scholarly journals Metformin attenuates osteoclast-mediated abnormal subchondral bone remodeling and alleviates osteoarthritis via AMPK/NF-κB/ERK signaling pathway

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261127
Author(s):  
Haohui Guo ◽  
Dong Ding ◽  
Limei Wang ◽  
Jiangbo Yan ◽  
Long Ma ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Bone Resorption ◽  
Signaling Pathway ◽  
Subchondral Bone ◽  
Mapk Signaling ◽  
Erk Signaling ◽  
Tartrate Resistant Acid Phosphatase ◽  
Dependent Manner ◽  
Nuclear Factor ◽  
Osteoclast Activation

This study explored the mechanism by which metformin (Met) inhibits osteoclast activation and determined its effects on osteoarthritis (OA) mice. Bone marrow-derived macrophages were isolated. Osteoclastogenesis was detected using tartrate-resistant acid phosphatase (TRAP) staining. Cell proliferation was evaluated using CCK-8, F-actin rings were detected by immunofluorescence staining, and bone resorption was detected using bone slices. Nuclear factor kappa-B (NF-κB) and nuclear factor of activated T-cell cytoplasmic 1 (NFATc1) were detected using luciferase assays, and the adenosine monophosphate-activated protein kinase (AMPK), NF-κB, and mitogen-activated protein kinase (MAPK) signaling pathways were detected using western blotting. Finally, expression of genes involved in osteoclastogenesis was measured using quantitative polymerase chain reaction. A knee OA mouse model was established by destabilization of the medial meniscus (DMM). Male C57BL/6J mice were assigned to sham-operated, DMM+vehicle, and DMM+Met groups. Met (100 mg/kg/d) or vehicle was administered from the first day postoperative until sacrifice. At 4- and 8-week post OA induction, micro-computed tomography was performed to analyze microstructural changes in the subchondral bone, hematoxylin and eosin staining and Safranin-O/Fast Green staining were performed to evaluate the degenerated cartilage, TRAP-stained osteoclasts were enumerated, and receptor activator of nuclear factor κB ligand (RANKL), AMPK, and NF-κB were detected using immunohistochemistry. BMM proliferation was not affected by Met treatment below 2 mM. Met inhibited osteoclast formation and bone resorption in a dose-dependent manner in vitro. Met suppressed RANKL-induced activation of p-AMPK, NF-κB, phosphorylated extracellular regulated protein kinases (p-ERK) and up-regulation of genes involved in osteoclastogenesis. Met reversed decreases in BV/TV, Tb.Th, Tb.N, and CD, and an increase in Tb.Sp at 4 weeks postoperatively. The number of osteoclasts and OARSI score were decreased by Met without effect on body weight or blood glucose levels. Met inhibited RANKL, p-AMPK, and NF-κB expression in early OA. The mechanism by which Met inhibits osteoclast activation may be associated with AMPK/NF-κB/ERK signaling pathway, indicating a novel strategy for OA treatment.

scholarly journals The emerging role of IMD 0354 on bone homeostasis by suppressing osteoclastogenesis and bone resorption, but without affecting bone formation

2019 ◽  
Vol 10 (9) ◽  
Author(s):  
Wenxiang Chen ◽  
Ziang Xie ◽  
Pan Tang ◽  
Yongli Wang ◽  
Zhiwei Jie ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Formation ◽  
Osteoclast Differentiation ◽  
Nuclear Factor Κb ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Therapeutic Drug ◽  
Tartrate Resistant Acid Phosphatase ◽  
Nuclear Factor ◽  
Bone Homeostasis

Abstract Osteoporosis is caused by an imbalance between bone formation and bone resorption. Receptor activator of nuclear factor-κB ligand (RANKL) promotes the activity and differentiation of osteoclasts via activating the nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. IMD 0354 is a selective molecular inhibitor of inhibitor of NF-κB kinase subunit beta (IKKβ) and effective for treatment of acute and subacute inflammatory diseases through the suppression of NF-κB activation. However, the effect of IMD 0354 on bone homeostasis is unknown. In this study, we demonstrated that IMD 0354 significantly attenuated ovariectomy-induced bone loss and inhibited osteoclastogenesis in mice, whereas bone formation was not affected. Additionally, IMD 0354 dramatically inhibited osteoclast differentiation and function induced by RANKL and macrophage colony-stimulating factor in bone marrow monocytes as verified by tartrate-resistant acid phosphatase (TRAP) staining as well as bone resorption assay in vitro. Subsequently, we found that activation of NF-κB signaling and the ERK/c-Fos axis were blunted during osteoclast formation induced by RANKL. Transcription factors nuclear factor of activated T cells c1 (NFATc1) and c-Fos were suppressed with the decreased expression of osteoclast-related genes by IMD 0354. Our findings suggest that IMD 0354 could be a potential preventive and therapeutic drug for osteoporosis.

