Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 13.959
Filtrar
1.
F1000Res ; 92020.
Artigo em Inglês | MEDLINE | ID: mdl-32953088

RESUMO

Obesity and osteoporosis are both common conditions with high rates of morbidity and mortality. There is a relationship between obesity and bone. There are multiple factors that influence the risk of fracture, including the quality of bone, the risk of falls, and the padding around the bone. These multiple factors partly explain the finding that obesity protects against fractures in some sites while increasing the risk in other parts of the body. While it is well known that increased weight builds bone, there are several mechanisms related to the obese state that make the bone more fragile. These include the increased production of bone marrow fat cells at the expense of bone-forming osteoblasts, an increase in inflammatory cytokines leading to the activation of bone-resorbing osteoclasts, mutations in the FTO gene, and obesity-induced increased osteoblast senescence. Surprisingly, the relationship between bone and obesity is not unidirectional; there is now evidence that osteocytes are able to regulate body weight by acting as weighing machines.


Assuntos
Osso e Ossos/patologia , Obesidade/fisiopatologia , Osteoblastos/citologia , Osteoclastos/citologia , Osteócitos/citologia , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Senescência Celular , Humanos
2.
PLoS Biol ; 18(8): e3000792, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32745129

RESUMO

A ubiquitous feature of the circadian clock across life forms is its organization as a network of cellular oscillators, with individual cellular oscillators within the network often exhibiting considerable heterogeneity in their intrinsic periods. The interaction of coupling and heterogeneity in circadian clock networks is hypothesized to influence clock's entrainability, but our knowledge of mechanisms governing period heterogeneity within circadian clock networks remains largely elusive. In this study, we aimed to explore the principles that underlie intercellular period variation in circadian clock networks (clonal period heterogeneity). To this end, we employed a laboratory selection approach and derived a panel of 25 clonal cell populations exhibiting circadian periods ranging from 22 to 28 h. We report that a single parent clone can produce progeny clones with a wide distribution of circadian periods, and this heterogeneity, in addition to being stochastically driven, has a heritable component. By quantifying the expression of 20 circadian clock and clock-associated genes across our clone panel, we found that inheritance of expression patterns in at least three clock genes might govern clonal period heterogeneity in circadian clock networks. Furthermore, we provide evidence suggesting that heritable epigenetic variation in gene expression regulation might underlie period heterogeneity.


Assuntos
Proteínas CLOCK/genética , Relógios Circadianos/genética , Ritmo Circadiano/genética , Epigênese Genética , Redes Reguladoras de Genes , Animais , Proteínas CLOCK/metabolismo , Linhagem Celular Tumoral , Células Clonais , Perfilação da Expressão Gênica , Genes Reporter , Heterogeneidade Genética , Humanos , Padrões de Herança , Luciferases/genética , Luciferases/metabolismo , Camundongos , Células NIH 3T3 , Osteoblastos/citologia , Osteoblastos/metabolismo , Processos Estocásticos
3.
Life Sci ; 258: 118195, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32781073

RESUMO

AIMS: The estrogen-ERα axis participates in osteoblast maturation. This study was designed to further evaluated the roles of the estrogen-ERα axis in bone healing and the possible mechanisms. MAIN METHODS: Female ICR mice were created a metaphyseal bone defect in the left femurs and administered with methylpiperidinopyrazole (MPP), an inhibitor of ERα. Bone healing was evaluated using micro-computed tomography. Colocalization of ERα with alkaline phosphatase (ALP) and ERα translocation to mitochondria were determined. Levels of ERα, ERß, PECAM-1, VEGF, and ß-actin were immunodetected. Expression of chromosomal Runx2, ALP, and osteocalcin mRNAs and mitochondrial cytochrome c oxidase (COX) I and COXII mRNAs were quantified. Angiogenesis was measured with immunohistochemistry. KEY FINDINGS: Following surgery, the bone mass was time-dependently augmented in the bone-defect area. Simultaneously, levels of ERα were specifically upregulated and positively correlated with bone healing. Administration of MPP to mice consistently decreased levels of ERα and bone healing. As to the mechanisms, osteogenesis was enhanced in bone healing, but MPP attenuated osteoblast maturation. In parallel, expressions of osteogenesis-related ALP, Runx2, and osteocalcin mRNAs were induced in the injured zone. Treatment with MPP led to significant inhibition of the alp, runx2, and osteocalcin gene expressions. Remarkably, administration of MPP lessened translocation of ERα to mitochondria and expressions of mitochondrial energy production-related coxI and coxII genes. Furthermore, exposure to MPP decreased levels of PECAM-1 and VEGF in the bone-defect area. SIGNIFICANCE: The present study showed the contributions of the estrogen-ERα axis to bone healing through stimulation of energy production, osteoblast maturation, and angiogenesis.


