scholarly journals Bifunctional Role of CrkL during Bone Remodeling

2021 ◽  
Vol 22 (13) ◽  
pp. 7007
Author(s):  
Jung Ha Kim ◽  
Kabsun Kim ◽  
Inyoung Kim ◽  
Semun Seong ◽  
Hyun Kook ◽  
...  
Keyword(s):  
Osteoblast Differentiation ◽  
Osteoclast Differentiation ◽  
Bone Morphogenetic Protein 2 ◽  
Bone Homeostasis ◽  
Rankl Expression ◽  
Reverse Signaling ◽  
Complex Interactions ◽  
Morphogenetic Protein ◽  
Related Transcription Factor ◽  
Sarcoma Virus

Coupled signaling between bone-forming osteoblasts and bone-resorbing osteoclasts is crucial to the maintenance of bone homeostasis. We previously reported that v-crk avian sarcoma virus CT10 oncogene homolog-like (CrkL), which belongs to the Crk family of adaptors, inhibits bone morphogenetic protein 2 (BMP2)-mediated osteoblast differentiation, while enhancing receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclast differentiation. In this study, we investigated whether CrkL can also regulate the coupling signals between osteoblasts and osteoclasts, facilitating bone homeostasis. Osteoblastic CrkL strongly decreased RANKL expression through its inhibition of runt-related transcription factor 2 (Runx2) transcription. Reduction in RANKL expression by CrkL in osteoblasts resulted in the inhibition of not only osteoblast-dependent osteoclast differentiation but also osteoclast-dependent osteoblast differentiation, suggesting that CrkL participates in the coupling signals between osteoblasts and osteoclasts via its regulation of RANKL expression. Therefore, CrkL bifunctionally regulates osteoclast differentiation through both a direct and indirect mechanism while it inhibits osteoblast differentiation through its blockade of both BMP2 and RANKL reverse signaling pathways. Collectively, these data suggest that CrkL is involved in bone homeostasis, where it helps to regulate the complex interactions of the osteoblasts, osteoclasts, and their coupling signals.

scholarly journals Anti-Müllerian Hormone Negatively Regulates Osteoclast Differentiation by Suppressing the Receptor Activator of Nuclear Factor-κB Ligand Pathway

2021 ◽  
Vol 28 (3) ◽  
pp. 223-230
Author(s):  
Jung Ha Kim ◽  
Yong Ryoul Yang ◽  
Ki-Sun Kwon ◽  
Nacksung Kim
Keyword(s):  
Osteoblast Differentiation ◽  
Bone Cells ◽  
Osteoclast Differentiation ◽  
Nuclear Factor Κb ◽  
Bone Morphogenetic Protein 2 ◽  
Tartrate Resistant Acid Phosphatase ◽  
Nuclear Factor ◽  
Bone Homeostasis ◽  
Alizarin Red ◽  
Receptor Activator

Background: Multiple members of the transforming growth factor-β (TGF-β) superfamily have well-established roles in bone homeostasis. Anti-Müllerian hormone (AMH) is a member of TGF-β superfamily of glycoproteins that is responsible for the regression of fetal Müllerian ducts and the transcription inhibition of gonadal steroidogenic enzymes. However, the involvement of AMH in bone remodeling is unknown. Therefore, we investigated whether AMH has an effect on bone cells as other TGF-β superfamily members do.Methods: To identify the roles of AMH in bone cells, we administered AMH during osteoblast and osteoclast differentiation, cultured the cells, and then stained the cultured cells with Alizarin red and tartrate-resistant acid phosphatase, respectively. We analyzed the expression of osteoblast- or osteoclast-related genes using real-time polymerase chain reaction and western blot.Results: AMH does not affect bone morphogenetic protein 2-mediated osteoblast differentiation but inhibits receptor activator of nuclear factor-κB (NF-κB) ligand-induced osteoclast differentiation. The inhibitory effect of AMH on osteoclast differentiation is mediated by IκB-NF-κB signaling.Conclusions: AMH negatively regulates osteoclast differentiation without affecting osteoblast differentiation.

