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Bone Morphogenetic (bone + morphogenetic)
Kinds of Bone Morphogenetic Terms modified by Bone Morphogenetic Selected AbstractsBone morphogenetic protein-7 enhances dendritic growth and receptivity to innervation in cultured hippocampal neuronsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2000G. S. Withers Abstract Members of the bone morphogenetic protein (BMP) family of growth factors are present in the central nervous system during development and throughout life. They are known to play an important regulatory role in cell differentiation, but their function in postmitotic telencephalic neurons has not been investigated. To address this question, we examined cultured hippocampal neurons following treatment with bone morphogenetic protein-7 (BMP-7, also referred to as osteogenic protein-1). When added at the time of plating, BMP-7 markedly stimulated the rate of dendritic development. Within 1 day, the dendritic length of BMP-7-treated neurons was more than twice that of controls. By three days the dendritic arbors of BMP-7-treated neurons had attained a level of branching similar to that of 2-week-old neurons cultured under standard conditions. Several findings indicate that BMP-7 selectively enhances dendritic development. While dendritic length was significantly increased in BMP-7-treated neurons, the length of the axon was not. In addition, the mRNA encoding the dendritic protein MAP2 was significantly increased by BMP-7 treatment, but the mRNA for tubulin was not. Finally, BMP-7 did not enhance cell survival. Because dendritic maturation is a rate-limiting step in synapse formation in hippocampal cultures, we examined whether BMP-7 accelerated the rate at which neurons became receptive to innervation. Using two separate experimental paradigms, we found that the rate of synapse formation (assessed by counting synapsin I-positive presynaptic vesicle clusters) was increased significantly in neurons that had been exposed previously to BMP-7. Because BMP-7 and related BMPs are expressed in the hippocampus in situ, these factors may play a role in regulating dendritic branching and synapse formation in both development and plasticity. [source] Bone morphogenetic protein-6 induces the expression of inducible nitric oxide synthase in macrophagesIMMUNOLOGY, Issue 1pt2 2009Seok J. Kwon Summary Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-, (TGF-,) superfamily. In the present study, we investigated the effect of BMPs on the production of inducible nitric oxide synthase (iNOS) in the murine macrophage cell line, RAW 264.7, and in mouse peritoneal macrophages. Among the BMPs, only BMP-6 induced iNOS expression in a time-dependent and dose-dependent manner in both cell types. Induction of iNOS was inhibited by both cycloheximide and actinomycin D, indicating that the induction of iNOS expression by BMP-6 requires new protein synthesis. Mechanistic studies revealed that the BMP-6-induced iNOS expression requires both Smads and nuclear factor-kappa B (NF-,B) signalling pathways. Furthermore, induction of interleukin-1, (IL-1,) was necessary for iNOS induction by BMP-6. These observations suggest that BMP-6 stimulates macrophages to produce iNOS through IL-1, via Smad and NF-,B signalling pathways and that BMP-6 may be an important regulator of macrophages. [source] Soluble, insoluble and geometric signals sculpt the architecture of mineralized tissuesJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 2 2004U. Ripamonti Abstract Bone morphogenetic and osteogenic proteins (BMPs/OPs), members of the transforming growth factor-, (TGF-,) superfamily, are soluble mediators of tissue morphogenesis and induce de novo endochondral bone formation in heterotopic extraskeletal sites as a recapitulation of embryonic development. In the primate Papio ursinus, the induction of bone formation has been extended to the TGF-, isoforms per se. In the primate and in the primate only, the TGF-, isoforms are initiators of endochondral bone formation by induction and act in a species-, site- and tissue-specific mode with robust endochondral bone induction in heterotopic sites but with limited new bone formation in orthotopic bone defects. The limited inductive capacity orthotopically of TGF-, isoforms is associated with expression of the inhibitory Smads, Smad6 and Smad7. In primates, bone formation can also be induced using biomimetic crystalline hydroxyapatite matrices with a specific surface geometry and without the exogenous application of osteogenic proteins of the TGF-, superfamily, even when the biomimetic matrices are implanted heterotopically in the rectus abdominis muscle. The sequence of events that directs new bone formation upon the implantation of highly crystalline biomimetic matrices initiates with vascular invasion, mesenchymal cell migration, attachment and differentiation of osteoblast-like cells attached to the substratum, expression and synthesis of osteogenic proteins of the TGF-, superfamily resulting in the induction of bone as a secondary response. The above findings in the primate indicate enormous potential for the bioengineering industry. Of particular interest is that biomimetic matrices with intrinsic osteoinductivity would be an affordable option in the local context. [source] Distinct osteoblastic differentiation potential of murine fetal liver and bone marrow stroma-derived mesenchymal stem cellsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2008Olivia Fromigué Abstract Bone marrow-derived mesenchymal stem cells (MSC) are able to differentiate into osteoblasts under appropriate induction. Although MSC-derived osteoblasts are part of the hematopoietic niche, the nature of the stromal component in fetal liver remains elusive. Here, we determined the in vitro osteoblastic differentiation potential of murine clonal fetal liver-derived cells (AFT024, BFC012, 2012) in comparison with bone marrow-derived cell lines (BMC9, BMC10). Bone morphogenetic protein-2 (BMP2) increased alkaline phosphatase (ALP) activity, an early osteoblastic marker, in AFT024 and 2012 cells, whereas dexamethasone had little or no effect. BMP2, but not dexamethasone, increased ALP activity in BMC9 cells, and both inducers increased ALP activity in BMC10 cells. BMP2 increased ALP mRNA in AFT024, 2012 and BMC9 cells. By contrast, ALP was not detected in BMC10 and BFC012 cells. BMP2 and dexamethasone increased osteopontin and osteocalcin mRNA expression in 2012 cells. Furthermore, bone marrow-derived cells showed extensive matrix mineralization, whereas fetal liver-derived cell lines showed no or very limited matrix mineralization capacity. These results indicate that the osteoblast differentiation potential differs in bone marrow and fetal liver-derived cell lines, which may be due to a distinct developmental program or different microenvironment in the two hematopoietic sites. J. Cell. Biochem. 