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‣ A possible mechanism of low molecular weight protein tyrosine phosphatase (LMW-PTP) activity modulation by glutathione action during human osteoblast differentiation

MALASPINA, Tatiana Salles de Souza; ZAMBUZZI, Willian Fernando; SANTOS, Celio Xavier dos; CAMPANELLI, Ana Paula; LAURINDO, Francisco Rafael Martins; SOGAYAR, Mari Cleide; GRANJEIRO, Jose Mauro
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
362.82152%
Objective: Low molecular weight protein tyrosine phosphatases (LMW-PTPs) are a family of enzymes strongly involved in the regulation of cell growth and differentiation. Since there is no information concerning the relationship between osteoblastic differentiation and LMW-PTP expression/activity, we investigated its involvement during human osteoblast-like cells (hFOB 1.19) differentiation. It is known that LMW-PTP is regulated by an elegant redox mechanism, so we also observed how the osteoblastic differentiation affected the reduced glutathione levels. Design: hFOB 1.19 cells were cultured in DMEM/F12 up to 35 days. The osteoblast phenotype acquisition was monitored by measuring alkaline phosphatase activity and mineralized nodule formation by Von Kossa staining. LMW-PTP activity and expression were measured using the p-nitrophenylphosphate as substrate and Western blotting respectively. Crystal violet assay determined the cell number in each experimental point. Glutathione level was determined by both HPLC and DNTB assays. Results: LMW-PTP modulation was coincident with the osteoblastic differentiation biomarkers, such as alkaline phosphatase activity and presence of nodules of mineralization in Vitro. Likewise LMW-PTP, the reduced glutathione-dependent microenvironment was modulated during osteoblastic differentiation. During this process...

‣ Ascorbate-induced osteoblast differentiation recruits distinct MMP-inhibitors: RECK and TIMP-2

ZAMBUZZI, Willian F.; YANO, Claudia L.; CAVAGIS, Alexandre D. M.; PEPPELENBOSCH, Maikel P.; GRANJEIRO, Jose Mauro; FERREIRA, Carmen V.
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
362.82152%
The bone formation executed by osteoblasts represents an interesting research field both for basic and applied investigations. The goal of this work was to evaluate the molecular mechanisms involved during osteoblast differentiation in vitro. Accordingly, we demonstrated that, during the osteoblastic differentiation, TIMP-2 and RECK presented differential expressions, where RECK expression was downregulated from the 14th day in contrast with an increase in TIMP-2. Concomitantly, our results showed a temporal regulation of two major signaling cascades during osteoblast differentiation: proliferation cascades in which RECK, PI3 K, and GSK-3 beta play a pivotal role and latter, differentiation cascades with participation of Ras, Rho, Rac-1, PKC alpha/beta, and TIMP-2. Furthermore, we observed that phosphorylation level of paxillin was downregulated while FAK(125) remained unchangeable, but active during extracellular matrix (ECM) remodeling. Concluding, our results provide evidences that RECK and TIMP-2 are involved in the control of ECM remodeling in distinct phases of osteoblast differentiation by modulating MMP activities and a multitude of signaling proteins governs these events.; FAPESP Fundacao de Amparo a Pesquisa do Estado de Sao Paulo[04/14906-2]

‣ The Thyroid Hormone Receptor (TR) beta-Selective Agonist GC-1 Inhibits Proliferation But Induces Differentiation and TR beta mRNA Expression in Mouse and Rat Osteoblast-Like Cells

BEBER, Eduardo H.; CAPELO, Luciane P.; FONSECA, Tatiana L.; COSTA, Cristiane C.; LOTFI, Claudimara F.; SCANLAN, Thomas S.; GOUVEIA, Cecilia H. A.
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
362.82152%
Previous studies showed anabolic effects of GC-1, a triiodothyronine (T3) analogue that is selective for both binding and activation functions of thyroid hormone receptor (TR) beta 1 over TR alpha 1, on bone tissue in vivo. The aim of this study was to investigate the responsiveness of rat (ROS17/2.8) and mouse (MC3T3-E1) osteoblast-like cells to GC-1. As expected, T3 inhibited cellular proliferation and stimulated mRNA expression of osteocalcin or alkaline phosphatase in both cell lineages. Whereas equimolar doses of T3 and GC-1 equally affected these parameters in ROS17/2.8 cells, the effects of GC-1 were more modest compared to those of T3 in MC3T3-E1 cells. Interestingly, we showed that there is higher expression of TR alpha 1 than TR beta 1 mRNA in rat (similar to 20-90%) and mouse (similar to 90-98%) cell lineages and that this difference is even higher in mouse cells, which highlights the importance of TR alpha 1 to bone physiology and may partially explain the modest effects of GC-1 in comparison with T3 in MC3T3-E1 cells. Nevertheless, we showed that TR beta 1 mRNA expression increases (similar to 2.8- to 4.3-fold) as osteoblastic cells undergo maturation, suggesting a key role of TR beta 1 in mediating T3 effects in the bone forming cells...

