都存在相当高浓度的可螯合铁。在分离的大鼠肝细胞中，我们确定细胞质内的螯合铁浓度为 5.8 +/- 2.6 μM，线粒体中的螯合铁浓度至少为 4.8 μM。肝细胞核含有浓度高达 6.6 +/- 2.9 μM 的可螯合铁。在大鼠肝内皮细胞中，所有这些区室中的螯合铁浓度甚至更高（细胞质，7.3 +/- 2.6 μM；细胞核，11.8 +/- 3.9 μM；线粒体，92-12.7 μM）；此外，在内体/溶酶体装置的一小部分亚群中检测到可螯合铁（约 16 +/- 4 muM）。因此，亚细胞可螯合铁的分布不均匀，这一事实对于（病理）生理过程来说是重要的考虑因素，并且对于使用铁螯合剂抑制氧化应激也具有影响。
The pool of cellular chelatable iron ('free iron', 'low-molecular-weight iron', the 'labile iron pool') is usually considered to reside mainly within the cytosol. For the present study we adapted our previously established Phen Green method, based on quantitative laser scanning microscopy, to examine the subcellular distribution of chelatable iron in single intact cells for the first time. These measurements, performed in isolated rat hepatocytes and rat liver endothelial cells, showed considerable concentrations of chelatable iron, not only in the cytosol but also in several other subcellular compartments. In isolated rat hepatocytes we determined a chelatable iron concentration of 5.8 +/- 2.6 muM within the cytosol and of at least 4.8 muM in mitochondria. The hepatocellular nucleus contained chelatable iron at the surprisingly high concentration of 6.6 +/- 2.9 muM. In rat liver endothelial cells, the concentration of chelatable iron within all these compartments was even higher (cytosol, 7.3 +/- 2.6 muM; nucleus, 11.8 +/- 3.9 muM; mitochondria, 92-12.7 muM); in addition, chelatable iron (approx. 16 +/- 4 muM) was detected in a small subpopulation of the endosomal/lysosomal apparatus. Hence there is an uneven distribution of subcellular chelatable iron, a fact that is important to consider for (patho)physiological processes and that also has implications for the use of iron chelators to inhibit oxidative stress.