Project description:Endothelial cell-selective adhesion molecule (ESAM) is a life-long maker for hematopoietic stem cells (HSCs). Although we previously elucidated the functional importance of ESAM on HSCs in stress-induced hematopoiesis in adults, it remained unknown how ESAM affects hematopoietic development during fetal life. To address this issue, we analyzed fetuses of conventional ESAM-knockout mice.
Project description:Endothelial cell-selective adhesion molecule (ESAM) is a life-long maker for hematopoietic stem cells (HSCs). Although we previously elucidated the functional importance of ESAM on HSCs in stress-induced hematopoiesis in adults, it remained unknown how ESAM affects hematopoietic development during fetal life. To address this issue, we analyzed fetuses of conditional ESAM-knockout mice.
Project description:ZFP36L2, zinc finger protein 36, C3H type-like 2 (also known as Brf2, Erf2, Tis11D) is a member of the tristetraprolin (TTP; Zfp36) family of tandem CCCH zinc finger proteins that can bind to AU-rich elements (AREs) in the 3'-untranslated region of mRNAs, leading to their deadenylation and subsequent degradation. We have generated Zfp36l2 knockout mice. Knockout mice were born at the expected Mendelian frequency, but within several weeks of birth they died rather suddenly with pallor and frequent intestinal hemorrhage. These mice exhibited pancytopenia, decreased hematopoietic progenitor cells from fetal liver and yolk sac, and ineffective hematopoietic stem cells. Since ZFP26L2 is likely to function as an ARE-containing mRNA destabilizing protein, we were interested in identifying any abnormally stabilized transcripts in fetal livers from the Zfp36l2 knockout mice whose protein product may directly or indirectly affect hematopoietic stem cell function.
Project description:We describe the proteomic composition of the extracellular environment of fetal and adult hematopoietic progenitors by data-independent acquisition mass spectrometry analysis.
Project description:Advances in pluripotent stem cell and reprogramming technologies have given hope of generating hematopoietic stem cells (HSC) in culture. To succeed, greater understanding of the self-renewing HSC during human development is required. We discovered that glycophosphatidylinositol-anchored surface protein GPI-80 (Vanin 2) defines a distinct subpopulation of human fetal hematopoietic stem/progenitor cells (HSPC) with self-renewal ability. CD34+CD90+CD38-GPI-80+ HSPC were the sole population that maintained proliferative potential and undifferentiated state in bone marrow stroma co-culture, and engrafted in immunodeficient mice. GPI-80 expression also enabled tracking of HSC migration between human fetal hematopoietic niches. The most highly enriched surface protein in GPI-80+ HSPC as compared to their progeny was Integrin alpha-M (ITGAM), which in leukocytes cooperates with GPI-80 to support migration. Knockdown of either GPI-80 or ITGAM was sufficient to perturb undifferentiated HSPC in stroma co-culture. These findings indicate that human fetal HSC utilize common mechanisms with leukocytes for cell-cell interactions governing HSC self-renewal. We used microarrays to identify genes enriched in the GPI-80+ hematopoietic stem and progenitor population in fetal liver. RNA was extracted from enriched fetal liver hematopoietic stem and progenitor cells, and downstream progenitors, for comparison based on Affymetrix arrays.
Project description:Advances in pluripotent stem cell and reprogramming technologies have given hope of generating hematopoietic stem cells (HSC) in culture. To succeed, greater understanding of the self-renewing HSC during human development is required. We discovered that glycophosphatidylinositol-anchored surface protein GPI-80 (Vanin 2) defines a distinct subpopulation of human fetal hematopoietic stem/progenitor cells (HSPC) with self-renewal ability. CD34+CD90+CD38-GPI-80+ HSPC were the sole population that maintained proliferative potential and undifferentiated state in bone marrow stroma co-culture, and engrafted in immunodeficient mice. GPI-80 expression also enabled tracking of HSC migration between human fetal hematopoietic niches. The most highly enriched surface protein in GPI-80+ HSPC as compared to their progeny was Integrin alpha-M (ITGAM), which in leukocytes cooperates with GPI-80 to support migration. Knockdown of either GPI-80 or ITGAM was sufficient to perturb undifferentiated HSPC in stroma co-culture. These findings indicate that human fetal HSC utilize common mechanisms with leukocytes for cell-cell interactions governing HSC self-renewal. We used microarrays to identify genes enriched in the CD90+ hematopoietic stem and progenitor population in fetal liver. RNA was extracted from enriched fetal liver hematopoietic stem and progenitor cells, and downstream progenitors, for comparison based on Affymetrix arrays.
Project description:To investigate whether liver-resident ILC1s could develop from local hematopoietic progenitors, we analyzed the phenotypic properties of liver CD45+Lin- progenitors. We found that the adult mouse liver contained Lin-Sca-1+Mac-1+ (LSM) hematopoietic progenitors derived from the fetal liver. This population included Lin-CD122+CD49a+ progenitors that could generate liver ILC1s but not conventional NK (cNK) cells. By performing single-cell RNA seq, we show the heterogeneous composition of these hematopoietic progenitors.
Project description:Advances in pluripotent stem cell and reprogramming technologies have given hope of generating hematopoietic stem cells (HSC) in culture. To succeed, greater understanding of the self-renewing HSC during human development is required. We discovered that glycophosphatidylinositol-anchored surface protein GPI-80 (Vanin 2) defines a distinct subpopulation of human fetal hematopoietic stem/progenitor cells (HSPC) with self-renewal ability. CD34+CD90+CD38-GPI-80+ HSPC were the sole population that maintained proliferative potential and undifferentiated state in bone marrow stroma co-culture, and engrafted in immunodeficient mice. GPI-80 expression also enabled tracking of HSC migration between human fetal hematopoietic niches. The most highly enriched surface protein in GPI-80+ HSPC as compared to their progeny was Integrin alpha-M (ITGAM), which in leukocytes cooperates with GPI-80 to support migration. Knockdown of either GPI-80 or ITGAM was sufficient to perturb undifferentiated HSPC in stroma co-culture. These findings indicate that human fetal HSC utilize common mechanisms with leukocytes for cell-cell interactions governing HSC self-renewal. We used microarrays to identify genes enriched in the CD90+ hematopoietic stem and progenitor population in fetal liver.