OBJECTIVE: To explore the mechanism of the Notch1 signaling pathway in regulating osteogenic factors and influencing lumbar disc calcification. METHODS: Primary annulus fibroblasts from SD rats were isolated and subcultured in vitro. The calcification-inducing factors bone morphogenetic protein-2 (BMP-2) and basic fibroblast growth factor (b-FGF) were added to separate groups to induce calcification, which were referred to as the BMP-2 group and the b-FGF group, respectively. A control group was also set up, which was cultured in normal medium. Subsequently, cell morphology and fluorescence identification, alizarin red staining, ELISA, and quantitative real-time polymerase chain reaction (QRT-PCR) were performed to determine the effect of calcification induction. Cell grouping was performed again, including the control group, the calcification group (adding the inducer BMP-2), the calcification + LPS group(adding the inducer BMP-2 and the Notch1 pathway activator LPS), and the calcification + DAPT group (adding the inducer BMP-2 and the Notch1 pathway inhibitor DAPT). Alizarin red staining and flow cytometry were used to detect cell apoptosis, ELISA was used to detect the content of osteogenic factors, and Western blot was used to detect the expression of BMP-2, b-FGF, and Notch1 proteins. RESULTS: The induction factor screening results showed that the number of mineralized nodules in fibroannulus cells in BMP-2 group and b-FGF group was significantly increased, and the increase was greater in the BMP-2 group Meanwhile, ELISA and Western blot results showed that BMP-2, b-FGF and mRNA expression levels of BMP-2, b-FGF and Notch1 in the induced group were significantly increased (P<0.01). The results of the mechanism of Notch1 signaling pathway affecting lumbar disc calcification showed that compared to calcified group, the number of fibroannulus cell mineralization nodules, apoptosis rate, BMP-2, b-FGF content, the expression levels of BMP-2, b-FGF, and Notch1 proteins were further increased significantly However, the number of mineralization nodules, apoptosis rate, BMP-2 and b-FGF levels, BMP-2, b-FGF and Notch1 protein expression levels were decreased in the calcified +DAPT group (P<0.05 or P<0.01). CONCLUSION Notch1 signaling pathway promotes lumbar disc calcification through positive regulation of osteogenic factors.
Animals ; Rats ; Bone Morphogenetic Protein 2/metabolism* ; Calcinosis ; Cell Differentiation ; Cells, Cultured ; Lipopolysaccharides ; Osteogenesis ; Rats, Sprague-Dawley ; Receptor, Notch1/genetics* ; Signal Transduction

OBJECTIVE: To screen for BMP2 mutation with functional impact in patients with congenital tooth agenesis and to make oral and skeletal phenotype record and functional analysis with in vitro experiments. METHODS: We enrolled eighteen patients with congenital tooth agenesis. The medical and dental history was collected,and clinical and dental examinations including the X-ray examination of oral-facial and skeletal bone were performed for the phenotypic analysis. Blood samples were collected to extract DNA and whole exome sequencing was conducted. The genes involved in oral-facial development and congenital skeletal diseases were investigated for mutation screening. The mutations with functional impact were then investigated. In one patient, the BMP2 mutation with putative functional impact was selected for functional analysis. Wild type and mutant BMP2 plasmids with green fluorescent protein (GFP) tag were constructed and transfected into HEK293T cells. Subcellular protein distribution was observed under laser scanning confocal microscope. The activation of downstream SMAD1/5/9 phosphorylation by BMP2 was detected by Western blotting to investigate the functional impact and genetic pathogenicity. RESULTS: BMP2 mutation NM_001200.3:c.393A>T (p.Arg131Ser), rs140417301 was detected in one patient with congenital tooth agenesis, while for other genes involved in oral-facial development and congenital skeletal diseases, no functionally significant mutation was found. The proband's parents didn't carry this mutation. The father had normal dentition, while the mother lacked one premolar, and both the parents showed normal palate and maxilla. The patient also had maxillary hypoplasia in both sagittal and coronal planes, palatal dysmorphology, and malocclusion, and was diagonsed with osteopenia after the X-ray examnination of his skeletal bone. Functional analysis showed this mutation had normal subcelluar localization but reduced phosphorylation of SMAD1/5/9 (reduction by 32%, 22%, and 27% in three independent replicates). Taken together with family co-segregation, this mutaion was considered as "likely pathogenic". CONCLUSION BMP2 mutation c.393A>T (p. Arg131Ser) affects bone morphogenetic protein signaling activity, and may affect the number of teeth, growth of maxilla and palate, and bone mineral density.
Bone Morphogenetic Protein 2/genetics* ; HEK293 Cells ; Humans ; Mutation ; Phenotype ; Plasmids ; Tooth

