Alkaline phosphatase, glutathione-S-transferase-P, and cofilin-1 distinguish multipotent mesenchymal stromal cell lines derived from the bone marrow versus peripheral blood

Multipotent mesenchymal stromal cells (MSCs) can be isolated from bone marrow or peripheral blood. To identify phenotypical and functional differences between MSCs derived from these sources, the human bone marrow-derived, fibroblast-like cell line L87/4 was compared with the peripheral blood-derived, fibroblast-like cell line V54/2. Both cell lines expressed similar levels of SH3+, CD45(-), CD68(-), CD133(-), and HLA-DR(-). The bone marrow-derived cells expressed higher surface levels of CD105, CD10, and CD117 and preferentially expressed alkaline phosphatase, glutathione S-transferase P, and cofilin-1. The peripheral blood-derived line showed a higher number of CD34+/CD105+ double-positive and side population (SP) cells. The results demonstrate the more multipotent, yet quiescent, stromal phenotype of bone marrow MSCs, whereas MSCs isolated from the circulation display more hematopoietic-lineage characteristics. Importantly, potential marker genes that distinguish the two stages of MSCs are defined.     

High levels of functional endopeptidase 24.11 (CD10) activity on human thymocytes: preferential expression on immature subsets.

Although it is now well established that cells of the immune system express most of the exopeptidases described so far, little information is available concerning the identification and the characterization of the peptidases associated with the surface of human thymocytes. In the present study we have focused on CD10 expression on thymocytes using both FACS and enzymatic analysis. Unfractionated intact human thymocytes were shown to express significant levels of CD10-specific enzymatic activity, as assessed by the hydrolysis of the neutral endopeptidase (NEP) substrate Suc-Ala-Ala-Phe-pNA and of D-Ala2-Leu-enkephalin, a typical NEP substrate. CD10 activity was abolished by specific NEP inhibitors, including thiorphan, retrothiorphan and phosphoramidon. Moreover, high performance liquid chromatography (HPLC) analysis showed that intact thymocytes and purified NEP hydrolysed thymopentin, a thymic factor known to induce the maturation of prothymocytes into thymocytes. Finally, CD 10/NEP was preferentially associated with CD3- CD3low and immature CD4- CD8- thymocytes. The data demonstrate for the first time that human thymocytes express functional NEP and suggest a role for this enzyme in the maturation of human thymocytes.     

A regulatory role for Fc gamma receptors (CD16 and CD32) in hematopoiesis.

Progenitor cells of the T- and B-lineages in mice express (CD32) and Fc gamma RIII (CD16) but as the developing lymphocytes begin to express clonal antigen receptors, CD16 and CD32 are downregulated in T-cells, and CD16 is downregulated in B-cells. Considering that counter-receptors for Fc gamma R occur on thymic and bone marrow stromal cells, the possibility exists that Fc gamma R might participate in some aspect of T- and B-lineage development prior to the stage of antigen receptor expression. Previous studies provided evidence that Fc gamma R can influence murine T-lineage development. In the present studies we found that anti-Fc gamma RII/III mAb accelerated B-lineage development in bone marrow cultures from normal mice, but not in cultures from CD16-/- or CD32-/- mice. Similar results were observed when FACS-purified B-progenitor cells were co-cultured with BMS2, a bone marrow stromal cell line. Fresh bone marrow from CD32-/- mice contained about two-fold more B-lineage cells compared to bone marrow from normal or CD16-/- mice. These studies indicate that the Fc gamma R on B-lineage progenitor cells can influence their further development and add to a growing body of evidence that implicates Fc gamma R as regulatory elements in hematopoiesis.     

CD10+ stromal cells form B-lymphocyte maturation niches in the human bone marrow

In adult mammals, early B-lymphopoiesis takes place in the bone marrow in close association with stromal cells. Both the phenotype of the stromal cells and the molecules involved in this essential interaction are as yet inadequately described. In this study, all benign, differentiating B-cells (Pax-5+ lymphoid cells) are shown, by using two-colour immunohistochemistry on biopsies from human bone marrow, to be in close contact with scant dendritic CD10+ stromal cells until they leave via the sinusoids. This CD10+ stromal cell population does not fully overlap with the VCAM-1+ stromal cell population. Furthermore, using a set of B-cell differentiation markers (TdT, Pax-5, and CD20), B-cell development is shown to be spatially oriented, with maturation progressing towards bone marrow sinusoids. In conclusion, CD10+ stromal cells form distinct B-lymphocyte maturation niches in the human bone marrow.     

