An overview and management of osteoporosis

Proteomics and genomics insights on malignant osteosarcoma

Osteosarcoma is a malignant osseous neoplasm. Osteosarcoma is a primary bone malignancy capable of producing osteoid tissue or immature bones. A subsequent malignant degeneration of the primary bone pathology occurs less frequently in adults. The over-expression of several proteins, including Heat shock proteins, Cofilin, Annexins, Insulin-like growth factor, transforming growth factor-β, Receptor tyrosine kinase, Ezrin, Runx2, SATB2, ATF4, Annexins, cofilin, EGFR, VEGF, retinoblastoma 1 (Rb1) and secreted protein, has been associated to the development and progression of osteosarcoma. These proteins are involved in cell adhesion, migration, invasion, and the control of cell cycle and apoptosis. In genomic studies, osteosarcoma has been associated with several genetic abnormalities, including chromosomal rearrangements, gene mutations, and gene amplifications. These differentially expressed proteins could be used as early identification biomarkers or treatment targets. Proteomics and genomics play significant parts in enhancing our molecular understanding of osteosarcoma, and their integration provides essential insights into this aggressive bone cancer. This review will discuss the tumour biology that has assisted in helping us better understand the causes of osteosarcoma and how they could potentially be used to find new treatment targets and enhance the survival rate for osteosarcoma patients.

[Oridonin suppresses the effect of thioacetamide for promoting osteoclast differentiation of RAW264.7 cells and inhibiting osteoblast differentiation of bone mesenchymal stem cells]

OBJECTIVE

To explore the effect of oridonin (ORI) for suppressing thioacetamide (TAA)-induced osteoclast differentiation of RAW264.7 cells and antagonizing the inhibitory effect of TAA on osteogenic differentiation of bone mesenchymal stem cells (BMSCs).

METHODS

The effects of TAA and ORI on the proliferation of RAW264.7 cells and SD rat BMSCs were examined using CCK-8 assay. TRAP staining and immunofluorescence staining were used to observe the effects of TAA and ORI on osteoclast differentiation in RAW264.7 cells. The expressions of osteoclast-specific proteins in the treated cells were detected using Western blotting, and p65 nuclear translocation and reactive oxygen species (ROS) production in the cells were assessed with immunofluorescence assay and flow cytometry. Alkaline phosphatase (ALP) staining and alizarin red staining were used to examine the effects of TAA and ORI on osteogenic differentiation of BMSCs, and the expressions of osteogenic and apoptosis-related proteins in the cells were detected with Western blotting.

RESULTS

Compared with RAW264.7 cells treated with TAA alone, the cells with the combined treatment with TAA and ORI showed decreased osteoclast differentiation (P < 0.01) and significant inhibition of the MAPK/NF-κB pathway (P < 0.01) with reduced p65 nuclear translocation and intracellular ROS production (P < 0.01). In rat BMSCs, treatment with TAA alone significantly inhibited ALP activity and formation of calcified nodules (P < 0.01) and induced obvious cell apoptosis. Compared with TAA-treated BMSCs, the cells treated with both TAA and ORI showed upregulated expressions of the BMP-2/RUNX2 pathway with enhanced ALP activity (P < 0.01) and calcium deposition (P < 0.01) and a lowered cell apoptosis level.

CONCLUSION

ORI inhibits TAA-induced osteoclast differentiation via regulating the MAPK/NF-κB pathway and antagonizes TAA-induced inhibition of bone formation by regulating the BMP-2/RUNX2 pathway.

The Molecular Role of Polyamines in Age-Related Diseases: An Update

Polyamines (Pas) are short molecules that exhibit two or three amine groups that are positively charged at a physiological pH. These small molecules are present in high concentrations in a wide variety of organisms and tissues, suggesting that they play an important role in cellular physiology. Polyamines include spermine, spermidine, and putrescine, which play important roles in age-related diseases that have not been completely elucidated. Aging is a natural process, defined as the time-related deterioration of the physiological functions; it is considered a risk factor for degenerative diseases such as cardiovascular, neurodegenerative, and musculoskeletal diseases; arthritis; and even cancer. In this review, we provide a new perspective on the participation of Pas in the cellular and molecular processes related to age-related diseases, focusing our attention on important degenerative diseases such as Alzheimerߣs disease, Parkinsonߣs disease, osteoarthritis, sarcopenia, and osteoporosis. This new perspective leads us to propose that Pas function as novel biomarkers for age-related diseases, with the main purpose of achieving new molecular alternatives for healthier aging.

Approach to the Patient With Bone Fracture: Making the First Fracture the Last

The global burden of osteoporosis and osteoporotic fractures will increase significantly as we enter a rapidly aging population. Osteoporotic fractures lead to increased morbidity, mortality, and risk of subsequent fractures if left untreated. However, studies have shown that the majority of patients who suffer an osteoporotic fracture are not investigated or treated for osteoporosis, leading to an inexcusable "osteoporosis care gap." Systematic and coordinated models of care in secondary fracture prevention known as fracture liaison services (FLS) have been established to streamline and improve the care of patients with osteoporotic fractures, and employ core principles of identification, investigation, and initiation of treatment. Our approach to the multifaceted care of secondary fracture prevention at a hospital-based FLS is illustrated through several case vignettes.

A comprehensive review on environmental pollutants and osteoporosis: Insights into molecular pathways

A significant problem that has an impact on community wellbeing is environmental pollution. Environmental pollution due to air, water, or soil pollutants might pose a severe risk to global health, necessitating intense scientific effort. Osteoporosis is a common chronic condition with substantial clinical implications on mortality, morbidity, and quality of life. It is closely linked to bone fractures. Worldwide, osteoporosis affects around 200 million people, and every year, there are almost 9 million fractures. There is evidence that certain environmental factors may increase the risk of osteoporosis in addition to traditional risk factors. It is crucial to understand the molecular mechanisms at play because there is a connection between osteoporosis and exposure to environmental pollutants such as heavy metals, air pollutants, endocrine disruptors, metal ions and trace elements. Hence, in this scoping review, we explore potential explanations for the link between pollutants and bone deterioration through deep insights into molecular pathways. Understanding and recognizing these pollutants as modifiable risk factors for osteoporosis would possibly help to enhance environmental policy thereby aiding in the improvement of bone health and improving patient quality of life.

Spine, hip, and femoral neck bone mineral density in relation to vegetarian type and status among Taiwanese adults

We determined the association of vegetarian type and status with bone mineral density (BMD) Z-scores at the spine, hip, and femoral neck. Compared to non-vegetarians, current vegetarians, especially vegans, lacto-vegetarians, and lacto-ovo-vegetarians had lower Z-scores at multiple sites. Sole reliance on a vegetarian diet might be detrimental to the bone.

PURPOSE

The impact of vegetarian diets on BMD is contentious. We determined the association of vegetarian type and status with the spine, hip, and femoral neck BMD Z-scores.

METHODS

We analyzed data from 20,110 Taiwan Biobank volunteers. BMD was measured using dual-energy X-ray absorptiometry (DXA). The vegetarian status (non-, former, and current vegetarians) and type (non-vegetarians, ovo-vegetarians, lacto-vegetarians, lacto-ovo-vegetarians, and vegans) were determined using questionnaires.

RESULTS

The participants consisted of 12,910 women and 7200 men, with a mean age of 55.5 years. Based on vegetarian status (reference: non-vegetarians), current vegetarians had significantly lower BMD Z-scores at the spine (unstandardized regression coefficient, B =  - 0.195, p = 0.006), left hip (B =  - 0.125, p = 0.008), and right hip (B =  - 0.100, p = 0.027), respectively. Based on vegetarian status and type (reference: non-vegetarians), current vegans and non-vegans had notably lower BMD Z-scores at specific skeletal sites. For non-vegans, the BMD Z-scores were significant at the spine (B = -0.184, p = 0.010), left hip (B =  - 0.124, p = 0.010), and left femoral neck (B =  - 0.125, p = 0.012). For current vegans, however, the BMD Z-scores were significant only at the right hip (B =  - 0.232; p = 0.028). Nonetheless, after stratifying vegetarian diet into more subgroups, current vegans exhibited a significant reduction in BMD Z-scores at the spine and right hip, with B-coefficients of - 0.326 and - 0.238, respectively. Current lacto-vegetarians also had significantly lower Z-scores (p < 0.05) at the spine (B =  - 0.459), left hip (B =  - 0.313), and right hip (B =  - 0.214). Moreover, current lacto-ovo-vegetarians had significantly lower Z-scores at the spine (B =  - 0.175) and left hip (B =  - 0.115).

CONCLUSION

Current vegetarians, particularly vegans, lacto-vegetarians, and lacto-ovo-vegetarians, demonstrated significantly lower BMD Z-scores at various skeletal sites compared to non-vegetarians. Sole reliance on a vegetarian diet might be detrimental to the bone.

