• Title/Summary/Keyword: c-Fos

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Obatoclax Regulates the Proliferation and Fusion of Osteoclast Precursors through the Inhibition of ERK Activation by RANKL

  • Oh, Ju Hee;Lee, Jae Yoon;Park, Jin Hyeong;No, Jeong Hyeon;Lee, Na Kyung
    • Molecules and Cells
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    • v.38 no.3
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    • pp.279-284
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    • 2015
  • Obatoclax, a pan-Bcl2 inhibitor, shows antitumor activities in various solid malignancies. Bcl2-deficient mice have shown the importance of Bcl2 in osteoclasts, as the bone mass of the mice was increased by the induced apoptosis of osteoclasts. Despite the importance of Bcl2, the effects of obatoclax on the proliferation and differentiation of osteoclast precursors have not been studied extensively. Here, we describe the anti-proliferative effects of obatoclax on osteoclast precursors and its negative role on fusion of the cells. Stimulation with low doses of obatoclax significantly suppressed the proliferation of osteoclast precursors in a dose-dependent manner while the apoptosis was markedly increased. Its stimulation was sufficient to block the activation of ERK MAP kinase by RANKL. The same was true when PD98059, an ERK inhibitor, was administered to osteoclast precursors. The activation of JNK1/2 and p38 MAP kinase, necessary for osteoclast differentiation, by RANKL was not affected by obatoclax. Interestingly, whereas the number of TRAP-positive mononuclear cells was increased by both obatoclax and PD98059, fused, multinucleated cells larger than $100{\pm}m$ in diameter containing more than 20 nuclei were completely reduced. Consistently, obatoclax failed to regulate the expression of osteoclast marker genes, including c-Fos, TRAP, RANK and CtsK. Instead, the expression of DC-STAMP and Atp6v0d2, genes that regulate osteoclast fusion, by RANKL was significantly abrogated by both obatoclax and PD98059. Taken together, these results suggest that obatoclax down-regulates the proliferation and fusion of osteoclast precursors through the inhibition of the ERK1/2 MAP kinase pathway.

Analysis of MAPK Signaling Pathway Genes in the Intestinal Mucosal Layer of Necrotic Eenteritis-Afflicted Two Inbred Chicken Lines

  • Truong, Anh Duc;Hong, Yeojin;Lee, Janggeun;Lee, Kyungbaek;Lillehoj, Hyun S.;Hong, Yeong Ho
    • Korean Journal of Poultry Science
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    • v.44 no.3
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    • pp.199-209
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    • 2017
  • Mitogen-activated protein kinase (MAPK) signaling pathways play a key role in innate immunity, inflammation, cell proliferation, cell differentiation, and cell death. The main objective of this study was to investigate the expression level of candidate MAPK pathway genes in the intestinal mucosal layer of two genetically disparate chicken lines (Marek's disease-resistant line 6.3 and Marek's disease-susceptible line 7.2) induced with necrotic enteritis (NE). Using high-throughput RNA sequencing, we investigated 178 MAPK signaling pathway related genes that were significantly and differentially expressed between the intestinal mucosal layers of the NE-afflicted and control chickens. In total, 15 MAPK pathway genes were further measured by quantitative real-time PCR(qRT-PCR) and the results were consistent with the RNA-sequencing data. All 178 identified genes were annotated through Gene Ontology and mapped onto the KEGG chicken MAPK signaling pathway. Several key genes of the MAPK pathway, ERK1/2, JNK1-3, p38 MAPK, MAP2K1-4, $NF-{\kappa}B1/2$, c-Fos, AP-1, Jun-D, and Jun, were differentially expressed in the two chicken lines. Therefore, we believe that RNA sequencing and qRT-PCR analysis provide resourceful information for future studies on MAPK signaling of genetically disparate chicken lines in response to pathogens.

