Osteoporosis(OP)is a systemic skeletal disease characterized by reduced bone mass and a degenerative bone microarchitecture.Apigenin(API),a flavonoid derived mainly from celery,has been reported to be beneficial for t...Osteoporosis(OP)is a systemic skeletal disease characterized by reduced bone mass and a degenerative bone microarchitecture.Apigenin(API),a flavonoid derived mainly from celery,has been reported to be beneficial for the treatment of OP;however,the underlying mechanisms remain unclear.Moreover,the effects of API on bone-forming cells,including mesenchymal stem cells and osteoblasts,remain unclear.In the present study,we first determined that API treatment could promote bone formation,improve bone metabolism in ovariectomized(OVX)mice,and effectively ameliorate bone loss,as supported by micro-CT scanning and histological staining of mouse femurs.In vitro investigations have confirmed that API has a bidirectional regulatory effect on bone metabolism,promoteing osteogenic differentiation and inhibiting osteoclastogenesis.The further study displayed that the promotion of osteogenesis of bone marrow-derived mesenchymal stem cells from OVX mice mainly through regulating SIRT1 and its downstream HIF1αsignaling.In summary,API treatment may be a novel and promising therapeutic strategy for the treatment of OP.展开更多
The stiffness of the extracellular matrix(ECM)plays an important role in regulating the cellular programming.However,the mechanical characteristics of ECM affecting cell differentiation are still under investigated.He...The stiffness of the extracellular matrix(ECM)plays an important role in regulating the cellular programming.However,the mechanical characteristics of ECM affecting cell differentiation are still under investigated.Herein,we aimed to study the effect of ECM substrate stiffness on macrophage polarization.We prepared polyacrylamide hydrogels with different substrate stiffness,respectively.After the hydrogels were confirmed to have a good biocompatibility,the bone marrow-derived macrophages(BMMs)from mice were incubated on the hydrogels.With simulated by the low substrate stiffness,BMMs displayed an enhanced expression of CD86 on the cell surface and production of reactive oxygen species(ROS)in cells,and secreted more IL-1βand TNF-αin the supernatant.On the contrary,stressed by the medium stiffness,BMMs expressed more CD206,produced less ROS,and secreted more IL-4 and TGF-β.In vivo study by delivered the hydrogels subcutaneously in mice,more CD68+CD86+cells around the hydrogels with the low substrate stiffness were observed while more CD68+CD206+cells near by the middle stiffness hydrogels.In addition,the expressions of NIK,phosphorylated p65(pi-p65)and phosphorylated IκB(pi-IκB)were significantly increased after stimulation with low stiffness in BMMs.Taken together,these findings demonstrated that substrate stiffness could affect macrophages polarization.Low substrate stiffness promoted BMMs to shift to classically activated macrophages(M1)and the middle one to alternatively activated macrophages(M2),through modulating ROS-initiated NF-κB pathway.Therefore,we anticipated ECM-based substrate stiffness with immune modulation would be under consideration in the clinical applications if necessary.展开更多
基金support from the National Natural Science Foundation of China(82172485,82372457)Technology Innovation on Medicine and Health of Suzhou Science and Technology Bureau(SKY2022041,SKY2022171,SKY2023147)Key Laboratory of Orthopaedics of Suzhou(SZS2022017).
文摘Osteoporosis(OP)is a systemic skeletal disease characterized by reduced bone mass and a degenerative bone microarchitecture.Apigenin(API),a flavonoid derived mainly from celery,has been reported to be beneficial for the treatment of OP;however,the underlying mechanisms remain unclear.Moreover,the effects of API on bone-forming cells,including mesenchymal stem cells and osteoblasts,remain unclear.In the present study,we first determined that API treatment could promote bone formation,improve bone metabolism in ovariectomized(OVX)mice,and effectively ameliorate bone loss,as supported by micro-CT scanning and histological staining of mouse femurs.In vitro investigations have confirmed that API has a bidirectional regulatory effect on bone metabolism,promoteing osteogenic differentiation and inhibiting osteoclastogenesis.The further study displayed that the promotion of osteogenesis of bone marrow-derived mesenchymal stem cells from OVX mice mainly through regulating SIRT1 and its downstream HIF1αsignaling.In summary,API treatment may be a novel and promising therapeutic strategy for the treatment of OP.
基金supported by the National Natural Science Foundation of China(81772312,891972059,81772358)Research and Development of Biomedical Materials and Substitution of Tissue and Organ Repair under the National Key R&D Program(2016YFC1101502)+1 种基金the Natural Science Foundation of Jiangsu Province(BK2019668,BK20151210)Jiangsu Provincial Clinical Orthopedic Center,the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘The stiffness of the extracellular matrix(ECM)plays an important role in regulating the cellular programming.However,the mechanical characteristics of ECM affecting cell differentiation are still under investigated.Herein,we aimed to study the effect of ECM substrate stiffness on macrophage polarization.We prepared polyacrylamide hydrogels with different substrate stiffness,respectively.After the hydrogels were confirmed to have a good biocompatibility,the bone marrow-derived macrophages(BMMs)from mice were incubated on the hydrogels.With simulated by the low substrate stiffness,BMMs displayed an enhanced expression of CD86 on the cell surface and production of reactive oxygen species(ROS)in cells,and secreted more IL-1βand TNF-αin the supernatant.On the contrary,stressed by the medium stiffness,BMMs expressed more CD206,produced less ROS,and secreted more IL-4 and TGF-β.In vivo study by delivered the hydrogels subcutaneously in mice,more CD68+CD86+cells around the hydrogels with the low substrate stiffness were observed while more CD68+CD206+cells near by the middle stiffness hydrogels.In addition,the expressions of NIK,phosphorylated p65(pi-p65)and phosphorylated IκB(pi-IκB)were significantly increased after stimulation with low stiffness in BMMs.Taken together,these findings demonstrated that substrate stiffness could affect macrophages polarization.Low substrate stiffness promoted BMMs to shift to classically activated macrophages(M1)and the middle one to alternatively activated macrophages(M2),through modulating ROS-initiated NF-κB pathway.Therefore,we anticipated ECM-based substrate stiffness with immune modulation would be under consideration in the clinical applications if necessary.
