Search Results (1,318)

Background: Osteoporosis is characterized by the microstructural depletion of bone tissue and decreased bone density, leading to an increased risk of fractures. Cotoneaster wilsonii Nakai, an endemic species of the Korean Peninsula, grows wild in Ulleungdo. In this study, we aimed to investigate the effects of C. wilsonii and its components on osteoporosis. Methods and Results: The alkaline phosphatase (ALP) activity of C. wilsonii extracts and fractions was evaluated in MC3T3-E1 pre-osteoblasts, and the n-hexane fraction (CWH) showed the best properties for ALP activity. The effects of the CWH on bone formation were assessed in MC3T3-E1 cells and ovariectomized mice. Biochemical assays and histological analyses focused on the signaling activation of osteoblast differentiation and osteogenic markers, such as ALP, collagen, and osterix. The CWH significantly activated TGF-β and Wnt signaling, enhancing osteoblast differentiation and bone matrix formation. Notably, CWH treatment improved micro-CT indices, such as femoral bone density, and restored serum osteocalcin levels compared to OVX controls. Conclusions: These results highlight the potential of the C. wilsonii Nakai n-hexane fraction as a promising therapeutic agent for managing osteoporosis. Full article

Bone defects restoration has always been an arduous challenge in the orthopedic field due to the limitations of conventional grafts. Bone tissue engineering offers an alternative approach by using biomimetic materials, stem cells, and growth factors that are able to improve the regeneration of bone tissue. Different biomaterials have attracted great interest in BTE applications, including the poly(3-hexylthiofene) (P3HT) conductive polymer, whose primary advantage is its capability to provide a native extracellular matrix-like environment. Based on this evidence, in this study, we evaluated the biological response of human adipose-derived mesenchymal stem cells cultured on P3HT thin polymer film for 14 days. Our results suggest that P3HT represents a good substrate to induce osteogenic differentiation of osteoprogenitor cells, even in the absence of specific inductive growth factors, thus representing a promising strategy for bone regenerative medicine. Therefore, the system provided may offer an innovative platform for next-generation biocompatible materials for regenerative medicine. Full article

Inflammation significantly influences cellular communication in the oral environment, impacting tissue repair and regeneration. This study explores the role of small extracellular vesicles (sEVs) derived from lipopolysaccharide (LPS)-treated stem cells from the apical papilla (SCAP) in modulating macrophage polarization and osteoblast differentiation. SCAPs were treated with LPS for 24 h, and sEVs from untreated (SCAP-sEVs) and LPS-treated SCAP (LPS-SCAP-sEVs) were isolated via ultracentrifugation and characterized using transmission electron microscopy, Western blot, and Tunable Resistive Pulse Sensing. LPS-SCAP-sEVs exhibited characteristic exosome morphology (~100 nm diameter) and expressed vesicular markers (CD9, CD63, CD81, and HSP70). Functional analysis revealed that LPS-SCAP-sEVs promoted M1 macrophage polarization, as evidenced by the increased pro-inflammatory cytokines (IL-6 and IL-1β) and the reduced anti-inflammatory markers (IL-10 and CD206), while impairing the M2 phenotype. Additionally, LPS-SCAP-sEVs had a minimal impact on SCAP metabolic activity or osteogenic gene expression but significantly reduced mineralization capacity in osteogenic conditions. These findings suggest that sEVs mediate the inflammatory interplay between SCAP and macrophages, skewing macrophage polarization toward a pro-inflammatory state and hindering osteoblast differentiation. Understanding this sEV-driven communication axis provides novel insights into the cellular mechanisms underlying inflammation in oral tissues and highlights potential therapeutic targets for modulating extracellular vesicle activity during acute inflammatory episodes. Full article

