scholarly journals Gamabufotalin Inhibits Osteoclastgenesis and Counteracts Estrogen-Deficient Bone Loss in Mice by Suppressing RANKL-Induced NF-κB and ERK/MAPK Pathways

2021 ◽  
Vol 12 ◽  
Author(s):  
Kaiqiang Sun ◽  
Jian Zhu ◽  
Yi Deng ◽  
Ximing Xu ◽  
Fanqi Kong ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Signaling Pathways ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Bone Homeostasis ◽  
Ample Evidence ◽  
Erk Mapk ◽  
Osteolytic Bone Disease

Osteolytic bone disease is a condition of imbalanced bone homeostasis, characterized mainly by excessive bone-resorptive activity, which could predispose these populations, such as the old and postmenopausal women, to developing high risk of skeletal fragility and fracture. The nature of bone homeostasis is the coordination between the osteoblasts (OBs) and osteoclasts (OCs). Abnormal activation of osteoclasts (OCs) could compromise the bone homeostasis, constantly followed by a clutch of osteolytic diseases, including postmenopausal osteoporosis, osteoarthritis, and rheumatoid arthritis. Thus, it is imperatively urgent to explore effective medical interventions for patients. The traditional Chinese medicine (TCM) gamabufotalin (CS-6) is a newly identified natural product from Chansu and has been utilized for oncologic therapies owing to its good clinical efficacy with less adverse events. Previous study suggested that CS-6 could be a novel anti-osteoporotic agent. Nevertheless, whether CS-6 suppresses RANK-(receptor activator of nuclear factor-κ B ligand)/TRAF6 (TNF receptor-associated factor 6)-mediated downstream signaling activation in OCs, as well as the effects of CS-6 on OC differentiation in vivo, remains elusive. Therefore, in this present study, we aimed to explore the biological effects of CS-6 on osteoclastogenesis and RANKL-induced activation of related signaling pathways, and further to examine the potential therapeutic application in estrogen-deficient bone loss in the mice model. The results of in vitro experiment showed that CS-6 can inhibit RANKL-induced OC formation and the ability of bone resorption in a dose-dependent manner at both the early and late stages of osteoclastogenesis. The gene expression of OC-related key genes such as tartrate-resistant acid phosphatase (TRAP), CTSK, DC-STAMP, MMP9, and β3 integrin was evidently reduced. In addition, CS-6 could mitigate the systemic estrogen-dependent bone loss and pro-inframammary cytokines in mice in vivo. The molecular mechanism analysis suggested that CS-6 can suppress RANKL/TRAF6-induced early activation of NF-κB and ERK/MAPK signaling pathways, which consequently suppressed the transcription activity of c-Fos and NFATc1. Taken together, this present study provided ample evidence that CS-6 has the promise to become a therapeutic candidate in treating osteolytic conditions mediated by elevated OC formation and bone resorption.

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 Inhibition effects of patchouli alcohol against influenza a virus through targeting cellular PI3K/Akt and ERK/MAPK signaling pathways

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Yunjia Yu ◽  
Yang Zhang ◽  
Shuyao Wang ◽  
Wei Liu ◽  
Cui Hao ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Influenza A ◽  
Plaque Assay ◽  
Mapk Signaling ◽  
Western Blot Assay ◽  
Patchouli Alcohol ◽  
Erk Mapk ◽  
Mapk Signaling Pathways

Abstract Background Patchouli alcohol (PA) is a tricyclic sesquiterpene extracted from Pogostemonis Herba, which is a traditional Chinese medicine used for therapy of inflammatory diseases. Recent studies have shown that PA has various pharmacological activities, including anti-bacterial and anti-viral effects. Methods In this study, the anti-influenza virus (IAV) activities and mechanisms were investigated both in vitro and in vivo. The inhibitory effects of PA against IAV in vitro were evaluated by plaque assay and immunofluorescence assay. The neuraminidase inhibition assay, hemagglutination inhibition (HI) assay, and western blot assay were used to explore the anti-viral mechanisms. The anti-IAV activities in vivo were determined by mice pneumonia model and HE staining. Results The results showed that PA significantly inhibited different IAV strains multiplication in vitro, and may block IAV infection through inactivating virus particles directly and interfering with some early stages after virus adsorption. Cellular PI3K/Akt and ERK/MAPK signaling pathways may be involved in the anti-IAV actions of PA. Intranasal administration of PA markedly improved mice survival and attenuated pneumonia symptoms in IAV infected mice, comparable to the effects of Oseltamivir. Conclusions Therefore, Patchouli alcohol has the potential to be developed into a novel anti-IAV agent in the future.

