Vitamin D inhibits bone loss in mice with thyrotoxicosis by activating the OPG/RANKL and Wnt/β-catenin signaling pathways

A Meta-Analysis Study to Define Variations in Murine Long Bone Biomechanical Testing

A systematic literature search and meta-analysis were performed to evaluate the variability in biomechanical testing of murine long bones, specifically focused on point-bending tests of mice femora. Due to the lack of standardized protocols for these tests, the assessment quantifies the heterogeneity in reported mechanical properties across existing literature. This study followed preferred reporting items for systematic reviews and meta-analyses (PRISMA) and strengthening the reporting of observational studies in epidemiology (STROBE) guidelines to search publicly available databases for relevant studies. After title and abstract screening, full-text reviews identified 73 articles meeting the inclusion criteria. Data was extracted from these studies, including stiffness, maximum load, modulus, and ultimate stress values for both three-point and four-point bending tests. The data were analyzed through ANOVA and metaregression to assess variability caused by age, sex, and genetic strain. The reviewers also assessed the quality of the included studies. The meta-analysis revealed significant heterogeneity in reported mechanical properties, with I2 values ranging from 72% to 100% in the three point-bend tests of pooled genetic strains. This heterogeneity persisted even after accounting for age, sex, and genetic strain differences. The review concludes that nonstandardized testing setups are the likely major source of the observed variability in reported data more than the population characteristics of the mice, highlighting the need for more consistent testing methodologies in future studies.

The Role of the Receptor Activator of Nuclear Factor Kappa-B Ligand/Osteoprotegerin Ratio in Vascular Diseases: A Therapeutic Approach

Cardiovascular and bone diseases contribute independently to mortality and global health. The exact mechanisms involved in the pathophysiology shared between bone and vascular diseases are not well defined. Endothelial cells and osteoblasts communicate during osteogenesis, thus establishing a connection between angiogenesis and osteogenesis. One shared mechanism may involve osteoprotegerin (OPG) and its ligand Receptor Activator of NF-κB Ligand (RANKL). The RANKL/OPG ratio is an important modulator for the skeletal, immunological, and vascular systems. OPG levels are elevated due to either osteogenic causes or inflammatory responses in the vasculature. The data obtained from clinical and in vitro studies support the role of the RANKL/OPG ratio as a potential marker for the progression of endothelial damage. Therefore, determining the therapeutic approaches for the targeting RANKL/OPG ratio and evaluating its usage as a biomarker in cardiovascular and bone pathophysiology are needed. By integrating the protective and disease-causing role of OPG with its ligand, this review outlines the role of the RANKL/OPG ratio at the molecular level. We also consider targeted therapeutic approaches.

Kouqiangjie formula alleviates diabetic periodontitis by regulating alveolar bone homeostasis via miR-29a-3p-mediated Dkk-1/Wnt/β-catenin signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetic periodontitis (DP) is a commonly co-occurring complication in diabetes patients characterized by advanced gum disease and bone resorption. Conventional treatment modalities often fail to adequately address the underlying biological disruptions caused by diabetes. The use of traditional medicinal formulas Kouqiangjie Formula (KQJF) potentially offers novel therapeutic approaches for DP, but its detailed regulatory mechanisms remain unclear.

AIM OF THE STUDY

This study aims to investigate the impacts of KQJF on osteoblastic activity and inflammatory responses in a rat model and in vitro pre-osteoblast cultures under conditions mimicking DP, focusing on the involvement of the miR-29a-3p-Dkk-1/Wnt/β-catenin signaling pathway.

MATERIALS AND METHODS

Using network pharmacological analysis, micro-CT, histological staining, and an array of molecular biology methodologies including Western blotting, RT-qPCR, and immunofluorescence, we investigated the systemic and cellular responses to KQJF treatment. Both in vivo (rat model) and in vitro (MC3T3-E1 pre-osteoblasts) models subjected to high glucose and lipopolysaccharide (HG + LPS) stress were used to simulate DP conditions.

RESULTS

Network pharmacological analyses, incorporating protein-protein interactions and pathway enrichment, disclosed that KQJF interacts with pathways crucial for inflammation and bone metabolism. Experimentally, KQJF significantly preserved alveolar bone architecture, reduced osteoclast activity, and dampened inflammatory cytokine production in DP rats. In pre-osteoblasts, KQJF enhanced cell viability, promoted cell cycle progression, and decreased apoptosis. At the molecular level, KQJF treatment upregulated miR-29a-3p and downregulated Dkk-1, thereby activating the Wnt/β-catenin pathway. The interventional studies with miR-29a-3p antagonists and Dkk-1 knockdown further confirmed the regulatory role of the miR-29a-3p/Dkk-1 axis in mediating the effects of KQJF.