‣ Hedgehog signaling and osteoblast gene expression are regulated by purmorphamine in human mesenchymal stem cells

Oliveira, F. S.; Bellesini, L. S.; Defino, H. L. A.; da Silva Herrero, C. F.; Beloti, M. M.; Rosa, A. L.
Fonte: WILEY-BLACKWELL; MALDEN Publicador: WILEY-BLACKWELL; MALDEN
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
364.91555%
Several biological events are controlled by Hedgehog (Hh) signaling, including osteoblast phenotype development. This study aimed at evaluating the gene expression profile of human mesenchymal stem cells (hMSCs) treated with the Hh agonist, purmorphamine, focusing on Hh signaling and osteoblast differentiation. hMSCs from bone marrow were cultured in non-osteogenic medium with or without purmorphamine (2 mu M) for periods of up to 14 days. Purmorphamine up-regulated gene expression of the mediators of Hh pathway, SMO, PTCH1, GLI1, and GLI2. The activation of Hh pathway by purmorphamine increased the expression of several genes (e.g., RUNX2 and BMPs) related to osteogenesis. Our results indicated that purmorphamine triggers Hh signaling pathway in hMSCs, inducing an increase in the expression of a set of genes involved in the osteoblast differentiation program. Thus, we conclude that Hh is a crucial pathway in the commitment of undifferentiated cells to the osteoblast lineage. J. Cell. Biochem. 113: 204208, 2012. (C) 2011 Wiley Periodicals, Inc.; State of Sao Paulo Research Foundation (FAPESP, Brazil); State of Sao Paulo Research Foundation (FAPESP), Brazil

‣ Platelet-rich plasma stimulates cytokine expression and alkaline phosphatase activity in osteoblast-derived osteosarcoma cells

Herrera, Bruno S.; Coimbra, Leila S.; Bastos, Alliny S.; Teixeira, Simone Aparecida; Steffens, Joao P.; Muscara, Marcelo Nicolas; Spolidorio, Luís Carlos
Fonte: PERGAMON-ELSEVIER SCIENCE LTD; OXFORD Publicador: PERGAMON-ELSEVIER SCIENCE LTD; OXFORD
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
355.6419%
Objective: The aim of this study was to investigate the effects of PRP on SAOS-2 cells in terms of cytokine expression, cell activity and oxidative stress. Design: Cell line SAOS-2 (1 x 10(5) cells/mL) were grown in culture medium alpha-MEM with 10% FBS for 24 h and stimulated (or not) with PRP at concentrations of 3, 10 and 20%, LPS (E. coli, 10 g/mL) and IL-1 beta (1 mg/mL) for 24 h. The supernatant was collected and analyzed for the expression of cytokines in a panel array, ALP using a commercial kit and NO2- with Griess reaction method. Also, the cells were analyzed using Western blot for RANKL and slot blotting for nitrotyrosine expression. Result: There were no significant differences amongst the groups in terms of NO2-, protein nitrotyrosine content and RANKL expression. However, all stimuli increased ALP activity and in case of PRP, it was in a dose-dependent manner (p < 0.001). Also, all stimuli induced an increase in cytokines and chemokines expression, but only PRP promoted an increase of component C5, sICAM-1 and RANTES expression. Whilst IL-1 receptor antagonist (IL-1ra) expression was down-regulated by PRP, both LPS and IL-1 beta caused up-regulation of this cytokine. Conclusions: PRP can stimulate osteoblast activity and cytokine/chemokine release...

