Objective:To investigate the osteogenic effects of polyphenol-rich extracts from Wisteria floribunda(Willd.)DC.(W.floribunda)flowers and elucidate the underlying mechanisms.Methods:Polyphenolic compounds of W.floribun...Objective:To investigate the osteogenic effects of polyphenol-rich extracts from Wisteria floribunda(Willd.)DC.(W.floribunda)flowers and elucidate the underlying mechanisms.Methods:Polyphenolic compounds of W.floribunda extracts were analyzed,including flavonoids and glucoside derivatives.Osteogenic activity was assessed in MC3T3-E1 preosteoblast cells by measurement of alkaline phosphatase(ALP)activity,alizarin red S staining,and the expression of osteogenic markers(RUNX2,SP7,and ALPL).In vivo effects were evaluated in zebrafish larvae by assessing skeletal development and expression of osteogenic genes(runx2a,sp7,and alpl).The role of mammalian target of rapamycin(mTOR)pathway was examined using rapamycin.Results:W.floribunda extracts significantly enhanced ALP activity,bone mineralization,and the expression of RUNX2,SP7,and ALPL in MC3T3-E1 cells.In zebrafish larvae,W.floribunda extracts improved vertebral mineralization and upregulated osteogenic genes.Mechanistically,the plant extract activated the mTOR pathway,and rapamycin treatment attenuated the extracts-induced ALP activity,mineralization,and vertebral formation in zebrafish,confirming mTOR involvement.Conclusions:W.floribunda extracts promote osteoblast differentiation and bone formation via mTOR pathway activation.These findings provide novel insights into the potential of W.floribunda extracts and support its further investigation as a natural therapeutic candidate for bone degenerative disorders such as osteoporosis.展开更多
INTRODUCTIONThe transforming growth factor-β （TGF-β） superfamily com- prises TGF-βs, Activin, bone morphogenetic proteins （BMPs） and other related proteins. TGF-β superfamily members act through a heteromeric ...INTRODUCTIONThe transforming growth factor-β （TGF-β） superfamily com- prises TGF-βs, Activin, bone morphogenetic proteins （BMPs） and other related proteins. TGF-β superfamily members act through a heteromeric receptor complex,, comprised of type I and type II receptors at the cell surface that transduce intracellular signals via Smad complex or mitogen-activated protein kinase （MAPK） cascade.展开更多
Transforming growth factor-beta（TGF-β）/bone morphogenetic protein（BMP） plays a fundamental role in the regulation of bone organogenesis through the activation of receptor serine/threonine kinases. Perturbations o...Transforming growth factor-beta（TGF-β）/bone morphogenetic protein（BMP） plays a fundamental role in the regulation of bone organogenesis through the activation of receptor serine/threonine kinases. Perturbations of TGF-β/BMP activity are almost invariably linked to a wide variety of clinical outcomes, i.e., skeletal, extra skeletal anomalies, autoimmune, cancer, and cardiovascular diseases. Phosphorylation of TGF-β（I/II） or BMP receptors activates intracellular downstream Smads, the transducer of TGF-β/BMP signals. This signaling is modulated by various factors and pathways, including transcription factor Runx2. The signaling network in skeletal development and bone formation is overwhelmingly complex and highly time and space specific.Additive, positive, negative, or synergistic effects are observed when TGF-β/BMP interacts with the pathways of MAPK, Wnt, Hedgehog（Hh）, Notch, Akt/m TOR, and mi RNA to regulate the effects of BMP-induced signaling in bone dynamics. Accumulating evidence indicates that Runx2 is the key integrator, whereas Hh is a possible modulator, mi RNAs are regulators, and b-catenin is a mediator/regulator within the extensive intracellular network. This review focuses on the activation of BMP signaling and interaction with other regulatory components and pathways highlighting the molecular mechanisms regarding TGF-β/BMP function and regulation that could allow understanding the complexity of bone tissue dynamics.展开更多
RANKL signaling is essential for osteoclastogenesis. Its role in osteoblastic differentiation and bone formation is unknown. Here we demonstrate that RANK is expressed at an early stage of bone marrow mesenchymal stem...RANKL signaling is essential for osteoclastogenesis. Its role in osteoblastic differentiation and bone formation is unknown. Here we demonstrate that RANK is expressed at an early stage of bone marrow mesenchymal stem cells(BMSCs) during osteogenic differentiation in both mice and human and decreased rapidly. RANKL signaling inhibits osteogenesis by promoting β-catenin degradation and inhibiting its synthesis. In contrast, RANKL signaling has no significant effects on adipogenesis of BMSCs.Interestingly, conditional knockout of rank in BMSCs with Prx1-Cre mice leads to a higher bone mass and increased trabecular bone formation independent of osteoclasts. In addition, rank: Prx1-Cre mice show resistance to ovariectomy-(OVX) induced bone loss. Thus, our results reveal that RANKL signaling regulates both osteoclasts and osteoblasts by inhibition of osteogenic differentiation of BMSCs and promotion of osteoclastogenesis.展开更多
In the recent two decades, it has been well elucidated that receptor activator of nuclear factor-κB ligand （RANKL; also known as TNFSF11） binding to its receptor RANK （also known as TNFRSF11A） drives osteoclast d...In the recent two decades, it has been well elucidated that receptor activator of nuclear factor-κB ligand （RANKL; also known as TNFSF11） binding to its receptor RANK （also known as TNFRSF11A） drives osteoclast development as the crucial signaling pathway.;However, accumulating evidence also implies that展开更多
Lipoprotein receptor-related protein 6 （LRP6） plays a critical role in skeletal development and homeostasis in adults. However, the role of LRP6 in mesenchymal stem cells （MSCs）, skeletal stem cells that give rise...Lipoprotein receptor-related protein 6 （LRP6） plays a critical role in skeletal development and homeostasis in adults. However, the role of LRP6 in mesenchymal stem cells （MSCs）, skeletal stem cells that give rise to osteoblastic lineage, is unknown. In this study, we generated mice lacking LRP6 expression specifically in nestin＋ MSCs by crossing nestin-Cre mice with LRP6 flox mice and investigated the functional changes of bone marrow MSCs and skeletal alterations. Mice with LRP6 deletion in nestin＋ cells demonstrated reductions in body weight and body length at I and 3 months of age. Bone architecture measured by microCT （uCT） showed a significant reduction in bone mass in both trabecular and cortical bone of homozygous and heterozygous LRP6 mutant mice. A dramatic reduction in the numbers of osteoblasts but much less significant reduction in the numbers of osteoclasts was observed in the mutant mice. Osterix＋ osteoprogenitors and osteocalcin＋ osteoblasts significantly reduced at the secondary spongiosa area, but only moderately decreased at the primary spongiosa area in mutant mice. Bone marrow MSCs from the mutant mice showed decreased colony forming, cell viability and cell proliferation. Thus, LRP6 in bone marrow MSCs is essential for their survival and proliferation, and therefore, is a key positive regulator for bone formation during skeletal growth and remodeling.展开更多
