Prevent Bone Loss Research Articles

Bone mineral density of the rat tibia under modeling of glucocorticoid-induced osteoporosis and the influence of whole body vibration: experimental stud

The aim – investigate the effect of whole-body vibration with high-frequency on the mineral density of the tibia of rats treated with glucocorticoids.Material and methods. 54 adult male Wistar rats were randomized to three groups: control, experimental group I - rats treated with methylprednisolone and experimental group II - methylprednisolone with whole-body vibration. Rats of the two experimental groups received methylprednisolone at a dose of 3 mg/kg every other day for 24 weeks. Group II was subjected to a total vertical vibration (50 Hz, with a vibration acceleration of 0.3g) for 30 min per day, 5 days per week throughout the experiment. Mineral density was assessed by CT densitometry at 8-16-24 weeks of the study.Results. The most significant bone loss was observed in experimental group I at the 16th and 24th week of the experiment, which decreased by 18.6% and 20.8%, respectively, compared with the control group. In experimental group II, the bone density index did not statistically decrease at the 8th week of our study, but at the 16th week decreased by -16.3%; and on the 24th week by -23.5% according to the control group. The density of the cortical layer of bone tissue did not change statistically in the experimental groups in relation to the control group.Conclusions. Our study demonstrated that high-frequency mechanical oscillations could partially suppress the harmful effects of methylprednisolone on bone mineral density in rats. Because glucocorticoids are an important cause of secondary osteoporosis in humans, mechanical stimulation in the form of exercise and training can prevent bone loss and stimulate bone formation.

Andrographolide prevents bone loss via targeting estrogen-related receptor-α-regulated metabolic adaption of osteoclastogenesis.

Metabolic adaptation driven by oestrogen-related receptor-α (ERRα/NR3B1) is required to meet the increased energy demand during osteoclast differentiation. Here, we hypothesize that natural product, andrographolide, acts as an ERRα inverse agonist to inhibit osteoclastogenesis. Virtual docking and site-directed mutagenesis analysis were employed to study the binding mode of andrographolide to ERRα. Co-immunoprecipitation, luciferase reporter assay, real-time polymerase chain reaction (PCR) and immunoblot analyses were performed to identify andrographolide as an ERRα inverse agonist. The pharmacological effects of andrographolide in vivo were assessed in mice models of osteopenia induced by either a high-fat diet in male or ovariectomy in female mice. ERRα-dependent expression of glutaminase, a rate-limiting enzyme of mitochondrial glutamine anaplerosis, is required for ex vivo bone marrow osteoclast differentiation. Andrographolide inhibited glutaminase expression induced by ERRα and co-activator peroxisome proliferator-activated receptor γ co-activator-1β (PGC-1β), leading to reduction in osteoclastogenesis. Andrographolide acted as an inverse agonist of ERRα by disrupting its interaction with co-activator PGC-1β. Phenylalanine 232, valine 395 and phenylalanine 399 of ERRα ligand-binding domain were confirmed to be essential for this effect. In contrast, glutaminase overexpression restored the impairment triggered by andrographolide. Accordingly, andrographolide suppressed osteoclastic bone resorption and attenuated bone loss in vivo. These findings demonstrate that andrographolide acts as an ERRα inverse agonist for perturbation of ERRα/PGC-1β/glutaminase axis-driven metabolic adaption during osteoclast differentiation, implying that andrographolide may be a promising natural compound for preventing physiological and pathological bone loss.

Effectiveness of bisphosphonates on bone mineral density in osteopenic postmenopausal women: A systematic review and network meta-analysis of randomized controlled trials.

Background:Various bisphosphonate agents have been proven to be effective in preventing bone loss and fracture in osteopenic postmenopausal women. This study was designed to compare the effectiveness of various BPs on preventing the loss of bone mineral density (BMD) for postmenopausal women with osteopenia.Methods:PubMed, EMBASE, and Cochrane Central Register of Controlled Trials were screened up to identify randomized controlled trails comparing effectiveness of BPs or placebo on the BMD of postmenopausal women with osteopenia. Network meta-analysis and standard pair-wise meta-analyses were performed. The main outcomes include the percentage changes of 6-, 12-, 24-, and 36-month BMD at lumbar, total hip and femoral neck, and frequencies of new fractures and severe adverse events.Results:Fourteen randomized controlled trials were eligible, involving 11,540 participants. No significant difference was presented among the available interventions for the 6-month BMD at 3 different sites, but the magnitudes of differences among the treatment regimens became gradually increased along with the extending of follow-up periods. Daily aledronate of more than 5 mg provided the maximal percentage increase on BMD of femoral neck and lumbar spine, while zoledronate provided maximal change on BMD of total hip, at different follow-up periods. This network meta-analysis also demonstrated similar frequencies of new clinical fractures and severe adverse events among different interventions.Conclusions:A ranking spectrum depicting the effectiveness on BMD percentage change following interventions with different bisphosphonate regimens was provided. Generally, regimens with zoledronate and aledronate were found to be the most effective interventions in the 3 sites at different end points.

