Cáncer colorrectal. Variantes génicas en la vía de señalización BMP y ancestría en población mexicana / Colorectal cancer. Genetic variants in BMP signaling pathway and ancestry in the Mexican population

Resumen Introducción: Variantes génicas relacionadas con la vía de señalización de las proteínas morfogenéticas óseas (BMP2, BMP4, GREM1, SMAD7) se han asociado a cáncer colorrectal, principalmente en poblaciones caucásicas. Objetivo: Describir la asociación de variantes en miembros de la vía BMP en población mexicana, caracterizada por su ancestría indoamericana y caucásica. Métodos: Se realizó el genotipado de 1000 casos de cáncer colorrectal y 1043 individuos de control reclutados en la Ciudad de México, Monterrey y Torreón mediante la plataforma Sequenom. Con análisis univariados y multivariados se estudiaron las asociaciones entre cáncer colorrectal y variantes. Resultados: Las variantes rs4444235, rs12953717 y rs4939827 replicaron la asociación con la neoplasia (p ≤ 0.05). La ascendencia caucásica mostró asociación con el tumor. Conclusiones: El estudio mostró las asociaciones entre cáncer colorrectal y las variantes SMAD7 y BMP4, así como con el componente caucásico de la mezcla étnica.

Abstract Introduction: Genetic variants related to bone morphogenetic proteins (BMP2, BMP4, GREM1, SMAD7) signaling pathway have been associated with colorectal cancer, mainly in Caucasian populations. Objective: To describe the association of variants in members of the BMP signaling pathway in a Mexican population, characterized by its indigenous American and Caucasian ancestry. Methods: Genotyping of 1,000 colorectal cancer cases and 1,043 control individuals recruited in Mexico City, Monterrey, and Torreón was carried out using the Sequenom platform. Associations between colorectal cancer and variants were studied with univariate and multivariate analyses. Results: Variants rs4444235, rs12953717 and rs4939827 replicated the association with the neoplasm (p ≤ 0.05). Caucasian ancestry showed association with the tumor. Conclusions: The study replicated the associations between colorectal cancer and SMAD7 and BMP4 variants, with an association being observed with the Caucasian component of the ethnic mix.

Bone morphogenetic proteins 2, 6, and 9 differentially regulate the osteogenic differentiation of immortalized preodontoblasts

Our study attempted to compare the efficacies of bone morphogenetic protein (BMP) 2, 6, and 9 in inducing osteogenic differentiation of preodontoblasts (PDBs). We immortalized PDBs by introducing a reversible SV40 T antigen-based immortalization system. Cell proliferation capability was examined by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. The effects of BMP2, 6, and 9 on the osteogenic differentiation of immortalized preodontoblasts (iPDBs) were measured by alkaline phosphatase (ALP) activity assays and alizarin red S staining. The expression of osteogenic markers was evaluated by semiquantitative real-time polymerase chain reaction analysis. To assess ectopic bone formation, rat-derived iPDBs were transfected in culture with adenoviral vectors designated Ad-BMP2, 6, and 9 and subcutaneously or intramuscularly injected into mice. Several BMPs retained endogenous expression in PDBs and regulated the mRNA expression of mineralized tissue-associated proteins. ALP activity and mineralized nodule formation were significantly increased in the Ad-BMP9-transfected group relative to the control group. In addition, the most significant hard tissue formation was in this group. The results indicated that BMP signaling was involved in the osteogenic differentiation of iPDBs. BMP9 could be an efficacious accelerant of the osteogenic differentiation of iPDBs.

Serum sclerostin levels in chronic otitis media with and without cholesteatoma

SUMMARY OBJECTIVE Sclerostin is a glycoprotein that plays a catabolic role in bone and is involved in the regulation of bone metabolism by increasing the osteoclastic bone resorption. In this study, serum sclerostin levels were measured in chronic otitis media (COM) with and without cholesteatoma, assuming that it might have a role in the aetiopathogenesis of bone resorption. METHODS A total of 44 patients with cholesteatomatous COM (cCOM) (n = 22) and non-cholesteatomatous COM (ncCOM) (n = 22) were included in this study, and 26 healthy volunteers without any chronic ear disease problem(s) constituted the control group (n = 26). RESULTS No significant difference was not found in terms of serum iPTH, ALP, and vitamin D levels between ncCOM, cCOM, and the control groups. A significant difference was found in terms of serum sclerostin, Ca, and P levels between ncCOM, cCOM, and the control groups (p<0.05). Serum sclerostin levels in the study groups were significantly higher but their serum Ca and P levels were significantly lower compared to the control group. CONCLUSION We think that serum sclerostin concentrations, which were significantly higher in patients with cCOM and ncCOM compared to healthy controls are associated with bone erosion. There is a need for further studies with larger samples in order to determine the relationship between sclerostin and bone erosion in cholesteatoma to help in establishing preventive measures against cholesteatoma and set new targets for the development of non-surgical treatments.

