Olink Proteomics for the Identification of Biomarkers for Early Diagnosis of Postmenopausal Osteoporosis.

This investigation aims to employ Olink proteomics in analyzing the distinct serum proteins associated with postmenopausal osteoporosis (PMOP) and identifying prognostic markers for early detection of PMOP via molecular mechanism research on postmenopausal osteoporosis. Postmenopausal women admitted to Beijing Jishuitan Hospital were randomly selected and categorized into three groups based on their dual-energy X-ray absorptiometry (DXA) T-scores: osteoporosis group (n = 24), osteopenia group (n = 20), and normal bone mass group (n = 16). Serum samples from all participants were collected for clinical and bone metabolism marker measurements. Olink proteomics was utilized to identify differentially expressed proteins (DEPs) that are highly associated with postmenopausal osteoporosis. The functional analysis of DEPs was performed using Gene Ontology and Kyto Encyclopedia Genes and Genomes (KEGG). The biological characteristics of these proteins and their correlation with PMOP were subsequently analyzed. ROC curve analysis was performed to identify potential biomarkers with the highest diagnostic accuracy for early stage PMOP. Through Olink proteomics, we identified five DEPs highly associated with PMOP, including two upregulated and three downregulated proteins. TWEAK and CDCP1 markers exhibited the highest area under the curve (0.8188 and 0.8031, respectively). TWEAK and CDCP1 have the potential to serve as biomarkers for early prediction of postmenopausal osteoporosis.

Teriparatide in postmenopausal osteoporosis: uncovering novel insights into efficacy and safety compared to other treatments - a systematic review and meta-analysis.

Objective: The aim of the study was to evaluate the efficacy and safety of teriparatide compared to other treatments for postmenopausal osteoporosis. Methods: A review of studies from 2000 to January 2023 analyzed randomized controlled trials on postmenopausal women treated with teriparatide (PTH 1-34), comparing it to placebo or other osteoporosis treatments. The analysis focused on bone mineral density (BMD), bone turnover markers, and clinical outcomes, employing Review Manager 5.4.1 and the RoB 2 tool for bias assessment. Results: Our analysis of 23 randomized controlled trials (RCTs) found that PTH (134) treatment significantly increased lumbar spine BMD (mean difference (MD) = 0.02, 95% CI: 0.01-0.03) and femoral neck BMD (MD = 0.01, 95% CI: 0.00-0.01). However, there were no significant changes in total hip and radial bone BMD among the 3536 and 2046 participants, respectively. We also found that PTH (1-34) increased P1NP in a larger cohort (n = 1415) when compared to osteocalcin (n = 206). Although the risk of adverse events increased (relative risk (RR) = 1.65, 95% CI: 1.32-2.07), the incidence of fractures decreased significantly (RR = 0.57, 95% CI: 0.45-0.072), with no significant difference observed in mortality rates between treatment and control groups. Conclusion: Teriparatide improves lumbar spine and femoral neck BMD in postmenopausal women. Particularly notable is the novel finding regarding its effect on radius BMD, an area less explored in previous research. Despite an uptick in adverse events, the marked decrease in fracture incidence confirms its clinical utility for high-risk osteoporosis patients, highlighting the necessity for ongoing investigations into its full skeletal effects.

Similarities and differences between European guidelines for the management of postmenopausal osteoporosis.