The present study explored the possible antiobesogenic and osteoprotective properties of the gut metabolite ginsenoside CK to clarify its influence on lipid and atherosclerosis pathways, thereby validating previously published hypotheses. These hypotheses were validated by harvesting and cultivating 3T3-L1 and MC3T3-E1 in adipogenic and osteogenic media with varying concentrations of CK. We assessed the differentiation of adipocytes and osteoblasts in these cell lines by applying the most effective doses of CK that we initially selected. Using 3T3-L1 adipocytes in vitro assessments, CK could effectively decrease intracellular lipid accumulation, inhibit α-glucosidase enzyme, increase 2-NBDG glucose uptake, reduce inflammation-associated cytokines (TNFα, and IL-6), adipogenic regulatory genes (PPARγ, FAS, C/EBPα), lipogenic gene LPL, and increase the expression of thermogenic gene UCP1. Additionally, CK treatment induced osteoblast development in MC3T3-E1 cells as shown by increased mineralization and calcium distribution, collagen content, alkaline phosphatase activity, and decreased inflammatory cytokines TNFα, and IL-6 and increased the regulated expressions of osteogenic genes including Runx2, ALP, BGLAP, OCN, and Col1a1. Significantly, as a major inhibitory regulator, the TP⁵³ gene was down-regulated in both 3T3-L1 and MC3T3E1 cells after the treatment of CK. These encouraging results demonstrate the possible use of CK as an innovative treatment for controlling obesity and osteoporosis, targeting the underlying mechanisms of obesogenic and bone loss. Further studies are necessary to explore the clinical implications of these results and the potential of CK in future treatment strategies. This research highlights the promise of CK in addressing significant health issues. Full article

β-tricalcium phosphate (β-TCP) is a widely utilized resorbable bone graft material, whose surface charge can be modified by electrical polarization. However, the specific effects of such a charge modification on osteoblast and osteoclast functions remain insufficiently studied. In this work, electrically polarized β-TCP with a high surface charge density was synthesized and evaluated in vitro in terms of its physicochemical properties and biological activity. Polarization was performed to achieve a high surface charge density, which was quantified using a thermally stimulated depolarization current. The proliferation and differentiation of MC3T3-E1 osteoblast-like cells were assessed via WST-8 and alkaline phosphatase assays. Tartrate-resistant acid phosphatase (TRAP) activity and a resorption pit assay were used to evaluate the impact of surface charge on RAW264.7 osteoclast-like cell activity. Polarized β-TCP exhibited a surface charge of 1.3 mC cm⁻². Electrically polarized surfaces significantly enhanced osteoblast proliferation and differentiation. TRAP activity assays demonstrated effective osteoclast differentiation of RAW264.7 cells, with enhanced activity observed on charged surfaces. Resorption pit assays further revealed improved osteoclast resorption capacity on β-TCP surfaces with a polarized charge. These findings indicate that β-TCP with a highly dense surface charge promotes osteoblast proliferation and differentiation, as well as osteoclast activity and resorption capacity. Full article

Farnesoid X receptor (FXR), a nuclear receptor, is expressed in calvaria and bone marrow stromal cells and plays a role in bone homeostasis. However, the mechanism of FXR-activated osteoblast differentiation remains unclear. In this study, we investigated the regulatory mechanism underlying FXR-activated osteoblast differentiation using bone morphogenetic protein-2 (BMP-2)-induced mouse ST-2 mesenchymal stem cells. We also synthesized a novel FXR agonist, FLG390, and compared its biological effects in osteoblast differentiation with a known FXR agonist, chenodeoxycholic acid (CDCA). As an FXR agonist, FLG390 accelerated osteoblast differentiation to a comparable extent with CDCA, enhancing alkaline phosphatase (ALP) activity and the expression of osteoblast differentiated-related genes such as ALP, collagen type 1 α1 chain (COL1A1), and runt-related transcription factor 2 (RUNX2). FXR activation elevated the expression of cyclooxygenase (COX)-2 and the production of prostaglandin (PG) E₂ in the early phase of osteoblast differentiation. A selective COX-2 inhibitor and an antagonist of EP4 receptors, one of PGE₂ receptors, partially suppressed FXR-activated osteoblast differentiation. Moreover, treatment with either inhibitor during the first 6 h after initiating osteoblast differentiation repressed FXR-activated osteoblast differentiation to the same extent as did the treatment for 6 d. Therefore, a novel FXR agonist, FLG390, exhibited potency comparable to CDCA. FXR activation promoted the early phase of osteoblast differentiation via the COX-2-PGE₂-EP4 axis, representing a potential target for control of bone metabolism. Full article

