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

INTRODUCTION: This study examined the effect of recombinant human bone morphogenetic protein (rhBMP)-2 and beta-tricalcium phosphate (beta-TCP) on new bone formation in a rabbit calvarium using a rapid prototype titanium cap (RP Ti cap). MATERIALS AND METHODS: Eight New Zealand white rabbits were used in this study. Hemispherical RP Ti caps (10 mm in diameter) were implanted subperiosteally on the rabbit calvaria. beta-TCP was filled in the RP Ti cap in the control group, and rhBMP-2 soaked beta-TCP was used in experimental group. The rabbits were sacrificed 2 and 4 weeks after the operation. The volume and pattern of newly formed bone was analyzed by micro computed tomography (CT). RESULTS: Macroscopically, there were no abnormal findings in any of the animals. The micro CT images revealed new bone from the calvaria that expanded gradually toward the top of the titanium cap, particularly along the inner surface of the titanium cap in the experimental group at 4 weeks after grafting. There was no significant difference in new bone volume ratio between the control and experimental groups at 2 weeks after grafting. There was a statistically significant difference in the new bone volume ratio between the experimental (14.1+/-1.8 %) and control (7.2+/-1.5 %) groups at 4 weeks after grafting (P<0.01). CONCLUSION: The RP Ti cap can effectively guide new bone formation and rhBMP-2 can induce the new bone formation.
Animals ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; Calcium Phosphates ; Humans ; Osteogenesis ; Rabbits ; Skull ; Titanium ; Transplants

The efficacy of bone morphogenetic proteins (BMP) in infection has not yet been established. Since fusion is a necessary aim in the treatment of vertebral osteomyelitis with spinal instability, BMP may be a helpful adjunct in the surgical treatment of these cases. We present a case of vertebral osteomyelitis associated with neurologic deficits, treated with decompression and fusion using recombinant human bone morphogenetic protein-2 (rhBMP-2) and titanium cage device. Eradication of infection, recovery of neurologic deficits, spinal stabilization and solid fusion were achieved and maintained at 5 years follow-up.

Human ; Female ; Aged ; Recombinant Human Bone Morphogenetic Protein-2 ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; Transforming Growth Factor Beta ; Recombinant Proteins ; Osteomyelitis

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

OBJECTIVEThis research explores the regulatory role of bone morphogenetic protein 2 (BMP2) in the expression of sclerostin in OCCM-30 cementoblast.

METHODSOCCM-30 cementoblasts were treated with 50 and 100 ng · mL⁻¹ BMP2 for 3, 5, and 7 days. SOST mRNA was detected by real-time quantitative polymerase chain reaction (RT-PCR). Western blot analysis was employed to detect the sclerostin levels in the nucleus. Five groups were prepared for the experiments: control, BMP2, BMP2+dorsomorphin, BMP2+SB202190, and BMP2+PD98059. OCCM-30 was pretreated with BMP2 for 3 and 5 days, and then the sclerostin and SOST mRNA levels were measured.

RESULTSRT-PCR and Western blot analyses showed that BMP2 upregulated the expression of SOST in a concentration-dependent manner. SOST expression increased with time (P < 0.05). Moreover, sclerostin levels of BMP2+dorsomorphin, BMP2+SB202190, and BMP2+PD98059 groups were lower than that of the BMP2 group, and the sclerostin level in BMP2+dorsomorphin group was lowest (P < 0.05).

CONCLUSIONThe upregulation of SOST by BMP2 in OCCM-30 is mainly mediated by the BMP2/Smad signal pathway.

Blotting, Western ; Bone Morphogenetic Protein 2 ; metabolism ; Bone Morphogenetic Proteins ; metabolism ; Dental Cementum ; metabolism ; Genetic Markers ; Signal Transduction ; Up-Regulation

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

PURPOSE: The aim of this study was to assess the possible paracrine effect of bone morphogeneticprotein-2 (BMP-2) at the experimental site on the adjacent control site for validating a rabbit calvarial defect model as a means of verifying the effect of BMP-2. METHODS: Sixteen rabbits were divided into two groups (n=8 in each) according to whether or not BMP-2 would be used. Two circular defects (8 mm in diameter) were created side by side, 2 mm apart, in the calvarium of all of the rabbits. In each animal, one of the defects was grafted with either BMP-2-loaded carrier or carrier material alone. The control defects adjacent to these grafted defects, designated CB (the nongrafted defect adjacent BMP-2-loaded carrier-grafted defect) and CC (the nongrafted defect adjacent to carrier only-grafted defect), respectively, were the focus of this study, and were filled only with a blood clot in all of the animals. Histologic observation and histomorphometric analysis were performed at 2 and 8 weeks (n=4 animals per point in time) after surgery. RESULTS: There was no noteworthy difference in the healing pattern, and no statistically significant differences in histomorphometric parameters such as the defect closure, new bone area, or total augmented area between the CC and CB groups. CONCLUSIONS: The results of this study suggest that rabbit calvarial defects separated by a distance of 2 mm are suitable for evaluating the effects of BMP-2 and the control defect can be regarded not to be affected by BMP-2 applied defect.
Animal Experimentation ; Animals ; Bone Morphogenetic Protein 2 ; Bone Regeneration ; Rabbits ; Research Design ; Skull ; Transplants