Effect of Water Extract of Eucommiae cortex In RANKL-induced Osteoclast Differentiation (두충의 물 추출물이 파골세포의 분화에 미치는 영향)

  • Jung, Yeon-Tae;Choi, Yun-Hong;Song, Jeong-Hoon;Lee, Chang-Hoon;Lee, Myeung-Su;Jang, Sung-Jo;Cho, Hae-Joong;Kwak, Han-Bok;Oh, Jae-Min
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.3
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    • pp.613-618
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    • 2009
  • Although the effect of Eucommie umoides oliver in osteoporosis has been studied, direct action of Eucommis ulmoides Oliver on osteoclasts remains unknown. Here we examined whether Eucommiae cortex inhibits osteoclast differentiation and bone resorption, a process known to be involved in bone diseases such as osteoporosis. Water extract from Eucommiae cortex (WE-EC) inhibited differentiation of bone marrow macrophages (BMMs) into osteoclasts without causing cytotoxicity. WE-EC suppressed the phosphorylation of p38, ERK, and JNK in BMMs treated with RANKL. WE EC specifically suppressed the mRNA expression of NFATc1 induced by RANKL. However, WE-EC inhibited stability of c-Fos protein induced by RANKL. Furthermore, WE-EC inhibited osteoclast survival induced by RANKL and in turn suppressed bone resorption. Taken together, our results suggest that WE-EC may be better agents for therapeutic use in bone diseases.

Poncirin Inhibits Osteoclast Differentiation and Bone Loss through Down-Regulation of NFATc1 In Vitro and In Vivo

  • Chun, Kwang-Hoon;Jin, Hyun Chul;Kang, Ki Sung;Chang, Tong-Shin;Hwang, Gwi Seo
    • Biomolecules & Therapeutics
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    • v.28 no.4
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    • pp.337-343
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    • 2020
  • Activation of osteoclast and inactivation of osteoblast result in loss of bone mass with bone resorption, leading to the pathological progression of osteoporosis. The receptor activator of NF-κB ligand (RANKL) is a member of the TNF superfamily, and is a key mediator of osteoclast differentiation. A flavanone glycoside isolated from the fruit of Poncirus trifoliata, poncirin has anti-allergic, hypocholesterolemic, anti-inflammatory and anti-platelet activities. The present study investigates the effect of poncirin on osteoclast differentiation of RANKL-stimulated RAW264.7 cells. We observed reduced formation of RANKL-stimulated TRAP-positive multinucleated cells (a morphological feature of osteoclasts) after poncirin exposure. Real-time qPCR analysis showed suppression of the RANKL-mediated induction of key osteoclastogenic molecules such as NFATc1, TRAP, c-Fos, MMP9 and cathepsin K after poncirin treatment. Poncirin also inhibited the RANKL-mediated activation of NF-κB and, notably, JNK, without changes in ERK and p38 expression in RAW264.7 cells. Furthermore, we assessed the in vivo efficacy of poncirin in the lipopolysaccharide (LPS)-induced bone erosion model. Evaluating the micro-CT of femurs revealed that bone erosion in poncirin treated mice was markedly attenuated. Our results indicate that poncirin exerts anti-osteoclastic effects in vitro and in vivo by suppressing osteoclast differentiation. We believe that poncirin is a promising candidate for inflammatory bone loss therapeutics.

The Inactivation of ERK1/2, p38 and NF-kB Is Involved in the Down-Regulation of Osteoclastogenesis and Function by A2B Adenosine Receptor Stimulation

  • Kim, Bo Hyun;Oh, Ju Hee;Lee, Na Kyung
    • Molecules and Cells
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    • v.40 no.10
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    • pp.752-760
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    • 2017
  • A2B adenosine receptor (A2BAR) is known to be the regulator of bone homeostasis, but its regulatory mechanisms in osteoclast formation are less well-defined. Here, we demonstrate the effect of A2BAR stimulation on osteoclast differentiation and activity by RANKL. A2BAR was expressed in bone marrow-derived monocyte/macrophage (BMM) and RANKL increased A2BAR expression during osteoclastogenesis. A2BAR stimulation with its specific agonist BAY 60-6583 was sufficient to inhibit the activation of ERK1/2, p38 MAP kinases and $NF-{\kappa}B$ by RANKL as well as it abrogated cell-cell fusion in the late stage of osteoclast differentiation. Stimulation of A2BAR suppressed the expression of osteoclast marker genes, such as c-Fos, TRAP, Cathepsin-K and NFATc1, induced by RANKL, and transcriptional activity of NFATc1 was also inhibited by stimulation of A2BAR. A2BAR stimulation caused a notable reduction in the expression of Atp6v0d2 and DC-STAMP related to cell-cell fusion of osteoclasts. Especially, a decrease in bone resorption activity through suppression of actin ring formation by A2BAR stimulation was observed. Taken together, these results suggest that A2BAR stimulation inhibits the activation of ERK1/2, p38 and $NF-{\kappa}B$ by RANKL, which suppresses the induction of osteoclast marker genes, thus contributing to the decrease in osteoclast cell-cell fusion and bone resorption activity.

