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Sample records for inhibits mechanically induced

  1. Mechanisms of caffeine-induced inhibition of UVB carcinogenesis

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    Allan H Conney

    2013-06-01

    Full Text Available Sunlight-induced nonmelanoma skin cancer is the most prevalent cancer in the United States with more than 2 million cases per year. Several studies have shown an inhibitory effect of caffeine administration on UVB-induced skin cancer in mice, and these studies are paralleled by epidemiology studies that indicate an inhibitory effect of coffee drinking on nonmelanoma skin cancer in humans. Strikingly, decaffeinated coffee consumption had no such inhibitory effect.Mechanism studies indicate that caffeine has a sunscreen effect that inhibits UVB-induced formation of thymine dimers and sunburn lesions in the epidermis of mice. In addition, caffeine administration has a biological effect that enhances UVB-induced apoptosis thereby enhancing the elimination of damaged precancerous cells, and caffeine administration also enhances apoptosis in tumors. Caffeine administration enhances UVB-induced apoptosis by p53-dependent and p53-independent mechanisms. Exploration of the p53-independent effect indicated that caffeine administration enhanced UVB-induced apoptosis by inhibiting the UVB-induced increase in ATR-mediated formation of phospho-Chk1 (Ser345 and abolishing the UVB-induced decrease in cyclin B1 which resulted in caffeine-induced premature and lethal mitosis in mouse skin. In studies with cultured primary human keratinocytes, inhibition of ATR with siRNA against ATR inhibited Chk1 phosphorylation and enhanced UVB-induced apoptosis. Transgenic mice with decreased epidermal ATR function that were irradiated chronically with UVB had 69% fewer tumors at the end of the study compared with irradiated littermate controls with normal ATR function. These results, which indicate that genetic inhibition of ATR (like pharmacologic inhibition of ATR via caffeine inhibits UVB-induced carcinogenesis and supports the concept that ATR-mediated phosphorylation of Chk1 is an important target for caffeine’s inhibitory effect on UVB-induced carcinogenesis.

  2. Irreversible inhibition of RANK expression as a possible mechanism for IL-3 inhibition of RANKL-induced osteoclastogenesis

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    Khapli, Shruti M.; Tomar, Geetanjali B.; Barhanpurkar, Amruta P.; Gupta, Navita; Yogesha, S.D.; Pote, Satish T. [National Center for Cell Science, University of Pune Campus, Pune 411 007 (India); Wani, Mohan R., E-mail: mohanwani@nccs.res.in [National Center for Cell Science, University of Pune Campus, Pune 411 007 (India)

    2010-09-03

    Research highlights: {yields} IL-3 inhibits receptor activator of NF-{kappa}B ligand (RANKL)-induced osteoclastogenesis. {yields} IL-3 inhibits RANKL-induced JNK activation. {yields} IL-3 down-regulates expression of c-Fos and NFATc1 transcription factors. {yields} IL-3 down-regulates RANK expression posttranscriptionally and irreversibly. {yields} IL-3 inhibits in vivo RANK expression. -- Abstract: IL-3, a cytokine secreted by activated T lymphocytes, stimulates the proliferation, differentiation and survival of pluripotent hematopoietic stem cells. In this study, we investigated the mechanism of inhibitory action of IL-3 on osteoclast differentiation. We show here that IL-3 significantly inhibits receptor activator of NF-{kappa}B (RANK) ligand (RANKL)-induced activation of c-Jun N-terminal kinase (JNK). IL-3 down-regulates expression of c-Fos and nuclear factor of activated T cells (NFATc1) transcription factors. In addition, IL-3 down-regulates RANK expression posttranscriptionally in both purified osteoclast precursors and whole bone marrow cells. Furthermore, the inhibitory effect of IL-3 on RANK expression was irreversible. Interestingly, IL-3 inhibits in vivo RANK expression in mice. Thus, we provide the first evidence that IL-3 irreversibly inhibits RANK expression that results in inhibition of important signaling molecules induced by RANKL.

  3. Irreversible inhibition of RANK expression as a possible mechanism for IL-3 inhibition of RANKL-induced osteoclastogenesis

    International Nuclear Information System (INIS)

    Khapli, Shruti M.; Tomar, Geetanjali B.; Barhanpurkar, Amruta P.; Gupta, Navita; Yogesha, S.D.; Pote, Satish T.; Wani, Mohan R.

    2010-01-01

    Research highlights: → IL-3 inhibits receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis. → IL-3 inhibits RANKL-induced JNK activation. → IL-3 down-regulates expression of c-Fos and NFATc1 transcription factors. → IL-3 down-regulates RANK expression posttranscriptionally and irreversibly. → IL-3 inhibits in vivo RANK expression. -- Abstract: IL-3, a cytokine secreted by activated T lymphocytes, stimulates the proliferation, differentiation and survival of pluripotent hematopoietic stem cells. In this study, we investigated the mechanism of inhibitory action of IL-3 on osteoclast differentiation. We show here that IL-3 significantly inhibits receptor activator of NF-κB (RANK) ligand (RANKL)-induced activation of c-Jun N-terminal kinase (JNK). IL-3 down-regulates expression of c-Fos and nuclear factor of activated T cells (NFATc1) transcription factors. In addition, IL-3 down-regulates RANK expression posttranscriptionally in both purified osteoclast precursors and whole bone marrow cells. Furthermore, the inhibitory effect of IL-3 on RANK expression was irreversible. Interestingly, IL-3 inhibits in vivo RANK expression in mice. Thus, we provide the first evidence that IL-3 irreversibly inhibits RANK expression that results in inhibition of important signaling molecules induced by RANKL.

  4. 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

  5. Molecular mechanisms underlying mancozeb-induced inhibition of TNF-alpha production

    International Nuclear Information System (INIS)

    Corsini, Emanuela; Viviani, Barbara; Birindelli, Sarah; Gilardi, Federica; Torri, Anna; Codeca, Ilaria; Lucchi, Laura; Bartesaghi, Stefano; Galli, Corrado L.; Marinovich, Marina; Colosio, Claudio

    2006-01-01

    Mancozeb, a polymeric complex of manganese ethylenebisdithiocarbamate with zinc salt, is widely used in agriculture as fungicide. Literature data indicate that ethylenebisdithiocarbamates (EBDTCs) may have immunomodulatory effects in humans. We have recently found in agricultural workers occupationally exposed to the fungicide mancozeb a statistically significant decrease in lipopolysaccharide (LPS)-induced tumor necrosis factor-alpha (TNF) production in leukocytes. TNF is an essential proinflammatory cytokine whose production is normally stimulated during an infection. The purpose of this work was to establish an in vitro model reflecting in vivo data and to characterize the molecular mechanism of action of mancozeb. The human promyelocytic cell line THP-1 was used as in vitro model to study the effects of mancozeb and its main metabolite ethylenthiourea (ETU) on LPS-induced TNF release. Mancozeb, but not ETU, at non-cytotoxic concentrations (1-100 μg/ml), induced a dose- and time-dependent inhibition of LPS-induced TNF release, reflecting in vivo data. The modulatory effect observed was not limited to mancozeb but also other EBDTCs, namely zineb and ziram, showed similar inhibitory effects. Mancozeb must be added before or simultaneously to LPS in order to observe the effect, indicating that it acts on early events triggered by LPS. It is known that nuclear factor-κB (NF-κB) tightly regulates TNF transcription. We could demonstrate that mancozeb, modulating LPS-induced reactive oxygen species generation, prevented IκB degradation and NF-κB nuclear translocation, which in turn resulted in decreased TNF production. To further understand the mechanism of the effect of mancozeb on TNF transcription, THP-1 cells were transfected with NF-κB promoter-luciferase construct, and the effect of mancozeb on luciferase activity was measured. Cells transfected with promoter constructs containing κB site showed decreased LPS-induced luciferase activity relative to control

  6. Dicumarol inhibition of NADPH:quinone oxidoreductase induces growth inhibition of pancreatic cancer via a superoxide-mediated mechanism.

    Science.gov (United States)

    Cullen, Joseph J; Hinkhouse, Marilyn M; Grady, Matthew; Gaut, Andrew W; Liu, Jingru; Zhang, Yu Ping; Weydert, Christine J Darby; Domann, Frederick E; Oberley, Larry W

    2003-09-01

    NADPH:quinone oxidoreductase (NQO(1)), a homodimeric, ubiquitous, flavoprotein, catalyzes the two-electron reduction of quinones to hydroquinones. This reaction prevents the one-electron reduction of quinones by cytochrome P450 reductase and other flavoproteins that would result in oxidative cycling with generation of superoxide (O(2)(.-)). NQO(1) gene regulation may be up-regulated in some tumors to accommodate the needs of rapidly metabolizing cells to regenerate NAD(+). We hypothesized that pancreatic cancer cells would exhibit high levels of this enzyme, and inhibiting it would suppress the malignant phenotype. Reverse transcription-PCR, Western blots, and activity assays demonstrated that NQO(1) was up-regulated in the pancreatic cancer cell lines tested but present in very low amounts in the normal human pancreas. To determine whether inhibition of NQO(1) would alter the malignant phenotype, MIA PaCa-2 pancreatic cancer cells were treated with a selective inhibitor of NQO(1), dicumarol. Dicumarol increased intracellular production of O(2)(.-), as measured by hydroethidine staining, and inhibited cell growth. Both of these effects were blunted with infection of an adenoviral vector containing the cDNA for manganese superoxide dismutase. Dicumarol also inhibited cell growth, plating efficiency, and growth in soft agar. We conclude that inhibition of NQO(1) increases intracellular O(2)(.-) production and inhibits the in vitro malignant phenotype of pancreatic cancer. These mechanisms suggest that altering the intracellular redox environment of pancreatic cancer cells may inhibit growth and delineate a potential strategy directed against pancreatic cancer.

  7. Selenium and vitamin E inhibit radiogenic and chemically induced transformation in vitro via different mechanisms

    International Nuclear Information System (INIS)

    Borek, C.; Ong, A.; Mason, H.; Donahue, L.; Biaglow, J.E.

    1986-01-01

    Results from in vivo and in vitro studies showing that antioxidants may act as anticarcinogens support the role of active oxygen in carcinogenesis and provide impetus for exploring the functions of dietary antioxidants in cancer prevention by using in vitro models. The authors examined the single and combined effects of selenium, a component of glutathione peroxidase, and vitamin E, a known antioxidant, on cell transformation induced in C3H/10T-1/2 cells by x-rays, benzo[a]pyrene, or tryptophan pyrolysate and on the levels of cellular scavenging systems peroxide destruction. Incubation of C3H/10T-1/2 cells with 2.5 μM Na 2 SeO 3 (selenium) or with 7 μM α-tocopherol succinate (vitamin E) 24 hr prior to exposure to x-rays or the chemical carcinogens resulted in an inhibition of transformation by each of the antioxidants with an additive-inhibitory action when the two nutrients were combined. Cellular pretreatment with selenium resulted in increased levels of cellular glutathione peroxidase, catalase, and nonprotein thiols (glutathione) and in an enhanced destruction of peroxide. The results support our earlier studies showing that free radical-mediated events play a role in radiation and chemically induced transformation. They indicate that selenium and vitamin E act alone and in additive fashion as radioprotecting and chemopreventing agents. The results further suggest that selenium confers protection in part by inducing or activating cellular free-radical scavenging systems and by enhancing peroxide breakdown while vitamin E appears to confer its protection by and alternate complementary mechanism

  8. Andrographolide Inhibits Mechanical and Thermal Hyperalgesia in a Rat Model of HIV-Induced Neuropathic Pain

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    Zhihua Yi

    2018-06-01

    Full Text Available Aim: In this study, we investigated whether andrographolide (Andro can alleviate neuropathic pain induced by HIV gp120 plus ddC treatment and the mechanism of its action.Methods: The paw withdrawal threshold and the paw withdrawal latency were observed to assess pain behaviors in all groups of the rats, including control group, control combined with Andro treatment group, sham group, gp120 combined with ddC treatment group, gp120 plus ddC combined with A438079 treatment group, and gp120 plus ddC combined with Andro treatment by intrathecally injecting at a dose of 25 μg/20 μl group. The protein expression levels of the P2X7 receptor, tumor necrosis factor-α-receptor (TNFα-R, interleukin-1β (IL-1β, IL-10, phospho-extracellular regulated protein kinases (ERK (p-ERK in the L4–L6 dorsal root ganglia (DRG were measured by western blotting. Real-time quantitative polymerase chain reaction was used to test the mRNA expression level of the P2X7 receptor. Double-labeling immunofluorescence was used to identify the co-localization of the P2X7 receptor with glial fibrillary acidic protein (GFAP in DRG. Molecular docking was performed to identify whether the Andro interacted perfectly with the rat P2X7 (rP2X7 receptor.Results: Andro attenuated the mechanical and thermal hyperalgesia in gp120+ddC-treated rats and down-regulated the P2X7 receptor mRNA and protein expression in the L4–L6 DRGs of gp120+ddC-treated rats. Additionally, Andro simultaneously decreased the expression of TNFα-R and IL-1β protein, increased the expression of IL-10 protein in L4–L6 DRGs, and inhibited the activation of ERK signaling pathways. Moreover, Andro decreased the co-expression of GFAP and the P2X7 receptor in the SGCs of L4–L6 DRG on 14th day after surgery.Conclusion: Andro decreased the hyperalgesia induced by gp120 plus ddC.

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

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    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.

  10. Periostin inhibits mechanical stretch-induced apoptosis in osteoblast-like MG-63 cells.

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    Yu, Kai-Wen; Yao, Chung-Chen; Jeng, Jiiang-Huei; Shieh, Hao-Ying; Chen, Yi-Jane

    2018-04-01

    Appropriate mechanical stress plays an important role in regulating the proliferation and differentiation of osteoblasts, whereas high-level mechanical stress may be harmful and compromise cell survival. Periostin, a matricellular protein, is essential in maintaining functional integrity of bone and collagen-rich connective tissue in response to mechanical stress. This study investigated whether or not high-level mechanical stretch induces cell apoptosis and the regulatory role of periostin in mechanical stretch-induced apoptosis in osteoblastic cells. Osteoblast-like MG-63 cells were seeded onto Bio-Flex I culture plates and subjected to cyclic mechanical stretching (15% elongation, 0.1 Hz) in a Flexercell tension plus system-5000. The same process was applied to cells pre-treated with exogenous human recombinant periostin before mechanical stretching. We used a chromatin condensation and membrane permeability dead cell apoptosis kit to evaluate the stretch-induced cell responses. Expression of caspase-3 and cPARP was examined by immunofluorescent stain and flow cytometry. The expression of periostin in MG-63 cells is involved in the TGF-β signaling pathway. High-level cyclic mechanical stretch induced apoptotic responses in MG-63 osteoblastic cells. The percentages of apoptotic cells and cells expressing cPARP protein increased in the groups of cells subjected to mechanical stretch, but these responses were absent in the presence of exogenous periostin. Our study revealed that high-level mechanical stretch induces apoptotic cell death, and that periostin plays a protective role against mechanical stretch-induced apoptosis in osteoblastic cells. Copyright © 2017. Published by Elsevier B.V.

  11. Fisetin Inhibits Hyperglycemia-Induced Proinflammatory Cytokine Production by Epigenetic Mechanisms

    OpenAIRE

    Hye Joo Kim; Seong Hwan Kim; Jung-Mi Yun

    2012-01-01

    Diabetes is characterized by a proinflammatory state, and several inflammatory processes have been associated with both type 1 and type 2 diabetes and the resulting complications. High glucose levels induce the release of proinflammatory cytokines. Fisetin, a flavonoid dietary ingredient found in the smoke tree (Cotinus coggygria), and is also widely distributed in fruits and vegetables. Fisetin is known to exert anti-inflammatory effects via inhibition of the NF-?B signaling pathway. In this...

  12. LY294002 inhibits glucocorticoid-induced COX-2 gene expression in cardiomyocytes through a phosphatidylinositol 3 kinase-independent mechanism

    International Nuclear Information System (INIS)

    Sun Haipeng; Xu Beibei; Sheveleva, Elena; Chen, Qin M.

    2008-01-01

    Glucocorticoids induce COX-2 expression in rat cardiomyocytes. While investigating whether phosphatidylinositol 3 kinase (PI3K) plays a role in corticosterone (CT)-induced COX-2, we found that LY294002 (LY29) but not wortmannin (WM) attenuates CT from inducing COX-2 gene expression. Expression of a dominant-negative mutant of p85 subunit of PI3K failed to inhibit CT from inducing COX-2 expression. CT did not activate PI3K/AKT signaling pathway whereas LY29 and WM decreased the activity of PI3K. LY303511 (LY30), a structural analogue and a negative control for PI3K inhibitory activity of LY29, also suppressed COX-2 induction. These data suggest PI3K-independent mechanisms in regulating CT-induced COX-2 expression. LY29 and LY30 do not inhibit glucocorticoid receptor transactivity. Both compounds have been reported to inhibit Casein Kinase 2 activity and modulate potassium and calcium levels independent of PI3K, while LY29 has been reported to inhibit mammalian Target of Rapamycin (mTOR), and DNA-dependent Protein Kinase (DNA-PK). Inhibitor of Casein Kinase 2 (CK2), mTOR or DNA-PK failed to prevent CT from inducing COX-2 expression. Tetraethylammonium (TEA), a potassium channel blocker, and nimodipine, a calcium channel blocker, both attenuated CT from inducing COX-2 gene expression. CT was found to increase intracellular Ca 2+ concentration, which can be inhibited by LY29, TEA or nimodipine. These data suggest a possible role of calcium instead of PI3K in CT-induced COX-2 expression in cardiomyocytes

  13. Mechanism of vasoconstriction induced by chronic inhibition of nitric oxide in rats.

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    Bank, N; Aynedjian, H S; Khan, G A

    1994-09-01

    Either acute or chronic inhibition of nitric oxide synthesis by L-arginine analogues results in increases in mean arterial pressure and reductions in renal blood flow. The role of endogenous vasoconstrictors in mediating these effects is not entirely clear. In the present study, nitric oxide was inhibited in male Sprague-Dawley rats by oral administration of nitro-L-arginine for 3 weeks. At the end of this time, mean arterial pressure was 30 to 40 mm Hg higher than in normal controls, renal blood flow and glomerular filtration rate were 25% to 30% lower, and renal vascular resistance was markedly increased. Intravenous infusion of receptor antagonists for angiotensin II, thromboxane, epinephrine, and endothelin-1 had no significant effect on the hypertension. Inhibition of prostaglandin synthesis and furosemide-induced diuresis in the presence of angiotensin blockade also had no effect on blood pressure. Renal vascular resistance was also unaffected by these interventions, except that saralasin did reduce renal resistance in both control and nitric oxide-inhibited groups. However, the absolute level of renal vascular resistance remained higher in the latter group. Calcium channel blockade partially corrected blood pressure and renal resistance, but the levels remained significantly higher than in control animals. The findings are consistent with the view that the increase in vascular smooth muscle tone caused by inhibition of nitric oxide synthesis cannot be accounted for by overexpression of common endogenous vasoconstrictors. Rather, the generalized increase in vascular smooth muscle tone appears to be due to a direct effect of reduced nitric oxide availability, which may lead to an increase in intracellular calcium concentration or sensitivity.

  14. Fisetin Inhibits Hyperglycemia-Induced Proinflammatory Cytokine Production by Epigenetic Mechanisms

    Directory of Open Access Journals (Sweden)

    Hye Joo Kim

    2012-01-01

    Full Text Available Diabetes is characterized by a proinflammatory state, and several inflammatory processes have been associated with both type 1 and type 2 diabetes and the resulting complications. High glucose levels induce the release of proinflammatory cytokines. Fisetin, a flavonoid dietary ingredient found in the smoke tree (Cotinus coggygria, and is also widely distributed in fruits and vegetables. Fisetin is known to exert anti-inflammatory effects via inhibition of the NF-κB signaling pathway. In this study, we analyzed the effects of fisetin on proinflammatory cytokine secretion and epigenetic regulation, in human monocytes cultured under hyperglycemic conditions. Human monocytic (THP-1 cells were cultured under control (14.5 mmol/L mannitol, normoglycemic (NG, 5.5 mmol/L glucose, or hyperglycemic (HG, 20 mmol/L glucose conditions, in the absence or presence of fisetin. Fisetin was added (3–10 μM for 48 h. While the HG condition significantly induced histone acetylation, NF-κB activation, and proinflammatory cytokine (IL-6 and TNF-α release from THP-1 cells, fisetin suppressed NF-κB activity and cytokine release. Fisetin treatment also significantly reduced CBP/p300 gene expression, as well as the levels of acetylation and HAT activity of the CBP/p300 protein, which is a known NF-κB coactivator. These results suggest that fisetin inhibits HG-induced cytokine production in monocytes, through epigenetic changes involving NF-κB. We therefore propose that fisetin supplementation be considered for diabetes prevention.

  15. Proton pump inhibitor-induced tumour cell death by inhibition of a detoxification mechanism.

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    Fais, S

    2010-05-01

    This review presents a possible new approach against cancer, as represented by inhibition of proton pumps, a mechanism used by tumour cells to avoid intracellular accumulation of toxic substances. Proton pump inhibitors (PPIs) belong to a family of pro-drugs that are currently used in the treatment of peptic diseases needing acidity to be activated. PPIs target the acidic tumour mass, where they are metabolized, thus blocking proton traffic. Proton pump inhibition triggers a rapid cell death as a result of intracellular acidification, caspase activation and early accumulation of reactive oxygen species into tumour cells. As a whole, the devastating effect of PPIs on tumour cells suggest the triggering of a fatal cell toxification. Many human tumours, including melanoma, osteosarcoma, lymphomas and various adenocarcinomas are responsive to PPIs. This appears highly conceivable, in as much as almost all human tumours are acidic and express high levels of proton pumps. Paradoxically, metastatic tumours appear to be more responsive to PPIs being more acidic than the majority of primary tumours. However, two clinical trials test the effectiveness of PPIs in chemosensitizing melanoma and osteosarcoma patients. Indeed, tumour acidity represents a very potent mechanism of chemoresistance. A majority of cytotoxic agents, being weak bases, are quickly protonated outside and do not enter the cells, thus preventing drugs to reach specific cellular targets. Clinical data will provide the proof of concept on the use of PPIs as a new class of antitumour agent with a very low level of systemic toxicity as compared with standard chemotherapeutic agents.

  16. Inhibition Mechanism of Uranyl Reduction Induced by Calcium-Carbonato Complexes

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    Jones, M. E.; Bargar, J.; Fendorf, S. E.

    2015-12-01

    Uranium mobility in the subsurface is controlled by the redox state and chemical speciation, generally as minimally soluble U(IV) or soluble U(VI) species. In the presence of even low carbonate concentrations the uranyl-carbonato complex quickly becomes the dominant aqueous species; they are, in fact, the primary aqueous species in most groundwaters. Calcium in groundwater leads to ternary calcium-uranyl-carbonato complexes that limit the rate and extent of U(VI) reduction. This decrease in reduction rate has been attributed to surface processes, thermodynamic limitations, and kinetic factors. Here we present a new mechanism for the inhibition of ferrous iron reduction of uranyl-carbonato species in the presence of calcium. A series of experiments under variable Ca conditions were preformed to determine the role of Ca in the inhibition of U reduction by ferrous iron. Calcium ions in the Ca2UO2(CO3)3 complex sterically prevent the interaction of Fe(II) with U(VI), in turn preventing the Fe(II)-U(VI) distance required for electron transfer. The mechanism described here helps to predict U redox transformations in suboxic environments and clarifies the role of Ca in the fate and mobility of U. Electrochemical measurements further show the decrease of the U(VI) to U(V) redox potential of the uranyl-carbonato complex with decreasing pH suggesting the first electron transfer is critical determining the rate and extent of uranium reduction.

  17. Quercetin Inhibits Peripheral and Spinal Cord Nociceptive Mechanisms to Reduce Intense Acute Swimming-Induced Muscle Pain in Mice

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    Borghi, Sergio M.; Pinho-Ribeiro, Felipe A.; Fattori, Victor; Bussmann, Allan J. C.; Vignoli, Josiane A.; Camilios-Neto, Doumit; Casagrande, Rubia; Verri, Waldiceu A.

    2016-01-01

    The present study aimed to evaluate the effects of the flavonoid quercetin (3,3´,4´,5,7-pentahydroxyflavone) in a mice model of intense acute swimming-induced muscle pain, which resembles delayed onset muscle soreness. Quercetin intraperitoneal (i.p.) treatment dose-dependently reduced muscle mechanical hyperalgesia. Quercetin inhibited myeloperoxidase (MPO) and N-acetyl-β-D- glucosaminidase (NAG) activities, cytokine production, oxidative stress, cyclooxygenase-2 (COX-2) and gp91phox mRNA expression and muscle injury (creatinine kinase [CK] blood levels and myoblast determination protein [MyoD] mRNA expression) as well as inhibited NFκB activation and induced Nrf2 and HO-1 mRNA expression in the soleus muscle. Beyond inhibiting those peripheral effects, quercetin also inhibited spinal cord cytokine production, oxidative stress and glial cells activation (glial fibrillary acidic protein [GFAP] and ionized calcium-binding adapter molecule 1 [Iba-1] mRNA expression). Concluding, the present data demonstrate that quercetin is a potential molecule for the treatment of muscle pain conditions related to unaccustomed exercise. PMID:27583449

  18. Cisplatin-induced apoptosis inhibits autophagy, which acts as a pro-survival mechanism in human melanoma cells.

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    Del Bello, Barbara; Toscano, Marzia; Moretti, Daniele; Maellaro, Emilia

    2013-01-01

    The interplay between a non-lethal autophagic response and apoptotic cell death is still a matter of debate in cancer cell biology. In the present study performed on human melanoma cells, we investigate the role of basal or stimulated autophagy in cisplatin-induced cytotoxicity, as well as the contribution of cisplatin-induced activation of caspases 3/7 and conventional calpains. The results show that, while down-regulating Beclin-1, Atg14 and LC3-II, cisplatin treatment inhibits the basal autophagic response, impairing a physiological pro-survival response. Consistently, exogenously stimulated autophagy, obtained with trehalose or calpains inhibitors (MDL-28170 and calpeptin), protects from cisplatin-induced apoptosis, and such a protection is reverted by inhibiting autophagy with 3-methyladenine or ATG5 silencing. In addition, during trehalose-stimulated autophagy, the cisplatin-induced activation of calpains is abrogated, suggesting the existence of a feedback loop between the autophagic process and calpains. On the whole, our results demonstrate that in human melanoma cells autophagy may function as a beneficial stress response, hindered by cisplatin-induced death mechanisms. In a therapeutic perspective, these findings suggest that the efficacy of cisplatin-based polychemotherapies for melanoma could be potentiated by inhibitors of autophagy.

  19. Hydroxychloroquine preferentially induces apoptosis of CD45RO+ effector T cells by inhibiting autophagy: A possible mechanism for therapeutic modulation of T cells

    OpenAIRE

    van Loosdregt, Jorg; Spreafico, Roberto; Rossetti, Maura; Prakken, Berent J; Lotz, Martin; Albani, Salvatore

    2013-01-01

    Although hydroxychloroquine is used for treatment of numerous autoimmune disorders the mechanism is unclear. We here demonstrate that hydroxychloroquine preferentially induces apoptosis of CD45RO+ memory and effector T cells by inhibiting the survival pathway of autophagy.

  20. Leptin Inhibits the Proliferation of Vascular Smooth Muscle Cells Induced by Angiotensin II through Nitric Oxide-Dependent Mechanisms

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    Amaia Rodríguez

    2010-01-01

    Full Text Available Objective. This study was designed to investigate whether leptin modifies angiotensin (Ang II-induced proliferation of aortic vascular smooth muscle cells (VSMCs from 10-week-old male Wistar and spontaneously hypertensive rats (SHR, and the possible role of nitric oxide (NO. Methods. NO and NO synthase (NOS activity were assessed by the Griess and 3H-arginine/citrulline conversion assays, respectively. Inducible NOS (iNOS and NADPH oxidase subutnit Nox2 expression was determined by Western-blot. The proliferative responses to Ang II were evaluated through enzymatic methods. Results. Leptin inhibited the Ang II-induced proliferative response of VSMCs from control rats. This inhibitory effect of leptin was abolished by NOS inhibitor, NMMA, and iNOS selective inhibitor, L-NIL, and was not observed in leptin receptor-deficient fa/fa rats. SHR showed increased serum leptin concentrations and lipid peroxidation. Despite a similar leptin-induced iNOS up-regulation, VSMCs from SHR showed an impaired NOS activity and NO production induced by leptin, and an increased basal Nox2 expression. The inhibitory effect of leptin on Ang II-induced VSMC proliferation was attenuated. Conclusion. Leptin blocks the proliferative response to Ang II through NO-dependent mechanisms. The attenuation of this inhibitory effect of leptin in spontaneous hypertension appears to be due to a reduced NO bioavailability in VSMCs.

  1. Inhibition of PDGFR by CP-673451 induces apoptosis and increases cisplatin cytotoxicity in NSCLC cells via inhibiting the Nrf2-mediated defense mechanism.

    Science.gov (United States)

    Yang, Yang; Deng, Yanchao; Chen, Xiangcui; Zhang, Jiahao; Chen, Yueming; Li, Huachao; Wu, Qipeng; Yang, Zhicheng; Zhang, Luyong; Liu, Bing

    2018-05-29

    Platelet-derived growth factor receptors (PDGFRs) are abundantly expressed by stromal cells in the non-small cell lung cancer (NSCLC) microenvironment, and in a subset of cancer cells, usually with their overexpression and/or activating mutation. However, the effect of PDGFR inhibition on lung cancer cells themselves has been largely neglected. In this study, we investigated the anticancer activity of CP-673451, a potent and selective inhibitor of PDGFRβ, on NSCLC cell lines (A549 and H358) and the potential mechanism. The results showed that inhibition of PDGFRβ by CP-673451 induced a significant increase in cell apoptosis, accompanied by ROS accumulation. However, CP-673451 exerted less cytotoxicity in normal lung epithelial cell line BEAS-2B cells determined by MTT and apoptosis assay. Elimination of ROS by NAC reversed the CP-673451-induced apoptosis in NSCLC cells. Furthermore, CP-673451 down-regulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) probably through inhibition of PI3K/Akt pathway. Rescue of Nrf2 activity counteracted the effects of CP-673451 on cell apoptosis and ROS accumulation. Silencing PDGFRβ expression by PDGFRβ siRNA exerted similar effects with CP-673451 in A549 cells, and when PDGFRβ was knockdowned by PDGFRβ siRNA, CP-673451 produced no additional effects on cell viability, ROS and GSH production, Nrf2 expression as well as PI3K/Akt pathway activity. Specifically, Nrf2 plays an indispensable role in NSCLC cell sensitivity to platinum-based treatments and we found that combination of CP-673451 and cisplatin produced a synergistic anticancer effect and substantial ROS production in vitro. Therefore, these results clearly demonstrate the effectiveness of inhibition of PDGFRβ against NSCLC cells and strongly suggest that CP-673451 may be a promising adjuvant chemotherapeutic drug. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Celecoxib Induced Tumor Cell Radiosensitization by Inhibiting Radiation Induced Nuclear EGFR Transport and DNA-Repair: A COX-2 Independent Mechanism

    International Nuclear Information System (INIS)

    Dittmann, Klaus H.; Mayer, Claus; Ohneseit, Petra A.; Raju, Uma; Andratschke, Nickolaus H.; Milas, Luka; Rodemann, H. Peter

    2008-01-01

    Purpose: The purpose of the study was to elucidate the molecular mechanisms mediating radiosensitization of human tumor cells by the selective cyclooxygenase (COX)-2 inhibitor celecoxib. Methods and Materials: Experiments were performed using bronchial carcinoma cells A549, transformed fibroblasts HH4dd, the FaDu head-and-neck tumor cells, the colon carcinoma cells HCT116, and normal fibroblasts HSF7. Effects of celecoxib treatment were assessed by clonogenic cell survival, Western analysis, and quantification of residual DNA damage by γH 2 AX foci assay. Results: Celecoxib treatment resulted in a pronounced radiosensitization of A549, HCT116, and HSF7 cells, whereas FaDu and HH4dd cells were not radiosensitized. The observed radiosensitization could neither be correlated with basal COX-2 expression pattern nor with basal production of prostaglandin E2, but was depended on the ability of celecoxib to inhibit basal and radiation-induced nuclear transport of epidermal growth factor receptor (EGFR). The nuclear EGFR transport was strongly inhibited in A549-, HSF7-, and COX-2-deficient HCT116 cells, which were radiosensitized, but not in FaDu and HH4dd cells, which resisted celecoxib-induced radiosensitization. Celecoxib inhibited radiation-induced DNA-PK activation in A549, HSF7, and HCT116 cells, but not in FaDu and HH4dd cells. Consequentially, celecoxib increased residual γH2AX foci after irradiation, demonstrating that inhibition of DNA repair has occurred in responsive A549, HCT116, and HSF7 cells only. Conclusions: Celecoxib enhanced radiosensitivity by inhibition of EGFR-mediated mechanisms of radioresistance, a signaling that was independent of COX-2 activity. This novel observation may have therapeutic implications such that COX-2 inhibitors may improve therapeutic efficacy of radiation even in patients whose tumor radioresistance is not dependent on COX-2

  3. Inhibition of insulin-dependent glucose uptake by trivalent arsenicals: possible mechanism of arsenic-induced diabetes

    International Nuclear Information System (INIS)

    Walton, Felecia S.; Harmon, Anne W.; Paul, David S.; Drobna, Zuzana; Patel, Yashomati M.; Styblo, Miroslav

    2004-01-01

    Chronic exposures to inorganic arsenic (iAs) have been associated with increased incidence of noninsulin (type-2)-dependent diabetes mellitus. Although mechanisms by which iAs induces diabetes have not been identified, the clinical symptoms of the disease indicate that iAs or its metabolites interfere with insulin-stimulated signal transduction pathway or with critical steps in glucose metabolism. We have examined effects of iAs and methylated arsenicals that contain trivalent or pentavalent arsenic on glucose uptake by 3T3-L1 adipocytes. Treatment with inorganic and methylated pentavalent arsenicals (up to 1 mM) had little or no effect on either basal or insulin-stimulated glucose uptake. In contrast, trivalent arsenicals, arsenite (iAs III ), methylarsine oxide (MAs III O), and iododimethylarsine (DMAs III O) inhibited insulin-stimulated glucose uptake in a concentration-dependent manner. Subtoxic concentrations of iAs III (20 μM), MAs III O (1 μM), or DMAs III I (2 μM) decreased insulin-stimulated glucose uptake by 35-45%. Basal glucose uptake was significantly inhibited only by cytotoxic concentrations of iAs III or MAs III O. Examination of the components of the insulin-stimulated signal transduction pathway showed that all trivalent arsenicals suppressed expression and possibly phosphorylation of protein kinase B (PKB/Akt). The concentration of an insulin-responsive glucose transporter (GLUT4) was significantly lower in the membrane region of 3T3-L1 adipocytes treated with trivalent arsenicals as compared with untreated cells. These results suggest that trivalent arsenicals inhibit insulin-stimulated glucose uptake by interfering with the PKB/Akt-dependent mobilization of GLUT4 transporters in adipocytes. This mechanism may be, in part, responsible for the development of type-2 diabetes in individuals chronically exposed to iAs

  4. Mitochondrial ADP/ATP exchange inhibition: a novel off-target mechanism underlying ibipinabant-induced myotoxicity.

    Science.gov (United States)

    Schirris, Tom J J; Ritschel, Tina; Herma Renkema, G; Willems, Peter H G M; Smeitink, Jan A M; Russel, Frans G M

    2015-09-29

    Cannabinoid receptor 1 (CB1R) antagonists appear to be promising drugs for the treatment of obesity, however, serious side effects have hampered their clinical application. Rimonabant, the first in class CB1R antagonist, was withdrawn from the market because of psychiatric side effects. This has led to the search for more peripherally restricted CB1R antagonists, one of which is ibipinabant. However, this 3,4-diarylpyrazoline derivative showed muscle toxicity in a pre-clinical dog study with mitochondrial dysfunction. Here, we studied the molecular mechanism by which ibipinabant induces mitochondrial toxicity. We observed a strong cytotoxic potency of ibipinabant in C2C12 myoblasts. Functional characterization of mitochondria revealed increased cellular reactive oxygen species generation and a decreased ATP production capacity, without effects on the catalytic activities of mitochondrial enzyme complexes I-V or the complex specific-driven oxygen consumption. Using in silico off-target prediction modelling, combined with in vitro validation in isolated mitochondria and mitoplasts, we identified adenine nucleotide translocase (ANT)-dependent mitochondrial ADP/ATP exchange as a novel molecular mechanism underlying ibipinabant-induced toxicity. Minor structural modification of ibipinabant could abolish ANT inhibition leading to a decreased cytotoxic potency, as observed with the ibipinabant derivative CB23. Our results will be instrumental in the development of new types of safer CB1R antagonists.

  5. An epigenetic signal encoded protection mechanism is activated by graphene oxide to inhibit its induced reproductive toxicity in Caenorhabditis elegans.

    Science.gov (United States)

    Zhao, Yunli; Wu, Qiuli; Wang, Dayong

    2016-02-01

    Although many studies have suggested the adverse effects of engineered nanomaterials (ENMs), the self-protection mechanisms for organisms against ENMs toxicity are still largely unclear. Using Caenorhabditis elegans as an in vivo assay system, our results suggest the toxicity of graphene oxide in reducing reproductive capacity by inducing damage on gonad development. The observed reproductive toxicity of GO on gonad development was due to the combinational effect of germline apoptosis and cell cycle arrest, and DNA damage activation might act as an inducer for this combinational effect. For the underlying molecular mechanism of reproductive toxicity of GO, we raised a signaling cascade of HUS-1/CLK-2-CEP-1-EGL-1-CED-4-CED-3 to explain the roles of core apoptosis signaling pathway and DNA damage checkpoints. Moreover, we identified a miRNA regulation mechanism activated by GO to suppress its induced reproductive toxicity. A mir-360 regulation mechanism was activated by GO to suppress its induced DNA damage-apoptosis signaling cascade through affecting component of CEP-1. Our identified epigenetic signal encoded protection mechanism activated by GO suggests a novel self-protection mechanism for organisms against the ENMs toxicity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Low Frequency Electroacupuncture Alleviated Spinal Nerve Ligation Induced Mechanical Allodynia by Inhibiting TRPV1 Upregulation in Ipsilateral Undamaged Dorsal Root Ganglia in Rats

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    Yong-Liang Jiang

    2013-01-01

    Full Text Available Neuropathic pain is an intractable problem in clinical practice. Accumulating evidence shows that electroacupuncture (EA with low frequency can effectively relieve neuropathic pain. Transient receptor potential vanilloid type 1 (TRPV1 plays a key role in neuropathic pain. The study aimed to investigate whether neuropathic pain relieved by EA administration correlates with TRPV1 inhibition. Neuropathic pain was induced by right L5 spinal nerve ligation (SNL in rats. 2 Hz EA stimulation was administered. SNL induced mechanical allodynia in ipsilateral hind paw. SNL caused a significant reduction of TRPV1 expression in ipsilateral L5 dorsal root ganglia (DRG, but a significant up-regulation in ipsilateral L4 and L6 DRGs. Calcitonin gene-related peptide (CGRP change was consistent with that of TRPV1. EA alleviated mechanical allodynia, and inhibited TRPV1 and CGRP overexpressions in ipsilateral L4 and L6 DRGs. SNL did not decrease pain threshold of contralateral hind paw, and TRPV1 expression was not changed in contralateral L5 DRG. 0.001, 0.01 mg/kg TRPV1 agonist 6′-IRTX fully blocked EA analgesia in ipsilateral hind paw. 0.01 mg/kg 6′-IRTX also significantly decreased pain threshold of contralateral paw. These results indicated that inhibition of TRPV1 up-regulation in ipsilateral adjacent undamaged DRGs contributed to low frequency EA analgesia for mechanical allodynia induced by spinal nerve ligation.

  7. Nfkb1 inhibits LPS-induced IFN-β and IL-12 p40 production in macrophages by distinct mechanisms.

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    Xixing Zhao

    Full Text Available Nfkb1-deficient murine macrophages express higher levels of IFN-β and IL-12 p40 following LPS stimulation than control macrophages, but the molecular basis for this phenomenon has not been completely defined. Nfkb1 encodes several gene products including the NF-κB subunit p50 and its precursor p105. p50 is derived from the N-terminal of 105, and p50 homodimers can exhibit suppressive activity when overexpressed. The C-terminal region of p105 is necessary for LPS-induced ERK activation and it has been suggested that ERK activity inhibits both IFN-β and IL-12 p40 following LPS stimulation. However, the contributions of p50 and the C-terminal domain of p105 in regulating endogenous IFN-β(Ifnb and IL-12 p40 (Il12b gene expression in macrophages following LPS stimulation have not been directly compared.We have used recombinant retroviruses to express p105, p50, and the C-terminal domain of p105 (p105ΔN in Nfkb1-deficient murine bone marrow-derived macrophages at near endogenous levels. We found that both p50 and p105ΔN inhibited expression of Ifnb, and that inhibition of Ifnb by p105ΔN depended on ERK activation, because a mutant of p105ΔN (p105ΔNS930A that lacks a key serine necessary to support ERK activation failed to inhibit. In contrast, only p105ΔN but not p50 inhibited Il12b expression. Surprisingly, p105ΔNS930A retained inhibitory activity for Il12b, indicating that ERK activation was not necessary for inhibition. The differential effects of p105ΔNS930A on Ifnb and Il12b expression inversely correlated with the function of one of its binding partners, c-Rel. This raised the possibility that p105ΔNS930A influences gene expression by interfering with the function of c-Rel.These results demonstrate that Nfkb1 exhibits multiple gene-specific inhibitory functions following TLR stimulation of murine macrophages.

  8. Tetrandrine, an Activator of Autophagy, Induces Autophagic Cell Death via PKC-α Inhibition and mTOR-Dependent Mechanisms

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    Vincent Kam Wai Wong

    2017-06-01

    Full Text Available Emerging evidence suggests the therapeutic role of autophagic modulators in cancer therapy. This study aims to identify novel traditional Chinese medicinal herbs as potential anti-tumor agents through autophagic induction, which finally lead to autophagy mediated-cell death in apoptosis-resistant cancer cells. Using bioactivity-guided purification, we identified tetrandrine (Tet from herbal plant, Radix stephaniae tetrandrae, as an inducer of autophagy. Across a number of cancer cell lines, we found that breast cancer cells treated with tetrandrine show an increase autophagic flux and formation of autophagosomes. In addition, tetrandrine induces cell death in a panel of apoptosis-resistant cell lines that are deficient for caspase 3, caspase 7, caspase 3 and 7, or Bax-Bak respectively. We also showed that tetrandrine-induced cell death is independent of necrotic cell death. Mechanistically, tetrandrine induces autophagy that depends on mTOR inactivation. Furthermore, tetrandrine induces autophagy in a calcium/calmodulin-dependent protein kinase kinase-β (CaMKK-β, 5′ AMP-activated protein kinase (AMPK independent manner. Finally, by kinase profiling against 300 WT kinases and computational molecular docking analysis, we showed that tetrandrine is a novel PKC-α inhibitor, which lead to autophagic induction through PKC-α inactivation. This study provides detailed insights into the novel cytotoxic mechanism of an anti-tumor compound originated from the herbal plant, which may be useful in promoting autophagy mediated- cell death in cancer cell that is resistant to apoptosis.

  9. Direct Renin Inhibition with Aliskiren Improves Ischemia-Induced Neovasculogenesis in Diabetic Animals via the SDF-1 Related Mechanism.

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    Ting-Ting Chang

    Full Text Available Aliskiren is a direct renin inhibitor which is suggested to modify proangiogenic cells in addition to lower blood pressure. Given that angiogenesis is impaired in the presence of diabetes mellitus, we would like to investigate whether and how aliskiren enhances endothelial progenitor cells (EPCs and improves ischemic-induced neovasculogenesis by an effect independent of blood pressure reduction in diabetic animals.Streptozotocin-induced diabetic mice were administered with either aliskiren (5 or 25 mg/kg/day using an osmotic pump or hydralazine (2 or 10 mg/kg/day given in drinking water for two weeks prior to a hind-limb ischemia surgery. Laser Doppler imaging and flow cytometry were used to evaluate the degree of neovasculogenesis and the circulating levels of EPCs, respectively.In streptozotocin-induced diabetic mice, aliskiren enhanced the recovery of limb perfusion and capillary density, increased the number of circulating Sca-1+/Flk-1+ EPC-like cells, and elevated the levels of the plasma vascular endothelial growth factor (VEGF and stromal cell-derived factor (SDF-1α in a dose-dependent manner, whereas there were no such effects in hydralazine-treated mice. Intraperitoneal administration of anti-SDF-1 neutralizing monoclonal antibodies abolished the effects of aliskiren.Independent of the reduction of blood pressure, aliskiren enhanced ischemia-induced neovasculogenesis in a dose-dependent manner via VEGF/SDF-1α related mechanisms in diabetic mice.

  10. Inhibition of T-Type Voltage Sensitive Calcium Channel Reduces Load-Induced OA in Mice and Suppresses the Catabolic Effect of Bone Mechanical Stress on Chondrocytes.

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    Padma P Srinivasan

    Full Text Available Voltage-sensitive calcium channels (VSCC regulate cellular calcium influx, one of the earliest responses to mechanical stimulation in osteoblasts. Here, we postulate that T-type VSCCs play an essential role in bone mechanical response to load and participate in events leading to the pathology of load-induced OA. Repetitive mechanical insult was used to induce OA in Cav3.2 T-VSCC null and wild-type control mouse knees. Osteoblasts (MC3T3-E1 and chondrocytes were treated with a selective T-VSCC inhibitor and subjected to fluid shear stress to determine how blocking of T-VSCCs alters the expression profile of each cell type upon mechanical stimulation. Conditioned-media (CM obtained from static and sheared MC3T3-E1 was used to assess the effect of osteoblast-derived factors on the chondrocyte phenotype. T-VSCC null knees exhibited significantly lower focal articular cartilage damage than age-matched controls. In vitro inhibition of T-VSCC significantly reduced the expression of both early and late mechanoresponsive genes in osteoblasts but had no effect on gene expression in chondrocytes. Furthermore, treatment of chondrocytes with CM obtained from sheared osteoblasts induced expression of markers of hypertrophy in chondrocytes and this was nearly abolished when osteoblasts were pre-treated with the T-VSCC-specific inhibitor. These results indicate that T-VSCC plays a role in signaling events associated with induction of OA and is essential to the release of osteoblast-derived factors that promote an early OA phenotype in chondrocytes. Further, these findings suggest that local inhibition of T-VSCC may serve as a therapy for blocking load-induced bone formation that results in cartilage degeneration.

  11. The mechanism of kaempferol induced apoptosis and inhibited proliferation in human cervical cancer SiHa cell: From macro to nano.

    Science.gov (United States)

    Tu, Lv-Ying; Bai, Hai-Hua; Cai, Ji-Ye; Deng, Sui-Ping

    2016-11-01

    Kaempferol has been identified as a potential cancer therapeutic agent by an increasing amount of evidences. However, the changes in the topography of cell membrane induced by kaempferol at subcellular- or nanometer-level were still unclear. In this work, the topographical changes of cytomembrane in human cervical cancer cell (SiHa) induced by kaempferol, as well as the role of kaempferol in apoptosis induction and its possible mechanisms, were investigated. At the macro level, MTT assays showed that kaempferol inhibited the proliferation of SiHa cells in a time- and dose-dependent manner. Flow cytometry analysis demonstrated that kaempferol could induce SiHa cell apoptosis, mitochondrial membrane potential disruption, and intracellular free calcium elevation. At the micro level, fluorescence imaging by laser scanning confocal microscopy (LSCM) indicated that kaempferol could also destroy the networks of microtubules. Using high resolution atomic force microscopy (AFM), we determined the precise changes of cellular membrane induced by kaempferol at subcellular or nanometer level. The spindle-shaped SiHa cells shrank after kaempferol treatment, with significantly increased cell surface roughness. These data showed structural characterizations of cellular topography in kaempferol-induced SiHa cell apoptosis and might provide novel integrated information from macro to nano level to assess the impact of kaempferol on cancer cells, which might be important for the understanding of the anti-cancer mechanisms of drugs. SCANNING 38:644-653, 2016. © 2016 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

  12. The Methanolic Extract from Murraya koenigii L. Inhibits Glutamate-Induced Pain and Involves ATP-Sensitive K+ Channel as Antinociceptive Mechanism

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    Nushrat Sharmin Ani

    2016-01-01

    Full Text Available Murraya koenigii L. is a perennial shrub, belonging to the family Rutaceae. Traditionally, the leaves of this plant are extensively used in treatment of a wide range of diseases and disorders including pain and inflammation. Although researchers have revealed the antinociceptive effects of this plant’s leaves during past few years, the mechanisms underlying these effects are still unknown. Therefore, the present study evaluated some antinociceptive mechanisms of the methanolic extract of M. koenigii (MEMK leaves along with its antinociceptive potential using several animal models. The antinociceptive effects of MEMK were evaluated using formalin-induced licking and acetic acid-induced writhing tests at the doses of 50, 100, and 200 mg/kg. In addition, we also justified the possible participations of glutamatergic system and ATP-sensitive potassium channels in the observed activities. Our results demonstrated that MEMK significantly (p<0.01 inhibited the pain thresholds induced by formalin and acetic acid in a dose-dependent manner. MEMK also significantly (p<0.01 suppressed glutamate-induced pain. Moreover, pretreatment with glibenclamide (an ATP-sensitive potassium channel blocker at 10 mg/kg significantly (p<0.05 reversed the MEMK-mediated antinociception. These revealed that MEMK might have the potential to interact with glutamatergic system and the ATP-sensitive potassium channels to exhibit its antinociceptive activities. Therefore, our results strongly support the antinociceptive effects of M. koenigii leaves and provide scientific basis of their analgesic uses in the traditional medicine.

  13. Statin-induced inhibition of breast cancer proliferation and invasion involves attenuation of iron transport: intermediacy of nitric oxide and antioxidant defence mechanisms.

    Science.gov (United States)

    Kanugula, Anantha Koteswararao; Gollavilli, Paradesi Naidu; Vasamsetti, Sathish Babu; Karnewar, Santosh; Gopoju, Raja; Ummanni, Ramesh; Kotamraju, Srigiridhar

    2014-08-01

    Accumulating evidence from in vitro, in vivo, clinical and epidemiological studies shows promising results for the use of statins against many cancers including breast carcinoma. However, the molecular mechanisms responsible for the anti-proliferative and anti-invasive properties of statins still remain elusive. In this study, we investigated the involvement of nitric oxide, iron homeostasis and antioxidant defence mechanisms in mediating the anti-proliferative and anti-invasive properties of hydrophobic statins in MDA-MB-231, MDA-MB-453 and BT-549 metastatic triple negative breast cancer cells. Fluvastatin and simvastatin significantly increased cytotoxicity which was reversed with mevalonate. Interestingly, fluvastatin downregulated transferrin receptor (TfR1), with a concomitant depletion of intracellular iron levels in these cells. Statin-induced effects were mimicked by geranylgeranyl transferase inhibitor (GGTI-298) but not farnesyl transferase inhibitor (FTI-277). Further, it was observed that TfR1 downregulation is mediated by increased nitric oxide levels via inducible nitric oxide synthase (iNOS) expression. NOS inhibitors (asymmetric dimethylarginine and 1400W) counteracted and sepiapterin, a precursor of tetrahydrobiopterin, exacerbated statin-induced depletion of intracellular iron levels. Notably, fluvastatin increased manganese superoxide dismutase (by repressing the transcription factor DNA damage-binding protein 2), catalase and glutathione which, in turn, diminished H2 O2 levels. Fluvastatin-induced downregulation of TfR1, matrix metalloproteinase-2, -9 and inhibition of invasion were reversed in the presence of aminotriazole, a specific inhibitor of catalase. Finally, we conclude that fluvastatin, by altering iron homeostasis, nitric oxide generation and antioxidant defence mechanisms, induces triple negative breast cancer cell death. © 2014 FEBS.

  14. Inhibition of deprivation-induced food intake by GABA(A) antagonists: roles of the hypothalamic, endocrine and alimentary mechanisms.

    Science.gov (United States)

    Kamatchi, Ganesan L; Rathanaswami, Palaniswami

    2012-07-01

    The role of gamma amino butyric acid A receptors/neurons of the hypothalamic, endocrine and alimentary systems in the food intake seen in hunger was studied in 20 h food-deprived rats. Food deprivation decreased blood glucose, serum insulin and produced hyperphagia. The hyperphagia was inhibited by subcutaneous or ventromedial hypothalamic administration of gamma amino butyric acid A antagonists picrotoxin or bicuculline. Although results of blood glucose was variable, insulin level was increased by picrotoxin or bicuculline. In contrast, lateral hypothalamic administration of these agents failed to reproduce the above changes. Subcutaneous administration of picrotoxin or bicuculline increased gastric content, decreased gastric motility and small bowel transit. In contrast, ventromedial or lateral hypothalamic administration of picrotoxin or bicuculline failed to alter the gastric content but decreased the small bowel transit. The results of alimentary studies suggest that gamma amino butyric acid neurons of both ventromedial and lateral hypothalamus selectively regulate small bowel transit but not the gastric content. It may be concluded that ventromedial hypothalamus plays a dominant role in the regulation of food intake and that picrotoxin or bicuculline inhibited food intake by inhibiting gamma amino butyric acid receptors of the ventromedial hypothalamus, increasing insulin level and decreasing the gut motility.

  15. 4-methoxychalcone enhances cisplatin-induced oxidative stress and cytotoxicity by inhibiting the Nrf2/ARE-mediated defense mechanism in A549 lung cancer cells.

    Science.gov (United States)

    Lim, Juhee; Lee, Sung Ho; Cho, Sera; Lee, Ik-Soo; Kang, Bok Yun; Choi, Hyun Jin

    2013-10-01

    Nuclear factor erythroid 2-related factor 2 (Nrf2) is a key transcriptional regulator for the protection of cells against oxidative and xenobiotic stresses. Recent studies have demonstrated that high constitutive expression of Nrf2 is observed in many types of cancer cells showing resistance to anti-cancer drugs, suggesting that the suppression of overexpressed Nrf2 could be an attractive therapeutic strategy to overcome cancer drug resistance. In the present study, we aimed to find small molecule compounds that enhance the sensitivity of tumor cells to cisplatin induced cytotoxicity by suppressing Nrf2-mediated defense mechanism. A549 lung cancer cells were shown to be more resistant to the anti-cancer drug cisplatin than HEK293 cells, with higher Nrf2 signaling activity; constitutively high amounts of Nrf2-downstream target proteins were observed in A549 cells. Among the three chalcone derivatives 4-methoxy-chalcone (4-MC), hesperidin methylchalcone, and neohesperidin dihydrochalcone, 4-MC was found to suppress transcriptional activity of Nrf2 in A549 cells but to activate it in HEK293 cells. 4-MC was also shown to down-regulate expression of Nrf2 and the downstream phase II detoxifying enzyme NQO1 in A549 cells. The PI3K/Akt pathway was found to be involved in the 4-MC-induced inhibition of Nrf2/ARE activity in A549 cells. This inhibition of Nrf2 signaling results in the accelerated generation of reactive oxygen species and exacerbation of cytotoxicity in cisplatin-treated A549 cells. Taken together, these results suggest that the small molecule compound 4-MC could be used to enhance the sensitivity of tumor cells to the therapeutic effect of cisplatin through the regulation of Nrf2/ARE signaling.

  16. Ciguatoxin-induced catecholamine secretion in bovine chromaffin cells: mechanism of action and reversible inhibition by brevenal.

    Science.gov (United States)

    Nguyen-Huu, Truong D; Mattei, César; Wen, Peter J; Bourdelais, Andrea J; Lewis, Richard J; Benoit, Evelyne; Baden, Daniel G; Molgó, Jordi; Meunier, Frédéric A

    2010-10-01

    Ciguatoxin (P-CTX-1B) from the dinoflagellate Gambierdiscus toxicus, belongs to the family of polyether neurotoxins responsible for the neurological poisoning disorder ciguatera. Although it is the most widespread marine-borne disease affecting humans, there is no current FDA-approved treatment available except for symptomatic therapies. In this paper, we report that P-CTX-1B promotes catecholamine secretion from bovine chromaffin cells, an effect that is insensitive to concomitant activation of capacitative Ca(2+) entry. Moreover, we confirm that brevenal, a polyether from the dinoflagellate Karenia brevis, blocks P-CTX-1B-induced catecholamine secretion. This effect is partially reversible. Our results therefore raise the prospect of finding functional antagonists for P-CTX-1B that could be useful for the treatment of ciguatera. Copyright 2009 Elsevier Ltd. All rights reserved.

  17. Cannabidiol inhibits angiogenesis by multiple mechanisms.

    Science.gov (United States)

    Solinas, M; Massi, P; Cantelmo, A R; Cattaneo, M G; Cammarota, R; Bartolini, D; Cinquina, V; Valenti, M; Vicentini, L M; Noonan, D M; Albini, A; Parolaro, D

    2012-11-01

    Several studies have demonstrated anti-proliferative and pro-apoptotic actions of cannabinoids on various tumours, together with their anti-angiogenic properties. The non-psychoactive cannabinoid cannabidiol (CBD) effectively inhibits the growth of different types of tumours in vitro and in vivo and down-regulates some pro-angiogenic signals produced by glioma cells. As its anti-angiogenic properties have not been thoroughly investigated to date, and given its very favourable pharmacological and toxicological profile, here, we evaluated the ability of CBD to modulate tumour angiogenesis. Firstly, we evaluated the effect of CBD on human umbilical vein endothelial cell (HUVEC) proliferation and viability - through [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and FACS analysis - and in vitro motility - both in a classical Boyden chamber test and in a wound-healing assay. We next investigated CBD effects on different angiogenesis-related proteins released by HUVECs, using an angiogenesis array kit and an ELISA directed at MMP2. Then we evaluated its effects on in vitro angiogenesis in treated HUVECs invading a Matrigel layer and in HUVEC spheroids embedded into collagen gels, and further characterized its effects in vivo using a Matrigel sponge model of angiogenesis in C57/BL6 mice. CBD induced HUVEC cytostasis without inducing apoptosis, inhibited HUVEC migration, invasion and sprouting in vitro, and angiogenesis in vivo in Matrigel sponges. These effects were associated with the down-modulation of several angiogenesis-related molecules. This study reveals that CBD inhibits angiogenesis by multiple mechanisms. Its dual effect on both tumour and endothelial cells supports the hypothesis that CBD has potential as an effective agent in cancer therapy. © 2012 The Authors. British Journal of Pharmacology © 2012 The British Pharmacological Society.

  18. Glutamate-induced apoptosis in neuronal cells is mediated via caspase-dependent and independent mechanisms involving calpain and caspase-3 proteases as well as apoptosis inducing factor (AIF and this process is inhibited by equine estrogens

    Directory of Open Access Journals (Sweden)

    Bhavnani Bhagu R

    2006-06-01

    Full Text Available Abstract Background Glutamate, a major excitatory amino acid neurotransmitter, causes apoptotic neuronal cell death at high concentrations. Our previous studies have shown that depending on the neuronal cell type, glutamate-induced apoptotic cell death was associated with regulation of genes such as Bcl-2, Bax, and/or caspase-3 and mitochondrial cytochrome c. To further delineate the intracellular mechanisms, we have investigated the role of calpain, an important calcium-dependent protease thought to be involved in apoptosis along with mitochondrial apoptosis inducing factor (AIF and caspase-3 in primary cortical cells and a mouse hippocampal cell line HT22. Results Glutamate-induced apoptotic cell death in neuronal cells was associated with characteristic DNA fragmentation, morphological changes, activation of calpain and caspase-3 as well as the upregulation and/or translocation of AIF from mitochondria into cytosol and nuclei. Our results reveal that primary cortical cells and HT22 cells display different patterns of regulation of these genes/proteins. In primary cortical cells, glutamate induces activation of calpain, caspase-3 and translocation of AIF from mitochondria to cytosol and nuclei. In contrast, in HT22 cells, only the activation of calpain and upregulation and translocation of AIF occurred. In both cell types, these processes were inhibited/reversed by 17β-estradiol and Δ8,17β-estradiol with the latter being more potent. Conclusion Depending upon the neuronal cell type, at least two mechanisms are involved in glutamate-induced apoptosis: a caspase-3-dependent pathway and a caspase-independent pathway involving calpain and AIF. Since HT22 cells lack caspase-3, glutamate-induced apoptosis is mediated via the caspase-independent pathway in this cell line. Kinetics of this apoptotic pathway further indicate that calpain rather than caspase-3, plays a critical role in the glutamate-induced apoptosis. Our studies further indicate

  19. Caffeic acid attenuates the inflammatory stress induced by glycated LDL in human endothelial cells by mechanisms involving inhibition of AGE-receptor, oxidative, and endoplasmic reticulum stress.

    Science.gov (United States)

    Toma, Laura; Sanda, Gabriela M; Niculescu, Loredan S; Deleanu, Mariana; Stancu, Camelia S; Sima, Anca V

    2017-09-10

    Type 2 diabetes mellitus is a worldwide epidemic and its atherosclerotic complications determine the high morbidity and mortality of diabetic patients. Caffeic acid (CAF), a phenolic acid present in normal diets, is known for its antioxidant properties. The aim of this study was to investigate CAF's anti-inflammatory properties and its mechanism of action, using cultured human endothelial cells (HEC) incubated with glycated low-density lipoproteins (gLDL). Levels of the receptor for advanced glycation end-products (RAGE), inflammatory stress markers (C reactive protein, CRP; vascular cell adhesion molecule-1, VCAM-1; monocyte chemoattractant protein-1, MCP-1), and oxidative stress and endoplasmic reticulum stress (ERS) markers were evaluated in gLDL-exposed HEC, in the presence/absence of CAF. RAGE silencing or blocking, specific inhibitors for oxidative stress (apocynin, N-acetyl-cysteine), and ERS (salubrinal) were used. The results showed that: (i) gLDL induced CRP synthesis and secretion through mechanisms involving NADPH oxidase-dependent oxidative stress and ERS in HEC; (ii) gLDL-RAGE interaction, oxidative stress, and ERS stimulated the secretion of VCAM-1 and MCP-1 in HEC; and (iii) CAF reduced the secretion of CRP, VCAM-1, and MCP-1 in gLDL-exposed HEC by inhibiting RAGE expression, oxidative stress, and ERS. In conclusion, CAF might be a promising alternative to ameliorate a wide spectrum of disorders due to its complex mechanisms of action resulting in anti-inflammatory and antioxidative properties. © 2017 BioFactors, 43(5):685-697, 2017. © 2017 International Union of Biochemistry and Molecular Biology.

  20. Spasmolytic Mechanism of Aqueous Licorice Extract on Oxytocin-Induced Uterine Contraction through Inhibiting the Phosphorylation of Heat Shock Protein 27

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    Lu Yang

    2017-08-01

    Full Text Available Licorice derived from the roots and rhizomes of Glycyrrhiza uralensis Fisch. (Fabaceae, is one of the most widely-used traditional herbal medicines in China. It has been reported to possess significant analgesic activity for treating spastic pain. The aim of this study is to investigate the spasmolytic molecular mechanism of licorice on oxytocin-induced uterine contractions and predict the relevant bioactive constituents in the aqueous extract. The aqueous extraction from licorice inhibited the amplitude and frequency of uterine contraction in a concentration-dependent manner. A morphological examination showed that myometrial smooth muscle cells of oxytocin-stimulated group were oval-shaped and arranged irregularly, while those with a single centrally located nucleus of control and licorice-treated groups were fusiform and arranged orderly. The percentage of phosphorylation of HSP27 at Ser-15 residue increased up to 50.33% at 60 min after oxytocin stimulation. Furthermore, this increase was significantly suppressed by licorice treatment at the concentration of 0.2 and 0.4 mg/mL. Colocalization between HSP27 and α-SMA was observed in the myometrial tissues, especially along the actin bundles in the oxytocin-stimulated group. On the contrary, the colocalization was no longer shown after treatment with licorice. Additionally, employing ChemGPS-NP provided support for a preliminary assignment of liquiritigenin and isoliquiritigenin as protein kinase C (PKC inhibitors in addition to liquiritigenin, isoliquiritigenin, liquiritin and isoliquiritin as MAPK-activated protein kinase 2 (MK2 inhibitors. These assigned compounds were docked with corresponding crystal structures of respective proteins with negative and low binding energy, which indicated a high affinity and tight binding capacity for the active site of the kinases. These results suggest that licorice exerts its spasmolytic effect through inhibiting the phosphorylation of HSP27 to alter the

  1. Interleukin-4 inhibits RANKL-induced expression of NFATc1 and c-Fos: A possible mechanism for downregulation of osteoclastogenesis

    International Nuclear Information System (INIS)

    Kamel Mohamed, Saad Gad; Sugiyama, Eiji; Shinoda, Kouichiro; Hounoki, Hiroyuki; Taki, Hirofumi; Maruyama, Muneharu; Miyahara, Tatsuro; Kobayashi, Masashi

    2005-01-01

    Interleukin-4 (IL-4), an anti-inflammatory cytokine, has been shown to inhibit osteoclast differentiation. Therefore, this cytokine is considered to be a promising therapeutic applicant for bone-resorbing diseases such as rheumatoid arthritis (RA). Recently NFATc1, a transcription factor, has been shown to play critical roles in osteoclastogenesis. The aim of this study was to clarify the role of IL-4 on the intracellular signaling of NFATc1. A RAW264.7 monocyte/macrophage cell line and murine bone marrow precursors were differentiated into osteoclasts in the presence of receptor activator of nuclear factor κB ligand (RANKL) and/or macrophage colony-stimulating factor. Tartrate-resistant acid phosphatase (TRAP) staining and a pit assay using dentine were used for the identification of activated osteoclasts. The protein expression of IL-4 receptor, NFATc1, and c-Fos was determined by Western blot analysis. In addition, the gene expression of NFATc1 and c-Fos was determined by reverse transcription and polymerase chain reaction. The IL-4 receptor was constitutively expressed in RAW264.7 cells. RANKL induced osteoclast generation, as determined by TRAP staining and pit assay. IL-4 inhibited RANKL-induced osteoclastogenesis at low concentrations of 10 ng/ml and more. Interestingly, IL-4 potently inhibited RANKL-induced expression of NFATc1 at mRNA level. Furthermore, IL-4 inhibited c-Fos expression, which is shown to be responsible for NFATc1 expression, in time- and dose-dependent manners. In addition, IL-4 inhibited the RANKL-induced expression of NFATc1 and c-Fos in murine bone marrow cells. Thus, we suggest that IL-4 may downregulate osteoclastogenesis in part through inhibition of the expression of transcription factors, NFATc1 and c-Fos. These findings provide new insight into development of new medication for osteoporosis and RA

  2. Mechanisms of L-Triiodothyronine-Induced Inhibition of Synaptosomal Na+-K+-ATPase Activity in Young Adult Rat Brain Cerebral Cortex

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    Pradip K. Sarkar

    2013-01-01

    Full Text Available The role of thyroid hormones (TH in the normal functioning of adult mammalian brain is unclear. Our studies have identified synaptosomal Na+-K+-ATPase as a TH-responsive physiological parameter in adult rat cerebral cortex. L-triiodothyronine (T3 and L-thyroxine (T4 both inhibited Na+-K+-ATPase activity (but not Mg2+-ATPase activity in similar dose-dependent fashions, while other metabolites of TH were less effective. Although both T3 and the β-adrenergic agonist isoproterenol inhibited Na+-K+-ATPase activity in cerebrocortical synaptosomes in similar ways, the β-adrenergic receptor blocker propranolol did not counteract the effect of T3. Instead, propranolol further inhibited Na+-K+-ATPase activity in a dose-dependent manner, suggesting that the effect of T3 on synaptosomal Na+-K+-ATPase activity was independent of β-adrenergic receptor activation. The effect of T3 on synaptosomal Na+-K+-ATPase activity was inhibited by the α2-adrenergic agonist clonidine and by glutamate. Notably, both clonidine and glutamate activate Gi-proteins of the membrane second messenger system, suggesting a potential mechanism for the inhibition of the effects of TH. In this paper, we provide support for a nongenomic mechanism of action of TH in a neuronal membrane-related energy-linked process for signal transduction in the adult condition.

  3. Inhibition of ethylene production by putrescine alleviates aluminium-induced root inhibition in wheat plants.

    Science.gov (United States)

    Yu, Yan; Jin, Chongwei; Sun, Chengliang; Wang, Jinghong; Ye, Yiquan; Zhou, Weiwei; Lu, Lingli; Lin, Xianyong

    2016-01-08

    Inhibition of root elongation is one of the most distinct symptoms of aluminium (Al) toxicity. Although putrescine (Put) has been identified as an important signaling molecule involved in Al tolerance, it is yet unknown how Put mitigates Al-induced root inhibition. Here, the possible mechanism was investigated by using two wheat genotypes differing in Al resistance: Al-tolerant Xi Aimai-1 and Al-sensitive Yangmai-5. Aluminium caused more root inhibition in Yangmai-5 and increased ethylene production at the root apices compared to Xi Aimai-1, whereas the effects were significantly reversed by ethylene biosynthesis inhibitors. The simultaneous exposure of wheat seedlings to Al and ethylene donor, ethephon, or ethylene biosynthesis precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), increased ethylene production and aggravated root inhibition, which was more pronounced in Xi Aimai-1. In contrast, Put treatment decreased ethylene production and alleviated Al-induced root inhibition in both genotypes, and the effects were more conspicuous in Yangmai-5. Furthermore, our results indicated that Al-induced ethylene production was mediated by ACC synthase (ACS) and ACC oxidase, and that Put decreased ethylene production by inhibiting ACS. Altogether, these findings indicate that ethylene is involved in Al-induced root inhibition and this process could be alleviated by Put through inhibiting ACS activity.

  4. Analgesic Effect of Photobiomodulation on Bothrops Moojeni Venom-Induced Hyperalgesia: A Mechanism Dependent on Neuronal Inhibition, Cytokines and Kinin Receptors Modulation.

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    Nikele Nadur-Andrade

    2016-10-01

    Full Text Available Envenoming induced by Bothrops snakebites is characterized by drastic local tissue damage that involves an intense inflammatory reaction and local hyperalgesia which are not neutralized by conventional antivenom treatment. Herein, the effectiveness of photobiomodulation to reduce inflammatory hyperalgesia induced by Bothrops moojeni venom (Bmv, as well as the mechanisms involved was investigated.Bmv (1 μg was injected through the intraplantar route in the right hind paw of mice. Mechanical hyperalgesia and allodynia were evaluated by von Frey filaments at different time points after venom injection. Low level laser therapy (LLLT was applied at the site of Bmv injection at wavelength of red 685 nm with energy density of 2.2 J/cm2 at 30 min and 3 h after venom inoculation. Neuronal activation in the dorsal horn spinal cord was determined by immunohistochemistry of Fos protein and the mRNA expression of IL-6, TNF-α, IL-10, B1 and B2 kinin receptors were evaluated by Real time-PCR 6 h after venom injection. Photobiomodulation reversed Bmv-induced mechanical hyperalgesia and allodynia and decreased Fos expression, induced by Bmv as well as the mRNA levels of IL-6, TNF-α and B1 and B2 kinin receptors. Finally, an increase on IL-10, was observed following LLLT.These data demonstrate that LLLT interferes with mechanisms involved in nociception and hyperalgesia and modulates Bmv-induced nociceptive signal. The use of photobiomodulation in reducing local pain induced by Bothropic venoms should be considered as a novel therapeutic tool for the treatment of local symptoms induced after bothropic snakebites.

  5. The novel hypoxic cytotoxin, TX-2098 has antitumor effect in pancreatic cancer; possible mechanism through inhibiting VEGF and hypoxia inducible factor-1{alpha} targeted gene expression

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    Miyake, Kotaro, E-mail: hif.panc@gmail.com [Department of Surgery, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8503 (Japan); Nishioka, Masanori; Imura, Satoru; Batmunkh, Erdenebulgan [Department of Surgery, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8503 (Japan); Uto, Yoshihiro [Department of Biological Science and Technology, Institute of Socio Technosciences, The University of Tokushima Graduate School, Tokushima 770-8503 (Japan); Nagasawa, Hideko [Laboratory of Pharmaceutical and Medicinal Chemistry, Gifu Pharmaceutical University, Gifu 501-1196 (Japan); Hori, Hitoshi [Department of Biological Science and Technology, Institute of Socio Technosciences, The University of Tokushima Graduate School, Tokushima 770-8503 (Japan); Shimada, Mitsuo [Department of Surgery, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8503 (Japan)

    2012-08-01

    Tumor hypoxia has been considered to be a potential therapeutic target, because hypoxia is a common feature of solid tumors and is associated with their malignant phenotype. In the present study, we investigated the antitumor effect of a novel hypoxic cytotoxin, 3-[2-hydroxyethyl(methyl)amino]-2-quinoxalinecarbonitrile 1,4-dioxide (TX-2098) in inhibiting the expression of hypoxia inducible factor-1{alpha} (HIF-1{alpha}), and consequently vascular endothelial cell growth factor (VEGF) expression in pancreatic cancer. The antitumor effects of TX-2098 under hypoxia were tested against various human pancreatic cancer cell lines using WST-8 assay. VEGF protein induced pancreatic cancer was determined on cell-free supernatant by ELISA. Moreover, nude mice bearing subcutaneously (s.c.) or orthotopically implanted human SUIT-2 were treated with TX-2098. Tumor volume, survival and expression of HIF-1 and associated molecules were evaluated in treatment versus control groups. In vitro, TX-2098 inhibited the proliferation of various pancreatic cancer cell lines. In s.c model, tumors from nude mice injected with pancreatic cancer cells and treated with TX-2098 showed significant reductions in volume (P < 0.01 versus control). Quantitative real-time reverse transcription-PCR analysis revealed that TX-2098 significantly inhibited mRNA expression of the HIF-1 associated molecules, VEGF, glucose transporter 1 and Aldolase A (P < 0.01 versus control). These treatments also prolong the survival in orthotopic models. These results suggest that the effect of TX-2098 in pancreatic cancer might be correlated with the expression of VEGF and HIF-1 targeted molecules. -- Highlights: Black-Right-Pointing-Pointer We designed and synthesized novel hypoxic cytoxin, TX-2098. Black-Right-Pointing-Pointer TX-2098 inhibited the proliferation of human pancreatic cancer cells than TPZ. Black-Right-Pointing-Pointer TX-2098 reduced VEGF protein level than TPZ. Black-Right-Pointing-Pointer TX-2098

  6. The novel hypoxic cytotoxin, TX-2098 has antitumor effect in pancreatic cancer; possible mechanism through inhibiting VEGF and hypoxia inducible factor-1α targeted gene expression

    International Nuclear Information System (INIS)

    Miyake, Kotaro; Nishioka, Masanori; Imura, Satoru; Batmunkh, Erdenebulgan; Uto, Yoshihiro; Nagasawa, Hideko; Hori, Hitoshi; Shimada, Mitsuo

    2012-01-01

    Tumor hypoxia has been considered to be a potential therapeutic target, because hypoxia is a common feature of solid tumors and is associated with their malignant phenotype. In the present study, we investigated the antitumor effect of a novel hypoxic cytotoxin, 3-[2-hydroxyethyl(methyl)amino]-2-quinoxalinecarbonitrile 1,4-dioxide (TX-2098) in inhibiting the expression of hypoxia inducible factor-1α (HIF-1α), and consequently vascular endothelial cell growth factor (VEGF) expression in pancreatic cancer. The antitumor effects of TX-2098 under hypoxia were tested against various human pancreatic cancer cell lines using WST-8 assay. VEGF protein induced pancreatic cancer was determined on cell-free supernatant by ELISA. Moreover, nude mice bearing subcutaneously (s.c.) or orthotopically implanted human SUIT-2 were treated with TX-2098. Tumor volume, survival and expression of HIF-1 and associated molecules were evaluated in treatment versus control groups. In vitro, TX-2098 inhibited the proliferation of various pancreatic cancer cell lines. In s.c model, tumors from nude mice injected with pancreatic cancer cells and treated with TX-2098 showed significant reductions in volume (P < 0.01 versus control). Quantitative real-time reverse transcription-PCR analysis revealed that TX-2098 significantly inhibited mRNA expression of the HIF-1 associated molecules, VEGF, glucose transporter 1 and Aldolase A (P < 0.01 versus control). These treatments also prolong the survival in orthotopic models. These results suggest that the effect of TX-2098 in pancreatic cancer might be correlated with the expression of VEGF and HIF-1 targeted molecules. -- Highlights: ► We designed and synthesized novel hypoxic cytoxin, TX-2098. ► TX-2098 inhibited the proliferation of human pancreatic cancer cells than TPZ. ► TX-2098 reduced VEGF protein level than TPZ. ► TX-2098 inhibited mRNA expression of VEGF, GLUT1 and Aldolase A, not HIF-1α. ► TX-2098 improved the survival in

  7. The novel hypoxic cytotoxin, TX-2098 has antitumor effect in pancreatic cancer; possible mechanism through inhibiting VEGF and hypoxia inducible factor-1α targeted gene expression.

    Science.gov (United States)

    Miyake, Kotaro; Nishioka, Masanori; Imura, Satoru; Batmunkh, Erdenebulgan; Uto, Yoshihiro; Nagasawa, Hideko; Hori, Hitoshi; Shimada, Mitsuo

    2012-08-01

    Tumor hypoxia has been considered to be a potential therapeutic target, because hypoxia is a common feature of solid tumors and is associated with their malignant phenotype. In the present study, we investigated the antitumor effect of a novel hypoxic cytotoxin, 3-[2-hydroxyethyl(methyl)amino]-2-quinoxalinecarbonitrile 1,4-dioxide (TX-2098) in inhibiting the expression of hypoxia inducible factor-1α (HIF-1α), and consequently vascular endothelial cell growth factor (VEGF) expression in pancreatic cancer. The antitumor effects of TX-2098 under hypoxia were tested against various human pancreatic cancer cell lines using WST-8 assay. VEGF protein induced pancreatic cancer was determined on cell-free supernatant by ELISA. Moreover, nude mice bearing subcutaneously (s.c.) or orthotopically implanted human SUIT-2 were treated with TX-2098. Tumor volume, survival and expression of HIF-1 and associated molecules were evaluated in treatment versus control groups. In vitro, TX-2098 inhibited the proliferation of various pancreatic cancer cell lines. In s.c model, tumors from nude mice injected with pancreatic cancer cells and treated with TX-2098 showed significant reductions in volume (P<0.01 versus control). Quantitative real-time reverse transcription-PCR analysis revealed that TX-2098 significantly inhibited mRNA expression of the HIF-1 associated molecules, VEGF, glucose transporter 1 and Aldolase A (P<0.01 versus control). These treatments also prolong the survival in orthotopic models. These results suggest that the effect of TX-2098 in pancreatic cancer might be correlated with the expression of VEGF and HIF-1 targeted molecules. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Global inhibition of reactive oxygen species (ROS inhibits paclitaxel-induced painful peripheral neuropathy.