scholarly journals Biological Mechanisms of Paeonoside in the Differentiation of Pre-Osteoblasts and the Formation of Mineralized Nodules

2021 ◽  
Vol 22 (13) ◽  
pp. 6899
Author(s):  
Kyung-Ran Park ◽  
Joon Yeop Lee ◽  
Myounglae Cho ◽  
Jin Tae Hong ◽  
Hyung-Mun Yun
Keyword(s):  
Osteoblast Differentiation ◽  
Bone Diseases ◽  
Bone Morphogenetic Protein 2 ◽  
Nodule Formation ◽  
Biological Mechanisms ◽  
Cytotoxic Effects ◽  
Runx2 Expression ◽  
Migration Assay ◽  
Morphogenetic Protein ◽  
Related Transcription Factor

Paeonia suffruticosa is a magnificent and long-lived woody plant that has traditionally been used to treat various diseases including inflammatory, neurological, cancer, and cardiovascular diseases. In the present study, we demonstrated the biological mechanisms of paeonoside (PASI) isolated from the dried roots of P. suffruticosa in pre-osteoblasts. Herein, we found that PASI has no cytotoxic effects on pre-osteoblasts. Migration assay showed that PASI promoted wound healing and transmigration in osteoblast differentiation. PASI increased early osteoblast differentiation and mineralized nodule formation. In addition, PASI enhanced the expression of Wnt3a and bone morphogenetic protein 2 (BMP2) and activated their downstream molecules, Smad1/5/8 and β-catenin, leading to increases in runt-related transcription factor 2 (RUNX2) expression during osteoblast differentiation. Furthermore, PASI-mediated osteoblast differentiation was attenuated by inhibiting the BMP2 and Wnt3a pathways, which was accompanied by reduction in the expression of RUNX2 in the nucleus. Taken together, our findings provide evidence that PASI enhances osteoblast differentiation and mineralized nodules by regulating RUNX2 expression through the BMP2 and Wnt3a pathways, suggesting a potential role for PASI targeting osteoblasts to treat bone diseases including osteoporosis and periodontitis.

scholarly journals Kruppel-like factor 4 attenuates osteoblast formation, function, and cross talk with osteoclasts

2014 ◽  
Vol 204 (6) ◽  
pp. 1063-1074 ◽  
Author(s):  
Jung Ha Kim ◽  
Kabsun Kim ◽  
Bang Ung Youn ◽  
Jongwon Lee ◽  
Inyoung Kim ◽  
...  
Keyword(s):  
Bone Formation ◽  
Osteoblast Differentiation ◽  
Target Genes ◽  
Bone Marrow Cells ◽  
Osteoclast Differentiation ◽  
Nuclear Factor Κb ◽  
Conditional Knockout ◽  
Mouse Bone Marrow ◽  
Bone Homeostasis ◽  
Rankl Expression

Osteoblasts not only control bone formation but also support osteoclast differentiation. Here we show the involvement of Kruppel-like factor 4 (KLF4) in the differentiation of osteoclasts and osteoblasts. KLF4 was down-regulated by 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) in osteoblasts. Overexpression of KLF4 in osteoblasts attenuated 1,25(OH)2D3-induced osteoclast differentiation in co-culture of mouse bone marrow cells and osteoblasts through the down-regulation of receptor activator of nuclear factor κB ligand (RANKL) expression. Direct binding of KLF4 to the RANKL promoter repressed 1,25(OH)2D3-induced RANKL expression by preventing vitamin D receptor from binding to the RANKL promoter region. In contrast, ectopic overexpression of KLF4 in osteoblasts attenuated osteoblast differentiation and mineralization. KLF4 interacted directly with Runx2 and inhibited the expression of its target genes. Moreover, mice with conditional knockout of KLF4 in osteoblasts showed markedly increased bone mass caused by enhanced bone formation despite increased osteoclast activity. Thus, our data suggest that KLF4 controls bone homeostasis by negatively regulating both osteoclast and osteoblast differentiation.

