Overview of treatment approaches to osteoporosis

Effect of hyperoside on osteoporosis in ovariectomized mice through estrogen receptor α/ITGβ3 signaling pathway

Osteoporosis is a highly prevalent bone metabolic disease in menopause due to estrogen deficiency. Hyperoside is a main compound in Semen cuscutae. Our team previously reported that Semen cuscutae has anti osteoporosis effect on ovariectomized mice by inhibiting bone resorption of osteoclasts. However, it is still unclear whether hyperoside affects osteoclast differentiation and bone resorption, and whether its anti-osteoporosis effect is related to an estrogen-like effect. This study investigates the potential mechanism of hyperoside's anti-osteoporotic effect by examining its impact on osteoclast differentiation and its relationship with the estrogen receptor. DXA, Micro-CT, TRAP staining, HE, and ELISA were used to assess the impact of hyperoside on OVX-induced osteoporosis. The effect of hyperoside on octeoclast differentiation was evaluated using TRAP activity assay, TRAP staining, F-actin staining. The activation of the estrogen receptor by hyperoside and its relationship with osteoclast differentiation were detected using dual-luciferase reporter assay and estrogen receptor antagonists. Our findings revealed that hyperoside (20-80 mg/kg) protect against OVX-induced osteoporosis, including increasing BMD and BMC and improving bone microstructure. Hyperoside inhibited osteoclast differentiation in a concentration dependent manner, whereas estrogen receptor α antagonists reversed its inhibitory effect osteoclast differentiation. Western blot results suggested that hyperoside inhibited TRAP, RANKL, c-Fos and ITG β3 protein expression in osteoclast or femoral bone marrow of ovariectomized mice. Our findings suggest that hyperoside inhibits osteoclast differentiation and protects OVX-induced osteoporosis through the ERα/ITGβ3 signaling pathway.

Developing and Investigating a Nanovibration Intervention for the Prevention/Reversal of Bone Loss Following Spinal Cord Injury

Osteoporosis disrupts the fine-tuned balance between bone formation and resorption, leading to reductions in bone quantity and quality and ultimately increasing fracture risk. Prevention and treatment of osteoporotic fractures is essential for reductions in mortality, morbidity, and the economic burden, particularly considering the aging global population. Extreme bone loss that mimics time-accelerated osteoporosis develops in the paralyzed limbs following complete spinal cord injury (SCI). In vitro nanoscale vibration (1 kHz, 30 or 90 nm amplitude) has been shown to drive differentiation of mesenchymal stem cells toward osteoblast-like phenotypes, enhancing osteogenesis and inhibiting osteoclastogenesis simultaneously. Here, we develop and characterize a wearable device designed to deliver and monitor continuous nanoamplitude vibration to the hindlimb long bones of rats with complete SCI. We investigate whether a clinically feasible dose of nanovibration (two 2 h/day, 5 days/week for 6 weeks) is effective at reversing the established SCI-induced osteoporosis. Laser interferometry and finite element analysis confirmed transmission of nanovibration into the bone, and microcomputed tomography and serum bone formation and resorption markers assessed effectiveness. The intervention did not reverse SCI-induced osteoporosis. However, serum analysis indicated an elevated concentration of the bone formation marker procollagen type 1 N-terminal propeptide (P1NP) in rats receiving 40 nm amplitude nanovibration, suggesting increased synthesis of type 1 collagen, the major organic component of bone. Therefore, enhanced doses of nanovibrational stimulus may yet prove beneficial in attenuating/reversing osteoporosis, particularly in less severe forms of osteoporosis.

3D-printed bone regeneration scaffolds modulate bone metabolic homeostasis through vascularization for osteoporotic bone defects

The treatment of osteoporotic bone defects poses a challenge due to the degradation of the skeletal vascular system and the disruption of local bone metabolism within the osteoporotic microenvironment. However, it is feasible to modulate the disrupted local bone metabolism imbalance through enhanced vascularization, a theory termed "vascularization-bone metabolic balance". This study developed a 3D-printed polycaprolactone (PCL) scaffold modified with EPLQLKM and SVVYGLR peptides (PCL-SE). The EPLQLKM peptide attracts bone marrow-derived mesenchymal stem cells (BMSCs), while the SVVYGLR peptide enhances endothelial progenitor cells (EPCs) vascular differentiation, thus regulating bone metabolism and fostering bone regeneration through the paracrine effects of EPCs. Further mechanistic research demonstrated that PCL-SE promoted the vascularization of EPCs, activating the Notch signaling pathway in BMSCs, leading to the upregulation of osteogenesis-related genes and the downregulation of osteoclast-related genes, thereby restoring bone metabolic balance. Furthermore, PCL-SE facilitated the differentiation of EPCs into "H"-type vessels and the recruitment of BMSCs to synergistically enhance osteogenesis, resulting in the regeneration of normal microvessels and bone tissues in cases of femoral condylar bone defects in osteoporotic SD rats. This study suggests that PCL-SE supports in-situ vascularization, remodels bone metabolic translational balance, and offers a promising therapeutic regimen for osteoporotic bone defects.

Pectolinarigenin ameliorates osteoporosis via enhancing Wnt signaling cascade in PPARβ-dependent manner

BACKGROUND

Osteoporosis is a prevalent metabolic bone disease in older adults. Peroxisome proliferator-activated receptor β (PPARβ), the most abundant PPAR isotype expressed in bone tissues, plays a critical role in regulating the energy metabolism of osteoblasts. However, the botanical compounds targeting PPARβ for the treatment of osteoporosis remain largely unexplored.

PURPOSE

To discover a potent PPARβ agonist from botanical compounds, as well as to investigate the anti-osteoporosis effects and to elucidate the underlying mechanisms of the newly identified PPARβ agonist.

METHODS

The PPARβ agonist effects of botanical compounds were screened by an in vitro luciferase reporter gene assay. The PPARβ agonist effects of pectolinarigenin (PEC) in bone marrow mesenchymal stromal cells (BMSCs) were validated by Western blotting. RNA-seq transcriptome analyses were conducted to reveal the underlying osteoporosis mechanisms of PEC in BMSCs. The PPARβ antagonist (GSK0660) and Wnt signaling inhibitor (XAV969) were used to explore the role of the PPARβ and Wnt signaling cascade in the anti-osteoporosis effects of PEC. PEC or the PEG-PLGA nanoparticles of PEC (PEC-NP) were intraperitoneally administrated in both wild-type mice and ovariectomy-induced osteoporosis mice to examine its anti-osteoporotic effects in vivo.

RESULTS

PEC, a newly identified naturally occurring PPARβ agonist, significantly promotes osteogenic differentiation and up-regulates the osteogenic differentiation-related genes (Runx2, Osterix, and Bmp2) in BMSCs. RNA sequencing and functional gene enrichment analysis suggested that PEC could activate osteogenic-related signaling pathways, including Wnt and PPAR signaling pathways. Further investigations suggested that PEC could enhance Wnt/β-catenin signaling in a PPARβ-dependent manner in BMSCs. Animal tests showed that PEC-NP promoted bone mass and density, increased the bone cell matrix protein, and accelerated bone formation in wild-type mice, while PEC-NP also played a preventive role in ovariectomy-induced osteoporosis mice via maintaining the expression level of bone cell matrix protein, balancing the rate of bone formation, and slowing down bone loss. Additionally, PEC-NP did not cause any organ injury and body weight loss after long-term use (11 weeks).

CONCLUSION

PEC significantly promotes bone formation and reduces bone loss in both BMSCs and ovariectomy-induced osteoporosis mice via enhancing the Wnt signaling cascade in a PPARβ-dependent manner, providing a new alternative therapy for preventing estrogen deficiency-induced osteoporotic diseases.

Anti-osteoporotic effects of Boswellia serrata gum resin extract in vitro and in vivo

BACKGROUND/OBJECTIVES

This study evaluated the beneficial effects of an ethanol extract of Boswellia serrata gum resin (FJH-UBS) in osteoporosis.

MATERIALS/METHODS

MC3T3-E1 osteoblastic cells and RAW 264.7 osteoclastic cells were treated with FJH-UBS. The alkaline phosphatase (ALP) activity, mineralization, collagen synthesis, osteocalcin content, and Runt-related transcription factor 2 (RUNX2) and Osterix expression were measured in MC3T3-E1 cells. The actin ring structures, tartrate-resistant acid phosphatase (TRAP) activity, and the nuclear factor of activator T-cells, cytoplasm 1 (NFATc1) expression were evaluated in RAW 264.7 cells. Ovariectomized ICR mice were orally administered FJH-UBS for eight weeks. The bone mineral density (BMD) and the serum levels of osteocalcin, procollagen 1 N-terminal propeptide (P1NP), osteoprotegerin, and TRAP 5b were analyzed.

RESULTS

FJH-UBS increased the ALP activity, collagen, osteocalcin, mineralization, and RUNX2 and osterix expression in MC3T3-E1 osteoblastic cells, whereas it decreased the TRAP activity, actin ring structures, and NFATc1 expression in RAW 264.7 osteoclastic cells. In ovariectomy-induced osteoporosis mice, FJH-UBS positively restored all of the changes in the bone metabolism biomarkers (BMD, osteocalcin, P1NP, osteoprotegerin, and TRAP 5b) caused by the ovariectomy.