Human telomerase reverse transcriptase (hTERT) plays a central role in telomere lengthening for continuous cell proliferation, but it remains unclear how extracellular cues regulate telomerase lengthening of telomeres. Here we report that the cytokine bone morphogenetic protein-7 (BMP7) induces the hTERT gene repression in a BMPRII receptor- and Smad3-dependent manner in human breast cancer cells. Chonic exposure of human breast cancer cells to BMP7 results in short telomeres, cell senescence and apoptosis. Mutation of the BMPRII receptor, but not TGFbRII, ACTRIIA or ACTRIIB receptor, inhibits BMP7-induced repression of the hTERT gene promoter activity, leading to increased telomerase activity, lengthened telomeres and continued cell proliferation. Expression of hTERT prevents BMP7-induced breast cancer cell senescence and apoptosis. Thus, our data suggest that BMP7 induces breast cancer cell aging by a mechanism involving BMPRII receptor- and Smad3-mediated repression of the hTERT gene.
Actin-Related Protein 2 ; genetics ; metabolism ; Activin Receptors, Type II ; genetics ; metabolism ; Bone Morphogenetic Protein 7 ; genetics ; metabolism ; Bone Morphogenetic Protein Receptors, Type II ; genetics ; metabolism ; Breast Neoplasms ; genetics ; metabolism ; Cellular Senescence ; Female ; HeLa Cells ; Humans ; MCF-7 Cells ; Neoplasm Proteins ; genetics ; metabolism ; Protein-Serine-Threonine Kinases ; genetics ; metabolism ; Receptor, Transforming Growth Factor-beta Type II ; Receptors, Transforming Growth Factor beta ; genetics ; metabolism ; Smad3 Protein ; genetics ; metabolism ; Telomerase ; genetics ; metabolism ; Telomere Homeostasis

PURPOSE: To explore the value of transplanting peripheral blood-derived mesenchymal stem cells from allogenic rabbits (rPBMSCs) to treat osteonecrosis of the femoral head (ONFH). MATERIALS AND METHODS: rPBMSCs were separated/cultured from peripheral blood after granulocyte colony-stimulating factor mobilization. Afterwards, mobilized rPBMSCs from a second passage labeled with PKH26 were transplanted into rabbit ONFH models, which were established by liquid nitrogen freezing, to observe the effect of rPBMSCs on ONFH repair. Then, the mRNA expressions of BMP-2 and PPAR-γ in the femoral head were assessed by RT-PCR. RESULTS: After mobilization, the cultured rPBMSCs expressed mesenchymal markers of CD90, CD44, CD29, and CD105, but failed to express CD45, CD14, and CD34. The colony forming efficiency of mobilized rPBMSCs ranged from 2.8 to 10.8 per million peripheral mononuclear cells. After local transplantation, survival of the engrafted cells reached at least 8 weeks. Therein, BMP-2 was up-regulated, while PPAR-γ mRNA was down-regulated. Additionally, bone density and bone trabeculae tended to increase gradually. CONCLUSION: We confirmed that local transplantation of rPBMSCs benefits ONFH treatment and that the beneficial effects are related to the up-regulation of BMP-2 expression and the down-regulation of PPAR-γ expression.
Animals ; Blood Cells/*cytology ; Bone Morphogenetic Protein 2/genetics ; *Cell- and Tissue-Based Therapy ; Femur Head Necrosis/metabolism/*pathology/*therapy ; Gene Expression Regulation ; *Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells/*cytology ; Osteonecrosis/*pathology/*therapy ; PPAR gamma/genetics ; Rabbits ; Transplantation, Homologous