The Stimulatory Effect of P2Y6 Receptor Antagonist on RANKL-induced Osteoclastogenesis (P2Y6 수용체 길항제의 파골세포 분화 촉진 효과 규명)

  • Noh, A Long Sae Mi;Moon, Miran;Yim, Mijung
    • YAKHAK HOEJI
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    • v.59 no.5
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    • pp.207-214
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    • 2015
  • P2Y receptors, a type of P2 receptor family, are G-protein coupled receptors and 8 subtypes have been characterized ($P2Y_1$, $P2Y_2$, $P2Y_4$, $P2Y_6$, $P2Y_{11-14}$). Recently, several studies have shed light on the role of P2Y receptors in bone biology. Among them, little is known on the role of $P2Y_6$ receptor on osteoclast differentiation. Thus, we investigated the role of $P2Y_6$ receptor on osteoclastogenesis using $P2Y_6$ receptor selective antagonist, MRS 2578. When osteoblasts and bone marrow cells were co-cultured in the presence of $VitD_3$ and $PGE_2$, $P2Y_6$ antagonist increased the formation of TRAP positive osteoclasts. To elucidate the target cells of $P2Y_6$ antagonist, we first checked the effect of MRS 2578 on osteoblasts. Treatment of MRS 2578 did not affect OPG : RANKL mRNA ratio in osteoblasts. Next, we checked the effects of $P2Y_6$ antagonist on osteoclast precursors using mouse bone marrow macrophages (BMMs). Addition of MRS 2578 increased the number of osteoclasts in RANKL-treated BMMs. Although $P2Y_6$ antagonist had no effect on RANKL-induced NFATc1, c-Fos and MafB expression levels, it significantly stimulated RANKL-induced Blimp1 mRNA expression in BMMs. Taken together, these data indicate that $P2Y_6$ antagonist increases osteoclast formation by upregulation of Blimp1 expression.

Inhibitory Effect of Deer Antler on Osteoclastic Bone Resorption (파골세포의 골 흡수에 미치는 녹용의 억제효과)

  • Kim, Yun-Kyung;Choi, Yun-Hong;Song, Jeong-Hoon;Jang, Sung-Jo;Kim, Hyun-Jung;Lee, Chang-Hoon;Ahn, Ho-Seon;Lee, Ji-Eun;Kim, Jeong-Joong;Choi, Min-Kyu
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.6
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    • pp.1299-1304
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    • 2009
  • We have previously shown that water extract of deer antler (WEDA) inhibited RANKL-mediated osteoclast differentiation from bone marrow macrophages by suppressing c-Fos and NFATc1 expression. Thus, we examined the effect of WEDA in inflammation-induced bone loss in vivo. Here we found that WEDA inhibited osteoblast-supported osteoclast differentiation induced by lipopolysaccharide (LPS). However, WEDA did not suppress the expression of receptor activator of NF-${\kappa}B$ ligand (RANKL) in response to LPS in osteoblasts. WEDA also inhibited the bone resorptive activity of mature osteoclasts. To examine the effect of WEDA on bone loss, when LPS injected subcutaneously in mice, bone loss was greatly increased, but WEDA treatment inhibited LPS-mediated bone loss. Taken together, we conclude that WEDA inhibited osteoclast differentiation and bone resorption in vitro and in vivo. Thus WEDA may be useful in the treatment of bone-related disorders.

Inhibition of Osteoclast Differentiation by Wheat Bran Butanol Fraction (밀기울 부탄올 분획물이 파골세포의 분화억제에 미치는 효과)

