Fibrotic remodeling of nucleus pulposus(NP)leads to structural and mechanical anomalies of intervertebral discs that prone to degeneration,leading to low back pain incidence and disability.Emergence of fibroblastic ce...Fibrotic remodeling of nucleus pulposus(NP)leads to structural and mechanical anomalies of intervertebral discs that prone to degeneration,leading to low back pain incidence and disability.Emergence of fibroblastic cells in disc degeneration has been reported,yet their nature and origin remain elusive.In this study,we performed an integrative analysis of multiple single-cell RNA sequencing datasets to interrogate the cellular heterogeneity and fibroblast-like entities in degenerative human NP specimens.We found that disc degeneration severity is associated with an enrichment of fibrocyte phenotype,characterized by CD45 and collagen I dual positivity,and expression of myofibroblast markerα-smooth muscle actin.Refined clustering and classification distinguished the fibrocyte-like populations as subtypes in the NP cells-and immunocytes-clusters,expressing disc degeneration markers HTRA1 and ANGPTL4 and genes related to response to TGF-β.In injury-induced mouse disc degeneration model,fibrocytes were found recruited into the NP undergoing fibrosis and adopted a myofibroblast phenotype.Depleting the fibrocytes in CD11b-DTR mice in which myeloid-derived lineages were ablated by diphtheria toxin could markedly attenuate fibrous modeling and myofibroblast formation in the NP of the degenerative discs,and prevent disc height loss and histomorphological abnormalities.Marker analysis supports that disc degeneration progression is dependent on a function of CD45^(+)COL1A1^(+)andαSMA^(+)cells.Our findings reveal that myeloid-derived fibrocytes play a pivotal role in NP fibrosis and may therefore be a target for modifying disc degeneration and promoting its repair.展开更多
The design of orthopedic biomaterials has gradually shifted from“immune-friendly”to“immunomodulatory,”in which the biomaterials are able to modulate the inflammatory response via macrophage polarization in a local...The design of orthopedic biomaterials has gradually shifted from“immune-friendly”to“immunomodulatory,”in which the biomaterials are able to modulate the inflammatory response via macrophage polarization in a local immune microenvironment that favors osteogenesis and implant-to-bone osseointegration.Despite the well-known effects of bioactive metallic ions on osteogenesis,how extracellular metallic ions manipulate immune cells in bone tissue microenvironments toward osteogenesis and subsequent bone formation has rarely been studied.Herein,we investigate the osteoimmunomodulatory effect of an extracellular bioactive cation(Mg^(2+))in the bone tissue microenvironment using custom-made poly lactic-co-glycolic acid(PLGA)/MgO-alendronate microspheres that endow controllable release of magnesium ions.The results suggest that the Mg^(2+)-controlled tissue microenvironment can effectively induce macrophage polarization from the M0 to M2 phenotype via the enhancement of anti-inflammatory(IL-10)and pro-osteogenic(BMP-2 and TGF-β1)cytokines production.It also generates a favorable osteoimmune microenvironment that facilitates the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells.The in vivo results further verify that a large amount of bony tissue,with comparable bone mineral density and mechanical properties,has been generated at an early post-surgical stage in rat intramedullary bone defect models.This study demonstrates that the concept of in situ immunomodulated osteogenesis can be realized in a controlled magnesium tissue microenvironment.展开更多
The fate of cells and subsequent bone regeneration is highly correlated with temporospatial coordination of chemical,biological,or physical cues within a local tissue microenvironment.Deeper understanding of how mamma...The fate of cells and subsequent bone regeneration is highly correlated with temporospatial coordination of chemical,biological,or physical cues within a local tissue microenvironment.Deeper understanding of how mammalian cells react to local tissue microenvironment is paramount important when designing next generation of biomaterials for tissue engineering.This study aims to investigate that the regulation of magnesium cationic(Mg^2+)tissue microenvironment is able to convince early-stage bone regeneration and its mechanism undergoes intramembranous ossification.It was discovered that moderate Mg^2+content niche(~4.11 mM)led to superior bone regeneration,while Mg^2+-free and strong Mg^2+content(~16.44 mM)discouraged cell adhesion,proliferation and osteogenic differentiation,thereby bone formation was rarely found.When magnesium ions diffused into free Mg zone from concentrated zone in late time point,new bone formation on free Mg zone became significant through intramembranous ossification.This study successfully demonstrates that magnesium cationic microenvironment serves as an effective biochemical cue and is able to modulate the process of bony tissue regeneration.The knowledge of how a Mg^2+cationic microenvironment intertwines with cells and subsequent bone formation gained from this study may provide a new insight to develop the next generation of tissuerepairing biomaterials.展开更多
