NEURONAL TURNOVER IN ADULT BRAIN USING AMS FOR RETROSPECTIVE BIRTH DATING CELLS

使用 AMS 进行追溯出生约会细胞的成人大脑神经元周转

• 批准号: 7359002
• 负责人: JONAS FRISEN
• 金额: $ 3.82万
• 依托单位: UNIVERSITY OF CALIF-LAWRNC LVRMR NAT LAB
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7359002
• 关键词: NEURONAL; TURNOVER; ADULT; BRAIN; USING

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Neurogenesis is known to occur in specific regions of the adult animal brain, but the extent and comparability of neurogenesis in the adult human brain is much harder to determine, and to date largely unknown. Traditional methods used for dating cells are limited in the information they provide, or are not appropriate for human use. Thus, currently there is no method available to study cellular turnover in man. We propose to develop a method for the retrospective birth dating of cells. We are interested in using bomb pulse carbon-14 (C14) dating as a method for measuring the approximate age of specific populations of cells in the adult human brain. This method is based on establishing the proportion of the isotope C14 in genomic DNA. C14 measurements will be made using the highly sensitive accelerator mass spectrometer (AMS). After a cell has terminally differentiated it does not divide again. Since the last cell division represents the last time point when the cell synthesized DNA, its chromosomal DNA will reflect the age when the cell was born. Traditionally, the slow decay of C14 relative to other carbon species has given it a temporal resolution of many years, however due to nuclear tests in the late 1950s and early 1960s, the level of C14 in the atmosphere has increased dramatically. This level has since dropped off in an exponential fashion, allowing one to resolve C14 differences in the range of years. Because DNA has a C14 content reflective of the time when it was synthesized, establishing the C14 content of chromosomal DNA will enable us to retrospectively birth date cells, and thus establish cellular turnover. Crucial to the understanding of basic biological processes, is information about cellular turnover. As well as having an interest in normal cellular turnover, many diseases are thought to be affected in their generation of new cells. Information about cellular turnover in disease states may provide novel insights into the pathological processes of the disease, and possibly suggest new therapeutic strategies. Preliminary experiments using AMS to date C14 from horse brain DNA have yielded encouraging results. The next step is to look at how accurately AMS dates C14 from DNA extracted from horse blood, brain and teeth. Particular populations of cells will then be isolated using FACS analysis (which allows specific cell populations to be isolated e.g. one can sort for neurons using neuronal specific markers such as NeuN, ¿ tubulin or Thy1). Once this technique has been established we aim to move onto human material, and study cellular turnover in specific human pathologies. Ethical permission to obtain postmortem human material has been granted. Project update: We used this strategy to determine the age of cells in the cortex of the adult human brain, and showed that whereas non-neuronal cells are exchanged, occipital neurons are as old as the individual, supporting the view that postnatal neurogenesis does not take place in this region. Retrospective birth dating is a generally applicable strategy that can be used to measure cell turnover in man under physiological and pathological conditions. Two papers were published during the year and a third is currently under review. The neuronal cell dating work was featured on the cover of Cell.

该子项目是利用 NIH/NCRR 资助的中心拨款提供的资源的众多研究子项目之一，该子项目和研究者 (PI) 可能已从其他 NIH 来源获得主要资助，因此可以在其他 CRISP 机构中得到体现。列出的是该中心，该中心不一定是研究人员所在的机构，已知神经发生发生在成年动物大脑的特定区域，但成人大脑中神经发生的程度和可比性更难以确定和确定。日期很大程度上未知。用于细胞年代测定的传统方法所提供的信息有限，或者不适合人类使用，因此，目前没有可用于研究人类细胞更新的方法。我们有兴趣使用炸弹脉冲碳 14 (C14) 测年作为测量成人大脑中特定细胞群的大致年龄的方法，该方法基于确定基因组 DNA 中同位素 C14 的比例。 C14 测量将使用高度细胞最终分化后不会再次分裂，因为最后一次细胞分裂代表细胞合成DNA的最后时间点，因此传统上其染色体DNA将反映细胞出生的年龄。 ，C14 相对于其他碳物种的缓慢衰变使其具有多年的时间分辨率，但是由于 20 世纪 50 年代末和 1960 年代初的核试验，大气中 C14 的水平此后该水平呈指数下降，从而可以解决多年来的 C14 差异，因为 DNA 的 C14 含量反映了其合成时间，因此确定染色体 DNA 的 C14 含量将是可行的。使我们能够回顾细胞的出生日期，从而确定细胞更新对于理解基本生物过程至关重要，除了对正常细胞更新感兴趣之外，许多疾病被认为在其产生过程中受到影响。新细胞的信息。关于疾病状态下细胞更新的研究可能会为疾病的病理过程提供新的见解，并可能提出新的治疗策略，使用 AMS 来确定马脑 DNA 中的 C14 已经产生了令人鼓舞的结果，下一步是研究其准确性。 AMS 从马血、大脑和牙齿中提取的 DNA 中确定 C14，然后使用 FACS 分析分离特定的细胞群（这允许分离特定的细胞群，例如可以使用神经元特异性标记物如 NeuN、 ¿一旦这项技术建立起来，我们的目标就是转向人类材料，并研究特定人类病理学中的细胞更新。项目更新：我们使用这种策略来确定年龄。研究人员对成人大脑皮层中的细胞进行了研究，结果表明，虽然非神经元细胞可以交换，但枕叶神经元的年龄与个体一样大，这支持了出生后神经发生不会发生在该区域的观点。约会是一种普遍适用的策略，可用于测量生理和病理条件下人类的细胞更新。年内发表了两篇论文，第三篇论文目前正在审查中。