The role of lipid metabolism in osteoporosis: Clinical implication and cellular mechanism

The bone-vascular axis: the link between osteoporosis and vascular calcification

Osteoporosis and vascular calcification are chronic metabolic diseases threatening the health of aging people. The incidence of osteoporosis and vascular calcification increases year by year, and has drawn much attention from the scientific and clinical area. Many studies have found that osteoporosis and vascular calcification are not completely independent, but there are close correlations between them in the pathogenesis and underlying mechanisms. The underlying mechanisms of osteoporosis and vascular calcification include aging, oxidative stress, inflammatory response, lipid metabolism, calcium and phosphorus metabolism, vitamins, autophagy, and extracellular vesicles. This review updates the current understanding of the correlation and underlying mechanisms of osteoporosis and vascular calcification, and highlights the complexity of the bone-vascular axis, aiming to provide novel ideas for the prevention and treatment of osteoporosis and vascular calcification.

Role of denosumab in lipid metabolism disorders: clinical significance and potential mechanisms

PURPOSE

Lipid metabolism disorders, characterized by abnormal blood lipid levels, are central to the pathogenesis of obesity, nonalcoholic fatty liver disease (NAFLD), and atherosclerosis. These conditions increase the risk of type 2 diabetes, cardiovascular diseases (CVD), and stroke, highlighting the need for novel therapeutic approaches. Emerging evidence suggests a complex interplay between bone and lipid metabolism, with RANKL playing a key role. This review explores the potential of denosumab, a RANKL-targeting monoclonal antibody, in modulating lipid metabolism and its broader metabolic implications.

METHODS

We conducted a comprehensive literature review to analyze the molecular mechanisms by which denosumab influences lipid metabolism, with a focus on the OPG/RANKL/RANK signaling pathway. Additionally, we examined the roles of immune modulation, bone marrow adipose tissue, and gut microbiota in metabolic diseases.

RESULTS

Denosumab, primarily known for its anti-resorptive effects in osteoporosis, may also exert beneficial effects on lipid metabolism. Preclinical and clinical studies suggest its potential in ameliorating obesity, NAFLD, and atherosclerosis. The OPG/RANKL/RANK axis appears to mediate crosstalk between bone and metabolic pathways, while immune regulation and gut microbiota may further contribute to these effects.

CONCLUSION

Denosumab shows promise as a therapeutic agent for lipid metabolism disorders, though long-term metabolic effects remain unclear. Further research is needed to validate its efficacy and elucidate underlying mechanisms, which could pave the way for novel treatments targeting metabolic diseases.

Relationship between blood lipids and bone mineral density in healthy preschoolers: a 12-month cohort study

OBJECTIVES

A prospective study was conducted examining the association between blood lipid levels and bone mineral density in preschool-aged children.

METHODS

Healthy preschool-aged children (n=411) were included in this 12-month cohort study. The bone mineral density and bone mineral content of the non-dominant forearm and calcaneus were measured using dual-energy X-ray absorptiometry (DXA). Additionally, the children's fasting blood was drawn at baseline to measure blood lipids.

RESULTS

The sample comprised 411 healthy preschool-aged children, 208 girls and 203 boys, with a mean age of 4.80±0.70 years. After one year of observation, the bone mineral density of the non-dominant calcaneus in preschool children increased by 30.37 mg/cm2, bone mineral content increased by 29.85 mg, and triglyceride levels increased by 0.05 mmol/L. A significant inverse assocation was observed between serum triglyceride levels within the normal physiological range and the changes in bone mineral density (BMD) at the non-dominant calcaneus in preschool children, whereas no such association was detected with BMD changes in the non-dominant forearm. A 1 mmol/L increase in triglycerides within the physiological normal range was associated with a 6.73 mg/cm2 decrease in bone mineral density (95 % CI: -12.90, -0.56) and a 5.98 mg decrease in bone mineral content (95 % CI: -11.77, -0.19). There was no significant relationship between other lipids and bone mineral density.

CONCLUSIONS

Serum triglyceride concentrations within the physiological normal range showed a significant negative correlation with the 12-month increment of calcaneal bone mineral density in preschool children (p<0.05).

