Bone morphogenetic protein-4 affects both trophoblast and non-trophoblast lineage-associated gene expression in human embryonic stem cells

Human embryonic stem cells (hESC) can be induced to differentiate to trophoblast by bone morphogenetic proteins (BMPs) and by aggregation to form embryoid bodies (EB), but there are many differences and controversies regarding the nature of the differentiated cells. Our goals herein were to determine if BG02 cells form trophoblast-like cells (a) in the presence of BMP4-plus-basic fibroblast growth factor (FGF-2) and (b) upon EB formation, and (c) whether the BMP4 antagonist noggin elicits direct effects on gene expression and hormone production in the cells. Transcriptome profiling of hESC incubated with BMP4/FGF-2 showed a down-regulation of pluripotency-associated genes, an up-regulation of trophoblast-associated genes, and either a down-regulation or no change in gene expression for many markers of the three embryonic germ layers. Yet, there was up-regulation of several genes associated with mesoderm, ectoderm, and endoderm, strongly suggesting that differentiation to trophoblast-like cells under the conditions used does not yield a homogeneous cell type. Several genes, heretofore unreported, were identified that are altered in hESC in response to BMP4-mediated differentiation. The production of human chorionic gonadotropin (hCG), progesterone, and estradiol in the differentiated cells confirmed that trophoblast-like cells were obtained. Gene expression by EB was characterized by an up-regulation of a number of genes associated with trophoblast, ectoderm, endoderm, and mesoderm, and the production of hCG and progesterone confirmed that trophoblast-like cells were formed. These results suggest that, in the presence of FGF-2, BG02 cells respond to BMP4 to yield trophoblast-like cells, which are also obtained upon EB formation. Thus, BMP4-mediated differentiation of hESC represents a viable cell system for studying early developmental events post-implantation;however, up-regulation of non-trophoblast genes suggests a somewhat diverse response to BMP4/FGF-2. Noggin altered the transcription of a limited number of genes but, not surprisingly, did not lead to secretion of hormones.

Effects of bone morphogenetic protein-4 on spatial memory and cholinergic expression in the dentate gyrus after fornix-fimbria transection in rats

BACKGROUND： Previous experiments have confirmed bone morphogenetic proteins （BMPs） upregulate cholinergic expression in neurons isolated from the embryonic rat hippocampus and cerebral cortex. Therefore, BMPs could be useful for treating Alzheimer＇s disease and other neurodegenerative diseases. OBJECTIVE： BMP-4 was infused into the hippocampal dentate gyrus of fomix-fimbria transected rats to test the effects of BMP-4 on cholinergic expression in dentate gyrus neurons, and to observe changes in spatial memory behavior. DESIGN： A randomized controlled animal experiment. SETTING： Department of Neurosurgery and Laboratory for Cell Biology, Institute of Geriatrics, General Hospital of Chinese PLA. MATERIALS： Twenty-seven healthy adult male Sprague Dawley （SD） rats, weighing 250-300 g, were provided by the Laboratory Animal Center of the General Hospital of Chinese PLA. Reagents： BMP-4 （B-2680, Sigma Company） and choline acetyl transferase （CHAT） antibody （AB5042, Chemicon Company） were used in this study. Equipments： a rat stereotaxic instrument （type： SN-2N, Narushige Group, Japan） and Image-prog-plus image analysis software （Media Cybernetics company, USA） were used in this study. The protocol was carried out in accordance with ethical guidelines for the use and care of animals. METHODS： This experiment was performed in the Institute of Geriatrics, General Hospital of Chinese PLA between July 2004 and March 2005. Rats were randomly divided into 4 groups： Alzheimer＇s disease group （n = 7）, normal control group （n = 5）, BMP-4-Alzheimer＇s disease group （n = 8）, and model group （n = 7）. In the Alzheimer＇s disease group, the left hippocampal fomix-fimbria of rats was transected to mimic Alzheimer＇s disease symptoms. In the BMP-4-Alzheimer＇s disease group, 1 μt L BMP-4 （10 mg/L） was perfused into the left dentate gyrus with a microinjector at 1 μ L/min. In the model group, 1 μ L saline was perfused into the same position by the same method. Twenty-eight days after injection, Morris water maze test was performed in all rats to test spatial memory. Time-to-platform and swim-path length were recorded. Immunohistochemical staining of cholinergic neurons was performed on brain sections containing dentate gyrus. The area covered by ChAT-positive cells was analyzed using an Image-prog-plus image analysis software. MAIN OUTCOME MEASURES： Area covered by ChAT-positive cells in the dentate gyrus. Time-to-platform and swim path-length. RESULTS： Twenty-seven rats were included in the final analysis. In the Alzheimer＇s disease group, the area covered by ChAT-positive cells was significantly smaller compared with the normal control group （F = 76.03, P 〈 0.01）. The area covered by ChAT-positive cells was significantly larger in the BMP-4- Alzheimer＇s disease group than in the model group （F = 35.17, P 〈 0.05）, but significantly smaller than in the normal control group （F = 40.17, P 〈 0.05）. Time-to-platform and swim-path length were significantly longer in the Alzheimer＇s disease group than in the normal control group （F =24.62 and 631.58, respectively, both P 〈 0.05）. Time-to-platform and swim-path length were significantly shorter in the BMP4-Alzheimer＇s disease group compared with the model group （F= 22.06 and 606.89, respectively P 〈 0.05）. CONCLUSION： Injection of BMP-4 into the dentate gyrus of Alzheimer＇s disease model rats alleviates central cholinergic system injury and concomitantly improves spatial memory.

