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Sample records for cyclooxygenase-2 inhibition protects

  1. Inhibition of Cyclooxygenase-2 Prevents Chronic and Recurrent Cystitis

    PubMed Central

    Hannan, Thomas J.; Roberts, Pacita L.; Riehl, Terrence E.; van der Post, Sjoerd; Binkley, Jana M.; Schwartz, Drew J.; Miyoshi, Hiroyuki; Mack, Matthias; Schwendener, Reto A.; Hooton, Thomas M.; Stappenbeck, Thaddeus S.; Hansson, Gunnar C.; Stenson, William F.; Colonna, Marco; Stapleton, Ann E.; Hultgren, Scott J.

    2014-01-01

    The spread of multidrug-resistant microorganisms globally has created an urgent need for novel therapeutic strategies to combat urinary tract infections (UTIs). Immunomodulatory therapy may provide benefit, as treatment of mice with dexamethasone during acute UTI improved outcome by reducing the development of chronic cystitis, which predisposes to recurrent infection. Here we discovered soluble biomarkers engaged in myeloid cell development and chemotaxis that were predictive of future UTI recurrence when elevated in the sera of young women with UTI. Translation of these findings revealed that temperance of the neutrophil response early during UTI, and specifically disruption of bladder epithelial transmigration of neutrophils by inhibition of cyclooxygenase-2, protected mice against chronic and recurrent cystitis. Further, proteomics identified bladder epithelial remodeling consequent to chronic infection that enhances sensitivity to neutrophil damage. Thus, cyclooxygenase-2 expression during acute UTI is a critical molecular trigger determining disease outcome and drugs targeting cyclooxygenase-2 could prevent recurrent UTI. PMID:26125048

  2. Cyclooxygenase-2 inhibition reduces stress-induced affective pathology.

    PubMed

    Gamble-George, Joyonna Carrie; Baldi, Rita; Halladay, Lindsay; Kocharian, Adrina; Hartley, Nolan; Silva, Carolyn Grace; Roberts, Holly; Haymer, Andre; Marnett, Lawrence J; Holmes, Andrew; Patel, Sachin

    2016-01-01

    Mood and anxiety disorders are the most prevalent psychiatric conditions and are exacerbated by stress. Recent studies have suggested cyclooxygenase-2 (COX-2) inhibition could represent a novel treatment approach or augmentation strategy for affective disorders including anxiety disorders and major depression. We show that traditional COX-2 inhibitors and a newly developed substrate-selective COX-2 inhibitor (SSCI) reduce a variety of stress-induced behavioral pathologies in mice. We found that these behavioral effects were associated with a dampening of neuronal excitability in the basolateral amygdala (BLA) ex vivo and in vivo, and were mediated by small-conductance calcium-activated potassium (SK) channel and CB1 cannabinoid receptor activation. Taken together, these data provide further support for the potential utility of SSCIs, as well as traditional COX-2 inhibitors, as novel treatment approaches for stress-related psychiatric disorders. PMID:27162170

  3. Cyclooxygenase-2 inhibition reduces stress-induced affective pathology

    PubMed Central

    Gamble-George, Joyonna Carrie; Baldi, Rita; Halladay, Lindsay; Kocharian, Adrina; Hartley, Nolan; Silva, Carolyn Grace; Roberts, Holly; Haymer, Andre; Marnett, Lawrence J; Holmes, Andrew; Patel, Sachin

    2016-01-01

    Mood and anxiety disorders are the most prevalent psychiatric conditions and are exacerbated by stress. Recent studies have suggested cyclooxygenase-2 (COX-2) inhibition could represent a novel treatment approach or augmentation strategy for affective disorders including anxiety disorders and major depression. We show that traditional COX-2 inhibitors and a newly developed substrate-selective COX-2 inhibitor (SSCI) reduce a variety of stress-induced behavioral pathologies in mice. We found that these behavioral effects were associated with a dampening of neuronal excitability in the basolateral amygdala (BLA) ex vivo and in vivo, and were mediated by small-conductance calcium-activated potassium (SK) channel and CB1 cannabinoid receptor activation. Taken together, these data provide further support for the potential utility of SSCIs, as well as traditional COX-2 inhibitors, as novel treatment approaches for stress-related psychiatric disorders. DOI: http://dx.doi.org/10.7554/eLife.14137.001 PMID:27162170

  4. The inhibition of 2-arachidonoyl-glycerol (2-AG) biosynthesis, rather than enhancing striatal damage, protects striatal neurons from malonate-induced death: a potential role of cyclooxygenase-2-dependent metabolism of 2-AG

    PubMed Central

    Valdeolivas, S; Pazos, M R; Bisogno, T; Piscitelli, F; Iannotti, F A; Allarà, M; Sagredo, O; Di Marzo, V; Fernández-Ruiz, J

    2013-01-01

    The cannabinoid CB2 receptor, which is activated by the endocannabinoid 2-arachidonoyl-glycerol (2-AG), protects striatal neurons from apoptotic death caused by the local administration of malonate, a rat model of Huntington's disease (HD). In the present study, we investigated whether endocannabinoids provide tonic neuroprotection in this HD model, by examining the effect of O-3841, an inhibitor of diacylglycerol lipases, the enzymes that catalyse 2-AG biosynthesis, and JZL184 or OMDM169, two inhibitors of 2-AG inactivation by monoacylglycerol lipase (MAGL). The inhibitors were injected in rats with the striatum lesioned with malonate, and several biochemical and morphological parameters were measured in this brain area. Similar experiments were also conducted in vitro in cultured M-213 cells, which have the phenotypic characteristics of striatal neurons. O-3841 produced a significant reduction in the striatal levels of 2-AG in animals lesioned with malonate. However, surprisingly, the inhibitor attenuated malonate-induced GABA and BDNF deficiencies and the reduction in Nissl staining, as well as the increase in GFAP immunostaining. In contrast, JZL184 exacerbated malonate-induced striatal damage. Cyclooxygenase-2 (COX-2) was induced in the striatum 24 h after the lesion simultaneously with other pro-inflammatory responses. The COX-2-derived 2-AG metabolite, prostaglandin E2 glyceryl ester (PGE2-G), exacerbated neurotoxicity, and this effect was antagonized by the blockade of PGE2-G action with AGN220675. In M-213 cells exposed to malonate, in which COX-2 was also upregulated, JZL184 worsened neurotoxicity, and this effect was attenuated by the COX-2 inhibitor celecoxib or AGN220675. OMDM169 also worsened neurotoxicity and produced measurable levels of PGE2-G. In conclusion, the inhibition of 2-AG biosynthesis is neuroprotective in rats lesioned with malonate, possibly through the counteraction of the formation of pro-neuroinflammatory PGE2-G, formed from COX-2

  5. The inhibition of 2-arachidonoyl-glycerol (2-AG) biosynthesis, rather than enhancing striatal damage, protects striatal neurons from malonate-induced death: a potential role of cyclooxygenase-2-dependent metabolism of 2-AG.

    PubMed

    Valdeolivas, S; Pazos, M R; Bisogno, T; Piscitelli, F; Iannotti, F A; Allarà, M; Sagredo, O; Di Marzo, V; Fernández-Ruiz, J

    2013-10-17

    The cannabinoid CB2 receptor, which is activated by the endocannabinoid 2-arachidonoyl-glycerol (2-AG), protects striatal neurons from apoptotic death caused by the local administration of malonate, a rat model of Huntington's disease (HD). In the present study, we investigated whether endocannabinoids provide tonic neuroprotection in this HD model, by examining the effect of O-3841, an inhibitor of diacylglycerol lipases, the enzymes that catalyse 2-AG biosynthesis, and JZL184 or OMDM169, two inhibitors of 2-AG inactivation by monoacylglycerol lipase (MAGL). The inhibitors were injected in rats with the striatum lesioned with malonate, and several biochemical and morphological parameters were measured in this brain area. Similar experiments were also conducted in vitro in cultured M-213 cells, which have the phenotypic characteristics of striatal neurons. O-3841 produced a significant reduction in the striatal levels of 2-AG in animals lesioned with malonate. However, surprisingly, the inhibitor attenuated malonate-induced GABA and BDNF deficiencies and the reduction in Nissl staining, as well as the increase in GFAP immunostaining. In contrast, JZL184 exacerbated malonate-induced striatal damage. Cyclooxygenase-2 (COX-2) was induced in the striatum 24 h after the lesion simultaneously with other pro-inflammatory responses. The COX-2-derived 2-AG metabolite, prostaglandin E2 glyceryl ester (PGE2-G), exacerbated neurotoxicity, and this effect was antagonized by the blockade of PGE2-G action with AGN220675. In M-213 cells exposed to malonate, in which COX-2 was also upregulated, JZL184 worsened neurotoxicity, and this effect was attenuated by the COX-2 inhibitor celecoxib or AGN220675. OMDM169 also worsened neurotoxicity and produced measurable levels of PGE2-G. In conclusion, the inhibition of 2-AG biosynthesis is neuroprotective in rats lesioned with malonate, possibly through the counteraction of the formation of pro-neuroinflammatory PGE2-G, formed from COX-2

  6. Chronic inhibition of cyclooxygenase-2 attenuates antibody responses against vaccinia infection.

    PubMed

    Bernard, Matthew P; Bancos, Simona; Chapman, Timothy J; Ryan, Elizabeth P; Treanor, John J; Rose, Robert C; Topham, David J; Phipps, Richard P

    2010-02-01

    Generation of optimal humoral immunity to vaccination is essential to protect against devastating infectious agents such as the variola virus that causes smallpox. Vaccinia virus (VV), employed as a vaccine against smallpox, provides an important model of infection. Herein, we evaluated the importance cyclooxygenase-2 (Cox-2) in immunity to VV using Cox-2 deficient mice and Cox-2 selective inhibitory drugs. The effects of Cox-2 inhibition on antibody responses to live viruses such as vaccinia have not been previously described. Here, we used VV infection in Cox-2 deficient mice and in mice chronically treated with Cox-2 selective inhibitors and show that the frequency of VV-specific B cells was reduced, as well as the production of neutralizing IgG. VV titers were approximately 70 times higher in mice treated with a Cox-2 selective inhibitor. Interestingly, Cox-2 inhibition also reduced the frequency of IFN-gamma producing CD4(+) T helper cells, important for class switching. The significance of these results is that the chronic use of non-steroidal anti-inflammatory drugs (NSAIDs), and other drugs that inhibit Cox-2 activity or expression, blunt the ability of B cells to produce anti-viral antibodies, thereby making vaccines less effective and possibly increasing susceptibility to viral infection. These new findings support an essential role for Cox-2 in regulating humoral immunity.

