Fufang Zhenshu Tiaozhi capsule enhances bone formation and safeguards against glucocorticoid-induced osteoporosis through innovative Mekk2-mediated ß-catenin deubiquitination.

INTRODUCTION: Bone homeostasis depends on the regulation of ß-catenin in osteoblasts. Glucocorticoids (GCs) are known to diminish ß-catenin activity via Wnt pathway signaling, leading to osteoporosis. Conversely, activating ß-catenin in osteoblasts through mitogen-activated protein kinase kinase kinase 2 (Mekk2) offers an innovative approach to combat GC-induced osteoporosis (GIOP). Fufang Zhenshu Tiaozhi (FTZ) capsules have shown effectiveness in treating GIOP, but the mechanisms behind this are still unclear. MATERIALS AND METHODS: In this study, Mekk2 knockout mice (Mekk2-/-) was generated by CRISPR/Cas9. These mice were then subjected to Alcian Blue-Alizarin Red staining and immunofluorescence to assess their bone and cartilage development. To establish models of GIOP, both Mekk2-/- and wild-type (WT) mice were treated with dexamethasone (DXMS) and subsequently given FTZ capsules. We analyzed the resulting phenotypic changes in these mice using Micro-CT scans and histomorphological studies. Primary osteoblasts, isolated from both Mekk2-/- and WT mice, underwent qRT-PCR to measure key osteogenesis markers, including Runx2, Sp7, Bgalp, Col1a1 and Alp. Cells were then exposed to treatments with either FTZ or Wnt3a and the phosphorylation levels of ß-catenin and Mekk2, along with the protein expression of Runx2, were evaluated using Western blotting and immunoprecipitation. Additionally, C3H10T1/2 cells transfected with TOPflash-luciferase and Renilla luciferase reporters were treated with FTZ and Wnt3a to measure ß-catenin activity. RESULTS: In our study, administering FTZ in vivo effectively prevented bone loss typically induced by GCs. However, it's important to note that this protective effect was substantially reduced in mice lacking Mekk2. Additionally, FTZ showed a significant ability to enhance osteogenic differentiation in primary osteoblasts, doing so by altering the expression of Mekk2. Intriguingly, the impact of FTZ on Mekk2 appears to function through a pathway separate from the traditional Wnt signaling route. Furthermore, our findings indicate that FTZ also promotes the deubiquitination of ß-catenin, contributing further to its positive effects on bone health. CONCLUSIONS: This study suggests that FTZ plays a significant role in protecting bone mass in cases of GIOP. The mechanism through which FTZ confers this benefit involves the activation of Mekk2/ß-catenin signaling pathways, which represents a promising alternative strategy to counteract the deleterious effects of GIOP by augmenting osteoblastogenesis.

Diagnostic value of necrotic lesion boundary in bone collapse of femoral head osteonecrosis.

PURPOSE: Our research developed a novel approach to quantitatively evaluate the boundary of necrotic lesions in osteonecrosis of the femoral head (ONFH) and to explore its diagnostic value in predicting bone collapse of the femoral head. METHODS: A retrospective cross-sectional study was conducted in our institution, and 146 hips (121 cases) identified as ONFH were recruited. The anterior and lateral boundaries of each enrolled subject were measured in standard anteroposterior (AP) view and frog-leg (FL) view of plain radiographic images, the intact rate of which was then calculated and presented as the anteroposterior view intact ratio (APIR) and frog-leg view intact ratio (FLIR), respectively. Univariate and multivariate logistic regression analyses were performed to identify risk factors for collapse. A receiver operating characteristic (ROC) curve analysis was performed to determine the sensitivity, specificity and cutoff value of the APIR and FLIR. A Kaplan-Meier (K-M) analysis was applied to calculate the survival rate of the femoral head, and bone collapse of the femoral head was regarded as the endpoint. RESULTS: Femoral head collapse was observed in 61 hips during the follow-up period. Patients with or without femoral head collapse were categorized into the collapse group and non-collapse group, respectively. The mean follow-up time was 3.7 years (2-9) for the collapse group and 7.7 years (5-20) for the non-collapse group. Univariate and multivariate logistic regression analysis and ROC analysis showed that APIR (< 25.61%) and FLIR (< 24.43%) were significantly associated with femoral head collapse. The K-M survival curves indicated that the overall survival rate of APIR (≥ 25.61%) was 94.8% at 7.5 years and 76.6% at 10 years, while that of FLIR (≥ 24.43%) was 87.3% at 7.5 years and ten years. CONCLUSION: The present study demonstrates that APIR and FLIR are of high diagnostic value in the early and middle stages of ONFH. APIR and FLIR can be used to predict the occurrence of femoral head collapse in patients with JIC classification types B and C1. The measurement of these two parameters in plain radiography images may contribute to the selection of a proper hip preservation strategy.