Bone morphogenetic protein-6 suppresses TGF-β_(2)-induced epithelial-mesenchymal transition in retinal pigment epithelium

AIM:To evaluate the effect of bone morphogenetic protein-6(BMP-6)on transforming growth factor(TGF)-β_(2)-induced epithelial-mesenchymal transition(EMT)in retinal pigment epithelium(RPE).METHODS:Adult retinal pigment epithelial cell line(ARPE-19)were randomly divided into control,TGF-β_(2)(5μg/L),and BMP-6 small interfering RNA(siRNA)group.The cell morphology was observed by microscopy,and the cell migration ability were detected by Transwell chamber.The EMT-related indexes and BMP-6 protein levels were detected by Western blotting.Furthermore,a BMP-6 overexpression plasmid was constructed and RPE cells were divided into the control group,TGF-β_(2)+empty plasmid group,BMP-6 overexpression group,and TGF-β_(2)+BMP-6 overexpression group.The EMT-related indexes and extracellular regulated protein kinases(ERK)protein levels were detected.RESULTS:Compared with the control group,the migration of RPE cells in the TGF-β_(2) group was significantly enhanced.TGF-β_(2) increased the protein expression levels ofα-smooth muscle actin(α-SMA),fibronectin and vimentin but significantly decreased the protein levels of E-cadherin and BMP-6(P<0.05)in RPE.Similarly,the migration of RPE cells in the BMP-6 siRNA group was also significantly enhanced.BMP-6 siRNA increased the protein expression levels ofα-SMA,fibronectin and vimentin but significantly decreased the protein expression levels of E-cadherin(P<0.05).Overexpression of BMP-6 inhibited the migration of RPE cells induced by TGF-β_(2) and prevented TGF-β_(2) from affecting EMT-related biomarkers(P<0.05).CONCLUSION:BMP-6 prevents the EMT in RPE cells induced by TGF-β_(2),which may provide a theoretical basis for the prevention and treatment of proliferative vitreoretinopathy.

AAV-mediated expression of p65shRNA and bone morphogenetic protein 4 synergistically enhances chondrocyte regeneration

