The Experts below are selected from a list of 441 Experts worldwide ranked by ideXlab platform
A. Hari Reddi - One of the best experts on this subject based on the ideXlab platform.
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Growth and morphogenetic factors in bone induction: role of Osteogenin and related bone morphogenetic proteins in craniofacial and periodontal bone repair.
Critical Reviews in Oral Biology & Medicine, 2016Co-Authors: Ugo Ripamonti, A. Hari ReddiAbstract:Bone has considerable potential for repair as illustrated by the phenomenon of fracture healing. Repair and regeneration of bone recapitulate the sequential stages of development. It is well known that demineralized bone matrix has the potential to induce new bone formation locally at a heterotopic site of implantation. The sequential development of bone is reminiscent of endochondral bone differentiation during bone development. The collagenous matrix-induced bone formation is a prototype model for matrix-cell interactions in vivo. The developmental cascade includes migration of progenitor cells by chemotaxis, attachment of cells through fibronectin, proliferation of mesenchymal cells, and differentiation of bone. The bone inductive protein, Osteogenin, was isolated by heparin affinity chromatography. Osteogenin initiates new bone formation and is promoted by other growth factors. Recently, the genes for Osteogenin and related bone morphogenetic proteins were cloned and expressed. Recombinant Osteogenin ...
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Initiation and promotion of bone differentiation by bone morphogenetic proteins
Journal of Bone and Mineral Research, 2009Co-Authors: A. Hari Reddi, N. S. CunninghamAbstract:The presence of growth and differentiation factors in bone has been demonstrated by subcutaneous implantation of demineralized bone matrix that initiates new cartilage and bone morphogenesis. The genes for bone morphogenetic proteins (BMPs) have been cloned and expressed. Recombinant BMPs induce endochondral bone formation in vivo. The multistep sequential developmental cascade consists of chemotaxis, mitosis, and differentiation of cartilage and bone. The pleiotropic response has been well characterized. BMPs stimulate osteogenic and chondrogenic phenotypes. Natural bovine Osteogenin (BMP-3) and recombinant BMP-4 are equipotent in chemotaxis, limb bud chondrogenesis, cartilage maintenance, and in vivo bone induction
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Osteogenin-enhanced bone-specific differentiation in hydroxyapatite orbital implants.
Ophthalmic Plastic and Reconstructive Surgery, 1997Co-Authors: Bryan S. Sires, John B. Holds, Marilyn C. Kincaid, A. Hari ReddiAbstract:Hydroxyapatite orbital implants undergo early ingrowth of fibrovascular tissue after enucleation. This animal study determined whether control and Osteogenin-impregnated hydroxyapatite orbital implants vary in their osteogenic response at 6 and 52 weeks. Rabbits underwent enucleation with implantation of control or Osteogenin-impregnated hydroxyapatite spheres. Light microscopy determined fibrovascular ingrowth, and histomorphometry quantitated the amount of bone produced. Osteogenin implants vascularized at a faster rate and contained bony foci by 6 weeks that became confluent at I year. Spontaneous osteogenesis was not seen in control animals at 6 weeks. After I year they contained bone, although less than in the Osteogenin implants. Mixed cell inflammation was observed at the hydroxyapatite. -tissue interface in both groups. No inflammation was noted at the interface of hydroxyapatite and bone. These are the first controlled observations that bone-specific differentiation occurs in the pores of spherical hydroxyapatite implants within the soft tissues of the socket. This vascularized process can be enhanced with Osteogenin to occur earlier and more uniformly in the implants at one year.
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Initiation and promotion of bone differentiation by bone morphogenetic proteins
Journal of Bone and Mineral Research, 1993Co-Authors: A. Hari Reddi, Noreen S. CunninghamAbstract:The presence of growth and differentiation factors in bone has been demonstrated by subcutaneous implantation of demineralized bone matrix that initiates new cartilage and bone morphogenesis. The genes for bone morphogenetic proteins (BMPs) have been cloned and expressed. Recombinant BMPs induce endochondral bone formation in vivo. The multistep sequential developmental cascade consists of chemotaxis, mitosis, and differentiation of cartilage and bone. The pleiotropic response has been well characterized. BMPs stimulate osteogenic and chondrogenic phenotypes. Natural bovine Osteogenin (BMP-3) and recombinant BMP-4 are equipotent in chemotaxis, limb bud chondrogenesis, cartilage maintenance, and in vivo bone induction. There are multiple isoforms of BMPs, raising the biologic relevance of the redundancy. The mode of action and second messengers are not clear. BMPs appear to have cognate receptors as demonstrated by iodinated BMP-2B (BMP-4). Other novel members of the BMP family include osteogenic protein 1 (BMP-7) and osteogenic protein 2 (BMP-8). Bone morphogenetic proteins are members of the transforming growth factor-beta superfamily and include three distinct subfamilies: BMP-2, BMP-3, and BMP-7. Native BMP-3 and recombinant BMP-4 bind type IV collagen of the basement membrane. This novel connection may be the long elusive mechanistic explanation for the requirement of angiogenesis and vascular invasion for bone morphogenesis. BMPs may have a role in fracture repair, periodontal regeneration, and alveolar ridge augmentation.