104: 620,628, 2008. © 2007 Wiley-Liss, Inc. [source] Sonic hedgehog is involved in osteoblast differentiation by cooperating with BMP-2JOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2002Takahito Yuasa The roles of Sonic hedgehog (Shh) and Bone morphogenetic protein-2 (Bmp-2) in osteoblast differentiation were investigated using in vitro cell systems. Recombinant amino-terminal portion of SHH (rSHH-N) dose dependently stimulated ALP activity in C3H10T1/2 and MC3T3-E1 cells. rSHH-N induced expression of Osteocalcin mRNA in C3H10T1/2 cells. A soluble form of the receptor for type IA BMP receptor antagonized rSHH-N-induced ALP activity in C3H10T1/2 and MC3T3-E1 cells, indicating that BMPs are involved in SHH-induced osteoblast differentiation. Simultaneous supplement with rSHH-N and BMP-2 synergistically induced ALP activity and expression of Osteocalcin mRNA in C3H10T1/2 cells. Pretreatment with rSHH-N for 6 h enhanced the response to BMP-2 by increasing ALP activity in C3H10T1/2 and MC3T3-E1 cells. Stimulatory effects of rSHH-N and additive effects with rSHH-N and BMP-2 on ALP activity were also observed in mouse primary osteoblastic cells. Transplantation of BMP-2 (1 ,g) into muscle of mice induced formation of ectopic bone, whereas transplantation of r-SHH-N (1,5 ,g) failed to generate it. These results indicate that Shh plays important roles in osteoblast differentiation by cooperating with BMP. © 2002 Wiley-Liss, Inc. [source] Bone morphogenetic protein-2 modulation of chondrogenic differentiation in vitro involves gap junction-mediated intercellular communicationJOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2002Wei Zhang Undifferentiated mesenchymal cells in the limb bud integrate a complex array of local and systemic signals during the process of cell condensation and chondrogenic differentiation. To address the relationship between bone morphogenetic protein (BMP) signaling and gap junction-mediated intercellular communication, we examined the effects of BMP-2 and a gap junction blocker 18 alpha glycyrrhetinic acid (18,-GCA) on mesenchymal cell condensation and chondrogenic differentiation in an in vitro chondrogenic model. We find that connexin43 protein expression significantly correlates with early mesenchymal cellular condensation and chondrogenesis in high-density limb bud cell culture. The level of connexin43 mRNA is maximally upregulated 48 h after treatment with recombinant human BMP-2 with corresponding changes in protein expression. Inhibition of gap junction-mediated intercellular communication with 2.5 ,M 18,-GCA decreases chondrogenic differentiation by 50% at 96 h without effects on housekeeping genes. Exposure to 18,-GCA for only the first 24,48 h after plating does not affect condensation or later chondrogenic differentiation suggesting that gap junction-mediated intercellular communication is not critical for the initial phase of condensation but is important for the onset of differentiation. 18,-GCA can also block the chondrogenic effects of BMP-2 without effects on cell number or connexin43 expression. These observations demonstrate 18,-GCA-sensitive regulation of intercellular communication in limb mesenchymal cells undergoing chondrogenic differentiation and suggest that BMP-2 induced chondrogenic differentiation may be mediated in part through the modulation of connexin43 expression and gap junction-mediated intercellular communication. J. Cell. Physiol. 193: 233,243, 2002. © 2002 Wiley-Liss, Inc. [source] Bone morphogenetic protein-mediated type II collagen expression in pilomatricoma and cutaneous mixed tumorJOURNAL OF CUTANEOUS PATHOLOGY, Issue 3 2005Hideki Mieno Background:, We have previously reported that type II collagen deposition in overlying dermo,epidermal junction (DEJ) of pilomatricoma is mediated by bone morphogenetic protein 2/4 (BMP 2/4) expressed by shadow cells (SCs) of pilomatricoma. Objective:, This time, we studied the expression of type II collagen and BMP in a large number of cases of pilomatricoma and extended our study to cutaneous mixed tumor (CMT). Results:, We found type II collagen deposition in the overlying DEJ (16 of 50 cases) and in the SCs (19/50) of pilomatricoma. The number of case of type II collagen deposition in DEJ (DEJ+) and in SCs (SC+) of pilomatricoma correlated to the chronological stage of pilomatricoma. We also found type II collagen deposition in overlying DEJ (two of 11) and in the stromal chondroid tissue (four of 11) of CMT. BMP 2 was expressed in most cases of pilomatricoma (37/50) and CMT (seven of 11). Conclusions:, The expression of type II collagen in pilomatricoma is dependent upon the chronological stage of pilomatricoma. Type II collagen expression in the overlying DEJ and chondroid matrix in CMT may be induced by BMP via the same mechanism as in pilomatricoma. [source] Effects of adenoviral-mediated coexpression of bone morphogenetic protein-7 and insulin-like growth factor-1 on human periodontal ligament cellsJOURNAL OF PERIODONTAL RESEARCH, Issue 4 2010L. Yang Yang L, Zhang Y, Dong R, Peng L, Liu X, Wang Y, Cheng X. Effects of adenoviral-mediated coexpression of bone morphogenetic protein-7 and insulin-like growth factor-1 on human periodontal ligament cells. J Periodont Res 2010; 45: 532,540. © 2010 John Wiley & Sons A/S Background and Objective:, Bone morphogenetic protein-7 (BMP-7) and insulin-like growth factor-1 (IGF-1) are important in periodontal reconstruction. However, their synergistic effect in periodontal regeneration by gene delivery has not been reported. In this study, gene delivery of these two growth factors to human periodontal ligament cells (hPDLCs) was examined for its effects on cell proliferation and differentiation. Material and Methods:, Recombinant adenoviruses containing both human BMP-7 and IGF-1 cDNA created by introducing the internal ribosome entry site (IRES) sequence were used to transfer the genes into hPDLCs. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and cell cycle analysis were used to observe their effects on cell proliferation, while alkaline phosphatase activity measurement, RT-PCR and in vivo tests were conducted to investigate their effects on cell differentiation. Results:, The proliferation of hPDLCs transduced by adenoviruses coexpressing BMP-7 and IGF-1 was suppressed while their differentiation ability was enhanced. There was a synergism of BMP-7 and IGF-1 in up-regulating alkaline phosphatase activity and mRNA levels of collagen type I and Runx2. Implantation in vivo with scaffolds illustrated that the transduced cells exhibited osteogenic differentiation and formed bone-like structures. Conclusion:, The combined delivery of BMP-7 and IGF-1 genes using an IRES-based strategy synergistically enhanced differentiation of hPDLCs. It is suggested that this could be a new potential method in gene therapy for periodontal reconstruction. [source] Bone morphogenetic protein-10 (BMP-10) inhibits aggressiveness of breast cancer cells and correlates with poor prognosis in breast cancerCANCER SCIENCE, Issue 10 2010Lin Ye Our recent study showed that a novel member of bone morphogenetic protein (BMP) family, BMP-10, was decreased in prostate cancer. In the present study, we investigated the