BACKGROUND:Adeno-associated virus(AAV)gene therapy has been proven to be reliable and safe for the treatment of osteoarthritis in recent years.However,given the complexity of osteoarthritis pathogenesis,single gene manipulation for the treatment of osteoarthritis may not produce satisfactory results.Previous studies have shown that nuclear factorκB could promote the inflammatory pathway in osteoarthritic chondrocytes,and bone morphogenetic protein 4(BMP4)could promote cartilage regeneration.OBJECTIVE:To test whether combined application of AAV-p65shRNA and AAV-BMP4 will yield the synergistic effect on chondrocytes regeneration and osteoarthritis treatment.METHODS:Viral particles containing AAV-p65-shRNA and AAV-BMP4 were prepared.Their efficacy in inhibiting inflammation in chondrocytes and promoting chondrogenesis was assessed in vitro and in vivo by transfecting AAV-p65-shRNA or AAV-BMP4 into cells.The experiments were divided into five groups:PBS group;osteoarthritis group;AAV-BMP4 group;AAV-p65shRNA group;and BMP4-p65shRNA 1:1 group.Samples were collected at 4,12,and 24 weeks postoperatively.Tissue staining,including safranin O and Alcian blue,was applied after collecting articular tissue.Then,the optimal ratio between the two types of transfected viral particles was further investigated to improve the chondrogenic potential of mixed cells in vivo.RESULTS AND CONCLUSION:The combined application of AAV-p65shRNA and AAV-BMP4 together showed a synergistic effect on cartilage regeneration and osteoarthritis treatment.Mixed cells transfected with AAV-p65shRNA and AAV-BMP4 at a 1:1 ratio produced the most extracellular matrix synthesis(P<0.05).In vivo results also revealed that the combination of the two viruses had the highest regenerative potential for osteoarthritic cartilage(P<0.05).In the present study,we also discovered that the combined therapy had the maximum effect when the two viruses were administered in equal proportions.Decreasing either p65shRNA or BMP4 transfected cells resulted in less collagen II synthesis.This implies that inhibiting inflammation by p65shRNA and promoting regeneration by BMP4 are equally important for osteoarthritis treatment.These findings provide a new strategy for the treatment of early osteoarthritis by simultaneously inhibiting cartilage inflammation and promoting cartilage repair.

T allele at site 6007 of bone morphogenetic protein-4 gene increases genetic susceptibility to ossification of the posterior longitudinal ligament in male Chinese Han population

Background Several candidate genes of ossification of the posterior longitudinal ligament （OPLL） susceptibility have been identified, but their polymorphisms account for only a small percent of the total variance. Bone morphogenetic protein-4 （BMP4） is a potent ectopic ossification inducing factor. BMP4 protein and mRNA are present in cells from OPLL patients, but not non-OPLL controls. A single nucleotide polymorphism of 6007C〉T（rs17563） of BMP4 has been reported to affect bone density in postmenopausal women. Thus, BMP4 may function in OPLL development. Appropriately, the relationship between BMP4 polymorphisms and OPLL was investigated. Methods A case-control association study investigated the genetic etiology in 179 OPLL patients and 298 non-OPLL controls. Extent of OPLL was analyzed by radiologic examinations. Whether single nucleotide polymorphism （SNP） of -5826G〉A（rs1957860） 5＇ of the transcription start site and 6007C〉T（rs17563） in exon 4 of the BMP4 gene were statistically associated with genetic susceptibility to OPLL in Chinese Han subjects was assessed. Results A significant statistical difference in genotype of 6007C〉T polymorphism between male OPLL patients and male controls was evident, and the frequency of ＂TT＂ genotype in male OPLL patients was significantly higher than in male controls （P=0.039）. The frequency of the ＂T＂ allele was also significantly higher in male OPLL subjects than in male controls （P=0.014, OR=1.57）. A significant difference was also observed between the 6007C〉T polymorphism and the number of ossified cervical vertebrae in OPLL patients, while no statistical difference was apparent between the -5826G〉A polymorphism and OPLL occurrence. Conclusions The T allele in the 6007C〉T polymorphism may be a risk factor for male Han Chinese with ossification of the posterior longitudinal ligament in the cervical spine. Chinese Han male patients with CT and TT 6007C〉T genotypes have a genetic susceptibility to OPLL and more extensive OPLL in the cervical spine.

