Germinal matrix hemorrhage affects glutamatergic neurogenesis

生发基质出血影响谷氨酸能神经发生

• 批准号: 8804293
• 负责人: PRAVEEN BALLABH
• 金额: $ 35.22万
• 依托单位: NEW YORK MEDICAL COLLEGE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8804293
• 关键词: Affect; Apoptosis; Autistic Disorder; Autopsy; Brain; Brain hemorrhage; Cells; Cerebral Palsy; Cerebral Ventricles; Cerebral cortex; Cerebrum; Complication; Data; Development; Dorsal; Epilepsy; Evaluation; Exhibits; Fetus; Generations; Genes; Gestational Age; Glutamates; Glycerol; Growth; Health; Hemorrhage; Human; Infant; Interneurons; Learning Disabilities; Mental Retardation; Modeling; Neocortex; Nervous System Physiology; Neurodevelopmental Disorder; Neuroglia; Neurologic; Neurons; Notch and Wnt Signaling Pathway; Oryctolagus cuniculus; Pathway interactions; Perinatal subependymal hemorrhage; Pregnancy; Premature Infant; Proliferating; Radial; Signal Pathway; Signal Transduction; Survivors; Telencephalon; Testing; United States; Ventricular; brain cell; density; excitatory neuron; hippocampal pyramidal neuron; inhibitory neuron; intraventricular hemorrhage; morphogens; nerve stem cell; neurobehavioral; neurobehavioral test; neurogenesis; neuron development; notch protein; postnatal; premature; progenitor; pup; research study; subventricular zone; transcription factor

DESCRIPTION (provided by applicant): Germinal matrix hemorrhage (GMH)-intraventricular hemorrhage (IVH) is a major complication of premature infants that results in cerebral palsy, mental retardation, learning disabilities, neurodevelopmental delay, and reduced cortical growth. Glutamatergic neurogenesis-formation of glutamatergic neurons-is orchestrated in the dorsal ventricular (VZ) and subventricular zones (SVZ) of the cerebral cortex, and continues until 28 weeks of gestational age. As IVH typically initiates in the periventricular germinal zone, this might hamper glutamatergic neurogenesis. Therefore, we ask whether IVH disrupts glutamatergic neurogenesis and the organization of the upper cortical layers (2-4) and if so, how this can be restored. During the development of the cerebral cortex, glutamatergic neurons develop from radial glia (Sox2+) of the VZ, which undergo asymmetric division to generate intermediate progenitors (IPC). IPC migrate to the SVZ to further proliferate and mature into pyramidal neurons that form the layers of cortex. Glutamatergic neurogenesis in the dorsal SVZ is orchestrated under the influence of graded expression of transcription factors including Pax6, Ngn1/2, Emx1/2, and Insm1, while neuronal specification of upper cortical layers is regulated by Cux1, Brn2, and Satb2. These transcription factors are controlled by Wnt and Notch signaling pathways. These signaling cascades are the central regulators of proliferation and differentiation of neural progenitor cells; and these morphogens determine the transcriptional activity that modifies cell fate. Our preliminary data revealed that IVH suppressed glutamatergic neurogenesis, activated Notch, and downregulated Wnt signaling. Therefore, we hypothesize that i) IVH will disrupt glutamatergic neurogenesis and the growth of the upper cortical layers, and that ii) modulation of the Wnt or Notch pathway will restore the development of glutamatergic neurons and cortical layers in preterm pups with IVH. Our approach is to employ our preterm rabbit model of glycerol-induced IVH and use autopsy materials from preterm infants. Aim #1: Evaluate a) the density, proliferation, and apoptosis of radial glia (Sox2+) and IPC (Tbr2+) in the cortical VZ and SVZ, b) the abundance of pyramidal neurons (Cux1+, Brn2+) in cortical layers 2-4, and c) neurological function in premature rabbit pups with IVH vs. pups without IVH. Validate rabbit data in humans by performing parallel experiments in human premature infants (autopsy materials) with and without IVH. Aim #2: Determine the effect of activating Wnt/b-catenin signaling pathways on a) the density, proliferation, and apoptosis of radial glia and IPC, b) neuronal density in cortical layers 2-4, and c) proneural transcription factors--Pax6, Ngn1/2, Emx1/2 and Insm1, and d) neurological function in treated pups with IVH vs. controls. Aim #3: Determine the effect of Notch inhibition on a) the density, proliferation, an apoptosis of radial glia and IPC of the VZ and SVZ, b) the density of neurons in cortical layers 2-4, c) proneural transcription factors-- Hes1/5, Pax6, Ngn1/2, and Insm1, and d) neurological function in treated pups with IVH vs. vehicle controls.

