Neural cell adhesion molecule contributes to hemopoiesis-supporting capacity of stromal cell lines

To clarify mechanisms underlying cell-to-cell interactions between hemopoietic stem cells (HSCs) and stromal cells, we established a stromal cell line (FMS/PA6-P) from day-16 fetal bone marrow (BM) adherent cells using an anti-PA6 monoclonal antibody (mAb) specific for BM stromal cells. Importantly, this FMS/PA6-P cell line, showing homogenous fibroblastic morphology, is absent from hematolymphoid and endothelial lineage markers and maintains a high level of expression of PA6 molecule, recognized by the anti-PA6 mAb, for approximately 20 passages. Further, the cell line expressing a high level of PA6 molecule has a better hemopoiesis-supporting capacity in vitro than other stromal cell lines such as PA6 and MS-5. In fact, the PA6 molecule is closely related to the hemopoiesis-supporting capacity of the stromal cells because the proliferation of HSCs was suppressed to a great extent by the anti-PA6 mAb. Affinity chromatography and mass peptide fingerprinting revealed that the protein reacting with the anti-PA6 mAb is neural cell adhesion molecule (NCAM). The frequencies of long-term cobblestone area-forming cells and long-term culture-initiating cells were significantly suppressed by repression of NCAM in the FMS/PA6-P cells using NCAM small interfering RNA. Our findings clearly indicate that NCAM functions on the maintenance of HSCs.     

Bone marrow stromal cells as targets for gene therapy

The bone marrow (BM) is composed of the non-adherent hematopoietic and adherent stromal cell compartment. This adherent BM stromal cell fraction contains pluripotent mesenchymal stem cells (MSCs) and differentiated mesenchymal BM stromal cells. The MSCs self-renew by proliferation while maintaining their stem-cell phenotype and give rise to the differentiated stromal cells which belong to the osteogenic, chondrogenic, adipogenic, myogenic and fibroblastic lineages. A more primitive adherent stem cell was recently identified, the multipotent adult progenitor cell (MAPC) or mesodermal progenitor cell, which co-purifies with MSCs. These MAPCs differentiate into MSCs, endothelial, epithelial and even hematopoietic cells. BM stroma cells, including the primitive pluripotent MSCs and MAPCs, are attractive targets for cell and gene therapy. The BM stromal cell population and its multipotent stem cells can be engineered to secrete a series of different proteins in vitro and in vivo that could potentially treat a variety of serum protein deficiencies and other genetic or acquired diseases, including bone, cartilage and BM stromal disorders or even cancer.     

Functional neuronal differentiation of bone marrow-derived mesenchymal stem cells

Recent results have shown the ability of bone marrow cells to migrate in the brain and to acquire neuronal or glial characteristics. In vitro, bone marrow-derived MSCs can be induced by chemical compounds to express markers of these lineages. In an effort to set up a mouse model of such differentiation, we addressed the neuronal potentiality of mouse MSCs (mMSCs) that we recently purified. These cells expressed nestin, a specific marker of neural progenitors. Under differentiating conditions, mMSCs display a distinct neuronal shape and express neuronal markers NF-L (neurofilament-light, or neurofilament 70 kDa) and class III beta-tubulin. Moreover, differentiated mMSCs acquire neuron-like functions characterized by a cytosolic calcium rise in response to various specific neuronal activators. Finally, we further demonstrated for the first time that clonal mMSCs and their progeny are competent to differentiate along the neuronal pathway, demonstrating that these bone marrow-derived stem cells share characteristics of widely multipotent stem cells unrestricted to mesenchymal differentiation pathways.     

