Excessive osteoclastogenesis-mediated osteoporosis has been recognized as a global health concern.Candidate compounds derived from medicinal plants or functional foods are promising to treat osteoporosis due to their ...Excessive osteoclastogenesis-mediated osteoporosis has been recognized as a global health concern.Candidate compounds derived from medicinal plants or functional foods are promising to treat osteoporosis due to their high safety and efficiency.(−)-Epigallocatechin-3-gallate(EGCG)is the most abundant and biologically active polyphenol in green tea.It can inhibit osteoclastogenesis in vitro by blocking receptor activator of nuclear factor(NF)-κB(RANK)signaling pathways.This study used the ovariectomized(OVX)mouse model to estimate the therapeutic effect of EGCG on osteoporosis and verified the molecular mechanism in vivo.The results revealed that EGCG significantly inhibited the OVX-induced body weight gain.Moreover,no adverse effects were observed on blood glucose,histomorphological features,weights,as well as indices of liver and kidney in OVX mice.EGCG could significantly ameliorate bone loss in OVX mice by inhibiting osteoclastogenesis.This effect was evidenced by the reduced number of osteoclasts and the increased trabecular bone area in the femurs.Moreover,EGCG inhibited the activities of c-telopeptide of type I collagen(CTX-I)and tartrate-resistant acid phosphatase 5b(TRACP-5b)and strengthened bone gla protein(BGP)and procollagen I N-terminal peptide(PINP)activities in OVX mice.Mechanistically,EGCG significantly downregulated the expression of osteoclastogenesis-related marker genes and proteins,including nuclear factor of activated T cells,cytoplasmic 1(NFATc1),c-Fos,tartrate-resistant acid phosphatase(TRAP),c-Src,and cathepsin K.In addition,the phosphorylation levels of p65,c-Jun N-terminal kinase(JNK),extracellular signal-regulated kinase 1/2(ERK1/2),p38,and protein kinase B(AKT)were significantly suppressed in OVX mice.It was found that EGCG could alleviate OVX-induced bone loss in mice by suppressing osteoclastogenesis by blocking the NF-κB,mitogen-activated protein kinase(MAPK),and AKT signaling pathways.EGCG has the potential to prevent and treat osteoclast-related diseases such as osteoporosis.展开更多
BACKGROUND Ankylosing spondylitis(AS)is recognized as a long-term inflammatory disorder that leads to inflammation in the spine and joints,alongside abnormal bone growth.In previous studies,we reported that mesenchyma...BACKGROUND Ankylosing spondylitis(AS)is recognized as a long-term inflammatory disorder that leads to inflammation in the spine and joints,alongside abnormal bone growth.In previous studies,we reported that mesenchymal stem cells(MSCs)derived from individuals with AS demonstrated a remarkable inhibition in the formation of osteoclasts compared to those obtained from healthy donors.The mechanism through which MSCs from AS patients achieve this inhibition remains unclear.AIM To investigate the potential underlying mechanism by which MSCs from individuals with ankylosing spondylitis(AS-MSCs)inhibit osteoclastogenesis.METHODS We analysed fat mass and obesity-associated(FTO)protein levels in AS-MSCs and MSCs from healthy donors and investigated the effects and mechanism by which FTO in MSCs inhibits osteoclastogenesis by coculturing and measuring the levels of tartrate-resistant acid phosphatase,nuclear factor of activated T cells 1 and cathepsin K.RESULTS We found that FTO,an enzyme responsible for removing methyl groups from RNA,was more abundantly expressed in MSCs from AS patients than in those from healthy donors.Reducing FTO levels was shown to diminish the capacity of MSCs to inhibit osteoclast development.Further experimental results revealed that FTO affects the stability of the long non-coding RNA activated by DNA damage(NORAD)by altering its N6-methyladenosine methylation status.Deactivating NORAD in MSCs significantly increased osteoclast formation by affecting miR-4284,which could regulate the MSC-mediated inhibition of osteoclastogenesis reported in our previous research.CONCLUSION This study revealed elevated FTO levels in AS-MSCs and found that FTO regulated the ability of AS-MSCs to inhibit osteoclast formation through the long noncoding RNA NORAD/miR-4284 axis.展开更多
Steroidal alkaloids are the main active components in many medicinal plants and exhibit diverse biological activities.Axillaridine A(AA)is a newly discovered steroidal alkaloid.However,whether AA could suppress osteoc...Steroidal alkaloids are the main active components in many medicinal plants and exhibit diverse biological activities.Axillaridine A(AA)is a newly discovered steroidal alkaloid.However,whether AA could suppress osteoclastogenesis and alleviate ovariectomy-induced bone loss in mice remains unknown.In vitro,AA significantly suppressed the receptor activator of nuclear factor-κB(NF-κB)ligand(RANKL)-induced osteoclast differentiation via downregulating the expression of osteoclastogenesis-related marker genes,proteins,and transcriptional regulators,including tartrate-resistant acid phosphatase(TRAP),c-Src,matrix metallopeptidase-9(MMP-9),cathepsin K,nuclear factor of activated T cells,cytoplasmic 1(NFATc1),and c-Fos.This was achieved by blocking RANKL-RANK interaction and inhibiting RANKL-mediated RANK signaling pathways,including NF-κB,AKT,and mitogen-activated protein kinases(MAPKs)in osteoclast precursors.In vivo,AA significantly inhibited the ovariectomized(OVX)-induced body weight gain and blood glucose increase in mice.AA did not adversely affect the histomorphologies,weights,and indices of the kidney and liver in OVX mice.AA effectively ameliorated bone loss in OVX mice by inhibiting osteoclastogenesis.AA significantly inhibited the serum levels of tartrate-resistant acid phosphatase 5b(TRACP-5b)and C-telopeptide of type I collagen(CTX-I).AA significantly inhibited the OVX-induced expression of osteoclastogenesis-related marker genes and proteins in the femur.In summary,AA alleviates ovariectomy-induced bone loss in mice by suppressing osteoclastogenesis via inhibition of RANKL-mediated RANK signaling pathways and could be potentially used for the prevention and treatment of osteoclastrelated diseases such as osteoporosis.展开更多
Type II autosomal dominant osteopetrosis(ADO2), which is the most common form of osteopetrosis, is caused by heterozygous mutations in the chloride channel 7(CLCN7) gene. The osteopetrosis of ADO2 has been attributed ...Type II autosomal dominant osteopetrosis(ADO2), which is the most common form of osteopetrosis, is caused by heterozygous mutations in the chloride channel 7(CLCN7) gene. The osteopetrosis of ADO2 has been attributed to hypofunctional osteoclasts. The mechanism underlying the abnormality in osteoclast function remains largely unknown. This study was designed to investigate gene mutations and osteoclast function in a case that was clinically diagnosed as ADO2. Genomic DNA was extracted from blood samples of this patient, and the 25 exons of CLCN7 were amplified. Peripheral blood from the ADO2 subject and a healthy age- and sex-matched control was used to evaluate osteoclastogenesis, osteoclast morphology, and bone resorption. Analysis of DNA from the patient showed a germline heterozygous missense mutation,c.1856C>T(p.P619L), in exon 20 of CLCN7. A similar homozygous mutation at this site was previously reported in a patient with autosomal recessive osteopetrosis. When cultured, the peripheral blood mononuclear cells(PBMCs) from the ADO2 patient spontaneously differentiated into mature osteoclasts in vitro. The ADO2 patient’s PBMCs formed enhanced, but heterogeneous, osteoclasts in both the presence and absence of macrophage-colony stimulating factor, and nuclear factor-?B ligand. Bone resorption was reduced in the ADO2 patient’s osteoclasts, which exhibited aberrant morphology and abnormal distribution of integrin avβ3. Gene analysis found increased c-fos expression and reduced Rho A and integrin beta 3expression in ADO2 cells. In conclusion, our data suggest that enhanced, heterogeneous osteoclast induction may be an intrinsic characteristic of ADO2.展开更多
Bone remodeling is performed under the joint action of osteoblasts and osteoclasts. Since the effect of osteoclasts has been gradually recognized on bone and joint diseases, targeted researches toward osteoclasts have...Bone remodeling is performed under the joint action of osteoblasts and osteoclasts. Since the effect of osteoclasts has been gradually recognized on bone and joint diseases, targeted researches toward osteoclasts have become a hot research field. This article reviews the relevant medical literature concerning the possible effects of the fluid shear stress (FSS) on the osteoclastogenesis chiefly from the aspects of RANKL-RANK-OPG system, the macrophage colony-stimulating factor (M-CSF), and calcitonin receptor (CTR). On the basis of the changes of the expression of osteoclastic activities, it is suggested that FSS is a potent, important regulator of bone metabolism.展开更多
