Genetic studies have revealed a critical role of Distal-homeobox (Dlx) genes in bone formation,and our previous study showed that Dlx2 overexpressing in neural crest cells leads to profound abnormalities of the cranio...Genetic studies have revealed a critical role of Distal-homeobox (Dlx) genes in bone formation,and our previous study showed that Dlx2 overexpressing in neural crest cells leads to profound abnormalities of the craniofacial tissues.The aim of this study was to investigate the role and the underlying molecular mechanisms of Dlx2 in osteogenic differentiation of mouse bone marrow stromal cells (BMSCs) and pre-osteoblast MC3T3-E1 cells.Initially,we observed upregulation of Dlx2 during the early osteogenesis in BMSCs and MC3T3-E1 cells.Moreover,Dlx2 overexpression enhanced alkaline phosphatase (ALP) activity and extracellular matrix mineralization in BMSCs and MC3T3-E1 cell line.In addition,micro-CT of implanted tissues in nude mice confirmed that Dlx2 overexpression in BMSCs promoted bone formation in vivo.Unexpectedly,Dlx2 overexpression had little impact on the expression level of the pivotal osteogenic transcription factors Runx2,Dlx5,Msx2,and Osterix,but led to upregulation of Alp and Osteocalcin (OCN),both of which play critical roles in promoting osteoblast maturation.Importantly,luciferase analysis showed that Dlx2 overexpression stimulated both OCN and Alp promoter activity.Through chromatin-immunoprecipitation assay and site-directed mutagenesis analysis,we provide molecular evidence that Dlx2 transactivates OCN and Alp expression by directly binding to the Dlx2-response cis-acting elements in the promoter of the two genes.Based on these findings,we demonstrate that Dlx2 overexpression enhances osteogenic differentiation in vitro and accelerates bone formation in vivo via direct upregulation of the OCN and Alp gene,suggesting that Dlx2 plays a crucial role in osteogenic differentiation and bone formation.展开更多
The study presents a comprehensive coupled thermo-bio-chemo-hydraulic(T-BCH)modeling framework for stabilizing soils using microbially induced calcite precipitation(MICP).The numerical model considers relevant multiph...The study presents a comprehensive coupled thermo-bio-chemo-hydraulic(T-BCH)modeling framework for stabilizing soils using microbially induced calcite precipitation(MICP).The numerical model considers relevant multiphysics involved in MICP,such as bacterial ureolytic activities,biochemical reactions,multiphase and multicomponent transport,and alteration of the porosity and permeability.The model incorporates multiphysical coupling effects through well-established constitutive relations that connect parameters and variables from different physical fields.It was implemented in the open-source finite element code OpenGeoSys(OGS),and a semi-staggered solution strategy was designed to solve the couplings,allowing for flexible model settings.Therefore,the developed model can be easily adapted to simulate MICP applications in different scenarios.The numerical model was employed to analyze the effect of various factors,including temperature,injection strategies,and application scales.Besides,a TBCH modeling study was conducted on the laboratory-scale domain to analyze the effects of temperature on urease activity and precipitated calcium carbonate.To understand the scale dependency of MICP treatment,a large-scale heterogeneous domain was subjected to variable biochemical injection strategies.The simulations conducted at the field-scale guided the selection of an injection strategy to achieve the desired type and amount of precipitation.Additionally,the study emphasized the potential of numerical models as reliable tools for optimizing future developments in field-scale MICP treatment.The present study demonstrates the potential of this numerical framework for designing and optimizing the MICP applications in laboratory-,prototype-,and field-scale scenarios.展开更多
目的比较8周抗阻联合高强度间歇同期训练、单独高强度间歇训练和单独抗阻训练对男青年骨密度、肌肉适能以及血清肌骨共调节因子骨钙素和鸢尾素水平的影响。方法选取39名男青年,随机分为抗阻训练(RT)、高强度间歇训练(HIIT)和抗阻联合高...目的比较8周抗阻联合高强度间歇同期训练、单独高强度间歇训练和单独抗阻训练对男青年骨密度、肌肉适能以及血清肌骨共调节因子骨钙素和鸢尾素水平的影响。方法选取39名男青年,随机分为抗阻训练(RT)、高强度间歇训练(HIIT)和抗阻联合高强度间歇同期训练(CT)三组后,分别进行为期8周的运动干预。分别在干预前和干预后48 h测试受试者的骨密度(bone mineral density,BMD)、体成分、最大摄氧量、肌肉力量、爆发力以及血清骨钙素和鸢尾素水平。结果三种运动干预均能显著提高男青年的瘦体重,但只有HIIT(P<0.01)和CT干预(P<0.05)能显著降低男青年的体脂率;三种运动干预均能显著提高男青年的股骨BMD,但只有HIIT(P<0.05)和RT(P<0.05)干预能显著提高男青年的腰椎BMD;RT和CT干预能显著提升男青年的卧推、硬拉、划船、深蹲的最大力量(P<0.01)和反向纵跳高度(P<0.01),而HIIT干预只能显著提升深蹲的最大力量(P<0.01);三种运动干预均能显著提高男青年的血清鸢尾素和骨钙素水平。结论三种运动干预均能增加男青年的瘦体重、股骨BMD以及血清肌骨调节因子鸢尾素和骨钙素水平,但CT对腰椎BMD的提升效果小于HIIT和RT,而RT和CT对肌肉力量和爆发力的提升效果大于HIIT。展开更多
基金supported by grant (81771036) from National Natural Science Foundation of China (to S.G.S.)grant (81741028) from National Natural Science Foundation of China (to J.D.)grant (17410710500) Shanghai International Scientific and Technological Cooperation Projects Laser Micromachine and Vascularization of TCP/PCL Scaffolds (to W.Z.)
