• 제목/요약/키워드: G protein signaling

검색결과 463건 처리시간 0.031초

Diethylstilbestrol의 단핵구의 세포간 유착과정 조절효과 (Modulatory Effect of Diethylstilbestrol on CD29-Mediated Cell-cell Adhesion in Monocytic U937 Cells)

  • 김병훈;조재열
    • 약학회지
    • /
    • 제52권2호
    • /
    • pp.111-116
    • /
    • 2008
  • Diethylstilbestrol (DESB) is a synthetic estrogen not only that routinely prescribed, but also that known to be a teratogen. In this study, we found a novel pharmacological feature that DESB is able to positively modulate CD29 $({\beta}1-integrin)$ function. Thus, DESB up-regulated homotypic cell-cell adhesion of monocytic U937 cells mediated by CD29. However, DESB did not increase the surface level of CD29 and its binding activity to ligand (fibronectin), according to flow cytometric analysis and cell-fibronectin adhesion assay. Instead, the DESB-mediated up-regulation of cell-cell adhesion was blocked by several signaling enzyme inhibitors. Treatment of U0126 [an extracellular signal-regulated kinase (ERK) inhibitor], SB20358 (a p38 inhibitor) or Rp-8-pCPT-cGMP (a protein kinase G inhibitor) clearly inhibited DESB-mediated up-regulation of cell-cell adhesion induced by CD29. However, estrogen receptor antagonist ICI 182,780 failed to abrogate DESB effect. Therefore, our data suggest that DESB may up-regulate CD29-mediated cell-cell adhesion via modulating intracellular signaling enzymes such as ERK, PKG, and p38, independent of estrogen receptor function.

SIFamide and SIFamide Receptor Define a Novel Neuropeptide Signaling to Promote Sleep in Drosophila

  • Park, Sangjin;Sonn, Jun Young;Oh, Yangkyun;Lim, Chunghun;Choe, Joonho
    • Molecules and Cells
    • /
    • 제37권4호
    • /
    • pp.295-301
    • /
    • 2014
  • SIFamide receptor (SIFR) is a Drosophila G protein-coupled receptor for the neuropeptide SIFamide (SIFa). Although the sequence and spatial expression of SIFa are evolutionarily conserved among insect species, the physiological function of SIFa/SIFR signaling remains elusive. Here, we provide genetic evidence that SIFa and SIFR promote sleep in Drosophila. Either genetic ablation of SIFa-expressing neurons in the pars intercerebralis (PI) or pan-neuronal depletion of SIFa expression shortened baseline sleep and reduced sleep-bout length, suggesting that it caused sleep fragmentation. Consistently, RNA interference-mediated knockdown of SIFR expression caused short sleep phenotypes as observed in SIFa-ablated or depleted flies. Using a panel of neuron-specific Gal4 drivers, we further mapped SIFR effects to subsets of PI neurons. Taken together, these results reveal a novel physiological role of the neuropeptide SIFa/SIFR pathway to regulate sleep through sleep-promoting neural circuits in the PI of adult fly brains.

ERK1/2 activation by the C. elegans muscarinic acetylcholine receptor GAR-3 in cultured mammalian cells involves multiple signaling pathways

  • Shin, Young-Mi;Shin, Young-Ju;Kim, Seung-Woo;Park, Yang-Seo;Cho, Nam-Jeong
    • Animal cells and systems
    • /
    • 제14권3호
    • /
    • pp.155-160
    • /
    • 2010
  • Extracellular signal-regulated kinases 1/2 (ERK1/2) play important roles in a variety of biological processes including cell growth and differentiation. We have previously reported that GAR-3 activates ERK1/2 via phospholipase C and protein kinase C, presumably through pertussis toxin (PTX)-insensitive Gq proteins, in Chinese hamster ovary (CHO) cells. Here we provide evidence that GAR-3 also activates ERK1/2 through PTX-sensitive G proteins, phosphatidylinositol 3-kinase (PI 3-kinase), and Src family kinases in CHO cells. We further show that in human embryonic kidney (HEK293) cells, epidermal growth factor receptor and Ras are required for efficient ERK1/2 activation by GAR-3. Taken together, our data indicate that GAR-3 evokes ERK1/2 activation through multiple signaling pathways in cultured mammalian cells.

