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1.
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
2.
J Bone Miner Metab ; 38(5): 648-657, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32350616

RESUMO

INTRODUCTION: Lactoferrin has recently been reported for its potent bone growth effects. However, the effects of lactoferrin on the healing process of fragility fracture have not yet been studied, so the purpose of this study is to investigate whether oral administration of lactoferrin can promote the fracture healing in an OVX animal model. MATERIALS AND METHODS: Three months after bilateral ovariectomy, all rats underwent unilateral tibial osteotomy and were then randomly divided into control group and bovine lactoferrin (bLF) group. At 4 and 8 weeks post-fracture, animals were sacrificed, and the fractured tibiae and serum samples were collected for evaluation. RESULTS: Our results showed that bLF treatment not only accelerated the bone growth at an early stage of OPF healing but also shortened the remolding process of OPF healing. When compared to control group, bLF treatment induced a significant rise in callus BMD (by 35.0% at 4 weeks and by 39.7% at 8 weeks; both p < 0.05) consistent with enhanced biomechanical strength of the callus, with ultimate force increased by 3.39-fold at 4 weeks (p < 0.05) and 1.95-fold at 8 weeks (p < 0.05). Besides, bLF administration resulted in a substantial increase in serum levels of BALP and a significant decrease in serum levels of TRAP 5b and TNF-α. Moreover, both the RANKL/OPG mRNA ratio and the expression of TNF-α in the callus of bLF-treated group were markedly lower than those in the control group. CONCLUSIONS: At a dose of 85mg/kg/day orally administrated bLF potently promoted the bone healing following tibial fracture in OVX rats.


Assuntos
Consolidação da Fratura/efeitos dos fármacos , Lactoferrina/administração & dosagem , Lactoferrina/farmacologia , Ovariectomia , Absorciometria de Fóton , Administração Oral , Fosfatase Alcalina/sangue , Animais , Fenômenos Biomecânicos/efeitos dos fármacos , Densidade Óssea/efeitos dos fármacos , Calo Ósseo/diagnóstico por imagem , Calo Ósseo/efeitos dos fármacos , Calo Ósseo/patologia , Feminino , Humanos , Lactoferrina/sangue , Osteoprotegerina/metabolismo , Ligante RANK/metabolismo , Ratos Sprague-Dawley , Fosfatase Ácida Resistente a Tartarato/sangue , Tíbia/efeitos dos fármacos , Tíbia/patologia , Fator de Necrose Tumoral alfa/sangue , Microtomografia por Raio-X
3.
Biochem Biophys Res Commun ; 526(4): 1125-1130, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32331833

RESUMO

The regeneration of bone defects is necessary for the successful healing. During the process of healing, callus plays crucial roles in providing the stable bone-reconstruction environment. The callus is consisted of various large molecules including collagen proteins, non-collagen proteins and proteoglycans (PGs), which are involved in maintaining mechanical strength and interacting with cytokines and grow factors in the injury sites. Recently, our data have found that the PG form of Dentin Matrix Protein 1 (DMP1-PG), which is a newly identified PG, was richly expressed in the bone defect sites. Previous researches have demonstrated the special role of DMP1-PG in chondrogenesis and endochondral ossification, however, the knowledge about the role of DMP1-PG in bone defect repair is still limited. To further detect the potential function of DMP1-PG in the defect healing, we employed a bone defect intramembranous ossification model using the glycosylation site mutant DMP1-PG (S89-G89, S89G-DMP1) mouse. The morphologic changes of calluses and abnormal expression levels of osteogenesis genes were displayed in the injury sites in S89G-DMP1 mice. In addition, impaired BMP-Smad signaling pathway was observed due to the deficiency of DMP1-PG. Collectively, our findings indicated that the DMP1-PG is one of key proteoglycans in the process of defect healing via regulating the osteogenesis.


Assuntos
Osso e Ossos/metabolismo , Osso e Ossos/patologia , Proteínas da Matriz Extracelular/metabolismo , Animais , Proteínas Morfogenéticas Ósseas/metabolismo , Calo Ósseo/patologia , Diferenciação Celular , Modelos Animais de Doenças , Regulação para Baixo , Glicosilação , Masculino , Camundongos Transgênicos , Osteogênese , Proteoglicanas/metabolismo , Transdução de Sinais , Proteínas Smad/metabolismo
4.
Dis Model Mech ; 12(9)2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31383797

RESUMO

Reduced bone quality or mineral density predict susceptibility to fracture and also attenuate subsequent repair. Bone regrowth is also compromised by bacterial infection, which exacerbates fracture site inflammation. Because of the cellular complexity of fracture repair, as well as genetic and environmental influences, there is a need for models that permit visualisation of the fracture repair process under clinically relevant conditions. To characterise the process of fracture repair in zebrafish, we employed a crush fracture of fin rays, coupled with histological and transgenic labelling of cellular responses; the results demonstrate a strong similarity to the phased response in humans. We applied our analysis to a zebrafish model of osteogenesis imperfecta (OI), which shows reduced bone quality, spontaneous fractures and propensity for non-unions. We found deficiencies in the formation of a bone callus during fracture repair in our OI model and showed that clinically employed antiresorptive bisphosphonates can reduce spontaneous fractures in OI fish and also measurably reduce fracture callus remodelling in wild-type fish. The csf1ra mutant, which has reduced osteoclast numbers, also showed reduced callus remodelling. Exposure to excessive bisphosphonate, however, disrupted callus repair. Intriguingly, neutrophils initially colonised the fracture site, but were later completely excluded. However, when fractures were infected with Staphylococcus aureus, neutrophils were retained and compromised repair. This work elevates the zebrafish bone fracture model and indicates its utility in assessing conditions of relevance to an orthopaedic setting with medium throughput.This article has an associated First Person interview with the first author of the paper.