Improved Osteointegration of Ti-6Al-4V-implants of Different Surface Texture by the Use of Bone Morphogenetic Protein-3 (BMP-3)

Half of altogether 60 cylindrical implant devices made of titanium-aluminum-vanadium alloy （ Ti-6Al-4V） were plusna-sprayed with a hydroxyapatite-couting and the other half had a corundum blasted porous surface. 15 implants of each group of the titanium test buplants were coated with 230 μg porcine, high-purified BMP- 3-precipitute per implant. In each case a BMP- 3-couted and an uncoated control-device were implanted into the femoral part of the putellofemoral joint of the right and left leg of 30 adult giant rabbits. Histomorphological and histomorphometrical we found in both groups with BMP- 3-coated test devices an improved osteointegrution. Stutistical evaluation using the t-test for matched samples showed 5 weeks after surgery a significant higher volume of tony formed bone of the BMP- 3-coated corundum- blasted or hydroxyapathe- coated Ti- 6Al- 4 V test devices compared to the non-couted controls of the same t）pe （p 〈 0.01, t-test for matched samples）. In both implant groups with BMP-couting a synergetic effect was verifiable although the bone ongrowth in the hydroxyaputite coated implants was more extensive than in the corundum blasted implants. Light microscopy demonstrated osteointegrution without connective tissue membrane around the surface of the implants. Our results indicate that composite metal implants,as used in endoprosthetics and implantology , are suitable carriers for BMP- 3 and im proved fixation of the implants can be achieved. The hydroxyapatite surface is superior to the corundum-blasted surface with regards to the observed parameters because of its pronounced bioactivity and its osteoconductive characteristics.

Exogenous bone morphogenetic protein-7 reduces hepatic fibrosis inSchistosoma japonicum-infected micevia transforming growth factor-β/Smad signaling

AIM: To investigate the antifibrotic effects of bone morphogenetic protein-7 (BMP-7) on Schistosoma japonicum (S. japonicum )-induced hepatic fibrosis in BALB/C mice. METHODS: Sixty BALB/C mice were randomly divided into three groups, including a control group (group A, n = 20), model group (group B, n = 20) and BMP-7 treated group (group C, n = 20). The mice in group B and group C were abdominally infected with S. japonicum cercariae to induce a schistosomal hepatic fibrosis model. The mice in group C were administered human recombinant BMP-7. Liver samples were extracted from mice sacrificed at 9 and 15 wk after modeling. Hepatic histopathological changes were assessed using Masson's staining. Transforming growth factor-beta 1 (TGF-β1), alpha-smooth muscle actin (α-SMA), phosphorylated Smad2/3 (pSmad2/3) and Smad7 protein levels and localization were measured by Western blotting and immunohistochemistry, respectively, and their mRNA expressions were detected by reverse transcriptionpolymerase chain reaction (RT-PCR). RESULTS: The schistosomal hepatic fibrosis mouse model was successfully established, as the livers of mice in group B and group C showed varying degrees of typical schistosomal hepatopathologic changes such as egg granuloma and collagen deposition. The degree of collagen deposition in group C was higher than that in group A (week 9: 22.95±6.66vs 2.02±0.76; week 15: 12.84±4.36 vs 1.74±0.80; P<0.05), but significantly lower than that in group B (week 9: 22.95±6.66 vs 34.43±6.96; week 15: 12.84±4.36 vs 18.90±5.07;P<0.05) at both time points. According to immunohistochemistry data, the expressions of α-SMA, TGF-β1 and pSmad2/3 protein in group C were higher than those in group A (α-SMA: week 9: 21.24±5.73 vs 0.33±0.20; week 15: 12.42±4.88 vs 0.34±0.27; TGF-β1: week 9: 37.00±13.74 vs 3.73±2.14; week 15: 16.71±9.80 vs 3.08±2.35; pSmad2/3: week 9: 12.92±4.81 vs 0.83±0.48; week 15: 7.87±4.09 vs 0.90±0.45; P<0.05), but significantly lower than those in group B (α-SMA: week 9: 21.24±5.73 vs 34.39±5.74; week 15: 12.42±4.88 vs 25.90±7.01; TGF-β1: week 9: 37.00±13.74 vs 55.66±14.88; week 15: 16.71±9.80 vs 37.10±12.51; pSmad2/3: week 9: 12.92±4.81 vs 19.41±6.87; week 15: 7.87±4.09vs 13.00±4.98;P<0.05) at both time points; the expression of Smad7 protein in group B was higher than that in group A and group C at week 9 (8.46±3.95 vs 1.00±0.40 and 8.46±3.95 vs 0.77±0.42; P<0.05), while there were no differences in Smad7 expression between the three groups at week 15 (1.09±0.38 vs 0.97±0.42 vs 0.89±0.39; P>0.05). Although minor discrepancies were observed, the results of RT-PCR and Western blotting were mainly consistentwith the immunohistochemical results. CONCLUSION: Exogenous BMP-7 significantly decreased the degree of hepatic fibrosis in both the acute and chronic stages of hepato-schistosomiasis, and the regulatory mechanism may involve the TGF-β/Smad signaling pathway.

