Increased erythropoiesis in polycythemia vera is associated with increased erythroid progenitor proliferation and increased phosphorylation of Akt/PKB
Increased erythropoiesis in polycythemia vera is associated with increased erythroid progenitor proliferation and increased phosphorylation of Akt/PKB
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DOI：
10.1016/j.exphem.2004.10.017
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发表时间：
2005-02-01
影响因子：
2.6
通讯作者：
Krantz, SB
中科院分区：
文献类型：
--
作者：
Dai, CH;Chung, IJ;Krantz, SB
目标。本研究旨在探讨真性红细胞增多症(PV)患者红细胞生成增加的机制。从正常人或PV患者外周血中分离纯化CD34(+)和红系集落形成细胞(ECFC)，在促红细胞生成素(EPO)存在下培养，生成红系祖细胞。用Ki-67染色检测细胞增殖，TUNEL法检测细胞凋亡率，免疫印迹法检测Akt/PKB和糖原合成酶激酶3(GSK3)的磷酸化。在液体培养中，真性红细胞增多症红系祖细胞比正常细胞多产生60%的细胞。TUNEL检测显示PV与正常红系祖细胞无差异，但Ki-67细胞增殖染色显示PV中有更多的阳性细胞。与干细胞因子(SCF)或促红细胞生成素(EPO)孵育后，415例PV患者第8天的红系祖细胞Akt/PKB的磷酸化水平显著高于正常细胞。与SCF或EPO孵育后，PV细胞中糖原合成酶3(GSK3)的α、β磷酸化程度也明显高于正常细胞。这些结果与先前报道的光伏细胞对干细胞因子和促红细胞生成素的超敏反应相似。PV患者红细胞生成增加与细胞增殖增加和Akt/PKB和GSK3磷酸化增加有关。这项研究为PV的发病机制和正常红细胞生成的调节提供了更多的洞察力，即使这种疾病的特定分子缺陷仍然不明显。(C)2005年国际实验血液学学会。由爱思唯尔公司出版。
Objective. The aim of this study was to explore the mechanism by which increased erythropoiesis occurs in polycythemia vera (PV).Methods. CD34(+) and erythroid colony-forming cells (ECFC) were purified from normal or PV peripheral blood and then incubated in the presence of erythropoietin (EPO) to generate erythroid progenitor cells. Measurement of proliferation by Ki-67 staining, TUNEL assays to measure apoptosis, and Western blots for detection of Akt/PKB and glycogen synthase kinase 3 (GSK3) phosphorylation were performed in both normal and PV erythroid progenitors.Results. Polycythemia vera erythroid progenitor cells generated 60% more cells compared to normal cells in liquid medium cell cultures. TUNEL assays revealed no difference between PV and normal erythroid progenitors, but Ki-67 staining for cell proliferation showed many more positive cells in the PV samples. A marked increase of phosphorylation of Akt/PKB occurred in the day-8 erythroid progenitors of 415 PV patients, compared to normal cells, after incubation with either stem cell factor (SCF) or EPO. PV cells also had much greater glycogen synthase kinase 3 (GSK3) alpha,beta phosphorylation compared to normal cells after incubation with SCF or EPO. These results are parallel to the cellular hypersensitivity of PV cells to SCF and EPO previously reported.Conclusions. Increased erythropoiesis in PV is associated with increased cellular proliferation and increased phosphorylation of Akt/PKB and GSK3. This study provides additional insight into the pathogenesis of PV and the regulation of normal erythropoiesis, even though a specific molecular defect of the disease is still not apparent. (C) 2005 International Society for Experimental Hematology. Published by Elsevier Inc.