Cumambrin A prevents OVX-induced osteoporosis via the inhibition of osteoclastogenesis, bone resorption, and RANKL signaling pathways.

Being the principal cells responsible for bone resorption and pathologic bone loss, osteoclasts have become the main target for antiresorptive treatment. Cumambrin A is a natural compound isolated from Chrysanthemum indicum L. and belongs to a member of the sesquiterpene lactone family. To date, the therapeutic effect of cumambrin A on osteoporosis and its mechanisms of action are not known. In this study, we found that cumambrin A can significantly inhibit osteoclast formation and bone resorption through the suppression of receptor activator of NF-κB ligand (RANKL)-induced NF-κB and nuclear factor of activated T-cell activity and ERK phosphorylation. Furthermore, cumambrin A inhibits the expression of osteoclast marker genes including cathepsin K, calcitonin receptor, and V-ATPase d2. Using an in vivo ovariectomized mouse model, we showed that cumambrin A protects against estrogen withdrawal-induced bone loss. Collectively, our results reveal that cumambrin A can suppress osteoclast formation, bone resorption, and RANKL-induced signaling pathways, suggesting that cumambrin A is a potential therapeutic agent for the treatment of osteoporosis.-Zhou, L., Liu, Q., Hong, G., Song, F., Zhao, J., Yuan, J., Xu, J., Tan, R. X., Tickner, J., Gu, Q., Xu, J. Cumambrin A prevents OVX-induced osteoporosis via the inhibition of osteoclastogenesis, bone resorption, and RANKL signaling pathways.

Asiaticoside, a component of Centella asiatica attenuates RANKL-induced osteoclastogenesis via NFATc1 and NF-κB signaling pathways.

Identification of natural compounds that inhibit osteoclastogenesis will facilitate the development of antiresorptive treatment of osteolytic bone diseases. Asiaticoside is a triterpenoid derivative isolated from Centella asiatica, which exhibits varying biological effects like angiogenesis, anti-inflammation, wound healing, and osteogenic differentiation. However, its role in osteoclastogenesis remains unknown. Here, we show that Asiaticoside can suppress RANKL-induced osteoclast formation and bone resorption in a dose-dependent manner. Asiaticoside attenuated the expression of osteoclast marker genes including Ctsk, Atp6v0d2, Nfatc1, Acp5, and Dc-stamp. Furthermore, Asiaticoside inhibited RANKL-mediated NF-κB and NFATc1 activities, and RANKL-induced calcium oscillation. Collectively, this study demonstrates that Asiaticoside inhibited osteoclast formation and function through attenuating RANKL-induced key signaling pathways, which may indicate that Asiaticoside is a potential antiresorptive agent against osteoclast-related osteolytic bone diseases.

T1 ρ and T2 mapping for the determination of articular cartilage denaturalization with osteonecrosis of the femoral head: A prospective controlled trial.

BACKGROUND: In the future, biochemical MRI might provide a valuable noninvasive quantitative analysis of the biochemical composition of cartilage in osteonecrosis of the femoral head (ONFH). PURPOSE: To investigate the diagnostic performance of T1 ρ and T2 mapping in cartilage denaturalization with ONFH and to determine the correlation between T1 ρ and T2 mapping and the Association Research Circulation Osseous (ARCO) stage. STUDY TYPE: Prospective. SUBJECTS: Forty-seven patients with ONFH (stage I to III according to the ARCO criteria) and 24 volunteers (control group) were recruited for the prospective study. SEQUENCE: Conventional MRI, multiple echo recalled gradient echo (MERGE), and T1 ρ and T2 mapping sequences. ASSESSMENT: Pseudocolor images and MERGE images were combined in the AW4.5 workstation. The region of interest (ROI) of the hip cartilage was 4-6 mm². The sagittal T1 ρ and T2 mapping values were calculated by the two first authors. STATISTICAL TESTS: One-way analysis of variance (ANOVA), LSD t-tests, Pearson correlation analysis, and receiver operator characteristic (ROC) curves. The significance level was set at P < 0.05. RESULTS: The T1 ρ and T2 mapping values of the ONFH group were significantly higher than the values of the control group (P = 0.000). Regarding the assessment of the severity of ARCO staging, both T1 ρ (r = 0.66, P = 0.004) and T2 mapping (r = 0.501, P = 0.002) were positively associated with disease severity. The T1 ρ values were positively correlated with the T2 mapping values (r = 0.381, P = 0.000). The areas under the curve (AUC) for the T1 ρ and T2 mapping values were 0.822 and 0.791, respectively. The diagnostic sensitivity and specificity were 72.34% and 70.83% for T1 ρ mapping and 72.34% and 58.33%, respectively, for T2 mapping. DATA CONCLUSION: Both T1 ρ and T2 mapping performed well in diagnosing the cartilage denaturalization in ARCO stage I-III ONFH patients. T1 ρ mapping had a higher diagnostic sensitivity and specificity than T2 mapping. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:760-767.