描述（申请人提供）：生发基质出血（GMH）-脑室内出血（IVH）是早产儿的主要并发症，导致脑瘫、智力低下、学习障碍、神经发育迟缓和皮质生长减少。谷氨酸能神经发生——谷氨酸能神经元的形成——在大脑皮层的背室 (VZ) 和室下区 (SVZ) 中精心策划，并持续到胎龄 28 周。由于 IVH 通常始于脑室周围生发区，这可能会阻碍谷氨酸能神经发生。因此，我们想知道 IVH 是否会破坏谷氨酸能神经发生和上皮质层的组织 (2-4)，如果是，如何恢复。 在大脑皮层发育过程中，谷氨酸能神经元从 VZ 的放射状胶质细胞 (Sox2+) 发育而来，经过不对称分裂产生中间祖细胞 (IPC)。 IPC 迁移到 SVZ，进一步增殖并成熟为形成皮质层的锥体神经元。背侧 SVZ 的谷氨酸神经发生是在 Pax6、Ngn1/2、Emx1/2 和 Insm1 等转录因子分级表达的影响下精心策划的，而上皮质层的神经元规范则受 Cux1、Brn2 和 Satb2 的调节。这些转录因子由 Wnt 和 Notch 信号通路控制。这些信号级联是神经祖细胞增殖和分化的中心调节因子。这些形态发生素决定了改变细胞命运的转录活性。我们的初步数据显示，IVH 抑制谷氨酸能神经发生、激活 Notch 并下调 Wn​​t 信号传导。因此，我们假设 i) IVH 将破坏谷氨酸能神经发生和上皮质层的生长，ii) Wnt 或 Notch 通路的调节将恢复患有 IVH 的早产幼犬谷氨酸能神经元和皮质层的发育。我们的方法是采用甘油诱导的 IVH 早产兔模型并使用早产儿的尸检材料。目标 #1：评估 a) 皮质 VZ 和 SVZ 中放射状胶质细胞 (Sox2+) 和 IPC (Tbr2+) 的密度、增殖和凋亡，b) 皮质 2-4 层中锥体神经元 (Cux1+、Brn2+) 的丰度和 c) 患有 IVH 的早产兔幼崽与没有 IVH 的幼崽的神经功能。通过对患有或不患有 IVH 的人类早产儿（尸检材料）进行平行实验来验证兔子在人类中的数据。目标 #2：确定激活 Wnt/b-连环蛋白信号通路对 a) 放射状胶质细胞和 IPC 的密度、增殖和凋亡，b) 皮质层 2-4 中的神经元密度，以及 c) 原神经转录因子的影响 - -Pax6、Ngn1/2、Emx1/2 和 Insm1，以及 d) 接受治疗的 IVH 幼犬与对照组的神经功能。目标 #3：确定 Notch 抑制对 a) VZ 和 SVZ 的放射状胶质细胞和 IPC 的密度、增殖和凋亡，b) 皮质层 2-4 中神经元的密度，c) 原神经转录因子的影响- Hes1/5、Pax6、Ngn1/2 和 Insm1，以及 d) 接受 IVH 治疗的幼犬与媒介物对照的神经功能。