scholarly journals The Non-Erythropoietic EPO Analogue Cibinetide Inhibits Osteoclastogenesis In Vitro and Increases Bone Mineral Density in Mice

2021 ◽  
Vol 23 (1) ◽  
pp. 55
Author(s):  
Zamzam Awida ◽  
Almog Bachar ◽  
Hussam Saed ◽  
Anton Gorodov ◽  
Nathalie Ben-Califa ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Bone Loss ◽  
Bone Mineral ◽  
Molecular Mechanisms ◽  
Mineral Density ◽  
Female Mice ◽  
Epo Receptor

The two erythropoietin (EPO) receptor forms mediate different cellular responses to erythropoietin. While hematopoiesis is mediated via the homodimeric EPO receptor (EPOR), tissue protection is conferred via a heteromer composed of EPOR and CD131. In the skeletal system, EPO stimulates osteoclast precursors and induces bone loss. However, the underlying molecular mechanisms are still elusive. Here, we evaluated the role of the heteromeric complex in bone metabolism in vivo and in vitro by using Cibinetide (CIB), a non-erythropoietic EPO analogue that exclusively binds the heteromeric receptor. CIB is administered either alone or in combination with EPO. One month of CIB treatment significantly increased the cortical (~5.8%) and trabecular (~5.2%) bone mineral density in C57BL/6J WT female mice. Similarly, administration of CIB for five consecutive days to female mice that concurrently received EPO on days one and four, reduced the number of osteoclast progenitors, defined by flow cytometry as Lin−CD11b−Ly6Chi CD115+, by 42.8% compared to treatment with EPO alone. In addition, CIB alone or in combination with EPO inhibited osteoclastogenesis in vitro. Our findings introduce CIB either as a stand-alone treatment, or in combination with EPO, as an appealing candidate for the treatment of the bone loss that accompanies EPO treatment.

scholarly journals The Non-Erythropoietic EPO Analogue (Cibinetide) Preserves Bone Mass in Mice

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 850-850
Author(s):  
Zamzam Awida ◽  
Almog Bachar ◽  
Hussam Saed ◽  
Anton Gorodov ◽  
Nathalie Ben-Califa ◽  
...  
Keyword(s):  
Bone Loss ◽  
Cancer Biology ◽  
Molecular Mechanisms ◽  
Conflicts Of Interest ◽  
Erythroid Progenitors ◽  
Mineral Density ◽  
Female Mice ◽  
Tissue Protection

Abstract Background and aims: Erythropoietin (EPO) is a pleiotropic cytokine, which besides its classical role in driving erythropoiesis, displays tissue protective and immunomodulatory activities. EPO also induces bone loss. While hematopoiesis is mediated via the homodimeric EPO receptor (EPOR), tissue protection is conferred via a heteromer composed of EPOR and CD131. Cibinetide (CIB), a non-erythropoietic analogue of EPO, specifically binds to the heteromeric receptor and confers tissue protection. Our published findings that EPO stimulates osteoclast precursors and entrains a decrease in bone density, raise questions regarding the underlying molecular mechanisms. Here, we evaluated the role of the heteromeric complex in bone metabolism using CIB alone and in combination with EPO in vivo and in vitro. Results: CIB injections to 12-week-old female mice (120 µg/kg thrice weekly for 4 weeks) resulted in a significant increase in tissue mineral density in cortical bone by 5.8% (1416.4±39.27 vs 1338.74±16.56 mgHA/cm 3) and in trabecular bone by 5.2% (1056.52±30.94 vs 1004.13±16.91 mg HA/cm 3) (n=10 in each group, p< 0.05 versus saline-injected controls), as measured by microCT (Figure 1A). To evaluate the capacity of CIB to attenuate EPO mediated bone loss, we administered CIB (300 µg/kg) for 5 consecutive days, to 13-week-old female mice that also received 2 injections of 120U EPO on days 1 and 4. Flow cytometry analysis revealed a 1.8-fold reduction in the number of osteoclast progenitors, defined as Lin -CD11b −CD115 +Ly6C hi, in the EPO + CIB injected mice, compared to the mice injected with EPO alone (n=7 in each group, p< 0.05). Hemoglobin levels and TER119 + bone marrow (BM) erythroid progenitors were similar in both groups. In vitro, EPO administration to BM-derived macrophages (BMDM) enhanced osteoclastogenesis, whereas CIB had an opposite, dose-dependent effect. Combining CIB with EPO inhibited osteoclastogenesis in BMDM, suggesting that CIB overrides the pro-osteoclastogenic effect of EPO (Figure 1B). Conclusions: Our findings highlight the increasing complexity of EPOR signaling in bone and pave the way for clinical translation through potential combination therapy of EPO and CIB in anemic and in cancer patients. Adjunctive administration of CIB may prevent or attenuate bone loss while preserving the erythropoietic actions of EPO. This study was supported by a grant from the Dotan Hemato-oncology Fund, the Cancer Biology Research Center, Tel Aviv University to DN and YG. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