EGFL7: Master regulator of cancer pathogenesis, angiogenesis and an emerging mediator of bone homeostasis.

Epidermal growth factor-like domain-containing protein 7 (EGFL7), a member of the epidermal growth factor (EGF)-like protein family, is a potent angiogenic factor expressed in many different cell types. EGFL7 plays a vital role in controlling vascular angiogenesis during embryogenesis, organogenesis, and maintaining skeletal homeostasis. It regulates cellular functions by mediating the main signaling pathways (Notch, integrin) and EGF receptor cascades. Accumulating evidence suggests that Egfl7 plays a crucial role in cancer biology by modulating tumor angiogenesis, metastasis, and invasion. Dysregulation of Egfl7 has been frequently found in several types of cancers, such as malignant glioma, colorectal carcinoma, oral and oesophageal cancers, gastric cancer, hepatocellular carcinoma, pancreatic cancer, breast cancer, lung cancer, osteosarcoma, and acute myeloid leukemia. In addition, altered expression of miR-126, a microRNA associated with Egfl7, was found to play an important role in oncogenesis. More recently, our study has shown that EGFL7 is expressed in both the osteoclast and osteoblast lineages and promotes endothelial cell activities via extracellular signal-regulated kinase (ERK), signal transducer and activator of transcription 3 (STAT3), and integrin signaling cascades, indicative of its angiogenic regulation in the bone microenvironment. Thus, understanding the role of EGFL7 may provide novel insights into the development of improved diagnostics and therapeutic treatment for cancers and skeletal pathological disorders, such as ischemic osteonecrosis and bone fracture healing.

Association of reduced sclerostin expression with collapse process in patients with osteonecrosis of the femoral head.

PURPOSE: Sclerostin is an osteocyte-derived protein that has a potent inhibitory effect on osteoblast activity. The osteocyte apoptosis induced by various causes of osteonecrosis of the femoral head (ONFH) plays a key role in the promotion of femoral head collapse. But the effect of altering sclerostin level on the collapse of ONFH has not been studied. Our aim was to assess the role of sclerostin level in the collapse of ONFH. METHODS: Between May 2016 and November 2016, 236 subjects were enrolled in the present study. The patients were classified according to the Association Research Circulation Osseous (ARCO) classification. The clinical bone histomorphology, the expression position, and level of sclerostin as well as the plasma sclerostin level were evaluated. RESULTS: The sclerostin level was significantly lower in the non-traumatic ONFH group than those in the healthy control group (P = 0.002). The sclerostin level was negatively associated with ARCO stages (r = - 0.239, P = 0.009) and significantly lower in the postcollapse group (P = 0.025). CONCLUSIONS: The reduced expression of sclerostin may play a key role in the collapse process of ONFH and be predictive of the disease progression of ONFH.

The Emerging Role of MORC Family Proteins in Cancer Development and Bone Homeostasis.

Microrchidia (MORC or MORC family CW-type zinc finger protein), a highly conserved nuclear protein superfamily, is an interesting new player in signaling-dependent chromatin remodeling and epigenetic regulation. MORC family proteins consist of MORC1, MORC2, MORC3, and MORC4 which display common structural determinants such as CW-type zinc finger and coiled-coil domains. They also exhibit unique structural motifs and tissue-specific expression profiles. MORC1 was first discovered as a key regulator for male meiosis and spermatogenesis. Accumulating biochemical and functional analyses unveil MORC proteins as key regulators for cancer development. More recently, using an ENU mutagenesis mouse model, MORC3 was found to play a role in regulating bone and calcium homeostasis. Here we discuss recent research progress on the emerging role of MORC proteins in cancer development and bone metabolism. Unravelling the cellular and molecular mechanisms by which MORC proteins carry out their functions in a tissue specific manner are important subjects for future investigation. J. Cell. Physiol. 232: 928-934, 2017. © 2016 Wiley Periodicals, Inc.

Bajijiasu Abrogates Osteoclast Differentiation via the Suppression of RANKL Signaling Pathways through NF-κB and NFAT.