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Osteogenin, a bone morphogenetic protein, adsorbed on porous hydroxyapatite substrata, induces rapid bone differentiation in calvarial defects of adult primates.
Plastic and Reconstructive Surgery, 1992Co-Authors: Ugo Ripamonti, Barbara Van Den Heever, A. Hari ReddiAbstract:Osteogenin, a bone morphogenetic protein, in conjunction with insoluble collagenous bone matrix initiates local endochondral bone differentiation by induction in vivo. This study, by exploiting the affinity of native Osteogenin for hydroxyapatite, was designed to construct a delivery system for the expression of the biologic activity of Osteogenin in nonhealing calvarial defects of adult primates. After exposure of the calvaria, 64 cranial defects, 25 mm in diameter, were prepared in 16 adult male baboons (Papio ursinus). Defects were implanted with disks of porous nonresorbable and resorbable hydroxyapatite substrata obtained after hydrothermal conversion of calcium carbonate exoskeletons of corals. In each animal, one disk of each hydroxyapatite preparation was treated with Osteogenin isolated and purified from baboon bone matrix after sequential chromatography on heparin-Sepharose, hydroxyapatite, and Sephacryl S-200 gel filtration columns. The remaining two defects were implanted with one disk of each hydroxyapatite preparation without Osteogenin as control. Histomorphometry on decalcified sections prepared on days 30 and 90 showed superior osteogenesis in Osteogenin-treated nonresorbable hydroxyapatite specimens as compared with controls. On day 90, substantial bone formation also had occurred in control nonresorbable hydroxyapatite specimens. On day 90, but not on day 30, significantly greater amounts of bone had formed in Osteogenin-treated resorbable specimens as compared with resorbable controls. Overall, resorbable substrata performed poorly when compared with nonresorbable substrata, perhaps due to a premature dissolution of the implants. These results provide evidence that the biologic activity of Osteogenin can be restored and delivered by a substratum other than the organic collagenous matrix, inducing rapid bone differentiation in calvarial defects of adult nonhuman primates. The adsorption strategy of Osteogenin on porous inorganic nonimmunogenic substrata may help to design appropriate osteogenic delivery systems for craniofacial and orthopedic applications in humans.
A. H. Reddi - One of the best experts on this subject based on the ideXlab platform.
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Tricalcium phosphate and Osteogenin: a bioactive onlay bone graft substitute.
Plastic and Reconstructive Surgery, 1995Co-Authors: Arnold S. Breitbart, N. S. Cunningham, A. H. Reddi, David A. Staffenberg, Charles H. Thorne, Paul M. Glat, John L. Ricci, German C. SteinerAbstract:The disadvantages of autogenous bone grafts has prompted a search for a dependable onlay bone graft substitute. A combination of tricalcium phosphate, a resorbable ceramic, and Osteogenin, an osteoinductive protein, was evaluated as an onlay bone graft substitute in a rabbit calvarial model. Twenty-eight tricalcium phosphate implants (15 mm diameter X 5 mm ; pore size, 100-200 μm) were divided into experimental and control groups and placed on the frontal bone of 14 adult New Zealand White rabbits. In the experimental animals, 185 μg of Osteogenin was added to each implant. In the control animals, the implants were placed untreated. Implants were harvested at intervals of 1, 3, and 6 months, and evaluated using hematoxylin and eosin histology, microradiography, and histomorphometric scanning electron microscope backscatter image analysis. At 1 month there was minimal bone ingrowth and little tricalcium phosphate resorption in both the Osteogenin-treated and control implants. At 3 months, both the Osteogenin-treated and control implants showed a modest increase in bone ingrowth (8.85 percent versus 5.87 percent) and decrease in tricalcium phosphate (32.86 percent versus 37.08 percent). At 6 months, however, the Osteogenin-treated implants showed a statistically significant increase in bone ingrowth (22.33 percent versus 6.96 percent ; p = 0.000) and decrease in tricalcium phosphate (27.25 percent versus 37.80 percent ; p = 0.004) compared with the control implants. The bone within the control implants was mostly woven at 6 months, whereas the Osteogenin-treated implants contained predominantly mature lamellar bone with well-differentiated marrow. All implants maintained their original volume at each time interval studied. The tricalcium phosphate/Osteogenin composite, having the advantage of maintaining its volume and being replaced by new bone as the tricalcium phosphate resorbs, may be applicable clinically as an onlay bone graft substitute.