Genome-scale insights into the metabolic versatility of Limosilactobacillus reuteri

BackgroundLimosilactobacillus reuteri (earlier known as Lactobacillus reuteri) is a well-studied lactic acid bacterium, with some specific strains used as probiotics, that exists in different hosts such as human, pig, goat, mouse and rat, with multiple body sites such as the gastrointestinal tract, breast milk and mouth. Numerous studies have confirmed the beneficial effects of orally administered specific L. reuteri strains, such as preventing bone loss and promoting regulatory immune system development. L. reuteri ATCC PTA 6475 is a widely used strain that has been applied in the market as a probiotic due to its positive effects on the human host. Its health benefits may be due, in part, to the production of beneficial metabolites. Considering the strain-specific effects and genetic diversity of L. reuteri strains, we were interested to study the metabolic versatility of these strains.ResultsIn this study, we aimed to systematically investigate the metabolic features and diversities of L. reuteri strains by using genome-scale metabolic models (GEMs). The GEM of L. reuteri ATCC PTA 6475 was reconstructed with a template-based method and curated manually. The final GEM iHL622 of L. reuteri ATCC PTA 6475 contains 894 reactions and 726 metabolites linked to 622 metabolic genes, which can be used to simulate growth and amino acids utilization. Furthermore, we built GEMs for the other 35 L. reuteri strains from three types of hosts. The comparison of the L. reuteri GEMs identified potential metabolic products linked to the adaptation to the host.ConclusionsThe GEM of L. reuteri ATCC PTA 6475 can be used to simulate metabolic capabilities and growth. The core and pan model of 35 L. reuteri strains shows metabolic capacity differences both between and within the host groups. The GEMs provide a reliable basis to investigate the metabolism of L. reuteri in detail and their potential benefits on the host.

Phytocystatin CsinCPI-2 Reduces Osteoclastogenesis and Alveolar Bone Loss

Periodontal disease (PD) is a polymicrobial chronic inflammatory condition of the supporting tissues around the teeth, leading to the destruction of surrounding connective tissue. During the progression of PD, osteoclasts play a crucial role in the resorption of alveolar bone that eventually leads to the loss of teeth if the PD is left untreated. Therefore, the development of antiresorptive therapies targeting bone-resorbing cells will significantly benefit the treatment of PD. Here, we demonstrate the inhibitory effect of CsinCPI-2, a novel cysteine peptidase inhibitor from the orange tree, on periodontitis-induced inflammation, alveolar bone loss, and osteoclast differentiation. Using the ligature-induced periodontitis model in mice, we show that treatment with CsinCPI-2 (0.8 µg/g of body weight) significantly reduced inflammatory cell infiltrate in the connective tissue and prevented the loss of alveolar bone mass (BV/TV) caused by PD, effects associated with diminished numbers of TRAP-positive multinucleated cells. Furthermore, CsinCPI-2 significantly downregulated the numbers of inflammatory cells expressing CD3, CD45, MAC387, and IL-1β. In vitro, CsinCPI-2 inhibited RANKL-induced TRAP+ multinucleated osteoclast formation in mouse bone marrow macrophage cultures in a concentration-dependent manner. This effect was not due to cytotoxicity, as demonstrated by the MTT assay. CsinCPI-2 inhibited RANKL-induced mRNA expression of Acp5, Calcr, and Ctsk, as well as the RANKL-induced upregulation of Nfatc1, a crucial transcription factor for osteoclast differentiation. Based on our findings, CsinCPI-2 prevents bone loss induced by PD by controlling the inflammatory process and acting directly on osteoclastogenesis, suggesting an interesting potential for CsinCPI-2 in the strategy for PD treatment.

Selective Estrogen Receptor Modulators in Gynecology Practice.