implication of BMP-10 in breast cancer, particularly the relation of its expression with clinical aspects. The expression of BMP-10 was examined in a cohort of human breast cancer specimens (normal, n = 23; cancer, n = 97), using both quantitative real-time PCR and immunohistochemical staining. The full-length human BMP-10 was cloned into a mammalian expression plasmid vector and then transfected into breast cancer cells. The effect on growth, cell matrix adhesion, motility, and invasion of MDA-MB-231 cells by BMP-10 was then investigated using in vitro growth assays. Immunohistochemical staining and quantitative real-time PCR revealed a decreased expression of BMP-10 in breast cancer. Further analysis of BMP-10 transcript level against the clinical aspect demonstrated that the decreased BMP-10 expression correlated with disease progression, bone metastasis, and poor prognosis. The disease-free survival of the patients with a higher level of BMP-10 was 132.8 (95% CI, 122.0,143.5) months, significantly longer compared to 93.7 (95% CI, 60.3,127.2) months for patients with a lower level of BMP-10 expression (P = 0.043). The overexpression of BMP-10 has broad inhibitory effects on the in vitro growth, invasion, and motility of breast cancer cells. Taken together, BMP-10 can inhibit the cell growth of breast cancer cells, and decreased BMP-10 expression correlates to poor prognosis and disease progression, particularly the lymphatic and bone metastasis. Bone morphogenetic protein-10 (BMP-10) may function as a tumor suppressor in breast cancer. (Cancer Sci 2010) [source] A Murine Osteosarcoma Cell Line with a Potential to Develop Ossification upon TransplantationCANCER SCIENCE, Issue 6 2001Tomomi Kusumi An Osteosarcoma cell line has been established from a soft tissue tumor that occurred spontaneously in a BALB/c mouse. This cell line showed ossification when transplanted into syngeneic mice. To examine the mechanism of bone formation, the expression of mRNAs for osteoblastic and chon-droblastic markers and factors associated with ossification has been investigated. In culture, the cells exhibited a spindle shape in the growth phase, but had a polygonal shape in the stationary phase. Reverse transcription-polymerase chain reaction analysis showed that the cells expressed mRNAs for pro-,(I) chain of type I collagen, alkaline phosphatase, osteopontin, osteocalcin, and core binding factor al, suggesting differentiation into the stage of osteoblasts during the stationary phase. After transplantation, histological examination revealed small foci of pale blue material and basophilic networks that were scattered in the tumor tissues at one week. The former stained positive with alcian blue, suggesting a chondroid matrix. Pro-,(II) chain of type II collagen mRNA was expressed at one week. A large part of tumors at two and three weeks consisted of basophilic networks, which stained positive via von Kossa's method, indicating a calcified woven bone. In situ hybridization analysis showed strong expression of osteopontin and osteocalcin mRNAs in tumor cells surrounding the bone matrix. Bone morphogenetic protein-6 and -7 mRNAs were detected in transplanted tumors, but not in cultured cells. These results suggest that the cell line has the properties of an osteoblastic lineage when cultured in vitro and has an ossifying ability through endochondral bone formation processes when transplanted in vivo. [source] Busulfan-induced central polydactyly, syndactyly and cleft hand or foot: A common mechanism of disruption leads to divergent phenotypesDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 6 2007Takuji Naruse The prevalence of clinical phenotypes that exhibit combinations of central polydactyly, syndactyly, or cleft hand or foot is higher than would be expected for random independent mutations. We have previously demonstrated that maternal ingestion of a chemotherapeutic agent, busulfan, at embryonic day 11 (E11) induces these defects in various combinations in rat embryo limbs. In an effort to determine the mechanism by which busulfan disrupts digital development, we examined cell death by Nile Blue staining and TdT-mediated dUTP nick end labeling (TUNEL) assays; we also carried out whole mount in situ hybridization for fibroblast growth factor-8 (Fgf8), bone morphogenetic protein-4 (Bmp4), and sonic hedgehog (Shh) to examine developmental pathways linked to these defects. In busulfan-treated embryos, diffuse cell death was evident in both ectoderm and mesoderm, peaking at E13. The increased cell death leads to regression of Fgf8 in the apical ectodermal ridge (AER) and Bmp4 and Shh in the underlying mesoderm. The subsequent pattern of interdigital apoptosis and cartilage condensation was variably disrupted. These results suggest that busulfan manifests its teratogenic effects by inducing cell death of both ectoderm and mesoderm, with an associated reduction in tissue and a disruption in the generation of patterning molecules during critical periods of digit specification. [source] Shh/BMP-4 signaling pathway is essential for intestinal epithelial development during Xenopus larval-to-adult remodelingDEVELOPMENTAL DYNAMICS, Issue 12 2006Atsuko Ishizuya-Oka Abstract During amphibian larval-to-adult intestinal remodeling, progenitor cells of the adult epithelium actively proliferate and differentiate under the control of thyroid hormone (TH) to form the intestinal absorptive epithelium, which is analogous to the mammalian counterpart. We previously found that TH,up-regulated expression of bone morphogenetic protein-4 (BMP-4) spatiotemporally correlates with adult epithelial development in the Xenopus laevis intestine. Here, we aimed to clarify the role of BMP-4 in intestinal remodeling. Our reverse transcriptase-polymerase chain reaction and in situ hybridization analyses indicated that mRNA of BMPR-IA, a type I receptor of BMP-4, is expressed in both the developing connective tissue and progenitor cells of the adult epithelium. More importantly, using organ culture and immunohistochemical procedures, we have shown that BMP-4 not only represses cell proliferation of the connective tissue but promotes differentiation of the intestinal absorptive epithelium. In addition, we found that the connective tissue-specific expression of BMP-4 mRNA is up-regulated by sonic hedgehog (Shh), whose epithelium-specific expression is directly induced by TH. These results strongly suggest that the Shh/BMP-4 signaling pathway plays key roles in the amphibian intestinal remodeling through epithelial,connective tissue interactions. Developmental Dynamics 235:3240,3249, 2006. © 2006 Wiley-Liss, Inc. [source] Vascular endothelial growth factor receptor signaling is required for cardiac valve formation in zebrafishDEVELOPMENTAL DYNAMICS, Issue 1 2006You Mie Lee Abstract Vascular endothelial growth factor-receptors (VEGF-Rs) are pivotal regulators of vascular development, but a specific role for these receptors in the formation of heart valves has not been identified. We took advantage of small molecule inhibitors of VEGF-R signaling