Osteoporosis Model Research Articles

Role of rosuvastatin in bone metabolism of ovariectomized adult rats

The study was planned to explore the influence of one type of hydrophilic statins (rosuvastatin) on the level of serum osteocalcin, N-telopeptide of type 1 collagen (NTx), calcium, and phosphorus. In addition to calcium, phosphorus, and magnesium in femur bone ash of female ovariectomized rats. Thirty female rats aged 2.5-3 months were divided as follows, sham group, ovariectomized (ovx) group as a model of osteoporosis, and (ovx) group treated with 20mg /kg of rosuvastatin for 60 days. Blood samples were collected after 30 and 60 days of the experiment for biochemical analysis. Besides, after 60 days of the treatment, right femur bones were excised and ashed to estimate calcium, phosphorus, and magnesium. The results showed a significant elevation in serum osteocalcin, (NTx), calcium, and phosphorus, in addition to elevation in osteoclasts number and deceased osteoblasts and thickness of trabecular bone in the (ovx) group compared to the sham, while treatment with rosuvastatin caused a significant reduction in osteocalcin, (NTx), calcium and phosphorus after 60 days. Also, the results revealed a significant reduction in the percentage of (Ca, P and Mg) content in bone ash of the (ovx) group compared to the sham group. However, rosuvastatin treatment led to a significant elevation in the percentage of calcium and inorganic phosphate in bone ash and increased the thickness of trabecular bone and development in osteocytes compared with ovariectomized rats. The conclusion of the present study, rosuvastatin has a positive effect on the bone of ovariectomized rats.

Pilose antler (Cervus elaphus Linnaeus) polysaccharide and polypeptide extract inhibits bone resorption in high turnover type osteoporosis by stimulating the MAKP and MMP-9 signaling pathways

Ethnopharmacological relevancePilose antler is a traditional Chinese medicine used to improve kidney function, strengthen tendons and bones, and prolong life, among other uses. It is widely employed in the treatment of osteoporosis. However, the molecular mechanisms underlying the treatment of high turnover osteoporosis are not fully understood. Aim of the studyThe present study aimed to investigate the molecular mechanism underlying pilose antler polysaccharide and polypeptide extracts in inhibiting bone resorption in high turnover osteoporosis, and compare the effects of the two components alone and in combination to explore whether they could produce synergistic enhancement effects. Materials and methodsThe quantitative and qualitative characteristics of pilose antler polysaccharide and polypeptide extracts were detected by UV–visible spectrophotometry and high-performance liquid chromatography. A rat model of retinoic acid-induced osteoporosis was used to evaluate the inhibitory effect of the extracts on bone resorption. Enzyme-linked immunosorbent assay (ELISA) was used to detect the activity of factors related to high turnover type osteoporosis in rat serum. Western blotting was used to detect the expression of proteins related to the MAKP and MMP-9 signaling pathways in rat femurs. Fluorescence quantitative PCR was used to detect the transcription levels of genes related to the MAKP and MMP-9 signaling pathways in rat femur tissues. Hematoxylin and eosin staining were used to observe the osteoprotective effects of pilose antler polysaccharides and polypeptides. ResultsThe yield of pilose antler polysaccharides was 8.3%, and was mainly composed of mannose, glucosamine hydrochloride, glucuronic acid, Galacturonic acid, Galactose hydrochloride, glucose, and galactose. The yield of the polypeptides was 26.2%, and eighty percent of the molecular weight of the antler polypeptides was 1.6 kDa-7kD, among which, the molecular weight of 7kD peptide accounted for 52% of the total. Both polysaccharides and peptides could reduce the activities of TRACP, OCN, ERK1, JNK, and MMP-9 in rat serum and reduce both the protein expression and gene transcription levels of ERK1, JNK, and MMP-9 in rat femur tissue with significant differences compared with the model group. Both extracts exerted significant protective effects on rat femur tissue. The effect of pilose antler polypeptides alone was better than that of polysaccharides either alone or in combination. ConclusionsPilose antler polysaccharides, polypeptides, and their mixtures could inhibit the occurrence of bone resorption of high turnover osteoporosis by stimulating the MAKP and MMP-9 signaling pathways to reduce the expression of the ERK1, JNK, and MMP-9 genes and proteins, and could help alleviate bone loss caused by retinoic acid. Pilose antler polypeptides had a stronger effect on inhibiting bone resorption. The combination of the two components did not show synergistic enhancement effect, and the polysaccharide tended to moderate the inhibitory enhancement effect of the polypeptide.