Selective estrogen receptor (ER) modulators have variable tissue specific estrogen agonist and antagonist activities. Tamoxifen is approved for treatment and prevention of breast cancer; acts as an endometrial estrogen agonist. Raloxifene is approved for prevention and treatment of osteoporosis and prevention of breast cancer. The selective ER modulators bazedoxifene paired with conjugated estrogens relieves vasomotor symptoms and prevents bone loss with neutral effects on breast and amenorrhea similar to placebo. Ospemifene is approved to treat dyspareunia. Lasofoxifene is in development for resistant ER positive breast cancer. Estetrol (E4), synthesized by human fetal liver, has dual weak-estrogenic/antiestrogenic features, now approved as a contraceptive.

The Impact of Nordic Walking on Bone Properties in Postmenopausal Women with Pre-Diabetes and Non-Alcohol Fatty Liver Disease

This study investigated the impact of Nordic walking on bone properties in postmenopausal women with pre-diabetes and non-alcohol fatty liver disease (NAFLD). A total of 63 eligible women randomly participated in the Nordic walking training (AEx, n = 33), or maintained their daily lifestyle (Con, n = 30) during intervention. Bone mineral content (BMC) and density (BMD) of whole body (WB), total femur (TF), femoral neck (FN), and lumbar spine (L2-4) were assessed by dual-energy X-ray absorptiometry. Serum osteocalcin, pentosidine, receptor activator of nuclear factor kappa-B ligand (RANKL) levels were analyzed by ELISA assay. After an 8.6-month intervention, the AEx group maintained their BMCTF, BMDTF, BMCL2−4, and BMDL2−4, and increased their BMCFN (p = 0.016), while the Con group decreased their BMCTF (p = 0.008), BMDTF (p = 0.001), and BMDL2−4 (p = 0.002). However, no significant group × time interaction was observed, except for BMDL2−4 (p = 0.013). Decreased pentosidine was correlated with increased BMCWB(r = −0.352, p = 0.019). The intervention has no significant effect on osteocalcin and RANKL. Changing of bone mass was associated with changing of pentosidine, but not with osteocalcin and RANKL. Our results suggest that Nordic walking is effective in preventing bone loss among postmenopausal women with pre-diabetes and NAFLD.

Liquiritigenin promotes osteogenic differentiation and prevents bone loss via inducing auto-lysosomal degradation and inhibiting apoptosis

Osteoporosis (OP) is a debilitating skeletal abnormality involving bone remodeling and bone cell homeostasis characterized by decreased bone strength and high fracture risk. A novel therapeutic intervention for OP by manipulating cellular autophagy–apoptosis processes to promote skeletal homeostasis is presented. Protective effects of the naturally occurring plant extract Liquiritigenin (LG) were demonstrated in an ovariectomy (OVX)-OP mouse model and preosteoblast MC3T3-E1 cells. Micro-CT and histological staining assessments of skeletal phenotype were applied alongside detection of autophagy activity in osteocytes and MC3T3-E1 cells by transmission electron microscopy (TEM). The effects of LG on chloroquine (CQ)- and the apoptosis-inducing TS-treated osteogenic differentiations and status of lysosomes within MC3T3-E1 cells were analyzed by Neutral red, Alizarin red S and alkaline phosphatase (ALP) staining and Western blot assays. Treatment with LG prevented bone loss, increased osteogenic differentiation in vivo and in vitro, and inhibited osteoclast formation to some extent. TEM analyses revealed that LG can improve auto-lysosomal degradation within osteocytes from OVX mice and MC3T3-E1 cells. The abnormal status of lysosomes associated with CQ and TS treatments was notably alleviated by LG which also reduced levels of apoptosis-induced inhibition of osteogenic differentiation and averted abnormal osteogenic differentiation as a consequence of a blockage in autolysosome degradation. Overall, LG stimulates bone growth in OVX mice through increased osteogenic differentiation and regulation of autophagy-apoptosis mechanisms, presenting an auspicious natural therapy for OP.