Green tea catechin, (–)-epigallocatechin-3-gallate [(–)-EGCG], was found to increase osteogenic functioning in mesenchymal stem cells. This study qualified EGCG, the strongest inhibitory efficiency for receptor acti...Green tea catechin, (–)-epigallocatechin-3-gallate [(–)-EGCG], was found to increase osteogenic functioning in mesenchymal stem cells. This study qualified EGCG, the strongest inhibitory efficiency for receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL)-activated osteoclastogenesis among other green tea catechins for RAW264, a murine preosteoclast cell line. Moreover, EGCG inhibited tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cell formation dose dependently in both single culture and co-culture systems, the expression of transcription factor, nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) and some osteoclastic genes. Especially, EGCG exhibited a strong inhibitory effect on the expression levels of RANK, the receptor of RANKL, and OSCAR, a key co-stimulator of the RANKL/RANK signal. Simultaneously, apoptotic genes expression and Hoechst staining revealed that EGCG induced apoptosis in RAW264. Taken together, these data suggest that the inhibitory effect of EGCG to osteoclastogenesis is associated with a down regulation of RANKL/RANK signal, and increased apoptosis of preosteoclasts.展开更多
Breast cancer(BC)often spreads to bones,leading to bone metastasis(BM).Current targeted therapies have limited effectiveness in the treatment of this condition.Osteoclasts,which contribute to bone destruction,are cruc...Breast cancer(BC)often spreads to bones,leading to bone metastasis(BM).Current targeted therapies have limited effectiveness in the treatment of this condition.Osteoclasts,which contribute to bone destruction,are crucial in supporting tumor cell growth in the bones.Breast cancer bone metastasis(BCBM)treatments have limited efficacy and can cause adverse effects.Ononin exhibits anticancer properties against various cancers.The study examined the impact of ononin on the BCBM and the signaling pathways involved.Our study utilized a variety of experimental techniques,including cell viability assays,colony formation assays,wound-healing assays,Transwell migration assays,Western blot analysis,and tartrate-resistant acid phosphatase(TRAP)staining.We examined the effects of ononin on osteoclastogenesis induced in MDA-MB-231 conditioned medium-and RANKL-treated RAW 264.7 cells.In a mouse model of BCBM,ononin reduced tumor-induced bone destruction.Ononin treatment effectively inhibited proliferation and colony formation and reduced the metastatic capabilities of MDA-MB-231 cells by suppressing cell adhesion,invasiveness,and motility and reversing epithelial–mesenchymal transition(EMT)markers.Ononin markedly suppressed osteoclast formation and osteolysis-associated factors in MDA-MB-231 cells,as well as blocked the activation of the mitogen-activated protein kinase(MAPK)pathway in RAW 264.7 cells.Ononin treatment down-regulated the phosphorylation of MAPK signaling pathways,as confirmed using MAPK agonists or inhibitors.Ononin treatment had no adverse effects on the organ function.Our findings suggest that ononin has therapeutic potential as a BCBM treatment by targeting the MAPK pathway.展开更多
Osteoporosis is caused by an osteoclast activation mechanism.People suffering from osteoporosis are prone to bone defects.Increasing evidence indicates that scavenging reactive oxygen species(ROS)can inhibit receptor ...Osteoporosis is caused by an osteoclast activation mechanism.People suffering from osteoporosis are prone to bone defects.Increasing evidence indicates that scavenging reactive oxygen species(ROS)can inhibit receptor activator of nuclear factorκB ligand(RANKL)-induced osteoclastogenesis and suppress ovariectomy-induced osteoporosis.It is critical to develop biomaterials with antioxidant properties to modulate osteoclast activity for treating osteoporotic bone defects.Previous studies have shown that manganese(Mn)can improve bone regeneration,and Mn supplementation may treat osteoporosis.However,the effect of Mn on osteoclasts and the role of Mn in osteoporotic bone defects remain unclear.In present research,a model bioceramic,Mn-containedβ-tricalcium phosphate(Mn-TCP)was prepared by introducing Mn intoβ-TCP.The introduction of Mn intoβ-TCP significantly improved the scavenging of oxygen radicals and nitrogen radicals,demonstrating that Mn-TCP bioceramics might have antioxidant properties.The in vitro and in vivo findings revealed that Mn^(2+)ions released from Mn-TCP bioceramics could distinctly inhibit the formation and function of osteoclasts,promote the differentiation of osteoblasts,and accelerate bone regeneration under osteoporotic conditions in vivo.Mechanistically,Mn-TCP bioceramics inhibited osteoclastogenesis and promoted the regeneration of osteoporotic bone defects by scavenging ROS via Nrf2 activation.These results suggest that Mn-containing bioceramics with osteoconductivity,ROS scavenging and bone resorption inhibition abilities may be an ideal biomaterial for the treatment of osteoporotic bone defect.展开更多
Background The cannabinoid receptor-2 （CB2） is important for bone remodeling. In this study, we investigated the effects of CB2 selective antagonist （AM630） on receptor activator of nuclear factor kappa B （RANK）...Background The cannabinoid receptor-2 （CB2） is important for bone remodeling. In this study, we investigated the effects of CB2 selective antagonist （AM630） on receptor activator of nuclear factor kappa B （RANK） ligand （RANKL）induced osteoclast differentiation and the underlying signaling pathway using a monocyte-macrophage cell line-RAW264.7.Methods RAW264.7 was cultured with RANKL for 6 days and then treated with AM630 for 24 hours. Mature osteoclasts were measured by tartrate-resistant acid phosphatase （TRAP） staining using a commercial kit. Total ribonucleic acid （RNA）was isolated and real-time reverse transcriptase-polymerase chain reaction （RT-PCR） was done to examine the expression of RANK, cathepsin K （CPK） and nuclear factor kappa B （NF-κB）. The extracellular signal-regulated kinase （ERK）,phosphorylation of ERK （P-ERK） and NF-κB production were tested by Western blotting. The effect of AM630 on RAW264.7 viability was determined using the 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazoliumbromide （MTT） assay.Results AM630 did not affect the viability of RAW264.7. However, this CB2 selective antagonist markedly inhibited osteoclast formation and the inhibition rate was dose-dependent. The dose of 〉100 nmol/L could reduce TRAP positive cells to the levels that were significantly lower than the control. AM630 suppressed the expression of genes associated with osteoclast differentiation and activation, such as RANK and CPK. An analysis of a signaling pathway showed that AM630 inhibited the RANKL-induced activation of ERK, but not NF-κB.Conclusion AM630 could inhibit the osteoclastogenesis from RAW264.7 induced with RANKL.展开更多
Macrophages and osteoclasts are both derived from monocyte/macrophage lineage,which plays as the osteoclastic part of bone metabolism.Although they are regulated by bone implant surface nanoarchitecture and involved i...Macrophages and osteoclasts are both derived from monocyte/macrophage lineage,which plays as the osteoclastic part of bone metabolism.Although they are regulated by bone implant surface nanoarchitecture and involved in osseointegration,the beneath mechanism has not been simultaneously analyzed in a given surface model and their communication with osteoblasts is also blurring.Here,the effect of implant surface topography on monocyte/macrophage lineage osteoclastogenesis and the subsequent effect on osteogenesis are systematically investigated.The nanoporous surface is fabricated on titanium implant by etching and anodizing to get the nanotubes structure.The early bone formation around implant is significantly accelerated by the nanoporous surface in vivo.Meanwhile,the macrophage recruitment and osteoclast formation are increased and decreased respectively.Mechanistically,the integrin mediated FAK phosphorylation and its downstream MAPK pathway(p-p38)are significantly downregulated by the nanoporous surface,which account for the inhibition of osteoclastogenesis.In addition,the nanoporous surface can alleviate the inhibition of osteoclasts on osteogenesis by changing the secretion of clastokines,and accelerate bone regeneration by macrophage cytokine profiles.In conclusion,these data indicate that physical topography of implant surface is a critical factor modulating monocyte/macrophage lineage commitment,which provides theoretical guidance and mechanism basis for promoting osseointegration by coupling the osteogenesis and osteoclastogenesis.展开更多