  7. Chronic Inhibition of Cyclooxygenase-2 Attenuates Antibody Responses against Vaccinia Infection

    PubMed Central

    Bernard, Matthew P.; Bancos, Simona; Chapman, Timothy J.; Ryan, Elizabeth P.; Treanor, John J.; Rose, Robert C.; Topham, David J.; Phipps, Richard P.

    2010-01-01

    Generation of optimal humoral immunity to vaccination is essential to protect against devastating infectious agents such as the variola virus that causes smallpox. Vaccinia virus (VV), employed as a vaccine against smallpox, provides an important model of infection. Herein, we evaluated the importance cyclooxygenase-2 (Cox-2) in immunity to VV using Cox-2 deficient mice and Cox-2 selective inhibitory drugs. The effects of Cox-2 inhibition on antibody responses to live viruses such as vaccinia have not been previously described. Here, we used VV infection in Cox-2 deficient mice and in mice chronically treated with Cox-2 selective inhibitors and show that the frequency of VV-specific B cells was reduced, as well as the production of neutralizing IgG. VV titers were approximately 70 times higher in mice treated with a Cox-2 selective inhibitor. Interestingly, Cox-2 inhibition also reduced the frequency of IFN-γ producing CD4+ T helper cells, important for class switching. The significance of these results is that the chronic use of NSAIDs, and other drugs that inhibit Cox-2 activity or expression, blunt the ability of B cells to produce anti-viral antibodies, thereby making vaccines less effective and possibly increasing susceptibility to viral infection. These new findings support an essential role for Cox-2 in regulating humoral immunity. PMID:19941994

  8. Exploring the Molecular Determinants of Substrate-Selective Inhibition of Cyclooxygenase-2 by Lumiracoxib

    PubMed Central

    Windsor, Matthew A.; Valk, Pieter L.; Xu, Shu; Banerjee, Surajit; Marnett, Lawrence J.

    2013-01-01

    Lumiracoxib is a substrate-selective inhibitor of endocannabinoid oxygenation by cyclooxygenase-2 (COX-2). We assayed a series of lumiracoxib derivatives to identify the structural determinants of substrate-selective inhibition. The hydrogen-bonding potential of the substituents at the ortho positions of the aniline ring dictated the potency and substrate selectivity of the inhibitors. The presence of a 5’-methyl group on the phenylacetic acid ring increased the potency of molecules with a single ortho substituent. Des-fluorolumiracoxib (2) was the most potent and selective inhibitor of endocannabinoid oxygenation. The positioning of critical substituents in the binding site was identified from a 2.35 Å crystal structure of lumiracoxib bound to COX-2. PMID:24060487

  9. Cardiovascular effects of selective cyclooxygenase-2 inhibitors.

    PubMed

    Krum, Henry; Liew, Danny; Aw, Juan; Haas, Steven

    2004-03-01

    Selective cyclooxygenase-2 inhibitors represent a significant advance in the management of inflammatory disorders. They have similar efficacy to nonselective 'conventional' nonsteroidal anti-inflammatory drugs, but a superior gastrointestinal safety profile. However, a significant caveat is the perceived potential of cyclooxygenase-2 inhibitors to cause adverse cardiovascular effects, an issue first raised by the Vioxx Gastrointestinal Outcomes Research (VIGOR) study of rofecoxib (Vioxx, Merck & Co. Inc.). Mechanisms by which cyclooxygenase-2 inhibitors may increase cardiovascular risk are selective inhibition of prostaglandin I2 over thromboxane A2 within the eicosanoid pathway, which promotes thrombosis, and inhibition of prostaglandins E2 and I2 within the kidney, which leads to sodium and water retention and blood pressure elevation. In spite of this, the cardiovascular findings from VIGOR are not firmly supported by observations from large cohort studies and other clinical trials of selective cyclooxygenase-2 inhibitors, including the Celecoxib Long-term Arthritis Safety Study. The two main theories that explain the VIGOR findings are that the comparator used (naproxen; Naprosyn, Roche) is cardioprotective and that very high doses of rofecoxib were used, but at present neither is backed by firm evidence. Indeed, there is now early evidence that selective cyclooxygenase-2 inhibition with celecoxib may even protect against the progression of cardiovascular disease, on the basis that cyclooxygenase-2 mediates key processes in atherothrombosis. Currently, it is not clear what the net cardiovascular effects of cyclooxygenase-2 inhibitors are. The data are inconsistent and at best, speculative. It may be also that celecoxib and rofecoxib differ in their cardiovascular effects. Clarification of these issues is of vital importance given the vast number of patients presently taking both types of cyclooxygenase-2 inhibitors. Therefore, what is clear in this situation is

  10. Substrate-Selective Inhibition of Cyclooxygenase-2: Development and Evaluation of Achiral Profen Probes

    PubMed Central

    2012-01-01

    Cyclooxygenase-2 (COX-2) oxygenates arachidonic acid and the endocannabinoids 2-arachidonoylglycerol (2-AG) and arachidonoylethanolamide (AEA). We recently reported that (R)-profens selectively inhibit endocannabinoid oxygenation but not arachidonic acid oxygenation. In this work, we synthesized achiral derivatives of five profen scaffolds and evaluated them for substrate-selective inhibition using in vitro and cellular assays. The size of the substituents dictated the inhibitory strength of the analogs, with smaller substituents enabling greater potency but less selectivity. Inhibitors based on the flurbiprofen scaffold possessed the greatest potency and selectivity, with desmethylflurbiprofen (3a) exhibiting an IC50 of 0.11 μM for inhibition of 2-AG oxygenation. The crystal structure of desmethylflurbiprofen complexed to mCOX-2 demonstrated a similar binding mode to other profens. Desmethylflurbiprofen exhibited a half-life in mice comparable to that of ibuprofen. The data presented suggest that achiral profens can act as lead molecules toward in vivo probes of substrate-selective COX-2 inhibition. PMID:22984634

  11. Substrate-Selective Inhibition of Cyclooxygenase-2: Development and Evaluation of Achiral Profen Probes.

    PubMed

    Windsor, Matthew A; Hermanson, Daniel J; Kingsley, Philip J; Xu, Shu; Crews, Brenda C; Ho, Winnie; Keenan, Catherine M; Banerjee, Surajit; Sharkey, Keith A; Marnett, Lawrence J

    2012-09-13

    Cyclooxygenase-2 (COX-2) oxygenates arachidonic acid and the endocannabinoids 2-arachidonoylglycerol (2-AG) and arachidonoylethanolamide (AEA). We recently reported that (R)-profens selectively inhibit endocannabinoid oxygenation but not arachidonic acid oxygenation. In this work, we synthesized achiral derivatives of five profen scaffolds and evaluated them for substrate-selective inhibition using in vitro and cellular assays. The size of the substituents dictated the inhibitory strength of the analogs, with smaller substituents enabling greater potency but less selectivity. Inhibitors based on the flurbiprofen scaffold possessed the greatest potency and selectivity, with desmethylflurbiprofen (3a) exhibiting an IC(50) of 0.11 μM for inhibition of 2-AG oxygenation. The crystal structure of desmethylflurbiprofen complexed to mCOX-2 demonstrated a similar binding mode to other profens. Desmethylflurbiprofen exhibited a half-life in mice comparable to that of ibuprofen. The data presented suggest that achiral profens can act as lead molecules toward in vivo probes of substrate-selective COX-2 inhibition.

  12. Cyclooxygenase-2 inhibition attenuates hypoxic cancer cells induced m2-polarization of macrophages.

    PubMed

    Dubey, P; Shrivastava, R; Tripathi, C; Jain, N K; Tewari, B N; Lone, M-U-D; Baghel, K S; Kumar, V; Misra, S; Bhadauria, S; Bhatt, M L B

    2014-09-12

    Tumor-associated macrophages (TAMs), represent a major subpopulation of tumor infiltrating immune cells. These alternatively activated M2-polarized macrophages are well known for their pro-tumor functions. Owing to their established role in potentiating tumor-neovasculogenesis and metastasis, TAMs have emerged as promising target for anti-cancer immunotherapy. One of the key TAMs related phenomenon that is amenable to therapeutic intervention is their phenotype switching into alternatively activated M2-polarized macrophages. Hindering macrophage polarization towards a pro-tumor M2 phenotype, or better still reprogramming the M2 like TAMs towards M1 subtype is being considered a beneficial anti-cancer strategy. Hypoxic tumor milieu has been proposed as one of the most plausible factor governing M2-polarization of macrophages. We recently demonstrated that hypoxic tumor cells imparted a pro—angiogenic M2 skewed phenotype to macrophages. Furthermore, sizeable body of data indicates for participation of cyclooxygenase-2 (COX-2) in macrophage polarization. Concordantly, inhibition of COX-2 is associated with impaired macrophage polarization. Prompted by this in the current study we decided to explore if inhibition of COX-2 activity via chemical inhibitors may prevent hypoxic cancer cell induced M2-polarization of macrophages. We observed that treatment with Flunixin meglumine, an established preferential inhibitor of COX-2 activity markedly inhibited hypoxic cancer cell induced of M2-polarization of macrophages thereby indicating for usage of COX-2 inhibition as possible anti-cancer treatment modality.

  13. Selective inhibition of inducible cyclooxygenase 2 in vivo is antiinflammatory and nonulcerogenic.

    PubMed Central

    Masferrer, J L; Zweifel, B S; Manning, P T; Hauser, S D; Leahy, K M; Smith, W G; Isakson, P C; Seibert, K

    1994-01-01

    We have examined the role of cyclooxygenase 2 (COX-2) in a model of inflammation in vivo. Carrageenan administration to the subcutaneous rat air pouch induces a rapid inflammatory response characterized by high levels of prostaglandins (PGs) and leukotrienes in the fluid exudate. The time course of the induction of COX-2 mRNA and protein coincided with the production of PGs in the pouch tissue and cellular infiltrate. Carrageenan-induced COX-2 immunoreactivity was localized to macrophages obtained from the fluid exudate as well as to the inner surface layer of cells within the pouch lining. Dexamethasone inhibited both COX-2 expression and PG synthesis in the fluid exudate but failed to inhibit PG synthesis in the stomach. Furthermore, NS-398, a selective COX-2 inhibitor, and indomethacin, a nonselective COX-1/COX-2 inhibitor, blocked proinflammatory PG synthesis in the air pouch. In contrast, only indomethacin blocked gastric PG and, additionally, produced gastric lesions. These results suggest that inhibitors of COX-2 are potent antiinflammatory agents which do not produce the typical side effects (e.g., gastric ulcers) associated with the nonselective, COX-1-directed antiinflammatory drugs. Images PMID:8159730

  14. Cyclooxygenase-2 inhibitor, celecoxib, inhibits leiomyoma cell proliferation through the nuclear factor κB pathway.

    PubMed

    Park, Seung Bin; Jee, Byung Chul; Kim, Seok Hyun; Cho, Yeon Jean; Han, Myoungseok

    2014-09-01

    Our aim was to investigate whether celecoxib, a cyclooxygenase 2 (COX-2) inhibitor, decreases the in vitro proliferation of leiomyoma cells if the inflammatory pathway is blocked. Menstruation is an inflammation of uterus that produces cytokines and prostanoids, but the inflammatory mechanism underlying the growth of leiomyoma remains unexplained. Using in vitro cultures of leiomyoma cells obtained from 5 patients who underwent hysterectomy, cell proliferation, inflammatory signaling, transcription factors, growth factors, and extracellular matrix were examined by (4,5-dimethylthiaxol-2-yi)-2,5-diphenyltetraxolium bromide assay, immunoblotting, and quantitative polymerase chain reaction. Prostaglandin E2 was used to induce menstruation-like condition in the cells. We found that celecoxib inhibited COX-2 through the expression of nuclear factor κB in the cells. Celcoxib also decreased the gene expression of interleukin 6, tumor necrosis factor α, collagen A, fibronectin, platelet-derived growth factor, epidermal growth factor, and transforming growth factor β. In conclusion, the present study indicated that celecoxib could inhibit leiomyoma cell proliferation through blocking the inflammatory pathway that is probably one of the mechanisms underlying its pathogenesis.

