Estrogen, cytokines, and pathogenesis of postmenopausal osteoporosis

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.

Exploring the Role of Hormones and Cytokines in Osteoporosis Development

The disease of osteoporosis is characterized by impaired bone structure and an increased risk of fractures. There is a significant impact of cytokines and hormones on bone homeostasis and the diagnosis of osteoporosis. As defined by the World Health Organization (WHO), osteoporosis is defined as having a bone mineral density (BMD) that is 2.5 standard deviations (SD) or more below the average for young and healthy women (T score < -2.5 SD). Cytokines and hormones, particularly in the remodeling of bone between osteoclasts and osteoblasts, control the differentiation and activation of bone cells through cytokine networks and signaling pathways like the nuclear factor kappa-B ligand (RANKL)/the receptor of RANKL (RANK)/osteoprotegerin (OPG) axis, while estrogen, parathyroid hormones, testosterone, and calcitonin influence bone density and play significant roles in the treatment of osteoporosis. This review aims to examine the roles of cytokines and hormones in the pathophysiology of osteoporosis, evaluating current diagnostic methods, and highlighting new technologies that could help for early detection and treatment of osteoporosis.

New potential selective estrogen receptor modulators in traditional Chinese medicine for treating menopausal syndrome

Women go through several predictable conditions and symptoms during menopause that are caused by age, changes in sex hormone levels, and other factors. Conventional menopause hormone therapy has raised serious concerns about the increased risks of cancers, blood clots, depression, etc. Selective estrogen receptor modulators (SERMs) that can be both agonists and antagonists of estrogen receptors in a tissue-specific manner are being developed to reduce the health concerns associated with menopause hormone therapy. Here, we have searched the Chinese national traditional Chinese medicine (TCM) patent database to identify potential SERM-like compounds with reduced health risks. TCM has been widely used for treating complex symptoms associated with menopause syndrome and thus can be a particularly rich source for pharmaceutical alternatives with SERM properties. After extensive literature review and molecular simulation, we conclude that protopanaxatriol, paeoniflorin, astragalin, catalpol, and hyperoside among others may be particularly promising as SERM-like compounds in treating the menopausal syndrome. Compounds in TCM hold promise in yielding comparable outcomes to hormone therapy but with reduced associated risks, thus presenting promising avenues for their clinical applications.

Probiotics enhance alveolar bone microarchitecture, intestinal morphology and estradiol levels in osteoporotic animals

BACKGROUND AND OBJECTIVE

Osteoporosis is associated with bone microarchitecture alterations, and the depletion of estrogen during menopause is a major contributing factor to its development. The literature highlights the noteworthy role of gut microbiota in bone metabolism, particularly in the progression of osteoporosis. Periodontal disease leads to alveolar bone loss, which may be influenced by estrogen deficiency, and this mechanism is intricately associated with an imbalance in systemic microbiota. The aim of this study was to evaluate the effects of Bifidobacterium animalis subsp. lactis HN019 (B. lactis HN019) and Lacticaseibacillus casei 01 (L. casei 01) administrations on an osteoporosis animal model.

MATERIALS AND METHODS

Thirty-three female rats were randomly divided into three groups: control (C-OVX), C-OVX-HN019 and C-OVX-LC01. All animals were ovariectomized. In groups C-OVX-HN019 and C-OVX-LC01, the probiotics were administered for 4 months. All animals were euthanized after 16 weeks from ovariectomy. Microtomographic, histopathological and immunohistochemical examinations were conducted on periodontal tissues, whereas histomorphometry, histopathological and immunohistochemical analyses were carried out on the intestine. The levels of estradiol were assessed in blood using an immunoenzymatic assay. The data were subjected to statistical analyses (p < .05).

RESULTS

The C-OVX-LC01 group exhibited a significant reduction in alveolar bone porosity and an increase in connective tissue density compared to C-OVX (p < .05). The C-OVX-HN019 and C-OVX-LC01 groups presented reduced expression of TRAP and RANKL compared to the C-OVX (p < .05). The C-OVX group presented villi defects, mild neutrophil infiltration, decrease in both villous height and intestinal crypts and reduced expression of intestinal junctional epithelium markers e-cadherin and claudin 01 compared to C-OVX-HN019 and C-OVX-LC01 (p < .05). The C-OVX group had lower estradiol levels than C-OVX-HN019 and C-OVX-LC01 (p < .05).

CONCLUSION

The probiotic therapy promoted a reduction in alveolar bone destruction and intestinal permeability as well as an increase in estradiol levels in ovariectomized rats. Specifically, the probiotic strain Lacticaseibacillus casei 01 exhibited greater effectiveness compared to Bifidobacterium animalis subsp. lactis HN019, indicating strain-dependent outcomes.

Irisin as an agent for protecting against osteoporosis: A review of the current mechanisms and pathways

BACKGROUND

Osteoporosis is recognized as a skeletal disorder characterized by diminished bone tissue quality and density. Regular physical exercise is widely acknowledged to preserve and enhance bone health, but the detailed molecular mechanisms involved remain unclear. Irisin, a factor derived from muscle during exercise, influences bone and muscle. Since its discovery in 2012, irisin has been found to promote bone growth and reduce bone resorption, establishing a tangible link between muscle exertion and bone health. Consequently, the mechanism by which irisin prevents osteoporosis have attracted significant scientific interest.

AIM OF THE REVIEW

This study aims to elucidate the multifaceted relationship between exercise, irisin, and bone health. Focusing on irisin, a muscle-derived factor released during exercise, we seek to understand its role in promoting bone growth and inhibiting resorption. Through a review of current research article on irisin in osteoporosis, Our review provides a deep dive into existing research on influence of irisin in osteoporosis, exploring its interaction with pivotal signaling pathways and its impact on various cell death mechanisms and inflammation. We aim to uncover the molecular underpinnings of how irisin, secreted during exercise, can serve as a therapeutic strategy for osteoporosis.

KEY SCIENTIFIC CONCEPTS OF THE REVIEW

Irisin, secreted during exercise, plays a vital role in bridging muscle function to bone health. It not only promotes bone growth but also inhibits bone resorption. Specifically, Irisin fosters osteoblast proliferation, differentiation, and mineralization predominantly through the ERK, p38, and AMPK signaling pathways. Concurrently, it regulates osteoclast differentiation and maturation via the JNK, Wnt/β-catenin and RANKL/RANK/OPG signaling pathways. This review further delves into the profound significance of irisin in osteoporosis and its involvement in diverse cellular death mechanisms, including apoptosis, autophagy, ferroptosis, and pyroptosis.

A prospective study of vitamin D, proinflammatory cytokines, and risk of fragility fractures in women on aromatase inhibitors for breast cancer

BACKGROUND

Vitamin D is critical to bone health by regulating intestinal absorption of calcium, whereas proinflammatory cytokines, including IL-1, IL-6, IL-12, and TNF-α, are known to increase bone resorption. We hypothesized that vitamin D and these cytokines at the time of breast cancer diagnosis were predictive for fragility fractures in women receiving aromatase inhibitors (AIs).

METHODS

In a prospective cohort of 1,709 breast cancer patients treated with AIs, we measured the levels of 25-hydroxyvitamin D (25OHD), IL-1β, IL-6, IL-12, and TNF-α from baseline blood samples. The associations of these biomarkers were analyzed with bone turnover markers (BALP and TRACP), bone regulatory markers (OPG and RANKL), bone mineral density (BMD) close to cancer diagnosis, and risk of fragility fractures during a median of 7.5 years of follow up.

RESULTS

Compared to patients with vitamin D deficiency, patients with sufficient levels had higher bone turnover, lower BMD, and higher fracture risk; the latter became non-significant after controlling for covariates including BMD and no longer existed when patients taking vitamin D supplement or bisphosphonates or with history of fracture or osteoporosis were excluded. There was a non-significant trend of higher levels of IL-1β and TNF-α associated with higher risk of fracture (highest vs. lowest tertile, IL-1β: adjusted HR=1.37, 95% CI=0.94-1.99; TNF-α: adjusted HR=1.38, 95% CI=0.96-1.98).

CONCLUSIONS

Our results do not support proinflammatory cytokines or vitamin D levels as predictors for risk of fragility fractures in women receiving AIs for breast cancer.

Analysis and validation of biomarkers of immune cell-related genes in postmenopausal osteoporosis: An observational study

Postmenopausal osteoporosis (PMOP) is a common metabolic inflammatory disease. In conditions of estrogen deficiency, chronic activation of the immune system leads to a hypo-inflammatory phenotype and alterations in its cytokine and immune cell profile, although immune cells play an important role in the pathology of osteoporosis, studies on this have been rare. Therefore, it is important to investigate the role of immune cell-related genes in PMOP. PMOP-related datasets were downloaded from the Gene Expression Omnibus database. Immune cells scores between high bone mineral density (BMD) and low BMD samples were assessed based on the single sample gene set enrichment analysis method. Subsequently, weighted gene co-expression network analysis was performed to identify modules highly associated with immune cells and obtain module genes. Differential analysis between high BMD and low BMD was also performed to obtain differentially expressed genes. Module genes are intersected with differentially expressed genes to obtain candidate genes, and functional enrichment analysis was performed. Machine learning methods were used to filter out the signature genes. The receiver operating characteristic (ROC) curves of the signature genes and the nomogram were plotted to determine whether the signature genes can be used as a molecular marker. Gene set enrichment analysis was also performed to explore the potential mechanism of the signature genes. Finally, RNA expression of signature genes was validated in blood samples from PMOP patients and normal control by real-time quantitative polymerase chain reaction. Our study of PMOP patients identified differences in immune cells (activated dendritic cell, CD56 bright natural killer cell, Central memory CD4 T cell, Effector memory CD4 T cell, Mast cell, Natural killer T cell, T follicular helper cell, Type 1 T-helper cell, and Type 17 T-helper cell) between high and low BMD patients. We obtained a total of 73 candidate genes based on modular genes and differential genes, and obtained 5 signature genes by least absolute shrinkage and selection operator and random forest model screening. ROC, principal component analysis, and t-distributed stochastic neighbor embedding down scaling analysis revealed that the 5 signature genes had good discriminatory ability between high and low BMD samples. A logistic regression model was constructed based on 5 signature genes, and both ROC and column line plots indicated that the model accuracy and applicability were good. Five signature genes were found to be associated with proteasome, mitochondria, and lysosome by gene set enrichment analysis. The real-time quantitative polymerase chain reaction results showed that the expression of the signature genes was significantly different between the 2 groups. HIST1H2AG, PYGM, NCKAP1, POMP, and LYPLA1 might play key roles in PMOP and be served as the biomarkers of PMOP.

