Metabolomics profiling reveals Echinops latifolius Tausch improves the trabecular micro-architecture of ovariectomized rats mainly via intervening amino acids and glycerophospholipids metabolism

Metabolic factors are not the direct mediators of the association between type 2 diabetes and osteoporosis

Objective

The causal relationship between type 2 diabetes mellitus (T2DM) and osteoporosis (OS) remains unclear. This study aims to investigate the causal relationship and explore the potential metabolic mechanism and its mediating role.

Methods

We conducted a comprehensive study, gathering data on 490,089 T2DM patients from the genome-wide association study (GWAS) database and selecting OS data from FinnGen and MRC-IEU sources, including 212,778 and 463,010 patients, respectively, for causal analysis. Simultaneously, we explored the potential roles of three obesity traits and 30 metabolic and inflammation-related mediating variables in the causal relationship.

Results

There is a strong causal relationship between T2DM and OS. The data from our two different database sources appeared in the same direction, but after correcting for body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR), the direction became the same. T2DM may increase the risk of OS [odds ratio (OR) > 1.5, p < 0.001]. Steiger's test results show that there is no reverse causality. No risk factors related to glycolipid metabolism, amino acid metabolism, and inflammation were found to mediate the causal relationship.

Conclusion

This study's findings indicate a robust causal relationship between T2DM and OS, influenced by relevant factors such as BMI. Our results shed light on the pathogenesis of OS and underscore the importance for clinicians to treat metabolic disorders to prevent osteoporosis.

Integrated proteomics and metabolomics analysis of sclerosis-related proteins and femoral head necrosis following internal fixation of femoral neck fractures

Femoral head necrosis (FHN) is a serious complication after femoral neck fractures (FNF), often linked to sclerosis around screw paths. Our study aimed to uncover the proteomic and metabolomic underpinnings of FHN and sclerosis using integrated proteomics and metabolomics analyses. We identified differentially expressed proteins (DEPs) and metabolites (DEMs) among three groups: patients with FNF (Group A), sclerosis (Group B), and FHN (Group C). Using the Kyoto Encyclopedia of Genes and Genomes and Gene Ontology enrichment analyses, we examined the roles of these proteins and metabolites. Our findings highlight the significant differences across the groups, with 218 DEPs and 44 DEMs identified between the sclerosis and FNF groups, 247 DEPs and 31 DEMs between the FHN and sclerosis groups, and a stark 682 DEPs and 94 DEMs between the FHN and FNF groups. Activities related to carbonate dehydratase and hydrolase were similar in the FHN and sclerosis groups, whereas extracellular region and lysosome were prevalent in the FHN and FNF groups. Our study also emphasized the involvement of the PI3K-Akt pathway in sclerosis and FHN. Moreover, the key metabolic pathways were implicated in glycerophospholipid metabolism and retrograde endocannabinoid signaling. Using western blotting, we confirmed the pivotal role of specific genes/proteins such as ITGB5, TNXB, CA II, and CA III in sclerosis and acid phosphatase 5 and cathepsin K in FHN. This comprehensive analyses elucidates the molecular mechanisms behind sclerosis and FHN and suggests potential biomarkers and therapeutic targets, paving the way for improved treatment strategies. Further validation of the findings is necessary to strengthen the robustness and reliability of the results.

Early changes of bone metabolites and lymphocyte subsets may participate in osteoporosis onset: a preliminary study of a postmenopausal osteoporosis mouse model

Purpose

Metabolic and immune changes in the early stages of osteoporosis are not well understood. This study aimed to explore the changes in bone metabolites and bone marrow lymphocyte subsets and their relationship during the osteoporosis onset.

Methods

We established OVX and Sham mouse models. After 5, 15, and 40 days, five mice in each group were sacrificed. Humeri were analyzed by microCT. The bone marrow cells of the left femur and tibia were collected for flow cytometry analysis. The right femur and tibia were analyzed by LC-MS/MS for metabolomics analysis.

Results

Bone microarchitecture was significantly deteriorated 15 days after OVX surgery. Analysis of bone metabolomics showed that obvious metabolite changes had happened since 5 days after surgery. Lipid metabolism was significant at the early stage of the osteoporosis. The proportion of immature B cells was increased, whereas the proportion of mature B cells was decreased in the OVX group. Metabolites were significantly correlated with the proportion of lymphocyte subsets at the early stage of the osteoporosis.