Assuntos
Regeneração Óssea , Diferenciação Celular , Metabolismo Energético , Receptor alfa de Estrogênio/metabolismo , Neovascularização Fisiológica , Osteoblastos/citologia , Transdução de Sinais , Fosfatase Alcalina/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Regeneração Óssea/efeitos dos fármacos , Calo Ósseo/efeitos dos fármacos , Calo Ósseo/patologia , Diferenciação Celular/efeitos dos fármacos , Cromossomos de Mamíferos/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Metabolismo Energético/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Camundongos Endogâmicos ICR , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Neovascularização Fisiológica/efeitos dos fármacos , Tamanho do Órgão/efeitos dos fármacos , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteocalcina/metabolismo , Osteogênese/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Pirazóis/administração & dosagem , Pirazóis/farmacologia , Regulação para Cima/efeitos dos fármacos , Cicatrização/efeitos dos fármacos
4.
Int J Nanomedicine ; 15: 4705-4716, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32636626

RESUMO

Purpose: Ultra-small gold nanoclusters (AuNCs), as emerging fluorescent nanomaterials with excellent biocompatibility, have been widely investigated for in vivo biomedical applications. However, their effects in guiding osteogenic differentiation have not been investigated, which are important for osteoporosis therapy and bone regeneration. Herein, for the first time, lysozyme-protected AuNCs (Lys-AuNCs) are used to stimulate osteogenic differentiation, which have the potential for the treatment of bone disease. Methods: Proliferation of MC3T3E-1 is important for osteogenic differentiation. First, the proliferation rate of MC3T3E-1 was studied by Cell Counting Kit-8 (CCK8) assays. Signaling pathways of PI3K/Akt play central roles in controlling proliferation throughout the body. The expression of PI3K/Akt was investigated in the presence of lysozyme, and lysozyme-protected AuNCs (Lys-AuNCs) by Western blot (WB) and intracellular cell imaging to evacuate the osteogenic differentiation mechanisms. Moreover, the formation of osteoclasts (OC) plays a negative role in the differentiation of osteoblasts. Nuclear factor κB ligand (RANKL) and macrophage colony-stimulating factor (M-CSF) signaling pathways are used to understand the negative influence of the osteogenic differentiation by the investigation of Raw 264.7 cell line. Raw 264.7 (murine macrophage-like) cells and NIH/3T3 (mouse fibroblast) cells were treated with tyloxapol, and the cell viability was assessed. Raw 264.7 cells have also been used for in vitro studies, on understanding the osteoclast formation and function. The induced osteoclasts were identified by TRAP confocal fluorescence imaging. These key factors in osteoclast formation, such as (NFATc-1, c-Fos, V-ATPase-2 and CTSK), were investigated by Western blot. Results: Based on the above investigation, Lys-AuNCs were found to promote osteogenic differentiation and decrease osteoclast activity. It is noteworthy that the lysozyme (protected template), AuNPs, or the mixture of Lysozyme and AuNPs have negligible effects on osteoblastic differentiation compared to Lys-AuNCs. Conclusion: This study opens up a novel avenue to develop a new gold nanomaterial for promoting osteogenic differentiation. The possibility of using AuNCs as nanomedicines for the treatment of osteoporosis can be expected.


Assuntos
Nanopartículas Metálicas/química , Osteoclastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Animais , Diferenciação Celular/efeitos dos fármacos , Ouro/farmacologia , Nanopartículas Metálicas/administração & dosagem , Camundongos , Muramidase/química , Muramidase/metabolismo , Fatores de Transcrição NFATC/metabolismo , Nanomedicina/métodos , Osteoblastos/citologia , Osteoclastos/citologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Células RAW 264.7
5.
Int J Nanomedicine ; 15: 4171-4189, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606671

RESUMO

Background: Angiogenic and osteogenic activities are two major problems with biomedical titanium (Ti) and other orthopedic implants used to repair large bone defects. Purpose: The aim of this study is to prepare hydroxyapatite (HA) coatings on the surface of Ti by using electrochemical deposition (ED), and to evaluate the effects of nanotopography and silicon (Si) doping on the angiogenic and osteogenic activities of the coating in vitro. Materials and Methods: HA coating and Si-doped HA (HS) coatings with varying nanotopographies were fabricated using two ED modes, ie, the pulsive current (PC) and cyclic voltammetry (CV) methods. The coatings were characterized through scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectrometer (XPS), and atomic force microscopy (AFM), and their in vitro bioactivity and protein adsorption were assessed. Using MC3T3-E1 pre-osteoblasts and HUVECs as cell models, the osteogenic and angiogenic capabilities of the coatings were evaluated through in vitro cellular experiments. Results: By controlling Si content in ~0.8 wt.%, the coatings resulting from the PC mode (HA-PC and HS-PC) and CV mode (HA-CV and HS-CV) had nanosheet and nanorod topographies, respectively. At lower crystallinity, higher ionic dissolution, smaller contact angle, higher surface roughness, and more negative zeta potential, the HS and PC samples exhibited quicker apatite deposition and higher BSA adsorption capacity. The in vitro cell study showed that Si doping was more favorable for enhancing the viability of the MC3T3-E1 cells, but nanosheet coating increased the area for cell spreading. Of the four coatings, HS-PC with Si doping and nanosheet topography exhibited the best effect in terms of up-regulating the expressions of the osteogenic genes (ALP, Col-I, OSX, OPN and OCN) in the MC3T3-E1 cells. Moreover, all leach liquors of the surface-coated Ti disks promoted the growth of the HUVECs, and the HS samples played a more significant role in promoting cell migration and tube formation than the HA samples. Of the four leach liquors, only the two HS samples up-regulated NO content and expressions of the angiogenesis-related genes (VEGF, bFGF and eNOS) in the HUVECs, and the HS-PC yielded a better effect. Conclusion: The results show that Si doping while regulating the topography of the coating can help enhance the bone regeneration and vascularization of HA-coated Ti implants.