CONCLUSION

FJH-UBS has anti-osteoporotic activity by promoting osteoblast activity and inhibiting osteoclast activity in vitro and in vivo, suggesting that FJH-UBS is a potential functional food ingredient for osteoporosis.

Quercetin in Osteoporosis Treatment: A Comprehensive Review of Its Mechanisms and Therapeutic Potential

PURPOSE OF REVIEW

This review aims to provide a theoretical basis and insights for quercetin's clinical application in the prevention and treatment of osteoporosis (OP), analyzing its roles in bone formation promotion, bone resorption inhibition, anti-inflammation, antioxidant effects, and potential mechanisms.

RECENT FINDINGS

OP, a prevalent bone disorder, is marked by reduced bone mineral density and impaired bone architecture, elevating the risk of fractures in patients. The primary approach to OP management is pharmacotherapy, with quercetin, a phytochemical compound, emerging as a focus of recent interest. This natural flavonoid exerts regulatory effects on bone marrow mesenchymal stem cells, osteoblasts, and osteoclasts and promotes bone health and metabolic equilibrium via anti-inflammatory and antioxidative pathways. Although quercetin has demonstrated significant potential in regulating bone metabolism, there is a need for further high-quality clinical studies focused on medicinal quercetin.

Systematical mutational analysis of teriparatide on anti-osteoporosis activity by alanine scanning

Osteoporosis is a progressive systemic skeletal disease that decreases bone density and bone quality, making them fragile and easy to break. In spite of effective anti-osteoporosis potency, teriparatide, the first anabolic medications approved for the treatment of osteoporosis, was proven to exhibit various side effects. And the relevant structure-activity relationship (SAR) of teriparatide was in need. In this work, we performed a systematical alanine scanning against teriparatide and synthesized 34 teriparatide derivatives. Their biological activities were evaluated and the importance of each residue for anti-osteoporosis activity was also revealed. A remarkable decrease in activity was observed for alanine replacement of the residue Gly12, His14, Ser17, Arg20 and Leu24, showcasing the important role of these residues in teriparatide on anti-osteoporosis activity. On contrary, when Gly13 and Gln30 were mutated to Ala, the peptide derivatives exhibited the significantly increased activities, demonstrating that these two residues could be readily replaced. Our research expanded the peptide library of teriparatide analogues and presented a potential opportunity for designing the more powerful anti-osteoporosis peptide agents.

Stem Cell and Regenerative Therapies for the Treatment of Osteoporotic Vertebral Compression Fractures

Osteoporotic vertebral compression fractures (OVCFs) significantly increase morbidity and mortality, presenting a formidable challenge in healthcare. Traditional interventions such as vertebroplasty and kyphoplasty, despite their widespread use, are limited in addressing the secondary effects of vertebral fractures in adjacent areas and do not facilitate bone regeneration. This review paper explores the emerging domain of regenerative therapies, spotlighting stem cell therapy's transformative potential in OVCF treatment. It thoroughly describes the therapeutic possibilities and mechanisms of action of mesenchymal stem cells against OVCFs, relying on recent clinical trials and preclinical studies for efficacy assessment. Our findings reveal that stem cell therapy, particularly in combination with scaffolding materials, holds substantial promise for bone regeneration, spinal stability improvement, and pain mitigation. This integration of stem cell-based methods with conventional treatments may herald a new era in OVCF management, potentially improving patient outcomes. This review advocates for accelerated research and collaborative efforts to translate laboratory breakthroughs into clinical practice, emphasizing the revolutionary impact of regenerative therapies on OVCF management. In summary, this paper positions stem cell therapy at the forefront of innovation for OVCF treatment, stressing the importance of ongoing research and cross-disciplinary collaboration to unlock its full clinical potential.

Integrated machine learning-based virtual screening and biological evaluation for identification of potential inhibitors against cathepsin K

Cathepsin K is a type of cysteine proteinase that is primarily expressed in osteoclasts and has a key role in the breakdown of bone matrix protein during bone resorption. Many studies suggest that the deficiency of cathepsin K is concomitant with a suppression of osteoclast functioning, therefore rendering the resorptive properties of cathepsin K the most prominent target for osteoporosis. This innovative work has identified a novel anti-osteoporotic agent against Cathepsin K by using a comparison of machine learning and deep learning-based virtual screening followed by their biological evaluation. Out of ten shortlisted compounds, five of the compounds (JFD02945, JFD02944, RJC01981, KM08968 and SB01934) exhibit more than 50% inhibition of the Cathepsin K activity at 0.1 μM concentration and are considered to have a promising inhibitory effect against Cathepsin K. The comprehensive docking, MD simulation, and MM/PBSA investigations affirm the stable and effective interaction of these compounds with Cathepsin K to inhibit its function. Furthermore, the compounds RJC01981, KM08968 and SB01934 are represented to have promising anti-osteoporotic properties for the management of osteoporosis owing to their significantly well predicted ADMET properties.

Discovery of a Potent Antiosteoporotic Drug Molecular Scaffold Derived from Angelica sinensis and Its Bioinspired Total Synthesis

Angelica sinensis, commonly known as Dong Quai in Europe and America and as Dang-gui in China, is a medicinal plant widely utilized for the prevention and treatment of osteoporosis. In this study, we report the discovery of a new category of phthalide from Angelica sinensis, namely falcarinphthalides A and B (1 and 2), which contains two fragments, (3R,8S)-falcarindiol (3) and (Z)-ligustilide (4). Falcarinphthalides A and B (1 and 2) represent two unprecedented carbon skeletons of phthalide in natural products, and their antiosteoporotic activities were evaluated. The structures of 1 and 2, including their absolute configurations, were established using extensive analysis of NMR spectra, chemical derivatization, and ECD/VCD calculations. Based on LC-HR-ESI-MS analysis and DFT calculations, a production mechanism for 1 and 2 involving enzyme-catalyzed Diels-Alder/retro-Diels-Alder reactions was proposed. Falcarinphthalide A (1), the most promising lead compound, exhibits potent in vitro antiosteoporotic activity by inhibiting NF-κB and c-Fos signaling-mediated osteoclastogenesis. Moreover, the bioinspired gram-scale total synthesis of 1, guided by intensive DFT study, has paved the way for further biological investigation. The discovery and gram-scale total synthesis of falcarinphthalide A (1) provide a compelling lead compound and a novel molecular scaffold for treating osteoporosis and other metabolic bone diseases.

Magnitude of Bone Disease in Transfusion-Dependent and Non-Transfusion-Dependent β-Thalassemia Patients

Introduction β-Thalassemia is a common inherited disease in the northern part of Iraq. A considerable number of transfusion-dependent (TDT) and non-transfusion-dependent (NTDT) β-thalassemia patients suffer bone problems. The objective of this study was to evaluate the degree of bone disease in the TDT and NTDT patients using a dual-energy X-ray absorptiometry (DEXA) scan. Patients and methods In this study, 53 TDT and 20 NTDT patients aged ≥10 years were enrolled. Their bone status was assessed using the DEXA scan at the lumbar spine (L1-L4) and femoral neck. The effect of physical, biochemical, and hormonal characteristics on the bone mineral density (BMD) parameters was evaluated. The value of the BMD Z-score was the measure to decide on the magnitude of bone disease. Results and discussion The mean age of the enrolled patients was 24.1 years. The BMD Z-score values were significantly lower among the TDT patients at the lumbar spine and femoral neck (BMD Z-score: -2.05 and -1.51 versus -2.29 and -0.71; p=0.044 and 0.009, respectively). The proportion of osteoporosis at the lumbar spine was significantly higher in the TDT group than in the NTDT group (69.8% versus 40%; p <0.001). The BMD Z-score correlated significantly with patient BMI and parathyroid hormone (PTH) level in both the TDT and NTDT groups. No correlation was found with age, hemoglobin (Hb), and serum levels of calcium, vitamin D, ferritin, phosphorus, and alkaline phosphatase (ALP). Conclusions Impaired bone density was encountered at high proportions in our thalassemia patients. TDT patients suffered more severe bone disease than NTDT patients.

Piperlongumine, a Piper longum-derived amide alkaloid, protects mice from ovariectomy-induced osteoporosis by inhibiting osteoclastogenesis via suppression of p38 and JNK signaling

Postmenopausal osteoporosis (PMOP) is a metabolic bone disease that results from overproduction and hyperactivation of osteoclasts caused by insufficient estrogen in women after menopause. Current therapeutic strategies are mainly focused on treating PMOP patients who have already developed severe bone loss or even osteoporotic fractures. Obviously, a better strategy is to prevent PMOP from occurring in the first place. However, such reagents are largely lacking. Piperlongumine (PLM), an amide alkaloid extracted from long pepper Piper longum, exhibits the anti-osteoclastogenic effect in normal bone marrow macrophages (BMMs) and the protective effect against osteolysis induced by titanium particles in mice. This study examined the preventive effect of PLM on PMOP and explored the potential mechanism of this effect using both ovariectomized mice and their primary cells. The result showed that PLM (5 and 10 mg kg-1) administered daily for 6 weeks ameliorated ovariectomy-induced bone loss and osteoclast formation in mice. Further cell experiments showed that PLM directly suppressed osteoclast formation, F-actin ring formation, and osteoclastic resorption pit formation in BMMs derived from osteoporotic mice, but did not obviously affect osteogenic differentiation of bone marrow stromal cells (BMSCs) from these mice. Western blot analysis revealed that PLM attenuated maximal activation of p38 and JNK pathways by RANKL stimulation without affecting acute activation of NF-κB, AKT, and ERK signaling. Furthermore, PLM inhibited expression of key osteoclastogenic transcription factors NFATc1/c-Fos and their target genes (Dcstamp, Atp6v0d2, Acp5, and Oscar). Taken together, our findings suggest that PLM inhibits osteoclast formation and function by suppressing RANKL-induced activation of the p38/JNK-cFos/NFATc1 signaling cascade, thereby preventing ovariectomy-induced osteoporosis in mice. Thus, PLM can potentially be used as an anti-resorption drug or dietary supplement for the prevention of PMOP.

