Human adipose-derived mesenchymal stem cells: a better cell source for nervous system regeneration

Background In order to suggest an ideal source of adult stem cells for the treatment of nervous system diseases,MSCs from human adipose tissue and bone marrow were isolated and studied to explore the differences with regard to cell morphology,surface markers,neuronal differentiation capacity,especially the synapse structure formation and the secretion of neurotrophic factors.Methods The neuronal differentiation capacity of human mesenchymal stem cells from adipose tissue （hADSCs） and bone marrow （hBMSCs） was determined based on nissl body and synapse structure formation,and neural factor secretion function.hADSCs and hBMSCs were isolated and differentiated into neuron-like cells with rat brain-conditioned medium,a potentially rich source of neuronal differentiation promoting signals.Specific neuronal proteins and neural factors were detected by immunohistochemistry and enzyme-linked immunosorbent assay analysis,respectively.Results Flow cytometric analysis showed that both cell types had similar phenotypes.Cell growth curves showed that hADSCs proliferated more quickly than hBMSCs.Both kinds of cells were capable of osteogenic and adipogenic differentiation.The morphology of hADSCs and hBMSCs changed during neuronal differentiation and displayed neuronlike cell appearance after 14 days＇ differentiation.Both hADSCs and hBMSCs were able to differentiate into neuron-like cells based on their production of neuron specific proteins including β-tubulin-Ⅲ,neuron-specific enolase （NSE）,nissl bodies,and their ability to secrete brain derived neurotrophic factor （BDNF） and nerve growth factor （NGF）.Assessment of synaptop hysin and growth-associated protein-43 （GAP-43） suggested synapse structure formation in differentiated hADSCs and hBMSCs.Conclusions Our results demonstrate that hADSCs have neuronal differentiation potential similar to hBMSC,but with a higher proliferation capacity than hBMSC.Adipose tissue is abundant,easily available and would be a potential ideal source of adult stem cells for neural-related clinical research and application.     

Wild-type Smad3 Gene Enhances the Osteoblastic Differentiation of Rat Bone Marrow-derived Mesenchymal Stem Cells in Vitro

This study examined the effect of wild-type Smad3 gene on the osteoblastic differentiation of rat bone marrow-derived mesenchymal stem cells in vitro. Bone marrow-derived mesenchymal stem cells （MSCs） were stably transfected with the complexes of PeDNA3.0-Myc-Smad3 or PeDNA3.0- Mye-Smad3△C and Lipofectamine reagent. Immunofluorescence staining was performed to evaluate the c- Myc signal in MSCs. The cell proliferation was detected by MTT method. To clarify the osteoblastic characteristics in stably transfected MSCs, alkaline phosphatase （ALP） mRNA and core binding factor α1 （Cbfal） mRNA were investigated by RT-PCR, and ALP activity and mineralization were examined by p-nitrophenolphosphate method and alizarin red staining respectively. PD98059, a specific inhibitor of the ERK signaling pathway, was used to determine the role of ERK in Smad3MSCs osteoblastic differentiation, c-Myc signal was detected in Smad3-MSCs and Smad3△C- MSCs. The proliferation of Smad3-MSCs was slower than that of Smad3/△C-MSCs or V-MSCs. The relative levels of ALP mRNA and Chfal mRNA in Smad3-MSCs, as well as ALP activity and mineralization, were markedly higher than those in Smad3/△C-MSCs or V-MSCs. Although ALP activity and mineralization were slightly lower in Smad3-MSCs.treated with PD98059 than in those without PD98059 treatment, no significant difference was found between them （P〉0.05）. It is concluded that the wild-type Smad3 gene, which is a crucial component promoting bone formation, can inhibit the proliferation of MSCs and enhance the osteoblastic differentiation of uncommitted MSCs and the maturation of committed MSCs independent of the ERK signaling pathway.     

Osteogenic Differentition of Adipose-derived Stem Cells Isolated from Rabbit Subcutaneous Adipose Tissue