Modulation of the vitamin D/vitamin D receptor system in osteoporosis pathogenesis: insights and therapeutic approaches

Osteoporosis is a prevalent bone disorder characterized by low bone mineral density (BMD) and deteriorated bone microarchitecture, leading to an increased risk of fractures. Vitamin D (VD), an essential nutrient for skeletal health, plays a vital role in maintaining bone homeostasis. The biological effects of VD are primarily mediated through the vitamin D receptor (VDR), a nuclear receptor that regulates the transcription of target genes involved in calcium and phosphate metabolism, bone mineralization, and bone remodeling. In this review article, we conduct a thorough literature search of the PubMed and EMBASE databases, spanning from January 2000 to September 2023. Utilizing the keywords "vitamin D," "vitamin D receptor," "osteoporosis," and "therapy," we aim to provide an exhaustive overview of the role of the VD/VDR system in osteoporosis pathogenesis, highlighting the most recent findings in this field. We explore the molecular mechanisms underlying VDR's effects on bone cells, including osteoblasts and osteoclasts, and discuss the impact of VDR polymorphisms on BMD and fracture risk. Additionally, we examine the interplay between VDR and other factors, such as hormonal regulation, genetic variants, and epigenetic modifications, that contribute to osteoporosis susceptibility. The therapeutic implications of targeting the VDR pathway for osteoporosis management are also discussed. By bringing together these diverse aspects, this review enhances our understanding of the VD/VDR system's critical role in the pathogenesis of osteoporosis and highlights its significance as a potential therapeutic target.

Effect of the phosphorylation structure in casein phosphopeptides on the proliferation, differentiation, and mineralization of osteoblasts and its mechanism

Our previous studies have shown that highly phosphorylated casein phosphopeptides (residues 1-25) P5 could efficiently bind calcium and promote intestinal calcium absorption, and enhanced bone development in rats. The purpose of this study was to investigate the effect of the phosphorylation structure in P5 on the proliferation, differentiation, and mineralization of osteoblasts (MC3T3-E1) and its mechanism. P5 was obtained by high-performance liquid chromatography (HPLC) and non-phosphorylated peptide P5-0 was obtained by chemical synthesis. Compared with the control group, the proliferation rate of MC3T3-E1 cells treated by P5 was 1.10 times that of P5-0 at 200 μg mL-1. P5 caused the cell cycle retention of MC3T3-E1 cells in the G2/M phase, while P5-0 had no significant difference in the G2/M phase. MC3T3-E1 cells incubated with P5 showed stronger alkaline phosphatase (ALP) activity than with P5-0, suggesting a tendency to promote cellular differentiation. Compared to the P5-0 treatment group, the P5 treatment group at concentrations of 10 μg mL-1 showed significant differences in the mineralization rates (p < 0.05). P5 significantly upregulated the expressions of Runx2, ALP, ColIα1, and OCN compared with the control group (p < 0.05). In addition, in silico molecular docking showed that the binding force of the P5-EGFR complex was stronger than that of the P5-0-EGFR complex, which was significantly related to the phosphorylation structure in P5 and might be an important reason for osteoblast proliferation. In conclusion, the phosphorylation structure and amino acid composition in P5 stimulated the osteogenic activity of MC3T3-E1 cells, and could be expected to be a functional food for the prevention of osteoporosis.

Recent advance of small-molecule drugs for clinical treatment of osteoporosis: A review

Osteoporosis is a metabolic bone disorder typified by a reduction in bone mass and structural degradation of bone tissue, leading to heightened fragility and vulnerability to fractures. The incidence of osteoporosis increases with age, making it a significant public health challenge. The pathogenesis of osteoporosis involves an imbalance between osteoblast-mediated bone formation and resorption. The current treatment options for osteoporosis include bisphosphonates, hormone replacement therapy (HRT), selective estrogen receptor modulators (SERMs), and denosumab. The recent advances in small-molecule drugs for the clinical treatment of osteoporosis offer promising options for improving bone health and reducing fracture risk. This review aims to provide an overview of the clinical applications and synthetic routes of representative small-molecule drugs for the treatment of osteoporosis. A comprehensive understanding of the synthetic methods of drug molecules for osteoporosis may inspire the development of new, more effective, and practical synthetic techniques for treating this condition.

Application of Optical Photothermal Infrared (O-PTIR) Spectroscopy for Assessment of Bone Composition at the Submicron Scale

The molecular basis of bone structure and strength is mineralized collagen fibrils at the submicron scale (∼500 nm). Recent advances in optical photothermal infrared (O-PTIR) spectroscopy allow the investigation of bone composition with unprecedented submicron spatial resolution, which may provide new insights into factors contributing to underlying bone function. Here, we investigated (i) whether O-PTIR-derived spectral parameters correlated to standard attenuated total reflection (ATR) Fourier transform infrared spectroscopy spectral data and (ii) whether O-PTIR-derived spectral parameters, including heterogeneity of tissue, contribute to the prediction of proximal femoral bone stiffness. Analysis of serially demineralized bone powders showed a significant correlation (r = 0.96) between mineral content quantified using ATR and O-PTIR spectroscopy, indicating the validity of this technique in assessing bone mineralization. Using femoral neck sections, the principal component analysis showed that differences between O-PTIR and ATR spectra were primarily attributable to the phosphate ion (PO4) absorbance band, which was typically shifter toward higher wavenumbers in O-PTIR spectra. Additionally, significant correlations were found between hydrogen phosphate (HPO4) content (r = 0.75) and carbonate (CO3) content (r = 0.66) quantified using ATR and O-PTIR spectroscopy, strengthening the validity of this method to assess bone mineral composition. O-PTIR imaging of individual trabeculae at 500 nm pixel resolution illustrated differences in submicron composition in the femoral neck from bones with different stiffness. O-PTIR analysis showed a significant negative correlation (r = -0.71) between bone stiffness and mineral maturity, reflective of newly formed bone being an important contributor to bone function. Finally, partial least squares regression analysis showed that combining multiple O-PTIR parameters (HPO4 content and heterogeneity, collagen integrity, and CO3 content) could significantly predict proximal femoral stiffness (R2 = 0.74, error = 9.7%) more accurately than using ATR parameters. Additionally, we describe new findings in the effects of bone tissue orientation in the O-PTIR spectra. Overall, this study highlights a new application of O-PTIR spectroscopy that may provide new insights into molecular-level factors underlying bone mechanical competence.

Method for Evaluating Cortical Bone Young's Modulus: Numerical Twin Reconstruction, Finite Element Calculation, and Microstructure Analysis

The determination of bone mechanical properties remains crucial, especially to feed up numerical models. An original methodology of inverse analysis has been developed to determine the longitudinal elastic modulus of femoral cortical bone. The method is based on a numerical twin of a specific three-point bending test. It has been designed to be reproducible on each test result. In addition, the biofidelity of the geometric acquisition method has been quantified. As the assessment is performed at the scale of a bone shaft segment, the Young's modulus values obtained (between 9518.29 MPa and 14181.15 MPa) are considered average values for the whole tissue, highlighting some intersubject variability. The material microstructure has also been studied through histological analysis, and bone-to-bone comparisons highlighted discrepancies in quadrants microstructures. Furthermore, significant intrasubject variability exists since differences between the bone's medial-lateral and anterior-posterior quadrants have been observed. Thus, the study of microstructures can largely explain the differences between the elastic modulus values obtained. However, a more in-depth study of bone mineral density would also be necessary and would provide some additional information. This study is currently being setup, alongside an investigation of the local variations of the elastic modulus.

Tobacco toxins induce osteoporosis through ferroptosis

Clinical epidemiological studies have confirmed that tobacco smoking disrupts bone homeostasis and is an independent risk factor for the development of osteoporosis. The low viability and inferior osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) are important etiologies of osteoporosis. However, few basic studies have elucidated the specific mechanisms that tobacco toxins devastated BMSCs and consequently induced or exacerbated osteoporosis. Herein, our clinical data showed the bone mineral density (BMD) values of femoral neck in smokers were significantly lower than non-smokers, meanwhile cigarette smoke extract (CSE) exposure led to a significant decrease of BMD in rats and dysfunction of rat BMSCs (rBMSCs). Transcriptomic analysis and phenotype experiments suggested that the ferroptosis pathway was significantly activated in CSE-treated rBMSCs. Accumulated intracellular reactive oxygen species activated AMPK signaling, furtherly promoted NCOA4-mediated ferritin-selective autophagic processes, increased labial iron pool and lipid peroxidation deposition, and ultimately led to ferroptosis in rBMSCs. Importantly, in vivo utilization of ferroptosis and ferritinophagy inhibitors significantly alleviated BMD loss in CSE-exposed rats. Our study innovatively reveals the key mechanism of smoking-related osteoporosis, and provides a possible route targeting on the perspective of BMSC ferroptosis for future prevention and treatment of smoking-related bone homeostasis imbalance.

The correlation between osteoporotic vertebrae fracture risk and bone mineral density measured by quantitative computed tomography and dual energy X-ray absorptiometry: a systematic review and meta-analysis

This paper presents a comparison of quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA) in osteoporosis with vertebral fracture and osteoporosis without fracture. It has been proved that the volumetric bone mineral density (vBMD) measured by QCT exhibits a stronger correlation with fracture risk than areal bone mineral density (aBMD) measured by DXA.

PURPOSE

This study aims to systematically evaluate the ability of QCT and DXA to distinguish between osteoporosis with vertebral fracture and osteoporosis without fracture according to vBMD and aBMD.

