Characterization and evaluation of mesenchymal stem cells derived from human embryonic stem cells and bone marrow

Embryonic stem cells (ESCs) and mesenchymal stem cells (MSCs) have been studied for years as primary cell sources for regenerative biology and medicine. MSCs have been derived from cell and tissue sources, such as bone marrow (BM), and more recently from ESCs. This study investigated MSCs derived from BM, H1- and H9-ESC lines in terms of morphology, surface marker and growth factor receptor expression, proliferative capability, modulation of immune cell growth and multipotency, in order to evaluate ESC-MSCs as a cell source for potential regenerative applications. The results showed that ESC-MSCs exhibited spindle-shaped morphology similar to BM-MSCs but of various sizes, and flow cytometric immunophenotyping revealed expression of characteristic MSC surface markers on all tested cell lines except H9-derived MSCs. Differences in growth factor receptor expression were also shown between cell lines. In addition, ESC-MSCs showed greater capabilities for cell proliferation, and suppression of leukocyte growth compared to BM-MSCs. Using standard protocols, induction of ESC-MSC differentiation along the adipogenic, osteogenic, or chondrogenic lineages was less effective compared to that of BM-MSCs. By adding bone morphogenetic protein 7 (BMP7) into transforming growth factor beta 1 (TGFβ1)-supplemented induction medium, chondrogenesis of ESC-MSCs was significantly enhanced. Our findings suggest that ESC-MSCs and BM-MSCs show differences in their surface marker profiles and the capacities of proliferation, immunomodulation, and most importantly multi-lineage differentiation. Using modified chondrogenic medium with BMP7 and TGFβ1, H1-MSCs can be effectively induced as BM-MSCs for chondrogenesis.     

Comparison of the Neural Differentiation Potential of Human Mesenchymal Stem Cells from Amniotic Fluid and Adult Bone Marrow

Human mesenchymal stem cells (MSCs) are considered a promising tool for cell-based therapies of nervous system diseases. Bone marrow (BM) has been the traditional source of MSCs (BM-MSCs). However, there are some limitations for their clinical use, such as the decline in cell number and differentiation potential with age. Recently, amniotic fluid (AF)-derived MSCs (AF-MSCs) have been shown to express embryonic and adult stem cell markers, and can differentiate into cells of all three germ layers. In this study, we isolated AF-MSCs from second-trimester AF by limiting dilution and compared their proliferative capacity, multipotency, neural differentiation ability, and secretion of neurotrophins to those of BM-MSCs. AF-MSCs showed a higher proliferative capacity and more rapidly formed and expanded neurospheres compared to those of BM-MSCs. Both immunocytochemical and quantitative real-time PCR analyses demonstrated that AF-MSCs showed higher expression of neural stemness markers than those of BM-MSCs following neural stem cell (NSC) differentiation. Furthermore, the levels of brain-derived growth factor and nerve growth factor secreted by AF-MSCs in the culture medium were higher than those of BM-MSCs. In addition, AF-MSCs maintained a normal karyotype in long-term cultures after NSC differentiation and were not tumorigenic in vivo. Our findings suggest that AF-MSCs are a promising and safe alternative to BM-MSCs for therapy of nervous system diseases.     

骨髓间充质干细胞无血清培养

为建立一种化学成分明确的、能用于体外扩增骨髓间充质干细胞的无血清培养基, 且骨髓间充质干细胞经无血清培养扩增后仍能保持其多向分化的潜能。采用密度梯度离心结合贴壁法从1月龄新西兰大白兔股骨中分离骨髓间充质干细胞, 比较在含10%胎牛血清的培养基(SCM)和自制的化学成分明确的无血清培养基(CDSFM)中骨髓间充质干细胞的形态、增殖能力, 以及扩增后的骨髓间充质干细胞的细胞周期、集落形成能力和成骨、成脂肪分化能力。经过10 d的培养, 骨髓间充质干细胞在自制的无血清培养基中扩增了50倍, 在含10%胎牛血清的培养基中扩增了40倍。在无血清和有血清培养基中扩增后的细胞中G0/G1期比例分别为(80.31%±0.6%)和(75.24%±4.0%), 两者无显著差异(P>0.05)。无血清培养扩增后的骨髓间充质干细胞集落形成率(12.7%±4.0%)低于有血清培养组(28.7%±4.2%), 两者比较差异显著(P<0.01)。经过无血清培养扩增的骨髓间充质干细胞在成骨、成脂肪诱导分化培养基中能够分化成成骨和脂肪细胞。自制的化学成分明确的无血清培养基能够在体外培养扩增骨髓间充质干细胞, 并且维持其干细胞特性, 可以用于细胞治疗以及生物医学研究。     

