造血干细胞分化过程中HOXB6基因表达及干预研究

目的探讨脐血造血干细胞(HSC)向粒-单系(CFU-GM)、红系(CFU-E)和淋巴系祖细胞(CFU-TL)增殖分化过程中HOXB6基因的表达情况及全反式维A酸(ATRA)对其的影响。方法1.采用造血干/祖细胞体外培养技术,以ATRA持续干扰人类脐血造血干/祖细胞,观察HSC经人粒细胞-单核细胞集落刺激因子(GM-CSF)、促红细胞生成素(EPO)和植物血凝素(PHA)分别诱导后,在培养第3天、第7天和第12天的CFU-GM、CFU-E及CFU-TL集落生成情况。2.采用实时荧光定量RT-PCR技术(FQ-RT-PCR)检测造血干细胞增殖分化过程中HOXB6基因的表达水平。结果1.人类造血干细胞向CFU-GM、CFU-E和CFU-TL增殖分化过程中,各组细胞HOXB6基因均有表达。2.随时间推移,CFU-GMHOXB6 mRNA在增殖分化的第3天开始表达,第7天表达最强烈,第12天表达明显减弱;CFU-E HOXB6 mRNA表达在第3天、第7天和第12天均持续增强;而在CFU-TL中,HOXB6 mRNA表达在第7天最强烈,第12天表达减弱。3.与对照组比较,ATRA可上调各组HOXB6基因的表达。结论1....     

全反式维甲酸对脐血粒-单系祖细胞HOXB6基因表达的影响

目的探讨脐血造血干祖细胞(HSPC)向粒-单系(CFU-GM)增殖过程中HOXB6mRNA表达及全反式维甲酸(ATRA)对HOXB6mRNA表达的影响。方法1.采用造血祖细胞体外培养技术,以ATRA持续干扰人类造血干祖细胞,观察人脐血HSPC经人粒细胞-单核细胞集落刺激因子(GM-CSF)诱导后,在培养过程第3天,7天和12天的CFU-GM集落生成情况。2.采用实时荧光定量PCR技术(FQ-RT-PCR)检测造血祖细胞增殖分化过程中HOXB6基因的表达水平。3.结果用DNA相对拷贝数和RNA表达相对量(2-△△Ct)表示HOXB6基因相对表达量。结果1.人类造血干祖细胞向粒单系增殖分化过程中,各组细胞HOXB6基因均表达;2.随时间延长,CFU-GM-HOXB6-mRNA在增殖分化的第7天表达最强烈,第12天表达明显减弱;3.与正常对照组比较,ATRA可上调HOXB6基因的表达。结论1.在脐血CFU-GM祖细胞的不同增殖阶段,HOXB6基因呈现持续稳定的表达,提示HOXB6是人类造血干祖细胞向粒单系正常增殖分化过程中的调控基因之一;2.ATRA能显著上调HOXB6基因的表达。     

脐血造血干祖细胞增殖过程中人类巨细胞病毒感染对hoxa9、hoxa10基因表达影响的研究

目的在基因水平探讨人类巨细胞病毒(HCMV)感染导致脐血CFU-G损伤的机制,探讨人类脐血造血干细胞(HSC)向粒系祖细胞(CFU-G)增殖过程中hoxa9、hoxa10基因表达的情况。方法从2006年5月至2007年10月收集12例正常足月顺产新生儿断脐后的胎盘段脐血,采用造血干细胞体外培养技术及荧光定量逆转录聚合酶链反应(FQ-RT-PCR)方法,以HCMV-AD169和(或)全反式维甲酸(ATRA)持续干扰HSC,观察正常对照组、ATRA组、HCMV-AD169组、ATRA+HCMV组的造血干祖细胞经人粒细胞集落刺激因子(G-CSF)诱导后,在增殖分化过程中第3、7和12天检测CFU-Ghoxa9、hoxa10基因表达情况。结果各组hoxa9、hoxa10基因均在CFU-G增殖分化的第7天表达量最高(P0.01),第12天表达量明显减弱(P0.01),与正常对照组比较,CFU-Ghoxa9、hoxa10基因表达受ATRA(6×10-8mol/L)上调,而受HCMV下调(P0.01),与HCMV组比较,ATRA可上调HCMV感染的CFU-Ghoxa9、hoxa10基因的表达。结论 CFU-G的增殖分化与hoxa9、hoxa10基因的表达相关。HCMV可能通过调控hoxa9、hoxa10基因表达异常引起造血功能异常,ATRA不仅能显著上调正常CFU-Ghoxa9、hoxa10基因的表达,而且能上调HCMV感染的CFU-Ghoxa9、hoxa10基因的表达。     

