胎肝Sca-1+细胞移植造血重建

目的:观察胚胎肝Sca-1+细胞能否重建造血。方法:免疫磁珠法分离孕14 5dC57BL/6J小鼠的雄性胚胎肝的Sac-1+细胞,经尾静脉注射(细胞数为2 0×103/只)移植到致死剂量(10 0Gy)放射线照射的8～10周C57BL/6J雌性小鼠;sry基因PCR方法检测受体小鼠外周血中供体来源的血细胞。结果:移植胚胎肝Sca-1+细胞的实验组小鼠外周血各种血细胞数在5d后开始下降,在10d后开始上升,20d恢复至正常,均存活6个月以上;而未移植Sca-1+造血干细胞的对照组小鼠20d内全部死亡。多聚酶链式反应(PCR)显示实验组小鼠外周血细胞sry基因检测阳性,未移植对照组小鼠外周血细胞sry基因检测均为阴性;随着移植时间的延长,移植小鼠外周血细胞sry基因的PCR扩增物量增加,说明雄性胚胎供体来源的细胞在增加,反映造血重建情况。结论:胚胎肝Sca-1+细胞能重建致死剂量放射线照射的小鼠造血功能。     

睾丸素对粒系造血祖细胞的影响

应用造血细胞集落体内外培养技术，研究了睾丸素对小鼠粒系造血祖细胞的体内外影响。实验结果表明，把辜丸素直接加到琼脂扩散盒培养体系中，辜丸素对粒系造血祖细胞有刺激细胞增殖，提高细胞集落数量的效应；然而在整体情况下，切除成年小鼠辜丸消除体内睾丸素的影响，则未发现对粒系造血祖细胞有任何显著的影响。     

调节造血干细胞的蛋白质

科学家研究发现了一个小鼠蛋白质，它是形成所有的血细胞(包括免疫系统细胞)的干细胞存活所必需的。这些“造血干细胞”的丰富程度不仅仅由干细胞增生所决定，也取决于发育的细胞是否经历程序性的细胞死亡(凋亡)。研究人员表示，蛋白质MCL-1是造血干细胞凋亡的一个关键调节因子。     

骨髓造血微环境与基质细胞的基因治疗

造血干细胞是所有免疫细胞和血细胞的来源，而造血微环境是造血干细胞增殖、发育和分化的场所，对造血干细胞发育为成熟血细胞起重要的调节作用。造血微环境（HematopoieticMicroenvironment，HME）的概念1970年首先由坦廷（Tentin）提出，当时认为它由骨髓中微血管系统、神经、网状细胞、细胞外基质及纤维组织等构成，对造血干细胞的分化成熟起调节作用。以后的研究证明，微环境中的基质细胞（StrormalCell，SC）及一些造血刺激因子是造血微环境的主要成份。1977年德克斯特（Dexter）建立了体外长期骨髓细胞培养系统地Long-TermBoneM…     

造血干细胞免疫表型特征的研究进展(综述)

造血干细胞（ＨＳＣ）是一群具有高度自我更新和多向分化潜能的造血前体细胞。临床上常采用不同来源的造血干细胞进行输注移植，以治疗各种疾病。另外，由于造血干细胞的特殊性能，它们可作为基因治疗最理想的靶细胞，在治疗遗传性疾病、恶性肿瘤、严重免疫缺陷及感染性疾病等方面具有广阔的应用前景。因此，造血干／祖细胞的分离纯化、增殖分化性能及体外扩增等方面的研究是近年来备受关注的研究课题。现已知造血于细胞是由一群不均一的细胞群体所组成，不同年龄等级的造血干细胞的表面抗原、免疫表型表达各不相同，生物学特征也有一定的差…     

骨髓基质细胞的生物学特性及应用潜能

骨髓基质细胞(BMSCs)是骨髓中造血干细胞(HSC)以外的非造血干细胞.研究发现其具有贴壁生长的特性、自我更新的能力和多分化潜能.大量的实验研究表明,骨髓基质细胞在细胞治疗、基因治疗、组织工程等方面有广阔的应用前景.     