‣ Osteoblast Adhesion Dynamics: A Possible Role for ROS and LMW-PTP

Fernandes, Gustavo V. O.; Cavagis, Alexandre D. M.; Ferreira, Carmen V.; Olej, Beni; Leao, Mauricio de Souza; Yano, Claudia L.; Peppelenbosch, Maikel; Granjeiro, Jose Mauro; Zambuzzi, Willian F.
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica Formato: 1063-1069
Português
Relevância na Pesquisa
364.91555%
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Reactive oxygen species (ROS) modulate a variety of intracellular events, but their role in osteoblast adhesion and spreading remains unclear. ROS is a very-known physiological modulators of Protein Tyrosine Phosphatases activities, mainly to low molecular weight protein tyrosine phosphatase (LMW-PTP) activity. As this biological mechanism is not clear in osteoblast adhesion, we decided to investigate ROS levels and phosphorylations of FAK and Src, identifying these proteins as potential substrates to LMW-PTP activity. Our results showed that during osteoblast adhesion/spreading (30min and 2h of seeding) the intracellular ROS content (hydrogen peroxide) is finely regulated by an effective anti-oxidant system [catalase and Superoxide Dismutase (SOD) activities were evaluated]. During the first 30min of adhesion, there was an increase in ROS production and a concomitant increase in focal adhesion kinase (FAK) activity after its phosphorylation at Tyrosine 397 (Y-397). Moreover, after 2h there was a decrease in ROS content and FAK phosphorylation. There was no significant change in LMW-PTP expression at 30min or 2h. In order to validate our hypothesis that LMW-PTP is able to control FAK activity by modulating its phosphorylation status...

‣ Flavinas promovem mudanças na matriz extracelular, vias de transdução de sinal, enzimas antioxidantes e metaloproteinases durante a diferenciação de osteoblastos; Flavins promote changes in the extracellular matrix, signal transduction, antioxidant enzymes and metalloproteinases during osteoblast differentiation

Antonio Hernandes Chaves Neto
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 30/10/2009 Português
Relevância na Pesquisa
362.82152%
Riboflavina (Rb – Vitamina B2) é o precursor das flavocoenzimas essenciais flavina mononucleotídeo (FMN) e flavina adenina dinucleotídeo (FAD). Estas coenzimas participam de processos enzimáticos dependentes das reações de transferências de elétrons, que ocorrem nas vias de produção de energia, biossíntese, desintoxicação e sequestro de elétrons. O aumento dietético da riboflavina e piridoxina foi associado com maiores densidades minerais em mulheres e homens idosos. Fotoderivados da riboflavina demonstraram efeitos citotóxicos em células cancerosas de próstata e leucemias, entretanto, o efeito direto da Rb e seus fotoderivados em osteoblastos não foram examinados. Neste trabalho os efeitos biológicos da Rb e riboflavina irradiada (IRb) foram investigados na linhagem de pré-osteoblastos MC3T3-E1, um modelo bem aceito de osteogênese in vitro caracterizado pela indução de genes específicos associados com o fenótipo osteoblástico quando tratados com ácido ascórbico e β-glicerofosfato. A viabilidade celular foi avaliada através da redução do MTT, da incorporação do corante vermelho neutro e do conteúdo de ácidos nucléicos. Marcadores de diferenciação osteoblástica foram analisados através do RT-PCR semi-quantitativo (osteopontina e osteocalcina) e através de análises colorimétricas de atividade da fosfatase alcalina (FAL) e síntese de colágeno pela coloração de picrosirius. As atividades das metaloproteinases (MMP) -9 e -2 foram avaliadas pela zimografia de gelatina. Microarranjos de peptídeos com subtratos específicos para quinases e imunoblotting foram usados para identificar os efeitos na sinalização celular. As atividades de enzimas antioxidantes (superóxido dismutase...

‣ A possible mechanism of low molecular weight protein tyrosine phosphatase (LMW-PTP) activity modulation by glutathione action during human osteoblast differentiation

