BACKGROUND Recently,type 2 diabetic osteoporosis(T2DOP)has become a research hotspot for the complications of diabetes,but the specific mechanism of its occurrence and development remains unknown.Ferroptosis caused by...BACKGROUND Recently,type 2 diabetic osteoporosis(T2DOP)has become a research hotspot for the complications of diabetes,but the specific mechanism of its occurrence and development remains unknown.Ferroptosis caused by iron overload is con-sidered an important cause of T2DOP.Polycytosine RNA-binding protein 1(PCBP1),an iron ion chaperone,is considered a protector of ferroptosis.AIM To investigate the existence of ferroptosis and specific role of PCBP1 in the development of type 2 diabetes.METHODS A cell counting kit-8 assay was used to detect changes in osteoblast viability under high glucose(HG)and/or ferroptosis inhibitors at different concentrations and times.Transmission electron microscopy was used to examine the morpho-logical changes in the mitochondria of osteoblasts under HG,and western blotting was used to detect the expression levels of PCBP1,ferritin,and the ferroptosis-related protein glutathione peroxidase 4(GPX4).A lentivirus silenced and overex-pressed PCBP1.Western blotting was used to detect the expression levels of the osteoblast functional proteins osteoprotegerin(OPG)and osteocalcin(OCN),whereas flow cytometry was used to detect changes in reactive oxygen species(ROS)levels in each group.RESULTS Under HG,the viability of osteoblasts was considerably decreased,the number of mitochondria undergoing atrophy was considerably increased,PCBP1 and ferritin expression levels were increased,and GPX4 expression was decreased.Western blotting results demonstrated that infection with lentivirus overexpressing PCBP1,increased the expression levels of ferritin,GPX4,OPG,and OCN,compared with the HG group.Flow cytometry results showed a reduction in ROS,and an opposite result was obtained after silencing PCBP1.CONCLUSION PCBP1 may protect osteoblasts and reduce the harm caused by ferroptosis by promoting ferritin expression under a HG environment.Moreover,PCBP1 may be a potential therapeutic target for T2DOP.展开更多
Increasing the osteogenic differentiation ability and decreasing the adipogenic differentiation ability of bone marrow mesenchymal stem cells(BMSCs)is a potential strategy for the treatment of osteoporosis(OP).Natural...Increasing the osteogenic differentiation ability and decreasing the adipogenic differentiation ability of bone marrow mesenchymal stem cells(BMSCs)is a potential strategy for the treatment of osteoporosis(OP).Naturally derived oligosaccharides have shown significant anti-osteoporotic effects.Nystose(NST),an oligosaccharide,was isolated from the roots of Morinda officinalis How.(MO).The aim of the present study was to investigate the effects of NST on bone loss in ovariectomized mice,and explore the underlying mechanism of NST in promoting differentiation of BMSCs to osteoblasts.Administration of NST(40,80 and 160 mg/kg)and the positive control of estradiol valerate(0.2 mg/kg)for 8 weeks significantly prevented bone loss induced by ovariectomy(OVX),increased the bone mass density(BMD),improved the bone microarchitecture and reduced urine calcium and deoxypyridinoline(DPD)in ovariectomized mice,while inhibited the increase of body weight without significantly affecting the uterus weight.Furthermore,we found that NST increased osteogenic differentiation,inhibited adipogenic differentiation of BMSCs in vitro,and upregulated the expression of the key proteins of BMP and Wnt/β-catenin pathways.In addition,Noggin and Dickkopf-related protein-1(DKK-1)reversed the effect of NST on osteogenic differentiation and expression of the key proteins in BMP and Wnt/β-catenin pathway.The luciferase activities and the molecular docking analysis further supported the mechanism of NST.In conclusion,these results indicating that NST can be clinically used as a potential alternative medicine for the prevention and treatment of postmenopausal osteoporosis.展开更多