Effectiveness of bazedoxifene in preventing glucocorticoid-induced bone loss in rheumatoid arthritis patients

ObjectiveTo evaluate the effectiveness of bazedoxifene in preventing bone loss in patients with rheumatoid arthritis (RA) receiving low-dose glucocorticoids (GCs).MethodsIn this randomized, controlled, open-label study, we assigned postmenopausal women with osteopenia who had been receiving low-dose GCs for RA to two groups: a group receiving bazedoxifene (20 mg/day) with elemental calcium 1200 mg and vitamin D 800 IU daily (bazedoxifene group) and a group receiving the same doses of calcium and vitamin D only (control group). As primary outcome, bone mineral density (BMD) change in the lumbar spine (L-spine) from baseline to 48 weeks was assessed. Changes in BMD in the femur, trabecular bone score, bone turnover markers, and development of fracture were assessed as secondary outcomes. For intention-to-treat analysis, 20 completed data sets were created by applying multiple imputations by chained equations.ResultsA total of 114 patients (57 patients in each group) were recruited. A significant increase in L-spine BMD (0.015 g/cm2, P = 0.007) was observed in the bazedoxifene group, and the increase was significantly higher than in the control group (0.013, 95% CI 0.0003–0.026, P = 0.047). Reductions in bone turnover markers in the bazedoxifene group were significantly greater than in the control group. Only one fracture was observed in the bazedoxifene group, while four fractures developed in the control group.ConclusionIn postmenopausal patients with RA receiving low-dose GCs, bazedoxifene improved BMD and reduced bone turnover markers. However, the change in BMD did not exceed the least significant change.Trial registrationClinicalTrials.gov, NCT02602704.

Understanding and Managing Corticosteroid-Induced Osteoporosis.

Glucocorticoids are effective immunosuppressants used in a wide variety of diseases. Their use results in secondary osteoporosis in about 30–50% of chronic glucocorticoid users. Glucocorticoids cause a rapid decline in bone strength within the first 3–6 months mostly due to increased bone resorption by osteoclasts. This is followed by a more gradual loss of bone partly due to decreased osteoblastogenesis and osteoblast and osteocyte apoptosis. The loss of bone strength induced by glucocorticoids is not fully captured by bone mineral density measurements. Other tools such as the trabecular bone score and advanced imaging techniques give insight into bone quality; however, these are not used widely in clinical practice. Glucocorticoid-induced osteoporosis should be seen as a widely preventable disease. Currently, only about 15% of chronic glucocorticoid users are receiving optimal care. Glucocorticoids should be prescribed at the lowest dose and shortest duration. All patients should be counselled on lifestyle measures to maintain bone strength including nutrition and weight-bearing exercise. Pharmacological therapy should be considered for all patients at moderate to high risk of fracture as there is evidence for the prevention of bone loss and fractures with a favourable safety profile. Oral bisphosphonates are the current mainstay of therapy, whereas osteoanabolic agents may be considered for those at highest risk of fracture.

A Hot Flash about Menopause Hormone Therapy

Hormone therapy (HT) for vasomotor and genitourinary symptoms associated with menopause has been an effective treatment for relief of these symptoms and the prevention of bone loss and fracture, but does entail potential risks for which our understanding continually evolves with additional studies. Risks of HT are likely to be minimized if started within 10 years of menopause onset. HT, types of HT, dose, route of application, and duration of use should be individualized taking into account age, personal health risks, time since menopause, and individual preferences and quality of life issues to minimize risks and maximize benefits

Anti-Inflammatory Effects of Low-Dose Glucocorticoids Compensate for Their Detrimental Effects on Bone Mineral Density in Patients with Rheumatoid Arthritis.

Objectives: This study aimed to provide reliable information on the impact of low-dose glucocorticoids (GCs) on the bone mineral density (BMD) of patients with rheumatoid arthritis (RA). Methods: This retrospective study enrolled 933 patients with RA who continued the consumption of GCs (GC group) and 100 patients who had discontinued consumption for >1 year (no-GC group). The BMD values were measured at baseline and follow-up, and the annual rate of change in BMD between the groups was compared using dual-energy X-ray absorptiometry. We used multiple linear regression analysis to identify the factors associated with changes in BMD. Results: The demographic characteristics and use of medical treatments affecting bone metabolism were similar between the two groups. Furthermore, there were no significant differences in the annual rate of changes in BMD and incidence of newly developed osteoporosis and incidental fractures between the two groups. Multiple linear regression analysis revealed that the disease activity score for 28 joints with erythrocyte sedimentation rate was the only factor affecting the annual rate of changes in BMD, and it was inversely proportional to changes in BMD. Conclusion: The benefits of GC therapy in attenuating inflammation compensate for the risk of osteoporosis if adequate measures to prevent bone loss are implemented in patients with RA.

