巨核细胞系统生成的调控

巨核系是髓系造血的一部分,来自造血干细胞的巨核祖细胞,经增殖分化成为成熟的巨核细胞,最后生成血小板。巨核集落刺激因子主要作用于巨核祖细胞,使其增殖分化,并在体外增加巨核集落生成率。血小板生成索是肾脏等器官产生的糖蛋白,其血中含量受血小板数反馈调节,它的主要作用是促进巨核细胞DNA 合成、胞浆成熟和血小板生成。     

小分子化合物Me6TREN促进小鼠骨髓中造血干/祖细胞的增殖

目的:探讨小分子化合物Me6TREN对小鼠骨髓中造血干/祖细胞的增殖作用。方法:采用细胞计数、细胞集落形成能力检测、流式细胞术检测细胞表面标志等实验技术,观察Me6TREN对小鼠骨髓细胞的影响。结果:皮下注射Me6TREN 12 h后,Me6TREN组的集落形成能力、造血干/祖细胞表面标志lin-Sca-1+c-Kit+的比例均明显高于对照组;在体外分离培养的小鼠骨髓单个核细胞,4 d后Me6TREN组细胞的集落形成能力及造血干/祖细胞的增殖能力均高于对照组。结论:Me6TREN对小鼠骨髓造血干/祖细胞有一定的促增殖作用。     

远红外线对造血干/祖细胞生物学特性的影响

目的:了解远红外线对造血细胞增殖和定向分化的影响.方法:应用体外小鼠骨髓细胞培养技术,观察远红外线对拉-单祖细胞(CFU-GM),红系祖细胞(CFU-E)和成纤维细胞(CFU-F)增殖和分化的影响,并且利用免疫荧光纳米粒子(1FNB)检测靶细胞表面分化抗原(CD),进一步评佑远红外线对造血干/祖细胞的影响.结果:远红外线在37℃条件下照射时CFU-E、CFU-F和CFU-GM生成有促进作用,小鼠骨髓细胞表面标记有变化,靶细胞经2min照射后,增殖最旺盛.2min组与其它实验组(1min,5min,10min)数据经统计学处理,具有差异性(P均<0.05).结论:远红外线时小鼠骨髓造血干/祖细胞的增殖具有正调节作用并可诱导细胞表面标志改变.     

巨核细胞生成与调控的研究进展

巨核细胞由骨髓造血干细胞分化为巨核系祖细胞,再经过渡细胞的增殖分化,成熟后生成血小板。这一过程受到巨核细胞集落刺激因子和血小板生成素的特异性刺激,白细胞介素３,粒单系集落刺激因子,白细胞介素６和红细胞生成素等细胞因子的非特异性刺激,及血小板蛋白因子、β转化生长因子和干扰素的抑制,以及辅助骨髓细胞的调控。     

间充质干细胞体外调控骨髓造血前体细胞向单核系分化

研究间充质干细胞(MSC)能否在体外调控造血。体外分离培养人骨髓来源的MSC,RT-PCR检测其造血生长因子的表达,并以其为饲养层细胞,接种骨髓单个核细胞(MNC),观察生长情况,并通过形态学观察和流式细胞术分析,鉴定细胞来源和分化方向。结果显示,MSC构成性表达SCF、Flt3L和M-CSF,不表达C-CSF和GM-CSF,在骨髓MNC和MSC共培养体系中,大约2周左右可以看到大量的圆形细胞粘附在梭型MSC上生长,细胞胞体为圆形,胞浆较丰富,胞核为圆形、半月型或肾型,部分细胞呈典型的单核细胞形态,流式细胞术分析该类细胞表达CDl4,不表达CDl5、CD41、glycophorin A、CD5和CDl9。表明不需要添加外源性造血生长因子,间充质干细胞能在体外调控骨髓造血前体细胞向单核系分化,其定向分化可能与MSC分泌造血生长因子及MSC与造血细胞间相互作用有关。     

