RESUMO
BACKGROUND: The growing use of zirconia as a ceramic material in dentistry is attributed to its biocompatibility, mechanical properties, esthetic appearance, and reduced bacterial adhesion. These favorable properties make ceramic materials a viable alternative to commonly used titanium alloys. Mimicking the physiological properties of blood flow, particularly the mechanosignaling in endothelial cells (ECs), is crucial for enhancing our understanding of their role in the response to zirconia exposure. METHODS: In this study, EC cultures were subjected to shear stress while being exposed to zirconia for up to 3 days. The conditioned medium obtained from these cultures was then used to expose osteoblasts for a duration of 7 days. To investigate the effects of zirconia on osteoblasts, we examined the expression of genes associated with osteoblast differentiation, including Runx2, Osterix, bone sialoprotein, and osteocalcin genes. Additionally, we assessed the impact of mechanosignaling-related angiocrine factors on extracellular matrix (ECM) remodeling by measuring the activities of matrix metalloproteinases 2 and 9 (MMP2 and MMP9) during the acquisition of the osteogenic phenotype, which precedes mineralization. RESULTS: Our data revealed that mechanosignaling-related angiocrine factors play a crucial role in promoting an osteoblastic phenotype in response to zirconia exposure. Specifically, exposed osteoblasts exhibited significantly higher expression levels of genes associated with osteoblast differentiation, such as Runx2, Osterix, bone sialoprotein, and osteocalcin genes. Furthermore, the activities of MMP2 and MMP9, which are involved in ECM remodeling, were modulated by mechanosignaling-related angiocrine factors. This modulation is likely an initial event preceding the mineralization phase. CONCLUSION: Based on our findings, we propose that mechanosignaling drives the release of angiocrine factors capable of modulating the osteogenic phenotype at the biointerface with zirconia. This process creates a microenvironment that promotes wound healing and osseointegration. Moreover, these results highlight the importance of considering the mechanosignaling of endothelial cells in the modulation of bone healing and osseointegration in the context of blood vessel effects. Our data provide new insights and open avenues for further investigation into the influence of mechanosignaling on bone healing and the osseointegration of dental devices.
Assuntos
Subunidade alfa 1 de Fator de Ligação ao Core , Células Endoteliais , Osteocalcina/genética , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/farmacologia , Sialoproteína de Ligação à Integrina/genética , Sialoproteína de Ligação à Integrina/metabolismo , Sialoproteína de Ligação à Integrina/farmacologia , Células Endoteliais/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Fenótipo , Diferenciação Celular , Osteoblastos/metabolismo , Titânio/farmacologia , Propriedades de SuperfícieRESUMO
OBJECTIVE: To define the potential of polycaprolactone (PCL) scaffold for cementoblast delivery. BACKGROUND: Dental cementum is critical for tooth attachment and position, and its regenerative capabilities remain unpredictable. METHODS: PCL scaffolds were manufactured by the electrospinning technique at 10% and 20% (w/v) and seeded with cementoblasts (OCCM-30). Scaffolds were characterized for their morphology and biological performance by scanning electron microscopy (SEM), confocal and conventional histology, cytocompatibility (PrestoBlue assay), gene expression (type I collagen - Col1; bone sialoprotein - Bsp; runt-related transcription factor 2 - Runx-2; alkaline phosphatase - Alpl; osteopontin - Opn; osteocalcin - Ocn, osterix - Osx), and the potential to induce extracellular matrix deposition and mineralization in vitro. RESULTS: Overall, data analysis showed that PCL scaffolds allowed cell adhesion and proliferation, modulated the expression of key markers of cementoblasts, and led to enhanced extracellular matrix deposition and calcium deposition as compared to the control group. CONCLUSION: Altogether, our findings allow concluding that PCL scaffolds are a viable tool to culture OCCM-30 cells, leading to an increased potential to promote mineralization in vitro. Further studies should be designed in order to define the clinical relevance of cementoblast-loaded PCL scaffolds to promote new cementum formation.