Immune Cells as Mediators of Lipidome Influence on Osteoporosis: Evidence from a Mediation Analysis

Background: Although clinical studies have indicated a possible association between dyslipidemia and osteoporosis, the underlying genetic basis and mechanistic pathways remain insufficiently defined. Most prior research has concentrated on conventional lipid markers, which are prone to confounding and limit causal inference. Exploring lipidomic profiles offers a more comprehensive view of lipid metabolism and may reveal novel genetic links beyond traditional lipid traits. Additionally, alterations in immune cell function, often triggered by metabolic disturbances, may contribute to osteoporosis development; however, the potential mediating role of immune cells in the lipid-bone axis has not been systematically investigated. Methods: A total of 179 lipid species across 13 lipid classes were analyzed in 7174 Finnish individuals from the GeneRISK cohort. Genome-Wide Association Study (GWAS) summary statistics for osteoporosis and 731 immune cell immunophenotypes were sourced from the GWAS Catalog. A two-step, two-sample Mendelian randomization analysis, using inverse variance weighting (IVW), was conducted to explore the potential causal effects of lipids on osteoporosis and the mediating role of immune cells in the relationship between lipids and osteoporosis. Results: Mendelian randomization analysis indicated that triacylglycerol levels of 48:0 were possibly associated with an increased risk of osteoporosis (IVW: odds ratio [OR] 1.1320, 95% CI 1.0401-1.2321; p = 0.004), while triacylglycerol levels of 48:3 appeared to be associated with a reduced risk of osteoporosis (IVW: OR 0.9053, 95% CI 0.8364-0.9800; p = 0.014). Two statistically significant mediating effects were identified: First, IgD- CD38dim %B cells appeared to partially negatively mediate the association between triacylglycerol levels of 48:3 and osteoporosis, with a negative mediating effect of -0.00669 (95% CI: -0.0214, 0.00805), which accounted for 6.73% of the total effect. That is, the protective effect of triacylglycerol levels of 48:3 against osteoporosis was attenuated by IgD- CD38dim %B cells. Second, HLA DR++ monocytes% leukocytes also partially negatively mediated this relationship, with a mediating effect of -0.023 (95% CI: -0.0434, -0.00266), accounting for 23.2% of the total effect. This indicates that other immune cells, HLA DR++ monocytes %leukocytes, resisted the protective effect of triacylglycerol levels of 48:3 against osteoporosis, with a weakening effect stronger than that of IgD- CD38dim %B cells. Conclusions: Our findings contribute to the growing understanding of the potential causal relationships and shared pathogenic mechanisms between dyslipidemia and osteoporosis. The results suggest that the potential genetic effects of plasma lipid metabolites on osteoporosis may be partially down-regulated by specific kinds of immune cells.

Diverse Bone Matrix and Mineral Alterations in Osteoporosis with Different Causes: A Solid-State NMR Study

Osteoporosis (OP), which is a common skeletal disease with different causes, is prevalent in the aging population. Postmenopause women generally suffer from OP with bone loss due to estrogen deficiency. Diabetes is also associated with OP by complex metabolic mechanisms. Bone qualities of OP caused by aging were compared with those of the ovariectomy (OVX) model and the Type 2 diabetic model using Sprague-Dawley (SD) rats in our study. Combining with micro-computed tomography (μ-CT) and solid-state NMR (SSNMR) methods, this research studied bone changes in SD rats from tissue level to the molecular level. The studies revealed bone loss was most significant for cancellous bones but not for cortical bones in OP rats. However, at the molecular level, the content of HAP in cortical bone increased with aging, contributing to the brittleness of the bone. Triglyceride, as a senescence maker of osteocyte in cortical bone, was also identified to be closely associated with OP in aging and OVX rats but not in diabetic rats. This research suggests that changes of bone quality at the molecular level more objectively reflect the bone tissue reconstruction of OP with various causes rather than mere bone loss revealed by μ-CT analysis.

Advances in omics technologies for traditional Chinese medicine in the prevention and treatment of metabolic bone diseases

Metabolic bone disease (MBD), as one of the most severe metabolic disorders, remains a focal point and challenge in medical research. Numerous studies have demonstrated the efficacy of Traditional Chinese Medicine (TCM) in preventing and treating MBD. However, the inherent complexity of TCM metabolites poses significant limitations in elucidating their mechanisms of action. The advancement of omics technologies, including metabolomics, proteomics, and transcriptomics, has greatly facilitated research on MBD. These approaches enable the identification of potential biomarkers and the exploration of metabolic pathways and mechanisms underlying TCM interventions for MBD. Evidence indicates that TCM monomers, single botanical drugs, and herbal formulations are effective, safe, and well-tolerated in MBD prevention and treatment. This review summarizes recent applications and key findings of transcriptomics, proteomics, and metabolomics in studying the mechanisms of TCM interventions for MBD. It highlights the role of omics technologies in uncovering relevant metabolites and pathways under TCM treatment, providing valuable insights and clinical references for TCM-based strategies in managing MBD.