Osteoporosis is a reduction in skeletal mass due to the decrease of osteogenic ability and the activation of the osteoclastic function.Inhibiting bone resorption and accelerating the new bone formation is a promising ...Osteoporosis is a reduction in skeletal mass due to the decrease of osteogenic ability and the activation of the osteoclastic function.Inhibiting bone resorption and accelerating the new bone formation is a promising strategy to repair the bone defect of osteoporosis.In this study,we first systematically investigated the roles of Chinese medicine Asperosaponin Ⅵ(ASP Ⅵ)on osteogenic mineralization of BMSCs and osteoclastogenesis of BMMs,and then explored the synergistic effect of ASP Ⅵ and BS(BMP-2 immobilized in 2-N,6-O-sulfated chitosan)on bone formation.The result showed that ASP Ⅵ with the concentration lower than 10^(-4) M contributed to the expression of osteogenic gene and inhibited osteoclastic genes RANKL of BMSCs.Simultaneously,ASP Ⅵ significantly reduced the differentiation of mononuclear osteoclasts in the process of osteoclast formation induced by M-CSF and RANKL.Furthermore,by stimulating the SMADs,TGF-β1,VEGFA,and OPG/RANKL signaling pathways,ASBS(ASP Ⅵ and BS)substantially enhanced osteogenesis,greatly promoted angiogenesis,and suppressed osteoclastogenesis.The findings provide a new perspective on osteoporosis care and prevention.展开更多
Currently,implant-associated bacterial infections account for most hospital-acquired infections in patients suffering from bone fractures or defects.Poor osseointegration and aggravated osteolysis remain great challen...Currently,implant-associated bacterial infections account for most hospital-acquired infections in patients suffering from bone fractures or defects.Poor osseointegration and aggravated osteolysis remain great challenges for the success of implants in infectious scenarios.Consequently,developing an effective surface modification strategy for implants is urgently needed.Here,a novel nanoplatform(GO/Ga)consisting of graphene oxide(GO)and gallium nanoparticles(GaNPs)was reported,followed by investigations of its in vitro antibacterial activity and potential bacterium inactivation mechanisms,cytocompatibility and regulatory actions on osteoblastogenesis and osteoclastogenesis.In addition,the possible molecular mechanisms underlying the regulatory effects of GO/Ga nanocomposites on osteoblast differentiation and osteoclast formation were clarified.Moreover,an in vivo infectious microenvironment was established in a rat model of implant-related femoral osteomyelitis to determine the therapeutic efficacy and biosafety of GO/Ga nanocomposites.Our results indicate that GO/Ga nanocomposites with excellent antibacterial potency have evident osteogenic potential and inhibitory effects on osteoclast differentiation by modulating the BMP/Smad,MAPK and NF-κB signaling pathways.The in vivo experiments revealed that the administration of GO/Ga nanocomposites significantly inhibited bone infections,reduced osteolysis,promoted osseointegration located in implant-bone interfaces,and resulted in satisfactory biocompatibility.In summary,this synergistic therapeutic system could accelerate the bone healing process in implant-associated infections and can significantly guide the future surface modification of implants used in bacteria-infected environments.展开更多
We has synthesized the biocompatible gelatin reduced graphene oxide(GOG)in previous research,and in this study we would further evaluate its effects on bone remodeling in the aspects of osteoclastogenesis and angiogen...We has synthesized the biocompatible gelatin reduced graphene oxide(GOG)in previous research,and in this study we would further evaluate its effects on bone remodeling in the aspects of osteoclastogenesis and angiogenesis so as to verify its impact on accelerating orthodontic tooth movement.The mouse orthodontic tooth movement(OTM)model tests in vivo showed that the tooth movement was accelerated in the GOG local injection group with more osteoclastic bone resorption and neovascularization compared with the PBS injection group.The analysis on the degradation of GOG in bone marrow stromal stem cells(BMSCs)illustrated its good biocompatibility in vitro and the accumulation of GOG in spleen after local injection of GOG around the teeth in OTM model in vivo also didn’t influence the survival and life of animals.The co-culture of BMSCs with hematopoietic stem cells(HSCs)or human umbilical vein endothelial cells(HUVECs)in transwell chamber systems were constructed to test the effects of GOG stimulated BMSCs on osteoclastogenesis and angiogenesis in vitro.With the GOG stimulated BMSCs co-culture in upper chamber of transwell,the HSCs in lower chamber manifested the enhanced osteoclastogenesis.Meanwhile,the co-culture of GOG stimulated BMSCs with HUVECs showed a promotive effect on the angiogenic ability of HUVECs.The mechanism analysis on the biofunctions of the GOG stimulated BMSCs illustrated the important regulatory effects of PERK pathway on osteoclastogenesis and angiogenesis.All the results showed the biosecurity of GOG and the biological functions of GOG stimulated BMSCs in accelerating bone remodeling and tooth movement.展开更多
Background： Calpain, a calcium-dependent cysteine protease, has been demonstrated to regulate osteoclastogenesis, which is considered one of the major reasons for cancer-induced bone pain （CIBP）. In the present stu...Background： Calpain, a calcium-dependent cysteine protease, has been demonstrated to regulate osteoclastogenesis, which is considered one of the major reasons for cancer-induced bone pain （CIBP）. In the present study, calpain inhibitor was applied in a rat CIBP model to determine whether it could reduce CIBP through regulation of osteoclastogenesis activity. Methods： A rat CIBP model was established with intratibial injection of Walker 256 cells. Then, the efficacy of intraperitoneal administered calpain inhibitor III （MDL28170, 1 mg/kg） on mechanical withdrawal threshold （MWT） of bilateral hind paws was examined on postoperative days （PODs） 2, 5, 8, 11, and 14. On POD 14, the calpain inhibitor＇s effect on tumor bone tartrate-resistant acid phosphatase （TRAP） stain and radiology was also carefully investigated. Results： Pain behavioral tests in rats showed that the calpain inhibitor effectively attenuated MWTs of both the surgical side and contralateral side hind paws on POD 5, 8, and 11 （P 〈 0.05）. TRAP-positive cell count of the surgical side bone was significantly decreased in the calpain inhibitor group compared with the vehicle group （P 〈 0.05）. However, bone resorption and destruction measured by radiographs showed no difference between the two groups. Conclusions： Calpain inhibitor can effectively reduce CIBP of both the surgical side and nonsurgical side after tumor injection in a rat CIBP model. It may be due to the inhibition of receptor activator of nuclear factor-kappa B ligand-induced osteoclastogenesis. Whether a calpain inhibitor could be a novel therapeutic target to treat CIBP needs further investigation.展开更多
Purpose： To investigate the influence of the same mechanical loading on osteogenesis and osteoclastogenesis in vitro. Methods： Primary osteoblasts, bone marrow-derived mesenchymal stem cells （BMSCs, cultured in ost...Purpose： To investigate the influence of the same mechanical loading on osteogenesis and osteoclastogenesis in vitro. Methods： Primary osteoblasts, bone marrow-derived mesenchymal stem cells （BMSCs, cultured in osteoinductive medium） and RAW264.7 cells cultured in osteoclast inductive medium were all subjected to a 1000μstrain （μs） at 1 Hz cyclic mechanical stretch for 30 min （twice a day）. Results： After mechanical stimulation, the alkaline phosphatase （ALP） activity, osteocalcin protein level of the osteoblasts and BMSCs were all enhanced, and the mRNA levels of ALP and collagen type I increased. Additionally, extracellular-deposited calcium of both osteoblasts and BMSCs increased. At the same time, the activity of secreted tartrate-resistant acid phosphatase, the number of tartrate-resistant acid phosphatase-positive multinucleated cells, matrix metalloproteinase-9 protein levels of RAW264.7 cells and the extracellular calcium solvency all decreased. Conclusion： The results demonstrated that 1000 μs cyclic mechanical loading enhanced osteoblasts activity, promoted osteoblastic differentiation of BMSCs and restrained osteoclastogenesis of RAW264.7 cells in vitro.展开更多