问充质干细胞体外调控骨髓造血前体细胞向单核系分化

研究间充质干细胞(MSC)能否在体外调控造血.体外分离培养人骨髓来源的MSC,RT-PCR检测其造血生长因子的表达,并以其为饲养层细胞,接种骨髓单个核细胞(MNC),观察生长情况,并通过形态学观察和流式细胞术分析,鉴定细胞来源和分化方向.结果显示,MSC构成性表达SCF、Flt3L和M-CSF,不表达G-CSF和GM-CSF,在骨髓MNC和MSC共培养体系中,大约2周左右可以看到大量的圆形细胞粘附在梭型MSC上生长,细胞胞体为圆形,胞浆较丰富,胞核为圆形、半月型或肾型,部分细胞呈典型的单核细胞形态,流式细胞术分析该类细胞表达CD14,不表达CD15、CD41、glycophorin A、CD5和CD19.表明不需要添加外源性造血生长因子,间充质干细胞能在体外调控骨髓造血前体细胞向单核系分化,其定向分化可能与MSC分泌造血生长因子及MSC与造血细胞间相互作用有关.     

巨核细胞生成调控相关细胞因子及其作用研究进展

造血干细胞分化生成巨核细胞是一个十分复杂的过程,包括造血干细胞动员及其向巨核系祖细胞分化,巨核系祖细胞增殖、分化生成未成熟巨核细胞,巨核细胞的成熟和血小板释放等过程。研究发现,造血干细胞动员及其向各系细胞分化的大部分过程都在一种称为"龛"的结构中进行,多种龛内信号分子参与了造血干细胞的动员和分化调控。该文对造血干细胞龛内参与造血干细胞动员和分化生成巨核细胞的几种重要细胞因子及其调控作用进行综述。     

IL-33转基因小鼠骨髓造血干／祖细胞向髓系细胞分化的能力增强

目的：利用IL-33转基因小鼠研究IL-33对造血干/祖细胞的增殖和分化影响。方法利用流式细胞仪分析IL-33转基因小鼠及同窝野生对照小鼠的外周血、脾脏、骨髓细胞的免疫表型及造血干细胞分化不同阶段细胞的数量变化;利用体外成克隆实验和细胞周期分析研究IL-33对于造血干细胞增殖能力的影响。结果与野生型小鼠相比,IL-33转基因小鼠B细胞和T细胞在外周血中都明显降低,粒细胞在外周血和骨髓中都有明显增加;IL-33转基因小鼠的骨髓造血干细胞和多能祖细胞数量减少,共同淋系祖细胞数量减少,共同髓系祖细胞和粒单系祖细胞数量增加;IL-33转基因小鼠的造血干细胞处于S-G2-M的细胞增多;体外单克隆实验发现IL-33转基因小鼠造血干细胞形成的集落数增加。结论 IL-33转基因小鼠造血干细胞增殖能力增强,更易向髓系细胞分化。     

UM171和SR1对不同来源造血干/祖细胞体外扩增的作用研究

目的探讨小分子化合物UM171和SR1对脐带血、供者动员外周血和淋巴瘤患者自体动员外周血3种来源的造血干/祖细胞(HSPCs)体外扩增的作用。方法将3种来源的CD34+细胞分别予以UM171、SR1干预后进行体外扩增培养,记为对照组、UM171组、SR1组和UM171+SR1组。通过细胞计数检测各组总有核细胞的数量,流式细胞术检测HSPCs的比例、各谱系分化细胞的比例和HSPCs上归巢相关因子CXCR4的表达水平。多组数据若满足方差齐性,采用单因素方差分析,组间两两比较采用LSD-t检验;若方差不齐,多组间比较以及两两比较均采用Kruskal-Wallis检验。结果与对照组比较,UM171和SR1均能促进3种来源HSPCs的比例升高,同时UM171能够增加3种来源HSPCs的扩增倍数。与对照组比较,UM171处理后脐带血来源的CD33^+(髓系)细胞的比例升高,CD41^+(巨核)细胞的比例降低;SR1处理后3种来源的CD3-CD56^+(自然杀伤)细胞的比例均升高。体外扩增48 h后各组HSPCs上CXCR4的表达较培养前增加。结论UM171能够有效扩增3种来源HSPCs的数量,促进脐带血来源HSPCs分化为髓系细胞并抑制其分化为巨核细胞。SR1能够促进3种来源HSPCs分化为自然杀伤细胞。体外扩增培养可以提高3种来源HSPCs上CXCR4的表达水平。     