Protein-protein Interaction Network Analyses for Elucidating the Roles of LOXL2-delta72 in Esophageal Squamous Cell Carcinoma

  • Wu, Bing-Li;Zou, Hai-Ying;Lv, Guo-Qing;Du, Ze-Peng;Wu, Jian-Yi;Zhang, Pi-Xian;Xu, Li-Yan;Li, En-Min
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제15권5호
    • /
    • pp.2345-2351
    • /
    • 2014
  • Lysyl oxidase-like 2 (LOXL2), a member of the lysyl oxidase (LOX) family, is a copper-dependent enzyme that catalyzes oxidative deamination of lysine residues on protein substrates. LOXL2 was found to be overexpressed in esophageal squamous cell carcinoma (ESCC) in our previous research. We later identified a LOXL2 splicing variant LOXL2-delta72 and we overexpressed LOXL2-delta72 and its wild type counterpart in ESCC cells following microarray analyses. First, the differentially expressed genes (DEGs) of LOXL2 and LOXL2-delta72 compared to empty plasmid were applied to generate protein-protein interaction (PPI) sub-networks. Comparison of these two sub-networks showed hundreds of different proteins. To reveal the potential specific roles of LOXL2- delta72 compared to its wild type, the DEGs of LOXL2-delta72 vs LOXL2 were also applied to construct a PPI sub-network which was annotated by Gene Ontology. The functional annotation map indicated the third PPI sub-network involved hundreds of GO terms, such as "cell cycle arrest", "G1/S transition of mitotic cell cycle", "interphase", "cell-matrix adhesion" and "cell-substrate adhesion", as well as significant "immunity" related terms, such as "innate immune response", "regulation of defense response" and "Toll signaling pathway". These results provide important clues for experimental identification of the specific biological roles and molecular mechanisms of LOXL2-delta72. This study also provided a work flow to test the different roles of a splicing variant with high-throughput data.

Hesperidin Induces Apoptosis by Inhibiting Sp1 and Its Regulatory Protein in MSTO-211H Cells

  • Lee, Kyung-Ae;Lee, Sang-Han;Lee, Yong-Jin;Baeg, Seung-Mi;Shim, Jung-Hyun
    • Biomolecules & Therapeutics
    • /
    • 제20권3호
    • /
    • pp.273-279
    • /
    • 2012
  • Hesperidin, a flavanone present in citrus fruits, has been studied as potential therapeutic agents that have anti-tumor activity and apoptotic effects in several cancers, but there is no report about the apoptotic effect of hesperidin in human malignant pleural mesothelioma through the specificity protein 1 (Sp1) protein. We investigated whether hesperidin inhibited cell growth and regulated Sp1 target proteins by suppressing the levels of Sp1 protein in MSTO-211H cells. The $IC_{50}$ value of hesperidin was determined to be 152.3 ${\mu}M$ in MSTO-211H cells for 48 h. Our results suggested that hesperidin (0-160 ${\mu}M$) decreased cell viability, and induced apoptotic cell death. Hesperidin increased Sub-$G_1$ population in MSTO-211H cells. Hesperidin significantly suppressed mRNA/protein level of Sp1 and modulated the expression level of the Sp1 regulatory protein such as p27, p21, cyclin D1, Mcl-1, and survivin in mesothelioma cells. Also, hesperidin induced apoptotic signaling including: cleavages of Bid, caspase-3, and PARP, upregulation of Bax, and down-regulation of Bcl-$_{xl}$ in mesothelioma cells. These results show that hesperidin suppressed mesothelioma cell growth through inhibition of Sp1. In this study, we demonstrated that Sp1 acts as a novel molecular target of hesperidin in human malignant pleural mesothelioma.