scholarly journals Bone Morphogenetic Protein-2 in Development and Bone Homeostasis

2020 ◽  
Vol 8 (3) ◽  
pp. 19 ◽  
Author(s):  
Daniel Halloran ◽  
Hilary W. Durbano ◽  
Anja Nohe
Keyword(s):  
Bone Morphogenetic Protein ◽  
Bone Morphogenetic Proteins ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Bone Morphogenetic Protein 2 ◽  
Osteogenic Potential ◽  
Bone Homeostasis ◽  
Spinal Fusion Surgery ◽  
Morphogenetic Protein ◽  
Related Transcription Factor

Bone morphogenetic proteins (BMPs) are multi-functional growth factors belonging to the Transforming Growth Factor-Beta (TGF-β) superfamily. These proteins are essential to many developmental processes, including cardiogenesis, neurogenesis, and osteogenesis. Specifically, within the BMP family, Bone Morphogenetic Protein-2 (BMP-2) was the first BMP to be characterized and has been well-studied. BMP-2 has important roles during embryonic development, as well as bone remodeling and homeostasis in adulthood. Some of its specific functions include digit formation and activating osteogenic genes, such as Runt-Related Transcription Factor 2 (RUNX2). Because of its diverse functions and osteogenic potential, the Food and Drug Administration (FDA) approved usage of recombinant human BMP-2 (rhBMP-2) during spinal fusion surgery, tibial shaft repair, and maxillary sinus reconstructive surgery. However, shortly after initial injections of rhBMP-2, several adverse complications were reported, and alternative therapeutics have been developed to limit these side-effects. As the clinical application of BMP-2 is largely implicated in bone, we focus primarily on its role in bone. However, we also describe briefly the role of BMP-2 in development. We then focus on the structure of BMP-2, its activation and regulation signaling pathways, BMP-2 clinical applications, and limitations of using BMP-2 as a therapeutic. Further, this review explores other potential treatments that may be useful in treating bone disorders.

Targeting EZH2 Ameliorates the LPS-Inhibited PDLSC Osteogenesis via Wnt/β-Catenin Pathway

2021 ◽  
pp. 1-9
Author(s):  
Mosha Cheng ◽  
Qing Zhou
Keyword(s):  
Bone Morphogenetic Protein 2 ◽  
Periodontal Ligament Stem Cells ◽  
Alizarin Red ◽  
Protein Levels ◽  
Inflammatory Conditions ◽  
Morphogenetic Protein ◽  
Related Transcription Factor ◽  
Underlying Mechanisms ◽  
Factor Α ◽  
Osteoblast Maturation

As a histone methyltransferase, enhancer of zeste homolog 2 (EZH2), suppresses osteoblast maturation and is involved in inflammation. However, the role of EZH2 in human periodontal ligament stem cells (PDLSCs) under inflammation still needs to be further investigated. This study aimed to identify the underlying mechanisms and explore the function of EZH2 in PDLSC osteogenesis under inflammation. PDLSCs were treated with sh-EZH2, DZNep or DKK1 under inflammation. The alkaline phosphatase (ALP) activity, alizarin red staining, and osteogenesis-related protein levels were analyzed. Lipopolysaccharide (LPS)-induced inflammation restrained osteogenic differentiation. Under inflammation, the upregulation of EZH2 suppressed the expression of osteogenic markers, including osteocalcin, runt-related transcription factor 2, and bone morphogenetic protein-2, the activity of ALP, and the accumulation of mineralization through the Wnt/β-catenin pathway. EZH2 knockdown inhibited the levels of proinflammatory cytokines such as interleukin-6 and tumor necrosis factor-α. These results suggested that LPS-induced overexpression of EZH2 suppressed PDLSC osteogenesis under inflammatory conditions through the Wnt/β-catenin pathway. These findings give new insights into the physiological differentiation and pathological inflammation of PDLSC osteogenesis, and provide an underlying therapeutic target for periodontitis.

scholarly journals Connectivity Map-based discovery of parbendazole reveals targetable human osteogenic pathway