Prune Consumption Attenuates Proinflammatory Cytokine Secretion and Alters Monocyte Activation in Postmenopausal Women: Secondary Outcome Analysis of a 12-Mo Randomized Controlled Trial: The Prune Study

BACKGROUND

Proinflammatory cytokines are implicated in the pathophysiology of postmenopausal bone loss. Clinical studies demonstrate that prunes prevent bone mineral density loss; however, the mechanism underlying this effect is unknown.

OBJECTIVE

We investigated the effect of prune supplementation on immune, inflammatory, and oxidative stress markers.

METHODS

A secondary analysis was conducted in the Prune Study, a single-center, parallel-arm, 12-mo randomized controlled trial of postmenopausal women (55-75 y old; n = 235 recruited; n = 183 completed) who were assigned to 1 of 3 groups: "no-prune" control, 50 g prune/d and 100 g prune/d groups. At baseline and after 12 mo of intervention, blood samples were collected to measure serum high-sensitivity C-reactive protein (hs-CRP), serum total antioxidant capacity (TAC), plasma 8-isoprostane, proinflammatory cytokines [interleukin (IL)-1β, IL-6, IL-8, monocyte chemoattractant protein-1, and tumor necrosis factor (TNF)-α] concentrations in plasma and lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs) culture supernatants, and the percentage and activation of circulating monocytes, as secondary outcomes.

RESULTS

Prune supplementation did not alter hs-CRP, TAC, 8-isoprostane, and plasma cytokine concentrations. However, percent change from baseline in circulating activated monocytes was lower in the 100 g prune/d group compared with the control group (mean ± SD, -1.8% ± 4.0% in 100 g prune/d compared with 0.1% ± 2.9% in control; P < 0.01). Furthermore, in LPS-stimulated PBMC supernatants, the percent change from baseline in TNF-α secretion was lower in the 50 g prune/d group compared with the control group (-4.4% ± 43.0% in 50 g prune/d compared with 24.3% ± 70.7% in control; P < 0.01), and the percent change from baseline in IL-1β, IL-6, and IL-8 secretion was lower in the 100 g prune/d group compared with the control group (-8.9% ± 61.6%, -4.3% ± 75.3%, -14.3% ± 60.8% in 100 g prune/d compared with 46.9% ± 107.4%, 16.9% ± 70.6%, 39.8% ± 90.8% in control for IL-1β, IL-6, and IL-8, respectively; all P < 0.05).

CONCLUSIONS

Dietary supplementation with 50-100 g prunes for 12 mo reduced proinflammatory cytokine secretion from PBMCs and suppressed the circulating levels of activated monocytes in postmenopausal women. This trial was registered at clinicaltrials.gov as NCT02822378.

Navigating Post-Traumatic Osteoporosis: A Comprehensive Review of Epidemiology, Pathophysiology, Diagnosis, Treatment, and Future Directions

Post-traumatic osteoporosis (PTO) presents a significant challenge in clinical practice, characterized by demineralization and decreased skeletal integrity following severe traumatic injuries. This literature review manuscript addresses the knowledge gaps surrounding PTO, encompassing its epidemiology, pathophysiology, risk factors, diagnosis, treatment, prognosis, and future directions. This review emphasizes the complexity of the etiology of PTO, highlighting the dysregulation of biomineralization processes, inflammatory cytokine involvement, hormonal imbalances, glucocorticoid effects, vitamin D deficiency, and disuse osteoporosis. Moreover, it underscores the importance of multidisciplinary approaches for risk mitigation and advocates for improved diagnostic strategies to differentiate PTO from other musculoskeletal pathologies. This manuscript discusses various treatment modalities, including pharmacotherapy, dietary management, and physical rehabilitation, while also acknowledging the limited evidence on their long-term effectiveness and outcomes in PTO patients. Future directions in research are outlined, emphasizing the need for a deeper understanding of the molecular mechanisms underlying PTO and the evaluation of treatment strategies' efficacy. Overall, this review provides a comprehensive overview of PTO and highlights avenues for future investigation to enhance clinical management and patient outcomes.

Pre-implantation teriparatide administration improves initial implant stability and accelerates the osseointegration process in osteoporotic rats

PURPOSE

Osteoporotic individuals who have dental implants usually require a prolonged healing time for osseointegration due to the shortage of bone mass and the lack of initial stability. Although studies have shown that intermittent teriparatide administration can promote osseointegration, there is little data to support the idea that pre-implantation administration is necessary and beneficial.

METHODS

Sixty-four titanium implants were placed in the bilateral proximal tibial metaphysis in 32 female SD rats. Bilateral ovariectomy (OVX) was used to induce osteoporosis. Four major groups (n = 8) were created: PRE (OVX + pre-implantation teriparatide administration), POST (OVX + post-implantation administration), OP (OVX + normal saline (NS)) and SHAM (sham rats + NS). Half of rats (n = 4) in each group were euthanized respectively at 4 weeks or 8 weeks after implantation surgery, and four major groups were divided into eight subgroups (PRE4 to SHAM8). Tibiae were collected for micro-CT morphometry, biomechanical test and undecalcified sections analysis.

RESULTS

Compared to OP group, rats in PRE and SHAM groups had a higher value of insertion torque (p < 0.05). The micro-CT analysis, biomechanical test, and histological data showed that peri-implant trabecular growth, implants fixation and bone-implant contact (BIC) were increased after 4 or 8 weeks of teriparatide treatment (p < 0.05). There was no statistically difference in those parameters between PRE4 and POST8 subgroups (p > 0.05).

CONCLUSIONS

In osteoporotic rats, post-implantation administration of teriparatide enhanced peri-implant bone formation and this effect was stronger as the medicine was taken longer. Pre-implantation teriparatide treatment improved primary implant stability and accelerated the osseointegration process.

Positive relation between dietary inflammatory index and osteoporosis in postmenopausal women

Background: Previous studies have shown that some dietary components may be implicated in the aetiology of postmenopausal osteoporosis. Objective: We examined the relationship between Dietary Inflammatory Index (DII®) and osteoporosis in postmenopausal women. Study design: Eight hundred and fifty postmenopausal women aged 50-65 years were randomly selected from 87 health care centers. Bone mineral density (BMD) was measured using the anterior-posterior lumbar spine (L1-L4) and proximal femur neck through Hologic QDR 4500W (S/N 50266) dual-energy X-ray absorptiometry device. After checking inclusion and exclusion criteria and diagnosis of osteoporosis, 124 women with normal bone mineral density (normal-BMD) and 108 women with osteoporosis were selected. Demographic, anthropometric, physical activity, midwifery, and dietary intake questionnaires were completed. DII was calculated based on a valid and reliable 168-item semi-quantitative food frequency questionnaire using 37 (out of 45) food parameters. A Logistic regression model adjusted for confounders was applied to estimate osteoporosis's odds ratio (OR) based on modeling DII as a continuous and dichotomous variable. Results: In this study, DII scores ranged from -3.71 (the most anti-inflammatory score) to +4.16 (the most pro-inflammatory score). The median DII value among the osteoporosis group was 0.97, among the normal group it was -0.31, indicating a more pro-inflammatory diet for osteoporosis. There were positive associations between osteoporosis and DII based on both continuous (Adjusted OR=3.467, 95% confidence interval (CI): 2.280-5.272, P-value<0.001) and dichotomous (Adjusted OR: DII ≤-0.31 / >-0.31=0.248, 95% CI: 0.110-0.561, P-value=0.001) measures in modeling adjusted for age, BMI, post-menopausal years, parity, education, total energy intake, and physical activity. Conclusions: These data suggest a pro-inflammatory diet, as indicated by increasing the DII score, may be a risk factor for osteoporosis in postmenopausal Iranian women.

Association of neutrophil to lymphocyte ratio with bone mineral density in post-menopausal women: a systematic review and meta-analysis

BACKGROUND

We conducted a systematic review and meta-analysis to compare the neutrophil lymphocyte ratio (NLR) levels between women with post-menopausal osteopenia or osteoporosis to those with normal bone mineral density (BMD).

METHODS

We used Web of Science, PubMed, and Scopus to conduct a systematic search for relevant publications published before June 19, 2022, only in English language. We reported standardized mean difference (SMD) with a 95% confidence interval (CI). Because a significant level of heterogeneity was found, we used the random-effects model to calculate pooled effects. We used the Newcastle-Ottawa scale for quality assessment.

RESULTS

Overall, eight articles were included in the analysis. Post-menopausal women with osteoporosis had elevated levels of NLR compared to those without osteoporosis (SMD = 1.03, 95% CI = 0.18 to 1.88, p = 0.017, I2 = 98%). In addition, there was no difference between post-menopausal women with osteopenia and those without osteopenia in neutrophil lymphocyte ratio (NLR) levels (SMD = 0.58, 95% CI=-0.08 to 1.25, p = 0.085, I2 = 96.8%). However, there was no difference between post-menopausal women with osteoporosis and those with osteopenia in NLR levels (SMD = 0.75, 95% CI=-0.01 to 1.51, p = 0.05, I2 = 97.5%, random-effect model).

CONCLUSION

The results of this study point to NLR as a potential biomarker that may be easily introduced into clinical settings to help predict and prevent post-menopausal osteoporosis.

Advances in the research on myokine-driven regulation of bone metabolism

The traditional view posits that bones and muscles interact primarily through mechanical coupling. However, recent studies have revealed that myokines, proteins secreted by skeletal muscle cells, play a crucial role in the regulation of bone metabolism. Myokines are widely involved in bone metabolism, influencing bone resorption and formation by interacting with factors related to bone cell secretion or influencing bone metabolic pathways. Here, we review the research progress on the myokine regulation of bone metabolism, discuss the mechanism of myokine regulation of bone metabolism, explore the pathophysiological relationship between sarcopenia and osteoporosis, and provide future perspectives on myokine research, with the aim of identify potential specific diagnostic markers and therapeutic entry points.