A high-fructose diet leads to osteoporosis by suppressing the expression of Thrb and facilitating the accumulation of cholesterol

Osteoporosis is classified as a metabolic syndrome, and the consumption of fructose has been linked to various metabolic diseases. However, the specific effects and underlying mechanisms of fructose on bone health remain inadequately understood. In this study, we demonstrate that fructose intake can exacerbate bone loss in murine models by facilitating the accumulation of cholesterol within the bones. We identify Thyroid Hormone Receptor Beta (Thrb) and Protein Kinase C Zeta (Prkcz) as potential therapeutic targets for the treatment of osteoporosis. Mice subjected to a high-fructose diet exhibited a reduction in bone density and a decrease in the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) compared to those on a standard diet. Fructose treatment was found to decrease Thrb expression while increasing Prkcz expression, leading to cholesterol accumulation and hindering the osteogenic differentiation of BMSCs. Furthermore, our findings indicate that the activation of Thrb and the inhibition of Prkcz significantly ameliorate bone loss in mice. This study elucidates the molecular mechanisms by which fructose influences osteogenesis through the Thrb/Prkcz/cholesterol accumulation pathway in the context of osteoporosis, thereby highlighting the therapeutic potential of Thrb and Prkcz as targets for osteoporosis treatment.

Therapeutic potential of total flavonoids of Rhizoma Drynariae: inhibiting adipogenesis and promoting osteogenesis via MAPK/HIF-1α pathway in primary osteoporosis

AIM

This study seeks to confirm the therapeutic effectiveness of TRFD in inhibiting adipogenesis and promoting osteogenesis in primary osteoporosis through the MAPK/HIF-1α signaling pathway. C57BL/6J mice underwent ovariectomy (OVX) to induce osteoporosis. Mice were administered TRFD (Low and high doses)estradiol for a duration of 12 weeks. Bone microarchitecture evaluated using Micro-CT, while serum biomarkers and protein expressions were analyzed through enzyme-linked immunosorbent assay, Western blotting, and immunohistochemistry. Furthermore, BMSC were isolated to show differentiation, Osteogenic and adipogenic induction were performed, including ALP activity and Oil Red O staining. Bioinformatics analysis of RNA sequencing data was conducted to identify differentially expressed genes.

RESULTS

Total flavonoids of Rhizoma Drynariae treatment significantly improved bone microarchitecture and reversed histopathological damage in OVX mice. It increased serum levels of osteogenesis markers (RUNX2, BMP-2) and enhanced MAPK and HIF-1α signaling pathways, The results also showed a significant dose, TFDR enhanced the osteogenic differentiation of BMSCs while suppressing adipogenic differentiation, as demonstrated by increased ALP activity and mineralization, alongside, the expression of lipid markers (PPAR-γ, C/EBPα) was inhibited. Furthermore, MAPK/HIF-1α pathway was confirmed be crucial in mediating these effects.

CONCLUSION

TRFD exhibits significant therapeutic potential in treating primary osteoporosis by promoting osteogenesis and inhibiting adipogenesis through the MAPK/HIF-1α pathway. These establish an investigation of TRFD as a natural treatment option for managing osteoporosis.

CLINICAL TRIAL NUMBER

Not applicable.

Impact of Advanced Platelet-Rich Fibrin on Early Bone Healing After Endodontic Microsurgery: A Randomized Controlled Trial

Background: Apical surgery can address periapical pathologies when conventional endodontic treatments fail. Advanced platelet-rich fibrin (A-PRF) has emerged as a regenerative material with the potential to enhance healing in periapical surgery. In this study, we evaluated the effect of A-PRF on periapical lesion healing using cone beam computed tomography (CBCT). Methods: A randomized controlled trial at Rīga Stradiņš University Institute of Stomatology included 43 participants (15 males, 28 females; mean age: 44 years) with periradicular lesions. Participants were divided into experimental and control groups. Baseline and follow-up CBCT imaging assessed lesion volumes at 6 and 12 months post-surgery. Results: Mean lesion volumes significantly decreased from 431.4 mm3 at baseline to 102.8 mm3 at 6 months and 49.2 mm3 at 12 months (p < 0.001). A-PRF did not significantly reduce the lesion sizes compared to the controls (p = 0.043), but was associated with reduced inflammation and enhanced soft tissue healing. Key confounders included gender and baseline lesion volume, with males exhibiting smaller lesion sizes postoperatively. Conclusions: The results suggest that A-PRF may not offer a significant advantage in terms of reducing defect size or improving radiographic resolution.