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the effect of Osteogenin a bone morphogenetic protein on the formation of bone in orthotopic segmental defects in rats
Journal of Bone and Joint Surgery American Volume, 1994Co-Authors: Sharon Stevenson, N Cunningham, Jeffrey M Toth, Dwight T Davy, A. H. ReddiAbstract:We studied the effects of partially purified, natural Osteogenin, a bone morphogenetic protein, on the formation of bone in rats. An osteoperiosteal segmental defect, eight millimeters wide, in the middle of the femoral diaphysis was created bilaterally in thirty-six adult male Fischer rats and stabilized with a polyacetyl plate and threaded Kirschner wires. One defect was filled with a cylinder of 60 per cent hydroxyapatite and 40 per cent tricalcium phosphate ceramic (pore diameter, 250 to 400 micrometers) containing 100 micrograms of partially purified bovine Osteogenin, and the contralateral defect was filled with a hydroxyapatite-tricalcium ceramic cylinder without Osteogenin. Eighteen animals (six animals each at one, two, and four months after the operation) were studied histologically and histomorphometrically. The implants from eighteen additional animals (six animals each at one, two, and four months after the operation) were subjected to biomechanical testing. Histomorphometry revealed that the total area of bone, the area of bone outside of the implant, and the amount of bone within the pores of the implant were all significantly (p <= 0.05) greater in the femora that had an implant with Osteogenin than in those that had an implant without Osteogenin at most time-periods. The presence of Osteogenin had no significant effect on the biomechanical parameters measured in this study. Bone loss due to trauma, excision of a tumor, or loosening and subsidence of a joint prosthesis is a major clinical problem. Although bone has a remarkable potential for regeneration, predictable augmentation of the natural repair process would be useful in certain orthopaedic situations. Particularly attractive would be the augmentation of bone repair without the need for a cancellous autogenous bone graft, which necessitates a second operative procedure. In this study, an Osteogenin-containing ceramic cylinder significantly (p <= 0.005) enhanced the formation of bone in and around a large segmental defect. This enhanced repair occurred without the addition of cancellous autogenous bone graft or marrow cells and suggests that Osteogenin may be useful in the repair of skeletal defects and that this ceramic configuration may be a useful carrier of Osteogenin.
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Osteoclast recruiting activity in bone matrix
Bone and Mineral, 1994Co-Authors: T.a. Hentunen, N. S. Cunningham, A. H. Reddi, O. Vuolteenaho, H.k. VäänänenAbstract:Abstract An activity that recruits osteoclasts has been identified and partially characterized from bone matrix. Bone-derived osteoclast recruiting activity (BORA) was co-purified with Osteogenin, a bone inductive protein. Osteogenin was extracted from bovine bone with 6 M urea and purified by chromatography on hydroxyapatite, heparin-Sepharose and Sephacryl S-200 gel filtration. The biologically active osteoclast formation-stimulating material was further purified by C 18 reverse phase HPLC. BORA is obviously distinct from Osteogenin and transforming growth factor β (TGF- β ), since further purified Osteogenin and pure TGF- β did not stimulate the formation of osteoclast-like cells. BORA (0.1–10 μ g/ml) stimulated the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells (MNC) in a dose-dependent manner. These multinucleated cells resorbed bone when cultured on bovine bone slices. The effect of BORA is primarily directed to differentiate osteoclast precursors, since it did not stimulate osteoclast function in in vitro resorption assay where disaggregated rat osteoclasts were cultured on bovine bone slices. However, after 24 h preincubation with 50 nM PTH in the mouse calvaria assay, BORA at 10 μ g/ml significantly stimulated bone resorption.
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Reconstruction of the Bone-Bone Marrow Organ by Osteogenin, a Bone Morphogenetic Protein, and Demineralized Bone Matrix in Calvarial Defects of Adult Primates
Plastic and Reconstructive Surgery, 1993Co-Authors: Ugo Ripamonti, N. S. Cunningham, Laura Yeates, A. H. ReddiAbstract:Information concerning the efficacy of Osteogenin, a bone morphogenetic protein, and demineralized bone matrix in orthotopic sites in nonhuman primates is a prerequisite for potential clinical application in humans. After exposure of the calvaria, 84 cranial defects, 25 mm in diameter, were prepared in 26 adult male baboons (Papio ursinus). Defects were implanted with insoluble collagenous bone matrix (ICBM, the inactive collagenous residue after dissociative extraction of bone matrix with 4 M guanidine hydrochloride) reconstituted with Osteogenin fractions isolated from baboon bone matrix by chromatography on heparin-Sepharose and hydroxyapatite-Ultrogel (Og Hep-HA) or Osteogenin further purified using Sephacryl S-200 gel filtration chromatography (Og S-200). Baboon Osteogenin with the highest biologic activity in a rodent bioassay, as determined by alkaline phosphatase activity, calcium content, and histologic analysis, was used for orthotopic implantation in baboons. Additional defects were implanted with baboon demineralized bone matrix (DBM) or ICBM without Osteogenin as control. Defects also were grafted with corticocancellous bone harvested from the iliac crest or left ungrafted to monitor the spontaneous regeneration potential of the adult baboon calvaria. Undecalcified bone sections at 7 microns were prepared from the harvested specimens 30 and 90 days after surgery. Histomorphometry demonstrated that Og S-200 induced copious amounts of bone and osteoid as early as day 30 (P < 0.01 versus ICBM, autogenous grafts and untreated defects). At day 90, in implants of Og S-200, Og Hep-HA, and DBM, bone and marrow formation was extensive, culminating in complete regeneration of the craniotomies. In implants of DBM, bone formed with an intervening phase of cartilage development. This provides the phenotypic evidence of endochondral bone differentiation by induction in defects of membranous calvarial bone in adult primates. These results establish the potential therapeutic application of Osteogenin and demineralized bone matrix for the architectural reconstruction of the bone-bone marrow organ in humans.
