• Title/Summary/Keyword: Ligand Effects

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The Effect of overcoming the TRAIL resistance through bufalin in EJ human bladder cancer cell (EJ 인간 방광암 세포에서 bufalin 의 TRAIL 저항성 극복 효과)

  • Hong, Su Hyun
    • Herbal Formula Science
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    • v.25 no.2
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    • pp.145-154
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    • 2017
  • Objectives : Bufalin is one of the bioactive component of 'Sum Su (蟾酥)', which is obtained from the skin and parotid venom gland of toad. Bufalin has been known to possess the inhibitory effects on cell proliferation and inducing apoptosis in various cancer cells. The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) has concerned, because it can selectively induce apoptotic cell death in many types of malignant cells, while it is relatively non-toxic to normal cells. Here, we investigated whether bufalin can trigger TRAIL-induced apoptotic cell death in EJ human bladder cancer cells. Methods : Effects on the cell viability and apoptotic activity were quantified using MTT assay and flow cytometry analysis, respectively. To investigate the morphological change of nucleus, DAPI staining was performed. Protein expressions were measured by immunoblotting. Results : A combined treatment with bufalin (10 nM) and TRAIL (50 ng/ml) significantly promoted TRAIL-mediated growth inhibition and apoptosis in EJ cells. The apoptotic effects were associated with the up-regulation of death receptor proteins, and the down-regulation of cFLIP and XIAP. Moreover, our data showed that bufalin and TRAIL combination activated caspases and subsequently increased degradation of poly(ADP-ribose) polymerase. Conclusions : Taken altogether, the nontoxic doses of bufalin sensitized TRAIL-mediated apoptosis in EJ cells. Therefore, bufalin might be an effective therapeutic strategy for the safe treatment of TRAIL-resistant bladder cancers.

Inhibitory Effects on Bone Resorption and osteoblast proliferation of Kyungok-go (경옥고와 경옥고가연자육의 조골세포 증식과 골흡수 억제효과)

  • Kim, Ju-Ho;Lee, Jung-Ho;Oh, Jae-Min;Kim, Yun-Kyung
    • Herbal Formula Science
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    • v.19 no.2
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    • pp.61-71
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    • 2011
  • Objectives : Kyungok-go(KOG), the first herbal formulation of donguibogam, has been used for treating of many symptoms of yin deficiency. In this study, we examined the effect of KOG on bone resorption. Methods : We determined the effects of water extract of KOG in RANKL(Receptor Activator for Nuclear Factor ${\kappa}B$ Ligand)-induced osteoclast differentiation culture system and osteoblast proliferation. In addition, we determined the effects of water extract of ABR on LPS-induced bone-loss with mice. Results : Water extract of KOG showed proliferation effect on osteoblast without cytotoxicity and no effect on RANKL-treated osteoclast differentiation. KOG rescued bone erosion by LPS induction in vivo study. Conclusions : These results demonstrated that KOG can be a useful remedy for treating of bone-loss disease such as osteoporosis.

Inhibitory Effects of Artemisia asiatica on Osteoclast Formation Induced by Periodontopathogens

  • Moon, Sun-Young;Choi, Bong-Kyu;Cha, Jeong-Heon;Min, Chon-Ki;Son, Mi-Won;Yoo, Yun-Jung
    • Food Science and Biotechnology
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    • v.14 no.1
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    • pp.94-98
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    • 2005
  • Bone resorption surrounding tooth root causes tooth loss in periodontitis patients. Osteoclast has bone resorption activity. Effects of Artemisia asiatica on bone resorption induced by periodontopathogens, Porphyromonas gingivalis and Treponema denticola, were examined using co-culture systems of mouse osteoblasts and bone marrow cells. Addition of A. asiatica ethanol extract to bacterial sonicate abolished bacteria-induced osteoclastogenesis. To determine inhibitory mechanism of A. asiatica against osteoclastogenesis, effects of A. asiatica on expressions of osteoclastogenesis-inducing factors such as receptor activator of NF-${\kappa}B$ ligand (RANKL), prostaglandin $E_2\;(PGE_2)$, interleukin (IL)-1, and tumor necrosis factor (TNF)-${\alpha}$, in osteoblasts were examined. A. asiatica suppressed expressions of RANKL, $PGE_2$, IL-$1{\beta}$, and TNF-${\alpha}$ increased by each bacterial sonicate. These results suggest inhibitory action of A. asiatica against osteoclastogenesis is associated with down-regulations of RANKL, $PGE_2$ IL-$1{\beta}$, and TNF-${\alpha}$ expressions.