Comparative investigation of the differentiation capability of bone-marrow- and adipose-derived mesenchymal stem cells by qualitative and quantitative analysis

Mesenchymal stem cells (MSCs) hold promise for cell-based therapy in regenerative medicine. To date, MSCs have been obtained from conventional bone marrow via a highly invasive procedure. Therefore, MSCs are now also isolated from sources such as adipose tissue, cord blood and cord stroma, a subject of growing interest. As the characterization and differentiation potential of adipose-derived MSCs (AD-MSCs) and bone-marrow-derived MSCs (BM-MSCs) have not been documented, we have evaluated and compared the characteristics of both MSC types by qualitative and quantitative analyses. Both cell types show similar morphology and surface protein expression, being positive for stromal-associated markers and negative for hematopoietic and endothelial markers. The colony-forming potential of AD-MSCs is distinctly higher than that of BM-MSCs. Nonetheless, similar adipogenic and osteogenic differentiation is observed in both groups of MSCs. Cytochemical qualitative analysis and calcium mineralization demonstrate higher levels toward osteogenic differentiation in BM-MSCs than in AD-MSCs. On the contrary, the percentage of Nile red oil staining for differentiated adipocytes is higher in AD-MSCs than in BM-MSCs. Quantitative real-time polymerase chain reaction shows similar patterns of osteogenic- and adipogenic-associated gene expression in both cell types. Each of the MSCs respond in functional analysis by exhibiting unique properties at the differentiation level according to their micro-environmental niche. Thus, quantitative analysis might be a valuable means of describing stem cell multipotency, in addition to qualitative investigation.     

Mesenchymal stem cells from human bone marrow or adipose tissue differently modulate mitogen-stimulated B-cell immunoglobulin production in vitro

Mesenchymal stem cells (MSC) have been characterized as multipotent cells which are able to differentiate into several mesodermal and nonmesodermal lineage cells and this feature along with their extensive growth and comprehensive immunomodulatory properties establish them as a promising tool for therapeutic applications, including cell-based tissue engineering and treatment of immune-mediated disorders. Although bone marrow (BM) is the most common MSC source, cells with similar characteristics have been shown to be present in several other adult tissues. Adipose tissue (AT), large quantities of which can be easily obtained, represents an attractive alternative to BM in isolating adipose tissue-derived MSC (AT-MSC). BM-MSCs and AT-MSCs share some immunomodulatory properties as they are both not inherently immunogenic and suppress the proliferation of alloantigen- or mitogen-stimulated T-cells. Our purpose was to comparatively examine under appropriate in vitro conditions, phenotypes, morphology and some functional properties of BM-MSCs and AT-MSCs, such as differentiation potential and especially the ability to suppress the immunoglobulin production by mitogen-stimulated B-cells. While the morphological, immunophenotypical, colony-forming and adipogenic characteristics of both types of cells were almost identical, AT-MSCs showed less potential for osteogenic differentiation than BM-MSCs. We found that AT-MSCs not only inhibited the Ig-production but also suppressed this B-cell function to a much greater extent compared to BM-MSC. This finding supports the potential role of AT-MSCs as an alternative to BM-MSCs for clinical purposes.     