Osteoporosis, a prevalent metabolic bone disorder, is characterized by reduced bone density and increased fracture risk. The pathogenesis of osteoporosis is closely associated with an imbalance in bone remodeling, in which the resorption function of osteoclasts exceeds the formation function of osteoblasts. Hypoxia has been implicated in the promotion of osteoclast differentiation and the subsequent development of osteoporosis. The ubiquitin–proteasome system (UPS) and its regulatory enzymes, deubiquitinating enzymes (DUBs), play a significant role in bone homeostasis. In this study, we investigated the contribution and mechanism of Ubiquitin-specific protease 18 (USP18), a DUB, in osteoclast differentiation under hypoxic conditions. BMDMs and RAW264.7 cells were treated with RANKL to induce osteoclastogenesis and were subjected to overexpression or knockdown of USP18 under normoxic or hypoxia conditions. Osteoclast formation was assessed using TRAP staining, and the expression of osteoclast marker genes was determined using qRT-PCR. The activation of the NF-κB signaling pathway was evaluated using immunoblotting. We found that hypoxia significantly enhanced the differentiation of BMDMs and RAW264.7 cells into osteoclasts, accompanied by a notable downregulation of USP18 expression. The overexpression of USP18 inhibited RANKL-induced osteoclast differentiation, while the knockdown of USP18 promoted that process, unveiling the inhibitory effect of USP18 in osteoclastogenesis. Furthermore, the overexpression of USP18 rescued the hypoxia-induced increase in osteoclast differentiation. Mechanistic insights revealed that USP18 inhibits osteoclastogenesis by suppressing the NF-κB signaling pathway, with a potential target on TAK1 or its upstream molecules. This study indicates that hypoxia promotes osteoclast differentiation through the downregulation of USP18, which, in turn, relieves the suppression of the activation of the NF-κB signaling pathway. The USP18 emerges as a potential therapeutic target for osteoporosis treatment, highlighting the importance of the hypoxia–DUB axis in the pathogenesis of the disease. Full article

The present study investigates the influence of nitrosamines and etoposide on mesenchymal stromal cells (MSCs) in a differentiation state- and biological age-dependent manner. The genotoxic effects of the agents on both neonatal and adult stem cell populations after treatment, before, or during the course of differentiation, and the sensitivity of the different MSC types to different concentrations of MNU or etoposide were assessed. Hereby, the multipotent differentiation capacity of MSCs into osteoblasts, adipocytes, and chondrocytes was analyzed. Our findings reveal that while all cell types exhibit DNA damage upon exposure, neonatal CB-USSCs demonstrate enhanced resistance to genotoxic damage compared with their adult counterparts. Moreover, the osteogenic differentiation of MSCs was more susceptible to genotoxic damage, whereas the adipogenic and chondrogenic differentiation potentials did not show any significant changes upon treatment with genotoxin. Furthermore, we emphasize the cell-specific variability in responses to genotoxic damage and the differences in sensitivity and reaction across different cell types, thus advocating the consideration of these variabilities during drug testing and developmental biological research. Full article