  15. Inhibition of cyclooxygenase-2 by NS398 attenuates noise-induced hearing loss in mice

    PubMed Central

    Sun, Yu; Yu, Jintao; Lin, Xi; Tang, Wenxue

    2016-01-01

    Noise-induced hearing loss (NIHL) is an important occupational disorder. However, the molecular mechanisms underlying NIHL have not been fully clarified; therefore, the condition lacks effective therapeutic methods. Cyclooxygenase-2 (Cox-2) is an inducible enzyme involved in the synthesis of prostaglandins, and has been implicated in many pathophysiological events, such as oxidative stress and inflammation. In this study, we investigated the possible role of Cox-2 in the mechanisms of NIHL and the therapeutic effect of the Cox-2 inhibitor NS398 on NIHL using a mouse model. We demonstrated that Cox-2 is constitutively expressed in the mouse cochlea, and its expression could be dramatically up-regulated by high levels of noise exposure. Furthermore, we demonstrated that pre-treatment with the Cox-2 inhibitor NS398 could inhibit Cox-2 expression during noise overstimulation; and could attenuate noise-induced hearing loss and hair cell damage. Our results suggest that Cox-2 is involved in the pathogenesis of NIHL; and pharmacological inhibition of Cox-2 has considerable therapeutic potential in NIHL. PMID:26934825

  16. Inhibition of cyclooxygenase-2 impacts chondrocyte hypertrophic differentiation during endochondral ossification.

    PubMed

    Welting, T J M; Caron, M M J; Emans, P J; Janssen, M P F; Sanen, K; Coolsen, M M E; Voss, L; Surtel, D A M; Cremers, A; Voncken, J W; van Rhijn, L W

    2011-01-01

    Skeletogenesis and bone fracture healing involve endochondral ossification, a process during which cartilaginous primordia are gradually replaced by bone tissue. In line with a role for cyclooxygenase-2 (COX-2) in the endochondral ossification process, non-steroidal anti-inflammatory drugs (NSAIDs) were reported to negatively affect bone fracture healing due to impaired osteogenesis. However, a role for COX-2 activity in the chondrogenic phase of endochondral ossification has not been addressed before. We show that COX-2 activity fulfils an important regulatory function in chondrocyte hypertrophic differentiation. Our data reveal essential cross-talk between COX-2 and bone morphogenic protein-2 (BMP-2) during chondrocyte hypertrophic differentiation. BMP-2 mediated chondrocyte hypertrophy is associated with increased COX-2 expression and pharmacological inhibition of COX-2 activity by NSAIDs (e.g., Celecoxib) decreases hypertrophic differentiation in various chondrogenic models in vitro and in vivo, while leaving early chondrogenic development unaltered. Our findings demonstrate that COX-2 activity is a novel factor partaking in chondrocyte hypertrophy in the context of endochondral ossification and these observations provide a novel etiological perspective on the adverse effects of NSAIDs on bone fracture healing and have important implications for the use of NSAIDs during endochondral skeletal development. PMID:22183916

  17. Zoledronic acid cooperates with a cyclooxygenase-2 inhibitor and gefitinib in inhibiting breast and prostate cancer.

    PubMed

    Melisi, Davide; Caputo, Rosa; Damiano, Vincenzo; Bianco, Roberto; Veneziani, Bianca Maria; Bianco, A Raffaele; De Placido, Sabino; Ciardiello, Fortunato; Tortora, Giampaolo

    2005-12-01

    Biphosphonates (BPs) are widely used to inhibit osteoclastic activity in malignant diseases such as bone metastatic breast and prostate carcinoma. Recent studies reported that BPs could also cause a direct antitumor effect, probably due to their ability to interfere with several intracellular signalling molecules. The enzyme cyclooxygenase-2 (COX-2) and the epidermal growth factor receptor (EGFR) play an important role in the control of cancer cell growth and inhibitors of COX-2 and EGFR have shown antitumor activity in vitro and in vivo in several tumor types. We, and others, have previously shown that EGFR and COX-2 may be directly related to each other and that their selective inhibitors may have a cooperative effect. In the present study we have evaluated the combined effect of zoledronic acid, the most potent nitrogen-containing BP, with the COX-2 inhibitor SC-236 and the selective EGFR-tyrosine kinase inhibitor gefitinib, on breast and prostate cancer models in vitro and in xenografted nude mice. We show that combination of zoledronic acid with SC-236 and gefitinib causes a cooperative antitumor effect accompanied by induction of apoptosis and regulation of the expression of mitogenic factors, proangiogenic factors and cell cycle controllers both in vitro and in xenografted nude mice. The modulatory effect on protein expression and the inhibitory effect on tumor growth is much more potent when the three agents are used together. Since studies are ongoing to explore the antitumor effect of zoledronic acid, our results provide new insights into the mechanism of action of these agents and a novel rationale to translate this feasible combination treatment strategy into a clinical setting.

  18. Novel anti-inflammatory chalcone derivatives inhibit the induction of nitric oxide synthase and cyclooxygenase-2 in mouse peritoneal macrophages.

    PubMed

    Herencia, F; Ferrándiz, M L; Ubeda, A; Guillén, I; Dominguez, J N; Charris, J E; Lobo, G M; Alcaraz, M J

    1999-06-18

    In a previous work, we tested a series of chalcone derivatives as possible anti-inflammatory compounds. We now investigate the effects of three of those compounds, CHI, CH8 and CH12, on nitric oxide and prostanoid generation in mouse peritoneal macrophages stimulated with lipopolysaccharide and in the mouse air pouch injected with zymosan, where they showed a dose-dependent inhibition with inhibitory concentration 50% values in the microM range. This effect was not the consequence of a direct inhibitory action on enzyme activities. Our results demonstrated that chalcone derivatives inhibited de novo inducible nitric oxide synthase and cyclooxygenase-2 synthesis, being a novel therapeutic approach for inflammatory diseases.

  19. Delphinidin suppresses ultraviolet B-induced cyclooxygenases-2 expression through inhibition of MAPKK4 and PI-3 kinase.

    PubMed

    Kwon, Jung Yeon; Lee, Ki Won; Kim, Jong-Eun; Jung, Sung Keun; Kang, Nam Joo; Hwang, Mun Kyung; Heo, Yong-Seok; Bode, Ann M; Dong, Zigang; Lee, Hyong Joo

    2009-11-01

    Cyclooxygenase-2 (COX-2), a key mediator of inflammation, and its product, prostaglandin E(2) (PGE(2)), enhance carcinogenesis, particularly in skin. Ultraviolet (UV) B is the most carcinogenic component of solar irradiation, and a crucial role of COX-2 in UVB-mediated skin carcinogenesis has been reported. Here, we investigated the effects of delphinidin, an abundant dietary anthocyanin, on UVB-induced COX-2 upregulation and the underlying molecular mechanism. We found that delphinidin suppressed UVB-induced COX-2 expression in JB6 P+ mouse epidermal cells. COX-2 promoter activity and PGE(2) production were also suppressed by delphinidin treatment within non-cytotoxic concentrations. Activator protein-1 and nuclear factor-kappaB, crucial transcription factors involved in COX-2 expression, were activated by UVB and delphinidin abolished this activation. UVB-induced phosphorylation of c-Jun N-terminal kinase, p38 kinase and Akt was inhibited by delphinidin. The activities of mitogen-activated protein kinase kinase (MAPKK) 4 and phosphatidylinositol-3 kinase (PI-3K) were inhibited markedly by delphinidin. A pull-down assay using delphinidin-Sepharose beads revealed that delphinidin binds directly with MAPKK4 or PI-3K in a manner that was competitive with adenosine triphosphate. Moreover, in vivo investigations using mouse skin revealed that the upregulation of COX-2 expression, MAPKK4 activity and PI-3K activity induced by UVB was abolished with delphinidin treatment. Collectively, our results demonstrated that delphinidin targets MAPKK4 and PI-3K directly to suppress COX-2 overexpression, suggesting a potential protective role for delphinidin against UVB-mediated skin carcinogenesis.

  20. Cyclooxygenase-2 (COX-2) mediates arsenite inhibition of UVB-induced cellular apoptosis in mouse epidermal Cl41 cells.

    PubMed

    Zuo, Z; Ouyang, W; Li, J; Costa, M; Huang, C

    2012-07-01

    Inorganic arsenic is an environmental human carcinogen, and has been shown to act as a co-carcinogen with solar ultraviolet (UV) radiation in mouse skin tumor induction even at low concentrations. However, the precise mechanism of its co-carcinogenic action is largely unknown. Apoptosis plays an essential role as a protective mechanism against neoplastic development in the organism by eliminating genetically damaged cells. Thus, suppression of apoptosis is thought to contribute to carcinogenesis. It is known that cyclooxygenase-2 (COX-2) can promote carcinogenesis by inhibiting cell apoptosis under stress conditions; and our current studies investigated the potential contribution of COX-2 to the inhibitory effect of arsenite in UV-induced cell apoptosis in mouse epidermal Cl41 cells. We found that treatment of cells with low concentration (5 μM) arsenite attenuated cellular apoptosis upon UVB radiation accompanied with a coinductive effect on COX-2 expression and nuclear factor-κB (NFκB) transactivation. Our results also showed that the COX-2 induction by arsenite and UVB depended on an NFκB pathway because COX-2 co-induction could be attenuated in either p65-deficient or p50-deficient cells. Moreover, UVB-induced cell apoptosis could be dramatically reduced by the introduction of exogenous COX-2 expression, whereas the inhibitory effect of arsenite on UVB-induced cell apoptosis could be impaired in COX-2 knockdown C141 cells. Our results indicated that COX-2 mediated the anti-apoptotic effect of arsenite in UVB radiation through an NFκB-dependent pathway. Given the importance of apoptosis evasion during carcinogenesis, we anticipated that COX-2 induction might be at least partially responsible for the co-carcinogenic effect of arsenite on UVB-induced skin carcinogenesis.