METHODS

We conducted a primary literature search of the online databases up to 3 July, 2022, in both English and Chinese publications, combining synonyms for "QCT", "DXA" and "osteoporosis". The Newcastle-Ottawa scale (NOS) was employed to evaluate the quality of the selected articles. vBMD obtained through QCT and aBMD obtained through DXA were extracted, and were analyzed by Review Manager 5.4 and RStudio.

RESULTS

Six studies with 610 individuals aged 45 to 90, of which 179 had vertebral fractures, were included in the final analysis. The weighted mean difference (WMD) between osteoporosis with vertebral fracture and osteoporosis without fracture for vBMD was - 27.08 (95% CI  - 31.24 to  - 22.92), while for aBMD was - 0.05 (95% CI - 0.08 to - 0.03).

CONCLUSIONS

Both vBMD detected by QCT and aBMD detected by DXA could discriminate fracture status in the spine, and vBMD performed a stronger correlation with fracture risk.

TRIAL REGISTRATION

PROSPERO 2022 CRD42022349185.

A review on therapeutic mechanism of medicinal plants against osteoporosis: effects of phytoconstituents

Osteoporosis is a metabolic bone disorder that over time results in bone loss and raises the risk of fracture. The condition is frequently silent and only becomes apparent when fractures develop. Osteoporosis is treated with pharmacotherapy as well as non-pharmacological therapies such as mineral supplements, lifestyle changes, and exercise routines. Herbal medicine is frequently used in clinical procedures because of its low risk of adverse effects and cost-effective therapeutic results. In the current review, we have used a thorough strategy to identify some known medicinal plants with anti-osteoporosis capabilities, their origin, active ingredients, and pharmacological information. Furthermore, several signaling pathways, such as the apoptotic pathway, transcription factors, the Wnt/-catenin signaling pathway, and others, are regulated by bioactive components and help to improve bone homeostasis. This review will provide a better understanding of the anti-osteoporotic effects of bioactive components and the concomitant modulations of signaling pathways.

In vitro mechanical analysis of X-shaped femoroplasty with polymethyl methacrylate boundary a fall on the greater trochanter. Injury 2023;54 Suppl 6:110747. [PMID: 38143120 DOI: 10.1016/j.injury.2023.04.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

To evaluate with mechanical testing (MT) using synthetic femurs, an X-shaped femoroplasty technique with polymethyl methacrylate (PMMA), analyzing the results applied to the prophylaxis of proximal femur (PF) fractures caused by low-energy trauma. MT was performed simulating a fall on the greater trochanter, using fifteen Sawbones™ models. They were divided into three experimental groups (n = 5): control (DP) group, drilled without augmentation (DWA) group, and X-shaped augmentation (DX) group. Maximum load, stiffness, absorbed energy and displacement were analyzed primarily in all groups; and secondarily then, morphology and fracture type were verified in all groups while PMMA volume, temperature and time polymerization were analyzed only in the DX group. The MT results obtained for synthetic models respectively in the DP, DWA, and DX groups were: mean maximum load (5562.0 ± 464.8) N, (4798.0 ± 121.2) N, and (7132.0 ± 206.9) N; mean stiffness values (673 ± 64.34) N/mm, (636 ± 8.7) N/mm, and (738 ± 17.13) N/mm, and mean absorbed energy values (36,203 ± 3819) N.mm, (27,617 ± 3011) N.mm, (44,762 ± 3219) N.mm; mean displacement values (13.6 ± 1.45) N, (11.1 ± 0.5) N, and (13.2 ± 0.69) N. The mean volume, temperature reached during filling in the DX group were 9.8 mL, 42.54ºC with 1' 56" of polymerization. The fracture types were similar between the DP and DWA groups, affecting the trochanteric region, as distinctly to those in the DX group, which were restricted to the femoral neck. The values obtained in MT showed statistical significance when analyzed by one-way ANOVA (5%) for maximum load, stiffness, and absorbed energy between groups. In conclusion, X-shaped PMMA augmentation presents a protective biomechanical characteristic against PF fractures generated in synthetic models by boundary a fall on the greater trochanter.

Telomere length as a predictive biomarker in osteoporosis (Review)

Telomeres are the ends of chromosomes that protect them from DNA damage. There is evidence to suggest that telomere shortening appears with advanced age. Since aging is a significant risk factor for developing age-related complications, it is plausible that telomere shortening may be involved in the development of osteoporosis. The present review summarizes the potential of telomere shortening as a biomarker for detecting the onset of osteoporosis. For the purposes of the present review, the following scientific databases were searched for relevant articles: PubMed/NCBI, Cochrane Library of Systematic Reviews, Scopus, Embase and Google Scholar. The present review includes randomized and non-randomized controlled studies and case series involving humans, irrespective of the time of their publication. In six out of the 11 included studies providing data on humans, there was at least a weak association between telomere length and osteoporosis, with the remaining studies exhibiting no such association. As a result, telomere shortening may be used as a biomarker or as part of a panel of biomarkers for tracking the onset and progression of osteoporosis.

Microwave-assisted synthesis of novel steroidal heterocyclic analogs as potent inhibitors of RANKL-induced osteoclastogenesis

Osteoporosis is a significant public health issue in our aging population. It is an excessive bone resorption condition brought on by osteoclastogenesis, which makes bones more brittle. In the present work, a series of novel heterosteroidal derivatives have been synthesized using the microwave technique and were evaluated as antiosteoclastogenic agents. The structures of the newly synthesized compounds have been confirmed using analytical and spectral data. The antiosteoclastogenic activity of the newly synthesized compounds was estimated in vitro against osteoclast-differentiated cells from the RAW 264.7 cell line. The pregnenolone dimer 10, the pyridinotestosterone derivative 2, and the phenylnicotinonitrile pregnenolone derivative 8a attained the most promising antiosteoclastogenic activity displaying IC50 (the half maximal inhibitory concentration) values of 5.45 ± 5.30, 11.88 ± 2.09, and 13.40 ± 3.00 µM, respectively, in comparison with dimethyl itaconate (IC50  = 17.76 ± 3.20 µM) and alendronate (IC50  = 4.48 ± 1.89 µM) as reference compounds. Finally, an in silico ADME (Absorption, Distribution, Metabolism, and Excretion) study was conducted to evaluate the synthesized compounds' pharmacokinetic and drug-likeness properties. The results manifested that almost all the investigated compounds' properties were compatible with the specified optimal range, which indicates their reassuring pharmacokinetic properties.

External devices increasing bone quality in animals: A systematic review

Background: Osteoporosis can reduce bone quality and increase the risk of fractures. In addition to pharmacological approaches, physical activity, and implanted devices, external devices can also be detected in the literature as a technique to strengthen bones. This type of intervention arises to be particularly promising because it minimizes the invasiveness of therapy. Methods: A systematic review of the technologies involved in such devices was carried out to identify the most fruitful ones in improving bone quality. This review, according to the PRISMA Statement, focuses on studies involving animals, and excludes pharmaceutical approaches. Findings: The animal models and devices used, their settings, interventions, outcomes measured, and consequent effect on bone quality are reported for each detected technology. Ultrasound and laser arose to be the most studied technologies in the literature, even if they have yet to be proved to have a significant effect on bone quality. Interpretation: External devices for bone quality improvement offer a non-invasive approach that causes minimum discomfort to the patient. This review aimed to detect which technologies reported in the literature significantly affect bone quality. The results showed that several technologies are currently used to improve bone quality. However, each study measures different outcomes and uses different measurement methods, device settings, and interventions. This lack of standardization and the reduced number of articles found do not allow for proper quantitative comparisons.

Apoptosis pathways and osteoporosis: An approach to genomic analysis

BACKGROUND

Osteoporosis is a disease of the bone system that causes a decrease in skeletal density and degrades skeletal tissue. Decreased bone quality, so that bones are easily broken, damaged and fractured, is an important public health problem. Previous studies have shown that the maintenance of adult bone mass is not only due to changes in bone marrow and bone cells. By regulating apoptosis, they change the lifespan of each individual. This study influences understanding of the function of apoptosis in the pathogenesis of osteoporosis and the importance of controlling the mechanisms of osteoporosis.

METHODS

On the National Institute of Biotechnology Information website, Gene Expression Omnibus (GEO) microarray data and GSE551495 GEO profiles were collected. The gene set enrichment analysis tool was used to confirm the enrichment of genetic sets in relation to the gene set. The collection of C2 gene sets is compiled from the KEGG (https://www.gsea-msigdb.org/gsea/msigdb/human/search.jsp and https://www.kegg.jp/kegg/) online database and REACTOME (https://www.gsea-msigdb.org/gsea/msigdb/human/search.jsp and https://reactome.org/) pathway analysis. The Search Tool for the Retrieval of Interaction Genes (STRING) website was used to construct and select proteins and genes. The comparative toxicological genomic database (CTD) tools can be used to predict the relationship between apoptosis, osteoporosis-related genes and interactions between central genes and osteoporosis.

RESULTS

These results generally expand our understanding of the path of apoptosis in osteoporosis. We have discovered genes CASP9, CASP8, CASP3, BAX and TP53 associated with osteoporosis. In activation of KEGG apoptosis and REACTOME, caspase activation through the extrinsic apoptotic signaling pathway is characterized by the identification of a subcollection of C2. Other STRINGs show the formation of protein networks and central gene selection, and CTD can accurately predict the relationship between these apoptosis pathways and central genes.

