Pharmacological hypothesis: Nitric oxide-induced inhibition of ADAM-17 activity as well as vesicle release can in turn prevent the production of soluble endothelin-converting enzyme.

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Kuruppu, Sanjaya; Rajapakse, Niwanthi W; Parkington, Helena C; Smith, Ian

2017-10-01

Endothelin-1 (ET-1) and nitric oxide (NO) are two highly potent vasoactive molecules with opposing effects on the vasculature. Endothelin-converting enzyme (ECE) and nitric oxide synthase (NOS) catalyse the production of ET-1 and NO, respectively. It is well established that these molecules play a crucial role in the initiation and progression of cardiovascular diseases and have therefore become targets of therapy. Many studies have examined the mechanism(s) by which NO regulates ET-1 production. Expression and localization of ECE-1 is a key factor that determines the rate of ET-1 production. ECE-1 can either be membrane bound or be released from the cell surface to produce a soluble form. NO has been shown to reduce the expression of both membrane-bound and soluble ECE-1. Several studies have examined the mechanism(s) behind NO-mediated inhibition of ECE expression on the cell membrane. However, the precise mechanism(s) behind NO-mediated inhibition of soluble ECE production are unknown. We hypothesize that both exogenous and endogenous NO, inhibits the production of soluble ECE-1 by preventing its release via extracellular vesicles (e.g., exosomes), and/or by inhibiting the activity of A Disintegrin and Metalloprotease-17 (ADAM17). If this hypothesis is proven correct in future studies, these pathways represent targets for the therapeutic manipulation of soluble ECE-1 production. © 2017 The Authors. Pharmacology Research & Perspectives published by John Wiley & Sons Ltd, British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics.

Pharmacological inhibition of feline immunodeficiency virus (FIV).

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Mohammadi, Hakimeh; Bienzle, Dorothee

2012-05-01

Feline immunodeficiency virus (FIV) is a member of the retroviridae family of viruses and causes an acquired immunodeficiency syndrome (AIDS) in domestic and non-domestic cats worldwide. Genome organization of FIV and clinical characteristics of the disease caused by the virus are similar to those of human immunodeficiency virus (HIV). Both viruses infect T lymphocytes, monocytes and macrophages, and their replication cycle in infected cells is analogous. Due to marked similarity in genomic organization, virus structure, virus replication and disease pathogenesis of FIV and HIV, infection of cats with FIV is a useful tool to study and develop novel drugs and vaccines for HIV. Anti-retroviral drugs studied extensively in HIV infection have targeted different steps of the virus replication cycle: (1) inhibition of virus entry into susceptible cells at the level of attachment to host cell surface receptors and co-receptors; (2) inhibition of fusion of the virus membrane with the cell membrane; (3) blockade of reverse transcription of viral genomic RNA; (4) interruption of nuclear translocation and viral DNA integration into host genomes; (5) prevention of viral transcript processing and nuclear export; and (6) inhibition of virion assembly and maturation. Despite much success of anti-retroviral therapy slowing disease progression in people, similar therapy has not been thoroughly investigated in cats. In this article we review current pharmacological approaches and novel targets for anti-lentiviral therapy, and critically assess potentially suitable applications against FIV infection in cats.

Quercetin Inhibits Pulmonary Arterial Endothelial Cell Transdifferentiation Possibly by Akt and Erk1/2 Pathways

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Shian Huang

2017-01-01

Full Text Available This study aimed to investigate the effects and mechanisms of quercetin on pulmonary arterial endothelial cell (PAEC transdifferentiation into smooth muscle-like cells. TGF-β1-induced PAEC transdifferentiation models were applied to evaluate the pharmacological actions of quercetin. PAEC proliferation was detected with CCK8 method and BurdU immunocytochemistry. Meanwhile, the identification and transdifferentiation of PAECs were determined by FVIII immunofluorescence staining and α-SMA protein expression. The related mechanism was elucidated based on the levels of Akt and Erk1/2 signal pathways. As a result, quercetin effectively inhibited the TGF-β1-induced proliferation and transdifferentiation of the PAECs and activation of Akt/Erk1/2 cascade in the cells. In conclusion, quercetin is demonstrated to be effective for pulmonary arterial hypertension (PAH probably by inhibiting endothelial transdifferentiation possibly via modulating Akt and Erk1/2 expressions.

Non-specific chemical inhibition of the Fanconi anemia pathway sensitizes cancer cells to cisplatin

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Jacquemont Céline

2012-04-01

Full Text Available Abstract Background Platinum compounds such as cisplatin and carboplatin are DNA crosslinking agents widely used for cancer chemotherapy. However, the effectiveness of platinum compounds is often tempered by the acquisition of cellular drug resistance. Until now, no pharmacological approach has successfully overcome cisplatin resistance in cancer treatment. Since the Fanconi anemia (FA pathway is a DNA damage response pathway required for cellular resistance to DNA interstrand crosslinking agents, identification of small molecules that inhibit the FA pathway may reveal classes of chemicals that sensitize cancer cells to cisplatin. Results Through a cell-based screening assay of over 16,000 chemicals, we identified 26 small molecules that inhibit ionizing radiation and cisplatin-induced FANCD2 foci formation, a marker of FA pathway activity, in multiple human cell lines. Most of these small molecules also compromised ionizing radiation-induced RAD51 foci formation and homologous recombination repair, indicating that they are not selective toward the regulation of FANCD2. These compounds include known inhibitors of the proteasome, cathepsin B, lysosome, CHK1, HSP90, CDK and PKC, and several uncharacterized chemicals including a novel proteasome inhibitor (Chembridge compound 5929407. Isobologram analyses demonstrated that half of the identified molecules sensitized ovarian cancer cells to cisplatin. Among them, 9 demonstrated increased efficiency toward FA pathway-proficient, cisplatin-resistant ovarian cancer cells. Six small molecules, including bortezomib (proteasome inhibitor, CA-074-Me (cathepsin B inhibitor and 17-AAG (HSP90 inhibitor, synergized with cisplatin specifically in FA-proficient ovarian cancer cells (2008 + FANCF, but not in FA-deficient isogenic cells (2008. In addition, geldanamycin (HSP90 inhibitor and two CHK1 inhibitors (UCN-01 and SB218078 exhibited a significantly stronger synergism with cisplatin in FA

A PKA survival pathway inhibited by DPT-PKI, a new specific cell permeable PKA inhibitor, is induced by T. annulata in parasitized B-lymphocytes.

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Guergnon, Julien; Dessauge, Frederic; Traincard, François; Cayla, Xavier; Rebollo, Angelita; Bost, Pierre Etienne; Langsley, Gordon; Garcia, Alphonse

2006-08-01

T. annulata, an intracellular pathogenic parasite of the Aplicomplexa protozoan family infects bovine B-lymphocytes and macrophages. Parasitized cells that become transformed survive and proliferate independently of exogenous growth factors. In the present study, we used the isogenic non parasitized BL3 and parasitized TBL3 B cell lines, as a model to evaluate the contribution of two-major PI3-K- and PKA-dependent anti-apoptotic pathways in the survival of T. annulata parasitized B lymphocytes. We found that T. annulata increases PKA activity, induces over-expression of the catalytic subunit and down-regulates the pro-survival phosphorylation state of Akt/PKB. Consistent with a role of PKA activation in survival, two pharmacological inhibitors H89 and KT5720 ablate PKA-dependent survival of parasitized cells. To specifically inhibit PKA pro-survival pathways we linked the DPTsh1 peptide shuttle sequence to PKI(5-24) and we generated DPT-PKI, a cell permeable PKI. DPT-PKI specifically inhibited PKA activity in bovine cell extracts and, as expected, also inhibited the PKA-dependent survival of T. annulata parasitized TBL3 cells. Thus, parasite-dependent constitutive activation of PKA in TBL3 cells generates an anti-apoptotic pathway that can protect T. annulata-infected B cells from apoptosis. These results also indicate that DPT-PKI could be a powerful tool to inhibit PKA pathways in other cell types.

Inhibition of canonical WNT signaling pathway by β-catenin/CBP inhibitor ICG-001 ameliorates liver fibrosis in vivo through suppression of stromal CXCL12.

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Akcora, Büsra Öztürk; Storm, Gert; Bansal, Ruchi

2018-03-01

Quiescent hepatic stellate cells (HSCs), in response to liver injury, undergo characteristic morphological transformation into proliferative, contractile and ECM-producing myofibroblasts. In this study, we investigated the implication of canonical Wnt signaling pathway in HSCs and liver fibrogenesis. Canonical Wnt signaling pathway activation and inhibition using β-catenin/CBP inhibitor ICG001 was examined in-vitro in TGFβ-activated 3T3, LX2, primary human HSCs, and in-vivo in CCl 4 -induced acute liver injury mouse model. Fibroblasts-conditioned medium studies were performed to assess the Wnt-regulated paracrine factors involved in crosstalk between HSCs-macrophages and HSCs-endothelial cells. Canonical Wnt signaling pathway components were significantly up-regulated in-vitro and in-vivo. In-vitro, ICG-001 significantly inhibited fibrotic parameters, 3D-collagen contractility and wound healing. Conditioned medium induced fibroblasts-mediated macrophage and endothelial cells activation was significantly inhibited by ICG-001. In-vivo, ICG-001 significantly attenuated collagen accumulation and HSC activation. Interestingly, ICG-001 drastically inhibited macrophage infiltration, intrahepatic inflammation and angiogenesis. We further analyzed the paracrine factors involved in Wnt-mediated effects and found CXCL12 was significantly suppressed both in-vitro and in-vivo following Wnt inhibition. Wnt-regulated CXCL12 secretion from activated HSCs potentiated macrophage infiltration and activation, and angiogenesis. Pharmacological inhibition of canonical Wnt signaling pathway via suppression of stromal CXCL12 suggests a potential therapeutic approach targeting activated HSCs in liver fibrosis. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Pharmacological Inhibition of Feline Immunodeficiency Virus (FIV

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Dorothee Bienzle

2012-04-01

Full Text Available Feline immunodeficiency virus (FIV is a member of the retroviridae family of viruses and causes an acquired immunodeficiency syndrome (AIDS in domestic and non-domestic cats worldwide. Genome organization of FIV and clinical characteristics of the disease caused by the virus are similar to those of human immunodeficiency virus (HIV. Both viruses infect T lymphocytes, monocytes and macrophages, and their replication cycle in infected cells is analogous. Due to marked similarity in genomic organization, virus structure, virus replication and disease pathogenesis of FIV and HIV, infection of cats with FIV is a useful tool to study and develop novel drugs and vaccines for HIV. Anti-retroviral drugs studied extensively in HIV infection have targeted different steps of the virus replication cycle: (1 inhibition of virus entry into susceptible cells at the level of attachment to host cell surface receptors and co-receptors; (2 inhibition of fusion of the virus membrane with the cell membrane; (3 blockade of reverse transcription of viral genomic RNA; (4 interruption of nuclear translocation and viral DNA integration into host genomes; (5 prevention of viral transcript processing and nuclear export; and (6 inhibition of virion assembly and maturation. Despite much success of anti-retroviral therapy slowing disease progression in people, similar therapy has not been thoroughly investigated in cats. In this article we review current pharmacological approaches and novel targets for anti-lentiviral therapy, and critically assess potentially suitable applications against FIV infection in cats.

Atorvastatin inhibits insulin synthesis by inhibiting the Ras/Raf/ERK/CREB pathway in INS-1 cells

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Sun, Hongxi; Li, Yu; Sun, Bei; Hou, Ningning; Yang, Juhong; Zheng, Miaoyan; Xu, Jie; Wang, Jingyu; Zhang, Yi; Zeng, Xianwei; Shan, Chunyan; Chang, Bai; Chen, Liming; Chang, Baocheng

2016-01-01

Abstract Backround: Type 2 diabetes has become a global epidemic disease. Atorvastatin has become a cornerstone in the prevention and treatment of atherosclerosis. However, increasing evidence showed that statins can dose-dependently increase the risk of diabetes mellitus. The mechanism is not clear. Objective: The Ras complex pathway (Ras/Raf/extracellular signal-regulated kinase [ERK]/cAMP response element-binding protein [CREB]) is the major pathway that regulates the gene transcription. Except for the inhibition of cholesterol synthesis by inhibiting the 3-hydroxy-3-methyl glutaryl coenzyme A (HMG-COA) reductase, statins can also downregulate the phosphorylation of a series of downstream substrates including the key proteins of the Ras complex pathway, therefore may inhibit the insulin syntheses in pancreatic beta cells. In our study, we investigated the inhibitory effect and the underlying mechanism of atorvastatin on insulin synthesis in rat islets. Methods: Islets were isolated from Wistar rats and cultured in Roswell Park Memorial Institute (RPMI)-1640 medium. The insulin content in the medium was measured by radioimmunoassay before and after the treatment of 50 μM atorvastatin. Effect of atorvastatin on the expression of insulin message Ribonucleic acid (mRNA) in pancreatic islet beta cells was also detected using quantitative real-time polymerase chain reaction. Western blotting was used to explore the possible role of the Ras complex pathway (Ras/Raf/ERK/CREB) in atorvastatin-inhibited insulin synthesis. The effects of atorvastatin on the binding of nuclear transcription factor p-CREB with CRE in INS-1 cells were examined via chromatin immunoprecipitation assay. Results: Compared with the control group, the insulin level decreased by 27.1% at 24 hours after atorvastatin treatment. Atorvastatin inhibited insulin synthesis by decreasing insulin mRNA expression of pancreatic islet beta cells. The activities of Ras, Raf-1, and p-CREB in the Ras complex

Inhibition of the Autophagy Pathway Synergistically Potentiates the Cytotoxic Activity of Givinostat(ITF2357on Human Glioblastoma Cancer Stem Cells

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Francesca Angeletti

2016-10-01

Full Text Available Increasing evidence highlighted the role of cancer stem cells (CSCs in the development of tumor resistance to therapy, particularly in glioblastoma (GBM. Therefore, the development of new therapies, specifically directed against GBM CSCs, constitutes an important research avenue. Considering the extended range of cancer-related pathways modulated by histone acetylation/deacetylation processes, we studied the anti-proliferative and pro-apoptotic efficacy of givinostat (GVS, a pan-histone deacetylase inhibitor, on cell cultures enriched in CSCs, isolated from nine human GBMs. We report that GVS induced a significant reduction of viability and self-renewal ability in all GBM CSC cultures; conversely, GVS exposure did not cause a significant cytotoxic activity toward differentiated GBM cells and normal mesenchymal human stem cells.Analysing the cellular and molecular mechanisms involved, we demonstrated that GVS affected CSC viability through the activation of programmed cell death pathways. In particular, a marked stimulation of macroautophagy was observed after GVS treatment. To understand the functional link between GVS treatment and autophagy activation, different genetic and pharmacological interfering strategies were used. We show that the up-regulation of the autophagy process, obtained by deprivation of growth factors, induced a reduction of CSC sensitivity to GVS, while the pharmacological inhibition of the autophagy pathway and the silencing of the key autophagy gene ATG7, increased the cell death rate induced by GVS. Altogether these findings suggest that autophagy represents a pro-survival mechanism activated by GBM CSCs to counteract the efficacy of the anti-proliferative activity of GVS. In conclusion, we demonstrate that GVS is a novel pharmacological tool able to target GBM CSC viability and its efficacy can be enhanced by autophagy inhibitory strategies.

Ketoconazole inhibits the cellular uptake of anandamide via inhibition of FAAH at pharmacologically relevant concentrations.

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Emmelie Björklund

Full Text Available The antifungal compound ketoconazole has, in addition to its ability to interfere with fungal ergosterol synthesis, effects upon other enzymes including human CYP3A4, CYP17, lipoxygenase and thromboxane synthetase. In the present study, we have investigated whether ketoconazole affects the cellular uptake and hydrolysis of the endogenous cannabinoid receptor ligand anandamide (AEA.The effects of ketoconazole upon endocannabinoid uptake were investigated using HepG2, CaCo2, PC-3 and C6 cell lines. Fatty acid amide hydrolase (FAAH activity was measured in HepG2 cell lysates and in intact C6 cells. Ketoconazole inhibited the uptake of AEA by HepG2 cells and CaCo2 cells with IC50 values of 17 and 18 µM, respectively. In contrast, it had modest effects upon AEA uptake in PC-3 cells, which have a low expression of FAAH. In cell-free HepG2 lysates, ketoconazole inhibited FAAH activity with an IC50 value (for the inhibitable component of 34 µM.The present study indicates that ketoconazole can inhibit the cellular uptake of AEA at pharmacologically relevant concentrations, primarily due to its effects upon FAAH. Ketoconazole may be useful as a template for the design of dual-action FAAH/CYP17 inhibitors as a novel strategy for the treatment of prostate cancer.

Inhibition of the adrenomedullin/nitric oxide signaling pathway in early diabetic retinopathy.

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Blom, Jan J; Giove, Thomas J; Favazza, Tara L; Akula, James D; Eldred, William D

2011-06-01

The nitric oxide (NO) signaling pathway is integrally involved in visual processing and changes in the NO pathway are measurable in eyes of diabetic patients. The small peptide adrenomedullin (ADM) can activate a signaling pathway to increase the enzyme activity of neuronal nitric oxide synthase (nNOS). ADM levels are elevated in eyes of diabetic patients and therefore, ADM may play a role in the pathology of diabetic retinopathy. The goal of this research was to test the effects of inhibiting the ADM/NO signaling pathway in early diabetic retinopathy. Inhibition of this pathway decreased NO production in high-glucose retinal cultures. Treating diabetic mice with the PKC β inhibitor ruboxistaurin for 5 weeks lowered ADM mRNA levels and ADM-like immunoreactivity and preserved retinal function as assessed by electroretinography. The results of this study indicate that inhibiting the ADM/NO signaling pathway prevents neuronal pathology and functional losses in early diabetic retinopathy.

The MEK1/2-ERK Pathway Inhibits Type I IFN Production in Plasmacytoid Dendritic Cells

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Vaclav Janovec

2018-02-01

Full Text Available Recent studies have reported that the crosslinking of regulatory receptors (RRs, such as blood dendritic cell antigen 2 (BDCA-2 (CD303 or ILT7 (CD85g, of plasmacytoid dendritic cells (pDCs efficiently suppresses the production of type I interferons (IFN-I, α/β/ω and other cytokines in response to toll-like receptor 7 and 9 (TLR7/9 ligands. The exact mechanism of how this B cell receptor (BCR-like signaling blocks TLR7/9-mediated IFN-I production is unknown. Here, we stimulated BCR-like signaling by ligation of RRs with BDCA-2 and ILT7 mAbs, hepatitis C virus particles, or BST2 expressing cells. We compared BCR-like signaling in proliferating pDC cell line GEN2.2 and in primary pDCs from healthy donors, and addressed the question of whether pharmacological targeting of BCR-like signaling can antagonize RR-induced pDC inhibition. To this end, we tested the TLR9-mediated production of IFN-I and proinflammatory cytokines in pDCs exposed to a panel of inhibitors of signaling molecules involved in BCR-like, MAPK, NF-ĸB, and calcium signaling pathways. We found that MEK1/2 inhibitors, PD0325901 and U0126 potentiated TLR9-mediated production of IFN-I in GEN2.2 cells. More importantly, MEK1/2 inhibitors significantly increased the TLR9-mediated IFN-I production blocked in both GEN2.2 cells and primary pDCs upon stimulation of BCR-like or phorbol 12-myristate 13-acetate-induced protein kinase C (PKC signaling. Triggering of BCR-like and PKC signaling in pDCs resulted in an upregulation of the expression and phoshorylation of c-FOS, a downstream gene product of the MEK1/2-ERK pathway. We found that the total level of c-FOS was higher in proliferating GEN2.2 cells than in the resting primary pDCs. The PD0325901-facilitated restoration of the TLR9-mediated IFN-I production correlated with the abrogation of MEK1/2-ERK-c-FOS signaling. These results indicate that the MEK1/2-ERK pathway inhibits TLR9-mediated type I IFN production in pDCs and that

Quercetin-6-C-β-D-glucopyranoside, natural analog of quercetin exhibits anti-prostate cancer activity by inhibiting Akt-mTOR pathway via aryl hydrocarbon receptor.

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Hamidullah; Kumar, Rajeev; Saini, Karan Singh; Kumar, Amit; Kumar, Sudhir; Ramakrishna, E; Maurya, Rakesh; Konwar, Rituraj; Chattopadhyay, Naibedya

2015-12-01

Pre-clinical studies suggest mitigating effect of dietary flavonoid quercetin against cancer and other diseases. However, quercetin suffers from poor metabolic stability, which appears to offset its pharmacological efficacy. Recently, we isolated quercetin-6-C-β-D-glucopyranoside (QCG) from Ulmus wallichiana planchon that has greater stability profile over quercetin. In the present study, the cytotoxic and apoptotic effects of QCG on prostate cancer cells were assessed. QCG inhibited prostate cancer cell proliferation by arresting cells at G0/G1 phase of cell cycle and induces apoptosis as evident from cytochrome c release, cleavage of caspase 3 and poly (ADP-ribose) polymerase. Mechanistic studies revealed that QCG inhibited reactive oxygen species (ROS) generation and Akt/mTOR cell survival pathways. Aryl hydrocarbon receptor (AhR) was a critical mediator of QCG action as knockdown of AhR attenuated QCG-induced cell cycle arrest, apoptosis and inhibition of Akt/mTOR pathway in prostate cancer cells. Taken together, our results suggest that QCG exhibits anti-cancer activity against prostate cancer cells via AhR-mediated down regulation of Akt/mTOR pathway in PC-3 cells. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Formation of distinct inclusion bodies by inhibition of ubiquitin-proteasome and autophagy-lysosome pathways.

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Lee, Junho; Yang, Kyu-Hwan; Joe, Cheol O; Kang, Seok-Seong

2011-01-14

Accumulation of misfolded proteins is caused by the impairment of protein quality control systems, such as ubiquitin-proteasome pathway (UPP) and autophagy-lysosome pathway (ALP). In this study, the formation of inclusion bodies was examined after the blockade of UPP and/or ALP in A549 cells. UPP inhibition induced a single and large inclusion body localized in microtubule-organizing center. Interestingly, however, ALP inhibition generated dispersed small inclusion bodies in the cytoplasm. Tuberous sclerosis complex 2 was selectively accumulated in the inclusion bodies of UPP-inhibited cells, but not those of ALP-inhibited cells. Blockade of transcription and translation entirely inhibited the formation of inclusion body induced by UPP inhibition, but partially by ALP inhibition. Moreover, the simultaneous inhibition of two protein catabolic pathways independently developed two distinct inclusion bodies within a single cell. These findings clearly demonstrated that dysfunction of each catabolic pathway induced formation and accumulation of unique inclusion bodies on the basis of morphology, localization and formation process in A549 cells. Copyright © 2010 Elsevier Inc. All rights reserved.

Targeting multiple cannabinoid anti-tumour pathways with a resorcinol derivative leads to inhibition of advanced stages of breast cancer.

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Murase, Ryuichi; Kawamura, Rumi; Singer, Eric; Pakdel, Arash; Sarma, Pranamee; Judkins, Jonathon; Elwakeel, Eiman; Dayal, Sonali; Martinez-Martinez, Esther; Amere, Mukkanti; Gujjar, Ramesh; Mahadevan, Anu; Desprez, Pierre-Yves; McAllister, Sean D

2014-10-01

The psychoactive cannabinoid Δ(9) -tetrahydrocannabinol (THC) and the non-psychoactive cannabinoid cannabidiol (CBD) can both reduce cancer progression, each through distinct anti-tumour pathways. Our goal was to discover a compound that could efficiently target both cannabinoid anti-tumour pathways. To measure breast cancer cell proliferation/viability and invasion, MTT and Boyden chamber assays were used. Modulation of reactive oxygen species (ROS) and apoptosis was measured using dichlorodihydrofluorescein and annexin/propidium iodide, respectively, in combination with cell flow cytometry. Changes in protein levels were evaluated using Western analysis. Orthotopic and i.v. mouse models of breast cancer metastasis were used to test the activity of cannabinoids in vivo. CBD reduced breast cancer metastasis in advanced stages of the disease as the direct result of down-regulating the transcriptional regulator Id1. However, this was associated with moderate increases in survival. We therefore screened for analogues that could co-target cannabinoid anti-tumour pathways (CBD- and THC-associated) and discovered the compound O-1663. This analogue inhibited Id1, produced a marked stimulation of ROS, up-regulated autophagy and induced apoptosis. Of all the compounds tested, it was the most potent at inhibiting breast cancer cell proliferation and invasion in culture and metastasis in vivo. O-1663 prolonged survival in advanced stages of breast cancer metastasis. Developing compounds that can simultaneously target multiple cannabinoid anti-tumour pathways efficiently may provide a novel approach for the treatment of patients with metastatic breast cancer. © 2014 The British Pharmacological Society.

Caenorhabditis elegans as Model System in Pharmacology and Toxicology: Effects of Flavonoids on Redox-Sensitive Signalling Pathways and Ageing

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Karoline Koch

2014-01-01

Full Text Available Flavonoids are secondary plant compounds that mediate diverse biological activities, for example, by scavenging free radicals and modulating intracellular signalling pathways. It has been shown in various studies that distinct flavonoid compounds enhance stress resistance and even prolong the life span of organisms. In the last years the model organism C. elegans has gained increasing importance in pharmacological and toxicological sciences due to the availability of various genetically modified nematode strains, the simplicity of modulating genes by RNAi, and the relatively short life span. Several studies have been performed demonstrating that secondary plant compounds influence ageing, stress resistance, and distinct signalling pathways in the nematode. Here we present an overview of the modulating effects of different flavonoids on oxidative stress, redox-sensitive signalling pathways, and life span in C. elegans introducing the usability of this model system for pharmacological and toxicological research.

Caenorhabditis elegans as Model System in Pharmacology and Toxicology: Effects of Flavonoids on Redox-Sensitive Signalling Pathways and Ageing

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Koch, Karoline; Havermann, Susannah; Büchter, Christian

2014-01-01

Flavonoids are secondary plant compounds that mediate diverse biological activities, for example, by scavenging free radicals and modulating intracellular signalling pathways. It has been shown in various studies that distinct flavonoid compounds enhance stress resistance and even prolong the life span of organisms. In the last years the model organism C. elegans has gained increasing importance in pharmacological and toxicological sciences due to the availability of various genetically modified nematode strains, the simplicity of modulating genes by RNAi, and the relatively short life span. Several studies have been performed demonstrating that secondary plant compounds influence ageing, stress resistance, and distinct signalling pathways in the nematode. Here we present an overview of the modulating effects of different flavonoids on oxidative stress, redox-sensitive signalling pathways, and life span in C. elegans introducing the usability of this model system for pharmacological and toxicological research. PMID:24895670

Formation of distinct inclusion bodies by inhibition of ubiquitin-proteasome and autophagy-lysosome pathways

International Nuclear Information System (INIS)

Lee, Junho; Yang, Kyu-Hwan; Joe, Cheol O.; Kang, Seok-Seong

2011-01-01

Research highlights: → Distinct inclusion bodies are developed by inhibition of UPP and ALP. → The inclusion bodies differ in morphology, localization and formation process. → The inclusion bodies are distinguishable by the localization of TSC2. → Inhibition of both UPP and ALP simultaneously induces those inclusion bodies. -- Abstract: Accumulation of misfolded proteins is caused by the impairment of protein quality control systems, such as ubiquitin-proteasome pathway (UPP) and autophagy-lysosome pathway (ALP). In this study, the formation of inclusion bodies was examined after the blockade of UPP and/or ALP in A549 cells. UPP inhibition induced a single and large inclusion body localized in microtubule-organizing center. Interestingly, however, ALP inhibition generated dispersed small inclusion bodies in the cytoplasm. Tuberous sclerosis complex 2 was selectively accumulated in the inclusion bodies of UPP-inhibited cells, but not those of ALP-inhibited cells. Blockade of transcription and translation entirely inhibited the formation of inclusion body induced by UPP inhibition, but partially by ALP inhibition. Moreover, the simultaneous inhibition of two protein catabolic pathways independently developed two distinct inclusion bodies within a single cell. These findings clearly demonstrated that dysfunction of each catabolic pathway induced formation and accumulation of unique inclusion bodies on the basis of morphology, localization and formation process in A549 cells.

Fenofibrate inhibits atrial metabolic remodelling in atrial fibrillation through PPAR-α/sirtuin 1/PGC-1α pathway.

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Liu, Guang-Zhong; Hou, Ting-Ting; Yuan, Yue; Hang, Peng-Zhou; Zhao, Jing-Jing; Sun, Li; Zhao, Guan-Qi; Zhao, Jing; Dong, Jing-Mei; Wang, Xiao-Bing; Shi, Hang; Liu, Yong-Wu; Zhou, Jing-Hua; Dong, Zeng-Xiang; Liu, Yang; Zhan, Cheng-Chuang; Li, Yue; Li, Wei-Min

2016-03-01

Atrial metabolic remodelling is critical for the process of atrial fibrillation (AF). The PPAR-α/sirtuin 1 /PPAR co-activator α (PGC-1α) pathway plays an important role in maintaining energy metabolism. However, the effect of the PPAR-α agonist fenofibrate on AF is unclear. Therefore, the aim of this study was to determine the effect of fenofibrate on atrial metabolic remodelling in AF and explore its possible mechanisms of action. The expression of metabolic proteins was examined in the left atria of AF patients. Thirty-two rabbits were divided into sham, AF (pacing with 600 beats·min(-1) for 1 week), fenofibrate treated (pretreated with fenofibrate before pacing) and fenofibrate alone treated (for 2 weeks) groups. HL-1 cells were subjected to rapid pacing in the presence or absence of fenofibrate, the PPAR-α antagonist GW6471 or sirtuin 1-specific inhibitor EX527. Metabolic factors, circulating biochemical metabolites, atrial electrophysiology, adenine nucleotide levels and accumulation of glycogen and lipid droplets were assessed. The PPAR-α/sirtuin 1/PGC-1α pathway was significantly inhibited in AF patients and in the rabbit/HL-1 cell models, resulting in a reduction of key downstream metabolic factors; this effect was significantly restored by fenofibrate. Fenofibrate prevented the alterations in circulating biochemical metabolites, reduced the level of adenine nucleotides and accumulation of glycogen and lipid droplets, reversed the shortened atrial effective refractory period and increased risk of AF. Fenofibrate inhibited atrial metabolic remodelling in AF by regulating the PPAR-α/sirtuin 1/PGC-1α pathway. The present study may provide a novel therapeutic strategy for AF. © 2016 The British Pharmacological Society.

Lactobacillus bulgaricus OLL1181 activates the aryl hydrocarbon receptor pathway and inhibits colitis

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Takamura, Takeyuki; Harama, Daisuke; Fukumoto, Suguru; Nakamura, Yuki; Shimokawa, Naomi; Ishimaru, Kayoko; Ikegami, Shuji; Makino, Seiya; Kitamura, Masanori; Nakao, Atsuhito

2011-01-01

Increasing evidence suggests that the aryl hydrocarbon receptor (AhR) pathway has an important role in the regulation of inflammatory responses. Most recently, we have shown that the activation of the AhR pathway by a potent AhR agonist inhibits the development of dextran sodium sulfate (DSS)-induced colitis, a model of human ulcerative colitis, by the induction of prostaglandin E2 (PGE2) in the large intestine. Because several strains of probiotic lactic acid bacteria have been reported to inhibit DSS-induced colitis by unidentified mechanisms, we hypothesized that particular strains of lactic acid bacterium might have the potential to activate the AhR pathway, thereby inhibiting DSS-induced colitis. This study investigated whether there are specific lactic acid bacterial strains that can activate the AhR pathway, and if so, whether this AhR-activating potential is associated with suppression of DSS-induced colitis. By using AhR signaling reporter cells, we found that Lactobacillus bulgaricus OLL1181 had the potential to activate the AhR pathway. OLL1181 also induced the mRNA expression of cytochrome P450 family 1A1 (CYP1A1), a target gene of the AhR pathway, in human colon cells, which was inhibited by the addition of an AhR antagonist, α-naphthoflavon (αNF). In addition, mice treated orally with OLL1181 showed an increase in CYP1A1 mRNA expression in the large intestine and amelioration of DSS-induced colitis. Thus, OLL1181 can induce activation of the intestinal AhR pathway and inhibit DSS-induced colitis in mice. This strain of lactic acid bacterium has therefore the potential to activate the AhR pathway, which may be able to suppress colitis. PMID:21321579

Biological and Pharmacological properties

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Biological and Pharmacological properties. NOEA inhibits Ceramidase. Anandamide inhibits gap junction conductance and reduces sperm fertilizing capacity. Endogenous ligands for Cannabinoid receptors (anandamide and NPEA). Antibacterial and antiviral ...

Reduced RAC1 activity inhibits cell proliferation and induces apoptosis in neurofibromatosis type 2(NF2)-associated schwannoma.

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Wang, Ying; Wang, Bo; Li, Peng; Zhang, Qi; Liu, Pinan

2017-12-01

Objective To study the function and potential mechanism of RAC1 inhibitors in NF2-associated schwannoma. Methods In this study, we the downregulation of RAC1 activity and tumor cell phenotypes by RAC1 inhibitor NSC23766 in vitro. And we further validated the anti-proliferation effect by this RAC1 inhibitor in subcutaneous xenograft tumor model and sciatic nerve model. Results Pharmacological inhibition of RAC1 could significantly inhibit the proliferation of both RT4 cells and human NF2-associated primary schwannoma cells by inducing apoptosis. Pharmacological inhibition of RAC1 effectively reduced Rac1 activity and down-regulated the pathway downstream of Rac. Moreover, pharmacological inhibition of RAC1 showed a potential antitumor effect, with low toxicity in vivo. Conclusion RAC1 inhibitors may play a therapeutic role in patients with schwannoma.

Linderane Suppresses Hepatic Gluconeogenesis by Inhibiting the cAMP/PKA/CREB Pathway Through Indirect Activation of PDE 3 via ERK/STAT3

Directory of Open Access Journals (Sweden)

Wei Xie

2018-05-01

Full Text Available The role of phosphodiesterase 3 (PDE3, a cyclic AMP (cAMP-degrading enzyme, in modulating gluconeogenesis remains unknown. Here, linderane, a natural compound, was found to inhibit gluconeogenesis by activating hepatic PDE3 in rat primary hepatocytes. The underlying molecular mechanism and its effects on whole-body glucose and lipid metabolism were investigated. The effect of linderane on gluconeogenesis, cAMP content, phosphorylation of cAMP-response element-binding protein (CREB and PDE activity were examined in cultured primary hepatocytes and C57BL/6J mice. The precise mechanism by which linderane activates PDE3 and inhibits the cAMP pathway was explored using pharmacological inhibitors. The amelioration of metabolic disorders was observed in ob/ob mice. Linderane inhibited gluconeogenesis, reduced phosphoenolpyruvate carboxykinase (Pck1 and glucose-6-phosphatase (G6pc gene expression, and decreased intracellular cAMP concentration and CREB phosphorylation in rat primary hepatocytes under both basal and forskolin-stimulated conditions. In rat primary hepatocytes, it also increased total PDE and PDE3 activity but not PDE4 activity. The suppressive effect of linderane on the cAMP pathway and gluconeogenesis was abolished by the non-specific PDE inhibitor 3-isobutyl-1-methylxanthine (IBMX and the specific PDE3 inhibitor cilostazol. Linderane indirectly activated PDE3 through extracellular regulated protein kinase 1/2 (ERK1/2 and signal transducer and activator of transcription 3 (STAT3 activation. Linderane improved glucose and lipid metabolism after chronic oral administration in ob/ob mice. Our findings revealed linderane as an indirect PDE3 activator that suppresses gluconeogenesis through cAMP pathway inhibition and has beneficial effects on metabolic syndromes in ob/ob mice. This investigation highlighted the potential for PDE3 activation in the treatment of type 2 diabetes.

Neurotransmitter signaling pathways required for normal development in Xenopus laevis embryos: a pharmacological survey screen.

Science.gov (United States)

Sullivan, Kelly G; Levin, Michael

2016-10-01

Neurotransmitters are not only involved in brain function but are also important signaling molecules for many diverse cell types. Neurotransmitters are widely conserved, from evolutionarily ancient organisms lacking nervous systems through man. Here, results are reported from a loss- and gain-of-function survey, using pharmacological modulators of several neurotransmitter pathways to examine possible roles for these pathways in normal embryogenesis. Applying reagents targeting the glutamatergic, adrenergic and dopaminergic pathways to embryos of Xenopus laevis from gastrulation to organogenesis stages, we observed and quantified numerous malformations, including craniofacial defects, hyperpigmentation, muscle mispatterning and miscoiling of the gut. These data implicate several key neurotransmitters in new embryonic patterning roles, reveal novel earlier stages for processes involved in eye development, suggest new targets for subsequent molecular-genetic investigation, and highlight the necessity for in-depth toxicology studies of psychoactive compounds to which human embryos might be exposed during pregnancy. © 2016 Anatomical Society.

GABA, not glycine, mediates inhibition of latent respiratory motor pathways after spinal cord injury

OpenAIRE

Zimmer, M. Beth; Goshgarian, Harry G.

2006-01-01

Previous work has shown that latent respiratory motor pathways known as crossed phrenic pathways are inhibited via a spinal inhibitory process; however, the underlying mechanisms remain unknown. The present study investigated whether spinal GABA-A and/or glycine receptors are involved in the inhibition of the crossed phrenic pathways after a C2 spinal cord hemisection injury. Under ketamine/xylazine anesthesia, adult, female, Sprague Dawley rats were hemisected at the C2 spinal cord level. Fo...

Modulation of Olfactory Bulb Network Activity by Serotonin: Synchronous Inhibition of Mitral Cells Mediated by Spatially Localized GABAergic Microcircuits

Science.gov (United States)

Schmidt, Loren J.; Strowbridge, Ben W.

2014-01-01

Although inhibition has often been proposed as a central mechanism for coordinating activity in the olfactory system, relatively little is known about how activation of different inhibitory local circuit pathways can generate coincident inhibition of principal cells. We used serotonin (5-HT) as a pharmacological tool to induce spiking in ensembles…

Herpes simplex virus triggers activation of calcium-signaling pathways

Science.gov (United States)

Cheshenko, Natalia; Del Rosario, Brian; Woda, Craig; Marcellino, Daniel; Satlin, Lisa M.; Herold, Betsy C.

2003-01-01

The cellular pathways required for herpes simplex virus (HSV) invasion have not been defined. To test the hypothesis that HSV entry triggers activation of Ca2+-signaling pathways, the effects on intracellular calcium concentration ([Ca2+]i) after exposure of cells to HSV were examined. Exposure to virus results in a rapid and transient increase in [Ca2+]i. Pretreatment of cells with pharmacological agents that block release of inositol 1,4,5-triphosphate (IP3)–sensitive endoplasmic reticulum stores abrogates the response. Moreover, treatment of cells with these pharmacological agents inhibits HSV infection and prevents focal adhesion kinase (FAK) phosphorylation, which occurs within 5 min after viral infection. Viruses deleted in glycoprotein L or glycoprotein D, which bind but do not penetrate, fail to induce a [Ca2+]i response or trigger FAK phosphorylation. Together, these results support a model for HSV infection that requires activation of IP3-responsive Ca2+-signaling pathways and that is associated with FAK phosphorylation. Defining the pathway of viral invasion may lead to new targets for anti-viral therapy. PMID:14568989

GAS6/TAM Pathway Signaling in Hemostasis and Thrombosis.

Science.gov (United States)

Law, Luke A; Graham, Douglas K; Di Paola, Jorge; Branchford, Brian R

2018-01-01

The GAS6/TYRO3-AXL-MERTK (TAM) signaling pathway is essential for full and sustained platelet activation, as well as thrombus stabilization. Inhibition of this pathway decreases platelet aggregation, shape change, clot retraction, aggregate formation under flow conditions, and surface expression of activation markers. Transgenic mice deficient in GAS6, or any of the TAM family of receptors that engage this ligand, exhibit in vivo protection against arterial and venous thrombosis but do not demonstrate either spontaneous or prolonged bleeding compared to their wild-type counterparts. Comparable results are observed in wild-type mice treated with pharmacological inhibitors of the GAS6-TAM pathway. Thus, GAS6/TAM inhibition offers an attractive novel therapeutic option that may allow for a moderate reduction in platelet activation and decreased thrombosis while still permitting the primary hemostatic function of platelet plug formation.

Pharmacological inhibition of Polo Like Kinase 2 (PLK2) does not cause chromosomal damage or result in the formation of micronuclei

International Nuclear Information System (INIS)

Fitzgerald, Kent; Bergeron, Marcelle; Willits, Christopher; Bowers, Simeon; Aubele, Danielle L.; Goldbach, Erich; Tonn, George; Ness, Daniel; Olaharski, Andrew

2013-01-01

Polo Like Kinase 2 (PLK2) phosphorylates α-synuclein and is considered a putative therapeutic target for Parkinson's disease. Several lines of evidence indicate that PLK2 is involved with proper centriole duplication and cell cycle regulation, inhibition of which could impact chromosomal integrity during mitosis. The objectives of the series of experiments presented herein were to assess whether specific inhibition of PLK2 is genotoxic and determine if PLK2 could be considered a tractable pharmacological target for Parkinson's disease. Several selective PLK2 inhibitors, ELN 582175 and ELN 582646, and their inactive enantiomers, ELN 582176 and ELN 582647, did not significantly increase the number of micronuclei in the in vitro micronucleus assay. ELN 582646 was administered to male Sprague Dawley rats in an exploratory 14-day study where flow cytometric analysis of peripheral blood identified a dose-dependent increase in the number of micronucleated reticulocytes. A follow-up investigative study demonstrated that ELN 582646 administered to PLK2 deficient and wildtype mice significantly increased the number of peripheral micronucleated reticulocytes in both genotypes, suggesting that ELN 582646-induced genotoxicity is not through the inhibition of PLK2. Furthermore, significant reduction of retinal phosphorylated α-synuclein levels was observed at three non-genotoxic doses, additional data to suggest that pharmacological inhibition of PLK2 is not the cause of the observed genotoxicity. These data, in aggregate, indicate that PLK2 inhibition is a tractable CNS pharmacological target that does not cause genotoxicity at doses and exposures that engage the target in the sensory retina. - Highlights: • Active and inactive enantiomers test negative in the in vitro micronucleus test. • ELN 582646 significantly increased micronuclei at 100 and 300 mg/kg/day doses. • ELN 582646 significantly increased micronuclei in PLK2 knockout mice. • ELN 582646 decreased

Pharmacological inhibition of Polo Like Kinase 2 (PLK2) does not cause chromosomal damage or result in the formation of micronuclei

Energy Technology Data Exchange (ETDEWEB)

Fitzgerald, Kent, E-mail: Kent.fitzgerald@elan.com [Pharmacological Sciences, Elan Pharmaceuticals Inc., 180 Oyster Point Boulevard, South San Francisco, CA 94080 (United States); Bergeron, Marcelle, E-mail: Marcelle.bergeron@elan.com [Pharmacological Sciences, Elan Pharmaceuticals Inc., 180 Oyster Point Boulevard, South San Francisco, CA 94080 (United States); Willits, Christopher, E-mail: Chris.willits@elan.com [Pharmacological Sciences, Elan Pharmaceuticals Inc., 180 Oyster Point Boulevard, South San Francisco, CA 94080 (United States); Bowers, Simeon, E-mail: Simeon.bowers@elan.com [Chemistry, Elan Pharmaceuticals Inc., 180 Oyster Point Boulevard, South San Francisco, CA 94080 (United States); Aubele, Danielle L., E-mail: Danielle.aubele@elan.com [Chemistry, Elan Pharmaceuticals Inc., 180 Oyster Point Boulevard, South San Francisco, CA 94080 (United States); Goldbach, Erich, E-mail: Erich.goldbach@elan.com [Drug Metabolism and Pharmacokinetics, Elan Pharmaceuticals Inc., 180 Oyster Point Boulevard, South San Francisco, CA 94080 (United States); Tonn, George, E-mail: George.tonn@elan.com [Drug Metabolism and Pharmacokinetics, Elan Pharmaceuticals Inc., 180 Oyster Point Boulevard, South San Francisco, CA 94080 (United States); Ness, Daniel, E-mail: Dan.ness@elan.com [Nonclinical Safety Evaluation, Elan Pharmaceuticals Inc., 180 Oyster Point Boulevard, South San Francisco, CA 94080 (United States); Olaharski, Andrew, E-mail: andrew.olaharski@agios.com [Nonclinical Safety Evaluation, Elan Pharmaceuticals Inc., 180 Oyster Point Boulevard, South San Francisco, CA 94080 (United States)

2013-05-15

Polo Like Kinase 2 (PLK2) phosphorylates α-synuclein and is considered a putative therapeutic target for Parkinson's disease. Several lines of evidence indicate that PLK2 is involved with proper centriole duplication and cell cycle regulation, inhibition of which could impact chromosomal integrity during mitosis. The objectives of the series of experiments presented herein were to assess whether specific inhibition of PLK2 is genotoxic and determine if PLK2 could be considered a tractable pharmacological target for Parkinson's disease. Several selective PLK2 inhibitors, ELN 582175 and ELN 582646, and their inactive enantiomers, ELN 582176 and ELN 582647, did not significantly increase the number of micronuclei in the in vitro micronucleus assay. ELN 582646 was administered to male Sprague Dawley rats in an exploratory 14-day study where flow cytometric analysis of peripheral blood identified a dose-dependent increase in the number of micronucleated reticulocytes. A follow-up investigative study demonstrated that ELN 582646 administered to PLK2 deficient and wildtype mice significantly increased the number of peripheral micronucleated reticulocytes in both genotypes, suggesting that ELN 582646-induced genotoxicity is not through the inhibition of PLK2. Furthermore, significant reduction of retinal phosphorylated α-synuclein levels was observed at three non-genotoxic doses, additional data to suggest that pharmacological inhibition of PLK2 is not the cause of the observed genotoxicity. These data, in aggregate, indicate that PLK2 inhibition is a tractable CNS pharmacological target that does not cause genotoxicity at doses and exposures that engage the target in the sensory retina. - Highlights: • Active and inactive enantiomers test negative in the in vitro micronucleus test. • ELN 582646 significantly increased micronuclei at 100 and 300 mg/kg/day doses. • ELN 582646 significantly increased micronuclei in PLK2 knockout mice. • ELN 582646

Pharmacological TLR4 Inhibition Protects against Acute and Chronic Fat-Induced Insulin Resistance in Rats.

Science.gov (United States)

Zhang, Ning; Liang, Hanyu; Farese, Robert V; Li, Ji; Musi, Nicolas; Hussey, Sophie E

2015-01-01

To evaluate whether pharmacological TLR4 inhibition protects against acute and chronic fat-induced insulin resistance in rats. For the acute experiment, rats received a TLR4 inhibitor [TAK-242 or E5564 (2x5 mg/kg i.v. bolus)] or vehicle, and an 8-h Intralipid (20%, 8.5 mg/kg/min) or saline infusion, followed by a two-step hyperinsulinemic-euglycemic clamp. For the chronic experiment, rats were subcutaneously implanted with a slow-release pellet of TAK-242 (1.5 mg/d) or placebo. Rats then received a high fat diet (HFD) or a low fat control diet (LFD) for 10 weeks, followed by a two-step insulin clamp. Acute experiment; the lipid-induced reduction (18%) in insulin-stimulated glucose disposal (Rd) was attenuated by TAK-242 and E5564 (the effect of E5564 was more robust), suggesting improved peripheral insulin action. Insulin was able to suppress hepatic glucose production (HGP) in saline- but not lipid-treated rats. TAK-242, but not E5564, partially restored this effect, suggesting improved HGP. Chronic experiment; insulin-stimulated Rd was reduced ~30% by the HFD, but completely restored by TAK-242. Insulin could not suppress HGP in rats fed a HFD and TAK-242 had no effect on HGP. Pharmacological TLR4 inhibition provides partial protection against acute and chronic fat-induced insulin resistance in vivo.

Combined inhibition of p38 and Akt signaling pathways abrogates cyclosporine A-mediated pathogenesis of aggressive skin SCCs

Energy Technology Data Exchange (ETDEWEB)

Arumugam, Aadithya; Walsh, Stephanie B.; Xu, Jianmin; Afaq, Farrukh [Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294-0019 (United States); Elmets, Craig A. [Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294-0019 (United States); Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL 35294 (United States); Athar, Mohammad, E-mail: mathar@uab.edu [Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294-0019 (United States); Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL 35294 (United States)

2012-08-24

Highlights: Black-Right-Pointing-Pointer p38 and Akt are the crucial molecular targets in the pathogenesis of SCCs in OTRs. Black-Right-Pointing-Pointer Combined inhibition of these targets diminished tumor growth by 90%. Black-Right-Pointing-Pointer Inhibition of these targets act through downregulating mTOR signaling pathway. -- Abstract: Non-melanoma skin cancers (NMSCs) are the most common neoplasm in organ transplant recipients (OTRs). These cancers are more invasive and metastatic as compared to those developed in normal cohorts. Previously, we have shown that immunosuppressive drug, cyclosporine A (CsA) directly alters tumor phenotype of cutaneous squamous cell carcinomas (SCCs) by activating TGF-{beta} and TAK1/TAB1 signaling pathways. Here, we identified novel molecular targets for the therapeutic intervention of these SCCs. We observed that combined blockade of Akt and p38 kinases-dependent signaling pathways in CsA-promoted human epidermoid carcinoma A431 xenograft tumors abrogated their growth by more than 90%. This diminution in tumor growth was accompanied by a significant decrease in proliferation and an increase in apoptosis. The residual tumors following the combined treatment with Akt inhibitor triciribine and p38 inhibitors SB-203580 showed significantly diminished expression of phosphorylated Akt and p38 and these tumors were less invasive and highly differentiated. Diminished tumor invasiveness was associated with the reduced epithelial-mesenchymal transition as ascertained by the enhanced E-cadherin and reduced vimentin and N-cadherin expression. Consistently, these tumors also manifested reduced MMP-2/9. The decreased p-Akt expression was accompanied by a significant reduction in p-mTOR. These data provide first important combinatorial pharmacological approach to block the pathogenesis of CsA-induced highly aggressive cutaneous neoplasm in OTRs.

Pharmacological inhibition of NADPH oxidase protects against cisplatin induced nephrotoxicity in mice by two step mechanism.

Science.gov (United States)

Wang, Yimin; Luo, Xiao; Pan, Hao; Huang, Wei; Wang, Xueping; Wen, Huali; Shen, Kezhen; Jin, Baiye

2015-09-01

Cisplatin induced nephrotoxicity is primarily caused by ROS (Reactive Oxygen Species) induced proximal tubular cell death. NADPH oxidase is major source of ROS production by cisplatin. Here, we reported that pharmacological inhibition of NADPH oxidase by acetovanillone (obtained from medicinal herb Picrorhiza kurroa) led to reduced cisplatin nephrotoxicity in mice. In this study we used various molecular biology and biochemistry methods a clinically relevant model of nephropathy, induced by an important chemotherapeutic drug cisplatin. Cisplatin-induced nephrotoxicity was evident by histological damage from loss of the tubular structure. The damage was also marked by the increase in blood urea nitrogen, creatinine, protein nitration as well as cell death markers such as caspase 3/7 activity and DNA fragmentation. Tubular cell death by cisplatin led to pro-inflammatory response by production of TNFα and IL1β followed by leukocyte/neutrophil infiltration which resulted in new wave of ROS involving more NADPH oxidases. Cisplatin-induced markers of kidney damage such as oxidative stress, cell death, inflammatory cytokine production and nephrotoxicity were attenuated by acetovanillone. In addition to that, acetovanillone enhanced cancer cell killing efficacy of cisplatin. Thus, pharmacological inhibition of NADPH oxidase can be protective for cisplatin-induced nephrotoxicity in mice. Copyright © 2015. Published by Elsevier Ltd.

Molecular Pharmacology of CXCR4 inhibition

DEFF Research Database (Denmark)

Steen, Anne; Rosenkilde, Mette Marie

2012-01-01

pharmacology of well-known CXCR4 antagonists in order to augment the potency and affinity and to increase the specificity of future CXCR4-targeting compounds. In this chapter, binding modes of CXCR4 antagonists that have been shown to mobilize stem cells are discussed. In addition, comparisons between results...

GSK3β inhibition promotes synaptogenesis in Drosophila and mammalian neurons.

Directory of Open Access Journals (Sweden)

Germán Cuesto

Full Text Available The PI3K-dependent activation of AKT results in the inhibition of GSK3β in most signaling pathways. These kinases regulate multiple neuronal processes including the control of synapse number as shown for Drosophila and rodents. Alzheimer disease's patients exhibit high levels of circulating GSK3β and, consequently, pharmacological strategies based on GSK3β antagonists have been designed. The approach, however, has yielded inconclusive results so far. Here, we carried out a comparative study in Drosophila and rats addressing the role of GSK3β in synaptogenesis. In flies, the genetic inhibition of the shaggy-encoded GSK3β increases the number of synapses, while its upregulation leads to synapse loss. Likewise, in three weeks cultured rat hippocampal neurons, the pharmacological inhibition of GSK3β increases synapse density and Synapsin expression. However, experiments on younger cultures (12 days yielded an opposite effect, a reduction of synapse density. This unexpected finding seems to unveil an age- and dosage-dependent differential response of mammalian neurons to the stimulation/inhibition of GSK3β, a feature that must be considered in the context of human adult neurogenesis and pharmacological treatments for Alzheimer's disease based on GSK3β antagonists.

Light adaptation alters the source of inhibition to the mouse retinal OFF pathway

Science.gov (United States)

Mazade, Reece E.

2013-01-01

Sensory systems must avoid saturation to encode a wide range of stimulus intensities. One way the retina accomplishes this is by using both dim-light-sensing rod and bright-light-sensing cone photoreceptor circuits. OFF cone bipolar cells are a key point in this process, as they receive both excitatory input from cones and inhibitory input from AII amacrine cells via the rod pathway. However, in addition to AII amacrine cell input, other inhibitory inputs from cone pathways also modulate OFF cone bipolar cell light signals. It is unknown how these inhibitory inputs to OFF cone bipolar cells change when switching between rod and cone pathways or whether all OFF cone bipolar cells receive rod pathway input. We found that one group of OFF cone bipolar cells (types 1, 2, and 4) receive rod-mediated inhibitory inputs that likely come from the rod-AII amacrine cell pathway, while another group of OFF cone bipolar cells (type 3) do not. In both cases, dark-adapted rod-dominant light responses showed a significant contribution of glycinergic inhibition, which decreased with light adaptation and was, surprisingly, compensated by an increase in GABAergic inhibition. As GABAergic input has distinct timing and spatial spread from glycinergic input, a shift from glycinergic to GABAergic inhibition could significantly alter OFF cone bipolar cell signaling to downstream OFF ganglion cells. Larger GABAergic input could reflect an adjustment of OFF bipolar cell spatial inhibition, which may be one mechanism that contributes to retinal spatial sensitivity in the light. PMID:23926034

N-end rule pathway inhibition assists colon tumor regression via necroptosis

Directory of Open Access Journals (Sweden)

Pritha Agarwalla

2016-01-01

Full Text Available Recent study has shown that N-end rule pathway, an ubiquitin dependent proteolytic system, counteracts cell death by degrading many antisurvival protein fragments like BCLxL, BRCA1, RIPK1, etc. Inhibition of the N-end rule pathway can lead to metabolic stabilization of proapoptotic protein fragments like RIPK1, thereby sensitizing cells to programmed cell death. Receptor interacting serine-threonine protein kinase-1 (RIPK1 is one of the upstream regulators of programmed necrosis known as necroptosis. Necroptosis is particularly gaining attention of cancer biologists as it provides an alternate therapeutic modality to kill cancer cells, which often evolve multiple strategies to circumvent growth inhibition by apoptosis. Utilizing the over expression of biotin receptor in cancer cells, herein, we report that coadministration of synthetic hetero-bivalent N-end rule inhibitor RFC11 and anticancer drug shikonin solubilized in a stable biotin receptor-targeted liposome exhibited significant synergistic antitumor effect in both subcutaneous and orthotopic mouse colon tumor model through induction of necroptosis with distinctive upregulation of RIPK1. Besides developing a newly targeted formulation for necroptosis induction, this report is the first in vivo evidence demonstrating that potent inhibition of N-end rule pathway can enhance therapeutic efficacy of conventional chemotherapeutics.

Combined MEK and ERK inhibition overcomes therapy-mediated pathway reactivation in RAS mutant tumors.

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Mark Merchant

Full Text Available Mitogen-activated protein kinase (MAPK pathway dysregulation is implicated in >30% of all cancers, rationalizing the development of RAF, MEK and ERK inhibitors. While BRAF and MEK inhibitors improve BRAF mutant melanoma patient outcomes, these inhibitors had limited success in other MAPK dysregulated tumors, with insufficient pathway suppression and likely pathway reactivation. In this study we show that inhibition of either MEK or ERK alone only transiently inhibits the MAPK pathway due to feedback reactivation. Simultaneous targeting of both MEK and ERK nodes results in deeper and more durable suppression of MAPK signaling that is not achievable with any dose of single agent, in tumors where feedback reactivation occurs. Strikingly, combined MEK and ERK inhibition is synergistic in RAS mutant models but only additive in BRAF mutant models where the RAF complex is dissociated from RAS and thus feedback productivity is disabled. We discovered that pathway reactivation in RAS mutant models occurs at the level of CRAF with combination treatment resulting in a markedly more active pool of CRAF. However, distinct from single node targeting, combining MEK and ERK inhibitor treatment effectively blocks the downstream signaling as assessed by transcriptional signatures and phospho-p90RSK. Importantly, these data reveal that MAPK pathway inhibitors whose activity is attenuated due to feedback reactivation can be rescued with sufficient inhibition by using a combination of MEK and ERK inhibitors. The MEK and ERK combination significantly suppresses MAPK pathway output and tumor growth in vivo to a greater extent than the maximum tolerated doses of single agents, and results in improved anti-tumor activity in multiple xenografts as well as in two Kras mutant genetically engineered mouse (GEM models. Collectively, these data demonstrate that combined MEK and ERK inhibition is functionally unique, yielding greater than additive anti-tumor effects and

Inhibition of CD38/Cyclic ADP-ribose Pathway Protects Rats against Ropivacaine-induced Convulsion

Directory of Open Access Journals (Sweden)

Yu Zou

2017-01-01

Conclusions: The CD38/cADPR pathway is activated in ropivacaine-induced convulsion. Inhibiting this pathway alleviates ropivacaine-induced convulsion and protects the brain from apoptosis and oxidative stress.

NAD+ salvage pathway in cancer metabolism and therapy.

Science.gov (United States)

Kennedy, Barry E; Sharif, Tanveer; Martell, Emma; Dai, Cathleen; Kim, Youra; Lee, Patrick W K; Gujar, Shashi A

2016-12-01

Nicotinamide adenine dinucleotide (NAD + ) is an essential coenzyme for various physiological processes including energy metabolism, DNA repair, cell growth, and cell death. Many of these pathways are typically dysregulated in cancer cells, making NAD + an intriguing target for cancer therapeutics. NAD + is mainly synthesized by the NAD + salvage pathway in cancer cells, and not surprisingly, the pharmacological targeting of the NAD + salvage pathway causes cancer cell cytotoxicity in vitro and in vivo. Several studies have described the precise consequences of NAD + depletion on cancer biology, and have demonstrated that NAD+ depletion results in depletion of energy levels through lowered rates of glycolysis, reduced citric acid cycle activity, and decreased oxidative phosphorylation. Additionally, depletion of NAD + causes sensitization of cancer cells to oxidative damage by disruption of the anti-oxidant defense system, decreased cell proliferation, and initiation of cell death through manipulation of cell signaling pathways (e.g., SIRT1 and p53). Recently, studies have explored the effect of well-known cancer therapeutics in combination with pharmacological depletion of NAD + levels, and found in many cases a synergistic effect on cancer cell cytotoxicity. In this context, we will discuss the effects of NAD + salvage pathway inhibition on cancer cell biology and provide insight on this pathway as a novel anti-cancer therapeutic target. Copyright © 2016 Elsevier Ltd. All rights reserved.

Inhibition of the isoprenoid biosynthesis pathway; detection of intermediates by UPLC-MS/MS

NARCIS (Netherlands)

Henneman, Linda; van Cruchten, Arno G.; Kulik, Willem; Waterham, Hans R.

2011-01-01

The isoprenoid biosynthesis pathway provides the cell with a variety of compounds which are involved in multiple cellular processes. Inhibition of this pathway with statins and bisphosphonates is widely applied in the treatment of hypercholesterolemia and metabolic bone disease, respectively. In

Endocytic pathways mediating oligomeric Aβ42 neurotoxicity

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Laxton Kevin

2010-05-01

Full Text Available Abstract Background One pathological hallmark of Alzheimer's disease (AD is amyloid plaques, composed primarily of amyloid-β peptide (Aβ. Over-production or diminished clearance of the 42 amino acid form of Aβ (Aβ42 in the brain leads to accumulation of soluble Aβ and plaque formation. Soluble oligomeric Aβ (oAβ has recently emerged to be as a likely proximal cause of AD. Results Here we demonstrate that endocytosis is critical in mediating oAβ42-induced neurotoxicity and intraneuronal accumulation of Aβ. Inhibition of clathrin function either with a pharmacological inhibitor, knock-down of clathrin heavy chain expression, or expression of the dominant-negative mutant of clathrin-assembly protein AP180 did not block oAβ42-induced neurotoxicity or intraneuronal accumulation of Aβ. However, inhibition of dynamin and RhoA by expression of dominant negative mutants reduced neurotoxicity and intraneuronal Aβ accumulation. Pharmacologic inhibition of the dynamin-mediated endocytic pathway by genistein also reduced neurotoxicity. Conclusions These data suggest that dynamin-mediated and RhoA-regulated endocytosis are integral steps for oligomeric Aβ42-induced neurotoxicity and intraneuronal Aβ accumulation.

Pharmacological activation of the EDA/EDAR signaling pathway restores salivary gland function following radiation-induced damage.

Directory of Open Access Journals (Sweden)

Grace Hill

Full Text Available Radiotherapy of head and neck cancers often results in collateral damage to adjacent salivary glands associated with clinically significant hyposalivation and xerostomia. Due to the reduced capacity of salivary glands to regenerate, hyposalivation is treated by substitution with artificial saliva, rather than through functional restoration of the glands. During embryogenesis, the ectodysplasin/ectodysplasin receptor (EDA/EDAR signaling pathway is a critical element in the development and growth of salivary glands. We have assessed the effects of pharmacological activation of this pathway in a mouse model of radiation-induced salivary gland dysfunction. We report that post-irradiation administration of an EDAR-agonist monoclonal antibody (mAbEDAR1 normalizes function of radiation damaged adult salivary glands as determined by stimulated salivary flow rates. In addition, salivary gland structure and homeostasis is restored to pre-irradiation levels. These results suggest that transient activation of pathways involved in salivary gland development could facilitate regeneration and restoration of function following damage.

Negative control of the HGF/c-MET pathway by TGF-β: a new look at the regulation of stemness in glioblastoma.

Science.gov (United States)

Papa, Eleanna; Weller, Michael; Weiss, Tobias; Ventura, Elisa; Burghardt, Isabel; Szabó, Emese

2017-12-13

Multiple target inhibition has gained considerable interest in combating drug resistance in glioblastoma, however, understanding the molecular mechanisms of crosstalk between signaling pathways and predicting responses of cancer cells to targeted interventions has remained challenging. Despite the significant role attributed to transforming growth factor (TGF)-β family and hepatocyte growth factor (HGF)/c-MET signaling in glioblastoma pathogenesis, their functional interactions have not been well characterized. Using genetic and pharmacological approaches to stimulate or antagonize the TGF-β pathway in human glioma-initiating cells (GIC), we observed that TGF-β exerts an inhibitory effect on c-MET phosphorylation. Inhibition of either mitogen-activated protein kinase (MAPK)/ extracellular signal-regulated kinase (ERK) or phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB/AKT) signaling pathway attenuated this effect. A comparison of c-MET-driven and c-MET independent GIC models revealed that TGF-β inhibits stemness in GIC at least in part via its negative regulation of c-MET activity, suggesting that stem cell (SC) maintenance may be controlled by the balance between these two oncogenic pathways. Importantly, immunohistochemical analyses of human glioblastoma and ex vivo single-cell gene expression profiling of TGF-β and HGF confirm the negative interaction between both pathways. These novel insights into the crosstalk of two major pathogenic pathways in glioblastoma may explain some of the disappointing results when targeting either pathway alone in human glioblastoma patients and inform on potential future designs on targeted pharmacological or genetic intervention.

Hedgehog Pathway Inhibition Radiosensitizes Non-Small Cell Lung Cancers

Energy Technology Data Exchange (ETDEWEB)

Zeng, Jing; Aziz, Khaled; Chettiar, Sivarajan T. [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Aftab, Blake T. [Department of Medical Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Armour, Michael; Gajula, Rajendra; Gandhi, Nishant; Salih, Tarek; Herman, Joseph M.; Wong, John [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Rudin, Charles M. [Department of Medical Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Tran, Phuoc T. [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Department of Medical Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Hales, Russell K., E-mail: rhales1@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States)

2013-05-01

Purpose: Despite improvements in chemoradiation, local control remains a major clinical problem in locally advanced non-small cell lung cancer. The Hedgehog pathway has been implicated in tumor recurrence by promoting survival of tumorigenic precursors and through effects on tumor-associated stroma. Whether Hedgehog inhibition can affect radiation efficacy in vivo has not been reported. Methods and Materials: We evaluated the effects of a targeted Hedgehog inhibitor (HhAntag) and radiation on clonogenic survival of human non-small cell lung cancer lines in vitro. Using an A549 cell line xenograft model, we examined tumor growth, proliferation, apoptosis, and gene expression changes after concomitant HhAntag and radiation. In a transgenic mouse model of Kras{sup G12D}-induced and Twist1-induced lung adenocarcinoma, we assessed tumor response to radiation and HhAntag by serial micro-computed tomography (CT) scanning. Results: In 4 human lung cancer lines in vitro, HhAntag showed little or no effect on radiosensitivity. By contrast, in both the human tumor xenograft and murine inducible transgenic models, HhAntag enhanced radiation efficacy and delayed tumor growth. By use of the human xenograft model to differentiate tumor and stromal effects, mouse stromal cells, but not human tumor cells, showed significant and consistent downregulation of Hedgehog pathway gene expression. This was associated with increased tumor cell apoptosis. Conclusions: Targeted Hedgehog pathway inhibition can increase in vivo radiation efficacy in lung cancer preclinical models. This effect is associated with pathway suppression in tumor-associated stroma. These data support clinical testing of Hedgehog inhibitors as a component of multimodality therapy for locally advanced non-small cell lung cancer.

Pharmacological or genetic inhibition of LDHA reverses tumor progression of pediatric osteosarcoma.

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Gao, Shan; Tu, Dan-Na; Li, Heng; Jiang, Jian-Xin; Cao, Xin; You, Jin-Bin; Zhou, Xiao-Qin

2016-07-01

Reprogrammed energy metabolism is an emerging hallmark of cancer. Lactate dehydrogenase A (LDHA), a key enzyme involved in anaerobic glycolysis, is frequently deregulated in human malignancies. However, limited knowledge is known about its roles in the progression of osteosarcoma (OS). In this study, we found that LDHA is commonly upregulated in four OS cell lines compared with the normal osteoblast cells (hFOB1.19). Treatment with FX11, a specific inhibitor of LDHA, significantly reduced LDHA activity, and inhibited cell proliferation and invasive potential in a dose dependent manner. Genetic silencing of LDHA resulted in a decreased lactate level in the culture medium, reduced cell viability and decreased cell invasion ability. Meanwhile, silencing of LDHA also compromised tumorigenesis in vivo. Furthermore, knockdown of LDHA remarkably reduced extracellular acidification rate (ECAR) as well as glucose consumption. In the presence of 2-DG, a glycolysis inhibitor, LDHA-mediated cell proliferation and invasion were completely blocked, indicating the oncogenic activities of LDHA may dependent on Warburg effect. Finally, pharmacological inhibition of c-Myc or HIF1α significantly attenuated LDHA expression. Taken together, upregulated LDHA facilitates tumor progression of OS and might be a potential target for OS treatment. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Dioscin inhibits colon tumor growth and tumor angiogenesis through regulating VEGFR2 and AKT/MAPK signaling pathways

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Tong, Qingyi [Regenerative Medicine Research Center, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041 (China); Qing, Yong, E-mail: qingyongxy@yahoo.co.jp [Department of Pharmacology, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan 610041 (China); Wu, Yang [State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041 (China); Hu, Xiaojuan; Jiang, Lei [Department of Pharmacology, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan 610041 (China); Wu, Xiaohua, E-mail: wuxh@scu.edu.cn [Regenerative Medicine Research Center, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041 (China)

2014-12-01

Dioscin has shown cytotoxicity against cancer cells, but its in vivo effects and the mechanisms have not elucidated yet. The purpose of the current study was to assess the antitumor effects and the molecular mechanisms of dioscin. We showed that dioscin could inhibit tumor growth in vivo and has no toxicity at the test condition. The growth suppression was accompanied by obvious blood vessel decrease within solid tumors. We also found dioscin treatment inhibited the proliferation of cancer and endothelial cell lines, and most sensitive to primary cultured human umbilical vein endothelial cells (HUVECs). What's more, analysis of HUVECs migration, invasion, and tube formation exhibited that dioscin has significantly inhibitive effects to these actions. Further analysis of blood vessel formation in the matrigel plugs indicated that dioscin could inhibit VEGF-induced blood vessel formation in vivo. We also identified that dioscin could suppress the downstream protein kinases of VEGFR2, including Src, FAK, AKT and Erk1/2, accompanied by the increase of phosphorylated P38MAPK. The results potently suggest that dioscin may be a potential anticancer drug, which efficiently inhibits angiogenesis induced by VEGFR2 signaling pathway as well as AKT/MAPK pathways. - Highlights: • Dioscin inhibits tumor growth in vivo and does not exhibit any toxicity. • Dioscin inhibits angiogenesis within solid tumors. • Dioscin inhibits the proliferation, migration, invasion, and tube formation of HUVECs. • Dioscin inhibits VEGF–induced blood vessel formation in vivo. • Dioscin inhibits VEGFR2 signaling pathway as well as AKT/MAPK pathway.

SD118-Xanthocillin X (1, a Novel Marine Agent Extracted from Penicillium commune, Induces Autophagy through the Inhibition of the MEK/ERK Pathway

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Caiguo Huang

2012-06-01

Full Text Available A compound named SD118-xanthocillin X (1 (C₁₈H₁₂N₂O₂, isolated from Penicillium commune in a deep-sea sediment sample, has been shown to inhibit the growth of several cancer cell lines in vitro. In the present study, we employed a growth inhibition assay and apoptotic analysis to identify the biological effect and detailed mechanism of SD118-xanthocillin X (1 in human hepatocellular carcinoma (HepG2 cells. SD118-xanthocillin X (1 demonstrated a concentration-dependent inhibitory effect on the growth of HepG2 cells and caused slight cellular apoptosis and significantly induced autophagy. Autophagy was detected as early as 12 h by the conversion of microtubule-associated protein 1 light chain 3 (LC3-I to LC3-II, following cleavage and lipid addition to LC3-I. The pharmacological autophagy inhibitor 3-methyladenine largely attenuates the growth inhibition and autophagic effect of SD118-xanthocillin X (1 in HepG2 cells. Our data also indicated that the autophagic effect of SD118-xanthocillin X (1 occurs via the down-regulation of the MEK/ERK signaling pathway and the up-regulated class III PI3K/Beclin 1 signaling pathway.

A network pharmacology approach to investigate the pharmacological effects of Guizhi Fuling Wan on uterine fibroids.

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Zeng, Liuting; Yang, Kailin; Liu, Huiping; Zhang, Guomin

2017-11-01

To investigate the pharmacological mechanism of Guizhi Fuling Wan (GFW) in the treatment of uterine fibroids, a network pharmacology approach was used. Information on GFW compounds was collected from traditional Chinese medicine (TCM) databases, and input into PharmMapper to identify the compound targets. Genes associated with uterine fibroids genes were then obtained from the GeneCards and Online Mendelian Inheritance in Man databases. The interaction data of the targets and other human proteins was also collected from the STRING and IntAct databases. The target data were input into the Database for Annotation, Visualization and Integrated Discovery for gene ontology (GO) and pathway enrichment analyses. Networks of the above information were constructed and analyzed using Cytoscape. The following networks were compiled: A compound-compound target network of GFW; a herb-compound target-uterine fibroids target network of GWF; and a compound target-uterine fibroids target-other human proteins protein-protein interaction network, which were subjected to GO and pathway enrichment analyses. According to this approach, a number of novel signaling pathways and biological processes underlying the effects of GFW on uterine fibroids were identified, including the negative regulation of smooth muscle cell proliferation, apoptosis, and the Ras, wingless-type, epidermal growth factor and insulin-like growth factor-1 signaling pathways. This network pharmacology approach may aid the systematical study of herbal formulae and make TCM drug discovery more predictable.

A novel systems pharmacology platform to dissect action mechanisms of traditional Chinese medicines for bovine viral diarrhea disease.

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Zheng, Chunli; Pei, Tianli; Huang, Chao; Chen, Xuetong; Bai, Yaofei; Xue, Jun; Wu, Ziyin; Mu, Jiexin; Li, Yan; Wang, Yonghua

2016-10-30

Due to the large direct and indirect productivity losses in the livestock industry caused by bovine viral diarrhea (BVD) and the lack of effective pharmacological therapies, developing an efficient treatment is extremely urgent. Traditional Chinese medicines (TCMs) that simultaneously address multiple targets have been proven to be effective therapies for BVD. However, the potential molecular action mechanisms of TCMs have not yet been systematically explored. In this work, take the example of a herbal remedy Huangqin Zhizi (HQZZ) for BVD treatment in China, a systems pharmacology approach combining with the pharmacokinetics and pharmacodynamics evaluation was developed to screen out the active ingredients, predict the targets and analyze the networks and pathways. Results show that 212 active compounds were identified. Utilizing these lead compounds as probes, we predicted 122 BVD related-targets. And in vitro experiments were conducted to evaluate the reliability of some vital active compounds and targets. Network and pathway analysis displayed that HQZZ was effective in the treatment of BVD by inhibiting inflammation, enhancing immune responses in hosts toward virus infection. In summary, the analysis of the complete profile of the pharmacological activities, as well as the elucidation of targets, networks and pathways can further elucidate the underlying anti-inflammatory, antiviral and immune regulation mechanisms of HQZZ against BVD. Copyright © 2016 Elsevier B.V. All rights reserved.

A novel compound DT-010 protects against doxorubicin-induced cardiotoxicity in zebrafish and H9c2 cells by inhibiting reactive oxygen species-mediated apoptotic and autophagic pathways.

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Tang, Fan; Zhou, Xinhua; Wang, Liang; Shan, Luchen; Li, Chuwen; Zhou, Hefeng; Lee, Simon Ming-Yuen; Hoi, Maggie Pui-Man

2018-02-05

Doxorubicin (Dox) is an effective anti-cancer agent but limited by its cardiotoxicity, thus the search for pharmacological agents for enhancing anti-cancer activities and protecting against cardiotoxicity has been a subject of great interest. We have previously reported the synergistic anti-cancer effects of a novel compound DT-010. In the present study, we further investigated the cardioprotective effects of DT-010 in zebrafish embryos in vivo and the molecular underlying mechanisms in H9c2 cardiomyocytes in vitro. We showed that DT-010 prevented the Dox-induced morphological distortions in the zebrafish heart and the associated cardiac impairments, and especially improved ventricular functions. By using H9c2 cells model, we showed that DT-010 directly inhibited the generation of reactive oxygen species by Dox and protected cell death and cellular damage. We further observed that DT-010 protected against Dox-induced myocardiopathy via inhibiting downstream molecular pathways in response to oxidative stress, including reactive oxygen species-mediated MAPK signaling pathways ERK and JNK, and apoptotic pathways involving the activation of caspase 3, caspase 7, and PARP signaling. Recent studies also suggest the importance of alterations in cardiac autophagy in Dox cardiotoxicity. We further showed that DT-010 could inhibit the induction of autophagosomes formation by Dox via regulating the upstream Akt/AMPK/mTOR signaling. Since Dox-induced cardiotoxicity is multifactorial, our results suggest that multi-functional agent such as DT-010 might be an effective therapeutic agent for combating cardiotoxicity associated with chemotherapeutic agents such as Dox. Copyright © 2017 Elsevier B.V. All rights reserved.

Inhibition of phospholipaseD2 increases hypoxia-induced human colon cancer cell apoptosis through inactivating of the PI3K/AKT signaling pathway.

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Liu, Maoxi; Fu, Zhongxue; Wu, Xingye; Du, Kunli; Zhang, Shouru; Zeng, Li

2016-05-01

Hypoxia is a common feature of solid tumor, and is a direct stress that triggers apoptosis in many human cell types. As one of solid cancer, hypoxia exists in the whole course of colon cancer occurrence and progression. Our previous studies shown that hypoxia induce high expression of phospholipase D2 (PLD2) and survivin in colon cancer cells. However, the correlation between PLD2 and survivin in hypoxic colon cancer cells remains unknown. In this study, we observed significantly elevated PLD2 and survivin expression levels in colon cancer tissues and cells. This is a positive correlation between of them, and co-expression of PLD2 and survivin has a positive correlation with the clinicpatholic features including tumor size, TNM stage, and lymph node metastasis. We also found that hypoxia induced the activity of PLD increased significant mainly caused by PLD2 in colon cancer cells. However, inhibition the activity of PLD2 induced by hypoxia promotes the apoptosis of human colon cancer cells, as well as decreased the expression of apoptosis markers including survivin and bcl2. Moreover, the pharmacological inhibition of PI3K/AKT supported the hypothesis that promotes the apoptosis of hypoxic colon cancer cells by PLD2 activity inhibition may through inactivation of the PI3K/AKT signaling pathway. Furthermore, interference the PLD2 gene expression leaded to the apoptosis of hypoxic colon cancer cells increased and also decreased the expression level of survivin and bcl2 may through inactivation of PI3K/AKT signaling pathway. These results indicated that PLD2 play antiapoptotic role in colon cancer under hypoxic conditions, inhibition of the activity, or interference of PLD2 gene expression will benefit for the treatment of colon cancer patients.

Regorafenib inhibited gastric cancer cells growth and invasion via CXCR4 activated Wnt pathway.

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Lin, Xiao-Lin; Xu, Qi; Tang, Lei; Sun, Li; Han, Ting; Wang, Li-Wei; Xiao, Xiu-Ying

2017-01-01

Regorafenib is an oral small-molecule multi kinase inhibitor. Recently, several clinical trials have revealed that regorafenib has an anti-tumor activity in gastric cancer. However, only part of patients benefit from regorafenib, and the mechanisms of regorafenib's anti-tumor effect need further demonstrating. In this study, we would assess the potential anti-tumor effects and the underlying mechanisms of regorafenib in gastric cancer cells, and explore novel biomarkers for patients selecting of regorafenib. The anti-tumor effects of regorafenib on gastric cancer cells were analyzed via cell proliferation and invasion. The underlying mechanisms were demonstrated using molecular biology techniques. We found that regorafenib inhibited cell proliferation and invasion at the concentration of 20μmol/L and in a dose dependent manner. The anti-tumor effects of regorafenib related to the decreased expression of CXCR4, and elevated expression and activation of CXCR4 could reverse the inhibition effect of regorafenib on gastric cancer cells. Further studies revealed that regorafenib reduced the transcriptional activity of Wnt/β-Catenin pathway and led to decreased expression of Wnt pathway target genes, while overexpression and activation of CXCR4 could attenuate the inhibition effect of regorafenib on Wnt/β-Catenin pathway. Our findings demonstrated that regorafenib effectively inhibited cell proliferation and invasion of gastric cancer cells via decreasing the expression of CXCR4 and further reducing the transcriptional activity of Wnt/β-Catenin pathway.

Acrolein increases 5-lipoxygenase expression in murine macrophages through activation of ERK pathway.

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Kim, Chae E; Lee, Seung J; Seo, Kyo W; Park, Hye M; Yun, Jung W; Bae, Jin U; Bae, Sun S; Kim, Chi D

2010-05-15

Episodic exposure to acrolein-rich pollutants has been linked to acute myocardial infarction, and 5-lipoxygenase (5-LO) is involved in the production of matrix metalloproteinase-9 (MMP-9), which destabilizes atherosclerotic plaques. Thus, the present study determined the effect of acrolein on 5-LO/leukotriene B(4) (LTB(4)) production in murine macrophages. Stimulation of J774A.1 cells with acrolein led to increased LTB(4) production in association with increased 5-LO expression. Acrolein-evoked 5-LO expression was blocked by pharmacological inhibition of the ERK pathway, but not by inhibitors for JNK and p38 MAPK pathways. In line with these results, acrolein exclusively increased the phosphorylation of ERK among these MAPK, suggesting a role for the ERK pathway in acrolein-induced 5-LO expression with subsequent production of LTB(4). Among the receptor tyrosine kinases including epidermal growth factor receptor (EGFR) and platelet derived growth factor receptor (PDGFR), acrolein-evoked ERK phosphorylation was attenuated by AG1478, an EGFR inhibitor, but not by AG1295, a PDGFR inhibitor. In addition, acrolein-evoked 5-LO expression was also inhibited by inhibition of EGFR pathway, but not by inhibition of PDGFR pathway. These observations suggest that acrolein has a profound effect on the 5-LO pathway via an EGFR-mediated activation of ERK pathway, leading to acute ischemic syndromes through the generation of LTB(4), subsequent MMP-9 production and plaque rupture.

