Pathogenic mechanisms of glucocorticoid-induced osteoporosis

Protective effects of Gumibao recipe on glucocorticoid-included bone microcirculatory endothelial cell injury and the underlying mechanism

OBJECTIVE

To investigate the protective effects of Gumibao recipe on glucocorticoid-included bone microcirculatory endothelial cell (BMEC) injury, and elucidate the possible underlying mechanism.

METHODS

BMECs were treated with different concentrations of hydrocortisone at different time points, and the viability as well as migration of BMECs were evaluated; furthermore, the release of LDH, levels of VEGF, PAI-1, t-PA, and the content of NO by BMECs have been evaluated by commercially available kits; moreover, the expressions of eNOS, p-PI3K, p-Akt and p-mTOR in BMECs were examined by WB methods. Next, hydrocortisone treated BMECs were co-treated with Gumibao recipe, and the viability, migration and autophagy of BMECs were evaluated.

RESULTS

0.2 mg/ml and 0.3 mg/ml hydrocortisone significantly decreased viability and migration ability of BMECs, and also impeded the endothelial function of BMECs by decreasing the levels of VEGF, t-PA, the content of NO, and increasing the level of PAI-1. Gumibao medicated serum markedly increased the viability and migration of BMECs, and also increased the levels of VEGF, t-PA, the content of NO, meanwhile decreased the level of PAI-1 in 0.3 mg/ml hydrocortisone treated BMECs; moreover, glucocorticoids inhibited the autophagy of BMECs, and Gumibao recipe significantly increased the autophagy of BMECs; meanwhile, autophagy inhibitor 3-MA partially blocked the protective effects of Gumibao recipe. Finally, gumibao recipe partially abrogated the inhibitory effects of hydrocortisone on the activation of PI3K/Akt/mTOR singling, and these effects were further counteracted by PI3K and mTOR inhibitor NVP-BEZ235.

CONCLUSIONS

We reported for the first time the protective effects of Gumibao recipe on glucocorticoid-included BMECs injury, and the possible underlying mechanism may be regulating the autophagy of BMECs via PI3K/AKT/mTOR signaling pathway.

Fluid shear stress-mediated Piezo1 alleviates osteocyte apoptosis by activating the PI3K/Akt pathway

Glucocorticoid-induced osteoporosis serves as a primary cause for secondary osteoporosis and fragility fractures, representing the most prevalent adverse reaction associated with prolonged glucocorticoid use. In this study, to elucidate the impact and underlying mechanisms of fluid shear stress (FSS)-mediated Piezo1 on dexamethasone (Dex)-induced apoptosis, we respectively applied Dex treatment for 6 h, FSS at 9 dyne/cm2 for 30 min, Yoda1 treatment for 2 h, and Piezo1 siRNA transfection to intervene in MLO-Y4 osteocytes. Western blot analysis was used to assess the expression of Cleaved Caspase-3, Bax, Bcl-2, and proteins associated with the PI3K/Akt pathway. Additionally, qRT-PCR was utilized to quantify the mRNA expression levels of these molecules. Hoechst 33258 staining and flow cytometry were utilized to evaluate the apoptosis levels. The results indicate that FSS at 9 dyne/cm2 for 30 min significantly upregulates Piezo1 in osteocytes. Following Dex-induced apoptosis, the phosphorylation levels of PI3K and Akt are markedly suppressed. FSS-mediated Piezo1 exerts a protective effect against Dex-induced apoptosis by activating the PI3K/Akt pathway. Additionally, downregulating the expression of Piezo1 in osteocytes using siRNA exacerbates Dex-induced apoptosis. To further demonstrate the role of the PI3K/Akt signaling pathway, after intervention with the PI3K pathway inhibitor, the activation of the PI3K/Akt pathway by FSS-mediated Piezo1 in osteocytes was significantly inhibited, reversing the anti-apoptotic effect. This study indicates that under FSS, Piezo1 in MLO-Y4 osteocytes is significantly upregulated, providing protection against Dex-induced apoptosis through the activation of the PI3K/Akt pathway.

ED-71 promotes osseointegration of titanium implants in a rat model of GIOP by alleviating the effects of dexamethasone on bone remodeling in a SIRT1-dependent manner

OBJECTIVE

Glucocorticoid-induced osteoporosis (GIOP), a common complication of glucocorticoid usage, plays a critical role in the success of dental implant restoration by affecting osseointegration. Eldecalcitol (ED-71) prevents GIOP; however, its role in the osseointegration of implants under GIOP conditions remains elusive.

METHODS

Dexamethasone was used to establish a rat model of GIOP. Subsequently, mini-implant surgery was performed on the femur. GIOP rats were administered ED-71 via gavage to assess its role in the osseointegration of titanium implants under GIOP conditions. MC3T3-E1 and RAW264.7 cells were utilized to explore the molecular mechanism of ED-71 in ameliorating disorder of bone remodeling caused by dexamethasone.

