Assessing the mechanisms directing cell fate in the dorsal spinal cord

评估背侧脊髓细胞命运的机制

基本信息

批准号：
10615870
负责人：
SAMANTHA J BUTLER
金额：
$ 45.09万
依托单位：
UNIVERSITY OF CALIFORNIA LOS ANGELES
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：
2022-05-01 至 2027-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10615870
关键词：
Address Adopted Aftercare BMP4 Bone Morphogenetic Proteins Cell model Cells ChIP-seq Chicken Model Chickens Complex Data Development Developmental Biology Disease Dorsal Drug Modulation Drug Screening ES Cell Line Environment Family Family member Gene Expression Profiling Genetic Transcription Germ Cells Growth Factor In Vitro Individual Injury Interneurons Ligands Light Logic Mediating Medical Modality Modeling Mus Nature Nociception Outcome Pain Paralysed Pathway interactions Patients Pattern Peripheral Pluripotent Stem Cells Population Process Production Proliferating Proprioception Protein Family Protocols documentation Pruritus Reaction Research Resolution Role SHH gene Second Messenger Systems Sensory Series Signal Pathway Signal Transduction Signaling Protein Specific qualifier value Spinal Spinal Cord Spinal cord damage Subgroup System Touch sensation Translating Tretinoin Vertebral column WNT Signaling Pathway Well in self bone morphogenetic protein receptor type I cell type design differentiation protocol drug testing embryonic stem cell in vivo knock-down member morphogens motor control mouse model nerve stem cell neural progenitor receptor repaired response small molecule inhibitor somatosensory stem cell differentiation stem cell model transcription factor transcriptome transcriptomics

项目摘要

Project Summary The somatosensory system permits us to perceive and react to the environment through modalities that include touch, nociception, thermosensation and proprioception. Somatosensory information is received peripherally and then relayed centrally by different populations of dorsal interneurons (dIs; dI1-dI6) in the spinal cord. Our research objectives are to understand the mechanisms that establish dIs during development and then apply these principles towards designing differentiation protocols to direct the formation of specific populations of dIs from pluripotent stem cells. These cells have the potential to repair damaged sensory circuits and act as substrates for drug screening platforms. We have focused on dissecting the role of the bone morphogenetic protein (BMP) family in dI fate specification. BMPs were widely assumed to act as morphogens, patterning the dorsal spinal cord in a concentration-dependent mechanism similar to the manner in which sonic hedgehog (Shh) patterns the ventral spinal cord. However, our recent studies using mouse, chicken, and mouse embryonic stem cell (mESC) models have found that no evidence that BMPs act as morphogens. Rather, BMPs have signal-specific activities, with differential abilities to direct dorsal progenitor (dP) patterning and/or differentiation through specific type I BMP receptors. Our recent in vivo and in vitro studies have also suggested that dI fates are established in a series of nested choice points. In our model, spinal progenitors are dorsalized by retinoic acid (RA), subdivided into multipotential dP subgroups by BMP signaling, and then resolve into specific dI fates. Since little is known about this patterning process, we will assess in Aim 1 how multipotential dP fates are first established by RA and BMP signaling and identify the mechanisms directing multipotential dPs into specific dI identities. In Aim 2, we will determine the nature of the intracellular response that permits specific BMPs to drive dPs towards different dI identities, addressing two unresolved questions: [1] are canonical receptor regulated (R)-Smads activated in a BMP-specific manner to result in distinct patterning activities? And [2] what factors do the R-Smads in turn regulate to promote dI fates? Together, these studies will investigate a long-standing problem in developmental biology, i.e., understanding how specific outcomes arise from a common signal, and shed light on the specification of dIs, cell types needed to permit paralyzed patients to again interpret their sensory environment. Our specific aims are as follows: Aim 1: Identify the mechanism(s) that establish multipotential dPs and assign them into individual dI fates. Hypothesis: RA±BMP4 direct the formation of multipotential dP subgroups, which resolve into specific dI fates by the asymmetric activation of additional endogenous signaling pathways, such as the Wnt pathway. Aim 2: Assess the role of the Smad and Id families in BMP-induced dI fate specification. Hypothesis: BMPs differentially activate Smad1 and/or Smad5, to regulate the activity of Id family members.

项目摘要体感系统使我们能够通过方式来感知和对环境做出反应包括触摸，伤害感受，热效和本体感受。收到体感信息外围，然后由不同的背膜中间神经元（DIS; di1-di6）集中接力绳索。我们的研究目标是了解在开发过程中建立DIS的机制然后将这些原则应用于设计分化协议以指导特定的形成来自多能干细胞的DIS种群。这些细胞有可能修复受损的感觉电路并充当药物筛查平台的底物。我们专注于剖析骨骼的作用 DI脂肪规格中的形态发生蛋白（BMP）家族。 BMP被广泛假定为形态剂，以浓度依赖性机制对背脊髓进行构图，类似于声音的方式刺猬（SHH）图案腹侧脊髓。但是，我们最近使用鼠标，鸡肉和小鼠胚胎干细胞（MESC）模型发现，没有证据表明BMP是形态剂。相反，BMP具有特定信号的活动，具有指导背祖先（DP）图案的差异能力和/或通过特定I型BMP受体的分化。我们最近的体内和体外研究也建议在一系列嵌套选择点中建立了DI命运。在我们的模型中，脊柱祖细胞是由视黄酸（RA）背盐，通过BMP信号细分为多能DP亚组，然后解决特定的DII命运。由于对此模式过程知之甚少，我们将在AIM 1中评估如何多能力DP命运首先是由RA和BMP信号建立的，并确定指导的机制多能力DPS成特定的DI身份。在AIM 2中，我们将确定细胞内反应的性质这允许特定的BMP将DPS驱动到不同的DI身份，解决了两个未解决的问题：[1] 是按照BMP特异性激活的规范接收器调节（R）-SMADS导致不同的模式活动？ [2] R-Smads反过来促进DI命运的哪些因素？在一起，这些研究将研究发育生物学的长期存在的问题，即了解特定结果由公共信号产生，并阐明了DIS的规格，允许瘫痪所需的细胞类型患者再次解释他们的感觉环境。我们的具体目的如下： AIM 1：确定建立多潜在DP的机制并将其分配到单个DI命运中。假设：RA±BMP4指导多能DP亚组的形成，该子组分解为特定的DI命运通过其他内源信号通路（例如Wnt途径）的不对称激活。 AIM 2：评估SMAD和ID家族在BMP诱导的DI命运规范中的作用。假设：BMP不同激活SMAD1和/或SMAD5，以调节ID家族成员的活性。