Interplay between Trx-1 and S100P promotes colorectal cancer cell epithelial-mesenchymal transition by up-regulating S100A4 through AKT activation.

PubMed

Zuo, Zhigui; Zhang, Peili; Lin, Feiyan; Shang, Wenjing; Bi, Ruichun; Lu, Fengying; Wu, Jianbo; Jiang, Lei

2018-04-01

We previously reported a novel positive feedback loop between thioredoxin-1 (Trx-1) and S100P, which promotes the invasion and metastasis of colorectal cancer (CRC). However, the underlying molecular mechanisms remain poorly understood. In this study, we examined the roles of Trx-1 and S100P in CRC epithelial-to-mesenchymal transition (EMT) and their underlying mechanisms. We observed that knockdown of Trx-1 or S100P in SW620 cells inhibited EMT, whereas overexpression of Trx-1 or S100P in SW480 cells promoted EMT. Importantly, S100A4 and the phosphorylation of AKT were identified as potential downstream targets of Trx-1 and S100P in CRC cells. Silencing S100A4 or inhibition of AKT phosphorylation eliminated S100P- or Trx-1-mediated CRC cell EMT, migration and invasion. Moreover, inhibition of AKT activity reversed S100P- or Trx-1-induced S100A4 expression. The expression of S100A4 was higher in human CRC tissues compared with their normal counterpart tissues and was significantly correlated with lymph node metastasis and poor survival. The overexpression of S100A4 protein was also positively correlated with S100P or Trx-1 protein overexpression in our cohort of CRC tissues. In addition, overexpression of S100P reversed the Trx-1 knockdown-induced inhibition of S100A4 expression, EMT and migration and invasion in SW620 cells. The data suggest that interplay between Trx-1 and S100P promoted CRC EMT as well as migration and invasion by up-regulating S100A4 through AKT activation, thus providing further potential therapeutic targets for suppressing the EMT in metastatic CRC. © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Inhibition of gamma-secretase by the CK1 inhibitor IC261 does not depend on CK1delta.

PubMed

Höttecke, Nicole; Liebeck, Miriam; Baumann, Karlheinz; Schubenel, Robert; Winkler, Edith; Steiner, Harald; Schmidt, Boris

2010-05-01

CK1 and gamma-secretase are interesting targets for therapeutic intervention in the treatment of cancer and Alzheimer's disease. The CK1 inhibitor IC261 was reported to inhibit gamma-secretase activity. The question is: Does CK1 inhibition directly influence gamma-secretase activity? Therefore we analyzed the SAR of 15 analogues and their impact on gamma-secretase activity. The most active compounds were investigated on CK1delta activity. These findings exclude a direct influence of CK1delta on gamma-secretase, because any change in the substitution pattern of IC261 diminished CK1 inhibition, whereas gamma-secretase inhibition is still exerted by several analogues. 2010 Elsevier Ltd. All rights reserved.

S100A6 Protein Negatively Regulates CacyBP/SIP-Mediated Inhibition of Gastric Cancer Cell Proliferation and Tumorigenesis

PubMed Central

Zhang, Kun; Liang, Jie; Chuai, Yucai; Li, Yuan; Wang, Xiaoming

2012-01-01

Calcyclin-binding protein (CacyBP/SIP), identified on the basis of its ability to interact with S100 proteins in a calcium-dependent manner, was previously found to inhibit the proliferation and tumorigenesis of gastric cancer cells in our laboratory. Importantly, the effects of S100 proteins on the biological behavior of CacyBP/SIP in gastric cancer remain unclear. Herein, we report the construction of eukaryotic expression vectors for wild-type CacyBP/SIP and a truncated mutant lacking the S100 protein binding domain (CacyBP/SIPΔS100). The expressions of the wild-type and truncated recombinant proteins were demonstrated by transfection of MKN45 gastric cancer cells. Co-immunoprecipitation assays demonstrated interaction between S100A6 and wild-type CacyBP/SIP in MKN45 cells. Removal of the S100 protein binding domain dramatically reduced the affinity of CacyBP/SIP for S100 proteins as indicated by reduced co-immunoprecipitation of S100A6 by CacyBP/SIPΔS100. The MTT assay, FACS assay, clonogenic assay and tumor xenograft experiment were performed to assess the effect of CacyBP/SIP on cell growth and tumorigenesis in vitro and in vivo. Overexpression of CacyBP/SIP inhibited the proliferation and tumorigenesis of MKN45 gastric cancer cells; the proliferation and tumorigenesis rates were even further reduced by the expression of CacyBP/SIPΔS100. We also showed that S100 proteins negatively regulate CacyBP/SIP-mediated inhibition of gastric cancer cell proliferation, through an effect on β-catenin protein expression and transcriptional activation of Tcf/LEF. Although the underlying mechanism of action requires further investigation, this study provides new insight into the interaction between S100 proteins and CacyBP/SIP, which might enrich our knowledge of S100 proteins and be helpful for our understanding of the development of gastric cancer. PMID:22295074

Autophagosome-mediated EGFR down-regulation induced by the CK2 inhibitor enhances the efficacy of EGFR-TKI on EGFR-mutant lung cancer cells with resistance by T790M.

PubMed

So, Kwang Sup; Kim, Cheol Hyeon; Rho, Jin Kyung; Kim, Sun Ye; Choi, Yun Jung; Song, Joon Seon; Kim, Woo Sung; Choi, Chang Min; Chun, Young Jin; Lee, Jae Cheol

2014-01-01

Protein kinase CK2 has diverse functions promoting and maintaining cancer phenotypes. We investigated the effect of CK2 inhibition in lung cancer cells with T790M-mediated resistance to the EGFR-TK inhibitor. Resistant sublines of PC-9 to gefitinib (PC-9/GR) and erlotinib (PC-9/ER) were established by previous study, and T790M secondary mutation was found in both resistant sublines. A decrease of EGFR by siRNA treatment effectively controlled the growth of resistant cells, thus suggesting that they still have EGFR-dependency. CX-4945, a potent and selective CK2 inhibitor, induced autophagy in PC-9/GR and PC-9/ER, and which was supported by the induction of autophagic vacuoles and microtubule-associated protein 1 light chain 3 (LC3) expression, and the increase of punctate fluorescent signals in resistant cells pre-transfected with green fluorescent protein (GFP)-tagged LC3. However, the withdrawal of CX-4945 led to the recovery of cancer cells with autophagy. We found that the induction of autophagy by CX-4945 in both resistant cells was CK2 dependent by using small interfering RNA against CK2. The treatment with CX-4945 alone induced a minimal growth inhibition in resistant cells. However, combined treatment of CX-4945 and EGFR-TKI effectively inhibited cancer-cell proliferation and induced apoptosis. CX-4945 increased the translocation of EGFR from the cell surface into the autophagosome, subsequently leading to the decrease of EGFR while inhibition of autophagy by 3MA or Atg7-targeted siRNA pretreatment reduced the decrease of EGFR by CX-4945. Accordingly, apoptosis by a combination of CX-4945 and EGFR-TKI was suppressed by 3MA or Atg7-targeted siRNA pretreatment, thus suggesting that autophagosome-mediated EGFR down-regulation would have an important role regarding apoptotic cell death by EGFR-TKI. Combined treatment of the CK2 inhibitor and EGFR-TKI may be a promising strategy for overcoming T790M-mediated resistance.

CK2 phosphorylates and inhibits TAp73 tumor suppressor function to promote expression of cancer stem cell genes and phenotype in head and neck cancer.

PubMed

Lu, Hai; Yan, Carol; Quan, Xin Xin; Yang, Xinping; Zhang, Jialing; Bian, Yansong; Chen, Zhong; Van Waes, Carter

2014-10-01

Cancer stem cells (CSC) and genes have been linked to cancer development and therapeutic resistance, but the signaling mechanisms regulating CSC genes and phenotype are incompletely understood. CK2 has emerged as a key signal serine/threonine kinase that modulates diverse signal cascades regulating cell fate and growth. We previously showed that CK2 is often aberrantly expressed and activated in head and neck squamous cell carcinomas (HNSCC), concomitantly with mutant (mt) tumor suppressor TP53, and inactivation of its family member, TAp73. Unexpectedly, we observed that classical stem cell genes Nanog, Sox2, and Oct4, are overexpressed in HNSCC with inactivated TAp73 and mtTP53. However, the potential relationship between CK2, TAp73 inactivation, and CSC phenotype is unknown. We reveal that inhibition of CK2 by pharmacologic inhibitors or siRNA inhibits the expression of CSC genes and side population (SP), while enhancing TAp73 mRNA and protein expression. Conversely, CK2 inhibitor attenuation of CSC protein expression and the SP by was abrogated by TAp73 siRNA. Bioinformatic analysis uncovered a single predicted CK2 threonine phosphorylation site (T27) within the N-terminal transactivation domain of TAp73. Nuclear CK2 and TAp73 interaction, confirmed by co-immunoprecipitation, was attenuated by CK2 inhibitor, or a T27A point-mutation of this predicted CK2 threonine phospho-acceptor site of TAp73. Further, T27A mutation attenuated phosphorylation, while enhancing TAp73 function in repressing CSC gene expression and SP cells. A new CK2 inhibitor, CX-4945, inhibited CSC related SP cells, clonogenic survival, and spheroid formation. Our study unveils a novel regulatory mechanism whereby aberrant CK2 signaling inhibits TAp73 to promote the expression of CSC genes and phenotype.

CK2(beta)tes gene encodes a testis-specific isoform of the regulatory subunit of casein kinase 2 in Drosophila melanogaster.

PubMed

Kalmykova, Alla I; Shevelyov, Yuri Y; Polesskaya, Oksana O; Dobritsa, Anna A; Evstafieva, Alexandra G; Boldyreff, Brigitte; Issinger, Olaf-Georg; Gvozdev, Vladimir A

2002-03-01

An earlier described CK2(beta)tes gene of Drosophila melanogaster is shown to encode a male germline specific isoform of regulatory beta subunit of casein kinase 2. Western-analysis using anti-CK2(beta)tes Ig revealed CK2(beta)tes protein in Drosophila testes extract. Expression of a CK2(beta)tes-beta-galactosidase fusion protein driven by the CK2(beta)tes promoter was found in transgenic flies at postmitotic stages of spermatogenesis. Examination of biochemical characteristics of a recombinant CK2(beta)tes protein expressed in Escherichia coli revealed properties similar to those of CK2beta: (a) CK2(beta)tes protein stimulates CK2alpha catalytic activity toward synthetic peptide; (b) it inhibits phosphorylation of calmodulin and mediates stimulation of CK2alpha by polylysine; (c) it is able to form (CK2(beta)tes)2 dimers, as well as (CK2alpha)2(CK2(beta)tes)2 tetramers. Using the yeast two-hybrid system and coimmunoprecipitation analysis of protein extract from Drosophila testes, we demonstrated an association between CK2(beta)tes and CK2alpha. Northern-analysis has shown that another regulatory (beta') subunit found recently in D. melanogaster genome is also testis-specific. Thus, we describe the first example of two tissue-specific regulatory subunits of CK2 which might serve to provide CK2 substrate recognition during spermatogenesis.

S100A9 Interaction with TLR4 Promotes Tumor Growth

PubMed Central

Källberg, Eva; Vogl, Thomas; Liberg, David; Olsson, Anders; Björk, Per; Wikström, Pernilla; Bergh, Anders; Roth, Johannes; Ivars, Fredrik; Leanderson, Tomas

2012-01-01

By breeding TRAMP mice with S100A9 knock-out (S100A9−/−) animals and scoring the appearance of palpable tumors we observed a delayed tumor growth in animals devoid of S100A9 expression. CD11b+ S100A9 expressing cells were not observed in normal prostate tissue from control C57BL/6 mice but were readily detected in TRAMP prostate tumors. Also, S100A9 expression was observed in association with CD68+ macrophages in biopsies from human prostate tumors. Delayed growth of TRAMP tumors was also observed in mice lacking the S100A9 ligand TLR4. In the EL-4 lymphoma model tumor growth inhibition was observed in S100A9−/− and TLR4−/−, but not in RAGE−/− animals lacking an alternative S100A9 receptor. When expression of immune-regulating genes was analyzed using RT-PCR the only common change observed in mice lacking S100A9 and TLR4 was a down-regulation of TGFβ expression in splenic CD11b+ cells. Lastly, treatment of mice with a small molecule (ABR-215050) that inhibits S100A9 binding to TLR4 inhibited EL4 tumor growth. Thus, S100A9 and TLR4 appear to be involved in promoting tumor growth in two different tumor models and pharmacological inhibition of S100A9-TLR4 interactions is a novel and promising target for anti-tumor therapies. PMID:22470535

mTORC1 and CK2 coordinate ternary and eIF4F complex assembly

PubMed Central

Gandin, Valentina; Masvidal, Laia; Cargnello, Marie; Gyenis, Laszlo; McLaughlan, Shannon; Cai, Yutian; Tenkerian, Clara; Morita, Masahiro; Balanathan, Preetika; Jean-Jean, Olivier; Stambolic, Vuk; Trost, Matthias; Furic, Luc; Larose, Louise; Koromilas, Antonis E.; Asano, Katsura; Litchfield, David; Larsson, Ola; Topisirovic, Ivan

2016-01-01

Ternary complex (TC) and eIF4F complex assembly are the two major rate-limiting steps in translation initiation regulated by eIF2α phosphorylation and the mTOR/4E-BP pathway, respectively. How TC and eIF4F assembly are coordinated, however, remains largely unknown. We show that mTOR suppresses translation of mRNAs activated under short-term stress wherein TC recycling is attenuated by eIF2α phosphorylation. During acute nutrient or growth factor stimulation, mTORC1 induces eIF2β phosphorylation and recruitment of NCK1 to eIF2, decreases eIF2α phosphorylation and bolsters TC recycling. Accordingly, eIF2β mediates the effect of mTORC1 on protein synthesis and proliferation. In addition, we demonstrate a formerly undocumented role for CK2 in regulation of translation initiation, whereby CK2 stimulates phosphorylation of eIF2β and simultaneously bolsters eIF4F complex assembly via the mTORC1/4E-BP pathway. These findings imply a previously unrecognized mode of translation regulation, whereby mTORC1 and CK2 coordinate TC and eIF4F complex assembly to stimulate cell proliferation. PMID:27040916

The Design and Delivery of a Thermally Responsive Peptide to Inhibit S100B Mediated Neurodegeneration

PubMed Central

Hearst, Scoty M; Walker, Leslie R; Shao, Qingmei; Lopez, Mariper; Raucher, Drazen; Vig, Parminder J S

2011-01-01

S100B, a glial secreted protein is believed to play a major role in neurodegeneration in Alzheimer's disease, Down syndrome, traumatic brain injury and spinocerebellar ataxia type 1 (SCA1). SCA1 is a trinucleotide repeat disorder in which the expanded polyglutamine mutation in the protein ataxin-1 primarily targets Purkinje cells (PCs) of the cerebellum. Currently, the exact mechanism of S100B mediated PC damage in SCA1 is not clear. However, here we show that S100B may act via the activation of the RAGE signaling pathway resulting in oxidative stress mediated injury to mutant ataxin-1 expressing neurons. To combat S100B mediated neurodegeneration, we have designed a selective thermally responsive S100B inhibitory peptide, Synb1-ELP-TRTK. Our therapeutic polypeptide was developed using three key elements: (1) the elastin-like polypeptide (ELP), a thermally responsive polypeptide, (2) the TRTK12 peptide, a known S100B inhibitory peptide and (3) a cell penetrating peptide, Synb1, to enhance intracellular delivery. Binding studies revealed that our peptide, Synb1-ELP-TRTK, interacts with its molecular target S100B and maintains a high S100B binding affinity as comparable with the TRTK12 peptide alone. In addition, in vitro studies revealed that Synb1-ELP-TRTK treatment reduces S100B uptake in SHSY5Y cells. Furthermore, the Synb1-ELP-TRTK peptide decreased S100B induced oxidative damage to mutant ataxin-1 expressing neurons. To test the delivery capabilities of ELP based therapeutic peptides to the cerebellum; we treated mice with fluorescently labeled Synb1-ELP and observed that thermal targeting enhanced peptide delivery to the cerebellum. Here, we have laid the framework for thermal based therapeutic targeting to regions of the brain, particularly the cerebellum. Overall, our data suggests that thermal targeting of ELP based therapeutic peptides to the cerebellum is a novel treatment strategy for cerebellar neurodegenerative disorders. PMID:21958864

Casein kinase 2 (CK2) increases survivin expression via enhanced β-catenin–T cell factor/lymphoid enhancer binding factor-dependent transcription

PubMed Central

Tapia, J. C.; Torres, V. A.; Rodriguez, D. A.; Leyton, L.; Quest, A. F. G.

2006-01-01

Increased expression of casein kinase 2 (CK2) is associated with hyperproliferation and suppression of apoptosis in cancer. Mutations in the tumor suppressor APC (adenomatous polyposis coli) are frequent in colon cancer and often augment β-catenin–T cell factor (Tcf)/lymphoid enhancer binding factor (Lef)-dependent transcription of genes such as c-myc and cyclin-D1. CK2 has also been implicated recently in the regulation of β-catenin stability. To identify mechanisms by which CK2 promotes survival, effects of the specific CK2 inhibitors 4,5,6,7-tetrabromobenzotriazole (TBB) and 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole were assessed. TBB and 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole significantly decreased proliferation and increased apoptosis of HT29(US) colon cancer cells. RT-PCR and immunoblot analysis revealed that both inhibitors decreased survivin mRNA and protein levels in HT29(US) cells. Similar effects were observed with TBB in human DLD-1 and SW-480 colorectal cells as well as ZR-75 breast cancer cells and HEK-293T embryonic kidney cells. Expression of GFP–CK2α in HEK-293T cells resulted in β-catenin–Tcf/Lef-dependent up-regulation of survivin and increased resistance to anticancer drugs. Augmented β-catenin–Tcf/Lef-dependent transcription and resistance to apoptosis observed upon GFP–CK2α expression were abolished by TBB. Alternatively, HEK-293T cells expressing GFP–survivin were resistant to TBB-induced apoptosis. Finally, siRNA-mediated down-regulation of CK2α in HEK-293T cells coincided with reduced β-catenin and survivin levels. Taken together, these results suggest that CK2 kinase activity promotes survival by increasing survivin expression via β-catenin–Tcf/Lef-mediated transcription. Hence, selective CK2 inhibition or down-regulation in tumors may provide an attractive opportunity for the development of novel cancer therapies. PMID:17005722

S100A8, S100A9 and S100A12 activate airway epithelial cells to produce MUC5AC via extracellular signal-regulated kinase and nuclear factor-κB pathways

PubMed Central

Kang, Jin Hyun; Hwang, Sae Mi; Chung, Il Yup

2015-01-01

Airway mucus hyperproduction is a common feature of chronic airway diseases such as severe asthma, chronic obstructive pulmonary disease and cystic fibrosis, which are closely associated with neutrophilic airway inflammation. S100A8, S100A9 and S100A12 are highly abundant proteins released by neutrophils and have been identified as important biomarkers in many inflammatory diseases. Herein, we report a new role for S100A8, S100A9 and S100A12 for producing MUC5AC, a major mucin protein in the respiratory tract. All three S100 proteins induced MUC5AC mRNA and the protein in normal human bronchial epithelial cells as well as NCI-H292 lung carcinoma cells in a dose-dependent manner. A Toll-like receptor 4 (TLR4) inhibitor almost completely abolished MUC5AC expression by all three S100 proteins, while neutralization of the receptor for advanced glycation end-products (RAGE) inhibited only S100A12-mediated production of MUC5AC. The S100 protein-mediated production of MUC5AC was inhibited by the pharmacological agents that block prominent signalling molecules for MUC5AC expression, such as mitogen-activated protein kinases, nuclear factor-κB (NF-κB) and epidermal growth factor receptor. S100A8, S100A9 and S100A12 equally elicited both phosphorylation of extracellular signal-regulated kinase (ERK) and nuclear translocation of NF-κB/degradation of cytosolic IκB with similar kinetics through TLR4. In contrast, S100A12 preferentially activated the ERK pathway rather than the NF-κB pathway through RAGE. Collectively, these data reveal the capacity of these three S100 proteins to induce MUC5AC production in airway epithelial cells, suggesting that they all serve as key mediators linking neutrophil-dominant airway inflammation to mucin hyperproduction. PMID:24975020

Dynamic regulation of a metabolic multi-enzyme complex by protein kinase CK2.

PubMed

An, Songon; Kyoung, Minjoung; Allen, Jasmina J; Shokat, Kevan M; Benkovic, Stephen J

2010-04-09

The reversible association and dissociation of a metabolic multi-enzyme complex participating in de novo purine biosynthesis, the purinosome, was demonstrated in live cells to respond to the levels of purine nucleotides in the culture media. We also took advantage of in vitro proteomic scale studies of cellular substrates of human protein kinases (e.g. casein kinase II (CK2) and Akt), that implicated several de novo purine biosynthetic enzymes as kinase substrates. Here, we successfully identified that purinosome formation in vivo was significantly promoted in HeLa cells by the addition of small-molecule CK2-specific inhibitors (i.e. 4,5,6,7-tetrabromo-1H-benzimidazole, 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole, tetrabromocinammic acid, 4,4',5,5',6,6'-hexahydroxydiphenic acid 2,2',6,6'-dilactone (ellagic acid) as well as by silencing the endogenous human CK2alpha catalytic subunit with small interfering RNA. However, 4,5,6,7-tetrabromobenzotriazole, another CK2-specific inhibitor, triggered the dissociation of purinosome clusters in HeLa cells. Although the mechanism by which 4,5,6,7-tetrabromobenzotriazole affects purinosome clustering is not clear, we were capable of chemically reversing purinosome formation in cells by the sequential addition of two CK2 inhibitors. Collectively, we provide compelling cellular evidence that CK2-mediated pathways reversibly regulate purinosome assembly, and thus the purinosome may be one of the ultimate targets of kinase inhibitors.

Inflammation and pancreatic cancer: molecular and functional interactions between S100A8, S100A9, NT-S100A8 and TGFβ1

PubMed Central

2014-01-01

Background In order to gain further insight on the crosstalk between pancreatic cancer (PDAC) and stromal cells, we investigated interactions occurring between TGFβ1 and the inflammatory proteins S100A8, S100A9 and NT-S100A8, a PDAC-associated S100A8 derived peptide, in cell signaling, intracellular calcium (Cai2+) and epithelial to mesenchymal transition (EMT). NF-κB, Akt and mTOR pathways, Cai2+ and EMT were studied in well (Capan1 and BxPC3) and poorly differentiated (Panc1 and MiaPaCa2) cell lines. Results NT-S100A8, one of the low molecular weight N-terminal peptides from S100A8 to be released by PDAC-derived proteases, shared many effects on NF-κB, Akt and mTOR signaling with S100A8, but mainly with TGFβ1. The chief effects of S100A8, S100A9 and NT-S100A8 were to inhibit NF-κB and stimulate mTOR; the molecules inhibited Akt in Smad4-expressing, while stimulated Akt in Smad4 negative cells. By restoring Smad4 expression in BxPC3 and silencing it in MiaPaCa2, S100A8 and NT-S100A8 were shown to inhibit NF-κB and Akt in the presence of an intact TGFβ1 canonical signaling pathway. TGFβ1 counteracted S100A8, S100A9 and NT-S100A8 effects in Smad4 expressing, not in Smad4 negative cells, while it synergized with NT-S100A8 in altering Cai2+ and stimulating PDAC cell growth. The effects of TGFβ1 on both EMT (increased Twist and decreased N-Cadherin expression) and Cai2+ were antagonized by S100A9, which formed heterodimers with TGFβ1 (MALDI-TOF/MS and co-immuno-precipitation). Conclusions The effects of S100A8 and S100A9 on PDAC cell signaling appear to be cell-type and context dependent. NT-S100A8 mimics the effects of TGFβ1 on cell signaling, and the formation of complexes between TGFβ1 with S100A9 appears to be the molecular mechanism underlying the reciprocal antagonism of these molecules on cell signaling, Cai2+ and EMT. PMID:24670043

Inflammation and pancreatic cancer: molecular and functional interactions between S100A8, S100A9, NT-S100A8 and TGFβ1.

PubMed

Basso, Daniela; Bozzato, Dania; Padoan, Andrea; Moz, Stefania; Zambon, Carlo-Federico; Fogar, Paola; Greco, Eliana; Scorzeto, Michele; Simonato, Francesca; Navaglia, Filippo; Fassan, Matteo; Pelloso, Michela; Dupont, Sirio; Pedrazzoli, Sergio; Fassina, Ambrogio; Plebani, Mario

2014-03-26

In order to gain further insight on the crosstalk between pancreatic cancer (PDAC) and stromal cells, we investigated interactions occurring between TGFβ1 and the inflammatory proteins S100A8, S100A9 and NT-S100A8, a PDAC-associated S100A8 derived peptide, in cell signaling, intracellular calcium (Cai2+) and epithelial to mesenchymal transition (EMT). NF-κB, Akt and mTOR pathways, Cai2+ and EMT were studied in well (Capan1 and BxPC3) and poorly differentiated (Panc1 and MiaPaCa2) cell lines. NT-S100A8, one of the low molecular weight N-terminal peptides from S100A8 to be released by PDAC-derived proteases, shared many effects on NF-κB, Akt and mTOR signaling with S100A8, but mainly with TGFβ1. The chief effects of S100A8, S100A9 and NT-S100A8 were to inhibit NF-κB and stimulate mTOR; the molecules inhibited Akt in Smad4-expressing, while stimulated Akt in Smad4 negative cells. By restoring Smad4 expression in BxPC3 and silencing it in MiaPaCa2, S100A8 and NT-S100A8 were shown to inhibit NF-κB and Akt in the presence of an intact TGFβ1 canonical signaling pathway. TGFβ1 counteracted S100A8, S100A9 and NT-S100A8 effects in Smad4 expressing, not in Smad4 negative cells, while it synergized with NT-S100A8 in altering Cai2+ and stimulating PDAC cell growth. The effects of TGFβ1 on both EMT (increased Twist and decreased N-Cadherin expression) and Cai2+ were antagonized by S100A9, which formed heterodimers with TGFβ1 (MALDI-TOF/MS and co-immuno-precipitation). The effects of S100A8 and S100A9 on PDAC cell signaling appear to be cell-type and context dependent. NT-S100A8 mimics the effects of TGFβ1 on cell signaling, and the formation of complexes between TGFβ1 with S100A9 appears to be the molecular mechanism underlying the reciprocal antagonism of these molecules on cell signaling, Cai2+ and EMT.

CK2 and PML: regulating the regulator.

PubMed

Lallemand-Breitenbach, Valérie; de Thé, Hugues

2006-07-28

The PML protein induces senescence, and, upon oncogenic stress, its absence promotes cellular transformation. In this issue of Cell, Scaglioni et al. (2006) show that phosphorylation of PML by CK2, a kinase frequently activated in human cancers, promotes PML degradation. Therefore, pharmacological inhibition of CK2-induced PML loss could be used to offset tumor establishment.

Sensitization of interferon-γ induced apoptosis in human osteosarcoma cells by extracellular S100A4

PubMed Central

Pedersen, Kjetil Boye; Andersen, Kristin; Fodstad, Øystein; Mælandsmo, Gunhild Mari

2004-01-01

Background S100A4 is a small Ca2+-binding protein of the S100 family with metastasis-promoting properties. Recently, secreted S100A4 protein has been shown to possess a number of functions, including induction of angiogenesis, stimulation of cell motility and neurite extension. Methods Cell cultures from two human osteosarcoma cell lines, OHS and its anti-S100A4 ribozyme transfected counterpart II-11b, was treated with IFN-γ and recombinant S100A4 in order to study the sensitizing effects of extracellular S100A4 on IFN-γ mediated apoptosis. Induction of apoptosis was demonstrated by DNA fragmentation, cleavage of poly (ADP-ribose) polymerase and Lamin B. Results In the present work, we found that the S100A4-expressing human osteosarcoma cell line OHS was more sensitive to IFN-γ-mediated apoptosis than the II-11b cells. S100A4 protein was detected in conditioned medium from OHS cells, but not from II-11b cells, and addition of recombinant S100A4 to the cell medium sensitized II-11b cells to apoptosis induced by IFN-γ. The S100A4/IFN-γ-mediated induction of apoptosis was shown to be independent of caspase activation, but dependent on the formation of reactive oxygen species. Furthermore, addition of extracellular S100A4 was demonstrated to activate nuclear factor-κB (NF-κB). Conclusion In conclusion, we have shown that S100A4 sensitizes osteosarcoma cells to IFN-γ-mediated induction of apoptosis. Additionally, extracellular S100A4 activates NF-κB, but whether these events are causally related remains unknown. PMID:15318945

Differential Phosphorylation of Plant Translation Initiation Factors by Arabidopsis thaliana CK2 Holoenzymes*

PubMed Central

Dennis, Michael D.; Browning, Karen S.

2009-01-01

A previously described wheat germ protein kinase (Yan, T. F., and Tao, M. (1982) J. Biol. Chem. 257, 7037–7043) was identified unambiguously as CK2 using mass spectrometry. CK2 is a ubiquitous eukaryotic protein kinase that phosphorylates a wide range of substrates. In previous studies, this wheat germ kinase was shown to phosphorylate eIF2α, eIF3c, and three large subunit (60 S) ribosomal proteins (Browning, K. S., Yan, T. F., Lauer, S. J., Aquino, L. A., Tao, M., and Ravel, J. M. (1985) Plant Physiol. 77, 370–373). To further characterize the role of CK2 in the regulation of translation initiation, Arabidopsis thaliana catalytic (α1 and α2) and regulatory (β1, β2, β3, and β4) subunits of CK2 were cloned and expressed in Escherichia coli. Recombinant A. thaliana CK2β subunits spontaneously dimerize and assemble into holoenzymes in the presence of either CK2α1 or CK2α2 and exhibit autophosphorylation. The purified CK2 subunits were used to characterize the properties of the individual subunits and their ability to phosphorylate various plant protein substrates. CK2 was shown to phosphorylate eIF2α, eIF2β, eIF3c, eIF4B, eIF5, and histone deacetylase 2B but did not phosphorylate eIF1, eIF1A, eIF4A, eIF4E, eIF4G, eIFiso4E, or eIFiso4G. Differential phosphorylation was exhibited by CK2 in the presence of various regulatory β-subunits. Analysis of A. thaliana mutants either lacking or overexpressing CK2 subunits showed that the amount of eIF2β protein present in extracts was affected, which suggests that CK2 phosphorylation may play a role in eIF2β stability. These results provide evidence for a potential mechanism through which the expression and/or subcellular distribution of CK2 β-subunits could participate in the regulation of the initiation of translation and other physiological processes in plants. PMID:19509278

Centrosomal CK1delta Promotes Neurite Outgrowth | Center for Cancer Research

Cancer.gov

Previously we determined that Dishevelled-2/3 (Dvl) mediate Wnt-3a–dependent neurite outgrowth in Ewing sarcoma family tumor cells. Here we report that neurite extension was associated with Dvl phosphorylation and that both were inhibited by the casein kinase 1 (CK1) δ/ε inhibitor IC261. Small interfering RNAs targeting either CK1δ or CK1ε decreased Dvl phosphorylation, but

Casein Kinase 2 Reverses Tail-Independent Inhibition of Kinesin-1

NASA Astrophysics Data System (ADS)

Xu, Jing; Shu, Zhanyong; Anand, Preetha; Reddy, Babu; Cermelli, Silvia; Whisenant, Thomas; King, Stephen; Bardwell, Lee; Huang, Lan; Gross, Steven

2011-03-01

Kinesin-1 is a plus-end microtubule-based molecular motor, and defects in kinesin transport are linked to diseases including neurodegeneration. Kinesin can auto-inhibit via a direct head-tail interaction, but is believed to be active otherwise. In contrast, this study uncovers a fast but reversible inhibition distinct from the canonical auto-inhibition pathway. The majority of the initially active kinesin (full-length or tail-less) loses its ability to bind/interact with microtubule, and Casein Kinase 2 (CK2) reverses this inactivation (up to 4-fold) without altering kinesin's single motor properties. Motor phosphorylation is not required for this CK2 -mediated kinesin activation. In cultured mammalian cells, knockdown of CK2 level, but not kinase activity, was sufficient to decrease the force required to stall lipid droplet transport, consistent with a reduction in the number of active motors. We propose that CK2 forms a positive regulating complex with the motor. This study provides the first direct evidence of a protein kinase positively regulating kinesin-transport, and uncovers a pathway whereby inactive cargo-bound kinesin can be activated. This work is supported by NIGMS grants GM64624 and GM079156 to SPG, GM-74830 to LH, NIH grants GM76516 and GM60366 to LB, and AHA grant 825278F to JX.

Casein Kinase 2 Is a Novel Regulator of the Human Organic Anion Transporting Polypeptide 1A2 (OATP1A2) Trafficking.