RESUMO OBJETIVO A esclerostina é uma glicoproteína que desempenha um papel catabólico no osso e também envolve a regulação do metabolismo ósseo, aumentando a reabsorção óssea osteoclástica. Neste estudo, os níveis séricos de esclerostina foram medidos em otite média crônica (OMC) com e sem colesteatoma, e presumiu-se se que ela poderia ter um papel na etiopatogênese da reabsorção óssea. MÉTODOS Um total de 44 pacientes com otite média crônica colesteatomatosa (OMCc) (n=22), não colesteatomatosa (OMCnc)(n=22) foram incluídos neste estudo, e 26 voluntários saudáveis e sem doenças crônicas do ouvido constituíram o grupo de controle (n=26). RESULTADOS Não foi encontrada diferença significativa em termos de níveis séricos de iPTH, ALP e vitamina D entre OMCnc, OMCc e o grupo de controle. Foi encontrada uma diferença significativa em termos de níveis séricos de esclerostina, Ca e P entre OMCnc, OMCc e o grupo de controle (p<0,05). Os níveis séricos de esclerostina nos grupos de estudo foram significativamente mais altos, mas os níveis séricos de Ca e P foram significativamente mais baixos em comparação com o grupo de controle. CONCLUSÃO Acreditamos que as concentrações séricas de esclerostina, significativamente maiores em pacientes com OMCc e OMCnc em relação aos controles saudáveis, estão associadas à erosão óssea. Há necessidade de mais estudos com amostras maiores para determinar a relação entre esclerostina e erosão óssea no colesteatoma, já que essas pesquisas podem ajudar a estabelecer medidas preventivas contra o colesteatoma e novas metas para o desenvolvimento de tratamentos não cirúrgicos.

Postulated release profile of recombinant human bone morphogenetic protein-2 (rhBMP-2) from demineralized dentin matrix

Demineralized dentin matrix (DDM) has been used as a recombinant human bone morphogenetic protein-2 (rhBMP-2) carrier in many clinical trials. To optimize the clinical safety and efficacy of rhBMP-2 with DDM, efforts have been made to improve the delivery of rhBMP-2 by 1) lowering the administered dose, 2) localizing the protein, and 3) prolonging its retention time at the action site as well as the bone forming capacity of the carrier itself. The release profile of rhBMP-2 that is associated with endogenous BMP in dentin has been postulated according to the type of incorporation, which is attributed to the loosened interfibrillar space and nanoporous dentinal tubule pores. Physically adsorbed and modified, physically entrapped rhBMP-2 is sequentially released from the DDM surface during the early stage of implantation. As DDM degradation progresses, the loosened interfibrillar space and enlarged dentinal tubules release the entrapped rhBMP-2. Finally, the endogenous BMP in dentin is released with osteoclastic dentin resorption. According to the postulated release profile, DDM can therefore be used in a controlled manner as a sequential delivery scaffold for rhBMP-2, thus sustaining the rhBMP-2 concentration for a prolonged period due to localization. In addition, we attempted to determine how to lower the rhBMP-2 concentration to 0.2 mg/mL, which is lower than the approved 1.5 mg/mL.

rhBMP in lumber fusion for lumbar spondylolisthesis: A systematic review and meta-analysis / 中华创伤杂志(英文版)

PURPOSE@#To compare the efficacy and safety of recombinant human bone morphogenetic protein (rhBMP) and iliac crest autograft in the fusion treatment of lumbar spondylolisthesis.@*METHODS@#The studies using randomized controlled trials to compare the rhBMP with iliac crest autograft in the treatment of lumbar spondylolisthesis were retrieved from Embase, Pubmed, ProQuest dissertations & theses (PQDT), China national knowledge infrastructure (CNKI), Chinese Biomedical Database, Wanfang Data, Cochrane Library (from March 1998 to March 2018). Postoperative fusion rate, clinical success rate, postoperative intervertebral height, complications, operation time, blood loss and duration of hospitalization were chosen as the outcome indicators. Methodological quality of the trials was critically assessed, and relevant data were extracted. Statistical software Revman 5.3 was used for data-analysis.@*RESULTS@#Eleven articles were included in the meta-analysis. The results showed that, comparing the efficacy of rhBMP with iliac crest autograft, statistical significance was found in the 24-month fusion rate post operation [95% CI (1.38, 24.70), p = 0.02] and operation time [95% CI (-14.22, -2.08), p = 0.008]. There is not sufficient evidence for statistical differences in the remaining indicators.@*CONCLUSION@#The current literature shows rhBMP is a safe and effective grafting material in the treatment of lumbar spondylolisthesis. Further evidence is dependent on the emergence of more randomized controlled trials with higher quality and larger sample sizes in the future.