Melanin extract from Gallus gallus domesticus promotes proliferation and differentiation of osteoblastic MG-63 cells via bone morphogenetic protein-2 signaling

  • Yoo, Han-Seok;Chung, Kang-Hyun;Lee, Kwon-Jai;Kim, Dong-Hee;An, Jeung Hee
    • Nutrition Research and Practice
    • /
    • 제11권3호
    • /
    • pp.190-197
    • /
    • 2017
  • BACKGROUND/OBJECTIVES: Gallus gallus domesticus (GD) is a natural mutant breed of chicken in Korea with an atypical characterization of melanin in its tissue. This study investigated the effects of melanin extracts of GD on osteoblast differentiation and inhibition of osteoclast formation. MATERIALS/METHODS: The effects of the melanin extract of GD on human osteoblast MG-63 cell differentiation were examined by evaluating cell viability, osteoblast differentiation, and expression of osteoblast-specific transcription factors such as bone morphogenetic protein 2 (BMP-2), small mothers against decapentaplegic homologs 5 (SMAD5), runt-related transcription factor 2 (RUNX2), osteocalcin and type 1 collagen (COL-1) by reverse transcription-polymerase chain reaction and western blotting analysis. We investigated the inhibitory effect of melanin on the osteoclasts formation through tartrate-resistant acid phosphatase (TRAP) activity and TRAP stains in Raw 264.7 cell. RESULTS: The melanin extract of GD was not cytotoxic to MG-63 cells at concentrations of $50-250{\mu}g/mL$. Alkaline phosphatase (ALP) activity and bone mineralization of melanin extract-treated cells increased in a dose-dependent manner from 50 to $250{\mu}g/mL$ and were 149% and 129% at $250{\mu}g/mL$ concentration, respectively (P < 0.05). The levels of BMP-2, osteocalcin, and COL-1 gene expression were significantly upregulated by 1.72-, 4.44-, and 2.12-fold in melanin-treated cells than in the control cells (P < 0.05). The levels of RUNX2 and SMAD5 proteins were higher in melanin-treated cells than in control vehicle-treated cells. The melanin extract attenuated the formation of receptor activator of nuclear factor kappa-B ligand-induced TRAP-positive multinucleated RAW 264.7 cells by 22%, and was 77% cytotoxic to RAW 264.7 macrophages at a concentration of $500{\mu}g/mL$. CONCLUSIONS: This study provides evidence that the melanin extract promoted osteoblast differentiation by activating BMP/SMADs/RUNX2 signaling and regulating transcription of osteogenic genes such as ALP, type I collagen, and osteocalcin. These results suggest that the effective osteoblastic differentiation induced by melanin extract from GD makes it potentially useful in maintaining bone health.

B16F10 멜라노마세포에서 과기음가미방의 멜라닌 생성 촉진 효과 (Stimulating effect of modified Goa-Gi-Um herbal remedy on melanogenesis in B16F10 melanoma cells)