Acrolein increases 5-lipoxygenase expression in murine macrophages through activation of ERK pathway

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Kim, Chae E.; Lee, Seung J.; Seo, Kyo W.; Park, Hye M.; Yun, Jung W.; Bae, Jin U.; Bae, Sun S.; Kim, Chi D.

2010-01-01

Episodic exposure to acrolein-rich pollutants has been linked to acute myocardial infarction, and 5-lipoxygenase (5-LO) is involved in the production of matrix metalloproteinase-9 (MMP-9), which destabilizes atherosclerotic plaques. Thus, the present study determined the effect of acrolein on 5-LO/leukotriene B 4 (LTB 4 ) production in murine macrophages. Stimulation of J774A.1 cells with acrolein led to increased LTB 4 production in association with increased 5-LO expression. Acrolein-evoked 5-LO expression was blocked by pharmacological inhibition of the ERK pathway, but not by inhibitors for JNK and p38 MAPK pathways. In line with these results, acrolein exclusively increased the phosphorylation of ERK among these MAPK, suggesting a role for the ERK pathway in acrolein-induced 5-LO expression with subsequent production of LTB 4 . Among the receptor tyrosine kinases including epidermal growth factor receptor (EGFR) and platelet derived growth factor receptor (PDGFR), acrolein-evoked ERK phosphorylation was attenuated by AG1478, an EGFR inhibitor, but not by AG1295, a PDGFR inhibitor. In addition, acrolein-evoked 5-LO expression was also inhibited by inhibition of EGFR pathway, but not by inhibition of PDGFR pathway. These observations suggest that acrolein has a profound effect on the 5-LO pathway via an EGFR-mediated activation of ERK pathway, leading to acute ischemic syndromes through the generation of LTB 4 , subsequent MMP-9 production and plaque rupture.

Three cardiovirus Leader proteins equivalently inhibit four different nucleocytoplasmic trafficking pathways

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Ciomperlik, Jessica J. [Institute for Molecular Virology, and Department of Biochemistry, University of Wisconsin-Madison, Madison, WI (United States); Basta, Holly A. [Department of Biology, Rocky Mountain College, Billings, MT (United States); Palmenberg, Ann C., E-mail: acpalmen@wisc.edu [Institute for Molecular Virology, and Department of Biochemistry, University of Wisconsin-Madison, Madison, WI (United States)

2015-10-15

Cardiovirus infections inhibit nucleocytoplasmic trafficking by Leader protein-induced phosphorylation of Phe/Gly-containing nucleoporins (Nups). Recombinant Leader from encephalomyocarditis virus, Theiler's murine encephalomyelitis virus and Saffold virus target the same subset of Nups, including Nup62 and Nup98, but not Nup50. Reporter cell lines with fluorescence mCherry markers for M9, RS and classical SV40 import pathways, as well as the Crm1-mediated export pathway, all responded to transfection with the full panel of Leader proteins, showing consequent cessation of path-specific active import/export. For this to happen, the Nups had to be presented in the context of intact nuclear pores and exposed to cytoplasmic extracts. The Leader phosphorylation cascade was not effective against recombinant Nup proteins. The findings support a model of Leader-dependent Nup phosphorylation with the purpose of disrupting Nup-transportin interactions. - Highlights: • Nup98, but not Nup50 becomes phosphorylated by cardiovirus Leader protein-dependent mechanisms. • At least four independent nucleocytoplasmic trafficking pathways are inhibited by this process. • Nups must be presented in a nuclear pore context for Leader-directed phosphorylation. • Leader, by itself, does not cause activation of cellular kinases.

Three cardiovirus Leader proteins equivalently inhibit four different nucleocytoplasmic trafficking pathways

International Nuclear Information System (INIS)

Ciomperlik, Jessica J.; Basta, Holly A.; Palmenberg, Ann C.

2015-01-01

Cardiovirus infections inhibit nucleocytoplasmic trafficking by Leader protein-induced phosphorylation of Phe/Gly-containing nucleoporins (Nups). Recombinant Leader from encephalomyocarditis virus, Theiler's murine encephalomyelitis virus and Saffold virus target the same subset of Nups, including Nup62 and Nup98, but not Nup50. Reporter cell lines with fluorescence mCherry markers for M9, RS and classical SV40 import pathways, as well as the Crm1-mediated export pathway, all responded to transfection with the full panel of Leader proteins, showing consequent cessation of path-specific active import/export. For this to happen, the Nups had to be presented in the context of intact nuclear pores and exposed to cytoplasmic extracts. The Leader phosphorylation cascade was not effective against recombinant Nup proteins. The findings support a model of Leader-dependent Nup phosphorylation with the purpose of disrupting Nup-transportin interactions. - Highlights: • Nup98, but not Nup50 becomes phosphorylated by cardiovirus Leader protein-dependent mechanisms. • At least four independent nucleocytoplasmic trafficking pathways are inhibited by this process. • Nups must be presented in a nuclear pore context for Leader-directed phosphorylation. • Leader, by itself, does not cause activation of cellular kinases

Inhibition of the Unfolded Protein Response Mechanism Prevents Cardiac Fibrosis.

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Jody Groenendyk

Full Text Available Cardiac fibrosis attributed to excessive deposition of extracellular matrix proteins is a major cause of heart failure and death. Cardiac fibrosis is extremely difficult and challenging to treat in a clinical setting due to lack of understanding of molecular mechanisms leading to cardiac fibrosis and effective anti-fibrotic therapies. The objective in this study was to examine whether unfolded protein response (UPR pathway mediates cardiac fibrosis and whether a pharmacological intervention to modulate UPR can prevent cardiac fibrosis and preserve heart function.We demonstrate here that the mechanism leading to development of fibrosis in a mouse with increased expression of calreticulin, a model of heart failure, stems from impairment of endoplasmic reticulum (ER homeostasis, transient activation of the unfolded protein response (UPR pathway and stimulation of the TGFβ1/Smad2/3 signaling pathway. Remarkably, sustained pharmacologic inhibition of the UPR pathway by tauroursodeoxycholic acid (TUDCA is sufficient to prevent cardiac fibrosis, and improved exercise tolerance.We show that the mechanism leading to development of fibrosis in a mouse model of heart failure stems from transient activation of UPR pathway leading to persistent remodelling of cardiac tissue. Blocking the activation of the transiently activated UPR pathway by TUDCA prevented cardiac fibrosis, and improved prognosis. These findings offer a window for additional interventions that can preserve heart function.

Inhibition of the classical pathway of the complement system by saliva of Amblyomma cajennense (Acari: Ixodidae).

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Franco, Paula F; Silva, Naylene C S; Fazito do Vale, Vladimir; Abreu, Jéssica F; Santos, Vânia C; Gontijo, Nelder F; Valenzuela, Jesus G; Pereira, Marcos H; Sant'Anna, Mauricio R V; Gomes, Alessandra P S; Araujo, Ricardo N

2016-05-01

Inhibition of the complement system during and after haematophagy is of utmost importance for tick success in feeding and tick development. The role of such inhibition is to minimise damage to the intestinal epithelium as well as avoiding inflammation and opsonisation of salivary molecules at the bite site. Despite its importance, the salivary anti-complement activity has been characterised only in species belonging to the Ixodes ricinus complex which saliva is able to inhibit the alternative and lectin pathways. Little is known about this activity in other species of the Ixodidae family. Thus, the aim of this study was to describe the inhibition of the classical pathway of the complement system by the saliva of Amblyomma cajennense at different stages of the haematophagy. The A. cajennense saliva and salivary gland extract (SGE) were able to inhibit the complement classical pathway through haemolytic assays with higher activity observed when saliva was used. The anti-complement activity is present in the salivary glands of starving females and also in females throughout the whole feeding process, with significant higher activity soon after tick detachment. The SGE activity from both females fed on mice or horses had no significant correlation (p > 0.05) with tick body weight. The pH found in the intestinal lumen of A. cajennense was 8.04 ± 0.08 and haemolytic assays performed at pH 8.0 showed activation of the classical pathway similarly to what occurs at pH 7.4. Consequently, inhibition could be necessary to protect the tick enterocytes. Indeed, the inhibition observed by SGE was higher in pH 8.0 in comparison to pH 7.4 reinforcing the role of saliva in protecting the intestinal cells. Further studies should be carried out in order to identify the inhibitor molecule and characterise its inhibition mechanism. Copyright © 2016 Elsevier Inc. All rights reserved.

Inhibition of the alternative complement activation pathway in traumatic brain injury by a monoclonal anti-factor B antibody: a randomized placebo-controlled study in mice

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Holers V Michael

2007-05-01

Full Text Available Abstract Background The posttraumatic response to traumatic brain injury (TBI is characterized, in part, by activation of the innate immune response, including the complement system. We have recently shown that mice devoid of a functional alternative pathway of complement activation (factor B-/- mice are protected from complement-mediated neuroinflammation and neuropathology after TBI. In the present study, we extrapolated this knowledge from studies in genetically engineered mice to a pharmacological approach using a monoclonal anti-factor B antibody. This neutralizing antibody represents a specific and potent inhibitor of the alternative complement pathway in mice. Methods A focal trauma was applied to the left hemisphere of C57BL/6 mice (n = 89 using a standardized electric weight-drop model. Animals were randomly assigned to two treatment groups: (1 Systemic injection of 1 mg monoclonal anti-factor B antibody (mAb 1379 in 400 μl phosphate-buffered saline (PBS at 1 hour and 24 hours after trauma; (2 Systemic injection of vehicle only (400 μl PBS, as placebo control, at identical time-points after trauma. Sham-operated and untreated mice served as additional negative controls. Evaluation of neurological scores and analysis of brain tissue specimens and serum samples was performed at defined time-points for up to 1 week. Complement activation in serum was assessed by zymosan assay and by murine C5a ELISA. Brain samples were analyzed by immunohistochemistry, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL histochemistry, and real-time RT-PCR. Results The mAb 1379 leads to a significant inhibition of alternative pathway complement activity and to significantly attenuated C5a levels in serum, as compared to head-injured placebo-treated control mice. TBI induced histomorphological signs of neuroinflammation and neuronal apoptosis in the injured brain hemisphere of placebo-treated control mice for up to 7 days. In contrast, the

Structure, function, pharmacology and therapeutic potential of the G protein, Gα/q,11

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Danielle eKamato

2015-03-01

Full Text Available G protein coupled receptors are one of the major classes of cell surface receptors and are associated with a group of G proteins consisting of 3 subunits termed alpha, beta and gamma. G proteins are classified into four families according to their α subunit; Gαi, Gαs, Gα12/13 and Gαq. There are several downstream pathways of Gαq of which the best known is upon activation via GTP, Gαq activates phospholipase Cβ, hydrolysing phosphatidylinositol 4,5-biphosphate into diacylglycerol and inositol triphosphate and activating protein kinase C and increasing calcium efflux from the endoplasmic recticulum. Although G proteins, in particular the Gαq/11 are central elements in GPCR signalling, their actual roles have not yet been thoroughly investigated. The lack of research of the role on Gαq/11 in cell biology is partially due to the obscure nature of the available pharmacological agents. YM-254890 is the most useful Gαq-selective inhibitor with antiplatelet, antithrombotic and thrombolytic effects. YM-254890 inhibits Gαq signalling pathways by preventing the exchange of GDP for GTP. UBO-QIC is a structurally similar compound to YM-254890 which can inhibit platelet aggregation and cause vasorelaxation in rats. Many agents are available for the study of signalling downstream of Gαq/11. The role of G proteins could potentially represents a novel therapeutic target to block all G protein dependent mechanisms. This review will explore the range of pharmacological and molecular tools available for the study of the role of Gαq/11 in GPCR signalling.

Class I HDAC inhibition is a novel pathway for regulating astrocytic apoE secretion.

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Dresselhaus, Erica; Duerr, James M; Vincent, Fabien; Sylvain, Emily K; Beyna, Mercedes; Lanyon, Lorraine F; LaChapelle, Erik; Pettersson, Martin; Bales, Kelly R; Ramaswamy, Gayathri

2018-01-01

Despite the important role of apolipoprotein E (apoE) secretion from astrocytes in brain lipid metabolism and the strong association of apoE4, one of the human apoE isoforms, with sporadic and late onset forms of Alzheimer's disease (AD) little is known about the regulation of astrocytic apoE. Utilizing annotated chemical libraries and a phenotypic screening strategy that measured apoE secretion from a human astrocytoma cell line, inhibition of pan class I histone deacetylases (HDACs) was identified as a mechanism to increase apoE secretion. Knocking down select HDAC family members alone or in combination revealed that inhibition of the class I HDAC family was responsible for enhancing apoE secretion. Knocking down LXRα and LXRβ genes revealed that the increase in astrocytic apoE in response to HDAC inhibition occurred via an LXR-independent pathway. Collectively, these data suggest that pan class I HDAC inhibition is a novel pathway for regulating astrocytic apoE secretion.

Effects of Pharmacological Inhibition and Genetic Deficiency of Plasminogen Activator Inhibitor-1 in Radiation-Induced Intestinal Injury

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Abderrahmani, Rym; Francois, Agnes; Buard, Valerie; Benderitter, Marc; Sabourin, Jean-Christophe; Crandall, David L.; Milliat, Fabien

2009-01-01

Purpose: To investigate effects of plasminogen activator inhibitor 1 (PAI-1) genetic deficiency and pharmacological PAI-1 inhibition with PAI-039 in a mouse model of radiation-induced enteropathy. Methods and Materials: Wild-type (Wt) and PAI-1 -/- knockout mice received a single dose of 19 Gy to an exteriorized localized intestinal segment. Sham and irradiated Wt mice were treated orally with 1 mg/g of PAI-039. Histological modifications were quantified using a radiation injury score. Moreover, intestinal gene expression was monitored by real-time PCR. Results: At 3 days after irradiation, PAI-039 abolished the radiation-induced increase in the plasma active form of PAI-1 and limited the radiation-induced gene expression of transforming growth factor β1 (TGF-β1), CTGF, PAI-1, and COL1A2. Moreover, PAI-039 conferred temporary protection against early lethality. PAI-039 treatment limited the radiation-induced increase of CTGF and PAI-1 at 2 weeks after irradiation but had no effect at 6 weeks. Radiation injuries were less severe in PAI-1 -/- mice than in Wt mice, and despite the beneficial effect, 3 days after irradiation, PAI-039 had no effects on microscopic radiation injuries compared to untreated Wt mice. Conclusions: A genetic deficiency of PAI-1 is associated with amelioration of late radiation enteropathy. Pharmacological inhibition of PAI-1 by PAI-039 positively impacts the early, acute phase increase in plasma PAI-1 and the associated radiation-induced gene expression of inflammatory/extracellular matrix proteins. Since PAI-039 has been shown to inhibit the active form of PAI-1, as opposed to the complete loss of PAI-1 in the knockout animals, these data suggest that a PAI-1 inhibitor could be beneficial in treating radiation-induced tissue injury in acute settings where PAI-1 is elevated.

Ouabain, a cardiac glycoside, inhibits the Fanconi anemia/BRCA pathway activated by DNA interstrand cross-linking agents.

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Dong Wha Jun

Full Text Available Modulation of the DNA repair pathway is an emerging target for the development of anticancer drugs. DNA interstrand cross-links (ICLs, one of the most severe forms of DNA damage caused by anticancer drugs such as cisplatin and mitomycin C (MMC, activates the Fanconi anemia (FA/BRCA DNA repair pathway. Inhibition of the FA/BRCA pathway can enhance the cytotoxic effects of ICL-inducing anticancer drugs and can reduce anticancer drug resistance. To find FA/BRCA pathway inhibitory small molecules, we established a cell-based high-content screening method for quantitating the activation of the FA/BRCA pathway by measuring FANCD2 foci on DNA lesions and then applied our method to chemical screening. Using commercial LOPAC1280 chemical library screening, ouabain was identified as a competent FA/BRCA pathway inhibitory compound. Ouabain, a member of the cardiac glycoside family, binds to and inhibits Na(+/K(+-ATPase and has been used to treat heart disease for many years. We observed that ouabain, as well as other cardiac glycoside family members--digitoxin and digoxin--down-regulated FANCD2 and FANCI mRNA levels, reduced monoubiquitination of FANCD2, inhibited FANCD2 foci formation on DNA lesions, and abrogated cell cycle arrest induced by MMC treatment. These inhibitory activities of ouabain required p38 MAPK and were independent of cellular Ca(2+ ion increase or the drug uptake-inhibition effect of ouabain. Furthermore, we found that ouabain potentiated the cytotoxic effects of MMC in tumor cells. Taken together, we identified an additional effect of ouabain as a FA/BRCA pathway-inhibiting chemosensitization compound. The results of this study suggest that ouabain may serve as a chemosensitizer to ICL-inducing anticancer drugs.

Dietary flavonoid derivatives enhance chemotherapeutic effect by inhibiting the DNA damage response pathway

International Nuclear Information System (INIS)

Kuo, Ching-Ying; Zupkó, István; Chang, Fang-Rong; Hunyadi, Attila; Wu, Chin-Chung; Weng, Teng-Song; Wang, Hui-Chun

2016-01-01

Flavonoids are the most common group of polyphenolic compounds and abundant in dietary fruits and vegetables. Diet high in vegetables or dietary flavonoid supplements is associated with reduced mortality rate for patients with breast cancer. Many studies have been proposed for mechanisms linking flavonoids to improving chemotherapy efficacy in many types of cancers, but data on this issue is still limited. Herein, we report on a new mechanism through which dietary flavonoids inhibit DNA damage checkpoints and repair pathways. We found that dietary flavonoids could inhibit Chk1 phosphorylation and decrease clonogenic cell growth once breast cancer cells receive ultraviolet irradiation, cisplatin, or etoposide treatment. Since the ATR-Chk1 pathway mainly involves response to DNA replication stress, we propose that flavonoid derivatives reduce the side effect of chemotherapy by improving the sensitivity of cycling cells. Therefore, we propose that increasing intake of common dietary flavonoids is beneficial to breast cancer patients who are receiving DNA-damaging chemotherapy, such as cisplatin or etoposide-based therapy. - Highlights: • First report on inhibition of both DNA damage and repair by dietary flavonoids • Dietary flavonoids inhibit cisplatin- and UV-induced Chk1 phosphorylation. • Flavonoids combined with cisplatin or UV treatment show notable growth inhibition. • Promising treatment proposal for patients who are receiving adjuvant chemotherapy

Dietary flavonoid derivatives enhance chemotherapeutic effect by inhibiting the DNA damage response pathway

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Kuo, Ching-Ying [Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Zupkó, István [Department of Pharmacodynamics and Biopharmacy, University of Szeged, Eötvös Utca 6, Szeged H-6720 (Hungary); Chang, Fang-Rong [Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Hunyadi, Attila [Institute of Pharmacognosy, Faculty of Pharmacy, University of Szeged, Eötvös Utca 6, Szeged H-6720 (Hungary); Wu, Chin-Chung; Weng, Teng-Song [Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Wang, Hui-Chun, E-mail: wanghc@kmu.edu.tw [Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); PhD Program in Translational Medicine, College of Medicine and PhD Program in Toxicology, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Research Center for Natural Product and Drug Development, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Translational Research Center and Cancer Center, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan (China); Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China)

2016-11-15

Flavonoids are the most common group of polyphenolic compounds and abundant in dietary fruits and vegetables. Diet high in vegetables or dietary flavonoid supplements is associated with reduced mortality rate for patients with breast cancer. Many studies have been proposed for mechanisms linking flavonoids to improving chemotherapy efficacy in many types of cancers, but data on this issue is still limited. Herein, we report on a new mechanism through which dietary flavonoids inhibit DNA damage checkpoints and repair pathways. We found that dietary flavonoids could inhibit Chk1 phosphorylation and decrease clonogenic cell growth once breast cancer cells receive ultraviolet irradiation, cisplatin, or etoposide treatment. Since the ATR-Chk1 pathway mainly involves response to DNA replication stress, we propose that flavonoid derivatives reduce the side effect of chemotherapy by improving the sensitivity of cycling cells. Therefore, we propose that increasing intake of common dietary flavonoids is beneficial to breast cancer patients who are receiving DNA-damaging chemotherapy, such as cisplatin or etoposide-based therapy. - Highlights: • First report on inhibition of both DNA damage and repair by dietary flavonoids • Dietary flavonoids inhibit cisplatin- and UV-induced Chk1 phosphorylation. • Flavonoids combined with cisplatin or UV treatment show notable growth inhibition. • Promising treatment proposal for patients who are receiving adjuvant chemotherapy.

Development of a pluripotent stem cell derived neuronal model to identify chemically induced pathway perturbations in relation to neurotoxicity: Effects of CREB pathway inhibition

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Pistollato, Francesca; Louisse, Jochem; Scelfo, Bibiana; Mennecozzi, Milena [Institute for Health and Consumer Protection (IHCP), JRC, Ispra (Italy); Accordi, Benedetta; Basso, Giuseppe [Oncohematology Laboratory, Department of Woman and Child Health, University of Padova, Padova (Italy); Gaspar, John Antonydas [Center of Physiology and Pathophysiology, Institute of Neurophysiology, University of Cologne, Cologne (Germany); Zagoura, Dimitra; Barilari, Manuela; Palosaari, Taina [Institute for Health and Consumer Protection (IHCP), JRC, Ispra (Italy); Sachinidis, Agapios [Center of Physiology and Pathophysiology, Institute of Neurophysiology, University of Cologne, Cologne (Germany); Bremer-Hoffmann, Susanne, E-mail: susanne.bremer@jrc.ec.europa.eu [Institute for Health and Consumer Protection (IHCP), JRC, Ispra (Italy)

2014-10-15

According to the advocated paradigm shift in toxicology, acquisition of knowledge on the mechanisms underlying the toxicity of chemicals, such as perturbations of biological pathways, is of primary interest. Pluripotent stem cells (PSCs), such as human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs), offer a unique opportunity to derive physiologically relevant human cell types to measure molecular and cellular effects of such pathway modulations. Here we compared the neuronal differentiation propensity of hESCs and hiPSCs with the aim to develop novel hiPSC-based tools for measuring pathway perturbation in relation to molecular and cellular effects in vitro. Among other fundamental pathways, also, the cAMP responsive element binding protein (CREB) pathway was activated in our neuronal models and gave us the opportunity to study time-dependent effects elicited by chemical perturbations of the CREB pathway in relation to cellular effects. We show that the inhibition of the CREB pathway, using 2-naphthol-AS-E-phosphate (KG-501), induced an inhibition of neurite outgrowth and synaptogenesis, as well as a decrease of MAP2{sup +} neuronal cells. These data indicate that a CREB pathway inhibition can be related to molecular and cellular effects that may be relevant for neurotoxicity testing, and, thus, qualify the use of our hiPSC-derived neuronal model for studying chemical-induced neurotoxicity resulting from pathway perturbations. - Highlights: • HESCs derived neuronal cells serve as benchmark for iPSC based neuronal toxicity test development. • Comparisons between hESCs and hiPSCs demonstrated variability of the epigenetic state • CREB pathway modulation have been explored in relation to the neurotoxicant exposure KG-501 • hiPSC might be promising tools to translate theoretical AoPs into toxicological in vitro tests.

Lipopolysaccharide preconditioning protects hepatocytes from ischemia/reperfusion injury (IRI through inhibiting ATF4-CHOP pathway in mice.

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Jianhua Rao

Full Text Available BACKGROUND: Low-dose lipopolysaccharide (LPS preconditioning-induced liver protection has been demonstrated during ischemia-reperfusion injury (IRI in several organs but has not been sufficiently elucidated underlying causal mechanism. This study investigated the role of low-dose LPS preconditioning on ATF4-CHOP pathway as well as the effects of the pathway on tissue injury and inflammation in a mouse model of liver partial-warm IRI. METHODS: LPS (100 µg/kg/d was injected intraperitoneally two days before ischemia. Hepatic injury was evaluated based on serum alanine aminotransferase levels, histopathology, and caspase-3 activity. The ATF4-CHOP pathway and its related apoptotic molecules were investigated after reperfusion. The role of LPS preconditioning on apoptosis and ATF4-CHOP pathway was examined in vitro. Moreover, the effects of the ATF4-CHOP pathway on apoptosis, Caspase-12, and Caspase-3 were determined with ATF4 small interfering RNA (siRNA. Inflammatory cytokine expression was also checked after reperfusion. Inflammatory cytokines and related signaling pathways were analyzed in vitro in macrophages treated by LPS preconditioning or ATF4 siRNA. RESULTS: LPS preconditioning significantly attenuated liver injury after IRI. As demonstrated by in vitro experiments, LPS preconditioning significantly reduced the upregulation of the ATF4-CHOP pathway and inhibited Caspase-12 and Caspase-3 activation after IRI. Later experiments showed that ATF4 knockdown significantly suppressed CHOP, cleaved caspase-12 and caspase-3 expression, as well as inhibited hepatocellular apoptosis. In addition, in mice pretreated with LPS, TNF-α and IL-6 were inhibited after reperfusion, whereas IL-10 was upregulated. Similarly, low-dose LPS significantly inhibited TNF-α, IL-6, ATF4-CHOP pathway, NF-κB pathway, and ERK1/2 in high-dose LPS-stimulated macrophages, whereas IL-10 and cytokine signaling (SOCS-3 suppressor were induced. Importantly, ATF4 siRNA is

Anti-aging pharmacology in cutaneous wound healing: effects of metformin, resveratrol, and rapamycin by local application.

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Zhao, Pan; Sui, Bing-Dong; Liu, Nu; Lv, Ya-Jie; Zheng, Chen-Xi; Lu, Yong-Bo; Huang, Wen-Tao; Zhou, Cui-Hong; Chen, Ji; Pang, Dan-Lin; Fei, Dong-Dong; Xuan, Kun; Hu, Cheng-Hu; Jin, Yan

2017-10-01

Cutaneous wounds are among the most common soft tissue injuries and are particularly hard to heal in aging. Caloric restriction (CR) is well documented to extend longevity; pharmacologically, profound rejuvenative effects of CR mimetics have been uncovered, especially metformin (MET), resveratrol (RSV), and rapamycin (RAPA). However, locally applied impacts and functional differences of these agents on wound healing remain to be established. Here, we discovered that chronic topical administration of MET and RSV, but not RAPA, accelerated wound healing with improved epidermis, hair follicles, and collagen deposition in young rodents, and MET exerted more profound effects. Furthermore, locally applied MET and RSV improved vascularization of the wound beds, which were attributed to stimulation of adenosine monophosphate-activated protein kinase (AMPK) pathway, the key mediator of wound healing. Notably, in aged skin, AMPK pathway was inhibited, correlated with impaired vasculature and reduced healing ability. As therapeutic approaches, local treatments of MET and RSV prevented age-related AMPK suppression and angiogenic inhibition in wound beds. Moreover, in aged rats, rejuvenative effects of topically applied MET and RSV on cell viability of wound beds were confirmed, of which MET showed more prominent anti-aging effects. We further verified that only MET promoted wound healing and cutaneous integrity in aged skin. These findings clarified differential effects of CR-based anti-aging pharmacology in wound healing, identified critical angiogenic and rejuvenative mechanisms through AMPK pathway in both young and aged skin, and unraveled chronic local application of MET as the optimal and promising regenerative agent in treating cutaneous wound defects. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Allosteric inhibition of SHP2 phosphatase inhibits cancers driven by receptor tyrosine kinases

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Chen, Ying-Nan P.; LaMarche, Matthew J.; Chan, Ho Man; Fekkes, Peter; Garcia-Fortanet, Jorge; Acker, Michael G.; Antonakos, Brandon; Chen, Christine Hiu-Tung; Chen, Zhouliang; Cooke, Vesselina G.; Dobson, Jason R.; Deng, Zhan; Fei, Feng; Firestone, Brant; Fodor, Michelle; Fridrich, Cary; Gao, Hui; Grunenfelder, Denise; Hao, Huai-Xiang; Jacob, Jaison; Ho, Samuel; Hsiao, Kathy; Kang, Zhao B.; Karki, Rajesh; Kato, Mitsunori; Larrow, Jay; La Bonte, Laura R.; Lenoir, Francois; Liu, Gang; Liu, Shumei; Majumdar, Dyuti; Meyer, Matthew J.; Palermo, Mark; Perez, Lawrence; Pu, Minying; Price, Edmund; Quinn, Christopher; Shakya, Subarna; Shultz, Michael D.; Slisz, Joanna; Venkatesan, Kavitha; Wang, Ping; Warmuth, Markus; Williams, Sarah; Yang, Guizhi; Yuan, Jing; Zhang, Ji-Hu; Zhu, Ping; Ramsey, Timothy; Keen, Nicholas J.; Sellers, William R.; Stams, Travis; Fortin , Pascal D. (Novartis)

2016-06-29

The non-receptor protein tyrosine phosphatase SHP2, encoded by PTPN11, has an important role in signal transduction downstream of growth factor receptor signalling and was the first reported oncogenic tyrosine phosphatase1. Activating mutations of SHP2 have been associated with developmental pathologies such as Noonan syndrome and are found in multiple cancer types, including leukaemia, lung and breast cancer and neuroblastoma1, 2, 3, 4, 5. SHP2 is ubiquitously expressed and regulates cell survival and proliferation primarily through activation of the RAS–ERK signalling pathway2, 3. It is also a key mediator of the programmed cell death 1 (PD-1) and B- and T-lymphocyte attenuator (BTLA) immune checkpoint pathways6, 7. Reduction of SHP2 activity suppresses tumour cell growth and is a potential target of cancer therapy8, 9. Here we report the discovery of a highly potent (IC50 = 0.071 μM), selective and orally bioavailable small-molecule SHP2 inhibitor, SHP099, that stabilizes SHP2 in an auto-inhibited conformation. SHP099 concurrently binds to the interface of the N-terminal SH2, C-terminal SH2, and protein tyrosine phosphatase domains, thus inhibiting SHP2 activity through an allosteric mechanism. SHP099 suppresses RAS–ERK signalling to inhibit the proliferation of receptor-tyrosine-kinase-driven human cancer cells in vitro and is efficacious in mouse tumour xenograft models. Together, these data demonstrate that pharmacological inhibition of SHP2 is a valid therapeutic approach for the treatment of cancers.

TNP [N2-(m-Trifluorobenzyl, N6-(p-nitrobenzylpurine] ameliorates diet induced obesity and insulin resistance via inhibition of the IP6K1 pathway

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Sarbani Ghoshal

2016-10-01

Full Text Available Objective: Obesity and type 2 diabetes (T2D lead to various life-threatening diseases such as coronary heart disease, stroke, osteoarthritis, asthma, and neurodegeneration. Therefore, extensive research is ongoing to identify novel pathways that can be targeted in obesity/T2D. Deletion of the inositol pyrophosphate (5-IP7 biosynthetic enzyme, inositol hexakisphosphate kinase-1 (IP6K1, protects mice from high fat diet (HFD induced obesity (DIO and insulin resistance. Yet, whether this pathway is a valid pharmacologic target in obesity/T2D is not known. Here, we demonstrate that TNP [N2-(m-Trifluorobenzyl, N6-(p-nitrobenzylpurine], a pan-IP6K inhibitor, has strong anti-obesity and anti-diabetic effects in DIO mice. Methods: Q-NMR, GTT, ITT, food intake, energy expenditure, QRT-PCR, ELISA, histology, and immunoblot studies were conducted in short (2.5-week- and long (10-week-term TNP treated DIO C57/BL6 WT and IP6K1-KO mice, under various diet and temperature conditions. Results: TNP, when injected at the onset of HFD-feeding, decelerates initiation of DIO and insulin resistance. Moreover, TNP facilitates weight loss and restores metabolic parameters, when given to DIO mice. However, TNP does not reduce weight gain in HFD-fed IP6K1-KO mice. TNP specifically enhances insulin sensitivity in DIO mice via Akt activation. TNP decelerates weight gain primarily by enhancing thermogenic energy expenditure in the adipose tissue. Accordingly, TNP's effect on body weight is partly abolished whereas its impact on glucose homeostasis is preserved at thermoneutral temperature. Conclusion: Pharmacologic inhibition of the inositol pyrophosphate pathway has strong therapeutic potential in obesity, T2D, and other metabolic diseases. Author Video: Author Video Watch what authors say about their articles Keywords: IP6K, Inositol pyrophosphate, Obesity, Energy expenditure, Diabetes, Akt

Camptothecin inhibits platelet-derived growth factor-BB-induced proliferation of rat aortic vascular smooth muscle cells through inhibition of PI3K/Akt signaling pathway

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Park, Eun-Seok [Department of Applied Biochemistry, Division of Life Science, College of Health and Biomedical Science, Konkuk University, Chungju, Chungbuk (Korea, Republic of); Kang, Shin-il [College of Pharmacy Medical Research Center, Chungbuk National University, Cheongju (Korea, Republic of); Yoo, Kyu-dong [Hazardous Substances Analysis Division, Gwangju Regional Food and Drug Administration, Gwangju (Korea, Republic of); Lee, Mi-Yea [Department of Nursing Kyungbok University, Pocheon (Korea, Republic of); Yoo, Hwan-Soo; Hong, Jin-Tae [College of Pharmacy Medical Research Center, Chungbuk National University, Cheongju (Korea, Republic of); Shin, Hwa-Sup [Department of Applied Biochemistry, Division of Life Science, College of Health and Biomedical Science, Konkuk University, Chungju, Chungbuk (Korea, Republic of); Kim, Bokyung [Department of Physiology, Konkuk Medical School, Konkuk University, Chungju, Chungbuk (Korea, Republic of); Yun, Yeo-Pyo, E-mail: ypyun@chungbuk.ac.kr [College of Pharmacy Medical Research Center, Chungbuk National University, Cheongju (Korea, Republic of)

2013-04-15

The abnormal proliferation of vascular smooth muscle cells (VSMCs) in arterial wall is a major cause of vascular disorders such as atherosclerosis and restenosis after angioplasty. In this study, we investigated not only the inhibitory effects of camptothecin (CPT) on PDGF-BB-induced VSMC proliferation, but also its molecular mechanism of this inhibition. CPT significantly inhibited proliferation with IC50 value of 0.58 μM and the DNA synthesis of PDGF-BB-stimulated VSMCs in a dose-dependent manner (0.5–2 μM ) without any cytotoxicity. CPT induced the cell cycle arrest at G0/G1 phase. Also, CPT decreased the expressions of G0/G1-specific regulatory proteins including cyclin-dependent kinase (CDK)2, cyclin D1 and PCNA in PDGF-BB-stimulated VSMCs. Pre-incubation of VSMCs with CPT significantly inhibited PDGF-BB-induced Akt activation, whereas CPT did not affect PDGF-receptor beta phosphorylation, extracellular signal-regulated kinase (ERK) 1/2 phosphorylation and phospholipase C (PLC)-γ1 phosphorylation in PDGF-BB signaling pathway. Our data showed that CPT pre-treatment inhibited VSMC proliferation, and that the inhibitory effect of CPT was enhanced by LY294002, a PI3K inhibitor, on PDGF-BB-induced VSMC proliferation. In addition, inhibiting the PI3K/Akt pathway by LY294002 significantly enhanced the suppression of PCNA expression and Akt activation by CPT. These results suggest that the anti-proliferative activity of CPT is mediated in part by downregulating the PI3K/Akt signaling pathway. - Highlights: ► CPT inhibits proliferation of PDGF-BB-induced VSMC without cytotoxicity. ► CPT arrests the cell cycle in G0/G1 phase by downregulation of cyclin D1 and CDK2. ► CPT significantly attenuates Akt phosphorylation in PDGF-BB signaling pathway. ► LY294002 enhanced the inhibitory effect of CPT on VSMC proliferation. ► Thus, CPT is mediated by downregulating the PI3K/Akt signaling pathway.

Camptothecin inhibits platelet-derived growth factor-BB-induced proliferation of rat aortic vascular smooth muscle cells through inhibition of PI3K/Akt signaling pathway

International Nuclear Information System (INIS)

Park, Eun-Seok; Kang, Shin-il; Yoo, Kyu-dong; Lee, Mi-Yea; Yoo, Hwan-Soo; Hong, Jin-Tae; Shin, Hwa-Sup; Kim, Bokyung; Yun, Yeo-Pyo

2013-01-01

The abnormal proliferation of vascular smooth muscle cells (VSMCs) in arterial wall is a major cause of vascular disorders such as atherosclerosis and restenosis after angioplasty. In this study, we investigated not only the inhibitory effects of camptothecin (CPT) on PDGF-BB-induced VSMC proliferation, but also its molecular mechanism of this inhibition. CPT significantly inhibited proliferation with IC50 value of 0.58 μM and the DNA synthesis of PDGF-BB-stimulated VSMCs in a dose-dependent manner (0.5–2 μM ) without any cytotoxicity. CPT induced the cell cycle arrest at G0/G1 phase. Also, CPT decreased the expressions of G0/G1-specific regulatory proteins including cyclin-dependent kinase (CDK)2, cyclin D1 and PCNA in PDGF-BB-stimulated VSMCs. Pre-incubation of VSMCs with CPT significantly inhibited PDGF-BB-induced Akt activation, whereas CPT did not affect PDGF-receptor beta phosphorylation, extracellular signal-regulated kinase (ERK) 1/2 phosphorylation and phospholipase C (PLC)-γ1 phosphorylation in PDGF-BB signaling pathway. Our data showed that CPT pre-treatment inhibited VSMC proliferation, and that the inhibitory effect of CPT was enhanced by LY294002, a PI3K inhibitor, on PDGF-BB-induced VSMC proliferation. In addition, inhibiting the PI3K/Akt pathway by LY294002 significantly enhanced the suppression of PCNA expression and Akt activation by CPT. These results suggest that the anti-proliferative activity of CPT is mediated in part by downregulating the PI3K/Akt signaling pathway. - Highlights: ► CPT inhibits proliferation of PDGF-BB-induced VSMC without cytotoxicity. ► CPT arrests the cell cycle in G0/G1 phase by downregulation of cyclin D1 and CDK2. ► CPT significantly attenuates Akt phosphorylation in PDGF-BB signaling pathway. ► LY294002 enhanced the inhibitory effect of CPT on VSMC proliferation. ► Thus, CPT is mediated by downregulating the PI3K/Akt signaling pathway

Inhibition of PIP4Kγ ameliorates the pathological effects of mutant huntingtin protein.

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Al-Ramahi, Ismael; Panapakkam Giridharan, Sai Srinivas; Chen, Yu-Chi; Patnaik, Samarjit; Safren, Nathaniel; Hasegawa, Junya; de Haro, Maria; Wagner Gee, Amanda K; Titus, Steven A; Jeong, Hyunkyung; Clarke, Jonathan; Krainc, Dimitri; Zheng, Wei; Irvine, Robin F; Barmada, Sami; Ferrer, Marc; Southall, Noel; Weisman, Lois S; Botas, Juan; Marugan, Juan Jose

2017-12-26

The discovery of the causative gene for Huntington's disease (HD) has promoted numerous efforts to uncover cellular pathways that lower levels of mutant huntingtin protein (mHtt) and potentially forestall the appearance of HD-related neurological defects. Using a cell-based model of pathogenic huntingtin expression, we identified a class of compounds that protect cells through selective inhibition of a lipid kinase, PIP4Kγ. Pharmacological inhibition or knock-down of PIP4Kγ modulates the equilibrium between phosphatidylinositide (PI) species within the cell and increases basal autophagy, reducing the total amount of mHtt protein in human patient fibroblasts and aggregates in neurons. In two Drosophila models of Huntington's disease, genetic knockdown of PIP4K ameliorated neuronal dysfunction and degeneration as assessed using motor performance and retinal degeneration assays respectively. Together, these results suggest that PIP4Kγ is a druggable target whose inhibition enhances productive autophagy and mHtt proteolysis, revealing a useful pharmacological point of intervention for the treatment of Huntington's disease, and potentially for other neurodegenerative disorders.

ROCK inhibition in models of neurodegeneration and its potential for clinical translation.

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Koch, Jan Christoph; Tatenhorst, Lars; Roser, Anna-Elisa; Saal, Kim-Ann; Tönges, Lars; Lingor, Paul

2018-04-03

Neurodegenerative disorders like Parkinson's disease, Alzheimer's disease, or amyotrophic lateral sclerosis are affecting a rapidly increasing population worldwide. While common pathomechanisms such as protein aggregation, axonal degeneration, dysfunction of protein clearing and an altered immune response have been characterized, no disease-modifying therapies have been developed so far. Interestingly, a significant involvement of the Rho kinase (ROCK) signaling pathway has been described in all of these mechanisms making it a promising target for new therapeutic approaches. In this article, we first review current knowledge of the involvement of ROCK in neurodegenerative disorders and the utility of its inhibition as a disease-modifying therapy in different neurodegenerative disorders. After a detailed description of the biochemical characteristics of ROCK and its molecular interactors, differences of ROCK-expression under physiological and pathological conditions are compared. Next, different pharmacological and molecular-genetic strategies to inhibit ROCK-function are discussed, focusing on pharmacological ROCK-inhibitors. The role of the ROCK-pathway in cellular processes that are central in neurodegenerative disorders pathology like axonal degeneration, autophagy, synaptic and glial function is explained in detail. Finally, all available data on ROCK-inhibition in different animal models of neurodegenerative disorders is reviewed and first approaches for translation into human patients are discussed. Taken together, there is now extensive evidence from preclinical studies in several neurodegenerative disorders that characterize ROCK as a promising drug target for further translational research in neurodegenerative disorders. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Structural Requirements for Yersinia YopJ Inhibition of MAP Kinase Pathways

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Burdette, Dara; Mukherjee, Sohini; Keitany, Gladys; Goldsmith, Elizabeth; Orth, Kim

2008-01-01

MAPK signaling cascades are evolutionally conserved. The bacterial effector, YopJ, uses the unique activity of Ser/Thr acetylation to inhibit the activation of the MAPK kinase (MKK) and prevent activation by phosphorylation. YopJ is also able to block yeast MAPK signaling pathways using this mechanism. Based on these observations, we performed a genetic screen to isolate mutants in the yeast MKK, Pbs2, that suppress YopJ inhibition. One suppressor contains a mutation in a conserved tyrosine residue and bypasses YopJ inhibition by increasing the basal activity of Pbs2. Mutations on the hydrophobic face of the conserved G α-helix in the kinase domain prevent both binding and acetylation by YopJ. Corresponding mutants in human MKKs showed that they are conserved not only structurally, but also functionally. These studies reveal a conserved binding site found on the superfamily of MAPK kinases while providing insight into the molecular interactions required for YopJ inhibition. PMID:18167536

Structural requirements for Yersinia YopJ inhibition of MAP kinase pathways.

Directory of Open Access Journals (Sweden)

Yi-Heng Hao

2008-01-01

Full Text Available MAPK signaling cascades are evolutionally conserved. The bacterial effector, YopJ, uses the unique activity of Ser/Thr acetylation to inhibit the activation of the MAPK kinase (MKK and prevent activation by phosphorylation. YopJ is also able to block yeast MAPK signaling pathways using this mechanism. Based on these observations, we performed a genetic screen to isolate mutants in the yeast MKK, Pbs2, that suppress YopJ inhibition. One suppressor contains a mutation in a conserved tyrosine residue and bypasses YopJ inhibition by increasing the basal activity of Pbs2. Mutations on the hydrophobic face of the conserved G alpha-helix in the kinase domain prevent both binding and acetylation by YopJ. Corresponding mutants in human MKKs showed that they are conserved not only structurally, but also functionally. These studies reveal a conserved binding site found on the superfamily of MAPK kinases while providing insight into the molecular interactions required for YopJ inhibition.

The major cellular sterol regulatory pathway is required for Andes virus infection.

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Josiah Petersen

2014-02-01

Full Text Available The Bunyaviridae comprise a large family of RNA viruses with worldwide distribution and includes the pathogenic New World hantavirus, Andes virus (ANDV. Host factors needed for hantavirus entry remain largely enigmatic and therapeutics are unavailable. To identify cellular requirements for ANDV infection, we performed two parallel genetic screens. Analysis of a large library of insertionally mutagenized human haploid cells and a siRNA genomic screen converged on components (SREBP-2, SCAP, S1P and S2P of the sterol regulatory pathway as critically important for infection by ANDV. The significance of this pathway was confirmed using functionally deficient cells, TALEN-mediated gene disruption, RNA interference and pharmacologic inhibition. Disruption of sterol regulatory complex function impaired ANDV internalization without affecting virus binding. Pharmacologic manipulation of cholesterol levels demonstrated that ANDV entry is sensitive to changes in cellular cholesterol and raises the possibility that clinically approved regulators of sterol synthesis may prove useful for combating ANDV infection.

TNP [N2-(m-Trifluorobenzyl), N6-(p-nitrobenzyl)purine] ameliorates diet induced obesity and insulin resistance via inhibition of the IP6K1 pathway.

Science.gov (United States)

Ghoshal, Sarbani; Zhu, Qingzhang; Asteian, Alice; Lin, Hua; Xu, Haifei; Ernst, Glen; Barrow, James C; Xu, Baoji; Cameron, Michael D; Kamenecka, Theodore M; Chakraborty, Anutosh

2016-10-01

Obesity and type 2 diabetes (T2D) lead to various life-threatening diseases such as coronary heart disease, stroke, osteoarthritis, asthma, and neurodegeneration. Therefore, extensive research is ongoing to identify novel pathways that can be targeted in obesity/T2D. Deletion of the inositol pyrophosphate (5-IP7) biosynthetic enzyme, inositol hexakisphosphate kinase-1 (IP6K1), protects mice from high fat diet (HFD) induced obesity (DIO) and insulin resistance. Yet, whether this pathway is a valid pharmacologic target in obesity/T2D is not known. Here, we demonstrate that TNP [N2-(m-Trifluorobenzyl), N6-(p-nitrobenzyl)purine], a pan-IP6K inhibitor, has strong anti-obesity and anti-diabetic effects in DIO mice. Q-NMR, GTT, ITT, food intake, energy expenditure, QRT-PCR, ELISA, histology, and immunoblot studies were conducted in short (2.5-week)- and long (10-week)-term TNP treated DIO C57/BL6 WT and IP6K1-KO mice, under various diet and temperature conditions. TNP, when injected at the onset of HFD-feeding, decelerates initiation of DIO and insulin resistance. Moreover, TNP facilitates weight loss and restores metabolic parameters, when given to DIO mice. However, TNP does not reduce weight gain in HFD-fed IP6K1-KO mice. TNP specifically enhances insulin sensitivity in DIO mice via Akt activation. TNP decelerates weight gain primarily by enhancing thermogenic energy expenditure in the adipose tissue. Accordingly, TNP's effect on body weight is partly abolished whereas its impact on glucose homeostasis is preserved at thermoneutral temperature. Pharmacologic inhibition of the inositol pyrophosphate pathway has strong therapeutic potential in obesity, T2D, and other metabolic diseases.

Traditional Chinese Medicine CFF-1 induced cell growth inhibition, autophagy, and apoptosis via inhibiting EGFR-related pathways in prostate cancer.

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Wu, Zhaomeng; Zhu, Qingyi; Yin, Yingying; Kang, Dan; Cao, Runyi; Tian, Qian; Zhang, Yu; Lu, Shan; Liu, Ping

2018-04-01

Traditional Chinese medicine (TCM) has a combined therapeutic result in cancer treatment by integrating holistic and local therapeutical effects, by which TCM can enhance the curative effect and reduce the side effect. In this study, we analyzed the effect of CFF-1 (alcohol extract from an anticancer compound Chinese medicine) on prostate cancer (PCa) cell lines and studied in detail the mechanism of cell death induced by CFF-1 in vitro and in vivo. From our data, we found for the first time that CFF-1 obviously arrested cell cycle in G1 phase, decreased cell viability and then increased nuclear rupture in a dose-dependent manner and finally resulted in apoptosis in prostate cancer cells. In molecular level, our data showed that CFF-1 induced inhibition of EGFR auto-phosphorylation and inactivation of EGFR. Disruption of EGFR activity in turn suppressed downstream PI3K/AKT and Raf/Erk signal pathways, resulted in the decrease of p-FOXO1 (Ser256) and regulated the expression of apoptosis-related and cycle-related genes. Moreover, CFF-1 markedly induced cell autophagy through inhibiting PI3K/AKT/mTOR pathway and then up-regulating Beclin-1 and LC-3II and down-regulating phosphorylation of p70S6K. In vivo, CFF-1-treated group exhibited a significant decrease in tumor volume compared with the negative control group in subcutaneous xenograft tumor in nude mice via inhibiting EGFR-related signal pathways. Thus, bio-functions of Chinese medicine CFF-1 in inducing PCa cell growth inhibition, autophagy, and apoptosis suggested that CFF-1 had the clinical potential to treat patients with prostate cancer. © 2018 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Pharmacological activities of Vitex agnus-castus extracts in vitro.

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Meier, B; Berger, D; Hoberg, E; Sticher, O; Schaffner, W

2000-10-01

The pharmacological effects of ethanolic Vitex agnus-castus fruit-extracts (especially Ze 440) and various extract fractions of different polarities were evaluated both by radioligand binding studies and by superfusion experiments. A relative potent binding inhibition was observed for dopamine D2 and opioid (micro and kappa subtype) receptors with IC50 values of the native extract between 20 and 70 mg/mL. Binding, neither to the histamine H1, benzodiazepine and OFQ receptor, nor to the binding-site of the serotonin (5-HT) transporter, was significantly inhibited. The lipophilic fractions contained the diterpenes rotun-difuran and 6beta,7beta-diacetoxy-13-hydroxy-labda-8,14-dien . They exhibited inhibitory actions on dopamine D2 receptor binding. While binding inhibition to mu and kappa opioid receptors was most pronounced in lipophilic fractions, binding to delta opioid receptors was inhibited mainly by a aqueous fraction. Standardised Ze 440 extracts of different batches were of constant pharmacological quality according to their potential to inhibit the binding to D2 receptors. In superfusion experiments, the aqueous fraction of a methanolic extract inhibited the release of acetylcholine in a concentration-dependent manner. In addition, the potent D2 receptor antagonist spiperone antagonised the effect of the extract suggesting a dopaminergic action mediated by D2 receptor activation. Our results indicate a dopaminergic effect of Vitex agnus-castus extracts and suggest additional pharmacological actions via opioid receptors.

Luteolin inhibits the Nrf2 signaling pathway and tumor growth in vivo

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Chian, Song; Thapa, Ruby; Chi, Zhexu [Department of Biochemistry and Genetics, School of Medicine, Zhejiang University, Hangzhou 310058 (China); Wang, Xiu Jun [Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058 (China); Tang, Xiuwen, E-mail: xiuwentang@zju.edu.cn [Department of Biochemistry and Genetics, School of Medicine, Zhejiang University, Hangzhou 310058 (China)

2014-05-16

Highlights: • Luteolin inhibits the Nrf2 pathway in mouse liver and in xenografted tumors. • Luteolin markedly inhibits the growth of xenograft tumors. • Luteolin enhances the anti-cancer effect of cisplatin in mice in vivo. • Luteolin could serve as an adjuvant in the chemotherapy of NSCLC. - Abstract: Nuclear factor erythroid 2-related factor 2 (Nrf2) is over-expressed in many types of tumor, promotes tumor growth, and confers resistance to anticancer therapy. Hence, Nrf2 is regarded as a novel therapeutic target in cancer. Previously, we reported that luteolin is a strong inhibitor of Nrf2 in vitro. Here, we showed that luteolin reduced the constitutive expression of NAD(P)H quinone oxidoreductase 1 in mouse liver in a time- and dose-dependent manner. Further, luteolin inhibited the expression of antioxidant enzymes and glutathione transferases, decreasing the reduced glutathione in the liver of wild-type mice under both constitutive and butylated hydroxyanisole-induced conditions. In contrast, such distinct responses were not detected in Nrf2{sup −/−} mice. In addition, oral administration of luteolin, either alone or combined with intraperitoneal injection of the cytotoxic drug cisplatin, greatly inhibited the growth of xenograft tumors from non-small-cell lung cancer (NSCLC) cell line A549 cells grown subcutaneously in athymic nude mice. Cell proliferation, the expression of Nrf2, and antioxidant enzymes were all reduced in tumor xenograft tissues. Furthermore, luteolin enhanced the anti-cancer effect of cisplatin. Together, our findings demonstrated that luteolin inhibits the Nrf2 pathway in vivo and can serve as an adjuvant in the chemotherapy of NSCLC.

Pharmacological inhibition of lysosomes activates the MTORC1 signaling pathway in chondrocytes in an autophagy-independent manner.

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Newton, Phillip T; Vuppalapati, Karuna K; Bouderlique, Thibault; Chagin, Andrei S

2015-01-01

Mechanistic target of rapamycin (serine/threonine kinase) complex 1 (MTORC1) is a protein-signaling complex at the fulcrum of anabolic and catabolic processes, which acts depending on wide-ranging environmental cues. It is generally accepted that lysosomes facilitate MTORC1 activation by generating an internal pool of amino acids. Amino acids activate MTORC1 by stimulating its translocation to the lysosomal membrane where it forms a super-complex involving the lysosomal-membrane-bound vacuolar-type H(+)-ATPase (v-ATPase) proton pump. This translocation and MTORC1 activation require functional lysosomes. Here we found that, in contrast to this well-accepted concept, in epiphyseal chondrocytes inhibition of lysosomal activity by v-ATPase inhibitors bafilomycin A1 or concanamycin A potently activated MTORC1 signaling. The activity of MTORC1 was visualized by phosphorylated forms of RPS6 (ribosomal protein S6) and EIF4EBP1, 2 well-known downstream targets of MTORC1. Maximal RPS6 phosphorylation was observed at 48-h treatment and reached as high as a 12-fold increase (p lysosomes. Thus, our data show that in epiphyseal chondrocytes lysosomes inhibit MTORC1 in a macroautophagy-independent manner and this inhibition likely depends on v-ATPase activity.

Chk1 inhibition activates p53 through p38 MAPK in tetraploid cancer cells.

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Vitale, Ilio; Senovilla, Laura; Galluzzi, Lorenzo; Criollo, Alfredo; Vivet, Sonia; Castedo, Maria; Kroemer, Guido

2008-07-01

We have previously shown that tetraploid cancer cells succumb through a p53-dependent apoptotic pathway when checkpoint kinase 1 (Chk1) is depleted by small interfering RNAs (siRNAs) or inhibited with 7-hydroxystaurosporine (UCN-01). Here, we demonstrate that Chk1 inhibition results in the activating phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK). Depletion of p38 MAPK by transfection with a siRNA targeting the alpha isoform of p38 MAPK (p38alpha MAPK) abolishes the phosphorylation of p53 on serines 15 and 46 that is induced by Chk1 knockdown. The siRNA-mediated downregulation and pharmacological inhibition of p38alpha MAPK (with SB 203580) also reduces cell death induced by Chk1 knockdown or UCN-01. These results underscore the role of p38 MAPK as a pro-apoptotic kinase in the p53-dependant pathway for the therapeutic elimination of polyploidy cells.

The pharmacology of visuospatial attention and inhibition

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Logemann, H.N.A.

2013-01-01

Attention and inhibition are of vital importance in everyday functioning. Problems of attention and inhibition are central to disorders such as Attention Deficit/Hyperactivity Disorder (ADHD). Both bias and disengagement key components of visuospatial attention. Bias refers to neuronal signals that

The Role of Wnt Signal in Glioblastoma Development and Progression: A Possible New Pharmacological Target for the Therapy of This Tumor.

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Zuccarini, Mariachiara; Giuliani, Patricia; Ziberi, Sihana; Carluccio, Marzia; Iorio, Patrizia Di; Caciagli, Francesco; Ciccarelli, Renata

2018-02-17

Wnt is a complex signaling pathway involved in the regulation of crucial biological functions such as development, proliferation, differentiation and migration of cells, mainly stem cells, which are virtually present in all embryonic and adult tissues. Conversely, dysregulation of Wnt signal is implicated in development/progression/invasiveness of different kinds of tumors, wherein a certain number of multipotent cells, namely "cancer stem cells", are characterized by high self-renewal and aggressiveness. Hence, the pharmacological modulation of Wnt pathway could be of particular interest, especially in tumors for which the current standard therapy results to be unsuccessful. This might be the case of glioblastoma multiforme (GBM), one of the most lethal, aggressive and recurrent brain cancers, probably due to the presence of highly malignant GBM stem cells (GSCs) as well as to a dysregulation of Wnt system. By examining the most recent literature, here we point out several factors in the Wnt pathway that are altered in human GBM and derived GSCs, as well as new molecular strategies or experimental drugs able to modulate/inhibit aberrant Wnt signal. Altogether, these aspects serve to emphasize the existence of alternative pharmacological targets that may be useful to develop novel therapies for GBM.

Carotenoids: biochemistry, pharmacology and treatment.

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Milani, Alireza; Basirnejad, Marzieh; Shahbazi, Sepideh; Bolhassani, Azam

2017-06-01

Carotenoids and retinoids have several similar biological activities such as antioxidant properties, the inhibition of malignant tumour growth and the induction of apoptosis. Supplementation with carotenoids can affect cell growth and modulate gene expression and immune responses. Epidemiological studies have shown a correlation between a high carotenoid intake in the diet with a reduced risk of breast, cervical, ovarian, colorectal cancers, and cardiovascular and eye diseases. Cancer chemoprevention by dietary carotenoids involves several mechanisms, including effects on gap junctional intercellular communication, growth factor signalling, cell cycle progression, differentiation-related proteins, retinoid-like receptors, antioxidant response element, nuclear receptors, AP-1 transcriptional complex, the Wnt/β-catenin pathway and inflammatory cytokines. Moreover, carotenoids can stimulate the proliferation of B- and T-lymphocytes, the activity of macrophages and cytotoxic T-cells, effector T-cell function and the production of cytokines. Recently, the beneficial effects of carotenoid-rich vegetables and fruits in health and in decreasing the risk of certain diseases has been attributed to the major carotenoids, β-carotene, lycopene, lutein, zeaxanthin, crocin (/crocetin) and curcumin, due to their antioxidant effects. It is thought that carotenoids act in a time- and dose-dependent manner. In this review, we briefly describe the biological and immunological activities of the main carotenoids used for the treatment of various diseases and their possible mechanisms of action. This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc. © 2016 The British Pharmacological Society.

Inhibition of Wnt Signaling Pathways Impairs Chlamydia trachomatis Infection in Endometrial Epithelial Cells.

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Kintner, Jennifer; Moore, Cheryl G; Whittimore, Judy D; Butler, Megan; Hall, Jennifer V

2017-01-01

Chlamydia trachomatis infections represent the predominant cause of bacterial sexually transmitted infections. As an obligate intracellular bacterium, C. trachomatis is dependent on the host cell for survival, propagation, and transmission. Thus, factors that affect the host cell, including nutrition, cell cycle, and environmental signals, have the potential to impact chlamydial development. Previous studies have demonstrated that activation of Wnt/β-catenin signaling benefits C. trachomatis infections in fallopian tube epithelia. In cervical epithelial cells chlamydiae sequester β-catenin within the inclusion. These data indicate that chlamydiae interact with the Wnt signaling pathway in both the upper and lower female genital tract (FGT). However, hormonal activation of canonical and non-canonical Wnt signaling pathways is an essential component of cyclic remodeling in another prominent area of the FGT, the endometrium. Given this information, we hypothesized that Wnt signaling would impact chlamydial infection in endometrial epithelial cells. To investigate this hypothesis, we analyzed the effect of Wnt inhibition on chlamydial inclusion development and elementary body (EB) production in two endometrial cell lines, Ishikawa (IK) and Hec-1B, in nonpolarized cell culture and in a polarized endometrial epithelial (IK)/stromal (SHT-290) cell co-culture model. Inhibition of Wnt by the small molecule inhibitor (IWP2) significantly decreased inclusion size in IK and IK/SHT-290 cultures ( p Wnt inhibition caused chlamydiae to become aberrant in morphology. EB formation was also impaired in IK, Hec-1B and IK/SHT-290 cultures regardless of whether Wnt inhibition occurred throughout, in the middle (24 hpi) or late (36 hpi) during the development cycle. Overall, these data lead us to conclude that Wnt signaling in the endometrium is a key host pathway for the proper development of C. trachomatis .

Dual TORK/DNA-PK inhibition blocks critical signaling pathways in chronic lymphocytic leukemia

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Thijssen, Rachel; ter Burg, Johanna; Garrick, Brett; van Bochove, Gregor G. W.; Brown, Jennifer R.; Fernandes, Stacey M.; Rodríguez, María Solé; Michot, Jean-Marie; Hallek, Michael; Eichhorst, Barbara; Reinhardt, Hans Christian; Bendell, Johanna; Derks, Ingrid A. M.; van Kampen, Roel J. W.; Hege, Kristen; Kersten, Marie José; Trowe, Torsten; Filvaroff, Ellen H.; Eldering, Eric; Kater, Arnon P.

2016-01-01

Inhibition of B-cell receptor (BCR) signaling pathways in chronic lymphocytic leukemia (CLL) provides significant clinical benefit to patients, mainly by blocking adhesion of CLL cells in the lymph node microenvironment. The currently applied inhibitors ibrutinib and idelalisib have limited capacity

Calcium-sensing receptor (CaSR): pharmacological properties and signaling pathways.

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Conigrave, Arthur D; Ward, Donald T

2013-06-01

In this article we consider the mechanisms by which the calcium-sensing receptor (CaSR) induces its cellular responses via the control (activation or inhibition) of signaling pathways. We consider key features of CaSR-mediated signaling including its control of the heterotrimeric G-proteins Gq/11, Gi/o and G12/13 and the downstream consequences recognizing that very few CaSR-mediated cell phenomena have been fully described. We also consider the manner in which the CaSR contributes to the formation of specific signaling scaffolds via peptide recognition sequences in its intracellular C-terminal along with the origins of its high level of cooperativity, particularly for Ca(2+)o, and its remarkable resistance to desensitization. We also consider the nature of the mechanisms by which the CaSR controls oscillatory and sustained Ca(2+)i mobilizing responses and inhibits or elevates cyclic adenosine monophosphate (cAMP) levels dependent on the cellular and signaling context. Finally, we consider the diversity of the receptor's ligands, ligand binding sites and broader compartment-dependent physiological roles leading to the identification of pronounced ligand-biased signaling for agonists including Sr(2+) and modulators including l-amino acids and the clinically effective calcimimetic cinacalcet. We note the implications of these findings for the development of new designer drugs that might target the CaSR in pathophysiological contexts beyond those established for the treatment of disorders of calcium metabolism. Copyright © 2013 Elsevier Ltd. All rights reserved.

Regulation of the Nampt-mediated NAD salvage pathway and its therapeutic implications in pancreatic cancer.

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Ju, Huai-Qiang; Zhuang, Zhuo-Nan; Li, Hao; Tian, Tian; Lu, Yun-Xin; Fan, Xiao-Qiang; Zhou, Hai-Jun; Mo, Hai-Yu; Sheng, Hui; Chiao, Paul J; Xu, Rui-Hua

2016-08-28

Nicotinamide adenine dinucleotide (NAD) is a crucial cofactor for the redox reactions in the metabolic pathways of cancer cells that have elevated aerobic glycolysis (Warburg effect). Cancer cells are reported to rely on NAD recycling and inhibition of the NAD salvage pathway causes metabolic collapse and cell death. However, the underlying regulatory mechanisms and clinical implications for the NAD salvage pathway in pancreatic ductal adenocarcinoma (PDAC) remain unclear. This study showed that the expression of Nampt, the rate-limiting enzyme of the NAD salvage pathway, was significantly increased in PDAC cells and PDAC tissues. Additionally, inhibition of Nampt impaired tumor growth in vitro and tumorigenesis in vivo, which was accompanied by a decreased cellular NAD level and glycolytic activity. Mechanistically, the Nampt expression was independent of Kras and p16 status, but it was directly regulated by miR-206, which was inversely correlated with the expression of Nampt in PDAC tissues. Importantly, pharmacological inhibition of Nampt by its inhibitor, FK866, significantly enhanced the antitumor activity of gemcitabine in PDAC cells and in orthotopic xenograft mouse models. In conclusion, the present study revealed a novel regulatory mechanism for Nampt in PDAC and suggested that Nampt inhibition may override gemcitabine resistance by decreasing the NAD level and suppressing glycolytic activity, warranting further clinical investigation for pancreatic cancer treatment. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Combined EGFR and VEGFR versus single EGFR signaling pathways inhibition therapy for NSCLC: a systematic review and meta-analysis.

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Xinji Zhang

Full Text Available BACKGROUND: Lung cancer is a heterogeneous disease with multiple signaling pathways influencing tumor cell survival and proliferation, and it is likely that blocking only one of these pathways allows others to act as salvage or escape mechanisms for cancer cells. Whether combined inhibition therapy has greater anti-tumor activity than single inhibition therapy is a matter of debate. Hence, a meta-analysis comparing therapy inhibiting both VEGFR and EGFR signaling pathways with that inhibiting EGFR signaling pathway alone was performed. METHODOLOGY AND PRINCIPAL FINDINGS: We searched PubMed, EMBASE database and the proceedings of major conferences for relevant clinical trials. Outcomes analyzed were objective tumor response rate (ORR, progression-free survival (PFS, overall survival (OS and toxicity. Besides, subgroup analyses were performed to investigate whether the combined inhibition therapy is best performed using combination of selective agents or a single agent with multiple targets. Six trials recruiting 3,302 patients were included in the analysis. Combined inhibition therapy was associated with a 3% improvement in OS as compared with single-targeted therapy, but this difference was not statistically significant (HR, 0.97; 95% CI, 0.89-1.05; P=0.472. Patients receiving combined inhibition therapy had significant longer PFS than the group with single-targeted therapy (HR, 0.80; 95% CI, 0.67-0.95; P=0.011. There was no difference in the ORR between the groups (OR, 1.44; 95% CI, 0.95-2.18; P=0.085. Subgroup analysis revealed that combined inhibition therapy using combination regimens was associated with statistically significant improvement in both ORR and PFS. Toxicity was greater in combined inhibition therapy. CONCLUSIONS: There is no evidence to support the use of combined inhibition therapy in unselected patients with advanced NSCLC. However, given the significant advantage in ORR and PFS, combined inhibition therapy using combination

Preventive Effects of Velvet Antler (Cervus elaphus against Lipopolysaccharide-Induced Acute Lung Injury in Mice by Inhibiting MAPK/NF-κB Activation and Inducing AMPK/Nrf2 Pathways

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Jui-Shu Chang

2018-01-01

Full Text Available Velvet antler (Cervus elaphus is a typical traditional animal medicine. It is considered to have various pharmacological effects including stimulation of the immune system, increase in the physical strength, and enhancement of sexual function. This paper aims to investigate the aqueous extract of velvet antler (AVA in the mouse models of LPS-induced ALI. Inhibition of NO, TNF-α, IL-1β, IL-6, and IL-10 productions contributes to the attenuation of LPS-induced lung inflammation by AVA. A 5-day pretreatment of AVA prevented histological alterations and enhanced antioxidant enzyme activity in lung tissues. AVA significantly reduced the material (total number of cells and proteins in the BALF. Western blot analysis revealed that the expression of iNOS and COX-2 and phosphorylation of IκB-α and MAPKs proteins are blocked in LPS-stimulated macrophages as well as LPS-induced lung injury in mice. Consistent with this concept, the phosphorylation of CaMKKβ, LKB1, AMPK, Nrf2, and HO-1 was activated after AVA treatment. The results from this study indicate AVA has anti-inflammatory effects in vivo and AVA is a potential model for the development of health food. In addition, its pathways may be at least partially associated with inhibiting MAPK/NF-κB activation and upregulating AMPK/Nrf2 pathways and the regulation of antioxidant enzyme activity.

Oridonin attenuates Aβ1-42-induced neuroinflammation and inhibits NF-κB pathway.

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Sulei Wang

Full Text Available Neuroinflammation induced by beta-amyloid (Aβ plays a critical role in the pathogenesis of Alzheimer's disease (AD, and inhibiting Aβ-induced neuroinflammation serves as a potential strategy for the treatment of AD. Oridonin (Ori, a compound of Rabdosia rubescens, has been shown to exert anti-inflammatory effects. In this study, we demonstrated that Ori inhibited glial activation and decreased the release of inflammatory cytokines in the hippocampus of Aβ1-42-induced AD mice. In addition, Ori inhibited the NF-κB pathway and Aβ1-42-induced apoptosis. Furthermore, Ori could attenuate memory deficits in Aβ1-42-induced AD mice. In conclusion, our study demonstrated that Ori inhibited the neuroinflammation and attenuated memory deficits induced by Aβ1-42, suggesting that Ori might be a promising candidate for AD treatment.

Cancer Therapy Targeting the HER2-PI3K Pathway: Potential Impact on the Heart

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Giannoula Lakka Klement

2012-06-01

Full Text Available The HER2-PI3K pathway is the one of the most mutated pathways in cancer. Several drugs targeting the major kinases of this pathway have been approved by the Food and Drug Administration and many are being tested in clinical trials for the treatment of various cancers. However, the HER2-PI3K pathway is also pivotal for maintaining the physiological function of the heart, especially in the presence of cardiac stress. Clinical studies have shown that in patients treated with doxorubicin concurrently with Trastuzumab, a monoclonal antibody that blocks the HER2 receptor, the New York Heart Association class III/IV heart failure was significantly increased compared to those who were treated with doxorubicin alone (16 vs. 3%. Studies in transgenic mice have also shown that other key kinases of this pathway, such as PI3Kα, PDK1, Akt and mTOR, are important for protecting the heart from ischemia-reperfusion and aortic stenosis induced cardiac dysfunction. Studies, however, have also shown that inhibition of PI3Kγ improve cardiac function of a failing heart. In addition, results from transgenic mouse models are not always consistent with the outcome of the pharmacological inhibition of this pathway. Here, we will review these findings and discuss how we can address the cardiac side-effects caused by inhibition of this important pathway in both cancer and cardiac biology.

A genetic and pharmacological analysis of isoprenoid pathway by LC-MS/MS in fission yeast.

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Tomonori Takami

Full Text Available Currently, statins are the only drugs acting on the mammalian isoprenoid pathway. The mammalian genes in this pathway are not easily amenable to genetic manipulation. Thus, it is difficult to study the effects of the inhibition of various enzymes on the intermediate and final products in the isoprenoid pathway. In fission yeast, antifungal compounds such as azoles and terbinafine are available as inhibitors of the pathway in addition to statins, and various isoprenoid pathway mutants are also available. Here in these mutants, treated with statins or antifungals, we quantified the final and intermediate products of the fission yeast isoprenoid pathway using liquid chromatography-mass spectrometry/mass spectrometry. In hmg1-1, a mutant of the gene encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR, ergosterol (a final sterol product, and squalene (an intermediate pathway product, were decreased to approximately 80% and 10%, respectively, compared with that of wild-type cells. Consistently in wild-type cells, pravastatin, an HMGR inhibitor decreased ergosterol and squalene, and the effect was more pronounced on squalene. In hmg1-1 mutant and in wild-type cells treated with pravastatin, the decrease in the levels of farnesyl pyrophosphate and geranylgeranyl pyrophosphate respectively was larger than that of ergosterol but was smaller than that of squalene. In Δerg6 or Δsts1 cells, mutants of the genes involved in the last step of the pathway, ergosterol was not detected, and the changes of intermediate product levels were distinct from that of hmg1-1 mutant. Notably, in wild-type cells miconazole and terbinafine only slightly decreased ergosterol level. Altogether, these studies suggest that the pleiotropic phenotypes caused by the hmg1-1 mutation and pravastatin might be due to decreased levels of isoprenoid pyrophosphates or other isoprenoid pathway intermediate products rather than due to a decreased ergosterol level.

Inhibition of the Ras-Net (Elk-3) pathway by a novel pyrazole that affects microtubules.

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Wasylyk, Christine; Zheng, Hong; Castell, Christelle; Debussche, Laurent; Multon, Marie-Christine; Wasylyk, Bohdan

2008-03-01

Net (Elk-3/SAP-2/Erp) is a transcription factor that is phosphorylated and activated by the Ras-extracellular signal-regulated kinase (Erk) signaling pathway and is involved in wound healing, angiogenesis, and tumor growth. In a cell-based screen for small molecule inhibitors of Ras activation of Net transcriptional activity, we identified a novel pyrazole, XRP44X. XRP44X inhibits fibroblast growth factor 2 (FGF-2)-induced Net phosphorylation by the Ras-Erk signaling upstream from Ras. It also binds to the colchicine-binding site of tubulin, depolymerizes microtubules, stimulates cell membrane blebbing, and affects the morphology of the actin skeleton. Interestingly, Combretastin-A4, which produces similar effects on the cytoskeleton, also inhibits FGF-2 Ras-Net signaling. This differs from other classes of agents that target microtubules, which have either little effect (vincristine) or no effect (docetaxel and nocodazole) on the Ras-Net pathway. XRP44X inhibits various cellular properties, including cell growth, cell cycle progression, and aortal sprouting, similar to other molecules that bind to the tubulin colchicine site. XRP44X has the potentially interesting property of connecting two important pathways involved in cell transformation and may thereby represent an interesting class of molecules that could be developed for cancer treatment.

Borna disease virus nucleoprotein inhibits type I interferon induction through the interferon regulatory factor 7 pathway

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Song, Wuqi; Kao, Wenping; Zhai, Aixia; Qian, Jun; Li, Yujun; Zhang, Qingmeng; Zhao, Hong; Hu, Yunlong; Li, Hui; Zhang, Fengmin

2013-01-01

Highlights: •IRF7 nuclear localisation was inhibited by BDV persistently infected. •BDV N protein resistant to IFN induction both in BDV infected OL cell and N protein plasmid transfected OL cell. •BDV N protein is related to the inhibition of IRF7 nuclear localisation. -- Abstract: The expression of type I interferon (IFN) is one of the most potent innate defences against viral infection in higher vertebrates. Borna disease virus (BDV) establishes persistent, noncytolytic infections in animals and in cultured cells. Early studies have shown that the BDV phosphoprotein can inhibit the activation of type I IFN through the TBK1–IRF3 pathway. The function of the BDV nucleoprotein in the inhibition of IFN activity is not yet clear. In this study, we demonstrated IRF7 activation and increased IFN-α/β expression in a BDV-persistently infected human oligodendroglia cell line following RNA interference-mediated BDV nucleoprotein silencing. Furthermore, we showed that BDV nucleoprotein prevented the nuclear localisation of IRF7 and inhibited endogenous IFN induction by poly(I:C), coxsackie virus B3 and IFN-β. Our findings provide evidence for a previously undescribed mechanism by which the BDV nucleoprotein inhibits type I IFN expression by interfering with the IRF7 pathway

All-trans retinoic acid promotes neural lineage entry by pluripotent embryonic stem cells via multiple pathways

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Fang Bo

2009-07-01

Full Text Available Abstract Background All-trans retinoic acid (RA is one of the most important morphogens with pleiotropic actions. Its embryonic distribution correlates with neural differentiation in the developing central nervous system. To explore the precise effects of RA on neural differentiation of mouse embryonic stem cells (ESCs, we detected expression of RA nuclear receptors and RA-metabolizing enzymes in mouse ESCs and investigated the roles of RA in adherent monolayer culture. Results Upon addition of RA, cell differentiation was directed rapidly and exclusively into the neural lineage. Conversely, pharmacological interference with RA signaling suppressed this neural differentiation. Inhibition of fibroblast growth factor (FGF signaling did not suppress significantly neural differentiation in RA-treated cultures. Pharmacological interference with extracellular signal-regulated kinase (ERK pathway or activation of Wnt pathway effectively blocked the RA-promoted neural specification. ERK phosphorylation was enhanced in RA-treated cultures at the early stage of differentiation. Conclusion RA can promote neural lineage entry by ESCs in adherent monolayer culture systems. This effect depends on RA signaling and its crosstalk with the ERK and Wnt pathways.

Repaglinide-gemfibrozil drug interaction: inhibition of repaglinide glucuronidation as a potential additional contributing mechanism.

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Gan, Jinping; Chen, Weiqi; Shen, Hong; Gao, Ling; Hong, Yang; Tian, Yuan; Li, Wenying; Zhang, Yueping; Tang, Yuwei; Zhang, Hongjian; Humphreys, William Griffith; Rodrigues, A David

2010-12-01

To further explore the mechanism underlying the interaction between repaglinide and gemfibrozil, alone or in combination with itraconazole. Repaglinide metabolism was assessed in vitro (human liver subcellular fractions, fresh human hepatocytes, and recombinant enzymes) and the resulting incubates were analyzed, by liquid chromatography-mass spectrometry (LC-MS) and radioactivity counting, to identify and quantify the different metabolites therein. Chemical inhibitors, in addition to a trapping agent, were also employed to elucidate the importance of each metabolic pathway. Finally, a panel of human liver microsomes (genotyped for UGT1A1*28 allele status) was used to determine the importance of UGT1A1 in the direct glucuronidation of repaglinide. The results of the present study demonstrate that repaglinide can undergo direct glucuronidation, a pathway that can possibly contribute to the interaction with gemfibrozil. For example, [³H]-repaglinide formed glucuronide and oxidative metabolites (M2 and M4) when incubated with primary human hepatocytes. Gemfibrozil effectively inhibited (∼78%) both glucuronide and M4 formation, but had a minor effect on M2 formation. Concomitantly, the overall turnover of repaglinide was also inhibited (∼80%), and was completely abolished when gemfibrozil was co-incubated with itraconazole. These observations are in qualitative agreement with the in vivo findings. UGT1A1 plays a significant role in the glucuronidation of repaglinide. In addition, gemfibrozil and its glucuronide inhibit repaglinide glucuronidation and the inhibition by gemfibrozil glucuronide is time-dependent. Inhibition of UGT enzymes, especially UGT1A1, by gemfibrozil and its glucuronide is an additional mechanism to consider when rationalizing the interaction between repaglinide and gemfibrozil. © 2010 The Authors. British Journal of Clinical Pharmacology © 2010 The British Pharmacological Society.

FXR blocks the growth of liver cancer cells through inhibiting mTOR-s6K pathway

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Huang, Xiongfei, E-mail: xiongfeihuang@hotmail.com [Department of Pathology and Institute of Oncology, Preclinical School, Fujian Medical University, Fuzhou 350108, Fujian (China); Key Laboratory of Ministry of Education for Gastrointestinal Cancer, Fujian Medical University, Fuzhou 350108, Fujian (China); Zeng, Yeting [Department of Pathology and Institute of Oncology, Preclinical School, Fujian Medical University, Fuzhou 350108, Fujian (China); Wang, Xinrui [Department of Biochemistry and Molecular Biology, Fujian Medical University, Fuzhou 350108, Fujian (China); Ma, Xiaoxiao [Department of Diabetes Complications and Metabolism, Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, CA 91010 (United States); Li, Qianqian; Li, Ningbo; Su, Hongying [Department of Pathology and Institute of Oncology, Preclinical School, Fujian Medical University, Fuzhou 350108, Fujian (China); Huang, Wendong [Department of Diabetes Complications and Metabolism, Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, CA 91010 (United States)

2016-05-27

The nuclear receptor Farnesoid X Receptor (FXR) is likely a tumor suppressor in liver tissue but its molecular mechanism of suppression is not well understood. In this study, the gene expression profile of human liver cancer cells was investigated by microarray. Bioinformatics analysis of these data revealed that FXR might regulate the mTOR/S6K signaling pathway. This was confirmed by altering the expression level of FXR in liver cancer cells. Overexpression of FXR prevented the growth of cells and induced cell cycle arrest, which was enhanced by the mTOR/S6K inhibitor rapamycin. FXR upregulation also intensified the inhibition of cell growth by rapamycin. Downregulation of FXR produced the opposite effect. Finally, we found that ectopic expression of FXR in SK-Hep-1 xenografts inhibits tumor growth and reduces expression of the phosphorylated protein S6K. Taken together, our data provide the first evidence that FXR suppresses proliferation of human liver cancer cells via the inhibition of the mTOR/S6K signaling pathway. FXR expression can be used as a biomarker of personalized mTOR inhibitor treatment assessment for liver cancer patients. -- Highlights: •FXR inhibits the proliferation of liver cancer cells by prolonging G0/G1 phase. •Microarray results indicate that mTOR-S6k signaling is involved in cellular processes in which FXR plays an important role. •FXR blocks the growth of liver cancer cells via the inhibition of the mTOR/S6K signaling pathway in vitro and in vivo.