Research of simulated microgravity regulate MC3T3-E1 cells differentiation through the nuclear factor-kappa B signaling pathway / 生物医学工程学杂志

In this study, we aim to investigat the effect of microgravity on osteoblast differentiation in osteoblast-like cells (MC3T3-E1). In addition, we explored the response mechanism of nuclear factor-kappa B (NF-κB) signaling pathway to "zero- " in MC3T3-E1 cells under the simulated microgravity conditions. MC3T3-E1 were cultured in conventional (CON) and simulated microgravity (SMG), respectively. Then, the expression of the related osteoblastic genes and the specific molecules in NF-κB signaling pathway were measured. The results showed that the mRNA and protein levels of alkaline phosphatase (ALP), osteocalcin (OCN) and type Ⅰ collagen (CoL-Ⅰ) were dramatically decreased under the simulated microgravity. Meanwhile, the NF-κB inhibitor α (IκB-α) protein level was decreased and the expressions of phosphorylation of IκB-α (p-IκB-α), p65 and phosphorylation of p65 (p-p65) were significantly up-regulated in SMG group. In addition, the IL-6 content in SMG group was increased compared to CON. These results indicated that simulated microgravity could activate the NF-κB pathway to regulate MC3T3-E1 cells differentiation.

Effects of joint application of all-trans retinoic acid and bone morphogenetic protein on the expression of osteocalcin and osteogenic genes in different cells / 解放军医学杂志

[Abstract] Objective To investigate the effects of exclusive or joint application of all-trans retinoic acid (ATRA) and bone morphogenetic proteins (BMPs) on the osteocalcin (OCN) in mouse osteogenic precursor cells (MC3T3-E1) and bone marrow mesenchymal stem cells (BMSCs), and on the expressions of osteogenesis-related genes ALP, OCN and Runx2. Methods MC3T3-E1 cells and BMSCs were subcultured and stimulated with different concentrations of cytokines, and then divided into ten groups: control group, ATRA group, 5ng/ml BMP2/7 group, 50ng/ml BMP2/7 group, 5ng/ml BMP2 group, 50ng/ml BMP2 group, ATRA+5ng/ml BMP2/7 group, ATRA+50ng/ml BMP2/7 group, ATRA+5ng/ml BMP2 group, and ATRA+50ng/ml BMP2 group. The morphology of the cells was observed by immunofluorescence staining. The OCN expressions in the two kinds of cells were detected by ELISA. The expressions of ALP, OCN and Runx2 genes were detected by RT-qPCR. Results Immunofluorescence staining showed that the cells grew well and were structurally intact. Exclusive use of ATRA obviously inhibited the expressions of OCN in both MC3T3-E1 and BMSCs. On the 7th day, for MC3T3-E1 cells: ATRA alone group [(20.97±0.31)ng/ml] significantly decreased than control group [(33.45±0.55)ng/ml]; for BMSCs: ATRA alone group [(9.90±0.16)ng/ml] significantly decreased than control group [(14.30±0.53)ng/ml] (P<0.05). Exclusive application of BMPs promoted OCN expression in a concentration-dependent manner, and BMP2/7 showed a more strong promoting role. The OCN content in MC3T3-E1 cells treated with 50ng/ml BMP2/7 was (47.13±0.59)ng/ml, and in BMSCs was (49.92±0.53)ng/ml. 50ng/ml BMP2/7 completely antagonized the inhibitory effect of ATRA on cell OCN expression (P<0.05). RT-qPCR test showed that, for MC3T3-E1: ATRA alone significantly inhibited the expressions of ALP and OCN gene (P<0.05), but promoted the expression of Runx2 gene (P<0.05). BMPs alone promoted the expression of osteogenesis-related genes in a concentration-dependent manner (P<0.05). ATRA significantly inhibited the promoting role of BMPs on the OCN gene expression, but ATRA and 50ng/ml BMP2/7 synergistically promoted the expression of ALP gene (P<0.05); for BMSCs: ATRA alone significantly promoted the expression of Runx2 gene on the 7th day, but inhibited the expressions of ALP and OCN gene (P<0.05). 50ng/ml BMPs alone significantly promoted the expressions of ALP and Runx2 genes (P<0.05). 50ng/ml BMP2/7 antagonized the inhibitory effect of ATRA on ALP gene expression and promoted its expression (P<0.05). Conclusions ATRA alone may inhibit the expression of OCN in cells, and inhibits the expressions of ALP and OCN genes in cells; and BMP2/7 may significantly promote the expression of OCN in cells, and may promote the expression of osteogenesis-related genes; and 50ng/ml BMP2/7 may completely antagonize the osteogenic inhibition of ATRA on cells.

