Search Results (140)

Proper joint function has a significant impact on people’s quality of life. Joints are the point of connection between two or more bones and consist of at least three elements: joint surfaces, the joint capsule, and the joint cavity. Joint diseases are a serious social problem. Risk factors for the development of these diseases include overweight and obesity, gender, and intestinal microbiome disorders. Another factor that is considered to influence joint diseases is trace elements. Under normal conditions, elements such as iron (Fe), copper (Cu), cobalt (Co), iodine (I), manganese (Mn), zinc (Zn), silver (Ag), cadmium (Cd), mercury (Hg), lead (Pb), nickel (Ni) selenium (Se), boron (B), and silicon (Si) are part of enzymes involved in reactions that determine the proper functioning of cells, regulate redox metabolism, and determine the maturation of cells that build joint components. However, when the normal concentration of the above-mentioned elements is disturbed and toxic elements are present, dangerous joint diseases can develop. In this article, we focus on the role of trace elements in joint function. We describe the molecular mechanisms that explain their interaction with chondrocytes, osteocytes, osteoblasts, osteoclasts, and synoviocytes, as well as their proliferation, apoptosis, and extracellular matrix synthesis. We also focus on the role of these trace elements in the pathogenesis of joint diseases: rheumatoid arthritis (RA), osteoarthritis (OA), psoriatic arthritis (PsA), ankylosing spondylitis (AS), and systemic lupus erythematosus (SLE). We describe the roles of increased or decreased concentrations of individual elements in the pathogenesis and development of joint diseases and their impact on inflammation and disease progression, referring to molecular mechanisms. We also discuss their potential application in the treatment of joint diseases. Full article

This study examines the cytotoxicity of two silver nanoparticle formulations—AgNPs conjugated with chlorhexidine (AgNPs-CHL) and AgNPs conjugated with polyethylene glycol and metronidazole (AgNPs-PEG-MET)—as examples of the surface functionalization of silver nanoparticles with drugs via sulfur–silver bonds and nitrogen–silver interactions. We previously reported the synthesis of these NPs and their efficiency in periodontitis treatment. Here, we analyze the relationships between the cytotoxic mechanisms of AgNPs and their surface chemistry. UV–Vis spectroscopy, dynamic light scattering (DLS), and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) were used for physicochemical studies of the conjugates in two environments: aqueous solutions and commonly used cell culture media. Cytotoxicity was assessed in human fetal osteoblasts (hFOB 1.19) and human gingival fibroblasts (HGF-1) through BrdU and LDH assays, ROS detection, cell cycle analysis, apoptosis assays, and protein expression studies. AgNPs-CHL showed aggregation and increased hydrodynamic diameters in the culture medium, while AgNPs-PEG-MET remained stable. Both exhibited concentration-dependent cytotoxicity: AgNPs-CHL at 0.4–10 μg/mL and AgNPs-PEG-MET at 0.75–10 μg/mL. AgNPs-CHL, in which silver surface functionalization was realized via nitrogen–silver interactions, induced significant ROS generation, LDH release, and necroptosis, marked by increased RIP1, RIP3, and MLKL proteins. In the case of AgNPs-PEG-MET, where sulfur–silver bonds combined the drug via a PEG linker, they triggered apoptosis, as evidenced by elevated caspase-2 levels and flow cytometry. These findings highlight that the type of surface functionalization of silver nanoparticles significantly influences their physicochemical behavior and biological effects. Understanding these mechanisms is crucial in designing safer, more effective nanoparticle-based therapies for periodontal and other inflammatory conditions. Full article

