Plasma Mitochondrial Peptide Assays as Biomarkers of Environmental Toxin Exposure

线粒体功能障碍与许多慢性疾病相关，线粒体是许多环境毒素的靶标，但没有经过验证的循环标志物可用于评估环境暴露导致的线粒体功能或功能障碍。线粒体包含近1000种核源蛋白质，但线粒体染色体只编码13种蛋白质。该团队最近确定了一个新的线粒体衍生肽（mdp）家族。这些包括人蛋白和六种我们命名为shlp的类人肽，它们在体外和体内有效地调节细胞存活和代谢过程。有人建议，ELISA检测循环人蛋白和其他MDPs代表线粒体功能的强大标记，并将作为与环境损害相关的线粒体功能障碍的早期指标。该项目的目标包括继续开发和表征人类和小鼠的人蛋白和shlp的ELISA检测方法。初步数据表明，在与线粒体功能障碍相关的人类疾病状态和急性阿霉素暴露的小鼠中，它们的水平异常。线粒体毒素鱼藤酮和阿霉素对细胞系和原代培养物的体外影响也将根据它们对线粒体肽的表达和产生的影响进行检查，并将其与线粒体功能的测量相关联。最后，在短期和长期研究暴露于线粒体毒素鱼藤酮和阿霉素的小鼠中，测定血浆线粒体肽水平与线粒体功能障碍之间的关系。将评估毒素暴露后MDPs循环水平的变化，并与来自牺牲动物的这些肽的器官特异性水平以及线粒体功能的体内和体外分析相关。总之，这些研究将建立循环线粒体肽测定作为环境毒素暴露导致的线粒体功能障碍标志物的效用，并将为未来研究监测暴露于此类毒素的人类创造一套关键工具。这将有助于预防和干预与线粒体功能障碍相关的亚临床阶段的疾病。

DESCRIPTION (provided by applicant): Plasma Mitochondrial Peptide Assays as Biomarkers of Environmental Toxin Exposure Mitochondrial dysfunction is associated with a number of chronic diseases and mitochondria are a target for numerous environmental toxins, but no validated circulating markers are available for assessing mitochondrial function or dysfunction resulting from environmental exposures. Mitochondria contain nearly a thousand proteins of nuclear origin, but the mitochondrial chromosome only encodes 13 proteins. This team recently identified a family of novel mitochondrial derived peptides (MDPs). These include humanin and six humanin-like peptides we named SHLPs, which potently regulate cell survival and metabolic processes in vitro and in vivo. It is proposed that ELISA assays for circulating humanin and other MDPs represent robust markers of mitochondrial function and will serve as early indicators of mitochondrial dysfunction associated with environmental insults. The goals in this project include continued development and characterization of ELISA assays for humanin and SHLPs in humans and mice. Preliminary data demonstrates abnormalities in their levels in human diseases states associated with mitochondrial dysfunction and in mice subjected to acute doxorubicin exposure. The in vitro effects of the mitochondrial toxins Rotenone and Doxorubicin on cell lines and primary cultures will also be examined in terms of their effect on the expression and production of mitochondrial peptides, and correlate this to measures of mitochondrial function. Finally a determination of the relationship between plasma levels of mitochondrial peptides and mitochondrial dysfunction, in mice exposed to the mitochondrial toxins Rotenone and Doxorubicin in short term and long-term studies. Changes will be assessed in circulating levels of MDPs following toxin exposure and correlated to organ-specific levels of these peptides from sacrificed animals as well as to in vivo and ex vivo analysis of mitochondrial function. Together, these studies will establish the utility of circulating mitochondrial peptide assays as markers of mitochondrial dysfunction resulting from environmental toxin exposure and will create a critical set of tools for future studies to monitor humans exposed to such toxins. This will enable prevention and intervention in subclinical stages of diseases related to mitochondrial dysfunction. PUBLIC HEALTH RELEVANCE: Relevance of this research to public health We have recently made the unique discovery that the mitochondria is the site of production of previously unrecognized peptides with biological activity that can be detected in the circulation. This represents a paradigm shift from the current approach to assessing mitochondrial function in health and disease. There is a great need to develop early biomarkers for mitochondrial dysfunction. This is true for both chronic diseases related to lifestyle and genetic susceptibility as well as to diseases related to environmental exposure. Our proposed studies will establish the utility of circulating mitochondrial peptide assays as markers of mitochondrial dysfunction resulting from environmental toxin exposure and will create a critical set of tools for future studies to monitor humans exposed to such toxins. This will enable prevention and early intervention in subclinical stages of diseases related to mitochondrial dysfunction. We believe that this project represents a highly responsive approach to the urgent concerns raised regarding the need for the development of assays for mitochondrial function that can be rapidly translated to clinical and population research.