A personalized biomimetic dual-drug delivery system via controlled release of PTH1-34 and simvastatin for in situ osteoporotic bone regeneration

Patients with osteoporosis often encounter clinical challenges of poor healing after bone transplantation due to their diminished bone formation capacity. The use of bone substitutes containing bioactive factors that increase the number and differentiation of osteoblasts is a strategy to improve poor bone healing. In this study, we developed an in situ dual-drug delivery system containing the bone growth factors PTH1-34 and simvastatin to increase the number and differentiation of osteoblasts for osteoporotic bone regeneration. Our system exhibited ideal physical properties similar to those of natural bone and allowed for customizations in shape through a 3D-printed scaffold and GelMA. The composite system regulated the sustained release of PTH1-34 and simvastatin, and exhibited good biocompatibility. Cell studies revealed that the composite system reduced osteoblast death, and promoted expression of osteoblast differentiation markers. Additionally, by radiographic analysis and histological observation, the dual-drug composite system demonstrated promising bone regeneration outcomes in an osteoporotic skull defect model. In summary, this composite delivery system, comprising dual-drug administration, holds considerable potential for bone repair and may serve as a safe and efficacious therapeutic approach for addressing bone defects in patients with osteoporosis.

Study on the mechanism of naringin in promoting bone differentiation: In vitro and in vivo study

Objective

Osteoporosis is a common clinical bone disease that occurs most frequently in middle-aged and elderly people. Various traditional herbal medicine formulations have shown significant benefits in models of osteoporosis. In this study, we aim to investigate the osteogenic efficacy of naringin (NRG) in the osteoporotic state.

Design

We treated Bone marrow stromal cells (BMSCs) with various concentrations of NRG for 3 and 7 days. BMSC proliferation was measured by the MTT assay. The effect of NRG on the osteogenic differentiation of BMSCs was detected by ALP and alizarin red staining. The effect of NRG on the BMP2/Runx2/Osterix signaling pathway was analyzed by using real-time PCR. The effect of NRG on the oestrogen receptor was measured by Enzyme-linked immunosorbent assay. In vivo animal experiments were performed by micro-computed tomography and ALP immunohistochemistry to determine the ectopic osteogenic effect of NRG sustained-release nanoparticles in a mouse model of osteoporosis.

Results

NRG promoted the proliferation and osteogenic differentiation of BMSCs. Moreover, it also activated the BMP2/Runx2/Osterix signaling pathway. When NRG sustained-release nanoparticles were added in vivo in animal experiments, we found that NRG sustained-release nanoparticles had better ectopic osteogenic effects in a mouse model of osteoporosis.

Conclusions

NRG induced osteoblastic differentiation of BMSCs by activating the BMP2/Runx2/Osterix signaling pathway and promoted the regulation of oestrogen receptor pathway protein expression, and NRG sustained-release nanoparticles exerted a more significant in vivo ectopic osteogenic effect in an osteoporosis mouse model. Therefore, naringin is expected to be developed as a novel treatment for inducing osteogenesis, because of its ubiquitous, cost-efficient, and biologically active characteristics. However, further research is needed on how to improve the pharmacokinetic properties of naringin and its specific mechanism.

Design, Synthesis, and Anti-Osteoporotic Characterization of Arginine N-Glycosylated Teriparatide Analogs via the Silver-catalyzed Solid-Phase Glycosylation Strategy

In spite of effective antiosteoporosis potency, teriparatide, a bone-building agent approved by the FDA (Food and Drug Administration), was proven to exhibit various side effects. In our previous work, we developed a universal strategy for synthesizing arginine N-glycosylated peptides termed silver-promoted solid-phase glycosylation (SSG) strategy. However, it is unknown whether the SSG strategy can be applied in the peptide drug design. Herein, we first reported the optimization of teriparatide via SSG strategy. Using Arg20 and/or Arg25 as the modifying positions, three series of arginine N-glycosylated teriparatide analogs were successfully synthesized, of which the introduced sugar groups included glucose, galactose, mannose, rhamnose, ribose, 2-acetamino-2-deoxy-glucose, xylose, lactose, and maltose. Among the 27 arginine N-glycosylated derivatives, Arg20-xylose and Arg25-maltose teriparatide analogs, termed PTH-1g and PTH-2i, respectively, indicated enhanced serum stability and significantly improved antiosteoporotic activities in vitro and in vivo compared with the native counterpart. They may serve as effective therapeutic candidates for treating osteoporosis.

Plant-derived natural medicines for the management of osteoporosis: A comprehensive review of clinical trials

Background

Osteoporosis is a chronic and systemic skeletal disease that is defined by low bone mineral density (BMD) along with an increase in bone fragility and susceptibility to fracture. This study aimed to overview clinical evidence on the use of herbal medicine for management of osteoporosis.

Methods

Electronic databases including Pubmed, Medline, Cochrane library, and Scopus were searched until November 2022 for any clinical studies on the efficacy and/or safety of plant-derived medicines in the management of osteoporosis.

Results

The search yielded 57 results: 19 on single herbs, 16 on multi-component herbal preparations, and 22 on plant-derived secondary metabolites. Risk of fracture, bone alkaline phosphatase, BMD, and specific bone biomarkers are investigated outcomes in these studies. Medicinal plants including Acanthopanax senticosus, Actaea racemosa, Allium cepa, Asparagus racemosus, Camellia sinensis, Cissus quadrangularis, Cornus mas, Nigella sativa, Olea europaea, Opuntia ficus-indica, Pinus pinaster, Trifolium pretense and phytochemicals including isoflavones, ginsenoside, Epimedium prenyl flavonoids, tocotrienols are among plant-derived medicines clinically investigated on osteoporosis. It seems that multi-component herbal preparations were more effective than single-component ones; because of the synergistic effects of their constituents. The investigated herbal medicines demonstrated their promising results in osteoporosis via targeting different pathways in bone metabolism, including balancing osteoblasts and osteoclasts, anti-inflammatory, immunomodulatory, antioxidant, and estrogen-like functions.

Conclusion

It seems that plant-derived medicines have beneficial effects on bone and may manage osteoporosis by affecting different targets and pathways involved in osteoporosis; However, Future studies are needed to confirm the effectiveness and safety of these preparations.

Osteoporosis treatment and pain relief: A scoping review

BACKGROUND AND OBJECTIVE

Anti-osteoporosis (OP) drugs have been suggested to contribute to pain reduction during OP management. This scoping review aimed at mapping the literature on pain relief with anti-OP drugs in OP treatment.

DATABASES AND DATA TREATMENT

Medline, Pubmed and Cochrane databases were searched by two reviewers with keywords combinations. Randomized controlled and real-life English studies, pain as an endpoint, antiosteoporosis drugs were inclusion criteria. Case reports, surveys, comment letters, conference abstracts, animal studies and grey literature were excluded. Predetermined data were extracted by two reviewers and disagreement solved through discussion.

RESULTS

A total of 130 articles were identified, 31 publications were included, 12 randomized clinical trials and 19 observational studies. Pain reduction was assessed by different tools: Visual Analogue Scale, Verbal Rating Scale, Facial Scale or as a domain of quality of life questionnaires including Short form 8, 36, mini-OP, Japanese OP, Qualeffo, Roland Morris Disability questionnaires. Collective data show that anti-OP drugs may display an analgesic effect that may be linked to the local mode of action of drugs on bone and consecutive modulation of pain sensitization. The methodology of the studies showed a heterogeneity of endpoints, comparators, statistical approaches and follow-up duration.

CONCLUSION

Considering the limitations of the literature, there is a need for more rigorous trials and larger real-life studies taking into account the recommendations published for research in rheumatology and in pain medicine. The identification of responders, patient subtypes, and of analgesic-effect doses would allow optimization and individualization for pain relief in patients with OP.

SIGNIFICANCE STATEMENT

This scoping review shows that anti-OP drugs may improve pain and quality of life of patients with OP. The heterogeneity in design, choice of endpoints, methodology, comparators and follow-up duration of included randomized clinical trials and real-life studies does not allow so far to identify a predominant antiosteoporosis drug or an optimal dosage for pain relief. These gaps need to be addressed and warrant further research in the future for optimizing pain improvement in the course of OP drug treatment.