Autologous platelet gel-collagen biologically active composite membrane for repair of periodontal bone defect in rats / 中国组织工程研究

BACKGROUND: In recent years, the development of tissue engineering has provided a new approach for the treatment of periodontal bone defect. Tissue engineering therapy includes seed cells, scaffolds and growth factors. Platelet gel contains a large number of platelet growth factors, and collagen is often used for the preparation of scaffold materials. Therefore, the platelet gel and collagen biologically active composite membrane can provide scaffolds and growth factors for the defect bone. OBJECTIVE: To investigate the effect of autologous platelet gel-collagen biologically active composite membrane on the repair of periodontal bone defect in rats. METHODS: Forty-two Wistar rats (Shanghai Xipuer-Bikai Experimental Animal Co., Ltd., China) were selected. (1) Collagen was cut into 5 mm×2 mm size, and 10 mL of whole blood was extracted from 6 rats to obtain platelet-rich plasma. Autologous platelet gel-collagen composite membrane was prepared by adding bovine thrombin, calcium chloride and collagen in a certain proportion. Platelets in whole blood and in platelet-rich plasma were detected. The levels of platelet derived growth factor AB, transforming growth factor-β, basic fibroblast growth factor and vascular endothelial growth factor in whole blood and platelet-rich plasma were detected by ELISA. (2) The models of mandibular periosteal defect were established in 36 rats (the size of the bone defect was 5 mm×2 mm, and the root surface cementum was removed) , and randomly divided into two groups. Autologous platelet gel-collagen group placed the autologous platelet gel-collagen composite membrane in the bone defect, and the control group did not place any materials. The hematoxylin-eosin staining of periodontal tissues of rats in each group was analyzed at 2, 4 and 8 weeks after surgery. Rate of new born, new centumum formation, new alveolar bone formation, and new periodontal ligament tissue formation height were measured. The expression of bone morphogenetic protein-2 was detected by immunohistochemical staining. RESULTS AND CONCLUSION: (1) The mean platelet count in platelet-rich plasma was 4.78 times as high as the whole blood, indicating that the number of platelets increased significantly after prepared into platelet-rich plasma (P < 0.05) . The levels of platelet derived growth factor AB, transforming growth factor-β, basic fibroblast growth factor and vascular endothelial growth factor in platelet-rich plasma were 3.10, 3.45, 7.17 and 5.45 times of the whole blood, respectively (P < 0.05) . (2) The results of hematoxylin-eosin staining observed that the rate of new born, new centumum formation, new alveolar bone formation, and new periodontal ligament tissue formation height at 2 weeks in the autologous platelet gel-collagen group showed no significant difference from the control group (P> 0.05) . At 4 and 8 weeks, all above indexes in the autologous platelet gel-collagen group were significantly higher than those in the control group (P < 0.05) . (3) Results of immunohistochemical staining revealed that at 2 weeks, bone morphogenetic protein-2 in the autologous platelet gel-collagen group began to express, and the expression of bone morphogenetic protein-2 was highest at 4 weeks (P < 0.05) , and the positive expression was weakened at 8 weeks (P> 0.05) . (4) Our results clarify that autologous platelet gel-collagen bioactive composite membrane can significantly promote the regeneration of new tooth, which is associated with the expression of bone morphogenetic protein-2, and reduce the repair time after periodontal tissue defect.

Calcium phosphate cement/fibrin glue composite loaded with recombinant human bone morphogenetic protein 2 promotes osteoporotic fracture healing / 中国组织工程研究

BACKGROUND: Bone morphogenetic protein 2 is a most widely studied and osteogenic-inducing bone morphogenetic protein. However, simple bone morphogenetic protein can be diluted by tissue fluid and decomposed by protease after implantation, so it is difficult to maintain sustained drug concentration or play an effective role in bone induction. OBJECTIVE: To observe the effect of repairing osteoporotic fracture through calcium phosphate cement/fibrin glue composite as the carrier of bone morphogenetic protein 2. METHODS: Fifty-four female Sprague-Dawley rats were selected to remove bilateral ovaries for making osteoporosis models. Three months later, the middle femoral fracture models were made, and then randomized into three groups, with 18 rats in each group. Kirschner wire fixation group was injected nothing. The fracture end was injected with 0.5 mL calcium phosphate cement/fibrin glue (composite group) or calcium phosphate cement/fibrin glue loaded with recombinant human bone morphogenetic protein 2 (loaded group) . At 4 and 12 weeks after fracture, X-ray examination, micro-CT examination, biomechanical three-point bending test and pathological observation were performed. RESULTS AND CONCLUSION: (1) The fracture healing score in the loaded group was higher than that in the other two groups (P < 0.05) . (2) The bone volume fraction, trabecular thickness and number of trabeculae at 4 and 12 weeks in the loaded group were higher than those in the other two groups (P < 0.05) , and the trabecular segregation was lower than that in the other two groups (P < 0.05) . (3) The maximum load and stiffness at 4 and 12 weeks in the loaded group were higher than those in the other two groups (P < 0.05) , and the elastic modulus at 4 weeks after fracture was higher than that in the other two groups (P < 0.05) . (4) Fibrocartilage callus was mainly seen at 4 weeks after fracture in the Kirschner wire fixation group, and the callus was reconstructed into lamellar bone at 12 weeks after fracture with less callus content. Obvious fibrocartilage callus appeared at 4 weeks after fracture in the composite and loaded groups, and the callus was reconstituted into a plate-like bone at 12 weeks. (5) These results imply that the calcium phosphate cement/fibrin glue composite loaded with recombinant human bone morphogenetic protein 2 can promote the healing of osteoporotic fracture and improve bone strength.

