晚期糖基化终产物通过氧化应激引起人骨髓间充质干细胞凋亡

目的观察不同剂量晚期糖基化牛血清白蛋白(AGE-BSA)对体外分离培养的人骨髓间充质干细胞增殖、凋亡及氧化应激的影响,为临床上提高干细胞移植治疗糖尿病心肌病后供体干细胞的存活率提供新的依据。方法采用全骨髓法从人的骨髓标本中分离培养骨髓间充质干细胞,以含10%FCS的L-DMEM培养细胞,0.25%的胰酶消化后按1∶2比例传代接种培养,对P3代细胞应用流式细胞仪检测细胞表面标志CD44、CD105和CD34。在骨髓间充质干细胞中加入不同浓度的AGE-BSA,作用24 h后加入CCK-8溶液,37℃、5%CO2培养箱培养1 h,用酶标仪在450 nm处测定吸光度值。采用Annexin V/PI双染法进行染色,避光作用20 min后,将细胞置于流式细胞仪上检测细胞凋亡百分率。同时对细胞内活性氧水平进行测定,并且测定细胞内丙二醛的含量和超氧化物歧化酶(SOD)活性。结果传代后的骨髓间充质干细胞呈鱼群样或漩涡状排列,细胞为长梭形,贴壁紧密,形态较为一致。细胞表面标志CD105(间充质干细胞相对特异性标志)及CD44(黏附分子,基质细胞表达)呈阳性表达,阳性率分别达98.9%和97.8%;CD34(造血干细胞/祖细胞及内...     

microRNA-223对糖基化终产物诱导人脂肪间充质干细胞凋亡和氧化应激影响的体外研究

目的观察microRNA-223(miR-223)对糖基化终产物(AGE)诱导人脂肪间充质干细胞(h ADSC)凋亡和氧化应激的影响。方法采用酶消化法分离培养h ADSC,并应用流式细胞术对表面抗原CD14、CD34、CD45、CD90、CD105和人类白细胞抗原DR(HLA-DR)进行检测。将h ADSC分为牛血清白蛋白(BSA)对照组、AGE修饰的牛血清白蛋白(AGE-BSA)作用组、miR-223模拟物转染组、miR-223模拟物转染+AGE-BSA组、miR-223抑制物转染组和miR-223抑制物转染+AGE-BSA组。应用CCK-8法和TUNEL染色检测各组细胞存活率和凋亡率,Western blot检测Cleaved Caspase3蛋白表达水平,应用双氯荧光素(DCFH-DA)试剂盒检测各组细胞活性氧(ROS)含量。结果流式细胞术检测结果表明,原代培养的h ADSC高表达CD14、CD90和CD105,不表达CD34、CD45和HLADR。CCK-8法、TUNEL染色、Western blot和DCFH-DA法检测结果表明,与BSA对照组相比,AGE-BSA作用组h ADSC凋亡率、miR-223表达水平、Cleaved Caspase3蛋白表达水平、ROS生成显著升高,而细胞存活率下降(P0.05);与AGE-BSA作用组相比,miR-223模拟物转染能够进一步上调AGE-BSA引起的h ADSC凋亡率、Cleaved Caspase3蛋白表达水平和ROS生成增加,下调AGE-BSA引起的h ADSC存活率减少(P0.05);与AGE-BSA作用组相比,miR-223抑制物转染能够抑制h ADSC凋亡率、Cleaved Caspase3蛋白表达水平和ROS生成增加,拮抗AGEBSA引起的h ADSC存活率减少(P0.05)。结论 miR-223高表达能够促进AGE-BSA引起的h ADSC细胞凋亡和ROS生成,其可能作为调控h ADSC促进糖尿病创伤愈合的新靶点。     

