Cell death upon H(2)O(2) induction in the unicellular green alga Micrasterias.
Cell death upon H(2)O(2) induction in the unicellular green alga Micrasterias.
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DOI：
10.1111/j.1438-8677.2008.00078.x
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发表时间：
2008-11
期刊：
影响因子：
--
通讯作者：
Lütz-Meindl U
中科院分区：
文献类型：
--
作者：
Darehshouri A;Affenzeller M;Lütz-Meindl U
在本研究中，我们调查是否单细胞的绿色微栅藻denticulata是能够执行程序性细胞死亡（PCD）的实验诱导和形态，分子和生理特征。这是特别令人感兴趣的，因为生长在浅沼泽池塘中的单细胞淡水绿色藻类暴露于极端环境条件，并且执行PCD的能力可以提供保证种群存活的重要策略。理论上“不朽”的微栅格是这种研究的理想对象，因为它多年来一直作为细胞生物学模型系统，并且其整个细胞周期的生长特性、生理学和超微结构的细节是众所周知的。用低浓度的H2 O2已知诱导PCD在其他生物体中的治疗导致在TEM中观察到的细胞器的严重的超微结构变化。这些包括变形和部分解体的线粒体，异常扩张的池边缘的dictyosomes，多泡体的发生，ER室的数量增加和染色质的轻微凝聚。此外，可以检测到胱天蛋白酶-3样活性的统计学显著增加，其被胱天蛋白酶-3抑制剂消除。光合活性测定快速叶绿素荧光作为H2 O2暴露的结果，而色素组合物，除了类胡萝卜素的减少，是相同的，在未经处理的控制。TUNEL阳性染色和DNA梯状降解是高等植物细胞程序性死亡的标志，但仅在死亡的微星藻细胞中检测到。
In the present study we investigate whether the unicellular green alga Micrasterias denticulata is capable of executing programmed cell death (PCD) upon experimental induction and by which morphological, molecular and physiological hallmarks it is characterized. This is particularly interesting as unicellular fresh water green algae growing in shallow bog ponds are exposed to extreme environmental conditions and the capability to perform PCD may provide an important strategy to guarantee survival of the population. The theoretically “immortal” alga Micrasterias is an ideal object for such investigations as it has served as a cell biological model system since many years and details on its growth properties, physiology and ultrastructure throughout the cell cycle are well known. Treatment with low concentrations of H2O2 known to induce PCD in other organisms resulted in severe ultrastructural changes of organelles as observed in TEM. These include deformation and partly disintegration of mitochondria, abnormal dilatation of cisternal rims of dictyosomes, the occurrence of multivesicular bodies, an increase in the number of ER compartments and slight condensation of chromatin. Additionally, a statistically significant increase in caspase-3-like activity could be detected which was abrogated by a caspase-3 inhibitor. Photosynthetic activity measured by fast chlorophyll fluorescence decreased as a consequence of H2O2 exposure whereas pigment composition, except of a reduction in carotenoids, was the same as in untreated controls. TUNEL positive staining and ladder-like degradation of DNA, both frequently regarded as PCD hallmark in higher plants could only be detected in dead Micrasterias cells.
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影响因子：
4.3
作者：
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3.5
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