Causal Effect of Serum Magnesium on Osteoporosis and Cardiometabolic Diseases

Plastrum Testudinis Stimulates Bone Formation through Wnt/β-catenin Signaling Pathway Regulated by miR-214

OBJECTIVE

To investigate the Wnt signaling pathway and miRNAs mechanism of extracts of Plastrum Testudinis (PT) in the treatment of osteoporosis (OP).

METHODS

Thirty female Sprague Dawley rats were randomly divided into 5 groups by random number table method, including sham group, ovariectomized group (OVX), ovariectomized groups treated with high-, medium-, and low-dose PT (160, 80, 40 mg/kg per day, respectively), with 6 rats in each group. Except for the sham group, the other rats underwent bilateral ovariectomy to simulate OP and received PT by oral gavage for 10 consecutive weeks. After treatment, bone mineral density was measured by dual-energy X-ray absorptiometry; bone microstructure was analyzed by micro-computed tomography and hematoxylin and eosin staining; and the expressions of osteogenic differentiation-related factors were detected by immunochemistry, Western blot, and quantitative polymerase chain reaction. In addition, Dickkopf-1 (Dkk-1) was used to inhibit the Wnt signaling pathway in bone marrow mesenchymal stem cells (BMSCs) and miRNA overexpression was used to evaluate the effect of miR-214 on the osteogenic differentiation of BMSCs. Subsequently, PT extract was used to rescue the effects of Dkk-1 and miR-214, and its impacts on the osteogenic differentiation-related factors of BMSCs were evaluated.

RESULTS

PT-M and PT-L significantly reduced the weight gain in OVX rats (P<0.05). PT also regulated the bone mass and bone microarchitecture of the femur in OVX rats, and increased the expressions of bone formation-related factors including alkaline phosphatase, bone morphogenetic protein type 2, collagen type I alpha 1, and runt-related transcription factor 2 when compared with the OVX group (P<0.05 or P<0.01). Meanwhile, different doses of PT significantly rescued the inhibition of Wnt signaling pathway-related factors in OVX rats, and increased the mRNA or protein expressions of Wnt3a, β-catenin, glycogen synthase kinase-3β, and low-density lipoprotein receptor-related protein 5 (P<0.05 or P<0.01). PT stimulated the osteogenic differentiation of BMSCs inhibited by Dkk-1 and activated the Wnt signaling pathway. In addition, the expression of miR-214 was decreased in OVX rats (P<0.01), and it was negatively correlated with the osteogenic differentiation of BMSCs (P<0.01). MiR-214 mimic inhibited Wnt signaling pathway in BMSCs (P<0.05 or P<0.01). Conversely, PT effectively counteracted the effect of miR-214 mimic, thereby activating the Wnt signaling pathway and stimulating osteogenic differentiation in BMSCs (P<0.05 or P<0.01).

CONCLUSION

PT stimulates bone formation in OVX rats through β-catenin-mediated Wnt signaling pathway, which may be related to inhibiting miR-214 in BMSCs.

Mapping the role of macro and micronutrients in bone mineral density: a comprehensive Mendelian randomization study

BACKGROUND

Macro and micronutrients may play an important role in osteoporosis development; however, observational studies have yielded inconsistent results. Clarifying these associations is vital to the development of nutritional recommendations aimed at preventing osteoporosis.

METHODS

Utilizing the largest available genome-wide association study (GWAS) summary statistics to date, we performed a two-sample Mendelian randomization (MR) analysis to investigate the causal effects of energy-adjusted macronutrient intake (fat, protein, carbohydrate, and sugar) and circulating levels of 20 micronutrients (ten each for vitamins and minerals) on heel estimated bone mineral density (eBMD), a promising marker for osteoporosis risk and fracture susceptibility. Sensitivity, sex-specific, and one-sample MR analyses were applied to further validate and annotate the results.