Regardless of the advancement of synthetic bone substitutes,allograft-derived bone substitutes still dominate in the orthopaedic circle in the treatments of bone diseases.Nevertheless,the stringent devitalization proc...Regardless of the advancement of synthetic bone substitutes,allograft-derived bone substitutes still dominate in the orthopaedic circle in the treatments of bone diseases.Nevertheless,the stringent devitalization process jeopardizes their osseointegration with host bone and therefore prone to long-term failure.Hence,improving osseointegration and transplantation efficiency remains important.The alteration of bone tissue microenvironment(TME)to facilitate osseointegration has been generally recognized.However,the concept of exerting metal ionic cue in bone TME without compromising the mechanical properties of bone allograft is challenging.To address this concern,an interfacial tissue microenvironment with magnesium cationc cue was tailored onto the gamma-irradiated allograft bone using a customized magnesium-plasma surface treatment.The formation of the Mg cationic cue enriched interfacial tissue microenvironment on allograft bone was verified by the scanning ion-selective electrode technique.The cellular activities of human TERT-immortalized mesenchymal stem cells on the Mg-enriched grafts were notably upregulated.In the animal test,superior osseointegration between Mg-enriched graft and host bone was found,whereas poor integration was observed in the gamma-irradiated controls at 28 days post-operation.Furthermore,the bony in-growth appeared on magnesium-enriched allograft bone was significant higher.The mechanism possibly correlates to the up-regulation of integrin receptors in mesenchymal stem cells under modified bone TME that directly orchestrate the initial cell attachment and osteogenic differentiation of mesenchymal stem cells.Lastly,our findings demonstrate the significance of magnesium cation modified bone allograft that can potentially translate to various orthopaedic procedures requiring bone augmentation.展开更多
The authors regret a mistake of funding numbers in the Acknowledgment Section failed to be corrected during proof reading.Below is the corrected funding statement in Acknowledgment SECTION This work was supported by t...The authors regret a mistake of funding numbers in the Acknowledgment Section failed to be corrected during proof reading.Below is the corrected funding statement in Acknowledgment SECTION This work was supported by the National Natural Science Foundation of China(NSFC)(Nos.81902189,81772354,82002303,31570980),Clinical Innovation Research Program of Guangzhou Regenerative Medicine and Health Guangdong Laboratory(2018GZR0201002),National Key Research and Development Plan(2018YFC1105103).展开更多
基金jointly General Research Fund(17121619)of the Research Grant Council of Hong KongGuangdong Basic and Applied Basic Research Foundation(2024A1515010104 and 2023A1515220095)Scientific Research Foundation of Peking University Shenzhen Hospital(KYQD202100X)。
文摘Fibrotic remodeling of nucleus pulposus(NP)leads to structural and mechanical anomalies of intervertebral discs that prone to degeneration,leading to low back pain incidence and disability.Emergence of fibroblastic cells in disc degeneration has been reported,yet their nature and origin remain elusive.In this study,we performed an integrative analysis of multiple single-cell RNA sequencing datasets to interrogate the cellular heterogeneity and fibroblast-like entities in degenerative human NP specimens.We found that disc degeneration severity is associated with an enrichment of fibrocyte phenotype,characterized by CD45 and collagen I dual positivity,and expression of myofibroblast markerα-smooth muscle actin.Refined clustering and classification distinguished the fibrocyte-like populations as subtypes in the NP cells-and immunocytes-clusters,expressing disc degeneration markers HTRA1 and ANGPTL4 and genes related to response to TGF-β.In injury-induced mouse disc degeneration model,fibrocytes were found recruited into the NP undergoing fibrosis and adopted a myofibroblast phenotype.Depleting the fibrocytes in CD11b-DTR mice in which myeloid-derived lineages were ablated by diphtheria toxin could markedly attenuate fibrous modeling and myofibroblast formation in the NP of the degenerative discs,and prevent disc height loss and histomorphological abnormalities.Marker analysis supports that disc degeneration progression is dependent on a function of CD45^(+)COL1A1^(+)andαSMA^(+)cells.Our findings reveal that myeloid-derived fibrocytes play a pivotal role in NP fibrosis and may therefore be a target for modifying disc degeneration and promoting its repair.
基金supported by the National key R&D Program of China(2018YFC1105100)Guangdong Basic and Applied Basic Research Foundation(2019A1515111156)+8 种基金China Postdoctoral Science Foundation(2019M653060)NSFC/RGC Joint Research Scheme(No.N_HKU725/16)Health and Medical Research Fund(19180712)Shenzhen Science and Technology Funds(JSGG20180507183242702)Hong Kong Innovation Technology Fund(ITS/287/17 and ITS/405/18)Hong Kong Research Grant Council General Research Fund(No.17214516)the Science and Technology Commission of Shanghai Municipality(No.18410760600)International Partnership Program of Chinese Academy of Sciences(GJHZ1850)National Natural Science Foundation of China(81572113).