Metabolic bone disorders and the promise of marine osteoactive compounds

Metabolic bone disorders and associated fragility fractures are major causes of disability and mortality worldwide and place an important financial burden on the global health systems. These disorders result from an unbalance between bone anabolic and resorptive processes and are characterized by different pathophysiological mechanisms. Drugs are available to treat bone metabolic pathologies, but they are either poorly effective or associated with undesired side effects that limit their use. The molecular mechanism underlying the most common metabolic bone disorders, and the availability, efficacy, and limitations of therapeutic options currently available are discussed here. A source for the unmet need of novel drugs to treat metabolic bone disorders is marine organisms, which produce natural osteoactive compounds of high pharmaceutical potential. In this review, we have inventoried the marine osteoactive compounds (MOCs) currently identified and spotted the groups of marine organisms with potential for MOC production. Finally, we briefly examine the availability of in vivo screening and validation tools for the study of MOCs.

Gallium-doped thermochemically treated titanium reduces osteoclastogenesis and improves osteodifferentiation

Excessive bone resorption is one of the main causes of bone homeostasis alterations, resulting in an imbalance in the natural remodeling cycle. This imbalance can cause diseases such as osteoporosis, or it can be exacerbated in bone cancer processes. In such cases, there is an increased risk of fractures requiring a prosthesis. In the present study, a titanium implant subjected to gallium (Ga)-doped thermochemical treatment was evaluated as a strategy to reduce bone resorption and improve osteodifferentiation. The suitability of the material to reduce bone resorption was proven by inducing macrophages (RAW 264.7) to differentiate to osteoclasts on Ga-containing surfaces. In addition, the behavior of human mesenchymal stem cells (hMSCs) was studied in terms of cell adhesion, morphology, proliferation, and differentiation. The results proved that the Ga-containing calcium titanate layer is capable of inhibiting osteoclastogenesis, hypothetically by inducing ferroptosis. Furthermore, Ga-containing surfaces promote the differentiation of hMSCs into osteoblasts. Therefore, Ga-containing calcium titanate may be a promising strategy for patients with fractures resulting from an excessive bone resorption disease.

Expanding the therapeutic potential of Salvia miltiorrhiza: a review of its pharmacological applications in musculoskeletal diseases

Salvia miltiorrhiz, commonly known as "Danshen" in Chinese medicine, has longstanding history of application in cardiovascular and cerebrovascular diseases. Renowned for its diverse therapeutic properties, including promoting blood circulation, removing blood stasis, calming the mind, tonifying the blood, and benefiting the "Qi", recent studies have revealed its significant positive effects on bone metabolism. This potential has garnered attention for its promising role in treating musculoskeletal disorders. Consequently, there is a high anticipation for a comprehensive review of the potential of Salvia miltiorrhiza in the treatment of various musculoskeletal diseases, effectively introducing an established traditional Chinese medicine into a burgeoning field.

AIM OF THE REVIEW

Musculoskeletal diseases (MSDs) present significant challenges to healthcare systems worldwide. Previous studies have demonstrated the high efficacy and prospects of Salvia miltiorrhiza and its active ingredients for treatment of MSDs. This review aims to illuminate the newfound applications of Salvia miltiorrhiza and its active ingredients in the treatment of various MSDs, effectively bridging the gap between an established medicine and an emerging field.

METHODS

In this review, previous studies related to Salvia miltiorrhiza and its active ingredients on the treatment of MSD were collected, the specific active ingredients of Salvia miltiorrhiza were summarized, the effects of Salvia miltiorrhiza and its active ingredients for the treatment of MSDs, as well as their potential molecular mechanisms were reviewed and discussed.

RESULTS

Based on previous publications, Salvianolic acid A, salvianolic acid B, tanshinone IIA are the representative active ingredients of Salvia miltiorrhiza. Their application has shown significant beneficial outcomes in osteoporosis, fractures, and arthritis. Salvia miltiorrhiza and its active ingredients protect against MSDs by regulating different signaling pathways, including ROS, Wnt, MAPK, and NF-κB signaling.

CONCLUSION

Salvia miltiorrhiza and its active ingredients demonstrate promising potential for bone diseases and have been explored across a wide variety of MSDs. Further exploration of Salvia miltiorrhiza's pharmacological applications in MSDs holds great promise for advancing therapeutic interventions and improving the lives of patients suffering from these diseases.

Trim21 depletion alleviates bone loss in osteoporosis via activation of YAP1/β-catenin signaling

Despite the diverse roles of tripartite motif (Trim)-containing proteins in the regulation of autophagy, the innate immune response, and cell differentiation, their roles in skeletal diseases are largely unknown. We recently demonstrated that Trim21 plays a crucial role in regulating osteoblast (OB) differentiation in osteosarcoma. However, how Trim21 contributes to skeletal degenerative disorders, including osteoporosis, remains unknown. First, human and mouse bone specimens were evaluated, and the results showed that Trim21 expression was significantly elevated in bone tissues obtained from osteoporosis patients. Next, we found that global knockout of the Trim21 gene (KO, Trim21-/-) resulted in higher bone mass compared to that of the control littermates. We further demonstrated that loss of Trim21 promoted bone formation by enhancing the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and elevating the activity of OBs; moreover, Trim21 depletion suppressed osteoclast (OC) formation of RAW264.7 cells. In addition, the differentiation of OCs from bone marrow-derived macrophages (BMMs) isolated from Trim21-/- and Ctsk-cre; Trim21f/f mice was largely compromised compared to that of the littermate control mice. Mechanistically, YAP1/β-catenin signaling was identified and demonstrated to be required for the Trim21-mediated osteogenic differentiation of BMSCs. More importantly, the loss of Trim21 prevented ovariectomy (OVX)- and lipopolysaccharide (LPS)-induced bone loss in vivo by orchestrating the coupling of OBs and OCs through YAP1 signaling. Our current study demonstrated that Trim21 is crucial for regulating OB-mediated bone formation and OC-mediated bone resorption, thereby providing a basis for exploring Trim21 as a novel dual-targeting approach for treating osteoporosis and pathological bone loss.

Micheliolide prevents estrogen deficiency-induced bone loss via inhibiting osteoclast bone resorption

Osteoporosis is one of the major health problems characterized by decreased bone density and increased risk of fractures. Nowadays, the treating strategies against osteoporosis are efficient, but still have some drawbacks. Micheliolide, a guaianolide sesquiterpene lactone isolated from Michelia compressa and Michelia champac, has been reported to have anti-inflammatory effects. Here, our data suggest that Micheliolide could protect mice from ovariectomy induced bone loss. According to the Micro-CT scan and histomorphometry quantification data, Micheliolide treatment inhibits excessive osteoclast bone resorption without affecting bone formation in estrogen deficiency mice. Consistently, our data suggest that Micheliolide could inhibit osteoclastogenesis in vitro. Additionally, we confirmed that Micheliolide inhibits osteoclasts formation via inhibiting P38 MAPK signaling pathway, and P79350 (a P38 agonist) could rescue this effect. In summary, our data suggest that Micheliolide could ameliorate estrogen deficiency-induced bone loss via attenuating osteoclastogenesis. Hence, Micheliolide could be used as a novel anti-resorptive agent against osteoporosis.

Bone-Targeted Delivery of Cell-Penetrating-RUNX2 Fusion Protein in Osteoporosis Model

The onset of osteoporosis leads to a gradual decrease in bone density due to an imbalance between bone formation and resorption. To achieve optimal drug efficacy with minimal side effects, targeted drug delivery to the bone is necessary. Previous studies have utilized peptides that bind to hydroxyapatite, a mineral component of bone, for bone-targeted drug delivery. In this study, a hydroxyapatite binding (HAB) tag is fused to 30Kc19α-Runt-related transcription factor 2 (RUNX2) for bone-targeting. This recombinant protein can penetrate the nucleus of human mesenchymal stem cells (hMSCs) and act as a master transcription factor for osteogenesis. The HAB tag increases the binding affinity of 30Kc19α-RUNX2 to mineral deposition in mature osteoblasts and bone tissue, without affecting its osteogenic induction capability. In the osteoporosis mouse model, intravenous injection of HAB-30Kc19α-RUNX2 results in preferential accumulation in the femur and promotes bone formation while reducing toxicity in the spleen. These findings suggest that HAB-30Kc19α-RUNX2 may be a promising candidate for bone-targeted therapy in osteoporosis.

Apolipoprotein E deficiency attenuated osteogenesis via down-regulating osterix

Apolipoprotein E (ApoE), a ligand for low-density lipoprotein receptors, is strongly induced during osteogenesis and has a physiologic role in regulating osteoblast function, but the mechanisms of its action are still unclear. The study aims to elucidate the influence and molecular mechanisms of ApoE on bone formation. An ovariectomy-induced osteoporotic model were conducted in ApoE knockout (ApoE-/-) mice to study the effect of ApoE on the bone system. Bone quality were assessed through bone mineral density and histomorphometric analysis. To investigate the underlying role and mechanisms of ApoE during osteogenesis, primary osteoblasts from the calvariums of newborn ApoE-/- or wild-type (WT) mice were cultured in the osteoblastic differentiation medium in vitro for further research. Our animal experiment data showed that ApoE-/- mice exhibited bone loss, exacerbated by estrogen deprivation after ovariectomy. ApoE deficiency attenuated osteoblast activity and inhibited osteoblast osteogenesis, accompanied by decreased osterix expression. ApoE deficiency did not affect primary osteoblast viability and collagen-1 expression. Moreover, osteoprotegerin expression in ApoE-/- osteoblasts was reduced compared to WT controls. Our study demonstrated that ApoE gene deficiency contributed to bone loss and attenuated osteogenesis by down-regulating osterix expression.