  1. Naturally occurring biflavonoid, ochnaflavone, inhibits cyclooxygenases-2 and 5-lipoxygenase in mouse bone marrow-derived mast cells.

    PubMed

    Son, Min Jung; Moon, Tae Chul; Lee, Eun Kyung; Son, Kun Ho; Kim, Hyun Pyo; Kang, Sam Sik; Son, Jong Keun; Lee, Seung Ho; Chang, Hyeun Wook

    2006-04-01

    Ochnaflavone is a medicinal herbal product isolated from Lonicera japonica that inhibits cyclooxygenase-2 (COX-2) dependent phases of prostaglandin D2 (PGD2) generation in bone marrow-derived mast cells (BMMC) in a concentration-dependent manner with IC50 values of 0.6 microM. Western blotting probed with specific anti-COX-2 antibodies showed that the decrease in quantity of the PGD2 product was accompanied by a decrease in the COX-2 protein level. In addition, this compound consistently inhibited the production of leukotriene C4 (LTC4) in a dose dependent manner, with an IC50 value of 6.56 microM. These results demonstrate that ochnaflavone has a dual cyclooxygenase-2/5-lipoxygenase inhibitory activity. Furthermore, this compound strongly inhibited degranulation reaction in a dose dependent manner, with an IC50 value of 3.01 microM. Therefore, this compound might provide a basis for novel anti-inflammatory drugs.

  2. Cyclooxygenase-2 inhibition improves amyloid-β-mediated suppression of memory and synaptic plasticity

    PubMed Central

    Kotilinek, Linda A.; Westerman, Marcus A.; Wang, Qinwen; Panizzon, Kimberly; Lim, Giselle P.; Simonyi, Agnes; Lesne, Sylvain; Falinska, Agnieszka; Younkin, Linda H.; Younkin, Steven G.; Rowan, Michael; Cleary, James; Wallis, Roi Ann; Sun, GraceY.; Cole, Greg; Frautschy, Sally; Anwyl, Roger; Ashe, Karen H.

    2008-01-01

    Non-steroidal anti-inflammatory agents (NSAIDs) are associated with a marked reduction in the risk of developing Alzheimer’s disease, a form of dementia characterized by the accumulation of amyloid plaques containing the amyloid-β protein (Aβ). Studies of the effects of NSAIDs upon the inflammatory response surrounding amyloid plaques and upon the generation of Aβ from the amyloid precursor protein (APP) have led to two proposed mechanisms by which NSAIDs may protect against Alzheimer’s disease: one, the selective lowering of Aβ42 by a subset of NSAIDs; and two, the reduction of inflammation. Although Alzheimer’s disease is a disorder of brain and synaptic function, the effects of NSAIDs on Aβ-mediated suppression of synaptic plasticity and memory function have never been reported. We therefore investigated how three different NSAIDs, chosen for their distinct effects on Aβ42 production and the inhibition of the cyclooxygenase (COX) isoenzymes, COX-1 and COX-2, affect memory function and synaptic plasticity. By focusing upon brain and synapse function, we made novel observations about the effects of NSAIDs on Aβ-mediated neural processes. Here we report that the selective inhibition of COX-2, but not COX-1, acutely prevented the suppression of hippocampal long-term plasticity (LTP) by Aβ. The non-selective NSAIDs, ibuprofen and naproxen, and a selective COX-2 inhibitor, MF-tricyclic, each restored memory function in Tg2576 mice over-expressing APP, and also blocked Aβ-mediated inhibition of LTP. There was no advantage of ibuprofen, a selective Aβ42-lowering agent (SALA), over the non-SALAs, naproxen and MF-tricyclic. The beneficial effects on memory did not depend upon lowered levels of Aβ42 or the inflammatory cytokines, tumour necrosis factor α (TNF-α) and interleukin 1β (IL-1β). Intriguingly, improved memory function was inversely related to prostaglandin E2 (PGE2) levels. Conversely, exogenous PGE2 prevented the restorative effects of COX-2

  3. Inhibition of Nuclear Factor κB Activation and Cyclooxygenase-2 Expression by Aqueous Extracts of Hispanic Medicinal Herbs

    PubMed Central

    Gonzales, Amanda M.; Hunsaker, Lucy A.; Franco, Carolina R.; Royer, Robert E.; Vander Jagt, David L.; Vander Jagt, Dorothy J.

    2010-01-01

    Abstract Nonsteroidal anti-inflammatory drugs (NSAIDs) are a primary choice of therapy for diseases with a chronic inflammatory component. Unfortunately, long-term NSAID therapy is often accompanied by severe side effects, including cardiovascular and gastrointestinal complications. Because of this, there is critical need for identification of new and safer treatments for chronic inflammation to circumvent these side effects. Inflammatory diseases have been successfully remedied with natural herbs by many cultures. To better understand the potential of natural herbs in treating chronic inflammation and to identify their mechanism of action, we have evaluated the anti-inflammatory activities of 20 medicinal herbs commonly used in the Hispanic culture. We have established a standardized method for preparing aqueous extracts (teas) from the selected medicinal herbs and screened for inhibition of tumor necrosis factor-α-induced activation of nuclear factor κB (NF-κB), which is the central signaling pathway of the inflammatory response. A number of herbal teas were identified that exhibited significant anti-inflammatory activity. In particular, tea from the herb commonly called laurel was found to be an especially potent inhibitor of NF-κB-dependent cyclooxygenase-2 gene expression and prostaglandin E2 production in cultured murine macrophages. These findings indicate that laurel tea extract contains potent anti-inflammatory compounds that function by inhibiting the major signal transduction pathway responsible for inducing an inflammatory event. Based on these results, laurel may represent a new, safe therapeutic agent for managing chronic inflammation. PMID:20482259

  4. Effects of specific inhibition of cyclooxygenase-2 on sodium balance, hemodynamics, and vasoactive eicosanoids.

    PubMed

    Catella-Lawson, F; McAdam, B; Morrison, B W; Kapoor, S; Kujubu, D; Antes, L; Lasseter, K C; Quan, H; Gertz, B J; FitzGerald, G A

    1999-05-01

    Conventional nonsteroidal anti-inflammatory drugs inhibit both cyclooxygenase (Cox) isoforms (Cox-1 and Cox-2) and may be associated with nephrotoxicity. The present study was undertaken to assess the renal effects of the specific Cox-2 inhibitor, MK-966. Healthy older adults (n = 36) were admitted to a clinical research unit, placed on a fixed sodium intake, and randomized under double-blind conditions to receive the specific Cox-2 inhibitor, MK-966 (50 mg every day), a nonspecific Cox-1/Cox-2 inhibitor, indomethacin (50 mg t.i.d.), or placebo for 2 weeks. All treatments were well tolerated. Both active regimens were associated with a transient but significant decline in urinary sodium excretion during the first 72 h of treatment. Blood pressure and body weight did not change significantly in any group. The glomerular filtration rate (GFR) was decreased by indomethacin but was not changed significantly by MK-966 treatment. Thromboxane biosynthesis by platelets was inhibited by indomethacin only. The urinary excretion of the prostacyclin metabolite 2,3-dinor-6-keto prostaglandin F1alpha was decreased by both MK-966 and indomethacin and was unchanged by placebo. Cox-2 may play a role in the systemic biosynthesis of prostacyclin in healthy humans. Selective inhibition of Cox-2 by MK-966 caused a clinically insignificant and transient retention of sodium, but no depression of GFR. Inhibition of both Cox isoforms by indomethacin caused transient sodium retention and a decline in GFR. Our data suggest that acute sodium retention by nonsteroidal anti-inflammatory drugs in healthy elderly subjects is mediated by the inhibition of Cox-2, whereas depression of GFR is due to inhibition of Cox-1.

  5. Rutin inhibits B[a]PDE-induced cyclooxygenase-2 expression by targeting EGFR kinase activity.

    PubMed

    Choi, Seunghwan; Lim, Tae-Gyu; Hwang, Mun Kyung; Kim, Yoon-A; Kim, Jiyoung; Kang, Nam Joo; Jang, Tae Su; Park, Jun-Seong; Yeom, Myeong Hun; Lee, Ki Won

    2013-11-15

    Rutin is a well-known flavonoid that exists in various natural sources. Accumulative studies have represented the biological effects of rutin, such as anti-oxidative and anti-inflammatory effects. However, the underlying mechanisms of rutin and its direct targets are not understood. We investigated whether rutin reduced B[a]PDE-induced-COX-2 expression. The transactivation of AP-1 and NF-κB were inhibited by rutin. Rutin also attenuated B[a]PDE-induced Raf/MEK/ERK and Akt activation, but had no effect on the phosphorylation of EGFR. An in vitro kinase assay revealed rutin suppressed EGFR kinase activity. We also confirmed direct binding between rutin and EGFR, and found that the binding was regressed by ATP. The EGFR inhibitor also inhibited the B[a]PDE-induced MEK/ERK and Akt signaling pathways and subsequently, suppressed COX-2 expression and promoter activity, in addition to suppressing the transactivation of AP-1 and NF-κB. In EGFR(-/-)mouse embryonic fibroblast cells, B[a]PDE-induced COX-2 expression was also diminished. Collectively, rutin inhibits B[a]PDE-induced COX-2 expression by suppressing the Raf/MEK/ERK and Akt signaling pathways. EGFR appeared to be the direct target of rutin.

  6. Viscum album Exerts Anti-Inflammatory Effect by Selectively Inhibiting Cytokine-Induced Expression of Cyclooxygenase-2

    PubMed Central

    Hegde, Pushpa; Maddur, Mohan S.; Friboulet, Alain; Bayry, Jagadeesh; Kaveri, Srini V.

