INFLUENCE OF AGING ON MITOCHONDRIAL GENE EXPRESSION FOLLOWING TRAUMA-HEMORRHAGE

描述(申请人提供)：在了解衰老过程如何改变健康和疾病中的线粒体基因表达方面有一个根本的空白。众所周知，创伤失血性休克后，尽管进行了液体复苏，但心血管功能明显下降。由于线粒体功能在这些条件下也受到抑制，有关休克后线粒体基因表达与年龄相关的变化的信息将有助于理解衰老和线粒体基因在心脏损伤中的作用，并可能制定适当的干预策略。我们的长期目标是确定休克和创伤后与年龄相关的心肌线粒体基因改变的分子基础。我们的中心假设是创伤-失血性休克导致心脏线粒体基因表达的年龄特异性病理改变，这可以在使用线粒体基因芯片的实验模型中确定。本研究的目的是开发和验证一种啮齿动物线粒体基因芯片，并用它来检测创伤失血性休克大鼠心肌线粒体基因表达的变化。为实现这一目标，将具体实现以下三个具体目标：(1)开发啮齿动物线粒体基因芯片RoMITOChip，以确定创伤-失血性休克实验模型中与年龄相关的线粒体基因表达的变化；(2)利用(I)大鼠和小鼠心肌细胞在缺氧和常氧条件下的体外模型，(Ii)小鼠固有的线粒体功能改变的模型，(Ii)检测衰老在正常大鼠和创伤-失血性休克大鼠模型线粒体基因表达谱中的作用；(3)利用RoMITOChip确定衰老在正常大鼠和创伤失血性休克大鼠模型线粒体基因表达谱中的作用。线粒体基因组上的少数基因在Affymetrix大鼠或小鼠基因芯片中不存在。我们的重点阵列RoMITO芯片将包括核基因组中对线粒体结构和功能有贡献的基因，以及线粒体DNA上的基因，统称为线粒体基因。我们将把大鼠和小鼠的线粒体基因整合到单基因芯片RoMITO芯片中，并计划使用这一工具来检测年轻成年和老年大鼠创伤出血后心肌线粒体基因表达的变化。因此，拟议的研究与NIH使命中与发展基础知识相关的部分相关，这可能有助于减轻人类疾病的负担。这项拟议的研究将在创伤-出血中衰老和心功能障碍的背景下具有重要意义，因为它有望开发一种工具，并利用它来阐明创伤-出血后老化心脏中线粒体基因的表达谱。 这项提议的目标的成功实现将阐明创伤-出血后心脏线粒体基因表达的年龄相关变化，作为该项目的一部分开发的基因芯片将在衰老和心血管研究中有更广泛的用途。

DESCRIPTION (provided by applicant): There is a fundamental gap in understanding how aging process alters mitochondrial gene expression in health and disease. It is well known that cardiovascular functions are markedly depressed following trauma-hemorrhagic shock despite fluid resuscitation. Since mitochondrial functions are also depressed under those conditions, information concerning the age related alterations in mitochondrial gene expression after shock will be useful in understanding the role of aging and mitochondrial genes in cardiac impairment and potentially devising appropriate intervention strategies. Our long-term goal is to determine the molecular basis of the age-associated alteration of cardiac mitochondrial genes following shock and trauma. Our central hypothesis is that trauma-hemorrhagic shock leads to age- specific pathological alterations in the mitochondrial gene expression in the heart, which can be determined in an experimental model using a mitochondrial gene chip. The objective of this proposal is to develop and validate a rodent mitochondrial gene chip and use it to determine the alteration in the cardiac mitochondrial gene expression in a rat model of trauma-hemorrhagic shock. This objective will be achieved by pursuing the following three specific aims: (1) develop a rodent mitochondrial gene chip, RoMITOchip, to determine age related mitochondrial gene expression changes in an experimental model of trauma-hemorrhagic shock, ( 2) validate the RoMITOchip using (i)in vitro models of rat and mouse cardiomyocytes subjected to hypoxic and normoxic conditions, (ii) mice with inherent alteration in mitochondrial function; and (3) determine the role of aging in mitochondrial gene expression profile in the normal rat and a rat model of trauma-hemorrhagic shock using RoMITOchip. The small number of genes on the mitochondrial genome is not represented in the Affymetrix rat or mouse GeneChip. The RoMITOchip, our focused array, will include genes from the nuclear genome that contribute to the mitochondrial structure and function as well as the genes on the mitochondrial DNA, together called as mitochondrial genes. We will incorporate mitochondrial genes of the rat and the mouse into the single gene chip, RoMITOchip, and plan to use this tool to determine cardiac mitochondrial gene expression changes following trauma-hemorrhage in the young adult and aged rats. Thus the proposed research is relevant to that part of NIH's mission that pertains to developing fundamental knowledge that will potentially help to reduce the burdens of human disease. The proposed research will be significant in the context of aging and cardiac dysfunction in trauma-hemorrhage, because it is expected to develop a tool and use it to elucidate the mitochondrial gene expression profile in the aging heart following trauma-hemorrhage.Narrative The successful accomplishment of the objectives of this proposal would elucidate age related changes in mitochondrial gene expression in the heart after trauma-hemorrhage and the gene chip that will be developed as part of this project will have a broader use in aging and cardiovascular research.