Browsing by Subject "osteoclastogenesis"
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Item Cell adhesion molecule CD166 drives malignant progression and osteolytic disease in multiple myeloma(American Association for Cancer Research, 2016-12-01) Xu, Linlin; Mohammad, Khalid S.; Wu, Hao; Crean, Colin; Poteat, Bradley; Cheng, Yinghua; Cardoso, Angelo A.; Machal, Christophe; Hanenberg, Helmut; Abonour, Rafat; Kacena, Melissa A.; Chirgwin, John; Suvannasankha, Attaya; Srour, Edward F.; Microbiology and Immunology, School of MedicineMultiple myeloma (MM) is incurable once osteolytic lesions have seeded at skeletal sites, but factors mediating this deadly pathogenic advance remain poorly understood. Here we report evidence of a major role for the cell adhesion molecule CD166, which we discovered to be highly expressed in MM cell lines and primary bone marrow (BM) cells from patients. CD166+ MM cells homed more efficiently than CD166− cells to the BM of engrafted immunodeficient NSG mice. CD166 silencing in MM cells enabled longer survival, a smaller tumor burden and less osteolytic lesions, as compared to mice bearing control cells. CD166 deficiency in MM cell lines or CD138+ BM cells from MM patients compromised their ability to induce bone resorption in an ex vivo organ culture system. Further, CD166 deficiency in MM cells also reduced formation of osteolytic disease in vivo after intra-tibial engraftment. Mechanistic investigation revealed that CD166 expression in MM cells inhibited osteoblastogenesis of BM-derived osteoblast progenitors by suppressing RUNX2 gene expression. Conversely, CD166 expression in MM cells promoted osteoclastogenesis by activating TRAF6-dependent signaling pathways in osteoclast progenitors. Overall, our results define CD166 as a pivotal director in MM cell homing to the BM and MM progression, rationalizing its further study as a candidate therapeutic target for MM treatment.Item Effects of IL-34 and anti-IL-34 neutralizing mAb on alveolar bone loss in a ligature-induced model of periodontitis(Wiley, 2023-10-30) Duarte, Carolina; Yamada, Chiaki; Ngala, Bidii; Garcia, Christopher; Akkaoui, Juliet; Birsa, Maxim; Ho, Anny; Nusbaum, Amilia; AlQallaf, Hawra; John, Vanchit; Movila, Alexandru; Periodontology, School of DentistryMacrophage colony-stimulating factor (M-CSF) and interleukin-34 (IL-34) are ligands for the colony-stimulating factor-1 receptor (CSF-1r) expressed on the surface of monocyte/macrophage lineage cells. The importance of coordinated signaling between M-CSF/receptor activator of the nuclear factor kappa-Β ligand (RANKL) in physiological and pathological bone remodeling and alveolar bone loss in response to oral bacterial colonization is well established. However, our knowledge about the IL-34/RANKL signaling in periodontal bone loss remains limited. Recently published cohort studies have demonstrated that the expression patterns of IL-34 are dramatically elevated in gingival crevicular fluid collected from patients with periodontitis. Therefore, the present study aims to evaluate the effects of IL-34 on osteoclastogenesis in vitro and in experimental ligature-mediated model of periodontitis using male mice. Our initial in vitro study demonstrated increased RANKL-induced osteoclastogenesis of IL-34-primed osteoclast precursors (OCPs) compared to M-CSF-primed OCPs. Using an experimental model of ligature-mediated periodontitis, we further demonstrated elevated expression of IL-34 in periodontal lesions. In contrast, M-CSF levels were dramatically reduced in these periodontal lesions. Furthermore, local injections of mouse recombinant IL-34 protein significantly elevated cathepsin K activity, increased the number of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts and promoted alveolar bone loss in periodontitis lesions. In contrast, anti-IL-34 neutralizing monoclonal antibody significantly reduced the level of alveolar bone loss and the number of TRAP-positive osteoclasts in periodontitis lesions. No beneficial effects of locally injected anti-M-CSF neutralizing antibody were observed in periodontal lesions. This study illustrates the role of IL-34 in promoting alveolar bone loss in periodontal lesions and proposes the potential of anti-IL34 monoclonal antibody (mAb)-based therapeutic regimens to suppress alveolar bone loss in periodontitis lesions.Item Evaluation of osteoclastogenesis in the Ts65Dn Down Syndrome Mouse Model(Office of the Vice Chancellor for Research, 2015-04-17) Abeysekera, Irushi S.; Raje, Kimaya; Roper, Randall J.Down Syndrome (DS) affects ~1 in 700 live births and is caused by trisomy of human chromosome 21 (Hsa21). DS is characterized by a wide spectrum of phenotypes including cognitive and skeletal abnormalities that affect all individuals with DS. To study these phenotypes, we utilize the Ts65Dn mouse model, which contains three copies of approximately half the gene orthologous found on Hsa21 and exhibits similar phenotypes as found in humans with DS. Individuals with DS and Ts65Dn mice have deficits in bone mineral density (BMD), bone