Menopausal hormone therapy for the management of osteoporosis

Relationship between menopausal hormone therapy and incidence of fractures in postmenopausal women

OBJECTIVE

Long-term protective effects of menopausal hormone therapy (MHT) at fractures with different doses and components are controversial. We analyzed the effect of MHT on the incidence of spine and femur fractures according to MHT type, age at commencement, duration and dose of hormones in Korean women.

METHOD

This retrospective study evaluated propensity score-matched patients with MHT from the Korean National Health Insurance Service database. Among women aged ≥50 years with menopause between 2004 and 2007, spine and femur fracture incidence until 2017 was analyzed in 36,446 women who had received MHT for >1 year. Estrogen-progesterone therapy (EPT), estrogen-only therapy (ET) or tibolone therapy was conducted.

RESULTS

EPT significantly lowered the incidence of spine and femur fractures with a conventional dose, but not with a low dose. Tibolone significantly decreased the incidence of spine fractures in women aged 50-59 years when used for >5 years, and the incidence of femur fractures in women older than 60 years when used for >3 years. ET significantly lowered the risk of femur fractures when estradiol was used for >5 years.

CONCLUSION

In menopausal women, all MHT including conventional-dose EPT, ET and tibolone tended to lower the incidence of fractures. The effects, however, varied with the type of fracture and type of MHT.

A novel mechanism of Vildagliptin in regulating bone metabolism and mitigating osteoporosis

Osteoporosis has become a global social problem with the tendency toward the aging population. The challenge in managing osteoporosis is to develop new anti-osteoporosis drugs that target bone anabolism. The purpose of this study was to uncover the novel mechanism of Vildagliptin on bone metabolism. We revealed that Vildagliptin significantly promoted osteogenic differentiation of precursor osteoblasts and bone marrow mesenchymal stem cells (BMSCs). At the same time, it significantly enhanced the polarization of RAW264.7 macrophages to the M2 type and the secretion of osteogenic factors BMP2 and TGF-β1. This was confirmed by the increased osteogenic differentiation observed in the osteoblast-RAW264.7 co-culture system. Moreover, Vildagliptin significantly enhanced the transformation of BMSCs into the osteogenic morphology in the osteoblast-BMSC co-culture system. Finally, Vildagliptin also inhibited osteoclastic differentiation of RAW 264.7 cells. The potential mechanism underlying these effects involved targeting the GAS6/AXL/ERK5 pathway. In the in vivo study, Vildagliptin significantly alleviated postmenopausal osteoporosis in ovariectomized mice. These findings represent the first comprehensive revelation of the regulatory effect of Vildagliptin on bone metabolism. Specifically, Vildagliptin demonstrates the ability to promote bone anabolism and inhibit bone resorption by simultaneously targeting osteoblasts, BMSCs, and osteoclasts. The bone-protective effects of Vildagliptin were further confirmed in a postmenopausal osteoporosis model. The clinical significance of this study lies in laying a theoretical foundation for bone protection therapy in type-2 diabetes patients with compromised bone conditions or postmenopausal osteoporosis.

Network pharmacology analysis and experimental validation to explore the mechanism of kaempferol in the treatment of osteoporosis

Osteoporosis (OP) is a prevalent global disease characterized by bone mass loss and microstructural destruction, resulting in increased bone fragility and fracture susceptibility. Our study aims to investigate the potential of kaempferol in preventing and treating OP through a combination of network pharmacology and molecular experiments. Kaempferol and OP-related targets were retrieved from the public database. A protein-protein interaction (PPI) network of common targets was constructed using the STRING database and visualized with Cytoscape 3.9.1 software. Enrichment analyses for GO and KEGG of potential therapeutic targets were conducted using the Hiplot platform. Molecular docking was performed using Molecular operating environment (MOE) software, and cell experiments were conducted to validate the mechanism of kaempferol in treating OP. Network pharmacology analysis identified 54 overlapping targets between kaempferol and OP, with 10 core targets identified. The primarily enriched pathways included atherosclerosis-related signaling pathways, the AGE/RAGE signaling pathway, and the TNF signaling pathway. Molecular docking results indicated stable binding of kaempferol and two target proteins, AKT1 and MMP9. In vitro cell experiments demonstrated significant upregulation of AKT1 expression in MC3T3-E1 cells (p < 0.001) with kaempferol treatment, along with downregulation of MMP9 expression (p < 0.05) compared to the control group. This study predicted the core targets and pathways of kaempferol in OP treatment using network pharmacology, and validated these findings through in vitro experiments, suggesting a promising avenue for future clinical treatment of OP.

Hormone replacement therapy and periodontitis progression in postmenopausal women: A prospective cohort study

OBJECTIVE

This study aimed to investigate the responses of periodontal environment to hormone replacement therapy (HRT) in postmenopausal women with or without periodontitis.

BACKGROUND

HRT is a common and effective strategy for controlling menopausal symptoms, while the changes of periodontal environment under it, particularly in postmenopausal women with periodontitis, remain unclear.

METHODS

As a prospective cohort study, a total of 97 postmenopausal women receiving HRT were screened, including 47 with and 50 without periodontitis. Correspondingly, 97 women did not receiving HRT were screened as controls during the same period. The full-mouth sulcus bleeding index (SBI), bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment level (CAL) were measured using periodontal probes. The levels of interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) in the gingival crevicular fluid were measured using enzyme-linked immunosorbent assay. In addition, cone beam computed tomography was performed to measure the alveolar bone height (ABH) and bone mineral density (BMD).

RESULTS

In postmenopausal women without periodontitis, no significantly changes on periodontal parameters were observed after HRT. In women with stage II periodontitis, SBI, BOP, IL-6, and TNF-α were significant decreased after one year and two years of HRT. Compared to the controls, women with stage II periodontitis who underwent HRT had significantly lower CAL and ABH and higher BMD in the second year. The incidence of at least one site with CAL increase ≥1 mm between baseline and 2 years was significantly lower in the HRT group than in the control group in women with stage II periodontitis. In addition, HRT was significantly associated with a decrease in SBI, BOP, IL-6, and TNF-α in the first year and with a decrease in CAL, SBI, BOP, IL-6, and ABH and an increase in BMD in the second year.

CONCLUSIONS

In postmenopausal women with stage II periodontitis, HRT is associated with the alleviation of inflammation within two years and the remission of alveolar bone loss in the second year. HRT appears to decrease the incidence of CAL increase ≥1 mm within 2 years in women with periodontitis by inhibiting inflammation and alveolar bone loss.

Oral Milk-Derived Extracellular Vesicles Inhibit Osteoclastogenesis and Ameliorate Bone Loss in Ovariectomized Mice by Improving Gut Microbiota

Milk-derived extracellular vesicles can improve intestinal health and have antiosteoporosis potential. In this paper, we explored the effects of bovine raw milk-derived extracellular vesicles (mEVs) on ovariectomized (OVX) osteoporotic mice from the perspective of the gut-bone axis. mEVs could inhibit osteoclast differentiation and improve microarchitecture. The level of osteoporotic biomarkers in OVX mice was restored after the mEVs intervened. Compared with OVX mice, mEVs could enhance intestinal permeability, reduce endotoxin levels, and improve the expression of TNF-α, IL-17, and IL-10. 16S rDNA sequencing indicated that mEVs altered the composition of gut microbiota, specifically for Bacteroides associated with short-chain fatty acids (SCFAs). In-depth analysis of SCFAs demonstrated that mEVs could restore acetic acid, propionic acid, valeric acid, and isovaleric acid levels in OVX mice. Correlation analysis revealed that changed gut microbiota and SCFAs were significantly associated with gut inflammation and osteoporotic biomarkers. This study demonstrated that mEVs could inhibit osteoclast differentiation and improve osteoporosis by reshaping the gut microbiota, increasing SCFAs, and decreasing the level of pro-inflammatory cytokines and osteoclast differentiation-related factors in OVX mice. These findings provide evidence for the use of mEVs as a food supplement for osteoporosis.