The activation of M1 macrophages can be achieved by stimulating them with lipopolysaccharide （LPS） and interferon-γ （IFN-γ）. However, M1 can be found under physiological conditions without any pathological stimu...The activation of M1 macrophages can be achieved by stimulating them with lipopolysaccharide （LPS） and interferon-γ （IFN-γ）. However, M1 can be found under physiological conditions without any pathological stimuli. This study aimed to understand the involvement of RANKL-induced M1 macrophages in bone formation compared with pathologically induced macrophages. Fischer rats were used to investigate macrophage distribution in normal and injured femoral condyles in vivo. Bone marrow-derived macrophages （BMDMs） were activated with LPS＋IFN-γ and RANKL to achieve M1 activation in vitro. Gene expression related to inflammation, osteoclastogenesis, angiogenesis, and migration was determined by reverse transcription-quantitative polymerase chain reaction （RT-qPCR） and fluorescence-activated cell sorting （FACS）. Tissue macrophages showed distinct expression patterns at different bone regions. RANKL was found in close proximity to inducible nitric oxide synthase-positive （iNOS＋） cells in vivo, suggesting an association between RANKL expression and iNOS＋ cells, especially in trabecular bone. RANKL-induced macrophages showed a different cytokine secretion profile compared with pathologically induced macrophages. Both osteoclasts and M1 macrophages peaked on day 7 during bone healing. RANKL could trigger Ml-like macrophages with properties that were different from those of LPS＋IFN-γ-induced macrophages. These RANKL-activated M1 macrophages were actively involved in bone formation.展开更多
To study the new bone formation in the bone defect area after implantation, the tetracycline tracing method was used. The results show that new bone formed in 1 month, and the formation rate of new bone was very high ...To study the new bone formation in the bone defect area after implantation, the tetracycline tracing method was used. The results show that new bone formed in 1 month, and the formation rate of new bone was very high (8.164μm/day),considerably faster than that of control groups (3.219μm/day).The new bone grew up quickly and β-TCP particles were surrounded by double fluorescence bands which became more obvious. The new bone formation rate was maximal at 2 months, and then gradually reduced. The rate was steady at 4 months, and then reduced to resembling as the normal physiologic metabolism of bone, which indicated the implanted materials were completely replaced by bone. Calcium phosphate materials had the ability of osteoconduction.展开更多
Daily 20-mg and once-weekly 56.5-mg teriparatide（parathyroid hormone 1–34） treatment regimens increase bone mineral density（BMD） and prevent fractures, but changes in bone turnover markers differ between the two ...Daily 20-mg and once-weekly 56.5-mg teriparatide（parathyroid hormone 1–34） treatment regimens increase bone mineral density（BMD） and prevent fractures, but changes in bone turnover markers differ between the two regimens. The aim of the present study was to explain changes in bone turnover markers using once-weekly teriparatide with a simulation model. Temporary increases in bone formation markers and subsequent decreases were observed during once-weekly teriparatide treatment for 72 weeks. These observations support the hypothesis that repeated weekly teriparatide administration stimulates bone remodeling, replacing old bone with new bone and leading to a reduction in the active remodeling surface. A simulation model was developed based on the iterative remodeling cycle that occurs on residual old bone. An increase in bone formation and a subsequent decrease were observed in the preliminary simulation. For each fitted time point, the predicted value was compared to the absolute values of the bone formation and resorption markers and lumbar BMD. The simulation model strongly matched actual changes in bone turnover markers and BMD. This simulation model indicates increased bone formation marker levels in the early stage and a subsequent decrease. It is therefore concluded that remodeling-based bone formation persisted during the entire treatment period with once-weekly teriparatide.展开更多
The growth and enlargement of jaw cysts are associated with raised intracystic pressure and bone resorption surrounding the cysts.The major bone-resorbing cells are the osteoclasts.They are acting under the influence ...The growth and enlargement of jaw cysts are associated with raised intracystic pressure and bone resorption surrounding the cysts.The major bone-resorbing cells are the osteoclasts.They are acting under the influence of local bone-resorbing factors: prostaglandins,proteinases and cytokines.It was found that positive pressure enhanced the expression of IL-1αmRNA and protein in epithelial cells of odontogenic keratocyst,and increased the secretion of matrix metalloproteinase and PGE2 in a co-culture of odontogenic keratocyst fibroblasts and epithelial cells.However,the signal intensities for IL-1α mRNA and protein in the epithelium were significantly decreased after marsupialization which relived intracystic pressure.Experimental study indicated that intermittent negative pressure could promote osteogenesis in human bone marrow-derived stroma cells(BMSCs) in vitro.We propose a hypothesis that bone formation around the cyst of the jaws would be stimulated by intracystic negative pressure.展开更多
Ankylosing spondylitis(AS)has a very high disability rate.How to effectively inhibit the formation of new bones has become a difficult point in clinical treatment.In recent years,research has shown that different trea...Ankylosing spondylitis(AS)has a very high disability rate.How to effectively inhibit the formation of new bones has become a difficult point in clinical treatment.In recent years,research has shown that different treatment plans can have an impact on inhibiting new bone formation.In this paper,the different effects of new bone formation in the treatment of AS with traditional Chinese and Western medicine are systematically listed.展开更多