    2011-01-01

    Viscum album (VA) preparations are extensively used as complementary therapy in cancer and are shown to exert anti-tumor activities which involve the cytotoxic properties, induction of apoptosis, inhibition of angiogenesis and several other immunomodulatory mechanisms. In addition to their application in cancer therapy, VA preparations have also been successfully utilized in the treatment of several inflammatory pathologies. Owing to the intricate association of inflammation and cancer and in view of the fact that several anti-tumor phytotherapeutics also exert a potent anti-inflammatory effect, we hypothesized that VA exerts an anti-inflammatory effect that is responsible for its therapeutic benefit. Since, inflammatory cytokine-induced cyclo-oxygenase-2 (COX-2) and prostaglandin E2 (PGE2) play a critical role in the pathogenesis of inflammatory diseases, we investigated the anti-inflammatory effect of VA on regulation of cyclo-oxygenase expression and PGE2 biosynthesis by using human lung adenocarcinoma cells (A549 cells) as a model. A549 cells were stimulated with IL-1β and treated with VA preparation (VA Qu Spez) for 18 hours. PGE2 was analysed in the culture supernatants by enzyme immunoassay. Expression of COX-2 and COX-1 proteins was analyzed by immunoblotting and the expression of COX-2 mRNA was assessed by semi-quantitative RT-PCR. We found that VA Qu Spez inhibit the secretion of IL-1β-induced PGE2 in a dose-dependent manner. Further, we also show that this inhibitory action was associated with a reduced expression of COX-2 without modulating the COX-1 expression. Together these results demonstrate a novel anti-inflammatory mechanism of action of VA preparations wherein VA exerts an anti-inflammatory effect by inhibiting cytokine-induced PGE2 via selective inhibition of COX-2. PMID:22028854

  7. Cyclooxygenase-2 inhibition does not impair block bone grafts healing in rabbit model.

    PubMed

    Moreschi, Eduardo; Biguetti, Claudia Cristina; Comparim, Eliston; De Andrade Holgado, Leandro; Ribeiro-Junior, Paulo Domingos; Nary-Filho, Hugo; Matsumoto, Mariza Akemi

    2013-12-01

    Success of alveolar reconstructions using onlay autogenous block bone grafts depends on their adequate integration to the recipient bed influenced by a number of local molecules. Considering the fundamental role of cyclooxygenase (COX-2) in bone repair, the aim of this study was to analyze the effect of its inhibition in the integration of endochondral (EC) iliac crest, and intramembranous (IM) calvaria bone grafts. Thirty-two rabbits were divided into 4 groups: Calvaria Control (CC) and Iliac Control--treated with oral 0.9 % saline solution, and Calvarial-NSAID (C-NSAID) and Iliac-NSAID (I-NSAID) groups--treated with oral 6 mg/Kg non-steroidal anti-inflammatory drug etoricoxib. After 7, 14, 30 and 60 days the animals were euthanized and the specimens removed for histological, histomorphometric and immunohistochemistry analysis. At day 60, a tight integration of IM blocks could be seen with the presence of remodeling bone, whereas integration of EC grafts was mainly observed at the edges of the grafts. A significant higher percentage of bone matrix in the interface region of the CC grafts in comparison to C-NSAID only at day 14, whereas no differences were detected comparing the EC grafts. No differences were observed in Runx-2 and vascular endothelial growth factor (VEGF) immunolabeling when comparing CC and C-NSAID groups, while a significant weaker Runx-2 and VEGF labeling was detected in I-NSAID group at day 60. Although some influence was detected in osteogenesis, it is concluded that drug induced inhibition of COX-2 does not impair onlay bone grafts' healing of both embryologic origins in rabbits. PMID:23783533

  8. Simultaneous Inhibition of EGFR/VEGFR and Cyclooxygenase-2 Targets Stemness-Related Pathways in Colorectal Cancer Cells

    PubMed Central

    Valverde, Araceli; Peñarando, Jon; Cañas, Amanda; López-Sánchez, Laura M.; Conde, Francisco; Hernández, Vanessa; Peralbo, Esther; López-Pedrera, Chary; de la Haba-Rodríguez, Juan; Aranda, Enrique; Rodríguez-Ariza, Antonio

    2015-01-01

    Despite the demonstrated benefits of anti-EGFR/VEGF targeted therapies in metastatic colorectal cancer (mCRC), many patients initially respond, but then show evidence of disease progression. New therapeutic strategies are needed to make the action of available drugs more efficient. Our study aimed to explore whether simultaneous targeting of EGFR/VEGF and cyclooxygenase-2 (COX-2) may aid the treatment and management of mCRC patients. The dual tyrosine kinase inhibitor AEE788 and celecoxib were used to inhibit EGFR/VEGFR and COX-2, respectively, in colorectal cancer cells. COX-2 inhibition with celecoxib augmented the antitumoral and antiangiogenic efficacy of AEE788, as indicated by the inhibition of cell proliferation, induction of apoptosis and G1 cell cycle arrest, down-regulation of VEGF production by cancer cells and reduction of cell migration. These effects were related with a blockade in the EGFR/VEGFR signaling axis. Notably, the combined AEE788/celecoxib treatment prevented β-catenin nuclear accumulation in tumor cells. This effect was associated with a significant downregulation of FOXM1 protein levels and an impairment in the interaction of this transcription factor with β-catenin, which is required for its nuclear localization. Furthermore, the combined treatment also reduced the expression of the stem cell markers Oct 3/4, Nanog, Sox-2 and Snail in cancer cells, and contributed to the diminution of the CSC subpopulation, as indicated by colonosphere formation assays. In conclusion, the combined treatment of AEE788 and celecoxib not only demonstrated enhanced anti-tumoral efficacy in colorectal cancer cells, but also reduced colon CSCs subpopulation by targeting stemness-related pathways. Therefore, the simultaneous targeting of EGFR/VEGF and COX-2 may aid in blocking mCRC progression and improve the efficacy of existing therapies in colorectal cancer. PMID:26107817

  9. Guggulsterone of Commiphora mukul resin reverses drug resistance in imatinib-resistant leukemic cells by inhibiting cyclooxygenase-2 and P-glycoprotein.

    PubMed

    Xu, Hong-Bin; Xu, Lu-Zhong; Mao, Xia-Ping; Fu, Jun

    2014-06-15

    The purpose of this study was to investigate the effects of guggulsterone on cyclooxygenase-2 and P-glycoprotein mediated drug resistance in imatinib-resistant K562 cells (K562/IMA). MTT cytotoxicity assay, flow cytometry, western blot analysis, and ELISA were performed to investigate the anti-proliferative effect, the reversal action of drug resistance, and the inhibitory effect on cyclooxygenase-2, P-glycoprotein, BCR/ABL kinase, and PGE2 release in K562/IMA cells by guggulsterone. The results showed that co-administration of guggulsterone resulted in a significant increase in chemo-sensitivity of K562/IMA cells to imatinib, compared with imatinib treatment alone. Rhodamine123 accumulation in K562/IMA cells was significantly enhanced after incubation with guggulsterone (60, 120 μM), compared with untreated K562/IMA cells (p<0.05). When imatinib (1 μM) was combined with guggulsterone (60, 120 μM), the mean apoptotic population of K562/IMA cells was 15.47% and 24.91%. It was increased by 3.82 and 6.79 times, compared with imatinib (1 μM) treatment alone. Furthermore, guggulsterone had significantly inhibitory effects on the levels of cyclooxygenase-2, P-glycoprotein and prostaglandin E2. However, guggulsterone had little inhibitory effect on the activity of BCR/ABL kinase. The present study indicates guggulsterone induces apoptosis by inhibiting cyclooxygenase-2 and down-regulating P-glycoprotein expression in K562/IMA cells.

  10. Cyclooxygenase-2 impairs treatment effects of radiotherapy for cervical cancer by inhibition of radiation-induced apoptosis

    SciTech Connect

    Ishikawa, Hitoshi . E-mail: hisikawa@med.gunma-u.ac.jp; Ohno, Tatsuya; Kato, Shingo; Wakatsuki, Masaru; Iwakawa, Mayumi; Ohta, Toshie M.S.; Imai, Takashi; Mitsuhashi, Norio; Noda, Shin-ei; Nakano, Takashi; Tsujii, Hirohiko

    2006-12-01

    Purpose: Cyclooxygenase-2 (COX-2) plays a pivotal role in regulation of radiation-induced apoptosis. The aim of this study was to analyze the relationship between COX-2 expression and postradiotherapy outcomes of patients with cervical cancer. Methods and Materials: Biopsy specimens from 47 consecutive patients who had undergone definitive radiotherapy alone or radiotherapy combined with chemotherapy between October 2002 and November 2004 were investigated. Results: The COX-2 expression rate of the pretreatment samples was 46.1% {+-} 21.0%, and the apoptotic index (AI) 1 week after start of radiotherapy was 2.1% {+-} 0.9%. There was a significant negative correlation between the pretreatment COX-2 expression and the AI during radiotherapy (r = -0.52, p = 0.0002). Complete response rates were 59% for COX-2-positive patients compared with 80% for COX-2-negative patients (p = 0.12). The 2-year local control rate for COX-2-positive patients was 71.3%, whereas the corresponding rate for COX-2-negative patients was 96.0% (p 0.06). Conclusions: To the best of our knowledge, this is the first report to prove clinically that COX-2 can make cervical squamous cell carcinomas more refractory to radiotherapy by inhibition of radiation-induced apoptosis. Furthermore, expression of COX-2 may be a good indicator to predict local tumor control after radiotherapy. Although long-term results are ultimately needed, the combination therapy of radiotherapy with use of a COX-2 inhibitor could yield improved outcomes for patients with COX-2 expressing cervical cancer.

  11. Meso-dihydroguaiaretic acid isolated from Saururus chinensis inhibits cyclooxygenase-2 and 5-lipoxygenase in mouse bone marrow-derived mast cells.

    PubMed

    Moon, Tae Chul; Seo, Chang Seob; Haa, Kyungmi; Kim, Jin Cheul; Hwang, Nam Kyung; Hong, Tae Gyun; Kim, Jee Hyeun; Kim, Do Hun; Son, Jong Keun; Chang, Hyeun Wook

    2008-05-01

    Meso-dihydroguaiaretic acid (MDGA) is a medicinal herbal product isolated from the aerial parts of Saururus chinensis that inhibits the cyclooxygenase-2 (COX-2)-dependent phase of prostaglandin D(2) (PGD(2)) generation in bone marrow-derived mast cells (BMMC) (IC(50) 9.8 microM). However, this compound did not inhibit COX-2 protein expression in BMMC at concentrations up to 30 microM, indicating that MDGA directly inhibits COX-2 activity. In addition, this compound consistently inhibited the production of leukotriene C(4) (IC(50) 1.3 microM). These results demonstrate that MDGA inhibits both COX-2 and 5-lipoxygenase. Furthermore, this compound strongly inhibited the degranulation reaction in BMMC (IC(50) 11.4 microM). Therefore, this compound might provide a basis for novel anti-inflammatory drug development.