PubMed

Chan, Ting; Cheung, Florence Shin Gee; Zheng, Jian; Lu, Xiaoxi; Zhu, Ling; Grewal, Thomas; Murray, Michael; Zhou, Fanfan

2016-01-04

Human organic anion transporting polypeptides (OATPs) mediate the influx of many important drugs into cells. Casein kinase 2 (CK2) is a critical protein kinase that phosphorylates >300 protein substrates and is dysregulated in a number of disease states. Among the CK2 substrates are several transporters, although whether this includes human OATPs has not been evaluated. The current study was undertaken to evaluate the regulation of human OATP1A2 by CK2. HEK-239T cells in which OATP1A2 was overexpressed were treated with CK2 specific inhibitors or transfected with CK2 specific siRNA, and the activity, expression, and subcellular trafficking of OATP1A2 was evaluated. CK2 inhibition decreased the uptake of the prototypic OATP1A2 substrate estrone-3-sulfate (E3S). Kinetic studies revealed that this was due to a decrease in the maximum velocity (Vmax) of E3S uptake, while the Michaelis constant was unchanged. The cell surface expression, but not the total cellular expression of OATP1A2, was impaired by CK2 inhibition and knockdown of the catalytic α-subunits of CK2. CK2 inhibition decreased the internalization of OATP1A2 via a clathrin-dependent pathway, decreased OATP1A2 recycling, and likely impaired OATP1A2 targeting to the cell surface. Consistent with these findings, CK2 inhibition also disrupted the colocalization of OATP1A2 and Rab GTPase (Rab)4-, Rab8-, and Rab9-positive endosomal and secretory vesicles. Taken together, CK2 has emerged as a novel regulator of the subcellular trafficking and stability of OATP1A2. Because OATP1A2 transports many molecules of physiological and pharmacological importance, the present data may inform drug selection in patients with diseases in which CK2 and OATP1A2 are dysregulated.

CK2 activity is required for the interaction of FGF14 with voltage-gated sodium channels and neuronal excitability

PubMed Central

Hsu, Wei-Chun J.; Scala, Federico; Nenov, Miroslav N.; Wildburger, Norelle C.; Elferink, Hannah; Singh, Aditya K.; Chesson, Charles B.; Buzhdygan, Tetyana; Sohail, Maveen; Shavkunov, Alexander S.; Panova, Neli I.; Nilsson, Carol L.; Rudra, Jai S.; Lichti, Cheryl F.; Laezza, Fernanda

2016-01-01

Recent data shows that fibroblast growth factor 14 (FGF14) binds to and controls the function of the voltage-gated sodium (Nav) channel with phenotypic outcomes on neuronal excitability. Mutations in the FGF14 gene in humans have been associated with brain disorders that are partially recapitulated in Fgf14−/− mice. Thus, signaling pathways that modulate the FGF14:Nav channel interaction may be important therapeutic targets. Bioluminescence-based screening of small molecule modulators of the FGF14:Nav1.6 complex identified 4,5,6,7-tetrabromobenzotriazole (TBB), a potent casein kinase 2 (CK2) inhibitor, as a strong suppressor of FGF14:Nav1.6 interaction. Inhibition of CK2 through TBB reduces the interaction of FGF14 with Nav1.6 and Nav1.2 channels. Mass spectrometry confirmed direct phosphorylation of FGF14 by CK2 at S228 and S230, and mutation to alanine at these sites modified FGF14 modulation of Nav1.6-mediated currents. In 1 d in vitro hippocampal neurons, TBB induced a reduction in FGF14 expression, a decrease in transient Na+ current amplitude, and a hyperpolarizing shift in the voltage dependence of Nav channel steady-state inactivation. In mature neurons, TBB reduces the axodendritic polarity of FGF14. In cornu ammonis area 1 hippocampal slices from wild-type mice, TBB impairs neuronal excitability by increasing action potential threshold and lowering firing frequency. Importantly, these changes in excitability are recapitulated in Fgf14−/− mice, and deletion of Fgf14 occludes TBB-dependent phenotypes observed in wild-type mice. These results suggest that a CK2-FGF14 axis may regulate Nav channels and neuronal excitability.—Hsu, W.-C. J., Scala, F., Nenov, M. N., Wildburger, N. C., Elferink, H., Singh, A. K., Chesson, C. B., Buzhdygan, T., Sohail, M., Shavkunov, A. S., Panova, N. I., Nilsson, C. L., Rudra, J. S., Lichti, C. F., Laezza, F. CK2 activity is required for the interaction of FGF14 with voltage-gated sodium channels and neuronal

Transcriptional Regulation of JARID1B/KDM5B Histone Demethylase by Ikaros, Histone Deacetylase 1 (HDAC1), and Casein Kinase 2 (CK2) in B-cell Acute Lymphoblastic Leukemia*

PubMed Central

Wang, Haijun; Song, Chunhua; Ding, Yali; Pan, Xiaokang; Ge, Zheng; Tan, Bi-Hua; Gowda, Chandrika; Sachdev, Mansi; Muthusami, Sunil; Ouyang, Hongsheng; Lai, Liangxue; Francis, Olivia L.; Morris, Christopher L.; Abdel-Azim, Hisham; Dorsam, Glenn; Xiang, Meixian; Payne, Kimberly J.; Dovat, Sinisa

2016-01-01

Impaired function of the Ikaros (IKZF1) protein is associated with the development of high-risk B-cell precursor acute lymphoblastic leukemia (B-ALL). The mechanisms of Ikaros tumor suppressor activity in leukemia are unknown. Ikaros binds to the upstream regulatory elements of its target genes and regulates their transcription via chromatin remodeling. Here, we report that Ikaros represses transcription of the histone H3K4 demethylase, JARID1B (KDM5B). Transcriptional repression of JARID1B is associated with increased global levels of H3K4 trimethylation. Ikaros-mediated repression of JARID1B is dependent on the activity of the histone deacetylase, HDAC1, which binds to the upstream regulatory element of JARID1B in complex with Ikaros. In leukemia, JARID1B is overexpressed, and its inhibition results in cellular growth arrest. Ikaros-mediated repression of JARID1B in leukemia is impaired by pro-oncogenic casein kinase 2 (CK2). Inhibition of CK2 results in increased binding of the Ikaros-HDAC1 complex to the promoter of JARID1B, with increased formation of trimethylated histone H3 lysine 27 and decreased histone H3 Lys-9 acetylation. In cases of high-risk B-ALL that carry deletion of one Ikaros (IKZF1) allele, targeted inhibition of CK2 restores Ikaros binding to the JARID1B promoter and repression of JARID1B. In summary, the presented data suggest a mechanism through which Ikaros and HDAC1 regulate the epigenetic signature in leukemia: via regulation of JARID1B transcription. The presented data identify JARID1B as a novel therapeutic target in B-ALL and provide a rationale for the use of CK2 inhibitors in the treatment of high-risk B-ALL. PMID:26655717

S100A4 interacts with p53 in the nucleus and promotes p53 degradation.

PubMed

Orre, L M; Panizza, E; Kaminskyy, V O; Vernet, E; Gräslund, T; Zhivotovsky, B; Lehtiö, J

2013-12-05

S100A4 is a small calcium-binding protein that is commonly overexpressed in a range of different tumor types, and it is widely accepted that S100A4 has an important role in the process of cancer metastasis. In vitro binding assays has shown that S100A4 interacts with the tumor suppressor protein p53, indicating that S100A4 may have additional roles in tumor development. In the present study, we show that endogenous S100A4 and p53 interact in complex samples, and that the interaction increases after inhibition of MDM2-dependent p53 degradation using Nutlin-3A. Further, using proximity ligation assay, we show that the interaction takes place in the cell nucleus. S100A4 knockdown experiments in two p53 wild-type cell lines, A549 and HeLa, resulted in stabilization of p53 protein, indicating that S100A4 is promoting p53 degradation. Finally, we demonstrate that S100A4 knockdown leads to p53-dependent cell cycle arrest and increased cisplatin-induced apoptosis. Thus, our data add a new layer to the oncogenic properties of S100A4 through its inhibition of p53-dependent processes.

CK2 is responsible for phosphorylation of human La protein serine-366 and can modulate rpL37 5'-terminal oligopyrimidine mRNA metabolism.

PubMed

Schwartz, Elena I; Intine, Robert V; Maraia, Richard J

2004-11-01

La protein binds precursors to 5S rRNA, tRNAs, and other transcripts that contain 3' UUU-OH and also promotes their maturation in the nucleus. Separate from this function, human La has been shown to positively modulate the translation of mRNAs that contain complex 5' regulatory motifs that direct internal initiation of translation. Nonphosphorylated La (npLa) inhibits pre-tRNA processing, while phosphorylation of human La serine-366 (S(366)) promotes pre-tRNA processing. npLa was found specifically associated with a class of mRNAs that have unusually short 5' untranslated regions comprised of terminal oligopyrimidine (5'TOP) tracts and that encode ribosomal proteins and translation elongation factors. Although La S(366) represents a CK2 phosphorylation site, there was no evidence that CK2 phosphorylates it in vivo. We used the CK2-specific inhibitor, 4,5,6,7-tetrabromo-2-azabenzimidazole (TBB), and antisense-mediated knockdown to demonstrate that CK2 is responsible for La S(366) phosphorylation in vivo. Hypophosphorylation was not associated with significant change in total La levels or proteolytic cleavage. Quantitative reverse transcription-PCR revealed increased association of the 5'TOP-mRNA encoding ribosomal protein L37 (rpL37) with La after TBB treatment. Transfection revealed more rpL37 mRNA associated with nonphosphorylatable La A(366) than with La S(366), concomitant with La A(366)-specific shift of a fraction of L37 mRNA off polysomes. The data indicate that CK2 phosphorylates La S(366) in vivo, that this limits 5'TOP mRNA binding, and that increasing npLa leads to greater association with potentially negative effects on TOP mRNA translation. Consistent with data that indicate that phosphorylation reverses negative effects of npLa on tRNA production, the present data suggest that CK2 phosphorylation of La can affect production of the translational machinery.

Evaluation of a UCMK/dCK fusion enzyme for gemcitabine-mediated cytotoxicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Adam J.; Brown, Melissa N.; Black, Margaret E., E-mail: blackm@vetmed.wsu.edu

2011-12-09

Highlights: Black-Right-Pointing-Pointer Goal was to enhance dFdC cytotoxicity by the creation of a UCMK/dCK fusion enzyme. Black-Right-Pointing-Pointer The UCMK/dCK fusion enzyme possesses both native activities. Black-Right-Pointing-Pointer The fusion renders cells equally sensitive to dFdC relative to dCK expression alone. Black-Right-Pointing-Pointer Dual activities of fusion not sufficient to augment cell dFdC sensitivity in vitro. Black-Right-Pointing-Pointer Data may warrant the implementation of UCMK mutagenesis studies. -- Abstract: While gemcitabine (2 Prime -2 Prime -difluoro-2 Prime -deoxycytidine, dFdC) displays wide-ranging antineoplastic activity as a single agent, variable response rates and poor intracellular metabolism often limit its clinical efficacy. In an effort to enhancemore » dFdC cytotoxicity and help normalize response rates, we created a bifunctional fusion enzyme that combines the enzymatic activities of deoxycytidine kinase (dCK) and uridine/cytidine monophosphate kinase (UCMK) in a single polypeptide. Our goal was to evaluate whether the created fusion could induce beneficial, functional changes toward dFdC, expedite dFdC conversion to its active antimetabolites and consequently amplify cell dFdC sensitivity. While kinetic analyses revealed the UCMK/dCK fusion enzyme to possess both native activities, the fusion rendered cells sensitive to the cytotoxic effects of dFdC at the same level as dCK expression alone. These results suggest that increased wild-type UCMK expression does not provide a significant enhancement in dFdC-mediated cytotoxicity and may warrant the implementation of studies aimed at engineering UCMK variants with improved activity toward gemcitabine monophosphate.« less

Underlying mechanisms of cyclic peptide inhibitors interrupting the interaction of CK2α/CK2β: comparative molecular dynamics simulation studies.

PubMed

Zhou, Yue; Zhang, Na; Chen, Wenjuan; Zhao, Lijiao; Zhong, Rugang

2016-04-07

Protein-protein interactions (PPIs) are fundamental to all biological processes. Recently, the CK2β-derived cyclic peptide Pc has been demonstrated to efficiently antagonize the CK2α/CK2β interaction and strongly affect the phosphorylation of CK2β-dependent CK2 substrate specificity. The binding affinity of Pc to CK2α is destroyed to different extents by two single-point mutations of Tyr188 to Ala (Y188A) and Phe190 to Ala (F190A), which exert negative effects on the inhibitory activity (IC50) of Pc against the CK2α/CK2β interaction from 3.0 μM to 54.0 μM and ≫100 μM, respectively. However, the structural influences of Y188A and F190A mutations on the CK2α-Pc complex remain unclear. In this study, comparative molecular dynamics (MD) simulations, principal component analysis (PCA), domain cross-correlation map (DCCM) analysis and energy calculations were performed on wild type (WT), Y188A mutant, and F190A mutant systems. The results revealed that ordered communications between hydrophobic and polar interactions were essential for CK2α-Pc binding in the WT system. In addition to the loss of the hydrogen bond between Gln36 of CK2α and Gly189 of Pc in the two mutants, the improper recognition mechanisms occurred through different pathways. These pathways included the weakened hydrophobic interactions in the Y188A mutant as well as decreased polar and hydrophobic interactions in the F190A mutant. The energy analysis results qualitatively elucidated the instability of the two mutants and energetic contributions of the key residues. This study not only revealed the structural mechanisms for the decreased binding affinity of Y188A and F190A mutant CK2α-Pc complexes, but also provided valuable clues for the rational design of CK2α/CK2β subunit interaction inhibitors with high affinity and specificity.

Serum S100B level increases after running but not cycling exercise.

PubMed

Stocchero, Cintia Mussi Alvim; Oses, Jean Pierre; Cunha, Giovani Santos; Martins, Jocelito Bijoldo; Brum, Liz Marina; Zimmer, Eduardo Rigon; Souza, Diogo Onofre; Portela, Luis Valmor; Reischak-Oliveira, Alvaro

2014-03-01

The objective of this study was to investigate the effect of running versus cycling exercises upon serum S100B levels and typical markers of skeletal muscle damage such as creatine kinase (CK), aspartate aminotransferase (AST) and myoglobin (Mb). Although recent work demonstrates that S100B is highly expressed and exerts functional properties in skeletal muscle, there is no previous study that tries to establish a relationship between muscle damage and serum S100B levels after exercise. We conducted a cross-sectional study on 13 male triathletes. They completed 2 submaximal exercise protocols at anaerobic threshold intensity. Running was performed on a treadmill with no inclination (RUN) and cycling (CYC) using a cycle-simulator. Three blood samples were taken before (PRE), immediately after (POST) and 1 h after exercise for CK, AST, Mb and S100B assessments. We found a significant increase in serum S100B levels and muscle damage markers in RUN POST compared with RUN PRE. Comparing groups, POST S100B, CK, AST and Mb serum levels were higher in RUN than CYC. Only in RUN, the area under the curve (AUC) of serum S100B is positively correlated with AUC of CK and Mb. Therefore, immediately after an intense exercise such as running, but not cycling, serum levels of S100B protein increase in parallel with levels of CK, AST and Mb. Additionally, the positive correlation between S100B and CK and Mb points to S100B as an acute biomarker of muscle damage after running exercise.

CK2 Is Responsible for Phosphorylation of Human La Protein Serine-366 and Can Modulate rpL37 5′-Terminal Oligopyrimidine mRNA Metabolism

PubMed Central

Schwartz, Elena I.; Intine, Robert V.; Maraia, Richard J.

2004-01-01

La protein binds precursors to 5S rRNA, tRNAs, and other transcripts that contain 3′ UUU-OH and also promotes their maturation in the nucleus. Separate from this function, human La has been shown to positively modulate the translation of mRNAs that contain complex 5′ regulatory motifs that direct internal initiation of translation. Nonphosphorylated La (npLa) inhibits pre-tRNA processing, while phosphorylation of human La serine-366 (S366) promotes pre-tRNA processing. npLa was found specifically associated with a class of mRNAs that have unusually short 5′ untranslated regions comprised of terminal oligopyrimidine (5′TOP) tracts and that encode ribosomal proteins and translation elongation factors. Although La S366 represents a CK2 phosphorylation site, there was no evidence that CK2 phosphorylates it in vivo. We used the CK2-specific inhibitor, 4,5,6,7-tetrabromo-2-azabenzimidazole (TBB), and antisense-mediated knockdown to demonstrate that CK2 is responsible for La S366 phosphorylation in vivo. Hypophosphorylation was not associated with significant change in total La levels or proteolytic cleavage. Quantitative reverse transcription-PCR revealed increased association of the 5′TOP-mRNA encoding ribosomal protein L37 (rpL37) with La after TBB treatment. Transfection revealed more rpL37 mRNA associated with nonphosphorylatable La A366 than with La S366, concomitant with La A366-specific shift of a fraction of L37 mRNA off polysomes. The data indicate that CK2 phosphorylates La S366 in vivo, that this limits 5′TOP mRNA binding, and that increasing npLa leads to greater association with potentially negative effects on TOP mRNA translation. Consistent with data that indicate that phosphorylation reverses negative effects of npLa on tRNA production, the present data suggest that CK2 phosphorylation of La can affect production of the translational machinery. PMID:15485924

Agonist-induced CXCR4 and CB2 Heterodimerization Inhibits Gα13/RhoA-mediated Migration.

PubMed

Scarlett, Kisha A; White, El-Shaddai Z; Coke, Christopher J; Carter, Jada R; Bryant, Latoya K; Hinton, Cimona V

2018-04-01

G-protein-coupled receptor (GPCR) heterodimerization has emerged as a means by which alternative signaling entities can be created; yet, how receptor heterodimers affect receptor pharmacology remains unknown. Previous observations suggested a biochemical antagonism between GPCRs, CXCR4 and CB2 (CNR2), where agonist-bound CXCR4 and agonist-bound CB2 formed a physiologically nonfunctional heterodimer on the membrane of cancer cells, inhibiting their metastatic potential in vitro However, the reduced signaling entities responsible for the observed functional outputs remain elusive. This study now delineates the signaling mechanism whereby heterodimeric association between CXCR4 and CB2, induced by simultaneous agonist treatment, results in decreased CXCR4-mediated cell migration, invasion, and adhesion through inhibition of the Gα13/RhoA signaling axis. Activation of CXCR4 by its cognate ligand, CXCL12, stimulates Gα13 (GNA13), and subsequently, the small GTPase RhoA, which is required for directional cell migration and the metastatic potential of cancer cells. These studies in prostate cancer cells demonstrate decreased protein expression levels of Gα13 and RhoA upon simultaneous CXCR4/CB2 agonist stimulation. Furthermore, the agonist-induced heterodimer abrogated RhoA-mediated cytoskeletal rearrangement resulting in the attenuation of cell migration and invasion of an endothelial cell barrier. Finally, a reduction was observed in the expression of integrin α5 (ITGA5) upon heterodimerization, supported by decreased cell adhesion to extracellular matrices in vitro Taken together, the data identify a novel pharmacologic mechanism for the modulation of tumor cell migration and invasion in the context of metastatic disease. Implications: This study investigates a signaling mechanism by which GPCR heterodimerization inhibits cancer cell migration. Mol Cancer Res; 16(4); 728-39. ©2018 AACR . ©2018 American Association for Cancer Research.

Protein kinase CK2α catalytic subunit ameliorates diabetic renal inflammatory fibrosis via NF-κB signaling pathway.

PubMed

Huang, Junying; Chen, Zhiquan; Li, Jie; Chen, Qiuhong; Li, Jingyan; Gong, Wenyan; Huang, Jiani; Liu, Peiqing; Huang, Heqing

2017-05-15

Activation of casein kinase 2 (CK2) is closely linked to the body disturbance of carbohydrate metabolism and inflammatory reaction. The renal chronic inflammatory reaction in the setting of diabetes is one of the important hallmarks of diabetic renal fibrosis. However, it remains unknown whether CK2 influences the process of diabetic renal fibrosis. The current study is aimed to investigate if CK2α ameliorates renal inflammatory fibrosis in diabetes via NF-κB pathway. To explore potential regulatory mechanism of CK2α, the expression and activity of CK2α, which were studied by plasmid transfection, selective inhibitor, small-interfering RNA (siRNA) and adenovirus infection in vitro or in vivo, were analyzed by means of western blotting (WB), dual luciferase reporter assay and electrophoretic mobility shift assay (EMSA). The following findings were observed: (1) Expression of CK2α was upregulated in kidneys of db/db and KKAy diabetic mice; (2) Inhibition of CK2α kinase activity or knockdown of CK2α protein expression suppressed high glucose-induced expressions of FN and ICAM-1 in glomerular mesangial cells (GMCs); (3) Inhibition of CK2α kinase activity or knockdown of CK2α protein expression not only restrained IκB degradation, but also suppressed HG-induced nuclear accumulation, transcriptional activity and DNA binding activity of NF-κB in GMCs; (4) Treatment of TBB or CK2α RNAi adenovirus infection ameliorated renal fibrosis in diabetic animals; (5) Treatment of TBB or CK2α RNAi adenovirus infection suppressed IκB degradation and NF-κB nuclear accumulation in glomeruli of diabetic animals. This study indicates the essential role of CK2α in regulating the diabetic renal pathological process of inflammatory fibrosis via NF-κB pathway, and inhibition of CK2α may serve as a promising therapeutic strategy for diabetic nephropathy. Copyright © 2017 Elsevier Inc. All rights reserved.

S100A12 and the S100/Calgranulins - Emerging Biomarkers for Atherosclerosis and Possibly Therapeutic Targets

PubMed Central

Oesterle, Adam; Hofmann Bowman, Marion A

2016-01-01

Atherosclerosis is mediated by local and systematic inflammation. The multi-ligand receptor for advanced glycation end products (RAGE) has been studied in animals and humans, and is an important mediator of inflammation and atherosclerosis. This review focuses on S100/calgranulin proteins (S100A8, S100A9, and S100A12) and their receptor RAGE in mediating vascular inflammation. Mice lack the gene for S100A12, which in humans is located on chromosome 3 between S100A8 and S100A9. Transgenic mice with smooth muscle cell targeted expression of S100A12 demonstrate increased coronary and aortic calcification as well as increased plaque vulnerability. Serum S100A12 has recently been shown to predict future cardiovascular events in a longitudinal population study, underscoring a role for S100A12 as a potential biomarker for coronary artery disease. Genetic ablation of S100A9 or RAGE in atherosclerosis susceptible Apolipoprotein E (ApoE) null mice results in reduced atherosclerosis. Importantly, S100A12 and the RAGE axis can be modified pharmacologically. For example, soluble RAGE reduces murine atherosclerosis and vascular inflammation. Additionally, a class of compounds currently in phase III clinical trials for multiple sclerosis and rheumatologic conditions, the Quinoline-3-carboxamides, reduce atherosclerotic plaque burden and complexity in transgenic S100A12 ApoE null mice, but have not been tested with regards to human atherosclerosis. The RAGE axis is an important mediator for inflammation-induced atherosclerosis and S100A12 has emerged as biomarker for human atherosclerosis. Decreasing inflammation by inhibiting S100/calgranulin-mediated activation of RAGE attenuates murine atherosclerosis, and future studies in patients with coronary artery disease are warranted to confirm S100/RAGE as therapeutic target for atherosclerosis. PMID:26515415

Protein kinase CK2 modulates IL-6 expression in inflammatory breast cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drygin, Denis, E-mail: ddrygin@cylenepharma.com; Ho, Caroline B.; Omori, Mayuko

Highlights: Black-Right-Pointing-Pointer We examine the potential cross-talk between CK2 and IL-6. Black-Right-Pointing-Pointer Inhibition of CK2 by siRNA or CX-4945 inhibits expression of IL-6 in models of IBC. Black-Right-Pointing-Pointer Treatment of IBC patient in the clinic with CX-4945 reduces her IL-6 plasma levels. Black-Right-Pointing-Pointer We demonstrate that CK2 is a potential therapeutic target for IL-6 driven diseases. -- Abstract: Inflammatory breast cancer is driven by pro-angiogenic and pro-inflammatory cytokines. One of them Interleukin-6 (IL-6) is implicated in cancer cell proliferation and survival, and promotes angiogenesis, inflammation and metastasis. While IL-6 has been shown to be upregulated by several oncogenes, the mechanismmore » behind this phenomenon is not well characterized. Here we demonstrate that the pleotropic Serine/Threonine kinase CK2 is implicated in the regulation of IL-6 expression in a model of inflammatory breast cancer. We used siRNAs targeted toward CK2 and a selective small molecule inhibitor of CK2, CX-4945, to inhibit the expression and thus suppress the secretion of IL-6 in in vitro as well as in vivo models. Moreover, we report that in a clinical trial, CX-4945 was able to dramatically reduce IL-6 levels in plasma of an inflammatory breast cancer patient. Our data shed a new light on the regulation of IL-6 expression and position CX-4945 and potentially other inhibitors of CK2, for the treatment of IL-6-driven cancers and possibly other diseases where IL-6 is instrumental, including rheumatoid arthritis.« less

The CK2 Kinase Stabilizes CLOCK and Represses Its Activity in the Drosophila Circadian Oscillator

PubMed Central

Szabó, Áron; Papin, Christian; Zorn, Daniela; Ponien, Prishila; Weber, Frank; Raabe, Thomas; Rouyer, François

2013-01-01

Phosphorylation is a pivotal regulatory mechanism for protein stability and activity in circadian clocks regardless of their evolutionary origin. It determines the speed and strength of molecular oscillations by acting on transcriptional activators and their repressors, which form negative feedback loops. In Drosophila, the CK2 kinase phosphorylates and destabilizes the PERIOD (PER) and TIMELESS (TIM) proteins, which inhibit CLOCK (CLK) transcriptional activity. Here we show that CK2 also targets the CLK activator directly. Downregulating the activity of the catalytic α subunit of CK2 induces CLK degradation, even in the absence of PER and TIM. Unexpectedly, the regulatory β subunit of the CK2 holoenzyme is not required for the regulation of CLK stability. In addition, downregulation of CK2α activity decreases CLK phosphorylation and increases per and tim transcription. These results indicate that CK2 inhibits CLK degradation while reducing its activity. Since the CK1 kinase promotes CLK degradation, we suggest that CLK stability and transcriptional activity result from counteracting effects of CK1 and CK2. PMID:24013921

Inositol pyrophosphates mediate the DNA-PK/ATM-p53 cell death pathway by regulating CK2 phosphorylation of Tti1/Tel2

PubMed Central

Rao, Feng; Cha, Jiyoung; Xu, Jing; Xu, Risheng; Vandiver, M. Scott; Tyagi, Richa; Tokhunts, Robert; Koldobskiy, Michael A.; Fu, Chenglai; Barrow, Roxanne; Wu, Mingxuan; Fiedler, Dorothea; Barrow, James C.; Snyder, Solomon H.

2014-01-01

The apoptotic actions of p53 require its phosphorylation by a family of phosphoinositide-3-kinase-related-kinases (PIKKs), which include DNA-PKcs and ATM. These kinases are stabilized by the TTT (Tel2, Tti1, Tti2) co-chaperone family, whose actions are mediated by CK2 phosphorylation. The inositol pyrophosphates, such as 5-diphosphoinositol pentakisphosphate (IP7), are generated by a family of inositol hexakisphosphate kinases (IP6Ks) of which IP6K2 has been implicated in p53-associated cell death. In the present study we report a novel apoptotic signaling cascade linking CK2, TTT, the PIKKs, and p53. We demonstrate that IP7, formed by IP6K2, binds CK2 to enhance its phosphorylation of the TTT complex thereby stabilizing DNA-PKcs and ATM. This process stimulates p53 phosphorylation at serine-15 to activate the cell death program in human cancer cells and in murine B cells. PMID:24657168

Protein kinase CK2 interacts with adiponectin receptor 1 and participates in adiponectin signaling.

PubMed

Heiker, John T; Wottawah, Cornelia M; Juhl, Cathleen; Kosel, David; Mörl, Karin; Beck-Sickinger, Annette G

2009-06-01

Adiponectin is an adipokine with anti-atherogenic, anti-diabetic and insulin sensitizing properties. Its effects on energy homeostasis, glucose and lipid metabolism are mediated by two ubiquitously expressed seven-transmembrane receptors, AdipoR1 and -R2. With the exception of APPL1 and RACK1, no intracellular binding partners of adiponectin receptors are reported and thus signaling pathways downstream of these receptors remain largely unknown. To incorporate adiponectins protective potential in drug development it is essential to understand adiponectin signaling cascades in detail. A yeast two-hybrid approach employing AdipoR1s cytoplasmatic N-terminus led to the identification of the regulatory subunit of protein kinase CK2. We confirmed the interaction in co-immunoprecipitation, ELISA experiments and co-localization analysis in mammalian cells. Furthermore we could localize the interaction site in an N-terminal basic region close to the transmembrane domain. In adiponectin stimulation experiments of C2C12 mouse myotubes and MCF7 cells incorporating CK2 inhibitor 2-dimethylamino-4,5,6,7-tetrabromo-1H-benz-imidazole (DMAT) we found a modulator role of CK2 in adiponectin signaling. Accordingly we identified the regulatory subunit of protein kinase CK2 as a novel intracellular partner of AdipoR1 and have strong evidence of CK2 as an effector molecule in adiponectin signaling. Since CK2 is involved in signaling cascades of other adipokines and hormones, e.g. leptin and insulin, our findings suggest a possible key function in crosstalk between adiponectin and insulin signaling pathways and could provide further insight into the anti-diabetic effects of adiponectin.

HIV-1 Triggers WAVE2 Phosphorylation in Primary CD4 T Cells and Macrophages, Mediating Arp2/3-dependent Nuclear Migration*

PubMed Central

Spear, Mark; Guo, Jia; Turner, Amy; Yu, Dongyang; Wang, Weifeng; Meltzer, Beatrix; He, Sijia; Hu, Xiaohua; Shang, Hong; Kuhn, Jeffrey; Wu, Yuntao

2014-01-01

The human immunodeficiency virus type 1 (HIV-1) initiates receptor signaling and early actin dynamics during viral entry. This process is required for viral infection of primary targets such as resting CD4 T cells. WAVE2 is a component of a multiprotein complex linking receptor signaling to dynamic remodeling of the actin cytoskeleton. WAVE2 directly activates Arp2/3, leading to actin nucleation and filament branching. Although several bacterial and viral pathogens target Arp2/3 for intracellular mobility, it remains unknown whether HIV-1 actively modulates the Arp2/3 complex through virus-mediated receptor signal transduction. Here we report that HIV-1 triggers WAVE2 phosphorylation at serine 351 through gp120 binding to the chemokine coreceptor CXCR4 or CCR5 during entry. This phosphorylation event involves both Gαi-dependent and -independent pathways, and is conserved both in X4 and R5 viral infection of resting CD4 T cells and primary macrophages. We further demonstrate that inhibition of WAVE2-mediated Arp2/3 activity through stable shRNA knockdown of Arp3 dramatically diminished HIV-1 infection of CD4 T cells, preventing viral nuclear migration. Inhibition of Arp2/3 through a specific inhibitor, CK548, also drastically inhibited HIV-1 nuclear migration and infection of CD4 T cells. Our results suggest that Arp2/3 and the upstream regulator, WAVE2, are essential co-factors hijacked by HIV for intracellular migration, and may serve as novel targets to prevent HIV transmission. PMID:24415754

HIV-1 triggers WAVE2 phosphorylation in primary CD4 T cells and macrophages, mediating Arp2/3-dependent nuclear migration.

PubMed

Spear, Mark; Guo, Jia; Turner, Amy; Yu, Dongyang; Wang, Weifeng; Meltzer, Beatrix; He, Sijia; Hu, Xiaohua; Shang, Hong; Kuhn, Jeffrey; Wu, Yuntao

2014-03-07

The human immunodeficiency virus type 1 (HIV-1) initiates receptor signaling and early actin dynamics during viral entry. This process is required for viral infection of primary targets such as resting CD4 T cells. WAVE2 is a component of a multiprotein complex linking receptor signaling to dynamic remodeling of the actin cytoskeleton. WAVE2 directly activates Arp2/3, leading to actin nucleation and filament branching. Although several bacterial and viral pathogens target Arp2/3 for intracellular mobility, it remains unknown whether HIV-1 actively modulates the Arp2/3 complex through virus-mediated receptor signal transduction. Here we report that HIV-1 triggers WAVE2 phosphorylation at serine 351 through gp120 binding to the chemokine coreceptor CXCR4 or CCR5 during entry. This phosphorylation event involves both Gαi-dependent and -independent pathways, and is conserved both in X4 and R5 viral infection of resting CD4 T cells and primary macrophages. We further demonstrate that inhibition of WAVE2-mediated Arp2/3 activity through stable shRNA knockdown of Arp3 dramatically diminished HIV-1 infection of CD4 T cells, preventing viral nuclear migration. Inhibition of Arp2/3 through a specific inhibitor, CK548, also drastically inhibited HIV-1 nuclear migration and infection of CD4 T cells. Our results suggest that Arp2/3 and the upstream regulator, WAVE2, are essential co-factors hijacked by HIV for intracellular migration, and may serve as novel targets to prevent HIV transmission.

Protein kinase CK2 inhibitors: a patent review.