Osteoblasts are considered as a major factor contributing to bone development and mineralization,however,few studies have been done to establish and evaluate the primary cultured tibial osteoblast model of broiler chi...Osteoblasts are considered as a major factor contributing to bone development and mineralization,however,few studies have been done to establish and evaluate the primary cultured tibial osteoblast model of broiler chicks.Therefore,in the present study,two experiments were conducted to establish and evaluate the primary cultured tibial osteoblast model of broiler chicks.In experiment 1,osteoblasts were isolated from the tibia of one-day-old Arbor Acre male broiler chicks using the explant method and identified through the cell morphology,alkaline phosphatase(ALP)and alizarin red staining.Experiment 2 was carried out to evaluate the vitality and mineralization of primary cultured tibial osteoblasts of broilers on days 4,8,12,16,20,24,28 and 32 after incubation,respectively.The results from experiment 1 demonstrated that primary cultured tibial osteoblasts of broilers showed a spindle-shaped,triangular or polygonal morphology.More than 95%of the cells were stained blue-black after ALP staining,and mineralized nodules were formed after 4 days of continuous incubation.In experiment 2,lactate dehydrogenase(LDH)activity stayed at a relatively stabilized level although incubation time affected(P=0.0012)it during the whole culture period.Additionally,incubation time affected(P≤0.0001)the number and proportion of the area of mineralized nodules.They increased linearly and quadratically(P<0.04)with the increase of incubation time,and remained at a stabilized level from 24 to 32 days of incubation.The estimates of the optimal incubation time were 17 and 26 days based on the best fitted broken-line or quadratic models(P<0.0001)of the number and proportion of the area of mineralized nodules,respectively.These results indicate that the primary cultured tibial osteoblast model of broilers has been established successfully by the explant method,and it showed typical osteoblast morphology and characteristics of ALP activity and mineralization,and could maintain a relatively stabilized vitality from 4 to 32 days of incubation;and the optimal incubation time of primary tibial osteoblasts was 17 to 26 days.Therefore,it could be used to further study the underlying mechanisms of bone development and mineralization of broiler chicks.展开更多
Areca nut is used worldwide as a hallucinogenic addicting drug along the tropical belt.Arecoline,a toxic compound,is the most important alkaloid in areca nuts.The adverse effects of oral uptake and chewing of areca nu...Areca nut is used worldwide as a hallucinogenic addicting drug along the tropical belt.Arecoline,a toxic compound,is the most important alkaloid in areca nuts.The adverse effects of oral uptake and chewing of areca nut are well known.For example,the possibility of cancer caused by chewing areca nuts is widely discussed.Chewing areca nut has other adverse effects on other organs,including abnormal cell differentiation,oral cancer,and several other diseases.The use of areca nut is also associated with low birthweight.Skeletal musculature is the largest organ in the body and is attached to the bones.During embryo development,the differentiation of bone and muscle cells is critical.In this article,we reviewed the effects of areca nut and arecoline on embryonic cell differentiation,particularly osteoblasts,myoblasts,and fibroblasts.展开更多
Bone formation is a highly energy-demanding process that can be impacted by metabolic disorders.Glucose has been considered the principal substrate for osteoblasts,although fatty acids are also important for osteoblas...Bone formation is a highly energy-demanding process that can be impacted by metabolic disorders.Glucose has been considered the principal substrate for osteoblasts,although fatty acids are also important for osteoblast function.Here,we report that osteoblasts can derive energy from endogenous fatty acids stored in lipid droplets via lipolysis and that this process is critical for bone formation.As such,we demonstrate that osteoblasts accumulate lipid droplets that are highly dynamic and provide the molecular mechanism by which they serve as a fuel source for energy generation during osteoblast maturation.Inhibiting cytoplasmic lipolysis leads to both an increase in