  12. Lactoferrin from Camelus dromedarius Inhibits Nuclear Transcription Factor-kappa B Activation, Cyclooxygenase-2 Expression and Prostaglandin E2 Production in Stimulated Human Chondrocytes

    PubMed Central

    Rasheed, Naila; Alghasham, Abdullah; Rasheed, Zafar

    2016-01-01

    Background: Osteoarthritis (OA) is a progressive joint disorder, which remains the leading cause of chronic disability in aged people. Nuclear factor-kappa B (NF)-κB is a major cellular event in OA and its activation by interleukin-1β (IL-1β) plays a critical role in cartilage breakdown in these patients. Objective: In this study, we examined the effect of lactoferrin on NF-κB activation, cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production in stimulated human articular chondrocytes. Materials and Methods: Human chondrocytes were derived from OA articular cartilage and treated with camel lactoferrin and then stimulated with IL-1β. Gene expression was determined by TaqMan assays and protein expression was studied by Western immunoblotting. NF-κB activity and PGE2 levels were determined by ELISA based assays. NF-κB activity was also determined by treatment of chondrocytes with NF-κB specific inhibitor Bay 11–7082. Results: Lactoferrin inhibited IL-1β-induced activation and nuclear translocation of NF-κB p65 in human OA chondrocytes. Lactoferrin also inhibited mRNA/protein expression of COX-2 and production of PGE2. Moreover, Bay 11–7082 also inhibited IL-1β-induced expression of COX-2 and production of PGE2. The inhibitory effect of lactoferrin on the IL-1β induced expression of COX-2 or production of PGE2 was mediated at least in part via suppression of NF-κB activation. Conclusions: Our data determine camel lactoferrin as a novel inhibitor of IL-1β-induced activation of NF-κB signaling events and production of cartilage-degrading molecule PGE2 via inhibition of COX-2 expressions. These results may have important implications for the development of novel therapeutic strategies for the prevention/treatment of OA and other degenerative/inflammatory diseases. SUMMARY Lactoferrin shows anti-arthritic activity in IL-1β stimulated primary human chondrocytes.Lactoferrin inhibits IL-1β-induced NF-κB activation.Lactoferrin inhibits

  13. Anti-inflammatory mode of isoflavone glycoside sophoricoside by inhibition of interleukin-6 and cyclooxygenase-2 in inflammatory response.

    PubMed

    Kim, Byung Hak; Chung, Eun Yong; Ryu, Jae-Chun; Jung, Sang-Hun; Min, Kyung Rak; Kim, Youngsoo

    2003-04-01

    Soy, high dietary intake for the oriental population, is a main source of isoflavonoids. Sophoricoside (SOP) an isoflavone glycoside was isolated from immature fruits of Sophora japonica (Leguminosae family) and its inhibitory effect on chemical mediators involved in inflammatory response was investigated in this study. SOP inhibited the interleukin (IL)-6 bioactivity with an IC50 value of 6.1 microM whereas it had no effects on IL-1beta and TNF-alpha bioactivities. SOP was identified as a selective inhibitor of cyclooxygenase (COX)-2 activity with an IC50 value of 4.4 microM, but did not show inhibitory effect on the synthesis of COX-2. However, SOP had no effect on the production of reactive oxygen species including superoxide anions and nitric oxide. These results revealed that in vitro anti-inflammatory action of SOP is significantly different from that of genistein known as a phytoestrogen of soy products. This experimental study has documented an importance of dietary soy isoflavonoids as multifunctional agents beneficial to human health, and will help to clarify protective mechanisms of SOP against inflammatory conditions. PMID:12735689

  14. Harmine combined with paclitaxel inhibits tumor proliferation and induces apoptosis through down-regulation of cyclooxygenase-2 expression in gastric cancer

    PubMed Central

    Yu, Xiao-Juan; Sun, Kun; Tang, Xiao-He; Zhou, Cun-Jin; Sun, Hui; Yan, Zhe; Fang, Ling; Wu, Hong-Wen; Xie, Yi-Kui; Gu, Bin

    2016-01-01

    Cyclooxygenase-2 (COX-2) serves an important role in the carcinogenesis and progression of gastric cancer. Harmine (HM) and paclitaxel (PTX) are reported as promising drug candidates for cancer therapy, but whether a synergistic anti-tumor effect of HM combined with PTX exists in human gastric cancer remains unknown. The present study evaluated the effects of HM and/or PTX on cell proliferation and apoptosis in a gastric cancer cell line, SGC-7901. HM and PTX inhibited cell proliferation in a dose-dependent manner. Both HM and PTX alone induced apoptosis in gastric cancer cells. The combination of HM and PTX exerted synergistic effects on proliferation inhibition and apoptosis induction in SGC-7901 cells, with down-regulation of COX-2, PCNA and Bcl-2 and up-regulation of Bax expression. The results indicated that combination chemotherapy using HM with PTX exerts an anti-tumor effect for treating gastric cancer. The combination of the two drugs inhibits gastric cancer development more effectively than each drug alone through down-regulation of COX-2 expression. PMID:27446381

  15. Inhibitors of cyclooxygenase-2, but not cyclooxygenase-1 provide structural and functional protection against quinolinic acid-induced neurodegeneration.

    PubMed

    Salzberg-Brenhouse, Heather C; Chen, Er-Yun; Emerich, Dwaine F; Baldwin, Sam; Hogeland, Ken; Ranelli, Sharon; Lafreniere, Denise; Perdomo, Brigido; Novak, Leah; Kladis, Theodora; Fu, Karen; Basile, Anthony S; Kordower, Jeffrey H; Bartus, Raymond T

    2003-07-01

    Cyclooxygenases (COXs) are implicated in neurodegenerative processes associated with acute and chronic neurological diseases. Given the potential utility of COX inhibitors in treating these disorders, we examined the nonselective COX inhibitor flurbiprofen, the specific COX-1 inhibitor valeryl salicylate (VS), and the COX-2 inhibitor N-[2-(cyclohexyloxy)-4-nitrophenyl]methanesulfonamide (NS-398) for their abilities to protect striatal neurons against a quinolinic acid (QA)-induced excitotoxic lesion. Rats were administered COX inhibitors 10 min before a unilateral QA lesion of the striatum, and then tested 2 to 3 weeks later in a battery of motor tasks (bracing, placing, akinesia, and apomorphine-induced rotations). Lesion volume was assessed using immunohistochemical methods 1 month after lesioning. Orally administered flurbiprofen (50 mg) was highly neuroprotective, preserving 84 to 99% of motor performance (ED50 = 8.6-9.7 mg) while reducing lesion volume 75% (ED50 = 3.2 mg). The identities of the COX isoforms associated with QA-induced neurodegeneration were determined using VS and NS-398. Oral VS was ineffective in virtually all indices of functional neuroprotection. In contrast, oral NS-398 was highly effective, preserving approximately 83% of motor performance at2mg(ED50 = 0.1-0.4 mg), and reducing lesion volume 100% (ED50 = 0.4 mg). Similar results were obtained using inhaled flurbiprofen (2 mg), which preserved 88 to 100% of motor performance while reducing striatal lesion size 92%. These results demonstrate that COX-2 inhibition protects neurons from acute, excitotoxic neurodegeneration. Moreover, formulating a nonselective COX inhibitor into an inhalable preparation dramatically improves its potency in treating acute neuronal damage, a situation where the rapidity of drug delivery and onset of action is critical to clinical efficacy.

  16. Delivery of ursolic acid (UA) in polymeric nanoparticles effectively promotes the apoptosis of gastric cancer cells through enhanced inhibition of cyclooxygenase 2 (COX-2).

    PubMed

    Zhang, Hao; Li, Xiaolin; Ding, Jing; Xu, Huae; Dai, Xinzheng; Hou, Zhibo; Zhang, Kai; Sun, Kun; Sun, Weihao

    2013-01-30

    It has been demonstrated that ursolic acid (UA) could effectively induces apoptosis of cancer cells by inhibiting the expression of cyclooxygenase 2 (COX-2), which constitutively expresses in gastric cancer. However, the hydrophobicity of UA increases the difficulty in its potential clinical application, which raises the possibility for its application as a novel model drug in nanoparticle-based delivery system. UA-loaded nanoparticles (UA-NPs) were prepared by a nano-precipitation method using amphilic methoxy poly(ethylene glycol)-polycaprolactone (mPEG-PCL) block copolymers as drug carriers. UA was effectively transported into SGC7901 cells by nanoparticles and localized around the nuclei in the cytoplasms. The in vitro cytotoxicity and apoptosis test indicated that UA-NPs significantly elicited more cell death at almost equivalent dose and corresponding incubation time. Moreover, UA-NPs led to more cell apoptosis through stronger inhibition of COX-2 and activation of caspase 3. The most powerful evidence from this report is that the significant differences between the cytotoxicity of free UA and UA-NPs are closely related to the expression levels of COX-2 and caspase-3, which demonstrates the superiority of UA-NPs over free UA through penetrating cell membrane. Therefore, the study offer an effective way to improve the anticancer efficiency of UA through nano-drug delivery system.

  17. The effects of a cyclooxygenase-2 (COX-2) expression and inhibition on human uveal melanoma cell proliferation and macrophage nitric oxide production

    PubMed Central

    Marshall, Jean-Claude; Caissie, Amanda L; Cruess, Stephanie R; Cools-Lartigue, Jonathan; Burnier, Miguel N

    2007-01-01

    Background Cyclooxygenase-2 (COX-2) expression has previously been identified in uveal melanoma although the biological role of COX-2 in this intraocular malignancy has not been elucidated. This study aimed to investigate the effect of a COX-2 inhibitor on the proliferation rate of human uveal melanoma cells, as well as its effect on the cytotoxic response of macrophages. Methods Human uveal melanoma cell lines were transfected to constitutively express COX-2 and the proliferative rate of these cells using two different methods, with and without the addition of Amfenac, was measured. Nitric oxide production by macrophages was measured after exposure to melanoma-conditioned medium from both groups of cells as well as with and without Amfenac, the active metabolite of Nepafenac. Results Cells transfected to express COX-2 had a higher proliferation rate than those that did not. The addition of Amfenac significantly decreased the proliferation rate of all cell lines. Nitric oxide production by macrophages was inhibited by the addition of melanoma conditioned medium, the addition of Amfenac partially overcame this inhibition. Conclusion Amfenac affected both COX-2 transfected and non-transfected uveal melanoma cells in terms of their proliferation rates as well as their suppressive effects on macrophage cytotoxic activity. PMID:18042295

  18. Piperine inhibits PMA-induced cyclooxygenase-2 expression through downregulating NF-κB, C/EBP and AP-1 signaling pathways in murine macrophages.