RESULTS

The administration of ED-71 promoted the formation of newly formed woven bone and the resolution of inflammation around titanium implants. In vitro experiments indicated that ED-71 ameliorated dexamethasone-induced dysfunction of osteoblasts and osteoclasts by increasing the expression level of sirtuin 1 (SIRT1). Inhibition of SIRT1 by selisistat counteracts the regulatory effects of ED-71 on dexamethasone-induced disorder of bone remodeling. Molecular docking and Western blotting revealed that the neurogenic locus notch homolog protein and nuclear factor kappa B signaling pathways are essential for the effects of ED-71 on dexamethasone-induced disorder of bone remodeling.

CONCLUSION

ED-71 promoted implant osseointegration in a rat model of GIOP by alleviating the effects of dexamethasone on bone remodeling in a SIRT1-dependent manner.

MAGL blockade alleviates steroid-induced femoral head osteonecrosis by reprogramming BMSC fate in rat

The leading cause of steroid-induced femoral head osteonecrosis (ONFH) is the imbalance of bone homeostasis. Bone marrow-derived mesenchymal stem cell (BMSC) differentiation and fate are closely associated with bone homeostasis imbalance. Blocking monoacylglycerol lipase (MAGL) could effectively ameliorate ONFH by mitigating oxidative stress and apoptosis in BMSCs induced by glucocorticoids (GC). Nevertheless, whether MAGL inhibition can modulate the balance during BMSC differentiation, and therefore improve ONFH, remains elusive. Our study indicates that MAGL inhibition can effectively rescue the enhanced BMSC adipogenic differentiation caused by GC and promote their differentiation toward osteogenic lineages. Cannabinoid receptor 2 (CB2) is the direct downstream target of MAGL in BMSCs, rather than cannabinoid receptor 1(CB1). Using RNA sequencing analyses and a series of in vitro experiments, we confirm that the MAGL blockade-induced enhancement of BMSC osteogenic differentiation is primarily mediated by the phosphoinositide 3-kinases (PI3K)/ the serine/threonine kinase (AKT)/ (glycogen synthase kinase-3 beta) GSK3β pathway. Additionally, MAGL blockade can also reduce GC-induced bone resorption by directly suppressing osteoclastogenesis and indirectly reducing the expression of receptor activator of nuclear factor kappa-Β ligand (RANKL) in BMSCs. Thus, our study proposes that the therapeutic effect of MAGL blockade on ONFH is partly mediated by restoring the balance of bone homeostasis and MAGL may be an effective therapeutic target for ONFH.

Glucocorticoids disrupt longitudinal advance of cortical bone basic multicellular units in the rabbit distal tibia

Glucocorticoids (GCs) are the leading cause of secondary osteoporosis. The emerging perspective, derived primarily from 2D histological study of trabecular bone, is that GC-induced bone loss arises through the uncoupling of bone formation and resorption at the level of the basic multicellular unit (BMU), which carries out bone remodeling. Here we explore the impact of GCs on cortical bone remodeling in the rabbit model. Based upon the rapid reduction of bone formation and initial elevation of resorption caused by GCs, we hypothesized that the rate of advance (longitudinal erosion rate; LER) of cortical BMUs would be increased. To test this hypothesis we divided 20 female New Zealand White rabbits into four experimental groups: ovariohysterectomy (OVH), glucocorticoid (GC), OVH + GC and SHAM controls (n = 5 animals each). Ten weeks post-surgery (OVH or sham), and two weeks after the initiation of dosing (daily subcutaneous injections of 1.5 mg/kg of methylprednisolone sodium succinate in the GC-treated groups and 1 ml of saline for the others), the right tibiae were scanned in vivo using Synchrotron Radiation (SR) in-line phase contrast micro-CT at the Canadian Light Source. After an additional 2 weeks of dosing, the rabbits were euthanized and ex vivo images were collected using desktop micro-CT. The datasets were co-registered in 3D and LER was calculated as the distance traversed by BMU cutting-cones in the 14-day interval between scans. Counter to our hypothesis, LER was greatly reduced in GC-treated rabbits. Mean LER was lower in GC (4.27 μm/d; p < 0.001) and OVH + GC (4.19 μm/d; p < 0.001), while similar in OVH (40.13 μm/d; p = 0.990), compared to SHAM (40.44 μm/d). This approximately 90 % reduction in LER with GCs was also associated with an overall disruption of BMU progression, with radial expansion of the remodeling space occurring in all directions. This unexpected outcome suggests that GCs do not simply uncouple formation and resorption within cortical BMUs and highlights the value of the time-lapsed 4D approach employed.

Supplementation with carnosine, a food-derived bioactive dipeptide, alleviates dexamethasone-induced oxidative stress and bone impairment via the NRF2 signaling pathway

BACKGROUND

Carnosine, a natural bioactive dipeptide derived from meat muscle, possesses strong antioxidant properties. Dexamethasone, widely employed for treating various inflammatory diseases, raises concerns regarding its detrimental effects on bone health. This study aimed to investigate the protective effects of carnosine against dexamethasone-induced oxidative stress and bone impairment, along with its underlying mechanisms, utilizing chick embryos and a zebrafish model in vivo, as well as MC3T3-E1 cells in vitro.

