Project description:From mice, strand-specific RNA-Seq of granulocyte-myeloid progenitors (GMP) and hematopoietic stem cells (HSC). Cancer stem cells (CSC) were created with MLL-ENL transfections using puromycin for both GMP and HSCs. Further knock-outs were created of -catenin (Ctnnb1) and Hoxa9.
Project description:The transcription factor Runx1 is essential for the establishment of definitive hematopoiesis during embryonic development. In adult blood homeostasis, Runx1 plays a pivotal role in the maturation of lymphocytes and megakaryocytes. Furthermore, Runx1 is required for the regulation of hematopoietic stem and progenitor cell (HSPC) pools. However, how Runx1 orchestrates self-renewal and lineage choices in combination with other factors is not well understood. Here we describe a genome-scale RNAi screen to detect genes that cooperate with Runx1 in regulating HSPCs. We identify the polycomb group protein Pcgf1 as an epigenetic regulator involved in hematopoietic cell differentiation. We show that simultaneous depletion of Runx1 and Pcgf1 allows sustained self-renewal while blocking differentiation of HSPCs in vitro. We find an upregulation of HoxA cluster genes upon Pcgf1 knockdown that possibly accounts for the increase in self-renewal. Further, our data suggest that cells lacking both Runx1 and Pcgf1 are blocked at an early progenitor stage, indicating that a concerted action of the transcription factor Runx1 together with the epigenetic repressor Pcgf1 is necessary for terminal differentiation. Thus, our work discovers a genetic link between transcriptional and epigenetic regulation that is required for hematopoietic differentiation. Hematopoietic stem and precursor cells freshly isolated from mice were transduced with an shRNA targeting Pcgf1 or a control shRNA. Cells were selected with puromycin for 36 h before total mRNA was isolated.
Project description:Hematopoietic stem cells are both necessary and sufficient to sustain the complete blood system of vertebrates. Here we show that Nfix, a member of the nuclear factor I (Nfi) family of transcription factors, is highly expressed by hematopoietic stem and progenitor cells (HSPC) of murine adult bone marrow. Although shRNA mediated knockdown of Nfix expression in Lineage-Sca-1+c-Kit+ HSPC had no effect on in vitro cell growth or viability, Nfix-depleted HSPC displayed a significant loss of colony forming potential, as well as short- and long-term in vivo hematopoietic repopulating activity. Analysis of recipient mice 4-20 days post-transplant revealed that Nfix-depleted HSPC establish in the bone marrow but fail to persist due to increased apoptotic cell death. Gene expression profiling of Nfix-depleted HSPC reveals that loss of Nfix expression in HSPC is concomitant with a decrease in the expression of multiple genes known to be important for HSPC survival, such as Erg, Mecom, Mpl and Prdm16. These data reveal that Nfix is a novel regulator of HSPC survival post-transplantation and establish, for the first time, a role for Nfi genes in the regulation of this cellular compartment. 3 NFIX depleted samples are compared to 3 wt samples
Project description:Human cSki was overexpressed using MIGR1 retrovirus in sorted murine Lin-c-Kit+Sca-1+ cells. Cells were infected and cultured for 2 days after infection prior to isolation of GFP+ve cells and microarray. GFP+ve MIGR1 and cSKI cells were compared. Each sample represents an independent infection with either cSki or MIGR1 Comparison of GFP+ve LKS+ infected with MIGR1 and cSki
Project description:Exosc8 and Exosc9 are components of the exosome that establish a barricade to erythroid maturation. Here, we knocked down Exosc8 in fetal liver-derived erythroid progenitor cells to determine the cohort of Exosc8-regulated genes in erythroid cells. Freshly isolated fetal liver progenitor cells were infected with retrovirus expressing shRNA targeting either luciferase or Exosc8. Total RNA was isolated from these cells after 3 days ex-vivo culture, during which the cells underwent erythroid maturation.
