Project description:Erythropoiesis takes place mostly in bone marrow and ends in blood. Previous studies have shown that hypoxia has direct effects on the bone marrow, which could promotes erythropoiesis by modulating erythroid progenitor maturation. However, how bone marrow microenvironment participates in erythropoiesis under hypoxia still need further clarification. In this study, we analyzed transcriptional changes of bone marrow cells of mice exposed to 5000 m altitude hypoxia for 1 week. We profiled the top 20 up-regulated secreted factor genes after treatment with hypoxia, and found TFPI was one of the secreted factor genes with the highest expression.
Project description:Metabolic requirements vary during tissue development, but little is known whether and how metabolic rewiring orchestrates lineage differentiation and maturation. We discovered an essential metabolic switch from glutamine catabolism to glutamine synthesis during erythropoiesis. Glutamine synthetase (GS), one of the oldest functioning genes, is induced during terminal maturation to promote detoxification of ammonia generated during heme biosynthesis, which is massively upregulated to support hemoglobin production. Loss of GS in mouse erythroid precursors causes ammonia accumulation, oxidative stress, leading to maturation arrest and apoptosis. In β-thalassemia, GS activity is impaired by protein oxidation, causing glutamate and ammonia accumulation, whereas enforced GS expression alleviates the metabolic and pathologic defects. These results identify an evolutionarily conserved metabolic adaptation that may be leveraged to treat common red cell disorders.
Project description:Erythropoiesis occurs first in the yolk sac as a transit “primitive” form, then is gradually re-placed by the “definitive” form in the fetal liver (FL) during fetal development and in the bone marrow (BM) postnatal. While it is well known that differences exist between primitive and de-finitive erythropoiesis, the similarities and differences between FL and BM definitive erythropoi-esis have not been studied. Here we performed comprehensive comparisons of erythroid progen-itors and precursors at all maturational stages sorted from E16.5 FL and adult BM. Transcriptome comparison revealed that genes with increased expression in FL BFU-E were en-riched in cell division. Interestingly, the expression levels of glucocorticoid receptor Nr3c1, Myc and Myc downstream target Ccna2, were significantly higher in FL BFU-E, indicating the role of Nr3c1-Myc-Ccna2 axis in the enhanced proliferation/cell division of FL BFU-E cells. At the CFU-E stage, the expression of genes associated with hemoglobin biosynthesis were much higher in FL CFU-E, indicating more hemoglobin production. During terminal erythropoiesis, overall temporal patterns in gene expression were conserved between FL and BM. While biological pro-cesses related to translation, TCA and hypoxia response were upregulated in FL erythroblasts, that related to antiviral signal pathway were upregulated in BM erythroblasts. Our findings un-covered previously unrecognized differences between FL and BM definitive erythropoiesis and provide novel insights into erythropoiesis.
Project description:Mouse bone marrow derived dendritic cells were generated by culturing bone marrow cells at a density of 0.5x10E6 cells/ml in RPMI-1640 supplemented with 5% FCS, 1% Pen/Strep, 5microM 2-mercaptoethanol, 20ng/ml GM-CSF. At day 7 dendritic cells were stimulated or not with 500 ng/ml LPS, and collected at day 10.
2x10E8 cells were used to prepare whole cell extracts and to perform PU.1 immunoprecipitaion with PU.1 antibody (T-21 Santa Cruz). IgG was used as control.
Project description:RATIONALE: Radiation therapy uses high-energy x-rays to damage cancer cells. Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Combining chemotherapy with bone marrow transplantation may allow the doctor to give higher doses of chemotherapy drugs and kill more tumor cells.
PURPOSE: Phase II trial to study the effectiveness of bone marrow transplantation in treating patients who have hematologic cancer.