Assuntos
Materiais Revestidos Biocompatíveis/farmacologia , Durapatita/farmacologia , Nanopartículas/química , Osteogênese , Próteses e Implantes , Silício/química , Titânio/farmacologia , Adsorção , Animais , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Camundongos , Nanopartículas/ultraestrutura , Nanotubos/química , Neovascularização Fisiológica/efeitos dos fármacos , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Soroalbumina Bovina/química , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Difração de Raios X
6.
Int J Nanomedicine ; 15: 4471-4481, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606689

RESUMO

Background: Ineffective integration has been recognized as one of the major causes of early orthopedic failure of titanium-based implants. One strategy to address this problem is to develop modified titanium surfaces that promote osteoblast differentiation. This study explored titanium surfaces modified with TiO2 nanotubes (TiO2 NTs) capable of localized drug delivery into bone and enhanced osteoblast cell differentiation. Materials and Methods: Briefly, TiO2 NTs were subjected to anodic oxidation and loaded with Metformin, a widely used diabetes drug. To create surfaces with sustainable drug-eluting characteristics, TiO2 NTs were spin coated with a thin layer of chitosan. The surfaces were characterized via scanning electron microscopy, atomic force microscopy, and contact angle measurements. The surfaces were then exposed to mesenchymal bone marrow stem cells (MSCs) to evaluate cell adhesion, growth, differentiation, and morphology on the modified surfaces. Results: A noticeable increase in drug release time (3 days vs 20 days) and a decrease in burst release characteristics (85% to 7%) was observed in coated samples as compared to uncoated samples, respectively. Chitosan-coated TiO2 NTs exhibited a considerable enhancement in cell adhesion, proliferation, and genetic expression of type I collagen, and alkaline phosphatase activity as compared to uncoated TiO2 NTs. Conclusion: TiO2 NT surfaces with a chitosan coating are capable of delivering Metformin to a bone site over a sustained period of time with the potential to enhance MSCs cell attachment, proliferation, and differentiation.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Quitosana/química , Liberação Controlada de Fármacos , Metformina/farmacologia , Nanotubos/química , Osteoblastos/citologia , Titânio/química , Fosfatase Alcalina/metabolismo , Animais , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Nanotubos/ultraestrutura , Osteoblastos/efeitos dos fármacos , Osteoblastos/ultraestrutura , Osteogênese/efeitos dos fármacos , Ratos Wistar , Molhabilidade
7.
Proc Natl Acad Sci U S A ; 117(32): 19276-19286, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32719141

RESUMO

Bone homeostasis requires continuous remodeling of bone matrix to maintain structural integrity. This involves extensive communication between bone-forming osteoblasts and bone-resorbing osteoclasts to orchestrate balanced progenitor cell recruitment and activation. Only a few mediators controlling progenitor activation are known to date and have been targeted for intervention of bone disorders such as osteoporosis. To identify druggable pathways, we generated a medaka (Oryzias latipes) osteoporosis model, where inducible expression of receptor-activator of nuclear factor kappa-Β ligand (Rankl) leads to ectopic formation of osteoclasts and excessive bone resorption, which can be assessed by live imaging. Here we show that upon Rankl induction, osteoblast progenitors up-regulate expression of the chemokine ligand Cxcl9l. Ectopic expression of Cxcl9l recruits mpeg1-positive macrophages to bone matrix and triggers their differentiation into osteoclasts. We also demonstrate that the chemokine receptor Cxcr3.2 is expressed in a distinct subset of macrophages in the aorta-gonad-mesonephros (AGM). Live imaging revealed that upon Rankl induction, Cxcr3.2-positive macrophages get activated, migrate to bone matrix, and differentiate into osteoclasts. Importantly, mutations in cxcr3.2 prevent macrophage recruitment and osteoclast differentiation. Furthermore, Cxcr3.2 inhibition by the chemical antagonists AMG487 and NBI-74330 also reduced osteoclast recruitment and protected bone integrity against osteoporotic insult. Our data identify a mechanism for progenitor recruitment to bone resorption sites and Cxcl9l and Cxcr3.2 as potential druggable regulators of bone homeostasis and osteoporosis.