FXR blocks the growth of liver cancer cells through inhibiting mTOR-s6K pathway

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Huang, Xiongfei; Zeng, Yeting; Wang, Xinrui; Ma, Xiaoxiao; Li, Qianqian; Li, Ningbo; Su, Hongying; Huang, Wendong

2016-01-01

The nuclear receptor Farnesoid X Receptor (FXR) is likely a tumor suppressor in liver tissue but its molecular mechanism of suppression is not well understood. In this study, the gene expression profile of human liver cancer cells was investigated by microarray. Bioinformatics analysis of these data revealed that FXR might regulate the mTOR/S6K signaling pathway. This was confirmed by altering the expression level of FXR in liver cancer cells. Overexpression of FXR prevented the growth of cells and induced cell cycle arrest, which was enhanced by the mTOR/S6K inhibitor rapamycin. FXR upregulation also intensified the inhibition of cell growth by rapamycin. Downregulation of FXR produced the opposite effect. Finally, we found that ectopic expression of FXR in SK-Hep-1 xenografts inhibits tumor growth and reduces expression of the phosphorylated protein S6K. Taken together, our data provide the first evidence that FXR suppresses proliferation of human liver cancer cells via the inhibition of the mTOR/S6K signaling pathway. FXR expression can be used as a biomarker of personalized mTOR inhibitor treatment assessment for liver cancer patients. -- Highlights: •FXR inhibits the proliferation of liver cancer cells by prolonging G0/G1 phase. •Microarray results indicate that mTOR-S6k signaling is involved in cellular processes in which FXR plays an important role. •FXR blocks the growth of liver cancer cells via the inhibition of the mTOR/S6K signaling pathway in vitro and in vivo.

Tryptophan-2,3-dioxygenase (TDO) inhibition ameliorates neurodegeneration by modulation of kynurenine pathway metabolites.

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Breda, Carlo; Sathyasaikumar, Korrapati V; Sograte Idrissi, Shama; Notarangelo, Francesca M; Estranero, Jasper G; Moore, Gareth G L; Green, Edward W; Kyriacou, Charalambos P; Schwarcz, Robert; Giorgini, Flaviano

2016-05-10

Metabolites of the kynurenine pathway (KP) of tryptophan (TRP) degradation have been closely linked to the pathogenesis of several neurodegenerative disorders. Recent work has highlighted the therapeutic potential of inhibiting two critical regulatory enzymes in this pathway-kynurenine-3-monooxygenase (KMO) and tryptophan-2,3-dioxygenase (TDO). Much evidence indicates that the efficacy of KMO inhibition arises from normalizing an imbalance between neurotoxic [3-hydroxykynurenine (3-HK); quinolinic acid (QUIN)] and neuroprotective [kynurenic acid (KYNA)] KP metabolites. However, it is not clear if TDO inhibition is protective via a similar mechanism or if this is instead due to increased levels of TRP-the substrate of TDO. Here, we find that increased levels of KYNA relative to 3-HK are likely central to the protection conferred by TDO inhibition in a fruit fly model of Huntington's disease and that TRP treatment strongly reduces neurodegeneration by shifting KP flux toward KYNA synthesis. In fly models of Alzheimer's and Parkinson's disease, we provide genetic evidence that inhibition of TDO or KMO improves locomotor performance and ameliorates shortened life span, as well as reducing neurodegeneration in Alzheimer's model flies. Critically, we find that treatment with a chemical TDO inhibitor is robustly protective in these models. Consequently, our work strongly supports targeting of the KP as a potential treatment strategy for several major neurodegenerative disorders and suggests that alterations in the levels of neuroactive KP metabolites could underlie several therapeutic benefits.

Curcumin inhibits bladder cancer stem cells by suppressing Sonic Hedgehog pathway.

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Wang, Dengdian; Kong, Xiaochuan; Li, Yuan; Qian, Weiwei; Ma, Jiaxing; Wang, Daming; Yu, Dexin; Zhong, Caiyun

2017-11-04

Cancer stem cells (CSCs) is responsible for the recurrence of human cancers. Thus, targeting CSCs is considered to be a valid way for human cancer treatment. Curcumin is a major component of phytochemicals that exerts potent anticancer activities. However, the effect of curcumin on bladder cancer stem cells (BCSCs) remains to be elucidated. In this study, we investigated the mechanism of curcumin suppressing bladder cancer stem cells. In this study, UM-UC-3 and EJ cells were cultured in serum-free medium (SFM) to form cell spheres that was characterized as BCSCs. Then cell spheres were separately treated with different concentrations of curcumin and purmorphamine. Cell cycle analysis were used to determine the percentage of cells in different phases. Western blot and quantitative real-time PCR analysis were used to detect the expression of relative molecules. Immunofluorescence staining analysis were also utilized to measure the protein level of CD44. We found that CSC markers, including CD44, CD133, ALDH1-A1, OCT-4 and Nanog, were obviously highly expressed in cell spheres. Moreover, we observed that curcumin reduced the cell spheres formation, decreased the expression of CSC markers, suppressed cell proliferation and induced cell apoptosis. We also found that curcumin inhibited the activation of Shh pathway, while the inhibitory effects of curcumin on BCSCs could be weakened by upregulation of Sonic Hedgehog (Shh) pathway. Altogether, these data suggested that curcumin inhibited the activities of BCSCs through suppressing Shh pathway, which might be an effective chemopreventive agent for bladder cancer intervention. Copyright © 2017. Published by Elsevier Inc.

APC Inhibits Ligand-Independent Wnt Signaling by the Clathrin Endocytic Pathway.

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Saito-Diaz, Kenyi; Benchabane, Hassina; Tiwari, Ajit; Tian, Ai; Li, Bin; Thompson, Joshua J; Hyde, Annastasia S; Sawyer, Leah M; Jodoin, Jeanne N; Santos, Eduardo; Lee, Laura A; Coffey, Robert J; Beauchamp, R Daniel; Williams, Christopher S; Kenworthy, Anne K; Robbins, David J; Ahmed, Yashi; Lee, Ethan

2018-03-12

Adenomatous polyposis coli (APC) mutations cause Wnt pathway activation in human cancers. Current models for APC action emphasize its role in promoting β-catenin degradation downstream of Wnt receptors. Unexpectedly, we find that blocking Wnt receptor activity in APC-deficient cells inhibits Wnt signaling independently of Wnt ligand. We also show that inducible loss of APC is rapidly followed by Wnt receptor activation and increased β-catenin levels. In contrast, APC2 loss does not promote receptor activation. We show that APC exists in a complex with clathrin and that Wnt pathway activation in APC-deficient cells requires clathrin-mediated endocytosis. Finally, we demonstrate conservation of this mechanism in Drosophila intestinal stem cells. We propose a model in which APC and APC2 function to promote β-catenin degradation, and APC also acts as a molecular "gatekeeper" to block receptor activation via the clathrin pathway. Copyright © 2018 Elsevier Inc. All rights reserved.

Saw Palmetto Extract Inhibits Metastasis and Antiangiogenesis through STAT3 Signal Pathway in Glioma Cell.

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Ding, Hong; Shen, Jinglian; Yang, Yang; Che, Yuqin

2015-01-01

Signal transducer and activator of transcription factor 3 (STAT3) plays an important role in the proliferation and angiogenesis in human glioma. Previous research indicated that saw palmetto extract markedly inhibited the proliferation of human glioma cells through STAT3 signal pathway. But its effect on tumor metastasis and antiangiogenesis is not clear. This study is to further clear the impact of saw palmetto extract on glioma cell metastasis, antiangiogenesis, and its mechanism. TUNEL assay indicated that the apoptotic cells in the saw palmetto treated group are higher than that in the control group (p saw palmetto extract inhibits the proliferation of human glioma. Meanwhile pSTAT3 is lower in the experimental group and CD34 is also inhibited in the saw palmetto treated group. This means that saw palmetto extract could inhibit the angiogenesis in glioma. We found that saw palmetto extract was an important phytotherapeutic drug against the human glioma through STAT3 signal pathway. Saw palmetto extract may be useful as an adjunctive therapeutic agent for treatment of individuals with glioma and other types of cancer in which STAT3 signaling is activated.

AS101 prevents diabetic nephropathy progression and mesangial cell dysfunction: regulation of the AKT downstream pathway.

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Itay Israel Shemesh

Full Text Available Diabetic nephropathy (DN is characterized by proliferation of mesangial cells, mesangial expansion, hypertrophy and extracellular matrix accumulation. Previous data have cross-linked PKB (AKT to TGFβ induced matrix modulation. The non-toxic compound AS101 has been previously shown to favorably affect renal pathology in various animal models and inhibits AKT activity in leukemic cells. Here, we studied the pharmacological properties of AS101 against the progression of rat DN and high glucose-induced mesangial dysfunction. In-vivo administration of AS101 to Streptozotocin injected rats didn't decreased blood glucose levels but ameliorated kidney hypotrophy, proteinuria and albuminuria and downregulated cortical kidney phosphorylation of AKT, GSK3β and SMAD3. AS101 treatment of primary rat glomerular mesangial cells treated with high glucose significantly reduced their elevated proliferative ability, as assessed by XTT assay and cell cycle analysis. This reduction was associated with decreased levels of p-AKT, increased levels of PTEN and decreased p-GSK3β and p-FoxO3a expression. Pharmacological inhibition of PI3K, mTORC1 and SMAD3 decreased HG-induced collagen accumulation, while inhibition of GSK3β did not affect its elevated levels. AS101 also prevented HG-induced cell growth correlated to mTOR and (rpS6 de-phosphorylation. Thus, pharmacological inhibition of the AKT downstream pathway by AS101 has clinical potential in alleviating the progression of diabetic nephropathy.

Kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis of apolipoprotein E deficient mice

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Xiao, Hong-Bo; Lu, Xiang-Yang; Sun, Zhi-Liang; Zhang, Heng-Bo

2011-01-01

Recent studies show that osteopontin (OPN) and its receptor cluster of differentiation 44 (CD44) are two pro-inflammatory cytokines contributing to the development of atherosclerosis. The objective of this study was to explore the inhibitory effect of kaempferol, a naturally occurring flavonoid compound, on atherogenesis and the mechanisms involved. The experiments were performed in aorta and plasma from C57BL/6J control and apolipoprotein E-deficient (ApoE −/− ) mice treated or not with kaempferol (50 or 100 mg/kg, intragastrically) for 4 weeks. Kaempferol treatment decreased atherosclerotic lesion area, improved endothelium-dependent vasorelaxation, and increased the maximal relaxation value concomitantly with decrease in the half-maximum effective concentration, plasma OPN level, aortic OPN expression, and aortic CD44 expression in ApoE −/− mice. In addition, treatment with kaempferol also significantly decreased reactive oxygen species production in mice aorta. The present results suggest that kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis of ApoE −/− mice. -- Graphical abstract: Kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis of ApoE −/− mice. Highlights: ► OPN–CD44 pathway plays a critical role in the development of atherosclerosis. ► We examine lesion area, OPN and CD44 changes after kaempferol treatment. ► Kaempferol treatment decreased atherosclerotic lesion area in ApoE −/− mice. ► Kaempferol treatment decreased aortic OPN and CD44 expressions in ApoE −/− mice. ► Kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis.

Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of apolipoprotein E deficient mice

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Xiao, Hong-Bo, E-mail: xhbzhb@yahoo.com [College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128 (China); Lu, Xiang-Yang; Sun, Zhi-Liang [Hunan Agricultural University, Changsha 410128 (China); Zhang, Heng-Bo [Furong District Red Cross Hospital, Changsha 410126 (China)

2011-12-15

Recent studies show that osteopontin (OPN) and its receptor cluster of differentiation 44 (CD44) are two pro-inflammatory cytokines contributing to the development of atherosclerosis. The objective of this study was to explore the inhibitory effect of kaempferol, a naturally occurring flavonoid compound, on atherogenesis and the mechanisms involved. The experiments were performed in aorta and plasma from C57BL/6J control and apolipoprotein E-deficient (ApoE{sup -/-}) mice treated or not with kaempferol (50 or 100 mg/kg, intragastrically) for 4 weeks. Kaempferol treatment decreased atherosclerotic lesion area, improved endothelium-dependent vasorelaxation, and increased the maximal relaxation value concomitantly with decrease in the half-maximum effective concentration, plasma OPN level, aortic OPN expression, and aortic CD44 expression in ApoE{sup -/-} mice. In addition, treatment with kaempferol also significantly decreased reactive oxygen species production in mice aorta. The present results suggest that kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of ApoE{sup -/-} mice. -- Graphical abstract: Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of ApoE{sup -/-} mice. Highlights: Black-Right-Pointing-Pointer OPN-CD44 pathway plays a critical role in the development of atherosclerosis. Black-Right-Pointing-Pointer We examine lesion area, OPN and CD44 changes after kaempferol treatment. Black-Right-Pointing-Pointer Kaempferol treatment decreased atherosclerotic lesion area in ApoE{sup -/-} mice. Black-Right-Pointing-Pointer Kaempferol treatment decreased aortic OPN and CD44 expressions in ApoE{sup -/-} mice. Black-Right-Pointing-Pointer Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis.

Histone deacetylases control neurogenesis in embryonic brain by inhibition of BMP2/4 signaling.

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Maya Shakèd

Full Text Available BACKGROUND: Histone-modifying enzymes are essential for a wide variety of cellular processes dependent upon changes in gene expression. Histone deacetylases (HDACs lead to the compaction of chromatin and subsequent silencing of gene transcription, and they have recently been implicated in a diversity of functions and dysfunctions in the postnatal and adult brain including ocular dominance plasticity, memory consolidation, drug addiction, and depression. Here we investigate the role of HDACs in the generation of neurons and astrocytes in the embryonic brain. PRINCIPAL FINDINGS: As a variety of HDACs are expressed in differentiating neural progenitor cells, we have taken a pharmacological approach to inhibit multiple family members. Inhibition of class I and II HDACs in developing mouse embryos with trichostatin A resulted in a dramatic reduction in neurogenesis in the ganglionic eminences and a modest increase in neurogenesis in the cortex. An identical effect was observed upon pharmacological inhibition of HDACs in in vitro-differentiating neural precursors derived from the same brain regions. A reduction in neurogenesis in ganglionic eminence-derived neural precursors was accompanied by an increase in the production of immature astrocytes. We show that HDACs control neurogenesis by inhibition of the bone morphogenetic protein BMP2/4 signaling pathway in radial glial cells. HDACs function at the transcriptional level by inhibiting and promoting, respectively, the expression of Bmp2 and Smad7, an intracellular inhibitor of BMP signaling. Inhibition of the BMP2/4 signaling pathway restored normal levels of neurogenesis and astrogliogenesis to both ganglionic eminence- and cortex-derived cultures in which HDACs were inhibited. CONCLUSIONS: Our results demonstrate a transcriptionally-based regulation of BMP2/4 signaling by HDACs both in vivo and in vitro that is critical for neurogenesis in the ganglionic eminences and that modulates cortical

Insulin utilizes the PI 3-kinase pathway to inhibit SP-A gene expression in lung epithelial cells

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Snyder Jeanne M

2002-10-01

Full Text Available Abstract Background It has been proposed that high insulin levels may cause delayed lung development in the fetuses of diabetic mothers. A key event in lung development is the production of adequate amounts of pulmonary surfactant. Insulin inhibits the expression of surfactant protein A (SP-A, the major surfactant-associated protein, in lung epithelial cells. In the present study, we investigated the signal transduction pathways involved in insulin inhibition of SP-A gene expression. Methods H441 cells, a human lung adenocarcinoma cell line, or human fetal lung explants were incubated with or without insulin. Transcription run-on assays were used to determine SP-A gene transcription rates. Northern blot analysis was used to examine the effect of various signal transduction inhibitors on SP-A gene expression. Immunoblot analysis was used to evaluate the levels and phosphorylation states of signal transduction protein kinases. Results Insulin decreased SP-A gene transcription in human lung epithelial cells within 1 hour. Insulin did not affect p44/42 mitogen-activated protein kinase (MAPK phosphorylation and the insulin inhibition of SP-A mRNA levels was not affected by PD98059, an inhibitor of the p44/42 MAPK pathway. In contrast, insulin increased p70 S6 kinase Thr389 phosphorylation within 15 minutes. Wortmannin or LY294002, both inhibitors of phosphatidylinositol 3-kinase (PI 3-kinase, or rapamycin, an inhibitor of the activation of p70 S6 kinase, a downstream effector in the PI 3-kinase pathway, abolished or attenuated the insulin-induced inhibition of SP-A mRNA levels. Conclusion Insulin inhibition of SP-A gene expression in lung epithelial cells probably occurs via the rapamycin-sensitive PI 3-kinase signaling pathway.

Fluocinolone acetonide partially restores the mineralization of LPS-stimulated dental pulp cells through inhibition of NF-κB pathway and activation of AP-1 pathway

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Liu, Zhongning; Jiang, Ting; Wang, Xinzhi; Wang, Yixiang

2013-01-01

BACKGROUND AND PURPOSE Fluocinolone acetonide (FA) is commonly used as a steroidal anti-inflammatory drug. We recently found that in dental pulp cells (DPCs) FA has osteo-/odonto-inductive as well as anti-inflammatory effects. However, the mechanism by which FA induces these effects in DPCs is poorly understood. EXPERIMENTAL APPROACH The effect of FA on the mineralization of DPCs during inflammatory conditions and the underlying mechanism were investigated by real-time PCR, Western blot, EMSA, histochemical staining, immunostaining and pathway blockade assays. KEY RESULTS FA significantly inhibited the inflammatory response in LPS-treated DPCs not only by down-regulating the expression of pro–inflammation-related genes, but also by up-regulating the expression of the anti-inflammatory gene PPAR-γ and mineralization-related genes. Moreover, histochemical staining and immunostaining showed that FA could partially restore the expressions of alkaline phosphatase, osteocalcin and dentin sialophosphoprotein (DSPP) and mineralization in LPS-stimulated DPCs. Real-time PCR and Western blot analysis revealed that FA up-regulated DSPP and runt-related transcription factor 2 expression by inhibiting the expression of phosphorylated-NF-κB P65 and activating activator protein-1 (AP-1) (p-c-Jun and Fra-1). These results were further confirmed through EMSA, by detection of NF-κB DNA-binding activity and pathway blockade assays using a NF-κB pathway inhibitor, AP-1 pathway inhibitor and glucocorticoid receptor antagonist. CONCLUSIONS AND IMPLICATIONS Inflammation induced by LPS suppresses the mineralization process in DPCs. FA partially restored this osteo-/odonto-genesis process in LPS-treated DPCs and had an anti-inflammatory effect through inhibition of the NF-κB pathway and activation of the AP-1 pathway. Hence, FA is a potential new treatment for inflammation-associated bone/teeth diseases. PMID:24024985

Dibenzocyclooctadiene lignans, gomisins J and N inhibit the Wnt/{beta}-catenin signaling pathway in HCT116 cells

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Kang, Kyungsu; Lee, Kyung-Mi; Yoo, Ji-Hye; Lee, Hee Ju [Functional Food Center, Korea Institute of Science and Technology, Gangneung 210-340 (Korea, Republic of); Kim, Chul Young [Functional Food Center, Korea Institute of Science and Technology, Gangneung 210-340 (Korea, Republic of); College of Pharmacy, Hanyang University, Ansan 426-791 (Korea, Republic of); Nho, Chu Won, E-mail: cwnho@kist.re.kr [Functional Food Center, Korea Institute of Science and Technology, Gangneung 210-340 (Korea, Republic of)

2012-11-16

Graphical abstract: Schematic diagram of the possible molecular mechanism underlying the inhibition of the Wnt/{beta}-catenin signaling pathway and the induction of G0/G1-phase arrest by gomisins J and N, derived from the fruits of S. chinensis, in HCT116 human colon cancer cells. Highlights: Black-Right-Pointing-Pointer Gomisins J and N inhibited Wnt/{beta}-catenin signaling pathway in HCT116 cells. Black-Right-Pointing-Pointer Gomisins J and N disrupted the binding of {beta}-catenin to specific DNA sequences, TBE. Black-Right-Pointing-Pointer Gomisins J and N inhibited the HCT116 cell proliferation through G0/G1 phase arrest. Black-Right-Pointing-Pointer Gomisins J and N inhibited the expression of Cyc D1, a Wnt/{beta}-catenin target gene. -- Abstract: Here, we report that gomisin J and gomisin N, dibenzocyclooctadiene type lignans isolated from Schisandra chinensis, inhibit Wnt/{beta}-catenin signaling in HCT116 cells. Gomisins J and N appear to inhibit Wnt/{beta}-catenin signaling by disrupting the interaction between {beta}-catenin and its specific target DNA sequences (TCF binding elements, TBE) rather than by altering the expression of the {beta}-catenin protein. Gomisins J and N inhibit HCT116 cell proliferation by arresting the cell cycle at the G0/G1 phase. The G0/G1 phase arrest induced by gomisins J and N appears to be caused by a decrease in the expression of Cyclin D1, a representative target gene of the Wnt/{beta}-catenin signaling pathway, as well as Cdk2, Cdk4, and E2F-1. Therefore, gomisins J and N, the novel Wnt/{beta}-catenin inhibitors discovered in this study, may serve as potential agents for the prevention and treatment of human colorectal cancers.

Dibenzocyclooctadiene lignans, gomisins J and N inhibit the Wnt/β-catenin signaling pathway in HCT116 cells

International Nuclear Information System (INIS)

Kang, Kyungsu; Lee, Kyung-Mi; Yoo, Ji-Hye; Lee, Hee Ju; Kim, Chul Young; Nho, Chu Won

2012-01-01

Graphical abstract: Schematic diagram of the possible molecular mechanism underlying the inhibition of the Wnt/β-catenin signaling pathway and the induction of G0/G1-phase arrest by gomisins J and N, derived from the fruits of S. chinensis, in HCT116 human colon cancer cells. Highlights: ► Gomisins J and N inhibited Wnt/β-catenin signaling pathway in HCT116 cells. ► Gomisins J and N disrupted the binding of β-catenin to specific DNA sequences, TBE. ► Gomisins J and N inhibited the HCT116 cell proliferation through G0/G1 phase arrest. ► Gomisins J and N inhibited the expression of Cyc D1, a Wnt/β-catenin target gene. -- Abstract: Here, we report that gomisin J and gomisin N, dibenzocyclooctadiene type lignans isolated from Schisandra chinensis, inhibit Wnt/β-catenin signaling in HCT116 cells. Gomisins J and N appear to inhibit Wnt/β-catenin signaling by disrupting the interaction between β-catenin and its specific target DNA sequences (TCF binding elements, TBE) rather than by altering the expression of the β-catenin protein. Gomisins J and N inhibit HCT116 cell proliferation by arresting the cell cycle at the G0/G1 phase. The G0/G1 phase arrest induced by gomisins J and N appears to be caused by a decrease in the expression of Cyclin D1, a representative target gene of the Wnt/β-catenin signaling pathway, as well as Cdk2, Cdk4, and E2F-1. Therefore, gomisins J and N, the novel Wnt/β-catenin inhibitors discovered in this study, may serve as potential agents for the prevention and treatment of human colorectal cancers.

[Lactobacillus rhamnosus GG conditioned medium prevents E. coli meningitis by inhibiting nuclear factor-κB pathway].

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Zeng, Qing; He, Xiao-Long; Xiao, Han-Sheng; DU, Lei; Li, Yu-Jing; Chen, Le-Cheng; Tian, Hui-Wen; Huang, Sheng-He; Cao, Hong

2017-01-20

To investigate whether Lactobacillus rhamnosus GG conditioned medium(LGG-CM)has preventive effect against E. coli K1-induced neuropathogenicity in vitro by inhibiting nuclear factor-κB (NF-κB) signaling pathway. An in vitro blood-brain barrier (BBB) model was constructed using human brain microvascular endothelial cells (HBMECs). The effect of LGG-CM on E. coli-actived NF-κB signaling pathway was assayed using Western blotting. Invasion assay and polymorphonuclear leukocyte (PMN) transmigration assay were performed to explore whether LGG-CM could inhibit E. coli invasion and PMN transmigration across the BBB in vitro. The expressions of ZO-1 and CD44 were detected using Western blotting and immunofluorescence. The changes of trans-epithelial electric resistance (TEER) and bacterial translocation were determined to evaluate the BBB permeability. Pre-treament with LGG-CM inhibited E. coli-activated NF-κB signaling pathway in HBMECs and decreased the invasion of E. coli K1 and transmigration of PMN. Western blotting showed that LGG-CM could alleviate E. coli-induced up-regulation of CD44 and down-regulation of ZO-1 expressions in HBMECs. In addition, pre-treatment with LGG-CM alleviated E. coli K1-induced reduction of TEER and suppressed bacterial translocation across the BBB in vitro. LGG-CM can block E. coli-induced activation of NF-κB signaling pathway and thereby prevents E. coli K1-induced neuropathogenicity by decreasing E. coli K1 invasion rates and PMN transmigration.

Nitazoxanide stimulates autophagy and inhibits mTORC1 signaling and intracellular proliferation of Mycobacterium tuberculosis.

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Karen K Y Lam

Full Text Available Tuberculosis, caused by Mycobacterium tuberculosis infection, is a major cause of morbidity and mortality in the world today. M. tuberculosis hijacks the phagosome-lysosome trafficking pathway to escape clearance from infected macrophages. There is increasing evidence that manipulation of autophagy, a regulated catabolic trafficking pathway, can enhance killing of M. tuberculosis. Therefore, pharmacological agents that induce autophagy could be important in combating tuberculosis. We report that the antiprotozoal drug nitazoxanide and its active metabolite tizoxanide strongly stimulate autophagy and inhibit signaling by mTORC1, a major negative regulator of autophagy. Analysis of 16 nitazoxanide analogues reveals similar strict structural requirements for activity in autophagosome induction, EGFP-LC3 processing and mTORC1 inhibition. Nitazoxanide can inhibit M. tuberculosis proliferation in vitro. Here we show that it inhibits M. tuberculosis proliferation more potently in infected human THP-1 cells and peripheral monocytes. We identify the human quinone oxidoreductase NQO1 as a nitazoxanide target and propose, based on experiments with cells expressing NQO1 or not, that NQO1 inhibition is partly responsible for mTORC1 inhibition and enhanced autophagy. The dual action of nitazoxanide on both the bacterium and the host cell response to infection may lead to improved tuberculosis treatment.

Nitazoxanide stimulates autophagy and inhibits mTORC1 signaling and intracellular proliferation of Mycobacterium tuberculosis.

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Lam, Karen K Y; Zheng, Xingji; Forestieri, Roberto; Balgi, Aruna D; Nodwell, Matt; Vollett, Sarah; Anderson, Hilary J; Andersen, Raymond J; Av-Gay, Yossef; Roberge, Michel

2012-01-01

Tuberculosis, caused by Mycobacterium tuberculosis infection, is a major cause of morbidity and mortality in the world today. M. tuberculosis hijacks the phagosome-lysosome trafficking pathway to escape clearance from infected macrophages. There is increasing evidence that manipulation of autophagy, a regulated catabolic trafficking pathway, can enhance killing of M. tuberculosis. Therefore, pharmacological agents that induce autophagy could be important in combating tuberculosis. We report that the antiprotozoal drug nitazoxanide and its active metabolite tizoxanide strongly stimulate autophagy and inhibit signaling by mTORC1, a major negative regulator of autophagy. Analysis of 16 nitazoxanide analogues reveals similar strict structural requirements for activity in autophagosome induction, EGFP-LC3 processing and mTORC1 inhibition. Nitazoxanide can inhibit M. tuberculosis proliferation in vitro. Here we show that it inhibits M. tuberculosis proliferation more potently in infected human THP-1 cells and peripheral monocytes. We identify the human quinone oxidoreductase NQO1 as a nitazoxanide target and propose, based on experiments with cells expressing NQO1 or not, that NQO1 inhibition is partly responsible for mTORC1 inhibition and enhanced autophagy. The dual action of nitazoxanide on both the bacterium and the host cell response to infection may lead to improved tuberculosis treatment.

Saw Palmetto Extract Inhibits Metastasis and Antiangiogenesis through STAT3 Signal Pathway in Glioma Cell

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Hong Ding

2015-01-01

Full Text Available Signal transducer and activator of transcription factor 3 (STAT3 plays an important role in the proliferation and angiogenesis in human glioma. Previous research indicated that saw palmetto extract markedly inhibited the proliferation of human glioma cells through STAT3 signal pathway. But its effect on tumor metastasis and antiangiogenesis is not clear. This study is to further clear the impact of saw palmetto extract on glioma cell metastasis, antiangiogenesis, and its mechanism. TUNEL assay indicated that the apoptotic cells in the saw palmetto treated group are higher than that in the control group (p<0.05. The apoptosis related protein is detected and the results revealed that saw palmetto extract inhibits the proliferation of human glioma. Meanwhile pSTAT3 is lower in the experimental group and CD34 is also inhibited in the saw palmetto treated group. This means that saw palmetto extract could inhibit the angiogenesis in glioma. We found that saw palmetto extract was an important phytotherapeutic drug against the human glioma through STAT3 signal pathway. Saw palmetto extract may be useful as an adjunctive therapeutic agent for treatment of individuals with glioma and other types of cancer in which STAT3 signaling is activated.

Arctigenin inhibits osteoclast differentiation and function by suppressing both calcineurin-dependent and osteoblastic cell-dependent NFATc1 pathways.

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Yamashita, Teruhito; Uehara, Shunsuke; Udagawa, Nobuyuki; Li, Feng; Kadota, Shigetoshi; Esumi, Hiroyasu; Kobayashi, Yasuhiro; Takahashi, Naoyuki

2014-01-01

Arctigenin, a lignan-derived compound, is a constituent of the seeds of Arctium lappa. Arctigenin was previously shown to inhibit osteoclastogenesis; however, this inhibitory mechanism has yet to be elucidated. Here, we showed that arctigenin inhibited the action of nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), a key transcription factor for osteoclastogenesis. NFATc1 in osteoclast precursors was activated through two distinct pathways: the calcineurin-dependent and osteoblastic cell-dependent pathways. Among the several lignan-derived compounds examined, arctigenin most strongly inhibited receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclast-like cell formation in mouse bone marrow macrophage (BMM) cultures, in which the calcineurin-dependent NFATc1 pathway was activated. Arctigenin suppressed neither the activation of nuclear factor κB and mitogen-activated protein kinases nor the up-regulation of c-Fos expression in BMMs treated with RANKL. However, arctigenin suppressed RANKL-induced NFATc1 expression. Interestingly, the treatment of osteoclast-like cells with arctigenin converted NFATc1 into a lower molecular weight species, which was translocated into the nucleus even in the absence of RANKL. Nevertheless, arctigenin as well as cyclosporin A (CsA), a calcineurin inhibitor, suppressed the NFAT-luciferase reporter activity induced by ionomycin and phorbol 12-myristate 13-acetate in BMMs. Chromatin immunoprecipitation analysis confirmed that arctigenin inhibited the recruitment of NFATc1 to the promoter region of the NFATc1 target gene. Arctigenin, but not CsA suppressed osteoclast-like cell formation in co-cultures of osteoblastic cells and bone marrow cells, in which the osteoblastic cell-dependent NFATc1 pathway was activated. The forced expression of constitutively active NFATc1 rescued osteoclastogenesis in BMM cultures treated with CsA, but not that treated with arctigenin. Arctigenin also suppressed the pit

Arctigenin Inhibits Osteoclast Differentiation and Function by Suppressing Both Calcineurin-Dependent and Osteoblastic Cell-Dependent NFATc1 Pathways

Science.gov (United States)

Yamashita, Teruhito; Uehara, Shunsuke; Udagawa, Nobuyuki; Li, Feng; Kadota, Shigetoshi; Esumi, Hiroyasu; Kobayashi, Yasuhiro; Takahashi, Naoyuki

2014-01-01

Arctigenin, a lignan-derived compound, is a constituent of the seeds of Arctium lappa. Arctigenin was previously shown to inhibit osteoclastogenesis; however, this inhibitory mechanism has yet to be elucidated. Here, we showed that arctigenin inhibited the action of nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), a key transcription factor for osteoclastogenesis. NFATc1 in osteoclast precursors was activated through two distinct pathways: the calcineurin-dependent and osteoblastic cell-dependent pathways. Among the several lignan-derived compounds examined, arctigenin most strongly inhibited receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclast-like cell formation in mouse bone marrow macrophage (BMM) cultures, in which the calcineurin-dependent NFATc1 pathway was activated. Arctigenin suppressed neither the activation of nuclear factor κB and mitogen-activated protein kinases nor the up-regulation of c-Fos expression in BMMs treated with RANKL. However, arctigenin suppressed RANKL-induced NFATc1 expression. Interestingly, the treatment of osteoclast-like cells with arctigenin converted NFATc1 into a lower molecular weight species, which was translocated into the nucleus even in the absence of RANKL. Nevertheless, arctigenin as well as cyclosporin A (CsA), a calcineurin inhibitor, suppressed the NFAT-luciferase reporter activity induced by ionomycin and phorbol 12-myristate 13-acetate in BMMs. Chromatin immunoprecipitation analysis confirmed that arctigenin inhibited the recruitment of NFATc1 to the promoter region of the NFATc1 target gene. Arctigenin, but not CsA suppressed osteoclast-like cell formation in co-cultures of osteoblastic cells and bone marrow cells, in which the osteoblastic cell-dependent NFATc1 pathway was activated. The forced expression of constitutively active NFATc1 rescued osteoclastogenesis in BMM cultures treated with CsA, but not that treated with arctigenin. Arctigenin also suppressed the pit

Arctigenin inhibits osteoclast differentiation and function by suppressing both calcineurin-dependent and osteoblastic cell-dependent NFATc1 pathways.

Directory of Open Access Journals (Sweden)

Teruhito Yamashita

Full Text Available Arctigenin, a lignan-derived compound, is a constituent of the seeds of Arctium lappa. Arctigenin was previously shown to inhibit osteoclastogenesis; however, this inhibitory mechanism has yet to be elucidated. Here, we showed that arctigenin inhibited the action of nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1, a key transcription factor for osteoclastogenesis. NFATc1 in osteoclast precursors was activated through two distinct pathways: the calcineurin-dependent and osteoblastic cell-dependent pathways. Among the several lignan-derived compounds examined, arctigenin most strongly inhibited receptor activator of nuclear factor κB ligand (RANKL-induced osteoclast-like cell formation in mouse bone marrow macrophage (BMM cultures, in which the calcineurin-dependent NFATc1 pathway was activated. Arctigenin suppressed neither the activation of nuclear factor κB and mitogen-activated protein kinases nor the up-regulation of c-Fos expression in BMMs treated with RANKL. However, arctigenin suppressed RANKL-induced NFATc1 expression. Interestingly, the treatment of osteoclast-like cells with arctigenin converted NFATc1 into a lower molecular weight species, which was translocated into the nucleus even in the absence of RANKL. Nevertheless, arctigenin as well as cyclosporin A (CsA, a calcineurin inhibitor, suppressed the NFAT-luciferase reporter activity induced by ionomycin and phorbol 12-myristate 13-acetate in BMMs. Chromatin immunoprecipitation analysis confirmed that arctigenin inhibited the recruitment of NFATc1 to the promoter region of the NFATc1 target gene. Arctigenin, but not CsA suppressed osteoclast-like cell formation in co-cultures of osteoblastic cells and bone marrow cells, in which the osteoblastic cell-dependent NFATc1 pathway was activated. The forced expression of constitutively active NFATc1 rescued osteoclastogenesis in BMM cultures treated with CsA, but not that treated with arctigenin. Arctigenin also suppressed the

Omentin inhibits TNF-{alpha}-induced expression of adhesion molecules in endothelial cells via ERK/NF-{kappa}B pathway

Energy Technology Data Exchange (ETDEWEB)

Zhong, Xia, E-mail: zhongxia1977@126.com [Department of Emergency, Provincial Hospital Affiliated to Shandong University, Jinan 250021 (China); Li, Xiaonan; Liu, Fuli; Tan, Hui [Department of Emergency, Provincial Hospital Affiliated to Shandong University, Jinan 250021 (China); Shang, Deya, E-mail: wenhuashenghuo1@163.com [Department of Emergency, Provincial Hospital Affiliated to Shandong University, Jinan 250021 (China)

2012-08-24

Highlights: Black-Right-Pointing-Pointer Omentin inhibited TNF-{alpha}-induced adhesion of THP-1 cells to HUVECs. Black-Right-Pointing-Pointer Omentin reduces expression of ICAM-1 and VCAM-1 induced by TNF-{alpha} in HUVECs. Black-Right-Pointing-Pointer Omentin inhibits TNF-{alpha}-induced ERK and NF-{kappa}B activation in HUVECs. Black-Right-Pointing-Pointer Omentin supreeses TNF-{alpha}-induced expression of ICAM-1 and VCAM-1 via ERK/NF-{kappa}B pathway. -- Abstract: In the present study, we investigated whether omentin affected the expression of intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in tumor necrosis factor-{alpha} (TNF-{alpha}) induced human umbilical vein endothelial cells (HUVECs). Our data showed that omentin decreased TNF-{alpha}-induced expression of ICAM-1 and VCAM-1 in HUVECs. In addition, omentin inhibited TNF-{alpha}-induced adhesion of THP-1 cells to HUVECs. Further, we found that omentin inhibited TNF-{alpha}-activated signal pathway of nuclear factor-{kappa}B (NF-{kappa}B) by preventing NF-{kappa}B inhibitory protein (I{kappa}B{alpha}) degradation and NF-{kappa}B/DNA binding activity. Omentin pretreatment significantly inhibited TNF-{alpha}-induced ERK activity and ERK phosphorylation in HUVECs. Pretreatment with PD98059 suppressed TNF-{alpha}-induced NF-{kappa}B activity. Omentin, NF-kB inhibitor (BAY11-7082) and ERK inhibitor (PD98059) reduced the up-regulation of ICAM-1 and VCAM-1 induced by TNF-{alpha}. These results suggest that omentin may inhibit TNF-{alpha}-induced expression of adhesion molecules in endothelial cells via blocking ERK/NF-{kappa}B pathway.

Effective connectivity reveals important roles for both the hyperdirect (fronto-subthalamic) and indirect (fronto-striatal-pallidal) fronto-basal ganglia pathways during response inhibition

NARCIS (Netherlands)

Jahfari, S.; Waldorp, L.; van den Wildenberg, W.P.M.; Scholte, H.S.; Ridderinkhof, K.R.; Forstmann, B.U.

2011-01-01

Fronto-basal ganglia pathways play a crucial role in voluntary action control, including the ability to inhibit motor responses. Response inhibition might be mediated via a fast hyperdirect pathway connecting the right inferior frontal gyrus (rIFG) and the presupplementary motor area (preSMA) with

Intricacies of hedgehog signaling pathways: A perspective in tumorigenesis

International Nuclear Information System (INIS)

Kar, Swayamsiddha; Deb, Moonmoon; Sengupta, Dipta; Shilpi, Arunima; Bhutia, Sujit Kumar; Patra, Samir Kumar

2012-01-01

The hedgehog (HH) signaling pathway is a crucial negotiator of developmental proceedings in the embryo governing a diverse array of processes including cell proliferation, differentiation, and tissue patterning. The overall activity of the pathway is significantly curtailed after embryogenesis as well as in adults, yet it retains many of its functional capacities. However, aberration in HH signaling mediates the initiation, proliferation and continued sustenance of malignancy in different tissues to varying degrees through different mechanisms. In this review, we provide an overview of the role of constitutively active aberrant HH signaling pathway in different types of human cancer and the underlying molecular and genetic mechanisms that drive tumorigenesis in that particular tissue. An insight into the various modes of anomalous HH signaling in different organs will provide a comprehensive knowledge of the pathway in these tissues and open a window for individually tailored, tissue-specific therapeutic interventions. The synergistic cross talking of HH pathway with many other regulatory molecules and developmentally inclined signaling pathways may offer many avenues for pharmacological advances. Understanding the molecular basis of abnormal HH signaling in cancer will provide an opportunity to inhibit the deregulated pathway in many aggressive and therapeutically challenging cancers where promising options are not available.

Intricacies of hedgehog signaling pathways: A perspective in tumorigenesis

Energy Technology Data Exchange (ETDEWEB)

Kar, Swayamsiddha; Deb, Moonmoon; Sengupta, Dipta; Shilpi, Arunima; Bhutia, Sujit Kumar [Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, Odisha 769008 (India); Patra, Samir Kumar, E-mail: samirp@nitrkl.ac.in [Epigenetics and Cancer Research Laboratory, Biochemistry and Molecular Biology Group, Department of Life Science, National Institute of Technology, Rourkela, Odisha 769008 (India)

2012-10-01

The hedgehog (HH) signaling pathway is a crucial negotiator of developmental proceedings in the embryo governing a diverse array of processes including cell proliferation, differentiation, and tissue patterning. The overall activity of the pathway is significantly curtailed after embryogenesis as well as in adults, yet it retains many of its functional capacities. However, aberration in HH signaling mediates the initiation, proliferation and continued sustenance of malignancy in different tissues to varying degrees through different mechanisms. In this review, we provide an overview of the role of constitutively active aberrant HH signaling pathway in different types of human cancer and the underlying molecular and genetic mechanisms that drive tumorigenesis in that particular tissue. An insight into the various modes of anomalous HH signaling in different organs will provide a comprehensive knowledge of the pathway in these tissues and open a window for individually tailored, tissue-specific therapeutic interventions. The synergistic cross talking of HH pathway with many other regulatory molecules and developmentally inclined signaling pathways may offer many avenues for pharmacological advances. Understanding the molecular basis of abnormal HH signaling in cancer will provide an opportunity to inhibit the deregulated pathway in many aggressive and therapeutically challenging cancers where promising options are not available.

Complement-induced histamine release from human basophils. III. Effect of pharmacologic agents.

Science.gov (United States)

Hook, W A; Siraganian, R P

1977-02-01

Human serum activated with zymosan generates a factor (C5a) that releases histamine from autologous basophils. Previously we have presented evidence that this mechanism for C5a-induced release differs from IgE-mediated reactions. The effect of several pharmacologic agents known to alter IgE-mediated release was studied to determine whether they have a similar action on serum-induced release. Deuterium oxide (D2O), which enhances allergic release, inhibited in a concentration-dependent fashion the serum-induced reaction at incubation temperatures of 25 and 32 degrees C. The colchicine-induced inhibition was not reversed by D2O. Cytochalasin B, which gives a variable enhancement of IgE-mediated release, had a marked enhancing effect on the serum-induced reaction in all subjects tested. The following agents known to inhibit the IgE-mediated reaction also inhibited serum-induced release at 25 degrees C: colchicine, dibutyryl cyclic AMP, aminophylline, isoproterenol, cholera toxin, chlorphenesin, diethylcarbamazine, and 2-deoxy-D-glucose. These results suggest that the serum-induced release is modulated by intracellular cyclic AMP, requires energy, and is enhanced by the disruption of microfilaments. The lack of an effect by D2O would suggest that microtubular stabilization is not required. The data can be interpreted to indicate that IgE- and C5a-mediated reactions diverge at a late stage in the histamine release pathway.

Momilactone B Inhibits Ketosis In Vitro by Regulating the ANGPTL3-LPL Pathway and Inhibiting HMGCS2.

Science.gov (United States)

Kang, Dong Young; S P, Nipin; Darvin, Pramod; Joung, Youn Hee; Byun, Hyo Joo; Do, Chang Hee; Park, Kyung Do; Park, Mi Na; Cho, Kwang Hyun; Yang, Young Mok

2017-07-03

Ketogenesis is the production of ketone bodies, which provide energy when the body lacks glucose. Under ketogenic conditions, the body switches from primarily carbohydrate to fat metabolism to maintain energy balance. However, accumulation of high levels of ketone bodies in the blood results in ketosis. Treating ketosis with natural substances is preferable, because they are unlikely to cause side-effects. Momilactone B is an active compound isolated from Korean rice. Based on previous studies, we hypothesized that momilactone B could inhibit ketosis. We constructed an in vitro ketosis model by glucose starvation. We used this model to test the anti-ketosis effects of momilactone B. A primary target for treating ketosis is angiopoietin-like-3 (ANGPTL3), which modulates lipoprotein metabolism by inhibiting lipoprotein lipase (LPL), a multifunctional enzyme that breaks down stored fat to produce triglycerides. We showed that momilactone B could regulate the ANGPTL3-LPL pathway. However, a strong anti-ketosis candidate drug should also inhibit ketogenesis. Ketogenesis can be suppressed by inhibiting the expression of 3-hydroxy-3-methylglutaryl-CoA synthase-2 (HMGCS2), a mitochondrial enzyme that converts acetyl-CoA to ketone bodies. We found that momilactone B suppressed the expression of HMGCS2 through the increased expression of STAT5b. We also elucidated the relationship of STAT5b to ANGPTL3 and LPL expression.

Differential Reponses of Hematopoietic Stem and Progenitor Cells to mTOR Inhibition

Directory of Open Access Journals (Sweden)

Aimin Yang

2015-01-01

Full Text Available Abnormal activation of the mammalian target of rapamycin (mTOR signaling pathway has been observed in a variety of human cancers. Therefore, targeting of the mTOR pathway is an attractive strategy for cancer treatment and several mTOR inhibitors, including AZD8055 (AZD, a novel dual mTORC1/2 inhibitor, are currently in clinical trials. Although bone marrow (BM suppression is one of the primary side effects of anticancer drugs, it is not known if pharmacological inhibition of dual mTORC1/2 affects BM hematopoietic stem and progenitor cells (HSPCs function and plasticity. Here we report that dual inhibition of mTORC1/2 by AZD or its analogue (KU-63794 depletes mouse BM Lin−Sca-1+c-Kit+ cells in cultures via the induction of apoptotic cell death. Subsequent colony-forming unit (CFU assays revealed that inhibition of mTORC1/2 suppresses the clonogenic function of hematopoietic progenitor cells (HPCs in a dose-dependent manner. Surprisingly, we found that dual inhibition of mTORC1/2 markedly inhibits the growth of day-14 cobblestone area-forming cells (CAFCs but enhances the generation of day-35 CAFCs. Given the fact that day-14 and day-35 CAFCs are functional surrogates of HPCs and hematopoietic stem cells (HSCs, respectively, these results suggest that dual inhibition of mTORC1/2 may have distinct effects on HPCs versus HSCs.

Molecular profiling of ALDH1+ colorectal cancer stem cells reveals preferential activation of MAPK, FAK, and oxidative stress prosurvival signalling pathways

DEFF Research Database (Denmark)

Vishnubalaji, Radhakrishnan; Manikandan, Muthurangan; Fahad, Mohamed

2018-01-01

enrichment related to DNA damage, MAPK, FAK, oxidative stress response, and Wnt signalling. ALDH+ cells showed enhanced ROS stress resistance, whereas MAPK/FAK pathway pharmacologic inhibition limited their survival. Conversely, 5-fluorouracil increased the ALDH+ cell fraction among the SW403, HCT116 and SW.......006) and poor DFS (p = 0.05), thus implicating ALDH1A1 and POU5F1 in CRC prognosis. Our data reveal distinct molecular signature of ALDH+ CSCs in CRC and suggest pathways relevant for successful targeted therapies and management of CRC....

Multiple signalling pathways redundantly control glucose transporter GLUT4 gene transcription in skeletal muscle

DEFF Research Database (Denmark)

Murgia, Marta; Elbenhardt Jensen, Thomas; Cusinato, Marzia

2009-01-01

on pharmacological evidence. Here, we have used a more specific genetic approach to establish the relative role of the three pathways in fast and slow muscles. Plasmids coding for protein inhibitors of CaMKII or calcineurin were co-transfected in vivo with a GLUT4 enhancer-reporter construct either in normal mice...... or in mice expressing a dominant negative AMPK mutant. GLUT4 reporter activity was not inhibited in the slow soleus muscle by blocking either CaMKII or calcineurin alone, but was inhibited by blocking both pathways. GLUT4 reporter activity was likewise unchanged in the soleus of dnAMPK mice......, but was significantly reduce by incapacitation of either CaMKII or calcineurin in these mice. On the other hand, in the fast tibialis anterior muscle, calcineurin appears to exert a prominent role in the control of GLUT4 reporter activity, independent of CaMKII and AMPK. The results point to a muscle type...

Aminoflavone, a ligand of the Aryl Hydrocarbon Receptor (AhR), inhibits HIF-1α expression in an AhR-independent fashion

Science.gov (United States)

Terzuoli, Erika; Puppo, Maura; Rapisarda, Annamaria; Uranchimeg, Badarch; Cao, Liang; Burger, Angelika M.; Ziche, Marina; Melillo, Giovanni

2010-01-01

Aminoflavone (AF), the active component of a novel anticancer agent (AFP464) in phase I clinical trials, is a ligand of the aryl hydrocarbon receptor (AhR). AhR dimerizes with HIF-1β/ARNT, which is shared with HIF-1α, a transcription factor critical for the response of cells to oxygen deprivation. To address whether pharmacological activation of the AhR pathway might be a potential mechanism for inhibition of HIF-1, we tested the effects of AF on HIF-1 expression. AF inhibited HIF-1α transcriptional activity and protein accumulation in MCF-7 cells. However, inhibition of HIF-1α by AF was independent from a functional AhR pathway. Indeed, AF inhibited HIF-1α expression in AhR100 cells, in which the AhR pathway is functionally impaired, yet did not induce cytotoxicity, providing evidence that these effects are mediated by distinct signaling pathways. Moreover, AF was inactive in MDA-MB-231 cells, yet inhibited HIF-1α in MDA-MB-231 cells transfected with the SULT1A1 gene. AF inhibited HIF-1α mRNA expression by approximately 50%. Notably, actinomycin-D completely abrogated the ability of AF to down-regulate HIF-1α mRNA, indicating that active transcription was required for the inhibition of HIF-1α expression. Finally, AF inhibited HIF-1α protein accumulation and the expression of HIF-1-target genes in MCF-7 xenografts. These results demonstrate that AF inhibits HIF-1α in an AhR-independent fashion and they unveil additional activities of AF that may be relevant for its further clinical development. PMID:20736373

The Kynurenine Pathway Modulates Neurodegeneration in a Drosophila Model of Huntington’s Disease

Science.gov (United States)

Campesan, Susanna; Green, Edward W.; Breda, Carlo; Sathyasaikumar, Korrapati V.; Muchowski, Paul J.; Schwarcz, Robert; Kyriacou, Charalambos P.; Giorgini, Flaviano

2014-01-01

Summary Neuroactive metabolites of the kynurenine pathway (KP) of tryptophan degradation have been implicated in the pathophysiology of neurodegenerative disorders, including Huntington’s disease (HD) [1]. A central hallmark of HD is neurodegeneration caused by a polyglutamine expansion in the huntingtin (htt) protein [2]. Here we exploit a transgenic Drosophila melanogaster model of HD to interrogate the therapeutic potential of KP manipulation. We observe that genetic and pharmacological inhibition of kynurenine 3-monooxygenase (KMO) increases levels of the neuroprotective metabolite kynurenic acid (KYNA) relative to the neurotoxic metabolite 3-hydroxykynurenine (3-HK) and ameliorates neurodegeneration. We also find that genetic inhibition of tryptophan 2,3-dioxygenase (TDO), the first and rate-limiting step in the pathway, leads to a similar neuroprotective shift toward KYNA synthesis. Importantly, we demonstrate that the feeding of KYNA and 3-HK to HD model flies directly modulates neurodegeneration, underscoring the causative nature of these metabolites. This study provides the first genetic evidence that inhibition of KMO and TDO activity protects against neurodegenerative disease in an animal model, indicating that strategies targeted at two key points within the KP may have therapeutic relevance in HD, and possibly other neurodegenerative disorders. PMID:21636279

Atractylenolide I-mediated Notch pathway inhibition attenuates gastric cancer stem cell traits

Energy Technology Data Exchange (ETDEWEB)

Ma, Li; Mao, Rurong; Shen, Ke; Zheng, Yuanhong; Li, Yueqi [State Key Laboratory of Bioreactor Engineering and Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, #268, 130 Meilong Road, Shanghai 200237 (China); Liu, Jianwen, E-mail: liujian@ecust.edu.cn [State Key Laboratory of Bioreactor Engineering and Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, #268, 130 Meilong Road, Shanghai 200237 (China); Ni, Lei, E-mail: nilei625@yahoo.com [Department of Respiration, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Road II, Shanghai 200025 (China)

2014-07-18

Highlights: • This paper supports the anti-tumor effects of AT-I on gastric cancer in vitro. • AT-I attenuates gastric cancer stem cell traits. • It is the systematic study regarding AT-I suppression of Notch pathway in GC and GCSLCs. - Abstract: Atractylenolide I (AT-I), one of the main naturally occurring compounds of Rhizoma Atractylodis Macrocephalae, has remarkable anti-cancer effects on various cancers. However, its effects on the treatment of gastric cancer remain unclear. Via multiple cellular and molecular approaches, we demonstrated that AT-I could potently inhibit cancer cell proliferation and induce apoptosis through inactivating Notch pathway. AT-I treatment led to the reduction of expressions of Notch1, Jagged1, and its downstream Hes1/ Hey1. Our results showed that AT-I inhibited the self-renewal capacity of gastric stem-like cells (GCSLCs) by suppression of their sphere formation capacity and cell viability. AT-I attenuated gastric cancer stem cell (GCSC) traits partly through inactivating Notch1, leading to reducing the expressions of its downstream target Hes1, Hey1 and CD44 in vitro. Collectively, our results suggest that AT-I might develop as a potential therapeutic drug for the treatment of gastric cancer.

Atractylenolide I-mediated Notch pathway inhibition attenuates gastric cancer stem cell traits

International Nuclear Information System (INIS)

Ma, Li; Mao, Rurong; Shen, Ke; Zheng, Yuanhong; Li, Yueqi; Liu, Jianwen; Ni, Lei

2014-01-01

Highlights: • This paper supports the anti-tumor effects of AT-I on gastric cancer in vitro. • AT-I attenuates gastric cancer stem cell traits. • It is the systematic study regarding AT-I suppression of Notch pathway in GC and GCSLCs. - Abstract: Atractylenolide I (AT-I), one of the main naturally occurring compounds of Rhizoma Atractylodis Macrocephalae, has remarkable anti-cancer effects on various cancers. However, its effects on the treatment of gastric cancer remain unclear. Via multiple cellular and molecular approaches, we demonstrated that AT-I could potently inhibit cancer cell proliferation and induce apoptosis through inactivating Notch pathway. AT-I treatment led to the reduction of expressions of Notch1, Jagged1, and its downstream Hes1/ Hey1. Our results showed that AT-I inhibited the self-renewal capacity of gastric stem-like cells (GCSLCs) by suppression of their sphere formation capacity and cell viability. AT-I attenuated gastric cancer stem cell (GCSC) traits partly through inactivating Notch1, leading to reducing the expressions of its downstream target Hes1, Hey1 and CD44 in vitro. Collectively, our results suggest that AT-I might develop as a potential therapeutic drug for the treatment of gastric cancer

Hyperin protects against LPS-induced acute kidney injury by inhibiting TLR4 and NLRP3 signaling pathways

Science.gov (United States)

Chunzhi, Gong; Zunfeng, Li; Chengwei, Qin; Xiangmei, Bu; Jingui, Yu

2016-01-01

Hyperin is a flavonoid compound derived from Ericaceae, Guttifera, and Celastraceae that has been shown to have various biological effects, such as anti-inflammatory and anti-oxidant effects. However, there is no evidence to show the protective effects of hyperin on lipopolysaccharide (LPS)-induced acute kidney injury (AKI). Therefore, we investigated the protective effects and mechanism of hyperin on LPS-induced AKI in mice. The levels of TNF-α, IL-6, and IL-1β were tested by ELISA. The effects of hyperin on blood urea nitrogen (BUN) and serum creatinine were also detected. In addition, the expression of TLR4, NF-κB, and NLRP3 were detected by western blot analysis. The results showed that hyperin significantly inhibited LPS-induced TNF-α, IL-6, and IL-1β production. The levels of BUN and creatinine were also suppressed by hyperin. Furthermore, LPS-induced TLR4 expression and NF-κB activation were also inhibited by hyperin. In addition, treatment of hyperin dose-dependently inhibited LPS-induced NLRP3 signaling pathway. In conclusion, the results showed that hyperin inhibited LPS-induced inflammatory response by inhibiting TLR4 and NLRP3 signaling pathways. Hyperin has potential application prospects in the treatment of sepsis-induced AKI. PMID:27813491

Apigenin inhibits HGF-promoted invasive growth and metastasis involving blocking PI3K/Akt pathway and β4 integrin function in MDA-MB-231 breast cancer cells

International Nuclear Information System (INIS)

Lee, W.-J.; Chen, W.-K.; Wang, C.-J.; Lin, W.-L.; Tseng, T.-H.

2008-01-01

Hepatocyte growth factor (HGF) and its receptor, Met, known to control invasive growth program have recently been shown to play crucial roles in the survival of breast cancer patients. The diet-derived flavonoids have been reported to possess anti-invasion properties; however, knowledge on the pharmacological and molecular mechanisms in suppressing HGF/Met-mediated tumor invasion and metastasis is poorly understood. In our preliminary study, we use HGF as an invasive inducer to investigate the effect of flavonoids including apigenin, naringenin, genistein and kaempferol on HGF-dependent invasive growth of MDA-MB-231 human breast cancer cells. Results show that apigenin presents the most potent anti-migration and anti-invasion properties by Boyden chamber assay. Furthermore, apigenin represses the HGF-induced cell motility and scattering and inhibits the HGF-promoted cell migration and invasion in a dose-dependent manner. The effect of apigenin on HGF-induced signaling activation involving invasive growth was evaluated by immunoblotting analysis, it shows that apigenin blocks the HGF-induced Akt phosphorylation but not Met, ERK, and JNK phosphorylation. In addition to MDA-MB-231 cells, apigenin exhibits inhibitory effect on HGF-induced Akt phosphorylation in hepatoma SK-Hep1 cells and lung carcinoma A549 cells. By indirect immunofluorescence microscopy assay, apigenin inhibits the HGF-induced clustering of β4 integrin at actin-rich adhesive site and lamellipodia through PI3K-dependent manner. Treatment of apigenin inhibited HGF-stimulated integrin β4 function including cell-matrix adhesion and cell-endothelial cells adhesion in MDA-MB-231 cells. By Akt-siRNA transfection analysis, it confirmed that apigenin inhibited HGF-promoted invasive growth involving blocking PI3K/Akt pathway. Finally, we evaluated the effect of apigenin on HGF-promoted metastasis by lung colonization of tumor cells in nude mice and organ metastasis of tumor cells in chick embryo. By

Proliferation and survival molecules implicated in the inhibition of BRAF pathway in thyroid cancer cells harbouring different genetic mutations

International Nuclear Information System (INIS)

Preto, Ana; Soares, Paula; Sobrinho-Simões, Manuel; Gonçalves, Joana; Rebocho, Ana P; Figueiredo, Joana; Meireles, Ana M; Rocha, Ana S; Vasconcelos, Helena M; Seca, Hugo; Seruca, Raquel

2009-01-01

Thyroid carcinomas show a high prevalence of mutations in the oncogene BRAF which are inversely associated with RAS or RET/PTC oncogenic activation. The possibility of using inhibitors on the BRAF pathway as became an interesting therapeutic approach. In thyroid cancer cells the target molecules, implicated on the cellular effects, mediated by inhibition of BRAF are not well established. In order to fill this lack of knowledge we studied the proliferation and survival pathways and associated molecules induced by BRAF inhibition in thyroid carcinoma cell lines harbouring distinct genetic backgrounds. Suppression of BRAF pathway in thyroid cancer cell lines (8505C, TPC1 and C643) was achieved using RNA interference (RNAi) for BRAF and the kinase inhibitor, sorafenib. Proliferation analysis was performed by BrdU incorporation and apoptosis was accessed by TUNEL assay. Levels of protein expression were analysed by western-blot. Both BRAF RNAi and sorafenib inhibited proliferation in all the cell lines independently of the genetic background, mostly in cells with BRAF V600E mutation. In BRAF V600E mutated cells inhibition of BRAF pathway lead to a decrease in ERK1/2 phosphorylation and cyclin D1 levels and an increase in p27 Kip1 . Specific inhibition of BRAF by RNAi in cells with BRAF V600E mutation had no effect on apoptosis. In the case of sorafenib treatment, cells harbouring BRAF V600E mutation showed increase levels of apoptosis due to a balance of the anti-apoptotic proteins Mcl-1 and Bcl-2. Our results in thyroid cancer cells, namely those harbouring BRAF V600E mutation showed that BRAF signalling pathway provides important proliferation signals. We have shown that in thyroid cancer cells sorafenib induces apoptosis by affecting Mcl-1 and Bcl-2 in BRAF V600E mutated cells which was independent of BRAF. These results suggest that sorafenib may prove useful in the treatment of thyroid carcinomas, particularly those refractory to conventional treatment and

Polydatin inhibits cell proliferation and induces apoptosis in laryngeal cancer and HeLa cells via suppression of the PDGF/AKT signaling pathway.

Science.gov (United States)

Li, Haixia; Shi, Baoyuan; Li, Yanyun; Yin, Fengfang

2017-07-01

Polydatin (PD), a stilbene compound extracted from Polygonum cuspidatum, is suggested to possess anti-cancer activities, including inhibition of cell proliferation, cell cycle arrest, and induction of apoptosis. The platelet-derived growth factor (PDGF)/AKT signaling pathway plays complex roles in tumor suppression. However, the effect of PD on the PDGF/AKT signaling pathway in laryngeal cancer and HeLa cells has not been explored. MTT assay and flow cytometry showed that PD inhibited cell proliferation and induced apoptosis in Hep-2 and AMC-HN-8 cells. Western blot analysis indicated that PD inhibited the expression levels of PDGF-B and phosphorylated AKT (p-AKT) in both cells. Treatment of PDGF-B siRNA or PDGFR inhibitor found that after the PDGF signaling was inactivated, p-AKT expression was significantly decreased in Hep-2 cells. Tumor xenograft experiment in nude mice indicated PD significantly inhibited the growth of Hep-2 cells in vivo. In conclusion, PD inhibited cell proliferation and induced apoptosis in laryngeal cancer and HeLa cells via inactivation of the PDGF/AKT signaling pathway. © 2017 Wiley Periodicals, Inc.

Structural inhibition and reactivation of Escherichia coli septation by elements of the SOS and TER pathways

International Nuclear Information System (INIS)

Dopazo, A.; Tormo, A.; Aldea, M.; Vicente, M.

1987-01-01

The inhibition of cell division caused by induction of the SOS pathway in Escherichia coli structurally blocks septation, as deduced from two sets of results. Potential septation sites active at the time of SOS induction became inactivated, while those initiated during the following doubling time were active. Penicillin resistance increased in wild-type UV light-irradiated cells, a behavior similar to that observed in mutants in which structural blocks were introduced by inactivation of FtsA. Potential septation sites that have been structurally blocked by either the SOS division inhibitor, furazlocillin inhibition of PBP3, or inactivation of a TER pathway component, FtsA3, could be reactivated one doubling time after removal of the inhibitory agent in the presence of an active lon gene product. Reactivation of potential septation sites blocked by the presence of an inactivated FtsA3 was significantly lower when the lon protease was not active, suggesting that Lon plays a role in the removal of inactivated TER pathway products from the blocked potential septation sites

Metformin inhibits inflammatory response via AMPK–PTEN pathway in vascular smooth muscle cells

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Kim, Sun Ae; Choi, Hyoung Chul

2012-01-01

Highlights: ► PTEN was induced by metformin and inhibited by compound C and AMPK siRNA. ► Metformin suppressed TNF-α-induced COX-2 and iNOS mRNA expression. ► Compound C and bpv (pic) increased iNOS and COX-2 protein expression. ► NF-κB activation was restored by inhibiting AMPK and PTEN. ► AMPK and PTEN regulated TNF-α-induced ROS production in VSMCs. -- Abstract: Atherosclerosis is a chronic inflammation of the coronary arteries. Vascular smooth muscle cells (VSMCs) stimulated by cytokines and chemokines accelerate the inflammatory response and migrate to the injured endothelium during the progression of atherosclerosis. Activation of AMP activated protein kinase (AMPK), a key sensor maintaining metabolic homeostasis, suppresses the inflammatory response. However, how AMPK regulates the inflammatory response is poorly understood. To identify the mechanism of this response, we focused on phosphatase and tensin homolog (PTEN), which is a negative regulator of inflammation. We investigated that activation of AMPK-induced PTEN expression and suppression of the inflammatory response through the AMPK–PTEN pathway in VSMCs. We treated with the well-known AMPK activator metformin to induce PTEN expression. PTEN was induced by metformin (2 mM) and inhibited by compound C (10 μM) and AMPK siRNA. Tumor necrosis factor-alpha (TNF-α) was used to induce inflammation. The inflammatory response was confirmed by cyclooxygenase (COX)-2, inducible nitric oxide synthase (iNOS) expression, and activation of nuclear factor (NF)-κB. Metformin suppressed COX-2 and iNOS mRNA and protein expression dose dependently. Treatment with compound C and bpv (pic) in the presence of metformin, iNOS and COX-2 protein expression increased. NF-κB activation decreased in response to metformin and was restored by inhibiting AMPK and PTEN. Inhibiting AMPK and PTEN restored ROS levels stimulated with TNF-α. Taken together, PTEN could be a possible downstream regulator of AMPK, and the

Inhibition of p70S6K2 down-regulates Hedgehog/GLI pathway in non-small cell lung cancer cell lines

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Kotani Hidehito

2009-07-01

Full Text Available Abstract Background The Hedgehog (HH pathway promotes tumorigenesis in a diversity of cancers. Activation of the HH signaling pathway is caused by overexpression of HH ligands or mutations in the components of the HH/GLI1 cascade, which lead to increased transactivation of GLI transcription factors. Although negative kinase regulators that antagonize the activity of GLI transcription factors have been reported, including GSK3β, PKA and CK1s, little is known regarding positive kinase regulators that are suitable for use on cancer therapeutic targets. The present study attempted to identify kinases whose silencing inhibits HH/GLI signalling in non-small cell lung cancer (NSCLC. Results To find positive kinase regulators in the HH pathway, kinome-wide siRNA screening was performed in a NSCLC cell line, A549, harboring the GLI regulatory reporter gene. This showed that p70S6K2-silencing remarkably reduced GLI reporter gene activity. The decrease in the activity of the HH pathway caused by p70S6K2-inhibition was accompanied by significant reduction in cell viability. We next investigated the mechanism for p70S6K2-mediated inhibition of GLI1 transcription by hypothesizing that GSK3β, a negative regulator of the HH pathway, is activated upon p70S6K2-silencing. We found that phosphorylated-GSK3β (Ser9 was reduced by p70S6K2-silencing, causing a decreased level of GLI1 protein. Finally, to further confirm the involvement of p70S6K2 in GLI1 signaling, down-regulation in GLI-mediated transcription by PI3KCA-inhibition was confirmed, establishing the pivotal role of the PI3K/p70S6K2 pathway in GLI1 cascade regulation. Conclusion We report herein that inhibition of p70S6K2, known as a downstream effector of the PI3K pathway, remarkably decreases GLI-mediated transactivation in NSCLC by reducing phosphorylated-GSK3β followed by GLI1 degradation. These results infer that p70S6K2 is a potential therapeutic target for NSCLC with hyperactivated HH/GLI pathway.

Pharmacologic pre- and postconditioning for stroke: Basic mechanisms and translational opportunity

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Elga Esposito

2015-01-01

Full Text Available Beyond reperfusion therapies, there are still no widely effective therapies for ischemic stroke. Although much progress has been made to define the molecular pathways involved, targeted neuroprotective strategies have often failed in clinical trials. An emerging hypothesis suggests that focusing on single targets and mechanisms may not work since ischemic stroke triggers multiple pathways in multiple cell types. In this review, we briefly survey and assess the opportunities that may be afforded by pre- and postconditioning therapies, with particular attention to pharmacologic pre- and postconditioning. Pharmacologic conditioning may be defined as the use of chemical agents either before or shortly after stroke onset to trigger mechanisms of endogenous tolerance that are thought to involve evolutionarily conserved signals that offer broad protection against ischemia. Importantly, many of the pharmacologic agents may also have been previously used in humans, thus providing hope for translating basic mechanisms into clinical applications.

Transcutaneous electrical nerve stimulation attenuates CFA-induced hyperalgesia and inhibits spinal ERK1/2-COX-2 pathway activation in rats.

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Fang, Jun-Fan; Liang, Yi; Du, Jun-Ying; Fang, Jian-Qiao

2013-06-15

Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacologic treatment for pain relief. In previous animal studies, TENS effectively alleviated Complete Freund's Adjuvant (CFA)- or carrageenan-induced inflammatory pain. Although TENS is known to produce analgesia via opioid activation in the brain and at the spinal level, few reports have investigated the signal transduction pathways mediated by TENS. Prior studies have verified the importance of the activation of extracellular signal-regulated kinase (ERK) signal transduction pathway in the spinal cord dorsal horn (SCDH) in acute and persistent inflammatory pains. Here, by using CFA rat model, we tested the efficacy of TENS on inhibiting the expressions of p-ERK1/2 and of its downstream cyclooxygenase-2 (COX-2) and the level of prostaglandin E2 (PGE2) at spinal level. Rats were randomly divided into control, model and TENS groups, and injected subcutaneously with 100 μl CFA or saline in the plantar surface of right hind paw. Rats in the TENS group were treated with TENS (constant aquare wave, 2 Hz and 100 Hz alternating frequencies, intensities ranging from 1 to 2 mA, lasting for 30 min each time) at 5 h and 24 h after injection. Paw withdrawal thresholds (PWTs) were measured with dynamic plantar aesthesiometer at 3d before modeling and 5 h, 6 h, and 25 h after CFA injection. The ipsilateral sides of the lumbar spinal cord dosral horns were harvested for detecting the expressions of p-ERK1/2 and COX-2 by western blot analysis and qPCR, and PGE2 by ELISA. CFA-induced periphery inflammation decreased PWTs and increased paw volume of rats. TENS treatment significantly alleviated mechanical hyperalgesia caused by CFA. However, no anti-inflammatory effect of TENS was observed. Expression of p-ERK1/2 protein and COX-2 mRNA was significantly up-regualted at 5 h and 6 h after CFA injection, while COX-2 and PGE2 protein level only increased at 6 h after modeling. Furthermore, the high expression of p-ERK1

Trials of Pharmacological Interventions for Tourette Syndrome: A Systematic Review

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Karen Waldon

2013-01-01

Full Text Available Introduction: Gilles de la Tourette Syndrome (GTS is a childhood-onset hyperkinetic movement disorder defined by the chronic presence of multiple motor tics and at least one vocal tic and often complicated by co-morbid behavioural problems. The pharmacological treatment of GTS focuses on the modulation of monoaminergic pathways within the cortico-striato-thalamo-cortical circuitry. This paper aims to evaluate the efficacy and safety profiles of pharmacological agents used in the treatment of tics in patients with GTS, in order to provide clinicians with an evidence-based rationale for the pharmacological treatment in GTS.

Kaempferol Inhibits the Invasion and Migration of Renal Cancer Cells through the Downregulation of AKT and FAK Pathways.

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Hung, Tung-Wei; Chen, Pei-Ni; Wu, Hsu-Chen; Wu, Sheng-Wen; Tsai, Pao-Yu; Hsieh, Yih-Shou; Chang, Horng-Rong

2017-01-01

Kaempferol, which is isolated from several natural plants, is a polyphenol belonging to the subgroup of flavonoids. Kaempferol exhibits various pharmacological activities, including anti-inflammatory, antioxidant, antimicrobial, and anticancer activities. In this study, kaempferol can significantly inhibit the invasion and migration of 786-O renal cell carcinoma (RCC) without cytotoxicity. We examined the potential mechanisms underlying its anti-invasive activities on 786-O RCC cells. Western blot was performed, and the results showed that kaempferol attenuates the manifestation of metalloproteinase-2 (MMP-2) protein and activity. The inhibitive effect of kaempferol on MMP-2 may be attributed to the downregulation of phosphorylation of Akt and focal adhesion kinase (FAK). By examining the SCID mice model, we found that kaempferol can safely inhibit the metastasis of the 786-O RCC cells into the lungs by about 87.4% as compared to vehicle treated control animals. In addition, the lung tumor masses of mice pretreated with 2-10 mg/kg kaempferol were reduced about twofold to fourfold. These data suggested that kaempferol can play a promising role in tumor prevention and cancer metastasis inhibition.

Inhibition of estrogen-responsive gene activation by the retinoid X receptor beta: evidence for multiple inhibitory pathways.

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Segars, J H; Marks, M S; Hirschfeld, S; Driggers, P H; Martinez, E; Grippo, J F; Brown, M; Wahli, W; Ozato, K

1993-04-01

The retinoid X receptor beta (RXR beta; H-2RIIBP) forms heterodimers with various nuclear hormone receptors and binds multiple hormone response elements, including the estrogen response element (ERE). In this report, we show that endogenous RXR beta contributes to ERE binding activity in nuclear extracts of the human breast cancer cell line MCF-7. To define a possible regulatory role of RXR beta regarding estrogen-responsive transcription in breast cancer cells, RXR beta and a reporter gene driven by the vitellogenin A2 ERE were transfected into estrogen-treated MCF-7 cells. RXR beta inhibited ERE-driven reporter activity in a dose-dependent and element-specific fashion. This inhibition occurred in the absence of the RXR ligand 9-cis retinoic acid. The RXR beta-induced inhibition was specific for estrogen receptor (ER)-mediated ERE activation because inhibition was observed in ER-negative MDA-MB-231 cells only following transfection of the estrogen-activated ER. No inhibition of the basal reporter activity was observed. The inhibition was not caused by simple competition of RXR beta with the ER for ERE binding, since deletion mutants retaining DNA binding activity but lacking the N-terminal or C-terminal domain failed to inhibit reporter activity. In addition, cross-linking studies indicated the presence of an auxiliary nuclear factor present in MCF-7 cells that contributed to RXR beta binding of the ERE. Studies using known heterodimerization partners of RXR beta confirmed that RXR beta/triiodothyronine receptor alpha heterodimers avidly bind the ERE but revealed the existence of another triiodothyronine-independent pathway of ERE inhibition. These results indicate that estrogen-responsive genes may be negatively regulated by RXR beta through two distinct pathways.

Caloric restriction protects against electrical kindling of the amygdala by inhibiting the mTOR signaling pathway

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Bryan Victor Phillips-Farfan

2015-03-01

Full Text Available Caloric restriction (CR has been shown to possess antiepileptic properties; however its mechanism of action is poorly understood. CR might inhibit the activity of the mammalian or mechanistic target of rapamycin (mTOR signaling cascade, which seems to participate crucially in the generation of epilepsy. Thus, we investigated the effect of CR on the mTOR pathway and whether CR modified epilepsy generation due to electrical amygdala kindling. The former was studied by analyzing the phosphorylation of adenosine monophosphate-activated protein kinase, protein kinase B and the ribosomal protein S6. The mTOR cascade is regulated by energy and by insulin levels, both of which may be changed by CR; thus we investigated if CR altered the levels of energy substrates in the blood or the level of insulin in plasma. Finally, we studied if CR modified the expression of genes that encode proteins participating in the mTOR pathway. CR increased the after-discharge threshold and tended to reduce the after-discharge duration, indicating an anti-convulsive action. CR diminished the phosphorylation of protein kinase B and ribosomal protein S6, suggesting an inhibition of the mTOR cascade. However, CR did not change glucose, β-hydroxybutyrate or insulin levels; thus the effects of CR were independent from them. Interestingly, CR also did not modify the expression of any investigated gene. The results suggest that the anti-epileptic effect of CR may be partly due to inhibition of the mTOR pathway.

Maturation of GABAergic inhibition promotes strengthening of temporally coherent inputs among convergent pathways.

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Sandra J Kuhlman

2010-06-01

Full Text Available Spike-timing-dependent plasticity (STDP, a form of Hebbian plasticity, is inherently stabilizing. Whether and how GABAergic inhibition influences STDP is not well understood. Using a model neuron driven by converging inputs modifiable by STDP, we determined that a sufficient level of inhibition was critical to ensure that temporal coherence (correlation among presynaptic spike times of synaptic inputs, rather than initial strength or number of inputs within a pathway, controlled postsynaptic spike timing. Inhibition exerted this effect by preferentially reducing synaptic efficacy, the ability of inputs to evoke postsynaptic action potentials, of the less coherent inputs. In visual cortical slices, inhibition potently reduced synaptic efficacy at ages during but not before the critical period of ocular dominance (OD plasticity. Whole-cell recordings revealed that the amplitude of unitary IPSCs from parvalbumin positive (Pv+ interneurons to pyramidal neurons increased during the critical period, while the synaptic decay time-constant decreased. In addition, intrinsic properties of Pv+ interneurons matured, resulting in an increase in instantaneous firing rate. Our results suggest that maturation of inhibition in visual cortex ensures that the temporally coherent inputs (e.g. those from the open eye during monocular deprivation control postsynaptic spike times of binocular neurons, a prerequisite for Hebbian mechanisms to induce OD plasticity.

Andrographolide inhibits hypoxia-inducible factor-1 through phosphatidylinositol 3-kinase/AKT pathway and suppresses breast cancer growth

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Li J

2015-02-01

Full Text Available Jie Li,1 Chao Zhang,1 Hongchuan Jiang,1 Jiao Cheng21Department of General Surgery, 2Department of Gynaecology and Obstetrics, Beijing Chao-Yang Hospital, Beijing, People’s Republic of ChinaAbstract: Hypoxia-inducible factor-1 (HIF-1 is a master regulator of the transcriptional response to hypoxia. HIF-1α is one of the most compelling anticancer targets. Andrographolide (Andro was newly identified to inhibit HIF-1 in T47D cells (a half maximal effective concentration [EC50] of 1.03×10-7 mol/L, by a dual-luciferase reporter assay. It suppressed HIF-1α protein and gene accumulation, which was dependent on the inhibition of upstream phosphatidylinositol 3-kinase (PI3K/AKT pathway. It also abrogated the expression of HIF-1 target vascular endothelial growth factor (VEGF gene and protein. Further, Andro inhibited T47D and MDA-MB-231 cell proliferation and colony formation. In addition, it exhibited significant in vivo efficacy and antitumor potential against the MDA-MB-231 xenograft in nude mice. In conclusion, these results highlighted the potential effects of Andro, which inhibits HIF-1, and hence may be developed as an antitumor agent for breast cancer therapy in future.Keywords: Andrographolide (Andro, HIF-1α, inhibit, breast cancer, hypoxia, PI3k/AKT/mTOR pathway

Mefloquine effectively targets gastric cancer cells through phosphatase-dependent inhibition of PI3K/Akt/mTOR signaling pathway

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Liu, Yanwei [Department of General Surgery, Shiyan Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei Province (China); Chen, Sen [Department of Academic Affairs, Hubei University of Medicine, Shiyan, Hubei Province (China); Xue, Rui [Department of Anesthesiology, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei Province (China); Zhao, Juan [Department of Oncology, Xiangyang Central Hospital, Shiyan, Hubei Province (China); Di, Maojun, E-mail: maoojun_di@163.com [Department of General Surgery, Shiyan Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei Province (China)

2016-02-05

Deregulation of PI3K/Akt/mTOR pathway has been recently identified to play a crucial role in the progress of human gastric cancer. In this study, we show that mefloquine, a FDA-approved anti-malarial drug, effectively targets human gastric cancer cells. Mefloquine potently inhibits proliferation and induces apoptosis of a panel of human gastric cancer cell lines, with EC{sub 50} ∼0.5–0.7 μM. In two independent gastric cancer xenograft mouse models, mefloquine significantly inhibits growth of both tumors. The combination of mefloquine with paclitaxel enhances the activity of either drug alone in in vitro and in vivo. In addition, mefloquine potently decreased phosphorylation of PI3K, Akt, mTOR and rS6. Overexpression of constitutively active Akt significantly restored mefloquine-mediated inhibition of mTOR phosphorylation and growth, and induction of apoptosis, suggesting that mefloquine acts on gastric cancer cells via suppressing PI3K/Akt/mTOR pathway. We further show that mefloquine-mediated inhibition of Akt/mTOR singaling is phosphatase-dependent as pretreatment with calyculin A does-dependently reversed mefloquine-mediated inhibition of Akt/mTOR phosphorylation. Since mefloquine is already available for clinic use, these results suggest that it is a useful addition to the treatment armamentarium for gastric cancer. - Highlights: • Mefloquine targets a panel of gastric cancer cell lines in vitro and in vivo. • Combination of mefloquine and paclitaxel is synergistic. • Mefloquine acts on gastric cancer via inhibition of PI3K/Akt/mTOR pathway. • Mefloquine can be repurposed for gastric cancer treatment.