Drilling Combined with Adipose-derived Stem Cells and Bone Morphogenetic Protein-2 to Treat Femoral Head Epiphyseal Necrosis in Juvenile Rabbits

This study was designed to evaluate the effects of drilling through the growth plate and using adipose-derived stem cells （ADSCs） and bone morphogenetic protein-2 （BMP-2） to treat femoral head epiphyseal ischemic necrosis, which can be done in juvenile rabbits. Passagefour bromodeoxyuridine （BrdU）-labeled ADSCs were cultured, assayed with MTT to determine their viability and stained with alizarin red dye to determine their osteogenic ability. Twomonth-old, healthy male rabbits （1.2 to 1.4 kg, n=45） underwent ischemic induction and were randomly divided into five groups （group A： animal model control; group B： drilling; group C： drilling ＆ ADSCs; group D： drilling ＆ BMP-2; and group E： drilling ＆ ADSCs ＆ BMP-2）. Magnetic resonance imaging （MRI）, X-ray imaging, hematoxylin and eosin staining and BrdU immunofluorescence detection were applied 4, 6 and 10 weeks after treatment. Approximately 90% of the ADSCs were labeled with BrdU and showed good viability and osteogenic ability. Similar results were observed in the rabbits in groups C and E at weeks 6 and 10. The animals of groups C and E demonstrated normal hip structure and improved femoral epiphyseal quotients and trabecular areas compared with those of the groups A and B （P〈0.01）. Group D demonstrated improved femoral epiphyseal quotients and trabecular areas compared with those of groups A and B （P〈0.05）. In summary, drilling through the growth plate combined with ADSC and BMP-2 treatments induced new bone formation and protected the femoral head epiphysis from collapsing in a juvenile rabbit model of femoral head epiphyseal ischemic necrosis.

Bone morphogenetic protein-2 is a negative regulator of hepatocyte proliferation downregulated in the regenerating liver

AIM: To characterize the expression and dynamic changes of bone morphogenetic protein (BMP)-2 in hepatocytes in the regenerating liver in rats after partial hepatectomy (PH), and examine the effects of BMP-2 on proliferation of human Huh7 hepatoma cells. METHODS: Fifty-four adult male Wistar rats were randomly divided into three groups: A normal control (NC) group, a partial hepatectomized (PH) group and a sham operated (SO) group. To study the effect of liver regeneration on BMP-2 expression, rats were sacrificed before and at different time points after PH or the sham intervention (6, 12, 24 and 48 h). For each time point, six rats were used in parallel. Expression and distribution of BMP-2 protein were determined in regenerating liver tissue by Western blot analysis and immunohistochemistry. Effects of BMP-2 on cell proliferation of human Huh7 hepatoma cell line were assessed using an MTT assay.RESULTS: In the normal liver strong BMP-2 expression was observed around the central and portal veins. The expression of BMP-2 decreased rapidly as measured by both immunohistochemistry and Western blot analysis. This decrease was at a maximum of 3.22 fold after 12 h and returned to normal levels at 48 h after PH. No significant changes in BMP-2 immunoreactivity were observed in the SO group. BMP-2 inhibited serum induced Huh7 cell proliferation.CONCLUSION: BMP-2 is expressed in normal adult rat liver and negatively regulates hepatocyte proliferation. The observed down regulation of BMP-2 following partial hepatectomy suggests that such down regulation may be necessary for hepatocyte proliferation.