Assuntos
Matriz Óssea/metabolismo , Quimiocina CXCL9/metabolismo , Proteínas de Peixes/metabolismo , Oryzias/metabolismo , Osteoclastos/metabolismo , Osteoporose/metabolismo , Receptores CXCR3/metabolismo , Células-Tronco/metabolismo , Animais , Matriz Óssea/crescimento & desenvolvimento , Diferenciação Celular , Quimiocina CXCL9/genética , Modelos Animais de Doenças , Proteínas de Peixes/genética , Humanos , Macrófagos/metabolismo , Oryzias/genética , Oryzias/crescimento & desenvolvimento , Osteoblastos/citologia , Osteoblastos/metabolismo , Osteoclastos/citologia , Osteoporose/genética , Osteoporose/fisiopatologia , Ligação Proteica , Receptores CXCR3/genética , Células-Tronco/citologia
8.
Gene ; 757: 144852, 2020 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-32599019

RESUMO

Until now, various methods have been introduced to fabricate 3D scaffolds to provide a suitable substrate for cell growth and proliferation and subsequent use in tissue engineering to repair damaged tissues. The 3D scaffolds can simulate the natural cellular microenvironment well. Herein, the decellularized leaf spinach has been used which not only have no problems associated with artificial scaffolds, but they also do not cost significantly. Decellularized scaffolds surface properties were characterized by the investigation of scaffolds surface roughness, hydrophilicity, mechanical properties, size and shape of porosities and specific surface area. In the next step, osteogenic differentiation potential of bone marrow derived mesenchymal stem cells cultured on the scaffold and culture plate (as a control) was evaluated using alizarin staining and calcium content, alkaline phosphatase activity and bone related genes expression assays. The results indicated that the surface properties and shape of scaffold pores were effective in the stem cells binding, growth and proliferation. This higher biocompatibility due to the ideal surface hydrophilicity as well as high specific surface area due to the presence of a rough grid surface ultimately increased the efficiency of stem cell's bone differentiation. Taken together, it can be concluded that the decellularized spinach leaf scaffold, due to its easy availability, low prices and high efficiency, can be considered as a promising potential candidate for use as a proper substrate for stem cell growth and differentiation in bone tissue engineering.


Assuntos
Diferenciação Celular , Células-Tronco Mesenquimais/metabolismo , Osteoblastos/metabolismo , Osteocalcina/genética , Folhas de Planta/química , Tecidos Suporte/química , Fosfatase Alcalina/genética , Fosfatase Alcalina/metabolismo , Biomineralização , Cálcio/metabolismo , Linhagem Celular , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Humanos , Células-Tronco Mesenquimais/citologia , Osteoblastos/citologia , Osteocalcina/metabolismo , Spinacia oleracea/química
9.
Life Sci ; 256: 117964, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32534036

RESUMO

AIMS: Vascular smooth muscle cells (VSMCs) are important regulators of vascular functions and their conversion to osteoblasts is a key to development of vascular calcification. This study aimed to characterize in vitro effect of hepatoma-derived growth factor (HDGF) on phenotypic conversion of cultured aortic VSMCs into osteoblast-like cells. MATERIALS AND METHODS: Cell proliferation and migration assays were used to examine cell behaviors. Western blotting, alkaline phosphatase activity and calcium staining were used to evaluate osteoblastic marker expression and function, respectively. KEY FINDINGS: Recombinant HDGF treatment enhanced VSMC growth and motility. Treatment of osteogenic medium (OM) increased expression of not only HDGF but also osteoblastic markers, including Runx2 and osteopontin (OPN), while VSMC marker α-smooth muscle actin (α-SMA) declined. Coincidentally, HDGF and OM treatment alone stimulated signaling activities in both PI3K/Akt and MAPK pathways. Conversely, inhibition of Akt and p38 significantly blocked the OM-upregulated HDGF, Runx2, and OPN expression and NF-κB phosphorylation, but did not reversed the α-SMA downregulation, implicating the involvement of Akt and p38 activities in the osteoblastic transformation of VSMCs. Small interfering RNA-mediated HDGF gene silencing effectively prevented the Runx2 and OPN upregulation, alkaline phosphatase activation, and calcium deposition, but did not affect the α-SMA levels in the transformed cells, supporting the involvement of HDGF in regulation of Runx2 and OPN expression. SIGNIFICANCE: In conclusion, in synergism with other osteogenic factor, HDGF may promote the progression of osteobastic transformation of VSMCs via Akt and p38 signaling pathways and contribute to vascular calcification in arteriosclerosis. CHEMICAL COMPOUNDS STUDIED IN THIS STUDY: HDGF (PubChem CID:); LY294002 (PubChem CID: 3973); PD98059 (PubChem CID: 4713); SB203580 (PubChem CID: 176155); SB431542 (PubChem CID: 4521392); SP600125 (PubChem CID: 8515); Wortmannin (PubChem CID: 312145).


Assuntos
Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/citologia , Osteoblastos/citologia , Animais , Biomarcadores/metabolismo , Linhagem Celular Transformada , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Inativação Gênica/efeitos dos fármacos , Cinética , Miócitos de Músculo Liso/efeitos dos fármacos , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteogênese/efeitos dos fármacos , Osteopontina/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos Sprague-Dawley , Regulação para Cima/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
10.
PLoS Genet ; 16(6): e1008805, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32497039

RESUMO

Osteoporosis is a genetic disease characterized by progressive reductions in bone mineral density (BMD) leading to an increased risk of fracture. Over the last decade, genome-wide association studies (GWASs) have identified over 1000 associations for BMD. However, as a phenotype BMD is challenging as bone is a multicellular tissue affected by both local and systemic physiology. Here, we focused on a single component of BMD, osteoblast-mediated bone formation in mice, and identified associations influencing osteoblast activity on mouse Chromosomes (Chrs) 1, 4, and 17. The locus on Chr. 4 was in an intergenic region between Wnt4 and Zbtb40, homologous to a locus for BMD in humans. We tested both Wnt4 and Zbtb40 for a role in osteoblast activity and BMD. Knockdown of Zbtb40, but not Wnt4, in osteoblasts drastically reduced mineralization. Additionally, loss-of-function mouse models for both genes exhibited reduced BMD. Our results highlight that investigating the genetic basis of in vitro osteoblast mineralization can be used to identify genes impacting bone formation and BMD.