In recent years, there has been a growing number of adult orthodontic patients with periodontal disease. The progression of periodontal disease is well-linked to oxidative stress (OS). Nevertheless, the impact of OS on orthodontic tooth movement (OTM) is not fully clarified. Therefore, we applied an OS in vitro-model utilizing H₂O₂ to study its effect on tension-induced mechanotransduction in human osteoblasts (hOBs). Experimental parameters were established based on cell viability and proliferation. Apoptosis detection was based on caspase-3/7 activity. Gene expression related to bone-remodeling (RUNX2, P2RX7, TNFRSF11B/OPG), inflammation (CXCL8/IL8, IL6, PTRGS2/COX2), autophagy (MAP1LC3A/LC3, BECN1), and apoptosis (CASP3, CASP8) was analyzed by RT-qPCR. IL6 and PGE2 secretion were determined by ELISA. Tension increased the expression of PTRGS2/COX2 in all groups, especially after stimulation with higher H₂O₂ concentration. This corresponds also to the measured PGE2 concentrations. CXCL8/IL8 was upregulated in all groups. Cells subjected to tension alone showed a general upregulation of osteogenic differentiation-related genes; however, pre-stimulation with OS did not induce significant changes especially towards downregulation. MAP1LC3A/LC3, BECN1 and CASP8 were generally upregulated in cells without OS pre-stimulation. Our results suggest that OS might have considerable impacts on cellular behavior during OTM. Full article

Objectives: Dental bone formation involves various cellular and molecular mechanisms, and phytoestrogens such as formononetin (FORM) are promising because of their estrogenic, anti-inflammatory, and antioxidant effects. This study investigated the effect of FORM on osteoblast proliferation, differentiation, and mineralization in combination with spongiosa granulates (BO) in vitro. Materials and Methods: Human fetal osteoblast cells (hFOB1.19) were treated with increasing concentrations of FORM (1, 10, and 100 µg/mL), BO, or their combination. Cell proliferation was assessed using a MTT assay. Alkaline phosphatase (ALP) activity, intracellular Ca²⁺, and Pi levels were measured using ELISA. Vascular endothelial growth factor (VEGF) and osteocalcin expression levels were analyzed by western blotting. Results: Cell proliferation increased with FORM, with or without BO, after 6 days (p < 0.001). FORM and BO had a synergistic effect on ALP activity (p < 0.001). Intracellular Ca²⁺ and Pi levels were highest in the BO-FORM group, suggesting superior mineralization (p < 0.05). VEGF and osteocalcin expression was significantly upregulated with FORM, alone and with BO (p < 0.05), indicating improved angiogenesis and bone maturation over 9 days. Conclusions: FORM enhances osteoblast proliferation, differentiation, and mineralization potential, particularly in BO spongiosa granulates. These data support the in vitro potential of formononetin-phytoestrogen in promoting osteoblast differentiation and mineralization potential with BO. These findings suggest that FORM, combined with BO, could improve bone augmentation in clinical applications such as maxillofacial surgery. FORM shows valuable potential for clinical applications, such as maxillofacial surgery, by promoting faster and more effective healing. Full article

Osteoporosis, a common metabolic bone disorder, leads to increased fracture risk and significant morbidity, particularly in postmenopausal women and the elderly. Traditional treatments often fail to fully restore bone health and may cause side effects, prompting the exploration of regenerative therapies. Adipose-derived stem cells (ADSCs) offer potential for osteoporosis treatment, but their natural inclination toward adipogenic rather than osteogenic differentiation poses a challenge. This study investigates a novel approach combining differentiation inducers (DIs), three-dimensional (3D) hydrogel scaffolds, and photobiomodulation (PBM) to promote osteogenic differentiation of immortalised ADSCs. A dextran-based 3D hydrogel matrix, supplemented with a DI cocktail of dexamethasone, β-glycerophosphate disodium, and ascorbic acid, was used to foster osteogenesis. PBM was applied using near-infrared (825 nm), green (525 nm), and combined wavelengths at fluences of 3 J/cm², 5 J/cm², and 7 J/cm² to enhance osteogenic potential. Flow cytometry identified osteoblast-specific markers, while inverted light microscopy evaluated cellular morphology. Reactive oxygen species assays measured oxidative stress, and quantitative polymerase chain reaction (qPCR) revealed upregulated gene expression linked to osteogenesis. The findings demonstrate that integrating DIs, 3D hydrogels, and PBM effectively drives osteogenic differentiation in immortalised ADSCs. The PBM enhanced osteogenic marker expression, induced morphological changes, and upregulated gene activity, presenting a promising framework for bone regeneration. Future research should assess the stability and functionality of these differentiated cells and explore their applicability in preclinical models of bone injury or degeneration. This integrative approach demonstrated specific efficacy in promoting the osteogenic differentiation of ADSCs, highlighting its potential application in developing targeted treatments for osteoporosis. Full article