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    Mehmet Fidanboylu

    Full Text Available Paclitaxel (Taxol® is a widely used chemotherapeutic agent that has a major dose limiting side-effect of painful peripheral neuropathy. Currently there is no effective therapy for the prevention or treatment of chemotherapy-induced painful peripheral neuropathies. Evidence for mitochondrial dysfunction during paclitaxel-induced pain was previously indicated with the presence of swollen and vacuolated neuronal mitochondria. As mitochondria are a major source of reactive oxygen species (ROS, the aim of this study was to examine whether pharmacological inhibition of ROS could reverse established paclitaxel-induced pain or prevent the development of paclitaxel-induced pain. Using a rat model of paclitaxel-induced pain (intraperitoneal 2 mg/kg paclitaxel on days 0, 2, 4 & 6, the effects of a non-specific ROS scavenger, N-tert-Butyl-α-phenylnitrone (PBN and a superoxide selective scavenger, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL were compared. Systemic 100 mg/kg PBN administration markedly inhibited established paclitaxel-induced mechanical hypersensitivity to von Frey 8 g and 15 g stimulation and cold hypersensitivity to plantar acetone application. Daily systemic administration of 50 mg/kg PBN (days -1 to 13 completely prevented mechanical hypersensitivity to von Frey 4 g and 8 g stimulation and significantly attenuated mechanical hypersensitivity to von Frey 15 g. Systemic 100 mg/kg TEMPOL had no effect on established paclitaxel-induced mechanical or cold hypersensitivity. High dose (250 mg/kg systemic TEMPOL significantly inhibited mechanical hypersensitivity to von Frey 8 g & 15 g, but to a lesser extent than PBN. Daily systemic administration of 100 mg/kg TEMPOL (day -1 to 12 did not affect the development of paclitaxel-induced mechanical hypersensitivity. These data suggest that ROS play a causal role in the development and maintenance of paclitaxel-induced pain, but such effects cannot be attributed to superoxide radicals

  9. Toll-like receptor 7 agonist GS-9620 induces prolonged inhibition of HBV via a type I interferon-dependent mechanism.

    Science.gov (United States)

    Niu, Congrong; Li, Li; Daffis, Stephane; Lucifora, Julie; Bonnin, Marc; Maadadi, Sarah; Salas, Eduardo; Chu, Ruth; Ramos, Hilario; Livingston, Christine M; Beran, Rudolf K; Garg, Abhishek V; Balsitis, Scott; Durantel, David; Zoulim, Fabien; Delaney, William E; Fletcher, Simon P

    2018-05-01

    GS-9620, an oral agonist of toll-like receptor 7 (TLR7), is in clinical development for the treatment of chronic hepatitis B (CHB). GS-9620 was previously shown to induce prolonged suppression of serum viral DNA and antigens in the woodchuck and chimpanzee models of CHB. Herein, we investigated the molecular mechanisms that contribute to the antiviral response to GS-9620 using in vitro models of hepatitis B virus (HBV) infection. Cryopreserved primary human hepatocytes (PHH) and differentiated HepaRG (dHepaRG) cells were infected with HBV and treated with GS-9620, conditioned media from human peripheral blood mononuclear cells treated with GS-9620 (GS-9620 conditioned media [GS-9620-CM]), or other innate immune stimuli. The antiviral and transcriptional response to these agents was determined. GS-9620 had no antiviral activity in HBV-infected PHH, consistent with low level TLR7 mRNA expression in human hepatocytes. In contrast, GS-9620-CM induced prolonged reduction of HBV DNA, RNA, and antigen levels in PHH and dHepaRG cells via a type I interferon (IFN)-dependent mechanism. GS-9620-CM did not reduce covalently closed circular DNA (cccDNA) levels in either cell type. Transcriptional profiling demonstrated that GS-9620-CM strongly induced various HBV restriction factors - although not APOBEC3A or the Smc5/6 complex - and indicated that established HBV infection does not modulate innate immune sensing or signaling in cryopreserved PHH. GS-9620-CM also induced expression of immunoproteasome subunits and enhanced presentation of an immunodominant viral peptide in HBV-infected PHH. Type I IFN induced by GS-9620 durably suppressed HBV in human hepatocytes without reducing cccDNA levels. Moreover, HBV antigen presentation was enhanced, suggesting additional components of the TLR7-induced immune response played a role in the antiviral response to GS-9620 in animal models of CHB. GS-9620 is a drug currently being tested in clinical trials for the treatment of chronic

  10. 15, 16-Dihydrotanshinone I Inhibits Hemangiomas through Inducing Pro-apoptotic and Anti-angiogenic Mechanisms in Vitro and in Vivo

    Directory of Open Access Journals (Sweden)

    Yihong Cai

    2018-01-01

    Full Text Available Infantile hemangioma (IH is a common and benign vascular neoplasms, which has a high incidence in children. Although IH is benign, some patients experience complications such as pain, functional impairment, and permanent disfigurement. Treatment options for IH include corticosteroids, surgery, vincristine, interferon or cyclophosphamide. However, none of these modalities are ideal due to restrictions or potential serious side effects. There is thus a great need to explore novel treatments for IH with less side effects. Angiogenesis, vasculogenesis and tumorigenesis are the main features of IH. Tanshen is mostly used in Chinese traditional medicine to treat hematological abnormalities. Therefore, the aim of our study was to evaluate anti-proliferation and anti-angiogenesis effects on hemangiomas cells by extracted Tanshen compounds compared with propranolol, the first-line treatment for IH currently, both in vitro and in vivo. Cell viability, apoptosis, protein expression and anti-angiogenesis were analyzed by CCK8, Annexin V staining, Western blot and tube formation, respectively. The anti-tumor activity in vivo was evaluated using a mouse xenograft model. Fourteen major compounds extracting from Tanshen were screened for their ability to inhibit hemangiomas cells. Of the 14 compounds investigated, 15,16-Dihydrotanshinone I (DHTS was the most potent modulator of EOMA cell biology. DHTS could significantly decrease EOMA cells proliferation by inducing cell apoptosis, which is much more efficient than propranolol in vitro. DHTS increased the expression of several apoptosis-related proteins, including caspase9, caspase3, PARP, AIF, BAX, cytochrome c, caspase8 and FADD and significantly inhibited angiogenesis, as indicated by reduced tube formation and diminished expression of vascular endothelial cell growth factor receptor 2 and matrix metalloproteinase 9. In nude mice xenograft experiment, DHTS (10 mg/kg could significantly inhibit the tumor

  11. Sphingosine 1-Phosphate Induces Platelet/Endothelial Cell Adhesion Molecule-1 Tyrosine Phosphorylation in Bovine Aortic Endothelial Cells through a PP2-Inhibitable Mechanism

    Directory of Open Access Journals (Sweden)

    Yu-Ting Huang

    2007-12-01

    Full Text Available Sphingosine-1-phosphate (S1P is a low-molecular-weight phospholipid derivative released by activated platelets. S1P transduces signals through a family of G protein-coupled receptors to modulate various physiological behaviors of endothelial cells. Platelet/endothelial cell adhesion molecule-1 (PECAM-1; CD31 is a 130-kDa protein expressed on the surfaces of leukocytes, platelets, and endothelial cells. Upon PECAM-1 activation, its cytoplasmic tyrosine residues become phosphorylated and bind with SH2 domain-containing proteins, thus leading to the downstream functions mediated by PECAM-1. In the present study, we found that S1P induced PECAM-1 tyrosine phosphorylation and SHP-2 association in bovine aortic endothelial cells (BAECs by immunoprecipitation and western blotting. The pretreatment of BAECs with a series of chemical inhibitors to determine the signaling pathway showed that the PECAM-1 phosphorylation was inhibited by PP2, indicating the participation of Src family kinases. These results demonstrated that S1P induced PECAM-1 tyrosine phosphorylation in BAECs through mediation of Src family kinases, and this may regulate the physiological behaviors of endothelial cells.

  12. A novel small molecule, Rosline, inhibits growth and induces caspase-dependent apoptosis in human lung cancer cells A549 through a reactive oxygen species-dependent mechanism.

    Science.gov (United States)

    Zhao, Ting; Feng, Yang; Jin, Wenling; Pan, Hui; Li, Haizhou; Zhao, Yang

    2016-06-01

    Chemical screening using synthetic small molecule libraries has provided a huge amount of novel active molecules. It generates lead compound for drug development and brings focus on molecules for mechanistic investigations on many otherwise intangible biological processes. In this study, using non-small cell lung cancer cell A549 to screen against a structurally novel and diverse synthetic small molecule library of 2,400 compounds, we identified a molecule named rosline that has strong anti-proliferation activity on A549 cells with a 50% cell growth inhibitory concentration (IC50 ) of 2.87 ± 0.39 µM. We showed that rosline treatment increased the number of Annexin V-positive staining cell, as well as G2/M arrest in their cell cycle progression. Further, we have demonstrated that rosline induces a decrease of mitochondrial membrane potential (Δφm ) and an increase of caspases 3/7 and 9 activities in A549 cells, although having no effect on the activity of caspase 8. Moreover, we found that rosline could induce the production of reactive oxygen species (ROS) and inhibit the phosphorylation of signaling molecule Akt in A549 cells. Alternatively, an antioxidant N-acetyl-L-cysteine (NAC) significantly attenuated rosline's effects on the mitochondrial membrane potential, caspases 3/7 and 9 activities, cell viabilities and the phosphorylation of Akt. Our results demonstrated that ROS played an important role in the apoptosis of A549 cells induced by rosline. © 2016 International Federation for Cell Biology.

  13. Resveratrol, an extract of red wine, inhibits lipopolysaccharide induced airway neutrophilia and inflammatory mediators through an NF-kappaB-independent mechanism.

    Science.gov (United States)

    Birrell, M A; McCluskie, K; Wong, S; Donnelly, L E; Barnes, P J; Belvisi, M G

    2005-05-01

    Consumption of a naturally occurring polyphenol, resveratrol, in particular through drinking moderate amounts of red wine, has been suggested to be beneficial to health. A plethora of in vitro studies published demonstrate various anti-inflammatory actions of resveratrol. The aim of this research was to determine whether any of these anti-inflammatory effects translate in vivo in a rodent model of LPS induced airway inflammation. Resveratrol reduced lung tissue neutrophilia to a similar magnitude as that achieved by treatment with budesonide. This was associated with a reduction in pro-inflammatory cytokines and prostanoid levels. Interestingly, the reduction did not appear to be due to an impact on NF-kappaB activation or the expression of the respective genes as suggested by various in vitro publications. These results suggest that resveratrol may possess anti-inflammatory properties via a novel mechanism. Elucidation of this mechanism may lead to potential new therapies for the treatment of chronic inflammation.

  14. Effects of chronic Akt/mTOR inhibition by rapamycin on mechanical overload-induced hypertrophy and myosin heavy chain transition in masseter muscle.

    Science.gov (United States)

    Umeki, Daisuke; Ohnuki, Yoshiki; Mototani, Yasumasa; Shiozawa, Kouichi; Fujita, Takayuki; Nakamura, Yoshiki; Saeki, Yasutake; Okumura, Satoshi

    2013-01-01

    To examine the effects of the Akt/mammalian target of rapamycin (mTOR) pathway on masseter muscle hypertrophy and myosin heavy chain (MHC) transition in response to mechanical overload, we analyzed the effects of bite-opening (BO) on the hypertrophy and MHC composition of masseter muscle of BO-rats treated or not treated with rapamycin (RAPA), a selective mTOR inhibitor. The masseter muscle weight in BO-rats was significantly greater than that in controls, and this increase was attenuated by RAPA treatment. Expression of slow-twitch MHC isoforms was significantly increased in BO-rats with/without RAPA treatment, compared with controls, but the magnitude of the increase was much smaller in RAPA-treated BO-rats. Phosphorylation of p44/42 MAPK (ERK1/2), which preserves fast-twitch MHC isoforms in skeletal muscle, was significantly decreased in BO-rats, but the decrease was abrogated by RAPA treatment. Calcineurin signaling is known to be important for masseter muscle hypertrophy and fast-to-slow MHC isoform transition, but expression of known calcineurin activity modulators was unaffected by RAPA treatment. Taken together, these results indicate that the Akt/mTOR pathway is involved in both development of masseter muscle hypertrophy and fast-to-slow MHC isoform transition in response to mechanical overload with inhibition of the ERK1/2 pathway and operates independently of the calcineurin pathway.

  15. Berberine activates Nrf2 nuclear translocation and inhibits apoptosis induced by high glucose in renal tubular epithelial cells through a phosphatidylinositol 3-kinase/Akt-dependent mechanism.

    Science.gov (United States)

    Zhang, Xiuli; Liang, Dan; Lian, Xu; Jiang, Yan; He, Hui; Liang, Wei; Zhao, Yue; Chi, Zhi-Hong

    2016-06-01

    Apoptosis of tubular epithelial cells is a major feature of diabetic kidney disease, and hyperglycemia triggers the generation of free radicals and oxidant stress in tubular cells. Berberine (BBR) is identified as a potential anti-diabetic herbal medicine due to its beneficial effects on insulin sensitivity, glucose metabolism and glycolysis. In this study, the underlying mechanisms involved in the protective effects of BBR on high glucose-induced apoptosis were explored using cultured renal tubular epithelial cells (NRK-52E cells) and human kidney proximal tubular cell line (HK-2 cells). We identified the pivotal role of phosphatidylinositol 3-kinase (PI3K)/Akt in BBR cellular defense mechanisms and revealed the novel effect of BBR on nuclear factor (erythroid-derived 2)-related factor-2 (Nrf2) and heme oxygenase (HO)-1 in NRK-52E and HK-2 cells. BBR attenuated reactive oxygen species production, antioxidant defense (GSH and SOD) and oxidant-sensitive proteins (Nrf2 and HO-1), which also were blocked by LY294002 (an inhibitor of PI3K) in HG-treated NRK-52E and HK-2 cells. Furthermore, BBR improved mitochondrial function by increasing mitochondrial membrane potential. BBR-induced anti-apoptotic function was demonstrated by decreasing apoptotic proteins (cytochrome c, Bax, caspase3 and caspase9). All these findings suggest that BBR exerts the anti-apoptosis effects through activation of PI3K/Akt signal pathways and leads to activation of Nrf2 and induction of Nrf2 target genes, and consequently protecting the renal tubular epithelial cells from HG-induced apoptosis.

  16. Autophagy contributes to gefitinib-induced glioma cell growth inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Cheng-Yi [Department of Surgery, Fong-Yuan Hospital, Taichung 420, Taiwan (China); Graduate Institute of Pharmaceutical Science and Technology, Central Taiwan University of Science and Technology, Taichung 406, Taiwan (China); Kuan, Yu-Hsiang [Department of Pharmacology, School of Medicine, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Pharmacy, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); Ou, Yen-Chuan; Li, Jian-Ri [Division of Urology, Taichung Veterans General Hospital, Taichung 407, Taiwan (China); Wu, Chih-Cheng [Department of Anesthesiology, Taichung Veterans General Hospital, Taichung 407, Taiwan (China); Department of Financial and Computational Mathematics, Providence University, Taichung 433, Taiwan (China); Pan, Pin-Ho [Department of Pediatrics, Tungs’ Taichung MetroHarbor Hospital, Taichung 435, Taiwan (China); Chen, Wen-Ying [Department of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan (China); Huang, Hsuan-Yi [Department of Surgery, Fong-Yuan Hospital, Taichung 420, Taiwan (China); Chen, Chun-Jung, E-mail: cjchen@vghtc.gov.tw [Department of Medical Research, Taichung Veterans General Hospital, Taichung 407, Taiwan (China); Institute of Biomedical Sciences, National Chung Hsing University, Taichung 402, Taiwan (China); Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung 402, Taiwan (China); Center for General Education, Tunghai University, Taichung 407, Taiwan (China); Department of Nursing, HungKuang University, Taichung 433, Taiwan (China)

    2014-09-10

    Epidermal growth factor receptor tyrosine kinase inhibitors, including gefitinib, have been evaluated in patients with malignant gliomas. However, the molecular mechanisms involved in gefitinib-mediated anticancer effects against glioma are incompletely understood. In the present study, the cytostatic potential of gefitinib was demonstrated by the inhibition of glioma cell growth, long-term clonogenic survival, and xenograft tumor growth. The cytostatic consequences were accompanied by autophagy, as evidenced by monodansylcadaverine staining of acidic vesicle formation, conversion of microtubule-associated protein-1 light chain 3-II (LC3-II), degradation of p62, punctate pattern of GFP-LC3, and conversion of GFP-LC3 to cleaved-GFP. Autophagy inhibitor 3-methyladenosine and chloroquine and genetic silencing of LC3 or Beclin 1 attenuated gefitinib-induced growth inhibition. Gefitinib-induced autophagy was not accompanied by the disruption of the Akt/mammalian target of rapamycin signaling. Instead, the activation of liver kinase-B1/AMP-activated protein kinase (AMPK) signaling correlated well with the induction of autophagy and growth inhibition caused by gefitinib. Silencing of AMPK suppressed gefitinib-induced autophagy and growth inhibition. The crucial role of AMPK activation in inducing glioma autophagy and growth inhibition was further supported by the actions of AMP mimetic AICAR. Gefitinib was shown to be capable of reducing the proliferation of glioma cells, presumably by autophagic mechanisms involving AMPK activation. - Highlights: • Gefitinib causes cytotoxic and cytostatic effect on glioma. • Gefitinib induces autophagy. • Gefitinib causes cytostatic effect through autophagy. • Gefitinib induces autophagy involving AMPK.

  17. Autophagy contributes to gefitinib-induced glioma cell growth inhibition

    International Nuclear Information System (INIS)

    Chang, Cheng-Yi; Kuan, Yu-Hsiang; Ou, Yen-Chuan; Li, Jian-Ri; Wu, Chih-Cheng; Pan, Pin-Ho; Chen, Wen-Ying; Huang, Hsuan-Yi; Chen, Chun-Jung

    2014-01-01

    Epidermal growth factor receptor tyrosine kinase inhibitors, including gefitinib, have been evaluated in patients with malignant gliomas. However, the molecular mechanisms involved in gefitinib-mediated anticancer effects against glioma are incompletely understood. In the present study, the cytostatic potential of gefitinib was demonstrated by the inhibition of glioma cell growth, long-term clonogenic survival, and xenograft tumor growth. The cytostatic consequences were accompanied by autophagy, as evidenced by monodansylcadaverine staining of acidic vesicle formation, conversion of microtubule-associated protein-1 light chain 3-II (LC3-II), degradation of p62, punctate pattern of GFP-LC3, and conversion of GFP-LC3 to cleaved-GFP. Autophagy inhibitor 3-methyladenosine and chloroquine and genetic silencing of LC3 or Beclin 1 attenuated gefitinib-induced growth inhibition. Gefitinib-induced autophagy was not accompanied by the disruption of the Akt/mammalian target of rapamycin signaling. Instead, the activation of liver kinase-B1/AMP-activated protein kinase (AMPK) signaling correlated well with the induction of autophagy and growth inhibition caused by gefitinib. Silencing of AMPK suppressed gefitinib-induced autophagy and growth inhibition. The crucial role of AMPK activation in inducing glioma autophagy and growth inhibition was further supported by the actions of AMP mimetic AICAR. Gefitinib was shown to be capable of reducing the proliferation of glioma cells, presumably by autophagic mechanisms involving AMPK activation. - Highlights: • Gefitinib causes cytotoxic and cytostatic effect on glioma. • Gefitinib induces autophagy. • Gefitinib causes cytostatic effect through autophagy. • Gefitinib induces autophagy involving AMPK

  18. Mechanism study on inorganic oxidants induced inhibition of Ru(bpy)₃²+ electrochemiluminescence and its application for sensitive determination of some inorganic oxidants.

    Science.gov (United States)

    Qiu, Bin; Xue, Lingling; Wu, Yanping; Lin, Zhenyu; Guo, Longhua; Chen, Guonan

    2011-07-15

    Inhibited Ru(bpy)(3)(2+) electrochemiluminescence by inorganic oxidants is investigated. Results showed that a number of inorganic oxidants can quench the ECL of Ru(bpy)(3)(2+)/tri-n-propylamine (TPrA) system, and the logarithm of the decrease in ECL intensity (ΔI) was proportional to the logarithm of analyte concentrations. Based on which, a sensitive approach for detection of these inorganic oxidants was established, e.g. the log-log plots of ΔI versus the concentration of MnO(4)(-), Cr(2)O(7)(2-) and Fe(CN)(6)(3-) are linear in the range of 1×10(-7) to 3×10(-4)M for MnO(4)(-) and Cr(2)O(7)(2-), and 1×10(-7) to 1×10(-4)M for Fe(CN)(6)(3-), with the limit of detection (LOD) of 8.0×10(-8)M, 2×10(-8)M, and 1×10(-8)M, respectively. A series of experiments such as a comparison of the inhibitory effect of different compounds on Ru(bpy)(3)(2+)/TPrA ECL, ECL emission spectra, UV-Vis absorption spectra etc. were investigated in order to discover how these inorganic analytes quench the ECL of Ru(bpy)(3)(2+)/TPrA system. A mechanism based on consumption of TPrA intermediate (TPrA(·)) by inorganic oxidants was proposed. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Diclofenac inhibits 27-hydroxycholesterol-induced inflammation.

    Science.gov (United States)

    Kim, Bo-Young; Son, Yonghae; Eo, Seong-Kug; Park, Young Chul; Kim, Koanhoi

    2016-09-23

    27-Hydroxycholesterol (27OHChol) is a cholesterol oxidation product that induces inflammation. In the current study we investigated the effects of diclofenac on inflammatory responses caused by 27OHChol using human monocyte/macrophage (THP-1) cells. Transcription and secretion of CCL2, CCL3, and CCL4 chemokines enhanced by 27OHChol were significantly attenuated by diclofenac in a concentration dependent manner. Migrations of monocytic cells and CCR5-positive Jurkat T cells were reduced proportionally to the concentrations of diclofenac. Superproduction of CCL2 and monocytic cell migration induced by 27OHChol plus LPS were significantly attenuated by diclofenac. Diclofenac also attenuated transcription of MMP-9 and release of its active gene product. These results indicate that diclofenac inhibits 27OHChol-induced inflammatory responses, thereby suppressing inflammation in a milieu rich in cholesterol oxidation products. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Insulin-Inducible SMILE Inhibits Hepatic Gluconeogenesis.

    Science.gov (United States)

    Lee, Ji-Min; Seo, Woo-Young; Han, Hye-Sook; Oh, Kyoung-Jin; Lee, Yong-Soo; Kim, Don-Kyu; Choi, Seri; Choi, Byeong Hun; Harris, Robert A; Lee, Chul-Ho; Koo, Seung-Hoi; Choi, Hueng-Sik

    2016-01-01

    The role of a glucagon/cAMP-dependent protein kinase-inducible coactivator PGC-1α signaling pathway is well characterized in hepatic gluconeogenesis. However, an opposing protein kinase B (PKB)/Akt-inducible corepressor signaling pathway is unknown. A previous report has demonstrated that small heterodimer partner-interacting leucine zipper protein (SMILE) regulates the nuclear receptors and transcriptional factors that control hepatic gluconeogenesis. Here, we show that hepatic SMILE expression was induced by feeding in normal mice but not in db/db and high-fat diet (HFD)-fed mice. Interestingly, SMILE expression was induced by insulin in mouse primary hepatocyte and liver. Hepatic SMILE expression was not altered by refeeding in liver-specific insulin receptor knockout (LIRKO) or PKB β-deficient (PKBβ(-/-)) mice. At the molecular level, SMILE inhibited hepatocyte nuclear factor 4-mediated transcriptional activity via direct competition with PGC-1α. Moreover, ablation of SMILE augmented gluconeogenesis and increased blood glucose levels in mice. Conversely, overexpression of SMILE reduced hepatic gluconeogenic gene expression and ameliorated hyperglycemia and glucose intolerance in db/db and HFD-fed mice. Therefore, SMILE is an insulin-inducible corepressor that suppresses hepatic gluconeogenesis. Small molecules that enhance SMILE expression would have potential for treating hyperglycemia in diabetes. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  1. Fluoxetine-induced inhibition of synaptosomal [3H]5-HT release: Possible Ca2+-channel inhibition

    International Nuclear Information System (INIS)

    Stauderman, K.A.; Gandhi, V.C.; Jones, D.J.

    1992-01-01

    Fluoxetine, a selective 5-Ht uptake inhibitor, inhibited 15 mM K + -induced [ 3 H]5-HT release from rat spinal cord and cortical synaptosomes at concentrations > 0.5 uM. This effect reflected a property shared by another selective 5-HT uptake inhibitor paroxetine but not by less selective uptake inhibitors such as amitriptyline, desipramine, imipramine or nortriptyline. Inhibition of release by fluoxetine was inversely related to both the concentration of K + used to depolarize the synaptosomes and the concentration of external Ca 2+ . Experiments aimed at determining a mechanism of action revealed that fluoxetine did not inhibit voltage-independent release of [ 3 H]5-HT release induced by the Ca 2+ -ionophore A 23187 or Ca 2+ -independent release induced by fenfluramine. Moreover the 5-HT autoreceptor antagonist methiothepin did not reverse the inhibitory actions of fluoxetine on K + -induced release. Further studies examined the effects of fluoxetine on voltage-dependent Ca 2+ channels and Ca 2+ entry

  2. Madecassoside Inhibits Melanin Synthesis by Blocking Ultraviolet-Induced Inflammation

    Directory of Open Access Journals (Sweden)

    Eunsun Jung

    2013-12-01

    Full Text Available Madecassoside (MA, a pentacyclic triterpene isolated from Centella asitica (L., is used as a therapeutic agent in wound healing and also as an anti-inflammatory and anti-aging agent. However, the involvement of MA in skin-pigmentation has not been reported. This study was conducted to investigate the effects of MA on ultraviolet (UV-induced melanogenesis and mechanisms in a co-culture system of keratinocytes and melanocytes. MA significantly inhibited UVR-induced melanin synthesis and melanosome transfer in the co-culture system. These effects were further demonstrated by the MA-induced inhibition of protease-activated receptor-2 expression and its signaling pathway, cyclooxygenase-2, prostaglandin E2 and prostaglandin F2 alpha in keratinocytes. The clinical efficacy of MA was confirmed on artificially tanned human skin. MA significantly reduced UV-induced melanin index at 8 weeks after topical application. Overall, the study demonstrated significant benefits of MA use in the inhibition of hyperpigmentation caused by UV irradiation.

  3. Mechanisms of cadmium induced genomic instability

    Energy Technology Data Exchange (ETDEWEB)

    Filipic, Metka, E-mail: metka.filipic@nib.si [National Institute of Biology, Department for Genetic Toxicology and Cancer Biology, Ljubljana (Slovenia)

    2012-05-01

    Cadmium is an ubiquitous environmental contaminant that represents hazard to humans and wildlife. It is found in the air, soil and water and, due to its extremely long half-life, accumulates in plants and animals. The main source of cadmium exposure for non-smoking human population is food. Cadmium is primarily toxic to the kidney, but has been also classified as carcinogenic to humans by several regulatory agencies. Current evidence suggests that exposure to cadmium induces genomic instability through complex and multifactorial mechanisms. Cadmium dose not induce direct DNA damage, however it induces increase in reactive oxygen species (ROS) formation, which in turn induce DNA damage and can also interfere with cell signalling. More important seems to be cadmium interaction with DNA repair mechanisms, cell cycle checkpoints and apoptosis as well as with epigenetic mechanisms of gene expression control. Cadmium mediated inhibition of DNA repair mechanisms and apoptosis leads to accumulation of cells with unrepaired DNA damage, which in turn increases the mutation rate and thus genomic instability. This increases the probability of developing not only cancer but also other diseases associated with genomic instability. In the in vitro experiments cadmium induced effects leading to genomic instability have been observed at low concentrations that were comparable to those observed in target organs and tissues of humans that were non-occupationally exposed to cadmium. Therefore, further studies aiming to clarify the relevance of these observations for human health risks due to cadmium exposure are needed.

  4. Mechanisms of cadmium induced genomic instability

    International Nuclear Information System (INIS)

    Filipič, Metka

    2012-01-01

    Cadmium is an ubiquitous environmental contaminant that represents hazard to humans and wildlife. It is found in the air, soil and water and, due to its extremely long half-life, accumulates in plants and animals. The main source of cadmium exposure for non-smoking human population is food. Cadmium is primarily toxic to the kidney, but has been also classified as carcinogenic to humans by several regulatory agencies. Current evidence suggests that exposure to cadmium induces genomic instability through complex and multifactorial mechanisms. Cadmium dose not induce direct DNA damage, however it induces increase in reactive oxygen species (ROS) formation, which in turn induce DNA damage and can also interfere with cell signalling. More important seems to be cadmium interaction with DNA repair mechanisms, cell cycle checkpoints and apoptosis as well as with epigenetic mechanisms of gene expression control. Cadmium mediated inhibition of DNA repair mechanisms and apoptosis leads to accumulation of cells with unrepaired DNA damage, which in turn increases the mutation rate and thus genomic instability. This increases the probability of developing not only cancer but also other diseases associated with genomic instability. In the in vitro experiments cadmium induced effects leading to genomic instability have been observed at low concentrations that were comparable to those observed in target organs and tissues of humans that were non-occupationally exposed to cadmium. Therefore, further studies aiming to clarify the relevance of these observations for human health risks due to cadmium exposure are needed.

  5. Smad7 induces tumorigenicity by blocking TGF-beta-induced growth inhibition and apoptosis.

    Science.gov (United States)

    Halder, Sunil K; Beauchamp, R Daniel; Datta, Pran K

    2005-07-01

    Smad proteins play a key role in the intracellular signaling of the transforming growth factor beta (TGF-beta) superfamily of extracellular polypeptides that initiate signaling to regulate a wide variety of biological processes. The inhibitory Smad, Smad7, has been shown to function as intracellular antagonists of TGF-beta family signaling and is upregulated in several cancers. To determine the effect of Smad7-mediated blockade of TGF-beta signaling, we have stably expressed Smad7 in a TGF-beta-sensitive, well-differentiated, and non-tumorigenic cell line, FET, that was derived from human colon adenocarcinoma. Smad7 inhibits TGF-beta-induced transcriptional responses by blocking complex formation between Smad 2/3 and Smad4. While Smad7 has no effect on TGF-beta-induced activation of p38 MAPK and ERK, it blocks the phosphorylation of Akt by TGF-beta and enhances TGF-beta-induced phosphorylation of c-Jun. FET cells expressing Smad7 show anchorage-independent growth and enhance tumorigenicity in athymic nude mice. Smad7 blocks TGF-beta-induced growth inhibition by preventing TGF-beta-induced G1 arrest. Smad7 inhibits TGF-beta-mediated downregulation of c-Myc, CDK4, and Cyclin D1, and suppresses the expression of p21(Cip1). As a result, Smad7 inhibits TGF-beta-mediated downregulation of Rb phosphorylation. Furthermore, Smad7 inhibits the apoptosis of these cells. Together, Smad7 may increase the tumorigenicity of FET cells by blocking TGF-beta-induced growth inhibition and by inhibiting apoptosis. Thus, this study provides a mechanism by which a portion of human colorectal tumors may become refractory to tumor-suppressive actions of TGF-beta that might result in increased tumorigenicity.

  6. Retrieval-Induced Inhibition in Short-Term Memory.

    Science.gov (United States)

    Kang, Min-Suk; Choi, Joongrul

    2015-07-01

    We used a visual illusion called motion repulsion as a model system for investigating competition between two mental representations. Subjects were asked to remember two random-dot-motion displays presented in sequence and then to report the motion directions for each. Remembered motion directions were shifted away from the actual motion directions, an effect similar to the motion repulsion observed during perception. More important, the item retrieved second showed greater repulsion than the item retrieved first. This suggests that earlier retrieval exerted greater inhibition on the other item being held in short-term memory. This retrieval-induced motion repulsion could be explained neither by reduced cognitive resources for maintaining short-term memory nor by continued inhibition between short-term memory representations. These results indicate that retrieval of memory representations inhibits other representations in short-term memory. We discuss mechanisms of retrieval-induced inhibition and their implications for the structure of memory. © The Author(s) 2015.

  7. Inhibition of HERG potassium channels by celecoxib and its mechanism.

    Directory of Open Access Journals (Sweden)

    Roman V Frolov

    Full Text Available Celecoxib (Celebrex, a widely prescribed selective inhibitor of cyclooxygenase-2, can modulate ion channels independently of cyclooxygenase inhibition. Clinically relevant concentrations of celecoxib can affect ionic currents and alter functioning of neurons and myocytes. In particular, inhibition of Kv2.1 channels by celecoxib leads to arrhythmic beating of Drosophila heart and of rat heart cells in culture. However, the spectrum of ion channels involved in human cardiac excitability differs from that in animal models, including mammalian models, making it difficult to evaluate the relevance of these observations to humans. Our aim was to examine the effects of celecoxib on hERG and other human channels critically involved in regulating human cardiac rhythm, and to explore the mechanisms of any observed effect on the hERG channels.Celecoxib inhibited the hERG, SCN5A, KCNQ1 and KCNQ1/MinK channels expressed in HEK-293 cells with IC(50s of 6.0 µM, 7.5 µM, 3.5 µM and 3.7 µM respectively, and the KCND3/KChiP2 channels expressed in CHO cells with an IC(50 of 10.6 µM. Analysis of celecoxib's effects on hERG channels suggested gating modification as the mechanism of drug action.The above channels play a significant role in drug-induced long QT syndrome (LQTS and short QT syndrome (SQTS. Regulatory guidelines require that all new drugs under development be tested for effects on the hERG channel prior to first administration in humans. Our observations raise the question of celecoxib's potential to induce cardiac arrhythmias or other channel related adverse effects, and make a case for examining such possibilities.

  8. Induced-fit Mechanism for Prolyl Endopeptidase

    Energy Technology Data Exchange (ETDEWEB)

    Li, Min; Chen, Changqing; Davies, David R.; Chiu, Thang K. (NIH); (LSU); (Chinese Aca. Sci.)

    2010-11-15

    Prolyl peptidases cleave proteins at proline residues and are of importance for cancer, neurological function, and type II diabetes. Prolyl endopeptidase (PEP) cleaves neuropeptides and is a drug target for neuropsychiatric diseases such as post-traumatic stress disorder, depression, and schizophrenia. Previous structural analyses showing little differences between native and substrate-bound structures have suggested a lock-and-key catalytic mechanism. We now directly demonstrate from seven structures of Aeromonus punctata PEP that the mechanism is instead induced fit: the native enzyme exists in a conformationally flexible opened state with a large interdomain opening between the {beta}-propeller and {alpha}/{beta}-hydrolase domains; addition of substrate to preformed native crystals induces a large scale conformational change into a closed state with induced-fit adjustments of the active site, and inhibition of this conformational change prevents substrate binding. Absolute sequence conservation among 28 orthologs of residues at the active site and critical residues at the interdomain interface indicates that this mechanism is conserved in all PEPs. This finding has immediate implications for the use of conformationally targeted drug design to improve specificity of inhibition against this family of proline-specific serine proteases.

  9. Curcumin-induced histone acetylation inhibition improves stress-induced gastric ulcer disease in rats.

    Science.gov (United States)

    He, Ping; Zhou, Renmin; Hu, Guorui; Liu, Zhifeng; Jin, Yu; Yang, Guang; Li, Mei; Lin, Qian

    2015-03-01

    Curcumin is known to possess anti‑inflammatory properties. Despite the fact that curcumin is known to be a strong inhibitor of H+, K+‑ATPase activity, the mechanism underlying the curcumin‑induced inhibition of the transcription of the H+, K+‑ATPase α subunit in gastric mucosal parietal cells remains unclear. The present study investigated the possible mechanism by which curcumin inhibits stomach H+, K+‑ATPase activity during the acute phase of gastric ulcer disease. A rat model of stress‑induced gastric ulcers was produced, in which the anti‑ulcer effects of curcumin were examined. Curcumin‑induced inhibition of the H+, K+‑ATPase promoter via histone acetylation, was verified using a chromatin immunoprecipitation assay. The results showed that curcumin improved stress‑induced gastric ulcer disease in rats, as demonstrated by increased pH values and reduced gastric mucosal hemorrhage and ulcer index. These effects were accompanied by a significant reduction in the level of histone H3 acetylation at the site of the H+, K+‑ATPase promoter and in the expression of the gastric H+,K+‑ATPase α subunit gene and protein. In conclusion, curcumin downregulated the acetylation of histone H3 at the site of the H+, K+‑ATPase promoter gene, thereby inhibiting the transcription and expression of the H+, K+‑ATPase gene. Curcumin was shown to have a preventive and therapeutic effect in gastric ulcer disease.

  10. ERK inhibition enhances TSA-induced gastric cancer cell apoptosis via NF-κB-dependent and Notch-independent mechanism.

    Science.gov (United States)

    Yao, Jun; Qian, Cui-Juan; Ye, Bei; Zhang, Xin; Liang, Yong

    2012-09-04

    To analyze the combined impact of the histone deacetylase inhibitor (HDACI) Trichostatin A (TSA) and the extracellular-signal-regulated kinase 1/2 (ERK1/2) inhibitor PD98059 on gastric cancer (GC) cell line SGC7901 growth. SGC7901 cells were treated with TSA, PD98059 or with a TSA-PD98059 combination. Effects of drug treatment on tumor cell proliferation, apoptosis, cell cycle progression, and cell signaling pathways were investigated by MTS assay, flow cytometry, Western blotting, chromatin immunoprecipitation (ChIP) assay, electrophoretic mobility shift assay (EMSA), and luciferase reporter assay, respectively. PD98059 enhanced TSA-induced cell growth arrest, apoptosis and activation of p21(WAF1/CIP1), but reversed TSA-induced activation of ERK1/2 and nuclear factor-κB (NF-κB). TSA alone up-regulated Notch1 and Hes1, and down-regulated Notch2, but PD98059 did not affect the trends of Notch1 and Notch2 induced by TSA. Particularly, PD98059 did potentiate the ability of TSA to down-regulate phospho-histone H3 protein, but increased levels of the acetylated forms of histone H3 bound to the p21(WAF1/CIP1) promoter, leading to enhanced expression of p21(WAF1/CIP1) in SGC7901 cells. PD98059 synergistically potentiates TSA-induced GC growth arrest and apoptosis by manipulating NF-κB and p21(WAF1/CIP1) independent of Notch. Therefore, concomitant administration of HDACIs and ERK1/2 inhibitors may be a promising treatment strategy for individuals with GC. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Inhibition of chrysin on xanthine oxidase activity and its inhibition mechanism.

    Science.gov (United States)

    Lin, Suyun; Zhang, Guowen; Liao, Yijing; Pan, Junhui

    2015-11-01

    Chrysin, a bioactive flavonoid, was investigated for its potential to inhibit the activity of xanthine oxidase (XO), a key enzyme catalyzing xanthine to uric acid and finally causing gout. The kinetic analysis showed that chrysin possessed a strong inhibition on XO ability in a reversible competitive manner with IC50 value of (1.26±0.04)×10(-6)molL(-1). The results of fluorescence titrations indicated that chrysin bound to XO with high affinity, and the interaction was predominately driven by hydrogen bonds and van der Waals forces. Analysis of circular dichroism demonstrated that chrysin induced the conformational change of XO with increases in α-helix and β-sheet and reductions in β-turn and random coil structures. Molecular simulation revealed that chrysin interacted with the amino acid residues Leu648, Phe649, Glu802, Leu873, Ser876, Glu879, Arg880, Phe1009, Thr1010, Val1011 and Phe1013 located within the active cavity of XO. The mechanism of chrysin on XO activity may be the insertion of chrysin into the active site occupying the catalytic center of XO to avoid the entrance of xanthine and causing conformational changes in XO. Furthermore, the interaction assays indicated that chrysin and its structural analog apigenin exhibited an additive effect on inhibition of XO. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Inhibition of di(2-ethylhexyl) phthalate (DEHP)-induced endocrine disruption by co-treatment of vitamins C and E and their mechanism of action.

    Science.gov (United States)

    Choi, Seul Min; Lim, Duck Soo; Kim, Min Kook; Yoon, Sungpil; Kacew, Sam; Kim, Hyung Sik; Lee, Byung-Mu

    2018-05-29

    The endocrine disrupting actions of di(2-ethylhexyl) phthalate (DEHP) on testicular functions are postulated to involve excess free radical generation. Thus the aim of this study was to examine the ability of antioxidant vitamins C and E to prevent DEHP-induced testicular disruption in male Sprague-Dawley (SD) rats. SD male rats were administered DEHP alone or DEHP with vitamin C and/or vitamin E for 30 days. DEHP alone increased the levels of testosterone (T) and reduced estradiol (E 2 ) concentrations. Supplementation with antioxidant vitamins diminished or restored serum T levels noted in DEHP-treated rats to control values. In contrast vitamins C and E increased E 2 levels to control in rats administered DEHP. Antioxidants significantly improved the decreased testicular levels of reduced glutathione and activity of superoxide dismutase compared to DEHP-treatment alone. Co-treatment of vitamins C and E also markedly improved the reduced epididymal sperm head counts and elevated levels of malondialdehyde (MDA) or 8-hydroxydeoxyguanosine (8-OHdG) induced by DEHP treatment. These results support the concept that the adverse actions of DEHP may be related to increased free radical generation while co-treatment with vitamins C and E significantly blocked the actions of DEHP on male testicular functions.

  13. Glucocorticoids and inhibition of bone formation induced by skeletal unloading

    International Nuclear Information System (INIS)

    Halloran, B.P.; Bikle, D.D.; Cone, C.M.; Morey-Holton, E.

    1988-01-01

    Skeletal unloading or loss of normal weight bearing in the growing animal inhibits bone formation and reduces bone calcium. To determine whether the inhibition of bone formation induced by skeletal unloading is a consequence of an increase in plasma glucocorticoids and/or an increase in bone sensitivity to glucocorticoids, the authors measured plasma corticosterone throughout the day in unloaded and normally loaded rats (hindlimb elevation model) and examined the effect of adrenalectomy on the response of bone to skeletal unloading. Plasma corticosterone levels were similar in normally loaded and unloaded rats at all times. Skeletal unloading in sham-adrenalectomized animals reduced tibial and vertebral calcium by 11.5 and 11.1%, respectively, and in adrenalectomized animals by 15.3 and 20.3%, respectively. Uptake of 45 Ca and [ 3 H]proline in the tibia was reduced by 8 and 14%, respectively, in the sham-adrenalectomized animals and by 13 and 19% in the adrenalectomized animals. Bone formation and apposition rates were reduced to the same level in sham- and adrenalectomized animals. These results suggest that the inhibition of bone formation induced by skeletal unloading is not a consequence of increased plasma glucocorticoids or an increase in bone sensitivity to the glucocorticoids but, rather, point to a local mediator in bone that senses mechanical load and transmits that information to the bone-forming cells directly

  14. Heat shock protein 70 inhibits shrinkage-induced programmed cell death via mechanisms independent of effects on cell volume-regulatory membrane transport proteins

    DEFF Research Database (Denmark)

    Nylandsted, J; Jäättelä, M; Hoffmann, E K

    2004-01-01

    Cell shrinkage is a ubiquitous feature of programmed cell death (PCD), but whether it is an obligatory signalling event in PCD is unclear. Heat shock protein 70 (Hsp70) potently counteracts PCD in many cells, by mechanisms that are incompletely understood. In the present investigation, we found...... that severe hypertonic stress greatly diminished the viability of murine fibrosarcoma cells (WEHI-902) and immortalized murine embryonic fibroblasts (iMEFs). This effect was attenuated markedly by Hsp70 over-expression. To determine whether the protective effect of Hsp70 was mediated via an effect on volume...... regulatory ion transport, we compared regulatory volume decrease (RVD) and increase (RVI) in control WEHI-902 cells and after increasing Hsp70 levels by heat shock or over-expression (WEHI-912). Hsp70 levels affected neither RVD, RVI nor the relative contributions of the Na(+)/H(+)-exchanger (NHE1) and Na...

  15. Molecular mechanisms of DNA repair inhibition by caffeine

    Energy Technology Data Exchange (ETDEWEB)

    Selby, C.P.; Sancar, A. (Univ. of North Carolina School of Medicine, Chapel Hill (USA))

    1990-05-01

    Caffeine potentiates the mutagenic and lethal effects of genotoxic agents. It is thought that this is due, at least in some organisms, to inhibition of DNA repair. However, direct evidence for inhibition of repair enzymes has been lacking. Using purified Escherichia coli DNA photolyase and (A)BC excinuclease, we show that the drug inhibits photoreactivation and nucleotide excision repair by two different mechanisms. Caffeine inhibits photoreactivation by interfering with the specific binding of photolyase to damaged DNA, and it inhibits nucleotide excision repair by promoting nonspecific binding of the damage-recognition subunit, UvrA, of (A)BC excinuclease. A number of other intercalators, including acriflavin and ethidium bromide, appear to inhibit the excinuclease by a similar mechanism--that is, by trapping the UvrA subunit in nonproductive complexes on undamaged DNA.

  16. Mechanisms of herb-induced nephrotoxicity.

    Science.gov (United States)

    Allard, T; Wenner, T; Greten, H J; Efferth, T

    2013-01-01

    Herbal therapies gained much popularity among the general public, but compared to therapies approved by official authorities, toxicological studies are frequently not available for them. Hence, there may be inherent risks and the kidneys may be especially vulnerable to toxic effects. Herbs may induce nephrotoxicity by induction of apoptosis. High oxalate contents in Star fruit (Averrhoa carambola L.) may induce acute nephropathy. Triptolide from Thunder God Vine (Triperygium wilfordii Hook) is a diterpenoid epoxide with induces reactive oxygen species and nephrotubular apoptosis. Cranberry juice is discussed as promoter of kidney stone formation (nephrolithiasis). Abuse of guaifenesin from Roughbark (Guaicum officinale L.) increases stone formation. Aristolochia acids from Aristolochia fangchi Y.C.Wu ex L.D. Chow & S.M. Hwang causes the well-known aristolochic acid nephropathy and carcinogenesis by DNA adduct formation. Carboxyatractyloside from Impila (Callilepsis laureola DC.) inhibits mitochondrial ATP synthesis. Acute allergic interstitial nephritis was diagnosed after intake of Peruvian Cat's claw (Uncaria tomentosa Willd. DC.). Whether or not Willow Bark (Salix alba L.) induces analgesic nephropathwy is a matter of discussion. Other herbal therapies are considered to affect the rennin-angiotensisn-aldosterone (RAA) system Ephedra sinica Stapf with its ingredient ephedrine. Devil's Claw (Harpagophytum procumbens DC. Ex Meisn.) and licorice (Glycyrrhiza glabra L.) may inhibit major renal transport processes needed for filtration, secretion, and absorption. Strategies to minimize nephrotoxicity include (1) quality control and standardization of herbal products, (2) research on the molecular modes of action to better understand pathophysiological mechanisms of herbal products as well as (3) clinical trials to demonstrate efficacy and safety.

  17. The role of somatostatin in GLP-1-induced inhibition of glucagon secretion in mice

    DEFF Research Database (Denmark)

    Ørgaard, Anne; Holst, Jens J

    2017-01-01

    AIMS/HYPOTHESIS: Glucagon-like peptide-1 (GLP-1) receptor agonists are currently used for the treatment of type 2 diabetes. Their main mechanism of action is enhancement of glucose-induced insulin secretion (from increased beta cell glucose sensitivity) and inhibition of glucagon secretion...... on glucagon secretion is heavily debated. Glucagon inhibition is also said to be glucose-dependent, although it is unclear what is meant by this. We hypothesise here that GLP-1 does not inhibit glucagon secretion during hypoglycaemia because the inhibition depends on somatostatin secretion, which in turn...

  18. Trichilia monadelpha Bark Extracts Inhibit Carrageenan-Induced ...

    African Journals Online (AJOL)

    The present study was undertaken to evaluate the anti-inflammatory properties of aqueous (TWE), alcoholic (TAE) and petroleum ether extract (TPEE) of T. ... The reference anti-inflammatory drugs (diclofenac and dexamethasone) inhibited the chick-carrageenan-induced footpad oedema, with maximal inhibitions of ...

  19. Histone deacetylase inhibition abolishes stress-induced spatial memory impairment.

    Science.gov (United States)

    Vargas-López, Viviana; Lamprea, Marisol R; Múnera, Alejandro

    2016-10-01

    Acute stress induced before spatial training impairs memory consolidation. Although non-epigenetic underpinning of such effect has been described, the epigenetic mechanisms involved have not yet been studied. Since spatial training and intense stress have opposite effects on histone acetylation balance, it is conceivable that disruption of such balance may underlie acute stress-induced spatial memory consolidation impairment and that inhibiting histone deacetylases prevents such effect. Trichostatin-A (TSA, a histone deacetylase inhibitor) was used to test its effectiveness in preventing stress' deleterious effect on memory. Male Wistar rats were trained in a spatial task in the Barnes maze; 1-h movement restraint was applied to half of them before training. Immediately after training, stressed and non-stressed animals were randomly assigned to receive either TSA (1mg/kg) or vehicle intraperitoneal injection. Twenty-four hours after training, long-term spatial memory was tested; plasma and brain tissue were collected immediately after the memory test to evaluate corticosterone levels and histone H3 acetylation in several brain areas. Stressed animals receiving vehicle displayed memory impairment, increased plasma corticosterone levels and markedly reduced histone H3 acetylation in prelimbic cortex and hippocampus. Such effects did not occur in stressed animals treated with TSA. The aforementioned results support the hypothesis that acute stress induced-memory impairment is related to histone deacetylation. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Mesenchymal stem cells inhibit lymphocyte proliferation by mitogens and alloantigens by different mechanisms

    International Nuclear Information System (INIS)

    Rasmusson, Ida; Ringden, Olle; Sundberg, Berit; Le Blanc, Katarina

    2005-01-01

    Human mesenchymal stem cells (MSCs) have immuno-modulatory properties. They inhibit T-cell proliferation to mitogens and alloantigens in vitro and prolong skin graft survival in vivo. We found that MSCs inhibited the proliferation of peripheral blood lymphocytes (PBLs) to phorbol myristate acetate (PMA), suggesting that MSCs exert an inhibitory effect downstream of the receptor level. We analyzed cytokine profiles of PBLs co-cultured with MSCs. MSCs increased interleukin (IL)-2 and soluble IL-2 receptor in mixed lymphocyte cultures (MLCs), while IL-2 and IL-2R decreased in phytohemagglutinin (PHA)-stimulated PBL cultures. MSCs inhibited IL-2 induced proliferation, without absorbing IL-2. IL-10 levels increased in MLCs co-cultured with 10% MSCs, while the levels were not affected in PHA cultures. In MLCs inhibited by MSCs, antibodies against IL-10 further suppressed proliferation but had no effect in PHA cultures. Addition of indomethacin, an inhibitor of prostaglandin-synthesis, restored part of the inhibition by MSCs in PHA cultures. However, indomethacin did not affect MSC-induced inhibition in MLCs. To conclude, our data indicate that MSC-induced suppression is a complex mechanism affecting IL-2 and IL-10 signaling and may function differently, depending on T-cell stimuli. Prostaglandins are important in the inhibition by MSCs when the T cells were activated by PHA, but not alloantigens

  1. Molecular Mechanisms of Induced Pluripotency

    Science.gov (United States)

    Muchkaeva, I.A.; Dashinimaev, E.B.; Terskikh, V.V.; Sukhanov, Y.V.; Vasiliev, A.V.

    2012-01-01

    In this review the distinct aspects of somatic cell reprogramming are discussed. The molecular mechanisms of generation of induced pluripotent stem (iPS) cells from somatic cells via the introduction of transcription factors into adult somatic cells are considered. Particular attention is focused on the generation of iPS cells without genome modifications via the introduction of the mRNA of transcription factors or the use of small molecules. Furthermore, the strategy of direct reprogramming of somatic cells omitting the generation of iPS cells is considered. The data concerning the differences between ES and iPS cells and the problem of epigenetic memory are also discussed. In conclusion, the possibility of using iPS cells in regenerative medicine is considered. PMID:22708059

  2. The PDE4 inhibitor CHF-6001 and LAMAs inhibit bronchoconstriction-induced remodeling in lung slices.

    Science.gov (United States)

    Kistemaker, Loes E M; Oenema, Tjitske A; Baarsma, Hoeke A; Bos, I Sophie T; Schmidt, Martina; Facchinetti, Fabrizio; Civelli, Maurizio; Villetti, Gino; Gosens, Reinoud

    2017-09-01

    Combination therapy of PDE4 inhibitors and anticholinergics induces bronchoprotection in COPD. Mechanical forces that arise during bronchoconstriction may contribute to airway remodeling. Therefore, we investigated the impact of PDE4 inhibitors and anticholinergics on bronchoconstriction-induced remodeling. Because of the different mechanism of action of PDE4 inhibitors and anticholinergics, we hypothesized functional interactions of these two drug classes. Guinea pig precision-cut lung slices were preincubated with the PDE4 inhibitors CHF-6001 or roflumilast and/or the anticholinergics tiotropium or glycopyorrolate, followed by stimulation with methacholine (10 μM) or TGF-β 1 (2 ng/ml) for 48 h. The inhibitory effects on airway smooth muscle remodeling, airway contraction, and TGF-β release were investigated. Methacholine-induced protein expression of smooth muscle-myosin was fully inhibited by CHF-6001 (0.3-100 nM), whereas roflumilast (1 µM) had smaller effects. Tiotropium and glycopyrrolate fully inhibited methacholine-induced airway remodeling (0.1-30 nM). The combination of CHF-6001 and tiotropium or glycopyrrolate, in concentrations partially effective by themselves, fully inhibited methacholine-induced remodeling in combination. CHF-6001 did not affect airway closure and had limited effects on TGF-β 1 -induced remodeling, but rather, it inhibited methacholine-induced TGF-β release. The PDE4 inhibitor CHF-6001, and to a lesser extent roflumilast, and the LAMAs tiotropium and glycopyrrolate inhibit bronchoconstriction-induced remodeling. The combination of CHF-6001 and anticholinergics was more effective than the individual compounds. This cooperativity might be explained by the distinct mechanisms of action inhibiting TGF-β release and bronchoconstriction. Copyright © 2017 the American Physiological Society.

  3. Gliclazide directly inhibits arginine-induced glucagon release

    DEFF Research Database (Denmark)

    Cejvan, Kenan; Coy, David H; Holst, Jens Juul

    2002-01-01

    Arginine-stimulated insulin and somatostatin release is enhanced by the sulfonylurea gliclazide. In contrast, gliclazide inhibits the glucagon response. The aim of the present study was to investigate whether this inhibition of glucagon release was mediated by a direct suppressive effect of glicl......Arginine-stimulated insulin and somatostatin release is enhanced by the sulfonylurea gliclazide. In contrast, gliclazide inhibits the glucagon response. The aim of the present study was to investigate whether this inhibition of glucagon release was mediated by a direct suppressive effect....... In islet perifusions with DC-41-33, arginine-induced glucagon release was inhibited by 66%. We therefore concluded that gliclazide inhibits glucagon release by a direct action on the pancreatic A cell....

  4. Inhibition of Lipopolysaccharide-Induced Neuroinflammatory Events ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research October 2014; 13 (10): 1615-1620. ISSN: 1596-5996 ... LPS-induced excessive production of inflammatory mediator such as iNOS was also ... several studies have reported antioxidant, antiallergic ...

  5. Ketose induced respiratory inhibition in isolated hepatocytes.

    Science.gov (United States)

    Martínez, P; Carrascosa, J M; Núñez de Castro, I

    1987-06-01

    The addition of 10 mM fructose or 10 mM tagatose to a suspension of hepatocytes caused respiratory inhibition, whereas no change in oxygen uptake was observed following the addition of glucose. However, incubations in the presence of fructose showed a high, aerobic glycolytic activity. Tagatose is phosphorylated to tagatose 1-phosphate but is not further metabolized by cell free liver extract. Moreover, the addition of fructose to glucagon treated cells also caused the Crabtree-like effect. The concentration of adenine nucleotides and inorganic phosphate (Pi) in the mitochondrial and cytosolic compartments during incubation (time 30 min) was determined by the digitonin fractionation procedure. In the presence of 10 mM fructose or tagatose, the total adenine nucleotide pools decreased by 40%; however, glucose produced no change. The addition of ketoses diminished the asymmetric distribution of extramitochondrial (ATP/ADP)e ratio and intramitochondrial (ATP/ADP)i ratio. At the same time the total mitochondrial Pi fell from 17 mM to 6-7 mM. The mitochondrial membrane potential (-161 mV) in the presence of fructose showed no changes during the 30 min experimental period. An increase in the NADH/NAD+ ratio was observed. These results suggest that in hepatocytes the inhibition of respiration is not necessarily linked with the enhanced aerobic glycolysis, by competition for common substrates.

  6. Aspirin augments hyaluronidase induced adhesion inhibition ...

    African Journals Online (AJOL)

    Postoperative adhesions occur after virtually all abdomino-pelvic surgery and are the leading cause of intestinal obstruction and other gynaecologic problems. We used an animal model to test the efficacy of combined administration of aspirin and hyaluronidase on adhesion formation. Adhesions were induced using ...

  7. Two mechanisms of oral malodor inhibition by zinc ions.

    Science.gov (United States)

    Suzuki, Nao; Nakano, Yoshio; Watanabe, Takeshi; Yoneda, Masahiro; Hirofuji, Takao; Hanioka, Takashi

    2018-01-18

    The aim of this study was to reveal the mechanisms by which zinc ions inhibit oral malodor. The direct binding of zinc ions to gaseous hydrogen sulfide (H2S) was assessed in comparison with other metal ions. Nine metal chlorides and six metal acetates were examined. To understand the strength of H2S volatilization inhibition, the minimum concentration needed to inhibit H2S volatilization was determined using serial dilution methods. Subsequently, the inhibitory activities of zinc ions on the growth of six oral bacterial strains related to volatile sulfur compound (VSC) production and three strains not related to VSC production were evaluated. Aqueous solutions of ZnCl2, CdCl2, CuCl2, (CH3COO)2Zn, (CH3COO)2Cd, (CH3COO)2Cu, and CH3COOAg inhibited H2S volatilization almost entirely. The strengths of H2S volatilization inhibition were in the order Ag+ > Cd2+ > Cu2+ > Zn2+. The effect of zinc ions on the growth of oral bacteria was strain-dependent. Fusobacterium nucleatum ATCC 25586 was the most sensitive, as it was suppressed by medium containing 0.001% zinc ions. Zinc ions have an inhibitory effect on oral malodor involving the two mechanisms of direct binding with gaseous H2S and suppressing the growth of VSC-producing oral bacteria.

  8. Aspirin Inhibits Platelet-Derived Sphingosine-1-Phosphate Induced Endothelial Cell Migration.

    Science.gov (United States)

    Polzin, Amin; Knoop, Betül; Böhm, Andreas; Dannenberg, Lisa; Zurek, Mark; Zeus, Tobias; Kelm, Malte; Levkau, Bodo; Rauch, Bernhard H

    2018-01-01

    Aspirin plays a crucial role in the prevention of cardiovascular diseases. We previously described that aspirin has effects beyond inhibition of platelet aggregation, as it inhibited thrombin-mediated release of sphingosine-1-phosphate (S1P) from human platelets. S1P is a bioactive lipid with important functions on inflammation and apoptosis. In endothelial cells (EC), S1P is a key regulator of cell migration. In this study, we aimed to analyze the effects of aspirin on platelet-induced EC migration. Human umbilical EC migration was measured by Boyden chamber assay. EC migration was induced by platelet supernatants of thrombin receptor-activating peptide-1 (AP1) stimulated platelets. To investigate the S1P receptor subtype that promotes EC migration, specific inhibitors of S1P receptor subtypes were applied. S1P induced EC migration in a concentration-dependent manner. EC migration induced by AP1-stimulated platelet supernatants was reduced by aspirin. S1P1 receptor inhibition almost completely abolished EC migration induced by activated platelets. The inhibition of S1P2 or S1P3 receptor had no effect. Aspirin inhibits EC migration induced by activated platelets that is in part due to S1P and mediated by the endothelial S1P1 receptor. The clinical significance of this novel mechanism of aspirin action has to be investigated in future studies. © 2017 S. Karger AG, Basel.

  9. Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles

    Energy Technology Data Exchange (ETDEWEB)

    Hannon, Patrick R., E-mail: phannon2@illinois.edu; Brannick, Katherine E., E-mail: kbran@illinois.edu; Wang, Wei, E-mail: Wei.Wang2@covance.com; Gupta, Rupesh K., E-mail: drrupesh@yahoo.com; Flaws, Jodi A., E-mail: jflaws@illinois.edu

    2015-04-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehicle control or DEHP (1–100 μg/ml) for 24–96 h to establish the temporal effects of DEHP on the follicle. Following 24–96 h of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydroxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. - Highlights: • DEHP inhibits antral follicle growth by dysregulating cell cycle regulators. • DEHP induces antral follicle atresia by dysregulating apoptosis regulators. • DEHP

  10. Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles

    International Nuclear Information System (INIS)

    Hannon, Patrick R.; Brannick, Katherine E.; Wang, Wei; Gupta, Rupesh K.; Flaws, Jodi A.

    2015-01-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehicle control or DEHP (1–100 μg/ml) for 24–96 h to establish the temporal effects of DEHP on the follicle. Following 24–96 h of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydroxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. - Highlights: • DEHP inhibits antral follicle growth by dysregulating cell cycle regulators. • DEHP induces antral follicle atresia by dysregulating apoptosis regulators. • DEHP

  11. Mercuric ions inhibit mitogen-activated protein kinase dephosphorylation by inducing reactive oxygen species

    International Nuclear Information System (INIS)

    Haase, Hajo; Engelhardt, Gabriela; Hebel, Silke; Rink, Lothar

    2011-01-01

    Mercury intoxication profoundly affects the immune system, in particular, signal transduction of immune cells. However, the mechanism of the interaction of mercury with cellular signaling pathways, such as mitogen activated protein kinases (MAPK), remains elusive. Therefore, the objective of this study is to investigate three potential ways in which Hg 2+ ions could inhibit MAPK dephosphorylation in the human T-cell line Jurkat: (1) by direct binding to phosphatases; (2) by releasing cellular zinc (Zn 2+ ); and (3) by inducing reactive oxygen species (ROS). Hg 2+ causes production of ROS, measured by dihydrorhodamine 123, and triggers ROS-mediated Zn 2+ release, detected with FluoZin-3. Yet, phosphatase-inhibition is not mediated by binding of Zn 2+ or Hg 2+ . Rather, phosphatases are inactivated by at least two forms of thiol oxidation; initial inhibition is reversible with reducing agents such as Tris(2-carboxyethyl)phosphine. Prolonged inhibition leads to non-reversible phosphatase oxidation, presumably oxidizing the cysteine thiol to sulfinic- or sulfonic acid. Notably, phosphatases are a particularly sensitive target for Hg 2+ -induced oxidation, because phosphatase activity is inhibited at concentrations of Hg 2+ that have only minor impact on over all thiol oxidation. This phosphatase inhibition results in augmented, ROS-dependent MAPK phosphorylation. MAPK are important regulators of T-cell function, and MAPK-activation by inhibition of phosphatases seems to be one of the molecular mechanisms by which mercury affects the immune system.

  12. Naftopidil inhibits 5-hydroxytryptamine-induced bladder contraction in rats.

    Science.gov (United States)

    Sakai, Takumi; Kasahara, Ken-ichi; Tomita, Ken-ichi; Ikegaki, Ichiro; Kuriyama, Hiroshi

    2013-01-30

    Naftopidil is an α(1D) and α(1A) subtype-selective α(1)-adrenoceptor antagonist that has been used to treat lower urinary tract symptoms of benign prostatic hyperplasia. In this study, we investigated the effects of naftopidil on 5-hydroxytryptamine (5-HT)-induced rat bladder contraction (10(-8)-10(-4) M). Naftopidil (0.3, 1, and 3 μM) inhibited 5-HT-induced bladder contraction in a concentration-dependent manner. On the other hand, other α(1)-adrenoceptor antagonists, tamsulosin, silodosin or prazosin, did not inhibit 5-HT-induced bladder contraction. The 5-HT-induced bladder contraction was inhibited by both ketanserin and 4-(4-fluoronaphthalen-1-yl)-6-propan-2-ylpyrimidin-2-amine (RS127445), serotonin 5-HT(2A) and 5-HT(2B) receptor antagonists, respectively. In addition, 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) and α-methyl-5-HT, 5-HT(2A) and 5-HT(2) receptor agonists, respectively, induced bladder contraction. The 5-HT-induced bladder contraction was not inhibited by N-[2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl]-N-pyridin-2-yl-cyclohexanecarboxamide (WAY-100635), [1-[2[(methylsulfonyl)amino]ethyl]-4-piperidinyl]methyl-1-methyl-1H-indole-3-carboxylate (GR113808) or (R)-3-[2-[2-(4-methylpiperidin-1-yl)ethyl]pyrrolidine-1-sulphonyl]phenol (SB269970), 5-HT(1A), 5-HT(4) and 5-HT(7) receptor antagonists, respectively. Naftopidil inhibited both the 5-HT(2A) and 5-HT(2) receptor agonists-induced bladder contractions. Naftopidil binds to the human 5-HT(2A) and 5-HT(2B) receptors with pKi values of 6.55 and 7.82, respectively. These results suggest that naftopidil inhibits 5-HT-induced bladder contraction via blockade of the 5-HT(2A) and 5-HT(2B) receptors in rats. Furthermore, 5-HT-induced bladder contraction was enhanced in bladder strips obtained from bladder outlet obstructed rats, with this contraction inhibited by naftopidil. The beneficial effects of naftopidil on storage symptoms such as urinary frequency and nocturia in patients with benign

  13. hERG trafficking inhibition in drug-induced lethal cardiac arrhythmia.

    Science.gov (United States)

    Nogawa, Hisashi; Kawai, Tomoyuki

    2014-10-15

    Acquired long QT syndrome induced by non-cardiovascular drugs can cause lethal cardiac arrhythmia called torsades de points and is a significant problem in drug development. The prolongation of QT interval and cardiac action potential duration are mainly due to reduced physiological function of the rapidly activating voltage-dependent potassium channels encoded by human ether-a-go-go-related gene (hERG). Structurally diverse groups of drugs are known to directly inhibit hERG channel conductance. Therefore, the ability of acute hERG inhibition is routinely assessed at the preclinical stages in pharmaceutical testing. Recent findings indicated that chronic treatment with various drugs not only inhibits hERG channels but also decreases hERG channel expression in the plasma membrane of cardiomyocytes, which has become another concern in safety pharmacology. The mechanisms involve the disruption of hERG trafficking to the surface membrane or the acceleration of hERG protein degradation. From this perspective, we present a brief overview of mechanisms of drug-induced trafficking inhibition and pathological regulation. Understanding of drug-induced hERG trafficking inhibition may provide new strategies for predicting drug-induced QT prolongation and lethal cardiac arrhythmia in pharmaceutical drug development. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Resveratrol induces autophagy by directly inhibiting mTOR through ATP competition

    Science.gov (United States)

    Park, Dohyun; Jeong, Heeyoon; Lee, Mi Nam; Koh, Ara; Kwon, Ohman; Yang, Yong Ryoul; Noh, Jungeun; Suh, Pann-Ghill; Park, Hwangseo; Ryu, Sung Ho

    2016-01-01

    Resveratrol (RSV) is a natural polyphenol that has a beneficial effect on health, and resveratrol-induced autophagy has been suggested to be a key process in mediating many beneficial effects of resveratrol, such as reduction of inflammation and induction of cancer cell death. Although various resveratrol targets have been suggested, the molecule that mediates resveratrol-induced autophagy remains unknown. Here, we demonstrate that resveratrol induces autophagy by directly inhibiting the mTOR-ULK1 pathway. We found that inhibition of mTOR activity and presence of ULK1 are required for autophagy induction by resveratrol. In line with this mTOR dependency, we found that resveratrol suppresses the viability of MCF7 cells but not of SW620 cells, which are mTOR inhibitor sensitive and insensitive cancer cells, respectively. We also found that resveratrol-induced cancer cell suppression occurred ULK1 dependently. For the mechanism of action of resveratrol on mTOR inhibition, we demonstrate that resveratrol directly inhibits mTOR. We found that resveratrol inhibits mTOR by docking onto the ATP-binding pocket of mTOR (i.e., it competes with ATP). We propose mTOR as a novel direct target of resveratrol, and inhibition of mTOR is necessary for autophagy induction. PMID:26902888

  15. Selective inhibition of prostaglandin E2 receptors EP2 and EP4 induces apoptosis of human endometriotic cells through suppression of ERK1/2, AKT, NFkappaB, and beta-catenin pathways and activation of intrinsic apoptotic mechanisms.

    Science.gov (United States)

    Banu, Sakhila K; Lee, JeHoon; Speights, V O; Starzinski-Powitz, Anna; Arosh, Joe A

    2009-08-01

    Endometriosis is a benign chronic gynecological disease of reproductive-age women characterized by the presence of functional endometrial tissues outside the uterine cavity. It is an estrogen-dependent disease. Current treatment modalities to inhibit biosynthesis and actions of estrogen compromise menstruation, pregnancy, and the reproductive health of women and fail to prevent reoccurrence of disease. There is a critical need to identify new specific signaling modules for non-estrogen-targeted therapies for endometriosis. In our previous study, we reported that selective inhibition of cyclooxygenase-2 prevented survival, migration, and invasion of human endometriotic epithelial and stromal cells, which was due to decreased prostaglandin E(2) (PGE(2)) production. In this study, we determined mechanisms through which PGE(2) promoted survival of human endometriotic cells. Results of the present study indicate that 1) PGE(2) promotes survival of human endometriotic cells through EP2 and EP4 receptors by activating ERK1/2, AKT, nuclear factor-kappaB, and beta-catenin signaling pathways; 2) selective inhibition of EP2 and EP4 suppresses these cell survival pathways and augments interactions between proapoptotic proteins (Bax and Bad) and antiapoptotic proteins (Bcl-2/Bcl-XL), facilitates the release of cytochrome c, and thus activates caspase-3/poly (ADP-ribose) polymerase-mediated intrinsic apoptotic pathways; and 3) these PGE(2) signaling components are more abundantly expressed in ectopic endometriosis tissues compared with eutopic endometrial tissues during the menstrual cycle in women. These novel findings may provide an important molecular framework for further evaluation of selective inhibition of EP2 and EP4 as potential therapy, including nonestrogen target, to expand the spectrum of currently available treatment options for endometriosis in women.

  16. Manganese (II) induces chemical hypoxia by inhibiting HIF-prolyl hydroxylase: Implication in manganese-induced pulmonary inflammation

    International Nuclear Information System (INIS)

    Han, Jeongoh; Lee, Jong-Suk; Choi, Daekyu; Lee, Youna; Hong, Sungchae; Choi, Jungyun; Han, Songyi; Ko, Yujin; Kim, Jung-Ae; Mi Kim, Young; Jung, Yunjin

    2009-01-01

    Manganese (II), a transition metal, causes pulmonary inflammation upon environmental or occupational inhalation in excess. We investigated a potential molecular mechanism underlying manganese-induced pulmonary inflammation. Manganese (II) delayed HIF-1α protein disappearance, which occurred by inhibiting HIF-prolyl hydroxylase (HPH), the key enzyme for HIF-1α hydroxylation and subsequent von Hippel-Lindau(VHL)-dependent HIF-1α degradation. HPH inhibition by manganese (II) was neutralized significantly by elevated dose of iron. Consistent with this, the induction of cellular HIF-1α protein by manganese (II) was abolished by pretreatment with iron. Manganese (II) induced the HIF-1 target gene involved in pulmonary inflammation, vascular endothelial growth factor (VEGF), in lung carcinoma cell lines. The induction of VEGF was dependent on HIF-1. Manganese-induced VEGF promoted tube formation of HUVEC. Taken together, these data suggest that HIF-1 may be a potential mediator of manganese-induced pulmonary inflammation

  17. Glycation inhibits trichloroacetic acid (TCA)-induced whey protein precipitation

    Science.gov (United States)

    Four different WPI saccharide conjugates were successfully prepared to test whether glycation could inhibit WPI precipitation induced by trichloroacetic acid (TCA). Conjugates molecular weights after glycation were analyzed with SDS-PAGE. No significant secondary structure change due to glycation wa...

  18. Jasmonic Acid Enhances Al-Induced Root Growth Inhibition.

    Science.gov (United States)

    Yang, Zhong-Bao; He, Chunmei; Ma, Yanqi; Herde, Marco; Ding, Zhaojun

    2017-02-01

    Phytohormones such as ethylene and auxin are involved in the regulation of the aluminum (Al)-induced root growth inhibition. Although jasmonate (JA) has been reported to play a crucial role in the regulation of root growth and development in response to environmental stresses through interplay with ethylene and auxin, its role in the regulation of root growth response to Al stress is not yet known. In an attempt to elucidate the role of JA, we found that exogenous application of JA enhanced the Al-induced root growth inhibition. Furthermore, phenotype analysis with mutants defective in either JA biosynthesis or signaling suggests that JA is involved in the regulation of Al-induced root growth inhibition. The expression of the JA receptor CORONATINE INSENSITIVE1 (COI1) and the key JA signaling regulator MYC2 was up-regulated in response to Al stress in the root tips. This process together with COI1-mediated Al-induced root growth inhibition under Al stress was controlled by ethylene but not auxin. Transcriptomic analysis revealed that many responsive genes under Al stress were regulated by JA signaling. The differential responsive of microtubule organization-related genes between the wild-type and coi1-2 mutant is consistent with the changed depolymerization of cortical microtubules in coi1 under Al stress. In addition, ALMT-mediated malate exudation and thus Al exclusion from roots in response to Al stress was also regulated by COI1-mediated JA signaling. Together, this study suggests that root growth inhibition is regulated by COI1-mediated JA signaling independent from auxin signaling and provides novel insights into the phytohormone-mediated root growth inhibition in response to Al stress. © 2017 American Society of Plant Biologists. All Rights Reserved.

  19. Peripheral afferent mechanisms underlying acupuncture inhibition of cocaine behavioral effects in rats.

    Directory of Open Access Journals (Sweden)

    Seol Ah Kim

    Full Text Available Administration of cocaine increases locomotor activity by enhancing dopamine transmission. To explore the peripheral mechanisms underlying acupuncture treatment for drug addiction, we developed a novel mechanical acupuncture instrument (MAI for objective mechanical stimulation. The aim of this study was to evaluate whether acupuncture inhibition of cocaine-induced locomotor activity is mediated through specific peripheral nerves, the afferents from superficial or deep tissues, or specific groups of nerve fibers. Mechanical stimulation of acupuncture point HT7 with MAI suppressed cocaine-induced locomotor activity in a stimulus time-dependent manner, which was blocked by severing the ulnar nerve or by local anesthesia. Suppression of cocaine-induced locomotor activity was elicited after HT7 stimulation at frequencies of either 50 (for Meissner corpuscles or 200 (for Pacinian corpuscles Hz and was not affected by block of C/Aδ-fibers in the ulnar nerve with resiniferatoxin, nor generated by direct stimulation of C/Aδ-fiber afferents with capsaicin. These findings suggest that HT7 inhibition of cocaine-induced locomotor activity is mediated by A-fiber activation of ulnar nerve that originates in superficial and deep tissue.

  20. Quercetogetin protects against cigarette smoke extract-induced apoptosis in epithelial cells by inhibiting mitophagy.

    Science.gov (United States)

    Son, Eun Suk; Kim, Se-Hee; Ryter, Stefan W; Yeo, Eui-Ju; Kyung, Sun Young; Kim, Yu Jin; Jeong, Sung Hwan; Lee, Chang Soo; Park, Jeong-Woong

    2018-04-01

    Recent studies demonstrate that the autophagy-dependent turnover of mitochondria (mitophagy) mediates pulmonary epithelial cell death in response to cigarette smoke extract (CSE) exposure, and contributes to emphysema development in vivo during chronic cigarette smoke (CS)-exposure, although the underlying mechanisms remain unclear. Here, we investigated the role of mitophagy in regulating apoptosis in CSE-exposed human lung bronchial epithelial cells. Furthermore, we investigated the potential of the polymethoxylated flavone antioxidant quercetogetin (QUE) to inhibit CSE-induced mitophagy-dependent apoptosis. Our results demonstrate that CSE induces mitophagy in epithelial cells via mitochondrial dysfunction, and causes increased expression levels of the mitophagy-regulator protein PTEN-induced putative kinase-1 (PINK1) and the mitochondrial fission protein dynamin-1-like protein (DRP-1). CSE induced epithelial cell death and increased the expression of the apoptosis-related proteins cleaved caspase-3, -8 and -9. Caspase-3 activity was significantly increased in Beas-2B cells exposed to CSE, and decreased by siRNA-dependent knockdown of DRP-1. Treatment of epithelial cells with QUE inhibited CSE-induced mitochondrial dysfunction and mitophagy by inhibiting phospho (p)-DRP-1 and PINK1 expression. QUE suppressed mitophagy-dependent apoptosis by inhibiting the expression of cleaved caspase-3, -8 and -9 and downregulating caspase activity in human bronchial epithelial cells. These findings suggest that QUE may serve as a potential therapeutic in CS-induced pulmonary diseases. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Inhibition by acrolein of light-induced stomatal opening through inhibition of inward-rectifying potassium channels in Arabidopsis thaliana.

    Science.gov (United States)

    Islam, Md Moshiul; Ye, Wenxiu; Matsushima, Daiki; Khokon, Md Atiqur Rahman; Munemasa, Shintaro; Nakamura, Yoshimasa; Murata, Yoshiyuki

    2015-01-01

    Acrolein is a reactive α,β-unsaturated aldehyde derived from lipid peroxides, which are produced in plants under a variety of stress. We investigated effects of acrolein on light-induced stomatal opening using Arabidopsis thaliana. Acrolein inhibited light-induced stomatal opening in a dose-dependent manner. Acrolein at 100 μM inhibited plasma membrane inward-rectifying potassium (Kin) channels in guard cells. Acrolein at 100 μM inhibited Kin channel KAT1 expressed in a heterologous system using Xenopus leaves oocytes. These results suggest that acrolein inhibits light-induced stomatal opening through inhibition of Kin channels in guard cells.

  2. Autotaxin is induced by TSA through HDAC3 and HDAC7 inhibition and antagonizes the TSA-induced cell apoptosis.

    Science.gov (United States)

    Li, Song; Wang, Baolu; Xu, Yan; Zhang, Junjie

    2011-02-12

    Autotaxin (ATX) is a secreted glycoprotein with the lysophospholipase D (lysoPLD) activity to convert lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA), a bioactive lysophospholipid involved in diverse biological actions. ATX is highly expressed in some cancer cells and contributes to their tumorigenesis, invasion, and metastases, while in other cancer cells ATX is silenced or expressed at low level. The mechanism of ATX expression regulation in cancer cells remains largely unknown. In the present study, we demonstrated that trichostatin A (TSA), a well-known HDAC inhibitor (HDACi), significantly induced ATX expression in SW480 and several other cancer cells with low or undetectable endogenous ATX expression. ATX induction could be observed when HDAC3 and HDAC7 were down-regulated by their siRNAs. It was found that HDAC7 expression levels were low in the cancer cells with high endogenous ATX expression. Exogenous over-expression of HDAC7 inhibited ATX expression in these cells in a HDAC3-dependent manner. These data indicate that HDAC3 and HDAC7 collaboratively suppress ATX expression in cancer cells, and suggest that TSA induce ATX expression by inhibiting HDAC3 and HDAC7. The biological significance of this regulation mechanism was revealed by demonstrating that TSA-induced ATX protected cancer cells against TSA-induced apoptosis by producing LPA through its lysoPLD activity, which could be reversed by BrP-LPA and S32826, the inhibitors of the ATX-LPA axis. We have demonstrated that ATX expression is repressed by HDAC3 and HDAC7 in cancer cells. During TSA treatment, ATX is induced due to the HDAC3 and HDAC7 inhibition and functionally antagonizes the TSA-induced apoptosis. These results reveal an internal HDACi-resistant mechanism in cancer cells, and suggest that the inhibition of ATX-LPA axis would be helpful to improve the efficacy of HDACi-based therapeutics against cancer.