CONCLUSION

KQJF mitigates the deleterious effects of DP by enhancing osteoblastic activity and reducing inflammatory responses, predominantly through the modulation of the miR-29a-3p-Dkk-1/Wnt/β-catenin signaling pathway. These discoveries underscore the therapeutic promise of KQJF in managing bone and inflammatory complications of DP, offering insights into its mechanism, and supporting its use in clinical settings.

The complex relationship between vitamin D and kidney stones: balance, risks, and prevention strategies

The association between vitamin D and kidney stones is characterized by a remarkable multi-dimensional complexity involving numerous physiological and metabolic pathways. Vitamin D is pivotal in maintaining calcium-phosphorus metabolic homeostasis and bone health. However, fluctuations in its intake, whether excessive or insufficient, May potentially increase the risk of kidney stones. Vitamin D exerts its influence on kidney stone formation indirectly by increasing the efficiency of intestinal calcium absorption and regulating renal calcium excretion. Moreover, there is a robust correlation between various states of vitamin D, particularly its active form, 1,25-dihydroxyvitamin D, and the development of numerous kidney stones. This finding underscores the necessity of individualized medical treatment in vitamin D supplementation and kidney stone prevention. When developing treatment strategies, it is essential to consider the patient's genetic background, lifestyle, environmental factors, and overall health. To prevent the formation of kidney stones, it is recommended that patients adopt a comprehensive approach, which May include measures such as moderate sun exposure, dietary modification, moderate exercise, and weight management. These preventive measures are designed to maintain healthy calcium and phosphorus metabolism and reduce kidney stone formation risk. Future studies should aim to elucidate the detailed mechanisms of vitamin D metabolism, individual differences, and the role of genes in this process. Furthermore, the role of lifestyle interventions in preventing kidney stones requires greater attention. Moreover, the implementation of large-scale, long-term prospective studies and randomized controlled trials will facilitate the assessment of the actual effects of diverse vitamin D supplementation strategies, thereby providing a robust scientific foundation for advancing more precise prevention strategies and clinical guidelines.

Confronting the global obesity epidemic: investigating the role and underlying mechanisms of vitamin D in metabolic syndrome management

The escalating prevalence of MetS, driven by global obesity trends, underscores the urgent need for innovative therapeutic strategies. To gain a deeper understanding of the therapeutic potential of vitamin D in addressing MetS, we embarked on a targeted literature review that thoroughly examines the scientific underpinnings and pivotal discoveries derived from pertinent studies, aiming to unravel the intricate mechanisms through which vitamin D exerts its effects on MetS and its components. This article explores the multifunctional role of vitamin D in the management of MetS, focusing on its regulatory effects on insulin sensitivity, lipid metabolism, inflammation, and immune response. Through an extensive review of current research, we unveil the complex mechanisms by which vitamin D influences MetS components, highlighting its potential as a therapeutic agent. Our analysis reveals that vitamin D's efficacy extends beyond bone health to include significant impacts on cellular and molecular pathways critical to MetS. We advocate for further research to optimize vitamin D supplementation as a component of precision medicine for MetS, considering the safety concerns related to dosage and long-term use.

Alleviation of Glucocorticoid-Induced Osteoporosis in Rats by Ethanolic Reynoutria multiflora (Thunb.) Moldenke Extract

Secondary osteoporosis is frequently due to the use of high-dose glucocorticoids (GCs). The existing strategy for managing glucocorticoid-induced osteoporosis (GIOP) is considered insufficient and remains in a state of ongoing evolution. Therefore, it is crucial to develop more precise and effective agents for the treatment of GIOP. The constituents of Reynoutria multiflora (Thunb.) Moldenke, specifically Polygonum multiflorum (PM) Thunb, have previously shown promise in mitigating osteopenia. This study aimed to investigate the therapeutic effects of an ethanolic PM extract (PMR30) against GIOP in male rats. Prednisone (6 mg/kg/day, GC) was continuously administered to rats to induce GIOP, and they were subjected to treatment with or without ethanolic PMR30 for a duration of 120 days. Serum was collected for biochemical marker analysis. Bone histomorphometric, histological, and TUNEL analyses were performed on tibia samples. The protein expressions of LC3, Agt5, and Beclin 1 in the femur underwent examination through western blotting. Prolonged and excessive GC treatment significantly impeded bone formation, concomitant with reduced bone mass and body weight. It also suppressed OCN and OPG/RANKL in serum, and decreased Beclin 1 and LC3 in bone. Simultaneously, there was an elevation in bone resorption markers and apoptosis. Treatments with both high dose and low dose of PMR30 alleviated GIOP, stimulated bone formation, and upregulated OCN and OPG/RANKL, while suppressing TRACP-5b, CTX-I, and apoptosis. The impact of PMR30 possibly involves the enhancement of autophagy proteins (LC3, Agt5, and Beclin 1) and the inhibition of apoptosis within the bone. PMR30 holds promise as a prospective therapeutic agent for preventing and treating GIOP.