scholarly journals Antineuroinflammatory Effects of Modified Wu-Zi-Yan-Zong Prescription in β-Amyloid-Stimulated BV2 Microglia via the NF-κB and ERK/p38 MAPK Signaling Pathways

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Qian Yu ◽  
Fang-Jiao Song ◽  
Jin-Feng Chen ◽  
Xin Dong ◽  
Yong Jiang ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Signaling Pathway ◽  
P38 Mapk ◽  
Nuclear Translocation ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Nuclear Factor ◽  
Amyloid A ◽  
Mitogen Activated Protein ◽  
Bv2 Microglia

Modified Wu-Zi-Yan-Zong prescription (MWP), a traditional Chinese medicinal decoction, has possessed the neuroprotective and anti-inflammatory properties. The mechanisms associated with these properties, however, are not completely understood. We designed the experiments to elucidate the antineuroinflammatory property of MWP in BV2 microglia activated by β-amyloid (Aβ), which is a characteristic feature of Alzheimer’s disease (AD). The composition of MWP was studied using HPLC. BV2 microglia cells were then treated with Aβ in the presence or absence of MWP. The effects of MWP treatment on Aβ-activated neuroinflammation were determined using PCR, western blotting, and immunofluorescence staining. MWP significantly inhibited the mRNA expression of inflammatory mediators such as IL-1β, IL-6, TNF-α, and MCP-1, as well as the expression of inducible nitric oxide synthase (iNOS) in Aβ-activated BV2 microglia. MWP also inhibited the nuclear translocation and signaling pathway of nuclear factor kappa B (NF-κB) by suppressing inhibitor of nuclear factor-κB (IκB) degradation and downregulating IκB kinase β (IKKβ) phosphorylation. Moreover, MWP decreased extracellular regulated protein kinase (ERK)/p38 mitogen-activated protein kinase (MAPK) phosphorylation, which is an important signaling pathway for proinflammatory gene expression. We concluded that MWP could suppress neuroinflammatory responses in Aβ-activated BV2 microglia via the NF-κB and ERK/p38 MAPK signaling cascades and could prove an effective therapeutic agent for the prevention and treatment of neuroinflammatory diseases such as AD.

scholarly journals Dietary nitrate supplementation prevents radiotherapy-induced xerostomia

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Xiaoyu Feng ◽  
Zhifang Wu ◽  
Junji Xu ◽  
Yipu Xu ◽  
Bin Zhao ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Protein Kinase ◽  
Parotid Gland ◽  
Signaling Pathway ◽  
Mapk Signaling ◽  
Mapk Signaling Pathway ◽  
Dependent Manner ◽  
Dietary Nitrate ◽  
Gland Tissue ◽  
Nitrate Supplementation

Management of salivary gland hypofunction caused by irradiation (IR) therapy for head and neck cancer remains lack of effective treatments. Salivary glands, especially the parotid gland, actively uptake dietary nitrate and secrete it into saliva. Here, we investigated the effect of dietary nitrate on the prevention and treatment of IR-induced parotid gland hypofunction in miniature pigs, and elucidated the underlying mechanism in human parotid gland cells (hPGCs). We found that nitrate administration prevented IR-induced parotid gland damage in a dose-dependent manner, by maintaining the function of irradiated parotid gland tissue. Nitrate could increase sialin expression, a nitrate transporter expressed in the parotid gland, making the nitrate-sialin feedback loop that facilitates nitrate influx into cells for maintaining cell proliferation and inhibiting apoptosis. Furthermore, nitrate enhanced cell proliferation via the epidermal growth factor receptor (EGFR)-protein kinase B (AKT)-mitogen-activated protein kinase (MAPK) signaling pathway in irradiated parotid gland tissue. Collectively, nitrate effectively prevented IR-induced xerostomia via the EGFR–AKT-MAPK signaling pathway. Dietary nitrate supplementation may provide a novel, safe, and effective way to resolve IR-induce xerostomia.