OBJECTIVETo observe the impact of bone morphogenetic protein-2 (rhBMP-2) on bone marrow stromal cells (BMSCs) osteogenesis in vitro and vascular endothelial growth factors (VEGF) expression in bone osteoporotic to prevent and treat the osteoporosis.

METHODSTwenty 6-month-old female SD rats weighted (300±20) g underwent bilateral ovariectomized. At 3 months after operation, dual-energy X-ray absorptiometry was used to measure bone mineral density of rats,the values were compared with preoperative to ensure the model successfully, and the osteoporosis rats' BMSCs were cultured by bone marrow adherent cultured and the BMSCs morphology was observed under a phase contrast microscope upside down. The osteoporosis rats' BMSCs at the 2nd generation (p2) were randomly divided into experimental and control groups and were added complete medium (containing rhBMP-2) and osteogenic induced liquid, respectively. Two weeks later, the formation of cell calcium nodules were detected by Alizarin red staining method,alkaline phosphatase activity was measured by enzyme standard instrument and the expression of VEGF was detected by RT-PCT method.

RESULTS(1)Whole body bone mineral density of rats before and after operation were (0.179±0.007), (0.158±0.006) g/cm2,there was statistically significant (t=4.180,P< 0.05). (2)Alizarin red staining at 2 weeks after osteogenesis induced by BMSCs (P2) in the experimental group had more strong dyeing effect than the control group obviously. (3)Alkaline phosphatase activity at 2 weeks after osteogenesis induced by BMSCs (P2) of the experimental group (15.62±1.27) ug/gprot was significantly higher than that of the control group (8.62±0.93) ug/gprot,there was statistically significant (t=7.709, P<0.01). (4)The expression of VEGF at 2 weeks after osteogenesis induced by BMSCs (P2) of the experimental group 3.723±0.143 was significantly higher than that of the control group 0.950±0.072, there was statistically significant (t=29.462, P<0.01).

CONCLUSIONRhBMP-2 can improve the in-vitro osteogenesis ability of ovary osteoporosis rat BMSCs, promote the VEGF expression of osteogenesis factor. Regulating the VEGF expression may be one of the mechanisms of BMP-2 to participate in bone metabolism.

Animals ; Bone Density ; Bone Morphogenetic Protein 2 ; genetics ; metabolism ; Cells, Cultured ; Female ; Humans ; In Vitro Techniques ; Mesenchymal Stromal Cells ; cytology ; metabolism ; Osteogenesis ; Osteoporosis, Postmenopausal ; genetics ; metabolism ; physiopathology ; Rats ; Rats, Sprague-Dawley ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