脐血粒系祖细胞发育过程同源盒基因B7的表达及干预

目的 探讨人类脐血造血干细胞向粒系祖细胞发育过程中同源盒(HOX)B7 mRNA和蛋白的表达及全反式维A酸(ATRA)和(或)三氧化二砷(As2O3)对脐血粒系祖细胞发育过程中HOXB7表达的影响.方法 采用实时荧光定量PCR(RT-PCR)、Western-blot技术测定空白对照组、ATRA组、As2O3组、ATRA+As2O3组造血干细胞向粒系祖细胞增殖过程中HOXB7 mRNA及蛋白表达水平.结果 1.琼脂糖凝胶电泳显示RNA电泳图的5 S,18 S,28 S 3条带型整齐,无明显拖尾及弥散,说明RNA结构完整,无明显降解.2.反转录PCR扩增各组均有目的 基因HOXB7和内参照ACTB基因的cDNA产物,与DNA分子Marker相比扩增产物大小分别如下:HOXB7为129 bp,ACTB基因为111 bp,与预定理论值大小符合.3.人类造血干细胞向粒系祖细胞增殖分化过程中,空白对照组、ATRA组、As2O3组及ATRA+As2O3组的HOXB7 mRNA第3天少量表达,第7天表达较强烈,第12天表达减弱;空白对照组、ATRA组的HOXB7蛋白在增殖分化的第3天少量表达,第7天表达较高,第12天表达减弱,As2O3组及ATRA+As2O3组的HOXB7蛋白的表达在各时间点无明显差异.4.与空白对照组比较,ATRA组HOXB7 mRNA及蛋白的表达上调(P<0.05),而As2O3组HOXB7的表达无明显差异(P>0.05).结论 HOXB7基因可能是人类造血干祖细胞向粒系祖细胞增殖分化过程的调控基因之一,HOXB7基因与粒系造血有相关性.ATRA治疗白血病的作用可能与调节HOX基因的表达有关.As2O3对HOXB7 mRNA及蛋白的表达无明显调节作用.     

经人类巨细胞病毒感染的人脐血造血干细胞向淋巴系造血祖细胞增殖分化过程中同源盒b4、b6基因的表达

目的 探讨经人类巨细胞病毒(HCMV)感染的人脐血造血干细胞(HSC)向淋巴系造血祖细胞(CFU-TL)增殖分化过程中同源盒(hox)b4、b6基因的表达.方法 取健康母亲健康足月顺产儿断脐后的胎盘段脐血,采用造血祖细胞体外培养技术,分组以HCMV-AD169病毒液和(或)全反式维A酸(ATRA)持续干预,观察其不同时间点各组细胞集落生成情况,并在鉴定为CFU-TL集落细胞后不同时间点分别提取各组细胞核精核酸(RNA)并检测其完整性;将提取到的总RNA反转录为互补脱氧核糖核酸,在不同时间点采用实时荧光定量反转录PCR(FQ-RT-PCR)技术检测各组hoxb4、hoxb6基因的表达.结果 1.培养的集落细胞经瑞-姬染色法染色,鉴定为CFU-TL.2.各组所提取的RNA结构基本完整.3.人脐血HSC向CFU-TL增殖分化过程中(体外),各组hoxb4、hoxb6基因均有表达.且随培养时间推移,hoxb4基因表达的相对水平逐渐降低;而hoxb6基因表达的相对水平在培养第7天最高,第12天降低.4.与空白对照组比较,ATRA组的hoxb4、hoxb6基因表达的相对水平显著增高,而HCMV组的hoxb4、hoxb6基因表达的相对水平较低.5.与HCMV组比较,HCMV加ATRA组的hoxb4、hoxb6基因表达的相对水平较高.结论 1.hoxb4、hoxb6基因在人脐血HSC向CFU-TL增殖分化过程中(体外)均有表达,提示其均与淋巴系统造血密切相关.2.HCMV能下调CFU-TL hoxb4、hoxb6基因的表达(体外),提爪HCMV可能通过调控hoxb4、hoxb6基因表达异常导致造血功能异常.3.ATRA能显著上调正常CFU-TLhoxb4、hoxb6基因的表达.实用儿科临床杂志,2009,24(10):757-759     