Objective To investigate the Wnt signaling pathway and miRNAs mechanism of extracts of Plastrum Testudinis(PT)in the treatment of osteoporosis(OP).Methods Thirty female Sprague Dawley rats were randomly divided into 5...Objective To investigate the Wnt signaling pathway and miRNAs mechanism of extracts of Plastrum Testudinis(PT)in the treatment of osteoporosis(OP).Methods Thirty female Sprague Dawley rats were randomly divided into 5 groups by random number table method,including sham group,ovariectomized group(OVX),ovariectomized groups treated with high-,medium-,and low-dose PT(160,80,40 mg/kg per day,respectively),with 6 rats in each group.Except for the sham group,the other rats underwent bilateral ovariectomy to simulate OP and received PT by oral gavage for 10 consecutive weeks.After treatment,bone mineral density was measured by dual-energy X-ray absorptiometry;bone microstructure was analyzed by micro-computed tomography and hematoxylin and eosin staining;and the expressions of osteogenic differentiation-related factors were detected by immunochemistry,Western blot,and quantitative polymerase chain reaction.In addition,Dickkopf-1(Dkk-1)was used to inhibit the Wnt signaling pathway in bone marrow mesenchymal stem cells(BMSCs)and miRNA overexpression was used to evaluate the effect of miR-214 on the osteogenic differentiation of BMSCs.Subsequently,PT extract was used to rescue the effects of Dkk-1 and miR-214,and its impacts on the osteogenic differentiation-related factors of BMSCs were evaluated.展开更多
Osteoporosis represents an increasing health and socioeconomic burden on aging societies.Current therapeutic options often come with potentially severe side effects or lack long-term efficacy,highlighting the urgent n...Osteoporosis represents an increasing health and socioeconomic burden on aging societies.Current therapeutic options often come with potentially severe side effects or lack long-term efficacy,highlighting the urgent need for more effective treatments.Identifying novel drug targets requires a thorough understanding of their physiological roles.Genome-wide association studies in humans have linked gene variants of the adhesion G protein-coupled receptor 133(GPR133/ADGRD1)to variations in bone mineral density and body height.In this study,we explore the impact of GPR133/ADGRD1 on osteoblast differentiation and function.Constitutive and osteoblast-specific knockouts of Gpr133/Adgrd1 in mice lead to reduced cortical bone mass and trabecularization in the femurs and vertebrae—features characteristic of osteoporosis.This osteopenic phenotype in receptor-deficient mice is caused by impaired osteoblast function,which,in turn,promotes increased osteoclast activity.At the molecular level,GPR133/ADGRD1 regulates osteoblast function and differentiation through a combined activation mechanism involving interaction with its endogenous ligand,protein tyrosine kinase 7(PTK7),and mechanical forces.This is demonstrated in vitro through stretch assays and in vivo via a mechanical loading experiment.Further in vitro analysis shows that GPR133/ADGRD1-mediated osteoblast differentiation is driven by cAMP-dependent activation of theβ-catenin signaling pathway.Activation of GPR133/ADGRD1 with the receptor-specific ligand AP-970/43482503(AP503)enhances osteoblast function and differentiation,both in vitro and in vivo,significantly alleviating osteoporosis in a mouse ovariectomy model.These findings position GPR133/ADGRD1 as a promising therapeutic target for osteoporosis and other diseases characterized by reduced bone mass.展开更多
Objective： To assess the effect of puerarin, a natural fiavonoid found in Chinese Pueraria Lobata （Wild.） Ohwi, on promotion of new bone formation. Methods： Osteoblasts isolated from calvarial of newborn rats were...Objective： To assess the effect of puerarin, a natural fiavonoid found in Chinese Pueraria Lobata （Wild.） Ohwi, on promotion of new bone formation. Methods： Osteoblasts isolated from calvarial of newborn rats were cultured in vitro in the presence of puerarin at various concentrations. The viability of osteoblasts and alkaline phosphotase activity and mineral node formation were determined. In addition, osteoblasts seeded in the β -tricaclium phosphate scalfolds as bone substitute were implanted in rat dorsal muscles. Half of the recipient rats received intramuscular injection of pueradn at 10 mg/（kg.d） for 7 days. Osteogenesis was analyzed by examining the histology after 4 weeks of implantation. Results： The viability of osteoblasts treated with puerarin at either 40 or 80 umol/L was significantly higher than that of the control （P〈0.05 and P〈0.01, respectively）. Alkaline phosphatase and mineral modules were significantly increased in osteoblasts cultured with puerarin at 40 or 80 mol/L when compared with that of the untreated cells. The pueradn-treated rats had a higher rate of bone formation in the osteoblast implants than the control rats （6.35% vs. 1.32%, respectively, P〈0.05）. Conclusion： Puerarin was able to affect osteoblast proliferation and differentiation, and promote the new bone formation in osteoblast implants.展开更多
Objective：To review the recent developments in the mechanisms of epithelium sodium channels （ENaCs） induced bone formation and regulation.Data Sources：Studies written in English or Chinese were searched using Medl...Objective：To review the recent developments in the mechanisms of epithelium sodium channels （ENaCs） induced bone formation and regulation.Data Sources：Studies written in English or Chinese were searched using Medline,PubMed and the index of Chinese-language literature with time restriction from 2005 to 2014.Keywords included ENaC,bone,bone formation,osteonecrosis,estrogen,and osteoporosis.Data from published articles about the structure of ENaC,mechanism of ENaC in bone formation in recent domestic and foreign literature were selected.Study Selection：Abstract and full text of all studies were required to obtain.Studies those were not accessible and those did not focus on the keywords were excluded.Results：ENaCs are tripolymer ion channels which are assembled from homologous α,β,and γ subunits.Crystal structure of ENaCs suggests that ENaC has a central ion-channel located in the central symmetry axis of the three subunits.ENaCs are protease sensitive channels whose iron-channel activity is regulated by the proteolytic reaction.Channel opening probability of ENaCs is regulated by proteinases,mechanical force,and shear stress.Several molecules are involved in regulation of ENaCs in bone formation,including nitride oxide synthases,voltage-sensitive calcium channels,and cyclooxygenase-2.Conclusion：The pathway of ENaC involved in shear stress has an effect on stimulating osteoblasts even bone formation by estrogen interference.展开更多