  • 문나랑;김세윤;이진혁;이정복;박선민
    • 대한본초학회지
    • /
    • 제28권3호
    • /
    • pp.69-74
    • /
    • 2013
  • Objectives : Since hypopigmentation is known to increase the risk of skin cancer, melanogenesis in the skin needs to be regulated. Here, we evaluated the melanogenesis stimulatory effects of a modified Goagium herbal remedy (HR) and HR+ox bile (Bos taurus domesticus) extract (OBE) to address hypopigmentation disorders. Methods : B16F10 melanoma cells were treated with different dosages of HR and HR+OBE for 24 to 48 h after 1 h of 10 nM ${\alpha}$-melanocyte stimulating hormone (${\alpha}$-MSH). After the treatment, cell viability, tyrosinase activity, melanin synthesis and the expression of genes related to melanin synthesis were measured and the regulation of the ${\alpha}$-MSH signalling through cAMP responding element binding protein (CREB) was determined. Results : HR and HR+OBE with the ranges of $15{\sim}100{\mu}g/mL$ did not affect cell viability in melanoma cells. The 1 h treatment of HR+OBE (50 and $100{\mu}g/mL$) potentiated the phosphorylation of CREB by enhancing ${\alpha}$-MSH signaling and its 24 h treatment increased CREB expression. Consistent with CREB potentiation, their treatment for 24 h, the expression of microphthalmia-associated transcription factor (MIFT), tyrosinase, tyrosinase related protein (TRP)-1 and TRP-2 were increased in realtime PCR. Ultimately, the 48 h treatment of HR+OBE (50 and $100{\mu}g/mL$) increased tyrosniase activity and melanin contents in the melanoma cells in comparison to the control. Conclusions : HR+OBE (50 and $100{\mu}g/mL$) increases melanin synthesis in B16F10 melanoma cells via the stimulation of tyrosinase activity and expression of MIFT, tyrosinase, TRP-1 and TRP-2. HR+OBE can be used as the a possible treatment for hypopigmentation of the skin.

Effects of deoxynivalenol- and zearalenone-contaminated feed on the gene expression profiles in the kidneys of piglets

  • Reddy, Kondreddy Eswar;Lee, Woong;Jeong, Jin young;Lee, Yookyung;Lee, Hyun-Jeong;Kim, Min Seok;Kim, Dong-Woon;Yu, Dongjo;Cho, Ara;Oh, Young Kyoon;Lee, Sung Dae
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제31권1호
    • /
    • pp.138-148
    • /
    • 2018
  • Objective: Fusarium mycotoxins deoxynivalenol (DON) and zearalenone (ZEN), common contaminants in the feed of farm animals, cause immune function impairment and organ inflammation. Consequently, the main objective of this study was to elucidate DON and ZEN effects on the mRNA expression of pro-inflammatory cytokines and other immune related genes in the kidneys of piglets. Methods: Fifteen 6-week-old piglets were randomly assigned to three dietary treatments for 4 weeks: control diet, and diets contaminated with either 8 mg DON/kg feed or 0.8 mg ZEN/kg feed. Kidney samples were collected after treatment, and RNA-seq was used to investigate the effects on immune-related genes and gene networks. Results: A total of 186 differentially expressed genes (DEGs) were screened (120 upregulated and 66 downregulated). Gene ontology analysis revealed that the immune response, and cellular and metabolic processes were significantly controlled by these DEGs. The inflammatory stimulation might be an effect of the following enriched Kyoto encyclopedia of genes and genomes pathway analysis found related to immune and disease responses: cytokine-cytokine receptor interaction, chemokine signaling pathway, toll-like receptor signaling pathway, systemic lupus erythematosus (SLE), tuberculosis, Epstein-Barr virus infection, and chemical carcinogenesis. The effects of DON and ZEN on genome-wide expression were assessed, and it was found that the DEGs associated with inflammatory cytokines (interleukin 10 receptor, beta, chemokine [C-X-C motif] ligand 9, CXCL10, chemokine [C-C motif] ligand 4), proliferation (insulin like growth factor binding protein 4, IgG heavy chain, receptor-type tyrosine-protein phosphatase C, cytochrome P450 1A1, ATP-binding cassette sub-family 8), and other immune response networks (lysozyme, complement component 4 binding protein alpha, oligoadenylate synthetase 2, signaling lymphocytic activation molecule-9, ${\alpha}$-aminoadipic semialdehyde dehydrogenase, Ig lambda chain c region, pyruvate dehydrogenase kinase, isozyme 4, carboxylesterase 1), were suppressed by DON and ZEN. Conclusion: In summary, our results indicate that high concentrations of DON and ZEN suppress the inflammatory response in kidneys, leading to potential effects on immune homeostasis.

두경부암 세포주에서 상피성장인자수용체 타이로신 카이네이즈 억제제인 gefitinib의 성장억제에 관한 연구 (Growth inhibition in head and neck cancer cell lines by gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor)

  • 송승일;김명진
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • 제35권5호
    • /
    • pp.287-293
    • /
    • 2009
  • Cell survival is the result of a balance between programmed cell death and cellular proliferation. Cell membrane receptors and their associated signal transducing proteins control these processes. Of the numerous receptors and signaling proteins, epidermal growth factor receptor (EGFR) is one of the most important receptors involved in signaling pathways implicated in the proliferation and survival of cancer cells. EGFR is often highly expressed in human tumors including oral squamous cell carcinomas, and there is increasing evidence that high expression of EGFR is correlated with poor clinical outcome of common human cancers. Therefore, we examined the antiproliferative activity of gefitinib, epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI), in head and neck cancer cell lines. SCC-9, KB cells were cultured and growth inhibition activity of gefitinib was measured with MTT assay. To study influence of gefitinib in cell cycle, we performed cell cycle analysis with flow cytometry. Western blot was done to elucidate the expression of EGFR in cell lines and phosphorylation of EGFR and downstream kinase protein, Erk and Akt. Significant growth inhibition was observed in SCC-9 cells in contrast with KB cells. Also, flow cytometric analysis showed G1 phase arrest only in SCC-9 cells. In Western blot analysis for investigation of EGFR expression and downstream molecule phosphorylation, gefitinib suppressed phosphorylation of EGFR and downstream protein kinase Erk, Akt in SCC-9. However, in EGFR positive KB cells, weak expression of active form of Erk and Akt and no inhibitory activity of phosphorylation in Erk and Akt was observed. The antiproliferative activity of gefitinib was not correlated with EGFR expression and some possibility of phosphorylation of Erk and Akt as a predictive factor of gefitinib response was emerged. Further investigations on more reliable predictive factor indicating gefitinib response are awaited to be useful gefitinib treatment in head and neck cancer patients.

Reactive Oxygen Species and Nitrogen Species Differentially Regulate Neuronal Excitability in Rat Spinal Substantia Gelatinosa Neurons

  • Lee, Hae In;Park, A-Reum;Chun, Sang Woo
    • International Journal of Oral Biology
    • /
    • 제39권4호
    • /
    • pp.229-236
    • /
    • 2014
  • Reactive oxygen species (ROS) and nitrogen species (RNS) are implicated in cellular signaling processes and as a cause of oxidative stress. Recent studies indicate that ROS and RNS are important signaling molecules involved in nociceptive transmission. Xanthine oxidase (XO) system is a well-known system for superoxide anions ($O{_2}^{{\cdot}_-}$) generation, and sodium nitroprusside (SNP) is a representative nitric oxide (NO) donor. Patch clamp recording in spinal slices was used to investigate the role of $O{_2}^{{\cdot}_-}$ and NO on substantia gelatinosa (SG) neuronal excitability. Application of xanthine and xanthine oxidase (X/XO) compound induced membrane depolarization. Low concentration SNP ($10{\mu}M$) induced depolarization of the membrane, whereas high concentration SNP (1 mM) evoked membrane hyperpolarization. These responses were significantly decreased by pretreatment with phenyl N-tert-butylnitrone (PBN; nonspecific ROS and RNS scavenger). Addition of thapsigargin to an external calcium free solution for blocking synaptic transmission, led to significantly decreased X/XO-induced responses. Additionally, X/XO and SNP-induced responses were unchanged in the presence of intracellular applied PBN, indicative of the involvement of presynaptic action. Inclusion of GDP-${\beta}$-S or suramin (G protein inhibitors) in the patch pipette decreased SNP-induced responses, whereas it failed to decrease X/XO-induced responses. Pretreatment with n-ethylmaleimide (NEM; thiol-alkylating agent) decreased the effects of SNP, suggesting that these responses were mediated by direct oxidation of channel protein, whereas X/XO-induced responses were unchanged. These data suggested that ROS and RNS play distinct roles in the regulation of the membrane excitability of SG neurons related to the pain transmission.