and showed that blocking VEGF-R signaling with receptor selective tyrosine kinase inhibitors, PTK 787 and AAC 787, from 17,21 hr post-fertilization (hpf) in zebrafish embryos resulted in a functional and structural defect in cardiac valve development. Regurgitation of blood between the two chambers of the heart, as well as a loss of cell-restricted expression of the valve differentiation markers notch 1b and bone morphogenetic protein-4 (bmp - 4), was readily apparent in treated embryos. In addition, microangiography revealed a loss of a definitive atrioventricular constriction in treated embryos. Taken together, these data demonstrate a novel function for VEGF-Rs in the endocardial endothelium of the developing cardiac valve. Developmental Dynamics 235:29,37, 2006. © 2005 Wiley-Liss, Inc. [source] Bone morphogenetic protein-7 enhances dendritic growth and receptivity to innervation in cultured hippocampal neuronsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2000G. S. Withers Abstract Members of the bone morphogenetic protein (BMP) family of growth factors are present in the central nervous system during development and throughout life. They are known to play an important regulatory role in cell differentiation, but their function in postmitotic telencephalic neurons has not been investigated. To address this question, we examined cultured hippocampal neurons following treatment with bone morphogenetic protein-7 (BMP-7, also referred to as osteogenic protein-1). When added at the time of plating, BMP-7 markedly stimulated the rate of dendritic development. Within 1 day, the dendritic length of BMP-7-treated neurons was more than twice that of controls. By three days the dendritic arbors of BMP-7-treated neurons had attained a level of branching similar to that of 2-week-old neurons cultured under standard conditions. Several findings indicate that BMP-7 selectively enhances dendritic development. While dendritic length was significantly increased in BMP-7-treated neurons, the length of the axon was not. In addition, the mRNA encoding the dendritic protein MAP2 was significantly increased by BMP-7 treatment, but the mRNA for tubulin was not. Finally, BMP-7 did not enhance cell survival. Because dendritic maturation is a rate-limiting step in synapse formation in hippocampal cultures, we examined whether BMP-7 accelerated the rate at which neurons became receptive to innervation. Using two separate experimental paradigms, we found that the rate of synapse formation (assessed by counting synapsin I-positive presynaptic vesicle clusters) was increased significantly in neurons that had been exposed previously to BMP-7. Because BMP-7 and related BMPs are expressed in the hippocampus in situ, these factors may play a role in regulating dendritic branching and synapse formation in both development and plasticity. [source] Noggin blocks invasive growth of murine B16-F1 melanoma cells in the optic cup of the chick embryo,,INTERNATIONAL JOURNAL OF CANCER, Issue 3 2008Christian Busch Abstract Melanoma cells originate from the neural crest and are characterized by high migratory potential and invasive growth. After transplantation into the neural tube of the chick embryo, melanoma cells spontaneously emigrate along the neural crest pathways without tumor formation or malignant growth. This emigration depends on the constitutive over-expression of bone morphogenetic protein-2 (BMP-2) and can be ablated by the BMP-antagonist noggin. When transplanted into the embryonic optic cup, melanoma cells invade the host tissue and form malignant tumors. Here, we asked if the invasive growth of melanoma cells in the optic cup could be influenced by BMP-2 or noggin. Mouse B16-F1 cells were grown as aggregates, treated with BMP-2 or noggin during aggregation and transplanted into the optic cup of 3-day chick embryos. After 3 days of subsequent incubation, embryos were evaluated for melanoma cell invasiveness. Immunohistochemical examination revealed that untreated and BMP-2-treated melanoma cells had grown malignantly into the host tissue. However, noggin pretreatment of the aggregates had blocked melanoma cell invasiveness and tumor formation. We conclude that invasive growth of melanoma cells in vivo is BMP-dependent and can be ablated by noggin, thus rendering noggin a promising agent for the treatment of BMP-over-expressing melanoma. © 2007 Wiley-Liss, Inc. [source] Lyophilization to improve drug delivery for chitosan-calcium phosphate bone scaffold construct: A preliminary investigationJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2009Benjamin T. Reves Abstract Lyophilization was evaluated in chitosan-calcium phosphate microspheres and scaffolds to improve drug delivery of growth factors and antibiotics for orthopedic applications. The dual delivery of an antibiotic and a growth factor from a composite scaffold would be beneficial for treatment of complex fracture sites, such as comminuted fractures and segmental bone defects. The aim of this investigation was to increase the loading capacity of the composite by taking advantage of the increased porosity, due to lyophilization, and to produce an extended elution profile using a secondary chitosan-bead coating. The physiochemical properties of the composite were investigated, and loading and elution studies were performed with alkaline phosphatase (ALP), bone morphogenetic protein-2 (BMP-2), and amikacin. Lyophilization was found to increase the surface area of scaffolds by over 400% and the porosity of scaffolds by 50%. Using ALP as a model protein, the loading capacity was increased by lyophilization from 4.3 ± 2.5 to 24.6 ± 3.6 ,g ALP/mg microspheres, and the elution profile was extended by a supplemental chitosan coating. The loading capacity of BMP-2 for composite microspheres was increased from 74.4 ± 3.7 to 102.1 ± 8.0 ,g BMP-2/g microspheres with lyophilization compared with nonlyophilized microspheres. The elution profiles of BMP-2 and the antibiotic amikacin were not extended with the supplemental coating. Additional investigations are planned to improve these elution characteristics for growth factors and antibiotics. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009 [source] Hydroxyapatite fiber material with BMP-2 gene induces ectopic bone formationJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2009Mitsumasa Oda Abstract Collagen containing bone morphogenetic protein-2 (BMP-2) expression vector, which is called "gene-activated matrix," promotes bone regeneration when transplanted to the bone defect. We speculated that hydroxyapatite fiber (HF) would be an ideal matrix for "gene-activated matrix" especially for bone regeneration, because it is oseteoconductive and has high affinity to DNA. The purpose of this study is to clarify whether HF containing BMP-2 expression vector induces ectopic bone formation. We prepared HF containing 0, 10, 50, and 100 ,g BMP-2 expression vector. Wistar male rats (8 weeks) were used and each rat received two HF implants in the left and right dorsal muscle. The rats were sacrificed 4, 8, and 12 weeks after the operation, and implants were analyzed radiographically by softex, dual-energy X-ray absorptiometry, and they were histologically examined. At 4 weeks, HF containing 50 or 100 ,g BMP-2 expression vector showed high bone mineral contents and large radiopaque volume compared to the other implants. At 8 and 12 weeks, HF containing 50 ,g BMP-2 expression vector exerted the highest values in the radiographic analyses. Bonelike tissue was histologically observed in HF containing 50 and 100 ,g BMP-2 expression vector groups but not detected in the other implants. The present results suggest that HF is potential as a matrix for "gene-activated matrix" for bone tissue engineering. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009 [source] Repair of segmental defects in rabbit humeri with titanium fiber mesh cylinders containing recombinant human bone morphogenetic protein-2 (rhBMP-2) and a synthetic polymerJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2002Narumichi Murakami Abstract To develop a new technology that enhances the regeneration potential of bone and the repair of large intercalated defects in long bone, recombinant human bone morphogenetic protein-2 (BMP-2; 20 ,g or 40 ,g) was mixed in a polymer gel (poly-lactic acid-polyethyleneglycol block copolymer; PLA-PEG; 200 mg) and incorporated into titanium fiber-mesh cylinders. Three 5-mm cylinders were placed end-to-end to fill a 15-mm defect created in the humeri of adult rabbits and were stabilized by an intramedullary rod. In controls, the titanium fiber-mesh cylinders were combined with PLA-PEG in the absence of BMP. Six weeks after implantation, new bone had formed on the surface of the implant and had bridged the defect. All of the defects (5/5) treated by cylinders containing 120 ,g (40 ,g × 3) of BMP were repaired completely. New bone formation was also found inside the pores of the cylinders. The defect was not repaired in the control animals. These results demonstrate that these new composite implants fabricated by combining rhBMP, synthetic degradable polymers and compatible biomaterials enhance the regeneration potential of bone. Thus, it is possible that large skeletal defects can be repaired using this prosthesis in lieu of autogenous bone graft. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 169,174, 2002 [source] Shock Wave Application Enhances Pertussis Toxin Protein-Sensitive Bone Formation of Segmental Femoral Defect in Rats,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 12 2003Yeung-Jen Chen Abstract Extracorporeal shock waves (ESWs) elicit a dose-dependent effect on the healing of segmental femoral defects in rats. After ESW treatment, the segmental defect underwent progressive mesenchymal aggregation, endochondral ossification, and hard callus formation. Along with the intensive bone formation, there was a persistent increase in TGF-,1 and BMP-2 expression. Pretreatment with pertussis toxin reduced ESW-promoted callus formation and gap healing, which presumably suggests that Gi proteins mediate osteogenic signaling. Introduction: Extracorporeal shock waves (ESWs) have previously been used to promote bone repair. In our previous report, we found that ESWs promoted osteogenic differentiation of mesenchymal cells through membrane perturbation and activation of Ras protein. In this report, we show that ESWs elicit a dose-dependent effect on the healing of segmental defects and that Gi proteins play an important role in mediating ESW stimulation. Materials and Methods: Rats with segmental femoral defects were subjected to ESW treatment at different energy flux densities (EFD) and impulses. Bone mass (mineral density and calcium content), osteogenic activities (bone alkaline phosphatase activity and osteocalcin content), and immunohistochemistry were assessed. Results: An optimal ESW energy (500 impulses at 0.16 mJ/mm2 EFD) stimulated complete bone healing without complications. ESW-augmented healing was characterized by significant increases (p < 0.01) in callus size, bone mineral density, and bone tissue formation. With exposure to ESW, alkaline phosphatase activity and osteocalcin production in calluses were found to be significantly enhanced (p < 0.05). After ESW treatment, the histological changes we noted included progressive mesenchymal aggregation, endochondral ossification, and hard callus formation. Intensive bone formation was associated with a persistent increase in transforming growth factor-beta 1 (TGF-,1) and bone morphogenetic protein-2 (BMP-2) expression, suggesting both growth factors were active in ESW-promoted bone formation. We also found that pertussis toxin, an inhibitor of membrane-bound Gi proteins, significantly reduced (p < 0.01) ESW promotion of callus formation and fracture healing. Conclusion: ESW treatments enhanced bone formation and the healing of segmental femoral defects in rats. It also seems likely that TGF-,1 and BMP-2 are important osteogenic factors for ESW promotion of fracture healing, presumably through Gi protein-mediated osteogenic signaling. [source] Characterization of the upstream mouse Cbfa1/Runx2 promoter,JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 4 2001Z. S. Xiao Abstract Cbfa1 (or Runx2/AML-3/PEPB2,) is a transcriptional activator of osteoblastic differentiation. To investigate the regulation of Cbfa1 expression, we isolated and characterized a portion of the 5,-flanking region of the Cbfa1 gene containing its "bone-related" or P1 promoter and exon 1. We identified additional coding sequence in exon 1 and splice donor sites that potentially give rise to a novel Cbfa1 isoform containing an 18 amino acid insert. In addition, primer extension mapping identified in the Cbfa1 promoter a minor mRNA start site located ,0.8 kb 5, upstream of the ATG encoding the MASN/p57 isoform and ,0.4 kb upstream of the previously reported start site. A luciferase reporter construct containing 1.4 kb of the mouse Cbfa1 promoter was analyzed in Ros 17/2.8 and MC3T3-E1 osteoblast cell lines that express high levels of Cbfa1 transcripts. The activity of this construct was also examined in non-osteoblastic Cos-7 and NIH3T3 cells that do not express Cbfa1 and mesenchymal-derived cell lines, including CH3T101/2, C2C12, and L929 cells, that express low levels of mature Cbfa1 transcripts. The 1.4 kb 5, flanking sequence of the Cbfa1 gene directed high levels of transcriptional activity in Ros 17/2.8 and MC3T3-E1 osteoblasts compared to non-osteoblasts Cos-7 cells, but this construct also exhibited high levels of expression in C310T1/2, L929, and C2C12 cells as well as NIH3T3 cells. In addition, Cbfa1 mRNA expression, but not the activity of the Cbfa1 promoter, was upregulated in a dose-dependent manner in pluripotent mesenchymal C2C12 by bone morphogenetic protein-2 (BMP-2). These data indicate that Cbfa1 is expressed in osteogenic as well as non-osteogenic cells and that the regulation of Cbfa1 expression is complex, possibly involving both transcriptional and post-transcriptional mechanisms. Additional studies are needed to further characterize important regulatory elements and to identify additional regions of the promoter and/or post-transcriptional events responsible for the cell-type restricted regulation of Cbfa1 expression. J. Cell. Biochem. 