同源盒基因A簇及其与白血病的关系研究进展

同源盒基因(HOX)是一类控制胚胎发育和细胞分化的调节基因,参与造血干/祖细胞的增殖、分化、成熟等的调控。HOX基因A簇是造血干/祖细胞增殖分化的主控基因,可影响造血干细胞的数量,参与造血干细胞向红系、粒系、巨核系与淋巴系的分化,并可能是导致白血病发病的靶基因。现就有关HOX基因A簇及其与白血病的关系研究进展综述如下。     

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目的研究脐血红系祖细胞的HOXB6基因的表达情况以及人类巨细胞病毒(HCMV)感染对红系祖细胞的HOXB6基因表达的影响,以探讨HCMV导致脐血红系祖细胞损伤的机制。方法在泸州医学院附属医院儿科以实时荧光定量PCR技术(FQ-RT-PCR)检测人类巨细胞病毒感染和(或)用全反式维甲酸(ATRA)处理后HOXB6基因的表达水平。结果人脐血红系祖细胞可表达HOXB6基因;HCMV感染后,红系祖细胞HOXB6基因的表达明显下调;ATRA能显著上调红系祖细胞HOXB6基因的表达水平,且能够在一定时间内上调HCMV感染后的红系祖细胞HOXB6基因的表达。结论HCMV感染能诱导脐血红系祖细胞HOXB6的表达下调,HC-MV有可能通过调控HOXB6基因表达异常而引起红系祖细胞的增殖障碍。     

同源盒基因B簇在造血干/祖细胞增殖分化中的作用

同源盒(HOX)基因是造血干/祖细胞增殖分化的主控基因。HOX基因参与造血调控且与造血细胞发育有关,影响造血干细胞的数量和红系、粒系、巨核系及淋巴系增殖分化。本文综述HOX基因结构特征及HOX基因B簇中的HOXB2、HOXB3、HOXB4、HOXB6、HOXB8在造血干/祖细胞增殖分化中的作用。     

人类巨细胞病毒对粒单系祖细胞分化过程中HOXB6、A5基因的影响

目的探讨人类造血干细胞(HSPC)向粒单系(CFU-GM)增殖过程中HOXB6、A5基因的表达情况,及人类巨细胞病毒(HCMV)对其的影响。方法采用real-timePCR技术测定正常对照组与HCMV组HSPC向CFU-GM增殖过程中HOXB6、A5基因的表达水平。结果①HOXA5基因表达多为阴性,HOXB6基因在增殖过程的第3天开始表达,第7天增高,第12天显著降低(P<0.05)。②相对于正常组,HCMV感染组HOXB6基因表达下调(P<0.05)。结论HOXA5可能不是人类HSPC向CFU-GM增殖分化过程的主控基因;HOXB6是人类HSPC向CFU-GM定向分化的主控基因之一,其表达呈现时间规律性;HCMV干扰的细胞组HOXB6表达下调的同时,其细胞集落生成较正常组差。提示HCMV可能通过调控HOXB6基因表达异常,引起造血干细胞增殖分化异常。     