In Vitro and in Vivo Spiral CT to Determine Bone Mineral Density: Initial Experience in Patients at Risk for Osteoporosis

Radiology ◽  
2004 ◽  
Vol 231 (3) ◽  
pp. 805-811 ◽  
Author(s):  
Thomas M. Link ◽  
Boris B. Koppers ◽  
Thomas Licht ◽  
Jan Bauer ◽  
Ying Lu ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
At Risk ◽  
Bone Mineral ◽  
Spiral Ct ◽  
Initial Experience ◽  
Mineral Density ◽  
Patients At Risk

scholarly journals Bone mineral density (BMD) and computer tomographic measurements of the equine proximal phalanx in correlation with breaking strength

2013 ◽  
Vol 16 (1) ◽  
pp. 3-8 ◽  
Author(s):  
P. Tóth ◽  
C. Horváth ◽  
V. Ferencz ◽  
B. Tóth ◽  
A. Váradi ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Fracture Risk ◽  
Bone Mineral ◽  
Risk Model ◽  
Breaking Strength ◽  
Proximal Phalanx ◽  
Ct Images ◽  
Mineral Density

Abstract Despite the fact that bone mineral density (BMD) is an important fracture risk predictor in human medicine, studies in equine orthopedic research are still lacking. We hypothesized that BMD correlates with bone failure and fatigue fractures of this bone. Thus, the objectives of this study were to measure the structural and mechanical properties of the proximal phalanx with dual energy X-ray absorptiometry (DXA), to correlate the data obtained from DXA and computer tomography (CT) measurements to those obtained by loading pressure examination and to establish representative region of interest (ROI) for in vitro BMD measurements of the equine proximal phalanx for predicting bone failure force. DXA was used to measure the whole bone BMD and additional three ROI sites in 14 equine proximal phalanges. Following evaluation of the bone density, whole bone, cortical width and area in the mid-diaphyseal plane were measured on CT images. Bones were broken using a manually controlled universal bone crusher to measure bone failure force and reevaluated for the site of fractures on follow-up CT images. Compressive load was applied at a constant displacement rate of 2 mm/min until failure, defined as the first clear drop in the load measurement. The lowest BMD was measured at the trabecular region (mean ± SD: 1.52 ± 0.12 g/cm2; median: 1.48 g/cm2; range: 1.38-1.83 g/cm2). There was a significant positive linear correlation between trabelcular BMD and the breaking strength (P=0.023, r=0.62). The trabecular region of the proximal phalanx appears to be the only significant indicator of failure of strength in vitro. This finding should be reassessed to further reveal the prognostic value of trabecular BMD in an in vivo fracture risk model.

Erk1 Plays Critical Role in Macrophage Development

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 517-517 ◽  
Author(s):  
Yongzheng He ◽  
Karl Staser ◽  
Steven D Rhodes ◽  
Xiaohua Wu ◽  
Ping Zhang ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Bone Marrow ◽  
Bone Mineral ◽  
Type I ◽  
Mineral Density ◽  
Macrophage Differentiation ◽  
Fold Reduction ◽  
The Impact