Assuntos
Densidade Óssea/genética , Osteoblastos/metabolismo , Animais , Células Cultivadas , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Osteoblastos/citologia , Osteogênese/genética , Proteína Wnt4/genética
11.
J Biol Regul Homeost Agents ; 34(2): 345-355, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32548991

RESUMO

Osteoporosis is defined as an aging-related skeletal disorder involving deterioration of bone mass and bone structure, and consequently, increased risk of fractures. Emerging evidence indicates the dysregulation of microRNAs (miRNAs) in the progression of osteoporosis. However, whether such associated miRNAs control osteoblast differentiation or constitute therapeutic targets remains elusive. In the present study, we found elevated circulating miR-374b-5p level associated with postmenopausal osteoporosis. miR-374b-5p served as a critical suppressor of osteoblast differentiation. We further identified that miR-374b-5p directly targeted Wnt family member 3 (Wnt3) and Runt-related transcription factor 2 (Runx2) through its 3'-untranslated regions (3'UTRs). Moreover, the antagonist of miR-374b-5p could promote bone formation in ovariectomy (OVX)-induced mice. Together, our results revealed that miR-374b-5p directly targeted Wnt3 and Runx2, negatively regulating osteoblast differentiation and bone formation. Collectively, circulating miR-374b-5p in the serum might serve as a potential diagnostic and therapeutic strategy for osteoporosis.


Assuntos
Diferenciação Celular , Subunidade alfa 1 de Fator de Ligação ao Core/genética , MicroRNAs/sangue , Osteoblastos/citologia , Osteoporose/genética , Proteína Wnt3/genética , Animais , Células Cultivadas , Feminino , Humanos , Camundongos , Osteogênese
12.
Arch Biochem Biophys ; 690: 108416, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32502471

RESUMO

Alkaptonuria (AKU) is a rare metabolic disease correlated with the deficiency of homogentisate 1,2-dioxygenase and leading to an accumulation of the metabolite homogentisic acid (HGA) which can be subjected to oxidation and polymerization reactions. These events are considered a trigger for the induction of oxidative stress in AKU but, despite the large description of an altered redox status, the underlying pathogenetic processes are still unstudied. In the present study, we investigated the molecular mechanisms responsible for the oxidative damage present in an osteoblast-based cellular model of AKU. Bone, in fact, is largely affected in AKU patients: severe osteoclastic resorption, osteoporosis, even for pediatric cases, and an altered rate of remodeling biomarkers have been reported. In our AKU osteoblast cell model, we found a clear altered redox homeostasis, determined by elevated hydrogen peroxide (H2O2) levels and 4HNE protein adducts formation. These findings were correlated with increased NADPH oxidase (NOX) activity and altered mitochondrial respiration. In addition, we observed a decreased activity of superoxide dismutase (SOD) and reduced levels of thioredoxin (TRX) that parallel the decreased Nrf2-DNA binding. Overall, our results reveal that HGA is able to alter the cellular redox homeostasis by modulating the endogenous ROS production via NOX activation and mitochondrial dysfunctions and impair the cellular response mechanism. These findings can be useful for understanding the pathophysiology of AKU, not yet well studied in bones, but which is an important source of comorbidities that affect the life quality of the patients.


Assuntos
Alcaptonúria/metabolismo , Homeostase/fisiologia , Linhagem Celular , Proteínas de Ligação a DNA/metabolismo , Ácido Homogentísico/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , NADPH Oxidases/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Osteoblastos/citologia , Oxirredução , Estresse Oxidativo/fisiologia , Transdução de Sinais , Superóxido Dismutase/metabolismo , Tiorredoxinas/metabolismo
13.
J Vis Exp ; (159)2020 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-32510503

RESUMO

Bone remodeling is a tightly regulated process that is required for skeletal growth and repair as well as adapting to changes in the mechanical environment. During this process, mechanosensitive osteocytes regulate the opposing responses between the catabolic osteoclasts and anabolic osteoblasts. To better understand the highly intricate signaling pathways that regulate this process, our lab has developed a foundationary lab-on-a-chip (LOC) platform for analyzing functional outcomes (formation and resorption) of bone remodeling within a small scale system. As bone remodeling is a lengthy process that occurs on the order of weeks to months, we developed long-term cell culturing protocols within the system. Osteoblasts and osteoclasts were grown on functional activity substrates within the LOC and maintained for up to seven weeks. Afterward, chips were disassembled to allow for the quantification of bone formation and resorption. Additionally, we have designed a 3D printed mechanical loading device that pairs with the LOC platform and can be used to induce osteocyte mechanotransduction by deforming the cellular matrix. We have optimized cell culturing protocols for osteocytes, osteoblasts, and osteoclasts within the LOC platform and have addressed concerns of sterility and cytotoxicity. Here, we present the protocols for fabricating and sterilizing the LOC, seeding cells on functional substrates, inducing mechanical load, and disassembling the LOC to quantify endpoint results. We believe that these techniques lay the groundwork for developing a true organ-on-a-chip for bone remodeling.