Assuntos
Fraturas Ósseas/patologia , Peixe-Zebra/fisiologia , Alendronato/farmacologia , Alendronato/uso terapêutico , Nadadeiras de Animais/patologia , Animais , Calo Ósseo/efeitos dos fármacos , Calo Ósseo/patologia , Difosfonatos/farmacologia , Difosfonatos/uso terapêutico , Modelos Animais de Doenças , Consolidação da Fratura/efeitos dos fármacos , Fraturas Ósseas/tratamento farmacológico , Fraturas Ósseas/microbiologia , Fraturas não Consolidadas/patologia , Osteoclastos/efeitos dos fármacos , Osteoclastos/patologia , Osteogênese Imperfeita/patologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia
5.
Bone ; 127: 577-591, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31369916

RESUMO

Bone fracture repair represents an important clinical challenge with nearly 1 million non-union fractures occurring annually in the U.S. Gene expression differs between non-union and healthy repair, suggesting there is a pattern of gene expression that is indicative of optimal repair. Despite this, the gene expression profile of fracture repair remains incompletely understood. In this work, we used RNA-seq of two well-established murine fracture models to describe gene expression of intramembranous and endochondral bone formation. We used top differentially expressed genes, enriched gene ontology terms and pathways, callus cellular phenotyping, and histology to describe and contrast these bone formation processes across time. Intramembranous repair, as modeled by ulnar stress fracture, and endochondral repair, as modeled by femur full fracture, exhibited vastly different transcriptional profiles throughout repair. Stress fracture healing had enriched differentially expressed genes associated with bone repair and osteoblasts, highlighting the strong osteogenic repair process of this model. Interestingly, the PI3K-Akt signaling pathway was one of only a few pathways uniquely enriched in stress fracture repair. Full fracture repair involved a higher level of inflammatory and immune cell related genes than did stress fracture repair. Full fracture repair also differed from stress fracture in a robust downregulation of ion channel genes following injury, the role of which in fracture repair is unclear. This study offers a broad description of gene expression in intramembranous and endochondral ossification across several time points throughout repair and suggests several potentially intriguing genes, pathways, and cells whose role in fracture repair requires further study.


Assuntos
Fraturas Ósseas/genética , Perfilação da Expressão Gênica , Osteogênese/genética , Transcrição Genética , Animais , Calo Ósseo/patologia , Progressão da Doença , Feminino , Consolidação da Fratura/genética , Fraturas de Estresse/patologia , Regulação da Expressão Gênica , Ontologia Genética , Membranas , Camundongos Endogâmicos C57BL , Fenótipo , Análise de Componente Principal , RNA-Seq , Reprodutibilidade dos Testes
6.
Biomed Res Int ; 2019: 6592464, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31139643

RESUMO

To find a simple and noninvasive method to promote fracture healing, we are trying to explore whether repetitive brief ischemia would promote bone healing. 88 rats divided into 6 groups were used to make right tibia closed fracture caused by the heavy weight collision method. Healthy side groups received homemade tourniquet placed on left and affected side group placed on right thigh 10 min inflated/10 min deflated 3 times every 24 hours or 48 hours after tibia fractured. Rats in control groups received homemade tourniquet uninflated placed on right thigh 1 hour every 24 hours or 48 hours. X-rays were checked at 1, 2, and 4 weeks. Micro-CT inspected the bone healing at 2 and 4 weeks. Serum cytokines, such as bone morphogenetic protein-2 (BMP-2), vascular endothelial growth factor (VEGF), diethanolamine enzyme activity unit of alkaline phosphatase (ALP) and transforming growth factor-ß1 (TGF-ß1), interleukin 10 (IL-10) and interleukin 6 (IL-6), were checked at 1, 2, and 4 weeks. Local histology was evaluated at 2 weeks. HE dye and BMP-2, VEGF, TGF-ß, and ALP immunohistochemical stains were made. Callus areas of posterior-anterior and lateral views were calculated and repetitive brief ischemia increased the callus areas ratio at 1 and 2 weeks. Besides, from micro-CT results, repetitive brief ischemia increased the bone volume (BV) at 2 and 4 weeks and also increased the total bone tissue volume (TV) at 2 weeks and BV/TV at 4 weeks. The serum cytokines, such as BMP-2, VEGF, diethanolamine enzyme activity unit of ALP and TGF-ß1, have increased by repetitive brief ischemia at 1, 2 weeks. It is opposite of affected side group that the level of serum IL-10 increased and IL-6 decreased in healthy side group at 1, 2 weeks. Repetitive brief ischemia increased the callus area at 2 weeks and boosted the synthesis of BMP-2, VEGF, TGF-ß, and ALP in the fracture region at 2 weeks from tissue stains. Repetitive brief ischemia promotes bone healing no matter on the affected side or the healthy side limb.