A novel BRD4 inhibitor suppresses osteoclastogenesis and ovariectomized osteoporosis by blocking RANKL-mediated MAPK and NF-\u03baB pathways

Bromodomain-containing protein 4 (BRD4) has emerged as a promising treatment target for bone-related disorders. (+)-JQ1, a thienotriazolodiazepine compound, has been shown to inhibit pro-osteoclastic activity in a BRD4-dependent approach and impede bone loss caused by ovariectomy (OVX) in vivo. However, clinical trials of (+)-JQ1 are limited because of its poor druggability. In this study, we synthesized a new (+)-JQ1 derivative differing in structure and chirality. One such derivative, (+)-ND, exhibited higher solubility and excellent inhibitory activity against BRD4 compared with its analogue (+)-JQ1. Interestingly, (-)-JQ1 and (-)-ND exhibited low anti-proliferative activity and had no significant inhibitory effect on RANKL-induced osteoclastogenesis as compared with (+)-JQ1 and (+)-ND, suggesting the importance of chirality in the biological activity of compounds. Among these compounds, (+)-ND displayed the most prominent inhibitory effect on RANKL-induced osteoclastogenesis. Moreover, (+)-ND could inhibit osteoclast-specific gene expression, F‐actin ring generation, and bone resorption in vitro and prevent bone loss in OVX mice. Collectively, these findings indicated that (+)-ND represses RANKL‐stimulated osteoclastogenesis and averts OVX-triggered osteoporosis by suppressing MAPK and NF-κB signalling cascades, suggesting that it may be a prospective candidate for osteoporosis treatment.

Exosome-Mediated Transfer of lncRUNX2-AS1 from Multiple Myeloma Cells to Mesenchymal Stem Cells Contributes to Osteogenic Differentiation

Purpose: How exosomic lncRNAs contribute to the development of osteogenic differentiation in the context of the bone marrow microenvironment (BMMe) has not been previously described in multiple myeloma (MM). We hypothesized that the BMMe affects osteogenic differentiation of MSCs through exosomic lncRNAs. We aimed to assess which exosomic lncRNAs are involved and through which molecular mechanisms they elicit the hypothesized function.Methods: We isolated exosomes and confirmed their identity using transmission electron microscopy, nanoparticle tracking analysis and western blot. Co-culture experiments were performed to assess exosomic transfer of lncRUNX2-AS1 from MM cells to MSCs. RNase protection assay was used to examine the possibility of RNA duplexformation between lncRUNX2-AS1 and RUNX2. To investigate whether the overlapping RNA duplex affects the stability of the mRNA, we blocked any new mRNA synthesis with α-amanitin treatments. We developed in-vivo mouse models of bone marrow-disseminated human myeloma to evaluate bone activities. Student's t test was employed to assess the differences between treatment groups.Results: lncRNA profile analysis and sequential screening identified highly abundant lncRUNX2-AS1 in MSCs from MM. lncRUNX2-AS1 could be packaged into exosomes and transferred to recipient cells, resulting in the reduction of osteogenic differentiation of MSCs. Furthermore, lncRUNX2-AS1 and RUNX2 formed an RNA duplex and mutually decreased their stability. As a pair of protein-coding cis-sense/non-coding antisense transcripts, RUNX2 and lncRUNX2-AS1 were dysregulated simultaneously and correlated negatively in MSCs, driving osteogenic differentiation of MSCs. Invivo mouse models, intraperitoneally administered GW4869, an inhibitor of exosome secretion, was found to be effective in prevention of bone loss, sustained by both bone-forming and anticatabolic activities.Conclusions: We identified an antisense lncRUNX2-AS1 formed sense-antisense pairs by pairing with a protein-coding gene RUNX2 on the opposite strand to regulate mRNA stability. Our results indicated a unique role of exosomic lncRUNX2-AS1 in transferring from MM cells to MSCs in osteogenic differentiation, through a novel exosomic lncRUNX2-AS1/RUNX2 signaling pathway.Figure legend. Characterization of exosomes derived from HMCLs (A) Representative TEM imaging of exosomes derived from U266 and MM1S (Bar = 100 nm). (B)Exosomes isolated from U266 and MM1S were measured by Nanoparticle Tracking Analysis (NanoSight). (C) Representative western blot of HSP70 and flotillin-1 proteins in MSCs-derived exosomes and HMCLs-derived exosomes. (D) BM-MSCs were cultured in the absence (control) or presence of U266 or MM1S-derived PKH67-labeled exosomes for 24 hours. Exosomes were uptaken by BM-MSCs, as shown using a confocal microscope (original magnification, ×400). BM-MSCs were stained using DAPI (nuclei) and FITC conjugated anti-actin antibody. (E) Flow cytometric analysis of HMCLs after incubation with fluorescently labeled exosomes. FL1 fluorescence indicates exosome uptake. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Bone-Targeted Pharmacological Inhibition of Notch Signaling As a Novel Approach to Inhibit Myeloma Growth and Bone Destruction

