microRNAs and Anesthetic-Induced Developmental Neurotoxicity

microRNA 和麻醉诱导的发育神经毒性

• 批准号: 8670138
• 负责人: Xiaowen Bai
• 金额: $ 29.07万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-15 至 2019-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8670138
• 关键词: Anesthesia procedures; Anesthetics; Animal Model; Apoptosis; Attenuated; Brain; Cell Death; Child; Childhood; Complex; Data; Development; Discipline of obstetrics; Disease; Dose; Down-Regulation; Exhibits; Exposure to; Functional RNA; Gene Expression; General anesthetic drugs; Human; Knock-out; Knockout Mice; Learning Disabilities; Mediating; Medicine; MicroRNAs; Mitochondria; Molecular; Mus; Neonatal; Nerve Degeneration; Neurons; Pathologic Processes; Pathway interactions; Phase; Physiology; Play; Population; Predisposition; Pregnant Women; Process; Propofol; Proto-Oncogene Proteins c-akt; Reporting; Research; Role; Safety; Sedation procedure; Signal Pathway; Stem cells; Testing; Time; Translating; Up-Regulation; Wild Type Mouse; base; cell type; clinically relevant; developmental neurotoxicity; human embryonic stem cell; innovation; long term memory; loss of function; mitochondrial permeability transition pore; nervous system disorder; neuron loss; neuroprotection; neurotoxic; neurotoxicity; novel; overexpression; prevent; public health relevance; synaptogenesis

PROJECT ABSTRACT Growing evidence demonstrates that prolonged exposure to general anesthetics induces widespread neuronal cell death followed by long-term memory and learning disability in animal models, raising serious concerns about the safety of obstetric and pediatric anesthesia. Although the underlying mechanisms of increased anesthetic-induced neurotoxicity are complex and just beginning to be understood, our exciting preliminary data point to the role of microRNAs in neurotoxicity. MicroRNAs are endogenous, small, non- coding RNAs that are powerful regulators in normal development and physiology, and diseases through inhibition of target gene expression. Specifically, miR-21 has been shown to decrease apoptosis in varying cell types. Based on our preliminary data and previous reports by others, we hypothesized that the increased mitochondrial fission conferred by downregulated miR-21 contributes to the anesthetic (propofol) neurotoxicity. Propofol is most widely used for sedation and anesthesia in pediatric and obstetric medicine. We propose to utilize gain- and loss-of-function approaches to examine the role of miR-21 in propofol neurotoxicity in mice, translate the findings to humans using stem cell-derived neurons, and investigate the following molecular mechanisms underlying the roles of miR-21 effect: miR-21 targets and suppresses programmed cell death 4 (PDCD4), which can: 1) activate protein kinase B (Akt), 2) decrease mitochondrial fission, delay opening of mitochondrial permeability transition pore (mPTP), and 3) reduce cell death. Downregulated miR-21, upregulated PDCD4, attenuated activation of Akt, and increased mitochondrial fission are likely to contribute to the neurotoxicity conferred by propofol. Our initial exciting data indicate that propofol causes downregulation of miR-21 in stem cell-derived human neurons. In addition, miR-21 knockout increases the vulnerability of mouse developmental neurons and human neurons to propofol exposure. Overexpression of miR-21 attenuated propofol-induced apoptosis in cultured human neurons. Moreover, the reduction of miR-21 is accompanied with a decrease of Akt activation, an increase of mitochondrial fission, and an increase in mPTP opening in human neurons, strongly supporting our hypothesis. We propose the following Specific Aims for the next five years to test our hypotheses: 1) to examine the role of miR-21 in propofol neurotoxicity in mouse brains; 2) to determine the role of miR-21 in propofol neurotoxicity in human neurons; and 3) to determine the role of miR-21/PDCD4/mitochondrial fission pathway in propofol neurotoxicity in human neurons and mouse brains. This is a highly clinically relevant study that is innovative and at the forefront in this field. Based on the findings from this proposed study, we can develop more rational neuroprotection strategies, leading to major advances toward assuring the safety of anesthesia in pediatric populations.

项目摘要 越来越多的证据表明，长时间暴露于全身麻醉药会引起广泛的 在动物模型中，神经元细胞死亡，随后出现长期记忆和学习障碍， 对产科和儿科麻醉安全性的担忧。虽然潜在的机制 增加麻醉诱导的神经毒性是复杂的，刚刚开始被理解，我们令人兴奋的 初步数据指出了microRNA在神经毒性中的作用。microRNA是内源性的，小的，非- 编码RNA是正常发育和生理学以及疾病的强大调节因子， 抑制靶基因表达。具体而言，已经显示miR-21减少不同细胞中的细胞凋亡。 类型根据我们的初步数据和其他人以前的报告，我们假设， 由下调的miR-21引起的线粒体分裂导致麻醉剂（丙泊酚）神经毒性。 异丙酚最广泛地用于儿科和产科医学中的镇静和麻醉。我们建议 利用获得和丧失功能的方法来检查miR-21在小鼠丙泊酚神经毒性中的作用， 使用干细胞衍生的神经元将这些发现转化为人类，并研究以下分子 miR-21作用的潜在机制：miR-21靶向并抑制程序性细胞死亡4 （PDCD 4），其可以：1）激活蛋白激酶B（Akt），2）减少线粒体分裂，延迟线粒体开放。 线粒体通透性转换孔（mPTP），和3）减少细胞死亡。下调miR-21， PDCD 4上调、Akt活化减弱和线粒体分裂增加可能有助于 异丙酚的神经毒性 我们最初的令人兴奋的数据表明，异丙酚导致干细胞来源的人miR-21下调， 神经元此外，miR-21敲除会增加小鼠发育神经元和人类的脆弱性 神经元对异丙酚暴露的反应miR-21过表达减弱丙泊酚诱导的体外培养人肝癌细胞凋亡 人类神经元此外，miR-21的减少伴随着Akt活化的减少， 线粒体分裂的增加，以及人类神经元中mPTP开放的增加，强烈支持我们的研究。 假说.我们提出了未来五年的具体目标，以验证我们的假设：1） 检查miR-21在小鼠脑中丙泊酚神经毒性中的作用; 2）确定miR-21在 丙泊酚在人神经元中的神经毒性;以及3）确定miR-21/PDCD 4/线粒体分裂的作用 异丙酚在人类神经元和小鼠脑中的神经毒性通路。这是一项高度临床相关的研究 这是创新的，在这个领域的最前沿。根据这项研究的结果，我们可以 制定更合理的神经保护策略，从而在确保安全性方面取得重大进展。 小儿麻醉