Background: Lutein, a carotenoid, exhibits various biological activities such as maintaining the health of the eye, skin, heart, and bone. Recently, we found that lutein has dual roles in suppressing bone resorption and promoting bone formation. In this study, we examined the effects of lutein in a disuse-induced osteoporosis model using hindlimb-unloaded (HLU) mice. Methods: Osteoclast differentiation was assessed by coculturing mouse primary osteoblasts and bone marrow cells or culturing a mouse osteoclast precursor cell line. The bone-resorbing activity was determined by mouse calvarial organ cultures. An in situ docking simulation was conducted to reveal the interaction of lutein and IκB kinase (IKK) β protein. HLU mice were fed a 1% lutein-containing diet for two weeks, and the femoral bone mass was measured by μCT. Results: Osteoclast differentiation is significantly inhibited by lutein, astaxanthin, and β-cryptoxanthin. In contrast, only lutein promoted osteoblastic calcified bone nodule formation. To elucidate the molecular role of lutein, we functionally analyzed the NF-κB complex, a molecule involved in bone metabolism, especially in osteoclasts. Docking simulations showed that lutein binds to IKK, thus inhibiting the activation of NF-κB. In a cell culture analysis, the phosphorylation of p65, the active form of NF-κB in osteoblasts, was suppressed by lutein treatment. In vivo, a μCT analysis of the bone microarchitecture showed that lutein improves several bone parameters while maintaining bone mass. Conclusions: Lutein is effective in maintaining bone mass by controlling both bone resorption and formation, which is applied to prevent disuse-induced osteoporosis. Full article

Objective: Ensuring adequate bone health is crucial for preventing conditions such as osteoporosis and fractures. Zingerone, a phytonutrient isolated from cooked ginger, has gained attention for its potential benefits in bone health. This study evaluated the osteoprotective potential of zingerone and its effects on differentiation and signalling pathways in vitro using SAOS-2 osteosarcoma and RAW264.7 macrophage cell lines, aiming to elucidate its mechanism of action in bone remodelling. Methods: SAOS-2 osteosarcoma and RAW264.7 macrophage cells were treated with zingerone at concentrations of 200 µM. Osteoblast differentiation was assessed by alkaline phosphatase (ALP) activity, bone mineralisation via Alizarin Red S stain, and gene expression markers (ALP, runt-related transcription factor 2 (Runx2), and osteocalcin) via quantitative polymerase chain reaction (q-PCR). Osteoclast differentiation was evaluated by tartrate-resistant acid phosphatase (TRAP) staining, TRAP activity, and mitogen-activated protein kinase (MAPK) pathways. Results: Treatment with zingerone was non-toxic at 200 µM. Zingerone (200 µM) significantly stimulated the gene expression of ALP and Runx2 in SAOS-2 cells (p < 0.05) without statistically significantly enhancing SAOS-2 mineralisation via calcium deposits. Moreover, zingerone significantly inhibited osteoclast differentiation in RAW264.7 cells as evidenced by reduced TRAP staining and activity (p < 0.05). Conclusions: Zingerone shows promise in reducing osteoclast activity and supporting early osteoblast differentiation, suggesting its potential as a dietary supplement for bone health. Further in vivo and clinical studies are needed to confirm its role in managing osteoporosis. Full article