It has been well recognized that the development and use of artificial materials with high osteogenic ability is one of the most promising means to replace bone grafting that has exhibited various negative effects.The...It has been well recognized that the development and use of artificial materials with high osteogenic ability is one of the most promising means to replace bone grafting that has exhibited various negative effects.The biomimetic features and unique physiochemical properties of nanomaterials play important roles in stimulating cellular functions and guiding tissue regeneration.But efficacy degree of some nanomaterials to promote specific tissue formation is still not clear.We hereby comparatively studied the osteogenic ability of our treated multiwalled carbon nanotubes(MCNTs)and the main inorganic mineral component of natural bone,nano-hydroxyapatite(nHA)in the same system,and tried to tell the related mechanism.In vitro culture of human adiposederived mesenchymal stem cells(HASCs)on the MCNTs and nHA demonstrated that although there was no significant difference in the cell adhesion amount between on the MCNTs and nHA,the cell attachment strength and proliferation on the MCNTs were better.Most importantly,the MCNTs could induce osteogenic differentiation of the HASCs better than the nHA,the possible mechanism of which was found to be that the MCNTs could activate Notch involved signaling pathways by concentrating more proteins,including specific bone-inducing ones.Moreover,the MCNTs could induce ectopic bone formation in vivo while the nHA could not,which might be because MCNTs could stimulate inducible cells in tissues to form inductive bone better than nHA by concentrating more proteins including specific bone-inducing ones secreted from M2 macrophages.Therefore,MCNTs might be more effective materials for accelerating bone formation even than nHA.展开更多
Dental implantation is an effective standard treatment modality to restore missing teeth and maxillofacial defects. However, in diabetics there is an increased risk for implant failure due to impaired peri-implant oss...Dental implantation is an effective standard treatment modality to restore missing teeth and maxillofacial defects. However, in diabetics there is an increased risk for implant failure due to impaired peri-implant osseous healing. Early topical insulin treat- ment was recently shown to normalize diabetic bone healing by rectifying impairments in osteoblastic activities. In this study, insulin/poly(lactic-co-glycolic acid) (PLGA) microspheres were prepared by a double-emulsion solvent evaporation method. Microspheres were then incorporated in fibrin gel to develop a local drug delivery system for diabetic patients requiring im- plant treatment. In vitro release of insulin from fibrin gel loaded with these microspheres was assessed, and sustained prolonged insulin release over 21 days ascertained. To assess the bioactivity of released insulin and determine whether slow release might improve impaired diabetic bone formation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), alkaline phosphatase (ALP) activity, mineralized nodule formation, and ELISA (enzyme-linked immunosorbent assay) assays were performed. The insulin released from the drug delivery system stimulated cell growth in previously inhibited cells, and ameliorated the impaired bone-forming ability of human MG-63 cells under high glucose conditions. Fibrin gel loaded with insulin/PLGA microspheres shows potential for improving peri-implant bone formation in diabetic patients.展开更多
Osseous reconstruction of large bone defects remains a challenge in oral and maxillofacial surgery.In addition to autogenous bone grafts,which despite potential donor-site mobility still represent the gold standard in...Osseous reconstruction of large bone defects remains a challenge in oral and maxillofacial surgery.In addition to autogenous bone grafts,which despite potential donor-site mobility still represent the gold standard in reconstructive surgery,many studies have investigated less invasive alternatives such as in vitro cultivation techniques.This study compared different types of seeding techniques on pureβ-tricalcium phosphate scaffolds in terms of bone formation and ceramic resorption in vivo.Cylindrical scaffolds loaded with autologous cancellous bone,venous blood,bone marrow aspirate concentrate or extracorporeal in vitro cultivated bone marrow stromal cells were cultured in sheep on a perforator vessel of the musculus latissimus dorsi over a 6-month period.Histological and histomorphometric analyses revealed that scaffolds loaded with cancellous bone were superior at promoting heterotopic bone formation and ceramic degradation,with autogenous bone and bone marrow aspirate concentrate inducing in vivo formation of vital bone tissue.These results confirm that autologous bone constitutes the preferred source of osteoinductive and osteogenic material that can reliably induce heterotopic bone formation in vivo.展开更多
JMJD3(KDM6B)is an H3K27me3 demethylase and counteracts polycomb-mediated transcription repression.However,the function of JMJD3 in vivo is not well understood.Here we show that JMJD3 is highly expressed in cells of th...JMJD3(KDM6B)is an H3K27me3 demethylase and counteracts polycomb-mediated transcription repression.However,the function of JMJD3 in vivo is not well understood.Here we show that JMJD3 is highly expressed in cells of the chondrocyte lineage,especially in prehypertrophic and hypertrophic chondrocytes,during endochondral ossification.Homozygous deletion of Jmjd3 results in severely decreased proliferation and delayed hypertrophy of chondrocytes,and thereby marked retardation of endochondral ossification in mice.Genetically,JMJD3 associates with RUNX2 to promote proliferation and hypertrophy of chondrocytes.Biochemically,JMJD3 associates with and enhances RUNX2 activity by derepression of Runx2 and Ihh transcription throughits H3K27me3 demethylase activity.These results demonstrate that JMJD3 is a key epigenetic regulator in the process of cartilage maturation during endochondral bone formation.展开更多
Background A practical problem impeding clinical translation is the limited bone formation seen in artificial bone grafts.Low-pressure/vacuum seeding and dynamic culturing in bioreactors have led to a greater penetrat...Background A practical problem impeding clinical translation is the limited bone formation seen in artificial bone grafts.Low-pressure/vacuum seeding and dynamic culturing in bioreactors have led to a greater penetration into the scaffolds,enhanced production of bone marrow cells,and improved tissue-engineered bone formation.The goal of this study was to promote more extensive bone formation in the composites of porous ceramics and bone marrow stromal cells （BMSCs）.Methods BMSCs/β-tricalcium phosphate （β-TCP） composites were subcultured for 2 weeks and then subcutaneously implanted into syngeneic rats that were split into a low-intensity pulsed ultrasound （LIPUS） treatment group and a control group.These implants were harvested at 5,10,25,and 50 days after implantation.The samples were then biomechanically tested and analyzed for alkaline phosphate （ALP） activity and osteocalcin （OCN） content and were also observed by light microscopy.Results The levels of ALP activity and OCN content in the composites were significantly higher in the LIPUS group than in the control group.Histomorphometric analysis revealed a greater degree of soft tissue repair,increased blood flow,better angiogenesis,and more extensive bone formation in the LIPUS groups than in the controls.No significant difference in the compressive strength was found between the two groups.Conclusion LIPUS treatment appears to enhance bone formation and angiogenesis in the BMSCs/β3-TCP composites.展开更多
基金supported by the 2024 scientific promotion program funded by Jeju National University.