Assuntos
Materiais Biocompatíveis , Cemento Dentário , Diferenciação Celular , Sialoproteína de Ligação à Integrina/metabolismo , Poliésteres , Alicerces TeciduaisRESUMO
The Solanum glaucophyllum Desf. has been used to treat and prevent diseases in human and veterinary medicine. On the other hand, plant poisoning causes several bone diseases, among them osteoporosis, which is characterized by osteoblastic hypoplasia. Because the osteoblast is a cell derived from the differentiation of mesenchymal stem cells (MSCs) from bone marrow, the hypothesis is that the plant reduces the osteogenic differentiation of MSCs. The objective of this study was to evaluate the effects of S. glaucophyllum Desf. extract on MSCs cultured in osteogenic differentiation medium. We determined by liquid chromatography that 1 ml of plant extract contained 3.8 µl of 1,25(OH)2 D3 (calcitriol). Four groups of MSCs cultivated in osteogenic medium were evaluated as follows: (a) treated with 100 µl of extract/L containing 0.4 µg/L of calcitriol; (b) treated with 1 ml of extract/L containing 4 µg/L of calcitriol; (c) treated with 5 ml of extract/L containing 20 µg/L of calcitriol; and (d) a control group without extract. We performed alkaline phosphatase activity assay, analysis of MTT conversion to formazan, and evaluated the percentage of cells, and number and diameter of mineralization nodules. The expression of gene transcripts for osteopontin, bone sialoprotein and BMP-2 was analysed by RT-qPCR. After 21 days, there was a significant reduction in MTT conversion to formazan in treated groups, of the cellularity in the group with 5 ml of extract/L, and in the number and size of mineralization nodules in the groups treated with 1 and 5 ml of extract/L. The 5 ml extract/L concentration also reduced transcript expression of osteopontin. It is concluded that S. glaucophyllum Desf. at concentrations of 1 and 5 ml extract/L reduced mineralized matrix synthesis in MSCs cultivated in osteogenic differentiation medium, which suggests that this is one of the mechanisms by which osteoporosis occurs in intoxicated animals.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Extratos Vegetais/farmacologia , Solanum glaucophyllum/química , Fosfatase Alcalina/genética , Fosfatase Alcalina/metabolismo , Animais , Proteína Morfogenética Óssea 2/genética , Proteína Morfogenética Óssea 2/metabolismo , Diferenciação Celular/fisiologia , Relação Dose-Resposta a Droga , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Sialoproteína de Ligação à Integrina/genética , Sialoproteína de Ligação à Integrina/metabolismo , Células-Tronco Mesenquimais/fisiologia , Osteopontina/genética , Osteopontina/metabolismo , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , RatosRESUMO
The hypothesis of this experiment is that mesenchymal stem cells (MSCs) are involved in the genesis of the bone metaplasia caused by Solanum glaucophyllum intoxication. We determined using liquid chromatography that 1â¯mL of plant extract contained 3.8⯵l of 1,25(OH)2D3. The ability of 100⯵L, 1â¯mL and 5â¯mL of extract/L, containing 1â¯nM (0.4⯵g/L), 10â¯nM (4⯵g/L) and 50â¯nM (20⯵g/L) of 1,25(OH)2D3, respectively, in inducing the osteogenic differentiation in bone marrow MSCs from rats was tested. At the concentrations of 1 and 5â¯mL of extract/L of culture medium without osteogenesis-inducing factors, the plant extract induced the osteogenic differentiation of the MSCs, as was evidenced by the greater synthesis of mineralized matrix. At the higher concentration (5â¯mL of extract/L), an increase in the relative expression of BMP-2 gene was observed. It was concluded that rat bone marrow MSC culture is a good model for studying the effects of the S. glaucophyllum extract on the osteogenic differentiation of undifferentiated cells. Also, S. glaucophyllum extracts containing 10â¯nM (4⯵g/L) and 50â¯nM (20⯵g/L) of 1,25(OH)2D3 induce the osteogenic differentiation of MSCs, suggesting that this is one of the mechanisms by which S. glaucophyllum causes bone metaplasia.