[Knockdown of NPTX1 promotes osteogenic differentiation of human bone marrow mesenchymal stem cells]

OBJECTIVE

To initially investigate the function of neuronal pentraxin 1 (NPTX1) gene on osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs).

METHODS

hBMSCs were induced to undergo osteogenic differentiation, and then RNA was collected at different time points, namely 0, 3, 7, 10 and 14 d. The mRNA expression levels of key genes related with osteogenic differentiation, including runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), osteocalcin (OCN), and NPTX1, were detected on the basis of quantitative real-time polymerase chain reaction (qPCR) technology. In order to establish a stable NPTX1-knockdown hBMSCs cell line, NPTX1 shRNA lentivirus was constructed and used to infect hBMSCs. ALP staining, alizarin red (AR) staining, and qPCR were employed to assess the impact of NPTX1-knockdown on the osteogenic differentiation ability of hBMSCs.

RESULTS

The results showed that during the osteogenic differentiation of hBMSCs in vitro, the mRNA expression levels of osteogenic genes RUNX2, ALP and OCN significantly increased compared with 0 d, while NPTX1 expression decreased markedly (P < 0.01) as the osteogenic induction period exten-ded. At 72 h post-infection with lentivirus, the result of qPCR indicated that the knockdown efficiency of NPTX1 was over 60%. After knocking down NPTX1 in hBMSCs, RNA was extracted from both the NPTX1-knockdown group (sh NPTX1 group) and the control group (shNC group) cultured in regular proliferation medium. The results of qPCR showed that the expression levels of osteogenic-related genes RUNX2 and osterix (OSX) were significantly higher in the sh NPTX1 group compared with the shNC group (P < 0.01). ALP staining revealed a significantly deeper coloration in the sh NPTX1 group than in the shNC group at the end of 7 d of osteogenic induction. AR staining demonstrated a marked increase in mineralized nodules in the sh NPTX1 group compared with the shNC group at the end of 14 d of osteogenic induction.

CONCLUSION

NPTX1 exerts a modulatory role in the osteogenic differentiation of hBMSCs, and its knockdown has been found to enhance the osteogenic differentiation of hBMSCs. This finding implies that NPTX1 could potentially serve as a therapeutic target for the treatment of osteogenic abnormalities, including osteoporosis.

Identification of endoplasmic reticulum stress and mitochondrial dysfunction related biomarkers in osteoporosis

BACKGROUND

Endoplasmic reticulum stress (ERS) and mitochondrial dysfunction (MD) involved in bone metabolism disorders. However, the particular mechanisms of ERS and MD related genes (ERS&MDRGs) in osteoporosis (OP) have not been elucidated. In present study, biomarkers related to ERS and MD in OP were identified.

METHODS

Differentially expressed genes (DEGs) were obtained based on GEO dataset. ERS&MDRGs were derived from Genecard database. Initially, ERS&MD related DEGs (ERS&MDRDEGs) were obtained by overlapping DEGs and ERS&MDRGs. The key module was screened by WGCNA. The intersection of ERS&MDRDEGs and key module was screened by machine learning to obtain key genes. Then, receiver operating characteristic curve (ROC) was drawn to calculated diagnostic accuracy of key genes. The ssGSEA and Cibersort algorithms were performed to analyze immune cell infiltration. The miRNA-mRNA-TF network were draw by cytoscape software. Moleculaer docking and DGIdb database were employed for screening potential drugs. Finally, the expression of key genes was verified by qRT-PCR.

RESULTS

The 122 ERS&MDRDEGs were obtained by preliminary screening. ERS&MDRDEGs were mainly enriched in lipid metabolism, calcium ion transport, and ossification. The 5 key genes were identified, including AAAS, ESR1, SLC12A2, TAF15, and VAMP2. Immune infiltration analysis showed monocyte and macrophage were different between OP and control groups. The miRNA-mRNA-TF regulatory network indicated has-miR-625-5p, has-miR-296-3p, CTCT and EP300 as potential regulatory targets. The 2 potential small molecule drugs, namely bumetanide and elacestrant were screened. The expression of AAAS, ESR1, VAMP2 were higher, and SLC12A2 and TAF15 were lower in OP than control group.