Laccase Domain-Containing Protein 1 Promoted Inflammation of Osteoporosis Model via NOD2 Ubiquitination by RIP2

The purpose of this experiment was to elucidate the latent influence of Laccase Domain-Containing Protein 1 (LACC1) regulatory loop in the progression of osteoporosis. Serum samples of volunteers were obtained from the researchers’ hospital. Mice were induced by an osteoporosis model using ovariectomy. LACC1 mRNA expression levels were up-regulated in patients with osteoporosis. LACC1 protein and mRNA expression levels in mice with osteoporosis were measured. LACC1 promoted inflammation of osteoporosis in the in vitro model. LACC1 promoted osteoporosis in the mice model. LACC1 protein interlinked nucleotide-binding oligomerisation domain 2 (NOD2)/ receptor interacting protein 2 (RIP2) protein to reduce ubiquitination of NOD2. NOD2/RIP2 participated in the effects of LACC1 in the model of osteoporosis. These findings suggest that LACC1 promoted inflammation of the osteoporosis model via the induction of NOD2-RIP2 signalling by the inhibition of NOD2 ubiquitination. The inhibition of LACC1 regulatory loop provides new targets for treatment of osteoporosis.

Integrated proteomics and metabolomics analysis of lumbar in a rat model of osteoporosis treated with Gushukang capsules

BackgroundGushukang (GSK) capsules are a Chinese patented medicine that is widely used in clinics for the treatment of osteoporosis (OP). Animal experiments have revealed that the bone mineral density of osteoporotic rats increase after treatment with GSK capsules. However, the specific mechanism and target of GSK in the treatment of osteoporosis are unclear. Further studies are needed.MethodsMetabolomics (GC/MS) and proteomics (TMT-LC-MC/MC) with bioinformatics (KEGG pathway enrichment), correlation analysis (Pearson correlation matrix), and joint pathway analysis (MetaboAnalyst) were employed to determine the underlying mechanisms of GSK. The differential expression proteins were verified by WB experiment.ResultsThe regulation of proteins, i.e., Cant1, Gstz1, Aldh3b1, Bid, and Slc1a3, in the common metabolic pathway of differential proteins and metabolites between GSK/OP and OP/SHAM was corrected in the GSK group. The regulation of 12 metabolites (tyramine, thymidine, deoxycytidine, cytosine, L-Aspartate, etc.) were differential in the common enrichment metabolic pathway between GSK /OP and OP/SHAM. Differential proteins and metabolites jointly regulate 11 metabolic pathways, such as purine metabolism, pyrimidine metabolism, histidine metabolism, beta-alanine metabolism, and so on.ConclusionGSK may protect bone metabolism in osteoporotic rats by affecting nucleotide metabolism, amino acid metabolism, and the immune system.

Gut microbiota and fecal metabolic signatures in rat models of disuse-induced osteoporosis.

Assessing the correlation between gut microbiota (GM) and bone homeostasis has increasingly attracted research interest. Meanwhile, GM dysbiosis has been found to be associated with abnormal bone metabolism. However, the function of GM in disuse-induced osteoporosis (DIO) remains poorly understood. In our research, we evaluated the characteristics of GM and fecal metabolomics to explore their potential correlations with DIO pathogenesis. DIO rat models and controls (CON) underwent micro-CT, histological analyses, and three-point bending tests; subsequently, bone microstructures and strength were observed. ELISAs were applied for the measurement of the biochemical markers of bone turnover while GM abundance was observed using 16S rDNA sequencing. Metabolomic analyses were used to analyze alterations fecal metabolites. The potential correlations between GM, metabolites, and bone loss were then assessed. In the DIO group, the abundance of GM was significantly altered compared to that in the CON group. Moreover, DIO significantly altered fecal metabolites. More specifically, an abnormally active pathway associated with bile acid metabolism, as well as differential bacterial genera related to bone/tissue volume (BV/TV), were identified. Lithocholic acid, which is the main secondary bile acid produced by intestinal bacteria, was then found to have a relationship with multiple differential bacterial genera. Alterations in the intestinal flora and metabolites in feces, therefore, may be responsible for DIO-induced bone loss. The results indicated that changes in the abundance of GM abundance and fecal metabolites were correlated with DIO-induced bone loss, which might provide new insights into the DIO pathogenesis. The detailed regulatory role of GM and metabolites in DIO-induced bone loss needs to be explored further.