Activin A/BMP2 Chimera (AB204) Exhibits Better Spinal Bone Fusion Properties than rhBMP2

OBJECTIVE: To compare the spinal bone fusion properties of activin A/BMP2 chimera (AB204) with recombinant human bone morphogenetic protein (rhBMP2) using a rat posterolateral spinal fusion model. METHODS: The study was designed to compare the effects and property at different dosages of AB204 and rhBMP2 on spinal bone fusion. Sixty-one male Sprague-Dawley rats underwent posterolateral lumbar spinal fusion using one of nine treatments during the study, that is, sham; osteon only; 3.0 μg, 6.0 μg, or 10.0 μg of rhBMP2 with osteon; and 1.0 μg, 3.0 μg, 6.0 μg, or 10.0 μg of AB204 with osteon. The effects and property on spinal bone fusion was calculated at 4 and 8 weeks after treatment using the scores of physical palpation, simple radiograph, micro-computed tomography, and immunohistochemistry. RESULTS: Bone fusion scores were significantly higher for 10.0 μg AB204 and 10.0 μg rhBMP2 than for osteon only or 1.0 μg AB204. AB204 exhibited more prolonged osteoblastic activity than rhBMP2. Bone fusion properties of AB204 were similar with the properties of rhBMP2 at doses of 6.0 and 10.0 μg, but, the properties of AB204 at doses of 3.0 μg exhibited better than the properties of rhBMP2 at doses of 3.0 μg. CONCLUSION: AB204 chimeras could to be more potent for treating spinal bone fusion than rhBMP2 substitutes with increased osteoblastic activity for over a longer period.

Effects of fingolimod on sphingosine-1-phosphate signal in osteoclasts / 中华创伤骨科杂志

Objective To study the effects of fingolimod (FTY720) on the sphingosine-1-phosphate (S1P) signaling pathway in osteoclasts.Methods Murine RAW 264.7 macrophages were induced into osteoclasts by dexamethasone and 1 α,25-(OH)2VitD3 and identified by tartrate resistant acid phosphatase Trp staining.After the osteoclasts were divided into 2 groups,the experimental group was treated with 400 ng/mL FTY720-P while the control group was not.The signal expression of extracellular signal-regulated kinase 1 (ERK1),caspase9 and protein kinase(PKC) in the downstream of S1 P pathway was detected at the gene and protein levels,and the expression of bone morphogenetic protein-2(BMP-2) and transforming growth factor-β1 (TGF-β1),which are closely related to bone reconstruction,was detected.Results The RAW264.7 cells were successfully induced into osteoclasts identified by trataric acid phosphatase staining kit (TRAP).The expression of S1PR1 in osteoclasts was higher than that in other S1PRs.After culture for 48 hours,the expression of PKC mRNA in the experimental group was significantly lower than that in the control group while the expression of BMP-2 mRNA and TGF-[β1 mRNA was significantly increased in the experimental group than in the control group (P ＜ 0.05).However,there were no significant differences in expression of ERK1 mRNA or caspase9 mRNA between the 2 groups(P ＞ 0.05).Conclusions FTY720-P can affect the expression of PKC signal in the downstream of osteoclasts by affecting S1P signaling pathway,mainly by binding to S1PR1 signal pathway,and can also promote the expression of TGF-[β1 and BMP-2 in osteoclasts,ultimately affecting the function of osteoclasts.

Regulatory effects of LASP1 and ferritin on rhBMP2-induced osteogenic differentiation of bone marrow mesenchymal stem cells / 中华创伤骨科杂志

Objective To clarify the function of LIM and SH3 domain protein-1 (LASP1) and ferritin in rhBMP2-induced osteogenic differentiation of beagle bone marrow mesenchymal stem cells (BMSCs).Methods After BMSCs from 3-18-month-old C57BL/6J mice were cultured adherently for 24 hours,they were subjected to osteogenic differentiation for 7,14 and 21 days in 3 groups.BMP2 (100 μg/L) and osteogenic differentiation medium was added in the experimental group,only osteogenic differentiation medium was added in the control group,and nothing was added in the blank group.Osteoblast differentiation was determined by examining marker genes (Runx2,OSX,OCN and OPN) using qRT-PCR.The protein expression of both LASP1 and ferritin was investigated using western blotting.After LASP1 and ferritin were silenced in the cells in the experimental group after transfection of shRNA to target LASP1(m),rhBMP2-induced osteogenesis was repeated to verify the roles of LASP1 and ferritin in osteoblast differentiation.Results The qRT-PCR showed successful osteoblast differentiation in the experimental group.Western blotting verified significant down-regulation of LASP1 and up-regulation of ferritin in the experimental group.After the LASP1 gene was silenced,the expression levels of osteoblast differentiation marker genes in the experimental group were higher than those in the control group.Conclusions rhBMP2 can induce mouse BMSCs to differentiate into osteoblasts in a significant manner.Combined with our preliminary research,the present study may confirm that LASP1 and ferritin,which play an important role in regulating cytoskeleton activity and iron metabolism,are critical in the osteogenic differentiation of mouse BMSCs induced by rhBMP2.