人脐血间充质干细胞对脐血CD+34细胞体外扩增作用的研究

目的 探讨含人脐血来源的间充质干细胞(MSCs)体系在体外对脐血造血干细胞(HSCs)扩增作用。方法 (1)用含人脐血MSCs及不同造血生长因子(HGFs)组合的无血清扩增体系对人脐血CD34^ 细胞进行体外扩增。(2)于扩增前及扩增后第6、12天分别用双色流式细胞仪动态检测HSCs表面抗原标记：CD34^ 、CD34^ CD38^-、CD34^ CD3^ 、CD34^ CD19^ 、CD34^ 和CD34^ CD41^ 。细胞的含量。(3)按本实验室方法行体外半固体培养,观察扩增前后脐血细胞粒-单核细胞集落形成单位(CFU-GM)、爆式红系集落形成单位(BFU-E)、混合集落形成单位(CFU-Mix)及高增殖集落形成单位(CFU-HPP)集落形成情况。结果(1)含人脐血MSCs体系对脐血CD34^ CD38^ 细胞的扩增倍数在第6天和第12大分别为159和437倍。该业群百分比在单纯因子组扩增第12天时为1．98％,而在含脐血MSCs组为9．98%,明显高于扩增前。(2)集落培养表明,含脐血MSCs组扩增第12天与扩增第6天相比,其CFU-Mix和CFU-HPP的扩增倍数增加,而单纯因子组这两种集落的扩增倍数下降。(3)随扩增天数的增加,两组扩增体系中CD34^ CD3^ 和CD34^ CD41a^ 细胞均明显增加,而CD34^ CD19^ 和CD34^ CD3^ 细胞均明显减少。两组相比,含脐血MSCs组差异更显著。结论 (1)含脐血MSCs体系不仅能扩增更原始的造血干／祖细胞(HSPC),且具有在短期内(12d)保持HSCs不耗竭。(2)含脐血MSCs体系对脐血CD34^ 细胞向定向祖细胞的扩增,主要为髓系及巨核系祖细胞,而对其向淋巴系祖细胞的扩增具有抑制作用。     

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??Abstract??Objective??To observe the expression of hoxa9 gene and hoxa10 gene in the process of the differentiation and proliferation of hematopoietic stem cell to Colony Forming Unit-Granulocyte??CFU-G??in vitro??and to explore the possible mechanism of HCMV-induced maldevelopment to human cord blood Granulocyte Progenitor in genic level. Methods??Twelve cases of cord blood were collected from fetal placenta umbilical vein. By the colony culture in vitro?? the impact of HCMV-AD169 and ATRA on the CFU-G colony formation was observed?? then detect the expression of hoxa9 and hoxa10 genes in the differentiation progress of Hematopoietic Stem Cell ??HSC?? to CFU-G affected by HCMV and/or ATRA on the third?? seventh?? and twelfth day. Results??Homeobox genes did have a regulatory function in the differentiation process of hematopoiesis. Compared with the expression of hoxa9 and hoxa10 genes on day 3?? the quantity of hoxa9 and hoxa10 genes was obviously higher on day 7 and lower on day 12 respectively in each group. Compared with the expression of hoxa9 and hoxa10 genes of normal group?? the expression of hoxa9 and hoxa10 of the group ATRA was up-regulated remarkably??while the expression of hoxa9 and hoxa10 of the group HCMV was down-regulated. ATRA was against the down-regulated effect caused by HCMV. Conclusion??The hoxa9 and hoxa10 gene are correlated to the manipulation of the proliferation and differentiation of granulocyte progenitor cell. The abnormal expression of hoxa9 and hoxa10 gene induced by HCMV may play an important role in HCMV-induced abnormal hematogenic damage. ATRA?? 6×10-8 mol/L??can up-regulate the expression of hoxa9 and hoxa10 genes??which confirms the theory that the normal hematopoietic lineage determination and maturation rely on the stable and consistently expression of Homeobox genes.     