A systematic review of community pharmacy interventions to improve peri- and post-menopausal health

Menopause is defined as the permanent cessation of menstruation due to loss of ovarian follicular function. Symptoms include mood disorders, vaginal atrophy, hot flashes and night sweats and can emerge during a gradual transition period called perimenopause. Community pharmacies are well placed to deliver a wide range of healthcare services, including supporting and educating menopausal women; however, to date, no systematic review has assessed the effectiveness of community pharmacy-led interventions in improving peri- and post-menopausal health. In accordance with PRISMA guidelines we evaluated community pharmacy-led interventions that targeted women in peri- or post-menopause. Electronic searches in EMBASE, MEDLINE, CINAHL and Cochrane Library were conducted on 13th February 2023. Additionally, we examined the included studies references and citation lists using Google Scholar. A total of 915 articles were identified and screened against the inclusion criteria. Two studies were included; one identified post-menopausal women at risk of developing osteoporosis (OP), and one evaluated the outcomes of a community pharmacy-based menopause education programme. Study one found 11 (11%) post-menopausal women were at risk of developing OP based on quantitative ultrasound screening offered by community pharmacists and referred to their physician. Study two reported that women had access to adequate personalised menopause counselling and increased knowledge of menopause topics because of the educational programme within community pharmacies. Both studies were of low quality. The lack of included studies reflects the need for high-quality research to determine whether community pharmacy-led interventions are feasible, effective and acceptable, to improve health outcomes of peri- or post-menopausal women.

Insights and implications of sexual dimorphism in osteoporosis

Osteoporosis, a metabolic bone disease characterized by low bone mineral density and deterioration of bone microarchitecture, has led to a high risk of fatal osteoporotic fractures worldwide. Accumulating evidence has revealed that sexual dimorphism is a notable feature of osteoporosis, with sex-specific differences in epidemiology and pathogenesis. Specifically, females are more susceptible than males to osteoporosis, while males are more prone to disability or death from the disease. To date, sex chromosome abnormalities and steroid hormones have been proven to contribute greatly to sexual dimorphism in osteoporosis by regulating the functions of bone cells. Understanding the sex-specific differences in osteoporosis and its related complications is essential for improving treatment strategies tailored to women and men. This literature review focuses on the mechanisms underlying sexual dimorphism in osteoporosis, mainly in a population of aging patients, chronic glucocorticoid administration, and diabetes. Moreover, we highlight the implications of sexual dimorphism for developing therapeutics and preventive strategies and screening approaches tailored to women and men. Additionally, the challenges in translating bench research to bedside treatments and future directions to overcome these obstacles will be discussed.

Cardiovascular safety of zoledronic acid in the treatment of primary osteoporosis: A meta-analysis and systematic review

PURPOSE

Osteoporosis is intimately linked to cardiovascular disease and it has been uncertain that zoledronic acid is not correlated with cardiovascular disease. We intended to assess the cardiovascular safety of zoledronic acid in the treatment of primary osteoporosis.

METHODS

We included only randomized controlled trials (RCTs) of patients with osteoporosis receiving zoledronic acid or a placebo. We systematically searched PubMed, Embase, Web of Science, Cochrane CENTRAL, Scopus, the Chinese National Knowledge Infrastructure, ClinicalTrials.gov, and ICTRP from the time of database creation to April 5, 2023. Two investigators extracted data independently on study characteristics, outcomes of interest, and risk of bias based on PRISMA guidelines.

RESULTS

As of April 5, 2023, our search identified 32,361 records, and after excluding these records, 9 RCTs were included in the meta-analysis. The overall risk ratio for cardiovascular events with zoledronic acid for primary osteoporosis compared with placebo was 1.15 (95 % CI 1.05-1.26, I2=12 %, P = 0.002), while the risk of major adverse cardiovascular events with zoledronic acid (RR 1.03, 95 % CI 0. 89-1.18, I2=21 %, P = 0.71) was not significant, possibly due to atrial fibrillation (RR 1.21, 95 % CI 0.99-1.47, I2=0 %, P = 0.06) versus the increased relative risk of arrhythmia (RR 1.30, 95 % CI 1.11-1.52, I2=34 %, P = 0.001). Overall, the cardiovascular risk of zoledronic acid for the treatment of primary osteoporosis was not significant; however, the relative risk of elevated atrial fibrillation and arrhythmias remains to be further studied.

CONCLUSIONS

In women with primary osteoporosis, zoledronic acid may increase the risk of atrial fibrillation (P = 0.06) and arrhythmias (P = 0.001) compared with placebo, independent of the risk of major adverse cardiovascular events, angina, and heart failure. However, the sample size of men with primary osteoporosis is small, and the cardiovascular risk of zoledronic acid in men with osteoporosis is uncertain.

Research progress of targeted therapy regulating Th17/Treg balance in bone immune diseases

Rheumatoid arthritis (RA) and postmenopausal osteoporosis (PMOP) are common bone-immune diseases. The imbalance between helper (Th17) and regulatory T cells (Tregs) produced during differentiation of CD4+ T cells plays a key regulatory role in bone remodelling disorders in RA and PMOP. However, the specific regulatory mechanism of this imbalance in bone remodelling in RA and PMOP has not been clarified. Identifying the regulatory mechanism underlying the Th17/Treg imbalance in RA and PMOP during bone remodelling represents a key factor in the research and development of new drugs for bone immune diseases. In this review, the potential roles of Th17, Treg, and Th17/Treg imbalance in regulating bone remodelling in RA and PMOP have been summarised, and the potential mechanisms by which probiotics, traditional Chinese medicine compounds, and monomers maintain bone remodelling by regulating the Th17/Treg balance are expounded. The maintenance of Th17/Treg balance could be considered as an therapeutic alternative for the treatment of RA and PMOP. This study also summarizes the advantages and disadvantages of conventional treatments and the quality of life and rehabilitation of patients with RA and PMOP. The findings presented her will provide a better understanding of the close relationship between bone immunity and bone remodelling in chronic bone diseases and new ideas for future research, prevention, and treatment of bone immune diseases.

Attenuative effects of collagen peptide from milkfish (Chanos chanos) scales on ovariectomy-induced osteoporosis

Osteoporosis is characterized by low bone mass, bone microarchitecture disruption, and collagen loss, leading to increased fracture risk. In the current study, collagen peptides were extracted from milkfish scales (MS) to develop potential therapeutic candidates for osteoporosis. MS was used to synthesize a crude extract of fish scales (FS), collagen liquid (COL), and hydroxyapatite powder (HA). COL samples were further categorized according to the peptide size of total COL (0.1 mg/mL), COL < 1 kDa (0.1 mg/mL), COL: 1-10 kDa (0.1 mg/mL), and COL > 10 kDa (0.1 mg/mL) to determine it. Semi-quantitative reverse transcription polymerase chain reaction (sqRT-PCR) and immunofluorescence labeling were used to assess the expression levels of specific mRNA and proteins in vitro. For in vivo studies, mice ovariectomy (OVX)-induced postmenopausal osteoporosis were developed, while the sham surgery (Sham) group was treated as a control. Collagen peptides (CP) from MS inhibited osteoclast differentiation in RAW264.7 cells following an insult with nuclear factor kappa-B ligand (RANKL). CP also enhanced osteoblast proliferation in MG-63 cells, possibly through downregulating NFATc1 and TRAP mRNA expression and upregulating ALP and OPG mRNA levels. Furthermore, COL1 kDa also inhibited bone density loss in osteoporotic mice. Taken together, CP may reduce RANKL-induced osteoclast activity while promoting osteoblast synthesis, and therefore may act as a potential therapeutic agent for the prevention and control of osteoporosis.

Comparative efficacy of acupuncture-related therapy for postmenopausal osteoporosis: protocol for Bayesian network meta-analysis

INTRODUCTION

The review aims to conduct the first network meta-analysis to comprehensively evaluate the application of multiple acupuncture techniques in patients with postmenopausal osteoporosis, ranking the best acupuncture treatment and providing a reference for clinical treatment extensively.

