Solar Radiation Induces Non-Nuclear Perturbations and a False Start to Regulated Exocytosis in Cryptosporidium parvum
Solar Radiation Induces Non-Nuclear Perturbations and a False Start to Regulated Exocytosis in Cryptosporidium parvum
复制标题
太阳辐射诱导非核扰动和隐孢子虫胞吐作用的错误启动
作者：
B. King;D. Hoefel;Pao Ee Wong;Paul Monis
平流层臭氧消耗、气候变暖和水生生态系统酸化导致到达许多水生环境的太阳辐射水平升高，对多种生物体的有害影响增加。虽然人们认为对生物体的有害影响主要是通过 DNA 损伤而发生的，但太阳紫外线也会损害细胞蛋白质、脂质和信号通路。隐孢子虫是真核顶复门的成员，含有许多囊泡分泌细胞器，它们通过调节的胞吐作用排出对于感染的成功建立至关重要。使用流式细胞术技术，我们证明太阳紫外线快速诱导子孢子胞吐作用，导致子孢子附着和侵入宿主细胞的能力显着降低。我们发现太阳紫外线诱导子孢子膜去极化，导致细胞 ATP 减少和胞质钙增加。这些变化伴随着子孢子内部粒度的减少，表明顶端细胞器放电，这一点通过使用胞吐作用敏感染料对子孢子进行分析得到了证实。在存在兼容宿主细胞的情况下，顶端细胞器放电的精确时间对于子孢子的附着和侵袭至关重要。我们的结果首次证明了太阳紫外线辐射如何干扰胞吐作用，这是所有真核细胞的基本细胞过程。我们认为，不仅水生和陆地环境中太阳辐射的预计增加会显着影响顶复合体的成员，太阳紫外线诱导的膜去极化导致细胞质钙扰动可能通过对无数钙依赖性细胞功能的拮抗作用影响更广泛的真核生物。
Stratospheric ozone depletion, climate warming and acidification of aquatic ecosystems have resulted in elevated levels of solar radiation reaching many aquatic environments with an increased deleterious impact on a wide range of living organisms. While detrimental effects on living organisms are thought to occur primarily through DNA damage, solar UV can also damage cellular proteins, lipids and signalling pathways. Cryptosporidium, a member of the eukaryotic phylum Apicomplexa, contain numerous vesicular secretory organelles and their discharge via regulated exocytosis is essential for the successful establishment of infection. Using flow cytometric techniques we demonstrate that solar UV rapidly induces sporozoite exocytosis resulting in a significant reduction in the ability of sporozoites to attach and invade host cells. We found that solar UV induced sporozoite membrane depolarization, resulting in reduced cellular ATP and increased cytosolic calcium. These changes were accompanied by a reduction in the internal granularity of sporozoites, indicative of apical organelle discharge, which was confirmed by analysis of sporozoites with an exocytosis-sensitive dye. The precise timing of apical organelle discharge in the presence of a compatible host cell is critical for sporozoite attachment and invasion. Our results demonstrate for the first time how solar UV radiation can interfere with exocytosis, a fundamental cellular process in all eukaryotic cells. We contend that not only may the forecast increases in solar radiation in both aquatic and terrestrial environments significantly affect members of the Apicomplexa, solar UV-induced membrane depolarizations resulting in cytosolic calcium perturbation may affect a wider range of eukaryotic organisms through antagonistic effects on a myriad of calcium dependant cellular functions.
DOI：
10.1016/j.bbrc.2004.08.168
发表时间：
2004-10-22
影响因子：
3.1
作者：
Sikorsky, JA;Primerano, DA;Denvir, J
通讯作者：
Denvir, J
影响因子：
4.8
作者：
Brumback, AC;Lieber, JL;Betz, WJ
通讯作者：
Betz, WJ