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

OBJECTIVETo investigate the effect of recombinant adenovirus-mediated bone morphogenetic protein (BMP)-2 and -3 over expressions on chondrogenesis and osteogenesis of prenatal mouse intervertebral disc cells and provide experimental evidences for the application of BMPs in the therapy of disc diseases.

METHODSThe prenatal mouse intervertebral disc cells were infected with a recombinant adenovirus expressing BMP-2 and BMP-3 for 5-7 days, and the expressions of collagen type I (Col I), collagen type II (Col II), aggrecan, osteocalcin, osteoprotegerin and osteopontin mRNAs were detected with RT-PCR. The expression of cartilage matrix was evaluated with toluidine blue staining, and alkaline phosphatase (ALP) activity was detected with ALP reading and ALP staining.

RESULTSBMP-2 and -3 overexpression did not enhance chondrogenesis and osteogenesis of annulus fibrosus (AF) cells or cause significant increases in the expressions of Col I, Col II or aggrecan mRNA in nucleus pulposus (NP) cells. Adenovirus-mediated overexpression of BMP-2 and BMP-3, however, promoted osteogenesis of NP cells and significantly increased the expression of osteocalcin mRNA; the overexpression of BMP-2, but not BMP-3, enhanced the mRNA expressions of osteoprotegerin and osteopontin. Toluidine blue staining demonstrated that BMP-2 and BMP-3 overexpression did not obviously affect the secretion of cartilage matrix. In NP cells, BMP-2 and -3 overexpression significantly enhanced ALP activity, which was not observed in AF cells.

CONCLUSIONAdenovirus-mediated BMP-2 and -3 overexpression can promote the osteogenic differentiation of NP cells but can not affect osteogenesis of AF cells or chondrogenesis of NP cells.

Animals ; Bone Morphogenetic Protein 2 ; pharmacology ; Bone Morphogenetic Protein 3 ; pharmacology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Chondrogenesis ; Intervertebral Disc ; cytology ; drug effects ; Mice ; Osteogenesis

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

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

Optimization of cultivation condition of recombinant E. coli DH5 alpha/pDH-B2m and the condition suitable for expression of recombinant mature peptide of human bone morphogenetic protein-2 was carried out in 500 mL shaking flasks and then transferred to NBS Bioflo IV, a 20 L DO feed-back fed-batch culture system, to obtain rhBMP-2. The results indicate that keeping dissolved oxygen at 40% and controlling nutrient feeding rate with DO feed back strategy can obtain theoretically 3.59 g recombinant mature peptide of hBMP-2 per liter of broth, the final cell density OD600 reaches 57(22.8 g dry cell weight/L), and the expression of rhBMP-2 amounts to 30% of the total protein in E. coli.
Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; biosynthesis ; genetics ; Culture Media ; Escherichia coli ; genetics ; Fermentation ; Glycerol ; pharmacology ; Recombinant Proteins ; biosynthesis ; Time Factors ; Transforming Growth Factor beta

A novel unsaturated polyphosphoester (UPPE) was devised in our previous research, which is a kind of promising scaffold for improving bone regeneration. However, the polymerization process of UPPE scaffolds was unfavorable, which may adversely affect the bioactivity of osteoinductive molecules added if necessary, such as recombinant human bone morphogenetic protein-2 (rhBMP2). The purpose of this study was to build a kind of optimal scaffold named UPPE-PLGA-rhBMP2 (UPB) and to investigate the bioactivity of rhBMP2 in this scaffold. Furthermore, the cytotoxicity and biocompatibility of UPB scaffold was assessed in vitro. A W1/O/W2 method was used to fabricate PLGA-rhBMP2 microspheres, and then the microspheres were added to UPPE for synthesizing UPB scaffold. The morphological characters of PLGA-rhBMP2 microspheres and UPB scaffolds were observed under the scanning electron microscopy and laser scanning confocal microscopy. The cumulative release of UPB scaffolds was detected by using ELISA. The cytotoxicity and biocompatibility of UPB scaffolds were evaluated through examining the adsorption and apoptosis of bone marrow stromal cells (bMSCs) seeded on the surface of UPB scaffolds. The bioactivity of rhBMP2 in UPB scaffolds was assessed through measuring the alkaline phosphates (ALP) activity in bMSCs seeded. The results showed that UPB scaffolds sequentially exhibited burst and sustained release of rhBMP2. The cytotoxicity was greatly reduced when the scaffolds were immersed in buffer solution for 2 h. bMSCs attached and grew on the surface of soaked UPB scaffolds, exerting well biocompatibility. The ALP activity of bMSCs seeded was significantly enhanced, indicating that the bioactivity of rhBMP2 remained and still took effect after the unfavorable polymerization process of scaffolds. It was concluded that UPB scaffolds have low cytotoxicity, good biocompatibility and preserve bioactivity of rhBMP2. UPB scaffolds are promising in improving bone regeneration.
Bone Morphogenetic Protein 2 ; chemistry ; pharmacology ; Bone Regeneration ; drug effects ; Humans ; Lactic Acid ; chemistry ; pharmacology ; Phosphatidylinositol Phosphates ; chemistry ; pharmacology ; Polyglycolic Acid ; chemistry ; pharmacology ; Tissue Scaffolds

