Regulation Of Bone Metabolism Research Articles

Osteoprotegerin (OPG): A potential biomarker for adverse cardiovascular events in stable coronary artery disease.

Osteoprotegerin (OPG) is a secretory glycoprotein known for its involvement in bone metabolism and immune regulation. Research has extended OPG's significance in cardiovascular diseases (CVDs). Elevated OPG levels have been associated with increased cardiovascular risks, prompting interest in its role as a potential biomarker. This study summarizes several studies that investigated the relationship between OPG levels and the incidence of CVD. The studies indicate that higher plasma levels of OPG are associated with an increased incidence of all-cause death, cardiovascular death, and heart failure, even after adjusting for clinical confounders. Moreover, the findings suggest that OPG has the potential to serve as a predictive biomarker for adverse cardiovascular events in the patient population studied. The findings suggest that OPG could aid in risk stratification, allowing clinicians to identify high-risk patients who might benefit from intensified preventive measures or tailored therapeutic interventions. Therefore, early identification of individuals at risk for adverse cardiovascular events could lead to improved patient outcomes and reduced disease burden. OPG's role in bone health and immune regulation has expanded to potential use as a biomarker for adverse cardiovascular events in stable coronary artery disease (CAD) patients. Despite limitations, its association with cardiovascular risks highlights its importance in risk assessment and personalized interventions.

Potential Predictive of Thoracic CT Value and Bone Mineral Density T-Value in COPD Complicated with Osteoporosis.

COPD, combined with Osteoporosis, has a high incidence and potential for great harm. Choosing an optimal diagnostic method to achieve bone mineral density (BMD) screening is crucial for COPD patients. Studies on COPD patients with BMD reduction are lacking. To identify the risk factors of BMD reduction and osteoporosis in COPD patients. We included a total of 81 patients with AECOPD, who were admitted to the hospital from July 1, 2019, to January 31, 2020. Patients were grouped into BMD normal group, BMD reduced group and OP group. The areas under ROC curve were used to explore the value of CT values in the diagnosis of bone abnormality, and clinical indicators were collected. The CT value of the vertebral cancellous bone is highly correlated with the T value of BMD (R > 5.5, P < 0.0001). Using multivariate Logistic regression analysis, we showed that COPD duration, BMI, 25-hydroxyvitamin D3, and long-term inhaled glucocorticoid were independent factors affecting different BMD levels in COPD patients. No significant difference in bone formation indexes between groups. β-crossL was negatively correlated with serum IL-6 (r=-0.254, P=0.022), and ALP was positively correlated with serum TNF-α (r=0.284, P=0.023). Thoracolumbar vertebral cancellous bone CT has potential value in the diagnosis of bone abnormality. COPD duration, BMI, 25-hydroxyvitamin D3, and long-term inhaled glucocorticoid may contribute to the BMD reduction in COPD patients, and serum IL-6 and TNF-α regulate bone metabolism in COPD patients.

Comparative Analysis of Myokines and Bone Metabolism Markers in Prepubertal Vegetarian and Omnivorous Children.

The role of bone and muscle as endocrine organs may be important contributing factors for children's growth and development. Myokines, secreted by muscle cells, play a role in regulating bone metabolism, either directly or indirectly. Conversely, markers of bone metabolism, reflecting the balance between bone formation and bone resorption, can also influence myokine secretion. This study investigated a panel of serum myokines and their relationships with bone metabolism markers in children following vegetarian and omnivorous diets. A cohort of sixty-eight healthy prepubertal children, comprising 44 vegetarians and 24 omnivores, participated in this study. Anthropometric measurements, dietary assessments, and biochemical analyses were conducted. To evaluate the serum concentrations of bone markers and myokines, an enzyme-linked immunosorbent assay (ELISA) was used. The studied children did not differ regarding their serum myokine levels, except for a higher concentration of decorin in the vegetarian group (p = 0.020). The vegetarians demonstrated distinct pattern of bone metabolism markers compared to the omnivores, with lower levels of N-terminal propeptide of type I procollagen (P1NP) (p = 0.001) and elevated levels of C-terminal telopeptide of type I collagen (CTX-I) (p = 0.018). Consequently, the P1NP/CTX-I ratio was significantly decreased in the vegetarians. The children following a vegetarian diet showed impaired bone metabolism with reduced bone formation and increased bone resorption. Higher levels of decorin, a myokine involved in collagen fibrillogenesis and essential for tissue structure and function, may suggest a potential compensatory mechanism contributing to maintaining bone homeostasis in vegetarians. The observed significant positive correlations between myostatin and bone metabolism markers, including P1NP and soluble receptor activator of nuclear factor kappa-B ligand (sRANKL), suggest an interplay between muscle and bone metabolism, potentially through the RANK/RANKL/OPG signaling pathway.