Objective To fully evaluate the osteogenic potential of adipose-derived stem cells （ADSCs） isolated from rabbit subcutaneous adipose tissue. Methods Rabbit ADSCs （rADSCs） were prepared by collagenase I digestion of subcutaneous fat from the suprascapular site of Japanese white rabbit after being excised and finely minced. Meanwhile, the bone marrow stem cells （BMSCs） were isolated from the ventral ilium by bone marrow aspiration from the same rabbit as control. The in vitro cell proliferation of rADSCs and rabbit BMSCs （rBMSCs） were firstly examined. After which, the osteogenic differentiation of rADSCs and rBMSCs were identified by von Kossa staining after cultured under osteogenic medium for 28 days. During the osteogenic differentiation process, the alkaline phosphatase （ALPase） activity and extracellular matrix mineralization of rADSCs was analyzed quantitatively compared with the rBMSCs. Results The in-vitro cultured rADSCs assumed similar fibroblast-like morphology similar to rBMSCs, but have a higher proliferation rate. The von Kossa staining indicated that calcium nodules were formed in both rADSCs and rBMSCs after having been induced under osteogenic medium for 28 days. Furthermore, quantitative analyses of ALPase and extracellular matrix mineralization implied that the rADSCs have a favorable osteogenic potency similar to that of rBMSCs. Conclusion The rADSCs have excellent osteogenic differentiation capacity and can be used as seed cells in bone tissue engineering so as to provide valuable data for the potential application of human ADSCs in clinical area.     

Human Adipose-derived Mesenchymal Stem Cells: A Better Cell Source for Nervous System Diseases Application

In order to suggest an ideal source of adult stem cells for treatment of nervous system diseases, neuronal differentiation capacity of human mesenchymal stem cells from adipose tissue (hADSCs) and bone marrow (hBMSCs) were studied in terms of nissl body and synapse structure formation, neural factors secretion function for the first time. The hADSCs and hBMSCs were isolated and differentiated to the neuron-like cells with rat brain-conditioned medium which is potentially a rich source of signals promoting neuronal differentiation. The specific proteins of neurons and neural factors secreted by the cells were detected with immunohistochemistry and ELISA analysis, respectively. Flow cytometric analysis showed that these cells had similar phenotypes and cell growth curves showed that hADSCs proliferated more quickly than hBMSCs. Both kinds of cells were capable of osteogenic and adipogenic differentiation. The morphology of hADSCs and hBMSCs changed during neuronal differentiation and presented neuron-like cell appearance after 14 days differentiation. hADSCs and hBMSCs could differentiated into neuronal-like cells, which were identified by neuron specific proteins: β-Tubulin-Ш, neuron-specific enolase (NSE), and nissl body and their ability to secrete brain derived neurophic factor (BDNF) and nerve growth factor (NGF). Assessment of synaptophysin and growth-associated protein-43 (GAP-43) suggested synapse structure formation in differentiated hADSCs and hBMSCs. The present results demonstrated that hADSCs have a similar neuronal differentiation potential with hBMSCs but with higher proliferation capacity. Adipose tissue is an abundant and easily available, which would be a potential ideal source of adult stem cells for neural-related clinical research and application.     

Bone morphogenetic protein 2 promotes transforming growth factor β3-induced chondrogenesis of human osteoarthritic synovium-derived stem cells

Background Synovium-derived stem cells （SDSCs） with higher chondrogenic potential are attracting considerable attention as a cell source for cartilage regeneration. We investigated the effect of bone morphogenetic protein 2 （BMP-2） on transforming growth factor beta3 （TGF-β3）-induced chondrogenesis of SDSCs isolated from human osteoarthritic synovium in a pellet culture system. Methods The clonogenicity, stem cell marker expression and multi-differentiation potential of isolated SDSCs were determined by colony forming unit assay, flow cytometry and specific staining including alizarin red S, Oil red O and alcian blue staining, respectively. SDSCs pellet was cultured in chondrogenic medium with or without TGF-β3 or/and BMP-2. At day 21, the diameter and the weight of the pellets were measured. Chondrogenic differentiation of SDSCs was evaluated by Safranin O staining, immunohistochemical staining of collagen type Ⅱ, sulfated glycosaminoglycan （sGAG） synthesis and mRNA expression of collagen type Ⅱ, aggrecan, SOX9, link-protein, collagen type X and BMP receptor Ⅱ. Results Cells isolated under the optimized culturing density （104/60 cm2） showed clonogenicity and multi-differentiation potential. These cells were positive （〉99%） for CD44, CD90, CD105 and negative （〈10%） for CD34 and CD71. SDSCs differentiated to a chondrocytic phenotype in chondrogenic medium containing TGF-β3 with or without BMP-2. Safranin O staining of the extracellular matrix was positive and the expression of collagen type Ⅱ was detected. Cell pellets treated with TGF-β3 and BMP-2 were larger in diameter and weight, produced more sGAGs, and expressed higher levels of collagen type Ⅱ and other chondrogenic markers, except COL10A1, than medium with TGF-β3 alone. Conclusions SDSCs could be isolated from human osteoarthritic synovium. Supplementation with BMP-2 significantly promoted the in vitro TGF-β3-induced chondrogenic differentiation of SDSCs.     