Remarkable Plasticity of Bone Iron Homeostasis in Hibernating Daurian Ground Squirrels (Spermophilus dauricus) May Be Involved in Bone Maintenance.

Iron overload is an independent risk factor for disuse osteoporosis. Hibernating animals are natural models of anti-disuse osteoporosis; however, whether iron metabolism is involved in bone adaptation and maintenance during hibernation is unclear. To investigate this question, Daurian ground squirrels (Spermophilus dauricus) (n = 5-6/group) were used to study changes in bone iron metabolism and its possible role in anti-disuse osteoporosis during hibernation. Iron content in the femur and liver first decreased in the torpor group (vs. summer group, -66.8% and -25.8%, respectively), then recovered in the post-hibernation group, suggesting remarkable plasticity of bone iron content. The expression of ferritin in the femur and hepcidin in the liver also initially decreased in the torpor group (vs. summer group, -28.5% and -38.8%, respectively), then increased in the inter-bout arousal (vs. torpor group, 126.2% and 58.4%, respectively) and post-hibernation groups (vs. torpor group, 153.1% and 27.1%, respectively). In conclusion, bone iron metabolism in hibernating Daurian ground squirrels showed remarkable plasticity, which may be a potential mechanism to avoid disuse bone loss during extended periods of inactivity. However, the specific location of iron during low-iron hibernation and the source of iron in post-hibernation recovery need to be further explored.

Biomechanical Effect of Osteoporosis on Adjacent Segments After Anterior Cervical Corpectomy and Fusion

Adjacent segmental degeneration (ASD) is one common long-term complication of anterior cervical corpectomy and fusion (ACCF), and osteoporosis is one basic disease in the elderly. After ACCF, patients may experience osteoporosis with age. However, the influence of osteoporosis on ASD remains unclear. The purpose of this study was to determine whether osteoporosis could affect the development of ASD following ACCF. Three finite element models of the cervical spine, including 1 normal model, 1 ACCF model, and 1 ACCF with osteoporosis model, were constructed. ACCF was simulated at the C4-C6 level. A 73.6N follower load and a 1 Nm moment were imposed on the normal model, and the same follower load together with an adjusted moment was applied to the ACCF model and the ACCF with osteoporosis model, to simulate movement in each direction. The range of motion, intradiscal pressure, shear stress on anulus fibrosus, and facet joint stress at C3-C4 and C6-C7 levels of the models were calculated. In this study, the normal model was well validated. In flexion, extension, right lateral bending, and right axial rotation, the overall range of motion was 8.92°, 19.7°, 15.37°, and 45.27° in the normal model, and the adjusted moment was 1.4 Nm, 2.7 Nm, 1.1 Nm, and 2.6 Nm in the ACCF model, and 1.3 Nm, 2.5 Nm, 1.1 Nm, and 2.4 Nm in the ACCF with osteoporosis model. Despite of a few exceptions, the maximum values of the outcome measurements were mostly found in the ACCF model, and the minimum values in the normal model. Compared with the ACCF model, most of the outcome measurements were decreased in the ACCF with osteoporosis model. Osteoporosis can retard the adverse influence of ACCF on adjacent segments.