树鼩骨髓间充质干细胞体外分离培养及成脂成骨诱导

目的：探讨树鼩骨髓间充质干细胞（ BM-MSCs）的体外分离、传代及定向诱导为脂肪细和成骨细胞的可行性。方法通过密度梯度离心联合贴壁培养法对树鼩骨髓间充质干细胞进行体外分离、扩增、纯化,倒置相差显微镜进行形态学观察。用成脂诱导液（ DMEM/F12＋10％FBS＋100 U/mL青霉素＋100μg/mL链霉素＋1.0μmol/L地塞米松＋0.2 mmol/L吲哚美辛＋0.01 mg/mL胰岛素＋0.5 mmol/L IBMX）和成骨诱导液（高糖DMEM＋10％FBS＋100 U/mL青霉素＋100μg/mL链霉素＋50 ng/mL BMP-2）对分离的树鼩BM-MSCs分别定向诱导为脂肪细胞和成骨细胞。结果原代和传代细胞为梭形或三角形,可增殖形成克隆。 BM-MSCs成脂诱导后油红O染色细胞内出现红色脂滴,成骨诱导后茜素红染色可观察到矿化结节。结论密度梯度离心联合贴壁培养法分离培养树鼩BM-MSCs简便可行,获得的BM-MSCs可体外诱导分化为脂肪细胞和成骨细胞。     

Resveratrol mimics insulin activity in the adipogenic commitment of human bone marrow mesenchymal stromal cells

Bone marrow mesenchymal stromal cells (BM-MSCs) are multipotent cells capable of differentiating toward osteoblatic and adipocytic phenotypes. BM-MSCs play several key roles including bone remodeling, establishment of hematopoietic niche and immune tolerance induction. Here, we investigated the effect of resveratrol (RSV), a therapeutically promising natural polyphenol, on the commitment of human BM-MSCs primary cultures. Cell differentiation was evaluated by means of morphological analysis, specific staining and expression of osteogenic and adipocytic master genes (Runx-2, PPARγ). To maintain BM-MSC multipotency, all experiments were performed on cells at very early passages. At any concentration RSV, added to standard medium, did not affect the phenotype of confluent BM-MSCs, while, when added to osteogenic or adipogenic medium, 1 μM RSV enhances the differentiation toward osteoblasts or adipocytes, respectively. Conversely, the addition of higher RSV concentration (25 μM) to both differentiation media resulted exclusively in BM-MSCs adipogenesis. Surprisingly, the analysis of RSV molecular effects demonstrated that the compound completely substitutes insulin, a key component of adipogenic medium. We also observed that RSV treatment is associated to enhanced phosphorylation of CREB, a critical effector of insulin adipogenic activity. Finally, our observations contribute to the mechanistic elucidation of the well-known RSV positive effect on insulin sensitivity and type 2 diabetes mellitus.     

Notch signalling inhibits the adipogenic differentiation of single‐cell‐derived mesenchymal stem cell clones isolated from human adipose tissue

ADSCs (adipose‐derived mesenchymal stem cells) are candidate adult stem cells for regenerative medicine. Notch signalling participates in the differentiation of a heterogeneous ADSC population. We have isolated, human adipose tissue‐derived single‐cell clones using a cloning ring technique and characterized for their stem cell characteristics. The role of Notch signalling in the differentiation capacity of these adipose‐derived single‐cell‐clones has also been investigated. All 14 clones expressed embryonic and mesenchymal stem cell marker genes. These clones could differentiate into both osteogenic and adipogenic lineages. However, the differentiation potential of each clone was different. Low adipogenic clones had significantly higher mRNA expression levels of Notch 2, 3 and 4, Jagged1, as well as Delta1, compared with those of high adipogenic clones. In contrast, no changes in expression of Notch signalling component mRNA between low and high osteogenic clones was found. Notch receptor mRNA expression decreased with the adipogenic differentiation of both low and high adipogenic clones. The γ‐secretase inhibitor, DAPT (N‐[N‐(3,5‐difluorophenacetyl)‐l ‐alanyl]‐(S)‐phenylglycine t‐butyl ester), enhanced adipogenic differentiation. Correspondingly, cells seeded on a Notch ligand (Jagged1) bound surface showed lower intracellular lipid accumulation. These results were noted in both low and high adipogenic clones, indicating that Notch signalling inhibited the adipogenic differentiation of adipose ADSC clones, and could be used to identify an adipogenic susceptible subpopulation for soft‐tissue augmentation application.     