Project description:The debilitating autoimmune disease Systemic Lupus Erythematosus (SLE) is closely associated with Toll-like receptor (TLR) 7 and type I interferon (IFN) activity in humans and in murine SLE-like disease. Two central manifestations of SLE affect the myeloid lineage of the immune system, myeloid expansion and anemia. Yet, whether these symptoms are linked and the role of TLR7 and/or type I IFN in these processes is unclear. Here we show that TLR7 signaling promotes cell-autonomous, phosphoinositide 3-kinase (PI3K)- and mammalian target of rapamycin (mTOR)-dependent macrophage development from the common myeloid progenitor (CMP). Strikingly, this TLR7-driven macrophage development requires and is enhanced by type I IFN. Genome-wide transcriptional profiling and functional studies demonstrated that TLR7 promoted the expression of Spic, the master regulator of splenic red pulp macrophages (RPM) and preferential development of hemophagocytic RPM-like cells from CMP in vitro. We found increased incidence of RPM-like cells in vivo in a mouse model of SLE caused by TLR7 overexpression, which correlated with decreased red blood cell (RBC) count and anemia. These findings demonstrate a mechanism by which TLR7 signaling promotes anemia that is of clinical significance in SLE, other rheumatological diseases and chronic viral infections. This work also identifies a previously unknown molecular pathway by which TLR signaling and type I IFN synergize to promote myeloid development from hematopoietic progenitors. CMP were sorted from the bone marrow of wild-type C57BL/6 mice, cultured with SCF+R848 or SCFr+MCSF, and CD11b+F4/80+ macrophages sorted after 5 days, n=3 per group
Project description:We designed microRNA-responsive, modified mRNA switches (miR-switches) that quantitatively control their own translation level by determining the miRNA activities. We found that the three miR-switches (i.e., miR-1-, miR-208-, and miR-499-switches) enable to purify cardiomyocytes differentiated from hPSCs with high efficiency, accuracy, and safety. The purified cardiomyocytes were engrafted in mouse heart and did not form tumor. Simultaneous purification of two different cell types, cardiomyocytes and endothelial cells, was also performed by transfecting the mRNA responding to the both miR-208 and miR-126, into heterogeneous cell population derived from hPSCs. In addition, selective induction of apoptosis in noncardiomyocytes triggered by miR-1/208-Bim switch enriched cardiomyocytes without cell sorting. The mRNA switch could purify desired cell types and control cell death pathways by monitoring the miRNA expression dynamics during cell fate conversion. MYH6-EIP4 day8 differentiated cells (EGFP+) for miRNA, N=1 MYH6-EIP4 day8 differentiated cells (EGFP-) for miRNA, N=1 MYH6-EIP4 day20 differentiated cells (EGFP+) for miRNA, N=1 MYH6-EIP4 day20 differentiated cells (EGFP-) for miRNA, N=1 HUVEC for miRNA, N=2 AoSMC for miRNA, N=2 Hepatocytes for miRNA, N=2 NHDF for miRNA, N=2
Project description:We designed microRNA-responsive, modified mRNA switches (miR-switches) that quantitatively control their own translation level by determining the miRNA activities. We found that the three miR-switches (i.e., miR-1-, miR-208-, and miR-499-switches) enable to purify cardiomyocytes differentiated from hPSCs with high efficiency, accuracy, and safety. The purified cardiomyocytes were engrafted in mouse heart and did not form tumor. Simultaneous purification of two different cell types, cardiomyocytes and endothelial cells, was also performed by transfecting the mRNA responding to the both miR-208 and miR-126, into heterogeneous cell population derived from hPSCs. In addition, selective induction of apoptosis in noncardiomyocytes triggered by miR-1/208-Bim switch enriched cardiomyocytes without cell sorting. The mRNA