Search results for "Poiesis"

Macrophage protease-activated receptor 2 regulates fetal liver erythropoiesis in mice.

2020

AbstractDeficiencies in many coagulation factors and protease-activated receptors (PARs) affect embryonic development. We describe a defect in definitive erythropoiesis in PAR2-deficient mice. Embryonic PAR2 deficiency increases embryonic death associated with variably severe anemia in comparison with PAR2-expressing embryos. PAR2-deficient fetal livers display reduced macrophage densities, erythroblastic island areas, and messenger RNA expression levels of markers for erythropoiesis and macrophages. Coagulation factor synthesis in the liver coincides with expanding fetal liver hematopoiesis during midgestation, and embryonic factor VII (FVII) deficiency impairs liver macrophage development…

Hematopoietic peripheral circulating blood stem cells as an independent marker of good transfusion management in patients with β-thalassemia: results…

2016

Background Beyond hemoglobin (Hb) levels and performance status, further surrogate markers of appropriate transfusion management should improve the quality of thalassemia care. We investigated the levels of peripheral circulating CD34+ stem cells as an independent marker of appropriate hematopoietic balance in patients with thalassemia. Study design and methods Peripheral circulating CD34+ stem cells, colony-forming unitgranulocyte, erythrocyte, macrophage, magakaryocyte (CF-GEMM), colony-forming unitgranulocyte/macrophage (CFU-GM), and erythroidburst-forming units (BFU-E) were assayed, according to standard procedures. Patients with thalassemia major (TM) and thalassemia intermedia (TI) we…

X-linked protoporphyria: Iron supplementation improves protoporphyrin overload, liver damage and anaemia

2015

Prolonged Fasting Reduces IGF-1/PKA to Promote Hematopoietic-Stem-Cell-Based Regeneration and Reverse Immunosuppression

2016

SummaryImmune system defects are at the center of aging and a range of diseases. Here, we show that prolonged fasting reduces circulating IGF-1 levels and PKA activity in various cell populations, leading to signal transduction changes in long-term hematopoietic stem cells (LT-HSCs) and niche cells that promote stress resistance, self-renewal, and lineage-balanced regeneration. Multiple cycles of fasting abated the immunosuppression and mortality caused by chemotherapy and reversed age-dependent myeloid-bias in mice, in agreement with preliminary data on the protection of lymphocytes from chemotoxicity in fasting patients. The proregenerative effects of fasting on stem cells were recapitula…

PRR signaling during in vitro macrophage differentiation from progenitors modulates their subsequent response to inflammatory stimuli.

2017

Toll-like receptor (TLR) agonists drive hematopoietic stem and progenitor cells (HSPCs) to differentiate along the myeloid lineage in vitro and also in vivo following infection. In this study, we used an in vitro model of HSPC differentiation to investigate the functional consequences (cytokine production) that exposing HSPCs to various pathogen-associated molecular patterns (PAMPs) and Candida albicans cells have on the subsequently derived macrophages. Mouse HSPCs (Lin- cells) were cultured with GM-CSF to induce macrophage differentiation in the presence or absence of the following pattern recognition receptor (PRR) agonists: Pam3CSK4 (TLR2 ligand), LPS (TLR4 ligand), depleted zymosan (wh…

Leukemia-associated activating mutation of Flt3 expands dendritic cells and alters T cell responses

2016

Lau et al. show that the FLT3-ITD mutation directly affects dendritic cell development in preleukemic mice, indirectly modulating T cell homeostasis and supporting the expansion of regulatory T cells.

Organotypic Epigenetic Signature Predicts Bone and Marrow Niche Forming Capacity of Stromal Progenitors in a Novel Mouse Model in Vivo.

2012

Abstract Abstract 2987 Mesenchymal stem/progenitor cells (MSPCs) from numerous tissues are currently tested in clinical trials despite a limited understanding of their in vivo behavior. In this study we used MSPCs from adult and fetal tissues to select the appropriate source for clinical application. We asked whether MSPCs derived from human bone marrow (BM), white adipose tissue (WAT) and umbilical cord (UC), compared to skin fibroblasts, bear an equivalent bone and marrow niche formation potential with of in vivo. Furthermore we evaluated attraction and engraftment of murine as well as human hematopoietic stem/progenitor cells (HSPCs) into newly formed MSPC-derived niches. To elucidate po…

Acute Nonlymphocytic Leukemia in Adults: Pathophysiology, Status of Current Therapy, and New Approaches

1987

Recent information concerning the cell biology of leukemias has provided new insights into the pathophysiology and pathogenesis of acute leukemia, involving the detection of leukemia viruses, oncogenes and their products, and the discovery of factors supporting clonal leukemic growth. Murine, avian, and cat leukemia viruses are well characterized. To date, only HTLV I appears to be a likely candidate as a human leukemia virus. For both avian and murine viruses, there is a fundamental classification distinction between long-latency viruses (LLV) and acute transforming viruses (ATV). The ATV are replication defective and must be propagated with a helper virus. They have within their genome an…

Unique astrocyte ribbon in adult human brain contains neural stem cells but lacks chain migration

2003

The subventricular zone (SVZ) is a principal source of adult neural stem cells in the rodent brain, generating thousands of olfactory bulb neurons every day. If the adult human brain contains a comparable germinal region, this could have considerable implications for future neuroregenerative therapy. Stem cells have been isolated from the human brain, but the identity, organization and function of adult neural stem cells in the human SVZ are unknown. Here we describe a ribbon of SVZ astrocytes lining the lateral ventricles of the adult human brain that proliferate in vivo and behave as multipotent progenitor cells in vitro. This astrocytic ribbon has not been observed in other vertebrates s…

Hematologic effects of recombinant human granulocyte colony-stimulating factor in patients with malignancy.

1989

Abstract The effect of recombinant human granulocyte colony-stimulating factor (G-CSF) on hematologic parameters was evaluated in a phase I clinical study in 18 patients with advanced malignancy. G-CSF was administered once daily as a 30-minute infusion for 14 days; three patients each were treated at increasing dose levels of 1, 3, 10, 30, and 60 micrograms kg-1 day-1. A transient decrease in neutrophil and monocyte counts was observed immediately after the G-CSF infusion, followed by a dose-dependent increase of up to 15-fold. G-CSF-induced neutrophils exhibited an increased O2- radical production, and serum levels of enzymes related to granulocyte turnover, including lysozyme and elastas…