CONCLUSIONS

Our research has highlighted the importance of the osteoporosis pathway associated with osteoporosis apoptosis with several analytical approaches. These results have broadened our understanding of the pathways of osteoporosis apoptosis. It is particularly possible to predict the sensitivity and vulnerability to osteoporosis.

Dietary Isoquercetin Ameliorates Bone Loss via Restoration of the Gut Microbiota and Lipopolysaccharide-Triggered Inflammatory Status in Ovariectomy Mice

Osteoporosis is one of the skeletal degenerative diseases accompanied by bone loss and microstructure disruption. Given that the gut-bone signaling axis highly contributes to bone health, here, dietary isoquercetin (IQ) was shown to effectively improve postmenopausal osteoporosis (PMO) in an ovariectomy (OVX) mouse model through the modulation of the gut-bone cross-talk. An in vivo study showed that OVX induced striking disruption of the microbial community, subsequently causing gut leakage and gut barrier dysfunction. As a result, lipopolysaccharide (LPS)-triggered inflammatory cytokines released from the intestine to bone marrow were determined to be associated with bone loss in OVX mice. Long-term dietary IQ effectively improved microbial community and gut barrier function in the OVX mice and thus markedly improved bone loss and host inflammatory status by repressing the NF-κB signaling pathway. An in vitro study further revealed that IQ treatments dose-dependently inhibited LPS-induced inflammation and partly promoted the proliferation and differentiation of osteoblasts. These results provide new evidence that dietary IQ has the potential for osteoporosis treatment.

Osteoporosis as Perceived by Saudi Physicians: A Cross-Sectional Study of Quality of Practice and Current Barriers in Management

Background Osteoporosis (OP) is a state of abnormal bone quality and architecture that leads to fragility fractures, with lifetime costs reaching 16.27 billion Saudi Arabian Riyal (SAR). Methods An electronic survey was distributed to physicians from July 2020 to May 2021 to assess the quality of the practice of physicians toward OP and barriers in OP management in Saudi Arabia. Specialties included were endocrinology, general medicine, family medicine, primary care, orthopedic surgery, rheumatology, obstetrics and gynecology, and geriatrics. Results A total of 177 surveys were eligible (55.9% female and 44.1% male). The majority were family consultants (42.9%). In terms of knowledge, 18.1% of our sample recognized all risk factors, and 24.9% recognized all indications to assess bone density. A central dual-energy X-ray absorptiometry (DEXA) was accessible to only 49.4% of the sample. Over 80% of the sample performed comprehensive laboratory workup. Although 68.4% of participants were aware of fracture risk assessment (FRAX), 53.7% used it in their practice. The most cited barrier was a lack of physicians' awareness (80.2%), followed by a lack of patients' awareness (63.6%). The specialty was significantly associated with the awareness of the densitometry certificate (P-value < 0.0001) and the use of FRAX (P-value = 0.0001). Conclusion Our results revealed a below-satisfactory quality of practice among Saudi physicians toward OP. Additionally, our results identified many gaps in knowledge and many barriers to optimal care.

Therapeutic potential in rheumatic diseases of extracellular vesicles derived from mesenchymal stromal cells

The incidence of rheumatic diseases such as rheumatoid arthritis and osteoarthritis and injuries to articular cartilage that lead to osteochondral defects is predicted to rise as a result of population ageing and the increase in high-intensity physical activities among young and middle-aged people. Current treatments focus on the management of pain and joint functionality to improve the patient's quality of life, but curative strategies are greatly desired. In the past two decades, the therapeutic value of mesenchymal stromal cells (MSCs) has been evaluated because of their regenerative potential, which is mainly attributed to the secretion of paracrine factors. Many of these factors are enclosed in extracellular vesicles (EVs) that reproduce the main functions of parental cells. MSC-derived EVs have anti-inflammatory, anti-apoptotic as well as pro-regenerative activities. Research on EVs has gained considerable attention as they are a potential cell-free therapy with lower immunogenicity and easier management than whole cells. MSC-derived EVs can rescue the pathogenetic phenotypes of chondrocytes and exert a protective effect in animal models of rheumatic disease. To facilitate the therapeutic use of EVs, appropriate cell sources for the production of EVs with the desired biological effects in each disease should be identified. Production and isolation of EVs should be optimized, and pre-isolation and post-isolation modifications should be considered to maximize the disease-modifying potential of the EVs.

Unraveling the Relationship Between Osteoporosis, Treatment Modalities, and Oral Health: A Comprehensive Review

This review delves into the intricate interplay between osteoporosis, its treatment approaches, and oral health. The examination underscores the substantial impact of osteoporosis, characterized by reduced bone density, on various oral health parameters such as periodontal health, tooth loss, and jawbone density. While pharmacological interventions, including bisphosphonates and hormone replacement therapy, play a crucial role in managing osteoporosis, they necessitate careful consideration, particularly about the risk of osteonecrosis of the jaw. A comprehensive approach involving collaboration between dentists and healthcare providers is imperative for holistic patient care. Implementing screening protocols for osteoporosis in dental settings and meticulously planning dental procedures for patients undergoing osteoporosis treatments are vital aspects of clinical practice. This review also sheds light on emerging trends in osteoporosis research, such as the influence of genetic factors and the microbiome, emphasizing the necessity for innovative treatment modalities. In conclusion, the review provides valuable insights into the nuanced connections between osteoporosis and oral health, thereby laying a foundation for informed clinical practices and guiding future research initiatives. Furthermore, it highlights the importance of optimizing dental procedures and assessing long-term oral health outcomes as critical avenues for future research endeavors.

MiR-210 promotes bone formation in ovariectomized rats by regulating osteogenic/adipogenic differentiation of bone marrow mesenchymal stem cells through downregulation of EPHA2

PURPOSE

In osteoporosis, the balance between osteogenic and adipogenic differentiation of mesenchymal stem cells (MSCs) is disrupted. The osteogenic differentiation of bone marrow MSCs (BMSCs) is important for improving osteoporosis. The aim of this study was to explore the role and molecular mechanism of miR-210 in the balance of osteogenic/adipogenic differentiation of BMSCs in postmenopausal osteoporosis.

METHODS

Postmenopausal osteoporosis rat models were constructed by ovariectomy (OVX). BMSCs were isolated from the femur in rats of Sham and OVX groups. MiR-210 was overexpressed and suppressed by miR-210 mimics and inhibitor, respectively. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the relative mRNA expression of miR-210, ephrin type-A receptor 2 (EPHA2), alkaline phosphatase (ALP), osterix (OSX), osteocalcin (Bglap), Runt-related transcription factor 2 (Runx2), peroxisome proliferator activated receptor gamma, and fatty acid binding protein 4 (FABP4) in each group of rat femoral tissues or BMSCs. Western blot was applied to detect the protein expression level of EPHA2 in rat femoral tissues and cells. Alizarin red S staining and oil red O staining were performed to assess the osteogenic and adipogenic differentiation of BMSCs, respectively. In addition, the targeting relationship between miR-210 and EPHA2 was verified by a dual luciferase gene reporter assay.

RESULTS

The expression of miR-210 was significantly reduced in femoral tissues and BMSCs of OVX rats, and its low expression was associated with reduced bone formation. The osteogenic differentiation was enhanced in OVX rats treated with miR-210 mimic. Overexpression of miR-210 in transfected BMSCs was also found to significantly promote osteogenic differentiation and even inhibit adipogenic differentiation in BMSCs, while knockdown of miR-210 did the opposite. Further mechanistic studies showed that miR-210 could target and inhibit the expression of EPHA2 in BMSCs, thus promoting osteogenic differentiation and inhibiting adipogenic differentiation of BMSCs.

CONCLUSION

MiR-210 promotes osteogenic differentiation and inhibits adipogenic differentiation of BMSCs by down-regulating EPHA2 expression. As it plays an important role in the osteogenic/adipogenic differentiation of osteoporosis, miR-210 can serve as a potential miRNA biomarker for osteoporosis.

Molecular and Cellular Mechanisms of Osteoporosis

Osteoporosis is a widespread systemic disease characterized by a decrease in bone mass and an imbalance of the microarchitecture of bone tissue. Experimental and clinical studies devoted to investigating the main pathogenetic mechanisms of osteoporosis revealed the important role of estrogen deficiency, inflammation, oxidative stress, cellular senescence, and epigenetic factors in the development of bone resorption due to osteoclastogenesis, and decreased mineralization of bone tissue and bone formation due to reduced function of osteoblasts caused by apoptosis and age-depended differentiation of osteoblast precursors into adipocytes. The current review was conducted to describe the basic mechanisms of the development of osteoporosis at molecular and cellular levels and to elucidate the most promising therapeutic strategies of pathogenetic therapy of osteoporosis based on articles cited in PubMed up to September 2023.

The associations of alcoholic liver disease and nonalcoholic fatty liver disease with bone mineral density and the mediation of serum 25-Hydroxyvitamin D: A bidirectional and two-step Mendelian randomization

BACKGROUND

Reduced bone mineral density (BMD) and osteoporosis are common in chronic liver diseases. However, the causal effect of alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) on BMD remains uncertain.

OBJECTIVES

This study uses a two-sample Mendelian randomization (MR) design to evaluate the genetically predicted effect of ALD and NAFLD on BMDs using summary data from publically available genome-wide association studies (GWASs).