文摘Genetic studies have revealed a critical role of Distal-homeobox (Dlx) genes in bone formation,and our previous study showed that Dlx2 overexpressing in neural crest cells leads to profound abnormalities of the craniofacial tissues.The aim of this study was to investigate the role and the underlying molecular mechanisms of Dlx2 in osteogenic differentiation of mouse bone marrow stromal cells (BMSCs) and pre-osteoblast MC3T3-E1 cells.Initially,we observed upregulation of Dlx2 during the early osteogenesis in BMSCs and MC3T3-E1 cells.Moreover,Dlx2 overexpression enhanced alkaline phosphatase (ALP) activity and extracellular matrix mineralization in BMSCs and MC3T3-E1 cell line.In addition,micro-CT of implanted tissues in nude mice confirmed that Dlx2 overexpression in BMSCs promoted bone formation in vivo.Unexpectedly,Dlx2 overexpression had little impact on the expression level of the pivotal osteogenic transcription factors Runx2,Dlx5,Msx2,and Osterix,but led to upregulation of Alp and Osteocalcin (OCN),both of which play critical roles in promoting osteoblast maturation.Importantly,luciferase analysis showed that Dlx2 overexpression stimulated both OCN and Alp promoter activity.Through chromatin-immunoprecipitation assay and site-directed mutagenesis analysis,we provide molecular evidence that Dlx2 transactivates OCN and Alp expression by directly binding to the Dlx2-response cis-acting elements in the promoter of the two genes.Based on these findings,we demonstrate that Dlx2 overexpression enhances osteogenic differentiation in vitro and accelerates bone formation in vivo via direct upregulation of the OCN and Alp gene,suggesting that Dlx2 plays a crucial role in osteogenic differentiation and bone formation.
基金support from the OpenGeoSys communitypartially funded by the Prime Minister Research Fellowship,Ministry of Education,Government of India with the project number SB21221901CEPMRF008347.
文摘The study presents a comprehensive coupled thermo-bio-chemo-hydraulic(T-BCH)modeling framework for stabilizing soils using microbially induced calcite precipitation(MICP).The numerical model considers relevant multiphysics involved in MICP,such as bacterial ureolytic activities,biochemical reactions,multiphase and multicomponent transport,and alteration of the porosity and permeability.The model incorporates multiphysical coupling effects through well-established constitutive relations that connect parameters and variables from different physical fields.It was implemented in the open-source finite element code OpenGeoSys(OGS),and a semi-staggered solution strategy was designed to solve the couplings,allowing for flexible model settings.Therefore,the developed model can be easily adapted to simulate MICP applications in different scenarios.The numerical model was employed to analyze the effect of various factors,including temperature,injection strategies,and application scales.Besides,a TBCH modeling study was conducted on the laboratory-scale domain to analyze the effects of temperature on urease activity and precipitated calcium carbonate.To understand the scale dependency of MICP treatment,a large-scale heterogeneous domain was subjected to variable biochemical injection strategies.The simulations conducted at the field-scale guided the selection of an injection strategy to achieve the desired type and amount of precipitation.Additionally,the study emphasized the potential of numerical models as reliable tools for optimizing future developments in field-scale MICP treatment.The present study demonstrates the potential of this numerical framework for designing and optimizing the MICP applications in laboratory-,prototype-,and field-scale scenarios.
文摘目的比较8周抗阻联合高强度间歇同期训练、单独高强度间歇训练和单独抗阻训练对男青年骨密度、肌肉适能以及血清肌骨共调节因子骨钙素和鸢尾素水平的影响。方法选取39名男青年,随机分为抗阻训练(RT)、高强度间歇训练(HIIT)和抗阻联合高强度间歇同期训练(CT)三组后,分别进行为期8周的运动干预。分别在干预前和干预后48 h测试受试者的骨密度(bone mineral density,BMD)、体成分、最大摄氧量、肌肉力量、爆发力以及血清骨钙素和鸢尾素水平。结果三种运动干预均能显著提高男青年的瘦体重,但只有HIIT(P<0.01)和CT干预(P<0.05)能显著降低男青年的体脂率;三种运动干预均能显著提高男青年的股骨BMD,但只有HIIT(P<0.05)和RT(P<0.05)干预能显著提高男青年的腰椎BMD;RT和CT干预能显著提升男青年的卧推、硬拉、划船、深蹲的最大力量(P<0.01)和反向纵跳高度(P<0.01),而HIIT干预只能显著提升深蹲的最大力量(P<0.01);三种运动干预均能显著提高男青年的血清鸢尾素和骨钙素水平。结论三种运动干预均能增加男青年的瘦体重、股骨BMD以及血清肌骨调节因子鸢尾素和骨钙素水平,但CT对腰椎BMD的提升效果小于HIIT和RT,而RT和CT对肌肉力量和爆发力的提升效果大于HIIT。