COA: Bone Morphogenetic Protein 2 Promoted Transforming Growth Factor β3 Induced Chondrogenesis of Human Osteoarthritic Synovium-Derived Stem Cells

Background Synovium-derived stem cells (SDSCs) with greater chondrogenic potential are attracting more considerable attention as a cell source for cartilage regeneration. The aim of this study was to investigate the effect of bone morphogenetic protein-2 (BMP-2) on transforming growth factor-beta3 (TGF-β3)-induced chondrogenesis of SDSCs isolated from human osteoarthritic synovium in a pellet culture system. Methods Nucleated cells isolated from human osteoarthritic synovium were plated at an optimal cell density to allow the selective proliferation of SDSCs. The clonogenicity, stem cell marker expression and multi-differentiation potential were determined by CFU assay, flow cytometry assay and specific staining including alizarin red S staining, Oil red staining and alcian blue staining, respectively. SDSCs pellet was cultured in chondrogenic medium without or with TGF-β3 or/and BMP-2. At day 21, the diameter and the weight of the pellets were measured. Chondrogenic differentiation of SDSCs was evaluated by Safranin O staining, immunohistochemical staining of collagen type II, sulfated glycosaminoglycan (sGAG) synthesis and mRNA expression of collagen type II (COL2A1), aggrecan (ACAN), SOX9, link-protein (HAPLN1), collagen type X (COL10A1) and BMP receptor II (BMPR-II). Results Cells isolated under the optimized culturing density (104/60cm2) showed clonogenicity and multi-differentiation potential. These cells were positive (>99% positive) for CD44, CD90, CD105 and negative (<10% positive) for CD34 and CD71. SDSCs differentiated to a chondrocytic phenotype in chondrogenic medium containing TGF-β3 with or without BMP-2. Metachromatic staining of the extracellular matrix with Safarnin O was positive and the expression of collagen type II was detected. The combination of TGF-β3 and BMP-2 produced cell pellets with larger diameter and weight, produced more sGAGs, expression higher levels of collagen type II and chondrogenic markers, except COL10A1, than medium with TGF-β3 alone. Conclusions SDSCs could be isolated from human osteoarthritic synovium. Supplementation of BMP-2 significantly promoted the in vitro TGF-β3-induced chondrogenic differentiation of SDSCs.     

Chondrogenic Differentiation of Mouse Bone Marrow Mesenchymal Stem Cells Induced by Cartilage-derived Morphogenetic Protein-2 In Vitro

To study the cartilage differentiation of mouse mesenchymal stem cells （MSCs） induced by cartilage-derived morphogenetic proteins-2 in vitro, the MSCs were isolated from mouse bone marrow and cultured in vitro. The cells in passage 3 were induced into chondrogenic differentiation with different concentrations of recombinant human cartilage-derived morphogenetic proteins-2 （0, 10, 20, 50 and 100 ng/mL）. After 14 days of induction, morphology of cells was observed under phase-contrast microscope. Collagen Ⅱ mRNA and protein were examined with RT-PCR, Western blotting and immunocytochemistry respectively and the sulfate glycosaminoglycan was measured by Alcian blue staining. RT-PCR showed that CDMP-2 could promote expression of collagen Ⅱ mRNA in an dose-dependant manner, especially at the concentration of 50 ng/mL and 100 ng/mL. Immunocytochemistry and Western blotting revealed a similar change. Alcian blue staining exhibited deposition of typical cartilage extracellular matrix. Our results suggest that mouse bone marrow mesencymal stem cells can differentiate into chondrogenic phonotype with the induction of CDMP-2 in vitro, which provides a basis for further research on the role of CDMP-2 in chondrogenesis.     

Influence of bone morphogenetic proteins-2 and strontium chloride on the human umbilical cord mesenchymal stem cells proliferation and osteogenic differentiation

<正>Objective To study the effects of combination of bone morphogenetic protein-2 (BMP-2) and strontium chloride on proliferation and osteogenic differentiation of human umbilical cord mesenchymal stem cells(hUCM-SCs)in vitro culture.     