  3. Inhibition of autophagy induced by proteasome inhibition increases cell death in human SHG-44 glioma cells.

    Science.gov (United States)

    Ge, Peng-Fei; Zhang, Ji-Zhou; Wang, Xiao-Fei; Meng, Fan-Kai; Li, Wen-Chen; Luan, Yong-Xin; Ling, Feng; Luo, Yi-Nan

    2009-07-01

    The ubiquitin-proteasome system (UPS) and lysosome-dependent macroautophagy (autophagy) are two major intracellular pathways for protein degradation. Recent studies suggest that proteasome inhibitors may reduce tumor growth and activate autophagy. Due to the dual roles of autophagy in tumor cell survival and death, the effect of autophagy on the destiny of glioma cells remains unclear. In this study, we sought to investigate whether inhibition of the proteasome can induce autophagy and the effects of autophagy on the fate of human SHG-44 glioma cells. The proteasome inhibitor MG-132 was used to induce autophagy in SHG-44 glioma cells, and the effect of autophagy on the survival of SHG-44 glioma cells was investigated using an autophagy inhibitor 3-MA. Cell viability was measured by MTT assay. Apoptosis and cell cycle were detected by flow cytometry. The expression of autophagy related proteins was determined by Western blot. MG-132 inhibited cell proliferation, induced cell death and cell cycle arrest at G(2)/M phase, and activated autophagy in SHG-44 glioma cells. The expression of autophagy-related Beclin-1 and LC3-I was significantly up-regulated and part of LC3-I was converted into LC3-II. However, when SHG-44 glioma cells were co-treated with MG-132 and 3-MA, the cells became less viable, but cell death and cell numbers at G(2)/M phase increased. Moreover, the accumulation of acidic vesicular organelles was decreased, the expression of Beclin-1 and LC3 was significantly down-regulated and the conversion of LC3-II from LC3-I was also inhibited. Inhibition of the proteasome can induce autophagy in human SHG-44 glioma cells, and inhibition of autophagy increases cell death. This discovery may shed new light on the effect of autophagy on modulating the fate of SHG-44 glioma cells.Acta Pharmacologica Sinica (2009) 30: 1046-1052; doi: 10.1038/aps.2009.71.

  4. Mechanisms of inhibition of zinc-finger transcription factors by selenium compounds ebselen and selenite.

    Science.gov (United States)

    Larabee, Jason L; Hocker, James R; Hanas, Jay S

    2009-03-01

    The anti-inflammatory selenium compounds, ebselen (2-phenyl-1,2-benzisoselenazol-3[2H]-one) and selenite, were found to alter the DNA binding mechanisms and structures of cysteine-rich zinc-finger transcription factors. As assayed by DNase I protection, DNA binding by TFIIIA (transcription factor IIIA, prototypical Cys(2)His(2) zinc finger protein), was inhibited by micromolar amounts of ebselen. In a gel shift assay, ebselen inhibited the Cys(2)His(2) zinc finger-containing DNA binding domain (DBD) of the NF-kappaB mediated transcription factor Sp1. Ebselen also inhibited DNA binding by the p50 subunit of the pro-inflammatory Cys-containing NF-kappaB transcription factor. Electrospray ionization mass spectrometry (ESI-MS) was utilized to elucidate mechanisms of chemical interaction between ebselen and a zinc-bound Cys(2)His(2) zinc finger polypeptide modeled after the third finger of Sp1 (Sp1-3). Exposing Sp1-3 to micromolar amounts of ebselen resulted in Zn(2+) release from this peptide and the formation of a disulfide bond by oxidation of zinc finger SH groups, the likely mechanism for DNA binding inhibition. Selenite was shown by ESI-MS to also eject zinc from Sp1-3 as well as induce disulfide bond formation through SH oxidation. The selenite-dependent inhibition/oxidation mechanism differed from that of ebselen by inducing the formation of a stable selenotrisulfide bond. Selenite-induced selenotrisulfide formation was dependent upon the structure of the Cys(2)His(2) zinc finger as alteration in the finger structure enhanced this reaction as well as selenite-dependent zinc release. Ebselen and selenite-dependent inhibition/oxidation of Cys-rich zinc finger proteins, with concomitant release of zinc and finger structural changes, points to mechanisms at the atomic and protein level for selenium-induced alterations in Cys-rich proteins, and possible amelioration of certain inflammatory, neurodegenerative, and oncogenic responses.

  5. Oxygen-induced inhibition of silicon-on-insulator dewetting

    Energy Technology Data Exchange (ETDEWEB)

    Curiotto, S.; Leroy, F.; Cheynis, F.; Müller, P. [Aix Marseille Université, CNRS, CINaM UMR 7325, 13288 Marseille (France)

    2014-02-10

    We report that solid state dewetting of Si thin film on SiO{sub 2} can be reversibly inhibited by exposing the Si surface to a partial pressure of dioxygen (∼10{sup −7}Torr) at high temperature (∼1100K). Coupling in situ Low-Energy Electron Microscopy and ex situ atomic force microscopy we propose that the pinning of the contact line induced by the presence of small amounts of silicon oxide is the main physical process that inhibits the dewetting.

  6. Zinc blocks SOS-induced antibiotic resistance via inhibition of RecA in Escherichia coli.

    Science.gov (United States)

    Bunnell, Bryan E; Escobar, Jillian F; Bair, Kirsten L; Sutton, Mark D; Crane, John K

    2017-01-01

    Zinc inhibits the virulence of diarrheagenic E. coli by inducing the envelope stress response and inhibiting the SOS response. The SOS response is triggered by damage to bacterial DNA. In Shiga-toxigenic E. coli, the SOS response strongly induces the production of Shiga toxins (Stx) and of the bacteriophages that encode the Stx genes. In E. coli, induction of the SOS response is accompanied by a higher mutation rate, called the mutator response, caused by a shift to error-prone DNA polymerases when DNA damage is too severe to be repaired by canonical DNA polymerases. Since zinc inhibited the other aspects of the SOS response, we hypothesized that zinc would also inhibit the mutator response, also known as hypermutation. We explored various different experimental paradigms to induce hypermutation triggered by the SOS response, and found that hypermutation was induced not just by classical inducers such as mitomycin C and the quinolone antibiotics, but also by antiviral drugs such as zidovudine and anti-cancer drugs such as 5-fluorouracil, 6-mercaptopurine, and azacytidine. Zinc salts inhibited the SOS response and the hypermutator phenomenon in E. coli as well as in Klebsiella pneumoniae, and was more effective in inhibiting the SOS response than other metals. We then attempted to determine the mechanism by which zinc, applied externally in the medium, inhibits hypermutation. Our results show that zinc interferes with the actions of RecA, and protects LexA from RecA-mediated cleavage, an early step in initiation of the SOS response. The SOS response may play a role in the development of antibiotic resistance and the effect of zinc suggests ways to prevent it.

  7. Zinc blocks SOS-induced antibiotic resistance via inhibition of RecA in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Bryan E Bunnell

    Full Text Available Zinc inhibits the virulence of diarrheagenic E. coli by inducing the envelope stress response and inhibiting the SOS response. The SOS response is triggered by damage to bacterial DNA. In Shiga-toxigenic E. coli, the SOS response strongly induces the production of Shiga toxins (Stx and of the bacteriophages that encode the Stx genes. In E. coli, induction of the SOS response is accompanied by a higher mutation rate, called the mutator response, caused by a shift to error-prone DNA polymerases when DNA damage is too severe to be repaired by canonical DNA polymerases. Since zinc inhibited the other aspects of the SOS response, we hypothesized that zinc would also inhibit the mutator response, also known as hypermutation. We explored various different experimental paradigms to induce hypermutation triggered by the SOS response, and found that hypermutation was induced not just by classical inducers such as mitomycin C and the quinolone antibiotics, but also by antiviral drugs such as zidovudine and anti-cancer drugs such as 5-fluorouracil, 6-mercaptopurine, and azacytidine. Zinc salts inhibited the SOS response and the hypermutator phenomenon in E. coli as well as in Klebsiella pneumoniae, and was more effective in inhibiting the SOS response than other metals. We then attempted to determine the mechanism by which zinc, applied externally in the medium, inhibits hypermutation. Our results show that zinc interferes with the actions of RecA, and protects LexA from RecA-mediated cleavage, an early step in initiation of the SOS response. The SOS response may play a role in the development of antibiotic resistance and the effect of zinc suggests ways to prevent it.

  8. Equol inhibits growth, induces atresia, and inhibits steroidogenesis of mouse antral follicles in vitro

    International Nuclear Information System (INIS)

    Mahalingam, Sharada; Gao, Liying; Gonnering, Marni; Helferich, William; Flaws, Jodi A.

    2016-01-01

    Equol is a non-steroidal estrogen metabolite produced by microbial conversion of daidzein, a major soy isoflavone, in the gut of some humans and many animal species. Isoflavones and their metabolites can affect endogenous estradiol production, action, and metabolism, potentially influencing ovarian follicle function. However, no studies have examined the effects of equol on intact ovarian antral follicles, which are responsible for sex steroid synthesis and further development into ovulatory follicles. Thus, the present study tested the hypothesis that equol inhibits antral follicle growth, increases follicle atresia, and inhibits steroidogenesis in the adult mouse ovary. To test this hypothesis, antral follicles isolated from adult CD-1 mice were cultured with vehicle control (dimethyl sulfoxide; DMSO) or equol (600 nM, 6 μM, 36 μM, and 100 μM) for 48 and 96 h. Every 24 h, follicle diameters were measured to monitor growth. At 48 and 96 h, the culture medium was subjected to measurement of hormone levels, and the cultured follicles were subjected to gene expression analysis. Additionally, follicles were histologically evaluated for signs of atresia after 96 h of culture. The results indicate that equol (100 μM) inhibited follicle growth, altered the mRNA levels of bcl2-associated X protein and B cell leukemia/lymphoma 2, and induced follicle atresia. Further, equol decreased the levels of estradiol, testosterone, androstenedione, and progesterone, and it decreased mRNA levels of cholesterol side-chain cleavage, steroid 17-α-hydroxalase, and aromatase. Collectively, these data indicate that equol inhibits growth, increases atresia, and inhibits steroidogenesis of cultured mouse antral follicles. - Highlights: • Equol exposure inhibits antral follicle growth. • Equol exposure increases follicle atresia. • Equol exposure inhibits sex steroid hormone levels. • Equol exposure inhibits mRNA levels of certain steroidogenic enzymes.

  9. Equol inhibits growth, induces atresia, and inhibits steroidogenesis of mouse antral follicles in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Mahalingam, Sharada, E-mail: mahalin2@illinois.edu [Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois, 2001 S. Lincoln Ave, Urbana, IL 61802 (United States); Gao, Liying, E-mail: lgao@uiuc.edu [Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois, 2001 S. Lincoln Ave, Urbana, IL 61802 (United States); Gonnering, Marni, E-mail: mgonne2@illinois.edu [Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois, 2001 S. Lincoln Ave, Urbana, IL 61802 (United States); Helferich, William, E-mail: helferic@illinois.edu [Department of Food Science and Human Nutrition, University of Illinois, 905 S. Goodwin, Urbana, IL 61801 (United States); Flaws, Jodi A., E-mail: jflaws@illinois.edu [Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois, 2001 S. Lincoln Ave, Urbana, IL 61802 (United States)

    2016-03-15

    Equol is a non-steroidal estrogen metabolite produced by microbial conversion of daidzein, a major soy isoflavone, in the gut of some humans and many animal species. Isoflavones and their metabolites can affect endogenous estradiol production, action, and metabolism, potentially influencing ovarian follicle function. However, no studies have examined the effects of equol on intact ovarian antral follicles, which are responsible for sex steroid synthesis and further development into ovulatory follicles. Thus, the present study tested the hypothesis that equol inhibits antral follicle growth, increases follicle atresia, and inhibits steroidogenesis in the adult mouse ovary. To test this hypothesis, antral follicles isolated from adult CD-1 mice were cultured with vehicle control (dimethyl sulfoxide; DMSO) or equol (600 nM, 6 μM, 36 μM, and 100 μM) for 48 and 96 h. Every 24 h, follicle diameters were measured to monitor growth. At 48 and 96 h, the culture medium was subjected to measurement of hormone levels, and the cultured follicles were subjected to gene expression analysis. Additionally, follicles were histologically evaluated for signs of atresia after 96 h of culture. The results indicate that equol (100 μM) inhibited follicle growth, altered the mRNA levels of bcl2-associated X protein and B cell leukemia/lymphoma 2, and induced follicle atresia. Further, equol decreased the levels of estradiol, testosterone, androstenedione, and progesterone, and it decreased mRNA levels of cholesterol side-chain cleavage, steroid 17-α-hydroxalase, and aromatase. Collectively, these data indicate that equol inhibits growth, increases atresia, and inhibits steroidogenesis of cultured mouse antral follicles. - Highlights: • Equol exposure inhibits antral follicle growth. • Equol exposure increases follicle atresia. • Equol exposure inhibits sex steroid hormone levels. • Equol exposure inhibits mRNA levels of certain steroidogenic enzymes.

  10. Molecular mechanisms of induced-mutations

    International Nuclear Information System (INIS)

    Kato, Takeshi

    1985-01-01

    The outcome of recent studies on mechanisms of induced-mutations is outlined with particular emphasis on the dependence of recA gene function in Escherichia coli. Genes involved in spontaneous mutation and x-ray- and chemical-induced mutation and genes involved in adaptive response are presented. As for SOS mutagenesis, SOS-induced regulation mechanisms and mutagenic routes are described. Furthermore, specificity of mutagens themselves are discussed in relation to mechanisms of base substitution, frameshift, and deletion mutagenesis. (Namekawa, K.)

  11. Blockade of store-operated calcium entry alleviates ethanol-induced hepatotoxicity via inhibiting apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Ruibing [Department of Hepatology and Gastroenterology, Qilu Hospital of Shandong University, Jinan, Shandong Province 250012 (China); Yan, Lihui [Shandong Normal University, Jinan, Shandong Province 250012 (China); Luo, Zheng; Guo, Xiaolan [Department of Hepatology and Gastroenterology, Qilu Hospital of Shandong University, Jinan, Shandong Province 250012 (China); Yan, Ming, E-mail: ymylh@163.com [Department of Hepatology and Gastroenterology, Qilu Hospital of Shandong University, Jinan, Shandong Province 250012 (China)

    2015-08-15

    Extracellular Ca{sup 2+} influx has been suggested to play a role in ethanol-induced hepatocyte apoptosis and necrosis. Previous studies indicated that store-operated Ca{sup 2+} entry (SOCE) was involved in liver injury induced by ethanol in HepG2 cells. However, the mechanisms underlying liver injury caused by SOCE remain unclear. We aimed to investigate the effects and mechanism of SOCE inhibition on liver injury induced by ethanol in BRL cells and Sprague–Dawley rats. Our data demonstrated that ethanol (0–400 mM) dose-dependently increased hepatocyte injury and 100 mM ethanol significantly upregulated the mRNA and protein expression of SOC for at least 72 h in BRL cells. Blockade of SOCE by pharmacological inhibitors and sh-RNA knockdown of STIM1 and Orai1 attenuated intracellular Ca{sup 2+} overload, restored the mitochondrial membrane potential (MMP), decreased cytochrome C release and inhibited ethanol-induced apoptosis. STIM1 and Orai1 expression was greater in ethanol-treated than control rats, and the SOCE inhibitor corosolic acid ameliorated the histopathological findings and alanine transaminase and aspartate transaminase activity as well as decreased cytochrome C release and inhibited alcohol-induced cell apoptosis. These findings suggest that SOCE blockade could alleviate alcohol-induced hepatotoxicity via inhibiting apoptosis. SOCE might be a useful therapeutic target in alcoholic liver diseases. - Highlights: • Blockade of SOCE alleviated overload of Ca{sup 2+} and hepatotoxicity after ethanol application. • Blockade of SOCE inhibited mitochondrial apoptosis after ethanol application. • SOCE might be a useful therapeutic target in alcoholic liver diseases.

  12. Salmonella infection inhibits intestinal biotin transport: cellular and molecular mechanisms.

    Science.gov (United States)

    Ghosal, Abhisek; Jellbauer, Stefan; Kapadia, Rubina; Raffatellu, Manuela; Said, Hamid M

    2015-07-15

    Infection with the nontyphoidal Salmonella is a common cause of food-borne disease that leads to acute gastroenteritis/diarrhea. Severe/prolonged cases of Salmonella infection could also impact host nutritional status, but little is known about its effect on intestinal absorption of vitamins, including biotin. We examined the effect of Salmonella enterica serovar Typhimurium (S. typhimurium) infection on intestinal biotin uptake using in vivo (streptomycin-pretreated mice) and in vitro [mouse (YAMC) and human (NCM460) colonic epithelial cells, and human intestinal epithelial Caco-2 cells] models. The results showed that infecting mice with wild-type S. typhimurium, but not with its nonpathogenic isogenic invA spiB mutant, leads to a significant inhibition in jejunal/colonic biotin uptake and in level of expression of the biotin transporter, sodium-dependent multivitamin transporter. In contrast, infecting YAMC, NCM460, and Caco-2 cells with S. typhimurium did not affect biotin uptake. These findings suggest that the effect of S. typhimurium infection is indirect and is likely mediated by proinflammatory cytokines, the levels of which were markedly induced in the intestine of S. typhimurium-infected mice. Consistent with this hypothesis, exposure of NCM460 cells to the proinflammatory cytokines TNF-α and IFN-γ led to a significant inhibition of biotin uptake, sodium-dependent multivitamin transporter expression, and activity of the SLC5A6 promoter. The latter effects appear to be mediated, at least in part, via the NF-κB signaling pathway. These results demonstrate that S. typhimurium infection inhibits intestinal biotin uptake, and that the inhibition is mediated via the action of proinflammatory cytokines.

  13. Molecular mechanisms of induced pluripotency.

    Science.gov (United States)

    Kulcenty, Katarzyna; Wróblewska, Joanna; Mazurek, Sylwia; Liszewska, Ewa; Jaworski, Jacek

    2015-01-01

    Growing knowledge concerning transcriptional control of cellular pluripotency has led to the discovery that the fate of differentiated cells can be reversed, which has resulted in the generation, by means of genetic manipulation, of induced pluripotent stem cells. Overexpression of just four pluripotency-related transcription factors, namely Oct3/4, Sox2, Klf4, and c-Myc (Yamanaka factors, OKSM), in fibroblasts appears sufficient to produce this new cell type. Currently, we know that these factors induce several changes in genetic program of differentiated cells that can be divided in two general phases: the initial one is stochastic, and the subsequent one is highly hierarchical and organised. This review briefly discusses the molecular events leading to induction of pluripotency in response to forced presence of OKSM factors in somatic cells. We also discuss other reprogramming strategies used thus far as well as the advantages and disadvantages of laboratory approaches towards pluripotency induction in different cell types.

  14. Eleutheroside E inhibits doxorubicin-induced inflammation and ...

    African Journals Online (AJOL)

    Purpose: To identify the effects of eleutheroside E (EE) on apoptosis and inflammation induced by doxorubicin (DOX) in H9c2 cells and to investigate the underlying mechanisms. Methods: The effect of EE on H9c2 cell viability was determined using Cell Counting Kit-8 (CCK8). EE effect on DOX-induced apoptosis and ...

  15. Inhibition of coronary blood flow by a vascular waterfall mechanism.

    Science.gov (United States)

    Downey, J M; Kirk, E S

    1975-06-01

    The mechanism whereby systole inhibits coronary blood flow was examined. A branch of the left coronary artery was maximally dilated with an adenosine infusion, and the pressure-flow relationship was obtained for beating and arrested states. The pressure-flow curve for the arrested state was shifted toward higher pressures and in the range of pressures above peak ventricular pressure was linear and parallel to that for the arrested state. Below this range the curve for the beating state converged toward that for the arrested state and was convex to the pressure axis. These results were compared with a model of the coronary vasculature that consisted of numerous parallel channels, each responding to local intramyocardial pressure by forming vascular waterfalls. When intramyocardial pressure in the model was assigned values from zero at the epicardium to peak ventricular pressure at the endocardium, pressure-flow curves similar to the experimental ones resulted. Thus, we conclude that systole inhibits coronary perfusion by the formation of vascular waterfalls and that the intramyocardial pressures responsible for this inhibition do not significantly exceed peak ventricular pressure.

  16. Paeoniflorin inhibits cell growth and induces cell cycle arrest through inhibition of FoxM1 in colorectal cancer cells.

    Science.gov (United States)

    Yue, Meng; Li, Shiquan; Yan, Guoqiang; Li, Chenyao; Kang, Zhenhua

    2018-01-01

    Paeoniflorin (PF) exhibits tumor suppressive functions in a variety of human cancers. However, the function of PF and molecular mechanism in colorectal cancer are elusive. In the present study, we investigated whether PF could exert its antiproliferative activity, anti-migration, and anti-invasive function in colorectal cancer cells. We found that PF inhibited cell growth and induced apoptosis and blocked cell cycle progression in the G0/G1 phase in colorectal cancer cells. Moreover, we found that PF suppressed cell migration and invasion in colorectal cancer cells. FoxM1 has been reported to play an important oncogenic role in human cancers. We also determine whether PF inhibited the expression of FoxM1, leading to its anti-cancer activity. We found that PF treatment in colorectal cancer cells resulted in down-regulation of FoxM1. The rescue experiments showed that overexpression of FoxM1 abrogated the tumor suppressive function induced by PF treatment. Notably, depletion of FoxM1 promoted the anti-tumor activity of PF in colorectal cancer cells. Therefore, inhibition of FoxM1 could participate in the anti-tumor activity of PF in colorectal cancer cells.

  17. δ-Tocopherol inhibits receptor tyrosine kinase-induced AKT activation in prostate cancer cells.

    Science.gov (United States)

    Wang, Hong; Hong, Jungil; Yang, Chung S

    2016-11-01

    The cancer preventive activity of vitamin E is suggested by epidemiological studies and supported by animal studies with vitamin E forms, γ-tocopherol and δ-tocopherol (δ-T). Several recent large-scale cancer prevention trials with high dose of α-tocopherol, however, yielded disappointing results. Whether vitamin E prevents or promotes cancer is a serious concern. A better understanding of the molecular mechanisms of action of the different forms of tocopherols would enhance our understanding of this topic. In this study, we demonstrated that δ-T was the most effective tocopherol form in inhibiting prostate cancer cell growth, by inducing cell cycle arrest and apoptosis. By profiling the effects of δ-T on the cell signaling using the phospho-kinase array, we found that the most inhibited target was the phosphorylation of AKT on T308. Further study on the activation of AKT by EGFR and IGFR revealed that δ-T attenuated the EGF/IGF-induced activation of AKT (via the phosphorylation of AKT on T308 induced by the activation of PIK3). Expression of dominant active PIK3 and AKT in prostate cancer cell line DU145 in which PIK3, AKT, and PTEN are wild type caused the cells to be reflectory to the inhibition of δ-T, supporting that δ-T inhibits the PIK3-mediated activation of AKT. Our data also suggest that δ-T interferes with the EGF-induced EGFR internalization, which leads to the inhibition of the receptor tyrosine kinase-dependent activation of AKT. In summary, our results revealed a novel mechanism of δ-T in inhibiting prostate cancer cell growth, supporting the cancer preventive activity δ-T. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  18. The mechanism of OTUB1-mediated inhibition of ubiquitination

    Energy Technology Data Exchange (ETDEWEB)

    Wiener, Reuven; Zhang, Xiangbin; Wang, Tao; Wolberger, Cynthia (JHU)

    2013-04-08

    Histones are ubiquitinated in response to DNA double-strand breaks (DSB), promoting recruitment of repair proteins to chromatin. UBC13 (also known as UBE2N) is a ubiquitin-conjugating enzyme (E2) that heterodimerizes with UEV1A (also known as UBE2V1) and synthesizes K63-linked polyubiquitin (K63Ub) chains at DSB sites in concert with the ubiquitin ligase (E3), RNF168 (ref. 3). K63Ub synthesis is regulated in a non-canonical manner by the deubiquitinating enzyme, OTUB1 (OTU domain-containing ubiquitin aldehyde-binding protein 1), which binds preferentially to the UBC13-Ub thiolester. Residues amino-terminal to the OTU domain, which had been implicated in ubiquitin binding, are required for binding to UBC13-Ub and inhibition of K63Ub synthesis. Here we describe structural and biochemical studies elucidating how OTUB1 inhibits UBC13 and other E2 enzymes. We unexpectedly find that OTUB1 binding to UBC13-Ub is allosterically regulated by free ubiquitin, which binds to a second site in OTUB1 and increases its affinity for UBC13-Ub, while at the same time disrupting interactions with UEV1A in a manner that depends on the OTUB1 N terminus. Crystal structures of an OTUB1-UBC13 complex and of OTUB1 bound to ubiquitin aldehyde and a chemical UBC13-Ub conjugate show that binding of free ubiquitin to OTUB1 triggers conformational changes in the OTU domain and formation of a ubiquitin-binding helix in the N terminus, thus promoting binding of the conjugated donor ubiquitin in UBC13-Ub to OTUB1. The donor ubiquitin thus cannot interact with the E2 enzyme, which has been shown to be important for ubiquitin transfer. The N-terminal helix of OTUB1 is positioned to interfere with UEV1A binding to UBC13, as well as with attack on the thiolester by an acceptor ubiquitin, thereby inhibiting K63Ub synthesis. OTUB1 binding also occludes the RING E3 binding site on UBC13, thus providing a further component of inhibition. The general features of the inhibition mechanism explain how OTUB1

  19. Boric acid inhibits embryonic histone deacetylases: A suggested mechanism to explain boric acid-related teratogenicity

    International Nuclear Information System (INIS)

    Di Renzo, Francesca; Cappelletti, Graziella; Broccia, Maria L.; Giavini, Erminio; Menegola, Elena

    2007-01-01

    Histone deacetylases (HDAC) control gene expression by changing histonic as well as non histonic protein conformation. HDAC inhibitors (HDACi) are considered to be among the most promising drugs for epigenetic treatment for cancer. Recently a strict relationship between histone hyperacetylation in specific tissues of mouse embryos exposed to two HDACi (valproic acid and trichostatin A) and specific axial skeleton malformations has been demonstrated. The aim of this study is to verify if boric acid (BA), that induces in rodents malformations similar to those valproic acid and trichostatin A-related, acts through similar mechanisms: HDAC inhibition and histone hyperacetylation. Pregnant mice were treated intraperitoneally with a teratogenic dose of BA (1000 mg/kg, day 8 of gestation). Western blot analysis and immunostaining were performed with anti hyperacetylated histone 4 (H4) antibody on embryos explanted 1, 3 or 4 h after treatment and revealed H4 hyperacetylation at the level of somites. HDAC enzyme assay was performed on embryonic nuclear extracts. A significant HDAC inhibition activity (compatible with a mixed type partial inhibition mechanism) was evident with BA. Kinetic analyses indicate that BA modifies substrate affinity by a factor α = 0.51 and maximum velocity by a factor β = 0.70. This work provides the first evidence for HDAC inhibition by BA and suggests such a molecular mechanism for the induction of BA-related malformations

  20. Ebselen: Mechanisms of Glutamate Dehydrogenase and Glutaminase Enzyme Inhibition.

    Science.gov (United States)

    Yu, Yan; Jin, Yanhong; Zhou, Jie; Ruan, Haoqiang; Zhao, Han; Lu, Shiying; Zhang, Yue; Li, Di; Ji, Xiaoyun; Ruan, Benfang Helen

    2017-12-15

    Ebselen modulates target proteins through redox reactions with selenocysteine/cysteine residues, or through binding to the zinc finger domains. However, a recent contradiction in ebselen inhibition of kidney type glutaminase (KGA) stimulated our interest in investigating its inhibition mechanism with glutamate dehydrogenase (GDH), KGA, thioredoxin reductase (TrxR), and glutathione S-transferase. Fluorescein- or biotin-labeled ebselen derivatives were synthesized for mechanistic analyses. Biomolecular interaction analyses showed that only GDH, KGA, and TrxR proteins can bind to the ebselen derivative, and the binding to GDH and KGA could be competed off by glutamine or glutamate. From the gel shift assays, the fluorescein-labeled ebselen derivative could co-migrate with hexameric GDH and monomeric/dimeric TrxR in a dose-dependent manner; it also co-migrated with KGA but disrupted the tetrameric form of the KGA enzyme at a high compound concentration. Further proteomic analysis demonstrated that the ebselen derivative could cross-link with proteins through a specific cysteine at the active site of GDH and TrxR proteins, but for KGA protein, the binding site is at the N-terminal appendix domain outside of the catalytic domain, which might explain why ebselen is not a potent KGA enzyme inhibitor in functional assays. In conclusion, ebselen could inhibit enzyme activity by binding to the catalytic domain or disruption of the protein complex. In addition, ebselen is a relatively potent selective GDH inhibitor that might provide potential therapeutic opportunities for hyperinsulinism-hyperammonemia syndrome patients who have the mutational loss of GTP inhibition.

  1. Linear ubiquitin chain induces apoptosis and inhibits tumor growth.

    Science.gov (United States)

    Qin, Zhoushuai; Jiang, Wandong; Wang, Guifen; Sun, Ying; Xiao, Wei

    2018-01-01

    Ubiquitination of proliferating cell nuclear antigen (PCNA) plays an important role in DNA damage response. Ectopic expression of PCNA fused at either terminus with ubiquitin (Ub) lacking two C-terminal glycine residues induces translesion DNA synthesis which resembles synthesis mediated by PCNA monoubiquitination. PCNA fused with Ub containing the C-terminal Gly residues at the C-terminus can be further polyubiquitinated in a Gly-dependent manner, which inhibits cell proliferation and induces ATR-dependent replication checkpoint. In this study, we surprisingly found that PCNA fused to a head-to-tail linear Ub chain induces apoptosis in a Ub chain length-dependent manner. Further investigation revealed that the apoptotic effect is actually induced by the linear Ub chain independently from PCNA, as the Ub chain fused to GFP or an epitope tag still efficiently induces apoptosis. It is revealed that the artificial linear Ub chain differs from endogenously encoded linear Ub chains in that its Ubs contain a Ub-G76S substitution, making the Ub chain resistant to cleavage by deubiquitination enzymes. We demonstrated in this study that ectopic expression of the artificial Ub chain alone in cultured human cancer cells is sufficient to inhibit tumor growth in a xenograft mouse model, making the linear Ub chain a putative anti-cancer agent.

  2. Zinc finger protein 598 inhibits cell survival by promoting UV-induced apoptosis.

    Science.gov (United States)

    Yang, Qiaohong; Gupta, Romi

    2018-01-19

    UV is one of the major causes of DNA damage induced apoptosis. However, cancer cells adopt alternative mechanisms to evade UV-induced apoptosis. To identify factors that protect cancer cells from UV-induced apoptosis, we performed a genome wide short-hairpin RNA (shRNA) screen, which identified Zinc finger protein 598 (ZNF598) as a key regulator of UV-induced apoptosis. Here, we show that UV irradiation transcriptionally upregulates ZNF598 expression. Additionally, ZNF598 knockdown in cancer cells inhibited UV-induced apoptosis. In our study, we observe that ELK1 mRNA level as well as phosphorylated ELK1 levels was up regulated upon UV irradiation, which was necessary for UV irradiation induced upregulation of ZNF598. Cells expressing ELK1 shRNA were also resistant to UV-induced apoptosis, and phenocopy ZNF598 knockdown. Upon further investigation, we found that ZNF598 knockdown inhibits UV-induced apoptotic gene expression, which matches with decrease in percentage of annexin V positive cell. Similarly, ectopic expression of ZNF598 promoted apoptotic gene expression and also increased annexin V positive cells. Collectively, these results demonstrate that ZNF598 is a UV irradiation regulated gene and its loss results in resistance to UV-induced apoptosis.

  3. Leflunomide/teriflunomide inhibit Epstein-Barr virus (EBV)- induced lymphoproliferative disease and lytic viral replication.

    Science.gov (United States)

    Bilger, Andrea; Plowshay, Julie; Ma, Shidong; Nawandar, Dhananjay; Barlow, Elizabeth A; Romero-Masters, James C; Bristol, Jillian A; Li, Zhe; Tsai, Ming-Han; Delecluse, Henri-Jacques; Kenney, Shannon C

    2017-07-04

    EBV infection causes mononucleosis and is associated with specific subsets of B cell lymphomas. Immunosuppressed patients such as organ transplant recipients are particularly susceptible to EBV-induced lymphoproliferative disease (LPD), which can be fatal. Leflunomide (a drug used to treat rheumatoid arthritis) and its active metabolite teriflunomide (used to treat multiple sclerosis) inhibit de novo pyrimidine synthesis by targeting the cellular dihydroorotate dehydrogenase, thereby decreasing T cell proliferation. Leflunomide also inhibits the replication of cytomegalovirus and BK virus via both "on target" and "off target" mechanisms and is increasingly used to treat these viruses in organ transplant recipients. However, whether leflunomide/teriflunomide block EBV replication or inhibit EBV-mediated B cell transformation is currently unknown. We show that teriflunomide inhibits cellular proliferation, and promotes apoptosis, in EBV-transformed B cells in vitro at a clinically relevant dose. In addition, teriflunomide prevents the development of EBV-induced lymphomas in both a humanized mouse model and a xenograft model. Furthermore, teriflunomide inhibits lytic EBV infection in vitro both by preventing the initial steps of lytic viral reactivation, and by blocking lytic viral DNA replication. Leflunomide/teriflunomide might therefore be clinically useful for preventing EBV-induced LPD in patients who have high EBV loads yet require continued immunosuppression.

  4. Sympathetic β-adrenergic mechanism in pudendal inhibition of nociceptive and non-nociceptive reflex bladder activity.

    Science.gov (United States)

    Kadow, Brian T; Lyon, Timothy D; Zhang, Zhaocun; Lamm, Vladimir; Shen, Bing; Wang, Jicheng; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2016-07-01

    This study investigated the role of the hypogastric nerve and β-adrenergic mechanisms in the inhibition of nociceptive and non-nociceptive reflex bladder activity induced by pudendal nerve stimulation (PNS). In α-chloralose-anesthetized cats, non-nociceptive reflex bladder activity was induced by slowly infusing saline into the bladder, whereas nociceptive reflex bladder activity was induced by replacing saline with 0.25% acetic acid (AA) to irritate the bladder. PNS was applied at multiple threshold (T) intensities for inducing anal sphincter twitching. During saline infusion, PNS at 2T and 4T significantly (P reflex bladder activity. In addition to this peripheral mechanism, a central nervous system mechanism involving metabotropic glutamate 5 receptors also has a role in PNS inhibition. Copyright © 2016 the American Physiological Society.

  5. Cordycepin Induces Apoptosis and Inhibits Proliferation of Human Lung Cancer Cell Line H1975 via Inhibiting the Phosphorylation of EGFR

    Directory of Open Access Journals (Sweden)

    Zheng Wang

    2016-09-01

    Full Text Available Cordycepin is an active component of the traditional Chinese medicine Cordyceps sinensis and Cordyceps militaris with notable anticancer activity. Though the prominent inhibitory activity was reported in different kinds of cancer cell lines, the concrete mechanisms remain elusive. It was reported that cordycepin could be converted into tri-phosphates in vivo to confuse a number of enzymes and interfere the normal cell function. For the inhibitory mechanism of EGFR inhibitors and the structure similarity of ATP and tri-phosphated cordycepin, human lung cancer cell line H1975 was employed to investigate the inhibitory effect of cordycepin. The results showed that cordycepin could inhibit cell proliferation and induce apoptosis in a dose-dependent manner. Cell cycle analysis revealed that H1975 cells could be arrested at the G0/G1 phase after cordycepin treatment. The expression levels of apoptosis-related protein Caspase-3 and Bcl-2 and phosphorylated expression levels of EGFR, AKT and ERK1/2 were all decreased compared with the control group stimulated with EGF. However, the protein expression levels of proapoptotic protein Bax and cleaved caspase-3 were increased. These results implied that cordycepin could inhibit cell proliferation and induce apoptosis via the EGFR signaling pathway. Our results indicated that there was potential to seek a novel EGFR inhibitor from cordycepin and its chemical derivatives.

  6. Joint immobilization inhibits spontaneous hyaline cartilage regeneration induced by a novel double-network gel implantation.

    Science.gov (United States)

    Arakaki, Kazunobu; Kitamura, Nobuto; Kurokawa, Takayuki; Onodera, Shin; Kanaya, Fuminori; Gong, Jian-Ping; Yasuda, Kazunori

    2011-02-01

    We have recently discovered that spontaneous hyaline cartilage regeneration can be induced in an osteochondral defect in the rabbit, when we implant a novel double-network (DN) gel plug at the bottom of the defect. To clarify whether joint immobilization inhibits the spontaneous hyaline cartilage regeneration, we conducted this study with 20 rabbits. At 4 or 12 weeks after surgery, the defect in the mobile knees was filled with a sufficient volume of the hyaline cartilage tissue rich in proteoglycan and type-2 collagen, while no cartilage tissues were observed in the defect in the immobilized knees. Type-2 collagen, Aggrecan, and SOX9 mRNAs were expressed only in the mobile knees at each period. This study demonstrated that joint immobilization significantly inhibits the spontaneous hyaline cartilage regeneration induced by the DN gel implantation. This fact suggested that the mechanical environment is one of the significant factors to induce this phenomenon.

  7. Cladribine and Fludarabine Nucleotides Induce Distinct Hexamers Defining a Common Mode of Reversible RNR Inhibition.

    Science.gov (United States)

    Wisitpitthaya, Somsinee; Zhao, Yi; Long, Marcus J C; Li, Minxing; Fletcher, Elaine A; Blessing, William A; Weiss, Robert S; Aye, Yimon

    2016-07-15

    The enzyme ribonucleotide reductase (RNR) is a major target of anticancer drugs. Until recently, suicide inactivation in which synthetic substrate analogs (nucleoside diphosphates) irreversibly inactivate the RNR-α2β2 heterodimeric complex was the only clinically proven inhibition pathway. For instance, this mechanism is deployed by the multifactorial anticancer agent gemcitabine diphosphate. Recently reversible targeting of RNR-α-alone coupled with ligand-induced RNR-α-persistent hexamerization has emerged to be of clinical significance. To date, clofarabine nucleotides are the only known example of this mechanism. Herein, chemoenzymatic syntheses of the active forms of two other drugs, phosphorylated cladribine (ClA) and fludarabine (FlU), allow us to establish that reversible inhibition is common to numerous drugs in clinical use. Enzyme inhibition and fluorescence anisotropy assays show that the di- and triphosphates of the two nucleosides function as reversible (i.e., nonmechanism-based) inhibitors of RNR and interact with the catalytic (C site) and the allosteric activity (A site) sites of RNR-α, respectively. Gel filtration, protease digestion, and FRET assays demonstrate that inhibition is coupled with formation of conformationally diverse hexamers. Studies in 293T cells capable of selectively inducing either wild-type or oligomerization-defective mutant RNR-α overexpression delineate the central role of RNR-α oligomerization in drug activity, and highlight a potential resistance mechanism to these drugs. These data set the stage for new interventions targeting RNR oligomeric regulation.

  8. Implication of unfolded protein response in resveratrol-induced inhibition of K562 cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bao-Qin; Gao, Yan-Yan; Niu, Xiao-Fang [Department of Biochemistry and Molecular Biology, China Medical University, Shenyang 110001 (China); Xie, Ji-Sheng [Youjiang Medical College for Nationalities, Guangxi 533000 (China); Meng, Xin; Guan, Yifu [Department of Biochemistry and Molecular Biology, China Medical University, Shenyang 110001 (China); Wang, Hua-Qin, E-mail: wanghq_doctor@hotmail.com [Department of Biochemistry and Molecular Biology, China Medical University, Shenyang 110001 (China)

    2010-01-01

    Resveratrol (RES), a natural plant polyphenol, is an effective inducer of cell cycle arrest and apoptosis in a variety of carcinoma cell types. In addition, RES has been reported to inhibit tumorigenesis in several animal models suggesting that it functions as a chemopreventive and anti-tumor agent in vivo. The chemopreventive and chemotherapeutic properties associated with resveratrol offer promise for the design of new chemotherapeutic agents. However, the mechanisms by which RES mediates its effects are not yet fully understood. In this study, we showed that RES caused cell cycle arrest and proliferation inhibition via induction of unfolded protein response (UPR) in human leukemia K562 cell line. Treatment of K562 cells with RES induced a number of signature UPR markers, including transcriptional induction of GRP78 and CHOP, phosphorylation of eukaryotic initiation factor 2{alpha} (eIF2{alpha}), ER stress-specific XBP-1 splicing, suggesting the induction of UPR by RES. RES inhibited proliferation of K562 in a concentration-dependent manner. Flow cytometric analyses revealed that K562 cells were arrested in G1 phase upon RES treatment. Salubrinal, an eIF2{alpha} inhibitor, or overexpression of dominant negative mutants of PERK or eIF2{alpha}, effectively restored RES-induced cell cycle arrest, underscoring the important role of PERK/eIF2{alpha} branch of UPR in RES-induced inhibition of cell proliferation.

  9. Implication of unfolded protein response in resveratrol-induced inhibition of K562 cell proliferation

    International Nuclear Information System (INIS)

    Liu, Bao-Qin; Gao, Yan-Yan; Niu, Xiao-Fang; Xie, Ji-Sheng; Meng, Xin; Guan, Yifu; Wang, Hua-Qin

    2010-01-01

    Resveratrol (RES), a natural plant polyphenol, is an effective inducer of cell cycle arrest and apoptosis in a variety of carcinoma cell types. In addition, RES has been reported to inhibit tumorigenesis in several animal models suggesting that it functions as a chemopreventive and anti-tumor agent in vivo. The chemopreventive and chemotherapeutic properties associated with resveratrol offer promise for the design of new chemotherapeutic agents. However, the mechanisms by which RES mediates its effects are not yet fully understood. In this study, we showed that RES caused cell cycle arrest and proliferation inhibition via induction of unfolded protein response (UPR) in human leukemia K562 cell line. Treatment of K562 cells with RES induced a number of signature UPR markers, including transcriptional induction of GRP78 and CHOP, phosphorylation of eukaryotic initiation factor 2α (eIF2α), ER stress-specific XBP-1 splicing, suggesting the induction of UPR by RES. RES inhibited proliferation of K562 in a concentration-dependent manner. Flow cytometric analyses revealed that K562 cells were arrested in G1 phase upon RES treatment. Salubrinal, an eIF2α inhibitor, or overexpression of dominant negative mutants of PERK or eIF2α, effectively restored RES-induced cell cycle arrest, underscoring the important role of PERK/eIF2α branch of UPR in RES-induced inhibition of cell proliferation.

  10. The histone deacetylase inhibitor, Vorinostat, represses hypoxia inducible factor 1 alpha expression through translational inhibition.

    Directory of Open Access Journals (Sweden)

    Darren M Hutt

    Full Text Available Hypoxia inducible factor 1α (HIF-1α is a master regulator of tumor angiogenesis being one of the major targets for cancer therapy. Previous studies have shown that Histone Deacetylase Inhibitors (HDACi block tumor angiogenesis through the inhibition of HIF-1α expression. As such, Vorinostat (Suberoylanilide Hydroxamic Acid/SAHA and Romidepsin, two HDACis, were recently approved by the Food and Drug Administration (FDA for the treatment of cutaneous T cell lymphoma. Although HDACis have been shown to affect HIF-1α expression by modulating its interactions with the Hsp70/Hsp90 chaperone axis or its acetylation status, the molecular mechanisms by which HDACis inhibit HIF-1α expression need to be further characterized. Here, we report that the FDA-approved HDACi Vorinostat/SAHA inhibits HIF-1α expression in liver cancer-derived cell lines, by a new mechanism independent of p53, prolyl-hydroxylases, autophagy and proteasome degradation. We found that SAHA or silencing of HDAC9 mechanism of action is due to inhibition of HIF-1α translation, which in turn, is mediated by the eukaryotic translation initiation factor--eIF3G. We also highlighted that HIF-1α translation is dramatically inhibited when SAHA is combined with eIF3H silencing. Taken together, we show that HDAC activity regulates HIF-1α translation, with HDACis such as SAHA representing a potential novel approach for the treatment of hepatocellular carcinoma.

  11. Celastrol nanoparticles inhibit corneal neovascularization induced by suturing in rats

    Directory of Open Access Journals (Sweden)

    Li ZR

    2012-03-01

    Full Text Available Zhanrong Li1, Lin Yao1, Jingguo Li2, Wenxin Zhang1, Xianghua Wu1, Yi Liu1, Miaoli Lin1, Wenru Su1, Yongping Li1, Dan Liang11State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, 2School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, People's Republic of ChinaPurpose: Celastrol, a traditional Chinese medicine, is widely used in anti-inflammation and anti-angiogenesis research. However, the poor water solubility of celastrol restricts its further application. This paper aims to study the effect of celastrol nanoparticles (CNPs on corneal neovascularization (CNV and determine the possible mechanism.Methods: To improve the hydrophilicity of celastrol, celastrol-loaded poly(ethylene glycol-block-poly(ε-caprolactone nanopolymeric micelles were developed. The characterization of CNPs was measured by dynamic light scattering and transmission electron microscopy analysis. Celastrol loading content and release were assessed by ultraviolet-visible analysis and high performance liquid chromatography, respectively. In vitro, human umbilical vein endothelial cell proliferation and capillary-like tube formation were assayed. In vivo, suture-induced CNV was chosen to evaluate the effect of CNPs on CNV in rats. Immunohistochemistry for CD68 assessed the macrophage infiltration of the cornea on day 6 after surgery. Real-time quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay were used to evaluate the messenger ribonucleic acid and protein levels, respectively, of vascular endothelial growth factor, matrix metalloproteinase 9, and monocyte chemoattractant protein 1 in the cornea.Results: The mean diameter of CNPs with spherical shape was 48 nm. The celastrol loading content was 7.36%. The release behavior of CNPs in buffered solution (pH 7.4 showed a typical two-phase release profile. CNPs inhibited the proliferation of human umbilical vein endothelial

  12. Statins induce apoptosis in rat and human myotube cultures by inhibiting protein geranylgeranylation but not ubiquinone

    International Nuclear Information System (INIS)

    Johnson, Timothy E.; Zhang, Xiaohua; Bleicher, Kimberly B.; Dysart, Gary; Loughlin, Amy F.; Schaefer, William H.; Umbenhauer, Diane R.

    2004-01-01

    Statins are widely used to treat lipid disorders. These drugs are safe and well tolerated; however, in <1% of patients, myopathy and/or rhabdomyolysis can develop. To better understand the mechanism of statin-induced myopathy, we examined the ability of structurally distinct statins to induce apoptosis in an optimized rat myotube model. Compound A (a lactone) and Cerivastatin (an open acid) induced apoptosis, as measured by TUNEL and active caspase 3 staining, in a concentration- and time-dependent manner. In contrast, an epimer of Compound A (Compound B) exhibited a much weaker apoptotic response. Statin-induced apoptosis was completely prevented by mevalonate or geranylgeraniol, but not by farnesol. Zaragozic acid A, a squalene synthase inhibitor, caused no apoptosis on its own and had no effect on Compound-A-induced myotoxicity, suggesting the apoptosis was not a result of cholesterol synthesis inhibition. The geranylgeranyl transferase inhibitors GGTI-2133 and GGTI-2147 caused apoptosis in myotubes; the farnesyl transferase inhibitor FTI-277 exhibited a much weaker effect. In addition, the prenylation of rap1a, a geranylgeranylated protein, was inhibited by Compound A in myotubes at concentrations that induced apoptosis. A similar statin-induced apoptosis profile was seen in human myotube cultures but primary rat hepatocytes were about 200-fold more resistant to statin-induced apoptosis. Although the statin-induced hepatotoxicity could be attenuated with mevalonate, no effect was found with either geranylgeraniol or farnesol. In studies assessing ubiquinone levels after statin treatment in rat and human myotubes, there was no correlation between ubiquinone levels and apoptosis. Taken together, these observations suggest that statins cause apoptosis in myotube cultures in part by inhibiting the geranylgeranylation of proteins, but not by suppressing ubiquinone concentration. Furthermore, the data from primary hepatocytes suggests a cell-type differential

  13. Hyperosmotic stress inhibits insulin receptor substrate-1 function by distinct mechanisms in 3T3-L1 adipocytes

    DEFF Research Database (Denmark)

    Gual, Philippe; Gonzalez, Teresa; Grémeaux, Thierry

    2003-01-01

    . Furthermore, the mammalian target of rapamycin (mTOR) inhibitor rapamycin prevented the osmotic shock-induced phosphorylation of IRS-1 on Ser307. The inhibition of mTOR completely reversed the inhibitory effect of hyperosmotic stress on insulin-induced IRS-1 tyrosine phosphorylation and PI 3-kinase activation......In 3T3-L1 adipocytes, hyperosmotic stress was found to inhibit insulin signaling, leading to an insulin-resistant state. We show here that, despite normal activation of insulin receptor, hyperosmotic stress inhibits both tyrosine phosphorylation of insulin receptor substrate-1 (IRS-1) and IRS-1....... In addition, prolonged osmotic stress enhanced the degradation of IRS proteins through a rapamycin-insensitive pathway and a proteasome-independent process. These data support evidence of new mechanisms involved in osmotic stress-induced cellular insulin resistance. Short-term osmotic stress induces...

  14. Detailed mechanism of squalene epoxidase inhibition by terbinafine.

    Science.gov (United States)

    Nowosielski, Marcin; Hoffmann, Marcin; Wyrwicz, Lucjan S; Stepniak, Piotr; Plewczynski, Dariusz M; Lazniewski, Michal; Ginalski, Krzysztof; Rychlewski, Leszek

    2011-02-28

    Squalene epoxidase (SE) is a key flavin adenine dinucleotide (FAD)-dependent enzyme of ergosterol and cholesterol biosynthetic pathways and an attractive potential target for drugs used to inhibit the growth of pathogenic fungi or to lower cholesterol level. Although many studies on allylamine drugs activity have been published during the last 30 years, up until now no detailed mechanism of the squalene epoxidase inhibition has been presented. Our study brings such a model at atomic resolution in the case of yeast Saccharomyces cerevisiae . Presented data resulting from modeling studies are in excellent agreement with experimental findings. A fully atomic three-dimensional (3D) model of squalene epoxidase (EC 1.14.99.7) from S. cerevisiae was built with the help of 3D-Jury approach and further screened based on data known from mutation experiments leading to terbinafine resistance. Docking studies followed by molecular dynamics simulations and quantum interaction energy calculations [MP2/6-31G(d)] resulted in the identification of the terbinafine-squalene epoxidase mode of interaction. In the energetically most likely orientation of terbinafine its interaction energy with the protein is ca. 120 kJ/mol. In the favorable position the terbinafine lipophilic moiety is located vertically inside the squalene epoxidase binding pocket with the tert-butyl group oriented toward its center. Such a position results in the SE conformational changes and prevents the natural substrate from being able to bind to the enzyme's active site. That would explain the noncompetitive manner of SE inhibition. We found that the strongest interaction between terbinafine and SE stems from hydrogen bonding between hydrogen-bond donors, hydroxyl group of Tyr90 and amine nitrogen atom of terbinafine. Moreover, strong attractive interactions were recorded for amino acids whose mutations resulted in terbinafine resistance. Our results, elucidating at a molecular level the mode of terbinafine

  15. ERα inhibited myocardin-induced differentiation in uterine fibroids

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Xing-Hua, E-mail: xinghualiao@hotmail.com [Institute of Biology and Medicine, Wuhan University of Science and Technology, Wuhan, 430065 (China); Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education and Tianjin, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Li, Jun-Yan [Henan Vocational College of Applied Technology, Zhengzhou 450042 (China); Dong, Xiu-Mei [Institute of Biology and Medicine, Wuhan University of Science and Technology, Wuhan, 430065 (China); Yuncheng County People' s Hospital, Shandong 274700 (China); Wang, Xiuhong [Xianning Central Hospital, Department of Obstetrics and Gynecology, Xianning, Hubei 437100 (China); Xiang, Yuan; Li, Hui; Yu, Cheng-Xi; Li, Jia-Peng; Yuan, Bai-Yin [Institute of Biology and Medicine, Wuhan University of Science and Technology, Wuhan, 430065 (China); Zhou, Jun, E-mail: zhoujun@wust.edu.cn [Institute of Biology and Medicine, Wuhan University of Science and Technology, Wuhan, 430065 (China); School of Medicine, Wuhan University of Science and Technology, Wuhan 430065 (China); Zhang, Tong-Cun, E-mail: zhangtongcun@wust.edu.cn [Institute of Biology and Medicine, Wuhan University of Science and Technology, Wuhan, 430065 (China); Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education and Tianjin, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China)

    2017-01-01

    Uterine fibroids, also known as uterine leiomyomas, are a benign tumor of the human uterus and the commonest estrogen-dependent benign tumor found in women. Myocardin is an important transcriptional regulator in smooth and cardiac muscle development. The role of myocardin and its relationship with ERα in uterine fibroids have barely been addressed. We noticed that the expression of myocardin was markedly reduced in human uterine fibroid tissue compared with corresponding normal or adjacent myometrium tissue. Here we reported that myocardin induced the transcription and expression of differentiation markers SM22α and alpha smooth muscle actin (α-SMA) in rat primary uterine smooth muscle cells (USMCs) and this effect was inhibited by ERα. Notably, we showed that, ERα induced expression of proliferation markers PCNA and ki-67 in rat primary USMCs. We also found ERα interacted with myocardin and formed complex to bind to CArG box and inhibit the SM22α promoter activity. Furthermore, ERα inhibited the transcription and expression of myocardin, and reduced the levels of transcription and expression of downstream target SM22α, a SMC differentiation marker. Our data thus provided important and novel insights into how ERα and myocardin interact to control the cell differentiation and proliferation of USMCs. Thus, it may provide potential therapeutic target for uterine fibroids.

  16. Targeting GLI by GANT61 involves mechanisms dependent on inhibition of both transcription and DNA licensing.

    Science.gov (United States)

    Zhang, Ruowen; Wu, Jiahui; Ferrandon, Sylvain; Glowacki, Katie J; Houghton, Janet A

    2016-12-06

    The GLI genes are transcription factors and in cancers are oncogenes, aberrantly and constitutively activated. GANT61, a specific GLI inhibitor, has induced extensive cytotoxicity in human models of colon cancer. The FOXM1 promoter was determined to be a transcriptional target of GLI1. In HT29 cells, inhibition of GLI1 binding at the GLI consensus sequence by GANT61 led to inhibited binding of Pol II, the pause-release factors DSIF, NELF and p-TEFb. The formation of R-loops (RNA:DNA hybrids, ssDNA), were reduced by GANT61 at the FOXM1 promoter. Pretreatment of HT29 cells with α-amanitin reduced GANT61-induced γH2AX foci. Co-localization of GLI1 and BrdU foci, inhibited by GANT61, indicated GLI1 and DNA replication to be linked. By co-immunoprecipitation and confocal microscopy, GLI1 co-localized with the DNA licensing factors ORC4, CDT1, and MCM2. Significant co-localization of GLI1 and ORC4 was inhibited by GANT61, and enrichment of ORC4 occurred at the GLI binding site in the FOXM1 promoter. CDT1 was found to be a transcription target of GLI1. Overexpression of CDT1 in HT29 and SW480 cells reduced GANT61-induced cell death, gH2AX foci, and cleavage of caspase-3. Data demonstrate involvement of transcription and of DNA replication licensing factors by non-transcriptional and transcriptional mechanisms in the GLI-dependent mechanism of action of GANT61.

  17. Mechanisms of palmitate-induced cell death in human osteoblasts

    Science.gov (United States)

    Gunaratnam, Krishanthi; Vidal, Christopher; Boadle, Ross; Thekkedam, Chris; Duque, Gustavo

    2013-01-01

    Summary Lipotoxicity is an overload of lipids in non-adipose tissues that affects function and induces cell death. Lipotoxicity has been demonstrated in bone cells in vitro using osteoblasts and adipocytes in coculture. In this condition, lipotoxicity was induced by high levels of saturated fatty acids (mostly palmitate) secreted by cultured adipocytes acting in a paracrine manner. In the present study, we aimed to identify the underlying mechanisms of lipotoxicity in human osteoblasts. Palmitate induced autophagy in cultured osteoblasts, which was preceded by the activation of autophagosomes that surround palmitate droplets. Palmitate also induced apoptosis though the activation of the Fas/Jun kinase (JNK) apoptotic pathway. In addition, osteoblasts could be protected from lipotoxicity by inhibiting autophagy with the phosphoinositide kinase inhibitor 3-methyladenine or by inhibiting apoptosis with the JNK inhibitor SP600125. In summary, we have identified two major molecular mechanisms of lipotoxicity in osteoblasts and in doing so we have identified a new potential therapeutic approach to prevent osteoblast dysfunction and death, which are common features of age-related bone loss and osteoporosis. PMID:24285710

  18. Inhibition of the Unfolded Protein Response Mechanism Prevents Cardiac Fibrosis.

    Directory of Open Access Journals (Sweden)

    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.

  19. Molecular mechanism for inhibition of twinfilin by phosphoinositides

    DEFF Research Database (Denmark)

    Hakala, Markku; Kalimeri, Maria; Enkavi, Giray

    2018-01-01

    actin-depolymerizing factor (ADF)/cofilin-like ADF homology domains of twinfilin bind phosphoinositides only with low affinity. Mutagenesis and biochemical experiments combined with atomistic molecular dynamics simulations reveal that the C-terminal tail of twinfilin interacts with membranes through......Membrane phosphoinositides control organization and dynamics of the actin cytoskeleton by regulating the activities of several key actin-binding proteins. Twinfilin is an evolutionarily conserved protein that contributes to cytoskeletal dynamics by interacting with actin monomers, filaments......, and the heterodimeric capping protein. Twinfilin also binds phosphoinositides, which inhibit its interactions with actin, but the underlying mechanism has remained unknown. Here, we show that the high-affinity binding site of twinfilin for phosphoinositides is located at the C-terminal tail region, whereas the two...

  20. EZH2 Inhibition Ameliorates Transverse Aortic Constriction-Induced Pulmonary Arterial Hypertension in Mice

    Directory of Open Access Journals (Sweden)

    Zhan-Li Shi

    2018-01-01

    Full Text Available Background. EPZ005687 is a selective inhibiter of methyltransferase EZH2. In this article, we investigated the protective role and mechanism of EPZ005687 in transverse aortic constriction-induced pulmonary arterial hypertension in mice. Methods. We assigned 15 (6–8 weeks old male balb/c mice to 3 groups randomly: Sham control + DMSO group, TAC + DMSO group, and TAC + EPZ005687 group (10 mg kg−1, once a week for 4 weeks. On day 28 following TAC operation, the right ventricular systolic blood pressure (RVSBP was measured, and lung tissues were collected for laboratory examinations (DHE, Western blot, real-time PCR, and ChIP. Results. Murine PAH model was successfully created by TAC operation as evidenced by increased RVSBP and hypertrophic right ventricle. Compared with the sham control, TAC-induced PAH markedly upregulated the expression of EZH2 and ROS deposition in lungs in PAH mice. The inhibiter of methyltransferase EZH2, EPZ005687 significantly inhibits the development of TAC-induced PAH in an EZH2-SOD1-ROS dependent manner. Conclusion. Our data identified that EZH2 serves a fundamental role in TAC-induced PAH, and administration of EPZ005687 might represent a novel therapeutic target for the treatment of TAC-induced PAH.

  1. Molecular Mechanisms of Antipsychotic Drug-Induced Diabetes

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    Jiezhong Chen

    2017-11-01

    Full Text Available Antipsychotic drugs (APDs are widely prescribed to control various mental disorders. As mental disorders are chronic diseases, these drugs are often used over a life-time. However, APDs can cause serious glucometabolic side-effects including type 2 diabetes and hyperglycaemic emergency, leading to medication non-compliance. At present, there is no effective approach to overcome these side-effects. Understanding the mechanisms for APD-induced diabetes should be helpful in prevention and treatment of these side-effects of APDs and thus improve the clinical outcomes of APDs. In this review, the potential mechanisms for APD-induced diabetes are summarized so that novel approaches can be considered to relieve APD-induced diabetes. APD-induced diabetes could be mediated by multiple mechanisms: (1 APDs can inhibit the insulin signaling pathway in the target cells such as muscle cells, hepatocytes and adipocytes to cause insulin resistance; (2 APD-induced obesity can result in high levels of free fatty acids (FFA and inflammation, which can also cause insulin resistance. (3 APDs can cause direct damage to β-cells, leading to dysfunction and apoptosis of β-cells. A recent theory considers that both β-cell damage and insulin resistance are necessary factors for the development of diabetes. In high-fat diet-induced diabetes, the compensatory ability of β-cells is gradually damaged, while APDs cause direct β-cell damage, accounting for the severe form of APD-induced diabetes. Based on these mechanisms, effective prevention of APD-induced diabetes may need an integrated approach to combat various effects of APDs on multiple pathways.

  2. TLR2-dependent inhibition of macrophage responses to IFN-gamma is mediated by distinct, gene-specific mechanisms.

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    Sarah A Benson

    2009-07-01

    Full Text Available Mycobacterium tuberculosis uses multiple mechanisms to avoid elimination by the immune system. We have previously shown that M. tuberculosis can inhibit selected macrophage responses to IFN-gamma through TLR2-dependent and -independent mechanisms. To specifically address the role of TLR2 signaling in mediating this inhibition, we stimulated macrophages with the specific TLR2/1 ligand Pam(3CSK(4 and assayed responses to IFN-gamma. Pam(3CSK(4 stimulation prior to IFN-gamma inhibited transcription of the unrelated IFN-gamma-inducible genes, CIITA and CXCL11. Surface expression of MHC class II and secretion of CXCL11 were greatly reduced as well, indicating that the reduction in transcripts had downstream effects. Inhibition of both genes required new protein synthesis. Using chromatin immunoprecipitation, we found that TLR2 stimulation inhibited IFN-gamma-induced RNA polymerase II binding to the CIITA and CXCL11 promoters. Furthermore, TATA binding protein was unable to bind the TATA box of the CXCL11 promoter, suggesting that assembly of transcriptional machinery was disrupted. However, TLR2 stimulation affected chromatin modifications differently at each of the inhibited promoters. Histone H3 and H4 acetylation was reduced at the CIITA promoter but unaffected at the CXCL11 promoter. In addition, NF-kappaB signaling was required for inhibition of CXCL11 transcription, but not for inhibition of CIITA. Taken together, these results indicate that TLR2-dependent inhibition of IFN-gamma-induced gene expression is mediated by distinct, gene-specific mechanisms that disrupt binding of the transcriptional machinery to the promoters.

  3. Structural insights into mechanisms for inhibiting amyloid β42 aggregation by non-catechol-type flavonoids.

    Science.gov (United States)

    Hanaki, Mizuho; Murakami, Kazuma; Akagi, Ken-ichi; Irie, Kazuhiro

    2016-01-15

    The prevention of 42-mer amyloid β-protein (Aβ42) aggregation is promising for the treatment of Alzheimer's disease. We previously described the site-specific inhibitory mechanism for Aβ42 aggregation by a catechol-type flavonoid, (+)-taxifolin, targeting Lys16,28 after its autoxidation. In contrast, non-catechol-type flavonoids (morin, datiscetin, and kaempferol) inhibited Aβ42 aggregation without targeting Lys16,28 with almost similar potencies to that of (+)-taxifolin. We herein provided structural insights into their mechanisms for inhibiting Aβ42 aggregation. Physicochemical analyses revealed that their inhibition did not require autoxidation. The (1)H-(15)N SOFAST-HMQC NMR of Aβ42 in the presence of morin and datiscetin revealed the significant perturbation of chemical shifts of His13,14 and Gln15, which were close to the intermolecular β-sheet region, Gln15-Ala21. His13,14 also played a role in radical formation at Tyr10, thereby inducing the oxidation of Met35, which has been implicated in Aβ42 aggregation. These results suggest the direct interaction of morin and datiscetin with the Aβ42 monomer. Although only kaempferol was oxidatively-degraded during incubation, its degradation products as well as kaempferol itself suppressed Aβ42 aggregation. However, neither kaempferol nor its decomposed products perturbed the chemical shifts of the Aβ42 monomer. Aggregation experiments using 1,1,1,3,3,3-hexafluoro-2-propanol-treated Aβ42 demonstrated that kaempferol and its degradation products inhibited the elongation rather than nucleation phase, implying that they interacted with small aggregates of Aβ42, but not with the monomer. In contrast, morin and datiscetin inhibited both phases. The position and number of hydroxyl groups on the B-ring of non-catechol-type flavonoids could be important for their inhibitory potencies and mechanisms against Aβ42 aggregation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Molecular Mechanisms in Exercise-Induced Cardioprotection

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    Saeid Golbidi

    2011-01-01

    Full Text Available Physical inactivity is increasingly recognized as modifiable behavioral risk factor for cardiovascular diseases. A partial list of proposed mechanisms for exercise-induced cardioprotection include induction of heat shock proteins, increase in cardiac antioxidant capacity, expression of endoplasmic reticulum stress proteins, anatomical and physiological changes in the coronary arteries, changes in nitric oxide production, adaptational changes in cardiac mitochondria, increased autophagy, and improved function of sarcolemmal and/or mitochondrial ATP-sensitive potassium channels. It is currently unclear which of these protective mechanisms are essential for exercise-induced cardioprotection. However, most investigations focus on sarcolemmal KATP channels, NO production, and mitochondrial changes although it is very likely that other mechanisms may also exist. This paper discusses current information about these aforementioned topics and does not consider potentially important adaptations within blood or the autonomic nervous system. A better understanding of the molecular basis of exercise-induced cardioprotection will help to develop better therapeutic strategies.

  5. Mechanisms of chemotherapy-induced behavioral toxicities

    Directory of Open Access Journals (Sweden)

    Elisabeth G Vichaya

    2015-04-01

    Full Text Available While chemotherapeutic agents have yielded relative success in the treatment of cancer, patients are often plagued with unwanted and even debilitating side-effects from the treatment which can lead to dose reduction or even cessation of treatment. Common side effects (symptoms of chemotherapy include (i cognitive deficiencies such as problems with attention, memory and executive functioning; (ii fatigue and motivational deficit; and (iii neuropathy. These symptoms often develop during treatment but can remain even after cessation of chemotherapy, severely impacting long-term quality of life. Little is known about the underlying mechanisms responsible for the development of these behavioral toxicities, however, neuroinflammation is widely considered to be one of the major mechanisms responsible for chemotherapy-induced symptoms. Here, we critically assess what is known in regards to the role of neuroinflammation in chemotherapy-induced symptoms. We also argue that, based on the available evidence neuroinflammation is unlikely the only mechanism involved in the pathogenesis of chemotherapy-induced behavioral toxicities. We evaluate two other putative candidate mechanisms. To this end we discuss the mediating role of damage-associated molecular patterns (DAMPs activated in response to chemotherapy-induced cellular damage. We also review the literature with respect to possible alternative mechanisms such as a chemotherapy-induced change in the bioenergetic status of the tissue involving changes in mitochondrial function in relation to chemotherapy-induced behavioral toxicities. Understanding the mechanisms that underlie the emergence of fatigue, neuropathy, and cognitive difficulties is vital to better treatment and long-term survival of cancer patients.

  6. cGMP-Phosphodiesterase Inhibition Prevents Hypoxia-Induced Cell Death Activation in Porcine Retinal Explants.

    Directory of Open Access Journals (Sweden)

    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.

  7. Huperzine A prophylaxis against pentylenetetrazole-induced seizures in rats is associated with increased cortical inhibition.

    Science.gov (United States)

    Gersner, R; Ekstein, D; Dhamne, S C; Schachter, S C; Rotenberg, A

    2015-11-01

    Huperzine A (HupA) is a naturally occurring compound found in the firmoss Huperzia serrata. While HupA is a potent acetylcholinesterase inhibitor, its full pharmacologic profile is incompletely described. Since previous works suggested a capacity for HupA to prophylax against seizures, we tested the HupA antiepileptic potential in pentylenetetrazole (PTZ) rat epilepsy model and explored its mechanism of action by spectral EEG analysis and by paired-pulse transcranial magnetic stimulation (ppTMS), a measure of GABA-mediated intracortical inhibition. We tested whether HupA suppresses seizures in the rat PTZ acute seizure model, and quantified latency to first myoclonus and to generalized tonic-clonic seizure, and spike frequency on EEG. Additionally, we measured power in the EEG gamma frequency band which is associated with GABAergic cortical interneuron activation. Then, as a step toward further examining the HupA antiepileptic mechanism of action, we tested long-interval intracortical inhibition (LICI) using ppTMS coupled with electromyography to assess whether HupA augments GABA-mediated paired-pulse inhibition of the motor evoked potential. We also tested whether the HupA effect on paired-pulse inhibition was central or peripheral by comparison of outcomes following administration of HupA or the peripheral acetylcholinesterase inhibitor pyridostigmine. We also tested whether the HupA effect was dependent on central muscarinic or GABAA receptors by co-administration of HupA and atropine or PTZ, respectively. In tests of antiepileptic potential, HupA suppressed seizures and epileptic spikes on EEG. Spectral EEG analysis also revealed enhanced gamma frequency band power with HupA treatment. By ppTMS we found that HupA increases intracortical inhibition and blocks PTZ-induced cortical excitation. Atropine co-administration with HupA did not alter HupA-induced intracortical inhibition suggesting independent of muscarinic acetylcholine receptors mechanism in this model

  8. Phenylbutyrate inhibits homologous recombination induced by camptothecin and methyl methanesulfonate.

    Science.gov (United States)

    Kaiser, Gitte S; Germann, Susanne M; Westergaard, Tine; Lisby, Michael

    2011-08-01

    Homologous recombination is accompanied by extensive changes to chromatin organization at the site of DNA damage. Some of these changes are mediated through acetylation/deacetylation of histones. Here, we show that recombinational repair of DNA damage induced by the anti-cancer drug camptothecin (CPT) and the alkylating agent methyl methanesulfonate (MMS) is blocked by sodium phenylbutyrate (PBA) in the budding yeast Saccharomyces cerevisiae. In particular, PBA suppresses CPT- and MMS-induced genetic recombination as well as DNA double-strand break repair during mating-type interconversion. Treatment with PBA is accompanied by a dramatic reduction in histone H4 lysine 8 acetylation. Live cell imaging of homologous recombination proteins indicates that repair of CPT-induced DNA damage is redirected to a non-recombinogenic pathway in the presence of PBA without loss in cell viability. In contrast, the suppression of MMS-induced recombination by PBA is accompanied by a dramatic loss in cell viability. Taken together, our results demonstrate that PBA inhibits DNA damage-induced homologous recombination likely by mediating changes in chromatin acetylation. Moreover, the combination of PBA with genotoxic agents can lead to different cell fates depending on the type of DNA damage inflicted. 2011 Elsevier B.V. All rights reserved.

  9. 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

  10. PLGA-Curcumin Attenuates Opioid-Induced Hyperalgesia and Inhibits Spinal CaMKIIα

    Science.gov (United States)

    Hu, Xiaoyu; Huang, Fang; Szymusiak, Magdalena; Tian, Xuebi; Liu, Ying; Wang, Zaijie Jim

    2016-01-01

    Opioid-induced hyperalgesia (OIH) is one of the major problems associated with prolonged use of opioids for the treatment of chronic pain. Effective treatment for OIH is lacking. In this study, we examined the efficacy and preliminary mechanism of curcumin in attenuating OIH. We employed a newly developed PLGA-curcumin nanoformulation (PLGA-curcumin) in order to improve the solubility of curcumin, which has been a major obstacle in properly characterizing curcumin’s mechanism of action and efficacy. We found that curcumin administered intrathecally or orally significantly attenuated hyperalgesia in mice with morphine-induced OIH. Furthermore, we demonstrated that the effects of curcumin on OIH correlated with the suppression of chronic morphine-induced CaMKIIα activation in the superficial laminae of the spinal dorsal horn. These data suggest that PLGA-curcumin may reverse OIH possibly by inhibiting CaMKIIα and its downstream signaling. PMID:26744842

  11. PLGA-Curcumin Attenuates Opioid-Induced Hyperalgesia and Inhibits Spinal CaMKIIα.

    Directory of Open Access Journals (Sweden)

    Xiaoyu Hu

    Full Text Available Opioid-induced hyperalgesia (OIH is one of the major problems associated with prolonged use of opioids for the treatment of chronic pain. Effective treatment for OIH is lacking. In this study, we examined the efficacy and preliminary mechanism of curcumin in attenuating OIH. We employed a newly developed PLGA-curcumin nanoformulation (PLGA-curcumin in order to improve the solubility of curcumin, which has been a major obstacle in properly characterizing curcumin's mechanism of action and efficacy. We found that curcumin administered intrathecally or orally significantly attenuated hyperalgesia in mice with morphine-induced OIH. Furthermore, we demonstrated that the effects of curcumin on OIH correlated with the suppression of chronic morphine-induced CaMKIIα activation in the superficial laminae of the spinal dorsal horn. These data suggest that PLGA-curcumin may reverse OIH possibly by inhibiting CaMKIIα and its downstream signaling.

  12. TGF-β2 inhibits AKT activation and FGF-2-induced corneal endothelial cell proliferation

    International Nuclear Information System (INIS)

    Lu Jiawei; Lu Zhenyu; Reinach, Peter

    2006-01-01

    The corneal endothelial cells form a boundary layer between anterior chamber and cornea. This single cell layer is important to maintain cornea transparency by eliciting net fluid transport into the anterior chamber. Injuries of the corneal endothelial layer in humans lead to corneal swelling and translucence. This hindrance is thought to be due to limited proliferative capacity of the endothelial layer. Fibroblast growth factor 2 (FGF-2) and transforming growth factor-beta 2 (TGF-β2) are both found in aqueous humor, and these two cytokines promote and inhibit cell growth, respectively. The intracellular signaling mechanisms by which TGF-β2 suppresses the mitogenic response to FGF-2, however, remain unclear. We have addressed this question by investigating potential crosstalk between FGF-2-induced and TGF-β2-regulated intracellular signaling events in cultured bovine corneal endothelial (BCE) cells. We found that TGF-β2 and FGF-2 oppositely affect BCE cell proliferation and TGF-β2 can override the stimulating effects of FGF-2 by increasing COX-2 expression in these cells. Consistent with these findings, overexpression of COX-2 significantly reduced FGF-2-induced cell proliferation whereas a COX-2 specific inhibitor NS398 reversed the effect of TGF-β2 on FGF-2-induced cell proliferation. The COX-2 product prostaglandin E2 (PGE-2) blocks FGF-2-induced cell proliferation. Whereas FGF-2 stimulates cell proliferation by activating the AKT pathway, TGF-β2 and PGE-2 both inhibit this pathway. In accordance with the effect of PGE-2, cAMP also inhibits FGF-2-induced AKT activation. These findings suggest that the mitogenic response to FGF-2 in vivo in the corneal endothelial layer may be inhibited by TGF-β2-induced suppression of the PI3-kinase/AKT signaling pathway

  13. Catalase inhibits ionizing radiation-induced apoptosis in hematopoietic stem and progenitor cells.

    Science.gov (United States)

    Xiao, Xia; Luo, Hongmei; Vanek, Kenneth N; LaRue, Amanda C; Schulte, Bradley A; Wang, Gavin Y

    2015-06-01

    Hematologic toxicity is a major cause of mortality in radiation emergency scenarios and a primary side effect concern in patients undergoing chemo-radiotherapy. Therefore, there is a critical need for the development of novel and more effective approaches to manage this side effect. Catalase is a potent antioxidant enzyme that coverts hydrogen peroxide into hydrogen and water. In this study, we evaluated the efficacy of catalase as a protectant against ionizing radiation (IR)-induced toxicity in hematopoietic stem and progenitor cells (HSPCs). The results revealed that catalase treatment markedly inhibits IR-induced apoptosis in murine hematopoietic stem cells and hematopoietic progenitor cells. Subsequent colony-forming cell and cobble-stone area-forming cell assays showed that catalase-treated HSPCs can not only survive irradiation-induced apoptosis but also have higher clonogenic capacity, compared with vehicle-treated cells. Moreover, transplantation of catalase-treated irradiated HSPCs results in high levels of multi-lineage and long-term engraftments, whereas vehicle-treated irradiated HSPCs exhibit very limited hematopoiesis reconstituting capacity. Mechanistically, catalase treatment attenuates IR-induced DNA double-strand breaks and inhibits reactive oxygen species. Unexpectedly, we found that the radioprotective effect of catalase is associated with activation of the signal transducer and activator of transcription 3 (STAT3) signaling pathway and pharmacological inhibition of STAT3 abolishes the protective activity of catalase, suggesting that catalase may protect HSPCs against IR-induced toxicity via promoting STAT3 activation. Collectively, these results demonstrate a previously unrecognized mechanism by which catalase inhibits IR-induced DNA damage and apoptosis in HSPCs.

  14. Putting retrieval-induced forgetting in context: an inhibition-free, context-based account.

    Science.gov (United States)

    Jonker, Tanya R; Seli, Paul; MacLeod, Colin M

    2013-10-01

    We present a new theoretical account of retrieval-induced forgetting (RIF) together with new experimental evidence that fits this account and challenges the dominant inhibition account. RIF occurs when the retrieval of some material from memory produces later forgetting of related material. The inhibition account asserts that RIF is the result of an inhibition mechanism that acts during retrieval to suppress the representations of interfering competitors. This inhibition is enduring, such that the suppressed material is difficult to access on a later test and is, therefore, recalled more poorly than baseline material. Although the inhibition account is widely accepted, a growing body of research challenges its fundamental assumptions. Our alternative account of RIF instead emphasizes the role of context in remembering. According to this context account, both of 2 tenets must be met for RIF to occur: (a) A context change must occur between study and subsequent retrieval practice, and (b) the retrieval practice context must be the active context during the final test when testing practiced categories. The results of 3 experiments, which directly test the divergent predictions of the 2 accounts, support the context account but cannot be explained by the inhibition account. In an extensive discussion, we survey the literature on RIF and apply our context account to the key findings, demonstrating the explanatory power of context. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  15. Spinal mechanism of micturition reflex inhibition by naftopidil in rats.

    Science.gov (United States)

    Sugaya, Kimio; Nishijima, Saori; Kadekawa, Katsumi; Ashitomi, Katsuhiro; Ueda, Tomoyuki; Yamamoto, Hideyuki

    2014-10-29

    We investigated the spinal mechanism through which naftopidil inhibits the micturition reflex by comparing the effects of noradrenaline and naftopidil in rats. The following were investigated: the influence of oral naftopidil on plasma monoamine and amino acid levels, the distribution of oral 14C-naftopidil, the effects of intravenous (IV) or intrathecal (IT) injection of noradrenaline or naftopidil on isovolumetric bladder contractions, amino acid levels in the lumbosacral spinal cord after IT noradrenaline or naftopidil, and the effects of IT naftopidil and strychnine and/or bicuculline on isovolumetric bladder contractions. Oral naftopidil decreased the plasma adrenaline level, while it increased the serotonin and glycine levels. After oral administration, 14C-naftopidil was detected in the spinal cord and cerebrum, as well as in plasma and the prostate gland. When the bladder volume was below the threshold for isovolumetric reflex contractions, IV (0.1mg) or IT (0.1μg) noradrenaline evoked bladder contractions, but IV (1mg) or IT (0.01-1μg) naftopidil did not. When the bladder volume was above the threshold for isovolumetric reflex contractions, IV or IT noradrenaline transiently abolished bladder contractions. IT noradrenaline decreased the levels of glycine and gamma-aminobutyric acid (GABA) in the lumbosacral cord, while IT naftopidil increased the GABA level. IT strychnine and/or bicuculline blocked the inhibitory effect of IT naftopidil on bladder contractions. Naftopidil inhibits the micturition reflex by blocking α1 receptors, as well as by the activation of serotonergic, glycinergic, and GABAergic neurons in the central nervous system. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Progranulin Inhibits Human T Lymphocyte Proliferation by Inducing the Formation of Regulatory T Lymphocytes

    Directory of Open Access Journals (Sweden)

    Kyu Hwan Kwack

    2017-01-01

    Full Text Available We have examined the effect of progranulin (PGRN on human T cell proliferation and its underlying mechanism. We show that PGRN inhibits the PHA-induced multiplication of T lymphocytes. It increases the number of iTregs when T lymphocytes are activated by PHA but does not do so in the absence of PHA. PGRN-mediated inhibition of T lymphocyte proliferation, as well as the induction of iTregs, was completely reversed by a TGF-β inhibitor or a Treg inhibitor. PGRN induced TGF-β secretion in the presence of PHA whereas it did not in the absence of PHA. Our findings indicate that PGRN suppresses T lymphocyte proliferation by enhancing the formation of iTregs from activated T lymphocytes in response to TGF-β.