Sodium orthovanadate associated with pharmacological doses of ascorbate causes an increased generation of ROS in tumor cells that inhibits proliferation and triggers apoptosis

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Günther, T-hat nia Mara Fischer; Kviecinski, Maicon Roberto; Baron, Carla Cristine; Felipe, Karina Bettega; Farias, Mirelle Sifroni; Ourique da Silva, Fabiana; Bücker, Nádia Cristina Falcão [Departamento de Bioquímica, Universidade Federal de Santa Catarina, Florianópolis (Brazil); Pich, Claus Tröger [Campus de Araranguá, Universidade Federal de Santa Catarina, Araranguá (Brazil); Ferreira, Eduardo Antonio [Universidade de Brasília, Faculdade de Ceilândia, DF (Brazil); Filho, Danilo Wilhelm [Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis (Brazil); Verrax, Julien; Calderon, Pedro Buc [Toxicology and Cancer Biology Research Group, Louvain Drug Research Institute, Université Catholique de Louvain, Brussels (Belgium); Pedrosa, Rozangela Curi, E-mail: rozangelapedrosa@gmail.com [Departamento de Bioquímica, Universidade Federal de Santa Catarina, Florianópolis (Brazil)

2013-01-18

Graphical abstract: -- Abstract: Pharmacological doses of ascorbate were evaluated for its ability to potentiate the toxicity of sodium orthovanadate (Na{sub 3}VO{sub 4}) in tumor cells. Cytotoxicity, inhibition of cell proliferation, generation of ROS and DNA fragmentation were assessed in T24 cells. Na{sub 3}VO{sub 4} was cytotoxic against T24 cells (EC{sub 50} = 5.8 μM at 24 h), but in the presence of ascorbate (100 μM) the EC{sub 50} fell to 3.3 μM. Na{sub 3}VO{sub 4} plus ascorbate caused a strong inhibition of cell proliferation (up to 20%) and increased the generation of ROS (4-fold). Na{sub 3}VO{sub 4} did not directly cleave plasmid DNA, at this aspect no synergism was found occurring between Na{sub 3}VO{sub 4} and ascorbate once the resulting action of the combination was no greater than that of both substances administered separately. Cells from Ehrlich ascites carcinoma-bearing mice were used to determine the activity of antioxidant enzymes, the extent of the oxidative damage and the type of cell death. Na{sub 3}VO{sub 4} alone, or combined with ascorbate, increased catalase activity, but only Na{sub 3}VO{sub 4} plus ascorbate increased superoxide dismutase activity (up to 4-fold). Oxidative damage on proteins and lipids was higher due to the treatment done with Na{sub 3}VO{sub 4} plus ascorbate (2–3-fold). Ascorbate potentiated apoptosis in tumor cells from mice treated with Na{sub 3}VO{sub 4}. The results indicate that pharmacological doses of ascorbate enhance the generation of ROS induced by Na{sub 3}VO{sub 4} in tumor cells causing inhibition of proliferation and apoptosis. Apoptosis induced by orthovanadate and ascorbate is closer related to inhibition on Bcl-xL and activation of Bax. Our data apparently rule out a mechanism of cell demise p53-dependent or related to Cdk2 impairment.

Valsartan Reduced Atrial Fibrillation Susceptibility by Inhibiting Atrial Parasympathetic Remodeling through MAPKs/Neurturin Pathway

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Lei Liu

2015-07-01

Full Text Available Background/Aims: Angiotensin II receptor blockers (ARBs have been proved to be effective in preventing atrial structural and electrical remodelinq in atrial fibrillation (AF. Previous studies have shown that parasympathetic remodeling plays an important role in AF. However, the effects of ARBs on atrial parasympathetic remodeling in AF and the underlying mechanisms are still unknown. Methods: Canines were divided into sham-operated, pacing and valsartan + pacing groups. Rats and HL-1 cardiomyocytes were divided into control, angiotensin II (Ang II and Ang II + valsartan groups, respectively. Atrial parasympathetic remodeling was quantified by immunocytochemical staining with anti-choline acetyltransferase (ChAT antibody. Western blot was used to analysis the protein expression of neurturin. Results: Both inducibility and duration were increased in chronic atrial rapid-pacing canine model, which was significantly inhibited by the treatment with valsartan. The density of ChAT-positive nerves and the protein level of neurturin in the atria of pacing canines were both increased than those in sham-operated canines. Ang II treatment not only induced atrial parasympathetic remodeling in rats, but also up-regulated the protein expression of neurturin. Valsartan significantly prevented atrial parasympathetic remodeling, and suppressed the protein expression of neurturin. Meanwhile, valsartan inhibited Ang II -induced up-regulation of neurturin and MAPKs in cultured cardiac myocytes. Inhibition of MAPKs dramatically attenuated neurturin up-regulation induced by Ang II. Conclusion: Parasympathetic remodeling was present in animals subjected to rapid pacing or Ang II infusion, which was mediated by MAPKs/neurturin pathway. Valsartan is able to prevent atrial parasympathetic remodeling and the occurrence of AF via inhibiting MAPKs/neurturin pathway.

Valsartan Reduced Atrial Fibrillation Susceptibility by Inhibiting Atrial Parasympathetic Remodeling through MAPKs/Neurturin Pathway.

Science.gov (United States)

Liu, Lei; Geng, Jianqiang; Zhao, Hongwei; Yun, Fengxiang; Wang, Xiaoyu; Yan, Sen; Ding, Xue; Li, Wenpeng; Wang, Dingyu; Li, Jianqiang; Pan, Zhenwei; Gong, Yongtai; Tan, Xiangyang; Li, Yue

2015-01-01

Angiotensin II receptor blockers (ARBs) have been proved to be effective in preventing atrial structural and electrical remodelinq in atrial fibrillation (AF). Previous studies have shown that parasympathetic remodeling plays an important role in AF. However, the effects of ARBs on atrial parasympathetic remodeling in AF and the underlying mechanisms are still unknown. Canines were divided into sham-operated, pacing and valsartan + pacing groups. Rats and HL-1 cardiomyocytes were divided into control, angiotensin II (Ang II) and Ang II + valsartan groups, respectively. Atrial parasympathetic remodeling was quantified by immunocytochemical staining with anti-choline acetyltransferase (ChAT) antibody. Western blot was used to analysis the protein expression of neurturin. Both inducibility and duration were increased in chronic atrial rapid-pacing canine model, which was significantly inhibited by the treatment with valsartan. The density of ChAT-positive nerves and the protein level of neurturin in the atria of pacing canines were both increased than those in sham-operated canines. Ang II treatment not only induced atrial parasympathetic remodeling in rats, but also up-regulated the protein expression of neurturin. Valsartan significantly prevented atrial parasympathetic remodeling, and suppressed the protein expression of neurturin. Meanwhile, valsartan inhibited Ang II -induced up-regulation of neurturin and MAPKs in cultured cardiac myocytes. Inhibition of MAPKs dramatically attenuated neurturin up-regulation induced by Ang II. Parasympathetic remodeling was present in animals subjected to rapid pacing or Ang II infusion, which was mediated by MAPKs/neurturin pathway. Valsartan is able to prevent atrial parasympathetic remodeling and the occurrence of AF via inhibiting MAPKs/neurturin pathway. © 2015 S. Karger AG, Basel.

Pharmacological inhibition of arachidonate 15-lipoxygenase (ALOX15) protects human spermatozoa against oxidative stress.

Science.gov (United States)

Walters, Jessica L H; De Iuliis, Geoffry N; Dun, Matthew D; Aitken, Robert John; McLaughlin, Eileen A; Nixon, Brett; Bromfield, Elizabeth G

2018-03-13

One of the leading causes of male infertility is defective sperm function, a pathology that commonly arises from oxidative stress in the germline. Lipid peroxidation events in the sperm plasma membrane result in the generation of cytotoxic aldehydes such as 4-hydroxynonenal (4HNE), which accentuate the production of reactive oxygen species (ROS) and cause cellular damage. One of the key enzymes involved in the metabolism of polyunsaturated fatty acids to 4HNE in somatic cells is arachidonate 15-lipoxygenase (ALOX15). Although ALOX15 has yet to be characterized in human spermatozoa, our previous studies have revealed a strong link between ALOX15 activity and the levels of oxidative stress and 4HNE in mouse germ cell models. In view of these data, we sought to assess the function of ALOX15 in mature human spermatozoa and determine whether the pharmacological inhibition of this enzyme could influence the level of oxidative stress experienced by these cells. By driving oxidative stress in vitro with exogenous H2O2, our data reveal that 6,11-dihydro[1]benzothiopyrano[4,3-b]indole (PD146176; a selective ALOX15 inhibitor), was able to significantly reduce several deleterious, oxidative insults in spermatozoa. Indeed, PD146176 attenuated the production of ROS, as well as membrane lipid peroxidation and 4HNE production in human spermatozoa. Accordingly, ALOX15 inhibition also protected the functional competence of these cells to acrosome react and bind homologous human zonae pellucidae. Together, these results implicate ALOX15 in the propagation of an oxidative stress cascade within human spermatozoa and offer insight into potential therapeutic avenues to address male fertility that arises from oxidative stress.

Chemoprevention utility of silibinin and Cdk4 pathway inhibition in Apc−/+ mice

International Nuclear Information System (INIS)

Karim, Baktiar O; Rhee, Ki-Jong; Liu, Guosheng; Zheng, Dongfeng; Huso, David L

2013-01-01

Colorectal cancer (CRC) is the second leading cause of death from cancer in the United States. Colorectal cancers have a prolonged latency following initiation that may span decades providing ample time for implementing a chemoprevention strategy that could block or reverse the progression to CRC. Cdk4 pathway alterations have been linked to a number of cancers including CRC. In these experiments we focused on the Cdk4 pathway and its role in intestinal tumorigenesis as a possible target in chemoprevention strategies. We evaluated the effect of Cdk4 blockade on the prevention of intestinal tumor formation by crossing Cdk4 −/− mice to Apc −/+ mice. In addition, we tested the effect of the dietary compound silibinin on the Cdk4 pathway in Apc −/+ mice and HT-29 colon cancer cells in culture. Cdk4 −/− mice backcrossed to Apc −/+ mice reduced intestinal adenoma formation compared to Apc −/+ controls. Silibinin effectively targeted the Cdk4 pathway causing hypophosphorylation of the retinoblastoma protein, inhibited cell growth, and induced apoptosis. As a result silibinin blocked the development of intestinal adenomas by 52% in this genetic model (Apc −/+ mice) of early events in colorectal cancer formation. No toxic abnormalities were detected in mice which received silibinin. Modification of the Cdk4 pathway using a natural plant-derived compound such as silibinin may be a useful chemopreventive strategy for colorectal carcinomas

4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to inhibit hepatocellular carcinoma cells

International Nuclear Information System (INIS)

Fu, Meili; Wan, Fuqiang; Li, Zhengling; Zhang, Fenghua

2016-01-01

The aim of the present study is to investigate the potential anti-hepatocellular carcinoma (HCC) cell activity by 4SC-202, a novel class I HDAC inhibitor (HDACi). The associated signaling mechanisms were also analyzed. We showed that 4SC-202 treatment induced potent cytotoxic and proliferation–inhibitory activities against established HCC cell lines (HepG2, HepB3, SMMC-7721) and patient-derived primary HCC cells. Further, adding 4SC-202 in HCC cells activated mitochondrial apoptosis pathway, which was evidenced by mitochondrial permeability transition pore (mPTP) opening, cytochrome C cytosol release and caspase-3/-9 activation. Inhibition of this apoptosis pathway, by caspase-3/-9 inhibitors, mPTP blockers, or by shRNA-mediated knockdown of cyclophilin-D (Cyp-D, a key component of mPTP), significantly attenuated 4SC-202-induced HCC cell death and apoptosis. Reversely, over-expression of Cyp-D enhanced 4SC-202's sensitivity in HCC cells. Further studies showed that 4SC-202 induced apoptosis signal-regulating kinase 1 (ASK1) activation, causing it translocation to mitochondria and physical association with Cyp-D. This mitochondrial ASK1-Cyp-D complexation appeared required for mediating 4SC-202-induced apoptosis activation. ASK1 stable knockdown by targeted-shRNAs largely inhibited 4SC-202-induced mPTP opening, cytochrome C release, and following HCC cell apoptotic death. Together, we suggest that 4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to potently inhibit human HCC cells. - Highlights: • 4SC-202 exerts potent anti-proliferative and cytotoxic activity against established/primary HCC cells. • SC-202-induced anti-HCC cell activity relies on caspase-dependent apoptosis activation. • 4SC-202 activates Cyp-D-dependent mitochondrial apoptosis pathway in HCC cells. • 4SC-202 activates ASK1 in HCC cells, causing it translocation to mitochondria. • Mitochondrial ASK1-Cyp-D complexation mediates 4SC-202's activity in HCC cells.

4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to inhibit hepatocellular carcinoma cells

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Fu, Meili, E-mail: fumeilidrlinyi@tom.com [Department of Infectious Disease, Linyi People' s Hospital, Linyi 276000 (China); Wan, Fuqiang [Department of Head and Neck Surgery, Linyi Tumor Hospital, Linyi 276000 (China); Li, Zhengling [Department of Nursing, Tengzhou Central People' s Hospital, Tengzhou 277500 (China); Zhang, Fenghua [Department of Operating Room, Linyi People' s Hospital, Linyi 276000 (China)

2016-03-04

The aim of the present study is to investigate the potential anti-hepatocellular carcinoma (HCC) cell activity by 4SC-202, a novel class I HDAC inhibitor (HDACi). The associated signaling mechanisms were also analyzed. We showed that 4SC-202 treatment induced potent cytotoxic and proliferation–inhibitory activities against established HCC cell lines (HepG2, HepB3, SMMC-7721) and patient-derived primary HCC cells. Further, adding 4SC-202 in HCC cells activated mitochondrial apoptosis pathway, which was evidenced by mitochondrial permeability transition pore (mPTP) opening, cytochrome C cytosol release and caspase-3/-9 activation. Inhibition of this apoptosis pathway, by caspase-3/-9 inhibitors, mPTP blockers, or by shRNA-mediated knockdown of cyclophilin-D (Cyp-D, a key component of mPTP), significantly attenuated 4SC-202-induced HCC cell death and apoptosis. Reversely, over-expression of Cyp-D enhanced 4SC-202's sensitivity in HCC cells. Further studies showed that 4SC-202 induced apoptosis signal-regulating kinase 1 (ASK1) activation, causing it translocation to mitochondria and physical association with Cyp-D. This mitochondrial ASK1-Cyp-D complexation appeared required for mediating 4SC-202-induced apoptosis activation. ASK1 stable knockdown by targeted-shRNAs largely inhibited 4SC-202-induced mPTP opening, cytochrome C release, and following HCC cell apoptotic death. Together, we suggest that 4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to potently inhibit human HCC cells. - Highlights: • 4SC-202 exerts potent anti-proliferative and cytotoxic activity against established/primary HCC cells. • SC-202-induced anti-HCC cell activity relies on caspase-dependent apoptosis activation. • 4SC-202 activates Cyp-D-dependent mitochondrial apoptosis pathway in HCC cells. • 4SC-202 activates ASK1 in HCC cells, causing it translocation to mitochondria. • Mitochondrial ASK1-Cyp-D complexation mediates 4SC-202's activity in HCC cells.

Porcine Circovirus-Like Virus P1 Inhibits Wnt Signaling Pathway in Vivo and in Vitro.

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Zhu, Xuejiao; Wen, Libin; Sheng, Shaoyang; Wang, Wei; Xiao, Qi; Qu, Meng; Hu, Yiyi; Liu, Chuanmin; He, Kongwang

2018-01-01

Porcine circovirus-like virus P1 is an important pathogen of the current pig industry, the infection mechanism is not entirely clear. Wnt signaling pathway plays an important role in the growth of young animals and infection of some viruses. This study was designed to demonstrate the effects of P1 infection on the Wnt signaling pathway. In vivo experiments, we demonstrated the down-regulatory effects of P1 infection in piglets and mice on the downstream components expression levels of Wnt signaling pathway, and the effects of Wnt signaling pathway activation on the pathogenesis of P1. In vitro studies, we found P1 infection down-regulated protein level of β-catenin and mRNA level of mmp2, prevented the β-catenin from entering into nucleus, abolished the TCF/LEF promoter activity, proved that P1 could inhibit the activation of Wnt signaling pathway in vitro . Finally, we found that VP1 of P1 virus also had the inhibitory effects on Wnt signaling pathway in vitro , elucidated the mechanism of P1's inhibitory effects on the Wnt signaling pathway and offered the possibility that the suppression of Wnt signaling pathway was involved in the post-weaning multisystemic wasting syndrome (PMWS), laying a foundation for elucidating the pathogenesis of P1.

Kirenol inhibits adipogenesis through activation of the Wnt/β-catenin signaling pathway in 3T3-L1 adipocytes

Energy Technology Data Exchange (ETDEWEB)

Kim, Mi-Bo [Department of Biomaterials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Song, Youngwoo; Kim, Changhee [Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Hwang, Jae-Kwan, E-mail: jkhwang@yonsei.ac.kr [Department of Biomaterials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)

2014-03-07

Highlights: • Kirenol inhibits the adipogenic transcription factors and lipogenic enzymes. • Kirenol stimulates the Wnt/β-catenin signaling pathway components. • Kirenol inhibits adipogenesis through activation of the Wnt/β-catenin signaling pathway. - Abstract: Kirenol, a natural diterpenoid compound, has been reported to possess anti-oxidant, anti-inflammatory, anti-allergic, and anti-arthritic activities; however, its anti-adipogenic effect remains to be studied. The present study evaluated the effect of kirenol on anti-adipogenesis through the activation of the Wnt/β-catenin signaling pathway. Kirenol prevented intracellular lipid accumulation by down-regulating key adipogenesis transcription factors [peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding proteins α (C/EBPα), and sterol regulatory element binding protein-1c (SREBP-1c)] and lipid biosynthesis-related enzymes [fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC)], as well as adipocytokines (adiponectin and leptin). Kirenol effectively activated the Wnt/β-catenin signaling pathway, in which kirenol up-regulated the expression of low density lipoprotein receptor related protein 6 (LRP6), disheveled 2 (DVL2), β-catenin, and cyclin D1 (CCND1), while it inactivated glycogen synthase kinase 3β (GSK3β) by increasing its phosphorylation. Kirenol down-regulated the expression levels of PPARγ and C/EBPα, which were up-regulated by siRNA knockdown of β-catenin. Overall, kirenol is capable of inhibiting the differentiation and lipogenesis of 3T3-L1 adipocytes through the activation of the Wnt/β-catenin signaling pathway, suggesting its potential as natural anti-obesity agent.

Fisetin suppresses malignant proliferation in human oral squamous cell carcinoma through inhibition of Met/Src signaling pathways.

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Li, Yan-Shu; Qin, Xing-Jun; Dai, Wei

2017-01-01

Fisetin (3,7,3',4'-tetrahydroxyflavone) is a dietary flavonoid and has been indicated as a novel anti-cancer agent in several types of cancer cells. However, the mechanisms underlying the effect of fisetin in human oral squamous cell carcinoma (OSCC) remain unclear. Here, we report that fisetin significantly inhibits tumor cell proliferation and induces apoptosis in OSCC (UM-SCC-23 and Tca-8113) cancer cell lines. Further analysis demonstrates that fisetin also inhibits Met/Src signaling pathways using the PathScan ® receptor tyrosine kinases (RTK) Signaling Antibody Array Kit. Fisetin resulted in decreased basal expression of Met and Src protein in UM-SCC-23 cancer cell lines, which validated by western blot. A student's t -test (two-tailed) was used to compare differences between groups. Furthermore, fisetin significantly inhibited the expression of a disintegrin and metalloproteinase 9 (ADAM9) protein in OSCC cells. Taken together, these results provide novel insights into the mechanism of fisetin and suggest potential therapeutic strategies for human OSCC by blocking the Met/Src signaling pathways.

Metformin inhibits inflammatory response via AMPK-PTEN pathway in vascular smooth muscle cells

Energy Technology Data Exchange (ETDEWEB)

Kim, Sun Ae [Department of Pharmacology, Aging-Associated Vascular Disease Research Center, College of Medicine, Yeungnam University, Daegu 705-717 (Korea, Republic of); Choi, Hyoung Chul, E-mail: hcchoi@med.yu.ac.kr [Department of Pharmacology, Aging-Associated Vascular Disease Research Center, College of Medicine, Yeungnam University, Daegu 705-717 (Korea, Republic of)

2012-09-07

Highlights: Black-Right-Pointing-Pointer PTEN was induced by metformin and inhibited by compound C and AMPK siRNA. Black-Right-Pointing-Pointer Metformin suppressed TNF-{alpha}-induced COX-2 and iNOS mRNA expression. Black-Right-Pointing-Pointer Compound C and bpv (pic) increased iNOS and COX-2 protein expression. Black-Right-Pointing-Pointer NF-{kappa}B activation was restored by inhibiting AMPK and PTEN. Black-Right-Pointing-Pointer AMPK and PTEN regulated TNF-{alpha}-induced ROS production in VSMCs. -- Abstract: Atherosclerosis is a chronic inflammation of the coronary arteries. Vascular smooth muscle cells (VSMCs) stimulated by cytokines and chemokines accelerate the inflammatory response and migrate to the injured endothelium during the progression of atherosclerosis. Activation of AMP activated protein kinase (AMPK), a key sensor maintaining metabolic homeostasis, suppresses the inflammatory response. However, how AMPK regulates the inflammatory response is poorly understood. To identify the mechanism of this response, we focused on phosphatase and tensin homolog (PTEN), which is a negative regulator of inflammation. We investigated that activation of AMPK-induced PTEN expression and suppression of the inflammatory response through the AMPK-PTEN pathway in VSMCs. We treated with the well-known AMPK activator metformin to induce PTEN expression. PTEN was induced by metformin (2 mM) and inhibited by compound C (10 {mu}M) and AMPK siRNA. Tumor necrosis factor-alpha (TNF-{alpha}) was used to induce inflammation. The inflammatory response was confirmed by cyclooxygenase (COX)-2, inducible nitric oxide synthase (iNOS) expression, and activation of nuclear factor (NF)-{kappa}B. Metformin suppressed COX-2 and iNOS mRNA and protein expression dose dependently. Treatment with compound C and bpv (pic) in the presence of metformin, iNOS and COX-2 protein expression increased. NF-{kappa}B activation decreased in response to metformin and was restored by inhibiting AMPK

Prenatal inhibition of the kynurenine pathway leads to structural changes in the hippocampus of adult rat offspring

OpenAIRE

Khalil, Omari S; Pisar, Mazura; Forrest, Caroline M; Vincenten, Maria C J; Darlington, L Gail; Stone, Trevor W

2014-01-01

Glutamate receptors for N-methyl-d-aspartate (NMDA) are involved in early brain development. The kynurenine pathway of tryptophan metabolism includes the NMDA receptor agonist quinolinic acid and the antagonist kynurenic acid. We now report that prenatal inhibition of the pathway in rats with 3,4-dimethoxy-N-[4-(3-nitrophenyl)thiazol-2-yl]benzenesulphonamide (Ro61-8048) produces marked changes in hippocampal neuron morphology, spine density and the immunocytochemical localisation of developme...

Loss of MAPK Pathway Activation in Post-Mitotic Retinal Cells as Mechanism in MEK Inhibition-Related Retinopathy in Cancer Patients.

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van Dijk, Elon H C; Duits, Danique E M; Versluis, Mieke; Luyten, Gregrorius P M; Bergen, Arthur A B; Kapiteijn, Ellen W; de Lange, Mark J; Boon, Camiel J F; van der Velden, Pieter A

2016-05-01

Recently, treatment with MEK inhibitors has been shown to be an effective treatment option for metastatic melanoma. Treatment efficacy is dependent on inhibition of MAPK-related melanoma proliferation. However, targeting of MEK can be accompanied by a time-dependent and reversible serous retinopathy of unknown origin.We analyzed the molecular mechanism by which the MEK inhibitor binimetinib may lead to retinopathy, using neuroretina and cell models of retinal pigment epithelium (RPE).Binimetinib inhibited the MAPK pathway while discontinuation of treatment resulted in reactivation. However, cell proliferation was not inhibited correspondingly during binimetinib treatment of ARPE19 cells. Remarkably, post-mitotic neuroretinal tissue displayed a strong MAPK activation that was lost after binimetinib treatment.We propose that binimetinib-associated retinopathy is correlated with inhibition of the MAPK pathway in multiple retinal components. Retinal cells are able to regain the activation after binimetinib treatment, mimicking the reversibility of the retinopathy. As most retinal cells are nonregenerating, other mechanisms than stimulation of proliferation must be involved.

Magnolin inhibits cell migration and invasion by targeting the ERKs/RSK2 signaling pathway

International Nuclear Information System (INIS)

Lee, Cheol-Jung; Lee, Mee-Hyun; Yoo, Sun-Mi; Choi, Kyung-Il; Song, Ji-Hong; Jang, Jeong-Hoon; Oh, Sei-Ryang; Ryu, Hyung-Won; Lee, Hye-Suk; Surh, Young-Joon; Cho, Yong-Yeon

2015-01-01

Magnolin is a natural compound abundantly found in Magnolia flos, which has been traditionally used in oriental medicine to treat headaches, nasal congestion and anti-inflammatory reactions. Our recent results have demonstrated that magnolin targets the active pockets of ERK1 and ERK2, which are important signaling molecules in cancer cell metastasis. The aim of this study is to evaluate the effects of magnolin on cell migration and to further explore the molecular mechanisms involved. Magnolin-mediated signaling inhibition was confirmed by Western blotting using RSK2 +/+ and RSK2 −/− MEFs, A549 and NCI-H1975 lung cancer cells, and by NF-κB and Cox-2 promoter luciferase reporter assays. Inhibition of cell migration by magnolin was examined by wound healing and/or Boyden Chamber assays using JB6 Cl41 and A549 human lung cancer cells. The molecular mechanisms involved in cell migration and epithelial-to-mesenchymal transition were determined by zymography, Western blotting, real-time PCR and immunocytofluorescence. Magnolin inhibited NF-κB transactivation activity by suppressing the ERKs/RSK2 signaling pathway. Moreover, magnolin abrogated the increase in EGF-induced COX-2 protein levels and wound healing. In human lung cancer cells such as A549 and NCI-H1975, which harbor constitutive active Ras and EGFR mutants, respectively, magnolin suppressed wound healing and cell invasion as seen by a Boyden chamber assay. In addition, it was observed that magnolin inhibited MMP-2 and −9 gene expression and activity. The knockdown or knockout of RSK2 in A549 lung cancer cells or MEFs revealed that magnolin targeting ERKs/RSK2 signaling suppressed epithelial-to-mesenchymal transition by modulating EMT marker proteins such as N-cadherin, E-cadherin, Snail, Vimentin and MMPs. These results demonstrate that magnolin inhibits cell migration and invasion by targeting the ERKs/RSK2 signaling pathway. The online version of this article (doi:10.1186/s12885-015-1580-7) contains

Estrogen deficiency inhibits the odonto/osteogenic differentiation of dental pulp stem cells via activation of the NF-κB pathway.

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Wang, Yanping; Yan, Ming; Yu, Yan; Wu, Jintao; Yu, Jinhua; Fan, Zhipeng

2013-06-01

Various factors can affect the functions of dental pulp stem cells (DPSCs). However, little knowledge is available about the effects of estrogen deficiency on the differentiation of DPSCs. In this study, an estrogen-deficient rat model was constructed and multi-colony-derived DPSCs were obtained from the incisors of ovariectomized (OVX) or sham-operated rats. Odonto/osteogenic differentiation and the possible involvement of the nuclear factor kappa B (NF-κB) pathway in the OVX-DPSCs/Sham-DPSCs of these rats were then investigated. OVX-DPSCs presented decreased odonto/osteogenic capacity and an activated NF-κB pathway, as compared with Sham-DPSCs. When the cellular NF-κB pathway was specifically inhibited by BMS345541, the odonto/osteogenic potential in OVX-DPSCs was significantly upregulated. Thus, estrogen deficiency down-regulated the odonto/osteogenic differentiation of DPSCs by activating NF-κB signaling and inhibition of the NF-κB pathway effectively rescued the decreased differentiation potential of DPSCs.

Huaier Extract Induces Autophagic Cell Death by Inhibiting the mTOR/S6K Pathway in Breast Cancer Cells.

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Xiaolong Wang

Full Text Available Huaier extract is attracting increased attention due to its biological activities, including antitumor, anti-parasite and immunomodulatory effects. Here, we investigated the role of autophagy in Huaier-induced cytotoxicity in MDA-MB-231, MDA-MB-468 and MCF7 breast cancer cells. Huaier treatment inhibited cell viability in all three cell lines and induced various large membranous vacuoles in the cytoplasm. In addition, electron microscopy, MDC staining, accumulated expression of autophagy markers and flow cytometry revealed that Huaier extract triggered autophagy. Inhibition of autophagy attenuated Huaier-induced cell death. Furthermore, Huaier extract inhibited the mammalian target of the rapamycin (mTOR/S6K pathway in breast cancer cells. After implanting MDA-MB-231 cells subcutaneously into the right flank of BALB/c nu/nu mice, Huaier extract induced autophagy and effectively inhibited xenograft tumor growth. This study is the first to show that Huaier-induced cytotoxicity is partially mediated through autophagic cell death in breast cancer cells through suppression of the mTOR/S6K pathway.

Transcutaneous electrical nerve stimulation attenuates CFA-induced hyperalgesia and inhibits spinal ERK1/2-COX-2 pathway activation in rats

OpenAIRE

Fang, Jun-Fan; Liang, Yi; Du, Jun-Ying; Fang, Jian-Qiao

2013-01-01

Background Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacologic treatment for pain relief. In previous animal studies, TENS effectively alleviated Complete Freund?s Adjuvant (CFA)- or carrageenan-induced inflammatory pain. Although TENS is known to produce analgesia via opioid activation in the brain and at the spinal level, few reports have investigated the signal transduction pathways mediated by TENS. Prior studies have verified the importance of the activation of extr...

Ganoderma lucidum ethanol extract inhibits the inflammatory response by suppressing the NF-κB and toll-like receptor pathways in lipopolysaccharide-stimulated BV2 microglial cells.

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Yoon, Hyun-Min; Jang, Kyung-Jun; Han, Min Seok; Jeong, Jin-Woo; Kim, Gi Young; Lee, Jai-Heon; Choi, Yung Hyun

2013-03-01

Ganoderma lucidum is a traditional Oriental medicine that has been widely used as a tonic to promote longevity and health in Korea and other Asian countries. Although a great deal of work has been carried out on the therapeutic potential of this mushroom, the pharmacological mechanisms of its anti-inflammatory actions remain unclear. In this study, we evaluated the inhibitory effects of G. lucidum ethanol extract (EGL) on the production of inflammatory mediators and cytokines in lipopolysaccharide (LPS)-stimulated murine BV2 microglia. We also investigated the effects of EGL on the LPS-induced activation of nuclear factor kappaB (NF-κB) and upregulation of toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88). Elevated levels of nitric oxide (NO), prostaglandin E(2) (PGE(2)) and pro-inflammatory cytokine production were detected in BV2 microglia following LPS stimulation. We identifed that EGL significantly inhibits the excessive production of NO, PGE(2) and pro-inflammatory cytokines, including interleukin (IL)-1β and tumor necrosis factor-α in a concentration-dependent manner without causing cytotoxicity. In addition, EGL suppressed NF-κB translocation and transcriptional activity by blocking IκB degradation and inhibiting TLR4 and MyD88 expression in LPS-stimulated BV2 cells. Our results indicate that the inhibitory effects of EGL on LPS-stimulated inflammatory responses in BV2 microglia are associated with the suppression of the NF-κB and TLR signaling pathways. Therefore, EGL may be useful in the treatment of neurodegenerative diseases by inhibiting inflammatory mediator responses in activated microglia.

DMPD: Toll-like receptors: novel pharmacological targets for the treatment ofneurological diseases. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 17974478 Toll-like receptors: novel pharmacological targets for the treatment ofneu...png) (.svg) (.html) (.csml) Show Toll-like receptors: novel pharmacological targets for the treatment ofneur...ological diseases. PubmedID 17974478 Title Toll-like receptors: novel pharmacological target

Nicotinamide inhibits vasculogenic mimicry, an alternative vascularization pathway observed in highly aggressive melanoma.

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Orit Itzhaki

Full Text Available Vasculogenic mimicry (VM describes functional vascular channels composed only of tumor cells and its presence predicts poor prognosis in melanoma patients. Inhibition of this alternative vascularization pathway might be of clinical importance, especially as several anti-angiogenic therapies targeting endothelial cells are largely ineffective in melanoma. We show the presence of VM structures histologically in a series of human melanoma lesions and demonstrate that cell cultures derived from these lesions form tubes in 3D cultures ex vivo. We tested the ability of nicotinamide, the amide form of vitamin B3 (niacin, which acts as an epigenetic gene regulator through unique cellular pathways, to modify VM. Nicotinamide effectively inhibited the formation of VM structures and destroyed already formed ones, in a dose-dependent manner. Remarkably, VM formation capacity remained suppressed even one month after the complete withdrawal of Nicotimamid. The inhibitory effect of nicotinamide on VM formation could be at least partially explained by a nicotinamide-driven downregulation of vascular endothelial cadherin (VE-Cadherin, which is known to have a central role in VM. Further major changes in the expression profile of hundreds of genes, most of them clustered in biologically-relevant clusters, were observed. In addition, nicotinamide significantly inhibited melanoma cell proliferation, but had an opposite effect on their invasion capacity. Cell cycle analysis indicated moderate changes in apoptotic indices. Therefore, nicotinamide could be further used to unravel new biological mechanisms that drive VM and tumor progression. Targeting VM, especially in combination with anti-angiogenic strategies, is expected to be synergistic and might yield substantial anti neoplastic effects in a variety of malignancies.

Pharmacological activation/inhibition of the cannabinoid system affects alcohol withdrawal-induced neuronal hypersensitivity to excitotoxic insults.

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Marina Rubio

Full Text Available Cessation of chronic ethanol consumption can increase the sensitivity of the brain to excitotoxic damages. Cannabinoids have been proposed as neuroprotectants in different models of neuronal injury, but their effect have never been investigated in a context of excitotoxicity after alcohol cessation. Here we examined the effects of the pharmacological activation/inhibition of the endocannabinoid system in an in vitro model of chronic ethanol exposure and withdrawal followed by an excitotoxic challenge. Ethanol withdrawal increased N-methyl-D-aspartate (NMDA-evoked neuronal death, probably by altering the ratio between GluN2A and GluN2B NMDA receptor subunits. The stimulation of the endocannabinoid system with the cannabinoid agonist HU-210 decreased NMDA-induced neuronal death exclusively in ethanol-withdrawn neurons. This neuroprotection could be explained by a decrease in NMDA-stimulated calcium influx after the administration of HU-210, found exclusively in ethanol-withdrawn neurons. By contrast, the inhibition of the cannabinoid system with the CB1 receptor antagonist rimonabant (SR141716 during ethanol withdrawal increased death of ethanol-withdrawn neurons without any modification of NMDA-stimulated calcium influx. Moreover, chronic administration of rimonabant increased NMDA-stimulated toxicity not only in withdrawn neurons, but also in control neurons. In summary, we show for the first time that the stimulation of the endocannabinoid system is protective against the hyperexcitability developed during alcohol withdrawal. By contrast, the blockade of the endocannabinoid system is highly counterproductive during alcohol withdrawal.

Joint inhibition of TOR and JNK pathways interacts to extend the lifespan of Brachionus manjavacas (Rotifera).

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Snell, Terry W; Johnston, Rachel K; Rabeneck, Brett; Zipperer, Cody; Teat, Stephanie

2014-04-01

marker MitoTracker and lysosome activity using LysoTracker. Treatment of rotifers with JNK inhibitor enhanced mitochondria activity nearly 3-fold, whereas rapamycin treatment had no significant effect. Treatment of rotifers with rapamycin or JNK inhibitor reduced lysosome activity in 1, 3 and 8 day old animals, but treatment with both inhibitors did not produce any additive effect. We conclude that inhibition of TOR and JNK pathways significantly extends the lifespan of B. manjavacas. These pathways interact so that inhibition of both simultaneously acts additively to extend rotifer lifespan more than the inhibition of either alone. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Curcumin Inhibits Chondrocyte Hypertrophy of Mesenchymal Stem Cells through IHH and Notch Signaling Pathways.

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Cao, Zhen; Dou, Ce; Dong, Shiwu

2017-01-01

Using tissue engineering technique to repair cartilage damage caused by osteoarthritis is a promising strategy. However, the regenerated tissue usually is fibrous cartilage, which has poor mechanical characteristics compared to hyaline cartilage. Chondrocyte hypertrophy plays an important role in this process. Thus, it is very important to find out a suitable way to maintain the phenotype of chondrocytes and inhibit chondrocyte hypertrophy. Curcumin deriving from turmeric was reported with anti-inflammatory and anti-tumor pharmacological effects. However, the role of curcumin in metabolism of chondrocytes, especially in the chondrocyte hypertrophy remains unclear. Mesenchymal stem cells (MSCs) are widely used in cartilage tissue engineering as seed cells. So we investigated the effect of curcumin on chondrogenesis and chondrocyte hypertrophy in MSCs through examination of cell viability, glycosaminoglycan synthesis and specific gene expression. We found curcumin had no effect on expression of chondrogenic markers including Sox9 and Col2a1 while hypertrophic markers including Runx2 and Col10a1 were down-regulated. Further exploration showed that curcumin inhibited chondrocyte hypertrophy through Indian hedgehog homolog (IHH) and Notch signalings. Our results indicated curcumin was a potential agent in modulating cartilage homeostasis and maintaining chondrocyte phenotype.

Fisetin inhibits laryngeal carcinoma through regulation of AKT/NF-κB/mTOR and ERK1/2 signaling pathways.

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Zhang, Xi-Jun; Jia, Shen-Shan

2016-10-01

Targeting cancer cells is crucial for improving the efficiency of laryngeal cancer treatment. However, the signaling pathway and therapeutic strategy, related to the tumor, still need further research. Dietary flavonoid fisetin (3,3',4',7-tetrahydroxyflavone) found in many fruits and vegetables has been shown in preclinical studies to inhibit cancer growth through regulating cell cycle, apoptosis, angiogenesis, invasion and metastasis without causing any toxicity to normal cells. PI3K/AKT and ERK1/2 have been known as essential signaling pathways to modulate cell proliferation, apoptosis as well as autophagy via mTOR, Caspase-3 and NF-κB signals. In our study, flow cytometry and western blot assays suggested that apoptosis was induced by fisetin administration, promoting Caspase-3 expressions by regulating PI3K/AKT/NF-κB. Additionally, fisetin suppressed TU212 cells proliferation, which was linked with ERK1/2 inactivation. Further, the activation of PI3K/AKT-regulated mTOR was inhibited by fisetin, leading to transcription suppression and proliferation inhibition of TU212 cells. In vivo studies also showed that the tumor volume and weight of nude mice were reduced for fisetin use with KI-67 decrease and LC3II increase in tumor tissue samples. Together, our data indicated that fisetin had a potential role in controlling human laryngeal cancer through inhibiting tumor cell proliferation, inducing apoptosis and autophagy regulated by ERK1/2 and AKT/NF-κB/mTOR signaling pathways, which might provide a therapeutic strategy for laryngeal cancer inhibition in future. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Porcine Circovirus-Like Virus P1 Inhibits Wnt Signaling Pathway in Vivo and in Vitro

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Xuejiao Zhu

2018-03-01

Full Text Available Porcine circovirus-like virus P1 is an important pathogen of the current pig industry, the infection mechanism is not entirely clear. Wnt signaling pathway plays an important role in the growth of young animals and infection of some viruses. This study was designed to demonstrate the effects of P1 infection on the Wnt signaling pathway. In vivo experiments, we demonstrated the down-regulatory effects of P1 infection in piglets and mice on the downstream components expression levels of Wnt signaling pathway, and the effects of Wnt signaling pathway activation on the pathogenesis of P1. In vitro studies, we found P1 infection down-regulated protein level of β-catenin and mRNA level of mmp2, prevented the β-catenin from entering into nucleus, abolished the TCF/LEF promoter activity, proved that P1 could inhibit the activation of Wnt signaling pathway in vitro. Finally, we found that VP1 of P1 virus also had the inhibitory effects on Wnt signaling pathway in vitro, elucidated the mechanism of P1’s inhibitory effects on the Wnt signaling pathway and offered the possibility that the suppression of Wnt signaling pathway was involved in the post-weaning multisystemic wasting syndrome (PMWS, laying a foundation for elucidating the pathogenesis of P1.

Arctigenin induced gallbladder cancer senescence through modulating epidermal growth factor receptor pathway.

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Zhang, Mingdi; Cai, Shizhong; Zuo, Bin; Gong, Wei; Tang, Zhaohui; Zhou, Di; Weng, Mingzhe; Qin, Yiyu; Wang, Shouhua; Liu, Jun; Ma, Fei; Quan, Zhiwei

2017-05-01

Gallbladder cancer has poor prognosis and limited therapeutic options. Arctigenin, a representative dibenzylbutyrolactone lignan, occurs in a variety of plants. However, the molecular mechanisms involved in the antitumor effect of arctigenin on gallbladder cancer have not been fully elucidated. The expression levels of epidermal growth factor receptor were examined in 100 matched pairs of gallbladder cancer tissues. A positive correlation between high epidermal growth factor receptor expression levels and poor prognosis was observed in gallbladder cancer tissues. Pharmacological inhibition or inhibition via RNA interference of epidermal growth factor receptor induced cellular senescence in gallbladder cancer cells. The antitumor effect of arctigenin on gallbladder cancer cells was primarily achieved by inducing cellular senescence. In gallbladder cancer cells treated with arctigenin, the expression level of epidermal growth factor receptor significantly decreased. The analysis of the activity of the kinases downstream of epidermal growth factor receptor revealed that the RAF-MEK-ERK signaling pathway was significantly inhibited. Furthermore, the cellular senescence induced by arctigenin could be reverted by pcDNA-epidermal growth factor receptor. Arctigenin also potently inhibited the growth of tumor xenografts, which was accompanied by the downregulation of epidermal growth factor receptor and induction of senescence. This study demonstrates arctigenin could induce cellular senescence in gallbladder cancer through the modulation of epidermal growth factor receptor pathway. These data identify epidermal growth factor receptor as a key regulator in arctigenin-induced gallbladder cancer senescence.

The Ayurvedic plant Bacopa monnieri inhibits inflammatory pathways in the brain.

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Nemetchek, Michelle D; Stierle, Andrea A; Stierle, Donald B; Lurie, Diana I

2017-02-02

Bacopa monnieri (L) Wettst (common name, bacopa) is a medicinal plant used in Ayurveda, the traditional system of medicine of India, as a nootropic. It is considered to be a "medhya rasayana", an herb that sharpens the mind and the intellect. Bacopa is an important ingredient in many Ayurvedic herbal formulations designed to treat conditions such as memory loss, anxiety, poor cognition and loss of concentration. It has also been used in Ayurveda to treat inflammatory conditions such as arthritis. In modern biomedical studies, bacopa has been shown in animal models to inhibit the release of the pro-inflammatory cytokines TNF-α and IL-6. However, less is known regarding the anti-inflammatory activity of Bacopa in the brain. The current study examines the ability of Bacopa to inhibit the release of pro-inflammatory cytokines from microglial cells, the immune cells of the brain that participate in inflammation in the CNS. The effect of Bacopa on signaling enzymes associated with CNS inflammatory pathways was also studied. Various extracts of Bacopa were prepared and examined in the N9 microglial cell line in order to determine if they inhibited the release of the proinflammatory cytokines TNF-α and IL-6. Extracts were also tested in cell free assays as inhibitors of caspase-1 and matrix metalloproteinase-3 (enzymes associated with inflammation) and caspase-3, which has been shown to cleave protein Tau, an early event in the development of Alzheimer's disease. The tea, infusion, and alkaloid extracts of bacopa, as well as Bacoside A significantly inhibited the release of TNF-α and IL-6 from activated N9 microglial cells in vitro. In addition, the tea, infusion, and alkaloid extracts of Bacopa effectively inhibited caspase 1 and 3, and matrix metalloproteinase-3 in the cell free assay. Bacopa inhibits the release of inflammatory cytokines from microglial cells and inhibits enzymes associated with inflammation in the brain. Thus, Bacopa can limit inflammation in the

The Ayurvedic plant Bacopa Monnieri inhibits inflammatory pathways in the brain

Science.gov (United States)

Nemetchek, Michelle D.; Stierle, Andrea A.; Stierle, Donald B.; Lurie, Diana I.

2016-01-01

Ethnopharmacological Relevance Bacopa monnieri (L) Wettst (common name, bacopa) is a medicinal plant used in Ayurveda, the traditional system of medicine of India, as a nootropic. It is considered to be a “medhya rasayana”, an herb that sharpens the mind and the intellect. Bacopa is an important ingredient in many Ayurvedic herbal formulations designed to treat conditions such as memory loss, anxiety, poor cognition and loss of concentration. It has also been used in Ayurveda to treat inflammatory conditions such as arthritis. In modern biomedical studies, bacopa has been shown in animal models to inhibit the release of the pro-inflammatory cytokines TNF-α and IL-6. However, less is known regarding the anti-inflammatory activity of Bacopa in the brain. Aim Of The Study The current study examines the ability of Bacopa to inhibit the release of pro-inflammatory cytokines from microglial cells, the immune cells of the brain that participate in inflammation in the CNS. The effect of Bacopa on signaling enzymes associated with CNS inflammatory pathways was also studied. Materials And Methods Various extracts of Bacopa were prepared and examined in the N9 microglial cell line in order to determine if they inhibited the release of the proinflammatory cytokines TNF-α and IL-6. Extracts were also tested in cell free assays as inhibitors of caspase-1 and matrix metalloproteinase-3 (enzymes associated with inflammation) and caspase-3, which has been shown to cleave protein Tau, an early event in the development of Alzheimer's disease. Results The tea, infusion, and alkaloid extracts of bacopa, as well as Bacoside A significantly inhibited the release of TNF-α and IL-6 from activated N9 microglial cells in vitro. In addition, the tea, infusion, and alkaloid extracts of Bacopa effectively inhibited caspase 1 and 3, and matrix metalloproteinase-3 in the cell free assay. Conclusions Bacopa inhibits the release of inflammatory cytokines from microglial cells and inhibits

Costunolide inhibits proinflammatory cytokines and iNOS in activated murine BV2 microglia.

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Rayan, Nirmala Arul; Baby, Nimmi; Pitchai, Daisy; Indraswari, Fransisca; Ling, Eng-Ang; Lu, Jia; Dheen, Thameem

2011-06-01

Costunolide, a sesquiterpene lactone present in Costus speciosus root exerts a variety of pharmacological activity but its effects on neuroinflammation have not been studied. Microglia, the resident phagocytic cells in the central nervous system respond to neuroinflammation and their overwhelming response in turn aggravate brain damage during infection, ischemia and neurodegenerative diseases. In this study, we report the effect of Costunolide on the production of proinflammatory mediators and mechanisms involved in BV2 microglial cells stimulated with LPS. Costunolide attenuated the expression of tumour necrosis factor-alpha, interleukin-1,6, inducible nitric oxide synthase, monocyte chemotactic protein 1 and cyclooxygenase 2 in activated microglia. This Costunolide-mediated inhibition was correspondent with the inhibition of NFkappaB activation. It has been further shown that Costunolide suppressed MAPK pathway activation by inducing MKP-1 production. Collectively our results suggest that Costunolide shows an ability to inhibit expression of multiple neuroinflammatory mediators and this is attributable to the compounds inhibition of NFkappaB and MAPK activation. This novel role of Costunolide upon investigation may aid in developing better therapeutic strategies for treatment of neuroinflammatory diseases.

Systematic Analysis of the Multiple Bioactivities of Green Tea through a Network Pharmacology Approach

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Shoude Zhang

2014-01-01

Full Text Available During the past decades, a number of studies have demonstrated multiple beneficial health effects of green tea. Polyphenolics are the most biologically active components of green tea. Many targets can be targeted or affected by polyphenolics. In this study, we excavated all of the targets of green tea polyphenolics (GTPs though literature mining and target calculation and analyzed the multiple pharmacology actions of green tea comprehensively through a network pharmacology approach. In the end, a total of 200 Homo sapiens targets were identified for fifteen GTPs. These targets were classified into six groups according to their related disease, which included cancer, diabetes, neurodegenerative disease, cardiovascular disease, muscular disease, and inflammation. Moreover, these targets mapped into 143 KEGG pathways, 26 of which were more enriched, as determined though pathway enrichment analysis and target-pathway network analysis. Among the identified pathways, 20 pathways were selected for analyzing the mechanisms of green tea in these diseases. Overall, this study systematically illustrated the mechanisms of the pleiotropic activity of green tea by analyzing the corresponding “drug-target-pathway-disease” interaction network.

All-trans retinoic acid inhibits craniopharyngioma cell growth: study on an explant cell model.

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Li, Qiang; You, Chao; Zhou, Liangxue; Sima, Xiutian; Liu, Zhiyong; Liu, Hao; Xu, Jianguo

2013-05-01

The ratio between FABP5 and CRABPII determines cellular response to physiological level of retinoic acid; tumor cells undergo proliferation with high level of FABP5 and apoptosis with high level of CRABPII. We intended to study FABP5 and CRABPII expression in craniopharyngiomas, to establish craniopharyngioma cell model using explants method, and to study the effect of pharmacological dose of retinoic acid on craniopharyngioma cells. Expression of FABP5 and CRABPII in craniopharyngioma tissue from 20 patients was studied using immunohistochemistry. Primary craniopharyngioma cell cultures were established using tissue explants method. Craniopharyngioma cells were treated using various concentrations of all-trans retinoic acid, and cell growth curve, apoptosis, expression of FABP5, CRABPII and NF-κB were assayed in different groups. FABP5/CRABPII ratio was significantly higher in adamatinomatous group than that in papillary group. Cell cultures were established in 19 cases (95 %). Pharmacological level retinoic acid inhibited cell growth and induced cellular apoptosis in dose dependent manner, and apoptosis rate cells treated with 30 μM retinoic acid for 24 h was 43 %. Also, retinoic acid increased CRABPII, and decreased FABP5 and NF-κB expression in craniopharyngioma cells. High FABP5/CRABPII ratio is observed in adamatinomatous craniopharyngioma. Retinoic acid at pharmacological level induced craniopharyngioma cell apoptosis via increasing FABP5/CRABPII ratio and inhibiting NF-κB signaling pathway. Our study demonstrated that all-trans retinoic acid might be a candidate for craniopharyngioma adjuvant chemotherapy in future.

Inhibition of influenza virus replication by targeting broad host cell pathways.

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Isabelle Marois

Full Text Available Antivirals that are currently used to treat influenza virus infections target components of the virus which can mutate rapidly. Consequently, there has been an increase in the number of resistant strains to one or many antivirals in recent years. Here we compared the antiviral effects of lysosomotropic alkalinizing agents (LAAs and calcium modulators (CMs, which interfere with crucial events in the influenza virus replication cycle, against avian, swine, and human viruses of different subtypes in MDCK cells. We observed that treatment with LAAs, CMs, or a combination of both, significantly inhibited viral replication. Moreover, the drugs were effective even when they were administered 8 h after infection. Finally, analysis of the expression of viral acidic polymerase (PA revealed that both drugs classes interfered with early events in the viral replication cycle. This study demonstrates that targeting broad host cellular pathways can be an efficient strategy to inhibit influenza replication. Furthermore, it provides an interesting avenue for drug development where resistance by the virus might be reduced since the virus is not targeted directly.

ALK1 signaling inhibits angiogenesis by cooperating with the Notch pathway.

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Larrivée, Bruno; Prahst, Claudia; Gordon, Emma; del Toro, Raquel; Mathivet, Thomas; Duarte, Antonio; Simons, Michael; Eichmann, Anne

2012-03-13

Activin receptor-like kinase 1 (ALK1) is an endothelial-specific member of the TGF-β/BMP receptor family that is inactivated in patients with hereditary hemorrhagic telangiectasia (HHT). How ALK1 signaling regulates angiogenesis remains incompletely understood. Here we show that ALK1 inhibits angiogenesis by cooperating with the Notch pathway. Blocking Alk1 signaling during postnatal development in mice leads to retinal hypervascularization and the appearance of arteriovenous malformations (AVMs). Combined blockade of Alk1 and Notch signaling further exacerbates hypervascularization, whereas activation of Alk1 by its high-affinity ligand BMP9 rescues hypersprouting induced by Notch inhibition. Mechanistically, ALK1-dependent SMAD signaling synergizes with activated Notch in stalk cells to induce expression of the Notch targets HEY1 and HEY2, thereby repressing VEGF signaling, tip cell formation, and endothelial sprouting. Taken together, these results uncover a direct link between ALK1 and Notch signaling during vascular morphogenesis that may be relevant to the pathogenesis of HHT vascular lesions. Copyright © 2012 Elsevier Inc. All rights reserved.

TRAIL pathway is associated with inhibition of colon cancer by protopanaxadiol

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Zhiyu Zhang

2015-01-01

Full Text Available Among important components of American ginseng, protopanaxadiol (PPD showed more active anticancer potential than other triterpenoid saponins. In this study, we determined the in vivo effects of PPD in a mouse cancer model first. Then, using human colorectal cancer cell lines, we observed significant cancer cell growth inhibition by promoting G1 cell cycle redistribution and apoptosis. Subsequently, we characterized the downstream genes targeted by PPD in HCT-116 cancer cells. Using Affymetrix high density GeneChips, we obtained the gene expression profile of the cells. Microarray data indicated that the expression levels of 76 genes were changed over two-fold after PPD, of which 52 were upregulated while the remaining 24 were downregulated. Ingenuity pathway analysis of top functions affected was carried out. Data suggested that by regulating the interactions between p53 and DR4/DR5, the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL pathway played a key role in the action of PPD, a promising colon cancer inhibitory compound.

Arctigenin Inhibits Osteoclast Differentiation and Function by Suppressing Both Calcineurin-Dependent and Osteoblastic Cell-Dependent NFATc1 Pathways

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Yamashita, Teruhito; Uehara, Shunsuke; Udagawa, Nobuyuki; Li, Feng; Kadota, Shigetoshi; Esumi, Hiroyasu; Kobayashi, Yasuhiro; Takahashi, Naoyuki

2014-01-01

Arctigenin, a lignan-derived compound, is a constituent of the seeds of Arctium lappa. Arctigenin was previously shown to inhibit osteoclastogenesis; however, this inhibitory mechanism has yet to be elucidated. Here, we showed that arctigenin inhibited the action of nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), a key transcription factor for osteoclastogenesis. NFATc1 in osteoclast precursors was activated through two distinct pathways: the calcineurin-dependent and osteoblasti...

Dexmedetomidine Inhibits Inflammatory Reaction in Lung Tissues of Septic Rats by Suppressing TLR4/NF-κB Pathway

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Yuqing Wu

2013-01-01

and 20 μg/kg significantly decreased mortality and pulmonary inflammation of septic rats, as well as suppressed CLP-induced elevation of TNF-α and IL-6 and inhibited TLR4/MyD88 expression and NF-κB activation. These results suggest that dexmedetomidine may decrease mortality and inhibit inflammatory reaction in lung tissues of septic rats by suppressing TLR4/MyD88/NF-κB pathway.

Lutein Inhibits the Migration of Retinal Pigment Epithelial Cells via Cytosolic and Mitochondrial Akt Pathways (Lutein Inhibits RPE Cells Migration

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Ching-Chieh Su

2014-08-01

Full Text Available During the course of proliferative vitreoretinopathy (PVR, the retinal pigment epithelium (RPE cells will de-differentiate, proliferate, and migrate onto the surfaces of the sensory retina. Several studies have shown that platelet-derived growth factor (PDGF can induce migration of RPE cells via an Akt-related pathway. In this study, the effect of lutein on PDGF-BB-induced RPE cells migration was examined using transwell migration assays and Western blot analyses. We found that both phosphorylation of Akt and mitochondrial translocation of Akt in RPE cells induced by PDGF-BB stimulation were suppressed by lutein. Furthermore, the increased migration observed in RPE cells with overexpressed mitochondrial Akt could also be suppressed by lutein. Our results demonstrate that lutein can inhibit PDGF-BB induced RPE cells migration through the inhibition of both cytoplasmic and mitochondrial Akt activation.

Targeting Adenosine Signaling in Parkinson's Disease: From Pharmacological to Non-pharmacological Approaches

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Luiza R. Nazario

2017-11-01

Full Text Available Parkinson's disease (PD is one of the most prevalent neurodegenerative disease displaying negative impacts on both the health and social ability of patients and considerable economical costs. The classical anti-parkinsonian drugs based in dopaminergic replacement are the standard treatment, but several motor side effects emerge during long-term use. This mini-review presents the rationale to several efforts from pre-clinical and clinical studies using adenosine receptor antagonists as a non-dopaminergic therapy. As several studies have indicated that the monotherapy with adenosine receptor antagonists reaches limited efficacy, the usage as a co-adjuvant appeared to be a promising strategy. The formulation of multi-targeted drugs, using adenosine receptor antagonists and other neurotransmitter systems than the dopaminergic one as targets, have been receiving attention since Parkinson's disease presents a complex biological impact. While pharmacological approaches to cure or ameliorate the conditions of PD are the leading strategy in this area, emerging positive aspects have arisen from non-pharmacological approaches and adenosine function inhibition appears to improve both strategies.

An Angiotensin II Type 1 Receptor Blocker Prevents Renal Injury via Inhibition of the Notch Pathway in Ins2 Akita Diabetic Mice

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Masaya Koshizaka

2012-01-01

Full Text Available Recently, it has been reported that the Notch pathway is involved in the pathogenesis of diabetic nephropathy. In this study, we investigated the activation of the Notch pathway in Ins2 Akita diabetic mouse (Akita mouse and the effects of telmisartan, an angiotensin II type1 receptor blocker, on the Notch pathway. The intracellular domain of Notch1 (ICN1 is proteolytically cleaved from the cell plasma membrane in the course of Notch activation. The expression of ICN1 and its ligand, Jagged1, were increased in the glomeruli of Akita mice, especially in the podocytes. Administration of telmisartan significantly ameliorated the expression of ICN1 and Jagged1. Telmisartan inhibited the angiotensin II-induced increased expression of transforming growth factor β and vascular endothelial growth factor A which could directly activate the Notch signaling pathway in cultured podocytes. Our results indicate that the telmisartan prevents diabetic nephropathy through the inhibition of the Notch pathway.

Use of glycolytic pathways for inhibiting or measuring oncogenic signaling

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Onodera, Yasuhito; Bissell, Mina

2017-06-27

Disclosed are methods in which glucose metabolism is correlated to oncogenesis through certain specific pathways; inhibition of certain enzymes is shown to interfere with oncogenic signaling, and measurement of certain enzyme levels is correlated with patient survival. The present methods comprise measuring level of expression of at least one of the enzymes involved in glucose uptake or metabolism, wherein increased expression of the at least one of the enzymes relative to expression in a normal cell correlates with poor prognosis of disease in a patient. Preferably the genes whose expression level is measured include GLUT3, PFKP, GAPDH, ALDOC, LDHA and GFPT2. Also disclosed are embodiments directed towards downregulating the expression of some genes in glucose uptake and metabolism.

Inhibition of inflammatory mediators contributes to the anti-inflammatory activity of KYKZL-1 via MAPK and NF-κB pathway

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Xu, Guang-Lin; Du, Yi-Fang; Cheng, Jing; Huan, Lin; Chen, Shi-Cui; Wei, Shao-Hua; Gong, Zhu-Nan; Cai, Jie; Qiu, Ting; Wu, Hao; Sun, Ting; Ao, Gui-Zhen

2013-01-01

KYKZL-1, a newly synthesized compound with COX/5-LOX dual inhibition, was subjected to the anti-inflammatory activity test focusing on its modulation of inflammatory mediators as well as intracellular MAPK and NF-κB signaling pathways. In acute ear edema model, pretreatment with KYKZL-1 (p.o.) dose-dependently inhibited the xylene-induced ear edema in mice with a higher inhibition than diclofenac. In a three-day TPA-induced inflammation, KYKZL-1 also showed significant anti-inflammatory activity with inhibition ranging between 20% and 64%. In gastric lesion test, KYKZL-1 elicited markedly fewer stomach lesions with a low index of ulcer as compared to diclofenac in rats. In further studies, KYKZL-1 was found to significantly inhibit the production of NO, PGE 2 , LTB 4 in LPS challenged RAW264.7, which is parallel to its attenuation of the expression of iNOS, COX-2, 5-LOX mRNAs or proteins and inhibition of phosphorylation of p38 and ERK MAPKs and activation of NF-κB. Taken together, our data indicate that KYKZL-1 comprises dual inhibition of COX and 5-LOX and exerts an obvious anti-inflammatory activity with an enhanced gastric safety profile via simultaneous inhibition of phosphorylation of p38 and ERK MAPKs and activation of NF-κB. - Highlights: • KYKZL-1 is designed to exhibit COX/5-LOX dual inhibition. • KYKZL-1 inhibits NO, PGE 2 and LTB 4 and iNOS, COX-2 and 5-LOX mRNAs and MAPKs. • KYKZL-1 inhibits phosphorylation of MAPKs. • KYKZL-1 inactivates NF-κB pathway

Inhibition of inflammatory mediators contributes to the anti-inflammatory activity of KYKZL-1 via MAPK and NF-κB pathway

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Xu, Guang-Lin [Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing (China); Department of Pharmacology, University of Michigan, Ann Arbor (United States); Du, Yi-Fang; Cheng, Jing; Huan, Lin [Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing (China); Chen, Shi-Cui [Jinhu Food and Drug Administration, Jiangsu (China); Wei, Shao-Hua [College of Chemistry and Materials Science, Nanjing Normal University, Nanjing (China); Gong, Zhu-Nan, E-mail: biopharmacology@126.com [Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing (China); Cai, Jie; Qiu, Ting; Wu, Hao; Sun, Ting [Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing (China); Ao, Gui-Zhen [Department of Medicinal Chemistry, School of Pharmacy, Soochow University, Jiangsu (China)

2013-10-01

KYKZL-1, a newly synthesized compound with COX/5-LOX dual inhibition, was subjected to the anti-inflammatory activity test focusing on its modulation of inflammatory mediators as well as intracellular MAPK and NF-κB signaling pathways. In acute ear edema model, pretreatment with KYKZL-1 (p.o.) dose-dependently inhibited the xylene-induced ear edema in mice with a higher inhibition than diclofenac. In a three-day TPA-induced inflammation, KYKZL-1 also showed significant anti-inflammatory activity with inhibition ranging between 20% and 64%. In gastric lesion test, KYKZL-1 elicited markedly fewer stomach lesions with a low index of ulcer as compared to diclofenac in rats. In further studies, KYKZL-1 was found to significantly inhibit the production of NO, PGE{sub 2}, LTB{sub 4} in LPS challenged RAW264.7, which is parallel to its attenuation of the expression of iNOS, COX-2, 5-LOX mRNAs or proteins and inhibition of phosphorylation of p38 and ERK MAPKs and activation of NF-κB. Taken together, our data indicate that KYKZL-1 comprises dual inhibition of COX and 5-LOX and exerts an obvious anti-inflammatory activity with an enhanced gastric safety profile via simultaneous inhibition of phosphorylation of p38 and ERK MAPKs and activation of NF-κB. - Highlights: • KYKZL-1 is designed to exhibit COX/5-LOX dual inhibition. • KYKZL-1 inhibits NO, PGE{sub 2} and LTB{sub 4} and iNOS, COX-2 and 5-LOX mRNAs and MAPKs. • KYKZL-1 inhibits phosphorylation of MAPKs. • KYKZL-1 inactivates NF-κB pathway.

mTOR pathway inhibition prevents neuroinflammation and neuronal death in a mouse model of cerebral palsy.

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Srivastava, Isha N; Shperdheja, Jona; Baybis, Marianna; Ferguson, Tanya; Crino, Peter B

2016-01-01

Mammalian target of rapamycin (mTOR) pathway signaling governs cellular responses to hypoxia and inflammation including induction of autophagy and cell survival. Cerebral palsy (CP) is a neurodevelopmental disorder linked to hypoxic and inflammatory brain injury however, a role for mTOR modulation in CP has not been investigated. We hypothesized that mTOR pathway inhibition would diminish inflammation and prevent neuronal death in a mouse model of CP. Mouse pups (P6) were subjected to hypoxia-ischemia and lipopolysaccharide-induced inflammation (HIL), a model of CP causing neuronal injury within the hippocampus, periventricular white matter, and neocortex. mTOR pathway inhibition was achieved with rapamycin (an mTOR inhibitor; 5mg/kg) or PF-4708671 (an inhibitor of the downstream p70S6kinase, S6K, 75 mg/kg) immediately following HIL, and then for 3 subsequent days. Phospho-activation of the mTOR effectors p70S6kinase and ribosomal S6 protein and expression of hypoxia inducible factor 1 (HIF-1α) were assayed. Neuronal cell death was defined with Fluoro-Jade C (FJC) and autophagy was measured using Beclin-1 and LC3II expression. Iba-1 labeled, activated microglia were quantified. Neuronal death, enhanced HIF-1α expression, and numerous Iba-1 labeled, activated microglia were evident at 24 and 48 h following HIL. Basal mTOR signaling, as evidenced by phosphorylated-S6 and -S6K levels, was unchanged by HIL. Rapamycin or PF-4,708,671 treatment significantly reduced mTOR signaling, neuronal death, HIF-1α expression, and microglial activation, coincident with enhanced expression of Beclin-1 and LC3II, markers of autophagy induction. mTOR pathway inhibition prevented neuronal death and diminished neuroinflammation in this model of CP. Persistent mTOR signaling following HIL suggests a failure of autophagy induction, which may contribute to neuronal death in CP. These results suggest that mTOR signaling may be a novel therapeutic target to reduce neuronal cell death in

TCR-CXCR4 signaling stabilizes cytokine mRNA transcripts via a PREX1-Rac1 pathway: implications for CTCL.

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Kremer, Kimberly N; Dinkel, Brittney A; Sterner, Rosalie M; Osborne, Douglas G; Jevremovic, Dragan; Hedin, Karen E

2017-08-24

As with many immunopathologically driven diseases, the malignant T cells of cutaneous T-cell lymphomas (CTCLs), such as Sézary syndrome, display aberrant cytokine secretion patterns that contribute to pathology and disease progression. Targeting this disordered release of cytokines is complicated by the changing cytokine milieu that drives the phenotypic changes of CTCLs. Here, we characterize a novel signaling pathway that can be targeted to inhibit the secretion of cytokines by modulating either CXCR4 or CXCR4-mediated signaling. We demonstrate that upon ligation of the T-cell antigen receptor (TCR), the TCR associates with and transactivates CXCR4 via phosphorylation of S339-CXCR4 in order to activate a PREX1-Rac1-signaling pathway that stabilizes interleukin-2 (IL-2) , IL-4 , and IL-10 messenger RNA (mRNA) transcripts. Pharmacologic inhibition of either TCR-CXCR4 complex formation or PREX1-Rac1 signaling in primary human T cells decreased mRNA stability and inhibited secretion of IL-2, IL-4, and IL-10. Applying this knowledge to Sézary syndrome, we demonstrate that targeting various aspects of this signaling pathway blocks both TCR-dependent and TCR-independent cytokine secretion from a Sézary syndrome-derived cell line and patient isolates. Together, these results identify multiple aspects of a novel TCR-CXCR4-signaling pathway that could be targeted to inhibit the aberrant cytokine secretion that drives the immunopathogenesis of Sézary syndrome and other immunopathological diseases. © 2017 by The American Society of Hematology.

The selective estrogen receptor modulator raloxifene inhibits neutrophil extracellular trap formation.

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Roxana Flores

2016-12-01

Full Text Available Raloxifene is a selective estrogen receptor modulator typically prescribed for the prevention/treatment of osteoporosis in postmenopausal women. Although raloxifene is known to have anti-inflammatory properties, its effect on human neutrophils, the primary phagocytic leukocytes of the immune system, remain poorly understood. Here, through a screen of pharmacologically active small molecules, we find that raloxifene prevents neutrophil cell death in response to the classical activator phorbol 12-myristate 13-acetate (PMA, a compound known to induce formation of DNA-based neutrophil extracellular traps (NETs. Inhibition of PMA-induced NET production by raloxifene was confirmed using quantitative and imaging-based assays. Human neutrophils from both male and female donors express the nuclear estrogen receptors ERα and ERβ, known targets of raloxifene. Like raloxifene, selective antagonists of these receptors inhibit PMA-induced NET production. Furthermore, raloxifene inhibited PMA-induced ERK phosphorylation but not reactive oxygen species (ROS production, pathways known to be key modulators of NET production. Finally, we found that raloxifene inhibited PMA-induced, NET-based killing of the leading human bacterial pathogen, methicillin-resistant Staphylococcus aureus (MRSA. Our results reveal that raloxifene is a potent modulator of neutrophil function and NET production.

Inhibition of SLC1A5 sensitizes colorectal cancer to cetuximab.

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Ma, Huanrong; Wu, Zhenzhen; Peng, Jianjun; Li, Yang; Huang, Hongxiang; Liao, Yi; Zhou, Minyu; Sun, Li; Huang, Na; Shi, Min; Bin, Jianping; Liao, Yulin; Rao, Jinjun; Wang, Lin; Liao, Wangjun

2018-06-15

Cetuximab resistance is a key barrier in treating metastatic colorectal cancer (mCRC). Targeting of metabolic resources import could resensitize drug-resistant cancer cells to anticancer treatments. Here we showed that the expression of the glutamine transporter solute carrier 1 family member 5 (SLC1A5) in clinical CRC samples of patients resisted to cetuximab was significantly higher than in those of patients responded to cetuximab. Inhibition of SLC1A5 by shRNA-mediated gene silencing or pharmacological inhibitor significantly suppressed the growth of CRC. Moreover, inhibition of SLC1A5 significantly enhanced the inhibitory efficacy of cetuximab on CRC proliferation both in vitro and in vivo. Mechanistically, SLC1A5 inhibition facilitated EGFR degradation through the ubiquitin-proteasome pathway, and decreased the expression of nuclear EGFR, both of which might have contribution to the improved response to cetuximab. This study provides the metabolic molecule SLC1A5 as a potential therapeutic target to increase the efficacy of cetuximab on CRC. © 2018 UICC.

Kruppel-like factor 2 inhibit the angiogenesis of cultured human liver sinusoidal endothelial cells through the ERK1/2 signaling pathway

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Zeng, Xiao-Qing, E-mail: zeng.xiaoqing@zs-hospital.sh.cn [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Li, Na, E-mail: Linala.2009@163.com [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Pan, Du-Yi, E-mail: lasikesmi@hotmail.com [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Miao, Qing, E-mail: sadsadvenus@163.com [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Ma, Gui-Fen, E-mail: ma.guifen@zs-hospital.sh.cn [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Liu, Yi-Mei, E-mail: liuyimei1988@163.com [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Tseng, Yu-Jen, E-mail: dianatseng14@gmail.com [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Li, Feng, E-mail: li.feng2@zs-hospital.sh.cn [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Xu, Li-Li, E-mail: xu.lili3@zs-hospital.sh.cn [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Chen, Shi-Yao, E-mail: chen.shiyao@zs-hospital.sh.cn [Department of Gastroenterology of Zhongshan Hospital, Fudan University, Shanghai (China); Institute of Endoscopic Research of Zhongshan Hospital, Fudan University, Shanghai (China)

2015-09-04

Kruppel-like factor 2 (KLF2) is a crucial anti-angiogenic factor. However, its precise role in hepatic angiogenesis induced by liver sinusoidal endothelial cells (LSECs) remain unclear. This study was aimed to evaluate the effect of KLF2 on angiogenesis of LSECs and to explore the corresponding mechanism. Cultured human LSECs were infected with different lentiviruses to overexpress or suppress KLF2 expression. The CCK-8 assay, transwell migration assay and tube formation test, were used to investigate the roles of KLF2 in the proliferation, migration and vessel tube formation of LSECs, respectively. The expression and phosphorylation of ERK1/2 were detected by western blot. We discovered that the up-regulation of KLF2 expression dramatically inhibited proliferation, migration and tube formation in treated LSECs. Correspondingly, down-regulation of KLF2 expression significantly promoted proliferation, migration and tube formation in treated LSECs. Additionally, KLF2 inhibited the phosphorylation of ERK1/2 pathway, followed by the function of KLF2 in the angiogenesis of LSECs disrupted. In conclusion, KLF2 suppressed the angiogenesis of LSECs through inhibition of cell proliferation, migration, and vessel tube formation. These functions of KLF2 may be mediated through the ERK1/2 signaling pathway. - Highlights: • Overexpression of KLF2 inhibits the proliferation and migration of LSECs. • Overexpression of KLF2 inhibits the angiogenesis of LSECs. • ERK1/2 signaling pathway involved in the anti-angiogenic process of KLF2 on LSECs.

State-dependent compound inhibition of Nav1.2 sodium channels using the FLIPR Vm dye: on-target and off-target effects of diverse pharmacological agents.

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Benjamin, Elfrida R; Pruthi, Farhana; Olanrewaju, Shakira; Ilyin, Victor I; Crumley, Gregg; Kutlina, Elena; Valenzano, Kenneth J; Woodward, Richard M

2006-02-01

Voltage-gated sodium channels (NaChs) are relevant targets for pain, epilepsy, and a variety of neurological and cardiac disorders. Traditionally, it has been difficult to develop structure-activity relationships for NaCh inhibitors due to rapid channel kinetics and state-dependent compound interactions. Membrane potential (Vm) dyes in conjunction with a high-throughput fluorescence imaging plate reader (FLIPR) offer a satisfactory 1st-tier solution. Thus, the authors have developed a FLIPR Vm assay of rat Nav1.2 NaCh. Channels were opened by addition of veratridine, and Vm dye responses were measured. The IC50 values from various structural classes of compounds were compared to the resting state binding constant (Kr)and inactivated state binding constant (Ki)obtained using patch-clamp electrophysiology (EP). The FLIPR values correlated with Ki but not Kr. FLIPRIC50 values fell within 0.1-to 1.5-fold of EP Ki values, indicating that the assay generally reports use-dependent inhibition rather than resting state block. The Library of Pharmacologically Active Compounds (LOPAC, Sigma) was screened. Confirmed hits arose from diverse classes such as dopamine receptor antagonists, serotonin transport inhibitors, and kinase inhibitors. These data suggest that NaCh inhibition is inherent in a diverse set of biologically active molecules and may warrant counterscreening NaChs to avoid unwanted secondary pharmacology.

A Comprehensive Review of Punica granatum (Pomegranate) Properties in Toxicological, Pharmacological, Cellular and Molecular Biology Researches

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Rahimi, Hamid Reza; Arastoo, Mohammad; Ostad, Seyed Nasser

2012-01-01

Punica granatum (Pg), commonly known as pomegranate (Pg), is a member of the monogeneric family, Punicaceae, and is mainly found in Iran which is considered to be its primary centre of origin. Pg and its chemical components possess various pharmacological and toxicological properties including antioxidant, anti-inflammatory (by inhibiting pro-inflammatory cytokines), anti-cancer and anti-angiogenesis activities. They also show inhibitory effects on invasion/motility, cell cycle, apoptosis, and vital enzymes such as cyclooxygenase (COX), lipooxygenase (LOX), cytochrome P450 (CYP450), phospholipase A2 (PLA2), ornithine decarboxylase (ODC), carbonic anhydrase (CA), 17beta-hydroxysteroid dehydrogenase (17β-HSDs) and serine protease (SP). Furthermore, they can stimulate cell differentiation and possess anti-mutagenic effects. Pg can also interfere with several signaling pathways including PI3K/AKT, mTOR, PI3K, Bcl-X, Bax, Bad, MAPK, ERK1/2, P38, JNK, and caspase. However, the exact mechanisms for its pharmacological and toxicological properties remain to be unclear and need further evaluation. These properties strongly suggest a wide range use of Pg for clinical applications. This review will discuss the areas for which Pg has shown therapeutic properties in different mechanisms. PMID:24250463

PKI-587 and sorafenib targeting PI3K/AKT/mTOR and Ras/Raf/MAPK pathways synergistically inhibit HCC cell proliferation.

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Gedaly, Roberto; Angulo, Paul; Hundley, Jonathan; Daily, Michael F; Chen, Changguo; Evers, B Mark

2012-08-01

Deregulated Ras/Raf/MAPK and PI3K/AKT/mTOR signaling pathways are found in hepatocellular carcinoma (HCC). This study aimed to test the inhibitory effects of PKI-587 and sorafenib as single agents or in combination on HCC (Huh7 cell line) proliferation. (3)H-thymidine incorporation and MTT assay were used to assess Huh7 cell proliferation. Phosphorylation of the key enzymes in the Ras/Raf/MAPK and PI3K/AKT/mTOR pathways was detected by Western blot. We found that PKI-587 is a more potent PI3K/mTOR inhibitor than PI-103. Combination of PKI-587 and sorafenib was a more effective inhibitor of Huh7 proliferation than the combination of PI-103 and sorafenib. Combination of PKI-587 and sorafenib synergistically inhibited epidermal growth factor (EGF)-stimulated Huh7 proliferation compared with monodrug therapy. EGF increased phosphorylation of Ras/Raf downstream signaling proteins MEK and ERK; EGF-stimulated activation was inhibited by sorafenib. However, sorafenib, as a single agent, increased AKT (Ser473) phosphorylation. EGF-stimulated AKT (ser473) activation was inhibited by PKI-587. PKI-587 is a potent inhibitor of AKT (Ser473), mTOR (Ser2448), and S6K (Thr389) phosphorylation; in contrast, rapamycin stimulated mTOR complex 2 substrate AKT(Ser473) phosphorylation although it inhibited mTOR complex 1 substrate S6K phosphorylation. PKI-587, as a single agent, stimulated MEK and ERK phosphorylation. However, when PKI-587 and sorafenib were used in combination, they inhibited all the tested kinases in the Ras/Raf /MAPK and PI3K/AKT/mTOR pathways. The combination of PKI-587 and sorafenib has the advantage over monodrug therapy on inhibition of HCC cell proliferation by blocking both PI3K/AKT/mTOR and Ras/Raf/MAPK signaling pathways. Copyright © 2012 Elsevier Inc. All rights reserved.

Molecular mechanisms of resistance to Rituximab and pharmacologic strategies for its circumvention.

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Stolz, Claudia; Schuler, Martin

2009-06-01

The introduction of Rituximab has greatly improved therapeutic options for patients with B-cell non-Hodgkin lymphoma (B-NHL). However, a substantial fraction of patients with aggressive B-NHL fails first-line therapy, and most patients with relapsing indolent B-NHL eventually acquire Rituximab resistance. Molecular understanding of the underlying mechanisms facilitates the development of pharmacologic strategies to overcome resistance. Rituximab exerts its activity on CD20-expressing B-cells by indirect and direct effector mechanisms. Indirect mechanisms are complement-dependent cytotoxicity (CDC), and antibody-dependent cell-mediated cytotoxicity (ADCC). Direct activities, such as growth inhibition, induction of apoptosis and chemosensitisation, have been reported, but are less defined. Moreover, the relative contribution of CDC, ADCC and direct mechanisms to the activity of Rituximab in vivo is unclear. Down-regulation of CD20 and expression of complement inhibitors have been described as escape mechanisms in B-NHL. Recent reports suggest that deregulated phosphoinositide-3-kinase (PI3K)/Akt, mitogen-activated kinases (MAPK) and nuclear-factor kappaB (NF-kappaB), as well as up-regulation of anti-apoptotic proteins may determine the efficacy of Rituximab to kill B-NHL cells in vitro and in vivo. The latter signalling pathways are attractive targets for pharmacologic modulation of resistance to Rituximab. With the advent of new inhibitors and antibodies, rationally designed clinical trials addressing Rituximab resistance are feasible.

Lithium inhibits tumorigenic potential of PDA cells through targeting hedgehog-GLI signaling pathway.

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Zhonglu Peng

Full Text Available Hedgehog signaling pathway plays a critical role in the initiation and development of pancreatic ductal adenocarcinoma (PDA and represents an attractive target for PDA treatment. Lithium, a clinical mood stabilizer for mental disorders, potently inhibits the activity of glycogen synthase kinase 3β (GSK3β that promotes the ubiquitin-dependent proteasome degradation of GLI1, an important downstream component of hedgehog signaling. Herein, we report that lithium inhibits cell proliferation, blocks G1/S cell-cycle progression, induces cell apoptosis and suppresses tumorigenic potential of PDA cells through down-regulation of the expression and activity of GLI1. Moreover, lithium synergistically enhances the anti-cancer effect of gemcitabine. These findings further our knowledge of mechanisms of action for lithium and provide a potentially new therapeutic strategy for PDA through targeting GLI1.