文摘The design of orthopedic biomaterials has gradually shifted from“immune-friendly”to“immunomodulatory,”in which the biomaterials are able to modulate the inflammatory response via macrophage polarization in a local immune microenvironment that favors osteogenesis and implant-to-bone osseointegration.Despite the well-known effects of bioactive metallic ions on osteogenesis,how extracellular metallic ions manipulate immune cells in bone tissue microenvironments toward osteogenesis and subsequent bone formation has rarely been studied.Herein,we investigate the osteoimmunomodulatory effect of an extracellular bioactive cation(Mg^(2+))in the bone tissue microenvironment using custom-made poly lactic-co-glycolic acid(PLGA)/MgO-alendronate microspheres that endow controllable release of magnesium ions.The results suggest that the Mg^(2+)-controlled tissue microenvironment can effectively induce macrophage polarization from the M0 to M2 phenotype via the enhancement of anti-inflammatory(IL-10)and pro-osteogenic(BMP-2 and TGF-β1)cytokines production.It also generates a favorable osteoimmune microenvironment that facilitates the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells.The in vivo results further verify that a large amount of bony tissue,with comparable bone mineral density and mechanical properties,has been generated at an early post-surgical stage in rat intramedullary bone defect models.This study demonstrates that the concept of in situ immunomodulated osteogenesis can be realized in a controlled magnesium tissue microenvironment.
基金This work was financially supported by the National key R&D Program of China(2018YFC1105100)Health and Medical Research Fund(19180712)+5 种基金Shenzhen Science and Technology Funds(JSGG20180507183242702)Hong Kong Innovation Technology Fund(ITS/287/17 and ITS/405/18)Hong Kong Research Grant Council General Research Fund(17214516)the Science and Technology Commission of Shanghai Municipality(18410760600)International Partnership Program of Chinese Academy of Sciences(GJHZ1850)National Natural Science Foundation of China(81572113).
文摘The fate of cells and subsequent bone regeneration is highly correlated with temporospatial coordination of chemical,biological,or physical cues within a local tissue microenvironment.Deeper understanding of how mammalian cells react to local tissue microenvironment is paramount important when designing next generation of biomaterials for tissue engineering.This study aims to investigate that the regulation of magnesium cationic(Mg^2+)tissue microenvironment is able to convince early-stage bone regeneration and its mechanism undergoes intramembranous ossification.It was discovered that moderate Mg^2+content niche(~4.11 mM)led to superior bone regeneration,while Mg^2+-free and strong Mg^2+content(~16.44 mM)discouraged cell adhesion,proliferation and osteogenic differentiation,thereby bone formation was rarely found.When magnesium ions diffused into free Mg zone from concentrated zone in late time point,new bone formation on free Mg zone became significant through intramembranous ossification.This study successfully demonstrates that magnesium cationic microenvironment serves as an effective biochemical cue and is able to modulate the process of bony tissue regeneration.The knowledge of how a Mg^2+cationic microenvironment intertwines with cells and subsequent bone formation gained from this study may provide a new insight to develop the next generation of tissuerepairing biomaterials.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.81902189,81772354,82002303,31570980)Clinical Innovation Research Program of Guangzhou Regenerative Medicine and Health Guangdong Laboratory(2018GZR0201001)+6 种基金National Key Research and Development Plan(2018YFC1105103)Research Grant Council General Research Funds(RGC GRF)(17214516)Shenzhen Science and Technology Innovation Funding(JCYJ20160429190821781 and JCYJ2016429185449249)Science Technology Project of Guangzhou City(201804010185)Science and Technology Innovation Project of Foshan City(1920001000025)Scientific Research Foundation of PEKING UNIVERSITY SHENZHEN HOSPITAL KYQD(2021064)National Young Thousand-Talent Scheme to Zhang Zhi-Yong.
文摘Regardless of the advancement of synthetic bone substitutes,allograft-derived bone substitutes still dominate in the orthopaedic circle in the treatments of bone diseases.Nevertheless,the stringent devitalization process jeopardizes their osseointegration with host bone and therefore prone to long-term failure.Hence,improving osseointegration and transplantation efficiency remains important.The alteration of bone tissue microenvironment(TME)to facilitate osseointegration has been generally recognized.However,the concept of exerting metal ionic cue in bone TME without compromising the mechanical properties of bone allograft is challenging.To address this concern,an interfacial tissue microenvironment with magnesium cationc cue was tailored onto the gamma-irradiated allograft bone using a customized magnesium-plasma surface treatment.The formation of the Mg cationic cue enriched interfacial tissue microenvironment on allograft bone was verified by the scanning ion-selective electrode technique.The cellular activities of human TERT-immortalized mesenchymal stem cells on the Mg-enriched grafts were notably upregulated.In the animal test,superior osseointegration between Mg-enriched graft and host bone was found,whereas poor integration was observed in the gamma-irradiated controls at 28 days post-operation.Furthermore,the bony in-growth appeared on magnesium-enriched allograft bone was significant higher.The mechanism possibly correlates to the up-regulation of integrin receptors in mesenchymal stem cells under modified bone TME that directly orchestrate the initial cell attachment and osteogenic differentiation of mesenchymal stem cells.Lastly,our findings demonstrate the significance of magnesium cation modified bone allograft that can potentially translate to various orthopaedic procedures requiring bone augmentation.
文摘The authors regret a mistake of funding numbers in the Acknowledgment Section failed to be corrected during proof reading.Below is the corrected funding statement in Acknowledgment SECTION This work was supported by the National Natural Science Foundation of China(NSFC)(Nos.81902189,81772354,82002303,31570980),Clinical Innovation Research Program of Guangzhou Regenerative Medicine and Health Guangdong Laboratory(2018GZR0201002),National Key Research and Development Plan(2018YFC1105103).