Osteogenic differentiation of bone mesenchymal stem cells regulated by osteoblasts under EMF exposure in a co-culture system

This study examined the osteogenic effect of electromagnetic fields （EMF） under the simulated in vivo conditions. Rat bone marrow mesenchymal stem cells （BMSCs） and rat osteoblasts were co-cultured and exposed to 50 Hz, 1.0 mT EMF for different terms. Unexposed single-cultured BMSCs and osteoblasts were set as controls. Cell proliferation features of single-cultured BMSCs and osteoblasts were studied by using a cell counting kit （CCK-8）. For the co-culture system, cells in each group were randomly chosen for alkaline phosphatase （ALP） staining on the day 7. When EMF exposure lasted for 14 days, dishes in each group were randomly chosen for total RNA extraction and von Kossa staining. The mRNA expression of osteogenic markers was detected by using real-time PCR. Our study showed that short-term EMF exposure （2 h/day） could obviously promote prolifera- tion of BMSCs and osteoblasts, while long-term EMF （8 h/day） could promote osteogenic differen- tiation significantly under co-cultured conditions. Under EMF exposure, osteogenesis-related mRNA expression changed obviously in co-cultured and single-cultured cells. It was noteworthy that most osteogenic indices in osteoblasts were increased markedly after co-culture except Bmp2, which was increased gradually when ceils were exposed to EMF. Compared to other indices, the expression of Bmp2 in BMSCs was increased sharply in both single-cultured and co-cultured groups when they were exposed to EMF. The mRNA expression of Bmp2 in BMSCs was approximately four times higher in 8-h EMF group than that in the unexposed group. Our results suggest that Bmp2-mediated cellular interaction induced by EMF exposure might play an important role in the osteogenic differ- entiation of BMSCs.     

Dexamethasone-induced adipogenesis in primary marrow stromal cell cultures: mechanism of steroid-induced osteonecrosis

Background In steroid-induced osteonecrosis, hypertrophy and hyperplasia of marrow fat cells and lipid deposition of osteocytes can be found in the femoral head. However, the precise reason is not clear yet. The aim of this study was to observe the effect of dexamethasone （Dex） on differentiation of marrow stromal cells （MSCs）, and to investigate the pathobiological mechanism of steroid-induced osteonecrosis. Methods MSCs in cultures were treated with increasing concentrations of Dex （0, 10^-9, 10^-8, 10^-7, and 10^-6 mol/L） continuously for 21 days. The cells, which were exposed to 0 mol/L （control） or 10^-7 mol/L Dex for 4-21 days, were then cultured for 21 days without Dex. MSCs were stained with Sudan Ⅲ. Number of adipocytes was counted under a light microscope. The activity of alkaline phosphatase （ALP） of MSCs treated with 0, 10^-8, 10-7, and 10^-6 mol/L Dex for 12 days, and that treated with 0 mol/L and 10^-7 mol/L Dex for 8, 10, or 12 days were determined. The levels of triglycerides, osteocalcin and cell proliferation of MSCs treated with 0 mol/L and 10^-7 mol/L Dex were detected. The mRNA expression levels of adipose-specific 422（aP2） gene and osteogenic gene type I collagen in MSCs treated with 0 mol/L and 10^-7 mol/L Dex for 6 days were analyzed by whole-cell dot-blot hybridization. Statistical analysis was performed using Student＇s t test and analysis of variance. P values less than 0.05 were considered significant statistically. Results The number of adipocytes in cultures increased with the duration of MSCs＇ exposure to Dex and the concentration of Dex. The level of ALP activity in the MSCs decreased with concentration of Dex. In the control group, it was 8.69 times of that in the 10^-7 mol/L Dex group on day 12 （t=20.51, P〈0.001）. The level of triglycerides in 10^-7 mol/L Dex group was 3.40 times of that in the control （t=11.00, P〈0.001）. The levels of cell proliferation and osteocalcin in the control were 1.54 and 2.42 times of that in the 10^-7 mol/L Dex group respectively. As compared to the control, the mRNA expression of adipose-specific 422（aP2） gene in 10^-7mol/L Dex group was significantly increased （t=36.48, P〈0.001）, and that of osteogenic gene type I collagen was decreased （t=42.07, P〈0.001）. Conclusions Dex can directly induce the differentiation of MSCs into a large number of adipocytes and inhibit their osteogenic differentiation, which provide a novel explanation for the pathologic changes of steroid-induced osteonecrosis.     

Dopamine inhibits proliferation, induces differentiation and apoptosis of K562 leukaemia cells