Genetic Deletion and Pharmacological Inhibition of PI3Kγ Reduces Neutrophilic Airway Inflammation and Lung Damage in Mice with Cystic Fibrosis-Like Lung Disease

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Maria Galluzzo

2015-01-01

Full Text Available Purpose. Neutrophil-dominated airway inflammation is a key feature of progressive lung damage in cystic fibrosis (CF. Thus, reducing airway inflammation is a major goal to prevent lung damage in CF. However, current anti-inflammatory drugs have shown several limits. PI3Kγ plays a pivotal role in leukocyte recruitment and activation; in the present study we determined the effects of genetic deletion and pharmacologic inhibition of PI3Kγ on airway inflammation and structural lung damage in a mouse model of CF lung disease. Methods. βENaC overexpressing mice (βENaC-Tg were backcrossed with PI3Kγ-deficient (PI3KγKO mice. Tissue damage was assessed by histology and morphometry and inflammatory cell number was evaluated in bronchoalveolar lavage fluid (BALF. Furthermore, we assessed the effect of a specific PI3Kγ inhibitor (AS-605240 on inflammatory cell number in BALF. Results. Genetic deletion of PI3Kγ decreased neutrophil numbers in BALF of PI3KγKO/βENaC-Tg mice, and this was associated with reduced emphysematous changes. Treatment with the PI3Kγ inhibitor AS-605240 decreased the number of neutrophils in BALF of βENaC-Tg mice, reproducing the effect observed with genetic deletion of the enzyme. Conclusions. These results demonstrate the biological efficacy of both genetic deletion and pharmacological inhibition of PI3Kγ in reducing chronic neutrophilic inflammation in CF-like lung disease in vivo.

Noninvasive Assessment of Gastric Emptying by Near-Infrared Fluorescence Reflectance Imaging in Mice: Pharmacological Validation with Tegaserod, Cisapride, and Clonidine

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Hans-Ulrich Gremlich

2004-10-01

Full Text Available Noninvasive near-infrared fluorescence reflectance imaging (FRI is an in vivo technique to assess physiological and molecular processes in the intact organism. Here we describe a method to assess gastric emptying in mice. TentaGel™ beads with covalently bound cyanine dye (Cy5.5 conjugates as fluorescent probe were administered by oral gavage. The amount of intragastric beads/label was derived from the fluorescence signal intensity measured in a region of interest corresponding to the mouse stomach. The FRI signal intensity decreased as a function of time reflecting gastric emptying. In control mice, the gastric half-emptying time was in agreement with literature data. Pharmacological modulation of gastric motility allowed the evaluation of the sensitivity of the FRI-based method. Gastric emptying was either stimulated or inhibited by treatment with the 5-HT4 receptor agonists tegaserod (Zelnorm® and cisapride or the α2-receptor agonist clonidine, respectively. Tegaserod and cisapride dose-dependently accelerated gastric emptying. In contrast, clonidine dose-dependently delayed gastric emptying. In conclusion, FRI using fluorescently labeled beads allows the reliable determination of gastric emptying as well as the assessment of pharmacological interventions. The technique thus offers the potential to characterize molecular targets and pathways involved in physiological regulation and pharmacological modulation of gastric emptying.

B-cell translocation gene 3 overexpression inhibits proliferation and invasion of colorectal cancer SW480 cells via Wnt/β-catenin signaling pathway.

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Mao, D; Qiao, L; Lu, H; Feng, Y

2016-01-01

Increasing evidences have shown that B-cell translocation gene 3 (BTG3) inhibits metastasis of multiple cancer cells. However, the role of BTG3 in colorectal cancer (CRC) and its possible mechanism have not yet been reported. In our study, we evaluated BTG3 expression in several CRC cell lines. Then, pcDNA3.1-BTG3 was transfected into SW480 cells. We found that BTG3 was upregulated in SW480 cells after overexpression plasmid transfection. BTG3 overexpression significantly inhibited cell growth and decreased PCNA (proliferating cell nuclear antigen) and Ki67 levels. BTG3 overexpression markedly downregulated Cyclin D1 and Cyclin E1 levels, whereas elevated p27. Overexpression of BTG3 arrested the cell cycle at G1 phase, which was abrogated by p27 silencing. Furthermore, migration, invasion and EMT of SW480 cells were significantly suppressed by BTG3 overexpression. Further investigations showed the inhibition of Wnt/β-catenin signaling pathway. We then used GSK3β specific inhibitor SB-216763 to activate the Wnt/β-catenin signaling pathway. We found that Wnt/β-catenin signaling pathway activation reversed the effect of BTG3 overexpression on cell proliferation, cell cycle progression, invasion and EMT. In conclusion, BTG3 overexpression inhibited cell growth, induced cell cycle arrest and suppressed the metastasis of SW480 cells via the Wnt/β-catenin signaling pathway. BTG3 may be considered as a therapeutic target in CRC treatment.

Therapeutic effects of antibiotic drug tigecycline against cervical squamous cell carcinoma by inhibiting Wnt/β-catenin signaling

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Li, Hui; Jiao, Shun [Department of Obstetrics and Gynaecology, JingZhou Hospital Affiliated to Huazhong University of Science and Technology, Jingzhou (China); Li, Xin [Department of Obstetrics and Gynaecology, RenMin Hospital of Wuhan University, Wuhan (China); Banu, Hasina; Hamal, Shreejana [Department of Clinical Medicine, Medical School of Yangtze University, Jingzhou (China); Wang, Xianrong, E-mail: Dr.XianRong.Wang@hotmail.com [Department of Obstetrics and Gynaecology, JingZhou Hospital Affiliated to Huazhong University of Science and Technology, Jingzhou (China)

2015-11-06

Aberrant activation of the Wnt/β-catenin signaling pathway is common in human cervical cancers and has great potential therapeutic value. We show that tigecycline, a FDA-approved antibiotic drug, targets cervical squamous cell carcinoma through inhibiting Wnt/β-catenin signaling pathway. Tigecycline is effective in inducing apoptosis, inhibiting proliferation and anchorage-independent colony formation of Hela cells. The inhibitory effects of tigecycline are further enhanced upon combination with paclitaxel, a most commonly used chemotherapeutic drug for cervical cancer. In a cervical xenograft model, tigecycline inhibits tumor growth as a single agent and its combination with paclitaxel significantly inhibits more tumor growth throughout the duration of treatment. We further show that tigecycline decreases level of both cytoplasmic and nuclear β-catenin and suppressed Wnt/β-catenin-mediated transcription through increasing levels of Axin 1 in Hela cells. In addition, stabilization or overexpression of β-catenin using pharmacological and genetic approaches abolished the effects of tigecycline in inhibiting proliferation and inducing apoptosis of Hela cells. Our study suggests that tigecycline is a useful addition to the treatment armamentarium for cervical cancer and targeting Wnt/β-catenin represents a potential therapeutic strategy in cervical cancer. - Highlights: • We repurposed the antibiotic drug tigecycline for cervical cancer treatment. • Tigecycline is effectively against cervical cancer cells in vitro and in vivo. • Combination of tigecycline and paclitaxel is synergistic in targeting Hela cells. • Tigecycline acts on Hela cells through inhibiting Wnt/β-catenin signaling.

Therapeutic effects of antibiotic drug tigecycline against cervical squamous cell carcinoma by inhibiting Wnt/β-catenin signaling

International Nuclear Information System (INIS)

Li, Hui; Jiao, Shun; Li, Xin; Banu, Hasina; Hamal, Shreejana; Wang, Xianrong

2015-01-01

Aberrant activation of the Wnt/β-catenin signaling pathway is common in human cervical cancers and has great potential therapeutic value. We show that tigecycline, a FDA-approved antibiotic drug, targets cervical squamous cell carcinoma through inhibiting Wnt/β-catenin signaling pathway. Tigecycline is effective in inducing apoptosis, inhibiting proliferation and anchorage-independent colony formation of Hela cells. The inhibitory effects of tigecycline are further enhanced upon combination with paclitaxel, a most commonly used chemotherapeutic drug for cervical cancer. In a cervical xenograft model, tigecycline inhibits tumor growth as a single agent and its combination with paclitaxel significantly inhibits more tumor growth throughout the duration of treatment. We further show that tigecycline decreases level of both cytoplasmic and nuclear β-catenin and suppressed Wnt/β-catenin-mediated transcription through increasing levels of Axin 1 in Hela cells. In addition, stabilization or overexpression of β-catenin using pharmacological and genetic approaches abolished the effects of tigecycline in inhibiting proliferation and inducing apoptosis of Hela cells. Our study suggests that tigecycline is a useful addition to the treatment armamentarium for cervical cancer and targeting Wnt/β-catenin represents a potential therapeutic strategy in cervical cancer. - Highlights: • We repurposed the antibiotic drug tigecycline for cervical cancer treatment. • Tigecycline is effectively against cervical cancer cells in vitro and in vivo. • Combination of tigecycline and paclitaxel is synergistic in targeting Hela cells. • Tigecycline acts on Hela cells through inhibiting Wnt/β-catenin signaling.

Inhibition of ERK1/2 or AKT Activity Equally Enhances Radiation Sensitization in B16F10 Cells

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Kalal, Bhuvanesh Sukhlal; Fathima, Faraz; Pai, Vinitha Ramanath; Sanjeev, Ganesh; Krishna, Chilakapati Murali; Upadhya, Dinesh

2018-01-01

Background The aim of the study was to evaluate the radiation sensitizing ability of ERK1/2, PI3K-AKT and JNK inhibitors in highly radiation resistant and metastatic B16F10 cells which carry wild-type Ras and Braf. Methods Mouse melanoma cell line B16F10 was exposed to 1.0, 2.0 and 3.0 Gy of electron beam radiation. Phosphorylated ERK1/2, AKT and JNK levels were estimated by ELISA. Cells were exposed to 2.0 and 3.0 Gy of radiation with or without prior pharmacological inhibition of ERK1/2, AKT as well as JNK pathways. Cell death induced by radiation as well as upon inhibition of these pathways was measured by TUNEL assay using flow cytometry. Results Exposure of B16F10 cells to 1.0, 2.0 and 3.0 Gy of electron beam irradiation triggered an increase in all the three phosphorylated proteins compared to sham-treated and control groups. B16F10 cells pre-treated with either ERK1/2 or AKT inhibitors equally enhanced radiation-induced cell death at 2.0 as well as 3.0 Gy (P < 0.001), while inhibition of JNK pathway increased radiation-induced cell death to a lesser extent. Interestingly combined inhibition of ERK1/2 or AKT pathways did not show additional cell death compared to individual ERK1/2 or AKT inhibition. This indicates that ERK1/2 or AKT mediates radiation resistance through common downstream molecules in B16F10 cells. Conclusions Even without activating mutations in Ras or Braf genes, ERK1/2 and AKT play a critical role in B16F10 cell survival upon radiation exposure and possibly act through common downstream effector/s. PMID:29581812

The mitochondrial translocator protein, TSPO, inhibits HIV-1 envelope glycoprotein biosynthesis via the endoplasmic reticulum-associated protein degradation pathway.

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Zhou, Tao; Dang, Ying; Zheng, Yong-Hui

2014-03-01

The HIV-1 Env glycoprotein is folded in the endoplasmic reticulum (ER), which is necessary for viral entry and replication. Currently, it is still unclear how this process is regulated. The glycoprotein folding in the ER is controlled by the ER-associated protein degradation (ERAD) pathway, which specifically targets misfolded proteins for degradation. Previously, we reported that HIV-1 replication is restricted in the human CD4(+) T cell line CEM.NKR (NKR). To understand this mechanism, we first analyzed cellular protein expression in NKR cells and discovered that levels of the mitochondrial translocator protein TSPO were upregulated by ∼64-fold. Notably, when NKR cells were treated with TSPO antagonist PK-11195, Ro5-4864, or diazepam, HIV restriction was completely disrupted, and TSPO knockdown by short hairpin RNAs (shRNAs) achieved a similar effect. We next analyzed viral protein expression, and, interestingly, we discovered that Env expression was specifically inhibited. Both TSPO knockdown and treatment with TSPO antagonist could restore Env expression in NKR cells. We further discovered that Env proteins were rapidly degraded and that kifunensine, an ERAD pathway inhibitor, could restore Env expression and viral replication, indicating that Env proteins were misfolded and degraded through the ERAD pathway in NKR cells. We also knocked out the TSPO gene in 293T cells using CRISPR/Cas9 (clustered, regularly interspaced, short palindromic repeat [CRISPR]/CRISPR-associated-9) technology and found that TSPO could similarly inhibit Env expression in these cells. Taken together, these results demonstrate that TSPO inhibits Env protein expression through the ERAD pathway and suggest that mitochondria play an important role in regulating the Env folding process. The HIV-1 Env glycoprotein is absolutely required for viral infection, and an understanding of its expression pathway in infected cells will identify new targets for antiretroviral therapies. Env proteins

Salinomycin, a polyether ionophoric antibiotic, inhibits adipogenesis

International Nuclear Information System (INIS)

Szkudlarek-Mikho, Maria; Saunders, Rudel A.; Yap, Sook Fan; Ngeow, Yun Fong; Chin, Khew-Voon

2012-01-01

Highlights: ► Salinomycin inhibits preadipocyte differentiation into adipocytes. ► Salinomycin inhibits transcriptional regulation of adipogenesis. ► Pharmacological effects of salinomycin suggest toxicity in cancer therapy. -- Abstract: The polyether ionophoric antibiotics including monensin, salinomycin, and narasin, are widely used in veterinary medicine and as food additives and growth promoters in animal husbandry including poultry farming. Their effects on human health, however, are not fully understood. Recent studies showed that salinomycin is a cancer stem cell inhibitor. Since poultry consumption has risen sharply in the last three decades, we asked whether the consumption of meat tainted with growth promoting antibiotics might have effects on adipose cells. We showed in this report that the ionophoric antibiotics inhibit the differentiation of preadipocytes into adipocytes. The block of differentiation is not due to the induction of apoptosis nor the inhibition of cell proliferation. In addition, salinomycin also suppresses the transcriptional activity of the CCAAT/enhancer binding proteins and the peroxisome proliferator-activated receptor γ. These results suggest that the ionophoric antibiotics can be exploited as novel anti-obesity therapeutics and as pharmacological probes for the study of adipose biology. Further, the pharmacological effects of salinomycin could be a harbinger of its toxicity on the adipose tissue and other susceptible target cells in cancer therapy.

Gamabufotalin, a major derivative of bufadienolide, inhibits VEGF-induced angiogenesis by suppressing VEGFR-2 signaling pathway.

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Tang, Ning; Shi, Lei; Yu, Zhenlong; Dong, Peipei; Wang, Chao; Huo, Xiaokui; Zhang, Baojing; Huang, Shanshan; Deng, Sa; Liu, Kexin; Ma, Tonghui; Wang, Xiaobo; Wu, Lijun; Ma, Xiao-Chi

2016-01-19

Gamabufotalin (CS-6), a main active compound isolated from Chinese medicine Chansu, has been shown to strongly inhibit cancer cell growth and inflammatory response. However, its effects on angiogenesis have not been known yet. Here, we sought to determine the biological effects of CS-6 on signaling mechanisms during angiogenesis. Our present results fully demonstrate that CS-6 could significantly inhibit VEGF triggered HUVECs proliferation, migration, invasion and tubulogenesis in vitro and blocked vascularization in Matrigel plugs impregnated in C57/BL6 mice as well as reduced vessel density in human lung tumor xenograft implanted in nude mice. Computer simulations revealed that CS-6 interacted with the ATP-binding sites of VEGFR-2 using molecular docking. Furthermore, western blot analysis indicated that CS-6 inhibited VEGF-induced phosphorylation of VEGFR-2 kinase and suppressed the activity of VEGFR-2-mediated signaling cascades. Therefore, our studies demonstrated that CS-6 inhibited angiogenesis by inhibiting the activation of VEGFR-2 signaling pathways and CS-6 could be a potential candidate in angiogenesis-related disease therapy.

Pharmacological effects and potential therapeutic targets of DT-13.

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Khan, Ghulam Jilany; Rizwan, Mohsin; Abbas, Muhammad; Naveed, Muhammad; Boyang, Yu; Naeem, Muhammad Ahsan; Khan, Sara; Yuan, Shengtao; Baig, Mirza Muhammad Faran Ashraf; Sun, Li

2018-01-01

DT-13 is an isolated compound from Dwarf lillytruf tuber and currently among active research drugs by National Natural Science foundation of China for its several potential effects. The drug has been reported for its multiple pharmacological actions however no thorough review studies are available on it. Our present study is highlighting the pros and cons of DT-13 focusing on its potential pharmacological actions, therapeutic utilization and further exploration for novel targets. The drug possesses very low toxicity profile, quick onset and long duration of action with slow elimination that combinely makes it favorable for the clinical studies. In vivo and in vitro studies show that the drug regulates multiple cellular functions for its several pharmacological effects including, anti-adhesive effects via regulation of tissue factor and transforming growth factor; anti-migratory effects through indirect regulation of NM-IIA in the tumor microenvironment, Tissue factor, down-regulation of CCR5-CCL5 axis and MMP-2/9 inhibition; anti-metastatic effects via regulation of MMPs and tissue factor; pro-apoptotic effects by modulation of endocytosis of EGF receptor; anti-angiogenic effects via regulation of HIF-1α,ERK, Akt signalling and autophagy inducing characteristics by regulating PI3K/Akt/mTOR signalling pathway. In addition to anti-tumor activities, DT-13 has significant anti-inflammatory, cardioprotective, hepatoprotective and immunomodulating effects. Pharmaceutical dosage form and targeted drug delivery system for DT-13 has not been established yet. Moreover, DT-13, has not been studied for its action on brain, colorectal, hepatic, pancreatic, prostate and blood cancers. Similarly the effects of drug on carbohydrate and glucose metabolism is another niche yet to be explored. In some traditional therapies, crude drug from the plant is used against diabetic and neurological disorders that are not reported in scientific literature, however due to profound effects of

Dimethyl Fumarate Inhibits the Nuclear Factor κB Pathway in Breast Cancer Cells by Covalent Modification of p65 Protein.

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Kastrati, Irida; Siklos, Marton I; Calderon-Gierszal, Esther L; El-Shennawy, Lamiaa; Georgieva, Gergana; Thayer, Emily N; Thatcher, Gregory R J; Frasor, Jonna

2016-02-12

In breast tumors, activation of the nuclear factor κB (NFκB) pathway promotes survival, migration, invasion, angiogenesis, stem cell-like properties, and resistance to therapy--all phenotypes of aggressive disease where therapy options remain limited. Adding an anti-inflammatory/anti-NFκB agent to breast cancer treatment would be beneficial, but no such drug is approved as either a monotherapy or adjuvant therapy. To address this need, we examined whether dimethyl fumarate (DMF), an anti-inflammatory drug already in clinical use for multiple sclerosis, can inhibit the NFκB pathway. We found that DMF effectively blocks NFκB activity in multiple breast cancer cell lines and abrogates NFκB-dependent mammosphere formation, indicating that DMF has anti-cancer stem cell properties. In addition, DMF inhibits cell proliferation and significantly impairs xenograft tumor growth. Mechanistically, DMF prevents p65 nuclear translocation and attenuates its DNA binding activity but has no effect on upstream proteins in the NFκB pathway. Dimethyl succinate, the inactive analog of DMF that lacks the electrophilic double bond of fumarate, is unable to inhibit NFκB activity. Also, the cell-permeable thiol N-acetyl l-cysteine, reverses DMF inhibition of the NFκB pathway, supporting the notion that the electrophile, DMF, acts via covalent modification. To determine whether DMF interacts directly with p65, we synthesized and used a novel chemical probe of DMF by incorporating an alkyne functionality and found that DMF covalently modifies p65, with cysteine 38 being essential for the activity of DMF. These results establish DMF as an NFκB inhibitor with anti-tumor activity that may add therapeutic value in the treatment of aggressive breast cancers. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Exposure of Human Lung Cells to Tobacco Smoke Condensate Inhibits the Nucleotide Excision Repair Pathway.

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Nathaniel Holcomb

Full Text Available Exposure to tobacco smoke is the number one risk factor for lung cancer. Although the DNA damaging properties of tobacco smoke have been well documented, relatively few studies have examined its effect on DNA repair pathways. This is especially true for the nucleotide excision repair (NER pathway which recognizes and removes many structurally diverse DNA lesions, including those introduced by chemical carcinogens present in tobacco smoke. The aim of the present study was to investigate the effect of tobacco smoke on NER in human lung cells. We studied the effect of cigarette smoke condensate (CSC, a surrogate for tobacco smoke, on the NER pathway in two different human lung cell lines; IMR-90 lung fibroblasts and BEAS-2B bronchial epithelial cells. To measure NER, we employed a slot-blot assay to quantify the introduction and removal of UV light-induced 6-4 photoproducts and cyclobutane pyrimidine dimers. We find a dose-dependent inhibition of 6-4 photoproduct repair in both cell lines treated with CSC. Additionally, the impact of CSC on the abundance of various NER proteins and their respective RNAs was investigated. The abundance of XPC protein, which is required for functional NER, is significantly reduced by treatment with CSC while the abundance of XPA protein, also required for NER, is unaffected. Both XPC and XPA RNA levels are modestly reduced by CSC treatment. Finally, treatment of cells with MG-132 abrogates the reduction in the abundance of XPC protein produced by treatment with CSC, suggesting that CSC enhances proteasome-dependent turnover of the protein that is mediated by ubiquitination. Together, these findings indicate that tobacco smoke can inhibit the same DNA repair pathway that is also essential for the removal of some of the carcinogenic DNA damage introduced by smoke itself, increasing the DNA damage burden of cells exposed to tobacco smoke.

Pharmacological approach to acute pancreatitis

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Bang, U.C.; Semb, S.; Nøjgaard, Camilla

2008-01-01

The aim of the present review is to summarize the current knowledge regarding pharmacological prevention and treatment of acute pancreatitis (AP) based on experimental animal models and clinical trials. Somatostatin (SS) and octreotide inhibit the exocrine production of pancreatic enzymes and may...... be useful as prophylaxis against post endoscopic retrograde cholangiopancreatography pancreatitis (PEP). The protease inhibitor gabexate mesilate (GM) is used routinely as treatment to AP in some countries, but randomized clinical trials and a meta-analysis do not support this practice. Nitroglycerin (NGL...

Curcumin ameliorates diabetic nephropathy by inhibiting the activation of the SphK1-S1P signaling pathway.

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Huang, Juan; Huang, Kaipeng; Lan, Tian; Xie, Xi; Shen, Xiaoyan; Liu, Peiqing; Huang, Heqing

2013-01-30

Curcumin, a major polyphenol from the golden spice Curcuma longa commonly known as turmeric, has been recently discovered to have renoprotective effects on diabetic nephropathy (DN). However, the mechanisms underlying these effects remain unclear. We previously demonstrated that the sphingosine kinase 1-sphingosine 1-phosphate (SphK1-S1P) signaling pathway plays a pivotal role in the pathogenesis of DN. This study aims to investigate whether the renoprotective effects of curcumin on DN are associated with its inhibitory effects on the SphK1-S1P signaling pathway. Our results demonstrated that the expression and activity of SphK1 and the production of S1P were significantly down-regulated by curcumin in diabetic rat kidneys and glomerular mesangial cells (GMCs) exposed to high glucose (HG). Simultaneously, SphK1-S1P-mediated fibronectin (FN) and transforming growth factor-beta 1 (TGF-β1) overproduction were inhibited. In addition, curcumin dose dependently reduced SphK1 expression and activity in GMCs transfected with SphK(WT) and significantly suppressed the increase in SphK1-mediated FN levels. Furthermore, curcumin inhibited the DNA-binding activity of activator protein 1 (AP-1), and c-Jun small interference RNA (c-Jun-siRNA) reversed the HG-induced up-regulation of SphK1. These findings suggested that down-regulation of the SphK1-S1P pathway is probably a novel mechanism by which curcumin improves the progression of DN. Inhibiting AP-1 activation is one of the therapeutic targets of curcumin to modulate the SphK1-S1P signaling pathway, thereby preventing diabetic renal fibrosis. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

TLR4 Signaling Pathway Modulators as Potential Therapeutics in Inflammation and Sepsis

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Nikolay N. Kuzmich

2017-10-01

Full Text Available Toll-Like Receptor 4 (TLR4 signal pathway plays an important role in initiating the innate immune response and its activation by bacterial endotoxin is responsible for chronic and acute inflammatory disorders that are becoming more and more frequent in developed countries. Modulation of the TLR4 pathway is a potential strategy to specifically target these pathologies. Among the diseases caused by TLR4 abnormal activation by bacterial endotoxin, sepsis is the most dangerous one because it is a life-threatening acute system inflammatory condition that still lacks specific pharmacological treatment. Here, we review molecules at a preclinical or clinical phase of development, that are active in inhibiting the TLR4-MyD88 and TLR4-TRIF pathways in animal models. These are low-molecular weight compounds of natural and synthetic origin that can be considered leads for drug development. The results of in vivo studies in the sepsis model and the mechanisms of action of drug leads are presented and critically discussed, evidencing the differences in treatment results from rodents to humans.

Excess thyroid hormone inhibits embryonic neural stem/progenitor cells proliferation and maintenance through STAT3 signalling pathway.

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Chen, Chunhai; Zhou, Zhou; Zhong, Min; Li, Maoquan; Yang, Xuesen; Zhang, Yanwen; Wang, Yuan; Wei, Aimin; Qu, Mingyue; Zhang, Lei; Xu, Shangcheng; Chen, Shude; Yu, Zhengping

2011-07-01

Hyperthyroidism is prevalent during pregnancy, but little is known about the effects of excess thyroid hormone on the development of embryonic neural stem/progenitor cells (NSCs), and the mechanisms underlying these effects. Previous studies indicate that STAT3 plays a crucial role in determining NSC fate during neurodevelopment. In this study, we investigated the effects of a supraphysiological dose of 3,5,3'-L-triiodothyronine (T3) on the proliferation and maintenance of NSCs derived from embryonic day 13.5 mouse neocortex, and the involvement of STAT3 in this process. Our results suggest that excess T3 treatment inhibits NSC proliferation and maintenance. T3 decreased tyrosine phosphorylation of JAK1, JAK2 and STAT3, and subsequently inhibited STAT3-DNA binding activity. Furthermore, proliferation and maintenance of NSCs were decreased by inhibitors of JAKs and STAT3, indicating that the STAT3 signalling pathway is involved in the process of NSC proliferation and maintenance. Taken together, these results suggest that the STAT3 signalling pathway is involved in the process of T3-induced inhibition of embryonic NSC proliferation and maintenance. These findings provide data for understanding the effects of hyperthyroidism during pregnancy on fetal brain development, and the mechanisms underlying these effects.

Pharmacology of dextromethorphan: Relevance to dextromethorphan/quinidine (Nuedexta®) clinical use.

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Taylor, Charles P; Traynelis, Stephen F; Siffert, Joao; Pope, Laura E; Matsumoto, Rae R

2016-08-01

Dextromethorphan (DM) has been used for more than 50years as an over-the-counter antitussive. Studies have revealed a complex pharmacology of DM with mechanisms beyond blockade of N-methyl-d-aspartate (NMDA) receptors and inhibition of glutamate excitotoxicity, likely contributing to its pharmacological activity and clinical potential. DM is rapidly metabolized to dextrorphan, which has hampered the exploration of DM therapy separate from its metabolites. Coadministration of DM with a low dose of quinidine inhibits DM metabolism, yields greater bioavailability and enables more specific testing of the therapeutic properties of DM apart from its metabolites. The development of the drug combination DM hydrobromide and quinidine sulfate (DM/Q), with subsequent approval by the US Food and Drug Administration for pseudobulbar affect, led to renewed interest in understanding DM pharmacology. This review summarizes the interactions of DM with brain receptors and transporters and also considers its metabolic and pharmacokinetic properties. To assess the potential clinical relevance of these interactions, we provide an analysis comparing DM activity from in vitro functional assays with the estimated free drug DM concentrations in the brain following oral DM/Q administration. The findings suggest that DM/Q likely inhibits serotonin and norepinephrine reuptake and also blocks NMDA receptors with rapid kinetics. Use of DM/Q may also antagonize nicotinic acetylcholine receptors, particularly those composed of α3β4 subunits, and cause agonist activity at sigma-1 receptors. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Pharmacology and function of melatonin receptors

International Nuclear Information System (INIS)

Dubocovich, M.L.

1988-01-01

The hormone melatonin is secreted primarily from the pineal gland, with highest levels occurring during the dark period of a circadian cycle. This hormone, through an action in the brain, appears to be involved in the regulation of various neural and endocrine processes that are cued by the daily change in photoperiod. This article reviews the pharmacological characteristics and function of melatonin receptors in the central nervous system, and the role of melatonin in mediating physiological functions in mammals. Melatonin and melatonin agonists, at picomolar concentrations, inhibit the release of dopamine from retina through activation of a site that is pharmacologically different from a serotonin receptor. These inhibitory effects are antagonized by the novel melatonin receptor antagonist luzindole (N-0774), which suggests that melatonin activates a presynaptic melatonin receptor. In chicken and rabbit retina, the pharmacological characteristics of the presynaptic melatonin receptor and the site labeled by 2-[125I]iodomelatonin are identical. It is proposed that 2-[125I]iodomelatonin binding sites (e.g., chicken brain) that possess the pharmacological characteristics of the retinal melatonin receptor site (order of affinities: 2-iodomelatonin greater than 6-chloromelatonin greater than or equal to melatonin greater than or equal to 6,7-di-chloro-2-methylmelatonin greater than 6-hydroxymelatonin greater than or equal to 6-methoxymelatonin greater than N-acetyltryptamine greater than or equal to luzindole greater than N-acetyl-5-hydroxytryptamine greater than 5-methoxytryptamine much greater than 5-hydroxytryptamine) be classified as ML-1 (melatonin 1). The 2-[125I]iodomelatonin binding site of hamster brain membranes possesses different binding and pharmacological characteristics from the retinal melatonin receptor site and should be classified as ML-2. 64 references

Inwardly Rectifying Potassium (Kir) Channels Represent a Critical Ion Conductance Pathway in the Nervous Systems of Insects.

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Chen, Rui; Swale, Daniel R

2018-01-25

A complete understanding of the physiological pathways critical for proper function of the insect nervous system is still lacking. The recent development of potent and selective small-molecule modulators of insect inward rectifier potassium (Kir) channels has enabled the interrogation of the physiological role and toxicological potential of Kir channels within various insect tissue systems. Therefore, we aimed to highlight the physiological and functional role of neural Kir channels the central nervous system, muscular system, and neuromuscular system through pharmacological and genetic manipulations. Our data provide significant evidence that Drosophila neural systems rely on the inward conductance of K + ions for proper function since pharmacological inhibition and genetic ablation of neural Kir channels yielded dramatic alterations of the CNS spike discharge frequency and broadening and reduced amplitude of the evoked EPSP at the neuromuscular junction. Based on these data, we conclude that neural Kir channels in insects (1) are critical for proper function of the insect nervous system, (2) represents an unexplored physiological pathway that is likely to shape the understanding of neuronal signaling, maintenance of membrane potentials, and maintenance of the ionic balance of insects, and (3) are capable of inducing acute toxicity to insects through neurological poisoning.

Mechanisms involved in growth inhibition induced by clofibrate in hepatoma cells

International Nuclear Information System (INIS)

Muzio, Giuliana; Maggiora, Marina; Trombetta, Antonella; Martinasso, Germana; Reffo, Patrizia; Colombatto, Sebastiano; Canuto, Rosa Angela

2003-01-01

Low concentrations of some peroxisome proliferators have been found to decrease apoptosis in rat liver cells, whereas higher but pharmacological concentrations have been found to inhibit cell proliferation or to induce apoptosis in human and rat hepatoma cells. The highly deviated JM2 rat hepatoma cell line was used to examine the mechanisms underlying the inhibitory effect on cell proliferation. Clofibrate chiefly inhibited cell proliferation in these cells. Parallel to the decrease in cell proliferation there was an increase of peroxisome proliferator activated receptor (PPAR) gamma and of protein phosphatase 2A, whose importance was confirmed, respectively, by using antisense oliginucleotides (AS-ODN) or okadaic acid. The increase of protein phosphatase 2A induced by PPARgamma caused a decrease of MAPK, an intracellular signaling transduction pathway, as shown by evaluation of Erk1,2 and c-myc. In light of these results, clofibrate, like conventional synthetic ligands of PPARgamma, may be regarded as a possible prototype anti-tumour drug

Andrographolide ameliorates diabetic nephropathy by attenuating hyperglycemia-mediated renal oxidative stress and inflammation via Akt/NF-κB pathway.

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Ji, Xiaoqian; Li, Changzheng; Ou, Yitao; Li, Ning; Yuan, Kai; Yang, Guizhi; Chen, Xiaoyan; Yang, Zhicheng; Liu, Bing; Cheung, Wai W; Wang, Lijing; Huang, Ren; Lan, Tian

2016-12-05

Diabetic nephropathy (DN) is characterized by proliferation of mesangial cells, mesangial hypertrophy and extracellular matrix (ECM) accumulation. Our recent study found that andrographolide inhibited high glucose-induced mesangial cell proliferation and fibronectin expression through inhibition of AP-1 pathway. However, whether andrographolide has reno-protective roles in DN has not been fully elucidated. Here, we studied the pharmacological effects of andrographolide against the progression of DN and high glucose-induced mesangial dysfunction. Diabetes was induced in C57BL/6 mice by intraperitoneal injection of streptozotocin (STZ). After 1 weeks after STZ injection, normal diet was substituted with a high-fat diet (HFD). Diabetic mice were intraperitoneal injected with andrographolide (2 mg/kg, twice a week). After 8 weeks, functional and histological analyses were carried out. Parallel experiments uncovering the molecular mechanism by which andrographolide prevents from DN was performed in mesangial cells. Andrographolide inhibited the increases in fasting blood glucose, triglyceride, kidney/body weight ratio, blood urea nitrogen, serum creatinine and 24-h albuminuria in diabetic mice. Andrographolide also prevented renal hypertrophy and ECM accumulation. Furthermore, andrographolide markedly attenuated NOX1 expression, ROS production and pro-inflammatory cytokines as well. Additionally, andrographolide inhibited Akt/NF-κB signaling pathway. These results demonstrate that andrographolide is protective against the progression of experimental DN by inhibiting renal oxidative stress, inflammation and fibrosis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Tributyltin and triphenyltin inhibit osteoclast differentiation through a retinoic acid receptor-dependent signaling pathway

International Nuclear Information System (INIS)

Yonezawa, Takayuki; Hasegawa, Shin-ichi; Ahn, Jae-Yong; Cha, Byung-Yoon; Teruya, Toshiaki; Hagiwara, Hiromi; Nagai, Kazuo; Woo, Je-Tae

2007-01-01

Organotin compounds, such as tributyltin (TBT) and triphenyltin (TPT), have been widely used in agriculture and industry. Although these compounds are known to have many toxic effects, including endocrine-disrupting effects, their effects on bone resorption are unknown. In this study, we investigated the effects of organotin compounds, such as monobutyltin (MBT), dibutyltin (DBT), TBT, and TPT, on osteoclast differentiation using mouse monocytic RAW264.7 cells. MBT and DBT had no effects, whereas TBT and TPT dose-dependently inhibited osteoclast differentiation at concentrations of 3-30 nM. Treatment with a retinoic acid receptor (RAR)-specific antagonist, Ro41-5253, restored the inhibition of osteoclastogenesis by TBT and TPT. TBT and TPT reduced receptor activator of nuclear factor-κB ligand (RANKL) induced nuclear factor of activated T cells (NFAT) c1 expression, and the reduction in NFATc1 expression was recovered by Ro41-5253. Our results suggest that TBT and TPT suppress osteoclastogenesis by inhibiting RANKL-induced NFATc1 expression via an RAR-dependent signaling pathway

Ethanol Decreases Inflammatory Response in Human Lung Epithelial Cells by Inhibiting the Canonical NF-kB-Pathway

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Katharina Mörs

2017-08-01

Full Text Available Background/Aims: Alcohol (ethanol, EtOH as significant contributor to traumatic injury is linked to suppressed inflammatory response, thereby influencing clinical outcomes. Alcohol-induced immune-suppression during acute inflammation (trauma was linked to nuclear factor-kappaB (NF-ĸB. Here, we analyzed alcohol`s effects and mechanisms underlying its influence on NF-ĸB-signaling during acute inflammation in human lung epithelial cells. Methods: A549-cells were stimulated with interleukin (IL-1β, or sera from trauma patients (TP or healthy volunteers, with positive/negative blood alcohol concentrations (BAC, and subsequently exposed to EtOH (170 Mm, 1h. IL-6-release and neutrophil adhesion to A549 were analyzed. Specific siRNA-NIK mediated downregulation of non-canonical, and IKK-NBD-inhibition of canonical NF-ĸB signaling were performed. Nuclear levels of activated p50 and p52 NF-ĸB-subunits were detected using TransAm ELISA. Results: Both stimuli significantly induced IL-6-release (39.79±4.70 vs. 0.58±0.8 pg/ml and neutrophil adhesion (132.30±8.80 vs. 100% control, p<0.05 to A549-cells. EtOH significantly decreased IL-6-release (22.90±5.40, p<0.05 and neutrophil adherence vs. controls (105.40±14.5%, p<0.05. IL-1β-induced significant activation of canonical/p50 and non-canonical/p52 pathways. EtOH significantly reduced p50 (34.90±23.70 vs. 197.70±36.43, p<0.05 not p52 activation. Inhibition of canonical pathway was further increased by EtOH (less p50-activation, while p52 remained unaltered. Inhibition of non-canonical pathway was unchanged by EtOH. Conclusion: Here, alcohol`s anti-inflammatory effects are mediated via decreasing nuclear levels of activated p50-subunit and canonical NF-ĸB signaling pathway.

Ethanol Decreases Inflammatory Response in Human Lung Epithelial Cells by Inhibiting the Canonical NF-kB-Pathway.

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Mörs, Katharina; Hörauf, Jason-Alexander; Kany, Shinwan; Wagner, Nils; Sturm, Ramona; Woschek, Mathias; Perl, Mario; Marzi, Ingo; Relja, Borna

2017-01-01

Alcohol (ethanol, EtOH) as significant contributor to traumatic injury is linked to suppressed inflammatory response, thereby influencing clinical outcomes. Alcohol-induced immune-suppression during acute inflammation (trauma) was linked to nuclear factor-kappaB (NF-ĸB). Here, we analyzed alcohol`s effects and mechanisms underlying its influence on NF-ĸB-signaling during acute inflammation in human lung epithelial cells. A549-cells were stimulated with interleukin (IL)-1β, or sera from trauma patients (TP) or healthy volunteers, with positive/negative blood alcohol concentrations (BAC), and subsequently exposed to EtOH (170 Mm, 1h). IL-6-release and neutrophil adhesion to A549 were analyzed. Specific siRNA-NIK mediated downregulation of non-canonical, and IKK-NBD-inhibition of canonical NF-ĸB signaling were performed. Nuclear levels of activated p50 and p52 NF-ĸB-subunits were detected using TransAm ELISA. Both stimuli significantly induced IL-6-release (39.79±4.70 vs. 0.58±0.8 pg/ml) and neutrophil adhesion (132.30±8.80 vs. 100% control, p<0.05) to A549-cells. EtOH significantly decreased IL-6-release (22.90±5.40, p<0.05) and neutrophil adherence vs. controls (105.40±14.5%, p<0.05). IL-1β-induced significant activation of canonical/p50 and non-canonical/p52 pathways. EtOH significantly reduced p50 (34.90±23.70 vs. 197.70±36.43, p<0.05) not p52 activation. Inhibition of canonical pathway was further increased by EtOH (less p50-activation), while p52 remained unaltered. Inhibition of non-canonical pathway was unchanged by EtOH. Here, alcohol`s anti-inflammatory effects are mediated via decreasing nuclear levels of activated p50-subunit and canonical NF-ĸB signaling pathway. © 2017 The Author(s). Published by S. Karger AG, Basel.

Salicortin inhibits osteoclast differentiation and bone resorption by down-regulating JNK and NF-κB/NFATc1 signaling pathways

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Nie, Shaobo [Department of Orthopaedics, PLA General Hospital, Beijing 100853 (China); Xu, Jiawei [Department of Orthopaedics, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Zhang, Chenghua [Department of Orthopaedics, Changle County Hospital of Traditional Chinese Medicine, Weifang 262400 (China); Xu, Chen [Department of Orthopaedics, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Liu, Ming, E-mail: ming_li4717@sina.com [Department of Orthopaedics, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Yu, Degang, E-mail: ydg163@126.com [Department of Orthopaedics, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China)

2016-01-29

Receptor activator of nuclear factor (NF)-κB ligand (RANKL)-activated signaling is essential for osteoclast differentiation, activation, and survival. Salicortin is a phenolic glycoside that has been isolated from many plants such as Populus and Salix species, and has been shown to have anti-amnesic and anti-adipogenic effects. In this study, we investigated the effect of salicortin on RANKL-induced osteoclasts formation, bone resorption, and activation of osteoclast-related signaling pathways. Salicortin suppressed RANKL-induced osteoclastogenesis in bone marrow macrophage cultures in a dose-dependent manner, and inhibited osteoclastic bone resorption activity without any cytotoxicity. Salicortin inhibited RANKL-induced c-Jun N-terminal kinase and NF-κB activation, concomitant with retarded IκBα phosphorylation and inhibition of p65 nuclear translocation, leading to impaired transcription of nuclear factor of activated T cells c1 (NFATc1) and expression of osteoclastic-specific genes. Taken together, our findings demonstrate that salicortin inhibits NF-κB and NFATc1 activation, leading to attenuation of osteoclastogenesis and bone resorption. Thus, salicortin may be of interest in developments of treatment for osteoclast related diseases. - Highlights: • Salicortin suppresses osteoclastogenesis in vitro. • Salicortin impairs the JNK and NF-κB/NFATc1 signaling pathway. • Salicortin may be of interest in developments of osteoporosis treatment.

Salicortin inhibits osteoclast differentiation and bone resorption by down-regulating JNK and NF-κB/NFATc1 signaling pathways

International Nuclear Information System (INIS)

Nie, Shaobo; Xu, Jiawei; Zhang, Chenghua; Xu, Chen; Liu, Ming; Yu, Degang

2016-01-01

Receptor activator of nuclear factor (NF)-κB ligand (RANKL)-activated signaling is essential for osteoclast differentiation, activation, and survival. Salicortin is a phenolic glycoside that has been isolated from many plants such as Populus and Salix species, and has been shown to have anti-amnesic and anti-adipogenic effects. In this study, we investigated the effect of salicortin on RANKL-induced osteoclasts formation, bone resorption, and activation of osteoclast-related signaling pathways. Salicortin suppressed RANKL-induced osteoclastogenesis in bone marrow macrophage cultures in a dose-dependent manner, and inhibited osteoclastic bone resorption activity without any cytotoxicity. Salicortin inhibited RANKL-induced c-Jun N-terminal kinase and NF-κB activation, concomitant with retarded IκBα phosphorylation and inhibition of p65 nuclear translocation, leading to impaired transcription of nuclear factor of activated T cells c1 (NFATc1) and expression of osteoclastic-specific genes. Taken together, our findings demonstrate that salicortin inhibits NF-κB and NFATc1 activation, leading to attenuation of osteoclastogenesis and bone resorption. Thus, salicortin may be of interest in developments of treatment for osteoclast related diseases. - Highlights: • Salicortin suppresses osteoclastogenesis in vitro. • Salicortin impairs the JNK and NF-κB/NFATc1 signaling pathway. • Salicortin may be of interest in developments of osteoporosis treatment.

Inhibition of peroxynitrite-mediated DNA strand cleavage and hydroxyl radical formation by aspirin at pharmacologically relevant concentrations: Implications for cancer intervention

Energy Technology Data Exchange (ETDEWEB)

Chen, Wei [Division of Biomedical Sciences, Edward Via Virginia College of Osteopathic Medicine, Virginia Tech Corporate Research Center, Blacksburg, VA 24060 (United States); College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310035 (China); Department of Food Science and Technology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Zhu, Hong; Jia, Zhenquan [Division of Biomedical Sciences, Edward Via Virginia College of Osteopathic Medicine, Virginia Tech Corporate Research Center, Blacksburg, VA 24060 (United States); Li, Jianrong [College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310035 (China); Misra, Hara P. [Division of Biomedical Sciences, Edward Via Virginia College of Osteopathic Medicine, Virginia Tech Corporate Research Center, Blacksburg, VA 24060 (United States); Zhou, Kequan, E-mail: kzhou@wayne.edu [Department of Nutrition and Food Science, Wayne State University, Detroit, MI 48202 (United States); Li, Yunbo, E-mail: yli@vcom.vt.edu [Division of Biomedical Sciences, Edward Via Virginia College of Osteopathic Medicine, Virginia Tech Corporate Research Center, Blacksburg, VA 24060 (United States)

2009-12-04

Epidemiological studies have suggested that the long-term use of aspirin is associated with a decreased incidence of human malignancies, especially colorectal cancer. Since accumulating evidence indicates that peroxynitrite is critically involved in multistage carcinogenesis, this study was undertaken to investigate the ability of aspirin to inhibit peroxynitrite-mediated DNA damage. Peroxynitrite and its generator 3-morpholinosydnonimine (SIN-1) were used to cause DNA strand breaks in {phi}X-174 plasmid DNA. We demonstrated that the presence of aspirin at concentrations (0.25-2 mM) compatible with amounts in plasma during chronic anti-inflammatory therapy resulted in a significant inhibition of DNA cleavage induced by both peroxynitrite and SIN-1. Moreover, the consumption of oxygen caused by 250 {mu}M SIN-1 was found to be decreased in the presence of aspirin, indicating that aspirin might affect the auto-oxidation of SIN-1. Furthermore, EPR spectroscopy using 5,5-dimethylpyrroline-N-oxide (DMPO) as a spin trap demonstrated the formation of DMPO-hydroxyl radical adduct (DMPO-OH) from authentic peroxynitrite, and that aspirin at 0.25-2 mM potently diminished the radical adduct formation in a concentration-dependent manner. Taken together, these results demonstrate for the first time that aspirin at pharmacologically relevant concentrations can inhibit peroxynitrite-mediated DNA strand breakage and hydroxyl radical formation. These results may have implications for cancer intervention by aspirin.

Inhibition of peroxynitrite-mediated DNA strand cleavage and hydroxyl radical formation by aspirin at pharmacologically relevant concentrations: Implications for cancer intervention

International Nuclear Information System (INIS)

Chen, Wei; Zhu, Hong; Jia, Zhenquan; Li, Jianrong; Misra, Hara P.; Zhou, Kequan; Li, Yunbo

2009-01-01

Epidemiological studies have suggested that the long-term use of aspirin is associated with a decreased incidence of human malignancies, especially colorectal cancer. Since accumulating evidence indicates that peroxynitrite is critically involved in multistage carcinogenesis, this study was undertaken to investigate the ability of aspirin to inhibit peroxynitrite-mediated DNA damage. Peroxynitrite and its generator 3-morpholinosydnonimine (SIN-1) were used to cause DNA strand breaks in φX-174 plasmid DNA. We demonstrated that the presence of aspirin at concentrations (0.25-2 mM) compatible with amounts in plasma during chronic anti-inflammatory therapy resulted in a significant inhibition of DNA cleavage induced by both peroxynitrite and SIN-1. Moreover, the consumption of oxygen caused by 250 μM SIN-1 was found to be decreased in the presence of aspirin, indicating that aspirin might affect the auto-oxidation of SIN-1. Furthermore, EPR spectroscopy using 5,5-dimethylpyrroline-N-oxide (DMPO) as a spin trap demonstrated the formation of DMPO-hydroxyl radical adduct (DMPO-OH) from authentic peroxynitrite, and that aspirin at 0.25-2 mM potently diminished the radical adduct formation in a concentration-dependent manner. Taken together, these results demonstrate for the first time that aspirin at pharmacologically relevant concentrations can inhibit peroxynitrite-mediated DNA strand breakage and hydroxyl radical formation. These results may have implications for cancer intervention by aspirin.

Polymeric black tea polyphenols inhibit 1,2-dimethylhydrazine induced colorectal carcinogenesis by inhibiting cell proliferation via Wnt/β-catenin pathway

International Nuclear Information System (INIS)

Patel, Rachana; Ingle, Arvind; Maru, Girish B.

2008-01-01

Tea polyphenols like epigallocatechin gallate and theaflavins are established chemopreventive agents for colorectal carcinogenesis. However, studies on evaluating similar chemopreventive properties of thearubigins or polymeric black tea polyphenols (PBPs), the most abundant polyphenols in black tea, are limited. Hence, in the present study we aim to investigate chemopreventive effects along with probable mechanisms of action of PBP extract employing 1,2-dimethylhydrazine (DMH)-induced colorectal carcinogenesis in Sprague-Dawley rats as experimental model. The present study suggests that PBPs, like other tea polyphenols, also inhibit DMH-induced colorectal tumorigenesis by decreasing tumor volume and multiplicity. This study also shows that although the pretreatment with PBP extract could induce detoxifying enzymes in hepatic and colorectal tissue, it did not show any additional chemopreventive effects when compared to treatments with PBP extract after initiation with DMH. Mechanistically, PBP extract may inhibit colorectal carcinogenesis by decreasing DMH-induced cell proliferation via Wnt/β-catenin pathway. Treatments with PBP extract showed decreased levels of COX-2, c-MYC and cyclin D1 proteins which aid cell proliferation probably by regulating β-catenin by maintaining expression of APC and decreasing inactivation of GSK3β. DMH-induced activation of MAP kinases such as ERK and JNK was also found to be inhibited by treatments with PBP extract. In conclusion, the protective effects of PBP extract could be attributed to inhibition of DMH-induced cellular proliferation probably through β-catenin regulation

Glaucocalyxin A inhibits platelet activation and thrombus formation preferentially via GPVI signaling pathway.

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Wei Li

Full Text Available Platelets play a pivotal role in atherothrombosis and the antiplatelet agents have been proved to be useful in preventing onset of acute clinical events including myocardial infarction and stroke. Increasing number of natural compounds has been identified to be potential antiplatelet agents. Here we report the antiplatelet effect of glaucocalyxin A (GLA, an ent-diterpenoid that we isolated and purified from the aerial parts of Rabdosia japonica (Burm. f. var. glaucocalyx (Maxim. Hara, and investigate the molecular mechanisms by which GLA inhibits platelet activation and thrombus formation. The effect of GLA on platelet activation was measured using platelets freshly isolated from peripheral blood of healthy donors. Results showed that pretreatment of human platelets with lower concentrations of GLA (0.01 μg/ml, 0.1 μg/ml significantly inhibited platelet aggregation induced by collagen (P<0.001 and CRP (P<0.01, a synthetic GPVI ligand, but not by ADP and U46619. Accordingly, GLA inhibited collagen-stimulated tyrosine phosphorylation of Syk, LAT, and phospholipase Cγ2, the signaling events in collagen receptor GPⅥ pathway. GLA also inhibited platelet p-selectin secretion and integrin activation by convulxin, a GPVI selective ligand. Additionally, GLA was found to inhibit low-dose thrombin-induced platelet activation. Using a flow chamber device, GLA was found to attenuate platelet adhesion on collagen surfaces in high shear condition. In vivo studies showed that GLA administration increased the time for complete occlusion upon vascular injury in mice, but did not extend tail-bleeding time when mice were administered with relatively lower doses of GLA. Therefore, the present results provide the molecular basis for the inhibition effect of GLA on platelet activation and its in vivo effect on thrombus formation, suggesting that GLA could potentially be developed as an antiplatelet and antithrombotic agent.

Caffeine inhibits STAT1 signaling and downregulates inflammatory pathways involved in autoimmunity.

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Iris, Merve; Tsou, Pei-Suen; Sawalha, Amr H

2018-04-18

Caffeine is a widely consumed pharmacologically active product. We focused on characterizing immunomodulatory effects of caffeine on peripheral blood mononuclear cells. Caffeine at high doses showed a robust downregulatory effect on cytokine activity and genes related to several autoimmune diseases including lupus and rheumatoid arthritis. Dose-dependent validation experiments showed downregulation at the mRNA levels of key inflammation-related genes including STAT1, TNF, IFNG, and PPARG. TNF and PPARG were suppressed even with the lowest caffeine dose tested, which corresponds to the serum concentration of caffeine after administration of one cup of coffee. Cytokine levels of IL-8, MIP-1β, IL-6, IFN-γ, GM-CSF, TNF, IL-2, IL-4, MCP-1, and IL-10 were decreased significantly with caffeine treatment. Upstream regulator analysis suggests that caffeine inhibits STAT1 signaling, which was confirmed by showing reduced phosphorylated STAT1 after caffeine treatment. Further studies exploring disease-modulating potential of caffeine in autoimmune diseases and further exploring the mechanisms involved are warranted. Copyright © 2018 Elsevier Inc. All rights reserved.

TGF-β prevents phosphate-induced osteogenesis through inhibition of BMP and Wnt/β-catenin pathways.

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Fátima Guerrero

Full Text Available BACKGROUND: Transforming growth factor-β (TGF-β is a key cytokine during differentiation of mesenchymal stem cells (MSC into vascular smooth muscle cells (VSMC. High phosphate induces a phenotypic transformation of vascular smooth muscle cells (VSMC into osteogenic-like cells. This study was aimed to evaluate signaling pathways involved during VSMC differentiation of MSC in presence or not of high phosphate. RESULTS: Our results showed that TGF-β induced nuclear translocation of Smad3 as well as the expression of vascular smooth muscle markers, such as smooth muscle alpha actin, SM22α, myocardin, and smooth muscle-myosin heavy chain. The addition of high phosphate to MSC promoted nuclear translocation of Smad1/5/8 and the activation of canonical Wnt/β-catenin in addition to an increase in BMP-2 expression, calcium deposition and alkaline phosphatase activity. The administration of TGF-β to MSC treated with high phosphate abolished all these effects by inhibiting canonical Wnt, BMP and TGF-β pathways. A similar outcome was observed in high phosphate-treated cells after the inhibition of canonical Wnt signaling with Dkk-1. Conversely, addition of both Wnt/β-catenin activators CHIR98014 and lithium chloride enhanced the effect of high phosphate on BMP-2, calcium deposition and alkaline phosphatase activity. CONCLUSIONS: Full VSMC differentiation induced by TGF-β may not be achieved when extracellular phosphate levels are high. Moreover, TGF-β prevents high phosphate-induced osteogenesis by decreasing the nuclear translocation of Smad 1/5/8 and avoiding the activation of Wnt/β-catenin pathway.

The inhibition of the kynurenine pathway prevents behavioral disturbances and oxidative stress in the brain of adult rats subjected to an animal model of schizophrenia.

Science.gov (United States)

Réus, Gislaine Z; Becker, Indianara R T; Scaini, Giselli; Petronilho, Fabricia; Oses, Jean P; Kaddurah-Daouk, Rima; Ceretta, Luciane B; Zugno, Alexandra I; Dal-Pizzol, Felipe; Quevedo, João; Barichello, Tatiana

2018-02-02

Evidence has shown that the kynurenine pathway (KP) plays a role in the onset of oxidative stress and also in the pathophysiology of schizophrenia. The aim of this study was to use a pharmacological animal model of schizophrenia induced by ketamine to investigate if KP inhibitors could protect the brains of Wistar rats against oxidative stress and behavioral changes. Ketamine, injected at the dose of 25mg/kg, increased spontaneous locomotor activity. However, the inhibitors of tryptophan 2,3-dioxygenase (TDO), indoleamine 2,3-dioxygenase (IDO) and kynurenine-3-monooxygenase (KMO) were able to reverse these changes. In addition, the IDO inhibitor prevented lipid peroxidation, and decreased the levels of protein carbonyl in the prefrontal cortex (PFC), hippocampus and striatum. It also increased the activity of superoxide dismutase (SOD) in the hippocampus, as well as increasing the levels of catalase activity in the PFC and hippocampus. The TDO inhibitor prevented lipid damage in the striatum and reduced the levels of protein carbonyl in the hippocampus and striatum. Also, the TDO inhibitor increased the levels of SOD activity in the striatum and CAT activity in the hippocampus of ketamine-induced pro-oxidant effects. Lipid damage was not reversed by the KMO inhibitor. The KMO inhibitor increased the levels of SOD activity in the hippocampus, and reduced the levels of protein carbonyl while elevating the levels of CAT activity in the striatum of rats that had been injected with ketamine. Our findings revealed that the KP pathway could be a potential mechanism by which a schizophrenia animal model induced by ketamine could cause interference by producing behavioral disturbance and inducing oxidative stress in the brain, suggesting that the inhibition of the KP pathway could be a potential target in treating schizophrenia. Copyright © 2017 Elsevier Inc. All rights reserved.

Human studies of prepulse inhibition of startle: normal subjects, patient groups, and pharmacological studies.

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Braff, D L; Geyer, M A; Swerdlow, N R

2001-07-01

Since the mid-1970s, cross-species translational studies of prepulse inhibition (PPI) have increased at an astounding pace as the value of this neurobiologically informative measure has been optimized. PPI occurs when a relatively weak sensory event (the prepulse) is presented 30-500 ms before a strong startle-inducing stimulus, and reduces the magnitude of the startle response. In humans, PPI occurs in a robust, predictable manner when the prepulse and startling stimuli occur in either the same or different modalities (acoustic, visual, or cutaneous). This review covers three areas of interest in human PPI studies. First, we review the normal influences on PPI related to the underlying construct of sensori- (prepulse) motor (startle reflex) gating. Second, we review PPI studies in psychopathological disorders that form a family of gating disorders. Third, we review the relatively limited but interesting and rapidly expanding literature on pharmacological influences on PPI in humans. All studies identified by a computerized literature search that addressed the three topics of this review were compiled and evaluated. The principal studies were summarized in appropriate tables. The major influences on PPI as a measure of sensorimotor gating can be grouped into 11 domains. Most of these domains are similar across species, supporting the value of PPI studies in translational comparisons across species. The most prominent literature describing deficits in PPI in psychiatrically defined groups features schizophrenia-spectrum patients and their clinically unaffected relatives. These findings support the use of PPI as an endophenotype in genetic studies. Additional groups of psychopathologically disordered patients with neuropathology involving cortico-striato-pallido-pontine circuits exhibit poor gating of motor, sensory, or cognitive information and corresponding PPI deficits. These groups include patients with obsessive compulsive disorder, Tourette's syndrome

The Crc global regulator inhibits the Pseudomonas putida pWW0 toluene/xylene assimilation pathway by repressing the translation of regulatory and structural genes.

Science.gov (United States)

Moreno, Renata; Fonseca, Pilar; Rojo, Fernando

2010-08-06

In Pseudomonas putida, the expression of the pWW0 plasmid genes for the toluene/xylene assimilation pathway (the TOL pathway) is subject to complex regulation in response to environmental and physiological signals. This includes strong inhibition via catabolite repression, elicited by the carbon sources that the cells prefer to hydrocarbons. The Crc protein, a global regulator that controls carbon flow in pseudomonads, has an important role in this inhibition. Crc is a translational repressor that regulates the TOL genes, but how it does this has remained unknown. This study reports that Crc binds to sites located at the translation initiation regions of the mRNAs coding for XylR and XylS, two specific transcription activators of the TOL genes. Unexpectedly, eight additional Crc binding sites were found overlapping the translation initiation sites of genes coding for several enzymes of the pathway, all encoded within two polycistronic mRNAs. Evidence is provided supporting the idea that these sites are functional. This implies that Crc can differentially modulate the expression of particular genes within polycistronic mRNAs. It is proposed that Crc controls TOL genes in two ways. First, Crc inhibits the translation of the XylR and XylS regulators, thereby reducing the transcription of all TOL pathway genes. Second, Crc inhibits the translation of specific structural genes of the pathway, acting mainly on proteins involved in the first steps of toluene assimilation. This ensures a rapid inhibitory response that reduces the expression of the toluene/xylene degradation proteins when preferred carbon sources become available.

DMT efficiently inhibits hepatic gluconeogenesis by regulating the Gαq signaling pathway.

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Zhou, Ting-Ting; Ma, Fei; Shi, Xiao-Fan; Xu, Xin; Du, Te; Guo, Xiao-Dan; Wang, Gai-Hong; Yu, Liang; Rukachaisirikul, Vatcharin; Hu, Li-Hong; Chen, Jing; Shen, Xu

2017-08-01

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease with complicated pathogenesis and targeting gluconeogenesis inhibition is a promising strategy for anti-diabetic drug discovery. G protein-coupled receptors (GPCRs) are classified as distinct families by heterotrimeric G proteins, primarily including Gαs, Gαi and Gαq. Gαs-coupled GPCRs function potently in the regulation of hepatic gluconeogenesis by activating cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway and Gαi-coupled GPCRs exhibit inhibitory effect on adenylyl cyclase and reduce intracellular cAMP level. However, little is known about the regulation of Gαq-coupled GPCRs in hepatic gluconeogenesis. Here, small-molecule 2-(2,4-dimethoxy-3-methylphenyl)-7-(thiophen-2-yl)-9-(trifluoromethyl)-2,3-dihydropyrido[3',2':4,5]thieno[3,2-d]pyrimidin-4( 1H )-one (DMT) was determined to suppress hepatic glucose production and reduce mRNA levels of gluconeogenic genes. Treatment of DMT in db/db mice decreased fasting blood glucose and hemoglobin A1C (HbA1c) levels, while improved glucose tolerance and pyruvate tolerance. Mechanism study demonstrated that DMT-inhibited gluconeogenesis by regulating the Gαq/phospholipase C (PLC)/inositol-1,4,5-triphosphate receptor (IP3R)-mediated calcium (Ca 2+ )/calmodulin (CaM)/phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (AKT)/forkhead box protein O1 (FOXO1) signaling pathway. To our knowledge, DMT might be the first reported small molecule able to suppress hepatic gluconeogenesis by regulating Gαq signaling, and our current work has also highlighted the potential of DMT in the treatment of T2DM. © 2017 Society for Endocrinology.

Shenqiwan Ameliorates Renal Fibrosis in Rats by Inhibiting TGF-β1/Smads Signaling Pathway

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Hongshu Chen

2017-01-01

Full Text Available Epithelial-mesenchymal transition (EMT refers to the transition of epithelial cells into mesenchymal cells. Emerging evidence suggests that EMT is a key point in renal interstitial fibrosis (RIF. Traditional Chinese Medicine Shenqiwan (SQW is widely used in clinical treatment of chronic kidney disease, but the underlying mechanism remains unclear. The purpose of this study is to investigate the effect of SQW on renal fibrosis and its association with TGF-β1/Smads signaling pathway. A rat model of adenine (150 mg/kg was established and intragastrically treated with various concentrations of SQW at dose of 1.5 g/kg, 3 g/kg, and 6 g/kg. Control group and model group were given the same volume of saline. Meanwhile, the positive control group was treated with Enalapril (4 mg/kg. Animals were sacrificed on 21st day after administration. The results showed that SQW could significantly relieve renal pathological damage caused by adenine, increase gene and protein expression of E-cadherin, and decrease the expression of Vimentin in kidney samples. In addition, SQW efficiently inhibited the mRNA and protein expression of p-Smad2/3 by upregulating Smad7. These results suggest that SQW could slow down the progression of renal fibrosis, possibly by inhibiting TGF-β1/Smads signaling pathway.

Salinomycin, a polyether ionophoric antibiotic, inhibits adipogenesis

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Szkudlarek-Mikho, Maria; Saunders, Rudel A. [Department of Medicine, Biochemistry and Cancer Biology, Center for Diabetes and Endocrine Research, College of Medicine, University of Toledo, Toledo, OH 43614 (United States); Yap, Sook Fan [Faculty of Medicine and Health Sciences, Department of Pre-Clinical Sciences, University of Tunku Abdul Rahman (Malaysia); Ngeow, Yun Fong [Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603 (Malaysia); Chin, Khew-Voon, E-mail: khew-voon.chin@utoledo.edu [Department of Medicine, Biochemistry and Cancer Biology, Center for Diabetes and Endocrine Research, College of Medicine, University of Toledo, Toledo, OH 43614 (United States)

2012-11-30

Highlights: Black-Right-Pointing-Pointer Salinomycin inhibits preadipocyte differentiation into adipocytes. Black-Right-Pointing-Pointer Salinomycin inhibits transcriptional regulation of adipogenesis. Black-Right-Pointing-Pointer Pharmacological effects of salinomycin suggest toxicity in cancer therapy. -- Abstract: The polyether ionophoric antibiotics including monensin, salinomycin, and narasin, are widely used in veterinary medicine and as food additives and growth promoters in animal husbandry including poultry farming. Their effects on human health, however, are not fully understood. Recent studies showed that salinomycin is a cancer stem cell inhibitor. Since poultry consumption has risen sharply in the last three decades, we asked whether the consumption of meat tainted with growth promoting antibiotics might have effects on adipose cells. We showed in this report that the ionophoric antibiotics inhibit the differentiation of preadipocytes into adipocytes. The block of differentiation is not due to the induction of apoptosis nor the inhibition of cell proliferation. In addition, salinomycin also suppresses the transcriptional activity of the CCAAT/enhancer binding proteins and the peroxisome proliferator-activated receptor {gamma}. These results suggest that the ionophoric antibiotics can be exploited as novel anti-obesity therapeutics and as pharmacological probes for the study of adipose biology. Further, the pharmacological effects of salinomycin could be a harbinger of its toxicity on the adipose tissue and other susceptible target cells in cancer therapy.

Kushenin induces the apoptosis of HCV-infected cells by blocking the PI3K-Akt-mTOR pathway via inhibiting NS5A

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Zhou, Yi; Chen, Na; Liu, Xiaojing; Lin, Shumei [Department of Infectious Diseases, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi 710061 (China); Luo, Wenjuan, E-mail: wenjuanluoxa@163.com [School of Pharmacy, Xi’an Jiaotong University, Xi’an, Shaanxi 710061 (China); Liu, Min, E-mail: minliusx@163.com [Department of Infectious Diseases, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi 710061 (China)

2016-07-01

With the increased burden induced by HCV, there is an urgent need to develop better-tolerated agents with good safety. In this study, we evaluated the anti-HCV capability of kushenin, as well as the possible mechanism to Huh7.5-HCV cells. The results demonstrated that kushenin significantly inhibited the HCV-RNA level. Similarly, the expression of HCV-specific protein NS5A was also decreased. Molecular docking results displayed that kushenin bonded well to the active pockets of HCV NS5A, further confirming the effects of kushenin on HCV replication. Coimmunoprecipitation assay determined that kushenin suppressed the interaction between PI3K and NS5A in HCV-replicon cells. Furthermore, kushenin exerted an obviously induced function on HCV-replicon cells apoptosis by inhibiting PI3K-Akt-mTOR pathway, which could be ameliorated by the specific activator IGF-1 addition. Taken together, kushenin possesses the ability to inhibit HCV replication, and contributes to the increased apoptosis of HCV-infected cells by blocking the PI3K-Akt-mTOR pathway via inhibiting NS5A. Our results provide important evidence for a better understanding of the pathogenesis of HCV infection, and suggest that kushenin has the potential to treat HCV disease. - Highlights: • Kushenin inhibits HCV replication. • Kushenin bonds directly to NS5A protein. • Kushenin induces the apoptosis of HCV-infected cells. • kushenin suppresses the interaction between PI3K and NS5A. • Kushenin inhibits PI3K-Akt-mTOR pathway.

Kushenin induces the apoptosis of HCV-infected cells by blocking the PI3K-Akt-mTOR pathway via inhibiting NS5A

International Nuclear Information System (INIS)

Zhou, Yi; Chen, Na; Liu, Xiaojing; Lin, Shumei; Luo, Wenjuan; Liu, Min

2016-01-01

With the increased burden induced by HCV, there is an urgent need to develop better-tolerated agents with good safety. In this study, we evaluated the anti-HCV capability of kushenin, as well as the possible mechanism to Huh7.5-HCV cells. The results demonstrated that kushenin significantly inhibited the HCV-RNA level. Similarly, the expression of HCV-specific protein NS5A was also decreased. Molecular docking results displayed that kushenin bonded well to the active pockets of HCV NS5A, further confirming the effects of kushenin on HCV replication. Coimmunoprecipitation assay determined that kushenin suppressed the interaction between PI3K and NS5A in HCV-replicon cells. Furthermore, kushenin exerted an obviously induced function on HCV-replicon cells apoptosis by inhibiting PI3K-Akt-mTOR pathway, which could be ameliorated by the specific activator IGF-1 addition. Taken together, kushenin possesses the ability to inhibit HCV replication, and contributes to the increased apoptosis of HCV-infected cells by blocking the PI3K-Akt-mTOR pathway via inhibiting NS5A. Our results provide important evidence for a better understanding of the pathogenesis of HCV infection, and suggest that kushenin has the potential to treat HCV disease. - Highlights: • Kushenin inhibits HCV replication. • Kushenin bonds directly to NS5A protein. • Kushenin induces the apoptosis of HCV-infected cells. • kushenin suppresses the interaction between PI3K and NS5A. • Kushenin inhibits PI3K-Akt-mTOR pathway.

Pharmacological or genetic orexin 1 receptor inhibition attenuates MK-801 induced glutamate release in mouse cortex

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Leah eAluisio

2014-05-01

Full Text Available The orexin/hypocretin neuropeptides are produced by a cluster of neurons within the lateral posterior hypothalamus and participate in neuronal regulation by activating their receptors (OX1 and OX2 receptors. The orexin system projects widely through the brain and functions as an interface between multiple regulatory systems including wakefulness, energy balance, stress, reward and emotion. Recent studies have demonstrated that orexins and glutamate interact at the synaptic level and that orexins facilitate glutamate actions. We tested the hypothesis that orexins modulate glutamate signaling via OX1 receptors by monitoring levels of glutamate in frontal cortex of freely moving mice using enzyme coated biosensors under inhibited OX1 receptor conditions. MK-801, an NMDA receptor antagonist, was administered subcutaneously (0.178 mg/kg to indirectly disinhibit pyramidal neurons and therefore increase cortical glutamate release. In wild-type mice, pretreatment with the OX1 receptor antagonist GSK-1059865 (10 mg/kg S.C. which had no effect by itself, significantly attenuated the cortical glutamate release elicited by MK-801. OX1 receptor knockout mice had a blunted glutamate release response to MK-801 and exhibited about half of the glutamate release observed in wild-type mice in agreement with the data obtained with transient blockade of OX1 receptors. These results indicate that pharmacological (transient or genetic (permanent inhibition of the OX1 receptor similarly interfere with glutamatergic function in the cortex. Selectively targeting the OX1 receptor with an antagonist may normalize hyperglutamatergic states and thus may represent a novel therapeutic strategy for the treatment of various psychiatric disorders associated with hyperactive states.

Targeting Homologous Recombination by Pharmacological Inhibitors Enhances the Killing Response of Glioblastoma Cells Treated with Alkylating Drugs.

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Berte, Nancy; Piée-Staffa, Andrea; Piecha, Nadine; Wang, Mengwan; Borgmann, Kerstin; Kaina, Bernd; Nikolova, Teodora

2016-11-01

Malignant gliomas exhibit a high level of intrinsic and acquired drug resistance and have a dismal prognosis. First- and second-line therapeutics for glioblastomas are alkylating agents, including the chloroethylating nitrosoureas (CNU) lomustine, nimustine, fotemustine, and carmustine. These agents target the tumor DNA, forming O 6 -chloroethylguanine adducts and secondary DNA interstrand cross-links (ICL). These cross-links are supposed to be converted into DNA double-strand breaks, which trigger cell death pathways. Here, we show that lomustine (CCNU) with moderately toxic doses induces ICLs in glioblastoma cells, inhibits DNA replication fork movement, and provokes the formation of DSBs and chromosomal aberrations. Since homologous recombination (HR) is involved in the repair of DSBs formed in response to CNUs, we elucidated whether pharmacologic inhibitors of HR might have impact on these endpoints and enhance the killing effect. We show that the Rad51 inhibitors RI-1 and B02 greatly ameliorate DSBs, chromosomal changes, and the level of apoptosis and necrosis. We also show that an inhibitor of MRE11, mirin, which blocks the formation of the MRN complex and thus the recognition of DSBs, has a sensitizing effect on these endpoints as well. In a glioma xenograft model, the Rad51 inhibitor RI-1 clearly enhanced the effect of CCNU on tumor growth. The data suggest that pharmacologic inhibition of HR, for example by RI-1, is a reasonable strategy for enhancing the anticancer effect of CNUs. Mol Cancer Ther; 15(11); 2665-78. ©2016 AACR. ©2016 American Association for Cancer Research.

PMI: a ΔΨm independent pharmacological regulator of mitophagy.

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East, Daniel A; Fagiani, Francesca; Crosby, James; Georgakopoulos, Nikolaos D; Bertrand, Hélène; Schaap, Marjolein; Fowkes, Adrian; Wells, Geoff; Campanella, Michelangelo

2014-11-20

Mitophagy is central to mitochondrial and cellular homeostasis and operates via the PINK1/Parkin pathway targeting mitochondria devoid of membrane potential (ΔΨm) to autophagosomes. Although mitophagy is recognized as a fundamental cellular process, selective pharmacologic modulators of mitophagy are almost nonexistent. We developed a compound that increases the expression and signaling of the autophagic adaptor molecule P62/SQSTM1 and forces mitochondria into autophagy. The compound, P62-mediated mitophagy inducer (PMI), activates mitophagy without recruiting Parkin or collapsing ΔΨm and retains activity in cells devoid of a fully functional PINK1/Parkin pathway. PMI drives mitochondria to a process of quality control without compromising the bio-energetic competence of the whole network while exposing just those organelles to be recycled. Thus, PMI circumvents the toxicity and some of the nonspecific effects associated with the abrupt dissipation of ΔΨm by ionophores routinely used to induce mitophagy and represents a prototype pharmacological tool to investigate the molecular mechanisms of mitophagy.

Dual Inhibition of PI3K/AKT and MEK/ERK Pathways Induces Synergistic Antitumor Effects in Diffuse Intrinsic Pontine Glioma Cells

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Y. Linda Wu

2017-04-01

Full Text Available Diffuse intrinsic pontine glioma (DIPG is a devastating disease with an extremely poor prognosis. Recent studies have shown that platelet-derived growth factor receptor (PDGFR and its downstream effector pathway, PI3K/AKT/mTOR, are frequently amplified in DIPG, and potential therapies targeting this pathway have emerged. However, the addition of targeted single agents has not been found to improve clinical outcomes in DIPG, and targeting this pathway alone has produced insufficient clinical responses in multiple malignancies investigated, including lung, endometrial, and bladder cancers. Acquired resistance also seems inevitable. Activation of the Ras/Raf/MEK/ERK pathway, which shares many nodes of cross talk with the PI3K/AKT pathway, has been implicated in the development of resistance. In the present study, perifosine, a PI3K/AKT pathway inhibitor, and trametinib, a MEK inhibitor, were combined, and their therapeutic efficacy on DIPG cells was assessed. Growth delay assays were performed with each drug individually or in combination. Here, we show that dual inhibition of PI3K/AKT and MEK/ERK pathways synergistically reduced cell viability. We also reveal that trametinib induced AKT phosphorylation in DIPG cells that could not be effectively attenuated by the addition of perifosine, likely due to the activation of other compensatory mechanisms. The synergistic reduction in cell viability was through the pronounced induction of apoptosis, with some effect from cell cycle arrest. We conclude that the concurrent inhibition of the PI3K/AKT and MEK/ERK pathways may be a potential therapeutic strategy for DIPG.

FANCD2 re-expression is associated with glioma grade and chemical inhibition of the Fanconi Anaemia pathway sensitises gliomas to chemotherapeutic agents

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Patil, Abhijit A.; Sayal, Parag; Depondt, Marie-Lise; Beveridge, Ryan D.; Roylance, Anthony; Kriplani, Deepti H.; Myers, Katie N.; Cox, Angela; Jellinek, David; Fernando, Malee; Carroll, Thomas A.; Collis, Spencer J.

2014-01-01

Brain tumours kill more children and adults under 40 than any other cancer. Around half of primary brain tumours are glioblastoma multiforme (GBMs) where treatment remains a significant challenge. GBM survival rates have improved little over the last 40 years, thus highlighting an unmet need for the identification/development of novel therapeutic targets and agents to improve GBM treatment. Using archived and fresh glioma tissue, we show that in contrast to normal brain or benign schwannomas GBMs exhibit re-expression of FANCD2, a key protein of the Fanconi Anaemia (FA) DNA repair pathway, and possess an active FA pathway. Importantly, FANCD2 expression levels are strongly associated with tumour grade, revealing a potential exploitable therapeutic window to allow inhibition of the FA pathway in tumour cells, whilst sparing normal brain tissue. Using several small molecule inhibitors of the FA pathway in combination with isogenic FA-proficient/deficient glioma cell lines as well as primary GBM cultures, we demonstrate that inhibition of the FA pathway sensitises gliomas to the chemotherapeutic agents Temozolomide and Carmustine. Our findings therefore provide a strong rationale for the development of novel and potent inhibitors of the FA pathway to improve the treatment of GBMs, which may ultimately impact on patient outcome. PMID:25071006

Inhibition of dihydrotestosterone synthesis in prostate cancer by combined frontdoor and backdoor pathway blockade

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Fiandalo, Michael V.; Stocking, John J.; Pop, Elena A.; Wilton, John H.; Mantione, Krystin M.; Li, Yun; Attwood, Kristopher M.; Azabdaftari, Gissou; Wu, Yue; Watt, David S.; Wilson, Elizabeth M.; Mohler, James L.

2018-01-01

Androgen deprivation therapy (ADT) is palliative and prostate cancer (CaP) recurs as lethal castration-recurrent/resistant CaP (CRPC). One mechanism that provides CaP resistance to ADT is primary backdoor androgen metabolism, which uses up to four 3α-oxidoreductases to convert 5α-androstane-3α,17β-diol (DIOL) to dihydrotestosterone (DHT). The goal was to determine whether inhibition of 3α-oxidoreductase activity decreased conversion of DIOL to DHT. Protein sequence analysis showed that the four 3α-oxidoreductases have identical catalytic amino acid residues. Mass spectrometry data showed combined treatment using catalytically inactive 3α-oxidoreductase mutants and the 5α-reductase inhibitor, dutasteride, decreased DHT levels in CaP cells better than dutasteride alone. Combined blockade of frontdoor and backdoor pathways of DHT synthesis provides a therapeutic strategy to inhibit CRPC development and growth. PMID:29541409

Efficient Use of Exogenous Isoprenols for Protein Isoprenylation by MDA-MB-231 Cells Is Regulated Independently of the Mevalonate Pathway*

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Onono, Fredrick; Subramanian, Thangaiah; Sunkara, Manjula; Subramanian, Karunai Leela; Spielmann, H. Peter; Morris, Andrew J.

2013-01-01

Mammalian cells can use exogenous isoprenols to generate isoprenoid diphosphate substrates for protein isoprenylation, but the mechanism, efficiency, and biological importance of this process are not known. We developed mass spectrometry-based methods using chemical probes and newly synthesized stable isotope-labeled tracers to quantitate incorporation of exogenously provided farnesol, geranylgeraniol, and unnatural analogs of these isoprenols containing an aniline group into isoprenoid diphosphates and protein isoprenylcysteines by cultured human cancer cell lines. We found that at exogenous isoprenol concentrations >10 μm, this process can generate as much as 50% of the cellular isoprenoid diphosphate pool used for protein isoprenylation. Mutational activation of p53 in MDA-MB-231 breast cancer cells up-regulates the mevalonate pathway to promote tumor invasiveness. p53 silencing or pharmacological inhibition of HMG-CoA reductase in these cells decreases protein isoprenylation from endogenously synthesized isoprenoids but enhances the use of exogenous isoprenols for this purpose, indicating that this latter process is regulated independently of the mevalonate pathway. Our observations suggest unique opportunities for design of cancer cell-directed therapies and may provide insights into mechanisms underlying pleiotropic therapeutic benefits and unwanted side effects of mevalonate pathway inhibition. PMID:23908355

Jolkinolide B inhibits glycolysis by downregulating hexokinase 2 expression through inactivating the Akt/mTOR pathway in non-small cell lung cancer cells.

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Gao, Xiang; Han, Han

2018-06-01

Jolkinolide B (JB), a bioactive compound isolated from herbal medicine, has been found to inhibit tumor growth by altering glycolysis. However, whether glycolysis is influenced by JB in non-small cell lung cancer (NSCLC) cells and the mechanism remain unknown. The aim of the present study was to evaluate the effect of JB on the glycolysis in NSCLC cells and the underlying molecular mechanism. The results showed that JB treatment inhibited cell viability of A549 and H1299 cells in a concentration-dependent manner. JB reduced the glucose consumption, lactate production, and HK2 expression. The expressions of p-Akt and p-mTOR were also decreased by JB treatment. Knockdown of HK2 reduced glucose consumption and lactate production. Inhibition of the Akt/mTOR pathway decreased HK2 expression and inhibited glycolysis. In conclusion, the results indicated that JB inhibits glycolysis by down-regulating HK2 expression through inactivating the Akt/mTOR pathway in NSCLC cells, suggesting that JB might be a potential therapeutic agent for the treatment of NSCLC. © 2018 Wiley Periodicals, Inc.