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Initiation of bone regeneration in adult baboons by Osteogenin, a bone morphogenetic protein.
Matrix, 1992Co-Authors: Ugo Ripamonti, L. Yeates, N. S. Cunningham, A. H. ReddiAbstract:Osteogenin, and related bone morphogenetic proteins, induce endochondral bone differentiation through a cascade of events which include formation of cartilage, hypertrophy and calcification of the cartilage, vascular invasion, differentiation of osteoblasts, and formation of bone. These events have been studied in a postnatal model of bone development in rodents. Information concerning the morphogenetic potential of Osteogenin in primates is a prerequisite for potential clinical application in man. The efficacy of allogeneic Osteogenin in primates was investigated in both extraskeletal and skeletal sites in 19-Chacma baboons (Papio ursinus). Osteogenin was isolated from demineralized baboon bone matrix and purified by chromatography on heparin-Sepharose, hydroxyapatite, and Sephacryl S-200. Protein fractions with a molecular mass range of 26-42 kDa induced cartilage and bone differentiation in the subcutaneous space of rats. Final purification to homogeneity was obtained by electroendosmotic elution from a preparative sodium dodecyl sulphate (SDS) polyacrylamide gel, resulting in a single band on a SDS-polyacrylamide gel with an apparent molecular mass of 30-34 kDa, with biological activity in rats. The osteoinductive potential of Osteogenin in primates was tested first in intramuscular sites in baboons and found to be active. The bone regeneration potential was investigated in nonhealing calvarial defects surgically prepared in adult male baboons. Baboon Osteogenin induced complete regeneration of the cranial wound. These findings in adult primates establish a primary role for Osteogenin in initiation and promotion of osteogenesis, and imply a potential therapeutic application based on cell biology of extracellular matrix-cell interactions.
Ugo Ripamonti - One of the best experts on this subject based on the ideXlab platform.
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Growth and morphogenetic factors in bone induction: role of Osteogenin and related bone morphogenetic proteins in craniofacial and periodontal bone repair.
Critical Reviews in Oral Biology & Medicine, 2016Co-Authors: Ugo Ripamonti, A. Hari ReddiAbstract:Bone has considerable potential for repair as illustrated by the phenomenon of fracture healing. Repair and regeneration of bone recapitulate the sequential stages of development. It is well known that demineralized bone matrix has the potential to induce new bone formation locally at a heterotopic site of implantation. The sequential development of bone is reminiscent of endochondral bone differentiation during bone development. The collagenous matrix-induced bone formation is a prototype model for matrix-cell interactions in vivo. The developmental cascade includes migration of progenitor cells by chemotaxis, attachment of cells through fibronectin, proliferation of mesenchymal cells, and differentiation of bone. The bone inductive protein, Osteogenin, was isolated by heparin affinity chromatography. Osteogenin initiates new bone formation and is promoted by other growth factors. Recently, the genes for Osteogenin and related bone morphogenetic proteins were cloned and expressed. Recombinant Osteogenin ...