Assuntos
Remodelação Óssea , Dispositivos Lab-On-A-Chip , Mecanotransdução Celular , Osteócitos/citologia , Animais , Humanos , Osteoblastos/citologia , Osteoclastos/citologia , Osteogênese
14.
Phytomedicine ; 71: 153225, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32464299

RESUMO

BACKGROUND: Impaired bone formation is one of the reasons behind osteoporosis. Alterations in the patterns of mesenchymal stromal cell differentiation towards adipocytes instead of osteoblasts contribute to osteoporosis progression. Natural anti-osteoporotic agents are effective and safe alternatives for osteoporosis treatment. PURPOSE: In this context, 3,5-dicaffeoyl­epi-quinic acid (DCEQA) which is a derivative of chlorogenic acid with reported bioactivities was studied for its osteogenic differentiation enhancing potential in vitro. METHODS: Anti-osteoporotic effects of DCEQA were investigated in human bone marrow-derived mesenchymal stromal cells (hBM-MSCs) which were induced to differentiate into osteoblasts or adipocytes with or without DCEQA treatment. Changes in the osteogenic and adipogenic markers such as ALP activity and lipid accumulation, respectively, were observed along with differentiation-specific activation of mitogen activated protein kinase (MAPK) pathways. RESULTS: At 10 µM concentration, DCEQA increased the proliferation of bone marrow-derived human mesenchymal stromal cells (hBM-MSCs) during osteoblast differentiation. The expression of osteogenic markers ALP, osteocalcin, Runx2, BMP2 and Wnt 10a was upregulated by DCEQA treatment. The ALP activity and extracellular mineralization were also increased. DCEQA elevated the phosphorylation levels of p38 and JNK MAPKs as well as the activation of ß-catenin and Smad1/5. DCEQA suppressed the lipid accumulation and downregulated expression of adipogenic markers PPARγ, C/EBPα and SREBP1c in adipo-induced hBM-MSCs. DCEQA also decreased the phosphorylation of p38 and ERK MAPKs and stimulated the activation of AMPK in hBM-MSC adipocytes. CONCLUSION: DCEQA was suggested to enhance osteoblast differentiation via stimulating Wnt/BMP signaling. The adipocyte differentiation inhibitory effect of DCEQA was suggested to arise from its ability to increase AMPK phosphorylation. Overall, DCEQA was shown to possess osteogenesis enhancing and adipogenesis inhibitory properties which might facilitate its use against osteoporotic conditions.


Assuntos
Adipócitos/citologia , Atriplex/química , Ácido Clorogênico/análogos & derivados , Células-Tronco Mesenquimais/efeitos dos fármacos , Osteoblastos/efeitos dos fármacos , Proteínas Quinases Ativadas por AMP/metabolismo , Adipócitos/efeitos dos fármacos , Células da Medula Óssea , Proteína Morfogenética Óssea 2/metabolismo , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Ácido Clorogênico/farmacologia , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Humanos , Células-Tronco Mesenquimais/citologia , Osteoblastos/citologia , Osteoblastos/metabolismo , Osteogênese/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Via de Sinalização Wnt/efeitos dos fármacos , beta Catenina/metabolismo
15.
PLoS One ; 15(5): e0234009, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32470038

RESUMO

One of the potential contributing factors for iron overload-induced osteoporosis is the iron toxicity on bone forming cells, osteoblasts. In this study, the comparative effects of Fe3+ and Fe2+ on osteoblast differentiation and mineralization were studied in UMR-106 osteoblast cells by using ferric ammonium citrate and ferrous ammonium sulfate as Fe3+ and Fe2+ donors, respectively. Effects of 1,25 dihydroxyvitamin D3 [1,25(OH)2D3] and iron chelator deferiprone on iron uptake ability of osteoblasts were examined, and the potential protective ability of 1,25(OH)2D3, deferiprone and extracellular calcium treatment in osteoblast cell survival under iron overload was also elucidated. The differential effects of Fe3+ and Fe2+ on reactive oxygen species (ROS) production in osteoblasts were also compared. Our results showed that both iron species suppressed alkaline phosphatase gene expression and mineralization with the stronger effects from Fe3+ than Fe2+. 1,25(OH)2D3 significantly increased the intracellular iron but minimally affected osteoblast cell survival under iron overload. Deferiprone markedly decreased intracellular iron in osteoblasts, but it could not recover iron-induced osteoblast cell death. Interestingly, extracellular calcium was able to rescue osteoblasts from iron-induced osteoblast cell death. Additionally, both iron species could induce ROS production and G0/G1 cell cycle arrest in osteoblasts with the stronger effects from Fe3+. In conclusions, Fe3+ and Fe2+ differentially compromised the osteoblast functions and viability, which can be alleviated by an increase in extracellular ionized calcium, but not 1,25(OH)2D3 or iron chelator deferiprone. This study has provided the invaluable information for therapeutic design targeting specific iron specie(s) in iron overload-induced osteoporosis. Moreover, an increase in extracellular calcium could be beneficial for this group of patients.


