Excellence in Research: The role of Neuregulin-1 in proliferation and differentiation of brain cortical neuronal stem cells during fetal development

神经调节蛋白（NRGs）是一个结构相关的信号蛋白家族，与ErbB家族的受体酪氨酸激酶结合，介导无数的细胞功能，包括神经元和非神经系统的存活、增殖和分化。神经调节蛋白1 （Neuregulin-1, NRG-1）及其受体ErB4介导的信号传导在大脑发育和功能中起着至关重要的作用。该项目将利用细胞培养中生长的神经元团（称为“皮质类器官”）以及小鼠实验来研究神经调节蛋白-1及其受体ErbB4在大脑发育中的作用。由于NGR1基因的缺失在胚胎小鼠中是致命的，皮质类器官被用作替代品来阐明其在大脑发育中的作用。在小鼠中进行平行比较将能够验证观察到的效果，并提供一个新的平台，可以进行以前不可能的操作和假设检验。此外，了解NRG1对皮质神经元细胞增殖和分化的影响将揭示介导脑形态发生的关键机制。该研究将通过生成Neuregulin-1/ErbB4表达和细胞定位的发育图谱来推进该领域的发展。该项目为指导代表性不足的高中，少数民族本科生和研究生以及博士后提供了一个独特的机会，让他们参与莫尔豪斯医学院最前沿的3D类器官组织工程研究，这将使他们能够追求STEM职业，最终目标是增强美国科学劳动力的多样性。神经调节蛋白（NRGs）介导与神经系统、乳腺、心脏和其他器官的发育和维持相关的各种功能。NRG-1调控神经元和非神经元细胞类型的细胞维持、分化、增殖、迁移和凋亡，因此备受关注。虽然NRG-1在胎儿发育中的作用已被报道，但其在大脑发育过程中的信号机制中的作用尚不清楚。在大脑皮层发育过程中，NRG-1/ErbB4信号的作用及其与神经干细胞（NSC）增殖和分化、神经迁移和细胞成熟相关的因子（生物标志物）的相互作用尚不清楚。该项目研究了NRG-1如何通过erbb4依赖通路介导正常脑皮质发育，该通路涉及细胞周期、神经迁移、分化和细胞成熟的调节因子（效应因子）。将NRG-1及其受体ErbB4在人皮质类器官（单独或与小胶质细胞共培养）中的区域特异性表达和功能与NRG-1缺陷小鼠的皮质进行比较，以阐明NRG-1在脑发育中的作用。包括数字空间分析（DSP）、单细胞分泌蛋白信号（IsoPlexis）、生物成像（共聚焦、光片和双光子显微镜）、免疫组织化学（IHC）、Western blotting和单细胞RNA测序（scRNA seq）在内的多种技术将用于比较NRG-1在人和小鼠皮质类器官发育中的细胞表达和功能。在大脑皮层发育过程中，NRG1/ErbB4信号与发育因子之间的串扰将被评估。该项目将阐明NRG-1/ErbB4信号在功能性大脑发育中的作用。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Neuregulins (NRGs) are a family of structurally related signaling proteins that bind to receptor tyrosine kinases of the ErbB family and mediate a myriad of cellular functions including survival, proliferation, and differentiation in both neuronal and non-neural systems. Signaling mediated by Neuregulin-1 (NRG-1) and its receptor ErB4 plays a critical role in brain development and functions. This project will use conglomerations of neurons grown in cell culture (called “cortical organoids”), as well as experiments in mice, to investigate the role of Neuregulin-1 and its receptor ErbB4 in brain development. Because deletion of the NGR1 gene is lethal in embryonic mice, cortical organoids are used as a substitute to elucidate its role in brain development. Parallel comparisons in mice will enable validation of observed effects and provide a new platform amenable to manipulation and hypothesis testing that was not previously possible. Furthermore, understanding the effects of NRG1 on cell proliferation and differentiation in cortical neurons will unveil key mechanisms mediating brain morphogenesis. The proposed study will advance the field by generating a developmental map of Neuregulin-1/ErbB4 expression and cellular localization. The project provides a unique opportunity for mentoring underrepresented high school, minority undergraduate and graduate students as well as postdoctoral fellows to participate in cutting edge 3D organoid tissue engineering research at Morehouse School of Medicine, that will position them to pursue STEM careers with the ultimate goal of enhancing the diversity of the scientific workforce in the USA.Neuregulins (NRGs) mediate various functions associated with the development and maintenance of the nervous system, breast, heart, and other organs. NRG-1 is of great interest because it regulates cell maintenance, differentiation, proliferation, migration, and apoptosis in neuronal and non-neuronal cell types. While the role of NRG-1 in fetal development has been reported, its role in signaling mechanisms during brain development is not well understood. The role of NRG-1/ErbB4 signaling, as well as its crosstalk with factors (biomarkers) associated with neural stem cell (NSC) proliferation and differentiation, neural migration and cellular maturation during brain cortex development remains unknown. This project examines how NRG-1 mediates normal brain cortical development via an ErbB4-dependent pathway involving moderators (effectors) of cell cycle, neural migration, differentiation, and cellular maturation. Region-specific expression and function of NRG-1 and its receptor ErbB4 in human cortical organoids (either alone or in co-culture with microglial cells) will be compared with cortices of NRG-1 deficient mice to elucidate the role of NRG-1 in brain development. Multiple techniques including Digital Space Profiling (DSP), signals of proteins secreted from single cells (IsoPlexis), biological imaging (confocal, light sheet and 2-photon microscopy), immunohistochemistry (IHC), Western blotting and single cell RNA sequencing (scRNA seq) will be used to compare cellular expression and function of NRG-1 in human and murine cortical organoid development. Crosstalk between NRG1/ErbB4 signaling and developmental factors during cortical brain development will be assessed. This project will clarify the role of NRG-1/ErbB4 signaling in the development of a functional brain.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.