PubMed

Cozza, Giorgio; Pinna, Lorenzo A; Moro, Stefano

2012-09-01

CK2 is a pleiotropic, ubiquitous and constitutively active protein kinase, localized in both cytosolic and nuclear compartments, where it catalyzes the phosphorylation of hundreds of proteins. CK2 is generally described as a tetramer composed of two catalytic (α and/or α') and two regulatory subunits (β), however, the free α/α' subunits are catalytically active by themselves. CK2 plays a key role in several physiological and pathological processes and has been connected to many neoplastic, inflammatory, autoimmune and infectious disorders. In the last 20 years, several inhibitors of CK2 have been discovered though only one of these, CX-4945, has recently entered into Phase II clinical trials as potential anticancer drug. The main objective of the present review is to describe the development of CK2 activity modulators over the years according to the timeline of their patent registration. CK2 was discovered in 1954, but the first patent on CK2 modulators was deposited only 50 years later, in 2004. However, in the last 5 years an increasing number of patents on CK2 inhibitors have been registered, reflecting an increased interest in this kind of drug candidates and their possible therapeutic applications.

MOLECULAR MECHANISM OF HUMAN NRF2 ACTIVATION AND DEGRADATION: ROLE OF SEQUENTIAL PHOSPHORYLATION BY PROTEIN KINASE CK2

PubMed Central

Pi, Jingbo; Bai, Yushi; Reece, Jeffrey M.; Williams, Jason; Liu, Dianxin; Freeman, Michael L.; Fahl, William E.; Shugar, David; Liu, Jie; Qu, Wei; Collins, Sheila; Waalkes, Michael P.

2007-01-01

Nrf2 is a key transcription factor in the cellular response to oxidative stress. In this study we first identify two phosphorylated forms of endogenous human Nrf2 after chemically-induced oxidative stress and provide evidence that protein kinase CK2-mediated sequential phosphorylation plays potential role in Nrf2 activation and degradation. Human Nrf2 has a predicted molecular mass of 66 kDa. However, immunoblots showed that two bands at 98 and 118 kDa, which are identified as phosphorylated forms, are increased in response to Nrf2 inducers. In addition, human Nrf2 was found to be a substrate for CK2 which mediated two steps of phosphorylation, resulting in two forms of Nrf2 migrating with differing Mr at 98 kDa (Nrf2–98) and 118 kDa (Nrf2–118). Our results support a role in which calmodulin binding regulates CK2 activity, in that cold (25 °C) in Ca2+-free media (cold/Ca2+-free) decreased both cellular calcium levels and CK2-calmodulin binding and induced Nrf2–118 formation, the latter of which was prevented by CK2 specific inhibitors. Gel-shift assays showed that the Nrf2–118 generated under cold/Ca2+-free conditions does not bind to the antioxidant response element, indicating that Nrf2–98 has transcriptional activity. In contrast, Nrf2–118 is more susceptible to degradation. These results provide evidence for phosphorylation by CK2 as a critical controlling factor in Nrf2-mediated cellular antioxidant response. PMID:17512459

Casein kinase 2 inhibition impairs spontaneous and oxytocin-induced contractions in late pregnant mouse uterus.

PubMed

Suhas, K S; Parida, Subhashree; Gokul, Chandrasekaran; Srivastava, Vivek; Prakash, E; Chauhan, Sakshi; Singh, Thakur Uttam; Panigrahi, Manjit; Telang, Avinash G; Mishra, Santosh K

2018-05-01

What is the central question of this study? Does the inhibition of the protein kinase casein kinase 2 (CK2) alter the uterine contractility? What is the main finding and its importance? Inhibition of CK2 impaired the spontaneous and oxytocin-induced contractility in late pregnant mouse uterus. This finding suggests that CK2 is a novel pathway mediating oxytocin-induced contractility in the uterus and thus opens up the possibility for this class of drugs to be developed as a new class of tocolytics. The protein kinase casein kinase 2 (CK2) is a ubiquitously expressed serine or threonine kinase known to phosphorylate a number of substrates. The aim of this study was to assess the effect of CK2 inhibition on spontaneous and oxytocin-induced uterine contractions in 19 day pregnant mice. The CK2 inhibitor CX-4945 elicited a concentration-dependent relaxation in late pregnant mouse uterus. CX-4945 and another selective CK2 inhibitor, apigenin, also inhibited the oxytocin-induced contractile response in late pregnant uterine tissue. Apigenin also blunted the prostaglandin F 2α response, but CX-4945 did not. Casein kinase 2 was located in the lipid raft fractions of the cell membrane, and disruption of lipid rafts was found to reverse its effect. The results of the present study suggest that CK2, located in lipid rafts of the cell membrane, is an active regulator of spontaneous and oxytocin-induced uterine contractions in the late pregnant mouse. © 2018 The Authors. Experimental Physiology © 2018 The Physiological Society.

Protein kinase CK2 enables regulatory T cells to suppress excessive TH2 responses in vivo.

PubMed

Ulges, Alexander; Klein, Matthias; Reuter, Sebastian; Gerlitzki, Bastian; Hoffmann, Markus; Grebe, Nadine; Staudt, Valérie; Stergiou, Natascha; Bohn, Toszka; Brühl, Till-Julius; Muth, Sabine; Yurugi, Hajime; Rajalingam, Krishnaraj; Bellinghausen, Iris; Tuettenberg, Andrea; Hahn, Susanne; Reißig, Sonja; Haben, Irma; Zipp, Frauke; Waisman, Ari; Probst, Hans-Christian; Beilhack, Andreas; Buchou, Thierry; Filhol-Cochet, Odile; Boldyreff, Brigitte; Breloer, Minka; Jonuleit, Helmut; Schild, Hansjörg; Schmitt, Edgar; Bopp, Tobias

2015-03-01

The quality of the adaptive immune response depends on the differentiation of distinct CD4(+) helper T cell subsets, and the magnitude of an immune response is controlled by CD4(+)Foxp3(+) regulatory T cells (Treg cells). However, how a tissue- and cell type-specific suppressor program of Treg cells is mechanistically orchestrated has remained largely unexplored. Through the use of Treg cell-specific gene targeting, we found that the suppression of allergic immune responses in the lungs mediated by T helper type 2 (TH2) cells was dependent on the activity of the protein kinase CK2. Genetic ablation of the β-subunit of CK2 specifically in Treg cells resulted in the proliferation of a hitherto-unexplored ILT3(+) Treg cell subpopulation that was unable to control the maturation of IRF4(+)PD-L2(+) dendritic cells required for the development of TH2 responses in vivo.

S100A8+ stroma cells predict a good prognosis and inhibit aggressiveness in colorectal carcinoma.

PubMed

Li, Si; Xu, Fangying; Li, Hui; Zhang, Jing; Zhong, Anjing; Huang, Bin; Lai, Maode

2017-01-01

Gene microarray and bioinformatic analysis showed that S100A8 was more abundant in the stroma surrounding tumor buddings (TBs) than in the stroma surrounding primary tumor cells in colorectal carcinomas. Here, S100A8 + cells in 419 colorectal carcinoma samples were stained by immunohistochemistry and counted using Image-pro plus 6.0. TBs were also counted and biomarkers associated with the epithelial-mesenchymal transition and apoptosis were assessed by immunohistochemistry. We evaluated the association between S100A8 + cells and clinico-pathological variables as well as survival. Migration and invasion as well as biomarkers of the epithelial-mesenchymal transition and apoptosis were tested in CRC cells, treated with graded concentrations of recombinant human S100A8 protein. We found that the density of S100A8 + cells in the tumor invasive front (S100A8 + TIF ) clearly distinguished patients with 5-y survival from those who did not survive ( p = 0.01). The S100A8 + -associated tumor budding (SATB) index determined by the S100A8 + TIF and TB was an independent predictor of overall survival ( p = 0.001) other than the S100A8 + TIF or TB alone. Migration and invasion properties of CRC cells were inhibited by recombinant human S100A8 treatment. The particular S100A8 + cells in the stroma were associated with important biomarkers of the epithelial-mesenchymal transition (E-cadherin and SNAIL) and apoptosis (BCL2). In conclusion, S100A8 + cells in the stroma predict a good prognosis in colorectal carcinoma. An index combining S100A8 + cells and TB independently predicts survival. Recombinant human S100A8 inhibited CRC cell migration and invasion, which was involved in epithelial-mesenchymal transition (E-cadherin and SNAIL) and apoptosis (BCL2).

S100A8+ stroma cells predict a good prognosis and inhibit aggressiveness in colorectal carcinoma

PubMed Central

Li, Si; Xu, Fangying; Li, Hui; Zhang, Jing; Zhong, Anjing; Huang, Bin; Lai, Maode

2017-01-01

ABSTRACT Gene microarray and bioinformatic analysis showed that S100A8 was more abundant in the stroma surrounding tumor buddings (TBs) than in the stroma surrounding primary tumor cells in colorectal carcinomas. Here, S100A8+ cells in 419 colorectal carcinoma samples were stained by immunohistochemistry and counted using Image-pro plus 6.0. TBs were also counted and biomarkers associated with the epithelial–mesenchymal transition and apoptosis were assessed by immunohistochemistry. We evaluated the association between S100A8+ cells and clinico-pathological variables as well as survival. Migration and invasion as well as biomarkers of the epithelial–mesenchymal transition and apoptosis were tested in CRC cells, treated with graded concentrations of recombinant human S100A8 protein. We found that the density of S100A8+ cells in the tumor invasive front (S100A8+TIF) clearly distinguished patients with 5-y survival from those who did not survive (p = 0.01). The S100A8+-associated tumor budding (SATB) index determined by the S100A8+TIF and TB was an independent predictor of overall survival (p = 0.001) other than the S100A8+TIF or TB alone. Migration and invasion properties of CRC cells were inhibited by recombinant human S100A8 treatment. The particular S100A8+ cells in the stroma were associated with important biomarkers of the epithelial–mesenchymal transition (E-cadherin and SNAIL) and apoptosis (BCL2). In conclusion, S100A8+ cells in the stroma predict a good prognosis in colorectal carcinoma. An index combining S100A8+ cells and TB independently predicts survival. Recombinant human S100A8 inhibited CRC cell migration and invasion, which was involved in epithelial–mesenchymal transition (E-cadherin and SNAIL) and apoptosis (BCL2). PMID:28197382

Protein Kinase CK2 Content in GL261 Mouse Glioblastoma.

PubMed

Ferrer-Font, Laura; Alcaraz, Estefania; Plana, Maria; Candiota, Ana Paula; Itarte, Emilio; Arús, Carles

2016-07-01

Glioblastoma (GBM) is the most prevalent and aggressive human glial tumour with a median survival of 14-15 months. Temozolomide (TMZ) is the standard chemotherapeutic choice for GBM treatment. Unfortunately, chemoresistence always ensues with concomitant tumour regrowth. Protein kinase CK2 (CK2) contributes to tumour development, proliferation, and suppression of apoptosis in cancer and it is overexpressed in human GBM. Targeting CK2 in GBM treatment may benefit patients. With this translational perspective in mind, we have studied the CK2 expression level by Western blot analysis in a preclinical model of GBM: GL261 cells growing orthotopically in C57BL/6 mice. The expression level of the CK2 catalytic subunit (CK2α) was higher in tumour (about 4-fold) and in contralateral brain parenchyma (more than 2-fold) than in normal brain parenchyma (p < 0.05). In contrast, no significant changes were found in CK2 regulatory subunit (CK2β) expression, suggesting an increased unbalance of CK2α/CK2β in GL261 tumours with respect to normal brain parenchyma, in agreement with a differential role of these two subunits in tumours.

Blockade of S100A3 activity inhibits murine hair growth.

PubMed

Guan, W; Deng, Q; Yu, X L; Yuan, Y S; Gao, J; Li, J J; Zhou, L; Xia, P; Han, G Y Q; Han, W; Yu, Y

2015-10-28

Using mouse gene expression microarray analysis, we obtained dynamic expression profiles of the whole genome in a depilation-induced hair growth mouse model. S100A3 expression increased during the anagen phase and returned to normal during the telogen phase. The effects of S100A3 blockade on the hair growth cycle were examined in mice after subcutaneous injection of an anti-mouse S100A3 antibody. Protein localization of S100A3 was confined to the hair shafts during the anagen phase and the sebaceous glands during the telogen phase. S100A3 blockade delayed hair follicle entry into the anagen phase, decreased hair elongation, and reduced the number of hair follicles in the subcutis, which correlated with the downregulated expression of hair growth induction-related genes in vivo. The present study demonstrates that anti-S100A3 antibody inhibits mouse hair growth, suggesting that S100A3 can be used as a target for hair loss treatment.

Calcium-binding protein S100A4 confers mesenchymal progenitor cell fibrogenicity in idiopathic pulmonary fibrosis

PubMed Central

Xia, Hong; Gilbertsen, Adam; Herrera, Jeremy; Racila, Emilian; Peterson, Mark; Griffin, Timothy; Benyumov, Alexey; Yang, Libang; Bitterman, Peter B.; Henke, Craig A.

2017-01-01

Idiopathic pulmonary fibrosis (IPF) is a progressive disease with a prevalence of 1 million persons worldwide. The fibrosis spreads from affected alveoli into contiguous alveoli and leads to death by asphyxiation. We previously discovered that the IPF lung harbors fibrogenic mesenchymal progenitor cells (MPCs) that serve as a cell of origin for disease-mediating myofibroblasts. In a prior genomewide transcriptional analysis, we found that IPF MPCs displayed increased expression of S100 calcium-binding A4 (S100A4), a protein linked to cancer cell proliferation and invasiveness. Here, we have examined whether S100A4 mediates MPC fibrogenicity. Ex vivo analysis revealed that IPF MPCs had increased levels of nuclear S100A4, which interacts with L-isoaspartyl methyltransferase to promote p53 degradation and MPC self-renewal. In vivo, injection of human IPF MPCs converted a self-limited bleomycin-induced mouse model of lung fibrosis to a model of persistent fibrosis in an S100A4-dependent manner. S100A4 gain of function was sufficient to confer fibrotic properties to non-IPF MPCs. In IPF tissue, fibroblastic foci contained cells expressing Ki67 and the MPC markers SSEA4 and S100A4. The expression colocalized in an interface region between myofibroblasts in the focus core and normal alveolar structures, defining this region as an active fibrotic front. Our findings indicate that IPF MPCs are intrinsically fibrogenic and that S100A4 confers MPCs with fibrogenicity. PMID:28530639

Attenuation of cancer-initiating cells stemness properties by abrogating S100A4 calcium binding ability in head and neck cancers.

PubMed

Cheng, Li-Hao; Hung, Kai-Feng; Huang, Tung-Fu; Hsieh, Hsin-Pei; Wang, Shu-Ying; Huang, Chih-Yang; Lo, Jeng-Fan

2016-11-29

S100A4 is a calcium-binding protein capable of promoting epithelial-mesenchymal transition. Previously, we have demonstrated that S100A4 is required to sustain the head and neck cancer-initiating cells (HN-CICs) subpopulation. In this study, to further investigate the molecular mechanism, we established the head and neck squamous cell carcinoma (HNSCC) cell lines stably expressing mutant S100A4 proteins with defective calcium-binding sites on either N-terminal (NM) or C-terminal (CM), or a deletion of the last 15 amino-acid residues (CD). We showed that the NM, CM and CD harboring sphere cells that were enriched with HN-CICs population exhibited impaired stemness and malignant properties in vitro, as well as reduced tumor growth ability in vivo. Mechanistically, we demonstrated that mutant S100A4 proteins decreased the promoter activity of Nanog, likely through inhibition of p53. Moreover, the biophysical analyses of purified recombinant mutant S100A4 proteins suggest that both NM and CM mutant S100A4 were very similar to the WT S100A4 with subtle difference on the secondary structure, and that the CD mutant protein displayed the unexpected monomeric form in the solution phase.Taken together, our results suggest that both the calcium-binding ability and the C-terminal region of S100A4 are important for HN-CICs to sustain its stemness property and malignancy, and that the mechanism could be mediated by repressing p53 and subsequently activating the Nanog expression.

S100A8/A9 and S100A9 reduce acute lung injury.

PubMed

Hiroshima, Yuka; Hsu, Kenneth; Tedla, Nicodemus; Wong, Sze Wing; Chow, Sharron; Kawaguchi, Naomi; Geczy, Carolyn L

2017-05-01

S100A8 and S100A9 are myeloid cell-derived proteins that are elevated in several types of inflammatory lung disorders. Pro- and anti-inflammatory properties are reported and these proteins are proposed to activate TLR4. S100A8 and S100A9 can function separately, likely through distinct receptors but a systematic comparison of their effects in vivo are limited. Here we assess inflammation in murine lung following S100A9 and S100A8/A9 inhalation. Unlike S100A8, S100A9 promoted mild neutrophil and lymphocyte influx, possibly mediated in part, by increased mast cell degranulation and selective upregulation of some chemokine genes, particularly CXCL-10. S100 proteins did not significantly induce proinflammatory mediators including TNF-α, interleukin-1β (IL-1β), IL-6 or serum amyloid A3 (SAA3). In contrast to S100A8, neither preparation induced S100A8 or IL-10 mRNA/protein in airway epithelial cells, or in tracheal epithelial cells in vitro. Like S100A8, S100A9 and S100A8/A9 reduced neutrophil influx in acute lung injury provoked by lipopolysaccharide (LPS) challenge but were somewhat less inhibitory, possibly because of differential effects on expression of some chemokines, IL-1β, SAA3 and IL-10. Novel common pathways including increased induction of an NAD + -dependent protein deacetylase sirtuin-1 that may reduce NF-κB signalling, and increased STAT3 activation may reduce LPS activation. Results suggest a role for these proteins in normal homeostasis and protective mechanisms in the lung.

S100A8/A9 and S100A9 reduce acute lung injury

PubMed Central

Hiroshima, Yuka; Hsu, Kenneth; Tedla, Nicodemus; Wong, Sze Wing; Chow, Sharron; Kawaguchi, Naomi; Geczy, Carolyn L

2017-01-01

S100A8 and S100A9 are myeloid cell-derived proteins that are elevated in several types of inflammatory lung disorders. Pro- and anti-inflammatory properties are reported and these proteins are proposed to activate TLR4. S100A8 and S100A9 can function separately, likely through distinct receptors but a systematic comparison of their effects in vivo are limited. Here we assess inflammation in murine lung following S100A9 and S100A8/A9 inhalation. Unlike S100A8, S100A9 promoted mild neutrophil and lymphocyte influx, possibly mediated in part, by increased mast cell degranulation and selective upregulation of some chemokine genes, particularly CXCL-10. S100 proteins did not significantly induce proinflammatory mediators including TNF-α, interleukin-1β (IL-1β), IL-6 or serum amyloid A3 (SAA3). In contrast to S100A8, neither preparation induced S100A8 or IL-10 mRNA/protein in airway epithelial cells, or in tracheal epithelial cells in vitro. Like S100A8, S100A9 and S100A8/A9 reduced neutrophil influx in acute lung injury provoked by lipopolysaccharide (LPS) challenge but were somewhat less inhibitory, possibly because of differential effects on expression of some chemokines, IL-1β, SAA3 and IL-10. Novel common pathways including increased induction of an NAD+-dependent protein deacetylase sirtuin-1 that may reduce NF-κB signalling, and increased STAT3 activation may reduce LPS activation. Results suggest a role for these proteins in normal homeostasis and protective mechanisms in the lung. PMID:28074060

Caffeine protects against experimental acute pancreatitis by inhibition of inositol 1,4,5-trisphosphate receptor-mediated Ca2+ release

PubMed Central

Huang, Wei; Cane, Matthew C; Mukherjee, Rajarshi; Szatmary, Peter; Zhang, Xiaoying; Elliott, Victoria; Ouyang, Yulin; Chvanov, Michael; Latawiec, Diane; Wen, Li; Booth, David M; Haynes, Andrea C; Petersen, Ole H; Tepikin, Alexei V; Criddle, David N

2017-01-01

Objective Caffeine reduces toxic Ca2+ signals in pancreatic acinar cells via inhibition of inositol 1,4,5-trisphosphate receptor (IP3R)-mediated signalling, but effects of other xanthines have not been evaluated, nor effects of xanthines on experimental acute pancreatitis (AP). We have determined effects of caffeine and its xanthine metabolites on pancreatic acinar IP3R-mediated Ca2+ signalling and experimental AP. Design Isolated pancreatic acinar cells were exposed to secretagogues, uncaged IP3 or toxins that induce AP and effects of xanthines, non-xanthine phosphodiesterase (PDE) inhibitors and cyclic adenosine monophosphate and cyclic guanosine monophosphate (cAMP/cGMP) determined. The intracellular cytosolic calcium concentration ([Ca2+]C), mitochondrial depolarisation and necrosis were assessed by confocal microscopy. Effects of xanthines were evaluated in caerulein-induced AP (CER-AP), taurolithocholic acid 3-sulfate-induced AP (TLCS-AP) or palmitoleic acid plus ethanol-induced AP (fatty acid ethyl ester AP (FAEE-AP)). Serum xanthines were measured by liquid chromatography-mass spectrometry. Results Caffeine, dimethylxanthines and non-xanthine PDE inhibitors blocked IP3-mediated Ca2+ oscillations, while monomethylxanthines had little effect. Caffeine and dimethylxanthines inhibited uncaged IP3-induced Ca2+ rises, toxin-induced Ca2+ release, mitochondrial depolarisation and necrotic cell death pathway activation; cAMP/cGMP did not inhibit toxin-induced Ca2+ rises. Caffeine significantly ameliorated CER-AP with most effect at 25 mg/kg (seven injections hourly); paraxanthine or theophylline did not. Caffeine at 25 mg/kg significantly ameliorated TLCS-AP and FAEE-AP. Mean total serum levels of dimethylxanthines and trimethylxanthines peaked at >2 mM with 25 mg/kg caffeine but at <100 µM with 25 mg/kg paraxanthine or theophylline. Conclusions Caffeine and its dimethylxanthine metabolites reduced pathological IP3R-mediated pancreatic acinar Ca2

Impact of creatine kinase correction on the predictive value of S-100B after mild traumatic brain injury.

PubMed

Bazarian, Jeffrey J; Beck, Christopher; Blyth, Brian; von Ahsen, Nicolas; Hasselblatt, Martin

2006-01-01

To validate a correction factor for the extracranial release of the astroglial protein, S-100B, based on concomitant creatine kinase (CK) levels. The CK- S-100B relationship in non-head injured marathon runners was used to derive a correction factor for the extracranial release of S-100B. This factor was then applied to a separate cohort of 96 mild traumatic brain injury (TBI) patients in whom both CK and S-100B levels were measured. Corrected S-100B was compared to uncorrected S-100B for the prediction of initial head CT, three-month headache and three-month post concussive syndrome (PCS). Corrected S-100B resulted in a statistically significant improvement in the prediction of 3-month headache (area under curve [AUC] 0.46 vs 0.52, p=0.02), but not PCS or initial head CT. Using a cutoff that maximizes sensitivity (> or = 90%), corrected S-100B improved the prediction of initial head CT scan (negative predictive value from 75% [95% CI, 2.6%, 67.0%] to 96% [95% CI: 83.5%, 99.8%]). Although S-100B is overall poorly predictive of outcome, a correction factor using CK is a valid means of accounting for extracranial release. By increasing the proportion of mild TBI patients correctly categorized as low risk for abnormal head CT, CK-corrected S100-B can further reduce the number of unnecessary brain CT scans performed after this injury.

Cyclin A-mediated inhibition of intra-Golgi transport requires p34cdc2.

PubMed

Mackay, D; Kieckbusch, R; Adamczewski, J; Warren, G

1993-12-28

An in vitro assay was used to study the role of p34cdc2 in cyclin A-mediated vesicular transport inhibition. It was shown that the S-phase kinase p33cdk2 reduced the effect of cyclin A on transport assays performed with sHeLa cytosol, even though histone kinase was strongly activated. Also, transport with FT210 cytosol (which is temperature-sensitive for p34cdc2) was inhibited by cyclin A only at the permissive temperature. However, the phosphatase inhibitor microcystin inhibited transport without any requirement for p34cdc2 activity. These results show that transport is inhibited by cyclin A via p34cdc2, and also by another kinase, possibly downstream of p34cdc2.

P2X1 receptor-mediated inhibition of the proliferation of human coronary smooth muscle cells involving the transcription factor NR4A1.

PubMed

Hinze, Annette Viktoria; Mayer, Peter; Harst, Anja; von Kügelgen, Ivar

2013-12-01

Adenine nucleotides acting at P2X1 receptors are potent vasoconstrictors. Recently, we demonstrated that activation of adenosine A2B receptors on human coronary smooth muscle cells inhibits cell proliferation by the induction of the nuclear receptor subfamily 4, group A, member 1 (NR4A1; alternative notation Nur77). In the present study, we searched for long-term effects mediated by P2X1 receptors by analyzing receptor-mediated changes in cell proliferation and in the expression of NR4A1. Cultured human coronary smooth muscle cells were treated with selective receptor ligands. Effects on proliferation were determined by counting cells and measuring changes in impedance. The induction of transcription factors was assessed by qPCR. The P2X receptor agonist α,β-methylene-ATP and its analog β,γ-methylene-ATP inhibited cell proliferation by about 50 % after 5 days in culture with half-maximal concentrations of 0.3 and 0.08 μM, respectively. The effects were abolished or markedly attenuated by the P2X1 receptor antagonist NF449 (carbonylbis-imino-benzene-triylbis-(carbonylimino)tetrakis-benzene-1,3-disulfonic acid; 100 nM and 1 μM). α,β-methylene-ATP and β,γ-methylene-ATP applied for 30 min to 4 h increased the expression of NR4A1; NF449 blocked or attenuated this effect. Small interfering RNA directed against NR4A1 diminished the antiproliferative effects of α,β-methylene-ATP and β,γ-methylene-ATP. α,β-methylene-ATP (0.1 to 30 μM) decreased migration of cultured human coronary smooth muscle cells in a chamber measuring changes in impedance; NF449 blocked the effect. In conclusion, our results demonstrate for the first time that adenine nucleotides acting at P2X1 receptors inhibit the proliferation of human coronary smooth muscle cells via the induction of the early gene NR4A1.

Transcriptional activity and DNA binding of heat shock factor-1 involve phosphorylation on threonine 142 by CK2.

PubMed

Soncin, Fabrice; Zhang, Xinfeng; Chu, Boyang; Wang, Xiaozhe; Asea, Alexzander; Ann Stevenson, Mary; Sacks, David B; Calderwood, Stuart K

2003-04-04

Heat shock factor-1 (HSF-1) is the regulator of hsp molecular chaperone transcription, although the intracellular mechanisms involved in HSF-1 activation have not been fully elucidated. As HSF1 is activated by heat shock simultaneously with the nuclear translocation of the protein kinase CK2, we have investigated the role of CK2 in HSF1 activation. We demonstrate that HSF-1 is phosphorylated by CK2 on both serine and threonine residues and has characterized a phosphorylation site at threonine 142. Mutation of Thr-142 to alanine (T142A) inhibits trans-activation of the HSP70 gene by HSF1 and in addition inhibits the accumulation of HSF-1 competent to bind heat shock elements in the nucleus. HSF1 activation by heat is correlated with the thermal activation of nuclear CK2 and overexpression of CK2 activates HSF1. Phosphorylation by CK2 on threonine 142 may therefore be an essential step in the thermal activation of latent HSF1 by stresses.

Rotenone Induction of Hydrogen Peroxide Inhibits mTOR-mediated S6K1 and 4E-BP1/eIF4E Pathways, Leading to Neuronal Apoptosis

PubMed Central

Zhou, Qian; Liu, Chunxiao; Liu, Wen; Zhang, Hai; Zhang, Ruijie; Liu, Jia; Zhang, Jinfei; Xu, Chong; Liu, Lei; Huang, Shile; Chen, Long

2015-01-01

Rotenone, a common pesticide and inhibitor of mitochondrial complex I, induces loss of dopaminergic neurons and consequential aspects of Parkinson’s disease (PD). However, the exact mechanism of rotenone neurotoxicity is not fully elucidated. Here, we show that rotenone induced reactive oxygen species (ROS), leading to apoptotic cell death in PC12 cells and primary neurons. Pretreatment with catalase (CAT), a hydrogen peroxide-scavenging enzyme, attenuated rotenone-induced ROS and neuronal apoptosis, implying hydrogen peroxide (H2O2) involved, which was further verified by imaging intracellular H2O2 using a peroxide-selective probe H2DCFDA. Using thenoyltrifluoroacetone (TTFA), antimycin A, or Mito-TEMPO, we further demonstrated rotenone-induced mitochondrial H2O2-dependent neuronal apoptosis. Rotenone dramatically inhibited mTOR-mediated phosphorylation of S6K1 and 4E-BP1, which was also attenuated by CAT in the neuronal cells. Of interest, ectopic expression of wild-type mTOR or constitutively active S6K1, or downregulation of 4E-BP1 partially prevented rotenone-induced H2O2 and cell apoptosis. Furthermore, we noticed that rotenone-induced H2O2 was linked to the activation of caspase-3 pathway. This was evidenced by the finding that pretreatment with CAT partially blocked rotenone-induced cleavages of caspase-3 and poly (ADP-ribose) polymerase. Of note, zVAD-fmk, a pan caspase inhibitor, only partially prevented rotenone-induced apoptosis in PC12 cells and primary neurons. Expression of mTOR-wt, S6K1-ca, or silencing 4E-BP1 potentiated zVAD-fmk protection against rotenone-induced apoptosis in the cells. The results indicate that rotenone induction of H2O2 inhibits mTOR-mediated S6K1 and 4E-BP1/eIF4E pathways, resulting in caspase-dependent and -independent apoptosis in neuronal cells. Our findings suggest that rotenone-induced neuronal loss in PD may be prevented by activating mTOR signaling and/or administering antioxidants. PMID:25304210

S100A8 and S100A9 Promotes Invasion and Migration through p38 Mitogen-Activated Protein Kinase-Dependent NF-κB Activation in Gastric Cancer Cells

PubMed Central

Kwon, Chae Hwa; Moon, Hyun Jung; Park, Hye Ji; Choi, Jin Hwa; Park, Do Youn

2013-01-01

S100A8 and S100A9 (S100A8/A9) are low-molecular weight members of the S100 family of calcium-binding proteins. Recent studies have reported S100A8/A9 promote tumorigenesis. We have previously reported that S100A8/A9 is mostly expressed in stromal cells and inflammatory cells between gastric tumor cells. However, the role of environmental S100A8/A9 in gastric cancer has not been defined. We observed in the present study the effect of S100A8/A9 on migration and invasion of gastric cancer cells. S100A8/A9 treatment increased migration and invasionat lower concentrations that did not affect cell proliferation and cell viability. S100A8/A9 caused activation of p38 mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB). The phosphorylation of p38 MAPK was not affected by the NF-κB inhibitor Bay whereas activation of NF-κB was blocked by p38 MAPK inhibitor SB203580, indicating that S100A8/A9-induced NF-κB activation is mediated by phosphorylation of p38 MAPK. S100A8/A9-induced cell migration and invasion was inhibited by SB203580 and Bay, suggesting that activation of p38 MAPK and NF-κB is involved in the S100A8/A9 induced cell migration and invasion. S100A8/A9 caused an increase in matrix metalloproteinase 2 (MMP2) and MMP12 expression, which were inhibited by SB203580 and Bay. S100A8/A9-induced cell migration and invasion was inhibited by MMP2 siRNA and MMP12 siRNA, indicating that MMP2 and MMP12 is related to the S100A8/A9 induced cell migration and invasion. Taken together, these results suggest that S100A8/A9 promotes cell migration and invasion through p38 MAPK-dependent NF-κB activation leading to an increase of MMP2 and MMP12 in gastric cancer. PMID:23456298

Obesity-Linked Phosphorylation of SIRT1 by Casein Kinase 2 Inhibits Its Nuclear Localization and Promotes Fatty Liver.

PubMed

Choi, Sung E; Kwon, Sanghoon; Seok, Sunmi; Xiao, Zhen; Lee, Kwan-Woo; Kang, Yup; Li, Xiaoling; Shinoda, Kosaku; Kajimura, Shingo; Kemper, Byron; Kemper, Jongsook Kim

2017-08-01

Sirtuin1 (SIRT1) deacetylase delays and improves many obesity-related diseases, including nonalcoholic fatty liver disease (NAFLD) and diabetes, and has received great attention as a drug target. SIRT1 function is aberrantly low in obesity, so understanding the underlying mechanisms is important for drug development. Here, we show that obesity-linked phosphorylation of SIRT1 inhibits its function and promotes pathological symptoms of NAFLD. In proteomic analysis, Ser-164 was identified as a major serine phosphorylation site in SIRT1 in obese, but not lean, mice, and this phosphorylation was catalyzed by casein kinase 2 (CK2), the levels of which were dramatically elevated in obesity. Mechanistically, phosphorylation of SIRT1 at Ser-164 substantially inhibited its nuclear localization and modestly affected its deacetylase activity. Adenovirus-mediated liver-specific expression of SIRT1 or a phosphor-defective S164A-SIRT1 mutant promoted fatty acid oxidation and ameliorated liver steatosis and glucose intolerance in diet-induced obese mice, but these beneficial effects were not observed in mice expressing a phosphor-mimic S164D-SIRT1 mutant. Remarkably, phosphorylated S164-SIRT1 and CK2 levels were also highly elevated in liver samples of NAFLD patients and correlated with disease severity. Thus, inhibition of phosphorylation of SIRT1 by CK2 may serve as a new therapeutic approach for treatment of NAFLD and other obesity-related diseases. Copyright © 2017 American Society for Microbiology.