scholarly journals Acupotomy Contributes to Suppressing Subchondral Bone Resorption in KOA Rabbits by Regulating the OPG/RANKL Signaling Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Tong Wang ◽  
Yan Guo ◽  
Xiao-Wei Shi ◽  
Yang Gao ◽  
Jia-Yi Zhang ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Signaling Pathway ◽  
Subchondral Bone ◽  
Therapeutic Potential ◽  
Cartilage Degeneration ◽  
Bone Lesions ◽  
Surface Erosion ◽  
Tartrate Resistant Acid Phosphatase ◽  
Osteoclast Activity ◽  
Osteoblast Activity

Subchondral bone lesions, as the crucial inducement for accelerating cartilage degeneration, have been considered as the initiating factor and the potential therapeutic target of knee osteoarthritis (KOA). Acupotomy, the biomechanical therapy guided by traditional Chinese meridians theory, alleviates cartilage deterioration by correcting abnormal mechanics. Whether this mechanical effect of acupotomy inhibits KOA subchondral bone lesions is indistinct. This study aimed to investigate the effects of acupotomy on inhibiting subchondral bone resorption and to define the possible mechanism in immobilization-induced KOA rabbits. After KOA modeling, 8 groups of rabbits (4w/6w acupotomy, 4w/6w electroacupuncture, 4w/6w model, and 4w/6w control groups) received the indicated intervention for 3 weeks. Histological and bone histomorphometry analyses revealed that acupotomy prevented both cartilage surface erosion and subchondral bone loss. Further, acupotomy suppressed osteoclast activity and enhanced osteoblast activity in KOA subchondral bone, showing a significantly decreased expression of tartrate-resistant acid phosphatase (TRAP), matrix metalloproteinases-9 (MMP-9), and cathepsin K (Ctsk) and a significantly increased expression of osteocalcin (OCN); this regulation may be mediated by blocking the decrease in osteoprotegerin (OPG) and the increase in NF- κ B receptor activated protein ligand (RANKL). These findings indicated that acupotomy inhibited osteoclast activity and promoted osteoblast activity to ameliorate hyperactive subchondral bone resorption and cartilage degeneration in immobilization-induced KOA rabbits, which may be mediated by the OPG/RANKL signaling pathway. Taken together, our results indicate that acupotomy may have therapeutic potential in KOA by restoring the balance between bone formation and bone resorption to attenuate subchondral bone lesions.

scholarly journals Oleanolic Acid Acetate Exerts Anti-Inflammatory Activity via IKKα/β Suppression in TLR3-Mediated NF-κB Activation

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 4002 ◽  
Author(s):  
Hyung Jin Lim ◽  
Hyun-Jae Jang ◽  
Mi Hwa Kim ◽  
Soyoung Lee ◽  
Seung Woong Lee ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Oleanolic Acid ◽  
Inflammatory Cytokines ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Nuclear Factor ◽  
Anti Inflammatory ◽  
Tlr3 Signaling

Oleanolic acid acetate (OAA), a major triterpenoid compound of Vigna angularis (azuki bean, V. angularis), has been shown to downregulate inflammatory responses in macrophages. Here, we show the molecular basis for the effect of OAA on Toll-like receptor (TLR) downstream signaling. OAA treatment significantly inhibited the secretion of embryonic alkaline phosphatase (SEAP) induced by polyinosinic acid (poly(I), TLR3 ligand) in a dose-dependent manner and without cytotoxicity in THP1-XBlue cells. In addition, OAA downregulated the gene expression of poly(I) induced pro-inflammatory cytokines and chemokines genes such as MCP-1, IL-1β, IL-8, VCAM-1 and ICAM-1. Furthermore, we found that the inhibition activity of OAA was accompanied by decreased activation of not only nuclear factor-kappa B (NF-κB) signaling but also mitogen-activated protein kinase (MAPK) signaling upon stimulation with the TLR3 agonist. Interestingly, the interaction of OAA with IκB kinase α/β (IKKα/β) strongly attenuated the production of certain proteins and inflammatory cytokines in the TLR3 signaling pathway, such as nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IkBα), extracellular regulated kinases (ERK), and p38, in an in vitro model. The action of OAA was regulated by TLR3, demonstrating that TLR3 plays a critical role in mediating the physiologically-relevant anti-inflammatory action of OAA and that the interaction with IKKα/β is modulated through TLR3. These results reveal new insight into the understanding of the regulatory mechanisms of the downstream TLR3 signaling pathway and consequent inflammatory responses that are involved in the development and progression of inflammatory diseases.