Targeting the NF-κB Pathway as a Combination Therapy for Advanced Thyroid Cancer.

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Nikita Pozdeyev

Full Text Available NF-κB signaling plays an important role in tumor cell proliferation, cell survival, angiogenesis, invasion, metastasis and drug/radiation resistance. Combination therapy involving NF-κB pathway inhibition is an attractive strategy for the treatment of advanced forms of thyroid cancer. This study was designed to test the efficacy of NF-κB pathway inhibition in combination with cytotoxic chemotherapy, using docetaxel and ionizing radiation in in vitro models of thyroid cancer. We found that while both docetaxel and ionizing radiation activated NF-κB signaling in thyroid cancer cells, there was no synergistic effect on cell proliferation and/or programmed cell death with either genetic (transduction of a dominant negative mutant form of IκBα or pharmacologic (proteasome inhibitor bortezomib and IKKβ inhibitor GO-Y030 inhibition of the NF-κB pathway in thyroid cancer cell lines BCPAP, 8505C, THJ16T and SW1736. Docetaxel plus bortezomib synergistically decreased in vitro invasion of 8505C cells, but not in the other cell lines. Screening of a panel of clinically relevant targeted therapies for synergy with genetic NF-κB inhibition in a proliferation/cytotoxicity assay identified the histone deacetylase (HDAC inhibitor suberoylanilide hydroxamic acid (SAHA as a potential candidate. However, the synergistic effect was confirmed only in the BCPAP cells. These results indicate that NF-κB inhibitors are unlikely to be beneficial as combination therapy with taxane cytotoxic chemotherapy, external radiation therapy or radioiodine therapy. There may be unique circumstances where NF-κB inhibitors may be considered in combination with docetaxel to reduce tumor invasion or in combination with HDAC inhibitors to reduce tumor growth, but this does not appear to be a combination therapy that could be broadly applied to patients with advanced thyroid cancer. Further research may identify which subsets of patients/tumors may respond to this therapeutic

Didymin Alleviates Hepatic Fibrosis Through Inhibiting ERK and PI3K/Akt Pathways via Regulation of Raf Kinase Inhibitor Protein

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Xing Lin

2016-12-01

Full Text Available Background: Didymin has been reported to have anti-cancer potential. However, the effect of didymin on liver fibrosis remains illdefined. Methods: Hepatic fibrosis was induced by CCl4 in rats. The effects of didymin on liver pathology and collagen accumulation were observed by hematoxylin-eosin and Masson's trichrome staining, respectively. Serum transaminases activities and collagen-related indicators levels were determined by commercially available kits. Moreover, the effects of didymin on hepatic stellate cell apoptosis and cell cycle were analyzed by flow cytometry. Mitochondrial membrane potential was detected by using rhodamine-123 dye. The expression of Raf kinase inhibitor protein (RKIP and the phosphorylation of the ERK/MAPK and PI3K/Akt pathways were assessed by Western blot. Results: Didymin significantly ameliorated chronic liver injury and collagen deposition. It strongly inhibited hepatic stellate cells proliferation, induced apoptosis and caused cell cycle arrest in G2/M phase. Moreover, didymin notably attenuated mitochondrial membrane potential, accompanied by release of cytochrome C. Didymin significantly inhibited the ERK/MAPK and PI3K/Akt pathways. The effects of didymin on the collagen accumulation in rats and on the biological behaviors of hepatic stellate cells were largely abolished by the specific RKIP inhibitor locostatin. Conclusion: Didymin alleviates hepatic fibrosis by inhibiting ERK/MAPK and PI3K/Akt pathways via regulation of RKIP expression.

miR-15a/miR-16 cluster inhibits invasion of prostate cancer cells by suppressing TGF-β signaling pathway.

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Jin, Wei; Chen, Fangjie; Wang, Kefeng; Song, Yan; Fei, Xiang; Wu, Bin

2018-05-23

To determine whether and how miR15a/16 regulate TGF-β signaling pathways during the progression of prostate cancer. We used bioinformatics prediction, reporter gene assay, real-time PCR, Matrigel invasion assay and Western blot to dissect the molecular mechanism of how miR-15a/miR-16 may cause metastasis in prostate tumor. MiR-15a/16 targeted and inhibited the expression of endogenous Smad3 and ACVR2A proteins. The overexpression of miR15a/16 down-regulated p-smad3 expression, affected the expression of both MMP2 and E-cadherin, and down-regulated the expression of the EMT-mediated factors Snail and Twist in LNCaP prostate cancer cells. The overexpression of miR15a/16 decreased the invasion of LNCaP cells. MiR-15a/miR-16 cluster could reverse the invasion of activin A-mediated prostate cancer cells. After the inhibition of the activin/smad signaling pathway, the inhibitory effect of invasion in prostate cancer cells by miR-15a/miR-16 cluster disappeared. Our data indicated that miR15a/16 inhibited the components of TGF-β signaling pathways in LNCaP cell line, which might relate to the progression and metastasis of prostate cancer. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Curcumin Attenuated Bupivacaine-Induced Neurotoxicity in SH-SY5Y Cells Via Activation of the Akt Signaling Pathway.

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Fan, You-Ling; Li, Heng-Chang; Zhao, Wei; Peng, Hui-Hua; Huang, Fang; Jiang, Wei-Hang; Xu, Shi-Yuan

2016-09-01

Bupivacaine is widely used for regional anesthesia, spinal anesthesia, and pain management. However, bupivacaine could cause neuronal injury. Curcumin, a low molecular weight polyphenol, has a variety of bioactivities and may exert neuroprotective effects against damage induced by some stimuli. In the present study, we tested whether curcumin could attenuate bupivacaine-induced neurotoxicity in SH-SY5Y cells. Cell injury was evaluated by examining cell viability, mitochondrial damage and apoptosis. We also investigated the levels of activation of the Akt signaling pathway and the effect of Akt inhibition by triciribine on cell injury following bupivacaine and curcumin treatment. Our findings showed that the bupivacaine treatment could induce neurotoxicity. Pretreatment of the SH-SY5Y cells with curcumin significantly attenuated bupivacaine-induced neurotoxicity. Interestingly, the curcumin treatment increased the levels of Akt phosphorylation. More significantly, the pharmacological inhibition of Akt abolished the cytoprotective effect of curcumin against bupivacaine-induced cell injury. Our data suggest that pretreating SH-SY5Y cells with curcumin provides a protective effect on bupivacaine-induced neuronal injury via activation of the Akt signaling pathway.

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

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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.

The Hippo pathway mediates inhibition of vascular smooth muscle cell proliferation by cAMP.

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Kimura, Tomomi E; Duggirala, Aparna; Smith, Madeleine C; White, Stephen; Sala-Newby, Graciela B; Newby, Andrew C; Bond, Mark

2016-01-01

Inhibition of vascular smooth muscle cell (VSMC) proliferation by intracellular cAMP prevents excessive neointima formation and hence angioplasty restenosis and vein-graft failure. These protective effects are mediated via actin-cytoskeleton remodelling and subsequent regulation of gene expression by mechanisms that are incompletely understood. Here we investigated the role of components of the growth-regulatory Hippo pathway, specifically the transcription factor TEAD and its co-factors YAP and TAZ in VSMC. Elevation of cAMP using forskolin, dibutyryl-cAMP or the physiological agonists, Cicaprost or adenosine, significantly increased phosphorylation and nuclear export YAP and TAZ and inhibited TEAD-luciferase report gene activity. Similar effects were obtained by inhibiting RhoA activity with C3-transferase, its downstream kinase, ROCK, with Y27632, or actin-polymerisation with Latrunculin-B. Conversely, expression of constitutively-active RhoA reversed the inhibitory effects of forskolin on TEAD-luciferase. Forskolin significantly inhibited the mRNA expression of the pro-mitogenic genes, CCN1, CTGF, c-MYC and TGFB2 and this was reversed by expression of constitutively-active YAP or TAZ phospho-mutants. Inhibition of YAP and TAZ function with RNAi or Verteporfin significantly reduced VSMC proliferation. Furthermore, the anti-mitogenic effects of forskolin were reversed by overexpression of constitutively-active YAP or TAZ. Taken together, these data demonstrate that cAMP-induced actin-cytoskeleton remodelling inhibits YAP/TAZ-TEAD dependent expression of pro-mitogenic genes in VSMC. This mechanism contributes novel insight into the anti-mitogenic effects of cAMP in VSMC and suggests a new target for intervention. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Inhibition of MHC-I by Brucella abortus is an early event during infection and involves EGFR pathway.

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Velásquez, Lis N; Milillo, M Ayelén; Delpino, M Victoria; Trotta, Aldana; Mercogliano, M Florencia; Pozner, Roberto G; Schillaci, Roxana; Elizalde, Patricia V; Giambartolomei, Guillermo H; Barrionuevo, Paula

2017-04-01

Brucella abortus is able to persist inside the host despite the development of potent CD8 + T-cell responses. We have recently reported the ability of B. abortus to inhibit the interferon-γ-induced major histocompatibility complex (MHC)-I cell surface expression on human monocytes. This phenomenon was due to the B. abortus-mediated retention of MHC-I molecules within the Golgi apparatus and was dependent on bacterial viability. However, the implications of bacterial virulence or replicative capacity and the signaling pathways remained unknown. Here we demonstrated that the B. abortus mutant strains RB51 and virB10 - are able to inhibit MHC-I expression in the same manner as wild-type B. abortus, even though they are unable to persist inside human monocytes for a long period of time. Consistent with this, the phenomenon was triggered early in time and could be observed at 8 h postinfection. At 24 and 48 h, it was even stronger. Regarding the signaling pathway, targeting epidermal growth factor (EGF) receptor (EGFR), ErbB2 (HER2) or inhibition of tumor necrosis factor-α-converting enzyme, one of the enzymes which generates soluble EGF-like ligands, resulted in partial recovery of MHC-I surface expression. Moreover, recombinant EGF and transforming growth factor-α as well as the combination of both were also able to reproduce the B. abortus-induced MHC-I downmodulation. Finally, when infection was performed in the presence of an extracellular signal-regulated kinase 1/2 (Erk1/2) inhibitor, MHC-I surface expression was significantly recovered. Overall, these results describe how B. abortus evades CD8 + T-cell responses early during infection and exploits the EGFR-ERK signaling pathway to escape from the immune system and favor chronicity.

miR-449 overexpression inhibits papillary thyroid carcinoma cell growth by targeting RET kinase-β-catenin signaling pathway.

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Li, Zongyu; Huang, Xin; Xu, Jinkai; Su, Qinghua; Zhao, Jun; Ma, Jiancang

2016-10-01

Papillary thyroid carcinoma (PTC) is the most common thyroid cancer and represent approximately 80% of all thyroid cancers. The present study is aimed to investigate the role of microRNA (miR)-449 in the progression of PTC. Our results revealed that miR-449 was underexpressed in the collected PTC specimens compared with non-cancerous PTC tissues. Overexpression of miR-449 induced a cell cycle arrest at G0/G1 phase and inhibited PTC cell growth in vitro. Further studies revealed that RET proto-oncogene (RET) is a novel miR-449 target, due to miR-449 bound directly to its 3'-untranslated region and miR-449 mimic reduced the protein expression of RET. Similar to the effects of miR-449 overexpression, RET downregulation inhibited cell growth, whereas RET overexpression reversed the inhibitive effect of miR-449 mimic. Furthermore, miR-449 overexpression inhibited the nuclear translocation of β-catenin and reduced the expression of several downstream genes, including c-Myc, cyclin D1, T cell-specific transcription factor (TCF) and lymphoid enhancer-binding factor 1 (LEF-1), and inactivated the β-catenin pathway in TPC-1 cells. Moreover, overexpression of β-catenin prevented miR-449-reduced cell cycle arrest and cell viability. In xenograft animal experiments, miR-449 overexpression effectively suppressed the tumor growth of PTC. Taken together, our research indicated that miR-449 functions as an anti-oncogene by targeting RET, and that miR-449 overexpression inhibited the growth of PTC by inactivating the β-catenin pathway. Thus, miR-449 may serve as a potential therapeutic strategy for the treatment of PTC.

Tissue Factor Pathway Inhibitor: Multiple Anticoagulant Activities for a Single Protein.

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Mast, Alan E

2016-01-01

Tissue factor (TF) pathway inhibitor (TFPI) is an anticoagulant protein that inhibits early phases of the procoagulant response. Alternatively spliced isoforms of TFPI are differentially expressed by endothelial cells and human platelets and plasma. The TFPIβ isoform localizes to the endothelium surface where it is a potent inhibitor of TF-factor VIIa complexes that initiate blood coagulation. The TFPIα isoform is present in platelets. TFPIα contains a stretch of 9 amino acids nearly identical to those found in the B-domain of factor V that are well conserved in mammals. These amino acids provide exosite binding to activated factor V, which allows for TFPIα to inhibit prothrombinase during the initiation phase of blood coagulation. Endogenous inhibition at this point in the coagulation cascade was only recently recognized and has provided a biochemical rationale to explain the pathophysiological mechanisms underlying several clinical disorders. These include the east Texas bleeding disorder that is caused by production of an altered form of factor V with high affinity for TFPI and a paradoxical procoagulant effect of heparins. In addition, these findings have led to ideas for pharmacological targeting of TFPI that may reduce bleeding in hemophilia patients. © 2015 American Heart Association, Inc.

Saw Palmetto Extract Inhibits Metastasis and Antiangiogenesis through STAT3 Signal Pathway in Glioma Cell

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Ding, Hong; Shen, Jinglian; Yang, Yang; Che, Yuqin

2015-01-01

Signal transducer and activator of transcription factor 3 (STAT3) plays an important role in the proliferation and angiogenesis in human glioma. Previous research indicated that saw palmetto extract markedly inhibited the proliferation of human glioma cells through STAT3 signal pathway. But its effect on tumor metastasis and antiangiogenesis is not clear. This study is to further clear the impact of saw palmetto extract on glioma cell metastasis, antiangiogenesis, and its mechanism. TUNEL ass...

Pharmacologic inhibition of S1P attenuates ATF6 expression, causes ER stress and contributes to apoptotic cell death.

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Lebeau, Paul; Byun, Jae Hyun; Yousof, Tamana; Austin, Richard C

2018-04-22

Mammalian cells express unique transcription factors embedded in the endoplasmic reticulum (ER) membrane, such as the sterol regulatory element-binding proteins (SREBPs), that promote de novo lipogenesis. Upon their release from the ER, the SREBPs require proteolytic activation in the Golgi by site-1-protease (S1P). As such, inhibition of S1P, using compounds such as PF-429242 (PF), reduces cholesterol synthesis and may represent a new strategy for the management of dyslipidemia. In addition to the SREBPs, the unfolded protein response (UPR) transducer, known as the activating transcription factor 6 (ATF6), is another ER membrane-bound transcription factor that requires S1P-mediated activation. ATF6 regulates ER protein folding capacity by promoting the expression of ER chaperones such as the 78-kDa glucose-regulated protein (GRP78). ER-resident chaperones like GRP78 prevent and/or resolve ER polypeptide accumulation and subsequent ER stress-induced UPR activation by folding nascent polypeptides. Here we report that pharmacological inhibition of S1P reduced the expression of ATF6 and GRP78 and induced the activation of UPR transducers inositol-requiring enzyme-1α (IRE1α) and protein kinase RNA-like ER kinase (PERK). As a consequence, S1P inhibition also increased the susceptibility of cells to ER stress-induced cell death. Our findings suggest that S1P plays a crucial role in the regulation of ER folding capacity and also identifies a compensatory cross-talk between UPR transducers in order to maintain adequate ER chaperone expression and activity. Copyright © 2018. Published by Elsevier Inc.

p8 inhibits the growth of human pancreatic cancer cells and its expression is induced through pathways involved in growth inhibition and repressed by factors promoting cell growth

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Vasseur Sophie

2003-11-01

Full Text Available Abstract Background p8 is a stress-induced protein with multiple functions and biochemically related to the architectural factor HMG-I/Y. We analyzed the expression and function of p8 in pancreatic cancer-derived cells. Methods Expression of p8 was silenced in the human pancreatic cancer cell lines Panc-1 and BxPc-3 by infection with a retrovirus expressing p8 RNA in the antisense orientation. Cell growth was measured in control and p8-silenced cells. Influence on p8 expression of the induction of intracellular pathways promoting cellular growth or growth arrest was monitored. Results p8-silenced cells grew more rapidly than control cells transfected with the empty retrovirus. Activation of the Ras→Raf→MEK→ERK and JNK intracellular pathways down-regulated p8 expression. In addition, the MEK1/2 inhibitor U0126 and the JNK inhibitor SP600125 up-regulates expression of p8. Conversely, p38 or TGFβ-1 induced p8 expression whereas the specific p38 inhibitor SB203580 down-regulated p8 expression. Finally, TGFβ-1 induction was in part mediated through p38. Conclusions p8 inhibits the growth of human pancreatic cancer cells. p8 expression is induced through pathways involved in growth inhibition and repressed by factors that promote cell growth. These results suggest that p8 belongs to a pathway regulating the growth of pancreatic cancer cells.

Picropodophyllin inhibits the growth of Ewing's sarcoma cells through the insulin‑like growth factor‑1 receptor/Akt signaling pathway.

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Wu, Yong-Tao; Wang, Bao-Jun; Miao, Sheng-Wu; Gao, Jian-Jun

2015-11-01

Ewing's sarcoma (ES) is the second most common type of pediatric bone tumor, and is associated with a poor prognosis. Picropodophyllin (PPP), a novel selective inhibitor of insulin‑like growth factor‑1 receptor (IGF‑1R), is able to strongly inhibit various types of cancers. However, the effect of IGF‑1R on ES remains unclear. Following treatment with various concentrations of PPP for various times, cell viability was determined using an MTT assay. In addition, cell proliferation and apoptosis was investigated separately by bromodeoxyuridine staining and flow cytometry, respectively. The PPP‑associated signaling pathway was also investigated. The results of the present study suggested that PPP inhibited cell proliferation and viability of A673 and SK‑ES‑1 human Ewing's sarcoma cells in a dose- and time‑dependent manner. In addition, cell apoptosis rates were increased following treatment with PPP. Further investigation of the underlying mechanism revealed that PPP inhibited Akt phosphorylation. Fumonisin B1, an Akt‑specific activator, reversed the inhibitory effects of PPP on cell growth. Furthermore, the results suggested that PPP decreased the expression levels of IGF‑1R, a common activator of Akt signaling. PPP inhibited the growth of human Ewing's sarcoma cells by targeting the IGF‑1R/Akt signaling pathway. Therefore, PPP may prove useful in the development of an effective strategy for the treatment of Ewing's sarcoma.

Advanced glycation end product-induced astrocytic differentiation of cultured neurospheres through inhibition of Notch-Hes1 pathway-mediated neurogenesis.

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Guo, Yijing; Wang, Pin; Sun, Haixia; Cai, Rongrong; Xia, Wenqing; Wang, Shaohua

2013-12-23

This study aims to investigate the roles of the Notch-Hes1 pathway in the advanced glycation end product (AGE)-mediated differentiation of neural stem cells (NSCs). We prepared pLentiLox3.7 lentiviral vectors that express short hairpin RNA (shRNA) against Notch1 and transfected it into NSCs. Cell differentiation was analyzed under confocal laser-scanning microscopy. The percentage of neurons and astrocytes was quantified by normalizing the total number of TUJ1+ (Neuron-specific class III β-tubulin) and GFAP+ (Glial fibrillary acidic protein) cells to the total number of Hoechst 33342-labeled cell nuclei. The protein and gene expression of Notch-Hes1 pathway components was examined via western blot analysis and real-time PCR. After 1 week of incubation, we found that AGE-bovine serum albumin (BSA) (400 μg/mL) induced the astrocytic differentiation of cultured neurospheres and inhibited neuronal formation. The expression of Notch-Hes1 pathway components was upregulated in the cells in the AGE-BSA culture medium. Immunoblot analysis indicated that shRNA silencing of Notch1 expression in NSCs significantly increases neurogenesis and suppresses astrocytic differentiation in NSCs incubated with AGE-BSA. AGEs promote the astrocytic differentiation of cultured neurospheres by inhibiting neurogenesis through the Notch-Hes1 pathway, providing a potential therapeutic target for hyperglycemia-related cognitive deficits.

Pharmacological correction of long QT-linked mutations in KCNH2 (hERG) increases the trafficking of Kv11.1 channels stored in the transitional endoplasmic reticulum.

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Smith, Jennifer L; Reloj, Allison R; Nataraj, Parvathi S; Bartos, Daniel C; Schroder, Elizabeth A; Moss, Arthur J; Ohno, Seiko; Horie, Minoru; Anderson, Corey L; January, Craig T; Delisle, Brian P

2013-11-01

KCNH2 encodes Kv11.1 and underlies the rapidly activating delayed rectifier K(+) current (IKr) in the heart. Loss-of-function KCNH2 mutations cause the type 2 long QT syndrome (LQT2), and most LQT2-linked missense mutations inhibit the trafficking of Kv11.1 channels. Drugs that bind to Kv11.1 and block IKr (e.g., E-4031) can act as pharmacological chaperones to increase the trafficking and functional expression for most LQT2 channels (pharmacological correction). We previously showed that LQT2 channels are selectively stored in a microtubule-dependent compartment within the endoplasmic reticulum (ER). We tested the hypothesis that pharmacological correction promotes the trafficking of LQT2 channels stored in this compartment. Confocal analyses of cells expressing the trafficking-deficient LQT2 channel G601S showed that the microtubule-dependent ER compartment is the transitional ER. Experiments with E-4031 and the protein synthesis inhibitor cycloheximide suggested that pharmacological correction promotes the trafficking of G601S stored in this compartment. Treating cells in E-4031 or ranolazine (a drug that blocks IKr and has a short half-life) for 30 min was sufficient to cause pharmacological correction. Moreover, the increased functional expression of G601S persisted 4-5 h after drug washout. Coexpression studies with a dominant-negative form of Rab11B, a small GTPase that regulates Kv11.1 trafficking, prevented the pharmacological correction of G601S trafficking from the transitional ER. These data suggest that pharmacological correction quickly increases the trafficking of LQT2 channels stored in the transitional ER via a Rab11B-dependent pathway, and we conclude that the pharmacological chaperone activity of drugs like ranolazine might have therapeutic potential.

Magnolol inhibits migration of vascular smooth muscle cells via cytoskeletal remodeling pathway to attenuate neointima formation

International Nuclear Information System (INIS)

Karki, Rajendra; Kim, Seong-Bin; Kim, Dong-Wook

2013-01-01

Background: Increased proliferation and migration of vascular smooth muscle cells (VSMCs) contribute importantly to the formation of both atherosclerotic and restenotic lesions. The objective of this study was to investigate the effect of magnolol on VSMC migration. Methods: The proteolytic activity of matrix metalloproteinases (MMPs) in tumor necrosis factor alpha (TNF-α) stimulated VSMCs was performed by gelatin zymography. VSMC migration was assessed by wound healing and Boyden chamber methods. Collagen induced VSMC adhesion was determined by spectrofluorimeter and stress fibers formation was evaluated by fluorescence microscope. The expression of signaling molecules involved in stress fibers formation was determined by western blot. The phosphorylation of myosin light chain (MLC20) was determined by urea-glycerol polyacrylamide gel electrophoresis. Immunohistochemistry was performed to determine the expression of β1-integrin and collagen type I in the injured carotid arteries of rats on day 35 after vascular injury. Results: VSMC migration was strongly inhibited by magnolol without affecting MMPs expression. Also, magnolol inhibited β1-integrin expression, FAK phosphorylation and RhoA and Cdc42 activation to inhibit the collagen induced stress fibers formation. Moreover, magnolol inhibited the phosphorylation of MLC20. Our in vivo results showed that magnolol inhibited β1-integrin expression, collagen type I deposition and FAK phosphorylation in injured carotid arteries without affecting MMP-2 activity. Conclusions: Magnolol inhibited VSMC migration via inhibition of cytoskeletal remodeling pathway to attenuate neointima formation. General significance: This study provides a rationale for further evaluation of magnolol for the management of atherosclerosis and restenosis. - Highlights: • Magnolol strongly inhibited migration of VSMCs. • Magnolol inhibited stress fibers formation. • MLC20 phosphorylation was also inhibited by magnolol. • Anti

Magnolol inhibits migration of vascular smooth muscle cells via cytoskeletal remodeling pathway to attenuate neointima formation

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Karki, Rajendra [Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City (United States); Department of Oriental Medicine Resources, Mokpo National University (Korea, Republic of); Kim, Seong-Bin [Jeollanamdo Development Institute for Korean Traditional Medicine, Jangheung gun, Jeollanamdo (Korea, Republic of); Kim, Dong-Wook, E-mail: dbkim@mokpo.ac.kr [Department of Oriental Medicine Resources, Mokpo National University (Korea, Republic of)

2013-12-10

Background: Increased proliferation and migration of vascular smooth muscle cells (VSMCs) contribute importantly to the formation of both atherosclerotic and restenotic lesions. The objective of this study was to investigate the effect of magnolol on VSMC migration. Methods: The proteolytic activity of matrix metalloproteinases (MMPs) in tumor necrosis factor alpha (TNF-α) stimulated VSMCs was performed by gelatin zymography. VSMC migration was assessed by wound healing and Boyden chamber methods. Collagen induced VSMC adhesion was determined by spectrofluorimeter and stress fibers formation was evaluated by fluorescence microscope. The expression of signaling molecules involved in stress fibers formation was determined by western blot. The phosphorylation of myosin light chain (MLC20) was determined by urea-glycerol polyacrylamide gel electrophoresis. Immunohistochemistry was performed to determine the expression of β1-integrin and collagen type I in the injured carotid arteries of rats on day 35 after vascular injury. Results: VSMC migration was strongly inhibited by magnolol without affecting MMPs expression. Also, magnolol inhibited β1-integrin expression, FAK phosphorylation and RhoA and Cdc42 activation to inhibit the collagen induced stress fibers formation. Moreover, magnolol inhibited the phosphorylation of MLC20. Our in vivo results showed that magnolol inhibited β1-integrin expression, collagen type I deposition and FAK phosphorylation in injured carotid arteries without affecting MMP-2 activity. Conclusions: Magnolol inhibited VSMC migration via inhibition of cytoskeletal remodeling pathway to attenuate neointima formation. General significance: This study provides a rationale for further evaluation of magnolol for the management of atherosclerosis and restenosis. - Highlights: • Magnolol strongly inhibited migration of VSMCs. • Magnolol inhibited stress fibers formation. • MLC20 phosphorylation was also inhibited by magnolol. • Anti

Ethyl Pyruvate Ameliorates Hepatic Ischemia-Reperfusion Injury by Inhibiting Intrinsic Pathway of Apoptosis and Autophagy

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Miao Shen

2013-01-01

Full Text Available Background. Hepatic ischemia-reperfusion (I/R injury is a pivotal clinical problem occurring in many clinical conditions such as transplantation, trauma, and hepatic failure after hemorrhagic shock. Apoptosis and autophagy have been shown to contribute to cell death in hepatic I/R injury. Ethyl pyruvate, a stable and simple lipophilic ester, has been shown to have anti-inflammatory properties. In this study, the purpose is to explore both the effect of ethyl pyruvate on hepatic I/R injury and regulation of intrinsic pathway of apoptosis and autophagy. Methods. Three doses of ethyl pyruvate (20 mg/kg, 40 mg/kg, and 80 mg/kg were administered 1 h before a model of segmental (70% hepatic warm ischemia was established in Balb/c mice. All serum and liver tissues were obtained at three different time points (4 h, 8 h, and 16 h. Results. Alanine aminotransferase (ALT, aspartate aminotransferase (AST, and pathological features were significantly ameliorated by ethyl pyruvate (80 mg/kg. The expression of Bcl-2, Bax, Beclin-1, and LC3, which play an important role in the regulation of intrinsic pathway of apoptosis and autophagy, was also obviously decreased by ethyl pyruvate (80 mg/kg. Furthermore, ethyl pyruvate inhibited the HMGB1/TLR4/ NF-κb axis and the release of cytokines (TNF-α and IL-6. Conclusion. Our results showed that ethyl pyruvate might attenuate to hepatic I/R injury by inhibiting intrinsic pathway of apoptosis and autophagy, mediated partly through downregulation of HMGB1/TLR4/ NF-κb axis and the competitive interaction with Beclin-1 of HMGB1.

The ATM and ATR inhibitors CGK733 and caffeine suppress cyclin D1 levels and inhibit cell proliferation

International Nuclear Information System (INIS)

Alao, John P; Sunnerhagen, Per

2009-01-01

The ataxia telangiectasia mutated (ATM) and the ATM- related (ATR) kinases play a central role in facilitating the resistance of cancer cells to genotoxic treatment regimens. The components of the ATM and ATR regulated signaling pathways thus provide attractive pharmacological targets, since their inhibition enhances cellular sensitivity to chemo- and radiotherapy. Caffeine as well as more specific inhibitors of ATM (KU55933) or ATM and ATR (CGK733) have recently been shown to induce cell death in drug-induced senescent tumor cells. Addition of these agents to cancer cells previously rendered senescent by exposure to genotoxins suppressed the ATM mediated p21 expression required for the survival of these cells. The precise molecular pharmacology of these agents however, is not well characterized. Herein, we report that caffeine, CGK733, and to a lesser extent KU55933, inhibit the proliferation of otherwise untreated human cancer and non-transformed mouse fibroblast cell lines. Exposure of human cancer cell lines to caffeine and CGK733 was associated with a rapid decline in cyclin D1 protein levels and a reduction in the levels of both phosphorylated and total retinoblastoma protein (RB). Our studies suggest that observations based on the effects of these compounds on cell proliferation and survival must be interpreted with caution. The differential effects of caffeine/CGK733 and KU55933 on cyclin D1 protein levels suggest that these agents will exhibit dissimilar molecular pharmacological profiles

The pharmacological assay as a tool to medicinal plants domestication

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Montanari Jr., Ilio

2016-07-01

Full Text Available In Brazil studies with native medicinal plants are usually performed using non-domesticated plants and as a result the genetic variability of wild species could express different levels of active principles changing their therapeutic effect. Based on that, the aim of this study was to demonstrate that extract of different half- sib families Cordia verbenacea (DC, widely used as medicinal plant in Brazil, have different efficacy in the Total Growth Inhibition (TGI of 5 different human tumor cell lines. Data were statistically analyzed using ANOVA follow by Tuckey test and a heritability estimation of the plant families was performed. The results showed that TGI are different for each plant family according with each human tumor cell line. For instance, extracts obtained from families 3,11 and 12 were more effective to inhibit the U-251 and Ht-29 cell lines compared to the other families, while extracts obtained from the family 32 was more effective against thethe PC-3 line. The heritability coefficient indicated that plant population selection could promote a genetic improvement related to its active principle and their pharmacological effect and could provide the identification of the best families according to their pharmacological efficacy. In conclusion, this study suggests that the domestication of a wild medicinal plant should be better monitored by its pharmacological effect.

Inhibition of the thyroid hormone pathway in Xenopus laevis by 2-mercaptobenzothiazole

International Nuclear Information System (INIS)

Tietge, Joseph E.; Degitz, Sigmund J.; Haselman, Jonathan T.; Butterworth, Brian C.; Korte, Joseph J.; Kosian, Patricia A.; Lindberg-Livingston, Annelie J.

2013-01-01

Determining the effects of chemicals on the thyroid system is an important aspect of evaluating chemical safety from an endocrine disrupter perspective. Since there are numerous chemicals to test and limited resources, prioritizing chemicals for subsequent in vivo testing is critical. 2-Mercaptobenzothiazole (MBT), a high production volume chemical, was tested and shown to inhibit thyroid peroxidase (TPO) enzyme activity in vitro, a key enzyme necessary for the synthesis of thyroid hormone. To determine the thyroid disrupting activity of MBT in vivo, Xenopus laevis larvae were exposed using 7- and 21-day protocols. The 7-day protocol used 18–357 μg/L MBT concentrations and evaluated: metamorphic development, thyroid histology, circulating T4, circulating thyroid stimulating hormone, thyroidal sodium-iodide symporter gene expression, and thyroidal T4, T3, and related iodo-amino acids. The 21-day protocol used 23–435 μg/L MBT concentrations and evaluated metamorphic development and thyroid histology. Both protocols demonstrated that MBT is a thyroid disrupting chemical at the lowest concentrations tested. These studies complement the in vitro study used to identify MBT as a high priority for in vivo testing, supporting the utility/predictive potential of a tiered approach to testing chemicals for TPO activity inhibition. The 7-day study, with more comprehensive, sensitive, and diagnostic endpoints, provides information at intermediate biological levels that enables linking various endpoints in a robust and integrated pathway for thyroid hormone disruption associated with TPO inhibition.

MicroRNA-1297 inhibits prostate cancer cell proliferation and invasion by targeting the AEG-1/Wnt signaling pathway

International Nuclear Information System (INIS)

Liang, Xuan; Li, Hecheng; Fu, Delai; Chong, Tie; Wang, Ziming; Li, Zhaolun

2016-01-01

MicroRNAs (miRNAs) have been known to be implicated in tumorigenic programs. miR-1297 has been reported to be dysregulated and involved in cancer progression in many types of human cancers. However, the expression level and the role of miR-1297 in prostate cancer remain unclear. Herein, we aimed to investigate the potential role and molecular mechanism of miR-1297 in prostate cancer progression. We found that miR-1297 was significantly downregulated in human prostate cancer specimens as well as in several prostate cancer cell lines. In addition, functional experiments demonstrated that overexpression of miR-1297 remarkably inhibited prostate cancer cell proliferation and invasion whereas miR-1297 suppression significantly promoted prostate cancer cell proliferation and invasion. Bioinformatics analysis showed that the Astrocyte elevated gene-1 (AEG-1), a well-known oncogene, is a predicted target of miR-1297. Dual-luciferase reporter assay showed that miR-1297 was able to directly target the 3’-untranslated region of AEG-1. In addition, RT-qPCR and Western blot analysis showed that miR-1297 regulated the mRNA and protein expression levels of AEG-1. We also showed that miR-1297 was able to regulate the Wnt signaling pathway. Moreover, rescue assays indicated that AEG-1 contributed to miR-1297-endowed effects on cell proliferation and invasion as well as Wnt signaling pathway. Taken together, these findings suggest that miR-1297 inhibits prostate cancer proliferation and invasion by targeting AEG-1, thereby providing novel insight into understanding the pathogenesis of prostate cancer. Thus, miR-1297 may be a novel potential therapeutic candidate to treat prostate cancer. - Highlights: • miR-1297 is decreased in prostate cancer. • miR-1297 inhibits prostate cancer cell proliferation and invasion. • miR-1297 targets and inhibits AEG-1. • miR-1297 regulates AEG-1/Wnt signaling pathway.

Divergent Label-free Cell Phenotypic Pharmacology of Ligands at the Overexpressed β2-Adrenergic Receptors

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Ferrie, Ann M.; Sun, Haiyan; Zaytseva, Natalya; Fang, Ye

2014-01-01

We present subclone sensitive cell phenotypic pharmacology of ligands at the β2-adrenergic receptor (β2-AR) stably expressed in HEK-293 cells. The parental cell line was transfected with green fluorescent protein (GFP)-tagged β2-AR. Four stable subclones were established and used to profile a library of sixty-nine AR ligands. Dynamic mass redistribution (DMR) profiling resulted in a pharmacological activity map suggesting that HEK293 endogenously expresses functional Gi-coupled α2-AR and Gs-coupled β2-AR, and the label-free cell phenotypic activity of AR ligands are subclone dependent. Pathway deconvolution revealed that the DMR of epinephrine is originated mostly from the remodeling of actin microfilaments and adhesion complexes, to less extent from the microtubule networks and receptor trafficking, and certain agonists displayed different efficacy towards the cAMP-Epac pathway. We demonstrate that receptor signaling and ligand pharmacology is sensitive to the receptor expression level, and the organization of the receptor and its signaling circuitry.

Pifithrin-α provides neuroprotective effects at the level of mitochondria independently of p53 inhibition.

Science.gov (United States)

Neitemeier, Sandra; Ganjam, Goutham K; Diemert, Sebastian; Culmsee, Carsten

2014-12-01

Impaired mitochondrial integrity and function are key features of intrinsic death pathways in neuronal cells. Therefore, key regulators of intrinsic death pathways acting upstream of mitochondria are potential targets for therapeutic approaches of neuroprotection. The tumor suppressor p53 is a well-established regulator of cellular responses towards different kinds of lethal stress, including oxidative stress. Recent reports suggested that p53 may affect mitochondrial integrity and function through both, transcriptional activation of mitochondria-targeted pro-death proteins and direct effects at the mitochondrial membrane. In the present study, we compared the effects of pharmacological inhibition of p53 by pifithrin-α with those of selective p53 gene silencing by RNA interference. Using MTT assay and real-time cell impedance measurements we confirmed the protective effect of both strategies against glutamate-induced oxidative stress in immortalized mouse hippocampal HT-22 neurons. Further, we observed full restoration of mitochondrial membrane potential and inhibition of glutamate-induced mitochondrial fragmentation by pifithrin-α which was, in contrast, not achieved by p53 gene silencing. Downregulation of p53 by siRNA decreased p53 transcriptional activity and reduced expression levels of p21 mRNA, while pifithrin-α did not affect these endpoints. These results suggest a neuroprotective effect of pifithrin-α which occurred at the level of mitochondria and independently of p53 inhibition.

IL8-CXCR2 pathway inhibition as a therapeutic strategy against MDS and AML stem cells.

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Schinke, Carolina; Giricz, Orsolya; Li, Weijuan; Shastri, Aditi; Gordon, Shanisha; Barreyro, Laura; Barreryo, Laura; Bhagat, Tushar; Bhattacharyya, Sanchari; Ramachandra, Nandini; Bartenstein, Matthias; Pellagatti, Andrea; Boultwood, Jacqueline; Wickrema, Amittha; Yu, Yiting; Will, Britta; Wei, Sheng; Steidl, Ulrich; Verma, Amit

2015-05-14

Acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) are associated with disease-initiating stem cells that are not eliminated by conventional therapies. Novel therapeutic targets against preleukemic stem cells need to be identified for potentially curative strategies. We conducted parallel transcriptional analysis of highly fractionated stem and progenitor populations in MDS, AML, and control samples and found interleukin 8 (IL8) to be consistently overexpressed in patient samples. The receptor for IL8, CXCR2, was also significantly increased in MDS CD34(+) cells from a large clinical cohort and was predictive of increased transfusion dependence. High CXCR2 expression was also an adverse prognostic factor in The Cancer Genome Atlas AML cohort, further pointing to the critical role of the IL8-CXCR2 axis in AML/MDS. Functionally, CXCR2 inhibition by knockdown and pharmacologic approaches led to a significant reduction in proliferation in several leukemic cell lines and primary MDS/AML samples via induction of G0/G1 cell cycle arrest. Importantly, inhibition of CXCR2 selectively inhibited immature hematopoietic stem cells from MDS/AML samples without an effect on healthy controls. CXCR2 knockdown also impaired leukemic growth in vivo. Together, these studies demonstrate that the IL8 receptor CXCR2 is an adverse prognostic factor in MDS/AML and is a potential therapeutic target against immature leukemic stem cell-enriched cell fractions in MDS and AML. © 2015 by The American Society of Hematology.

Inhibition of MAPK and PKC pathways by 60Co γ-radiation in cultured vascular smooth muscle cells

International Nuclear Information System (INIS)

Jia Guanghong; Ma Yexin; Xiao Jianming

2002-01-01

Objective: To investigate the signal transduction pathways inhibited by 60 Co γ-radiation in cultured vascular smooth muscle cells (VSMC). Methods: The cultured VSMC were irradiated with 60 Co γ-radiation of 3.5, 7.0 and 14 Gy respectively. VSMC proliferation was measured by 3 H-TdR incorporation, while PKC, MAPK activities were determined by radioactivity assay. Results: Proliferation of VSMC was inhibited by 7.0, 14 Gy 60 Co γ-irradiation and the activities of PKC, MAPK were decreased significantly. Conclusion: Inhibitory effect of 7.0, 14 Gy 60 Co γ-irradiation on proliferation of VSMC might be resulted from decrease of the activity of PKC, MAPK

Nur77 inhibits oxLDL induced apoptosis of macrophages via the p38 MAPK signaling pathway

International Nuclear Information System (INIS)

Shao, Qin; Han, Fei; Peng, Shi; He, Ben

2016-01-01

The interaction between macrophages and oxLDL plays a crucial role in the initiation and progression of atherosclerosis. As a key initiator in a number of plaque promoting processes, oxLDL induces variable effects such as cell apoptosis or proliferation. Orphan nuclear receptor Nur77 is potently induced in macrophages by diverse stimuli, suggesting that it is of importance in vascular inflammation resulting in atherosclerosis, but whether Nur77 induction is detrimental or protective is unclear. In our study, we explore the role of Nur77 in the regulation of oxLDL-induced macrophage apoptosis and the signaling pathways that are involved. We found that oxLDL induced Nur77 expression in a dose and time dependent fashion, and cell viability was decreased in parallel. To determine whether Nur77 induction contributes to the loss of cell viability or is a protective mechanism, the effect of Nur77 overexpression was examined. Importantly, Nur77 overexpression inhibited the oxLDL-induced decrease of cell viability, inhibited the production of apoptotic bodies and restored DNA synthesis following oxLDL exposure. Furthermore, we found that Nur77 induction is mediated through the p38 MAPK signaling pathway. After pretreatment with SB203580, cell viability was decreased, the expression of CyclinA2 and PCNA was attenuated and the percentage of cell apoptosis was enhanced. Likewise, Nur77 overexpression increased the expression of the cell cycle genes PCNA and p21, and attenuated the increase in caspase-3. On the other hand, knockdown of Nur77 expression by specific siRNA resulted in the increased expression of caspase 3. The results demonstrate that Nur77 is induced by oxLDL via the p38 MAPK signaling pathway, which is involved in the regulation of cell survival. Nur77 enhanced cell survival via suppressing apoptosis, without affecting cell proliferation of activated macrophages, which may be beneficial in patients with atherosclerosis. - Highlights: • oxLDL could induce Nur77

Nur77 inhibits oxLDL induced apoptosis of macrophages via the p38 MAPK signaling pathway

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Shao, Qin; Han, Fei; Peng, Shi; He, Ben, E-mail: heben@medmail.com.cn

2016-03-18

The interaction between macrophages and oxLDL plays a crucial role in the initiation and progression of atherosclerosis. As a key initiator in a number of plaque promoting processes, oxLDL induces variable effects such as cell apoptosis or proliferation. Orphan nuclear receptor Nur77 is potently induced in macrophages by diverse stimuli, suggesting that it is of importance in vascular inflammation resulting in atherosclerosis, but whether Nur77 induction is detrimental or protective is unclear. In our study, we explore the role of Nur77 in the regulation of oxLDL-induced macrophage apoptosis and the signaling pathways that are involved. We found that oxLDL induced Nur77 expression in a dose and time dependent fashion, and cell viability was decreased in parallel. To determine whether Nur77 induction contributes to the loss of cell viability or is a protective mechanism, the effect of Nur77 overexpression was examined. Importantly, Nur77 overexpression inhibited the oxLDL-induced decrease of cell viability, inhibited the production of apoptotic bodies and restored DNA synthesis following oxLDL exposure. Furthermore, we found that Nur77 induction is mediated through the p38 MAPK signaling pathway. After pretreatment with SB203580, cell viability was decreased, the expression of CyclinA2 and PCNA was attenuated and the percentage of cell apoptosis was enhanced. Likewise, Nur77 overexpression increased the expression of the cell cycle genes PCNA and p21, and attenuated the increase in caspase-3. On the other hand, knockdown of Nur77 expression by specific siRNA resulted in the increased expression of caspase 3. The results demonstrate that Nur77 is induced by oxLDL via the p38 MAPK signaling pathway, which is involved in the regulation of cell survival. Nur77 enhanced cell survival via suppressing apoptosis, without affecting cell proliferation of activated macrophages, which may be beneficial in patients with atherosclerosis. - Highlights: • oxLDL could induce Nur77

Foot-and-mouth disease virus non-structural protein 3A inhibits the interferon-β signaling pathway

Science.gov (United States)

Li, Dan; Lei, Caoqi; Xu, Zhisheng; Yang, Fan; Liu, Huanan; Zhu, Zixiang; Li, Shu; Liu, Xiangtao; Shu, Hongbing; Zheng, Haixue

2016-01-01

Foot-and-mouth disease virus (FMDV) is the etiological agent of FMD, which affects cloven-hoofed animals. The pathophysiology of FMDV has not been fully understood and the evasion of host innate immune system is still unclear. Here, the FMDV non-structural protein 3A was identified as a negative regulator of virus-triggered IFN-β signaling pathway. Overexpression of the FMDV 3A inhibited Sendai virus-triggered activation of IRF3 and the expressions of RIG-I/MDA5. Transient transfection and co-immunoprecipitation experiments suggested that FMDV 3A interacts with RIG-I, MDA5 and VISA, which is dependent on the N-terminal 51 amino acids of 3A. Furthermore, 3A also inhibited the expressions of RIG-I, MDA5, and VISA by disrupting their mRNA levels. These results demonstrated that 3A inhibits the RLR-mediated IFN-β induction and uncovered a novel mechanism by which the FMDV 3A protein evades the host innate immune system. PMID:26883855

Pharmacologic study of calcium influx pathways in rabbit aortic smooth muscle

International Nuclear Information System (INIS)

Lukeman, D.S.

1987-01-01

Functional characteristics and pharmacologic domains of receptor-operated and potential-sensitive calcium (Ca 2+ ) channels (ROCs and PSCs, respectively) were derived via measurements of 45 Ca 2+ influx (M/sup Ca/) during activation by the neurotransmitters norepinephrine (NE), histamine (HS), and serotonin (5-HT) and by elevated extracellular potassium (K + ) in the individual or combined presence of organic Ca 2+ channel antagonists (CAts), calmodulin antagonists (Calm-ants), lanthanum (La 3+ ), and agents that increase intracellular levels of cyclic AMP

Cholinergic anti-inflammatory pathway inhibits neointimal hyperplasia by suppressing inflammation and oxidative stress

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Dong-Jie Li

2018-05-01

Full Text Available Neointimal hyperplasia as a consequence of vascular injury is aggravated by inflammatory reaction and oxidative stress. The α7 nicotinic acetylcholine receptor (α7nAChR is a orchestrator of cholinergic anti-inflammatory pathway (CAP, which refers to a physiological neuro-immune mechanism that restricts inflammation. Here, we investigated the potential role of CAP in neointimal hyperplasia using α7nAChR knockout (KO mice. Male α7nAChR-KO mice and their wild-type control mice (WT were subjected to wire injury in left common carotid artery. At 4 weeks post injury, the injured aortae were isolated for examination. The neointimal hyperplasia after wire injury was significantly aggravated in α7nAChR-KO mice compared with WT mice. The α7nAChR-KO mice had increased collagen contents and vascular smooth muscle cells (VSMCs amount. Moreover, the inflammation was significantly enhanced in the neointima of α7nAChR-KO mice relative to WT mice, evidenced by the increased expression of tumor necrosis factor-α/interleukin-1β, and macrophage infiltration. Meanwhile, the chemokines chemokine (C-C motif ligand 2 and chemokine (CXC motif ligand 2 expression was also augmented in the neointima of α7nAChR-KO mice compared with WT mice. Additionally, the depletion of superoxide dismutase (SOD and reduced glutathione (GSH, and the upregulation of 3-nitrotyrosine, malondialdehyde and myeloperoxidase were more pronounced in neointima of α7nAChR-KO mice compared with WT mice. Accordingly, the protein expression of NADPH oxidase 1 (Nox1, Nox2 and Nox4, was also higher in neointima of α7nAChR-KO mice compared with WT mice. Finally, pharmacologically activation of CAP with a selective α7nAChR agonist PNU-282987, significantly reduced neointima formation, arterial inflammation and oxidative stress after vascular injury in C57BL/6 mice. In conclusion, our results demonstrate that α7nAChR-mediated CAP is a neuro-physiological mechanism that inhibits neointima

cGMP-phosphodiesterase inhibition enhances photic responses and synchronization of the biological circadian clock in rodents.

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Santiago A Plano

Full Text Available The master circadian clock in mammals is located in the hypothalamic suprachiasmatic nuclei (SCN and is synchronized by several environmental stimuli, mainly the light-dark (LD cycle. Light pulses in the late subjective night induce phase advances in locomotor circadian rhythms and the expression of clock genes (such as Per1-2. The mechanism responsible for light-induced phase advances involves the activation of guanylyl cyclase (GC, cGMP and its related protein kinase (PKG. Pharmacological manipulation of cGMP by phosphodiesterase (PDE inhibition (e.g., sildenafil increases low-intensity light-induced circadian responses, which could reflect the ability of the cGMP-dependent pathway to directly affect the photic sensitivity of the master circadian clock within the SCN. Indeed, sildenafil is also able to increase the phase-shifting effect of saturating (1200 lux light pulses leading to phase advances of about 9 hours, as well as in C57 a mouse strain that shows reduced phase advances. In addition, sildenafil was effective in both male and female hamsters, as well as after oral administration. Other PDE inhibitors (such as vardenafil and tadalafil also increased light-induced phase advances of locomotor activity rhythms and accelerated reentrainment after a phase advance in the LD cycle. Pharmacological inhibition of the main downstream target of cGMP, PKG, blocked light-induced expression of Per1. Our results indicate that the cGMP-dependent pathway can directly modulate the light-induced expression of clock-genes within the SCN and the magnitude of light-induced phase advances of overt rhythms, and provide promising tools to design treatments for human circadian disruptions.

Compound K, a Ginsenoside Metabolite, Inhibits Colon Cancer Growth via Multiple Pathways Including p53-p21 Interactions

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Eugene B. Chang

2013-01-01

Full Text Available Compound K (20-O-beta-D-glucopyranosyl-20(S-protopanaxadiol, CK, an intestinal bacterial metabolite of ginseng protopanaxadiol saponins, has been shown to inhibit cell growth in a variety of cancers. However, the mechanisms are not completely understood, especially in colorectal cancer (CRC. A xenograft tumor model was used first to examine the anti-CRC effect of CK in vivo. Then, multiple in vitro assays were applied to investigate the anticancer effects of CK including antiproliferation, apoptosis and cell cycle distribution. In addition, a qPCR array and western blot analysis were executed to screen and validate the molecules and pathways involved. We observed that CK significantly inhibited the growth of HCT-116 tumors in an athymic nude mouse xenograft model. CK significantly inhibited the proliferation of human CRC cell lines HCT-116, SW-480, and HT-29 in a dose- and time-dependent manner. We also observed that CK induced cell apoptosis and arrested the cell cycle in the G1 phase in HCT-116 cells. The processes were related to the upregulation of p53/p21, FoxO3a-p27/p15 and Smad3, and downregulation of cdc25A, CDK4/6 and cyclin D1/3. The major regulated targets of CK were cyclin dependent inhibitors, including p21, p27, and p15. These results indicate that CK inhibits transcriptional activation of multiple tumor-promoting pathways in CRC, suggesting that CK could be an active compound in the prevention or treatment of CRC.

Incretin-based therapies– review of the physiology, pharmacology and emerging clinical experience

DEFF Research Database (Denmark)

Martin, JH; Deacon, Carolyn F.; Gorrell, MD

2011-01-01

in type 2 diabetes, leading to development of strategies aimed at redressing this abnormality. These strategies include pharmacological inhibition of dipeptidyl peptidase-4, the enzyme responsible for the short half-life of endogenous incretins, and administration of long-acting dipeptidyl peptidase-4...

Atorvastatin calcium inhibits phenotypic modulation of PDGF-BB-induced VSMCs via down-regulation the Akt signaling pathway.

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Chen, Shuang; Liu, Baoqin; Kong, Dehui; Li, Si; Li, Chao; Wang, Huaqin; Sun, Yingxian

2015-01-01

Plasticity of vascular smooth muscle cells (VSMCs) plays a central role in the onset and progression of proliferative vascular diseases. In adult tissue, VSMCs exist in a physiological contractile-quiescent phenotype, which is defined by lack of the ability of proliferation and migration, while high expression of contractile marker proteins. After injury to the vessel, VSMC shifts from a contractile phenotype to a pathological synthetic phenotype, associated with increased proliferation, migration and matrix secretion. It has been demonstrated that PDGF-BB is a critical mediator of VSMCs phenotypic switch. Atorvastatin calcium, a selective inhibitor of 3-hydroxy-3-methyl-glutaryl l coenzyme A (HMG-CoA) reductase, exhibits various protective effects against VSMCs. In this study, we investigated the effects of atorvastatin calcium on phenotype modulation of PDGF-BB-induced VSMCs and the related intracellular signal transduction pathways. Treatment of VSMCs with atorvastatin calcium showed dose-dependent inhibition of PDGF-BB-induced proliferation. Atorvastatin calcium co-treatment inhibited the phenotype modulation and cytoskeleton rearrangements and improved the expression of contractile phenotype marker proteins such as α-SM actin, SM22α and calponin in comparison with PDGF-BB alone stimulated VSMCs. Although Akt phosphorylation was strongly elicited by PDGF-BB, Akt activation was attenuated when PDGF-BB was co-administrated with atorvastatin calcium. In conclusion, atorvastatin calcium inhibits phenotype modulation of PDGF-BB-induced VSMCs and activation of the Akt signaling pathway, indicating that Akt might play a vital role in the modulation of phenotype.

Ethanol negatively regulates hepatic differentiation of hESC by inhibition of the MAPK/ERK signaling pathway in vitro.

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Wei Gao

Full Text Available Alcohol insult triggers complex events in the liver, promoting fibrogenic/inflammatory signals and in more advanced cases, aberrant matrix deposition. It is well accepted that the regenerative capacity of the adult liver is impaired during alcohol injury. The liver progenitor/stem cells have been shown to play an important role in liver regeneration -in response to various chronic injuries; however, the effects of alcohol on stem cell differentiation in the liver are not well understood.We employed hepatic progenitor cells derived from hESCs to study the impact of ethanol on hepatocyte differentiation by exposure of these progenitor cells to ethanol during hepatocyte differentiation.We found that ethanol negatively regulated hepatic differentiation of hESC-derived hepatic progenitor cells in a dose-dependent manner. There was also a moderate cell cycle arrest at G1/S checkpoint in the ethanol treated cells, which is associated with a reduced level of cyclin D1 in these cells. Ethanol treatment specifically inhibited the activation of the ERK but not JNK nor the p38 MAP signaling pathway. At the same time, the WNT signaling pathway was also reduced in the cells exposed to ethanol. Upon evaluating the effects of the inhibitors of these two signaling pathways, we determined that the Erk inhibitor replicated the effects of ethanol on the hepatocyte differentiation and attenuated the WNT/β-catenin signaling, however, inhibitors of WNT only partially replicated the effects of ethanol on the hepatocyte differentiation.Our results demonstrated that ethanol negatively regulated hepatic differentiation of hESC-derived hepatic progenitors through inhibiting the MAPK/ERK signaling pathway, and subsequently attenuating the WNT signaling pathway. Thus, our finding provides a novel insight into the mechanism by which alcohol regulates cell fate selection of hESC-derived hepatic progenitor cells, and the identified pathways may provide therapeutic targets

Glycogen Synthase Kinase 3β Inhibition as a Therapeutic Approach in the Treatment of Endometrial Cancer

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Liang Ma

2013-08-01

Full Text Available Alternative strategies beyond current chemotherapy and radiation therapy regimens are needed in the treatment of advanced stage and recurrent endometrial cancers. There is considerable promise for biologic agents targeting the extracellular signal-regulated kinase (ERK pathway for treatment of these cancers. Many downstream substrates of the ERK signaling pathway, such as glycogen synthase kinase 3β (GSK3β, and their roles in endometrial carcinogenesis have not yet been investigated. In this study, we tested the importance of GSK3β inhibition in endometrial cancer cell lines and in vivo models. Inhibition of GSK3β by either lithium chloride (LiCl or specific GSK3β inhibitor VIII showed cytostatic and cytotoxic effects on multiple endometrial cancer cell lines, with little effect on the immortalized normal endometrial cell line. Flow cytometry and immunofluorescence revealed a G2/M cell cycle arrest in both type I (AN3CA, KLE, and RL952 and type II (ARK1 endometrial cancer cell lines. In addition, LiCl pre-treatment sensitized AN3CA cells to the chemotherapy agent paclitaxel. Administration of LiCl to AN3CA tumor-bearing mice resulted in partial or complete regression of some tumors. Thus, GSK3β activity is associated with endometrial cancer tumorigenesis and its pharmacologic inhibition reduces cell proliferation and tumor growth.

Pharmacological inhibition of the chemokine CXCL16 diminishes liver macrophage infiltration and steatohepatitis in chronic hepatic injury.

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Alexander Wehr

Full Text Available Non-alcoholic fatty liver disease (NAFLD is a major cause of morbidity and mortality in developed countries, resulting in steatohepatitis (NASH, fibrosis and eventually cirrhosis. Modulating inflammatory mediators such as chemokines may represent a novel therapeutic strategy for NAFLD. We recently demonstrated that the chemokine receptor CXCR6 promotes hepatic NKT cell accumulation, thereby controlling inflammation in experimental NAFLD. In this study, we first investigated human biopsies (n = 20, confirming that accumulation of inflammatory cells such as macrophages is a hallmark of progressive NAFLD. Moreover, CXCR6 gene expression correlated with the inflammatory activity (ALT levels in human NAFLD. We then tested the hypothesis that pharmacological inhibition of CXCL16 might hold therapeutic potential in NAFLD, using mouse models of acute carbon tetrachloride (CCl4- and chronic methionine-choline-deficient (MCD diet-induced hepatic injury. Neutralizing CXCL16 by i.p. injection of anti-CXCL16 antibody inhibited the early intrahepatic NKT cell accumulation upon acute toxic injury in vivo. Weekly therapeutic anti-CXCL16 administrations during the last 3 weeks of 6 weeks MCD diet significantly decreased the infiltration of inflammatory macrophages into the liver and intrahepatic levels of inflammatory cytokines like TNF or MCP-1. Importantly, anti-CXCL16 treatment significantly reduced fatty liver degeneration upon MCD diet, as assessed by hepatic triglyceride levels, histological steatosis scoring and quantification of lipid droplets. Moreover, injured hepatocytes up-regulated CXCL16 expression, indicating that scavenging functions of CXCL16 might be additionally involved in the pathogenesis of NAFLD. Targeting CXCL16 might therefore represent a promising novel therapeutic approach for liver inflammation and steatohepatitis.

3-Bromopyruvate treatment induces alterations of metabolic and stress-related pathways in glioblastoma cells.

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Chiasserini, Davide; Davidescu, Magdalena; Orvietani, Pier Luigi; Susta, Federica; Macchioni, Lara; Petricciuolo, Maya; Castigli, Emilia; Roberti, Rita; Binaglia, Luciano; Corazzi, Lanfranco

2017-01-30

Glioblastoma (GBM) is the most common and aggressive brain tumour of adults. The metabolic phenotype of GBM cells is highly dependent on glycolysis; therefore, therapeutic strategies aimed at interfering with glycolytic pathways are under consideration. 3-Bromopyruvate (3BP) is a potent antiglycolytic agent, with a variety of targets and possible effects on global cell metabolism. Here we analyzed the changes in protein expression on a GBM cell line (GL15 cells) caused by 3BP treatment using a global proteomic approach. Validation of differential protein expression was performed with immunoblotting and enzyme activity assays in GL15 and U251 cell lines. The results show that treatment of GL15 cells with 3BP leads to extensive changes in the expression of glycolytic enzymes and stress related proteins. Importantly, other metabolisms were also affected, including pentose phosphate pathway, aminoacid synthesis, and glucose derivatives production. 3BP elicited the activation of stress response proteins, as shown by the phosphorylation of HSPB1 at serine 82, caused by the concomitant activation of the p38 pathway. Our results show that inhibition of glycolysis in GL15 cells by 3BP influences different but interconnected pathways. Proteome analysis may help in the molecular characterization of the glioblastoma response induced by pharmacological treatment with antiglycolytic agents. Alteration of the glycolytic pathway characterizes glioblastoma (GBM), one of the most common brain tumours. Metabolic reprogramming with agents able to inhibit carbohydrate metabolism might be a viable strategy to complement the treatment of these tumours. The antiglycolytic agent 3-bromopyruvate (3BP) is able to strongly inhibit glycolysis but it may affect also other cellular pathways and its precise cellular targets are currently unknown. To understand the protein expression changes induced by 3BP, we performed a global proteomic analysis of a GBM cell line (GL15) treated with 3BP. We

Viral MicroRNAs Repress the Cholesterol Pathway, and 25-Hydroxycholesterol Inhibits Infection.

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Serquiña, Anna K P; Kambach, Diane M; Sarker, Ontara; Ziegelbauer, Joseph M

2017-07-11

From various screens, we found that Kaposi's sarcoma-associated herpesvirus (KSHV) viral microRNAs (miRNAs) target several enzymes in the mevalonate/cholesterol pathway. 3-Hydroxy-3-methylglutaryl-coenzyme A (CoA) synthase 1 (HMGCS1), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR [a rate-limiting step in the mevalonate pathway]), and farnesyl-diphosphate farnesyltransferase 1 (FDFT1 [a committed step in the cholesterol branch]) are repressed by multiple KSHV miRNAs. Transfection of viral miRNA mimics in primary endothelial cells (human umbilical vein endothelial cells [HUVECs]) is sufficient to reduce intracellular cholesterol levels; however, small interfering RNAs (siRNAs) targeting only HMGCS1 did not reduce cholesterol levels. This suggests that multiple targets are needed to perturb this tightly regulated pathway. We also report here that cholesterol levels were decreased in de novo -infected HUVECs after 7 days. This reduction is at least partially due to viral miRNAs, since the mutant form of KSHV lacking 10 of the 12 miRNA genes had increased cholesterol compared to wild-type infections. We hypothesized that KSHV is downregulating cholesterol to suppress the antiviral response by a modified form of cholesterol, 25-hydroxycholesterol (25HC). We found that the cholesterol 25-hydroxylase (CH25H) gene, which is responsible for generating 25HC, had increased expression in de novo -infected HUVECs but was strongly suppressed in long-term latently infected cell lines. We found that 25HC inhibits KSHV infection when added exogenously prior to de novo infection. In conclusion, we found that multiple KSHV viral miRNAs target enzymes in the mevalonate pathway to modulate cholesterol in infected cells during latency. This repression of cholesterol levels could potentially be beneficial to viral infection by decreasing the levels of 25HC. IMPORTANCE A subset of viruses express unique microRNAs (miRNAs), which act like cellular miRNAs to generally repress host gene

Pathogenic mycobacteria achieve cellular persistence by inhibiting the Niemann-Pick Type C disease cellular pathway.

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Fineran, Paul; Lloyd-Evans, Emyr; Lack, Nathan A; Platt, Nick; Davis, Lianne C; Morgan, Anthony J; Höglinger, Doris; Tatituri, Raju Venkata V; Clark, Simon; Williams, Ian M; Tynan, Patricia; Al Eisa, Nada; Nazarova, Evgeniya; Williams, Ann; Galione, Antony; Ory, Daniel S; Besra, Gurdyal S; Russell, David G; Brenner, Michael B; Sim, Edith; Platt, Frances M

2016-11-18

Tuberculosis remains a major global health concern. The ability to prevent phagosome-lysosome fusion is a key mechanism by which intracellular mycobacteria, including Mycobacterium tuberculosis , achieve long-term persistence within host cells. The mechanisms underpinning this key intracellular pro-survival strategy remain incompletely understood. Host macrophages infected with persistent mycobacteria share phenotypic similarities with cells taken from patients suffering from Niemann-Pick Disease Type C (NPC), a rare lysosomal storage disease in which endocytic trafficking defects and lipid accumulation within the lysosome lead to cell dysfunction and cell death. We investigated whether these shared phenotypes reflected an underlying mechanistic connection between mycobacterial intracellular persistence and the host cell pathway dysfunctional in NPC. The induction of NPC phenotypes in macrophages from wild-type mice or obtained from healthy human donors was assessed via infection with mycobacteria and subsequent measurement of lipid levels and intracellular calcium homeostasis. The effect of NPC therapeutics on intracellular mycobacterial load was also assessed. Macrophages infected with persistent intracellular mycobacteria phenocopied NPC cells, exhibiting accumulation of multiple lipid types, reduced lysosomal Ca 2+ levels, and defects in intracellular trafficking. These NPC phenotypes could also be induced using only lipids/glycomycolates from the mycobacterial cell wall. These data suggest that persistent intracellular mycobacteria inhibit the NPC pathway, likely via inhibition of the NPC1 protein, and subsequently induce altered acidic store Ca 2+ homeostasis. Reduced lysosomal calcium levels may provide a mechanistic explanation for the reduced levels of phagosome-lysosome fusion in mycobacterial infection. Treatments capable of correcting defects in NPC mutant cells via modulation of host cell calcium were of benefit in promoting clearance of mycobacteria

Phytochemistry, pharmacology, and clinical trials of Morus alba.

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Chan, Eric Wei-Chiang; Lye, Phui-Yan; Wong, Siu-Kuin

2016-01-01

The present review is aimed at providing a comprehensive summary on the botany, utility, phytochemistry, pharmacology, and clinical trials of Morus alba (mulberry or sang shu). The mulberry foliage has remained the primary food for silkworms for centuries. Its leaves have also been used as animal feed for livestock and its fruits have been made into a variety of food products. With flavonoids as major constituents, mulberry leaves possess various biological activities, including antioxidant, antimicrobial, skin-whitening, cytotoxic, anti-diabetic, glucosidase inhibition, anti-hyperlipidemic, anti-atherosclerotic, anti-obesity, cardioprotective, and cognitive enhancement activities. Rich in anthocyanins and alkaloids, mulberry fruits have pharmacological properties, such as antioxidant, anti-diabetic, anti-atherosclerotic, anti-obesity, and hepatoprotective activities. The root bark of mulberry, containing flavonoids, alkaloids and stilbenoids, has antimicrobial, skin-whitening, cytotoxic, anti-inflammatory, and anti-hyperlipidemic properties. Other pharmacological properties of M. alba include anti-platelet, anxiolytic, anti-asthmatic, anthelmintic, antidepressant, cardioprotective, and immunomodulatory activities. Clinical trials on the efficiency of M. alba extracts in reducing blood glucose and cholesterol levels and enhancing cognitive ability have been conducted. The phytochemistry and pharmacology of the different parts of the mulberry tree confer its traditional and current uses as fodder, food, cosmetics, and medicine. Overall, M. alba is a multi-functional plant with promising medicinal properties. Copyright © 2016 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

On the Molecular Pharmacology of Resveratrol on Oxidative Burst Inhibition in Professional Phagocytes

Czech Academy of Sciences Publication Activity Database

Nosáľ, R.; Drábiková, K.; Jančinová, V.; Perečko, T.; Ambrožová, Gabriela; Číž, Milan; Lojek, Antonín; Pekarová, Michaela; Šmidrkal, J.; Harmatha, Juraj

2014-01-01

Roč. 2014, Jan 28 (2014), 706269/1-706269/9 ISSN 1942-0900 Institutional support: RVO:61388963 ; RVO:68081707 Keywords : resveratrol * oxidative burst * human neutrophils Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 3.516, year: 2014 http://www.hindawi.com/journals/omcl/2014/706269/

PPARα inhibition modulates multiple reprogrammed metabolic pathways in kidney cancer and attenuates tumor growth.

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Abu Aboud, Omran; Donohoe, Dallas; Bultman, Scott; Fitch, Mark; Riiff, Tim; Hellerstein, Marc; Weiss, Robert H

2015-06-01

Kidney cancer [renal cell carcinoma (RCC)] is the sixth-most-common cancer in the United States, and its incidence is increasing. The current progression-free survival for patients with advanced RCC rarely extends beyond 1-2 yr due to the development of therapeutic resistance. We previously identified peroxisome proliferator-activating receptor-α (PPARα) as a potential therapeutic target for this disease and showed that a specific PPARα antagonist, GW6471, induced apoptosis and cell cycle arrest at G0/G1 in RCC cell lines associated with attenuation of cell cycle regulatory proteins. We now extend that work and show that PPARα inhibition attenuates components of RCC metabolic reprogramming, capitalizing on the Warburg effect. The specific PPARα inhibitor GW6471, as well as a siRNA specific to PPARα, attenuates the enhanced fatty acid oxidation and oxidative phosphorylation associated with glycolysis inhibition, and PPARα antagonism also blocks the enhanced glycolysis that has been observed in RCC cells; this effect did not occur in normal human kidney epithelial cells. Such cell type-specific inhibition of glycolysis corresponds with changes in protein levels of the oncogene c-Myc and has promising clinical implications. Furthermore, we show that treatment with GW6471 results in RCC tumor growth attenuation in a xenograft mouse model, with minimal obvious toxicity, a finding associated with the expected on-target effects on c-Myc. These studies demonstrate that several pivotal cancer-relevant metabolic pathways are inhibited by PPARα antagonism. Our data support the concept that targeting PPARα, with or without concurrent inhibition of glycolysis, is a potential novel and effective therapeutic approach for RCC that targets metabolic reprogramming in this tumor.

Inhibition of IKKβ Reduces Ethanol Consumption in C57BL/6J Mice.

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Truitt, Jay M; Blednov, Yuri A; Benavidez, Jillian M; Black, Mendy; Ponomareva, Olga; Law, Jade; Merriman, Morgan; Horani, Sami; Jameson, Kelly; Lasek, Amy W; Harris, R Adron; Mayfield, R Dayne

2016-01-01

Proinflammatory pathways in neuronal and non-neuronal cells are implicated in the acute and chronic effects of alcohol exposure in animal models and humans. The nuclear factor-κB (NF-κB) family of DNA transcription factors plays important roles in inflammatory diseases. The kinase IKKβ mediates the phosphorylation and subsequent proteasomal degradation of cytosolic protein inhibitors of NF-κB, leading to activation of NF-κB. The role of IKKβ as a potential regulator of excessive alcohol drinking had not previously been investigated. Based on previous findings that the overactivation of innate immune/inflammatory signaling promotes ethanol consumption, we hypothesized that inhibiting IKKβ would limit/decrease drinking by preventing the activation of NF-κB. We studied the systemic effects of two pharmacological inhibitors of IKKβ, TPCA-1 and sulfasalazine, on ethanol intake using continuous- and limited-access, two-bottle choice drinking tests in C57BL/6J mice. In both tests, TPCA-1 and sulfasalazine reduced ethanol intake and preference without changing total fluid intake or sweet taste preference. A virus expressing Cre recombinase was injected into the nucleus accumbens and central amygdala to selectively knock down IKKβ in mice genetically engineered with a conditional Ikkb deletion ( Ikkb F/F ). Although IKKβ was inhibited to some extent in astrocytes and microglia, neurons were a primary cellular target. Deletion of IKKβ in either brain region reduced ethanol intake and preference in the continuous access two-bottle choice test without altering the preference for sucrose. Pharmacological and genetic inhibition of IKKβ decreased voluntary ethanol consumption, providing initial support for IKKβ as a potential therapeutic target for alcohol abuse.

Impact of the Smoothened inhibitor, IPI-926, on smoothened ciliary localization and Hedgehog pathway activity.

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Marisa O Peluso

unique biophysical and pharmacological properties that result in Hh pathway inhibition in a manner that differentiates it from cyclopamine.

Celastrol inhibits chondrosarcoma proliferation, migration and invasion through suppression CIP2A/c-MYC signaling pathway

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Jinhui Wu

2017-05-01

Full Text Available Chondrosarcomas (CS is the second most frequent tumors of cartilage origin. A small compound extracted from Thunder God Vine (Tripterygium wilfordii Hook. F. called celastrol can directly bound CIP2A protein and effectively inhibit cell proliferation and induce apoptosis in several cancer cells. However, little knowledge is concern about the important role of CIP2A in CS patients and the therapeutic value of celastrol on CS. Our results showed that CIP2A and c-MYC were verified to be oncoproteins by detecting their mRNA and protein expression in 10 human CS tissues by qRT-PCR and Western blots. After treatment of celastrol, the proliferation, migration and invasion were significantly inhibited; whereas the apoptosis was largely induced in human CS cell lines. In addition, celastrol inhibited the expression of CIP2A, c-MYC, and suppressed apoptotic proteins BAX and caspase-8 in human CS cells, on the other hand, it induced the expression of antiapoptotic protein Bcl-2. Finally, knockdown of CIP2A also inhibited the migration and invasion and induced apoptosis of human CS cells. To sum up, we found that celastrol had effects on inhibiting proliferation, migration, invasion and inducing apoptosis through suppression CIP2A/c-MYC signaling pathway in vitro, which may provide a new therapeutic regimen for CS.

Silibinin inhibits migration and invasion of the rhabdoid tumor G401 cell line via inactivation of the PI3K/Akt signaling pathway.

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Li, Yumei; Zhang, Chunmei; Cai, Danfeng; Chen, Congde; Mu, Dongmei

2017-12-01

Rhabdoid tumors, which tend to occur prior to the age of 2 years, are one of the most aggressive malignancies and have a poor prognosis due to the frequency of metastasis. Silibinin, a natural extract, has been approved as a potential tumor suppressor in various studies, however, whether or not it also exerts its antitumor capacity in rhabdoid tumors, particularly with regards to tumor migration and invasion, is unclear. The rhabdoid tumor G401 cell line was used in the present in vitro study. An MTT assay was used to assess the cytotoxicity of silibinin on G401 cells, cell migration was studied using a wound healing assay and a Transwell migration assay, and cell invasion was determined using a Transwell invasion assay. The underlying mechanism in silibinin inhibited cell migration and invasion was investigated by western blot analysis and further confirmed using a specific inhibitor. Experimental results demonstrated that high doses of silibinin suppressed cell viability, and that low doses of silibinin inhibited cell migration and invasion without affecting cell proliferation. The phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway was involved in the silibinin-induced inhibition of metastasis. Silibinin inactivated the PI3K/Akt pathway, and inhibited cell migration and invasion, an effect that was further enhanced when LY294002, a classic PI3K inhibitor, was used concurrently. In general, silibinin inhibits migration and invasion of the rhabdoid tumor G401 cell line via inactivation of the PI3K/Akt signaling pathway and may be a potential chemotherapeutic drug to combat rhabdoid tumors in the future.

Site-targeted complement inhibition by a complement receptor 2-conjugated inhibitor (mTT30) ameliorates post-injury neuropathology in mouse brains.

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Rich, Megan C; Keene, Chesleigh N; Neher, Miriam D; Johnson, Krista; Yu, Zhao-Xue; Ganivet, Antoine; Holers, V Michael; Stahel, Philip F

2016-03-23

Intracerebral complement activation after severe traumatic brain injury (TBI) leads to a cascade of neuroinflammatory pathological sequelae that propagate host-mediated secondary brain injury and adverse outcomes. There are currently no specific pharmacological agents on the market to prevent or mitigate the development of secondary cerebral insults after TBI. A novel chimeric CR2-fH compound (mTT30) provides targeted inhibition of the alternative complement pathway at the site of tissue injury. This experimental study was designed to test the neuroprotective effects of mTT30 in a mouse model of closed head injury. The administration of 500 μg mTT30 i.v. at 1 h, 4 h and 24 h after head injury attenuated complement C3 deposition in injured brains, reduced the extent of neuronal cell death, and decreased post-injury microglial activation, compared to vehicle-injected placebo controls. These data imply that site-targeted alternative pathway complement inhibition may represent a new promising therapeutic avenue for the future management of severe TBI. Copyright © 2016. Published by Elsevier Ireland Ltd.

M-COPA suppresses endolysosomal Kit-Akt oncogenic signalling through inhibiting the secretory pathway in neoplastic mast cells.

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Yasushi Hara

Full Text Available Gain-of-function mutations in Kit receptor tyrosine kinase result in the development of a variety of cancers, such as mast cell tumours, gastrointestinal stromal tumours (GISTs, acute myeloid leukemia, and melanomas. The drug imatinib, a selective inhibitor of Kit, is used for treatment of mutant Kit-positive cancers. However, mutations in the Kit kinase domain, which are frequently found in neoplastic mast cells, confer an imatinib resistance, and cancers expressing the mutants can proliferate in the presence of imatinib. Recently, we showed that in neoplastic mast cells that endogenously express an imatinib-resistant Kit mutant, Kit causes oncogenic activation of the phosphatidylinositol 3-kinase-Akt (PI3K-Akt pathway and the signal transducer and activator of transcription 5 (STAT5 but only on endolysosomes and on the endoplasmic reticulum (ER, respectively. Here, we show a strategy for inhibition of the Kit-PI3K-Akt pathway in neoplastic mast cells by M-COPA (2-methylcoprophilinamide, an inhibitor of this secretory pathway. In M-COPA-treated cells, Kit localization in the ER is significantly increased, whereas endolysosomal Kit disappears, indicating that M-COPA blocks the biosynthetic transport of Kit from the ER. The drug greatly inhibits oncogenic Akt activation without affecting the association of Kit with PI3K, indicating that ER-localized Kit-PI3K complex is unable to activate Akt. Importantly, M-COPA but not imatinib suppresses neoplastic mast cell proliferation through inhibiting anti-apoptotic Akt activation. Results of our M-COPA treatment assay show that Kit can activate Erk not only on the ER but also on other compartments. Furthermore, Tyr568/570, Tyr703, Tyr721, and Tyr936 in Kit are phosphorylated on the ER, indicating that these five tyrosine residues are all phosphorylated before mutant Kit reaches the plasma membrane (PM. Our study provides evidence that Kit is tyrosine-phosphorylated soon after synthesis on the ER but is

M-COPA suppresses endolysosomal Kit-Akt oncogenic signalling through inhibiting the secretory pathway in neoplastic mast cells.

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Hara, Yasushi; Obata, Yuuki; Horikawa, Keita; Tasaki, Yasutaka; Suzuki, Kyohei; Murata, Takatsugu; Shiina, Isamu; Abe, Ryo

2017-01-01

Gain-of-function mutations in Kit receptor tyrosine kinase result in the development of a variety of cancers, such as mast cell tumours, gastrointestinal stromal tumours (GISTs), acute myeloid leukemia, and melanomas. The drug imatinib, a selective inhibitor of Kit, is used for treatment of mutant Kit-positive cancers. However, mutations in the Kit kinase domain, which are frequently found in neoplastic mast cells, confer an imatinib resistance, and cancers expressing the mutants can proliferate in the presence of imatinib. Recently, we showed that in neoplastic mast cells that endogenously express an imatinib-resistant Kit mutant, Kit causes oncogenic activation of the phosphatidylinositol 3-kinase-Akt (PI3K-Akt) pathway and the signal transducer and activator of transcription 5 (STAT5) but only on endolysosomes and on the endoplasmic reticulum (ER), respectively. Here, we show a strategy for inhibition of the Kit-PI3K-Akt pathway in neoplastic mast cells by M-COPA (2-methylcoprophilinamide), an inhibitor of this secretory pathway. In M-COPA-treated cells, Kit localization in the ER is significantly increased, whereas endolysosomal Kit disappears, indicating that M-COPA blocks the biosynthetic transport of Kit from the ER. The drug greatly inhibits oncogenic Akt activation without affecting the association of Kit with PI3K, indicating that ER-localized Kit-PI3K complex is unable to activate Akt. Importantly, M-COPA but not imatinib suppresses neoplastic mast cell proliferation through inhibiting anti-apoptotic Akt activation. Results of our M-COPA treatment assay show that Kit can activate Erk not only on the ER but also on other compartments. Furthermore, Tyr568/570, Tyr703, Tyr721, and Tyr936 in Kit are phosphorylated on the ER, indicating that these five tyrosine residues are all phosphorylated before mutant Kit reaches the plasma membrane (PM). Our study provides evidence that Kit is tyrosine-phosphorylated soon after synthesis on the ER but is unable to

Epigenetic Histone Deacetylation Inhibition Prevents the Development and Persistence of Temporal Lobe Epilepsy.

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Reddy, Sandesh D; Clossen, Bryan L; Reddy, Doodipala Samba

2018-01-01

Epilepsy is a chronic brain disease characterized by repeated unprovoked seizures. Currently, no drug therapy exists for curing epilepsy or disease modification in people at risk. Despite several emerging mechanisms, there have been few studies of epigenetic signaling in epileptogenesis, the process whereby a normal brain becomes progressively epileptic because of precipitating factors. Here, we report a novel role of histone deacetylation as a critical epigenetic mechanism in epileptogenesis. Experiments were conducted using the histone deacetylase (HDAC) inhibitor sodium butyrate in the hippocampus kindling model of temporal lobe epilepsy (TLE), a classic model heavily used to approve drugs for treatment of epilepsy. Daily treatment with butyrate significantly inhibited HDAC activity and retarded the development of limbic epileptogenesis without affecting after-discharge signal. HDAC inhibition markedly impaired the persistence of seizure expression many weeks after epilepsy development. Moreover, subchronic HDAC inhibition for 2 weeks resulted in a striking retardation of epileptogenesis. HDAC inhibition, unexpectedly, also showed erasure of the epileptogenic state in epileptic animals. Finally, butyrate-treated animals exhibited a powerful reduction in mossy fiber sprouting, a morphologic index of epileptogenesis. Together these results underscore that HDAC inhibition prevents the development of TLE, indicating HDAC's critical signaling role in epileptogenesis. These findings, therefore, envisage a unique novel therapy for preventing or curing epilepsy by targeting the epigenetic HDAC pathway. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Metformin inhibits age-related centrosome amplification in Drosophila midgut stem cells through AKT/TOR pathway.

