真核细胞质膜包含几种不对称分布的磷脂，由P4-ATPase flippase复合物维持。在这里，我们展示了不对称损失对造血干细胞（HSCs）的生物学影响和机制。使用Atp8a1敲除小鼠模型，分析了HSC（长期HSC和短期HSC）种群以评估其丰度和功能。此外，进行了竞争性骨髓移植和5-FU应激试验。在造血干细胞和祖细胞上进行RNA测序，使用免疫荧光染色和彗星电泳测定DNA损伤。使用西方印迹法确认了关键信号通路成员的蛋白质丰度。Atp8a1敲除导致轻微高白细胞病，与造血干细胞和BCR / ABL1转化白血病干细胞（LSC）高增殖有关。 Atp8a1敲除增加了HSC在重建试验中具有的竞争优势的再造能力。没有Atp8a1的HSC对5-FU诱导的凋亡更为敏感。此外，Atp8a1删除防止了HSC的DNA损伤，并促进了DNA修复过程。涉及PI3K-AKT-mTORC1、DNA修复和AP-1复合物信号通路的基因在Atp8a1删除的HSC中富集并上调。此外，Atp8a1的删除导致PTEN蛋白水平下降，从而激活PI3K-AKT-mTORC1信号通路，进一步增加了JNK / AP-1信号通路和YAP1磷酸化的活性。我们确定了Atp8a1在造血和HSCs中的作用。Atp8a1的删除导致磷脂酰丝氨酸不对称和细胞内信号传导的混沌丢失。©2023。 Springer Nature Switzerland AG。

The eukaryotic cell plasma membrane contains several asymmetrically distributed phospholipids, which is maintained by the P4-ATPase flippase complex. Herein, we demonstrated the biological effects and mechanisms of asymmetrical loss in hematopoietic stem cells (HSCs).An Atp8a1 knockout mouse model was employed, from which the HSC (long-term HSCs and short-term HSCs) population was analyzed to assess their abundance and function. Additionally, competitive bone marrow transplantation and 5-FU stress assays were performed. RNA sequencing was performed on Hematopoietic Stem and Progenitor Cells, and DNA damage was assayed using immunofluorescence staining and comet electrophoresis. The protein abundance for members of key signaling pathways was confirmed using western blotting.Atp8a1 deletion resulted in slight hyperleukocytosis, associated with the high proliferation of HSCs and BCR/ABL1 transformed leukemia stem cells (LSCs). Atp8a1 deletion increased the repopulation capability of HSCs with a competitive advantage in reconstitution assay. HSCs without Atp8a1 were more sensitive to 5-FU-induced apoptosis. Moreover, Atp8a1 deletion prevented HSC DNA damage and facilitated DNA repair processes. Genes involved in PI3K-AKT-mTORC1, DNA repair, and AP-1 complex signaling were enriched and elevated in HSCs with Atp8a1 deletion. Furthermore, Atp8a1 deletion caused decreased PTEN protein levels, resulting in the activation of PI3K-AKT-mTORC1 signaling, further increasing the activity of JNK/AP-1 signaling and YAP1 phosphorylation.We identified the role of Atp8a1 on hematopoiesis and HSCs. Atp8a1 deletion resulted in the loss of phosphatidylserine asymmetry and intracellular signal transduction chaos.© 2023. Springer Nature Switzerland AG.