SPECTROSCOPIC SPECIATION OF SULFUR IN LIVING MAMMALIAN CELLS: HIV & APOPTOSIS

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 硫是一种极其重要的元素，在所有生物的结构，催化和代谢中发挥作用。我们建议使用硫K边X射线吸收近边光谱监测和提高我们的理解，在哺乳动物细胞中的硫代谢，作为细胞发育的功能，并在各种刺激的反应。特别地，细胞的总体氧化还原环境和细胞器如线粒体的变化被认为在控制细胞的不同发育阶段（从增殖、分化、凋亡和最终坏死）中是重要的。这一领域的研究还处于起步阶段，关于细胞硫代谢组的直接信息将非常有价值。细胞凋亡是细胞主动自杀的过程，在许多人类疾病中非常重要，包括HIV，其中细胞凋亡的诱导是T细胞死亡的主要原因，在癌症中，细胞凋亡异常减少。细胞凋亡被认为是由细胞内的氧化还原变化引发的，尽管缺乏直接证据。这些变化应该可以通过我们提出的实验来测量，并且可以预测关于这一重要生物机制的重要信息。 我们建议使用XAS来研究活的哺乳动物细胞的培养物-MDCK永生化细胞系，其是极化的上皮细胞。我们已经开发了处理细胞培养物和记录其XAS光谱的技术和设备。我们还建立了使用硫K边X射线吸收近边光谱定量形态的硫在生活系统。现在，我们计划使用这些工具来研究硫生物化学作为细胞发育状态的函数，包括细胞凋亡和机械刺激。我们的实验应该为硫在这些过程中的作用提供有价值的见解，特别是在细胞凋亡的情况下，可能具有重要的健康相关后果。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Sulfur is a vitally important element, with roles in structure, catalysis and metabolism in all organisms. We propose to use sulfur K-edge X-ray absorption near-edge spectroscopy to monitor and to improve our understanding of sulfur metabolism in mammalian cells, as a function of cellular development and in response to various stimuli. In particular, changes in the overall redox environment of the cell, and in organelles such as mitochondria, are thought to be important in controlling different developmental stages of the cell, from proliferation, differentiation, apoptosis and finally to necrosis. Research in this area is in its infancy, and direct information on the sulfur metabolome of the cell would be very valuable. Apoptosis, the process by which cells actively commit suicide, is very important in numerous human diseases, including HIV, where induction of apoptosis is the primary cause of T-cell death, and in cancer, where apoptosis is abnormally reduced. Apoptosis is thought to be initiated by redox changes within cells, although direct evidence for this is lacking. Such changes should be measurable by the experiments that we propose, and vital information on this important biological mechanism can anticipated. We propose to use XAS to study cultures of living mammalian cells - the MDCK immortalized cell-line, which are polarized epithelial cells. We have already developed the techniques and equipment for handling the cell cultures and recording their XAS spectra. We have also established the use of sulfur K-edge X-ray absorption near-edge spectroscopy to quantitatively speciate the sulfur in living systems. Now we plan to use these tools to study sulfur biochemistry as a function of cellular developmental status including apoptosis and during mechanical stimulation. Our experiments should provide valuable insights into the role of sulfur in these processes, and particularly in the case of apoptosis, could have important health-related ramifications.