CONCLUSION

This research identified 5 key genes AAAS, ESR1, SLC12A2, TAF15 and VAMP2. Bumetanide and elacestrant were potential drugs. These findings provided valuable insights into the pathophysiology of OP and the development of new therapeutic strategies.

The association of lipids and novel non-statin lipid-lowering drug target with osteoporosis: evidence from genetic correlations and Mendelian randomization

BACKGROUND

It remains controversial whether lipids affect osteoporosis (OP) or bone mineral density (BMD), and causality has not been established. This study aimed to investigate the genetic associations between lipids, novel non-statin lipid-lowering drug target genes, and OP and BMD.

METHODS

Mendelian randomization (MR) method was used to explore the genetic associations between 179 lipid species and OP, BMD. Drug-target MR analysis was used to explore the causal associations between angiopoietin-like protein 3 (ANGPTL3) and apolipoprotein C3 (APOC3) inhibitors on BMD.

RESULTS

The IVW results with Bonferroni correction indicated that triglyceride (TG) (51:3) (OR = 1.0029; 95% CI: 1.0014-1.0045; P = 0.0002) and TG (56:6) (OR = 1.0021; 95% CI: 1.0008-1.0033; P = 0.0011) were associated with an increased risk of OP; TG (51:2) (OR = 0.9543; 95% CI: 0.9148-0.9954; P = 0.0298) was associated with decreased BMD; and ANGPTL3 inhibitor (OR = 1.1342; 95% CI: 1.0393-1.2290; P = 0.0093) and APOC3 inhibitor (OR = 1.0506; 95% CI: 1.0155-1.0857; P = 0.0058) was associated with increased BMD.

CONCLUSIONS

MR analysis indicated causal associations between genetically predicted TGs and OP and BMD. Drug-target MR analysis showed that ANGPTL3 and APOC3 have the potential to serve as novel non-statin lipid-lowering drug targets to treat or prevent OP.

Ferrostatin-1 inhibits osteoclast differentiation and prevents osteoporosis by suppressing lipid peroxidation

BACKGROUND

Osteoporosis (OP) is a systemic disease characterized by low bone mass. New progress has been made in the study of OP, such as lipid peroxidation. However, the role of lipid peroxides in osteoclast differentiation is still unclear.

METHODS

Bone marrow macrophages (BMMs) were extracted from C57BL/6J mice and induced to differentiate into osteoclasts, which were observed via TRAP staining, Phalloidin staining and bone pit assays. Related substances of lipid peroxidation were detected during osteoclastogenesis. The levels of osteoclastogenesis and lipid peroxides were measured by qRT-PCR, Western Blot and immunofluorescence. Activation of the p38/JNK/MAPK pathway was detected by Western Blot. The capacity for osteogenesis and angiogenesis of cells after treatment with supernatant of BMMs was evaluated. Furthermore, Ferrostatin-1 (Fer-1), from which femur and serum samples were comprehensively evaluated, was used in OVX mice.

RESULTS

During osteoclastogenesis, the levels of ROS, MDA, ACSL4 and LPCAT3 increased with increasing duration of RANKL stimulation, while there were no significant changes in the levels of GSH or GPX4. Fer-1 inhibited osteoclast differentiation and decreased the level of lipid peroxides. In addition, Fer-1 inhibited osteoclast-related markers by inhibiting the p38/JNK/MAPK pathway. Furthermore, the supernatant of BMMs after Fer-1 treatment promoted osteogenesis and angiogenesis. Finally, Fer-1 successfully alleviated OP in OVX mice by reducing the level of lipid peroxidation in vivo.

CONCLUSION

Fer-1 suppresses osteoclast differentiation by reducing lipid peroxidation levels regulated by ACSL4, which is mediated through the p38/JNK/MAPK signaling pathway. Additionally, Fer-1 enhances the coupling between osteogenesis and angiogenesis and has an anti-OP effect in vivo.

