ABSTRACT
Regulated migration of hematopoietic stem cells is fundamental for hematopoiesis. The molecular mechanisms underlying stem cell trafficking are poorly defined. Based on a short hairpin RNA library and stromal cell-derived factor-1 (SDF-1) migration screening assay, we identified the histone 3 lysine 27 demethylase UTX (Kdm6a) as a novel regulator for hematopoietic cell migration. Using hematopoietic stem and progenitor cells from our conditional UTX knockout (KO) mice, we were able to confirm the regulatory function of UTX on cell migration. Moreover, adult female conditional UTX KO mice displayed myelodysplasia and splenic erythropoiesis, whereas UTX KO males showed no phenotype. During development, all UTX KO female and a portion of UTX KO male embryos developed a cardiac defect, cranioschisis, and died in utero. Therefore, UTY, the male homolog of UTX, can compensate for UTX in adults and partially during development. Additionally, we found that UTX knockdown in zebrafish significantly impairs SDF-1/CXCR4-dependent migration of primordial germ cells. Our data suggest that UTX is a critical regulator for stem cell migration and hematopoiesis.
Subject(s)
Cell Movement/genetics , Hematopoiesis/genetics , Hematopoietic Stem Cells/physiology , Histone Demethylases/physiology , Animals , Cells, Cultured , Embryo, Nonmammalian , Female , Gene Expression Regulation, Developmental/physiology , Gene Expression Regulation, Enzymologic/physiology , HEK293 Cells , Hematopoietic Stem Cells/metabolism , Histone Demethylases/genetics , Histone Demethylases/metabolism , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Zebrafish/embryology , Zebrafish/geneticsABSTRACT
Available treatment for Parkinson's disease (PD) is mainly symptomatic instead of halting or reversing degenerative processes affecting the disease. Research on the molecular pathogenesis of PD has suggested reduced trophic support as a possible cause or mediator of neurodegeneration. In animal models of the disease, neurotrophic factors prevent neurodegeneration and induce behavioral recovery. Some anti-Parkinsonian drugs show neuroprotective activity, but it is not known whether the drug-induced neuroprotection is mediated by neurotrophic factors. In this study, we have investigated the influence of two neuroprotective anti-Parkinsonian drugs, the monoamine oxidase B inhibitor selegiline and the adenosine A(2A) antagonist SCH 58261, on the levels of brain-derived neurotrophic factor (BDNF) and cerebral dopamine neurotrophic factor (CDNF) in the mouse brain. Protein levels of BDNF and CDNF were quantified by western blot after 2 weeks of treatment with either of the drugs or placebo. CDNF levels were not significantly influenced by selegiline or SCH 58261 in any brain area studied. Selegiline treatment significantly increased BDNF levels in the anterior cingulate cortex (1.55 +/- 0.22, P < 0.05, Student's t-test). In the striatum, selegiline increased BDNF content by 32%, but this change did not reach statistical significance (1.32 +/- 0.15, P < 0.13, Student's t-test). Our data suggest that neurotrophic factors, particularly BDNF may play a role in the neuroprotective effects of selegiline, but do not support the hypothesis that anti-Parkinsonian drugs would work by increasing the levels of CDNF in brain.
Subject(s)
Antiparkinson Agents/pharmacology , Brain-Derived Neurotrophic Factor/drug effects , Brain/drug effects , Nerve Growth Factors/drug effects , Neuroprotective Agents/pharmacology , Parkinson Disease/drug therapy , Adenosine A2 Receptor Antagonists , Animals , Blotting, Western , Brain/metabolism , Brain/physiopathology , Brain-Derived Neurotrophic Factor/metabolism , Corpus Striatum/drug effects , Corpus Striatum/metabolism , Cytoprotection/drug effects , Cytoprotection/physiology , Gyrus Cinguli/drug effects , Gyrus Cinguli/metabolism , Male , Mice , Mice, Inbred C57BL , Monoamine Oxidase Inhibitors/pharmacology , Nerve Growth Factors/metabolism , Pyrimidines/pharmacology , Receptor, Adenosine A2A/metabolism , Selegiline/pharmacology , Triazoles/pharmacology , Up-Regulation/drug effects , Up-Regulation/physiologyABSTRACT
BACKGROUND: Neonatal leukemia is a rare disease with an estimated prevalence of about one to five in a million neonates. The majority being acute myeloid leukemia (AML), neonatal leukemia can present with a variety of symptoms including hyperleucocytosis, cytopenia, hepatosplenomegaly, and skin infiltrates. Chromosomal rearrangements including mixed lineage leukemia (MLL) translocations are common in neonatal AML. CASE PRESENTATION: A female neonate born at 34 weeks gestation presented with cardiorespiratory failure, hepatosplenomegaly, pancytopenia, and coagulopathy. She required intensive care treatment including mechanical ventilation, high-dose catecholamine therapy, and multiple transfusions. Small intestinal biopsy obtained during laparotomy for meconium ileus revealed an infiltrate by an undifferentiated monoblastic, MLL-rearranged leukemia. No other manifestations of leukemia could be detected. After spontaneous clinical remission, lasting 5 months without any specific treatment, the patient presented with leukemia cutis and full-blown monoblastic leukemia. MLL-AF10-rearranged AML could be re-diagnosed and successfully treated with chemotherapy and hematopoietic stem cell transplantation. CONCLUSIONS: Our patient exhibited a unique manifestation of neonatal MLL-AF10 rearranged AML with cardiorespiratory failure and intestinal infiltration. It highlights the importance of leukemia in the differential diagnosis of neonatal distress, congenital hematological abnormalities, and skin lesions.