82: 647,659, 2001. © 2001 Wiley-Liss, Inc. [source] Oversulfated chondroitin sulfate-E binds to BMP-4 and enhances osteoblast differentiationJOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2008Tatsuya Miyazaki Small leucine-rich proteoglycans, such as biglycan, and their side chain sulfated glycosaminoglycans (GAGs), have been suggested to be involved in bone formation and mineralization processes. The present study was designed to investigate whether chondroitin sulfate (CS), one of the GAG, and its oversulfated structures coupled with bone morphogenetic protein-4 (BMP-4) alter the differentiation and subsequent mineralization of MC3T3-E1 osteoblastic cells. CS-E, one of the oversulfated CS structure, enhanced cell growth, alkaline phosphatase (ALP) activity, collagen deposition, and mineralization whereas heparin enhanced only ALP activity and mineralization. As well as CS-E, CS-H, and CPS also enhanced the mineralization of the cells. CS-E enhanced the mineralization of the cells by interacting with protein in the conditioned medium. CS-E induced mineralization was significantly inhibited by an antibody against BMP-4. The addition of exogenous BMP-4 further increased the capacity of CS-E to enhance mineralization. Fluorescence correlation spectroscopy method using fluoresceinamine-labeled GAG revealed that the oversulfated GAGs have a high affinity for BMP-4. The disaccharide analysis of the cells indicated that MC3T3-E1 cells are capable of producing oversulfated structures of CS by themselves. The lack of CS from the cells after chondroitinase treatment resulted in the inhibition of mineralization. These results in the present study indicate that oversulfated CS, which possesses 4,6-disulfates in N -acetyl-galactosamine, binds to BMP-4 and promotes osteoblast differentiation and subsequent mineralization. J. Cell. Physiol. 217: 769,777, 2008. © 2008 Wiley-Liss, Inc. [source] Sox9, a key transcription factor of bone morphogenetic protein-2-induced chondrogenesis, is activated through BMP pathway and a CCAAT box in the proximal promoter,JOURNAL OF CELLULAR PHYSIOLOGY, Issue 1 2008Qiuhui Pan Mouse embryonic fibroblasts (MEFs) can be differentiated into fully functional chondrocytes in response to bone morphogenetic protein-2 (BMP-2). The expression of Sox9, a critical transcription factor for the multiple steps of chondrogenesis, has been reported to be upregulated during this process. But the molecular mechanisms by which BMP-2 promotes chondrogenesis still remain largely unknown. The aim of the present study was therefore to investigate the underlying mechanism. In the MEFs, BMP-2 efficiently induced Sox9 expression along with chondrogenic differentiation in a time- and dose-dependent manner. SB203580, a specific inhibitor for p38 pathway, blocked BMP-2-induced chondrogenic differentiation as well as Sox9 expression and its transactivation of downstream genes. Forced expression of Smad6, a natural antagonist for BMP/Smad pathway, only inhibited Sox9 protein function without rendering any effects on its mRNA expression. A CCAAT box was identified in Sox9 promoter as the cis -elements responsible for BMP-2 stimulation. This study provides insight into the mechanisms underlying BMP-2-regulated Sox9 expression and activity in MEFs, and suggests differential roles of BMP-2/p38 and BMP-2/Smad pathways in modulating the function of Sox9 during chondrogenesis. J. Cell. Physiol. 217: 228,241, 2008. © 2008 Wiley-Liss, Inc. [source] Alveolar ridge augmentation using implants coated with recombinant human bone morphogenetic protein-7 (rhBMP-7/rhOP-1): histological observationsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 6 2010Cristiano Susin Susin C, Qahash M, Polimeni G, Lu PH, Prasad HS, Rohrer MD, Hall J, Wikesjö UME. Alveolar ridge augmentation using implants coated with recombinant human bone morphogenetic protein-7 (rhBMP-7/rhOP-1): histological observations. J Clin Periodontol 2010; 37: 574,581. doi: 10.1111/j.1600-051X.2010.01554.x. Abstract Background: Pre-clinical studies have shown that recombinant human bone morphogenetic protein-2 (rhBMP-2) coated onto purpose-designed titanium porous-oxide surface implants induces clinically relevant bone formation and osseointegration. The objective of this study was to examine the potential of rhBMP-7, also known as recombinant human osteogenic protein-1 (rhOP-1), coated onto titanium porous-oxide surface implants to support vertical alveolar ridge augmentation and implant osseointegration. Materials and Methods: Bilateral, critical-size, 5 mm, supraalveolar peri-implant defects were created in six young adult Hound Labrador mongrel dogs. The animals received implants coated with rhBMP-7 at 1.5 or 3.0 mg/ml randomized to contra-lateral jaw quadrants. The mucoperiosteal flaps were advanced, adapted, and sutured to submerge the implants for primary intention healing. The animals received fluorescent bone markers at 3, 4, 7, and 8 weeks post-surgery when they were euthanized for histological evaluation. Results: Without striking differences between treatments, the implant sites exhibited a swelling that gradually regressed to become hard to palpation disguising the implant contours. The histological evaluation showed robust bone formation; the newly formed bone assuming characteristics of the contiguous resident bone, bone formation (height and area) averaging 4.1±1.0 versus 3.6±1.7 mm and 3.6±1.9 versus 3.1±1.8 mm2; and bone density 56%versus 50% for implants coated with rhBMP-7 at 1.5 and 3.0 mg/ml, respectively. Both treatments exhibited clinically relevant osseointegration, the corresponding bone,implant contact values averaging 51% and 47%. Notable peri-implant resident bone remodelling was observed for implants coated with rhBMP-7 at 3.0 mg/ml. Conclusions: rhBMP-7 coated onto titanium porous-oxide surface implants induces clinically relevant local bone formation including osseointegration and vertical augmentation of the alveolar ridge, the higher concentration/dose associated with some local side effects. [source] Evaluation of implants coated with rhBMP-2 using two different coating strategies: a critical-size supraalveolar peri-implant defect study in dogsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 6 2010Jaebum Lee Lee J, Decker JF, Polimeni G, Cortella CA, Rohrer MD, Wozney JM, Hall J, Susin C, Wikesjö UME. Evaluation of implants coated with rhBMP-2 using two different coating strategies: a critical-size supraalveolar peri-implant defect study in dogs. J Clin Periodontol 2010; 37: 582,590. doi: 10.1111/j.1600-051X.2010.01557.x. Abstract Background: Implants coated with recombinant human bone morphogenetic protein-2 (rhBMP-2) induce relevant bone formation but also resident bone remodelling. Objectives: To compare the effect of implants fully or partially coated with rhBMP-2 on new bone formation and resident