METAL CHELATES IN PREVENTION OF CISPLATIN-INDUCED KIDNEY CELL DEATH

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 我们建议合成、表征和测试几种新的水杨酸和氨基硫醇衍生物的金属(铜和锌)配合物，作为催化抗氧化剂，清除广泛的活性氧物种(ROS)，如超氧化物歧化酶(SOD)、过氧化氢、过氧亚硝酸根和脂质过氧基。在人类疾病的体外和体内氧化应激模型中，这类化合物中的几种化合物已被证明以各种方式有效。我们的初步数据有力地表明，这些金属络合物符合预防和治疗顺铂肾毒性的许多标准，因为它们是活性、稳定和无毒的抗氧化剂。因此，我们推测铜和锌金属元素络合物可以保护肾小管上皮细胞免受顺铂的损伤，因为这些络合物具有抗氧化活性，可以抑制细胞凋亡，促进修复。我们提出了两个具体的目标：目标1：合成和表征铜、锌金属络合物。这一目标将侧重于对新的和以前已知的但尚未完全表征的化合物的化学研究。目的2：检测金属化合物在生物系统中的肾脏保护活性。这项研究将涉及(1)关于金属螯合物可以防止顺铂诱导的近端小管细胞死亡的细胞机制的评估，(1)关于金属螯合物的抗凋亡活性的评估；(2)金属螯合物通过阻止顺铂诱导的促凋亡的Bax从胞浆转移到线粒体而抑制细胞凋亡的机制；(3)金属螯合物如何防止顺铂诱导的细胞色素c从线粒体膜内释放并出现在胞浆中，以及如何显著降低顺铂诱导的caspase-3的激活，这是基于克服顺铂诱导的病理所需的金属螯合酶的模拟SOD、模拟过氧化氢酶和/或模拟过氧化物酶的反应；以及(4)测定金属螯合物对线粒体核酸内切酶G泄漏、其核输入和凋亡DNA片段化的影响。在体外进行的这项研究的合乎逻辑的扩展将在体内扩展。更具体地说，我们计划研究模拟超氧化物歧化酶和金属螯合物对顺铂诱导的生物系统提供保护的机制。对于这些研究，我们将与UAMS的研究人员合作，他们长期以来一直对研究金属螯合物和基本金属螯合物的模拟活性感兴趣。

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. We propose to synthesize, characterize, and test several new metal (Cu and Zn) complexes of salicylic acid and aminothiol derivatives as catalytic antioxidants that scavenge a wide range of reactive oxygen species (ROS), such as superoxide dismutase (SOD), hydrogen peroxide, peroxynitrite, and lipid peroxyl radicals. Several compounds in this class have been shown to be efficacious in a variety of ways in in vitro and in vivo oxidative stress models of human diseases. Our preliminary data strongly indicate that these metal complexes satisfy many of the criteria for prevention and treatment of cisplatin-induced nephrotoxicity, as they are active, stable, and nontoxic antioxidants. Thus, we hypothesize that Cu- and Zn-metallo-element chelates will protect kidney tubular epithelial cells from cisplatin injury because these chelates have antioxidant activity, and can suppress apoptosis and facilitate recovery. We propose two specific aims: Aim 1: Synthesize and characterize the Cu- and Zn-metalloelement chelates. This aim will focus on chemical studies of new and previously known but not fully characterized compounds. And Aim 2: Test the nephroprotective activity of the metallocompounds in biological systems. The study will involve (1) an assessment of antiapoptotic activity of the SOD-mimetic metal chelates with regard to cellular mechanisms by which metal chelates may prevent cisplatin-induced proximal tubule cell death; (2) an examination of the mechanism by which metal chelates suppress apoptosis by preventing cisplatin-induced translocation of proapoptotic Bax from the cytosol to the mitochondria; (3) a study of how metal chelates prevent cisplatin-induced cytochrome c release from the inner mitochondrial membrane and its appearance in the cytosol, and significantly reduces cisplatin-induced caspase-3 activation, based on the SOD-mimetic, catalase-mimetic, and/or peroxidase-mimetic reactivities of metal chelate enzymes required to overcome cisplatin-induced pathology; and (4) a determination of the effects of metal chelates on endonuclease G leakage from mitochondria, its nuclear import, and apoptotic DNA fragmentation. A logical extension of the studies in this proposal carried out in vitro will be extended in vivo. More specifically, we plan to study the mechanisms by which the SOD-mimetic and metal chelates offer protection to cisplatin-induced biological system. For these studies, we will collaborate with investigators at UAMS who have a long-standing interest and enthusiasm in studying metal chelates and mimetic activities of essential metal chelates.