METAL CHELATES IN PREVENTION OF CISPLATIN-INDUCED KIDNEY CELL DEATH

这个子项目是许多研究子项目中的一个 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来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 我们建议合成，表征，并测试几种新的金属（铜和锌）配合物的水杨酸和氨基硫醇衍生物作为催化抗氧化剂，包括广泛的活性氧（ROS），如超氧化物歧化酶（SOD），过氧化氢，过氧亚硝酸盐，和脂质过氧自由基。这类化合物中的几种化合物已显示在人类疾病的体外和体内氧化应激模型中以多种方式有效。我们的初步数据强烈表明，这些金属配合物满足预防和治疗顺铂诱导的肾毒性的许多标准，因为它们是活性，稳定和无毒的抗氧化剂。因此，我们假设铜和锌金属元素螯合物将保护肾小管上皮细胞免受顺铂损伤，因为这些螯合物具有抗氧化活性，可以抑制细胞凋亡，促进恢复。我们提出了两个具体的目标：目标1：合成和表征铜和锌金属元素螯合物。这一目标将侧重于对新的和以前已知但尚未完全表征的化合物进行化学研究。目的二：检测金属化合物在生物体系中的肾保护活性。该研究将包括（1）评估SOD模拟金属螯合物的抗凋亡活性，涉及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;（2）检查金属螯合物通过防止顺铂诱导的促凋亡Bax从细胞质到线粒体的移位来抑制凋亡的机制;（3）基于克服顺铂诱导的病理所需的金属螯合酶的SOD模拟、过氧化氢酶模拟和/或过氧化物酶模拟反应性，研究金属螯合物如何防止顺铂诱导的细胞色素c从线粒体内膜释放及其在胞质溶胶中的出现，并显著降低顺铂诱导的半胱天冬酶-3活化;和（4）测定金属螯合物对核酸内切酶G从线粒体的渗漏、其核输入和凋亡DNA片段化的影响。本提案中体外研究的合理扩展将在体内进行。更具体地说，我们计划研究SOD模拟物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，他们对研究金属螯合物和必需金属螯合物的模拟活性有着长期的兴趣和热情。

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.