We conducted a review of 10 national guidelines from five EU countries to identify similarities or differences in recommendations for the management of patients with osteoporosis. We found general alignment of key recommendations; however, there are notable differences, largely attributed to country-specific approaches to risk assessment and reimbursement conditions. INTRODUCTION: The classification of fracture risk is critical for informing treatment decisions for post-menopausal osteoporosis. The aim of this review was to summarise 10 national guidelines from five European countries, with a focus on identifying similarities or differences in recommendations for the management of patients with osteoporosis. METHODS: We summarised the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Disease-International Osteoporosis Foundation guidelines and reviewed guidelines from France, Germany, Italy, Spain and the UK. RESULTS: The approach to risk assessment differed across the guidelines. In France, and Spain, risk assessment was based on DXA scans and presence of prior fractures, whereas UK, German and Italian guidelines recommended use of a validated risk tool. These differences led to distinct definitions of very high and high-risk patients. Guidelines aligned in recommending antiresorptive and anabolic agents as pharmacologic options for the management of osteoporosis, with sequential treatment recommended. There was agreement that patients at high or very high risk of fracture or with severe osteoporosis should receive anabolic agents first, followed by antiresorptive drugs. Variations were identified in recommendations for follow up of patients on anti-osteoporosis therapies. Reimbursement conditions in each country were a key difference identified. CONCLUSIONS: Criteria for risk assessment of fractures differ across European guidelines which may impact treatment and access to anabolic agents. Harmonisation across EU guidelines may help identify patients eligible for treatment and impact treatment uptake. However, country-specific reimbursement and prescribing processes may present a challenge to achieving a consistent approach across Europe.

Estrogen deficiency-mediated osteoimmunity in postmenopausal osteoporosis.

Postmenopausal osteoporosis (PMO) is a common disease associated with aging, and estrogen deficiency is considered to be the main cause of PMO. Recently, however, osteoimmunology has been revealed to be closely related to PMO. On the one hand, estrogen deficiency directly affects the activity of bone cells (osteoblasts, osteoclasts, osteocytes). On the other hand, estrogen deficiency-mediated osteoimmunity also plays a crucial role in bone loss in PMO. In this review, we systematically describe the progress of the mechanisms of bone loss in PMO, estrogen deficiency-mediated osteoimmunity, the differences between PMO patients and postmenopausal populations without osteoporosis, and estrogen deficiency-mediated immune cells (T cells, B cells, macrophages, neutrophils, dendritic cells, and mast cells) activity. The comprehensive summary of this paper provides a clear knowledge context for future research on the mechanism of PMO bone loss.

Possible mechanisms underlying the regulation of postmenopausal osteoporosis by follicle-stimulating hormone.

Objective: To explore the possible mechanisms by which follicle-stimulating hormone (FSH) regulates postmenopausal osteoporosis through the FSH/FSH receptor (FSHr)/G protein/C/EBPß/heat shock protein 90 alpha (HSP90α) signalling pathways. Methods: We measured serum FSH, luteinising hormone (LH), and HSP90α levels in the serum and adipose tissue of women of childbearing age and menopausal status. In the in vivo studies, 12 B57CL female mice were divided equally into Sham, OVX, and OVX + FSHr Blocker groups. Serum levels of alkaline phosphatase, FSH, and HSP90α, along with StRACP vitality, were determined, and femur micro-computed tomography was performed. Additionally, FSH, FSHr, G protein, C/EBPß, and HSP90α levels were assessed using quantitative polymerase chain reaction. Finally, we divided the human multiple myeloma cell line U266 into three groups. The activity of tartrate-resistant acid phosphatase (TRAP) in the supernatant at different stages was detected, and myeloma cells were stained with TRAP. Results: HSP90α levels in adipose tissue supernatant and serum were lower in women of childbearing age than in menopausal women (P < 0.05). Serum FSH and HSP90α levels demonstrated a strong correlation. Treatment with FSHr blockers resulted in decreased FSH, FSHr, G protein, C/EBPß, and HSP90α levels in mice. TRAP staining of osteoclast-like cells exhibited a significantly higher intensity in the M-CSF + RANKL + recombinant HSP90α group than in the M-CSF + RANKL and blank control groups (P < 0.05). Conclusions: Our results indicate that FSH promotes HSP90α secretion by adipocytes via the FSHr/G protein/C/EBPß pathway. This mechanism affects osteoclast activity and exacerbates osteoporosis.