Induction of murine CD5 expression by v-H-ras.

The murine CD5 surface antigen is a frequent marker on B-lineage cell lines produced from bone marrow infected with retroviruses expressing v-H-ras. Since CD5+ B cells cannot be detected in adult murine bone marrow, either the viral targets of transformation are a minor contaminating population of CD5+ B-lineage cells or the v-H-ras oncogene is inducing the expression of CD5 on B-lineage cells not previously expressing this marker. We have found that v-H-ras can induce the expression of CD5 on two CD5+ pre-B-cell lines established from murine bone marrow. This induction correlates with increased steady-state levels of CD5 mRNA. These results present the possibility that CD5 expression may be modulated by specific signalling as well as early lineage commitment.     

Independent regulation of ABCB1 and ABCC activities in thymocytes and bone marrow mononuclear cells during aging

Aging modifies a number of functional and phenotypic parameters of cells from the immune system. In this study, the activities of two members of the superfamily of ATP-binding cassette (ABC) transport proteins, ABCB1 and ABCC (measured by rhodamine 123 efflux and Fluo-3 efflux respectively), were compared in murine bone marrow cells and thymocytes of young (3-4 weeks old), adult (2-3 months old) and old (18 months old) mice. ABCB1 activity was shown to be age regulated in murine bone marrow mononuclear cells and thymocytes. In the bone marrow, the increased amount of cells with ABCB1 activity observed in old mice was restricted to the c-kit(-)Sca-1(+) and c-kit(+)Sca-1(+) subpopulations. Only a small percentage of c-kit(+) cells in the thymus had ABCB1 activity, and this subpopulation increased with age. In the thymus, old age augmented this activity in the CD4(-) CD8(-) double-negative cells and in the CD4(+) and CD8(+) single-positive populations. The activity of another ABC transporter, the ABCC-related activity, was also modified by age in the bone marrow. However, the age-related increase was observed in the subpopulations were ABCB1 was not modified, namely the non-progenitor population (c-kit(-)Sca-1(-)cells) and c-kit(+)Sca-1(-) cells. Nearly, all thymocytes expressed the ABCC1 molecule in an active form and aging did not affect this pattern. This study demonstrates an independent upregulation of ABCB1 and ABCC activities during the aging process. The increases were observed in different subsets of cells but followed a developmentally regulated pattern. The functions played by these transporters and alterations in aging are discussed.     

哮喘小鼠气道上皮TSLP表达及激活DCs加重气道炎症的研究

目的 研究支气管哮喘小鼠气道上皮中胸腺间质淋巴细胞生成素(TSLP)表达,探讨其对哮喘小鼠肺部炎症的影响.方法 BALB/c小鼠分为生理盐水对照组、哮喘模型组和TSLP中和抗体干预组.通过气道反应性和肺组织病理学评价哮喘模型;酶联免疫吸附试验(ELISA)检测支气管肺泡灌洗液(BALF)上清中IL-4、IL-5和IL13的含量;实时荧光定量PCR(qRT-PCR)测定肺组织中TSLP mRNA的表达;免疫组化及Western blot法测定肺组织中TSLP蛋白的表达;流式细胞术检测BALF中树突状细胞(OCs)表面CD40、CD80、CD86的表达水平.结果 小鼠气道反应性增高和肺组织病理学检查结果均符合哮喘的典型表现证实造模成功;哮喘组BALF中IL-4、IL-5和IL-13的水平显著高于正常组(P<0.05),且TSLP与其成正相关;与正常对照组相比,哮喘组气道上皮TSLPmRNA和蛋白高表达,两组间差异有统计学意义(P<0.05);哮喘组BALF中DCs表面CD40、CD80、CD86表达明显高于正常组(P<0.05).TSLP中和抗体干预后,BALF中DCs表面CD40、CD80、CD86表达明显减低,并进一步减少IL-4、IL-5和IL-13的表达.结论 哮喘气道上皮中TSLP表达增高,TSLP通过上调DCs表面CD40、CD80、CD86的表达,激活DCs诱导CD4~+T细胞向Th2分化发育,与加重哮喘的气道炎症有关;TSLP抗体干预可阻断DCs的活化,减少Th2细胞因子的分泌,这些因素可能与减轻哮喘炎症反应有关,为哮喘治疗途径提供新的思路.     