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Na, Hyun-Jin; Park, Joung-Sun; Pyo, Jung-Hoon; Jeon, Ho-Jun; Kim, Young-Shin; Arking, Robert; Yoo, Mi-Ae

2015-07-01

We delineated the mechanism regulating the inhibition of centrosome amplification by metformin in Drosophila intestinal stem cells (ISCs). Age-related changes in tissue-resident stem cells may be closely associated with tissue aging and age-related diseases, such as cancer. Centrosome amplification is a hallmark of cancers. Our recent work showed that Drosophila ISCs are an excellent model for stem cell studies evaluating age-related increase in centrosome amplification. Here, we showed that metformin, a recognized anti-cancer drug, inhibits age- and oxidative stress-induced centrosome amplification in ISCs. Furthermore, we revealed that this effect is mediated via down-regulation of AKT/target of rapamycin (TOR) activity, suggesting that metformin prevents centrosome amplification by inhibiting the TOR signaling pathway. Additionally, AKT/TOR signaling hyperactivation and metformin treatment indicated a strong correlation between DNA damage accumulation and centrosome amplification in ISCs, suggesting that DNA damage might mediate centrosome amplification. Our study reveals the beneficial and protective effects of metformin on centrosome amplification via AKT/TOR signaling modulation. We identified a new target for the inhibition of age- and oxidative stress-induced centrosome amplification. We propose that the Drosophila ISCs may be an excellent model system for in vivo studies evaluating the effects of anti-cancer drugs on tissue-resident stem cell aging. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Pharmacological interactions of anti-inflammatory-analgesics in odontology.

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Gómez-Moreno, Gerardo; Guardia, Javier; Cutando, Antonio; Calvo-Guirado, José Luis

2009-02-01

In this second article we describe the more interesting pharmacological interactions in dental practice based on the prescription of analgesic narcotics, paracetamol and non-selective non-steroid anti-inflammatory drugs (NSAI) (which inhibit cyclooxigenase 1 -COX 1- and cyclooxigenase 2 -COX 2-) and selective NSAIs (COX 2 inhibitors). The importance of preventing the appearance of these pharmacological interactions is because these are medicaments prescribed daily in odontology for moderate pain treatment and inflammation in the oral cavity. Paracetamol can interact with warfarin and therefore care should be taken with chronic alcoholic patients. All NSAIs reduce renal blood flow and consequently are capable of reducing the efficacy of medicaments used for treating arterial hypertension, which act via a renal mechanism. Especial attention should be taken considering the risk of interaction between the antagonists of AT1 receptors of angiostensin II (ARAII) and the NSAIs.

Radio-sensitization of WRN helicase deficient cancer cells by targeting homologous recombination pathway

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Gupta, Pooja; Saha, Bhaskar; Patro, Birija Sankar; Chattopadhyay, Subrata

2016-01-01

Ionizing radiation (IR) induced DNA double-strand breaks (DSBs) are primarily repaired by non-homologous end joining (NHEJ). However, it is well established that a subset DSBs which are accumulated in IR-induced G2 phase are dependent on homologous recombination (HR). DNA repair deficient tumor cells have been shown to accumulate high levels of DNA damage. Consequently, these cells become hyperdependent on DNA damage response pathways, including the CHK1-kinase-mediated HR-repair. These observations suggest that DNA repair deficient tumors should exhibit increased radio-sensitivity under HR inhibition. Genetic defects leading to functional loss of werner (WRN) protein is associated with genomic instability and increased cancer incidence. WRN function is known to be abrogated in several human cancer cells due to hypermethylation of CpGisland-promoter and transcriptional silencing of WRN gene. In the current investigation, using isogenic pairs of cell lines differing only in the WRN function, we showed that WRN-deficient cell lines were hyper-radiosensitive to CHK1 pharmacologic inhibition. Here, we found that unrepaired DSB was drastically increased in WRN-deficient cells vis-à-vis WRN-proficient cells in response to IR and CHK1 inhibitor (CHK1i). Our results revealed a marginal role of NHEJ pathway accountable for the radio-sensitivity of WRN-deficient cells. Interestingly, silencing CTIP, a HR protein required for RAD51 loading, significantly abrogated the CHK1i-mediated radiosensitivity in WRN-deficient cells. Silencing of WRN or CTIP individually led to no significant difference in the extent of DNA end resection, as required during HR pathway. Imperatively, our results revealed that WRN and CTIP together play a complementary role in executing DNA end resection during HR-mediated repair of IR induced DSBs. Altogether, our data indicated that inhibition of IR-induced HR pathway at RAD51 loading, but not at DSB end resection, make the WRN-deficient cancer cells

Approaches in studying the pharmacology of Chinese Medicine formulas: bottom-up, top-down-and meeting in the middle.

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Huang, Tao; Zhong, Linda L D; Lin, Chen-Yuan; Zhao, Ling; Ning, Zi-Wan; Hu, Dong-Dong; Zhang, Man; Tian, Ke; Cheng, Chung-Wah; Bian, Zhao-Xiang

2018-01-01

Investigating the pharmacology is key to the modernization of Chinese Medicine (CM) formulas. However, identifying which are the active compound(s) of CM formulas, which biological entities they target, and through which signaling pathway(s) they act to modify disease symptoms, are still difficult tasks for researchers, even when equipped with an arsenal of advanced modern technologies. Multiple approaches, including network pharmacology, pharmaco-genomics, -proteomics, and -metabolomics, have been developed to study the pharmacology of CM formulas. They fall into two general categories in terms of how they tackle a problem: bottom-up and top-down. In this article, we compared these two different approaches in several dimensions by using the case of MaZiRenWan (MZRW, also known as Hemp Seed Pill), a CM herbal formula for functional constipation. Multiple hypotheses are easy to be proposed in the bottom-up approach (e.g. network pharmacology); but these hypotheses are usually false positives and hard to be tested. In contrast, it is hard to suggest hypotheses in the top-down approach (e.g. pharmacometabolomics); however, once a hypothesis is proposed, it is much easier to be tested. Merging of these two approaches could results in a powerful approach, which could be the new paradigm for the pharmacological study of CM formulas.

Perioperative pharmacological management of pulmonary hypertensive crisis during congenital heart surgery.

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Brunner, Nathan; de Jesus Perez, Vinicio A; Richter, Alice; Haddad, François; Denault, André; Rojas, Vanessa; Yuan, Ke; Orcholski, Mark; Liao, Xiaobo

2014-03-01

Pulmonary hypertensive crisis is an important cause of morbidity and mortality in patients with pulmonary arterial hypertension secondary to congenital heart disease (PAH-CHD) who require cardiac surgery. At present, prevention and management of perioperative pulmonary hypertensive crisis is aimed at optimizing cardiopulmonary interactions by targeting prostacyclin, endothelin, and nitric oxide signaling pathways within the pulmonary circulation with various pharmacological agents. This review is aimed at familiarizing the practitioner with the current pharmacological treatment for dealing with perioperative pulmonary hypertensive crisis in PAH-CHD patients. Given the life-threatening complications associated with pulmonary hypertensive crisis, proper perioperative planning can help anticipate cardiopulmonary complications and optimize surgical outcomes in this patient population.

Pharmacological treatment of tics in Gilles de la Tourette Syndrome

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Andrea E. Cavanna

2011-12-01

Full Text Available Tourette syndrome is a neurodevelopmental disorder characterised by the chronic presence of multiple motor tics (e.g. eye blinking, shoulder shrugging, etc. and at least one vocal/phonic tic (e.g. grunting or sniffing. The clinical picture of patients with Tourette syndrome is often complicated by tic-related behavioural problems and associated psychopathology. The pathophysiology of Tourette syndrome is poorly understood, however converging evidence from neuroimaging studies suggests abnormalities within the fronto-striatal pathways. The pharmacological management of the tic symptoms focuses on the dopaminergic and noradrenergic pathways and aims to improve the health-related quality of life of patients.

Soyasaponins can blunt inflammation by inhibiting the reactive oxygen species-mediated activation of PI3K/Akt/NF-kB pathway.

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Zha, Longying; Chen, Jiading; Sun, Suxia; Mao, Limei; Chu, Xinwei; Deng, Hong; Cai, Junwei; Li, Xuefeng; Liu, Zhenqi; Cao, Wenhong

2014-01-01

We and others have recently shown that soyasaponins abundant in soybeans can decrease inflammation by suppressing the nuclear factor kappa B (NF-kB)-mediated inflammation. However, the exact molecular mechanisms by which soyasaponins inhibit the NF-kB pathway have not been established. In this study in macrophages, soyasaponins (A1, A2 and I) inhibited the lipopolysaccharide (LPS)-induced release of inflammatory marker prostaglandin E2 (PGE2) to a similar extent as the NF-kB inhibitor (BAY117082). Soyasaponins (A1, A2 and I) also suppressed the LPS-induced expression of cyclooxygenase 2 (COX-2), another inflammatory marker, in a dose-dependent manner by inhibiting NF-kB activation. In defining the associated mechanisms, we found that soyasaponins (A1, A2 and I) blunted the LPS-induced IKKα/β phosphorylation, IkB phosphorylation and degradation, and NF-kB p65 phosphorylation and nuclear translocation. In studying the upstream targets of soyasaponins on the NF-kB pathway, we found that soyasaponins (A1, A2 and I) suppressed the LPS-induced activation of PI3K/Akt similarly as the PI3K inhibitor LY294002, which alone blocked the LPS-induced activation of NF-kB. Additionally, soyasaponins (A1, A2 and I) reduced the LPS-induced production of reactive oxygen species (ROS) to the same extent as the anti-oxidant N-acetyl-L-cysteine, which alone inhibited the LPS-induced phosphorylation of Akt, IKKα/β, IkBα, and p65, transactivity of NF-kB, PGE2 production, and malondialdehyde production. Finally, our results show that soyasaponins (A1, A2 and I) elevated SOD activity and the GSH/GSSG ratio. Together, these results show that soyasaponins (A1, A2 and I) can blunt inflammation by inhibiting the ROS-mediated activation of the PI3K/Akt/NF-kB pathway.

Cycle Inhibiting Factors (Cifs: Cyclomodulins That Usurp the Ubiquitin-Dependent Degradation Pathway of Host Cells

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Eric Oswald

2011-03-01

Full Text Available Cycle inhibiting factors (Cifs are type III secreted effectors produced by diverse pathogenic bacteria. Cifs are “cyclomodulins” that inhibit the eukaryotic host cell cycle and also hijack other key cellular processes such as those controlling the actin network and apoptosis. This review summarizes current knowledge on Cif since its first characterization in enteropathogenic Escherichia coli, the identification of several xenologues in distant pathogenic bacteria, to its structure elucidation and the recent deciphering of its mode of action. Cif impairs the host ubiquitin proteasome system through deamidation of ubiquitin or the ubiquitin-like protein NEDD8 that regulates Cullin-Ring-ubiquitin Ligase (CRL complexes. The hijacking of the ubiquitin-dependent degradation pathway of host cells results in the modulation of various cellular functions such as epithelium renewal, apoptosis and immune response. Cif is therefore a powerful weapon in the continuous arm race that characterizes host-bacteria interactions.

Exposure to a specific time-varying electromagnetic field inhibits cell proliferation via cAMP and ERK signaling in cancer cells.

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Buckner, Carly A; Buckner, Alison L; Koren, Stan A; Persinger, Michael A; Lafrenie, Robert M

2018-04-01

Exposure to specific electromagnetic field (EMF) patterns can affect a variety of biological systems. We have shown that exposure to Thomas-EMF, a low-intensity, frequency-modulated (25-6 Hz) EMF pattern, inhibited growth and altered cell signaling in malignant cells. Exposure to Thomas-EMF for 1 h/day inhibited the growth of malignant cells including B16-BL6 mouse melanoma cells, MDA-MB-231, MDA-MB-468, BT-20, and MCF-7 human breast cancer and HeLa cervical cancer cells but did not affect non-malignant cells. The Thomas-EMF-dependent changes in cell proliferation were mediated by adenosine 3',5'-cyclic monophosphate (cAMP) and extracellular-signal-regulated kinase (ERK) signaling pathways. Exposure of malignant cells to Thomas-EMF transiently changed the level of cellular cAMP and promoted ERK phosphorylation. Pharmacologic inhibitors (SQ22536) and activators (forskolin) of cAMP production both blocked the ability of Thomas-EMF to inhibit cell proliferation, and an inhibitor of the MAP kinase pathway (PD98059) was able to partially block Thomas-EMF-dependent inhibition of cell proliferation. Genetic modulation of protein kinase A (PKA) in B16-BL6 cells also altered the effect of Thomas-EMF on cell proliferation. Cells transfected with the constitutively active form of PKA (PKA-CA), which interfered with ERK phosphorylation, also interfered with the Thomas-EMF effect on cell proliferation. The non-malignant cells did not show any EMF-dependent changes in cAMP levels, ERK phosphorylation, or cell growth. These data indicate that exposure to the specific Thomas-EMF pattern can inhibit the growth of malignant cells in a manner dependent on contributions from the cAMP and MAP kinase pathways. Bioelectromagnetics. 39;217-230, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Wogonin suppresses melanoma cell B16-F10 invasion and migration by inhibiting Ras-medicated pathways.

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Kai Zhao

Full Text Available The patients diagnosed with melanoma have a bad prognosis for early regional invasion and distant metastases. Wogonin (5,7-dihydroxy-8-methoxyflavone is one of the active components of flavonoids that extracts from Scutellariae radix. Several previous studies reported that wogonin possesses antitumor effect against leukemia, gastrointestinal cancer and breast cancer. In this study, we used melanoma cell B16-F10 to further investigate the anti-invasive and anti-migratory activity of wogonin. Our date showed that wogonin caused suppression of cell migration, adhesion, invasion and actin remodeling by inhibiting the expression of matrix metalloproteinase-2 and Rac1 in vitro. Wogonin also reduced the number of the tumor nodules on the whole surface of the lung in vivo. Furthermore, the examination of mechanism revealed that wogonin inhibited Extracellular Regulated protein Kinases and Protein Kinase B pathways, which are both medicated by Ras. Insulin-like growth factor-1-induced or tumor necrosis factor-α-induced invasion was also inhibited by wogonin. Therefore, the inhibitory mechanism of melanoma cell invasion by wogonin might be elucidated.

Liver X receptor activation inhibits PC-3 prostate cancer cells via the beta-catenin pathway.

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Youlin, Kuang; Li, Zhang; Weiyang, He; Jian, Kang; Siming, Liang; Xin, Gou

2017-03-01

Liver X receptors (LXRs) are nuclear receptors family of ligand-dependent transcription factors that play a crucial role in regulating cholesterol metabolism and inflammation. Recent studies show that LXR agonists exhibit anti-cancer activities in a variety of cancer cell lines including prostate. To further identify the potential mechanisms of LXRα activation on prostate cancer, we investigated the effect of LXR agonist T0901317 on PC3 prostate cancer cell and in which activity of beta-catenin pathway involved. Prostate cancer PC3 cells were transfected with LXR-a siRNA and treated with LXR activator T0901317. qRT-PCR and western blot were used to detect the LXR-a expression. beta-catenin, cyclin D1 and c-MYC were analyzed by western blot. Cell apoptosis was examined by flow cytometry and Cell proliferation was assessed by Cell Counting Kit-8 assay. Cell migration was detected by Transwell chambers. Data showed that T0901317 significantly inhibited PC3 cell proliferation as well as invasion and increased apoptosis in vitro. Furthermore, we found that LXRα activation induced the reduction of beta-catenin expression in PC3 cells, and this inhibitory effect could be totally abolished when cells were treated with LXRα. Meanwhile, the expression of beta-catenin target gene cyclin D1 and c-MYC were also decreased. This study provided additional evidence that LXR activation inhibited PC-3 prostate cancer cells via suppressing beta-catenin pathway. Copyright © 2016 Elsevier GmbH. All rights reserved.

From non-pharmacological treatments for post-traumatic stress disorder to novel therapeutic targets

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Hendriksen, Erik; Olivier, Berend; Oosting, Ronald S

2014-01-01

The development of new pharmacological therapies starts with target discovery. Finding new therapeutic targets for anxiety disorders is a difficult process. Most of the currently described drugs for post-traumatic stress disorder (PTSD) are based on the inhibition of serotonin reuptake. The

Pharmacological modulation of mitochondrial calcium homeostasis.

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Arduino, Daniela M; Perocchi, Fabiana

2018-01-10

Mitochondria are pivotal organelles in calcium (Ca 2+ ) handling and signalling, constituting intracellular checkpoints for numerous processes that are vital for cell life. Alterations in mitochondrial Ca 2+ homeostasis have been linked to a variety of pathological conditions and are critical in the aetiology of several human diseases. Efforts have been taken to harness mitochondrial Ca 2+ transport mechanisms for therapeutic intervention, but pharmacological compounds that direct and selectively modulate mitochondrial Ca 2+ homeostasis are currently lacking. New avenues have, however, emerged with the breakthrough discoveries on the genetic identification of the main players involved in mitochondrial Ca 2+ influx and efflux pathways and with recent hints towards a deep understanding of the function of these molecular systems. Here, we review the current advances in the understanding of the mechanisms and regulation of mitochondrial Ca 2+ homeostasis and its contribution to physiology and human disease. We also introduce and comment on the recent progress towards a systems-level pharmacological targeting of mitochondrial Ca 2+ homeostasis. © 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society.

Physio-pharmacological Investigations About the Anti-inflammatory and Antinociceptive Efficacy of (+)-Limonene Epoxide.

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de Almeida, Antonia Amanda Cardoso; Silva, Renan Oliveira; Nicolau, Lucas Antonio Duarte; de Brito, Tarcísio Vieira; de Sousa, Damião Pergentino; Barbosa, André Luiz Dos Reis; de Freitas, Rivelilson Mendes; Lopes, Luciano da Silva; Medeiros, Jand-Venes Rolim; Ferreira, Paulo Michel Pinheiro

2017-04-01

D-limonene epoxidation generates (+)-limonene epoxide, an understudied compound in the pharmacologically point of view. Herein, we investigated the anti-inflammatory and antinociceptive potentialities of (+)-limonene epoxide and suggested a mechanism of action. The anti-inflammatory potential was analyzed using agents to induce paw edema, permeability, and myeloperoxidase (MPO) activity. Pro-inflammatory cytokines and cell migration of peritoneal cells were also assessed. Antinociceptive effects were evaluated by writhing test induced by acetic acid, formalin, and hot plate assays and contribution of opioid pathways. Pretreated animals with (+)-limonene epoxide showed reduced carrageenan-induced paw edema in all doses (25, 50, and 75 mg/kg) (P Limonene epoxide diminished abdominal contortions induced by acetic acid (78.9%) and paw licking times in both 1 (41.8%) and 2 (51.5%) phases and a pretreatment with naloxone (3 mg/kg) reverted the antinociceptive action in morphine- and (+)-limonene epoxide-treated groups (P limonene epoxide inhibited release/activity of inflammatory mediators, vascular permeability, migration of neutrophils and displayed systemic and peripheral analgesic-dependent effects of the opioid system.

Pharmacological and protein profiling suggest venetoclax (ABT-199) as optimal partner with ibrutinib in chronic lymphocytic leukemia

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Cervantes-Gomez, Fabiola; Lamothe, Betty; Woyach, Jennifer A.; Wierda, William G.; Keating, Michael J.; Balakrishnan, Kumudha; Gandhi, Varsha

2015-01-01

Purpose Bruton’s tyrosine kinase (BTK) is a critical enzyme in the B-cell receptor pathway and is inhibited by ibrutinib due to covalent binding to the kinase domain. Though ibrutinib results in impressive clinical activity in chronic lymphocytic leukemia (CLL), most patients achieve only partial remission due to residual disease. We performed a pharmacologic profiling of residual circulating CLL cells from patients receiving ibrutinib to identify optimal agents that could induce cell death of these lymphocytes. Experimental design Ex vivo serial samples of CLL cells from patients on ibrutinib were obtained prior and after (weeks 2, 4, and 12) the start of treatment. These cells were incubated with PI3K inhibitors (idelalisib or IPI-145), bendamustine, additional ibrutinib, or BCL-2 antagonists (ABT-737 or ABT-199) and cell death was measured. In vitro investigations complemented ex vivo studies. Immunoblots for BTK signaling pathway and antiapoptotic proteins were performed. Results The BCL-2 antagonists, especially ABT-199, induced high cell death during ex vivo incubations. In concert with the ex vivo data, in vitro combinations also resulted highly cytotoxicity. Serial samples of CLL cells obtained before and 2, 4, 12, or 36 weeks after the start of ibrutinib showed inhibition of BTK activity and sensitivity to ABTs. Among the three BCL-2 family anti-apoptotic proteins that are overexpressed in CLL, levels of MCL-1 and BCL-XL were decreased after ibrutinib while ABT-199 selectively antagonizes BCL-2. Conclusions Our biological and molecular results suggest that ibrutinib and ABT-199 combination should be tested clinically against CLL. PMID:25829398

Pharmacological and Protein Profiling Suggests Venetoclax (ABT-199) as Optimal Partner with Ibrutinib in Chronic Lymphocytic Leukemia.

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Cervantes-Gomez, Fabiola; Lamothe, Betty; Woyach, Jennifer A; Wierda, William G; Keating, Michael J; Balakrishnan, Kumudha; Gandhi, Varsha

2015-08-15

Bruton's tyrosine kinase (BTK) is a critical enzyme in the B-cell receptor pathway and is inhibited by ibrutinib due to covalent binding to the kinase domain. Though ibrutinib results in impressive clinical activity in chronic lymphocytic leukemia (CLL), most patients achieve only partial remission due to residual disease. We performed a pharmacologic profiling of residual circulating CLL cells from patients receiving ibrutinib to identify optimal agents that could induce cell death of these lymphocytes. Ex vivo serial samples of CLL cells from patients on ibrutinib were obtained prior and after (weeks 2, 4, and 12) the start of treatment. These cells were incubated with PI3K inhibitors (idelalisib or IPI-145), bendamustine, additional ibrutinib, or BCL-2 antagonists (ABT-737 or ABT-199), and cell death was measured. In vitro investigations complemented ex vivo studies. Immunoblots for BTK signaling pathway and antiapoptotic proteins were performed. The BCL-2 antagonists, especially ABT-199, induced high cell death during ex vivo incubations. In concert with the ex vivo data, in vitro combinations also resulted in high cytotoxicity. Serial samples of CLL cells obtained before and 2, 4, 12, or 36 weeks after the start of ibrutinib showed inhibition of BTK activity and sensitivity to ABTs. Among the three BCL-2 family antiapoptotic proteins that are overexpressed in CLL, levels of MCL-1 and BCL-XL were decreased after ibrutinib while ABT-199 selectively antagonizes BCL-2. Our biologic and molecular results suggest that ibrutinib and ABT-199 combination should be tested clinically against CLL. ©2015 American Association for Cancer Research.

Arctigenin inhibits lipopolysaccharide-induced iNOS expression in RAW264.7 cells through suppressing JAK-STAT signal pathway.

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Kou, Xianjuan; Qi, Shimei; Dai, Wuxing; Luo, Lan; Yin, Zhimin

2011-08-01

Arctigenin has been demonstrated to have an anti-inflammatory function, but the precise mechanisms of its action remain to be fully defined. In the present study, we determined the effects of arctigenin on lipopolysaccharide (LPS)-induced production of proinflammatory mediators and the underlying mechanisms involved in RAW264.7 cells. Our results indicated that arctigenin exerted its anti-inflammatory effect by inhibiting ROS-dependent STAT signaling through its antioxidant activity. Arctigenin also significantly reduced the phosphorylation of STAT1 and STAT 3 as well as JAK2 in LPS-stimulated RAW264.7 cells. The inhibitions of STAT1 and STAT 3 by arctigenin prevented their translocation to the nucleus and consequently inhibited expression of iNOS, thereby suppressing the expression of inflammation-associated genes, such as IL-1β, IL-6 and MCP-1, whose promoters contain STAT-binding elements. However, COX-2 expression was slightly inhibited at higher drug concentrations (50 μM). Our data demonstrate that arctigenin inhibits iNOS expression via suppressing JAK-STAT signaling pathway in macrophages. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Urotensin II inhibits skeletal muscle glucose transport signaling pathways via the NADPH oxidase pathway.

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Hong-Xia Wang

Full Text Available Our previous studies have demonstrated that the urotensin (UII and its receptor are up-regulated in the skeletal muscle of mice with type II diabetes mellitus (T2DM, but the significance of UII in skeletal muscle insulin resistance remains unknown. The purpose of this study was to investigate the effect of UII on NADPH oxidase and glucose transport signaling pathways in the skeletal muscle of mice with T2DM and in C2C12 mouse myotube cells. KK/upj-AY/J mice (KK mice were divided into the following groups: KK group, with saline treatment for 2 weeks; KK+ urantide group, with daily 30 µg/kg body weight injections over the same time period of urantide, a potent urotensin II antagonist peptide; Non-diabetic C57BL/6J mice were used as normal controls. After urantide treatment, mice were subjected to an intraperitoneal glucose tolerance test, in addition to measurements of the levels of ROS, NADPH oxidase and the phosphorylated AKT, PKC and ERK. C2C12 cells were incubated with serum-free DMEM for 24 hours before conducting the experiments, and then administrated with 100 nM UII for 2 hours or 24 hours. Urantide treatment improved glucose tolerance, decreased the translocation of the NADPH subunits p40-phox and p47-phox, and increased levels of the phosphorylated PKC, AKT and ERK. In contrast, UII treatment increased ROS production and p47-phox and p67-phox translocation, and decreased the phosphorylated AKT, ERK1/2 and p38MAPK; Apocynin abrogated this effect. In conclusion, UII increased ROS production by NADPH oxidase, leading to the inhibition of signaling pathways involving glucose transport, such as AKT/PKC/ERK. Our data imply a role for UII at the molecular level in glucose homeostasis, and possibly in skeletal muscle insulin resistance in T2DM.

Identification of small molecule compounds that inhibit the HIF-1 signaling pathway

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Sun Yi

2009-12-01

Full Text Available Abstract Background Hypoxia-inducible factor-1 (HIF-1 is the major hypoxia-regulated transcription factor that regulates cellular responses to low oxygen environments. HIF-1 is composed of two subunits: hypoxia-inducible HIF-1α and constitutively-expressed HIF-1β. During hypoxic conditions, HIF-1α heterodimerizes with HIF-1β and translocates to the nucleus where the HIF-1 complex binds to the hypoxia-response element (HRE and activates expression of target genes implicated in cell growth and survival. HIF-1α protein expression is elevated in many solid tumors, including those of the cervix and brain, where cells that are the greatest distance from blood vessels, and therefore the most hypoxic, express the highest levels of HIF-1α. Therapeutic blockade of the HIF-1 signaling pathway in cancer cells therefore provides an attractive strategy for development of anticancer drugs. To identify small molecule inhibitors of the HIF-1 pathway, we have developed a cell-based reporter gene assay and screened a large compound library by using a quantitative high-throughput screening (qHTS approach. Results The assay is based upon a β-lactamase reporter under the control of a HRE. We have screened approximate 73,000 compounds by qHTS, with each compound tested over a range of seven to fifteen concentrations. After qHTS we have rapidly identified three novel structural series of HIF-1 pathway Inhibitors. Selected compounds in these series were also confirmed as inhibitors in a HRE β-lactamase reporter gene assay induced by low oxygen and in a VEGF secretion assay. Three of the four selected compounds tested showed significant inhibition of hypoxia-induced HIF-1α accumulation by western blot analysis. Conclusion The use of β-lactamase reporter gene assays, in combination with qHTS, enabled the rapid identification and prioritization of inhibitors specific to the hypoxia induced signaling pathway.

cGMP-Phosphodiesterase Inhibition Prevents Hypoxia-Induced Cell Death Activation in Porcine Retinal Explants.

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Lorena Olivares-González

Full Text Available Retinal hypoxia and oxidative stress are involved in several retinal degenerations including diabetic retinopathy, glaucoma, central retinal artery occlusion, or retinopathy of prematurity. The second messenger cyclic guanosine monophosphate (cGMP has been reported to be protective for neuronal cells under several pathological conditions including ischemia/hypoxia. The purpose of this study was to evaluate whether the accumulation of cGMP through the pharmacological inhibition of phosphodiesterase (PDE with Zaprinast prevented retinal degeneration induced by mild hypoxia in cultures of porcine retina. Exposure to mild hypoxia (5% O2 for 24h reduced cGMP content and induced retinal degeneration by caspase dependent and independent (PARP activation mechanisms. Hypoxia also produced a redox imbalance reducing antioxidant response (superoxide dismutase and catalase activities and increasing superoxide free radical release. Zaprinast reduced mild hypoxia-induced cell death through inhibition of caspase-3 or PARP activation depending on the cell layer. PDE inhibition also ameliorated the effects of mild hypoxia on antioxidant response and the release of superoxide radical in the photoreceptor layer. The use of a PKG inhibitor, KT5823, suggested that cGMP-PKG pathway is involved in cell survival and antioxidant response. The inhibition of PDE, therefore, could be useful for reducing retinal degeneration under hypoxic/ischemic conditions.

Fucosterol activates the insulin signaling pathway in insulin resistant HepG2 cells via inhibiting PTP1B.

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Jung, Hyun Ah; Bhakta, Himanshu Kumar; Min, Byung-Sun; Choi, Jae Sue

2016-10-01

Insulin resistance is a characteristic feature of type 2 diabetes mellitus (T2DM) and is characterized by defects in insulin signaling. This study investigated the modulatory effects of fucosterol on the insulin signaling pathway in insulin-resistant HepG2 cells by inhibiting protein tyrosine phosphatase 1B (PTP1B). In addition, molecular docking simulation studies were performed to predict binding energies, the specific binding site of fucosterol to PTP1B, and to identify interacting residues using Autodock 4.2 software. Glucose uptake was determined using a fluorescent D-glucose analogue and the glucose tracer 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxyglucose, and the signaling pathway was detected by Western blot analysis. We found that fucosterol enhanced insulin-provoked glucose uptake and conjointly decreased PTP1B expression level in insulin-resistant HepG2 cells. Moreover, fucosterol significantly reduced insulin-stimulated serine (Ser307) phosphorylation of insulin receptor substrate 1 (IRS1) and increased phosphorylation of Akt, phosphatidylinositol-3-kinase, and extracellular signal- regulated kinase 1 at concentrations of 12.5, 25, and 50 µM in insulin-resistant HepG2 cells. Fucosterol inhibited caspase-3 activation and nuclear factor kappa B in insulin-resistant hepatocytes. These results suggest that fucosterol stimulates glucose uptake and improves insulin resistance by downregulating expression of PTP1B and activating the insulin signaling pathway. Thus, fucosterol has potential for development as an anti-diabetic agent.

Intra-amniotic pharmacological blockade of inflammatory signalling pathways in an ovine chorioamnionitis model.

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Ireland, D J; Kemp, M W; Miura, Y; Saito, M; Newnham, J P; Keelan, J A

2015-05-01

Intrauterine inflammation (IUI) associated with infection is the major cause of preterm birth (PTB) at PTBs. Pharmacological strategies to prevent PTB and improve fetal outcomes will likely require both antimicrobial and anti-inflammatory therapies. Here we investigated the effects of two cytokine-suppressive anti-inflammatory drugs (CSAIDs), compounds that specifically target inflammatory signalling pathways, in an ovine model of lipopolysaccharide (LPS)-induced chorioamnionitis. Chronically catheterized ewes at 116 days gestation (n = 7/group) received an intra-amniotic (IA) bolus of LPS (10 mg) plus vehicle or CSAIDS: TPCA-1 (1.2 mg/kg fetal weight) or 5z-7-oxozeaenol (OxZnl; 0.4 mg/kg fetal weight); controls received vehicle (dimethylsulphoxide). Amniotic fluid (AF), fetal and maternal blood samples were taken 0, 2, 6, 12, 24 and 48 h later; tissues were taken at autopsy (48 h). Administration of TPCA-1 or OxZnl abrogated the stimulatory effects of LPS (P < 0.01 versus vehicle control) on production of PGE2 in AF, with lesser (non-significant) effects on IL-6 production. Fetal membrane polymorphonuclear cell infiltration score was significantly higher in LPS versus vehicle control animals (P < 0.01), and this difference was absent with TPCA-1 and OxZnl treatment. LPS-induced systemic fetal inflammation was highly variable, with no significant effects of CSAIDs observed. Lung inflammation was evident with LPS exposure, but unaffected by CSAID treatment. We have shown in a large animal model that IA administration of a single dose of CSAIDs can suppress LPS-induced IA inflammatory responses, while fetal effects were minimal. Further development and investigation of these compounds in infectious models is warranted. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Knockdown of long non-coding RNA Taurine Up-Regulated 1 inhibited doxorubicin resistance of bladder urothelial carcinoma via Wnt/β-catenin pathway.

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Xie, Dalong; Zhang, Hui; Hu, Xuanhao; Shang, Chao

2017-10-24

In genitourinary system, bladder cancer (BC) is the most common and lethal malignant tumor, which most common type is bladder urothelial carcinoma (BUC). Long non-coding RNA (lncRNA) Taurine Up-Regulated 1 (TUG1) gene is high-expressed in several malignant tumors, including BC. In this study, over-expression of TUG1 was found in BUC tissues and cell line resistant to doxorubicin (Dox). Knockdown of TUG1 inhibited the Dox resistance and promoted the cytotoxicity induced by Dox in T24/Dox cells. TUG1 knockdown also depressed the Wnt/β-catenin pathway, and the activation the Wnt/β-catenin pathway partly reversed the inhibitory effects of TUG1 knockdown on Dox resistance in T24/Dox cells. In conclusion, up-regulation of lncRNA TUG1 was related with the poor response of BUC patients to Dox chemotherapy, knockdown of TUG1 inhibited the Dox resistance of BUC cells via Wnt/β-catenin pathway. These findings might assist in the discovery of novel potential diagnostic and therapeutic target for BUC, thereby improve the effects of clinical treatment in patients.

miR-339-5p inhibits alcohol-induced brain inflammation through regulating NF-κB pathway

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Zhang, Yu; Wei, Guangkuan; Di, Zhiyong; Zhao, Qingjie

2014-01-01

Graphical abstract: - Highlights: • Alcohol upregulates miR-339-5p expression. • miR-339-5p inhibits the NF-kB pathway. • miR-339-5p interacts with and blocks activity of IKK-beat and IKK-epsilon. • miR-339-5p modulates IL-1β, IL-6 and TNF-α. - Abstract: Alcohol-induced neuroinflammation is mediated by the innate immunesystem. Pro-inflammatory responses to alcohol are modulated by miRNAs. The miRNA miR-339-5p has previously been found to be upregulated in alcohol-induced neuroinflammation. However, little has been elucidated on the regulatory functions of this miRNA in alcohol-induced neuroinflammation. We investigated the function of miR-339-5p in alcohol exposed brain tissue and isolated microglial cells using ex vivo and in vitro techniques. Our results show that alcohol induces transcription of miR 339-5p, IL-6, IL-1β and TNF-α in mouse brain tissue and isolated microglial cells by activating NF-κB. Alcohol activation of NF-κB allows for nuclear translocation of the NF-κB subunit p65 and expression of pro-inflammatory mediators. miR-339-5p inhibited expression of these pro-inflammatory factors through the NF-κB pathway by abolishing IKK-β and IKK-ε activity

miR-339-5p inhibits alcohol-induced brain inflammation through regulating NF-κB pathway

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Zhang, Yu [Department of Neurology, The First Affiliated School of Harbin Medical University, Harbin 150001 (China); Wei, Guangkuan [Department of Neurology, Heilongjiang Provincial Hospital, Harbin 150036 (China); Di, Zhiyong [Department of Laboratory, Heilongjiang Provincial Hospital, Harbin 150036 (China); Zhao, Qingjie, E-mail: zhaoqingjie2013@163.com [Department of Neurology, The First Affiliated School of Harbin Medical University, Harbin 150001 (China)

2014-09-26

Graphical abstract: - Highlights: • Alcohol upregulates miR-339-5p expression. • miR-339-5p inhibits the NF-kB pathway. • miR-339-5p interacts with and blocks activity of IKK-beat and IKK-epsilon. • miR-339-5p modulates IL-1β, IL-6 and TNF-α. - Abstract: Alcohol-induced neuroinflammation is mediated by the innate immunesystem. Pro-inflammatory responses to alcohol are modulated by miRNAs. The miRNA miR-339-5p has previously been found to be upregulated in alcohol-induced neuroinflammation. However, little has been elucidated on the regulatory functions of this miRNA in alcohol-induced neuroinflammation. We investigated the function of miR-339-5p in alcohol exposed brain tissue and isolated microglial cells using ex vivo and in vitro techniques. Our results show that alcohol induces transcription of miR 339-5p, IL-6, IL-1β and TNF-α in mouse brain tissue and isolated microglial cells by activating NF-κB. Alcohol activation of NF-κB allows for nuclear translocation of the NF-κB subunit p65 and expression of pro-inflammatory mediators. miR-339-5p inhibited expression of these pro-inflammatory factors through the NF-κB pathway by abolishing IKK-β and IKK-ε activity.

Parathyroid hormone inhibition of Na{sup +}/H{sup +} exchanger 3 transcription: Intracellular signaling pathways and transcription factor expression

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Neri, Elida Adalgisa; Bezerra, Camila Nogueira Alves, E-mail: camilab@icb.usp.br; Queiroz-Leite, Gabriella Duarte; Polidoro, Juliano Zequini; Rebouças, Nancy Amaral

2015-06-12

The main transport mechanism of reabsorption of sodium bicarbonate and fluid in the renal proximal tubules involves Na{sup +}/H{sup +} exchanger 3 (NHE3), which is acutely and chronically downregulated by parathyroid hormone (PTH). Although PTH is known to exert an inhibitory effect on NHE3 expression and transcription, the molecular mechanisms involved remain unclear. Here, we demonstrated that, in opossum kidney proximal tubule (OKP) cells, PTH-induced inhibition of Nhe3 gene promoter occurs even in the core promoter that controls expression of the reporter gene. We found that inhibition of the protein kinase A (PKA) and Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathways transformed PTH from an inhibitor of promoter activity into an activator of that same activity, as did point mutations in the EGR1, Sp1, and Sp3 binding consensus elements in the promoter. In nuclear extracts of PTH-treated OKP cells, we also observed increased expression of EGR1 mRNA and of some Sp3 isoforms. Electrophoretic mobility shift assay showed a supershift of the −61 to −42-bp probe with an anti-EGR1 antibody in PTH-treated cells, suggesting that EGR1 binding is relevant for the inhibitory activity of PTH. We conclude that PTH-induced inhibition of NHE3 transcription is related to higher EGR1 expression; to EGR1 binding to the proximal and core promoters; and to PKA and JAK/STAT pathway activation. This mechanism might be responsible, at least in part, for lower NHE3 expression and sodium reabsorption in renal proximal tubules in the presence of high PTH levels. - Highlights: • PTH regulation of Nhe3 promoter depends on EGR1 binding. • EGR1, PKA and JAK/STAT are involved in PTH inhibition of the Nhe3 promoter. • PTH alters expression of EGR1 and Sp3. • PTH inhibits the Nhe3 promoter by regulating PKA and JAK/STAT signaling.

Understanding and Targeting Tumor Microenvironment in Prostate Cancer to Inhibit Tumor Progression and Castration Resistance

Science.gov (United States)

2016-10-01

cancer-secreted chemokine to attract Cxcr2-expressing MDSCs and, correspondingly, pharmacological inhibition of Cxcr2 impeded tumor progression...impact of pharmacological inhibition of Cxcl5 and Cxcr2 on MDSCs using the transwell migration assay 26 . First, anti-Cxcl5 neutralizing antibody...and MRI . (B) Generation of the CPPSML chimera model. (C) Fluorescence microscopy and H&E image of snap frozen prostate tumor from chimera showing that

Pharmacological modulation of human platelet leukotriene C4-synthase.

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Sala, A; Folco, G; Henson, P M; Murphy, R C

1997-03-21

The aim of this study was to test if human platelet leukotriene C4-synthase (LTC4-S) is pharmacologically different from cloned and expressed LTC4-S and, in light of the significant homologies between 5-lipoxygenase activating protein (FLAP) and LTC4-S, if different potencies of leukotriene synthesis inhibitors acting through binding with FLAP (FLAP inhibitors) reflect in different potencies as LTC4-S inhibitors. Leukotriene C4 (LTC4) synthesis by washed human platelets supplemented with synthetic leukotriene A4 (LTA4) was studied in the absence and presence of two different, structurally unrelated FLAP inhibitors (MK-886 and BAY-X1005) as well as a direct 5-lipoxygenase inhibitor (zileuton). LTC4 production was analyzed by RP-HPLC coupled to diode array detection. We report that human platelet LTC4-S was inhibited by MK-886 and BAY-X1005 (IC50 of 4.7 microM and 91.2 microM, respectively), but not by zileuton (inactive up to 300 microM); all 3 compounds were able to inhibit 5-lipoxygenase metabolite biosynthesis in intact human polymorphonuclear leukocytes (IC50 of 0.044 microM, 0.85 microM, and 1.5 microM, respectively). Platelet LTC4-S does not appear pharmacologically different from expression cloned LTC4-S. LTC4-S inhibition by FLAP inhibitors is in agreement with the significant homology reported for expression-cloned LTC4-S with FLAP, Furthermore, functional homology of the binding sites for inhibitors on LTC4-S and FLAP is suggested by the conservation of the relative potencies of MK-886 and BAY-X1005 vs FLAP-dependent 5-lipoxygenase activity and LTC4-S inhibition: MK-886 was 19.3-fold more potent than BAY-X1005 as FLAP inhibitor and 19.6-fold more potent than BAY-X1005 as LTC4-S inhibitor.

Methylcobalamin promotes proliferation and migration and inhibits apoptosis of C2C12 cells via the Erk1/2 signaling pathway

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Okamoto, Michio [Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Tanaka, Hiroyuki, E-mail: tanahiro-osk@umin.ac.jp [Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Okada, Kiyoshi [Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kuroda, Yusuke [Department of Orthopaedic Surgery, Kansai Rosai Hospital, 3-1-69 Inabaso, Amagasaki, Hyogo 660-8511 (Japan); Nishimoto, Shunsuke; Murase, Tsuyoshi; Yoshikawa, Hideki [Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2014-01-17

Highlights: •Methylcobalamin activated the Erk1/2 signaling pathway in C2C12 cells. •Methylcobalamin promoted the proliferation and migration in C2C12 cells. •C2C12 cell apoptosis during differentiation was inhibited by methylcobalamin. -- Abstract: Methylcobalamin (MeCbl) is a vitamin B12 analog that has some positive effects on peripheral nervous disorders. Although some previous studies revealed the effects of MeCbl on neurons, its effect on the muscle, which is the final target of motoneuron axons, remains to be elucidated. This study aimed to determine the effect of MeCbl on the muscle. We found that MeCbl promoted the proliferation and migration of C2C12 myoblasts in vitro and that these effects are mediated by the Erk1/2 signaling pathway without affecting the activity of the Akt signaling pathway. We also demonstrated that MeCbl inhibits C2C12 cell apoptosis during differentiation. Our results suggest that MeCbl has beneficial effects on the muscle in vitro. MeCbl administration may provide a novel therapeutic approach for muscle injury or degenerating muscle after denervation.

A potent complement factor C3 specific nanobody inhibiting multiple functions in the alternative pathway of human and murine complement.

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Jensen, Rasmus K; Pihl, Rasmus; Gadeberg, Trine A F; Jensen, Jan K; Andersen, Kasper R; Thiel, Steffen; Laursen, Nick S; Andersen, Gregers Rom

2018-03-01

The complement system is a complex, carefully regulated proteolytic cascade for which suppression of aberrant activation is of increasing clinical relevance and inhibition of the complement alternative pathway is a subject of intense research. Here, we describe the nanobody hC3Nb1 that binds to multiple functional states of C3 with sub-nanomolar affinity. The nanobody causes a complete shutdown of alternative pathway activity in human and murine serum when present in concentrations comparable to C3, and hC3Nb1 is shown to prevent both proconvertase assembly as well as binding of the C3 substrate to C3 convertases. Our crystal structure of the C3b-hC3Nb1 complex and functional experiments demonstrate that proconvertase formation is blocked by steric hindrance between the nanobody and an Asn-linked glycan on complement factor B. In addition, hC3Nb1 is shown to prevent factor H binding to C3b rationalizing its inhibition of factor I activity. Our results identify hC3Nb1 as a versatile, inexpensive, and powerful inhibitor of the alternative pathway in both human and murine in vitro model systems of complement activation. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Pharmacological inhibition of heparin-binding EGF-like growth factor promotes peritoneal angiogenesis in a peritoneal dialysis rat model.

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Li, Zhenyuan; Yan, Hao; Yuan, Jiangzi; Cao, Liou; Lin, Aiwu; Dai, Huili; Ni, Zhaohui; Qian, Jiaqi; Fang, Wei

2018-04-01

Molecular mechanisms of peritoneal dialysis (PD) ultrafiltration failure, peritoneal neo-angiogenesis, and fibrosis remain to be determined. We aimed to determine the role of heparin-binding EGF-like growth factor (HB-EGF) inhibition on angiogenesis of peritoneal membrane in a PD rat model. 32 male Wistar rats were assigned into (1) control group; (2) uremic non-PD group: subtotal nephrectomy-induced uremic rats without PD; (3) uremic rats subjected to PD: uremic rats that were dialyzed with Dianeal ® for 4 weeks; (4) CRM 197 group: dialyzed uremic rats were supplemented with CRM197, a specific HB-EGF inhibitor. Peritoneal transport function was examined by peritoneal equilibration test. Expression of HB-EGF and EGFR in peritoneal samples were examined by real-time PCR, immunohistochemical staining, and western blot. Progressive angiogenesis and fibrosis were observed in uremic PD rats, and there were associated with decreased net ultrafiltration (nUF), increased permeability of peritoneal membrane, and reduced expression of HB-EGF and EGFR protein and mRNA in uremic PD rats compared to uremic non-PD or control groups (both p CRM197 significantly induced peritoneal membrane permeability, decreased nUF, increased higher vessel density, and reduced pericyte count compared to that of uremic PD rats. The levels of HB-EGF and EGFR expression negatively correlated with vessel density in peritoneal membrane (both p < 0.001). PD therapy was associated with peritoneal angiogenesis, functional deterioration, and downregulation of HB-EGF/EGFR. Pharmacological inhibition of HB-EGF promoted PD-induced peritoneal angiogenesis and fibrosis and ultrafiltration decline, suggesting that HB-EGF downregulation contributes to peritoneal functional deterioration in the uremic PD rat model.

AOPPs Induce MCP-1 Expression by Increasing ROS-Mediated Activation of the NF-κB Pathway in Rat Mesangial Cells: Inhibition by Sesquiterpene Lactones

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Jian-Cheng Wang

2013-12-01

Full Text Available Background: Monocyte chemoattractant protein-1 (MCP-1 plays an important role in extracellular matrix accumulation through macrophage recruitment and activation in the development and progression of diabetic nephropathy. Therefore, this study examined whether advanced oxidation protein products (AOPPs are involved in nuclear factor-κB (NF-κB activation and MCP-1 mRNA and protein expression in mesangial cells (MCs and evaluated the effects of derivatives of sesquiterpene lactones (SLs on AOPP-induced renal damage. Methods: MCP-1 mRNA and protein expression in MCs were determined by quantitative real-time PCR and ELISA, respectively. The level of intracellular reactive oxygen species (ROS was determined by flow cytometry. The protein expression of tubulin, P47, NF-κB p65, phospho-NF-κB p65, IκB, phospho-IκB, IKKß and phospho-IKKß was evaluated by Western blot. Results: AOPPs caused oxidative stress in MCs and activated the NF-κB pathway by inducing IκBa phosphorylation and degradation. Inhibition of ROS by SOD (ROS inhibitor blocked the AOPP-mediated NF-κB pathway. Moreover, the inhibition of AOPP-induced overproduction of MCP-1 mRNA and protein was associated with inhibition of IκBa degradation by SLs. Conclusion: AOPPs induce MCP-1 expression by activating the ROS/NF-κB pathway and can be inhibited by SLs. These findings may provide a novel approach to treat inflammatory and immune renal diseases, including diabetic nephropathy.

Saponin Inhibits Hepatitis C Virus Propagation by Up-regulating Suppressor of Cytokine Signaling 2

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Kang, Sang-Min; Min, Saehong; Son, Kidong; Lee, Han Sol; Park, Eun Mee; Ngo, Huong T. T.; Tran, Huong T. L.; Lim, Yun-Sook; Hwang, Soon B.

2012-01-01

Saponins are a group of naturally occurring plant glycosides which possess a wide range of pharmacological properties, including anti-tumorigenic and antiviral activities. To investigate whether saponin has anti-hepatitis C virus (HCV) activity, we examined the effect of saponin on HCV replication. HCV replication was efficiently inhibited at a concentration of 10 µg/ml of saponin in cell culture grown HCV (HCVcc)-infected cells. Inhibitory effect of saponin on HCV replication was verified by quantitative real-time PCR, reporter assay, and immunoblot analysis. In addition, saponin potentiated IFN-α-induced anti-HCV activity. Moreover, saponin exerted antiviral activity even in IFN-α resistant mutant HCVcc-infected cells. To investigate how cellular genes were regulated by saponin, we performed microarray analysis using HCVcc-infected cells. We demonstrated that suppressor of cytokine signaling 2 (SOCS2) protein level was distinctively increased by saponin, which in turn resulted in inhibition of HCV replication. We further showed that silencing of SOCS2 resurrected HCV replication and overexpression of SOCS2 suppressed HCV replication. These data imply that saponin inhibits HCV replication via SOCS2 signaling pathway. These findings suggest that saponin may be a potent therapeutic agent for HCV patients. PMID:22745742

Long non-coding RNA MEG3 inhibits the proliferation and metastasis of oral squamous cell carcinoma by regulating the WNT/β-catenin signaling pathway.

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Liu, Zongxiang; Wu, Cui; Xie, Nina; Wang, Penglai

2017-10-01

This study aimed to investigate how long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3) inhibits the growth and metastasis of oral squamous cell carcinoma (OSCC) by regulating WNT/β-catenin signaling pathway in order to explore the antitumor effect of MEG3 and to provide a potential molecular target for the treatment of OSCC. The RT-qPCR technique was used to quantitatively analyze the expression of MEG3 in cancer and adjacent tissues collected from the patients after surgery. Using the Lipofectamine method, the MEG3 overexpression vector and the siRNA interference vector were constructed and transfected into SCC15 and Cal27 cells, respectively, followed by cell proliferation, apoptosis and metastasis analyses. The semi-quantitative analysis of the expression of the β-catenin protein in transfected cells was performed by the western blot analysis, and the activity of the WNT/β-catenin signaling pathway was analyzed using the TOP/FOP flash reporters. In addition, the cells were treated with decitabine to investigate the correlation between the MEG3 expression and the DNA methylation. Results showed that the expression level of MEG3 was significantly decreased in OSCC (psuppressor by inhibiting the WNT/β-catenin signaling pathway. In addition, the expression of the MEG3 was significantly affected by the degree of DNA methylation. It was concluded that the lncRNA MEG3 can inhibit the growth and metastasis of OSCC by negatively regulating the WNT/β-catenin signaling pathway.

Inhibition of multiple pathogenic pathways by histone deacetylase inhibitor SAHA in a corneal alkali-burn injury model

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Li, Xinyu; Zhou, Qinbo; Hanus, Jakub; Anderson, Chastain; Zhang, Hongmei; Dellinger, Michael; Brekken, Rolf; Wang, Shusheng

2013-01-01

Neovascularization (NV) in the cornea is a major cause of vision impairment and corneal blindness. Hemangiogenesis and lymphangiogenesis induced by inflammation underlie the pathogenesis of corneal NV. The current mainstay treatment, corticosteroid, treats the inflammation associated with corneal NV, but is not satisfactory due to such side effects as cataract and the increase in intraocular pressure. It is imperative to develop a novel therapy that specifically targets the hemangiogenesis, lymphangiogenesis and inflammation pathways underlying corneal NV. Histone deacetylase inhibitors (HDACi) have been in clinical trials for cancer and other diseases. In particular, HDACi suberoylanilide hydroxamic acid (SAHA, vorinostat, Zolinza) has been approved by the FDA for the treatment of cutaneous T-cell lymphoma. The functional mechanism of SAHA in cancer and especially in corneal NV remains unclear. Here, we show that topical application of SAHA inhibits neovascularization in an alkali-burn corneal injury model. Mechanistically, SAHA inhibits corneal NV by repressing hemangiogenesis, inflammation pathways and previously overlooked lymphangiogenesis. Topical SAHA is well tolerated on the ocular surface. In addition, the potency of SAHA in corneal NV appears to be comparable to the current steroid therapy. SAHA may possess promising therapeutic potential in alkali-burn corneal injury and other inflammatory neovascularization disorders. PMID:23186311

Hibiscus sabdariffa Leaf Extract Inhibits Human Prostate Cancer Cell Invasion via Down-Regulation of Akt/NF-κB/MMP-9 Pathway

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Chiu, Chun-Tang; Chen, Jing-Hsien; Chou, Fen-Pi; Lin, Hui-Hsuan

2015-01-01

Hibiscus sabdariffa leaf has been previously shown to possess hypoglycemic, hypolipidemic, and antioxidant effects, and induce tumor cell apoptosis. However, the molecular mechanisms involved in the anticancer activity of H. sabdariffa leaf extract (HLE) are poorly understood. The object of the study was to examine the anti-invasive potential of HLE. First, HLE was demonstrated to be rich in polyphenols. The results of wound-healing assay and in vitro transwell assay revealed that HLE dose-dependently inhibited the migration and invasion of human prostate cancer LNCaP (lymph node carcinoma of the prostate) cells under non-cytotoxic concentrations. Our results further showed that HLE exerted an inhibitory effect on the activity and expressions of matrix metalloproteinase-9 (MMP-9). The HLE-inhibited MMP-9 expression appeared to be a consequence of nuclear factor-kappaB (NF-κB) inactivation because its DNA-binding activity was suppressed by HLE. Molecular data showed all these influences of HLE might be mediated via inhibition of protein kinase B (PKB, also known as Akt)/NF-κB/MMP-9 cascade pathway, as demonstrated by the transfection of Akt1 overexpression vector. Finally, the inhibitory effect of HLE was proven by its inhibition on the growth of LNCaP cells and the expressions of metastasis-related molecular proteins in vivo. These findings suggested that the inhibition of MMP-9 expression by HLE may act through the suppression of the Akt/NF-κB signaling pathway, which in turn led to the reduced invasiveness of the cancer cells. PMID:26115086

Hibiscus sabdariffa Leaf Extract Inhibits Human Prostate Cancer Cell Invasion via Down-Regulation of Akt/NF-kB/MMP-9 Pathway.

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Chiu, Chun-Tang; Chen, Jing-Hsien; Chou, Fen-Pi; Lin, Hui-Hsuan

2015-06-24

Hibiscus sabdariffa leaf has been previously shown to possess hypoglycemic, hypolipidemic, and antioxidant effects, and induce tumor cell apoptosis. However, the molecular mechanisms involved in the anticancer activity of H. sabdariffa leaf extract (HLE) are poorly understood. The object of the study was to examine the anti-invasive potential of HLE. First, HLE was demonstrated to be rich in polyphenols. The results of wound-healing assay and in vitro transwell assay revealed that HLE dose-dependently inhibited the migration and invasion of human prostate cancer LNCaP (lymph node carcinoma of the prostate) cells under non-cytotoxic concentrations. Our results further showed that HLE exerted an inhibitory effect on the activity and expressions of matrix metalloproteinase-9 (MMP-9). The HLE-inhibited MMP-9 expression appeared to be a consequence of nuclear factor-kappaB (NF-κB) inactivation because its DNA-binding activity was suppressed by HLE. Molecular data showed all these influences of HLE might be mediated via inhibition of protein kinase B (PKB, also known as Akt)/NF-kB/MMP-9 cascade pathway, as demonstrated by the transfection of Akt1 overexpression vector. Finally, the inhibitory effect of HLE was proven by its inhibition on the growth of LNCaP cells and the expressions of metastasis-related molecular proteins in vivo. These findings suggested that the inhibition of MMP-9 expression by HLE may act through the suppression of the Akt/NF-kB signaling pathway, which in turn led to the reduced invasiveness of the cancer cells.

A gene expression signature of RAS pathway dependence predicts response to PI3K and RAS pathway inhibitors and expands the population of RAS pathway activated tumors.

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Loboda, Andrey; Nebozhyn, Michael; Klinghoffer, Rich; Frazier, Jason; Chastain, Michael; Arthur, William; Roberts, Brian; Zhang, Theresa; Chenard, Melissa; Haines, Brian; Andersen, Jannik; Nagashima, Kumiko; Paweletz, Cloud; Lynch, Bethany; Feldman, Igor; Dai, Hongyue; Huang, Pearl; Watters, James

2010-06-30

Hyperactivation of the Ras signaling pathway is a driver of many cancers, and RAS pathway activation can predict response to targeted therapies. Therefore, optimal methods for measuring Ras pathway activation are critical. The main focus of our work was to develop a gene expression signature that is predictive of RAS pathway dependence. We used the coherent expression of RAS pathway-related genes across multiple datasets to derive a RAS pathway gene expression signature and generate RAS pathway activation scores in pre-clinical cancer models and human tumors. We then related this signature to KRAS mutation status and drug response data in pre-clinical and clinical datasets. The RAS signature score is predictive of KRAS mutation status in lung tumors and cell lines with high (> 90%) sensitivity but relatively low (50%) specificity due to samples that have apparent RAS pathway activation in the absence of a KRAS mutation. In lung and breast cancer cell line panels, the RAS pathway signature score correlates with pMEK and pERK expression, and predicts resistance to AKT inhibition and sensitivity to MEK inhibition within both KRAS mutant and KRAS wild-type groups. The RAS pathway signature is upregulated in breast cancer cell lines that have acquired resistance to AKT inhibition, and is downregulated by inhibition of MEK. In lung cancer cell lines knockdown of KRAS using siRNA demonstrates that the RAS pathway signature is a better measure of dependence on RAS compared to KRAS mutation status. In human tumors, the RAS pathway signature is elevated in ER negative breast tumors and lung adenocarcinomas, and predicts resistance to cetuximab in metastatic colorectal cancer. These data demonstrate that the RAS pathway signature is superior to KRAS mutation status for the prediction of dependence on RAS signaling, can predict response to PI3K and RAS pathway inhibitors, and is likely to have the most clinical utility in lung and breast tumors.

A gene expression signature of RAS pathway dependence predicts response to PI3K and RAS pathway inhibitors and expands the population of RAS pathway activated tumors

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Paweletz Cloud

2010-06-01

Full Text Available Abstract Background Hyperactivation of the Ras signaling pathway is a driver of many cancers, and RAS pathway activation can predict response to targeted therapies. Therefore, optimal methods for measuring Ras pathway activation are critical. The main focus of our work was to develop a gene expression signature that is predictive of RAS pathway dependence. Methods We used the coherent expression of RAS pathway-related genes across multiple datasets to derive a RAS pathway gene expression signature and generate RAS pathway activation scores in pre-clinical cancer models and human tumors. We then related this signature to KRAS mutation status and drug response data in pre-clinical and clinical datasets. Results The RAS signature score is predictive of KRAS mutation status in lung tumors and cell lines with high (> 90% sensitivity but relatively low (50% specificity due to samples that have apparent RAS pathway activation in the absence of a KRAS mutation. In lung and breast cancer cell line panels, the RAS pathway signature score correlates with pMEK and pERK expression, and predicts resistance to AKT inhibition and sensitivity to MEK inhibition within both KRAS mutant and KRAS wild-type groups. The RAS pathway signature is upregulated in breast cancer cell lines that have acquired resistance to AKT inhibition, and is downregulated by inhibition of MEK. In lung cancer cell lines knockdown of KRAS using siRNA demonstrates that the RAS pathway signature is a better measure of dependence on RAS compared to KRAS mutation status. In human tumors, the RAS pathway signature is elevated in ER negative breast tumors and lung adenocarcinomas, and predicts resistance to cetuximab in metastatic colorectal cancer. Conclusions These data demonstrate that the RAS pathway signature is superior to KRAS mutation status for the prediction of dependence on RAS signaling, can predict response to PI3K and RAS pathway inhibitors, and is likely to have the most clinical

Inhibition of the kynurenine pathway protects against reactive microglial-associated reductions in the complexity of primary cortical neurons.

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O'Farrell, Katherine; Fagan, Eimear; Connor, Thomas J; Harkin, Andrew

2017-09-05

Brain glia possess the rate limiting enzyme indoleamine 2, 3-dioxygenase (IDO) which catalyses the conversion of tryptophan to kynurenine. Microglia also express kynurenine monooxygenase (KMO) and kynureninase (KYNU) which lead to the production of the free radical producing metabolites, 3-hydroxykynurenine and 3-hydroxyanthranillic acid respectively and subsequently production of the NMDA receptor agonist quinolinic acid. The aim of this study was to examine the effect of IFNγ-stimulated kynurenine pathway (KP) induction in microglia on neurite outgrowth and complexity, and to determine whether alterations could be abrogated using pharmacological inhibitors of the KP. BV-2 microglia were treated with IFNγ (5ng/ml) for 24h and conditioned media (CM) was placed on primary cortical neurons 3 days in vitro (DIV) for 48h. Neurons were fixed and neurite outgrowth and complexity was assessed using fluorescent immunocytochemistry followed by Sholl analysis. Results show increased mRNA expression of IDO, KMO and KYNU, and increased concentrations of tryptophan, kynurenine, and 3-hydroxykynurenine in the CM of IFNγ-stimulated BV-2 microglia. The IFNγ-stimulated BV-2 microglial CM reduced neurite outgrowth and complexity with reductions in various parameters of neurite outgrowth prevented when BV-2 microglia were pre-treated with either the IDO inhibitor, 1-methyltryptophan (1-MT) (L) (0.5mM; 30min), the KMO inhibitor, Ro 61-8048 (1μM; 30min), the synthetic glucocorticoid, dexamethasone (1μM; 2h) -which suppresses IFNγ-induced IDO - and the N-methyl-D-aspartate (NMDA) receptor antagonist, MK801 (0.1μM; 30min). Overall this study indicates that inhibition of the KP in microglia may be targeted to protect against reactive microglial-associated neuronal atrophy. Copyright © 2017 Elsevier B.V. All rights reserved.

A Novel Anti-Inflammatory Role for Ginkgolide B in Asthma via Inhibition of the ERK/MAPK Signaling Pathway

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Xiao Chu

2011-09-01

Full Text Available Ginkgolide B is an anti-inflammatory extract of Ginkgo biloba and has been used therapeutically. It is a known inhibitor of platelet activating factor (PAF, which is important in the pathogenesis of asthma. Here, a non-infectious mouse model of asthma is used to evaluate the anti-inflammatory capacity of ginkgolide B (GKB and characterize the interaction of GKB with the mitogen activated protein kinase (MAPK pathway. BALB/c mice that were sensitized and challenged to ovalbumin (OVA were treated with GKB (40 mg/kg one hour before they were challenged with OVA. Our study demonstrated that GKB may effectively inhibit the increase of T-helper 2 cytokines, such as interleukin (IL-5 and IL-13 in bronchoalveolar lavage fluid (BALF. Furthermore, the eosinophil count in BALF significantly decreased after treatment of GKB when compared with the OVA-challenged group. Histological studies demonstrated that GKB substantially inhibited OVA-induced eosinophilia in lung tissue and mucus hyper-secretion by goblet cells in the airway. These results suggest that ginkgolide B may be useful for the treatment of asthma and its efficacy is related to suppression of extracellular regulating kinase/MAPK pathway.

Aldose reductase inhibition prevents allergic airway remodeling through PI3K/AKT/GSK3β pathway in mice.

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Umesh C S Yadav

Full Text Available Long-term and unresolved airway inflammation and airway remodeling, characteristic features of chronic asthma, if not treated could lead to permanent structural changes in the airways. Aldose reductase (AR, an aldo-sugar and lipid aldehyde metabolizing enzyme, mediates allergen-induced airway inflammation in mice, but its role in the airway remodeling is not known. In the present study, we have examined the role of AR on airway remodeling using ovalbumin (OVA-induced chronic asthma mouse model and cultured human primary airway epithelial cells (SAECs and mouse lung fibroblasts (mLFs.Airway remodeling in chronic asthma model was established in mice sensitized and challenged twice a week with OVA for 6 weeks. AR inhibitor, fidarestat, was administered orally in drinking water after first challenge. Inflammatory cells infiltration in the lungs and goblet cell metaplasia, airway thickening, collagen deposition and airway hyper-responsiveness (AHR in response to increasing doses of methacholine were assessed. The TGFβ1-induced epithelial-mesenchymal transition (EMT in SAECs and changes in mLFs were examined to investigate AR-mediated molecular mechanism(s of airway remodeling.In the OVA-exposed mice for 6 wks inflammatory cells infiltration, levels of inflammatory cytokines and chemokines, goblet cell metaplasia, collagen deposition and AHR were significantly decreased by treatment with AR inhibitor, fidarestat. Further, inhibition of AR prevented TGFβ1-induced altered expression of E-cadherin, Vimentin, Occludin, and MMP-2 in SAECs, and alpha-smooth muscle actin and fibronectin in mLFs. Further, in SAECs, AR inhibition prevented TGFβ1- induced activation of PI3K/AKT/GSK3β pathway but not the phosphorylation of Smad2/3.Our results demonstrate that allergen-induced airway remodeling is mediated by AR and its inhibition blocks the progression of remodeling via inhibiting TGFβ1-induced Smad-independent and PI3K/AKT/GSK3β-dependent pathway.

Lasiodin inhibits proliferation of human nasopharyngeal carcinoma cells by simultaneous modulation of the Apaf-1/caspase, AKT/MAPK and COX-2/NF-κB signaling pathways.

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Lianzhu Lin

Full Text Available Rabdosia serra has been widely used for the treatment of the various human diseases. However, the antiproliferative effects and underlying mechanisms of the compounds in this herb remain largely unknown. In this study, an antiproliferative compound against human nasopharyngeal carcinoma (NPC cells from Rabdosia serra was purified and identified as lasiodin (a diterpenoid. The treatment with lasiodin inhibited cell viability and migration. Lasiodin also mediated the cell morphology change and induced apoptosis in NPC cells. The treatment with lasiodin induced the Apaf-1 expression, triggered the cytochrome-C release, and stimulated the PARP, caspase-3 and caspase-9 cleavages, thereby activating the apoptotic pathways. The treatment with lasiodin also significantly inhibited the phosphorylations of the AKT, ERK1/2, p38 and JNK proteins. The pretreatment with the AKT or MAPK-selective inhibitors considerably blocked the lasiodin-mediated inhibition of cell proliferation. Moreover, the treatment with lasiodin inhibited the COX-2 expression, abrogated NF-κB binding to the COX-2 promoter, and promoted the NF-κB translocation from cell nuclei to cytosol. The pretreatment with a COX-2-selective inhibitor abrogated the lasiodin-induced inhibition of cell proliferation. These results indicated that lasiodin simultaneously activated the Apaf-1/caspase-dependent apoptotic pathways and suppressed the AKT/MAPK and COX-2/NF-κB signaling pathways. This study also suggested that lasiodin could be a promising natural compound for the prevention and treatment of NPC.

Defining a novel leptin–melanocortin–kisspeptin pathway involved in the metabolic control of puberty

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Maria Manfredi-Lozano

2016-10-01

Full Text Available Objective: Puberty is a key developmental phenomenon highly sensitive to metabolic modulation. Worrying trends of changes in the timing of puberty have been reported in humans. These might be linked to the escalating prevalence of childhood obesity and could have deleterious impacts on later (cardio-metabolic health, but their underlying mechanisms remain unsolved. The neuropeptide α-MSH, made by POMC neurons, plays a key role in energy homeostasis by mediating the actions of leptin and likely participates in the control of reproduction. However, its role in the metabolic regulation of puberty and interplay with kisspeptin, an essential puberty-regulating neuropeptide encoded by Kiss1, remain largely unknown. We aim here to unveil the potential contribution of central α-MSH signaling in the metabolic control of puberty by addressing its role in mediating the pubertal effects of leptin and its potential interaction with kisspeptin. Methods: Using wild type and genetically modified rodent models, we implemented pharmacological studies, expression analyses, electrophysiological recordings, and virogenetic approaches involving DREADD technology to selectively inhibit Kiss1 neurons, in order to interrogate the physiological role of a putative leptin→α-MSH→kisspeptin pathway in the metabolic control of puberty. Results: Stimulation of central α-MSH signaling robustly activated the reproductive axis in pubertal rats, whereas chronic inhibition of melanocortin receptors MC3/4R, delayed puberty, and prevented the permissive effect of leptin on puberty onset. Central blockade of MC3/4R or genetic elimination of kisspeptin receptors from POMC neurons did not affect kisspeptin effects. Conversely, congenital ablation of kisspeptin receptors or inducible, DREADD-mediated inhibition of arcuate nucleus (ARC Kiss1 neurons resulted in markedly attenuated gonadotropic responses to MC3/4R activation. Furthermore, close appositions were observed between

Attenuation of everolimus-induced cytotoxicity by a protective autophagic pathway involving ERK activation in renal cell carcinoma cells

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Zeng, Yizhou; Tian, Xiaofang; Wang, Quan; He, Weiyang; Fan, Jing; Gou, Xin

2018-01-01

Aim The mammalian target of rapamycin (mTOR) pathway is a critical target for cancer treatment and the mTOR inhibitor everolimus (RAD001) has been approved for treatment of renal cell carcinoma (RCC). However, the limited efficacy of RAD001 has led to the development of drug resistance. Autophagy is closely related to cell survival and death, which may be activated under RAD001 stimulation. The aim of the present study was to identify the underlying mechanisms of RAD001 resistance in RCC cells through cytoprotective autophagy involving activation of the extracellular signal-regulated kinase (ERK) pathway. Methods and results: RAD001 strongly induced autophagy of RCC cells in a dose- and time-dependent manner, as confirmed by Western blot analysis. Importantly, suppression of autophagy by the pharmacological inhibitor chloroquine effectively enhanced RAD001-induced apoptotic cytotoxicity, as demonstrated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Western blot analysis, indicating a cytoprotective role for RAD001-induced autophagy. In addition, as was shown by the MTT assay, flow cytometry, and Western blot analysis, RAD001 robustly activated ERK, but not c-Jun N-terminal kinase and p38. Activation of ERK was inhibited by the pharmacological inhibitor selumetinib (AZD6244), which effectively promoted RAD001-induced cell death. Moreover, employing AZD6244 markedly attenuated RAD001-induced autophagy and enhanced RAD001-induced apoptosis, which play a central role in RAD001-induced cell death. Furthermore, RAD001-induced autophagy is regulated by ERK-mediated phosphorylation of Beclin-1 and B-cell lymphoma 2, as confirmed by Western blot analysis. Conclusion These results suggest that RAD001-induced autophagy involves activation of the ERK, which may impair cytotoxicity of RAD001 in RCC cells. Thus, inhibition of the activation of ERK pathway-mediated autophagy may be useful to overcome chemoresistance to RAD001. PMID:29719377

Loss of Mel-18 enhances breast cancer stem cell activity and tumorigenicity through activating Notch signaling mediated by the Wnt/TCF pathway.

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Won, Hee-Young; Lee, Jeong-Yeon; Shin, Dong-Hui; Park, Ji-Hye; Nam, Jeong-Seok; Kim, Hyoung-Chin; Kong, Gu

2012-12-01

Mel-18 has been proposed as a negative regulator of Bmi-1, a cancer stem cell (CSC) marker, but it is still unclear whether Mel-18 is involved in CSC regulation. Here, we examined the effect of Mel-18 on the stemness of human breast CSCs. In Mel-18 small hairpin RNA (shRNA)-transduced MCF-7 cells, side population (SP) cells and breast CSC surface marker (CD44(+)/CD24(-)/ESA(+))-expressing cells, which imply a CSC population, were enriched. Moreover, the self-renewal of CSCs was enhanced by Mel-18 knockdown, as measured by the ability for tumorsphere formation in vitro and tumor-initiating capacity in vivo. Similarly, Mel-18 overexpression inhibited the number and self-renewal activity of breast CSCs in SK-BR-3 cells. Furthermore, our data showed that Mel-18 blockade up-regulated the expression of the Wnt/TCF target Jagged-1, a Notch ligand, and consequently activated the Notch pathway. Pharmacologic inhibition of the Notch and Wnt pathways abrogated Mel-18 knockdown-mediated tumorsphere formation ability. Taken together, our findings suggest that Mel-18 is a novel negative regulator of breast CSCs that inhibits the stem cell population and in vitro and in vivo self-renewal through the inactivation of Wnt-mediated Notch signaling.

Inhibition of 5-Lipoxygenase Pathway Attenuates Acute Liver Failure by Inhibiting Macrophage Activation

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Lu Li

2014-01-01

Full Text Available This study aimed to investigate the role of 5-lipoxygenase (5-LO in acute liver failure (ALF and changes in macrophage activation by blocking it. ALF was induced in rats by administration of D-galactosamine (D-GalN/lipopolysaccharide (LPS. Rats were injected intraperitoneally with AA-861 (a specific 5-LO inhibitor, 24 hr before D-GalN/LPS administration. After D-GalN/LPS injection, the liver tissue was collected for assessment of histology, macrophage microstructure, macrophage counts, 5-LO mRNA formation, protein expression, and concentration of leukotrienes. Serum was collected for detecting alanine aminotransferase (ALT, aspartate transaminase (AST, total bilirubin (Tbil, and tumor necrosis factor- (TNF-α. Twenty-four hours after injection, compared with controls, ALF rats were characterized by widespread hepatocyte necrosis and elevated ALT, AST, and Tbil, and 5-LO protein expression reached a peak. Liver leukotriene B4 was also significantly elevated. However, 5-LO mRNA reached a peak 8 hr after D-GalN/LPS injection. Simultaneously, the microstructure of macrophages was changed most significantly and macrophages counts were increased significantly. Moreover, serum TNF-α was also elevated. By contrast, AA-861 pretreatment significantly decreased liver necrosis as well as all of the parameters compared with the rats without pretreatment. Macrophages, via the 5-LO pathway, play a critical role in ALF, and 5-LO inhibitor significantly alleviates ALF, possibly related to macrophage inhibition.

Inhibition of NF-κB promotes autophagy via JNK signaling pathway in porcine granulosa cells

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Gao, Hui; Lin, Lu; Haq, Ihtesham Ul; Zeng, Shen-ming

2016-01-01

The transcription factor nuclear factor-κB (NF-κB) plays an important role in diverse processes, including cell proliferation and differentiation, apoptosis and inflammation. However, the role of NF-κB in porcine follicle development is not clearly elucidated. In this study, we demonstrated that follicle stimulating hormone (FSH) increased the level of inhibitor of NF-κB (IκB) protein and promoted the cytoplasmic localization of p65, indicating that FSH inhibits the activation of NF-κB in porcine granulosa cells. Moreover, inhibition of NF-κB by FSH or another specific inhibitor of NF-κB, pyrrolidine dithiocarbamate (PDTC), could activate JNK signaling and enhance autophagic activity in porcine granulosa cells. Knockdown of RelA (p65) Subunit of NF-κB by RNA interference abrogated the activation of JNK signaling pathway and the increase of autophagic protein expression by FSH. Meanwhile, the functional significance of FSH or PDTC-mediated autophagy were further investigated. Our results demonstrated that the increased autophagy promoted progesterone secretion in porcine granulosa cells. Blockage of autophagy by chloroquine obviated the FSH or PDTC-induced progesterone production. Taken together, these results indicate that inhibition of NF-κB increased autophagy via JNK signaling, and promote steroidogenesis in porcine granulosa cells. Our results provide new insights into the regulation and function of autophagy in mammalian follicle development. - Highlights: • FSH inhibits the activation of NF-κB in porcine primary granulosa cells. • Inhibition of NF-κB by FSH promotes autophagy via JNK signaling in granulosa cells. • Increased autophagy contributes to progesterone production in granulosa cells. • This is the first report against beclin1 regulation in porcine granulosa cells.

Inhibition of NF-κB promotes autophagy via JNK signaling pathway in porcine granulosa cells

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Gao, Hui; Lin, Lu; Haq, Ihtesham Ul; Zeng, Shen-ming, E-mail: zengshenming@gmail.com

2016-04-22

The transcription factor nuclear factor-κB (NF-κB) plays an important role in diverse processes, including cell proliferation and differentiation, apoptosis and inflammation. However, the role of NF-κB in porcine follicle development is not clearly elucidated. In this study, we demonstrated that follicle stimulating hormone (FSH) increased the level of inhibitor of NF-κB (IκB) protein and promoted the cytoplasmic localization of p65, indicating that FSH inhibits the activation of NF-κB in porcine granulosa cells. Moreover, inhibition of NF-κB by FSH or another specific inhibitor of NF-κB, pyrrolidine dithiocarbamate (PDTC), could activate JNK signaling and enhance autophagic activity in porcine granulosa cells. Knockdown of RelA (p65) Subunit of NF-κB by RNA interference abrogated the activation of JNK signaling pathway and the increase of autophagic protein expression by FSH. Meanwhile, the functional significance of FSH or PDTC-mediated autophagy were further investigated. Our results demonstrated that the increased autophagy promoted progesterone secretion in porcine granulosa cells. Blockage of autophagy by chloroquine obviated the FSH or PDTC-induced progesterone production. Taken together, these results indicate that inhibition of NF-κB increased autophagy via JNK signaling, and promote steroidogenesis in porcine granulosa cells. Our results provide new insights into the regulation and function of autophagy in mammalian follicle development. - Highlights: • FSH inhibits the activation of NF-κB in porcine primary granulosa cells. • Inhibition of NF-κB by FSH promotes autophagy via JNK signaling in granulosa cells. • Increased autophagy contributes to progesterone production in granulosa cells. • This is the first report against beclin1 regulation in porcine granulosa cells.

[Pharmacological aspects of pain research in Germany].

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Niederberger, E; Kuner, R; Geißlinger, G

2015-10-01

In spite of several approved analgesics, the therapy of pain still constitutes a challenge due to the fact that the drugs do not exert sufficient efficacy or are associated with severe side effects. Therefore, the development of new and improved painkillers is still of great importance. A number of highly qualified scientists in Germany are investigating signal transduction pathways in pain, effectivity of new drugs and the so far incompletely investigated mechanisms of well-known analgesics in preclinical and clinical studies. The highlights of pharmacological pain research in Germany are summarized in this article.

Systems pharmacology-based drug discovery for marine resources: an example using sea cucumber (Holothurians).

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Guo, Yingying; Ding, Yan; Xu, Feifei; Liu, Baoyue; Kou, Zinong; Xiao, Wei; Zhu, Jingbo

2015-05-13

Sea cucumber, a kind of marine animal, have long been utilized as tonic and traditional remedies in the Middle East and Asia because of its effectiveness against hypertension, asthma, rheumatism, cuts and burns, impotence, and constipation. In this study, an overall study performed on sea cucumber was used as an example to show drug discovery from marine resource by using systems pharmacology model. The value of marine natural resources has been extensively considered because these resources can be potentially used to treat and prevent human diseases. However, the discovery of drugs from oceans is difficult, because of complex environments in terms of composition and active mechanisms. Thus, a comprehensive systems approach which could discover active constituents and their targets from marine resource, understand the biological basis for their pharmacological properties is necessary. In this study, a feasible pharmacological model based on systems pharmacology was established to investigate marine medicine by incorporating active compound screening, target identification, and network and pathway analysis. As a result, 106 candidate components of sea cucumber and 26 potential targets were identified. Furthermore, the functions of sea cucumber in health improvement and disease treatment were elucidated in a holistic way based on the established compound-target and target-disease networks, and incorporated pathways. This study established a novel strategy that could be used to explore specific active mechanisms and discover new drugs from marine sources. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Deciphering metabonomics biomarkers-targets interactions for psoriasis vulgaris by network pharmacology.

