Notch signaling is highly conserved in evolution and regarded as a key factor in cell fate determination. It mediates cell-to-cell interactions that are critical for embryonic development and tissue renewal, and is involved in the occurrence and metastasis of neoplasm. Recent researches have found that such signaling plays an important role in modulating the differentiation of chondrocytes, osteoblasts and osteoclasts. Dysfunction of Notch signaling can result in many skeletal diseases such as bone tumor, disorders of bone development or bone metabolism.
Animals ; Bone Development ; Bone Diseases ; genetics ; metabolism ; Bone and Bones ; metabolism ; Humans ; Osteoblasts ; cytology ; metabolism ; Osteogenesis ; Receptors, Notch ; genetics ; metabolism ; Signal Transduction

Animals ; Bone and Bones ; cytology ; metabolism ; pathology ; Collagen ; metabolism ; Durapatite ; metabolism ; Female ; Osteoporosis ; metabolism ; pathology ; Ovariectomy ; adverse effects ; Rats ; Rats, Sprague-Dawley

OBJECTIVEPolyethylene glycol/bone morphogenetic protein-2 (PEG/BMP-2) nanoparticles were transfected into Rabbit bone mesenchymal stem cells (rBMSCs) and the expression of BMP-2 was detected.

METHODSDissociated rBMSCs were primarily cultured in vitro and BMP-2 gene was transfected into rBMSCs by PEG/BMP-2 nanoparticals and lipofectamine, respectively. The efficiency of transfection was detected by flow cytometry and the expression of BMP-2 was detected by Western Blot and real time RT-PCR.

RESULTSPEG/BMP-2 nanoparticals were successfully synthesized and transfected into rBMSCs. Compared with the lipofectamine transfection group, PEG/BMP-2 transfection group had higher efficiency and higher BMP-2 expression.

CONCLUSIONPEG/BMP-2 nanoparticals transfected rBMSCs highly expressed BMP-2,which provided novel strategies for the treatment of bone defect.

Animals ; Bone Diseases ; genetics ; therapy ; Bone Morphogenetic Protein 2 ; chemistry ; genetics ; metabolism ; Bone and Bones ; cytology ; Gene Expression Regulation ; Humans ; Mesenchymal Stromal Cells ; cytology ; metabolism ; Nanoparticles ; chemistry ; Polyethylene Glycols ; chemistry ; RNA, Messenger ; genetics ; metabolism ; Rabbits ; Transfection ; methods

Bone cells live in an environment heavily influenced by mechanical force. The development of bone tissue is dependent on the environment that surrounds it, both in vivo and in vitro. A loading stimulator on research of bone tissue-engineering was developed based on the mechanism of mechanosensation, scaffolding composites with mechanical strains with more physiologic magnitude, frequency components, and waveform. It also achieves the mechanical environment particularly in hard scaffold enough strong like cancellous bone. The device was tested using a reference scaffold made of better elastic plastic material. The experiment results showed that the device could be used in precision strain controls. Since the drive of the stimulator comes from the usage of smart material, piezoceramics, the strain at physiological level is controlled precisely. The stimulator provides a mechanical condition under which the effects of loading applied on bone tissue-engineering culture are conveniently investigated. Furthermore, after the stimulator is improved, it will be an appropriate bioreactor for bone tissue-engineering culture.
Bioreactors ; Bone and Bones ; cytology ; Cell Differentiation ; Cells, Cultured ; Humans ; Mechanotransduction, Cellular ; Osteoblasts ; cytology ; metabolism ; Stress, Mechanical ; Tissue Engineering ; instrumentation ; methods ; Tissue Scaffolds

OBJECTIVETo study the compatibility between human adipose-derived mesenchymal stem cells and porcine bone scaffolds.

METHODSPorcine bone tissues were co-cultured with adipose-derived mesenchymal stem cells, and the complex was observed under scanning electron microscope. The viability and alkaline phosphatase (ALP) activity of the cells were examined with the cells co-cultured with human bone scaffold as the control.

RESULTSAt 4 and 10 days after the co-culture, the adipose-derived mesenchymal stem cells were observed to extend pseudopodia to adhere to the two scaffold materials. MTT assay showed that the cell proliferation on both of the materials increased with time, and the two cell complexes exhibited similar pattern of changes in ALP activity.

CONCLUSIONAs the seed cells, human adipose-derived mesenchymal stem cells exhibit good comparability with porcine bone scaffold, suggesting their potential of constructing tissue-engineered bone graft.