慢性粒细胞白血病患者骨髓间质干细胞的生物学特征的研究

目的： 研究不同来源（正常人、慢性粒细胞性白血病）骨髓间质干细胞的生物学特征及分化能力。 方法: 分离获取19例慢性粒细胞性白血病（CML）患者的骨髓间质干细胞，同时获取8例正常人的骨髓间质干细胞作为对照。获取的间质干细胞采用低血清培养液培养。瑞士染色观察形态，FACS检测其免疫表型和细胞周期，通过油红O和von Kossa染色来证实向脂肪和骨的分化情况。RT-PCR检测CML特异性表达的BCR/ABL基因；对正常人、CML患者的骨髓间质干细胞进行染色体分析。 结果: 正常人和CML骨髓间质干细胞具有相似的细胞形态、生长特性和免疫表型，而且都可以向骨和脂肪分化。CML来源的MSCs不表达BCR/ABL融合基因，并且具有正常的核型。 结论: 从CML骨髓中可以分离和培养出具有间质干细胞特性的细胞群体，其具有正常的核型且不表达BCR/ABL基因。CML和正常人骨髓间质干细胞具有相似的生物学特性和多向分化能力。     

Bone marrow microenvironment in an in vitro model of Gaucher disease: consequences of glucocerebrosidase deficiency

Gaucher disease (GD) is a lysosomal storage disorder due to glucocerebrosidase (GBA) deficiency. Mechanisms leading to the emergence of hematological and skeletal manifestations observed in GD are poorly explained. Bone marrow (BM) mesenchymal stem cells (MSCs) are multipotent progenitors that participate in the regulation of bone mass. MSCs should thus represent a cell population involved in the development or progression of bone disease in GD. In a chemical model of GD obtained with Conduritol β epoxide (CBE), a specific inhibitor of GBA activity, we functionally characterized BM MSCs and specifically analyzed their capacity to differentiate into osteoblasts. GBA deficiency obtained with CBE treatment, leads to a dramatic impairment of MSCs proliferation and to morphological abnormalities. Although the capacity of MSCs to differentiate into osteoblasts was not modified, the levels of several soluble factors that regulate bone metabolism were increased in MSCs treated with CBE, compared with untreated MSCs. Moreover, addition of conditioned media from CBE-treated MSCs on monocyte-derived osteoclasts cultured on bone matrix leads to an increase of resorption areas. These data suggested that, in GD, MSCs represents a stem cell population that is likely to be involved in bone pathogenesis.     

A novel monoclonal antibody (STRO-3) identifies an isoform of tissue nonspecific alkaline phosphatase expressed by multipotent bone marrow stromal stem cells

Numerous studies support the concept that the nonhemopoietic cells of the bone marrow (BM), are derived from a population of multipotent bone marrow stromal stem cells (BMSSCs), which reside in perivascular niches within the bone marrow. These BMSSCs are thought to give rise not only to more cells that are phenotypically and functionally identical but also differentiated, lineage-committed mesenchymal progeny, including chondrocytes, smooth muscle cells, adipocytes, and osteoblasts. Recently, we have generated a novel monoclonal antibody (mAb) (designated STRO-3) that reacts with a minor subset of STRO-1(+) cells contained within adult BM aspirates and does not react with CD34(+) hemopoietic stem cells. Our results also show that STRO-3 identifies a high proportion of BMSSCs that possess extensive proliferative and multilineage differentiative capacity. Using retroviral expression cloning, we determined that STRO-3 binds to tissue nonspecific alkaline phosphatase (TNSALP), a cell-surface glycoprotein usually associated with cells of the osteoblast lineage. Studies presented here suggest that in addition to being expressed by osteoblasts, TNSALP may also represent a marker of immature BMSSCs in vivo. Finally, these studies suggest that antibodies to TNSALP may be used as an effective single marker of enrichment of BMSSCs from various tissues.     

Comparative characterization of hair follicle dermal stem cells and bone marrow mesenchymal stem cells