Osteoprotegerin mediates adipogenesis in obesity

IntroductionAdipogenesis, the process of white adipose tissue expansion, plays a critical role in the development of obesity. Osteoprotegerin (OPG), known for its role in bone metabolism regulation, emerges as a potential regulator in mediating adipogenesis during obesity onset. ObjectivesThis study aims to elucidate the involvement of OPG in adipogenesis during the early phases of diet-induced obesity and explore its therapeutic potential in obesity management. MethodsUsing a diet-induced obesity model, we investigated OPG expression patterns in adipocytes and explored the mechanisms underlying its involvement in adipogenesis. We also assessed the effects of targeted silencing of OPG and recombinant OPG administration on obesity progression and insulin resistance. Additionally, the impact of electroacupuncture treatment on OPG levels and obesity management was evaluated in both animal models and human participants. ResultsOPG expression was prominently activated in adipocytes of white adipose tissues during the early phase of diet-induced obesity. Hyperlipidemia induced Cbfa1-dependent OPG transcription, initiating and promoting adipogenesis, leading to cell-size expansion and lipid storage. Intracellular OPG physically bound to RAR and released the PPARɤ/RXR complex, activating adipogenesis-associated gene expression. Targeted silencing of OPG suppressed obesity development, while recombinant OPG administration promoted disease progression and insulin resistance in obese mice. Electroacupuncture treatment suppressed obesity development in an OPG-dependent manner and improved obesity parameters in obese human participants. ConclusionOPG emerges as a key regulator in mediating adipogenesis during obesity development. Targeting OPG holds promise for the prevention and treatment of obesity, as evidenced by the efficacy of electroacupuncture treatment in modulating OPG levels and managing obesity-related outcomes.

Epimedii Folium decoction ameliorates osteoporosis in mice through NLRP3/caspase-1/IL-1β signalling pathway and gut-bone axis

Aim of the studyThis study aimed to determine the effect of Epimedium brevicornu Maxim. (EF) on osteoporosis (OP) and its underlying molecular mechanisms, and to explore the existence of the “Gut-Bone Axis”. Material and methodsThe impact of EF decoction (EFD) on OP was evaluated using istopathological examination and biochemical assays. Targeted metabolomics was employed to identify key molecules and explore their molecular mechanisms. Alterations in the gut microbiota (GM) were evaluated by 16S rRNA gene sequencing. The role of the GM was clarified using an antibiotic cocktail and faecal microbiota transplantation. ResultsEFD significantly increased the weight (14.06%), femur length (4.34%), abdominal fat weight (61.14%), uterine weight (69.86%), and insulin-like growth factor 1 (IGF-1) levels (59.48%), while reducing serum type I collagen cross-linked carboxy-terminal peptide (CTX-I) levels (15.02%) in osteoporotic mice. The mechanism of action may involve the regulation of the NLRP3/cleaved caspase-1/IL-1β signalling pathway in improving intestinal tight junction proteins and bone metabolism. Additionally, EFD modulated the abundance of related GM communities, such as Lactobacillus, Coriobacteriaceae, bacteria of family S24-7, Clostridiales, and Prevotella, and increased propionate and butyrate levels. Antibiotic-induced dysbiosis of gut bacteria disrupted OP regulation of bone metabolism, which was restored by the recovery of GM. ConclusionsOur study is the first to demonstrate that EFD works in an OP mouse model by utilising GM and butyric acid. Thus, EF shows promise as a potential remedy for OP in the future.

