Bone morphogenetic protein (BMP) homodimers are of significant osteoinductivity. However, their clinical application is limited because of high effective dosage. Recently, BMP heterodimers are reported to address the issue. This is a review of the researches on BMP heterodimers, including existent evidences, types and synthetic methods, biological activities in comparison to BMP homodimers and possible mechanisms, further research direction and future expectations.
Animals ; Biopolymers ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Protein 7 ; Bone Morphogenetic Proteins ; genetics ; pharmacology ; Humans ; Protein Multimerization

The bone morphogenetic protein (BMP) family is an important factor in the regulation of cell ular life activities and in the development of almost all tissues. BMP-mediated signaling plays an important role in tooth root development, which is a part of tooth development. Epithelial and mesenchymal interactions are involved in tooth root development, but the BMP signaling pathway has a different effect on tooth root development in epithelial and mesenchymal. This review summarizes the advances of BMP signaling in tooth root development.
Bone Morphogenetic Protein 2 ; Bone Morphogenetic Protein 7 ; Bone Morphogenetic Proteins ; physiology ; Odontogenesis ; Signal Transduction ; Tooth ; Tooth Root ; growth & development

BACKGROUNDThe palate is differently regulated and developed along the anterior-posterior axis. The Bmp signal pathway plays a crucial role in palatogenesis. Conditioned-inactivation of Bmp type I receptor Alk2 or Alk3 in the neural crest or craniofacial region leads to palatal cleft in mice. However, how different Bmp members are involved in palatogenesis remains to be elucidated. In the present study, mRNA expression patterns of Bmp2, Bmp3 and Bmp4 in the developing anterior and posterior palates were examined and compared, focusing on the fusion stage.

METHODSTo detect the expression of Bmp mRNA, antisense riboprobes were synthesized by in vitro transcription. Radioactive in situ hybridization was performed on sagital and coronal sections of mice head from E13 to E18.

RESULTSThe expression of these Bmps were developmentally regulated in the anterior and posterior palates prior to, during and after palatal fusion. During palatal fusion, Bmp4 expression shifted from the anterior to the posterior palate, Bmp2 was highly expressed in both the anterior and posterior palates in this process, whereas Bmp3 was only localized in the posterior palate. They showed generally non-overlapping pattern in their expression domains. Thereafter, their expression was detected in both the anterior and posterior palates regulating osteogenesis and myogenesis respectively.

CONCLUSIONSBmp signalling is involved in palatogenesis in multiple stages and has multiple roles in regulating anterior and posterior palatal development. Disturbances of Bmp signalling during palatogenesis might be a possible mechanism of cleft palate.

Animals ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Protein 3 ; Bone Morphogenetic Protein 4 ; Bone Morphogenetic Proteins ; genetics ; Female ; Gene Expression Regulation, Developmental ; Mice ; Palate ; embryology ; metabolism ; RNA, Messenger ; analysis ; Signal Transduction ; Transforming Growth Factor beta ; genetics

OBJECTIVE: To investigate the effect of human bone morphogenetic protein (hBMPs) 2/3/6 and 12 on osteosarcoma cell UMR106. METHODS: Adenovirus-BMP2/3/6 and 12 (AdBMP2/3/6 and12) were used to treat the cell line. Their proliferation, apoptosis, and transmigration were detected by Trypan blue exclusion test, TdT-mediated biotinylated-dUTP nick end labeling (TUNEL), acridine orange-ethidium bromide (AO/EB) double fluorescent dye staining, and transwell-room test, respectively. The alkaline phosphatase (ALP) activity was detected to reflect the differentiation of tumors. RESULTS: Compared with the control groups, the cell survival rate of the experimental groups treated with AdBMP2/3/6 and 12 showed a significant time-dependent decrease (P<0.01). The apoptosis indexes were increased significantly (P<0.01) and the results from TUNEL and AO/EB method were consistent. The cell numbers of transmembrane significantly decreased at 24,48, and 72 h (P<0.01). AdBMP2/3/6 and 12 treatment enhanced the activity of ALP activity from day 3 and this effect might still be observed up to day 9 of the treatment (P<0.01). CONCLUSION hBMPs2/3/6 and 12 can inhibit the proliferation and transmigration, and induce their apoptosis and differentiation in osteosarcoma cell line UMR106.
Adenoviridae ; genetics ; metabolism ; Apoptosis ; drug effects ; Bone Morphogenetic Protein 2 ; pharmacology ; Bone Morphogenetic Protein 3 ; pharmacology ; Bone Morphogenetic Protein 6 ; pharmacology ; Bone Morphogenetic Proteins ; pharmacology ; Bone Neoplasms ; pathology ; Cell Line, Tumor ; Cell Transformation, Neoplastic ; drug effects ; Growth Differentiation Factors ; pharmacology ; Humans ; Osteosarcoma ; pathology ; Recombinant Proteins ; pharmacology

