Bovine Lactadherin as a Calcium-independent Imaging Agent of Phosphatidylserine Expressed on the Surface of Apoptotic HeLa Cells
Bovine Lactadherin as a Calcium-independent Imaging Agent of Phosphatidylserine Expressed on the Surface of Apoptotic HeLa Cells
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DOI：
10.1369/jhc.2009.953729
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发表时间：
2009-10-01
影响因子：
3.2
通讯作者：
Rasmussen, Jan T.
中科院分区：
文献类型：
--
作者：
Waehrens, Lasse N.;Heegaard, Christian W.;Rasmussen, Jan T.
牛乳胶粘附素对磷脂酰丝氨酸(PS)膜结构域具有立体特异性亲和力，并在低于基准PS探针Annexin V的PS浓度下与PS结合。因此，与Annexin V相比，乳粘附素在凋亡前永生化白血病细胞上识别PS的时间点更早。在本研究中，以宫颈癌细胞系HeLa为模型系统，比较了当贴壁细胞进入凋亡程序时PS与两种PS结合蛋白的形态分布。在玻璃培养皿上培养HeLa细胞，用星形孢子素诱导细胞凋亡。荧光标记乳胶粘附素和/或膜联蛋白V用于共聚焦显微镜检测PS暴露。乳胶粘附素和膜联蛋白V染色均显示PS定位于质膜边缘和滤过泡。此外，乳胶粘附素发现PS暴露在长丝足样延伸物上，而Annexin V内化在颗粒状结构中。总而言之，这些数据进一步描绘了乳胶粘连蛋白和膜联蛋白V在PS结合模式上的差异。
Bovine lactadherin holds a stereo-specific affinity for phosphatidylserine (PS) membrane domains and binds at PS concentrations lower than the benchmark PS probe, annexin V. Accordingly, lactadherin has recognized PS exposure on preapoptotic immortalized leukemia cells at an earlier time point than has annexin V. In the present study, the cervical cancer cell line HeLa has been employed as a model system to compare the topographic distribution of PS with the two PS binding proteins as adherent cells enter the apoptotic program. HeLa cells were cultured on glass-bottom Petri dishes, and apoptosis was induced by staurosporine. Fluorescence-labeled lactadherin and/or annexin V were used to detect PS exposure by confocal microscopy. Both lactadherin and annexin V staining revealed PS localized to plasma membrane rim and blebs. In addition, lactadherin identified PS exposure on long filopodia-like extensions, whereas annexin V internalized in granule-like structures. All in all, the data further delineate the differences in PS binding patterns of lactadherin and annexin V. (J Histochem Cytochem 57:907-914,2009)