THE ROLE OF PTEN IN MICROGLIAL PATHOBIOLOGY AFTER EXPOSURE TO REPETITIVE MILD TBI

PTEN 在反复轻度 TBI 暴露后微胶质病理学中的作用

基本信息

批准号：
10683340
负责人：
Joseph O Ojo
金额：
$ 16.34万
依托单位：
ROSKAMP INSTITUTE, INC.
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-08-15 至 2024-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10683340
关键词：
Address Alzheimer&apos s disease related dementia Alzheimer&apos s disease risk Animal Model Astrocytes Automobile Driving Autophagocytosis Autopsy Biochemical Markers Bioenergetics Blood - brain barrier anatomy Blood Vessels Cell Survival Cells Chronic Clinical Clinical Trials Consultations Cre-LoxP Cytokine Signaling Data Development Disease Disease associated microglia Ensure Event Exposure to Future Genes Goals Human Inflammation Inflammatory Inflammatory Response Injury Intervention Investigation Learning Lipids Mediating Memory Microglia Modeling Molecular Bank Myeloid Cells Nerve Degeneration Nervous System Trauma Neurodegenerative Disorders Neurologic Deficit Neurologic Dysfunctions Neurons Outcome PIK3CG gene PTEN gene Pathogenesis Pathology Patients Performance Phenotype Phosphoric Monoester Hydrolases Pilot Projects Play Pre-Clinical Model Research Design Retrospective Studies Risk Factors Role Sensorimotor functions Signal Transduction Specificity Synapses TBI Patients Tamoxifen Therapeutic Time astrogliosis axon injury brain cell cell type density functional outcomes genetic signature human model inhibitor lipid metabolism mild traumatic brain injury mouse model neurobehavioral neuroinflammation neuropathology neuroprotection new therapeutic target novel pharmacologic pre-clinical prevent prophylactic response response to injury single cell analysis tau Proteins therapeutic target timeline transcriptomics translational potential treatment strategy

项目摘要

Repetitive mild traumatic brain injury (r-mTBI) is one of the strongest risk factors for developing neurodegenerative diseases. To date, no disease modifying therapies have been developed to prevent the long- term consequences of TBI. There is a need to advance our current understanding of the cellular mechanisms driving the long-term neurological deficits after TBI, as this could lead to the identification of novel therapeutic targets. Neuroinflammation mediated by resident microglia is a common feature of human and animal models of TBI. Factors governing the propagation and persistence of disease associated microglial responses in the chronic sequelae of TBI remain elusive. We have established a mouse model of r-mTBI that recapitulates many features of human TBI and thus represents a translationally relevant preclinical platform. From this model we have generated a molecular library of microglia gene profiles, at a range of timepoints post-injury that provides a unique and detailed time-course of the microglial neuroinflammatory response to r-mTBI. Particularly, we reveal deficits in energy bioenergetics, cytokine signaling, lipid metabolism, and a pro-inflammatory signature of microglia at chronic timepoints, which appear to be driven by the activation of Phosphatase and Tensin Homolog (PTEN) signaling. PTEN is a lipid phosphatase that antagonizes phosphatidylinositol 3-Kinase signaling, a critical node vital for regulating cell survival, energy bioenergetics, autophagy and inflammation. PTEN is highly expressed in myeloid cells, and its dysregulation can trigger the activation of inflammatory responses. Multiple cell types express PTEN, thus PTEN inhibitors lack the specificity needed to target PTEN signaling in microglia. In a pilot study, we have shown that PTEN deletion in myeloid cells after 1 mo dampens disease associated microglial responses and proinflammatory signature in our model. In this new application, we plan to extend these studies to further clarify the role of PTEN in regulating microglia responses in the context of TBI and demonstrate whether microglia specific PTEN deletion can mitigate TBI mediated neuroinflammation/neurodegeneration and chronic functional outcomes. We will compare TBI- dependent responses in the presence or absence of PTEN deletion to reveal microglial specific targets that correlate with favorable outcomes after r-mTBI and represent novel therapeutic targets. We will achieve this by utilizing a tamoxifen inducible mouse model that will specifically target PTEN deletion in microglia and not other myeloid cells (Hexbcre+/PTENfl/fl). We will induce PTEN deletion using three therapeutic time-windows (i.e., pre-injury, early and delayed), and examine functional and pathobiological outcomes, scRNAseq profiles and functional activities of microglia at 6 mo post-injury. Our goal is to clarify the role of PTEN as a negative regulator of microglial pathobiology in the chronic sequelae of r-mTBI, and to identify unique gene signatures and reparative mechanisms in microglia induced by PTEN deletion that can be explored as novel microglial specific targets in TBI and other neurodegenerative diseases where neuroinflammation is a critical contributor.