We compared the growth and differentiation characteristics of hair follicle-derived dermal stem cells with bone marrow mesenchymal stem cells (MSCs). Follicular dermal cells were isolated from whisker hairs of Wistar rats and bone marrow MSCs were isolated from femora of the same animals. The adherent hair follicle dermal cells showed a fibroblastic morphology in serum-containing culture medium, were CD44(+), CD73(+), CD90(+), and CD34(), and had a population doubling time of 27 h. MSCs isolated from the bone marrow showed a similar morphology and population doubling time and expressed the same cell-surface markers. Following exposure to appropriate induction stimuli, both cell populations had the capacity to differentiate into various mesenchymal lineages, such as osteoblasts, adipocytes, chondrocytes, and myocytes and expressed neuroprogenitor cell markers. The rate and extent of differentiation were remarkably similar for both hair follicleand bone marrow-derived cells, whereas interfollicular dermal cells failed to differentiate. We identified telomerase activity in follicle dermal stem cells and marrow MSCs and demonstrated that they were capable of clonal expansion. In ex vivo analyses, we identified the presence of putative dermal stem cells in the dermal sheath and dermal papillae of the hair follicle. Consequently, the hair follicle may represent a suitable, accessible source for MSCs.     

Monoclonal antibodies against a preadipose cell line (MC3T3-G2/PA6) which can support hemopoiesis

Monoclonal antibodies against a mouse preadipose cell line (MC3T3-G2/PA6:PA6), which can support hemopoiesis by direct cell-to-cell interaction, were produced and characterized. The antibodies react with PA6 but not PA6-M (a mutant cell line) which has the capacity neither to contact with hemopoietic stem cells (HSCs) nor to support hemopoiesis. Endosteal cells in the bone marrow show positive staining to these antibodies. They inhibit pseudoemperipolesis of PA6 to HSCs, resulting in a significant decrease in hemopoietic cell number. These findings suggest that the monoclonal antibodies bind to the stromal cell receptors for HSCs and block the binding of HSCs to stromal cells leading to suppression of hemopoiesis.     

自体骨髓间充质干细胞在脊髓损伤中的应用展望

近年来研究发现 ,除了胚胎干细胞 ,机体内还存在一些组织干细胞 ,它们具有一定的自我更新和分化能力。在骨髓中存在一种间充质干细胞 (mesenchymalstemcells,MSCs) ,具有多向分化的潜能 ,在特定的条件下向成骨细胞 ,软骨细胞 ,脂肪细胞 ,神经细胞等方面分化。与其它的干细胞相比 ,骨髓间充质干细胞易于分离和培养扩增 ,还易于外源基因的导入和表达 ,有望成为一种新的细胞治疗和基因治疗的靶细胞。在此基础上本文探讨了骨髓自体间充质干细胞体外培养后移植 ,修复损伤脊髓的可行性     

凝血因子Ⅸ基因敲除对小鼠骨髓间充质干细胞生物学特性无直接影响

背景：凝血因子Ⅸ基因敲除有可能通过影响造血系统的稳定性从而影响骨髓造血微环境中骨髓间充质干细胞的生物学特性。 目的：鉴定凝血因子Ⅸ基因敲除C57BL/6J-F9 tm1. Dws小鼠骨髓间充质干细胞的生物学特征。 方法：采用改进的全骨髓贴壁细胞分离法分离培养凝血因子Ⅸ基因敲除C57BL/6J-F9 tm1. Dws小鼠骨髓间充质干细胞,流式细胞术鉴定其表面标记的表达,以特殊诱导培养基诱导骨髓间充质干细胞干向成骨细胞,脂肪细胞,软骨细胞方向分化。 结果与结论：分离的骨髓间充质干细胞形态均一为梭形,增殖能力和自我更新能力强。流式细胞术检测细胞表面标识CD44、CD56、CD73、CD90、CD105、CD106、CD166及CD271表达呈阳性,CD34、CD11b表达呈阴性。分离的骨髓间充质干细胞具有向成骨细胞,脂肪细胞,软骨细胞方向分化的能力。说明凝血因子Ⅸ基因敲除C57BL/6J-F9 tm1. Dws小鼠的骨髓间充质干细胞仍具备良好的干细胞的生物学特性,初步确定,凝血因子Ⅸ基因敲除对骨髓间充质干细胞的生物学特性并无直接影响。     

Capability of human mesenchymal cells isolated from different sources to differentiation into tissues of mesodermal origin

