CELLULAR BIOMARKERS OF AGING

本提案的目的是验证一个小组的建议， 动物中哺乳动物衰老的生物标志物， NIA/NCTR生物标志物研究群体。 具体目标是 应用并评估六种潜在的生物标志物作为年龄指标- 在2， 6、12、18、24和30月龄。 自由采食动物将 研究将持续到24个月大，饮食限制的大鼠将被 研究年龄30个月。 生物标志物是：1）血浆 大鼠膜Ca ~（2+）-ATP酶（钙泵）活性 红细胞及其体外生理反应性 甲状腺激素浓度; 2）细胞质含量 （放射免疫测定）钙调素，钙结合调节 红细胞和真皮成纤维细胞中的蛋白质; 3）糖基化 红细胞血红蛋白含量（微型离子交换柱）; 4)质膜葡萄糖转运（葡萄糖通量）活性 脂肪垫脂肪细胞和单核细胞; 5）反应性， 糖胺聚糖合成，或真皮成纤维细胞， 体外对甲状腺激素、糖皮质激素及各种生长 因子（表皮生长因子，血小板衍生生长因子， 胰岛素）; 6）微量白蛋白尿（微梯度凝胶电泳）。 除了葡萄糖通量研究外， 生物标志物将以1至3个月的间隔进行重复随访， 评估，以估计再现性并确定 个体动物的纵向变化。 结果从AD 将自由采食的动物与来自饮食的动物进行比较。 寿命延长的受限老鼠 易感性 Fischer 344大鼠慢性肾病需要肾小球 滤过率（GFR）进行监测，并假定年龄相关 生物标志物的变化应与可能的变化区分开来 这些测量结果降低了GFR。 的 合作的研究人员发表了他们自己的方法， 这些生物标志物中的每一种除了糖化血红蛋白之外， 申请机构已建立层流笼 在其动物群的专用无障碍房间中， 先前在无特定病原体（SPF）屏障中饲养的啮齿动物 设施 所提出的生物标志物的优点是它们 非致命性，最小侵入性，相对简单， 纵向应用的前景。 目前支持 所提出的生物标志物与人类衰老的相关性。

The objective of this proposal is to validate a panel of proposed biomarkers of mammalian aging in animals supplied by the NIA/NCTR biomarker research colony. The specific aims are to apply and evaluate six potential biomarkers as indexes of age- dependent changes in cell physiology in the Fischer 344 rat at 2, 6, 12, 18, 24 and 30 months of age. Ad libitum fed animals will be studied through age 24 months and dietary restricted rats will be studied through age 30 months. The biomarkers are: 1) plasma membrane Ca2+-ATPase ('calcium pump') activity in rat erythrocytes and its in vitro responsiveness to physiological concentrations of thyroid hormone; 2) cytoplasmic content (radioimmunoassay) of calmodulin, a calcium-binding regulatory protein in erythrocytes and dermal fibroblasts; 3) glycosylated hemoglobin content of erythrocytes (mini-ion exchange column); 4) plasma membrane glucose transport (glucose flux) activity in fat pad adipocytes and mononuclear cells; 5) responsiveness, in terms of glycosaminoglycan synthesis, or dermal fibroblasts in vitro to thyroid hormone, glucocorticoid and to various growth factors (epidermal growth factor, platelet-derived growth factor, insulin); 6) microalbuminuria (microgradient gel electrophoresis). Except for glucose flux studies, initial measurements of biomarkers will be followed at 1-to-3 month intervals by repeated assessment in order to estimate reproducibility and determine longitudinal changes in individual animals. Results from ad libitum fed animals will be compared with those from dietary restricted rats whose lifespans are extended. Susceptibility of the Fischer 344 rat to chronic nephropathy requires that glomerular filtration rat (GFR) be monitored and that putative aged-related changes in biomarkers be distinguished from the possible contribution to these measurements of decreased GFR. The collaborating investigators have published their own methods for each of these biomarkers with the exception of glycohemoglobin, and the applicant institution has established laminar flow caging in dedicated nonbarrier rooms in its animal colony for maintaining rodents previously raised in Specific Pathogen Free (SPF) barrier facilities. The advantages of the biomarkers proposed are their nonlethality, minimal invasiveness, relative simplicity and prospect for longitudinal application. Support currently exists for relevance to human aging of the proposed biomarkers.