Fucoidan has attracted attention as a potential drug because of its biological activities, which include osteogenesis. However, the molecular mechanisms involved in the osteogenic activity of fucoidan in human alveolar bone marrow-derived mesenchymal stem cells (hABM-MSCs) remain largely unknown. We investigated the action of fucoidan on osteoblast differentiation in hABM-MSCs and its impact on signaling pathways. Its effect on proliferation was determined using the crystal violet staining assay. Osteoblast differentiation was evaluated based on alkaline phosphatase (ALP) activity and the mRNA expression of multiple osteoblast markers. Calcium accumulation was determined by Alizarin red S staining. We found that fucoidan induced hABM-MSC proliferation. It also significantly increased ALP activity, calcium accumulation and the expression of osteoblast-specific genes, such as ALP, runt-related transcription factor 2, type I collagen-alpha 1 and osteocalcin. Moreover, fucoidan induced the expression of bone morphogenetic protein 2 (BMP2) and stimulated the activation of extracellular signal-related kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase by increasing phosphorylation. However, the effect of fucoidan on osteogenic differentiation was inhibited by specific inhibitors of ERK (PD98059) and JNK (SP600125) but not p38 (SB203580). Fucoidan enhanced BMP2 expression and Smad 1/5/8, ERK and JNK phosphorylation. Moreover, the effect of fucoidan on osteoblast differentiation was diminished by BMP2 knockdown. These results indicate that fucoidan induces osteoblast differentiation through BMP2-Smad 1/5/8 signaling by activating ERK and JNK, elucidating the molecular basis of the osteogenic effects of fucoidan in hABM-MSCs.
Bone Morphogenetic Protein 2/genetics/*metabolism ; Calcium/metabolism ; Cell Differentiation/drug effects ; Cell Proliferation/drug effects ; Cells, Cultured ; Dose-Response Relationship, Drug ; Extracellular Signal-Regulated MAP Kinases/*metabolism ; Gene Expression Regulation/drug effects ; Gene Knockdown Techniques ; Humans ; JNK Mitogen-Activated Protein Kinases/*metabolism ; Mesenchymal Stromal Cells/cytology/*drug effects/*metabolism ; Osteoblasts/cytology/drug effects/metabolism ; Osteogenesis/drug effects ; Phosphorylation ; Polysaccharides/*pharmacology ; Protein Kinase Inhibitors/pharmacology ; RNA, Messenger/genetics ; Signal Transduction/*drug effects ; Smad Proteins/*metabolism

PURPOSE: To investigate the molecular responses of various genes and proteins related to disc degeneration upon treatment with cytokines that affect disc-cell proliferation and phenotype in living human intervertebral discs (IVDs). Responsiveness to these cytokines according to the degree of disc degeneration was also evaluated. MATERIALS AND METHODS: The disc specimens were classified into two groups: group 1 (6 patients) showed mild degeneration of IVDs and group 2 (6 patients) exhibited severe degeneration of IVDs. Gene expression was analyzed after treatment with four cytokines: recombinant human bone morphogenic protein (rhBMP-2), transforming growth factor-beta (TGF-beta), interleukin-1beta (IL-1beta), and tumor necrosis factor-alpha (TNF-alpha). Molecular responses were assessed after exposure of cells from the IVD specimens to these cytokines via real-time polymerase chain reaction and immunofluorescence staining. RESULTS: mRNA gene expression was significantly greater for aggrecan, type I collagen, type II collagen, alkaline phosphatase, osteocalcin, and Sox9 in group 1 than mRNA gene expression in group 2, when the samples were not treated with cytokines. Analysis of mRNA levels for these molecules after morphogen treatment revealed significant increases in both groups, which were much higher in group 1 than in group 2. The average number of IVD cells that were immunofluorescence stained positive for alkaline phosphatase increased after treatment with rhBMP-2 and TGF-beta in group 1. CONCLUSION: The biologic responsiveness to treatment of rhBMP-2, TGF-beta, TNF-alpha, and IL-1beta in the degenerative living human IVD can be different according to the degree of degeneration of the IVD.
Adult ; Aggrecans/genetics/metabolism ; Alkaline Phosphatase/genetics/metabolism ; Biological Products/pharmacology/*therapeutic use ; Bone Morphogenetic Protein 2/pharmacology/therapeutic use ; Collagen Type I/genetics/metabolism ; Collagen Type II/genetics/metabolism ; Cytokines/*pharmacology/*therapeutic use ; Female ; Fluorescent Antibody Technique ; Gene Expression Regulation/drug effects ; Humans ; Interleukin-1/pharmacology/therapeutic use ; Intervertebral Disc/*drug effects/*pathology ; Intervertebral Disc Degeneration/*drug therapy/genetics/*pathology ; Male ; Middle Aged ; Osteocalcin/genetics/metabolism ; RNA, Messenger/genetics/metabolism ; Recombinant Proteins/pharmacology/therapeutic use ; SOX9 Transcription Factor/genetics/metabolism ; Transforming Growth Factor beta/pharmacology/therapeutic use ; Tumor Necrosis Factor-alpha/pharmacology

