Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.6.5.2 (NQO1)
 6,196 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Heavy ion beams are a high-LET radiation that has greater biological effect than electron beams or X-rays. However, little is known about the effect of heavy ion beams on the proliferation and differentiation of human hematopoietic stem/progenitor cells (HSPCs). The present study examined the effect of heavy ion beams on gene expression in human HSPCs, especially during early stage of megakaryocytopoiesis. Human CD34+ cells were exposed to monoenergetic carbon-ion beams (290 MeV/nucleon, LET = 50 KeV/m) that were generated by an accelerator (Heavy Ion Medical Accelerator in Chiba). The expression of various genes related to early hematopoiesis, megakaryocytopoiesis/erythropoiesis, cytokine receptors and oxidative stress were analyzed by real-time RT-PCR. Friend leukemia virus integration 1, an early hematopoiesis-related gene, showed significantly higher mRNA expression than the control at 6 hr after irradiation. In contrast, no significant differences were observed in almost all of the other early hematopoiesis-related genes, cytokine receptor-coded genes and megakaryocytopoiesis/erythropoiesis-differentiation pathway-related genes, respectively. An analysis of the response of the genes to oxidative stress revealed the expression of heme oxygenase 1 to show a 1.5-fold and 11.9-fold increase from the day 0 control at 24 hr after 0.5 Gy and 2 Gy irradiation, respectively. Similarly, the NAD(P)H dehydrogenase-quinone 1 expression also showed a 22.0-fold and a 21.8-fold increase at 6 hr in comparison to the initial control. These results showed that the heavy ion beams affect megakaryocytopoiesis/ erythropoiesis differentiation of human HSPCs on the gene expression level.
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PMID:Heavy ion beam irradiation regulates the mRNA expression in megakaryocytopoiesis from human hematopoietic stem/progenitor cells. 1962 25

Hematopoietic processes, especially megakaryocytopoiesis and thrombopoiesis, are highly sensitive to extracellular oxidative stresses such as ionizing radiation and chemotherapeutic agents. This study examined the terminal maturation of megakaryocytes and platelet production in hematopoietic stem/progenitor cells (HSPCs) exposed to ionizing radiation. Highly purified CD34(+) cells derived from human placental/umbilical cord blood were exposed to X rays (2 Gy, 150 kVp, 20 mA; 0.5-mm aluminum and 0.3-mm copper filters) at a dose rate of approximately 1 Gy/min and then cultured in a serum-free medium supplemented with thrombopoietin and interleukin-3. The number of cells generated from X-irradiated CD34(+) cells decreased with the time in culture. However, the fraction of CD34(+)Tie-2(+) and CD41(+)Tie-2(+) cells among the total cells generated from X-irradiated cells increased significantly in comparison to nonirradiated controls on day 7. In addition, the CD42a(+) particles, which appeared to be platelets, generated from the X-irradiated HSPCs appeared to be normal. Quantitative real-time reverse transcriptase-polymerase chain reaction analysis of the expression of various genes in cells harvested from the cultures showed that the early hematopoiesis-related genes FLI1, HOXB4 and Tie-2, the cytokine receptor genes KIT and IL3RA, and the oxidative stress-related genes HO1 and NQO1 were upregulated on day 7. These results suggest that normal terminal maturation of megakaryocytes and platelet production occur in residual HSPCs after exposure to ionizing radiation despite the adverse effect of radiation on proliferation and differentiation of HSPCs. Ionizing radiation may have the potential to promote both megakaryocytopoiesis and thrombopoiesis.
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PMID:Megakaryocytopoiesis and thrombopoiesis in hematopoietic stem cells exposed to ionizing radiation. 2202 86