Rabbit bone marrow-derived mesenchymal stem cells(MSCs) are multipotent. We studied the adipogenic and osteogenic differentiation potent using adipogenic supplement (AS) or osteogenic supplement (OS) in vitro. Specific markers of this induced adipogenic and osteogenic lineage were identified. The findings showed that the rabbit MSCs are capable of differentiating into adipogenic and osteogenic lineages spontaneously. On the 21st day, approximately 75% rabbit MSCs were induced to adipogenic or osteogenic cells in medium containing AS or OS, respectively. These results demonstrated that the differentiation of MSCs could be regulated in vitro. The underlying molecular mechanisms of adipogenic or osteogenic differentiation await elucidation.
Adipose Tissue ; cytology ; Animals ; Bone and Bones ; cytology ; Cell Differentiation ; Cell Lineage ; In Vitro Techniques ; Mesoderm ; cytology ; Rabbits ; Stem Cells ; cytology

OBJECTIVETo study the gene expression profiles of human bone marrow derived mesenchymal stem cells and tendon cells.

METHODSTotal RNA extracted from human bone marrow derived mesenchymal stem cells and tendon cells underwent reverse transcription, and the products were labeled with alpha-(32)P dCTP. The cDNA probes of total RNA were hybridized to cDNA microarray with 1176 genes, and then the signals were analyzed by Atlas Image analysis software Version 1.01a.

RESULTSFifteen genes associated with cell proliferation and signal transduction were up-regulated, and one gene that takes part in cell-to-cell adhesion was down-regulated in tendon cells.

CONCLUSIONThe 15 up-regulated and one down-regulated genes may be beneficial to the orientational differentiation of mesenchymal stem cells into tendon cells.

Bone Marrow Cells ; Gene Expression Profiling ; Humans ; Mesoderm ; cytology ; Stem Cells ; Tendons ; cytology

The basic studies selected were mainly published since 1998 and related to stem cell biology and engineering and particularly the efforts for developing new sources of hematopoietic stem/progenitor cells ex vivo. Hematopoietic cells and lymphocytes can be developed by induced differentiation in a appropriate way of culture, originating in the embryo- or adult-derived stem cells or tissue-committed stem cells which still exist in the tissue of adults. The most primitive multipotential embryonic stem cell from embryo or adult tissue has the plasticity to differentiate into every kind of progenies, the committed tissue-specific stem cell, by different proper ways of induction in vitro. The committed tissue-specific stem cell, however, can only be induced to differentiate along the line of its committed origin of tissue. No studies in China strongly confirmed yet the existence of "transdifferentiation" among the tissue- or organ-specific stem cells.
Adult ; Cell Differentiation ; Cell Lineage ; China ; Embryo, Mammalian ; cytology ; Hematopoietic Stem Cells ; cytology ; Humans ; Mesoderm ; cytology ; Models, Biological ; Pluripotent Stem Cells ; cytology ; Research ; trends ; Stem Cells ; cytology

OBJECTIVETo isolate and identify the phenotype and biological characteristics of pancreas derived mesenchymal stem cell.

METHODSFresh pancreas of 4-5 months old aborted fetus was dissected free from connective tissue, and was cut into small pieces. The adherent cells were harvested and subcultured, after the third subculture, the cells were used for examination. Cell cycle was analyzed by measuring DNA content by FACScan flow cytometer. Phenotype of MSCs was analyzed by immunohistochemical SA technique and differentiated cells were identified by relevant specific staining.

