CD140a+ human oligodendrocyte progenitor cells. Homo sapiens

Glial progenitor cells (GPCs) pervade the human brain. These cells express gangliosides recognized by MAb A2B5, and some but not all can generate oligodendrocytes. Since some A2B5+ GPCs express PDGFa receptor (PDGFRa), which is critical to oligodendrocyte development, we asked if PDGFRa-directed sorting might isolate oligodendrocyte-competent progenitors. We used FACS to sort PDGFRa+ cells from the second trimester fetal human forebrain, based on expression of the PDGFRa epitope CD140a. CD140a+ cells could be maintained as mitotic progenitors that could be instructed to either oligodendrocyte or astrocyte phenotype. Transplanted CD140a+ cells robustly myelinated the hypomyelinated shiverer mouse brain. Microarray confirmed that CD140a+ cells differentially expressed PDGFRA, NG2, OLIG1/2, NKX2.2 and SOX2. Some expressed CD9, thereby defining a CD140a+/CD9+ fraction of oligodendrocyte-biased progenitors. CD140a+ cells differentially expressed genes of the PTN-PTPRZ1, wnt, notch and BMP pathways, suggesting the interaction of self-renewal and fate-restricting pathways in these cells, while identifying targets for their mobilization and instruction. Overall design: 10 samples, 5 CD140a+, and 5 CD140a- sorted samples for individual fetal human brain

神经胶质祖细胞（Glial progenitor cells, GPCs）广泛分布于人类大脑。这类细胞表达可被单克隆抗体（MAb）A2B5识别的神经节苷脂，其中部分（而非全部）可分化产生少突胶质细胞。鉴于部分A2B5阳性的GPCs表达对少突胶质细胞发育至关重要的血小板源性生长因子α受体（PDGFRa），本研究探讨了以PDGFRa为靶点的细胞分选策略是否可分离出具备少突胶质细胞分化潜能的祖细胞。
我们采用荧光激活细胞分选术（Fluorescence-Activated Cell Sorting, FACS），基于血小板源性生长因子α受体表位CD140a的表达水平，从人类妊娠中期胎儿前脑中分选得到PDGFRa阳性细胞。CD140a阳性细胞可作为增殖性祖细胞进行体外培养，并可被诱导定向分化为少突胶质细胞或星形胶质细胞表型。将分选获得的CD140a阳性细胞移植后，可显著促进髓鞘发育缺陷的震颤小鼠（shiverer小鼠）大脑的髓鞘形成。
基因芯片分析证实，CD140a阳性细胞差异表达PDGFRA、NG2、OLIG1/2、NKX2.2及SOX2等基因。其中部分细胞表达CD9，由此可定义出一类偏向少突胶质细胞分化的CD140a+/CD9+祖细胞亚群。CD140a阳性细胞还差异表达PTN-PTPRZ1、Wnt、Notch及骨形态发生蛋白（Bone Morphogenetic Protein, BMP）信号通路相关基因，提示这类细胞的自我更新与命运限定通路间存在相互调控作用，同时为其体外动员与定向诱导分化找到了潜在靶点。
实验设计概述：共包含10份分选样本，其中5份为CD140a阳性分选样本，5份为CD140a阴性分选样本，均来自单个人类胎儿脑组织。