Assuntos
Células-Tronco Mesenquimais/efeitos dos fármacos , Metaplasia/induzido quimicamente , Extratos Vegetais/toxicidade , Solanum glaucophyllum/química , Animais , Proteína Morfogenética Óssea 2/metabolismo , Osso e Ossos/patologia , Cromatografia Líquida , Sialoproteína de Ligação à Integrina/metabolismo , Células-Tronco Mesenquimais/patologia , Osteopontina/metabolismo , Ratos , Testes de ToxicidadeRESUMO
Carbon nanotubes combine high bend and mechanical strength, which is advantageous for many structural and biomedical purposes. Recently, some biomaterials, based on carbon nanostructures and nanohydroxyapatite (nHAp), have been investigated as bone substitutes in order to improve regeneration. The aim of this study was to access the expression of some RNA transcripts (involved in the process of osteoblast differentiation) by mesenchymal stem cells cultured over different nanocomposite surfaces. A multi-walled carbon nanotube (MWCNT) was firstly grown using chemical vapor deposition and then exfoliated using chemical and oxygen plasma treatments to obtain graphene nanoribbons (GNR). The hybrid composites nHAp/GNR were prepared using the wet method assisted by ultrasound irradiation with different amounts of GNR (1.0, 2.0 and 3.0 wt %). Five groups were tested in cell cultures. Group 1: synthesized nHAp; Group 2: synthesized GNR; Group 3: nHAp and 1.0% of GNR; Group 4: nHAp and 2.0% of GNR and group 5: nHAp and 3.0% of GNR. Real time reverse transcription polymerase chain reactions were performed, and all data was submitted to Kruskal Wallis and Dunn tests, at a significance level of 5%. As a result, three nanocomposites with different proportions of GNR were successfully produced. After cell culture, the expression of osteogenic genes demonstrated no significant differences among the groups and periods. However, bone morphogenetic protein II (BMP II), integrin binding sialoprotein (IBSP), and Osterix highest expressions were observed in the group containing 3.0% of GNR. In conclusion, our hybrid composites may be useful in bone interventions requiring mesenchymal stem cell differentiation into osteoblasts for healing.
Assuntos
Durapatita/química , Grafite/química , Nanotubos de Carbono/química , Osteogênese , Engenharia Tecidual/métodos , Bioensaio , Proteína Morfogenética Óssea 2/metabolismo , Células Cultivadas , Humanos , Sialoproteína de Ligação à Integrina/metabolismo , Células-Tronco Mesenquimais/citologia , Nanocompostos/química , Osteoblastos/citologia , Oxigênio/química , RNA/análise , Fator de Transcrição Sp7/metabolismo , Estresse Mecânico , Alicerces Teciduais/químicaRESUMO
Differential diagnosis among fibrous dysplasias, cemento-ossifying fibromas and cemento-osseous dysplasias is difficult, since there is considerable overlap of histologic features, but also extremely important, since they differ greatly in etiology, clinical behaviour, prognosis and terapeuthic approach. There is no data about the use of immunohistochemistry, a viable and accessible technique, for this purpose. The objective of this study was to investigate, comparatively, the immunohistochemical expression of major non-collagenous proteins (osteonectin [ON], osteopontin [OP], bone sialoprotein [BSP] and osteocalcin [OC]) of mineralized tissue extracellular matrix in 22 cases of fibrous dysplasias, 16 of cemento-ossifying fibromas and 16 of cemento-osseous dysplasias. ON maintained the same expression profile in all cases; the staining for OP was negative in fusiform cells producing cementoid globules and weak, as well as heterogeneous, in high mineralized matrixes; there was negativity for BSP in cementoid globules and in the fusiform cells that produce them, differently from the strong positive expression found in the majority of bone trabeculae and their peripheral cuboidal osteoblasts; and finally, the immuno-reactivity for OC was weak, except in cuboidal osteoblasts and osteocytes. We can conclude that the nature of mineralized structure and the cellular phenotype are much more responsible for variability in immunohistochemical profile than the type of lesion (fibrous dysplasias, cemento-ossifying fibromas and cemento-osseous dysplasias) which makes difficult, at least for a while, the use of these proteins with diagnosis purpose.