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Gu, Jiangyong; Li, Li; Wang, Dongmei; Zhu, Wei; Han, Ling; Zhao, Ruizhi; Xu, Xiaojie; Lu, Chuanjian

2018-06-01

Psoriasis vulgaris is a chronic inflammatory and immune-mediated skin disease. 44 metabonomics biomarkers were identified by high-throughput liquid chromatography coupled to mass spectrometry in our previous work, but the roles of metabonomics biomarkers in the pathogenesis of psoriasis is unclear. The metabonomics biomarker-enzyme network was constructed. The key metabonomics biomarkers and enzymes were screened out by network analysis. The binding affinity between each metabonomics biomarker and target was calculated by molecular docking. A binding energy-weighted polypharmacological index was introduced to evaluate the importance of target-related pathways. Long-chain fatty acids, phospholipids, Estradiol and NADH were the most important metabonomics biomarkers. Most key enzymes belonged hydrolase, thioesterase and acyltransferase. Six proteins (TNF-alpha, MAPK3, iNOS, eNOS, COX2 and mTOR) were extensively involved in inflammatory reaction, immune response and cell proliferation, and might be drug targets for psoriasis. PI3K-Akt signaling pathway and five other pathways had close correlation with the pathogenesis of psoriasis and could deserve further research. The inflammatory reaction, immune response and cell proliferation are mainly involved in psoriasis. Network pharmacology provide a new insight into the relationships between metabonomics biomarkers and the pathogenesis of psoriasis. KEY MESSAGES   • Network pharmacology was adopted to identify key metabonomics biomarkers and enzymes.   • Six proteins were screened out as important drug targets for psoriasis.   • A binding energy-weighted polypharmacological index was introduced to evaluate the importance of target-related pathways.

Fisetin inhibits human melanoma cell invasion through promotion of mesenchymal to epithelial transition and by targeting MAPK and NFκB signaling pathways.

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Harish Chandra Pal

Full Text Available Malignant melanoma is responsible for approximately 75% of skin cancer-related deaths. BRAF plays an important role in regulating the mitogen-activated protein kinase (MAPK signaling cascade in melanoma with activating mutations in the serine/threonine kinase BRAF occurring in 60-70% of malignant melanomas. The BRAF-MEK-ERK (MAPK pathway is a key regulator of melanoma cell invasion. In addition, activation of NFκB via the MAPK pathway is regulated through MEK-induced activation of IKK. These pathways are potential targets for prevention and treatment of melanoma. In this study, we investigated the effect of fisetin, a phytochemical present in fruits and vegetables, on melanoma cell invasion and epithelial-mesenchymal transition, and delineated the underlying molecular mechanism. Treatment of multiple human malignant melanoma cell lines with fisetin (5-20 µM resulted in inhibition of cell invasion. BRAF mutated melanoma cells were more sensitive to fisetin treatment, and this was associated with a decrease in the phosphorylation of MEK1/2 and ERK1/2. In addition, fisetin inhibited the activation of IKK leading to a reduction in the activation of the NFκB signaling pathway. Treatment of cells with an inhibitor of MEK1/2 (PD98059 or of NFκB (caffeic acid phenethyl ester also reduced melanoma cell invasion. Furthermore, treatment of fisetin promoted mesenchymal to epithelial transition in melanoma cells, which was associated with a decrease in mesenchymal markers (N-cadherin, vimentin, snail and fibronectin and an increase in epithelial markers (E-cadherin and desmoglein. Employing three dimensional skin equivalents consisting of A375 cells admixed with normal human keratinocytes embedded onto a collagen-constricted fibroblast matrix, we found that treatment of fisetin reduced the invasive potential of melanoma cells into the dermis and increased the expression of E-cadherin with a concomitant decrease in vimentin. These results indicate that

Fisetin Inhibits Human Melanoma Cell Invasion through Promotion of Mesenchymal to Epithelial Transition and by Targeting MAPK and NFκB Signaling Pathways

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Pal, Harish Chandra; Sharma, Samriti; Strickland, Leah Ray; Katiyar, Santosh K.; Ballestas, Mary E.; Athar, Mohammad; Elmets, Craig A.; Afaq, Farrukh

2014-01-01

Malignant melanoma is responsible for approximately 75% of skin cancer-related deaths. BRAF plays an important role in regulating the mitogen-activated protein kinase (MAPK) signaling cascade in melanoma with activating mutations in the serine/threonine kinase BRAF occurring in 60–70% of malignant melanomas. The BRAF-MEK-ERK (MAPK) pathway is a key regulator of melanoma cell invasion. In addition, activation of NFκB via the MAPK pathway is regulated through MEK-induced activation of IKK. These pathways are potential targets for prevention and treatment of melanoma. In this study, we investigated the effect of fisetin, a phytochemical present in fruits and vegetables, on melanoma cell invasion and epithelial-mesenchymal transition, and delineated the underlying molecular mechanism. Treatment of multiple human malignant melanoma cell lines with fisetin (5–20 µM) resulted in inhibition of cell invasion. BRAF mutated melanoma cells were more sensitive to fisetin treatment, and this was associated with a decrease in the phosphorylation of MEK1/2 and ERK1/2. In addition, fisetin inhibited the activation of IKK leading to a reduction in the activation of the NFκB signaling pathway. Treatment of cells with an inhibitor of MEK1/2 (PD98059) or of NFκB (caffeic acid phenethyl ester) also reduced melanoma cell invasion. Furthermore, treatment of fisetin promoted mesenchymal to epithelial transition in melanoma cells, which was associated with a decrease in mesenchymal markers (N-cadherin, vimentin, snail and fibronectin) and an increase in epithelial markers (E-cadherin and desmoglein). Employing three dimensional skin equivalents consisting of A375 cells admixed with normal human keratinocytes embedded onto a collagen-constricted fibroblast matrix, we found that treatment of fisetin reduced the invasive potential of melanoma cells into the dermis and increased the expression of E-cadherin with a concomitant decrease in vimentin. These results indicate that fisetin

Blocking Ihh signaling pathway inhibits the proliferation and promotes the apoptosis of PSCs.

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Xu, Kai; Guo, Fengjing; Zhang, Shuwei; Liu, Cheng; Wang, Feixiong; Zhou, Zhiguo; Chen, Anmin

2009-02-01

The roles of Indian hedgehog (Ihh) signaling pathway in the proliferation and apoptosis of precartilaginous stem cells (PSCs) were investigated. PSCs, labeled with fibroblast growth factor receptor 3 (FGFR-3), were isolated from neonatal rats by immunomagnetic separation. After identification with FGFR-3 and Col II, the cells were incubated with different concentrations of cyclopamine (cyclo), the specific inhibitor of Ihh signaling pathway. The morphologic changes of the cells were observed under the inverted phase contrast microscope. The mRNA expression levels of Ihh, parathyroid hormonerelated peptide (PTHrP), protein Patched (Ptch), Bcl-2 and p21 were detected by RT-PCR. The protein expression levels of Ihh and Ptch were measured by Western blot. MTT assay was used to examine the effects of cyclo on proliferation of PSCs. Apoptosis rate of PSCs was examined by Annexin V/PI assay of flow cytometric analyses. After PSCs were incubated with cyclo, obvious morphologic changes were observed as compared with the control group. The mRNA expression levels of PTHrP, Ptch and Bcl-2 were decreased to varying degrees in a cyclo dose-dependent manner. However, the expression levels of Ihh and p21 mRNA were increased. The protein expression of Ptch and Ihh had the same change as the mRNA expression. Meanwhile, cyclo could obviously inhibit the proliferation and promote the apoptosis of PSCs. The results indicated that Ihh signaling pathway plays an important role in regulating the proliferation and apoptosis of PSCs, which is probably mediated by Bcl-2 and p21.

The pharmacology of neurokinin receptors in addiction: prospects for therapy

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Sandweiss AJ

2015-09-01

Full Text Available Alexander J Sandweiss, Todd W VanderahDepartment of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ, USAAbstract: Addiction is a chronic disorder in which consumption of a substance or a habitual behavior becomes compulsive and often recurrent, despite adverse consequences. Substance p (SP is an undecapeptide and was the first neuropeptide of the neurokinin family to be discovered. The subsequent decades of research after its discovery implicated SP and its neurokinin relatives as neurotransmitters involved in the modulation of the reward pathway. Here, we review the neurokinin literature, giving a brief historical perspective of neurokinin pharmacology, localization in various brain regions involved in addictive behaviors, and the functional aspects of neurokinin pharmacology in relation to reward in preclinical models of addiction that have shaped the rational drug design of neurokinin antagonists that could translate into human research. Finally, we will cover the clinical investigations using neurokinin antagonists and discuss their potential as a therapy for drug abuse.Keywords: reward, substance p, alcohol, morphine, cocaine, dopamine

Peretinoin, an Acyclic Retinoid, Inhibits Hepatitis B Virus Replication by Suppressing Sphingosine Metabolic Pathway In Vitro

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Kazuhisa Murai

2018-01-01

Full Text Available Hepatocellular carcinoma (HCC frequently develops from hepatitis C virus (HCV and hepatitis B virus (HBV infection. We previously reported that peretinoin, an acyclic retinoid, inhibits HCV replication. This study aimed to examine the influence of peretinoin on the HBV lifecycle. HBV-DNA and covalently closed circular DNA (cccDNA were evaluated by a qPCR method in HepG2.2.15 cells. Peretinoin significantly reduced the levels of intracellular HBV-DNA, nuclear cccDNA, and HBV transcript at a concentration that did not induce cytotoxicity. Conversely, other retinoids, such as 9-cis, 13-cis retinoic acid (RA, and all-trans-retinoic acid (ATRA, had no effect or rather increased HBV replication. Mechanistically, although peretinoin increased the expression of HBV-related transcription factors, as observed for other retinoids, peretinoin enhanced the binding of histone deacetylase 1 (HDAC1 to cccDNA in the nucleus and negatively regulated HBV transcription. Moreover, peretinoin significantly inhibited the expression of SPHK1, a potential inhibitor of HDAC activity, and might be involved in hepatic inflammation, fibrosis, and HCC. SPHK1 overexpression in cells cancelled the inhibition of HBV replication induced by peretinoin. This indicates that peretinoin activates HDAC1 and thereby suppresses HBV replication by inhibiting the sphingosine metabolic pathway. Therefore, peretinoin may be a novel therapeutic agent for HBV replication and chemoprevention against HCC.

RXR agonists inhibit high glucose-induced upregulation of inflammation by suppressing activation of the NADPH oxidase-nuclear factor-κB pathway in human endothelial cells.

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Ning, R B; Zhu, J; Chai, D J; Xu, C S; Xie, H; Lin, X Y; Zeng, J Z; Lin, J X

2013-12-13

An inflammatory response induced by high glucose is a cause of endothelial dysfunction in diabetes and is an important contributing link to atherosclerosis. Diabetes is an independent risk factor of atherosclerosis and activation of retinoid X receptor (RXR) has been shown to exert anti-atherogenic effects. In the present study, we examined the effects of the RXR ligands 9-cis-retinoic acid (9-cis-RA) and SR11237 on high glucose-induced inflammation in human umbilical endothelial vein endothelial cells (HUVECs) and explored the potential mechanism. Our results showed that the inflammation induced by high-glucose in HUVECs was mainly mediated by the activation of nuclear factor-B (NF- κB). High glucose-induced expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were in comparison, significantly decreased by treatment with RXR. The effect of RXR agonists was mainly due to the inhibition of NF-κB activation. Using pharmacological inhibitors and siRNA, we confirmed that nicotinamide adenine dinucleotide phosphate (NADPH) oxidase was an upstream activator of NF-κB. Furthermore, RXR agonists significantly inhibited high glucose-induced activation of NADPH oxidase and significantly decreased the production of reactive oxygen species (ROS). To explore whether the rapid inhibitory effects of RXR agonists were in fact mediated by RXR, we examined the effect of RXR downregulation by RXR siRNA. Our results showed that RXR siRNA largely abrogated the effects of RXR agonists, suggesting the requirement of RXR expression. Therefore, we have shown that RXR is involved in the regulation of NADPH oxidase- NF-κB signal pathway, as the RXR ligands antagonized the inflammatory response in HUVECs induced by high glucose.

Transient mTOR inhibition facilitates continuous growth of liver tumors by modulating the maintenance of CD133+ cell populations.

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Zhaojuan Yang

Full Text Available The mammalian target of the rapamycin (mTOR pathway, which drives cell proliferation, is frequently hyperactivated in a variety of malignancies. Therefore, the inhibition of the mTOR pathway has been considered as an appropriate approach for cancer therapy. In this study, we examined the roles of mTOR in the maintenance and differentiation of cancer stem-like cells (CSCs, the conversion of conventional cancer cells to CSCs and continuous tumor growth in vivo. In H-Ras-transformed mouse liver tumor cells, we found that pharmacological inhibition of mTOR with rapamycin greatly increased not only the CD133+ populations both in vitro and in vivo but also the expression of stem cell-like genes. Enhancing mTOR activity by over-expressing Rheb significantly decreased CD133 expression, whereas knockdown of the mTOR yielded an opposite effect. In addition, mTOR inhibition severely blocked the differentiation of CD133+ to CD133- liver tumor cells. Strikingly, single-cell culture experiments revealed that CD133- liver tumor cells were capable of converting to CD133+ cells and the inhibition of mTOR signaling substantially promoted this conversion. In serial implantation of tumor xenografts in nude BALB/c mice, the residual tumor cells that were exposed to rapamycin in vivo displayed higher CD133 expression and had increased secondary tumorigenicity compared with the control group. Moreover, rapamycin treatment also enhanced the level of stem cell-associated genes and CD133 expression in certain human liver tumor cell lines, such as Huh7, PLC/PRC/7 and Hep3B. The mTOR pathway is significantly involved in the generation and the differentiation of tumorigenic liver CSCs. These results may be valuable for the design of more rational strategies to control clinical malignant HCC using mTOR inhibitors.

Embryotoxic and pharmacologic potency ranking of six azoles in the rat whole embryo culture by morphological and transcriptomic analysis

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Dimopoulou, Myrto; Verhoef, Aart; Pennings, Jeroen L.A.; Ravenzwaay, Bennard van; Rietjens, Ivonne M.C.M.; Piersma, Aldert H.

2017-01-01

Differential gene expression analysis in the rat whole embryo culture (WEC) assay provides mechanistic insight into the embryotoxicity of test compounds. In our study, we hypothesized that comparative analysis of the transcriptomes of rat embryos exposed to six azoles (flusilazole, triadimefon, ketoconazole, miconazole, difenoconazole and prothioconazole) could lead to a better mechanism-based understanding of their embryotoxicity and pharmacological action. For evaluating embryotoxicity, we applied the total morphological scoring system (TMS) in embryos exposed for 48 h. The compounds tested showed embryotoxicity in a dose-response fashion. Functional analysis of differential gene expression after 4 h exposure at the ID 10 (effective dose for 10% decreased TMS), revealed the sterol biosynthesis pathway and embryonic development genes, dominated by genes in the retinoic acid (RA) pathway, albeit in a differential way. Flusilazole, ketoconazole and triadimefon were the most potent compounds affecting the RA pathway, while in terms of regulation of sterol function, difenoconazole and ketoconazole showed the most pronounced effects. Dose-dependent analysis of the effects of flusilazole revealed that the RA pathway related genes were already differentially expressed at low dose levels while the sterol pathway showed strong regulation at higher embryotoxic doses, suggesting that this pathway is less predictive for the observed embryotoxicity. A similar analysis at the 24-hour time point indicated an additional time-dependent difference in the aforementioned pathways regulated by flusilazole. In summary, the rat WEC assay in combination with transcriptomics could add a mechanistic insight into the embryotoxic potency ranking and pharmacological mode of action of the tested compounds. - Highlights: • Embryonic exposure to azoles revealed concentration-dependent malformations. • Transcriptomics could enhance the mechanistic knowledge of embryotoxicants. • Retinoic

Embryotoxic and pharmacologic potency ranking of six azoles in the rat whole embryo culture by morphological and transcriptomic analysis

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Dimopoulou, Myrto, E-mail: myrto.dimopoulou@wur.nl [Division of Toxicology, Wageningen University (Netherlands); National Institute of Public Health and the Environment (RIVM), Bilthoven (Netherlands); Verhoef, Aart; Pennings, Jeroen L.A. [National Institute of Public Health and the Environment (RIVM), Bilthoven (Netherlands); Ravenzwaay, Bennard van [Division of Toxicology, Wageningen University (Netherlands); BASF SE, Experimental Toxicology and Ecology, Ludwigshafen (Germany); Rietjens, Ivonne M.C.M. [Division of Toxicology, Wageningen University (Netherlands); Piersma, Aldert H. [National Institute of Public Health and the Environment (RIVM), Bilthoven (Netherlands); Institute for Risk Assessment Sciences, Utrecht University, Utrecht (Netherlands)

2017-05-01

Differential gene expression analysis in the rat whole embryo culture (WEC) assay provides mechanistic insight into the embryotoxicity of test compounds. In our study, we hypothesized that comparative analysis of the transcriptomes of rat embryos exposed to six azoles (flusilazole, triadimefon, ketoconazole, miconazole, difenoconazole and prothioconazole) could lead to a better mechanism-based understanding of their embryotoxicity and pharmacological action. For evaluating embryotoxicity, we applied the total morphological scoring system (TMS) in embryos exposed for 48 h. The compounds tested showed embryotoxicity in a dose-response fashion. Functional analysis of differential gene expression after 4 h exposure at the ID{sub 10} (effective dose for 10% decreased TMS), revealed the sterol biosynthesis pathway and embryonic development genes, dominated by genes in the retinoic acid (RA) pathway, albeit in a differential way. Flusilazole, ketoconazole and triadimefon were the most potent compounds affecting the RA pathway, while in terms of regulation of sterol function, difenoconazole and ketoconazole showed the most pronounced effects. Dose-dependent analysis of the effects of flusilazole revealed that the RA pathway related genes were already differentially expressed at low dose levels while the sterol pathway showed strong regulation at higher embryotoxic doses, suggesting that this pathway is less predictive for the observed embryotoxicity. A similar analysis at the 24-hour time point indicated an additional time-dependent difference in the aforementioned pathways regulated by flusilazole. In summary, the rat WEC assay in combination with transcriptomics could add a mechanistic insight into the embryotoxic potency ranking and pharmacological mode of action of the tested compounds. - Highlights: • Embryonic exposure to azoles revealed concentration-dependent malformations. • Transcriptomics could enhance the mechanistic knowledge of embryotoxicants. �

p16(INK4A) inhibits the pro-metastatic potentials of osteosarcoma cells through targeting the ERK pathway and TGF-β1.

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Silva, Gabriela; Aboussekhra, Abdelilah

2016-05-01

Extracellular signal-regulated kinase (ERK) is a downstream component of the evolutionarily conserved mitogen-activated protein kinase-signaling pathway, which controls the expression of a plethora of genes implicated in various physiological processes. This pathway is often hyper-activated by mutations or abnormal extracellular signaling in different types of human cancer, including the most common primary malignant bone tumor osteosarcomas. p16(INK4A) is an important tumor suppressor gene frequently lost in osteosarcomas, and is associated with the progression of these malignancies. We have shown, here, that the ERK1/2 protein kinase is also activated by p16(INK4A) down-regulation in osteosarcoma cells and normal human as well as mouse cells. This inhibitory effect is associated with the suppression of the upstream kinase MEK1/2, and is mediated via the repression of miR-21-5p and the consequent up-regulation of the MEK/ERK antagonist SPRY2 in osteosarcoma cells. Furthermore, we have shown that p16(INK4) inhibits the migration/invasion abilities of these cells through miR-21-5p-dependent inhibition of ERK1/2. In addition, we present clear evidence that p16(INK4) represses the paracrine pro-migratory effect of osteosarcoma cells on stromal fibroblasts through the inhibition of the TGF-β1 expression/secretion. This effect is also ERK1/2-dependent, indicating that in addition to their cell-autonomous actions, p16(INK4) and ERK1/2 have also non-cell-autonomous cancer-related functions. Together, these results indicate that the tumor suppressor p16(INK4) protein represses the carcinogenic process of osteosarcoma cells not only as a cell cycle regulator, but also as a negative regulator of pro-carcinogenic/-metastatic pathways. This indicates that targeting the ERK pathway is of utmost therapeutic value. © 2015 Wiley Periodicals, Inc.

Methyl Protodioscin from the Roots of Asparagus cochinchinensis Attenuates Airway Inflammation by Inhibiting Cytokine Production

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Ju Hee Lee

2015-01-01

Full Text Available The present study was designed to find pharmacologically active compound against airway inflammation from the roots of Asparagus cochinchinensis. The 70% ethanol extract of the roots of A. cochinchinensis (ACE was found to inhibit IL-6 production from IL-1β-treated lung epithelial cells (A549 and the major constituent, methyl protodioscin (MP, also strongly inhibited the production of IL-6, IL-8, and tumor necrosis factor- (TNF- α from A549 cells at 10–100 μM. This downregulating effect of proinflammatory cytokine production was found to be mediated, at least in part, via inhibition of c-Jun N-terminal kinase (JNK and c-Jun activation pathway. When examined on an in vivo model of airway inflammation in mice, lipopolysaccharide- (LPS- induced acute lung injury, ACE, and MP significantly inhibited cell infiltration in the bronchoalveolar lavage fluid by the oral treatment at doses of 100–400 mg/kg and 30–60 mg/kg, respectively. MP also inhibited the production of proinflammatory cytokines such as IL-6, TNF-α, and IL-1β in lung tissue. All of these findings provide scientific evidence supporting the role of A. cochinchinensis as a herbal remedy in treating airway inflammation and also suggest a therapeutic value of MP on airway inflammatory disorders.

Sodium Ferulate Prevents Daunorubicin - Induced Apoptosis in H9c2 Cells via Inhibition of the ERKs Pathway

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Zhi-Juan Wu

2015-07-01

Full Text Available Background: Daunorubicin (DNR-induced cardiotoxicity, which is closely associated with cardiomyocyte apoptosis, limits the drug's clinical application. The activation of the extracellular regulated protein kinases (ERKs pathway is responsible for the pro-apoptosis effect of DNR Sodium ferulate (SF has recently been found to attenuate both DNR-induced cardiotoxicity and mitochondrial apoptosis in juvenile rats. Nonetheless, the precise mechanism underlying SF-induced cardio-protection remains unclear. Methods: The DNR-injured H9c2 cell model was prepared by incubating the cells in 1 µM DNR for 24 h. Amounts of 15.6, 31.3 or 62.5 µM SF were simultaneously added to the cells. The effect of SF on the cytotoxic and apoptotic parameters of the cells was studied by monitoring apoptosis regulation via the ERKs pathway. Results: SF attenuated DNR-induced cell death (particularly apoptotic death, cTnI and β-tubulin degradation, and cellular morphological changes. SF reduced mitochondrial membrane potential depolarization, cytochrome c leakage, and caspase-9 and caspase-3 activation. SF also decreased ERK1/2, phospho-ERK1/2, p53 and Bax expression and increased Bcl-2 expression. These effects were similar to the results observed when using the pharmacological ERKs phosphorylation inhibitor, AZD6244. Conclusion: We determined that SF protects H9c2 cells from DNR-induced apoptosis through a mechanism that involves the interruption of the ERKs signaling pathway.

Modulation of post-stroke degenerative and regenerative processes and subacute protection by site-targeted inhibition of the alternative pathway of complement.

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Alawieh, Ali; Elvington, Andrew; Zhu, Hong; Yu, Jin; Kindy, Mark S; Atkinson, Carl; Tomlinson, Stephen

2015-12-30

Complement promotes neuroinflammation and injury in models of stroke. However, complement is also being increasingly implicated in repair and regeneration after central nervous system (CNS) injury, and some complement deficiencies have been shown to provide acute, but not subacute, protection after murine stroke. Here, we investigate the dual role of complement in injury and repair after cerebral ischemia and reperfusion. We used complement-deficient mice and different complement inhibitors in a model of transient middle cerebral artery occlusion to investigate complement-dependent cellular and molecular changes that occur through the subacute phase after stroke. C3 deficiency and site-targeted complement inhibition with either CR2-Crry (inhibits all pathways) or CR2-fH (inhibits alternative pathway) significantly reduced infarct size, reduced apoptotic cell death, and improved neurological deficit score in the acute phase after stroke. However, only in CR2-fH-treated mice was there sustained protection with no evolution of injury in the subacute phase. Whereas both inhibitors significantly reduced microglia/macrophage activation and astrogliosis in the subacute phase, only CR2-fH improved neurological deficit and locomotor function, maintained neurogenesis markers, enhanced neuronal migration, and increased VEGF expression. These findings in CR2-fH-treated mice correlated with improved performance in spatial learning and passive avoidance tasks. The complement anaphylatoxins have been implicated in repair and regenerative mechanisms after CNS injury, and in this context CR2-fH significantly reduced, but did not eliminate the generation of C5a within the brain, unlike CR2-Crry that completely blocked C5a generation. Gene expression profiling revealed that CR2-fH treatment downregulated genes associated with apoptosis, TGFβ signaling, and neutrophil activation, and decreased neutrophil infiltration was confirmed by immunohistochemistry. CR2-fH upregulated genes for

Cyclooxygenase inhibition improves endothelial vasomotor dysfunction of visceral adipose arterioles in human obesity

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Farb, Melissa G.; Tiwari, Stephanie; Karki, Shakun; Ngo, Doan TM; Carmine, Brian; Hess, Donald T.; Zuriaga, Maria A.; Walsh, Kenneth; Fetterman, Jessica L.; Hamburg, Naomi M.; Vita, Joseph A.; Apovian, Caroline M.; Gokce, Noyan

2013-01-01

Objective The purpose of this study was to determine whether cyclooxygenase inhibition improves vascular dysfunction of adipose microvessels from obese humans. Design and Methods In 20 obese subjects (age 37±12 yrs, BMI 47±8 kg/m2) we collected subcutaneous and visceral fat during bariatric surgery and characterized adipose depot-specific gene expression, endothelial cell phenotype, and microvascular function. Vasomotor function was assessed in response to endothelium-dependent agonists using videomicroscopy of small arterioles from fat. Results Arterioles from visceral fat exhibited impaired endothelium-dependent, acetylcholine-mediated vasodilation, compared to the subcutaneous depot (p<0.001). Expression of mRNA transcripts relevant to the cyclooxygenase pathway were upregulated in visceral compared to subcutaneous fat. Pharmacological inhibition of cyclooxygenase with indomethacin improved endothelium-dependent vasodilator function of arterioles from visceral fat by 2-fold (p=0.01), whereas indomethacin had no effect in the subcutaneous depot. Indomethacin increased activation via serine-1177 phosphorylation of endothelial nitric oxide synthase in response to acetylcholine in endothelial cells from visceral fat. Inhibition of endothelial nitric oxide synthase with Nω-nitro-L-arginine methyl ester abrogated the effects of cyclooxygenase-inhibition suggesting that vascular actions of indomethacin were related to increased nitric oxide bioavailability. Conclusions Our findings suggest that cyclooxygenase-mediated vasoconstrictor prostanoids partly contribute to endothelial dysfunction of visceral adipose arterioles in human obesity. PMID:23640904

OSU-A9 inhibits angiogenesis in human umbilical vein endothelial cells via disrupting Akt–NF-κB and MAPK signaling pathways

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Omar, Hany A. [Division of Medicinal Chemistry, College of Pharmacy, The Ohio State University, Columbus, OH 43210 (United States); Department of Pharmacology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514 (Egypt); Arafa, El-Shaimaa A. [Department of Pharmacology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514 (Egypt); Salama, Samir A. [Department of Biochemistry, Faculty of Pharmacy, Al-Azhar University, Cairo 11511 (Egypt); Arab, Hany H. [Department of Biochemistry, Faculty of Pharmacy, Cairo University, Cairo 11562 (Egypt); Wu, Chieh-Hsi, E-mail: chhswu@mail.cmu.edu.tw [School of Pharmacy, China Medical University, Taichung 40402, Taiwan (China); Weng, Jing-Ru, E-mail: columnster@gmail.com [Department of Biological Science and Technology, China Medical University, Taichung 40402, Taiwan (China)

2013-11-01

Since the introduction of angiogenesis as a useful target for cancer therapy, few agents have been approved for clinical use due to the rapid development of resistance. This problem can be minimized by simultaneous targeting of multiple angiogenesis signaling pathways, a potential strategy in cancer management known as polypharmacology. The current study aimed at exploring the anti-angiogenic activity of OSU-A9, an indole-3-carbinol-derived pleotropic agent that targets mainly Akt–nuclear factor-kappa B (NF-κB) signaling which regulates many key players of angiogenesis such as vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs). Human umbilical vein endothelial cells (HUVECs) were used to study the in vitro anti-angiogenic effect of OSU-A9 on several key steps of angiogenesis. Results showed that OSU-A9 effectively inhibited cell proliferation and induced apoptosis and cell cycle arrest in HUVECs. Besides, OSU-A9 inhibited angiogenesis as evidenced by abrogation of migration/invasion and Matrigel tube formation in HUVECs and attenuation of the in vivo neovascularization in the chicken chorioallantoic membrane assay. Mechanistically, Western blot, RT-PCR and ELISA analyses showed the ability of OSU-A9 to inhibit MMP-2 production and VEGF expression induced by hypoxia or phorbol-12-myristyl-13-acetate. Furthermore, dual inhibition of Akt–NF-κB and mitogen-activated protein kinase (MAPK) signaling, the key regulators of angiogenesis, was observed. Together, the current study highlights evidences for the promising anti-angiogenic activity of OSU-A9, at least in part through the inhibition of Akt–NF-κB and MAPK signaling and their consequent inhibition of VEGF and MMP-2. These findings support OSU-A9's clinical promise as a component of anticancer therapy. - Highlights: • The antiangiogenic activity of OSU-A9 in HUVECs was explored. • OSU-A9 inhibited HUVECs proliferation, migration, invasion and tube formation. • OSU-A9

Novel contraceptive targets to inhibit ovulation: the prostaglandin E2 pathway

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Duffy, Diane M.

2015-01-01

BACKGROUND Prostaglandin E2 (PGE2) is an essential intrafollicular regulator of ovulation. In contrast with the one-gene, one-protein concept for synthesis of peptide signaling molecules, production and metabolism of bioactive PGE2 requires controlled expression of many proteins, correct subcellular localization of enzymes, coordinated PGE2 synthesis and metabolism, and prostaglandin transport in and out of cells to facilitate PGE2 action and degradation. Elevated intrafollicular PGE2 is required for successful ovulation, so disruption of PGE2 synthesis, metabolism or transport may yield effective contraceptive strategies. METHODS This review summarizes case reports and studies on ovulation inhibition in women and macaques treated with cyclooxygenase inhibitors published from 1987 to 2014. These findings are discussed in the context of studies describing levels of mRNA, protein, and activity of prostaglandin synthesis and metabolic enzymes as well as prostaglandin transporters in ovarian cells. RESULTS The ovulatory surge of LH regulates the expression of each component of the PGE2 synthesis-metabolism-transport pathway within the ovulatory follicle. Data from primary ovarian cells and cancer cell lines suggest that enzymes and transporters can cooperate to optimize bioactive PGE2 levels. Elevated intrafollicular PGE2 mediates key ovulatory events including cumulus expansion, follicle rupture and oocyte release. Inhibitors of the prostaglandin-endoperoxide synthase 2 (PTGS2) enzyme (also known as cyclooxygenase-2 or COX2) reduce ovulation rates in women. Studies in macaques show that PTGS2 inhibitors can reduce the rates of cumulus expansion, oocyte release, follicle rupture, oocyte nuclear maturation and fertilization. A PTGS2 inhibitor reduced pregnancy rates in breeding macaques when administered to simulate emergency contraception. However, PTGS2 inhibition did not prevent pregnancy in monkeys when administered to simulate monthly contraceptive use. CONCLUSION

Picrasidine I from Picrasma Quassioides Suppresses Osteoclastogenesis via Inhibition of RANKL Induced Signaling Pathways and Attenuation of ROS Production

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Lingbo Kong

2017-10-01

Full Text Available Background/Aims: Osteoporosis is a metabolic bone disorder that tortures about millions of people worldwide. Recent study demonstrated agents derived from picrasma quassioides is a promising drug for targets multiple signaling pathways. However its potential in treatment of bone loss has not been fully understood. Methods: The bone marrow macrophages (BMMs were cultured and induced with M-CSF and RANKL followed by picrasidine I (PI treatment. Then the effects of PI on osteoclast formation were evaluated by counting tartrate-resistant acid phosphatase (TRAP-positive multinucleated cells. Moreover, effects of PI on bone resorption activity of mature osteoclast were studied through bone resorption pit counting and actin ring structure analysis. Further, the involved potential signaling pathways cross-talking were investigated by performed Western blotting and quantitative real-time PCR examination. Results: Results demonstrated PI strongly inhibited RANKL induced osteoclast formation from its precursors. Mechanistically, the inhibitory effect of PI on osteoclast differentiation was due to the suppression of osteoclastogenic transcription factors, c-Fos and NFATc1. Moreover, PI markedly blocked the RANKL-induced osteoclastogenesis by attenuating MAPKs and NF-κB signaling pathways. In addition, PI decreased the ROS generation in osteoclast and osteoblast. Conclusion: Taken together our data demonstrate that PI has antiosteoclastogenic effect by inhibiting inflammation induced activation of MAPKs, NF-κB and ROS generation followed by suppressing the gene expression of c-Fos and NFATc1 in osteoclast precursors.

Electroacupuncture Inhibits the Activation of p38MAPK in the Central Descending Facilitatory Pathway in Rats with Inflammatory Pain

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Man-Li Hu

2017-01-01

Full Text Available The mitogen-activated protein kinases (MAPKs, especially p38MAPK, play a pivotal role in chronic pain. Electroacupuncture (EA relieves inflammatory pain underlying the descending pathway, that is, the periaqueductal gray (PAG, the rostral ventromedial medulla (RVM, and the spinal cord dorsal horn (SCDH. However, whether EA antagonizes inflammatory pain through regulation of p38MAPK in this descending facilitatory pathway is unclear. Complete Freund’s adjuvant (CFA was injected into the hind paw of rats to establish inflammatory pain model. EA was administrated for 30 min at Zusanli and Kunlun acupoints at 0.5, 24.5, 48.5, and 72.5 h, respectively. The paw withdrawal threshold (PWT, paw edema, and Phosphor-p38MAPK-Immunoreactivity (p-p38MAPK-IR cells were measured before (0 h and at 1, 3, 5, 7, 25, and 73 h after CFA or saline injection. EA increased PWT at 1, 3, 25, and 73 h and inhibited paw edema at 25 and 73 h after CFA injection. Moreover, the increasing number of p-p38MAPK-IR cells which was induced by CFA was suppressed by EA stimulation in PAG and RVM at 3 and 5 h and in SCDH at 5, 7, 25, and 73 h. These results suggest that EA suppresses inflammation-induced hyperalgesia probably through inhibiting p38MAPK activation in the descending facilitatory pathway.

Curcumin alleviates macrophage activation and lung inflammation induced by influenza virus infection through inhibiting the NF-κB signaling pathway.

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Xu, Yiming; Liu, Ling

2017-09-01

Influenza A viruses (IAV) result in severe public health problems with worldwide each year. Overresponse of immune system to IAV infection leads to complications, and ultimately causing morbidity and mortality. Curcumin has been reported to have anti-inflammatory ability. However, its molecular mechanism in immune responses remains unclear. We detected the pro-inflammatory cytokine secretion and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB)-related protein expression in human macrophages or mice infected by IAV with or without curcumin treatment. We found that the IAV infection caused a dramatic enhancement of pro-inflammatory cytokine productions of human macrophages and mice immune cells. However, curcumin treatment after IAV infection downregulated these cytokines production in a dose-dependent manner. Moreover, the NF-κB has been activated in human macrophages after IAV infection, while administration of curcumin inhibited NF-κB signaling pathway via promoting the expression of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα), and inhibiting the translocation of p65 from cytoplasm to nucleus. In summary, IAV infection could result in the inflammatory responses of immune cells, especially macrophages. Curcumin has the therapeutic potentials to relieve these inflammatory responses through inhibiting the NF-κB signaling pathway. © 2017 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

Ribosomal protein mutations induce autophagy through S6 kinase inhibition of the insulin pathway.

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Harry F Heijnen

Full Text Available Mutations affecting the ribosome lead to several diseases known as ribosomopathies, with phenotypes that include growth defects, cytopenia, and bone marrow failure. Diamond-Blackfan anemia (DBA, for example, is a pure red cell aplasia linked to the mutation of ribosomal protein (RP genes. Here we show the knock-down of the DBA-linked RPS19 gene induces the cellular self-digestion process of autophagy, a pathway critical for proper hematopoiesis. We also observe an increase of autophagy in cells derived from DBA patients, in CD34+ erythrocyte progenitor cells with RPS19 knock down, in the red blood cells of zebrafish embryos with RP-deficiency, and in cells from patients with Shwachman-Diamond syndrome (SDS. The loss of RPs in all these models results in a marked increase in S6 kinase phosphorylation that we find is triggered by an increase in reactive oxygen species (ROS. We show that this increase in S6 kinase phosphorylation inhibits the insulin pathway and AKT phosphorylation activity through a mechanism reminiscent of insulin resistance. While stimulating RP-deficient cells with insulin reduces autophagy, antioxidant treatment reduces S6 kinase phosphorylation, autophagy, and stabilization of the p53 tumor suppressor. Our data suggest that RP loss promotes the aberrant activation of both S6 kinase and p53 by increasing intracellular ROS levels. The deregulation of these signaling pathways is likely playing a major role in the pathophysiology of ribosomopathies.

GYF-21, an Epoxide 2-(2-Phenethyl-Chromone Derivative, Suppresses Innate and Adaptive Immunity via Inhibiting STAT1/3 and NF-κB Signaling Pathways

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Ran Guo

2017-05-01

Full Text Available Multiple sclerosis is a chronic inflammatory autoimmune disease of the central nervous system characterized by demyelinating plaques and axonal loss. Inhibition on over activation of innate and adaptive immunity provides a rationale strategy for treatment of multiple sclerosis. In the present study, we investigated the inhibitory effects of GYF-21, an epoxide 2-(2-phenethyl-chromone derivative isolated from Chinese agarwood, on innate and adaptive immunity for revealing its potential to treat multiple sclerosis. The results showed that GYF-21 markedly inhibited the activation of microglia, and dendritic cells as well as neutrophils, all of which play important roles in innate immunity. Furthermore, GYF-21 significantly suppressed adaptive immunity via inhibiting the differentiation of naive CD4+ T cells into T helper 1 (Th1 and T helper 17 (Th17 cells, and suppressing the activation, proliferation, and IFN-γ secretion of CD8+ T cells. The mechanism study showed that GYF-21 evidently inhibited the activation of STAT1/3 and NF-κB signaling pathways in microglia. In conclusion, we demonstrated that GYF-21 can significantly inhibit innate and adaptive immunity via suppressing STAT1/3 and NF-κB signaling pathways, and has potential to be developed into therapeutic drug for multiple sclerosis.

Diffuse noxious inhibitory controls and nerve injury: restoring an imbalance between descending monoamine inhibitions and facilitations.

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Bannister, Kirsty; Patel, Ryan; Goncalves, Leonor; Townson, Louisa; Dickenson, Anthony H

2015-09-01

Diffuse noxious inhibitory controls (DNICs) utilize descending inhibitory controls through poorly understood brain stem pathways. The human counterpart, conditioned pain modulation, is reduced in patients with neuropathy aligned with animal data showing a loss of descending inhibitory noradrenaline controls together with a gain of 5-HT3 receptor-mediated facilitations after neuropathy. We investigated the pharmacological basis of DNIC and whether it can be restored after neuropathy. Deep dorsal horn neurons were activated by von Frey filaments applied to the hind paw, and DNIC was induced by a pinch applied to the ear in isoflurane-anaesthetized animals. Spinal nerve ligation was the model of neuropathy. Diffuse noxious inhibitory control was present in control rats but abolished after neuropathy. α2 adrenoceptor mechanisms underlie DNIC because the antagonists, yohimbine and atipamezole, markedly attenuated this descending inhibition. We restored DNIC in spinal nerve ligated animals by blocking 5-HT3 descending facilitations with the antagonist ondansetron or by enhancing norepinephrine modulation through the use of reboxetine (a norepinephrine reuptake inhibitor, NRI) or tapentadol (μ-opioid receptor agonist and NRI). Additionally, ondansetron enhanced DNIC in normal animals. Diffuse noxious inhibitory controls are reduced after peripheral nerve injury illustrating the central impact of neuropathy, leading to an imbalance in descending excitations and inhibitions. Underlying noradrenergic mechanisms explain the relationship between conditioned pain modulation and the use of tapentadol and duloxetine (a serotonin, NRI) in patients. We suggest that pharmacological strategies through manipulation of the monoamine system could be used to enhance DNIC in patients by blocking descending facilitations with ondansetron or enhancing norepinephrine inhibitions, so possibly reducing chronic pain.

Electroacupuncture Improved Hippocampal Neurogenesis following Traumatic Brain Injury in Mice through Inhibition of TLR4 Signaling Pathway

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Yuqin Ye

2017-01-01

Full Text Available The protective role of electroacupuncture (EA treatment in diverse neurological diseases such as ischemic stroke is well acknowledged. However, whether and how EA act on hippocampal neurogenesis following traumatic brain injury (TBI remains poorly understood. This study aims to investigate the effect of EA on hippocampal neurogenesis and neurological functions, as well as its underlying association with toll-like receptor 4 (TLR4 signaling in TBI mice. BrdU/NeuN immunofluorescence was performed to label newborn neurons in the hippocampus after EA treatment. Water maze test and neurological severity score were used to evaluate neurological function posttrauma. The hippocampal level of TLR4 and downstream molecules and inflammatory cytokines were, respectively, detected by Western blot and enzyme-linked immunosorbent assay. EA enhanced hippocampal neurogenesis and inhibited TLR4 expression at 21, 28, and 35 days after TBI, but the beneficial effects of EA on posttraumatic neurogenesis and neurological functions were attenuated by lipopolysaccharide-induced TLR4 activation. In addition, EA exerted an inhibitory effect on both TLR4/Myd88/NF-κB and TLR4/TRIF/NF-κB pathways, as well as the inflammatory cytokine expression in the hippocampus following TBI. In conclusion, EA promoted hippocampal neurogenesis and neurological recovery through inhibition of TLR4 signaling pathway posttrauma, which may be a potential approach to improve the outcome of TBI.

Curcumin inhibited HGF-induced EMT and angiogenesis through regulating c-Met dependent PI3K/Akt/mTOR signaling pathways in lung cancer

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Demin Jiao

2016-01-01

Full Text Available The epithelial-mesenchymal transition (EMT and angiogenesis have emerged as two pivotal events in cancer progression. Curcumin has been extensively studied in preclinical models and clinical trials of cancer prevention due to its favorable toxicity profile. However, the possible involvement of curcumin in the EMT and angiogenesis in lung cancer remains unclear. This study found that curcumin inhibited hepatocyte growth factor (HGF-induced migration and EMT-related morphological changes in A549 and PC-9 cells. Moreover, pretreatment with curcumin blocked HGF-induced c-Met phosphorylation and downstream activation of Akt, mTOR, and S6. These effects mimicked that of c-Met inhibitor SU11274 or PI3 kinase inhibitor LY294002 or mTOR inhibitor rapamycin treatment. c-Met gene overexpression analysis further demonstrated that curcumin suppressed lung cancer cell EMT by inhibiting c-Met/Akt/mTOR signaling pathways. In human umbilical vein endothelial cells (HUVECs, we found that curcumin also significantly inhibited PI3K/Akt/mTOR signaling and induced apoptosis and reduced migration and tube formation of HGF-treated HUVEC. Finally, in the experimental mouse model, we showed that curcumin inhibited HGF-stimulated tumor growth and induced an increase in E-cadherin expression and a decrease in vimentin, CD34, and vascular endothelial growth factor (VEGF expression. Collectively, these findings indicated that curcumin could inhibit HGF-promoted EMT and angiogenesis by targeting c-Met and blocking PI3K/Akt/mTOR pathways.

Forchlorfenuron disrupts SEPT9_i1 filaments and inhibits HIF-1.

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Dikla Vardi-Oknin

Full Text Available Forchlorfenuron (FCF is a synthetic plant cytokinin that has been shown to alter yeast and mammalian septin organization. Septins are a highly conserved family of GTP-binding cytoskeletal proteins. Mammalian septins are involved in diverse cellular processes including tumorigenesis. We have been studying the interaction between septin 9 isoform 1 (SEPT9_i1 and hypoxia inducible factor-1α (HIF-1α, the oxygen regulated subunit of HIF-1. HIF-1 is a key transcription factor in the hypoxic responses pathway, and its activation has been observed in carcinogenesis and numerous cancers. SEPT9_i1/HIF-1α interaction plays an important role in upregulation of HIF-1 transcriptional activity by preventing HIF-1α's ubiquitination and degradation leading to increased tumor growth and angiogenesis. We tested the hypothesis whether FCF affects SEPT9_i1 filamentous structures and consequently HIF-1 pathway in cancer cells. We showed that FCF suppresses tumorigenic properties, including proliferation, migration and transformation, in prostate cancer cells. FCF did not alter SEPT9_i1 steady state protein expression levels but it affected its filamentous structures and subcellular localization. FCF induced degradation of HIF-1α protein in a dose- and time-dependent manner. This inhibition was also shown in other common cancer types tested. Rapid degradation of HIF-1α protein levels was accompanied by respective inhibition in HIF-1α transcriptional activity. Moreover, HIF-1α protein half-life was markedly decreased in the presence of FCF compared with that in the absence of FCF. The FCF-induced degradation of HIF-1α was mediated in a significant part via the proteasome. To the best of our knowledge, this is the first demonstration of specific manipulation of septin filaments by pharmacological means having downstream inhibitory effects on the HIF-1 pathway.

Honey bee dopamine and octopamine receptors linked to intracellular calcium signaling have a close phylogenetic and pharmacological relationship.

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Kyle T Beggs

Full Text Available BACKGROUND: Three dopamine receptor genes have been identified that are highly conserved among arthropod species. One of these genes, referred to in honey bees as Amdop2, shows a close phylogenetic relationship to the a-adrenergic-like octopamine receptor family. In this study we examined in parallel the functional and pharmacological properties of AmDOP2 and the honey bee octopamine receptor, AmOA1. For comparison, pharmacological properties of the honey bee dopamine receptors AmDOP1 and AmDOP3, and the tyramine receptor AmTYR1, were also examined. METHODOLOGY/PRINCIPAL FINDINGS: Using HEK293 cells heterologously expressing honey bee biogenic amine receptors, we found that activation of AmDOP2 receptors, like AmOA1 receptors, initiates a rapid increase in intracellular calcium levels. We found no evidence of calcium signaling via AmDOP1, AmDOP3 or AmTYR1 receptors. AmDOP2- and AmOA1-mediated increases in intracellular calcium were inhibited by 10 µM edelfosine indicating a requirement for phospholipase C-β activity in this signaling pathway. Edelfosine treatment had no effect on AmDOP2- or AmOA1-mediated increases in intracellular cAMP. The synthetic compounds mianserin and epinastine, like cis-(Z-flupentixol and spiperone, were found to have significant antagonist activity on AmDOP2 receptors. All 4 compounds were effective antagonists also on AmOA1 receptors. Analysis of putative ligand binding sites offers a possible explanation for why epinastine acts as an antagonist at AmDOP2 receptors, but fails to block responses mediated via AmDOP1. CONCLUSIONS/SIGNIFICANCE: Our results indicate that AmDOP2, like AmOA1, is coupled not only to cAMP, but also to calcium-signalling and moreover, that the two signalling pathways are independent upstream of phospholipase C-β activity. The striking similarity between the pharmacological properties of these 2 receptors suggests an underlying conservation of structural properties related to receptor

Pentacyclic Triterpenoids Inhibit IKKβ Mediated Activation of NF-κB Pathway: In Silico and In Vitro Evidences.

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Kalpesh R Patil

Full Text Available Pentacyclic Triterpenoids (PTs and their analogues as well as derivatives are emerging as important drug leads for various diseases. They act through a variety of mechanisms and a majority of them inhibit the nuclear factor kappa-beta (NF-κB signaling pathway. In this study, we examined the effects of the naturally occurring PTs on IκB kinase-β (IKKβ, which has great scientific relevance in the NF-κB signaling pathway. On virtual screening, 109 PTs were screened through the PASS (prediction of activity spectra of substances software for prediction of NF-κB inhibitory activity followed by docking on the NEMO/IKKβ association complex (PDB: 3BRV and testing for compliance with the softened Lipinski's Rule of Five using Schrodinger (LLC, New York, USA. Out of the projected 45 druggable PTs, Corosolic Acid (CA, Asiatic Acid (AA and Ursolic Acid (UA were assayed for IKKβ kinase activity in the cell free medium. The UA exhibited a potent IKKβ inhibitory effect on the hotspot kinase assay with IC50 of 69 μM. Whereas, CA at 50 μM concentration markedly reduced the NF-κB luciferase activity and phospho-IKKβ protein expressions. The PTs tested, attenuated the expression of the NF-κB cascade proteins in the LPS-stimulated RAW 264.7 cells, prevented the phosphorylation of the IKKα/β and blocked the activation of the Interferon-gamma (IFN-γ. The results suggest that the IKKβ inhibition is the major mechanism of the PTs-induced NF-κB inhibition. PASS predictions along with in-silico docking against the NEMO/IKKβ can be successfully applied in the selection of the prospective NF-κB inhibitory downregulators of IKKβ phosphorylation.

Inhibition of the Rho/ROCK pathway prevents neuronal degeneration in vitro and in vivo following methylmercury exposure

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Fujimura, Masatake; Usuki, Fusako; Kawamura, Miwako; Izumo, Shuji

2011-01-01

Methylmercury (MeHg) is an environmental neurotoxicant which induces neuropathological changes in both the central nervous and peripheral sensory nervous systems. Our recent study demonstrated that down-regulation of Ras-related C3 botulinum toxin substrate 1 (Rac1), which is known to promote neuritic extension, preceded MeHg-induced damage in cultured cortical neurons, suggesting that MeHg-mediated axonal degeneration is due to the disturbance of neuritic extension. Therefore we hypothesized that MeHg-induced axonal degeneration might be caused by neuritic extension/retraction incoordination. This idea brought our attention to the Ras homolog gene (Rho)/Rho-associated coiled coil-forming protein kinase (ROCK) pathway because it has been known to be associated with the development of axon and apoptotic neuronal cell death. Here we show that inhibition of the Rho/ROCK pathway prevents MeHg-intoxication both in vitro and in vivo. A Rho inhibitor, C3 toxin, and 2 ROCK inhibitors, Fasudil and Y-27632, significantly protected against MeHg-induced axonal degeneration and apoptotic neuronal cell death in cultured cortical neuronal cells exposed to 100 nM MeHg for 3 days. Furthermore, Fasudil partially prevented the loss of large pale neurons in dorsal root ganglia, axonal degeneration in dorsal spinal root nerves, and vacuolar degeneration in the dorsal columns of the spinal cord in MeHg-intoxicated model rats (20 ppm MeHg in drinking water for 28 days). Hind limb crossing sign, a characteristic MeHg-intoxicated sign, was significantly suppressed in this model. The results suggest that inhibition of the Rho/ROCK pathway rescues MeHg-mediated neuritic extension/retraction incoordination and is effective for the prevention of MeHg-induced axonal degeneration and apoptotic neuronal cell death.

Role of Spm-Cer-S1P signalling pathway in MMP-2 mediated U46619-induced proliferation of pulmonary artery smooth muscle cells: protective role of epigallocatechin-3-gallate.

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Chowdhury, Animesh; Sarkar, Jaganmay; Chakraborti, Tapati; Chakraborti, Sajal

2015-10-01

During remodelling of pulmonary artery, marked proliferation of pulmonary artery smooth muscle cells (PASMCs) occurs, which contributes to pulmonary hypertension. Thromboxane A2 (TxA2) has been shown to produce pulmonary hypertension. The present study investigates the inhibitory effect of epigallocatechin-3-gallate (EGCG) on the TxA2 mimetic, U46619-induced proliferation of PASMCs. U46619 at a concentration of 10 nM induces maximum proliferation of bovine PASMCs. Both pharmacological and genetic inhibitors of p(38)MAPK, NF-κB and MMP-2 significantly inhibit U46619-induced cell proliferation. EGCG markedly abrogate U46619-induced p(38)MAPK phosphorylation, NF-κB activation, proMMP-2 expression and activation, and also the cell proliferation. U46619 causes an increase in the activation of sphingomyelinase (SMase) and sphingosine kinase (SPHK) and also increase sphingosine 1 phosphate (S1P) level. U46619 also induces phosphorylation of ERK1/2, which phosphorylates SPHK leading to an increase in S1P level. Both pharmacological and genetic inhibitors of SMase and SPHK markedly inhibit U46619-induced cell proliferation. Additionally, pharmacological and genetic inhibitors of MMP-2 markedly abrogate U46619-induced SMase activity and S1P level. EGCG markedly inhibit U46619-induced SMase activity, ERK1/2 and SPHK phosphorylation and S1P level in the cells. Overall, Sphingomyeline-Ceramide-Sphingosine-1-phosphate (Spm-Cer-S1P) signalling axis plays an important role in MMP-2 mediated U46619-induced proliferation of PASMCs. Importantly, EGCG inhibits U46619 induced increase in MMP-2 activation by modulating p(38)MAPK-NFκB pathway and subsequently prevents the cell proliferation. Copyright © 2015 John Wiley & Sons, Ltd.

Melatonin enhances the anti-tumor effect of fisetin by inhibiting COX-2/iNOS and NF-κB/p300 signaling pathways.

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Canhui Yi

Full Text Available Melatonin is a hormone identified in plants and pineal glands of mammals and possesses diverse physiological functions. Fisetin is a bio-flavonoid widely found in plants and exerts antitumor activity in several types of human cancers. However, the combinational effect of melatonin and fisetin on antitumor activity, especially in melanoma treatment, remains unclear. Here, we tested the hypothesis that melatonin could enhance the antitumor activity of fisetin in melanoma cells and identified the underlying molecular mechanisms. The combinational treatment of melanoma cells with fisetin and melatonin significantly enhanced the inhibitions of cell viability, cell migration and clone formation, and the induction of apoptosis when compared with the treatment of fisetin alone. Moreover, such enhancement of antitumor effect by melatonin was found to be mediated through the modulation of the multiply signaling pathways in melanoma cells. The combinational treatment of fisetin with melatonin increased the cleavage of PARP proteins, triggered more release of cytochrome-c from the mitochondrial inter-membrane, enhanced the inhibition of COX-2 and iNOS expression, repressed the nuclear localization of p300 and NF-κB proteins, and abrogated the binding of NF-κB on COX-2 promoter. Thus, these results demonstrated that melatonin potentiated the anti-tumor effect of fisetin in melanoma cells by activating cytochrome-c-dependent apoptotic pathway and inhibiting COX-2/iNOS and NF-κB/p300 signaling pathways, and our study suggests the potential of such a combinational treatment of natural products in melanoma therapy.

Melatonin Enhances the Anti-Tumor Effect of Fisetin by Inhibiting COX-2/iNOS and NF-κB/p300 Signaling Pathways

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Yu, Zhenlong; Xiao, Yao; Wang, Jingshu; Qiu, Huijuan; Yu, Wendan; Tang, Ranran; Yuan, Yuhui; Guo, Wei; Deng, Wuguo

2014-01-01

Melatonin is a hormone identified in plants and pineal glands of mammals and possesses diverse physiological functions. Fisetin is a bio-flavonoid widely found in plants and exerts antitumor activity in several types of human cancers. However, the combinational effect of melatonin and fisetin on antitumor activity, especially in melanoma treatment, remains unclear. Here, we tested the hypothesis that melatonin could enhance the antitumor activity of fisetin in melanoma cells and identified the underlying molecular mechanisms. The combinational treatment of melanoma cells with fisetin and melatonin significantly enhanced the inhibitions of cell viability, cell migration and clone formation, and the induction of apoptosis when compared with the treatment of fisetin alone. Moreover, such enhancement of antitumor effect by melatonin was found to be mediated through the modulation of the multiply signaling pathways in melanoma cells. The combinational treatment of fisetin with melatonin increased the cleavage of PARP proteins, triggered more release of cytochrome-c from the mitochondrial inter-membrane, enhanced the inhibition of COX-2 and iNOS expression, repressed the nuclear localization of p300 and NF-κB proteins, and abrogated the binding of NF-κB on COX-2 promoter. Thus, these results demonstrated that melatonin potentiated the anti-tumor effect of fisetin in melanoma cells by activating cytochrome-c-dependent apoptotic pathway and inhibiting COX-2/iNOS and NF-κB/p300 signaling pathways, and our study suggests the potential of such a combinational treatment of natural products in melanoma therapy. PMID:25000190

Double-edged swords as cancer therapeutics: novel, orally active, small molecules simultaneously inhibit p53-MDM2 interaction and the NF-κB pathway.

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Zhuang, Chunlin; Miao, Zhenyuan; Wu, Yuelin; Guo, Zizhao; Li, Jin; Yao, Jianzhong; Xing, Chengguo; Sheng, Chunquan; Zhang, Wannian

2014-02-13

Simultaneous inactivation of p53 and hyperactivation of nuclear factor-κB (NF-κB) is a common occurrence in human cancer. Currently, antitumor agents are being designed to selectively activate p53 or inhibit NF-κB. However, there is no concerted effort yet to deliberately design inhibitors that can simultaneously do both. This paper provided a proof-of-concept study that p53-MDM2 interaction and NF-κB pathway can be simultaneously targeted by a small-molecule inhibitor. A series of pyrrolo[3,4-c]pyrazole derivatives were rationally designed and synthesized as the first-in-class inhibitors of p53-MDM2 interaction and NF-κB pathway. Most of the compounds were identified to possess nanomolar p53-MDM2 inhibitory activity. Compounds 5q and 5s suppressed NF-κB activation through inhibition of IκBα phosphorylation and elevation of the cytoplasmic levels of p65 and phosphorylated IKKα/β. Biochemical assay for the kinases also supported the fact that pyrrolo[3,4-c]pyrazole compounds directly targeted the NF-κB pathway. In addition, four compounds (5j, 5q, 5s, and 5u) effectively inhibited tumor growth in the A549 xenograft model. Further pharmacokinetic study revealed that compound 5q exhibited excellent oral bioavailability (72.9%).

A phosphoinositide 3-kinase (PI3K)-serum- and glucocorticoid-inducible kinase 1 (SGK1) pathway promotes Kv7.1 channel surface expression by inhibiting Nedd4-2 protein

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Andersen, Martin Nybo; Krzystanek, Katarzyna; Petersen, Frederic

2013-01-01

Epithelial cell polarization involves several kinase signaling cascades that eventually divide the surface membrane into an apical and a basolateral part. One kinase, which is activated during the polarization process, is phosphoinositide 3-kinase (PI3K). In MDCK cells, the basolateral potassium...... channel Kv7.1 requires PI3K activity for surface-expression during the polarization process. Here, we demonstrate that Kv7.1 surface expression requires tonic PI3K activity as PI3K inhibition triggers endocytosis of these channels in polarized MDCK. Pharmacological inhibition of SGK1 gave similar results...... as PI3K inhibition, whereas overexpression of constitutively active SGK1 overruled it, suggesting that SGK1 is the primary downstream target of PI3K in this process. Furthermore, knockdown of the ubiquitin ligase Nedd4-2 overruled PI3K inhibition, whereas a Nedd4-2 interaction-deficient Kv7.1 mutant...

Tomatidine enhances lifespan and healthspan in C. elegans through mitophagy induction via the SKN-1/Nrf2 pathway

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Fang, Evandro Fei; Waltz, Tyler B; Kassahun, Henok

2017-01-01

in human aging. Tomatidine, a natural compound abundant in unripe tomatoes, inhibits age-related skeletal muscle atrophy in mice. Here we show that tomatidine extends lifespan and healthspan in C. elegans, an animal model of aging which shares many major longevity pathways with mammals. Tomatidine improves...... many C. elegans behaviors related to healthspan and muscle health, including increased pharyngeal pumping, swimming movement, and reduced percentage of severely damaged muscle cells. Microarray, imaging, and behavioral analyses reveal that tomatidine maintains mitochondrial homeostasis by modulating...... occurs in C. elegans, primary rat neurons, and human cells. Our data suggest that tomatidine may delay some physiological aspects of aging, and points to new approaches for pharmacological interventions for diseases of aging....

Multiple pathways of sigma(1) receptor ligand uptakes into primary cultured neuronal cells.

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Yamamoto, H; Karasawa, J; Sagi, N; Takahashi, S; Horikomi, K; Okuyama, S; Nukada, T; Sora, I; Yamamoto, T

2001-08-03

Although many antipsychotics have affinities for sigma receptors, the transportation pathway of exogenous sigma(1) receptor ligands to intracellular type-1 sigma receptors are not fully understood. In this study, sigma(1) receptor ligand uptakes were studied using primary cultured neuronal cells. [(3)H](+)-pentazocine and [(3)H](R)-(+)-1-(4-chlorophenyl)-3-[4-(2-methoxyethyl)piperazin-1-yl]methyl-2-pyrrolidinone L-tartrate (MS-377), used as a selective sigma(1) receptor ligands, were taken up in a time-, energy- and temperature-dependent manner, suggesting that active transport mechanisms were involved in their uptakes. sigma(1) receptor ligands taken up into primary cultured neuronal cells were not restricted to agonists, but also concerned antagonists. The uptakes of these ligands were mainly Na(+)-independent. Kinetic analysis of [(3)H](+)-pentazocine and [(3)H]MS-377 uptake showed K(m) values (microM) of 0.27 and 0.32, and V(max) values (pmol/mg protein/min) of 17.4 and 9.4, respectively. Although both ligands were incorporated, the pharmacological properties of these two ligands were different. Uptake of [(3)H](+)-pentazocine was inhibited in the range 0.4-7.1 microM by all the sigma(1) receptor ligands used, including N,N-dipropyl-2-[4-methoxy-3-(2-phenylethoxy)phenyl]ethylamine monohydrochloride (NE-100), a selective sigma(1) receptor ligand. In contrast, the inhibition of [(3)H]MS-377 uptake was potently inhibited by haloperidol, characterized by supersensitivity (IC(50), approximately 2 nM) and was inhibited by NE-100 with low sensitivity (IC(50), 4.5 microM). Moreover, kinetic analysis revealed that NE-100 inhibited [(3)H]MS-377 uptake in a noncompetitive manner, suggesting that NE-100 acted at a site different from the uptake sites of [(3)H]MS-377. These findings suggest that there are at least two uptake pathways for sigma(1) receptor ligands in primary cultured neuronal cells (i.e. a haloperidol-sensitive pathway and another, unclear, pathway). In

MAPK signaling pathways and HDAC3 activity are disrupted during differentiation of emerin-null myogenic progenitor cells

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Carol M. Collins

2017-04-01

Full Text Available Mutations in the gene encoding emerin cause Emery–Dreifuss muscular dystrophy (EDMD. Emerin is an integral inner nuclear membrane protein and a component of the nuclear lamina. EDMD is characterized by skeletal muscle wasting, cardiac conduction defects and tendon contractures. The failure to regenerate skeletal muscle is predicted to contribute to the skeletal muscle pathology of EDMD. We hypothesize that muscle regeneration defects are caused by impaired muscle stem cell differentiation. Myogenic progenitors derived from emerin-null mice were used to confirm their impaired differentiation and analyze selected myogenic molecular pathways. Emerin-null progenitors were delayed in their cell cycle exit, had decreased myosin heavy chain (MyHC expression and formed fewer myotubes. Emerin binds to and activates histone deacetylase 3 (HDAC3. Here, we show that theophylline, an HDAC3-specific activator, improved myotube formation in emerin-null cells. Addition of the HDAC3-specific inhibitor RGFP966 blocked myotube formation and MyHC expression in wild-type and emerin-null myogenic progenitors, but did not affect cell cycle exit. Downregulation of emerin was previously shown to affect the p38 MAPK and ERK/MAPK pathways in C2C12 myoblast differentiation. Using a pure population of myogenic progenitors completely lacking emerin expression, we show that these pathways are also disrupted. ERK inhibition improved MyHC expression in emerin-null cells, but failed to rescue myotube formation or cell cycle exit. Inhibition of p38 MAPK prevented differentiation in both wild-type and emerin-null progenitors. These results show that each of these molecular pathways specifically regulates a particular stage of myogenic differentiation in an emerin-dependent manner. Thus, pharmacological targeting of multiple pathways acting at specific differentiation stages may be a better therapeutic approach in the future to rescue muscle regeneration in vivo.

Odanacatib Inhibits Resistin-induced Hypertrophic H9c2 Cardiomyoblast Cells Through LKB1/AMPK Pathway

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Xian Zheng

2017-08-01

Full Text Available ABSTRACT Odanacatib (ODN is a selective inhibitor of cathepsin K. The cysteine protease cathepsin K has been implicated in cardiac hypertrophy. Resistine is an adipokine which is identified to promote cardiac hypertrophy. Here, we hypothesize that ODN mitigates resistin-induced myocyte hypertrophy. Cell surface area and protein synthesis were measured after treatment with resistin and ODN in H9c2 cells. The expression of cardiomyocyte hypertrophy marker BNP and β-MHC was detected by RT-qPCR. The expression and phosphorylation of AMPK and LKB1 were analyzed with Western blot. Resistin could significantly increase cardiomyocyte cell surface area, protein synthesis, and embryonic gene BNP and β-MHC expression, inhibit phosphorylation of AMPK and LKB1. ODN could significantly reverse the effects of resistin. Collectively, our data suggest that ODN can inhibit cardiomyocyte hypertrophy induced by resistin and the underlying mechanism may be involved in LKB1/AMPK pathway.

Centchroman inhibits proliferation of head and neck cancer cells through the modulation of PI3K/mTOR Pathway

International Nuclear Information System (INIS)

Srivastava, Vikas Kumar; Gara, Rishi Kumar; Bhatt, M.L.B.; Sahu, D.P.; Mishra, Durga Prasad

2011-01-01

Research highlights: → Centchroman (CC) inhibits cellular proliferation in HNSCC cells through the dual inhibition of PI3/mTOR pathway. → CC treatment also inhibits STAT3 activation and alters expression of proteins involved in cell cycle regulation and DNA repair response in HNSCC cells. → CC exhibits anti-proliferative activity in a variety of non-HNSCC cancer cell lines and is devoid of cytotoxicity to normal cell types of diverse origins. -- Abstract: Centchroman (CC; 67/20; INN: Ormeloxifene) is a non-steroidal antiestrogen extensively used as a female contraceptive in India. In the present study, we report the anti-proliferative effect of CC in head and neck squamous cell carcinoma (HNSCC) cells. CC inhibited cell proliferation in a dose dependent manner at 24 h of treatment. Further studies showed that CC treatment induced apoptosis, inhibited Akt/mTOR and signal transducers and activators of transcription protein 3 (STAT3) signaling, altered proteins associated with cell cycle regulation and DNA damage and inhibited colony forming efficiency of HNSCC cells. In addition, CC displayed anti-proliferative activity against a variety of non-HNSCC cell lines of diverse origin. The ability of CC to serve as a dual-inhibitor of Akt/mTOR and STAT3 signaling warrants further studies into its role as a therapeutic strategy against HNSCC.

NFAT5 regulates the canonical Wnt pathway and is required for cardiomyogenic differentiation

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Adachi, Atsuo; Takahashi, Tomosaburo; Ogata, Takehiro; Imoto-Tsubakimoto, Hiroko; Nakanishi, Naohiko; Ueyama, Tomomi; Matsubara, Hiroaki

2012-01-01

Highlights: ► NFAT5 protein expression is downregulated during cardiomyogenesis. ► Inhibition of NFAT5 function suppresses canonical Wnt signaling. ► Inhibition of NFAT5 function attenuates mesodermal induction. ► NFAT5 function is required for cardiomyogenesis. -- Abstract: While nuclear factor of activated T cells 5 (NFAT5), a transcription factor implicated in osmotic stress response, is suggested to be involved in other processes such as migration and proliferation, its role in cardiomyogenesis is largely unknown. Here, we examined the role of NFAT5 in cardiac differentiation of P19CL6 cells, and observed that it was abundantly expressed in undifferentiated P19CL6 cells, and its protein expression was significantly downregulated by enhanced proteasomal degradation during DMSO-induced cardiomyogenesis. Expression of a dominant negative mutant of NFAT5 markedly attenuated cardiomyogenesis, which was associated with the inhibition of mesodermal differentiation. TOPflash reporter assay revealed that the transcriptional activity of canonical Wnt signaling was activated prior to mesodermal differentiation, and this activation was markedly attenuated by NFAT5 inhibition. Pharmacological activation of canonical Wnt signaling by [2′Z, 3′E]-6-bromoindirubin-3′-oxime (BIO) restored Brachyury expression in NFAT5DN-expressing cells. Inhibition of NFAT5 markedly attenuated Wnt3 and Wnt3a induction. Expression of Dkk1 and Cerberus1, which are secreted Wnt antagonists, was also inhibited by NFAT5 inhibition. Thus, endogenous NFAT5 regulates the coordinated expression of Wnt ligands and antagonists, which are essential for cardiomyogenesis through the canonical Wnt pathway. These results demonstrated a novel role of NFAT5 in cardiac differentiation of stem cells.

Tanshinone IIA attenuates neuropathic pain via inhibiting glial activation and immune response.

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Cao, Fa-Le; Xu, Min; Wang, Yan; Gong, Ke-Rui; Zhang, Jin-Tao

2015-01-01

Neuropathic pain, characterized by spontaneous pain, hyperalgesia and allodynia, is a devastating neurological disease that seriously affects patients' quality of life. We have previously shown that tanshinone IIA (TIIA), an important lipophilic component of Danshen, had significant anti-nociceptive effect in somatic and visceral pain, it is surprisingly noted that few pharmacological studies have been carried out to explore the possible analgesic action of TIIA on neuropathic pain and the underlying mechanisms. Therefore, in the present study, by using spinal nerve ligation (SNL) pain model, the antinociceptive and antihyperalgesic effects of TIIA on neuropathic pain were evaluated by intraperitoneal administration in rats. The results indicated that TIIA dose-dependently inhibited SNL-induced mechanical hyperalgesia. As revealed by OX42 levels, TIIA effectively repressed the activation of spinal microglial activation in SNL-induced neuropathic pain. Meanwhile, TIIA also decreased the expressions of inflammatory cytokines TNF-α and IL-1β in the spinal cord. Furthermore, TIIA inhibited oxidative stress by significantly rescuing the superoxide dismutase (SOD) activity and decreasing the malondialdehyde (MDA). Moreover, TIIA depressed SNL-induced MAPKs activation in spinal cord. Taken together, our study provides evidence that TIIA inhibited SNL-induced neuropathic pain through depressing microglial activation and immune response by the inhibition of mitogen-activated protein kinases (MAPKs) pathways. Our findings suggest that TIIA might be a promising agent in the treatment of neuropathic pain. Copyright © 2014 Elsevier Inc. All rights reserved.

Pharmacological inhibition of radiation induced in vitro tumor cell/endothelium cell interactions and in vivo metastasis processes

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Herzog, Melanie

2013-01-01

extravasation of circulating tumor cells in vivo. These pro-metastatic radiation effects could be attenuated by pharmacological inhibition of Rho-regulated signaling.

Honokiol inhibits sphere formation and xenograft growth of oral cancer side population cells accompanied with JAK/STAT signaling pathway suppression and apoptosis induction

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Huang, Jhy-Shrian; Yao, Chih-Jung; Chuang, Shuang-En; Yeh, Chi-Tai; Lee, Liang-Ming; Chen, Ruei-Ming; Chao, Wan-Ju; Whang-Peng, Jacqueline; Lai, Gi-Ming

2016-01-01

Eliminating cancer stem cells (CSCs) has been suggested for prevention of tumor recurrence and metastasis. Honokiol, an active compound of Magnolia officinalis, had been proposed to be a potential candidate drug for cancer treatment. We explored its effects on the elimination of oral CSCs both in vitro and in vivo. By using the Hoechst side population (SP) technique, CSCs-like SP cells were isolated from human oral squamous cell carcinoma (OSCC) cell lines, SAS and OECM-1. Effects of honokiol on the apoptosis and signaling pathways of SP-derived spheres were examined by Annexin V/Propidium iodide staining and Western blotting, respectively. The in vivo effectiveness was examined by xenograft mouse model and immunohistochemical tissue staining. The SP cells possessed higher stemness marker expression (ABCG2, Ep-CAM, Oct-4 and Nestin), clonogenicity, sphere formation capacity as well as tumorigenicity when compared to the parental cells. Treatment of these SP-derived spheres with honokiol resulted in apoptosis induction via Bax/Bcl-2 and caspase-3-dependent pathway. This apoptosis induction was associated with marked suppression of JAK2/STAT3, Akt and Erk signaling pathways in honokiol-treated SAS spheres. Consistent with its effect on JAK2/STAT3 suppression, honokiol also markedly inhibited IL-6-mediated migration of SAS cells. Accordingly, honokiol dose-dependently inhibited the growth of SAS SP xenograft and markedly reduced the immunohistochemical staining of PCNA and endothelial marker CD31 in the xenograft tumor. Honokiol suppressed the sphere formation and xenograft growth of oral CSC-like cells in association with apoptosis induction and inhibition of survival/proliferation signaling pathways as well as angiogenesis. These results suggest its potential as an integrative medicine for combating oral cancer through targeting on CSCs. The online version of this article (doi:10.1186/s12885-016-2265-6) contains supplementary material, which is available to

H2O2 treatment or serum deprivation induces autophagy and apoptosis in naked mole-rat skin fibroblasts by inhibiting the PI3K/Akt signaling pathway.

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Zhao, Shanmin; Li, Li; Wang, Shiyong; Yu, Chenlin; Xiao, Bang; Lin, Lifang; Cong, Wei; Cheng, Jishuai; Yang, Wenjing; Sun, Wei; Cui, Shufang

2016-12-20

Naked mole-rats (NMR; Heterocephalus glaber) display extreme longevity and resistance to cancer. Here, we examined whether autophagy contributes to the longevity of NMRs by assessing the effects of the PI3K/Akt pathway inhibitor LY294002 and the autophagy inhibitor chloroquine (CQ) on autophagy and apoptosis in NMR skin fibroblasts. Serum starvation, H2O2 treatment, and LY294002 treatment all increased the LC3-II/LC3-I ratio and numbers of double-membraned autophagosomes and autophagic vacuoles, and decreased levels of p70S6K, p-AktSer473, and p-AktThr308. By contrast, CQ treatment decreased p70S6K, AktSer473, and AktThr308 levels. The Bax/Bcl-2 ratio increased after 12 h of exposure to LY294002 or CQ. These data show that inhibiting the Akt pathway promotes autophagy and apoptosis in NMR skin fibroblasts. Furthermore, LY294002 or CQ treatment decreased caspase-3, p53, and HIF1-α levels, suggesting that serum starvation or H2O2 treatment increase autophagy and apoptosis in NMR skin fibroblasts by inhibiting the PI3K/Akt pathway. CQ-induced inhibition of late autophagy stages also prevented Akt activation and induced apoptosis. Finally, the HIF-1α and p53 pathways were involved in serum starvation- or H2O2-induced autophagy in NMR skin fibroblasts.

Deubiquitinase inhibitor b-AP15 activates endoplasmic reticulum (ER) stress and inhibits Wnt/Notch1 signaling pathway leading to the reduction of cell survival in hepatocellular carcinoma cells.

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Ding, Youming; Chen, Xiaoyan; Wang, Bin; Yu, Bin; Ge, Jianhui

2018-04-15

b-AP15, a potent and selective inhibitor of the ubiquitin-specific peptidase 14 (USP14), displays in vitro and in vivo antitumor abilities on some types of cancer cells. However, the mechanism underlying its action is not well elucidated. The purposes of the present study are to observe the potential impacts of b-AP15 on cell survival of hepatocellular carcinoma cells and to investigate whether and how this compound inhibits some survival-promoting signaling pathways. We found that b-AP15 significantly decreased cell viability and increased cell apoptosis in a dose-dependent manner in hepatocellular carcinoma cells, along with the perturbation of cell cycle and the decreased expressions of cell cycle-related proteins. We also demonstrated that the endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) were enhanced by b-AP15 supplementation. The inhibition of ER stress/UPR only partly attenuated the cytotoxicity of b-AP15 on hepatocellular carcinoma cells. In addition, b-AP15 treatment inhibited Wnt/β-catenin and Notch1 signaling pathways, and suppressed phosphorylation of STAT3, Akt, and Erk1/2, which were not restored by the inhibition of ER stress/UPR. Furthermore, the expression levels of signaling molecules in Notch1 were reduced by specific inhibitor of Wnt/β-catenin pathway. Notably, either Wnt or Notch1 signaling inhibitor mitigated phosphorylation of STAT3, Akt, and Erk1/2, and mimicked the cytotoxicity of b-AP15 on hepatocellular carcinoma cells. These results clearly indicate that b-AP15 induced cytotoxic response to hepatocellular carcinoma cells by augmenting ER stress/UPR and inhibiting Wnt/Notch1 signaling pathways. This new finding provides a novel mechanism by which b-AP15 produces its antitumor therapeutic effects. Copyright © 2018 Elsevier B.V. All rights reserved.

Inhibition of nuclear factor kappa-B signaling reduces growth in medulloblastoma in vivo

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Deckard Lindsey A

2011-04-01

Full Text Available Abstract Background Medulloblastoma is a highly malignant pediatric brain tumor that requires surgery, whole brain and spine irradiation, and intense chemotherapy for treatment. A more sophisticated understanding of the pathophysiology of medulloblastoma is needed to successfully reduce the intensity of treatment and improve outcomes. Nuclear factor kappa-B (NFκB is a signaling pathway that controls transcriptional activation of genes important for tight regulation of many cellular processes and is aberrantly expressed in many types of cancer. Methods To test the importance of NFκB to medulloblastoma cell growth, the effects of multiple drugs that inhibit NFκB, pyrrolidine dithiocarbamate, diethyldithiocarbamate, sulfasalazine, curcumin and bortezomib, were studied in medulloblastoma cell lines compared to a malignant glioma cell line and normal neurons. Expression of endogenous NFκB was investigated in cultured cells, xenograft flank tumors, and primary human tumor samples. A dominant negative construct for the endogenous inhibitor of NFκB, IκB, was prepared from medulloblastoma cell lines and flank tumors were established to allow specific pathway inhibition. Results We report high constitutive activity of the canonical NFκB pathway, as seen by Western analysis of the NFκB subunit p65, in medulloblastoma tumors compared to normal brain. The p65 subunit of NFκB is extremely highly expressed in xenograft tumors from human medulloblastoma cell lines; though, conversely, the same cells in culture have minimal expression without specific stimulation. We demonstrate that pharmacological inhibition of NFκB in cell lines halts proliferation and leads to apoptosis. We show by immunohistochemical stain that phosphorylated p65 is found in the majority of primary tumor cells examined. Finally, expression of a dominant negative form of the endogenous inhibitor of NFκB, dnIκB, resulted in poor xenograft tumor growth, with average tumor volumes

Investigating the Et-1/SphK/S1P Pathway as a Novel Approach for the Prevention of Inflammation-Induced Preterm Birth.

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Giusto, Kiersten; Ashby, Charles R

2018-01-30

Preterm birth (PTB), defined as birth before 37 completed weeks of gestation, occurs in up to 18 percent of births worldwide and accounts for the majority of perinatal morbidity and mortality. While the single most common cause of PTB has been identified as inflammation, safe and effective pharmacotherapy to prevent PTB has yet to be developed. Our group has used an in vivo model of inflammation driven PTB, biochemical methods, pharmacological approaches, a novel endothelin receptor antagonist that we synthesized and RNA knockdown to help establish the role of endothelin-1 (ET-1) in inflammation-associated PTB. Further, we have used our in vivo model to test whether sphingosine kinase, which acts downstream of ET-1, plays a role in PTB. We have shown that levels of endothelin converting enzyme-1 (ECE-1) and ET-1 are increased when PTB is induced in timed pregnant mice with lipopolysaccharide (LPS) and that blocking ET-1 action, pharmacologically or using ECE-1 RNA silencing, rescues LPS-induced mice from PTB. ET-1 activates the sphingosine kinase/sphingosine-1-phosphate (SphK/S1P) pathway. S1P, in turn, is an important signaling molecule in the pro-inflammatory response. Interestingly, we have shown that SphK inhibition also prevents LPS-induced PTB in timed pregnant mice. Further, we showed that SphK inhibition suppresses the ECE-1/ET-1 axis, implicating positive feedback regulation of the SphK/S1P/ECE-1/ET-1 axis. The ET-1/SphK/SIP pathway is a potential pharmacotherapeutic target for the prevention of PTB. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

SC1 Promotes MiR124-3p Expression to Maintain the Self-Renewal of Mouse Embryonic Stem Cells by Inhibiting the MEK/ERK Pathway.

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Wei, Qing; Liu, Hongliang; Ai, Zhiying; Wu, Yongyan; Liu, Yingxiang; Shi, Zhaopeng; Ren, Xuexue; Guo, Zekun

2017-01-01