REGULATION OF NEURONAL MITOSIS

神经元有丝分裂的调节

• 批准号: 6301935
• 负责人: Emanuel Murray DiCicco-Bloom
• 金额: $ 14.52万
• 依托单位: UNIV OF MED/DENT NJ-R W JOHNSON MED SCH
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-04-01 至 2001-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6301935
• 关键词: autoradiography; axon; biological signal transduction; blood brain barrier; brain cell; cell cycle; cell death; cell growth regulation; cell proliferation; cerebellum; cerebrospinal fluid; dendrites; developmental neurobiology; fibroblast growth factor; gene expression; hippocampus; laboratory rat; microscopy; neurogenesis; neuronal transport; olfactory lobe; radioimmunoassay

Our long term goal is to define mechanisms regulating generation of peripheral and central neurons from dividing precursors. Previously, we found that epigenetic factors regulate proliferation in a population- specific fashion, increasing precursor mitosis and survival. While evidence suggests that local factors control neurogenesis, our current studies indicate that distant signals also influence proliferation: 1) Dividing precursors in culture and in vivo possess "paramitotic" neurites, through which target-derived signals alter mitosis and survival; 2) Peripheral injection of bFGF stimulates brain neurogenesis, crossing rapidly the blood-brain barrier (BBB). Thus distant target signals, acting via paramitotic processes or across the BBB, may serve to coordinate body and brain growth. We will define the effects of distant signals in culture and in vivo, examining neurogenesis during ontogeny and maturity. Specifically, we will define (a) axodendritic identity and developmental expression of sympathetic neuroblast paramitotic processes, (b) paramitotic processes and target regulation and expression of cerebellar granule paramitotic processes, (d) kinetics and selectivity of peripheral bFGF transport across the BBB, (e) fate of bFGF-responsive cells in developing and mature brain, and (f) ontogenic and reparative functions of bFGF-induced neurogenesis. Our strategy employs neuronal precursors from embryonic sympathetic ganglia and postnatal brain, including cerebellum, hippocampus, olfactory bulb, and subventricular zone. Mitotic cells are assessed by incorporation of [3H] thymidine and BrdU. Cell survival, neurite outgrowth, and division are assayed by microscopy, retrograde axonal tracing, and time-lapse analysis. Cell death will be assayed by TUNEL and DNA fragmentation. Neural fate and axodendritic characters of mitotic precursors is defined by immuno-colocalization of BrdU and neuroglial antigens. Kinetics of bFGF transport into brain and CSF is detected using spectroscopy of 125I-bFGF and RIA of unlabeled factor. Long term neurogenetic effects of peripheral bFGF will be assessed biochemically and morphologically, during ontogeny and maturity, and after brain damage. By defining target and somatic regulation of proliferation, we may gain insight into mechanisms of normal ontogeny, providing new pathogenetic models. Further, we may design therapies, such as peripheral bFGF, to redress neuronal deficiencies associated with congenital, degenerative, and acquired brain disease.

我们的长期目标是定义调节生成的机制 来自分裂前体的外周和中枢神经元。此前，我们 发现表观遗传因素调节群体的增殖- 特定的方式，增加前体有丝分裂和存活。尽管 有证据表明局部因素控制神经发生，我们目前 研究表明，远距离信号也会影响增殖：1) 培养物和体内的分裂前体具有“副有丝分裂”神经突， 靶标衍生信号通过其改变有丝分裂和存活； 2） 外周注射 bFGF 刺激大脑神经发生、交叉 迅速通过血脑屏障（BBB）。因此远处的目标信号，作用 通过拟有丝分裂过程或穿过血脑屏障，可能有助于协调身体 和大脑发育。 我们将定义远距离信号在培养物和体内的影响， 检查个体发育和成熟期间的神经发生。具体来说，我们将 定义 (a) 轴突的身份和发育表达 交感神经母细胞副有丝分裂过程，(b) 副有丝分裂过程 小脑颗粒拟有丝分裂的靶调控和表达 过程，(d) 外周 bFGF 转运的动力学和选择性 穿过 BBB，(e) bFGF 反应细胞在发育和成熟过程中的命运 脑，以及 (f) bFGF 诱导的个体发生和修复功能 神经发生。 我们的策略采用来自胚胎交感神经的神经元前体 神经节和产后大脑，包括小脑、海马体、嗅觉 球部和室下区。通过掺入法评估有丝分裂细胞 [3H]胸苷和BrdU。细胞存活、神经突生长和分裂 通过显微镜、逆行轴突追踪和延时进行分析 分析。细胞死亡将通过 TUNEL 和 DNA 片段化进行测定。 有丝分裂前体的神经命运和轴突特征被定义 通过 BrdU 和神经胶质抗原的免疫共定位。 bFGF 动力学 使用 125I-bFGF 光谱检测转运至大脑和 CSF 和未标记因子的RIA。外周神经的长期神经遗传效应 bFGF 将在个体发育过程中进行生化和形态学评估 和成熟，以及脑损伤后。 通过定义增殖的目标和体细胞调节，我们可能会获得 深入了解正常个体发育机制，提供新的发病机制 模型。此外，我们可以设计疗法，例如外周bFGF，以 纠正与先天性、退行性、 并获得了脑部疾病。