Markers of Bone Mineral Metabolism in Thyroid Disorders

Abstract Background and Aim: Thyroid hormones are essential for normal skeletal development and bone metabolism. Despite various studies, the effect of thyroid hormone on bone metabolism has not been clearly understood. We studied the bone formation markers (procollagen type 1 N-propeptide [P1NP] and osteocalcin [OC]) and bone resorption markers (C-terminal cross-linking telopeptide of type 1 collagen [CTX] and tartrate-resistant acid phosphatase [TRAP]) in patients with thyroid disorders and the effect of treatment on them. Furthermore, a study correlating these markers with thyroid-stimulating hormone (TSH) levels was done. Materials and Methods: This cross-sectional study recruited 60 cases (40 – hypothyroid and 20 – hyperthyroid) and 20 controls based on inclusion and exclusion criteria. To evaluate the effect of treatment, cases were further subdivided based on the duration of treatment received into 0-month (newly diagnosed), 1–6-month, and &gt;6-month treatment subgroups. Both the cases and control underwent a thorough history, clinical examination, and detailed investigation based on a predesigned proforma. Results: In hyperthyroidism with 0-month treatment subgroup, both formation (OC, P1NP) and resorption (CTX) markers were significantly increased compared to control (P &lt; 0.05), which became insignificant on treatment (1–6 months) with antithyroid medication despite low TSH value. Contrarily, in hypothyroidism, a statistically significant (P &lt; 0.05) lower mean value of markers (OC, P1NP, and CTX) was observed only in the subgroup with levothyroxine supplementation. In hyperthyroidism, both the formation (OC and P1NP) and resorption markers (CTX and TRAP) showed a strong negative (P &lt; 0.001) correlation with TSH, the strength of correlation decreased, and became insignificant on treatment. In hypothyroidism, only P1NP and CTX showed an overall significant positive (P &lt; 0.05) correlation with TSH. Conclusion: Hyperthyroidism has high bone turnover markers, which showed early reversibility of markers on treatment with antithyroid medication despite low TSH, whereas in hypothyroidism, significantly lower mean value of markers is seen only in the subgroup with levothyroxine supplementation, probably owing to the suppressive effect of TSH. P1NP and CTX showed high sensitivity in both hypothyroidism and hyperthyroidism. The pattern of correlation between TSH and bone metabolism markers in hyperthyroidism suggests a direct negative effect of TSH on bone turnover, whereas in hypothyroidism, it either suggests TSH showing a positive correlation at a very high level which becomes negative as the TSH value decreases or TSH is not a dominant hormone regulating bone metabolism in hypothyroidism.

The role of O-GlcNAcylation in bone metabolic diseases.

O-GlcNAcylation, as a post-translational modification, can modulate cellular activities such as kinase activity, transcription-translation, protein degradation, and insulin signaling by affecting the function of the protein substrate, including cellular localization of proteins, protein stability, and protein/protein interactions. Accumulating evidence suggests that dysregulation of O-GlcNAcylation is associated with disease progression such as cancer, neurodegeneration, and diabetes. Recent studies suggest that O-GlcNAcylation is also involved in the regulation of osteoblast, osteoclast and chondrocyte differentiation, which is closely related to the initiation and development of bone metabolic diseases such as osteoporosis, arthritis and osteosarcoma. However, the potential mechanisms by which O-GlcNAcylation regulates bone metabolism are not fully understood. In this paper, the literature related to the regulation of bone metabolism by O-GlcNAcylation was summarized to provide new potential therapeutic strategies for the treatment of orthopedic diseases such as arthritis and osteoporosis.