    PubMed

    Kim, Hyung Gyun; Han, Eun Hee; Jang, Woo-Seok; Choi, Jae Ho; Khanal, Tilak; Park, Bong Hwan; Tran, Thu Phuong; Chung, Young Chul; Jeong, Hye Gwang

    2012-07-01

    Piperine is a major component of black (Piper nigrum Linn) and long (Piper longum Linn) peppers, and is widely used as a traditional food and medicine. It also exhibits a variety of biological activities, which include antioxidant, anti-tumor and anti-pyretic properties. In the present study, we investigated the inhibitory effects of piperine on phorbol 12-myristate 13-acetate (PMA)-induced cyclooxygenase-2 (COX-2) gene expression and analyzed the molecular mechanism of its activity in murine RAW 264.7 macrophages. Piperine dose-dependently decreased PMA-induced COX-2 expression and PGE(2) production, as well as COX-2 promoter-driven luciferase activity. Transient transfections utilizing COX-2 promoter deletion constructs and COX-2 promoter constructs, in which specific enhancer elements were mutagenized, revealed that the nuclear factor-κB (NF-κB), CCAAT/enhancer binding protein (C/EBP) and activator protein-1 (AP-1), were the predominant contributors to the effects of piperine. In addition, piperine inhibited PMA-induced NF-κB, C/EBP and c-Jun nuclear translocation. Furthermore, piperine significantly inhibited PMA-induced activation of the Akt and ERK. These findings demonstrate that piperine effectively attenuates COX-2 production, and provide further insight into the signal transduction pathways involved in the anti-inflammatory effects of piperine. PMID:22542552

  19. Dehydrodiisoeugenol, an isoeugenol dimer, inhibits lipopolysaccharide-stimulated nuclear factor kappa B activation and cyclooxygenase-2 expression in macrophages.

    PubMed

    Murakami, Yukio; Shoji, Masao; Hirata, Atsushi; Tanaka, Shoji; Yokoe, Ichiro; Fujisawa, Seiichiro

    2005-02-15

    o-Methoxyphenols such as eugenol and isoeugenol exhibit anti-oxidant and anti-inflammatory activities, but at higher concentrations act as oxidants and potent allergens. We recently demonstrated the eugenol dimer bis-eugenol to be an efficient inhibitor of lipopolysaccharide (LPS)-induced inflammatory cytokine expression in macrophages without cytotoxicity. This result suggested that dimer compound of o-methoxyphenols may possess anti-inflammatory activity. Thus, we further synthesized dehydrodiisoeugenol and alpha-diisoeugenol from isoeugenols, and investigated whether these dimers could inhibit LPS-stimulated nuclear factor kappa B (NF-kappaB) activation and cyclooxygenase (COX)-2 gene expression, both of which are closely involved in inflammation and mutagenesis. The expression of the COX-2 gene was strongly inhibited by dehydrodiisoeugenol in RAW264.7 murine macrophages stimulated with LPS. In contrast, isoeugenol and alpha-diisoeugenol did not inhibit it. Dehydrodiisoeugenol also significantly inhibited LPS-stimulated phosphorylation-dependent proteolysis of inhibitor kappaB-alpha and transcriptional activity of NF-kappaB in the cells. These findings suggest that dehydrodiisoeugenol acts as a potent anti-inflammatory agent.

  20. Pro-inflammatory enzymes, cyclooxygenase 1, cyclooxygenase 2, and 5-lipooxygenase, inhibited by stabilized rice bran extracts.

    PubMed

    Roschek, Bill; Fink, Ryan C; Li, Dan; McMichael, Matthew; Tower, Christine M; Smith, Robert D; Alberte, Randall S

    2009-06-01

    Rice bran, the outer bran and germ of the kernel and a by-product of rice milling, is rich in phytonutrients but has been underutilized because of lipid content instability. New methods for the processing of rice bran have yielded a stabilized form that is increasingly used in foods and dietary supplements. Recent studies have documented a role for stabilized rice bran (SRB) in treating diabetes and arthritis, although little is known of the bioactive compounds that impart these health benefits. Here we characterize the chemical composition of three extracts of SRB and identify the functional bioactives contributing to the inhibitory properties against three key pro-inflammatory enzymes (cyclooxygenase [COX] 1, COX2, and 5-lipoxygenase [5-LOX]) that control the inflammatory cascade involved in impaired joint health, pain, and arthritis. One extract (SRB-AI) demonstrated significant COX1 and COX2 inhibitory activities with 50% inhibitory concentration (IC(50)) values for COX1 and COX2 of 305 and 29 microg/mL, respectively, but no 5-LOX inhibition. The second extract (SRB-AII) inhibited COX1, COX2, and 5-LOX with IC(50) values of 310, 19, and 396 microg/mL, respectively. The third extract (SRB-AIII), a blend of SRB-AI and SRB-AIII, inhibited COX1, COX2, and 5-LOX with respective IC(50) values of 48, 11, and 197 microg/mL. Analysis of the extracts by direct analysis in real time time of flight-mass spectrometry revealed that SRB-AI, SRB-AII, and SRB-AIII contain over 620, 770, and 810 compounds, respectively. Of these, 17 were identified as key bioactives for COX and/or LOX inhibition. These SRB extracts have applications for functional foods and dietary supplements for control of inflammation and joint health.

  1. The Bitter Barricading of Prostaglandin Biosynthesis Pathway: Understanding the Molecular Mechanism of Selective Cyclooxygenase-2 Inhibition by Amarogentin, a Secoiridoid Glycoside from Swertia chirayita

    PubMed Central

    Sundar, Durai; Thorat, Sunil S.

    2014-01-01

    Swertia chirayita, a medicinal herb inhabiting the challenging terrains and high altitudes of the Himalayas, is a rich source of essential phytochemical isolates. Amarogentin, a bitter secoiridoid glycoside from S. chirayita, shows varied activity in several patho-physiological conditions, predominantly in leishmaniasis and carcinogenesis. Experimental analysis has revealed that amarogentin downregulates the cyclooxygenase-2 (COX-2) activity and helps to curtail skin carcinogenesis in mouse models; however, there exists no account on selective inhibition of the inducible cyclooxygenase (COX) isoform by amarogentin. Hence the computer-aided drug discovery methods were used to unravel the COX-2 inhibitory mechanism of amarogentin and to check its selectivity for the inducible isoform over the constitutive one. The generated theoretical models of both isoforms were subjected to molecular docking analysis with amarogentin and twenty-one other Food and Drug Authority (FDA) approved lead molecules. The post-docking binding energy profile of amarogentin was comparable to the binding energy profiles of the FDA approved selective COX-2 inhibitors. Subsequent molecular dynamics simulation analysis delineated the difference in the stability of both complexes, with amarogentin-COX-2 complex being more stable after 40ns simulation. The total binding free energy calculated by MMGBSA for the amarogentin-COX-2 complex was −52.35 KCal/mol against a binding free energy of −8.57 KCal/mol for amarogentin-COX-1 complex, suggesting a possible selective inhibition of the COX-2 protein by the natural inhibitor. Amarogentin achieves this potential selectivity by small, yet significant, structural differences inherent to the binding cavities of the two isoforms. Hypothetically, it might block the entry of the natural substrates in the hydrophobic binding channel of the COX-2, inhibiting the cyclooxygenation step. To sum up briefly, this work highlights the mechanism of the possible

  2. NO2 inhalation promotes Alzheimer’s disease-like progression: cyclooxygenase-2-derived prostaglandin E2 modulation and monoacylglycerol lipase inhibition-targeted medication

    PubMed Central

    Yan, Wei; Yun, Yang; Ku, Tingting; Li, Guangke; Sang, Nan

    2016-01-01

    Air pollution has been reported to be associated with increased risks of cognitive impairment and neurodegenerative diseases. Because NO2 is a typical primary air pollutant and an important contributor to secondary aerosols, NO2-induced neuronal functional abnormalities have attracted greater attention, but the available experimental evidence, modulating mechanisms, and targeting medications remain ambiguous. In this study, we exposed C57BL/6J and APP/PS1 mice to dynamic NO2 inhalation and found for the first time that NO2 inhalation caused deterioration of spatial learning and memory, aggravated amyloid β42 (Aβ42) accumulation, and promoted pathological abnormalities and cognitive defects related to Alzheimer’s disease (AD). The microarray and bioinformation data showed that the cyclooxygenase-2 (COX-2)-mediated arachidonic acid (AA) metabolism of prostaglandin E2 (PGE2) played a key role in modulating this aggravation. Furthermore, increasing endocannabinoid 2-arachidonoylglycerol (2-AG) by inhibiting monoacylglycerol lipase (MAGL) prevented PGE2 production, neuroinflammation-associated Aβ42 accumulation, and neurodegeneration, indicating a therapeutic target for relieving cognitive impairment caused by NO2 exposure. PMID:26928013

  3. Aqueous extract of the edible Gracilaria tenuistipitata inhibits hepatitis C viral replication via cyclooxygenase-2 suppression and reduces virus-induced inflammation.

    PubMed

    Chen, Kuan-Jen; Tseng, Chin-Kai; Chang, Fang-Rong; Yang, Jin-Iong; Yeh, Chi-Chen; Chen, Wei-Chun; Wu, Shou-Fang; Chang, Hsueh-Wei; Lee, Jin-Ching

    2013-01-01

    Hepatitis C virus (HCV) is an important human pathogen leading to hepatocellular carcinoma. Using an in vitro cell-based HCV replicon and JFH-1 infection system, we demonstrated that an aqueous extract of the seaweed Gracilaria tenuistipitata (AEGT) concentration-dependently inhibited HCV replication at nontoxic concentrations. AEGT synergistically enhanced interferon-α (IFN-α) anti-HCV activity in a combination treatment. We found that AEGT also significantly suppressed virus-induced cyclooxygenase-2 (COX-2) expression at promoter transactivation and protein levels. Notably, addition of exogenous COX-2 expression in AEGT-treated HCV replicon cells gradually abolished AEGT anti-HCV activity, suggesting that COX-2 down-regulation was responsible for AEGT antiviral effects. Furthermore, we highlighted the inhibitory effect of AEGT in HCV-induced pro-inflammatory gene expression such as the expression of tumour necrosis factor-α, interleukin-1β, inducible nitrite oxide synthase and COX-2 in a concentration-dependent manner to evaluate the potential therapeutic supplement in the management of patients with chronic HCV infections.

