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细胞壁是酵母菌的重要细胞器 ,参与细胞内外多方面的生理生化过程 ,如细胞絮凝、信号转导、致病性等 ,在决定细胞结构完整性方面起着重要的作用。酵母细胞壁是由 β - 1 ,3-葡聚糖、β - 1 ,6-葡聚糖、甘露聚糖蛋白及几丁质等相互交链构成的复杂的双层网状结构[1] 。细胞壁组成或结构的改变会使细胞产生对温度或低渗透压的敏感性 ,在相应的条件下发生自溶 ,使细胞内容物释放到胞外。产生上述效应的突变株称为温度敏感自溶突变株和低渗透敏感自溶突变株[2~ 4 ] 。对此类突变株的研究一方面有利于进一步阐明酵母菌细胞壁代谢及组装的调控机制… 相似文献
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Diego Rojas-Rivera Valentina Parra Ariel Contreras Mario Chiong Claudio Olea-Azar 《FEBS letters》2009,583(21):3485-3492
We investigated the role of Ca2+ in generating reactive oxygen species (ROS) induced by hyposmotic stress (Hypo) and its relationship to regulatory volume decrease (RVD) in cardiomyocytes. Hypo-induced increases in cytoplasmic and mitochondrial Ca2+. Nifedipine (Nife) inhibited both Hypo-induced Ca2+ and ROS increases. Overexpression of catalase (CAT) induced RVD and a decrease in Hypo-induced blebs. Nife prevented CAT-dependent RVD activation. These results show a dual role of Hypo-induced Ca2+ influx in the control of cardiomyocyte viability. Hypo-induced an intracellular Ca2+ increase which activated RVD and inhibited necrotic blebbing thus favoring cell survival, while simultaneously increasing ROS generation, which in turn inhibited RVD and induced necrosis. 相似文献
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A new concept in cryopreservation solution design was developed that focuses on the use of an intracellular-type, hypothermic maintenance medium coupled with additives that inhibit cryopreservation-induced apoptosis. HypoThermosol' (HTS), a hypothermic (4 degrees C) maintenance medium utilized in the long-term storage of cell, tissue, and organ systems, was tested for cryoprotective capability on a renal cell line (Madin-Darby Canine Kidney cells). HTS and HTS derivatives were tested against conventional cell culture medium (Dulbecco's Minimal Essential medium, DME) as the cryoprotectant carrier solution because (1) cells are exposed to an extended state of hypothermia during the freeze-thaw process, and (2) HTS is designed to protect cells exposed to a hypothermic state. Cells separately cryopreserved in either HTS or DME + 5% dimethyl sulfoxide (DMSO) yielded equivalent 24-h postthaw survival (approximately 30%) and 5-d recovery (approximately 90%). Cells cryopreserved in CryoStor CS 5, a HTS derivative containing 5% DMSO, yielded approximately 75% 24-h postthaw survival and recovery to 100% within 3 d. DNA gel electrophoresis was performed to determine the mechanisms of cell death contributing to cryopreservation failure. Cells preserved in DME (DMSO-free) died primarily through necrosis, whereas cells preserved in either DME + 5% DMSO, HTS, or CryoStor CS 5 died through a combination of apoptosis and necrosis. This observation led to the inclusion of an apoptotic inhibitor designed to improve cryopreservation outcome. MDCK cells cryopreserved in CryoStor CS 5 supplemented with an apoptotic inhibitor (Caspase I Inhibitor V), hereafter termed CryoStor CS 5N, resulted in a 24-h postthaw survival and recovery rate exceeding that of any other cryoprotective solution tested (85%). We conclude that: (1) the use of HTS (a dextran-based, intracellular-type solution) without DMSO can yield postthaw viability equivalent to that of standard DMSO-based cryopreservation methods, (2) postthaw viability can be significantly increased through the use of an intracellular-type solution in conjunction with DMSO, (3) the use of HTS allows for cryopreservation to be accomplished with reduced levels of cryoprotectants, and (4) the regulation of apoptosis is essential for the improvement of cryopreservation outcome. 相似文献
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