体外培养成人脂肪间充质干细胞及向平滑肌细胞诱导分化

目的 体外培养成人脂肪间充质干细胞,并应用转化生长因子β将脂肪间充质干细胞诱导分化为平滑肌细胞.方法 采用酶消化法和贴壁培养法分离培养脂肪间充质干细胞,流式细胞仪对第3代和第5代细胞进行表面抗原检测,对第5代细胞进行转化生长因子β诱导,于诱导后第10天进行免疫化学鉴定.结果 体外培养的脂肪间充质干细胞呈扁平的长梭形,细胞形态均一,传代稳定.干细胞相关标志CD29和CD44表达阳性,造血干细胞相关标志CD34随传代次数的增加由弱阳性逐渐转为阴性,内皮细胞相关标志CD31表达阴性.流式细胞仪检测结果 发现脂肪间充质干细胞中G0/G1、S和G2/M期的细胞分别占90.14%、3.77%和6.09%.转化生长因子β定向诱导后倒置显微镜下观察细胞呈"峰"、"谷"样形态,免疫荧光化学检测发现诱导组细胞α平滑肌肌动蛋白表达阳性.结论 成人脂肪组织中含有间充质干细胞,且可在转化生长因子β诱导后分化为平滑肌细胞.     

雌激素对过氧化氢诱导的大鼠骨髓间充质干细胞凋亡的影响

目的探讨雌激素抑制过氧化氢（H2O2）诱导的大鼠骨髓间充质干细胞凋亡的作用及机制,为临床骨髓间充质干细胞治疗冠心病有较高的干细胞存活率提供理论依据。方法流式细胞仪检测干细胞免疫表型;MTY法检测细胞活性;Rhodamine-123染色检测线粒体膜电位;RT-PCR检测Caspase-9的表达。结果H2O2促进干细胞凋亡,而雌激素可提高干细胞的活性,降低细胞线粒体膜电位,抑制Caspase-9的表达进而抑制细胞凋亡。结论雌激素可有效抑制氧化应激诱导的大鼠骨髓间充质干细胞的凋亡。     

小鼠骨髓间充质干细胞的分离、培养新方法

目的探讨一种新的小鼠骨髓间充质干细胞的分离、培养方法。方法分离小鼠3 d乳鼠双后肢,剔除肌肉筋膜组织,剪碎后接种于含10%胎牛血清的α-MEM中,观察细胞形态学变化,采用CCK8检测细胞增殖能力,绘制细胞生长曲线,采用流式细胞技术鉴定细胞表面抗原,并进行多向分化潜能鉴定。结果原代分离培养的小鼠骨髓间充质干细胞呈长梭形,从骨片周围爬出,传代后,细胞形态一致,生长良好;绘制的细胞生长曲线呈"S"型,流式细胞表型鉴定结果显示,培养的细胞高表达CD90、CD29,低表达CD11b、CD45,成脂油红O染色和成骨茜素红染色均呈阳性。结论采用小鼠3 d乳鼠骨片法能够成功培养出骨髓间充质干细胞,骨髓间充质干细胞可作为肝脏组织工程的种子细胞。     

人骨髓间充质干细胞体外长期传代培养及恶性转化趋势实验研究

目的 探讨人骨髓间充质干细胞体外长期传代培养、扩增及其生物学特性,观察其恶性转化趋势的可能性.方法 采用密度梯度离心差速贴壁法对人骨髓来源的间充质干细胞进行分离纯化,并进行体外长期传代,观察细胞形态及生长方式;鉴定细胞分化能力;相关癌标志P53、Ki67的表达与成瘤性检测.结果 经过长期体外培养的人间充质干细胞,至36代时,细胞逐渐老化;成骨分化诱导能力丧失;相关癌标志表达阴性;无成瘤性.结论 人骨髓间充质干细胞在体外可以有限传代,无显著恶性转化趋势.     

成人骨髓间充质干细胞与造血细胞的发育级系的关系

目的：探讨骨髓间充质干细胞在细胞发育级系中与造血细胞的关系。方法：分离培养成年慢性髓性白血病患者骨髓的间充质干细胞，用FCM鉴定其纯度。应用RT－PCR检测细胞是否携带白血病特异性基因，结合流式细胞术观察多种造血调控因子刺激后是否具有造血细胞的表面分子标志及基因标志，结果：骨髓间充质干细胞不表达造血细胞特异性白血病基因，细胞因子作用2周后未出现血细胞表型，CD34及CD45均为阴性，结论：造血干细胞与间充质干细胞之间似乎不存在交叉分化现象，为解释其他细胞间的相互转化提出了新的线索。     