Assuntos
Consolidação da Fratura , Isquemia/patologia , Tíbia/irrigação sanguínea , Tíbia/lesões , Fraturas da Tíbia/patologia , Animais , Calo Ósseo/patologia , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Ratos Sprague-Dawley , Tíbia/diagnóstico por imagem , Fraturas da Tíbia/diagnóstico por imagem , Microtomografia por Raio-X
7.
J Bone Miner Res ; 34(9): 1690-1706, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31081125

RESUMO

Bone formation via intramembranous and endochondral ossification is necessary for successful healing after a wide range of bone injuries. The pleiotropic cytokine, vascular endothelial growth factor A (VEGFA) has been shown, via nonspecific pharmacologic inhibition, to be indispensable for angiogenesis and ossification following bone fracture and cortical defect repair. However, the importance of VEGFA expression by different cell types during bone healing is not well understood. We sought to determine the role of VEGFA from different osteoblast cell subsets following clinically relevant models of bone fracture and cortical defect. Ubiquitin C (UBC), Osterix (Osx), or Dentin matrix protein 1 (Dmp1) Cre-ERT2 mice (male and female) containing floxed VEGFA alleles (VEGFAfl/fl ) were either given a femur full fracture, ulna stress fracture, or tibia cortical defect at 12 weeks of age. All mice received tamoxifen continuously starting 2 weeks before bone injury and throughout healing. UBC Cre-ERT2 VEGFAfl/fl (UBC cKO) mice, which were used to mimic nonspecific inhibition, had minimal bone formation and impaired angiogenesis across all bone injury models. UBC cKO mice also exhibited impaired periosteal cell proliferation during full fracture, but not stress fracture repair. Osx Cre-ERT2 VEGFAfl/fl (Osx cKO) mice, but not Dmp1 Cre-ERT2 VEGFAfl/fl (Dmp1 cKO) mice, showed impaired periosteal bone formation and angiogenesis in models of full fracture and stress fracture. Neither Osx cKO nor Dmp1 cKO mice demonstrated significant impairments in intramedullary bone formation and angiogenesis following cortical defect. These data suggest that VEGFA from early osteolineage cells (Osx+), but not mature osteoblasts/osteocytes (Dmp1+), is critical at the time of bone injury for rapid periosteal angiogenesis and woven bone formation during fracture repair. Whereas VEGFA from another cell source, not from the osteoblast cell lineage, is necessary at the time of injury for maximum cortical defect intramedullary angiogenesis and osteogenesis. © 2019 American Society for Bone and Mineral Research.


Assuntos
Linhagem da Célula , Consolidação da Fratura , Osteoblastos/metabolismo , Fator de Transcrição Sp7/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Calo Ósseo/patologia , Proliferação de Células , Proteínas da Matriz Extracelular/metabolismo , Fraturas de Estresse/patologia , Deleção de Genes , Integrases/metabolismo , Camundongos , Neovascularização Fisiológica , Osteogênese , Periósteo/metabolismo
8.
J Cell Physiol ; 234(11): 19824-19832, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30980397

RESUMO

The cross-talk between cells is very critical for moving forward fracture healing in an orderly manner. Connexin (Cx) 43-formed gap junctions and hemichannels mediate the communication between adjacent cells and cells and extracellular environment. Loss of Cx43 in osteoblasts/osteocytes results in delayed fracture healing. For investigating the role of two channels in osteocytes in bone repair, two transgenic mouse models with Cx43 dominant negative mutants driven by a 10 kb-DMP1 promoter were generated: R76W (gap junctions are blocked, whereas hemichannels are promoted) and Δ130-136 (both gap junctions and hemichannels are blocked). R76W mice (promotion of hemichannels) showed a significant increase of new bone formation, whereas delayed osteoclastogenesis and healing was observed in Δ130-136 (impairment of gap junctions), but not in R76W mice (hemichannel promotion may recover the delay). These results suggest that gap junctions and hemichannels play some similar and cooperative roles in bone repair.


Assuntos
Conexina 43/metabolismo , Consolidação da Fratura , Osteócitos/metabolismo , Animais , Calo Ósseo/patologia , Cartilagem/patologia , Junções Comunicantes/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Osteogênese
9.
Mater Sci Eng C Mater Biol Appl ; 101: 415-422, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31029335

RESUMO

High nitrogen nickel-free stainless steel (HNNFSS) has excellent mechanical properties, corrosion resistance and biocompatibility, but its strength advantage is not fully used even though with one time higher than that of the conventional 316 L stainless steel. In this work, the lightweight design of HNNFSS bone plate was studied using finite element analysis, and the effect of lightweight plate fixation on histological and biomechanical behavior of healing bone were also researched on fractured rabbit femur. The finite element analysis results showed that the lightweight plate within 18.2% thickness reduction had higher bending strength and more homogeneous stress distribution compared with 316 L stainless steel plate. There was no obvious difference in radiography, histology analysis of callus and expression pattern of insulin like growth factor-1(IGF-1) of callus between the lightweight HNNFSS plate group and 316 L stainless steel plate group in animal test, and the IGF-1 concentrations of callus and the biomechanical bending test results also showed no statistical significance (p > 0.05), even though the data of the lightweight HNNFSS plate group were relatively better than that of 316 L stainless steel plate group. Therefore, the high nitrogen nickel-free stainless steel has the lightweight potential to keep good fixing function and improve bone healing compared with 316 L stainless steel plate.