MALASPINA, Tatiana Salles de Souza; ZAMBUZZI, Willian Fernando; SANTOS, Celio Xavier dos; CAMPANELLI, Ana Paula; LAURINDO, Francisco Rafael Martins; SOGAYAR, Mari Cleide; GRANJEIRO, Jose Mauro
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
362.82152%
Objective: Low molecular weight protein tyrosine phosphatases (LMW-PTPs) are a family of enzymes strongly involved in the regulation of cell growth and differentiation. Since there is no information concerning the relationship between osteoblastic differentiation and LMW-PTP expression/activity, we investigated its involvement during human osteoblast-like cells (hFOB 1.19) differentiation. It is known that LMW-PTP is regulated by an elegant redox mechanism, so we also observed how the osteoblastic differentiation affected the reduced glutathione levels. Design: hFOB 1.19 cells were cultured in DMEM/F12 up to 35 days. The osteoblast phenotype acquisition was monitored by measuring alkaline phosphatase activity and mineralized nodule formation by Von Kossa staining. LMW-PTP activity and expression were measured using the p-nitrophenylphosphate as substrate and Western blotting respectively. Crystal violet assay determined the cell number in each experimental point. Glutathione level was determined by both HPLC and DNTB assays. Results: LMW-PTP modulation was coincident with the osteoblastic differentiation biomarkers, such as alkaline phosphatase activity and presence of nodules of mineralization in Vitro. Likewise LMW-PTP, the reduced glutathione-dependent microenvironment was modulated during osteoblastic differentiation. During this process...

‣ Ascorbate-induced osteoblast differentiation recruits distinct MMP-inhibitors: RECK and TIMP-2

ZAMBUZZI, Willian F.; YANO, Claudia L.; CAVAGIS, Alexandre D. M.; PEPPELENBOSCH, Maikel P.; GRANJEIRO, Jose Mauro; FERREIRA, Carmen V.
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
362.82152%
The bone formation executed by osteoblasts represents an interesting research field both for basic and applied investigations. The goal of this work was to evaluate the molecular mechanisms involved during osteoblast differentiation in vitro. Accordingly, we demonstrated that, during the osteoblastic differentiation, TIMP-2 and RECK presented differential expressions, where RECK expression was downregulated from the 14th day in contrast with an increase in TIMP-2. Concomitantly, our results showed a temporal regulation of two major signaling cascades during osteoblast differentiation: proliferation cascades in which RECK, PI3 K, and GSK-3 beta play a pivotal role and latter, differentiation cascades with participation of Ras, Rho, Rac-1, PKC alpha/beta, and TIMP-2. Furthermore, we observed that phosphorylation level of paxillin was downregulated while FAK(125) remained unchangeable, but active during extracellular matrix (ECM) remodeling. Concluding, our results provide evidences that RECK and TIMP-2 are involved in the control of ECM remodeling in distinct phases of osteoblast differentiation by modulating MMP activities and a multitude of signaling proteins governs these events.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

‣ Tissue transglutaminase (TG2) activity regulates osteoblast differentiation and mineralization in the SAOS-2 cell line

Yin,Xiaoxue; Chen,Zhongqiang; Liu,Zhongjun; Song,Chunli
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2012 Português
Relevância na Pesquisa
364.91555%
Tissue transglutaminase (type II, TG2) has long been postulated to directly promote skeletal matrix calcification and play an important role in ossification. However, limited information is available on the expression, function and modulating mechanism of TG2 during osteoblast differentiation and mineralization. To address these issues, we cultured the well-established human osteosarcoma cell line SAOS-2 with osteo-inductive conditioned medium and set up three time points (culture days 4, 7, and 14) to represent different stages of SAOS-2 differentiation. Osteoblast markers, mineralization, as well as TG2 expression and activity, were then assayed in each stage. Furthermore, we inhibited TG activity with cystamine and then checked SAOS-2 differentiation and mineralization in each stage. The results showed that during the progression of osteoblast differentiation SAOS-2 cells presented significantly high levels of osteocalcin (OC) mRNA, bone morphogenetic protein-2 (BMP-2) and collagen I, significantly high alkaline phosphatase (ALP) activity, and the increased formation of calcified matrix. With the same tendency, TG2 expression and activity were up-regulated. Furthermore, inhibition of TG activity resulted in a significant decrease of OC...