scholarly journals Nicorandil Inhibits Osteoclast Formation Base on NF-κB and p-38 MAPK Signaling Pathways and Relieves Ovariectomy-Induced Bone Loss

2021 ◽  
Vol 12 ◽  
Author(s):  
Shenggui Xu ◽  
Xiankun Cao ◽  
Zhenxing Yu ◽  
Wenxin He ◽  
Yichuan Pang ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Signaling Pathways ◽  
P38 Mapk ◽  
Biological Effects ◽  
Mapk Signaling ◽  
Osteoclast Formation ◽  
Mineral Density ◽  
Mapk Activation ◽  
Bone Disorders

Osteolytic bone disorders are characterized by an overall reduction in bone mineral density which enhances bone ductility and vulnerability to fractures. This disorder is primarily associated with superabundant osteoclast formation and bone resorption activity. Nicorandil (NIC) is a vasodilatory anti-anginal drug with ATP-dependent potassium (KATP) channel openings. However, NIC is adopted to manage adverse cardiovascular and coronary events. Recent research has demonstrated that NIC also possesses anti-inflammatory peculiarity through the regulation of p38 MAPK and NF-κB signaling pathways. Both MAPK and NF-κB signaling pathways play pivotal roles in RANKL-induced osteoclast formation and bone resorption function. Herein, we hypothesized that NIC may exert potential biological effects against osteoclasts, and revealed that NIC dose-dependently suppressed bone marrow macrophage (BMM) precursors to differentiate into TRAP + multinucleated osteoclasts in vitro. Furthermore, osteoclast resorption assays demonstrated anti-resorptive effects exhibited by NIC. NIC had no impact on osteoblast differentiation or mineralization function. Based on Biochemical analyses, NIC relieved RANKL-induced ERK, NF-κB and p38 MAPK signaling without noticeable effects on JNK MAPK activation. However, the attenuation of NF-κB and p38 MAPK activation was sufficient to hamper the downstream induction of c-Fos and NFATc1 expression. Meanwhile, NIC administration markedly protected mice from ovariectomy (OVX)-induced bone loss through in vivo inhibition of osteoclast formation and bone resorption activity. Collectively, this work demonstrated the potential of NIC in the management of osteolytic bone disorders mediated by osteoclasts.

scholarly journals Shikimic Acid Inhibits Osteoclastogenesis in Vivo and in Vitro by Blocking RANK/TRAF6 Association and Suppressing NF-κB and MAPK Signaling Pathways

2018 ◽  
Vol 51 (6) ◽  
pp. 2858-2871 ◽  
Author(s):  
Xiao Chen ◽  
Xiaoqun Li ◽  
Xiao Zhai ◽  
Xin Zhi ◽  
Liehu Cao ◽  
...  
Keyword(s):  
Bone Loss ◽  
Signaling Pathways ◽  
Shikimic Acid ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Bone Homeostasis ◽  
Actin Ring ◽  
Ovariectomized Mice