人脐带间充质干细胞生物学特性及向类肝细胞的分化

目的: 研究脐带间充质干细胞(umbilical cord-mesenchymal stem cells, UC-MSCs)生物学的特性及向肝细胞分化的可能性.方法:从脐带中分离间充质干细胞, 体外行传代培养, 检测脐带间充质干细胞表面免疫标志、细胞周期和生长活性等, 利用肝细胞生长因子、成纤维生长因子4和抑瘤素等细胞因子诱导脐带间充质干细胞向肝细胞分化, 用免疫细胞方法对诱导和未诱导的细胞进行免疫学检测, 糖原染色进行功能鉴定.结果: 从人脐带中可分离到贴壁生长的间充质干细胞, 细胞形态类似成纤维细胞,可在体外进行长期稳定培养; CD29、CD105和Vimentin表达阳性, 基本不表达CD34、CD31, 经加入细胞因子可成功将间充质干细胞向肝细胞诱导分化, 分化的细胞表达肝细胞表面标志物ALB、AFP、CK18和CK19, 糖原染色呈现阳性.结论:人脐带中可成功分离到间充质干细胞, 细胞可实现体外长期培养, 表达脐带间充质干细胞的表面标志, 在体外脐带间充质干细胞诱导分化为肝细胞, 有望成为细胞替代治疗的理想来源之一.     

小鼠骨髓基质干细胞的鉴定及体外诱导分化为肝细胞的可行性

目的:分离、鉴定小鼠骨髓基质干细胞(MSCs)并探讨在体外多种细胞因子的诱导下分化为肝细胞的可行性.方法:获取小鼠骨髓干细胞,进行体外贴壁培养、纯化,观察不同传代次数细胞形态特点.流式细胞法检测不同传代细胞的表面标志物CD45和CD90.分离后的MSCs再经含有HGF,FGF-4,EGF三种细胞因子的诱导体系继续培养21 d,分别以半定量逆转录聚合酶链反应(RT-PCR)和Western blot方法检测诱导后细胞的白蛋白(ALB)、细胞角化蛋白18(Cg18)、以及甲胎蛋白(AFP)在基因和蛋白水平的表达.结果:培养的骨髓干细胞随传代次数增多细胞形态趋向为长梭形.传代到第5代,基质干细胞的表面标志CD90阳性细胞从原代的25.42%增加到93.47%,造血干细胞的表面标志CD45表达阳性细胞从原代的86.49%降低到2.77%.通过RT-PCR可检测出诱导第7天细胞表达AFP mRNA,ALB mRNA及CK18 mRNA;通过Western blot可检测出诱导第21天的细胞表达ALB和CK18.结论:小鼠MSCs可以在体外被有效地分离纯化,可以被诱导为表达肝细胞表面标志的肝细胞样细胞.     

巴马香猪骨髓间充质干细胞的分离扩增及初步鉴定

目的 建立巴马香猪骨髓间充质干细胞(mesenchymal stem cells,MSCs)分离、培养、扩增的方法,并进行鉴定.方法 采用梯度离心法分离并结合贴壁筛选法传代纯化培养猪的MSCs;采用倒置相差显微镜观察MSCs的形态学特征;流式细胞仪检测第3代细胞表面标志抗原CD71、CD34的表达率.结果 原代培养的MSCs于6 h后贴壁,贴壁细胞呈集群生长趋势.培养7～9 d后可见细胞融合,14～21 d达到95%融合.第3代细胞表面标记物CD71阳性率为95%,CD34阳性率为0%.结论 采用全骨髓梯度离心法分离并结合贴壁筛选法能够成功分离和培养巴马香猪的MSCs,在第3代可获得高纯度MSCs.     

成人骨髓间充质干细胞体外诱导分化为神经元样细胞的研究

目的 研究成人骨髓间充质干细胞(hMSC)体外定向诱导可否分化为神经元样细胞。方法 Percoll分离液离心分离hMSC，体外扩增，采用两种方法：①含碱性成纤维细胞生长因子(bFGF)预诱导24小时，甲氧酚(BHA)和二甲亚枫(DMSO)联合诱导6小时；②2-巯基乙醇(2-ME)预诱导24小时，BHA和DMSO诱导6小时。免疫组化检测神经元样细胞表达神经元烯醇化酶(NSE)、神经丝蛋白(NF)、胶质纤维酸性蛋白(GFAP)。结果 hMSC在体外扩增传至5代后，流式细胞仪显示hMSC表面抗原CD29、CD44、CD90表达阳性率分别为99．5％，97．8％，98．8％。采用两种方法诱导hMSC后，胞体收缩，突起伸出，较密的部分神经元拉成网状；免疫组化显示诱导的神经元样细胞能特异性表达NSE、NF，不表达GFAP。结论 成人骨髓hMSC在体外可以分化为神经元样细胞。     