‣ Serotonin regulates osteoblast proliferation and function in vitro

Dai,S.Q.; Yu,L.P.; Shi,X.; Wu,H.; Shao,P.; Yin,G.Y.; Wei,Y.Z.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2014 Português
Relevância na Pesquisa
366.49887%
The monoamine serotonin (5-hydroxytryptamine, 5-HT), a well-known neurotransmitter, also has important functions outside the central nervous system. The objective of this study was to investigate the role of 5-HT in the proliferation, differentiation, and function of osteoblasts in vitro. We treated rat primary calvarial osteoblasts with various concentrations of 5-HT (1 nM to 10 µM) and assessed the rate of osteoblast proliferation, expression levels of osteoblast-specific proteins and genes, and the ability to form mineralized nodules. Next, we detected which 5-HT receptor subtypes were expressed in rat osteoblasts at different stages of osteoblast differentiation. We found that 5-HT could inhibit osteoblast proliferation, differentiation, and mineralization at low concentrations, but this inhibitory effect was mitigated at relatively high concentrations. Six of the 5-HT receptor subtypes (5-HT1A, 5-HT1B, 5-HT1D, 5-HT2A, 5-HT2B, and 5-HT2C) were found to exist in rat osteoblasts. Of these, 5-HT2A and 5-HT1B receptors had the highest expression levels, at both early and late stages of differentiation. Our results indicated that 5-HT can regulate osteoblast proliferation and function in vitro.

‣ The effects of 6-gingerol on proliferation, differentiation, and maturation of osteoblast-like MG-63 cells

Fan,J.Z.; Yang,X.; Bi,Z.G.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 Português
Relevância na Pesquisa
364.91555%
We investigated whether 6-gingerol affects the maturation and proliferation of osteoblast-like MG63 cells in vitro. Osteoblast-like MG63 cells were treated with 6-gingerol under control conditions, and experimental inflammation was induced by tumor necrosis factor-α (TNF-α). Expression of different osteogenic markers and cytokines was analyzed by real-time PCR, Western blotting, and enzyme-linked immunosorbent assay. In addition, alkaline phosphatase (ALP) enzyme activity and biomineralization as markers for differentiation were measured. Treatment with 6-gingerol resulted in insignificant effects on the proliferation rate. 6-Gingerol induced the differentiation of osteoblast-like cells with increased transcription levels of osteogenic markers, upregulated ALP enzyme activity, and enhanced mineralized nodule formation. Stimulation with TNF-α led to enhanced interleukin-6 and nuclear factor-κB expression and downregulated markers of osteoblastic differentiation. 6-Gingerol reduced the degree of inflammation in TNF-α-treated MG-63 cells. In conclusion, 6-gingerol stimulated osteoblast differentiation in normal physiological and inflammatory settings, and therefore, 6-gingerol represents a promising agent for treating osteoporosis or bone inflammation.

‣ Osteoblast differentiation of human bone marrow cells under continuous and discontinuous treatment with dexamethasone

Beloti,Márcio Mateus; Rosa,Adalberto Luiz
Fonte: Fundação Odontológica de Ribeirão Preto Publicador: Fundação Odontológica de Ribeirão Preto
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2005 Português
Relevância na Pesquisa
364.91555%
Dexamethasone (Dex) has been shown to induce osteoblast differentiation in several cell culture systems. This study investigated the effect of continuous and discontinuous treatment with Dex on osteoblast differentiation of human bone marrow stromal cells (BMSC). Primary culture and first passage were cultured in media with or without Dex 10-7 M. During the culture period, cells were incubated at 37ºC in humidified atmosphere of 5% CO2 and 95% air. At 7, 14, and 21 days, cell proliferation, cell viability, total protein content, alkaline phosphatase (ALP) activity and bone-like formation were evaluated. Data were compared by two-way analysis of variance. Dex did not affect cell viability and total protein content, but reduced cell number. ALP activity and bone-like formation increased when only first passage or both primary culture and first passage were treated with Dex, in comparison to the groups that did not have contact with Dex after first passage. The results of this study indicate that, for human BMSC, continuous presence of Dex did not appear to be required for development of the osteoblast phenotype, but Dex must be present after first passage to allow osteoblast differentiation expressed by reduced cell proliferation and increased ALP activity and bone-like formation.

‣ Vitamin K promotes mineralization, osteoblast-to-osteocyte transition, and an anticatabolic phenotype by y-carboxylation-dependent and -independent mechanisms