Background/Aims: Bone homeostasis is associated with the balance between bone-resorbing osteoclasts and bone-forming osteoblasts. Unbalanced bone homeostasis as a result of reduced osteogenesis or excessive osteoclastogenesis can lead to disorders such as osteoporosis, Paget’s disease, and rheumatoid arthritis. Shikimic acid is a cyclohexanecarboxylic acid, reported to exhibit pharmacological properties including anti-inflammatory and antioxidant activities. However, its effects on bone homeostasis remain unknown. Methods: First, the in vitro MTT cell viability assay was performed. Tartrate-resistant acid phosphatase (TRAP) and actin ring formation assays, as well as immunofluorescence staining were then performed to evaluate osteoclastogenesis. Potential signaling pathways were characterized by western blotting and verified in overexpression experiments. Related factors were examined by western blotting, reverse transcription polymerase chain reaction, electrophoretic mobility shift assay, and co-immunoprecipitation. Ovariectomized mice were used for the in vivo study. Results: TRAP staining showed that shikimic acid significantly inhibited osteoclastogenesis and pit resorption in bone marrow monocytes and RAW264.7 cells, and actin ring formation assays showed that shikimic acid suppressed the bone resorption function of osteoclasts. Furthermore, shikimic acid inhibited the receptor activator of nuclear factor-κB RANK/tumor necrosis factor receptor-associated factor 6 (TRAF6) association, suppressed nuclear factor-κB and mitogen-activated protein kinase signaling pathways, and downregulated nuclear factor of activated T-cell cytoplasmic 1. The expression of osteoclastogenesis biomarkers, including TRAF6, calcitonin receptor, TRAP, cathepsin K, and matrix metalloproteinase-9, was inhibited. In vivo, shikimic acid also significantly ameliorated bone loss and prevented osteoclastogenesis in ovariectomized mice. Conclusion: Shikimic acid inhibited osteoclastogenesis and osteoclast function by blocking RANK ligand-induced recruitment of TRAF6, as well as downstream signaling pathways in vitro. Shikimic acid also reduced ovariectomy-induced osteoclastogenesis and bone loss in vivo.

scholarly journals Tenofovir Modulates Semaphorin 4D Signaling and Regulates Bone Homeostasis, Which Can Be Counteracted by Dipyridamole and Adenosine A2A Receptor

2021 ◽  
Vol 22 (21) ◽  
pp. 11490
Author(s):  
Patricia Llamas-Granda ◽  
Laura Martin-Rodríguez ◽  
Raquel Largo ◽  
Gabriel Herrero-Beaumont ◽  
Aránzazu Mediero
Keyword(s):  
Bone Loss ◽  
Saline Control ◽  
Dependent Manner ◽  
Bone Homeostasis ◽  
Semaphorin 4D ◽  
Pre Treatment ◽  
And Function ◽  
Adenosine A2a

Semaphorin 4D (Sema4D) is a neurotrophin that is secreted by osteoclasts and binds to its receptor PlexinB1 on osteoblasts to inhibit their differentiation and function. Adenosine A2A activation inhibits osteoclast Sema4D-mediated secretion, diminishes inflammatory osteolysis and prevents bone loss following tenofovir (one of the most used antivirals in HIV). Therefore, tenofovir might activate Sema4D signaling to alter bone turnover. Female C57Bl/6/A2AKO mice were ovariectomized and treated with saline (control), tenofovir 75 mg/Kg/day, dipyridamole 25 mg/Kg/day or a combination for 5 weeks and long bones were prepared for histology. Primary murine-induced osteoclast/osteoblast were challenged with tenofovir/dipyridamole 1 μM each, and the expression of Sema4D/PlexinB1, RhoA/ROCK/IGF1R was studied by RT-PCR, Western blot and immunostaining. In vivo tenofovir showed an increased expression of Sema4D when compared to control mice, and dipyridamole reverted the expression in an A2A-dependent manner. In vitro, tenofovir increases Sema4D expression and secretion in osteoclast precursors, and pre-treatment with dipyridamole reverted this effect. pRhoA and ROCK1 activation were increased and IRS1/IGF1R expression was diminished by tenofovir in the Vav3/ARHGAP18 mechanism in osteoblast precursors and reverted by dipyridamole in an A2A-dependent manner. This suggests that tenofovir increases bone loss by activation of Sema4D/PlexinB1 signaling, which inhibits osteoblast differentiation. Agents that increase local adenosine concentrations, such as dipyridamole, might prevent bone loss following the inhibition of this pathway.

scholarly journals Erianin suppresses hepatocellular carcinoma cells through down-regulation of PI3K/AKT, p38 and ERK MAPK signaling pathways

2020 ◽  
Vol 40 (7) ◽  
Author(s):  
Liang Yang ◽  
Yue Hu ◽  
Guanbao Zhou ◽  
Qi Chen ◽  
Zhenshun Song
Keyword(s):  
Hepatocellular Carcinoma ◽  
Protein Kinase ◽  
Signaling Pathways ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Migration And Invasion ◽  
Tunel Staining ◽  
Dependent Manner ◽  
Erk Mapk ◽  
Mapk Signaling Pathways