Pathological osteolysis is commonly associated with osteoporosis, bone tumors, osteonecrosis, and chronic inflammation. It involves excessive resorption of bone matrix by activated osteoclasts. Suppressing receptor activator of NF-κB ligand (RANKL) signaling pathways has been proposed to be a good target for inhibiting osteoclast differentiation and bone resorption. Bajijiasu-a natural compound derived from Morinda officinalis F. C. How-has previously been shown to have anti-oxidative stress property; however, its effect and molecular mechanism of action on osteoclastogenesis and bone resorption remains unclear. In the present study, we found that Bajijiasu dose-dependently inhibited RANKL-induced osteoclast formation and bone resorption from 0.1 mM, and reached half maximal inhibitory effects (IC50) at 0.4 mM without toxicity. Expression of RANKL-induced osteoclast specific marker genes including cathepsin K (Ctsk), nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), tartrate resistant acid phosphatase (TRAcP), vacuolar-type H⁺-ATPase V0 subunit D2 (V-ATPase d2), and (matrix metalloproteinase-2 (MMP2) was inhibited by Bajijiasu treatment. Luciferase reporter gene studies showed that Bajijiasu could significantly reduce the expression and transcriptional activity of NFAT as well as RANKL-induced NF-κB activation in a dose-dependent manner. Further, Bajijiasu was found to decrease the RANKL-induced phosphorylation of extracellular signal-regulated kinases (ERK), inhibitor of κB-α (IκB-α), NFAT, and V-ATPase d2. Taken together, this study revealed Bajijiasu could attenuate osteoclast formation and bone resorption by mediating RANKL signaling pathways, indicative of a potential effect of Bajijiasu on osteolytic bone diseases.

Therapeutic potential of a prominent dihydroxyflavanone pinocembrin for osteolytic bone disease: In vitro and in vivo evidence.

Background/objective: As the pivotal cellular mediators of bone resorption and pathological bone remodeling, osteoclasts have emerged as a prominent target for anti-resorptive interventions. Pinocembrin (PIN), a predominant flavonoid found in damiana, honey, fingerroot, and propolis, has been recognized for its potential therapeutic effects in osteolysis. The purpose of our project is to investigate the potential of PIN to prevent bone resorption in ovariectomized (OVX) mice by suppressing osteoclast production through its underlying mechanisms. Methods: The study commenced by employing protein-ligand molecular docking to ascertain the specific interaction between PIN and nuclear factor-κB (NF-κB) ligand (RANKL). Subsequently, PIN was introduced to bone marrow macrophages (BMMs) under the stimulation of RANKL. The impact of PIN on osteoclastic activity was assessed through the utilization of a positive TRAcP staining kit and a hydroxyapatite resorption assay. Furthermore, the study investigated the generation of reactive oxygen species (ROS) in osteoclasts induced by RANKL using H2DCFDA. To delve deeper into the underlying mechanisms, molecular cascades triggered by RANKL, including NF-κB, ROS, calcium oscillations, and NFATc1-mediated signaling pathways, were explored using Luciferase gene report, western blot analysis, and quantitative real-time polymerase chain reaction. Moreover, an estrogen-deficient osteoporosis murine model was established to evaluate the therapeutic effects of PIN in vivo. Results: In this study, we elucidated the profound inhibitory effects of PIN on osteoclastogenesis and bone resorption, achieved through repression of NF-κB and NFATc1-mediated signaling pathways. Notably, PIN also exhibited potent anti-oxidative properties by mitigating RANKL-induced ROS generation and augmenting activities of ROS-scavenging enzymes, ultimately leading to a reduction in intracellular ROS levels. Moreover, PIN effectively abrogated the expression of osteoclast-specific marker genes (Acp5, Cathepsin K, Atp6v0d2, Nfatc1, c-fos, and Mmp9), further underscoring its inhibitory impact on osteoclast differentiation and function. Additionally, employing an in vivo mouse model, we demonstrated that PIN effectively prevented osteoclast-induced bone loss resultant from estrogen deficiency. Conclusion: Our findings highlight the potent inhibitory effects of PIN on osteoclastogenesis, bone resorption, and RANKL-induced signaling pathways, thereby establishing PIN as a promising therapeutic candidate for the prevention and management of osteolytic bone diseases. The translational potential of this article: PIN serves as a promising therapeutic agent for the prevention and management of osteolytic bone diseases and holds promise for future clinical applications in addressing conditions characterized by excessive bone resorption. PIN is a natural compound found in various sources, including damiana, honey, fingerroot, and propolis. Its widespread availability and potential for therapeutic use make it an attractive candidate for further investigation and development as a clinical intervention.

A novel Glycyrrhiza glabra extract liquiritin targeting NFATc1 activity and ROS levels to counteract ovariectomy-induced osteoporosis and bone loss in murine model.

