Presently, there is a high paucity of bone grafts in the United States and worldwide. Regenerating bone is of prime concern due to the current demand of bone grafts and the increasing number of diseases causing bone l...Presently, there is a high paucity of bone grafts in the United States and worldwide. Regenerating bone is of prime concern due to the current demand of bone grafts and the increasing number of diseases causing bone loss. Autogenous bone is the present gold standard of bone regeneration. However, disadvantages like donor site morbidity and its decreased availability limit its use. Even allografts and synthetic grafting materials have their own limitations. As certain specific stem cells can be directed to differentiate into an osteoblastic lineage in the presence of growth factors(GFs), it makes stem cells the ideal agents for bone regeneration.Furthermore, platelet-rich plasma(PRP), which can be easily isolated from whole blood, is often used for bone regeneration, wound healing and bone defect repair. When stem cells are combined with PRP in the presence of GFs, they are able to promote osteogenesis. This review provides in-depth knowledge regarding the use of stem cells and PRP in vitro, in vivo and their application in clinical studies in the future.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
YAP（yes-associated protein） is a transcriptional factor that is negatively regulated by Hippo pathway, a conserved pathway for the development and size control of multiple organs. The exact function of YAP in bone h...YAP（yes-associated protein） is a transcriptional factor that is negatively regulated by Hippo pathway, a conserved pathway for the development and size control of multiple organs. The exact function of YAP in bone homeostasis remains controversial. Here we provide evidence for YAP＇s function in promoting osteogenesis, suppressing adipogenesis, and thus maintaining bone homeostasis.YAP is selectively expressed in osteoblast（OB）-lineage cells. Conditionally knocking out Yap in the OB lineage in mice reduces cell proliferation and OB differentiation and increases adipocyte formation, resulting in a trabecular bone loss. Mechanistically, YAP interacts with β-catenin and is necessary for maintenance of nuclear β-catenin level and Wnt/β-catenin signaling. Expression of β-catenin in YAP-deficient BMSCs（bone marrow stromal cells） diminishes the osteogenesis deficit. These results thus identify YAP-β-catenin as an important pathway for osteogenesis during adult bone remodeling and uncover a mechanism underlying YAP regulation of bone homeostasis.展开更多
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
OBJECTIVE： To summarize the biological characteristics of neural stem cells, and the separation, purification. differentiation and source of neural stem cells. DATA SOURCES ： An online search of Pubmed database was ...OBJECTIVE： To summarize the biological characteristics of neural stem cells, and the separation, purification. differentiation and source of neural stem cells. DATA SOURCES ： An online search of Pubmed database was undertaken to identify English articles about the growth of neural stem cells in vitro published from January 2000 to October 2006 by using the keywords of ＂neural stem cells, bone marrow mesenchymal stem cells （BMSCs）, umbilical cord blood stem cells, embryonic stem cells （ESC）, separation methods, neural growth factor＂. And relevant articles published in IEEE/IEE Electronic Library （IEL） database, Springer Link database and Kluwer Online Journals were also searched, Chinese relevant articles published between January 2000 to October 2006 were searched with the same keywords in Chinese in Chinese journal full-text database. STUDY SELECTION ： The articles were primarily screened, and then the full-texts were searched. Inclusive criteria： （1） Articles relevant to the biological characteristics and classification of neural stem cells; （2） Articles about the source, separation and differentiation of the ESCs, BMSCs and umbilical cord blood stem cells. The repetitive studies and reviews were excluded. DATA EXTRACTION ： Thirty articles were selected from 203 relevant articles according to the inclusive criteria Articles were excluded because of repetition and reviews. DATA SYNTHESES ： Neural stem cells have the ability of self-renewing and high differentiation, and they are obtained from ESCs, nerve tissue, nerve system, BMSCs and umbilical cord blood stem cells. ESCs can be separated by means of mechanical dissociation is better than that of the trypsin digestion, BMSCs by density gradient centrifuge separation, hemolysis, whole-blood culture, etc., and umbilical cord blood stem ceils by Ficoil density gradient centrifugation, hydroxyethyl starch （HES） centrifugation sedimentation, etc. Neural growth factor （NGF） and other factors play an important role in the gr展开更多