The excessive reactive oxygen species (ROS) accumulation and overactivated osteoclastogenesis in subchondral bone has proved to be a major cause of osteoarthritis (OA). Scavenging of ROS microenvironment to inhibit th...The excessive reactive oxygen species (ROS) accumulation and overactivated osteoclastogenesis in subchondral bone has proved to be a major cause of osteoarthritis (OA). Scavenging of ROS microenvironment to inhibit the osteoclastogenesis is highly valued in the therapeutic process of osteoarthritis. Despite the excellent ability of polyphenolic colloidal to scavenge reactive oxygen species and its affinity for macrophages, the preparation of polyphenolic colloidal nanoparticles is limited by the complex intermolecular forces between phenol molecules and the lack of understanding of polymerization/sol-gel chemistry. Herein, our work introduces a novel poly-tannin-phenylboronic colloidal nanoparticle (PTA) exclusively linked by ROS-responsive bondings. Nanocolloidal PTA has a uniform particle size, is easy and scalable to synthesize, has excellent scavenging of ROS, and can be slowly degraded. For in vitro experiments, we demonstrated that, PTA could eliminate ROS within RAW264.7 cells and impede osteoclastogenesis and bone resorption. RNA sequencing results of PTA-treated RAW264.7 cells further reveal the promotion of antioxidant activity and inhibition of osteoclastogenesis. For in vivo experiments, PTA could eliminate the ROS environment and reduce the number of osteoclasts in the subchondral bone, thereby alleviating the damage of subchondral bone and symptoms of osteoarthritis. Our research, by delving into the formation of polyphenol colloidal nanoparticles and validating their role in ROS scavenging to inhibit osteoclastogenesis in subchondral bone, may open new avenues for OA treatment in the future.展开更多
Inflammation can initiate osteolysis,which is the breakdown of bone by fully developed osteoclasts.The com-pound Oleandrin is recognized for its effects against inflammation and tumors.Our objective was to examine the...Inflammation can initiate osteolysis,which is the breakdown of bone by fully developed osteoclasts.The com-pound Oleandrin is recognized for its effects against inflammation and tumors.Our objective was to examine the effects of Oleandrin on osteoclastogenesis and osteolysis,both in vitro and in vivo.In vitro,the impact of Oleandrin on osteoclastogenesis was assessed using CCK-8 assays,TRAP staining,and bone resorption assays.Ad-ditionally,a mouse model of osteolysis caused by LPS injection into the calvaria was used to conduct an in vivo investigation,examining bone histomorphology,histology,and immunohistochemistry.In vitro,concentrations of 5 nM and 10 nM of Oleandrin were found to be non-cytotoxic based on the results obtained.In vitro,Olean-drin hindered the osteoclastogenesis and bone resorption induced by RANKL.Oleandrin successfully inhibited the phosphorylation of NF-κB p65 and PI3K p85 in osteolytic tissue,thereby suppressing LPS-induced inflammatory osteolysis in mice calvaria during the in vivo study.Furthermore,the Oleandrin-treated group exhibited a note-worthy decrease in the expression level of NFATc1,which is a crucial controller of osteoclastogenesis.To sum up,our discoveries indicate that Oleandrin could hinder osteoclastogenesis and bone resorption,thereby having the ability to suppress inflammation-induced osteolysis.The underlying mechanism involves the NF-κB/PI3K pathway and inhibition of NFATc1 activation.Therefore,the findings suggest that Oleandrin holds potential as a therapeutic remedy for osteolytic ailments.展开更多
This study investigated the regulatory potential of salidroside(SAL),a primary active compound in Rhodiola rosea L.,on osteoclast differentiation by modulating the hypoxia-inducible factor 1-alpha(HIF-1α)pathway in o...This study investigated the regulatory potential of salidroside(SAL),a primary active compound in Rhodiola rosea L.,on osteoclast differentiation by modulating the hypoxia-inducible factor 1-alpha(HIF-1α)pathway in osteoblasts.Luciferase reporter assay and chromatin immunoprecipitation(Ch IP)assay were employed to validate whether the receptor activator of nuclear factor-κB ligand(RANKL)is the downstream target gene of HIF-1αin osteoblasts.The study also utilized lipopolysaccharide(LPS)-induced mouse osteolysis to examine the impact of SAL on osteolysis in vivo.Furthermore,conditioned medium(CM)from SAL-pretreated osteoblasts was used to investigate the paracrine effects on osteoclastogenesis through the HIF-1αpathway.Hypoxic condition-induced overexpression of HIF-1αupregulated RANKL levels by binding to the RANKL promoter and enhancing transcription in osteoblastic cells.In vivo,SAL significantly alleviated bone tissue hypoxia and decreased the expression of HIF-1αby downregulating the expression of RANKL,vascular endothelial growth factor(VEGF),interleukin 6(IL-6),and angiopoietin-like 4(ANGPTL4).In the paracrine experiment,conditioned media from SAL-pretreated osteoblasts inhibited differentiation through the HIF-1α/RANKL,VEGF,IL-6,and ANGPTL4 pathways.RANKL emerges as the downstream target gene regulated by HIF-1αin osteoblasts.SAL significantly alleviates bone tissue hypoxia and bone loss in LPS-induced osteolysis through the HIF-1α/RANKL,VEGF,IL-6,and ANGPTL4 pathways.SAL inhibits osteoclast differentiation by regulating osteoblast paracrine secretion.展开更多
Invasive fibroblast-like synoviocytes(FLS),inflammatory macrophages and osteoclasts are the main three contributors to rheumatoid arthritis(RA)progression by promoting synovial inflammation and destructing cartilage a...Invasive fibroblast-like synoviocytes(FLS),inflammatory macrophages and osteoclasts are the main three contributors to rheumatoid arthritis(RA)progression by promoting synovial inflammation and destructing cartilage and bone.Targeting these three cell types for restoring the inflammatory homeostasis microenvironment may be a promising anti-RA strategy.Herein,we prepared a reactive oxygen species(ROS)-responsive micelles(DPTM)to co-load dexamethasone(DEX)and pristimerin(PRI)for RA therapy.This ROS-responsive system exhibits the following advantages:(1)It makes use of the“ELVIS”effect for passive delivery and targeting the ROS environment of RA-related cells to rapidly release the payload drugs DEX and PRI.(2)Compared with free drugs,DPTM showed stronger effect on the inhibition of RA-FLS proliferation and the promotion of RA-FLS apoptosis.Moreover,DPTM could significantly weaken the migration ability of RA-FLS as indicated by the results of wound healing assay and transwell assay.(3)DPTM exerted stronger cellular uptake and anti-inflammatory effect in M1 macrophages.(4)In the model studying receptor activator of nuclear factor kappa-B ligand(RANKL)-induced differentiation of bone marrow-derived macrophages(BMDMs)to osteoclasts,DPTM showed a stronger inhibitory activity on osteoclast formation as compared to free drugs.Taken together,these results highlighted the potential of DPTM for targeted RA therapy via inhibition of RA-FLS abnormal activation,macrophage polarization and osteoclastogenesis.展开更多
Osteoporosis is a serious public bone metabolic disease. However, the mechanisms underlying bone loss combined with ageing, which is known as senile osteoporosis, remains unknown. Here we show the detailed phenotype o...Osteoporosis is a serious public bone metabolic disease. However, the mechanisms underlying bone loss combined with ageing, which is known as senile osteoporosis, remains unknown. Here we show the detailed phenotype of this disease caused by SIRT6 knock out （KO） in mice. To the best of our knowledge, this is the first study to reveal that SIRT6 is expressed in both bone marrow stroma cells and bone-related cells in both mouse and human models, which suggests that SIRT6 is an important regulator in bone metabolism. SIRT6-KO mice exhibit a significant decrease in body weight and remarkable dwarfism. The skeleton of the SIRT6-KO mouse is deficient in cartilage and mineralized bone tissue. Moreover, the osteocalcin concentration in blood is lower, which suggests that bone mass is markedly lost. Besides, the tartrate-resistant acid phosphatase 5b （TRAP5b） concentration is much higher, which suggests that bone resorption is overactive. Both trabecular and cortical bones exhibit severe osteopenia, and the bone mineral density is decreased. Moreover, double-labelling analysis shows that bone formation is much slower. To determine whether SIRT6 directly regulates bone metabolism, we cultured primary bone marrow stromal cells for osteogenesis and osteoclastogenesis separately to avoid indirect interference in vivo responses such as inflammation. Taken together, these results show that SIRT6 can directly regulate osteoblast proliferation and differentiation, resulting in attenuation in mineralization. Furthermore, SIRT6 can directly regulate osteoclast differentiation and results in a higher number of small osteoclasts, which may be related to overactive bone resorption.展开更多
基金supported by grants from the National Natural Science Foundation of China(82404638)the Xingdian Talent Plan of Yunnan Province(XDYC-QNRC-2023-0427,XDYC-YLXZ 2022-0025)the Natural Science Foundation of Yunnan Province(202101BD070001-034,202101BD070001-049,202201AT070267,202201AU070183).