Osteoporosis, a prevalent osteolytic condition worldwide, necessitates effective strategies to inhibit excessive bone resorption by curbing osteoclast hyperactivation. Liquiritin (LIQ), an flavanone derivative employed in acute lung injury and rheumatoid arthritis treatment, possesses an unclear role in addressing excessive bone resorption. In this investigation, we found that LIQ demonstrates the ability to inhibit osteoclast formation and the bone-resorbing activity induced by RANKL. At a specific concentration, LIQ significantly attenuated NF-κB-Luc activity induced by RANKL and curtailed NF-κB activation in RANKL-stimulated RAW264.7 cells, resulting in reduced IκB-α breakdown and diminished nuclear NF-κB levels. Furthermore, LIQ markedly inhibited RANKL-induced NFATc1 activation, as evidenced by diminished NFATc1 luciferase activity, reduced NFATc1 mRNA levels, and decreased nuclear NFATc1 protein levels. Subsequent experiments demonstrated that LIQ effectively restrained the RANKL-induced elevation of intracellular calcium as well as reactive oxygen species. Additionally, LIQ exhibited a downregulating effect on the expression of osteoclast-specific genes, which include Acp5, Cathepsin K, Atp6v0d2, Nfatc1, c-Fos, and Mmp9. Notably, our findings revealed the potential of LIQ to counteract decreased bone density in mice that underwent ovariectomy. Collectively, the data indicate that LIQ impedes osteoclast formation triggered by RANKL and the subsequent reduction in bone mass by mitigating ROS levels and suppressing the Ca2+/MAPK-NFATc1 signaling pathway, suggesting its promising candidacy as a therapeutic agent for RANKL-mediated osteoporosis.

Predicting Collapse in Osteonecrosis of the Femoral Head Using a New Method: Preserved Angles of Anterior and Lateral Femoral Head.

BACKGROUND: Femoral head collapse (FHC) is associated with a poor prognosis in osteonecrosis of the femoral head (ONFH). Preserved angles (PAs), including the lateral preserved angle (LPA), the anterior preserved angle (APA) and the combined preserved angle (CPA), can be used to quantify the extent of femoral head necrosis and predict the risk of femoral head collapse. The purpose of this retrospective cohort study was to assess the efficacy of these preserved angles in the prediction of femoral head collapse using plain radiographs. METHODS: Patients with ONFH treated conservatively between January 2010 and January 2019 were analyzed retrospectively to assess the risk of FHC. A logistic regression model was used to evaluate the independent prognostic factors associated with FHC, including age, sex, etiology, onset of symptom, The Japanese Investigation Committee classification, and PAs (LPA, APA, and CPA). RESULTS: A total of 137 patients, with 180 hips, had follow-up of at least two years and were included. During the follow-up period, FHC occurred in 89 hips (49.44%) after the initial diagnosis. Multivariable analysis indicated that CPA (odds ratio [OR] = 0.95; 95%CI = 0.93-0.97; P < 0.01) was a stronger predictor of femoral head collapse compared with the Japanese Investigation Committee classification (OR = 2.40, 95%CI = 0.92-6.25; P > 0.01). The receiver operating characteristic and survival curve analyses revealed that the predictive cutoff point for the CPA was 118.7° (sensitivity = 96.70%, specificity = 79.78%, log-rank test: P < 0.01). CONCLUSIONS: Assessment of preserved angles on plain radiographs is a simple method to quantify the extent of lateral and anterior necrosis of the femoral head. Specifically, CPA has a potential value in predicting femoral head collapse.

Novel MRI technique for the quantification of biochemical deterioration in steroid-induced osteonecrosis of femoral head: a prospective diagnostic trial.

To explore the novel magnetic resonance imaging techniques, IVIM-DWI and IDEAL-IQ in detecting bone marrow fat and microcirculation in steroid-induced osteonecrosis of the femoral head (SIONFH). In this prospective study, 49 patients (80 hips) with SIONFH taking glucocorticoids and 24 healthy volunteers (48 hips) were recruited and assessed by T1WI, T2WI/fs, IDEAL-IQ and IVIM-DWI. The affected hips, contralateral asymptomatic hips and normal hips, as well as normal, penumbra and necrotic areas in the affected hips, were classified and evaluated. Imaging results were compared with histologic bone sections obtained from SIONFH patients undergoing surgery. The fat fraction (FF) and perfusion fraction (f) differences between groups were analyzed using analysis of variance, the LSD t-test, Pearson correlation analysis and ROC curve analysis. Our results demonstrate that IDEAL-IQ (FF) and IVIM-DWI (f) enable the classification of SIONFH at different ARCO stages. The FF was positively associated with the progression of the disease (r = 0.72), in contrast to f (r = -0.17). The FF and f were significantly different among the necrotic, penumbra and normal areas, and they were negatively correlated with each other (r = -0.37). The diagnostic sensitivity and specificity of IDEAL-IQ were 96.9% and 86.7%, and those of IVIM-DWI were 72.34% and 58.33%, respectively. The FF in contralateral asymptomatic hips was significantly higher than in normal hips, but no difference was found for f. IDEAL-IQ, and not IVIM-DWI, was identified to successfully detect bone marrow fat, which is beneficial to the diagnosis of the severity of SIONFH.