Assuntos
Cementoma/diagnóstico , Fibroma Ossificante/diagnóstico , Displasia Fibrosa Óssea/diagnóstico , Sialoproteína de Ligação à Integrina/metabolismo , Osteocalcina/metabolismo , Osteonectina/metabolismo , Osteopontina/metabolismo , Osso e Ossos/patologia , Cementoma/metabolismo , Cementoma/patologia , Diagnóstico Diferencial , Fibroma Ossificante/metabolismo , Fibroma Ossificante/patologia , Displasia Fibrosa Óssea/metabolismo , Displasia Fibrosa Óssea/patologia , HumanosRESUMO
Mast cells are multifunctional immune cells that participate in many important processes such as defense against pathogens, allergic reactions, and tissue repair. These cells perform their functions through the release of a wide variety of mediators. This release occurs mainly through cross-linking IgE (immunoglobulin E) bound to high affinity IgE receptors by multivalent antigens. The abundance of mast cells in connective tissue, surrounding blood vessels, and their involvement in the early stages of bone repair support the possibility of physiological and pathological interactions between mast cells and osteoblasts. However, the participation of mast cell mediators in osteogenesis is not fully understood. Therefore, the objective of this work was to investigate the role of mast cell mediators in the acquisition of the osteogenic phenotype in vitro. The results show that pooled mast cell mediators can affect proliferation, morphology, and cytoskeleton of osteoblastic cells, and impair the activity and expression of alkaline phosphatase as well as the expression of bone sialoprotein. Also, mast cell mediators inhibit the expression of mRNA for those proteins and inhibit the formation and maturation of calcium nodules and consequently inhibit mineralization. Therefore, mast cell mediators can modulate osteogenesis and are potential therapeutic targets for treatments of bone disorders.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Mastócitos/citologia , Mastócitos/efeitos dos fármacos , Minerais/metabolismo , Osteoblastos/citologia , Citoesqueleto de Actina/efeitos dos fármacos , Citoesqueleto de Actina/metabolismo , Fosfatase Alcalina/genética , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Sialoproteína de Ligação à Integrina/genética , Sialoproteína de Ligação à Integrina/metabolismo , Mastócitos/metabolismo , Osteoblastos/efeitos dos fármacos , Osteopontina/genética , Transporte Proteico/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RatosRESUMO
We aimed to evaluate the in vitro osteogenic and osteoinductive potentials of BioS-2P and its ability to promote in vivo bone repair. To investigate osteogenic potential, UMR-106 osteoblastic cells were cultured on BioS-2P and Bioglass 45S5 discs in osteogenic medium. The osteoinductive potential was evaluated using mesenchymal stem cells (MSCs) cultured on BioS-2P, Bioglass 45S5 and polystyrene in non-osteogenic medium. Rat bone calvarial defects were implanted with BioS-2P scaffolds alone or seeded with MSCs. UMR-106 proliferation was similar for both materials, while alkaline phosphatase (ALP) activity and mineralization were higher for BioS-2P. Bone sialoprotein (BSP), RUNX2 and osteopontin (OPN) gene expression and BSP, OPN, ALP and RUNX2 protein expression were higher on BioS-2P. For MSCs, ALP activity was higher on Bioglass 45S5 than on BioS-2P and was lower on polystyrene. All genes were highly expressed on bioactive glasses compared to polystyrene. BioS-2P scaffolds promoted in vivo bone formation without differences in the morphometric parameters at 4, 8 and 12 weeks. After 8 weeks, the combination of BioS-2P with MSCs did not increase the quantity of new bone compared to the BioS-2P alone. To stimulate osteoblast activity, drive MSC differentiation and promote bone formation, BioS-2P is a good choice as a scaffold for bone tissue engineering.
Assuntos
Osso e Ossos/metabolismo , Cerâmica/química , Vidro/química , Células-Tronco Mesenquimais/citologia , Engenharia Tecidual/métodos , Fosfatase Alcalina/metabolismo , Animais , Regeneração Óssea , Linhagem Celular , Células Cultivadas , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Regulação da Expressão Gênica , Sialoproteína de Ligação à Integrina/metabolismo , Teste de Materiais , Osteogênese , Poliestirenos/química , Ratos , Alicerces Teciduais , Difração de Raios XRESUMO
Abstract This study aimed to investigate the influence of a three-dimensional cell culture model and bioactive glass (BG) particles on the expression of osteoblastic phenotypes in rat calvaria osteogenic cells culture. Cells were seeded on two-dimensional (2D) and three-dimensional (3D) collagen with BG particles for up to 14 days. Cell viability and alkaline phosphatase (ALP) activity was performed. Cell morphology and immunolabeling of noncollagenous bone matrix proteins were assessed by epifluorescence and confocal microscopy. The expressions of osteogenic markers were analyzed using RT-PCR. Mineralized bone-like nodule formation was visualized by microscopy and calcium content was assessed quantitatively by alizarin red assay. Experimental cultures produced a growing cell viability rate up to 14 days. Although ALP activity at 7 days was higher on BG cultures, cells on 3D and 3D+BG had an activity decrease of ALP at 14 days. Three-dimensional conditions favored the immunolabeling for OPN and BSP and the expression of ALP and COL I mRNAs. BG particles influenced positively the OC and OPN mRNAs expression and calcified nodule formation in vitro. The results indicated that the 3D cultures and BG particles contribute to the expression of osteoblastic phenotype and to differentiated and mineralized matrix formation.