胚胎干细胞诱导分化为造血干细胞重建造血功能的作用

目的探讨胚胎干细胞（ESC）定向分化来源的造血干细胞（HSC）体内重建造血功能的作用。方法将小鼠E14.1胚胎干细胞采用三步诱导法在体外分化发育为HSC,流式细胞仪检测HSC表面标志性抗原CD34^＋/Sca-1^＋的表达,体内畸胎瘤形成实验检测其致瘤性,造血克隆形成（CFU）实验观察其体外造血集落形成情况,免疫磁珠分选纯化HSC移植给经亚致死剂量γ射线照射的雌性小鼠观察其体内重建造血的功能。结果多种造血刺激因子联合应用能有效促进ESC发育为含丰富造血前体细胞的胚胎体（EB）,诱导14 d后,EB中CD34^＋/Sca-1^＋细胞数达峰值,为（13.72&#177;2.07）%。收获此阶段的EB行第二步诱导分化16 d后,CD34^＋/Sca-1^＋细胞数可增至（24.62&#177;2.50）%,CFU培养出现红系和粒系造血克隆;在骨髓基质细胞加胎肝基质细胞上清液培养体系中进行第三步诱导分化15 d后,CD34^＋/Sca-1^＋细胞达峰值,为（58.64&#177;4.20）%,CFU培养能形成较多的红系、粒系/巨噬细胞系及混合细胞集落,W right-G iemsa染色显示为原始的造血细胞。此阶段的HSC经分选纯化后移植给经γ射线照射后的小鼠,移植组小鼠＋10 d造血功能开始恢复,观察40 d后除血小板恢复较慢外,白细胞、红细胞、血红蛋白等指标已接近正常,植入率为71.4%,存活率为43.0%,染色体检测证实已由受体鼠的XX转为供体鼠的XY。结论采用分阶段诱导的方法,可在体外定向诱导小鼠ESC分化发育为HSC,此来源的HSC较安全,无致瘤性,并具备体内重建造血功能的能力。     

Cord blood stem cell banking and transplantation

Stem cells have the ability to divide for indefinite periods in culture and to give rise to specialized cells. Cord blood as a source of hematopoietic stem cells (HSC) has several advantages as it is easily available, involves non-invasive collection procedure and is better tolerated across the HLA barrier. Since the first cord blood transplant in 1988, over 2500 cord blood HSC transplants have been done world wide. Since then, the advantages of cord blood as a source of hematopietic stem cells for transplantation have become clear. Firstly, the proliferative capacity of HSC in cord blood is superior to that of cells in bone marrow or blood from adults. A 100 ml unit of cord blood contains 1/10^th the number of nucleated cells and progenitor cells (CD34+ cells) present in 1000 ml of bone marrow, but because they proliferate rapidly, the stem cell in a single unit of cord blood can reconstitute the entire haematopoietic system. Secondly, the use of cord blood reduces the risk of graft vs host disease. Cord Blood Stem Cell banks have been established in Europe and United States to supply HSC for related and unrelated donors. Currently, more than 65000 units are available and more than 2500 patients have received transplants of cord blood. Results in children have clearly shown that the number of nucleated cells in the infused cord blood influences the speed of recovery of neutrophils and platelets after myeloablative chemotherapy. The optimal dose is about 2 x 10⁷ nucleated cells/kg of body weight. The present study was carried out for collection, separation, enumeration and cryopreservation of cord blood HSC and establishing a Cord Blood HSC Bank. 172 samples of cord blood HSC were collected after delivery of infant prior to expulsion of placenta. The average cord blood volume collected was 101.20 ml. Mononuclear cell count ranged from 7.36 to 25.6 x 10⁷/ml. Viability count of mononuclear cells was 98.1%. After 1 year of cryopreservation, the viability count on revival was over 82.1 %. Related cord blood stem cell transplantation was carried out in three cases at Army Hospital (R & R), Delhi Cantt.     