The association the patient-reported outcomes after periacetabular osteotomy with radiographic features: a short-term retrospective study.

BACKGROUND: Bernese periacetabular osteotomy (PAO) is an effective treatment for patients with developmental dysplasia of the hip (DDH). PAO has been widely used in China, but few follow-up outcomes have been reported in the international community. Moreover, the risk factors affecting patient-reported outcomes have not been discussed in recent studies. In this study, patient-reported outcomes after PAO were reported, and risk factors affecting patient-reported outcomes were analyzed. METHODS: Patients who underwent PAO for DDH from January 2014 to January 2020 were selected as the study subjects, and 66 hips were included in the analysis after screening (59 patients, with an average follow-up time of 3.01 years). The Harris Hip Score (HHS) and International Hip Outcome Instrument-12 (iHOT-12) were used to assess hip function and patient quality of life. The changes of preoperative and latest follow-up HHSs less than 9 were defined as symptomatic hips, that is, an adverse outcome; otherwise, the score indicates preserved hips. Also, the changes of preoperative and latest follow-up iHOT-12 were defined as symptomatic hips and preserved hips. Multivariate logistic regression analysis was used to predict the risk factors influencing the patient-reported outcomes, and receiver operating characteristic (ROC) curve analysis was performed on the risk factors to determine their sensitivity, specificity and cutoff value. RESULTS: Clinical outcome analysis demonstrates marked improvements in patient-reported outcomes. The multivariate logistic regression analysis showed that when the postoperative LCEA was > 38°, adverse outcomes were much more likely. However, a Tönnis angle of - 10° to 0° was a protective factor. In addition, hips with fair or poor joint congruency were more likely to develop negative outcomes. The ROC curve analysis showed that the optimal thresholds for the LCEA and Tönnis angles used to predict outcomes after PAO were 38.2° and - 9°, respectively. Based on the results of the ROC curve analysis, among hips with poor or fair joint congruency preoperatively treated by surgeons who obtained the improper postoperative LCEAs and Tönnis angles, bad patient-reported outcomes will most likely be obtained. CONCLUSIONS: Our results demonstrate marked improvements in patient-reported outcomes. Among hips with preoperative excellent or good joint congruency treated by experienced surgeons who obtain the proper postoperative LCEA and Tönnis angles, good patient-reported outcomes can be expected.

A novel RANKL-targeted flavonoid glycoside prevents osteoporosis through inhibiting NFATc1 and reactive oxygen species.

BACKGROUND AND PURPOSE: Osteoporosis is characterized by excessive bone resorption due to enhanced osteoclast activation. Stimulation of nuclear factor of activated T cells 1 (NFATc1) and accumulation of reactive oxygen species (ROS) are important mechanisms underlying osteoclastogenesis. Robinin (Rob) is a flavonoid glycoside that has shown anti-inflammatory and antioxidative effects in previous studies, but little is known about its effects on bone homeostasis. The purpose of our research was to investigate whether Rob could prevent bone resorption in ovariectomized (OVX) mice by suppressing osteoclast production through its underlying mechanisms. METHODS: The docking pose of Rob and RANKL was identified by protein-ligand molecular docking. Rob was added to bone marrow macrophages (BMMs) stimulated by nuclear factor-κB (NF-κB) ligand (RANKL). The effects of Rob on osteoclastic activity were evaluated by positive tartrate resistant acid phosphatase (TRAcP) staining kit and hydroxyapatite resorption assay. RANKL-induced ROS generation in osteoclasts was detected by H2 DCFDA and MitoSox Red staining. The classic molecular cascades triggered by RANKL, such as NF-κB, ROS, calcium oscillations, and NFATc1-mediated signaling pathways, were investigated using Fluo4 staining, western blot, and quantitative real-time polymerase chain reaction. In addition, an OVX mouse model mimicking estrogen-deficient osteoporosis was created to evaluate the therapeutic effects of Rob in vivo. RESULTS: Computational docking results showed that Rob could bind specifically to RANKL's predicted binding sites. In vitro, Rob inhibited RANKL-mediated osteoclastogenesis dose-dependently without obvious cytotoxicity at low concentrations. We also found that Rob attenuated RANKL-induced mitochondrial ROS production or enhanced activities of ROS-scavenging enzymes, and ultimately reduced intracellular ROS levels. Rob abrogated the RANKL-induced mitogen-activated protein kinase (MAPK) and NF-κB signaling pathways, and subsequently blocked NFATc1 signaling and TRAcP expression. In addition, Rob inhibited osteoclast proliferation by downregulating the expression of osteoclast target genes (Acp5, Cathepsin K, Atp6v0d2, Nfact1, c-Fos, and Mmp9) and reducing Ca2+ oscillations. Our in vivo results showed that Rob reduced bone resorption in OVX animal model by repressing osteoclast activity and function. CONCLUSIONS: Rob inhibits the activation of osteoclasts by targeting RANKL and is therefore a potential osteoporosis drug.