Assuntos
Calcitriol/farmacologia , Deferiprona/farmacologia , Espaço Extracelular/química , Sobrecarga de Ferro/metabolismo , Ferro/farmacologia , Osteoblastos/citologia , Animais , Biomarcadores/metabolismo , Calcificação Fisiológica/efeitos dos fármacos , Cálcio/metabolismo , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Osteoblastos/efeitos dos fármacos , Ratos , Espécies Reativas de Oxigênio/metabolismo
16.
Life Sci ; 255: 117827, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32450170

RESUMO

AIMS: Data suggest pharmacological treatment of depression with selective serotonin reuptake inhibitors (SSRI) may impair bone health. Our group has previously modeled compromised craniofacial healing after treatment with sertraline, a commonly prescribed SSRI, and hypothesized potential culprits: alterations in bone cells, collagen, and/or inflammation. Here we interrogate bone lineage cell alterations due to sertraline treatment as a potential cause of the noted compromised bone healing. MAIN METHODS: Murine pre-osteoblast, pre-osteoclast, osteoblast, and osteoclast cells were treated with clinically relevant concentrations of the SSRI. Studies focused on serotonin pathway targets, cell viability, apoptosis, differentiation, and the osteoblast/osteoclast feedback loop. KEY FINDINGS: All cells studied express neurotransmitters (e.g. serotonin transporter, SLC6A4, SSRI target) and G-protein-coupled receptors associated with the serotonin pathway. Osteoclasts presented the greatest native expression of Slc6a4 with all cell types exhibiting decreases in Slc6a4 expression after SSRI treatment. Pre-osteoclasts exhibited alteration to their differentiation pathway after treatment. Pre-osteoblasts and osteoclasts showed reduced apoptosis after treatment but showed no significant differences in functional assays. RANKL: OPG mRNA and protein ratios were decreased in the osteoblast lineage. Osteoclast lineage cells treated with sertraline demonstrated diminished TRAP positive cells when pre-exposed to sertraline prior to RANKL-induced differentiation. SIGNIFICANCE: These data suggest osteoclasts are a likely target of bone homeostasis disruption due to sertraline treatment, most potently through the osteoblast/clast feedback loop.


Assuntos
Osso e Ossos/efeitos dos fármacos , Osteoblastos/efeitos dos fármacos , Osteoclastos/efeitos dos fármacos , Inibidores de Captação de Serotonina/toxicidade , Células 3T3 , Animais , Apoptose/efeitos dos fármacos , Osso e Ossos/citologia , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Camundongos , Osteoblastos/citologia , Osteoclastos/citologia , Ligante RANK/metabolismo , Células RAW 264.7 , RNA Mensageiro/metabolismo
17.
J Bone Miner Metab ; 38(5): 670-677, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32415375

RESUMO

INTRODUCTION: The periosteum has a bilayered structure that surrounds cortical bone. The outer layer is rich in connective tissue and fibroblasts, while the inner layer in contact with the cortical surface of the bone predominantly consists of osteoblasts and osteoblast progenitors. The identification of cell-specific surface markers of the bilayered structure of the periosteum is important for the purpose of tissue regeneration. MATERIALS AND METHODS: We investigated the expression of the discoidin domain tyrosine kinase receptor DDR2, fibroblast specific protein-1 (FSP-1) and alkaline phosphatase (ALP) in the periosteum of cortical bone by immunohistochemistry. Osteogenic differentiation was compared between DDR2- and FSP-1-expressing cells flow-sorted from the periosteum. RESULTS: We showed that DDR2 predominantly labeled osteogenic cells residing in the inner layer of the periosteum and that Pearson's coefficient of colocalization indicated a significant correlation with the expression of ALP. The mineralization of DDR2-expressing osteogenic cells isolated from the periosteum was significantly induced. In contrast, FSP-1 predominantly labeled the outer layer of periosteal fibroblasts, and Pearson's coefficient of colocalization indicated that FSP-1 was poorly correlated with the expression of DDR2 and ALP. FSP-1-expressing periosteal fibroblasts did not exhibit osteogenic differentiation for the induction of bone mineralization. CONCLUSION: DDR2 is a novel potential cell surface marker for identifying and isolating osteoblasts and osteoblast progenitors within the periosteum that can be used for musculoskeletal regenerative therapies.