Progress in the study on bone morphogenetic protein 2/4 in central nervous system / 中南大学学报(医学版)

As a member of transforming growth factor β (TGF-β) family,bone morphogenetic proteins (BMPs) are multi-functional factors and play critical roles in heart,cartilage,neural development and postnatal bone formation.It has been demonstrated that among the family,BMP2/4 have been reported to be especially important for the developmental and maturation of central nervous system (CNS).It has different,even opposite functions,in certain given circumstances,which could be a potential risk for BMPs' clinical use.

Activin A/BMP2 Chimera (AB204) Exhibits Better Spinal Bone Fusion Properties than rhBMP2

OBJECTIVE: To compare the spinal bone fusion properties of activin A/BMP2 chimera (AB204) with recombinant human bone morphogenetic protein (rhBMP2) using a rat posterolateral spinal fusion model.METHODS: The study was designed to compare the effects and property at different dosages of AB204 and rhBMP2 on spinal bone fusion. Sixty-one male Sprague-Dawley rats underwent posterolateral lumbar spinal fusion using one of nine treatments during the study, that is, sham; osteon only; 3.0 μg, 6.0 μg, or 10.0 μg of rhBMP2 with osteon; and 1.0 μg, 3.0 μg, 6.0 μg, or 10.0 μg of AB204 with osteon. The effects and property on spinal bone fusion was calculated at 4 and 8 weeks after treatment using the scores of physical palpation, simple radiograph, micro-computed tomography, and immunohistochemistry.RESULTS: Bone fusion scores were significantly higher for 10.0 μg AB204 and 10.0 μg rhBMP2 than for osteon only or 1.0 μg AB204. AB204 exhibited more prolonged osteoblastic activity than rhBMP2. Bone fusion properties of AB204 were similar with the properties of rhBMP2 at doses of 6.0 and 10.0 μg, but, the properties of AB204 at doses of 3.0 μg exhibited better than the properties of rhBMP2 at doses of 3.0 μg.CONCLUSION: AB204 chimeras could to be more potent for treating spinal bone fusion than rhBMP2 substitutes with increased osteoblastic activity for over a longer period.

Effects of co-exposure to fluoride and arsenite on transcription levels of bone morphogenetic proteins 2 and runt-related transcription factor 2 genes in bone of rats / 中华地方病学杂志

Objective To investigate the effects of chronic fluoride and arsenic co-exposure on bone morphogenetic proteins 2 (BMP-2) and runt-related transcription factor 2 (Runx2) gene expressions of bone tissue in rats. Methods One hundred and sixty 8-week-old clean-grade Wistar rats weighting (200 ± 50) g were randomly divided into 16 groups by weight via the random number table method of 10 rats in each group by 2 × 4 factorial experimental design (half female and half male), and treated with different doses of fluoride, arsenite and fluoride plus arsenite in deionized water (untreated control group with 0.0 mg/kg fluoride and 0.0 mg/kg arsenite; low-, moderate- and high-fluoride groups were supplemented with 5.0, 10.0 and 20.0 mg/kg fluoride and 2.5, 5.0 and 10.0 mg/kg arsenite) for 6 months. Rats were divided into control (F0.0As0.0), low fluorine (F5.0As0.0), moderate fluorine (F10.0As0.0), high fluorine (F20.0As0.0), low arsenic (F0.0As2.5), moderate arsenic (F0.0As5.0), high arsenic (F0.0As10.0), low fluorine and low arsenic (F5.0As2.5), low fluorine and moderate arsenic (F5.0As5.0), low fluorine and high arsenic (F5.0As10.0), moderate fluorine and low arsenic (F10.0As2.5), moderate fluorine and moderate arsenic (F10.0As5.0), moderate fluorine and high arsenic (F10.0As10.0), high fluorine and low arsenic (F20.0As2.5), high fluorine and moderate arsenic (F20.0As5.0), high fluorine and high arsenic (F20.0As10.0) groups. The concentrations of urinary fluoride (UF) and urinary arsenic (UAs) were determined as exposure biomarkers via the fluoride ion selective electrode method and the flame atomic fluorescence method. The mRNA expressions of BMP-2 and Runx2 were measured with quantitive real-time PCR. Results There were no dental fluorosis found in F0.0As0.0, F0.0As2.5, F0.0As5.0 and F0.0As10.0 groups, and there was a dose-response relationship between the occurrence of dental fluorosis and fluoride doses. Under exposure of fluorine and arsenic combined with high dose of fluorine (20.0 mg/kg), with increasing of arsenic exposure doses, the degree of injury of dental fluorosis increased (χ2 = 9.124, P < 0.05). Compared with F0.0As0.0 (0.99 ± 0.08, 0.99 ± 0.07), the mRNA expressions of BMP-2 (1.01 ± 0.07, 1.06 ± 0.06, 1.21 ± 0.05) and Runx2 (1.03 ± 0.04, 1.24 ± 0.03, 1.33 ± 0.10) in F5.0As0.0, F10.0As0.0, F20.0As0.0 groups were increased with increasing of fluoride doses. Fluoride had a significant effect on mRNA expressions of BMP-2 and Runx2 (F=3.067, 2.927, P<0.05). There was a significant interaction between fluoride and arsenic combination and BMP-2 and Runx2 mRNA expression levels (F = 3.817, 4.802, P < 0.05). Conclusion When rat is co-exposed to fluorine and arsenic, fluorine plays a leading role on BMP-2 and Runx2 mRNA expressions, and arsenic is indirectly involved in fluoride-induced bone toxicity; fluorine and arsenic has a antagonistic effect on BMP-2 and Runx2 mRNA expressions.

