2019 Vol. 10, No. 1

In this issue, Li et al. reported the application of extended pluripotent stem (EPS) cells in generating gene-targeted mouse models, which permits direct and rapid constructing mouse models through tetraploid complementation. In the same issue, Du et al. reported efficient derivation of EPS cells from NOD-scid Il2rg-/- mice, which are refractory to pluripotent cell establishment. Collectively, these two studies show the great potentials of EPS cells in generating mouse models and establishing pluripotent cells with non-permissive backgrounds, which highlight the possibility of using EPS technology to construct mouse models from refractory strains. The cover image shows that the mouse embryo is surrounded by the core four components of EPS culturing medium (LIF, CHIR 99021, DiM and MiH).
“In front of patients, I will always be a pupil.” Dr. Xiaoqian Zhang: the founder of the modern Chinese gastroenterology
Lu Wang, Xudong Liu, Wenli Duan, Shu-yang Zhang
2019, 10(1): 1-4. doi: 10.1007/s13238-018-0561-4
Extended pluripotent stem cells facilitate mouse model generation
Guanghai Xiang, Haoyi Wang
2019, 10(1): 5-7. doi: 10.1007/s13238-018-0573-0
Release and uptake mechanisms of vesicular Ca2+ stores
Junsheng Yang, Zhuangzhuang Zhao, Mingxue Gu, Xinghua Feng, Haoxing Xu
2019, 10(1): 8-19. doi: 10.1007/s13238-018-0523-x
Cells utilize calcium ions (Ca2+) to signal almost all aspects of cellular life, ranging from cell proliferation to cell death, in a spatially and temporally regulated manner. A key aspect of this regulation is the compartmentalization of Ca2+ in various cytoplasmic organelles that act as intracellular Ca2+ stores. Whereas Ca2+ release from the large-volume Ca2+ stores, such as the endoplasmic reticulum (ER) and Golgi apparatus, are preferred for signal transduction, Ca2+ release from the small-volume individual vesicular stores that are dispersed throughout the cell, such as lysosomes, may be more useful in local regulation, such as membrane fusion and individualized vesicular movements. Conceivably, these two types of Ca2+ stores may be established, maintained or refilled via distinct mechanisms. ER stores are refilled through sustained Ca2+ influx at ER-plasma membrane (PM) membrane contact sites (MCSs). In this review, we discuss the release and refilling mechanisms of intracellular small vesicular Ca2+ stores, with a special focus on lysosomes. Recent imaging studies of Ca2+ release and organelle MCSs suggest that Ca2+ exchange may occur between two types of stores, such that the small stores acquire Ca2+ from the large stores via ER-vesicle MCSs. Hence vesicular stores like lysosomes may be viewed as secondary Ca2+ stores in the cell.
Short articles
Rapid generation of gene-targeted EPS-derived mouse models through tetraploid complementation
Haibo Li, Chaoran Zhao, Jun Xu, Yaxing Xu, Chunmei Cheng, Yinan Liu, Ting Wang, Yaqin Du, Liangfu Xie, Jingru Zhao, Yanchuang Han, Xiaobao Wang, Yun Bai, Hongkui Deng
2019, 10(1): 20-30. doi: 10.1007/s13238-018-0556-1
One major strategy to generate genetically modified mouse models is gene targeting in mouse embryonic stem (ES) cells, which is used to produce gene-targeted mice for wide applications in biomedicine. However, a major bottleneck in this approach is that the robustness of germline transmission of gene-targeted ES cells can be significantly reduced by their genetic and epigenetic instability after long-term culturing, which impairs the efficiency and robustness of mouse model generation. Recently, we have established a new type of pluripotent cells termed extended pluripotent stem (EPS) cells, which have superior developmental potency and robust germline competence compared to conventional mouse ES cells. In this study, we demonstrate that mouse EPS cells well maintain developmental potency and genetic stability after long-term passage. Based on gene targeting in mouse EPS cells, we established a new approach to directly and rapidly generate gene-targeted mouse models through tetraploid complementation, which could be accomplished in approximately 2 months. Importantly, using this approach, we successfully constructed mouse models in which the human interleukin 3 (IL3) or interleukin 6 (IL6) gene was knocked into its corresponding locus in the mouse genome. Our study demonstrates the feasibility of using mouse EPS cells to rapidly generate mouse models by gene targeting, which have great application potential in biomedical research.