RESULTS

Our findings revealed that carnosine effectively mitigated bone injury in dexamethasone-exposed chick embryos, accompanied by reduced oxidative stress. Further investigation demonstrated that carnosine alleviated impaired osteoblastic differentiation in MC3T3-E1 cells and zebrafish by suppressing the excessive production of reactive oxygen species (ROS) and enhancing the activity of antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GPX). Moreover, mechanistic studies elucidated that carnosine promoted the expression and nuclear translocation of nuclear factor erythroid 2-related factor 2 (NRF2), thereby facilitating the transcription of its downstream antioxidant response elements, including heme oxyense-1 (HO-1), glutamate cysteine ligase modifier (GCLM), and glutamate cysteine ligase catalytic (GCLC) to counteract dexamethasone-induced oxidative stress.

CONCLUSION

Overall, this study underscores the potential therapeutic efficacy of carnosine in mitigating oxidative stress and bone damage induced by dexamethasone exposure, shedding light on its underlying mechanism of action by activating the NRF2 signaling pathway. © 2024 Society of Chemical Industry.

CUL1 exacerbates glucocorticoid-induced osteoporosis by enhancing ASAP1 ubiquitination

BACKGROUND

Glucocorticoid-induced osteoporosis is a leading secondary cause of osteoporosis. Cullin-1 (CUL1) levels are abnormally elevated in patients with osteoporosis, but the underlying mechanism remains unclear. The purpose of this study was to elucidate the mechanism of action of CUL1 in a glucocorticoid (dexamethasone, Dex)-induced osteoporosis model.

METHODS

C57BL/6J mice were intraperitoneally injected with Dex to establish an osteoporosis model. Mouse femur bone injury and bone formation were detected using hematoxylin-eosin or Masson staining. Apoptosis and cell cycle distribution were determined by flow cytometry. Alkaline phosphatase (ALP) activity and calcified nodules were monitored using ALP and Alizarin Red S staining. The molecular mechanism was validated by co-immunoprecipitation (Co-IP) and ubiquitination assays.

RESULTS

CUL1 expression was enhanced in the Dex-induced osteoporosis mouse model. CUL1 silencing moderated the Dex-induced cell proliferation and osteogenesis inhibition. Moreover, CUL1 promoted the ubiquitination and degradation of ASAP1 via the SKP1-CUL1-F-box (SCF)-FBXW7 complex. CUL1 induced apoptosis and repressed osteogenesis by ASAP1. CUL1 silencing alleviated the Dex-induced osteoporosis in mice.

CONCLUSION

CUL1 suppressed osteoblast proliferation and osteogenesis by promoting ASAP1 ubiquitination via the SCF-FBXW7 complex in glucocorticoid-induced osteoporosis.

Significant decrease of osteoporosis and osteoporotic fractures in rheumatoid arthritis within a period of 24 years: experiences of a single centre

OBJECTIVES

Rheumatoid arthritis (RA) is associated with an increased risk for osteoporosis and osteoporotic fractures. Since the treatment of RA has improved significantly in recent years, we can expect RA-associated osteoporosis to decrease with good disease control. Therefore, we conducted a retrospective study to investigate whether the frequency of osteoporosis and osteoporotic fractures has changed during 24 years in RA.

METHODS

We analysed the data of 1.086 RA patients from the time of the first osteological assessment with bone mineral density (BMD) measurement and collection of osteologically important data during the years 1996 and 2019 at our clinic. According to the treatment period, the patients were divided into cohort 1 (investigation between 1996 and 2004; n=539) and cohort 2 (investigation between 2005 and 2019; n=547). The data of the two cohorts were compared, and predictors of BMD were analysed by linear regression analysis.

RESULTS

Prevalence of osteoporosis (28.3% vs 48.4%; p<0.001) as well as osteoporotic peripheral fractures (11.5% vs 21%; p<0.001) and vertebral fractures (6.6% vs 10.9%; p=0.011) were significantly lower and treatment with biologicals (19.7% vs 5.0%; p<0.001) significantly more common and glucocorticoid use was significantly less common (p=0.005) in cohort 2. In RA patients with a disease duration of more than 2 years, BMD was significantly higher under treatment with biologicals (p<0.001) despite increased cumulative glucocorticoid dosages (p<0.001).

CONCLUSION

Our study showed a significant decline in osteoporosis and osteoporotic fractures in RA for 24 years. This positive effect is associated with the more frequent use of biologicals in the years between 2005 and 2019.