Stepwise reduction of bone mineral density increases the risk of cage subsidence in oblique lumbar interbody fusion patients biomechanically: an in-silico study

BackgroundCage subsidence causes poor prognoses in patients treated by oblique lumbar interbody fusion (OLIF). Deterioration of the biomechanical environment initially triggers cage subsidence, and patients with low bone mineral density (BMD) suffer a higher risk of cage subsidence. However, whether low BMD increases the risk of cage subsidence by deteriorating the local biomechanical environment has not been clearly identified.MethodsOLIF without additional fixation (stand-alone, S-A) and with different additional fixation devices (AFDs), including anterolateral single rod screws (ALSRs) and bilateral pedicle screws (BPSs) fixation, was simulated in the L4-L5 segment of a well-validated finite element model. The biomechanical effects of different BMDs were investigated by adjusting the material properties of bony structures. Biomechanical indicators related to cage subsidence were computed and recorded under different directional moments.ResultsOverall, low BMD triggers stress concentration in surgical segment, the highest equivalent stress can be observed in osteoporosis models under most loading conditions. Compared with the flexion-extension loading condition, this variation tendency was more pronounced under bending and rotation loading conditions. In addition, AFDs obviously reduced the stress concentration on both bony endplates and the OLIF cage, and the maximum stress on ALSRs was evidently higher than that on BPSs under almost all loading conditions.ConclusionsStepwise reduction of BMD increases the risk of a poor local biomechanical environment in OLIF patients, and regular anti-osteoporosis therapy should be considered an effective method to biomechanically optimize the prognosis of OLIF patients.

Novel alendronate-CGS21680 conjugate reduces bone resorption and induces new bone formation in post-menopausal osteoporosis and inflammatory osteolysis mouse models.

Loss of bone is a common medical problem and, while it can be treated with available therapies, some of these therapies have critical side effects. We have previously demonstrated that CGS21680, a selective A2A adenosine receptor agonist, prevents bone loss, but its on-target toxicities (hypotension, tachycardia) and frequent dosing requirements make it unusable in the clinic. We therefore generated a novel alendronate-CGS21680 conjugate (MRS7216), to target the agonist to bone where it remains for long periods thereby diminishing the frequency of administration and curtailing side effects. MRS7216 was synthesized from CGS21680 by sequential activation of the carboxylic acid moiety and reacting with an appropriate amino acid (PEG, alendronic acid) under basic conditions. MRS7216 was tested on C57BL/6J (WT) mice with established osteoporosis (OP) and WT or A2A KO mice with wear particle-induced inflammatory osteolysis (OL). Mice were treated weekly with MRS7216 (10mg/kg). Bone formation was studied after in vivo labeling with calcein/Alizarin Red, and μCT and histology analyses were performed. In addition, human primary osteoblasts and osteoclasts were cultured using bone marrow discarded after hip replacement. Receptor binding studies demonstrate that MRS7216 efficiently binds the A2A adenosine receptor. MRS7216-treated OP and OL mice had significant new bone formation and reduced bone loss compared to vehicle or alendronate-treated mice. Histological analysis showed that MRS7216 treatment significantly reduced osteoclast number and increased osteoblast number in murine models. Interestingly, cultured human osteoclast differentiation was inhibited, and osteoblast differentiation was stimulated by the compound indicating that MRS7216 conjugates represent a novel therapeutic approach to treat osteoporosis and osteolysis.

Glucagon-Like Peptide-2 Ameliorates Age-Associated Bone Loss and Gut Barrier Dysfunction in Senescence-Accelerated Mouse Prone 6 Mice

