Department of Botany, Faculty of Science and Technology, University of Debrecen, Debrecen H-4010, Egyetem tér 1, Hungary.
Mar Drugs. 2013 Sep 30;11(10):3689-717. doi: 10.3390/md11103689.
Cyanobacteria produce metabolites with diverse bioactivities, structures and pharmacological properties. The effects of microcystins (MCYs), a family of peptide type protein-phosphatase inhibitors and cylindrospermopsin (CYN), an alkaloid type of protein synthesis blocker will be discussed in this review. We are focusing mainly on cyanotoxin-induced changes of chromatin organization and their possible cellular mechanisms. The particularities of plant cells explain the importance of such studies. Preprophase bands (PPBs) are premitotic cytoskeletal structures important in the determination of plant cell division plane. Phragmoplasts are cytoskeletal structures involved in plant cytokinesis. Both cyanotoxins induce the formation of multipolar spindles and disrupted phragmoplasts, leading to abnormal sister chromatid segregation during mitosis. Thus, MCY and CYN are probably inducing alterations of chromosome number. MCY induces programmed cell death: chromatin condensation, nucleus fragmentation, necrosis, alterations of nuclease and protease enzyme activities and patterns. The above effects may be related to elevated reactive oxygen species (ROS) and/or disfunctioning of microtubule associated proteins. Specific effects: MCY-LR induces histone H3 hyperphosphorylation leading to incomplete chromatid segregation and the formation of micronuclei. CYN induces the formation of split or double PPB directly related to protein synthesis inhibition. Cyanotoxins are powerful tools in the study of plant cell organization.
蓝藻产生具有多种生物活性、结构和药理特性的代谢物。本文将讨论微囊藻毒素（MCYs）和节球藻毒素（CYN）这两种家族的抑肽酶和生物碱型蛋白合成抑制剂的作用。我们主要关注蓝藻毒素诱导的染色质组织变化及其可能的细胞机制。植物细胞的特殊性解释了此类研究的重要性。前期带（PPB）是有丝分裂前期细胞骨架结构，在确定植物细胞分裂面中起重要作用。成膜体是参与植物胞质分裂的细胞骨架结构。这两种蓝藻毒素都能诱导多极纺锤体和分裂成膜体的形成，导致有丝分裂过程中姐妹染色单体的异常分离。因此，MCY 和 CYN 可能会导致染色体数目的改变。MCY 诱导程序性细胞死亡：染色质浓缩、核碎裂、坏死、核酸酶和蛋白酶活性及模式的改变。这些影响可能与活性氧（ROS）的增加或微管相关蛋白的功能障碍有关。特定影响：MCY-LR 诱导组蛋白 H3 过度磷酸化，导致不完全的染色单体分离和微核的形成。CYN 诱导分裂或双前期带的形成，这与蛋白合成抑制直接相关。蓝藻毒素是研究植物细胞组织的有力工具。