  • Moon, Jung Sun;Moon, Seung-Hee;Shim, Bo Won;Kang, Tae Jin;Lee, Sookyeon;Yim, Dongsool
    • Korean Journal of Pharmacognosy
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    • v.44 no.3
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    • pp.257-262
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    • 2013
  • Osteoporosis is a disease of bones that leads to an increased risk of fracture. In osteoporosis, the bone mineral density is reduced, bone microarchitecture deteriorates, and the amount and variety of proteins in bone are altered. $It^{\circ}{\emptyset}s$ caused by the imbalance between born resorption and born formation. Recently natural products from plants have been extensively studied as therapeutic drugs to treat and prevent various diseases. Wheat bran is the hard outer layers of wheat grain and produced as a by-product of milling in the production of refined grains. In oriental medicines, Bu So Maek (Tritici Immaturi Semen) with wheat bran has been used as bronchitis, sedatives and anti-sweating effects. However effects of wheat bran butanol fraction (WBB, 50 ${\mu}g/ml$) in osteoclast differentiation remains unknown yet. Thus we investigated the effects of WBB on RANKL induced osteoclast differentiation. WBB inhibited osteoclast differentiation by downregulating the RANKL-induced activations of MAP kinases. Moreover mRNA expression of osteoclast-mediating molecules such as c-Fos, NFATc1 and DC-STAMP were attenuated by WBB during osteoclast differentiation. The finding of this study show that WBB and its components might prevent osteoclast-related bone loss.

Effects of Fermented Rice Wine Using Mycelium of Phellinus linteus on the Gastric Mucosa of Rat (상황버섯 균사체를 이용한 발효주가 흰쥐의 위점막에 미치는 영향)

  • Lee Soo-Jin;Choi Yung-Hyun;Lee Yong-Tae;Chung Kyung-Tae;Jeong Young-Kee;Choi Byung-Tae
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.20 no.1
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    • pp.65-68
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    • 2006
  • It was examined the effect of fermented rice wine using mycelium of Phellinus linteus (FWPL) on the gastric mucosa of rat. The gastric mucosal lesions were not seen macroscopically in normal, but ethanol-administrated rats produced congestion and edema with a few local lesions. The administration of FWPL showed a similar pattern as like normal except trace histopathological changes. The results of Western blot analyses showed that the higher expression of inducible nitric oxygenase (iNOS), cyclooxygenase (COX)-1, COX-2, tumor necrosis factor-$\alpha$ and c-fos, especially COX-2, in the ethanol-administrated rat compared with normal rat. But FWPL-administrated rat showed a trace increase of these expression compared to normal rat. About immunohistochemical observations, weaker iNOS reactions were detected in mucous cells of epithelim of ethanol administrated rat compared with normal and FWPL-administrated rat. These results suggested that FWPL-administrated rat showed a trace changes on the mucus barrier-related protein expression compared with ethanol-administrated rat and thus FWPL may be use to develop a functional alcoholic beverage.

Rev-erbα Negatively Regulates Osteoclast and Osteoblast Differentiation through p38 MAPK Signaling Pathway

  • Kim, Kabsun;Kim, Jung Ha;Kim, Inyoung;Seong, Semun;Kim, Nacksung
    • Molecules and Cells
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    • v.43 no.1
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    • pp.34-47
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    • 2020
  • The circadian clock regulates various physiological processes, including bone metabolism. The nuclear receptors Reverbs, comprising Rev-erbα and Rev-erbβ, play a key role as transcriptional regulators of the circadian clock. In this study, we demonstrate that Rev-erbs negatively regulate differentiation of osteoclasts and osteoblasts. The knockdown of Rev-erbα in osteoclast precursor cells enhanced receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast formation, as well as expression of nuclear factor of activated T cells 1 (NFATc1), osteoclast-associated receptor (OSCAR), and tartrate-resistant acid phosphatase (TRAP). The overexpression of Rev-erbα leads to attenuation of the NFATc1 expression via inhibition of recruitment of c-Fos to the NFATc1 promoter. The overexpression of Rev-erbα in osteoblast precursors attenuated the expression of osteoblast marker genes including Runx2, alkaline phosphatase (ALP), bone sialoprotein (BSP), and osteocalcin (OC). Rev-erbα interfered with the recruitment of Runx2 to the promoter region of the target genes. Conversely, knockdown of Rev-erbα in the osteoblast precursors enhanced the osteoblast differentiation and function. In addition, Rev-erbα negatively regulated osteoclast and osteoblast differentiation by suppressing the p38 MAPK pathway. Furthermore, intraperitoneal administration of GSK4112, a Rev-erb agonist, protects RANKL-induced bone loss via inhibition of osteoclast differentiation in vivo. Taken together, our results demonstrate a molecular mechanism of Rev-erbs in the bone remodeling, and provide a molecular basis for a potential therapeutic target for treatment of bone disease characterized by excessive bone resorption.