Off-label use of rhBMP-2 as bone regeneration strategies in mandibular ameloblastoma unicystic / Utilização off-label das rhBMP-2 como estratégia de regeneração do tecido ósseo em ameloblastoma mandibular

ABSTRACT Jawbone reconstruction after tumor resection is one of the most challenging clinical tasks for maxillofacial surgeons. Osteogenic, osteoinductive, osteoconductive and non-antigenic properties of autogenous bone place this bone as the gold standard for solving problems of bone availability. However, the need for a second surgical site to harvest the bone graft increases significantly both the cost and the morbidity associated with the reconstructive procedures. Bone grafting gained an important tool with the discovery of bone morphogenetic proteins in 1960. Benefit of obtaining functional and real bone matrix without need of second surgical site seems to be the great advantage of use bone morphogenetic proteins. This study analyzed the use of rhBMP-2 in unicystic ameloblastoma of the mandible, detailing its structure, mechanisms of cell signaling and biological efficacy, in addition to present possible advantages and disadvantages of clinical use of rhBMP-2 as bone regeneration strategy.

RESUMO A reconstrução óssea dos maxilares após ressecções tumorais é uma das tarefas mais difíceis para o cirurgião maxilofacial. As propriedades osteogênicas, osteoindutoras, osteocondutoras e não antigênicas do osso autógeno o colocam como o padrão-ouro para a solução de problemas de disponibilidade óssea. Entretanto a coleta do enxerto ósseo necessita de um segundo sítio cirúrgico, aumentando significativamente o custo e a morbidade associados ao procedimento reconstrutivo. A enxertia óssea ganhou uma excelente ferramenta com a descoberta das proteínas ósseas morfogenéticas na década de 1960. O benefício da obtenção de matriz óssea verdadeira e funcional, sem a necessidade de um segundo sítio cirúrgico, parece ser a grande vantagem do uso das proteínas ósseas morfogenéticas. Neste contexto, o objetivo deste estudo foi analisar a utilização da rhBMP-2 na regeneração óssea de ameloblastoma mandibular unicístico, detalhando sua estrutura, seus mecanismos de sinalização celular e sua eficácia biológica, além de apresentar potenciais vantagens e desvantagens da utilização clínica das rhBMP-2, enquanto estratégia regenerativa.

The use of bone morphogenetic proteins (BMP) and pseudarthrosis, a literature review / O uso de proteínas morfogenéticas ósseas (BMP) e pseudoartroses, uma revisão de literatura

ABSTRACT Bone morphogenetic proteins (BMP) are multi-functional growth factors to promote bone healing with the proposal of less morbidity compared to the usual methods of bone graft harvest. Pseudoarthrosis occur when the fusion attempt fails, a solid fusion is not achieved, or there is motion across the segment leading to it, and it can be clinically symptomatic as pain, deformity, neurocompression, or hardware failure. BMPs are used at spinal fusion as a tool for the treatment of degenerative, traumatic, neoplastic and infectious conditions of the spine. This review shows that the use of BMPS is effective and secure when compared with iliac crest bone graft (ICGB); however, depending of the location of usage (cervical spine, lumbar spine or sacrum) and the medical status of the patient (presence of comorbidities, tobacco usage), it is more likely to exhibit complications. Therefore, the use of these proteins must be an informed decision of patient and physician preferences.