Research findings reveal that thermal environments precisely regulate the skeletal system through a triple regulation of “structural morphology-cellular dynamics-molecular mechanisms”: At the tissue morphology level, moderate heat exposure can promote increased bone density and longitudinal growth, as well as improved fracture load and yield point, but may negatively affect geometric shape and cortical bone thickness. Continuous high-temperature exposure harms bone structure, manifested as changes in biomechanical characteristics such as decreased toughness and rigidity. At the cellular level, thermal environments directly affect the proliferation/apoptosis balance of osteoblasts and osteoclasts, and by regulating osteocyte network activity and bone marrow mesenchymal stem cell fate decisions, these four cell populations form temperature-dependent metabolic regulatory circuits. At the molecular dimension, heat stress can activate the release of neural factors such as CGRP and NPY, which possess dual regulatory functions promoting both bone formation and resorption; simultaneously achieving coordinated regulation of angiogenesis and fat inhibition through VEGF and TGFβ. The thermal environment–bone regulatory mechanisms revealed in this study have important translational value: they not only provide theoretical basis for biomechanical protection strategies for high-temperature workers and athletes, but also offer innovative entry points for analyzing the pathological mechanisms of heat stroke secondary bone injury and osteoporosis through heat stress-related signaling pathways, while establishing a theoretical foundation for the development of temperature-responsive functionalized biomaterials in bone tissue engineering. Full article

Diabetes-related osteoporosis has been known to be a consequence of oxidative stress caused by excessive reactive oxygen species (ROS) production in the tissues. Despite the increase in the number of individuals with diabetes-related osteoporosis year on year, there is still no effective drug that does not induce adverse side effects. Glabridin, which exerts hypoglycemic effects and possesses antioxidant properties, may have beneficial effects in the treatment of diabetes-related osteoporosis. In this study, we aimed to investigate the preventive effects of glabridin in counteracting oxidative stress-induced bone loss and its underlying mechanisms. A diabetic rat model was established by a single intraperitoneal injection of streptozotocin into male Wistar rats. The diabetic rats were orally gavaged daily with glabridin or glyburide for 8 weeks. The presence of diabetes significantly decreased the rats’ tibia length, bone thickness, epiphyseal plate length, and collagen deposition compared to the control rats; in comparison, treatment with glabridin for 8 weeks significantly reversed these effects. In our in vitro study, the treatment of MC3T3-E1 preosteoblasts with glabridin up to 7.5 µM for 48 h showed no cytotoxic effect. However, pretreatment with glabridin significantly prevented oxidative stress-induced inhibition of cell proliferation. In addition, glabridin significantly diminished ROS production, restored antioxidant enzyme activity, and mitigated cellular apoptosis. These effects occurred by stimulating the phosphorylation of Akt, GSK-3β, and P65 NF-ĸB proteins. The above results show that glabridin alleviated oxidative stress-induced bone loss and osteoblast cell apoptosis by modulating the expression of the Akt/NF-ĸB and Akt/GSK-3β pathways. Full article

Background/Objectives: Glucocorticoid-induced osteonecrosis of the femoral head (GIOFH) is a debilitating condition resulting from impaired bone metabolism and vascular disruption due to prolonged glucocorticoid use. This study aimed to explore the therapeutic potential of salvigenin, a flavonoid with antioxidative and estrogen-like properties, in alleviating GIOFH by modulating estrogen receptor alpha (ESR1) pathways. Methods: A network pharmacology approach was utilized to identify salvigenin’s potential targets and their association with GIOFH. Protein–protein interaction networks, along with Gene Ontology and KEGG pathway analyses, were conducted to clarify salvigenin’s multi-target mechanisms. Molecular docking and dynamics simulations assessed the interaction between salvigenin and ESR1. Experimental validation included in vitro assays on MG63 cells treated with dexamethasone (Dex) to mimic GIOFH, evaluating oxidative stress, apoptosis, osteogenic differentiation, and ESR1 expression. Results: Network analysis identified ESR1, NOS3, and MMP9 as key hub targets of salvigenin. Molecular docking and dynamics simulations confirmed stable binding of salvigenin to ESR1. Salvigenin significantly reduced Dex-induced oxidative stress and apoptosis in osteoblasts while restoring osteogenic differentiation and ESR1 expression. Functional assays showed improved mineralized nodule formation, ALP activity, and mitochondrial integrity in salvigenin-treated cells. Conclusions: Salvigenin exhibits significant therapeutic potential in addressing GIOFH through ESR1-mediated pathways. These results offer a strong foundation for future translational studies and the development of salvigenin-based therapies for glucocorticoid-induced bone disorders. Full article

