scholarly journals Regulation of Bone Cell Differentiation and Activation by Microbe-Associated Molecular Patterns

2021 ◽  
Vol 22 (11) ◽  
pp. 5805
Author(s):  
Yeongkag Kwon ◽  
Chaeyeon Park ◽  
Jueun Lee ◽  
Donghyun Park ◽  
Sungho Jeong ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Periodontal Diseases ◽  
Bone Destruction ◽  
Bone Cell ◽  
Bone Diseases ◽  
Bone Homeostasis ◽  
Bone Cell Differentiation ◽  
Molecular Patterns

Gut microbiota has emerged as an important regulator of bone homeostasis. In particular, the modulation of innate immunity and bone homeostasis is mediated through the interaction between microbe-associated molecular patterns (MAMPs) and the host pattern recognition receptors including Toll-like receptors and nucleotide-binding oligomerization domains. Pathogenic bacteria such as Porphyromonas gingivalis and Staphylococcus aureus tend to induce bone destruction and cause various inflammatory bone diseases including periodontal diseases, osteomyelitis, and septic arthritis. On the other hand, probiotic bacteria such as Lactobacillus and Bifidobacterium species can prevent bone loss. In addition, bacterial metabolites and various secretory molecules such as short chain fatty acids and cyclic nucleotides can also affect bone homeostasis. This review focuses on the regulation of osteoclast and osteoblast by MAMPs including cell wall components and secretory microbial molecules under in vitro and in vivo conditions. MAMPs could be used as potential molecular targets for treating bone-related diseases such as osteoporosis and periodontal diseases.

scholarly journals Immunological Reaction in TNF-α-Mediated Osteoclast Formation and Bone ResorptionIn VitroandIn Vivo

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Hideki Kitaura ◽  
Keisuke Kimura ◽  
Masahiko Ishida ◽  
Haruka Kohara ◽  
Masako Yoshimatsu ◽  
...  
Keyword(s):  
T Cells ◽  
Bone Metabolism ◽  
Stromal Cells ◽  
Fas Ligand ◽  
Bone Marrow Cells ◽  
Bone Destruction ◽  
Osteoclast Formation ◽  
Bone Diseases

Tumor necrosis factor-α(TNF-α) is a cytokine produced by monocytes, macrophages, and T cells and is induced by pathogens, endotoxins, or related substances. TNF-αmay play a key role in bone metabolism and is important in inflammatory bone diseases such as rheumatoid arthritis. Cells directly involved in osteoclastogenesis include macrophages, which are osteoclast precursor cells, osteoblasts, or stromal cells. These cells express receptor activator of NF-κB ligand (RANKL) to induce osteoclastogenesis, and T cells, which secrete RANKL, promote osteoclastogenesis during inflammation. Elucidating the detailed effects of TNF-αon bone metabolism may enable the identification of therapeutic targets that can efficiently suppress bone destruction in inflammatory bone diseases. TNF-αis considered to act by directly increasing RANK expression in macrophages and by increasing RANKL in stromal cells. Inflammatory cytokines such as interleukin- (IL-) 12, IL-18, and interferon-γ(IFN-γ) strongly inhibit osteoclast formation. IL-12, IL-18, and IFN-γinduce apoptosis in bone marrow cells treated with TNF-α  in vitro, and osteoclastogenesis is inhibited by the interactions of TNF-α-induced Fas and Fas ligand induced by IL-12, IL-18, and IFN-γ. This review describes and discusses the role of cells concerned with osteoclast formation and immunological reactions in TNF-α-mediated osteoclastogenesisin vitroandin vivo.

scholarly journals Protocol of Co-Culture of Human Osteoblasts and Osteoclasts to Test Biomaterials for Bone Tissue Engineering

2022 ◽  
Vol 5 (1) ◽  
pp. 8
Author(s):  
Giorgia Borciani ◽  
Giorgia Montalbano ◽  
Nicola Baldini ◽  
Chiara Vitale-Brovarone ◽  
Gabriela Ciapetti
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Bone Cells ◽  
Bone Cell ◽  
Seeding Density ◽  
Bone Homeostasis ◽  
Bone Microenvironment