Adipose Tissue ; cytology ; Adult ; Alkaline Phosphatase ; metabolism ; Animals ; Bone and Bones ; cytology ; metabolism ; Cell Proliferation ; Coculture Techniques ; Humans ; Materials Testing ; Mesenchymal Stromal Cells ; cytology ; enzymology ; metabolism ; ultrastructure ; Microscopy, Electron, Scanning ; Swine ; Time Factors ; Tissue Scaffolds

Mesenchymal stem cells (MSCs) have the capabilities for self-renewal and differentiation into cells with the phenotypes of bone, cartilage, neurons and fat cells. These features of MSCs have attracted the attention of investigators for using MSCs for cell-based therapies to treat several human diseases. Because bone marrowderived cells, which are a main source of MSCs, are not always acceptable due to a significant drop in their cell number and proliferative/differentiation capacity with age, human umbilical cord blood (UCB) cells are good substitutes for BMCs due to the immaturity of newborn cells. Although the isolation of hematopoietic stem cells from UCB has been well established, the isolation and characterization of MSCs from UCB still need to be established and evaluated. In this study, we isolated and characterized MSCs. UCB-derived mononuclear cells, which gave rise to adherent cells, exhibited either an osteoclast or a mesenchymal-like phenotype. The attached cells with mesenchymal phenotypes displayed fibroblast-like morphologies, and they expressed mesenchymal-related antigens (SH2 and vimentin) and periodic acid Schiff activity. Also, UCB-derived MSCs were able to transdifferentiate into bone and 2 types of neuronal cells, in vitro. Therefore, it is suggested that the MSCs from UCB might be a good alternative to bone marrow cells for transplantation or cell therapy.
Acid Phosphatase/metabolism ; Bone and Bones/*cytology ; Cell Differentiation/*physiology ; Cell Separation/methods ; Fetal Blood/*cytology ; Humans ; Immunohistochemistry ; Immunophenotyping ; Infant, Newborn ; Mesenchymal Stem Cells/*cytology ; Microscopy, Phase-Contrast ; Neurons/*cytology ; Periodic Acid-Schiff Reaction

OBJECTIVE: To determine the cellular compatibility of combined deproteinized bone(DPB) coated with hepatocyte growth factor (HGF), and to observe the adherent effect of osteoblasts in response to HGF. METHODS: Osteoblasts were isolated from fetal rabbits. Osteoblasts were cultured with DPB coated with HGF and deproteinized bone as experimental group and contral group, respectively. The proliferation and alkalinephosphatase activity were tested. Their growth was examined by inverted phase contrast microscope and scanning electronmicroscope. RESULTS: The osteoblasts were attached to the outside and inside surfaces and grew well. HGF/DPB could stimulate the alkalinephosphatase activity of the osteoblasts and improve the proliferation of the osteoblasts. CONCLUSION HGF/DPB has good biocompatibility and bone induction. HGF could improve the adherent effect of DPB on osteoblasts, and it could be used as scaffold material for the bone tissue engineering.
Animals ; Biocompatible Materials ; pharmacology ; Bone Substitutes ; metabolism ; Bone and Bones ; cytology ; Cell Proliferation ; Cells, Cultured ; Female ; Fetus ; Hepatocyte Growth Factor ; pharmacology ; Osteoblasts ; cytology ; Osteogenesis ; Pregnancy ; Rabbits ; Tissue Engineering ; methods ; Tissue Scaffolds

The temporal expression of estrogen receptor (ER)-alpha and ER-beta mRNA was examined in male Japanese quails. Femurs of quails receiving 17beta-estradiol underwent RTPCR and histochemical analysis 1 to 15 days after treatment. Untreated quails were used as controls (day 0). Between days 0 and 5, cells lining the bone endosteal surface differentiated into osteoblasts, which in turn formed medullary bone. Expression of ER-alpha was already observed on day 0 and increased slightly during bone formation whereas ER-beta was hardly detected throughout this process. After osteoclasts appeared on the medullary bone surface, this type of bone disappeared from the bone marrow cavity (days 7~15). ER-alpha expression simultaneously decreased slightly and ER-beta levels remained very low. These results suggest that estrogen activity mediated by ER-alpha not only affects medullary bone formation but also bone resorption.
Animals ; Bone Resorption/genetics ; Bone and Bones/chemistry/cytology/*metabolism ; Cells, Cultured ; Coturnix/*metabolism ; Estradiol/*pharmacology ; Estrogen Receptor alpha/genetics/*metabolism ; Estrogen Receptor beta/genetics/*metabolism ; Gene Expression Regulation ; Male ; Osteoblasts/chemistry/cytology/*metabolism ; Osteogenesis/genetics ; RNA, Messenger/metabolism ; Reverse Transcriptase Polymerase Chain Reaction

BACKGROUNDRadiation-induced injury after accidental or therapeutic total body exposure to ionizing radiation has serious pathophysiological consequences, and currently no effective therapy exists. This study was designed to investigate whether transplantation of allogeneic murine compact bone derived-mesenchymal stem cells (CB-MSCs) could improve the survival of mice exposed to lethal dosage total body irradiation (TBI), and to explore the potential immunoprotective role of MSCs.