Inhibitory Effects of Curcuma xanthorrhiza Supercritical Extract and Xanthorrhizol on LPS-Induced Inflammation in HGF-1 Cells and RANKL-Induced Osteoclastogenesis in RAW264.7 Cells

  • Kim, Siyeon;Kook, Kyo Eun;Kim, Changhee;Hwang, Jae-Kwan
    • Journal of Microbiology and Biotechnology
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    • v.28 no.8
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    • pp.1270-1281
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    • 2018
  • Periodontal disease is triggered by the host immune response to pathogens in the microbial biofilm. Worsening of periodontal disease destroys the tooth-supporting tissues and alveolar bone. As oral inflammation can induce systemic diseases in humans, it is important to prevent periodontal disease. In this study, we demonstrated that Curcuma xanthorrhiza supercritical extract (CXS) and its active compound, xanthorrhizol (XAN), exhibit anti-inflammatory effects on lipopolysaccharide (LPS)-treated human gingival fibroblast-1 cells and anti-osteoclastic effects on receptor activator of nuclear factor kappa B ligand (RANKL)-treated RAW264.7 cells. LPS-upregulated inflammatory factors, such as nuclear factor kappa B p65 and $interleukin-1{\beta}$, were prominently reduced by CXS and XAN. In addition, RANKL-induced osteoclastic factors, such as nuclear factor of activated T-cells c1, tartrate-resistant acid phosphatase, and cathepsin K, were decreased in the presence of CXS and XAN. CXS and XAN inhibited the mitogen-activated protein kinase (MAPK)/activator protein-1 (AP-1) signaling pathway. Collectively, these results provide evidence that CXS and XAN suppress LPS-induced inflammation and RANKL-induced osteoclastogenesis by suppressing the MAPK/AP-1 pathway.

Anti-osteoporotic Effects of Unripe Fructus of Rubus coreanus Miquel in Osteoblastic and Osteoclastic Cells

  • Kim, Hyo Jin;Sim, Dong-Soo;Sohn, Eun-Hwa
    • Korean Journal of Plant Resources
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    • v.27 no.6
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    • pp.593-600
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    • 2014
  • Osteoporosis is a progressive bone disease characterized by low bone mass which is caused by disturbance in the balance between the activities of osteoblasts and osteoclasts. Postmenopausal osteoporosis is one of the most common disorders in women after menopause, which is linked to an estrogen deficiency and characterized by an excessive loss of trabecular bone. Rubus coreanus has been used for their various pharmacological properties in Asia as a traditional medicine. To investigate the effect of unripe fruits of R. coreanus 30% ethanol extract (RCE) on osteoblast-like cells (MG63) differentiation, we examined the effects of RCE on in vitro osteoblastic differentiation markers, alkaline phosphatase (ALP) activity and receptor activator of nuclear factor ${\kappa}$-B ligand (RANKL) and osteoprotegerin (OPG) expression. The high concentration (50 and $100{\mu}g/mL$) of RCE markedly increased ALP activity, whereas decreased the RANKL/OPG. We also investigated the effect of RCE on M-CSF plus RANKL-induced differentiation of pre-osteoclast cells (RAW 264.7). RCE treatment remarkably inhibited M-CSF/RANKL-induced formation of osteoclast-like multinuclear cells from RAW 264.7 cells. Moreover, the inhibitory effect of RCE was reduced by selective estrogen receptor-${\alpha}$ antagonist. Our research suggests that suggested that unripe fruits of R. coreanus may act beneficial effects on bone mass by regulating both osteoblast and osteoclast.