New biomaterials and scaffolds for bone tissue engineering (BTE) applications require to be tested in a bone microenvironment reliable model. On this assumption, the in vitro laboratory protocols with bone cells represent worthy experimental systems improving our knowledge about bone homeostasis, reducing the costs of experimentation. To this day, several models of the bone microenvironment are reported in the literature, but few delineate a protocol for testing new biomaterials using bone cells. Herein we propose a clear protocol to set up an indirect co-culture system of human-derived osteoblasts and osteoclast precursors, providing well-defined criteria such as the cell seeding density, cell:cell ratio, the culture medium, and the proofs of differentiation. The material to be tested may be easily introduced in the system and the cell response analyzed. The physical separation of osteoblasts and osteoclasts allows distinguishing the effects of the material onto the two cell types and to evaluate the correlation between material and cell behavior, cell morphology, and adhesion. The whole protocol requires about 4 to 6 weeks with an intermediate level of expertise. The system is an in vitro model of the bone remodeling system useful in testing innovative materials for bone regeneration, and potentially exploitable in different application fields. The use of human primary cells represents a close replica of the bone cell cooperation in vivo and may be employed as a feasible system to test materials and scaffolds for bone substitution and regeneration.

scholarly journals The Role of NLRP3 Inflammasome Activities in Bone Diseases and Vascular Calcification

Inflammation ◽  
2020 ◽  
Author(s):  
Chenyang Yu ◽  
Caihua Zhang ◽  
Zhihui Kuang ◽  
Qiang Zheng
Keyword(s):  
Vascular Calcification ◽  
Nlrp3 Inflammasome ◽  
Periodontal Diseases ◽  
Bone Destruction ◽  
Bone Diseases ◽  
Sterile Inflammation ◽  
Inflammatory Factors ◽  
Bone Homeostasis ◽  
Caspase 1

Abstract Continuous stimulation of inflammation is harmful to tissues of an organism. Inflammatory mediators not only have an effect on metabolic and inflammatory bone diseases but also have an adverse effect on certain genetic and periodontal diseases associated with bone destruction. Inflammatory factors promote vascular calcification in various diseases. Vascular calcification is a pathological process similar to bone development, and vascular diseases play an important role in the loss of bone homeostasis. The NLRP3 inflammasome is an essential component of the natural immune system. It can recognize pathogen-related molecular patterns or host-derived dangerous signaling molecules, recruit, and activate the pro-inflammatory protease caspase-1. Activated caspase-1 cleaves the precursors of IL-1β and IL-18 to produce corresponding mature cytokines or recognizes and cleaves GSDMD to mediate cell pyroptosis. In this review, we discuss the role of NLRP3 inflammasome in bone diseases and vascular calcification caused by sterile or non-sterile inflammation and explore potential treatments to prevent bone loss.

Abstract 90: Serum Kawasaki Disease-specific Microbe-associated Molecular Patterns are Derived from in Vitro and in Vivo Biofilms

Circulation ◽  
2015 ◽  
Vol 131 (suppl_2) ◽  
Author(s):  
Takeshi Kusuda ◽  
Yasutaka Nakashima ◽  
Murata Kenji ◽  
Shunsuke Kanno ◽  
Mitsumasa Saito ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Yersinia Pseudotuberculosis ◽  
Molecular Structures ◽  
Human Coronary Artery ◽  
Medium Temperature ◽  
Molecular Patterns ◽  
Culture Supernatants

Background: We have found that serum KD-specific molecules possess molecular structures common to microbe-associated molecular patterns (MAMPs) from several bacteria by liquid chromatography-mass spectrometry (LC-MS) analysis. In the present study, we have extensively searched for the culture conditions that reproducibly produce MAMPs common to serum KD specific molecules. Methods: Yersinia pseudotuberculosis, spore-forming bacteria and pathogenic bacteria were obtained from KD patients. Others were purchased from American Type Culture Collection. Microbes were cultured in a variety of conditions (medium, temperature, duration, shaking and biofilm formation). For biofilm formation, a various kind of oil/butter was added to the culture medium. Extraction from in vitro samples (culture supernatants, bacteria cells, and biofilms) as well as in vivo biofilm samples (teeth, tongue, nasal cavity, or rectum) was performed with ethyl acetate. Samples were analyzed by HPLC and MS (Esquire 6000 electrospray ionization). Human coronary artery endothelial cells (HCAECs) were employed for cytokine assay. The concentrations of cytokines were measured by EC800 cell analyzer with a BD™ Cytometric Bead Array. Results: Serum KD-specific molecules showed m/z and MS/MS fragmentation patterns almost identical to those of MAMPs obtained from the biofilms formed in vitro (Bacillus cereus, Bacillus subtilis, Yersinia pseudotuberculosis, Staphylococcus aureus) or in vivo. Not culture supernatants but biofilm extracts from these bacteria, especially cultured in the presence of butter, induced proinflammatory cytokines by HCAECs. Conclusions: Extensive analysis by LC-MS/MS revealed that serum KD-specific molecules common to MAMPs were mostly derived from biofilms in vitro and in vivo. This report offers novel insight into the pathogenesis of KD.