RESULTS

Among all nutrients, four genetically predicted circulating levels of micronutrients were suggestively associated with eBMD (vitamin A: β IVW = - 0.054, PIVW = 3.70 × 10-2; vitamin B12: β IVW = - 0.020, PIVW = 3.71 × 10-6; vitamin E: β IVW = 0.277, PIVW = 3.22 × 10-2; selenium: β IVW = 0.023, PIVW = 5.37 × 10-3; all Pintercept > 0.05). All these results were also considered robust, as sensitivity analyses yielded directionally consistent results. However, only the causal effects of vitamin B12 and selenium on eBMD remained significant after Bonferroni correction and were not confounded by obesity, smoking status, or alcohol consumption. Sex-specific analysis revealed a male-specific causal association between vitamin E and eBMD ( β IVW = 0.275, PIVW = 9.81 × 10-14). Additionally, using individuallevel data from the UK Biobank cohort, one-sample MR analysis found no causal relationships between diet-derived nutrient intake and eBMD in the overall population, as well as in the females or the males.

CONCLUSIONS

Our findings suggest that appropriate levels of plasma vitamin B12 and adequate levels of serum selenium are crucial for delaying bone loss and promoting bone health, emphasizing the need for nutritional recommendations to maintain optimal levels of these nutrients to promote eBMD and prevent osteoporosis.

Association between plain water intake and the risk of osteoporosis among middle-aged and elderly people in the United States: a cross-sectional study

Background

The connection between plain water intake (PWI) and osteoporosis risk is still unclear. The investigation aimed to identify the relationship between PWI and osteoporosis risk in middle-aged and elderly individuals in the United States (US).

Methods

This cross-sectional study was conducted among participants aged 50 years and older in the following waves of the National Health and Nutrition Examination Survey (NHANES): 2007-2008, 2009-2010, 2013-2014, and 2017-2018. The relationship between PWI and osteoporosis risk was examined by multivariable logistic regression models, accompanied by subgroup analyses and interaction tests. Smooth curve fitting and threshold effect analysis were utilized.

Results

The present investigation included 6,686 participants. In accordance with the fully adjusted model, individuals in the highest PWI tertile had a significantly reduced risk of osteoporosis in contrast to those in the lowest tertile [odds ratio (OR) = 0.62; 95% confidence interval (CI): 0.49-0.77; P for trend<0.001]. After adjusting for all covariates, a higher PWI was linked to a decreased risk of osteoporosis (OR = 0.92; 95% CI: 0.86-0.98; p = 0.008). No significant interactions were detected in the subgroup analyses for age, gender, race, body mass index, diabetic history, hypertension status, smoking history, consumption of prednisone or cortisone, or moderate or strenuous activity (all P for interaction>0.05). Smooth curve fitting and threshold effect analysis revealed that when PWI was less than 1,220 mL/day, there was a significant negative connection between PWI and osteoporosis risk (OR = 0.79; 95% CI: 0.70-0.89; p < 0.001); nevertheless that association was not significant when PWI was greater than 1,220 mL/day (OR = 1.06; 95% CI: 0.95-1.17; p = 0.288).

Conclusion

The outcomes of our investigation indicated that among middle-aged and older US adults, a higher PWI was connected with a moderately reduced osteoporosis risk. Managing PWI might reduce the osteoporosis risk.

Efficacy of magnetic therapy for osteoporotic patients: A meta-analysis of randomized controlled studies

BACKGROUND

Magnetic therapy may have some potential in treating osteoporosis, and this meta-analysis aims to study the efficacy of magnetic therapy for osteoporotic patients.

METHODS

We have searched several databases including PubMed, EMbase, Web of Science, EBSCO and Cochrane library databases, and selected the randomized controlled trials comparing the efficacy of magnetic therapy for osteoporotic patients. This meta-analysis was conducted using the random-effect or fixed-effect model based on the heterogeneity.

RESULTS

Five randomized controlled trials were included in this meta-analysis. Compared with sham procedure in osteoporotic patients, magnetic therapy was associated with significantly increased bone mineral density (standard mean difference [SMD] = 2.39; 95% confidence interval [CI] = 0.27-4.51; P = .03), decreased pain scores (mean difference [MD] = -0.86; 95% CI = -1.04 to -0.67; P < .00001), and calcium (MD = -0.61; 95% CI = -0.92 to -0.29; P = .0002), but revealed no influence on phosphate (MD = 0.07; 95% CI = -0.30 to 0.44; P = .71), osteocalcin (SMD = 0.65; 95% CI = -2.87 to 4.17; P = .72), or ALP (SMD = -0.43; 95% CI = -0.92 to 0.07; P = .09).