Suppressing ERp57 diminishes osteoclast activity and ameliorates ovariectomy-induced bone loss via the intervention in calcium oscillation and the calmodulin/calcineurin/Nfatc1 pathway.

Background: Increased osteoclast activity constitutes the primary etiology of excessive bone erosion in postmenopausal osteoporosis. ERp57, otherwise referred to as protein disulfide isomerase A3 (PDIA3), plays a crucial role in the regulation of intracellular calcium signaling. This is documented to exert a profound impact on osteoclast differentiation and functionality. Methods: To ascertain the potential role of ERp57 in disease progression, prevention, and treatment, network pharmacology and bioinformatics analyses were conducted in relation to postmenopausal osteoporosis and ERp57 inhibitor (Loc14). Then, subsequent experimental verifications were employed in vitro on osteoclast and osteoblast, and in vivo on ovariectomy (OVX) mice models. Results: Multiple enrichment analyses suggested that the "calcium signaling pathway" may constitute a potential avenue for therapeutic intervention by Loc14 in the treatment of postmenopausal osteoporosis. In vitro experiments demonstrated inhibition of ERp57 could block osteoclast differentiation and function by interfering with the expression of osteoclast marker genes (Traf6, Nfatc1, and Ctsk). Further mechanisms studies based on calcium imaging, qPCR, and WB established that ERp57 inhibitor (Loc14) could obstruct calcium oscillation in osteoclast precursor cells (OPCs) by limiting the entry sources of cytosolic Ca2+ and interfering with calmodulin/calcineurin/Nfatc1 pathway. Evidence from Micro-CT scanning and double calcein labeling confirmed that the application of Loc14 in vivo could alleviate bone loss and partially reversed the osteogenic impairment caused by OVX in mice. Conclusions: Our findings proved the suppressive effects of Loc14 on osteoclastogenesis via attenuating calcium oscillation and associated singling pathways, providing ERp57 as a potential therapeutic target for postmenopausal osteoporosis.

Diversity of the diet is correlated with osteoporosis in post-menopausal women: an Iranian case-control study.

Background: Proper nutrition is a crucial factor in preventing osteoporosis, a significant pathological cause linked to skeletal weakness; this study investigated the relationship between dietary diversity score and food group diversity score with osteoporosis in postmenopausal women. Methods: This case-control study was conducted on 378 menopausal women aged 45-85 in Tehran, Iran. The age-matching method to control the confounding effect of age was used. The method of dual-energy X-ray absorptiometry (DXA) was used for assessing the bone mineral density of lumbar vertebrae and femoral neck. The bone mass status was evaluated with WHO criteria. All subjects were divided into the osteoporosis group and the non-osteoporosis group according to their T-score. A convenience sampling method was utilized to select the participants, which included two groups: case (n = 189) and control (n = 189). Data was collected using demographic and anthropometric information questionnaires, a valid 147 item food frequency questionnaire, and a physical activity questionnaire. Statistical analyses were conducted using SPSS-26, and p-values less than 0.05 were deemed to be statistically significant. Results: The results indicated significant differences in weight, body mass index, physical activity, smoking, and alcohol use between the two groups. The mean ± standard deviation of dietary diversity score (DDS) was lower in participants with osteoporosis (case) (3.31 ± 1.26) than in control (4.64 ± 1.33) (p < 0.001). The mean ± standard deviation of diversity score of cereals, fruits, and vegetables in the osteoporosis group (respectively: 0.71 ± 0.21, 0.94 ± 0.76, and 0.45 ± 0.44) was less than the control group (respectively: 0.80 ± 0.21, 1.64 ± 0.55 and 0.87 ± 0.42) (p < 0.001). After adjusting the confounding variables, the risk of osteoporosis had an inverse relationship with the diversity score of vegetable (OR = 0.16; 95%CI: 0.07-0.35), bread and cereal (OR = 0.21; 95% CI: 0.05-0.87) and fruit (OR = 0.35; 95%CI: 0.22-0.56) (p < 0.05). Nevertheless, no discernible correlation was seen between the tertiles of DDS, dairy and meat diversity score, and osteoporosis. Conclusion: We found a correlation between the diversity score of fruits, vegetables, and grains and osteoporosis. However, there is no significant correlation between the DDS triads and the diversity score of dairy products and meats with osteoporosis.