lipid droplet size in osteoblasts and an impairment in osteoblast function.The fatty acids released by lipolysis from these lipid droplets become critical for cellular energy production as cellular energetics shifts towards oxidative phosphorylation during nutrient-depleted conditions.In vivo,conditional deletion of the ATGL-encoding gene Pnpla2 in osteoblast progenitor cells reduces cortical and trabecular bone parameters and alters skeletal lipid metabolism.Collectively,our data demonstrate that osteoblasts store fatty acids in the form of lipid droplets,which are released via lipolysis to support cellular bioenergetic status when nutrients are limited.Perturbations in this process result in impairment of bone formation,specifically reducing ATP production and overall osteoblast function.展开更多
Objective:To investigate whether acupotomy could inhibit subchondral bone remodeling in knee osteoarthritis(KOA)rabbits by regulating the activity of osteoblasts and osteoclasts.Methods:KOA rabbits were prepared by im...Objective:To investigate whether acupotomy could inhibit subchondral bone remodeling in knee osteoarthritis(KOA)rabbits by regulating the activity of osteoblasts and osteoclasts.Methods:KOA rabbits were prepared by immobilization for 6 and 9 weeks by Videman method.Nine groups of rabbits(control,6 weeks and 9 weeks model,6 weeks and 9 weeks acupotomy,6 weeks and 9 weeks electroacupuncture,and 6 weeks and 9 weeks drug groups)received acupotomy,electroacupuncture and risedronate sodium intervention,respectively,for 3 weeks.Results:Acupotomy can inhibit the activity of osteoclasts and osteoblasts in subchondral bone by reducing the proteins expression of cathepsin K(CK)and tartrate-resistant acid phosphatase(TRAP)and decreasing the proteins expression of osteocalcin(OCN)and alkaline phosphatase(ALP),to intercept the abnormal bone resorption and bone formation of subchondral bone in 6-week and 9-week immobilization-induced KOA rabbits.Conclusion:These findings indicated that acupotomy may be more advantageous than risedronate sodium intervention in modulating subchondral bone remodeling in KOA rabbits,especially in 9-week immobilization-induced KOA rabbits.展开更多
基金Supported by the National Natural Science Foundation of China,No.81471094 and No.82202743.
文摘BACKGROUND Recently,type 2 diabetic osteoporosis(T2DOP)has become a research hotspot for the complications of diabetes,but the specific mechanism of its occurrence and development remains unknown.Ferroptosis caused by iron overload is con-sidered an important cause of T2DOP.Polycytosine RNA-binding protein 1(PCBP1),an iron ion chaperone,is considered a protector of ferroptosis.AIM To investigate the existence of ferroptosis and specific role of PCBP1 in the development of type 2 diabetes.METHODS A cell counting kit-8 assay was used to detect changes in osteoblast viability under high glucose(HG)and/or ferroptosis inhibitors at different concentrations and times.Transmission electron microscopy was used to examine the morpho-logical changes in the mitochondria of osteoblasts under HG,and western blotting was used to detect the expression levels of PCBP1,ferritin,and the ferroptosis-related protein glutathione peroxidase 4(GPX4).A lentivirus silenced and overex-pressed PCBP1.Western blotting was used to detect the expression levels of the osteoblast functional proteins osteoprotegerin(OPG)and osteocalcin(OCN),whereas flow cytometry was used to detect changes in reactive oxygen species(ROS)levels in each group.RESULTS Under HG,the viability of osteoblasts was considerably decreased,the number of mitochondria undergoing atrophy was considerably increased,PCBP1 and ferritin expression levels were increased,and GPX4 expression was decreased.Western blotting results demonstrated that infection with lentivirus overexpressing PCBP1,increased the expression levels of ferritin,GPX4,OPG,and OCN,compared with the HG group.Flow cytometry results showed a reduction in ROS,and an opposite result was obtained after silencing PCBP1.CONCLUSION PCBP1 may protect osteoblasts and reduce the harm caused by ferroptosis by promoting ferritin expression under a HG environment.Moreover,PCBP1 may be a potential therapeutic target for T2DOP.