Background and aim: Prolonged glucocorticoid (GC) treatment increases oxidative stress, triggers apoptosis of osteoblasts, and contributes to osteoporosis. Tocotrienol, as an antioxidant, could protect the osteoblasts and preserve bone quality under glucocorticoid treatment. From this study, we aimed to determine the effects of tocotrienol on MC3T3-E1 murine pre-osteoblastic cells treated with GC. Methods: MC3T3-E1 cells were exposed to dexamethasone (150 µM), with or without palm tocotrienol (PTT; 0.25, 0.5, and 1 µg/mL). Cell viability was measured by the MTS assay. Alizarin Red staining was performed to detect calcium deposits. Cellular alkaline phosphatase activity was measured to evaluate osteogenic activity. The expression of osteoblastic differentiation markers was measured by an enzyme-linked immunoassay. Results: Enhanced matrix mineralization was observed in the cells treated with 0.5 µg/mL PTT, especially on day 18 (p < 0.05). The expression of Wnt3a, β-catenin, collagen 1α1, alkaline phosphatase, osteocalcin, low-density lipoprotein receptor-related protein 6, and runt-related transcription factor-2 were significantly increased in the PTT-treated groups compared to the vehicle control group, especially at 0.5 µg/mL of PTT (p < 0.05) and on day 6 of treatment. Conclusions: PTT maintains the osteogenic activity of the dexamethasone-treated osteoblasts by promoting their differentiation. 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

Alkaptonuria (AKU) is a genetically determined disease associated with disorders of tyrosine metabolism. In AKU, the deposition of homogentisic acid polymers contributes to the pathological ossification of cartilage tissue. The controlled use of biomimetics similar to deposits observed in cartilage during AKU potentially may serve the development of new bone regeneration therapy based on the activation of osteoblasts. The proposed biomimetic is pyomelanin (PyoM), a polymeric biomacromolecule synthesized by Pseudomonas aeruginosa. This work presents comprehensive data on the osteoinductive, pro-regenerative, and antibacterial properties, as well as the cytocompatibility, of water-soluble (PyoM_sol) or water-insoluble (PyoM_insol) PyoM. Both variants of PyoM support osteoinductive processes as well as the maturation of osteoblasts in cell cultures in vitro due to the upregulation of bone-formation markers, osteocalcin (OC), and alkaline phosphatase (ALP). Furthermore, the cytokines involved in these processes were elevated in cell cultures of osteoblasts exposed to PyoM: tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-10. The PyoM variants are cytocompatible in a wide concentration range and limit the doxorubicin-induced apoptosis of osteoblasts. This cytoprotective PyoM activity is correlated with an increased migration of osteoblasts. Moreover, PyoM_sol and PyoM_insol exhibit antibacterial activity against staphylococci isolated from infected bones. The osteoinductive, pro-regenerative, and antiapoptotic effects achieved through PyoM stimulation prompt the development of new biocomposites modified with this bacterial biopolymer for medical use. Full article