METHODSBALB/c mice were treated with 8 Gy TBI, and then some were administered CB-MSCs isolated from C57BL/6 mice. Survival rates and body weight were analyzed for 14 days post-irradiation. At three days post-irradiation, we evaluated IFN-γ and IL-4 concentrations; CD4(+)CD25(+)Foxp3(+) regulatory T cell (Treg) percentage; CXCR3, CCR5, and CCR7 expressions on CD3(+) T cells; and splenocyte T-bet and GATA-3 mRNA levels. CB-MSC effects on bone marrow hemopoiesis were assessed via colony-forming unit granulocyte/macrophage (CFU-GM) assay.

RESULTSAfter lethal TBI, compared to non-transplanted mice, CB-MSC-transplanted mice exhibited significantly increased survival, body weight, and CFU-GM counts of bone marrow cells (P < 0.05), as well as higher Treg percentages, reduced IFN-γ, CXCR3 and CCR5 down-regulation, and CCR7 up-regulation. CB-MSC transplantation suppressed Th1 immunity. Irradiated splenocytes directly suppressed CFU-GM formation from bone marrow cells, and CB-MSC co-culture reversed this inhibition.

CONCLUSIONAllogeneic CB-MSC transplantation attenuated radiation-induced hematopoietic toxicity, and provided immunoprotection by alleviating lymphocyte-mediated CFU-GM inhibition, expanding Tregs, regulating T cell chemokine receptor expressions, and skewing the Th1/Th2 balance toward anti-inflammatory Th2 polarization.

Animals ; Bone and Bones ; cytology ; Cytokines ; metabolism ; Female ; Granulocyte-Macrophage Progenitor Cells ; cytology ; Male ; Mesenchymal Stem Cell Transplantation ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Whole-Body Irradiation ; adverse effects

OBJECTIVETo observe the function of wnt/β-catenin signal pathway on the process that epimedium-derived flavonoids (EFs) regulate the balance between osteogenic differentiation and adipogenic differentiation in bone marrow stromal cells of ovariectomized rats, and to provide an experimental evidence for the mechanism of EFs on treating postmenopausal osteoporosis.

METHODSBone marrow stromal cells from ovariectomized rats were separated and cultivated in the condition of osteoinductive medium or liquid medium for 15 days. Low- (1 μg/mL), medium- (10 μg/mL) and high- (100 μg/mL) dose EFs were administrated correspondingly. Alkaline phosphatase (ALP) staining, ALP activity determination, oil red O staining and realtime polymerese chain reaction (RT-PCR) were used to determine the effect of EFs on osteogenic differentiation and adipogenic differentiation in bone marrow stromal cells of ovariectomized rats. Moreover, in order to explore the mechanism of EFs on osteogenic differentiation and adipogenic differentiation in bone marrow stromal cells of ovariectomized rats, Dickkopf-related protein 1 (DKK1) was used in the medium group. Enzymelinked immunosorbent assay (ELISA) and RT-PCR were used to determine mRNA levels of β-catenin, low density lipoprotein receptor-related protein 5 (LRP5) and T cell factor (TCF) protein, known as wnt/β-catenin signal pathway related factors.

RESULTSEFs increased mRNA expression levels of ALP and early osteoblast differentiation factors, such as runt-related transcription factor 2 (Runx2), osteocalcin and collagen I, and decreased mRNA expression levels of fat generation factors, such as peroxisome proliferator activated receptor gamma 2 (PPARγ-2) and CCAAT enhancer-binding protein-α (C/EBPα) in a dose-dependent manner. While osteoblast differentiation factors were down-regulated, fat generation factors were up-regulated when DKK1 was applied. Also EFs up-regulated mRNA expression levels of β-catenin, LRP5 and TCF protein which could be blocked by DKK1.

CONCLUSIONEFs regulate the balance between osteogenic differentiation and adipogenic differentiation in bone marrow stromal cells of ovariectomized rats by activating wnt/β-catenin signal pathway, which may be an important molecular mechanism of EFs on treating postmenopausal osteoporosis.

Adipose Tissue ; cytology ; drug effects ; metabolism ; Animals ; Base Sequence ; Bone and Bones ; cytology ; drug effects ; metabolism ; Cell Differentiation ; drug effects ; DNA Primers ; Enzyme-Linked Immunosorbent Assay ; Epimedium ; chemistry ; Female ; Flavonoids ; pharmacology ; Flow Cytometry ; Mesenchymal Stromal Cells ; cytology ; drug effects ; metabolism ; Rats ; Real-Time Polymerase Chain Reaction ; Signal Transduction ; Wnt Proteins ; metabolism ; beta Catenin ; metabolism