Effects of tibolone combined with zoledronic acid on bone density, bone metabolism, and pain in postmenopausal patients with osteoporosis.

OBJECTIVE: To explore the efficacy and safety of tibolone combined with zoledronic acid in the treatment of postmenopausal osteoporosis (PMO). METHODS: We conducted a retrospective analysis of 121 PMO patients from March 2019 to July 2021. Patients were divided into two groups based on treatment regimen: an observation group (n=62) receiving zoledronic acid combined with tibolone and a control group (n=59) receiving tibolone monotherapy. We evaluated and compared therapeutic efficacy, bone mineral density, bone metabolism markers (osteocalcin, serum C-terminal telopeptide of type I collagen, and bone alkaline phosphatase), pain, knee joint function, incidence of fragility fractures, and adverse reactions. Logistic regression analysis was used to evaluate risk factors affecting treatment efficacy. RESULTS: The observation group showed a significantly higher therapeutic effect (96.77%) compared to the control group (83.05%), and a lower incidence of fragility fractures (P=0.012). Before treatment, there were no significant differences in bone mineral density, bone metabolism markers, pain status, or knee function between the two groups (all P>0.05). However, after treatment, evaluations showed marked improvements in these parameters in both groups, with more significant enhancements observed in the observation group (all P<0.001). The incidence of adverse reactions did not significantly differ between the groups (20.97% vs 13.56%, P=0.282). Logistic regression analysis identified the use of tibolone combined with zoledronic acid as a protective factor for effective treatment. CONCLUSIONS: Tibolone combined with zoledronic acid significantly increases bone mineral density, improves bone metabolism, and reduces pain in PMO patients, with a safety profile comparable to that of monotherapy. This regimen should be considered for clinical use in treating PMO.

Correlation study: Bone density and circulating inflammatory markers in postmenopausal patients.

OBJECTIVE: This study aims to investigate the correlation between changes in bone mineral density (BMD) in postmenopausal women and circulating inflammatory markers. METHODS: This retrospective study focused on postmenopausal women admitted to the orthopedic department of Suzhou Benq Medical Center from June 2022 to December 2023, following predetermined inclusion and exclusion criteria. We retrospectively collected data on initial blood routine test results and bone density measurements for all study subjects upon admission, including parameters such as white blood cell count (WBC), C-reactive protein, interleukin-6 (IL-6), and procalcitonin (PCT). Additionally, the systemic immune-inflammation index (SII) was calculated using neutrophil count, lymphocyte count, and platelet count. Statistical analyses using SPSS and GraphPad software were performed to assess the correlation between bone density and inflammatory markers. RESULTS: Patients were classified into three groups based on BMD results, including 60 individuals in the osteoporosis (OP) group, 127 individuals in the osteopenia group, and 37 individuals in the Normal group, respectively. Principal component analysis analysis suggested that WBC, SII, and postmenopausal OP (PMOP) held significant feature values. Correlation analysis indicated a correlation between WBC (p = 0.021), IL-6 (p = 0.044), SII (p = 0.034), and PMOP. One-way ANOVA analysis revealed significant differences in IL-6 (p = 0.0179), SII (p = 0.0210), and PCT (p = 0.0200) among the three groups. Finally, ROC curve analysis demonstrated that SII (area under the curve = 0.716) has predictive value for PMOP. CONCLUSION: This study identified a certain predictive value for PMOP through the assessment of inflammatory markers in peripheral blood using routine blood tests.