文摘Objective:To investigate the osteogenic effects of polyphenol-rich extracts from Wisteria floribunda(Willd.)DC.(W.floribunda)flowers and elucidate the underlying mechanisms.Methods:Polyphenolic compounds of W.floribunda extracts were analyzed,including flavonoids and glucoside derivatives.Osteogenic activity was assessed in MC3T3-E1 preosteoblast cells by measurement of alkaline phosphatase(ALP)activity,alizarin red S staining,and the expression of osteogenic markers(RUNX2,SP7,and ALPL).In vivo effects were evaluated in zebrafish larvae by assessing skeletal development and expression of osteogenic genes(runx2a,sp7,and alpl).The role of mammalian target of rapamycin(mTOR)pathway was examined using rapamycin.Results:W.floribunda extracts significantly enhanced ALP activity,bone mineralization,and the expression of RUNX2,SP7,and ALPL in MC3T3-E1 cells.In zebrafish larvae,W.floribunda extracts improved vertebral mineralization and upregulated osteogenic genes.Mechanistically,the plant extract activated the mTOR pathway,and rapamycin treatment attenuated the extracts-induced ALP activity,mineralization,and vertebral formation in zebrafish,confirming mTOR involvement.Conclusions:W.floribunda extracts promote osteoblast differentiation and bone formation via mTOR pathway activation.These findings provide novel insights into the potential of W.floribunda extracts and support its further investigation as a natural therapeutic candidate for bone degenerative disorders such as osteoporosis.
基金supported by grants by NIH grant AR-044741(Y-PL) and R01DE023813 (Y-PL)
文摘INTRODUCTIONThe transforming growth factor-β （TGF-β） superfamily com- prises TGF-βs, Activin, bone morphogenetic proteins （BMPs） and other related proteins. TGF-β superfamily members act through a heteromeric receptor complex,, comprised of type I and type II receptors at the cell surface that transduce intracellular signals via Smad complex or mitogen-activated protein kinase （MAPK） cascade.
文摘Transforming growth factor-beta（TGF-β）/bone morphogenetic protein（BMP） plays a fundamental role in the regulation of bone organogenesis through the activation of receptor serine/threonine kinases. Perturbations of TGF-β/BMP activity are almost invariably linked to a wide variety of clinical outcomes, i.e., skeletal, extra skeletal anomalies, autoimmune, cancer, and cardiovascular diseases. Phosphorylation of TGF-β（I/II） or BMP receptors activates intracellular downstream Smads, the transducer of TGF-β/BMP signals. This signaling is modulated by various factors and pathways, including transcription factor Runx2. The signaling network in skeletal development and bone formation is overwhelmingly complex and highly time and space specific.Additive, positive, negative, or synergistic effects are observed when TGF-β/BMP interacts with the pathways of MAPK, Wnt, Hedgehog（Hh）, Notch, Akt/m TOR, and mi RNA to regulate the effects of BMP-induced signaling in bone dynamics. Accumulating evidence indicates that Runx2 is the key integrator, whereas Hh is a possible modulator, mi RNAs are regulators, and b-catenin is a mediator/regulator within the extensive intracellular network. This review focuses on the activation of BMP signaling and interaction with other regulatory components and pathways highlighting the molecular mechanisms regarding TGF-β/BMP function and regulation that could allow understanding the complexity of bone tissue dynamics.
基金supported by the National Natural Science Foundation (NNSF) Key Research Program in Aging (91749204)National Natural Science Foundation of China (81871099, 31370958, 81701364, 81771491, 81501052)+1 种基金Shanghai Municipal Science and Technology Commission Key Program (15411950600, 18431902300)Municipal Human Resources Development Program for Outstanding Leaders in Medical Disciplines in Shanghai (2017BR011)
文摘RANKL signaling is essential for osteoclastogenesis. Its role in osteoblastic differentiation and bone formation is unknown. Here we demonstrate that RANK is expressed at an early stage of bone marrow mesenchymal stem cells(BMSCs) during osteogenic differentiation in both mice and human and decreased rapidly. RANKL signaling inhibits osteogenesis by promoting β-catenin degradation and inhibiting its synthesis. In contrast, RANKL signaling has no significant effects on adipogenesis of BMSCs.Interestingly, conditional knockout of rank in BMSCs with Prx1-Cre mice leads to a higher bone mass and increased trabecular bone formation independent of osteoclasts. In addition, rank: Prx1-Cre mice show resistance to ovariectomy-(OVX) induced bone loss. Thus, our results reveal that RANKL signaling regulates both osteoclasts and osteoblasts by inhibition of osteogenic differentiation of BMSCs and promotion of osteoclastogenesis.
文摘In the recent two decades, it has been well elucidated that receptor activator of nuclear factor-κB ligand （RANKL; also known as TNFSF11） binding to its receptor RANK （also known as TNFRSF11A） drives osteoclast development as the crucial signaling pathway.;However, accumulating evidence also implies that
基金supported by National Institutes of Health Grant DK083350 to M. W
文摘Lipoprotein receptor-related protein 6 （LRP6） plays a critical role in skeletal development and homeostasis in adults. However, the role of LRP6 in mesenchymal stem cells （MSCs）, skeletal stem cells that give rise to osteoblastic lineage, is unknown. In this study, we generated mice lacking LRP6 expression specifically in nestin＋ MSCs by crossing nestin-Cre mice with LRP6 flox mice and investigated the functional changes of bone marrow MSCs and skeletal alterations. Mice with LRP6 deletion in nestin＋ cells demonstrated reductions in body weight and body length at I and 3 months of age. Bone architecture measured by microCT （uCT） showed a significant reduction in bone mass in both trabecular and cortical bone of homozygous and heterozygous LRP6 mutant mice. A dramatic reduction in the numbers of osteoblasts but much less significant reduction in the numbers of osteoclasts was observed in the mutant mice. Osterix＋ osteoprogenitors and osteocalcin＋ osteoblasts significantly reduced at the secondary spongiosa area, but only moderately decreased at the primary spongiosa area in mutant mice. Bone marrow MSCs from the mutant mice showed decreased colony forming, cell viability and cell proliferation. Thus, LRP6 in bone marrow MSCs is essential for their survival and proliferation, and therefore, is a key positive regulator for bone formation during skeletal growth and remodeling.