The Molecular Mechanism of Baicalin on RANKL-induced Osteoclastogenesis in RAW264.7 Cells

  • Ko, Seon-Yle
    • International Journal of Oral Biology
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    • v.38 no.2
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    • pp.67-72
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    • 2013
  • This study examined the anti-osteoclastogenic effects of baicalin on receptor activator of NF-${\kappa}$B ligand (RANKL)-induced RAW264.7 cells. Baicalin is a flavonoid that is produced by Scutellaria baicalensis and is known to have multiple biological properties, including antibacterial, anti-inflammatory and analgesic effects. The effects of baicalin on osteoclasts were examined by measuring 1) cell viability; 2) the formation of tartrate-resistant acid phosphatase (TRAP) (+) multinucleated cells; 3) RANK/RANKL signaling pathways and 4) mRNA levels of osteoclast-associated genes. Baicalin inhibited the formation of RANKL-stimulated TRAP (+) multinucleated cells and also suppressed the RANKL-stimulated activation of p-38, ERK, cSrc and AKT signaling. Baicalin also inhibited the RANKL-stimulated degradation of $I{\kappa}B$ in RAW264.7 cells. In addition, the RANKL-stimulated induction of NFATc1 transcription factors was found to be abrogated by this flavonoid. Baicalin was further found to decrease the mRNA expression of osteoclast-associated genes, including carbonic anhydrase II, TRAP and cathepsin K in the RAW264.7 cells. Our data thus demonstrate that baicalin inhibits osteoclastogenesis by inhibiting the RANKL-induced activation of signaling molecules and transcription factors in osteoclast precursors.

Piperlongumine suppressed osteoclastogenesis in RAW264.7 macrophages

  • Jin, Sun-Mi;Kang, Hae-Mi;Park, Dan-Bi;Yu, Su-Bin;Kim, In-Ryoung;Park, Bong-Soo
    • International Journal of Oral Biology
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    • v.44 no.3
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    • pp.89-95
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    • 2019
  • Piperlongumine (PL) is a natural product found in long pepper (Piper longum). The pharmacological effects of PL are well known, and it has been used for pain, hepatoprotection, and asthma in Oriental medicine. No studies have examined the effects of PL on bone tissue or bone-related diseases, including osteoporosis. The current study investigated for the first time the inhibitory effects of PL on osteoclast differentiation, bone resorption, and osteoclastogenesis-related factors in RAW264.7 macrophages stimulated by the receptor activator for nuclear factor-${\kappa}B$ ligand (RANKL). Cytotoxicity was examined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and osteoclast differentiation and bone resorption were confirmed by tartrate-resistant acid phosphatase (TRAP) staining and pit formation analysis. Osteoclast differentiation factors were confirmed by western blotting. PL exhibited toxicity in RAW264.7 macrophages, inhibiting osteoclast formation and bone resorption, in addition to inhibiting the expression of osteoclastogenesis-related factors, such as tumor necrosis factor receptor-associated factor 6 (TRAF6), c-Fos, and NFATc1, in RANKL-stimulated RAW264.7 macrophages. These findings suggest that PL is suitable for the treatment of osteoporosis, and it serves as a potential therapeutic agent for various bone diseases.

Adsorption of Metal Ions on Synthetic Resin with Styrene Hazardous Materials in Water Fire Extinguishing Agent (물 소화약제에서 스타이렌 위험물을 포함한 합성수지에 의한 금속 이온들의 흡착)