  17. Sensory experience regulates cortical inhibition by inducing IGF1 in VIP neurons.

    Science.gov (United States)

    Mardinly, A R; Spiegel, I; Patrizi, A; Centofante, E; Bazinet, J E; Tzeng, C P; Mandel-Brehm, C; Harmin, D A; Adesnik, H; Fagiolini, M; Greenberg, M E

    2016-03-17

    Inhibitory neurons regulate the adaptation of neural circuits to sensory experience, but the molecular mechanisms by which experience controls the connectivity between different types of inhibitory neuron to regulate cortical plasticity are largely unknown. Here we show that exposure of dark-housed mice to light induces a gene program in cortical vasoactive intestinal peptide (VIP)-expressing neurons that is markedly distinct from that induced in excitatory neurons and other subtypes of inhibitory neuron. We identify Igf1 as one of several activity-regulated genes that are specific to VIP neurons, and demonstrate that IGF1 functions cell-autonomously in VIP neurons to increase inhibitory synaptic input onto these neurons. Our findings further suggest that in cortical VIP neurons, experience-dependent gene transcription regulates visual acuity by activating the expression of IGF1, thus promoting the inhibition of disinhibitory neurons and affecting inhibition onto cortical pyramidal neurons.

  18. Prolyl oligopeptidase inhibition-induced growth arrest of human gastric cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Kanayo [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Sakaguchi, Minoru, E-mail: sakaguti@gly.oups.ac.jp [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Tanaka, Satoshi [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Yoshimoto, Tadashi [Department of Life Science, Setsunan University, 17-8 Ikeda-Nakamachi, Neyagawa, Osaka 572-8508 (Japan); Takaoka, Masanori [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan)

    2014-01-03

    Highlights: •We examined the effects of prolyl oligopeptidase (POP) inhibition on p53 null gastric cancer cell growth. •POP inhibition-induced cell growth suppression was associated with an increase in a quiescent G{sub 0} state. •POP might regulate the exit from and/or reentry into the cell cycle. -- Abstract: Prolyl oligopeptidase (POP) is a serine endopeptidase that hydrolyzes post-proline peptide bonds in peptides that are <30 amino acids in length. We recently reported that POP inhibition suppressed the growth of human neuroblastoma cells. The growth suppression was associated with pronounced G{sub 0}/G{sub 1} cell cycle arrest and increased levels of the CDK inhibitor p27{sup kip1} and the tumor suppressor p53. In this study, we investigated the mechanism of POP inhibition-induced cell growth arrest using a human gastric cancer cell line, KATO III cells, which had a p53 gene deletion. POP specific inhibitors, 3-((4-[2-(E)-styrylphenoxy]butanoyl)-L-4-hydroxyprolyl)-thiazolidine (SUAM-14746) and benzyloxycarbonyl-thioprolyl-thioprolinal, or RNAi-mediated POP knockdown inhibited the growth of KATO III cells irrespective of their p53 status. SUAM-14746-induced growth inhibition was associated with G{sub 0}/G{sub 1} cell cycle phase arrest and increased levels of p27{sup kip1} in the nuclei and the pRb2/p130 protein expression. Moreover, SUAM-14746-mediated cell cycle arrest of KATO III cells was associated with an increase in the quiescent G{sub 0} state, defined by low level staining for the proliferation marker, Ki-67. These results indicate that POP may be a positive regulator of cell cycle progression by regulating the exit from and/or reentry into the cell cycle by KATO III cells.

  19. Autophagy and gap junctional intercellular communication inhibition are involved in cadmium-induced apoptosis in rat liver cells

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Hui [College of Veterinary Medicine, Yangzhou University, and Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, 225009 (China); Zhuo, Liling [College of Life Science, Zaozhuang University, Zaozhuang, Shandong, 277160 (China); Han, Tao; Hu, Di; Yang, Xiaokang; Wang, Yi; Yuan, Yan; Gu, Jianhong; Bian, Jianchun; Liu, Xuezhong [College of Veterinary Medicine, Yangzhou University, and Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, 225009 (China); Liu, Zongping, E-mail: liuzongping@yzu.edu.cn [College of Veterinary Medicine, Yangzhou University, and Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, 225009 (China)

    2015-04-17

    Cadmium (Cd) is known to induce hepatotoxicity, yet the underlying mechanism of how this occurs is not fully understood. In this study, Cd-induced apoptosis was demonstrated in rat liver cells (BRL 3A) with apoptotic nuclear morphological changes and a decrease in cell index (CI) in a time- and concentration-dependent manner. The role of gap junctional intercellular communication (GJIC) and autophagy in Cd-induced apoptosis was investigated. Cd significantly induced GJIC inhibition as well as downregulation of connexin 43 (Cx43). The prototypical gap junction blocker carbenoxolone disodium (CBX) exacerbated the Cd-induced decrease in CI. Cd treatment was also found to cause autophagy, with an increase in mRNA expression of autophagy-related genes Atg-5, Atg-7, Beclin-1, and microtubule-associated protein light chain 3 (LC3) conversion from cytosolic LC3-I to membrane-bound LC3-II. The autophagic inducer rapamycin (RAP) prevented the Cd-induced CI decrease, while the autophagic inhibitor chloroquine (CQ) caused a further reduction in CI. In addition, CBX promoted Cd-induced autophagy, as well as changes in expression of Atg-5, Atg-7, Beclin-1 and LC3. CQ was found to block the Cd-induced decrease in Cx43 and GJIC inhibition, whereas RAP had opposite effect. These results demonstrate that autophagy plays a protective role during Cd-induced apoptosis in BRL 3A cells during 6 h of experiment, while autophagy exacerbates Cd-induced GJIC inhibition which has a negative effect on cellular fate. - Highlights: • GJIC and autophagy is crucial for biological processes. • Cd exposure causes GJIC inhibition and autophagy increase in BRL 3A cells. • Autophagy protects Cd induced BRL 3A cells apoptosis at an early stage. • Autophagy exacerbates Cd-induced GJIC inhibition. • GJIC plays an important role in autophagy induced cell death or survival.

  20. Roxithromycin inhibits VEGF-induced human airway smooth muscle cell proliferation: Opportunities for the treatment of asthma

    International Nuclear Information System (INIS)

    Pei, Qing-Mei; Jiang, Ping; Yang, Min; Qian, Xue-Jiao; Liu, Jiang-Bo; Kim, Sung-Ho

    2016-01-01

    Asthma is a chronic respiratory disease characterized by reversible airway obstruction with persistent airway inflammation and airway remodelling, which is associated with increased airway smooth muscle (ASM) mass. Roxithromycin (RXM) has been widely used in asthma treatment; however, its mechanism of action is poorly understood. Vascular endothelial growth factor (VEGF) has been implicated in inflammatory and airway blood vessel remodelling in patients with asthma, and shown to promote ASM cell proliferation. Here, we investigated the effect of RXM on VEGF-induced ASM cell proliferation and attempted to elucidate the underlying mechanisms of action. We tested the effect of RXM on proliferation and cell cycle progression, as well as on the expression of phospho-VEGF receptor 2 (VEGFR2), phospho-extracellular signal-regulated kinase 1/2 (ERK1/2), phospho-Akt, and caveolin-1 in VEGF-stimulated ASM cells. RXM inhibited VEGF-induced ASM cell proliferation and induced cell cycle arrest. Additionally, VEGF-induced ASM cell proliferation was suppressed by inhibiting the activity of ERK1/2, but not that of Akt. Furthermore, RXM treatment inhibits VEGF-induced activation of VEGFR2 and ERK and downregulation of caveolin-1 in a dose-dependent manner. RXM also inhibited TGF-β-induced VEGF secretion by ASM cells and BEAS-2B cells. Collectively, our findings suggest that RXM inhibits VEGF-induced ASM cell proliferation by suppression of VEGFR2 and ERK1/2 activation and caveolin-1 down-regulation, which may be involved in airway remodelling. Further elucidation of the mechanisms underlying these observations should enable the development of treatments for smooth muscle hyperplasia-associated diseases of the airway such as asthma. - Highlights: • RXM inhibited VEGF-induced ASM cell proliferation and induced cell cycle arrest. • VEGF-induced cell proliferation was suppressed by inhibiting the activity of ERK1/2. • RXM inhibits activation of VEGFR2 and ERK and downregulation

  1. Roxithromycin inhibits VEGF-induced human airway smooth muscle cell proliferation: Opportunities for the treatment of asthma

    Energy Technology Data Exchange (ETDEWEB)

    Pei, Qing-Mei, E-mail: 34713316@qq.com [Department of Radiology, Tianjin Hospital of Integrated Traditional Chinese and Western Medicine, Tianjin (China); Jiang, Ping, E-mail: jiangping@163.com [Department of Respiration, Tianjin First Central Hospital, Tianjin (China); Yang, Min, E-mail: YangMin@163.com [Department of Respiration, Tianjin First Central Hospital, Tianjin (China); Qian, Xue-Jiao, E-mail: qianxuejiao@163.com [Department of Respiration, Tianjin First Central Hospital, Tianjin (China); Liu, Jiang-Bo, E-mail: LJB1984@163.com [Department of Respiration, Tianjin First Central Hospital, Tianjin (China); Kim, Sung-Ho, E-mail: chenghao0726@hotmail.com [Department of Respiration, Tianjin First Central Hospital, Tianjin (China)

    2016-10-01

    Asthma is a chronic respiratory disease characterized by reversible airway obstruction with persistent airway inflammation and airway remodelling, which is associated with increased airway smooth muscle (ASM) mass. Roxithromycin (RXM) has been widely used in asthma treatment; however, its mechanism of action is poorly understood. Vascular endothelial growth factor (VEGF) has been implicated in inflammatory and airway blood vessel remodelling in patients with asthma, and shown to promote ASM cell proliferation. Here, we investigated the effect of RXM on VEGF-induced ASM cell proliferation and attempted to elucidate the underlying mechanisms of action. We tested the effect of RXM on proliferation and cell cycle progression, as well as on the expression of phospho-VEGF receptor 2 (VEGFR2), phospho-extracellular signal-regulated kinase 1/2 (ERK1/2), phospho-Akt, and caveolin-1 in VEGF-stimulated ASM cells. RXM inhibited VEGF-induced ASM cell proliferation and induced cell cycle arrest. Additionally, VEGF-induced ASM cell proliferation was suppressed by inhibiting the activity of ERK1/2, but not that of Akt. Furthermore, RXM treatment inhibits VEGF-induced activation of VEGFR2 and ERK and downregulation of caveolin-1 in a dose-dependent manner. RXM also inhibited TGF-β-induced VEGF secretion by ASM cells and BEAS-2B cells. Collectively, our findings suggest that RXM inhibits VEGF-induced ASM cell proliferation by suppression of VEGFR2 and ERK1/2 activation and caveolin-1 down-regulation, which may be involved in airway remodelling. Further elucidation of the mechanisms underlying these observations should enable the development of treatments for smooth muscle hyperplasia-associated diseases of the airway such as asthma. - Highlights: • RXM inhibited VEGF-induced ASM cell proliferation and induced cell cycle arrest. • VEGF-induced cell proliferation was suppressed by inhibiting the activity of ERK1/2. • RXM inhibits activation of VEGFR2 and ERK and downregulation

  2. Raddeanin A induces human gastric cancer cells apoptosis and inhibits their invasion in vitro

    International Nuclear Information System (INIS)

    Xue, Gang; Zou, Xi; Zhou, Jin-Yong; Sun, Wei; Wu, Jian; Xu, Jia-Li; Wang, Rui-Ping

    2013-01-01

    Highlights: •Raddeanin A is a triterpenoid saponin in herb medicine Anemone raddeana Regel. •Raddeanin A can inhibit 3 kinds of gastric cancer cells’ proliferation and invasion. •Caspase-cascades’ activation indicates apoptosis induced by Raddeanin A. •MMPs, RECK, Rhoc and E-cad are involved in Raddeanin A-induced invasion inhibition. -- Abstract: Raddeanin A is one of the triterpenoid saponins in herbal medicine Anemone raddeana Regel which was reported to suppress the growth of liver and lung cancer cells. However, little was known about its effect on gastric cancer (GC) cells. This study aimed to investigate its inhibitory effect on three kinds of different differentiation stage GC cells (BGC-823, SGC-7901 and MKN-28) in vitro and the possible mechanisms. Proliferation assay and flow cytometry demonstrated Raddeanin A’s dose-dependent inhibitory effect and determined its induction of cells apoptosis, respectively. Transwell assay, wounding heal assay and cell matrix adhesion assay showed that Raddeanin A significantly inhibited the abilities of the invasion, migration and adhesion of the BGC-823 cells. Moreover, quantitative real time PCR and Western blot analysis found that Raddeanin A increased Bax expression while reduced Bcl-2, Bcl-xL and Survivin expressions and significantly activated caspase-3, caspase-8, caspase-9 and poly-ADP ribose polymerase (PARP). Besides, Raddeanin A could also up-regulate the expression of reversion inducing cysteine rich protein with Kazal motifs (RECK), E-cadherin (E-cad) and down-regulate the expression of matrix metalloproteinases-2 (MMP-2), MMP-9, MMP-14 and Rhoc. In conclusion, Raddeanin A inhibits proliferation of human GC cells, induces their apoptosis and inhibits the abilities of invasion, migration and adhesion, exhibiting potential to become antitumor drug

  3. Raddeanin A induces human gastric cancer cells apoptosis and inhibits their invasion in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Gang [Department of Oncology, Nanjing University of Chinese Medicine, Nanjing (China); Zou, Xi [Department of Oncology, Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing (China); Zhou, Jin-Yong [Laboratory Center, Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing (China); Sun, Wei [Department of Oncology, Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing (China); Wu, Jian [Laboratory Center, Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing (China); Xu, Jia-Li [Department of Oncology, Nanjing University of Chinese Medicine, Nanjing (China); Wang, Rui-Ping, E-mail: ruipingwang61@hotmail.com [Department of Oncology, Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing (China)

    2013-09-20

    Highlights: •Raddeanin A is a triterpenoid saponin in herb medicine Anemone raddeana Regel. •Raddeanin A can inhibit 3 kinds of gastric cancer cells’ proliferation and invasion. •Caspase-cascades’ activation indicates apoptosis induced by Raddeanin A. •MMPs, RECK, Rhoc and E-cad are involved in Raddeanin A-induced invasion inhibition. -- Abstract: Raddeanin A is one of the triterpenoid saponins in herbal medicine Anemone raddeana Regel which was reported to suppress the growth of liver and lung cancer cells. However, little was known about its effect on gastric cancer (GC) cells. This study aimed to investigate its inhibitory effect on three kinds of different differentiation stage GC cells (BGC-823, SGC-7901 and MKN-28) in vitro and the possible mechanisms. Proliferation assay and flow cytometry demonstrated Raddeanin A’s dose-dependent inhibitory effect and determined its induction of cells apoptosis, respectively. Transwell assay, wounding heal assay and cell matrix adhesion assay showed that Raddeanin A significantly inhibited the abilities of the invasion, migration and adhesion of the BGC-823 cells. Moreover, quantitative real time PCR and Western blot analysis found that Raddeanin A increased Bax expression while reduced Bcl-2, Bcl-xL and Survivin expressions and significantly activated caspase-3, caspase-8, caspase-9 and poly-ADP ribose polymerase (PARP). Besides, Raddeanin A could also up-regulate the expression of reversion inducing cysteine rich protein with Kazal motifs (RECK), E-cadherin (E-cad) and down-regulate the expression of matrix metalloproteinases-2 (MMP-2), MMP-9, MMP-14 and Rhoc. In conclusion, Raddeanin A inhibits proliferation of human GC cells, induces their apoptosis and inhibits the abilities of invasion, migration and adhesion, exhibiting potential to become antitumor drug.

  4. Thiamine Deficiency Induces Anorexia by Inhibiting Hypothalamic AMPK

    Science.gov (United States)

    Liu, Mei; Alimov, Alexander; Wang, Haiping; Frank, Jacqueline A.; Katz, Wendy; Xu, Mei; Ke, Zun-Ji; Luo, Jia

    2014-01-01

    Obesity and eating disorders are prevailing health concerns worldwide. It is important to understand the regulation of food intake and energy metabolism. Thiamine (vitamin B1) is an essential nutrient. Thiamine deficiency (TD) can cause a number of disorders in humans, such as Beriberi and Wernicke-Korsakoff syndrome. We demonstrated here that TD caused anorexia in C57BL/6 mice. After feeding a TD diet for 16 days, the mice displayed a significant decrease in food intake and an increase in resting energy expenditure (REE), which resulted in a severe weight loss. At the 22nd day, the food intake was reduced by 69% and 74% for male and female mice, respectively in TD group. The REE increased by 9 folds in TD group. The loss of body weight (17–24%) was similar between male and female animals and mainly resulted from the reduction of fat mass (49% decrease). Re-supplementation of thiamine (benfotiamine) restored animal's appetite, leading to a total recovery of body weight. The hypothalamic AMPK is a critical regulator of food intake. TD inhibited the phosphorylation of AMPK in the arcuate nucleus (ARN) and paraventricular nucleus (PVN) of the hypothalamus without affecting its expression. TD-induced inhibition of AMPK phosphorylation was reversed once thiamine was re-supplemented. In contrast, TD increased AMPK phosphorylation in the skeletal muscle and upregulated the uncoupling protein (UCP)-1 in brown adipose tissues which was consistent with increased basal energy expenditure. Re-administration of thiamine stabilized AMPK phosphorylation in the skeletal muscle as well as energy expenditure. Taken together, TD may induce anorexia by inhibiting hypothalamic AMPK activity. With a simultaneous increase in energy expenditure, TD caused an overall body weight loss. The results suggest that the status of thiamine levels in the body may affect food intake and body weight. PMID:24607345

  5. Mechanisms of transient radiation-induced creep

    International Nuclear Information System (INIS)

    Pyatiletov, Yu.S.

    1981-01-01

    Radiation-induced creep at the transient stage is investigated for metals. The situation, when several possible creep mechanisms operate simultaneously is studied. Among them revealed are those which give the main contribution and determine thereby the creep behaviour. The time dependence of creep rate and its relation to the smelling rate is obtained. The results satisfactorily agree with the available experimental data [ru

  6. Ginger extract inhibits LPS induced macrophage activation and function

    Directory of Open Access Journals (Sweden)

    Bruch David

    2008-01-01

    Full Text Available Abstract Background Macrophages play a dual role in host defence. They act as the first line of defence by mounting an inflammatory response to antigen exposure and also act as antigen presenting cells and initiate the adaptive immune response. They are also the primary infiltrating cells at the site of inflammation. Inhibition of macrophage activation is one of the possible approaches towards modulating inflammation. Both conventional and alternative approaches are being studied in this regard. Ginger, an herbal product with broad anti inflammatory actions, is used as an alternative medicine in a number of inflammatory conditions like rheumatic disorders. In the present study we examined the effect of ginger extract on macrophage activation in the presence of LPS stimulation. Methods Murine peritoneal macrophages were stimulated by LPS in presence or absence of ginger extract and production of proinflammatory cytokines and chemokines were observed. We also studied the effect of ginger extract on the LPS induced expression of MHC II, B7.1, B7.2 and CD40 molecules. We also studied the antigen presenting function of ginger extract treated macrophages by primary mixed lymphocyte reaction. Results We observed that ginger extract inhibited IL-12, TNF-α, IL-1β (pro inflammatory cytokines and RANTES, MCP-1 (pro inflammatory chemokines production in LPS stimulated macrophages. Ginger extract also down regulated the expression of B7.1, B7.2 and MHC class II molecules. In addition ginger extract negatively affected the antigen presenting function of macrophages and we observed a significant reduction in T cell proliferation in response to allostimulation, when ginger extract treated macrophages were used as APCs. A significant decrease in IFN-γ and IL-2 production by T cells in response to allostimulation was also observed. Conclusion In conclusion ginger extract inhibits macrophage activation and APC function and indirectly inhibits T cell activation.

  7. Mechanism of HERG potassium channel inhibition by tetra-n-octylammonium bromide and benzethonium chloride

    International Nuclear Information System (INIS)

    Long, Yan; Lin, Zuoxian; Xia, Menghang; Zheng, Wei; Li, Zhiyuan

    2013-01-01

    Tetra-n-octylammonium bromide and benzethonium chloride are synthetic quaternary ammonium salts that are widely used in hospitals and industries for the disinfection and surface treatment and as the preservative agent. Recently, the activities of HERG channel inhibition by these compounds have been found to have potential risks to induce the long QT syndrome and cardiac arrhythmia, although the mechanism of action is still elusive. This study was conducted to investigate the mechanism of HERG channel inhibition by these compounds by using whole-cell patch clamp experiments in a CHO cell line stably expressing HERG channels. Tetra-n-octylammonium bromide and benzethonium chloride exhibited concentration-dependent inhibitions of HERG channel currents with IC 50 values of 4 nM and 17 nM, respectively, which were also voltage-dependent and use-dependent. Both compounds shifted the channel activation I–V curves in a hyperpolarized direction for 10–15 mV and accelerated channel activation and inactivation processes by 2-fold. In addition, tetra-n-octylammonium bromide shifted the inactivation I–V curve in a hyperpolarized direction for 24.4 mV and slowed the rate of channel deactivation by 2-fold, whereas benzethonium chloride did not. The results indicate that tetra-n-octylammonium bromide and benzethonium chloride are open-channel blockers that inhibit HERG channels in the voltage-dependent, use-dependent and state-dependent manners. - Highlights: ► Tetra-n-octylammonium and benzethonium are potent HERG channel inhibitors. ► Channel activation and inactivation processes are accelerated by the two compounds. ► Both compounds are the open-channel blockers to HERG channels. ► HERG channel inhibition by both compounds is use-, voltage- and state dependent. ► The in vivo risk of QT prolongation needs to be studied for the two compounds

  8. Mechanism of HERG potassium channel inhibition by tetra-n-octylammonium bromide and benzethonium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Long, Yan; Lin, Zuoxian [Key Laboratory of Regenerative Biology, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530 (China); Xia, Menghang; Zheng, Wei [National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20892 (United States); Li, Zhiyuan, E-mail: li_zhiyuan@gibh.ac.cn [Key Laboratory of Regenerative Biology, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530 (China)

    2013-03-01

    Tetra-n-octylammonium bromide and benzethonium chloride are synthetic quaternary ammonium salts that are widely used in hospitals and industries for the disinfection and surface treatment and as the preservative agent. Recently, the activities of HERG channel inhibition by these compounds have been found to have potential risks to induce the long QT syndrome and cardiac arrhythmia, although the mechanism of action is still elusive. This study was conducted to investigate the mechanism of HERG channel inhibition by these compounds by using whole-cell patch clamp experiments in a CHO cell line stably expressing HERG channels. Tetra-n-octylammonium bromide and benzethonium chloride exhibited concentration-dependent inhibitions of HERG channel currents with IC{sub 50} values of 4 nM and 17 nM, respectively, which were also voltage-dependent and use-dependent. Both compounds shifted the channel activation I–V curves in a hyperpolarized direction for 10–15 mV and accelerated channel activation and inactivation processes by 2-fold. In addition, tetra-n-octylammonium bromide shifted the inactivation I–V curve in a hyperpolarized direction for 24.4 mV and slowed the rate of channel deactivation by 2-fold, whereas benzethonium chloride did not. The results indicate that tetra-n-octylammonium bromide and benzethonium chloride are open-channel blockers that inhibit HERG channels in the voltage-dependent, use-dependent and state-dependent manners. - Highlights: ► Tetra-n-octylammonium and benzethonium are potent HERG channel inhibitors. ► Channel activation and inactivation processes are accelerated by the two compounds. ► Both compounds are the open-channel blockers to HERG channels. ► HERG channel inhibition by both compounds is use-, voltage- and state dependent. ► The in vivo risk of QT prolongation needs to be studied for the two compounds.

  9. Stat3 inhibition attenuates mechanical allodynia through transcriptional regulation of chemokine expression in spinal astrocytes.

    Directory of Open Access Journals (Sweden)

    Xiaodong Liu

    Full Text Available BACKGROUND: Signal transducer and activator of transcription 3 (Stat3 is known to induce cell proliferation and inflammation by regulating gene transcription. Recent studies showed that Stat3 modulates nociceptive transmission by reducing spinal astrocyte proliferation. However, it is unclear whether Stat3 also contributes to the modulation of nociceptive transmission by regulating inflammatory response in spinal astrocytes. This study aimed at investigating the role of Stat3 on neuroinflammation during development of pain in rats after intrathecal injection of lipopolysaccharide (LPS. METHODS: Stat3 specific siRNA oligo and synthetic selective inhibitor (Stattic were applied to block the activity of Stat3 in primary astrocytes or rat spinal cord, respectively. LPS was used to induce the expression of proinflammatory genes in all studies. Immunofluorescence staining of cells and slices of spinal cord was performed to monitor Stat3 activation. The impact of Stat3 inhibition on proinflammatory genes expression was determined by cytokine antibody array, enzyme-linked immunosorbent assay and real-time polymerase chain reaction. Mechanical allodynia, as determined by the threshold pressure that could induce hind paw withdrawal after application of standardized von Frey filaments, was used to detect the effects of Stat3 inhibition after pain development with intrathecal LPS injection. RESULTS: Intrathecal injection of LPS activated Stat3 in reactive spinal astrocytes. Blockade of Stat3 activity attenuated mechanical allodynia significantly and was correlated with a lower number of reactive astrocytes in the spinal dorsal horn. In vitro study demonstrated that Stat3 modulated inflammatory response in primary astrocytes by transcriptional regulation of chemokine expression including Cx3cl1, Cxcl5, Cxcl10 and Ccl20. Similarly, inhibition of Stat3 reversed the expression of these chemokines in the spinal dorsal horn. CONCLUSIONS: Stat3 acted as a

  10. PPARγ ligand ciglitazone inhibits TNFα-induced ICAM-1 in human airway smooth muscle cells

    Directory of Open Access Journals (Sweden)

    Chien-Da Huang

    2014-08-01

    Full Text Available Background: Modification of human airway smooth muscle (ASM function by proinflammatory cytokines has been regarded as a potential mechanism underlying bronchial hyperresponsiveness in asthma. Human ASM cells express intercellular adhesion molecule (ICAM-1 in response to cytokines. Synthetic ligands for peroxisome proliferator-activated receptor (PPARγ reportedly possess anti-inflammatory and immunomodulatory properties. In this study, we examined whether ciglitazone, a synthetic PPARγ ligand, can modulate the basal and tumor necrosis factor (TNFα-induced ICAM1 gene expression in human ASM cells. Methods: Human ASM cells were treated with TNFα. ICAM-1 expression was assessed by flow cytometry and reverse transcriptase-polymerase chain reaction (RT-PCR analysis. PPARγ activity was inhibited by target-specific small interfering (si RNA targeting PPARγ and GW9662, a PPARγ antagonist. Activity of nuclear factor (NF-κB was assessed by using immunoblot analysis, immune-confocal images, and electrophoretic mobility shift assay (EMSA. Results: By flow cytometry, ciglitazone alone had no effect on ICAM-1 expression in ASM cells, but inhibited ICAM-1 expression in response to TNFα (10 ng/ml in a dose-dependent manner (1-10 μM. It also inhibited TNFα-induced ICAM1 gene expression by RT-PCR analysis. Knockdown of PPARγ gene by target-specific siRNA targeting PPARγ enhanced ICAM-1 expression and the inhibitory effect of ciglitazone on TNFα-induced ICAM-1 expression was reversed by PPARγ siRNA and GW9662. SN-50 (10 μg/ml, an inhibitor for nuclear translocation of NF-κB, inhibited TNFα-induced ICAM-1 expression. Ciglitazone did not prevent TNFα-induced degradation of the cytosolic inhibitor of NF-κB (IκB, but inhibited the nuclear translocation of p65 induced by TNFα and suppressed the NF-κB/DNA binding activity. Conclusion: These findings suggest that ciglitazone inhibits TNFα-induced ICAM1 gene expression in human ASM cells through

  11. Clonal cell populations unresponsive to radiosensitization induced by telomerase inhibition

    International Nuclear Information System (INIS)

    Ju, Yeun-Jin; Shin, Hyun-Jin; Park, Jeong-Eun; Juhn, Kyoung-Mi; Woo, Seon Rang; Kim, Hee-Young; Han, Young-Hoon; Hwang, Sang-Gu; Hong, Sung-Hee; Kang, Chang-Mo; Yoo, Young-Do; Park, Won-Bong; Cho, Myung-Haing; Park, Gil Hong; Lee, Kee-Ho

    2010-01-01

    Research highlights: → In our present manuscript, we have clearly showed an interesting but problematic obstacle of a radiosensitization strategy based on telomerase inhibition by showing that: Clonal population unresponsive to this radiosensitization occasionally arise. → The telomere length of unsensitized clones was reduced, as was that of most sensitized clones. → The unsensitized clones did not show chromosome end fusion which was noted in all sensitized clones. → P53 status is not associated with the occurrence of unsensitized clone. → Telomere end capping in unsensitized clone is operative even under telomerase deficiency. -- Abstract: A combination of a radiotherapeutic regimen with telomerase inhibition is valuable when tumor cells are to be sensitized to radiation. Here, we describe cell clones unresponsive to radiosensitization after telomere shortening. After extensive division of individual transformed clones of mTERC -/- cells, about 22% of clones were unresponsive to radiosensitization even though telomerase action was inhibited. The telomere lengths of unsensitized mTERC -/- clones were reduced, as were those of most sensitized clones. However, the unsensitized clones did not exhibit chromosomal end-to-end fusion to the extent noted in all sensitized clones. Thus, a defense mechanism preventing telomere erosion is operative even when telomeres become shorter under conditions of telomerase deficiency, and results in unresponsiveness to the radiosensitization generally mediated by telomere shortening.

  12. Bean grain hysteresis with induced mechanical damage

    Directory of Open Access Journals (Sweden)

    Renata C. Campos

    Full Text Available ABSTRACT This study aimed to evaluate the effect of mechanical damage on the hysteresis of beans with induced mechanical damage under different conditions of temperature and relative humidity. Beans (Phaseolus vulgaris L. harvested manually with 35% water content (w.b. were used. Part of this product was subjected to induced mechanical damage by Stein Breakage Tester and controlled drying (damaged and control sample, for sorption processes. The sorption isotherms of water were analyzed for different temperature conditions: 20, 30, 40 and 50 oC; and relative humidity: 0.3; 0.4; 0.5; 0.7 and 0.9 (decimal. Equilibrium moisture content data were correlated with six mathematical models, and the Modified Oswin model was the one that best fitted to the experimental data. According to the above mentioned isotherms, it was possible to observe the phenomenon of hysteresis of damaged and control samples, and this phenomenon was more pronounced in control ones.

  13. Echinocystic acid inhibits RANKL-induced osteoclastogenesis by regulating NF-κB and ERK signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jian-hui, E-mail: jianhui_yangxa@163.com [Rehabilitation Center, First Affiliated Hospital of Health Science Center, Xi’an Jiaotong University, Xi’an, 710061, Shaanxi Province (China); Li, Bing [Department of Dermatology, the 451st Hospital of People’s Liberation Army, Xi’an 710054, Shaanxi Province (China); Wu, Qiong; Lv, Jian-guo; Nie, Hui-Yong [Rehabilitation Center, First Affiliated Hospital of Health Science Center, Xi’an Jiaotong University, Xi’an, 710061, Shaanxi Province (China)

    2016-09-02

    Receptor activator of nuclear factor-κB ligand (RANKL) is a key factor in the differentiation and activation of osteoclasts. Echinocystic acid (EA), a pentacyclic triterpene isolated from the fruits of Gleditsia sinensis Lam, was reported to prevent reduction of bone mass and strength and improve the cancellous bone structure and biochemical properties in ovariectomy rats. However, the molecular mechanism of EA on the osteoclast formation has not been reported. The purpose of this study was to investigate the effects and mechanism of EA on RANKL-induced osteoclastogenesis. Our results showed that EA inhibited the formation of osteoclast, as well as the expression of osteoclastogenesis-related marker proteins in bone marrow macrophages (BMMs). At molecular levels, EA inhibited RANKL-induced NF-κB activation and ERK phosphorylation in BMMs. In conclusion, the present study demonstrated that EA can suppress osteoclastogenesis in vitro. Moreover, we clarified that these inhibitory effects of EA occur through suppression of NF-κB and ERK activation. Therefore, EA may be a potential agent in the treatment of osteoclast-related diseases such as osteoporosis. - Highlights: • EA inhibited the formation of osteoclast in BMMs. • EA inhibits the expression of osteoclastogenesis-related marker proteins in BMMs. • EA inhibits RANKL-induced NF-κB activation in BMMs. • EA inhibits RANKL-induced ERK phosphorylation in BMMs.

  14. Viewing loved faces inhibits defense reactions: a health-promotion mechanism?

    Directory of Open Access Journals (Sweden)

    Pedro Guerra

    Full Text Available We have known for decades that social support is associated with positive health outcomes. And yet, the neurophysiological mechanisms underlying this association remain poorly understood. The link between social support and positive health outcomes is likely to depend on the neurophysiological regulatory mechanisms underlying reward and defensive reactions. The present study examines the hypothesis that emotional social support (love provides safety cues that activate the appetitive reward system and simultaneously inhibit defense reactions. Using the startle probe paradigm, 54 undergraduate students (24 men viewed black and white photographs of loved (romantic partner, father, mother, and best friend, neutral (unknown, and unpleasant (mutilated faces. Eye-blink startle, zygomatic major activity, heart rate, and skin conductance responses to the faces, together with subjective ratings of valence, arousal, and dominance, were obtained. Viewing loved faces induced a marked inhibition of the eye-blink startle response accompanied by a pattern of zygomatic, heart rate, skin conductance, and subjective changes indicative of an intense positive emotional response. Effects were similar for men and women, but the startle inhibition and the zygomatic response were larger in female participants. A comparison between the faces of the romantic partner and the parent who shares the partner's gender further suggests that this effect is not attributable to familiarity or arousal. We conclude that this inhibitory capacity may contribute to the health benefits associated with social support.

  15. Viewing loved faces inhibits defense reactions: a health-promotion mechanism?

    Science.gov (United States)

    Guerra, Pedro; Sánchez-Adam, Alicia; Anllo-Vento, Lourdes; Ramírez, Isabel; Vila, Jaime

    2012-01-01

    We have known for decades that social support is associated with positive health outcomes. And yet, the neurophysiological mechanisms underlying this association remain poorly understood. The link between social support and positive health outcomes is likely to depend on the neurophysiological regulatory mechanisms underlying reward and defensive reactions. The present study examines the hypothesis that emotional social support (love) provides safety cues that activate the appetitive reward system and simultaneously inhibit defense reactions. Using the startle probe paradigm, 54 undergraduate students (24 men) viewed black and white photographs of loved (romantic partner, father, mother, and best friend), neutral (unknown), and unpleasant (mutilated) faces. Eye-blink startle, zygomatic major activity, heart rate, and skin conductance responses to the faces, together with subjective ratings of valence, arousal, and dominance, were obtained. Viewing loved faces induced a marked inhibition of the eye-blink startle response accompanied by a pattern of zygomatic, heart rate, skin conductance, and subjective changes indicative of an intense positive emotional response. Effects were similar for men and women, but the startle inhibition and the zygomatic response were larger in female participants. A comparison between the faces of the romantic partner and the parent who shares the partner's gender further suggests that this effect is not attributable to familiarity or arousal. We conclude that this inhibitory capacity may contribute to the health benefits associated with social support.

  16. 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

  17. Inhibition of PKR protects against H2O2-induced injury on neonatal cardiac myocytes by attenuating apoptosis and inflammation.

    Science.gov (United States)

    Wang, Yongyi; Men, Min; Xie, Bo; Shan, Jianggui; Wang, Chengxi; Liu, Jidong; Zheng, Hui; Yang, Wengang; Xue, Song; Guo, Changfa

    2016-12-08

    Reactive oxygenation species (ROS) generated from reperfusion results in cardiac injury through apoptosis and inflammation, while PKR has the ability to promote apoptosis and inflammation. The aim of the study was to investigate whether PKR is involved in hydrogen peroxide (H 2 O 2 ) induced neonatal cardiac myocytes (NCM) injury. In our study, NCM, when exposed to H 2 O 2 , resulted in persistent activation of PKR due to NCM endogenous RNA. Inhibition of PKR by 2-aminopurine (2-AP) or siRNA protected against H 2 O 2 induced apoptosis and injury. To elucidate the mechanism, we revealed that inhibition of PKR alleviated H 2 O 2 induced apoptosis companied by decreased caspase3/7 activity, BAX and caspase-3 expression. We also revealed that inhibition of PKR suppressed H 2 O 2 induced NFκB pathway and NLRP3 activation. Finally, we found ADAR1 mRNA and protein expression were both induced after H 2 O 2 treatment through STAT-2 dependent pathway. By gain and loss of ADAR1 expression, we confirmed ADAR1 modulated PKR activity. Therefore, we concluded inhibition of PKR protected against H 2 O 2 -induced injury by attenuating apoptosis and inflammation. A self-preservation mechanism existed in NCM that ADAR1 expression is induced by H 2 O 2 to limit PKR activation simultaneously. These findings identify a novel role for PKR/ADAR1 in myocardial reperfusion injury.

  18. Mechanism of Action and Inhibition of dehydrosqualene Synthase

    Energy Technology Data Exchange (ETDEWEB)

    F Lin; C Liu; Y Liu; Y Zhang; K Wang; W Jeng; T Ko; R Cao; A Wang; E Oldfield

    2011-12-31

    'Head-to-head' terpene synthases catalyze the first committed steps in sterol and carotenoid biosynthesis: the condensation of two isoprenoid diphosphates to form cyclopropylcarbinyl diphosphates, followed by ring opening. Here, we report the structures of Staphylococcus aureus dehydrosqualene synthase (CrtM) complexed with its reaction intermediate, presqualene diphosphate (PSPP), the dehydrosqualene (DHS) product, as well as a series of inhibitors. The results indicate that, on initial diphosphate loss, the primary carbocation so formed bends down into the interior of the protein to react with C2,3 double bond in the prenyl acceptor to form PSPP, with the lower two-thirds of both PSPP chains occupying essentially the same positions as found in the two farnesyl chains in the substrates. The second-half reaction is then initiated by the PSPP diphosphate returning back to the Mg{sup 2+} cluster for ionization, with the resultant DHS so formed being trapped in a surface pocket. This mechanism is supported by the observation that cationic inhibitors (of interest as antiinfectives) bind with their positive charge located in the same region as the cyclopropyl carbinyl group; that S-thiolo-diphosphates only inhibit when in the allylic site; activity results on 11 mutants show that both DXXXD conserved domains are essential for PSPP ionization; and the observation that head-to-tail isoprenoid synthases as well as terpene cyclases have ionization and alkene-donor sites which spatially overlap those found in CrtM.

  19. A preconditioning nerve lesion inhibits mechanical pain hypersensitivity following subsequent neuropathic injury

    Directory of Open Access Journals (Sweden)

    Wu Ann

    2011-01-01

    Full Text Available Abstract Background A preconditioning stimulus can trigger a neuroprotective phenotype in the nervous system - a preconditioning nerve lesion causes a significant increase in axonal regeneration, and cerebral preconditioning protects against subsequent ischemia. We hypothesized that a preconditioning nerve lesion induces gene/protein modifications, neuronal changes, and immune activation that may affect pain sensation following subsequent nerve injury. We examined whether a preconditioning lesion affects neuropathic pain and neuroinflammation after peripheral nerve injury. Results We found that a preconditioning crush injury to a terminal branch of the sciatic nerve seven days before partial ligation of the sciatic nerve (PSNL; a model of neuropathic pain induced a significant attenuation of pain hypersensitivity, particularly mechanical allodynia. A preconditioning lesion of the tibial nerve induced a long-term significant increase in paw-withdrawal threshold to mechanical stimuli and paw-withdrawal latency to thermal stimuli, after PSNL. A preconditioning lesion of the common peroneal induced a smaller but significant short-term increase in paw-withdrawal threshold to mechanical stimuli, after PSNL. There was no difference between preconditioned and unconditioned animals in neuronal damage and macrophage and T-cell infiltration into the dorsal root ganglia (DRGs or in astrocyte and microglia activation in the spinal dorsal and ventral horns. Conclusions These results suggest that prior exposure to a mild nerve lesion protects against adverse effects of subsequent neuropathic injury, and that this conditioning-induced inhibition of pain hypersensitivity is not dependent on neuroinflammation in DRGs and spinal cord. Identifying the underlying mechanisms may have important implications for the understanding of neuropathic pain due to nerve injury.

  20. Chemical mechanism of the fluoride-inhibition of fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Warburg, O; Christian, W

    1941-08-01

    Among the fluoride-sensitive fermentation elements, enolase is the most sensitive. An investigation was made, quantitatively, of fluoride inhibition for chemically pure magnesium-enolase using an optical enolase test. Data show that the effective compound for fluoride inhibition is a complex magnesium-fluoro-phosphate and that the magnesium-fluoro-phosphate inhibits fermentation by combining proportionally to its concentration with the ferment-protein in a dissociating manner.

  1. Galvanic Tongue Stimulation Inhibits Five Basic Tastes Induced by Aqueous Electrolyte Solutions

    Directory of Open Access Journals (Sweden)

    Kazuma Aoyama

    2017-12-01

    Full Text Available Galvanic tongue stimulation (GTS modulates taste sensation. However, the effect of GTS is contingent on the electrode polarity in the proximity of the tongue. If an anodal electrode is attached in the proximity of the tongue, an electrical or metallic taste is elicited. On the other hand, if only cathodal electrode is attached in the proximity of the tongue, the salty taste, which is induced by electrolyte materials, is inhibited. The mechanism of this taste inhibition is not adequately understood. In this study, we aim to demonstrate that the inhibition is cause by ions, which elicit taste and which migrate from the taste sensors on the tongue by GTS. We verified the inhibitory effect of GTS on all five basic tastes induced by electrolyte materials. This technology is effective for virtual reality systems and interfaces to support dietary restrictions. Our findings demonstrate that cathodal-GTS inhibits all the five basic tastes. The results also support our hypothesis that the effects of cathodal-GTS are caused by migrating tasting ions in the mouth.

  2. Arginase Inhibition Reverses Monocrotaline-Induced Pulmonary Hypertension

    Directory of Open Access Journals (Sweden)

    Christian Jung

    2017-07-01

    Full Text Available Pulmonary hypertension (PH is a heterogeneous disorder associated with a poor prognosis. Thus, the development of novel treatment strategies is of great interest. The enzyme arginase (Arg is emerging as important player in PH development. The aim of the current study was to determine the expression of ArgI and ArgII as well as the effects of Arg inhibition in a rat model of PH. PH was induced in 35 Sprague–Dawley rats by monocrotaline (MCT, 60 mg/kg as single-dose. There were three experimental groups: sham-treated controls (control group, n = 11, MCT-induced PH (MCT group, n = 11 and MCT-induced PH treated with the Arg inhibitor Nω-hydroxy-nor-l-arginine (nor-NOHA; MCT/NorNoha group, n = 13. ArgI and ArgII expression was determined by immunohistochemistry and Western blot. Right ventricular systolic pressure (RVPsys was measured and lung tissue remodeling was determined. Induction of PH resulted in an increase in RVPsys (81 ± 16 mmHg compared to the control group (41 ± 15 mmHg, p = 0.002 accompanied by a significant elevation of histological sum-score (8.2 ± 2.4 in the MCT compared to 1.6 ± 1.6 in the control group, p < 0.001. Both, ArgI and ArgII were relevantly expressed in lung tissue and there was a significant increase in the MCT compared to the control group (p < 0.01. Arg inhibition resulted in a significant reduction of RVPsys to 52 ± 19 mmHg (p = 0.006 and histological sum-score to 5.8 ± 1.4 compared to the MCT group (p = 0.022. PH leads to increased expression of Arg. Arg inhibition leads to reduction of RVPsys and diminished lung tissue remodeling and therefore represents a potential treatment strategy in PH.

  3. Inhibition of inducible nitric oxide synthesis by azathioprine in a macrophage cell line.

    Science.gov (United States)

    Moeslinger, Thomas; Friedl, Roswitha; Spieckermann, Paul Gerhard

    2006-06-20

    Azathioprine is used as an anti-inflammatory agent. Although there are numerous data demonstrating cytotoxic and immunosuppressive properties of azathioprine and its metabolite 6-mercaptopurine, the mechanism of the anti-inflammatory action of azathioprine has not yet been fully clarified. During our study, we investigated the effects of azathioprine on the inducible nitric oxide synthase (iNOS) in lipopolysaccharide stimulated murine macrophages (RAW 264.7) by measurement of iNOS protein (immunoblotting), iNOS mRNA (semiquantitative competitive RT-PCR), and NO production (nitrite levels). Azathioprine (0-210 muM) induces a concentration dependent inhibition of inducible nitric oxide synthesis (IC50: 33.5 muM). iNOS protein expression showed a concentration dependent reduction as revealed by immunoblotting when cells were incubated with increasing amounts of azathioprine. Azathioprine decreases iNOS mRNA levels as shown by semiquantitative competitive RT-PCR. In contrast, 6-mercaptopurine showed no inhibition of inducible nitric oxide synthesis. Azathioprine did not reduce iNOS mRNA stability after the addition of actinomycin D. Enzymatic activity assays with increasing concentrations of azathioprine (0-210 muM) showed no statistically significant inhibition of iNOS enzyme activity compared to cell lysates without azathioprine. Nuclear translocation of NF-kappaB p65 subunit and binding of NF-kappaB p50 subunit from nuclear extracts to a biotinylated-consensus sequence was unaffected by azathioprine treatment. iNOS inhibition by azathioprine was associated with a decreased expression of IRF-1 (interferon regulatory factor 1) and IFN-beta (beta-interferon) mRNA. Azathioprine induced iNOS inhibition seems to be associated with an action of the methylnitroimidazolyl substituent. This suggests a route to the rational design of nontoxic anti-inflammatory agents by replacing the 6-mercaptopurine component of azathioprine with other substituents. The inhibition of

  4. Acupuncture inhibits cue-induced heroin craving and brain activation.

    Science.gov (United States)

    Cai, Xinghui; Song, Xiaoge; Li, Chuanfu; Xu, Chunsheng; Li, Xiliang; Lu, Qi

    2012-11-25

    Previous research using functional MRI has shown that specific brain regions associated with drug dependence and cue-elicited heroin craving are activated by environmental cues. Craving is an important trigger of heroin relapse, and acupuncture may inhibit craving. In this study, we performed functional MRI in heroin addicts and control subjects. We compared differences in brain activation between the two groups during heroin cue exposure, heroin cue exposure plus acupuncture at the Zusanli point (ST36) without twirling of the needle, and heroin cue exposure plus acupuncture at the Zusanli point with twirling of the needle. Heroin cue exposure elicited significant activation in craving-related brain regions mainly in the frontal lobes and callosal gyri. Acupuncture without twirling did not significantly affect the range of brain activation induced by heroin cue exposure, but significantly changed the extent of the activation in the heroin addicts group. Acupuncture at the Zusanli point with twirling of the needle significantly decreased both the range and extent of activation induced by heroin cue exposure compared with heroin cue exposure plus acupuncture without twirling of the needle. These experimental findings indicate that presentation of heroin cues can induce activation in craving-related brain regions, which are involved in reward, learning and memory, cognition and emotion. Acupuncture at the Zusanli point can rapidly suppress the activation of specific brain regions related to craving, supporting its potential as an intervention for drug craving.

  5. Novel mechanisms to inhibit HIV reservoir seeding using Jak inhibitors.

    Directory of Open Access Journals (Sweden)

    Christina Gavegnano

    2017-12-01

    Full Text Available Despite advances in the treatment of HIV infection with ART, elucidating strategies to overcome HIV persistence, including blockade of viral reservoir establishment, maintenance, and expansion, remains a challenge. T cell homeostasis is a major driver of HIV persistence. Cytokines involved in regulating homeostasis of memory T cells, the major hub of the HIV reservoir, trigger the Jak-STAT pathway. We evaluated the ability of tofacitinib and ruxolitinib, two FDA-approved Jak inhibitors, to block seeding and maintenance of the HIV reservoir in vitro. We provide direct demonstration for involvement of the Jak-STAT pathway in HIV persistence in vivo, ex vivo, and in vitro; pSTAT5 strongly correlates with increased levels of integrated viral DNA in vivo, and in vitro Jak inhibitors reduce the frequency of CD4+ T cells harboring integrated HIV DNA. We show that Jak inhibitors block viral production from infected cells, inhibit γ-C receptor cytokine (IL-15-induced viral reactivation from latent stores thereby preventing transmission of infectious particles to bystander activated T cells. These results show that dysregulation of the Jak-STAT pathway is associated with viral persistence in vivo, and that Jak inhibitors target key events downstream of γ-C cytokine (IL-2, IL-7 and IL-15 ligation to their receptors, impacting the magnitude of the HIV reservoir in all memory CD4 T cell subsets in vitro and ex vivo. Jak inhibitors represent a therapeutic modality to prevent key events of T cell activation that regulate HIV persistence and together, specific, potent blockade of these events may be integrated to future curative strategies.

  6. Mechanisms of radiation induced creep and growth

    International Nuclear Information System (INIS)

    Bullough, R.; Wood, M.H.

    1980-01-01

    Irradiation creep occurs primarily because the applied stress causes the evolving microstructure to respond in an anisotropic fashion to the interstitial and vacancy fluxes. On the other hand, irradiation growth requires the response to be naturally anisotropic in the absence of applied stress. Four fundamental mechanisms of irradiation creep have been conjectured: stress induced preferred absorption (SIPA) of the point defects on the dislocations, stress induced preferred nucleation (SIPN) of point defects in planar aggregates (edge dislocation loops), stress induced climb and glide (SICG) of the dislocation network and stress induced gas driven interstitial deposition (SIGD). These mechanisms will be briefly outlined and commented upon. The contributions made by these mechanisms to the total strain are not, in general, mutually separable and also depend on the prevailing (and changing) microstructure during irradiation. The fundamental mechanism of irradiation growth will be discussed: it is believed to arise by the preferred condensation of point defects and climb of dislocation loops and network on certain crystallographic planes. The preferred absorption and nucleation is thus a consequence of natural crystallographic anisotropy and not due to any external stresses. Again the effectiveness of this mechanism depends on the prevailing microstructure in the material. In this connection will be particularly drawn to the significance of solute trapping, segregation at grain boundaries, dislocation bias for interstitials and transport parameters for an understanding of irradiation growth in materials like zirconium and its alloys; the relevance of recent simulation studies of growth in such materials using electrons to the growth under neutron irradiation will be discussed in detail and a consistent model of growth in these materials will be presented. (orig.)

  7. Vitamin K3 attenuates cerulein-induced acute pancreatitis through inhibition of the autophagic pathway.

    Science.gov (United States)

    Chinzei, Ryo; Masuda, Atsuhiro; Nishiumi, Shin; Nishida, Masayuki; Onoyama, Mitsuko; Sanuki, Tsuyoshi; Fujita, Tsuyoshi; Moritoh, Satoshi; Itoh, Tomoo; Kutsumi, Hiromu; Mizuno, Shigeto; Azuma, Takeshi; Yoshida, Masaru

    2011-01-01

    The discovery of novel and effective treatment methods would be of great help to patients with acute pancreatitis. The aims of this study were to determine the inhibitory effects of vitamin K3 (VK3) against cerulein-induced acute pancreatitis in mice and to examine the mechanisms behind these effects. Acute pancreatitis in mice was induced by intraperitoneal injection of cerulein 6 times at hourly intervals. Vitamin K3 was administered once before the first injection of cerulein or twice before and after the first injection of cerulein. The degrees of inflammation and autophagy in the pancreatic tissue were estimated by histological examination, measurement of enzyme activity, confocal microscopy, and Western blotting. The inhibitory effects of VK3 against rapamycin-induced autophagy were also examined using HeLa cells stably expressing green fluorescent protein LC3. Cerulein-induced acute pancreatitis was markedly attenuated by the administration of VK3. In addition, VK3 led to the inhibition of cerulein-evoked autophagic changes and colocalization of autophagosomes and lysosomes in the pancreatic tissue. Vitamin K3 also reduced rapamycin-induced autophagy in HeLa/green fluorescent protein LC3 cells. Our data suggest that the administration of VK3 reduces pancreatic inflammation in acute pancreatitis through inhibition of the autophagic pathway. Vitamin K3 may be an effective therapeutic strategy against acute pancreatitis.

  8. Mechanism of fluridone-induced seed germination of cistanche tubulosa

    International Nuclear Information System (INIS)

    Chen, Q.L.; Tu, P.

    2016-01-01

    Our previous study disclosed that fluridone, a synthesis inhibitor of abscisic acid (ABA), could stimulate seed germination in the holoparasitic plant Cistanche tubulosa . Nonetheless, the underlying mechanisms have not been thoroughly elucidated. In the present study, an attempt was made to reveal the mechanism of fluridone breaking seed dormancy in C. tubulosa and to determine the contribution of hormones in this process. The ABA level in seeds initially decreased following fluridone treatment and was subsequently maintained at a concentration of 31 ng g/sup -1/ DW (dry weight) three days later. The contents of gibberellins (GAs) initially in creased and subsequently were maintained at a level of 40 ng g-1 DW after ten days. However, the increment of seed germination induced by fluridone was inhibited after the introduction of exogenous ABA or paclobutrazol (a synthesis inhibitor of GAs). Furthermore, inhibition from paclobutrazol was reversed by an additional treatment with exogenous GA3. When the ratio of endogenous GAs to ABA reached 4:3, C. tubulosa seeds initiated germination. By contrast, although the ratio of endogenous GAs to ABA content reached 2:1 by cold stratification, C. tubulosa seeds could not germinate unless exogenous GA3 was added. In summary, our current study revealed that (i) GAs and ABA play key roles for the seed germination of C. tubulosa , (ii) fluridone inhibited ABA biosynthesis but increased the concentration of GAs in seeds, and (iii) fluridone might initiate other processes associated with germination. (author)

  9. Bithionol inhibits ovarian cancer cell growth In Vitro - studies on mechanism(s) of action

    International Nuclear Information System (INIS)

    Ayyagari, Vijayalakshmi N; Brard, Laurent

    2014-01-01

    Drug resistance is a cause of ovarian cancer recurrence and low overall survival rates. There is a need for more effective treatment approaches because the development of new drug is expensive and time consuming. Alternatively, the concept of ‘drug repurposing’ is promising. We focused on Bithionol (BT), a clinically approved anti-parasitic drug as an anti-ovarian cancer drug. BT has previously been shown to inhibit solid tumor growth in several preclinical cancer models. A better understanding of the anti-tumor effects and mechanism(s) of action of BT in ovarian cancer cells is essential for further exploring its therapeutic potential against ovarian cancer. The cytotoxic effects of BT against a panel of ovarian cancer cell lines were determined by Presto Blue cell viability assay. Markers of apoptosis such as caspases 3/7, cPARP induction, nuclear condensation and mitochondrial transmembrane depolarization were assessed using microscopic, FACS and immunoblotting methods. Mechanism(s) of action of BT such as cell cycle arrest, reactive oxygen species (ROS) generation, autotaxin (ATX) inhibition and effects on MAPK and NF-kB signalling were determined by FACS analysis, immunoblotting and colorimetric methods. BT caused dose dependent cytotoxicity against all ovarian cancer cell lines tested with IC 50 values ranging from 19 μM – 60 μM. Cisplatin-resistant variants of A2780 and IGROV-1 have shown almost similar IC 50 values compared to their sensitive counterparts. Apoptotic cell death was shown by expression of caspases 3/7, cPARP, loss of mitochondrial potential, nuclear condensation, and up-regulation of p38 and reduced expression of pAkt, pNF-κB, pIκBα, XIAP, bcl-2 and bcl-xl. BT treatment resulted in cell cycle arrest at G1/M phase and increased ROS generation. Treatment with ascorbic acid resulted in partial restoration of cell viability. In addition, dose and time dependent inhibition of ATX was observed. BT exhibits cytotoxic effects on various

  10. Do pH and flavonoids influence hypochlorous acid-induced catalase inhibition and heme modification?

    Science.gov (United States)

    Krych-Madej, Justyna; Gebicka, Lidia

    2015-09-01

    Hypochlorous acid (HOCl), highly reactive oxidizing and chlorinating species, is formed in the immune response to invading pathogens by the reaction of hydrogen peroxide with chloride catalyzed by the enzyme myeloperoxidase. Catalase, an important antioxidant enzyme, catalyzing decomposition of hydrogen peroxide to water and molecular oxygen, hampers in vitro HOCl formation, but is also one of the main targets for HOCl. In this work we have investigated HOCl-induced catalase inhibition at different pH, and the influence of flavonoids (catechin, epigallocatechin gallate and quercetin) on this process. It has been shown that HOCl-induced catalase inhibition is independent on pH in the range 6.0-7.4. Preincubation of catalase with epigallocatechin gallate and quercetin before HOCl treatment enhances the degree of catalase inhibition, whereas catechin does not affect this process. Our rapid kinetic measurements of absorption changes around the heme group have revealed that heme modification by HOCl is mainly due to secondary, intramolecular processes. The presence of flavonoids, which reduce active catalase intermediate, Compound I to inactive Compound II have not influenced the kinetics of HOCl-induced heme modification. Possible mechanisms of the reaction of hypochlorous acid with catalase are proposed and the biological consequences are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Induction, development, and inhibition of radiation-induced macrobodies

    International Nuclear Information System (INIS)

    Adam, W.J.; Grunewald, R.

    1975-01-01

    Coleus shoots were exposed to 100,000 R of γ radiation and the fine structure of the apical meristems was examined. Meristems were fixed at various postirradiation times. An ultrastructural body was found associated with irradiated tissue, bound by a single membrane, containing dense osmiophilic bodies, and usually associated with radiation-induced vacuoles. The development of these new bodies, and the effects of both dose rate and light during the postirradiation period on their development were examined. Reduction of the dose rate by a factor of two inhibited the formation of these macrobodies through the 24 hour postirradiation period. Meristems kept in the dark during the 24 hour postirradiation period had macrobodies similar in form to the macrobodies from the meristems of the 16 hour postirradiation period which were exposed to light. Superlethal doses were used to achieve these results. Similarities between our results and those achieved with lower lethal doses are discussed

  12. Acetylsalicylic acid inhibits IL-18-induced cardiac fibroblast migration through the induction of RECK.

    Science.gov (United States)

    Siddesha, Jalahalli M; Valente, Anthony J; Sakamuri, Siva S V P; Gardner, Jason D; Delafontaine, Patrice; Noda, Makoto; Chandrasekar, Bysani

    2014-07-01

    The pathogenesis of cardiac fibrosis and adverse remodeling is thought to involve the ROS-dependent induction of inflammatory cytokines and matrix metalloproteinases (MMPs), and the activation and migration of cardiac fibroblasts (CF). Here we investigated the role of RECK (reversion-inducing-cysteine-rich protein with Kazal motifs), a unique membrane-anchored MMP regulator, on IL-18-induced CF migration, and the effect of acetylsalicylic acid (ASA) on this response. In a Matrigel invasion assay, IL-18-induced migration of primary mouse CF was dependent on both IKK/NF-κB- and JNK/AP-1-mediated MMP9 induction and Sp1-mediated RECK suppression, mechanisms that required Nox4-dependent H(2)O(2) generation. Notably, forced expression of RECK attenuated IL-18-induced MMP9 activation and CF migration. Further, therapeutic concentrations of ASA inhibited IL-18-induced H(2)O(2) generation, MMP9 activation, RECK suppression, and CF migration. The salicylic acid moiety of ASA similarly attenuated IL-18-induced CF migration. Thus, ASA may exert potential beneficial effect in cardiac fibrosis through multiple protective mechanisms. © 2013 Wiley Periodicals, Inc.

  13. Mechanisms of radiation-induced neoplastic cell transformation

    International Nuclear Information System (INIS)

    Yang, T.C.H.; Tobias, C.A.

    1984-04-01

    Studies with cultured mammalian cells demonstrated clearly that radiation can transform cells directly and can enhance the cell transformation by oncogenic DNA viruses. In general, high-LET heavy-ion radiation can be more effective than X and gamma rays in inducing neoplastic cell transformation. Various experimental results indicate that radiation-induced DNA damage, most likely double-strand breaks, is important for both the initiation of cell transformation and for the enhancement of viral transformation. Some of the transformation and enhancement lesions can be repaired properly in the cell, and the amount of irrepairable lesions produced by a given dose depends on the quality of radiation. An inhibition of repair processes with chemical agents can increase the transformation frequency of cells exposed to radiation and/or oncogenic viruses, suggesting that repair mechanisms may play an important role in the radiation transformation. The progression of radiation-transformed cells appears to be a long and complicated process that can be modulated by some nonmutagenic chemical agents, e.g., DMSO. Normal cells can inhibit the expression of transforming properties of tumorigenic cells through an as yet unknown mechanism. The progression and expression of transformation may involve some epigenetic changes in the irradiated cells. 38 references, 15 figures, 1 table

  14. Mechanisms of radiation-induced neoplastic cell transformation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, T.C.H.; Tobias, C.A.

    1984-04-01

    Studies with cultured mammalian cells demonstrated clearly that radiation can transform cells directly and can enhance the cell transformation by oncogenic DNA viruses. In general, high-LET heavy-ion radiation can be more effective than X and gamma rays in inducing neoplastic cell transformation. Various experimental results indicate that radiation-induced DNA damage, most likely double-strand breaks, is important for both the initiation of cell transformation and for the enhancement of viral transformation. Some of the transformation and enhancement lesions can be repaired properly in the cell, and the amount of irrepairable lesions produced by a given dose depends on the quality of radiation. An inhibition of repair processes with chemical agents can increase the transformation frequency of cells exposed to radiation and/or oncogenic viruses, suggesting that repair mechanisms may play an important role in the radiation transformation. The progression of radiation-transformed cells appears to be a long and complicated process that can be modulated by some nonmutagenic chemical agents, e.g., DMSO. Normal cells can inhibit the expression of transforming properties of tumorigenic cells through an as yet unknown mechanism. The progression and expression of transformation may involve some epigenetic changes in the irradiated cells. 38 references, 15 figures, 1 table.

  15. Inhibiting extracellular matrix metalloproteinase inducer maybe beneficial for diminishing the atherosclerotic plaque instability

    Directory of Open Access Journals (Sweden)

    Xie S

    2009-01-01

    Full Text Available Atherosclerotic plaque rupture and local thrombosis activation in the artery cause acute serious incidents such as acute coronary syndrome and stroke. The exact mechanism of plaque rupture remains unclear but excessive degradation of the extracellular matrix scaffold by matrix-degrading metalloproteinases (MMPs has been implicated as one of the major molecular mechanisms in this process. Convincing evidence is available to prove that extracellular matrix metalloproteinase inducer (EMMPRIN induces MMP expression and is involved in the inflammatory responses in the artery wall. The inflammation and MMPs have been shown to play a critical role for atherosclerotic lesion development and progression. More recent data showed that increased EMMPRIN expression was associated with vulnerable atherosclerotic lesions. Therefore, we speculate that EMMPRIN may be pivotal for atherosclerotic plaque instability, and hence inhibition of EMMPRIN expression could be a promising approach for the prevention or treatment of atheroma instability.

  16. Mechanism of chlorphentermine-induced lymphocyte toxicity: initial investigations

    International Nuclear Information System (INIS)

    Sauers, L.J.; Wierda, D.; Reasor, M.J.

    1986-01-01

    Chlorphentermine (CP) inhibits the blastogenic response of mouse splenic and human peripheral blood lymphocytes to the T-cell mitogens, phytohemagglutinin (PHA) and concanavalin A (Con A). The purpose of these studies was to examine in vitro the mechanism mediating this immunosuppression. If mouse or human lymphocytes are pretreated with CP for 30 minutes, then stimulated with PHA, their blastogenic response is inhibited 80% and 45%, respectively. However, if CP is not added until 10 minutes or later following PHA stimulation, the inhibitory effect of the drug is essentially eliminated. The authors also determined that CP can potentiate Con A-induced agglutination of human lymphocytes. Enhanced agglutination can result from changes in the integrity of membrane phospholipids. Because changes in membrane phospholipid biochemistry characteristically occur within 10 minutes after mitogen-induced lymphocyte activation, the authors examined whether CP altered the incorporation of choline into cellular phospholipids. They found that CP decreases overall incorporation of 14 C-choline into cellular phospholipids of mouse lymphocytes by 45% during the first 4 hours of activation. These data suggest that the immunotoxicity associated with CP may be mediated by drug-induced changes at the membrane level that appear to occur early during lymphocyte activation

  17. Muscle hypertrophy induced by myostatin inhibition accelerates degeneration in dysferlinopathy.

    Science.gov (United States)

    Lee, Yun-Sil; Lehar, Adam; Sebald, Suzanne; Liu, Min; Swaggart, Kayleigh A; Talbot, C Conover; Pytel, Peter; Barton, Elisabeth R; McNally, Elizabeth M; Lee, Se-Jin

    2015-10-15

    Myostatin is a secreted signaling molecule that normally acts to limit muscle growth. As a result, there is extensive effort directed at developing drugs capable of targeting myostatin to treat patients with muscle loss. One potential concern with this therapeutic approach in patients with muscle degenerative diseases like muscular dystrophy is that inducing hypertrophy may increase stress on dystrophic fibers, thereby accelerating disease progression. To investigate this possibility, we examined the effect of blocking the myostatin pathway in dysferlin-deficient (Dysf(-/-)) mice, in which membrane repair is compromised, either by transgenic expression of follistatin in skeletal muscle or by systemic administration of the soluble form of the activin type IIB receptor (ACVR2B/Fc). Here, we show that myostatin inhibition by follistatin transgene expression in Dysf(-/-) mice results in early improvement in histopathology but ultimately exacerbates muscle degeneration; this effect was not observed in dystrophin-deficient (mdx) mice, suggesting that accelerated degeneration induced by follistatin transgene expression is specific to mice lacking dysferlin. Dysf(-/-) mice injected with ACVR2B/Fc showed significant increases in muscle mass and amelioration of fibrotic changes normally seen in 8-month-old Dysf(-/-) mice. Despite these potentially beneficial effects, ACVR2B/Fc treatment caused increases in serum CK levels in some Dysf(-/-) mice, indicating possible muscle damage induced by hypertrophy. These findings suggest that depending on the disease context, inducing muscle hypertrophy by myostatin blockade may have detrimental effects, which need to be weighed against the potential gains in muscle growth and decreased fibrosis. © The Author 2015. Published by Oxford University Press.

  18. Estradiol-induced vaginal mucus inhibits antigen penetration and CD8(+) T cell priming in response to intravaginal immunization.

    Science.gov (United States)

    Seavey, Matthew M; Mosmann, Tim R

    2009-04-14

    Although vaginal immunization has been explored as a strategy to induce mucosal immunity in the female reproductive tract, this site displays unique immunological features that probably evolved to inhibit anti-paternal T cell responses after insemination to allow successful pregnancy. We previously demonstrated that estradiol, which induces an estrus-like state, prevented CD8(+) T cell priming during intravaginal immunization of mice. We now show that estradiol prevented antigen loading of vaginal antigen presenting cells (APCs) after intravaginal immunization. Histological examination confirmed that estradiol prevented penetration of peptide antigen into the vaginal wall. Removal of the estradiol-induced mucus barrier by mucinase partially restored antigen loading of vaginal APC and CD8(+) T cell proliferation in vivo. The estradiol-induced mucus barrier may thus prevent exposure to antigens delivered intravaginally, supplementing additional estradiol-dependent mechanism(s) that inhibit CD8(+) T cell priming after insemination or vaginal vaccination.

  19. Estradiol-induced vaginal mucus inhibits antigen penetration and CD8+ T cell priming in response to intravaginal immunization

    Science.gov (United States)

    Seavey, Matthew M.; Mosmann, Tim R.

    2010-01-01

    Although vaginal immunization has been explored as a strategy to induce mucosal immunity in the female reproductive tract, this site displays unique immunological features that probably evolved to inhibit anti-paternal T cell responses after insemination to allow successful pregnancy. We previously demonstrated that estradiol, which induces an estrus-like state, prevented CD8+ T cell priming during intravaginal immunization of mice. We now show that estradiol prevented antigen loading of vaginal antigen presenting cells (APC) after intravaginal immunization. Histological examination confirmed that estradiol prevented penetration of peptide antigen into the vaginal wall. Removal of the estradiol-induced mucus barrier by mucinase partially restored antigen loading of vaginal APC and CD8+ T cell proliferation in vivo. The estradiol-induced mucus barrier may thus prevent exposure to antigens delivered intravaginally, supplementing additional estradiol-dependent mechanism(s) that inhibit CD8+ T cell priming after insemination or vaginal vaccination. PMID:19428849

  20. Steroid sulfatase inhibition success and limitation in breast cancer clinical assays: an underlying mechanism.

    Science.gov (United States)

    Sang, Xiaoye; Han, Hui; Poirier, Donald; Lin, Sheng Xiang

    2018-05-24

    Steroid sulfatase is detectable in most hormone-dependent breast cancers. STX64, an STS inhibitor, induced tumor reduction in animal assay. Despite success in phase І clinical trial, the results of phase II trial were not that significant. Breast Cancer epithelial cells (MCF-7 and T47D) were treated with two STS inhibitors (STX64 and EM1913). Cell proliferation, cell cycle, and the concentrations of estradiol and 5α-dihydrotestosterone were measured to determine the endocrinological mechanism of sulfatase inhibition. Comparisons were made with inhibitions of reductive 17β-hydroxysteroid dehydrogenases (17β-HSDs). Proliferation studies showed that DNA synthesis in cancer cells was modestly decreased (approximately 20%), accompanied by an up to 6.5% in cells in the G0/G1 phase and cyclin D1 expression reduction. The concentrations of estradiol and 5α-dihydrotestosterone were decreased by 26% and 3% respectively. However, supplementation of 5α-dihydrotestosterone produced a significant increase (approximately 35.6%) in the anti-proliferative effect of sulfatase inhibition. This study has clarified sex-hormone control by sulfatase in BC, suggesting that the different roles of estradiol and 5α-dihydrotestosterone can lead to a reduction in the effect of sulfatase inhibition when compared with 17β-HSD7 inhibition. This suggests that combined treatment of sulfatase inhibitors with 17β-HSD inhibitors such as the type7 inhibitor could hold promise for hormone-dependent breast cancer. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. A Mechanism of Virus-Induced Demyelination

    Directory of Open Access Journals (Sweden)

    Jayasri Das Sarma

    2010-01-01

    Full Text Available Myelin forms an insulating sheath surrounding axons in the central and peripheral nervous systems and is essential for rapid propagation of neuronal action potentials. Demyelination is an acquired disorder in which normally formed myelin degenerates, exposing axons to the extracellular environment. The result is dysfunction of normal neuron-to-neuron communication and in many cases, varying degrees of axonal degeneration. Numerous central nervous system demyelinating disorders exist, including multiple sclerosis. Although demyelination is the major manifestation of most of the demyelinating diseases, recent studies have clearly documented concomitant axonal loss to varying degrees resulting in long-term disability. Axonal injury may occur secondary to myelin damage (outside-in model or myelin damage may occur secondary to axonal injury (inside-out model. Viral induced demyelination models, has provided unique imminent into the cellular mechanisms of myelin destruction. They illustrate mechanisms of viral persistence, including latent infections, virus reactivation and viral-induced tissue damage. These studies have also provided excellent paradigms to study the interactions between the immune system and the central nervous system (CNS. In this review we will discuss potential cellular and molecular mechanism of central nervous system axonal loss and demyelination in a viral induced mouse model of multiple sclerosis.

  2. Isometric exercise induces analgesia and reduces inhibition in patellar tendinopathy.

    Science.gov (United States)

    Rio, Ebonie; Kidgell, Dawson; Purdam, Craig; Gaida, Jamie; Moseley, G Lorimer; Pearce, Alan J; Cook, Jill

    2015-10-01

    Few interventions reduce patellar tendinopathy (PT) pain in the short term. Eccentric exercises are painful and have limited effectiveness during the competitive season. Isometric and isotonic muscle contractions may have an immediate effect on PT pain. This single-blinded, randomised cross-over study compared immediate and 45 min effects following a bout of isometric and isotonic muscle contractions. Outcome measures were PT pain during the single-leg decline squat (SLDS, 0-10), quadriceps strength on maximal voluntary isometric contraction (MVIC), and measures of corticospinal excitability and inhibition. Data were analysed using a split-plot in time-repeated measures analysis of variance (ANOVA). 6 volleyball players with PT participated. Condition effects were detected with greater pain relief immediately from isometric contractions: isometric contractions reduced SLDS (mean±SD) from 7.0±2.04 to 0.17±0.41, and isotonic contractions reduced SLDS (mean±SD) from 6.33±2.80 to 3.75±3.28 (peffect on inhibition (pre 30.26±3.89, post 31.92±4.67; p=0.004). Condition by time analysis showed pain reduction was sustained at 45 min postisometric but not isotonic condition (ptendon pain immediately for at least 45 min postintervention and increased MVIC. The reduction in pain was paralleled by a reduction in cortical inhibition, providing insight into potential mechanisms. Isometric contractions can be completed without pain for people with PT. The clinical implications are that isometric muscle contractions may be used to reduce pain in people with PT without a reduction in muscle strength. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  3. Metallofullerenol Inhibits Cellular Iron Uptake by Inducing Transferrin Tetramerization.

    Science.gov (United States)

    Li, Jinxia; Xing, Xueqing; Sun, Baoyun; Zhao, Yuliang; Wu, Zhonghua

    2017-10-18

    Herein, A549 tumor cell proliferation was confirmed to be positively dependent on the concentration of Fe 3+ or transferrin (Tf). Gd@C 82 (OH) 22 or C 60 (OH) 22 effectively inhibited the iron uptake and the subsequent proliferation of A549 cells. The conformational changes of Tf mixed with FeCl 3 , GdCl 3 , C 60 (OH) 22 or Gd@C 82 (OH) 22 were obtained by SAXS. The results demonstrate that Tf homodimers can be decomposed into monomers in the presence of FeCl 3 , GdCl 3 or C 60 (OH) 22 , but associated into tetramers in the presence of Gd@C 82 (OH) 22 . The larger change of SAXS shapes between Tf+C 60 (OH) 22 and Tf+FeCl 3 implies that C 60 (OH) 22 is bound to Tf, blocking the iron-binding site. The larger deviation of the SAXS shape from a possible crystal structure of Tf tetramer implies that Gd@C 82 (OH) 22 is bound to the Tf tetramer, thus disturbing iron transport. This study well explains the inhibition mechanism of Gd@C 82 (OH) 22 and C 60 (OH) 22 on the iron uptake and the proliferation of A549 tumor cells and highlights the specific interactions of a nanomedicine with the target biomolecules in cancer therapy. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Puromycin induces SUMO and ubiquitin redistribution upon proteasome inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Hotaru [Course for Biological Sciences, Faculty of Science, Kumamoto University, Kumamoto (Japan); Saitoh, Hisato, E-mail: hisa@kumamoto-u.ac.jp [Course for Biological Sciences, Faculty of Science, Kumamoto University, Kumamoto (Japan); Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kumamoto (Japan)

    2016-07-29

    We have previously reported the co-localization of O-propargyl-puromycin (OP-Puro) with SUMO-2/3 and ubiquitin at promyelocytic leukemia-nuclear bodies (PML-NBs) in the presence of the proteasome inhibitor MG132, implying a role for the ubiquitin family in sequestering OP-puromycylated immature polypeptides to the nucleus during impaired proteasome activity. Here, we found that as expected puromycin induced SUMO-1/2/3 accumulation with ubiquitin at multiple nuclear foci in HeLa cells when co-exposed to MG132. Co-administration of puromycin and MG132 also facilitated redistribution of PML and the SUMO-targeted ubiquitin ligase RNF4 concurrently with SUMO-2/3. As removal of the drugs from the medium led to disappearance of the SUMO-2/3-ubiquitin nuclear foci, our findings indicated that nuclear assembly/disassembly of SUMO-2/3 and ubiquitin was pharmacologically manipulable, supporting our previous observation on OP-Puro, which predicted the ubiquitin family function in sequestrating aberrant proteins to the nucleus. -- Highlights: •Puromycin exhibits the O-propargyl-puromycin effect. •Puromycin induces SUMO redistribution upon proteasome inhibition. •Ubiquitin and RNF4 accumulate at PML-nuclear bodies with SUMO-2/3. •The ubiquitin family may function in nuclear sequestration of immature proteins.

  5. Puromycin induces SUMO and ubiquitin redistribution upon proteasome inhibition

    International Nuclear Information System (INIS)

    Matsumoto, Hotaru; Saitoh, Hisato

    2016-01-01

    We have previously reported the co-localization of O-propargyl-puromycin (OP-Puro) with SUMO-2/3 and ubiquitin at promyelocytic leukemia-nuclear bodies (PML-NBs) in the presence of the proteasome inhibitor MG132, implying a role for the ubiquitin family in sequestering OP-puromycylated immature polypeptides to the nucleus during impaired proteasome activity. Here, we found that as expected puromycin induced SUMO-1/2/3 accumulation with ubiquitin at multiple nuclear foci in HeLa cells when co-exposed to MG132. Co-administration of puromycin and MG132 also facilitated redistribution of PML and the SUMO-targeted ubiquitin ligase RNF4 concurrently with SUMO-2/3. As removal of the drugs from the medium led to disappearance of the SUMO-2/3-ubiquitin nuclear foci, our findings indicated that nuclear assembly/disassembly of SUMO-2/3 and ubiquitin was pharmacologically manipulable, supporting our previous observation on OP-Puro, which predicted the ubiquitin family function in sequestrating aberrant proteins to the nucleus. -- Highlights: •Puromycin exhibits the O-propargyl-puromycin effect. •Puromycin induces SUMO redistribution upon proteasome inhibition. •Ubiquitin and RNF4 accumulate at PML-nuclear bodies with SUMO-2/3. •The ubiquitin family may function in nuclear sequestration of immature proteins.

  6. Exercise and IL-6 infusion inhibit endotoxin-induced TNF-alpha production in humans

    DEFF Research Database (Denmark)

    Starkie, Rebecca; Ostrowski, Sisse Rye; Jauffred, Sune

    2003-01-01

    and atherosclerosis. To test this hypothesis, we performed three experiments in which eight healthy males either rested (CON), rode a bicycle for 3 h (EX), or were infused with recombinant human IL-6 (rhIL-6) for 3 h while they rested. After 2.5 h, the volunteers received a bolus of Escherichia coli...... exercise and rhIL-6 infusion at physiological concentrations inhibit endotoxin-induced TNF-alpha production in humans. Hence, these data provide the first experimental evidence that physical activity mediates antiinflammatory activity and suggest that the mechanism include IL-6, which is produced...