Background Dopamine exerts its effects mainly in nervous system through D1, D2 or D3 receptors. There are few reports dealing with the effects of dopamine on leukaemia cells. However, some dopamine agonists or antagonists do show biological effects on some types of leukaemia cells. Here, we report the effects of dopamine on the proliferation, differentiation and apoptosis of K562 leukaemia cells.Methods Proliferation was determined by MTT assay and cell counting both in liquid and semisolid cultures. Differentiation was verified by morphology, benzidine staining and flow cytometry. Apoptosis was checked by Hoechst 33258 staining and flow cytometry. The two groups were untreated group and treated group (dopamine 10(-9) mol/L―10(-4) mol/L).Results In liquid culture, MTT assay and colony assay, dopamine inhibited proliferation of K562 cells. Inhibition rate was 29.28% at 10(-6) mol/L and 36.10% at 10(-5) mol/L after culture for 5 days in MTT assay. In benzidine staining and CD71 expression, dopamine induced K562 cells toward erythroid differentiation by increased 155% at 10(-6) mol/L and by 171% at 10(-5) mol/L after culture for 5 days in benzidine staining. In Hoechst 33258 staining and flow cytometry, dopamine induced K562 cells toward apoptosis. The sub G1 peak stained by PI was 14.23% at 10(-4) mol/L dopamine after culture for 3 days compared with the control (0.81%) in flow cytometry.Conclusion Dopamine inhibites proliferation and induces both differentiation and apoptosis of K562 leukaemia cells.     

Retroviral-mediated transfer and functional expression of multidrug resistance gene in human placenta mesenchymal stem cells

Background Most of gynecologic malignancies are sensitive to chemotherapy. Myelosuppression is the main dose-related toxicity of many chemotherapeutic drugs. The human multidrug resistance （mdrl） gene is well known for its ability to confer drug resistance. This study aimed to explore the feasibility of expression and resistance of mdrl gene transduction into human placenta mesenchymal stem cells （P-MSCs） by retrovirus vector. Methods Human P-MSCs were isolated from trypsin-digested term placentas, and their immunophenotypes and differentiation potential were evaluated. Human P-MSCs were transduced by reconstructed retroviral vector containing the mdrl gene and green fluorescent protein （GFP） reporter gene. The integration and expression of the mdrl gene were observed indirectly by the expression of GFP, and fluorescence-activated cell sorter was used to evaluate the functional activity of permeability glycoprotein （P-gp） encoded by the mdrl gene. The stimulating test was made in vitro to show pleiotropic drug resistance of transfected cells. Results The isolated, cultured and expanded P-MSCs expressed stem cell markers such as CD29, CD44 and CD73, and showed osteogenic and adipogenic differentiation potentials under appropriate conditions. The expression of P-gp in the non-transfected P-MSCs cells was （0.4±0.1）%, but increased to （28.1±4.7）% after gene transfection （P〈0.01）. And positive staining of P-gp located mainly at cell membrane and cytoplasm. Accumulation and extrusion assays showed that P-gp expressed by the transfected cells had pump-functional activity and could efflux daunomycin out of cells. The analysis of cell survival confirmed that transfected P-MSCs had a characteristic of multidrug resistance with a significant increase in the resistance to anticancer agents. Conclusions Transfer and expression of human mdrl gene mediated by retrovirus vector conferred P-MSCs drug resistance. It might provide a new alternative to chemoprotection strategies.     

Inducing effects of macrophage stimulating protein on the expansion of early hematopoietic progenitor cells in liquid culture

Background Macrophage stimulating protein （MSP） is produced by human bone marrow endothelial cells. In this study we sought to observe its effects on inducing the expansion of early hematopoietic progenitor cells which were cultured in a liquid culture system in the presence of the combination of stem cell factor （SCF）, interleukin 3 （IL-3）, interleukin 6 （IL-6）, granulocyte macrophage-colony stimulating factor （GM-CSF）, erythropoietin （EPO） （Cys） and MSP or of Cys and bone marrow endothelial cell conditioned medium （EC-CM）. Methods Human bone marrow CD34^＋ cells were separated and cultured in a liquid culture system for 6 days. Granulocyte-macrophage colony forming unit （CFU-GM） and colony forming unit-granulocyte, erythrocyte, macrophage, megakaryocyte （CFU-GEMM） were employed to assay the effects of different treatment on the proliferation of hematopoeitic stem/progenitor cells. The nitroblue tetrazolium （NBT） reductive test and hoechest 33258 staining were employed to reflect the differentiation and apoptosis of the cells respectively. Results MSP inhibited the proliferation of CFU-GM and CFU-GEMM in semi-solid culture and the inhibitory effect on CFU-GEMM was stronger than on CFU-GM. MSP inhibited the differentiation of early hematopoietic progenitor cells induced by hematopoietic stimulators. Bone marrow （BM） CFU-GEMM was 2.3-fold or 1.7-fold increase or significantly decreased in either Cys＋EC-CM, Cys＋MSP or Cys compared with 0 hour control in liquid culture system after 6 days. Conclusion MSP, a hematopoietic inhibitor, inhibits the differentiation of early hematopoietic progenitor cells induced by hematopoietic stimulators and makes the early hematopoietic progenitor cells expand in a liquid culture system.