Assuntos
Placas Ósseas , Teste de Materiais , Níquel/química , Aço Inoxidável/química , Animais , Fenômenos Biomecânicos , Calo Ósseo/diagnóstico por imagem , Calo Ósseo/patologia , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/patologia , Fraturas do Fêmur/cirurgia , Análise de Elementos Finitos , Consolidação da Fratura , Fator de Crescimento Insulin-Like I/metabolismo , Coelhos
10.
Med Sci Monit ; 25: 3133-3139, 2019 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-31030207

RESUMO

BACKGROUND Osteoporosis is an increasingly prevalent disease characterized by decreased bone mass and deterioration of the bone microstructure, which contribute to increased fragility and subsequent fragility fractures, especially in elderly individuals. Rhizoma Drynariae (DRE) is among the most frequently used herbal medicines for the treatment of osteoporosis. Transdermal delivery is a proven novel pathway for drug treatment and has several advantages over traditional drug delivery routes. MATERIAL AND METHODS Female Sprague-Dawley osteoporotic fracture model rats were divided into 3 groups: the control group, the DRE (90 mg/kg/day) group and the DRE cataplasm (containing 30 mg DRE, administered at right femur site daily) group. At 3 and 6 weeks after operation, we performed x-ray, histological, and biomechanical analyses, and evaluated bone marrow density of the femur. RESULTS Treatment with DRE increased callus formation and bone union compared with the control group. Moreover, DRE enhanced bone strength at the femoral diaphysis in the osteoporotic fractures in rats by increasing the ultimate load and stiffness compared with the control group. Furthermore, DRE restored the trabecular bone mineral density in the femur compared with the control group. DRE cataplasm application further enhanced the therapeutic effects against osteoporotic fracture in this rat model. CONCLUSIONS DRE cataplasm application might be useful against osteoporotic fracture.


Assuntos
Consolidação da Fratura/efeitos dos fármacos , Fraturas por Osteoporose/tratamento farmacológico , Polypodiaceae/metabolismo , Animais , Densidade Óssea/efeitos dos fármacos , Calo Ósseo/patologia , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/farmacologia , Feminino , Fraturas do Fêmur/tratamento farmacológico , Fêmur/patologia , Medicina Tradicional Chinesa/métodos , Osteoporose/tratamento farmacológico , Fraturas por Osteoporose/patologia , Ratos , Ratos Sprague-Dawley , Rizoma/química
11.
Exp Gerontol ; 122: 1-9, 2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-30998964

RESUMO

Fracture healing in the elderly is associated with a declined healing potential caused by multiple factors including a delay of vascularization. Erythropoietin (EPO) has been demonstrated to improve vascularization and fracture healing in adult mice. We, therefore, hypothesized that EPO in aged mice also improves fracture healing. For this purpose, EPO was given daily in a femoral fracture model in aged mice and compared to vehicle-treated controls using radiological, biomechanical, histomorphometric and Western blot techniques. Blood analyses revealed significantly higher concentrations of hemoglobin and a higher hematocrit in EPO-treated animals at 14 and 35 days after fracture. Micro-computed tomography (µCT) indicated that the fraction of bone volume/tissue volume within the callus did not differ between the two groups. However, µCT showed a 3-fold increased tissue mineral density (TMD) in the callus of EPO-treated animals compared to controls. The callus TMD of the EPO-treated animals was also 2-fold higher when compared to the TMD of the unfractured contralateral femur. Interestingly, biomechanical analyses revealed a reduced bending stiffness in femurs of EPO-treated animals at day 35. The histomorphometrically analyzed callus size and callus composition did not show significant differences between the study groups. However, Western blot analyses exhibited an increased expression of osteoprotegerin (OPG), but in particular of receptor activator of NF-κB ligand (RANKL) in the callus of the EPO-treated animals. Further histological analyses of the callus tissue showed that this was associated with an increased number of newly formed blood vessels and a higher number of tartrate-resistant acid phosphatase (TRAP)+ cells. Conclusion: In fracture healing of aged mice EPO treatment increases callus TMD as well as OPG and RANKL expression, indicating an accelerated bone turnover when compared to controls. However, EPO does not improve fracture healing in aged mice. The process of fracture healing may be altered by EPO due to a deterioration of the microcirculation caused by the worsened rheological properties of the blood and due to an increased bone fragility caused by the accelerated bone turnover. Thus, EPO may not be used to improve fracture healing in the elderly.


Assuntos
Envelhecimento , Remodelação Óssea/efeitos dos fármacos , Eritropoetina/administração & dosagem , Fraturas do Fêmur/tratamento farmacológico , Consolidação da Fratura/efeitos dos fármacos , Animais , Fenômenos Biomecânicos , Calo Ósseo/patologia , Feminino , Fraturas do Fêmur/diagnóstico por imagem , Hemoglobinas/metabolismo , Masculino , Camundongos , Osteoprotegerina/metabolismo , Ligante RANK/metabolismo , Microtomografia por Raio-X
12.
Biomed Res Int ; 2019: 4250940, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30891456