基金supported by the CSC (China Scholarship Council)-QUT (Queensland University of Technology) PhD Scholarship awarded to Ms Rong Huangthe Institute of Health and Biomedical Innovation Early Career Researcher Scheme Funding awarded to Dr Yinghong Zhou
文摘The activation of M1 macrophages can be achieved by stimulating them with lipopolysaccharide （LPS） and interferon-γ （IFN-γ）. However, M1 can be found under physiological conditions without any pathological stimuli. This study aimed to understand the involvement of RANKL-induced M1 macrophages in bone formation compared with pathologically induced macrophages. Fischer rats were used to investigate macrophage distribution in normal and injured femoral condyles in vivo. Bone marrow-derived macrophages （BMDMs） were activated with LPS＋IFN-γ and RANKL to achieve M1 activation in vitro. Gene expression related to inflammation, osteoclastogenesis, angiogenesis, and migration was determined by reverse transcription-quantitative polymerase chain reaction （RT-qPCR） and fluorescence-activated cell sorting （FACS）. Tissue macrophages showed distinct expression patterns at different bone regions. RANKL was found in close proximity to inducible nitric oxide synthase-positive （iNOS＋） cells in vivo, suggesting an association between RANKL expression and iNOS＋ cells, especially in trabecular bone. RANKL-induced macrophages showed a different cytokine secretion profile compared with pathologically induced macrophages. Both osteoclasts and M1 macrophages peaked on day 7 during bone healing. RANKL could trigger Ml-like macrophages with properties that were different from those of LPS＋IFN-γ-induced macrophages. These RANKL-activated M1 macrophages were actively involved in bone formation.
文摘To study the new bone formation in the bone defect area after implantation, the tetracycline tracing method was used. The results show that new bone formed in 1 month, and the formation rate of new bone was very high (8.164μm/day),considerably faster than that of control groups (3.219μm/day).The new bone grew up quickly and β-TCP particles were surrounded by double fluorescence bands which became more obvious. The new bone formation rate was maximal at 2 months, and then gradually reduced. The rate was steady at 4 months, and then reduced to resembling as the normal physiologic metabolism of bone, which indicated the implanted materials were completely replaced by bone. Calcium phosphate materials had the ability of osteoconduction.
文摘Daily 20-mg and once-weekly 56.5-mg teriparatide（parathyroid hormone 1–34） treatment regimens increase bone mineral density（BMD） and prevent fractures, but changes in bone turnover markers differ between the two regimens. The aim of the present study was to explain changes in bone turnover markers using once-weekly teriparatide with a simulation model. Temporary increases in bone formation markers and subsequent decreases were observed during once-weekly teriparatide treatment for 72 weeks. These observations support the hypothesis that repeated weekly teriparatide administration stimulates bone remodeling, replacing old bone with new bone and leading to a reduction in the active remodeling surface. A simulation model was developed based on the iterative remodeling cycle that occurs on residual old bone. An increase in bone formation and a subsequent decrease were observed in the preliminary simulation. For each fitted time point, the predicted value was compared to the absolute values of the bone formation and resorption markers and lumbar BMD. The simulation model strongly matched actual changes in bone turnover markers and BMD. This simulation model indicates increased bone formation marker levels in the early stage and a subsequent decrease. It is therefore concluded that remodeling-based bone formation persisted during the entire treatment period with once-weekly teriparatide.
文摘The growth and enlargement of jaw cysts are associated with raised intracystic pressure and bone resorption surrounding the cysts.The major bone-resorbing cells are the osteoclasts.They are acting under the influence of local bone-resorbing factors: prostaglandins,proteinases and cytokines.It was found that positive pressure enhanced the expression of IL-1αmRNA and protein in epithelial cells of odontogenic keratocyst,and increased the secretion of matrix metalloproteinase and PGE2 in a co-culture of odontogenic keratocyst fibroblasts and epithelial cells.However,the signal intensities for IL-1α mRNA and protein in the epithelium were significantly decreased after marsupialization which relived intracystic pressure.Experimental study indicated that intermittent negative pressure could promote osteogenesis in human bone marrow-derived stroma cells(BMSCs) in vitro.We propose a hypothesis that bone formation around the cyst of the jaws would be stimulated by intracystic negative pressure.
基金Supported by the National Natural Science Foundation of China(82205105).
文摘Ankylosing spondylitis(AS)has a very high disability rate.How to effectively inhibit the formation of new bones has become a difficult point in clinical treatment.In recent years,research has shown that different treatment plans can have an impact on inhibiting new bone formation.In this paper,the different effects of new bone formation in the treatment of AS with traditional Chinese and Western medicine are systematically listed.