METHODS AND ANALYSIS

Randomised controlled trials of different acupuncture-related therapies for postmenopausal osteoporosis will be searched in the following databases from 1 January 2002 to 31 December 2022, including PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, VIP Database, Wanfang Database and China Biomedical Literature Database. Overall, clinical efficacy rate, bone mineral density and a Visual Analogue Scale score are used as the primary outcome indicators. In addition, the secondary outcome indicator is adverse reactions. The entire screening process will be conducted by two independent investigators; meanwhile, Stata (V.14.0) and RevMan (V.5.4) will be used to conduct the network meta-analysis. If the data are permissible and feasible, we will also perform meta-regression and subgroup analyses to address the underlying causes of data inconsistency and heterogeneity in the statistical analyses. Besides, to improve the credibility of this network meta-analysis, we will evaluate the quality of evidence in this research according to the GRADE assessment.

ETHICS AND DISSEMINATION

Ethics approval is not required for network meta-analyses, which do not involve animals' or people's welfare. The results of this network meta-analysis will be submitted to a recognised journal for publication.

PROSPERO REGISTRATION NUMBER

CRD42023401003.

Role of menopausal hormone therapy in the prevention of postmenopausal osteoporosis

The use of menopausal hormone therapy (MHT) has declined due to concerns about its potential side effects. However, its pivotal role in managing postmenopausal osteoporosis is gaining increased recognition. In this article, we explore how MHT assists postmenopausal women in maintaining bone health and preventing fractures. Recent research indicates that MHT significantly reduces the risk of fractures in women. This benefit is evident regardless of a woman's bone mineral density or their use of progestogens. However, there is limited evidence suggesting that the skeletal benefits continue once the treatment is discontinued. Possible complications of MHT include heart attacks, clots, strokes, dementia, and breast cancer. The most suitable candidates for MHT are women who have recently entered menopause, are experiencing menopausal symptoms, and are below 60 years of age with a minimal baseline risk of adverse events. The treatment is available to those who meet these criteria. For women undergoing premature menopause, MHT can be considered as a means to protect bone health, especially if initiated before menopause or if accelerated bone loss is documented soon after menopause. Such decisions should be made after evaluating individual risk factors and benefits.

Biologics: Teriparatide and Newer Anabolics

The landscape of osteoporosis management has evolved significantly over the years, witnessing a paradigm shift from conventional therapies to the emergence of biologic agents. This chapter delves into the intricate mechanisms, potential applications, and future directions of biologic interventions in osteoporosis care. Biologic agents, with their targeted approach to bone health, have revolutionized the field by offering precision-driven strategies that address the underlying mechanisms of bone fragility. This chapter explores the mechanisms of action of various biologics, including Receptor Activator of Nuclear Factor Kappa-B Ligand (RANKL) inhibitors, monoclonal antibodies targeting sclerostin, parathyroid hormone (PTH) analogues, and cathepsin K inhibitors. It discusses their potential benefits, limitations, and safety considerations, while shedding light on the promise of combination therapies that merge biologic agents with traditional approaches. Furthermore, the chapter delves into the potential applications of biologic agents in specific patient populations, the role of biomarkers in predicting treatment responses, and the influence of emerging biological targets. It also explores the advancements in novel targets and drug delivery systems that aim to enhance treatment convenience and effectiveness. By tailoring treatments based on patient characteristics and exploring novel therapeutic targets, the chapter envisions a future of precision medicine in osteoporosis care. As research continues to evolve, the chapter anticipates a transformative impact on bone health outcomes, fracture prevention, and overall quality of life for individuals at risk of osteoporosis-related fractures. Through comprehensive insights into the mechanisms, applications, and future directions of biologic agents, this chapter offers a holistic perspective on the evolving landscape of osteoporosis management.

Molecular Subtype Classification of Postmenopausal Osteoporosis and Immune Infiltration Microenvironment Based on Bioinformatics Analysis of Osteoclast-Regulatory Genes

Osteoporosis is common in postmenopausal women but is often asymptomatic until a fracture occurs, highlighting the importance of early screening and preventive interventions. This study aimed to develop molecular subtype risk stratification of postmenopausal osteoporosis and analyze the immune infiltration microenvironment. Microarray data for osteoporosis were downloaded and analyzed. Logistic and least absolute shrinkage and selection operator (LASSO) regression analyses were used to construct the molecular risk model. Circulating blood samples were collected from 10 enrolled participants to validate the key differentially expressed genes, and consistent clustering based on the expression profiles of candidate genes was performed to obtain molecular subtypes. Three key genes, CTNNB1, MITF, and TNFSF11, were obtained as variables and used to construct the risk model. External experimental validation showed substantial differences in the three key genes between patients with osteoporosis and the controls (p < 0.05). Three subtypes were obtained based on dimensionality reduction clustering results. Cluster 3 had significantly more patients with low bone mineral density (BMD), whereas Cluster 2 had significantly more patients with high BMD (p < 0.05). This study introduced a novel molecular risk model and subtype classification system, which is an evidence-based screening strategy that will guide the active prevention, early diagnosis, and treatment of osteoporosis in high-risk postmenopausal women.

Curculigoside attenuates osteoporosis through regulating DNMT1 mediated osteoblast activity

This work aims to study the function of curculigoside in osteoporosis and explore whether DNMT1 is closely involved in osteoblast activity. After OB-6 osteoblasts were treated with hydrogen peroxide (H2O2), a curculigoside treatment group was set up and a series of biological tests including MTT, flow cytometry, western blotting, ROS fluorescence intensity, mitochondrial membrane potential, and ELISA experiments were performed to verify the effect of curculigoside on the activity of osteoblasts. Then, alkaline phosphatase (ALP) activity, alizarin red staining, PCR, and western blotting assays were performed to detect the effects of curculigoside on osteoblast function. By constructing DNMT1 knockdown and overexpression OB-6 cell lines, the effect of DNMT1 on osteoblast function was verified. In addition, the expression level of Nrf2 in each group was detected to speculate the mechanism of DNMT1 in osteoporosis. The cell activity and level of bcl-2 and SOD were significantly increased; the cell apoptosis, ROS fluorescence intensity, mitochondrial membrane potential, MDA and level of caspase-3, Bax, and CAT was reduced in curculigoside treatment group compared with H2O2-induced OB-6 osteoblasts. Meanwhile, the ALP activity, number and area of bone mineralized nodules, and gene and protein expression of OSX and OPG were significantly elevated in curculigoside group. Moreover, DNMT1 knockdown had a similar promotion effect on osteoblast function as curculigoside, and DNMT1 overexpression could reverse the promotion effect of curculigoside on osteoblast function. Further mechanistic studies speculated that DNMT1 might play a role in osteoporosis by affecting Nrf2 methylation. Curculigoside enhances osteoblast activity through DNMT1 controls of Nrf2 methylation.

Effects of Teriparatide Treatment on Bone Mineral Density in Patients With Osteoporosis: A Short-Term Dose-Response Study

INTRODUCTION

Osteoporosis is a chronic bone disease that develops with a decrease in bone mineral density (BMD) along with bone mass. An essential measure in the prevention of osteoporosis is the achievement of normal peak bone mass. Teriparatide (TPTD) functions as an osteoanabolic agent, exerting a dual influence on bone remodeling by modulating both osteogenesis and osteoclastogenesis. Bone mass is determined by dual-energy x-ray absorptiometry (DEXA) quantitative CT scan and has outstanding precision (within 1% to 2%) and has the ability to show the effectiveness of drug intervention.

OBJECTIVE

To assess the effectiveness of TPTD treatment on BMD in osteoporosis patients.

MATERIALS AND METHODS

The study is a retrospective, observational, multi-center study of 378 osteoporosis patients who were treated with 20 µg of subcutaneous TPTD every day for six months. DEXA scores of the hip joints of patients were measured both before and after TPTD treatment.

RESULTS

 The DEXA scores of the total population pre and post-treatment were -2.75+0.58 and -2.15+0.95 respectively, with a p-value of <0.001, which is statistically significant. In women the pre and post-treatment scores were -2.728+0.52 and -2.276+0.49, with a significant p-value of <0.001 whereas in males, the scores were -2.756+0.72 and -2.108+1.29 respectively, with a significant p-value of <0.05.