Introduction: Senile osteoporosis is one of the most common age-related diseases worldwide. Glucagon like peptide-2 (GLP-2), a naturally occurring gastrointestinal peptide, possesses therapeutic effects on bone loss in postmenopausal women and ovariectomized rats. However, the role of GLP-2 in senile osteoporosis and underlying mechanisms has not been explored. Methods: GLP-2 was subcutaneously injected into the 6-month-old male senile osteoporosis model of senescence-accelerated mouse prone 6 (SAMP6) mice for 6 weeks. SAMP6 subjected to normal saline and senescence-accelerated mouse resistant 1 served as control groups. Micro-computed tomography was performed to evaluate the bone mass and microarchitecture of the mice. Osteoblastic and osteoclastic activities were determined by biochemical, quantitative real-time PCR, histological, and histomorphometric analyses combined with hematoxylin-eosin, toluidine blue, and tartrate-resistant acid phosphatase staining. We also examined the proteins and structure of intestinal tight junction using immunohistochemical assay as well as a transmission electron microscope. Serum inflammation marker levels were measured using ELISA. Additionally, anti-oxidative enzymes GPX-4 and SOD-2 and receptors of GLP-2 and vitamin D expression in the ileum and colon were detected under immunofluorescence staining. Results: Six-week GLP-2 treatment attenuated bone loss in SAMP6 mice, as evidenced by increased bone mineral density, improved microarchitecture in femora, and enhanced osteogenic activities. In contrast, the activity of osteoclastic activity was not obviously inhibited. Moreover, GLP-2 ameliorated tight junction structure and protein expression in the intestinal barrier, which was accompanied by the reduction of TNF-α level. The expression of receptors of intestinal GLP-2 and vitamin D in the ileum was elevated. Furthermore, the oxidative stress in the intestines was improved by increasing the GPX-4 and SOD-2 signaling. Conclusion: Our findings suggest that GLP-2 could ameliorate age-associated bone loss, tight junction structure, and improved antioxidant enzyme activity in the gut in SAMP6 mice. Amelioration of gut barrier dysfunction may potentially contribute to improving bone formation and provide evidence for targeting the entero-bone axis in the treatment of senile osteoporosis.

P53 Regulates Osteogenic Differentiation Through miR-153-5p/miR-183-5p-X-Linked IAP (XIAP) Signal in Bone Marrow Mesenchymal Stem Cell (BMSC)

This study assessed P53′s role in BMSC osteogenic differentiation. Osteoporosis model was established and P53 expression in the osteogenic differentiation was detected by RT-PCR. BMSC was cultivated and transfected with siRNA followed by measuring presentation of osteogenic differentiation was detected after cells were. The apoptotic condition of osteogenic differentiation was detected through IF method and protein analysis. The relation between P53 and miR-153-5p/miR-183-5p-XIAP signal axis was detected through bioinformatics and luciferase reporter gene assay. P53 expression was significantly increased after osteogenic differentiation was induced. There was a binding site between P53 and miR-153-5p/miR-183-5p-XIAP signal axis. The apoptotic ability of osteoblast was enhanced after inhibition of the expression of P53. In conclusion, P53 develops crucial action on the regulation of BMSC osteogenic differentiation through miR-153-5p/miR-183-5p-XIAP axis.

Risk of primary osteoporosis score (RPOPs): an algorithm model for primary osteoporosis risk assessment in grass-roots hospital

BackgroundThis study aimed to develop and validate a lasso regression algorithm model which was established by correlation factors of bone mineral density (BMD) and could be accurately predicted a high-risk population of primary osteoporosis (POP). It provides a rapid, economical and acceptable early screening method for osteoporosis in grass-roots hospitals.MethodsWe collected 120 subjects from primary osteoporosis screening population in Zhejiang Quhua Hospital between May 2021 and November 2021 who were divided into three groups (normal, osteopenia and osteoporosis) according to the BMD T-score. The levels of three micro-RNAs in the plasma of these people were detected and assessed by qRT-PCR. At the same time, the levels of β-CTX and t-P1NP in serum of the three groups were determined. Based on the cluster random sampling method, 84 subjects (84/120, 70%) were selected as the training set and the rest were the test set. Lasso regression was used to screen characteristic variables and establish an algorithm model to evaluate the population at high risk of POP which was evaluated and tested in an independent test cohort. The feature variable screening process was used 10-fold cross validation to find the optimal lambda.ResultsThe osteoporosis risk score was established in the training set: Risk of primary osteoporosis score (RPOPs) = -0.1497785 + 2.52Age − 0.19miR21 + 0.35miR182 + 0.17β-CTx. The sensitivity, precision and accuracy of RPOPs in an independent test cohort were 79.17%, 82.61% and 75%, respectively. The AUC in the test set was 0.80. Some risk factors have a significant impact on the abnormal bone mass of the subjects. These risk factors were female (p = 0.00013), older than 55 (p < 2.2e-16) and BMI < 24 (p = 0.0091) who should pay more attention to their bone health.ConclusionIn this study, we successfully constructed and validated an early screening model of osteoporosis that is able to recognize people at high risk for developing osteoporosis and remind them to take preventive measures. But it is necessary to conduct further external and prospective validation research in large sample size for RPOPs prediction models.