文摘Excessive osteoclastogenesis-mediated osteoporosis has been recognized as a global health concern.Candidate compounds derived from medicinal plants or functional foods are promising to treat osteoporosis due to their high safety and efficiency.(−)-Epigallocatechin-3-gallate(EGCG)is the most abundant and biologically active polyphenol in green tea.It can inhibit osteoclastogenesis in vitro by blocking receptor activator of nuclear factor(NF)-κB(RANK)signaling pathways.This study used the ovariectomized(OVX)mouse model to estimate the therapeutic effect of EGCG on osteoporosis and verified the molecular mechanism in vivo.The results revealed that EGCG significantly inhibited the OVX-induced body weight gain.Moreover,no adverse effects were observed on blood glucose,histomorphological features,weights,as well as indices of liver and kidney in OVX mice.EGCG could significantly ameliorate bone loss in OVX mice by inhibiting osteoclastogenesis.This effect was evidenced by the reduced number of osteoclasts and the increased trabecular bone area in the femurs.Moreover,EGCG inhibited the activities of c-telopeptide of type I collagen(CTX-I)and tartrate-resistant acid phosphatase 5b(TRACP-5b)and strengthened bone gla protein(BGP)and procollagen I N-terminal peptide(PINP)activities in OVX mice.Mechanistically,EGCG significantly downregulated the expression of osteoclastogenesis-related marker genes and proteins,including nuclear factor of activated T cells,cytoplasmic 1(NFATc1),c-Fos,tartrate-resistant acid phosphatase(TRAP),c-Src,and cathepsin K.In addition,the phosphorylation levels of p65,c-Jun N-terminal kinase(JNK),extracellular signal-regulated kinase 1/2(ERK1/2),p38,and protein kinase B(AKT)were significantly suppressed in OVX mice.It was found that EGCG could alleviate OVX-induced bone loss in mice by suppressing osteoclastogenesis by blocking the NF-κB,mitogen-activated protein kinase(MAPK),and AKT signaling pathways.EGCG has the potential to prevent and treat osteoclast-related diseases such as osteoporosis.
基金Supported by Guangdong Provincial Clinical Research Center for Orthopedic Diseases,No.2023B110001the Excellent Medical Innovation Talent Program of the Eighth Affiliated Hospital of Sun Yat-sen University,No.YXYXCXRC202101+3 种基金the National Natural Science Foundation of China,No.82172349,No.82372372,No.22105229,No.32170708,No.82102530,No.82102541,No.82103098,No.82103909,No.82104182,No.82104350,No.82170427,No.82171291,No.82172215,No.82172385,and No.82302661Guangdong Natural Science Foundation,No.2023A1515010568 and No.2021A1515111057Shenzhen Science and Technology Program,No.JCYJ20220530144201004 and No.RCBS20210609104445097Futian Healthcare Research Project,No.FTWS2022022,No.FTWS2021013,No.FTWS2023072,and No.FTWS2022047.
文摘BACKGROUND Ankylosing spondylitis(AS)is recognized as a long-term inflammatory disorder that leads to inflammation in the spine and joints,alongside abnormal bone growth.In previous studies,we reported that mesenchymal stem cells(MSCs)derived from individuals with AS demonstrated a remarkable inhibition in the formation of osteoclasts compared to those obtained from healthy donors.The mechanism through which MSCs from AS patients achieve this inhibition remains unclear.AIM To investigate the potential underlying mechanism by which MSCs from individuals with ankylosing spondylitis(AS-MSCs)inhibit osteoclastogenesis.METHODS We analysed fat mass and obesity-associated(FTO)protein levels in AS-MSCs and MSCs from healthy donors and investigated the effects and mechanism by which FTO in MSCs inhibits osteoclastogenesis by coculturing and measuring the levels of tartrate-resistant acid phosphatase,nuclear factor of activated T cells 1 and cathepsin K.RESULTS We found that FTO,an enzyme responsible for removing methyl groups from RNA,was more abundantly expressed in MSCs from AS patients than in those from healthy donors.Reducing FTO levels was shown to diminish the capacity of MSCs to inhibit osteoclast development.Further experimental results revealed that FTO affects the stability of the long non-coding RNA activated by DNA damage(NORAD)by altering its N6-methyladenosine methylation status.Deactivating NORAD in MSCs significantly increased osteoclast formation by affecting miR-4284,which could regulate the MSC-mediated inhibition of osteoclastogenesis reported in our previous research.CONCLUSION This study revealed elevated FTO levels in AS-MSCs and found that FTO regulated the ability of AS-MSCs to inhibit osteoclast formation through the long noncoding RNA NORAD/miR-4284 axis.
基金supported by the grants from the National Natural Science Foundation of China(82404638)the Xingdian Talent Plan of Yunnan Province(XDYC-QNRC-2023-0427 and XDYC-YLXZ2022-0025)the Natural Science Foundation of Yunnan Province(202101BD070001-034,202101BD070001-049,202201AT070267,and 202201AU070183)。
文摘Steroidal alkaloids are the main active components in many medicinal plants and exhibit diverse biological activities.Axillaridine A(AA)is a newly discovered steroidal alkaloid.However,whether AA could suppress osteoclastogenesis and alleviate ovariectomy-induced bone loss in mice remains unknown.In vitro,AA significantly suppressed the receptor activator of nuclear factor-κB(NF-κB)ligand(RANKL)-induced osteoclast differentiation via downregulating the expression of osteoclastogenesis-related marker genes,proteins,and transcriptional regulators,including tartrate-resistant acid phosphatase(TRAP),c-Src,matrix metallopeptidase-9(MMP-9),cathepsin K,nuclear factor of activated T cells,cytoplasmic 1(NFATc1),and c-Fos.This was achieved by blocking RANKL-RANK interaction and inhibiting RANKL-mediated RANK signaling pathways,including NF-κB,AKT,and mitogen-activated protein kinases(MAPKs)in osteoclast precursors.In vivo,AA significantly inhibited the ovariectomized(OVX)-induced body weight gain and blood glucose increase in mice.AA did not adversely affect the histomorphologies,weights,and indices of the kidney and liver in OVX mice.AA effectively ameliorated bone loss in OVX mice by inhibiting osteoclastogenesis.AA significantly inhibited the serum levels of tartrate-resistant acid phosphatase 5b(TRACP-5b)and C-telopeptide of type I collagen(CTX-I).AA significantly inhibited the OVX-induced expression of osteoclastogenesis-related marker genes and proteins in the femur.In summary,AA alleviates ovariectomy-induced bone loss in mice by suppressing osteoclastogenesis via inhibition of RANKL-mediated RANK signaling pathways and could be potentially used for the prevention and treatment of osteoclastrelated diseases such as osteoporosis.
基金supported by grants from the National Natural Science Foundation of China(Nos.81572639,81370969 and 81072190 to X Yu)the Ministry of Education of the People's Republic of China(No.20130181110066 to X Yu)the Chengdu Bureau of Science and Technology(No.2014-HM01-00382-SF to X Yu)
文摘Type II autosomal dominant osteopetrosis(ADO2), which is the most common form of osteopetrosis, is caused by heterozygous mutations in the chloride channel 7(CLCN7) gene. The osteopetrosis of ADO2 has been attributed to hypofunctional osteoclasts. The mechanism underlying the abnormality in osteoclast function remains largely unknown. This study was designed to investigate gene mutations and osteoclast function in a case that was clinically diagnosed as ADO2. Genomic DNA was extracted from blood samples of this patient, and the 25 exons of CLCN7 were amplified. Peripheral blood from the ADO2 subject and a healthy age- and sex-matched control was used to evaluate osteoclastogenesis, osteoclast morphology, and bone resorption. Analysis of DNA from the patient showed a germline heterozygous missense mutation,c.1856C>T(p.P619L), in exon 20 of CLCN7. A similar homozygous mutation at this site was previously reported in a patient with autosomal recessive osteopetrosis. When cultured, the peripheral blood mononuclear cells(PBMCs) from the ADO2 patient spontaneously differentiated into mature osteoclasts in vitro. The ADO2 patient’s PBMCs formed enhanced, but heterogeneous, osteoclasts in both the presence and absence of macrophage-colony stimulating factor, and nuclear factor-?B ligand. Bone resorption was reduced in the ADO2 patient’s osteoclasts, which exhibited aberrant morphology and abnormal distribution of integrin avβ3. Gene analysis found increased c-fos expression and reduced Rho A and integrin beta 3expression in ADO2 cells. In conclusion, our data suggest that enhanced, heterogeneous osteoclast induction may be an intrinsic characteristic of ADO2.
文摘Bone remodeling is performed under the joint action of osteoblasts and osteoclasts. Since the effect of osteoclasts has been gradually recognized on bone and joint diseases, targeted researches toward osteoclasts have become a hot research field. This article reviews the relevant medical literature concerning the possible effects of the fluid shear stress (FSS) on the osteoclastogenesis chiefly from the aspects of RANKL-RANK-OPG system, the macrophage colony-stimulating factor (M-CSF), and calcitonin receptor (CTR). On the basis of the changes of the expression of osteoclastic activities, it is suggested that FSS is a potent, important regulator of bone metabolism.