Roles and regulation of bone morphogenetic protein-7 in kidney development and diseases

The gene encoding bone morphogenetic protein-7(BMP7) is expressed in the developing kidney in embryos and also in the mature organ in adults. During kidney development, expression of BMP7 is essential to determine the final number of nephrons in and proper size of the organ. The secreted BMP7 acts on the nephron progenitor cells to exert its dual functions: To maintain and expand the progenitor population and to provide them with competence to respond to differentiation cues, each relying on distinct signaling pathways. Intriguingly, in the adult organ, BMP7 has been implicated in protection against and regeneration from injury. Exogenous administration of recombinant BMP7 to animal models of kidney diseases has shown promising effects in counteracting inflammation, apoptosis and fibrosis evoked upon injury. Although the expression pattern of BMP7 has been well described, the mechanisms by which it is regulated have remained elusive and the processes by which the secretion sites of BMP7 impinge upon its functions in kidney development and diseases have not yet been assessed. Understanding the regulatory mechanisms will pave the way towards gaining better insight into the roles of BMP7, and to achieving desired control of the gene expression as a therapeutic strategy for kidney diseases.

Use of recombinant human bone morphogenetic protein-2 in spine surgery

Bone morphogenetic proteins are osteoinductive factors which have gained popularity in orthopaedicsurgery and especially in spine surgery. The use of recombinant human bone morphogenetic protein-2 has been officially approved by the United States Food and Drug Administration only for single level anterior lumbar interbody fusion, nevertheless it is widely used by many surgeons with off-label indications. Despite advantages in bone formation, its use still remains a controversial issue and several complications have been described by authors who oppose their wide use.

Chondrogenesis of periodontal ligament stem cells by transforming growth factor-β3 and bone morphogenetic protein-6 in a normal healthy impacted third molar

The periodontal ligament-derived mesenchymal stem cell is regarded as a source of adult stem cells due to its multipotency.However, the proof of chondrogenic potential of the cells is scarce.Therefore,we investigated the chondrogenic differentiation capacity of periodontal ligament derived mesenchymal stem cells induced by transforming growth factor(TGF)-p3 and bone morphogenetic protein(BMP)-6.After isolation of periodontal ligament stem cells(PDLSCs) from human periodontal ligament,the cells were cultured in Dulbecco’s modified Eagle’s medium(DMEM) with 20%fetal bovine serum(FBS).A mechanical force initiated chondrogenic differentiation of the cells.For chondrogenic differentiation,10μg·LTGF-β3 or 100μg·LBMP-6 and the combination treating group for synergistic effect of the growth factors.We analyzed the PDLSCs by fluorescence-activated cell sorting and chondrogenesis were evaluated by glycosaminoglycans assay,histology,immunohistochemistry and genetic analysis.PDLSCs showed mesenchymal stem cell properties proved by FACS analysis.Glycosaminoglycans contents were increased 217%by TGF-β3 and 220%by BMP-6. The synergetic effect of TGF-β3 and BMP-6 were shown up to 281%compared to control.The combination treatment increased Sox9, aggrecan and collagen II expression compared with not only controls,but also TGF-P3 or BMP-6 single treatment dramatically.The histological analysis also indicated the chondrogenic differentiation of PDLSCs in our conditions.The results of the present study demonstrate the potential of the dental stem cell as a valuable cell source for chondrogenesis,which may be applicable for regeneration of cartilage and bone fracture in the field of cell therapy.

The Effect of Simvastatin on mRNA Expression of Transforming Growth Factor-β1,Bone Morphogenetic Protein-2 and Vascular Endothelial Growth Factor in Tooth Extraction Socket

Aim To determine the effect of local simvastatin application on the mRNA expression level of transforming growth factor-β1 （TGF-β1）, bone morphogenetic protein-2 （BMP-2） and vascular endothelial growth factor （VEGF） in the tooth sockets of rat. Methodology Forty-eight male Wistar rats were randomly divided into experimental and control groups （n=24）. Polylactic acid/polyglycolic acid copolymer carriers, with or without simvastatin, were implanted into extraction sockets of right mandibular incisors. The expression of TGF-β1, BMP-2 and VEGF mRNA was determined by in situ hybridization in the tooth extraction socket at five days, one week, two weeks and four weeks after implantation. Results The fusiform stroma cells in the tooth extraction socket began to express TGF-β1, BMP-2 and VEGF mRNA in both experimental and control groups from one week after tooth extraction until the end of experiment. The expression of TGF-131 and BMP-2 mRNA in the experimental group was significantly up-regulated after one, two and four weeks, and expression of VEGF mRNA was significantly increased after one and two weeks compared with that in the control group. Conclusion The findings indicate that local administration of simvastatin can influence alveolar bone remodeling by regulating the expression of a school of growth factors which are crucial to osteogenesis in the tooth extraction socket.