还原型谷胱苷肽对骨髓基质干细胞增殖及向神经样细胞分化的影响

BACKGROUND:As bone marrow stromal stem cells can be easily obtained and have multi-directional differentiation potential, it is an important approach to obtain neural stem cells for treatment of spinal cord injury through induced differentiation of bone marrow stromal stem cells. OBJECTIVE:To observe the effects of different concentrations of reduced glutathione on proliferation and neuronal differentiation of bone marrow stromal stem cells. METHODS:Bone marrow stromal cells were isolated and cultured by limited dilution method. The cloned bone marrow stromal cells were stimulated with reduced glutathione at different concentrations (0, 5, 10, 20, 40 mmol/L) respectively. After 72 hours of culture, proliferation of bone marrow stromal cells was examined by MTT assay. The morphology of bone marrow stromal cells was observed under inverted microscope and the cells were identified by immunofluorescence staining of microtubule associated protein-2 and glial fibrillary acidic protein. RESULTS AND CONCLUSION:We found that 5 mmol/L reduced glutathione medium could promote the proliferation of bone marrow stromal cells (P < 0.05), but reduced glutathione at 20 and 40 mmol/L inhibited the cell proliferation (P < 0.05). The number and size of cell colonies in the 10 mmol/L reduced glutathione group had no obvious difference from the control group. Reduced glutathione at 10 mmol/L was powerful to induce the neuronal differentiation of bone marrow stromal stem cells, and most cells expressed microtubule associated protein-2 and glial fibrillary acidic protein. A random selection of 5 fields of view was conducted and percentage of bone marrow stromal cells differentiating into neuron-like cells was calculated as (62.0±4.8)%. These results confirmed that low-concentration (5 mmol/L) reduced glutathione can promote the proliferation of bone marrow stromal cells, while 10 mmol/L reduced glutathione has a strong induction of bone marrow stromal cells differentiating into neuron-like cells.     

Effect of angiotensin II on hematopoietic progenitor cell proliferation

Angiotensin II (AII) induced the proliferation of hematopoietic progenitor cells (HPC) isolated from murine bone marrow or human cord blood. The formation of colonies with more than 50 cells increased approximately five-sevenfold in cultures of murine lineage-negative (Lin(-)) bone marrow cells both in the presence (day 10) and absence (day 13) of colony-stimulating factors (CSF). This could be blocked with addition of Losartan, an antagonist of AIITR1. The increase in proliferation of early hematopoietic progenitors (Lin(-)Sca l(+) cells) by AII was approximately threefold and occurred only in the presence of CSF, suggesting that AII may affect mesenchymal stromal cells to induce CSF production and might directly affect early HPC. These in vitro studies were replicated with human HPC isolated from cord blood. AII also accelerated the proliferation and formation of colony-forming units (CFU)-granulocyte/erythroid/macrophage/megakaryocyte and CFU-granulocyte/macrophage colonies by CD34(+)CD38(-) enriched progenitors but only in the presence of CSF. Additional studies also indicated that AII can act to increase proliferation in suspension culture. Exposure of CD34(+) cells to AII in suspension culture, prior to placement in a semisolid medium with erythropoietin, increased the formation of colonies with more than 50 cells and erythroid progenitors approximately five- and 20-fold, respectively. Further, mRNA for the AT1a receptor was expressed by human bone marrow CD34(+)CD38(-) cells, CD34(+)CD38(-) cells, and lymphocytes, but not mature myeloid cells. Similarly, mRNA for the AT1a receptor was expressed on human stromal cell clones, offering further support to the hypothesis that AII acts partially through the mesenchymal compartment of the bone marrow. These data suggest that AII may be a factor which stimulates the proliferation of hematopoietic progenitors.     