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Reconstruction of the Bone-Bone Marrow Organ by Osteogenin, a Bone Morphogenetic Protein, and Demineralized Bone Matrix in Calvarial Defects of Adult Primates
Plastic and Reconstructive Surgery, 1993Co-Authors: Ugo Ripamonti, N. S. Cunningham, Laura Yeates, A. H. ReddiAbstract:Information concerning the efficacy of Osteogenin, a bone morphogenetic protein, and demineralized bone matrix in orthotopic sites in nonhuman primates is a prerequisite for potential clinical application in humans. After exposure of the calvaria, 84 cranial defects, 25 mm in diameter, were prepared in 26 adult male baboons (Papio ursinus). Defects were implanted with insoluble collagenous bone matrix (ICBM, the inactive collagenous residue after dissociative extraction of bone matrix with 4 M guanidine hydrochloride) reconstituted with Osteogenin fractions isolated from baboon bone matrix by chromatography on heparin-Sepharose and hydroxyapatite-Ultrogel (Og Hep-HA) or Osteogenin further purified using Sephacryl S-200 gel filtration chromatography (Og S-200). Baboon Osteogenin with the highest biologic activity in a rodent bioassay, as determined by alkaline phosphatase activity, calcium content, and histologic analysis, was used for orthotopic implantation in baboons. Additional defects were implanted with baboon demineralized bone matrix (DBM) or ICBM without Osteogenin as control. Defects also were grafted with corticocancellous bone harvested from the iliac crest or left ungrafted to monitor the spontaneous regeneration potential of the adult baboon calvaria. Undecalcified bone sections at 7 microns were prepared from the harvested specimens 30 and 90 days after surgery. Histomorphometry demonstrated that Og S-200 induced copious amounts of bone and osteoid as early as day 30 (P < 0.01 versus ICBM, autogenous grafts and untreated defects). At day 90, in implants of Og S-200, Og Hep-HA, and DBM, bone and marrow formation was extensive, culminating in complete regeneration of the craniotomies. In implants of DBM, bone formed with an intervening phase of cartilage development. This provides the phenotypic evidence of endochondral bone differentiation by induction in defects of membranous calvarial bone in adult primates. These results establish the potential therapeutic application of Osteogenin and demineralized bone matrix for the architectural reconstruction of the bone-bone marrow organ in humans.
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Initiation of bone regeneration in adult baboons by Osteogenin, a bone morphogenetic protein.
Matrix, 1992Co-Authors: Ugo Ripamonti, L. Yeates, N. S. Cunningham, A. H. ReddiAbstract:Osteogenin, and related bone morphogenetic proteins, induce endochondral bone differentiation through a cascade of events which include formation of cartilage, hypertrophy and calcification of the cartilage, vascular invasion, differentiation of osteoblasts, and formation of bone. These events have been studied in a postnatal model of bone development in rodents. Information concerning the morphogenetic potential of Osteogenin in primates is a prerequisite for potential clinical application in man. The efficacy of allogeneic Osteogenin in primates was investigated in both extraskeletal and skeletal sites in 19-Chacma baboons (Papio ursinus). Osteogenin was isolated from demineralized baboon bone matrix and purified by chromatography on heparin-Sepharose, hydroxyapatite, and Sephacryl S-200. Protein fractions with a molecular mass range of 26-42 kDa induced cartilage and bone differentiation in the subcutaneous space of rats. Final purification to homogeneity was obtained by electroendosmotic elution from a preparative sodium dodecyl sulphate (SDS) polyacrylamide gel, resulting in a single band on a SDS-polyacrylamide gel with an apparent molecular mass of 30-34 kDa, with biological activity in rats. The osteoinductive potential of Osteogenin in primates was tested first in intramuscular sites in baboons and found to be active. The bone regeneration potential was investigated in nonhealing calvarial defects surgically prepared in adult male baboons. Baboon Osteogenin induced complete regeneration of the cranial wound. These findings in adult primates establish a primary role for Osteogenin in initiation and promotion of osteogenesis, and imply a potential therapeutic application based on cell biology of extracellular matrix-cell interactions.
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Osteogenin, a bone morphogenetic protein, adsorbed on porous hydroxyapatite substrata, induces rapid bone differentiation in calvarial defects of adult primates.
Plastic and Reconstructive Surgery, 1992Co-Authors: Ugo Ripamonti, Barbara Van Den Heever, A. Hari ReddiAbstract:Osteogenin, a bone morphogenetic protein, in conjunction with insoluble collagenous bone matrix initiates local endochondral bone differentiation by induction in vivo. This study, by exploiting the affinity of native Osteogenin for hydroxyapatite, was designed to construct a delivery system for the expression of the biologic activity of Osteogenin in nonhealing calvarial defects of adult primates. After exposure of the calvaria, 64 cranial defects, 25 mm in diameter, were prepared in 16 adult male baboons (Papio ursinus). Defects were implanted with disks of porous nonresorbable and resorbable hydroxyapatite substrata obtained after hydrothermal conversion of calcium carbonate exoskeletons of corals. In each animal, one disk of each hydroxyapatite preparation was treated with Osteogenin isolated and purified from baboon bone matrix after sequential chromatography on heparin-Sepharose, hydroxyapatite, and Sephacryl S-200 gel filtration columns. The remaining two defects were implanted with one disk of each hydroxyapatite preparation without Osteogenin as control. Histomorphometry on decalcified sections prepared on days 30 and 90 showed superior osteogenesis in Osteogenin-treated nonresorbable hydroxyapatite specimens as compared with controls. On day 90, substantial bone formation also had occurred in control nonresorbable hydroxyapatite specimens. On day 90, but not on day 30, significantly greater amounts of bone had formed in Osteogenin-treated resorbable specimens as compared with resorbable controls. Overall, resorbable substrata performed poorly when compared with nonresorbable substrata, perhaps due to a premature dissolution of the implants. These results provide evidence that the biologic activity of Osteogenin can be restored and delivered by a substratum other than the organic collagenous matrix, inducing rapid bone differentiation in calvarial defects of adult nonhuman primates. The adsorption strategy of Osteogenin on porous inorganic nonimmunogenic substrata may help to design appropriate osteogenic delivery systems for craniofacial and orthopedic applications in humans.