METHODS

The GWAS summary statistics of ALD (1416 cases and 213,592 controls) and NAFLD (894 cases and 217,898 controls) were obtained from the FinnGen consortium. BMDs of four sites (total body, n = 56,284; femoral neck, n = 32,735; lumbar spine, n = 28,498; forearm, n = 8143) were from the GEnetic Factors for OSteoporosis Consortium. Data for alcohol consumption (n = 112,117) and smoking (n = 33,299) and serum 25-Hydroxyvitamin D (25-OHD) level (n = 417,580) were from UK-biobank. We first performed univariate MR analysis with the Inverse Variance Weighted (IVW) method as the primary analysis to investigate the genetically predicted effect of ALD or NAFLD on BMD. Then, multivariate MR and mediation analysis were performed to identify whether the effect was mediated by alcohol consumption, smoking, or serum 25-OHD level.

RESULTS

The MR results suggested a robust genetically predicted effect of ALD on reduced BMD in the femoral neck (FN-BMD) (IVW beta = -0.0288; 95% CI: -0.0488, -0.00871; P = 0.00494) but not the other three sites. Serum 25-OHD level exhibited a significant mediating effect on the association between ALD and reduced FN-BMD albeit the proportion of mediation was mild (2.21%). No significant effects of NAFLD, alcohol consumption, or smoking on BMD in four sites, or reverse effect of BMD on ALD or NAFLD were detected.

CONCLUSION

Our findings confirm the genetically predicted effect of ALD on reduced FN-BMD, and highlight the importance of periodic BMD and serum 25-OHD monitoring and vitamin D supplementation as needed in patients with ALD. Future research is required to validate our results and investigate the probable underlying mechanisms.

Phytosterols Protect against Osteoporosis by Regulating Gut Microbiota

Osteoporosis is increasingly prevalent worldwide, representing a major health burden. However, there is a lack of nutritional strategies for osteoporotic therapy. Phytosterols, as natural bioactive compounds, have the potential to alleviate osteoporosis. In this study, a glucocorticoid-induced osteoporosis mouse model and treatment with low and high concentrations of phytosterols for 4 weeks were established. The results demonstrated that compared to the control group, low-concentration phytosterols (LP) (0.3 mg/mL) increased bone mass, improved trabecular microstructure, reduced serum levels of cross-linked C-telopeptide of type I collagen (CTX-1), and elevated serum levels of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3). Conversely, high-concentration phytosterols (0.5 mg/mL) showed no effect. Additionally, we validated the effect of LP in ameliorating osteoporosis using an ovariectomized (OVX)-induced osteoporosis mouse model. Mechanistically, phytosterols altered the microbial composition to counteract glucocorticoid-induced gut microbiota disorder and improve the length and morphology of the small intestine. Particularly, based on selection strategy and correlation analysis, phytosterols increased the relative abundance of Ruminococcus and decreased the relative abundance of Bilophila, which were significantly associated with glucocorticoid-induced osteoporosis indications. Overall, these findings suggest that phytosterols regulate gut microbiota to increase bone mass, thereby exerting an antiosteoporotic effect.

Advances in the Development of Nano-Engineered Mechanically Robust Hydrogels for Minimally Invasive Treatment of Bone Defects

Injectable hydrogels were discovered as attractive materials for bone tissue engineering applications given their outstanding biocompatibility, high water content, and versatile fabrication platforms into materials with different physiochemical properties. However, traditional hydrogels suffer from weak mechanical strength, limiting their use in heavy load-bearing areas. Thus, the fabrication of mechanically robust injectable hydrogels that are suitable for load-bearing environments is of great interest. Successful material design for bone tissue engineering requires an understanding of the composition and structure of the material chosen, as well as the appropriate selection of biomimetic natural or synthetic materials. This review focuses on recent advancements in materials-design considerations and approaches to prepare mechanically robust injectable hydrogels for bone tissue engineering applications. We outline the materials-design approaches through a selection of materials and fabrication methods. Finally, we discuss unmet needs and current challenges in the development of ideal materials for bone tissue regeneration and highlight emerging strategies in the field.

Reduction quality in lateral view of X-ray and hypoalbuminemia are associated with postoperative mortality in elderly pertrochanteric fracture patients

Background

Pertrochanteric fracture is one of the most prevalent public health issues across the world for the elderly population. The purpose of this study was to investigate the association between surgical factors and postoperative mortality in patients with intramedullary nail-treated pertrochanteric fractures.

Methods

A retrospective cohort study was designed to evaluate the pertrochanteric fracture patients treated with intramedullary nail between January 2016 to February 2021. The surgical factors included the Dorr morphology, Arbeitsgemeinschaft für Osteosynthesefragen/Orthopedic Trauma Association (AO/OTA) classification of fractures, the tip-apex distance (TAD), location of the cephalic screw, reduction quality in anterior-posterior (AP) and lateral views, the integrity of the lateral wall, and the design of cephalic screws. Using univariate and multivariate Cox proportional hazard models, the association between these risk factors and postoperative mortality in patients with this type of fractures was evaluated.

Results

A total of 169 pertrochanteric fracture patients treated with intramedullary nails were included in our study, with the average age of 82.68±5.93 years. The mortality rates at 3 months, 1 year, and the end of follow-up were 4.14%, 11.24%, and 26.04%, respectively. According to the univariate Cox analysis, age, gender, preoperative levels of hemoglobin (Hb) and albumin (Alb) were associated with a poor overall survival (OS) (P<0.05). After multivariate adjustment, the pre-operative level of Alb (P<0.001) and the reduction in lateral view (P<0.001) were shown to be independent risk factors for poor OS.

Conclusions

The preoperative hypoalbuminemia and reduction quality in lateral view were associated with postoperative mortality in our study. Therefore, optimizing both parameters could improve the prognosis in elderly pertrochanteric fracture patients.

Benefits for cardiovascular system, bone density, and quality of life of a long-term hormone therapy in hysterectomized women: a 20-year follow-up study

OBJECTIVE

The safety, consequences, and dosage of long-term hormone therapy (HT) for postmenopausal women remain unclear. Our aim was to analyze the effects of HT after 20 years of therapy in women after hysterectomy, focusing on the symptoms of menopause, blood pressure, lipid profiles, and bone density.

METHODS

A prospective observational longitudinal study was designed. The initial transdermal estradiol dose was reduced in half (0.025 mg/d) at 60 years of age. Different parameters including demographic, cardiovascular, bone density, and metabolic variables, as well as quality of life characteristics, were analyzed using bivariate analyses. Multivariate generalized estimating equations for longitudinal data were fitted for differences over time and between doses (<60 vs ≥60 y) using the R package geepack.

RESULTS

After 20 years of HT, the mean age of 56 studied hysterectomized women was 67.1 years. The mean Kupperman index score decreased from 26.7 to 12.0 ( P < 0.001). A trend with total and low-density lipoprotein cholesterol reduction and high-density lipoprotein cholesterol increase was observed over time. A decrease in very-low-density lipoprotein cholesterol ( P = 0.05) and an increase in T score vertebral densitometry ( P = 0.014) were detected after HT. No changes in health outcome were detected in women older than 60 years with the reduced dose of HT. Breast cancer was the reason for dropouts in 0.02% women.

CONCLUSIONS

HT for up to 20 years after hysterectomy may be beneficial for bone and cardiovascular health and for the overall quality of life. Our data suggest the importance of evaluating the dose and the timing of HT.

Gleditsiae fructus regulates osteoclastogenesis by inhibiting the c‑Fos/NFATc1 pathway and alleviating bone loss in an ovariectomy model

Medical and economic developments have allowed the human lifespan to extend and, as a result, the elderly population has increased worldwide. Osteoporosis is a common geriatric disease that has no symptoms and even a small impact can cause fractures in patients, leading to a serious deterioration in the quality of life. Osteoporosis treatment typically involves bisphosphonates and selective estrogen receptor modulators. However, these treatments are known to cause severe side effects, such as mandibular osteonecrosis and breast cancer, if used for an extended period of time. Therefore, it is essential to develop therapeutic agents from natural products that have fewer side effects. Gleditsiae fructus (GF) is a dried or immature fruit of Gleditsia sinensis Lam. and is composed of various triterpenoid saponins. The anti‑inflammatory effect of GF has been confirmed in various diseases, and since the anti‑inflammatory effect plays a major role in inhibiting osteoclast differentiation, GF was expected to be effective in osteoclast differentiation and menopausal osteoporosis; however, to the best of our knowledge, it has not yet been studied. Therefore, the present study was designed to examine the effect of GF on osteoclastogenesis and to investigate the mechanism underlying inhibition of osteoclast differentiation. The effects of GF on osteoclastogenesis were determined in vitro by tartrate‑resistant acid phosphatase (TRAP) staining, pit formation assays, filamentous actin (F‑actin) ring formation assays, western blotting and reverse transcription‑quantitative PCR analyses. Furthermore, the administration of GF to an animal model exhibiting menopausal osteoporosis allowed for the analysis of alterations in the bone microstructure of the femur using micro‑CT. Additionally, assessments of femoral tissue and serum were conducted. The present study revealed that the administration of GF resulted in a reduction in osteoclast levels, F‑actin rings, TRAP activity and pit area. Furthermore, GF showed a dose‑dependent suppression of nuclear factor of activated T‑cells cytoplasmic, c‑Fos and other osteoclastogenesis‑related markers.