Atkins, G.; Welldon, K.; Wijenayaka, A.; Bonewald, L.; Findlay, D.
Fonte: Amer Physiological Soc Publicador: Amer Physiological Soc
Tipo: Artigo de Revista Científica
Publicado em //2009 Português
Relevância na Pesquisa
359.92207%
The vitamin K family members phylloquinone (vitamin K1) and the menaquinones (vitamin K2) are under study for their roles in bone metabolism and as potential therapeutic agents for skeletal diseases. We have investigated the effects of two naturally occurring homologs, phytonadione (vitamin K1) and menatetrenone (vitamin K2), and those of the synthetic vitamin K, menadione (vitamin K3), on human primary osteoblasts. All homologs promoted in vitro mineralization by these cells. Vitamin K1-induced mineralization was highly sensitive to warfarin, whereas that induced by vitamins K2 and K3 was less sensitive, implying that -carboxylation and other mechanisms, possibly genomic actions through activation of the steroid xenobiotic receptor, are involved in the effect. The positive effect on mineralization was associated with decreased matrix synthesis, evidenced by a decrease from control in expression of type I collagen mRNA, implying a maturational effect. Incubation in the presence of vitamin K2 or K3 in a three-dimensional type I collagen gel culture system resulted in increased numbers of cells with elongated cytoplasmic processes resembling osteocytes. This effect was not warfarin sensitive. Addition of calcein to vitamin K-treated cells revealed vitamin K-dependent deposition of mineral associated with cell processes. These effects are consistent with vitamin K promoting the osteoblast-to-osteocyte transition in humans. To test whether vitamin K may also act on mature osteocytes...

‣ The effect of bone anabolic stimuli on human osteoblast to osteocyte transition.

Welldon, Katie Jane
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2012 Português
Relevância na Pesquisa
364.91555%
Osteoporosis, a condition defined by a low bone mineral density (BMD) and associated with increased fracture risk, is associated with a decrease in both osteocyte (OY) density and viability. A great deal of evidence implicates OY as central to bone physiology and pathology (1). However, human OY biology in particular is poorly characterised. We previously showed that a variety of bone-acting factors induce a pro-anabolic or pro-catabolic response in human primary osteoblasts (Normal Human Bone-derived Cells, NHBC), concomitant with the acquisition of an OY-like phenotype (2-6). Bone mineralisation, the deposition of calcium and phosphate as calcium phosphate in the form of hydroxyapatite, occurs in lamellar bone concurrent with osteoblast to OY transition (7). The first aim of the current study was to characterise the role of calcium, a common dietary supplement for the treatment of osteoporosis, in the transition of osteoblasts to OY, using human primary cell models. Secondly, low intensity pulsed ultrasound (LIPUS), an emerging therapy for osteoporosis and fracture repair, was also assessed for its effects on NHBC differentiation into OY. We hypothesised that each of these stimuli would exert a proanabolic effect on NHBC differentiation...

‣ The underlying molecular regulators and their effects on mineralisation in the trabecular bone microenvironment and osteoblast of primary hip osteoarthritis.

Kumarasinghe, Duminda Dananjaya
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2012 Português
Relevância na Pesquisa
364.91555%
Primary hip osteoarthritis (OA) is emerging as a dynamic pathology, developing over a long period and involving many tissue types of the joint, including the bone. Previous studies have established differential gene expression, changes in microarchitectural indices, altered cellular characteristics and material properties in the bone of primary hip OA. These studies suggest that OA is a systemic disease involving the bone and validate the assessment of molecular changes to further investigate this complex disease. The aim of the studies herein was to further characterise the altered gene expression profile in both OA bone and osteoblasts, and compare these with control (CTL) bone and cells, respectively. The first study examined differential gene expression, histomorphometric indices and relationships between these, in femoral trabecular bone from OA patients and CTL subjects, with the aim of identifying molecular changes consistent with structural and remodelling indices in the OA pathology. The second and third studies used primary osteoblasts derived from female hip OA cases against CTL to investigate the expression of candidate OA disease genes during osteoblast differentiation and mineralisation, in terms of calcium apposition and elemental composition of the mineral. A number of alterations in gene expression...

‣ The effects of 6-gingerol on proliferation, differentiation, and maturation of osteoblast-like MG-63 cells

Fan,J.Z.; Yang,X.; Bi,Z.G.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2015 Português
Relevância na Pesquisa
364.91555%
We investigated whether 6-gingerol affects the maturation and proliferation of osteoblast-like MG63 cells in vitro. Osteoblast-like MG63 cells were treated with 6-gingerol under control conditions, and experimental inflammation was induced by tumor necrosis factor-α (TNF-α). Expression of different osteogenic markers and cytokines was analyzed by real-time PCR, Western blotting, and enzyme-linked immunosorbent assay. In addition, alkaline phosphatase (ALP) enzyme activity and biomineralization as markers for differentiation were measured. Treatment with 6-gingerol resulted in insignificant effects on the proliferation rate. 6-Gingerol induced the differentiation of osteoblast-like cells with increased transcription levels of osteogenic markers, upregulated ALP enzyme activity, and enhanced mineralized nodule formation. Stimulation with TNF-α led to enhanced interleukin-6 and nuclear factor-κB expression and downregulated markers of osteoblastic differentiation. 6-Gingerol reduced the degree of inflammation in TNF-α-treated MG-63 cells. In conclusion, 6-gingerol stimulated osteoblast differentiation in normal physiological and inflammatory settings, and therefore, 6-gingerol represents a promising agent for treating osteoporosis or bone inflammation.

