p75 Expression for Assessing Neurotoxicity

用于评估神经毒性的 p75 表达

• 批准号: 6604046
• 负责人: WILLIAM M VALENTINE
• 金额: $ 15.1万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2005-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6604046
• 关键词: Schwann cells; blood chemistry; cell morphology; cisplatin; cytotoxicity; drug adverse effect; electron microscopy; enzyme linked immunosorbent assay; genetic transcription; growth factor receptors; immunocytochemistry; laboratory rat; light microscopy; messenger RNA; nerve growth factors; nerve injury; neurogenetics; neurotoxicology; peripheral nervous system; polymerase chain reaction; receptor expression; sciatic nerve; surface plasmon resonance; thiocarbamate; toxicant screening; urinalysis

DESCRIPTION (provided by applicant): Neurotoxicity is a common dose limiting or significant side effect of many chemotherapeutic agents emphasizing the importance of assessing neurotoxicity in the screening of novel chemotherapeutic agents. Current methods of screening for neurotoxicity typically utilize morphologic endpoints. The cost and resource requirements of these methods limits the number of chemicals that can be evaluated and the utility of these assessments is diminished by their inherent sensitivity and difficulty in obtaining quantitative data. Previous work has demonstrated up regulation of several genes following toxic insults and physical injury to the peripheral nervous system. The low affinity nerve growth factor receptor (p75) has been most extensively characterized and has exhibited the greatest increases and longest duration of elevated expression after injury. The ability to detect elevations in mRNA prior to the onset of structural changes together with the ability to assess changes along the entire axon suggest that up regulation of p75 may provide a more sensitive index of neurotoxicity than morphological endpoints. The proposed project is based upon the hypothesis that elevated p75 expression in the peripheral nervous system is a general response to toxic insult that is quantifiable and precedes the onset of morphological changes. This hypothesis will be tested through exposing rats to neurotoxic agents that selectively target the neuron, axon or Schwann cell and then determining if elevated p75 transcription precedes the onset of structural changes at the light and electron microscope level. The quantity of p75 mRNA will be determined in peripheral nerve using real time RT-PCR and the levels of p75 protein in nerve evaluated using immunohistochemistry. The utility of measuring truncated p75 in plasma and urine to I detect neurotoxtcity will also he determined by ELISA and plasmon resonance. Morphologic assessments will he used to determine the temporal relationship of p75 expression to the onset of structural changes. The significance of these investigations lies in the development of more efficient and sensitive methods for detecting neurotoxicity of new therapeutic agents, monitoring neurotoxicity in patients during therapy, defining bioactivation pathways of neurotoxic agents and assessing the neurotoxicity of environmental compounds. The benefits of these methods can be realized through facilitating development of new therapeutic agents and recognizing neurotoxic chemicals before the occurrence of human neurotoxicity.

描述（由申请人提供）：神经毒性是许多化疗药物的常见剂量限制或显著副作用，强调了在筛选新型化疗药物时评估神经毒性的重要性。目前的神经毒性筛选方法通常利用形态学终点。这些方法所需的费用和资源限制了可供评价的化学品的数量，而且这些评估的实用性也因其固有的敏感性和难以获得定量数据而降低。先前的工作已经证明了在对周围神经系统的毒性损伤和物理损伤后几个基因的上调。低亲和力神经生长因子受体（p75）已被最广泛的特点，并表现出最大的增加和损伤后的表达升高的持续时间最长。在结构变化发生之前检测mRNA升高的能力以及评估整个轴突沿着变化的能力表明，p75的上调可能提供比形态学终点更敏感的神经毒性指标。拟议的项目是基于这样的假设，即外周神经系统中p75表达升高是对毒性损伤的一般反应，是可量化的，并且在形态学变化发生之前。这一假设将通过将大鼠暴露于选择性靶向神经元、轴突或许旺细胞的神经毒性剂，然后确定p75转录升高是否先于光镜和电镜水平的结构变化的发生来进行测试。采用真实的时间RT-PCR法检测周围神经中p75 mRNA的表达量，采用免疫组化法检测周围神经中p75蛋白的表达水平。还将通过ELISA和等离子体共振测定血浆和尿液中截短的p75以检测神经毒性的效用。形态学评估将用于确定p75表达与结构变化发生的时间关系。这些研究的意义在于开发更有效和灵敏的方法来检测新治疗药物的神经毒性，监测治疗过程中患者的神经毒性，确定神经毒性药物的生物活化途径和评估环境化合物的神经毒性。这些方法的益处可以通过促进新治疗剂的开发和在人类神经毒性发生之前识别神经毒性化学品来实现。