Ethnobotanical usages, phytochemistry, pharmacology, and quality control of chuanxiong rhizoma: A review

ETHNOPHARMACOLOGIC RELEVANCE

Chuanxiong Rhizoma (CX) is the dried root rhizomes of the plant Ligusticum chuanxiong Hort. of the family Umbelliferae. CX is listed as a superior herb in the book "Shennong Bencao Jing". It has a pungent and warm nature and belongs to the liver, gallbladder, and pericardium meridians. CX is documented in the Chinese Pharmacopoeia from 1963 to 2020 editions. CX as a well-known traditional Chinese medicine for promoting blood circulation, regulating qi, dispelling wind, and relieving pain, has been proven to contain a variety of bioactive compounds with diverse pharmacological activities and medicinal value.

AIM OF THE STUDY

The current review aims to provide a comprehensive analysis of the botany, traditional uses, phytochemistry, pharmacology, toxicity, quality control and pharmacokinetics of CX.

MATERIALS AND METHODS

The relevant information of CX was obtained from several databases including Web of Science, PubMed, ACS Publications, Google Scholar, Baidu Scholar, CNKI, Ph.D, MSc dissertations, as well as The Catalogue of Life, Flora of China database, and The Global Biodiversity Information Facility.

RESULTS

CX is widely used in traditional medicine for treating various diseases related to the cardiovascular system, liver and kidney system, nervous system, respiratory system, and more. Over 400 compounds have been identified in CX, including phthalides, alkaloids, organic acids and its esters, polyphenols, terpenes and their derivatives, polysaccharides, hydrocarbons and their derivatives, coumarins, lignans and others. The plant extracts, compounds and Chinese patent medicines possess various pharmacological activities, including cardiovascular system protection, nervous system protection, cerebrovascular system protection, anti-inflammatory, liver and lung protection, anti-diabetes, anti-osteoporosis, anti-bacterial, anti-aging, anti-oxidant, immune regulation, prevention of DNA damage, prevention of postoperative peritoneal adhesion.

CONCLUSION

Considering its traditional and modern applications, phytochemical composition, and pharmacological properties, CX can be regarded as a traditional Chinese medicine resource for treating various diseases related to the cardiovascular, hepatorenal, nervous, and respiratory systems. Current research mainly focuses on cell and animal experiments, where some active ingredients exhibit diverse pharmacological activities. However, further studies are needed to fully understand its specific mechanisms of action. In addition, there are multiple active ingredients in CX, but current research mainly focuses on the pharmacological effects of individual components, with little research on the interactions and synergistic effects between different components. It is recommended to strengthen the research on the interactions of CX compounds and their components to reveal the overall pharmacological mechanisms. This will contribute to quality control, new drug development, commercialization, and promote its continuous development in the field of medicine.

The relationship between non-HDL-C/HDL-C ratio and bone mineral density: an NHANES study

Background

The non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) is a newly developed lipid parameter. However, the current research has only explored the relationship with lumbar spine bone mineral density, lacking studies on bone mineral density at other sites, total body bone mineral density, and an analysis of risk factors. This study aims to determine the potential association between NHHR and lumbar BMD, increase awareness of the impact of lipid levels on bone health.

Methods

By utilizing data from the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2018, we conducted univariate and generalized linear models (GLMs) analysis, stratified analysis, threshold effect analysis, smooth curve fitting and stratified analysis to investigate the association between NHHR and BMD. NHHR levels were categorized into tertiles (low, medium, and high) based on their distribution among the study population.

Results

The study included 8,671participants, studies have shown, the ratio of non-high-density lipoprotein to high-density lipoprotein (NHHR) exhibits a stratified correlation with bone mineral density (BMD). In the BMI subgroup, NHHR is significantly negatively correlated with BMD at multiple sites in the low-to-middle BMI group (BMI <25 kg/m2), while no significant correlation is found in the high BMI group (BMI ≥30 kg/m2). In the gender subgroup, NHHR has a more pronounced effect on male BMD, mainly reflected in the reduction of lumbar spine and total body BMD. In the age subgroup, the negative correlation between NHHR and BMD is strongest in the younger group (18-30 years), gradually weakening in the middle-aged (31-44 years) and older groups (45-59 years). Further analysis suggests that dyslipidemia may influence bone metabolism through pathways such as inflammation and oxidative stress.

Conclusion

The effect of NHHR on bone mineral density (BMD) varies by BMI, gender, and age. This study suggests that controlling NHHR levels may be a potential intervention target for bone health management, particularly for individuals with low-to-middle BMI, males, and younger populations. These findings offer a new perspective on the relationship between lipid metabolism and bone metabolism and provide scientific evidence for the development of personalized osteoporosis prevention and treatment strategies.