scholarly journals Chronic intermittent hypoxia disturbs insulin secretion and causes pancreatic injury via the MAPK signaling pathway

2017 ◽  
Vol 95 (3) ◽  
pp. 415-420 ◽  
Author(s):  
Yeying Wang ◽  
Bing Hai ◽  
Xiaoqun Niu ◽  
Li Ai ◽  
Yu Cao ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Protein Kinase ◽  
Signaling Pathway ◽  
Cell Apoptosis ◽  
Intermittent Hypoxia ◽  
Mapk Signaling ◽  
Pancreatic Tissue ◽  
Mapk Signaling Pathway ◽  
Chronic Intermittent Hypoxia ◽  
Dependent Manner

Obstructive sleep apnea (OSA) is a breathing disorder during sleep, with a most prominent character of chronic intermittent hypoxia (CIH), which induces the generation of reactive oxygen species (ROS) that damages multiple tissues and causes metabolic disorders. In this study, we established a rat model of varying OSA with different grades of CIH (12.5% O2, 10% O2, 7.5% O2, and 5% O2) for 12 weeks, and found that CIH stimulated insulin secretion, reduced the insulin:proinsulin ratio in pancreatic tissue, and caused pancreatic tissue lesions and cell apoptosis in a dose-dependent manner. Moreover, CIH promoted the production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6, and activated mitogen-activated protein kinase (MAPK) family members, extracellular regulated protein kinase (ERK), c-Jun N-terminal kinase (JNK), and P38, depending on the O2 concentration. In summary, CIH disturbed insulin secretion, and caused inflammation, lesions, and cell apoptosis in pancreatic tissue via the MAPK signaling pathway, which may be of great significance for clinical treatment of OSA and type 2 diabetes mellitus (T2DM).

Orostachys japonicus Suppresses Osteoclast Differentiation by Inhibiting NFATc1 Expression

2015 ◽  
Vol 43 (05) ◽  
pp. 1013-1030 ◽  
Author(s):  
Ki-Shuk Shim ◽  
Hyunil Ha ◽  
Taesoo Kim ◽  
Chung-Jo Lee ◽  
Jin Yeul Ma
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Therapeutic Potential ◽  
Osteoclast Differentiation ◽  
Water Extract ◽  
Bone Diseases ◽  
Tartrate Resistant Acid Phosphatase ◽  
Dependent Manner ◽  
Nuclear Factor ◽  
Activated T Cells

The herb Orostachys japonicus has been traditionally used to treat chronic diseases, such as hepatitis, hemorrhoids, and cancer, in Asia. In this study, we investigated the effect of Orostachys japonicus water extract (OJWE) on the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation and bone loss. We found that OJWE inhibited RANKL-induced osteoclast differentiation in a dose-dependent manner without affecting bone resorption in bone marrow-derived macrophage cells. Interestingly, OJWE significantly reduced serum levels of C-terminal telopeptide of type 1 collagen and tartrate-resistant acid phosphatase (TRAP) 5b, markers of bone resorption and osteoclast number, respectively, in an animal model of bone loss. Furthermore, OJWE suppressed the RANKL-induced up-regulation of nuclear factor of activated T cells cytoplasmic 1 (NFATc1) expression, and activation of the p38 signaling pathway, but prevented the RANKL-mediated down-regulation of interferon regulatory factor-8 (IRF-8), which is known to be an anti-osteoclastogenic factor that represses NFATc1 expression. We also identified gallic acid and quercetin-3-O-β-D-glucoside as the OJWE components that inhibit RANKL-induced osteoclast differentiation. These results suggest that OJWE inhibits osteoclast differentiation by inhibiting RANKL-induced NFATc1 expression, which prevents osteoclast differentiation and bone loss. The present study elucidated a mechanism of action underlying the inhibitory effect of OJWE on osteoclast differentiation. Our findings suggest that O. japonicus has therapeutic potential for use in the treatment of bone diseases.

scholarly journals Decitabine Inhibits Bone Resorption in Periodontitis by Upregulating Anti-Inflammatory Cytokines and Suppressing Osteoclastogenesis

Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 199
Author(s):  
Urara Tanaka ◽  
Shunichi Kajioka ◽  
Livia S. Finoti ◽  
Daniela B. Palioto ◽  
Denis F. Kinane ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Bone Resorption ◽  
Bone Loss ◽  
Inflammatory Cytokines ◽  
Osteoclast Differentiation ◽  
Tartrate Resistant Acid Phosphatase ◽  
Dependent Manner ◽  
Bone Homeostasis ◽  
Osteoblastic Cell Line ◽  
Anti Inflammatory

DNA methylation controls several inflammatory genes affecting bone homeostasis. Hitherto, inhibition of DNA methylation in vivo in the context of periodontitis and osteoclastogenesis has not been attempted. Ligature-induced periodontitis in C57BL/6J mice was induced by placing ligature for five days with Decitabine (5-aza-2′-deoxycytidine) (1 mg/kg/day) or vehicle treatment. We evaluated bone resorption, osteoclast differentiation by tartrate-resistant acid phosphatase (TRAP) and mRNA expression of anti-inflammatory molecules using cluster differentiation 14 positive (CD14+) monocytes from human peripheral blood. Our data showed that decitabine inhibited bone loss and osteoclast differentiation experimental periodontitis, and suppressed osteoclast CD14+ human monocytes; and conversely, that it increased bone mineralization in osteoblastic cell line MC3T3-E1 in a concentration-dependent manner. In addition to increasing IL10 (interleukin-10), TGFB (transforming growth factor beta-1) in CD14+ monocytes, decitabine upregulated KLF2 (Krüppel-like factor-2) expression. Overexpression of KLF2 protein enhanced the transcription of IL10 and TGFB. On the contrary, site-directed mutagenesis of KLF2 binding site in IL10 and TFGB abrogated luciferase activity in HEK293T cells. Decitabine reduces bone loss in a mouse model of periodontitis by inhibiting osteoclastogenesis through the upregulation of anti-inflammatory cytokines via KLF2 dependent mechanisms. DNA methyltransferase inhibitors merit further investigation as a possible novel therapy for periodontitis.

scholarly journals Kalkitoxin Reduces Osteoclast Formation and Resorption and Protects against Inflammatory Bone Loss

2021 ◽  
Vol 22 (5) ◽  
pp. 2303
Author(s):  
Liang Li ◽  
Ming Yang ◽  
Saroj Kumar Shrestha ◽  
Hyoungsu Kim ◽  
William H. Gerwick ◽  
...  
Keyword(s):  
Bone Loss ◽  
Transmembrane Protein ◽  
Osteoclast Differentiation ◽  
Mapk Signaling ◽  
Osteoclast Formation ◽  
Bone Diseases ◽  
Tartrate Resistant Acid Phosphatase ◽  
Nuclear Factor ◽  
Mineral Density ◽  
Multinucleated Cells

Osteoclasts, bone-specified multinucleated cells produced by monocyte/macrophage, are involved in numerous bone destructive diseases such as arthritis, osteoporosis, and inflammation-induced bone loss. The osteoclast differentiation mechanism suggests a possible strategy to treat bone diseases. In this regard, we recently examined the in vivo impact of kalkitoxin (KT), a marine product obtained from the marine cyanobacterium Moorena producens (previously Lyngbya majuscula), on the macrophage colony-stimulating factor (M-CSF) and on the receptor activator of nuclear factor κB ligand (RANKL)-stimulated in vitro osteoclastogenesis and inflammation-mediated bone loss. We have now examined the molecular mechanism of KT in greater detail. KT decreased RANKL-induced bone marrow-derived macrophages (BMMs) tartrate-resistant acid phosphatase (TRAP)-multinucleated cells at a late stage. Likewise, KT suppressed RANKL-induced pit area and actin ring formation in BMM cells. Additionally, KT inhibited several RANKL-induced genes such as cathepsin K, matrix metalloproteinase (MMP-9), TRAP, and dendritic cell-specific transmembrane protein (DC-STAMP). In line with these results, RANKL stimulated both genes and protein expression of c-Fos and nuclear factor of activated T cells (NFATc1), and this was also suppressed by KT. Moreover, KT markedly decreased RANKL-induced p-ERK1/2 and p-JNK pathways at different time points. As a result, KT prevented inflammatory bone loss in mice, such as bone mineral density (BMD) and osteoclast differentiation markers. These experiments demonstrated that KT markedly inhibited osteoclast formation and inflammatory bone loss through NFATc1 and mitogen-activated protein kinase (MAPK) signaling pathways. Therefore, KT may have potential as a treatment for destructive bone diseases.

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