Impact of COVID-19 pandemic on pharmacologic treatment of patients newly diagnosed with osteoporosis

PURPOSE

This study determined whether initiation of pharmacologic treatment was delayed for newly diagnosed osteoporosis patients during the COVID-19 pandemic.

METHODS

1,189 patients ≥50 years with newly diagnosed osteoporosis using dual-energy x-ray absorptiometry (DXA) screening at a single academic institution were included. Patients with previous osteoporosis were excluded. Patients diagnosed between March 1, 2018-January 31, 2020 (pre-pandemic cohort, n = 576) were compared to those diagnosed between March 1, 2020-January 31, 2022 (pandemic cohort, n = 613). Age, sex, race, ethnicity, ordering providers (primary vs specialty), and pharmacological agents were evaluated. Primary outcomes included proportion of patients prescribed therapy within 3 and 6-months of diagnosis, and mean time from diagnosis to treatment initiation.

RESULTS

The pre-pandemic cohort had more White patients (74.3 vs 68.4%, p = .02) and no differences between remaining demographic variables. Only 40.5% of newly diagnosed patients initiated pharmacologic therapy within 6 months. Patients treated at 3-months (31.8 vs 35.4%, p = 0.19) and 6-months (37.8 vs 42.9, p = 0.08) were comparable between cohorts (47.2 vs 50.2% p = 0.30). Mean time from diagnosis to treatment initiation was similar (46 vs 45 days, p = 0.72). There were no treatment differences based on gender, race, or ethnicity or between ordering providers (65.1 vs 57.4% primary care, p = 0.08). Bisphosphonates were most often prescribed in both cohorts (89% vs 82.1%).

CONCLUSIONS

This is the first study assessing COVID-19's impact on pharmacologic treatment of newly diagnosed osteoporosis. 40.5% of newly diagnosed patients were treated pharmacologically within six months of diagnosis, and the pandemic did not significantly affect treatment rates.

Curculigo orchioides polysaccharide COP70-1 stimulates osteogenic differentiation of MC3T3-E1 cells by activating the BMP and Wnt signaling pathways

The crude polysaccharide CO70 isolated from Curculigo orchioides could alleviate ovariectomy-induced osteoporosis in rats. To clarify the bioactive components, a new heteropolysaccharide (COP70-1) was purified from CO70 in this study, which was consisted of β-D-Manp-(1→, →4)-α-D-Glcp-(1→, →4)-β-D-Manp-(1→, →3,4)-β-D-Manp-(1→, →4,6)-β-D-Manp-(1→, and →4,6)-α-D-Galp-(1→. COP70-1 significantly promoted the osteoblastic differentiation of MC3T3-E1 cells through improving alkaline phosphatase activity, the deposition of calcium as well as up-regulating the expression of osteogenic markers (RUNX2, OSX, BSP, OCN, and OPN). Furthermore, COP70-1 stimulated the expression of critical transcription factors of the BMP and Wnt pathways, including BMP2, p-SMAD1, active-β-catenin, p-GSK-3β, and LEF-1. In addition, LDN (BMP pathway inhibitor) and DKK-1 (Wnt pathway inhibitor) suppressed the COP70-1-induced osteogenic differentiation of MC3T3-E1 cells. Therefore, COP70-1 was one of the bioactive constituents of C. orchioides for targeting osteoblasts to treat osteoporosis by triggering BMP/Smad and Wnt/β-catenin pathways.

Short-term effect of apparent temperature on daily hospitalizations for osteoporotic fractures in Beijing, China: A retrospective observational study

BACKGROUND

Studies on the associations between temperature and osteoporotic fractures (OF) hospitalizations are limited. This study aimed to assess the short-term effect of apparent temperature (AT) on the risk of OF hospitalizations.

METHODS

This retrospective observational study was conducted in Beijing Jishuitan Hospital from 2004 to 2021. Daily OF hospitalizations, meteorological variables and fine particulate matter were collected. A Poisson generalized linear regression model combined with a distributed lag non-linear model was applied to analyze the lag-exposure-response relationship between AT and the number of OF hospitalizations. Subgroup analysis by gender, age and fracture type was also conducted.

RESULTS

Total daily hospitalization visits for OF during the studied period were 35,595. The exposure-response curve of AT and OF presented a non-linear relationship, with optimum apparent temperature (OAT) at 28.40 °C. Taking OAT as the reference, the cold effect (-10.58 °C, 2.5th percentage) on single lag day had statistical significance from the current day of exposure (RR = 1.18, 95 % CI: 1.08-1.28) to lag 4 day (RR = 1.04, 95 % CI: 1.01-1.08), while the cumulative cold effect increased the risk of OF hospitalization visits from lag 0 to 14 days, with the maximum RR over lag 0-14 days (RR = 1.84, 95 % CI: 1.21-2.79). There were no significant risks of OF hospitalizations for warm effects (32.53 °C, 97.5th percentage) on single or cumulative lag days. The cold effect might be more evident among females, patients aged 80 years or older, and patients with hip fractures.

CONCLUSION

Exposure to cold temperatures is associated with an increased risk of OF hospitalizations. Females, patients aged 80 years or older and patients with hip fractures might be more vulnerable to the cold effect of AT.

Bone-targeting polyphosphodiesters that promote osteoblastic differentiation

Polymers for pharmaceutical use have been attractive in medical treatments because of the conjugation of multifunctional components and their long circulation time in the blood stream. Bone-targeted drug delivery systems are also no exceptional, and several polymers have been proposed for the treatment of bone diseases, such as cancer metastasis and osteoporosis. Herein, we report that polyphosphodiesters (PPDEs) have a potential to enhance osteoblastic differentiation, and they have a targeting ability to bone tissues in vivo. Two types of PPDEs, poly (ethylene sodium phosphate) (PEP•Na) and poly (propylene sodium phosphate) (PPP•Na), have been synthesized. Regardless of the alkylene structure in the main chain of PPDEs, the gene expression of osteoblast-specific transcription factors and differentiation markers of mouse osteoblastic-like cells (MC3T3-E1 cells) cultured in a differentiation medium was significantly upregulated by the addition of PPDEs. Moreover, it was also clarified that the signaling pathway related to cytoplasmic calcium ions was activated by PPDEs. The mineralization of MC3T3-E1 cells has a similar trend with its gene expression and is synergistically enhanced by PPDEs with β-glycerophosphate. The biodistribution of fluorescence-labeled PPDEs was also determined after intravenous injection in mice. PPDEs accumulated well in the bone through the blood stream, whereas polyphosphotriesters (PPTEs) tended to be excreted from the kidneys. Hydrophilic PEP•Na showed a superior bone affinity as compared with PPP•Na. PPDEs could be candidate polymers for the restoration of bone remodeling and bone-targeting drug delivery platforms.

Structural characterization and anti-osteoporosis effects of polysaccharide purified from Eucommia ulmoides Oliver cortex based on its modulation on bone metabolism

EuOCP3, with a molecular weight of 38.1 kDa, is an acidic polysaccharide purified from Eucommia ulmoides Oliver cortex. Herein, we determined that the main backbone of EuOCP3 was predominantly composed of →4)-α-GalpA-(1 → 4)-α-GalpA-(1→, →4)-α-GalpA-(1 → 5)-α-Araf-(1→, →4)-α-GalpA-(1 → 2)-α-Rhap-(1→, and →4)-α-GalpA-(1 → 5)-α-Araf-(1 → 2)-α-Rhap-(1 → repeating blocks, which were connected by →2,3,5)-α-Araf-(1→. The side chains, substituted at C-2 and C-5 of →2,3,5)-α-Araf-(1→, contained T-β-Araf→ and T-β-Araf → 4)-α-GalpA-(1 → residues. In dexamethasone (Dex)-induced osteoporosis (OP) mice, EuOCP3 treatment restored cortical bone thickness, increased mineralized bone area, enhanced the number of osteoblasts, and decreased the number of osteoclasts on the surface of cortical bone. Combining analysis of gut microflora, serum metabolite profiles, and biological detection results, we demonstrated that EuOCP3 regulated the abundance of specific species within the gut microflora, such as g_Dorea and g_Prevotella, and ameliorated oxidative stress. In turn, enhancement of osteogenic function and restoration of bone metabolism via the extracellular signal-regulated kinase (ERK)/c-Jun N-terminal kinase (JNK)/nuclear factor erythroid-2 related factor 2 (Nrf2) signaling pathway was indicated. The current findings contribute to understanding the potential of EuOCP3 in anti-OP treatment.