重复性轻度创伤性脑损伤 (r-mTBI) 是罹患该病的最强危险因素之一神经退行性疾病。迄今为止，尚未开发出疾病修饰疗法来预防长期疾病 TBI 的长期后果。有必要增进我们目前对细胞机制的理解导致 TBI 后的长期神经功能缺损，因为这可能导致新的治疗方法的确定目标。由驻留小胶质细胞介导的神经炎症是人类和动物模型的共同特征脑外伤性脑损伤 (TBI)。控制疾病相关小胶质细胞反应的传播和持续性的因素 TBI 的慢性后遗症仍然难以捉摸。我们建立了 r-mTBI 小鼠模型，该模型概括了许多人类 TBI 的特征，因此代表了一个翻译相关的临床前平台。从这个模型我们已经在损伤后的一系列时间点生成了小胶质细胞基因谱的分子库，提供了小胶质细胞对 r-mTBI 神经炎症反应的独特而详细的时间过程。特别是，我们揭示能量生物能学、细胞因子信号传导、脂质代谢和促炎症特征的缺陷小胶质细胞在慢性时间点的变化，这似乎是由磷酸酶和张力蛋白的激活驱动的同源 (PTEN) 信号传导。 PTEN 是一种脂质磷酸酶，拮抗磷脂酰肌醇 3-激酶信号传导是调节细胞生存、能量生物能学、自噬和炎症至关重要的关键节点。 PTEN在骨髓细胞中高表达，其失调可引发炎症反应的激活回应。多种细胞类型表达 PTEN，因此 PTEN 抑制剂缺乏靶向 PTEN 所需的特异性小胶质细胞中的信号传导。在一项初步研究中，我们发现 1 个月后骨髓细胞中的 PTEN 缺失在我们的模型中抑制疾病相关的小胶质细胞反应和促炎症特征。在这个新的应用，我们计划扩展这些研究，以进一步阐明 PTEN 在调节小胶质细胞中的作用 TBI 背景下的反应并证明小胶质细胞特异性 PTEN 缺失是否可以减轻 TBI 介导的神经炎症/神经变性和慢性功能结果。我们将比较 TBI- 在存在或不存在 PTEN 缺失的情况下进行依赖性反应，以揭示小胶质细胞特异性靶标与 r-mTBI 后的良好结果相关，并代表新的治疗靶点。我们将通过以下方式实现这一目标利用他莫昔芬诱导小鼠模型，该模型将特异性针对小胶质细胞中的 PTEN 缺失，而不是其他骨髓细胞 (Hexbre+/PTENfl/fl)。我们将使用三个治疗时间窗诱导 PTEN 缺失（即损伤前、早期和延迟），并检查功能和病理生物学结果、scRNAseq 概况以及损伤后 6 个月小胶质细胞的功能活动。我们的目标是阐明 PTEN 作为负面因素的作用 r-mTBI 慢性后遗症中小胶质细胞病理学的调节因子，并鉴定独特的基因特征 PTEN 缺失诱导的小胶质细胞的修复机制，可作为新型小胶质细胞进行探索 TBI 和其他神经退行性疾病的特定目标，其中神经炎症是关键因素。