RESUMO Proteínas morfogenéticas do osso (Bone morphogenetic proteins [BMP]) são fatores de crescimento multifuncionais que promovem cicatrização óssea, propõem menos comorbidades comparada com os métodos usuais de colheita de enxerto ósseo. Pseudoartroses ocorrem quando a tentativa de fusão óssea falha, uma fusão sólida não é atingida ou quando há movimentação do segmento que leva à pseudoartrose, que pode ser clinicamente sintomática com dor, deformidade, neurocompressão ou falha na colocação de material de síntese. As BMPs são usadas em fusão colunar como ferramenta para o tratamento de trauma degenerativo, condições neoplásicas e infecciosas da coluna. A presente revisão da literatura mostra que o uso de BMPs é efetivo e seguro quando comparado com enxerto ósseo ilíaco. No entanto, a depender do local de uso (coluna cervical ou lombar ou sacro) e do estado médico do paciente (presença de comorbidades, tabagismo), é mais propício o aparecimento de complicações. Portanto, o uso dessas proteínas deve ser efetivado após uma decisão conjunta de preferências médicas e do paciente.

Nano-hydroxyapatite/silk fibroin composite materials loaded with recombinant human bone morphogenetic protein 2 used for spinal fusion / 中国组织工程研究

BACKGROUND:With the wide application of bone repair scaffold in the field of medicine, nano-hydroxyapatite (nHA) and silk fibroin (SF) both of which have good biological properties have become research hotspots in recent years.OBJECTIVE:To study the feasibility of nHA/SF composite materials loaded with recombinant human bone morphogenetic protein 2 (rhBMP-2) to restore the initial stability of the spinal segment in rabbits.METHODS: Thirty-six male health New Zealand rabbits were randomly divided into three groups, followed by preparation of spinal instability models. Autogenous iliac bone, nHA/SF composite, and rhBMP-2/nHA/SF composite were implanted into the L4/5 spinal segment in autologous bone group, nHA/SF group and rhBMP-2/nHA/SF group, respectively. X-ray exmaination was performed at 12 weeks postoperatively, and then the animals were killed for gross observation. The stability of the fusion segments was tested through a tensile machine. Histologically, bone graft fusion at the surgical site was observed.RESULTS AND CONCLUSION:(1) Findings from the gross specimen observation showed that the specimens at the fusion site presented with a hard texture. Obvious signs of fusion were visible in the autologous bone group, followed by the rhBMP-2/nHA/SF group, while no signs of fusion were detected in the nHA/SF group. (2) At 12 weeks postoperatively, a large number of trabecular bones grew into the boundary between the vertebral body and the iliac crest graft block in the autologous bone group. A little trabecular bone was found in the boundary in the nHA/SF group, while a lot of trabecular bone tissues were found in the boundary in the rhBMP-2/nHA/SF group. In accordance with the standard of fusion, there were 10, 3, and 9 rats in the autologous bone, nHA/SF and rhBMP-2/nHA/SF groups, respectively. (3) The range of motion of the spine in the rhBMP-2/nHA/SF showed no statistical difference from that in the autologous bone group, but was significantly higher than that in the nHA/SF group (P < 0.05). (4) Osseous connection was found around the bone graft in the autologous bone and nHA/SF groups, but no mature bone tissue was visible in the latter group. In the rhBMP-2/nHA/SF group, a large number of new capillaries was found and permeated into the spinal tissues. In summary, nHA/SF composite materials loaded with rhBMP-2 possess good biocompatibility, mechanical properties and bone induction ability, which can rebuild the initial stability of the spine in a short time.

Smad4-dependent TGF-β directly up-regulates Notch4 in cerebrovascular endothelial cells / 军事医学

Objective To find out whether NOTCH receptors can serve as direct downstream targets of transforming growth factor β(TGF-β)/Smad4 signaling in endothelial cells.Methods Real-time PCR and Western blotting were performed to verify whether the expression of notch1 and notch4 was regulated by TGF-β pathway.Luciferase reporter assay was employed to investigate how the promoter of notch1 and notch4 was regulated by TGF-β.Then, ChIP assay was used confirm whether the promoter of notch1 and notch4 physically interacted with SMAD protein.Results TGF-β1 and bone morphogenetic protein 4 (BMP4) treatment increased the expression of both notch1 and notch4 at the transcriptional level.In addition, SMAD4 was physically associated with the SMAD binding sites on the notch4 promoter, which was largely enhanced under the treatment of TGF-β1 and BMP4.Importantly, TGF-β1 and BMP4 failed to transactivate notch4 in the absence of endogenous SMAD4 or the SMAD binding regions on the notch4 promoter.Conclusion The expression of NOTCH receptor can be directly up-regulated by SMAD4-mediated TGF-β/BMP signaling in cerebrovascular endothelial cells.

Research development of bone morphogenetic protein-4 in the malignant tumor / 中国综合临床

Bone morphogenetic protein-4(BMP4) is one of BMPs member,it not only can play an important role in cell proliferation and invasion,but also play an important role in cell differentiation,apoptosis and angiogenesis.A study showed BMP4 in malignant tumor can inhibit the growth of tumor cells,and also can induce tumor cell invasion,metastasis and epithelial mesenchymal transformation,and SMAD is the classic signaling pathways.BMP4 is expected to become a potential therapeutic targets and in evaluating the prognosis,immune therapy in malignant tumor.In this paper,the structure and function of BMP4 and its mechanism in tumor were reviewed.