2015 ◽  
Vol 112 (41) ◽  
pp. 12711-12716 ◽  
Author(s):  
Andrea M. Brum ◽  
Jeroen van de Peppel ◽  
Cindy S. van der Leije ◽  
Marijke Schreuders-Koedam ◽  
Marco Eijken ◽  
...  
Keyword(s):  
Gene Expression ◽  
Alkaline Phosphatase ◽  
Osteoblast Differentiation ◽  
Target Genes ◽  
Focal Adhesions ◽  
Bone Fragility ◽  
Bone Morphogenetic Protein 2 ◽  
Marker Genes ◽  
Connectivity Map ◽  
Morphogenetic Protein

Osteoporosis is a common skeletal disorder characterized by low bone mass leading to increased bone fragility and fracture susceptibility. In this study, we have identified pathways that stimulate differentiation of bone forming osteoblasts from human mesenchymal stromal cells (hMSCs). Gene expression profiling was performed in hMSCs differentiated toward osteoblasts (at 6 h). Significantly regulated genes were analyzed in silico, and the Connectivity Map (CMap) was used to identify candidate bone stimulatory compounds. The signature of parbendazole matches the expression changes observed for osteogenic hMSCs. Parbendazole stimulates osteoblast differentiation as indicated by increased alkaline phosphatase activity, mineralization, and up-regulation of bone marker genes (alkaline phosphatase/ALPL, osteopontin/SPP1, and bone sialoprotein II/IBSP) in a subset of the hMSC population resistant to the apoptotic effects of parbendazole. These osteogenic effects are independent of glucocorticoids because parbendazole does not up-regulate glucocorticoid receptor (GR) target genes and is not inhibited by the GR antagonist mifepristone. Parbendazole causes profound cytoskeletal changes including degradation of microtubules and increased focal adhesions. Stabilization of microtubules by pretreatment with Taxol inhibits osteoblast differentiation. Parbendazole up-regulates bone morphogenetic protein 2 (BMP-2) gene expression and activity. Cotreatment with the BMP-2 antagonist DMH1 limits, but does not block, parbendazole-induced mineralization. Using the CMap we have identified a previously unidentified lineage-specific, bone anabolic compound, parbendazole, which induces osteogenic differentiation through a combination of cytoskeletal changes and increased BMP-2 activity.

scholarly journals The Dual Role of Oat Bran Water Extract in Bone Homeostasis Through the Regulation of Osteoclastogenesis and Osteoblast Differentiation

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3119 ◽  
Author(s):  
Shin-Hye Kim ◽  
Kwang-Jin Kim ◽  
Hyeon Kang ◽  
Young-Jin Son ◽  
Sik-Won Choi ◽  
...  
Keyword(s):  
Osteoblast Differentiation ◽  
Metabolic Disorders ◽  
Bone Fractures ◽  
Osteoclast Differentiation ◽  
Water Extract ◽  
In Vivo Model ◽  
Bone Homeostasis ◽  
Number Of Patients ◽  
Oat Bran

The number of patients with bone metabolic disorders including osteoporosis is increasing worldwide. These disorders often facilitate bone fractures, which seriously impact the patient’s quality of life and could lead to further health complications. Bone homeostasis is tightly regulated to balance bone resorption and formation. However, many anti-osteoporotic agents are broadly categorized as either bone forming or anti-resorptive, and their therapeutic use is often limited due to unwanted side effects. Therefore, safe and effective therapeutic agents are needed for osteoporosis. This study aims to clarify the bone protecting effects of oat bran water extract (OBWE) and its mode of action. OBWE inhibited RANKL (receptor activator of nuclear factor-κB ligand)-induced osteoclast differentiation by blocking c-Fos/NFATc1 through the alteration of I-κB. Furthermore, we found that OBWE enhanced BMP-2-stimulated osteoblast differentiation by the induction of Runx2 via Smad signaling molecules. In addition, the anti-osteoporotic activity of OBWE was also evaluated using an in vivo model. OBWE significantly restored ovariectomy-induced bone loss. These in vitro and in vivo results showed that OBWE has the potential to prevent and treat bone metabolic disorders including osteoporosis.