Insights into Medication-Induced Osteonecrosis of the Jaw Through the Application of Salivary Proteomics and Bioinformatics

Long-term treatment with bisphosphonates is accompanied by an increased risk of medication-related osteonecrosis of the jaw (MRONJ). Currently, no clinically useful biomarkers for the predictive diagnosis of MRONJ are available. To investigate the potential key proteins involved in the pathogenesis of MRONJ, a proteomic LC-MS/MS analysis of saliva was performed. Differentially expressed proteins (DEPs) were analyzed using BiNGO, ClueGO, cytoHubba, MCODE, KEGG, and ReactomeFI software packages using Cytoscape platforms. In total, 1545 DEPs were identified, including 43 up- and 11 down-regulated with a 1.5-fold cut-off value and adj. p-value < 0.05. The analysis provided a panel of hub genes, including APOA2, APOB, APOC2, APOC3, APOE, APOM, C4B, C4BPA, C9, FGG, GC, HP, HRG, LPA, SAA2-SAA4, and SERPIND1. The most prevalent terms in GO of the biological process were macromolecular complex remodeling, protein-lipid complex remodeling, and plasma lipoprotein particle remodeling. DEPs were mainly involved in signaling pathways associated with lipoproteins, the innate immune system, complement, and coagulation cascades. The current investigation advanced our knowledge of the molecular mechanisms underlying MRONJ. In particular, the research identified the principal salivary proteins that are implicated in the onset and progression of this condition.

Systemic Lipid Metabolism Dysregulation as a Possible Driving Force of Fracture Non-Unions?

INTRODUCTION

Non-unions are fractures that do not heal properly, resulting in a false joint formation at the fracture site. This condition leads to major health issues and imposes a burden on national healthcare systems. The etiology of non-unions is still not fully understood; therefore, we aimed to identify potential systemic factors that may contribute to their formation.

MATERIALS AND METHODS

We conducted a cross-sectional concomitant proteomic and metabolomic pilot study of blood plasma in patients with non-unions (N = 11) and compared them with patients with bone fracture in the normal active healing phase (N = 12).

RESULTS

We found five significantly upregulated proteins in the non-union group: immunoglobulin heavy variable 3-74, immunoglobulin lambda variable 2-18, low-density lipoprotein receptor-related protein 4, zinc-alpha-2-glycoprotein, and serum amyloid A-1 protein; and we found one downregulated protein: cystatin-C. The metabolomic study found differences in alanine, aspartate and glutamate metabolism pathways between two groups.

CONCLUSIONS

The combined results of proteomic and metabolomic analyses suggest that the dysregulation of lipid metabolism may contribute to non-union formation.

Potential molecular targets for the pharmacologic management of non-traumatic osteonecrosis

INTRODUCTION

Non-traumatic osteonecrosis is a debilitating condition marked by bone death, primarily due to reduced blood supply. Currently, no effective pharmacologic intervention is available to manage this condition effectively.

AREAS COVERED

Lipid metabolic disorders, chronic inflammation, vascular dysfunction, coagulopathy, and impaired bone homeostasis are suggested as the key pathogenic mechanisms involved in the development of non-traumatic osteonecrosis. Targeting any of these dysfunctions offers a potential avenue for pharmacologic intervention. However, the potential molecular targets for pharmacologic treatment of non-traumatic osteonecrosis remain underexplored. In this study, we reviewed available databases to compile a comprehensive set of pathogenic mechanisms and corresponding therapeutic targets for non-traumatic osteonecrosis.

EXPERT OPINION

Evidence suggests that a single pathogenic mechanism cannot fully explain the development of osteonecrosis, supporting the adoption of a multi-pathogenic theory. This theory implies that effective management of non-traumatic osteonecrosis requires targeting multiple pathogenic mechanisms simultaneously. Moreover, the same pathogenic mechanisms are unlikely to explain osteonecrosis development in patients with different etiologies. Consequently, a one-size-fits-all approach to medication is unlikely to be effective across all types of non-traumatic osteonecrosis. Future research should, therefore, focus on developing multi-target pharmacologic treatments tailored to the specific etiology of non-traumatic osteonecrosis.