Background: Glucocorticoids (GCs) are critical regulatory molecules in the body, commonly utilized in clinical practice for their potent anti-inflammatory and immunosuppressive properties. However, prolonged, high-dose GC therapy is frequently associated with femoral head necrosis, a condition known as glucocorticoid-induced osteonecrosis of the femoral head (GC-ONFH). Emerging evidence suggests that enhanced autophagy may mitigate apoptosis, thereby protecting osteoblasts from GC-induced damage and delaying the progression of ONFH. This study aims to evaluate whether human umbilical cord mesenchymal stem cells (hUCMSCs) can alleviate GC-induced osteoblast injury through autophagy modulation. Methods: In vitro, osteoblasts were exposed to GCs for 48 h, followed by co-culture with hUCMSCs for an additional 12 h before further analysis. The osteoblasts were categorized into four experimental groups: (A) control group, (B) Dex group, (C) Dex + hUCMSC group, and (D) Dex + hUCMSC + 3-MA group. In vivo, rabbits were assigned to one of four groups: Con, MPS, core decompression (CD), and CD + hUCMSC (n = 12 per group), and subsequently subjected to CT imaging and HE staining. Results: In vitro results demonstrate that hUCMSC treatment mitigated GC-induced osteoblast apoptosis and preserved osteogenic activity through autophagy modulation. In vivo, infusion of hUCMSCs enhanced trabecular thickness in the femoral head and improved the femoral head microenvironment. Conclusions: These findings suggest that hUCMSCs protect osteoblasts from GC-induced damage by regulating autophagy, offering new insights into the potential therapeutic use of hUCMSCs for treating ONFH via autophagy enhancement. 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

1,2,3,4,6-penta-O-galloyl-β-D-glucose (PGG) is the main phenolic active ingredient in Paeoniae Radix Alba, which is commonly used for the treatment of osteoporosis (OP). PGG is a potent natural antioxidant, and its effects on OP remain unknown. This study aimed to investigate the effects of PGG on promoting bone formation and explore its estrogen receptor (ER)-related mechanisms. A hydrogen peroxide-induced osteoblast apoptosis model was established in MC3T3-E1 cells. The effects of PGG were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, alkaline phosphatase (ALP) staining, RT-qPCR, and Western blot methods. Furthermore, a prednisolone-induced zebrafish OP model was employed to study the effects in vivo. ER inhibitors and molecular docking methods were used further to investigate the interactions between PGG and ERs. The results showed that PGG significantly enhanced cell viability and decreased cell apoptosis by restoring mitochondrial function, attenuating reactive oxygen species levels, decreasing the mitochondrial membrane potential, and enhancing ATP production. PGG enhanced ALP expression and activity and elevated osteogenic differentiation. PGG also promoted bone formation in the zebrafish model, and these effects were reversed by ICI182780. These results provide evidence that the effects of PGG in alleviating apoptosis and promoting bone formation may depend on ERs. As such, PGG is considered a valuable candidate for treating OP. Full article

Osteoporosis is a common skeletal disease, primarily associated with aging, that results from decreased bone density and bone volume. This reduction significantly increases the risk of fractures in osteoporosis patients compared to individuals with normal bone density. Additionally, the bone regeneration process in these patients is slow, making complete healing difficult. Along with the decline in bone volume and density, osteoporosis is characterized by an increase in marrow adipose tissue (MAT), which is fat within the bone. In this altered bone microenvironment, osteoblasts are influenced by various factors secreted by adipocytes. Notably, saturated fatty acids promote osteoclast activity, inhibit osteoblast differentiation, and induce apoptosis, further reducing osteoblast formation. In contrast, monounsaturated fatty acids inhibit osteoclast formation and mitigate the apoptosis caused by saturated fatty acids. Leveraging these properties, we aimed to investigate the effects of overexpressing stearoyl-CoA desaturase 1 (SCD1), an enzyme that converts saturated fatty acids into monounsaturated fatty acids, on osteogenic differentiation and bone regeneration in both in vivo and in vitro models. Through this novel approach, we seek to develop a stem cell-based therapeutic strategy that harnesses SCD1 to improve bone regeneration in the adipocyte-rich osteoporotic environment. Full article