RESULTSFetal pancreas derived cells gave rise to a population of adherent cells characterized by the presence of a predominant cell type with a typical fibroblast like morphology. By transmission electron microcopy, MSC had few endoplasmic reticulums and mitochondrias. During the log phase of growth, MSC proliferated with a two fold population at 30 h. MSC can be ex vivo expanded by successive cycles of trypsinization, seeding, and culture. Under these conditions, MSC had capability of passaging up to 30 times without displaying significant changes in morphology, with 2-fold increase in cell number after each passage. This indicates the high ex vivo expansion potential of MSC. The results showed that the yield of CFU-Fs was above 200 clones even after the 6th passage. Cell cycle analysis by flow cytometry revealed that more than 83% of cells were in the G0/G1 phases, while a small population of cells were actively engaged in proliferation (S + G2 + M = 17%). We also showed that more than 86% of cells were positive stained by FITC labeled CD44, CD29, CD13, and only about 1% of cells were positive for CD34, HLA-DR. Expression of collagen I, III was positive while vWF was negative. In the differentiation study, we found culture-expanded pancreas MSCs could be directed into the osteogenic lineage as detected by osteoblastic morphology, expression of alkaline phosphatase, modulation of osteocalcin mRNA production and the formation of a mineralized extracellular matrix. We also found that MSCs could give rise to the adipogenic and chondrogenic lineage as evidenced by accumulation of lipid-rich vacuoles within cells and the expression of lipoprotein lipase mRNA or the expression of collagen II and the deposition of proteoglycans.

CONCLUSIONMesenchymal stem cells existing in human pancreas can be isolated by their adherent ability and should be essential to sustain a steady supply of primitive cells in tissue remodeling.

Cell Differentiation ; Cell Division ; Cell Separation ; Cells, Cultured ; Colony-Forming Units Assay ; Fetus ; Fibroblasts ; cytology ; Humans ; Mesoderm ; cytology ; Osteogenesis ; Pancreas ; cytology ; Phenotype ; Stem Cells ; cytology

OBJECTIVETo investigate the potential of yolk sac mesenchymal stem cells in osteogenic differentiation.

METHODSMurine yolk sacs were harvested on day 8.5 postcoitus, yolk sac cells were obtained after the yolk sacs were digested by 0.1% type I collagenase for 1 hour, the non-adherent cells were removed after being cultured for 1 hour. The adherent cells were cultured in DMEM containing of 5 ng/ml bFGF and 15% FBS, and passaged when they became subconfluent. The morphologic characteristics, and AKP, BMP-2, as well as type I, III collagen of the yolk sac adherent cells were observed and tested. The attached cells were treated with 10(-8) mol/L dexamethasone, 10 mmol/L beta-glycerophosphate, and 50 micrograms/ml vitamin C at passage 4. Alternations of morphological characteristic, AKP activity, collagen of type I, III and mineralization were detected.

RESULTSPure mesenchymal stem cells which were of spindle shape, uniform in size, positive in type I, III collagen staining and weak positive in AKP activity could be induced to pleomorphism osteoblast-like cells in vitro. The cells were transformed from spindle shape to polygonal cells which were positive in type I collagen, negative in type III collagen, strong positive in BMP-2, and positive in Von Kossa's stain at week 8. The polygonal cells could form nodular structure and their AKP activity was increased. All these were coincidence with the characters of osteoblast.

CONCLUSIONYolk sac mesenchymal stem cell can be purified and induced to osteoblast in vitro.

Alkaline Phosphatase ; biosynthesis ; Animals ; Bone Morphogenetic Proteins ; biosynthesis ; Cell Differentiation ; Cells, Cultured ; Female ; Mesoderm ; cytology ; Mice ; Osteoblasts ; cytology ; Osteogenesis ; Stem Cells ; cytology ; Yolk Sac ; cytology

OBJECTIVETo explore the immunoregulatory effects of human amniotic mesenchymal cells (hAMCs) on allogeneic peripheral blood lymphocytes.

METHODSThe hAMCs were isolated from abandoned human amnion. Peripheral blood mononuclear lymphocytes (PBMLs) were separated from healthy donors by density gradient centrifugation. Then, PBMLs were treated with phytohemagglutinin (PHA) and different concentrations of hAMCs. Proliferation effect of PBMLs was tested using MTS assay, and production of IFN-gamma and TNF-alpha by PBMLs was detected by ELISA.

