AGE RELATED CHANGE IN ANGIOTENSIN RECEPTORS AND ITS ROLE IN CHRONIC INFLAMMATION

描述(申请人提供)：衰老与炎症增强有关。血管紧张素受体AT1R和AT2R之间比例的改变会导致动物模型的炎症反应。关于衰老对人类AT1R和AT2R表达的影响，以及AT1R和AT2R的变化对老年人炎症增加的贡献，以前没有研究过。我们的初步证据表明，虚弱的老年人AT1R表达上调，AT2R表达下调，并与IL6参与了这种失衡。我们假设人类的虚弱衰老与免疫系统细胞中AT1R的上调和AT2R的表达和功能下调有关。我们推测，这些受体的改变有助于老年人免疫系统细胞吞噬能力的降低和炎性细胞因子的产生，这将进一步加剧AT1R和AT2R表达的差异。为了验证这些假设，我们提出了一项关于AT1R和AT2R的全面研究，使用来自年轻、健康的成年人(20-30岁)的免疫系统细胞(淋巴细胞和单核细胞)和四个对照组，包括(1)强壮的老年人(70-90岁)，(2)使用AT1R阻滞剂治疗的强壮的老年人(70-90岁)，(3)虚弱的老年人(70-90岁)，(4)虚弱的老年人(70-90岁)使用AT1R阻滞剂治疗。1.采用Q-PCR、免疫印迹、共聚焦显微镜、流式细胞术和Bio-Plex磷蛋白细胞信号分析技术，检测青年对照组(20-30岁)和四个对照组(每组33只)免疫细胞AT1R和AT2R基因表达、蛋白质合成和信号通路的变化。2.用AT1R和/或AT2R特异性阻滞剂孵育相同个体的免疫系统细胞，并在治疗前和治疗后用吞噬试验测定单核细胞吞噬功能的变化，以评估血管紧张素受体拮抗剂对单核细胞吞噬功能的年龄相关性差异和贡献(S)。3.通过将相同个体的免疫系统细胞与AT1R和/或AT2R阻滞剂孵育，并在治疗前和治疗后用ELISA法和Bio-Plex细胞因子测定法测定细胞因子，评估AT1R和AT2R对老年人细胞因子产生的贡献(S)。4.通过将同一受试者的免疫系统细胞与IL-6孵育，评估炎症对AT1R和AT2R表达和功能的反馈作用。采用定量聚合酶链式反应(Q-PCR)和免疫印迹法(Western印迹)定量检测IL-6对AT1R和AT2R表达的影响。 公共卫生相关性：这项研究旨在评估可能在老年虚弱、发病率和死亡率增加中发挥作用的特定因素。血管紧张素受体1和2(AT1R和AT2R)存在于几乎所有人类细胞的表面和内部。这项研究将评估随着人们年龄的增长，免疫系统细胞中这些受体之间的关系，并确定这些变化可能如何影响慢性炎症、虚弱和老年脆弱性。

DESCRIPTION (provided by applicant): Aging is associated with enhanced inflammation. An altered ratio between angiotensin receptors AT1R and AT2R results in induction of inflammation in animal models. The effects of aging on the expression of AT1R and AT2R in humans and the contribution of changes in AT1R and AT2R to increased inflammation in the older have not been previously studied. Our preliminary evidence suggests that frail older adults have up-regulation of AT1R, down-regulation of AT2R expression and implicate for IL6 in this imbalance. We hypothesize that human frail aging is associated with up-regulation of AT1R and down-regulation of AT2R expression and function in immune system cells. We hypothesize that these receptor changes contribute to decreased immune system cells phagocytic capacity and to the increased production of inflammatory cytokines in older individuals which will further heighten the divergence in AT1R and AT2R expression. In order to test these hypotheses, we propose a comprehensive study of AT1R and AT2R using immune system cells (lymphocytes and monocytes) from young, healthy adults (age 20-30) and four comparison groups that consist of (1) robust, older adults (age 70-90), (2) robust, older adults (age 70-90) treated with AT1R blockers, (3) frail, older adults (age 70-90), (4) frail, older adults (age 70-90) treated with AT1R blockers. From these subjects we will collect lymphocytes and monocytes that will be utilized for the following proposed studies: 1. Measure changes in gene expression, protein synthesis, and signaling pathways of AT1R and AT2R in immune system cells from young control (20-30Y) and the four comparison groups (N=33 in each group) using Q-PCR, western blot, confocal microscopy, flow cytometry and Bio-Plex Phosphoprotein Cellular Signaling Assays. 2. Evaluate age-related difference and contribution of Angiotensin receptors blockade to monocytes phagocytic function by incubating immune system cells from the same individuals with specific AT1R and/or AT2R blockers and measuring changes in monocytes phagocytic function with Phagocytosis Assay at baseline and in response to treatment(s). 3. Evaluate contribution of AT1R and AT2R to cytokine production in the older individuals by incubating immune system cells from the same individuals with specific AT1R and/or AT2R blockers and measuring cytokines with ELISA and Bio-Plex cytokine assays at baseline and in response to treatment(s). 4. Assess the feedback of inflammation on AT1R and AT2R expression and function by incubating immune system cells from the same subjects with IL-6. Q-PCR and western blot will be used to quantify the change in expression of AT1R and AT2R in response to IL-6 treatment. PUBLIC HEALTH RELEVANCE: This study is designed to evaluate specific factors that may play a role in late life weakness, increased morbidity and mortality. Angiotensin receptors 1 and 2 (AT1R and AT2R) are found on the surface and on the inside of virtually all human cells. This study will evaluate the relationships among these receptors in immune system cells as people age, and determine how these changes might influence chronic inflammation, frailty and late life vulnerability.