Adipogenic effect of alcohol on human bone marrow-derived mesenchymal stem cells

BACKGROUND: In addition to a decrease in bone mass in alcoholics their osteopenic skeletons show an increase in bone marrow adiposity. Human bone marrow mesenchymal stem cells (hMSC) in vivo differentiate into several phenotypes including osteogenic and adipogenic cells, both of which remain as resident populations of bone marrow. In vitro, the lineage commitment and differentiation of hMSC toward the adipogenic pathway can be promoted by alcohol. METHODS: Human male and female mesenchymal stem cells from joint replacement surgery were cultured. Cells were grouped as: 1) Control (no additions to the culture medium), 2) EtOH (50 mm alcohol added to the culture medium), 3) OS (osteogenic inducers added to the culture medium), and 4) OS + EtOH (osteogenic inducers and 50 mm alcohol added to the culture medium). Cultures stained with Nile Red confirmed the development of differentiated adipocytes. Population analysis was performed using fluorescence-activated cell sorting. Gene expression of early, middle, late, and terminal differentiation stage markers (PPAR)gamma2, lipoprotein lipase, adipsin, leptin, and adipocyte P2 (aP2)] was studied by Northern hybridization, and protein synthesis of aP2 was determined by Western analysis. RESULTS: Nile red staining confirmed increased adipocyte development 10 days after the onset of treatment with 50 mm alcohol and osteogenic induction. By day 21 the number of adipocytes increased to 13.6% of the total population. Alcohol up-regulated the gene expression of PPARgamma2 whereas no up-regulation was observed for the other genes. Protein production of aP2 was significantly increased in hMSC cells by culture in the presence of alcohol. CONCLUSIONS: The data suggest that alcohol's adipogenic effect on cultured hMSC is through up-regulation of PPARgamma2 at the point of lineage commitment as well as through enhancement of lipid transport and storage through increased aP2 synthesis. The alcohol-induced expression and synthesis changes account for the increased Nile red staining of cultured hMSC.     

Human mesenchymal stem cells favour healing of the cutaneous radiation syndrome in a xenogenic transplant model

It has been suggested that human mesenchymal stem cells (hMSC) could be used to repair numerous injured tissues. We have studied the potential use of hMSC to limit radiation-induced skin lesions. Immunodeficient NOD/SCID mice were locally irradiated to the leg (30 Gy, dose rate 2.7 Gy/min) using a ⁶⁰Co source to induce a severe skin lesion. Cultured bone marrow hMSC were delivered intravenously to the mice. The irradiated skin samples were studied for the presence of the human cells, the severity of the lesions and the healing process. Macroscopic analysis and histology results showed that the lesions were evolving to a less severe degree of radiation dermatitis after hMSC transplant when compared to irradiated non-transplanted controls. Clinical scores for the studied skin parameters of treated mice were significantly improved. A faster healing was observed when compared to untreated mouse. Immunohistology and polymerase chain reaction analysis provided evidence that the human cells were found in the irradiated area. These results suggest a possible use of hMSC for the treatment of the early phase of the cutaneous radiation syndrome. A successful transplant of stem cells and subsequent reduction in radiation-induced complication may open the road to completely new strategies in cutaneous radiation syndrome therapy.     