Postmenopausal osteoporosis (PMOP) is a bone disease characterized by bone thinning and an increased risk of fractures due to estrogen deficiency. Current PMOP therapies often result in adverse side effects. The traditional medicinal plant Curculigo capitulata is commonly used to strengthen bones and support kidney function, but its role in treating PMOP is not well understood. This study aims to investigate the therapeutic effects of the total extract of Curculigo capitulata (Eocc) on PMOP and to explore the underlying mechanisms. The major components of the extract were identified using HPLC. Transcriptomics was employed to predict potential targets. An osteogenic differentiation model of MC3T3-E1 cells was used in vitro. The osteogenic potential of the Eocc was assessed through CCK-8 cell viability assays, alkaline phosphatase (ALP) staining, Alizarin Red staining, Western blotting, and qPCR. MCF-7 and HEK-293 cells were utilized to evaluate the estrogen-like activity of Eocc. Apoptosis rates were detected by flow cytometry. In vivo, a bilateral ovariectomized mouse model of PMOP was used to further validate the in vitro findings through histopathological analysis and WB results. The results demonstrated that the Eocc promoted the proliferation of MC3T3-E1 cells, increased ALP activity, and stimulated the formation of osteogenic mineralized nodules. It also upregulated the expression of osteogenic markers (Runx2, OCN, OPN, and BSP) at both the protein and mRNA levels. The Eocc induced the activation of ERα both in vitro and in vivo, initiating the Src/PI3K/AKT signaling pathway, leading to the phosphorylation of GSK3β and subsequent osteogenesis. The activation of this pathway also stimulated the phosphorylation of mTOR and p70S6K while downregulating cleaved caspase-3 and caspase-9. Additionally, the Eocc reduced apoptosis during osteogenic differentiation and promoted cell proliferation. These findings suggest that the Eocc facilitates osteoblast proliferation and differentiation, improving bone integrity in PMOP mice, and may represent a promising therapeutic candidate for managing PMOP. Full article

Osteoporosis is the most prevalent metabolic bone disease, especially when aggravated by aging and long-term bed rest of various causes and also when coupled with astronauts’ longer missions in space. Research on the use of static magnetic fields (SMFs) has been progressing as a noninvasive method for osteoporosis due to the complexity of the disease, the inconsistency of the effects of SMFs, and the ambiguity of the mechanism. This paper studied the effects of mice subjected to hindlimb unloading (UL, HLU) and reloading by the 0.2 T–0.4 T static magnetic field (MMF). Primary bone marrow mesenchymal stem cells (BMSCs) were extracted to explore the mechanism. Eight-week-old male C57BL/6 mice were used as an osteoporosis model by HLU for four weeks. The HLU recovery period (reloading, RL) was carried out on all FVEs and recovered in the geomagnetic field (45–64 μT, GMF) and MMF, respectively, for 12 h/d for another 4 weeks. The tibia and femur of mice were taken; also, the primary BMSCs were extracted. MMF promoted the recovery of mechanical properties after HLU, increased the number of osteoblasts, and decreased the number of adipocytes in the bone marrow. MMF decreased the total iron content and promoted the total calcium content in the tibia. In vitro experiments showed that MMF promoted the osteogenic differentiation of BMSCs and inhibited adipogenic differentiation, which is related to iron metabolism, the Wnt/β-catenin pathway, and the PPARγ pathway. MMF accelerated the improvement in bone metabolism and iron metabolism in RL mice to a certain extent, which improved the bone quality of mice. MMF mainly promoted osteogenic differentiation and reduced the adipogenic differentiation of BMSCs, which provides a reliable research direction and transformation basis for the osteoporosis of elderly, bedridden patients and astronauts. Full article