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The critical role of geometry of porous hydroxyapatite delivery system in induction of bone by Osteogenin, a bone morphogenetic protein.
Matrix, 1992Co-Authors: Ugo Ripamonti, A. Hari ReddiAbstract:Abstract The collagenous extracellular matrix of bone obtained after dissociative extraction with 4 M guanidine-HCI is an optimal substratum for bone induction by Osteogenin, a bone morphogenetic protein. As a proteinaceous substratum, this matrix and other collagen-based materials may be immunogenic. Thus, the search and discovery of a non-immunogenic substratum is a necessary prerequisite for the therapeutic application of the principle of bone induction to skeletal repair. Bovine Osteogenin, purified greater than 50,000-fold and with an apparent molecular mass of 28 - 42 kilodaltons, was delivered into nonresorbable porous hydroxyapatite in granular and disc configuration. A total of 328 preparations were bioassayed for osteogenic activity by subcutaneous implantation into 164 Long-Evans rats. Specimens were harvested at day 7,11 and 21 after implantation and subjected to alkaline phosphatase activity determination and histologic analysis. Osteogenin combined with discs of porous hydroxyapatite induced in vivo differentiation of the osteogenic phenotype in mesenchymal cells invading the three-dimensional porous space of the inorganic substratum. The geometry of the substratum had a profound influence on bone induction, since the expression of the osteogenic phenotype was solely confined in porous hydroxyapatite with disc configuration. Osteogenin did not induce bone differentiation when combined with granules of porous hydroxyapatite with identical pore dimensions. The finding that the biological activity of Osteogenin can be restored and delivered by a substratum with defined geometry other than the insoluble collagenous matrix may form the basis of the potential therapeutic application of bone morphogenetic proteins.
Vishwas M. Paralkar - One of the best experts on this subject based on the ideXlab platform.
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Advances in Osteogenin and related bone morphogenetic proteins in bone induction and repair.
Acta Orthopaedica Belgica, 1992Co-Authors: Frank P Luyten, Vishwas M. Paralkar, Slobodan Vukicevic, Ugo Ripamonti, N. S. Cunningham, A. Hari ReddiAbstract:Bone matrix is a repository of growth and differentiation factors as demonstrated by the induction of local cartilage and bone formation in rats. The bone inductive activity, termed Osteogenin, can be dissociatively extracted, and it was isolated by heparin affinity, hydroxyapatite and molecular sieve chromatography. Osteogenin has been purified to homogeneity from bovine bone matrix and the sequences of several tryptic peptides have been determined. The sequences were similar to portions of the amino acid sequence deduced from the cDNA clone of bone morphogenetic protein-3 (BMP-3). The carboxyl-terminal quarter of Osteogenin has sequence identity to the corresponding regions of two related proteins BMP-2A and BMP-2B. The bone inductive proteins are members of the TGF-beta superfamily, by virtue of the location of the highly conserved cysteines in their carboxyl-terminal region. Osteogenin and related BMPs initiate cartilage and bone formation in vivo. The study of the mechanism of action of these proteins will add considerable new information on the molecular signals controlling endochondral bone formation. In vitro data indicate that Osteogenin stimulates the expression of the osteogenic and chondrogenic phenotypes. Our results demonstrate their profound influence on proteoglycan synthesis and degradation in bovine cartilage explant cultures. High affinity specific binding sites have been identified in both MC3T3 cells and articular chondrocytes. In vivo experiments demonstrate the efficacy of primate Osteogenin in restoring large calvarial defects in adult baboons, establishing a primary role for Osteogenin in therapeutic initiation and promotion of osteogenesis.
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interaction of Osteogenin a heparin binding bone morphogenetic protein with type iv collagen
Journal of Biological Chemistry, 1990Co-Authors: A K Nandedkar, Hynda K Kleinman, Vishwas M. Paralkar, Ricahard H. Pointer, A. Hari ReddiAbstract:Abstract Osteogenin, an extracellular matrix component of bone, is a heparin binding differentiation factor that initiates endochondral bone formation in rats when implanted subcutaneously with an insoluble collagenous matrix. We have examined the interaction of Osteogenin with various extracellular matrix components including basement membranes. Osteogenin, purified from bovine bone, binds avidly to type IV collagen and to a lesser extent to both type I and IX collagens. Osteogenin binds equally well to both native and denatured type IV collagen. Both alpha 1 and alpha 2 chains of type IV collagen are recognized by Osteogenin. Osteogenin binds to a collagen IV affinity column, and is eluted by 6.0 M urea with 1 M NaCl, pH 7.4, and the eluate contained the osteogenic activity as demonstrated in vivo. Binding of Osteogenin to collagen IV is not influenced by either laminin or fibronectin. These results imply that Osteogenin binding to extracellular matrix components including collagens I and IV and heparin may have physiological relevance, and such interactions may modulate its local action.