RESUMO

The cyclic axial dynamisation of a stabilised fracture is intended to promote callus formation and bone healing. Most studies focused on biomechanical properties or the quantity of new bone formation. Far less is known about the quality of newly formed callus tissues, such as tissue distribution and arrangement within the callus. The aim of this current study was to investigate the effect of cyclic, axial dynamisation on the quantity and quality of callus in an established delayed fracture healing model. In 41 sheep transverse osteotomies with a gap size of 3 mm were stabilised with a unilateral external fixator. In 32 of these, fracture ends were axially stimulated with displacement amplitudes of 0.8 mm, 0.4 mm, 0.2 mm, or 0.0 mm, respectively, for six weeks. In the remaining 9 sheep of the control group, an additional external fixator was mounted to achieve almost total rigidity. Animal material originating from a past animal experiment was reanalysed in this study. Histological thin-ground sections were histomorphometrically analysed regarding the histological structure and composition of the defect region. A slight tendency towards an increase in size of total callus area, area of new bone (nB.Ar), and cartilage (Cg.Ar) was detected with increasing displacement amplitudes compared to the control group. At the anterior callus side nB.Ar and Cg.Ar were significantly larger than at the posterior side in all groups independent of treatment. Regarding the quality of callus, areas of very compact bone were predominant in the treatment groups whereas in the control group a slight shift to more porous bone was observed. No difference of callus compactness was observed between the anterior and the posterior side. The established method to assess the local compactness of callus areas is a useful tool to quantitatively determine the spatial distribution of new bone tissue within the callus. The application of this method in combination with biomechanical testing might reveal interesting relations between tissue distribution and bone strength that, with traditional histomorphometry, cannot be identified.


Assuntos
Calo Ósseo/patologia , Osteotomia , Ovinos/cirurgia , Animais , Densidade Óssea , Cartilagem/patologia , Modelos Animais de Doenças , Fixadores Externos , Feminino
13.
Injury ; 50(4): 956-961, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30878260

RESUMO

OBJECTIVE: Extensive incision associated with large-scale callus exfoliation and internal fixation is the common therapeutic approach employed by the majority of orthopaedists in the treatment of old femoral fractures. Inspired by the surgical techniques of intramedullary fixation and reduction by traction, the present study attempted to treat old femoral fractures with minimally invasive methods utilising the principles of biological osteosynthesis (BO). METHODS: A retrospective analysis involving 16 patients with old femoral fractures treated with combined traction, small incision, limited callus treatment, reduction by leverage and intramedullary fixation was conducted. The operative effect was evaluated by the operation time, intraoperative blood loss, bone grafting, healing time of fractures during follow-up, VAS score, and Harris hip score. RESULTS: Intraoperative observation revealed an average operation time of 1.53 ± 0.34 h and average blood loss of 268.13 ± 97.29 ml without bone grafting in all patients. All enrolled patients had outcomes resulting in effective fixation restoration of limb alignment. Of the 16 enrolled patients, 13 patients completed follow-up with an average follow-up time of 7.42 ± 3.29 months. The average healing time for proximal femoral fractures was 3 months. The average healing time of femoral shaft fractures was 4 ± 1.09 months; two of these cases took 4 months to heal, whereas 1 case demonstrated a delayed healing time of 6 months. The VAS score was 1.15 ± 1.70, 1 patient experienced sciatica, and the Harris hip score was 92.92 ± 5.42. There were no complications of malunion, nonunion or infection among any of the patients who completed follow-up. CONCLUSIONS: Minimally invasive treatment is feasible for most patients with old femoral fractures of the trochanter and femoral shaft. This finding is consistent with BO principles, thereby providing a possible new method for the treatment of old femoral fractures.


Assuntos
Calo Ósseo/patologia , Fraturas do Fêmur/patologia , Fêmur/patologia , Fixação Intramedular de Fraturas/métodos , Consolidação da Fratura/fisiologia , Procedimentos Cirúrgicos Minimamente Invasivos , Adulto , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea , Transplante Ósseo/estatística & dados numéricos , Feminino , Fraturas do Fêmur/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
14.
Int J Oncol ; 54(5): 1704-1718, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30816440

RESUMO

Oncogenic drivers of osteosarcoma remain controversial due to the complexity of the genomic background of the disease. There are limited novel therapeutic options, and the survival rate of patients with osteosarcoma has not improved in decades. Genomic instability leads to complexity in various pathways, which is potentially revealed at the protein level. Therefore, the present study aimed to identify the mechanisms involved in the oncogenesis of osteosarcoma using proteomics and bioinformatics tools. As clinical specimens from patients are the most relevant disease­related source, expression patterns of proteins in osteosarcoma tissues were compared with soft tissue callus from donors containing high numbers of osteoblastic cells. Two­dimensional electrophoresis and liquid chromatography­tandem mass spectrometry (LC­MS/MS) successfully identified 33 differentially expressed proteins in the osteosarcoma tissues compared with the soft tissue callus. Among these proteins, 29 proteins were significantly upregulated in osteosarcoma. A functionally grouped network of the overexpressed proteins, that was created using the ClueGo and CluePedia applications, demonstrated that the unfolded protein response (UPR) pathway was activated mainly through the activating transcription factor 6 arm in osteosarcoma. The results of proteomics analysis were confirmed by elevated expression of UPR­related chaperone proteins, including 78 kDa glucose­related protein (GRP78), endoplasmin, calreticulin and prelamin­A/C, in the patient­derived primary cells and osteosarcoma cell lines. Furthermore, the expression of GRP78, a master regulator of the UPR, was enhanced in the osteosarcoma tissues of patients that were resistant to double regimen of doxorubicin and a platinum­based drug. The findings of the present study suggest that targeting the UPR pathway may be promising for the treatment of osteosarcoma.