Obesity-Linked Phosphorylation of SIRT1 by Casein Kinase 2 Inhibits Its Nuclear Localization and Promotes Fatty Liver

PubMed Central

Choi, Sung E.; Kwon, Sanghoon; Seok, Sunmi; Xiao, Zhen; Lee, Kwan-Woo; Kang, Yup; Li, Xiaoling; Shinoda, Kosaku; Kajimura, Shingo; Kemper, Byron

2017-01-01

ABSTRACT Sirtuin1 (SIRT1) deacetylase delays and improves many obesity-related diseases, including nonalcoholic fatty liver disease (NAFLD) and diabetes, and has received great attention as a drug target. SIRT1 function is aberrantly low in obesity, so understanding the underlying mechanisms is important for drug development. Here, we show that obesity-linked phosphorylation of SIRT1 inhibits its function and promotes pathological symptoms of NAFLD. In proteomic analysis, Ser-164 was identified as a major serine phosphorylation site in SIRT1 in obese, but not lean, mice, and this phosphorylation was catalyzed by casein kinase 2 (CK2), the levels of which were dramatically elevated in obesity. Mechanistically, phosphorylation of SIRT1 at Ser-164 substantially inhibited its nuclear localization and modestly affected its deacetylase activity. Adenovirus-mediated liver-specific expression of SIRT1 or a phosphor-defective S164A-SIRT1 mutant promoted fatty acid oxidation and ameliorated liver steatosis and glucose intolerance in diet-induced obese mice, but these beneficial effects were not observed in mice expressing a phosphor-mimic S164D-SIRT1 mutant. Remarkably, phosphorylated S164-SIRT1 and CK2 levels were also highly elevated in liver samples of NAFLD patients and correlated with disease severity. Thus, inhibition of phosphorylation of SIRT1 by CK2 may serve as a new therapeutic approach for treatment of NAFLD and other obesity-related diseases. PMID:28533219

Role of Plant-Specific N-Terminal Domain of Maize CK2β1 Subunit in CK2β Functions and Holoenzyme Regulation

PubMed Central

Vélez-Bermúdez, Isabel C.; Carretero-Paulet, Lorenzo; Lumbreras, Victoria; Pagès, Montserrat

2011-01-01

Protein kinase CK2 is a highly pleiotropic Ser/Thr kinase ubiquituous in eukaryotic organisms. CK2 is organized as a heterotetrameric enzyme composed of two types of subunits: the catalytic (CK2α) and the regulatory (CK2β). The CK2β subunits enhance the stability, activity and specificity of the holoenzyme, but they can also perform functions independently of the CK2 tetramer. CK2β regulatory subunits in plants differ from their animal or yeast counterparts, since they present an additional specific N-terminal extension of about 90 aminoacids that shares no homology with any previously characterized functional domain. Sequence analysis of the N-terminal domain of land plant CK2β subunit sequences reveals its arrangement through short, conserved motifs, some of them including CK2 autophosphorylation sites. By using maize CK2β1 and a deleted version (ΔNCK2β1) lacking the N-terminal domain, we have demonstrated that CK2β1 is autophosphorylated within the N-terminal domain. Moreover, the holoenzyme composed with CK2α1/ΔNCK2β1 is able to phosphorylate different substrates more efficiently than CK2α1/CK2β1 or CK2α alone. Transient overexpression of CK2β1 and ΔNCK2β1 fused to GFP in different plant systems show that the presence of N-terminal domain enhances aggregation in nuclear speckles and stabilizes the protein against proteasome degradation. Finally, bimolecular fluorescence complementation (BiFC) assays show the nuclear and cytoplasmic location of the plant CK2 holoenzyme, in contrast to the individual CK2α/β subunits mainly observed in the nucleus. All together, our results support the hypothesis that the plant-specific N-terminal domain of CK2β subunits is involved in the down-regulation of the CK2 holoenzyme activity and in the stabilization of CK2β1 protein. In summary, the whole amount of data shown in this work suggests that this domain was acquired by plants for regulatory purposes. PMID:21789193

Protein S is inducible by interleukin 4 in T cells and inhibits lymphoid cell procoagulant activity

PubMed Central

Smiley, Stephen T.; Boyer, Sarah N.; Heeb, Mary J.; Griffin, John H.; Grusby, Michael J.

1997-01-01

Extravascular procoagulant activity often accompanies cell-mediated immune responses and systemic administration of pharmacologic anticoagulants prevents cell-mediated delayed-type hypersensitivity reactions. These observations suggest a direct association between coagulation and cell-mediated immunity. The cytokine interleukin (IL)-4 potently suppresses cell-mediated immune responses, but its mechanism of action remains to be determined. Herein we demonstrate that the physiologic anticoagulant protein S is IL-4-inducible in primary T cells. Although protein S was known to inhibit the classic factor Va-dependent prothrombinase assembled by endothelial cells and platelets, we found that protein S also inhibits the factor Va-independent prothrombinase assembled by lymphoid cells. Thus, protein S-mediated down-regulation of lymphoid cell procoagulant activity may be one mechanism by which IL-4 antagonizes cell-mediated immunity. PMID:9326636

S100A4 amplifies TGF-β-induced epithelial–mesenchymal transition in a pleural mesothelial cell line

PubMed Central

Ning, Qian; Li, Feiyan; Wang, Lei; Li, Hong; Yao, Yan; Hu, Tinghua; Sun, Zhongmin

2018-01-01

Pleural fibrosis can dramatically lower the quality of life. Numerous studies have reported that epithelial–mesenchymal transition (EMT) regulated by transforming growth factor-β (TGF-β) is involved in fibrosis. However, the molecular mechanism is inadequately understood. Fibroblast-specific protein-1 (S100A4) is a target of TGF-β signaling. In our previous study, we have reported that S100A4 is highly expressed in pleural fibrosis. Thus, we suggest that S100A4 took part in the TGF-β-induced EMT in pleural fibrosis. In this study, we determined the expression of S100A4 and EMT-related markers in Met-5A cells (pleural mesothelial cells) treated with TGF-β or TGF-β inhibitor by real-time PCR and western blot. In order to explore the role of S100A4, we used siRNA to knock down the expression of S100A4 in cell model. We found that the expression of epithelial cell marker was decreased and the mesenchymal cell marker increased with S100A4 upregulation after treatment with TGF-β. Moreover, the changes of EMT-related event were restricted when the expression of S100A4 was knocked down. Conversely, S100A4 can partially rescue the EMT-related expression changes induced by TGF-β inhibitor. These findings suggest that S100A4 expression is induced by the TGF-β pathway, and silencing S100A4 expression can inhibit the process of TGF-β-induced EMT. PMID:29141874

Calcium Activates Nedd4 E3 Ubiquitin Ligases by Releasing the C2 Domain-mediated Auto-inhibition*

PubMed Central

Wang, Jian; Peng, Qisheng; Lin, Qiong; Childress, Chandra; Carey, David; Yang, Wannian

2010-01-01

Nedd4 E3 ligases are members of the HECT E3 ubiquitin ligase family and regulate ubiquitination-mediated protein degradation. In this report, we demonstrate that calcium releases the C2 domain-mediated auto-inhibition in both Nedd4-1 and Nedd4-2. Calcium disrupts binding of the C2 domain to the HECT domain. Consistent with this, calcium activates the E3 ubiquitin ligase activity of Nedd4. Elevation of intracellular calcium by ionomycin treatment, or activation of acetylcholine receptor or epidermal growth factor receptor by carbachol or epidermal growth factor stimulation induced activation of endogenous Nedd4 in vivo evaluated by assays of either Nedd4 E3 ligase activity or ubiquitination of Nedd4 substrate ENaC-β. The activation effect of calcium on Nedd4 E3 ligase activity was dramatically enhanced by a membrane-rich fraction, suggesting that calcium-mediated membrane translocation through the C2 domain might be an activation mechanism of Nedd4 in vivo. Our studies have revealed an activation mechanism of Nedd4 E3 ubiquitin ligases and established a connection of intracellular calcium signaling to regulation of protein ubiquitination. PMID:20172859

Demonstration of subcellular migration of CK2α localization from nucleus to sarco(endo)plasmic reticulum in mammalian cardiomyocytes under hyperglycemia.

PubMed

Bitirim, Ceylan Verda; Tuncay, Erkan; Turan, Belma

2018-06-01

The cellular control of glucose uptake and glycogen metabolism in mammalian tissues is in part mediated through the regulation of protein-serine/threonine kinases including CK2. Although it participates to several cellular signaling processes, however, its subcellular localization is not well-defined while some documents mentioned its localization change under pathological conditions. The activation/phosphorylation of some proteins including Zn 2+ -transporter ZIP7 in cardiomyocytes is controlled with CK2α, thereby, inducing changes in the level of intracellular free Zn 2+ ([Zn 2+ ] i ). In this regard, we aimed to examine cellular localization of CK2α in cardiomyocytes and its possible subcellular migration under hyperglycemia. Our confocal imaging together with biochemical analysis in isolated sarco(endo)plasmic reticulum [S(E)R] and nuclear fractions from hearts have shown that CK2α localized highly to S(E)R and Golgi and weakly to nuclear fractions in physiological condition. However, it can migrate from nuclear fractions to S(E)R under hyperglycemia. This migration can further underlie phosphorylation of a target protein ZIP7 as well as some endogenous kinases and phosphatases including PKA, CaMKII, and PP2A. We also have shown that CK2α activation is responsible for hyperglycemia-associated [Zn 2+ ] i increase in diabetic heart. Therefore, our present data demonstrated, for the first time, the physiological relevance of CK2α in cellular control of Zn 2+ -distribution via inducing ZIP7 phosphorylation and activation of these above endogenous actors in hyperglycemia/diabetes-associated cardiac dysfunction. Moreover, our present data also emphasized the multi-subcellular compartmental localizations of CK2α and a tightly regulation of these localizations in cardiomyocytes. Therefore, taken into consideration of all data, one can emphasize the important role of the subcellular localization of CK2α as a novel target-pathway for understanding of diabetic

Quercetin-4′-O-β-D-glucopyranoside (QODG) Inhibits Angiogenesis by Suppressing VEGFR2-Mediated Signaling in Zebrafish and Endothelial Cells

PubMed Central

Lin, Chen; Wu, Menghua; Dong, Jianyong

2012-01-01

Background Angiogenesis plays an important role in many physiological and pathological processes. Identification of small molecules that block angiogenesis and are safe and affordable has been a challenge in drug development. Hypericum attenuatum Choisy is a Chinese herb medicine commonly used for treating hemorrhagic diseases. The present study investigates the anti-angiogenic effects of quercetin-4′-O-β-D-glucopyranoside (QODG), a flavonoid isolated from Hypericum attenuatum Choisy, in vivo and in vitro, and clarifies the underlying mechanism of the activity. Methodology/Principal Findings Tg(fli1:EGFP) transgenic zebrafish embryos were treated with different concentrations of quercetin-4′-O-β-D-glucopyranoside (QODG) (20, 60, 180 µM) from 6 hours post fertilisation (hpf) to 72 hpf, and adult zebrafish were allowed to recover in different concentrations of QODG (20, 60, 180 µM) for 7 days post amputation (dpa) prior morphological observation and angiogenesis phenotypes assessment. Human umbilical vein endothelial cells (HUVECs) were treated with or without VEGF and different concentrations of QODG (5, 20, 60, 180 µM), then tested for cell viability, cell migration, tube formation and apoptosis. The role of VEGFR2-mediated signaling pathway in QODG-inhibited angiogenesis was evaluated using quantitative real-time PCR (qRT-PCR) and Western blotting. Conclusion/Significance Quercetin-4′-O-β-D-glucopyranoside (QODG) was shown to inhibit angiogenesis in human umbilical vein endothelial cells (HUVECs) in vitro and zebrafish in vivo via suppressing VEGF-induced phosphorylation of VEGFR2. Our results further indicate that QODG inhibits angiogenesis via inhibition of VEGFR2-mediated signaling with the involvement of some key kinases such as c-Src, FAK, ERK, AKT, mTOR and S6K and induction of apoptosis. Together, this study reveals, for the first time, that QODG acts as a potent VEGFR2 kinase inhibitor, and exerts the anti-angiogenic activity at least in part

S100A4 amplifies TGF-β-induced epithelial-mesenchymal transition in a pleural mesothelial cell line.

PubMed

Ning, Qian; Li, Feiyan; Wang, Lei; Li, Hong; Yao, Yan; Hu, Tinghua; Sun, Zhongmin

2018-02-01

Pleural fibrosis can dramatically lower the quality of life. Numerous studies have reported that epithelial-mesenchymal transition (EMT) regulated by transforming growth factor-β (TGF-β) is involved in fibrosis. However, the molecular mechanism is inadequately understood. Fibroblast-specific protein-1 (S100A4) is a target of TGF-β signaling. In our previous study, we have reported that S100A4 is highly expressed in pleural fibrosis. Thus, we suggest that S100A4 took part in the TGF-β-induced EMT in pleural fibrosis. In this study, we determined the expression of S100A4 and EMT-related markers in Met-5A cells (pleural mesothelial cells) treated with TGF-β or TGF-β inhibitor by real-time PCR and western blot. In order to explore the role of S100A4, we used siRNA to knock down the expression of S100A4 in cell model. We found that the expression of epithelial cell marker was decreased and the mesenchymal cell marker increased with S100A4 upregulation after treatment with TGF-β. Moreover, the changes of EMT-related event were restricted when the expression of S100A4 was knocked down. Conversely, S100A4 can partially rescue the EMT-related expression changes induced by TGF-β inhibitor. These findings suggest that S100A4 expression is induced by the TGF-β pathway, and silencing S100A4 expression can inhibit the process of TGF-β-induced EMT. © American Federation for Medical Research (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Proinflammatory Proteins S100A8/S100A9 Activate NK Cells via Interaction with RAGE.

PubMed

Narumi, Kenta; Miyakawa, Reina; Ueda, Ryosuke; Hashimoto, Hisayoshi; Yamamoto, Yuki; Yoshida, Teruhiko; Aoki, Kazunori

2015-06-01

S100A8/A9, a proinflammatory protein, is upregulated in inflammatory diseases, and also has a tumor-promoting activity by the recruitment of myeloid cells and tumor cell invasion. However, whether the expression of S100A8/A9 in tumors predicts a good or poor prognosis is controversial in the clinical setting. In this study, to clarify the in vivo role of S100A8/A9 in the tumor microenvironment, we s.c. inoculated Pan02 cells stably expressing S100A8 and S100A9 proteins (Pan02-S100A8/A9) in syngeneic C57BL/6 mice. Unexpectedly, after small tumor nodules were once established, they rapidly disappeared. Flow cytometry showed that the number of NK cells in the tumors was increased, and an administration of anti-asialoGM1 Ab for NK cell depletion promoted the growth of Pan02-S100A8/A9 s.c. tumors. Although the S100A8/A9 proteins alone did not change the IFN-γ expression of NK cells in vitro, a coculture with Pan02 cells, which express Rae-1, induced IFN-γ production, and Pan02-S100A8/A9 cells further increased the number of IFN-γ(+) NK cells, suggesting that S100A8/A9 enhanced the NK group 2D ligand-mediated intracellular activation pathway in NK cells. We then examined whether NK cell activation by S100A8/A9 was via their binding to receptor of advanced glycation end product (RAGE) by using the inhibitors. RAGE antagonistic peptide and anti-RAGE Ab inhibited the IFN-γ production of NK cells induced by S100A8/A9 proteins, and an administration of FPS-ZM1, a RAGE inhibitor, significantly enhanced the in vivo growth of Pan02-S100A8/A9 tumors. We thus found a novel activation mechanism of NK cells via S100A8/A9-RAGE signaling, which may open a novel perspective on the in vivo interaction between inflammation and innate immunity. Copyright © 2015 by The American Association of Immunologists, Inc.

Downregulation of S100A4 Alleviates Cardiac Fibrosis via Wnt/β -Catenin Pathway in Mice.

PubMed

Qian, LiJun; Hong, Jian; Zhang, YanMei; Zhu, MengLin; Wang, XinChun; Zhang, YanJuan; Chu, Ming; Yao, Jing; Xu, Di

2018-05-07

Cardiac fibrosis is a pathological change leading to cardiac remodeling during the progression of myocardial ischemic diseases, and its therapeutic strategy remains to be explored. S100A4, a calcium-binding protein, participates in fibrotic diseases with an unclear mechanism. This study aimed to investigate the role of S100A4 in cardiac fibrosis. Cardiac fibroblasts from neonatal C57BL/6 mouse hearts were isolated and cultured. Myocardial infarction was induced by ligating the left anterior descending coronary artery (LAD). The ligation was not performed in the sham group. A volume of 5×105pfu/g adenovirus or 5 µM/g ICG-001 was intramyocardially injected into five parts bordering the infarction zone or normal region. We used Western blotting, quantitative RT-PCR, immunofluorescence, immunohistochemistry and Masson's trichrome staining to explore the function of S100A4. We found significant increases of S100A4 level and cardiac fibrosis markers, and β-catenin signaling activation in vitro and in vivo. In addition, knockdown of S100A4 significantly reduced cardiac fibrosis and β-catenin levels. Moreover, the expression of S100A4 decreased after ICG-001 inhibited β-catenin signal pathway. Downregulation of S100A4 alleviates cardiac fibrosis via Wnt/β -catenin pathway in mice. S100A4 may be a therapeutic target of cardiac fibrosis. © 2018 The Author(s). Published by S. Karger AG, Basel.

Phosphodiesterase type 4 inhibition enhances nitric oxide- and hydrogen sulfide-mediated bladder neck inhibitory neurotransmission.

PubMed

Agis-Torres, Ángel; Recio, Paz; López-Oliva, María Elvira; Martínez, María Pilar; Barahona, María Victoria; Benedito, Sara; Bustamante, Salvador; Jiménez-Cidre, Miguel Ángel; García-Sacristán, Albino; Prieto, Dolores; Fernandes, Vítor S; Hernández, Medardo

2018-03-16

Nitric oxide (NO) and hydrogen sulfide (H 2 S) play a pivotal role in nerve-mediated relaxation of the bladder outflow region. In the bladder neck, a marked phosphodiesterase type 4 (PDE4) expression has also been described and PDE4 inhibitors, as rolipram, produce smooth muscle relaxation. This study investigates the role of PDE4 isoenzyme in bladder neck gaseous inhibitory neurotransmission. We used Western blot and double immunohistochemical staining for the detection of NPP4 (PDE4) and PDE4A and organ baths for isometric force recording to roflumilast and tadalafil, PDE4 and PDE5, respectively, inhibitors in pig and human samples. Endogenous H 2 S production measurement and electrical field stimulation (EFS) were also performed. A rich PDE4 and PDE4A expression was observed mainly limited to nerve fibers of the smooth muscle layer of both species. Moreover, roflumilast produced a much more potent smooth muscle relaxation than that induced by tadalafil. In porcine samples, H 2 S generation was diminished by H 2 S and NO synthase inhibition and augmented by roflumilast. Relaxations elicited by EFS were potentiated by roflumilast. These results suggest that PDE4, mainly PDE4A, is mostly located within nerve fibers of the pig and human bladder neck, where roflumilast produces a powerful smooth muscle relaxation. In pig, the fact that roflumilast increases endogenous H 2 S production and EFS-induced relaxations suggests a modulation of PDE4 on NO- and H 2 S-mediated inhibitory neurotransmission.

Coat Protein Regulation by CK2, CPIP, HSP70, and CHIP Is Required for Potato Virus A Replication and Coat Protein Accumulation

PubMed Central

Lõhmus, Andres; Hafrén, Anders

2016-01-01

ABSTRACT We demonstrate here that both coat protein (CP) phosphorylation by protein kinase CK2 and a chaperone system formed by two heat shock proteins, CP-interacting protein (CPIP) and heat shock protein 70 (HSP70), are essential for potato virus A (PVA; genus Potyvirus) replication and that all these host proteins have the capacity to contribute to the level of PVA CP accumulation. An E3 ubiquitin ligase called carboxyl terminus Hsc70-interacting protein (CHIP), which may participate in the CPIP-HSP70-mediated CP degradation, is also needed for robust PVA gene expression. Residue Thr243 within the CK2 consensus sequence of PVA CP was found to be essential for viral replication and to regulate CP protein stability. Substitution of Thr243 either with a phosphorylation-mimicking Asp (CPADA) or with a phosphorylation-deficient Ala (CPAAA) residue in CP expressed from viral RNA limited PVA gene expression to the level of nonreplicating PVA. We found that both the CPAAA mutant and CK2 silencing inhibited, whereas CPADA mutant and overexpression of CK2 increased, PVA translation. From our previous studies, we know that phosphorylation reduces the RNA binding capacity of PVA CP and an excess of CP fully blocks viral RNA translation. Together, these findings suggest that binding by nonphosphorylated PVA CP represses viral RNA translation, involving further CP phosphorylation and CPIP-HSP70 chaperone activities as prerequisites for PVA replication. We propose that this mechanism contributes to shifting potyvirus RNA from translation to replication. IMPORTANCE Host protein kinase CK2, two host chaperones, CPIP and HSP70, and viral coat protein (CP) phosphorylation at Thr243 are needed for potato virus A (PVA) replication. Our results show that nonphosphorylated CP blocks viral translation, likely via binding to viral RNA. We propose that this translational block is needed to allow time and space for the formation of potyviral replication complex around the 3′ end of

Secretion of S100A8, S100A9, and S100A12 by Neutrophils Involves Reactive Oxygen Species and Potassium Efflux.

PubMed

Tardif, Mélanie R; Chapeton-Montes, Julie Andrea; Posvandzic, Alma; Pagé, Nathalie; Gilbert, Caroline; Tessier, Philippe A

2015-01-01

S100A8/A9 (calprotectin) and S100A12 proinflammatory mediators are found at inflammatory sites and in the serum of patients with inflammatory or autoimmune diseases. These cytoplasmic proteins are secreted by neutrophils at sites of inflammation via alternative secretion pathways of which little is known. This study examined the nature of the stimuli leading to S100A8/A9 and S100A12 secretion as well as the mechanism involved in this alternative secretion pathway. Chemotactic agents, cytokines, and particulate molecules were used to stimulate human neutrophils. MSU crystals, PMA, and H2O2 induced the release of S100A8, S100A9, and S100A12 homodimers, as well as S100A8/A9 heterodimer. High concentrations of S100A8/A9 and S100A12 were secreted in response to nanoparticles like MSU, silica, TiO2, fullerene, and single-wall carbon nanotubes as well as in response to microbe-derived molecules, such as zymosan or HKCA. However, neutrophils exposed to the chemotactic factors fMLP failed to secrete S100A8/A9 or S100A12. Secretion of S100A8/A9 was dependent on the production of reactive oxygen species and required K(+) exchanges through the ATP-sensitive K(+) channel. Altogether, these findings suggest that S100A12 and S100A8/A9 are secreted independently either via distinct mechanisms of secretion or following the activation of different signal transduction pathways.

Secretion of S100A8, S100A9, and S100A12 by Neutrophils Involves Reactive Oxygen Species and Potassium Efflux

PubMed Central

Tardif, Mélanie R.; Chapeton-Montes, Julie Andrea; Posvandzic, Alma; Pagé, Nathalie; Gilbert, Caroline; Tessier, Philippe A.

2015-01-01

S100A8/A9 (calprotectin) and S100A12 proinflammatory mediators are found at inflammatory sites and in the serum of patients with inflammatory or autoimmune diseases. These cytoplasmic proteins are secreted by neutrophils at sites of inflammation via alternative secretion pathways of which little is known. This study examined the nature of the stimuli leading to S100A8/A9 and S100A12 secretion as well as the mechanism involved in this alternative secretion pathway. Chemotactic agents, cytokines, and particulate molecules were used to stimulate human neutrophils. MSU crystals, PMA, and H2O2 induced the release of S100A8, S100A9, and S100A12 homodimers, as well as S100A8/A9 heterodimer. High concentrations of S100A8/A9 and S100A12 were secreted in response to nanoparticles like MSU, silica, TiO2, fullerene, and single-wall carbon nanotubes as well as in response to microbe-derived molecules, such as zymosan or HKCA. However, neutrophils exposed to the chemotactic factors fMLP failed to secrete S100A8/A9 or S100A12. Secretion of S100A8/A9 was dependent on the production of reactive oxygen species and required K+ exchanges through the ATP-sensitive K+ channel. Altogether, these findings suggest that S100A12 and S100A8/A9 are secreted independently either via distinct mechanisms of secretion or following the activation of different signal transduction pathways. PMID:27057553

Inhibition of Expression of the S100A8 Gene Encoding the S100 Calcium-Binding Protein A8 Promotes Apoptosis by Suppressing the Phosphorylation of Protein Kinase B (Akt) in Endometrial Carcinoma and HEC-1A Cells.

PubMed

Liu, Chang; Xing, Guangyang; Wu, Cailiang; Zhu, Jun; Wei, Min; Liu, Dajiang; Ge, Yan; Chen, Yao; Lei, Ting; Yang, Yongxiu

2018-03-29

BACKGROUND The aim of this study was to investigate the expression and silencing of the S100A8 gene, which encodes the S100 calcium-binding protein A8 (S100A8), and apoptosis and phosphorylation of protein kinase B (Akt) in tissue samples of endometrial carcinoma and HEC-1A endometrial adenocarcinoma cells in vitro. MATERIAL AND METHODS Immunohistochemistry (IHC) was used to detect expression of the S100A8 protein in 74 tissue samples of endometrial cancer and 22 normal endometrial tissue samples. A stable S100A8 gene knockdown cell line was constructed using lentiviral packing short hairpin RNA (shRNA) transfected into HEC-1A cells. S100A8 mRNA and S100A8 protein levels were detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting. The effects of expression of the S100A8 gene by endometrial cancer cells was investigated by the MTT assay, cell cycle and apoptotic assays, qRT-PCR, and Western blotting. RESULTS IHC showed high levels of expression of S100A8 protein in endometrial carcinoma tissues, and HEC-1A adenocarcinoma cells (in G1 and G2). Increased expression of S100A8 protein was found endometrial cancer tissues compared with normal endometrial tissues (79.7% vs. 4.5%). S100A8 gene knockdown reduced cell proliferation in the HEC-1A cells compared with control cells, induced cell apoptosis, inhibited the phosphorylation of protein kinase B (Akt), and induced the expression of pro-apoptotic genes, including the cytochrome C gene, CYCS, BAD, BAX, FOXO1, FOXO3, CASP9, and CASP3. CONCLUSIONS In endometrial carcinoma cells, down-regulation of the S100A8 gene induced cell apoptosis via inhibition of the phosphorylated or active form of protein kinase B (Akt).

S100A8 is a Novel Therapeutic Target for Anaplastic Thyroid Carcinoma

PubMed Central

Reeb, Ashley N.; Li, Wen; Sewell, Will; Marlow, Laura A.; Tun, Han W.; Smallridge, Robert C.; Copland, John A.; Spradling, Kyle; Chernock, Rebecca

2015-01-01

Context: Anaplastic thyroid carcinoma (ATC) is one of the most deadly human malignancies. It is 99% lethal, and patients have a median survival of only 6 months after diagnosis. Despite these grim statistics, the mechanism underlying the tumorigenic capability of ATC cells is unclear. Objective: S100A8 and S100A9 proteins have emerged as critical mediators in cancer. The aim was to investigate the expression and function of S100A8 and S100A9 in ATC and the mechanisms involved. Design: We determined the expression of S100A8 and S100A9 in human ATC by gene array analysis and immunohistochemistry. Using RNAi-mediated stable gene knockdown in human ATC cell lines and bioluminescent imaging of orthotopic and lung metastasis mouse models of human ATC, we investigated the effects of S100A8 and S100A9 on tumorigenesis and metastasis. Results: We demonstrated that S100A8 and S100A9 were overexpressed in ATC but not in other types of thyroid carcinomas. In vivo analysis in mice using ATC cells that had S100A8 knocked down revealed reduced tumor growth and lung metastasis, as well as significantly prolonged animal survival. Mechanistic investigations showed that S100A8 promotes ATC cell proliferation through an interaction with RAGE, which activates the p38, ERK1/2 and JNK signaling pathways in the tumor cells. Conclusions: These findings establish a novel role for S100A8 in the promoting and enhancing of ATC progression. They further suggest that the inhibition of S100A8 could represent a relevant therapeutic target, with the potential of enabling a more effective treatment path for this deadly disease. PMID:25423568

S100A8 is a novel therapeutic target for anaplastic thyroid carcinoma.

PubMed

Reeb, Ashley N; Li, Wen; Sewell, Will; Marlow, Laura A; Tun, Han W; Smallridge, Robert C; Copland, John A; Spradling, Kyle; Chernock, Rebecca; Lin, Reigh-Yi

2015-02-01

Anaplastic thyroid carcinoma (ATC) is one of the most deadly human malignancies. It is 99% lethal, and patients have a median survival of only 6 months after diagnosis. Despite these grim statistics, the mechanism underlying the tumorigenic capability of ATC cells is unclear. S100A8 and S100A9 proteins have emerged as critical mediators in cancer. The aim was to investigate the expression and function of S100A8 and S100A9 in ATC and the mechanisms involved. We determined the expression of S100A8 and S100A9 in human ATC by gene array analysis and immunohistochemistry. Using RNAi-mediated stable gene knockdown in human ATC cell lines and bioluminescent imaging of orthotopic and lung metastasis mouse models of human ATC, we investigated the effects of S100A8 and S100A9 on tumorigenesis and metastasis. We demonstrated that S100A8 and S100A9 were overexpressed in ATC but not in other types of thyroid carcinomas. In vivo analysis in mice using ATC cells that had S100A8 knocked down revealed reduced tumor growth and lung metastasis, as well as significantly prolonged animal survival. Mechanistic investigations showed that S100A8 promotes ATC cell proliferation through an interaction with RAGE, which activates the p38, ERK1/2 and JNK signaling pathways in the tumor cells. These findings establish a novel role for S100A8 in the promoting and enhancing of ATC progression. They further suggest that the inhibition of S100A8 could represent a relevant therapeutic target, with the potential of enabling a more effective treatment path for this deadly disease.

A fragment-based approach leading to the discovery of a novel binding site and the selective CK2 inhibitor CAM4066.

PubMed

De Fusco, Claudia; Brear, Paul; Iegre, Jessica; Georgiou, Kathy Hadje; Sore, Hannah F; Hyvönen, Marko; Spring, David R

2017-07-01

Recently we reported the discovery of a potent and selective CK2α inhibitor CAM4066. This compound inhibits CK2 activity by exploiting a pocket located outside the ATP binding site (αD pocket). Here we describe in detail the journey that led to the discovery of CAM4066 using the challenging fragment linking strategy. Specifically, we aimed to develop inhibitors by linking a high-affinity fragment anchored in the αD site to a weakly binding warhead fragment occupying the ATP site. Moreover, we describe the remarkable impact that molecular modelling had on the development of this novel chemical tool. The work described herein shows potential for the development of a novel class of CK2 inhibitors. Copyright © 2017. Published by Elsevier Ltd.

Chimeric peptides as modulators of CK2-dependent signaling: Mechanism of action and off-target effects.

PubMed

Zanin, Sofia; Sandre, Michele; Cozza, Giorgio; Ottaviani, Daniele; Marin, Oriano; Pinna, Lorenzo A; Ruzzene, Maria

2015-10-01

Protein kinase CK2 is a tetrameric enzyme composed of two catalytic (α/α') and two regulatory (β) subunits. It has a global prosurvival function, especially in cancer, and represents an attractive therapeutic target. Most CK2 inhibitors available so far are ATP-competitive compounds; however, the possibility to block only the phosphorylation of few substrates has been recently explored, and a compound composed of a Tat cell-penetrating peptide and an active cyclic peptide, selected for its ability to bind to the CK2 substrate E7 protein of human papilloma virus, has been developed [Perea et al., Cancer Res. 2004; 64:7127-7129]. By using a similar chimeric peptide (CK2 modulatory chimeric peptide, CK2-MCP), we performed a study to dissect its molecular mechanism of action and the signaling pathways that it affects in cells. We found that it directly interacts with CK2 itself, counteracting the regulatory and stabilizing functions of the β subunit. Cell treatment with CK2-MCP induces a rapid decrease of the amount of CK2 subunits, as well as of other signaling proteins. Concomitant cell death is observed, more pronounced in tumor cells and not accompanied by apoptotic events. CK2 relocalizes to lysosomes, whose proteases are activated, while the proteasome machinery is inhibited. Several sequence variants of the chimeric peptide have been also synthesized, and their effects compared to those of the parental peptide. Intriguingly, the Tat moiety is essential not only for cell penetration but also for the in vitro efficacy of the peptide. We conclude that this class of chimeric peptides, in addition to altering some properties of CK2 holoenzyme, affects several other cellular targets, causing profound perturbations of cell biology. This article is part of a Special Issue entitled: Inhibitors of Protein Kinases. Copyright © 2015 Elsevier B.V. All rights reserved.