Hematopoietic hormones: from cloning to clinic

In order to maintain adequate circulating numbers of blood cells, the bone marrow must produce billions of cells each day and must be able to rapidly increase production by 10-20-fold in response to infection and hemorrhage. The existence of circulating factors that regulate this process has been suspected for over 100 years. Recently, the genes encoding these growth factors were cloned and their functions are now identified. Interleukin-3 (IL-3) acts on the most primitive hematopoietic stem cell, driving this self-renewing cell to produce progeny of all hematopoietic lineages. Granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulates the granulocyte-macrophage progenitor cell, as well as cells committed to the erythroid lineage, to differentiate. G-CSF and M-CSF stimulate the most differentiated myeloid progenitors to produce granulocytes and monocytes/macrophages, respectively. Erythropoietin stimulates the differentiation of late erythroid progenitors. In the lymphoid progenitor lineage, IL-2 stimulates T cell differentiation; IL-4 and IL-6 stimulate differentiation of B cells. The colony-stimulating factors also enhance function and cause activation of the mature cells whose production they induce. In clinical trials, these hormones have successfully ameliorated anemia in renal failure, chronic disease, and in prematurity. They have improved pancytopenias in aplastic anemia, myelodysplastic syndromes, and congenital cytopenias, and they have hastened recovery from chemotherapy and bone marrow transplantation.     

Sonic hedgehog signaling coordinates the proliferation and differentiation of neural stem/progenitor cells by regulating cell cycle kinetics during development of the neocortex

Sonic hedgehog (Shh) acts as a morphogen in normal development of various vertebrate tissues and organs. Shh signaling is essential for patterning and cell-fate specification, particularly in the central nervous system. Shh signaling plays different roles depending on its concentration, area, and timing of exposure. During the development of the neocortex, a low level of Shh is expressed in the neural stem/progenitor cells as well as in mature neurons in the dorsal telencephalon. Shh signaling in neocortex development has been shown to regulate cell cycle kinetics of radial glial cells and intermediate progenitor cells, thereby maintaining the proliferation, survival and differentiation of neurons in the neocortex. During the development of the telencephalon, endogenous Shh signaling is involved in the transition of slow-cycling neural stem cells to fast-cycling neural progenitor cells. It seems that high-level Shh signaling in the ventral telencephalon is essential for ventral specification, while low-level Shh signaling in the dorsal telencephalon plays important roles in the fine-tuning of cell cycle kinetics. The Shh levels and multiple functions of Shh signaling are important for proper corticogenesis in the developing brain. The present paper discusses the roles of Shh signaling in the proliferation and differentiation of neural stem/progenitor cells.     

人巨细胞病毒抑制粒-单及红系祖细胞的体外增殖及干预研究

探讨人巨细胞病毒 (HCMV)抑制脐血粒 -单系祖细胞的 (CFU GM)、红系爆式祖细胞 (BFU E)及红系祖细胞 (CFU E)的体外增殖和黄芪注射液与更昔洛韦(GCV)对此的干预作用 ,采用造血祖细胞体外培养、聚合酶链反应 (PCR)技术 ,培养、观察、计数CFU GM、BFU E及CFU E集落产率、抑制率、提高率 ,集落峰值时间和集落维持时间 ,并用PCR检测集落细胞内HCMV DNA。结果显示 :①HCMVAD169对CFU GM、BFU E及CFU E均有抑制作用 ,其抑制作用与HCMV浓度有关 ,高浓度 ( 1∶1 0 ,1 1 0 0 )感染组与对照组比较集落产率明显下降 (P <0 0 1 ) ,集落维持的时间明显缩短 (P <0 0 1 ) ,集落峰值时间无明显差异 (P >0 0 5) ,而低浓度组 ( 1∶1 0 0 0 )无此作用 ;②PCR检测发现在HCMV感染的造血祖细胞内存在HCMV DNA ;③在 1∶1 0感染组中 ,加入黄芪注射液与更昔洛韦后 ,HCMVAD169感染的CFU GM、BFU E及CFU E集落产率明显增加 (P <0 0 1 )。结论 :①造血祖细胞是HCMVAD169的宿主细胞之一 ,HCMVAD169能直接感染造血祖细胞 ;②在体外HCMVAD169对CFU GM、BFU E、CFU E的生长 ,集落形成有明显的抑制作用 ;③黄芪与更昔洛韦有抗HCMV作用 ,能促进受HCMV感染的造血祖细胞集落增殖