CONCLUSION

The six-month treatment with TPTD significantly improved DEXA scores in osteoporosis patients. DEXA score's precision and sensitivity in quantifying impact contribute to effective osteoporosis management, guiding treatment strategies for better outcomes in the Indian population. Further research is warranted to see the long-term effect of TPTD.

The role of lactoferrin in bone remodeling: evaluation of its potential in targeted delivery and treatment of metabolic bone diseases and orthopedic conditions

Lactoferrin (Lf) is a multifunctional protein that is synthesized endogenously and has various biological roles including immunological regulation, antibacterial, antiviral, and anticancer properties. Recently, research has uncovered Lf's critical functions in bone remodeling, where it regulates the function of osteoblasts, chondrocytes, osteoclasts, and mesenchymal stem cells. The signaling pathways involved in Lf's signaling in osteoblasts include (low density lipoprotein receptor-related protein - 1 (LRP-1), transforming growth factor β (TGF-β), and insulin-like growth factor - 1 (IGF-1), which activate downstream pathways such as ERK, PI3K/Akt, and NF-κB. These pathways collectively stimulate osteoblast proliferation, differentiation, and mineralization while inhibiting osteoclast differentiation and activity. Additionally, Lf's inhibitory effect on nuclear factor kappa B (NF-κB) suppresses the formation and activity of osteoclasts directly. Lf also promotes chondroprogenitor proliferation and differentiation to chondrocytes by activating the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) and phosphoinositide 3-kinase/protein kinase B(PI3K/Akt)signaling pathways while inhibiting the expression of matrix-degrading enzymes through the suppression of the NF-κB pathway. Lf's ability to stimulate osteoblast and chondrocyte activity and inhibit osteoclast function accelerates fracture repair, as demonstrated by its effectiveness in animal models of critical-sized long bone defects. Moreover, studies have indicated that Lf can rescue dysregulated bone remodeling in osteoporotic conditions by stimulating bone formation and suppressing bone resorption. These beneficial effects of Lf on bone health have led to its exploration in nutraceutical and pharmaceutical applications. However, due to the large size of Lf, small bioactive peptides are preferred for pharmaceutical applications. These peptides have been shown to promote bone fracture repair and reverse osteoporosis in animal studies, indicating their potential as therapeutic agents for bone-related diseases. Nonetheless, the active concentration of Lf in serum may not be sufficient at the site requiring bone regeneration, necessitating the development of various delivery strategies to enhance Lf's bioavailability and target its active concentration to the site requiring bone regeneration. This review provides a critical discussion of the issues mentioned above, providing insight into the roles of Lf in bone remodeling and the potential use of Lf as a therapeutic target for bone disorders.

Biofabrication of functional bone tissue: defining tissue-engineered scaffolds from nature

Damage to bone leads to pain and loss of movement in the musculoskeletal system. Although bone can regenerate, sometimes it is damaged beyond its innate capacity. Research interest is increasingly turning to tissue engineering (TE) processes to provide a clinical solution for bone defects. Despite the increasing biomimicry of tissue-engineered scaffolds, significant gaps remain in creating the complex bone substitutes, which include the biochemical and physical conditions required to recapitulate bone cells' natural growth, differentiation and maturation. Combining advanced biomaterials with new additive manufacturing technologies allows the development of 3D tissue, capable of forming cell aggregates and organoids based on natural and stimulated cues. Here, we provide an overview of the structure and mechanical properties of natural bone, the role of bone cells, the remodelling process, cytokines and signalling pathways, causes of bone defects and typical treatments and new TE strategies. We highlight processes of selecting biomaterials, cells and growth factors. Finally, we discuss innovative tissue-engineered models that have physiological and anatomical relevance for cancer treatments, injectable stimuli gels, and other therapeutic drug delivery systems. We also review current challenges and prospects of bone TE. Overall, this review serves as guide to understand and develop better tissue-engineered bone designs.

Psoralen prevents the inactivation of estradiol and treats osteoporosis via covalently targeting HSD17B2

ETHNOPHARMACOLOGICAL RELEVANCE

Psoralea corylifolia L. seeds (P. corylifolia), popularly known as Buguzhi in traditional Chinese medicine, are often used to treat osteoporosis in China. Psoralen (Pso) is the key anti-osteoporosis constituent in P. corylifolia, however, its targets and mechanism of action are still unclear.

AIM OF THE STUDY

The purpose of this study was to explore the interaction between Pso and 17-β hydroxysteroid dehydrogenase type 2 (HSD17B2), an estrogen synthesis-related protein that inhibits the inactivation of estradiol (E2) to treat osteoporosis.

MATERIALS AND METHODS

Tissue distribution of Pso was analyzed by in-gel imaging after oral administration of an alkynyl-modified Pso probe (aPso) in mice. The target of Pso in the liver was identified and analyzed using chemical proteomics. Co-localization and cellular thermal shift assays (CETSA) were used to verify the key action targets. To detect the key pharmacophore of Pso, the interaction of Pso and its structural analogs with HSD17B2 was investigated by CETSA, HSD17B2 activity assay, and in-gel imaging determination. Target competitive test, virtual docking, mutated HSD17B2 activity, and CETSA assay were used to identify the binding site of Pso with HSD17B2. A mouse model of osteoporosis was established by ovariectomies, and the efficacy of Pso in vivo was confirmed by micro-CT, H&E staining, HSD17B2 activity, and bone-related biochemical assays.

RESULTS

Pso regulated estrogen metabolism by targeting HSD17B2 in the liver, with the α, β-unsaturated ester in Pso being the key pharmacophore. Pso significantly suppressed HSD17B2 activity by irreversibly binding to Lys236 of HSD17B2 and preventing NAD⁺ from entering the binding pocket. In vivo studies in ovariectomized mice revealed that Pso could inhibit HSD17B2 activity, prevent the inactivation of E2, increase levels of endogenous estrogen, improve bone metabolism-related indices, and play a role in anti-osteoporosis.

CONCLUSIONS

Pso covalently binds to Lys236 of HSD17B2 in hepatocytes to prevent the inactivation of E2, thereby aiding in the treatment of osteoporosis.

Transcriptomic analysis the mechanisms of anti-osteoporosis of desert-living Cistanche herb in ovariectomized rats of postmenopausal osteoporosis

Desert-living Cistanche herb (DC), as a traditional Chinese medicine for tonifying kidney yang, is often used to treat postmenopausal osteoporosis (PMOP). Total phenylethanoid glycosides are instruction ingredients for discrimination and assay according to the China pharmacopoeia for DC. This research aimed to reveal the anti-osteoporosis mechanism of total phenylethanoid glycosides of DC (PGC) by transcriptomic analysis of ovariectomized rats. Serum levels of BGP were evaluated by ELISA, the bone weight was measured, and transmission electron microscopy was used to examine the ultrastructure of osteoblasts in rats. In addition, micro-CT was used to detect the bone volume (Tb.BS/BV), bone mineral density (Tb.BMD), and bone mineral content (Tb.BMC) in trabecular bone, and the ratio of cortical bone area to total area (Ct.ar/Tt.ar), and the level of bone mineral content (Ct.BMC) in cortical bone. Differential expressed genes (DEGs) after PGC treatment were analyzed by transcriptomics. Then, a bioinformatics analysis of DEGs was carried out through GO enrichment, KEGG enrichment, and selection of the nucleus gene through the protein-protein interaction network. Through qRT-PCR analysis, the DEGs were verified. The analysis results indicated that PGC increased the secretion of osteogenic markers, and ultrastructural characterization of osteoblasts and bone morphology were improved in ovariectomized rats. A total of 269 genes were differentially expressed, including 201 genes that were downregulated and 68 genes that were upregulated between the model group and the PGC group. Bioinformation analysis results prompt the conclusion that PGC could promote the bone metabolism by muscle cell development, myofibril assembly, etc. In addition, our study also found that PGC has a good effect on osteoporosis complicated with cardiomyopathy, and it also provided evidence for the correlation between sarcopenia and osteoporosis.