Effect of Desmodium renifolium on ovariectomized rat model of osteoporosis via BMP-2/Smads signaling pathway

This study aimed to investigate the effect of Desmodium renifolium(Linn.) Schindl on ovariectomized rat model of osteoporosis and explore the underlying mechanism. Rats were randomized into a sham group, a model group, a Xianlin Gubao group, and low-, medium-, and high-dose D. renifolium groups. Bilateral oophorectomy was performed in other groups except sham group(removal of bilateral peri-ovarian adipose tissue). The sham group and model group were administrated with equal volume of 0.5% CMC-Na, Xianlin Gubao group with Xianlin Gubao, and D. renifolium groups with different concentrations of alcoholic extract of D. renifolium once a day for 14 weeks. The body weight of rats were recorded during the experiment. The levels of estradiol(E_2), 1,25-dihydroxyvitamin D_3 [1,25(OH)_2D_3], calcium(Ca), and phosphorus(P) in serum were determined after the administration. The femur microstructure was analyzed via micro-CT. RT-PCR and Western blot were employed to respectively determine the mRNA and protein levels of bone morphogenetic protein 2(BMP-2), Runt-related transcription factor 2(Runx2), and osterix(OSX) in the tibia of rats. The results indicated that D. renifolium significantly inhibited the weight growth, improved the uterus appearance, elevated the levels of E_2, Ca, P, and 1,25(OH)_2D_3 in serum, increased the number and reduced the fracture of bone trabeculae, ameliorated the bone microstructure parameters, and up-regulated the mRNA and protein levels of BMP-2, Runx2, and OSX. All the results demonstrated that D. renifolium had significant protective effect on the ovariectomized rat model of osteoporosis by regulating the BMP-2/Smads signaling pathway.

Eucommia Ulmoides Extracts Exert Protective Effect on Osteoporosis in Rats

Our study proposed to probe the therapeutic effect of Eucommia ulmoides extracts (EUE) on osteoporosis in rats and the potential mechanism. Castrated osteoporosis model was constructed in rats, followed by orally administrated with 50, 100, and 200 mg/kg EUE per day for one and half months, with sham animals as the negative control. The pathological conditions of femur were detected by HE staining, while the apoptotic state was evaluated by TUNEL. ELISA was utilized to measure the serum level of IL-6, calcium, and phosphorus. Significantly damaged bone trabecular structure and aggravated apoptosis were observed in castrated osteoporosis model rats, which were markedly alleviated by the administration of EUE. Furthermore, compared to control, the serum level of phosphorus was greatly declined and the IL-6 level was dramatically increased in castrated osteoporosis model rats, which were reversed by the administration of EUE. Taken together, EUE improved the pathological state of the femur tissue in osteoporosis rats by regulating the levels of phosphorus and IL-6 in serum and inhibited the apoptosis of the femur tissue cells, which effectively alleviated the osteoporosis induced by estrogen deficiency.

Commentary: Zebrafish as a Model for Osteoporosis—An Approach to Accelerating Progress in Drug and Exercise-Based Treatment

Osteoporosis (OP) is a degenerative disease characterized by reduced bone strength and increased fracture risk. As the global population continues to age, the prevalence and economic burden of osteoporosis can be expected to rise substantially, but there remain various gaps in the field of OP care. For instance, there is a lack of anti-fracture drugs with proven long-term efficacy. Likewise, though exercise remains widely recommended in OP prevention and management, data regarding the safety and efficacy for patients after vertebral fracture remain limited. This lack of evidence may be due to the cost and inherent difficulties associated with exercise-based OP research. Thus, the current research landscape highlights the need for novel research strategies that accelerate OP drug discovery and allow for the low-cost study of exercise interventions. Here, we outline an example of one strategy, the use of zebrafish, which has emerged as a potential model for the discovery of anti-osteoporosis therapeutics and study of exercise interventions. The strengths, limitations, and potential applications of zebrafish in OP research will be outlined.