Using broadly targeted plant metabolomics technology combined with network pharmacology to explore the mechanism of action of the Yishen Gushu formula in the treatment of postmenopausal osteoporosis in vivo

Ethnopharmacological relevanceYishen Gushu Formula (YSGSF) is composed of Epimedium, prepared Rehmannia, Drynaria, Eucommia, Dodder, ginseng, Astragalus, Ligusticum wallichii, Aucklandia and Panax notoginseng. It can improve bone mineral density by regulating bone metabolism. However, the mechanism of YSGSF in the treatment of Postmenopausal osteoporosis (PMOP) remains unclear. Aim of the studyThe compounds, targets, and molecular mechanisms of YSGSF in the treatment of PMOP were investigated using broad-spectrum target metabolomics from plants, combined with network pharmacology and animal studies, leading to a discussion on a novel approach to understanding YSGSF's action in PMOP treatment. Materials and methodsUsing ultra-performance liquid chromatography coupled with triple quadrupole-linear ion trap tandem mass spectrometry (UPLC-QTRAP-MS/MS) within a comprehensive targeted metabolomics framework, the active constituents of YSGSF were identified. This, alongside network pharmacology and molecular docking, facilitated the identification of critical signaling pathways and targets pertinent to YSGSF's therapeutic effect on PMOP. Subsequently, an animal model for PMOP was developed. Following intervention grouping, rats' weight changes were recorded; serum bone metabolic factors were assessed via ELISA; bone microstructure was examined using HE staining and Micro-CT; and key signaling pathway proteins and genes were analyzed through immunohistochemistry to validate YSGSF's potential mechanism in PMOP treatment. ResultsA total of 84 main active components of YSGSF were identified. The key signaling pathways affected by YSGSF in the treatment of PMOP were the TNF and IL-7 signaling pathways, closely related to TNF-α, IL-1β, c-jun and other protein targets. The results of animal experiments showed that YSGSF could downregulate the expression of TNF-a, IL-1β and c-Jun proinflammatory factors by regulating the TNF and IL-7 signaling pathways and regulate the inflammatory response, osteocyte differentiation and apoptosis to control the development of PMOP. ConclusionYSGSF activates the TNF-α and IL-7 signaling pathways in PMOP rats, reducing TNF-α and IL-1β levels, the c-Jun inflammatory response, and osteocyte differentiation and apoptosis, thus playing a significant role in treating PMOP.

Role of joint adipose tissues in osteoarthritis

Osteoarthritis (OA) is the most common musculoskeletal disease, without any curative treatment. Obesity being the main modifiable risk factor for OA, much attention focused on the role of adipose tissues (AT). In addition to the involvement of visceral and subcutaneous AT via systemic ways, many arguments also highlight the involvement of local AT, present in joint tissues. Local AT include intra-articular AT (IAAT), which border the synovium, and bone marrow AT (BMAT) localized within marrow cavities in the bones. This review describes the known features and involvement of IAAT and BMAT in joint homeostasis and OA. Recent findings evidence that alteration in magnetic resonance imaging signal intensity of infrapatellar fat pad can be predictive of the development and progression of knee OA. IAAT and synovium are partners of the same functional unit; IAAT playing an early and pivotal role in synovial inflammation and fibrosis and OA pain. BMAT, whose functions have only recently begun to be studied, is in close functional interaction with its microenvironment. The volume and molecular profile of BMAT change according to the pathophysiological context, enabling fine regulation of haematopoiesis and bone metabolism. Although its role in OA has not yet been studied, the localization of BMAT, its functions and the importance of the bone remodelling processes that occur in OA argue in favour of a role for BMAT in OA.

Weighted Gene Co-expression Network Analysis of the Inflammatory Wnt Signaling Reveals Biomarkers Related to Bone Formation.

Background and aim Osteocytes regulate bone metabolism and balance through various mechanisms, including the Wnt (Wingless-related integration site signal transduction) signaling pathway. Weighted gene co-expression network analysis (WGCNA) is a computational method to identify functionally related genes based on expression patterns, especially in the Wnt-beta-catenin and osteo-regenerative pathways. This study aims to analyze gene modules of the Wnt signaling pathway from WGCNA analysis. Methods The study used a microarray dataset from the GEO (GSE228306) to analyze differential gene expression in human primary monocytes. The study standardized datasets usingRobust Multi-Array Average (RMA)expression measure and Integrated Differential Expression and Pathway (IDEP) analysistool, building a co-expression network for group-specific component (GC) genes. Results The study uses WGCNA to identify co-expression modules with dysregulated mRNAs, revealing enrichment in Wnt-associated pathways and top hub-enriched genes like colony-stimulating factor 3 (CSF3), interleukin-6 (IL-6), IL-23 subunit alpha (IL23A), suppressor of cytokine signaling 1 (SOCS1), and C-C motif chemokine ligand 19 (CCL19). Conclusion WGCNA analysis of the Wnt signaling pathway will involve functional annotation, network visualization, validation, integration with other omics data, and addressing method limitations for better understanding.