Pharmaceutical treatment of bone loss: From animal models and drug development to future treatment strategies

Animal models are fundamental to advance our knowledge of the underlying pathophysiology of bone loss and to study pharmaceutical countermeasures against it. The animal model of post-menopausal osteoporosis from ovariectomy is the most widely used preclinical approach to study skeletal deterioration. However, several other animal models exist, each with unique characteristics such as bone loss from disuse, lactation, glucocorticoid excess, or exposure to hypobaric hypoxia. The present review aimed to provide a comprehensive overview of these animal models to emphasize the importance and significance of investigating bone loss and pharmaceutical countermeasures from perspectives other than post-menopausal osteoporosis only. Hence, the pathophysiology and underlying cellular mechanisms involved in the various types of bone loss are different, and this might influence which prevention and treatment strategies are the most effective. In addition, the review sought to map the current landscape of pharmaceutical countermeasures against osteoporosis with an emphasis on how drug development has changed from being driven by clinical observations and enhancement or repurposing of existing drugs to today's use of targeted anti-bodies that are the result of advanced insights into the underlying molecular mechanisms of bone formation and resorption. Moreover, new treatment combinations or repurposing opportunities of already approved drugs with a focus on dabigatran, parathyroid hormone and abaloparatide, growth hormone, inhibitors of the activin signaling pathway, acetazolamide, zoledronate, and romosozumab are discussed. Despite the considerable progress in drug development, there is still a clear need to improve treatment strategies and develop new pharmaceuticals against various types of osteoporosis. The review also highlights that new treatment indications should be explored using multiple animal models of bone loss in order to ensure a broad representation of different types of skeletal deterioration instead of mainly focusing on primary osteoporosis from post-menopausal estrogen deficiency.

Network pharmacology-based mechanism prediction and pharmacological validation of Bushenhuoxue formula attenuating postmenopausal osteoporosis in ovariectomized mice

BACKGROUND

Bushenhuoxue (BSHX) formula, a ten-compound herbal decoction, is widely used to treat postmenopausal osteoporosis (PMOP) in China. However, the mechanism is not clear yet.

METHODS

The underlying biological processes and signaling pathways were predicted by network pharmacology. In vivo experimental study, 24 female C57BL/6 J mice were randomly divided into sham, ovariectomized (OVX) and BSHX formula groups. Mice in the latter two groups were subjected to bilateral ovariectomy, and mice in the BSHX formula group were extra treated by BSHX formula at an oral dosage of 0.2 mL/10 g for 8 weeks. The femur samples were harvested for tissue analyses including μCT assay, histology and immunohistochemical (IHC) staining of VEGF signaling.

RESULTS

A total of 218 active ingredients and 274 related targets were identified in BSHX formula. After matching with 292 targets of PMOP, 64 overlapping genes were obtained. GO and KEGG enrichment analyses on these 64 genes revealed that angiogenesis and VEGF signaling were considered as the potential therapeutic mechanism of BSHX formula against PMOP. Animal experiments showed that mice in the BSHX formula-treated group presented increased bone mass, microstructural parameters, blood vessel numbers and an activation of VEGF signaling (VEGF, COX2, eNOS and CD31) compared to the OVX mice.

CONCLUSION

This study revealed that BSHX formula exerts anti-PMOP effects possibly through activating VEGF signaling-mediated angiogenesis.

Biomineralized Piezoelectrically Active Scaffolds for Inducing Osteogenic Differentiation

There is an endogenous electric field in living organisms, which plays a vital role in the development and regeneration of bone tissue. Therefore, self-powered piezoelectric material for bone repair has become hot research in recent years. However, the current piezoelectric materials for tissue regeneration still have the shortcomings of lack of biological activity and three-dimensional structure. Here, we proposed a three-dimensional polyurethane foam (PUF) scaffold coated with piezoelectric poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and modified by a calcium phosphate (CaP) mineralized coating. The preferred scaffold has an open circuit voltage and short circuit current output of 5 V and 200 nA. Combining the physical and chemical properties of the CaP coating, the piezoelectric signal of PVDF-HFP and the three-dimensional structure of PUF, the scaffold exhibits superior promotion of cell osteogenic differentiation and ectopic bone formation in vivo. The mechanism is attributed to an increase in intracellular Ca²⁺ levels in response to chemical and piezoelectric stimulation with the material. This research not only paves the way for the application of piezoelectric scaffolds to stimulate osteoblasts differentiation in situ, but also lays the foundation for the clinical treatment of long-term osteoporosis.

A variability in response of osteoclasts to zoledronic acid is mediated by smoking-associated modification in the DNA methylome

BACKGROUND

Clinical trials have shown zoledronic acid as a potent bisphosphonate in preventing bone loss, but with varying potency between patients. Human osteoclasts ex vivo reportedly displayed a variable sensitivity to zoledronic acid > 200-fold, determined by the half-maximal inhibitory concentration (IC50), with cigarette smoking as one of the reported contributors to this variation. To reveal the molecular basis of the smoking-mediated variation on treatment sensitivity, we performed a DNA methylome profiling on whole blood cells from 34 healthy female blood donors. Multiple regression models were fitted to associate DNA methylation with ex vivo determined IC50 values, smoking, and their interaction adjusting for age and cell compositions.

RESULTS

We identified 59 CpGs displaying genome-wide significance (p < 1e-08) with a false discovery rate (FDR) < 0.05 for the smoking-dependent association with IC50. Among them, 3 CpGs have p < 1e-08 and FDR < 2e-03. By comparing with genome-wide association studies, 15 significant CpGs were locally enriched (within < 50,000 bp) by SNPs associated with bone and body size measures. Furthermore, through a replication analysis using data from a published multi-omics association study on bone mineral density (BMD), we could validate that 29 out of the 59 CpGs were in close vicinity of genomic sites significantly associated with BMD. Gene Ontology (GO) analysis on genes linked to the 59 CpGs displaying smoking-dependent association with IC50, detected 18 significant GO terms including cation:cation antiporter activity, extracellular matrix conferring tensile strength, ligand-gated ion channel activity, etc. CONCLUSIONS: Our results suggest that smoking mediates individual sensitivity to zoledronic acid treatment through epigenetic regulation. Our novel findings could have important clinical implications since DNA methylation analysis may enable personalized zoledronic acid treatment.

Probucol suppresses osteoclastogenesis via activating Nrf2 signaling and ameliorates ovariectomy-induced bone loss

Osteoporosis is a systemic and endocrine bone disorder distinguished by declined bone mineral density, compromised bone strength, and destruction of trabecular structure. The abnormally excessive osteoclastogenesis and bone erosion play imperative roles in the progression of osteoporosis. However, treatment of osteoporosis is far from satisfactory due to poor adherence to existing medications and adverse reactions, there is an urgent to develop novel therapies for osteoporosis. Probucol, a synthetic compound with two characteristic phenolic rings, owns anti-inflammatory and antioxidant properties. Accumulating evidence have indicated that intracellular reactive oxygen species (ROS) is closely related to osteoclastogenesis. Hence, we investigated the potential effects of probucol on osteoclastogenesis in vivo and in vitro. In this study, TRAP staining and bone slice resorption assay showed that probucol suppressed RANKL-induced osteoclast formation and function. The mRNA and protein levels of osteoclastogenesis marker genes were reduced by probucol in a concentration-dependent manner. Besides, probucol suppressed osteoclast differentiation by inhibiting ROS production, MAPKs and NF-κB signaling pathways, while Nrf2 silencing reversed the inhibitory effect of probucol on osteoclast formation and function. Consistent with the above findings, in vivo experiments demonstrated that probucol visibly alleviated bone loss caused by estrogen deficiency. In brief, these results showed the potential of anti-oxidant compound probucol in the treatment of osteoporosis, highlighting Nrf2 as a promising target in osteoclast-related disease.

Effect of Bifidobacterium on osteoclasts: TNF-α/NF-κB inflammatory signal pathway-mediated mechanism

Osteoporosis is a systemic multifactorial bone disease characterized by low bone quality and density and bone microstructure damage, increasing bone fragility and fracture vulnerability. Increased osteoclast differentiation and activity are important factors contributing to bone loss, which is a common pathological manifestation of bone diseases such as osteoporosis. TNF-a/NF-κB is an inflammatory signaling pathway with a key regulatory role in regulating osteoclast formation, and the classical pathway RANKL/RANK/OPG assists osteoclast formation. Activation of this inflammatory pathway promotes the formation of osteoclasts and accelerates the process of osteoporosis. Recent studies and emerging evidence have consistently demonstrated the potential of probiotics to modulate bone health. Secretions of Bifidobacterium, a genus of probiotic bacteria in the phylum Actinobacteria, such as short-chain fatty acids, equol, and exopolysaccharides, have indicated beneficial effects on bone health. This review discusses the molecular mechanisms of the TNF-a/NF-κB inflammatory pathway in regulating osteoclast formation and describes the secretions produced by Bifidobacterium and their potential effects on bone health through this pathway, opening up new directions for future research.

Libanoridin Isolated from Corydalis heterocarpa Inhibits Adipogenic Differentiation of Bone Marrow-Derived Mesenchymal Stromal Cells

Bone marrow adiposity is a complication in osteoporotic patients. It is a result of the imbalance between adipogenic and osteogenic differentiation of bone marrow cells. Phytochemicals can alleviate osteoporotic complications by hindering bone loss and decreasing bone marrow adiposity. Corydalis heterocarpa is a biennial halophyte with reported bioactivities, and it is a source of different coumarin derivatives. Libanoridin is a coumarin isolated from C. heterocarpa, and the effect of libanoridin on adipogenic differentiation of human bone marrow-derived mesenchymal stromal cells (hBM-MSCs) was evaluated in the present study. Cells were induced to undergo adipogenesis, and their intracellular lipid accumulation and expression of adipogenic markers were observed under libanoridin treatment. Results showed that 10 μM libanoridin-treated adipocytes accumulated 44.94% less lipid compared to untreated adipocytes. In addition, mRNA levels of PPARγ, C/EBPα, and SREBP1c were dose-dependently suppressed with libanoridin treatment, whereas only protein levels of PPARγ were decreased in the presence of libanoridin. Fluorescence staining of adipocytes also revealed that cells treated with 10 μM libanoridin expressed less PPARγ compared to untreated adipocytes. Protein levels of perilipin and leptin, markers of mature adipocytes, were also suppressed in adipocytes treated with 10 μM libanoridin. Analysis of MAPK phosphorylation levels showed that treatment with libanoridin inhibited the activation of p38 and JNK MAPKs observed by decreased levels of phosphorylated p38 and JNK protein. It was suggested that libanoridin inhibited adipogenic differentiation of hBM-MSCs via suppressing MAPK-mediated PPARγ signaling. Future studies revealing the anti-adipogenic effects of libanoridin in vivo and elucidating its action mechanism will pave the way for libanoridin to be utilized as a nutraceutical with anti-osteoporotic properties.