Assuntos
Neoplasias Ósseas/patologia , Calo Ósseo/patologia , Redes Reguladoras de Genes , Osteossarcoma/patologia , Proteômica/métodos , Resposta a Proteínas não Dobradas , Adolescente , Adulto , Neoplasias Ósseas/metabolismo , Calo Ósseo/metabolismo , Linhagem Celular Tumoral , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteossarcoma/metabolismo , Adulto Jovem
15.
Acta Biomater ; 86: 171-184, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30616076

RESUMO

Although several biomaterials for bone regeneration have been developed in the last decades, clinical application of bone morphogenetic protein 2 is clinically only approved when applied on an absorbable bovine collagen I scaffold (ACS) (Helistat; ACS-H). In research, another ACS, namely Lyostypt (ACS-L) is frequently used as a scaffold in bone-linked studies. Nevertheless, until today, the influence of ACS alone on bone healing remains unknown. Unexpectedly, in vitro studies using ASC-H revealed a suppression of osteogenic differentiation and a significant reduction of cell vitality when compared to ASC-L. In mice, we observed a significant delay in bone healing when applying ACS-L in the fracture gap during femoral osteotomy. The results of our study show for the first time a negative influence of both ACS-H and ACS-L on bone formation demonstrating a substantial need for more sophisticated delivery systems for local stimulation of bone healing in both clinical application and research. STATEMENT OF SIGNIFICANCE: Our study provides evidence-based justification to promote the development and approval of more suitable and sophisticated delivery systems in bone healing research. Additionally, we stimulate researchers of the field to consider that the application of those scaffolds as a delivery system for new substances represents a delayed healing approach rather than a normal bone healing which could greatly impact the outcome of those studies and play a pivotal role in the translation to the clinics. Moreover, we provide impulses on underlying mechanism involving the roles of small-leucine rich proteoglycans (SLRP) for further detailed investigations.


Assuntos
Colágeno Tipo I/farmacologia , Consolidação da Fratura/efeitos dos fármacos , Osteotomia , Tecidos Suporte/química , Animais , Regeneração Óssea/efeitos dos fármacos , Calo Ósseo/patologia , Calcificação Fisiológica/efeitos dos fármacos , Cartilagem/efeitos dos fármacos , Cartilagem/patologia , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Colágeno Tipo I/ultraestrutura , Modelos Animais de Doenças , Endotélio/efeitos dos fármacos , Feminino , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Tamanho do Órgão , Fator de Necrose Tumoral alfa/metabolismo , Microtomografia por Raio-X
16.
J Bone Miner Res ; 34(3): 520-532, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30602062

RESUMO

Atrophic nonunion represents an extremely challenging clinical dilemma for both physicians and fracture patients alike, but its underlying mechanisms are still largely unknown. Here, we established a mouse model that recapitulates clinical atrophic nonunion through the administration of focal radiation to the long bone midshaft 2 weeks before a closed, semistabilized, transverse fracture. Strikingly, fractures in previously irradiated bone showed no bony bridging with a 100% nonunion rate. Radiation triggered distinct repair responses, separated by the fracture line: a less robust callus formation at the proximal side (close to the knee) and bony atrophy at the distal side (close to the ankle) characterized by sustained fibrotic cells and type I collagen-rich matrix. These fibrotic cells, similar to human nonunion samples, lacked osteogenic and chondrogenic differentiation and exhibited impaired blood vessel infiltration. Mechanistically, focal radiation reduced the numbers of periosteal mesenchymal progenitors and blood vessels and blunted injury-induced proliferation of mesenchymal progenitors shortly after fracture, with greater damage particularly at the distal side. In culture, radiation drastically suppressed proliferation of periosteal mesenchymal progenitors. Radiation did not affect hypoxia-induced periosteal cell chondrogenesis but greatly reduced osteogenic differentiation. Lineage tracing using multiple reporter mouse models revealed that mesenchymal progenitors within the bone marrow or along the periosteal bone surface did not contribute to nonunion fibrosis. Therefore, we conclude that atrophic nonunion fractures are caused by severe damage to the periosteal mesenchymal progenitors and are accompanied by an extraskeletal, fibro-cellular response. In addition, we present this radiation-induced periosteal damage model as a new, clinically relevant tool to study the biologic basis of therapies for atrophic nonunion. © 2018 American Society for Bone and Mineral Research.


Assuntos
Calo Ósseo/metabolismo , Fraturas Ósseas/metabolismo , Fraturas não Consolidadas/metabolismo , Células-Tronco Mesenquimais/metabolismo , Periósteo/metabolismo , Animais , Calo Ósseo/patologia , Condrogênese/genética , Fibrose , Fraturas Ósseas/genética , Fraturas Ósseas/patologia , Fraturas não Consolidadas/genética , Fraturas não Consolidadas/patologia , Masculino , Células-Tronco Mesenquimais/patologia , Camundongos , Camundongos Transgênicos , Periósteo/patologia
17.
Mol Med Rep ; 19(3): 1867-1874, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30592272