Resumo O objetivo deste estudo foi investigar a influência do modelo de cultura celular tridimensional e das partículas de vidro bioativo (BG) sobre a expressão fenotípica de culturas de células osteogênicas da calvária de ratos. As células foram mantidas em culturas sobre superfícies colágenas bi-dimensionais (2D) e em géis de colágeno tridimensional (3D) com e sem partículas de BG até 14 dias. Foram avaliadas: viabilidade celular, atividade de fosfatase alcalina (ALP), morfologia celular e imunomarcação de proteínas da matriz não-colágena do osso através de epifluorescência e microscopia confocal. As expressões de marcadores osteogênicos foram analisadas utilizando RT-PCR. A formação de nódulos mineralizados foi visualizada através de microscopia e o conteúdo de cálcio foi avaliado quantitativamente pelo Alizarina Red. As culturas experimentais produziram uma taxa crescente de viabilidade até 14 dias. Embora a atividade ALP em 7 dias tenha sido maior em culturas com BG, as células em 3D e 3D+BG apresentaram uma diminuição da atividade ALP aos 14 dias. As condições tridimensionais favoreceram a imunomarcação para OPN e BSP e a expressão de mRNAs para ALP e COL I. As partículas de BG influenciaram positivamente a expressão do mRNAs para OPN e OC e a formação de nódulos calcificados in vitro. Os resultados indicaram que as culturas em 3D e partículas BG contribuíram para a expressão do fenótipo osteoblástico e para a diferenciação e formação de matriz mineralizada.
Assuntos
Animais , Materiais Biocompatíveis , Vidro , Osteoblastos/citologia , Osteogênese , Crânio/citologia , Fosfatase Alcalina/genética , Fosfatase Alcalina/metabolismo , Biomarcadores/metabolismo , Cálcio/metabolismo , Técnicas de Cultura de Células , Sobrevivência Celular , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Técnica Indireta de Fluorescência para Anticorpo , Perfilação da Expressão Gênica , Sialoproteína de Ligação à Integrina/metabolismo , Microscopia Confocal , Microscopia de Fluorescência , Osteoblastos/enzimologia , Osteoblastos/metabolismo , Osteopontina/metabolismo , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , RNA Mensageiro/genética , Crânio/enzimologia , Crânio/metabolismo , Alicerces TeciduaisRESUMO
This study aimed to investigate the influence of a three-dimensional cell culture model and bioactive glass (BG) particles on the expression of osteoblastic phenotypes in rat calvaria osteogenic cells culture. Cells were seeded on two-dimensional (2D) and three-dimensional (3D) collagen with BG particles for up to 14 days. Cell viability and alkaline phosphatase (ALP) activity was performed. Cell morphology and immunolabeling of noncollagenous bone matrix proteins were assessed by epifluorescence and confocal microscopy. The expressions of osteogenic markers were analyzed using RT-PCR. Mineralized bone-like nodule formation was visualized by microscopy and calcium content was assessed quantitatively by alizarin red assay. Experimental cultures produced a growing cell viability rate up to 14 days. Although ALP activity at 7 days was higher on BG cultures, cells on 3D and 3D+BG had an activity decrease of ALP at 14 days. Three-dimensional conditions favored the immunolabeling for OPN and BSP and the expression of ALP and COL I mRNAs. BG particles influenced positively the OC and OPN mRNAs expression and calcified nodule formation in vitro. The results indicated that the 3D cultures and BG particles contribute to the expression of osteoblastic phenotype and to differentiated and mineralized matrix formation.