Chen Xiaoli, Zhao Qianhao, Li Chen, Geng Yang, Huang Ke, Zhang Jian, Wang Xiaoshan, Yang Jiaqi, Wang Tongjie, Xia Chengxiang, Liu Xiaofei, Meng Minghui, Yang Dan, Zheng Yi, Du Juan, Zhang Xiangzhong, Chen Jiekai, Pan Guangjin, Wang Jinyong
Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China; Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou, China.
Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.
Stem Cell Res. 2015 Sep;15(2):395-402. doi: 10.1016/j.scr.2015.08.009. Epub 2015 Aug 21.
Generating engraftable hematopoietic stem cells (HSCs) from pluripotent stem cells (PSCs) is an ideal approach for obtaining induced HSCs for cell therapy. However, the path from PSCs to robustly induced HSCs (iHSCs) in vitro remains elusive. We hypothesize that the modification of hematopoietic niche cells by transcription factors facilitates the derivation of induced HSCs from PSCs. The Lhx2 transcription factor is expressed in fetal liver stromal cells but not in fetal blood cells. Knocking out Lhx2 leads to a fetal hematopoietic defect in a cell non-autonomous role. In this study, we demonstrate that the ectopic expression of Lhx2 in OP9 cells (OP9-Lhx2) accelerates the hematopoietic differentiation of PSCs. OP9-Lhx2 significantly increased the yields of hematopoietic progenitor cells via co-culture with PSCs in vitro. Interestingly, the co-injection of OP9-Lhx2 and PSCs into immune deficient mice also increased the proportion of hematopoietic progenitors via the formation of teratomas. The transplantation of phenotypic HSCs from OP9-Lhx2 teratomas but not from the OP9 control supported a transient repopulating capability. The upregulation of Apln gene by Lhx2 is correlated to the hematopoietic commitment property of OP9-Lhx2. Furthermore, the enforced expression of Apln in OP9 cells significantly increased the hematopoietic differentiation of PSCs. These results indicate that OP9-Lhx2 is a good cell line for regeneration of hematopoietic progenitors both in vitro and in vivo.
从多能干细胞（PSC）生成可移植的造血干细胞（HSC）是获得用于细胞治疗的诱导性HSC的理想方法。然而，在体外从PSC到强大的诱导性HSC（iHSC）的途径仍然不清楚。我们假设通过转录因子对造血微环境细胞进行修饰有助于从PSC衍生出诱导性HSC。Lhx2转录因子在胎儿肝脏基质细胞中表达，但在胎儿血细胞中不表达。敲除Lhx2会导致细胞非自主作用的胎儿造血缺陷。在本研究中，我们证明Lhx2在OP9细胞（OP9-Lhx2）中的异位表达加速了PSC的造血分化。OP9-Lhx2通过与PSC体外共培养显著提高了造血祖细胞的产量。有趣的是，将OP9-Lhx2和PSC共同注射到免疫缺陷小鼠中也通过畸胎瘤的形成增加了造血祖细胞的比例。来自OP9-Lhx2畸胎瘤而非OP9对照的表型HSC的移植支持短暂的再增殖能力。Lhx2对Apln基因的上调与OP9-Lhx2的造血定向特性相关。此外，在OP9细胞中强制表达Apln显著增加了PSC的造血分化。这些结果表明，OP9-Lhx2无论是在体外还是体内都是用于造血祖细胞再生的良好细胞系。