Association of dietary live microbe intake with prevalence of osteoporosis in US postmenopausal women: a cross-sectional study.

The association between live microbe intake and osteoporosis in postmenopausal women remains unknown. The research findings indicated that an increased intake of live microbes through dietary sources was associated with a low prevalence of osteoporosis among postmenopausal women. PURPOSE: To investigate the relationship between the consumption of live microbes in the diet and osteoporosis in postmenopausal women. METHODS: A cross-sectional investigation using data obtained from the National Health and Nutrition Examination Survey was conducted. Participants were classified into three groups by using the dietary live microbe classification system developed by Sanders. Dual x-ray absorptiometry was used to measure body mineral density, and osteoporosis was diagnosed according to the World Health Organization criteria. We conducted a crude and adjusted multivariate logistic regression analysis, and utilized the restricted cubic splines model to assess the correlation between the consumption of live microbes in the diet and osteoporosis in postmenopausal women. RESULTS: A total of 1378 women who had undergone menopause were enrolled in the study. After controlling for potential covariates, individuals with a high consumption of live microbes in their diet exhibited a notably low prevalence of osteoporosis in comparison to those with a low intake of dietary live microbes (odd ratio: 0.46, 95% confidence interval: 0.23, 0.93, P = 0.03). Subgroup analysis showed the stability of the results, and restricted cubic splines showed an approximate L-shape curve. CONCLUSIONS: In this research, a higher consumption of live microbes in the diet was linked to a low prevalence of osteoporosis in postmenopausal women.

Morinda Officinalis Polysaccharides Inhibit Osteoclast Differentiation by Regulating miR-214-3p/NEDD4L in Postmenopausal Osteoporosis Mice.

To investigate the potential mechanism of Morinda officinalis F. C. How polysaccharides (MOPs) in regulating osteoclast differentiation and apoptosis through miR-214-3p and its target protein. Ovariectomy was performed in 8-week female C57BL6 mice to establish the postmenopausal osteoporosis (PMOP) model. Mice were treated immediately with 500 mg/kg of MOPs (prevention group); others were treated 2 weeks after operation (treatment group). Left femur bone mineral density (BMD) was examined. RAW264.7 cells were administered with receptor activator of NF-κB ligand (RANKL) to establish the osteoclast (OC) model and treated with serum containing 1 or 2 g/kg of MOPs. Apoptosis-related indexes, miR-214-3p, and Expressed Developmentally Down-regulated 4-Like (NEDD4L) were detected by western blot, quantitative real-time-reverse transcription polymerase chain reaction (qRT-PCR), and flow cytometry. OC received a miR-214-3p inhibitor or NEDD4L small interfering RNA (siRNA). MOPs reversed the PMOP-induced changes in bones. Compared with the RANKL group, MOPs increased the apoptosis and related markers in OCs. MOPs decreased the femur miR-214-3p of PMOP mice (P < 0.001). Higher concentrations of MOPs reversed the upregulation of miR-214 mRNA in OCs (P < 0.001). miR-214-3p inhibitor increased the expression of Bax and CC3 (P < 0.01) and decreased the expression of Bcl-2 (P < 0.05). NEDD4L is targeted by miR-214. NEDD4L was upregulated in the RANKL + MOPs group (P < 0.01). miR-214-3p inhibitor increased the upregulation of NEDD4L induced by MOPs (P < 0.05). siRNA NEDD4L significantly reversed the inhibition of MOPs on osteoclast differentiation with miR-214-3p inhibitor (P < 0.01). MOPs effectively prevent PMOP by inhibiting osteoclastogenesis and inducing OC apoptosis through the miR-214-3p/NEDD4L pathway.

IL-16 Mediates the Effect of Circulating Metabolites on Postmenopausal Osteoporosis: A Two-Step, Multivariable Mendelian Randomization Study.