骨髓基质细胞条件培养液联合TPO体外扩增巨核系细胞

目的：探讨骨髓成纤维细胞条件培养液（F-CM）和骨髓内皮细胞条件培养液（E-CM）分别联用TPO对巨核系细胞的体外扩增作用。方法：分别收集纯的F-CM和E-CM,观察它们分别与TPO联用后对体外扩增成熟巨核细胞和巨核系祖细胞的作用。结果：F-CM或E-CM与TPO联用后对巨核系成熟细胞的扩增作用明显优于F-CM或E-CM单用（P〈0．01或P〈0．05）;F-CM＋TPO的扩增效果明显优于E-CM＋TPo或SCF＋TPO＋IL-3＋IL-6的扩增效果（P〈0．01或P〈0．05）;F-CM或E-CM联合TPO后对祖细胞的扩增作用无明显改变（P〉0．05）。结论：F-CM与TPO联用后可显著提高它们对成熟巨核细胞体外扩增的效率,其作用优于SCF＋TPO＋IL-3＋IL-6;F-CM或E-CM与TPO联用后对巨核系祖细胞体外扩增作用与二者单用无显著差异。     

Replicative senescence of human bone marrow and umbilical cord derived mesenchymal stem cells and their differentiation to adipocytes and osteoblasts

Mesenchymal stem cells (MSC) which have self-renewal and multiple differentiation potential in vitro play important roles in regenerative medicine and tissue engineering. However, long-term culture in vitro leads to senescence which results in the growth arrest and reduction of differentiation. In this study, MSC derived from human bone-marrow (BM-MSC) and umbilical cord (UC-MSC) were cultured in vitro lasted to senescence. Senescence and apoptosis detection showed that the senescent cells increased significantly but the increase of apoptosis was not significant in the long term culture. Senescence related genes p16, p21 and p53 increased gradually in BM-MSC. However, p16 and p53 reduced and then increased but with the gradual increase of p21 in UC-MSC. Adipogenic differentiation decreased whereas the propensity for osteogenic differentiation increased in senescent MSC. Real time RT-PCR demonstrated that both C/EBPα and PPARγ decreased in senescent BM-MSC. However, in UC-MSC, PPARγ decreased but C/EBPα increased in late phase compared to early phase. The study demonstrated p21 was important in the senescence of BM-MSC and UC-MSC. C/EBPα and PPARγ could regulate the balance of adipogenic differentiation in BM-MSC but only PPARγ not C/EBPα was involved in the adipogenic differentiation in UC-MSC.     

Umbilical cord fibroblasts: Could they be considered as mesenchymal stem cells?

In cell therapy protocols, many tissues were proposed as a source of mesenchymal stem cells (MSC) isolation. So far, bone marrow (BM) has been presented as the main source of MSC despite the invasive isolation procedure related to this source. During the last years, the umbilical cord (UC) matrix was cited in different studies as a reliable source from which long term ex vivo proliferating fibroblasts were isolated but with contradictory data about their immunophenotype, gene expression profile, and differentiation potential. Hence, an interesting question emerged: Are cells isolated from cord matrix (UC-MSC) different from other MSCs? In this review, we will summarize different studies that isolated and characterized UC-MSC. Considering BM-MSC as gold standard, we will discuss if UC-MSC fulfill different criteria that define MSC, and what remain to be done in this issue.     

Mesenchymal stem cells promote a primitive phenotype CD34+c-kit+ in human cord blood-derived hematopoietic stem cells during ex vivo expansion