OBJECTIVETo investigate the effect of co-expression of bone morphogenetic protein 2 (BMP2) and Sox9 on chondrogenic differentiation of mesenchymal stem cells (MSCs) in vitro and provide experimental evidence for tissue engineering of cartilage.

METHODSMouse embryonic bone marrow MSC C3H10T1/2 cells were infected with recombinant adenovirus expressing BMP2, Sox9 and green fluorescent protein (GFP) for 3-14 days, with cells infected with the adenovirus carrying GFP gene as the control. The mRNA expression of the markers of chondrogenic differentiation, including collagen type II (Col2a1), aggrecan (ACAN), and collagen type X (Col10a1), were determined by real-time PCR. Alcian blue staining was used for quantitative analysis of sulfated glycosaminoglycan in the cellular matrix. The expression of Col2a1 protein was assayed by immunohistochemical staining and Western blot analysis.

RESULTSAdenovirus-mediated BMP2 expression induced chondrogenic differentiation of C3H10T1/2 cells. Overexpression of Sox9 effectively enhanced BMP2-induced expression of the chondrogenic markers Col2a1, aggrecan and Col10a1 mRNAs, and promoted the synthesis of sulfated glycosaminoglycan and Col2a1 protein in C3H10T1/2 cells.

CONCLUSIONCo-expression of BMP2 and Sox9 can promote chondrogenic differentiation of MSCs in vitro, which provides a new strategy for tissue engineering of cartilage.

Animals ; Bone Morphogenetic Protein 2 ; genetics ; metabolism ; Cartilage ; cytology ; Cell Differentiation ; Cells, Cultured ; Chondrocytes ; cytology ; Humans ; Mesenchymal Stromal Cells ; cytology ; metabolism ; Mice ; SOX9 Transcription Factor ; genetics ; metabolism ; Tissue Engineering

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

Aortic valve calcification is a common disease in the elderly, but its cellular and molecular mechanisms are not clear. In order to verify the hypothesis that Wnt/β-catenin signaling pathway is involved in the process of calcification of aortic valve, porcine aortic valve interstitial cells (VICs) were isolated, cultured and stimulated with oxidized low density lipoprotein (ox-LDL) for 48 h to induce the differentiation of VICs into osteoblast-like cells. The key proteins and genes of Wnt/β-catenin signaling pathway, such as glycogen synthase kinase 3β (GSK-3β) and β-catenin, were detected by using Western blotting and real-time polymerase chain reaction (PCR). The results showed that the VICs managed to differentiate into osteoblast-like cells after the stimulation with ox-LDL and the levels of proteins and genes of GSK-3β and β-catenin were increased significantly in VICs after stimulation for 48 h (P<0.05). It is suggested that Wnt/β-catenin signaling pathway may play a key role in the differentiation of VICs into osteoblast-like cells and make great contribution to aortic valve calcification.
Alkaline Phosphatase ; genetics ; metabolism ; Animals ; Aortic Valve ; metabolism ; pathology ; Aortic Valve Stenosis ; Blotting, Western ; Bone Morphogenetic Protein 2 ; genetics ; metabolism ; Calcinosis ; Cell Differentiation ; drug effects ; genetics ; Cells, Cultured ; Gene Expression ; drug effects ; Glycogen Synthase Kinase 3 ; genetics ; metabolism ; Lipoproteins, LDL ; pharmacology ; Osteoblasts ; drug effects ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Swine ; Wnt Signaling Pathway ; genetics ; physiology ; beta Catenin ; genetics ; metabolism