OBJECTIVE: To measure the concentration of bone morphogenetic protein 2 (BMP-2) in demineralized bone matrix (DBM) prepared from different long bones and to evaluate the osteoinductivity of different DBM on MC3T3-E1 cells. METHODS: Different bones from the same cadaver donor were used as the initial materials for making DBM, which were divided into ulna group (uDBM), humerus group (hDBM), tibia group (tDBM), and femur group (fDBM) according to the origins, and boiled DBM (cDBM) was taken as the control group. The proteins of DBM were extracted by guanidine hydrochloride, and the concentrations of BMP-2 were determined by ELISA assay. Then the DBM were co-cultured with MC3T3-E1 cells, the proliferation of MC3T3-E1 cells was observed by cell counting kit 8 (CCK-8) assay. The osteogenic differentiation ability of MC3T3-E1 cells was qualitatively observed by alizarin red, alkaline phosphatase (ALP), and Van Gieson staining, and the osteogenic differentiation ability of MC3T3-E1 cells was quantitatively analyzed by ALP content. Linear regression was used to analyze the effect of BMP-2 concentration in DBM on ALP synthesis. RESULTS: There were significant differences in the concentration of BMP-2 among the DBM groups (P<0.05). The concentrations of BMP-2 in the lower limb long bone were higher than those in the upper limb long bone, and the concentration of BMP-2 in the fDBM group was about 35.5 times that in the uDBM group. CCK-8 assay showed that the cells in each group continued to proliferate within 5 days of co-culture, and the absorbance (A) values at different time points were in the order of cDBM group2 concentration in DBM. The order of ALP content from low to high was cDBM groupP<0.05). Linear regression analysis showed that y^=0.361+0.017x, the effect of BMP-2 concentration in DBM on cellular ALP content was significant (t=3.552, P=0.005); for every 1 ng/g increase in BMP-2 concentration, ALP content would increase by 0.017 [95%CI (0.006, 0.027)] U/100 mL. CONCLUSION The concentration of natural BMP-2 in different long bones varies greatly, and the lower limb long bone is higher than the upper limb long bone. The harvested location of bone material was an important factor affecting the osteoinductivity of DBM.
Alkaline Phosphatase ; Bone Matrix ; Bone Morphogenetic Protein 2 ; Cell Count ; Coloring Agents ; Osteogenesis ; Animals ; Mice

PURPOSE: The aim of this study was to determine whether biphasic calcium phosphate (BCP) bone substitute with two different concentrations of Escherichia coli-expressed recombinant human bone morphogenetic protein 2 (ErhBMP-2) enhances new bone formation in a standardized rabbit sinus model and to evaluate the concentration-dependent effect of ErhBMP-2. METHODS: Standardized, 6-mm diameter defects were made bilaterally on the maxillary sinus of 20 male New Zealand white rabbits. Following removal of the circular bony windows and reflection of the sinus membrane, BCP bone substitute without coating (control group) was applied into one defect and BCP bone substitute coated with ErhBMP-2 (experimental group) was applied into the other defect for each rabbit. The experimental group was divided into 2 subgroups according to the concentration of ErhBMP-2 (0.05 and 0.5 mg/mL). The animals were allowed to heal for either 4 or 8 weeks and sections of the augmented sinus and surrounding bone were analyzed by microcomputed tomography and histologically. RESULTS: Histologic analysis revealed signs of new bone formation in both the control and experimental groups with a statistically significant increase in bone formation in experimental group 1 (0.05 mg/mL ErhBMP-2 coating) after a 4-week healing period. However, no statistically significant difference was found between experimental group 1 and experimental group 2 (0.5 mg/mL ErhBMP-2 coating) in osteoinductive potential (P<0.05). CONCLUSIONS: ErhBMP-2 administered using a BCP matrix significantly enhanced osteoinductive potential in a standardized rabbit sinus model. A concentration-dependent response was not found in the present study.
Animals ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; Bone Regeneration ; Bone Substitutes ; Calcium ; Durapatite ; Escherichia coli ; Humans ; Hydroxyapatites ; Male ; Maxillary Sinus ; Membranes ; Osteogenesis ; Rabbits ; X-Ray Microtomography