Abstract Abstract 517 Extracellular signal-regulated kinase (ERK 1 and 2) are widely expressed and are involved in the regulation of meiosis, mitosis, and postmitotic functions in multiple cell lineages, including T cells, B cells and osteoblasts. Macrophages are capable of differentiating into osteoclasts, which resorb bone. Abnormal osteoclast development and functions underlie certain diseases, especially skeletal defects. Altered ERK1/2 signaling has been found in several genetic diseases with skeletal phenotypes, including Noonan syndrome, polycystic kidney disease and serious developmental disorders such as cardio-facio-cutaneous syndrome. These clinical findings suggest the importance of the ERK MAPK pathway in human skeletal development. In the present study, we examined the consequence of Erk1 and Erk2 disruption in modulating macrophage development in the murine system. We found that deletion of Erk1 reduced macrophage progenitor numbers. Erk1−/− bone marrow mononuclear cells (BMMNCs) had significant reduction in osteoclast formation as compared to wildtype BMMNCs. In addition, Erk1−/− macrophages; the osteoclast progenitors, had a two-three fold reduction in migration and a two-fold reduction in αv ß3 mediated adhesion as compared to WT macrophages as evaluated by transwell and adhesion assay, respectively. These in vitro data demonstrate that Erk1 positively regulates macrophage differentiation into osteoclasts. To evaluate the impact of deficiency of Erk1 in vivo, we examined bone mineral density and trabecular microarchitecture in the distal femoral metaphysis by dual-energy X-ray absorptiometry (DEXA) with a Lunar Piximus densitometer and a high-resolution desktop microcomputed tomography imaging system (μCT-20; Scanco Medical AG, Basserdorf, Switzerland), respectively. Erk1−/− mice displayed elevated bone mineral density and increased trabecular bone formation as compared to WT mice. Histomorphometric analysis indicated that the Erk1−/− femur had significant reduction in osteoclast numbers as determined by tartrate resistant acid phosphatase staining, an osteoclast specific staining, as compared to femur of wildtype and Erk2−/− mice. Most importantly, Erk1−/− plasma had reduced C-terminal telopeptide of type I collagen, indicating less bone resorption in vivo. These data suggest that the impaired macrophage differentiation and osteoclast bone resorptive activity play an important role in increased bone mass in Erk1−/− mice. Finally, to verify that the macrophage-osteoclast lineage is a key cell lineage for the phenotypic changes in vivo in Erk1−/− mice, we performed bone marrow transplantation. WT mice reconstituted long-term with Erk1−/− hematopoietic stem cells demonstrated increased bone mineral density as compared to WT and Erk2−/− stem cell recipients, implicating marrow autonomous, Erk1-dependent macrophage differentiation and osteoclast bioactivity in vivo. Collectively, our in vitro and in vivo data demonstrate isoform-specific Erk function in macrophage while providing rationale for the development of a specific inhibitor for Erk1 that might be used for the treatment of dysplastic and erosive bone diseases. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Anti–IL-20 monoclonal antibody inhibits the differentiation of osteoclasts and protects against osteoporotic bone loss

2011 ◽  
Vol 208 (9) ◽  
pp. 1849-1861 ◽  
Author(s):  
Yu-Hsiang Hsu ◽  
Wei-Yu Chen ◽  
Chien-Hui Chan ◽  
Chih-Hsing Wu ◽  
Zih-Jie Sun ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Bone Loss ◽  
Therapeutic Potential ◽  
Osteoclast Differentiation ◽  
Bone Destruction ◽  
Osteoporotic Bone ◽  
Mineral Density

IL-20 is a proinflammatory cytokine of the IL-10 family that is involved in psoriasis, rheumatoid arthritis, atherosclerosis, and stroke. However, little is known about the role of IL-20 in bone destruction. We explored the function of IL-20 in osteoclastogenesis and the therapeutic potential of anti–IL-20 monoclonal antibody 7E for treating osteoporosis. Higher serum IL-20 levels were detected in patients with osteopenia and osteoporosis and in ovariectomized (OVX) mice. IL-20 mediates osteoclastogenesis by up-regulating the receptor activator of NF-κB (RANK) expression in osteoclast precursor cells and RANK ligand (RANKL) in osteoblasts. 7E treatment completely inhibited osteoclast differentiation induced by macrophage colony-stimulating factor (M-CSF) and RANKL in vitro and protected mice from OVX-induced bone loss in vivo. Furthermore, IL-20R1–deficient mice had significantly higher bone mineral density (BMD) than did wild-type controls. IL-20R1 deficiency also abolished IL-20–induced osteoclastogenesis and increased BMD in OVX mice. We have identified a pivotal role of IL-20 in osteoclast differentiation, and we conclude that anti–IL-20 monoclonal antibody is a potential therapeutic for protecting against osteoporotic bone loss.