Notch signaling between myeloma cells and cells of the bone marrow microenvironment favors growth and survival of myeloma cells and increases osteoclast formation. In vitro and in vivo studies demonstrated that systemic inhibition of Notch signaling using gamma-secretase inhibitors (GSIs) decreases myeloma cell growth and reduces osteoclast generation. However, the use of GSIs in the clinic is limited by the ocurrence of severe adverse side effects as fatigue, skin disorders, and acute gastrointestinal toxicity. To circumvent the side effects associated with systemic inhibition of Notch signaling using GSIs, we synthesized a novel Notch inhibitor by linking GSI-XII to an inactive bone-targeting molecule (BT). BT-GSI was designed to direct the conjugate to bone where the linker is cleaved under the acidic environment generated by osteoclast activity, thus locally releasing the GSI.In vitro, the control unconjugated GSI decreased Notch target gene expression (Hes1) in 5TGM1 myeloma cells, but BT-GSI had no effect. However, when both GSI and BT-GSI were pre-incubated at low pH to mimic the acidic conditions in resorption sites, equal inhibition of Notch target gene expression was observed. Ex vivo, both GSI and BT-GSI (non-pre-incubated) similarly decreased Hes1/5 expression in whole bone organ cultures that reproduce conditions present in the bone microenvironment. In vivo, administration of BT-GSI (5µg/g, 3xwk) to normal 4-month old female mice for 2 weeks was well tolerated and no skin issues were observed. Mice treated with BT-GSI exhibited decreased Hey2, Hes5, and Hes7 mRNA expression in whole bone preparations, but not in brain or gut, compared to vehicle-treated mice. Further, BT-GSI did not increase Apsidin expression in the gut, a biomarker of gastrointestinal toxicity. BT-GSI-treated mice exhibited decreased serum levels of CTX (-40%), a bone resorption marker, and upregulated Opg mRNA expression in bone, thereby decreasing the Rankl/Opg ratio. Consistent with these findings, BT-GSI-treated mice exhibited a 50% decreased in the bone surface covered by osteoclasts compared to vehicle-treated control mice. BT-GSI treated mice exhibited higher total (+3%), femoral (+4%), and spinal (+7%) BMD compared to control mice. Further, mice receiving BT-GSI had increased cancellous bone volume (+25%) and trabecular thickness (+10%) compared to vehicle-treated mice, as quantified by microCT. Serum levels of the bone formation marker P1NP, as well as bone formation and mineral apposition rates, number of osteoblasts, and the expression of osteoblast markers, including Wnt target genes and the osteocyte- derived Sost/Sclerostin remained unchanged in bones of BT-GSI-treated mice compared to control mice.Taken together, these findings demonstrate that BT-GSI induces bone specific Notch inhibition, reduces osteoclast formation without affecting osteoblast activity, favoring bone gain, and lacks gut toxicity. Thus, BT-GSI is a promising approach to inhibit the growth of myeloma cells and prevent bone loss in myeloma patients, while circumventing the deleterious side effects of this class of inhibitors in other tissues. DisclosuresDelgado-Calle:PharmaMar: Research Funding. Roodman:PharmaMar: Research Funding. Bellido:PharmaMar: Research Funding.

Maternal Embryonic Leucine Zipper Kinase Inhibitor OTSSP167 Inhibits Osteoclast Activity and Restores Osteoblast Activity in a Murine Model of Multiple Myeloma Bone Disease