CONCLUSIONS

Magnetic therapy may be effective for the treatment of osteoporotic patients.

Metal ions: the unfading stars of bone regeneration-from bone metabolism regulation to biomaterial applications

In recent years, bone regeneration has emerged as a remarkable field that offers promising guidance for treating bone-related diseases, such as bone defects, bone infections, and osteosarcoma. Among various bone regeneration approaches, the metal ion-based strategy has surfaced as a prospective candidate approach owing to the extensive regulatory role of metal ions in bone metabolism and the diversity of corresponding delivery strategies. Various metal ions can promote bone regeneration through three primary strategies: balancing the effects of osteoblasts and osteoclasts, regulating the immune microenvironment, and promoting bone angiogenesis. In the meantime, the complex molecular mechanisms behind these strategies are being consistently explored. Moreover, the accelerated development of biomaterials broadens the prospect of metal ions applied to bone regeneration. This review highlights the potential of metal ions for bone regeneration and their underlying mechanisms. We propose that future investigations focus on refining the clinical utilization of metal ions using both mechanistic inquiry and materials engineering to bolster the clinical effectiveness of metal ion-based approaches for bone regeneration.

Magnesium Deficiency and Cardiometabolic Disease

Magnesium (Mg²⁺) has many physiological functions within the body. These include important roles in maintaining cardiovascular functioning, where it contributes to the regulation of cardiac excitation-contraction coupling, endothelial functioning and haemostasis. The haemostatic roles of Mg²⁺ impact upon both the protein and cellular arms of coagulation. In this review, we examine how Mg²⁺ homeostasis is maintained within the body and highlight the various molecular roles attributed to Mg²⁺ in the cardiovascular system. In addition, we describe how nutritional and/or disease-associated magnesium deficiency, seen in some metabolic conditions, has the potential to influence cardiac and vascular outcomes. Finally, we also examine the potential for magnesium supplements to be employed in the prevention and treatment of cardiovascular disorders and in the management of cardiometabolic health.

Carboxymethyl chitosan-alginate enhances bone repair effects of magnesium phosphate bone cement by activating the FAK-Wnt pathway

There is a continuing need for artificial bone substitutes for bone repair and reconstruction, Magnesium phosphate bone cement (MPC) has exceptional degradable properties and exhibits promising biocompatibility. However, its mechanical strength needs improved and its low osteo-inductive potential limits its therapeutic application in bone regeneration. We functionally modified MPC by using a polymeric carboxymethyl chitosan-sodium alginate (CMCS/SA) gel network. This had the advantages of: improved compressive strength, ease of handling, and an optimized interface for bioactive bone in-growth. The new composites with 2% CMCS/SA showed the most favorable physicochemical properties, including mechanical strength, wash-out resistance, setting time, injectable time and heat release. Biologically, the composite promoted the attachment and proliferation of osteoblast cells. It was also found to induce osteogenic differentiation in vitro, as verified by expression of osteogenic markers. In terms of molecular mechanisms, data showed that new bone cement activated the Wnt pathway through inhibition of the phosphorylation of β-catenin, which is dependent on focal adhesion kinase. Through micro-computed tomography and histological analysis, we found that the MPC-CMCS/SA scaffolds, compared with MPC alone, showed increased bone regeneration in a rat calvarial defect model. Overall, our study suggested that the novel composite had potential to help repair critical bone defects in clinical practice.

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CMCS/SA improves the mechanical strength of MPC while minimizing tissue damage.

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The MPC-CMCS/SA composite is easily manipulable for clinical application.

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MPC-CMCS/SA has good biocompatibility, and is easier for cell adhesion and proliferation.

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The MPC-CMCS/SA composite enhances osteogenic differentiation in vitro through the integrin-FAK-Wnt axis.