基金Supported by the National Natural Science Foundation of China(No.U24A6013,No.82274232 and No.82405121)Science and Technology Program Project of Guangdong Province-Guangdong Provincial Key Laboratory of Traditional Chinese Informatization(No.2021B1212040007)+2 种基金Basic and Applied Basic Research Fund of Guangdong Province(No.2022B1515120022)Construction Project of Guangdong Famous Traditional Chinese Medicine Inheritance Studio of ZHANG Rong-hua[Guangdong Traditional Chinese Medicine Letter(2023)No.108]China Association for Science and Technology(CAST)Young Talent Support Project Doctoral Student Special Program(CAST Office Letter[2024]No.92)。
文摘Objective To investigate the Wnt signaling pathway and miRNAs mechanism of extracts of Plastrum Testudinis(PT)in the treatment of osteoporosis(OP).Methods Thirty female Sprague Dawley rats were randomly divided into 5 groups by random number table method,including sham group,ovariectomized group(OVX),ovariectomized groups treated with high-,medium-,and low-dose PT(160,80,40 mg/kg per day,respectively),with 6 rats in each group.Except for the sham group,the other rats underwent bilateral ovariectomy to simulate OP and received PT by oral gavage for 10 consecutive weeks.After treatment,bone mineral density was measured by dual-energy X-ray absorptiometry;bone microstructure was analyzed by micro-computed tomography and hematoxylin and eosin staining;and the expressions of osteogenic differentiation-related factors were detected by immunochemistry,Western blot,and quantitative polymerase chain reaction.In addition,Dickkopf-1(Dkk-1)was used to inhibit the Wnt signaling pathway in bone marrow mesenchymal stem cells(BMSCs)and miRNA overexpression was used to evaluate the effect of miR-214 on the osteogenic differentiation of BMSCs.Subsequently,PT extract was used to rescue the effects of Dkk-1 and miR-214,and its impacts on the osteogenic differentiation-related factors of BMSCs were evaluated.
基金the German Research Foundation through CRC1052,CRC1423 and FOR2149(project numbers 209933838,421152132 and 246212759,respectively)to I.Lsupported by the German Research Foundation(project number 455890087)+2 种基金supported by the New Cornerstone Science Foundation(J.-P.S.)supported by Noncommunicable Chronic Diseases-National Science and Technology Major Project(2024ZD0523100 to J.-P.S.)National Natural Science Foundation of China(32361163612 to J.-P.S.).
文摘Osteoporosis represents an increasing health and socioeconomic burden on aging societies.Current therapeutic options often come with potentially severe side effects or lack long-term efficacy,highlighting the urgent need for more effective treatments.Identifying novel drug targets requires a thorough understanding of their physiological roles.Genome-wide association studies in humans have linked gene variants of the adhesion G protein-coupled receptor 133(GPR133/ADGRD1)to variations in bone mineral density and body height.In this study,we explore the impact of GPR133/ADGRD1 on osteoblast differentiation and function.Constitutive and osteoblast-specific knockouts of Gpr133/Adgrd1 in mice lead to reduced cortical bone mass and trabecularization in the femurs and vertebrae—features characteristic of osteoporosis.This osteopenic phenotype in receptor-deficient mice is caused by impaired osteoblast function,which,in turn,promotes increased osteoclast activity.At the molecular level,GPR133/ADGRD1 regulates osteoblast function and differentiation through a combined activation mechanism involving interaction with its endogenous ligand,protein tyrosine kinase 7(PTK7),and mechanical forces.This is demonstrated in vitro through stretch assays and in vivo via a mechanical loading experiment.Further in vitro analysis shows that GPR133/ADGRD1-mediated osteoblast differentiation is driven by cAMP-dependent activation of theβ-catenin signaling pathway.Activation of GPR133/ADGRD1 with the receptor-specific ligand AP-970/43482503(AP503)enhances osteoblast function and differentiation,both in vitro and in vivo,significantly alleviating osteoporosis in a mouse ovariectomy model.These findings position GPR133/ADGRD1 as a promising therapeutic target for osteoporosis and other diseases characterized by reduced bone mass.
基金Supported by the Doctoral Fund of Ministry of Education of China(No.20070698083)
文摘Objective： To assess the effect of puerarin, a natural fiavonoid found in Chinese Pueraria Lobata （Wild.） Ohwi, on promotion of new bone formation. Methods： Osteoblasts isolated from calvarial of newborn rats were cultured in vitro in the presence of puerarin at various concentrations. The viability of osteoblasts and alkaline phosphotase activity and mineral node formation were determined. In addition, osteoblasts seeded in the β -tricaclium phosphate scalfolds as bone substitute were implanted in rat dorsal muscles. Half of the recipient rats received intramuscular injection of pueradn at 10 mg/（kg.d） for 7 days. Osteogenesis was analyzed by examining the histology after 4 weeks of implantation. Results： The viability of osteoblasts treated with puerarin at either 40 or 80 umol/L was significantly higher than that of the control （P〈0.05 and P〈0.01, respectively）. Alkaline phosphatase and mineral modules were significantly increased in osteoblasts cultured with puerarin at 40 or 80 mol/L when compared with that of the untreated cells. The pueradn-treated rats had a higher rate of bone formation in the osteoblast implants than the control rats （6.35% vs. 1.32%, respectively, P〈0.05）. Conclusion： Puerarin was able to affect osteoblast proliferation and differentiation, and promote the new bone formation in osteoblast implants.
基金a grant of the National Natural Science Foundation of China
文摘Objective：To review the recent developments in the mechanisms of epithelium sodium channels （ENaCs） induced bone formation and regulation.Data Sources：Studies written in English or Chinese were searched using Medline,PubMed and the index of Chinese-language literature with time restriction from 2005 to 2014.Keywords included ENaC,bone,bone formation,osteonecrosis,estrogen,and osteoporosis.Data from published articles about the structure of ENaC,mechanism of ENaC in bone formation in recent domestic and foreign literature were selected.Study Selection：Abstract and full text of all studies were required to obtain.Studies those were not accessible and those did not focus on the keywords were excluded.Results：ENaCs are tripolymer ion channels which are assembled from homologous α,β,and γ subunits.Crystal structure of ENaCs suggests that ENaC has a central ion-channel located in the central symmetry axis of the three subunits.ENaCs are protease sensitive channels whose iron-channel activity is regulated by the proteolytic reaction.Channel opening probability of ENaCs is regulated by proteinases,mechanical force,and shear stress.Several molecules are involved in regulation of ENaCs in bone formation,including nitride oxide synthases,voltage-sensitive calcium channels,and cyclooxygenase-2.Conclusion：The pathway of ENaC involved in shear stress has an effect on stimulating osteoblasts even bone formation by estrogen interference.
基金The authors acknowledge the financial supports from the National Natural Science Foundation of China(No.31771042)Fok Ying Tung Education Foundation(No.141039)+1 种基金State Key Laboratory of New Ceramic and Fine Processing Tsinghua University,Fund of Key Laboratory of Advanced Materials of Ministry of Education(No.2020AML10)International Joint Research Center of Aerospace Biotechnology and Medical Engineering,Ministry of Science and Technology of China,and the 111 Project(No.B13003).