基金support from the Public Platform of Medical Research Center,Academy of Chinese Medical Science,Zhejiang Chinese Medical Universitysponsored by the National Natural Science Foundation of China(81973534,U1505226)。
文摘Increasing the osteogenic differentiation ability and decreasing the adipogenic differentiation ability of bone marrow mesenchymal stem cells(BMSCs)is a potential strategy for the treatment of osteoporosis(OP).Naturally derived oligosaccharides have shown significant anti-osteoporotic effects.Nystose(NST),an oligosaccharide,was isolated from the roots of Morinda officinalis How.(MO).The aim of the present study was to investigate the effects of NST on bone loss in ovariectomized mice,and explore the underlying mechanism of NST in promoting differentiation of BMSCs to osteoblasts.Administration of NST(40,80 and 160 mg/kg)and the positive control of estradiol valerate(0.2 mg/kg)for 8 weeks significantly prevented bone loss induced by ovariectomy(OVX),increased the bone mass density(BMD),improved the bone microarchitecture and reduced urine calcium and deoxypyridinoline(DPD)in ovariectomized mice,while inhibited the increase of body weight without significantly affecting the uterus weight.Furthermore,we found that NST increased osteogenic differentiation,inhibited adipogenic differentiation of BMSCs in vitro,and upregulated the expression of the key proteins of BMP and Wnt/β-catenin pathways.In addition,Noggin and Dickkopf-related protein-1(DKK-1)reversed the effect of NST on osteogenic differentiation and expression of the key proteins in BMP and Wnt/β-catenin pathway.The luciferase activities and the molecular docking analysis further supported the mechanism of NST.In conclusion,these results indicating that NST can be clinically used as a potential alternative medicine for the prevention and treatment of postmenopausal osteoporosis.
基金supported by the Key Program of the National Natural Science Foundation of China(31630073)the Initiation Funds of Yangzhou University for Distinguished Scientists,Chinathe Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(ASTIP-IAS09)。
文摘Osteoblasts are considered as a major factor contributing to bone development and mineralization,however,few studies have been done to establish and evaluate the primary cultured tibial osteoblast model of broiler chicks.Therefore,in the present study,two experiments were conducted to establish and evaluate the primary cultured tibial osteoblast model of broiler chicks.In experiment 1,osteoblasts were isolated from the tibia of one-day-old Arbor Acre male broiler chicks using the explant method and identified through the cell morphology,alkaline phosphatase(ALP)and alizarin red staining.Experiment 2 was carried out to evaluate the vitality and mineralization of primary cultured tibial osteoblasts of broilers on days 4,8,12,16,20,24,28 and 32 after incubation,respectively.The results from experiment 1 demonstrated that primary cultured tibial osteoblasts of broilers showed a spindle-shaped,triangular or polygonal morphology.More than 95%of the cells were stained blue-black after ALP staining,and mineralized nodules were formed after 4 days of continuous incubation.In experiment 2,lactate dehydrogenase(LDH)activity stayed at a relatively stabilized level although incubation time affected(P=0.0012)it during the whole culture period.Additionally,incubation time affected(P≤0.0001)the number and proportion of the area of mineralized nodules.They increased linearly and quadratically(P<0.04)with the increase of incubation time,and remained at a stabilized level from 24 to 32 days of incubation.The estimates of the optimal incubation time were 17 and 26 days based on the best fitted broken-line or quadratic models(P<0.0001)of the number and proportion of the area of mineralized nodules,respectively.These results indicate that the primary cultured tibial osteoblast model of broilers has been established successfully by the explant method,and it showed typical osteoblast morphology and characteristics of ALP activity and mineralization,and could maintain a relatively stabilized vitality from 4 to 32 days of incubation;and the optimal incubation time of primary tibial osteoblasts was 17 to 26 days.Therefore,it could be used to further study the underlying mechanisms of bone development and mineralization of broiler chicks.