Wnt10b regulates osteogenesis of adipose-derived stem cells through Wnt/β-catenin signalling pathway in osteoporosis

Our previous finding revealed that the Wnt10b RNA expression of osteoporotic adipose-derived stem cells (OP-ASCs) with impaired osteogenic capacity was significantly reduced than that of ASCs. There are no ideas that the relationship between the OP-ASCs' impaired osteogenic potential and Wnt10b expression. This study aimed to indicate the potential molecular mechanisms and functional role of Wnt10b in OP-ASCs, as well as to investigate a potential application to reverse the OP-ASCs' impaired osteogenic differentiation potential. The OP-ASCs and ASCs were harvested from the inguinal fat of osteoporosis (OP) mice with bilateral ovariectomy (OVX) and normal mice. qPCR and WB were used to detect the different levels of the expression of the Wnt10b RNA in both OP-ASCs and ASCs. Lentiviral-mediated regulation of Wnt10b expression was employed for OP-ASCs, and the detection of the expression levels of key molecules in the Wnt signalling pathway and key osteogenic factors was performed through qPCR and WB in vitro experiments. The capacity of OP-ASCs to osteogenesis was determined using alizarin red staining. Lastly, the repair effect of the BCP scaffolds incorporating modified OP-ASCs on the critical-sized calvarial defects (CSCDs) in OP mice was scanned and detected by micro-computed tomography, haematoxylin and eosin staining, Masson's trichrome staining and immunohistochemistry. First, we discovered that both the RNA and protein expression levels of Wnt10b were significantly lower in OP-ASCs than that in ASCs. In vitro experiments, upregulation of Wnt10b could activate the Wnt signalling pathway, and increase expression of β-catenin, Lef1, Runx2 and osteopontin (Opn), thereby enhancing the osteogenic ability of OP-ASCs. In addition, the OP-ASCs with Wnt10b-overexpressing could promote the repair of CSCD in osteoporotic mice with increasing new bone volume, bone mineral density, and increased expression of Opn in new bone in vivo. Taken together, overexpression of Wnt10b could partially facilitate the differentiation of OP-ASCs towards osteogenesis and accelerated the healing of bone defects by activating the Wnt/β-catenin signalling pathway in vitro and in vivo experiments. This study confirmed the important role of Wnt10b in regulating the osteogenic differentiation capability of OP-ASCs and indicated Wnt10b could be a potential therapeutic target for reversing the impaired osteogenic capabilities of OP-ASCs to therapy bone defects of OP patients.

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.

Analyzing Sex-Specific Dimorphism in Human Skeletal Stem Cells

Sex-related differences are a current topic in contemporary science. In addition to hormonal regulation, cell-autonomous mechanisms are important in bone homeostasis and regeneration. In this study, human skeletal stem cells (SSCs) from female and male adults were cultured and analyzed with immunological assays and osteogenic differentiation assessments. Female SSCs exhibited a mean doubling time of 100.6 h, whereas male SSCs displayed a mean doubling time of 168.0 h. Immunophenotyping revealed the expression of the stem cell markers Nestin, CD133, and CD164, accompanied by the neural-crest marker SOX9. Furthermore, multiparameter flow cytometric analyses revealed a substantial population of multipotent SSCs, comprising up to 80% in both sexes. An analysis of the osteogenic differentiation potential demonstrated a strong mineralization in both male and female SSCs under physiological conditions. Recognizing the prevailing association of bone diseases with inflammatory processes, we also analyzed the osteogenic potential of SSCs from both sexes under pro-inflammatory conditions. Upon TNF-α and IL-1β treatment, we observed no sexual dimorphism on osteogenesis. In summary, we demonstrated the successful isolation and characterization of SSCs capable of rapid osteogenic differentiation. Taken together, in vitro cultured SSCs might be a suitable model to study sexual dimorphisms and develop drugs for degenerative bone diseases.

Roles of the Siglec family in bone and bone homeostasis

Tremendous progress has been seen in the study of the role of sialic acid binding im-munoglobulin type lectins (Siglecs) in osteoimmunology in the past two decades. Interest in Siglecs as immune checkpoints has grown from the recognition that Siglecs have relevance to human disease. Siglecs play important roles in inflammation and cancer, and play key roles in immune cell signaling. By recognizing common sialic acid containing glycans on glycoproteins and glycolipids as regulatory receptors for immune cell signals, Siglecs are expressed on most immune cells and play important roles in normal homeostasis and self-tolerance. In this review, we describe the role that the siglec family plays in bone and bone homeostasis, including the regulation of osteoclast differentiation as well as recent advances in inflammation, cancer and osteoporosis. Particular emphasis is placed on the relevant functions of Siglecs in self-tolerance and as pattern recognition receptors in immune responses, thereby potentially providing emerging strategies for the treatment of bone related diseases.

Eicosapentaenoic acid supplementation modulates the osteoblast/osteoclast balance in inflammatory environments and protects against estrogen deficiency-induced bone loss in mice

BACKGROUND

An imbalance of osteoblasts (OBs) and osteoclasts (OCs) in a chronic inflammatory microenvironment is an important pathological factor leading to osteoporosis. Eicosapentaenoic acid (EPA) has been shown to suppress inflammation in macrophages and adipocytes. However, the effect of EPA on OBs and OCs has yet to be fully elucidated.

AIMS

We explored the roles of EPA in the differentiation of OBs and OCs, as well as the coupling between OBs and OCs in an inflammatory microenvironment. The effects of EPA on estrogen deficiency-induced osteoporosis were also evaluated.

METHODS

Mouse bone marrow mesenchymal stem cells (mBMSCs) and mouse bone marrow-derived macrophages (mBMMs) were used for in vitro OBs and OCs differentiation. TNF-α was used to create an inflammatory microenvironment. We examined the effects of EPA on osteoblastogenesis in the absence or presence of TNF-α and collect OBs' culture medium as the conditioned medium (CM). Then we examined the effects of EPA and CM on RANKL-induced osteoclastogenesis. The in vivo effects of EPA were determined using an ovariectomized (OVX) mouse model treated with EPA or vehicle.

RESULTS

High-dose EPA was shown to promote osteoblastogenesis in an inflammatory environment in vitro, as well as upregulate expression of OBs-specific proteins and genes. ARS and ALP staining also showed that high-dose EPA-treated groups restored mBMSCs' impaired osteogenic capacity caused by TNFa. Mechanistically, EPA suppressed the NF-κB pathway activated by TNF-α in mBMSCs and rescued TNF-α-mediated inhibition of osteoblastogenesis. EPA was also shown to inhibit expression of RANKL and decrease the RANKL/OPG ratio in OBs in an inflammatory environment. CM from TNF-α-stimulated OBs promoted osteoclastogenesis of mBMMs; EPA-treated CM prevented this. In the OVX mouse model, EPA supplementation prevented bone loss in an estrogen deficiency-induced inflammatory environment.

CONCLUSIONS

EPA was demonstrated for the first time to restore mBMSCs' impaired osteogenic capacity caused by TNFa-induced inflammation and rescue the OBs/OCs balance via regulation of RANKL and OPG expression in OBs. EPA showed a remarkable ability to prevent bone loss in OVX mice, suggesting a potential application of EPA in postmenopausal osteoporosis.

Association Between the Dietary Inflammatory Index and the Risk of Fracture in Chinese Adults: Longitudinal Study

BACKGROUND

Chronic inflammation plays a crucial role in tissue injury, osteoporosis, and fracture. The dietary inflammatory index (DII) is a tool for assessing the potential for inflammation in the diet. However, the association between the DII and fractures remains controversial from previous studies.

OBJECTIVE

We aimed to explore the correlation between the DII and fracture risk in Chinese adults.

METHODS

We included 11,999 adults (5519 men and 6480 women) who were a part of the China Health and Nutrition Survey (1997-2015) prospective cohort. A 3-day, 24-hour meal review method was used to calculate the DII score. The fractures were identified using a questionnaire. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% CIs for fractures. Subgroup, sensitivity, and restricted cubic spline analyses were performed.

RESULTS

During the 18 years of follow-up (median follow-up 9.0 years), 463 men and 439 women developed fractures. The median DII score was 0.64 (IQR -1.74 to 1.46) for the total sample, 0.75 (IQR -1.68 to 1.50) for men, and 0.53 (IQR -1.79 to 1.42) for women. The DII score had a positive correlation with the risk of fracture among women but not among men. For men, after adjusting for covariates, the HRs for quintiles of DII were 1, 0.96 (95% CI 0.66-1.41), 1.05 (95% CI 0.74-1.49), 0.89 (95% CI 0.62-1.26), and 0.94 (95% CI 0.67-1.34; trend: P=.62). The HRs for women were 1, 1.13 (95% CI 0.72-1.79), 1.24 (95% CI 0.83-1.86), 1.51 (95% CI 1.02-2.22), and 1.62 (95% CI 1.10-2.39; trend: P=.004). The restricted cubic spline analysis showed a significant association between fracture risk and DII score in women (overall association: P=.01); as the DII scores were >0.53, HRs showed a significant upward trend. Women aged <50 years or who are nonsmokers, who are nondrinkers, or with nonabdominal obesity had a positive association between fracture risk and the DII score. In sensitivity analyses, after excluding people with diabetes or hypertension, there was still a positive association between fracture risk and the DII score in women. Among the DII components, the DII scores of protein (trend: P=.03), niacin (trend: P=.002), and iron (trend: P=.02) showed significant associations with the risk of fracture in women.

CONCLUSIONS

Proinflammatory diet consumption increased the fracture risk in Chinese women aged <50 years. The high consumption of anti-inflammatory foods and low consumption of proinflammatory foods may be an important strategy to prevent fractures in women.

The development, incidence and treatment trends of trochanteric fractures in Germany: a cohort study

BACKGROUND

Hip fractures are a major public health problem worldwide and can lead to disability, increased mortality, and reduced quality of life. We aim to provide a nationwide epidemiological analysis of trochanteric and subtrochanteric fractures and their respective surgical treatments.

METHODS

Data were retrieved from the national database of the German Department of the Interior. ICD-10-GM and OPS data from the period of 2006 to 2020 were analysed and all patients with trochanteric and subtrochanteric fractures as their main diagnosis, who were treated in a German hospital, were included. Patients were grouped by age and gender and linear regression was performed where suitable to calculate statistically significant correlations between variables and incidences.