[Short- and mid-term effectiveness of impaction bone allograft with acetabular components in treatment of severe acetabular defects].

OBJECTIVE: To investigate the short- and mid-term effectiveness of revision hip arthroplasty by using impaction bone allograft and acetabular components in treatment of severe acetabular defects. METHODS: A clinical data of 42 patients (44 hips) with severe acetabular defects between February 2011 and May 2018 were retrospectively analyzed. All patients underwent revision hip arthroplasty by using impaction bone allograft and acetabular components. Cemented cup (24 cases, 24 hips) and non-cemented cup (18 cases, 20 hips) were used in the revision surgery. There were 17 males and 25 females with an average age of 62.8 years (range, 22-84 years). The interval between the first total hip arthroplasty and revision was 2.5-12.0 years (mean, 8.3 years). The patients were accepted revision surgery for prosthesis aseptic loosening in 32 hips (31 cases) and the periprosthetic infection in 12 hips (11 cases). Twenty-nine hips (28 cases) were Paprosky type ⅢA and 15 hips (14 cases) were type ⅢB. The preoperative Harris score was 22.25±10.31 and the height of hip rotation center was (3.67±0.63) cm and the length difference of lower limbs was (3.41±0.64) cm. RESULTS: The operation time was 130-245 minutes (mean, 186 minutes) and the intraoperative blood loss was 600-2 400 mL (mean, 840 mL). The postoperative drainage volume was 250-1 450 mL (mean, 556 mL). Superficial infection of the incision occurred in 1 case, and the incisions healed by first intention in the other patients. All patients were followed up 6-87 months, with an average of 48.6 months. At last follow-up, the Harris score was 85.85±9.31, which was significantly different from the preoperative score ( t=18.563, P=0.000). Imaging examination revealed that the allogeneic bone gradually fused with the host bone, and no obvious bone resorption was observed. At last follow-up, the height of the hip rotation center was (1.01±0.21) cm, which was significantly different from the preoperative level ( t=17.549, P=0.000); the length difference of lower limbs was (0.62±0.51) cm, which was significantly different from the preoperative level ( t=14.211, P=0.000). The Harris score in the cemented group and non-cemented group increased significantly at last follow-up. The height of the hip rotation center decreased, and the hip rotation centers of both groups were within the Ranawat triangle zone. The length difference of the lower limbs also decreased, and the differences in all indexes were significant between pre- and post-operation ( P<0.05). There was significant difference in the height of the hip rotation center between groups ( t=2.095, P=0.042), but there was no significant difference in the Harris score and the length difference of lower limbs between groups ( P>0.05). CONCLUSION: For severe acetabular defect (Paprosky type Ⅲ), the hip can be reconstructed with the impaction bone allograft and cemented or non-cemented components in revision hip arthroplsty. The short- and mid-term effectiveness are satisfactory.

Optimizing indications of impacting bone allograft transplantation in osteonecrosis of the femoral head.

AIMS: The aim of this study was to report the medium-term outcomes of impaction bone allograft and fibular grafting for osteonecrosis of the femoral head (ONFH) and to define the optimal indications. METHODS: A total of 67 patients (77 hips) with ONFH were enrolled in a single centre retrospective review. Success of the procedure was assessed using the Harris Hip Score (HHS) and rate of revision to total hip arthroplasty (THA). Risk factors were studied, including age, aetiology, duration of hip pain, as well as two classification systems (Association Research Circulation Osseous (ARCO) and Japanese Investigation Committee (JIC) systems). RESULTS: After a mean follow-up period of 8.61 years (SD 1.45), 81.3% (52/64) of enrolled cases had a good or excellent HHS at latest follow-up (declining to 76.0% (38/50) for those with more than eight years of follow-up). Overall survival was 92.1% at eight years' follow-up (95% CI 83.2% to 96.4%). A total of 12 hips (19.0%) failed (reoperation or HHS < 70 points) at final follow-up. Rate of success was adversely affected by increasing age, duration of pain, and more severe disease as measured using the ARCO and JIC classifications, but not by aetiology of the ONFH. CONCLUSION: We report favourable medium-term results of this procedure. Best outcomes can be expected in patients matching the following indications: younger than 40 years; less 12-month hip pain before surgery; femoral head collapse being less than 2 mm; and integrated lateral wall of femoral head. Cite this article: Bone Joint J 2020;102-B(7):838-844.