  7. Inhibition of protein kinase A and GIRK channel reverses fentanyl-induced respiratory depression.

    Science.gov (United States)

    Liang, Xiaonan; Yong, Zheng; Su, Ruibin

    2018-06-11

    Opioid-induced respiratory depression is a major obstacle to improving the clinical management of moderate to severe chronic pain. Opioids inhibit neuronal activity via various pathways, including calcium channels, adenylyl cyclase, and potassium channels. Currently, the underlying molecular pathway of opioid-induced respiratory depression is only partially understood. This study aimed to investigate the mechanisms of opioid-induced respiratory depression in vivo by examining the effects of different pharmacological agents on fentanyl-induced respiratory depression. Respiratory parameters were detected using whole body plethysmography in conscious rats. We show that pre-treatment with the protein kinase A (PKA) inhibitor H89 reversed the fentanyl-related effects on respiratory rate, inspiratory time, and expiratory time. Pre-treatment with the G protein-gated inwardly rectifying potassium (GIRK) channel blocker Tertiapin-Q dose-dependently reversed the fentanyl-related effects on respiratory rate and inspiratory time. A phosphodiesterase 4 (PDE4) inhibitor and cyclic adenosine monophosphate (cAMP) analogs did not affect fentanyl-induced respiratory depression. These findings suggest that PKA and GIRK may be involved in fentanyl-induced respiratory depression and could represent useful therapeutic targets for the treatment of fentanyl-induced ventilatory depression. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Celastrol inhibits TGF-β1-induced epithelial–mesenchymal transition by inhibiting Snail and regulating E-cadherin expression

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyereen; Lee, Minjae [Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Jang, Sung-Wuk, E-mail: swjang@amc.seoul.kr [Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of)

    2013-08-09

    Highlights: •We investigated the effects of celastrol on TGF-β1-induced EMT in epithelial cells. •Celastrol regulates TGF-β1-induced morphological changes and E-cadherin expression. •Celastrol inhibits TGF-β1-induced Snail expression. •Celastrol strongly suppresses TGF-β1-induced invasion in MDCK and A549 cells. -- Abstract: The epithelial–mesenchymal transition (EMT) is a pivotal event in the invasive and metastatic potentials of cancer progression. Celastrol inhibits the proliferation of a variety of tumor cells including leukemia, glioma, prostate, and breast cancer; however, the possible role of celastrol in the EMT is unclear. We investigated the effect of celastrol on the EMT. Transforming growth factor-beta 1 (TGF-β1) induced EMT-like morphologic changes and upregulation of Snail expression. The downregulation of E-cadherin expression and upregulation of Snail in Madin–Darby Canine Kidney (MDCK) and A549 cell lines show that TGF-β1-mediated the EMT in epithelial cells; however, celastrol markedly inhibited TGF-β1-induced morphologic changes, Snail upregulation, and E-cadherin expression. Migration and invasion assays revealed that celastrol completely inhibited TGF-β1-mediated cellular migration in both cell lines. These findings indicate that celastrol downregulates Snail expression, thereby inhibiting TGF-β1-induced EMT in MDCK and A549 cells. Thus, our findings provide new evidence that celastrol suppresses lung cancer invasion and migration by inhibiting TGF-β1-induced EMT.

  9. MFGE8 inhibits inflammasome-induced IL-1β production and limits postischemic cerebral injury.

    Science.gov (United States)

    Deroide, Nicolas; Li, Xuan; Lerouet, Dominique; Van Vré, Emily; Baker, Lauren; Harrison, James; Poittevin, Marine; Masters, Leanne; Nih, Lina; Margaill, Isabelle; Iwakura, Yoichiro; Ryffel, Bernhard; Pocard, Marc; Tedgui, Alain; Kubis, Nathalie; Mallat, Ziad

    2013-03-01

    Milk fat globule-EGF 8 (MFGE8) plays important, nonredundant roles in several biological processes, including apoptotic cell clearance, angiogenesis, and adaptive immunity. Several recent studies have reported a potential role for MFGE8 in regulation of the innate immune response; however, the precise mechanisms underlying this role are poorly understood. Here, we show that MFGE8 is an endogenous inhibitor of inflammasome-induced IL-1β production. MFGE8 inhibited necrotic cell-induced and ATP-dependent IL-1β production by macrophages through mediation of integrin β(3) and P2X7 receptor interactions in primed cells. Itgb3 deficiency in macrophages abrogated the inhibitory effect of MFGE8 on ATP-induced IL-1β production. In a setting of postischemic cerebral injury in mice, MFGE8 deficiency was associated with enhanced IL-1β production and larger infarct size; the latter was abolished after treatment with IL-1 receptor antagonist. MFGE8 supplementation significantly dampened caspase-1 activation and IL-1β production and reduced infarct size in wild-type mice, but did not limit cerebral necrosis in Il1b-, Itgb3-, or P2rx7-deficient animals. In conclusion, we demonstrated that MFGE8 regulates innate immunity through inhibition of inflammasome-induced IL-1β production.

  10. Annonaceous acetogenin mimic AA005 induces cancer cell death via apoptosis inducing factor through a caspase-3-independent mechanism

    OpenAIRE

    Han, Bing; Wang, Tong-Dan; Shen, Shao-Ming; Yu, Yun; Mao, Chan; Yao, Zhu-Jun; Wang, Li-Shun

    2015-01-01

    Background Annonaceous acetogenins are a family of natural products with antitumor activities. Annonaceous acetogenin mimic AA005 reportedly inhibits mammalian mitochondrial NADH-ubiquinone reductase (Complex I) and induces gastric cancer cell death. However, the mechanisms underlying its cell-death-inducing activity are unclear. Methods We used SW620 colorectal adenocarcinoma cells to study AA005 cytotoxic activity. Cell deaths were determined by Trypan blue assay and flow cytometry, and rel...

  11. Inhibition of Helicobacter pylori and Its Associated Urease by Palmatine: Investigation on the Potential Mechanism.

    Science.gov (United States)

    Zhou, Jiang-Tao; Li, Cai-Lan; Tan, Li-Hua; Xu, Yi-Fei; Liu, Yu-Hong; Mo, Zhi-Zhun; Dou, Yao-Xing; Su, Rui; Su, Zi-Ren; Huang, Ping; Xie, Jian-Hui

    2017-01-01

    In this paper, we evaluated the anti-Helicobacter pylori activity and the possible inhibitory effect on its associated urease by Palmatine (Pal) from Coptis chinensis, and explored the potential underlying mechanism. Results indicated that Pal exerted inhibitory effect on four tested H. pylori strains (ATCC 43504, NCTC 26695, SS1 and ICDC 111001) by the agar dilution test with minimum inhibitory concentration (MIC) values ranging from 100 to 200 μg/mL under neutral environment (pH 7.4), and from 75 to 100 μg/mL under acidic conditions (pH 5.3), respectively. Pal was observed to significantly inhibit both H. pylori urease (HPU) and jack bean urease (JBU) in a dose-dependent manner, with IC50 values of 0.53 ± 0.01 mM and 0.03 ± 0.00 mM, respectively, as compared with acetohydroxamic acid, a well-known urease inhibitor (0.07 ± 0.01 mM for HPU and 0.02 ± 0.00 mM for JBU, respectively). Kinetic analyses showed that the type of urease inhibition by Pal was noncompetitive for both HPU and JBU. Higher effectiveness of thiol protectors against urease inhibition than the competitive Ni2+ binding inhibitors was observed, indicating the essential role of the active-site sulfhydryl group in the urease inhibition by Pal. DTT reactivation assay indicated that the inhibition on the two ureases was reversible, further supporting that sulfhydryl group should be obligatory for urease inhibition by Pal. Furthermore, molecular docking study indicated that Pal interacted with the important sulfhydryl groups and inhibited the active enzymatic conformation through N-H ∙ π interaction, but did not interact with the active site Ni2+. Taken together, Pal was an effective inhibitor of H. pylori and its urease targeting the sulfhydryl groups, representing a promising candidate as novel urease inhibitor. This investigation also gave additional scientific support to the use of C. chinensis to treat H. pylori-related gastrointestinal diseases in traditional Chinese medicine. Pal might be

  12. JNK inhibition sensitizes tumor cells to radiation-induced premature senescence via Bcl-2/ROS/DDR signaling pathway

    International Nuclear Information System (INIS)

    Lee, Jae Seon; Lee, Je Jung

    2009-01-01

    Premature senescence is considered as a cellular defense mechanism to prevent tumorigenesis. Although recent evidences demonstrate that c-Jun N-terminal kinase (JNK) is involved in the senescence process, the target and exact mechanism of JNK signaling in the regulation of cell proliferation has yet to be defined. In this study, we investigated the role of JNK in premature senescence and demonstrated JNK inhibition sensitized tumor cells to radiation-induced premature senescence

  13. Limonene inhibits Candida albicans growth by inducing apoptosis.

    Science.gov (United States)

    Thakre, Archana; Zore, Gajanan; Kodgire, Santosh; Kazi, Rubina; Mulange, Shradha; Patil, Rajendra; Shelar, Amruta; Santhakumari, Bayitigeri; Kulkarni, Mahesh; Kharat, Kiran; Karuppayil, Sankunny Mohan

    2018-07-01

    Anti-Candida potential of limonene was evaluated against planktonic growth, biofilm (adhesion, development and maturation) and morphogenesis of Candida albicans in this study. Limonene is a major constituent of citrus oil and most frequently used terpene in food and beverage industry due to its pleasant fragrance, nontoxic, and is generally recognized as safe (GRAS) flavoring agent as well as treatment option in many gastrointestinal diseases.Limonene exhibited excellent anti-Candida activity and was equally effective against planktonic growth of C. albicans isolates differentially susceptible to FLC (N = 35). Limonene inhibited morphogenesis significantly at low concentration. However, it showed stage dependent activity against biofilm formation, that is, it was more effective against adhesion followed by development and maturation. Limonene also exhibited excellent synergy with FLC against planktonic and biofilm growth. SWATH-MS analysis led to identification of limonene responsive proteins that provided molecular insight of its anti-Candida activity. Proteomic analysis revealed upregulation of proteins involved in cell wall glucan synthesis (Kre6); oxidative stress (Rhr2, Adh7 and Ebp1); DNA damage stress (Mbf1 and Npl3); nucleolar stress (Rpl11, Rpl7, Rpl29, Rpl15) and down regulation of cytoskeleton organization (Crn1, Pin3, Cct8, Rbl2), and so forth, in response to limonene. Limonene mediated down regulation of Tps3 indicates activation of caspase (CaMca1) and induction of apoptosis in C. albicans. These results suggest that limonene inhibits C. albicans growth by cell wall/membrane damage induced oxidative stress that leads to DNA damage resulting into modulation of cell cycle and induction of apoptosis through nucleolar stress and metacaspase dependent pathway.

  14. Caffeic acid phenethyl ester inhibits 3-MC-induced CYP1A1 expression through induction of hypoxia-inducible factor-1α

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Gyun [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of); Han, Eun Hee [Division of Life Science, Korea Basic Science Institute, Daejeon (Korea, Republic of); Im, Ji Hye; Lee, Eun Ji; Jin, Sun Woo [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of); Jeong, Hye Gwang, E-mail: hgjeong@cnu.ac.kr [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of)

    2015-09-25

    Caffeic acid phenethyl ester (CAPE), a natural component of propolis, is reported to have anticarcinogenic properties, although its precise chemopreventive mechanism remains unclear. In this study, we examined the effects of CAPE on 3-methylcholanthrene (3-MC)-induced CYP1A1 expression and activities. CAPE reduced the formation of the benzo[a]pyrene-DNA adduct. Moreover, CAPE inhibited 3-MC-induced CYP1A1 activity, mRNA expression, protein level, and promoter activity. CAPE treatment also decreased 3-MC-inducible xenobiotic-response element (XRE)-linked luciferase, aryl hydrocarbons receptor (AhR) transactivation and nuclear localization. CAPE induced hypoxia inducible factor-1α (HIF-1α) protein level and HIF-1α responsible element (HRE) transcriptional activity. CAPE-mediated HIF-1α reduced 3-MC-inducible CYP1A1 protein expression. Taken together, CAPE decreases 3-MC-mediated CYP1A1 expression, and this inhibitory response is associated with inhibition of AhR and HIF-1α induction. - Highlights: • CAPE reduced the formation of the benzo[a]pyrene-DNA adduct. • CAPE inhibited 3-MC-induced CYP1A1 expression. • CAPE induced HIF-1α induction. • CAPE-mediated HIF-1α reduced 3-MC-inducible CYP1A1 expression.

  15. 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.

  16. Resveratrol Inhibition of Cellular Respiration: New Paradigm for an Old Mechanism

    Directory of Open Access Journals (Sweden)

    Luis Alberto Madrigal-Perez

    2016-03-01

    Full Text Available Resveratrol (3,4′,5-trihydroxy-trans-stilbene, RSV has emerged as an important molecule in the biomedical area. This is due to its antioxidant and health benefits exerted in mammals. Nonetheless, early studies have also demonstrated its toxic properties toward plant-pathogenic fungi of this phytochemical. Both effects appear to be opposed and caused by different molecular mechanisms. However, the inhibition of cellular respiration is a hypothesis that might explain both toxic and beneficial properties of resveratrol, since this phytochemical: (1 decreases the production of energy of plant-pathogenic organisms, which prevents their proliferation; (2 increases adenosine monophosphate/adenosine diphosphate (AMP/ADP ratio that can lead to AMP protein kinase (AMPK activation, which is related to its health effects, and (3 increases the reactive oxygen species generation by the inhibition of electron transport. This pro-oxidant effect induces expression of antioxidant enzymes as a mechanism to counteract oxidative stress. In this review, evidence is discussed that supports the hypothesis that cellular respiration is the main target of resveratrol.

  17. A short caspase-3 isoform inhibits chemotherapy-induced apoptosis by blocking apoptosome assembly.

    Directory of Open Access Journals (Sweden)

    Frédérique Végran

    Full Text Available Alternative splicing of caspase-3 produces a short isoform caspase-3s that antagonizes caspase-3 apoptotic activity. However, the mechanism of apoptosis inhibition by caspase-3s remains unknown. Here we show that exogenous caspase-3 sensitizes MCF-7 and HBL100 breast cancers cells to chemotherapeutic treatments such as etoposide and methotrexate whereas co-transfection with caspase-3s strongly inhibits etoposide and methotrexate-induced apoptosis underlying thus the anti-apoptotic role of caspase-3s. In caspase-3 transfected cells, lamin-A and α-fodrin were cleaved when caspase-3 was activated by etoposide or methotrexate. When caspase-3s was co-transfected, this cleavage was strongly reduced. Depletion of caspase-3 by RNA interference in HBL100 containing endogenous caspase-3s caused reduction in etoposide and methotrexate-induced apoptosis, whereas the depletion of caspase-3s sensitized cells to chemotherapy. In the presence of caspase-3s, a lack of interaction between caspase-3 and caspase-9 was observed. Immunoprecipitation assays showed that caspase-3s binds the pro-forms of caspase-3. This result suggested that the absence of interaction with caspase-9 when both variants of caspase-3 are present contribute to block the apoptosome assembly and inhibit apoptosis. These data support that caspases-3s negatively interferes with caspase-3 activation and apoptosis in breast cancer, and that it can play key roles in the modulation of response to chemotherapeutic treatments.

  18. Cinnamon extract induces tumor cell death through inhibition of NFκB and AP1

    International Nuclear Information System (INIS)

    Kwon, Ho-Keun; Lee, Sung Haeng; Park, Zee Yong; Im, Sin-Hyeog; Hwang, Ji-Sun; So, Jae-Seon; Lee, Choong-Gu; Sahoo, Anupama; Ryu, Jae-Ha; Jeon, Won Kyung; Ko, Byoung Seob; Im, Chang-Rok

    2010-01-01

    Cinnamomum cassia bark is the outer skin of an evergreen tall tree belonging to the family Lauraceae containing several active components such as essential oils (cinnamic aldehyde and cinnamyl aldehyde), tannin, mucus and carbohydrate. They have various biological functions including anti-oxidant, anti-microbial, anti-inflammation, anti-diabetic and anti-tumor activity. Previously, we have reported that anti-cancer effect of cinnamon extracts is associated with modulation of angiogenesis and effector function of CD8 + T cells. In this study, we further identified that anti-tumor effect of cinnamon extracts is also link with enhanced pro-apoptotic activity by inhibiting the activities NFκB and AP1 in mouse melanoma model. Water soluble cinnamon extract was obtained and quality of cinnamon extract was evaluated by HPLC (High Performance Liquid Chromatography) analysis. In this study, we tested anti-tumor activity and elucidated action mechanism of cinnamon extract using various types of tumor cell lines including lymphoma, melanoma, cervix cancer and colorectal cancer in vitro and in vivo mouse melanoma model. Cinnamon extract strongly inhibited tumor cell proliferation in vitro and induced active cell death of tumor cells by up-regulating pro-apoptotic molecules while inhibiting NFκB and AP1 activity and their target genes such as Bcl-2, BcL-xL and survivin. Oral administration of cinnamon extract in melanoma transplantation model significantly inhibited tumor growth with the same mechanism of action observed in vitro. Our study suggests that anti-tumor effect of cinnamon extracts is directly linked with enhanced pro-apoptotic activity and inhibition of NFκB and AP1 activities and their target genes in vitro and in vivo mouse melanoma model. Hence, further elucidation of active components of cinnamon extract could lead to development of potent anti-tumor agent or complementary and alternative medicine for the treatment of diverse cancers

  19. Intravitreal itraconazole inhibits laser-induced choroidal neovascularization in rats.

    Directory of Open Access Journals (Sweden)

    Jeong Hun Bae

    Full Text Available Choroidal neovascularization (CNV is a major cause of severe visual loss in patients with age-related macular degeneration (AMD. Recently, itraconazole has shown potent and dose-dependent inhibition of tumor-associated angiogenesis. We evaluated the anti-angiogenic effect of itraconazole in a rat model of laser-induced CNV. After laser photocoagulation in each eye to cause CNV, right eyes were administered intravitreal injections of itraconazole; left eyes received balanced salt solution (BSS as controls. On day 14 after laser induction, fluorescein angiography (FA was used to assess abnormal vascular leakage. Flattened retinal pigment epithelium (RPE-choroid tissue complex was stained with Alexa Fluor 594-conjugated isolectin B4 to measure the CNV area and volume. Vascular endothelial growth factor receptor 2 (VEGFR2 mRNA and protein expression was determined 1, 4, 7, and 14 days after intravitreal injection by quantitative RT-PCR or Western blot. VEGF levels were analyzed by enzyme-linked immunosorbent assay (ELISA. Intravitreal itraconazole significantly reduced leakage from CNV as assessed by FA and CNV area and volume on flat mounts compared with intravitreal BSS (p = 0.002 for CNV leakage, p<0.001 for CNV area and volume. Quantitative RT-PCR showed significantly lower expression of VEGFR2 mRNA in the RPE-choroid complexes of itraconazole-injected eyes than those of BSS-injected eyes on days 7 and 14 (p = 0.003 and p = 0.006. Western blots indicated that VEGFR2 was downregulated after itraconazole treatment. ELISA showed a significant difference in VEGF level between itraconazole-injected and BSS-injected eyes on days 7 and 14 (p = 0.04 and p = 0.001. Our study demonstrated that intravitreal itraconazole significantly inhibited the development of laser-induced CNV in rats. Itraconazole had anti-angiogenic activity along with the reduction of VEGFR2 and VEGF levels. Itraconazole may prove beneficial for treating CNV as an alternative or

  20. Sepsis-Induced Cardiomyopathy: Mechanisms and Treatments

    Directory of Open Access Journals (Sweden)

    Yan-Cun Liu

    2017-08-01

    Full Text Available Sepsis is a lethal syndrome with a high incidence and a weighty economy burden. The pathophysiology of sepsis includes inflammation, immune dysfunction, and dysfunction of coagulation, while sepsis-induced cardiomyopathy (SIC, defined as a global but reversible dysfunction of both sides of the heart induced by sepsis, plays a significant role in all of the aspects above in the pathogenesis of sepsis. The complex pathogenesis of SIC involves a combination of dysregulation of inflammatory mediators, mitochondrial dysfunction, oxidative stress, disorder of calcium regulation, autonomic nervous system dysregulation, and endothelial dysfunction. The treatments for SIC include the signal pathway intervention, Chinese traditional medicine, and other specific therapy. Here, we reviewed the latest literatures on the mechanisms and treatments of SIC and hope to provide further insights to researchers and create a new road for the therapy of sepsis.

  1. Mechanisms of Autoantibody-Induced Pathology

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    Ralf J. Ludwig

    2017-05-01

    Full Text Available Autoantibodies are frequently observed in healthy individuals. In a minority of these individuals, they lead to manifestation of autoimmune diseases, such as rheumatoid arthritis or Graves’ disease. Overall, more than 2.5% of the population is affected by autoantibody-driven autoimmune disease. Pathways leading to autoantibody-induced pathology greatly differ among different diseases, and autoantibodies directed against the same antigen, depending on the targeted epitope, can have diverse effects. To foster knowledge in autoantibody-induced pathology and to encourage development of urgently needed novel therapeutic strategies, we here categorized autoantibodies according to their effects. According to our algorithm, autoantibodies can be classified into the following categories: (1 mimic receptor stimulation, (2 blocking of neural transmission, (3 induction of altered signaling, triggering uncontrolled (4 microthrombosis, (5 cell lysis, (6 neutrophil activation, and (7 induction of inflammation. These mechanisms in relation to disease, as well as principles of autoantibody generation and detection, are reviewed herein.

  2. Inhibition of Drp-1 dependent mitochondrial fission augments alcohol-induced cardiotoxicity via dysregulated Akt signaling

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    Anusha Sivakumar

    2017-10-01

    Full Text Available Cardiovascular disorders (CVDs still claim high mortality in spite of advancements in prognosis and treatment strategies. Alcohol is one of the most commonly consumed drugs globally and chronic/binge consumption (BAC 0.08 g/dL in 2 hours is a risk factor for CVDs. However, the aetiology and pathophysiological mechanisms of alcohol induced cardiotoxicity are still poorly understood. Mitochondria are the prime site for the ATP demands of the heart and also ethanol metabolism. These subcellular organelles depict dynamic fusion and fission events that are vital for structure and functional integrity. While fused mitochondrial improve ATP production and cell survival, increased fragmentation can be the cause or result of apoptosis. In this study, we proposed to analyze the mechanism of mitochondrial fission protein Drp-1-dependent apoptosis during alcohol toxicity. Male Wistar rats (220-250 kg body weight were given isocaloric sucrose or ethanol for 45 days, orally, via drinking water and intermittent gavage twice a week. Histopathological examination of the heart displayed hypertrophy with mild inflammation. Drp-1 immunoblotting showed over-expression of the protein during ethanol treatment. We next hypothesized that inhibiting Drp-1 could attenuate alcohol-induced cardiotoxicity. Interestingly, silencing Drp-1 with siRNA in-vitro augmented cytotoxicity. Also, crude mitochondrial fraction showed increased Bak aggregation, reduced cytochrome c release but increased SMAC/DIABLO. We analyzed the Akt cell survival signaling and found that PTEN showed over-expression at both transcriptional and translational level with no significant change in total Akt but down-regulation of p-Akt (Ser473. In conclusion, we have shown that inhibition of Drp-1 dependent mitochondrial fission is not cardioprotective against alcohol-induced apoptotic signaling and augments the cytotoxicity. To our knowledge, this study is the first to interlink cell survival AKT signaling

  3. Dual mechanisms of NF-κB inhibition in carnosol-treated endothelial cells

    International Nuclear Information System (INIS)

    Lian, K.-C.; Chuang, J.-J.; Hsieh, C.-W.; Wung, B.-S.; Huang, G.-D.; Jian, T.-Y.; Sun, Y.-W.

    2010-01-01

    The increased adhesion of monocytes to injured endothelial layers is a critical early event in atherogenesis. Under inflammatory conditions, there is increased expression of specific cell adhesion molecules on activated vascular endothelial cells, which increases monocyte adhesion. In our current study, we demonstrate a putative mechanism for the anti-inflammatory effects of carnosol, a diterpene derived from the herb rosemary. Our results show that both carnosol and rosemary essential oils inhibit the adhesion of TNFα-induced monocytes to endothelial cells and suppress the expression of ICAM-1 at the transcriptional level. Moreover, carnosol was found to exert its inhibitory effects by blocking the degradation of the inhibitory protein IκBα in short term pretreatments but not in 12 h pretreatments. Our data show that carnosol reduces IKK-β phosphorylation in pretreatments of less than 3 h. In TNFα-treated ECs, NF-κB nuclear translocation and transcriptional activity was abolished by up to 12 h of carnosol pretreatment and this was blocked by Nrf-2 siRNA. The long-term inhibitory effects of carnosol thus appear to be mediated through its induction of Nrf-2-related genes. The inhibition of ICAM-1 expression and p65 translocation is reversed by HO-1 siRNA. Carnosol also upregulates the Nrf-2-related glutathione synthase gene and thereby increases the GSH levels after 9 h of exposure. Treating ECs with a GSH synthesis inhibitor, BSO, blocks the inhibitory effects of carnosol. In addition, carnosol increases p65 glutathionylation. Hence, our present findings indicate that carnosol suppresses TNFα-induced singling pathways through the inhibition of IKK-β activity or the upregulation of HO-1 expression. The resulting GSH levels are dependent, however, on the length of the carnosol pretreatment period.

  4. Oleuropein isolated from Fraxinus rhynchophylla inhibits glutamate-induced neuronal cell death by attenuating mitochondrial dysfunction.

    Science.gov (United States)

    Kim, Mi Hye; Min, Ju-Sik; Lee, Joon Yeop; Chae, Unbin; Yang, Eun-Ju; Song, Kyung-Sik; Lee, Hyun-Shik; Lee, Hong Jun; Lee, Sang-Rae; Lee, Dong-Seok

    2017-04-27

    Glutamate-induced neurotoxicity is related to excessive oxidative stress accumulation and results in the increase of neuronal cell death. In addition, glutamate has been reported to lead to neurodegenerative diseases, including Parkinson's and Alzheimer's diseases.It is well known that Fraxinus rhynchophylla contains a significant level of oleuropein (Ole), which exerts various pharmacological effects. However, the mechanism of neuroprotective effects of Ole is still poorly defined. In this study, we aimed to investigate whether Ole prevents glutamate-induced toxicity in HT-22 hippocampal neuronal cells. The exposure of the glutamate treatment caused neuronal cell death through an alteration of Bax/Bcl-2 expression and translocation of mitochondrial apoptosis-inducing factor (AIF) to the cytoplasm of HT-22 cells. In addition, glutamate induced an increase in dephosphorylation of dynamin-related protein 1 (Drp1), mitochondrial fragmentation, and mitochondrial dysfunction. The pretreatment of Ole decreased Bax expression, increased Bcl-2 expression, and inhibited the translocation of mitochondrial AIF to the cytoplasm. Furthermore, Ole amended a glutamate-induced mitochondrial dynamic imbalance and reduced the number of cells with fragmented mitochondria, regulating the phosphorylation of Drp1 at amino acid residue serine 637. In conclusion, our results show that Ole has a preventive effect against glutamate-induced toxicity in HT-22 hippocampal neuronal cells. Therefore, these data imply that Ole may be an efficient approach for the treatment of neurodegenerative diseases.

  5. mTOR inhibition sensitizes ONC201-induced anti-colorectal cancer cell activity.

    Science.gov (United States)

    Jin, Zhe-Zhu; Wang, Wei; Fang, Di-Long; Jin, Yong-Jun

    2016-09-30

    We here tested the anti-colorectal cancer (CRC) activity by a first-in-class small molecule TRAIL inducer ONC201. The potential effect of mTOR on ONC201's actions was also examined. ONC201 induced moderate cytotoxicity against CRC cell lines (HT-29, HCT-116 and DLD-1) and primary human CRC cells. Significantly, AZD-8055, a mTOR kinase inhibitor, sensitized ONC201-induced cytotoxicity in CRC cells. Meanwhile, ONC201-induced TRAIL/death receptor-5 (DR-5) expression, caspase-8 activation and CRC cell apoptosis were also potentiated with AZD-8055 co-treatment. Reversely, TRAIL sequestering antibody RIK-2 or the caspase-8 specific inhibitor z-IETD-fmk attenuated AZD-8055 plus ONC201-induced CRC cell death. Further, mTOR kinase-dead mutation (Asp-2338-Ala) or shRNA knockdown significantly sensitized ONC201's activity in CRC cells, leading to profound cell death and apoptosis. On the other hand, expression of a constitutively-active S6K1 (T389E) attenuated ONC201-induced CRC cell apoptosis. For the mechanism study, we showed that ONC201 blocked Akt, but only slightly inhibited mTOR in CRC cells. Co-treatment with AZD-8055 also concurrently blocked mTOR activation. These results suggest that mTOR could be a primary resistance factor of ONC201 in CRC cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Mechanism of Platinum Derivatives Induced Kidney Injury

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    Feifei YAN

    2015-09-01

    Full Text Available Platinum derivatives are the most widely used chemotherapeutic agents to treat solid tumors including ovarian, head and neck, and testicular germ cell tumors, lung cancer, and colorectal cancer. Two major problems exist, however, in the clinic use of platinum derivatives. One is the development of tumor resistance to the drug during therapy, leading to treatment failure. The other is the drug’s toxicity such as the cisplatin’s nephrotoxicity, which limits the dose that can be administered. This paper describes the mechanism of platinum derivatives induced kidney injury.

  7. Belinostat-induced apoptosis and growth inhibition in pancreatic cancer cells involve activation of TAK1-AMPK signaling axis

    International Nuclear Information System (INIS)

    Wang, Bing; Wang, Xin-bao; Chen, Li-yu; Huang, Ling; Dong, Rui-zen

    2013-01-01

    Highlights: •Belinostat activates AMPK in cultured pancreatic cancer cells. •Activation of AMPK is important for belinostat-induced cytotoxic effects. •ROS and TAK1 are involved in belinostat-induced AMPK activation. •AMPK activation mediates mTOR inhibition by belinostat. -- Abstract: Pancreatic cancer accounts for more than 250,000 deaths worldwide each year. Recent studies have shown that belinostat, a novel pan histone deacetylases inhibitor (HDACi) induces apoptosis and growth inhibition in pancreatic cancer cells. However, the underlying mechanisms are not fully understood. In the current study, we found that AMP-activated protein kinase (AMPK) activation was required for belinostat-induced apoptosis and anti-proliferation in PANC-1 pancreatic cancer cells. A significant AMPK activation was induced by belinostat in PANC-1 cells. Inhibition of AMPK by RNAi knockdown or dominant negative (DN) mutation significantly inhibited belinostat-induced apoptosis in PANC-1 cells. Reversely, AMPK activator AICAR and A-769662 exerted strong cytotoxicity in PANC-1 cells. Belinostat promoted reactive oxygen species (ROS) production in PANC-1 cells, increased ROS induced transforming growth factor-β-activating kinase 1 (TAK1)/AMPK association to activate AMPK. Meanwhile, anti-oxidants N-Acetyl-Cysteine (NAC) and MnTBAP as well as TAK1 shRNA knockdown suppressed belinostat-induced AMPK activation and PANC-1 cell apoptosis. In conclusion, we propose that belinostat-induced apoptosis and growth inhibition require the activation of ROS-TAK1-AMPK signaling axis in cultured pancreatic cancer cells

  8. Belinostat-induced apoptosis and growth inhibition in pancreatic cancer cells involve activation of TAK1-AMPK signaling axis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bing, E-mail: wangbin69@yahoo.com; Wang, Xin-bao; Chen, Li-yu; Huang, Ling; Dong, Rui-zen

    2013-07-19

    Highlights: •Belinostat activates AMPK in cultured pancreatic cancer cells. •Activation of AMPK is important for belinostat-induced cytotoxic effects. •ROS and TAK1 are involved in belinostat-induced AMPK activation. •AMPK activation mediates mTOR inhibition by belinostat. -- Abstract: Pancreatic cancer accounts for more than 250,000 deaths worldwide each year. Recent studies have shown that belinostat, a novel pan histone deacetylases inhibitor (HDACi) induces apoptosis and growth inhibition in pancreatic cancer cells. However, the underlying mechanisms are not fully understood. In the current study, we found that AMP-activated protein kinase (AMPK) activation was required for belinostat-induced apoptosis and anti-proliferation in PANC-1 pancreatic cancer cells. A significant AMPK activation was induced by belinostat in PANC-1 cells. Inhibition of AMPK by RNAi knockdown or dominant negative (DN) mutation significantly inhibited belinostat-induced apoptosis in PANC-1 cells. Reversely, AMPK activator AICAR and A-769662 exerted strong cytotoxicity in PANC-1 cells. Belinostat promoted reactive oxygen species (ROS) production in PANC-1 cells, increased ROS induced transforming growth factor-β-activating kinase 1 (TAK1)/AMPK association to activate AMPK. Meanwhile, anti-oxidants N-Acetyl-Cysteine (NAC) and MnTBAP as well as TAK1 shRNA knockdown suppressed belinostat-induced AMPK activation and PANC-1 cell apoptosis. In conclusion, we propose that belinostat-induced apoptosis and growth inhibition require the activation of ROS-TAK1-AMPK signaling axis in cultured pancreatic cancer cells.

  9. Salidroside Inhibits Myogenesis by Modulating p-Smad3-Induced Myf5 Transcription

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    Peng Zhang

    2018-03-01

    Full Text Available Aim: Salidroside is an active compound extracted from Rhodiola rosea which is used to alleviate fatigue and enhance endurance in high altitude regions. Some studies have demonstrated that salidroside can affect precursor cell differentiation in hematopoietic stem cells, erythrocytes, and osteoblasts. The aim of this study was to investigate the effect of salidroside on myoblast differentiation and to explore the underlying molecular mechanisms of this effect.Methods: C2C12 myoblast cells were treated with different concentrations of salidroside in differentiation media. Real-time PCR, Western blotting, and immunofluorescence assay were employed to evaluate the effects of salidroside on C2C12 differentiation. RNA interference was used to reveal the important role of Myf5 in myogenesis inhibited by salidroside. Chromatin Immunoprecipitation and dual-luciferase reporter assay were utilized to explore the underlying mechanisms of salidroside-induced upregulation of Myf5.Results: We found that salidroside inhibits myogenesis by downregulating MyoD and myogenin, preserves undifferentiated reserve cell pools by upregulating Myf5. Knocking down Myf5 expression significantly rescued the myogenesis inhibited by salidroside. The effect of salidroside on myogenesis was associated with increased phosphorylated Smad3 (p-Smad3. Both SIS3 (Specific inhibitor of p-Smad3 and dominant negative Smad3 plasmid (DN-Smad3 attenuated the inhibitory effect of salidroside on C2C12 differentiation. Moreover, the induction of Myf5 transcription by salidroside was dependent on a Smad-binding site in the promoter region of Myf5 gene.Conclusion and Implications: Our findings identify a novel role and mechanism for salidroside in regulating myogenesis through p-Smad3-induced Myf5 transcription, which may have implications for its further application in combating degenerative muscular diseases caused by depletion of muscle stem cells, such as Duchenne muscular dystrophy or

  10. Tetrahydroxystilbene glucoside improves TNF-α-induced endothelial dysfunction: involvement of TGFβ/Smad pathway and inhibition of vimentin expression.

    Science.gov (United States)

    Yao, Wenjuan; Gu, Chengjing; Shao, Haoran; Meng, Guoliang; Wang, Huiming; Jing, Xiang; Zhang, Wei

    2015-01-01

    Endothelial dysfunction plays an important role in the pathogenesis of atherogenesis. 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside (TSG), an active component of the rhizome extract from Polygonum multiflorum (PM), exhibits significant anti-atherosclerotic activity. Here, we used human umbilical vein endothelial cells (HUVECs) induced by tumor necrosis factor-α (TNF-α) in vitro to investigate the cytoprotective effects of TSG on TNF-α-induced endothelial injury and the related mechanisms. Pretreatment with 50 and 100 μM TSG markedly attenuated TNF-α-induced loss of cell viability and release of lactate dehydrogenase (LDH) and inhibited TNF-α-induced cell apoptosis. The inhibition of vimentin expression was involved in the cytoprotection afforded by TSG. Using inhibitors for PI3K and TGFβ or siRNA for Akt and Smad2, we found that vimentin production in HUVECs is regulated by TGFβ/Smad signaling, but not by PI3K-Akt-mTOR signaling. Meanwhile, TSG inhibited both the expression of TGFβ1 and the phosphorylation of Smad2 and Smad3, and TSG suppressed the nuclear translocation of Smad4 induced by TNF-α. These results suggest that TSG protects HUVECs against TNF-α-induced cell damage by inhibiting vimentin expression via the interruption of the TGFβ/Smad signaling pathway.

  11. Cellular mechanisms for presynaptic inhibition of sensory afferents

    DEFF Research Database (Denmark)

    Perrier, Jean-Francois Marie; delgado-lezama, rodolfo; Christensen, Rasmus Kordt

    It is well established that presynaptic inhibition of primary afferents involves the activation of GABAA receptors located on presynaptic terminals. However, the source of GABA remains unknown. In an integrated preparation of the spinal cord of the adult turtle, we evoked dorsal root potentials...

  12. Neural mechanisms of impaired fear inhibition in posttraumatic stress disorder

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    Tanja eJovanovic

    2011-07-01

    Full Text Available Posttraumatic stress disorder (PTSD can develop in some individuals who are exposed to an event that causes extreme fear, horror, or helplessness (APA, 1994. PTSD is a complex and heterogeneous disorder, which is often co-morbid with depression, substance abuse, and anxiety disorders such as panic or social phobia. Given this complexity, progress in the field can be greatly enhanced by focusing on phenotypes that are more proximal to the neurobiology of the disorder. Such neurobiological intermediate phenotypes can provide investigative tools to increase our understanding of the roots of the disorder and develop better prevention or intervention programs. In the present paper, we argue that the inhibition of fear responses is an intermediate phenotype that is related to both the neurocircuitry associated with the disorder, and is linked to its clinical symptoms. An advantage of focusing on fear inhibition is that the neurobiology of fear has been well investigated in animal models providing the necessary groundwork in understanding alterations. Furthermore, because many paradigms can be tested across species, fear inhibition is an ideal translational tool. Here we review both the behavioral tests and measures of fear inhibition and the related neurocircuitry in neuroimaging studies with both healthy and clinical samples.

  13. Mechanism of inhibition of catalase by nitro and nitroso compounds.

    Science.gov (United States)

    Titov, V Yu; Petrenko, Yu M; Vanin, A F

    2008-01-01

    Dinitrosyl iron complexes (DNIC) with thiolate ligands and S-nitrosothiols, which are NO and NO+ donors, share the earlier demonstrated ability of nitrite for inhibition of catalase. The efficiency of inhibition sharply (by several orders in concentration of these agents) increases in the presence of chloride, bromide, and thiocyanate. The nitro compounds tested--nitroarginine, nitroglycerol, nitrophenol, and furazolidone--gained the same inhibition ability after incubation with ferrous ions and thiols. This is probably the result of their transformation into DNIC. None of these substances lost the inhibitory effect in the presence of the well known NO scavenger oxyhemoglobin. This fact suggests that NO+ ions rather than neutral NO molecules are responsible for the enzyme inactivation due to nitrosation of its structures. The enhancement of catalase inhibition in the presence of halide ions and thiocyanate might be caused by nitrosyl halide formation. The latter protected nitrosonium ions against hydrolysis, thereby ensuring their transfer to the targets in enzyme molecules. The addition of oxyhemoglobin plus iron chelator o-phenanthroline destroying DNIC sharply attenuated the inhibitory effect of DNIC on catalase. o-Phenanthroline added alone did not influence this effect. Oxyhemoglobin is suggested to scavenge nitrosonium ions released from decomposing DNIC, thereby preventing catalase nitrosation. The mixture of oxyhemoglobin and o-phenanthroline did not affect the inhibitory action of nitrite or S-nitrosothiols on catalase.

  14. Radiosensitive Down syndrome lymphoblastoid lines have normal ionizing-radiation-induced inhibition of DNA synthesis

    International Nuclear Information System (INIS)

    Ganges, M.B.; Robbins, J.H.; Jiang, H.; Hauser, C.; Tarone, R.E.

    1988-01-01

    The extent of X-ray-induced inhibition of DNA synthesis was determined in radiosensitive lymphoblastoid lines from 3 patients with Down syndrome and 3 patients with ataxia telangiectasia (AT). Compared to 6 normal control lines, the 3 AT lines were abnormally resistant to X-ray-induced inhibition of DNA synthesis, while the 3 Down syndrome lines had normal inhibition. These results demonstrate that radiosensitive human cells can have normal X-ray-induced inhibition of DNA synthesis and provide new evidence for the dissociation of radioresistant DNA synthesis. (author). 27 refs.; 1 fig.; 1 tab

  15. Mechanism of inhibition of myeloperoxidase by anti-inflammatory drugs.

    Science.gov (United States)

    Kettle, A J; Winterbourn, C C

    1991-05-15

    Hypochlorous acid (HOCl) is the most powerful oxidant produced by human neutrophils, and should therefore be expected to contribute to the damage caused by these inflammatory cells. It is produced from H2O2 and Cl- by the heme enzyme myeloperoxidase (MPO). We used a H2O2-electrode to assess the ability of a variety of anti-inflammatory drugs to inhibit conversion of H2O2 to HOCl. Dapsone, mefenamic acid, sulfapyridine, quinacrine, primaquine and aminopyrine were potent inhibitors, giving 50% inhibition of the initial rate of H2O2 loss at concentrations of about 1 microM or less. Phenylbutazone, piroxicam, salicylate, olsalazine and sulfasalazine were also effective inhibitors. Spectral investigations showed that the inhibitors acted by promoting the formation of compound II, which is an inactive redox intermediate of MPO. Ascorbate reversed inhibition by reducing compound II back to the active enzyme. The characteristic properties that allowed the drugs to inhibit MPO reversibly were ascertained by determining the inhibitory capacity of related phenols and anilines. Inhibition increased as substituents on the aromatic ring became more electron withdrawing, until an optimum reduction potential was reached. Beyond this optimum, their inhibitory capacity declined. The best inhibitor was 4-bromoaniline which had an I50 of 45 nM. An optimum reduction potential enables inhibitors to reduce MPO to compound II, but prevents them from reducing compound II back to the active enzyme. Exploitation of this optimum reduction potential will help in targeting drugs against HOCl-dependent tissue damage.

  16. GSK-3β Inhibition Attenuates CLP-Induced Liver Injury by Reducing Inflammation and Hepatic Cell Apoptosis

    Directory of Open Access Journals (Sweden)

    Hui Zhang

    2014-01-01

    Full Text Available Liver dysfunction has been known to occur frequently in cases of sepsis. Excessive inflammation and apoptosis are pathological features of acute liver failure. Recent studies suggest that activation of glycogen synthase kinase- (GSK- 3β is involved in inflammation and apoptosis. We aimed to investigate the protective effects of GSK-3β inhibition on polymicrobial sepsis-induced liver injury and to explore the possible mechanisms. Polymicrobial sepsis was induced by cecal ligation and puncture (CLP, and SB216763 was used to inhibit GSK-3β in C57BL/6 mice. GSK-3β was activated following CLP. Administration of SB216763 decreased mortality, ameliorated liver injury, and reduced hepatic apoptosis. The inhibition of GSK-3β also reduced leukocyte infiltration and hepatic inflammatory cytokine expression and release. Moreover, GSK-3β inhibition suppressed the transcriptional activity of nuclear factor-kappa B (NF-κB but enhanced the transcriptional activity of cAMP response element binding protein (CREB in the liver. In in vitro studies, GSK-3β inhibition reduced inflammatory cytokine production via modulation of NF-κB and CREB signaling pathways in lipopolysaccharide-stimulated macrophages. In conclusion, these findings suggest that GSK-3β blockade protects against CLP-induced liver via inhibition of inflammation by modulating NF-κB and CREB activity and suppression of hepatic apoptosis.

  17. Gemcitabine inhibits proliferation and induces apoptosis in human pancreatic cancer PANC-1 cells.

    Science.gov (United States)

    Yong-Xian, Gui; Xiao-Huan, Li; Fan, Zhang; Guo-Fang, Tian

    2016-10-01

    The aim of the study is to investigate the underlying molecular mechanisms by which gemcitabine (gem) inhibits proliferation and induces apoptosis in human pancreatic cancer PANC-1 cells in vitro. After PANC-1 cells had been treated by indicated concentration (0, 5, and 25 mg/L) of gem for 48 h, cell proliferation was evaluated by 3'-(4, 5 dimethyl-thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay; cell morphology was observed by transmission electron microscopy; Expression of c-IAP2 and Bcl-2 proteins was analyzed by Western blot; the activity of caspase-3 and -9 was detected by spectrophotometry. Gem significantly inhibited cell proliferation and could induce apoptosis of human pancreatic cancer PANC-1 cells, with a dose-dependent manner. Western blot analysis showed that gem significantly reduced c-IAP2 and Bcl-2 proteins expression level (P PANC-1 cells. Gem could induce apoptosis of human pancreatic cancer PANC-1 cells, probably through downregulating c-IAP2 and Bcl-2 expression levels, and at the same time activating caspase-3 and -9.

  18. Overexpression of SKP2 Inhibits the Radiation-Induced Bystander Effects of Esophageal Carcinoma

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    Xiao-Chun Wang

    2017-02-01

    Full Text Available Background: To investigate the effects of S-phase kinase protein 2 (SKP2 expression on the radiation induced bystander effect (RIBE in esophageal cancer (EC cells. Materials and Methods: Western blot was used to detect the levels of SKP2, Rad51, and Ku70 in EC cells. Positive transfection, RNAi, micronucleus (MN, and γ-H2AX focus formation assay were used to investigate the effects of SKP2 on RIBE induced by irradiated cells. Results: We found a significant negative correlation between SKP2 expression and MN frequency (p < 0.05 induced by RIBE. The results were further confirmed by positive transfection, RNAi, and rescue experiments.γ-H2AX focus formation assay results indicated that overexpression of SKP2 in the irradiated cells inhibited the DNA damage of RIBE cells. However, when SKP2 expression decreased in irradiated cells, the DNA damage of RIBE cells increased. Increased or decreased expression levels of SKP2 had effects on Rad51 expression under the conditions of RIBE. Conclusions: These results showed, for the first time, that SKP2 expression can inhibit RIBE of EC cells. The mechanism may function, at least partly, through the regulation of Rad51 in the ability to repair DNA damage.

  19. VCC-1 over-expression inhibits cisplatin-induced apoptosis in HepG2 cells

    International Nuclear Information System (INIS)

    Zhou, Zhitao; Lu, Xiao; Zhu, Ping; Zhu, Wei; Mu, Xia; Qu, Rongmei; Li, Ming

    2012-01-01

    Highlights: ► VCC-1 is hypothesized to be associated with carcinogenesis. ► Levels of VCC-1 are increased significantly in HCC. ► Over-expression of VCC-1 could promotes cellular proliferation rate. ► Over-expression of VCC-1 inhibit the cisplatin-provoked apoptosis in HepG2 cells. ► VCC-1 plays an important role in control the tumor growth and apoptosis. -- Abstract: Vascular endothelial growth factor-correlated chemokine 1 (VCC-1), a recently described chemokine, is hypothesized to be associated with carcinogenesis. However, the molecular mechanisms by which aberrant VCC-1 expression determines poor outcomes of cancers are unknown. In this study, we found that VCC-1 was highly expressed in hepatocellular carcinoma (HCC) tissue. It was also associated with proliferation of HepG2 cells, and inhibition of cisplatin-induced apoptosis of HepG2 cells. Conversely, down-regulation of VCC-1 in HepG2 cells increased cisplatin-induced apoptosis of HepG2 cells. In summary, these results suggest that VCC-1 is involved in cisplatin-induced apoptosis of HepG2 cells, and also provides some evidence for VCC-1 as a potential cellular target for chemotherapy.

  20. Thromboxane synthase suppression induces lung cancer cell apoptosis via inhibiting NF-κB

    International Nuclear Information System (INIS)

    Leung, Kin Chung; Li, Ming-Yue; Leung, Billy C.S.; Hsin, Michael K.Y.; Mok, Tony S.K.; Underwood, Malcolm J.; Chen, George G.

    2010-01-01

    Accumulating evidence shows that the inhibition of thromboxane synthase (TXS) induced apoptosis in cancer cells. TXS inhibitor 1-Benzylimidzole (1-BI) can trigger apoptosis in lung cancer cells but the mechanism is not fully defined. In this study, lung cancer cells were treated with 1-BI. In this study, the level of reactive oxygen species (ROS) was measured and NF-κB activity was determined in human lung cancer cells. The roles of ROS and NF-κB in 1-BI-mediated cell death were analyzed. The results showed that 1-BI induced ROS generation but decreased the activity of NF-κB by reducing phosphorylated IκBα (p-IκBα) and inhibiting the translocation of p65 into the nucleus. In contrast to 1-BI, antioxidant N-acetyl cysteine (NAC) stimulated cell proliferation and significantly protected the cells from 1-BI-mediated cell death by neutralizing ROS. Collectively, apoptosis induced by 1-BI is associated with the over-production of ROS and the reduction of NF-κB. Antioxidants can significantly block the inhibitory effect of 1-BI.

  1. RNCR3 knockdown inhibits diabetes mellitus-induced retinal reactive gliosis

    International Nuclear Information System (INIS)

    Liu, Chang; Li, Chao-peng; Wang, Jia-Jian; Shan, Kun; Liu, Xin; Yan, Biao

    2016-01-01

    Retinal reactive gliosis is an important pathological feature of diabetic retinopathy. Identifying the underlying mechanisms causing reactive gliosis will be important for developing new therapeutic strategies for treating diabetic retinopathy. Herein, we show that long noncoding RNA-RNCR3 knockdown significantly inhibits retinal reactive gliosis. RNCR3 knockdown leads to a marked reduction in the release of several cytokines. RNCR3 knockdown alleviates diabetes mellitus-induced retinal neurodegeneration, as shown by less apoptotic retinal cells and ameliorative visual function. RNCR3 knockdown could also decrease Müller glial cell viability and proliferation, and reduce the expression of glial reactivity-related genes including GFAP and vimentin in vitro. Collectively, this study shows that RNCR3 knockdown may be a promising strategy for the prevention of diabetes mellitus-induced retinal neurodegeneration. - Highlights: • RNCR3 knockdown inhibits retinal reactive gliosis. • RNCR3 knockdown causes a significant change in cytokine profile. • RNCR3 knockdown alleviates diabetes mellitus-induced retinal neurodegeneration. • RNCR3 knockdown affects Müller glial cell function in vitro.

  2. Salinomycin inhibits proliferation and induces apoptosis of human nasopharyngeal carcinoma cell in vitro and suppresses tumor growth in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Danxin; Zhang, Yu; Huang, Jie; Fan, Zirong; Shi, Fengrong; Wang, Senming, E-mail: wsenming@126.com

    2014-01-10

    Highlight: •We first evaluated the effect of salinomycin on nasopharyngeal carcinoma (NPC). •Salinomycin could inhibit Wnt/β-catenin signaling and induce apoptosis in NPC. •So salinomycin may be a good potential candidate for the chemotherapy of NPC. -- Abstract: Salinomycin (Sal) is a polyether ionophore antibiotic that has recently been shown to induce cell death in various human cancer cells. However, whether salinomycin plays a functional role in nasopharyngeal carcinoma (NPC) has not been determined to date. The present study investigated the chemotherapeutic efficacy of salinomycin and its molecular mechanisms of action in NPC cells. Salinomycin efficiently inhibited proliferation and invasion of 3 NPC cell lines (CNE-1, CNE-2, and CNE-2/DDP) and activated a extensive apoptotic process that is accompanied by activation of caspase-3 and caspase-9, and decreased mitochondrial membrane potential. Meanwhile, the protein expression level of the Wnt coreceptor lipoprotein receptor related protein 6 (LRP6) and β-catenin was down-regulated, which showed that the Wnt/β-catenin signaling was involved in salinomycin-induced apoptosis of NPC cells. In a nude mouse NPC xenograft model, the anti-tumor effect of salinomycin was associated with the downregulation of β-catenin expression. The present study demonstrated that salinomycin can effectively inhibit proliferation and invasion, and induce apoptosis of NPC cells in vitro and inhibit tumor growth in vivo, probably via the inhibition of Wnt/β-catenin signaling, suggesting salinomycin as a potential candidate for the chemotherapy of NPC.

  3. Nec-1 Enhances Shikonin-Induced Apoptosis in Leukemia Cells by Inhibition of RIP-1 and ERK1/2

    Directory of Open Access Journals (Sweden)

    Hongming Pan

    2012-06-01

    Full Text Available Necrostatin-1 (Nec-1 inhibits necroptosis by allosterically inhibiting the kinase activity of receptor-interacting protein 1 (RIP1, which plays a critical role in necroptosis. RIP1 is a crucial adaptor kinase involved in the activation of NF-κB, production of reactive oxygen species (ROS and the phosphorylation of mitogen activated protein kinases (MAPKs. NF-κB, ROS and MAPKs all play important roles in apoptotic signaling. Nec-1 was regarded as having no effect on apoptosis. Here, we report that Nec-1 increased the rate of nuclear condensation and caspases activation induced by a low concentration of shikonin (SHK in HL60, K562 and primary leukemia cells. siRNA-mediated knockdown of RIP1 significantly enhanced shikonin-induced apoptosis in K562 and HL60 cells. Shikonin treatment alone could slightly inhibit the phosphorylation of ERK1/2 in leukemia cells, and the inhibitory effect on ERK1/2 was significantly augmented by Nec-1. We also found that Nec-1 could inhibit NF-κB p65 translocation to the nucleus at a later stage of SHK treatment. In conclusion, we found that Nec-1 can promote shikonin-induced apoptosis in leukemia cells. The mechanism by which Nec-1 sensitizes shikonin-induced apoptosis appears to be the inhibition of RIP1 kinase-dependent phosphorylation of ERK1/2. To our knowledge, this is the first study to document Nec-1 sensitizes cancer cells to apoptosis.

  4. Shigella entry unveils a calcium/calpain-dependent mechanism for inhibiting sumoylation

    Science.gov (United States)

    Lhocine, Nouara; Andrieux, Alexandra; Nigro, Giulia; Mounier, Joëlle

    2017-01-01

    Disruption of the sumoylation/desumoylation equilibrium is associated with several disease states such as cancer and infections, however the mechanisms regulating the global SUMO balance remain poorly defined. Here, we show that infection by Shigella flexneri, the causative agent of human bacillary dysentery, switches off host sumoylation during epithelial cell infection in vitro and in vivo and that this effect is mainly mediated by a calcium/calpain-induced cleavage of the SUMO E1 enzyme SAE2, thus leading to sumoylation inhibition. Furthermore, we describe a mechanism by which Shigella promotes its own invasion by altering the sumoylation state of RhoGDIα, a master negative regulator of RhoGTPase activity and actin polymerization. Together, our data suggest that SUMO modification is essential to restrain pathogenic bacterial entry by limiting cytoskeletal rearrangement induced by bacterial effectors. Moreover, these findings identify calcium-activated calpains as powerful modulators of cellular sumoylation levels with potentially broad implications in several physiological and pathological situations. PMID:29231810

  5. The ovarian DNA damage repair response is induced prior to phosphoramide mustard-induced follicle depletion, and ataxia telangiectasia mutated inhibition prevents PM-induced follicle depletion

    Energy Technology Data Exchange (ETDEWEB)

    Ganesan, Shanthi, E-mail: shanthig@iastate.edu; Keating, Aileen F., E-mail: akeating@iastate.edu

    2016-02-01

    Phosphoramide mustard (PM) is an ovotoxic metabolite of cyclophosphamide and destroys primordial and primary follicles potentially by DNA damage induction. The temporal pattern by which PM induces DNA damage and initiation of the ovarian response to DNA damage has not yet been well characterized. This study investigated DNA damage initiation, the DNA repair response, as well as induction of follicular demise using a neonatal rat ovarian culture system. Additionally, to delineate specific mechanisms involved in the ovarian response to PM exposure, utility was made of PKC delta (PKCδ) deficient mice as well as an ATM inhibitor (KU 55933; AI). Fisher 344 PND4 rat ovaries were cultured for 12, 24, 48 or 96 h in medium containing DMSO ± 60 μM PM or KU 55933 (48 h; 10 nM). PM-induced activation of DNA damage repair genes was observed as early as 12 h post-exposure. ATM, PARP1, E2F7, P73 and CASP3 abundance were increased but RAD51 and BCL2 protein decreased after 96 h of PM exposure. PKCδ deficiency reduced numbers of all follicular stages, but did not have an additive impact on PM-induced ovotoxicity. ATM inhibition protected all follicle stages from PM-induced depletion. In conclusion, the ovarian DNA damage repair response is active post-PM exposure, supporting that DNA damage contributes to PM-induced ovotoxicity. - Highlights: • PM exposure induces DNA damage repair gene expression. • Inhibition of ATM prevented PM-induced follicle depletion. • PKCδ deficiency did not impact PM-induced ovotoxicity.

  6. Astaxanthin Attenuates Homocysteine-Induced Cardiotoxicity in Vitro and in Vivo by Inhibiting Mitochondrial Dysfunction and Oxidative Damage

    Directory of Open Access Journals (Sweden)

    Cun-dong Fan

    2017-12-01

    Full Text Available Homocysteine (Hcy as an independent risk factor contributes to the occurrence and development of human cardiovascular diseases (CVD. Induction of oxidative stress and apoptosis was commonly accepted as the major mechanism in Hcy-induced cardiotoxicity. Astaxanthin (ATX as one of the most powerful antioxidants exhibits novel cardioprotective potential against Hcy-induced endothelial dysfunction. However, the protective effect and mechanism of ATX against Hcy-induced cardiotoxicity in cardiomyocytes have not been elucidated yet. Herein, H9c2 rat cardiomyocytes and Hcy-injured animal model were employed in the present study. The MTT, flow cytometry analysis (FCM, TUNEL-DAPI and western blotting results all demonstrated that ATX significantly alleviated Hcy-induced cytotoxicity in H9c2 cells through inhibition of mitochondria-mediated apoptosis. The JC-1 and Mito-tracker staining both revealed that ATX pre-treatment blocked Hcy-induced mitochondrial dysfunction by regulating Bcl-2 family expression. Moreover, DCFH-DA and Mito-SOX staining showed that ATX effectively attenuated Hcy-induced oxidative damage via scavenging intracellular reactive oxygen species (ROS. Importantly, the ELISA and immunohistochemical results indicated that Hcy-induced cardiotoxicity in vivo was also significantly inhibited by ATX through inhibition of oxidative damage and apoptosis, and improvement of the angiogenesis. Taken together, our results demonstrated that ATX suppressed Hcy-induced cardiotoxicity in vitro and in vivo by inhibiting mitochondrial dysfunction and oxidative damage. Our findings validated the strategy of using ATX may be a highly efficient way to combat Hcy-mediated human CVD.

  7. Astaxanthin Attenuates Homocysteine-Induced Cardiotoxicity in Vitro and in Vivo by Inhibiting Mitochondrial Dysfunction and Oxidative Damage.

    Science.gov (United States)

    Fan, Cun-Dong; Sun, Jing-Yi; Fu, Xiao-Ting; Hou, Ya-Jun; Li, Yuan; Yang, Ming-Feng; Fu, Xiao-Yan; Sun, Bao-Liang

    2017-01-01

    Homocysteine (Hcy) as an independent risk factor contributes to the occurrence and development of human cardiovascular diseases (CVD). Induction of oxidative stress and apoptosis was commonly accepted as the major mechanism in Hcy-induced cardiotoxicity. Astaxanthin (ATX) as one of the most powerful antioxidants exhibits novel cardioprotective potential against Hcy-induced endothelial dysfunction. However, the protective effect and mechanism of ATX against Hcy-induced cardiotoxicity in cardiomyocytes have not been elucidated yet. Herein, H9c2 rat cardiomyocytes and Hcy-injured animal model were employed in the present study. The MTT, flow cytometry analysis (FCM), TUNEL-DAPI and western blotting results all demonstrated that ATX significantly alleviated Hcy-induced cytotoxicity in H9c2 cells through inhibition of mitochondria-mediated apoptosis. The JC-1 and Mito-tracker staining both revealed that ATX pre-treatment blocked Hcy-induced mitochondrial dysfunction by regulating Bcl-2 family expression. Moreover, DCFH-DA and Mito-SOX staining showed that ATX effectively attenuated Hcy-induced oxidative damage via scavenging intracellular reactive oxygen species (ROS). Importantly, the ELISA and immunohistochemical results indicated that Hcy-induced cardiotoxicity in vivo was also significantly inhibited by ATX through inhibition of oxidative damage and apoptosis, and improvement of the angiogenesis. Taken together, our results demonstrated that ATX suppressed Hcy-induced cardiotoxicity in vitro and in vivo by inhibiting mitochondrial dysfunction and oxidative damage. Our findings validated the strategy of using ATX may be a highly efficient way to combat Hcy-mediated human CVD.

  8. Inhibition of IRAK-4 activity for rescuing endotoxin LPS-induced septic mortality in mice by lonicerae flos extract

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sun Hong; Roh, Eunmiri [College of Pharmacy, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Kim, Hyun Soo [Pharmaceutical R and D Center, Huons Co., Ltd., Anyang (Korea, Republic of); Baek, Seung-Il [College of Pharmacy, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Choi, Nam Song [Pharmaceutical R and D Center, Huons Co., Ltd., Anyang (Korea, Republic of); Kim, Narae; Hwang, Bang Yeon; Han, Sang-Bae [College of Pharmacy, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Kim, Youngsoo, E-mail: youngsoo@chungbuk.ac.kr [College of Pharmacy, Chungbuk National University, Cheongju 361-763 (Korea, Republic of)

    2013-12-13

    Highlights: •Lonicerae flos extract (HS-23) is a clinical candidate, Phase I for sepsis treatment. •Here, HS-23 or its major constituents rescued LPS-induced septic mortality in mice. •As a mechanism, they directly inhibited IRAK-4-catalyzed kinase activity. •Thus, they suppressed LPS-induced expression of NF-κB/AP-1-target inflammatory genes. -- Abstract: Lonicerae flos extract (HS-23) is a clinical candidate currently undergoing Phase I trial in lipopolysaccharide (LPS)-injected healthy human volunteers, but its molecular basis remains to be defined. Here, we investigated protective effects of HS-23 or its major constituents on Escherichia coli LPS-induced septic mortality in mice. Intravenous treatment with HS-23 rescued LPS-intoxicated C57BL/6J mice under septic conditions, and decreased the levels of cytokines such as tumor necrosis factor α (TNF-α), interleukin (IL)-1β and high-mobility group box-1 (HMGB-1) in the blood. Chlorogenic acid (CGA) and its isomers were assigned as major constituents of HS-23 in the protection against endotoxemia. As a molecular mechanism, HS-23 or CGA isomers inhibited endotoxin LPS-induced autophosphorylation of the IL-1 receptor-associated kinase 4 (IRAK-4) in mouse peritoneal macrophages as well as the kinase activity of IRAK-4 in cell-free reactions. HS-23 consequently suppressed downstream pathways critical for LPS-induced activation of nuclear factor (NF)-κB or activating protein 1 (AP-1) in the peritoneal macrophages. HS-23 also inhibited various toll-like receptor agonists-induced nitric oxide (NO) production, and down-regulated LPS-induced expression of NF-κB/AP-1-target inflammatory genes in the cells. Taken together, HS-23 or CGA isomers exhibited anti-inflammatory therapy against LPS-induced septic mortality in mice, at least in part, mediated through the inhibition of IRAK-4.

  9. Exogenous nitrate induces root branching and inhibits primary root growth in Capsicum chinense Jacq.

    Science.gov (United States)

    Celis-Arámburo, Teresita de Jesús; Carrillo-Pech, Mildred; Castro-Concha, Lizbeth A; Miranda-Ham, María de Lourdes; Martínez-Estévez, Manuel; Echevarría-Machado, Ileana

    2011-12-01

    The effects of nitrate (NO₃⁻) on the root system are complex and depend on several factors, such as the concentration available to the plant, endogenous nitrogen status and the sensitivity of the species. Though these effects have been widely documented on Arabidopsis and cereals, no reports are available in the Capsicum genus. In this paper, we have determined the effect of an exogenous in vitro application of this nutrient on root growth in habanero pepper (Capsicum chinense Jacq.). Exposure to NO₃⁻ inhibited primary root growth in both, dose- and time-dependent manners. The highest inhibition was attained with 0.1 mM NO₃⁻ between the fourth and fifth days of treatment. Inhibition of primary root growth was observed by exposing the root to both homogeneous and heterogeneous conditions of the nutrient; in contrast, ammonium was not able to induce similar changes. NO₃⁻-induced inhibition of primary root growth was reversed by treating the roots with IAA or NPA, a polar auxin transport inhibitor. Heterogeneous NO₃⁻ application stimulated the formation and elongation of lateral roots in the segment where the nutrient was present, and this response was influenced by exogenous phytohormones. These results demonstrate that habanero pepper responds to NO₃⁻ in a similar fashion to other species with certain particular differences. Therefore, studies in this model could help to elucidate the mechanisms by which roots respond to NO₃⁻ in fluctuating soil environments. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  10. Docosahexaenoic acid inhibits monocrotaline-induced pulmonary hypertension via attenuating endoplasmic reticulum stress and inflammation.

    Science.gov (United States)

    Chen, Rui; Zhong, Wei; Shao, Chen; Liu, Peijing; Wang, Cuiping; Wang, Zhongqun; Jiang, Meiping; Lu, Yi; Yan, Jinchuan

    2018-02-01

    Endoplasmic reticulum (ER) stress and inflammation contribute to pulmonary hypertension (PH) pathogenesis. Previously, we confirmed that docosahexaenoic acid (DHA) could improve hypoxia-induced PH. However, little is known about the link between DHA and monocrotaline (MCT)-induced PH. Our aims were, therefore, to evaluate the effects and molecular mechanisms of DHA on MCT-induced PH in rats. Rat PH was induced by MCT. Rats were treated with DHA daily in the prevention group (following MCT injection) and the reversal group (after MCT injection for 2 wk) by gavage. After 4 wk, mean pulmonary arterial pressure (mPAP), right ventricular (RV) hypertrophy index, and morphological and immunohistochemical analyses were evaluated. Rat pulmonary artery smooth muscle cells (PASMCs) were used to investigate the effects of DHA on cell proliferation stimulated by platelet-derived growth factor (PDGF)-BB. DHA decreased mPAP and attenuated pulmonary vascular remodeling and RV hypertrophy, which were associated with suppressed ER stress. DHA blocked the mitogenic effect of PDGF-BB on PASMCs and arrested the cell cycle via inhibiting nuclear factor of activated T cells-1 (NFATc1) expression and activation and regulating cell cycle-related proteins. Moreover, DHA ameliorated inflammation in lung and suppressed macrophage and T lymphocyte accumulation in lung and adventitia of resistance pulmonary arteries. These findings suggest that DHA could protect against MCT-induced PH by reducing ER stress, suppressing cell proliferation and inflammation.

  11. Inhibition of lipopolysaccharide induced acute inflammation in lung by chlorination

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jinshan; Xue, Jinling; Xu, Bi; Xie, Jiani [Environmental Simulation and Pollution Control State Key Joint Laboratory, School of Environment, Tsinghua University, Beijing 100084 (China); Qiao, Juan, E-mail: qjuan@tsinghua.edu.cn [Department of Chemistry, Tsinghua University, Beijing 100084 (China); Lu, Yun, E-mail: luyun@tsinghua.edu.cn [Environmental Simulation and Pollution Control State Key Joint Laboratory, School of Environment, Tsinghua University, Beijing 100084 (China)

    2016-02-13

    Highlights: • Chlorination is effective to reduce the inflammation inducing capacity of LPS in lung. • LAL-detected endotoxin activity is not correlated to the potency of inflammation induction. • Alkyl chain of LPS was chlorinated in chlorination process. • LPS aggregate size decreases after chlorination. - Abstract: Lipopolysaccharide (LPS, also called endotoxin) is a pro-inflammatory constituent of gram negative bacteria and cyanobacteria, which causes a potential health risk in the process of routine urban application of reclaimed water, such as car wash, irrigation, scenic water refilling, etc. Previous studies indicated that the common disinfection treatment, chlorination, has little effect on endotoxin activity removal measured by Limulus amebocyte lysate (LAL) assay. However, in this study, significant decrease of acute inflammatory effects was observed in mouse lung, while LAL assay still presented a moderate increase of endotoxin activity. To explore the possible mechanisms, the nuclear magnetic resonance (NMR) results showed the chlorination happened in alkyl chain of LPS molecules, which could affect the interaction between LPS and LPS-binding protein. Also the size of LPS aggregates was found to drop significantly after treatment, which could be another results of chlorination caused polarity change. In conclusion, our observation demonstrated that chlorination is effective to reduce the LPS induced inflammation in lung, and it is recommended to use health effect-based methods to assess risk removal of water treatment technologies.

  12. Inhibition of lipopolysaccharide induced acute inflammation in lung by chlorination

    International Nuclear Information System (INIS)

    Zhang, Jinshan; Xue, Jinling; Xu, Bi; Xie, Jiani; Qiao, Juan; Lu, Yun

    2016-01-01

    Highlights: • Chlorination is effective to reduce the inflammation inducing capacity of LPS in lung. • LAL-detected endotoxin activity is not correlated to the potency of inflammation induction. • Alkyl chain of LPS was chlorinated in chlorination process. • LPS aggregate size decreases after chlorination. - Abstract: Lipopolysaccharide (LPS, also called endotoxin) is a pro-inflammatory constituent of gram negative bacteria and cyanobacteria, which causes a potential health risk in the process of routine urban application of reclaimed water, such as car wash, irrigation, scenic water refilling, etc. Previous studies indicated that the common disinfection treatment, chlorination, has little effect on endotoxin activity removal measured by Limulus amebocyte lysate (LAL) assay. However, in this study, significant decrease of acute inflammatory effects was observed in mouse lung, while LAL assay still presented a moderate increase of endotoxin activity. To explore the possible mechanisms, the nuclear magnetic resonance (NMR) results showed the chlorination happened in alkyl chain of LPS molecules, which could affect the interaction between LPS and LPS-binding protein. Also the size of LPS aggregates was found to drop significantly after treatment, which could be another results of chlorination caused polarity change. In conclusion, our observation demonstrated that chlorination is effective to reduce the LPS induced inflammation in lung, and it is recommended to use health effect-based methods to assess risk removal of water treatment technologies.

  13. Sertraline inhibits formalin-induced nociception and cardiovascular responses

    Energy Technology Data Exchange (ETDEWEB)

    Santuzzi, C.H. [Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Futuro Neto, H.A. [Departamento de Morfologia, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Escola de Medicina da Empresa Brasileira de Ensino, Pesquisa e Extensão, Vitória, ES (Brazil); Escola Superior de Ciências da Saúde, Santa Casa de Misericórdia de Vitória, Vitória, ES (Brazil); Pires, J.G.P. [Escola de Medicina da Empresa Brasileira de Ensino, Pesquisa e Extensão, Vitória, ES (Brazil); Centro Universitário do Espírito Santo, Colatina, ES (Brazil); Gonçalves, W.L.S. [Centro Universitário do Espírito Santo, Colatina, ES (Brazil); Tiradentes, R.V.; Gouvea, S.A.; Abreu, G.R. [Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil)

    2011-11-18

    The objective of the present study was to determine the antihyperalgesic effect of sertraline, measured indirectly by the changes of sciatic afferent nerve activity, and its effects on cardiorespiratory parameters, using the model of formalin-induced inflammatory nociception in anesthetized rats. Serum serotonin (5-HT) levels were measured in order to test their correlation with the analgesic effect. Male Wistar rats (250-300 g) were divided into 4 groups (N = 8 per group): sertraline-treated group (Sert + Saline (Sal) and Sert + Formalin (Form); 3 mg·kg{sup −1}·day{sup −1}, ip, for 7 days) and saline-treated group (Sal + Sal and Sal + Form). The rats were injected with 5% (50 µL) formalin or saline into the right hind paw. Sciatic nerve activity was recorded using a silver electrode connected to a NeuroLog apparatus, and cardiopulmonary parameters (mean arterial pressure, heart rate and respiratory frequency), assessed after arterial cannulation and tracheotomy, were monitored using a Data Acquisition System. Blood samples were collected from the animals and serum 5-HT levels were determined by ELISA. Formalin injection induced the following changes: sciatic afferent nerve activity (+50.8 ± 14.7%), mean arterial pressure (+1.4 ± 3 mmHg), heart rate (+13 ± 6.8 bpm), respiratory frequency (+4.6 ± 5 cpm) and serum 5-HT increased to 1162 ± 124.6 ng/mL. Treatment with sertraline significantly reduced all these parameters (respectively: +19.8 ± 6.9%, -3.3 ± 2 mmHg, -13.1 ± 10.8 bpm, -9.8 ± 5.7 cpm) and serum 5-HT level dropped to 634 ± 69 ng/mL (P < 0.05). These results suggest that sertraline plays an analgesic role in formalin-induced nociception probably through a serotonergic mechanism.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Bystander effects in UV-induced genomic instability: Antioxidants inhibit delayed mutagenesis induced by ultraviolet A and B radiation

    Directory of Open Access Journals (Sweden)

    Dahle Jostein

    2005-01-01

    glutathione. Previously, we have shown that ultraviolet induced delayed mutations may be induced via a bystander effect and that this effect is 5-fold higher for UVB radiation than for UVA radiation. Therefore, we propose that the antioxidants inhibit an ultraviolet radiation-induced bystander effect and that the effect is transmitted via the medium and via an internal transfer between cells, like gap junctional intercellular communication, for UVB radiation and only by the latter mechanism for UVA radiation.

  16. Go-6976 Reverses Hyperglycemia-Induced Insulin Resistance Independently of cPKC Inhibition in Adipocytes

    Science.gov (United States)

    Robinson, Katherine A.; Hegyi, Krisztina; Hannun, Yusuf A.; Buse, Maria G.; Sethi, Jaswinder K.

    2014-01-01

    Chronic hyperglycemia induces insulin resistance by mechanisms that are incompletely understood. One model of hyperglycemia-induced insulin resistance involves chronic preincubation of adipocytes in the presence of high glucose and low insulin concentrations. We have previously shown that the mTOR complex 1 (mTORC1) plays a partial role in the development of insulin resistance in this model. Here, we demonstrate that treatment with Go-6976, a widely used “specific” inhibitor of cPKCs, alleviates hyperglycemia-induced insulin resistance. However, the effects of mTOR inhibitor, rapamycin and Go-6976 were not additive and only rapamycin restored impaired insulin-stimulated AKT activation. Although, PKCα, (but not –β) was abundantly expressed in these adipocytes, our studies indicate cPKCs do not play a major role in causing insulin-resistance in this model. There was no evidence of changes in the expression or phosphorylation of PKCα, and PKCα knock-down did not prevent the reduction of insulin-stimulated glucose transport. This was also consistent with lack of IRS-1 phosphorylation on Ser-24 in hyperglycemia-induced insulin-resistant adipocytes. Treatment with Go-6976 did inhibit a component of the mTORC1 pathway, as evidenced by decreased phosphorylation of S6 ribosomal protein. Raptor knock-down enhanced the effect of insulin on glucose transport in insulin resistant adipocytes. Go-6976 had the same effect in control cells, but was ineffective in cells with Raptor knock-down. Taken together these findings suggest that Go-6976 exerts its effect in alleviating hyperglycemia-induced insulin-resistance independently of cPKC inhibition and may target components of the mTORC1 signaling pathway. PMID:25330241

  17. Curcumin ameliorates cardiac dysfunction induced by mechanical trauma.

    Science.gov (United States)

    Li, Xintao; Cao, Tingting; Ma, Shuo; Jing, Zehao; Bi, Yue; Zhou, Jicheng; Chen, Chong; Yu, Deqin; Zhu, Liang; Li, Shuzhuang

    2017-11-05

    Curcumin, a phytochemical component derived from turmeric (Carcuma longa), has been extensively investigated because of its anti-inflammatory and anti-oxidative properties. Inflammation and oxidative stress play critical roles in posttraumatic cardiomyocyte apoptosis, which contributes to secondary cardiac dysfunction. This research was designed to identify the protective effect of curcumin on posttraumatic cardiac dysfunction and investigate its underlying mechanism. Noble-Collip drum was used to prepare a mechanical trauma (MT) model of rats, and the hemodynamic responses of traumatized rats were observed by ventricular intubation 12h after trauma. Myocardial apoptosis was determined through terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and caspase-3 activity assay. Tumor necrosis factor-α (TNF-α) and reactive oxygen species (ROS) generated by monocytes and myocardial cells were identified through enzyme-linked immunosorbent assay (ELISA), and the intracellular alteration of Ca 2+ in cardiomyocytes was examined through confocal microscopy. In vivo, curcumin effectively ameliorated MT-induced secondary cardiac dysfunction and significantly decreased the apoptotic indices of the traumatized myocardial cells. In vitro, curcumin inhibited TNF-α production by monocytes and reduced the circulating TNF-α levels. With curcumin pretreatment, ROS production and Ca 2+ overload in H9c2 cells were attenuated when these cells were incubated with traumatic plasma. Therefore, curcumin can effectively ameliorate MT-induced cardiac dysfunction mainly by inhibiting systemic inflammatory responses and by weakening oxidative stress reaction and Ca 2+ overload in cardiomyocytes. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Genetic ablation or chemical inhibition of phosphatidylcholine transfer protein attenuates diet-induced hepatic glucose production.

    Science.gov (United States)

    Shishova, Ekaterina Y; Stoll, Janis M; Ersoy, Baran A; Shrestha, Sudeep; Scapa, Erez F; Li, Yingxia; Niepel, Michele W; Su, Ya; Jelicks, Linda A; Stahl, Gregory L; Glicksman, Marcie A; Gutierrez-Juarez, Roger; Cuny, Gregory D; Cohen, David E

    2011-08-01

    Phosphatidylcholine transfer protein (PC-TP, synonym StARD2) is a highly specific intracellular lipid binding protein that is enriched in liver. Coding region polymorphisms in both humans and mice appear to confer protection against measures of insulin resistance. The current study was designed to test the hypotheses that Pctp-/- mice are protected against diet-induced increases in hepatic glucose production and that small molecule inhibition of PC-TP recapitulates this phenotype. Pctp-/- and wildtype mice were subjected to high-fat feeding and rates of hepatic glucose production and glucose clearance were quantified by hyperinsulinemic euglycemic clamp studies and pyruvate tolerance tests. These studies revealed that high-fat diet-induced increases in hepatic glucose production were markedly attenuated in Pctp-/- mice. Small molecule inhibitors of PC-TP were synthesized and their potencies, as well as mechanism of inhibition, were characterized in vitro. An optimized inhibitor was administered to high-fat-fed mice and used to explore effects on insulin signaling in cell culture systems. Small molecule inhibitors bound PC-TP, displaced phosphatidylcholines from the lipid binding site, and increased the thermal stability of the protein. Administration of the optimized inhibitor to wildtype mice attenuated hepatic glucose production associated with high-fat feeding, but had no activity in Pctp-/- mice. Indicative of a mechanism for reducing glucose intolerance that is distinct from commonly utilized insulin-sensitizing agents, the inhibitor promoted insulin-independent phosphorylation of key insulin signaling molecules. These findings suggest PC-TP inhibition as a novel therapeutic strategy in the management of hepatic insulin resistance. Copyright © 2011 American Association for the Study of Liver Diseases.

  19. Partial protection from organophosphate-induced cholinesterase inhibition by metyrapone treatment

    Directory of Open Access Journals (Sweden)

    Radosław Świercz

    2013-08-01

    Full Text Available Background: Organophosphates are cholinesterase (ChE inhibitors with worldwide use as insecticides. Stress response, evidenced by a dramatic and relatively long-lasting (several hours rise in the plasma glucocorticoid concentration is an integral element of the organophosphate (OP poisoning symptomatology. In rodents, corticosterone (CORT is the main glucocorticoid. There are several reports suggesting a relationship between the stressor-induced rise in CORT concentraion (the CORT response and the activity of the cerebral and peripheral ChE. Thus, it seems reasonable to presume that, in OP intoxication, the rise in plasma CORT concentration may somehow affect the magnitude of the OP-induced ChE inhibition. Metyrapone (MET [2-methyl-1,2-di(pyridin-3-ylpropan-1-one] blocks CORT synthesis by inhibiting steoid 11β-hydroxylase, thereby preventing the CORT response. Chlorfenvinphos (CVP [2-chloro-1-(2,4-dichlorophenyl ethenyl diethyl phosphate] is an organophosphate insecticide still in use in some countries. Material and Methods: The purose of the present work was to compare the CVP-induced effects - the rise of the plasma CORT concentration and the reduction in ChE activity - in MET-treated and MET-untreated rats. Chlorfenvinphos was administered once at 0.0, 0.5, 1.0 and 3.0 mg/kg i.p. Metyrapone, at 100 mg/kg i.p., was administered five times, at 24-h intervals. The first MET dose was given two hours before CVP. Conclusion: The following was observed in the MET-treated rats: i no rise in plasma CORT concentration after the CVP administration, ii a reduced inhibition and a faster restitution of blood and brain ChE activities. The results suggest that MET treatment may confer significant protection against at least some effects of OP poisoning. The likely mechanism of the protective MET action has been discussed.