Efficient derivation of extended pluripotent stem cells from NOD-scid Il2rg-/- mice
Yaqin Du, Ting Wang, Jun Xu, Chaoran Zhao, Haibo Li, Yao Fu, Yaxing Xu, Liangfu Xie, Jingru Zhao, Weifeng Yang, Ming Yin, Jinhua Wen, Hongkui Deng
2019, 10(1): 31-42. doi: 10.1007/s13238-018-0558-z
Recently we have established a new culture condition enabling the derivation of extended pluripotent stem (EPS) cells, which, compared to conventional pluripotent stem cells, possess superior developmental potential and germline competence. However, it remains unclear whether this condition permits derivation of EPS cells from mouse strains that are refractory or non-permissive to pluripotent cell establishment. Here, we show that EPS cells can be robustly generated from non-permissive NOD-scid Il2rg-/- mice through de novo derivation from blastocysts. Furthermore, these cells can also be efficiently generated by chemical reprogramming from embryonic NOD-scid Il2rg-/- fibroblasts. NOD-scid Il2rg-/- EPS cells can be expanded for more than 20 passages with genomic stability and can be genetically modified through gene targeting. Notably, these cells contribute to both embryonic and extraembryonic lineages in vivo. More importantly, they can produce chimeras and integrate into the E13.5 genital ridge. Our study demonstrates the feasibility of generating EPS cells from refractory mouse strains, which could potentially be a general strategy for deriving mouse pluripotent cells. The generation of NOD-scid Il2rg-/- EPS cell lines permits sophisticated genetic modification in NOD-scid Il2rg-/- mice, which may greatly advance the optimization of humanized mouse models for biomedical applications.
Research articles
Neoblast-enriched zinc finger protein FIR1 triggers local proliferation during planarian regeneration
Xiao-Shuai Han, Chen Wang, Fang-hao Guo, Shuang Huang, Yong-Wen Qin, Xian-Xian Zhao, Qing Jing
2019, 10(1): 43-59. doi: 10.1007/s13238-018-0512-0
Regeneration, relying mainly on resident adult stem cells, is widespread. However, the mechanism by which stem cells initiate proliferation during this process in vivo is unclear. Using planarian as a model, we screened 46 transcripts showing potential function in the regulation of local stem cell proliferation following 48 h regeneration. By analyzing the regeneration defects and the mitotic activity of animals under administration of RNA interference (RNAi), we identified factor for initiating regeneration 1 (Fir1) required for local proliferation. Our findings reveal that Fir1, enriched in neoblasts, promotes planarian regeneration in any tissue-missing context. Further, we demonstrate that DIS3 like 3'-5' exoribonuclease 2 (Dis3l2) is required for Fir1 phenotype. Besides, RNAi knockdown of Fir1 causes a decrease of neoblast wound response genes following amputation. These findings suggest that Fir1 recognizes regenerative signals and promotes DIS3L2 proteins to trigger neoblast proliferation following amputation and provide a mechanism critical for stem cell response to injury.
Hepatitis B virus is degraded by autophagosome-lysosome fusion mediated by Rab7 and related components
Yong Lin, Chunchen Wu, Xueyu Wang, Thekla Kemper, Anthony Squire, Matthias Gunzer, Jiming Zhang, Xinwen Chen, Mengji Lu
2019, 10(1): 60-66. doi: 10.1007/s13238-018-0555-2
Neonatal lethality and recycling defect of transferrin receptor in mice with Syntaxin12/13 disruption
Fang Li, Chun-Feng Liu, Yin-Zhen Xu, Yi-Lin Guo, Shu-Wen Xue, Xiang-Dong Kong, Hai-bing Zhang, Yan Zhang, Jian-Sheng Kang
2019, 10(1): 67-71. doi: 10.1007/s13238-018-0519-6
Simultaneous and systematic analysis of cellular and viral gene expression during Enterovirus 71-induced host shutoff
Yongquan Lin, Yan Wang, Hui Li, Yuhang Chen, Wentao Qiao, Zhi Xie, Juan Tan, Zhilong Yang
2019, 10(1): 72-77. doi: 10.1007/s13238-018-0535-6