Citric acid-modified pH-sensitive bone-targeted delivery of estrogen for the treatment of postmenopausal osteoporosis

Bone targeted delivery of estrogen offers great promise for the clinical application of estrogen in the treatment of postmenopausal osteoporosis (PMOP). However, the current bone-targeted drug delivery system still has several issues that need to be solved, such as the side effects of bone-targeted modifier molecules and the failure of the delivery system to release rapidly in the bone tissue. It is important to aggressively search for new bone-targeted modifier molecules and bone microenvironment-responsive delivery vehicles. Inspired by the distribution of citric acid (CA) mainly in bone tissue and the acidic bone resorption microenvironment, we constructed a CA-modified diblock copolymer poly(2-ethyl-2-oxazoline)-poly(ε-caprolactone) (CA-PEOz) drug delivery system. In our study, we found that the CA modification significantly increased the bone targeting of this drug delivery system, and the delivery system was able to achieve rapid drug release under bone acidic conditions. The delivery system significantly reduced bone loss in postmenopausal osteoporotic mice with a significant reduction in estrogenic side effects on the uterus. In summary, our study shows that CA can act as an effective bone targeting modifier molecule and provides a new option for bone targeting modifications. Our study also provides a new approach for bone-targeted delivery of estrogen for the treatment of PMOP.

Effects of an mHealth physical activity intervention to prevent osteoporosis in premenopausal women. A randomized controlled trial

OBJECTIVES

It is critical to develop prevention strategies for osteoporosis that reduce the burden fractures place on individuals and health systems. This study evaluated the effects of an mHealth intervention that delivered and monitored a non-supervised exercise program on bone mineral density (BMD).

DESIGN

Randomized controlled trial.

METHODS

60 premenopausal women aged 35-50 years were divided into an intervention group (IG) and a control group (CG). The IG followed a 6-month intervention aimed at increasing osteogenic physical activity, guided by two daily goals: walking at least 10,000 steps and completing 60 impacts over 4 g of acceleration. These goals were monitored using a wearable accelerometer linked to an mHealth app. The CG maintained their regular lifestyle and wore the accelerometer without feedback. BMD was estimated using dual-energy X-ray absorptiometry (DXA) scans at baseline and after 6 months, with group-by-time analyses conducted using ANCOVA. The intervention's impact on physical fitness and activity habits was also evaluated.

RESULTS

46 participants completed the study (IG = 24; CG = 22). The IG showed significant improvements compared to the CG in femoral neck BMD (IG: +0.003 ± 0.029 g/cm2 vs CG: -0.027 ± 0.031 g/cm2), trochanter BMD (IG: +0.004 ± 0.023 g/cm2 vs CG: -0.026 ± 0.030 g/cm2), and total hip BMD (IG: +0.006 ± 0.043 g/cm2 vs CG: -0.040 ± 0.048 g/cm2). The IG also demonstrated significant improvements in physical fitness measures, including peak torque and power at various speeds and positions. No adverse events related to the intervention were reported.

CONCLUSIONS

This non-supervised physical activity intervention delivered by wearable-technology and an mHealth app was effective in improving BMD, suggesting its potential for osteoporosis prevention.

Mediating role of host metabolites in strontium's effect on osteoporosis among older individuals: Findings from Wuhan, China

Strontium is receiving widespread attention due to its remarkable biological qualities in preventing bone resorption and fostering osteogenesis. However, the chemical processes behind strontium's dual activities on bone cells are not yet fully understood. This study used the metabolomic technique to identify and examine potential biomarkers between strontium exposure and osteoporosis (OP) risk. A total of 806 participants were recruited for the detection of plasma strontium content via inductively coupled plasma-mass spectrometry. Plasma metabolites were profiled in 254 participants through an untargeted metabolomics technique. Generalized linear models were primarily used to analyze associations among plasma strontium, metabolites, and OP. The mediating effects of metabolites on the strontium-OP association were further investigated. A total of 31 differential metabolites were observed, 10 of which were upregulated and 21 were downregulated in the OP group compared with the non-OP group. Five metabolites (3-phenoxybenzoic acid, Cer (t18:0/16:1), HexCer(t16:1/12:1(2OH)), HexCer(t14:2/18:1(2OH)), and TG(16:0-18:1-24:4)) were selected as potential mediators based on their significant association with OP risk and with femoral neck and lumbar spine bone mineral density (BMD). Moreover, all except TG(16:0-18:1-24:4) were involved in the OP discrimination model with excellent power combined with several traditional variables. 3-Phenoxybenzoic acid and Cer(t18:0/16:1) had significant indirect effects on the strontium-OP association. The five candidate metabolites mediated 83.79 % of the strontium-OP association. Plasma strontium level was associated with reduced OP risk in the Han population in Wuhan. Thus, plasma metabolite profiling revealed five BMD/OP-associated metabolites that acted as mediators in the strontium-OP association. Our findings provided evidence of the mediating role of host plasma metabolites in strontium's effect on OP pathology.

Mitochondrial Genetics and Function as Determinants of Bone Phenotype and Aging

PURPOSE OF REVIEW

The purpose of this review is to summarize the recently published scientific literature regarding the effects of mitochondrial function and mitochondrial genome mutations on bone phenotype and aging.

RECENT FINDINGS

While aging and sex steroid levels have traditionally been considered the most important risk factors for development of osteoporosis, mitochondrial function and genetics are being increasingly recognized as important determinants of bone health. Recent studies indicate that mitochondrial genome variants found in different human populations determine the risk of complex degenerative diseases. We propose that osteoporosis should be among such diseases. Studies have shown the deleterious effects of mitochondrial DNA mutations and mitochondrial dysfunction on bone homeostasis. Mediators of such effects include oxidative stress, mitochondrial permeability transition, and dysregulation of autophagy. Mitochondrial health plays an important role in bone homeostasis and aging, and understanding underlying mechanisms is critical in leveraging this relationship clinically for therapeutic benefit.

Melatonin and bone-related diseases: an updated mechanistic overview of current evidence and future prospects

PURPOSE

Bone diseases account for an enormous cost burden on health systems. Bone disorders are considered as age-dependent diseases. The aging of world population has encouraged scientists to further explore the most effective preventive modalities and therapeutic strategies to overcome and reduce the high cost of bone disorders. Herein, we review the current evidence of melatonin's therapeutic effects on bone-related diseases.

METHODS

This review summarized evidences from in vitro, in vivo, and clinical studies regarding the effects of melatonin on bone-related diseases, with a focus on the molecular mechanisms. Electronically, Scopus and MEDLINE®/PubMed databases were searched for articles published on melatonin and bone-related diseases from inception to June 2023.

RESULTS

The findings demonstrated that melatonin has beneficial effect in bone- and cartilage-related disorders such as osteoporosis, bone fracture healing, osteoarthritis, and rheumatoid arthritis, in addition to the control of sleep and circadian rhythms.

CONCLUSION

A number of animal and clinical studies have indicated that various biological effects of melatonin may suggest this molecule as an effective therapeutic agent for controlling, diminishing, or suppressing bone-related disorders. Therefore, further clinical studies are required to clarify whether melatonin can be effective in patients with bone-related diseases.

Strontium-driven physiological to pathological transition of bone-like architecture: A dose-dependent investigation

Whilst strontium (Sr2+) is widely investigated for treating osteoporosis, it is also related to mineralization disorders such as rickets and osteomalacia. In order to clarify the physiological and pathological effects of Sr2+ on bone biomineralization , we performed a dose-dependent investigation in bone components using a 3D scaffold that displays the hallmark features of bone tissue in terms of composition (osteoblast, collagen, carbonated apatite) and architecture (mineralized collagen fibrils hierarchically assembled into a twisted plywood geometry). As the level of Sr2+ is increased from physiological-like to excess, both the mineral and the collagen fibrils assembly are destabilized, leading to a drop in the Young modulus, with strong implications on pre-osteoblastic cell proliferation. Furthermore, the microstructural and mechanical changes reported here correlate with that observed in bone-weakening disorders induced by Sr2+ accumulation, which may clarify the paradoxical effects of Sr2+ in bone mineralization. More generally, our results provide physicochemical insights into the possible effects of inorganic ions on the assembly of bone extracellular matrix and may contribute to the design of safer therapies for treating osteoporosis. STATEMENT OF SIGNIFICANCE: Physiological-like (10% Sr2+) and excess accumulation-like (50% Sr2+) doses of Sr2+ are investigated in 3D biomimetic assemblies possessing the high degree of organization found in the extracellular of bone. Above the physiological dose, the organic and inorganic components of the bone-like scaffold are destabilized, resulting in impaired cellular activity, which correlates with bone-weakening disorders induced by Sr2+.