Objective:To investigate the effects of panax notoginseng saponins(PNS) on homing of C-kit+ bone mesenchymal stem cells(BMSCs) to the infarction heart.Methods:The acute myocardial infraction(AMI) model was established...Objective:To investigate the effects of panax notoginseng saponins(PNS) on homing of C-kit+ bone mesenchymal stem cells(BMSCs) to the infarction heart.Methods:The acute myocardial infraction(AMI) model was established in 140 Wistar rats,105 model rats survived after operation,and the model rats were randomly divided into five groups,21 rats in each group:Western medicine group mobilized by subcutaneous injection of human granuloctye colony stimulating factor(G-CSF) 50 μg·kg-1·d-1;sham operation group and a model group treated by subcutaneous injection of normal saline 50 μg·kg-1·d-1;Chinese medicine group mobilized by intraperitoneal injection of Xuesaitong(血塞通)(ingredients of PNS) 150 mg·kg-1·d-1;integrative medicine group mobilized by subcutaneous injection of G-CSF 50 μg·kg-1·d-1 and intraperitoneal injection of Xuesaitong 150 mg·kg-1·d-1.Except for the sham-operated group,each group was divided into three sub-groups by three time points of 1 d,7 d and 14 d.G-CSF was injected once a day for 7 d.Xuesaitong was injected once a day until the rats were killed.The flow cytometry was used for detection of C-kit + cells in the peripheral blood in different time points,and immunohistochemical method was used for detection of the changes of C-kit + cell and Ki-67+ cell numbers in the marginal zone of AMI.Results:Twenty-four hours after the operation,C-kit + cells had a slight increase in the model group compared with the sham operation group(P>0.05).The peripheral blood C-kit+ cells in the integrative group increased significantly compared with the other groups on 7 d and 14 d(all P<0.05).Meanwhile the expression of C-kit + cells and Ki-67+ cells in the marginal zone of AMI in the integrative group increased significantly compared with the Chinese medicine group,the western medicine group and the model group on 1 d,7 d and 14 d(all P<0.05),and the cells in the integrative group decreased significantly on 14 d compared with that on 7 d(P<0.05).Conclusion:PNS can cooperate with G-CSF to mobilize C-kit+展开更多
基金supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases,and National Institute of Dental and Craniofacial Research under Award Numbers AR061052,AR066101 and DE023105 to S.Y
文摘Presently, there is a high paucity of bone grafts in the United States and worldwide. Regenerating bone is of prime concern due to the current demand of bone grafts and the increasing number of diseases causing bone loss. Autogenous bone is the present gold standard of bone regeneration. However, disadvantages like donor site morbidity and its decreased availability limit its use. Even allografts and synthetic grafting materials have their own limitations. As certain specific stem cells can be directed to differentiate into an osteoblastic lineage in the presence of growth factors(GFs), it makes stem cells the ideal agents for bone regeneration.Furthermore, platelet-rich plasma(PRP), which can be easily isolated from whole blood, is often used for bone regeneration, wound healing and bone defect repair. When stem cells are combined with PRP in the presence of GFs, they are able to promote osteogenesis. This review provides in-depth knowledge regarding the use of stem cells and PRP in vitro, in vivo and their application in clinical studies in the future.
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.
基金supported in part by grants from the National Institutes of Health(AG051773)and VA(BX000838)
文摘YAP（yes-associated protein） is a transcriptional factor that is negatively regulated by Hippo pathway, a conserved pathway for the development and size control of multiple organs. The exact function of YAP in bone homeostasis remains controversial. Here we provide evidence for YAP＇s function in promoting osteogenesis, suppressing adipogenesis, and thus maintaining bone homeostasis.YAP is selectively expressed in osteoblast（OB）-lineage cells. Conditionally knocking out Yap in the OB lineage in mice reduces cell proliferation and OB differentiation and increases adipocyte formation, resulting in a trabecular bone loss. Mechanistically, YAP interacts with β-catenin and is necessary for maintenance of nuclear β-catenin level and Wnt/β-catenin signaling. Expression of β-catenin in YAP-deficient BMSCs（bone marrow stromal cells） diminishes the osteogenesis deficit. These results thus identify YAP-β-catenin as an important pathway for osteogenesis during adult bone remodeling and uncover a mechanism underlying YAP regulation of bone homeostasis.