An effect comparison of alendronate and teriparatide in patients with glucocorticoid-induced osteoporosis: A protocol for systematic review and meta-analysis

BACKGROUND

Glucocorticoid-induced osteoporosis is the most common secondary cause of osteoporosis and the resulting fractures cause significant morbidity. Oral bisphosphonates are currently regarded as first line options on the grounds of their low cost. However, teriparatide has been shown to be superior in its effects on bone mineral density and vertebral fracture risk in glucocorticoid-treated individuals with osteoporosis. We conducted a protocol for systematic review and meta-analysis to assess the effectiveness of alendronate and teriparatide in patients with glucocorticoid-induced osteoporosis.

METHODS

The study protocol has been registered on international prospective register of systematic review (PROSPERO registration number: CRD42022371561). The procedure of this protocol will be conducted according to the Preferred Reporting Item for Systematic Review and Meta-analysis Protocols guidance. PubMed, EMBASE, MEDLINE, the Cochrane Library, Chinese National Knowledge Infrastructure, Chinese Biomedical Literature Database, Wanfang Database, ClinicalTrials.gov trials registry, and Chinese Clinical Trial Registry will be searched from January 1980 to November 2022. Two authors will assess methodological quality of included studies separately by the Cochrane collaboration's risk of bias tool. We will apply RevMan 5.4 software for statistical analysis.

RESULTS

This study will provide a high-quality comprehensive evaluation of the efficacy and safety of alendronate and teriparatide for treating patients with glucocorticoid-induced osteoporosis.

CONCLUSION

The conclusion of our systematic review will provide evidence to judge whether teriparatide is an effective intervention for patients with glucocorticoid-induced osteoporosis.

Up-to-Date Knowledge on Osteoporosis Treatment Selection in Postmenopausal Women

The concept of a super-aged society has led to a steady increase in the average lifespan and hence, interest in a healthy life has increased. Aging is a major risk factor for many diseases, including osteoporosis. Osteoporotic fractures have a significant impact on the quality of life of the elderly and hence, it is pivotal to provide effective treatment of osteoporosis after menopause. Osteoporosis requires proper management and the treatment must be centered on long-term goals. New drugs with diverse mechanisms have been developed for treating osteoporosis. Current management of osteoporosis generally focuses on the importance of risk-based strategies to maximize the effectiveness of existing treatments and mitigate potential negative side-effects. Additionally, there is a need for sequential treatment of osteoporosis in the future. This review discusses the dynamic strategies for osteoporosis treatment and the importance of long-term management in postmenopausal women.

Effects and mechanisms of natural alkaloids for prevention and treatment of osteoporosis

Natural alkaloids are polycyclic, nitrogen-containing, and basic compounds obtained from plants. In this review, the advances in bioactive alkaloids with respect to their chemical structures, herbal sources, and effects for the prevention and treatment of osteoporosis are discussed. Anti-osteoporosis alkaloids are classified into six categories based on the chemical structure, namely, isoquinoline alkaloids, quinolizidine alkaloids, piperidine alkaloids, indole alkaloids, pyrrolizidine alkaloids and steroidal alkaloids. They promote mesenchymal stem cells differentiation, improve osteoblast proliferation, stimulate osteoblast autophagy and suppress osteoclast formation. These natural alkaloids can regulate multiple signaling pathways, including interrupting the tumor necrosis factor receptor associated factor 6- receptor activator of nuclear factor kappa B interaction, inhibiting the nuclear factor kappa B pathway in osteoclasts, activating the p38 mitogen-activated protein kinases pathway in osteoblasts, and triggering the wingless and int-1 pathway in mesenchymal stem cells. This review provides evidence and support for novel drug and clinical treatment of osteoporosis using natural alkaloids.

Protective Effect of Rho-Associated Protein Kinase (ROCK) Activated by Bone Marrow Mesenchymal Stem Cells on Bone Strength and Osteoblasts in Rats with Osteoporosis

This study assesses BMSCs’ effect on bone strength and osteoblast activity in rats with osteoporosis. 40 SD female rats were assigned into normal (A) group, model (B) group, puerarin (C) group, and BMSCs (D) group followed by analysis of bone strength by small animal bone strength analyzer and the expression of ROCK1 protein in tibia by immunohistochemistry. The bone strength of group B was lower than group A (P < 0.05), and higher in groups C and D than group B (P < 0.05) with further higher in group D than group C (P < 0.05). Group A showed obvious mesh cancellous bone trabecular bone and continuity, compact structure, and group B cells appeared loose and irregular distribution, parts cancellous bone trabeculae decrease and part of the fracture, and arranged in sparse irregular distribution. The decrease of trabecular bone in group C and D is not more obvious than group B and the morphology in group D got better improved than in group C. Group B showed lower proliferation of osteoblasts and ALP activity than group A (P < 0.05) and the proliferation and ALP activity in groups C and D was increased significantly compared with group B (P < 0.05). ROCK1 expression was significantly lower in group B than group A (P < 0.05) higher in groups C and D than group B (P < 0.05). Bone marrow mesenchymal stem cells (BMSCs) can effectively increase the bone strength and activity of osteoblasts in rats with osteoporosis, and promote the activation of ROCK signal.

Ginsenoside Rb1 prevents osteoporosis via the AHR/PRELP/NF-κB signaling axis

BACKGROUND

Accumulating clinical and experimental evidence shows multiple biological effects of ginsenoside Rb1 (GRb1) in the treatment of aging related diseases such as osteoporosis (OP). Recently, GRb1 has attracted extensive attention as an anti-osteoporosis agent. Here, we sought to identify the mechanism by which GRb1 improves OP.

METHODS

A dexamethasone (DEX)-induced rat model of OP was constructed and the rats were treated with GRb1 to examine its role in OP. We screened the action targets of GRb1 online and validated by performing functional experiments. The correlation between aryl hydrocarbon receptor (AHR) and proline/arginine-rich end leucine-rich repeat protein (PRELP) was identified through luciferase and chromatin immunoprecipitation assays. In the isolated osteoblasts from DEX-induced OP rats, the expression of osteogenic differentiation-associated genes, and nuclear factor-kappa B (NF-κB) pathway-related genes, mineralization, and number of calcium nodules were assessed.

RESULTS

GRb1 enhanced the differentiation of osteoblasts, the mechanism of which was related to upregulation of AHR. AHR could promote the transcription of PRELP by binding to the PRELP promoter region and consequently caused its upregulation. Meanwhile, PRELP inhibited the activation of the NF-κB pathway, which underlay the promoting impact of AHR in the osteogenic differentiation. Additionally, GRb1 could ameliorate OP in DEX-induced rats via the AHR/PRELP/NF-κB axis.

CONCLUSIONS

Our findings demonstrate that GRb1 might function as an effective candidate to prevent the progression of OP via regulation of the AHR/PRELP/NF-κB axis, revealing a new molecular mechanism underpinning the impact of GRb1 in the progression of OP and offering a theoretical contribution to the treatment of OP.

Osteoporosis and Fragility Fractures: currently available pharmacological options and future directions

Osteoporosis is a systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture. The average lifetime risk of a 50-year-old woman to suffer a fracture of the spine, hip, proximal humerus, or distal forearm has been estimated at close to 50%. In general, pharmacological treatment is recommended in patients who suffered a fragility fracture because their risk of suffering a subsequent fracture is increased dramatically. Therefore, many guidelines recommend pharmacological treatment in patients without a prevalent fracture if their fracture probability is comparable to or higher than that of a person of the same age with a prevalent fracture. The present review aims to highlight currently available pharmacological treatment options and their antifracture efficacy including safety aspects. Drug classes discussed comprise bisphosphonates, selective estrogen receptor modulators, parathyroid hormone peptides and derivatives, humanized monoclonal antibodies, and estrogens and gestagens and their combinations. Furthermore, a brief glimpse is provided into a potentially promising treatment option that involves mesenchymal stem cells.