RESULTS

985,104 pertrochanteric fractures and 178,810 subtrochanteric fractures were reported during the analysed period. We calculated a mean incidence of 80.08 ± 6.34 for pertrochanteric and 14.53 ± 1.50 for subtrochanteric fractures per million inhabitants. In both fracture types, a distinct dependence of incidence on age can be determined. Incidence rates equally rise in both sexes through the age groups with an increase of about 288-fold from those under the age of 60 to those over the age of 90 in pertrochanteric fractures, and about 123-fold in subtrochanteric fractures. Intramedullary nailing was the most common kind of treatment for both fracture types with augmentative cerclages on the rise throughout the whole period. Plate and dynamic compression screws were decreasing in frequency over the analysed period in both fractures.

CONCLUSIONS

We provided incidence data on per- and subtrochanteric fractures and their treatment. We calculated an economic impact of approximately 1.563 billion € per year in Germany. With regards to recent literature on costs of treatment and our findings regarding the implementation and utilization of different treatment methods, we conclude that the reinforcement of nationwide prevention programs is a relevant step in lessening the economic burden. We welcome the increased utilisation of intramedullary nailing as many studies show beneficiary outcomes and cost effectiveness in most of the included fracture types.

Vitamin D receptor gene polymorphisms influence on clinical profile and bone mineral density at different skeletal sites in postmenopausal osteoporotic women

Bone remodeling is marked by bone synthesis and absorption balance, and any altered dynamic in this process leads to osteoporosis (OP). The interaction of hormonal, environmental and genetic factors regulate bone metabolism. Since vitamin D displays a classic role in bone metabolism regulation, acting through vitamin D receptor (VDR), the genetic variants within VDR were the first ones associated with bone density and remodelling. Therefore, we investigated whether three single nucleotide polymorphisms (SNPs) within VDR were associated with OP differential susceptibility and clinical profile from postmenopausal versus healthy women from Northeast Brazil. Genetic association study enrolling 146 postmenopausal osteoporotic women as the patient group and 95 healthy age-matched women as the control group. We assessed three SNPs within VDR (rs11168268, rs1540339 and rs3890733), considering the clinical profile of all patients. Our results showed an association of rs11168268 G/G genotype with higher bone mineral density (BMD) mean for the total hip (A/A = 0.828 ± 0.09; A/G = 0.081 ± 0.13; G/G = 0.876 ± 0.12, p = .039), and the rs3890733 T/T genotype was associated with increased OP risk in patients below 60 years old (odds ratio [OR] = 5.12, 95% confidence interval [CI ]= 1.13-23.27, p = .012). The rs1540339 T/T genotype was associated with protection for individuals with low melanin deposition when compared to the high melanin deposition group (OR = 0.24, 95%CI = 0.06-0.94, p = .029). Additionally, 61% of patients presented deficient vitamin D serum levels. The SNP rs11168268 G/G was associated with a significantly increased mean total hip BMD in patients OP, highlighting this SNP and its relationship with BMD.

Circulating IGFBP-3 and Interleukin 6 as Predictors of Osteoporosis in Postmenopausal Women: A Cross-Sectional Study

Objective. To explore the relationship between circulating IGFBP-3, IL-6, and bone mineral density and the potential diagnostic role of circulating IGFBP-3 and IL-6 in postmenopausal women with osteoporosis. Methods. Eighty-five postmenopausal women at Soochow University’s First Affiliated Hospital, Osteoporosis and Menopause Clinics, were recruited. Forty-five of 85 women were diagnosed with osteoporosis. Circulating IL-6, PTH, 1,25(OH)2D3, osteocalcin (OST), IGF-1, IGFBP-3, and bone mineral density (BMD) of the lumbar spine (LS) and femoral neck (FN) were measured in 40 ordinary and 45 osteoporotic women. A simple regression analysis calculated the correlation between age, BMD, IL-6, and IGFBP-3. Multiple stepwise regression analyses were conducted to determine which variables were independently related to BMD. The potential role of IGFBP-3 and IL-6 in the diagnosis of postmenopausal osteoporosis was predicted using the area under the receiver operating characteristic curve (ROC, AUC). Results. Age, years since menopause, and circulating IL-6, PTH, and IGFBP-3 were significantly higher in the osteoporosis group compared to the normal group. Osteoporotic women had substantially lower BMDs of the LS and FN than normal women. Age-related increases were found for IGFBP-3 and IL-6, whereas age-related decreases were observed for LS/FN BMD. IGFBP-3 and IL-6 were both negatively correlated with LS and FN BMD. Stepwise multiple regression analysis showed that IGFBP-3 and IL-6 were strong predictors of BMD in postmenopausal women. AUC cut-off values (IGFBP-3: 3.65, IL-6: 0.205) were best evaluated for the diagnosis of postmenopausal women with osteoporosis, and the AUC for circulating IGFBP-3 and IL-6 were 0.706 (95% CI 0.594–0.818) and 0.685 (95% CI 0.571–0.798), respectively. Conclusion. In this cross-sectional study of postmenopausal women, IGFBP-3 and IL-6 were negatively related to BMD. Circulating IGFBP-3 and IL-6 might be essential predictors of postmenopausal osteoporosis and can help predict osteoporotic fracture.

Daytime administration of melatonin has better protective effects on bone loss in ovariectomized rats

OBJECTIVE

To explore the difference in the protective effects of intraperitoneal injection of exogenous melatonin of daytime or nighttime on bone loss in ovariectomized (OVX) rats.

METHODS

After bilateral ovariectomy and sham surgery, 40 rats were randomly divided into four groups: sham operation group (Sham), ovariectomy (OVX), and daytime melatonin injection group (OVX + DMLT, 9:00, 30 mg/kg/d) and nighttime injection of melatonin (OVX + NMLT, 22:00, 30 mg/kg/d). After 12 weeks of treatment, the rats were sacrificed. The distal femur, blood and femoral marrow cavity contents were saved. The rest of the samples were tested by Micro-CT, histology, biomechanics and molecular biology. Blood was used for bone metabolism marker measurements. CCK-8, ROS, and Cell apoptosis are performed using MC3E3-T1 cells.

RESULTS

Compared with treatment at night, the bone mass of the OVX rats was significantly increased after the daytime administration. All microscopic parameters of trabecular bone increased, only Tb.Sp decreased. Histologically, the bone microarchitecture of the OVX + DMLT was also more dense than the bone microarchitecture of the OVX + LMLT. In the biomechanical experiment, the femur samples of the day treatment group were able to withstand greater loads and deformation. In molecular biology experiments, bone formation-related molecules increased, while bone resorption-related molecules decreased. After treatment with melatonin administration at night, the expression of MT-1β was significantly decreased. In cell experiments, the MC3E3-T1 cells treated with low-dose MLT had higher cell viability and greater efficiency in inhibiting ROS production than the MC3E3-T1 cells treated with high-dose MLT, which in turn more effectively inhibited apoptosis.

CONCLUSION

Daytime administration of melatonin acquires better protective effects on bone loss than night in OVX rats.

IL-1 Mediates Chronic Stress-Induced Hyperalgesia Accompanied by Microglia and Astroglia Morphological Changes in Pain-Related Brain Regions in Mice

Chronic stress causes several pain conditions including fibromyalgia. Its pathophysiological mechanisms are unknown, and the therapy is unresolved. Since the involvement of interleukin-1 (IL-1) has been described in stress and inflammatory pain but no data are available regarding stress-induced pain, we studied its role in a chronic restraint stress (CRS) mouse model. Female and male C57Bl/6J wild-type (WT) and IL-1αβ-deficient (knock-out: IL-1 KO) mice were exposed to 6 h of immobilization/day for 4 weeks. Mechanonociception, cold tolerance, behavioral alterations, relative thymus/adrenal gland weights, microglia ionized calcium-binding adaptor molecule 1 (IBA1) and astrocyte glial fibrillary acidic protein (GFAP) integrated density, number and morphological transformation in pain-related brain regions were determined. CRS induced 15–20% mechanical hyperalgesia after 2 weeks in WT mice in both sexes, which was significantly reduced in female but not in male IL-1 KOs. Increased IBA1+ integrated density in the central nucleus of amygdala, primary somatosensory cortex hind limb representation part, hippocampus cornu ammonis area 3 (CA3) and periaqueductal gray matter (PAG) was present, accompanied by a cell number increase in IBA1+ microglia in stressed female WTs but not in IL-1 KOs. CRS induced morphological changes of GFAP+ astrocytes in WT but not in KO mice. Stress evoked cold hypersensitivity in the stressed animals. Anxiety and depression-like behaviors, thymus and adrenal gland weight changes were detectable in all groups after 2 but not 4 weeks of CRS due to adaptation. Thus, IL-1 mediates chronic stress-induced hyperalgesia in female mice, without other major behavioral alterations, suggesting the analgesic potentials of IL-1 in blocking drugs in stress-related pain syndromes.

Associations Between Inflammatory Mediators and Bone Outcomes in Postmenopausal Women: A Cross-Sectional Analysis of Baseline Data from the Prune Study

Purpose

Hypoestrogenism triggers increased production of inflammatory mediators, which contribute to bone loss during postmenopausal osteoporosis. This study aimed to investigate the association between circulating inflammatory markers and bone outcomes in postmenopausal women.

Materials and methods

We conducted a cross-sectional, secondary analysis of baseline data from participants who completed a 12-month randomized controlled trial, The Prune Study (NCT02822378), which included healthy postmenopausal women (n=183, 55-75 years old) with bone mineral density (BMD) T-score between 0.0 and -3.0 at any site. BMD was measured using dual-energy X-ray absorptiometry, and bone geometry and strength were measured using peripheral quantitative computed tomography. Blood was collected at baseline to measure (1) serum biomarkers of bone turnover, including procollagen type 1 N-terminal propeptide (P1NP) and C-terminal telopeptide and (2) inflammatory markers, including serum high-sensitivity C-reactive protein (hs-CRP) and plasma pro-inflammatory cytokines, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-8, and monocyte chemoattractant protein (MCP)-1, using enzyme-linked immunosorbent assay. The associations between bone and inflammatory outcomes at baseline were analyzed using correlation and regression analyses.