Zinc Replenishment Reverses Overexpression of the Proinflammatory Mediator S100A8 and Esophageal Preneoplasia in the Rat

PubMed Central

Taccioli, Cristian; Wan, Shao-Gui; Liu, Chang-Gong; Alder, Hansjuerg; Volinia, Stefano; Farber, John L.; Croce, Carlo M.

2009-01-01

Background & Aims Zinc-deficiency is implicated in the pathogenesis of human esophageal cancer. In the rat esophagus, it induces cell proliferation, modulates genetic expression, and enhances carcinogenesis. Zinc-replenishment reverses proliferation and inhibits carcinogenesis. The zinc-deficient rat model allows the identification of biological differences affected by zinc during early esophageal carcinogenesis. Methods We evaluated gene expression profiles of esophageal epithelia from zinc-deficient and replenished rats versus sufficient rats using Affymetrix Rat Genome GeneChip. We characterized the role of the top-upregulated gene S100A8 in esophageal hyperplasia/reversal and in chemically-induced esophageal carcinogenesis in zinc-modulated animals by immunohistochemistry and real-time quantitative polymerase chain reaction. Results The hyperplastic deficient esophagus has a distinct expression signature with the proinflammation-gene S100A8 and S100A9 upregulated 57- and 5-fold. “Response to external stimulus” comprising S100A8 was the only significantly overrepresented biological pathway among the upregulated genes. Zinc-replenishment rapidly restored to control levels the expression of S100A8/A9 and 27 other genes and reversed the hyperplastic phenotype. With its receptor RAGE, co-localization and overexpression of S100A8 protein occurred in the deficient esophagus that overexpressed NF-κB p65 and COX-2 protein. Zinc-replenishment but not by a COX-2 inhibitor reduced the overexpression of these 4 proteins. Additionally, esophageal S100A8/A9 mRNA levels were directly associated with the diverse tumorigenic outcome in zinc-deficient and zinc-replenished rats. Conclusions In vivo zinc regulates S100A8 expression and modulates the link between S100A8-RAGE interaction and downstream NF-κB/COX-2 signaling. The finding that zinc regulates an inflammatory pathway in esophageal carcinogenesis may lead to prevention and therapy for this cancer. PMID:19111725

Exogenous S100A8 protein inhibits PDGF-induced migration of airway smooth muscle cells in a RAGE-dependent manner.

PubMed

Xu, Yu-Dong; Wei, Ying; Wang, Yu; Yin, Lei-Miao; Park, Gyoung-Hee; Liu, Yan-Yan; Yang, Yong-Qing

2016-03-25

S100A8 is an important member of the S100 protein family, which is involved in intracellular and extracellular regulatory activities. We previously reported that the S100A8 protein was differentially expressed in the asthmatic respiratory tracts. To understand the potential role of S100A8 in asthma, we investigated the effect of recombinant S100A8 protein on the platelet-derived growth factor (PDGF)-induced migration of airway smooth muscle cells (ASMCs) and the underlying molecular mechanism by using multiple methods, such as impedance-based xCELLigence migration assay, transwell migration assays and wound-healing assays. We found that exogenous S100A8 protein significantly inhibited PDGF-induced ASMC migration. Furthermore, the migration inhibition effect of S100A8 was blocked by neutralizing antibody against the receptor for advanced glycation end-products (RAGE), a potential receptor for the S100A8 protein. These findings provide direct evidence that exogenous S100A8 protein inhibits the PDGF-induced migration of ASMCs through the membrane receptor RAGE. Our study highlights a novel role of S100A8 as a potential means of counteracting airway remodeling in chronic airway diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

IL-1β promotes the nuclear translocaiton of S100A4 protein in gastric cancer cells MGC803 and the cell's stem-like properties through PI3K pathway.

PubMed

Yu, Aiwen; Wang, Yu; Bian, Yue; Chen, Lisha; Guo, Junfu; Shen, Wei; Chen, Danqi; Liu, Shanshan; Sun, Xiuju

2018-06-22

It has been shown that nuclear expression of S100A4 is significantly correlated with increased metastasis and reduced survival in patients with gastric cancer and many other cancers. However, the factors which could influence the nuclear contents of S100A4 in cancer cells are not clear. It has also been reported that Interleukin-1β (IL-1β) promotes the nuclear translocation of S100A4 in chondrocytes. Previous studies have shown that IL-1β promotes the stemness of colon cancer cells, and S100A4 is also involved in maintaining cancer-initiating cells in head and neck cancers. We speculate that IL-1β might promote the nuclear translocation of S100A4 protein in MGC803 gastric cancer cells and therefore enhance their stem-like properties. The results from Western-blot and qRT-PCR analysis showed that IL-1β increased the nuclear and total cellular content of S100A4 protein and S100A4 mRNA level in MGC803 cells. LY294002, a pharmacological inhibitor of Phosphoinositide 3-kinase (PI3K) reversed the above effects. Functional studies indicated that IL-1β promoted the colony-forming and spheroid-forming capabilities of the cells and the expression of SOX2 and NANOG gene. PI3K or S100A4 inhibition reversed the IL-1β-mediated increase in colony and spheroid-forming capabilities of the cells. LY294002 also reversed the elevated SOX2 and NANOG expression induced by IL-1β. Our study demonstrated that IL-1β promote the nuclear translocation of S100A4 protein in gastric cancer cells MGC803, which are PI3K dependent, suggesting the existence of IL-1β-PI3K-S100A4 pathway for the first time. The study also showed that IL-1β promoted stem-like properties of the cells through the new pathway. © 2018 Wiley Periodicals, Inc.

Resveratrol inhibits estrogen-induced breast carcinogenesis through induction of NRF2-mediated protective pathways

PubMed Central

Singh, Bhupendra; Shoulson, Rivka; Chatterjee, Anwesha; Ronghe, Amruta; Bhat, Nimee K.; Dim, Daniel C.; Bhat, Hari K.

2014-01-01

The importance of estrogens in the etiology of breast cancer is widely recognized. Estrogen-induced oxidative stress has been implicated in this carcinogenic process. Resveratrol (Res), a natural antioxidant phytoestrogen has chemopreventive effects against a variety of illnesses including cancer. The objective of the present study was to characterize the mechanism(s) of Res-mediated protection against estrogen-induced breast carcinogenesis. Female August Copenhagen Irish rats were treated with 17β-estradiol (E2), Res and Res + E2 for 8 months. Cotreatment of rats with Res and E2 inhibited E2-mediated proliferative changes in mammary tissues and significantly increased tumor latency and reduced E2-induced breast tumor development. Resveratrol treatment alone or in combination with E2 significantly upregulated expression of nuclear factor erythroid 2-related factor 2 (NRF2) in mammary tissues. Expression of NRF2-regulated antioxidant genes NQO1, SOD3 and OGG1 that are involved in protection against oxidative DNA damage was increased in Res- and Res + E2-treated mammary tissues. Resveratrol also prevented E2-mediated inhibition of detoxification genes AOX1 and FMO1. Inhibition of E2-mediated alterations in NRF2 promoter methylation and expression of NRF2 targeting miR-93 after Res treatment indicated Res-mediated epigenetic regulation of NRF2 during E2-induced breast carcinogenesis. Resveratrol treatment also induced apoptosis and inhibited E2-mediated increase in DNA damage in mammary tissues. Increased apoptosis and decreased DNA damage, cell migration, colony and mammosphere formation in Res- and Res + E2-treated MCF-10A cells suggested a protective role of Res against E2-induced mammary carcinogenesis. Small-interfering RNA-mediated silencing of NRF2 inhibited Res-mediated preventive effects on the colony and mammosphere formation. Taken together, these results suggest that Res inhibits E2-induced breast carcinogenesis via induction of NRF2-mediated protective

A Weathering Index for CK and R Chondrites

NASA Technical Reports Server (NTRS)

Rubin, Alan E.; Huber, Heinz

2006-01-01

We present a new weathering index (wi) for the metallic-Fe-Ni-poor chondrite groups (CK and R) based mainly on transmitted light observations of the modal abundance of crystalline material that is stained brown in thin sections: wi-0, <5 vol%; wi-1, 5-25 vol%; wi-2,25-50 vol%; wi-3,50- 75 vol%; wi-4, 75-95 vol%; wi-5, >95 vol%, wi-6, significant replacement of mafic silicates by phyllosilicates. Brown staining reflects mobilization of oxidized iron derived mainly from terrestrial weathering of Ni-bearing sulfide. With increasing degrees of terrestrial weathering of CK and R chondrites, the sulfide modal abundance decreases, and S, Se, and Ni become increasingly depleted. In addition, bulk Cl increases in Antarctic CK chondrites, probably due to contamination from airborne sea mist.

Inhibition of Expression of the S100A8 Gene Encoding the S100 Calcium-Binding Protein A8 Promotes Apoptosis by Suppressing the Phosphorylation of Protein Kinase B (Akt) in Endometrial Carcinoma and HEC-1A Cells

PubMed Central

Liu, Chang; Xing, Guangyang; Wu, Cailiang; Zhu, Jun; Wei, Min; Liu, Dajiang; Ge, Yan; Chen, Yao; Lei, Ting

2018-01-01

Background The aim of this study was to investigate the expression and silencing of the S100A8 gene, which encodes the S100 calcium-binding protein A8 (S100A8), and apoptosis and phosphorylation of protein kinase B (Akt) in tissue samples of endometrial carcinoma and HEC-1A endometrial adenocarcinoma cells in vitro. Material/Methods Immunohistochemistry (IHC) was used to detect expression of the S100A8 protein in 74 tissue samples of endometrial cancer and 22 normal endometrial tissue samples. A stable S100A8 gene knockdown cell line was constructed using lentiviral packing short hairpin RNA (shRNA) transfected into HEC-1A cells. S100A8 mRNA and S100A8 protein levels were detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting. The effects of expression of the S100A8 gene by endometrial cancer cells was investigated by the MTT assay, cell cycle and apoptotic assays, qRT-PCR, and Western blotting. Results IHC showed high levels of expression of S100A8 protein in endometrial carcinoma tissues, and HEC-1A adenocarcinoma cells (in G1 and G2). Increased expression of S100A8 protein was found endometrial cancer tissues compared with normal endometrial tissues (79.7% vs. 4.5%). S100A8 gene knockdown reduced cell proliferation in the HEC-1A cells compared with control cells, induced cell apoptosis, inhibited the phosphorylation of protein kinase B (Akt), and induced the expression of pro-apoptotic genes, including the cytochrome C gene, CYCS, BAD, BAX, FOXO1, FOXO3, CASP9, and CASP3. Conclusions In endometrial carcinoma cells, down-regulation of the S100A8 gene induced cell apoptosis via inhibition of the phosphorylated or active form of protein kinase B (Akt). PMID:29595187

The Protein Kinase CK2 Mediates Cross-Talk between Auxin- and Salicylic Acid-Signaling Pathways in the Regulation of PINOID Transcription

PubMed Central

Armengot, Laia; Caldarella, Eleonora; Marquès-Bueno, Maria Mar; Martínez, M. Carmen

2016-01-01

The protein kinase CK2 is a ubiquitous and highly conserved enzyme, the activity of which is vital for eukaryotic cells. We recently demonstrated that CK2 modulates salicylic acid (SA) homeostasis in Arabidopsis thaliana, and that functional interplay between CK2 and SA sustains transcriptional expression of PIN-FORMED (PIN) genes. In this work, we show that CK2 also plays a key role in the transcriptional regulation of PINOID (PID), an AGC protein kinase that modulates the apical/basal localization of auxin-efflux transporters. We show that PID transcription is up-regulated by auxin and by SA and that CK2 is involved in both pathways. On the one hand, CK2 activity is required for proteosome-dependent degradation of AXR3, a member of the AUX/IAA family of auxin transcriptional repressors that must be degraded to activate auxin-responsive gene expression. On the other hand, the role of CK2 in SA homeostasis and, indirectly, in SA-driven PID transcription, was confirmed by using Arabidopsis NahG transgenic plants, which cannot accumulate SA. In conclusion, our results evidence a role for CK2 as a functional link in the negative cross-talk between auxin- and SA-signaling. PMID:27275924

Emodin, a natural inhibitor of protein kinase CK2, suppresses growth, hyphal development, and biofilm formation of Candida albicans.

PubMed

Janeczko, Monika; Masłyk, Maciej; Kubiński, Konrad; Golczyk, Hieronim

2017-06-01

Emodin (1,3,8-trihydroxy-6-methyl-anthraquinone) is a natural secondary plant product, originally isolated from the rhizomes of Rheum palmatum. Many reports show its diuretic, vasorelaxant, antibacterial, antiviral, anti-ulcerogenic, immunosuppressive, hepatoprotective, anti-inflammatory and anticancer potential. Emodin is a pleiotropic molecule capable of interacting with several major molecular targets, e.g. NF-κB, AKT/mTOR and STAT3. The compound can also act as an inhibitor of some protein kinases, with special affinity to protein kinase CK2. The aim of the presented report was to evaluate antifungal properties of emodin and its activity towards CK2 isolated from Candida cells. Our studies revealed that the compound suppressed growth of the cells of reference strains as well as clinical Candida strains, with minimal inhibitory concentration and minimal fungicidal concentration values between 12.5 and 200 μg/mL. Moreover, at a low concentration, the compound was able to effectively stop hyphal formation, thus showing a distinct antivirulent potential. Interestingly, we showed that emodin added to Candida culture inhibited the phosphorylation of many cellular proteins, presumably owing to the inhibition of protein kinase CK2. Notably, the enzyme isolated from the Candida cells was susceptible to emodin with IC 50 of 2.8 μg/mL. Indeed, our computational modelling revealed that emodin was able to occupy the ATP-binding pocket of CK2. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Hepatocellular carcinoma-associated mesenchymal stem cells promote hepatocarcinoma progression: role of the S100A4-miR155-SOCS1-MMP9 axis.

PubMed

Yan, Xin-Long; Jia, Ya-Li; Chen, Lin; Zeng, Quan; Zhou, Jun-Nian; Fu, Chun-Jiang; Chen, Hai-Xu; Yuan, Hong-Feng; Li, Zhi-Wei; Shi, Lei; Xu, Ying-Chen; Wang, Jing-Xue; Zhang, Xiao-Mei; He, Li-Juan; Zhai, Chao; Yue, Wen; Pei, Xue-Tao

2013-06-01

Cancer-associated mesenchymal stem cells (MSCs) play a pivotal role in modulating tumor progression. However, the interactions between liver cancer-associated MSCs (LC-MSCs) and hepatocellular carcinoma (HCC) remain unreported. Here, we identified the presence of MSCs in HCC tissues. We also showed that LC-MSCs significantly enhanced tumor growth in vivo and promoted tumor sphere formation in vitro. LC-MSCs also promoted HCC metastasis in an orthotopic liver transplantation model. Complementary DNA (cDNA) microarray analysis showed that S100A4 expression was significantly higher in LC-MSCs compared with liver normal MSCs (LN-MSCs) from adjacent cancer-free tissues. Importantly, the inhibition of S100A4 led to a reduction of proliferation and invasion of HCC cells, while exogenous S100A4 expression in HCC cells resulted in heavier tumors and more metastasis sites. Our results indicate that S100A4 secreted from LC-MSCs can promote HCC cell proliferation and invasion. We then found the expression of oncogenic microRNA (miR)-155 in HCC cells was significantly up-regulated by coculture with LC-MSCs and by S100A4 ectopic overexpression. The invasion-promoting effects of S100A4 were significantly attenuated by a miR-155 inhibitor. These results suggest that S100A4 exerts its effects through the regulation of miR-155 expression in HCC cells. We demonstrate that S100A4 secreted from LC-MSCs promotes the expression of miR-155, which mediates the down-regulation of suppressor of cytokine signaling 1, leading to the subsequent activation of STAT3 signaling. This promotes the expression of matrix metalloproteinases 9, which results in increased tumor invasiveness. S100A4 secreted from LC-MSCs is involved in the modulation of HCC progression, and may be a potential therapeutic target. (HEPATOLOGY 2013). Copyright © 2013 American Association for the Study of Liver Diseases.

Somatostatin sst2 receptor-mediated inhibition of parietal cell function in rat isolated gastric mucosa.

PubMed Central

Wyatt, M. A.; Jarvie, E.; Feniuk, W.; Humphrey, P. P.

1996-01-01

1. The aim of this study was to determine the location and functional characteristics of the somatostatin (SRIF) receptor type(s) which mediate inhibition of acid secretion in rat isolated gastric mucosa. 2. Gastrin (1 nM-1 microM), dimaprit (10 microM-300 microM) and isobutyl methylxanthine (IBMX, 1 microM-100 microM) all caused concentration-dependent increases in acid output. Responses to gastrin were almost completely inhibited by ranitidine (10 microM) at a concentration which abolished the secretory response to dimaprit. In contrast, responses to IBMX were not changed by ranitidine suggesting that IBMX acts directly on the parietal cell and not indirectly by releasing histamine from enterochromaffin-like (ECL) cells. 3. SRIF-14 (1 nM-1 microM) had no effect on basal acid output, but inhibited acid output produced by gastrin, dimaprit and IBMX in a concentration-dependent manner with respective EC50 values of 46, 54 and 167 nM. The peptidase inhibitors, amastatin (10 microM) and phosphoramidon (1 microM), had no effect on SRIF-induced inhibition of dimaprit stimulated gastric acid secretion. 4. The inhibitory effect of a range of SRIF analogues on gastrin-, dimaprit- and IBMX-induced acid secretion was also studied. Irrespective of the secretagogue used to increase acid output, the rank order of potencies was similar (BIM-23027 = seglitide = octreotide > SRIF-14 = SRIF-28 > L-362,855). The linear peptide BIM-23056 was devoid of agonist or antagonist activity in concentrations up to 1 microM. 5. The sst2 receptor selective peptides, BIM-23027, seglitide and octreotide were the most potent inhibitors of gastrin-, dimaprit- and IBMX-induced acid secretion suggesting that SRIF receptors resembling the recombinant sst2 receptors are involved. Furthermore, since dimaprit and IBMX stimulate gastric acid secretion independently of histamine release, sst2 receptor-mediated inhibition must occur at the level of the parietal cell itself. PMID:8922739

Somatostatin sst2 receptor-mediated inhibition of parietal cell function in rat isolated gastric mucosa.

PubMed

Wyatt, M A; Jarvie, E; Feniuk, W; Humphrey, P P

1996-11-01

1. The aim of this study was to determine the location and functional characteristics of the somatostatin (SRIF) receptor type(s) which mediate inhibition of acid secretion in rat isolated gastric mucosa. 2. Gastrin (1 nM-1 microM), dimaprit (10 microM-300 microM) and isobutyl methylxanthine (IBMX, 1 microM-100 microM) all caused concentration-dependent increases in acid output. Responses to gastrin were almost completely inhibited by ranitidine (10 microM) at a concentration which abolished the secretory response to dimaprit. In contrast, responses to IBMX were not changed by ranitidine suggesting that IBMX acts directly on the parietal cell and not indirectly by releasing histamine from enterochromaffin-like (ECL) cells. 3. SRIF-14 (1 nM-1 microM) had no effect on basal acid output, but inhibited acid output produced by gastrin, dimaprit and IBMX in a concentration-dependent manner with respective EC50 values of 46, 54 and 167 nM. The peptidase inhibitors, amastatin (10 microM) and phosphoramidon (1 microM), had no effect on SRIF-induced inhibition of dimaprit stimulated gastric acid secretion. 4. The inhibitory effect of a range of SRIF analogues on gastrin-, dimaprit- and IBMX-induced acid secretion was also studied. Irrespective of the secretagogue used to increase acid output, the rank order of potencies was similar (BIM-23027 = seglitide = octreotide > SRIF-14 = SRIF-28 > L-362,855). The linear peptide BIM-23056 was devoid of agonist or antagonist activity in concentrations up to 1 microM. 5. The sst2 receptor selective peptides, BIM-23027, seglitide and octreotide were the most potent inhibitors of gastrin-, dimaprit- and IBMX-induced acid secretion suggesting that SRIF receptors resembling the recombinant sst2 receptors are involved. Furthermore, since dimaprit and IBMX stimulate gastric acid secretion independently of histamine release, sst2 receptor-mediated inhibition must occur at the level of the parietal cell itself.

Metabotropic glutamate receptors coupled to IP3 production mediate inhibition of IAHP in rat dentate granule neurons.

PubMed

Abdul-Ghani, M A; Valiante, T A; Carlen, P L; Pennefather, P S

1996-10-01

1. Whole cell recordings from dentate granule neurons in the hippocampal slice preparation reveal that (1 S, 3R)-1-aminocyclopentane-1,3-dicarboxylic acid (ACPD), a selective agonist at metabotropic glutamate receptors (mGluRs), inhibits a calcium-activated potassium current (IAHP) responsible for the postspike after-hyperpolarization. Inclusion of 1 mM of the Ca2+ chelator ethylene glycol-bis (beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid in the patch pipette reduced the inhibitory action of ACPD on IAHP while having no effect on a similar action of serotonin (5-HT). Thus the known action of ACPD of mobilizing intracellular Ca2+ may be involved in this inhibitor action of ACPD. 2. Inhibition of IAHP is not secondary to effects on Ca2+ currents, because 10 microM ACPD, which inhibits IAHP by 95 +/- 5% (mean +/- SE), reduced the Ca2+ current by only 8 +/- 4%. 3. Activation of mGluRs accelerates the irreversible inhibition of IAHP that develops when 88 microM GTP-gamma-S is included in the pipette filling solution, whereas inclusion of 1 mM GDP-beta-S attenuated the inhibitory action of ACPD. These results indicate that the response to mGluR activation is G protein mediated. 4. Group I mGluRs, which includes mGluR1 and mGluR5, are G-protein-coupled receptors that are known to stimulate phospholipase C (PLC)-mediated hydrolysis of phosphoinositides to produce 1,4,5-triphosphate (IP3), which in turn is known to mobilize the release of intracellular Ca2+. The weak but selective mGluR1 agonist (S)-3-hydroxyphenylglycine (100 microM) completely inhibited IAHP, and the mGluR1 antagonist (S)-4-carboxyphenylglycine (500 microM) reduced IAHP inhibition produced by 5 microM ACPD from 73 +/- 6% to 22 +/- 4%. These results indicate that the mGluR responsible for IAHP inhibition has a similar pharmacological profile to that of those coupled to IP3 production. 5. The effects of agents known to interfere with IP3 production and action also support IP3 involvement in ACPD action

Mammalian FMRP S499 Is Phosphorylated by CK2 and Promotes Secondary Phosphorylation of FMRP.

PubMed

Bartley, Christopher M; O'Keefe, Rachel A; Blice-Baum, Anna; Mihailescu, Mihaela-Rita; Gong, Xuan; Miyares, Laura; Karaca, Esra; Bordey, Angélique

2016-01-01

The fragile X mental retardation protein (FMRP) is an mRNA-binding regulator of protein translation that associates with 4-6% of brain transcripts and is central to neurodevelopment. Autism risk genes' transcripts are overrepresented among FMRP-binding mRNAs, and FMRP loss-of-function mutations are responsible for fragile X syndrome, the most common cause of monogenetic autism. It is thought that FMRP-dependent translational repression is governed by the phosphorylation of serine residue 499 (S499). However, recent evidence suggests that S499 phosphorylation is not modulated by metabotropic glutamate receptor class I (mGluR-I) or protein phosphatase 2A (PP2A), two molecules shown to regulate FMRP translational repression. Moreover, the mammalian FMRP S499 kinase remains unknown. We found that casein kinase II (CK2) phosphorylates murine FMRP S499. Further, we show that phosphorylation of FMRP S499 permits phosphorylation of additional, nearby residues. Evidence suggests that these nearby residues are modulated by mGluR-I and PP2A pathways. These data support an alternative phosphodynamic model of FMRP that is harmonious with prior studies and serves as a framework for further investigation.

CK1/Doubletime activity delays transcription activation in the circadian clock

PubMed Central

O'Neil, Jenna L; Merz, Gregory E; Dusad, Kritika; Crane, Brian R; Young, Michael W

2018-01-01

In the Drosophila circadian clock, Period (PER) and Timeless (TIM) proteins inhibit Clock-mediated transcription of per and tim genes until PER is degraded by Doubletime/CK1 (DBT)-mediated phosphorylation, establishing a negative feedback loop. Multiple regulatory delays within this feedback loop ensure ~24 hr periodicity. Of these delays, the mechanisms that regulate delayed PER degradation (and Clock reactivation) remain unclear. Here we show that phosphorylation of certain DBT target sites within a central region of PER affect PER inhibition of Clock and the stability of the PER/TIM complex. Our results indicate that phosphorylation of PER residue S589 stabilizes and activates PER inhibitory function in the presence of TIM, but promotes PER degradation in its absence. The role of DBT in regulating PER activity, stabilization and degradation ensures that these events are chronologically and biochemically linked, and contributes to the timing of an essential delay that influences the period of the circadian clock. PMID:29611807

S100A8/A9 is an important host defence mediator in neuropathic foot ulcers in patients with type 2 diabetes mellitus.

PubMed

Trøstrup, Hannah; Holstein, Per; Christophersen, Lars; Jørgensen, Bo; Karlsmark, Tonny; Høiby, Niels; Moser, Claus; Ågren, Magnus S

2016-07-01

Chronic wounds and in particular diabetic foot ulcers (DFUs) are a growing clinical challenge, but the underlying molecular pathophysiological mechanisms are unclear. Recently, we reported reduced levels of the immunomodulating and antimicrobial S100A8/A9 in non-healing venous leg ulcers (VLUs), while another study found increased S100A8/A9 in DFUs. To clarify these apparently contradictory findings, we compared S100A8/A9 as well as an inducer, lipopolysaccharide (LPS) and selected innate immune response mediators in wound fluids from non-healing DFUs and VLUs with healing wounds. Wound fluids were collected from neuropathic DFUs (n = 6) and VLUs (n = 9) of median 2-year duration, and split-thickness skin graft donor site wounds (n = 10) by standardized method. None of the patients had ischaemic extremities or clinically infected wounds. LPS was determined by limulus amoebocyte lysate test, and S100A8/A9, granulocyte colony-stimulating factor (G-CSF), interleukin (IL)-10 and vascular endothelial growth factor (VEGF) by immunospecific quantitative assays. LPS levels were median 8.7 (interquartile range 5.4-21.2) ng/ml in DFUs compared with 121 (22-2000) ng/ml in VLUs. S100A8/A9 was higher (p = 0.020) in DFUs [718 (634-811) µg/ml] than in VLUs [303 (252-533) µg/ml]. Neither G-CSF nor IL-10 wound fluid levels differed significantly between the chronic wound groups. VEGF levels correlated with LPS (r = 0.758, p = 0.011, n = 10) and were higher (p = 0.024) in VLU wound fluids. LPS (p < 0.0001), S100A8/A9 (p = 0.005), G-CSF (p = 0.003), IL-10 (p = 0.003) and VEGF (p = 0.005) were increased in chronic wound fluids combined compared with the sterile donor site wound fluids. The protein alterations in the wounds were not reflected in the patients' sera. Low S100A8/A9 levels may contribute to poor wound healing in colonized chronic wounds with striking difference between DFUs and VLUs.

SMAD4 loss enables EGF, TGFβ1 and S100A8/A9 induced activation of critical pathways to invasion in human pancreatic adenocarcinoma cells.

PubMed

Moz, Stefania; Basso, Daniela; Bozzato, Dania; Galozzi, Paola; Navaglia, Filippo; Negm, Ola H; Arrigoni, Giorgio; Zambon, Carlo-Federico; Padoan, Andrea; Tighe, Paddy; Todd, Ian; Franchin, Cinzia; Pedrazzoli, Sergio; Punzi, Leonardo; Plebani, Mario

2016-10-25

Epidermal Growth Factor (EGF) receptor overexpression, KRAS, TP53, CDKN2A and SMAD4 mutations characterize pancreatic ductal adenocarcinoma. This mutational landscape might influence cancer cells response to EGF, Transforming Growth Factor β1 (TGFβ1) and stromal inflammatory calcium binding proteins S100A8/A9. We investigated whether chronic exposure to EGF modifies in a SMAD4-dependent manner pancreatic cancer cell signalling, proliferation and invasion in response to EGF, TGFβ1 and S100A8/A9. BxPC3, homozigously deleted (HD) for SMAD4, and BxPC3-SMAD4+ cells were or not stimulated with EGF (100 ng/mL) for three days. EGF pre-treated and non pretreated cells were stimulated with a single dose of EGF (100 ng/mL), TGFβ1 (0,02 ng/mL), S100A8/A9 (10 nM). Signalling pathways (Reverse Phase Protein Array and western blot), cell migration (Matrigel) and cell proliferation (XTT) were evaluated. SMAD4 HD constitutively activated ERK and Wnt/β-catenin, while inhibiting PI3K/AKT pathways. These effects were antagonized by chronic EGF, which increased p-BAD (anti-apoptotic) in response to combined TGFβ1 and S100A8/A9 stimulation. SMAD4 HD underlied the inhibition of NF-κB and PI3K/AKT in response to TGFβ1 and S100A8/A9, which also induced cell migration. Chronic EGF exposure enhanced cell migration of both BxPC3 and BxPC3-SMAD4+, rendering the cells less sensitive to the other inflammatory stimuli. In conclusion, SMAD4 HD is associated with the constitutive activation of the ERK and Wnt/β-catenin signalling pathways, and favors the EGF-induced activation of multiple signalling pathways critical to cancer proliferation and invasion. TGFβ1 and S100A8/A9 mainly inhibit NF-κB and PI3K/AKT pathways and, when combined, sinergize with EGF in enhancing anti-apoptotic p-BAD in a SMAD4-dependent manner.

Selective inhibition of prostaglandin E2 receptors EP2 and EP4 inhibits adhesion of human endometriotic epithelial and stromal cells through suppression of integrin-mediated mechanisms.

PubMed

Lee, JeHoon; Banu, Sakhila K; Burghardt, Robert C; Starzinski-Powitz, Anna; Arosh, Joe A

2013-03-01

Endometriosis is a chronic gynecological disease of reproductive age women characterized by the presence of functional endometrial tissues outside the uterine cavity. Interactions between the endometriotic cells and the peritoneal extracellular matrix proteins (ECM) are crucial mechanisms that allow adhesion of the endometriotic cells into peritoneal mesothelia. Prostaglandin E2 (PGE2) plays an important role in the pathogenesis of endometriosis. In previous studies, we have reported that selective inhibition of PGE2 receptors PTGER2 and PTGER4 decreases survival and invasion of human endometriotic epithelial and stromal cells through multiple mechanisms. Results of the present study indicates that selective inhibition of PTGER2- and PTGER4-mediated PGE2 signaling 1) decreases the expression and/or activity of specific integrin receptor subunits Itgb1 (beta1) and Itgb3 (beta3) but not Itgb5 (beta5), Itga1 (alpha1), Itga2 (alpha2), Itga5 (alpha5), and Itgav (alphav); 2) decreases integrin-signaling components focal adhesion kinase or protein kinase 2 (PTK2) and talin proteins; 3) inhibits interactions between Itgb1/Itgb3 subunits, PTK2, and talin and PTGER2/PTGER4 proteins through beta-arrestin-1 and Src kinase protein complex in human endometriotic epithelial cells 12Z and stromal cells 22B; and 4) decreases adhesion of 12Z and 22B cells to ECM collagen I, collagen IV, fibronectin, and vitronectin in a substrate-specific manner. These novel findings provide an important molecular framework for further evaluation of selective inhibition of PTGER2 and PTGER4 as potential nonsteroidal therapy to expand the spectrum of currently available treatment options for endometriosis in child-bearing age women.

A Biosensor of S100A4 Metastasis Factor Activation: Inhibitor Screening and Cellular Activation Dynamics†

PubMed Central

Garrett, Sarah C.; Hodgson, Louis; Rybin, Andrew; Toutchkine, Alexei; Hahn, Klaus M.; Lawrence, David S.; Bresnick, Anne R.