Pulmonary delivery of cell membrane-derived nanovesicles carrying anti-miRNA155 oligonucleotides ameliorates LPS-induced acute lung injury

Acute lung injury (ALI) is a devastating inflammatory disease. MicroRNA155 (miR155) in alveolar macrophages and lung epithelial cells enhances inflammatory reactions by inhibiting the suppressor of cytokine signaling 1 (SOCS1) in ALI. Anti-miR155 oligonucleotide (AMO155) have been suggested as a potential therapeutic reagent for ALI. However, a safe and efficient carrier is required for delivery of AMO155 into the lungs for ALI therapy. In this study, cell membrane-derived nanovesicles (CMNVs) were produced from cell membranes of LA4 mouse lung epithelial cells and evaluated as a carrier of AMO155 into the lungs. For preparation of CMNVs, cell membranes were isolated from LA4 cells and CMNVs were produced by extrusion. Cholesterol-conjugated AMO155 (AMO155c) was loaded into CMNVs and extracellular vesicles (EVs) by sonication. The physical characterization indicated that CMNVs with AMO155c (AMO155c/CMNV) were membrane-structured vesicles with a size of ∼120 nm. The delivery efficiency and therapeutic efficacy of CMNVs were compared with those of EVs or polyethylenimine (25 kDa, PEI25k). The delivery efficiency of AMO155c by CMNVs was similar to that by EVs. As a result, the miR155 levels were reduced by AMO155c/CMNV and AMO155c/EV. AMO155c/CMNV were administered intratracheally into the ALI models. The SOCS1 levels were increased more efficiently by AMO155c/CMNV than by the others, suggesting that miR155 effectively was inhibited by AMO155c/CMNV. In addition, the inflammatory cytokines were reduced more effectively by AMO155c/CMNV than they were by AMO155c/EV and AMO155c/PEI25k, reducing inflammation reactions. The results suggest that CMNVs are a useful carrier of AMO155c in the treatment of ALI.

Global Trends in Research of Programmed Cell Death in Osteoporosis: A Bibliometric and Visualized Analysis (2000-2023)

Osteoporosis (OP) is a systemic metabolic bone disease that is characterized by decreased bone mineral density and microstructural damage to bone tissue. Recent studies have demonstrated significant advances in the research of programmed cell death (PCD) in OP. However, there is no bibliometric analysis in this research field. This study searched the Web of Science Core Collection (WoSCC) database for literature related to OP and PCD from 2000 to 2023. This study used VOSviewers 1.6.20, the "bibliometrix" R package, and CiteSpace (6.2.R3) for bibliometric and visualization analysis. A total of 2905 articles from 80 countries were included, with China and the United States leading the way. The number of publications related to PCD in OP is increasing year by year. The main research institutions are Shanghai Jiao Tong University, Chinese Medical University, Southern Medical University, Zhejiang University, and Soochow University. Bone is the most popular journal in the field of PCD in OP, and the Journal of Bone and Mineral Research is the most co-cited journal. These publications come from 14,801 authors, with Liu Zong-Ping, Yang Lei, Manolagas Stavros C, Zhang Wei, and Zhao Hong-Yan having published the most papers. Ronald S. Weinstein was co-cited most often. Oxidative stress and autophagy are the current research hot spots for PCD in OP. This bibliometric study provides the first comprehensive summary of trends and developments in PCD research in OP. This information identifies the most recent research frontiers and hot directions, which will provide a definitive reference for scholars studying PCD in OP.

Wnt signaling pathway in spinal cord injury: from mechanisms to potential applications

Spinal cord injury (SCI) denotes damage to both the structure and function of the spinal cord, primarily manifesting as sensory and motor deficits caused by disruptions in neural transmission pathways, potentially culminating in irreversible paralysis. Its pathophysiological processes are complex, with numerous molecules and signaling pathways intricately involved. Notably, the pronounced upregulation of the Wnt signaling pathway post-SCI holds promise for neural regeneration and repair. Activation of the Wnt pathway plays a crucial role in neuronal differentiation, axonal regeneration, local neuroinflammatory responses, and cell apoptosis, highlighting its potential as a therapeutic target for treating SCI. However, excessive activation of the Wnt pathway can also lead to negative effects, highlighting the need for further investigation into its applicability and significance in SCI. This paper provides an overview of the latest research advancements in the Wnt signaling pathway in SCI, summarizing the recent progress in treatment strategies associated with the Wnt pathway and analyzing their advantages and disadvantages. Additionally, we offer insights into the clinical application of the Wnt signaling pathway in SCI, along with prospective avenues for future research direction.

Application of 3D bioprinting technology apply to assessing Dangguiniantongtang (DGNT) decoctions in arthritis

The aim of this study was to develop a three-dimensional (3D) cell model in order to evaluate the effectiveness of a traditional Chinese medicine decoction in the treatment of arthritis. Chondrocytes (ATDC5) and osteoblasts (MC3T3-E1) were 3D printed separately using methacryloyl gelatin (GelMA) hydrogel bioinks to mimic the natural 3D cell environment. Both cell types showed good biocompatibility in GelMA. Lipopolysaccharide (LPS) was added to the cell models to create inflammation models, which resulted in increased expression of inflammatory factors IL-1β, TNF-α, iNOS, and IL-6, and decreased expression of cell functional genes such as Collagen II (COLII), transcription factor SOX-9 (Sox9), Aggrecan, alkaline phosphatase (ALP), RUNX family transcription factor 2 (Runx2), Collagen I (COLI), Osteopontin (OPN), and bone morphogenetic protein-2 (BMP-2). The created inflammation model was then used to evaluate the effectiveness of Dangguiniantongtang (DGNT) decoctions. The results showed that DGNT reduced the expression of inflammatory factors and increased the expression of functional genes in the cell model. In summary, this study established a 3D cell model to assess the effectiveness of traditional Chinese medicine (TCM) decoctions, characterized the gene expression profile of the inflammatory state model, and provided a practical reference for future research on TCM efficacy evaluation for arthritis treatment.