Bone is a dynamic organ with an active metabolism and high sensitivity to mitochondrial dysfunction. The mitochondrial permeability transition pore (mPTP) is a low-selectivity channel situated in the inner mitochondrial membrane (IMM), permitting the exchange of molecules of up to 1.5 kDa in and out of the IMM. Recent studies have highlighted the critical role of the mPTP in bone tissue, but there is currently a lack of reviews concerning this topic. This review discusses the structure and function of the mPTP and its impact on bone-related cells and bone-related pathological states. The mPTP activity is reduced during the osteogenic differentiation of mesenchymal stem cells (MSCs), while its desensitisation may underlie the mechanism of enhanced resistance to apoptosis in neoplastic osteoblastic cells. mPTP over-opening triggers mitochondrial swelling, regulated cell death, and inflammatory response. In particular, mPTP over-opening is involved in dexamethasone-induced osteoblast dysfunction and bisphosphonate-induced osteoclast apoptosis. In vivo, the mPTP plays a significant role in maintaining bone homeostasis, with many bone disorders linked to its excessive opening. Genetic deletion or pharmacological inhibition of the over-opening of mPTP has shown potential in enhancing bone injury recovery and alleviating bone diseases. Here, we review the findings on the relationship of the mPTP and bone at both the cellular and disease levels, highlighting novel avenues for pharmacological approaches targeting mitochondrial function to promote bone healing and manage bone-related disorders. Full article

The suppressive effect of bisphosphonates (BPs) on bone metabolism is considered to be a major cause of medication-related osteonecrosis of the jaw (MRONJ). Enamel matrix derivative (EMD) stimulates and activates growth factors, leading to the regeneration of periodontal tissues. In this study, we aimed to explore the potential of EMD in reversing the detrimental effects of BPs on human fetal osteoblasts (hFOBs) and osteosarcoma-derived immature osteoblasts (MG63s) by assessing cell viability, apoptosis, migration, gene expression, and protein synthesis. While the suppressive effect of zoledronate (Zol) on cell viability and migration was observed, the addition of EMD significantly mitigated this effect and enhanced cell viability and migration. Furthermore, an increased apoptosis rate induced by Zol was decreased with the addition of EMD. The decreased gene expression of alkaline phosphatase (ALP), osteocalcin (OC), and the receptor activator of nuclear factors kappa-B ligand (RANKL) caused by BP treatment was reversed by the co-addition of EMD to hFOB cells. This trend was also observed for ALP and bone sialoprotein (BSP) levels in MG63 cells. Furthermore, suppressed protein levels of OC, macrophage colony-stimulating factor (M-CSF), BSP, and type 1 collagen (COL1) were recovered following the addition of EMD. This finding suggests that EMD could mitigate the effects of BPs, resulting in the recovery of cell survival, migration, and gene and protein expression. However, the behavior of the osteoblasts was not fully restored, and further studies are necessary to confirm their effects at the cellular level and to assess their clinical usefulness in vivo for the prevention and treatment of MRONJ. Full article

In adverse environments, fine dust is linked to a variety of health disorders, including cancers, cardiovascular, neurological, renal, reproductive, motor, systemic, and respiratory diseases. Although PM10 is associated with oral inflammation and cancer, there is limited research on biomaterials that prevent damage caused by fine dust. In this study, we evaluated the effects of biomaterials using microRNA profiling, flow cytometry, conventional PCR, immunocytochemistry, Alizarin O staining, and ELISA. Compared to SBE (Scutellaria baicalensis extract), the preventive effectiveness of SBEIEs (SBE-induced exosomes) against fine dust was approximately two times higher. Furthermore, SBEIEs promoted cellular differentiation of periodontal ligament stem cells (PDLSCs) into osteoblasts, periodontal ligament cells (PDLCs), and pulp progenitor cells (PPCs), enhancing immune modulation for oral health against fine dust. In terms of immune modulation, SBEIEs activated the secretion of cytokines such as IL-10, LL-37, and TGF-β in T cells, B cells, and macrophages, while attenuating the secretion of MCP-1 in macrophages. MicroRNA profiling revealed that significantly modulated miRNAs in SBEIEs influenced four biochemical categories: apoptosis, cellular differentiation, immune activation, and anti-inflammation. These findings suggest that SBEIEs are an optimal biomaterial for developing oral health care products. Additionally, this study proposes functional microRNA candidates for the development of pharmaceutical liposomes. Full article