  20. Andrographolide Inhibits Oxidized LDL-Induced Cholesterol Accumulation and Foam Cell Formation in Macrophages.

    Science.gov (United States)

    Lin, Hung-Chih; Lii, Chong-Kuei; Chen, Hui-Chun; Lin, Ai-Hsuan; Yang, Ya-Chen; Chen, Haw-Wen

    2018-01-01

    oxLDL is involved in the pathogenesis of atherosclerotic lesions through cholesterol accumulation in macrophage foam cells. Andrographolide, the bioactive component of Andrographis paniculata, possesses several biological activities such as anti-inflammatory, anti-oxidant, and anticancer functions. Scavenger receptors (SRs), including class A SR (SR-A) and CD36, are responsible for the internalization of oxLDL. In contrast, receptors for reverse cholesterol transport, including ABCA1 and ABCG1, mediate the efflux of cholesterol from macrophage foam cells. Transcription factor liver X receptor [Formula: see text] (LXR[Formula: see text] plays a key role in lipid metabolism and inflammation as well as in the regulation of ABCA1 and ABCG1 expression. Because of the contribution of inflammation to macrophage foam cell formation and the potent anti-inflammatory activity of andrographolide, we hypothesized that andrographolide might inhibit oxLDL-induced macrophage foam cell formation. The results showed that andrographolide reduced oxLDL-induced lipid accumulation in macrophage foam cells. Andrographolide decreased the mRNA and protein expression of CD36 by inducing the degradation of CD36 mRNA; however, andrographolide had no effect on SR-A expression. In contrast, andrographolide increased the mRNA and protein expression of ABCA1 and ABCG1, which were dependent on LXR[Formula: see text]. Andrographolide enhanced LXR[Formula: see text] nuclear translocation and DNA binding activity. Treatment with the LXR[Formula: see text] antagonist GGPP and transfection with LXR[Formula: see text] siRNA reversed the ability of andrographolide to stimulate ABCA1 and ABCG1 protein expression. In conclusion, inhibition of CD36-mediated oxLDL uptake and induction of ABCA1- and ABCG1-dependent cholesterol efflux are two working mechanisms by which andrographolide inhibits macrophage foam cell formation, which suggests that andrographolide could be a potential candidate to prevent

  1. Minocycline inhibits alkali burn-induced corneal neovascularization in mice.

    Directory of Open Access Journals (Sweden)

    Ou Xiao

    Full Text Available The purpose of this study was to investigate the effects of minocycline on alkali burn-induced corneal neovascularization (CNV. A total of 105 mice treated with alkali burns were randomly divided into three groups to receive intraperitoneal injections of either phosphate buffered saline (PBS or minocycline twice a day (60 mg/kg or 30 mg/kg for 14 consecutive days. The area of CNV and corneal epithelial defects was measured on day 4, 7, 10, and14 after alkali burns. On day 14, a histopathological examination was performed to assess morphological change and the infiltration of polymorphonuclear neutrophils (PMNs. The mRNA expression levels of vascular endothelial growth factor (VEGF and its receptors (VEGFRs, basic fibroblast growth factor (bFGF, matrix metalloproteinases (MMPs, interleukin-1α, 1β, 6 (IL-1α, IL-1β, IL-6 were analyzed using real-time quantitative polymerase chain reaction. The expression of MMP-2 and MMP-9 proteins was determined by gelatin zymography. In addition, enzyme-linked immunosorbent assay was used to analyze the protein levels of VEGFR1, VEGFR2, IL-1β and IL-6. Minocycline at a dose of 60 mg/kg or 30 mg/kg significantly enhanced the recovery of the corneal epithelial defects more than PBS did. There were significant decreases of corneal neovascularization in the group of high-dosage minocycline compared with the control group at all checkpoints. On day 14, the infiltrated PMNs was reduced, and the mRNA expression of VEGFR1, VEGFR2, bFGF, IL-1β, IL-6, MMP-2, MMP-9, -13 as well as the protein expression of VEGFR2, MMP-2, -9, IL-1β, IL-6 in the corneas were down-regulated with the use of 60 mg/kg minocycline twice a day. Our results showed that the intraperitoneal injection of minocycline (60 mg/kg b.i.d. can significantly inhibit alkali burn-induced corneal neovascularization in mice, possibly by accelerating corneal wound healing and by reducing the production of angiogenic factors, inflammatory cytokines and MMPs.

  2. Contribution of adrenal hormones to nicotine-induced inhibition of synovial plasma extravasation in the rat.

    Science.gov (United States)

    Miao, F J; Benowitz, N L; Heller, P H; Levine, J D

    1997-01-01

    1. In this study, we examined the mechanism(s) by which s.c. nicotine inhibits synovial plasma extravasation. We found that nicotine dose-dependently inhibited bradykinin (BK)- and platelet activating factor (PAF)-induced plasma extravasation. 2. The effect of nicotine on both BK- and PAF-induced plasma extravasation was attenuated by adrenal medullectomy. ICI-118,551 (a selective beta 2-adrenoceptor blocker) (30 micrograms ml-1, intra-articularly) significantly attenuated the inhibitory action of high-dose (1 mg kg-1) nicotine on BK-induced plasma extravasation without affecting the inhibition by low- (0.01 microgram kg-1) dose nicotine or that on PAF-induced plasma extravasation by nicotine at any dose. This suggested that beta 2-adrenoceptors mediate the inhibitory actions of high-dose, but not low-dose, nicotine. We also found that systemic naloxone (an opioid receptor antagonist) (two hourly injections of 1 mg kg-1, i.p.) attenuated the inhibitory action produced by all doses of nicotine on BK- or PAF-induced plasma extravasation, suggesting the contribution of endogenous opioids. 3. RU-38,486 (a glucocorticoid receptor antagonist) (30 mg kg-1, s.c.), and metyrapone (a glucocorticoid synthesis inhibitor) (two hourly injections of 100 mg kg-1, i.p.) both attenuated the action of high-dose nicotine without affecting that of low-dose nicotine. 4. Spinal mecamylamine (a nicotinic receptor antagonist) (0.025 mg kg-1, intrathecally, i.t.) attenuated the action of high-dose, but not low-dose, nicotine, suggesting that part of the action of high-dose nicotine is mediated by spinal nicotinic receptors. 5. Combined treatment with ICI-118,551, naloxone and RU-38,486 attenuated the action of low-dose nicotine by an amount similar to that produced by naloxone alone but produced significantly greater attenuation of the effect of high-dose nicotine when compared to the action of any of the three antagonists alone.

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

    Science.gov (United States)

    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.

  4. Ranolazine attenuation of CFA-induced mechanical hyperalgesia.

    Science.gov (United States)

    Casey, Gregory P; Roberts, Jomar S; Paul, Dennis; Diamond, Ivan; Gould, Harry J

    2010-01-01

    To determine whether ranolazine, a new anti-angina medication, could be an effective analgesic agent in complete Freund's adjuvant-induced inflammatory pain. Plantar injection of complete Freund's adjuvant (CFA) produces an extended period of hyperalgesia that is associated with a dramatic up-regulation of Na(v) 1.7 sodium channels in populations of large and small dorsal root ganglion neurons related to the injection site. Ranolazine appears to produce its anti-angina effect through blocking the late sodium current associated with the voltage-gated sodium channel, Na(v) 1.5. Because ranolazine also inhibits Na(v) 1.7, and 1.8, we sought to determine whether it could be an effective analgesic agent in CFA-induced inflammatory pain. Baseline determinations of withdrawal from thermal and mechanical stimulation were made in Sprague-Dawley rats ( approximately 300-350 x g). Following determination of baseline, one hindpaw in each group was injected with 0.1 mL of CFA. The contralateral paw received saline. Thermal and mechanical stimulation was repeated on the third day post-injection. Vehicle (0.9% isotonic saline; pH 3.0) or ranolazine was then administered in randomized and blinded doses either by intraperitoneal (ip) injection (0, 10, 20, and 50 mg/kg) or by oral gavage (po; 0, 20, 50, 100, and 200 mg/kg). Animals were again tested 30 minutes (ip) and 1 hour (po) after drug administration. Ranolazine produced dose-dependant analgesia on mechanical allodynia induced by CFA injection, but had no effect on thermal hyperalgesia. Ranolazine's potential as a new option for managing both angina and chronic inflammatory pain warrants further study.

  5. Rapid Inhibition Profiling in Bacillus subtilis to Identify the Mechanism of Action of New Antimicrobials.

    Science.gov (United States)

    Lamsa, Anne; Lopez-Garrido, Javier; Quach, Diana; Riley, Eammon P; Pogliano, Joe; Pogliano, Kit

    2016-08-19

    Increasing antimicrobial resistance has become a major public health crisis. New antimicrobials with novel mechanisms of action (MOA) are desperately needed. We previously developed a method, bacterial cytological profiling (BCP), which utilizes fluorescence microscopy to rapidly identify the MOA of antimicrobial compounds. BCP is based upon our discovery that cells treated with antibiotics affecting different metabolic pathways generate different cytological signatures, providing quantitative information that can be used to determine a compound's MOA. Here, we describe a system, rapid inhibition profiling (RIP), for creating cytological profiles of new antibiotic targets for which there are currently no chemical inhibitors. RIP consists of the fast, inducible degradation of a target protein followed by BCP. We demonstrate that degrading essential proteins in the major metabolic pathways for DNA replication, transcription, fatty acid biosynthesis, and peptidoglycan biogenesis in Bacillus subtilis rapidly produces cytological profiles closely matching that of antimicrobials targeting the same pathways. Additionally, RIP and antibiotics targeting different steps in fatty acid biosynthesis can be differentiated from each other. We utilize RIP and BCP to show that the antibacterial MOA of four nonsteroidal anti-inflammatory antibiotics differs from that proposed based on in vitro data. RIP is a versatile method that will extend our knowledge of phenotypes associated with inactivating essential bacterial enzymes and thereby allow for screening for molecules that inhibit novel essential targets.

  6. Mechanisms of Proliferative Inhibition by Maimendong & Qianjinweijing Decoction in A549 Cells

    Directory of Open Access Journals (Sweden)

    Xu ZHANG

    2010-05-01

    Full Text Available Background and objective Traditional Chinese medicine is an approach for malignant tumor treatment with Chinese characteristics. The aim of this study is to investigate the inhibitory effects of Maimendong & qianjinweijing decoction extract on A549 human lung cancer cell line proliferation and explored its probable molecular mechanisms. Methods A549 cells were treated with drugs in different does and time. The effects on the proliferation of A549 cells were detected by MTT assay and clonogenic assay in vitro. Cell cycle was analyzed by flow cytometry. Morphological changes of the apoptosis of cancer cells were observed by Hochest 33258 staining. Western blot was performed to detect apoptosis-related gene expression. Results Ethyl acetate extract inhibited the growth of A549 cells but not in HFL-1 cells. Compared with controls, administration of 10 μg/mL ethyl acetate extract resulted in 73.86% decrease in colony formation (P < 0.01, apoptotic rates of 33.86% (P < 0.01, and morphological changes of apoptosis in A549 cells. The expression of anti-apoptotic protein EGFR and ERK were significantly down-regulated (P < 0.01. Conclusion Ethyl acetate extract might inhibit proliferation and induce apoptosis in A549 cells via downregulation of EGFR/ERK signal transduction pathway. Therefore, ethyl acetate extract should be further separated in order to identify the material fundamentals on anti-cancer effect.

  7. Different inhibition mechanisms of gentisic acid and cyaniding-3-O-glucoside on polyphenoloxidase.

    Science.gov (United States)

    Zhou, Lei; Xiong, Zhiqiang; Liu, Wei; Zou, Liqiang

    2017-11-01

    Gentisic acid and cyanidin-3-O-glucoside are important bioactive polyphenols which are widely distributed in many fruits and cereals. In this work, kinetic study, spectral analysis and computational simulation were used to compare the inhibitory effects and inhibition mechanisms of gentisic acid and cyanidin-3-O-glucoside on mushroom polyphenoloxidase (PPO). The inhibitory effect of cyanidin-3-O-glucoside on PPO was much stronger than that of gentisic acid. Gentisic acid inhibited PPO in a reversible mixed-type manner while cyanidin-3-O-glucoside was an irreversible inhibitor. Gentisic acid and cyanidin-3-O-glucoside made the thermal inactivation of PPO easier, and induced apparent conformational changes of PPO. Compared with gentisic acid, cyanidin-3-O-glucoside had stronger effects on the thermal inactivation and conformation of PPO. Molecular docking results revealed gentisic acid bound to the active site of PPO by hydrogen bonding, π-π stacking and van der Waals forces. However, cyanidin-3-O-glucoside might irreversibly interact with the Met or Cys in PPO by covalent bonds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Gingival tissue-produced inhibition of platelet aggregation and the loss of inhibition in streptozotocin-induced diabetic rats

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, Keiichiroh; Tamai, Kazuharu; Shirakawa, Masaharu; Okamoto, Hiroshi; Dohi, Toshihiro; Tsujimoto, Akira

    1988-01-01

    Addition of medium incubated with normal rat gingival tissue to platelet-rich plasma inhibited ADP-induced platelet aggregation. The ability of rat gingiva to produce activity inhibiting platelet aggregation was enhanced by the addition of arachidonic acid. Diabetic rat gingiva failed to inhibit platelet aggregation but did produce the anti-platelet aggregating activity in the presence of arachidonic acid. Indomethacin blocked the production of anti-platelet aggregating activity. There was no difference in conversion of (1-/sup 14/C)arachidonic acid to prostaglandins by normal and diabetic rat gingiva. These results suggest that an arachidonic acid metabolite released from gingiva during incubation inhibits platelet aggregation, and the synthesis of the metabolite is impaired in diabetic rat gingiva. A decrease in availability of arachidonic acid may be a causal factor of the defect in diabetic rat gingiva.

  9. Gingival tissue-produced inhibition of platelet aggregation and the loss of inhibition in streptozotocin-induced diabetic rats

    International Nuclear Information System (INIS)

    Kawamura, Keiichiroh; Tamai, Kazuharu; Shirakawa, Masaharu; Okamoto, Hiroshi; Dohi, Toshihiro; Tsujimoto, Akira

    1988-01-01

    Addition of medium incubated with normal rat gingival tissue to platelet-rich plasma inhibited ADP-induced platelet aggregation. The ability of rat gingiva to produce activity inhibiting platelet aggregation was enhanced by the addition of arachidonic acid. Diabetic rat gingiva failed to inhibit platelet aggregation but did produce the anti-platelet aggregating activity in the presence of arachidonic acid. Indomethacin blocked the production of anti-platelet aggregating activity. There was no difference in conversion of [1- 14 C]arachidonic acid to prostaglandins by normal and diabetic rat gingiva. These results suggest that an arachidonic acid metabolite released from gingiva during incubation inhibits platelet aggregation, and the synthesis of the metabolite is impaired in diabetic rat gingiva. A decrease in availability of arachidonic acid may be a causal factor of the defect in diabetic rat gingiva. (author)

  10. Molecular Mechanisms of Inhibition of Streptococcus Species by Phytochemicals

    Directory of Open Access Journals (Sweden)

    Soheila Abachi

    2016-02-01

    Full Text Available This review paper summarizes the antibacterial effects of phytochemicals of various medicinal plants against pathogenic and cariogenic streptococcal species. The information suggests that these phytochemicals have potential as alternatives to the classical antibiotics currently used for the treatment of streptococcal infections. The phytochemicals demonstrate direct bactericidal or bacteriostatic effects, such as: (i prevention of bacterial adherence to mucosal surfaces of the pharynx, skin, and teeth surface; (ii inhibition of glycolytic enzymes and pH drop; (iii reduction of biofilm and plaque formation; and (iv cell surface hydrophobicity. Collectively, findings from numerous studies suggest that phytochemicals could be used as drugs for elimination of infections with minimal side effects.

  11. [Mechanisms of retroviral immunosuppressive domain-induced immune modulation].

    Science.gov (United States)

    Blinov, V M; Krasnov, G S; Shargunov, A V; Shurdov, M A; Zverev, V V

    2013-01-01

    Immunosuppressive domains (ISD) of viral envelope glycoproteins provide highly pathogenic phenotypes of various retroviruses. ISD interaction with immune cells leads to an inhibition of a response. In the 1980s it was shown that the fragment of ISD comprising of 17 amino acids (named CKS-17) is carrying out such immune modulation. However the underlying mechanisms were not known. The years of thorough research allowed to identify the regulation of Ras-Raf-MEK-MAPK and PI3K-AKT-mTOR cellular pathways as a result of ISD interaction with immune cells. By the way, this leads to decrease of secretion of stimulatory cytokines (e.g., IL-12) and increase of inhibitory, anti-inflammatory ones (e.g., IL-10). One of the receptor tyrosine kinases inducing signal in these pathways acts as the primary target of ISD while other key regulators--cAMP and diacylglycerol (DAG), act as secondary messengers of signal transduction. Immunosuppressive-like domains can be found not only in retroviruses; the presence of ISD within Ebola viral envelope glycoproteins caused extremely hard clinical course of virus-induced hemorrhagic fever. A number of retroviral-origin fragments encoding ISD can be found in the human genome. These regions are expressed in the placenta within genes of syncytins providing a tolerance of mother's immune system to an embryo. The present review is devoted to molecular aspects of retroviral ISD-induced modulation of host immune system.

  12. Chloride secretion induced by rotavirus is oxidative stress-dependent and inhibited by Saccharomyces boulardii in human enterocytes.

    Directory of Open Access Journals (Sweden)

    Vittoria Buccigrossi

    Full Text Available Rotavirus (RV infection causes watery diarrhea via multiple mechanisms, primarily chloride secretion in intestinal epithelial cell. The chloride secretion largely depends on non-structural protein 4 (NSP4 enterotoxic activity in human enterocytes through mechanisms that have not been defined. Redox imbalance is a common event in cells infected by viruses, but the role of oxidative stress in RV infection is unknown. RV SA11 induced chloride secretion in association with an increase in reactive oxygen species (ROS in Caco-2 cells. The ratio between reduced (GSH and oxidized (GSSG glutathione was decreased by RV. The same effects were observed when purified NSP4 was added to Caco-2 cells. N-acetylcysteine (NAC, a potent antioxidant, strongly inhibited the increase in ROS and GSH imbalance. These results suggest a link between oxidative stress and RV-induced diarrhea. Because Saccharomyces boulardii (Sb has been effectively used to treat RV diarrhea, we tested its effects on RV-infected cells. Sb supernatant prevented RV-induced oxidative stress and strongly inhibited chloride secretion in Caco-2 cells. These results were confirmed in an organ culture model using human intestinal biopsies, demonstrating that chloride secretion induced by RV-NSP4 is oxidative stress-dependent and is inhibited by Sb, which produces soluble metabolites that prevent oxidative stress. The results of this study provide novel insights into RV-induced diarrhea and the efficacy of probiotics.

  13. Chloride secretion induced by rotavirus is oxidative stress-dependent and inhibited by Saccharomyces boulardii in human enterocytes.

    Science.gov (United States)

    Buccigrossi, Vittoria; Laudiero, Gabriella; Russo, Carla; Miele, Erasmo; Sofia, Morena; Monini, Marina; Ruggeri, Franco Maria; Guarino, Alfredo

    2014-01-01

    Rotavirus (RV) infection causes watery diarrhea via multiple mechanisms, primarily chloride secretion in intestinal epithelial cell. The chloride secretion largely depends on non-structural protein 4 (NSP4) enterotoxic activity in human enterocytes through mechanisms that have not been defined. Redox imbalance is a common event in cells infected by viruses, but the role of oxidative stress in RV infection is unknown. RV SA11 induced chloride secretion in association with an increase in reactive oxygen species (ROS) in Caco-2 cells. The ratio between reduced (GSH) and oxidized (GSSG) glutathione was decreased by RV. The same effects were observed when purified NSP4 was added to Caco-2 cells. N-acetylcysteine (NAC), a potent antioxidant, strongly inhibited the increase in ROS and GSH imbalance. These results suggest a link between oxidative stress and RV-induced diarrhea. Because Saccharomyces boulardii (Sb) has been effectively used to treat RV diarrhea, we tested its effects on RV-infected cells. Sb supernatant prevented RV-induced oxidative stress and strongly inhibited chloride secretion in Caco-2 cells. These results were confirmed in an organ culture model using human intestinal biopsies, demonstrating that chloride secretion induced by RV-NSP4 is oxidative stress-dependent and is inhibited by Sb, which produces soluble metabolites that prevent oxidative stress. The results of this study provide novel insights into RV-induced diarrhea and the efficacy of probiotics.

  14. The alpha2-adrenoreceptor agonist dexmedetomidine protects against lipopolysaccharide-induced apoptosis via inhibition of gap junctions in lung fibroblasts.

    Science.gov (United States)

    Zhang, Yuan; Tan, Xiaoming; Xue, Lianfang

    2018-01-01

    The α2-adrenoceptor inducer dexmedetomidine protects against acute lung injury (ALI), but the mechanism of this effect is largely unknown. The present study investigated the effect of dexmedetomidine on apoptosis induced by lipopolysaccharide (LPS) and the relationship between this effect and gap junction intercellular communication in human lung fibroblast cell line. Flow cytometry was used to detect apoptosis induced by LPS. Parachute dye coupling assay was used to measure gap junction function, and western blot analysis was used to determine the expression levels of connexin43 (Cx43). The results revealed that exposure of human lung fibroblast cell line to LPS for 24 h increased the apoptosis, and pretreatment of dexmedetomidine and 18α-GA significantly reduced LPS-induced apoptosis. Dexmedetomidine exposure for 1 h inhibited gap junction function mainly via a decrease in Cx43 protein levels in human lung fibroblast cell line. These results demonstrated that the inhibition of gap junction intercellular communication by dexmedetomidine affected the LPS-induced apoptosis through inhibition of gap junction function by reducing Cx43 protein levels. The present study provides evidence of a novel mechanism underlying the effects of analgesics in counteracting ALI. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. GSK621 activates AMPK signaling to inhibit LPS-induced TNFα production

    International Nuclear Information System (INIS)

    Wu, Yong-hong; Li, Quan; Li, Ping; Liu, Bei

    2016-01-01

    LPS stimulation in macrophages/monocytes induces TNFα production. We here tested the potential effect of GSK621, a novel AMP-activated protein kinase (AMPK) activator, against the process. In RAW264.7 macrophages, murine bone marrow-derived macrophages (BMDMs), and chronic obstructive pulmonary disease (COPD) patients' monocytes, GSK621 significantly inhibited LPS-induced TNFα protein secretion and mRNA synthesis. Inhibition of AMPK, through AMPKα shRNA knockdown or dominant negative mutation (T172A), almost abolished GSK621's suppression on TNFα in RAW264.7 cells. Reversely, forced-expression of a constitutively-active AMPKα (T172D) mimicked GSK621 actions and reduced LPS-induced TNFα production. Molecularly, GSK621 suppressed LPS-induced reactive oxygen species (ROS) production and nuclear factor kappa B (NFκB) activation. In vivo, GSK621 oral administration inhibited LPS-induced TNFα production and endotoxin shock in mice. In summary, GSK621 activates AMPK signaling to inhibit LPS-induced TNFα production in macrophages/monocytes. - Highlights: • GSK621 inhibits LPS-induced TNFα production/expression in RAW264.7 cells and BMDMs. • GSK621 inhibits LPS-induced TNFα production/expression in COPD patients' PBMCs. • GSK621's inhibition on TNFα production by LPS requires AMPK activation. • GSK621 inhibits LPS-induced ROS production and NFκB activation, dependent on AMPK. • GSK621 oral administration inhibits LPS-induced TNFα production and endotoxin shock in mice.

  16. Optogenetic inhibition of chemically induced hypersynchronized bursting in mice

    DEFF Research Database (Denmark)

    Berglind, Fredrik; Ledri, Marco; Sørensen, Andreas Toft

    2014-01-01

    hyperpolarization and thereby inactivation of a principal neuronal population in the hippocampus is effectively attenuating seizure activity caused by disconnected network inhibition both in vitro and in vivo. Our data suggest that epileptiform activity in the hippocampus caused by impaired inhibition may...

  17. Myelin-induced inhibition in a spiral ganglion organ culture - Approaching a natural environment in vitro.

    Science.gov (United States)

    Kramer, Benedikt; Tropitzsch, Anke; Müller, Marcus; Löwenheim, Hubert

    2017-08-15

    The performance of a cochlear implant depends on the defined interaction between afferent neurons of the spiral ganglion and the inserted electrode. Neurite outgrowth can be induced by neurotrophins such as brain-derived neurotrophic factor (BDNF) via tropomyosin kinase receptor B (TrkB). However, neurotrophin signaling through the p75 neurotrophin receptor (p75) inhibits neurite outgrowth in the presence of myelin. Organotypic cultures derived from postnatal (P3-5) mice were used to study myelin-induced inhibition in the cochlear spiral ganglion. Neurite outgrowth was analyzed and quantified utilizing an adapted Sholl analysis. Stimulation of neurite outgrowth was quantified after application of BDNF, the selective TrkB agonist 7,8-dihydroxyflavone (7,8-DHF) and a selective inhibitor of the Rho-associated kinase (Y27632), which inhibits the p75 pathway. Myelin-induced inhibition was assessed by application of myelin-associated glycoprotein (MAG-Fc) to stimulate the inhibitory p75 pathway. Inhibition of neurite outgrowth was achieved by the selective TrkB inhibitor K252a. Stimulation of neurite outgrowth was observed after treatment with BDNF, 7,8 DHF and a combination of BDNF and Y27632. The 7,8-DHF-induced growth effects could be inhibited by K252a. Furthermore, inhibition of neurite outgrowth was observed after supplementation with MAG-Fc. Myelin-induced inhibition could be overcome by 7,8-DHF and the combination of BDNF and Y27632. In this study, myelin-induced inhibition of neurite outgrowth was established in a spiral ganglion model. We reveal that 7,8-DHF is a viable novel compound for the stimulation of neurite outgrowth in a myelin-induced inhibitory environment. The combination of TrkB stimulation and ROCK inhibition can be used to overcome myelin inhibition. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  18. Mechanism of inhibition of growth hormone receptor signaling by suppressor of cytokine signaling proteins

    DEFF Research Database (Denmark)

    Hansen, J A; Lindberg, K; Hilton, D J

    1999-01-01

    In this study we have investigated the role of suppressor of cytokine signaling (SOCS) proteins in GH receptor-mediated signaling. GH-induced transcription was inhibited by SOCS-1 and SOCS-3, while SOCS-2 and cytokine inducible SH2-containing protein (CIS) had no effect By using chimeric SOCS pro...

  19. Mechanism of ultraviolet light induced catabolite repression of L-arabinose isomerase

    Energy Technology Data Exchange (ETDEWEB)

    Bhatnagar, D; Bhattacharya, A K [Banaras Hindu Univ. (India). Inst. of Medical Sciences

    1982-12-01

    An attempt has been made to find out how U.V. irradiation of E.coli B/r cells causes catabolite repression to inhibit L-arabinose isomerase synthesis. The results presented show that U.V. irradiation leads to a lowering of the cellular cyclic AMP level and of the cyclic AMP binding activity. Unlike catabolite repression by glucose, no small molecular weight compound is involved in U.V. light induced inhibition of the binding activity. It is therefore concluded that the mechanism of catabolite repression induced by U.V. appears to be different from that of the catabolite repression by glucose.

  20. Inhibition of matrix metalloproteinase-9 activity by doxycycline ameliorates RANK ligand-induced osteoclast differentiation in vitro and in vivo

    International Nuclear Information System (INIS)

    Franco, Gilson C.N.; Kajiya, Mikihito; Nakanishi, Tadashi; Ohta, Kouji; Rosalen, Pedro L.; Groppo, Francisco C.; Ernst, Cory W.O.; Boyesen, Janie L.; Bartlett, John D.; Stashenko, Philip; Taubman, Martin A.; Kawai, Toshihisa

    2011-01-01

    Tetracycline antibiotics, including doxycycli/e (DOX), have been used to treat bone resorptive diseases, partially because of their activity to suppress osteoclastogenesis induced by receptor activator of nuclear factor kappa B ligand (RANKL). However, their precise inhibitory mechanism remains unclear. Therefore, the present study examined the effect of Dox on osteoclastogenesis signaling induced by RANKL, both in vitro and in vivo. Although Dox inhibited RANKL-induced osteoclastogenesis and down-modulated the mRNA expression of functional osteoclast markers, including tartrate-resistant acid phosphatase (TRAP) and cathepsin K, Dox neither affected RANKL-induced MAPKs phosphorylation nor NFATc1 gene expression in RAW264.7 murine monocytic cells. Gelatin zymography and Western blot analyses showed that Dox down-regulated the enzyme activity of RANKL-induced MMP-9, but without affecting its protein expression. Furthermore, MMP-9 enzyme inhibitor also attenuated both RANKL-induced osteoclastogenesis and up-regulation of TRAP and cathepsin K mRNA expression, indicating that MMP-9 enzyme action is engaged in the promotion of RANKL-induced osteoclastogenesis. Finally, Dox treatment abrogated RANKL-induced osteoclastogenesis and TRAP activity in mouse calvaria along with the suppression of MMP9 enzyme activity, again without affecting the expression of MMP9 protein. These findings suggested that Dox inhibits RANKL-induced osteoclastogenesis by its inhibitory effect on MMP-9 enzyme activity independent of the MAPK-NFATc1 signaling cascade.

  1. Inhibition of matrix metalloproteinase-9 activity by doxycycline ameliorates RANK ligand-induced osteoclast differentiation in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Gilson C.N. [Department of Immunology, Forsyth Institute, Cambridge, MA (United States); Department of Pharmacology, FOP/UNICAMP, Piracicaba, SP (Brazil); Kajiya, Mikihito [Department of Immunology, Forsyth Institute, Cambridge, MA (United States); Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA (United States); Nakanishi, Tadashi [Department of Immunology, Forsyth Institute, Cambridge, MA (United States); Ohta, Kouji [Department of Immunology, Forsyth Institute, Cambridge, MA (United States); Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA (United States); Rosalen, Pedro L.; Groppo, Francisco C. [Department of Pharmacology, FOP/UNICAMP, Piracicaba, SP (Brazil); Ernst, Cory W.O.; Boyesen, Janie L. [Department of Immunology, Forsyth Institute, Cambridge, MA (United States); Bartlett, John D.; Stashenko, Philip [Department of Cytokine Biology, Forsyth Institute, Cambridge, MA (United States); Taubman, Martin A. [Department of Immunology, Forsyth Institute, Cambridge, MA (United States); Kawai, Toshihisa, E-mail: tkawai@forsyth.org [Department of Immunology, Forsyth Institute, Cambridge, MA (United States); Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA (United States)

    2011-06-10

    Tetracycline antibiotics, including doxycycli/e (DOX), have been used to treat bone resorptive diseases, partially because of their activity to suppress osteoclastogenesis induced by receptor activator of nuclear factor kappa B ligand (RANKL). However, their precise inhibitory mechanism remains unclear. Therefore, the present study examined the effect of Dox on osteoclastogenesis signaling induced by RANKL, both in vitro and in vivo. Although Dox inhibited RANKL-induced osteoclastogenesis and down-modulated the mRNA expression of functional osteoclast markers, including tartrate-resistant acid phosphatase (TRAP) and cathepsin K, Dox neither affected RANKL-induced MAPKs phosphorylation nor NFATc1 gene expression in RAW264.7 murine monocytic cells. Gelatin zymography and Western blot analyses showed that Dox down-regulated the enzyme activity of RANKL-induced MMP-9, but without affecting its protein expression. Furthermore, MMP-9 enzyme inhibitor also attenuated both RANKL-induced osteoclastogenesis and up-regulation of TRAP and cathepsin K mRNA expression, indicating that MMP-9 enzyme action is engaged in the promotion of RANKL-induced osteoclastogenesis. Finally, Dox treatment abrogated RANKL-induced osteoclastogenesis and TRAP activity in mouse calvaria along with the suppression of MMP9 enzyme activity, again without affecting the expression of MMP9 protein. These findings suggested that Dox inhibits RANKL-induced osteoclastogenesis by its inhibitory effect on MMP-9 enzyme activity independent of the MAPK-NFATc1 signaling cascade.

  2. Inhibition of cAMP-activated intestinal chloride secretion by diclofenac: cellular mechanism and potential application in cholera.

    Science.gov (United States)

    Pongkorpsakol, Pawin; Pathomthongtaweechai, Nutthapoom; Srimanote, Potjanee; Soodvilai, Sunhapas; Chatsudthipong, Varanuj; Muanprasat, Chatchai

    2014-09-01

    Cyclic AMP-activated intestinal Cl- secretion plays an important role in pathogenesis of cholera. This study aimed to investigate the effect of diclofenac on cAMP-activated Cl- secretion, its underlying mechanisms, and possible application in the treatment of cholera. Diclofenac inhibited cAMP-activated Cl- secretion in human intestinal epithelial (T84) cells with IC50 of ∼ 20 µM. The effect required no cytochrome P450 enzyme-mediated metabolic activation. Interestingly, exposures of T84 cell monolayers to diclofenac, either in apical or basolateral solutions, produced similar degree of inhibitions. Analyses of the apical Cl- current showed that diclofenac reversibly inhibited CFTR Cl- channel activity (IC50 ∼ 10 µM) via mechanisms not involving either changes in intracellular cAMP levels or CFTR channel inactivation by AMP-activated protein kinase and protein phosphatase. Of interest, diclofenac had no effect on Na(+)-K(+) ATPases and Na(+)-K(+)-Cl- cotransporters, but inhibited cAMP-activated basolateral K(+) channels with IC50 of ∼ 3 µM. In addition, diclofenac suppressed Ca(2+)-activated Cl- channels, inwardly rectifying Cl- channels, and Ca(2+)-activated basolateral K(+) channels. Furthermore, diclofenac (up to 200 µM; 24 h of treatment) had no effect on cell viability and barrier function in T84 cells. Importantly, cholera toxin (CT)-induced Cl- secretion across T84 cell monolayers was effectively suppressed by diclofenac. Intraperitoneal administration of diclofenac (30 mg/kg) reduced both CT and Vibrio cholerae-induced intestinal fluid secretion by ∼ 70% without affecting intestinal fluid absorption in mice. Collectively, our results indicate that diclofenac inhibits both cAMP-activated and Ca(2+)-activated Cl- secretion by inhibiting both apical Cl- channels and basolateral K+ channels in intestinal epithelial cells. Diclofenac may be useful in the treatment of cholera and other types of secretory diarrheas resulting from intestinal

  3. Inhibition of cAMP-activated intestinal chloride secretion by diclofenac: cellular mechanism and potential application in cholera.

    Directory of Open Access Journals (Sweden)

    Pawin Pongkorpsakol

    2014-09-01

    Full Text Available Cyclic AMP-activated intestinal Cl- secretion plays an important role in pathogenesis of cholera. This study aimed to investigate the effect of diclofenac on cAMP-activated Cl- secretion, its underlying mechanisms, and possible application in the treatment of cholera. Diclofenac inhibited cAMP-activated Cl- secretion in human intestinal epithelial (T84 cells with IC50 of ∼ 20 µM. The effect required no cytochrome P450 enzyme-mediated metabolic activation. Interestingly, exposures of T84 cell monolayers to diclofenac, either in apical or basolateral solutions, produced similar degree of inhibitions. Analyses of the apical Cl- current showed that diclofenac reversibly inhibited CFTR Cl- channel activity (IC50 ∼ 10 µM via mechanisms not involving either changes in intracellular cAMP levels or CFTR channel inactivation by AMP-activated protein kinase and protein phosphatase. Of interest, diclofenac had no effect on Na(+-K(+ ATPases and Na(+-K(+-Cl- cotransporters, but inhibited cAMP-activated basolateral K(+ channels with IC50 of ∼ 3 µM. In addition, diclofenac suppressed Ca(2+-activated Cl- channels, inwardly rectifying Cl- channels, and Ca(2+-activated basolateral K(+ channels. Furthermore, diclofenac (up to 200 µM; 24 h of treatment had no effect on cell viability and barrier function in T84 cells. Importantly, cholera toxin (CT-induced Cl- secretion across T84 cell monolayers was effectively suppressed by diclofenac. Intraperitoneal administration of diclofenac (30 mg/kg reduced both CT and Vibrio cholerae-induced intestinal fluid secretion by ∼ 70% without affecting intestinal fluid absorption in mice. Collectively, our results indicate that diclofenac inhibits both cAMP-activated and Ca(2+-activated Cl- secretion by inhibiting both apical Cl- channels and basolateral K+ channels in intestinal epithelial cells. Diclofenac may be useful in the treatment of cholera and other types of secretory diarrheas resulting from intestinal

  4. Tob1 induces apoptosis and inhibits proliferation, migration and invasion of gastric cancer cells by activating Smad4 and inhibiting β‑catenin signaling.

    Science.gov (United States)

    Kundu, Juthika; Wahab, S M Riajul; Kundu, Joydeb Kumar; Choi, Yoon-La; Erkin, Ozgur Cem; Lee, Hun Seok; Park, Sang Gyu; Shin, Young Kee

    2012-09-01

    Transducer of ErbB-2.1 (Tob1), a tumor suppressor protein, is inactivated in a variety of cancers including stomach cancer. However, the role of Tob1 in gastric carcinogenesis remains elusive. The present study aimed to investigate whether Tob1 could inhibit gastric cancer progression in vitro, and to elucidate its underlying molecular mechanisms. We found differential expression of Tob1 in human gastric cancer (MKN28, AGS and MKN1) cells. The overexpression of Tob1 induced apoptosis in MKN28 and AGS cells, which was associated with sub-G1 arrest, activation of caspase-3, induction of Bax, inhibition of Bcl-2 and cleavage of poly (ADP-ribose) polymerase (PARP). In addition, Tob1 inhibited proliferation, migration and invasion, which were reversed in MKN1 and AGS cells transfected with Tob1 siRNA. Overexpression of Tob1 in MKN28 and AGS cells induced the expression of Smad4, leading to the increased expression and the promoter activity of p15, which was diminished by silencing of Tob1 using specific siRNA. Tob1 decreased the phosphorylation of Akt and glycogen synthase kinase-3β (GSK3β) in MKN28 and AGS cells, resulting in the reduced protein expression and the transcriptional activity of β‑catenin, which in turn decreased the expression of cyclin D1, cyclin-dependent kinase-4 (CDK4), urokinase plasminogen activator receptor (uPAR) and peroxisome proliferator and activator receptor-δ (PPARδ). Conversely, silencing of Tob1 induced the phosphorylation of Akt and GSK-3β, and increased the expression of β‑catenin and its target genes. Collectively, our study demonstrates that the overexpression of Tob1 inhibits gastric cancer progression by activating Smad4- and inhibiting β‑catenin-mediated signaling pathways.

  5. Medullary Reticular Neurons Mediate Neuropeptide Y-Induced Metabolic Inhibition and Mastication.

    Science.gov (United States)

    Nakamura, Yoshiko; Yanagawa, Yuchio; Morrison, Shaun F; Nakamura, Kazuhiro

    2017-02-07

    Hypothalamic neuropeptide Y (NPY) elicits hunger responses to increase the chances of surviving starvation: an inhibition of metabolism and an increase in feeding. Here we elucidate a key central circuit mechanism through which hypothalamic NPY signals drive these hunger responses. GABAergic neurons in the intermediate and parvicellular reticular nuclei (IRt/PCRt) of the medulla oblongata, which are activated by NPY-triggered neural signaling from the hypothalamus, potentially through the nucleus tractus solitarius, mediate the NPY-induced inhibition of metabolic thermogenesis in brown adipose tissue (BAT) via their innervation of BAT sympathetic premotor neurons. Intriguingly, the GABAergic IRt/PCRt neurons innervating the BAT sympathetic premotor region also innervate the masticatory motor region, and stimulation of the IRt/PCRt elicits mastication and increases feeding as well as inhibits BAT thermogenesis. These results indicate that GABAergic IRt/PCRt neurons mediate hypothalamus-derived hunger signaling by coordinating both autonomic and feeding motor systems to reduce energy expenditure and to promote feeding. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Inhibition of p38 MAPK enhances ABT-737-induced cell death in melanoma cell lines: novel regulation of PUMA.

    Science.gov (United States)

    Keuling, Angela M; Andrew, Susan E; Tron, Victor A

    2010-06-01

    The mitogen-activated protein kinase (MAPK) pathway is constitutively activated in the majority of melanomas, promoting cell survival, proliferation and migration. In addition, anti-apoptotic Bcl-2 family proteins Mcl-1, Bcl-xL and Bcl-2 are frequently overexpressed, contributing to melanoma's well-documented chemoresistance. Recently, it was reported that the combination of MAPK pathway inhibition by specific MEK inhibitors and Bcl-2 family inhibition by BH3-mimetic ABT-737 synergistically induces apoptotic cell death in melanoma cell lines. Here we provide the first evidence that inhibition of another key MAPK, p38, synergistically induces apoptosis in melanoma cells in combination with ABT-737. We also provide novel mechanistic data demonstrating that inhibition of p38 increases expression of pro-apoptotic Bcl-2 protein PUMA. Furthermore, we demonstrate that PUMA can be cleaved by a caspase-dependent mechanism during apoptosis and identify what appears to be the PUMA cleavage product. Thus, our findings suggest that the combination of ABT-737 and inhibition of p38 is a promising, new treatment strategy that acts through a novel PUMA-dependent mechanism.

  7. Estrogen alleviates neuropathic pain induced after spinal cord injury by inhibiting microglia and astrocyte activation.

    Science.gov (United States)

    Lee, Jee Youn; Choi, Hae Young; Ju, Bong-Gun; Yune, Tae Young

    2018-04-16

    Neuropathic pain after spinal cord injury (SCI) is developed in about 80% of SCI patients and there is no efficient therapeutic drug to alleviate SCI-induced neuropathic pain. Here we examined the effect of estrogen on SCI-induced neuropathic pain at below-level and its effect on neuroinflammation as underlying mechanisms. Neuropathic pain is developed at late phase after SCI and a single dose of 17β-estradiol (100, 300 μg/kg) were administered to rats with neuropathic pain after SCI through intravenous injection. As results, both mechanical allodynia and thermal hyperalgesia were significantly reduced by 17β-estradiol compared to vehicle control. Both microglia and astrocyte activation in the lamina I and II of L4-5 dorsal horn was also inhibited by 17β-estradiol. In addition, the levels of p-p38MAPK and p-ERK known to be activated in microglia and p-JNK known to be activated in astrocyte were significantly decreased by 17β-estradiol. Furthermore, the mRNA expression of inflammatory mediators such as Il-1β, Il-6, iNos, and Cox-2 was more attenuated in 17β-estradiol-treated group than in vehicle-treated group. Particularly, we found that the analgesic effect by 17β-estradiol was mediated via estrogen receptors, which are expressed in dorsal horn neurons. These results suggest that 17β-estradiol may attenuate SCI-induced neuropathic pain by inhibiting microglia and astrocyte activation followed inflammation. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Mechanical unloading reduces microtubule actin crosslinking factor 1 expression to inhibit β-catenin signaling and osteoblast proliferation.

    Science.gov (United States)

    Yin, Chong; Zhang, Yan; Hu, Lifang; Tian, Ye; Chen, Zhihao; Li, Dijie; Zhao, Fan; Su, Peihong; Ma, Xiaoli; Zhang, Ge; Miao, Zhiping; Wang, Liping; Qian, Airong; Xian, Cory J

    2018-07-01

    Mechanical unloading was considered a major threat to bone homeostasis, and has been shown to decrease osteoblast proliferation although the underlying mechanism is unclear. Microtubule actin crosslinking factor 1 (MACF1) is a cytoskeletal protein that regulates cellular processes and Wnt/β-catenin pathway, an essential signaling pathway for osteoblasts. However, the relationship between MACF1 expression and mechanical unloading, and the function and the associated mechanisms of MACF1 in regulating osteoblast proliferation are unclear. This study investigated effects of mechanical unloading on MACF1 expression levels in cultured MC3T3-E1 osteoblastic cells and in femurs of mice with hind limb unloading; and it also examined the role and potential action mechanisms of MACF1 in osteoblast proliferation in MACF1-knockdown, overexpressed or control MC3T3-E1 cells treated with or without the mechanical unloading condition. Results showed that the mechanical unloading condition inhibited osteoblast proliferation and MACF1 expression in MC3T3-E1 osteoblastic cells and mouse femurs. MACF1 knockdown decreased osteoblast proliferation, while MACF1 overexpression increased it. The inhibitory effect of mechanical unloading on osteoblast proliferation also changed with MACF1 expression levels. Furthermore, MACF1 was found to enhance β-catenin expression and activity, and mechanical unloading decreased β-catenin expression through MACF1. Moreover, β-catenin was found an important regulator of osteoblast proliferation, as its preservation by treatment with its agonist lithium attenuated the inhibitory effects of MACF1-knockdown or mechanical unloading on osteoblast proliferation. Taken together, mechanical unloading decreases MACF1 expression, and MACF1 up-regulates osteoblast proliferation through enhancing β-catenin signaling. This study has thus provided a mechanism for mechanical unloading-induced inhibited osteoblast proliferation. © 2017 Wiley Periodicals, Inc.

  9. Triptolide inhibits TGF-β1-induced cell proliferation in rat airway smooth muscle cells by suppressing Smad signaling

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ming; Lv, Zhiqiang; Huang, Linjie [Department of Respiratory Medicine, Sun Yat-Sen Memorial Hospital, Institute for Respiratory disease of Sun Yat-sen University, Sun Yat-sen University, Guangzhou, Guangdong Province 510120 (China); Zhang, Wei [Department of Geratology, the Second People' s Hospital of Shenzhen, Shenzhen 518000 (China); Lin, Xiaoling; Shi, Jianting; Zhang, Wei; Liang, Ruiyun [Department of Respiratory Medicine, Sun Yat-Sen Memorial Hospital, Institute for Respiratory disease of Sun Yat-sen University, Sun Yat-sen University, Guangzhou, Guangdong Province 510120 (China); Jiang, Shanping, E-mail: shanpingjiang@126.com [Department of Respiratory Medicine, Sun Yat-Sen Memorial Hospital, Institute for Respiratory disease of Sun Yat-sen University, Sun Yat-sen University, Guangzhou, Guangdong Province 510120 (China)

    2015-02-15

    Background: We have reported that triptolide can inhibit airway remodeling in a murine model of asthma via TGF-β1/Smad signaling. In the present study, we aimed to investigate the effect of triptolide on airway smooth muscle cells (ASMCs) proliferation and the possible mechanism. Methods: Rat airway smooth muscle cells were cultured and made synchronized, then pretreated with different concentration of triptolide before stimulated by TGF-β1. Cell proliferation was evaluated by MTT assay. Flow cytometry was used to study the influence of triptolide on cell cycle and apoptosis. Signal proteins (Smad2, Smad3 and Smad7) were detected by western blotting analysis. Results: Triptolide significantly inhibited TGF-β1-induced ASMC proliferation (P<0.05). The cell cycle was blocked at G1/S-interphase by triptolide dose dependently. No pro-apoptotic effects were detected under the concentration of triptolide we used. Western blotting analysis showed TGF-β1 induced Smad2 and Smad3 phosphorylation was inhibited by triptolide pretreatment, and the level of Smad7 was increased by triptolide pretreatment. Conclusions: Triptolide may function as an inhibitor of asthma airway remodeling by suppressing ASMCs proliferation via negative regulation of Smad signaling pathway. - Highlights: • In this study, rat airway smooth muscle cells were cultured and made synchronized. • Triptolide inhibited TGF-β1-induced airway smooth muscle cells proliferation. • Triptolide inhibited ASMCs proliferation via negative regulation of Smad signaling pathway.

  10. Mechanisms of shock-induced dynamic friction

    International Nuclear Information System (INIS)

    Winter, R E; Ball, G J; Keightley, P T

    2006-01-01

    The mechanism of shock-induced dynamic friction has been explored through an integrated programme of experiments and numerical simulations. A novel experimental technique has been developed for observing the sub-surface deformation in aluminium when sliding against a steel anvil at high velocity and pressure. The experimental observations suggest that slight differences in conditions at the interface between the metals affect frictional behaviour even at the very high-velocity, high-pressure regime studied here. However, a clear finding from the experimental work is the presence of two distinct modes of deformation termed deep and shallow. The deep deformation is observed in a region of the aluminium specimen where the interfacial velocity is relatively low and the shallow deformation is observed in a region where the interfacial velocity is higher. A 1D numerical treatment is presented which predicts the existence of two mechanisms for dynamic friction termed 'asymptotic melting' and 'slide-then-lock'. In both modes there is a warm-up phase in which the interface temperature is increased by frictional heating. For high initial sliding velocity, this is followed by the onset of the asymptotic melting state, in which the temperature is almost constant and melting is approached asymptotically. This mechanism produces low late-time frictional stress and shallow deformation. For lower initial sliding velocity, the warm-up terminates in a violent work hardening event that locks the interface and launches a strong plastic shear wave into the weaker material. This slide-then-lock mechanism is characterized by sustained high frictional stress and deep plastic deformation. These predicted mechanisms offer a plausible and consistent explanation for the abrupt transitions in the depth of sub-surface deformation observed in the experiments. A key conclusion arising from the current work is that the frictional stress does not vary smoothly with pressure or sliding velocity

  11. Kaempferol suppresses bladder cancer tumor growth by inhibiting cell proliferation and inducing apoptosis.

    Science.gov (United States)

    Dang, Qiang; Song, Wenbin; Xu, Defeng; Ma, Yanmin; Li, Feng; Zeng, Jin; Zhu, Guodong; Wang, Xinyang; Chang, Luke S; He, Dalin; Li, Lei

    2015-09-01

    The effects of the flavonoid compound, kaempferol, which is an inhibitor of cancer cell proliferation and an inducer of cell apoptosis have been shown in various cancers, including lung, pancreatic, and ovarian, but its effect has never been studied in bladder cancer. Here, we investigated the effects of kaempferol on bladder cancer using multiple in vitro cell lines and in vivo mice studies. The MTT assay results on various bladder cancer cell lines showed that kaempferol enhanced bladder cancer cell cytotoxicity. In contrast, when analyzed by the flow cytometric analysis, DNA ladder experiment, and TUNEL assay, kaempferol significantly was shown to induce apoptosis and cell cycle arrest. These in vitro results were confirmed in in vivo mice studies using subcutaneous xenografted mouse models. Consistent with the in vitro results, we found that treating mice with kaempferol significant suppression in tumor growth compared to the control group mice. Tumor tissue staining results showed decreased expressions of the growth related markers, yet increased expressions in apoptosis markers in the kaempferol treated group mice tissues compared to the control group mice. In addition, our in vitro and in vivo data showed kaempferol can also inhibit bladder cancer invasion and metastasis. Further mechanism dissection studies showed that significant down-regulation of the c-Met/p38 signaling pathway is responsible for the kaempferol mediated cell proliferation inhibition. All these findings suggest kaempferol might be an effective and novel chemotherapeutic drug to apply for the future therapeutic agent to combat bladder cancer. © 2014 Wiley Periodicals, Inc.

  12. Solena amplexicaulis induces cell cycle arrest, apoptosis and inhibits angiogenesis in hepatocarcinoma cells and HUVECs.

    Science.gov (United States)

    Ren, Jie; Xu, Yuan Yuan; Jiang, He Fei; Yang, Meng; Huang, Qian Hui; Yang, Jie; Hu, Kun; Wei, Kun

    2014-01-01

    Solena amplexicaulis (Lam.) Gandhi (SA) has been used as a traditional medicine for the treatment of dysentery, multiple abscess, gastralgia, urethritis, and eczema in the minority area of China. This study was aimed to examine the cell proliferation inhibitory activity of the SA extract (SACE) and its mechanism of action in human hepatoma cell line (HepG2) and evaluate its anti-angiogenesis activity in human umbilical vein endothelial cell line (HUVEC). SACE could inhibit the growth of HepG2 cells in a dose- and time-dependent manner. FCM analysis showed that SACE could induce G2/M phase arrest, cell apoptosis, the mitochondrial membrane potential loss (ΔΨm) and increase the production of intracellular ROS of HepG2 cells. After treatment with SACE, topical morphological changes of apoptotic body formation, obvious increase of apoptosis-related protein expressions, such as Bax, cytochrome c, caspase-3, PARP-1, and decrease of Bcl-2, procaspase-9 protein expressions were observed at the same time. Moreover, SACE caused the significant inhibition of endothelial cell migration and tube formation in HUVEC cells. The results suggested that SACE could act as an angiogenesis inhibitor and induce cell apoptosis via a caspase-dependent mitochondrial pathway. Therefore, SACE could be a potent candidate for the prevention and treatment of liver cancer.

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

    Science.gov (United States)

    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.

  14. Lactobacillus salivarius REN inhibits rat oral cancer induced by 4-nitroquioline 1-oxide.

    Science.gov (United States)

    Zhang, Ming; Wang, Fang; Jiang, Lu; Liu, Ruihai; Zhang, Lian; Lei, Xingen; Li, Jiyou; Jiang, Jingli; Guo, Huiyuan; Fang, Bing; Zhao, Liang; Ren, Fazheng

    2013-07-01

    Despite significant advances in cancer therapy, cancer-related mobility and mortality are still rising. Alternative strategies such as cancer prevention thus become essential. Probiotics represent an emerging option for cancer prevention, but studies are limited to colon cancers. The efficiency of probiotics in the prevention of other cancers and the correlative mechanism remains to be explored. A novel probiotics Lactobacillus salivarius REN (L. salivarius REN) was isolated from centenarians at Bama of China, which showed highly potent antigenotoxicity in an initial assay. 4-nitroquioline 1-oxide (4NQO)-induced oral cancer model was introduced to study the anticancer activity of L. salivarius REN in vivo. The results indicated that oral administration of probiotic L. salivarius REN or its secretions could effectively suppress 4NQO-induced oral carcinogenesis in the initial and postinitial stage, and the inhibition was in a dose-dependent manner. A significant decrease of neoplasm incidence (65%-0%) was detected in rats fed with the high dose of L. salivarius REN [5 × 10(10) CFU/kg body weight (bw)/d]. In vivo evidences indicated that the probiotics inhibited 4NQO-induced oral cancer by protecting DNA against oxidative damage and downregulating COX-2 expression. L. salivarius REN treatment significantly decreased the expression of proliferating cell nuclear antigen (PCNA) and induced apoptosis in a dose-dependent manner. Our findings suggest that probiotics may act as potential agents for oral cancer prevention. This is the first report showing the inhibitory effect of the probiotics on oral carcinogenesis. ©2013 AACR.

  15. Transforming growth factor β1 inhibition protects from noise-induced hearing loss

    Directory of Open Access Journals (Sweden)

    Silvia eMurillo-Cuesta

    2015-03-01

    Full Text Available Excessive exposure to noise damages the principal cochlear structures leading to hearing impairment. Inflammatory and immune responses are central mechanisms in cochlear defensive response to noise but, if unregulated, they contribute to inner ear damage and hearing loss. Transforming growth factor ß (TGF-ß is a key regulator of both responses and high levels of this factor have been associated with cochlear injury in hearing loss animal models. To evaluate the potential of targeting TGF-ß as a therapeutic strategy for preventing or ameliorating noise-induced hearing loss, we studied the auditory function, cochlear morphology, gene expression and oxidative stress markers in mice exposed to noise and treated with TGF-ß1 peptidic inhibitors P17 and P144, just before or immediately after noise insult. Our results indicate that systemic administration of both peptides significantly improved both the evolution of hearing thresholds and the degenerative changes induced by noise-exposure in lateral wall structures. Moreover, treatments ameliorated the inflammatory state and redox balance. These therapeutic effects were dose-dependent and more effective if the TGF-ß1 inhibitors were administered prior to inducing the injury. In conclusion, inhibition of TGF-ß1 actions with antagonistic peptides represents a new, promising therapeutic strategy for the prevention and repair of noise-induced cochlear damage.

  16. Phenylarsine Oxide Inhibits the Fusicoccin-Induced Activation of Plasma Membrane H+-ATPase1

    Science.gov (United States)

    Olivari, Claudio; Albumi, Cristina; Pugliarello, Maria Chiara; De Michelis, Maria Ida

    2000-01-01

    To investigate the mechanism by which fusicoccin (FC) induces the activation of the plasma membrane (PM) H+-ATPase, we used phenylarsine oxide (PAO), a known inhibitor of protein tyrosine-phosphatases. PAO was supplied in vivo in the absence or presence of FC to radish (Raphanus sativus L.) seedlings and cultured Arabidopsis cells prior to PM extraction. Treatment with PAO alone caused a slight decrease of PM H+-ATPase activity and, in radish, a decrease of PM-associated 14-3-3 proteins. When supplied prior to FC, PAO drastically inhibited FC-induced activation of PM H+-ATPase, FC binding to the PM, and the FC-induced increase of the amount of 14-3-3 associated with the PM. On the contrary, PAO was completely ineffective on all of the above-mentioned parameters when supplied after FC. The H+-ATPase isolated from PAO-treated Arabidopsis cells maintained the ability to respond to FC if supplied with exogenous, nonphosphorylated 14-3-3 proteins. Altogether, these results are consistent with a model in which the dephosphorylated state of tyrosine residues of a protein(s), such as 14-3-3 protein, is required to permit FC-induced association between the 14-3-3 protein and the PM H+-ATPase. PMID:10677439

  17. Mechanisms of inhibition of DNA replication by ultraviolet light in normal human and xeroderma pigmentosum fibroblasts

    International Nuclear Information System (INIS)

    Kaufmann, W.K.; Cleaver, J.E.

    1981-01-01

    The inhibition of DNA replication in ultraviolet-irradiated human fibroblasts was characterized by quantitative analysis of radiation-induced alterations in the steady-state distribution of sizes of pulse-labeled, nascent DNA. Low, noncytotoxic fluences rapidly produced an inhibition of DNA synthesis in half-replicon-size replication intermediates. With time, the inhibition produced by low fluences spread progressively to include multi-replicon-size intermediates. The results indicate that ultraviolet radiation inhibits the initiation of DNA synthesis in replicons. Higher cytotoxic fluences inhibited DNA synthesis in operating replicons. Xeroderma pigmentosum fibroblasts with deficiencies in DNA excision repair exhibited an inhibition of replicon initiation after low radiation fluences, indicating the effect was not solely dependent upon operation of the nucleotidyl excision repair pathway. Owing to their inability to remove pyrimidine dimers ahead of DNA growing points, the repair-deficient cells also were more sensitive than normal cells to the ultraviolet-induced inhibition of chain elongation. Xeroderma pigmentosum cells belonging to the variant class were even more sensitive to inhibition of chain elongation despite their ability to remove pyrimidine dimers. The analysis suggested that normal and repair-deficient human fibroblasts either are able to rapidly bypass certain dimers or these dimers are not recognized by the chain elongation machinery. (author)

  18. Inhibition of the ERK phosphorylation plays a role in terbinafine-induced p21 up-regulation and DNA synthesis inhibition in human vascular endothelial cells

    International Nuclear Information System (INIS)

    Ho, P.-Y.; Hsu, S.-P.; Liang, Y.-C.; Kuo, M.-L.; Ho, Y.-S.; Lee, W.-S.

    2008-01-01

    Previously, we showed that terbinafine (TB) induces cell-cycle arrest in cultured human umbilical vein endothelial cells (HUVEC) through an up-regulation of the p21 protein. The aim of this study is to delineate the molecular mechanisms underlying TB-induced increase of p21 protein. RT-PCR analysis demonstrated that the mRNA levels of p21 and p53 were increased in the TB-treated HUVEC. The p21 promoter activity was also increased by TB treatment. Transfection of HUVEC with p53 dominant negative (DN) abolished the TB-induced increases of p21 promoter activity and protein level, suggesting that the TB-induced increase of p21 is p53-dependent. Western blot analysis demonstrated that TB decreased the levels of phosphorylated extracellular signal-regulated kinase (ERK). Over-expression of mitogen-activated protein kinase (MEK)-1, the immediate upstream activator kinase of ERK, abolished the TB-induced increases of p21 and p53 protein and decrease of thymidine incorporation. The ERK inhibitor (PD98059) enhanced the TB-induced inhibition of thymidine incorporation into HUVEC. Taken together, these data suggest that the decrease of ERK activity plays a role in the TB-induced up-regulation of p21 in HUVEC. On the other hand, pretreatment of the cells with geranylgeraniol (GGOH), farnesol (FOH), or Ras inhibitor peptide did not affect the TB-induced decrease of thymidine incorporation. Taken together, our results suggest that TB might cause a decrease of MEK, which in turn up-regulates p53 through the inhibition of ERK phosphorylation, and finally causes an increase of p21 expression and cell-cycle arrest

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. 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

  1. Inhibition mechanisms of hemoglobin, immunoglobulin G, and whole blood in digital and real-time PCR.

    Science.gov (United States)

    Sidstedt, Maja; Hedman, Johannes; Romsos, Erica L; Waitara, Leticia; Wadsö, Lars; Steffen, Carolyn R; Vallone, Peter M; Rådström, Peter

    2018-04-01

    Blood samples are widely used for PCR-based DNA analysis in fields such as diagnosis of infectious diseases, cancer diagnostics, and forensic genetics. In this study, the mechanisms behind blood-induced PCR inhibition were evaluated by use of whole blood as well as known PCR-inhibitory molecules in both digital PCR and real-time PCR. Also, electrophoretic mobility shift assay was applied to investigate interactions between inhibitory proteins and DNA, and isothermal titration calorimetry was used to directly measure effects on DNA polymerase activity. Whole blood caused a decrease in the number of positive digital PCR reactions, lowered amplification efficiency, and caused severe quenching of the fluorescence of the passive reference dye 6-carboxy-X-rhodamine as well as the double-stranded DNA binding dye EvaGreen. Immunoglobulin G was found to bind to single-stranded genomic DNA, leading to increased quantification cycle values. Hemoglobin affected the DNA polymerase activity and thus lowered the amplification efficiency. Hemoglobin and hematin were shown to be the molecules in blood responsible for the fluorescence quenching. In conclusion, hemoglobin and immunoglobulin G are the two major PCR inhibitors in blood, where the first affects amplification through a direct effect on the DNA polymerase activity and quenches the fluorescence of free dye molecules, and the latter binds to single-stranded genomic DNA, hindering DNA polymerization in the first few PCR cycles. Graphical abstract PCR inhibition mechanisms of hemoglobin and immunoglobulin G (IgG). Cq quantification cycle, dsDNA double-stranded DNA, ssDNA single-stranded DNA.

  2. IL-33 inhibits RANKL-induced osteoclast formation through the regulation of Blimp-1 and IRF-8 expression

    Energy Technology Data Exchange (ETDEWEB)

    Kiyomiya, Hiroyasu [Division of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580 (Japan); Division of Oral and Maxillofacial Surgery, Department of Science of Physical Functions, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580 (Japan); Ariyoshi, Wataru; Okinaga, Toshinori [Division of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580 (Japan); Kaneuji, Takeshi [Division of Oral Medicine, Department of Science of Physical Functions, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580 (Japan); Mitsugi, Sho [Division of Oral and Maxillofacial Surgery, Department of Science of Physical Functions, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580 (Japan); Sakurai, Takuma [Division of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580 (Japan); Division of Oral and Maxillofacial Surgery, Department of Science of Physical Functions, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580 (Japan); Habu, Manabu [Division of Oral and Maxillofacial Surgery, Department of Science of Physical Functions, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580 (Japan); Yoshioka, Izumi [Division of Oral Medicine, Department of Science of Physical Functions, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580 (Japan); Tominaga, Kazuhiro [Division of Oral and Maxillofacial Surgery, Department of Science of Physical Functions, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580 (Japan); and others

    2015-05-01

    Interleukin (IL)-33 is a recently discovered proinflammatory cytokine that belongs to the IL-1 family. Several studies have reported that IL-33 inhibits osteoclast differentiation. However, the mechanism of IL-33 regulation of osteoclastogenesis remains unclear. In the present study, we examined the effect of IL-33 on osteoclast formation in vitro. IL-33 suppressed osteoclast formation in both mouse bone marrow cells and monocyte/macrophage cell line RAW264.7 cells induced by receptor activator of NF-κB ligand (RANKL) and/or macrophage stimulating factor (M-CSF). IL-33 also inhibited the expression of RANKL-induced nuclear factor of activated T-cell cytoplasmic 1 (NFATc1), thereby decreasing the expression of osteoclastogenesis-related marker genes, including Cathepsin K, Osteoclast stimulatory transmembrane protein (Oc-stamp) and Tartrate-resistant acid phosphatase (Trap). Blockage of IL-33-ST2 binding suppressed the IL-33-mediated inhibition of NFATc1. RANKL-induced B-lymphocyte-induced maturation protein-1 (Blimp-1) expression was also suppressed by IL-33, which was followed by the stimulation of anti-osteoclastic genes such as interferon regulatory factor-8 (IRF-8). These results suggest that IL-33-ST2 interactions down-regulate both RANKL-induced NFATc1 activation and osteoclast differentiation via the regulation of Blimp-1 and IRF-8 expression. - Highlights: • IL-33 inhibits RANKL-induced osteoclast formation. • IL-33 has inhibitory effect on the RANKL-induced NFATc1 expression. • IL-33-induced NFATc1 suppression depends on the regulation of Blimp-1 and IRF-8.

  3. IL-33 inhibits RANKL-induced osteoclast formation through the regulation of Blimp-1 and IRF-8 expression

    International Nuclear Information System (INIS)

    Kiyomiya, Hiroyasu; Ariyoshi, Wataru; Okinaga, Toshinori; Kaneuji, Takeshi; Mitsugi, Sho; Sakurai, Takuma; Habu, Manabu; Yoshioka, Izumi; Tominaga, Kazuhiro

    2015-01-01

    Interleukin (IL)-33 is a recently discovered proinflammatory cytokine that belongs to the IL-1 family. Several studies have reported that IL-33 inhibits osteoclast differentiation. However, the mechanism of IL-33 regulation of osteoclastogenesis remains unclear. In the present study, we examined the effect of IL-33 on osteoclast formation in vitro. IL-33 suppressed osteoclast formation in both mouse bone marrow cells and monocyte/macrophage cell line RAW264.7 cells induced by receptor activator of NF-κB ligand (RANKL) and/or macrophage stimulating factor (M-CSF). IL-33 also inhibited the expression of RANKL-induced nuclear factor of activated T-cell cytoplasmic 1 (NFATc1), thereby decreasing the expression of osteoclastogenesis-related marker genes, including Cathepsin K, Osteoclast stimulatory transmembrane protein (Oc-stamp) and Tartrate-resistant acid phosphatase (Trap). Blockage of IL-33-ST2 binding suppressed the IL-33-mediated inhibition of NFATc1. RANKL-induced B-lymphocyte-induced maturation protein-1 (Blimp-1) expression was also suppressed by IL-33, which was followed by the stimulation of anti-osteoclastic genes such as interferon regulatory factor-8 (IRF-8). These results suggest that IL-33-ST2 interactions down-regulate both RANKL-induced NFATc1 activation and osteoclast differentiation via the regulation of Blimp-1 and IRF-8 expression. - Highlights: • IL-33 inhibits RANKL-induced osteoclast formation. • IL-33 has inhibitory effect on the RANKL-induced NFATc1 expression. • IL-33-induced NFATc1 suppression depends on the regulation of Blimp-1 and IRF-8

  4. Cue-independent forgetting by intentional suppression - Evidence for inhibition as the mechanism of intentional forgetting.

    Science.gov (United States)

    Wang, Yingying; Cao, Zhijun; Zhu, Zijian; Cai, Huaqian; Wu, Yanhong

    2015-10-01

    People are able to intentionally forget unwanted memories through voluntary suppression, as revealed by the Think/No-think (TNT) paradigm. However, the nature of intentional forgetting is controversial. Findings that forgetting is independent of retrieval cues suggest that inhibitory control underlies intentional forgetting, but this result is also in line with an interference account. To resolve this controversy, we have directly contrasted the cue-independent characteristic of suppression versus interference. A double-cue paradigm was used, in which two different cues were associated with the same target during initial memory formation. Only one cue-target association received further interference/suppression training. In the test phase, when both cues were used to retrieve the target, we found that interference caused memory impairment that was restricted to the trained cue-target association, while suppression induced forgetting that generalized to the independent cue-target association. Therefore, the effect of suppression differs from that of interference. The cue-independent forgetting by voluntary suppression indicates that the target memory itself is inhibited, providing evidence that the underlying mechanism of suppression-induced forgetting is inhibitory control. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Presynaptic inhibition of spontaneous acetylcholine release induced by adenosine at the mouse neuromuscular junction.

    Science.gov (United States)

    De Lorenzo, Silvana; Veggetti, Mariela; Muchnik, Salomón; Losavio, Adriana

    2004-05-01

    1. At the mouse neuromuscular junction, adenosine (AD) and the A(1) agonist 2-chloro-N(6)-cyclopentyl-adenosine (CCPA) induce presynaptic inhibition of spontaneous acetylcholine (ACh) release by activation of A(1) AD receptors through a mechanism that is still unknown. To evaluate whether the inhibition is mediated by modulation of the voltage-dependent calcium channels (VDCCs) associated with tonic secretion (L- and N-type VDCCs), we measured the miniature end-plate potential (mepp) frequency in mouse diaphragm muscles. 2. Blockade of VDCCs by Cd(2+) prevented the effect of the CCPA. Nitrendipine (an L-type VDCC antagonist) but not omega-conotoxin GVIA (an N-type VDCC antagonist) blocked the action of CCPA, suggesting that the decrease in spontaneous mepp frequency by CCPA is associated with an action on L-type VDCCs only. 3. As A(1) receptors are coupled to a G(i/o) protein, we investigated whether the inhibition of PKA or the activation of PKC is involved in the presynaptic inhibition mechanism. Neither N-(2[p-bromocinnamylamino]-ethyl)-5-isoquinolinesulfonamide (H-89, a PKA inhibitor), nor 1-(5-isoquinolinesulfonyl)-2-methyl-piperazine (H-7, a PKC antagonist), nor phorbol 12-myristate 13-acetate (PHA, a PKC activator) modified CCPA-induced presynaptic inhibition, suggesting that these second messenger pathways are not involved. 4. The effect of CCPA was eliminated by the calmodulin antagonist N-(6-aminohexil)-5-chloro-1-naphthalenesulfonamide hydrochloride (W-7) and by ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid-acetoxymethyl ester epsilon6TDelta-BM, which suggests that the action of CCPA to modulate L-type VDCCs may involve Ca(2+)-calmodulin. 5. To investigate the action of CCPA on diverse degrees of nerve terminal depolarization, we studied its effect at different external K(+) concentrations. The effect of CCPA on ACh secretion evoked by 10 mm K(+) was prevented by the P/Q-type VDCC antagonist omega-agatoxin IVA. 6. CCPA failed to

  6. Genistein inhibited ammonia induced astrocyte swelling by inhibiting NF-κB activation-mediated nitric oxide formation.

    Science.gov (United States)

    Dai, Hongliang; Jia, Guizhi; Wang, Wei; Liang, Chunguang; Han, Siyu; Chu, Minghui; Mei, Xifan

    2017-06-01

    Our previous study has indicated the involvement of epidermal growth factor receptor (EGFR) transactivation in ammonia-induced astrocyte swelling, which represents a major pathogenesis of brain edema in hepatic encephalopathy. In this study, we examined the effect of genistein, a naturally occurred broad-spectrum protein tyrosine kinase (PTK) inhibitor, on ammonia-induced cell swelling. We found that genistein pretreatment significantly prevented ammonia-induced astrocyte swelling. Mechanistically, ammonia triggered EGFR/extracellular signal-regulated kinase (ERK) association and subsequent ERK phosphorylation were alleviated by genistein pretreatment. Moreover, ammonia-induced NF-κB nuclear location, iNOS expression, and consequent NO production were all prevented by AG1478 and genistein pretreatment. This study suggested that genistein could alleviate ammonia-induced astrocyte swelling, which may be, at least partly, related to its PTK-inhibiting activity and repression of NF-κB mediated iNOS-derived NO accumulation.

  7. CD147-induced cell proliferation is associated with Smad4 signal inhibition.

    Science.gov (United States)

    Qin, Hui; Rasul, Azhar; Li, Xin; Masood, Muqaddas; Yang, Guang; Wang, Na; Wei, Wei; He, Xi; Watanabe, Nobumoto; Li, Jiang; Li, Xiaomeng

    2017-09-15

    CD147 is a multifunctional trans-membrane glycoprotein, which is highly expressed in many cancers. However, the mechanism by which CD147 modulates cell proliferation is not fully understood. The aim of this study is to investigate the role of CD147 in cell proliferation associated with the TGF-β/Smad4 signaling pathway. Here, we used cell viability and clone formation assays in LNCaP prostate cancer cells to demonstrate that CD147 promotes cell proliferation. The luciferase assay and western blotting show that silencing CD147 using shRNA enhances transcription and expression of p21 WAF1 . Using immunofluorescence and nuclear-cytoplasmic separation, we show that this is primarily attributed to transport of Smad4 from the cytoplasm to nucleus. Other assays (GST pull-down, co-immunoprecipitation and immunofluorescence) demonstrate that Smad4 is a new interaction partner of CD147, with the Smad4 MH2 domain and CD147 intracellular domain (CD147-ICD) being involved in the interaction. Furthermore, we report that a phosphoserine (pSer) in CD147 (pSer252) is responsible for this interaction and inhibition of the Smad4/p21 WAF1 signal that promotes cell proliferation. Our results provide a novel molecular mechanism for CD147-induced cell proliferation associated with Smad4 signal inhibition. Copyright © 2017. Published by Elsevier Inc.

  8. Chinese herbal medicine Shenqi Detoxification Granule inhibits fibrosis in adenine induced chronic renal failure rats.

    Science.gov (United States)

    Peng, Min; Cai, Pingping; Ma, Hongbo; Meng, Hongyan; Xu, Yuan; Zhang, Xiaoyi; Si, Guomin

    2014-01-01

    Progressive fibrosis accompanies all chronic renal disease, connective tissue growth factor (CTGF,) and platelet-derived growth factor-B, (PDGF-B,) play important roles in extra-cellular matrix abnormal accumulation, while endothelin-1 (ET-1) nitric oxide (NO,) are related to endothelial dysfunction, which mediates the progression of renal fibrosis. Shenqi Detoxification Granule (SDG), a traditional Chinese herbal formula, has been used for treatment of chronic renal failure in clinic for many years. In order to evaluate the efficacy, and explore the mechanism of SDG to inhibit the progression of renal fibrosis, study was carried out using the adenine-induced Wister rats as the CRF model, and losartan as postive control drug. Levels of serum creatinine [Scr], and blood urea nitrogen (BUN), albumin (ALB), 24hrs, urine protein (24hUP), triacylglycerol (TG), and cholesterol (CHO), together with ET-1, and NO were detected. Pathological changes of renal tissues were observed by HE, staining. In addition, CTGF and PDGF-B expression were analyzed by immuno-histo-chemistry. The results indicated that SDG can effectively reduce Scr, BUN, 24hUP, TG, and CHO levels, increase ALB levels, inhibit renal tissue damage in CRF rats, and the mechanism maybe reduce PDGF-B, CTGF expression and ET-1/NO. Shenqi Detoxification Granule is a beneficial treatment for chronic renal failure.

  9. Lead inhibition of DNA-binding mechanism of Cys(2)His(2) zinc finger proteins.

    Science.gov (United States)

    Hanas, J S; Rodgers, J S; Bantle, J A; Cheng, Y G

    1999-11-01

    The association of lead with chromatin in cells suggests that deleterious metal effects may in part be mediated through alterations in gene function. To elucidate if and how lead may alter DNA binding of cysteine-rich zinc finger proteins, lead ions were analyzed for their ability to alter the DNA binding mechanism of the Cys(2)His(2) zinc finger protein transcription factor IIIA (TFIIIA). As assayed by DNase I protection, the interaction of TFIIIA with the 50-bp internal control region of the 5S ribosomal gene was partially inhibited by 5 microM lead ions and completely inhibited by 10 to 20 microM lead ions. Preincubation of free TFIIIA with lead resulted in DNA-binding inhibition, whereas preincubation of a TFIIIA/5S RNA complex with lead did not result in DNA-binding inhibition. Because 5S RNA binds TFIIIA zinc fingers, this result is consistent with an inhibition mechanism via lead binding to zinc fingers. The complete loss of DNase I protection on the 5S gene indicates the mechanism of inhibition minimally involves the N-terminal fingers of TFIIIA. Inhibition was not readily reversible and occurred in the presence of an excess of beta-mercaptoethanol. Inhibition kinetics were fast, progressing to completion in approximately 5 min. Millimolar concentrations of sulfhydryl-specific arsenic ions were not inhibitory for TFIIIA binding. Micromolar concentrations of lead inhibited DNA binding by Sp1, another Cys(2)His(2) finger protein, but not by the nonfinger protein AP2. Inhibition of Cys(2)His(2) zinc finger transcription factors by lead ions at concentrations near those known to have deleterious physiological effects points to new molecular mechanisms for lead toxicity in promoting disease.

  10. Inhibition of lipopolysaccharide induced acute inflammation in lung by chlorination.

    Science.gov (United States)

    Zhang, Jinshan; Xue, Jinling; Xu, Bi; Xie, Jiani; Qiao, Juan; Lu, Yun

    2016-02-13

    Lipopolysaccharide (LPS, also called endotoxin) is a pro-inflammatory constituent of gram negative bacteria and cyanobacteria, which causes a potential health risk in the process of routine urban application of reclaimed water, such as car wash, irrigation, scenic water refilling, etc. Previous studies indicated that the common disinfection treatment, chlorination, has little effect on endotoxin activity removal measured by Limulus amebocyte lysate (LAL) assay. However, in this study, significant decrease of acute inflammatory effects was observed in mouse lung, while LAL assay still presented a moderate increase of endotoxin activity. To explore the possible mechanisms, the nuclear magnetic resonance (NMR) results showed the chlorination happened in alkyl chain of LPS molecules, which could affect the interaction between LPS and LPS-binding protein. Also the size of LPS aggregates was found to drop significantly after treatment, which could be another results of chlorination caused polarity change. In conclusion, our observation demonstrated that chlorination is effective to reduce the LPS induced inflammation in lung, and it is recommended to use health effect-based methods to assess risk removal of water treatment technologies. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. IGF-1 protects against Aβ25-35-induced neuronal cell death via inhibition of PUMA expression and Bax activation.