Objectives: This study aimed to explore the relationship between circulating metabolites and postmenopausal osteoporosis (PMOP) and to assess the mediating role of inflammatory factors. Methods: Utilizing summary-level data from genome-wide association studies (GWAS) and employing a Mendelian Randomization approach, a two-sample MR analysis was conducted to assess the relationship between circulating metabolites and PMOP. Additionally, a two-step MR was used to quantify the mediating impact of inflammatory factors on the effect of circulating metabolites on PMOP. Results: The results revealed a significant association between certain metabolites and the risk of PMOP, notably the ratio of free cholesterol to total lipids in very large VLDL particles (OR: 1.399, 95% CI: 1.002-1.954, p = 0.048) and IL-16 (OR: 0.773, 95% CI: 0.608-0.983, p = 0.036). IL-16 was found to partially mediate the impact of circulating metabolites on PMOP, with a mediation effect of 10.4%. Conclusion: This study underscores the crucial role of circulating metabolites and inflammatory factors in PMOP pathogenesis. A causal relationship between circulating metabolites and PMOP was established, with IL-16 mediating some effects. These findings hold promise for clinical applications in early detection, personalized medicine, and the identification of therapeutic targets for PMOP.

Bu-Sui-Dan Enhances Osteoblast Differentiation by Upregulating VGLL4 to Counteract TEAD4-Mediated RUNX2 Transcription Suppression in Ovariectomized Rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Postmenopausal osteoporosis (PMOP) has been considered as a major causative factor for bone-joint pain and inducing pathologic fractures. Bu-Sui-Dan (BSD), a classic ancient herbal formula, has been shown to exhibit osteoprotective effects by promoting bone marrow development and bone growth. However, the exact mechanism of BSD are still unexplored. AIM OF STUDY: The study aimed to investigate the protective effect of BSD against osteoporotic injury, and to explore whether BSD regulated BMSCs' osteogenic differentiation by targeting VGLL4, which in turn improved PMOP. MATERIALS AND METHODS: The anti-osteoporotic effect of BSD was studied in ovariectomized (OVX) rats and bone marrow mesenchymal stem cells (BMSCs). Micro-CT imaging and HE staining were performed, and the levels of osteogenic protein RUNX2 and osteogenesis-related factor VGLL4 were determined. Co-immunoprecipitation (Co-IP) was further employed to delve into the effects of BSD on the interactions between TEAD4 and RUNX2. The key osteogenic factors 1ALP, COLl1A1, and Osterix expression were detected by RT-qPCR. Co-IP and proximity ligation assay (PLA) were employed to scrutinize the influence of BSD on TEAD4 and RUNX2 inter-binding. Moreover, VGLL4 knockdown in BMSCs was conducted to confirm the role of VGLL4 in the therapeutic mechanism of BSD. RESULTS: BSD showed a dose-dependent protective effect against osteoporotic injury, as evidenced by improvement in bone volume, bone microarchitecture, and histomorphometry. Additionally, BSD treatment increased the levels of RUNX2 and its downstream target genes including ALP, COL1A1, and Osterix. Moreover, BSD upregulated VGLL4 expression and lessened TEAD4-RUNX2 interactions. In BMSCs experiment, BSD-containing serum could promote osteogenic differentiation of BMSCs, boosted the expression of osteogenesis-related factors and VGLL4 level. The knockdown of VGLL4 in BMSCs diminished the promotion effect of BSD in osteoblast differentiation, suggesting that VGLL4 play a vital role in the therapeutic effects exerted by BSD. CONCLUSION: BSD ameliorated osteoporosis injury and promoted osteoblast differentiation through upregulation of VGLL4 levels, which in turn antagonized TEAD4-mediated RUNX2 transcriptional repression. Our study implied that BSD may be an osteoporosis therapeutic agent.

Efficacy and safety of odanacatib in the treatment of postmenopausal women with osteoporosis: a meta-analysis.