#1948 Transcriptome analysis of the effect of roxadustat on osteoclasts

Abstract Background and Aims In recent years, hypoxia-inducing factor prolyl hydroxylase inhibitors (HIF-PHIs) have been widely used in the treatment of renal anemia, bringing a revolutionary breakthrough in the treatment of anemia in CKD patients. However, HIF-PHIs acts on a variety of cells and regulates the expression of multiple target genes. Some studies have reported that HIF-PHIs plays an important role in regulating bone metabolism and promoting the differentiation and calcification of osteoblasts, but its influence on osteoclasts remains controversial. This study intends to explore the effect of roxadustat, a representative drug of HIF-PHIs, on osteoclasts. Method Bone marrow mononuclear cells (BMMCs) from 6-8 weeks old male C57BL/6 wild mice were extracted and induced to differentiate into osteoclasts using macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL). Meanwhile, lipopolysaccharide (LPS) was used to simulate the inflammatory environment in CKD patients. According to the experimental group, different concentrations of roxadustat (0 μM, 2.5 μM, 5 μM, 10μM) were added simultaneously. When osteoclast induction reached day 6, mRNA was extracted for transcriptome sequencing and bioinformatics analysis. Results As shown in Table 1, different concentrations of roxadustat were given to primary bone marrow monocytes under both conditions, and there were 3 biological replicates for each sample. The reproducibility scatter plot showed that the data in each group had good repeatability (Fig. 1), and the heat map for basic difference analysis of each sample was shown in Fig. 2. The trend analysis results of the two groups were shown in Fig. 3. BMMCs group and LPS stimulated group showed two upward trends, respectively. KEGG enrichment analysis of these two upward trends showed that HIF-1, MAPK, PI3K-Akt, NF-κB and osteoclast differentiation pathways were significantly enriched in both groups. It is suggested that roxadustat can promote osteoclast differentiation and increase inflammatory response with the increase of roxadustat concentration. The enrichment analysis of the two groups showed that there was no significant enrichment pathway. Conclusion We explored the differentiation of osteoclasts under normal conditions and osteoclast differentiation under simulated inflammation in CKD patients respectively. Transcriptomic analysis results showed that HIF-1, MAPK, PI3K-Akt, NF-κB and osteoclast differentiation pathways were significantly enriched with the increase of roxadustat concentration. It is suggested that the use of roxadustat may promote bone destruction and increase the risk of inflammatory response.

Sr-Incorporated Bioactive Glass Remodels the Immunological Microenvironment by Enhancing the Mitochondrial Function of Macrophage via the PI3K/AKT/mTOR Signaling Pathway.

The repair of critical-sized bone defects continues to pose a challenge in clinics. Strontium (Sr), recognized for its function in bone metabolism regulation, has shown potential in bone repair. However, the underlying mechanism through which Sr2+ guided favorable osteogenesis by modulating macrophages remains unclear, limiting their application in the design of bone biomaterials. Herein, Sr-incorporated bioactive glass (SrBG) was synthesized for further investigation. The release of Sr ions enhanced the immunomodulatory properties and osteogenic potential by modulating the polarization of macrophages toward the M2 phenotype. In vivo, a 3D-printed SrBG scaffold was fabricated and showed consistently improved bone regeneration by creating a prohealing immunological microenvironment. RNA sequencing was performed to explore the underlying mechanisms. It was found that Sr ions might enhance the mitochondrial function of macrophage by activating PI3K/AKT/mTOR signaling, thereby favoring osteogenesis. Our findings demonstrate the relationship between the immunomodulatory role of Sr ions and the mitochondrial function of macrophages. By focusing on the mitochondrial function of macrophages, Sr2+-mediated immunomodulation sheds light on the future design of biomaterials for tissue regenerative engineering.