scholarly journals β2-Adrenergic Receptor Signaling in Osteoblasts Contributes to the Catabolic Effect of Glucocorticoids on Bone

Endocrinology ◽  
2011 ◽  
Vol 152 (4) ◽  
pp. 1412-1422 ◽  
Author(s):  
Yun Ma ◽  
Jeffry S. Nyman ◽  
Huan Tao ◽  
Heather H. Moss ◽  
Xiangli Yang ◽  
...  
Keyword(s):  
Bone Loss ◽  
Bone Cells ◽  
Sympathetic Nerves ◽  
Bone Diseases ◽  
Autonomic Nerves ◽  
High Dose ◽  
Bone Homeostasis ◽  
Adrenergic Stimulation

Abstract The sympathetic nervous system is a physiological regulator of bone homeostasis. Autonomic nerves are indeed present in bone, bone cells express the β2-adrenergic receptors (β2AR), and pharmacological or genetic disruption of sympathetic outflow to bone induces bone gain in rodents. These recent findings implied that conditions that affect β2AR signaling in osteoblasts and/or sympathetic drive to bone may contribute to bone diseases. In this study, we show that dexamethasone stimulates the expression of the β2AR in differentiated primary calvarial osteoblasts, as measured by an increase in Adrβ2 mRNA and β2AR protein level after short-term dexamethasone treatment. Isoproterenol-induced cAMP accumulation and the expression of the β2AR target gene Rankl were also significantly increased after dexamethasone pretreatment, indicating that dexamethasone promotes the responsiveness of differentiated osteoblasts to adrenergic stimulation. These in vitro results led to the hypothesis that glucocorticoid-induced bone loss, provoked by increased endogenous or high-dose exogenous glucocorticoids given for the treatment of inflammatory diseases, might, at least in part, be mediated by increased sensitivity of bone-forming cells to the tonic inhibitory effect of sympathetic nerves on bone formation or their stimulatory effect on bone resorption. Supporting this hypothesis, both pharmacological and genetic β2AR blockade in mice significantly reduced the bone catabolic effect of high-dose prednisolone in vivo. This study emphasizes the importance of sympathetic nerves in the regulation of bone homeostasis and indicates that this neuroskeletal signaling axis can be modulated by hormones or drugs and contribute to enhance pathological bone loss.

scholarly journals Transcriptional Modulator Ifrd1 Regulates Osteoclast Differentiation through Enhancing the NF-κB/NFATc1 Pathway

2016 ◽  
Vol 36 (19) ◽  
pp. 2451-2463 ◽  
Author(s):  
Takashi Iezaki ◽  
Kazuya Fukasawa ◽  
Gyujin Park ◽  
Tetsuhiro Horie ◽  
Takashi Kanayama ◽  
...  
Keyword(s):  
Bone Loss ◽  
Osteoclast Differentiation ◽  
Nuclear Factor Κb ◽  
Bone Diseases ◽  
Nuclear Factor ◽  
Activator Protein 1 ◽  
Bone Homeostasis ◽  
Activated T Cells

Bone homeostasis is maintained by the synergistic actions of bone-resorbing osteoclasts and bone-forming osteoblasts. Here, we show that the transcriptional coactivator/repressor interferon-related developmental regulator 1 (Ifrd1) is expressed in osteoclast lineages and represents a component of the machinery that regulates bone homeostasis. Ifrd1 expression was transcriptionally regulated in preosteoclasts by receptor activator of nuclear factor κB (NF-κB) ligand (RANKL) through activator protein 1. Global deletion of murineIfrd1increased bone formation and decreased bone resorption, leading to a higher bone mass. Deletion ofIfrd1in osteoclast precursors prevented RANKL-induced bone loss, although no bone loss was observed under normal physiological conditions. RANKL-dependent osteoclastogenesis was impairedin vitroinIfrd1-deleted bone marrow macrophages (BMMs).Ifrd1deficiency increased the acetylation of p65 at residues K122 and K123 via the inhibition of histone deacetylase-dependent deacetylation in BMMs. This repressed the NF-κB-dependent transcription of nuclear factor of activated T cells, cytoplasmic 1 (NFATc1), an essential regulator of osteoclastogenesis. These findings suggest that an Ifrd1/NF-κB/NFATc1 axis plays a pivotal role in bone remodelingin vivoand represents a therapeutic target for bone diseases.