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Autoradiographic localization of Osteogenin binding sites in cartilage and bone during rat embryonic development.
Developmental Biology, 1990Co-Authors: Slobodan Vukicevic, Vishwas M. Paralkar, N. S. Cunningham, J S Gutkind, A. H. ReddiAbstract:Abstract Osteogenin, a novel bone differentiation factor isolated from bone, has been recently purified and the amino acid sequence determined. Osteogenin in conjunction with a collagenous bone matrix substratum induces cartilage and bone formation in vivo . In order to understand the developmental role of Osteogenin during cartilage and bone morphogenesis we examined the binding and distribution of iodinated Osteogenin in developing rat embryos. Whole embryo tissue sections were made from 11, 12, 13, 15, 18, and 20 day fetuses. The specific binding of Osteogenin at different stages of rat embryonic development was determined by autoradiography. Maximal binding was observed in mesodermal tissues such as cartilage, bone, perichondrium, and periosteum. During Days 11–15, peak binding was localized to perichondrium during limb and vertebral morphogenesis. By Day 18 periosteum exhibited the highest concentration of autoradiographic grains. Osteogenin was also localized in developing membranous bones of the calvarium and other craniofacial bones. Considerably less binding was observed, in decreasing order, in muscle, liver, spleen, skin, brain, heart, kidney, and intestine. The observed maximal binding during skeletal morphogenesis implies a developmental role for Osteogenin.
N. S. Cunningham - One of the best experts on this subject based on the ideXlab platform.
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Initiation and promotion of bone differentiation by bone morphogenetic proteins
Journal of Bone and Mineral Research, 2009Co-Authors: A. Hari Reddi, N. S. CunninghamAbstract:The presence of growth and differentiation factors in bone has been demonstrated by subcutaneous implantation of demineralized bone matrix that initiates new cartilage and bone morphogenesis. The genes for bone morphogenetic proteins (BMPs) have been cloned and expressed. Recombinant BMPs induce endochondral bone formation in vivo. The multistep sequential developmental cascade consists of chemotaxis, mitosis, and differentiation of cartilage and bone. The pleiotropic response has been well characterized. BMPs stimulate osteogenic and chondrogenic phenotypes. Natural bovine Osteogenin (BMP-3) and recombinant BMP-4 are equipotent in chemotaxis, limb bud chondrogenesis, cartilage maintenance, and in vivo bone induction
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Osteogenin (bone morphogenic protein 3) inhibits proliferation and stimulates differentiation of osteoprogenitors in human bone marrow
Differentiation, 2002Co-Authors: Joëlle Amédée, Reine Bareille, F. Rouais, N. S. Cunningham, Harri Reddi, Marie-françoise HarmandAbstract:Treatment of human bone marrow osteoprogenitors with Osteogenin (BMP-3; at 1, 2.5 and 10 ng/ml) caused dose- and time-dependent inhibition of DNA synthesis and cell proliferation. Simultaneously, Osteogenin stimulated type I collagen synthesis and cAMP production. Addition of Osteogenin to the cell culture increased intracellular alkaline phosphatase activity and osteocalcin synthesis, with maximal stimulation at 2.5 ng/ml. Simultaneous addition of 2.5 ng/ml Osteogenin and 1,25 dihydroxy vitamin D3 (10(-8) M) enhanced the stimulation observed in osteocalcin synthesis. The experiments reported here demonstrate the significant "in vitro" influence of Osteogenin in the stimulation of osteogenic phenotype in osteoprogenitor cells which have been isolated from human bone marrow and cloned. These results support a reciprocal relationship between cell growth inhibition and expression of osteoblast differentiation.
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Tricalcium phosphate and Osteogenin: a bioactive onlay bone graft substitute.