  • Lee, Chi-Young;Kim, Joon-Tae
    • Applied Chemistry for Engineering
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    • v.21 no.2
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    • pp.142-147
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    • 2010
  • Cryptand resins have been synthesized from 1-aza-18-crown-6 macrocyclic ligand attached to styrene (2th petroleum in 4th class hazardous materials) divinylbenzene copolymer with crosslinkage of 1%, 2%, 10%, and 18% by substitution reaction. The synthesis of these resins was confirmed by the content of chlorine, element analysis, surface area (BET), and IR-spectroscopy. The effects of pH, time and crosslinkage on adsorption of metal ion from water fire extinguishing agentby synthetic resin adsorbent were investigated. Metal ions showed a great adsorption over pH 3 and adsorption equilibriumof metal ions was about two hours. The adsorption selectivity determined in water was in the increasing order of sodium ($Na^{1+}$) > zinc ($Zn^{2+}$) > chromium ($Cr^{3+}$) ion. The adsorption was in the order of 1%, 2%, 10%, and 18% crosslinkage resin.

Expression and Function of TLR2 on CD4 Versus CD8 T Cells

  • Lee, Sun-Mi;Joo, Young-Don;Seo, Su-Kil
    • IMMUNE NETWORK
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    • v.9 no.4
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    • pp.127-132
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    • 2009
  • Background: Toll-like receptors (TLRs) play a fundamental role in innate immunity through their capacity to recognize pathogen-associated molecular patterns. Also, TLRs that are expressed in T cells are reported to function as co-stimulatory receptors. However, the functional capacity of TLRs on CD4 T and CD8 T cells has not been directly compared. Here we compared CD4 and CD8 T cell responses to TLR2 ligand plus TCR-mediated stimulation. Methods: TLR2 expression was analyzed on T cell subsets under naive and alloantigen-primed conditions. We analyzed the effects of TLR2 co-stimulation on proliferation and survival of T cell subsets in vitro when stimulated with soluble anti-CD3 in the presence or absence of synthetic ligand $Pam_3CSK_4$. Results: TLR2 expression on CD8 T cells was induced following activation; this expression was much higher than on CD4 T cells. Thus, the molecule was constitutively expressed on Listeriaspecific memory CD8 T cells. Based on these expression levels, proliferation and survival were markedly elevated in CD8 T cells in response to the TLR2 co-stimulation by $Pam_3CSK_4$ compared with those in CD4 T cells. Conclusion: Our data show that TLR2 co-stimulation is more responsible for proliferation and survival of CD8 T cells than for that of CD4 T cells.

Expression of Gas6 Receptors, Tyro3, Axl, and Mertk, in Oocytes and Embryos and Effects of Mertk RNAi on the Oocyte Maturation

  • Kim, Kyeoung-Hwa;Lee, Sang-Eun;Lee, Kyung-Ah
    • Development and Reproduction
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    • v.16 no.3
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    • pp.195-204
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    • 2012
  • Recently, we reported growth arrest-specific gene 6 (Gas6) as a new maternal effect gene (MEG), that expressed in the oocytes but functioned principally during embryogenesis. Gas6 RNAi-treated oocytes developed to metaphase II (MII) stage but they have affected M-phase promoting factor (MPF) activity and incurred abnormal pronuclear (PN) formation during fertilization. Gas6 is a ligand of TAM family members (Tyro3, Axl and Mertk) of receptor tyrosine kinase (RTK). Purpose of the present study was to evaluate the expression of Tyro3, Axl and Mertk transcripts in oocytes and early embryos. Expression of Gas6 and Mertk mRNA was detectable in oocytes and follicular cells, while Tyro3 and Axl mRNA was expressed only in follicular cells. Expression of Mertk mRNA was relatively constant during oocytes maturation and embryogenesis, but the other receptors, Tyro3 and Axl, were not expressed in oocytes and PN stage of embryos at all. Knockdown of Mertk mRNA and protein by using sequence-specific Mertk double strand RNA (dsRNA) did not affect oocytes maturation. In this case, however, contrary to the ligand Gas6 RNA interference (RNAi), MPF activity had not been changed by Mertk RNAi. Therefore, we concluded that the Gas6-Mertk signaling is not directly related to the oocyte maturation. It is still required to study further regarding the function of Mertk as the receptor of Gas6 during preimplantational early embryogenesis.