Bone-Targeted Delivery of Cell-Penetrating-RUNX2 Fusion Protein in Osteoporosis Model

The onset of osteoporosis leads to a gradual decrease in bone density due to an imbalance between bone formation and resorption. To achieve optimal drug efficacy with minimal side effects, targeted drug delivery to the bone is necessary. Previous studies have utilized peptides that bind to hydroxyapatite, a mineral component of bone, for bone-targeted drug delivery. In this study, a hydroxyapatite binding (HAB) tag is fused to 30Kc19α-Runt-related transcription factor 2 (RUNX2) for bone-targeting. This recombinant protein can penetrate the nucleus of human mesenchymal stem cells (hMSCs) and act as a master transcription factor for osteogenesis. The HAB tag increases the binding affinity of 30Kc19α-RUNX2 to mineral deposition in mature osteoblasts and bone tissue, without affecting its osteogenic induction capability. In the osteoporosis mouse model, intravenous injection of HAB-30Kc19α-RUNX2 results in preferential accumulation in the femur and promotes bone formation while reducing toxicity in the spleen. These findings suggest that HAB-30Kc19α-RUNX2 may be a promising candidate for bone-targeted therapy in osteoporosis.

Effects of isoflavone and probiotic intake on calcium transport and bone metabolism biomarkers in female rats

Calcium is essential for maintaining bone health as it contributes to bone formation, remodeling, strength, and density. This study investigated the effect of isoflavones and probiotics on calcium transporters' gene expression, serum calcium levels, and bone metabolism biomarkers in healthy female rats. Forty-eight female Wistar rats were classified into six groups. Bone metabolism biomarkers (pyridinoline, deoxypyridinoline, parathyroid hormone, and osteocalcin) and serum calcium levels were measured by enzyme-linked immunosorbent assay (ELISA) and atomic absorption spectroscopy (AAS), respectively. Gene expression of calcium transporters (Trpv5 and Trpv6) was evaluated in duodenum and jejunum tissue samples using quantitative polymerase chain reaction (qPCR). Trpv5 and Trpv6, epithelial calcium channels, play a crucial role in calcium transport and homeostasis in the body. The study consisted of a1-week adaptation period for the rats to adjust to the controlled conditions, followed by an 8-week intervention phase. The daidzein and genistein group showed a significant increase in the gene expression of the Trpv6 transporter in the duodenum and a marked decrease in serum pyridinoline levels compared to the control group. The tempeh and soybean groups showed a significant decrease in the gene expression of the Trpv5 calcium transporter in the jejunum. However, no significant influence of the Lactobacillus acidophilus diet on calcium transport and bone metabolism biomarkers was observed in the L. acidophilus group. The correlation analysis showed a significant positive relationship between serum calcium, bone metabolism biomarkers, and calcium transporters. In conclusion, our study demonstrates that the daidzein and genistein diet improves calcium transport in the duodenum and reduces pyridinoline serum concentrations, while tempeh and soybean diets reduce calcium transport in the jejunum. However, the combination of daidzein, genistein, and L. acidophilus did not demonstrate a synergistic effect on calcium transport and bone metabolism, suggesting that further investigations are needed to elucidate their potential interactions.

Efficacy assessment of methylcellulose-based thermoresponsive hydrogels loaded with gallium acetylacetonate in osteoclastic bone resorption

Homeostatic imbalance involving progressive stimulation of osteoclast (OC) differentiation and function will lead to an increased risk of fragility fractures. In this regard, we investigated gallium acetylacetonate (GaAcAc) as a possible treatment for osteoclastic bone resorption. Further, the extent to which suitable delivery systems can enhance the therapeutic potential of GaAcAc was evaluated. GaAcAc solution (10-50 µg/mL) suppressed OC differentiation using murine monocytic RAW 264.7 or hematopoietic stem cells. Methylcellulose-based hydrogels were fabricated and characterized based on biocompatibility with bone cells, GaAcAc loading, and thermoresponsive behavior using storage (G') and loss (G″) moduli parameters. Compared to GaAcAc solution, hydrogels loaded with GaAcAc (GaMH) were more effective in suppressing OC differentiation and function. The number and extent of bone resorption pits from ex vivo studies were markedly reduced with GaMH treatment. Mechanistic assessment of GaMH efficacy showed superiority, compared to GaAcAc solution, in downregulating the expression of key markers involved in mediating OC differentiation (such as NFAT2, cFos, TRAF6, and TRAP) as well as in bone resorption by OCs (cathepsin K or CTSK). Additional studies (in vitro and in vivo) suggested that the performance of GaMH could be ascribed to controlled release of GaAcAc and the ability to achieve prolonged bio-retention after injection in BALB/c mice, which plausibly maximized the therapeutic impact of GaAcAc. Overall, the work demonstrated, for the first time, the therapeutic efficacy of GaAcAc and the therapeutic potential of GaMH delivery systems in osteoclastic bone resorption.

Water Extract of Angelica dahurica Inhibits Osteoclast Differentiation and Bone Loss

Angelica dahurica radix has a long history of traditional use in China and Korea for treating headaches, cold-damp pain and skin diseases. Despite various pharmacological studies on A. dahurica, its impact on bones remains unclear. Hence, this study investigated the inhibitory effect of A. dahurica's radix water extract (WEAD) on osteoclast differentiation. In vitro experiments showed that WEAD effectively suppresses osteoclast differentiation. Treatment of an osteoclast precursor with WEAD significantly suppressed the expression of nuclear factor of activated T-cells 1 (NFATc1), essential transcription factor for osteoclastogenesis, while increasing the expression of negative regulators, interferon regulatory factor 8 (Irf8) and v-maf musculoaponeurotic fibrosarcoma oncogene homolog B (MafB). Consistent with the in vitro findings, the oral administration of WEAD (100 and 300 mg/kg/day) to mice subjected to surgical ovariectomy for a duration of six weeks alleviated bone loss, while also mitigating weight gain and liver fat accumulation. In addition, we also identified phytochemicals present in WEAD, known to regulate osteoclastogenesis and/or bone loss. These results suggest the potential use of WEAD for treating various bone disorders caused by excessive bone resorption.

Romosozumab in osteoporosis: yesterday, today and tomorrow

Osteoporosis is a systemic bone disease characterized by low bone mass, microarchitectural deterioration, increased bone fragility, and fracture susceptibility. It commonly occurs in older people, especially postmenopausal women. As global ageing increases, osteoporosis has become a global burden. There are a number of medications available for the treatment of osteoporosis, categorized as anabolic and anti-resorptive. Unfortunately, there is no drugs which have dual influence on bone, while all drugs have limitations and adverse events. Some serious adverse events include jaw osteonecrosis and atypical femoral fracture. Recently, a novel medication has appeared that challenges this pattern. Romosozumab is a novel drug monoclonal antibody to sclerostin encoded by the SOST gene. It has been used in Japan since 2019 and has achieved promising results in treating osteoporosis. However, it is also accompanied by some controversy. While it promotes rapid bone growth, it may cause serious adverse events such as cardiovascular diseases. There has been scepticism about the drug since its inception. Therefore, the present review comprehensively covered romosozumab from its inception to its clinical application, from animal studies to human studies, and from safety to cost. We hope to provide a better understanding of romosozumab for its clinical application.

The beneficial effects of simultaneous supplementation of Lactobacillus reuteri and calcium fluoride nanoparticles on ovariectomy-induced osteoporosis

BACKGROUND

The development of new strategies to inhibit and/or treat osteoporosis as a chronic systemic disease is one of the most crucial topics. The present study aimed to investigate the simultaneous effects of calcium fluoride nanoparticles (CaF2 NPs) and lactobacillus reuteri ATCC PTA 6475 (L. reuteri) against osteoporosis in an ovariectomized rat model (OVX).

METHODS

In this study, 18 matured Wistar female rats were randomly assigned into 6 groups, including control, OVX, sham, OVX + L. reuteri, OVX + CaF2 NPs, and OVX + L. reuteri + CaF2 NPs. We used OVX rats to simulate post-menopausal osteoporosis, and the treatments were begun two weeks before OVX and continued for four weeks. All groups' blood samples were collected, and serum biomarkers (estrogen, calcium, vitamin D3, and alkaline phosphatase (ALP)) were measured. The tibia and Femur lengths of all groups were measured. Histopathological slides of tibia, kidney, and liver tissues were analyzed using the Hematoxylin and Eosin staining method.

RESULTS

Our results revealed that dietary supplementation of L. reuteri and CaF2 NPs in low doses for 6 weeks did not show adverse effects in kidney and liver tissues. The tibial and femoral lengths of OVX rats as well as the population of osteoblasts and osteocytes and newly generated osteoid in the tibia remarkably increased in the combination therapy group. Moreover, there was a significant increase in serum estrogen levels and a significant decrease in serum calcium and alkaline phosphatase levels in combination treatment groups compared to the OVX groups not receiving the diet.

CONCLUSIONS

Our results suggest the favorable effects of the simultaneous supplementation of L. reuteri and CaF2 NP to reduce post-menopausal bone loss.