Circulating Activin-A Is Elevated in Patients with Thalassemia Major and Double Heterozygous Sickle-Cell/Beta-Thalassemia and Correlates with Markers of Hemolysis and Bone Mineral Density

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3256-3256
Author(s):  
Ersi Voskaridou ◽  
Dimitrios Christoulas ◽  
Maria Dimopoulou ◽  
Veroniki Komninaka ◽  
Maria Tsalkani ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Sickle Cell ◽  
Bone Mineral ◽  
Thalassemia Major ◽  
Activin A ◽  
Beta Thalassemia ◽  
Mineral Density ◽  
Development In Vitro

Abstract Abstract 3256 Activins are typical members of the transforming growth factor beta superfamily in that they contain a conserved cysteine knot motif and are secreted as homo- or heterodimers of related beta-subunits. Activins seem to be implicated in the regulation of erythropoiesis and bone metabolism. Many studies have documented erythropoietic effects of activin-A in transformed cell lines or other in vitro models; however, there is a paucity of functional data regarding hematopoietic roles of activin-A in vivo. Regarding bone remodeling, activin A is produced by osteoblasts, osteoclasts, and bone marrow cells, and there is agreement that activin-A promotes osteoclast development in vitro; however, the effect of activin-A on osteoblast development in vitro varies dramatically depending on experimental conditions. It is of interest that activin-A antagonists (i.e. sotatercept) have increased hemoglobin and bone mineral density (BMD) in patients with multiple myeloma who receive chemotherapy, giving the rationale for their use in other hematological disorders with anemia, like myelodysplastic syndromes. Thalassemia is characterized by ineffective hemopoiesis, while osteopenia or osteoporosis is found in the vast majority of patients due to several reasons including bone marrow expansion and endocrine disorders. The role of activin-A has never been evaluated in hemoglobinopathies. The aim of this study was to examine the role of activin-A in different hemoglobinopathies in an attempt to explore if there is any rationale for the use of activin-A antagonists in this cohort of patients. Therefore, we measured circulating levels of activin-A in 227 patients with hemoglobinopathies: 58 patients had beta-thalassemia major (TM), 43 had beta-thalassemia intermedia (TI), 109 had double heterozygous sickle-cell/beta-thalassemia (HbS/beta-thal) and 17 had homozygous sickle cell disease (SCD) and we explored possible correlations with clinical and laboratory data including bone mineral density (BMD). Activin-A was also measured in the serum of 17, age- and gender-matched, healthy individuals who served as controls. For the evaluation of activin-A, we used an ELISA methodology (Quantikine, R&D Systems, Minneapolis, MN, USA). BMD of the lumbar spine (L1-L4), femoral neck (FN) and distal radius (R) was determined using Dual-energy X-ray absorptiometry (DXA) at the time of activin-A measurement. Patients with TM (mean±SD: 481±213 pg/ml) and HbS/beta-thal (459±181 pg/ml) had elevated circulating activin-A compared to controls (361±87 pg/ml; p=0.041 and p=0.038, respectively). Furthermore, TM patients had higher activin-A levels compared to patients with TI (427±509 pg/ml, p=0.002), while circulating activin-A levels did not differ between TI patients and controls (p=0.811) or between SCD patients (422±132 pg/ml) and controls (p=0.202). In patients with TM, high circulating activin-A showed strong correlations with markers of hemolysis, such as elevated reticulocyte counts (r=0.406, p=0.011) and high lactate dehydrogenase (LDH; r=0.397, p=0.024). Similarly, in HbS/beta-thal patients, activin-A showed positive correlations with indirect bilirubin (r=0.399, p<0.001), ferritin (r=0.270, p=0.005) and LDH (r=0.194, p=0.044). Regarding BMD, osteoporosis (according to the WHO definition based on DXA data) was present in 45% of patients with TM, in 40% of patients with TI, in 33% of SCD patients and in 25% of patients with HbS/beta-thal. High activin-A correlated with low Z-score of L1-L4 BMD in TI patients (r=0.615, p<0.01) and low Z-score of FN-BMD in TM patients (r=0.456, p<0.01). Our data suggest that activin-A is elevated in the serum of patients with TM and HbS/beta-thal and correlates with markers of hemolysis and low BMD. These observations in addition to previously published data that single nucleotide polymorphisms in activin-A receptor type II-like 1 independently contributes to pulmonary hypertension in SCD support a role of activin-A in the biology of these hemoglobinopathies, making activin-A an attractive agent for the development of novel therapies. The strong correlation of high activin-A with bone loss also supports the use of activin-A antagonists in patients with thalassemia and osteopenia or osteoporosis. Disclosures: No relevant conflicts of interest to declare.