2011-01-01

S100A4, a member of the S100 family of Ca2+-binding proteins, displays elevated expression in malignant human tumors compared with benign tumors, and increased expression correlates strongly with poor patient survival. S100A4 has a direct role in metastatic progression, likely due to the modulation of actomyosin cytoskeletal dynamics, which results in increased cellular motility. We developed a fluorescent biosensor (Mero-S100A4) that reports on the Ca2+-bound, activated form of S100A4. Direct attachment of a novel solvatochromatic reporter dye to S100A4 results in a sensor that, upon activation, undergoes a 3-fold enhancement in fluorescence, thus providing a sensitive assay for use in vitro and in vivo. In cells, localized activation of S100A4 at the cell periphery is observed during random migration and following stimulation with lysophosphatidic acid, a known activator of cell motility and proliferation. Additionally, a screen against a library of FDA-approved drugs with the biosensor identified an array of phenothiazines as inhibitors of myosin-II associated S100A4 function. These data demonstrate the utility of the new biosensor both for drug discovery and for probing the cellular dynamics controlled by the S100A4 metastasis factor. PMID:18154362

Caffeine Inhibits the Activation of Hepatic Stellate Cells Induced by Acetaldehyde via Adenosine A2A Receptor Mediated by the cAMP/PKA/SRC/ERK1/2/P38 MAPK Signal Pathway

PubMed Central

Yang, Wanzhi; Wang, Qi; Zhao, Han; Yang, Feng; Lv, Xiongwen; Li, Jun

2014-01-01

Hepatic stellate cell (HSC) activation is an essential event during alcoholic liver fibrosis. Evidence suggests that adenosine aggravates liver fibrosis via the adenosine A2A receptor (A2AR). Caffeine, which is being widely consumed during daily life, inhibits the action of adenosine. In this study, we attempted to validate the hypothesis that caffeine influences acetaldehyde-induced HSC activation by acting on A2AR. Acetaldehyde at 50, 100, 200, and 400 μM significantly increased HSC-T6 cells proliferation, and cell proliferation reached a maximum at 48 h after exposure to 200 μM acetaldehyde. Caffeine and the A2AR antagonist ZM241385 decreased the cell viability and inhibited the expression of procollagen type I and type III in acetaldehyde-induced HSC-T6 cells. In addition, the inhibitory effect of caffeine on the expression of procollagen type I was regulated by A2AR-mediated signal pathway involving cAMP, PKA, SRC, and ERK1/2. Interestingly, caffeine’s inhibitory effect on the expression of procollagen type III may depend upon the A2AR-mediated P38 MAPK-dependent pathway. Conclusions: Caffeine significantly inhibited acetaldehyde-induced HSC-T6 cells activation by distinct A2AR mediated signal pathway via inhibition of cAMP-PKA-SRC-ERK1/2 for procollagen type I and via P38 MAPK for procollagen type III. PMID:24682220

Apigenin: Selective CK2 inhibitor increases Ikaros expression and improves T cell homeostasis and function in murine pancreatic cancer

PubMed Central

Nelson, Nadine; Szekeres, Karoly; Iclozan, Cristina; Rivera, Ivannie Ortiz; McGill, Andrew; Johnson, Gbemisola; Nwogu, Onyekachi

2017-01-01

Pancreatic cancer (PC) evades immune destruction by favoring the development of regulatory T cells (Tregs) that inhibit effector T cells. The transcription factor Ikaros is critical for lymphocyte development, especially T cells. We have previously shown that downregulation of Ikaros occurs as a result of its protein degradation by the ubiquitin-proteasome system in our Panc02 tumor-bearing (TB) mouse model. Mechanistically, we observed a deregulation in the balance between Casein Kinase II (CK2) and protein phosphatase 1 (PP1), which suggested that increased CK2 activity is responsible for regulating Ikaros’ stability in our model. We also showed that this loss of Ikaros expression is associated with a significant decrease in CD4+ and CD8+ T cell percentages but increased CD4+CD25+ Tregs in TB mice. In this study, we evaluated the effects of the dietary flavonoid apigenin (API), on Ikaros expression and T cell immune responses. Treatment of splenocytes from naïve mice with (API) stabilized Ikaros expression and prevented Ikaros downregulation in the presence of murine Panc02 cells in vitro, similar to the proteasome inhibitor MG132. In vivo treatment of TB mice with apigenin (TB-API) improved survival, reduced tumor weights and prevented splenomegaly. API treatment also restored protein expression of some Ikaros isoforms, which may be attributed to its moderate inhibition of CK2 activity from splenocytes of TB-API mice. This partial restoration of Ikaros expression was accompanied by a significant increase in CD4+ and CD8+ T cell percentages and a reduction in Treg percentages in TB-API mice. In addition, CD8+ T cells from TB-API mice produced more IFN-γ and their splenocytes were better able to prime allogeneic CD8+ T cell responses compared to TB mice. These results provide further evidence that Ikaros is regulated by CK2 in our pancreatic cancer model. More importantly, our findings suggest that API may be a possible therapeutic agent for stabilizing Ikaros

Y2-receptor-mediated selective inhibition of slow, inhibitory postsynaptic potential in submucous neurones of guinea-pig caecum.

PubMed Central

Cunningham, S M; Mihara, S; Lees, G M

1994-01-01

1. The subtype of neuropeptide Y receptor mediating the selective inhibition of the slow inhibitory postsynaptic potential (i.p.s.p.) of submucous neurones in guinea-pig caecum was investigated by use of conventional intracellular electrophysiological recording techniques. 2. Neuropeptide Y (NPY) (1-300 nM) was found to depress or abolish reversibly the slow i.p.s.p. evoked by focal stimulation of internodal fibre tracts. At low concentrations (1-30 nM), a reduction in the duration of the slow i.p.s.p. was often apparent before any inhibition of the amplitude of this synaptic potential. 3. These inhibitory effects of NPY were mimicked by peptide YY (PYY; 0.3-100 nM), NPY13-36 (1-300 nM) and NPY22-36 (10-100 nM); [Leu31,Pro34]NPY ([Pro34]NPY) and bovine pancreatic polypeptide (bPP) were without pre- or postsynaptic effects at concentrations of up to 300 nM. The IC50 +/- s.e. mean values for PYY, NPY, and NPY13-36 were 2.7 +/- 0.3, 7.8 +/- 2.1 and 30 +/- 4.8 nM, respectively, and were significantly different from each other. Thus, the apparent rank order of potency was PYY > NPY > NPY13-36 >> [Pro34]NPY and bPP. 4. In concentrations of up to 300 nM, NPY and its analogues had no depressant effects on the active and passive properties of the impaled neurone and did not affect the amplitude or duration of either cholinergic fast synaptic potentials or non-cholinergic, slow excitatory postsynaptic potentials (e.p.s.ps). Furthermore, none of these peptides altered the amplitude or time-course of changes in membrane potential induced by focal application of acetylcholine or noradrenaline.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7858881

[The CK2 inhibitor quninalizarin enhances the anti-proliferative effect of icotinib on EGFR-TKIs-resistant cell lines and its underlying mechanisms].

PubMed

Zhou, Y; Zhang, S; Li, K; Li, Q W; Zhou, F Z; Li, Z Y; Ma, H; Dong, X R; Liu, L; Wu, G; Meng, R

2016-02-01

To explore whether quninalizarin, an specific inhibitor of protein kinase CK2, could sensitize icotinib in EGFR-TKIs (epithelial growth factor receptor-tyrosine kinase inhibitor)-resistant cell lines and uncover the underlying mechanisms. MTT assay was performed to evaluate the inhibitory effect of quninalizarin, icotinib or the combination of both on cell proliferation in several lung adenocarcinoma cell lines. Western blot assay was used to assess if combined inhibition of EGFR and protein kinase CK2 by icotinib and quninalizarin, exerts effect on the expression and phosphorylation of major proteins of EGFR signaling pathways. The IC50 of HCC827, H1650, H1975 and A549 cells for icotinib were (8.07±2.00)μmol/L, (66.01±6.64)μmol/L, (265.60±9.47)μmol/L and (87.88±6.8)μmol/L, respectively, indicating that HCC827 cells are sensitive to icotinib, and the H1650, H1975 and A549 cells are relatively resistant to icotinib. When treated with both quninalizarin and icotinib in the concentration of 50 μmol/L, the viability of H1650, H1975 and A549 cells was (40.64±3.73)%, (65.74±3.27)% and (44.96±0.48)%, respectively, significantly lower than that of H1650, H1975 and A549 cells treated with 50 μmol/L icotinib alone (55.05±1.22)%, (71.98±1.60)% and (61.74±6.18)%, respectively (P<0.01 for all). When treated with both 100 μmol/L quninalizarin and 100 μmol/L icotinib, the viability of H1650, H1975 and A549 ells were (23.35±0.81)%, (55.70±1.03)%, (33.42±1.33)%, respectively, significantly lower than the viability of H1650, H1975 and A549 cells treated with 100 μmol/L icotinib alone (40.57±2.65)%, (62.40±2.05)% and (44.97±8.20)%, respectively, (P<0.01 for all). The two-way ANOVA analysis showed that compared with the viability of EGFR-TKIs-resistant cells (H1650, H1975, A549) treated with 50 μmol/L and 100 μmol/L icotinib alone, the viability of cells treated with icotinib and quinalizarin were significantly suppressed, and the differences were

Nitric oxide-mediated inhibition of taurocholate uptake involves S-nitrosylation of NTCP.

PubMed

Schonhoff, Christopher M; Ramasamy, Umadevi; Anwer, M Sawkat

2011-02-01

The sodium-taurocholate (TC) cotransporting polypeptide (NTCP) facilitates bile formation by mediating sinusoidal Na(+)-TC cotransport. During sepsis-induced cholestasis, there is a decrease in NTCP-dependent uptake of bile acids and an increase in nitric oxide (NO) levels in hepatocytes. In rat hepatocytes NO inhibits Na(+)-dependent uptake of taurocholate. The aim of this study was to extend these findings to human NTCP and to further investigate the mechanism by which NO inhibits TC uptake. Using a human hepatoma cell line stably expressing NTCP (HuH-NTCP), we performed experiments with the NO donors sodium nitroprusside and S-nitrosocysteine and demonstrated that NO inhibits TC uptake in these cells. Kinetic analyses revealed that NO significantly decreased the V(max) but not the K(m) of TC uptake by NTCP, indicating noncompetitive inhibition. NO decreased the amount of NTCP in the plasma membrane, providing a molecular mechanism for the noncompetitive inhibition of TC uptake. One way that NO can modify protein function is through a posttranslational modification known as S-nitrosylation: the binding of NO to cysteine thiols. Using a biotin switch technique we observed that NTCP is S-nitrosylated under conditions in which NO inhibits TC uptake. Moreover, dithiothreitol reversed NO-mediated inhibition of TC uptake and S-nitrosylation of NTCP, indicating that NO inhibits TC uptake via modification of cysteine thiols. In addition, NO treatment led to a decrease in Ntcp phosphorylation. Taken together these results indicate that the inhibition of TC uptake by NO involves S-nitrosylation of NTCP.

Cytokinin is required for escape but not release from auxin mediated apical dominance

PubMed Central

Müller, Dörte; Waldie, Tanya; Miyawaki, Kaori; To, Jennifer PC; Melnyk, Charles W; Kieber, Joseph J; Kakimoto, Tatsuo; Leyser, Ottoline

2015-01-01

Auxin produced by an active primary shoot apex is transported down the main stem and inhibits the growth of the axillary buds below it, contributing to apical dominance. Here we use Arabidopsis thaliana cytokinin (CK) biosynthetic and signalling mutants to probe the role of CK in this process. It is well established that bud outgrowth is promoted by CK, and that CK synthesis is inhibited by auxin, leading to the hypothesis that release from apical dominance relies on an increased supply of CK to buds. Our data confirm that decapitation induces the expression of at least one ISOPENTENYLTRANSFERASE (IPT) CK biosynthetic gene in the stem. We further show that transcript abundance of a clade of the CK-responsive type-A Arabidopsis response regulator (ARR) genes increases in buds following CK supply, and that, contrary to their typical action as inhibitors of CK signalling, these genes are required for CK-mediated bud activation. However, analysis of the relevant arr and ipt multiple mutants demonstrates that defects in bud CK response do not affect auxin-mediated bud inhibition, and increased IPT transcript levels are not needed for bud release following decapitation. Instead, our data suggest that CK acts to overcome auxin-mediated bud inhibition, allowing buds to escape apical dominance under favourable conditions, such as high nitrate availability. Significance Statement It has been proposed that the release of buds from auxin-mediated apical dominance following decapitation requires increased cytokinin biosynthesis and consequent increases in cytokinin supply to buds. Here we show that in Arabidopsis, increases in cytokinin appear to be unnecessary for the release of buds from apical dominance, but rather allow buds to escape the inhibitory effect of apical auxin, thereby promoting bud activation in favourable growth conditions. PMID:25904120

Serum S100A8 and S100A9 Enhance Innate Immune Responses in the Pathogenesis of Baker's Asthma.

PubMed

Pham, Duy Le; Yoon, Moon-Guyng; Ban, Ga-Young; Kim, Seung-Hyun; Kim, Mi-Ae; Ye, Young-Min; Shin, Yoo Seob; Park, Hae-Sim

2015-01-01

S100A8 and S100A9 can be produced by lipopolysaccharide-stimulated granulocytes and provoke an innate immune-mediated airway inflammation. Involvement of S100A8 and S100A9 has been implicated in asthma. To further understand the role of S100A8 and S100A9 during innate immune responses in baker's asthma, we investigated the associations of serum S100A8 and S100A9 with exposure to bakery allergens and polymorphisms of the Toll-like receptor 4 (TLR4) gene. Totally, 381 bakery workers and 100 unexposed healthy controls were recruited. Skin prick tests for bakery allergens were performed. Serum levels of S100A8, S100A9, myeloperoxidase (MPO), tumor necrosis factor (TNF)-α, and interleukin (IL)-8 were measured using ELISA. Predictive values of serum S100A8 and S100A9 in bakery workers were evaluated by receiver-operating characteristic (ROC) curves. Polymorphisms of TLR4 -2027Ax2192;G and -1608Tx2192;C were genotyped. Higher serum levels of S100A8 and S100A9 were noted in bakery workers compared to the normal controls (p < 0.001); however, no significant differences were noted according to work-related symptoms. The area under the ROC curve of serum S100A8 was 0.886 for occupational exposure (p < 0.001). The TLR4 -1608CC genotype was significantly associated with a higher serum S100A8 level (p = 0.025). Serum S100A8 and S100A9 levels were correlated with serum levels of MPO (r = 0.396 and 0.189, respectively), TNF-α (r = 0.536 and 0.280, respectively), and IL-8 (r = 0.540 and 0.205, respectively; p < 0.001 for all). S100A8 and S100A9 are involved in innate immune responses under the regulation of TLR4 polymorphisms in baker's asthma pathogenesis. Serum S100A8 could be a potential biomarker for predicting occupational exposure to wheat flour in bakery workers. © 2016 S. Karger AG, Basel.

Tetraspanin TM4SF5 mediates loss of contact inhibition through epithelial-mesenchymal transition in human hepatocarcinoma

PubMed Central

Lee, Sin-Ae; Lee, Sung-Yul; Cho, Ik-Hyun; Oh, Min-A; Kang, Eun-Sil; Kim, Yong-Bae; Seo, Woo Duck; Choi, Suyong; Nam, Ju-Ock; Tamamori-Adachi, Mimi; Kitajima, Shigetaka; Ye, Sang-Kyu; Kim, Semi; Hwang, Yoon-Jin; Kim, In-San; Park, Ki Hun; Lee, Jung Weon

2008-01-01

The growth of normal cells is arrested when they come in contact with each other, a process known as contact inhibition. Contact inhibition is lost during tumorigenesis, resulting in uncontrolled cell growth. Here, we investigated the role of the tetraspanin transmembrane 4 superfamily member 5 (TM4SF5) in contact inhibition and tumorigenesis. We found that TM4SF5 was overexpressed in human hepatocarcinoma tissue. TM4SF5 expression in clinical samples and in human hepatocellular carcinoma cell lines correlated with enhanced p27Kip1 expression and cytosolic stabilization as well as morphological elongation mediated by RhoA inactivation. These TM4SF5-mediated effects resulted in epithelial-mesenchymal transition (EMT) via loss of E-cadherin expression. The consequence of this was aberrant cell growth, as assessed by S-phase transition in confluent conditions, anchorage-independent growth, and tumor formation in nude mice. The TM4SF5-mediated effects were abolished by suppressing the expression of either TM4SF5 or cytosolic p27Kip1, as well as by reconstituting the expression of E-cadherin. Our observations have revealed a role for TM4SF5 in causing uncontrolled growth of human hepatocarcinoma cells through EMT. PMID:18357344

Visualization of Tumor-Immune Interaction - Target-Specific Imaging of S100A8/A9 Reveals Pre-Metastatic Niche Establishment.

PubMed

Eisenblaetter, Michel; Flores-Borja, Fabian; Lee, Jae Jin; Wefers, Christina; Smith, Hannah; Hueting, Rebekka; Cooper, Margaret S; Blower, Philip J; Patel, Dominic; Rodriguez-Justo, Manuel; Milewicz, Hanna; Vogl, Thomas; Roth, Johannes; Tutt, Andrew; Schaeffter, Tobias; Ng, Tony

2017-01-01

Background Systemic cancer spread is preceded by the establishment of a permissive microenvironment in the target tissue of metastasis - the premetastatic niche. As crucial players in establishment of the pre-metastatic niche, myeloid derived suppressor cells (MDSC) release S100A8/A9, an exosomal protein that contributes to metastasis, angiogenesis, and immune suppression. We report the application of antibody-based single-photon emission computed tomography (SPECT) for detection of S100A8/A9 in vivo as an imaging marker for pre-metastatic tissue priming. Methods A syngeneic model system for invasive breast cancer with (4T1.2) or without (67NR) the tendency to form lung metastasis was established in BALB/c mice. A SPECT-probe has been generated and tested for visualization of S100A9 release. Tumor-associated changes in numbers and fuction of immune cells in pre-metastatic tissue were evaluated by flow cytometry and confocal microscopy. Results S100A8/A9 imaging reflected MDSC abundance and the establishment of an immunosuppressive environment in pre-metastatic lung tissue (activity 4T1.2 vs. healthy control: 0.95 vs. 0.45 %ID; p<0.001). The S100A8/A9 imaging signal in the pre-metastatic lung correlated with the subsequent metastatic tumor burden in the same organ (r 2 =0.788; p<0.0001). CCL2 blockade and the consecutive inhibition of premetastatic niche establishment was clearly depicted by S100A9-SPECT (lung activity untreated vs. treated: 2 vs, 1.4 %ID). Conclusion We report S100A8/A9 as a potent imaging biomarker for tumor-mediated immune remodeling with potential applications in basic research and clinical oncology.

Visualization of Tumor-Immune Interaction - Target-Specific Imaging of S100A8/A9 Reveals Pre-Metastatic Niche Establishment

PubMed Central

Eisenblaetter, Michel; Flores-Borja, Fabian; Lee, Jae Jin; Wefers, Christina; Smith, Hannah; Hueting, Rebekka; Cooper, Margaret S; Blower, Philip J; Patel, Dominic; Rodriguez-Justo, Manuel; Milewicz, Hanna; Vogl, Thomas; Roth, Johannes; Tutt, Andrew; Schaeffter, Tobias; Ng, Tony

2017-01-01

Background Systemic cancer spread is preceded by the establishment of a permissive microenvironment in the target tissue of metastasis - the premetastatic niche. As crucial players in establishment of the pre-metastatic niche, myeloid derived suppressor cells (MDSC) release S100A8/A9, an exosomal protein that contributes to metastasis, angiogenesis, and immune suppression. We report the application of antibody-based single-photon emission computed tomography (SPECT) for detection of S100A8/A9 in vivo as an imaging marker for pre-metastatic tissue priming. Methods A syngeneic model system for invasive breast cancer with (4T1.2) or without (67NR) the tendency to form lung metastasis was established in BALB/c mice. A SPECT-probe has been generated and tested for visualization of S100A9 release. Tumor-associated changes in numbers and fuction of immune cells in pre-metastatic tissue were evaluated by flow cytometry and confocal microscopy. Results S100A8/A9 imaging reflected MDSC abundance and the establishment of an immunosuppressive environment in pre-metastatic lung tissue (activity 4T1.2 vs. healthy control: 0.95 vs. 0.45 %ID; p<0.001). The S100A8/A9 imaging signal in the pre-metastatic lung correlated with the subsequent metastatic tumor burden in the same organ (r2=0.788; p<0.0001). CCL2 blockade and the consecutive inhibition of premetastatic niche establishment was clearly depicted by S100A9-SPECT (lung activity untreated vs. treated: 2 vs, 1.4 %ID). Conclusion We report S100A8/A9 as a potent imaging biomarker for tumor-mediated immune remodeling with potential applications in basic research and clinical oncology. PMID:28744322

SMAD4 loss enables EGF, TGFβ1 and S100A8/A9 induced activation of critical pathways to invasion in human pancreatic adenocarcinoma cells

PubMed Central

Moz, Stefania; Basso, Daniela; Bozzato, Dania; Galozzi, Paola; Navaglia, Filippo; Negm, Ola H.; Arrigoni, Giorgio; Zambon, Carlo-Federico; Padoan, Andrea; Tighe, Paddy; Todd, Ian; Franchin, Cinzia; Pedrazzoli, Sergio; Punzi, Leonardo; Plebani, Mario

2016-01-01

Epidermal Growth Factor (EGF) receptor overexpression, KRAS, TP53, CDKN2A and SMAD4 mutations characterize pancreatic ductal adenocarcinoma. This mutational landscape might influence cancer cells response to EGF, Transforming Growth Factor β1 (TGFβ1) and stromal inflammatory calcium binding proteins S100A8/A9. We investigated whether chronic exposure to EGF modifies in a SMAD4-dependent manner pancreatic cancer cell signalling, proliferation and invasion in response to EGF, TGFβ1 and S100A8/A9. BxPC3, homozigously deleted (HD) for SMAD4, and BxPC3-SMAD4+ cells were or not stimulated with EGF (100 ng/mL) for three days. EGF pre-treated and non pretreated cells were stimulated with a single dose of EGF (100 ng/mL), TGFβ1 (0,02 ng/mL), S100A8/A9 (10 nM). Signalling pathways (Reverse Phase Protein Array and western blot), cell migration (Matrigel) and cell proliferation (XTT) were evaluated. SMAD4 HD constitutively activated ERK and Wnt/β-catenin, while inhibiting PI3K/AKT pathways. These effects were antagonized by chronic EGF, which increased p-BAD (anti-apoptotic) in response to combined TGFβ1 and S100A8/A9 stimulation. SMAD4 HD underlied the inhibition of NF-κB and PI3K/AKT in response to TGFβ1 and S100A8/A9, which also induced cell migration. Chronic EGF exposure enhanced cell migration of both BxPC3 and BxPC3-SMAD4+, rendering the cells less sensitive to the other inflammatory stimuli. In conclusion, SMAD4 HD is associated with the constitutive activation of the ERK and Wnt/β-catenin signalling pathways, and favors the EGF-induced activation of multiple signalling pathways critical to cancer proliferation and invasion. TGFβ1 and S100A8/A9 mainly inhibit NF-κB and PI3K/AKT pathways and, when combined, sinergize with EGF in enhancing anti-apoptotic p-BAD in a SMAD4-dependent manner. PMID:27655713

CIGB-300, an anti-CK2 peptide, inhibits angiogenesis, tumor cell invasion and metastasis in lung cancer models.

PubMed

Benavent Acero, Fernando; Capobianco, Carla S; Garona, Juan; Cirigliano, Stéfano M; Perera, Yasser; Urtreger, Alejandro J; Perea, Silvio E; Alonso, Daniel F; Farina, Hernan G

2017-05-01

Casein kinase 2 (CK2) is overexpressed in several types of cancer. It has more than 300 substrates mainly involved in DNA reparation and replication, chromatin remodeling and cellular growth. In recent years CK2 became an interesting target for anticancer drug development. CIGB-300 is a peptidic inhibitor of CK2 activity, designed to bind to the phospho-acceptor domain of CK2 substrates, impairing the correct phosphorylation by the enzyme. The aim of this work was to explore the antitumor effects of this inhibitor in preclinical lung cancer models. Human H125 and murine 3LL Lewis lung carcinoma cell lines were used to evaluate the effect of CIGB-300 treatment in vitro. For this purpose, adhesion, migration and invasion capabilities of cancer cells were tested. Proteolytic activity of tumor cell-secreted uPA and MMP after CIGB-300 incubation was also analyzed. In vivo anticancer efficacy of the peptide was evaluated using experimental and spontaneous lung colonization assays in C57BL/6 mice. Finally, in order to test the effect of CIGB-300 on tumor cell-induced angiogenesis, a modified Matrigel plug assay was conducted. We demonstrate that treatment with low micromolar concentrations of CIGB-300 caused a drastic reduction of adhesion, migration and invasion of lung cancer cells. Reduced invasiveness after CIGB-300 incubation was associated with decreased proteolytic activity of tumor cell-conditioned medium. In vivo, intravenous administration of CIGB-300 (10mg/kg) markly decreased lung colonization and metastasis development of 3LL cells. Interestingly, after 5days of systemic treatment with CIGB-300, tumor cell-driven neovascularization was significantly reduced in comparison to control group. Altogether our data suggest an important role of CK2 in lung tumor development, suggesting a potential use of CIGB-300 as a novel therapeutic agent against lung cancer. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Id2 Complexes with the SNAG Domain of Snai1 Inhibiting Snai1-Mediated Repression of Integrin β4

PubMed Central

Chang, Cheng; Yang, Xiaofang; Pursell, Bryan

2013-01-01

The epithelial-mesenchymal transition (EMT) is a fundamental process that underlies development and cancer. Although the EMT involves alterations in the expression of specific integrins that mediate stable adhesion to the basement membrane, such as α6β4, the mechanisms involved are poorly understood. Here, we report that Snai1 inhibits β4 transcription by increasing repressive histone modification (trimethylation of histone H3 at K27 [H3K27Me3]). Surprisingly, Snai1 is expressed and localized in the nucleus in epithelial cells, but it does not repress β4. We resolved this paradox by discovering that Id2 complexes with the SNAG domain of Snai1 on the β4 promoter and constrains the repressive function of Snai1. Disruption of the complex by depleting Id2 resulted in Snai1-mediated β4 repression with a concomitant increase in H3K27Me3 modification on the β4 promoter. These findings establish a novel function for Id2 in regulating Snai1 that has significant implications for the regulation of epithelial gene expression. PMID:23878399

Grb2 mediates semaphorin-4D-dependent RhoA inactivation.

PubMed

Sun, Tianliang; Krishnan, Rameshkumar; Swiercz, Jakub M

2012-08-01

Signaling through the semaphorin 4D (Sema4D) receptor plexin-B1 is modulated by its interaction with tyrosine kinases ErbB-2 and Met. In cells expressing the plexin-B1-ErbB-2 receptor complex, ligand stimulation results in the activation of small GTPase RhoA and stimulation of cellular migration. By contrast, in cells expressing plexin-B1 and Met, ligand stimulation results in an association with the RhoGTPase-activating protein p190 RhoGAP and subsequent RhoA inactivation--a process that involves the tyrosine phosphorylation of plexin-B1 by Met. Inactivation of RhoA is necessary for Sema4D-mediated inhibition of cellular migration. It is, however, unknown how plexin-B1 phosphorylation regulates RhoGAP interaction and activity. Here we show that the activation of plexin-B1 by Sema4D and its subsequent tyrosine phosphorylation by Met creates a docking site for the SH2 domain of growth factor receptor bound-2 (Grb2). Grb2 is thereby recruited into the plexin-B1 receptor complex and, through its SH3 domain, interacts with p190 RhoGAP and mediates RhoA deactivation. Phosphorylation of plexin-B1 by Met and the recruitment of Grb2 have no effect on the R-RasGAP activity of plexin-B1, but are required for Sema4D-induced, RhoA-dependent antimigratory effects of Sema4D on breast cancer cells. These data show Grb2 as a direct link between plexin and p190-RhoGAP-mediated downstream signaling.

Curcumin inhibits urothelial tumor development by suppressing IGF2 and IGF2-mediated PI3K/AKT/mTOR signaling pathway.

PubMed

Tian, Binqiang; Zhao, Yingmei; Liang, Tao; Ye, Xuxiao; Li, Zuowei; Yan, Dongliang; Fu, Qiang; Li, Yonghui

2017-08-01

We have previously reported that curcumin inhibits urothelial tumor development in a rat bladder carcinogenesis model. In this study, we report that curcumin inhibits urothelial tumor development by suppressing IGF2 and IGF2-mediated PI3K/AKT/mTOR signaling pathway. Curcumin inhibits IGF2 expression at the transcriptional level and decreases the phosphorylation levels of IGF1R and IRS-1 in bladder cancer cells and N-methyl-N-nitrosourea (MNU)-induced urothelial tumor tissue. Ectopic expression of IGF2 and IGF1R, but not IGF1, in bladder cancer cells restored this process, suggesting that IGF2 is a target of curcumin. Moreover, introduction of constitutively active AKT1 abolished the inhibitory effect of curcumin on cell proliferation, migration, and restored the phosphorylation levels of 4E-BP1 and S6K1, suggesting that curcumin functions via suppressing IGF2-mediated AKT/mTOR signaling pathway. In summary, our results reveal that suppressing IGF2 and IGF2-mediated PI3K/AKT/mTOR signaling pathway is one of the mechanisms of action of curcumin. Our findings suggest a new therapeutic strategy against human bladder cancer caused by aberrant activation of IGF2, which are useful for translational application of curcumin.

Vitamin K3 (menadione) redox cycling inhibits cytochrome P450-mediated metabolism and inhibits parathion intoxication

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jan, Yi-Hua; Richardson, Jason R., E-mail: jricha3@eohsi.rutgers.edu; Baker, Angela A.

Parathion, a widely used organophosphate insecticide, is considered a high priority chemical threat. Parathion toxicity is dependent on its metabolism by the cytochrome P450 system to paraoxon (diethyl 4-nitrophenyl phosphate), a cytotoxic metabolite. As an effective inhibitor of cholinesterases, paraoxon causes the accumulation of acetylcholine in synapses and overstimulation of nicotinic and muscarinic cholinergic receptors, leading to characteristic signs of organophosphate poisoning. Inhibition of parathion metabolism to paraoxon represents a potential approach to counter parathion toxicity. Herein, we demonstrate that menadione (methyl-1,4-naphthoquinone, vitamin K3) is a potent inhibitor of cytochrome P450-mediated metabolism of parathion. Menadione is active in redox cycling,more » a reaction mediated by NADPH-cytochrome P450 reductase that preferentially uses electrons from NADPH at the expense of their supply to the P450s. Using human recombinant CYP 1A2, 2B6, 3A4 and human liver microsomes, menadione was found to inhibit the formation of paraoxon from parathion. Administration of menadione bisulfite (40 mg/kg, ip) to rats also reduced parathion-induced inhibition of brain cholinesterase activity, as well as parathion-induced tremors and the progression of other signs and symptoms of parathion poisoning. These data suggest that redox cycling compounds, such as menadione, have the potential to effectively mitigate the toxicity of organophosphorus pesticides including parathion which require cytochrome P450-mediated activation. - Highlights: • Menadione redox cycles with cytochrome P450 reductase and generates reactive oxygen species. • Redox cycling inhibits cytochrome P450-mediated parathion metabolism. • Short term administration of menadione inhibits parathion toxicity by inhibiting paraoxon formation.« less

NOD2 Down-Regulates Colonic Inflammation by IRF4-Mediated Inhibition of K63-Linked Polyubiquitination of RICK and TRAF6

PubMed Central

Watanabe, Tomohiro; Asano, Naoki; Meng, Guangxun; Yamashita, Kouhei; Arai, Yasuyuki; Sakurai, Toshiharu; Kudo, Masatoshi; Fuss, Ivan J; Kitani, Atsushi; Shimosegawa, Tooru; Chiba, Tsutomu; Strober, Warren

2014-01-01

It is well established that polymorphisms of the nucleotide-binding oligomerization domain 2 (NOD2) gene, a major risk factor in Crohn's disease (CD), lead to loss of NOD2 function. However, a molecular explanation of how such loss of function leads to increased susceptibility to CD has remained unclear. In a previous study exploring this question we reported that activation of NOD2 in human dendritic cells by its ligand, muramyl dipeptide (MDP) negatively regulates Toll-like receptor (TLR)-mediated inflammatory responses. Here we show that NOD2 activation results in increased interferon regulatory factor 4 (IRF4) expression and binding to TNF receptor associated factor 6 (TRAF6) and receptor interacting serine-threonine kinase (RICK). We then show that such binding leads to IRF4-mediated inhibition of Lys63-linked polyubiquitination of TRAF6 and RICK and thus to down-regulation of NF-κB activation. Finally, we demonstrate that protection of mice from the development of experimental colitis by MDP or IRF4 administration is accompanied by similar IRF4-mediated effects on polyubiquitination of TRAF6 and RICK in colonic lamina propria mononuclear cells. These findings thus define a mechanism of NOD2-mediated regulation of innate immune responses to intestinal microflora that could explain the relation of NOD2 polymorphisms and resultant NOD2 dysfunction to CD. PMID:24670424

Smad4-Mediated Signaling Inhibits Intestinal Neoplasia by Inhibiting Expression of β-Catenin

PubMed Central

Freeman, Tanner J.; Smith, J. Joshua; Chen, Xi; Washington, M. Kay; Roland, Joseph T.; Means, Anna L.; Eschrich, Steven A.; Yeatman, Timothy J.; Deane, Natasha G.; Beauchamp, R. Daniel

2012-01-01

Background & Aims Mutational inactivation of APC is an early event in colorectal cancer (CRC) progression that affects the stability and increases the activity of β-catenin, a mediator of Wnt signaling. CRC progression also involves inactivation of signaling via transforming growth factor (TGF)β and bone morphenogenic protein (BMP), which are tumor suppressors. However, the interactions between these pathways are not clear. We investigated the effects of loss of the transcription factor Smad4 loss on levels of β-catenin mRNA and Wnt signaling. Methods We used microarray analysis to associate levels of Smad4 and β-catenin mRNA in colorectal tumor samples from 250 patients. We performed oligonucleotide-mediated knockdown of Smad4 in human embryonic kidney (HEK293T) and in HCT116 colon cancer cells and transgenically expressed Smad4 in SW480 colon cancer cells. We analyzed adenomas from (APCΔ1638/+) and (APCΔ1638/+)x(K19CreERT2Smad4lox/lox) mice using laser-capture microdissection. Results In human CRC samples, reduced levels of Smad4 correlated with increased levels of β-catenin mRNA. In Smad4-depleted cell lines, levels of β-catenin mRNA and Wnt signaling increased. Inhibition of BMP or depletion of Smad4 in HEK293T cells increased binding of RNA polymerase II to the β-catenin gene. Expression of Smad4 in SW480 cells reduced Wnt signaling and levels of β-catenin mRNA. In mice with heterozygous disruption of Apc(APCΔ1638/+), Smad4-deficient intestinal adenomas had increased levels of β-catenin mRNA and expression of Wnt target genes, compared with adenomas from APCΔ1638/+mice that expressed Smad4. Conclusions Transcription of β-catenin is inhibited by BMP signaling to Smad4. These findings provide important information about the interaction among TGF-β, BMP, and Wnt signaling pathways in CRC progression. PMID:22115830

S100A8 and S100A9 Induce Cytokine Expression and Regulate the NLRP3 Inflammasome via ROS-Dependent Activation of NF-κB1

PubMed Central

Simard, Jean-Christophe; Cesaro, Annabelle; Chapeton-Montes, Julie; Tardif, Mélanie; Antoine, Francis; Girard, Denis; Tessier, Philippe A.