Assuntos
Receptores com Domínio Discoidina/metabolismo , Osteoblastos/citologia , Osteoblastos/metabolismo , Periósteo/citologia , Fosfatase Alcalina/metabolismo , Animais , Biomarcadores/metabolismo , Calcificação Fisiológica , Diferenciação Celular , Camundongos Endogâmicos C57BL , Osteogênese , Proteína A4 de Ligação a Cálcio da Família S100/metabolismo
18.
Chem Biol Interact ; 329: 109112, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32360284

RESUMO

Till now monocrotophos (MCP) has been addressed as a neurotoxic stressor. Limited studies investigate its aftermath on bone pathologies. Given the fact that MCP is a propensely used insecticide in developing countries, this study investigates its potential to mirror osteoporotic features and bone loss incurred in a rodent model. Briefly, Swiss albino mice were orally gavaged daily with varying doses of MCP for 8 weeks. Musculoskeletal changes were analyzed through micro-computed tomography and histology. A series of in vitro and ex vivo cell culture experiments were performed on MC3T3E-1 and primary osteoclast cultures. Results highlight that oral gavaging with MCP causes bone loss from the cortico-trabecular interface by decreasing the osteoblast and increasing the osteoclast number. Results from in vitro studies establish that MCP treatment increases the TRAP-positive multinucleated cell number during osteoclast differentiation. Ex-vivo experiments with MCP-treated animal sera further substantiate the in vivo claims with significant decreases seen in cell viability, proliferation, mineralization and differentiation studies. In conclusion MCP induces osteoclastogenesis (bone loss) on direct stimulation and alters the circulating factors in MCP-treated serum. Holistically, this work would be of potential significance to patients suffering from pesticide induced osteoporosis.


Assuntos
Osso Esponjoso/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Osso Cortical/efeitos dos fármacos , Inseticidas/toxicidade , Monocrotofós/toxicidade , Osteogênese/efeitos dos fármacos , Animais , Osso Esponjoso/diagnóstico por imagem , Osso Esponjoso/fisiologia , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Osso Cortical/diagnóstico por imagem , Osso Cortical/fisiologia , Masculino , Camundongos , Osteoblastos/citologia , Osteoblastos/metabolismo , Microtomografia por Raio-X
19.
Gene ; 748: 144668, 2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-32334025

RESUMO

KMN-159 is the lead compound from a series of novel difluorolactam prostanoid EP4 receptor agonists aimed at inducing local bone formation while avoiding the inherent side effects of systemic EP4 activation. KMN-159 is a potent, selective small molecule possessing pharmacokinetic properties amenable to local administration. Unfractionated rat bone marrow cells (BMCs) were treated once at plating with escalating doses of KMN-159 (1 pM to 10 µM). The resulting elevated alkaline phosphatase (ALP) levels measured 9 days post-dose are consistent with increased osteoblastic differentiation and exposure to KMN-159 at low nanomolar concentrations for as little as 30 min was sufficient to induce complete osteoblast differentiation of the BMCs from both sexes and regardless of age. ALP induction was blocked by an EP4 receptor antagonist but not by EP1 or EP2 receptor antagonists and was not induced by EP2 or EP3 receptor agonists. Addition of BMCs to plates coated with KMN-159 24 days earlier resulted in ALP activation, highlighting the chemical stability of the compound. The expression of phenotype markers such as ALP, type I collagen, and osteocalcin was significantly elevated throughout the osteoblastic differentiation timecourse initiated by KMN-159 stimulation. An increased number of tartrate-resistant acid phosphatase-positive cells was observed KMN-159 or PGE2 treated BMCs but only in the presence of exogenous receptor activator of nuclear factor kappa-Β ligand (RANKL). No change in the number of adipocytes was observed. KMN-159 also increased bone healing in a rat calvarial defect model with a healing rate equivalent to recombinant human bone morphogenetic protein-2. Our studies show that KMN-159 is able to stimulate osteoblastic differentiation with a very short time of exposure, supporting its potential as a therapeutic candidate for augmenting bone mass.


Assuntos
Células da Medula Óssea/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Ácidos Heptanoicos/farmacologia , Osteoblastos/efeitos dos fármacos , Pirrolidinas/farmacologia , Receptores de Prostaglandina E Subtipo EP4/agonistas , Fosfatase Alcalina/metabolismo , Animais , Ativação Enzimática , Feminino , Células HEK293 , Humanos , Osteoblastos/citologia , Osteoblastos/enzimologia , Ratos , Ratos Sprague-Dawley
20.
J Biol Regul Homeost Agents ; 34(1 Suppl. 2): 1-5, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32270661

RESUMO

Collagenated heretologous cortico-cancelleus bone mix (CHCCBM) is largely employed in maxillary and dental surgery for regeneration procedures, and is similar to human bone from chemical and physical point of view and promotes osteogenesis. In order to get more inside how this biomaterial induces osteoblast gene expression to promote bone formation, the mRNA levels of bone related genes were compared in human osteoblasts and dental pulp stem cells, using real time RT-PCR. The obtained results demonstrated that CHCCBM enhance stem cells differentiation and deposition of matrix by the activation of osteoblast related genes SP7, FOSL1 and SPP1.


Assuntos
Polpa Dentária/citologia , Osteoblastos/citologia , Osteogênese , Células-Tronco/citologia , Diferenciação Celular , Células Cultivadas , Humanos , Osteopontina/genética , Proteínas Proto-Oncogênicas c-fos/genética , RNA Mensageiro/genética , Fator de Transcrição Sp7/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA