• Title/Summary/Keyword: Transcriptional activation

Search Result 373, Processing Time 0.028 seconds

Aster saponin A2 inhibits osteoclastogenesis through mitogen-activated protein kinase-c-Fos-NFATc1 signaling pathway

  • Su, Xiang-Dong;Yang, Seo Y;Shrestha, Saroj K;Soh, Yunjo
    • Journal of Veterinary Science
    • /
    • v.23 no.4
    • /
    • pp.47.1-47.11
    • /
    • 2022
  • Background: In lipopolysaccharide-induced RAW264.7 cells, Aster tataricus (AT) inhibits the nuclear factor kappa-light-chain-enhancer of activated B cells and MAPKs pathways and critical pathways of osteoclast development and bone resorption. Objectives: This study examined how aster saponin A2 (AS-A2) isolated from AT affects the processes and function of osteoclastogenesis induced by receptor activator of nuclear factor kappa-B ligand (RANKL) in RAW264.7 cells and bone marrow macrophages (BMMs). Methods: The cell viability, tartrate-resistant acid phosphatase staining, pit formation assay, polymerase chain reaction, and western blot were carried out to determine the effects of AS-A2 on osteoclastogenesis. Results: In RAW264.7 and BMMs, AS-A2 decreased RANKL-initiated osteoclast differentiation in a concentration-dependent manner. In AS-A2-treated cells, the phosphorylation of ERK1/2, JNK, and p38 protein expression were reduced considerably compared to the control cells. In RAW264.7 cells, AS-A2 suppressed the RANKL-induced activation of osteoclast-related genes. During osteoclast differentiation, AS-A2 suppressed the transcriptional and translational expression of NFATc1 and c-Fos. AS-A2 inhibited osteoclast development, reducing the size of the bone resorption pit area. Conclusion: AS-A2 isolated from AT appears to be a viable therapeutic therapy for osteolytic illnesses, such as osteoporosis, Paget's disease, and osteogenesis imperfecta.

Ahnak depletion accelerates liver regeneration by modulating the TGF-β/Smad signaling pathway

  • Yang, Insook;Son, Yeri;Shin, Jae Hoon;Kim, Il Yong;Seong, Je Kyung
    • BMB Reports
    • /
    • v.55 no.8
    • /
    • pp.401-406
    • /
    • 2022
  • Ahnak, a large protein first identified as an inhibitor of TGF-β signaling in human neuroblastoma, was recently shown to promote TGF-β in some cancers. The TGF-β signaling pathway regulates cell growth, various biological functions, and cancer growth and metastasis. In this study, we used Ahnak knockout (KO) mice that underwent a 70% partial hepatectomy (PH) to investigate the function of Ahnak in TGF-β signaling during liver regeneration. At the indicated time points after PH, we analyzed the mRNA and protein expression of the TGF -β/Smad signaling pathway and cell cycle-related factors, evaluated the cell cycle through proliferating cell nuclear antigen (PCNA) immunostaining, analyzed the mitotic index by hematoxylin and eosin staining. We also measured the ratio of liver tissue weight to body weight. Activation of TGF-β signaling was confirmed by analyzing the levels of phospho-Smad 2 and 3 in the liver at the indicated time points after PH and was lower in Ahnak KO mice than in WT mice. The expression levels of cyclin B1, D1, and E1; proteins in the Rb/E2F transcriptional pathway, which regulates the cell cycle; and the numbers of PCNA-positive cells were increased in Ahnak KO mice and showed tendencies opposite that of TGF-β expression. During postoperative regeneration, the liver weight to body weight ratio tended to increase faster in Ahnak KO mice. However, 7 days after PH, both groups of mice showed similar rates of regeneration, following which their active regeneration stopped. Analysis of hepatocytes undergoing mitosis showed that there were more mitotic cells in Ahnak KO mice, consistent with the weight ratio. Our findings suggest that Ahnak enhances TGF-β signaling during postoperative liver regeneration, resulting in cell cycle disruption; this highlights a novel role of Ahnak in liver regeneration. These results provide new insight into liver regeneration and potential treatment targets for liver diseases that require surgical treatment.

Transcriptional Regulatory Role of NELL2 in Preproenkephalin Gene Expression

  • Ha, Chang Man;Kim, Dong Hee;Lee, Tae Hwan;Kim, Han Rae;Choi, Jungil;Kim, Yoonju;Kang, Dasol;Park, Jeong Woo;Ojeda, Sergio R.;Jeong, Jin Kwon;Lee, Byung Ju
    • Molecules and Cells
    • /
    • v.45 no.8
    • /
    • pp.537-549
    • /
    • 2022
  • Preproenkephalin (PPE) is a precursor molecule for multiple endogenous opioid peptides Leu-enkephalin (ENK) and Met-ENK, which are involved in a wide variety of modulatory functions in the nervous system. Despite the functional importance of ENK in the brain, the effect of brain-derived factor(s) on PPE expression is unknown. We report the dual effect of neural epidermal growth factor (EGF)-like-like 2 (NELL2) on PPE gene expression. In cultured NIH3T3 cells, transfection of NELL2 expression vectors induced an inhibition of PPE transcription intracellularly, in parallel with downregulation of protein kinase C signaling pathways and extracellular signal-regulated kinase. Interestingly, these phenomena were reversed when synthetic NELL2 was administered extracellularly. The in vivo disruption of NELL2 synthesis resulted in an increase in PPE mRNA level in the rat brain, suggesting that the inhibitory action of intracellular NELL2 predominates the activation effect of extracellular NELL2 on PPE gene expression in the brain. Biochemical and molecular studies with mutant NELL2 structures further demonstrated the critical role of EGF-like repeat domains in NELL2 for regulation of PPE transcription. These are the first results to reveal the spatio-specific role of NELL2 in the homeostatic regulation of PPE gene expression.

Porcine parvovirus nonstructural protein NS1 activates NF-κB and it involves TLR2 signaling pathway

  • Jin, Xiaohui;Yuan, Yixin;Zhang, Chi;Zhou, Yong;Song, Yue;Wei, Zhanyong;Zhang, Gaiping
    • Journal of Veterinary Science
    • /
    • v.21 no.3
    • /
    • pp.50.1-50.16
    • /
    • 2020
  • Background: Porcine parvovirus (PPV) is a single-stranded DNA virus that causes porcine reproductive failure. It is of critical importance to study PPV pathogenesis for the prevention and control of the disease. NS1, a PPV non-structural protein, is participated in viral DNA replication, transcriptional regulation, and cytotoxicity. Our previous research showed that PPV can activate nuclear factor kappa B (NF-κB) signaling pathway and then up-regulate the expression of interleukin (IL)-6. Objectives: Herein, the purpose of this study is to determine whether the non-structural protein NS1 of PPV also has the same function. Methods: Real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR), enzyme-linked immunosorbent assay, western blot, immunofluorescence assay and small interfering RNA (siRNA) were used. Results: Our findings demonstrated that PPV NS1 protein can up-regulate the expression levels of IL-6 and tumor necrosis factor-alpha in a dose-dependent manner. Moreover, PPV NS1 protein was found to induce the phosphorylation of IκBα, then leading to the phosphorylation and nuclear translocation of NF-κB. In addition, the NS1 protein activated the upstream pathways of NF-κB. Meanwhile, TLR2-siRNA assay showed TLR2 plays an important role in the activation of NF-κB signaling pathway induced by PPV-NS1. Conclusions: These findings indicated that PPV NS1 protein induced the up-regulated of IL-6 expression through activating the TLR2 and NF-κB signaling pathways. In conclusion, these findings provide a new avenue to study the innate immune mechanism of PPV infection.

Oxymatrine inhibits the pyroptosis in rat insulinoma cells by affecting nuclear factor kappa B and nuclear factor (erythroid-derived 2)-like 2 protein/heme oxygenase-1 pathways

  • Gao, Jingying;Xia, Lixia;Wei, Yuanyuan
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.26 no.3
    • /
    • pp.165-174
    • /
    • 2022
  • As the mechanism underlying glucose metabolism regulation by oxymatrine is unclear, this study investigated the effects of oxymatrine on pyroptosis in INS-1 cells. Flow cytometry was employed to examine cell pyroptosis and reactive oxygen species (ROS) production. Cell pyroptosis was also investigated via transmission electron microscopy and lactate dehydrogenase (LDH) release. Protein levels were detected using western blotting and interleukin (IL)-1β and IL-18 secretion by enzyme-linked immunosorbent assay. The caspase-1 activity and DNA-binding activity of nuclear factor kappa B (NF-κB) and nuclear factor (erythroid-derived 2)-like 2 protein (Nrf2) were also assessed. In the high glucose and high fat-treated INS-1 cells (HG + PA), the caspase-1 activity and LDH content, as well as Nod-like receptor family pyrin domain containing 3, Gsdmd-N, caspase-1, apoptosis-associated speck-like protein containing a CARD, IL-1β, and IL-18 levels were increased. Moreover, P65 protein levels increased in the nucleus but decreased in the cytoplasm. Oxymatrine attenuated these effects and suppressed high glucose and high fat-induced ROS production. The increased levels of nuclear Nrf2 and heme oxygenase-1 (HO-1) in the HG + PA cells were further elevated after oxymatrine treatment, whereas cytoplasmic Nrf2 and Keleh-like ECH-associated protein levels decreased. Additionally, the elevated transcriptional activity of p65 in HG + PA cells was reduced by oxymatrine, whereas that of Nrf2 increased. The results indicate that the inhibition of pyroptosis in INS-1 cells by oxymatrine, a key factor in its glucose metabolism regulation, involves the suppression of the NF-κB pathway and activation of the Nrf2/HO-1 pathway.

The Anti-Inflammatory Effects of Bee Venom in Monosodium Urate Crystal-Induced THP-1 Cells

  • Sang-Yeup Chae;Dongmin Lee;Min-Jung Ko;Seungeun Lee;Jaeho Song;Jinkyung Park;Sinwoo Park;Yeon-Cheol Park;Foo Young Cho
    • Journal of Acupuncture Research
    • /
    • v.40 no.4
    • /
    • pp.368-376
    • /
    • 2023
  • Background: Although bee venom (BV) has clinical benefits in osteoarthritis and rheumatoid arthritis, it has not been tested as treatment for gouty arthritis. Moreover, in vitro, BV has been proven to exhibit anti-inflammatory and positive effects on osteoarthritis, but only limited evidence can confirm its beneficial effects on gout. Thus, this study aims to assess the anti-inflammatory effects of BV on monosodium urate (MSU)-induced THP-1 monocytes. Methods: THP-1 monocytes were differentiated into mature macrophages using phorbol 12-myristate 13-acetate (PMA) and pretreated for 6 hours with BV and a Caspase-1 inhibitor in a physiologically achievable range of concentrations (BV, 0.1-1 ㎍/mL; Caspase-1 inhibitor, 1-10 μM), followed by MSU crystal stimulation for 24 hours. The secretions of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), IL-6, IL-8, cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), and nitric oxide (NO) were increased in the MSU crystal-stimulated THP-1 cells. Results: Caspase-1 inhibitors suppressed the production of all mediators in a dose-dependent manner. BV worked on equal terms with Caspase-1 inhibitors and showed more satisfactory effects on TNF-α, PGE2, COX-2, and inducible nitric oxide synthase (iNOS). Moreover, the western blot analysis revealed that BV regulated the transcriptional levels of these mediators via the suppression of extracellular signal-regulated kinase (ERK) pathway activation. Conclusion: The results of the present study clearly suggest that BV inhibits MSU-induced inflammation in vitro, suggesting a possible role for BV in gout treatment.

Genetic Organization of the hrp Genes Cluster in Erwinia pyrifoliae and Characterization of HR Active Domains in HrpNEp Protein by Mutational Analysis