Osteoporosis: Molecular Pathology, Diagnostics, and Therapeutics

Osteoporosis is a major public health concern affecting millions of people worldwide and resulting in significant economic costs. The condition is characterized by changes in bone homeostasis, which lead to reduced bone mass, impaired bone quality, and an increased risk of fractures. The pathophysiology of osteoporosis is complex and multifactorial, involving imbalances in hormones, cytokines, and growth factors. Understanding the cellular and molecular mechanisms underlying osteoporosis is essential for appropriate diagnosis and management of the condition. This paper provides a comprehensive review of the normal cellular and molecular mechanisms of bone homeostasis, followed by an in-depth discussion of the proposed pathophysiology of osteoporosis through the osteoimmunological, gut microbiome, and cellular senescence models. Furthermore, the diagnostic tools used to assess osteoporosis, including bone mineral density measurements, biochemical markers of bone turnover, and diagnostic imaging modalities, are also discussed. Finally, both the current pharmacological and non-pharmacological treatment algorithms and management options for osteoporosis, including an exploration of the management of osteoporotic fragility fractures, are highlighted. This review reveals the need for further research to fully elucidate the molecular mechanisms underlying the condition and to develop more effective therapeutic strategies.

Utilization of 3D bioprinting technology in creating human tissue and organoid models for preclinical drug research - State-of-the-art

Rapid development of tissue engineering in recent years has increased the importance of three-dimensional (3D) bioprinting technology as novel strategy for fabrication functional 3D tissue and organoid models for pharmaceutical research. 3D bioprinting technology gives hope for eliminating many problems associated with traditional cell culture methods during drug screening. However, there is a still long way to wider clinical application of this technology due to the numerous difficulties associated with development of bioinks, advanced printers and in-depth understanding of human tissue architecture. In this review, the work associated with relatively well-known extrusion-based bioprinting (EBB), jetting-based bioprinting (JBB), and vat photopolymerization bioprinting (VPB) is presented and discussed with the latest advances and limitations in this field. Next we discuss state-of-the-art research of 3D bioprinted in vitro models including liver, kidney, lung, heart, intestines, eye, skin as well as neural and bone tissue that have potential applications in the development of new drugs.

Dominoes with interlocking consequences triggered by zinc: involvement of microelement-stimulated MSC-derived exosomes in senile osteogenesis and osteoclast dialogue

As societal aging intensifies, senile osteoporosis has become a global public health concern. Bone microdamage is mainly caused by processes such as enhancing osteoclast activity or reducing bone formation by osteoblast-lineage cells. Compared with young individuals, extracellular vesicles derived from senescent bone marrow mesenchymal stem cells(BMSCs) increase the transient differentiation of bone marrow monocytes (BMMs) to osteoclasts, ultimately leading to osteoporosis and metal implant failure. To address this daunting problem, an exosome-targeted orthopedic implant composed of a nutrient coating was developed. A high-zinc atmosphere used as a local microenvironmental cue not only could inhibit the bone resorption by inhibiting osteoclasts but also could induce the reprogramming of senile osteogenesis and osteoclast dialogue by exosome modification. Bidirectional regulation of intercellular communication via cargoes, including microRNAs carried by exosomes, was detected. Loss- and gain-of-function experiments demonstrated that the key regulator miR-146b-5p regulates the protein kinase B/mammalian target of rapamycin pathway by targeting the catalytic subunit gene of PI3K-PIK3CB. In vivo evaluation using a naturally-aged osteoporotic rat femoral defect model further confirmed that a nutrient coating substantially augments cancellous bone remodeling and osseointegration by regulating local BMMs differentiation. Altogether, this study not only reveals the close link between senescent stem cell communication and age-related osteoporosis but also provides a novel orthopedic implant for elderly patients with exosome modulation capability.

A Highly Flexible Piezoelectric Ultrasonic Sensor for Wearable Bone Density Testing

Driven by the loss of bone calcium, the elderly are prone to osteoporosis, and regular routine checks on bone status are necessary, which mainly rely on bone testing equipment. Therefore, wearable real-time healthcare devices have become a research hotspot. Herein, we designed a high-performance flexible ultrasonic bone testing system using axial transmission technology based on quantitative ultrasound theory. First, a new rare-earth-element-doped PMN-PZT piezoelectric ceramic was synthesized using a solid-state reaction, and characterized by X-ray diffraction and SEM. Both a high piezoelectric coefficient d33 = 525 pC/N and electromechanical coupling factors of k33 = 0.77, kt = 0.58 and kp = 0.63 were achieved in 1%La/Sm-doped 0.17 PMN-0.47 PZ-0.36 PT ceramics. Combining a flexible PDMS substrate with an ultrasonic array, a flexible hardware circuit was designed which includes a pulse excitation module, ultrasound array module, amplification module, filter module, digital-to-analog conversion module and wireless transmission module, showing high power transfer efficiency and power intensity with values of 35% and 55.4 mW/cm2, respectively. Finally, the humerus, femur and fibula were examined by the flexible device attached to the skin, and the bone condition was displayed in real time on the mobile client, which indicates the potential clinical application of this device in the field of wearable healthcare.

Relationships among body weight, lipids and bone mass in elderly individuals with fractures: A case-control study

BACKGROUND

The prevalence of osteoporosis and low bone mass is steadily rising each year. Low body weight is commonly linked to diminished bone mass and serves as a robust predictor of osteoporosis. Nonetheless, the connection between body mass index (BMI), bone mineral density, and lipid profiles among the elderly remains elusive.

AIM

To examine the association between BMI and bone mass, explore the correlation between lipid profiles and bone mass, and delve into the interplay between lipid metabolism and bone health.

METHODS

The study included 520 patients aged ≥ 65 years (178 men and 342 women). Age, sex, weight, and height were recorded. Femoral neck bone mineral density and T scores were determined using a dual-energy X-ray absorptiometry scanner. Blood calcium (Ca), phosphorus (P), albumin (ALB), alkaline phosphatase (ALP), aspartate aminotransferase, alanine aminotransferase, triglyceride (TG), total cholesterol (TC), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) levels were measured. Patients were classified by sex (male and female), age (65-79 years and ≥ 80 years), and T score (normal bone mineral density, osteopenia and osteoporosis).

RESULTS

Age, sex, BMI, and ALP and TG levels were independent risk factors for osteoporosis. For the 65-79- and ≥ 80-year-old groups, females presented lower T scores than males. Ca, P, ALB, ALP, TC, HDL and LDL levels were significantly different between men and women in the 65-79-year-old group. In addition, BMI and TG levels were significantly decreased in osteoporotic patients compared with patients with normal bone mass. TC levels declined in 65- to 79-year-old male and female osteoporosis patients. In the group of women aged ≥ 80 years, osteoporotic patients showed significantly increased ALP levels. Furthermore, we found positive correlations between BMI and TG levels in the male and female patient groups. However, we found no significant differences in ALB, Ca, P, HDL and LDL levels in osteoporotic patients compared to patients with normal bone mass.

CONCLUSION

Osteoporotic patients showed significantly decreased BMI and TG levels compared with those with normal bone mass. BMI showed positive correlations with TG levels in male and female patients. These results indicate correlations between BMI and bone mass and between lipid profiles and bone mass.

Drug Delivery and Therapy Strategies for Osteoporosis Intervention

With the advent of the aging society, osteoporosis (OP) risk increases yearly. Currently, the clinical usage of anti-OP drugs is challenged by recurrent side effects and poor patient compliance, regardless of oral, intravenous, or subcutaneous administration. Properly using a drug delivery system or formulation strategy can achieve targeted drug delivery to the bone, diminish side effects, improve bioavailability, and prolong the in vivo residence time, thus effectively curing osteoporosis. This review expounds on the pathogenesis of OP and the clinical medicaments used for OP intervention, proposes the design approach for anti-OP drug delivery, emphatically discusses emerging novel anti-OP drug delivery systems, and enumerates anti-OP preparations under clinical investigation. Our findings may contribute to engineering anti-OP drug delivery and OP-targeting therapy.

Metal mixture and osteoporosis risk: Insights from plasma metabolite profiling

The pathophysiology of osteoporosis (OP) is influenced by exposure to nonessential harmful metals and insufficient or excessive intake of necessary metals. Investigating multiple plasma metals, metabolites, and OP risk among older adults may reveal novel clues of underlying mechanisms for metal toxicity on bone mass. A total of 294 adults ≥ 55 years from Wuhan communities were included. Plasma concentrations of 23 metals and metabolites were measured via inductively coupled plasma-mass spectrometry and global metabolite detection. To investigate the relationships between plasma metals, OP risk, and OP-related metabolites, three different statistical techniques were used: generalized linear regression model, two-way orthogonal partial least-squares analysis (O2PLS), and weighted quantile sum (WQS). The mean ages were 66.82 and 66.21 years in OP (n = 115) and non-OP (n = 179) groups, respectively. Of all 2999 metabolites detected, 111 differential between-group members were observed. The OP risk decreased by 58.5% (OR=0.415, 95% CI: 0.237, 0.727) per quartile increment in the WQS index indicative of metal mixture exposure. Consistency remained for bone mineral density (BMD) measurements. The O2PLS model identified the top five OP-related metabolites, namely, DG(18:2_22:6), 3-phenoxybenzoic acid, TG(16:1_16:1_22:6), TG(16:0_16:0_20:4), and TG(14:1_18:2_18:3), contributing most to the joint covariation between the metal mixture and metabolites. Significant correlations between each of them and the metal mixture were found using WQS regression. Furthermore, the five metabolites mediated the associations of the metal mixtures, BMD, and OP risk. Our findings shed additional light on the mediation functions of plasma metabolites in the connection between multiple metal co-exposure and OP pathogenesis and offer new insights into the probable mechanisms underpinning the bone effects of the metal mixture.