Multiple myeloma bone disease (MMBD) is characterized by an increased osteoclast activity and a decreased osteoblast differentiation in the multiple myeloma (MM) microenvironment, resulting in the development of lytic bone lesions. A large majority of MM patients suffer from MMBD, which not only causes morbidity but also negatively impacts patient survival. The development of novel therapies, ideally with a combined anti-resorptive and bone-anabolic effect, is of great interest because lytic lesions persist with the current standard of care, even in patients in complete remission. We have previously shown that maternal embryonic leucine zipper kinase (MELK) drives a high-risk gene network in MM and that MELK inhibition with OTSSP167 reduces tumor development in the 5TGM.1 model. In the current study, we assessed the effect of OTSSP167 treatment on bone cell activity and the development of MMBD.OTSSP167 inhibited osteoclast activity in vitro by decreasing monocytic progenitor cell viability as well as via a direct anti-resorptive effect on mature osteoclasts in both human (derived from PBMCs) and murine (RAW264.7) cell cultures. In addition, OTSSP167 stimulated matrix deposition and mineralization by human BMSC-TERT osteoblasts in vitro, which coincided with an increased expression of osterix . This combined anti-resorptive and osteoblast-stimulating effect of OTSSP167 resulted in the complete prevention of lytic lesions and bone loss in MM-bearing 5TGM.1 mice, as assessed by micro-computed tomography. OTSSP167 reduced the number of cortical perforations in MM-bearing mice, without affecting cortical thickness. The loss of trabecular bone volume that occurs in MM-bearing mice compared to healthy controls, was completely prevented, due to an increase in the number of trabeculae and a decrease in trabecular separation. Immunohistomorphometric analyses on the femurs of these mice showed that the increase in osteoclast surface observed in MM-bearing mice was completely prevented with OTSSP167 treatment. In addition, OTSSP167 treatment resulted in a recovery of osteoblast and osteoid surface levels.In conclusion, we show that OTSSP167 has a direct anti-MMBD effect in addition to its anti-MM activity, which warrants further clinical development of MELK inhibition in MM. [Display omitted] DisclosuresLudwig:Celgene: Speakers Bureau; Bristol-Meyers: Speakers Bureau; Takeda: Consultancy, Research Funding, Speakers Bureau; AMGEN: Consultancy, Research Funding, Speakers Bureau; Janssen-Cilag: Consultancy, Speakers Bureau; Takeda: Research Funding, Speakers Bureau.

Sclerostin-Mediated Impaired Osteogenesis by Fibroblast-Like Synoviocytes in the Particle-Induced Osteolysis Model.

Engineered biomaterials are envisioned to replace, augment, or interact with living tissues for improving the functional deformities associated with end-stage joint pathologies. Unfortunately, wear debris from implant interfaces is the major factor leading to periprosthetic osteolysis. Fibroblast-like synoviocytes (FLSs) populate the intimal lining of the synovium and are in direct contact with wear debris. This study aimed to elucidate the effect of Ti particles as wear debris on human FLSs and the mechanism by which they might participate in the bone remodeling process during periprosthetic osteolysis. FLSs were isolated from synovial tissue from patients, and the condition medium (CM) was collected after treating FLSs with sterilized Ti particles. The effect of CM was analyzed for the induction of osteoclastogenesis or any effect on osteogenesis and signaling pathways. The results demonstrated that Ti particles could induce activation of the NFκB signaling pathway and induction of COX-2 and inflammatory cytokines in FLSs. The amount of Rankl in the conditioned medium collected from Ti particle–stimulated FLSs (Ti CM) showed the ability to stimulate osteoclast formation. The Ti CM also suppressed the osteogenic initial and terminal differentiation markers for osteoprogenitors, such as alkaline phosphate activity, matrix mineralization, collagen synthesis, and expression levels of Osterix, Runx2, collagen 1α, and bone sialoprotein. Inhibition of the WNT and BMP signaling pathways was observed in osteoprogenitors after the treatment with the Ti CM. In the presence of the Ti CM, exogenous stimulation by WNT and BMP signaling pathways failed to stimulate osteogenic activity in osteoprogenitors. Induced expression of sclerostin (SOST: an antagonist of WNT and BMP signaling) in Ti particle–treated FLSs and secretion of SOST in the Ti CM were detected. Neutralization of SOST in the Ti CM partially restored the suppressed WNT and BMP signaling activity as well as the osteogenic activity in osteoprogenitors. Our results reveal that wear debris–stimulated FLSs might affect bone loss by not only stimulating osteoclastogenesis but also suppressing the bone-forming ability of osteoprogenitors. In the clinical setting, targeting FLSs for the secretion of antagonists like SOST might be a novel therapeutic approach for preventing bone loss during inflammatory osteolysis.

The skeletal consequences of epidural steroid injections: a literature review.

