Gene-expression changes resulting from loss of the mTORC1 component Raptor in murine hematopoietic stem and progenitor cell-enriched populations (HSPC)

We investigated the role of mTORC1 in murine hematopoiesis by conditionally deleting the Raptor gene in murine hematopoietic stem cells. We observed mutliple alterations evoked by Raptor loss in hematopoiesis and profiled gene-expression alterations induced by raptor loss in Flt3-Lin-Sca1+cKit+ hematopoietic stem and progenitor enriched cell populations, 5 weeks post Raptor deletion. Flt3-Lin-Sca1+cKit+ cells were flow sorted from mice containing homozygous floxed alleles for exon 6 of the Raptor gene in the presence (MT group) or absence (WT group) of the MxCre transgene, which was induced with injections of mice with pIpC 5 weeks before cell isolation.

本研究通过在小鼠造血干细胞中条件性敲除Raptor基因（Raptor），探究了哺乳动物雷帕霉素靶蛋白复合物1（mTORC1）在小鼠造血过程中的功能。我们观察到Raptor缺失可在造血过程中引发多种异常，并在Raptor缺失5周后，针对Flt3⁻Lin⁻Sca1⁺cKit⁺富集造血干细胞和祖细胞的细胞群，对该细胞群中由Raptor缺失诱导的基因表达异常开展了谱分析。实验所用的Flt3⁻Lin⁻Sca1⁺cKit⁺细胞通过流式分选获取：供体小鼠均携带Raptor基因外显子6的纯合floxed等位基因，分别带有（MT组）或不带有（WT组）MxCre转基因（MxCre transgene）；MxCre的诱导则通过在细胞分离前5周向小鼠注射聚肌胞苷酸（pIpC）实现。