ANALYSIS OF UTERINE MORPHOLOGY IN OVARIECTOMIZED RATS TREATED WITH ALENDRONATE AND HOP EXTRACT USING OPEN-SORUCE SOFTWARE

Free and open-source software for image analysis and morphological measurements in scientific research is rising in popularity and capabilities as new methods, plugins and macros are being actively developed. A semi-automated method for measuring rat uterus morphology using free and open-source software (Gimp and FIJI) is demonstrated in this paper. Research was performed on ovariectomized rats as a model of osteoporosis (with sham-operated control group). The animals were treated with alendronate, hop extract or the combination of the two. Whole histological slides were photographed and images were manually pre-processed in Gimp. Color masks from Gimp were loaded in FIJI and polar transformation and measurements were made using a custom macro. This analysis was supplemented by manual assessment of Ki67 proliferation marker expression by a pathologist. Our results suggest that monotherapy or combination therapy with alendronate and hop extract does not cause proliferation of the endometrium in ovariectomized rats and would be safe for use in osteoporosis treatment in this regard. The semi-automated method used in this research is more precise and unbiased than older manual methods. Furthermore, it can be easily adapted for analysis of whole-slide images of almost any round or oval organ.

An Orthopaedic Surgeon Led Osteoporosis (OSLO) Model of Care reduces early recurrent fracture rates and improves treatment compliance in patients treated for osteoporotic fractures.

This study aims to evaluate the efficacy of an Orthopaedic Surgeon Led Osteoporosis Model of Care (OSLO-MoC) as compared to a Case Manager Led Osteoporosis Model of Care (CMLO-MoC) in reducing early osteoporotic re-fracture rates and treatment compliance in patients. This was a single centre, retrospective, comparative cohort study of all patients screened and treated for secondary osteoporotic fracture prevention from the 2008 to 2018 at an orthopaedic surgical unit. From the 2008 to 2013, patients were recruited under the CMLO-MoC and from 2014 to 2018, under the OSLO-MOC. Logistics regression analysis was used to identify significant predictors such as OSLO-MOC implementation, gender, ethnicity, marital status and education level for patient recruitment, treatment compliance and secondary fracture rates at 12-month follow-up. Over a 10-year period, 7388 patients were screened of which 2855 patients were eligible for analysis. A total of 1234 patients were recruited under CMLO-MoC and 1621 patients under OSLO-MOC. Implementation of the OSLO-MOC was associated with greater patient recruitment, OR 1.26 (95%CI 1.06-1.49, P = 0.007). Of the 2855 patients recruited, OSLO-MOC implementation, OR 2.61 (95%CI 2.03-3.36, P < 0.001), and a higher level of education, OR 1.428 (95%CI 1.02-1.43, P = 0.037), were associated with improved compliance to medication at 12months. OSLO-MOC implementation was the only factor associated with reduced risk of secondary fractures at 12months, OR 0.14 (95%CI 0.03-0.66, P = 0.013). The OSLO-MOC has shown to be effective in reducing the rate of re-fracture and osteoporotic medication initiation and compliance of patients. IV.

METTL14 upregulates TCF1 through m6A mRNA methylation to stimulate osteogenic activity in osteoporosis.

Alteration of N6-methyladenosine (m6A) is closely linked to spanning biological processes including osteoporosis (OP) development. This research focuses on the function of methyltransferase like 14 (METTL14) in bone turnover and its interaction with T cell factor 1 (TCF1). A mouse model of OP was established by ovariectomy (OVX). The bone mass parameters were evaluated by micro-CT analysis. Mouse MC3T3-E1 cells and mouse bone marrow macrophages (BMMs) were induced for osteogenic or osteoclastic differentiation, respectively, for in vitro experiments. The osteogenesis or osteoclasis activity was analyzed by measuring the biomarkers such as OPG, ALP, NFATC1, CTSK, RANKL, and TRAP. RT-qPCR and IHC assays identified reduced METTL14 expression in bone tissues of osteoporotic patients and ovariectomized mice. Artificial METTL14 overexpression increased bone mass of mice and promoted osteogenesis whereas suppressed osteoclasis both in vivo and in vitro. METTL14 promoted TCF1 expression through m6A mRNA methylation, and TCF1 increased the osteogenic activity by elevating the protein level of RUNX2, a key molecule linked to bone formation. In rescue experiments, TCF1 restored the RUNX2 level and osteogenic activity of cells suppressed by METTL14 silencing. In summary, this research demonstrates that METTL14 plays a protective role against OP by promoting the TCF1/RUNX2 axis.