Conclusion

Lipid metabolism was significant at the early stage of the osteoporosis. Bone metabolites may influence bone formation by interfering with bone marrow lymphocyte subsets.

UPLC/Q-TOF-MS-based Metabolomics Study of the Antiosteoporosis Effects of Vaccarin in Ovariectomized Mice

Osteoporosis is a systemic and metabolic bone disease that usually occurs in postmenopausal women, which mainly manifests as bone loss and increased bone fragility that both facilitate fracture. However, few drugs for osteoporosis have shown good efficacy and limited side effects. Vaccarin has demonstrated its antiosteoporosis effects by inhibiting the formation and osteolytic activities of osteoclasts in our previous investigation. In this study, multivariate statistical analysis and ultrahigh-performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry were used to analyze the serum metabolites of ovariectomized mice treated with or without vaccarin. As a result, 9 serum metabolites were identified as biomarkers. The metabolic levels of 3 crucial biomarkers, namely, lysophosphatidylcholine [22 : 6, (4Z, 7Z, 10Z, 13Z, 16Z, 19Z)], 1-linoleoylglycerophosphocholine and 1-palmitoyl-Sn-glycero-3-phosphocholine, that were correlated with glycerophospholipid metabolism increased and then decreased significantly after vaccarin treatment. Molecular docking analysis and osteoclasts differentiation experiment further revealed that vaccarin may bind with phospholipase A2 and downregulated its activity to reduce the osteoclastogenesis. Therefore, the occurrence of osteoporosis is closely related with glycerophospholipid metabolism disorders, and vaccarin exerts antiosteoporosis effects by reducing the levels of glycerophospholipid metabolites.

Applying Four-Step Characteristic Ion Filtering with HPLC-Q-Exactive MS/MS Spectrometer Approach for Rapid Compound Structures Characterization and Major Representative Components Quantification in Modified Tabusen-2 Decoction

Modified Tabusen-2 decoction (MTBD) is traditional Chinese Mongolia medicine, mainly used to treat osteoporosis. However, the precise material basis of this prescription is not yet fully elucidated. Herein, we establish an HPLC-Q-Exactive MS/MS spectrometer method with four-step characteristic ion filtering (FSCIF) strategy to quickly and effectively identify the structural features of MTBD and determine the representative compounds content. The FSCIF strategy included database establishment, characteristic ions summarization, neutral loss fragments screening, and secondary mass spectrum fragment matching four steps. By using this strategy, a total of 143 compounds were unambiguously or tentatively annotated, including 5 compounds which were first reported in MTBD. Nineteen representative components were simultaneously quantified with the HPLC-Q-Exactive MS/MS spectrometer, and it is suitable for eight batches of MTBD. Methodology analysis showed that the assay method had good repeatability, accuracy, and stability. The method established above was successfully applied to assess the quality of MTBD extracts. Collectively, our findings enhance our molecular understanding of the MTBD formulation and will allow us to control its quality in a better way. At the same time, this study can promote the development and utilization of ethnic medicine.

Application of metabolomics in osteoporosis research

Osteoporosis (OP) is a systemic disease characterized by bone metabolism imbalance and bone microstructure destruction, which causes serious social and economic burden. At present, the diagnosis and treatment of OP mainly rely on imaging combined with drugs. However, the existing pathogenic mechanisms, diagnosis and treatment strategies for OP are not clear and effective enough, and the disease progression that cannot reflect OP further restricts its effective treatment. The application of metabolomics has facilitated the study of OP, further exploring the mechanism and behavior of bone cells, prevention, and treatment of the disease from various metabolic perspectives, finally realizing the possibility of a holistic approach. In this review, we focus on the application of metabolomics in OP research, especially the newer systematic application of metabolomics and treatment with herbal medicine and their extracts. In addition, the prospects of clinical transformation in related fields are also discussed. The aim of this study is to highlight the use of metabolomics in OP research, especially in exploring the pathogenesis of OP and the therapeutic mechanisms of natural herbal medicine, for the benefit of interdisciplinary researchers including clinicians, biologists, and materials engineers.

