CELLULAR BIOMARKERS OF AGING

这项提案的目标是验证一组拟议的 哺乳动物衰老的生物标志物，由 NIA/NCTR生物标志物研究群体。具体目标是 应用和评价六种潜在的生物标志物作为年龄指标- Fischer 344大鼠2岁时细胞生理学的依赖性变化， 6、12、18、24和30个月龄。随意喂食的动物将被 研究了24个月龄和饮食限制的大鼠 经过30个月的学习。生物标志物有：1)血浆 大鼠膜Ca~(2+)-ATPase(钙泵)活性 红细胞及其对生理的体外反应性 甲状腺激素浓度；2)细胞质含量 钙结合调节蛋白钙调蛋白的放射免疫测定 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)细胞质膜葡萄糖转运(葡萄糖通量)活性 脂肪垫脂肪细胞和单核细胞；5)反应性，在 糖胺多聚糖合成的术语，或皮肤成纤维细胞 体外对甲状腺激素、糖皮质激素和多种生长的影响 因子(表皮生长因子、血小板衍生生长因子、 6)微量白蛋白尿(微梯度凝胶电泳法)。 除葡萄糖通量研究外，初步测量的 生物标志物将每隔1至3个月重复一次 评估，以评估可重复性并确定 个体动物的纵向变化。来自广告的结果 饲喂锂盐的动物将与饲料喂养的动物进行比较。 寿命延长的受限制的大鼠。人的感受性 Fischer 344大鼠慢性肾病需要肾小球 滤过率(GFR)被监测和推测与年龄有关 生物标志物的变化与可能的 对GFR降低的这些测量的贡献。这个 合作的调查人员已经发布了他们自己的方法 除了糖化血红蛋白外，这些生物标志物中的每一个， 申请机构已经建立了层流笼养 在其动物栖息地的专用无障碍房间内 以前在无特定病原体(SPF)屏障中饲养的啮齿动物 设施。提出的生物标记物的优点是 非致命性、最小侵入性、相对简单和 纵向应用前景展望。目前存在以下支持 建议的生物标记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.