PURPOSE: Gene therapy (ex vivo) has recently been used as a means of delivering bone morphogenetic proteins (BMPs) to sites of tissue regeneration. In the present study, we investigated the effect of co-transduction of adenoviruses expressing BMP-2 and BMP-7 on osteogenesisof C2C12 cells in vitro. METHODS: A replication-defective human adenovirus 5 (Ad5) containing a cDNA for BMPs in the E1 region of the virus (Ad5BMP-2 and Ad5BMP-7) was constructed by in vivo homologous recombination. Functional activity of Ad5BMP-2 and Ad5BMP-7 were evaluated in mouse stromal cells (W20-17cells). C2C12 cells are transduced with various MOI (multiplicity of infection) of Ad5BMP-2 and Ad5BMP-7 to assess most effective and stable titer. Based on this result, C2C12 cells were transduced with Ad5BMP-2 and Ad5BMP-7 alone or by combination. BMPs expression, alkaline phosphatase (ALPase) activity, cell proliferation, and mineralization were assessed. RESULTS: Ad5BMP-2 and Ad5BMP-7 are successfully transduced to W20-17 cells, and secreted BMPs stimulated cell differentiation. Also, C2C12 cells transduced with Ad5BMPs showed expression of BMPs and increased ALPaseactivity. In all groups, cell proliferation was observed over times. At 7days, cells co-transduced with Ad5BMP-2 and Ad5BMP-7 showed lower proliferation than the others. C2C12 cells co-transduced with Ad5BMP-2 and Ad5BMP-7 had greater ALPaseactivity than that would be predicted if effect of individual Ad5BMPs were additive. Little mineralized nodule formation was detected in cells transduced with individual Ad5BMPs. In contrast, Ad5BMP-2 and Ad5BMP-7 combination stimulated mineralization after culturing for 10 days in mineralizing medium. CONCLUSIONS: Present study demonstrated that adenoviruses expressing BMPs gene successfully produced BMPs protein and these BMPs stimulated cells to be differentiated into osteoblastic cells. In addition, the osteogenic activity of Ad5BMPs can be synergistically increased by co-transduction of cells with Ad5BMP-2 and Ad5BMP-7.
Adenoviridae ; Adenoviruses, Human ; Alkaline Phosphatase ; Animals ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Protein 7 ; Bone Morphogenetic Proteins ; Cell Differentiation ; Cell Proliferation ; DNA, Complementary ; Durapatite ; Genetic Therapy ; Homologous Recombination ; Mice ; Osteoblasts ; Osteogenesis ; Regeneration ; Stromal Cells ; Viruses

OBJECTIVETo explore reciprocal action between BMP-2 (bone morphogenetic protein-2) and BMP-3 for better understanding of the mechanism of BMP during bone fracture union.

METHODSrhBMP-2 was added into the cultured fibroblasts with the concentration of 1,200 ng/ml. The expression of BMP-3 in fibroblasts was detected by immunohistochemistry. Eukaryotic expression vector pcDNA3-BMP-3 was transfected into the fibroblasts. After the effective expression of BMP-3 was identified, BMP-2 was also detected by immunohistochemistry in BMP-3 expression cells. The fibroblasts transfected with empty vector pcDNA3 were used as the control.

RESULTSExogenous rhBMP-2 could promote the expression of BMP-3 in fibroblasts. BMP-3 also could be detected in these cells.

CONCLUSIONSBMP-2 and BMP-3 could reciprocally adjust the expression in fibroblasts.

Bone Morphogenetic Protein 2 ; Bone Morphogenetic Protein 3 ; Bone Morphogenetic Proteins ; metabolism ; Cells, Cultured ; Fibroblasts ; metabolism ; Fracture Healing ; physiology ; Immunohistochemistry ; Osteogenesis ; physiology ; Transforming Growth Factor beta

OBJECTIVETo observe the ability of induced ectopic bone using skeletal muscles satellite cells (SMSCs) from newborn green fluorescence protein (GFP) transgenic mice mediated by Ad-BMP2.

METHODSTransplantation of SMSCs transduced with Ad-BMP2 into back lamb muscles of subfascia in wildtype 129sv mice with a complex of collagen scaffords, then the tissue histologic examination, X ray plain film, fluorescence microscopy were used.

RESULTSTransplantation of SMSCs transfected with Ad-BMP2 into back lamb muscles of subfascia generated ectopic bone formation involving GFP-positive osteoblasts and osteocytes 2 weeks and mature bone formation 4 weeks after transplantation. SMSCs non-transfected with Ad-BMP2 failed to induce ectopic bone formation.