The survival of non-traumatic osteonecrosis of femoral head at ARCO II with ring-shaped sclerotic zone: a mid-term follow-up retrospective study.

The sclerotic zone in the osteonecrosis of femoral head (ONFH), containing condensed trabecular bone and abundant neovascularization, is the transition area between osteonecrosis and normal tissue. Due to the prominent feature in ONFH, the characteristics of the sclerotic zone might indicate the femoral head survival of the disease. Thirty ONFH patients (41 hips) with ring-shaped sclerotic zone at Association Research Circulation Osseous-II were recruited during 1996 to 2019, and the corresponding radiographic images in their follow-up are reviewed retrospectively. Two subtypes (type A and B) are defined to discriminate different locations of ring-shaped sclerotic zone in the femoral head (center or subchondral bone plate) in accordance with the radiographic images. The natural history of the enrolled subjects was followed up for average 9 years to record and compare their collapse incidences as well as the progress of hip symptoms. Chi-square test shows that the occurrence rates of symptomatic hip of type A are significantly lower than that of type B and differences between these two groups were significant (P < 0.05). Kaplan Meier survival curve analysis shows that the mean survival time of type A is 247.600 M (95% CI: 203.072 ∼ 292.128 M) and type B is 88.795 M (95% CI: 72.607 ∼ 104.984 M). The survival rate of femoral head of type A is significantly higher than that of type B (P < 0.005). This study demonstrates that type A shows a more satisfactory clinical outcomes and lower femoral head collapse rate in a mid-term follow-up.

Asiatic Acid Inhibits OVX-Induced Osteoporosis and Osteoclastogenesis Via Regulating RANKL-Mediated NF-κb and Nfatc1 Signaling Pathways.

Asiatic acid is a triterpenoid compound extracted from a medicinal plant Centella asiatica. It has been used as a highly efficient compound for the treatment of cancer and hyperlipidemia, as well as possessing potential antiinflammatory properties. However, its effects on bone metabolism and osteoporosis haven't been reported. The purpose of our research were to reveal the biomolecular effects of asiatic acid on osteoclasts, and its underlying molecular mechanisms regulating its effects on receptor activator of NF-κB ligand (RANKL)-induced signaling pathways. We found that asiatic acid inhibited multinucleated tartrate-resistant acid phosphatase (TRAcP)-positive osteoclast differentiation and osteoclast induced bone loss. Real time PCR showed that asiatic acid reduced the expression of down-cascade target genes including Ctsk, Nfatc1, Calcr, and Atp6v0d2. Western blot and luciferase reporter gene assays revealed that asiatic acid inhibits RANKL mediated NF-κB and NFATc1 signalings. Further, in vivo study demonstrated asiatic acid attenuates estrogen deficiency-induced bone loss in ovariectomized mice. MicroCT and histology analyses revealed that osteoclast numbers were significantly suppressed in asiatic acid treated groups. Furthermore, serum levels of TRAcP and CTX-1 were downregulated in treated groups. Taken together, our data show that asiatic acid can inhibit osteoclastic formation and reduce OVX-induced bone resorption through RANKL-activated NF-κB or NFATc1 signaling, suggesting that asiatic acid may be a potential and effective natural compound for the therapy of excessive RANKL-related osteolytic diseases.

Fangchinoline protects against bone loss in OVX mice via inhibiting osteoclast formation, bone resorption and RANKL-induced signaling.

Osteoporosis is a disease characterized by abnormally increased formation and function of osteoclasts. Anti-RANKL treatment using natural medicine is a potential therapy for osteoporosis. Here, we studied the effect of fangchinoline, which is extracted from the root of Stephania tetrandra S. Moore, on osteoclast formation and function. We found that fangchinoline inhibited osteoclastogenesis at doses of 0.5 and 1 µM. In addition, we also examined the mechanism of the inhibitory effect of fangchinoline on osteoclasts. We found that fangchinoline down regulated NFATc1 activity and expression. However, fangchinoline did not affect IκBα degradation and MAPK pathways. In addition, we also found that fangchinoline could protect against bone loss in OVX mice. Taken together, fangchinoline may be a potential compound for osteoporosis.