Angiogenesis coupled with osteogenesis in a bone tissue engineering scaffold enhances bone repair in osteoporotic bone defects

Increased life expectancy has resulted in an increase in osteoporosis incidence worldwide. The coupling of angiogenesis and osteogenesis is indispensable for bone repair. Although traditional Chinese medicine (TCM) exerts therapeutic effects on osteoporosis, TCM-related scaffolds, which focus on the coupling of angiogenesis and osteogenesis, have not yet been used for the treatment of osteoporotic bone defects.Panax notoginsengsaponin (PNS), the active ingredient ofPanax notoginseng, was added to a poly (_L-lactic acid) (PLLA) matrix. Osteopractic total flavone (OTF), the active ingredient ofRhizoma Drynariae, was encapsulated in nano-hydroxyapatite/collagen (nHAC) and added to the PLLA matrix. Magnesium (Mg) particles were added to the PLLA matrix to overcome the bioinert character of PLLA and neutralize the acidic byproducts generated by PLLA. In this OTF-PNS/nHAC/Mg/PLLA scaffold, PNS was released faster than OTF. The control group had an empty bone tunnel; scaffolds containing OTF:PNS = 100:0, 50:50, and 0:100 were used as the treatment groups. Scaffold groups promoted new vessel and bone formation, increased the osteoid tissue, and suppressed the osteoclast activity around osteoporotic bone defects. Scaffold groups upregulated the expression levels of angiogenic and osteogenic proteins. Among these scaffolds, the OTF-PNS (50:50) scaffold exhibited a better capacity for osteogenesis than the OTF-PNS (100:0 and 0:100) scaffolds. Activation of the bone morphogenic protein (BMP)-2/BMP receptor (BMPR)-1A/runt-related transcription factor (RUNX)-2signaling pathway may be a possible mechanism for the promotion of osteogenesis. Our study demonstrated that the OTF-PNS/nHAC/Mg/PLLA scaffold could promote osteogenesis via the coupling of angiogenesis and osteogenesis in osteoporotic rats with bone defects, and activating theBMP-2/BMPR1A/RUNX2signaling pathway may be an osteogenesis-related mechanism. However, further experiments are necessary to facilitate its practical application in the treatment of osteoporotic bone defects.

Comparative Pharmacokinetic Study of 5 Active Ingredients after Oral Administration of Zuogui Pill in Osteoporotic Rats with Different Syndrome Types

Zuogui Pill is a kidney-yin-tonifying formula in traditional Chinese medicine that is widely used to manage osteoporosis with kidney-yin-deficiency in China. Herein, an efficient and accurate high-performance liquid chromatography-tandem mass spectrometry method was developed to determine the concentrations of 5 bioactive compounds in rat plasma following oral administration of Zuogui Pill. Because drug absorption and distribution differ under physiological and pathological conditions, the established method was used to quantify blood components and dynamic change in osteoporotic rats with different syndrome types. Moreover, integrated pharmacokinetic study was conducted to describe the overall pharmacokinetic characteristics of traditional Chinese medicine. The results showed that the absorption, distribution, and metabolism of Zuogui Pill varied widely under different states. The bioavailability of most active components showed significant advantages in osteoporotic rats with kidney-yin-deficiency, which corresponds to the opinion that Zuogui Pill has the effect of nourishing kidney-yin. It is hoped that this finding could interpret the pharmacodynamic substances and mechanism of Zuogui Pill in the treatment of osteoporosis with kidney-yin-deficiency.

Quercetin protects against iron overload-induced osteoporosis through activating the Nrf2/HO-1 pathway

AIMS

Eucommia is the tree bark of Eucommia japonica, family Eucommiaceae. In traditional Chinese medicine, Eucommia is often used to treat osteoporosis. Quercetin (QUE), a major flavonoid extract of Eucommia japonica, has been reported to have anti-osteoporosis effects. However, there are no studies reporting the mechanism of QUE in the treatment of iron overload-induced osteoporosis. This study set out to investigate the therapeutic effects of QUE against iron overload-induced bone loss and its potential molecular mechanisms.

MATERIALS AND METHODS

In vitro, MC3T3-E1 cells were used to study the effects of QUE on osteogenic differentiation, anti-apoptosis and anti-oxidative stress damage in an iron overload environment (FAC 200 μM). In vivo, we constructed an iron overload mouse model by injecting iron dextrose intraperitoneally and assessed the osteoprotective effects of QUE by Micro-CT and histological analysis.

KEY FINDINGS

In vitro, we found that QUE increased the ALP activity of MC3T3-E1 cells in iron overload environment, promoted the formation of bone mineralized nodules and upregulated the expression of Runx2 and Osterix. In addition, QUE was able to reduce FAC-induced apoptosis and ROS production, down-regulated the expression of Caspase3 and Bax, and up-regulated the expression of Bcl-2. In further studies, we found that QUE activated the Nrf2/HO-1 signaling pathway and attenuated FAC-induced oxidative stress damage. The results of the in vivo study showed that QUE was able to reduce iron deposition induced by iron dextrose and attenuate bone loss.

SIGNIFICANCE

Our results suggested that QUE protects against iron overload-induced osteoporosis by activating the Nrf2/HO-1 signaling pathway.

The role and regulation mechanism of Chinese traditional fitness exercises on the bone and cartilage tissue in patients with osteoporosis: A narrative review

Osteoporosis (ops) is a systemic degenerative bone disease characterized by bone mass reduction, bone mineral density loss, bone microstructure destruction, bone fragility, and increased fracture susceptibility. Thus far, drug therapy is the main method used to prevent and treat osteoporosis. However, long-term drug treatment will inevitably lead to drug resistance and certain side effects. In response, rehabilitation treatment is generally recommended, which involves drug supplementation combined with the treatment. A Chinese traditional fitness exercise is an organic combination of sports and traditional Chinese medicine with a series of advantages such as being safe, convenient, non-toxic, and harmless. Hence, it is one of the rehabilitation methods widely used in clinical practice. By searching the CNKI, PubMed, Web of Science, Embase, Cochrane Library, and other relevant databases, our research clarifies the current situation of four kinds of Chinese traditional fitness exercises widely used in clinical practice, namely, Taijiquan, Baduanjin, Wuqinxi, and Yijin Jing. In addition, the molecular mechanism of osteoporosis is summarized in this study. Based on the research, Chinese traditional fitness exercises are expected to directly stimulate the bone through a mechanical load to improve bone density. Moderate and regular traditional Chinese fitness exercises also improve osteoporosis by regulating the endocrine system with the secretion of hormones and factors such as estrogen and irisin, which are beneficial for bone formation. Finally, the purpose of promoting bone formation, reducing bone loss, and preventing and treating osteoporosis is achieved. The various means of Chinese traditional fitness exercises have different emphases, and the effect of improving bone density differs in various parts of the body. The exercisers may choose the exercise flexibly based on their own needs. Chinese traditional fitness exercises can improve the bone density of the exercisers and relieve pain, improve balance, and regulate the psychological state. Consequently, it is worth promoting to be applied in clinical practices.

Electroactive Biomaterials for Facilitating Bone Defect Repair under Pathological Conditions

Bone degeneration associated with various diseases is increasing due to rapid aging, sedentary lifestyles, and unhealthy diets. Living bone tissue has bioelectric properties critical to bone remodeling, and bone degeneration under various pathological conditions results in significant changes to these bioelectric properties. There is growing interest in utilizing biomimetic electroactive biomaterials that recapitulate the natural electrophysiological microenvironment of healthy bone tissue to promote bone repair. This review first summarizes the etiology of degenerative bone conditions associated with various diseases such as type II diabetes, osteoporosis, periodontitis, osteoarthritis, rheumatoid arthritis, osteomyelitis, and metastatic osteolysis. Next, the diverse array of natural and synthetic electroactive biomaterials with therapeutic potential are discussed. Putative mechanistic pathways by which electroactive biomaterials can mitigate bone degeneration are critically examined, including the enhancement of osteogenesis and angiogenesis, suppression of inflammation and osteoclastogenesis, as well as their anti-bacterial effects. Finally, the limited research on utilization of electroactive biomaterials in the treatment of bone degeneration associated with the aforementioned diseases are examined. Previous studies have mostly focused on using electroactive biomaterials to treat bone traumatic injuries. It is hoped that this review will encourage more research efforts on the use of electroactive biomaterials for treating degenerative bone conditions.

