Hematopoietic stem cell heterogeneity and niche cell associations governing definitive hematopoiesis formation

本项目的主要目标是通过阐明可能起作用的各种细胞内在和细胞外在因素（BM生态位）来了解造血干细胞（hsc）在个体发育过程中是如何被调节的。到目前为止，我们从主要造血器官中采集的新生儿P2 HSC的scRNA-seq数据显示，三个HSC组（HSCin1、HSCin2和HSCout）在表型和功能（体外分化潜力和体内重构能力）上存在异质性。对每个群体的氧化石墨烯分析显示，在这一时期，它们具有不同的生物特征，并强化了它们的特定作用。我们的基因列表与斑马鱼造血形成过程中的HSC RNA-seq数据进行了比较，并选择了两个物种中可能决定“HSC成熟”的显着上调的几个基因进行进一步的过表达和下调研究。这项工作目前正在进行中。我们正在通过qPCR分析、体外CFU和体内移植研究同时验证我们的scRNA-seq数据。此外，我们目前正在设计其他在体内追踪这些造血干细胞（条形码）的策略，以直接研究它们对成人造血的贡献。

The primary goal of this project is to understand how hematopoietic stem cells (HSCs) are regulated during ontogeny by elucidating the various cell-intrinsic and cell-extrinsic factors (the BM niche) that may play a role. So far, our scRNA-seq data of neonatal P2 HSCs sampled from major hematopoietic organs has revealed three HSC groups (HSCin1, HSCin2 and HSCout) that are phenotypically and functionally (in vitro differentiation potential and in vivo reconstitution capacity) heterogenous. GO analysis of each group shows enrichment of distinct biological signatures and reinforces their specific role(s) during this temporal period. Our gene list was compared with zebrafish HSC RNA-seq data during definitive hematopoiesis formation and several genes that were significantly upregulated in both species that could potentially dictate “HSC maturation” were selected for further overexpression and downregulation studies. This is currently ongoing. We are simultaneously validating our scRNA-seq data with qPCR analysis, in vitro CFU and in vivo transplantation studies. Furthermore, we are currently devising other strategies for tracing these HSCs (barcoding) in vivo to directly investigate their contribution towards adult hematopoiesis.