scholarly journals ELMO1 Regulates RANKL-Stimulated Differentiation and Bone Resorption of Osteoclasts

2021 ◽  
Vol 9 ◽  
Author(s):  
Xinyue Liang ◽  
Yafei Hou ◽  
Lijuan Han ◽  
Shuxiang Yu ◽  
Yunyun Zhang ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Bone Resorption ◽  
Bone Erosion ◽  
Osteoclast Differentiation ◽  
Small Gtpases ◽  
Bone Diseases ◽  
Bone Homeostasis ◽  
Nucleotide Exchange

Bone homeostasis is a metabolic balance between the new bone formation by osteoblasts and old bone resorption by osteoclasts. Excessive osteoclastic bone resorption results in low bone mass, which is the major cause of bone diseases such as rheumatoid arthritis. Small GTPases Rac1 is a key regulator of osteoclast differentiation, but its exact mechanism is not fully understood. ELMO and DOCK proteins form complexes that function as guanine nucleotide exchange factors for Rac activation. Here, we report that ELMO1 plays an important role in differentiation and bone resorption of osteoclasts. Osteoclast precursors derived from bone marrow monocytes (BMMs) of Elmo1–/– mice display defective adhesion and migration during differentiation. The cells also have a reduced activation of Rac1, p38, JNK, and AKT in response to RANKL stimulation. Importantly, we show that bone erosion is alleviated in Elmo1–/– mice in a rheumatoid arthritis mouse model. Taken together, our results suggest that ELMO1, as a regulator of Rac1, regulates osteoclast differentiation and bone resorption both in vitro and in vivo.

scholarly journals Intercellular Communication between Keratinocytes and Fibroblasts Induces Local Osteoclast Differentiation: a Mechanism Underlying Cholesteatoma-Induced Bone Destruction

2016 ◽  
Vol 36 (11) ◽  
pp. 1610-1620 ◽  
Author(s):  
Yoriko Iwamoto ◽  
Keizo Nishikawa ◽  
Ryusuke Imai ◽  
Masayuki Furuya ◽  
Maki Uenaka ◽  
...  
Keyword(s):  
Intercellular Communication ◽  
Osteoclast Differentiation ◽  
Bone Destruction ◽  
Nuclear Factor Κb ◽  
Bone Diseases ◽  
Epidermal Cyst ◽  
Bone Homeostasis ◽  
Lethal Complications ◽  
And Function

Bone homeostasis is maintained by a balance in activity between bone-resorbing osteoclasts and bone-forming osteoblasts. Shifting the balance toward bone resorption causes osteolytic bone diseases such as rheumatoid arthritis and periodontitis. Osteoclast differentiation is regulated by receptor activator of nuclear factor κB ligand (RANKL), which, under some pathological conditions, is produced by T and B lymphocytes and synoviocytes. However, the mechanism underlying bone destruction in other diseases is little understood. Bone destruction caused by cholesteatoma, an epidermal cyst in the middle ear resulting from hyperproliferation of keratinizing squamous epithelium, can lead to lethal complications. In this study, we succeeded in generating a model for cholesteatoma, epidermal cyst-like tissue, which has the potential for inducing osteoclastogenesis in mice. Furthermore, anin vitrococulture system composed of keratinocytes, fibroblasts, and osteoclast precursors was used to demonstrate that keratinocytes stimulate osteoclast differentiation through the induction of RANKL in fibroblasts. Thus, this study demonstrates that intercellular communication between keratinocytes and fibroblasts is involved in the differentiation and function of osteoclasts, which may provide the molecular basis of a new therapeutic strategy for cholesteatoma-induced bone destruction.

scholarly journals Focal adhesion protein Kindlin-2 regulates bone homeostasis in mice