Approximately nine million epidural steroid injections (ESIs) are administered annually in the United States to treat radicular back pain. ESIs often provide pain relief and functional improvement. While the overall incidence of adverse events resulting from ESIs is low, their effects on the skeleton are poorly understood. This is an important consideration given the profound skeletal impact of other forms of glucocorticoids. Ovid MEDLINE and PubMed search results since 2010, including older, frequently referenced publications were reviewed. Systemic absorption of glucocorticoids occurs after ESI, which can cause hyperglycemia and endogenous cortisol suppression. The majority of studies investigating the skeletal effects of ESIs are retrospective. Several have found a relationship between low areal bone mineral density (BMD) by dual-energy x-ray absorptiometry and ESI exposure, but this finding is not uniform. Recently a dose-response relationship between ESI exposure and low spine volumetric BMD by computed tomography has been reported. Few studies have investigated the relationship between ESI exposure and fracture risk. Results of these studies are conflicting, and most have not been adequately powered to detect fracture outcomes. While evidence is limited, studies suggest that ESIs may cause bone loss, particularly those investigating volumetric BMD. Larger doses appear to confer greater risk. Further prospective studies are needed to investigate the relationship between ESI and fracture risk. Better understanding of the skeletal consequences of ESIs will help foster strategies to prevent bone loss in the growing population of patients receiving this treatment.

Effect of exercise training before and after bariatric surgery: A systematic review and meta-analysis.

SummaryWe aimed to assess the effectiveness of exercise training programs in adults with severe obesity undergoing bariatric surgery. A systematic search of controlled trials published up to October 2019 that assigned participants to either a preoperative or postoperative exercise training group or a nonexercise group was performed. Meta‐analyses were conducted using random‐effects models. Twenty‐two training programs were assessed (18 performed after bariatric surgery). The effect of preoperative exercise training on postsurgery outcomes was reported in only one study. Compared with the control condition without exercise, postoperative exercise training led to higher weight loss (N = 14, mean difference [95% CI] = −1.8 [−3.2; −0.4] kg, P = 0.01), fat loss (N = 9, P = 0.01), increase in VO2max (N = 8, P < 0.0001), and increase in muscle strength (N = 9, P < 0.0001). No significant effect was found on lean body mass (N = 11). Preliminary evidence suggests a beneficial effect of postoperative exercise training on bone mineral density (N = 3, P < 0.001) and weight maintenance after the end of the intervention (N = 2, P < 0.001) but no significant effect on quality of life (N = 2), habitual physical activity (N = 2), or cardiometabolic outcomes (N < 4). In conclusion, exercise training performed after bariatric surgery improves physical fitness and leads to a small additional weight and fat loss and may prevent bone loss and weight regain after bariatric surgery.

Green Tea Catechin, Epigallocatechin Gallate, Prevents Bone Loss in Hindlimb-Unloading Mice

Abstract Objectives Osteoporosis is a major health problem in the elderly characterized by bone loss and micro-architectural deterioration of bone tissue and associated with an increased risk of fracture. Prolonged bed rest, or physical inactivity during space flight causes rapid and marked bone loss. The effects of catechin, the main ingredient of Japanese green tea, on the bone are currently under study. It has been shown that green tea catechin modulates bone resorption in osteoclasts. However, there is no evidence supporting its inhibitory effect on bone loss during physical inactivity. In the present study, we investigated whether green tea catechin prevented bone loss through skeletal hindlimb-unloading in mice. Methods Female 8-week-old ddY mice were divided into five groups (n = 6–8 each) and subjected to: (1) normal housing fed a control diet, (2) sham unloading fed a control diet, (3) hind limb-unloading fed a control diet, (4) hind limb-unloading fed a 0.05% epigallocatechin gallate (EGCG)-containing diet, and (5) hind limb-unloading fed a 0.25% EGCG-containing diet for three weeks. Purified EGCG (97%) was used for green tea catechin. Results Bone mineral density of the tibia significantly decreased in hind limb-unloading mice. Treatment with 0.25% EGCG prevented bone loss and maintained trabecular bone mineral density more significantly than in cortical bones. The 0.25% EGCG diet inhibited decrease in the gene expression of alkaline phosphatase, a marker of bone formation, in the bone marrow in hind limb-unloading mice. Conclusions These results suggest that EGCG has ability to prevent bone loss induced by hindlimb-unloading in mice. These osteoprotective effects of EGCG may result from the inhibition of unloading-induced decrease in bone formation. Funding Sources This work was supported by the Honjo International Scholarship Foundation of Japan.