高原红细胞增多症模型大鼠骨髓CD71~+细胞GATA-1和GATA-2表达的相关性

目的:探讨高原红细胞增多症(HAPC)模型大鼠骨髓CD71+细胞转录因子GATA-1和GATA-2表达的相关性。方法:雄性SD大鼠48只,随机分为对照组和HAPC模型组。在海拔4 300 m自然环境下复制HAPC模型并采用骨髓涂片、骨髓细胞分类计数和血液学参数检测进行验证。流式细胞术检测骨髓CD71~+细胞数量相对变化趋势;RT-q PCR和Western blot法检测GATA-1和GATA-2的mRNA和蛋白表达变化,低氧培养CD71~+细胞,筛选最佳干扰序列GATA-1 shRNA1后,转染96 h,RT-q PCR和Western blot法检测GATA-1和GATA-2的mRNA和蛋白表达水平。结果:骨髓细胞分类计数、涂片及血液学参数检测结果显示,HAPC大鼠模型复制成功。与对照组比较,HAPC模型组骨髓CD71~+细胞明显增多,骨髓CD71~+细胞GATA-1的mRNA和蛋白表达增高,GATA-2的mRNA和蛋白表达差异无统计学显著性。对照组GATA-1和GATA-2的mRNA和蛋白表达呈负相关,HAPC模型组GATA-1和GATA-2的mRNA和蛋白表达无显著相关性。GATA-1 shRNA1干扰96 h后,GATA-1的mRNA和蛋白表达低于对照组,但是GATA-2的mRNA和蛋白表达变化差异无统计学显著性。结论:HAPC大鼠骨髓CD71+细胞GATA-1和GATA-2表达异常,两者的负相关关系改变可能是导致HAPC发生的机制之一。     

Isolation of C15: a novel antibody generated by phage display against mesenchymal stem cell-enriched fractions of adult human marrow

Adult bone marrow stroma contains a source of mesenchymal stem cells (MSC) that have the capacity to self-renew and differentiate into multiple stromal lineages. These rare cells can be visualised indirectly by the formation of heterogeneous colonies, containing stem cells and their differentiated progeny in long-term culture. If MSC and their associated progenitor and precursor populations are to reach their full therapeutic potential, markers will be required to identify and characterize specific bone marrow stromal subsets. We sought to use phage display to generate antibodies against bone marrow mononuclear cells (BMMNC) enriched for colony forming cells. Initially, we identified our target cell population by comparing the colony forming efficiency (CFE) of CD49a-positive, STRO-1-positive and CD45-negative BMMNC subpopulations with unseparated BMMNC. Selection with anti-CD49a gave the greatest enrichment (19-fold) of colony forming cells and in light of these findings, we generated phage antibodies against CD49a-positive BMMNC by simultaneous positive/negative selection. A dominant clone (C15), generated after 3 rounds of selection, has been isolated and sequenced, then characterized for cell and tissue specificity. Sequence analysis showed that the V(H) and V(L) gene segments of C15 aligned most closely to the VH26/DP-47 and IGLV3S1/DPL16 germline V segments found in the synthetic repertoire. C15 bound to 4% of freshly isolated BMMNC and localized to osteoblastic cells and proximal marrow cells in areas of active bone formation in sections of osteophyte. C15 binding was upregulated in cultured bone marrow stromal cells (BMSC) and was also detected on bone-derived cell lines. This report demonstrates that phage display is a powerful tool for the isolation of antibodies against rare cell populations, and provides a platform for the future application of this technology in the search for antigens on MSC and other rare cell populations.     