文摘Green tea catechin, (–)-epigallocatechin-3-gallate [(–)-EGCG], was found to increase osteogenic functioning in mesenchymal stem cells. This study qualified EGCG, the strongest inhibitory efficiency for receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL)-activated osteoclastogenesis among other green tea catechins for RAW264, a murine preosteoclast cell line. Moreover, EGCG inhibited tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cell formation dose dependently in both single culture and co-culture systems, the expression of transcription factor, nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) and some osteoclastic genes. Especially, EGCG exhibited a strong inhibitory effect on the expression levels of RANK, the receptor of RANKL, and OSCAR, a key co-stimulator of the RANKL/RANK signal. Simultaneously, apoptotic genes expression and Hoechst staining revealed that EGCG induced apoptosis in RAW264. Taken together, these data suggest that the inhibitory effect of EGCG to osteoclastogenesis is associated with a down regulation of RANKL/RANK signal, and increased apoptosis of preosteoclasts.
基金supported by the Guangxi Science and Technology Key Research and Development Program(no.AB16450012).
文摘Breast cancer(BC)often spreads to bones,leading to bone metastasis(BM).Current targeted therapies have limited effectiveness in the treatment of this condition.Osteoclasts,which contribute to bone destruction,are crucial in supporting tumor cell growth in the bones.Breast cancer bone metastasis(BCBM)treatments have limited efficacy and can cause adverse effects.Ononin exhibits anticancer properties against various cancers.The study examined the impact of ononin on the BCBM and the signaling pathways involved.Our study utilized a variety of experimental techniques,including cell viability assays,colony formation assays,wound-healing assays,Transwell migration assays,Western blot analysis,and tartrate-resistant acid phosphatase(TRAP)staining.We examined the effects of ononin on osteoclastogenesis induced in MDA-MB-231 conditioned medium-and RANKL-treated RAW 264.7 cells.In a mouse model of BCBM,ononin reduced tumor-induced bone destruction.Ononin treatment effectively inhibited proliferation and colony formation and reduced the metastatic capabilities of MDA-MB-231 cells by suppressing cell adhesion,invasiveness,and motility and reversing epithelial–mesenchymal transition(EMT)markers.Ononin markedly suppressed osteoclast formation and osteolysis-associated factors in MDA-MB-231 cells,as well as blocked the activation of the mitogen-activated protein kinase(MAPK)pathway in RAW 264.7 cells.Ononin treatment down-regulated the phosphorylation of MAPK signaling pathways,as confirmed using MAPK agonists or inhibitors.Ononin treatment had no adverse effects on the organ function.Our findings suggest that ononin has therapeutic potential as a BCBM treatment by targeting the MAPK pathway.
基金the Key Program of National Natural Science Foundation of China(81930067)the Youth Program of National Natural Science Foundation of China(grant number 82002316)+1 种基金the Youth Cultivation Project of Army Medical University(2020XQN08)General Program of Natural Science Foundation of Chongqing(cstc2019jcyj-msxmX0176).
文摘Osteoporosis is caused by an osteoclast activation mechanism.People suffering from osteoporosis are prone to bone defects.Increasing evidence indicates that scavenging reactive oxygen species(ROS)can inhibit receptor activator of nuclear factorκB ligand(RANKL)-induced osteoclastogenesis and suppress ovariectomy-induced osteoporosis.It is critical to develop biomaterials with antioxidant properties to modulate osteoclast activity for treating osteoporotic bone defects.Previous studies have shown that manganese(Mn)can improve bone regeneration,and Mn supplementation may treat osteoporosis.However,the effect of Mn on osteoclasts and the role of Mn in osteoporotic bone defects remain unclear.In present research,a model bioceramic,Mn-containedβ-tricalcium phosphate(Mn-TCP)was prepared by introducing Mn intoβ-TCP.The introduction of Mn intoβ-TCP significantly improved the scavenging of oxygen radicals and nitrogen radicals,demonstrating that Mn-TCP bioceramics might have antioxidant properties.The in vitro and in vivo findings revealed that Mn^(2+)ions released from Mn-TCP bioceramics could distinctly inhibit the formation and function of osteoclasts,promote the differentiation of osteoblasts,and accelerate bone regeneration under osteoporotic conditions in vivo.Mechanistically,Mn-TCP bioceramics inhibited osteoclastogenesis and promoted the regeneration of osteoporotic bone defects by scavenging ROS via Nrf2 activation.These results suggest that Mn-containing bioceramics with osteoconductivity,ROS scavenging and bone resorption inhibition abilities may be an ideal biomaterial for the treatment of osteoporotic bone defect.
基金This work was supported by the grants from Jiangsu Province Key Medical Center （No. ZX200608）, the National Nature Science Foundation of China （No. 30672140, No. 81071451）, the Colleges and Universities Natural Science Foundation in Jiangsu Province （No. 10KJB320019）, the Key Project Surpported by the Medical Science and Technology Department Foundation, Jiangsu Province, Department of Health （No. H201012） and the Social Development Projects in Suzhou （No. SS08020）.
文摘Background The cannabinoid receptor-2 （CB2） is important for bone remodeling. In this study, we investigated the effects of CB2 selective antagonist （AM630） on receptor activator of nuclear factor kappa B （RANK） ligand （RANKL）induced osteoclast differentiation and the underlying signaling pathway using a monocyte-macrophage cell line-RAW264.7.Methods RAW264.7 was cultured with RANKL for 6 days and then treated with AM630 for 24 hours. Mature osteoclasts were measured by tartrate-resistant acid phosphatase （TRAP） staining using a commercial kit. Total ribonucleic acid （RNA）was isolated and real-time reverse transcriptase-polymerase chain reaction （RT-PCR） was done to examine the expression of RANK, cathepsin K （CPK） and nuclear factor kappa B （NF-κB）. The extracellular signal-regulated kinase （ERK）,phosphorylation of ERK （P-ERK） and NF-κB production were tested by Western blotting. The effect of AM630 on RAW264.7 viability was determined using the 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazoliumbromide （MTT） assay.Results AM630 did not affect the viability of RAW264.7. However, this CB2 selective antagonist markedly inhibited osteoclast formation and the inhibition rate was dose-dependent. The dose of 〉100 nmol/L could reduce TRAP positive cells to the levels that were significantly lower than the control. AM630 suppressed the expression of genes associated with osteoclast differentiation and activation, such as RANK and CPK. An analysis of a signaling pathway showed that AM630 inhibited the RANKL-induced activation of ERK, but not NF-κB.Conclusion AM630 could inhibit the osteoclastogenesis from RAW264.7 induced with RANKL.
基金supported by National Natural Science Foundation of China(81530051,31800790 and 32071324)Young Talent Fund of University Association for Science and Technology in Shaanxi,China(20190304).
文摘Macrophages and osteoclasts are both derived from monocyte/macrophage lineage,which plays as the osteoclastic part of bone metabolism.Although they are regulated by bone implant surface nanoarchitecture and involved in osseointegration,the beneath mechanism has not been simultaneously analyzed in a given surface model and their communication with osteoblasts is also blurring.Here,the effect of implant surface topography on monocyte/macrophage lineage osteoclastogenesis and the subsequent effect on osteogenesis are systematically investigated.The nanoporous surface is fabricated on titanium implant by etching and anodizing to get the nanotubes structure.The early bone formation around implant is significantly accelerated by the nanoporous surface in vivo.Meanwhile,the macrophage recruitment and osteoclast formation are increased and decreased respectively.Mechanistically,the integrin mediated FAK phosphorylation and its downstream MAPK pathway(p-p38)are significantly downregulated by the nanoporous surface,which account for the inhibition of osteoclastogenesis.In addition,the nanoporous surface can alleviate the inhibition of osteoclasts on osteogenesis by changing the secretion of clastokines,and accelerate bone regeneration by macrophage cytokine profiles.In conclusion,these data indicate that physical topography of implant surface is a critical factor modulating monocyte/macrophage lineage commitment,which provides theoretical guidance and mechanism basis for promoting osseointegration by coupling the osteogenesis and osteoclastogenesis.
基金funded by National Key Research and Development Program of China(No.2016YFC1102900)National Natural Science Foundation of China(No.51772100 and No.32171342)+2 种基金Shanghai Science and Technology Agriculture Project(No.202002080002F01474)Shanghai Pujiang Program(16PJD015)Joint Fund for equipment pre-research of the ministry of education(6141A02022618).