Asperosaponin VI induces osteogenic differentiation of human umbilical cord mesenchymal stem cells via the estrogen signaling pathway

BACKGROUND

Asperosaponin VI (ASA VI) is an active ingredient found in the traditional Chinese herb Radix Dipsaci, which is used to treat fractures. ASA VI combined with osteogenic medium can induce osteogenic differentiation of rat-derived stem cells. However, whether ASA VI alone can induce osteoblast differentiation of human mesenchymal stem cells (MSCs) remains unclear.

METHODS

ASA VI human-derived binding proteins were searched in the PharmMapper database, osteogenesis-related signaling pathways were obtained through a literature search, and proteins contained in these signaling pathways were queried in the Kyoto Encyclopedia of Genes and Genomes database. SystemsDock was used to perform online molecular docking of target proteins to evaluate their binding abilities, and validation experiments were performed.

RESULTS

A total of 620 ASA VI target proteins and 12 osteogenesis-related signaling pathways were queried, and 17 intersecting targets were screened. Molecular docking results showed that these targets had high binding affinity for ASA VI. We selected estrogen receptor 2 and its estrogen signaling pathway for experimental validation. The results showed that ASA VI can induce the osteogenic differentiation of MSCs through the estrogen signaling pathway.

CONCLUSION

ASA VI can independently induce osteogenic differentiation of human umbilical cord MSCs, and the estrogen signaling pathway plays an important role in this process. Thus, ASA VI may have potential as an anti-osteoporosis drug.

Menopausal hormone therapy reduces the risk of fracture regardless of falls risk or baseline FRAX probability-results from the Women's Health Initiative hormone therapy trials

In a combined analysis of 25,389 postmenopausal women aged 50-79 years, enrolled in the two Women's Health Initiative hormone therapy trials, menopausal hormone therapy vs. placebo reduced the risk of fracture regardless of baseline FRAX fracture probability and falls history.

INTRODUCTION

The aim of this study was to determine if the anti-fracture efficacy of menopausal hormone therapy (MHT) differed by baseline falls history or fracture risk probability as estimated by FRAX, in a combined analysis of the two Women's Health Initiative (WHI) hormone therapy trials.

METHODS

A total of 25,389 postmenopausal women aged 50-79 years were randomized to receive MHT (n = 12,739) or matching placebo (n = 12,650). At baseline, questionnaires were used to collect information on falls history, within the last 12 months, and clinical risk factors. FRAX 10-year probability of major osteoporotic fracture (MOF) was calculated without BMD. Incident clinical fractures were verified using medical records. An extension of Poisson regression was used to investigate the relationship between treatment and fractures in (1) the whole cohort; (2) those with prior falls; and (3) those without prior falls. The effect of baseline FRAX probability on efficacy was investigated in the whole cohort.

RESULTS

Over 4.3 ± 2.1 years (mean ± SD), MHT (vs. placebo) significantly reduced the risk of any clinical fracture (hazard ratio [HR] 0.72 [95% CI, 0.65-0.78]), MOF (HR 0.60 [95% CI, 0.53-0.69]), and hip fracture (0.66 [95% CI, 0.45-0.96]). Treatment was effective in reducing the risk of any clinical fracture, MOF, and hip fracture in women regardless of baseline FRAX MOF probability, with no evidence of an interaction between MHT and FRAX (p > 0.30). Similarly, there was no interaction (p > 0.30) between MHT and prior falls.

CONCLUSION

In the combined WHI trials, compared to placebo, MHT reduces fracture risk regardless of FRAX probability and falls history in postmenopausal women.

Lactic Acid Bacteria: A Promising Tool for Menopausal Health Management in Women

Menopause is a period during which women undergo dramatic hormonal changes. These changes lead to physical and mental discomfort, are greatly afflictive, and critically affect women's lives. However, the current safe and effective management measures for women undergoing menopause are insufficient. Several probiotic functions of lactic acid bacteria (LAB) have been recognized, including alleviation of lactose intolerance, protection of digestive tract health, activation of the immune system, protection against infections, improvement of nutrient uptake, and improvement of the microbiota. In this review, we highlight the currently available knowledge of the potential protective effects of LAB on preventing or mitigating menopausal symptoms, particularly in terms of maintaining balance in the vaginal microbiota, reducing bone loss, and regulating the nervous system and lipid metabolism. Given the increasing number of women entering menopause and the emphasis on the management of menopausal symptoms, LAB are likely to soon become an indispensable part of clinical/daily care for menopausal women. Herein, we do not intend to provide a comprehensive analysis of each menopausal disorder or to specifically judge the reliability and safety of complementary therapies; rather, we aim to highlight the potential roles of LAB in individualized treatment strategies for the clinical management of menopause.

Increased Risk of Fractures and Use of Proton Pump Inhibitors in Menopausal Women: A Systematic Review and Meta-Analysis

Proton pump inhibitors (PPIs) can directly interfere with osteoclastic function, induce hypergastrinemia, and inhibit calcium absorption, leading to reduced bone mineral density (BMD), a measure of bone metabolism that may be associated with the risk of fractures. The current study involves a systematic review and meta-analysis aimed at assessing the relationship between prolonged use of PPI drugs and fractures in menopausal women. A systematic search and meta-analysis were performed on PubMed, Scopus, and Science Direct databases according to PRISMA guidelines. Two independent reviewers analyzed the articles. The five articles found in the databases, which met the eligibility criteria, covered participants who were menopausal women aged between 56 and 78.5 years, using or not using a PPI for a minimum of 12 months. All studies showed an increase in the rate of fractures related to using PPIs, as an outcome. Prolonged use of PPIs in menopausal women can affect bone metabolism and cause fractures. However, other factors, such as the use of other classes of drugs, obesity, low weight, poor diet, replacement hormones, and comorbidities, should also be considered for assessing the risk of fractures.

Association of ESR1 and ESR2 Polymorphisms with Osteoporosis: A Meta-Analysis from 36 Studies

BACKGROUND

Recently, the roles of ESR1 and ESR2 polymorphisms in osteoporosis have been extensively reported, with conflicting findings. Therefore, we performed this present study to evaluate the potential associations between ESR1 and ESR2 polymorphisms and osteoporosis risk.

METHODOLOGY

All included literatures published up to April 2021 were identified by searching Pubmed, Embase, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI) and Wanfang databases. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated the associations using a fixed or random effects model.

RESULTS

36 observational studies involving five gene polymorphisms (ESR1 PvuII, ESR1 XbaI, ESR1 G2014A, ESR2 AluI and ESR2 RsaI) covering 12507 cases and 18487 controls were included. The results of our meta-analysis demonstrated the variant A allele of ESR2 RsaI polymorphism might play a remarkable protective role in developing osteoporosis under all genetic models. However, no associations were observed between ESR1 PvuII, ESR1 XbaI, ESR1 G2014A and ESR2 AluI polymorphisms with the risk of osteoporosis under all genetic models.

CONCLUSIONS

Our meta-analysis suggests that genetic polymorphism in ESR2 RsaI may lead to decreased risk for osteoporosis. Further larger studies are needed to confirm this conclusion.

Traditional Chinese decoction Si Zhi Wan attenuates ovariectomy (OVX)-induced bone loss by inhibiting osteoclastogenesis and promoting apoptosis of mature osteoclasts

Si Zhi Wan (SZW) is a traditional Chinese decoction used for osteoporosis treatment. Currently, the effect of SZW on ovariectomy (OVX)-induced bone loss and the underlying mechanisms remain unknown. Herein, we investigated the therapeutic effect of SZW on osteoporosis and explored the underlying mechanisms in vitro and in vivo. An OVX-induced bone loss model was established in vivo. After administration of SZW for 8 weeks, rats were sacrificed, and the uterus was weighted to calculate its index. The femur change was pathologically evaluated using hematoxylin and eosin (H&E) staining. The mineral density of the femur was observed by micro-CT. RAW264.7 cells were activated by receptor activator of nuclear factor-κB ligand (RANKL) in vitro. The effect of SZW on osteoclastogenesis was evaluated using tartrate-resistant acid phosphatase (TRAP) staining, Western blotting, and RT-PCR. The pro-apoptosis effect of SZW on mature osteoclasts was examined after induction of osteoclast maturation. Finally, the effect of SZW on the NF-κB pathway was evaluated. Our results demonstrated that SZW ameliorated OVX-induced bone loss in rats. In addition, SZW inhibited osteoclastogenesis and attenuated osteoclast-mediated bone resorption in vitro and in vivo. SZW also promoted apoptosis of mature osteoclasts. Mechanically, SZW exerts its effects by suppressing the NF-κB pathway. Overall, these findings demonstrated that SZW may be a potentially effective alternative treatment for osteoporosis.