BACKGROUND: Osteoporosis, a systemic skeletal disease, seriously affects the quality of life in postmenopausal women. As one type of cathepsin K (CatK) inhibitor, odanacatib (ODN) is a fresh medication for osteoporosis. Considering the potential of ODN, we further examined the effect and safety of ODN for postmenopausal osteoporosis (PMOP) with a meta-analysis. METHODS: PubMed, EMBASE, Cochrane Library, and Web of Science were searched for eligible studies from inception to December 29th, 2023. After that, we conducted a comprehensive meta-analysis following PRISMA guidelines. Risk of bias was meticulously investigated with the Cochrane Collaboration's tool. Efficacy was assessed with bone mineral density (BMD) at different sites (lumbar spine, trochanter, radius, femoral neck) and biomarkers of bone turnover (P1NP, uNTx/Cr, s-CTx, BSAP). Safety was evaluated by analyzing total, serious, other, and skin adverse events (AEs). RESULTS: Four random clinical trials (RCTs) were involved in our research. All trials were rated as having high quality and met the eligibility criteria. In the current research, ODN was found to elevate BMD at lumbar spine, femoral neck, total hip, trochanter and forearm, while it decreased the levels of serum C-telopeptides of type I collagen (s-CTx) as well as urinary N-telopeptide/creatinine ratio (uNTx/Cr). No significant differences were observed in AEs between the ODN group and the control group. CONCLUSIONS: ODN is a promising alternative for the treatment of PMOP on account of its excellent efficacy and credible safety. Unclear links between ODN and cardiovascular AEs require further research to clarify.

miR-18a-5p promotes osteogenic differentiation of BMSC by inhibiting Notch2.

Postmenopausal osteoporosis (PMOP) is a metabolic disorder characterized by the loss of bone density, which increases the risk of developing complications such as fractures. A pivotal factor contributing to the onset of PMOP is the diminished osteogenic differentiation capacity of bone marrow mesenchymal stem cells (BMSCs). MicroRNAs (miRNAs) play a substantial role in this process; however, their specific impact on regulating BMSCs osteogenesis remains unclear. Studies have evidenced a reduced expression of miR-18a-5p in PMOP, and concomitantly, our observations indicate an augmented expression of miR-18a-5p during the osteogenic differentiation of BMSCs. This investigation seeks to elucidate the regulatory influence of miR-18a-5p on BMSC osteogenic differentiation and the underlying mechanisms. In vitro experiments demonstrated that the overexpression of miR-18a-5p facilitated the osteogenic differentiation of BMSCs, while the downregulation of miR-18a-5p yielded converse outcomes. Mechanistically, We employed bioinformatics techniques to screen out the target gene Notch2 of miR-18a-5p. Subsequently, dual-luciferase reporter gene assays and rescue experiments substantiated that miR-18a-5p promotes BMSC osteogenic differentiation by suppressing Notch2. Finally, miR-18a-5p was overexpressed via adenovirus injection into the femoral bone marrow cavity, with results demonstrating its capability to enhance osteogenic differentiation and alleviate PMOP symptoms. Our findings disclose that miR-18a-5p fosters osteogenic differentiation of BMSC by inhibiting Notch2, thereby offering novel targets and strategies for PMOP treatment.

A two-pronged approach to inhibit ferroptosis of MSCs caused by the iron overload in postmenopausal osteoporosis and promote osseointegration of titanium implant.