文摘Osteoporosis is a reduction in skeletal mass due to the decrease of osteogenic ability and the activation of the osteoclastic function.Inhibiting bone resorption and accelerating the new bone formation is a promising strategy to repair the bone defect of osteoporosis.In this study,we first systematically investigated the roles of Chinese medicine Asperosaponin Ⅵ(ASP Ⅵ)on osteogenic mineralization of BMSCs and osteoclastogenesis of BMMs,and then explored the synergistic effect of ASP Ⅵ and BS(BMP-2 immobilized in 2-N,6-O-sulfated chitosan)on bone formation.The result showed that ASP Ⅵ with the concentration lower than 10^(-4) M contributed to the expression of osteogenic gene and inhibited osteoclastic genes RANKL of BMSCs.Simultaneously,ASP Ⅵ significantly reduced the differentiation of mononuclear osteoclasts in the process of osteoclast formation induced by M-CSF and RANKL.Furthermore,by stimulating the SMADs,TGF-β1,VEGFA,and OPG/RANKL signaling pathways,ASBS(ASP Ⅵ and BS)substantially enhanced osteogenesis,greatly promoted angiogenesis,and suppressed osteoclastogenesis.The findings provide a new perspective on osteoporosis care and prevention.
基金Our study was financially supported by the National Natural Science Fundation for Youth of China(Nos.81802136)the Natural Science Fundation for Youth of Hunan Province(Nos.2020JJ5939)+2 种基金the Postdoctoral Science Fundation of China(Nos.2018M643005)the National Natural Science Fundation of China(Nos.52172265)the Science Fundation for Youth of Xiangya Hospital,Central South University(Nos.2017Q18).
文摘Currently,implant-associated bacterial infections account for most hospital-acquired infections in patients suffering from bone fractures or defects.Poor osseointegration and aggravated osteolysis remain great challenges for the success of implants in infectious scenarios.Consequently,developing an effective surface modification strategy for implants is urgently needed.Here,a novel nanoplatform(GO/Ga)consisting of graphene oxide(GO)and gallium nanoparticles(GaNPs)was reported,followed by investigations of its in vitro antibacterial activity and potential bacterium inactivation mechanisms,cytocompatibility and regulatory actions on osteoblastogenesis and osteoclastogenesis.In addition,the possible molecular mechanisms underlying the regulatory effects of GO/Ga nanocomposites on osteoblast differentiation and osteoclast formation were clarified.Moreover,an in vivo infectious microenvironment was established in a rat model of implant-related femoral osteomyelitis to determine the therapeutic efficacy and biosafety of GO/Ga nanocomposites.Our results indicate that GO/Ga nanocomposites with excellent antibacterial potency have evident osteogenic potential and inhibitory effects on osteoclast differentiation by modulating the BMP/Smad,MAPK and NF-κB signaling pathways.The in vivo experiments revealed that the administration of GO/Ga nanocomposites significantly inhibited bone infections,reduced osteolysis,promoted osseointegration located in implant-bone interfaces,and resulted in satisfactory biocompatibility.In summary,this synergistic therapeutic system could accelerate the bone healing process in implant-associated infections and can significantly guide the future surface modification of implants used in bacteria-infected environments.
基金funded by China Postdoctoral Science Foundation(2021M692249)National Key R&D Program of China 2017YFC1104304(YB)+1 种基金National Natural Science Foundation of China grant 82071144,Shanghai Rising-Star Program(21QA1405400)Innovative research team of high-level local universities in Shanghai(SSMU-ZDCX20180900).
文摘We has synthesized the biocompatible gelatin reduced graphene oxide(GOG)in previous research,and in this study we would further evaluate its effects on bone remodeling in the aspects of osteoclastogenesis and angiogenesis so as to verify its impact on accelerating orthodontic tooth movement.The mouse orthodontic tooth movement(OTM)model tests in vivo showed that the tooth movement was accelerated in the GOG local injection group with more osteoclastic bone resorption and neovascularization compared with the PBS injection group.The analysis on the degradation of GOG in bone marrow stromal stem cells(BMSCs)illustrated its good biocompatibility in vitro and the accumulation of GOG in spleen after local injection of GOG around the teeth in OTM model in vivo also didn’t influence the survival and life of animals.The co-culture of BMSCs with hematopoietic stem cells(HSCs)or human umbilical vein endothelial cells(HUVECs)in transwell chamber systems were constructed to test the effects of GOG stimulated BMSCs on osteoclastogenesis and angiogenesis in vitro.With the GOG stimulated BMSCs co-culture in upper chamber of transwell,the HSCs in lower chamber manifested the enhanced osteoclastogenesis.Meanwhile,the co-culture of GOG stimulated BMSCs with HUVECs showed a promotive effect on the angiogenic ability of HUVECs.The mechanism analysis on the biofunctions of the GOG stimulated BMSCs illustrated the important regulatory effects of PERK pathway on osteoclastogenesis and angiogenesis.All the results showed the biosecurity of GOG and the biological functions of GOG stimulated BMSCs in accelerating bone remodeling and tooth movement.
基金This study was funded by Beijing Natural Science Foundation
文摘Background： Calpain, a calcium-dependent cysteine protease, has been demonstrated to regulate osteoclastogenesis, which is considered one of the major reasons for cancer-induced bone pain （CIBP）. In the present study, calpain inhibitor was applied in a rat CIBP model to determine whether it could reduce CIBP through regulation of osteoclastogenesis activity. Methods： A rat CIBP model was established with intratibial injection of Walker 256 cells. Then, the efficacy of intraperitoneal administered calpain inhibitor III （MDL28170, 1 mg/kg） on mechanical withdrawal threshold （MWT） of bilateral hind paws was examined on postoperative days （PODs） 2, 5, 8, 11, and 14. On POD 14, the calpain inhibitor＇s effect on tumor bone tartrate-resistant acid phosphatase （TRAP） stain and radiology was also carefully investigated. Results： Pain behavioral tests in rats showed that the calpain inhibitor effectively attenuated MWTs of both the surgical side and contralateral side hind paws on POD 5, 8, and 11 （P 〈 0.05）. TRAP-positive cell count of the surgical side bone was significantly decreased in the calpain inhibitor group compared with the vehicle group （P 〈 0.05）. However, bone resorption and destruction measured by radiographs showed no difference between the two groups. Conclusions： Calpain inhibitor can effectively reduce CIBP of both the surgical side and nonsurgical side after tumor injection in a rat CIBP model. It may be due to the inhibition of receptor activator of nuclear factor-kappa B ligand-induced osteoclastogenesis. Whether a calpain inhibitor could be a novel therapeutic target to treat CIBP needs further investigation.
基金This work was financially supported by the National Natural Science Foundation of China （No.11372351, No.31370942, No.81160223）, and Scientific Research Foundation of Guangxi Higher Education （No.KY2015LX241）.
文摘Purpose： To investigate the influence of the same mechanical loading on osteogenesis and osteoclastogenesis in vitro. Methods： Primary osteoblasts, bone marrow-derived mesenchymal stem cells （BMSCs, cultured in osteoinductive medium） and RAW264.7 cells cultured in osteoclast inductive medium were all subjected to a 1000μstrain （μs） at 1 Hz cyclic mechanical stretch for 30 min （twice a day）. Results： After mechanical stimulation, the alkaline phosphatase （ALP） activity, osteocalcin protein level of the osteoblasts and BMSCs were all enhanced, and the mRNA levels of ALP and collagen type I increased. Additionally, extracellular-deposited calcium of both osteoblasts and BMSCs increased. At the same time, the activity of secreted tartrate-resistant acid phosphatase, the number of tartrate-resistant acid phosphatase-positive multinucleated cells, matrix metalloproteinase-9 protein levels of RAW264.7 cells and the extracellular calcium solvency all decreased. Conclusion： The results demonstrated that 1000 μs cyclic mechanical loading enhanced osteoblasts activity, promoted osteoblastic differentiation of BMSCs and restrained osteoclastogenesis of RAW264.7 cells in vitro.
基金supported by the National Natural Science Foundation of China(Nos.22305042(Tiancong Zhao),22075049(Xiaomin Li),21875043(Xiaomin Li),82201748(Xiaomin Li))the Fundamental Research Funds for the Central Universities(No.20720220010(Xiaomin Li))+3 种基金the Natural Science Foundation of Shanghai(No.22ZR1478900(Xiaomin Li))the Shanghai Rising-Star Program(Nos.20QA1401200(Xiaomin Li),22YF1402200(Tiancong Zhao),21YF1459200(Xiaomin Li))Shanghai Pilot Program for Basic Research-Fudan University(No.22TQ004)Young Elite Scientist Sponsorship Program by Chinese Chemical Society(Tiancong Zhao),Xiaomi Young Talents Program(Tiancong Zhao),Qatar Research Development and Innovation Council(No.ARG01-0602-230467).