Saturation Effect of Lipid Accumulation Product (LAP) Index on Spinal Bone Mineral Density: A Population-Based Study

Lipid accumulation product (LAP) has a positive effect on spinal bone mineral density (BMD). However, once LAP levels exceed 27.26, the rate of spinal BMD increase slow down or even decline. This indicates a biphasic relationship between lipid metabolism and BMD, suggesting potential benefits within a certain range and possible adverse effects beyond that range. This study aimed to investigate the potential association between LAP index and BMD in US adults, as well as to explore the presence of a potential saturation effect in this relationship. This study analyzed data from the National Health and Nutrition Examination Survey (NHANES) spanning from 2007 to 2018. A multiple stepwise regression model was employed to examine the association between LAP index and total spinal BMD. Additionally, a generalized additive model and a smooth curve fitting algorithm were utilized to examine the relationship, and saturation effect study was conducted to determine the saturation level. The calculation formula of LAP used in the study was: (LAP = (waist circumstances (WC) (cm) - 58) × triglyceride (TG) (mmol/L)) for women, and (LAP = (WC (cm) - 65) × TG (mmol/L)) for men. The study involved a total of 7913 participants aged 20 years or older. Through multiple stepwise regression analysis, it was found that individuals with higher LAP scores exhibited higher total spinal BMD. In both the crude and partially adjusted models, total spinal BMD was significantly higher in the highest LAP quartile (Q4) compared to the lowest LAP quartile (Q1) (P < 0.05). Utilizing a generalized additive model and smooth curve, a nonlinear relationship between LAP and total spinal BMD was observed. Furthermore, the study identified the saturation value of LAP to be 27.26, indicating a saturation effect. This research highlights a nonlinear relationship between LAP and total spinal BMD, along with the presence of a saturation effect.

From Genomics to Metabolomics: Molecular Insights into Osteoporosis for Enhanced Diagnostic and Therapeutic Approaches

Osteoporosis (OP) is a prevalent skeletal disorder characterized by decreased bone mineral density (BMD) and increased fracture risk. The advancements in omics technologies-genomics, transcriptomics, proteomics, and metabolomics-have provided significant insights into the molecular mechanisms driving OP. These technologies offer critical perspectives on genetic predispositions, gene expression regulation, protein signatures, and metabolic alterations, enabling the identification of novel biomarkers for diagnosis and therapeutic targets. This review underscores the potential of these multi-omics approaches to bridge the gap between basic research and clinical applications, paving the way for precision medicine in OP management. By integrating these technologies, researchers can contribute to improved diagnostics, preventative strategies, and treatments for patients suffering from OP and related conditions.

Non-linear association of the platelet/high-density lipoprotein cholesterol ratio with bone mineral density a cross-sectional study

BACKGROUND

Numerous studies have demonstrated shared risk factors and pathophysiologic mechanisms between osteoporosis and cardiovascular disease. High-density lipoprotein cholesterol (HDL-C) and platelets have long been recognized as crucial factors for cardiovascular health. The platelet to HDL-C ratio (PHR) combines platelet count and high-density lipoprotein cholesterol (HDL-C) level, It is a novel biomarker for metabolic syndrome and cardiovascular disease. The platelet to HDL-C ratio (PHR) possibly reflects the balance between proinflammatory and anti-inflammatory states in the body. Therefore, we hypothesized that changes in PHR ratios may predict a predisposition to pro-inflammatory and increased bone resorption. However, the relationship between the platelet to HDL-C ratio (PHR) and bone mineral density (BMD) remains insufficiently understood. This study aimed to elucidate the relationship between the platelet to HDL-C ratio (PHR) index and bone mineral density (BMD).

METHODS

Data from the NHANES 2005-2018 were analyzed, excluding adults with missing key variables and specific conditions. Nonlinear relationships were explored by fitting smoothed curves and generalized additive models, with threshold effects employed to calculate inflection points. Additionally, subgroup analyses and interaction tests were conducted.

RESULTS

The study included 13,936 individuals with a mean age of 51.19 ± 16.65 years. Fitted smoothed curves and generalized additive models revealed a nonlinear, inverted U-shaped relationship between the two variables. Threshold effect analysis showed a significant negative association between PHR and total femur bone mineral density (BMD) beyond the inflection point of platelet to HDL-C ratio (PHR) 33.301. Subgroup analyses showed that a significant interaction between these two variables was observed only in the age and sex subgroups (P-interaction < 0.05).

CONCLUSIONS

Our study identified a complex, nonlinear, inverted U-shaped relationship between platelet to HDL-C ratio (PHR) and total femur bone mineral density (BMD). These findings underscore the importance of maintaining optimal PHR levels to support bone health, especially in high-risk populations.