文摘It has been well recognized that the development and use of artificial materials with high osteogenic ability is one of the most promising means to replace bone grafting that has exhibited various negative effects.The biomimetic features and unique physiochemical properties of nanomaterials play important roles in stimulating cellular functions and guiding tissue regeneration.But efficacy degree of some nanomaterials to promote specific tissue formation is still not clear.We hereby comparatively studied the osteogenic ability of our treated multiwalled carbon nanotubes(MCNTs)and the main inorganic mineral component of natural bone,nano-hydroxyapatite(nHA)in the same system,and tried to tell the related mechanism.In vitro culture of human adiposederived mesenchymal stem cells(HASCs)on the MCNTs and nHA demonstrated that although there was no significant difference in the cell adhesion amount between on the MCNTs and nHA,the cell attachment strength and proliferation on the MCNTs were better.Most importantly,the MCNTs could induce osteogenic differentiation of the HASCs better than the nHA,the possible mechanism of which was found to be that the MCNTs could activate Notch involved signaling pathways by concentrating more proteins,including specific bone-inducing ones.Moreover,the MCNTs could induce ectopic bone formation in vivo while the nHA could not,which might be because MCNTs could stimulate inducible cells in tissues to form inductive bone better than nHA by concentrating more proteins including specific bone-inducing ones secreted from M2 macrophages.Therefore,MCNTs might be more effective materials for accelerating bone formation even than nHA.
文摘Dental implantation is an effective standard treatment modality to restore missing teeth and maxillofacial defects. However, in diabetics there is an increased risk for implant failure due to impaired peri-implant osseous healing. Early topical insulin treat- ment was recently shown to normalize diabetic bone healing by rectifying impairments in osteoblastic activities. In this study, insulin/poly(lactic-co-glycolic acid) (PLGA) microspheres were prepared by a double-emulsion solvent evaporation method. Microspheres were then incorporated in fibrin gel to develop a local drug delivery system for diabetic patients requiring im- plant treatment. In vitro release of insulin from fibrin gel loaded with these microspheres was assessed, and sustained prolonged insulin release over 21 days ascertained. To assess the bioactivity of released insulin and determine whether slow release might improve impaired diabetic bone formation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), alkaline phosphatase (ALP) activity, mineralized nodule formation, and ELISA (enzyme-linked immunosorbent assay) assays were performed. The insulin released from the drug delivery system stimulated cell growth in previously inhibited cells, and ameliorated the impaired bone-forming ability of human MG-63 cells under high glucose conditions. Fibrin gel loaded with insulin/PLGA microspheres shows potential for improving peri-implant bone formation in diabetic patients.
文摘Osseous reconstruction of large bone defects remains a challenge in oral and maxillofacial surgery.In addition to autogenous bone grafts,which despite potential donor-site mobility still represent the gold standard in reconstructive surgery,many studies have investigated less invasive alternatives such as in vitro cultivation techniques.This study compared different types of seeding techniques on pureβ-tricalcium phosphate scaffolds in terms of bone formation and ceramic resorption in vivo.Cylindrical scaffolds loaded with autologous cancellous bone,venous blood,bone marrow aspirate concentrate or extracorporeal in vitro cultivated bone marrow stromal cells were cultured in sheep on a perforator vessel of the musculus latissimus dorsi over a 6-month period.Histological and histomorphometric analyses revealed that scaffolds loaded with cancellous bone were superior at promoting heterotopic bone formation and ceramic degradation,with autogenous bone and bone marrow aspirate concentrate inducing in vivo formation of vital bone tissue.These results confirm that autologous bone constitutes the preferred source of osteoinductive and osteogenic material that can reliably induce heterotopic bone formation in vivo.
基金This work was supported by the National Natural Science Foundation of China(91219304)National Basic Research Program of China(2010CB529705,2011CB510103,2014CB943100)the Council of Shanghai Municipal Government for Science and Technology.
文摘JMJD3(KDM6B)is an H3K27me3 demethylase and counteracts polycomb-mediated transcription repression.However,the function of JMJD3 in vivo is not well understood.Here we show that JMJD3 is highly expressed in cells of the chondrocyte lineage,especially in prehypertrophic and hypertrophic chondrocytes,during endochondral ossification.Homozygous deletion of Jmjd3 results in severely decreased proliferation and delayed hypertrophy of chondrocytes,and thereby marked retardation of endochondral ossification in mice.Genetically,JMJD3 associates with RUNX2 to promote proliferation and hypertrophy of chondrocytes.Biochemically,JMJD3 associates with and enhances RUNX2 activity by derepression of Runx2 and Ihh transcription throughits H3K27me3 demethylase activity.These results demonstrate that JMJD3 is a key epigenetic regulator in the process of cartilage maturation during endochondral bone formation.
基金the National Natural Science Foundation of China，the Natural Science Foundation of Beijing,China
文摘Background A practical problem impeding clinical translation is the limited bone formation seen in artificial bone grafts.Low-pressure/vacuum seeding and dynamic culturing in bioreactors have led to a greater penetration into the scaffolds,enhanced production of bone marrow cells,and improved tissue-engineered bone formation.The goal of this study was to promote more extensive bone formation in the composites of porous ceramics and bone marrow stromal cells （BMSCs）.Methods BMSCs/β-tricalcium phosphate （β-TCP） composites were subcultured for 2 weeks and then subcutaneously implanted into syngeneic rats that were split into a low-intensity pulsed ultrasound （LIPUS） treatment group and a control group.These implants were harvested at 5,10,25,and 50 days after implantation.The samples were then biomechanically tested and analyzed for alkaline phosphate （ALP） activity and osteocalcin （OCN） content and were also observed by light microscopy.Results The levels of ALP activity and OCN content in the composites were significantly higher in the LIPUS group than in the control group.Histomorphometric analysis revealed a greater degree of soft tissue repair,increased blood flow,better angiogenesis,and more extensive bone formation in the LIPUS groups than in the controls.No significant difference in the compressive strength was found between the two groups.Conclusion LIPUS treatment appears to enhance bone formation and angiogenesis in the BMSCs/β3-TCP composites.