Modulation of the vitamin D/vitamin D receptor system in osteoporosis pathogenesis: insights and therapeutic approaches

Osteoporosis is a prevalent bone disorder characterized by low bone mineral density (BMD) and deteriorated bone microarchitecture, leading to an increased risk of fractures. Vitamin D (VD), an essential nutrient for skeletal health, plays a vital role in maintaining bone homeostasis. The biological effects of VD are primarily mediated through the vitamin D receptor (VDR), a nuclear receptor that regulates the transcription of target genes involved in calcium and phosphate metabolism, bone mineralization, and bone remodeling. In this review article, we conduct a thorough literature search of the PubMed and EMBASE databases, spanning from January 2000 to September 2023. Utilizing the keywords "vitamin D," "vitamin D receptor," "osteoporosis," and "therapy," we aim to provide an exhaustive overview of the role of the VD/VDR system in osteoporosis pathogenesis, highlighting the most recent findings in this field. We explore the molecular mechanisms underlying VDR's effects on bone cells, including osteoblasts and osteoclasts, and discuss the impact of VDR polymorphisms on BMD and fracture risk. Additionally, we examine the interplay between VDR and other factors, such as hormonal regulation, genetic variants, and epigenetic modifications, that contribute to osteoporosis susceptibility. The therapeutic implications of targeting the VDR pathway for osteoporosis management are also discussed. By bringing together these diverse aspects, this review enhances our understanding of the VD/VDR system's critical role in the pathogenesis of osteoporosis and highlights its significance as a potential therapeutic target.

Vitamin D3 Metabolism and Its Role in Temporomandibular Joint Osteoarthritis and Autoimmune Thyroid Diseases

The aim of this review was to present the metabolism of vitamin D3, as well as to discuss the role of vitamin D3 in bone metabolism, temporomandibular joint osteoarthritis (TMJ OA), and autoimmune thyroid diseases (AITD) on the basis of the literature. Vitamin D3 plays a significant role in human health, as it affects the calcium-phosphate balance and regulates the bone metabolism. Calcitriol impresses the pleiotropic effect on human biology and metabolism. Its modulative function upon the immune system is based on the reduction of Th1 cell activity and increased immunotolerance. Vitamin D3 deficiency may lead to an imbalance in the relationship between Th1/Th17 and Th2, Th17/Th reg, and is considered by some authors as one of the possible backgrounds of autoimmune thyroid diseases (AITD), e.g., Hashimoto's thyroiditis or Graves' disease. Moreover, vitamin D3, through its direct and indirect influence on bones and joints, may also play an important role in the development and progression of degenerative joint diseases, including temporomandibular joint osteoarthritis. Further randomized, double blind studies are needed to unequivocally confirm the relationship between vitamin D3 and abovementioned diseases and to answer the question concerning whether vitamin D3 supplementation may be used in the prevention and/or treatment of either AITD or OA diseases.

Vitamin D deficiency linked to abnormal bone and lipid metabolism predicts high-risk multiple myeloma with poorer prognosis

Purpose

Vitamin D deficiency is frequent in patients with multiple myeloma (MM), however, its prognostic relevance in MM was rather inconclusive. We first investigated the association of vitamin D deficiency with abnormal bone and lipid metabolism in newly diagnosed multiple myeloma (NDMM), and next assessed the impact of serum ratio of vitamin D to carboxy-terminal telopeptide of type I collagen (β-CTX) on progression-free survival (PFS) and overall free survival (OS) in patients with NDMM.

Methods

The data of 431 consecutive patients with NDMM at Beijing Jishuitan Hospital from September 2013 to December 2022 were collected and retrospectively reviewed through our electronic medical record system. The measurement of 25-hydroxyvitamin D in the blood is an indicator of an individual's overall vitamin D status.

Results

The serum levels of vitamin D were negatively correlated with β-CTX in NDMM patients. Of note, positive correlation between vitamin D and cholesterol levels in the serum was found in this study. The cohort (n = 431) was divided into two groups based on the serum ratio of vitamin D to β-CTX. Compared to the group with a higher vitamin D to β-CTX ratio, the group with a lower vitamin D to β-CTX ratio (n = 257, 60%) exhibited hypocholesterolemia, inferior PFS and OS, along with increased cases of ISS stage-III and R-ISS stage-III, a higher number of plasma cells in the bone marrow, and elevated serum calcium levels. Consistent with this, multivariate analysis confirmed that the vitamin D to β-CTX ratio was an independent unfavorable indicator for survival in NDMM patients.

Conclusion

Our data demonstrated the ratio of vitamin D to β-CTX in the serum is a unique biomarker for NDMM patients to identify the high-risk cases with poor prognosis, which is superior to vitamin D itself for predicting PFS and OS in NDMM. Also, it is worth mentioning that our data on the connection between vitamin D deficiency and hypocholesterolemia might help clarify novel mechanistic aspects of myeloma development.