Engineering of a functional bone organ through endochondral ossification

Embryonic development, lengthening, and repair of most bones proceed by endochondral ossification, namely through formation of a cartilage intermediate. It was previously demonstrated that adult human bone marrow-derived mesenchymal stem/stromal cells (hMSCs) can execute an endochondral program and ectopically generate mature bone. Here we hypothesized that hMSCs pushed through endochondral ossification can engineer a scaled-up ossicle with features of a “bone organ,” including physiologically remodeled bone, mature vasculature, and a fully functional hematopoietic compartment. Engineered hypertrophic cartilage required IL-1β to be efficiently remodeled into bone and bone marrow upon subcutaneous implantation. This model allowed distinguishing, by analogy with bone development and repair, an outer, cortical-like perichondral bone, generated mainly by host cells and laid over a premineralized area, and an inner, trabecular-like, endochondral bone, generated mainly by the human cells and formed over the cartilaginous template. Hypertrophic cartilage remodeling was paralleled by ingrowth of blood vessels, displaying sinusoid-like structures and stabilized by pericytic cells. Marrow cavities of the ossicles contained phenotypically defined hematopoietic stem cells and progenitor cells at similar frequencies as native bones, and marrow from ossicles reconstituted multilineage long-term hematopoiesis in lethally irradiated mice. This study, by invoking a “developmental engineering” paradigm, reports the generation by appropriately instructed hMSC of an ectopic “bone organ” with a size, structure, and functionality comparable to native bones. The work thus provides a model useful for fundamental and translational studies of bone morphogenesis and regeneration, as well as for the controlled manipulation of hematopoietic stem cell niches in physiology and pathology.     

Self-renewal and differentiation capacity of bone marrow and fetal liver stem cells

S ummary . An operational definition of the pluripotent stem cell (CFC-S) requires that it have both the capacity for self-renewal and the potential for differentiation into more than one class of formed blood elements. Because the CFC-S compartment is heterogeneous, younger stem cells would be expected to be less committed to differentiation and have a higher rate of self-renewal; whereas, older stem cells would be more committed to differentiation and have a lower rate of self-renewal. In this study, the self-renewal capacity versus the differentiation potential of adult bone marrow and fetal liver stem cells were compared. The self-renewal potential was estimated by determining the number of CFC-S which develop during growth in the spleen or femur of primary recipients. The differentiation potential was estimated by determining the total number of nucleated cells or committed progenitor cells (GM-CFU-C and BFU-E) which develop during growth in the spleen or femur of primary recipients. In order to circumvent possible differences in self-renewal or differentiation pressures due to the presence of differing numbers of CFC-S, an equivalent number of bone marrow and fetal liver CFC-S were allowed to seed the spleen and femur. While both adult bone marrow and fetal liver stem cells showed an extensive capacity for self-renewal, fetal liver CFC-S displayed a greater potential for self-renewal in both the spleen and femur and at all growth intervals measured when compared to adult bone marrow CFC-S. In contrast, no differences were seen in the number of nucleated cells or committed stem cells found per CFC-S when comparing adult bone marrow and fetal liver stem cells.     

Rosiglitazone induces decreases in bone mass and strength that are reminiscent of aged bone

Peroxisome proliferator-activated receptor-gamma (PPARgamma) regulates both glucose metabolism and bone mass. Recent evidence suggests that the therapeutic modulation of PPARgamma activity with antidiabetic thiazolidinediones elicits unwanted effects on bone. In this study, the effects of rosiglitazone on the skeleton of growing (1 month), adult (6 month), and aged (24 month) C57BL/6 mice were determined. Aging was identified as a confounding factor for rosiglitazone-induced bone loss that correlated with the increased expression of PPARgamma in bone marrow mesenchymal stem cells. The bone of young growing mice was least affected, although a significant decrease in bone formation rate was noted. In both adult and aged animals, bone volume was significantly decreased by rosiglitazone. In adult animals, bone loss correlated with attenuated bone formation, whereas in aged animals, bone loss was associated with increased osteoclastogenesis, mediated by increased receptor activator of nuclear factor-kappaB ligand (RANKL) expression. PPARgamma activation led to changes in marrow structure and function such as a decrease in osteoblast number, an increase in marrow fat cells, an increase in osteoclast number, and a loss of the multipotential character of marrow mesenchymal stem cells. In conclusion, rosiglitazone induces changes in bone reminiscent of aged bone and appears to induce bone loss by altering the phenotype of marrow mesenchymal stem cells.     