白鲜皮提取物对辐射损伤小鼠造血功能的保护作用

目的探讨白鲜皮乙醇提取物(AEDP)对辐射损伤小鼠造血系统的保护作用.方法将60只ICR小鼠随机分为正常对照组(NC)、照射对照组(IC)、AEDP低剂量(300 mg/kg)照射组(LI)、AEDP高剂量(600 mg/kg)照射组(HI)、AEDP低剂量(300 mg/kg)组(LD)、AEDP高剂量(600 mg/kg)组(HD),共6组,测定小鼠外周血白细胞数、骨髓有核细胞数、血清中铁含量.结果与照射对照组比较,AEDP高、低剂量组小鼠外周血白细胞数、骨髓有核细胞数显著增加(P0.05),血清中铁含量明显降低(P0.05).结论 AEDP可有效缓解辐射对造血系统造成的损伤.     

小鼠造血干细胞的分离、培养及重组慢病毒载体介导的离体hFⅨ基因表达

造血干细胞是基因治疗理想的靶细胞之一,尤其适用于遗传性血液病.而重组慢病毒载体能高效感染造血干细胞,成为造血干细胞途径基因治疗的理想载体.从小鼠骨髓细胞中分离出单个核细胞(MNCs)进行体外悬浮培养,并用免疫磁珠法分离得到高纯度的小鼠Lin-CD117+造血干细胞(HSCs).体外悬浮培养期间,添加细胞因子的造血干细胞的细胞数和集落数逐渐增加,而未添加细胞因子的对照组的细胞数量无明显增加,细胞集落递减.用磷酸钙介导的共转染法制备了携带FⅨ基因的FUXW重组慢病毒,用慢病毒载体分别感染从ICR小鼠和C57小鼠中分离得到的MNCs,7d后测得细胞上清中hFⅨ的表达量分别为41.7±4.2和34.5±6.6ng/mL,而慢病毒感染C57小鼠造血干细胞,添加细胞因子组上清中hFⅨ的表达量为46.6±5.7ng/mL,不添加细胞因子组为33.3±4.8ng/mL.实验结果表明,重组FUXW慢病毒载体可有效感染小鼠单个核细胞和Lin-CD117+造血干细胞,添加细胞因子可提高转移基因的表达量.     

造血干细胞的研究进展

干细胞是一类具有自我更新、高度增殖和多向分化潜能的原始细胞．造血干细胞在胚胎时期的发生、发育过程已得到进一步阐明．造血干细胞的移植已成功的应用于治疗多种血液系统和相关系统疾病．作者对造血干细胞的来源、细胞表面标志和其临床应用前景进行了综述．     

发酵黄腐酸对突变及对造血功能的影响

以小鼠骨髓嗜多染红细胞微核率（ＰＣＥ ＭＮＲ）和骨髓有核细胞数为指标对发酵黄腐酸（ＢＦＡ）和矿源黄腐酸（ＭＦＡ）进行了致突变作用和对造血系统影响的检测,结果结果表明,ＢＦＡ和ＭＦＡ本身无诱变性,可作为食品添加剂,饲料添加剂及药品使用。而且在给小鼠致变环磷酰胺时,ＢＦＡ可抑制突变率,保护分裂细胞,提高造血机能,并有一定的正向量效关系,在较大量使用时无毒副作用,ＭＦＡ也可抑制突变,保护分裂细胞,但在较     

P-选择素/P-选择素糖蛋白配体-1与骨髓祖细胞胸腺归巢

骨髓衍生的祖细胞归巢入胸腺是T细胞发育必需的过程,因为胸腺不包含具有自我更新能力的造血干细胞,它需要从血液中添补祖细胞,此过程依赖多级细胞粘附分子和趋化因子的衔接.细胞粘附分子选择素和它的配体PSGL-1在淋巴样祖细胞归巢入胸腺的过程中发挥重要作用.综述了选择素/配体PSGL-1的生物学特征及其相互作用对骨髓祖细胞胸腺归巢及胸腺-骨髓反馈环的影响和作用机制.     