switch could purify desired cell types and control cell death pathways by monitoring the miRNA expression dynamics during cell fate conversion. MYH6-EIP4 iPSCs for mRNA, N=3 MYH6-EIP4 day18 cardiomyocytes (before transfection) for mRNA, N=3 MYH6-EIP4 day19 cardiomyocytes (miR-1-switch day1) for mRNA, N=3 MYH6-EIP4 day19 cardiomyocytes (without transfection) for mRNA, N=3 MYH6-EIP4 day25 cardiomyocytes (miR-1-switch day7) for mRNA, N=3 MYH6-EIP4 day25 cardiomyocytes (without transfection) for mRNA, N=3 201B7 d22 miR-208a-BFP sorted cells for mRNA, N=1 201B7 d22 miR-208a-BFP negative fraction sorted cells for mRNA, N=1 201B7 d22 SIRPA+LIN- sorted cells for mRNA, N=1 201B7 d22 SIRPA+LIN- negative fraction sorted cells for mRNA, N=1 201B7 d22 VCAM1+ sorted cells for mRNA, N=1 201B7 d22 VCAM1+negative fraction sorted cells for mRNA, N=1 MYH6-EIP4 day19 cardiomyocytes (miR-208a-Bim-switch day1) for mRNA, N=1 MYH6-EIP4 day19 cardiomyocytes (without transfection) for mRNA, N=1 MYH6-EIP4 day21 cardiomyocytes (miR-208a-Bim-switch day7) for mRNA, N=1 MYH6-EIP4 day21 cardiomyocytes (without transfection) for mRNA, N=1 MYH6-EIP4 day25 cardiomyocytes (miR-208a-Bim-switch day7) for mRNA, N=1 MYH6-EIP4 day25 cardiomyocytes (without transfection) for mRNA, N=1
Project description:Isolation of specific cell types, including pluripotent stem cell (PSC)-derived populations, is frequently accomplished using cell surface antigens expressed by the cells of interest. However, specific antigens for many cell types have not been identified, making their isolation difficult. Here, we describe an efficient method for purifying cells based on endogenous miRNA activity. We designed synthetic mRNAs encoding a fluorescent protein tagged with sequences targeted by miRNAs expressed by the cells of interest. These miRNA switches control their own translation levels by sensing miRNA activities. Several miRNA switches (miR-1-, miR-208a-, and miR-499a-5p-switches) efficiently purified cardiomyocytes differentiated from human PSCs, and switches encoding the apoptosis inducer Bim enriched for cardiomyocytes without cell sorting. This approach is generally applicable, as miR-126-, miR-122-5p- and miR-375-switches purified endothelial cells, hepatocytes and INSULIN-producing cells differentiated from hPSCs, respectively. Thus, miRNA switches can purify cell populations for which other isolation strategies are unavailable. MYH6-EIP4 day8 differentiated cells (EGFP+) for miRNA, N=1 MYH6-EIP4 day8 differentiated cells (EGFP-) for miRNA, N=1 MYH6-EIP4 day20 differentiated cells (EGFP+) for miRNA, N=1 MYH6-EIP4 day20 differentiated cells (EGFP-) for miRNA, N=1 HUVEC for miRNA, N=2 AoSMC for miRNA, N=2 Hepatocytes for miRNA, N=2 NHDF for miRNA, N=2 MYH6-EIP4 iPSCs for mRNA, N=3 MYH6-EIP4 day18 cardiomyocytes (before transfection) for mRNA, N=3 MYH6-EIP4 day19 cardiomyocytes (miR-1-switch day1) for mRNA, N=3 MYH6-EIP4 day19 cardiomyocytes (without transfection) for mRNA, N=3 MYH6-EIP4 day25 cardiomyocytes (miR-1-switch day7) for mRNA, N=3 MYH6-EIP4 day25 cardiomyocytes (without transfection) for mRNA, N=3 201B7 d22 miR-208a-BFP sorted cells for mRNA, N=1 201B7 d22 miR-208a-BFP negative fraction sorted cells for mRNA, N=1 201B7 d22 SIRPA+LIN- sorted cells for mRNA, N=1 201B7 d22 SIRPA+LIN- negative fraction sorted cells for mRNA, N=1 201B7 d22 VCAM1+ sorted cells for mRNA, N=1 201B7 d22 VCAM1+negative fraction sorted cells for mRNA, N=1 MYH6-EIP4 day19 cardiomyocytes (miR-208a-Bim-switch day1) for mRNA, N=1 MYH6-EIP4 day19 cardiomyocytes (without transfection) for mRNA, N=1 MYH6-EIP4 day21 cardiomyocytes (miR-208a-Bim-switch day7) for mRNA, N=1 MYH6-EIP4 day21 cardiomyocytes (without transfection) for mRNA, N=1 MYH6-EIP4 day25 cardiomyocytes (miR-208a-Bim-switch day7) for mRNA, N=1 MYH6-EIP4 day25 cardiomyocytes (without transfection) for mRNA, N=1