    Science.gov (United States)

    Hou, Xunyao; Jin, Yan; Chen, Jian; Hong, Yan; Luo, Dingzhen; Yin, Qingqing; Liu, Xueping

    2017-01-10

    Amyloid-β-peptide (Aβ) is considered to be the toxic species in AD and causes cell death in the affected areas of patient's brain. Insulin-like growth factor 1 (IGF-1) has been reported to attenuate Aβ toxicity in neuronal cells. However, the molecular mechanisms involved in the neuroprotective function of IGF-1 remain largely unknown. In the present study, we for the first time demonstrated that IGF-1 protects against Aβ-induced neurotoxicity via inhibition of PUMA expression and Bax activation. We found that IGF-1 could activate Akt, which in turn inhibited Aβ-induced FOXO3a nuclear translocation and thus decreased the binding ability of FOXO3a to PUMA promoter, leading to decreased PUMA expression. In addition, IGF-1 inhibited the translocation of Bax to the mitochondria induced by Aβ. Notably, addition of wortmannin, a specific inhibitor of PI3K, significantly abolished the neuroprotective effect of IGF-1, suggesting that IGF-1 exerts its anti-apoptotic effect depend on PI3K activity. Our findings may provide new insights into molecular mechanisms mediated by IGF-1 in cell survival against Aβ-induced apoptosis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Mechanisms of cisplatin-induced muscle atrophy

    International Nuclear Information System (INIS)

    Sakai, Hiroyasu; Sagara, Atsunobu; Arakawa, Kazuhiko; Sugiyama, Ryoto; Hirosaki, Akiko; Takase, Kazuhide; Jo, Ara; Sato, Ken; Chiba, Yoshihiko; Yamazaki, Mitsuaki; Matoba, Motohiro; Narita, Minoru

    2014-01-01

    Fatigue is the most common side effect of chemotherapy. However, the mechanisms of “muscle fatigue” induced by anti-cancer drugs are not fully understood. We therefore investigated the muscle-atrophic effect of cisplatin, a platinum-based anti-cancer drug, in mice. C57BL/6J mice were treated with cisplatin (3 mg/kg, i.p.) or saline for 4 consecutive days. On Day 5, hindlimb and quadriceps muscles were isolated from mice. The loss of body weight and food intake under the administration of cisplatin was the same as those in a dietary restriction (DR) group. Under the present conditions, the administration of cisplatin significantly decreased not only the muscle mass of the hindlimb and quadriceps but also the myofiber diameter, compared to those in the DR group. The mRNA expression levels of muscle atrophy F-box (MAFbx), muscle RING finger-1 (MuRF1) and forkhead box O3 (FOXO3) were significantly and further increased by cisplatin treated group, compared to DR. Furthermore, the mRNA levels of myostatin and p21 were significantly upregulated by the administration of cisplatin, compared to DR. On the other hand, the phosphorylation of Akt and FOXO3a, which leads to the blockade of the upregulation of MuRF1 and MAFbx, was significantly and dramatically decreased by cisplatin. These findings suggest that the administration of cisplatin increases atrophic gene expression, and may lead to an imbalance between protein synthesis and protein degradation pathways, which would lead to muscle atrophy. This phenomenon could, at least in part, explain the mechanism of cisplatin-induced muscle fatigue. - Highlights: • Cisplatin decreased mass and myofiber diameter in quadriceps muscle. • The mRNA of MAFbx, MuRF1 and FOXO3 were increased by the cisplatin. • The mRNA of myostatin and p21 were upregulated by cisplatin. • The phosphorylation of Akt and FOXO3a was decreased by cisplatin

  13. Mechanisms of cisplatin-induced muscle atrophy

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Hiroyasu, E-mail: sakai@hoshi.ac.jp [Department of Pharmacology, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Division of Pharmacy Professional Development and Research, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Sagara, Atsunobu; Arakawa, Kazuhiko; Sugiyama, Ryoto; Hirosaki, Akiko; Takase, Kazuhide; Jo, Ara [Department of Pharmacology, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Sato, Ken [Department of Pharmacology, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Division of Pharmacy Professional Development and Research, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Chiba, Yoshihiko [Department of Biology, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Yamazaki, Mitsuaki [Department of Anesthesiology, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, 2630 Sugitani, Toyama-shi, Toyama 9300194 (Japan); Matoba, Motohiro [Department of Palliative Medicine and Psychooncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 1040045 (Japan); Narita, Minoru, E-mail: narita@hoshi.ac.jp [Department of Pharmacology, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan)

    2014-07-15

    Fatigue is the most common side effect of chemotherapy. However, the mechanisms of “muscle fatigue” induced by anti-cancer drugs are not fully understood. We therefore investigated the muscle-atrophic effect of cisplatin, a platinum-based anti-cancer drug, in mice. C57BL/6J mice were treated with cisplatin (3 mg/kg, i.p.) or saline for 4 consecutive days. On Day 5, hindlimb and quadriceps muscles were isolated from mice. The loss of body weight and food intake under the administration of cisplatin was the same as those in a dietary restriction (DR) group. Under the present conditions, the administration of cisplatin significantly decreased not only the muscle mass of the hindlimb and quadriceps but also the myofiber diameter, compared to those in the DR group. The mRNA expression levels of muscle atrophy F-box (MAFbx), muscle RING finger-1 (MuRF1) and forkhead box O3 (FOXO3) were significantly and further increased by cisplatin treated group, compared to DR. Furthermore, the mRNA levels of myostatin and p21 were significantly upregulated by the administration of cisplatin, compared to DR. On the other hand, the phosphorylation of Akt and FOXO3a, which leads to the blockade of the upregulation of MuRF1 and MAFbx, was significantly and dramatically decreased by cisplatin. These findings suggest that the administration of cisplatin increases atrophic gene expression, and may lead to an imbalance between protein synthesis and protein degradation pathways, which would lead to muscle atrophy. This phenomenon could, at least in part, explain the mechanism of cisplatin-induced muscle fatigue. - Highlights: • Cisplatin decreased mass and myofiber diameter in quadriceps muscle. • The mRNA of MAFbx, MuRF1 and FOXO3 were increased by the cisplatin. • The mRNA of myostatin and p21 were upregulated by cisplatin. • The phosphorylation of Akt and FOXO3a was decreased by cisplatin.

  14. Maximum skin hyperaemia induced by local heating: possible mechanisms.

    Science.gov (United States)

    Gooding, Kim M; Hannemann, Michael M; Tooke, John E; Clough, Geraldine F; Shore, Angela C

    2006-01-01

    Maximum skin hyperaemia (MH) induced by heating skin to > or = 42 degrees C is impaired in individuals at risk of diabetes and cardiovascular disease. Interpretation of these findings is hampered by the lack of clarity of the mechanisms involved in the attainment of MH. MH was achieved by local heating of skin to 42-43 degrees C for 30 min, and assessed by laser Doppler fluximetry. Using double-blind, randomized, placebo-controlled crossover study designs, the roles of prostaglandins were investigated by inhibiting their production with aspirin and histamine, with the H1 receptor antagonist cetirizine. The nitric oxide (NO) pathway was blocked by the NO synthase inhibitor, NG-nitro-L-arginine methyl esther (L-NAME), and enhanced by sildenafil (prevents breakdown of cGMP). MH was not altered by aspirin, cetirizine or sildenafil, but was reduced by L-NAME: median placebo 4.48 V (25th, 75th centiles: 3.71, 4.70) versus L-NAME 3.25 V (3.10, 3.80) (p = 0.008, Wilcoxon signed rank test). Inhibition of NO production (L-NAME) resulted in a more rapid reduction in hyperaemia after heating (p = 0.011), whereas hyperaemia was prolonged in the presence of sildenafil (p = 0.003). The increase in skin blood flow was largely confined to the directly heated area, suggesting that the role of heat-induced activation of the axon reflex was small. NO, but not prostaglandins, histamine or an axon reflex, contributes to the increase in blood flow on heating and NO is also a component of the resolution of MH after heating. Copyright 2006 S. Karger AG, Basel.

  15. Dimethyl phenyl piperazine iodide (DMPP) induces glioma regression by inhibiting angiogenesis

    Energy Technology Data Exchange (ETDEWEB)

    He, Yan-qing; Li, Yan; Wang, Xiao-yu [Key Laboratory for Regenerative Medicine of the Ministry of Education, Division of Histology and Embryology, Medical College, Jinan University, Guangzhou 510632 (China); He, Xiao-dong [Institute of Vascular Biological Sciences, Guangdong Pharmaceutical University, Guangzhou 510006 (China); Jun, Li [Guangdong Provincial Key Laboratory of Bioengineering Medicine, National Engineering Research Centre of Genetic Medicine, College of Life Science and Technology, Jinan University, Guangzhou 510632 (China); Chuai, Manli [Division of Cell and Developmental Biology, University of Dundee, Dundee, DD1 5EH (United Kingdom); Lee, Kenneth Ka Ho [Key Laboratory for Regenerative Medicine of the Ministry of Education, School of Biomedical Sciences, Chinese University of Hong Kong, Shatin (Hong Kong); Wang, Ju [Guangdong Provincial Key Laboratory of Bioengineering Medicine, National Engineering Research Centre of Genetic Medicine, College of Life Science and Technology, Jinan University, Guangzhou 510632 (China); Wang, Li-jing, E-mail: wanglijing62@163.com [Institute of Vascular Biological Sciences, Guangdong Pharmaceutical University, Guangzhou 510006 (China); Yang, Xuesong, E-mail: yang_xuesong@126.com [Key Laboratory for Regenerative Medicine of the Ministry of Education, Division of Histology and Embryology, Medical College, Jinan University, Guangzhou 510632 (China)

    2014-01-15

    1,1-Dimethyl-4-phenyl piperazine iodide (DMPP) is a synthetic nicotinic acetylcholine receptor (nAChR) agonist that could reduce airway inflammation. In this study, we demonstrated that DMPP could dramatically inhibit glioma size maintained on the chick embryonic chorioallantoic membrane (CAM). We first performed MTT and BrdU incorporation experiments on U87 glioma cells in vitro to understand the mechanism involved. We established that DMPP did not significantly affect U87 cell proliferation and survival. We speculated that DMPP directly caused the tumor to regress by affecting the vasculature in and around the implanted tumor on our chick CAM model. Hence, we conducted detailed analysis of DMPP's inhibitory effects on angiogenesis. Three vasculogenesis and angiogenesis in vivo models were used in the study which included (1) early chick blood islands formation, (2) chick yolk-sac membrane (YSW) and (3) CAM models. The results revealed that DMPP directly suppressed all developmental stages involved in vasculogenesis and angiogenesis – possibly by acting through Ang-1 and HIF-2α signaling. In sum, our results show that DMPP could induce glioma regression grown on CAM by inhibiting vasculogenesis and angiogenesis. - Highlights: ●We demonstrated that DMPP inhibited the growth of glioma cells on chick CAM. ●DMPP did not significantly affect the proliferation and survival of U87 cells. ●We revealed that DMPP suppressed vasculogenesis and angiogenesis in chick embryo. ●Angiogenesis in chick CAM was inhibited by DMPP via most probably Ang-1 and HIF-2α. ●DMPP could be potentially developed as an anti-tumor drug in the future.

  16. Ginkgo Biloba Extract Kaempferol Inhibits Cell Proliferation and Induces Apoptosis in Pancreatic Cancer Cells

    Science.gov (United States)

    Zhang, Yuqing; Chen, Aaron Y.; Li, Min; Chen, Changyi; Yao, Qizhi

    2010-01-01

    Background Kaempferol is one of the most important constituents in ginkgo flavonoids. Recent studies indicate kaempferol may have anti-tumor activities. The objective in this study was to determine the effect and mechanisms of kaempferol on pancreatic cancer cell proliferation and apoptosis. Materials and Methods Pancreatic cancer cell lines MIA PaCa-2 and Panc-1 were treated with Kampferol, and the inhibitory effects of kaempferol on pancreatic cancer cell proliferation were examined by direct cell counting, 3H-thymidine incorporation and MTS assay. Lactate dehydrogenase (LDH) release from cells was determined as an index of cytotoxicity. Apoptosis was analyzed by TUNEL assay. Results Upon the treatment with 70 μM kaempferol for 4 days, MIA PaCa-2 cell proliferation was significantly inhibited by 79% and 45.7% as determined by direct cell counting and MTS assay, respectively, compared with control cells (Pkaempferol significantly inhibited Panc-1 cell proliferation. Kaempferol treatment also significantly reduced 3H-thymidine incorporation in both MIA PaCa-2 and Panc-1 cells. Combination treatment of low concentrations of kaempferol and 5-fluorouracil (5-FU) showed an additive effect on the inhibition of MIA PaCa-2 cell proliferation. Furthermore, kaempferol had a significantly less cytotoxicity than 5-FU in normal human pancreatic ductal epithelial cells (P=0.029). In both MIA PaCa-2 and Panc-1 cells, apoptotic cell population was increased when treated with kaempferol in a concentration-dependent manner. Conclusions Ginkgo biloba extract kaempferol effectively inhibits pancreatic cancer cell proliferation and induces cancer cell apoptosis, which may sensitize pancreatic tumor cells to chemotherapy. Kaempferol may have clinical applications as adjuvant therapy in the treatment of pancreatic cancer. PMID:18570926

  17. Dimethyl phenyl piperazine iodide (DMPP) induces glioma regression by inhibiting angiogenesis

    International Nuclear Information System (INIS)

    He, Yan-qing; Li, Yan; Wang, Xiao-yu; He, Xiao-dong; Jun, Li; Chuai, Manli; Lee, Kenneth Ka Ho; Wang, Ju; Wang, Li-jing; Yang, Xuesong

    2014-01-01

    1,1-Dimethyl-4-phenyl piperazine iodide (DMPP) is a synthetic nicotinic acetylcholine receptor (nAChR) agonist that could reduce airway inflammation. In this study, we demonstrated that DMPP could dramatically inhibit glioma size maintained on the chick embryonic chorioallantoic membrane (CAM). We first performed MTT and BrdU incorporation experiments on U87 glioma cells in vitro to understand the mechanism involved. We established that DMPP did not significantly affect U87 cell proliferation and survival. We speculated that DMPP directly caused the tumor to regress by affecting the vasculature in and around the implanted tumor on our chick CAM model. Hence, we conducted detailed analysis of DMPP's inhibitory effects on angiogenesis. Three vasculogenesis and angiogenesis in vivo models were used in the study which included (1) early chick blood islands formation, (2) chick yolk-sac membrane (YSW) and (3) CAM models. The results revealed that DMPP directly suppressed all developmental stages involved in vasculogenesis and angiogenesis – possibly by acting through Ang-1 and HIF-2α signaling. In sum, our results show that DMPP could induce glioma regression grown on CAM by inhibiting vasculogenesis and angiogenesis. - Highlights: ●We demonstrated that DMPP inhibited the growth of glioma cells on chick CAM. ●DMPP did not significantly affect the proliferation and survival of U87 cells. ●We revealed that DMPP suppressed vasculogenesis and angiogenesis in chick embryo. ●Angiogenesis in chick CAM was inhibited by DMPP via most probably Ang-1 and HIF-2α. ●DMPP could be potentially developed as an anti-tumor drug in the future

  18. Glucocorticoid Induced Leucine Zipper inhibits apoptosis of cardiomyocytes by doxorubicin

    International Nuclear Information System (INIS)

    Aguilar, David; Strom, Joshua; Chen, Qin M.

    2014-01-01

    Doxorubicin (Dox) is an indispensable chemotherapeutic agent for the treatment of various forms of neoplasia such as lung, breast, ovarian, and bladder cancers. Cardiotoxicity is a major concern for patients receiving Dox therapy. Previous work from our laboratory indicated that glucocorticoids (GCs) alleviate Dox-induced apoptosis in cardiomyocytes. Here we have found Glucocorticoid-Induced Leucine Zipper (GILZ) to be a mediator of GC-induced cytoprotection. GILZ was found to be induced in cardiomyocytes by GC treatment. Knocking down of GILZ using siRNA resulted in cancelation of GC-induced cytoprotection against apoptosis by Dox treatment. Overexpressing GILZ by transfection was able to protect cells from apoptosis induced by Dox as measured by caspase activation, Annexin V binding and morphologic changes. Western blot analyses indicate that GILZ overexpression prevented cytochrome c release from mitochondria and cleavage of caspase-3. When bcl-2 family proteins were examined, we found that GILZ overexpression causes induction of the pro-survival protein Bcl-xL. Since siRNA against Bcl-xL reverses GC induced cytoprotection, Bcl-xL induction represents an important event in GILZ-induced cytoprotection. Our data suggest that GILZ functions as a cytoprotective gene in cardiomyocytes. - Highlights: • Corticosteroids act as a cytoprotective agent in cardiomyocytes • Corticosteroids induce GILZ expression in cardiomyocytes • Elevated GILZ results in resistance against apoptosis induced by doxorubicin • GILZ induces Bcl-xL protein without inducing Bcl-xL mRNA

  19. Schedule-dependent inhibition of hypoxia-inducible factor-1alpha protein accumulation, angiogenesis, and tumor growth by topotecan in U251-HRE glioblastoma xenografts.

    Science.gov (United States)

    Rapisarda, Annamaria; Zalek, Jessica; Hollingshead, Melinda; Braunschweig, Till; Uranchimeg, Badarch; Bonomi, Carrie A; Borgel, Suzanne D; Carter, John P; Hewitt, Stephen M; Shoemaker, Robert H; Melillo, Giovanni

    2004-10-01

    We have previously shown that topotecan, a topoisomerase I poison, inhibits hypoxia-inducible factor (HIF)-1alpha protein accumulation by a DNA damage-independent mechanism. Here, we report that daily administration of topotecan inhibits HIF-1alpha protein expression in U251-HRE glioblastoma xenografts. Concomitant with HIF-1alpha inhibition, topotecan caused a significant tumor growth inhibition associated with a marked decrease of angiogenesis and expression of HIF-1 target genes in tumor tissue. These results provide a compelling rationale for testing topotecan in clinical trials to target HIF-1 in cancer patients.

  20. Inhibition of Estrogen-induced Growth of Breast Cancer by Targeting Mitochondrial Oxidants

    National Research Council Canada - National Science Library

    Roy, Deodutta; Felty, Quentin; Kunkle, Brian

    2008-01-01

    ...) Anchorage-independent cell growth, and (c) tumor spheroid formation using new 3D HuBiogel bioassay whether estrogen induced conversion of normal cells to transformed cells is inhibited by treatment with antioxidants, over expression of MnSOD...

  1. Skin protective effect of guava leaves against UV-induced melanogenesis via inhibition of ORAI1 channel and tyrosinase activity.

    Science.gov (United States)

    Lee, Dong-Ung; Weon, Kwon Yeon; Nam, Da-Yeong; Nam, Joo Hyun; Kim, Woo Kyung

    2016-12-01

    Ultraviolet (UV) irradiation is a major environmental factor affecting photoageing, which is characterized by skin wrinkle formation and hyperpigmentation. Although many factors are involved in the photoageing process, UV irradiation is thought to play a major role in melanogenesis. Tyrosinase is the key enzyme in melanin synthesis; therefore, many whitening agents target tyrosinase through various mechanisms, such as direct interference of tyrosinase catalytic activity or inhibition of tyrosinase mRNA expression. Furthermore, the highly selective calcium channel ORAI1 has been shown to be associated with UV-induced melanogenesis. Thus, ORAI1 antagonists may have applications in the prevention of melanogenesis. Here, we aimed to identify the antimelanogenesis agents from methanolic extract of guava leaves (Psidium guajava) that can inhibit tyrosinase and ORAI1 channel. The n-butanol (47.47%±7.503% inhibition at 10 μg/mL) and hexane (57.88%±7.09% inhibition at 10 μg/mL) fractions were found to inhibit ORAI1 channel activity. In addition, both fractions showed effective tyrosinase inhibitory activity (68.3%±0.50% and 56.9%±1.53% inhibition, respectively). We also confirmed that the hexane fraction decreased the melanin content induced by UVB irradiation and the ET-1-induced melanogenesis in murine B16F10 melanoma cells. These results suggest that the leaves of P. guajava can be used to protect against direct and indirect UV-induced melanogenesis. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Cellular and molecular mechanisms of alcohol-induced osteopenia.

    Science.gov (United States)

    Luo, Zhenhua; Liu, Yao; Liu, Yitong; Chen, Hui; Shi, Songtao; Liu, Yi

    2017-12-01

    Alcoholic beverages are widely consumed, resulting in a staggering economic cost in different social and cultural settings. Types of alcohol consumption vary from light occasional to heavy, binge drinking, and chronic alcohol abuse at all ages. In general, heavy alcohol consumption is widely recognized as a major epidemiological risk factor for chronic diseases and is detrimental to many organs and tissues, including bones. Indeed, recent findings demonstrate that alcohol has a dose-dependent toxic effect in promoting imbalanced bone remodeling. This imbalance eventually results in osteopenia, an established risk factor for osteoporosis. Decreased bone mass and strength are major hallmarks of osteopenia, which is predominantly attributed not only to inhibition of bone synthesis but also to increased bone resorption through direct and indirect pathways. In this review, we present knowledge to elucidate the epidemiology, potential pathogenesis, and major molecular mechanisms and cellular effects that underlie alcoholism-induced bone loss in osteopenia. Novel therapeutic targets for correcting alcohol-induced osteopenia are also reviewed, such as modulation of proinflammatory cytokines and Wnt and mTOR signaling and the application of new drugs.

  3. Inhibition of thromboxane synthase induces lung cancer cell death via increasing the nuclear p27

    International Nuclear Information System (INIS)

    Leung, Kin Chung; Hsin, Michael K.Y.; Chan, Joey S.Y.; Yip, Johnson H.Y.; Li, Mingyue; Leung, Billy C.S.; Mok, Tony S.K.; Warner, Timothy D.; Underwood, Malcolm J.; Chen, George G.

    2009-01-01

    The role of thromboxane in lung carcinogenesis is not clearly known, though thromboxane B2 (TXB 2 ) level is increased and antagonists of thromboxane receptors or TXA2 can induce apoptosis of lung cancer cells. p27, an atypical tumor suppressor, is normally sequestered in the nucleus. The increased nuclear p27 may result in apoptosis of tumor cells. We hypothesize that the inhibition of thromboxane synthase (TXS) induces the death of lung cancer cells and that such inhibition is associated with the nuclear p27 level. Our experiment showed that the inhibition of TXS significantly induced the death or apoptosis in lung cancer cells. The activity of TXS was increased in lung cancer. The nuclear p27 was remarkably reduced in lung cancer tissues. The inhibition of TXS caused the cell death and apoptosis of lung cancer cells, likely via the elevation of the nuclear p27 since the TXS inhibition promoted the nuclear p27 level and the inhibition of p27 by its siRNA recovered the cell death induced by TXS inhibition. Collectively, lung cancer cells produce high levels of TXB 2 but their nuclear p27 is markedly reduced. The inhibition of TXS results in the p27-related induction of cell death in lung cancer cells.

  4. Lithium ions induce prestalk-associated gene expression and inhibit prespore gene expression in Dictyostelium discoideum

    NARCIS (Netherlands)

    Peters, Dorien J.M.; Lookeren Campagne, Michiel M. van; Haastert, Peter J.M. van; Spek, Wouter; Schaap, Pauline

    1989-01-01

    We investigated the effect of Li+ on two types of cyclic AMP-regulated gene expression and on basal and cyclic AMP-stimulated inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) levels. Li+ effectively inhibits cyclic AMP-induced prespore gene expression, half-maximal inhibition occurring at about 2mM-LiCl.

  5. Inhibition of thromboxane synthase induces lung cancer cell death via increasing the nuclear p27

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Kin Chung; Hsin, Michael K.Y.; Chan, Joey S.Y.; Yip, Johnson H.Y.; Li, Mingyue; Leung, Billy C.S. [Department of Surgery, The Chinese University of Hong Kong, Shatin, New Territories (Hong Kong); Mok, Tony S.K. [Department of Clinical Oncology, The Chinese University of Hong Kong, Shatin, New Territories (Hong Kong); Warner, Timothy D. [The William Harvey Research Institute, Queen Mary University of London, London (United Kingdom); Underwood, Malcolm J. [Department of Surgery, The Chinese University of Hong Kong, Shatin, New Territories (Hong Kong); Chen, George G., E-mail: gchen@cuhk.edu.hk [Department of Surgery, The Chinese University of Hong Kong, Shatin, New Territories (Hong Kong)

    2009-10-15

    The role of thromboxane in lung carcinogenesis is not clearly known, though thromboxane B2 (TXB{sub 2}) level is increased and antagonists of thromboxane receptors or TXA2 can induce apoptosis of lung cancer cells. p27, an atypical tumor suppressor, is normally sequestered in the nucleus. The increased nuclear p27 may result in apoptosis of tumor cells. We hypothesize that the inhibition of thromboxane synthase (TXS) induces the death of lung cancer cells and that such inhibition is associated with the nuclear p27 level. Our experiment showed that the inhibition of TXS significantly induced the death or apoptosis in lung cancer cells. The activity of TXS was increased in lung cancer. The nuclear p27 was remarkably reduced in lung cancer tissues. The inhibition of TXS caused the cell death and apoptosis of lung cancer cells, likely via the elevation of the nuclear p27 since the TXS inhibition promoted the nuclear p27 level and the inhibition of p27 by its siRNA recovered the cell death induced by TXS inhibition. Collectively, lung cancer cells produce high levels of TXB{sub 2} but their nuclear p27 is markedly reduced. The inhibition of TXS results in the p27-related induction of cell death in lung cancer cells.

  6. Indirubin-3′-monoxime suppresses amyloid-beta-induced apoptosis by inhibiting tau hyperphosphorylation

    Institute of Scientific and Technical Information of China (English)

    Shu-gang Zhang; Xiao-shan Wang; Ying-dong Zhang; Qing Di; Jing-ping Shi; Min Qian; Li-gang Xu; Xing-jian Lin; Jie Lu

    2016-01-01

    Indirubin-3′-monoxime is an effective inhibitor of cyclin-dependent protein kinases, and may play an obligate role in neuronal apopto-sis in Alzheimer’s disease. Here, we found that indirubin-3′-monoxime improved the morphology and increased the survival rate of SH-SY5Y cells exposed to amyloid-beta 25–35 (Aβ25–35), and also suppressed apoptosis by reducing tau phosphorylation at Ser199 and Thr205. Furthermore, indirubin-3′-monoxime inhibited phosphorylation of glycogen synthase kinase-3β (GSK-3β). Our results suggest that in-dirubin-3′-monoxime reduced Aβ25–35-induced apoptosis by suppressing tau hyperphosphorylationvia a GSK-3β-mediated mechanism. Indirubin-3′-monoxime is a promising drug candidate for Alzheimer’s disease.

  7. The effect of nitric oxide synthase inhibition on histamine induced headache and arterial dilatation in migraineurs

    DEFF Research Database (Denmark)

    Lassen, L H; Christiansen, I; Iversen, Helle Klingenberg

    2003-01-01

    -decrease in MCA blood velocity, or dilatation of neither the temporal nor the radial artery. L-NMMA constricted the temporal artery by 8% before histamine infusion, whereas the radial artery was unaffected. The temporal artery dilated 4-5 times more than the radial artery during histamine infusion. In conclusion...... the use of a NOS inhibitor in the highest possible dose did not block the histamine-induced headache response or arterial dilatation. Either the concentration of L-NMMA reaching the smooth muscle cell was insufficient or, histamine dilates arteries and causes headache via NO independent mechanisms. Our...... results showed for the first time a craniospecificity for the vasodilating effect of histamine and for the arterial effects of NOS inhibition....

  8. Dasatinib inhibits both osteoclast activation and prostate cancer PC-3-cell-induced osteoclast formation.

    Science.gov (United States)

    Araujo, John C; Poblenz, Ann; Corn, Paul; Parikh, Nila U; Starbuck, Michael W; Thompson, Jerry T; Lee, Francis; Logothetis, Christopher J; Darnay, Bryant G

    2009-11-01

    Therapies to target prostate cancer bone metastases have only limited effects. New treatments are focused on the interaction between cancer cells, bone marrow cells and the bone matrix. Osteoclasts play an important role in the development of bone tumors caused by prostate cancer. Since Src kinase has been shown to be necessary for osteoclast function, we hypothesized that dasatinib, a Src family kinase inhibitor, would reduce osteoclast activity and prostate cancer (PC-3) cell-induced osteoclast formation. Dasatinib inhibited RANKL-induced osteoclast differentiation of bone marrow-derived monocytes with an EC(50) of 7.5 nM. PC-3 cells, a human prostate cancer cell line, were able to differentiate RAW 264.7 cells, a murine monocytic cell line, into osteoclasts, and dasatinib inhibited this differentiation. In addition, conditioned medium from PC-3 cell cultures was able to differentiate RAW 264.7 cells into osteoclasts and this too, was inhibited by dasatinib. Even the lowest concentration of dasatinib, 1.25 nmol, inhibited osteoclast differentiation by 29%. Moreover, dasatinib inhibited osteoclast activity by 58% as measured by collagen 1 release. We performed in vitro experiments utilizing the Src family kinase inhibitor dasatinib to target osteoclast activation as a means of inhibiting prostate cancer bone metastases. Dasatinib inhibits osteoclast differentiation of mouse primary bone marrow-derived monocytes and PC-3 cell-induced osteoclast differentiation. Dasatinib also inhibits osteoclast degradation activity. Inhibiting osteoclast differentiation and activity may be an effective targeted therapy in patients with prostate cancer bone metastases.

  9. Shakuyakukanzoto attenuates oxaliplatin-induced cold dysesthesia by inhibiting the expression of transient receptor potential melastatin 8 in mice

    Directory of Open Access Journals (Sweden)

    Tsugunobu Andoh

    2017-01-01

    Full Text Available Oxaliplatin-induced peripheral neuropathy characterized especially as cold dysesthesia is a major dose-limiting side effect of the drug and is very difficult to control. In the present study, we examined whether the traditional herbal formulation Shakuyakukanzoto (SKT: 芍藥甘草湯Sháo Yào Gān Cǎo Tāng could relieve oxaliplatin-induced cold dysesthesia in mice. The inhibitory mechanisms were also investigated. Repetitive administration of SKT (0.1–1.0 g/kg starting from the day after oxaliplatin injection inhibited cold dysesthesia in a dose-dependent manner. Our previous report has shown that the mRNA expression of transient receptor potential melastatin 8 (TRPM8, characterized as a cold-sensing cation channel, is increased in the dorsal root ganglia of mice treated with oxaliplatin. In addition, TRPM8 antagonist TC-I 2014 (10 and 30 mg/kg also attenuated cold dysesthesia in oxaliplatin-treated mice. Taken together, it is suggested that TRPM8 is involved in the cold dysesthesia induced by oxaliplatin. Repetitive administration of SKT inhibited the mRNA expression of TRPM8 induced by oxaliplatin in the dorsal root ganglia. These results suggested that prophylactic repetitive administration of SKT is effective in preventing the exacerbation of oxaliplatin-induced cold dysesthesia by inhibiting the mRNA expression of TRPM8 in the dorsal root ganglia.

  10. Novel Therapeutic Targets to Inhibit Tumor Microenvironment Induced Castration-Resistant Prostate Cancer

    Science.gov (United States)

    2017-12-01

    AWARD NUMBER: W81XWH-13-1-0163 TITLE: Novel Therapeutic Targets to Inhibit Tumor Microenvironment Induced Castration-resistant Prostate Cancer ...Prostate Cancer 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Feng Yang, Ph.D. 5d. PROJECT NUMBER 5e. TASK NUMBER E-Mail: fyang@bcm.edu...W81XWH-13-1-0163 " Novel Therapeutic Targets to Inhibit Tumor Microenvironment Induced Castration-resistant Prostate Cancer " Introduction AR signaling

  11. Antidepressants induce autophagy dependent-NLRP3-inflammasome inhibition in Major depressive disorder.

    Science.gov (United States)

    Alcocer-Gómez, Elísabet; Casas-Barquero, Nieves; Williams, Matthew R; Romero-Guillena, Samuel L; Cañadas-Lozano, Diego; Bullón, Pedro; Sánchez-Alcazar, José Antonio; Navarro-Pando, José M; Cordero, Mario D

    2017-07-01

    Major Depressive Disorder (MDD, ICD-10: F-33) is a prevalent illness in which the pathogenic mechanism remains elusive. Recently an important role has been attributed to neuro-inflammation, and specifically the NLRP3-inflammasome complex, in the pathogenesis of MDD. This suggests a key role for immunomodulation as a key pathway in the treatment of this disorder. This study evaluates the involvement of nine common antidepressants in the NLRP3-inflammasome complex (fluoxetine, paroxetine, mianserin, mirtazapine, venlafaxine, desvenlafaxine, amitriptyline, imipramine and agomelatine), both in in vitro THP-1 cells stimulated by ATP, and in a stress-induced depressive animal or MDD patients. Antidepressant treatment induced inflammasome inhibition was observed by decreased serum levels of IL-1β and IL-18 and decrease of NLRP3 and IL-1β (p17) protein expression. This was also observed under stress-induced depressive behaviour and inflammasome activation in C57Bl/6 mice in vivo. Deletion of key autophagy mediator Atg5 in embryonic fibroblasts (MEF cells) showed an autophagy dependent-NLRP3-inflammasome inhibition by antidepressant treatment. These results suggest the NLRP3-inflammasome could be a biomarker for antidepressant treatment response in MDD patients, and therefore the monitoring of NLRP3 expression levels and/or IL-1β/IL-18 release may have clinical value in drug selection. Existing evidence suggests an anti-inflammatory effect of some antidepressants shown by IL-1β, IL-6 and TNF-α. Our data have shown that antidepressant-mediated autophagy may have a role in restoration of certain metabolic and immunological pathways in MDD patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Acacetin inhibits glutamate release and prevents kainic acid-induced neurotoxicity in rats.

    Directory of Open Access Journals (Sweden)

    Tzu-Yu Lin

    Full Text Available An excessive release of glutamate is considered to be a molecular mechanism associated with several neurological diseases that causes neuronal damage. Therefore, searching for compounds that reduce glutamate neurotoxicity is necessary. In this study, the possibility that the natural flavone acacetin derived from the traditional Chinese medicine Clerodendrum inerme (L. Gaertn is a neuroprotective agent was investigated. The effect of acacetin on endogenous glutamate release in rat hippocampal nerve terminals (synaptosomes was also investigated. The results indicated that acacetin inhibited depolarization-evoked glutamate release and cytosolic free Ca(2+ concentration ([Ca(2+]C in the hippocampal nerve terminals. However, acacetin did not alter synaptosomal membrane potential. Furthermore, the inhibitory effect of acacetin on evoked glutamate release was prevented by the Cav2.2 (N-type and Cav2.1 (P/Q-type channel blocker known as ω-conotoxin MVIIC. In a kainic acid (KA rat model, an animal model used for excitotoxic neurodegeneration experiments, acacetin (10 or 50 mg/kg was administrated intraperitoneally to the rats 30 min before the KA (15 mg/kg intraperitoneal injection, and subsequently induced the attenuation of KA-induced neuronal cell death and microglia activation in the CA3 region of the hippocampus. The present study demonstrates that the natural compound, acacetin, inhibits glutamate release from hippocampal synaptosomes by attenuating voltage-dependent Ca(2+ entry and effectively prevents KA-induced in vivo excitotoxicity. Collectively, these data suggest that acacetin has the therapeutic potential for treating neurological diseases associated with excitotoxicity.

  13. Fisetin inhibits cellular proliferation and induces mitochondria-dependent apoptosis in human gastric cancer cells.

    Science.gov (United States)

    Sabarwal, Akash; Agarwal, Rajesh; Singh, Rana P

    2017-02-01

    The anticancer effects of fisetin, a dietary agent, are largely unknown against human gastric cancer. Herein, we investigated the mechanisms of fisetin-induced inhibition of growth and survival of human gastric carcinoma AGS and SNU-1 cells. Fisetin (25-100 μM) caused significant decrease in the levels of G1 phase cyclins and CDKs, and increased the levels of p53 and its S15 phosphorylation in gastric cancer cells. We also observed that growth suppression and death of non-neoplastic human intestinal FHs74int cells were minimally affected by fisetin. Fisetin strongly increased apoptotic cells and showed mitochondrial membrane depolarization in gastric cancer cells. DNA damage was observed as early as 3 h after fisetin treatment which was accompanied with gamma-H2A.X(S139) phosphorylation and cleavage of PARP. Fisetin-induced apoptosis was observed to be independent of p53. DCFDA and MitoSOX analyses showed an increase in mitochondrial ROS generation in time- and dose-dependent fashion. It also increased cellular nitrite and superoxide generation. Pre-treatment with N-acetyl cysteine (NAC) inhibited ROS generation and also caused protection from fisetin-induced DNA damage. The formation of comets were observed in only fisetin treated cells which was blocked by NAC pre-treatment. Further investigation of the source of ROS, using mitochondrial respiratory chain (MRC) complex inhibitors, suggested that fisetin caused ROS generation specifically through complex I. Collectively, these results for the first time demonstrated that fisetin possesses anticancer potential through ROS production most likely via MRC complex I leading to apoptosis in human gastric carcinoma cells. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. Desipramine inhibits histamine H1 receptor-induced Ca2+ signaling in rat hypothalamic cells.

    Directory of Open Access Journals (Sweden)

    Ji-Ah Kang

    Full Text Available The hypothalamus in the brain is the main center for appetite control and integrates signals from adipose tissue and the gastrointestinal tract. Antidepressants are known to modulate the activities of hypothalamic neurons and affect food intake, but the cellular and molecular mechanisms by which antidepressants modulate hypothalamic function remain unclear. Here we have investigated how hypothalamic neurons respond to treatment with antidepressants, including desipramine and sibutramine. In primary cultured rat hypothalamic cells, desipramine markedly suppressed the elevation of intracellular Ca(2+ evoked by histamine H1 receptor activation. Desipramine also inhibited the histamine-induced Ca(2+ increase and the expression of corticotrophin-releasing hormone in hypothalamic GT1-1 cells. The effect of desipramine was not affected by pretreatment with prazosin or propranolol, excluding catecholamine reuptake activity of desipramine as an underlying mechanism. Sibutramine which is also an antidepressant but decreases food intake, had little effect on the histamine-induced Ca(2+ increase or AMP-activated protein kinase activity. Our results reveal that desipramine and sibutramine have different effects on histamine H1 receptor signaling in hypothalamic cells and suggest that distinct regulation of hypothalamic histamine signaling might underlie the differential regulation of food intake between antidepressants.

  15. The mechanisms of inhibition of the postirradiation recovery in cells

    International Nuclear Information System (INIS)

    Zhestyanikov, V.D.; Semenova, E.G.; Volkova, Z.M.

    1974-01-01

    A study was made of the effect of acriflavine (in a concentration of 5x10 -5 -5x10 -7 M) and caffeine (in a concentration of 1x10 -2 and 1x10 -3 M) on the inclusion of labelled thymidine in nuclei of HeLa Zh-63 cells following UV-irradiation. Caffeine clearly reduces the survival of the irradiated cells and suppresses the irregular DNA synthesis in the cells which is induced by UV-irradiation, in both asynchronous culture and culture synchronized at the G 1 stage, for 7 hours following irradiation. Acriflavine (5x10 -7 M) does not affect the post-irradiation survival rate of the cells and suppresses irregular DNA synthesis in asynchronous culture at all concentrations tested. In contrast with caffeine, acriflavine (5x10 -6 M) suppresses irregular DNA synthesis in culture sychronized at the G 1 stage for only the first 2 hours following irradiation. Acriflavine suppresses replicate DNA synthesis in the irradiated cells, whereas caffeine does not affect this process. (author)

  16. Inhibition of glycogen synthase kinase-3β attenuates glucocorticoid-induced suppression of myogenic differentiation in vitro.

    Directory of Open Access Journals (Sweden)

    Zhenyu Ma

    Full Text Available Glucocorticoids are the only therapy that has been demonstrated to alter the progress of Duchenne muscular dystrophy (DMD, the most common muscular dystrophy in children. However, glucocorticoids disturb skeletal muscle metabolism and hamper myogenesis and muscle regeneration. The mechanisms involved in the glucocorticoid-mediated suppression of myogenic differentiation are not fully understood. Glycogen synthase kinase-3β (GSK-3β is considered to play a central role as a negative regulator in myogenic differentiation. Here, we showed that glucocorticoid treatment during the first 48 h in differentiation medium decreased the level of phosphorylated Ser9-GSK-3β, an inactive form of GSK-3β, suggesting that glucocorticoids affect GSK-3β activity. We then investigated whether GSK-3β inhibition could regulate glucocorticoid-mediated suppression of myogenic differentiation in vitro. Two methods were employed to inhibit GSK-3β: pharmacological inhibition with LiCl and GSK-3β gene knockdown. We found that both methods resulted in enhanced myotube formation and increased levels of muscle regulatory factors and muscle-specific protein expression. Importantly, GSK-3β inhibition attenuated glucocorticoid-induced suppression of myogenic differentiation. Collectively, these data suggest the involvement of GSK-3β in the glucocorticoid-mediated impairment of myogenic differentiation. Therefore, the inhibition of GSK-3β may be a strategy for preventing glucocorticoid-induced muscle degeneration.

  17. Sodium arsenite-induced inhibition of cell proliferation is related to inhibition of IL-2 mRNA expression in mouse activated T cells

    Energy Technology Data Exchange (ETDEWEB)

    Conde, Patricia; Acosta-Saavedra, Leonor C.; Calderon-Aranda, Emma S. [Centro de Investigacion y de Estudios Avanzados, CINVESTAV, Seccion Toxicologia, P.O. Box 14-740, Mexico, D.F. (Mexico); Goytia-Acevedo, Raquel C. [Universidad Juarez del Estado de Durango, Facultad de Medicina, Gomez Palacio, Durango (Mexico)

    2007-04-15

    A proposed mechanism for the As-induced inhibition of cell proliferation is the inhibition of IL-2 secretion. However, the effects of arsenite on IL-2 mRNA expression or on the ERK pathway in activated-T cells have not yet been described. We examined the effect of arsenite on IL-2 mRNA expression, cell activation and proliferation in PHA-stimulated murine lymphocytes. Arsenite (1 and 10 {mu}M) decreased IL-2 mRNA expression, IL-2 secretion and cell proliferation. Arsenite (10 {mu}M) strongly inhibited ERK-phosphorylation. However, the partial inhibition (50%) of IL-2 mRNA produced by 1 {mu}M, consistent with the effects on IL-2 secretion and cell proliferation, could not be explained by the inhibition of ERK-phosphorylation, which was not affected at this concentration. The inhibition of IL-2 mRNA expression caused by 1 {mu}M could be associated to effects on pathways located downstream or parallel to ERK. Arsenite also decreased early activation (surface CD69{sup +} expression) in both CD4{sup +} and CD8{sup +}, and decreased total CD8{sup +} count without significantly affecting CD4{sup +}, supporting that the cellular immune response mediated by cytotoxic T cells is an arsenic target. Thus, our results suggest that arsenite decreases IL-2 mRNA levels and T-cell activation and proliferation. However, further studies on the effects of arsenite on IL-2 gene transcription and IL-2 mRNA stability are needed. (orig.)

  18. Brevenal inhibits pacific ciguatoxin-1B-induced neurosecretion from bovine chromaffin cells.

    Directory of Open Access Journals (Sweden)

    César Mattei

    Full Text Available Ciguatoxins and brevetoxins are neurotoxic cyclic polyether compounds produced by dinoflagellates, which are responsible for ciguatera and neurotoxic shellfish poisoning (NSP respectively. Recently, brevenal, a natural compound was found to specifically inhibit brevetoxin action and to have a beneficial effect in NSP. Considering that brevetoxin and ciguatoxin specifically activate voltage-sensitive Na+ channels through the same binding site, brevenal has therefore a good potential for the treatment of ciguatera. Pacific ciguatoxin-1B (P-CTX-1B activates voltage-sensitive Na+ channels and promotes an increase in neurotransmitter release believed to underpin the symptoms associated with ciguatera. However, the mechanism through which slow Na+ influx promotes neurosecretion is not fully understood. In the present study, we used chromaffin cells as a model to reconstitute the sequence of events culminating in ciguatoxin-evoked neurosecretion. We show that P-CTX-1B induces a tetrodotoxin-sensitive rise in intracellular Na+, closely followed by an increase in cytosolic Ca2+ responsible for promoting SNARE-dependent catecholamine secretion. Our results reveal that brevenal and beta-naphtoyl-brevetoxin prevent P-CTX-1B secretagogue activity without affecting nicotine or barium-induced catecholamine secretion. Brevenal is therefore a potent inhibitor of ciguatoxin-induced neurotoxic effect and a potential treatment for ciguatera.

  19. Brevenal inhibits pacific ciguatoxin-1B-induced neurosecretion from bovine chromaffin cells.

    Science.gov (United States)

    Mattei, César; Wen, Peter J; Nguyen-Huu, Truong D; Alvarez, Martha; Benoit, Evelyne; Bourdelais, Andrea J; Lewis, Richard J; Baden, Daniel G; Molgó, Jordi; Meunier, Frédéric A

    2008-01-01

    Ciguatoxins and brevetoxins are neurotoxic cyclic polyether compounds produced by dinoflagellates, which are responsible for ciguatera and neurotoxic shellfish poisoning (NSP) respectively. Recently, brevenal, a natural compound was found to specifically inhibit brevetoxin action and to have a beneficial effect in NSP. Considering that brevetoxin and ciguatoxin specifically activate voltage-sensitive Na+ channels through the same binding site, brevenal has therefore a good potential for the treatment of ciguatera. Pacific ciguatoxin-1B (P-CTX-1B) activates voltage-sensitive Na+ channels and promotes an increase in neurotransmitter release believed to underpin the symptoms associated with ciguatera. However, the mechanism through which slow Na+ influx promotes neurosecretion is not fully understood. In the present study, we used chromaffin cells as a model to reconstitute the sequence of events culminating in ciguatoxin-evoked neurosecretion. We show that P-CTX-1B induces a tetrodotoxin-sensitive rise in intracellular Na+, closely followed by an increase in cytosolic Ca2+ responsible for promoting SNARE-dependent catecholamine secretion. Our results reveal that brevenal and beta-naphtoyl-brevetoxin prevent P-CTX-1B secretagogue activity without affecting nicotine or barium-induced catecholamine secretion. Brevenal is therefore a potent inhibitor of ciguatoxin-induced neurotoxic effect and a potential treatment for ciguatera.

  20. Essential oil from lemon peels inhibit key enzymes linked to neurodegenerative conditions and pro-oxidant induced lipid peroxidation.

    Science.gov (United States)

    Oboh, Ganiyu; Olasehinde, Tosin A; Ademosun, Ayokunle O

    2014-01-01

    This study sought to investigate the effects of essential oil from lemon (Citrus limoni) peels on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities in vitro. The essential oil was extracted by hydrodistillation, dried with anhydrous Na2SO4 and characterized using gas chromatography. Antioxidant properties of the oil and inhibition of pro-oxidant-induced lipid peroxidation in rats brain homogenate were also assessed. The essential oil inhibited AChE and BChE activities in a concentration-dependent manner. GC analysis revealed the presence of sabinene, limonene, α-pinene, β-pinene, neral, geranial, 1,8-cineole, linalool, borneol, α-terpineol, terpinen-4-ol, linalyl acetate and β-caryophyllene. Furthermore, the essential oil exhibited antioxidant activities as typified by ferric reducing property, Fe(2+)-chelation and radicals [DPPH, ABTS, OH, NO] scavenging abilities. The inhibition of AChE and BChE activities, inhibition of pro-oxidant induced lipid peroxidation and antioxidant activities could be possible mechanisms for the use of the essential oil in the management and prevention of oxidative stress-induced neurodegeneration.

  1. Mechanism of inhibition of mouse Slo3 (KCa 5.1) potassium channels by quinine, quinidine and barium.

    Science.gov (United States)

    Wrighton, David C; Muench, Stephen P; Lippiat, Jonathan D

    2015-09-01

    The Slo3 (KCa 5.1) channel is a major component of mammalian KSper (sperm potassium conductance) channels and inhibition of these channels by quinine and barium alters sperm motility. The aim of this investigation was to determine the mechanism by which these drugs inhibit Slo3 channels. Mouse (m) Slo3 (KCa 5.1) channels or mutant forms were expressed in Xenopus oocytes and currents recorded with 2-electrode voltage-clamp. Gain-of-function mSlo3 mutations were used to explore the state-dependence of the inhibition. The interaction between quinidine and mSlo3 channels was modelled by in silico docking. Several drugs known to block KSper also affected mSlo3 channels with similar levels of inhibition. The inhibition induced by extracellular barium was prevented by increasing the extracellular potassium concentration. R196Q and F304Y mutations in the mSlo3 voltage sensor and pore, respectively, both increased channel activity. The F304Y mutation did not alter the effects of barium, but increased the potency of inhibition by both quinine and quinidine approximately 10-fold; this effect was not observed with the R196Q mutation. Block of mSlo3 channels by quinine, quinidine and barium is not state-dependent. Barium inhibits mSlo3 outside the cell by interacting with the selectivity filter, whereas quinine and quinidine act from the inside, by binding in a hydrophobic pocket formed by the S6 segment of each subunit. Furthermore, we propose that the Slo3 channel activation gate lies deep within the pore between F304 in the S6 segment and the selectivity filter. © 2015 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of The British Pharmacological Society.

  2. Downregulation of β1,4-galactosyltransferase 1 inhibits CDK11p58-mediated apoptosis induced by cycloheximide

    International Nuclear Information System (INIS)

    Li Zejuan; Wang Hanzhou; Zong Hongliang; Sun Qing; Kong Xiangfei; Jiang Jianhai; Gu Jianxin

    2005-01-01

    Cyclin-dependent kinase 11 (CDK11; also named PITSLRE) is part of the large family of p34 cdc2 -related kinases whose functions appear to be linked with cell cycle progression, tumorigenesis, and apoptotic signaling. The mechanism that CDK11 p58 induces apoptosis is not clear. Some evidences suggested β1,4-galactosyltransferase 1 (β1,4-GT 1) might participate in apoptosis induced by CDK11 p58 . In this study, we demonstrated that ectopically expressed β1,4-GT 1 increased CDK11 p58 -mediated apoptosis induced by cycloheximide (CHX). In contrast, RNAi-mediated knockdown of β1,4-GT 1 effectively inhibited apoptosis induced by CHX in CDK11 p58 -overexpressing cells. For example, the cell morphological and nuclear changes were reduced; the loss of cell viability was prevented and the number of cells in sub-G1 phase was decreased. Knock down of β1,4-GT 1 also inhibited the release of cytochrome c from mitochondria and caspase-3 processing. Therefore, the cleavage of CDK11 p58 by caspase-3 was reduced. We proposed that β1,4-GT 1 might contribute to the pro-apoptotic effect of CDK11 p58 . This may represent a new mechanism of β1,4-GT 1 in CHX-induced apoptosis of CDK11 p58 -overexpressing cells

  3. Metalloproteinase Inhibition Protects against Reductions in Circulating Adrenomedullin during Lead-induced Acute Hypertension.

    Science.gov (United States)

    Nascimento, Regina A; Mendes, Gabryella; Possomato-Vieira, Jose S; Gonçalves-Rizzi, Victor Hugo; Kushima, Hélio; Delella, Flavia K; Dias-Junior, Carlos A

    2015-06-01

    Intoxication with lead (Pb) results in increased blood pressure by mechanisms involving matrix metalloproteinases (MMPs). Recent findings have revealed that MMP type two (MMP-2) seems to cleave vasoactive peptides. This study examined whether MMP-2 and MMP-9 levels/activities increase after acute intoxication with low lead concentrations and whether these changes were associated with increases in blood pressure and circulating endothelin-1 or with reductions in circulating adrenomedullin and calcitonin gene-related peptide (CGRP). Here, we expand previous findings and examine whether doxycycline (a MMPs inhibitor) affects these alterations. Wistar rats received intraperitoneally (i.p.) 1st dose 8 μg/100 g of lead (or sodium) acetate, a subsequent dose of 0.1 μg/100 g to cover daily loss and treatment with doxycycline (30 mg/kg/day) or water by gavage for 7 days. Similar whole-blood lead levels (9 μg/dL) were found in lead-exposed rats treated with either doxycycline or water. Lead-induced increases in systolic blood pressure (from 143 ± 2 to 167 ± 3 mmHg) and gelatin zymography of plasma samples showed that lead increased MMP-9 (but not MMP-2) levels. Both lead-induced increased MMP-9 activity and hypertension were blunted by doxycycline. Doxycycline also prevented lead-induced reductions in circulating adrenomedullin. No significant changes in plasma levels of endothelin-1 or CGRP were found. Lead-induced decreases in nitric oxide markers and antioxidant status were not prevented by doxycycline. In conclusion, acute lead exposure increases blood pressure and MMP-9 activity, which were blunted by doxycycline. These findings suggest that MMP-9 may contribute with lead-induced hypertension by cleaving the vasodilatory peptide adrenomedullin, thereby inhibiting adrenomedullin-dependent lowering of blood pressure. © 2014 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  4. Canine tracheal epithelial cells are more sensitive than rat tracheal epithelial cells to transforming growth factor beta induced growth inhibition

    International Nuclear Information System (INIS)

    Hubbs, A.F.; Hahn, F.F.; Kelly, G.; Thomassen, D.G.

    1988-01-01

    Transforming growth factor beta (TGFβ) markedly inhibited growth of canine tracheal epithelial (CTE) cells. Reduced responsiveness to TGFβ-induced growth inhibition accompanied neoplastic progression of these cells from primary to transformed to neoplastic. This was similar to the relationship between neoplastic progression and increased resistance to TGFβ-induced growth inhibition seen for rat tracheal epithelial (RTE) cells. The canine cells were more sensitive than rat cells to TGFβ-induced growth inhibition at all stages in the neoplastic process. (author)

  5. A Neurobehavioral Mechanism Linking Behaviorally Inhibited Temperament and Later Adolescent Social Anxiety.

    Science.gov (United States)

    Buzzell, George A; Troller-Renfree, Sonya V; Barker, Tyson V; Bowman, Lindsay C; Chronis-Tuscano, Andrea; Henderson, Heather A; Kagan, Jerome; Pine, Daniel S; Fox, Nathan A

    2017-12-01

    Behavioral inhibition (BI) is a temperament identified in early childhood that is a risk factor for later social anxiety. However, mechanisms underlying the development of social anxiety remain unclear. To better understand the emergence of social anxiety, longitudinal studies investigating changes at behavioral neural levels are needed. BI was assessed in the laboratory at 2 and 3 years of age (N = 268). Children returned at 12 years, and an electroencephalogram was recorded while children performed a flanker task under 2 conditions: once while believing they were being observed by peers and once while not being observed. This methodology isolated changes in error monitoring (error-related negativity) and behavior (post-error reaction time slowing) as a function of social context. At 12 years, current social anxiety symptoms and lifetime diagnoses of social anxiety were obtained. Childhood BI prospectively predicted social-specific error-related negativity increases and social anxiety symptoms in adolescence; these symptoms directly related to clinical diagnoses. Serial mediation analysis showed that social error-related negativity changes explained relations between BI and social anxiety symptoms (n = 107) and diagnosis (n = 92), but only insofar as social context also led to increased post-error reaction time slowing (a measure of error preoccupation); this model was not significantly related to generalized anxiety. Results extend prior work on socially induced changes in error monitoring and error preoccupation. These measures could index a neurobehavioral mechanism linking BI to adolescent social anxiety symptoms and diagnosis. This mechanism could relate more strongly to social than to generalized anxiety in the peri-adolescent period. Copyright © 2017 American Academy of Child and Adolescent Psychiatry. All rights reserved.

  6. The mechanism of gastrin release in cysteamine-induced duodenal ulcer

    DEFF Research Database (Denmark)

    Poulsen, Steen Seier

    1982-01-01

    a rise in serum gastrin from 29 +/- 5 pg/ml to a maximum of 203 +/- 62 pg/ml after 3 h in unoperated rats, whereas no rise was seen in vagotomized or antrectomized rats. The beta-adrenergic blocking agent propranolol strongly inhibited cysteamine-induced gastrin release, whereas atropine dependent......Duodenal ulcer can be induced in rats by a single dose of cysteamine. The ulcer formation is accompanied by acid hypersecretion and elevated serum gastrin levels. This study was performed to elucidate the mechanisms of gastrin release after an ulcerogenic dose of cysteamine. Cysteamine induced...

  7. Inhibition mechanism of compound ethanol extracts from wuweizi (fructus schisandrae chinensis) on renal interstitial fibrosis in diabetic nephropathy model mice.

    Science.gov (United States)

    Zhang, Yanqiu; Zhang, Daning; Zhang, Mianzhi

    2012-12-01

    To evaluate inhibition effect and mechanism of compound ethanol extracts from Wuweizi (Fructus Schisandrae Chinensis), Chuanxiong (Rhizoma Chuanxiong) and Muli (Cocha Ostreae) (FRC) on glomerular and tubular interstitial fibrosis in streptozocin (STZ)-induced diabetic nephropathy (ND) model mice. Twenty-seven male C57BL/6 mice were divided randomly into 3 groups: nondibetic (ND), STZ-induced diabetic (D), and STZ-induced diabetic that were treated with 5 g x kg(-1) x day(-1) of FRC by oral gavage (D(FRC)), with 9 in each group. The protein expressions of E-cadherin, alpha-smooth muscle actin (alpha-SMA), Plasminogen Activator Inhibitor-1 (PAL-1) in renal tissues were investigated by Western blotting. The expressions of fibronectin (FN) and alpha-SMA were detected by immunohistochemical method. The morphological changes of renal tissues were observed under a microscope. Renal tissues in the D(FRC) group showed a lessened degree of fibrosis. Meanwhile, the expressions of FN, alpha-SMA and PAI-1 were significantly lower in the D(FRC) group than those in the D group (all P < 0.05). FRC can ameliorate the DN in the C57BL/6 mice, and its mechanism may relate to inhibition on the epithelial to mesenchymal transdifferentiation, endothelial-myofibroblast transition and PAL-1 expression.

  8. Technetium-99 conjugated with methylene diphosphonate inhibits receptor activator of nuclear factor-κB ligand-induced osteoclastogenesis.

    Science.gov (United States)

    Gong, Wei; Dou, Huan; Liu, Xianqin; Sun, Lingyun; Hou, Yayi

    2012-10-01

    1. In the present study, we investigated the effects of technetium-99 conjugated with methylene diphosphonate ((99)Tc-MDP), an agent used in radionuclide therapy, on receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis and explored the underlying mechanisms. 2. The murine macrophage cell line RAW264.7 and bone marrow-derived-macrophages from C57BL/6 mice (BMM) were used as models for osteoclastogenesis in vitro. The expression of some key factors in RANKL (50 ng/mL)-induced osteoclastogenesis in RAW264.7 cells was investigated by flow cytometry and real-time reverse transcription-polymerase chain reaction (RT-PCR). To detect multinucleated osteoclast formation, RAW264.7 cells were induced with RANKL for 4 days, whereas BMM were induced by 50 ng/mL RANKL and 20 ng/mL macrophage colony-stimulating factor for 7 days, before being stained with tartrate-resistant acid phosphatase. 3. Osteoclastogenesis was evaluated using the osteoclast markers CD51, matrix metalloproteinase (MMP)-9 and cathepsin K. At 0.01 μg/mL, (99)Tc-MDP significantly inhibited RANKL-induced osteoclastogenesis without any cytotoxicity. In addition, (99)Tc-MDP abolished the appearance of multinucleated osteoclasts. 4. Real-time RT-PCR analysis of transcription factor expression revealed that (99)Tc-MDP inhibited the expression of c-Fos and nuclear factor of activated T cells. In addition, (99)Tc-MDP inhibited the expression of the inflammatory factors interleukin (IL)-6, tumour necrosis factor-α and IL-1β. Finally, (99)Tc-MDP inhibited the activation of mitogen-activated protein kinases in RAW264.7 cells following RANKL stimulation. 5. In conclusion, (99)Tc-MDP possesses anti-osteoclastogenic activity against RANKL-induced osteoclast formation. © 2012 The Authors Clinical and Experimental Pharmacology and Physiology © 2012 Wiley Publishing Asia Pty Ltd.

  9. Endoglin inhibits ERK-induced c-Myc and cyclin D1 expression to impede endothelial cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Christopher C.; Bloodworth, Jeffrey C. [Division of Pharmacology, Columbus, OH 43210 (United States); Mythreye, Karthikeyan [Duke University, Department of Medicine, Durham, NC 27708 (United States); Lee, Nam Y., E-mail: lee.5064@osu.edu [Division of Pharmacology, Columbus, OH 43210 (United States); Davis Heart and Lung Research Institute, Columbus, OH 43210 (United States)

    2012-08-03

    Highlights: Black-Right-Pointing-Pointer Endoglin inhibits ERK activation in endothelial cells. Black-Right-Pointing-Pointer Endoglin is a regulator of c-Myc and cyclin D1 expression. Black-Right-Pointing-Pointer {beta}-arrestin2 interaction with endoglin is required for ERK/c-Myc repression. Black-Right-Pointing-Pointer Endoglin impedes cellular proliferation by targeting ERK-induced mitogenic signaling. -- Abstract: Endoglin is an endothelial-specific transforming growth factor beta (TGF-{beta}) co-receptor essential for angiogenesis and vascular remodeling. Endoglin regulates a wide range of cellular processes, including cell adhesion, migration, and proliferation, through TGF-{beta} signaling to canonical Smad and Smad-independent pathways. Despite its overall pro-angiogenic role in the vasculature, the underlying mechanism of endoglin action is poorly characterized. We previously identified {beta}-arrestin2 as a binding partner that causes endoglin internalization from the plasma membrane and inhibits ERK signaling towards endothelial migration. In the present study, we examined the mechanistic role of endoglin and {beta}-arrestin2 in endothelial cell proliferation. We show that endoglin impedes cell growth through sustained inhibition of ERK-induced c-Myc and cyclin D1 expression in a TGF-{beta}-independent manner. The down-regulation of c-Myc and cyclin D1, along with growth-inhibition, are reversed when the endoglin/{beta}-arrestin2 interaction is disrupted. Given that TGF-{beta}-induced Smad signaling potently represses c-Myc in most cell types, our findings here show a novel mechanism by which endoglin augments growth-inhibition by targeting ERK and key downstream mitogenic substrates.

  10. DNA polymerase gamma inhibition by vitamin K3 induces mitochondria-mediated cytotoxicity in human cancer cells.

    Science.gov (United States)

    Sasaki, Ryohei; Suzuki, Yoko; Yonezawa, Yuko; Ota, Yosuke; Okamoto, Yoshiaki; Demizu, Yusuke; Huang, Peng; Yoshida, Hiromi; Sugimura, Kazuro; Mizushina, Yoshiyuki

    2008-05-01

    Among the vitamin K (VK) compounds, VK3 exhibits distinct cytotoxic activity in cancer cells and is thought to affect redox cycling; however, the underlying mechanisms remain unclear. Here we demonstrate that VK3 selectively inhibits DNA polymerase (pol) gamma, the key enzyme responsible for mitochondrial DNA replication and repair. VK3 at 30 microM inhibited pol gamma by more than 80%, caused impairment of mitochondrial DNA replication and repair, and induced a significant increase in reactive oxygen species (ROS), leading to apoptosis. At a lower concentration (3 microM), VK3 did not cause a significant increase in ROS, but was able to effectively inhibit cell proliferation, which could be reversed by supplementing glycolytic substrates. The cytotoxic action of VK3 was independent of p53 tumor suppressor gene status. Interestingly, VK3 only inhibited pol gamma but did not affect other pol including human pol alpha, pol beta, pol delta, and pol epsilon. VK1 and VK2 exhibited no inhibitory effect on any of the pol tested. These data together suggest that the inhibition of pol gamma by VK3 is relatively specific, and that this compound seems to exert its anticancer activity by two possible mechanisms in a concentration-dependent manner: (1) induction of ROS-mediated cell death at high concentrations; and (2) inhibition of cell proliferation at lower concentrations likely through the suppression of mitochondrial respiratory function. These findings may explain various cytotoxic actions induced by VK3, and may pave the way for the further use of VK3.

  11. Long Non-Coding RNA MEG3 Inhibits Cell Proliferation and Induces Apoptosis in Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Gang Luo

    2015-11-01

    Full Text Available Background/Aims: Long non-coding RNAs (lncRNAs play important roles in diverse biological processes, such as cell growth, apoptosis and migration. Although downregulation of lncRNA maternally expressed gene 3 (MEG3 has been identified in several cancers, little is known about its role in prostate cancer progression. The aim of this study was to detect MEG3 expression in clinical prostate cancer tissues, investigate its biological functions in the development of prostate cancer and the underlying mechanism. Methods: MEG3 expression levels were detected by qRT-PCR in both tumor tissues and adjacent non-tumor tissues from 21 prostate cancer patients. The effects of MEG3 on PC3 and DU145 cells were assessed by MTT assay, colony formation assay, western blot and flow cytometry. Transfected PC3 cells were transplanted into nude mice, and the tumor growth curves were determined. Results: MEG3 decreased significantly in prostate cancer tissues relative to adjacent normal tissues. MEG3 inhibited intrinsic cell survival pathway in vitro and in vivo by reducing the protein expression of Bcl-2, enhancing Bax and activating caspase 3. We further demonstrated that MEG3 inhibited the expression of cell cycle regulatory protein Cyclin D1 and induced cell cycle arrest in G0/G1 phase. Conclusions: Our study presents an important role of MEG3 in the molecular etiology of prostate cancer and implicates the potential application of MEG3 in prostate cancer therapy.

  12. Ellagic acid promotes A{beta}42 fibrillization and inhibits A{beta}42-induced neurotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Ying [Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang 110001 (China); Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China); Yang, Shi-gao; Du, Xue-ting; Zhang, Xi; Sun, Xiao-xia; Zhao, Min [Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China); Sun, Gui-yuan, E-mail: sungy2004@sohu.com [Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang 110001 (China); Liu, Rui-tian, E-mail: rtliu@tsinghua.edu.cn [Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China)

    2009-12-25

    Smaller, soluble oligomers of {beta}-amyloid (A{beta}) play a critical role in the pathogenesis of Alzheimer's disease (AD). Selective inhibition of A{beta} oligomer formation provides an optimum target for AD therapy. Some polyphenols have potent anti-amyloidogenic activities and protect against A{beta} neurotoxicity. Here, we tested the effects of ellagic acid (EA), a polyphenolic compound, on A{beta}42 aggregation and neurotoxicity in vitro. EA promoted A{beta} fibril formation and significant oligomer loss, contrary to previous results that polyphenols inhibited A{beta} aggregation. The results of transmission electron microscopy (TEM) and Western blot displayed more fibrils in A{beta}42 samples co-incubated with EA in earlier phases of aggregation. Consistent with the hypothesis that plaque formation may represent a protective mechanism in which the body sequesters toxic A{beta} aggregates to render them harmless, our MTT results showed that EA could significantly reduce A{beta}42-induced neurotoxicity toward SH-SY5Y cells. Taken together, our results suggest that EA, an active ingredient in many fruits and nuts, may have therapeutic potential in AD.

  13. Evodiamine Induces Apoptosis and Inhibits Migration of HCT-116 Human Colorectal Cancer Cells

    Directory of Open Access Journals (Sweden)

    Lv-Cui Zhao

    2015-11-01

    Full Text Available Evodiamine (EVO exhibits strong anti-cancer effects. However, the effect of EVO on the human colorectal cancer cell line HCT-116 has not been explored in detail, and its underlying molecular mechanisms remain unknown. In the present study, cell viability was assessed by Cell Counting Kit-8 (CCK-8. Cell cycle and apoptosis were measured by flow cytometry, and morphological changes in the nucleus were examined by fluorescence microscopy and Hoechst staining. Cell motility was detected by Transwell assay. ELISA was used to assess the protein levels of autocrine motility factor (AMF in the cell supernatant, and protein expression was determined by Western blotting. Our results showed that EVO inhibited the proliferation of HCT-116 cells, caused accumulation of cells in S and G2/M phases, and reduced the levels of the secreted form of AMF. The protein levels of tumor suppressor protein (p53, Bcl-2 Associated X protein (Bax, B cell CLL/lymphoma-2 (Bcl-2, phosphoglucose isomerase (PGI, phosphorylated signal transducers and activators of transcription 3 (p-STAT3 and matrix metalloproteinase 3 (MMP3 were altered in cells treated with EVO. Taken together, our results suggest that EVO modulates the activity of the p53 signaling pathway to induce apoptosis and downregulate MMP3 expression by inactivating the JAK2/STAT3 pathway through the downregulation of PGI to inhibit migration of HCT-116 human colorectal cancer cells.

  14. Cytotoxicity and Efflux Pump Inhibition Induced by Molybdenum Disulfide and Boron Nitride Nanomaterials with Sheetlike Structure.

    Science.gov (United States)

    Liu, Su; Shen, Zhuoyan; Wu, Bing; Yu, Yue; Hou, Hui; Zhang, Xu-Xiang; Ren, Hong-Qiang

    2017-09-19

    Sheetlike molybdenum disulfide (MoS 2 ) and boron nitride (BN) nanomaterials have attracted attention in the past few years due to their unique material properties. However, information on adverse effects and their underlying mechanisms for sheetlike MoS 2 and BN nanomaterials is rare. In this study, cytotoxicities of sheetlike MoS 2 and BN nanomaterials on human hepatoma HepG2 cells were systematically investigated at different toxic end points. Results showed that MoS 2 and BN nanomaterials decreased cell viability at 30 μg/mL and induced adverse effects on intracellular ROS generation (≥2 μg/mL), mitochondrial depolarization (≥4 μg/mL), and membrane integrity (≥8 μg/mL for MoS 2 and ≥2 μg/mL for BN). Furthermore, this study first found that low exposure concentrations (0.2-2 μg/mL) of MoS 2 and BN nanomaterials could increase plasma membrane fluidity and inhibit transmembrane ATP binding cassette (ABC) efflux transporter activity, which make both nanomaterials act as a chemosensitizer (increasing arsenic toxicity). Damage to plasma membrane and release of soluble Mo or B species might be two reasons that both nanomaterials inhibit efflux pump activities. This study provides a systematic understanding of the cytotoxicity of sheetlike MoS 2 and BN nanomaterials at different exposure levels, which is important for their safe use.

  15. Inhibition of phosphatidylinositol-3-kinase causes increased sensitivity to radiation through a PKB-dependent mechanism

    International Nuclear Information System (INIS)

    Gottschalk, Alexander R.; Doan, Albert; Nakamura, Jean L.; Stokoe, David; Haas-Kogan, Daphne A.

    2005-01-01

    Purpose: To identify whether inhibition of phosphatidylinositol-3-kinase (PI3K) causes increased radiosensitivity through inhibition of protein kinase B (PKB), implicating PKB as an important therapeutic target in prostate cancer. Methods and Materials: The prostate cancer cell line LNCaP was treated with the PI3K inhibitor LY294002, radiation, and combinations of the two therapies. Apoptosis and survival were measured by cell cycle analysis, Western blot analysis for cleaved poly (ADP-ribose) polymerase, and clonogenic survival. To test the hypothesis that inhibition of PKB is responsible for LY294002-induced radiosensitivity, LNCaP cells expressing a constitutively active form of PKB were used. Results: The combination of PI3K inhibition and radiation caused an increase in apoptosis and a decrease in clonogenic survival when compared to either modality alone. The expression of constitutively activated PKB blocked apoptosis induced by combination of PI3K inhibition and radiation and prevented radiosensitization by LY294002. Conclusion: These data indicate that PI3K inhibition increases sensitivity of prostate cancer cell lines to ionizing radiation through inactivation of PKB. Therefore, PTEN mutations, which lead to PKB activation, may play an important role in the resistance of prostate cancer to radiation therapy. Targeted therapy against PKB could be beneficial in the management of prostate cancer patients

  16. Odanacatib Inhibits Resistin-induced Hypertrophic H9c2 Cardiomyoblast Cells Through LKB1/AMPK Pathway

    Directory of Open Access Journals (Sweden)

    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.

  17. Suberoylanilide hydroxamic acid (SAHA) inhibits EGF-induced cell transformation via reduction of cyclin D1 mRNA stability

    International Nuclear Information System (INIS)

    Zhang, Jingjie; Ouyang, Weiming; Li, Jingxia; Zhang, Dongyun; Yu, Yonghui; Wang, York; Li, Xuejun; Huang, Chuanshu

    2012-01-01

    Suberoylanilide hydroxamic acid (SAHA) inhibiting cancer cell growth has been associated with its downregulation of cyclin D1 protein expression at transcription level or translation level. Here, we have demonstrated that SAHA inhibited EGF-induced Cl41 cell transformation via the decrease of cyclin D1 mRNA stability and induction of G0/G1 growth arrest. We found that SAHA treatment resulted in the dramatic inhibition of EGF-induced cell transformation, cyclin D1 protein expression and induction of G0/G1 growth arrest. Further studies showed that SAHA downregulation of cyclin D1 was only observed with endogenous cyclin D1, but not with reconstitutionally expressed cyclin D1 in the same cells, excluding the possibility of SAHA regulating cyclin D1 at level of protein degradation. Moreover, SAHA inhibited EGF-induced cyclin d1 mRNA level, whereas it did not show any inhibitory effect on cyclin D1 promoter-driven luciferase reporter activity under the same experimental conditions, suggesting that SAHA may decrease cyclin D1 mRNA stability. This notion was supported by the results that treatment of cells with SAHA decreased the half-life of cyclin D1 mRNA from 6.95 h to 2.57 h. Consistent with downregulation of cyclin D1 mRNA stability, SAHA treatment also attenuated HuR expression, which has been well-characterized as a positive regulator of cyclin D1 mRNA stability. Thus, our study identifies a novel mechanism responsible for SAHA inhibiting cell transformation via decreasing cyclin D1 mRNA stability and induction of G0/G1 growth arrest in Cl41 cells. -- Highlights: ► SAHA inhibits cell transformation in Cl41 cells. ► SAHA suppresses Cyclin D1 protein expression. ► SAHA decreases cyclin D1 mRNA stability.

  18. Diclofenac inhibits tumor necrosis factor-α-induced nuclear factor-κB activation causing synergistic hepatocyte apoptosis.

    Science.gov (United States)

    Fredriksson, Lisa; Herpers, Bram; Benedetti, Giulia; Matadin, Quraisha; Puigvert, Jordi C; de Bont, Hans; Dragovic, Sanja; Vermeulen, Nico P E; Commandeur, Jan N M; Danen, Erik; de Graauw, Marjo; van de Water, Bob

    2011-06-01

    Drug-induced liver injury (DILI) is an important clinical problem. It involves crosstalk between drug toxicity and the immune system, but the exact mechanism at the cellular hepatocyte level is not well understood. Here we studied the mechanism of crosstalk in hepatocyte apoptosis caused by diclofenac and the proinflammatory cytokine tumor necrosis factor α (TNF-α). HepG2 cells were treated with diclofenac followed by TNF-α challenge and subsequent evaluation of necrosis and apoptosis. Diclofenac caused a mild apoptosis of HepG2 cells, which was strongly potentiated by TNF-α. A focused apoptosis machinery short interference RNA (siRNA) library screen identified that this TNF-α-mediated enhancement involved activation of caspase-3 through a caspase-8/Bid/APAF1 pathway. Diclofenac itself induced sustained activation of c-Jun N-terminal kinase (JNK) and inhibition of JNK decreased both diclofenac and diclofenac/TNF-α-induced apoptosis. Live cell imaging of GFPp65/RelA showed that diclofenac dampened the TNF-α-mediated nuclear factor kappaB (NF-κB) translocation oscillation in association with reduced NF-κB transcriptional activity. This was associated with inhibition by diclofenac of the TNF-α-induced phosphorylation of the inhibitor of NF-κB alpha (IκBα). Finally, inhibition of IκB kinase β (IKKβ) with BMS-345541 as well as stable lentiviral short hairpin RNA (shRNA)-based knockdown of p65/RelA sensitized hepatocytes towards diclofenac/TNF-α-induced cytotoxicity. Together, our data suggest a model whereby diclofenac-mediated stress signaling suppresses TNF-α-induced survival signaling routes and sensitizes cells to apoptosis. Copyright © 2011 American Association for the Study of Liver Diseases.

  19. Global Inhibition of Reactive Oxygen Species (ROS) Inhibits Paclitaxel-Induced Painful Peripheral Neuropathy

    OpenAIRE

    Fidanboylu, Mehmet; Griffiths, Lisa A.; Flatters, Sarah J. L.

    2011-01-01

    Paclitaxel (Taxol (R)) is a widely used chemotherapeutic agent that has a major dose limiting side-effect of painful peripheral neuropathy. Currently there is no effective therapy for the prevention or treatment of chemotherapy-induced painful peripheral neuropathies. Evidence for mitochondrial dysfunction during paclitaxel-induced pain was previously indicated with the presence of swollen and vacuolated neuronal mitochondria. As mitochondria are a major source of reactive oxygen species (ROS...

  20. Different mechanisms are involved in the antibody mediated inhibition of ligand binding to the urokinase receptor

    DEFF Research Database (Denmark)

    List, K; Høyer-Hansen, G; Rønne, E

    1999-01-01

    Certain monoclonal antibodies are capable of inhibiting the biological binding reactions of their target proteins. At the molecular level, this type of effect may be brought about by completely different mechanisms, such as competition for common binding determinants, steric hindrance or interfer......Certain monoclonal antibodies are capable of inhibiting the biological binding reactions of their target proteins. At the molecular level, this type of effect may be brought about by completely different mechanisms, such as competition for common binding determinants, steric hindrance......) can be employed as a highly useful tool to characterize the inhibitory mechanism of specific antagonist antibodies. Two inhibitory antibodies against uPAR, mAb R3 and mAb R5, were shown to exhibit competitive and non-competitive inhibition, respectively, of ligand binding to the receptor. The former...

  1. Andrographolide Induces Autophagic Cell Death and Inhibits Invasion and Metastasis of Human Osteosarcoma Cells in An Autophagy-Dependent Manner

    Directory of Open Access Journals (Sweden)

    Ying Liu

    2017-11-01

    Full Text Available Background/Aims: Osteosarcoma (OS is the most common primary malignant tumor of bone tissue. Although treatment effectiveness has improved, the OS survival rate has fluctuated in recent years. Andrographolide (AG has been reported to have antitumor activity against a variety of tumors. Our aim was to investigate the effects and potential mechanisms of AG in human osteosarcoma. Methods: Cell viability and morphological changes were assessed by MTT and live/dead assays. Apoptosis was detected using Annexin V-FITC/PI double staining, DAPI, and caspase-3 assays. Autophagy was detected with mRFP-GFP-LC3 adenovirus transfection and western blot. Cell migration and invasion were detected by wound healing assay and Transwell® experiments. Results: AG dose-dependently reduced the viability of osteosarcoma cells. No increase in apoptosis was detected in AG-treated human OS MG-63 and U-2OS cells, and the pan-caspase inhibitor z-VAD did not attenuate AG-induced cell death. However, AG induced autophagy by suppressing PI3K/Akt/mTOR and enhancing JNK signaling pathways. 3-MA and Beclin-1 siRNA could reverse the cytotoxic effects of AG. In addition, AG inhibited the invasion and metastasis of OS, and this effect could be reversed with Beclin-1 siRNA. Conclusion: AG inhibits viability and induces autophagic death in OS cells. AG-induced autophagy inhibits the invasion and metastasis of OS.

  2. Aloin Suppresses Lipopolysaccharide-Induced Inflammatory Response and Apoptosis by Inhibiting the Activation of NF-κB

    Directory of Open Access Journals (Sweden)

    Xuan Luo

    2018-02-01

    Full Text Available Numerous herbal-derived natural products are excellent anti-inflammatory agents. Several studies have reported that aloin, the major anthraquinone glycoside obtained from the Aloe species, exhibits anti-inflammatory activity. However, the molecular mechanism of this activity is not well understood. In this report, we found that aloin suppresses lipopolysaccharide-induced pro-inflammatory cytokine secretion and nitric oxide production, and downregulates the expression of tumor necrosis factor alpha (TNF-α, interleukin 6 (IL-6, inducible nitric oxide synthase (iNOS, and cyclooxygenase-2 (COX-2. Aloin inhibits the phosphorylation and acetylation of the NF-κB p65 subunit by suppressing the upstream kinases p38 and Msk1, preventing LPS-induced p65 translocation to the nucleus. We have also shown that aloin inhibits LPS-induced caspase-3 activation and apoptotic cell death. Collectively, these findings suggest that aloin effectively suppresses the inflammatory response, primarily through the inhibition of NF-κB signaling.