Results

Serum hs-CRP negatively correlated with P1NP (r=-0.197, p=0.042). Plasma IL-1β, IL-6, IL-8, and TNF-α negatively correlated with trabecular bone score at the lumbar spine (all p<0.05). In normal-weight women, plasma IL-1β, IL-6, and IL-8 negatively correlated (p<0.05) with trabecular and cortical bone area, content, and density at various sites in the tibia and radius. Serum hs-CRP positively predicted lumbar spine BMD (β=0.078, p=0.028). Plasma IL-6 negatively predicted BMD at the total body (β=-0.131, p=0.027) and lumbar spine (β=-0.151, p=0.036), whereas plasma TNF-α negatively predicted total hip BMD (β=-0.114, p=0.028).

Conclusion

At baseline, inflammatory markers were inversely associated with various estimates of bone density, geometry, and strength in postmenopausal women. These findings suggest that inflammatory markers may be an important mediator for postmenopausal bone loss.

FAEE exerts a protective effect against osteoporosis by regulating the MAPK signalling pathway

CONTEXT

Ferulic acid ethyl ester (FAEE) is abundant in Ligusticum chuanxiong Hort. (Apiaceae) and grains, and possesses diverse biological activities; but the effects of FAEE on osteoporosis has not been reported.

OBJECTIVE

This study investigated whether FAEE can attenuate osteoclastogenesis and relieve ovariectomy-induced osteoporosis via attenuating mitogen-activated protein kinase (MAPK).

MATERIALS AND METHODS

We stimulated RAW 264.7 cells with receptor activator of NF-κB ligand (RANKL) followed by FAEE. The roles of FAEE in osteoclast production and osteogenic resorption of mature osteoclasts were evaluated by tartrate resistant acid phosphatase (TRAP) staining, expression of osteoclast-specific genes, proteins and MAPK. Ovariectomized (OVX) female Sprague-Dawley rats were administered FAEE (20 mg/kg/day) for 12 weeks to explore its potential in vivo, and then histology was undertaken in combination with cytokines analyses.

RESULTS

FAEE suppressed RANKL-induced osteoclast formation (96 ± 0.88 vs. 15 ± 1.68) by suppressing the expression of osteoclast-specific genes, proteins and MAPK signalling pathway related proteins (p-ERK/ERK, p-JNK/JNK and p-P38/P38) in vitro. In addition, OVX rats exposed to FAEE maintained their normal calcium (Ca) (2.72 ± 0.02 vs. 2.63 ± 0.03, p < 0.05) balance, increased oestradiol levels (498.3 ± 9.43 vs. 398.7 ± 22.06, p < 0.05), simultaneously reduced levels of bone mineral density (BMD) (0.159 ± 0.0016 vs. 0.153 ± 0.0025, p < 0.05) and bone mineral content (BMC) (0.8 ± 0.0158 vs. 0.68 ± 0.0291, p < 0.01).

DISCUSSION AND CONCLUSIONS

These findings suggested that FAEE could be used to ameliorate osteoporosis by the MAPK signalling pathway, suggesting that FAEE could be a potential therapeutic candidate for osteoporosis.

Systemic administration with melatonin in the daytime has a better effect on promoting osseointegration of titanium rods in ovariectomized rats

Aims

This study examined whether systemic administration of melatonin would have different effects on osseointegration in ovariectomized (OVX) rats, depending on whether this was administered during the day or night.

Methods

In this study, a titanium rod was implanted in the medullary cavity of one femoral metaphysis in OVX rats, and then the rats were randomly divided into four groups: Sham group (Sham, n = 10), OVX rat group (OVX, n = 10), melatonin day treatment group (OVX + MD, n = 10), and melatonin night treatment group (OVX + MN, n = 10). The OVX + MD and OVX + MN rats were treated with 30 mg/kg/day melatonin at 9 am and 9 pm, respectively, for 12 weeks. At the end of the research, the rats were killed to obtain bilateral femora and blood samples for evaluation.

Results

Micro-CT and histological evaluation showed that the bone microscopic parameters of femoral metaphysis trabecular bone and bone tissue around the titanium rod in the OVX + MD group demonstrated higher bone mineral density, bone volume fraction, trabecular number, connective density, trabecular thickness, and lower trabecular speculation (p = 0.004) than the OVX + MN group. Moreover, the biomechanical parameters of the OVX + MD group showed higher pull-out test and three-point bending test values, including fixation strength, interface stiffness, energy to failure, energy at break, ultimate load, and elastic modulus (p = 0.012) than the OVX + MN group. In addition, the bone metabolism index and oxidative stress indicators of the OVX + MD group show lower values of Type I collagen cross-linked C-telopeptide, procollagen type 1 N propeptide, and malondialdehyde (p = 0.013), and higher values of TAC and SOD (p = 0.002) compared with the OVX + MN group.

Conclusion

The results of our study suggest that systemic administration with melatonin at 9 am may improve the initial osseointegration of titanium rods under osteoporotic conditions more effectively than administration at 9 pm. Cite this article: Bone Joint Res 2022;11(11):751–762.

The Role of Prunes in Modulating Inflammatory Pathways to Improve Bone Health in Postmenopausal Women

The prevalence of osteoporosis among women aged 50 y and older is expected to reach 13.6 million by 2030. Alternative nonpharmaceutical agents for osteoporosis, including nutritional interventions, are becoming increasingly popular. Prunes (dried plums; Prunus domestica L.) have been studied as a potential whole-food dietary intervention to mitigate bone loss in preclinical models of osteoporosis and in osteopenic postmenopausal women. Sixteen preclinical studies using in vivo rodent models of osteopenia or osteoporosis have established that dietary supplementation with prunes confers osteoprotective effects both by preventing and reversing bone loss. Increasing evidence from 10 studies suggests that, in addition to antiresorptive effects, prunes exert anti-inflammatory and antioxidant effects. Ten preclinical studies have found that prunes and/or their polyphenol extracts decrease malondialdehyde and NO secretion, increase antioxidant enzyme expression, or suppress NF-κB activation and proinflammatory cytokine production. Two clinical trials have investigated the impact of dried plum consumption (50-100 g/d for 6-12 mo) on bone health in postmenopausal women and demonstrated promising effects on bone mineral density and bone biomarkers. However, less is known about the impact of prune consumption on oxidative stress and inflammatory mediators in humans and their possible role in modulating bone outcomes. In this review, the current state of knowledge on the relation between inflammation and bone health is outlined. Findings from preclinical and clinical studies that have assessed the effect of prunes on oxidative stress, inflammatory mediators, and bone outcomes are summarized, and evidence supporting a potential role of prunes in modulating inflammatory and immune pathways is highlighted. Key future directions to bridge the knowledge gap in the field are proposed.

Shilajit extract reduces oxidative stress, inflammation, and bone loss to dose-dependently preserve bone mineral density in postmenopausal women with osteopenia: A randomized, double-blind, placebo-controlled trial

BACKGROUND

Accelerated bone loss associated with aging and estrogen withdrawal is mediated in part by increased oxidative stress and inflammation.

OBJECTIVE

Investigate dietary supplementation with a standardized aqueous extract of shilajit with clinically demonstrated antioxidant, anti-inflammatory, and collagen-promoting activity on attenuating bone loss in postmenopausal women with osteopenia.

DESIGN

Sixty postmenopausal women aged 45 - 65 years with osteopenia were randomized to receive 1 of 3 treatments daily for 48 weeks: (1) placebo, (2) 250 mg shilajit extract, or (3) 500 mg shilajit extract. Bone mineral density (BMD) of the lumbar spine (LS) and femoral neck (FN) were measured at weeks 0, 24, and 48, and circulating markers of bone turnover (CTX-1, BALP, RANKL, OPG), oxidative stress (MDA, GSH), and inflammation (hsCRP) at weeks 0, 12, 24, and 48.

RESULTS

BMD of both the LS and FN progressively decreased in women receiving placebo but was dose-dependently attenuated with shilajit extract supplementation, resulting in significantly increased percentage changes from baseline in BMD at 24- and 48-weeks in both supplemented groups compared to placebo (p < 0.001). CTX-1, BALP, and RANKL decreased, whereas OPG increased, in both groups supplemented with the shilajit extract, but not in the placebo group, resulting in significantly decreased or increased percentage changes from baseline, respectively. MDA was significantly decreased (p < 0.001) and GSH was significantly increased (p < 0.001) in both supplemented groups compared to placebo from week 12 for the duration of the study. Progressive reductions in hsCRP were observed in both supplemented groups, resulting in significantly decreased percentage changes from baseline in supplemented women compared to placebo (p < 0.001).

CONCLUSION

Daily supplementation with this shilajit extract supports BMD in postmenopausal women with osteopenia in part by attenuating the increased bone turnover, inflammation and oxidative stress that coincides with estrogen deficiency in this population at increased risk for osteoporosis and bone fractures.

Impact of seborrheic dermatitis on osteoporosis risk: A population‐based cohort study

Osteoporosis is a systemic bone-resorbing disease that easily causes subsequent risk of fracture. Hence, the substantial physical burden of osteoporosis makes it an important public health issue. Seborrheic dermatitis (SD) is a chronic, recurrent, inflammatory skin disease. Despite the advances in medication for treating osteoporosis, identifying undiagnosed osteoporosis patients is still challenging. Since osteoporosis and SD share a similar pathobiology, e.g. inflammation and hormonal imbalance, we aimed to investigate whether the existence of SD increases osteoporosis risk by using the Taiwan National Health Insurance Research Database. A total of 7831 patients aged 18-50 years with SD and a control group of 31 324 patients without SD matched by age, gender, Charlson Comorbidity Index, and index date at a ratio of 1:4 during 1996-2010 were recruited in the study. To measure the cumulative incidence and compare the hazard ratios of osteoporosis between each group, the Kaplan-Meier method and Cox proportional hazard regression models were utilized. It was found that 0.98% of SD patients had osteoporosis. Compared to the non-SD group, the SD group had a 5.95-fold higher osteoporosis risk after adjustment for variables. The impact of SD on osteoporosis risk was largest in the female and young age groups. In addition, the presence of hyperlipidemia, hyperthyroidism, and epilepsy synergistically increased osteoporosis incidence in the SD group. This first large cohort study demonstrated an association between SD and osteoporosis. Since the effect on bone health in SD patients with concomitant diseases is largest in early life, diet or lifestyle recommendations as well as regular bone examinations are advised during follow-up of SD.