bone remodelling. Materials and Methods: Twelve, male, adult, Hound Labrador mongrel dogs were used. Critical-size, supraalveolar, peri-implant defects received titanium porous oxide surface implants coated in their most coronal aspect with rhBMP-2 (coronal-load/six animals) or by immersion of the entire implant in an rhBMP-2 solution (soak-load/six animals) for a total of 30 ,g rhBMP-2/implant. All implants were air-dried. The animals were euthanized at 8 weeks for histometric evaluation. Results: Clinical healing was uneventful. Supraalveolar bone formation was not significantly affected by the rhBMP-2 application protocol. New bone height and area averaged (± SE) 3.4 ± 0.2 versus 3.5 ± 0.4 mm and 2.6 ± 0.4 versus 2.5 ± 0.7 mm2 for coronal-load and soak-load implants, respectively (p>0.05). The corresponding bone density and bone,implant contact (BIC) recordings averaged 38.0 ± 3.8%versus 34.4 ± 5.6% and 25.0 ± 3.8%versus 31.2 ± 3.3% (p>0.05). In contrast, resident bone remodelling was significantly influenced by the rhBMP-2 application protocol. Bone density outside the implants threads averaged 74.7 ± 3.8% and 50.8 ± 4.1% for coronal-load and soak-load implants, respectively (p<0.05); bone density within the thread area averaged 51.8 ± 1.2% and 37.8 ± 2.9%, and BIC 70.1 ± 6.7% and 43.3 ± 3.9% (p<0.05). Conclusion: Local application of rhBMP-2 appears to be a viable technology to support local bone formation and osseointegration. Coronal-load implants obviate resident bone remodelling without compromising new bone formation. [source] Ex vivo bone morphogenetic protein-2 gene delivery using gingival fibroblasts promotes bone regeneration in ratsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 3 2010Joong-Ho Shin Shin J-H, Kim K-H, Kim S-H, Koo K-T, Kim T-I, Seol Y-J, Ku Y, Rhyu I-C, Chung C-P, Lee Y-M. Ex vivo bone morphogenetic protein-2 gene delivery using gingival fibroblasts promotes bone regeneration in rats. J Clin Periodontol 2009; 37: 305,311. doi: 10.1111/j.1600-051X.2009.01522.x. Abstract Aim: The aim of the present study was to investigate bone regeneration following ex vivo bone morphogenetic protein-2 (BMP-2) gene delivery using human gingival fibroblasts (HGFs) in rat calvarial defects. Materials and Methods: An 8 mm craniotomy defect was created in Sprague,Dawley rats. The animals were divided into four groups: (1) non-grafted group, the defect was left empty; (2) collagen matrix group, the defect was filled with collagen matrix only; (3) HGF group, the defect was filled with non-transduced HGFs on collagen matrix; (4) BMP-2/HGF group, the defect was filled with BMP-2 gene-transduced HGFs on collagen matrix. Animals were sacrificed at 2 and 4 weeks after surgery, and micro-computed tomographic and histologic observations were performed. Results: The BMP-2/HGF group showed promoted osseous healing of calvarial defects, as compared with the other groups. At both 2 and 4 weeks, regenerated bone area was significantly greater in the BMP-2/HGF group than the other three groups. Quite a few number of transplanted HGFs were observed within the regenerated bone tissues. Conclusions: The results of this study suggest that ex vivo BMP-2 gene delivery induces prominent bone regeneration in vivo and HGFs may be useful as target cells for ex vivo gene therapy. [source] Bone formation at recombinant human bone morphogenetic protein-2-coated titanium implants in the posterior maxilla (Type IV bone) in non-human primatesJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2008Ulf M. E. Wikesjö Abstract Background: Studies using ectopic rodent and orthotopic canine models (Type II bone) have shown that titanium porous oxide (TPO) surface implants adsorbed with recombinant human bone morphogenetic protein-2 (rhBMP-2) induce local bone formation including osseointegration. The objective of this study was to evaluate local bone formation and osseointegration at such implants placed into Type IV bone. Material and Methods: rhBMP-2-coated implants were installed into the edentulated posterior maxilla in eight young adult Cynomolgus monkeys: four animals each received three TPO implants adsorbed with rhBMP-2 (2.0 mg/ml) and four animals each received three TPO implants adsorbed with rhBMP-2 (0.2 mg/ml). Contra-lateral jaw quadrants received three TPO implants without rhBMP-2 (control). Treatments were alternated between left and right jaw quadrants. Mucosal flaps were advanced and sutured to submerge the implants. The animals received fluorescent bone markers at weeks 2, 3, 4, and at week 16 when they were euthanized for histologic analysis. Results: Clinical healing was uneventful. Extensive local bone formation was observed in animals receiving implants adsorbed with rhBMP-2 (2.0 mg/ml). The newly formed bone exhibited a specific pinpoint bone,implant contact pattern regardless of rhBMP-2 concentration resulting in significant osseointegration; rhBMP-2 (2.0 mg/ml): 43% and rhBMP-2 (0.2 mg/ml): 37%. Control implants exhibited a thin layer of bone covering a relatively larger portion of the implant threads. Thus, TPO control implants bone exhibited significantly greater bone,implant contact (,75%; p<0.05). There were no statistically significant differences between rhBMP-2-coated and control implants relative to any other parameter including peri-implant and intra-thread bone density. Conclusion: rhBMP-2-coated TPO implants enhanced/accelerated local bone formation in Type IV bone in a dose-dependent fashion in non-human primates resulting in significant osseointegration. rhBMP-2-induced de novo bone formation did not reach the level of osseointegration observed in native resident bone within the 16-week interval. [source] Alveolar ridge augmentation using implants coated with recombinant human bone morphogenetic protein-2: histologic observationsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2008Ulf M. E. Wikesjö Abstract Background: Studies using ectopic rodent, orthotopic canine, and non-human primate models show that bone morphogenetic proteins (BMPs) coated onto titanium surfaces induce local bone formation. The objective of this study was to examine the ability of recombinant human BMP-2 (rhBMP-2) coated onto a titanium porous oxide implant surface to stimulate local bone formation including osseointegration and vertical augmentation of the alveolar ridge. Material and Methods: Bilateral, critical-size, 5 mm, supra-alveolar, peri-implant defects were created in 12 young adult Hound Labrador mongrel dogs. Six animals received implants coated with rhBMP-2 at 0.75 or 1.5 mg/ml, and six animals received implants coated with rhBMP-2 at 3.0 mg/ml or uncoated control. Treatments were randomized between jaw quadrants. The mucoperiosteal flaps were advanced, adapted and sutured to submerge the implants for primary intention healing. The animals received fluorescent bone markers at weeks 3, 4, 7 and 8 post-surgery when they were euthanized for histologic evaluation. Results: Jaw quadrants receiving implants coated with rhBMP-2 exhibited gradually regressing swelling that became hard