RESULTShAMCs could remarkably inhibit the lymphocytes proliferation. When the ratios of hAMCs to PBMLs were 0.05: 1, 0.10 :1, 0.20: 1, the inhibitory rates of PBMLs proliferation were 16.91%, 20.83% and 28.19%, respectively. HAMCs also decreased the production of IFN-gamma and TNF-alpha by PBMLs in a dose-dependent manner (P<0.01).

CONCLUSIONSHAMCs could inhibit the proliferation of allogeneic lymphocytes and reduce secretion of IFN-gamma and TNF-alpha, which might be one of the mechanism for prevention and remission of transplant rejection.

Amnion ; cytology ; Cell Proliferation ; Humans ; Immune Tolerance ; Interferon-gamma ; biosynthesis ; Lymphocyte Activation ; immunology ; Lymphocytes ; cytology ; drug effects ; immunology ; Mesoderm ; cytology ; Phytohemagglutinins ; immunology ; Tumor Necrosis Factor-alpha ; biosynthesis

OBJECTIVETo study the relationship between the morphologic mechanism of human embryonic epidermic cells and mesenchymal-epithelial transformation (MET) and its modulation factor.

METHODSMorphological occurrence of epidermis was detected with histologic methods in earlier period [estimated gestational age (EGA) 6-14 weeks] human embryonic skin samples. At the same time, the characteristic expression and their distribution markers of mesenchymal cells [vimentin and alpha-smooth muscle actin (alpha-SMA)], embryonic specific epidermic protein CK8&18, specific protein of epidermic stem cell CK19, transforming growth factor-beta1) (TGF-beta1) and its receptor (TGFbetaRI) in embryonic epidermis were examined with immunohistochemistry and indirect-immunofluorescent doble-labelling method.

RESULTSDuring EAG 6-8 weeks, ectodermal cells containing Vim+/alpha-SMA(-) were found to transform into epidermal stem cells with CK8&18+/CK19+. In ectodermal cells, protein expression density of TGFbetaRI was moderate (+ +), while positive signal of TGFbeta1 was weak (+/-). After EGA10 weeks, epidermal cells showed typical morphological characteristics.

CONCLUSIONSAt EGA 6-8 weeks, human embryonic skin epidermal cells began to form through MET, in which the signal pathway mediated by TGFbetaRI might play important roles, but the role of TGFbeta1 need to be further studied.

Cell Differentiation ; physiology ; Epidermis ; cytology ; embryology ; Epithelial Cells ; cytology ; Humans ; In Vitro Techniques ; Mesoderm ; cytology ; Receptors, Transforming Growth Factor beta ; metabolism ; Transforming Growth Factor beta1 ; metabolism

UNLABELLEDTo identify differentially expressed genes between fetal mesenchymal stem cell (MSC) and adult MSC, especially specified genes expressed in fetal MSC, a cDNA subtractive library of fetal MSC was constructed using suppression subtractive hybridization (SSH) technique. At first, total RNA was isolated from fetal and adult MSC. Using SMART PCR synthesis method, single-strand and double-strand cDNAs were synthesized. After Rsa I digestion, fetal MSC cDNAs were divided into two groups and ligated to adaptor 1 and adaptor 2 respectively. Results showed that the amplified library contains 890 clones. Analysis of 890 clones with PCR demonstrated that 768 clones were positive. The positive rate is 86.3%. The size of inserted fragments in these positive clones was between 0.2 - 1 kb, with an average of 400 - 600 bp.

CONCLUSIONSSH is a convenient and effective method for screening differentially expressed genes. The constructed cDNA subtractive library of fetal MSC cDNA lays solid foundation for screening and cloning new and specific function related genes of fetal MSC.