Transcriptome analysis to reveal the mechanism of the effect of Echinops latifolius polysaccharide B on palmitate-induced insulin-resistant

Hepatic insulin resistance is a crucial pathological process in type 2 diabetes mellitus (T2DM) associated with visceral adiposity and metabolic disorders. Echinops latifolius polysaccharide B (ETPB), a polysaccharide extracted from Echinops latifolius Tausch, increases insulin sensitivity in the high-fat diet-fed and STZ induced SD rat model and even prevented hepatic metabolic disorders. However, the mechanism by which ETPB improves carbohydrate and lipid metabolisms in the liver with insulin resistance remains largely unknown. In the present work, an lnsulin resistance cell model (IR-HepG2) was established. Glucose consumption, glycogen content, triglycerides (TG), and free fatty acids (FFAs) levels were detected. The result revealed that the intervention of ETPB significantly increased glucose consumption and glycogen synthesis and reduced FFAs and TG production in IR-HepG2 cells. Further, we also employed RNA-seq to identify differentially expressed miRNAs (DEMs) and mRNAs (DEGs) with a fold change of ≥ 1.5 and p-value of <0.05. Finally, we identified 1028, 682, 382, 1614, 519 and 825 DEGs, and 71, 113, 94, 68, 52 and 38 DEMs in different comparisons, respectively. Based on a short time-series expression miner (STEM) analysis, six profiles were chosen for further analysis. Seventeen insulin resistance-associated dynamic DEGs were identified during ETPB stimulation. Based on these dynamic DEGs, the related miRNAs were acquired from DEMs, and an integrated miRNA-mRNA regulatory network was subsequently constructed. Besides, some DEGs and DEMs were validated using qPCR. This study provides transcriptomic evidence of the molecular mechanism involved in HepG2 insulin resistance, leading to the discovery of miRNA-based target therapies for ETPB.

The Interventional Effects of Tubson-2 Decoction on Ovariectomized Rats as Determined by a Combination of Network Pharmacology and Metabolomics

Post-menopausal osteoporosis (PMOP) is associated with estrogen deficiency and worldwide, is becoming increasingly more prevalent in aging women. Various anti-PMOP drugs have been developed to reduce the burden of PMOP; generally, these drugs are efficacious, but with some adverse side effects. Tubson-2 decoction (TBD), a popular traditional Mongolian medicine, has been used to treat PMOP for centuries. However, the precise mechanisms underlying the action of TBD on PMOP have yet to be fully elucidated. Herein, we combined network pharmacology with untargeted metabolomics to identify the key targets and metabolic pathways associated with the interventional effects of TBD on ovariectomized (OVX) rats. Furthermore, we investigated the bone histomorphometry of eight different groups of rats to evaluate the therapeutic effect of TBD. First, we established a TBD-target/PMOP network via network pharmacology; this network identified three key protein targets-vitamin D receptor (VDR), cytochrome P450 19A1 (CYP19A1), and 11β-hydroxysteroid dehydrogenase type 1 (HSD11B1). Morphological analysis showed that severe impairment of the bone micro-architecture in OVX rats could be improved by TBD administration. The TBD-treated rats had a significantly lower bone surface-to-tissue volume (BS/TV) and a significantly smaller trabecular separation (Tb·Sp.) (P<0.05) than the OVX rats; in contrast, bone volume fraction (BVF), trabecular thickness (Tb·Th.), trabecular number (Tb·N.), and bone mineral density (BMD) were significantly higher in the TBD-treated rats (P<0.05). Multivariate and univariate analysis showed that OVX resulted in significant alterations in the concentrations of 105 metabolites and 11 metabolic pathways (P<0.05); in addition, 26 potential biomarkers were identified to investigate the progression of PMOP. Network pharmacology showed that major alterations in vitamin B6 metabolism were associated with the VDR target. Next, we validated the three crucial targets (VDR [P<0.01], HSD11B1 [P<0.01], and CYP19A1 [P<0.05]) by enzyme-linked immunosorbent assays (ELISAs) and demonstrated that the levels of these targets were elevated in the OVX group but reduced in the TBD-treatment group. Collectively, our results suggest that the interventional effects of TBD on OVX rats are likely to be associated with the down regulation of VDR. Our findings enhance our molecular understanding of the interventional effects of TBD on PMOP and will allow us to develop further TBD studies.