OBJECTIVETo study the feasibility of osteogenic phenotype expression by human skin fibroblasts induced in polyglycolic acid (PGA) foams and the effect of tumor necrosis factor-alpha (TNF-alpha) on the expression of bone morphogenetic protein (BMP) receptors.

METHODSThe fibroblasts were isolated, purified from human skin. (1) Fibroblasts were seeded onto PGA foams. The cell-PGA complexes were cultured in RCCS for 6 weeks, in the media of TNF-alpha (50 U/ml) and BMP-2 (0.1 microg/ml). 1 d, 3 and 6 weeks later, cells and extracellular matrix were investigated by electron microscopic and histochemistry observation respectively. Secretion of osteogenic markers were analyzed by biochemical methods. (2) Fibroblasts were seeded on the glass fragments or culture flasks and treated with TNF-alpha (50 U/ml) in different usage (one-time, all-time). The RT-PCR method and the immunohistochemistry fluorescence staining were used to examine the influence of TNF-alpha on the mRNA expression and the protein expression of the type I BMP receptors at 2, 4, 6, 8 d after treatment.

RESULTSFibroblasts seeded on the PGA foams formed 3-dimensional matrix 3 weeks after seeding, which was demonstrated as osteo-tissue by tetracycline labeling and ARS staining. Cells secreted much more bone-specific alkaline phosphatase (B-AKP) and osteocalcin (OCN) into supernatant than the cells that were cultured in the media without TNF-a and BMP2. Eight days after all-time usage, the TNF-alpha (50 U/ml) increased the expression of the mRNA and protein of the type IB BMP receptor.

CONCLUSIONSFibroblasts on 3-D cell-foam structures can express osteoblastic phenotype under certain inducing conditions. The numerous fibroblasts in body would be a promising resource for cell seeds candidate of tissue- engineered bone. TNF-alpha provides the essential condition for BMP2's target effect on fibroblasts, and combined use of TNF-alpha and BMP2 is one of the regulating factors.

Bone Morphogenetic Protein 2 ; Bone Morphogenetic Protein Receptors, Type I ; biosynthesis ; genetics ; Bone Morphogenetic Protein Receptors, Type II ; biosynthesis ; genetics ; Bone Morphogenetic Proteins ; pharmacology ; Cell Culture Techniques ; methods ; Cell Differentiation ; drug effects ; Cells, Cultured ; Drug Synergism ; Fibroblasts ; cytology ; drug effects ; metabolism ; Humans ; Phenotype ; Polyglycolic Acid ; Transforming Growth Factor beta ; pharmacology ; Tumor Necrosis Factor-alpha ; pharmacology

OBJECTIVETo investigate the effect of systematic administration of simvastatin on the bone morphogenetic protein-2 (BMP-2) expression in the periodontal tissue after rat tooth movement and on the relapse of tooth movement.

METHODSOrthodontic tooth movement of upper first molar was performed in 32 rats with coil spring for 21 days. The 32 rats were randomly allocated into 4 groups: negative control group (isotonic saline) and three experimental groups (2.5 mg x kg(-1), 5.0 mg x kg(-1) and 10.0 mg x kg(-1)). The simvastatin started to be administered to the experimental groups 1 day before appliances were removed, and once a day there after for 4 weeks. The negative control group received the isotonic saline only. The interdental distance between the first and second maxillary molars were measured, when appliances were removed, and 1 week and 4 weeks after that. After the rats were sacrificed, sections of first maxillary molar and periodontal tissue were studied by immunohistochemistry.

RESULTSThe number and percentage of relapse was lower in the three experimental groups than in the negative control group (P < 0.05, P < 0.01). The lower dose was given, the less relapse there was, with the lowerest dose resulting in lowest percentage of relapse (26.81% and 53.38%). BMP-2 expression in experimental groups was higher than in the negative control group, with the lowerest dose group showing the highest expression (P < 0.001). The BMP-2 expression on the tension side was slightly stronger than that on the compression side (P > 0.05).