‣ Differential effects of 1,25-dihydroxyvitamin D on mineralisation and differentiation in two different types of osteoblast-like cultures

Yang, D.; Atkins, G.; Turner, A.; Anderson, P.; Morris, H.
Fonte: Pergamon-Elsevier Science Ltd Publicador: Pergamon-Elsevier Science Ltd
Tipo: Artigo de Revista Científica
Publicado em //2013 Português
Relevância na Pesquisa
362.82152%
In osteoblast cultures, 1,25-dihydroxyvitamin D (1,25D) has been shown to play either catabolic or anabolic roles on differentiation and mineralisation. We have employed osteoblast-like cells extracted from neonatal mouse calvariae and cells derived from juvenile mouse long bones to compare the biological effects of 1,25D on differentiation and mineralisation in vitro. 1,25D exerts differential effects on osteoblast-like cells depending on their stage of maturation and possibly their skeletal origin. This article is part of a Special Issue entitled 'Vitamin D Workshop'.; D. Yang, G.J. Atkins, A.G. Turner, P.H. Anderson, H.A. Morris; This article is part of a Special Issue entitled ‘Vitamin D Workshop’.

‣ Development of the osteoblast phenotype of serial cell subcultures from human bone marrow

Rosa,Adalberto Luiz; Beloti,Márcio Mateus
Fonte: Fundação Odontológica de Ribeirão Preto Publicador: Fundação Odontológica de Ribeirão Preto
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2005 Português
Relevância na Pesquisa
362.82152%
Bone marrow cells have been used for testing biocompatibility of bone substitute materials that would be applied in maxillofacial and orthopedic surgeries. However, it remains unclear whether cells in serial subcultures retain the ability to differentiate into osteoblasts. The purpose of this study was to compare the development of osteoblast phenotype of serially passaged cells from human bone marrow. Cells from first to third passage were cultured (2x10(4) cells/well) in supplemented culture medium. Cells were incubated at 37ºC in a humidified atmosphere of 5% CO2 and 95% air. Cell attachment was assessed at 4 and 24 h. At 7, 14 and 21 days, cell proliferation, cell viability, total protein content and alkaline phosphatase (ALP) activity were evaluated. Bone-like formation was evaluated at 14 and 21 days. Data were compared by two-way ANOVA and Duncan's multiple range test. Cell attachment, cell viability and total protein content were not affected by serial subcultures. However, serial subcultures did interfered negatively with osteoblast differentiation as shown by osteoblast parameters observed in second and third subcultures, such as continuous cell proliferation, lower ALP activity and bone-like formation in comparison to first subculture. Therefore...

‣ Spectroscopic Characterization of an Oxovanadium(IV) Complex of Oxodiacetic Acid and 2,2'-Bipyridine: Bioactivity on Osteoblast-Like Cells in Culture

León,Ignacio E.; Etcheverry,Susana B.; Parajón-Costa,Beatriz S.; Baran,Enrique J.
Fonte: Sociedad Química de México A.C. Publicador: Sociedad Química de México A.C.
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2013 Português
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The oxovanadium(IV) complex of oxodiacetic acid (H2ODA) and 2,2'-bipyridine (bipy) of stoichiometry [VO(ODA)(bipy)]⋅H2O, was thoroughly characterized by infrared, Raman and electronic spectroscopies. The biological activity of the complex on the cell proliferation was tested on osteoblast-like cells (MC3T3E1 osteoblastic mouse calvaria-derived cells and UMR106 rat osteosarcoma-derived cells) in culture. The complex caused inhibition of cellular proliferation in both osteoblast-like cells in culture, but its action was statistically stronger in the tumoral cells. This effect was specially marked with increasing concentrations of the complex. Based on these preliminary biological results, [VO(ODA)(bipy)]⋅H2O can be considered as a good candidate to be further investigated in relation to cancer treatment.