Endothelial and perivascular cells maintain haematopoietic stem cells

Several cell types have been proposed to create niches for haematopoietic stem cells (HSCs). However, the expression patterns of HSC maintenance factors have not been systematically studied and no such factor has been conditionally deleted from any candidate niche cell. Thus, the cellular sources of these factors are undetermined. Stem cell factor (SCF; also known as KITL) is a key niche component that maintains HSCs. Here, using Scf(gfp) knock-in mice, we found that Scf was primarily expressed by perivascular cells throughout the bone marrow. HSC frequency and function were not affected when Scf was conditionally deleted from haematopoietic cells, osteoblasts, nestin-cre- or nestin-creER-expressing cells. However, HSCs were depleted from bone marrow when Scf was deleted from endothelial cells or leptin receptor (Lepr)-expressing perivascular stromal cells. Most HSCs were lost when Scf was deleted from both endothelial and Lepr-expressing perivascular cells. Thus, HSCs reside in a perivascular niche in which multiple cell types express factors that promote HSC maintenance.     

Effect of Spatholobus suberectus Dunn on proliferation of progenitor cells in mice with bone marrow depression

AIM： To study the effect of Spatholobus suberectus Dunn on the prolilferation and hematonic mechanism of Spatholobus suberectus Dunn. Methods： The techniques of culture of hematopoietic cell and hematopoietic growth factor （HGF） assay were used. The method of semi-solid culture with methylcellulose of CFU-GM, CFU-E, BFU-E, CFU-Meg was adopted in bone marrow depressed mice which treated with Spatholobus suberectus Dunn for a long time. Results： Spatholobus suberectus Dunn could obviously promote the proliferation of bone morrow cells and spleen lymphocytes in healthy and anaemic mice. The cuhure medium of spleen cell, macrophage, lung and skeletal muscle treated with Spatholobus suberectus Dunn had much stronger stimulating effects on hematopoietic cells. The numbers of CFU-GM, CFU-E, BFU-E, CFU-Meg in bone marrow depressed mice were raised distinctly under the control of Spatholobus suberectus Dunn as compared with those of contrast group. Conclusions： Spatholobus suberectus Dunn may enhance hematopoiesis by stimulating directly and/or indirectly stroma cell in hematopoietic inductive microenvironment and muscle tissue to secrete some HGF （Epo, GM-CSF, IL, and MK-CSF）. It can promote the proliferation and differentiation of hematopoietic cells in anaemic mice. This is one of the biological mechanisms for hematonic effect of Spatholobus suberectus Dunn.     

人脐带间充质干细胞对小鼠衰老进程中骨髓细胞集落生成的影响

目的:探讨人脐带间充质干细胞(hUC-MSC)对小鼠衰老进程中骨髓造血干祖细胞增殖能力的影响.方法:由足月新生儿脐带分离间充质细胞(MSC)作供体,6月龄Balb/c小鼠为受体,将小鼠随机分为实验组和对照组,实验组输注MSC(5×10~5/只),每月1次,共4次;对照组输注生理盐水.干预开始后第3个月和第6个月分别比较两组的单侧股骨骨髓有核细胞计数(BMNC)、造血祖细胞集落培养(CFU-GM、CFU-E、CFU-MK)和外源性脾集落形成单位计数(CFU-S).结果:干预后第3个月时,实验组BMNC、CFU-GM和CFU-MK高于对照组,而CFU-E和CFU-S无明显差别;干预后第6个月时,实验组的上述指标均明显高于对照组,且随着衰老出现下降的速度明显慢于对照组,差异有显著性(P<0.05).结论:定期输注hUC-MSC可以相对增加宿主自身造血干祖细胞的生物学活性,从而延缓小鼠造血组织的自然衰老进程.     

八珍汤和鸡血藤对环磷酰胺所致小鼠骨髓造血微环境损伤的影响

用环磷酰胺(Cy)连续3d腹腔注射(50mg/kg),造成小鼠的骨髓损伤模型.造模前3d开始给予药物,并与生理盐水组对照,连续7d.常规病理切片,镜下观察骨髓细胞的形态变化,并计算造血组织容量、脂肪组织容量、血窦容量和巨核细胞数;结果显示模型组与空白组有差异,而八珍汤和鸡血藤组的各种骨髓组织与模型组对比有明显恢复,从计算的骨髓各组织容量也可以得到相同的结果.     

造血重建小鼠骨髓中成纤维细胞的起源

选择Y染色体特异的性别决定基因(Sry)作为新的细胞遗传标志,采用PCR技术对小鼠骨髓细胞重建造血的性能和造血重建小鼠骨髓中成纤维细胞的起源进行研究.将正常雄鼠骨髓细胞输注给经致死剂量射线照射的受体雌性小鼠,PCR技术检测结果表明,在活存小鼠的骨髓、脾脏、胸腺和淋巴结中均具有供体起源的细胞.而正常雄鼠或5-氟尿嘧啶处理的雄鼠骨髓细胞输注给受体雌性小鼠后,造血重建小鼠骨髓中的成纤维细胞则为受体起源.由此可见,小鼠骨髓中的成纤维细胞与造血细胞具有不同的起源.     