Therapeutic effects of ginsenosides on osteoporosis for novel drug applications

Osteoporosis (OP) is a metabolic bone disease with a high incidence rate worldwide. Its main features are decreased bone mass, increased bone fragility and deterioration of bone microstructure. It is caused by an imbalance between bone formation and bone resorption. Ginsenoside is a safe and effective traditional Chinese medicine (TCM) usually extracted from ginseng plants, having various therapeutic effects, of which the effect against osteoporosis has been extensively studied. We searched a total of 44 relevant articles with using keywords including osteoporosis, ginsenosides, bone mesenchymal cells, osteoblasts, osteoclasts and bone remodeling, all of which investigated the cellular mechanisms of different types of ginsenosides affecting the activity of bone remodeling by mesenchymal stem cells, osteoblasts and osteoclasts to counteract osteoporosis. This review describes the different types of ginsenosides used to treat osteoporosis from different perspectives, providing a solid theoretical basis for future clinical applications.

New insights into dairy management and the prevention and treatment of osteoporosis: The shift from single nutrient to dairy matrix effects-A review

Dairy is recognized as a good source of calcium, which is important for preventing osteoporosis. However, the relationship between milk and bone health is more complex than just calcium supplementation. It is unwise to focus solely on observing the effects of a single nutrient. Lactose, proteins, and vitamins in milk, as well as fatty acids, oligosaccharides, and exosomes, all work together with calcium to enhance its bioavailability and utilization efficiency through various mechanisms. We evaluate the roles of dairy nutrients and active ingredients in maintaining bone homeostasis from the perspective of the dairy matrix effects. Special attention is given to threshold effects, synergistic effects, and associations with the gut-bone axis. We also summarize the associations between probiotic/prebiotic milk, low-fat/high-fat milk, lactose-free milk, and fortified milk with a reduced risk of osteoporosis and discuss the potential benefits and controversies of these dairy products. Moreover, we examine the role of dairy products in increasing peak bone mass during adolescence and reducing bone loss in old age. It provides a theoretical reference for the use of dairy products in the accurate prevention and management of osteoporosis and related chronic diseases and offers personalized dietary recommendations for bone health in different populations.

A comprehensive review on glucocorticoids induced osteoporosis: A medication caused disease

Glucocorticoids (GCs) are steroid hormones that are extensively used in the treatment of autoimmune diseases, inflammation, and cancer. The major ill effect of administering GCs is that it has a deleterious effect on bone, which leads to GC-induced osteoporosis. GC therapy induces bone loss and is associated with the risk of nonvertebral and vertebral fractures, as it works in combination by increasing bone reabsorption and suppressing bone formation during the initial phase of therapy. It is seen and established that GC in excess or in low dose for 3 months or more can be a risk factor for fracture, and the risk increases with an increase in dose and duration of usage. The most common cause of secondary osteoporosis is the administration of GC inside the body to treat various diseases. The degree of bone loss is directly proportional to the GC dose and the exposure duration. The first step is to evaluate the patients' risk factors for the development of glucocorticoids that induce osteoporosis, which include the dose, duration of use, patient age, sex, previous fractures, and other medical conditions.

Osteoporotic osseointegration: therapeutic hallmarks and engineering strategies

Osteoporosis is a systemic skeletal disease caused by an imbalance between bone resorption and formation. Current treatments primarily involve systemic medication and hormone therapy. However, these systemic treatments lack directionality and are often ineffective for locally severe osteoporosis, with the potential for complex adverse reactions. Consequently, treatment strategies using bioactive materials or external interventions have emerged as the most promising approaches. This review proposes twelve microenvironmental treatment targets for osteoporosis-related pathological changes, including local accumulation of inflammatory factors and reactive oxygen species (ROS), imbalance of mitochondrial dynamics, insulin resistance, disruption of bone cell autophagy, imbalance of bone cell apoptosis, changes in neural secretions, aging of bone cells, increased local bone tissue vascular destruction, and decreased regeneration. Additionally, this review examines the current research status of effective or potential biophysical and biochemical stimuli based on these microenvironmental treatment targets and summarizes the advantages and optimal parameters of different bioengineering stimuli to support preclinical and clinical research on osteoporosis treatment and bone regeneration. Finally, the review addresses ongoing challenges and future research prospects.