Regulation of scleral fibroblast differentiation by bone morphogenetic protein-2

Bone morphogenesis proteins(BMPs) are multi-functional growth factors. They are expressed in retina,retinal pigment epithelium(RPE) and sclera and serve as a regulator in the growth and development of the eye. This article reviewed the chondrogenic potency of the sclera,biochemical and pathological changes of myopic scleral tissue and the differentiation of chondrogenesis by BMP-2. We proposed the hypothesis that BMP-2 can regulate differentiate of scleral fibroblasts and affect the development of myopia.

Heterotopic ossification after the use of recombinant human bone morphogenetic protein-7

AIM To present the incidence of heterotopic ossification after the use of recombinant human bone morphogenetic protein-7(rhB MP-7) for the treatment of nonunions.METHODS Bone morphogenetic proteins(BMPs) promote bone formation by auto-induction. Recombinant human BMP-7 in combination with bone grafts was used in 84 patients for the treatment of long bone nonunions. All patients were evaluated radiographicaly for the development of heterotopic ossification during the standard assessment for the nonunion healing. In all patients(80.9%) with radiographic signs of heterotopic ossification, a CT scan was performed. Nonunion site palpation and ROM evaluation of the adjacent jointswere also carried out. Factors related to the patient(age, gender), the nonunion(location, size, chronicity, number of previous procedures, infection, surrounding tissues condition) and the surgical procedure(graft and fixation type, amount of rhB MP-7) were correlated with the development of heterotopic ossification and statistical analysis with Pearsons χ~2 test was performed.RESULTS Eighty point nine percent of the nonunions treated with rh BMP-7, healed with no need for further procedures. Heterotopic bone formation occurred in 15 of 84 patients(17.8%) and it was apparent in the routine radiologi-cal evaluation of the nonunion site, in a mean time of 5.5 mo after the rh BMP-7 application(range 3-12). The heterotopic ossification was located at the femur in 8 cases, at the tibia in 6, and at the humerus in οne patient. In 4 patients a palpable mass was present and only in one patient, with a para-articular knee nonunion treated with rhB MP-7, the size of heterotopic ossification affected the knee range of motion. All the patients with heterotopic ossification were male. Statistical analysis proved that patient's gender was the only important factor for the development of heterotopic ossification(P = 0.007). CONCLUSION Heterotopic ossification after the use of rh BMP-7 in nonunions was common but it did not compromise the final clinical outcome in most cases, and affected only male patients.

Influence of bone morphogenetic protein type IA receptor conditional knockout in lens on expression of bone morphogenetic protein 4 in lens

AIM: To investigate the influence of bone morphogenetic protein type IA receptor [BMPR-IA(ALK3)] conditional knockout in lens on expression of bone morphogenetic protein 4(BMP4) in lens during the development of the vertebrate eye.METHODS: Cre-positive mice were mated with Crenegative mice to generate 50% Cre-positive(conditional knockout, CKO) 4 embryos, 8 eyes and 50% Cre-negative offspring(wild type, WT) 4 embryos, 8 eyes. The embryos were fixed in 4% paraformaldehyde, embedded in paraffin, and sectioned to a thickness of 4 μm.Removal of paraffin wax and dehydrating for sections,and then the procedure of in situ hybridization was processed, BMP4 MK1784-m(BOSTER) was used, and observed the expression of BMP4 in the lens in experimental group and control group. We selected SPSS11.0 software for statistical analysis, P【0.05 showed that the difference was statistically significant.· RESULTS: Four embryos of each genotype were examined, totally we had 8 embryos, 16 eyes. We got the uniform outcomes in all the embryos. We found ALK3 was required during lens growing, but was not essential for the formation of lens. We observed that the expression of BMP4 in the lens was significantly reduced in all 8 ALK3 CKO lens, BMP4 expression was normal in all the 8 WT lens, P 【0.01. This phenomenon became increasingly visible in accordance with embryo development. The most apparent alteration was present at stage E15.5.CONCLUSION: ALK3 is essential for lens growth. The influence of ALK3 on the expression of BMP4 is present during the development of mice lens.