IRE1α pathway: A potential bone metabolism mediator.

Osteoblasts and osteoclasts collaborate in bone metabolism, facilitating bone development, maintaining normal bone density and strength, and aiding in the repair of pathological damage. Endoplasmic reticulum stress (ERS) can disrupt the intracellular equilibrium between osteoclast and osteoblast, resulting in dysfunctional bone metabolism. The inositol-requiring enzyme-1α (IRE1α) pathway-the most conservative unfolded protein response pathway activated by ERS-is crucial in regulating cell metabolism. This involvement encompasses functions such as inflammation, autophagy, and apoptosis. Many studies have highlighted the potential roles of the IRE1α pathway in osteoblasts, chondrocytes, and osteoclasts and its implication in certain bone-related diseases. These findings suggest that it may serve as a mediator for bone metabolism. However, relevant reviews on the role of the IRE1α pathway in bone metabolism remain unavailable. Therefore, this review aims to explore recent research that elucidated the intricate roles of the IRE1α pathway in bone metabolism, specifically in osteogenesis, chondrogenesis, osteoclastogenesis, and osteo-immunology. The findings may provide novel insights into regulating bone metabolism and treating bone-related diseases.

Targeting SAT1 prevents osteoporosis through promoting osteoclast apoptosis

Osteoporosis is a systemic bone disease characterized by decreased bone mass that is tightly regulated by the coordinated actions of osteoclasts and osteoblasts. Apoptosis as a precise programmed cell death involves a cascade of gene expression events which are mechanistically linked to the regulation of bone metabolism. Nevertheless, the critical biomolecules involved in regulating cell apoptosis in osteoporosis remain unknown. To gain a deeper insight into the relationship between apoptosis and osteoporosis, this study integrated the sequencing results of human samples and using a machine learning workflow to overcome the limitations of a single study. Among all immune cell populations, we assessed the apoptotic level and portrayed the distinct subtypes and lineage differentiation of monocytic cells in osteoporotic tissues. Osteoclasts expressed a higher level of Spermidine/spermine-N1-Acetyltransferase1 (SAT1) during osteoclastogenesis which prevented osteoclasts apoptosis and facilitate osteoporosis progression. In addition, Berenil, one potent SAT1 inhibitor, increased osteoclast apoptosis and reversed the bone loss in the femurs of a murine ovariectomy model. In summary, Berenil promotes osteoclast apoptosis, inhibits the bone resorption and improves the abnormal bone structure in vitro and in vivo models by targeting SAT1, demonstrating its potential as a precise therapeutic strategy for clinical osteoporosis treatment.

Research progress of circRNA as a biomarker of osteoporosis.

Osteoporosis, as a chronic metabolic bone disease, has the characteristic of insidious disease progression, which often leads to relatively delayed disease diagnosis. Therefore, early screening for osteoporosis has become a major public health challenge. The latest research indicates that circRNA is widely involved in the regulation of bone metabolism and is closely related to the occurrence and development of osteoporosis. Based on its high degree of sequence conservation and stability, circRNA has the potential to become a new clinical biomarker. The study of biomarkers is generally based on body fluid samples or adjacent tissue samples, with blood being the most commonly used, which can be divided into sources such as serum, plasma, peripheral blood monocytes, and plasma exosomes. Therefore, this article aims to review the research status of circRNA as a biomarker of osteoporosis.

Chromium nanoparticles improve bone turnover regulation in rats fed a high-fat, low-fibre diet.