The purpose of this study was to evaluate the influence of bone marrow-mesenchymal stem cells (BM-MSC) and exogenously added cytokines on the proliferation, primitive cell subpopulation maintenance (including the c-kit+ marker) and clonogenic capacity of hematopoietic stem cells (HSC). BM-MSC were collected from volunteer donors, isolated and characterized. Umbilical cord blood (UCB) samples were collected from healthy full-term deliveries. UCB-CD34+ cells were cultured in the presence or absence of BM-MSC and/or cytokines for 3 and 7 days. CD34+ cell proliferation was evaluated using the CSFE method and cell phenotype was determined by CD34, c-kit, CD33, CD38, HLA-DR, cyCD22 and cyCD3 detection. Cell clonogenic ability was also assessed. Exogenously added SCF, TPO and FLT3L increasedCD34+ cell proliferation in the presence or absence of BM-MSC, but with concomitant cell differentiation. Without any added cytokines, BM-MSC are able to increase the percentage of primitive progenitors as evaluated by c-kit expression and CFU-GEMM increase. Interestingly, this latter effect was dependent on both cell-cell interactions and secreted factors. A 7-day co-culture period will be optimal for obtaining an increased primitive HSC level. Including c-kit as a marker for primitive phenotype evaluation has shown the relevance of BM-MSC and their secreted factors on UCB-HSC stemness function. This effect could be dissociated from that of the addition of exogenous cytokines, which induced cellular differentiation instead.     

HLA-G参与骨髓间充质干细胞的抑制作用机制探讨

目的：探讨人骨髓间充质干细胞（MSC）在活体肾移植供受者间的混合淋巴细胞培养（MLR）中的作用机制,证明人白细胞抗原（HLA）-Ⅰ类分子HLA-G参与了MSC的免疫调节作用。方法：从人骨髓中分离培养MSC,采用形态学观察及流式细胞术分析鉴定后,加入活体肾移植供受者间的MLR,观察MSC的HLA-G表达及对T细胞增殖的影响,淋巴细胞增殖实验采用MTT法。结果：MSC细胞表面和胞浆内均表达HLA-G,流式细胞术分析细胞表面HLA-G平均表达率为37.3%,胞浆内HLA-G平均表达率为65.1%,ELISA法检测细胞培养上清中可溶性HLA-G含量为18.9ng/mL。将MSC和培养上清液加入活体肾移植供受者间的MLR体系中,均使得T细胞抑制率增高;而加入HLA-G特异性抗体,MSC的抑制率降低。结论：MSC表面和胞浆内均有HLA-G表达,在其培养上清中检测到由MSC分泌的可溶性HLA-G5;MSC表达和分泌的HLA-G是其发挥抑制功能的关键因素之一。为MSC在预防器官移植术后排斥反应的临床应用提供了理论依据。     

生长因子TGF-β1和bFGF促兔骨髓间质干细胞向韧带样细胞分化的实验研究

摘要目的：采用生长因子TGF-β1和bFGF诱导体外培养的兔骨髓间质干细胞（MSCs）,转化为韧带样细胞,并研究此种韧带样细胞的生物特性。方法：自幼兔四肢骨抽取骨髓分离纯化MSCs并培养、增殖;采用特定浓度TGF-β1（10ng／ml）和bFGF（25ng／mL）对MSCs进行诱导分化,观察生长因子对MSCs生长、形态的影响,使用MTT法绘制细胞生长曲线,使用天狼腥红染色法定量对比MSCs分泌胶原蛋白量。单纯培养和单一因子诱导组作为对照。结果：TGF-β1和bFGF联合使用组,细胞形态优于空白组及单一因子组,细胞增殖率、胶原分泌量也均高于对照组。结论：联合使用生长因子TGF-β1和bFGF刺激兔MSCs,能够促使兔MSCs定向转化为韧带样细胞,对组织工程前交叉韧带的构建具有积极意义。     

Long-term survival and characterisation of human umbilical cord-derived mesenchymal stem cells on dermal equivalents

During early embryogenesis, mesenchymal cells arise from the primitive epithelium and can revert to an epithelial phenotype by passing through mesenchymal-to-epithelial transition (MET). Mesenchymal stem cells (MSC) of the Wharton's Jelly of the umbilical cord (UC-MSC) express pluripotency markers underlining their primitive developmental state. As mesenchymal stem cells from bone marrow (BM-MSC) possess a strong propensity to ameliorate mesenchymal tissue damage, UC-MSC might also be able to differentiate into cells apart from the mesoderm, allowing replacement of ectodermal and mesodermal tissues.     