CONCLUSIONSMSCs retain differentiation potentitality into osteoblasts in response to Ad-BMP2. They are useful tools for analyzing the process of osteoblast differentiation in vivo after transplantation.

Animals ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; Bone and Bones ; Cell Differentiation ; Fluorescence ; Genetic Vectors ; Green Fluorescent Proteins ; Mice ; Mice, Transgenic ; Myoblasts ; Osteoblasts ; Transfection ; Transforming Growth Factor beta

OBJECTIVETo examine the relationship between effect of vascular endothelial growth factor (VEGF) on epithelial-myofibroblast transition (EMT) of HK-2 cells and changes in expressions of bone morphogenetic protein-7 (BMP-7) and inhibitor of DNA binding/differentiation (Id) 2, Id3.

METHODSThe cultured HK-2 cells were co-treated with transforming growth factor-beta1 (TGF-beta1) (5 ng/ml) and VEGF165 (0.1, 1, 10, 100 ng/ml), or with TGF-beta1 (5 ng/ml) and VEGF receptor-1 neutralized antibody (10 microg/ ml), and were also co-treated with TGF-beta1 (5 ng/ml) and VEGF165 (100 ng/ml) with or without activin receptor-like kinase 6 (Alk6)/Fc Chimera (2 microg/ml, to neutralize endogenous BMP-7) for 48 hours. mRNA and protein expressions of alpha-smooth muscle actin (alpha-SMA), E-cadherin, BMP-7, Id2 and Id3 of HK-2 cells were assessed with double-stain immunocytochemistry, real-time PCR and Western blot respectively.

RESULTSCompared with normal controls, alpha-SMA expression significantly increased, while E-cadherin, BMP-7, Id2, and Id3 mRNA and protein expressions markedly decreased in HK-2 cells treated with TGF-beta1 (5 ng/ml) (P < 0.05). VEGF165 interrupted TGF-beta1 induced alpha-SMA expression in a dose-dependent manner and upregulated BMP-7, Id2 mRNA and protein expressions of the cells (P < 0.05). alpha-SMA expression increased, while E-cadherin, BMP-7, and Id2 expressions decreased further in HK-2 cells co-treated with TGF-beta1 and VEGFR1 antibody compared with normal controls (P < 0.05). When endogenous BMP-7 was neutralized with Alk6/Fc Chimera in the cells co-treated with TGF-beta1 and VEGF165, alpha-SMA expression upregulated (P < 0.05), while Id2 was not changed.

CONCLUSIONSVEGF165 may partially inhibit TGF-beta1-induced EMT of HK-2 cells in vitro. This effect is related to the upregulated expressions of BMP-7 and Id2. Id2 may be upregulated directly by VEGF165, but not related to BMP-7.

Bone Morphogenetic Protein 7 ; genetics ; metabolism ; Cell Differentiation ; Cell Line ; Epithelial Cells ; cytology ; metabolism ; Gene Expression Regulation ; Humans ; Inhibitor of Differentiation Protein 2 ; genetics ; metabolism ; Inhibitor of Differentiation Proteins ; genetics ; metabolism ; Neoplasm Proteins ; genetics ; metabolism ; Transforming Growth Factor beta1 ; metabolism ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

Animals ; Bone Morphogenetic Protein 2 ; metabolism ; Bone Morphogenetic Protein 4 ; metabolism ; Carrier Proteins ; pharmacology ; Liver ; metabolism ; Liver Regeneration ; Male ; Rats ; Rats, Wistar

OBJECTIVETo observe the expression of Runx2 in osteoblasts in response to centrifugation in vitro and discuss the function of bone morphogenetic protein (BMP) signal transduction pathway in this course.

METHODSCells were divided into four groups, group A, B, C and D, pretreated with DMEM containing 10% fetal bovine serum, 10% fetal bovine serum, 100 ng x mL(-1) Noggin and 100 ng x mL(-1) Noggin for 24 hours separately. 271 x g centrifugation was loaded for 5 min to these groups except group A and C, other conditions were the same. The total RNA of each group were extracted, and reversed transcription to cDNA after 30 min. The expression of Runx2 in response to centrifugation in vitro was analyzed by quantitative real time PCR.

RESULTSThe expression of Runx2 mRNA in group B was significantly higher than that in group A (P < 0.05). The expression of Runx2 mRNA in group D was significantly lower than that in group B (P < 0.05). There was no statistically significant difference among group A, C, D (P = 0.692).

CONCLUSIONBMP signal transduction pathway plays an important role in the response of osteoblasts to mechanical stimulations. It may also play a central role in the cascade information dissemination of osteoblasts.

Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; Cell Differentiation ; Centrifugation ; Core Binding Factor Alpha 1 Subunit ; Gene Expression Regulation ; Humans ; In Vitro Techniques ; Osteoblasts ; RNA, Messenger ; Signal Transduction