Biomaterials and advanced technologies for the evaluation and treatment of ovarian aging

Ovarian aging is characterized by a progressive decline in ovarian function. With the increase in life expectancy worldwide, ovarian aging has gradually become a key health problem among women. Over the years, various strategies have been developed to preserve fertility in women, while there are currently no clinical treatments to delay ovarian aging. Recently, advances in biomaterials and technologies, such as three-dimensional (3D) printing and microfluidics for the encapsulation of follicles and nanoparticles as delivery systems for drugs, have shown potential to be translational strategies for ovarian aging. This review introduces the research progress on the mechanisms underlying ovarian aging, and summarizes the current state of biomaterials in the evaluation and treatment of ovarian aging, including safety, potential applications, future directions and difficulties in translation.

Management of postmenopausal women: Collège National des Gynécologues et Obstétriciens Français (CNGOF) and Groupe d'Etude sur la Ménopause et le Vieillissement (GEMVi) Clinical Practice Guidelines

AIM

The aim of these recommendations is to set forth an individualized approach to the management of early postmenopausal women (i.e., within the first 10 years after natural menopause) covering all aspects of lifestyle and therapeutic management, with or without menopause hormone therapy (MHT).

MATERIALS AND METHODS

Literature review and consensus of French expert opinion. Recommendations were graded according to the HAS methodology and levels of evidence derived from the international literature, except when there was no good-quality evidence.

SUMMARY RECOMMENDATIONS

The beginning of menopause is an ideal time for each woman to evaluate her health status by assessing her bone, cardiovascular, and cancer-related risk factors that may be amplified by postmenopausal estrogen deficiency and by reviewing her lifestyle habits. Improving lifestyle, including nutrition and physical activity, and avoiding risk factors (notably smoking), should be recommended to all women. MHT remains the most effective treatment for vasomotor symptoms but it could be also recommended as first-line treatment for the prevention of osteoporosis in early postmenopausal women at low to moderate risk for fracture. The risks of MHT differ depending on its type, dose, duration of use, route of administration, timing of initiation, and whether a progestogen is used. There is reasonable evidence that using transdermal estradiol in association with micronized progesterone or dydrogesterone may limit both the venous thromboembolic risk associated with oral estrogens and the risk of breast cancer associated with synthetic progestins. Treatment should be individualized to each woman, by using the best available evidence to maximize benefits and minimize risks, with periodic reevaluation of its benefit-risk balance. For bothersome genitourinary syndrome of menopause (GSM) symptoms, vaginal treatment with lubricants and moisturizers is recommended as first-line treatment together with low-dose vaginal estrogen therapy, depending on the clinical course. No recommendation of an optimal duration of MHT can be made, but it must take into consideration the initial indication for MHT as well as each woman's benefit-risk balance. Management of gynecological side-effects of MHT is also examined. These recommendations are endorsed by the Groupe d'Etude sur la Ménopause et le Vieillissement hormonal (GEMVI) and the Collège National des Gynécologues-Obstétriciens Français (CNGOF).

Relationship between Bone Mineral Density and Dental Caries in Koreans by Sex and Menopausal State

We aimed to investigate the relationship between bone mineral density and dental caries in adults of over 19 years of age who were categorized according to their sex and menopausal status. The Korea National Health and Nutrition Examination Survey (KNHANES) dataset was used for the study. Bone mineral density (BMD) and oral health examination data were collected between 2008 and 2011. A total of 17,141 adults of ≥19 years old were eligible for inclusion in the present study. Multiple regression analysis was performed after adjustment for age, household income, educational level, smoking status, and alcohol drinking status for men, and pre- and post-menopausal women. In men, the β-value for the mean decayed, missing, and filled teeth (DMFT) index was 0.98 (95% confidence interval (CI) = 0.71−1.25), and was significantly higher in osteoporotic participants than in participants with normal BMD (p < 0.05). In post-menopausal women, the β-value for the mean DMFT index was 0.86, and was higher in the osteoporotic participants than in the participants with normal BMD (p < 0.05). Men and post-menopausal women with osteoporosis had higher DMFT indexes than those with normal BMD. In addition, there was a correlation between DMFT index and BMD in men and post-menopausal women. Therefore, the prevention of osteoporosis should be implemented alongside proper oral care.

Estradiol deficiency reduces the satellite cell pool by impairing cell cycle progression

The size of the satellite cell pool is reduced in estradiol (E2)-deficient female mice and humans. Here, we use a combination of in vivo and in vitro approaches to identify mechanisms, whereby E2 deficiency impairs satellite cell maintenance. By measuring satellite cell numbers in mice at several early time points postovariectomy (Ovx), we determine that satellite cell numbers decline by 33% between 10 and 14 days post-Ovx in tibialis anterior and gastrocnemius muscles. At 14 days post-Ovx, we demonstrate that satellite cells have a reduced propensity to transition from G0/G1 to S and G2/M phases, compared with cells from ovary-intact mice, associated with changes in two key satellite cell cycle regulators, ccna2 and p16INK4a. Further, freshly isolated satellite cells treated with E2 in vitro have 62% greater cell proliferation and require less time to complete the first division. Using clonal and differentiation assays, we measured 69% larger satellite cell colonies and enhanced satellite cell-derived myoblast differentiation with E2 treatment compared with vehicle-treated cells. Together, these results identify a novel mechanism for preservation of the satellite cell pool by E2 via promotion of satellite cell cycling.

Three Classes of Antioxidant Defense Systems and the Development of Postmenopausal Osteoporosis

Osteoporosis is a common bone imbalance disease that threatens the health of postmenopausal women. Estrogen deficiency accelerates the aging of women. Oxidative stress damage is regarded as the main pathogenesis of postmenopausal osteoporosis. The accumulation of reactive oxygen species in the bone microenvironment plays a role in osteoblast and osteoclast apoptosis. Improving the oxidative state is essential for the prevention and treatment of postmenopausal osteoporosis. There are three classes of antioxidant defense systems in the body to eliminate free radicals and peroxides including antioxidant substances, antioxidant enzymes, and repair enzymes. In our review, we demonstrated the mechanism of antioxidants and their effect on bone metabolism in detail. We concluded that glutathione/oxidized glutathione (GSH/GSSG) conversion involved the PI3K/Akt-Nrf2/HO-1 signaling pathway and that the antioxidant enzyme-mediated mitochondrial apoptosis pathway of osteoblasts was necessary for the development of postmenopausal osteoporosis. Since the current therapeutic effects of targeting bone cells are not significant, improving the systemic peroxidation state and then regulating bone homeostasis will be a new method for the treatment of postmenopausal osteoporosis.

Relationship between indices of circulating blood cells and bone homeostasis in osteoporosis

Bone development have been shown to play an important role in regulating hematopoiesis as one major component of bone marrow microenvironment. Recent studies support the notion that there is an intricate relationship between hematopoiesis and bone homeostasis, however, little is known about the alterations in the hematopoietic lineages in pathologic conditions. Using various osteoporotic mouse models, we show here that bone microarchitecture abnormalities alter parameters of peripheral blood cells. The level of white blood cells is dynamics and negatively correlated with bone mineral density during the progression of osteoporosis. Furthermore, our clinical data confirm that osteoporosis is associated with abnormal circulating blood cell counts. These results demonstrated a causal link that osteoporosis is accompanied by the altered circulating blood cells, supporting the idea of a close interplay between hematopoiesis and bone homeostasis. Our study would propose that routine complete blood count might be applied as a potential diagnostic and putative marker for osteoporosis.