Bone morphogenetic protein 2 controls steroid-induced osteonecrosis of the femoral head via directly inhibiting interleukin-34 expression

2021 ◽  
Author(s):  
Meng Wang ◽  
Hong Sung Min ◽  
Haojie Shan ◽  
Yiwei Lin ◽  
Wenyang Xia ◽  
...  
Keyword(s):  
Femoral Head ◽  
Bone Morphogenetic Protein ◽  
Inflammatory Responses ◽  
Gene Knockout ◽  
Osteoclast Differentiation ◽  
Bone Morphogenetic Protein 2 ◽  
Qrt Pcr ◽  
Morphogenetic Protein ◽  
Local Expression

Increased inflammatory responses is one of the major characteristics of osteonecrosis of the femoral head (ONFH). We aimed to investigate the function of bone morphogenetic protein 2 (BMP-2)/interleukin (IL)-34 axis in the inflammatory responses of ONFH. The systemic and local expression of BMPs in ONFH patients were detected by qRT-PCR and ELISA. In vitro osteoclast differentiation and ONFH mouse models, induced by 20 mg/kg methylprednisolone through intramuscular injection, were established using wild type and BMP-2-/- mice to explore the regulatory role of BMP-2 in pro-inflammatory responses and bone defects of ONFH. IL-34 expression and function were examined in vitro and in vivo through qRT-PCR, TRAP staining, and gene knockout. The systemic and local expression of BMPs were elevated in ONFH patients. BMP-2 reduced the production of pro-inflammatory cytokines and inhibited the differentiation of osteoclasts. Mechanistically, BMP-2 inhibited osteoclasts formation through suppressing IL-34 expression, and then promoted bone repair and alleviated ONFH. In conclusion, our study reveals that BMP-2 inhibits inflammatory responses and osteoclast formation through down-regulating IL-34.

scholarly journals Statin-induced Ras Activation Integrates the Phosphatidylinositol 3-Kinase Signal to Akt and MAPK for Bone Morphogenetic Protein-2 Expression in Osteoblast Differentiation

2006 ◽  
Vol 282 (7) ◽  
pp. 4983-4993 ◽  
Author(s):  
Nandini Ghosh-Choudhury ◽  
Chandi Charan Mandal ◽  
Goutam Ghosh Choudhury
Keyword(s):  
Bone Morphogenetic Protein ◽  
Osteoblast Differentiation ◽  
Dominant Negative ◽  
Bone Morphogenetic Protein 2 ◽  
Regulatory Subunit ◽  
Type I ◽  
Dependent Manner ◽  
Phosphatidylinositol 3 Kinase ◽  
Morphogenetic Protein ◽  
Phosphatidylinositol 3

Lovastatin promotes osteoblast differentiation by increasing bone morphogenetic protein-2 (BMP-2) expression. We demonstrate that lovastatin stimulates tyrosine phosphorylation of the p85 regulatory subunit of phosphatidylinositol 3-kinase (PI3K), leading to an increase in its kinase activity in osteoblast cells. Inhibition of PI3K ameliorated expression of the osteogenic markers alkaline phosphatase, type I collagen, osteopontin, and BMP-2. Expression of dominant-negative PI3K and PTEN, an inhibitor of PI3K signaling, significantly attenuated lovastatin-induced transcription of BMP-2. Akt kinase was also activated in a PI3K-dependent manner. However, our data suggest involvement of an additional signaling pathway. Lovastatin-induced Erk1/2 activity contributed to BMP-2 transcription. Inhibition of PI3K abrogated Erk1/2 activity in response to lovastatin, indicating the presence of a signal relay between them. We provide, as a mechanism of this cross-talk, the first evidence that lovastatin stimulates rapid activation of Ras, which associates with and activates PI3K in the plasma membrane, which in turn regulates Akt and Erk1/2 to induce BMP-2 expression for osteoblast differentiation.

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