to palpate disguising the contours of the implants. The histologic evaluation showed robust bone formation reaching or exceeding the implant platform. The newly formed bone exhibited characteristics of the adjoining resident Type II bone including cortex formation for sites receiving implants coated with rhBMP-2 at 0.75 or 1.5 mg/ml. Sites receiving implants coated with rhBMP-2 at 3.0 mg/ml exhibited more immature trabecular bone formation, seroma formation and peri-implant bone remodelling resulting in undesirable implant displacement. Control implants exhibited minimal, if any, bone formation. Thus, implants coated with rhBMP-2 at 0.75, 1.5 and 3.0 mg/ml exhibited significant bone formation (height and area) compared with the sham-surgery control averaging (±SD) 4.4±0.4, 4.2±0.7 and 4.2±1.2 versus 0.8±0.3 mm; and 5.0±2.2, 5.6±2.2 and 7.4±3.5 versus 0.7±0.3 mm2, respectively (p<0.01). All the treatment groups exhibited clinically relevant osseointegration. Conclusions: rhBMP-2 coated onto titanium porous oxide implant surfaces induced clinically relevant local bone formation including vertical augmentation of the alveolar ridge and osseointegration. Higher concentrations/doses were associated with untoward effects. [source] Alveolar ridge augmentation using implants coated with recombinant human bone morphogenetic protein-7 (rhBMP-7/rhOP-1): radiographic observationsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 10 2008Knut N. Leknes Abstract Aim: The objective of this study was to radiographically evaluate the potential of a purpose-designed titanium porous-oxide implant surface coated with recombinant human bone morphogenetic protein-7 (rhBMP-7), also known as recombinant human osteogenic protein-1 (rhOP-1), to stimulate alveolar ridge augmentation. Material and Methods: Six young-adult Hound Labrador mongrel dogs were used. Three 10 mm titanium oral implants per jaw quadrant were placed 5 mm into the alveolar ridge in the posterior mandible following surgical extraction of the pre-molar teeth and reduction of the alveolar ridge leaving 5 mm of the implants in a supra-alveolar position. The implants had been coated with rhBMP-7 at 1.5 or 3.0 mg/ml and were randomized to contralateral jaw quadrants using a split-mouth design. The mucoperiosteal flaps were advanced, adapted, and sutured to submerge the implants. Radiographic registrations were made immediately post-surgery (baseline), and at weeks 4 and 8 (end of study). Results: rhBMP-7-coated implants exhibited robust radiographic bone formation. At 8 weeks, bone formation averaged 4.4 and 4.2 mm for implants coated with rhBMP-7 at 1.5 and 3.0 mg/ml, respectively. There were no significant differences between the rhBMP-7 concentrations at any observation interval. A majority of the implant sites showed voids within the newly formed bone at week 4 that generally resolved by week 8. The newly formed bone assumed characteristics of the resident bone. Conclusions: The titanium porous-oxide implant surface serves as an effective carrier for rhBMP-7 showing a clinically significant potential to stimulate local bone formation. [source] Bone formation at rhBMP-2-coated titanium implants in the rat ectopic modelJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 5 2007Jan Hall Abstract Background: The objective of this study was to evaluate local bone formation at titanium porous oxide (TPO) implant surfaces adsorbed with recombinant human bone morphogenetic protein-2 (rhBMP-2). Methods: In vitro studies were used to estimate the kinetics of I125 -labeled rhBMP-2 released from TPO surfaces with narrow (N) or open (O) pores. Machined/turned titanium (MT) surfaces served as control. The rat ectopic model was used to assess local bone formation. Briefly, TPO-N, TPO-O, and MT disc implants adsorbed with 5, 10, or 20 ,g rhBMP-2, respectively, were implanted subcutaneously into the ventral thoracic region in 5-week-old male Long Evans rats. The animals were euthanized at day 14 postsurgery when implants with surrounding tissues were removed, radiographed, and gross observations recorded. The specimens were processed for histologic evaluation using conventional cut-and-grind techniques. TPO implants without rhBMP-2 included in a preliminary evaluation revealed no evidence of bone formation, tissue encapsulation, or vascularity, thus such controls were not further used. Results: TPO and MT implant surfaces adsorbed with 5 ,g rhBMP-2 retained 2.3,5.4% rhBMP-2 following immersion and rinse in buffer, and 1.1,2.2% rhBMP-2 following repeated immersions and rinses over 27 days. TPO implants retained the most rhBMP-2 and MT implants retained the least. Explants revealed increased hard tissue formation, tissue encapsulation, and vascularity at TPO compared with MT implants. Radiographic observations were consistent with the explant observations. The histologic analysis showed greater amounts of bone formation, osteoblastic cells, osteoid, marrow, tissue encapsulation, vascularity, and bone voids for implants adsorbed with 10 and 20 ,g rhBMP-2, and for TPO implants at the 5- ,g rhBMP-2 dose. The histometric analysis revealed significantly greater bone formation at TPO-O than at MT implants at the 5- ,g rhBMP-2 dose. All surfaces showed significant bone formation at the 10- and 20- ,g dose. Conclusions: rhBMP-2 adsorbed onto TPO implant surfaces executes an osteoinductive effect including bone contacting the implant surface. This effect is surface- and dose-dependent; the TPO-O surface yielding the most bone at the low discriminating rhBMP-2 dose. [source] Transforming growth factor- , stimulates Interleukin-11 production by human periodontal ligament and gingival fibroblastsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 3 2006R. Yashiro Abstract Background: Transforming growth factor (TGF)- , is a potent multifunctional polypeptide, abundant in the bone matrix. Interleukin (IL)-11 is a pleiotropic cytokine with effects on multiple cell types. The present study was performed to evaluate the regulatory effects of TGF- , on IL-11 production by human periodontal ligament cells (PDL) and human gingival fibroblasts (HGF). Material and Methods: The expression of TGF- , receptor in PDL and HGF were observed using flow cytometry. PDL and HGF were stimulated with TGF- , with or without protein kinase C (PKC) inhibitors and activator. IL-11, bone morphogenetic protein-2 (BMP-2) and TGF- , mRNA expression was quantified by real-time polymerase chain reaction (PCR). IL-11 production was measured using enzyme-linked immunosorbent assay. Results: PDL and HGF expressed both TGF- , receptor I and TGF- , receptor II on the cell surfaces. IL-11 mRNA expression and IL-11 production were augmented by TGF- , in both PDL and HGF, with higher values in PDL. PKC inhibitors partially suppressed TGF- , -induced IL-11 production in PDL and HGF, whereas activator enhanced it. TGF- , mRNA and BMP-2 mRNA expression were up-regulated by TGF- , in PDL. Conclusion: These results suggest that PDL produce IL-11 in response to TGF- ,. [source] | |||||||||||||||||||||||||||||||