Abstract Background: Hepatocellular carcinoma (HCC) is the dominant pathological type of primary liver cancer and no effective methods are available for its treatment. Erianin is a natural product extracted from Dendrobium, which possesses multiple pharmacological activities, including antioxidative and antitumor activity. Objective: To evaluate the anti-HCC activities of erianin and explore its underlying mechanism. Methods: MTT assay and Crystal Violet staining assay were used to select the non-toxic concentrations for the subsequent experiments. The colony formation assay and PCNA fluorescent staining were used to investigate the antiproliferative effects of erianin on human SMMC-7721 and HepG2 cells. Wound healing and transwell test were used to analyze cell migration and invasion. Caspase3 and Tunel staining were used to detect apoptosis. Western blot was used to examine the expression levels of proteins associated with invasion and key proteins in the phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt), p38 and ERK mitogen-activated protein kinase (MAPK) signaling pathways. Results: Erianin inhibited HCC cell proliferation in a dose-dependent manner. Decreased migration rate and invaded cells were observed with erianin supplement. The expression of invasion-associated proteins in the erianin group was also down-regulated. Besides, more apoptotic cells were observed after erianin treatment. For the molecular mechanism, erianin inhibited the phosphorylation of Akt, ERK and P38 in the PI3K/Akt and ERK/P38 pathway. Conclusion: We demonstrated, for the first time, that erianin inhibited the proliferation, migration, invasion and induced the apoptosis of HCC through PI3K/Akt, p38 and ERK MAPK signaling pathway, indicating that erianin is a promising agent for the HCC treatment.

scholarly journals Estrogen Decreases Cytoskeletal Organization by Forming an ERα/SHP2/c-Src Complex in Osteoclasts to Protect against Ovariectomy-Induced Bone Loss in Mice

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 619
Author(s):  
Hyun-Jung Park ◽  
Malihatosadat Gholam-Zadeh ◽  
Sun-Young Yoon ◽  
Jae-Hee Suh ◽  
Hye-Seon Choi
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Ring Formation ◽  
Tartrate Resistant Acid Phosphatase ◽  
Actin Ring ◽  
Collagen Crosslinks ◽  
Trap Staining ◽  
Src Activation

Loss of ovarian function is closely related to estrogen (E2) deficiency, which is responsible for increased osteoclast (OC) differentiation and activity. We aimed to investigate the action mechanism of E2 to decrease bone resorption in OCs to protect from ovariectomy (OVX)-induced bone loss in mice. In vivo, tartrate-resistant acid phosphatase (TRAP) staining in femur and serum carboxy-terminal collagen crosslinks-1 (CTX-1) were analyzed upon E2 injection after OVX in mice. In vitro, OCs were analyzed by TRAP staining, actin ring formation, carboxymethylation, determination of reactive oxygen species (ROS) level, and immunoprecipitation coupled with Western blot. In vivo and in vitro, E2 decreased OC size more dramatically than OC number and Methyl-piperidino-pyrazole hydrate dihydrochloride (MPPD), an estrogen receptor alpha (ERα) antagonist, augmented the OC size. ERα was found in plasma membranes and E2/ERα signaling affected receptor activator of nuclear factor κB ligand (RANKL)-induced actin ring formation by rapidly decreasing a proto-oncogene tyrosine-protein kinase, cellular sarcoma (c-Src) (Y416) phosphorylation in OCs. E2 exposure decreased physical interactions between NADPH oxidase 1 (NOX1) and the oxidized form of c-Src homology 2 (SH2)-containing protein tyrosine phosphatase 2 (SHP2), leading to higher levels of reduced SHP2. ERα formed a complex with the reduced form of SHP2 and c-Src to decrease c-Src activation upon E2 exposure, which blocked a signal for actin ring formation by decreased Vav guanine nucleotide exchange factor 3 (Vav3) (p–Y) and Ras-related C3 botulinum toxin substrate 1 (Rac1) (GTP) activation in OCs. E2/ERα signals consistently inhibited bone resorption in vitro. In conclusion, our study suggests that E2-binding to ERα forms a complex with SHP2/c-Src to attenuate c-Src activation that was induced upon RANKL stimulation in a non-genomic manner, resulting in an impaired actin ring formation and reducing bone resorption.