We compared the capacity of cultured human skin fibroblasts, human umbilical cord cells obtained after normal delivery on gestation week 38–40, and mesenchymal bone marrow stem cells to differentiation into adipocytes, osteoblasts, and chondrocytes. Our findings suggest that mesenchymal stem cells are multipotent cells and can differentiate into adipose, cartilaginous, and bone tissue. Umbilical cord fibroblast-like cells can differentiate into adipocytes and chondrocytes, and only few cells in this culture can differentiate into osteoblasts. Skin fibroblasts differentiate only into adipocytes. __________ Translated from Kletochnye Tehnologii v Biologii i Medicine, No. 1, pp. 3–10, January, 2007     

骨髓基质干细胞向神经细胞诱导分化及其机制的研究进展

骨髓基质干细胞是一种存在于骨髓间质中具备多向分化潜能的成体干细胞,其不仅能分化为中胚层起源的骨、软骨和脂肪细胞,还可以在特定条件下诱导分化为神经外胚层起源的神经细胞。主要对骨髓基质干细胞向神经细胞诱导分化及其机制的研究进展作一综述。     

Fetal membranes as a source of stem cells

In recent years, a constant growth of knowledge and clinical applications of stem cells have been observed. Mesenchymal stromal cells, also described as mesenchymal stem cells (MSCs) represent a particular cell type for research and therapy because of their ability to differentiate into mesodermal lineage cells. The most investigated source of MSCs is bone marrow (BM). Yet, collection of BM is an invasive procedure associated with significant discomfort to the patient. The procedure results in a relatively low number of these cells, which can decrease with donor's age. Therefore, it seems to be very important to find other sources of mesenchymal stem cells nowadays. A human placenta, which is routinely discarded postpartum, in spite of its natural aging process, is still a rich source of stem cells capable to proliferate and in vitro differentiate in many directions. Besides homing and differentiation in the area of injury, MSCs there elicit strong paracrine effects stimulating the processes of repair. In this review, we focus on the biology, characteristics and potential clinical applications of cells derived from human fetal membranes: amnion and chorion.     

犬骨髓间充质干细胞分离培养及鉴定

目的建立犬髂骨骨髓间充质干细胞分离、培养的方法,并对间充质干细胞进行鉴定。方法采用密度梯度分离和贴壁培养相结合的方法分离培养犬的骨髓间充质干细胞(MSCs),并诱导间充质干细胞向成骨细胞、成脂肪细胞方向分化。相差显微镜观察其形态学变化,组化染色测定其分化结果。结果原代培养4～5d,镜下见细胞呈梭形或多角形,有较多的突起,胞核明显呈卵圆形,可见1-3个核仁,胞质丰富。成骨方向诱导形成的矿化结节茜素红染色阳性,碱性磷酸酶(alkaline phosphatase,ALP)染色阳性;成脂方向诱导形成的脂肪细胞苏丹Ⅳ染色阳性。结论采用密度梯度分离和贴壁培养相结合的方法能够成功分离和培养犬的骨髓间充质干细胞。     

Adipocyte differentiation of human marrow mesenchymal stem cells reduces the supporting capacity for hematopoietic progenitors but not for severe combined immunodeficiency repopulating cells

Bone marrow stromal cells provide a microenvironment for hematopoiesis. Adipocytes are the major stromal cell phenotype in bone marrow, but their function in hematopoiesis is poorly understood. In this study, we compared the hematopoietic-supporting capacity of adipocytes and their progenitor, mesenchymal stem cells (MSCs), by culturing human cord blood (CB) CD34+CD38- hematopoietic progenitor cells (HPCs) on a layer of adipocytes or MSCs. CB CD34+CD38- cells cultured on MSCs generated higher proportions of CD34+CD38- HPCs and colony-forming cells than those cultures on a layer of adipocytes, indicating an inferior hematopoietic support by adipocytes. However, CB CD34+CD38- HPCs cultured on MSCs and adipocytes were equally capable of reconstituting human hematopoiesis in non-obese diabetic/severe combined immunodeficient disease (NOD/SCID) mice. These findings show that differentiation of MSCs into adipocytes is accompanied by the loss of capacity to support mature HPCs, but not transplantable SCID-repopulating cells.