The aim of the study was to investigate the effect of returning to a balanced diet combined with chromium picolinate (CrPic) or chromium nanoparticles (CrNPs) supplementation at a pharmacologically relevant dose of 0.3 mg/kg body weight on the expression level of selected genes and bone turnover markers in the blood and bones of rats fed an obese diet. The results of the study showed that chronic intake of a high-fat obesogenic diet negatively affects bone turnover by impairing processes of both synthesis and degradation of bones. The switch to a healthy diet proved insufficient to regulate bone metabolism disorders induced by an obesogenic diet, even when it was supplemented with chromium, irrespective of its form. Supplementation with CrPic with no change in diet stimulated bone metabolism only at the molecular level, towards increased osteoclastogenesis (bone resorption). In contrast, CrNPs added to the high-fat diet effectively regulated bone turnover by increasing both osteoblastogenesis and osteoclastogenesis, with these changes directed more towards bone formation. The results of the study suggest that unfavourable changes in bone metabolism induced by chronic intake of a high-fat diet can be mitigated by supplementation with CrNPs, whereas a change in eating habits fails to achieve a similar effect.

Integrating Network Pharmacology, Quantitative Metabolic Network Analysis, In Vitro Experiments, and Molecular Dynamics to Explore the Mechanism of Angelica Sinensis for Regulating Bone Metabolism.

Bone metabolic diseases are serious health issues worldwide. Angelica sinensis (AS) is traditionally used in Chinese medicine for treating bone metabolism diseases clinically. However, the mechanism of AS in regulating bone metabolism remains uncertain. The current investigation was structured to elucidate the potential mechanisms of AS for modulating bone metabolism. Firstly, targets of AS regulating bone metabolism were collected by network pharmacology. Then, the transcriptional regulation of RUNX2 was enriched as one of the key pathways for AS to regulate bone metabolism, constructing its metabolic network. Secondly, combining molecular docking, network efficiency, and network flux analyses, we conducted a quantitative evaluation of the metabolic network to reveal the potential mechanisms and components of AS regulating bone metabolism. Finally, we explored the effect of AS on the differentiation of osteoclasts from M-CSF and RANKL-induced RAW264.7 cells, as well as its impact on the osteogenic induction of MC3T3-E1 cells. We verified the mechanism and key targets of AS on bone metabolism using qRT-PCR. Furthermore, the key component was preliminarily validated through molecular dynamics simulation. Quantitative metabolic network of the transcriptional regulation of RUNX2 was constructed to illustrate the potential mechanism of AS for regulating bone metabolism, indicating that ferulic acid may be a pharmacological component of AS that interferes with bone metabolism. AS suppressed osteoclast differentiation in M-CSF and RANKL-induced RAW264.7 cells and reversed the expressions of osteoclastic differentiation markers, including RUNX2 and SRC. Additionally, AS induced osteogenic generation in MC3T3-E1 cells and reversed the expressions of markers associated with osteoblastic generation, such as RUNX2 and HDAC4. Molecular dynamics simulation displayed a strong binding affinity among ferulic acid, HDAC4 and SRC. This study reveals a systematic perspective on the intervention bone mechanism of AS by transcriptive regulation by RUNX2, guiding the clinical use of AS in treating diseases of the skeletal system.

Hydrolyzed egg yolk peptide prevented osteoporosis by regulating Wnt/β-catenin signaling pathway in ovariectomized rats