Defective Self-Renewal and Differentiation of GBA-Deficient Neural Stem Cells Can Be Restored By Macrophage Colony-Stimulating Factor

Gaucher disease (GD) is an autosomal recessive lysosomal storage disorder caused by mutations in the glucocerebrosidase gene (GBA), which encodes the lysosomal enzyme glucosylceramidase (GCase). Deficiency in GCase leads to characteristic visceral pathology and lethal neurological manifestations in some patients. Investigations into neurogenesis have suggested that neurodegenerative disorders, such as GD, could be overcome or at least ameliorated by the generation of new neurons. Bone marrow-derived mesenchymal stem cells (BM-MSCs) are potential candidates for use in the treatment of neurodegenerative disorders because of their ability to promote neurogenesis. Our objective was to examine the mechanism of neurogenesis by BM-MSCs in GD. We found that neural stem cells (NSCs) derived from a neuronopathic GD model exhibited decreased ability for self-renewal and neuronal differentiation. Co-culture of GBA-deficient NSCs with BM-MSCs resulted in an enhanced capacity for self-renewal, and an increased ability for differentiation into neurons or oligodendrocytes. Enhanced proliferation and neuronal differentiation of GBA-deficient NSCs was associated with elevated release of macrophage colony-stimulating factor (M-CSF) from BM-MSCs. Our findings suggest that soluble M-CSF derived from BM-MSCs can modulate GBA-deficient NSCs, resulting in their improved proliferation and neuronal differentiation.     

Characteristics of stem cells derived from the degenerated human intervertebral disc cartilage endplate

Mesenchymal stem cells (MSCs) derived from adult tissues are an important candidate for cell-based therapies and regenerative medicine due to their multipotential differentiation capability. MSCs have been identified in many adult tissues but have not reported in the human intervertebral disc cartilage endplate (CEP). The initial purpose of this study was to determine whether MSCs exist in the degenerated human CEP. Next, the morphology, proliferation capacity, cell cycle, cell surface epitope profile and differentiation capacity of these CEP-derived stem cells (CESCs) were compared with bone-marrow MSCs (BM-MSCs). Lastly, whether CESCs are a suitable candidate for BM-MSCs was evaluated. Isolated cells from degenerated human CEP were seeded in an agarose suspension culture system to screen the proliferative cell clusters. Cell clusters were chosen and expanded in vitro and were compared with BM-MSCs derived from the same patient. The morphology, proliferation rate, cell cycle, immunophenotype and stem cell gene expression of the CESCs were similar to BM-MSCs. In addition, the CESCs could be induced into osteoblasts, adipocytes, chondrocytes, and are superior to BM-MSCs in terms of osteogenesis and chondrogenesis. This study is first to demonstrate the presence of stem cells in the human degenerated CEP. These results may improve our understanding of intervertebral disc (IVD) pathophysiology and the degeneration process, and could provide cell candidates for cell-based regenerative medicine and tissue engineering.     

Induction of decidual differentiation in endometrial mesenchymal stem cells

In this study, we compared the ability of human mesenchymal stem cells (eMSCs) derived from menstrual blood and mesenchymal stem cells (MSCs) from other tissues to differentiate into decidual cells in vitro. It was demonstrated that, during differentiation, secretion of prolactin and insulin-like growth factor binding protein-1 (key decidualization markers) markedly increased in eMSCs slightly augmented in bone marrow MSC (BM-MSCs) and did not change in MSCs from adipose tissue (AT-MSCs). Thus, eMSCs exhibited higher capacity for differentiation into decidual cells than BM-MSCs or AT-MSCs. This makes eMSCs promising for application in cellular therapy of infertility associated with insufficient decidualization of endometrium.     

Cell-autonomous heparanase modulates self-renewal and migration in bone marrow-derived mesenchymal stem cells

Background

Stem cell-fate is highly regulated by stem cell niche, which is composed of a distinct microenvironment, including neighboring cells, signals and extracellular matrix. Bone marrow-derived mesenchymal stem cells (BM-MSCs) are multipotent stem cells and are potentially applicable in wide variety of pathological conditions. However, the niche microenvironment for BM-MSCs maintenance has not been clearly characterized. Accumulating evidence indicated that heparan sulfate glycosaminoglycans (HS-GAGs) modulate the self-renewal and differentiation of BM-MSCs, while overexpression of heparanase (HPSE1) resulted in the change of histological profile of bone marrow. Here, we inhibited the enzymatic activity of cell-autonomous HPSE1 in BM-MSCs to clarify the physiological role of HPSE1 in BM-MSCs.