Circulating Osteogenic Progenitor Cells Enhanced with Teriparatide or Denosumab Treatment

Circulating osteogenic precursor (COP) cells are peripheral blood cells with a capacity for osteogenesis. The objective of our study was to ascertain the percentage of COPs as an early biomarker of osteoporosis and the effect of these cells in response to Denosumab (DmAb) (anti-resorptive) or to Teriparatide (TPDP) (anabolic) as very effective drugs in the treatment of the illness. A first study was conducted on healthy volunteers, with three age ranges, to determine the percentage of COPs and relate it to their anthropometric and biochemical characteristics, followed by a second longitudinal study on patients with osteoporosis, whereby one group of patients was treated with TPTD and another with DmAb. All were analyzed by cytometry for COP percentage in blood, bone turnover markers, and bone mass. Our findings show that COPs are influenced by age and become more prolific in the stages of growth and skeletal maturation. A higher percentage of COPs is found in osteoporotic disease, which could constitute a predictive marker thereof. We also show how treatment with TPTD or DmAb mobilizes circulating osteogenic precursors in the blood. Significant increases in % COPs were observed after 12 months of treatment with Dmb (21.9%) and TPTD (17%). These results can be related to an increase in osteogenesis and, consequently, a better and more efficient repair of bone tissue.

Development and validation of a gene signature predicting the risk of postmenopausal osteoporosis

AIMS

We aimed to develop a gene signature that predicts the occurrence of postmenopausal osteoporosis (PMOP) by studying its genetic mechanism.

METHODS

Five datasets were obtained from the Gene Expression Omnibus database. Unsupervised consensus cluster analysis was used to determine new PMOP subtypes. To determine the central genes and the core modules related to PMOP, the weighted gene co-expression network analysis (WCGNA) was applied. Gene Ontology enrichment analysis was used to explore the biological processes underlying key genes. Logistic regression univariate analysis was used to screen for statistically significant variables. Two algorithms were used to select important PMOP-related genes. A logistic regression model was used to construct the PMOP-related gene profile. The receiver operating characteristic area under the curve, Harrell's concordance index, a calibration chart, and decision curve analysis were used to characterize PMOP-related genes. Then, quantitative real-time polymerase chain reaction (qRT-PCR) was used to verify the expression of the PMOP-related genes in the gene signature.

RESULTS

We identified three PMOP-related subtypes and four core modules. The muscle system process, muscle contraction, and actin filament-based movement were more active in the hub genes. We obtained five feature genes related to PMOP. Our analysis verified that the gene signature had good predictive power and applicability. The outcomes of the GSE56815 cohort were found to be consistent with the results of the earlier studies. qRT-PCR results showed that RAB2A and FYCO1 were amplified in clinical samples.

CONCLUSION

The PMOP-related gene signature we developed and verified can accurately predict the risk of PMOP in patients. These results can elucidate the molecular mechanism of RAB2A and FYCO1 underlying PMOP, and yield new and improved treatment strategies, ultimately helping PMOP monitoring.Cite this article: Bone Joint Res 2022;11(8):548-560.

Targeting chronic inflammation as a potential adjuvant therapy for osteoporosis

Systemic, chronic, low-grade inflammation (SCLGI) underlies the pathogenesis of various widespread diseases. It is often associated with bone loss, thus connecting chronic inflammation to the pathogenesis of osteoporosis. In postmenopausal women, osteoporosis is accompanied by SCLGI development, likely owing to estrogen deficiency. We propose that SCGLI persistence in osteoporosis results from failed inflammation resolution, which is mainly mediated by specialized, pro-resolving mediators (SPMs). In corroboration, SPMs demonstrate encouraging therapeutic effects in various preclinical models of inflammatory disorders, including bone pathology. Since numerous data implicate gut dysbiosis in osteoporosis-associated chronic inflammation, restoring balanced microbiota by supplementing probiotics and prebiotics could contribute to the efficient resolution of SCGLI. In the present review, we provide evidence for this hypothesis and argue that efficient SCGLI resolution may serve as a novel approach for treating osteoporosis, complementary to traditional anti-osteoporotic medications.

Identification of osteoporosis based on gene biomarkers using support vector machine

Osteoporosis is a major health concern worldwide. The present study aimed to identify effective biomarkers for osteoporosis detection. In osteoporosis, 559 differentially expressed genes (DEGs) were enriched in PI3K-Akt signaling pathway and Foxo signaling pathway. Weighted gene co-expression network analysis showed that green, pink, and tan modules were clinically significant modules, and that six genes (VEGFA, DDX5, SOD2, HNRNPD, EIF5B, and HSP90B1) were identified as “real” hub genes in the protein–protein interaction network, co-expression network, and 559 DEGs. The sensitivity and specificity of the support vector machine (SVM) for identifying patients with osteoporosis was 100%, with an area under curve of 1 in both training and validation datasets. Our results indicated that the current system using the SVM method could identify patients with osteoporosis.

Efficacy and safety of the biosimilar denosumab candidate (Arylia) compared to the reference product (Prolia®) in postmenopausal osteoporosis: a phase III, randomized, two-armed, double-blind, parallel, active-controlled, and noninferiority clinical trial

Background/objective

Osteoporosis is a global health concern with an increasing prevalence worldwide. Denosumab is an antiresoptive agent that has been demonstrated to be effective and safe in osteoporotic patients. This study aimed to compare the efficacy and safety of the biosimilar denosumab candidate (Arylia) to the originator product (Prolia®) in postmenopausal osteoporotic patients.

Methods

In this randomized, double-blind, active-controlled, noninferiority trial, postmenopausal osteoporotic patients received 60 mg of subcutaneous Arylia or Prolia® at months 0, 6, and 12 and were followed up for 18 months. The primary endpoint was the noninferiority of the biosimilar product to the reference product in the percentage change of bone mineral density (BMD) in 18 months at the lumbar spine (L₁-L₄), total hip, and femoral neck. The secondary endpoints were safety assessment, the incidence of new vertebral fractures, and the trend of bone turnover markers (BTMs).

Results

A total of 190 patients were randomized to receive either biosimilar (n = 95) or reference (n = 95) denosumab. In the per-protocol (PP) analysis, the lower limits of the 95% two-sided confidence intervals of the difference between Arylia and Prolia® in increasing BMD were greater than the predetermined noninferiority margin of − 1.78 at the lumbar spine, total hip, and femoral neck sites (mean differences [95% CIs] of 0.39 [− 1.34 to 2.11], 0.04 [− 1.61 to 1.69], and 0.41 [− 1.58 to 2.40], respectively). The two products were also comparable in terms of safety, new vertebral fractures, and trend of BTMs.

Conclusion

The efficacy of the biosimilar denosumab was shown to be noninferior to that of the reference denosumab, with a comparable safety profile at 18 months.

Trial registration

ClinicalTrials.gov, NCT03293108; Registration date: 2017–09-19.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02840-8.

Mesobiliverdin IXα ameliorates osteoporosis via promoting osteogenic differentiation of mesenchymal stem cells

Heme oxygenase-1 (HO-1) expression promotes osteogenesis, but the mechanisms remain unclear and therapeutic strategies using it to target bone disorders such as osteoporosis have not progressed. Mesobiliverdin IXα is a naturally occurring bilin analog of HO-1 catalytic product biliverdin IXα. Inclusion of mesobiliverdin IXα in the feed diet of ovariectomized osteoporotic mice was observed to increase femur bone volume, trabecular thickness and osteogenesis serum markers osteoprotegrin and osteocalcin and to decrease bone resorption serum markers cross-linked N-teleopeptide and tartrate-resistant acid phosphatase 5b. Moreover, in vitro exposure of human bone marrow mesenchymal stem cells to mesobiliverdin IXα enhanced osteogenic differentiation efficiency by two-fold over non-exposed controls. Our results imply that mesobiliverdin IXα promotes osteogenesis in ways that reflect the potential therapeutic effects of induced HO-1 expression in alleviating osteoporosis.

Assessment of the Therapeutic Potential of Melatonin for the Treatment of Osteoporosis Through a Narrative Review of Its Signaling and Preclinical and Clinical Studies

Melatonin is a bioamine produced primarily in the pineal gland, although peripheral sites, including the gut, may also be its minor source. Melatonin regulates various functions, including circadian rhythm, reproduction, temperature regulation, immune system, cardiovascular system, energy metabolism, and bone metabolism. Studies on cultured bone cells, preclinical disease models of bone loss, and clinical trials suggest favorable modulation of bone metabolism by melatonin. This narrative review gives a comprehensive account of the current understanding of melatonin at the cell/molecular to the systems levels. Melatonin predominantly acts through its cognate receptors, of which melatonin receptor 2 (MT2R) is expressed in mesenchymal stem cells (MSCs), osteoblasts (bone-forming), and osteoclasts (bone-resorbing). Melatonin favors the osteoblastic fate of MSCs, stimulates osteoblast survival and differentiation, and inhibits osteoclastogenic differentiation of hematopoietic stem cells. Produced from osteoblastic cells, osteoprotegerin (OPG) and receptor activator of nuclear factor kappa B ligand (RANKL) critically regulate osteoclastogenesis and melatonin by suppressing the osteoclastogenic RANKL, and upregulating the anti-osteoclastogenic OPG exerts a strong anti-resorptive effect. Although the anti-inflammatory role of melatonin favors osteogenic function and antagonizes the osteoclastogenic function with the participation of SIRT signaling, various miRNAs also mediate the effects of the hormone on bone cells. In rodent models of osteoporosis, melatonin has been unequivocally shown to have an anti-osteoporotic effect. Several clinical trials indicate the bone mass conserving effect of melatonin in aging/postmenopausal osteoporosis. This review aims to determine the possibility of melatonin as a novel class of anti-osteoporosis therapy through the critical assessment of the available literature.