Plastic and Reconstructive Surgery, 1995Co-Authors: Arnold S. Breitbart, N. S. Cunningham, A. H. Reddi, David A. Staffenberg, Charles H. Thorne, Paul M. Glat, John L. Ricci, German C. SteinerAbstract:The disadvantages of autogenous bone grafts has prompted a search for a dependable onlay bone graft substitute. A combination of tricalcium phosphate, a resorbable ceramic, and Osteogenin, an osteoinductive protein, was evaluated as an onlay bone graft substitute in a rabbit calvarial model. Twenty-eight tricalcium phosphate implants (15 mm diameter X 5 mm ; pore size, 100-200 μm) were divided into experimental and control groups and placed on the frontal bone of 14 adult New Zealand White rabbits. In the experimental animals, 185 μg of Osteogenin was added to each implant. In the control animals, the implants were placed untreated. Implants were harvested at intervals of 1, 3, and 6 months, and evaluated using hematoxylin and eosin histology, microradiography, and histomorphometric scanning electron microscope backscatter image analysis. At 1 month there was minimal bone ingrowth and little tricalcium phosphate resorption in both the Osteogenin-treated and control implants. At 3 months, both the Osteogenin-treated and control implants showed a modest increase in bone ingrowth (8.85 percent versus 5.87 percent) and decrease in tricalcium phosphate (32.86 percent versus 37.08 percent). At 6 months, however, the Osteogenin-treated implants showed a statistically significant increase in bone ingrowth (22.33 percent versus 6.96 percent ; p = 0.000) and decrease in tricalcium phosphate (27.25 percent versus 37.80 percent ; p = 0.004) compared with the control implants. The bone within the control implants was mostly woven at 6 months, whereas the Osteogenin-treated implants contained predominantly mature lamellar bone with well-differentiated marrow. All implants maintained their original volume at each time interval studied. The tricalcium phosphate/Osteogenin composite, having the advantage of maintaining its volume and being replaced by new bone as the tricalcium phosphate resorbs, may be applicable clinically as an onlay bone graft substitute.
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Osteoclast recruiting activity in bone matrix
Bone and Mineral, 1994Co-Authors: T.a. Hentunen, N. S. Cunningham, A. H. Reddi, O. Vuolteenaho, H.k. VäänänenAbstract:Abstract An activity that recruits osteoclasts has been identified and partially characterized from bone matrix. Bone-derived osteoclast recruiting activity (BORA) was co-purified with Osteogenin, a bone inductive protein. Osteogenin was extracted from bovine bone with 6 M urea and purified by chromatography on hydroxyapatite, heparin-Sepharose and Sephacryl S-200 gel filtration. The biologically active osteoclast formation-stimulating material was further purified by C 18 reverse phase HPLC. BORA is obviously distinct from Osteogenin and transforming growth factor β (TGF- β ), since further purified Osteogenin and pure TGF- β did not stimulate the formation of osteoclast-like cells. BORA (0.1–10 μ g/ml) stimulated the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells (MNC) in a dose-dependent manner. These multinucleated cells resorbed bone when cultured on bovine bone slices. The effect of BORA is primarily directed to differentiate osteoclast precursors, since it did not stimulate osteoclast function in in vitro resorption assay where disaggregated rat osteoclasts were cultured on bovine bone slices. However, after 24 h preincubation with 50 nM PTH in the mouse calvaria assay, BORA at 10 μ g/ml significantly stimulated bone resorption.
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Reconstruction of the Bone-Bone Marrow Organ by Osteogenin, a Bone Morphogenetic Protein, and Demineralized Bone Matrix in Calvarial Defects of Adult Primates
Plastic and Reconstructive Surgery, 1993Co-Authors: Ugo Ripamonti, N. S. Cunningham, Laura Yeates, A. H. ReddiAbstract:Information concerning the efficacy of Osteogenin, a bone morphogenetic protein, and demineralized bone matrix in orthotopic sites in nonhuman primates is a prerequisite for potential clinical application in humans. After exposure of the calvaria, 84 cranial defects, 25 mm in diameter, were prepared in 26 adult male baboons (Papio ursinus). Defects were implanted with insoluble collagenous bone matrix (ICBM, the inactive collagenous residue after dissociative extraction of bone matrix with 4 M guanidine hydrochloride) reconstituted with Osteogenin fractions isolated from baboon bone matrix by chromatography on heparin-Sepharose and hydroxyapatite-Ultrogel (Og Hep-HA) or Osteogenin further purified using Sephacryl S-200 gel filtration chromatography (Og S-200). Baboon Osteogenin with the highest biologic activity in a rodent bioassay, as determined by alkaline phosphatase activity, calcium content, and histologic analysis, was used for orthotopic implantation in baboons. Additional defects were implanted with baboon demineralized bone matrix (DBM) or ICBM without Osteogenin as control. Defects also were grafted with corticocancellous bone harvested from the iliac crest or left ungrafted to monitor the spontaneous regeneration potential of the adult baboon calvaria. Undecalcified bone sections at 7 microns were prepared from the harvested specimens 30 and 90 days after surgery. Histomorphometry demonstrated that Og S-200 induced copious amounts of bone and osteoid as early as day 30 (P < 0.01 versus ICBM, autogenous grafts and untreated defects). At day 90, in implants of Og S-200, Og Hep-HA, and DBM, bone and marrow formation was extensive, culminating in complete regeneration of the craniotomies. In implants of DBM, bone formed with an intervening phase of cartilage development. This provides the phenotypic evidence of endochondral bone differentiation by induction in defects of membranous calvarial bone in adult primates. These results establish the potential therapeutic application of Osteogenin and demineralized bone matrix for the architectural reconstruction of the bone-bone marrow organ in humans.