Exercise for osteoporosis: A literature review of pathology and mechanism

Osteoporosis (OP) is a disease that weakens bones and has a high morbidity rate worldwide, which is prevalent among the elderly, particularly, women of postmenopausal age. The dynamic balance between bone formation and resorption is necessary for normal bone metabolism. Many factors, including aging, estrogen deficiency, and prolonged immobilization, disrupt normal apoptosis, autophagy, and inflammation, leading to abnormal activation of osteoclasts, which gradually overwhelm bone formation by bone resorption. Moderate exercise as an effective non-drug treatment helps increase bone formation and helps relieve OP. The possible mechanisms are that exercise affects apoptosis and autophagy through the release of exercise-stimulated myohormone and the secretion of anti-inflammatory cytokines via mechanical force. In addition, exercise may also have an impact on the epigenetic processes involved in bone metabolism. Mechanical stimulation promotes bone marrow mesenchymal stem cells (BMSCs) to osteogenic differentiation by altering the expression of non-coding RNAs. Besides, by reducing DNA methylation, the mechanical stimulus can also alter the epigenetic status of osteogenic genes and show associated increased expression. In this review, we reviewed the possible pathological mechanisms of OP and summarized the effects of exercise on bone metabolism, and the mechanisms by which exercise alleviates the progression of OP, to provide a reference for the prevention and treatment of OP.

The role of metabolites under the influence of genes and lifestyles in bone density changes

Purpose

Osteoporosis is a complex bone disease influenced by numerous factors. Previous studies have found that some metabolites are related to bone mineral density (BMD). However, the associations between metabolites and BMD under the influence of genes and lifestyle have not been fully investigated.

Methods

We analyzed the effect of metabolites on BMD under the synergistic effect of genes and lifestyle, using the data of 797 participants aged 55–65 years from the Taizhou Imaging Study. The cumulative sum method was used to calculate the polygenic risk score of SNPs, and the healthful plant-based diet index was used to summarize food intake. The effect of metabolites on BMD changes under the influence of genes and lifestyle was analyzed through interaction analysis and mediation analysis.

Results

Nineteen metabolites were found significantly different in the osteoporosis, osteopenia, and normal BMD groups. We found two high-density lipoprotein (HDL) subfractions were positively associated with osteopenia, and six very-low-density lipoprotein subfractions were negatively associated with osteopenia or osteoporosis, after adjusting for lifestyles and genetic factors. Tea drinking habits, alcohol consumption, smoking, and polygenic risk score changed BMD by affecting metabolites.

Conclusion

With the increased level of HDL subfractions, the risk of bone loss in the population will increase; the risk of bone loss decreases with the increased level of very-low-density lipoprotein subfractions. Genetic factors and lifestyles can modify the effects of metabolites on BMD. Our results show evidence for the precise prevention of osteoporosis.

The Effects of Er Xian Decoction Combined with Baduanjin Exercise on Bone Mineral Density, Lower Limb Balance Function, and Mental Health in Women with Postmenopausal Osteoporosis: A Randomized Controlled Trial

Background

Postmenopausal osteoporosis (PMOP) is a common disease in older women that can severely jeopardize their health. Previous studies have demonstrated the effect of Er xian decoction (EXD) or Baduanjin exercise (BE) on PMOP. However, reports on the effect of EXD combined with BE on PMOP are limited. This study aimed to investigate the impact of EXD combined with BE on bone mineral density (BMD), lower limb balance, and mental health in women with PMOP.

Methods

A 1 : 1 : 1 simple randomization technique was employed. Fifty participants with postmenopausal osteoporosis were allocated to three groups: the EXD group (EXD = 15); the BE group (BE = 18); and the combined group (EXD + BE = 17). After both 8 weeks and 16 weeks of intervention treatment, participants improved significantly with respect to BMD and the one-leg standing test (OLST), Berg balance scale (BBS), timed up and go (TUG) test, self-anxiety scale (SAS), and self-rating depression scale (SDS). The results were used to compare the effect of the intervention on BMD, lower limb balance function, and mental health in patients with PMOP.

Results

Compared to the EXD and BE groups, the EXD + BE group showed the strongest effects on BMD, lower limb balance function, and mental health (p < 0.01). A correlation between BMD and lower limb balance and mental health was noted in the EXD + BE group. The change in mental health (SAS score) was correlated with BMD (femoral neck) improvement.

Conclusions

The present study demonstrates that EXD combined with BE (EXD + BE) may have a therapeutic advantage over both monotherapies for treating BMD, lower limb balance function, and mental health in patients with PMOP. The feasibility of the approach for a large-scale RCT was also confirmed. Er xian decoction combined with Baduanjin exercise (EXD + BE) might offer a viable treatment alternative for participants with postmenopausal osteoporosis given its promising effects in disease control and treatment, with good efficacy and safety profiles.

High-mobility group box chromosomal protein-1 deletion alleviates osteoporosis in OVX rat model via suppressing the osteoclastogenesis and inflammation

Background

Osteoporosis is a skeletal metabolic disease that constitutes a great threaten to human health. However, there is currently no gold standard for its treatment. High-mobility group box chromosomal protein-1 (HMGB-1) has been reported to play an important role in various orthopedic diseases. Till now, its role in osteoporosis remains elusive.

Methods

Rats underwent ovariectomy (OVX) were used to construct a postmenopausal model of osteoporosis. Then, rats were divided into sham groups without OVX surgery, OVX model group, HMGB-1 knockdown (HMGB-1 KD) OVX model groups. The expression of HMGB1 was evaluated by qRT-PCR and western blotting. Subsequently, the changes of trabeculae were evaluated by micro-computed tomography (CT) assay. Skeletal necrosis and metabolism were further analyzed by hematoxylin–eosin (HE) staining, Alcian blue staining and Masson’s trichrome staining. The contents of serum alkaline phosphatase (ALP) and osteocalcin were detected by ELISA assay. Expression of osteoclast-associated receptor (OSCAR) and tartrate-resistant acid phosphatase (TRAP) were determined to investigate the effects of HMGB-1 loss on osteoclastogenesis.

Results

Single HMGB-1 deletion exerted no significant effect on rat trabeculae, serum ALP and osteocalcin. Noticeably, HMGB1 knockdown dramatically ameliorated OVX-induced changes in above indexes. Trabeculae structures of OVX rats were sparse with disorder arrangement, which were greatly recovered after HMGB-1 deletion. Enhanced osteoclastogenesis was observed in OVX rats by increasing number of TRAP + cells and expression of TRAP and OSCAR, and loss of HMGB1 ameliorated osteoclastogenesis in OVA rats. Moreover, HMGB-1 deletion antagonized OVX-evoked downregulation of osteoblast activity markers osterix (OSX), collagen type I alpha 1(COL1A1) and distal-less homeobox 2 (DLX2) protein. Furthermore, loss of HMGB-1 attenuated fluctuation of inflammatory factors in OVX rats. Additionally, HMGB-1 deficiency inhibited OVX-evoked activation of the Toll-like receptor (TLR) 4/NF-κB signaling pathway. Moreover, reactivating the TLR4 signaling further aggravated OVX-induced osteoporosis, which was reversed by HMGB1 knockdown.

Conclusion

HMGB-1 deletion alleviated OVX-triggered osteoporosis by suppressing osteoclastogenesis and inflammatory disorder via the inhibition of the TLR4 signaling. Therefore, HMGB-1 may be a promising therapeutic target for osteoporosis.

Sex differences in systemic bone and muscle loss following femur fracture in mice

Fracture induces systemic bone loss in mice and humans, and a first (index) fracture increases the risk of future fracture at any skeletal site more in men than women. The etiology of this sex difference is unknown, but fracture may induces a greater systemic bone loss response in men. Also sex differences in systemic muscle loss after fracture have not been examined. We investigated sex differences in systemic bone and muscle loss after transverse femur fracture in 3-month-old male and female C57BL/6 J mice. Whole-body and regional bone mineral content and density (BMC and BMD), trabecular and cortical bone microstructure, muscle contractile force, muscle mass, and muscle fiber size were quantified at multiple time points postfracture. Serum concentrations of inflammatory cytokines (IL-1β, IL-6, and TNF-α) were measured 1-day postfracture. One day postfracture, IL-6 and Il-1B were elevated in fracture mice of both sexes, but TNF-α was only elevated in male fracture mice. Fracture reduced BMC, BMD, and trabecular bone microstructural properties in both sexes 2 weeks postfracture, but declines were greater in males. Muscle contractile force, mass, and fiber size decreased primarily in the fractured limb at 2 weeks postfracture and females showed a trend toward greater muscle loss. Bone and muscle properties recovered by 6 weeks postfracture. Overall, postfracture systemic bone loss is greater in men, which may contribute to sex differences in subsequent fracture risk. In both sexes, muscle loss is primarily confined to the injured limb and fracture may induce greater inflammation in males.

Osteoporosis and periodontal diseases - An update on their association and mechanistic links

Periodontitis and osteoporosis are prevalent inflammation-associated skeletal disorders that pose significant public health challenges to our aging population. Both periodontitis and osteoporosis are bone disorders closely associated with inflammation and aging. There has been consistent intrigue on whether a systemic skeletal disease such as osteoporosis will amplify the alveolar bone loss in periodontitis. A survey of the literature published in the past 25 years indicates that systemic low bone mineral density (BMD) is associated with alveolar bone loss, while recent evidence also suggests a correlation between clinical attachment loss and other parameters of periodontitis. Inflammation and its influence on bone remodeling play critical roles in the pathogenesis of both osteoporosis and periodontitis and could serve as the central mechanistic link between these disorders. Enhanced cytokine production and elevated inflammatory response exacerbate osteoclastic bone resorption while inhibiting osteoblastic bone formation, resulting in a net bone loss. With aging, accumulation of oxidative stress and cellular senescence drive the progression of osteoporosis and exacerbation of periodontitis. Vitamin D deficiency and smoking are shared risk factors and may mediate the connection between osteoporosis and periodontitis, through increasing oxidative stress and impairing host response to inflammation. With the connection between systemic and localized bone loss in mind, routine dental exams and intraoral radiographs may serve as a low-cost screening tool for low systemic BMD and increased fracture risk. Conversely, patients with fracture risk beyond the intervention threshold are at greater risk for developing severe periodontitis and undergo tooth loss. Various Food and Drug Administration-approved therapies for osteoporosis have shown promising results for treating periodontitis. Understanding the molecular mechanisms underlying their connection sheds light on potential therapeutic strategies that may facilitate co-management of systemic and localized bone loss.