Results

Isolated mouse BM-MSCs express HPSE1 as indicated by the existence of its mRNA and protein, which includes latent form and enzymatically active HPSE1. During in vitro osteo-differentiations, although the expression levels of Hpse1 fluctuated, enzymatic inhibition did not affect osteogenic differentiation, which might due to increased expression level of matrix metalloproteinase 9 (Mmp9). However, cell proliferation and colony formation efficiency were decreased when HPSE1 was enzymatically inhibited. HPSE1 inhibition potentiated SDF-1/CXCR4 signaling axis and in turn augmented the migratory/anchoring behavior of BM-MSCs. We further demonstrated that inhibition of HPSE1 decreased the accumulation of acetylation marks on histone H4 lysine residues suggesting that HPSE1 also modulates the chromatin remodeling.

Conclusions

Our findings indicated cell-autonomous HPSE1 modulates clonogenicity, proliferative potential and migration of BM-MSCs and suggested the HS-GAGs may contribute to the niche microenvironment of BM-MSCs.     

Purified Human Synovium Mesenchymal Stem Cells as a Good Resource for Cartilage Regeneration

Mesenchymal stem cells (MSCs) have the ability to differentiate into a variety of lineages and to renew themselves without malignant changes, and thus hold potential for many clinical applications. However, it has not been well characterized how different the properties of MSCs are depending on the tissue source in which they resided. We previously reported a novel technique for the prospective MSC isolation from bone marrow, and revealed that a combination of cell surface markers (LNGFR and THY-1) allows the isolation of highly enriched MSC populations. In this study, we isolated LNGFR⁺ THY-1 ⁺ MSCs from synovium using flow cytometry. The results show that the synovium tissue contained a significantly larger percentage of LNGFR ⁺ THY-1 ⁺ MSCs. We examined the colony formation and differentiation abilities of bone marrow-derived MSCs (BM-MSCs) and synovium-derived MSCs (SYN-MSCs) isolated from the same patients. Both types of MSCs exhibited a marked propensity to differentiate into specific lineages. BM-MSCs were preferentially differentiated into bone, while in the SYN-MSC culture, enhanced adipogenic and chondrogenic differentiation was observed. These data suggest that the tissue from which MSCs are isolated should be tailored according to their intended clinical therapeutic application.     

Hypoxia Pretreatment of Bone Marrow Mesenchymal Stem Cells Facilitates Angiogenesis by Improving the Function of Endothelial Cells in Diabetic Rats with Lower Ischemia

Endothelial dysfunction induced by unordered metabolism results in vascular reconstruction challenges in diabetic lower limb ischemia (DLLI). Mesenchymal stem cells (MSCs) are multipotent secretory cells that are suitable for clinical DLLI treatment, but their use has been hampered by poor survival after injection. Hypoxia can significantly enhance the capacity of MSCs to secrete angiogenic factors. We investigated transient hypoxia pretreatment of MSCs to facilitate revascularization in DLLI. Rat bone marrow MSCs (BM-MSCs) were cultured at different oxygen concentrations for varying time periods. The results indicated that transient pretreatment (5% O₂, 48 h) not only increased the expression of VEGF-1α, ANG, HIF-1α and MMP-9 in BM-MSCs as assessed by real-time RT-PCR, but also increased the expression of Bcl-2 as determined by western blotting. The transplantation of pretreated BM-MSCs into rats with DLLI demonstrated accelerated vascular reconstruction when assayed by angiography and immunohistochemistry. CM-Dil-labeled tracer experiments indicated that the survival of BM-MSCs was significantly improved, with approximately 5% of the injected cells remaining alive at 14 days. The expression levels of VEGF-1α, MMP-9 and VEGF-R were significantly increased, and the expression of pAKT was up-regulated in ischemic muscle. Double immunofluorescence studies confirmed that the pretreated BM-MSCs promoted the proliferation and inhibited the apoptosis of endothelial cells. In vitro, pretreated BM-MSCs increased the migratory and tube forming capacity of endothelial cells (ECs). Hypoxia pretreatment of BM-MSCs significantly improved angiogenesis in response to tissue ischemia by ameliorating endothelial cell dysfunction and is a promising therapeutic treatment for DLLI.