RESUMO

Fracture healing in elderly patients is an emerging public health concern. As non­drug treatments, intermittent hypoxia training (IHT) and remote ischemic preconditioning (RIPC) are considered to have substantial advantages and to aid fracture healing in elderly patients. The purpose of the present study was to evaluate and compare the effects of IHT and RIPC on fracture healing. Micro­computed tomography (micro­CT) and biomechanical testing were used to assess the morphology and structural properties of bone callus dissected from aged rats with tibial fractures. In addition, hypoxia­inducible factor­1α (HIF­1α) and its target gene, associated with the healing process, were investigated by reverse transcription­quantitative polymerase chain reaction and western blot analyses. The micro­CT­based parameters, including bone mineral density and trabecular number, were measured, and significant differences were identified between the experimental and control groups. The IHT group exhibited superior bone formation and mineralization rates compared with the RIPC group. The biomechanical testing revealed that the ultimate loading and stiffness values were significantly higher in the IHT group compared with those in the RIPC group. In accordance with previous studies, RIPC exerted a similar effect in increasing the expression of HIF­1α, and its downstream genes, throughout the course of healing. In addition, the IHT group exhibited increased expression levels of HIF­1α compared with the RIPC group. Taken together, the results suggested that IHT and RIPC significantly enhanced fracture healing; however, IHT exhibited superior bone formation and healing effects compared with RIPC.


Assuntos
Consolidação da Fratura , Hipóxia/patologia , Precondicionamento Isquêmico , Fosfatase Alcalina/metabolismo , Animais , Fenômenos Biomecânicos , Calo Ósseo/metabolismo , Calo Ósseo/patologia , Calcificação Fisiológica , Diferenciação Celular , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Hipóxia/genética , Hipóxia/fisiopatologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Masculino , Osteoblastos/patologia , Osteocalcina/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Tíbia/diagnóstico por imagem , Tíbia/patologia , Tíbia/fisiopatologia , Fraturas da Tíbia/diagnóstico por imagem , Fraturas da Tíbia/patologia , Fraturas da Tíbia/fisiopatologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Microtomografia por Raio-X
18.
Int J Mol Sci ; 19(11)2018 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-30423942

RESUMO

The development of new and better implant materials adapted to osteoporotic bone is still urgently required. Therefore, osteoporotic muscarinic acetylcholine receptor M3 (M3 mAChR) knockout (KO) and corresponding wild type (WT) mice underwent osteotomy in the distal femoral metaphysis. Fracture gaps were filled with a pasty α-tricalcium phosphate (α-TCP)-based hydroxyapatite (HA)-forming bone cement containing mesoporous bioactive CaP-SiO2 glass particles (cement/MBG composite) with or without Brain-Derived Neurotrophic Factor (BDNF) and healing analyzed after 35 days. Histologically, bone formation was significantly increased in WT mice that received the BDNF-functionalized cement/MBG composite compared to control WT mice without BDNF. Cement/MBG composite without BDNF increased bone formation in M3 mAChR KO mice compared to equally treated WT mice. Mass spectrometric imaging showed that the BDNF-functionalized cement/MBG composite implanted in M3 mAChR KO mice was infiltrated by newly formed tissue. Leukocyte numbers were significantly lower in M3 mAChR KO mice treated with BDNF-functionalized cement/MBG composite compared to controls without BDNF. C-reactive protein (CRP) concentrations were significantly lower in M3 mAChR KO mice that received the cement/MBG composite without BDNF when compared to WT mice treated the same. Whereas alkaline phosphatase (ALP) concentrations in callus were significantly increased in M3 mAChR KO mice, ALP activity was significantly higher in WT mice. Due to a stronger effect of BDNF in non osteoporotic mice, higher BDNF concentrations might be needed for osteoporotic fracture healing. Nevertheless, the BDNF-functionalized cement/MBG composite promoted fracture healing in non osteoporotic bone.


Assuntos
Cimentos para Ossos/uso terapêutico , Fator Neurotrófico Derivado do Encéfalo/uso terapêutico , Fêmur/patologia , Consolidação da Fratura/efeitos dos fármacos , Vidro/química , Fraturas por Osteoporose/tratamento farmacológico , Fosfatase Alcalina/metabolismo , Animais , Cimentos para Ossos/farmacologia , Calo Ósseo/efeitos dos fármacos , Calo Ósseo/enzimologia , Calo Ósseo/patologia , Fator Neurotrófico Derivado do Encéfalo/farmacologia , Proteína C-Reativa/metabolismo , Modelos Animais de Doenças , Feminino , Fêmur/diagnóstico por imagem , Fêmur/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fraturas por Osteoporose/sangue , Fraturas por Osteoporose/diagnóstico por imagem , Fraturas por Osteoporose/patologia , Porosidade , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptor Muscarínico M3/metabolismo , Espectrometria por Raios X , Microtomografia por Raio-X
19.
J Orthop Surg Res ; 13(1): 267, 2018 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-30359257