A Novel RANKL-Targeted Furoquinoline Alkaloid Ameliorates Bone Loss in Ovariectomized Osteoporosis through Inhibiting the NF-κB Signal Pathway and Reducing Reactive Oxygen Species.

Dysregulation of osteoclast-osteoblast balance, resulting in abnormal bone remodeling, is responsible for postmenopausal osteoporosis (PMOP) or other secondary forms of osteoporosis. We demonstrated that dictamnine (DIC), a novel RANKL-targeted furoquinoline alkaloid, inhibits osteoclastogenesis by facilitating the activities of reactive oxygen species (ROS), NF-κB, and NFATc1 in vitro and prevents the development of OVX-induced osteoporosis mouse models in vivo. Methods. The docking mechanism of DIC and RANKL was initially identified by protein-ligand molecular docking. RNA sequencing was performed and analyzed to reveal the potential mechanism and signaling pathway of the antiosteoporosis effects of DIC. To verify the sequencing results, we examined the impact of DIC on RANKL-induced osteoclast differentiation, bone resorption, F-actin ring production, ROS generation, and NF-κB activation in osteoclasts in vitro. Moreover, a luciferase assay was performed to determine the binding and transcriptional activity of Nrf2 and NF-κB. The in vivo efficacy of DIC was assessed with an ovariectomy- (OVX-) induced osteoporosis model, which was analyzed using micro-CT and bone histomorphometry. Results. The molecular docking results indicated that DIC could bind particularly to RANKL. RNA-seq confirmed that DIC could regulate the osteoclast-related pathway. DIC suppressed osteoclastogenesis, bone resorption, F-actin belt formation, osteoclast-specific gene expression, and ROS activity by preventing NFATc1 expression and affecting NF-κB signaling pathways in vitro. The luciferase assay showed that DIC not only suppressed the activity of Nrf2 but also contributed to the combination of Nrf2 and NF-κB. Our in vivo study indicated that DIC protects against OVX-induced osteoporosis and preserves bone volume by inhibiting osteoclast activity and function. Conclusions. DIC can ameliorate osteoclast formation and OVX-induced osteoporosis and therefore is a potential therapeutic treatment for osteoporosis.

SDH5 down-regulation mitigates the damage of osteoporosis via inhibiting the MyD88/NF-κB signaling pathway

Background Osteoporosis has become a serious public health problem especially in postmenopausal women. This work aims to assess both the function and mechanism of SDH5 in osteoporosis. Methods The animal model of osteoporosis in sprague-dawley rats was established by ultilizing Ovariectomy (OVX). The trabecular bone morphometry had been determined by micro-CT, and tibia injury of rats was detected through HE and alcian blue staining. Meanwhile, the levels of oxidative stress factors, including MDA, CAT, GSH-Px, and SOD, were detected by ELISA. The proliferation and apoptosis of osteoblasts isolated from OVX-induced rats were found out by CCK-8 and flow cytometry respectively. The expression of SDH5, Osterix (Osx), Type I collagen (CoL1A1), osteocalcin (OC), SOD1, SOD2, p-MyD88/MyD88, and p-NF-κB p65/NF-κB p65 was assessed by Western blot. The effect and mechanism of SDH5 knockdown on osteoporosis were verified by lipopolysaccharide (LPS) treatment. Results In the osteoporosis rat model, the expression of SDH5 had an up-regulated tend. A higher bone mineral density (BMD) value was found in the SDH5 knockdown group. SDH5 inhibition ameliorated bone loss, mitigated bone histopathological injury, alleviated oxidative stress, and elevated osteogenic marker protein expression in vivo and in vitro. SDH5 down-regulation also promoted the proliferation and restrained apoptosis of osteoblasts extracted from OVX-induced rats. Furthermore, we found that the underlying mechanism was associated with the inhibition of the MyD88/NF-κB pathway. Conclusion Down-regulation of SDH5 mitigates the damage of osteoporosis both in vivo and in vitro via inhibiting the MyD88/NF-κB signaling activation.