Hydrolyzed egg yolk peptide (YPEP) was shown to increase bone mineral density in ovariectomized rats. However, the underlying mechanism of YPEP on osteoporosis has not been explored. Recent studies have shown that Wnt/β-catenin signaling pathway and gut microbiota may be involved in the regulation of bone metabolism and the progression of osteoporosis. The present study aimed to explore the preventive effect of the YPEP supplementation on osteoporosis in ovariectomized (OVX) rats and to verify whether YPEP can improve osteoporosis by regulating Wnt/β-catenin signaling pathway and gut microbiota. The experiment included five groups: sham surgery group (SHAM), ovariectomy group (OVX), 17-β estradiol group (E2: 25 µg /kg/d 17β-estradiol), OVX with low-dose YPEP group (LYPEP: 10 mg /kg/d YPEP) and OVX with high-dose YPEP group (HYPEP: 40 mg /kg/d YPEP). In this study, all the bone samples used were femurs. Micro-CT analysis revealed improvements in both bone mineral density (BMD) and microstructure by YPEP treatment. The three-point mechanical bending test indicated an enhancement in the biomechanical properties of the YPEP groups. The serum levels of bone alkaline phosphatase (BALP), bone gla protein (BGP), calcium (Ca), and phosphorus (P) were markedly higher in the YPEP groups than in the OVX group. The LYPEP group had markedly lower levels of alkaline phosphatase (ALP), tartrate-resistant acid phosphatase (TRAP) and C-terminal telopeptide of type I collagen (CTX-I) than the OVX group. The YPEP groups had significantly higher protein levels of the Wnt3a, β-catenin, LRP5, RUNX2 and OPG of the Wnt/β-catenin signaling pathway compared with the OVX group. Compared to the OVX group, the ratio of OPG/RANKL was markedly higher in the LYPEP group. At the genus level, there was a significantly increase in relative abundance of Lachnospiraceae_NK4A136_group and a decrease in Escherichia_Shigella in YPEP groups, compared with the OVX group. However, in the correlation analysis, there was no correlation between these two bacteria and bone metabolism and microstructure indexes. These findings demonstrate that YPEP has the potential to improve osteoporosis, and the mechanism may be associated with its modulating effect on Wnt/β-catenin signaling pathway.

Calcium-fortified fresh milk ameliorates postmenopausal osteoporosis via regulation of bone metabolism and gut microbiota in ovariectomized rats

The aging of the global population has made postmenopausal osteoporosis prevention essential; however, pharmacological treatments are limited. Herein, we evaluate the effect of calcium-fortified fresh milk (FM) in ameliorating postmenopausal osteoporosis in a rat model established using bilateral ovariectomy. After 3 months of FM (containing vitamin D, and casein phosphopeptides, 1000 mg Ca/100 g) or control milk (110 mg Ca/100 g milk) supplementation, bone changes were assessed using dual-energy X-ray absorptiometry, microcomputed tomography, and bone biomechanical testing. The results revealed that FM can regulate bone metabolism and gut microbiota composition, which act on bone metabolism through pathways associated with steroid hormone biosynthesis, relaxin signaling, serotonergic synapse, and unsaturated fatty acid biosynthesis. Furthermore, FM administration significantly increased bone mineral content and density in the lumbar spine and femur, as well as femoral compressive strength, while improving femoral trabecular bone parameters and microarchitecture. Mechanistically, we found that the effects may be due to increased levels of estrogen, bone formation marker osteocalcin, and procollagen type I N-propeptide, and decreased expression of the bone resorption marker C-telopeptide and tartrate-resistant acid phosphatase 5b. Overall, the findings suggest that FM is a potential alternative therapeutic option for ameliorating postmenopausal osteoporosis.

Research Progress of Eucommia ulmoides Oliv and Predictive Analysis of Quality Markers Based on Network Pharmacology.

Du Zhong is a valuable Chinese medicinal herb unique to China. It is a national second- class precious protected tree, known as "plant gold", which has been used to treat various diseases since ancient times. The main active ingredients are lignans, phenylprophetons, flavonoids, iridoids and steroids and terpenoids, which have pharmacological effects such as lowering blood pressure, enhancing immunity, regulating bone metabolism, protecting nerve cells, protecting liver and gallbladder and regulating blood lipids. In this paper, a comprehensive review of Eucommia ulmoides Oliv. was summarized from the processing and its compositional changes, applications, chemical components, pharmacological effects, and pharmacokinetics, and the Q-marker of Eucommia ulmoides Oliv. is preliminarily predicted from the aspects of traditional efficacy, medicinal properties and measurability of chemical composition, and the pharmacodynamic substance basis and potential Q-marker of Eucommia ulmoides Oliv. are further analyzed through network pharmacology. It is speculated that quercetin, kaempferol, β-sitosterol, chlorogenic acid and pinoresinol diglucoside components are selected as quality markers of Eucommia ulmoides Oliv., which provide a basis for the quality control evaluation and follow-up research and development of Eucommia ulmoides Oliv.