文摘The excessive reactive oxygen species (ROS) accumulation and overactivated osteoclastogenesis in subchondral bone has proved to be a major cause of osteoarthritis (OA). Scavenging of ROS microenvironment to inhibit the osteoclastogenesis is highly valued in the therapeutic process of osteoarthritis. Despite the excellent ability of polyphenolic colloidal to scavenge reactive oxygen species and its affinity for macrophages, the preparation of polyphenolic colloidal nanoparticles is limited by the complex intermolecular forces between phenol molecules and the lack of understanding of polymerization/sol-gel chemistry. Herein, our work introduces a novel poly-tannin-phenylboronic colloidal nanoparticle (PTA) exclusively linked by ROS-responsive bondings. Nanocolloidal PTA has a uniform particle size, is easy and scalable to synthesize, has excellent scavenging of ROS, and can be slowly degraded. For in vitro experiments, we demonstrated that, PTA could eliminate ROS within RAW264.7 cells and impede osteoclastogenesis and bone resorption. RNA sequencing results of PTA-treated RAW264.7 cells further reveal the promotion of antioxidant activity and inhibition of osteoclastogenesis. For in vivo experiments, PTA could eliminate the ROS environment and reduce the number of osteoclasts in the subchondral bone, thereby alleviating the damage of subchondral bone and symptoms of osteoarthritis. Our research, by delving into the formation of polyphenol colloidal nanoparticles and validating their role in ROS scavenging to inhibit osteoclastogenesis in subchondral bone, may open new avenues for OA treatment in the future.
基金National Natural Science Foundation of China(82272165)Shanghai Municipal Commission of Health and Family Planning’s Science and Research Fund(202040141)+2 种基金Shanghai Municipality Science and Technology Commission(20ZR1451800,22ZR1457200)Shanghai Municipal Health Commission(2022YQ006)Shanghai Tongren Hospital(TRKYRC-xx202203).
文摘Inflammation can initiate osteolysis,which is the breakdown of bone by fully developed osteoclasts.The com-pound Oleandrin is recognized for its effects against inflammation and tumors.Our objective was to examine the effects of Oleandrin on osteoclastogenesis and osteolysis,both in vitro and in vivo.In vitro,the impact of Oleandrin on osteoclastogenesis was assessed using CCK-8 assays,TRAP staining,and bone resorption assays.Ad-ditionally,a mouse model of osteolysis caused by LPS injection into the calvaria was used to conduct an in vivo investigation,examining bone histomorphology,histology,and immunohistochemistry.In vitro,concentrations of 5 nM and 10 nM of Oleandrin were found to be non-cytotoxic based on the results obtained.In vitro,Olean-drin hindered the osteoclastogenesis and bone resorption induced by RANKL.Oleandrin successfully inhibited the phosphorylation of NF-κB p65 and PI3K p85 in osteolytic tissue,thereby suppressing LPS-induced inflammatory osteolysis in mice calvaria during the in vivo study.Furthermore,the Oleandrin-treated group exhibited a note-worthy decrease in the expression level of NFATc1,which is a crucial controller of osteoclastogenesis.To sum up,our discoveries indicate that Oleandrin could hinder osteoclastogenesis and bone resorption,thereby having the ability to suppress inflammation-induced osteolysis.The underlying mechanism involves the NF-κB/PI3K pathway and inhibition of NFATc1 activation.Therefore,the findings suggest that Oleandrin holds potential as a therapeutic remedy for osteolytic ailments.
基金supported by grants from the National Natural Science Foundation of China(Nos.81572852 and 82104671)the Great Program of the Science Foundation of Tianjin(No.18JCZDJC33200)+1 种基金Heilongjiang Province Fund(No.LH2020H102)Tianjin Key Medical Discipline(Specialty)Construction Project(No.TJYXZDXK-032A)。
文摘This study investigated the regulatory potential of salidroside(SAL),a primary active compound in Rhodiola rosea L.,on osteoclast differentiation by modulating the hypoxia-inducible factor 1-alpha(HIF-1α)pathway in osteoblasts.Luciferase reporter assay and chromatin immunoprecipitation(Ch IP)assay were employed to validate whether the receptor activator of nuclear factor-κB ligand(RANKL)is the downstream target gene of HIF-1αin osteoblasts.The study also utilized lipopolysaccharide(LPS)-induced mouse osteolysis to examine the impact of SAL on osteolysis in vivo.Furthermore,conditioned medium(CM)from SAL-pretreated osteoblasts was used to investigate the paracrine effects on osteoclastogenesis through the HIF-1αpathway.Hypoxic condition-induced overexpression of HIF-1αupregulated RANKL levels by binding to the RANKL promoter and enhancing transcription in osteoblastic cells.In vivo,SAL significantly alleviated bone tissue hypoxia and decreased the expression of HIF-1αby downregulating the expression of RANKL,vascular endothelial growth factor(VEGF),interleukin 6(IL-6),and angiopoietin-like 4(ANGPTL4).In the paracrine experiment,conditioned media from SAL-pretreated osteoblasts inhibited differentiation through the HIF-1α/RANKL,VEGF,IL-6,and ANGPTL4 pathways.RANKL emerges as the downstream target gene regulated by HIF-1αin osteoblasts.SAL significantly alleviates bone tissue hypoxia and bone loss in LPS-induced osteolysis through the HIF-1α/RANKL,VEGF,IL-6,and ANGPTL4 pathways.SAL inhibits osteoclast differentiation by regulating osteoblast paracrine secretion.
基金supported by the National Natural Science Foundation of China(No.82204724)the Science and Technology Development Fund,Macao SAR(Nos.0029/2023/AFJ,005/2023/SKL)+1 种基金the Multi-Year Research Grant(MYRG)of University of Macao(Nos.MYRG2022-00203-ICMS,MYRG-GRG2023-00134-ICMS-UMDF)Macao Young Scholars Program(No.AM2022019)。
文摘Invasive fibroblast-like synoviocytes(FLS),inflammatory macrophages and osteoclasts are the main three contributors to rheumatoid arthritis(RA)progression by promoting synovial inflammation and destructing cartilage and bone.Targeting these three cell types for restoring the inflammatory homeostasis microenvironment may be a promising anti-RA strategy.Herein,we prepared a reactive oxygen species(ROS)-responsive micelles(DPTM)to co-load dexamethasone(DEX)and pristimerin(PRI)for RA therapy.This ROS-responsive system exhibits the following advantages:(1)It makes use of the“ELVIS”effect for passive delivery and targeting the ROS environment of RA-related cells to rapidly release the payload drugs DEX and PRI.(2)Compared with free drugs,DPTM showed stronger effect on the inhibition of RA-FLS proliferation and the promotion of RA-FLS apoptosis.Moreover,DPTM could significantly weaken the migration ability of RA-FLS as indicated by the results of wound healing assay and transwell assay.(3)DPTM exerted stronger cellular uptake and anti-inflammatory effect in M1 macrophages.(4)In the model studying receptor activator of nuclear factor kappa-B ligand(RANKL)-induced differentiation of bone marrow-derived macrophages(BMDMs)to osteoclasts,DPTM showed a stronger inhibitory activity on osteoclast formation as compared to free drugs.Taken together,these results highlighted the potential of DPTM for targeted RA therapy via inhibition of RA-FLS abnormal activation,macrophage polarization and osteoclastogenesis.
基金supported by NSFC grants 81371136 and JCPT2011-9 (Xue-Dong Zhou),NSFC grants 81470711 and 81200760 (Li-Wei Zheng)Ling Ye (Professor, Sate Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University) for financial aid
文摘Osteoporosis is a serious public bone metabolic disease. However, the mechanisms underlying bone loss combined with ageing, which is known as senile osteoporosis, remains unknown. Here we show the detailed phenotype of this disease caused by SIRT6 knock out （KO） in mice. To the best of our knowledge, this is the first study to reveal that SIRT6 is expressed in both bone marrow stroma cells and bone-related cells in both mouse and human models, which suggests that SIRT6 is an important regulator in bone metabolism. SIRT6-KO mice exhibit a significant decrease in body weight and remarkable dwarfism. The skeleton of the SIRT6-KO mouse is deficient in cartilage and mineralized bone tissue. Moreover, the osteocalcin concentration in blood is lower, which suggests that bone mass is markedly lost. Besides, the tartrate-resistant acid phosphatase 5b （TRAP5b） concentration is much higher, which suggests that bone resorption is overactive. Both trabecular and cortical bones exhibit severe osteopenia, and the bone mineral density is decreased. Moreover, double-labelling analysis shows that bone formation is much slower. To determine whether SIRT6 directly regulates bone metabolism, we cultured primary bone marrow stromal cells for osteogenesis and osteoclastogenesis separately to avoid indirect interference in vivo responses such as inflammation. Taken together, these results show that SIRT6 can directly regulate osteoblast proliferation and differentiation, resulting in attenuation in mineralization. Furthermore, SIRT6 can directly regulate osteoclast differentiation and results in a higher number of small osteoclasts, which may be related to overactive bone resorption.