2013-01-01

S100A8 and S100A9 are cytoplasmic proteins expressed by phagocytes. High concentrations of these proteins have been correlated with various inflammatory conditions, including autoimmune diseases such as rheumatoid arthritis and Crohn’s disease, as well as autoinflammatory diseases. In the present study, we examined the effects of S100A8 and S100A9 on the secretion of cytokines and chemokines from PBMCs. S100A8 and S100A9 induced the secretion of cytokines such as IL-6, IL-8, and IL-1β. This secretion was associated with the activation and translocation of the transcription factor NF-κB. Inhibition studies using antisense RNA and the pharmacological agent BAY-117082 confirmed the involvement of NF-κB in IL-6, IL-8, and IL-1β secretion. S100A8- and S100A9-mediated activation of NF-κB, the NLR family, pyrin domain-containing 3 (NLRP3) protein, and pro-IL-1β expression was dependent on the generation of reactive oxygen species. This effect was synergistically enhanced by ATP, a known inflammasome activator. These results suggest that S100A8 and S100A9 enhance the inflammatory response by inducing cytokine secretion of PBMCs. PMID:23977231

Differential release and deposition of S100A8/A9 proteins in inflamed upper airway tissue.

PubMed

Van Crombruggen, Koen; Vogl, Thomas; Pérez-Novo, Claudina; Holtappels, Gabriele; Bachert, Claus

2016-01-01

Intracellular Ca(2+)-binding S100A8/A9 proteins gain novel functions when released during inflammation. The exact outcome of their extracellular function depends on the local tissue environment in which they are released; both anti-inflammatory and pro-inflammatory responses are described, modulating the immune system by binding Toll-like receptor (TLR)-4 or the receptor for advanced glycation end-products (RAGE). However, the contribution of the proteins in the pathophysiology of chronic rhinosinusitis (CRS) remains unclear.Homomeric S100A8 and S100A9, and heteromeric S100A8/A9 proteins were evaluated in CRS with/without nasal polyps (CRSw/sNP) and controls. Functional responses were assessed in polyp tissue stimulated with S100 proteins in the presence of TLR-4 and RAGE blocking antibodies.S100A8, S100A9 and S100A8/A9 protein levels were significantly higher in CRSwNP patients, showing increased deposition on extracellular matrix (ECM) structures of CRSwNP tissue in contrast to CRSsNP and controls. In the presence of Staphylococcus aureus, S100A8/A9 is released from neutrophils and from the ECM. Extracellular S100A8 and S100A9 proteins induced increased levels of diverse inflammatory mediators via TLR-4 engagement.The inflammatory/remodelling characteristics of CRSwNP specifically allow increased retention of S100A8, S100A9 and S100A8/A9 proteins in the ECM of CRSwNP tissue. Upon release, homodimeric proteins act as a local danger signal inducing inflammatory mediators, predominantly via TLR-4 activation. Copyright ©ERS 2016.

S100A4 is frequently overexpressed in lung cancer cells and promotes cell growth and cell motility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Na; Sato, Daisuke; Saiki, Yuriko

2014-05-09

Highlights: • We observed frequent overexpression of S100A4 in lung cancer cell lines. • Knockdown of S100A4 suppressed proliferation in lung cancer cells. • Forced expression of S100A4 accelerated cell motility in lung cancer cells. • PRDM2 was found to be one of the downstream suppressed genes of S100A4. - Abstract: S100A4, a small calcium-binding protein belonging to the S100 protein family, is commonly overexpressed in a variety of tumor types and is widely accepted to associate with metastasis by regulating the motility and invasiveness of cancer cells. However, its biological role in lung carcinogenesis is largely unknown. In thismore » study, we found that S100A4 was frequently overexpressed in lung cancer cells, irrespective of histological subtype. Then we performed knockdown and forced expression of S100A4 in lung cancer cell lines and found that specific knockdown of S100A4 effectively suppressed cell proliferation only in lung cancer cells with S100A4-overexpression; forced expression of S100A4 accelerated cell motility only in S100A4 low-expressing lung cancer cells. PRDM2 and VASH1, identified as novel upregulated genes by microarray after specific knockdown of S100A4 in pancreatic cancer, were also analyzed, and we found that PRDM2 was significantly upregulated after S100A4-knockdown in one of two analyzed S100A4-overexpressing lung cancer cells. Our present results suggest that S100A4 plays an important role in lung carcinogenesis by means of cell proliferation and motility by a pathway similar to that in pancreatic cancer.« less

Autoinhibitory regulation of S100A8/S100A9 alarmin activity locally restricts sterile inflammation.

PubMed

Vogl, Thomas; Stratis, Athanasios; Wixler, Viktor; Völler, Tom; Thurainayagam, Sumita; Jorch, Selina K; Zenker, Stefanie; Dreiling, Alena; Chakraborty, Deblina; Fröhling, Mareike; Paruzel, Peter; Wehmeyer, Corinna; Hermann, Sven; Papantonopoulou, Olympia; Geyer, Christiane; Loser, Karin; Schäfers, Michael; Ludwig, Stephan; Stoll, Monika; Leanderson, Tomas; Schultze, Joachim L; König, Simone; Pap, Thomas; Roth, Johannes

2018-05-01

Autoimmune diseases, such as psoriasis and arthritis, show a patchy distribution of inflammation despite systemic dysregulation of adaptive immunity. Thus, additional tissue-derived signals, such as danger-associated molecular patterns (DAMPs), are indispensable for manifestation of local inflammation. S100A8/S100A9 complexes are the most abundant DAMPs in many autoimmune diseases. However, regulatory mechanisms locally restricting DAMP activities are barely understood. We now unravel for the first time, to our knowledge, a mechanism of autoinhibition in mice and humans restricting S100-DAMP activity to local sites of inflammation. Combining protease degradation, pull-down assays, mass spectrometry, and targeted mutations, we identified specific peptide sequences within the second calcium-binding EF-hands triggering TLR4/MD2-dependent inflammation. These binding sites are free when S100A8/S100A9 heterodimers are released at sites of inflammation. Subsequently, S100A8/S100A9 activities are locally restricted by calcium-induced (S100A8/S100A9)2 tetramer formation hiding the TLR4/MD2-binding site within the tetramer interphase, thus preventing undesirable systemic effects. Loss of this autoinhibitory mechanism in vivo results in TNF-α-driven fatal inflammation, as shown by lack of tetramer formation in crossing S100A9-/- mice with 2 independent TNF-α-transgene mouse strains. Since S100A8/S100A9 is the most abundant DAMP in many inflammatory diseases, specifically blocking the TLR4-binding site of active S100 dimers may represent a promising approach for local suppression of inflammatory diseases, avoiding systemic side effects.

Adsorption of Potassium on the MoS2(100) Surface: A First-Principles Investigation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andersen, Amity; Kathmann, Shawn M.; Lilga, Michael A.

2011-04-15

Periodic density functional theory calculations were performed to investigate the interaction that potassium with the Mo and S edges of the MoS2(100) surface. Both neutral and cationic (+1) charged potassium-promoted systems at different sulfur coverages were considered. Our calculations indicate that the potassium atom readily donates its single 4s valence electron to the MoS2 structure for the neutral potassium-promoted system, and the neutral and cationic potassium-promoted systems demonstrate a similar adsorption behavior. Moreover, potassium changes the magnetic properties known to occur at the metallic edge surface, which have implications for electron spin dependent surface characterization methods (i.e., electron spin/paramagnetic spectroscopy).more » Potassium in both the neutral and cationic systems tends to maximize its interactions with the available sulfur atoms at the edge surface, preferring sites over four-fold S hollows on fully sulfided Mo and S edges and over the interstitial gap where two to four edge surface S atoms are available for coordination. As the potassium coverage increases, the adsorption energy per potassium atom, surface work function, and transfer of the K 4s electron to the MoS2(100) surface decreases, which is in line with an increased metallization of the potassium adlayer. The potassium adlayer tends to form chains along the interstitial with K-K distances ~1 Å, which is notably less than those of bulk bcc K metal (4.61 Å). Density of states for the potassium-saturated surface suggests enhanced involvement of broad K 3d states beginning just above the Fermi level. Potassium-promotion of MoS2(100) has implications for alcohol catalysis: increasing the surface basicity by increasing the electron charge of the surface, providing hydrogenation-promoting CO site, blocking edge surface that dissociate CO and lead to methanation, and limiting H2 dissociative adsorption to the edge surface and possibly inhibiting the H2

Discovery of N6-phenyl-1H-pyrazolo[3,4-d]pyrimidine-3,6-diamine derivatives as novel CK1 inhibitors using common-feature pharmacophore model based virtual screening and hit-to-lead optimization.

PubMed

Yang, Ling-Ling; Li, Guo-Bo; Yan, Heng-Xiu; Sun, Qi-Zheng; Ma, Shuang; Ji, Pan; Wang, Ze-Rong; Feng, Shan; Zou, Jun; Yang, Sheng-Yong

2012-10-01

Aberrant activation of casein kinase 1 (CK1) has been demonstrated to be implicated in the pathogenesis of cancer and various central nervous system disorders. Discovery of CK1 inhibitors has thus attracted much attention in recent years. In this account, we describe the discovery of N6-phenyl-1H-pyrazolo[3,4-d]pyrimidine-3,6-diamine derivatives as novel CK1 inhibitors. An optimal common-feature pharmacophore hypothesis, termed Hypo2, was firstly generated, followed by virtual screening using Hypo2 against several chemical databases. One of the best hit compounds, N6-(4-chlorophenyl)-1H-pyrazolo[3,4-d]pyrimidine-3,6-diamine, was chosen for the subsequent hit-to-lead optimization under the guide of Hypo2, which led to the discovery of a new lead compound (1-(3-(3-amino-1H-pyrazolo[3,4-d]pyrimidin-6-ylamino)phenyl)-3-(3-chloro-4-fluorophenyl)urea) that potently inhibits CK1 with an IC(50) value of 78 nM. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Biosurfactant mannosyl-erythritol lipid inhibits secretion of inflammatory mediators from RBL-2H3 cells.

PubMed

Morita, Yosuke; Tadokoro, Satoshi; Sasai, Masao; Kitamoto, Dai; Hirashima, Naohide

2011-12-01

Biosurfactant mannosyl-erythritol lipids (MELs) are glycolipids produced by microbes that have various biological activities. It has been reported that MELs exhibit excellent surface-activity and also various bioactivities, such as induction of cell differentiation and apoptosis. However, little is known about their action related to drug discovery or drug seeds. We investigated the effects of MELs on the secretion of inflammatory mediators from mast cells that play a central role in allergic responses. Mast cells secrete three kinds of inflammatory mediators and we quantified these secreted mediators by photometer or ELISA. The action mechanisms of MELs were studied by Ca(2+)-sensitive fluorescence dye and Western blotting of phosphorylated proteins. MELs inhibited exocytotic release by antigen stimulation in a dose-dependent manner. We also found that MELs inhibited antigen-induced secretion of leukotriene C(4) and cytokine TNF-α (tumor necrosis factor-α). The inhibitory action of MELs on mediator secretion was mediated by inhibition of Ca(2+) increase, phosphorylation of MAP kinases and SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) that serve as a molecular machinery for exocytotic membrane fusion. MELs have anti-inflammatory action inhibiting the secretion of inflammatory mediators from mast cells. MELs affects two of major intracellular signaling pathways including Ca(2+) increase and MAP kinases. MELs also inhibited the phosphorylation of SNARE proteins that is crucial for not only exocytosis but also intracellular vesicular trafficking. 2011 Elsevier B.V. All rights reserved.

Two Ck1δ transcripts regulated by m6A methylation code for two antagonistic kinases in the control of the circadian clock

PubMed Central

Fustin, Jean-Michel; Kojima, Rika; Itoh, Kakeru; Chang, Hsin-Yi; Shiqi, Ye; Zhuang, Bowen; Oji, Asami; Gibo, Shingo; Narasimamurthy, Rajesh; Kurosawa, Gen; Doi, Masao; Manabe, Ichiro; Ishihama, Yasushi; Okamura, Hitoshi

2018-01-01

The N6-methylation of internal adenosines (m6A) in mRNA has been quantified and localized throughout the transcriptome. However, the physiological significance of m6A in most highly methylated mRNAs is unknown. It was demonstrated previously that the circadian clock, based on transcription-translation negative feedback loops, is sensitive to the general inhibition of m6A. Here, we show that the Casein Kinase 1 Delta mRNA (Ck1δ), coding for a critical kinase in the control of circadian rhythms, cellular growth, and survival, is negatively regulated by m6A. Inhibition of Ck1δ mRNA methylation leads to increased translation of two alternatively spliced CK1δ isoforms, CK1δ1 and CK1δ2, uncharacterized until now. The expression ratio between these isoforms is tissue-specific, CK1δ1 and CK1δ2 have different kinase activities, and they cooperate in the phosphorylation of the circadian clock protein PER2. While CK1δ1 accelerates the circadian clock by promoting the decay of PER2 proteins, CK1δ2 slows it down by stabilizing PER2 via increased phosphorylation at a key residue on PER2 protein. These observations challenge the previously established model of PER2 phosphorylation and, given the multiple functions and targets of CK1δ, the existence of two isoforms calls for a re-evaluation of past research when CK1δ1 and CK1δ2 were simply CK1δ. PMID:29784786

S100A8/A9 regulates MMP-2 expression and invasion and migration by carcinoma cells.

PubMed

Silva, Emmanuel J; Argyris, Prokopios P; Zou, Xianqiong; Ross, Karen F; Herzberg, Mark C

2014-10-01

Intracellular calprotectin (S100A8/A9) functions in the control of the cell cycle checkpoint at G2/M. Dysregulation of S100A8/A9 appears to cause loss of the checkpoint, which frequently characterizes head and neck squamous cell carcinoma (HNSCC). In the present study, we analyzed carcinoma cells for other S100A8/A9-directed changes in malignant phenotype. Using a S100A8/A9-negative human carcinoma cell line (KB), transfection to express S100A8 and S100A9 caused selective down-regulation of MMP-2 and inhibited in vitro invasion and migration. Conversely, silencing of endogenous S100A8 and S100A9 expression in TR146 cells, a well-differentiated HNSCC cell line, increased MMP-2 activity and in vitro invasion and migration. When MMP-2 expression was silenced, cells appeared to assume a less malignant phenotype. To more closely model the architecture of cell growth in vivo, cells were grown in a 3D collagen substrate, which was compared to 2D. Growth on 3D substrates caused greater MMP-2 expression. Whereas hypermethylation of CpG islands occurs frequently in HNSCC, S100A8/A9-dependent regulation of MMP-2 could not be explained by modification of the upstream promoters of MMP2 or TIMP2. Collectively, these results suggest that intracellular S100A8/A9 contributes to the cancer cell phenotype by modulating MMP-2 expression and activity to regulate cell migration and mobility. Published by Elsevier Ltd.

S100A8/A9 regulates MMP-2 expression and invasion and migration by carcinoma cells

PubMed Central

Silva, Emmanuel J.; Argyris, Prokopios P.; Zou, Xianqiong; Ross, Karen F.; Herzberg, Mark C.

2014-01-01

Intracellular calprotectin (S100A8/A9) functions in the control of the cell cycle checkpoint at G2/M. Dysregulation of S100A8/A9 appears to cause loss of the checkpoint, which frequently characterizes head and neck squamous cell carcinoma (HNSCC). In the present study, we analyzed carcinoma cells for other S100A8/A9-directed changes in malignant phenotype. Using a S100A8/A9-negative human carcinoma cell line (KB), transfection to express S100A8 and S100A9 caused selective down-regulation of MMP-2 and inhibited in vitro invasion and migration. Conversely, silencing of endogenous S100A8 and S100A9 expression in TR146 cells, a well-differentiated HNSCC cell line, increased MMP-2 activity and in vitro invasion and migration. When MMP-2 expression was silenced, cells appeared to assume a less malignant phenotype. To more closely model the architecture of cell growth in vivo, cells were grown in a 3D collagen substrate, which was compared to 2D. Growth on 3D substrates caused greater MMP-2 expression. Whereas hypermethylation of CpG islands occurs frequently in HNSCC, S100A8/A9-dependent regulation of MMP-2 could not be explained by modification of the upstream promoters of MMP2 or TIMP2. Collectively, these results suggest that intracellular S100A8/A9 contributes to the cancer cell phenotype by modulating MMP-2 expression and activity to regulate cell migration and mobility. PMID:25236491

Emergence of Protein Kinase CK2 as a Key Target in Cancer Therapy

PubMed Central

Trembley, Janeen H.; Chen, Zhong; Unger, Gretchen; Slaton, Joel; Kren, Betsy T.; Van Waes, Carter; Ahmed, Khalil

2010-01-01

Protein kinase CK2, a protein serine/threonine kinase, plays a global role in activities related to cell growth, cell death and cell survival. CK2 has a large number of potential substrates localized in diverse locations in the cell including, e.g., NF-κB as an important downstream target of the kinase. In addition to its involvement in cell growth and proliferation it is also a potent suppressor of apoptosis, raising its key importance in cancer cell phenotype. CK2 interacts with diverse pathways which illustrates the breadth of its impact on the cellular machinery of both cell growth and cell death giving it the status of a “master regulator” in the cell. With respect to cancer, CK2 has been found to be dysregulated in all cancers examined demonstrating increased protein expression levels and nuclear localization in cancer cells compared with their normal counterparts. We originally proposed CK2 as a potentially important target for cancer therapy. Given the ubiquitous and essential for cell survival nature of the kinase, an important consideration would be to target it specifically in cancer cells while sparing normal cells. Towards that end, our design of a tenascin based sub-50 nm (i.e., less than 50 nm size) nanocapsule in which an anti-CK2 therapeutic agent can be packaged is highly promising because this formulation can specifically deliver the cargo intracellularly to the cancer cells in vivo. Thus, appropriate strategies to target CK2 especially by molecular approaches may lead to a highly feasible and effective approach to eradication of a given cancer. PMID:20533398

Low-cost and miniaturized 100-Gb/s (2 × 50 Gb/s) PAM-4 TO-packaged ROSA for data center networks.

PubMed

Kang, Sae-Kyoung; Huh, Joon Young; Lee, Jie Hyun; Lee, Joon Ki

2018-03-05

We design and implement a cost-effective and compact 100-Gb/s (2 × 50 Gb/s) PAM-4 receiver optical sub-assembly (ROSA) by using a TO-can package instead of an expensive box-type package. It consists of an optical demultiplexer, two PIN-PDs and a 2-channel linear transimpedance amplifier. The components are passively aligned and assembled using alignment marks engraved on each part. With a real-time PAM-4 DSP chip, we measured the back-to-back receiver sensitivities of the 100-Gb/s ROSA based on TO-56 to be less than -13.2 dBm for both channels at a bit error rate of 2.4e-4. The crosstalk penalty due to the adjacent channel interference was observed around 0.1 dB.

[Lentivirus-mediated shRNA silencing of LAMP2A inhibits the proliferation of multiple myeloma cells].

PubMed

Li, Lixuan; Li, Jia

2015-05-01

To study the effects of lentivirus-mediated short hairpin RNA (shRNA) silencing of lysosome-associated membrane protein type 2A (LAMP2A) expression on the proliferation of multiple myeloma cells. The constructed shRNA lentiviral vector was applied to infect human multiple myeloma cell line MM.1S, and stable expression cell line was obtained by puromycin screening. Western blotting was used to verify the inhibitory effect on LAMP2A protein expression. MTT assay was conducted to detect the effect of knocked-down LAMP2A on MM.1S cell proliferation, and the anti-tumor potency of suberoylanilide hydroxamic acid (SAHA) against the obtained MM.1S LAMP2A(shRNA) stable cell line. Lactate assay was performed to observe the impact of low LAMP2A expression on cell glycolysis. The stable cell line with low LAMP2A expression were obtained with the constructed human LAMP2A-shRNA lentiviral vector. Down-regulation of LAMP2A expression significantly inhibited MM.1S cell proliferation and enhanced the anti-tumor activity of SAHA. Interestingly, decreased LAMP2A expression also inhibited MM.1S cell lactic acid secretion. Down-regulation of LAMP2A expression could inhibit cell proliferation in multiple myeloma cells.

α-Lipoic acid inhibits human lung cancer cell proliferation through Grb2-mediated EGFR downregulation.

PubMed

Yang, Lan; Wen, Ya; Lv, Guoqing; Lin, Yuntao; Tang, Junlong; Lu, Jingxiao; Zhang, Manqiao; Liu, Wen; Sun, Xiaojuan

2017-12-09

Alpha lipoic acid (α -LA) is a naturally occurring antioxidant and metabolic enzyme co-factor. Recently, α -LA has been reported to inhibit the growth of various cancer cells, but the precise signaling pathways that mediate the effects of α -LA on non-small cell lung cancer (NSCLC) development remain unclear. The CCK-8 assay was used to assess cell proliferation in NSCLC cell lines after α -LA treatment. The expression of growth factor receptor-bound protein 2 (Grb2), cyclin-dependent kinase (CDK)-2, CDK4, CDK6, Cyclin D3, Cyclin E1, Ras, c-Raf, epidermal growth factor receptor (EGFR), ERK1/2 and activated EGFR and ERK1/2 was evaluated by western blotting. Grb2 levels were restored in α-LA-treated cells by transfection of a plasmid carrying Grb2 and were reduced in NSCLC cells via specific siRNA-mediated knockdown. α -LA dramatically decreased NSCLC cell proliferation by downregulating Grb2; in contrast, Grb2 overexpression significantly prevented α-LA-induced decrease in cell growth in vitro. Western blot analysis indicated that α-LA decreased the levels of phospho-EGFR, CDK2/4/6, Cyclins D3 and E1, which are associated with the inhibition of G1/S-phase transition. Additional experiments indicated that Grb2 inhibition partially abolished EGF-induced phospho-EGFR and phospho-ERK1/2 activity. In addition, α-LA exerted greater inhibitory effects than gefitinib on NSCLC cells by preventing EGF-induced EGFR activation. For the first time, these findings provide the first evidence that α-LA inhibits cell proliferation through Grb2 by suppressing EGFR phosphorylation and that MAPK/ERK is involved in this pathway. Copyright © 2017. Published by Elsevier Inc.

Extracellular ATP drives breast cancer cell migration and metastasis via S100A4 production by cancer cells and fibroblasts.

PubMed

Liu, Ying; Geng, Yue-Hang; Yang, Hui; Yang, Han; Zhou, Yan-Ting; Zhang, Hong-Quan; Tian, Xin-Xia; Fang, Wei-Gang

2018-05-04

Our previous work has demonstrated that extracellular ATP is an important pro-invasive factor, and in this study, we tapped into a possible mechanism involved. We discovered that ATP could upregulate both the intracellular expression and secretion of S100A4 in breast cancer cells and fibroblasts. Apart from stimulating breast cancer cell motility via intracellular S100A4, ATP enhanced the ability of breast cancer cells to transform fibroblasts into cancer-associated fibroblast (CAF)-like cells, which in turn secreted S100A4 to further promote cancer cell motility. Both apyrase and niclosamide treatments could inhibit metastasis of inoculated tumors to lung, liver and kidney in mice model, and CAFs from these treated tumors exhibited weakened migration-stimulating capacity for breast cancer cells. Collectively, our data indicate that extracellular ATP promotes the interactions between breast cancer cells and fibroblasts, which work collaboratively via production of S100A4 to exacerbate breast cancer metastasis. Copyright © 2018. Published by Elsevier B.V.

Porcine S100A8 and S100A9: molecular characterizations and crucial functions in response to Haemophilus parasuis infection

USDA-ARS?s Scientific Manuscript database

S100 calcium-binding protein A8 (S100A8) and S100 calcium-binding protein A9 (S100A9) are pivotal mediators of inflammatory and protective anti-infection responses for the mammalian host. In this study, we present the molecular cloning of porcine S100A8 (pS100A8) and porcine S100A9 (pS100A9). Both ...

Inhibition of cytochrome P450 2B4 by environmentally persistent free radical-containing particulate matter

PubMed Central

Reed, James R.; dela Cruz, Albert Leo N.; Lomnicki, Slawo M.; Backes, Wayne L.

2015-01-01

Combustion processes generate particulate matter (PM) that can affect human health. The presence of redox-active metals and aromatic hydrocarbons in the post-combustion regions results in the formation of air-stable, environmentally persistent free radicals (EPFRs) on entrained particles. Exposure to EPFRs has been shown to negatively influence pulmonary and cardiovascular functions. Cytochromes P450 (P450/CYP) are endoplasmic reticulum resident proteins that are responsible for the metabolism of foreign compounds. Previously, it was shown that model EPFRs, generated by exposure of silica containing 5% copper oxide (CuO-Si) to either dicholorobenzene (DCB230) or 2-monochlorophenol (MCP230) at ≥ 230°C, inhibited six forms of P450 in rat liver microsomes (Toxicol. Appl. Pharmacol. (2014) 277:200-209). In this study, the inhibition of P450 by MCP230 was examined in more detail by measuring its effect on the rate of metabolism of 7-ethoxy-4-trifluoromethylcoumarin (7EFC) and 7-benzyloxyresorufin (7BRF) by the purified, reconstituted CYP2B4 system. MCP230 inhibited the CYP2B4-mediated metabolism of 7EFC at least 10-fold more potently than non-EPFR controls (CuO-Si, silica, and silica generated from heating silica and MCP at 50°C, so that EPFRs were not formed (MCP50)). The inhibition by EPFRs was specific for the P450 and did not affect the ability of the redox partner, P450 reductase (CPR) from reducing cytochrome c. All of the PM inhibited CYP2B4-mediated metabolism noncompetitively with respect to substrate. When CYP2B4-mediated metabolism of 7EFC was measured as a function of the CPR concentration, the mechanism of inhibition was competitive. EPFRs likely inhibit CYP2B4-mediated substrate metabolism by physically disrupting the CPR•P450 complex. PMID:25817938

Protein Kinase CK2 Regulates Cytoskeletal Reorganization during Ionizing Radiation-Induced Senescence of Human Mesenchymal Stem Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Daojing; Jang, Deok-Jin

2009-08-21

Human mesenchymal stem cells (hMSC) are critical for tissue regeneration. How hMSC respond to genotoxic stresses and potentially contribute to aging and cancer remain underexplored. We demonstrated that ionizing radiation induced cellular senescence of hMSC over a period of 10 days, showing a critical transition between day 3 and day 6. This was confirmed by senescence-associated beta-galactosidase (SA-{beta}-gal) staining, protein expression profiles of key cell cycle regulators (retinoblastoma (Rb) protein, p53, p21{sup waf1/Cip1}, and p16{sup INK4A}), and senescence-associated secretory phenotypes (SASPs) (IL-8, IL-12, GRO, and MDC). We observed dramatic cytoskeletal reorganization of hMSC through reduction of myosin-10, redistribution of myosin-9,more » and secretion of profilin-1. Using a SILAC-based phosphoproteomics method, we detected significant reduction of myosin-9 phosphorylation at Ser1943, coinciding with its redistribution. Importantly, through treatment with cell permeable inhibitors (4,5,6,7-tetrabromo-1H-benzotriazole (TBB) and 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole (DMAT)), and gene knockdown using RNA interference, we identified CK2, a kinase responsible for myosin-9 phosphorylation at Ser1943, as a key factor contributing to the radiation-induced senescence of hMSC. We showed that individual knockdown of CK2 catalytic subunits CK2{alpha} and CK2{alpha}{prime} induced hMSC senescence. However, only knockdown of CK2{alpha} resulted in morphological phenotypes resembling those of radiation-induced senescence. These results suggest that CK2{alpha} and CK2{alpha}{prime} play differential roles in hMSC senescence progression, and their relative expression might represent a novel regulatory mechanism for CK2 activity.« less

The structure of Ca2+-loaded S100A2 at 1.3-Å resolution.

PubMed

Koch, Michael; Fritz, Günter

2012-05-01

S100A2 is an EF-hand calcium ion (Ca(2+))-binding protein that activates the tumour suppressor p53. In order to understand the molecular mechanisms underlying the Ca(2+) -induced activation of S100A2, the structure of Ca(2+)-bound S100A2 was determined at 1.3 Å resolution by X-ray crystallography. The structure was compared with Ca(2+) -free S100A2 and with other S100 proteins. Binding of Ca(2+) to S100A2 induces small structural changes in the N-terminal EF-hand, but a large conformational change in the C-terminal EF-hand, reorienting helix III by approximately 90°. This movement is accompanied by the exposure of a hydrophobic cavity between helix III and helix IV that represents the target protein interaction site. This molecular reorganization is associated with the breaking and new formation of intramolecular hydrophobic contacts. The target binding site exhibits unique features; in particular, the hydrophobic cavity is larger than in other Ca(2+)-loaded S100 proteins. The structural data underline that the shape and size of the hydrophobic cavity are major determinants for target specificity of S100 proteins and suggest that the binding mode for S100A2 is different from that of other p53-interacting S100 proteins. Database Structural data are available in the Protein Data Bank database under the accession number 4DUQ © 2012 The Authors Journal compilation © 2012 FEBS.

Towards Binding Mechanism of Cu2+ on Creatine Kinase from Pelodiscus sinensis: Molecular Dynamics Simulation Integrating Inhibition Kinetics Study.

PubMed

Cai, Yan; Lee, Jinhyuk; Wang, Wei; Park, Yong-Doo; Qian, Guo-Ying

2017-01-01

Cu2+ is well known to play important roles in living organisms having bifacial distinction: essential microelement that is necessary for a wide range of metabolic processes but hyper-accumulation of Cu2+ can be toxic. The physiological function of Cu2+ in ectothermic animals such as Pelodiscus sinensis (Chinese soft-shelled turtle) has not been elucidated. In this study, we elucidated effect of Cu2+ on the energy producing metabolic enzyme creatine kinase (CK), which might directly affect energy metabolism and homeostasis of P. sinensis. We first conducted molecular dynamics (MD) simulations between P-CK and Cu2+ and conducted the inactivation kinetics including spectrofluorimetry study. MD simulation showed that Cu2+ blocked the binding site of the ATP cofactor, indicating that Cu2+ could directly inactivate P-CK. We prepared the muscle type of CK (P-CK) and confirmed that Cu2+ conspicuously inactivated the activity of P-CK (IC50 = 24.3 μM) and exhibited non-competitive inhibition manner with creatine and ATP in a first-order kinetic process. This result was well matched to the MD simulation results that Cu2+-induced non-competitive inactivation of P-CK. The spectrofluorimetry study revealed that Cu2+ induced tertiary structure changes in PCK accompanying with the exposure of hydrophobic surfaces. Interestingly, the addition of osmolytes (glycine, proline, and liquaemin) effectively restored activity of the Cu2+-inactivated P-CK. Our study illustrates the Cu2+-mediated unfolding of P-CK with disruption of the enzymatic function and the protective restoration role of osmolytes on P-CK inactivation. This study provides information of interest on P-CK as a metabolic enzyme of ectothermic animal in response to Cu2+ binding. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Gambogic acid inhibits multiple myeloma mediated osteoclastogenesis through suppression of chemokine receptor CXCR4 signaling pathways.