Curcumin-loaded scaffolds in bone regeneration

In recent years, there has been a notable surge in the development of engineered bone scaffolds intended for the repair of bone defects. While autografts and allografts have traditionally served as the primary methods in bone tissue engineering, their inherent limitations have spurred the exploration of novel avenues in biomedical implant development. The emergence of bone scaffolds not only facilitates bone reconstruction but also offers a platform for the targeted delivery of therapeutic agents. There exists a pervasive interest in leveraging various drugs, proteins, growth factors, and biomolecules with osteogenic properties to augment bone formation, as the enduring side effects associated with current clinical modalities necessitate the pursuit of safer alternatives. Curcumin, the principal bioactive compound found in turmeric, has demonstrated notable efficacy in regulating the proliferation and differentiation of bone cells while promoting bone formation. Nevertheless, its utility is hindered by restricted water solubility and poor bioavailability. Strategies aimed at enhancing the solubility, stability, and bioavailability of curcumin, including formulation techniques such as liposomes and nanoparticles or its complexation with metals, have been explored. This investigation is dedicated to exploring the impact of curcumin on the proliferation, differentiation, and migration of osteocytes, osteoblasts, and osteoclasts.

Gli1+ Progenitors Mediate Glucocorticoid-Induced Osteoporosis In Vivo

For a wide range of chronic autoimmune and inflammatory diseases in both adults and children, synthetic glucocorticoids (GCs) are one of the most effective treatments. However, besides other adverse effects, GCs inhibit bone mass at multiple levels, and at different ages, especially in puberty. Although extensive studies have investigated the mechanism of GC-induced osteoporosis, their target cell populations still be obscure. Here, our data show that the osteoblast subpopulation among Gli1+ metaphyseal mesenchymal progenitors (MMPs) is responsive to GCs as indicated by lineage tracing and single-cell RNA sequencing experiments. Furthermore, the proliferation and differentiation of Gli1+ MMPs are both decreased, which may be because GCs impair the oxidative phosphorylation(OXPHOS) and aerobic glycolysis of Gli1+ MMPs. Teriparatide, as one of the potential treatments for GCs in bone mass, is sought to increase bone volume by increasing the proliferation and differentiation of Gli1+ MMPs in vivo. Notably, our data demonstrate teriparatide ameliorates GC-caused bone defects by targeting Gli1+ MMPs. Thus, Gli1+ MMPs will be the potential mesenchymal progenitors in response to diverse pharmaceutical administrations in regulating bone formation.

The Relationship Between Systemic Lupus Erythematosus and Osteoporosis Based on Different Ethnic Groups: a Two-Sample Mendelian Randomization Analysis

The previous observational studies could not overcome the effects of confounding variables and reverse causality. We aimed to determine whether there is a causal relationship between systemic lupus erythematosus and osteoporosis in East Asian and European populations, respectively, by two-sample Mendelian Randomization analysis. We obtained and downloaded data from publicly available genome-wide association study databases and analyses for East Asian and European populations, including systemic lupus erythematosus (SLE), osteoporosis (OP), multisite bone mineral density (BMD), and OP with fracture. After screening for instrumental single-nucleotide polymorphisms (SNPs) significantly correlated to SLE, the inverse-variance weighted (IVW) method was used for calculating the ratio and 95% confidence interval, besides utilizing MR-Egger, weighted median, and weighted mode to assess the robustness of the primary outcome. Moreover, multiple analyses, including MR-PRESSO, MR-Egger intercept, Cochran's Q test, as well as "leave-one-out" sensitivity, were used for evaluating horizontal pleiotropy, heterogeneity, and stability. Finally, we exchanged exposure and outcome and performed a reverse MR analysis. IVW (OR = 1.05, 95% CI = 1.01-1.09, P = 0.009) indicated a significant positive correlation between genetically predicted SLE and OP in East Asians. Furthermore, neither heterogeneity nor horizontal pleiotropy was observed. In Europe, there was no significant genetically predicted causal relation between SLE and OP. Bi-directional MR analysis showed no reverse causality between SLE and OP. In the East Asian population, genetically predicted SLE may have had a positive causal relationship with OP. In Europe, there is insufficient evidence for a potential causal relation between SLE and OP or BMD and fracture, and the correlations currently observed may be attributed to a variety of confounder variables.

The Potential of Exosomes for Osteoporosis Treatment: A Review

As a continuous process comprising bone resorption and formation, bone remodeling, plays an essential role in maintaining the balance of bone metabolism. One type of metabolic osteopathy is osteoporosis, which is defined by low bone mass and deteriorating bone microstructure. Osteoporosis patients are more likely to experience frequent osteoporotic fractures, which makes osteoporosis prevention and treatment crucial. A growing body of research has revealed that exosomes, which are homogenous vesicles released by most cell types, play a major role in mediating a number of pathophysiological processes, including osteoporosis. Exosomes may act as a mediator in cell-to-cell communication and offer a fresh perspective on information sharing. This review discusses the characteristics of exosomes and outlines the exosomes' underlying mechanism that contributes to the onset of osteoporosis. Recent years have seen a rise in interest in the role of exosomes in osteoporosis, which has given rise to innovative therapeutic approaches for the disease prevention and management.