Europium-Doped Gd2O3 Nanotubes Increase Bone Mineral Density in Vivo and Promote Mineralization in Vitro

2017 ◽  
Vol 9 (7) ◽  
pp. 5784-5792 ◽  
Author(s):  
Huifang Liu ◽  
Yi Jin ◽  
Kun Ge ◽  
Guang Jia ◽  
Zhenhua Li ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Bone Mineral ◽  
Mineral Density ◽  
Increase Bone Mineral Density

scholarly journals The Rho GTPase RAC1 in Osteoblasts Controls Their Function

2020 ◽  
Vol 21 (2) ◽  
pp. 385
Author(s):  
Katrin Huck ◽  
Carla Sens ◽  
Carina Wuerfel ◽  
Caren Zoeller ◽  
Inaam A. Nakchbandi
Keyword(s):  
Bone Mineral Density ◽  
Parathyroid Hormone ◽  
Signaling Pathways ◽  
Bone Mineral ◽  
Osteoblast Differentiation ◽  
Rho Gtpase ◽  
Mineral Density ◽  
Osteoblast Function

The regulation of the differentiation of the bone-forming cells, the osteoblasts, is complex. Many signaling pathways converge on the master regulator of osteoblast differentiation Runx2. The role of molecules that integrate several signaling pathways such as the Rho GTPases need to be better understood. We, therefore, asked at which stage Rac1, one of the Rho GTPase, is needed for osteoblast differentiation and whether it is involved in two pathways, the anabolic response to parathyroid hormone and the stimulatory effect of fibronectin isoforms on integrins. Genetic deletion of Rac1 in preosteoblasts using the osterix promoter diminished osteoblast differentiation in vitro. This effect was however similar to the presence of the promoter by itself. We, therefore, applied a Rac1 inhibitor and confirmed a decrease in differentiation. In vivo, Rac1 deletion using the osterix promoter decreased bone mineral density as well as histomorphometric measures of osteoblast function. In contrast, deleting Rac1 in differentiating osteoblasts using the collagen α1(I) promoter had no effects. We then evaluated whether intermittent parathyroid hormone (PTH) was able to affect bone mineral density in the absence of Rac1 in preosteoblasts. The increase in bone mineral density was similar in control animals and in mice in which Rac1 was deleted using the osterix promoter. Furthermore, stimulation of integrin by integrin isoforms was able to enhance osteoblast differentiation, despite the deletion of Rac1. In summary, Rac1 in preosteoblasts is required for normal osteoblast function and bone density, but it is neither needed for PTH-mediated anabolic effects nor for integrin-mediated enhancement of differentiation.

scholarly journals Negative Association Between Sclerostin and INSL3 in Isolated Human Osteocytes and in Klinefelter Syndrome: New Hints for Testis–Bone Crosstalk

2018 ◽  
Vol 103 (5) ◽  
pp. 2033-2041 ◽  
Author(s):  
Andrea Di Nisio ◽  
Luca De Toni ◽  
Maria Santa Rocca ◽  
Marco Ghezzi ◽  
Riccardo Selice ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Bone Formation ◽  
Bone Mineral ◽  
Klinefelter Syndrome ◽  
Negative Association ◽  
Negative Regulator ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mineral Density

Abstract Context The regulation of bone mass by the testis is a well-recognized mechanism, but the role of Leydig-specific marker insulin-like 3 peptide (INSL3) on the most abundant bone cell population, osteocytes, is unknown. In this study, we aimed to investigate the relationship between INSL3 and sclerostin, an osteocyte-specific protein that negatively regulates bone formation. Design Serum sclerostin and INSL3 levels were evaluated in Klinefelter syndrome (KS) and healthy controls. In vitro effect of INSL3 on sclerostin production was evaluated in human cultured osteocytes. Patients A total of 103 KS patients and 60 age- and sex-matched controls were recruited. Main Outcome Measures Serum sclerostin and INSL3 levels were assessed by enzyme-linked immunosorbent assay. Osteocytes were isolated by fluorescence-assisted cell sorting. Sclerostin expression was evaluated by western blot, immunofluorescence, and reverse transcription polymerase chain reaction. Measurement of bone mineral density was done by dual-energy X-ray absorptiometry at lumbar spine (L1–L4) and femoral neck. Results Sclerostin levels were significantly increased in KS subjects, and negatively correlated with INSL3 levels in both cohorts and with bone mineral density in the KS group. Stimulation of cultured osteocytes with INSL3 at 10−7 M significantly decreased both sclerostin messenger RNA and protein expression. Conclusions We report a negative association between the testicular hormone INSL3 and the osteocytic negative regulator of bone formation, sclerostin. We further explored this association in vitro and showed that INSL3 was able to reduce sclerostin expression. These results add further knowledge on the emerging role of sclerostin as a therapeutic target for osteoporosis treatment.

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