Sialylation of TLR2 initiates osteoclast fusion

The molecular control of osteoclast formation is still not clearly elucidated. Here, we show that a process of cell recognition mediated by Siglec15-TLR2 binding is indispensable and occurs prior to cell fusion in RANKL-mediated osteoclastogenesis. Siglec15 has been shown to regulate osteoclastic bone resorption. However, the receptor for Siglec15 has not been identified, and the signaling mechanism involving Siglec15 in osteoclast function remains unclear. We found that Siglec15 bound sialylated TLR2 as its receptor and that the binding of sialylated TLR2 to Siglec15 in macrophages committed to the osteoclast-lineage initiated cell fusion for osteoclast formation, in which sialic acid was transferred by the sialyltransferase ST3Gal1. Interestingly, the expression of Siglec15 in macrophages was activated by M-CSF, whereas ST3Gal1 expression was induced by RANKL. Both Siglec15-specific deletion in macrophages and intrafemoral injection of sialidase abrogated cell recognition and reduced subsequent cell fusion for the formation of osteoclasts, resulting in increased bone formation in mice. Thus, our results reveal that cell recognition mediated by the binding of sialylated TLR2 to Siglec15 initiates cell fusion for osteoclast formation.

Androgens and estrogens predict sexual function after autologous hematopoietic stem cell transplant in men

BACKGROUND

Autologous hematopoietic stem cell transplantation (AHSCT) is associated with sexual dysfunction and hypogonadism. Androgens are associated with sexual function in healthy men, but the role of estrogens is less well-known, and the association of these sex steroids with sexual function during AHSCT has not been characterized.

OBJECTIVES

The purpose of this study was to determine the predictive value of sex hormones before and acutely after AHSCT on sexual function recovery.

MATERIALS AND METHODS

We examined sex hormones and self-reported sexual function before (PRE) and 1-month post-AHSCT (MONTH1; n = 19), and sexual function again 1-year post-AHSCT in men (YEAR1; n = 15).

RESULTS

Sexual function decreased from PRE to MONTH1 (p ≤ 0.05) with no differences between PRE and YEAR1. Erectile dysfunction was prevalent at PRE (68.4%) and increased at MONTH1 (100%; p ≤ 0.05) but was not different between PRE and YEAR1 (60.0%). From PRE to MONTH1, total testosterone (TT), dihydrotestosterone (DHT), follicle-stimulating hormone, and sex-hormone-binding globulin (SHBG) increased (p ≤ 0.02) while estradiol (p ≤ 0.026) and estrone decreased (p ≤ 0.001). MONTH1 TT and DHT were associated with sexual function at MONTH1, while PRE SHBG, MONTH1 estradiol, and change in estrone predicted sexual function at YEAR1.

DISCUSSION

Sexual dysfunction is very prevalent prior to AHSCT and is transiently and severely worsened acutely after. AHSCT induces acute decreases in total and free estrogens, with SHBG increases leading to increases in total androgens, without changes in free androgens.

CONCLUSION

Androgens and estrogens are both adversely affected by AHSCT but may predict sexual dysfunction in this population. This supports the premise that estrogen impacts sexual function independent from androgens and that steroid hormones are associated with acute changes in sexual function in this setting. Larger, controlled trials with long-term sex hormone assessment will need to confirm the association between early changes in estrogens and long-term sexual function recovery.

Lipoic acid (LA) dose-dependently protects bone losses in the mandible of rats during the development of osteopenia by inhibiting oxidative stress and promoting bone formation

Our study was carried out to evaluate the effect of lipoic acid (LA) on the densitometric properties, structure and mechanical strength of the mandible of Wistar rats with developing osteopenia. The study used 42 sham-operated (SHO) and ovariectomized (OVX) rats. The OVX rats were randomly divided (n = 6) onto two controls treated subcutaneously with physiological saline (OVX-PhS) and 17β-estradiol (OVX-E2), respectively, and onto four experimental OVX groups that received LA in the doses of 12.5, 25, 50 and 100 mg/kg/day for 28 days. The results demonstrated that the lack of estrogen brought about osteopenic bone changes, especially in the trabecular compartment. In addition, while the usage of LA in the doses of 12.5 and 25 LA had no effect in OVX rats, the dose of 100 effectively inhibited osteopenic changes of the mandible. This dose maintained structural, densitometric and mechanical parameters at levels like that in the SHO and OVX-E2 groups by inhibiting the destructive influence of oxidative stress. Dose 50, however, was revealed to be the most effective. It not only inhibited atrophic changes and the influence of oxidative stress, but also stimulated the formation of mandibular bone tissue. Our results suggest that the administration of LA is effective in preventing atrophic changes in the mandibular bone tissue in conditions of ovarian hormone deficiency and suggest its potential in the therapy of osteoporosis.

Impacts of Angelica Polysaccharide on Proliferation and Differentiation of Mesenchymal Stem Cells of Rat Bone Marrow

In literature, antiosteoporotic effects of Angelica sinensis root have been confirmed, but the impact of Angelica sinensis polysaccharide (ASP) on osteoblastic or adipogenic distinction of BMSCs is limited. This paper aimed to explore the role of ASP on proliferation and differentiation of rat BMSCs. Rat BMSCs were subjected to isolation and identification through flow cytometry. The proliferation of rat BMSCs under ASP was performed by CCK-8 kit. Measures of osteogenesis under different concentrations of ASP were detected by using alizarin red staining for mesenchymal cells differentiation and ALP activity assay to identify ALP activity. Quantitative RT-PCR was selected to identify osteoblastic or adipogenic biomarkers from a genetic perspective. Likewise, we have evaluated measures of indicators of Wnt/β-catenin signal. ASP significantly promoted the proliferation, increased osteogenesis, and decreased adipogenesis of rat BMSCs within the limit of 20-60 mg/L in a dose-dependent manner but was suppressed at 80 mg/L. The expression of cyclin D1 and ß-catenin showed a considerable rise over the course of ASP induced osteogenesis. Dickkopf 1 (DKK1) suppressed the regulation of rat BMSCs differentiation through the mediation of ASP. We have observed that ASP upregulated the osteogenic but downregulated adipogenic differentiation of BMSCs, and our findings help to contribute to effective solutions for treating bone disorders.

Gallic acid inhibits osteoclastogenesis and prevents ovariectomy-induced bone loss

Osteoporosis is a common metabolic bone disease with a rapidly increasing prevalence, characterized by massive bone loss because of excessive osteoclast formation. Gallic acid (GA), a phenolic acid isolated from Cornus officinalis, has anti-inflammatory and anti-oxidant effects, but its effect on osteoclast formation has not been confirmed. In our study, we demonstrated that GA significantly inhibited RANKL-induced osteoclast formation and function of osteoclast in bone marrow monocytes (BMMs) and RAW264.7 cells in a dose-dependent manner without cytotoxicity. For molecular mechanisms, GA repressed osteoclastogenesis by blocking Akt, ERK, and JNK pathways, and suppressed osteoclastogenesis-related marker expression, including nuclear factor of the activated T-cell cytoplasmic 1 (NFATc1), c-Fos, and cathepsin K (CTSK). In addition, we further assessed the effect of GA in an ovariectomized mouse model, which indicated that GA has a notable effect on preventing bone loss. In conclusion, GA exerts notable effects in inhibiting osteoclastogenesis and preventing ovariectomy-induced bone loss, suggesting that GA is a potential agent in osteoporosis treatment.

Roles of Altered Macrophages and Cytokines: Implications for Pathological Mechanisms of Postmenopausal Osteoporosis, Rheumatoid Arthritis, and Alzheimer's Disease

Postmenopausal osteoporosis (PMOP) is characterized by the uncoupling of bone resorption and bone formation induced by estrogen deficiency, which is a complex outcome related to estrogen and the immune system. The interaction between bone and immune cells is regarded as the context of PMOP. Macrophages act differently on bone cells, depending on their polarization profile and secreted paracrine factors, which may have implications for the development of PMOP. PMOP, rheumatoid arthritis (RA), and Alzheimer's disease (AD) might have pathophysiological links, and the similarity of their pathological mechanisms is partially visible in altered macrophages and cytokines in the immune system. This review focuses on exploring the pathological mechanisms of PMOP, RA, and AD through the roles of altered macrophages and cytokines secretion. First, the multiple effects on cytokines secretion by bone-bone marrow (BM) macrophages in the pathological mechanism of PMOP are reviewed. Then, based on the thought of "different tissue-same cell type-common pathological molecules-disease pathological links-drug targets" and the methodologies of "molecular network" in bioinformatics, highlight that multiple cytokines overlap in the pathological molecules associated with PMOP vs. RA and PMOP vs. AD, and propose that these overlaps may lead to a pathological synergy in PMOP, RA, and AD. It provides a novel strategy for understanding the pathogenesis of PMOP and potential drug targets for the treatment of PMOP.

