NEUTROPHIL FUNCTION AND AGING

中性粒细胞功能与衰老

• 批准号: 3121319
• 负责人: David A Lipschitz
• 金额: $ 16.94万
• 依托单位: UNIV OF ARKANSAS FOR MED SCIS
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-09-01 至 1996-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3121319
• 关键词: G protein; aging; biological models; biological signal transduction; calcium flux; cell age; cell membrane; chemoattractants; diacylglycerols; flow cytometry; human tissue; inositol phosphates; lipid metabolism; membrane potentials; neutrophil; peptides; phosphatidylinositols; phospholipase C; receptor; receptor expression; viscosity

DESCRIPTION (adapted from the applicant's abstract): This is a revised proposal for five years of funding for the support of studies in the age-associated defect of neutrophil function in man. The Investigator proposes to continue with studies based on observations he and his coworkers have already made. The fundamental theme is the utilization of the neutrophil as a model of cellular aging, with the expectation that mechanistic studies of a defect in the function of "aged" neutrophils, previously reported and studied by the Investigator, will lead to an understanding of the widespread and various defects in cellular function which accompany aging. The experiments are planned around four specific aims: 1) to define the age-related decline in signal transduction, 2) to explain why the age-related decrements in signal transduction are greater at early steps in the pathway than later events, 3) to define whether the age-related decline in function is heterogeneous among neutrophils, and 4) to identify the reversible change in the cell membrane that accounts for the age-related decrease in receptor-mediated responses. Further studies of the turnover of phosphoinositide precursors of DAG and IP3 were planned, and considerable progress has already been made with this, as described in the supplemental material. Also planned are studies of the number of high and low-affinity fMLP receptors of young and old cells. Studies of the effect of age on G protein regulation of receptor kinetics will concentrate on Gn, a CT binding protein thought to play a role in transducing the signal from the fMLP receptor to PLC. Experiments will be based on the concept that Gn is dissociated into three subunits on activation by flvILP, and that subsequently ribolsylated. The method for quantifying the GTP-ase activity will be measured by assessing the liberation of radioactive phosphorous from labeled GTP. ability of PT to catalyze ADP-ribosylation of the alpha subunit was described by Bokoch, who will act as a collaborator in the proposed studies. He has also developed immunoblot assays for the subunits1 and the Investigator includes a letter promising Dr. Bokoch's collaboration. Studies of the activity of PLC, PLD and PLA2 activity will also be carried out. Now in other studies, FACS will be used to assess membrane potential(di-1-C5(3)), formation of oxidative products (DCF), the mobilization of calcium (indo-1 AM) -and the binding of fluorescenated flVILF. An expert collaborator, Dr. Epstein at the University of Arkansas, will aid with this. Finally, membrane microviscosity will be estimated using the fluorescent probes, DPH, PRO-DPH, A-DPH, cis-parinarate and para-parinarate. Dr. Mrak will aid with this.

描述（根据申请人的摘要改编）：这是一个修订版 提议为支持研究的五年资助 人类中性粒细胞功能的年龄相关缺陷。 调查员 建议根据他和他的观察继续进行研究 同事已经做出了。 基本主题是利用 中性粒细胞作为细胞衰老的模型，预期 缺陷在“老化”中性粒细胞功能中的机械研究， 先前由研究人员报告和研究的，将导致 了解细胞功能的广泛和各种缺陷 伴随衰老。 实验计划围绕四个特定目的：1）定义 与年龄相关的信号转导下降，2）解释为什么 在早期步骤中，与年龄相关的信号转导减少更大 路径比以后的事件，3）定义与年龄相关的下降是否下降 在功能中，中性粒细胞是异质的，4） 占与年龄有关的细胞膜的可逆变化 减少受体介导的反应。 进一步研究DAG和DAG磷酸肌醇前体的周转率 IP3计划了，并且已经取得了相当大的进步 如补充材料中所述。 还计划的是研究 年轻人和老年人的高亲和力FMLP受体的数量 细胞。 对年龄对受体调节的影响的研究 动力学将集中在GN上，GN是一种CT结合蛋白，认为可以发挥作用 在将信号从FMLP受体转传为PLC中的作用。 实验 将基于以下概念，即GN分解为三个亚基 Flvilp的激活，随后结成核糖。 方法 量化GTP-ase活性将通过评估来衡量 从标记的GTP中解放放射性磷。 PT的能力 Bokoch描述了Alpha亚基的催化ADP-核糖基化 将在拟议的研究中担任合作者。 他也发展了 亚基1和调查人员的免疫印迹测定法包括一封信 有希望博科博士的合作。 PLC活性的研究PLD 也将进行PLA2活动。 现在在其他研究中，FACS将用于评估膜 势（DI-1-C5（3）），氧化产物的形成（DCF）， 动员钙（Indo -1 AM） - 荧光烯的结合 flvilf。 阿肯色大学的专家合作者，爱泼斯坦博士， 将有助于此。 最后，将估计膜微度粘度 使用荧光探针，DPH，Pro-DPH，A-DPH，顺式 - 聚酯和 para-parinarate。 Mrak博士将帮助这一点。