Cloning, Molecular ; DNA, Complementary ; genetics ; metabolism ; Deoxyribonucleases, Type II Site-Specific ; metabolism ; Fetus ; Gene Library ; Humans ; Mesoderm ; cytology ; metabolism ; Polymerase Chain Reaction ; Stem Cells ; cytology ; metabolism

OBJECTIVETo study the characteristics of dermal mesenchymal stem cells (DMSC), and explore whether they could enhance hematopoiesis recovery in vivo as well as facilitate proliferation and differentiation of hematopoietic cells in vitro.

METHODSMultipotential stem cells from the murine dermal mesenchyme were dissociated and cultured as donor cells. After 2 approximately 3 passages, the growth status, cell cycle, immunophenotype and morphology of DMSC were analyzed. Hematopoietic cells were plated onto a feeder layer formed by DMSC, cell count and CFU-GM yields were observed dynamically. Female mice received 5 Gy (137)Cs radiation were injected with DMSC cultured for 2 - 3 passages via tail vein. Cell count and CFU-GM yields of the bone marrow were observed regularly. Pathological study of the liver, spleen and bone marrow was done to evaluate hematopoiesis recovery.

RESULTSMurine DMSC are adherent cells with a morphology of fibroblastoid and spindle and multiangle in shape. Immunophenotypes showed that CD(45), CD(34), HL-DR positive DMSC were 1 - 3%, CD(44) and CD(13) positive DMSC 75 approximately 95%. Cell cycle assay demonstrated 83% of DMSC being G(0)/G(1) phase. In vitro, the total cell count and CFU-GM yields in the experimental group were higher than those of the long-term culture bone marrow cells by the third week. The DMSC can sufficiently support the proliferation and differentiation of hematopoietic cells for seven weeks. In vivo, peripheral granulocytic count, cells in the bone marrow of one femoral bone and CFU-GM by the third week in the experimental group were much higher than those of controls. Genetic assay of the murine blood demonstrated Y chromosome.

CONCLUSIONThe DMSC have characteristics of stem cells. DMSC sped up hematopoiesis recovery of irradiated mice. DMSC as a feeder layer can support proliferation and differentiation of hematopoietic cells.

Animals ; Bone Marrow Transplantation ; Female ; Hematopoiesis ; Immunophenotyping ; Male ; Mesoderm ; cytology ; Mice ; Mice, Inbred BALB C ; Skin ; cytology ; Stem Cell Transplantation ; Stem Cells ; physiology

Objective To induce adipose-derived stem cells (ADSCs) to differentiate into intermediate mesoderm (IM)-like cells ,with IM-like cells for recellularizing kidney scaffolds,and then to obtain a tissue-engineering kidney with renal structures and functions through co-culture.Methods After inguinal fat pads of Wistar rats were surgically harvested,the primary ADSCs were isolated,induced,and cultured for stem cell identification. ADSCs were inducted to differentiate into IM-like cells by adding glycogen synthase kinase-3 inhibitor (CHIR99021) and fibroblast growth factor 9 (FGF9) at different stages. Seven days later,the IM-like cells were identified. The induced IM-like cells and well-prepared kidney decellularized scaffolds were co-cultured for 10 days to obtain recellularized tissue-engineered kidneys and their differentiation was identified.Results The ADSCs harvested had osteogenic and adipogenic abilities and could express the stem cell surface markers. After 7 days of induction,the positive expressions of odd-skipped related 1 and paired-box 2 were observed in IM-like cells by immunofluorescence technique. After 10 days of co-culture with kidney decellularized scaffolds,the positive expressions of Wilms'tumor 1,GATA-binding protein-3,and E-cadherin were observed by immunofluorescence technique.Conclusion ADSCs can be induced into IM-like cells,and renal cell differentiation can be observed through combining the induced IM-like cells with kidney decellularized scaffolds.
Adipose Tissue ; Animals ; Cell Differentiation ; Cells, Cultured ; Kidney ; growth & development ; Mesoderm ; cytology ; Rats ; Rats, Wistar ; Regeneration ; Stem Cells ; cytology ; Tissue Engineering ; Tissue Scaffolds