architecture, and bone strength. Three copies of DYRK1A, a serine-threonine kinase encoded on Hsa21, has been linked to deficiencies in bone homeostasis in DS mouse models and individuals with DS. DYRK1A is thought to act via NFATc1, a master regulator of osteoclastogenesis. Epigallocatechin-3-gallate (EGCG), a polyphenol found in high concentrations in green tea, is a known inhibitor of DYRK1A activity. We propose that the DS bone phenotype arises from an increase in osteoclastogenesis and/or maturation which results in increased bone resorption and disrupted bone homeostasis. We hypothesize that treatment of the mice during adolescence with 100 mg/kg/day EGCG would result in normalization of osteoclast numbers in trisomic mice to that of the controls. Osteoclast precursors from femur and spleen were isolated from 8-10 week old mice treated with 100 mg/kg/day EGCG or water from three weeks of age onwards. The cells were grown in the presence of M-CSF & RANK-L to promote osteoclast differentiation. Following 3 weeks in culture, the cells were fixed, TRAP stained, and multinucleated osteoclasts from control and Ts65Dn treated and untreated mice were counted. Mentor: Randall Roper, Department of Biology, IUPUI School of Science, Indianapolis, INItem Nmp4/CIZ suppresses the response of bone to anabolic parathyroid hormone by regulating both osteoblasts and osteoclasts(2011-07) Childress, Paul; Philip, Binu K.; Robling, Alexander G.; Bruzzaniti, Angela; Kacena, Melissa A.; Bivi, Nicoletta; Plotkin, Lilian I.; Heller, Aaron; Bidwell, Joseph P.How parathyroid hormone (PTH) increases bone mass is unclear, but understanding this phenomenon is significant to the improvement of osteoporosis therapy. Nmp4/CIZ is a nucleocytoplasmic shuttling transcriptional repressor that suppresses PTH-induced osteoblast gene expression and hormone-stimulated gains in murine femoral trabecular bone. To further characterize Nmp4/CIZ suppression of hormone-mediated bone growth, we treated 10-week-old Nmp4-knockout (KO) and wild-type (WT) mice with intermittent human PTH(1–34) at 30 μg/kg daily or vehicle, 7 days/week, for 2, 3, or 7 weeks. Null mice treated with hormone (7 weeks) gained more vertebral and tibial cancellous bone than WT animals, paralleling the exaggerated response in the femur. Interestingly, Nmp4/CIZ suppression of this hormone-stimulated bone formation was not apparent during the first 2 weeks of treatment. Consistent with the null mice enhanced PTH-stimulated addition of trabecular bone, these animals exhibited an augmented hormone-induced increase in serum osteocalcin 3 weeks into treatment. Unexpectedly, the Nmp4-KO mice displayed an osteoclast phenotype. Serum C-terminal telopeptide, a marker for bone resorption, was elevated in the null mice, irrespective of treatment. Nmp4-KO bone marrow cultures produced more osteoclasts, which exhibited elevated resorbing activity, compared to WT cultures. The expression of several genes critical to the development of both osteoblasts and osteoclasts was elevated in Nmp4-KO mice at 2 weeks, but not 3 weeks, of hormone exposure. We propose that Nmp4/CIZ dampens PTH-induced improvement of trabecular bone throughout the skeleton by transiently suppressing hormone-stimulated increases in the expression of proteins key to the required enhanced activity and number of both osteoblasts and osteoclasts.Item Role of miR-222-3p in c-Src-Mediated Regulation of Osteoclastogenesis(MDPI, 2016-02-16) Takigawa, Shinya; Chen, Andy; Wan, Qiaoqiao; Na, Sungsoo; Sudo, Akihiro; Yokota, Hiroki; Hamamura, Kazunori; Biomedical Engineering, School of Engineering and TechnologyMicroRNAs (miRNAs) are small non-coding RNAs that play a mostly post-transcriptional regulatory role in gene expression. Using RAW264.7 pre-osteoclast cells and genome-wide expression analysis, we identified a set of miRNAs that are involved in osteoclastogenesis. Based on in silico analysis, we specifically focused on miR-222-3p and evaluated its role in osteoclastogenesis. The results show that the inhibitor of miR-222-3p upregulated the mRNA levels of nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) and tartrate-resistant acid phosphatase (TRAP), while its mimicking agent downregulated their mRNA levels. Western blot analysis showed that its inhibitor increased the protein levels of TRAP and cathepsin K, while its mimicking agent decreased their levels. Genome-wide mRNA expression analysis in the presence and absence of receptor activator of nuclear factor κ-B ligand (RANKL) predicted c-Src as a potential regulatory target of miR-222-3p. Live cell imaging using a fluorescence resonance energy transfer (FRET) technique revealed that miR-222-3p acted as an inhibitor of c-Src activity, and a partial silencing of c-Src suppressed RANKL-induced expression of TRAP and cathepsin K, as well as the number of multi-nucleated osteoclasts and their pit formation. Collectively, the study herein demonstrates that miR-222-3p serves as an inhibitor of osteoclastogenesis and c-Src mediates its inhibition of cathepsin K and TRAP.