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.
文摘OBJECTIVE： To summarize the biological characteristics of neural stem cells, and the separation, purification. differentiation and source of neural stem cells. DATA SOURCES ： An online search of Pubmed database was undertaken to identify English articles about the growth of neural stem cells in vitro published from January 2000 to October 2006 by using the keywords of ＂neural stem cells, bone marrow mesenchymal stem cells （BMSCs）, umbilical cord blood stem cells, embryonic stem cells （ESC）, separation methods, neural growth factor＂. And relevant articles published in IEEE/IEE Electronic Library （IEL） database, Springer Link database and Kluwer Online Journals were also searched, Chinese relevant articles published between January 2000 to October 2006 were searched with the same keywords in Chinese in Chinese journal full-text database. STUDY SELECTION ： The articles were primarily screened, and then the full-texts were searched. Inclusive criteria： （1） Articles relevant to the biological characteristics and classification of neural stem cells; （2） Articles about the source, separation and differentiation of the ESCs, BMSCs and umbilical cord blood stem cells. The repetitive studies and reviews were excluded. DATA EXTRACTION ： Thirty articles were selected from 203 relevant articles according to the inclusive criteria Articles were excluded because of repetition and reviews. DATA SYNTHESES ： Neural stem cells have the ability of self-renewing and high differentiation, and they are obtained from ESCs, nerve tissue, nerve system, BMSCs and umbilical cord blood stem cells. ESCs can be separated by means of mechanical dissociation is better than that of the trypsin digestion, BMSCs by density gradient centrifuge separation, hemolysis, whole-blood culture, etc., and umbilical cord blood stem ceils by Ficoil density gradient centrifugation, hydroxyethyl starch （HES） centrifugation sedimentation, etc. Neural growth factor （NGF） and other factors play an important role in the gr
基金supported by Important National Basic Research Program of China (973 Program, N0.2003CB517103)China Postdoctoral Foundation (No. 20070410129)
文摘Objective:To investigate the effects of panax notoginseng saponins(PNS) on homing of C-kit+ bone mesenchymal stem cells(BMSCs) to the infarction heart.Methods:The acute myocardial infraction(AMI) model was established in 140 Wistar rats,105 model rats survived after operation,and the model rats were randomly divided into five groups,21 rats in each group:Western medicine group mobilized by subcutaneous injection of human granuloctye colony stimulating factor(G-CSF) 50 μg·kg-1·d-1;sham operation group and a model group treated by subcutaneous injection of normal saline 50 μg·kg-1·d-1;Chinese medicine group mobilized by intraperitoneal injection of Xuesaitong(血塞通)(ingredients of PNS) 150 mg·kg-1·d-1;integrative medicine group mobilized by subcutaneous injection of G-CSF 50 μg·kg-1·d-1 and intraperitoneal injection of Xuesaitong 150 mg·kg-1·d-1.Except for the sham-operated group,each group was divided into three sub-groups by three time points of 1 d,7 d and 14 d.G-CSF was injected once a day for 7 d.Xuesaitong was injected once a day until the rats were killed.The flow cytometry was used for detection of C-kit + cells in the peripheral blood in different time points,and immunohistochemical method was used for detection of the changes of C-kit + cell and Ki-67+ cell numbers in the marginal zone of AMI.Results:Twenty-four hours after the operation,C-kit + cells had a slight increase in the model group compared with the sham operation group(P>0.05).The peripheral blood C-kit+ cells in the integrative group increased significantly compared with the other groups on 7 d and 14 d(all P<0.05).Meanwhile the expression of C-kit + cells and Ki-67+ cells in the marginal zone of AMI in the integrative group increased significantly compared with the Chinese medicine group,the western medicine group and the model group on 1 d,7 d and 14 d(all P<0.05),and the cells in the integrative group decreased significantly on 14 d compared with that on 7 d(P<0.05).Conclusion:PNS can cooperate with G-CSF to mobilize C-kit+