scholarly journals Inhibitory Effect of LGS and ODE Isolated from the Twigs of Syringa oblata subsp. dilatata on RANKL-Induced Osteoclastogenesis in Macrophage Cells

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1779
Author(s):  
Ga-Ram Kim ◽  
Eun-Nam Kim ◽  
Kyoung Jin Park ◽  
Ki Hyun Kim ◽  
Gil-Saeng Jeong
Keyword(s):  
Protein Kinase ◽  
Bone Resorption ◽  
Signaling Pathways ◽  
Natural Product ◽  
Osteoclast Differentiation ◽  
Bone Diseases ◽  
Pivotal Role ◽  
Nuclear Factor ◽  
Bone Homeostasis ◽  
Nuclear Factor Kappa

Osteoblasts and osteoclasts play a pivotal role in maintaining bone homeostasis, of which excessive bone resorption by osteoclasts can cause osteoporosis and various bone diseases. However, current osteoporosis treatments have many side effects, and research on new treatments that can replace these treatments is ongoing. Therefore, in this study, the roles of ligustroside (LGS) and oleoside dimethylester (ODE), a natural product-derived compound isolated from Syringa oblata subsp. dilatata as a novel, natural product-derived osteoporosis treatments were investigated. In the results of this study, LGS and ODE inhibited the differentiation of receptor activator of nuclear factor kappa-Β ligand (RANKL)-induced RAW264.7 cells into osteoclasts without cytotoxicity, and down-regulated the activity of TRAP, a specific biomarker of osteoclasts. In addition, it inhibited bone resorption and actin ring formation, which are important functions and features of osteoclasts. Also, the effects of LGS and ODE on the mitogen-activated protein kinase (MAPK) and nuclear factor kappa-light-chain-enhancer of activated B (NF-κB) and phosphoinositide 3-kinases (PI3K)/ protein kinase B (Akt)/mechanistic target of rapamycin (mTOR) signaling pathways that play important roles in osteoclast differentiation were evaluated. In the results, LGS and ODE downregulated the phosphorylation of RANKL-induced MAPK and PI3K/Akt/mTOR proteins in a concentration-dependent manner, translocation of NF-κB into the nucleus was inhibited. As a result, the compounds LGS and ODE isolated from S. oblate subsp. dilatata effectively regulated the differentiation of RANKL-induced osteoclasts and inhibited the phosphorylation of signaling pathways that play a pivotal role in osteoclast differentiation. Therefore, these results suggest the possibility of LGS and ODE as new natural product treatments for bone diseases caused by excessive osteoclasts.

Candida tropicalis induces pro-inflammatory cytokine production, NF-κB and MAPKs pathways regulation, and dectin-1 activation

2018 ◽  
Vol 64 (12) ◽  
pp. 937-944 ◽  
Author(s):  
Zhimin Duan ◽  
Qing Chen ◽  
Rong Zeng ◽  
Leilei Du ◽  
Caixia Liu ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Inflammatory Cytokine ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Peripheral Blood Mononuclear ◽  
Downstream Signaling ◽  
Tnf Α ◽  
Mitogen Activated Protein

The prevalence of Candida infection induced by non-albicans Candida (NAC) species is increasing. However, as a common NAC species, C. tropicalis has received much less study in terms of host immunity than C. albicans has. In this study, we evaluated the pro-inflammatory cytokine responses evoked by C. tropicalis and determined whether dectin-1 and downstream NF-κB and mitogen-activated protein kinases (MAPKs) signaling pathways played roles in inflammation in human peripheral blood mononuclear cells (PBMCs) and THP-1 macrophage-like cells. Exposure of PBMCs and THP-1 macrophage-like cells to C. tropicalis led to the enhanced gene expression and secretion of TNF-α and IL-6 in a time- and dose-dependent manner. THP-1 macrophage-like cells being challenged by C. tropicalis resulted in the activation of the NF-κB, p38, and ERK1/2 MAPK signaling pathways. We also found that the expression of dectin-1 was increased with C. tropicalis treatment. These data reveal that dectin-1 may play a role in sensing the inflammation response induced by C. tropicalis and that NF-κB and MAPK are involved in the downstream signaling pathways in macrophages.

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