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The MPC-CMCS/SA composite enhances critical bone defect repair in vivo.

Subclinical Cardiovascular Disease Markers in Relation to Serum and Dietary Magnesium in Individuals from the General Population: The KORA-MRI Study

Several studies have implied a role of magnesium in the development of cardiovascular disease (CVD). Thus, magnesium might serve as a potential risk marker for early CVD. Therefore, we investigated the association of serum magnesium and dietary magnesium intake with markers of subclinical CVD in a population-based study. We used cross-sectional data from the sub-study of the Cooperative Health Research in the Region of Augsburg (KORA-FF4). Markers of subclinical CVD, namely, left and right ventricular structure and function and carotid plaque and carotid wall thickness, were derived by magnetic resonance imaging (MRI). Multivariable-adjusted regression models were applied to assess the relationship between serum and dietary magnesium and MRI-derived subclinical CVD markers. Among 396 included participants (mean age: 56.3 ± 9.2 years; 57.8% male), 181 (45.7%) had low serum magnesium levels (<2.07 mg/dL). Among 311 subjects with complete dietary data (mean age: 56.3 ± 9.1 years; 56.3% male), 154 (49.5%) had low dietary magnesium intake (≤155.2 mg/1000 kcal/day). Serum and dietary magnesium were not correlated (p-value = 0.5). Serum magnesium was significantly associated with presence of carotid plaque (OR 1.62, p-value 0.033). Dietary magnesium was associated with higher left ventricular end-systolic and end-diastolic volume (0.04 mL/m2, 0.06 mL/m2; p-value 0.011, 0.013, respectively), and also with a decrease in left ventricular remodeling index and mean diastolic wall thickness (−0.001 g/mL/m2, −0.002 mm/m2; p-value 0.004, 0.029, respectively). In summary, there was no consistent association of serum and dietary magnesium with imaging markers of subclinical CVD.

Mendelian randomization analysis of the causal association of bone mineral density and fracture with multiple sclerosis

Multiple sclerosis (MS) is a neurodegenerative disorder and an autoimmune disease. Until now, observational studies have indicated the association of bone mineral density (BMD) and fracture with the risk of MS. However, these studies indicated inconsistent findings. Until now, genome-wide association studies (GWAS) have been conducted in BMD, fracture, and MS, which provide large-scale datasets to investigate the causal association of BMD and fracture with the risk of MS using the Mendelian randomization (MR) study. Here, we performed an MR study to clarify the causal association between BMD/fracture and the risk of MS using large-scale publicly available GWAS datasets from BMD, fracture, and MS. We first evaluated the bidirectional causal effects of BMD and MS. The main analysis method inverse-variance weighted (IVW) showed no significant causal effect of BMD on the risk of MS (β = 0.058, and p = 1.98E-01), and MS on the risk of BMD (β = −0.001, and p = 7.83E-01). We then evaluated the bidirectional causal effects of fracture and MS. However, we only identified a significant causal effect of fracture on the risk of MS using IVW (β = −0.375, p = 0.002), but no significant causal effect of MS on the risk of the fracture using IVW (β = 0.011, p = 2.39E-01). Therefore, our main analysis method IVW only found a significant causal effect of fracture on MS using the threshold for the statistically significant association p < 0.05/4 = 0.0125. Meanwhile, multivariable MR analyses showed that the causal effect of fracture on MS was independent of smoking, drinking, and obesity, but dependent on BMD. In summary, our MR analysis demonstrates that genetically increased fracture may reduce the risk of MS. Our findings should be further verified and the underlying mechanisms should be further evaluated by future studies.