  • Shrestha, Rosemary;Park, Duck Hwan;Cho, Jun Mo;Cho, Saeyoull;Wilson, Calum;Hwang, Ingyu;Hur, Jang Hyun;Lim, Chun Keun
    • Molecules and Cells
    • /
    • v.25 no.1
    • /
    • pp.30-42
    • /
    • 2008
  • The disease-specific (dsp) region and the hypersensitive response and pathogenicity (hrp) genes, including the hrpW, $hrpN_{Ep}$, and hrpC operons have previously been sequenced in Erwinia pyrifoliae WT3 [Shrestha et al. (2005a)]. In this study, the remaining hrp genes, including the hrpC, hrpA, hrpS, hrpXY, hrpL and hrpJ operons, were determined. The hrp genes cluster (ca. 38 kb) was comprised of eight transcriptional units and contained nine hrc (hrp conserved) genes. The genetic organization of the hrp/hrc genes and their orientation for the transcriptions were also similar to and collinear with those of E. amylovora, showing ${\geq}80%$ homologies. However, ORFU1 and ORFU2 of unknown functions, present between the hrpA and hrpS operons of E. amylovora, were absent in E. pyrifoliae. To determine the HR active domains, several proteins were prepared from truncated fragments of the N-terminal and the C-terminal regions of $HrpN_{Ep}$ protein of E. pyrifoliae. The proteins prepared from the N-terminal region elicited HR, but not from those of the C-terminal region indicating that HR active domains are located in only N-terminal region of the $HrpN_{Ep}$ protein. Two synthetic oligopeptides produced HR on tobacco confirming presence of two HR active domains in the $HrpN_{Ep}$. The HR positive N-terminal fragment ($HN{\Delta}C187$) was further narrowed down by deleting C-terminal amino acids and internal amino acids to investigate whether amino acid insertion region have role in faster and stronger HR activity in $HrpN_{Ep}$ than $HrpN_{Ea}$. The $HrpN_{Ep}$ mutant proteins $HN{\Delta}C187$ (D1AIR), $HN{\Delta}C187$ (D2AIR) and $HN{\Delta}C187$ (DM41) retained similar HR activation to that of wild-type $HrpN_{Ep}$. However, the $HrpN_{Ep}$ mutant protein $HN{\Delta}C187$ (D3AIR) lacking third amino acid insertion region (102 to 113 aa) reduced HR when compared to that of wild-type $HrpN_{Ep}$. Reduction in HR elicitation could not be observed when single amino acids at different positions were substituted at third amino acids insertion region. But, substitution of amino acids at L103R, L106K and L110R showed reduction in HR activity on tobacco suggesting their importance in activation of HR faster in the $HrpN_{Ep}$ although it requires further detailed analysis.

Studying of the Effects of Gamichungsangboha-tang water-extract and ethanol-extract on $IFN{\gamma}$, IL-4, T-bet, GATA-3, c-maf in Asthma Model (가미청상보하탕(加味淸上補下湯)의 물과 에탄올 추출법에 따른 항(抗)알레르기 효과(效果)에 대(對)한 연구(硏究))

  • Heo, Tae-Seok;Ko, Eun-Jung;Jung, Hee-Jae;Rhee, Hyung-Koo;Bae, Hyun-Su;Jung, Sung-Ki
    • The Journal of Internal Korean Medicine
    • /
    • v.27 no.1
    • /
    • pp.40-54
    • /
    • 2006
  • Objective: This study aimed to identify the different effects of GMCSBHT water-extract and ethanol-extract on Th1/Th2 differentiation by monitoring Th1/Th2 specific cytokine secretion patterns and the transcriptional activities of T-bet, GATA-3, c-maf, $INF{\gamma}$ and IL-4. Materials and Methods: Spleen cells from eight week-old BALB/c mice were cultured in GMCSBHT extracts containing medium without activation for 24 hours and with activation for 48 hours. CD4+ T cells were isolated and mRNA expression levels of $INF{\gamma}$, IL-4, T-bet, GATA-3, c-maf by RT-PCR and secretion cytokines levels of $IFN{\gamma}$, IL-4 by ELISA were analyzed. Results: GMCSBHT extracts didn't have mitogenic effects on the unstimulated CD4+ T cells. In Th1 skewed condition, GMCSBAHT water extract had no significant effects on mRNA expression levels of $IFN{\gamma}$, T-bet and c-maf, but inhibited mRNA expression levels of IL-4, GATA-3. It showed significantly increased secretion cytokine levels of $IFN{\gamma}$, but had no significant effect on secretion cytokine levels of IL-4. In Th2 skewed condition, GMCSBHT ethanol extract inhibited mRNA expression levels of $INF{\gamma}$, IL-4, GATA-3 and c-maf significantly, but had no significant effects on mRNA expression levels of T-bet. It had no significant effects on secretion cytokine levels of $INF{\gamma}$, but showed remarkable inhibitory effects on secretion cytokine levels of IL-4. Conclusion: Results suggest that on Th1/Th2 deviation, GMCSBHT water extract has both amplifying effects on Th1 differentiation and inhibitory effects on Th2, but GMCSBHT ethanol extract has stronger inhibitory effects on Th2 differentiation than on Th1.

  • PDF

Anti-inflammatory effects of Rubus coreanus Miquel through inhibition of NF-${\kappa}B$ and MAP Kinase

  • Lee, Jung Eun;Cho, Soo-Muk;Park, Eunkyo;Lee, Seung Min;Kim, Yuri;Auh, Joong Hyuck;Choi, Hyung-Kyoon;Lim, Sohee;Lee, Sung Chul;Kim, Jung-Hyun
    • Nutrition Research and Practice
    • /
    • v.8 no.5
    • /
    • pp.501-508
    • /
    • 2014
  • BACKGROUND/OBJECTIVES: Rubus Coreanus Miquel (RCM), used as a traditional Korean medicine, reduces chronic inflammatory diseases such as cancer and rheumatoid arthritis. However, its mechanism has not been elucidated. In this study, we examine the anti-inflammatory effects of RCM and their possible mechanisms using RAW 264.7 cells. MATERIALS/METHODS: Unripe RCM ethanol extract (UE), unripe RCM water extract (UH), ripe RCM ethanol extract (RE), and ripe RCM water extract (RH) were prepared. Inflammatory response was induced with LPS treatment, and expression of pro-inflammatory mediators (iNOS, COX-2, TNF-${\alpha}$, IL-$1{\beta}$, and IL-6) and NO and $PGE_2$ productions were assessed. To determine the anti-inflammatory mechanism of RCM, we measured NF-${\kappa}B$ and MAPK activities. RESULTS: UE and UH treatment significantly reduced NF-${\kappa}B$ activation and JNK and p38 phosphorylation and reduced transcriptional activities decreased iNOS, COX-2, and pro-inflammatory cytokines expressions, and NO and $PGE_2$ productions. RE and RH treatments reduced IL-$1{\beta}$ and IL-6 expressions through suppressions of JNK and p38 phosphorylation. CONCLUSIONS: In this study, we showed that RCM had anti-inflammatory effects by suppression of pro-inflammatory mediator expressions. Especially, unripe RCM showed strong anti-inflammatory effects through suppression of NF-${\kappa}B$ and MAPK activation. These findings suggest that unripe RCM might be used as a potential functional material to reduce chronic inflammatory responses.

The Anticancer Mechanisms of Taxol-Diethylenetriamine pentaacetate Conjugate in HT29 Human Colorectal Cancer cells

  • Lee, Na-Kyung;Kim, Hyun-Jeong;Yang, Seung-Ju;Kim, Yoon-Suk;Choi, Hyun-Il;Shim, Moon-Jeong;Awh, Ok-Doo;Kim, Tae-Ue
    • BMB Reports
    • /
    • v.34 no.3
    • /
    • pp.237-243
    • /
    • 2001
  • Taxol, a natural product extracted from the Taxus brevifolia, is known to have significant anti-tumor activities against many common cancers, including ovarian and breast cancers. Despite the pronounced anti-tumor activity of this compound, its poor solubility in aqueous solutions hampers its clinical applications. We studied the anticancer mechanisms of the water-soluble taxol diethylenetriamine pentaacetate (DTPA) used for radiolabeling, and compared it to that of taxol. In vitro cytotoxicities of taxol and taxol-DTPA conjugate were tested in HT29 human colorectal cancer cells by the MTT method. As the result, the $IC_{50}$ value of the taxol-DTPA conjugate was about three fold higher than that of taxol. When analyzed by an agarose gel electrophoresis, the DNA ladders became evident after the incubation of cells with the taxol-DTPA conjugate for 24 h. We also found morphological changes of the cells undergoing apoptosis with electron microscopy Next, we examined the signal pathway of taxol-DTPA conjugate-induced apoptosis in HT29 cells. The activation of extracellular signal-regulated protein kinase (ERK1/2) occurred at 10, 30, 60 and 120 min after 200 nM taxol-DTPA conjugate treatment. The pretreatment of the MEK inhibitor (PD98059) completely blocked the taxol-DTPA conjugate-induced ERK1/2 activation. The activated ERK1/2 translocated into the nucleus at the same time and phosphorylated its transcriptional factor, c-Jun. These results suggest that the taxol-DTPA conjugate has an apoptotic activity in HT29 cells, and that its proapoptic activity might be related with the signal transduction via ERK1/2 and c-Jun similar to that of taxol.

  • PDF