Potential bone-inducing activity in vitro of recombinant human bone morphogenetic protein-7 from a CHO expression system

Objective: To express the recombinant human bone morphogenetic protein-7(rhBMP-7) in Chinese hamster ovary(CHO) cells, and to establish the in vitro biological activity assay of rhBMP-7.Methods: Human BMP-7 cDNA was subcloned into p114 mammalian expression vector and transfected to CHO cells by using the Lipofectamine 2000 transfection method. CHO cell supernatants were harvested and analyzed to identify the molecule mass of secreted rhBMP-7 and examine its biological activity in vitro to stimulate the synthesis of alkaline phophatase(ALP), a characteristic of osteoblast phenotypes. Results: rhBMP-7 was produced stably in CHO cells, as a processed mature disulfide-linked homodimer, with an apparent molecular mass of 36 000. Examination of the rhBMP-7 biological activity showed that rhBMP-7 specifically stimulated the production of ALP(4-fold increase at 100 ng of rhBMP-7/ml). Conclusion: The rhBMP-7 from CHO expression system has significant biological activity in induction of osteoblast phenotype, which demonstrates rhBMP-7 has the potential bone regeneration activity.

Bone morphogenetic protein-7 induced bone marrow stromal cells differentiate into neuron-like cells

Bone morphogenetic protein-7 is widely accepted as an inducer for bone marrow stem cells differentiating into osteoblasts and chondrocytes. Whether bone marrow stromal cells differentiate into neuron-like cells remains unclear. The current study examined the presence of positive cells for intermediate filament protein and microtubule associated protein-2 in the cytoplasm of bone marrow stromal cells induced by bone morphogenetic protein-7 under an inverted microscope, while no expression of glial fibrillary acidic protein was found. Reverse transcription PCR electrophoresis also revealed a positive target band for intermediate filament protein and microtubule-associated protein 2 mRNA. These results confirmed that bone morphogenetic protein-7 induces rat bone marrow stromal cells differentiating into neuron-like cells.

Implantation of xenogeneic bone combined with recombinant human bone morphogenetic protein-2 into bone defect—An scanning electron microscopic study

To determine the ability of a new type of composite xenogeneic bone grafting to repair bone defect. Methods: The new type of composite xenogeneic bone was obtained by combining the chemically treated cance1lous bone with recombinant human bone morphogenetic protein-2 (rhBMP-2). It was implanted on the bone defect of rabbit. Results: There was a large amount of new bone formation within the combined material and the amount was increasing as the time elapsed. In contrast, there was a lot of fibrous tissue with a little new bone formed on the area of the bone defect when the treated cancellous bone was implanted alone. Conclusion: The results imply that the rhBMP-2 plays a very important role in new bone formation and the composite xenogeneic bone appear to be an ideal material for repair of bone defect.

The Use of Bone Morphogenetic Protein-7 and Resveratrol in Collagen Type II of Articular Cartilage

This study aimed to investigate the effects of resveratrol and bone morphogenetic protein 7 on type II collagen from superficial and middle zone of porcine articular chondrocytes. Articular cartilage was isolated from dissected porcine knee joint n = 12. Isolated cells were plated as monolayers at a density of 1 × 105 cells/well in 12-well culture plates and incubated at 37℃ in a humid atmosphere of 5% carbon dioxide and 95% air. Cell cultures were treated for four days with various concentrations of bone morphogenetic protein-7 and resveratroL Cells were then collected and analysed for collagen type II expression by real time polymerase chain reaction and protein level quantification by enzyme-linked immunosorbent assay. Cartilage tissue sections were localised for collagen type II by immunohistochemistry. Moreover, resveratrol and bone morphogenetic protein-7 effects on cartilage matrix contents were analysed by histology. Resveratrol and bone morphogenetic protein-7 stimulates expression of collagen type II mRNA and protein level accumulation in the surface zone and middle zone at 50μM ＋ 300 ng/ml （RSV ＋ BMP-7）. Immunohistochemistry results confirmed the presence of collagen type II on articular cartilage. Histological tissue sections confirmed that chondrocytes were obtained from different zones of articular cartilage. The study suggests that a combination of bone morphogenetic protein-7 and resveratrol up-regulate the expression and synthesis of collagen type II.