Causal associations of circulating adiponectin with cardiometabolic diseases and osteoporotic fracture

Circulating adiponectin shows some relationships with the occurrence of cardiometabolic diseases and osteoporotic fracture, but little is known about their causal associations. This two-sample Mendelian randomization (MR) study aims to explore the causal roles of circulating adiponectin in cardiometabolic diseases and osteoporotic fracture. We used 15 single nucleotide polymorphisms associated with circulating adiponectin as the instrumental variables. Inverse variance weighted, weighted median and MR-Egger regression methods were applied to study the causal associations. The results found that high circulating adiponectin was causally associated with reduced risk of type 2 diabetes (beta-estimate: -0.030, 95% CI: -0.048 to -0.011, SE: 0.009, P-value = 0.002) and may be the risk factor of coronary artery disease (beta-estimate: 0.012, 95% CI: 0.001 to 0.023, SE: 0.006, P-value = 0.030). No causal associations were seen between circulating adiponectin and other outcomes including heart failure, atrial fibrillation, cerebral ischemia, intracerebral hemorrhage or osteoporotic fracture. This study found the potential causal roles of high circulating adiponectin in reduced risk of type 2 diabetes and increased risk of coronary artery disease, which may help prevent and treat these two diseases.

Mg-HA-C/C Composites Promote Osteogenic Differentiation and Repair Bone Defects Through Inhibiting miR-16

The hydroxyapatite (HA) coating on carbon/carbon (C/C) is reasonable and feasible to obtain bone graft materials with appropriate mechanical and biological properties. However, improvement of the physical and chemical properties of HA-C/C composites to promote bone regeneration and healing remains a challenge. In our present study, the HA coatings on C/C with magnesium (Mg) (Mg-HA-C/C) composites were synthesized that Ca (NO3)2, Mg (NO3)2, and NH4H2PO4 were mixed and coatings were made by electromagnetic induction deposition’s heating. As determined with in vitro experiments, Mg-HA-C/C composites containing 10 and 20% Mg decreased miR-16 levels, increased cell viability, elevated the levels of osteogenesis-related genes, and promoted osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) seeded on their surfaces. In a rat model of skull defects, compared to the control group, at 4 and 12 weeks after the operation, the bone volume fraction (BV/TV) of Mg-HA-C/C composite group was increased by 8.439 ± 2.681% and 23.837 ± 7.845%, as well as the trabecular thickness (Tb.Th) was 56.247 ± 24.238 μm and 114.911 ± 34.015 μm more. These composites also increased the levels of ALP and RUNX2 in skull. The Mg-HA-C/C composite-enhanced bone regeneration and healing were blocked by in situ injection of an miR-16 mimic lentivirus vector. Thus, Mg-HA-C/C composites promote osteogenic differentiation and repair bone defects through inhibiting miR-16.

Causal Roles of Sleep Duration in Osteoporosis and Cardiometabolic Diseases: A Mendelian Randomization Study

Sleep duration suggests some association with osteoporosis and cardiometabolic diseases, but it is unknown if these associations are causal or confounded. In this two-sample Mendelian randomization (MR) study, we included the largest genome-wide association studies (GWASs) associated with sleep duration and the outcome measures of osteoporosis and cardiometabolic diseases. Finally, 25 single nucleotide polymorphisms (SNPs) associated with short sleep duration and 7 SNPs associated with long sleep duration obtained the genome-wide significance (P < 5 × 10^-8) and were used as instrumental variables. Genetic predisposition to short sleep duration was strongly associated with increased risk of coronary artery disease (beta-estimate: 0.199, 95% confidence interval CI: 0.081 to 0.317, standard error SE:0.060, P value = 0.001) and heart failure (beta-estimate: 0.145, 95% CI: 0.025 to 0.264, SE:0.061, P value = 0.017), which were both confirmed by the sensitivity analyses. Both short and long sleep duration may reduce the estimated bone mineral density (eBMD, beta-estimate: -0.086, 95% CI: -0.141 to -0.031, SE:0.028, P value = 0.002 for short sleep duration; beta-estimate: -0.080, 95% CI: -0.120 to -0.041, SE:0.020, P value < 0.0001 for long sleep duration). There was limited evidence of associations between sleep duration and fracture, type 2 diabetes, atrial fibrillation, fasting glucose, fasting insulin, or HbA1c. This study provides robust evidence that short sleep duration is causally associated with high risk of coronary artery disease and heart failure and suggests that short sleep duration should be avoided to prevent these two cardiovascular diseases. Short and long sleep duration show some MR association with reduced eBMD, which indicates that both short and long sleep duration may be prevented to reduce the incidence of osteoporosis.