PubMed

Pandey, Manoj K; Kale, Vijay P; Song, Chunhua; Sung, Shen-shu; Sharma, Arun K; Talamo, Giampaolo; Dovat, Sinisa; Amin, Shantu G

2014-10-01

Bone disease, characterized by the presence of lytic lesions and osteoporosis is the hallmark of multiple myeloma (MM). Stromal cell-derived factor 1α (SDF-1α) and its receptor, CXC chemokine receptor 4 (CXCR4), has been implicated as a regulator of bone resorption, suggesting that agents that can suppress SDF1α/CXCR4 signaling might inhibit osteoclastogenesis, a process closely linked to bone resorption. We, therefore, investigated whether gambogic acid (GA), a xanthone, could inhibit CXCR4 signaling and suppress osteoclastogenesis induced by MM cells. Through docking studies we predicted that GA directly interacts with CXCR4. This xanthone down-regulates the expression of CXCR4 on MM cells in a dose- and time-dependent manner. The down-regulation of CXCR4 was not due to proteolytic degradation, but rather GA suppresses CXCR4 mRNA expression by inhibiting nuclear factor-kappa B (NF-κB) DNA binding. This was further confirmed by quantitative chromatin immunoprecipitation assay, as GA inhibits p65 binding at the CXCR4 promoter. GA suppressed SDF-1α-induced chemotaxis of MM cells and downstream signaling of CXCR4 by inhibiting phosphorylation of Akt, p38, and Erk1/2 in MM cells. GA abrogated the RANKL-induced differentiation of macrophages to osteoclasts in a dose- and time-dependent manner. In addition, we found that MM cells induced differentiation of macrophages to osteoclasts, and that GA suppressed this process. Importantly, suppression of osteoclastogenesis by GA was mediated through IL-6 inhibition. Overall, our results show that GA is a novel inhibitor of CXCR4 expression and has a strong potential to suppress osteoclastogenesis mediated by MM cells. Published by Elsevier Inc.

Apigenin inhibits proliferation and induces apoptosis in human multiple myeloma cells through targeting the trinity of CK2, Cdc37 and Hsp90

PubMed Central

2011-01-01

Background Multiple myeloma (MM) is a B-cell malignancy that is largely incurable and is characterized by the accumulation of malignant plasma cells in the bone marrow. Apigenin, a common flavonoid, has been reported to suppress proliferation in a wide variety of solid tumors and hematological cancers; however its mechanism is not well understood and its effect on MM cells has not been determined. Results In this study, we investigated the effects of apigenin on MM cell lines and on primary MM cells. Cell viability assays demonstrated that apigenin exhibited cytotoxicity against both MM cell lines and primary MM cells but not against normal peripheral blood mononuclear cells. Together, kinase assays, immunoprecipitation and western blot analysis showed that apigenin inhibited CK2 kinase activity, decreased phosphorylation of Cdc37, disassociated the Hsp90/Cdc37/client complex and induced the degradation of multiple kinase clients, including RIP1, Src, Raf-1, Cdk4 and AKT. By depleting these kinases, apigenin suppressed both constitutive and inducible activation of STAT3, ERK, AKT and NF-κB. The treatment also downregulated the expression of the antiapoptotic proteins Mcl-1, Bcl-2, Bcl-xL, XIAP and Survivin, which ultimately induced apoptosis in MM cells. In addition, apigenin had a greater effects in depleting Hsp90 clients when used in combination with the Hsp90 inhibitor geldanamycin and the histone deacetylase inhibitor vorinostat. Conclusions Our results suggest that the primary mechanisms by which apigenin kill MM cells is by targeting the trinity of CK2-Cdc37-Hsp90, and this observation reveals the therapeutic potential of apigenin in treating multiple myeloma. PMID:21871133

[(35)S]-GTPgammaS autoradiography reveals alpha(2) adrenoceptor-mediated G-protein activation in amygdala and lateral septum.

PubMed

Newman-Tancredi, A; Chaput, C; Touzard, M; Millan, M J

2000-04-03

alpha(2)-adrenoceptor-mediated G-protein activation was examined by [(35)S]-GTPgammaS autoradiography. In alpha(2)-adrenoceptor-rich regions (amygdala, lateral septum), noradrenaline stimulated [(35)S]-GTPgammaS binding. These actions were abolished by the selective alpha(2) antagonist, atipamezole. Conversely, in caudate nucleus, which expresses few alpha(2) receptors, noradrenaline-induced stimulation was not inhibited by atipamezole, suggesting that it is not mediated by alpha(2)-adrenoceptors.

A novel O2-sensing mechanism in rat glossopharyngeal neurones mediated by a halothane-inhibitable background K+ conductance.

PubMed

Campanucci, Verónica A; Fearon, Ian M; Nurse, Colin A

2003-05-01

Modulation of K+ channels by hypoxia is a common O2-sensing mechanism in specialised cells. More recently, acid-sensitive TASK-like background K+ channels, which play a key role in setting the resting membrane potential, have been implicated in O2-sensing in certain cell types. Here, we report a novel O2 sensitivity mediated by a weakly pH-sensitive background K+ conductance in nitric oxide synthase (NOS)-positive neurones of the glossopharyngeal nerve (GPN). This conductance was insensitive to 30 mM TEA, 5 mM 4-aminopyridine (4-AP) and 200 microM Cd2+, but was reversibly inhibited by hypoxia (O2 tension (PO2) = 15 mmHg), 2-5 mM halothane, 10 mM barium and 1 mM quinidine. Notably, the presence of halothane occluded the inhibitory effect of hypoxia. Under current clamp, these agents depolarised GPN neurones. In contrast, arachidonic acid (5-10 microM) caused membrane hyperpolarisation and potentiation of the background K+ current. This pharmacological profile suggests the O2-sensitive conductance in GPN neurones is mediated by a class of background K+ channels different from the TASK family; it appears more closely related to the THIK (tandem pore domain halothane-inhibited K+) subfamily, or may represent a new member of the background K+ family. Since GPN neurones are thought to provide NO-mediated efferent inhibition of the carotid body (CB), these channels may contribute to the regulation of breathing during hypoxia via negative feedback control of CB function, as well as to the inhibitory effect of volatile anaesthetics (e.g. halothane) on respiration.

Ibrutinib inhibits SDF1/CXCR4 mediated migration in AML

PubMed Central

Zaitseva, Lyubov; Murray, Megan Y.; Shafat, Manar S.; Lawes, Matthew J.; MacEwan, David J.; Bowles, Kristian M.; Rushworth, Stuart A.

2014-01-01

Pharmacological targeting of BTK using ibrutinib has recently shown encouraging clinical activity in a range of lymphoid malignancies. Recently we reported that ibrutinib inhibits human acute myeloid leukemia (AML) blast proliferation and leukemic cell adhesion to the surrounding bone marrow stroma cells. Here we report that in human AML ibrutinib, in addition, functions to inhibit SDF1/CXCR4-mediated AML migration at concentrations achievable in vivo. It has previously been shown that SDF1/CXCR4-induced migration is dependent on activation of downstream BTK in chronic lymphocytic leukaemia (CLL) and multiple myeloma. Here we show that SDF-1 induces BTK phosphorylation and downstream MAPK signalling in primary AML blast. Furthermore, we show that ibrutinib can inhibit SDF1-induced AKT and MAPK activation. These results reported here provide a molecular mechanistic rationale for clinically evaluating BTK inhibition in AML patients and suggests that in some AML patients the blasts count may initially rise in response to ibrutinib therapy, analgous to similar clinical observations in CLL. PMID:25294819

Emerging roles of protein kinase CK2 in abscisic acid signaling.

PubMed

Vilela, Belmiro; Pagès, Montserrat; Riera, Marta

2015-01-01

The phytohormone abscisic acid (ABA) regulates many aspects of plant growth and development as well as responses to multiple stresses. Post-translational modifications such as phosphorylation or ubiquitination have pivotal roles in the regulation of ABA signaling. In addition to the positive regulator sucrose non-fermenting-1 related protein kinase 2 (SnRK2), the relevance of the role of other protein kinases, such as CK2, has been recently highlighted. We have recently established that CK2 phosphorylates the maize ortholog of open stomata 1 OST1, ZmOST1, suggesting a role of CK2 phosphorylation in the control of ZmOST1 protein degradation (Vilela et al., 2015). CK2 is a pleiotropic enzyme involved in multiple developmental and stress-responsive pathways. This review summarizes recent advances that taken together suggest a prominent role of protein kinase CK2 in ABA signaling and related processes.

Neutrophil-derived S100 calcium-binding proteins A8/A9 promote reticulated thrombocytosis and atherogenesis in diabetes

PubMed Central

Kraakman, Michael J.; Lee, Man K.S.; Al-Sharea, Annas; Dragoljevic, Dragana; Barrett, Tessa J.; Montenont, Emilie; Basu, Debapriya; Heywood, Sarah; Kammoun, Helene L.; Flynn, Michelle; Whillas, Alexandra; Hanssen, Nordin M.J.; Febbraio, Mark A.; Westein, Erik; Chin-Dusting, Jaye; Cooper, Mark E.; Berger, Jeffrey S.; Goldberg, Ira J.; Nagareddy, Prabhakara R.; Murphy, Andrew J.

2017-01-01

Platelets play a critical role in atherogenesis and thrombosis-mediated myocardial ischemia, processes that are accelerated in diabetes. Whether hyperglycemia promotes platelet production and whether enhanced platelet production contributes to enhanced atherothrombosis remains unknown. Here we found that in response to hyperglycemia, neutrophil-derived S100 calcium-binding proteins A8/A9 (S100A8/A9) interact with the receptor for advanced glycation end products (RAGE) on hepatic Kupffer cells, resulting in increased production of IL-6, a pleiotropic cytokine that is implicated in inflammatory thrombocytosis. IL-6 acts on hepatocytes to enhance the production of thrombopoietin, which in turn interacts with its cognate receptor c-MPL on megakaryocytes and bone marrow progenitor cells to promote their expansion and proliferation, resulting in reticulated thrombocytosis. Lowering blood glucose using a sodium-glucose cotransporter 2 inhibitor (dapagliflozin), depleting neutrophils or Kupffer cells, or inhibiting S100A8/A9 binding to RAGE (using paquinimod), all reduced diabetes-induced thrombocytosis. Inhibiting S100A8/A9 also decreased atherogenesis in diabetic mice. Finally, we found that patients with type 2 diabetes have reticulated thrombocytosis that correlates with glycated hemoglobin as well as increased plasma S100A8/A9 levels. These studies provide insights into the mechanisms that regulate platelet production and may aid in the development of strategies to improve on current antiplatelet therapies and to reduce cardiovascular disease risk in diabetes. PMID:28504650

Biophysical characterization of the structural change of Nopp140, an intrinsically disordered protein, in the interaction with CK2α

DOE Office of Scientific and Technical Information (OSTI.GOV)

Na, Jung-Hyun; Biomedical Research Institute, Korea Institute of Science and Technology, Seoul 02792; Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760

2016-08-19

Nucleolar phosphoprotein 140 (Nopp140) is a nucleolar protein, more than 80% of which is disordered. Previous studies have shown that the C-terminal region of Nopp140 (residues 568–596) interacts with protein kinase CK2α, and inhibits the catalytic activity of CK2. Although the region of Nopp140 responsible for the interaction with CK2α was identified, the structural features and the effect of this interaction on the structure of Nopp140 have not been defined due to the difficulty of structural characterization of disordered protein. In this study, the disordered feature of Nopp140 and the effect of CK2α on the structure of Nopp140 were examinedmore » using single-molecule fluorescence resonance energy transfer (smFRET) and electron paramagnetic resonance (EPR). The interaction with CK2α was increased conformational rigidity of the CK2α-interacting region of Nopp140 (Nopp140C), suggesting that the disordered and flexible conformation of Nopp140C became more rigid conformation as it binds to CK2α. In addition, site specific spin labeling and EPR analysis confirmed that the residues 574–589 of Nopp140 are critical for binding to CK2α. Similar technical approaches can be applied to analyze the conformational changes in other IDPs during their interactions with binding partners. - Highlights: • Nopp140 is intrinsically disordered protein (IDP). • Conformation of Nopp140 became more rigid conformation due to interaction with CK2α. • smFRET and EPR could be applied to analyze the structural changes of IDPs.« less

Targeting Protein Kinase CK2: Evaluating CX-4945 Potential for GL261 Glioblastoma Therapy in Immunocompetent Mice

PubMed Central

Ferrer-Font, Laura; Villamañan, Lucia; Arias-Ramos, Nuria; Vilardell, Jordi; Plana, Maria; Ruzzene, Maria; Pinna, Lorenzo A.; Itarte, Emilio; Arús, Carles; Candiota, Ana Paula

2017-01-01

Glioblastoma (GBM) causes poor survival in patients even with aggressive treatment. Temozolomide (TMZ) is the standard chemotherapeutic choice for GBM treatment but resistance always ensues. Protein kinase CK2 (CK2) contributes to tumour development and proliferation in cancer, and it is overexpressed in human GBM. Accordingly, targeting CK2 in GBM may benefit patients. Our goal has been to evaluate whether CK2 inhibitors (iCK2s) could increase survival in an immunocompetent preclinical GBM model. Cultured GL261 cells were treated with different iCK2s including CX-4945, and target effects evaluated in vitro. CX-4945 was found to decrease CK2 activity and Akt(S129) phosphorylation in GL261 cells. Longitudinal in vivo studies with CX-4945 alone or in combination with TMZ were performed in tumour-bearing mice. Increase in survival (p < 0.05) was found with combined CX-4945 and TMZ metronomic treatment (54.7 ± 11.9 days, n = 6) when compared to individual metronomic treatments (CX-4945: 24.5 ± 2.0 and TMZ: 38.7 ± 2.7, n = 6) and controls (22.5 ± 1.2, n = 6). Despite this, CX-4945 did not improve mice outcome when administered on every/alternate days, either alone or in combination with 3-cycle TMZ. The highest survival rate was obtained with the metronomic combined TMZ+CX-4945 every 6 days, pointing to the participation of the immune system or other ancillary mechanism in therapy response. PMID:28208677

Involvement of S100A8/A9-TLR4-NLRP3 Inflammasome Pathway in Contrast-Induced Acute Kidney Injury.

PubMed

Tan, Xuexian; Zheng, Xiaohe; Huang, Zena; Lin, Jiaqiong; Xie, Chuli; Lin, Yan

2017-01-01

Contrast-induced acute kidney injury (CIAKI) is a common cause of hospital-acquired acute kidney injury (AKI). S100A8/A9-TLR4-NLRP3 inflammasome pathway triggers inflammation, apoptosis and tissue injury in several AKI models. Nevertheless, the underlying mechanism of S100A8/A9-TLR4-NLRP3 inflammasome pathway in CIKAI is not clear. We aimed to investigate the possible role of S100A8/A9-TLR4-NLRP3 inflammasome in the pathophysiology of CIAKI. We treated male rats and NRK-52E cells by iopromide to establish in vivo and in vitro models of CIAKI. We collected serum and urine samples to detect renal function. We obtained kidney tissue for histological analysis and detection of protein concentration. We used inhibitor of TLR4 and NLRP3-siRNA to further testify their role in CIAKI in NRK-52E cells. Iopromide caused elevation of SCr, BUN and NGAL level, decrease of endogenous creatinine clearance, morphological injury and tubular apoptosis, enhanced IL-1β and IL-18 expression, and increased expression of S100A8/A9, TLR4 and NLRP3 inflammsome. In NRK-52E cells, iopromide caused enhanced apoptotic rates and ROS generation, which could be ameliorated by inhibitor of TLR4 and NLRP3-siRNA. Moreover, inhibition of TLR4 dampened NLRP3 expression. S100A8/A9-TLR4-NLRP3 inflammasome pathway represented a key mechanism of CI-AKI, which provided a potential therapeutic target. © 2017 The Author(s). Published by S. Karger AG, Basel.

Including Delbrück scattering in GEANT4

NASA Astrophysics Data System (ADS)

Omer, Mohamed; Hajima, Ryoichi

2017-08-01

Elastic scattering of γ-rays is a significant interaction among γ-ray interactions with matter. Therefore, the planning of experiments involving measurements of γ-rays using Monte Carlo simulations usually includes elastic scattering. However, current simulation tools do not provide a complete picture of elastic scattering. The majority of these tools assume Rayleigh scattering is the primary contributor to elastic scattering and neglect other elastic scattering processes, such as nuclear Thomson and Delbrück scattering. Here, we develop a tabulation-based method to simulate elastic scattering in one of the most common open-source Monte Carlo simulation toolkits, GEANT4. We collectively include three processes, Rayleigh scattering, nuclear Thomson scattering, and Delbrück scattering. Our simulation more appropriately uses differential cross sections based on the second-order scattering matrix instead of current data, which are based on the form factor approximation. Moreover, the superposition of these processes is carefully taken into account emphasizing the complex nature of the scattering amplitudes. The simulation covers an energy range of 0.01 MeV ≤ E ≤ 3 MeV and all elements with atomic numbers of 1 ≤ Z ≤ 99. In addition, we validated our simulation by comparing the differential cross sections measured in earlier experiments with those extracted from the simulations. We find that the simulations are in good agreement with the experimental measurements. Differences between the experiments and the simulations are 21% for uranium, 24% for lead, 3% for tantalum, and 8% for cerium at 2.754 MeV. Coulomb corrections to the Delbrück amplitudes may account for the relatively large differences that appear at higher Z values.

Crystal structure of human S100A8 in complex with zinc and calcium.

PubMed

Lin, Haili; Andersen, Gregers Rom; Yatime, Laure

2016-06-01

S100 proteins are a large family of calcium binding proteins present only in vertebrates. They function intra- and extracellularly both as regulators of homeostatic processes and as potent effectors during inflammation. Among these, S100A8 and S100A9 are two major constituents of neutrophils that can assemble into homodimers, heterodimers and higher oligomeric species, including fibrillary structures found in the ageing prostate. Each of these forms assumes specific functions and their formation is dependent on divalent cations, notably calcium and zinc. In particular, zinc appears as a major regulator of S100 protein function in a disease context. Despite this central role, no structural information on how zinc bind to S100A8/S100A9 and regulates their quaternary structure is yet available. Here we report two crystallographic structures of calcium and zinc-loaded human S100A8. S100A8 binds two zinc ions per homodimer, through two symmetrical, all-His tetracoordination sites, revealing a classical His-Zn binding mode for the protein. Furthermore, the presence of a (Zn)2-cacodylate complex in our second crystal form induces ligand swapping within the canonical His4 zinc binding motif, thereby creating two new Zn-sites, one of which involves residues from symmetry-related molecules. Finally, we describe the calcium-induced S100A8 tetramer and reveal how zinc stabilizes this tetramer by tightening the dimer-dimer interface. Our structures of Zn(2+)/Ca(2+)-bound hS100A8 demonstrate that S100A8 is a genuine His-Zn S100 protein. Furthermore, they show how zinc stabilizes S100A8 tetramerization and potentially mediates the formation of novel interdimer interactions. We propose that these zinc-mediated interactions may serve as a basis for the generation of larger oligomers in vivo.

Second-generation CK2α inhibitors targeting the αD pocket† †Electronic supplementary information (ESI) available: All experimental details, crystallographic data collection and refinement statistics, details of chemical synthesis, additional figures and tables. See DOI: 10.1039/c7sc05122k

PubMed Central

Iegre, Jessica; Brear, Paul; De Fusco, Claudia; Yoshida, Masao; Mitchell, Sophie L.; Rossmann, Maxim; Carro, Laura; Sore, Hannah F.

2018-01-01

CK2 is a critical cell cycle regulator that also promotes various anti-apoptotic mechanisms. Development of ATP-non-competitive inhibitors of CK2 is a very attractive strategy considering that the ATP binding site is highly conserved among other kinases. We have previously utilised a pocket outside the active site to develop a novel CK2 inhibitor, CAM4066. Whilst CAM4066 bound to this new pocket it was also interacting with the ATP site: herein, we describe an example of a CK2α inhibitor that binds completely outside the active site. This second generation αD-site binding inhibitor, compound CAM4712 (IC50 = 7 μM, GI50 = 10.0 ± 3.6 μM), has numerous advantages over the previously reported CAM4066, including a reduction in the number of rotatable bonds, the absence of amide groups susceptible to the action of proteases and improved cellular permeability. Unlike with CAM4066, there was no need to facilitate cellular uptake by making a prodrug. Moreover, CAM4712 displayed no drop off between its ability to inhibit the kinase in vitro (IC50) and the ability to inhibit cell proliferation (GI50). PMID:29732088

The kinase domain of CK1 enzymes contains the localization cue essential for compartmentalized signaling at the spindle pole.

PubMed

Elmore, Zachary C; Guillen, Rodrigo X; Gould, Kathleen L

2018-05-09

CK1 protein kinases contribute to multiple biological processes, but how they are tailored to function in compartmentalized signaling events is largely unknown. Hhp1 and Hhp2 (Hhp1/2) are the soluble CK1 family members in Schizosaccharomyces pombe. One of their functions is to inhibit the septation initiation network (SIN) during a mitotic checkpoint arrest. The SIN is assembled by Sid4 at spindle pole bodies (SPBs), and though Hhp1/2 co-localize there, it is not known how they are targeted there nor if their SPB localization is required for SIN inhibition. Here, we establish that Hhp1/2 localize throughout the cell cycle to SPBs, as well as to the nucleus, cell tips, and division site. We find that their catalytic domains but not enzymatic function are used for SPB targeting and that this targeting strategy is conserved in human CK1δ/ε localization to centrosomes. Further, we pinpoint amino acids in the Hhp1 catalytic domain required for SPB interaction; mutation of these residues disrupts Hhp1 association with the core SPB protein Ppc89, and the inhibition of cytokinesis in the setting of spindle stress. Taken together, we have defined a molecular mechanism used by CK1 enzymes to target to a specific cellular locale for compartmentalized signaling.

Functional Characterization of S100A8 and S100A9 in Altering Monolayer Permeability of Human Umbilical Endothelial Cells

PubMed Central

Wang, Liqun; Luo, Haihua; Chen, Xiaohuan; Jiang, Yong; Huang, Qiaobing

2014-01-01

S100A8, S100A9 and S100A8/A9 complexes have been known as important endogenous damage-associated molecular pattern (DAMP) proteins. But the pathophysiological roles of S100A8, S100A9 and S100A8/A9 in cardiovascular diseases are incompletely explained. In this present study, the effects of homo S100A8, S100A9 and their hetero-complex S100A8/A9 on endothelial barrier function were tested respectively in cultured human umbilical venous endothelial cells (HUVECs). The involvement of TLR4 and RAGE were observed by using inhibitor of TLR4 and blocking antibody of RAGE. The clarification of different MAPK subtypes in S100A8/A9-induced endothelial response was implemented by using specific inhibitors. The calcium-dependency was detected in the absence of Ca2+ or in the presence of gradient-dose Ca2+. The results showed that S100A8, S100A9 and S100A8/A9 could induce F-actin and ZO-1 disorganization in HUVECs and evoked the increases of HUVEC monolayer permeability in a dose- and time-dependent manner. The effects of S100A8, S100A9 and S100A8/A9 on endothelial barrier function depended on the activation of p38 and ERK1/2 signal pathways through receptors TLR4 and RAGE. Most importantly, we revealed the preference of S100A8 on TLR4 and S100A9 on RAGE in HUVECs. The results also showed the calcium dependency in S100A8- and S100A9-evoked endothelial response, indicating that calcium dependency on formation of S100A8 or A9 dimmers might be the prerequisite for this endothelial functional alteration. PMID:24595267

PTEN-mediated ERK1/2 inhibition and paradoxical cellular proliferation following Pnck overexpression

PubMed Central

Deb, Tushar B; Barndt, Robert J; Zuo, Annie H; Sengupta, Surojeet; Coticchia, Christine M; Johnson, Michael D

2014-01-01

Pregnancy upregulated non-ubiquitous calmodulin kinase (Pnck), a novel calmodulin kinase, is significantly overexpressed in breast and renal cancers. We present evidence that at high cell density, overexpression of Pnck in HEK 293 cells inhibits serum-induced extracellular signal-regulated kinase (ERK1/ERK2) activation. ERK1/2 inhibition is calcium-dependent and Pnck kinase activity is required for ERK1/2 inhibition, since expression of a kinase-dead (K44A) and a catalytic loop phosphorylation mutant (T171A) Pnck protein is unable to inhibit ERK 1/2 activity. Ras is constitutively active at high cell density, and Pnck does not alter Ras activation, suggesting that Pnck inhibition of ERK1/2 activity is independent of Ras activity. Pnck inhibition of serum-induced ERK1/2 activity is lost in cells in which phosphatase and tensin homolog (PTEN) is suppressed, suggesting that Pnck inhibition of ERK1/2 activity is mediated by PTEN. Overexpression of protein phosphatase-active but lipid phosphatase-dead PTEN protein inhibits ERK1/2 activity in control cells and enhances Pnck-mediated ERK1/2 inhibition, suggesting that Pnck increases availability of protein phosphatase active PTEN for ERK1/2 inhibition. Pnck is a stress-responsive kinase; however, serum-induced p38 MAP kinase activity is also downregulated by Pnck in a Pnck kinase- and PTEN-dependent manner, similar to ERK1/2 inhibition. Pnck overexpression increases proliferation, which is inhibited by PTEN knockdown, implying that PTEN acts as a paradoxical promoter of proliferation in ERK1/2 and p38 MAP kinase phosphorylation-inhibited, Pnck-overexpressing cells. Overall, these data reveal a novel function of Pnck in the regulation of ERK1/2 and p38 MAP kinase activity and cell proliferation, which is mediated by paradoxical PTEN functions. The possible biological implications of these data are discussed. PMID:24552815

Purification and characterization of a fibrinolytic enzyme produced from Bacillus sp. strain CK 11-4 screened from Chungkook-Jang.

PubMed Central

Kim, W; Choi, K; Kim, Y; Park, H; Choi, J; Lee, Y; Oh, H; Kwon, I; Lee, S

1996-01-01

Bacillus sp. strain CK 11-4, which produces a strongly fibrinolytic enzyme, was screened from Chungkook-Jang, a traditional Korean fermented-soybean sauce. The fibrinolytic enzyme (CK) was purified from supernatant of Bacillus sp. strain CK 11-4 culture broth and showed thermophilic, hydrophilic, and strong fibrinolytic activity. The optimum temperature and pH were 70 degrees C and 10.5, respectively, and the molecular weight was 28,200 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The first 14 amino acids of the N-terminal sequence of CK are Ala-Gin-Thr-Val-Pro-Tyr-Gly-Ile-Pro-Leu-Ile-Lys-Ala-Asp. This sequence is identical to that of subtilisin Carlsberg and different from that of nattokinase, but CK showed a level of fibrinolytic activity that was about eight times higher than that of subtilisin Carlsberg. The amidolytic activity of CK increased about twofold at the initial state of the reaction when CK enzyme was added to a mixture of plasminogen and substrate (H-D-Val-Leu-Lys-pNA). A similar result was also obtained from fibrin plate analysis. PMID:8779587

α2 Adrenergic receptor-mediated inhibition of thermogenesis.

PubMed

Madden, Christopher J; Tupone, Domenico; Cano, Georgina; Morrison, Shaun F

2013-01-30

α2 adrenergic receptor (α2-AR) agonists have been used as antihypertensive agents, in the management of drug withdrawal, and as sedative analgesics. Since α2-AR agonists also influence the regulation of body temperature, we explored their potential as antipyretic agents. This study delineates the central neural substrate for the inhibition of rat brown adipose tissue (BAT) and shivering thermogenesis by α2-AR agonists. Nanoinjection of the α2-AR agonist clonidine (1.2 nmol) into the rostral raphe pallidus area (rRPa) inhibited BAT sympathetic nerve activity (SNA) and BAT thermogenesis. Subsequent nanoinjection of the α2-AR antagonist idazoxan (6 nmol) into the rRPa reversed the clonidine-evoked inhibition of BAT SNA and BAT thermogenesis. Systemic administration of the α2-AR agonists dexmedetomidine (25 μg/kg, i.v.) and clonidine (100 μg/kg, i.v.) inhibited shivering EMGs, BAT SNA, and BAT thermogenesis, effects that were reversed by nanoinjection of idazoxan (6 nmol) into the rRPa. Dexmedetomidine (100 μg/kg, i.p.) prevented and reversed lipopolysaccharide-evoked (10 μg/kg, i.p.) thermogenesis in free-behaving rats. Cholera toxin subunit b retrograde tracing from rRPa and pseudorabies virus transynaptic retrograde tracing from BAT combined with immunohistochemistry for catecholaminergic biosynthetic enzymes revealed the ventrolateral medulla as the source of catecholaminergic input to the rRPa and demonstrated that these catecholaminergic neurons are synaptically connected to BAT. Photostimulation of ventrolateral medulla neurons expressing the PRSx8-ChR2-mCherry lentiviral vector inhibited BAT SNA via activation of α2-ARs in the rRPa. These results indicate a potent inhibition of BAT and shivering thermogenesis by α2-AR activation in the rRPa, and suggest a therapeutic potential of α2-AR agonists for reducing potentially lethal elevations in body temperature during excessive fever.

Alpha-2 adrenergic receptor-mediated inhibition of thermogenesis

PubMed Central

Madden, Christopher J.; Tupone, Domenico; Cano, Georgina; Morrison, Shaun F.

2013-01-01

Alpha2-adrenergic receptor (α2-AR) agonists have been use as anti-hypertensive agents, in the management of drug withdrawal, and as sedative analgesics. Since α2-AR agonists also influence the regulation of body temperature, we explored their potential as antipyretic agents. This study delineates the central neural substrate for the inhibition of rat brown adipose tissue (BAT) and shivering thermogenesis by α2-AR agonists. Nanoinjection of the α2-AR agonist, clonidine (1.2 nmol), into the rostral raphe pallidus (rRPa) inhibited BAT sympathetic nerve activity (SNA) and BAT thermogenesis. Subsequent nanoinjection of the α2-AR antagonist, idazoxan (6nmol) into the rRPa reversed the clonidine-evoked inhibition of BAT SNA and BAT thermogenesis. Systemic administration of the α2-AR agonists, dexmedetomidine (25ug/kg, iv) or clonidine (100ug/kg, iv) inhibited shivering EMGs, BAT SNA and BAT thermogenesis effects that were reversed by nanoinjection of idazoxan (6nmol) into the rRPa. Dexmedetomidine (100µg/kg, ip) prevented and reversed lipopolysaccharide (10µg/kg ip)-evoked thermogenesis in free-behaving rats. Cholera toxin subunit b retrograde tracing from rRPa and pseudorabies virus transynaptic retrograde tracing from BAT combined with immunohistochemistry for catecholaminergic biosynthetic enzymes revealed the ventrolateral medulla as the source of catecholaminergic input to the rRPa and demonstrated that these catecholaminergic neurons are synaptically connected to BAT. Photostimulation of VLM neurons expressing of the PRSx8-ChR2-mCherry lentiviral vector inhibited BAT SNA via activation of α2-ARs in the rRPa. These results indicate a potent inhibition of BAT and shivering thermogenesis by α2-AR activation in the rRPa, and suggest a therapeutic potential of α2-AR agonists for reducing potentially-lethal elevations in body temperature during excessive fever. PMID:23365239

Rapamycin inhibits CaCl2-induced thoracic aortic aneurysm formation in rats through mTOR-mediated suppression of proinflammatory mediators.

PubMed

Cao, Jiumei; Wu, Qihong; Geng, Liang; Chen, Xiaonan; Shen, Weifeng; Wu, Fang; Chen, Ying

2017-08-01

The aim of the present study was to investigate the effect of the mammalian target of rapamycin (mTOR) signaling pathway on thoracic aortic aneurysm (TAA) development. The study used a calcium chloride (CaCl2)‑induced rat TAA model to explore the potential role of mTOR signaling pathway in the disease development. Adult male Sprague‑Dawley rats underwent the periarterial exposure of thoracic aorta to either 0.5 M CaCl2 or normal saline, and a subgroup of CaCl2‑treated rats received rapamycin 1 day prior to surgery. Without pre‑administering rapamycin, significantly enhanced phosphorylation of mTOR and expression of proinflammatory cytokines [i.e., tumor necrosis factor α (TNF‑α), interleukin 6 (IL‑6), and interleukin (IL)‑1β] were observed in the CaCl2‑treated aortic segments 2 days post‑treatment compared with the NaCl‑treated segments. At 2 weeks post‑treatment, hematoxylin and eosin and Verhoeff‑Van Gieson staining revealed aneurysmal alteration and disappearance of normal wavy elastic structures in the aortic segments exposed to CaCl2. In contrast, the CaCl2‑induced TAA formation was inhibited by pre‑administering rapamycin to CaCl2‑treated rats, which demonstrated attenuated mTOR phosphorylation and downregulation of the proinflammatory mediators (i.e., TNF‑α, IL‑6, IL‑1β, matrix metallopeptidases 2 and 9) to the control level. Further in vitro cell culture experiments using aortic smooth muscle cell (SMC) suggested that the inhibition of the mTOR signaling pathway by rapamycin could promote the differentiation of SMCs, as reflected by the reduced expression of S100A4 and osteopontin. The present study indicated that the early enhanced mTOR signaling pathway in the TAA development and mTOR inhibitor rapamycin may inhibit CaCl2‑induced TAA formation.

Downregulation of Calcium-Binding Protein S100A9 Inhibits Hypopharyngeal Cancer Cell Proliferation and Invasion Ability Through Inactivation of NF-κB Signaling.

PubMed