PTH and stem cells

At least 2 different types of cells, hematopoietic and mesenchymal, are present in the adult bone marrow, in addition to endothelial cells. Hematopoietic and mesenchymal cells are believed to originate from hematopoietic stem cells (HSC) and mesenchymal stem cells (MSC), respectively. The bone marrow stroma, a cellular microenvironment that supports HSC, is composed of non-hematopoietic cells and contains MSC. A unique expansion of the bone marrow stroma, also known as marrow fibrosis, is the hallmark of a variety of disorders including hyperparathyroidism and fibrous dysplasia. PTH is the first bone anabolic agent approved by US Food and Drug Administration for the treatment of osteoporosis. Recent studies have suggested that PTH treatment may affect the number of hematopoietic stem cells in the bone marrow and their mobilization into the bloodstream. In addition, cells with classical features of mesenchymal stem cells/progenitors have been shown to express receptors for PTH, and to increase in number and undergo redistribution in the adult bone marrow upon PTH treatment. In this review, we will summarize the up-to-date knowledge on PTH and its relation to stem cells. We will also discuss the contribution of different cell types to the development of marrow fibrosis and the involvement of PTH signaling in this pathology.     

Aged Human Bone Marrow Stromal Cells Maintaining Bone Forming Capacity in vivo Evaluated Using an Improved Method of Visualization

Age-related decreased osteoblast function is a well-known but poorly understood phenomenon. Previous studies that examined the effects of donor age on osteoblast functions employed in vitro assays that may not reflect the true osteoblast capacity for bone formation. Thus, we have developed an in vivo assay for quantifying the bone forming capacity (BFC) and we compared the BFC of osteoblastic cells obtained from young and old donors. Osteoblasts were obtained from human bone marrow stromal cell cultures and implanted subcutaneously in immuno-deficient mice (NOD/LtSz- Prkdc(scid)). After 8 weeks, the implants were removed and embedded un-decalcified in methyl methacrylate (MMA). Sections were stained histochemically with Goldner's Trichrome stain and immuno-histochemically using human-specific antibodies against known osteogenic markers. Implanted human marrow stromal cells (hMSC) were able to form bone in vivo. The donor origin of bone was verified using several human-specific antibodies. Dose-response experiments demonstrated that 5 x 10(5) hMSC per implant gave the maximal bone formation after 8 weeks. No difference in BFC was observed between cells obtained from young (24-30 years old; mean age 27 +/- 2 years, n = 5) and old (71-81 years old; mean age 75 +/- 4 years, n = 5) donors. Our study demonstrates that the capacity of hMSC to form bone in vivo is maintained with age and suggests that the observed senescence-associated decrease in bone formation is due to a defect in the bone microenvironment, the nature of which remains to be determined.     

Bone marrow stem cells and the liver: Are they relevant?

The contribution of bone marrow stem cell responses to liver homeostasis, injury and malignancy is discussed in this review. Pluripotent stem cells or their more committed progenitor progeny are essential to tissue development, regeneration and repair and are widely implicated in the pathogenesis of malignancy. Stem cell responses to injury are the focus of intense research efforts in the hope of future therapeutic manipulation. Stem cells occur within tissues, such as the liver, or arise from extrahepatic sites, in particular, the bone marrow. As the largest reservoir of stem cells in the adult, the bone marrow has been implicated in the stem cell response associated with liver injury. However, in liver injury, the relative contribution of bone marrow stem cells compared to intrahepatic progenitor responses is poorly characterized. Intrahepatic progenitor responses have been recently reviewed elsewhere. In this review, we have summarized liver-specific extrahepatic stem cell responses originating from the bone marrow. The physiological relevance of bone marrow stem cell responses to adult liver homeostasis, injury and malignancy is discussed with emphasis on mechanisms of bone marrow stem cell recruitment to sites of liver injury and its contribution to intrahepatic malignancy.     

Stromal stem cells (CFU-f) in yolk sac, liver, spleen and bone marrow of pre- and postnatal mice

Our results demonstrate that in yolk sac, liver, spleen and femoral bone marrow of mice at ages ranging between 11 d of gestation and adult life, important changes in the stromal stem cell population (CFU-f assay) occur which are correlated with haemopoiesis. In the liver, spleen and bone marrow, high numbers of CFU-f precede high haemopoietic stem cell values. As haemopoiesis starts in the spleen, CFU-f numbers in fetal liver are low. Similarly, CFU-f numbers decrease in the spleen as bone marrow haemopoiesis starts. This suggests the existence of a migration stream of stromal stem cells. In spleen and bone marrow, CFU-f numbers decrease towards adult life as these organs maintain a stable haemopoietic activity.