Ex vivo expansions and transplantations of mouse bone marrow－derived hematopoietic stem／progenitor cells

To examine the effects of co-culture with bone marrow mesenchymal stem cells on expansion of hematopoietic tem/progenitor cells and the capacities of rapid neutrophil engraftment and hematopoietic reconstitution of the expanded ells, we expanded mononuclear cells (MNCs) and CD34^ /c-kit^ cells from mouse bone marrow and transplanted the expanded cells into the irradiated mice. MNCs were isolated from mouse bone marrow and CD34^ /c-kit^ cells were selected from MNCs by using MoFlo Cell Sorter. MNCs and CD34^ /c-kit^ cells were co-cultured with mouse bone marrow-derived mesenchymal stem cells (MSCs) under a two-step expansion. The expanded cells were then transplanted into sublethally irradiated BDF 1 mice. Results showed that the co-culture with MSCs resulted in expansions of median total nucleated cells, CD34^ cells, GM-CFC and HPP-CFC respectively by 10.8-, 4.8-, 65.9- and 38.8-fold for the mononuclear cell culture, and respectively by 76.1-, 2.9-, 71.7- and 51.8-fold for the CD34^ /c-kit^ cell culture. The expanded cells could rapidly engraft in the sublethally irradiated mice and reconstitute their hematopoiesis. Co-cultures with MSCs in conjunction with two-step expansion increased expansions of total nucleated cells, GM-CFC and HPP-CFC, which led us to conclude MSCs may create favorable environment for expansions of hematopoietic stem/progenitor cells. The availability of increased numbers of expanded ceils by the co-culture with MSCs may result in more rapid engraftment ofneutrophils following infusion to transplant recipients.     

PTEN maintains haematopoietic stem cells and acts in lineage choice and leukaemia prevention

Haematopoietic stem cells (HSCs) must achieve a balance between quiescence and activation that fulfils immediate demands for haematopoiesis without compromising long-term stem cell maintenance, yet little is known about the molecular events governing this balance. Phosphatase and tensin homologue (PTEN) functions as a negative regulator of the phosphatidylinositol-3-OH kinase (PI(3)K)-Akt pathway, which has crucial roles in cell proliferation, survival, differentiation and migration. Here we show that inactivation of PTEN in bone marrow HSCs causes their short-term expansion, but long-term decline, primarily owing to an enhanced level of HSC activation. PTEN-deficient HSCs engraft normally in recipient mice, but have an impaired ability to sustain haematopoietic reconstitution, reflecting the dysregulation of their cell cycle and decreased retention in the bone marrow niche. Mice with PTEN-mutant bone marrow also have an increased representation of myeloid and T-lymphoid lineages and develop myeloproliferative disorder (MPD). Notably, the cell populations that expand in PTEN mutants match those that become dominant in the acute myeloid/lymphoid leukaemia that develops in the later stages of MPD. Thus, PTEN has essential roles in restricting the activation of HSCs, in lineage fate determination, and in the prevention of leukaemogenesis.     

Stem-cell ageing modified by the cyclin-dependent kinase inhibitor p16INK4a

Stem-cell ageing is thought to contribute to altered tissue maintenance and repair. Older humans experience increased bone marrow failure and poorer haematologic tolerance of cytotoxic injury. Haematopoietic stem cells (HSCs) in older mice have decreased per-cell repopulating activity, self-renewal and homing abilities, myeloid skewing of differentiation, and increased apoptosis with stress. Here we report that the cyclin-dependent kinase inhibitor p16INK4a, the level of which was previously noted to increase in other cell types with age, accumulates and modulates specific age-associated HSC functions. Notably, in the absence of p16INK4a, HSC repopulating defects and apoptosis were mitigated, improving the stress tolerance of cells and the survival of animals in successive transplants, a stem-cell-autonomous tissue regeneration model. Inhibition of p16INK4a may ameliorate the physiological impact of ageing on stem cells and thereby improve injury repair in aged tissue.