Insights and implications of sexual dimorphism in osteoporosis

Osteoporosis, a metabolic bone disease characterized by low bone mineral density and deterioration of bone microarchitecture, has led to a high risk of fatal osteoporotic fractures worldwide. Accumulating evidence has revealed that sexual dimorphism is a notable feature of osteoporosis, with sex-specific differences in epidemiology and pathogenesis. Specifically, females are more susceptible than males to osteoporosis, while males are more prone to disability or death from the disease. To date, sex chromosome abnormalities and steroid hormones have been proven to contribute greatly to sexual dimorphism in osteoporosis by regulating the functions of bone cells. Understanding the sex-specific differences in osteoporosis and its related complications is essential for improving treatment strategies tailored to women and men. This literature review focuses on the mechanisms underlying sexual dimorphism in osteoporosis, mainly in a population of aging patients, chronic glucocorticoid administration, and diabetes. Moreover, we highlight the implications of sexual dimorphism for developing therapeutics and preventive strategies and screening approaches tailored to women and men. Additionally, the challenges in translating bench research to bedside treatments and future directions to overcome these obstacles will be discussed.

Comorbidity Burden in Severe and Nonsevere Asthma: A Nationwide Observational Study (FINASTHMA)

BACKGROUND

Asthma, affecting more than 330 million people worldwide, is associated with a high level of morbidity, mortality, and socioeconomic costs.

OBJECTIVE

In this cross-sectional study, we analyzed the comorbidity burden in patients with severe asthma compared with nonsevere asthma and investigated the role of corticosteroid use on the risk of comorbidities.

METHODS

All adults (≥18 y) with a diagnosis of asthma (International Classification of Diseases-10th revision code J45.x) between 2014 and 2017 were identified and data were collected until 2018 from Finnish nationwide registers. Asthma was defined as continuously or transiently severe or nonsevere based on annual dispensed inhaled corticosteroids (ICS), oral corticosteroids (OCS), and hospitalizations.

RESULTS

Of 193,730 adult identified patients diagnosed with asthma, 86.3% had nonsevere, 8.1% transiently severe, and 5.6% continuously severe asthma. Excess prevalence of pneumonia was observed in continuously (22%) and transiently severe (14%) compared with nonsevere patients after adjusting for age and sex. Cataract, osteoporosis, obesity, heart failure, and atrial fibrillation were also more frequent in severe asthma patients. The ICS and/or OCS use contributed to the risk of several comorbidities in a dose-dependent manner, particularly pneumonia, osteoporosis, obesity, heart failure, and atrial fibrillation. High OCS use and the presence of comorbidities were associated with increased health care resource use.

CONCLUSIONS

Patients with severe asthma have a high burden of comorbidities, especially pneumonia. Many of the comorbidities have a strong dose-dependent association with ICS and OCS treatment, suggesting that corticosteroid doses should be carefully evaluated in clinical practice.

The Role of Herbal Medicine in Modulating Bone Homeostasis

Osteoporosis and other bone diseases are a major public health concern worldwide. Current pharmaceutical treatments for bone disorders have limitations, driving interest in complementary herbal medicines that can help maintain bone health. This review summarizes the scientific evidence for medicinal herbs that modulate bone cell activity and improve bone mass, quality and strength. Herbs with osteogenic, anti-osteoporotic, and anti-osteoclastic effects are discussed, including compounds and mechanisms of action. Additionally, this review examines the challenges and future directions for translational research on herbal medicines for osteoporosis and bone health. While preliminary research indicates beneficial bone bioactivities for various herbs, rigorous clinical trials are still needed to verify therapeutic efficacy and safety. Further studies should also elucidate synergistic combinations, bioavailability of active phytochemicals, and precision approaches to match optimal herbs with specific etiologies of bone disease. Advancing evidence- based herbal medicines may provide novel alternatives for promoting bone homeostasis and treating skeletal disorders.

Demystifying the Risk Factors and Preventive Measures for Osteoporosis

Background

Osteoporosis is a major health problem, globally. It is characterized by structural bone weakness leading to an increased risk of fragility fractures. These fractures commonly affect the spine, hip and wrist bones. Consequently, Osteoporosis related proximal femur and vertebral fractures represent a substantial, growing social and economic burden on healthcare systems worldwide. Indentification of the risk factors, clinical risk assessment, utilization of risk assessment tools and appropriate management that play a crucial role in reducing the burden of Osteoporosis by tackling modifiable risk factors.

Methods

This chapter explores various risk factors that are associated with Osteoporosis and provides an overview of various clinical and diagnostic risk assessment tools with a particular emphasis on evidence-based strategies for their prevention.

Conclusion

The role of emerging technologies such as Artificial Intelligence (AI) and perspectives such as newer diagnostic modalities, monitoring and surveillance approaches in prevention of risk factors in the pathogenesis of Osteoporosis is highlighted.