CONCLUSIONSSystemic administration of simvastatin could decrease the extent of relapse of the orthodontic-moved tooth in rat, and the lower-dose of simvastatin seemed more effective. The possible mechanism for this may be that simvastatin functions by increasing the expression of BMP-2 in the periodontal tissue, accelerating the osteoblast activity and promoting bone formation.

Animals ; Bone Morphogenetic Protein 2 ; metabolism ; Male ; Periodontium ; drug effects ; metabolism ; Rats ; Rats, Wistar ; Simvastatin ; pharmacology ; Tooth Movement Techniques

OBJECTIVEThis study was designed to investigate the optimal combination of known osteogenic biomaterials with shape conforming struts to achieve calvarial vault reconstruction, using a canine model.

METHODSEighteen adolescent beagles were divided equally into 6 groups. A critical size defect of 6 x 2 cm traversed the sagittal suture. The biomaterials used for calvarial reconstruction were demineralised perforated bone matrix (DBM), recombinant human bone morphogenetic protein-2 (rhBMP2) and autogenous platelet-rich plasma (PRP). The struts used were cobalt chrome (metal) or resorbable plate. The groupings were as follows: 1) DBM + metal, 2) DBM + PRP + metal, 3) DBM + PRP + resorbable plate, 4) DBM + rhBMP2 + metal, 5) DBM + rhBMP2 + PRP + metal, and 6) DBM + rhBMP2 + resorbable plate. Animals were euthanised at 3 months post-surgery. There was no mortality or major complications. Analysis was performed macroscopically, histologically, and with computed tomography (CT).

RESULTSThere was complete bony regeneration in the rhBMP2 groups only. Non-rhBMP2 groups had minimal bony ingrowth from the defect edges and on the dural surface, a finding confirmed by CT scan and histology. PRP did not enhance bone regeneration. Shape conformation was good with both metal and resorbable plate.

CONCLUSIONrhBMP2 but not PRP accelerated calvarial regeneration in 3 months. The DBM in the rhBMP2 groups were substituted by new trabecular bone. Shape molding was good with both metal and resorbable plate.

Animals ; Biocompatible Materials ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; pharmacology ; Bone Regeneration ; physiology ; Dogs ; Models, Animal ; Postoperative Care ; Recombinant Proteins ; pharmacology ; Reconstructive Surgical Procedures ; Skull ; growth & development ; pathology ; surgery ; Transforming Growth Factor beta ; pharmacology

BACKGROUNDThe recombinant human bone morphogenetic protein 2 (rhBMP-2) has been used to induce osteogenesis in animals' middle ear and this technique is possible to be used to reconstruct the defects of ossicles. The side effects of the rhBMP-2 in middle ear should be observed before using in clinic. Thus we prepared the controlled release rhBMP-2 and implanted it into the acoustic bulla of guinea pigs. The effect on the cochlea was observed.

METHODSWe prepared the acellular cancellous bone, accompanied with rhBMP-2. The material accompanied with rhBMP-2 was implanted into one acoustic bulla of the animal and the opposite side of the acoustic bulla was implanted with acellular cancellous bone without rhBMP-2. Totally 20 guinea pigs were undergone this procedure. After the operation, the auditory brainstem response (ABR) of the animals was tested according to the time sequence. Three months after the operation, the animals were sacrificed. The osteogenesis induced by rhBMP-2, the acoustic bulla and cochlea affected by rhBMP-2 were observed. The structures of hair cells were observed after silver nitrate staining.

RESULTSThe animals were recovered soon after surgery. The hearing thresholds of the animals were declined slightly just after the surgery and come back completely after 3 months. Also, the bulla and cochlea were normal in shape. The osteogenesis occurred in the pore of the acellular cancellous bone with rhBMP-2. There was not any abnormal hyperplasia of bone in the bulla and cochlea. The articulation between the stapes and oval window was not merged. The shapes of the hair cells were normal and there was no obvious deletion of the hair cells compared with control group.

CONCLUSIONSThe controlled release rhBMP-2 transplanted into the middle ear could induce osteogenesis in the bulla of the animals. It did not affect the shape of the bulla and the hearing threshold of the animal, and did not induce the abnormal hyperplasia of bone in the bulla and might be used to reconstruct the defects of ossicles.

Animals ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; pharmacology ; Bone Regeneration ; drug effects ; Cochlea ; physiopathology ; surgery ; Cochlear Implants ; Ear Ossicles ; metabolism ; Guinea Pigs ; Humans ; Osteogenesis ; drug effects ; Recombinant Proteins ; pharmacology ; Transforming Growth Factor beta ; pharmacology