Objective: To investigate the effect of lysosomal-associated protein transmembrane-4 Beta(Laptm4b) deletion on hematopoietic stem/progenitor cells (HSPCs) homeostasis in mice.
Methods: The hematopoietic system specific Laptm4b-deficient mice were constructed. The number and proportion of HSPCs (LSK, LT, ST, MPP, etc) in Laptm4b-deficient mice were analyzed by flow cytometry. Single SLAM-HSC cell was sorted by flow sorter and cultured in vitro to measure the effect of Laptm4b deletion on the colony forming ability of hematopoietic stem cells (HSCs). The effect of Laptm4b-deficient on the reconstitution ability of HSCs in mice was detected by competitive transplantation experiment of SLAM-HSC cells.
Results: Laptm4b deficiency could moderately upregulate the proportion of T cells in the peripheral blood of the mice, but showed no significant effect on the proportion and number of HSPCs. Laptm4b deletion showed no effect on the reconstruction ability of HSCs after competitive transplantation, but it could inhibit the colony formation of HSCs in vitro.
Conclusion: LAPTM4B may play a role in HSCs under the proliferation stress. Laptm4b-deficient in mice hematopoietic system showed no significant effect on the HSPCs homeostasis maintenance and reconstruction ability.
题目: Laptm4b缺失对小鼠造血干祖细胞稳态维持的影响.
目的: 探讨溶酶体相关4次跨膜蛋白B（LAPTM4B）在小鼠造血干祖细胞稳态维持过程中的作用.
方法: 构建造血系统特异的Laptm4b缺失小鼠；采用流式细胞术分析该模型小鼠的造血干祖细胞：LSK、LT、ST、MPP等细胞的数目和比例；通过流式分选仪分选造血干细胞SLAM-HSC，体外培养检测Laptm4b缺失对造血干细胞克隆形成能力的影响；通过造血干细胞SLAM-HSC竞争性骨髓移植实验分析Laptm4b缺失对小鼠造血干细胞造血重建能力的影响.
结果: Laptm4b基因缺失仅轻微上调稳态下小鼠外周血中的T细胞的比例，对稳态下小鼠造血干祖细胞的比例和数量无显著影响。Laptm4b基因的缺失不影响造血干细胞竞争性移植后的造血重建能力，但能够抑制体外培养下造血干细胞的克隆形成.
结论: Laptm4b缺失可能在造血干细胞体外扩增等快速增殖压力下发挥一定的抑制作用。在造血系统中特异敲除Laptm4b基因对小鼠造血干祖细胞的稳态维持及其造血重建能力无显著影响.