  3. Metformin inhibits 7,12-dimethylbenz[a]anthracene-induced breast carcinogenesis and adduct formation in human breast cells by inhibiting the cytochrome P4501A1/aryl hydrocarbon receptor signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Maayah, Zaid H. [Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451 (Saudi Arabia); Ghebeh, Hazem [Stem Cell & Tissue Re-Engineering, King Faisal Specialist Hospital and Research Center, Riyadh 11211 (Saudi Arabia); Alhaider, Abdulqader A. [Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451 (Saudi Arabia); Camel Biomedical Research Unit, College of Pharmacy and Medicine, King Saud University, Riyadh 11451 (Saudi Arabia); El-Kadi, Ayman O.S. [Faculty of Pharmacy & Pharmaceutical Sciences, University of Alberta, Edmonton (Canada); Soshilov, Anatoly A.; Denison, Michael S. [Department of Environmental Toxicology, University of California at Davis, Davis, CA 95616 (United States); Ansari, Mushtaq Ahmad [Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451 (Saudi Arabia); Korashy, Hesham M., E-mail: hkorashy@ksu.edu.sa [Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451 (Saudi Arabia)

    2015-04-15

    Recent studies have established that metformin (MET), an oral anti-diabetic drug, possesses antioxidant activity and is effective against different types of cancer in several carcinogen-induced animal models and cell lines. However, whether MET can protect against breast cancer has not been reported before. Therefore, the overall objectives of the present study are to elucidate the potential chemopreventive effect of MET in non-cancerous human breast MCF10A cells and explore the underlying mechanism involved, specifically the role of cytochrome P4501A1 (CYP1A1)/aryl hydrocarbon receptor (AhR) pathway. Transformation of the MCF10A cells into initiated breast cancer cells with DNA adduct formation was conducted using 7,12-dimethylbenz[a]anthracene (DMBA), an AhR ligand. The chemopreventive effect of MET against DMBA-induced breast carcinogenesis was evidenced by the capability of MET to restore the induction of the mRNA levels of basic excision repair genes, 8-oxoguanine DNA glycosylase (OGG1) and apurinic/apyrimidinic endonuclease1 (APE1), and the level of 8-hydroxy-2-deoxyguanosine (8-OHdG). Interestingly, the inhibition of DMBA-induced DNA adduct formation was associated with proportional decrease in CYP1A1 and in NAD(P)H:quinone oxidoreductase 1 (NQO1) gene expression. Mechanistically, the involvements of AhR and nuclear factor erythroid 2-related factor-2 (Nrf2) in the MET-mediated inhibition of DMBA-induced CYP1A1 and NQO1 gene expression were evidenced by the ability of MET to inhibit DMBA-induced xenobiotic responsive element and antioxidant responsive element luciferase reporter gene expression which suggests an AhR- and Nrf2-dependent transcriptional control. However, the inability of MET to bind to AhR suggests that MET is not an AhR ligand. In conclusion, the present work shows a strong evidence that MET inhibits the DMBA-mediated carcinogenicity and adduct formation by inhibiting the expression of CYP1A1 through an AhR ligand-independent mechanism

  4. Metformin inhibits 7,12-dimethylbenz[a]anthracene-induced breast carcinogenesis and adduct formation in human breast cells by inhibiting the cytochrome P4501A1/aryl hydrocarbon receptor signaling pathway

    International Nuclear Information System (INIS)

    Maayah, Zaid H.; Ghebeh, Hazem; Alhaider, Abdulqader A.; El-Kadi, Ayman O.S.; Soshilov, Anatoly A.; Denison, Michael S.; Ansari, Mushtaq Ahmad; Korashy, Hesham M.

    2015-01-01

    Recent studies have established that metformin (MET), an oral anti-diabetic drug, possesses antioxidant activity and is effective against different types of cancer in several carcinogen-induced animal models and cell lines. However, whether MET can protect against breast cancer has not been reported before. Therefore, the overall objectives of the present study are to elucidate the potential chemopreventive effect of MET in non-cancerous human breast MCF10A cells and explore the underlying mechanism involved, specifically the role of cytochrome P4501A1 (CYP1A1)/aryl hydrocarbon receptor (AhR) pathway. Transformation of the MCF10A cells into initiated breast cancer cells with DNA adduct formation was conducted using 7,12-dimethylbenz[a]anthracene (DMBA), an AhR ligand. The chemopreventive effect of MET against DMBA-induced breast carcinogenesis was evidenced by the capability of MET to restore the induction of the mRNA levels of basic excision repair genes, 8-oxoguanine DNA glycosylase (OGG1) and apurinic/apyrimidinic endonuclease1 (APE1), and the level of 8-hydroxy-2-deoxyguanosine (8-OHdG). Interestingly, the inhibition of DMBA-induced DNA adduct formation was associated with proportional decrease in CYP1A1 and in NAD(P)H:quinone oxidoreductase 1 (NQO1) gene expression. Mechanistically, the involvements of AhR and nuclear factor erythroid 2-related factor-2 (Nrf2) in the MET-mediated inhibition of DMBA-induced CYP1A1 and NQO1 gene expression were evidenced by the ability of MET to inhibit DMBA-induced xenobiotic responsive element and antioxidant responsive element luciferase reporter gene expression which suggests an AhR- and Nrf2-dependent transcriptional control. However, the inability of MET to bind to AhR suggests that MET is not an AhR ligand. In conclusion, the present work shows a strong evidence that MET inhibits the DMBA-mediated carcinogenicity and adduct formation by inhibiting the expression of CYP1A1 through an AhR ligand-independent mechanism

  5. Inhibition of DNA repair by whole body irradiation induced nitric oxide leads to higher radiation sensitivity in lymphocytes

    International Nuclear Information System (INIS)

    Sharma, Deepak; Santosh Kumar, S.; Raghu, Rashmi; Maurya, D.K.; Sainis, K.B.

    2007-01-01

    Full text: It is well accepted that the sensitivity of mammalian cells is better following whole body irradiation (WBI) as compared to that following in vitro irradiation. However, the underlying mechanisms are not well understood. Following WBI, the lipid peroxidation and cell death were significantly higher in lymphocytes as compared to that in vitro irradiated lymphocytes. Further, WBI treatment of tumor bearing mice resulted in a significantly higher inhibition of EL-4 cell proliferation as compared to in vitro irradiation of EL-4 cells. The DNA repair was significantly slower in lymphocytes obtained from WBI treated mice as compared to that in the cells exposed to same dose of radiation in vitro. Generation of nitric oxide following irradiation and also its role in inhibition of DNA repair have been reported, hence, its levels were estimated under both WBI and in vitro irradiation conditions. Nitric oxide levels were significantly elevated in the plasma of WBI treated mice but not in the supernatant of in vitro irradiated cells. Addition of sodium nitroprusside (SNP), a nitric oxide donor to in vitro irradiated cells inhibited the repair of DNA damage and sensitized cells to undergo cell death. It also enhanced the radiation-induced functional impairment of lymphocytes as evinced from suppression of mitogen-induced IL-2, IFN-γ and bcl-2 mRNA expression. Administration of N G -nitro-L-arginine-methyl-ester(L-NAME), a nitric oxide synthase inhibitor, to mice significantly protected lymphocytes against WBI-induced DNA damage and inhibited in vivo radiation-induced production of nitric oxide. Our results indicated that nitric oxide plays a role in the higher radiosensitivity of lymphocytes in vivo by inhibiting repair of DNA damage

  6. Multiple Molecular and Cellular Mechanisms of Action of Lycopene in Cancer Inhibition

    Directory of Open Access Journals (Sweden)

    Cristina Trejo-Solís

    2013-01-01

    Full Text Available Epidemiological studies suggest that including fruits, vegetables, and whole grains in regular dietary intake might prevent and reverse cellular carcinogenesis, reducing the incidence of primary tumours. Bioactive components present in food can simultaneously modulate more than one carcinogenic process, including cancer metabolism, hormonal balance, transcriptional activity, cell-cycle control, apoptosis, inflammation, angiogenesis and metastasis. Some studies have shown an inverse correlation between a diet rich in fruits, vegetables, and carotenoids and a low incidence of different types of cancer. Lycopene, the predominant carotenoid found in tomatoes, exhibits a high antioxidant capacity and has been shown to prevent cancer, as evidenced by clinical trials and studies in cell culture and animal models. In vitro studies have shown that lycopene treatment can selectively arrest cell growth and induce apoptosis in cancer cells without affecting normal cells. In vivo studies have revealed that lycopene treatment inhibits tumour growth in the liver, lung, prostate, breast, and colon. Clinical studies have shown that lycopene protects against prostate cancer. One of the main challenges in cancer prevention is the integration of new molecular findings into clinical practice. Thus, the identification of molecular biomarkers associated with lycopene levels is essential for improving our understanding of the mechanisms underlying its antineoplastic activity.

  7. BMPR2 inhibition induced apoptosis and autophagy via destabilization of XIAP in human chondrosarcoma cells

    Science.gov (United States)

    Jiao, G; Guo, W; Ren, T; Lu, Q; Sun, Y; Liang, W; Ren, C; Yang, K; Sun, K

    2014-01-01

    Bone morphogenetic proteins (BMPs) are multifunctional proteins, and their receptors (BMPRs) have crucial roles in the process of signaling. However, their function in cancer is somewhat inconsistent. It has been demonstrated that more prevalent expression of bone morphogenetic protein receptor 2 (BMPR2) has been detected in dedifferentiated chondrosarcomas than conventional chondrosarcomas. Here, we find that BMPR2 inhibition induces apoptosis and autophagy of chondrosarcoma. We found that BMPR2 expression was correlated with the clinicopathological features of chondrosarcomas, and could predict the treatment outcome. Knockdown of BMPR2 by small interfering RNA results in growth inhibition in chondrosarcoma cells. Silencing BMPR2 promoted G2/M cell cycle arrest, induced chondrosarcoma cell apoptosis through caspase-3-dependent pathway via repression of X-linked inhibitor of apoptosis protein (XIAP) and induced autophagy of chondrosarcoma cells via XIAP-Mdm2-p53 pathway. Inhibition of autophagy induced by BMPR2 small interfering RNA (siBMPR2) sensitized chondrosarcoma cells to siBMPR2-induced apoptotic cell death, suggesting that autophagy has a protective role for chondrosarcoma cells in context of siBMPR2-induced apoptotic cell death. In vivo tumorigenicity assay in mice indicated that inhibition of BMPR2 reduced tumor growth. Taken together, our results suggest that BMPR2 has a significant role in the tumorigenesis of chondrosarcoma, and could be an important prognostic marker for chondrosarcoma. BMPR2 inhibition could eventually provide a promising therapy for chondrosarcoma treatment. PMID:25501832

  8. Methanol Extract of Codonopsis pilosula Inhibits Inducible Nitric ...

    African Journals Online (AJOL)

    Purpose: To evaluate the mechanism of antioxidant activity of the methanol extract of Codonopsis pilosula. Methods: Anti-oxidative properties were assessed by measuring free radical scavenging activity, nitric oxide (NO) levels, protein oxidation and reducing power, while the mechanism of antioxidative effect of ...

  9. Acute ethanol exposure inhibits silencing of cerebellar Golgi cell firing induced by granule cell axon input

    Directory of Open Access Journals (Sweden)

    Paolo eBotta

    2014-02-01

    Full Text Available Golgi cells (GoCs are specialized interneurons that provide inhibitory input to granule cells in the cerebellar cortex. GoCs are pacemaker neurons that spontaneously fire action potentials, triggering spontaneous inhibitory postsynaptic currents in granule cells and also contributing to the generation tonic GABAA receptor-mediated currents in granule cells. In turn, granule cell axons provide feedback glutamatergic input to GoCs. It has been shown that high frequency stimulation of granule cell axons induces a transient pause in GoC firing in a type 2-metabotropic glutamate receptor (mGluR2-dependent manner. Here, we investigated the effect ethanol on the pause of GoC firing induced by high frequency stimulation of granule cell axons. GoC electrophysiological recordings were performed in parasagittal cerebellar vermis slices from postnatal day 23 to 26 rats. Loose-patch cell-attached recordings revealed that ethanol (40 mM reversibly decreases the pause duration. An antagonist of mGluR2 reduced the pause duration but did not affect the effect of ethanol. Whole-cell voltage-clamp recordings showed that currents evoked by an mGluR2 agonist were not significantly affected by ethanol. Perforated-patch experiments in which hyperpolarizing and depolarizing currents were injected into GoCs demonstrated that there is an inverse relationship between spontaneous firing and pause duration. Slight inhibition of the Na+/K+ pump mimicked the effect of ethanol on pause duration. In conclusion, ethanol reduces the granule cell axon-mediated feedback mechanism by reducing the input responsiveness of GoCs. This would result in a transient increase of GABAA receptor-mediated inhibition of granule cells, limiting information flow at the input stage of the cerebellar cortex.

  10. Curcumin Inhibits Apoptosis of Chondrocytes through Activation ERK1/2 Signaling Pathways Induced Autophagy

    Directory of Open Access Journals (Sweden)

    Xiaodong Li

    2017-04-01

    Full Text Available Osteoarthritis (OA is an inflammatory disease of load-bearing synovial joints that is currently treated with drugs that exhibit numerous side effects and are only temporarily effective in treating pain, the main symptom of the disease. Consequently, there is an acute need for novel, safe, and more effective chemotherapeutic agents for the treatment of osteoarthritis and related arthritic diseases. Curcumin, the principal curcuminoid and the most active component in turmeric, is a biologically active phytochemical. Evidence from several recent in vitro studies suggests that curcumin may exert a chondroprotective effect through actions such as anti-inflammatory, anti-oxidative stress, and anti-catabolic activity that are critical for mitigating OA disease pathogenesis and symptoms. In the present study, we investigated the protective mechanisms of curcumin on interleukin 1β (IL-1β-stimulated primary chondrocytes in vitro. The treatment of interleukin (IL-1β significantly reduces the cell viability of chondrocytes in dose and time dependent manners. Co-treatment of curcumin with IL-1β significantly decreased the growth inhibition. We observed that curcumin inhibited IL-1β-induced apoptosis and caspase-3 activation in chondrocytes. Curcumin can increase the expression of phosphorylated extracellular signal-regulated kinases 1/2 (ERK1/2, autophagy marker light chain 3 (LC3-II, and Beclin-1 in chondrocytes. The expression of autophagy markers could be decreased when the chondrocytes were incubated with ERK1/2 inhibitor U0126. Our results suggest that curcumin suppresses apoptosis and inflammatory signaling through its actions on the ERK1/2-induced autophagy in chondrocytes. We propose that curcumin should be explored further for the prophylactic treatment of osteoarthritis in humans and companion animals.

  11. Nickel compounds induce histone ubiquitination by inhibiting histone deubiquitinating enzyme activity

    International Nuclear Information System (INIS)

    Ke Qingdong; Ellen, Thomas P.; Costa, Max

    2008-01-01

    Nickel (Ni) compounds are known carcinogens but underlying mechanisms are not clear. Epigenetic changes are likely to play an important role in nickel ion carcinogenesis. Previous studies have shown epigenetic effects of nickel ions, including the loss of histone acetylation and a pronounced increase in dimethylated H3K9 in nickel-exposed cells. In this study, we demonstrated that both water-soluble and insoluble nickel compounds induce histone ubiquitination (uH2A and uH2B) in a variety of cell lines. Investigations of the mechanism by which nickel increases histone ubiquitination in cells reveal that nickel does not affect cellular levels of the substrates of this modification, i.e., ubiquitin, histones, and other non-histone ubiquitinated proteins. In vitro ubiquitination and deubiquitination assays have been developed to further investigate possible effects of nickel on enzymes responsible for histone ubiquitination. Results from the in vitro assays demonstrate that the presence of nickel did not affect the levels of ubiquitinated histones in the ubiquitinating assay. Instead, the addition of nickel significantly prevents loss of uH2A and uH2B in the deubiquitinating assay, suggesting that nickel-induced histone ubiquitination is the result of inhibition of (a) putative deubiquitinating enzyme(s). Additional supporting evidence comes from the comparison of the response to nickel ions with a known deubiquitinating enzyme inhibitor, iodoacetamide (IAA). This study is the first to demonstrate such effects of nickel ions on histone ubiquitination. It also sheds light on the possible mechanisms involved in altering the steady state of this modification. The study provides further evidence that supports the notion that nickel ions alter epigenetic homeostasis in cells, which may lead to altered programs of gene expression and carcinogenesis

  12. Ghrelin ameliorates acute lung injury induced by oleic acid via inhibition of endoplasmic reticulum stress.

    Science.gov (United States)

    Tian, Xiuli; Liu, Zhijun; Yu, Ting; Yang, Haitao; Feng, Linlin

    2018-03-01

    Acute lung injury (ALI) is associated with excessive mortality and lacks appropriate therapy. Ghrelin is a novel peptide that protects the lung against ALI. This study aimed to investigate whether endoplasmic reticulum stress (ERS) mediates the protective effect of ghrelin on ALI. We used a rat oleic acid (OA)-induced ALI model. Pulmonary impairment was detected by hematoxylin and eosin (HE) staining, lung mechanics, wet/dry weight ratio, and arterial blood gas analysis. Plasma and lung content of ghrelin was examined by ELISA, and mRNA expression was measured by quantitative real-time PCR. Protein levels were detected by western blot. Rats with OA treatment showed significant pulmonary injury, edema, inflammatory cellular infiltration, cytokine release, hypoxia and CO 2 retention as compared with controls. Plasma and pulmonary content of ghrelin was reduced in rats with ALI, and mRNA expression was downregulated. Ghrelin (10nmol/kg) treatment ameliorated the above symptoms, but treatment with the ghrelin antagonists D-Lys 3 GHRP-6 (1μmol/kg) and JMV 2959 (6mg/kg) exacerbated the symptoms. ERS induced by OA was prevented by ghrelin and augmented by ghrelin antagonist treatment. The ERS inducer, tunicamycin (Tm) prevented the ameliorative effect of ghrelin on ALI. The decreased ratio of p-Akt and Akt induced by OA was improved by ghrelin treatment, and was further exacerbated by ghrelin antagonists. Ghrelin protects against ALI by inhibiting ERS. These results provide a new target for prevention and therapy of ALI. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Dipyrone in association with atropine inhibits the effect on gastric emptying induced by hypoglycemia in rats

    Directory of Open Access Journals (Sweden)

    E.F. Collares

    2017-08-01

    Full Text Available Atropine (AT and dipyrone (Dp induce a delay of gastric emptying (GE of liquids in rats by inhibiting muscarinic receptors and activating β2-adrenergic receptors, respectively. The objective of the present study was to determine the effects of pretreatment with AT and Dp, given alone or in combination, on the effect of hypoglycemia in the liquid GE in rats. Male Wistar adult rats (280-310 g were pretreated intravenously with AT, Dp, AT plus Dp or their vehicle and then treated 30 min later with iv insulin or its vehicle (n=8-10 animals/group. Thirty min after treatment, GE was evaluated by determining, in awake rats, the percent gastric retention (%GR of a saline meal labeled with phenol red administered by gavage. The results indicated that insulin induced hypoglycemia in a dose-dependent manner resulting in a significant reduction in %GR of liquid only at the highest dose tested (1 U/kg. Pretreatment with AT significantly increased %GR in the rats treated with 1 U/kg insulin. Surprisingly, after pretreatment with AT, the group treated with the lowest dose of insulin (0.25 U/kg displayed significantly lower %GR compared to its control (vehicle-treated group, which was not seen in the non-pretreated animals. Pretreatment with Dp alone at the dose of 40 mg/kg induced an increase in %GR in both vehicle and 0.25 U/kg-treated rats. A higher dose of Dp alone (80 mg/kg significantly reduced the effect of a marked hypoglycemia induced by 1 U/kg of insulin on GE while in combination with AT the effect was completely abolished. The results with AT suggest that moderate hypoglycemia may render the inhibitory mechanisms of GE ineffective while Dp alone and in combination with AT significantly overcame the effect of hypoglycemia on GE.

  14. Mechanism of inhibition of human secretory phospholipase A2 by flavonoids: rationale for lead design

    Science.gov (United States)

    Lättig, Jens; Böhl, Markus; Fischer, Petra; Tischer, Sandra; Tietböhl, Claudia; Menschikowski, Mario; Gutzeit, Herwig O.; Metz, Peter; Pisabarro, M. Teresa

    2007-08-01

    The human secretory phospholipase A2 group IIA (PLA2-IIA) is a lipolytic enzyme. Its inhibition leads to a decrease in eicosanoids levels and, thereby, to reduced inflammation. Therefore, PLA2-IIA is of high pharmacological interest in treatment of chronic diseases such as asthma and rheumatoid arthritis. Quercetin and naringenin, amongst other flavonoids, are known for their anti-inflammatory activity by modulation of enzymes of the arachidonic acid cascade. However, the mechanism by which flavonoids inhibit Phospholipase A2 (PLA2) remained unclear so far. Flavonoids are widely produced in plant tissues and, thereby, suitable targets for pharmaceutical extractions and chemical syntheses. Our work focuses on understanding the binding modes of flavonoids to PLA2, their inhibition mechanism and the rationale to modify them to obtain potent and specific inhibitors. Our computational and experimental studies focused on a set of 24 compounds including natural flavonoids and naringenin-based derivatives. Experimental results on PLA2-inhibition showed good inhibitory activity for quercetin, kaempferol, and galangin, but relatively poor for naringenin. Several naringenin derivatives were synthesized and tested for affinity and inhibitory activity improvement. 6-(1,1-dimethylallyl)naringenin revealed comparable PLA2 inhibition to quercetin-like compounds. We characterized the binding mode of these compounds and the determinants for their affinity, selectivity, and inhibitory potency. Based on our results, we suggest C(6) as the most promising position of the flavonoid scaffold to introduce chemical modifications to improve affinity, selectivity, and inhibition of PLA2-IIA by flavonoids.

  15. N-cadherin and integrin blockade inhibit arteriolar myogenic reactivity but not pressure-induced increases in intracellular Ca2+

    Directory of Open Access Journals (Sweden)

    Teresa Y. Jackson

    2010-12-01

    Full Text Available The vascular myogenic response is characterized by arterial constriction in response to an increase in intraluminal pressure and dilatation to a decrease in pressure. This mechanism is important for the regulation of blood flow, capillary pressure and arterial pressure. The identity of the mechanosensory mechanism(s for this response is incompletely understood but has been shown to include the integrins as cell-extracellular matrix receptors. The possibility that a cell-cell adhesion receptor is involved has not been studied. Thus, we tested the hypothesis that N-cadherin, a cell-cell adhesion molecule in vascular smooth muscle cells (VSMCs, was important for myogenic responsiveness. The purpose of this study was to investigate:
    1. whether cadherin inhibition blocks myogenic responses to increases in intraluminal pressure and 2. the effect of the cadherin or integrin blockade on pressure-induced changes in [Ca2+]i. Cadherin blockade was tested in isolated rat cremaster arterioles on myogenic responses to acute pressure steps from 60 – 100 mmHg and changes in VSMC Ca2+ were measured using fura-2. In the presence of a synthetic cadherin inhibitory peptide or a function blocking antibody, myogenic responses were inhibited. In contrast, during N-cadherin blockade, pressure-induced changes in [Ca2+]i were not altered. Similarly, vessels treated with function-blocking β1- or β3-integrin antibodies maintained pressure-induced [Ca2+]i responses despite inhibition of myogenic constriction. Collectively, these data suggest that both cadherins and integrins play a fundamental role in mediating myogenic constriction but argue against their direct involvement in mediating pressure-induced [Ca2+]i increases.

  16. The PDE4 inhibitor CHF-6001 and LAMAs inhibit bronchoconstriction-induced remodeling in lung slices

    NARCIS (Netherlands)

    Kistemaker, Loes E M; Oenema, Tjitske A; Baarsma, Hoeke A; Bos, I. Sophie T.; Schmidt, Martina; Facchinetti, Fabrizio; Civelli, Maurizio; Villetti, Gino; Gosens, Reinoud

    2017-01-01

    Combination therapy of PDE4 inhibitors and anticholinergics induces bronchoprotection in COPD. Mechanical forces that arise during bronchoconstriction may contribute to airway remodeling. Therefore, we investigated the impact of PDE4 inhibitors and anticholinergics on bronchoconstriction-induced

  17. Vinpocetine Ameliorates Acetic Acid-Induced Colitis by Inhibiting NF-κB Activation in Mice.

    Science.gov (United States)

    Colombo, Bárbara B; Fattori, Victor; Guazelli, Carla F S; Zaninelli, Tiago H; Carvalho, Thacyana T; Ferraz, Camila R; Bussmann, Allan J C; Ruiz-Miyazawa, Kenji W; Baracat, Marcela M; Casagrande, Rúbia; Verri, Waldiceu A

    2018-04-10

    The idiopathic inflammatory bowel diseases (IBD) comprise two types of chronic intestinal disorders: Crohn's disease and ulcerative colitis. Recruited neutrophils and macrophages contribute to intestinal tissue damage via production of ROS and NF-κB-dependent pro-inflammatory cytokines. The introduction of anti-TNF-α therapies in the treatment of IBD patients was a seminal advance. This therapy is often limited by a loss of efficacy due to the development of adaptive immune response, underscoring the need for novel therapies targeting similar pathways. Vinpocetine is a nootropic drug and in addition to its antioxidant effect, it is known to have anti-inflammatory and analgesic properties, partly by inhibition of NF-κB and downstream cytokines. Therefore, the present study evaluated the effect of the vinpocetine in a model of acid acetic-induced colitis in mice. Treatment with vinpocetine reduced edema, MPO activity, microscopic score and macroscopic damage, and visceral mechanical hyperalgesia. Vinpocetine prevented the reduction of colonic levels of GSH, ABTS radical scavenging ability, and normalized levels of anti-inflammatory cytokine IL-10. Moreover, vinpocetine reduced NF-κB activation and thereby NF-κB-dependent pro-inflammatory cytokines IL-1β, TNF-α, and IL-33 in the colon. Thus, we demonstrate for the first time that vinpocetine has anti-inflammatory, antioxidant, and analgesic effects in a model of acid acetic-induced colitis in mice and deserves further screening to address its suitability as an approach for the treatment of IBD.

  18. Arctigenin preferentially induces tumor cell death under glucose deprivation by inhibiting cellular energy metabolism.

    Science.gov (United States)

    Gu, Yuan; Qi, Chunting; Sun, Xiaoxiao; Ma, Xiuquan; Zhang, Haohao; Hu, Lihong; Yuan, Junying; Yu, Qiang

    2012-08-15

    Selectively eradicating cancer cells with minimum adverse effects on normal cells is a major challenge in the development of anticancer therapy. We hypothesize that nutrient-limiting conditions frequently encountered by cancer cells in poorly vascularized solid tumors might provide an opportunity for developing selective therapy. In this study, we investigated the function and molecular mechanisms of a natural compound, arctigenin, in regulating tumor cell growth. We demonstrated that arctigenin selectively promoted glucose-starved A549 tumor cells to undergo necrosis by inhibiting mitochondrial respiration. In doing so, arctigenin elevated cellular level of reactive oxygen species (ROS) and blocked cellular energy metabolism in the glucose-starved tumor cells. We also demonstrated that cellular ROS generation was caused by intracellular ATP depletion and played an essential role in the arctigenin-induced tumor cell death under the glucose-limiting condition. Furthermore, we combined arctigenin with the glucose analogue 2-deoxyglucose (2DG) and examined their effects on tumor cell growth. Interestingly, this combination displayed preferential cell-death inducing activity against tumor cells compared to normal cells. Hence, we propose that the combination of arctigenin and 2DG may represent a promising new cancer therapy with minimal normal tissue toxicity. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

  19. Allicin protects against cisplatin-induced vestibular dysfunction by inhibiting the apoptotic pathway.

    Science.gov (United States)

    Wu, Xianmin; Cai, Jing; Li, Xiaofei; Li, He; Li, Jianfeng; Bai, Xiaohui; Liu, Wenwen; Han, Yuechen; Xu, Lei; Zhang, Daogong; Wang, Haibo; Fan, Zhaomin

    2017-06-15

    Cisplatin is an anticancer drug that causes the impairment of inner ear function as side effects, including hearing loss and balance dysfunction. The purpose of this study was to investigate the effects of allicin against cisplatin-induced vestibular dysfunction in mice and to make clear the mechanism underlying the protective effects of allicin on oto-vestibulotoxicity. Mice intraperitoneally injected with cisplatin exhibited vestibular dysfunction in swimming test, which agreed with impairment in vestibule. However, these impairments were significantly prevented by pre-treatment with allicin. Allicin markedly reduced cisplatin-activated expression of cleaved-caspase-3 in hair cells and vascular layer cells of utricule, saccule and ampulla, but also decreased AIF nuclear translocation of hair cells in utricule, saccule and ampulla. These results showed that allicin played an effective role in protecting vestibular dysfunction induced by cisplatin via inhibiting caspase-dependent and caspase-independent apoptotic pathways. Therefore, allicin may be useful in preventing oto-vestibulotoxicity mediated by cisplatin. Copyright © 2017. Published by Elsevier B.V.

  20. Midkine inhibits inducible regulatory T cell differentiation by suppressing the development of tolerogenic dendritic cells.

    Science.gov (United States)

    Sonobe, Yoshifumi; Li, Hua; Jin, Shijie; Kishida, Satoshi; Kadomatsu, Kenji; Takeuchi, Hideyuki; Mizuno, Tetsuya; Suzumura, Akio

    2012-03-15

    Midkine (MK), a heparin-binding growth factor, reportedly contributes to inflammatory diseases, including Crohn's disease and rheumatoid arthritis. We previously showed that MK aggravates experimental autoimmune encephalomyelitis (EAE) by decreasing regulatory CD4(+)CD25(+)Foxp3(+) T cells (Tregs), a population that regulates the development of autoimmune responses, although the precise mechanism remains uncertain. In this article, we show that MK produced in inflammatory conditions suppresses the development of tolerogenic dendritic cells (DCregs), which drive the development of inducible Treg. MK suppressed DCreg-mediated expansion of the CD4(+)CD25(+)Foxp3(+) Treg population. DCregs expressed significantly higher levels of CD45RB and produced significantly less IL-12 compared with conventional dendritic cells. However, MK downregulated CD45RB expression and induced IL-12 production by reducing phosphorylated STAT3 levels via src homology region 2 domain-containing phosphatase-2 in DCreg. Inhibiting MK activity with anti-MK RNA aptamers, which bind to the targeted protein to suppress the function of the protein, increased the numbers of CD11c(low)CD45RB(+) dendritic cells and Tregs in the draining lymph nodes and suppressed the severity of EAE, an animal model of multiple sclerosis. Our results also demonstrated that MK was produced by inflammatory cells, in particular, CD4(+) T cells under inflammatory conditions. Taken together, these results suggest that MK aggravates EAE by suppressing DCreg development, thereby impairing the Treg population. Thus, MK is a promising therapeutic target for various autoimmune diseases.

  1. Statin therapy exacerbates alcohol-induced constriction of cerebral arteries via modulation of ethanol-induced BK channel inhibition in vascular smooth muscle.

    Science.gov (United States)

    Simakova, Maria N; Bisen, Shivantika; Dopico, Alex M; Bukiya, Anna N

    2017-12-01

    Statins constitute the most commonly prescribed drugs to decrease cholesterol (CLR). CLR is an important modulator of alcohol-induced cerebral artery constriction (AICAC). Using rats on a high CLR diet (2% CLR) we set to determine whether atorvastatin administration (10mg/kg daily for 18-23weeks) modified AICAC. Middle cerebral arteries were pressurized in vitro at 60mmHg and AICAC was evoked by 50mM ethanol, that is within the range of blood alcohol detected in humans following moderate-to-heavy drinking. AICAC was evident in high CLR+atorvastatin group but not in high CLR diet+placebo. Statin exacerbation of AICAC persisted in de-endothelialized arteries, and was blunted by CLR enrichment in vitro. Fluorescence imaging of filipin-stained arteries showed that atorvastatin decreased vascular smooth muscle (VSM) CLR when compared to placebo, this difference being reduced by CLR enrichment in vitro. Voltage- and calcium-gated potassium channels of large conductance (BK) are known VSM targets of ethanol, with their beta1 subunit being necessary for ethanol-induced channel inhibition and resulting AICAC. Ethanol-induced BK inhibition in excised membrane patches from freshly isolated myocytes was exacerbated in the high CLR diet+atorvastatin group when compared to high CLR diet+placebo. Unexpectedly, atorvastatin decreased the amount and function of BK beta1 subunit as documented by immunofluorescence imaging and functional patch-clamp studies. Atorvastatin exacerbation of ethanol-induced BK inhibition disappeared upon artery CLR enrichment in vitro. Our study demonstrates for the first time statin's ability to exacerbate the vascular effect of a widely consumed drug of abuse, this exacerbation being driven by statin modulation of ethanol-induced BK channel inhibition in the VSM via CLR-mediated mechanism. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Emodin inhibits proliferation and invasion, and induces apoptosis in ...

    African Journals Online (AJOL)

    induced the expression of Bax and caspase-3, when compared with control groups. Conclusion: These ... cancer and colorectal cancer, in which multiple genes and signaling pathways are involved [7-. 10]. However, not much is known about the effect of emodin on the growth of esophageal cancer cells. In the present study ...

  3. Prion protein inhibits microtubule assembly by inducing tubulin oligomerization

    International Nuclear Information System (INIS)

    Nieznanski, Krzysztof; Podlubnaya, Zoya A.; Nieznanska, Hanna

    2006-01-01

    A growing body of evidence points to an association of prion protein (PrP) with microtubular cytoskeleton. Recently, direct binding of PrP to tubulin has also been found. In this work, using standard light scattering measurements, sedimentation experiments, and electron microscopy, we show for First time the effect of a direct interaction between these proteins on tubulin polymerization. We demonstrate that full-length recombinant PrP induces a rapid increase in the turbidity of tubulin diluted below the critical concentration for microtubule assembly. This effect requires magnesium ions and is weakened by NaCl. Moreover, the PrP-induced light scattering structures of tubulin are cold-stable. In preparations of diluted tubulin incubated with PrP, electron microscopy revealed the presence of ∼50 nm disc-shaped structures not reported so far. These unique tubulin oligomers may form large aggregates. The effect of PrP is more pronounced under the conditions promoting microtubule formation. In these tubulin samples, PrP induces formation of the above oligomers associated with short protofilaments and sheets of protofilaments into aggregates. Noticeably, this is accompanied by a significant reduction of the number and length of microtubules. Hence, we postulate that prion protein may act as an inhibitor of microtubule assembly by inducing formation of stable tubulin oligomers

  4. Phenylbutyrate inhibits homologous recombination induced by camptothecin and methyl methanesulfonate

    DEFF Research Database (Denmark)

    Kaiser, Gitte Schalck; Germann, Susanne Manuela; Westergaard, Tine

    2011-01-01

    (CPT) and the alkylating agent methyl methanesulfonate (MMS) is blocked by sodium phenylbutyrate (PBA) in the budding yeast Saccharomyces cerevisiae. In particular, PBA suppresses CPT- and MMS-induced genetic recombination as well as DNA double-strand break repair during mating-type interconversion...

  5. Chloroquinone Inhibits Cell Proliferation and Induces Apoptosis in ...

    African Journals Online (AJOL)

    Purpose: To demonstrate the role of chloroquinone (CQ) in inducing apoptosis in HONE-1 and HNE-1, nasopharyngeal carcinoma (NPC) cell lines. Methods: Water-soluble tetrazolium salt (WST)-1 assay was used for the determination of cell proliferation while an inverted microscope was employed for the analysis of ...

  6. Intermedin inhibits norepinephrine-induced contraction of rat seminal vesicle

    Directory of Open Access Journals (Sweden)

    P.F. Wong

    2014-09-01

    Conclusion: The results demonstrated that the inhibitory action of IMD on NE-induced seminal vesicle contraction was mediated via the ADM receptor(s and the nitric oxide production pathway, partially by the IMD receptor, but not by the CGRP receptor and the cAMP-PKA pathway.

  7. Selective macrophage inhibition abolishes warfarin-induced reduction of metastasis

    NARCIS (Netherlands)

    Maat, B.

    1980-01-01

    Warfarin administered to tumor-bearing mice reduces the number of spontaneous lung metastases. Both macrophage inhibitors silica and carrageenan abolish the warfarin-induced decrease in tumour metastasis, which strongly supports the concept that the antitumour effect of coumarin derivatives is

  8. Eleutheroside E inhibits doxorubicin-induced inflammation and ...

    African Journals Online (AJOL)

    Results: Compared with control group, cell viability was notably elevated after treatment with 50-100. μM EE for 48 ... DOX induced higher rates of cell apoptosis in H9c2 cells (29.5 ± 3.56 %) ..... No conflict of interest associated with this work.

  9. Iptakalim inhibits PDGF-BB-induced human airway smooth muscle cells proliferation and migration

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wenrui; Kong, Hui; Zeng, Xiaoning; Wang, Jingjing; Wang, Zailiang; Yan, Xiaopei; Wang, Yanli; Xie, Weiping, E-mail: wpxie@njmu.edu.cn; Wang, Hong, E-mail: hongwang@njmu.edu.cn

    2015-08-15

    Chronic airway diseases are characterized by airway remodeling which is attributed partly to the proliferation and migration of airway smooth muscle cells (ASMCs). ATP-sensitive potassium (K{sub ATP}) channels have been identified in ASMCs. Mount evidence has suggested that K{sub ATP} channel openers can reduce airway hyperresponsiveness and alleviate airway remodeling. Opening K{sup +} channels triggers K{sup +} efflux, which leading to membrane hyperpolarization, preventing Ca{sup 2+}entry through closing voltage-operated Ca{sup 2+} channels. Intracellular Ca{sup 2+} is the most important regulator of muscle contraction, cell proliferation and migration. K{sup +} efflux decreases Ca{sup 2+} influx, which consequently influences ASMCs proliferation and migration. As a K{sub ATP} channel opener, iptakalim (Ipt) has been reported to restrain the proliferation of pulmonary arterial smooth muscle cells (PASMCs) involved in vascular remodeling, while little is known about its impact on ASMCs. The present study was designed to investigate the effects of Ipt on human ASMCs and the mechanisms underlying. Results obtained from cell counting kit-8 (CCK-8), flow cytometry and 5-ethynyl-2′-deoxyuridine (EdU) incorporation showed that Ipt significantly inhibited platelet-derived growth factor (PDGF)-BB-induced ASMCs proliferation. ASMCs migration induced by PDGF-BB was also suppressed by Ipt in transwell migration and scratch assay. Besides, the phosphorylation of Ca{sup 2+}/calmodulin-dependent kinase II (CaMKII), extracellular regulated protein kinases 1/2 (ERK1/2), protein kinase B (Akt), and cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) were as well alleviated by Ipt administration. Furthermore, we found that the inhibition of Ipt on the PDGF-BB-induced proliferation and migration in human ASMCs was blocked by glibenclamide (Gli), a selective K{sub ATP} channel antagonist. These findings provide a strong evidence to support that Ipt

  10. Silibinin inhibits fibronectin induced motility, invasiveness and survival in human prostate carcinoma PC3 cells via targeting integrin signaling

    Energy Technology Data Exchange (ETDEWEB)

    Deep, Gagan [Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO (United States); University of Colorado Cancer Center, University of Colorado Denver, Aurora, CO (United States); Kumar, Rahul; Jain, Anil K. [Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO (United States); Agarwal, Chapla [Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO (United States); University of Colorado Cancer Center, University of Colorado Denver, Aurora, CO (United States); Agarwal, Rajesh, E-mail: Rajesh.agarwal@ucdenver.edu [Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO (United States); University of Colorado Cancer Center, University of Colorado Denver, Aurora, CO (United States)

    2014-10-15

    Highlights: • Silibinin inhibits fibronectin-induce motile morphology in PC3 cells. • Silibinin inhibits fibronectin-induced migration and invasion in PC3 cells. • Silibinin targets fibronectin-induced integrins and downstream signaling molecule. - Abstract: Prostate cancer (PCA) is the 2nd leading cause of cancer-related deaths among men in the United States. Preventing or inhibiting metastasis-related events through non-toxic agents could be a useful approach for lowering high mortality among PCA patients. We have earlier reported that natural flavonoid silibinin possesses strong anti-metastatic efficacy against PCA however, mechanism/s of its action still remains largely unknown. One of the major events during metastasis is the replacement of cell–cell interaction with integrins-based cell–matrix interaction that controls motility, invasiveness and survival of cancer cells. Accordingly, here we examined silibinin effect on advanced human PCA PC3 cells’ interaction with extracellular matrix component fibronectin. Silibinin (50–200 μM) treatment significantly decreased the fibronectin (5 μg/ml)-induced motile morphology via targeting actin cytoskeleton organization in PC3 cells. Silibinin also decreased the fibronectin-induced cell proliferation and motility but significantly increased cell death in PC3 cells. Silibinin also inhibited the PC3 cells invasiveness in Transwell invasion assays with fibronectin or cancer associated fibroblasts (CAFs) serving as chemoattractant. Importantly, PC3-luc cells cultured on fibronectin showed rapid dissemination and localized in lungs following tail vein injection in athymic male nude mice; however, in silibinin-treated PC3-luc cells, dissemination and lung localization was largely compromised. Molecular analyses revealed that silibinin treatment modulated the fibronectin-induced expression of integrins (α5, αV, β1 and β3), actin-remodeling (FAK, Src, GTPases, ARP2 and cortactin), apoptosis (cPARP and

  11. Silibinin inhibits fibronectin induced motility, invasiveness and survival in human prostate carcinoma PC3 cells via targeting integrin signaling

    International Nuclear Information System (INIS)

    Deep, Gagan; Kumar, Rahul; Jain, Anil K.; Agarwal, Chapla; Agarwal, Rajesh

    2014-01-01

    Highlights: • Silibinin inhibits fibronectin-induce motile morphology in PC3 cells. • Silibinin inhibits fibronectin-induced migration and invasion in PC3 cells. • Silibinin targets fibronectin-induced integrins and downstream signaling molecule. - Abstract: Prostate cancer (PCA) is the 2nd leading cause of cancer-related deaths among men in the United States. Preventing or inhibiting metastasis-related events through non-toxic agents could be a useful approach for lowering high mortality among PCA patients. We have earlier reported that natural flavonoid silibinin possesses strong anti-metastatic efficacy against PCA however, mechanism/s of its action still remains largely unknown. One of the major events during metastasis is the replacement of cell–cell interaction with integrins-based cell–matrix interaction that controls motility, invasiveness and survival of cancer cells. Accordingly, here we examined silibinin effect on advanced human PCA PC3 cells’ interaction with extracellular matrix component fibronectin. Silibinin (50–200 μM) treatment significantly decreased the fibronectin (5 μg/ml)-induced motile morphology via targeting actin cytoskeleton organization in PC3 cells. Silibinin also decreased the fibronectin-induced cell proliferation and motility but significantly increased cell death in PC3 cells. Silibinin also inhibited the PC3 cells invasiveness in Transwell invasion assays with fibronectin or cancer associated fibroblasts (CAFs) serving as chemoattractant. Importantly, PC3-luc cells cultured on fibronectin showed rapid dissemination and localized in lungs following tail vein injection in athymic male nude mice; however, in silibinin-treated PC3-luc cells, dissemination and lung localization was largely compromised. Molecular analyses revealed that silibinin treatment modulated the fibronectin-induced expression of integrins (α5, αV, β1 and β3), actin-remodeling (FAK, Src, GTPases, ARP2 and cortactin), apoptosis (cPARP and

  12. Calcitonin causes a sustained inhibition of protein kinase C-stimulated bone resorption in contrast to the transient inhibition of parathyroid hormone-induced bone resorption

    International Nuclear Information System (INIS)

    Ransjoe, M.; Lerner, U.H.

    1990-01-01

    Calcitonin is a well known inhibitor of osteoclastic bone resortion, both in vivo and in vitro. However, it is also known that calcitonin has only a transient inhibitory effect on bone resorption. The mechanism for this so-called ''escape from inhibition'' phenomenon is not clear. In the present study, the inhibitory effect of calcitonin on phorbol ester-induced bone resorption was examined in cultured neonatal mouse calvaria. Bone resorption was assessed as the release of radioactivity from bones prelabelled in vivo with 45 Ca. Two proteon kinase C-activating phorbol esters, phorbol-12-myristate-13-acetate and phorbol-12,13-dibutyrate, both stimulated 45 Ca release in 120-h cultures at a concentration of 10 nmul/l. Calcitonin (30 nmol/l) inhibited phorbol esterstimulated bone resorption without any ''escape from inhibition''. This was in contrast to the transient inhibitory effect of calcitonin on bone resorption stimulated by parathyroid hormone (10 nmol/l), prostaglandin E 2 (2 μmol/l), and bradykinin (1 μmol/l). Our results suggest that activation of protein kinase C produces a sustained inhibitory effect of calcitonin on bone resorption. (author)

  13. Diospyros kaki Extract Inhibits Alkali Burn-Induced Corneal Neovascularization.

    Science.gov (United States)

    Yang, Sung Jae; Jo, Hyoung; Kim, Kyung-A; Ahn, Hong Ryul; Kang, Suk Woo; Jung, Sang Hoon

    2016-01-01

    The purpose of this study was to evaluate the effect of ethanol extract of Diospyros kaki (EEDK) leaves on corneal neovascularization (CoNV) in rats. One week after the alkali burns in the corneas, the CoNV area coverage in the CoNV-positive control group, 100 mg/kg EEDK group, and 200 mg/kg EEDK group was 43.3% ± 5.5%, 337.7% ± 2.5%, and 27.2% ± 4.3%, respectively. The areas of CoNV in the EEDK-treated groups were significantly different from those of the CoNV group. EEDK significantly attenuated the upregulation of vascular endothelial growth factor, fibroblast growth factor, interleukin-6, and matrix metalloproteinase-2 (MMP-2) protein levels. Orally administrated D. kaki inhibited CoNV development in rats.

  14. Fasitibant chloride, a kinin B2 receptor antagonist, and dexamethasone interact to inhibit carrageenan-induced inflammatory arthritis in rats

    Science.gov (United States)

    Valenti, Claudio; Giuliani, Sandro; Cialdai, Cecilia; Tramontana, Manuela; Maggi, Carlo Alberto

    2012-01-01

    BACKGROUND AND PURPOSE Bradykinin, through the kinin B2 receptor, is involved in inflammatory processes related to arthropathies. B2 receptor antagonists inhibited carrageenan-induced arthritis in rats in synergy with anti-inflammatory steroids. The mechanism(s) underlying this drug interaction was investigated. EXPERIMENTAL APPROACH Drugs inhibiting inflammatory mediators released by carrageenan were injected, alone or in combination, into the knee joint of pentobarbital anaesthetized rats 30 min before intra-articular administration of carrageenan. Their effects on the carrageenan-induced inflammatory responses (joint pain, oedema and neutrophil recruitment) and release of inflammatory mediators (prostaglandins, IL-1β, IL-6 and the chemokine GRO/CINC-1), were assessed after 6 h. KEY RESULTS The combination of fasitibant chloride (MEN16132) and dexamethasone was more effective than each drug administered alone in inhibiting knee joint inflammation and release of inflammatory mediators. Fasitibant chloride, MK571, atenolol, des-Arg9-[Leu8]-bradykinin (B2 receptor, leukotriene, catecholamine and B1 receptor antagonists, respectively) and dexketoprofen (COX inhibitor), reduced joint pain and, except for the latter, also diminished joint oedema. A combination of drugs inhibiting joint pain (fasitibant chloride, des-Arg9-[Leu8]-bradykinin, dexketoprofen, MK571 and atenolol) and oedema (fasitibant chloride, des-Arg9-[Leu8]-bradykinin, MK571 and atenolol) abolished the respective inflammatory response, producing inhibition comparable with that achieved with the combination of fasitibant chloride and dexamethasone. MK571 alone was able to block neutrophil recruitment. CONCLUSIONS AND IMPLICATIONS Bradykinin-mediated inflammatory responses to intra-articular carrageenan were not controlled by steroids, which were not capable of preventing bradykinin effects either by direct activation of the B2 receptor, or through the indirect effects mediated by release of eicosanoids

  15. Acetaldehyde Induces Cytotoxicity of SH-SY5Y Cells via Inhibition of Akt Activation and Induction of Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Tingting Yan

    2016-01-01

    Full Text Available Excessive alcohol consumption can lead to brain tissue damage and cognitive dysfunction. It has been shown that heavy drinking is associated with an earlier onset of neurodegenerative diseases such as Alzheimer’s disease. Acetaldehyde, the most toxic metabolite of ethanol, is speculated to mediate the brain tissue damage and cognitive dysfunction induced by the chronic excessive consumption of alcohol. However, the exact mechanisms by which acetaldehyde induces neurotoxicity are not totally understood. In this study, we investigated the cytotoxic effects of acetaldehyde in SH-SY5Y cells and found that acetaldehyde induced apoptosis of SH-SY5Y cells by downregulating the expression of antiapoptotic Bcl-2 and Bcl-xL and upregulating the expression of proapoptotic Bax. Acetaldehyde treatment led to a significant decrease in the levels of activated Akt and cyclic AMP-responsive element binding protein (CREB. In addition, acetaldehyde induced the activation of p38 mitogen-activated protein kinase (MAPK while inhibiting the activation of extracellular signal-regulated kinases (ERKs, p44/p42MAPK. Meanwhile, acetaldehyde treatment caused an increase in the production of reactive oxygen species and elevated the oxidative stress in SH-SY5Y cells. Therefore, acetaldehyde induces cytotoxicity of SH-SY5Y cells via promotion of apoptotic signaling, inhibition of cell survival pathway, and induction of oxidative stress.

  16. MECHANICAL VIBRATION INHIBITS OSTEOCLAST FORMATION BY REDUCING DC-STAMP RECEPTOR EXPRESSION IN OSTEOCLAST PRECURSOR CELLS

    OpenAIRE

    Kulkarni, R.N.; Voglewede, P.A.; Liu, D.

    2013-01-01

    It is well known that physical inactivity leads to loss of muscle mass, but it also causes bone loss. Mechanistically, osteoclastogenesis and bone resorption have recently been shown to be regulated by vibration. However, the underlying mechanism behind the inhibition of osteoclast formation is yet unknown. Therefore, we investigated whether mechanical vibration of osteoclast precursor cells affects osteoclast formation by the involvement of fusion-related molecules such as dendritic cell-spe...

  17. Mechanism of product inhibition for cellobiohydrolase Cel7A during hydrolysis of insoluble cellulose

    DEFF Research Database (Denmark)

    Olsen, Johan P.; Alasepp, Kadri; Kari, Jeppe

    2016-01-01

    The cellobiohydrolase cellulase Cel7A is extensively utilized in industrial treatment of lignocellulosic biomass under conditions of high product concentrations, and better understanding of inhibition mechanisms appears central in attempts to improve the efficiency of this process. We have...... the lines of conventional enzyme kinetic theory. We found that the product cellobiose lowered the maximal rate without affecting the Michaelis constant, and this kinetic pattern could be rationalized by two fundamentally distinct molecular mechanisms. One was simple reversibility, that is, an increasing...

  18. Epigenetic Regulatory Mechanisms Induced by Resveratrol

    Directory of Open Access Journals (Sweden)

    Guilherme Felipe Santos Fernandes

    2017-11-01

    Full Text Available Resveratrol (RVT is one of the main natural compounds studied worldwide due to its potential therapeutic use in the treatment of many diseases, including cancer, diabetes, cardiovascular diseases, neurodegenerative diseases and metabolic disorders. Nevertheless, the mechanism of action of RVT in all of these conditions is not completely understood, as it can modify not only biochemical pathways but also epigenetic mechanisms. In this paper, we analyze the biological activities exhibited by RVT with a focus on the epigenetic mechanisms, especially those related to DNA methyltransferase (DNMT, histone deacetylase (HDAC and lysine-specific demethylase-1 (LSD1.

  19. A preliminary study on action mechanisms of surviving expression in cell apoptosis induced by high-LET radiation

    International Nuclear Information System (INIS)

    Jin Xiaodong; Li Qiang; Gong Li; Wu Qingfeng; Li Ping; Dai Zhongying; Liu Xinguo; Tao Jiajun

    2010-01-01

    It has been proven that over-expression of surviving in cancerous cell lines is related to the radioresistance of cells to high-LET radiation in previous work. In this study, action mechanisms of surviving gene in apoptosis induced by high-LET radiation were investigated. We found that inhibiting surviving by siRNA had no notable influence on Bcl-2 and Bax expressions induced by carbon ions. Surviving depressed cell apoptosis through the inhibition of the activities of caspase-3 and -9 possibly in cell apoptosis induced by high-LET radiation. (authors)

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

    Science.gov (United States)

    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.

  1. Caffeine inhibits homology-directed repair of I-SceI-induced DNA double-strand breaks.

    Science.gov (United States)

    Wang, Huichen; Boecker, Wilfried; Wang, Hongyan; Wang, Xiang; Guan, Jun; Thompson, Larry H; Nickoloff, Jac A; Iliakis, George

    2004-01-22

    We recently reported that two Chinese hamster mutants deficient in the RAD51 paralogs XRCC2 and XRCC3 show reduced radiosensitization after treatment with caffeine, thus implicating homology-directed repair (HDR) of DNA double-strand breaks (DSBs) in the mechanism of caffeine radiosensitization. Here, we investigate directly the effect of caffeine on HDR initiated by DSBs induced by a rare cutting endonuclease (I-SceI) into one of two direct DNA repeats. The results demonstrate a strong inhibition by caffeine of HDR in wild-type cells, and a substantial reduction of this effect in HDR-deficient XRCC3 mutant cells. Inhibition of HDR and cell radiosensitization to killing shows similar dependence on caffeine concentration suggesting a cause-effect relationship between these effects. UCN-01, a kinase inhibitor that effectively abrogates checkpoint activation in irradiated cells, has only a small effect on HDR, indicating that similar to radiosensitization, inhibition of checkpoint signaling is not sufficient for HDR inhibition. Recombination events occurring during treatment with caffeine are characterized by rearrangements reminiscent to those previously reported for the XRCC3 mutant, and immunofluorescence microscopy demonstrates significantly reduced formation of IR-specific RAD51 foci after caffeine treatment. In summary, our results identify inhibition of HDR as a significant contributor to caffeine radiosensitization.

  2. Osthol attenuates neutrophilic oxidative stress and hemorrhagic shock-induced lung injury via inhibition of phosphodiesterase 4.

    Science.gov (United States)

    Tsai, Yung-Fong; Yu, Huang-Ping; Chung, Pei-Jen; Leu, Yann-Lii; Kuo, Liang-Mou; Chen, Chun-Yu; Hwang, Tsong-Long

    2015-12-01

    Oxidative stress caused by neutrophils is an important pathogenic factor in trauma/hemorrhagic (T/H)-induced acute lung injury (ALI). Osthol, a natural coumarin found in traditional medicinal plants, has therapeutic potential in various diseases. However, the pharmacological effects of osthol in human neutrophils and its molecular mechanism of action remain elusive. In this study, our data showed that osthol potently inhibited the production of superoxide anion (O2(•-)) and reactive oxidants derived therefrom as well as expression of CD11b in N-formylmethionylleucylphenylalanine (FMLP)-activated human neutrophils. However, osthol inhibited neutrophil degranulation only slightly and it failed to inhibit the activity of subcellular NADPH oxidase. FMLP-induced phosphorylation of extracellular signal-regulated kinase (ERK) and protein kinase B (Akt) was inhibited by osthol. Notably, osthol increased the cAMP concentration and protein kinase A (PKA) activity in activated neutrophils. PKA inhibitors reversed the inhibitory effects of osthol, suggesting that these are mediated through cAMP/PKA-dependent inhibition of ERK and Akt activation. Furthermore, the activity of cAMP-specific phosphodiesterase (PDE) 4, but not PDE3 or PDE7, was significantly reduced by osthol. In addition, osthol reduced myeloperoxidase activity and pulmonary edema in rats subjected to T/H shock. In conclusion, our data suggest that osthol has effective anti-inflammatory activity in human neutrophils through the suppression of PDE4 and protects significantly against T/H shock-induced ALI in rats. Osthol may have potential for future clinical application as a novel adjunct therapy to treat lung inflammation caused by adverse circulatory conditions. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Dasatinib inhibits both osteoclast activation and prostate cancer PC-3 cell-induced osteoclast formation

    Science.gov (United States)

    Araujo, John C.; Poblenz, Ann; Corn, Paul G.; Parikh, Nila U.; Starbuck, Michael W.; Thompson, Jerry T.; Lee, Francis; Logothetis, Christopher J.; Darnay, Bryant G.

    2013-01-01

    Purpose Therapies to target prostate cancer bone metastases have only limited effects. New treatments are focused on the interaction between cancer cells, bone marrow cells and the bone matrix. Osteoclasts play an important role in the development of bone tumors caused by prostate cancer. Since Src kinase has been shown to be necessary for osteoclast function, we hypothesized that dasatinib, a Src family kinase inhibitor, would reduce osteoclast activity and prostate cancer (PC-3) cell-induced osteoclast formation. Results Dasatinib inhibited RANKL-induced osteoclast differentiation of bone marrow-derived monocytes with an EC50 of 7.5 nM. PC-3 cells, a human prostate cancer cell line, were able to differentiate RAW 264.7 cells, a murine monocytic cell line, into osteoclasts and dasatinib inhibited this differentiation. In addition, conditioned medium from PC-3 cell cultures was able to differentiate RAW 264.7 cells into osteoclasts and this too, was inhibited by dasatinib. Even the lowest concentration of dasatinib, 1.25 nmol, inhibited osteoclast differentiation by 29%. Moreover, dasatinib inhibited osteoclast activity by 58% as measured by collagen 1 release. Experimental design We performed in vitro experiments utilizing the Src family kinase inhibitor dasatinib to target osteoclast activation as a means of inhibiting prostate cancer bone metastases. Conclusion Dasatinib inhibits osteoclast differentiation of mouse primary bone marrow-derived monocytes and PC-3 cell-induced osteoclast differentiation. Dasatinib also inhibits osteoclast degradation activity. Inhibiting osteoclast differentiation and activity may be an effective targeted therapy in patients with prostate cancer bone metastases. PMID:19855158

  4. STAT6 silencing induces hepatocellular carcinoma-derived cell apoptosis and growth inhibition by decreasing the RANKL expression.

    Science.gov (United States)

    Qing, Tian; Yamin, Zhang; Guijie, Wang; Yan, Jin; Zhongyang, Shen

    2017-08-01

    Signal transducer and activator of transcription-6 (STAT6) is highly expressed in various human cancers and considered a regulator of multiple biological processes in cancers, including cell apoptosis. Evidence has indicated that STAT6 predicts a worse prognosis in hepatocellular carcinoma (HCC) patients. The objective of this study was to investigate the effects and mechanism of STAT6 in human HCC cells. We found that STAT6 silencing significantly inhibited HepG2 and Hep3B cell survival and proliferation. We observed that depletion of STAT6 increased HepG2 and Hep3B cell apoptosis by using a histone DNA ELISA detection kit. STAT6 silencing induced expression of apoptosis-associated genes Bax and caspase-3/7 and inhibited anti-apoptosis gene Bcl-2 levels. We also observed that STAT6 silencing downregulated the expression of receptor activator of NF-κB ligand (RANKL). Our results demonstrated that treatment with pcDNA3.1-RANKL abolished STAT6 depletion-induced HepG2 and Hep3B cell apoptosis and growth inhibition. Based on these findings, we believe that RANKL plays a major role in STAT6-induced HCC cell apoptosis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  5. Sargachromenol from Sargassum micracanthum Inhibits the Lipopolysaccharide-Induced Production of Inflammatory Mediators in RAW 264.7 Macrophages

    Directory of Open Access Journals (Sweden)

    Eun-Jin Yang

    2013-01-01

    Full Text Available During our ongoing screening program designed to determine the anti-inflammatory potential of natural compounds, we isolated sargachromenol from Sargassum micracanthum. In the present study, we investigated the anti-inflammatory effects of sargachromenol on lipopolysaccharide (LPS-induced inflammation in murine RAW 264.7 macrophage cells and the underlying mechanisms. Sargachromenol significantly inhibited the LPS-induced production of nitric oxide (NO and prostaglandin E2 (PGE2 in a dose-dependent manner. It also significantly inhibited the protein expression of inducible NO synthase (iNOS and cyclooxygenase-2 (COX-2 in a dose-dependent manner in LPS-stimulated macrophage cells. Further analyses showed that sargachromenol decreased the cytoplasmic loss of inhibitor κBα (IκBα protein. These results suggest that sargachromenol may exert its anti-inflammatory effects on LPS-stimulated macrophage cells by inhibiting the activation of the NF-κB signaling pathway. In conclusion, to our knowledge, this is the first study to show that sargachromenol isolated from S. micracanthum has an effective anti-inflammatory activity. Therefore, sargachromenol might be useful for cosmetic, food, or medical applications requiring anti-inflammatory properties.

  6. Inhibition of Autophagy Potentiates Atorvastatin-Induced Apoptotic Cell Death in Human Bladder Cancer Cells in Vitro

    Science.gov (United States)

    Kang, Minyong; Jeong, Chang Wook; Ku, Ja Hyeon; Kwak, Cheol; Kim, Hyeon Hoe

    2014-01-01

    Statins are cholesterol reduction agents that exhibit anti-cancer activity in several human cancers. Because autophagy is a crucial survival mechanism for cancer cells under stress conditions, cooperative inhibition of autophagy acts synergistically with other anti-cancer drugs. Thus, this study investigates whether combined treatment of atorvastatin and autophagy inhibitors results in enhancing the cytotoxic effects of atorvastatin, upon human bladder cancer cells, T24 and J82, in vitro. To measure cell viability, we performed the EZ-Cytox cell viability assay. We examined apoptosis by flow cytometry using annexin-V/propidium iodide (PI and western blot using procaspase-3 and poly (ADP-ribose) polymerase (PARP) antibodies. To examine autophagy activation, we evaluated the co-localization of LC3 and LysoTracker by immunocytochemistry, as well as the expression of LC3 and p62/sequestosome-1 (SQSTM1) by western blot. In addition, we assessed the survival and proliferation of T24 and J82 cells by a clonogenic assay. We found that atorvastatin reduced the cell viability of T24 and J82 cells via apoptotic cell death and induced autophagy activation, shown by the co-localization of LC3 and LysoTracker. Moreover, pharmacologic inhibition of autophagy significantly enhanced atorvastatin-induced apoptosis in T24 and J82 cells. In sum, inhibition of autophagy potentiates atorvastatin-induced apoptotic cell death in human bladder cancer cells in vitro, providing a potential therapeutic approach to treat bladder cancer. PMID:24815071

  7. Rebaudioside A inhibits pentylenetetrazol-induced convulsions in rats

    Directory of Open Access Journals (Sweden)

    Yigit Uyanikgil

    2016-09-01

    Full Text Available The safety of patients with epilepsy consuming sweetening agents, which is becoming increasingly prevalent for various reasons, is a topic that should be emphasized as sensitively as it is for other diseases. Patients with epilepsy consume sweetening agents for different reasons such being diabetic or overweight. They can occasionally be exposed to sweetening agents unrestrainedly through consuming convenience food, primarily beverages. This study aimed to investigate the effects of rebaudioside A (Reb-A, which is a steviol glycoside produced from the herb Stevia rebaudiana (Bertoni, on epileptic seizures and convulsions induced by pentylenetetrazole (PTZ. Forty-eight male rats were used. Twenty-four rats were administered 35 mg/kg PTZ to trigger epileptiform activity; the remaining 24 rats were administered 70 mg/kg PTZ to trigger the convulsion model. The epileptiform activity was evaluated by spike percentage, whereas convulsion was evaluated by Racine's Convulsion Scale and the onset time of the first myoclonic jerk. Statistical analysis revealed a statistically significant decrease in the Racine's Convulsion Scale score and increase in the latency of first myoclonic jerk in a dose-dependent manner for the rat groups in which PTZ epilepsy had been induced and Reb-A had been administered. For the groups that were administered Reb-A, the spike decrease was apparent in a dose-dependent manner, based on the spike percentage calculation. These results indicated that Reb-A has positive effects on PTZ-induced convulsions.

  8. Interleukin-22 Inhibits Bleomycin-Induced Pulmonary Fibrosis

    Directory of Open Access Journals (Sweden)

    Minrui Liang

    2013-01-01

    Full Text Available Pulmonary fibrosis is a progressive and fatal fibrotic disease of the lungs with unclear etiology. Recent insight has suggested that early injury/inflammation of alveolar epithelial cells could lead to dysregulation of tissue repair driven by multiple cytokines. Although dysregulation of interleukin- (IL- 22 is involved in various pulmonary pathophysiological processes, the role of IL-22 in fibrotic lung diseases is still unclear and needs to be further addressed. Here we investigated the effect of IL-22 on alveolar epithelial cells in the bleomycin- (BLM- induced pulmonary fibrosis. BLM-treated mice showed significantly decreased level of IL-22 in the lung. IL-22 produced γδT cells were also decreased significantly both in the tissues of lungs and spleens. Administration of recombinant human IL-22 to alveolar epithelial cell line A549 cells ameliorated epithelial to mesenchymal transition (EMT and partially reversed the impaired cell viability induced by BLM. Furthermore, blockage of IL-22 deteriorated pulmonary fibrosis, with elevated EMT marker (α-smooth muscle actin (α-SMA and overactivated Smad2. Our results indicate that IL-22 may play a protective role in the development of BLM-induced pulmonary fibrosis and may suggest IL-22 as a novel immunotherapy tool in treating pulmonary fibrosis.

  9. Inhibition of radiation-induced polyuria by histamine receptor antagonists

    Energy Technology Data Exchange (ETDEWEB)

    Donlon, M.A.; Melia, J.A.; Helgeson, E.A.; Wolfe, W.W.

    1986-03-01

    In previous studies the authors have demonstrated that gamma radiation results in polyuria, which is preceded by polydypsia. This suggests that the increased thirst elicited by radiation causes increased urinary volume (UV). Histamine, which is released following radiation exposure, also elicits drinking by nonirradiated rats when administered exogenously. In this study the authors have investigated both the role of water deprivation and the effect of histamine receptor antagonists (HRA) on radiation-induced polyuria. Sprague-Dawley rats were housed individually in metabolic cages. Water was allowed ad libitum except in deprivation experiments where water was removed for 24 hr immediately following radiation. Cimetidine (CIM), an H2 HRA, and dexbromopheniramine (DXB), an H1 HRA, were administered i.p. (16 and 1 mg/kg, respectively) 30 min prior to irradiation (950 rads from a cobalt source). UV was determined at 24-hr intervals for 3 days preceding irradiation and 24 hr postirradiation. UV in DXB treated rats was significantly reduced 24 hr postirradiation (CON = 427 +/- 54%; DXB = 247 +/- 39% of preirradiated CON) compared to postirradiation control values. CIM did not affect postirradiation UV. These data suggest that radiation-induced polyuria is caused by polydypsia which is, in part, mediated by histamine induced by an H1 receptor.

  10. Inhibition of radiation-induced polyuria by histamine receptor antagonists

    International Nuclear Information System (INIS)

    Donlon, M.A.; Melia, J.A.; Helgeson, E.A.; Wolfe, W.W.

    1986-01-01

    In previous studies the authors have demonstrated that gamma radiation results in polyuria, which is preceded by polydypsia. This suggests that the increased thirst elicited by radiation causes increased urinary volume (UV). Histamine, which is released following radiation exposure, also elicits drinking by nonirradiated rats when administered exogenously. In this study the authors have investigated both the role of water deprivation and the effect of histamine receptor antagonists (HRA) on radiation-induced polyuria. Sprague-Dawley rats were housed individually in metabolic cages. Water was allowed ad libitum except in deprivation experiments where water was removed for 24 hr immediately following radiation. Cimetidine (CIM), an H2 HRA, and dexbromopheniramine (DXB), an H1 HRA, were administered i.p. (16 and 1 mg/kg, respectively) 30 min prior to irradiation (950 rads from a cobalt source). UV was determined at 24-hr intervals for 3 days preceding irradiation and 24 hr postirradiation. UV in DXB treated rats was significantly reduced 24 hr postirradiation (CON = 427 +/- 54%; DXB = 247 +/- 39% of preirradiated CON) compared to postirradiation control values. CIM did not affect postirradiation UV. These data suggest that radiation-induced polyuria is caused by polydypsia which is, in part, mediated by histamine induced by an H1 receptor

  11. Estrogen receptor beta signaling inhibits PDGF induced human airway smooth muscle proliferation.

    Science.gov (United States)

    Ambhore, Nilesh Sudhakar; Katragadda, Rathnavali; Raju Kalidhindi, Rama Satyanarayana; Thompson, Michael A; Pabelick, Christina M; Prakash, Y S; Sathish, Venkatachalem

    2018-04-20

    Airway smooth muscle (ASM) cell hyperplasia driven by persistent inflammation is a hallmark feature of remodeling in asthma. Sex steroid signaling in the lungs is of considerable interest, given epidemiological data showing more asthma in pre-menopausal women and aging men. Our previous studies demonstrated that estrogen receptor (ER) expression increases in asthmatic human ASM; however, very limited data are available regarding differential roles of ERα vs. ERβ isoforms in human ASM cell proliferation. In this study, we evaluated the effect of selective ERα and ERβ modulators on platelet-derived growth factor (PDGF)-stimulated ASM proliferation and the mechanisms involved. Asthmatic and non-asthmatic primary human ASM cells were treated with PDGF, 17β-estradiol, ERα-agonist and/or ERβ-agonist and/or G-protein-coupled estrogen receptor 30 (GPR30/GPER) agonist and proliferation was measured using MTT and CyQuant assays followed by cell cycle analysis. Transfection of small interfering RNA (siRNA) ERα and ERβ significantly altered the human ASM proliferation. The specificity of siRNA transfection was confirmed by Western blot analysis. Gene and protein expression of cell cycle-related antigens (PCNA and Ki67) and C/EBP were measured by RT-PCR and Western analysis, along with cell signaling proteins. PDGF significantly increased ASM proliferation in non-asthmatic and asthmatic cells. Treatment with PPT showed no significant effect on PDGF-induced proliferation, whereas WAY interestingly suppressed proliferation via inhibition of ERK1/2, Akt, and p38 signaling. PDGF-induced gene expression of PCNA, Ki67 and C/EBP in human ASM was significantly lower in cells pre-treated with WAY. Furthermore, WAY also inhibited PDGF-activated PCNA, C/EBP, cyclin-D1, and cyclin-E. Overall, we demonstrate ER isoform-specific signaling in the context of ASM proliferation. Activation of ERβ can diminish remodeling in human ASM by inhibiting pro-proliferative signaling pathways

  12. Effects of ceramide inhibition on radiation-induced apoptosis in human leukemia MOLT-4 cells

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Eriko; Inanami, Osamu; Asanuma, Taketoshi; Kuwabara, Mikinori [Hokkaido Univ., Graduate School of Veterinary Medicine, Sapporo, Hokkaido (Japan)

    2006-03-15

    In the present study, using inhibitors of ceramide synthase (fumonisin B{sub 1}), ketosphinganine synthetase (L-cycloserine), acid sphingomyelinase (D609 and desipramine) and neutral sphingomyelinase (GW4869), the role of ceramide in X-ray-induced apoptosis was investigated in MOLT-4 cells. The diacylglycerol kinase (DGK) assay showed that the intracellular concentration of ceramide increased time-dependently after X irradiation of cells, and this radiation-induced accumulation of ceramide did not occur prior to the appearance of apoptotic cells. Treatment with D609 significantly inhibited radiation-induced apoptosis, but did not inhibit the increase of intracellular ceramide. Treatment with desipramine or GW4869 prevented neither radiation-induced apoptosis nor the induced increase of ceramide. On the other hand, fumonisin B{sub 1} and L-cycloserine had no effect on the radiation-induced induction of apoptosis, in spite of significant inhibition of the radiation-induced ceramide. From these results, it was suggested that the increase of the intracellular concentration of ceramide was not essential for radiation-induced apoptosis in MOLT-4 cells. (author)

  13. Effects of ceramide inhibition on radiation-induced apoptosis in human leukemia MOLT-4 cells

    International Nuclear Information System (INIS)

    Takahashi, Eriko; Inanami, Osamu; Asanuma, Taketoshi; Kuwabara, Mikinori

    2006-01-01

    In the present study, using inhibitors of ceramide synthase (fumonisin B 1 ), ketosphinganine synthetase (L-cycloserine), acid sphingomyelinase (D609 and desipramine) and neutral sphingomyelinase (GW4869), the role of ceramide in X-ray-induced apoptosis was investigated in MOLT-4 cells. The diacylglycerol kinase (DGK) assay showed that the intracellular concentration of ceramide increased time-dependently after X irradiation of cells, and this radiation-induced accumulation of ceramide did not occur prior to the appearance of apoptotic cells. Treatment with D609 significantly inhibited radiation-induced apoptosis, but did not inhibit the increase of intracellular ceramide. Treatment with desipramine or GW4869 prevented neither radiation-induced apoptosis nor the induced increase of ceramide. On the other hand, fumonisin B 1 and L-cycloserine had no effect on the radiation-induced induction of apoptosis, in spite of significant inhibition of the radiation-induced ceramide. From these results, it was suggested that the increase of the intracellular concentration of ceramide was not essential for radiation-induced apoptosis in MOLT-4 cells. (author)

  14. Dopamine induces growth inhibition and vascular normalization through reprogramming M2-polarized macrophages in rat C6 glioma

    International Nuclear Information System (INIS)

    Qin, Tian; Wang, Chenlong; Chen, Xuewei; Duan, Chenfan; Zhang, Xiaoyan; Zhang, Jing; Chai, Hongyan; Tang, Tian; Chen, Honglei; Yue, Jiang; Li, Ying; Yang, Jing

    2015-01-01

    Dopamine (DA), a monoamine catecholamine neurotransmitter with antiangiogenic activity, stabilizes tumor vessels in colon, prostate and ovarian cancers, thus increases chemotherapeutic efficacy. Here, in the rat C6 glioma models, we investigated the vascular normalization effects of DA and its mechanisms of action. DA (25, 50 mg/kg) inhibited tumor growth, while a precursor of DA (levodopa) prolonged the survival time of rats bearing orthotopic C6 glioma. DA improved tumor perfusion, with significant effects from day 3, and a higher level at days 5 to 7. In addition, DA decreased microvessel density and hypoxia-inducible factor-1α expression in tumor tissues, while increasing the coverage of pericyte. Conversely, an antagonist of dopamine receptor 2 (DR2) (eticlopride) but not DR1 (butaclamol) abrogated DA-induced tumor regression and vascular normalization. Furthermore, DA improved the delivery and efficacy of temozolomide therapy. Importantly, DA increased representative M1 markers (iNOS, CXCL9, etc.), while decreasing M2 markers (CD206, arginase-1, etc.). Depletion of macrophages by clodronate or zoledronic acid attenuated the effects of DA. Notably, DA treatment induced M2-to-M1 polarization in RAW264.7 cells and mouse peritoneal macrophages, and enhanced the migration of pericyte-like cells (10T1/2), which was reversed by eticlopride or DR2-siRNA. Such changes were accompanied by the downregulation of VEGF/VEGFR2 signaling. In summary, DA induces growth inhibition and vascular normalization through reprogramming M2-polarized macrophages. Thus, targeting the tumor microvasculature by DA represents a promising strategy for human glioma therapy. - Highlights: • Dopamine induces tumor growth inhibition and vascular normalization in rat C6 glioma. • Dopamine switches macrophage phenotype from M2 to M1. • Dopamine-induced vascular normalization is mediated by macrophage polarization. • Dopamine is a promising agent targeting the microvasculature in tumor

  15. Dopamine induces growth inhibition and vascular normalization through reprogramming M2-polarized macrophages in rat C6 glioma

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Tian; Wang, Chenlong; Chen, Xuewei; Duan, Chenfan; Zhang, Xiaoyan [Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Zhang, Jing [Animal Experimental Center of Wuhan University, Wuhan 430071 (China); Chai, Hongyan [Center for Gene Diagnosis, Zhongnan Hospital, Wuhan University, Wuhan 430071 (China); Tang, Tian [Department of Oncology, Renmin Hospital of Wuhan University, Wuhan 430060 (China); Chen, Honglei [Department of Pathology and Pathophysiology, School of Medicine, Wuhan University, Wuhan 430071 (China); Yue, Jiang [Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Li, Ying, E-mail: lyying0@163.com [Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Yang, Jing, E-mail: yangjingliu2013@163.com [Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China)

    2015-07-15

    Dopamine (DA), a monoamine catecholamine neurotransmitter with antiangiogenic activity, stabilizes tumor vessels in colon, prostate and ovarian cancers, thus increases chemotherapeutic efficacy. Here, in the rat C6 glioma models, we investigated the vascular normalization effects of DA and its mechanisms of action. DA (25, 50 mg/kg) inhibited tumor growth, while a precursor of DA (levodopa) prolonged the survival time of rats bearing orthotopic C6 glioma. DA improved tumor perfusion, with significant effects from day 3, and a higher level at days 5 to 7. In addition, DA decreased microvessel density and hypoxia-inducible factor-1α expression in tumor tissues, while increasing the coverage of pericyte. Conversely, an antagonist of dopamine receptor 2 (DR2) (eticlopride) but not DR1 (butaclamol) abrogated DA-induced tumor regression and vascular normalization. Furthermore, DA improved the delivery and efficacy of temozolomide therapy. Importantly, DA increased representative M1 markers (iNOS, CXCL9, etc.), while decreasing M2 markers (CD206, arginase-1, etc.). Depletion of macrophages by clodronate or zoledronic acid attenuated the effects of DA. Notably, DA treatment induced M2-to-M1 polarization in RAW264.7 cells and mouse peritoneal macrophages, and enhanced the migration of pericyte-like cells (10T1/2), which was reversed by eticlopride or DR2-siRNA. Such changes were accompanied by the downregulation of VEGF/VEGFR2 signaling. In summary, DA induces growth inhibition and vascular normalization through reprogramming M2-polarized macrophages. Thus, targeting the tumor microvasculature by DA represents a promising strategy for human glioma therapy. - Highlights: • Dopamine induces tumor growth inhibition and vascular normalization in rat C6 glioma. • Dopamine switches macrophage phenotype from M2 to M1. • Dopamine-induced vascular normalization is mediated by macrophage polarization. • Dopamine is a promising agent targeting the microvasculature in tumor

  16. Gardenia jasminoides extracts and gallic acid inhibit lipopolysaccharide-induced inflammation by suppression of JNK2/1 signaling pathways in BV-2 cells

    Directory of Open Access Journals (Sweden)

    Wen-Hung Lin

    2015-06-01

    Conclusion:Taken together, these results indicate that the protective mechanism of the GJ extract involves an antioxidant effect and inhibition of JNK2/1 MAP kinase and COX-2 expressions in LPS-induced inflammation of BV-2 cells.

  17. IFN gamma induces monopoiesis and inhibits neutrophil development during inflammation

    NARCIS (Netherlands)

    de Bruin, Alexander M.; Libregts, Sten F.; Valkhof, Marijke; Boon, Louis; Touw, Ivo P.; Nolte, Martijn A.

    2012-01-01

    Steady-state hematopoiesis is altered on infection, but the cellular and molecular mechanisms driving these changes are largely unknown. Modulation of hematopoiesis is essential to increase the output of the appropriate type of effector cell required to combat the invading pathogen. In the present

  18. Novel derivative of aminobenzenesulfonamide (3c) induces apoptosis in colorectal cancer cells through ROS generation and inhibits cell migration.

    Science.gov (United States)

    Al-Khayal, Khayal; Alafeefy, Ahmed; Vaali-Mohammed, Mansoor-Ali; Mahmood, Amer; Zubaidi, Ahmed; Al-Obeed, Omar; Khan, Zahid; Abdulla, Maha; Ahmad, Rehan

    2017-01-03

    Colorectal cancer (CRC) is the 3 rd most common type of cancer worldwide. New anti-cancer agents are needed for treating late stage colorectal cancer as most of the deaths occur due to cancer metastasis. A recently developed compound, 3c has shown to have potent antitumor effect; however the mechanism underlying the antitumor effect remains unknown. 3c-induced inhibition of proliferation was measured in the absence and presence NAC using MTT in HT-29 and SW620 cells and xCELLigence RTCA DP instrument. 3c-induced apoptotic studies were performed using flow cytometry. 3c-induced redox alterations were measured by ROS production using fluorescence plate reader and flow cytometry and mitochondrial membrane potential by flow cytometry; NADPH and GSH levels were determined by colorimetric assays. Bcl2 family protein expression and cytochrome c release and PARP activation was done by western blotting. Caspase activation was measured by ELISA. Cell migration assay was done using the real time xCELLigence RTCA DP system in SW620 cells and wound healing assay in HT-29. Many anticancer therapeutics exert their effects by inducing reactive oxygen species (ROS). In this study, we demonstrate that 3c-induced inhibition of cell proliferation is reversed by the antioxidant, N-acetylcysteine, suggesting that 3c acts via increased production of ROS in HT-29 cells. This was confirmed by the direct measurement of ROS in 3c-treated colorectal cancer cells. Additionally, treatment with 3c resulted in decreased NADPH and glutathione levels in HT-29 cells. Further, investigation of the apoptotic pathway showed increased release of cytochrome c resulting in the activation of caspase-9, which in turn activated caspase-3 and -6. 3c also (i) increased p53 and Bax expression, (ii) decreased Bcl2 and BclxL expression and (iii) induced PARP cleavage in human colorectal cancer cells. Confirming our observations, NAC significantly