RESUMO

BACKGROUND: Delay in fracture healing or non-union can be devastating complication. Recent studies have reported that teriparatide (TP) demonstrated effectively on callus formation and mechanical strength and zoledronate (ZA) increased the callus size and resistance at the fracture site in rat fracture model. In this study, the effects of combination therapy with low dose TP and ZA on fracture healing was evaluated. METHODS: From 1 week post-operation, TP (5 times a week administration) and ZA (0.1 mg/kg single administration) were administered by dividing the rats into the following five groups: TP 1 µg group {T(1): TP 1 µg/kg}, ZA group (ZA:0.1 mg/kg), TP1 µg+ZA group {T(1)+ZA: TP 1 µg/kg+ZA}, TP 10 µg+ZA group {T(10)+ZA: TP 10 µg/kg + ZA}, and control group (C: administered saline). Rt femurs were excised 7 weeks after the surgery; bone fusions were evaluated with soft X-ray images on a 4-point scale. And the histopathological examination was performed in demineralized and non-demineralized specimens. Furthermore, the Radiographic Union Scale was conducted in all specimens. RESULTS: About the bone fusions rates, C, T(1), ZA, T(1)+ZA, and T(10)+ZA groups demonstrated 20.0%, 55.6%, 70.0%, 70.0%, and 80.0%, respectively, and with 4-point scale, each group was 0.50, 1.56, 2.00, 2.60, and 2.80 points, respectively. The callus volume was significantly increased to 16.66 mm2 and 17.75 mm2 in the T(1)+ZA and T(10)+ZA groups, respectively, while 10.65 mm2 (p < 0.05) in the C group. Furthermore, the callus area in the T(10)+ZA group was also observed to have significantly increased to 78.78%, compared with 54.63% and 44.11% in the C and T(1)+ZA groups, respectively (p < 0.01). Histopathologically, cartilage tissue and immature callus formation were observed at the bone junction in the C group; however, the osseous bridge formation of mature callus was observed in the ZA, T(1)+ZA, and T(10)+ZA groups. CONCLUSION: It is suggested that administration of low dose TP and ZA in combination may lead to the treatment of delayed union of fracture. We hope the combination treatment may become one of new therapeutic strategy.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Fraturas do Fêmur/tratamento farmacológico , Consolidação da Fratura/efeitos dos fármacos , Teriparatida/uso terapêutico , Ácido Zoledrônico/uso terapêutico , Animais , Conservadores da Densidade Óssea/administração & dosagem , Conservadores da Densidade Óssea/farmacologia , Calo Ósseo/efeitos dos fármacos , Calo Ósseo/patologia , Modelos Animais de Doenças , Esquema de Medicação , Avaliação Pré-Clínica de Medicamentos/métodos , Quimioterapia Combinada , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/patologia , Fraturas do Fêmur/fisiopatologia , Masculino , Radiografia , Ratos Sprague-Dawley , Teriparatida/administração & dosagem , Teriparatida/farmacologia , Ácido Zoledrônico/administração & dosagem , Ácido Zoledrônico/farmacologia
20.
J Forensic Leg Med ; 60: 9-14, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30196192

RESUMO

OBJECTIVE: Skeletal survey is a commonly used means of detecting fractures in infants, and is used as a screen in suspected cases of physical abuse. It is recognised that in live infants, a repeat survey some days after a suspected episode of injury will detect more fractures than one taken shortly after the suspected injury, indicating that the latter lacks sensitivity. In infants who die soon after a suspected episode of physical abuse, the managing clinicians do not have the option of a second survey; however there is the opportunity for the microscopic examination of bones removed at autopsy. Increasingly Osteoarticular Pathology at the Manchester University NHS Foundation Trust (MFT) is being sent samples of bones from infants suspected of inflicted injury for histological examination, both from bones with fractures detected at autopsy or skeletal survey and from posterior ribs and long bone metaphyses (sites of significance in assessing for abusive injury) when there is no evidence of fracture on skeletal survey or autopsy. Here we report the results of an audit of the anonymised data from a series of such cases, to establish the sensitivity of skeletal survey (SS) to detect fractures and to define the medico-legal value of submitting bones for histological examination. METHODS: This was an audit of skeletal injuries in 38 infants aged <18 months presenting to MFT for specialist histopathological evaluation of suspected non-accidental fractures between January 2011 and June 2017. Histopathological examination was performed on all bones submitted and compared with contact radiography of isolated bones and post-mortem skeletal surveys undertaken by specialist paediatric or musculoskeletal radiologists for the presence of fracture. RESULTS: A total of 318 fractures were detected histologically; of these, 178 (56%) were of the ribs, 119 (37.5%) were of major limb long bones, 10 (3%) were of the skull, and 11 (3.5%) were recorded as 'other'. Excluding refractures, skeletal survey detected 54% of the fractures recorded histologically. No fractures were detected radiologically that were not seen histologically. Generally, for skeletal survey, detection rates improved with the age of the lesion, and rib fractures were more difficult to detect than long bone fractures. Ribs 5-8 were the most frequently fractured ribs, and metaphyses around the knee accounted for most metaphyseal limb long bone fractures undetected by SS. CONCLUSION: In infants coming to post-mortem, histopathology is more sensitive than SS for the detection of clinically significant fractures. In children suspected of non-accidental injuries but with negative or equivocal SS, sampling of the anterior and posterior end of ribs 5-8 and the bones around the knee for histological examination could reveal clinically unsuspected fractures and significant evidence of physical abuse. 71% of infants showed evidence of old fractures typical of non-accidental injury.


Assuntos
Maus-Tratos Infantis/diagnóstico , Fraturas Ósseas/patologia , Calo Ósseo/patologia , Patologia Legal , Fraturas Ósseas/diagnóstico por imagem , Hemorragia/patologia , Humanos , Lactente , Recém-Nascido , Auditoria Médica , Recidiva , Estudos Retrospectivos
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