Leucine rich amelogenin peptide prevents ovariectomy-induced bone loss in mice

Amelogenins, major extra cellular matrix proteins of developing tooth enamel, are predominantly expressed by ameloblasts and play significant roles in the formation of enamel. Recently, amelogenin has been detected in various epithelial and mesenchymal tissues, implicating that it might have distinct functions in various tissues. We have previously reported that leucine rich amelogenin peptide (LRAP), one of the alternate splice forms of amelogenin, regulates receptor activator of NF-kappa B ligand (RANKL) expression in cementoblast/periodontal ligament cells, suggesting that the amelogenins, especially LRAP, might function as a signaling molecule in bone metabolism. The objective of this study was to identify and define LRAP functions in bone turnover. We engineered transgenic (TgLRAP) mice using a murine 2.3kb α1(I)-collagen promoter to drive expression of a transgene consisting of LRAP, an internal ribosome entry site (IRES) and enhanced green fluorescent protein (EGFP) to study functions of LRAP in bone formation and resorption. Calvarial cell cultures from the TgLRAP mice showed increased alkaline phosphatase (ALP) activity and increased formation of mineralized nodules compared to the cells derived from wild-type (WT) mice. The TgLRAP calvarial cells also showed an inhibitory effect on osteoclastogenesis in vitro. Gene expression comparison by quantitative polymerase chain reaction (Q-PCR) in calvarial cells indicated that bone formation makers such as Runx2, Alp, and osteocalcin were increased in TgLRAP compared to the WT cells. Meanwhile, Rankl expression was decreased in the TgLRAP cells in vitro. The ovariectomized (OVX) TgLRAP mice resisted bone loss induced by ovariectomy resulting in higher bone mineral density in comparison to OVX WT mice. The quantitative analysis of calcein intakes indicated that the ovariectomy resulted in increased bone formation in both WT and TgLRAP mice; OVX TgLRAP appeared to show the most remarkably increased bone formation. The parameters for bone resorption in tissue sections showed increased number of osteoclasts in OVX WT, but not in OVX TgLRAP over that of sham operated WT or TgLRAP mice, supporting the observed bone phenotypes in OVX mice. This is the first report identifying that LRAP, one of the amelogenin splice variants, affects bone turnover in vivo.

Anti-Siglec-15 antibody suppresses bone resorption by inhibiting osteoclast multinucleation without attenuating bone formation

Anti-resorptive drugs are widely used for the treatment of osteoporosis, but excessive inhibition of osteoclastogenesis can suppress bone turnover and cause the deterioration of bone quality. Sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) is a transmembrane protein expressed on osteoclast precursor cells and mature osteoclasts. Siglec-15 regulates proteins containing immunoreceptor tyrosine-based activation motif (ITAM) domains, which then induce nuclear factor of activated T-cells 1 (NFATc1), a master transcription factor of osteoclast differentiation. Anti-Siglec-15 antibody modulates ITAM signaling in osteoclast precursors and inhibits the maturation of osteoclasts in vitro. However, in situ pharmacological effects, particularly during postmenopausal osteoporosis, remain unclear. Here, we demonstrated that anti-Siglec-15 antibody treatment protected against ovariectomy-induced bone loss by specifically inhibiting the generation of multinucleated osteoclasts in vivo. Moreover, treatment with anti-Siglec-15 antibody maintained bone formation to a greater extent than with risedronate, the first-line treatment for osteoporosis. Intravital imaging revealed that anti-Siglec-15 antibody treatment did not cause a reduction in osteoclast motility, whereas osteoclast motility declined following risedronate treatment. We evaluated osteoclast activity using a pH-sensing probe and found that the bone resorptive ability of osteoclasts was lower following anti-Siglec-15 antibody treatment compared to after risedronate treatment. Our findings suggest that anti-Siglec-15 treatment may have potential as an anti-resorptive therapy for osteoporosis, which substantially inhibits the activity of osteoclasts while maintaining physiological bone coupling.

Human Immunodeficiency Virus (HIV) and Menopause Are Independently Associated With Lower Bone Mineral Density: Results From the Women's Interagency HIV Study

BACKGROUND

We previously reported lower bone mineral density (BMD) among premenopausal women with HIV (WWH) compared to women without HIV (HIV-). Rate of bone loss may be even greater for WWH during the menopausal transition.

METHODS

Pre-, peri- and postmenopausal women in the Women\'s Interagency HIV Study (WIHS) underwent whole body DXA and central quantitative computed tomography to measure areal BMD (aBMD) and volumetric BMD (vBMD), respectively. Multivariable regression models with covariates associated with low aBMD (T score < -1.0) in univariate analyses (P≤.05) and known risk factors for low BMD assessed contributions of HIV and menopausal stage to the prediction of aBMD.

RESULTS

Compared to HIV- women, in unadjusted analyses, WWH had 5-9% lower aBMD at the lumbar spine (P=.001), femoral neck (P=.04), total hip (P=.003) and the ultradistal radius (P=.004), and higher osteoporosis prevalence (T score<-2.5) at the ultradistal radius only (13.5% vs 0%, P=.0003). WWH also had lower vBMD at the spine and hip. In fully adjusted models, HIV independently predicted reduced aBMD at the lumbar spine, total hip, femoral neck, and ultradistal radius; menopausal stage remained a significant predictor of lumbar spine and ultradistal radius aBMD.

CONCLUSIONS

HIV infection and menopausal stage were independent predictors of lower BMD, and had an additive effect on lumbar spine and total hip BMD. Additional research is needed to better understand underlying mechanisms by which HIV impacts BMD as women age and transition through menopause, and develop strategies to mitigate osteoporosis and fracture risk in this growing population.

Prednisolone suppresses collagen-encoding gene expression causing cartilage defects in zebrafish larvae

Glucocorticoid-induced osteoporosis (GIOP) is a clinically important disease. Despite many studies, the intrinsic pathogenesis of GIOP is still not fully understood. Cartilage is the target tissue of the glucocorticoid prednisolone (PN). To explore the intrinsic mechanism of PN-induced cartilage damage, we performed cartilage staining and cell transfection experiments in zebrafish larvae treated with PN. The results showed that PN caused cartilage damage in zebrafish at 25 μM. Moreover, after treatment with PN, it was found that collagen-encoding gene expression was significantly reduced. Further research revealed that the glucocorticoid receptor (GR) mediates the transcriptional inhibition of collagen genes by PN. These results indicate that glucocorticoids cause cartilage damage by inhibiting the expression of collagen genes through their receptors. Our study provides new insights into GIOP.

Sex Difference in the Socioeconomic Burden of Osteoporosis among South Koreans

Background: The prevalence of osteoporosis is increasing with the aging of the population and the socioeconomic burden. The purpose of this study was to determine the socioeconomic burden of osteoporosis in Korea. Methods: The prevalence of osteoporosis was analyzed using 2017 National Patients Sample and Korea National Health and Nutrition Examination Survey data. Direct costs were divided into healthcare and non-healthcare costs, and indirect costs were calculated by assessing the cost of loss of productivity for labor loss due to disease. Results: The prevalence of osteoporosis diagnosis was 1.91% in total, which was 13 times higher in women than in men (3.57% vs. 0.26%). The socioeconomic cost of osteoporosis was 299.1 million USD based on main diagnosis, and the cost was 13 times higher in women than in men (277.6 vs. 21.5 million USD). The total cost based on main and secondary diagnosis was 981.8 million USD. Similarly, the cost was seven times higher in women than in men (862.4 vs. 119.4 million USD). Conclusions: Osteoporosis increases the socioeconomic burden of disease, and it is significantly higher in women than in men. The policy support for the implementation of prevention and management programs would be necessary to reduce the burden of osteoporosis.

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.

Pharmacological properties of durva swaras (Cynodon dactylon L. Pers.) in an ovariectomised rat model mimicking chronic menopausal syndrome

Hormonal replacement therapy (HRT), as the first-line management of chronic menopausal syndrome (CMS) in women, has limited application due to adverse effects. We aimed to evaluate the therapeutic potential of a herbal alternative (HALT), durva swaras (DS) of Cynodon dactylon L. Pers., in a CMS rat model. Female Sprague-Dawley rats were subjected to Sham and ovariectomy (OVX) surgery. OVX rats received either 0.11 mg/kg oestrogen as a positive treatment control or 1 (DS1), 2 (DS2), and 4 (DS3) g/kg DS for 160 days. Vaginal smear tests indicated the menopausal status. Routine clinical examinations, weekly body weights (BW), serum calcium, proinflammatory cytokines, and reproductive hormones levels were monitored. Clinical chemistry, body composition, bone mineral density (BMD), uterotrophic response, bone morphometry, and histopathology of major organs were evaluated. BW of OVX rats increased by 18-25% compared to Sham. Total fat and fat percentage were significantly elevated in the oestrogen group compared to DS2, DS3, and OVX group. DS treatment groups showed the levels of TNF- α was slightly reduced, while IL-1β and IL-6 levels were significantly reduced (P < 0.05) compared to the oestrogen treated group. DS treatment restored serum calcium levels, while BMD, bone quality, osteoblast/osteoclast ratio, and collagen levels improved in both DS and oestrogen treatment groups. The uterotrophic assay demonstrated non-oestrogenic activity of DS. Endometrial hyperplastic change was observed in oestrogen-treated rats. The preclinical non-oestrogenic activity of DS has therapeutic potential in CMS through anti-inflammatory and osteo-protective effects. Further clinical research into DS, as a viable HALT to HRT, is required.

The predictive significance of bone mineral density on postoperative pain relief in knee osteoarthritis patients after total knee arthroplasty: A prediction model

BACKGROUND

Bone mineral density (BMD) may be an important factor affecting the clinical outcomes after total knee arthroplasty (TKA). However, further information regarding BMD in postoperative pain relief is not present yet. This study aims to gain further insight into the predictive significance of BMD in postoperative pain relief in knee osteoarthritis (KOA) patients after TKA.

METHODS

156 KOA patients treated by TKA were included in this study. Visual analogue scale (VAS) was used to measure the pain intensity in patients within one year after TKA. The patients were divided into good pain relief group (the improvement of VAS ≥ 3) and poor pain relief group (the improvement of VAS < 3). BMD and other clinical characteristics were also collected. Logistic regression analysis and receiver operating characteristic curve (ROC curve) were used to evaluate the predictive significance of BMD. Subgroup analysis was used to compare the difference of postoperative pain between High BMD group and Low BMD group extra.

RESULTS

34 (21.8%) patients had poor pain relief after TKA. Logistic regression analysis indicated that age, BMD, preoperative hospital for special surgery (HSS) scores, preoperative VAS score and postoperative posterior slope angles (PSA) were the risk factors of poor pain relief (P < 0.05). Using BMD as a predictor, the optimum cut-off value of poor pain relief was T-level = -3.0 SD in the ROC curve, where sensitivity and specificity were 73.5% and 83.7%, respectively. Based on this cut-off value, obvious pain relief was observed in the High BMD group compared with Low BMD group from the 6th month after TKA in the subgroup analysis (P < 0.05).

CONCLUSIONS

BMD is an effective predictor for postoperative pain relief in KOA patients after TKA, and the poor pain relief should be fully considered especially when BMD T-level ≤ -3.0 SD.