Postmenopausal osteoporosis (PMOP) is a prevalent condition among elderly women. After menopause, women exhibit decreased iron excretion, which is prone to osteoporosis. To design a specific titanium implant for PMOP, we first analyze miRNAs and DNA characteristics of postmenopausal patients with and without osteoporosis. The results indicate that iron overload disrupts iron homeostasis in the pathogenesis of PMOP. Further experiments confirm that iron overload can cause lipid peroxidation and ferroptosis of MSCs, thus breaking bone homeostasis. Based on the findings above, we have designed a novel Ti implant coated with nanospheres of caffeic acid (CA) and deferoxamine (DFO). CA can bind on the Ti surface through the two adjacent phenolic hydroxyls and polymerize into polycaffeic acid (PCA) dimer, as well as the PCA nanospheres with the repetitive 1,4-benzodioxan units. DFO was grafted with PCA through borate ester bonds. The experimental results showed that modified Ti can inhibit the ferroptosis of MSCs in the pathological environment of PMOP and promote osseointegration in two main ways. Firstly, DFO was released under high oxidative stress, chelating with excess iron and decreasing the labile iron pool in MSCs. Meanwhile, CA and DFO activated the KEAP1/NRF2/HMOX1 pathway in MSCs and reduced the level of intracellular lipid peroxidation. So, the ferroptosis of MSCs is inhibited by promoting the SLC7A11/GSH/GPX4 pathway. Furthermore, the remained CA coating on the Ti surface could reduce the extracellular oxidative stress and glutathione level. This study offers a novel inspiration for the specific design of Ti implants in the treatment of PMOP.

Bone Marrow Adipose Tissue as a Critical Regulator of Postmenopausal Osteoporosis - A Concise Review.

Postmenopausal osteoporosis (PMOP) is a major health problem affecting millions of women worldwide. PMOP patients are often accompanied by abnormal accumulation of bone marrow adipose tissue (BMAT). BMAT is a critical regulator of bone homeostasis, and an increasing BMAT volume is negatively associated with bone mass reduction or fracture. BMAT regulates bone metabolism via adipokines, cytokines and the immune system, but the specific mechanisms are largely unknown. This review emphasizes the impact of estrogen deficiency on bone homeostasis and BMAT expansion, and the mechanism by which BMAT regulates PMOP, providing a promising strategy for targeting BMAT in preventing and treating PMOP.

Prevalence of postmenopausal osteoporosis in Morocco: a systematic review and meta-analysis.

INTRODUCTION: This systematic review and meta-analysis was conducted as part of the update of Moroccan recommendations for the management of postmenopausal osteoporosis. Its aim was to estimate the prevalence of postmenopausal osteoporosis in Morocco, based on available bibliographic data. METHODS: We conducted a systematic search of the Medline/PubMed, Scopus, and Embase databases to identify articles published between January 2000 and January 2024. We included all observational studies reporting the prevalence of osteoporosis in postmenopausal women in Morocco. Two reviewers independently contributed to the study selection and data extraction. We assessed the risk of bias in the included studies using the Joanna Briggs Institute tool. Statistical analyses were performed using Stata with the Freeman-Tukey double arcsine transformation. Heterogeneity was assessed using the I2 test statistic. Meta-regression analysis was used to investigate the effect of the date on the prevalence. Publication bias was assessed by DOI plots and the LFK index. RESULTS: An electronic search found a total of 161 citations from the databases. After excluding the irrelevant articles, 17 eligible studies were included. This meta-analysis included 5097 postmenopausal women. The pooled prevalence of postmenopausal osteoporosis was 32% (95% CI 28-36). Heterogeneity was statistically significant (I2 = 89.67%). There was no significant difference between subgroup analyses performed by risk of bias and sample size. The prevalence rate was significantly higher in 2006-2012 (36%; 95% CI 31-42; I2 = 88.7%; p < 0.001) than in 2013-2019 (27%; 95% CI 22-32; I2 = 85.9%; p < 0.001). Meta-regression showed that the prevalence of osteoporosis decreases very slightly (0.016% per year). This decrease becomes nonsignificant if only studies with a low risk of bias are included in the meta-regression (coefficient - 7.77, p = 0.667, I2 0%). No publication bias was detected in this meta-analysis. CONCLUSION: Our results indicate that postmenopausal osteoporosis is prevalent in Morocco, which is a developing country; however, the prevalence of this disease is aligned with that of industrialized countries.