Causal relationship between chronic obstructive pulmonary disease and BMD at different sites: A bidirectional Mendelian randomization study

Observational studies have demonstrated a correlation between chronic obstructive pulmonary disease (COPD) and osteoporosis (OP). However, it is unclear whether there is genetic causality between COPD and bone mineral density (BMD) reduction at different sites. This study assessed the causal relationship between COPD and BMD in various anatomical locations. Data associated with COPD and BMD were obtained from published genome-wide association studies (GWAS). We selected single nucleotide polymorphisms (SNPs) that were strongly associated with COPD and BMD could serve as instrumental variables for the analysis. Inverse variance weighted, MR-Egger and weighted median were manipulated to evaluate causality. Subsequently, we conducted heterogeneity tests using Cochran Q test and tested for pleiotropy using the MR-Egger intercept. We performed leave-one-out sensitivity analysis to assess the robustness of the results. Additionally, we obtained more accurate causal genetic associations by removing any pleiotropic outlying SNPs and performed Mendelian randomization (MR) analysis with the remaining data. Our findings established that COPD was negatively associated with Heel-BMD (odds ratio[OR] = 0.978, 95% confidence interval [CI] = 0.966, 0.990, P = .0003) but not LS-BMD (OR = 0.981, 95% CI: 0.943, 1.020, P = .335), FA-BMD (OR = 0.984, 95% CI: 0.927, 1.046, P = .616), and FN-BMD (OR = 0.981, 95% CI: 0.950, 1.014, P = .249). In reverse MR analysis, the results showed no significant causal effect of BMD at different sites on COPD. The results were proved to be dependable and steady by sensitivity, heterogeneity, and pleiotropy analysis. We found that COPD increases the risk of decreased heel BMD, however, there is no evidence that the loss of BMD increases the risk of COPD.

Management of Adrenal Cortical Adenomas: Assessment of Bone Status in Patients with (Non-Functioning) Adrenal Incidentalomas

Our aim is to analyse the bone profile in adults with (non-functioning) adrenal incidentalomas (AIs), specifically addressing the impact of autonomous cortisol secretion (ACS). This narrative review, based on a PubMed search from inception to February 2023 (case reports, non-ACS, and other secondary causes of osteoporosis were excluded), included 40 original studies, a total of 3046 patients with female prevalence (female:male ratio of 1921:1125), aged between 20.5 and 95.5 years old. This three decade-based analysis showed that 37 studies provided dual-energy X-ray absorptiometry (DXA) information; another five studies reports results on bone micro-architecture, including trabecular bone score (TBS), spinal deformity index, and high-resolution peripheral quantitative computed tomography; 20 cohorts included data on bone turnover markers (BTMs), while four longitudinal studies followed subjects between 1 and 10.5 years old (surgical versus non-adrenalectomy arms). Post-dexamethasone suppression test (DST) cortisol was inversely associated with bone mineral density (BMD). TBS predicted incidental vertebral fractures (VFx) regardless of BMD, being associated with post-DST cortisol independently of age and BMD. Low BTMs were identified in ACS, but not all studies agreed. An increased prevalence of ACS-related osteoporosis was confirmed in most studies (highest prevalence of 87.5%), as well as of VFx, including in pre-menopause (42.5%), post-menopause (78.6%), and male patients (72.7%) depending on the study, with a 10-fold increased incidental VFx risk up to a 12-fold increased risk after a 2-year follow-up. No specific medication against osteoporosis is indicated in ACS, but adrenalectomy (according to four studies) should be part of the long-term strategy. This bone profile case sample-based study (to our knowledge, one of the largest of its kind) showed that AIs, including the subgroup designated as having ACS, embraces a large panel of osseous complications. The level of evidence remains far from generous; there are still no homogenous results defining ACS and identifying skeletal involvement, which might be a consequence of different investigation clusters underling adrenal and bone assessments over time. However, bone status evaluations and associated therapy decisions remain an essential element of the management of adults with AIs-ACS.

Glucocorticoid induced bone disorders in children: Research progress in treatment mechanisms

Long-term or supra-physiological dose of glucocorticoid (GC) application in clinic can lead to impaired bone growth and osteoporosis. The side effects of GC on the skeletal system are particularly serious in growing children, potentially causing growth retardation or even osteoporotic fractures. Children's bone growth is dependent on endochondral ossification of growth plate chondrocytes, and excessive GC can hinder the development of growth plate and longitudinal bone growth. Despite the availability of drugs for treating osteoporosis, they have failed to effectively prevent or treat longitudinal bone growth and development disorders caused by GCs. As of now, there is no specific drug to mitigate these severe side effects. Traditional Chinese Medicine shows potential as an alternative to the current treatments by eliminating the side effects of GC. In summary, this article comprehensively reviews the research frontiers concerning growth and development disorders resulting from supra-physiological levels of GC and discusses the future research and treatment directions for optimizing steroid therapy. This article may also provide theoretical and experimental insight into the research and development of novel drugs to prevent GC-related side effects.