Overall adjustment acupuncture improves osteoporosis and exerts an endocrine-modulating effect in ovariectomized rats

BACKGROUND

Acupuncture is a widely practiced, convenient, and safe treatment modality within complementary and integrative medicine. Increasing studies have revealed the efficacy of acupuncture for the treatment of osteoporosis in both human and non-human subjects. The aim of the present study was to assess the improvement of osteoporosis after overall adjustment acupuncture (OA) as well as its endocrine-modulating effect in an ovariectomized rat model.

METHODS

In total, 32 female Sprague-Dawley (SD) rats were randomly divided into the sham, model, ovariectomy+estrogen (OVX+E), and OVX+OA (OVX+A) groups with eight rats in each group. The postmenopausal osteoporosis (PMOP) rat model was induced by bilateral ovariectomy. At 12 weeks after surgery, rats in the OVX+E group received estradiol (0.2 mg/kg/i.g./qod) for 12 weeks, and rats in the OVX+A group were treated with acupuncture at Zusanli (ST36), Shenshu (BL23), and Dazhu (BL11) points (qod) for 12 weeks. At the end of the treatment, all rats were sacrificed, and the body weight, uterus index, bone mineral density (BMD), bone mineral content (BMC), bone trabeculae structural parameters, femoral biomechanical properties, femoral histomorphology, and several hormone levels were examined.

RESULTS

In OVX rats, OA abrogated the body weight gain and improved osteoporosis in terms of BMD, BMC, bone trabeculae structural parameters, bone strength, and bone tissue histomorphology. Moreover, OA modulated the serum levels of estradiol, corticotropin releasing hormone (CRH), adrenocorticotropic hormone (ACTH), and corticosterone (CORT).

CONCLUSIONS

OA improves osteoporosis and exerts an endocrine-modulating effect in ovariectomized rats.

Emerging roles of circular RNAs in osteoporosis

Osteoporosis is one bone disease characterized with skeletal impairment, bone strength reduced and fracture risk enhanced. The regulation processes of bone metabolism are associated with several factors such as mechanical stimulation, epigenetic regulation and hormones. However, the mechanism of osteoporosis remains unsatisfactory. Increasing high‐throughput RNA sequencing and circular RNAs (circRNAs) microarray studies indicated that circRNAs are differentially expressed in osteoporosis. Growing functional studies further pinpointed specific deregulated expressed circRNAs (e.g., circ_28313, circ_0016624, circ_0006393, circ_0076906 and circ_0048211) for their functions involved in bone metabolism, including bone marrow stromal cells (BMSCs) differentiation, proliferation and apoptosis. Moreover, CircRNAs (circ_0002060, Circ_0001275 and Circ_0001445) may be acted as diagnostic biomarkers for osteoporosis. This review discussed recent progresses in the circRNAs expression profiling analyses and their potential functions in regulating BMSCs differentiation, proliferation and apoptosis.

Identifying a possible new target for diagnosis and treatment of postmenopausal osteoporosis through bioinformatics and clinical sample analysis

Background

Postmenopausal osteoporosis, a common yet chronic systemic metabolic disease, has become a major public health problem due to life expectancy increasing around the world. The differentiation of mesenchymal stem cells (MSCs) into osteoblasts, and the differentiation of circulating monocyte cells into osteoclasts, play an important role in the balance of bone metabolism. However, when both undergo pathological changes, it can lead to abnormalities, resulting in osteoporosis. This study aims to explore a new biomarker for postmenopausal osteoporosis, thereby providing a new entry point for bioinformatic research into the clinical diagnosis and treatment of the disease.

Methods

Using the Gene Expression Omnibus (GEO) database, microarray analysis was conducted to identify differentially expressed genes in MSCs and monocytes in both postmenopausal osteoporosis patients and a healthy control group. The Database for Annotation, Visualization and Integrated Discovery (DAVID) database was used to analyze the function and enrichment of the selected genes, and a protein-protein interaction (PPI) network was constructed from the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) website and displayed in Cytoscape. To achieve the final results, module analysis of the PPI network was performed by using Molecular Complex Detection (MCODE).

Results

We identified 45 high-expression and 26 low-expression genes through the study, all of which underwent pathway enrichment analysis. This enrichment was observed in the cell cycle regulation, osteoclast differentiation, tumor necrosis factor (TNF) signaling pathway, and RNA transport. The top 10 hub genes of the PPI network were SF3B1, SRSF5, FUBP1, SRSF3, TIA1, KHSRP, LUC7L3, PNN, SRC, and ATRX. Comparing the MSCs and monocytes between the postmenopausal osteoporosis patients and the healthy control group, we noted that the expression of the above genes differed greatly.

Conclusions

Through bioinformatic analysis and clinical specimen validation, our study provides a new way for exploring the pathogenesis of postmenopausal osteoporosis. Most importantly, it suggests that the hub genes, SF3B1, SRSF5, FUBP1, KHSRP, and SRC, may become new diagnostic markers and therapeutic targets for diagnosing and treating postmenopausal osteoporosis in the future.

The role of estrogens in osteosarcopenia: from biology to potential dual therapeutic effects

Osteoporosis and sarcopenia are two conditions associated with aging and characterized by a simultaneous decline in bone and muscle mass, respectively. These conditions share common risk factors (genetic, endocrine, nutritional and lifestyle factors) and biological pathways that often co-exist in a syndrome known as osteosarcopenia. Among the endocrine causes, estrogens play a critical role, especially in women. Estrogens have been demonstrated to exert a positive effect on bone and muscle development and maintenance. For this reason, menopause is characterized by a loss in bone mineral density and skeletal muscle quality and quantity. To date, studies indicate a positive effect of hormonal therapy on the prevention and management of osteoporosis, to the point that estrogen is prescribed as a first-line treatment for osteoporosis by the major international authorities. While results on sarcopenia are still disputable, such that estrogens are not recommended to prevent muscle loss in postmenopausal women, increased response to anabolic stimuli with estrogen therapy suggests similar beneficial effects on muscle as seen with bone, particularly when combined with resistance exercise.

Higher Dietary Se Intake Is Associated With the Risk of New-Onset Fracture: A National Longitudinal Study for 20 Years

Background: The association between dietary selenium (Se) intake and osteoporosis-related fractures remains inconsistent. We aimed to examine the dose relationship between Se intake and incident fracture among Chinese adults. Methods: The dietary data were retrieved from the China Health and Nutrition Survey conducted between 1991 and 2011, and 17,150 participants aged above 20 were included. A 3-day, 24-h recall of food intake was performed to assess cumulative average dietary Se intake. The fracture was based on self-report in each survey between 1997 and 2011. The association between Se intake and fracture was tested by Cox regression, and the non-linear association was examined by restricted cubic splines (RCS). Results: There were 976 fracture cases during a mean of 10.2 years follow-up. In a fully adjusted Cox model, across the quartiles of Se intake, the hazard ratios (HRs) for fracture were 1.07 (95% CI .86-1.33), 1 (reference), 1.25 (95% CI 1.02-1.53), and 1.33 (95% CI 1.07-1.65). RCS showed a parabolic association (P non-linear = 0.037) between Se and fracture for men as well as a U-shape dose-response (P non-linear = 0.04) between Se and fracture for subjects living in highly urbanized areas. Conclusion: In conclusion, there is a non-linear association between selenium intake and fracture, with higher intake associated with increased risk. The shape of the association varies by gender and urbanization level.

COVID-19 and endocrine and metabolic disorders: critical points and suggestions for a correct therapeutic management from a tertiary endocrine center in Italy

The Coronavirus-19 (COVID-19) pandemic, which began in December 2019 in Wuhan, China, has spread rapidly worldwide, affecting mostly frail individuals and resulting in high lethality among people with chronic conditions. The management of chronic endocrine disorders during the pandemic period proved particularly challenging, as they require close physician-patient contact for proper long-term management. In addition, acute endocrinologic conditions that presented during the COVID-19 period required timely management in an unusual clinical setting, providing an ongoing challenge for clinicians. This article summarizes the most recent guidance on the management and therapy of frequent conditions such as diabetes and osteoporosis and less common endocrine disorders (e.g., adrenal insufficiency) in this setting.