基金the funding provided by the Ministry of Science and Technology,Taiwan(108-2314-B-037-075)the Kaohsiung Medical University Research Foundation(KMU-M103001,KMU-M104003,KMU-TP104PR16).
文摘Areca nut is used worldwide as a hallucinogenic addicting drug along the tropical belt.Arecoline,a toxic compound,is the most important alkaloid in areca nuts.The adverse effects of oral uptake and chewing of areca nut are well known.For example,the possibility of cancer caused by chewing areca nuts is widely discussed.Chewing areca nut has other adverse effects on other organs,including abnormal cell differentiation,oral cancer,and several other diseases.The use of areca nut is also associated with low birthweight.Skeletal musculature is the largest organ in the body and is attached to the bones.During embryo development,the differentiation of bone and muscle cells is critical.In this article,we reviewed the effects of areca nut and arecoline on embryonic cell differentiation,particularly osteoblasts,myoblasts,and fibroblasts.
基金supported by National Institutes of Health(NIH),the National Institute of Arthritis and Musculoskeletal and Skin Diseases(NIAMS)Grant K01AR072123(ER-R)the American Society of Bone and Mineral Research(ASBMR)Rising Star awardprovided by NIH-National Institute of Diabetes and Digestive and Kidney Disease(NIDDK)Grant DK116056(MPC)。
文摘Bone formation is a highly energy-demanding process that can be impacted by metabolic disorders.Glucose has been considered the principal substrate for osteoblasts,although fatty acids are also important for osteoblast function.Here,we report that osteoblasts can derive energy from endogenous fatty acids stored in lipid droplets via lipolysis and that this process is critical for bone formation.As such,we demonstrate that osteoblasts accumulate lipid droplets that are highly dynamic and provide the molecular mechanism by which they serve as a fuel source for energy generation during osteoblast maturation.Inhibiting cytoplasmic lipolysis leads to both an increase in lipid droplet size in osteoblasts and an impairment in osteoblast function.The fatty acids released by lipolysis from these lipid droplets become critical for cellular energy production as cellular energetics shifts towards oxidative phosphorylation during nutrient-depleted conditions.In vivo,conditional deletion of the ATGL-encoding gene Pnpla2 in osteoblast progenitor cells reduces cortical and trabecular bone parameters and alters skeletal lipid metabolism.Collectively,our data demonstrate that osteoblasts store fatty acids in the form of lipid droplets,which are released via lipolysis to support cellular bioenergetic status when nutrients are limited.Perturbations in this process result in impairment of bone formation,specifically reducing ATP production and overall osteoblast function.
基金supported by the Beijing Municipal Natural Science Foundation(7192110)。
文摘Objective:To investigate whether acupotomy could inhibit subchondral bone remodeling in knee osteoarthritis(KOA)rabbits by regulating the activity of osteoblasts and osteoclasts.Methods:KOA rabbits were prepared by immobilization for 6 and 9 weeks by Videman method.Nine groups of rabbits(control,6 weeks and 9 weeks model,6 weeks and 9 weeks acupotomy,6 weeks and 9 weeks electroacupuncture,and 6 weeks and 9 weeks drug groups)received acupotomy,electroacupuncture and risedronate sodium intervention,respectively,for 3 weeks.Results:Acupotomy can inhibit the activity of osteoclasts and osteoblasts in subchondral bone by reducing the proteins expression of cathepsin K(CK)and tartrate-resistant acid phosphatase(TRAP)and decreasing the proteins expression of osteocalcin(OCN)and alkaline phosphatase(ALP),to intercept the abnormal bone resorption and bone formation of subchondral bone in 6-week and 9-week immobilization-induced KOA rabbits.Conclusion:These findings indicated that acupotomy may be more advantageous than risedronate sodium intervention in modulating subchondral bone remodeling in KOA rabbits,especially in 9-week immobilization-induced KOA rabbits.