脐带间充质干细胞移植对慢性试验性肝损伤的治疗作用

目的观察脐带间充质干细胞（UC-MSC）对慢性实验性肝损伤的治疗作用并探讨其分子生物学机理。方法 50只7周龄的NOD/SCID小鼠注射四氯化碳（CCL4）制备慢性肝损伤模型后,应用随机数字表的方法随机将实验小鼠随机分成2组：模型组（25只）和UC-MSC移植组（25只）。UC-MSC移植组通过尾静脉注射移植1×106 UC-MSC,模型组注射同样体积的PBS。分别于移植后1、2、3和4周收集肝组织,应用免疫组织化学,RT-PCR和Western blot的方法分析细胞移植前后肝组织的病理生理学特征的变化。采用t检验和方差分析进行统计学分析。结果 UC-MSC移植治疗后肝组织表达人肝细胞特异性AFP,Alb,和内皮细胞特异性CD31,Flk-1。细胞移植4周后v WF标记的血管密度明显增加,同时伴有部分的肝功能改善,谷丙转氨酶（ALT）水平从（55.71±11.33）U/L减至（36.75±12.80）U/L（P〈0.05）。此外,本研究结果表明UC-MSC分泌几种重要的生长因子HGF,FGF-2,VEGF,和VEGF受体通过旁分泌的途径发挥肝组织修复的功能。结论在CCL4诱导的慢性肝损伤模型肝组织,人UC-MSC可以分化成肝细胞样细胞和内皮细胞样细胞,同时旁分泌多种细胞生长因子修复损伤的肝细胞,并伴有肝功能的改善。认为UCMSC移植或许成为将来肝脏损伤疾病一个重要的治疗选择。     

内皮和造血系统特异性敲除Rictor基因对胎肝造血的影响

目的:研究Rictor基因对胚胎发育过程中胎肝造血的影响。方法:利用Cre-LoxP基因敲除系统,特异性在小鼠内皮(VEC-Cre)和造血(Vav1-Cre)系统敲除Rictor基因;通过流式细胞术分析特异敲除Rictor基因后小鼠胚胎第15 d胎肝中的各系细胞比例的变化,并进一步分析造血干细胞的变化。结果:利用VEC-Cre和Vav1-Cre小鼠敲除Rictor基因后,胎肝中各系细胞比例均有所减少,B细胞比例的减少较为明显,造血干细胞比例也明显减少。结论:Rictor基因敲除损害胎肝组织中造血干细胞的产生和各系细胞的分化。     

Tumor microenvironment: Bone marrow-mesenchymal stem cells as key players

Tumor progression is a multistep phenomenon in which tumor-associated stromal cells perform an intricate cross-talk with tumor cells, supplying appropriate signals that may promote tumor aggressiveness. Among several cell types that constitute the tumor stroma, the discovery that bone marrow-derived mesenchymal stem cells (BM-MSC) have a strong tropism for tumors has achieved notoriety in recent years. Not only are the BM-MSC recruited, but they can also engraft at tumor sites and transdifferentiate into cells such as activated fibroblasts, perivascular cells and macrophages, which will perform a key role in tumor progression. Whether the BM-MSC and their derived cells promote or suppress the tumor progression is a controversial issue. Recently, it has been proposed that proinflammatory stimuli can be decisive in driving BM-MSC polarization into cells with either tumor-supportive or tumor-repressive phenotypes (MSC1/MSC2). These considerations are extremely important both to an understanding of tumor biology and to the putative use of BM-MSC as “magic bullets” against tumors. In this review, we discuss the role of BM-MSC in many steps in tumor progression, focusing on the factors that attract BM-MSC to tumors, BM-MSC differentiation ability, the role of BM-MSC in tumor support or inhibition, the immunomodulation promoted by BM-MSC and metastatic niche formation by these cells.     

人脐带间充质干细胞对CCl4诱导肝纤维化的治疗作用研究

目的：探讨人脐带间充质干细胞（UC-MSC）治疗肝纤维化的可行性。方法：采用CCL腹腔注射小鼠制备肝纤维化模型,分别于第4、10周给予尾静脉注射移植UC-MSC进行治疗,检测治疗后血清学指标的改变和病理变化,观察UC-MSC对肝纤维化的疗效。结果：4周和10周进行治疗均可改善肝功能,减轻纤维化程度。结论：UC-MSC对CCl4诱导的肝纤维化具有一定的疗效。