Bone Research ◽  
2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Huiling Cao ◽  
Qinnan Yan ◽  
Dong Wang ◽  
Yumei Lai ◽  
Bo Zhou ◽  
...  
Keyword(s):  
Focal Adhesion ◽  
Neutralizing Antibody ◽  
Osteoclast Formation ◽  
Bone Diseases ◽  
Bone Homeostasis ◽  
Metabolic Bone Diseases ◽  
Adhesion Protein ◽  
Focal Adhesion Protein

AbstractOur recent studies demonstrate that the focal adhesion protein Kindlin-2 is critical for chondrogenesis and early skeletal development. Here, we show that deleting Kindlin-2 from osteoblasts using the 2.3-kb mouse Col1a1-Cre transgene minimally impacts bone mass in mice, but deleting Kindlin-2 using the 10-kb mouse Dmp1-Cre transgene, which targets osteocytes and mature osteoblasts, results in striking osteopenia in mice. Kindlin-2 loss reduces the osteoblastic population but increases the osteoclastic and adipocytic populations in the bone microenvironment. Kindlin-2 loss upregulates sclerostin in osteocytes, downregulates β-catenin in osteoblasts, and inhibits osteoblast formation and differentiation in vitro and in vivo. Upregulation of β-catenin in the mutant cells reverses the osteopenia induced by Kindlin-2 deficiency. Kindlin-2 loss additionally increases the expression of RANKL in osteocytes and increases osteoclast formation and bone resorption. Kindlin-2 deletion in osteocytes promotes osteoclast formation in osteocyte/bone marrow monocyte cocultures, which is significantly blocked by an anti-RANKL-neutralizing antibody. Finally, Kindlin-2 loss increases osteocyte apoptosis and impairs osteocyte spreading and dendrite formation. Thus, we demonstrate an important role of Kindlin-2 in the regulation of bone homeostasis and provide a potential target for the treatment of metabolic bone diseases.

scholarly journals 3-Hydroxyolean-12-en-27-oic Acids Inhibit RANKL-Induced Osteoclastogenesis in Vitro and Inflammation-Induced Bone Loss in Vivo

2020 ◽  
Vol 21 (15) ◽  
pp. 5240
Author(s):  
Wonyoung Seo ◽  
Suhyun Lee ◽  
Phuong Thao Tran ◽  
Thi Quynh-Mai Ngo ◽  
Okwha Kim ◽  
...  
Keyword(s):  
Bone Destruction ◽  
Osteoclast Formation ◽  
Bone Diseases ◽  
Marker Genes ◽  
Tartrate Resistant Acid Phosphatase ◽  
Specific Marker ◽  
Nuclear Factor ◽  
Activated T Cells

Olean-12-en-27-oic acids possess a variety of pharmacological effects. However, their effects and underlying mechanisms on osteoclastogenesis remain unclear. This study aimed to investigate the anti-osteoclastogenic effects of five olean-12-en-27-oic acid derivatives including 3α,23-isopropylidenedioxyolean-12-en-27-oic acid (AR-1), 3-oxoolean-12-en-27-oic acid (AR-2), 3α-hydroxyolean-12-en-27-oic acid (AR-3), 23-hydroxy-3-oxoolean-12-en-27-oic acid (AR-4), and aceriphyllic acid A (AR-5). Among the five olean-12-en-27-oic acid derivatives, 3-hydroxyolean-12-en-27-oic acid derivatives, AR-3 and AR-5, significantly inhibited receptor activator of nuclear factor-κB ligand (RANKL)-induced mature osteoclast formation by reducing the number of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts, F–actin ring formation, and mineral resorption activity. AR-3 and AR-5 decreased RANKL-induced expression levels of osteoclast-specific marker genes such as c-Src, TRAP, and cathepsin K (CtsK) as well as c-Fos and nuclear factor of activated T cells cytoplasmic 1 (NFATc1). Mice treated with either AR-3 or AR-5 showed significant protection of the mice from lipopolysaccharide (LPS)-induced bone destruction and osteoclast formation. In particular, AR-5 suppressed RANKL-induced phosphorylation of JNK and ERK mitogen-activated protein kinases (MAPKs). The results suggest that AR-3 and AR-5 attenuate osteoclast formation in vitro and in vivo by suppressing RANKL-mediated MAPKs and NFATc1 signaling pathways and could potentially be lead compounds for the prevention or treatment of osteolytic bone diseases.

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