3种组织来源的间充质干细胞体外成骨能力的比较

目的比较成人骨髓间充质干细胞(BMSCs)、人脐带间充质干细胞(UC-MSCs)和人胎盘间充质干细胞(P-MSCs)的成骨能力。方法用含10%胎牛血清的DMEM/Ham's F-12培养液培养3种MSCs,CCK8法检测增殖能力,流式细胞仪鉴定3种细胞。碱性磷酸酶(ALP)和茜素红染色观察细胞经成骨诱导后成骨分化蛋白-ALP的分泌和矿化钙结节的沉积。实时荧光定量PCR(RT-q PCR)法检测MSCs骨再生相关基因的表达。Western blot方法检测MSCs成骨再生相关基因的蛋白表达。结果 MSCs在第3天进入对数增殖期。3种细胞的表面标志物阳性率:CD44、CD90和CD105均高于98%。3种MSCs成骨诱导9 d时,3种MSCs的实验组均表达大量成骨分化蛋白-ALP,成骨诱导18 d时3种MSCs均呈现较好的矿化能力;3种MSCs成骨诱导9 d时,实验组RUNX2和ALP基因显著性高表达(P0.05),成骨诱导18 d时,实验组RUNX2和骨钙素(OCN)亦显著性高表达(P0.05);3种MSCs成骨诱导9 d时,实验组均检测到RUNX2和ALP的蛋白表达;成骨诱导18 d时,实验组细胞亦检测到RUNX2和OCN的蛋白表达。结论 UC-MSCs和P-MSCs具有良好的成骨分化能力,有望作为骨组织工程的种子细胞用于治疗骨缺损。     

A phenotypically distinct subset of immature B cells exhibits partial activation, increased survival, and preferential expression of VhS107

We have observed that immature B cells (IgM(low)IgD(-)) in the bone marrow of adult BALB/c mice exhibit heterogeneity, with a distinct subpopulation ( approximately 4-10%) expressing the CD43/S7 surface protein. These CD43/S7(+) immature B cells often express other surface antigens associated with B cell activation (CD5, CD11b, PD-1). Generation of optimal numbers of CD43/S7(+) immature B cells requires expression of a functional Btk protein, consistent with activation as a requisite for the CD43/S7(+) immature B cell phenotype. Like typical CD43/S7(-) immature B cells, the CD43/S7(+) immature B cells are predominantly resting cells, which are derived from cycling bone marrow B cell precursors. The CD43/S7(+) immature B cell population exhibits enhanced survival in vivo upon administration of the apoptosis-inducing corticosteroid, dexamethasone. Finally, CD43/S7(+) immature B cells show a fourfold increase in incidence of VhS107 micro heavy chain expression compared to the CD43/S7(-) immature B cells. Therefore, in adult murine bone marrow, the presence of a phenotypically distinct immature B cell population can be demonstrated which has undergone partial activation leading to increased survival and BCR-dependent Vh repertoire selection.     

Expression of CD34 in endothelial cells,hematopoietic progenitors and nervous cells in fetal and adult mouse tissues

The human cell surface molecule CD34 is selectively expressed on uncommitted and committed hematopoietic progenitor cells and on vascular endothelial cells. It has been suggested that CD34 regulates early events in blood cell migration and differentiation, possibly as a cell adhesion molecule. To characterize the patterns of expression of CD34 in the mouse embryo and in the adult, as well as to dissect the function of different portions of the extracellular domain of this molecule, we have generated the first monoclonal antibodies (mAb) specific for mouse CD34. The epitope(s) recognized by these mAb are not carbohydrate moieties, and are comprised either within the immunoglobulin-like domain or within a portion of the mucin domain, containing approximately half of the predicted O- and N-linked carbohydrate attachment sites. The specificity of the antibodies was established by ELISA and Western blotting. Western analysis revealed that these mAb recognize a protein of approximately 110 kDa in PA6 stromal cell lysates, which can be specifically blocked by the recombinant CD34 protein. To establish the reactivity of these mAb on different cell lineages, a panel of cell lines was stained. This analysis showed strong reactivities with 3T3 fibroblasts, stromal cell lines from fetal liver and with the endothelial cell line D10. Bone marrow hematopoietic progenitors were also stained by these mAb. Immunostaining of frozen sections from embryonic and adult tissues revealed a strong reactivity against vascular endothelial cells at different stages of development, including sinusoidal cells in the fetal liver, yolk sac, and in the fetal bone marrow, endothelial cells from adult lung and kidney, and neural cells, including those of the neural tube of midgestation embryos and neuronal bodies in adult brain.