  4. NO2 inhalation promotes Alzheimer’s disease-like progression: cyclooxygenase-2-derived prostaglandin E2 modulation and monoacylglycerol lipase inhibition-targeted medication

    NASA Astrophysics Data System (ADS)

    Yan, Wei; Yun, Yang; Ku, Tingting; Li, Guangke; Sang, Nan

    2016-03-01

    Air pollution has been reported to be associated with increased risks of cognitive impairment and neurodegenerative diseases. Because NO2 is a typical primary air pollutant and an important contributor to secondary aerosols, NO2-induced neuronal functional abnormalities have attracted greater attention, but the available experimental evidence, modulating mechanisms, and targeting medications remain ambiguous. In this study, we exposed C57BL/6J and APP/PS1 mice to dynamic NO2 inhalation and found for the first time that NO2 inhalation caused deterioration of spatial learning and memory, aggravated amyloid β42 (Aβ42) accumulation, and promoted pathological abnormalities and cognitive defects related to Alzheimer’s disease (AD). The microarray and bioinformation data showed that the cyclooxygenase-2 (COX-2)-mediated arachidonic acid (AA) metabolism of prostaglandin E2 (PGE2) played a key role in modulating this aggravation. Furthermore, increasing endocannabinoid 2-arachidonoylglycerol (2-AG) by inhibiting monoacylglycerol lipase (MAGL) prevented PGE2 production, neuroinflammation-associated Aβ42 accumulation, and neurodegeneration, indicating a therapeutic target for relieving cognitive impairment caused by NO2 exposure.

  5. Differential inhibition of fracture healing by non-selective and cyclooxygenase-2 selective non-steroidal anti-inflammatory drugs.

    PubMed

    Gerstenfeld, Louis C; Thiede, Mark; Seibert, Karen; Mielke, Cindy; Phippard, Deborah; Svagr, Bohus; Cullinane, Dennis; Einhorn, Thomas A

    2003-07-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) specifically inhibit cyclooxygenase (COX) activity and are widely used as anti-arthritics, post-surgical analgesics, and for the relief of acute musculoskeletal pain. Recent studies suggest that non-specific NSAIDs, which inhibit both COX-1 and COX-2 isoforms, delay bone healing. The objectives of this study were 2-fold; first, to measure the relative changes in the normal expression of COX-1 and COX-2 mRNAs over a 42 day period of fracture healing and second, to compare the effects of a commonly used non-specific NSAID, ketorolac, with a COX-2 specific NSAID, Parecoxib (a pro-drug of valdecoxib), on this process. Simple, closed, transverse fractures were generated in femora of male Sprague-Dawley rats weighing approximately 450 g each. Total RNA was prepared from the calluses obtained prior to fracture and at 1, 3, 5, 7, 10, 14, 21, 35 and 42 days post-fracture and levels of COX-1 and COX-2 mRNA were measured using real time PCR. While the relative levels of COX-1 mRNA remained constant over a 21-day period, COX-2 mRNA levels showed peak expression during the first 14 days of healing and returned to basal levels by day 21. Mechanical properties of the calluses were then assessed at 21 and 35 days post-fracture in untreated animals and animals treated with either ketorolac or high or low dose parecoxib. At both 21 and 35 days after fracture, calluses in the group treated with the ketorolac showed a significant reduction in mechanical strength and stiffness when compared with controls (p<0.05). At the 21-day time point, calluses of the parecoxib treated animals showed a lower mean mechanical strength than controls, but the inhibition was not statistically significant. Based on physical analysis of the bones, 3 of 12 (25%) of the ketorolac-treated and 1 of 12 (8%) of the high dose parecoxib-treated animals showed failure to unite their fractures by 21 days, while all fractures in both groups showed union by 35 days

  6. Persistent cyclooxygenase-2 inhibition downregulates NF-{kappa}B, resulting in chronic intestinal inflammation in the min/+ mouse model of colon tumorigenesis.

    PubMed

    Carothers, Adelaide M; Davids, Jennifer S; Damas, Beatrice C; Bertagnolli, Monica M

    2010-06-01

    Cyclooxygenase-2 (COX-2) inhibition prevents adenoma formation in humans and mouse models of colon cancer. The selective COX-2 inhibitor celecoxib reduces COX-2 and prostaglandin E(2) (PGE(2)) expression and adenomas in the intestine of Min/+ mice after treatment for several weeks, but prolonged treatment increases PGE(2) production, resulting in drug-resistant tumor formation and transforming growth factor beta (TGFbeta)-dependent intestinal fibrosis. In this study, we examined pathways that regulate COX-2 expression and suppress chronic intestinal inflammation. We show that NF-kappaB signaling was inhibited in the ileum of Min/+ mice receiving long-term treatment with celecoxib. This effect was associated with inhibition of TGFbeta-associated kinase-1 and IkappaB kinase alpha/beta activities and reduced expression of the Toll-like receptor (TLR) 2 and TLR4 that enhance colonic barrier function. Additionally, we observed reduced activities of protein kinases c-Jun NH(2)-terminal kinase 1 and protein kinase A and transcription factor cyclic AMP-responsive element binding protein, regulators of COX-2 expression, which cross-talk with NF-kappaB. In ileum subjected to long-term celecoxib treatment, we noted relatively higher expression of COX-2, vascular endothelial growth factor, and interleukin-1beta in Paneth cells, whereas NF-kappaB and COX-2 were more strongly expressed by an expanded population of stromal myofibroblasts. Our findings argue that celecoxib resistance is an acquired adaptation to changes in the crypt microenvironment that is associated with chronic intestinal inflammation and impaired acute wound-healing responsiveness. PMID:20484034

  7. Isoform-selective interaction of cyclooxygenase-2 with indomethacin amides studied by real-time fluorescence, inhibition kinetics, and site-directed mutagenesis.

    PubMed

    Timofeevski, Sergei L; Prusakiewicz, Jeffery J; Rouzer, Carol A; Marnett, Lawrence J

    2002-07-30

    Conversion of carboxylate-containing nonsteroidal antiinflammatory drugs, such as indomethacin, to esters or amides provides potent and selective inhibitors of cyclooxygenase-2 (COX-2) [Kalgutkar et al. (2000) Proc. Natl. Acad. Sci. U.S.A. 97, 925-930]. Synthesis of cinnamyl- or coumarinyl-substituted ethanolamide derivatives of indomethacin produced fluorescent probes of inhibitor interaction with COX-2 and COX-1. Binding of either derivative to apoCOX-2 or apoCOX-1 resulted in a rapid, reversible enhancement of fluorescence. Following this rapid phase, a slow additional increase in fluorescence was observed with apoCOX-2 but not with apoCOX-1. The slow, COX-2-specific increase in fluorescence was prevented or reversed by addition of the nonfluorescent COX inhibitor (S)-flurbiprofen. Detailed kinetic studies of the interaction of the coumarinyl derivative with COX-2 showed that the observed changes in fluorescence could be described by two sequential equilibria, the first of which is rapid, reversible, and bimolecular in the forward direction. The second equilibrium is slower, reversible, and unimolecular in both directions. The forward rate constant for the slow equilibrium determined by fluorescence enhancement [(3.1 +/- 0.6) x 10(-3) s(-1)] corresponded closely to the forward rate constant for inhibition of COX-2 activity [(6.8 +/- 2.3) x 10(-3) s(-1)], suggesting that the slow fluorescence enhancement is associated with selective COX-2 inhibition. Site-directed mutagenesis indicated that residues in the carboxylate-binding region of the COX-2 active site (Arg-120, Tyr-355, and Glu-524) are critical for the binding of the indomethacin conjugates that leads to slow fluorescence enhancement and cyclooxygenase inhibition. The indomethacin conjugates described herein represent powerful tools for the investigation of a novel class of selective inhibitors of COX-2.

  8. Conservative Secondary Shell Substitution In Cyclooxygenase-2 Reduces Inhibition by Indomethacin Amides and Esters via Altered Enzyme Dynamics.

    PubMed

    Konkle, Mary E; Blobaum, Anna L; Moth, Christopher W; Prusakiewicz, Jeffery J; Xu, Shu; Ghebreselasie, Kebreab; Akingbade, Dapo; Jacobs, Aaron T; Rouzer, Carol A; Lybrand, Terry P; Marnett, Lawrence J

    2016-01-19

    The cyclooxygenase enzymes (COX-1 and COX-2) are the therapeutic targets of nonsteroidal anti-inflammatory drugs (NSAIDs). Neutralization of the carboxylic acid moiety of the NSAID indomethacin to an ester or amide functionality confers COX-2 selectivity, but the molecular basis for this selectivity has not been completely revealed through mutagenesis studies and/or X-ray crystallographic attempts. We expressed and assayed a number of divergent secondary shell COX-2 active site mutants and found that a COX-2 to COX-1 change at position 472 (Leu in COX-2, Met in COX-1) reduced the potency of enzyme inhibition by a series of COX-2-selective indomethacin amides and esters. In contrast, the potencies of indomethacin, arylacetic acid, propionic acid, and COX-2-selective diarylheterocycle inhibitors were either unaffected or only mildly affected by this mutation. Molecular dynamics simulations revealed identical equilibrium enzyme structures around residue 472; however, calculations indicated that the L472M mutation impacted local low-frequency dynamical COX constriction site motions by stabilizing the active site entrance and slowing constriction site dynamics. Kinetic analysis of inhibitor binding is consistent with the computational findings. PMID:26704937

  9. Novel di-tertiary-butyl phenylhydrazones as dual cyclooxygenase-2/5-lipoxygenase inhibitors: synthesis, COX/LOX inhibition, molecular modeling, and insights into their cytotoxicities.

    PubMed

    Ghatak, Shibnath; Vyas, Alok; Misra, Suniti; O'Brien, Paul; Zambre, Ajit; Fresco, Victor M; Markwald, Roger R; Swamy, K Venkateshwara; Afrasiabi, Zahra; Choudhury, Amitava; Khetmalas, Madhukar; Padhye, Subhash

    2014-01-01

    Although dual inhibition of Cyclooxygenase-2 (COX-2) and 5-Lipoxygenase (5-LOX) enzymes is highly effective than targeting COX or LOX alone, there are only a few reports of examining such compounds in case of colorectal cancers (CRC). In the present work we report that the novel di-tert-butyl phenol-based dual inhibitors DTPSAL, DTPBHZ, DTPINH, and DTPNHZ exhibit significant cytotoxicity against human CRC cell lines. Molecular docking studies revealed a good fit of these compounds in the COX-2 and 5-LOX protein cavities. The inhibitors show significant inhibition of COX-2 and 5-LOX activities and are effective against a panel of human colon cancer cell lines including HCA-7, HT-29, SW480 and intestinal Apc10.1 cells as well as the hyaluronan synthase-2 (Has2) enzyme over-expressing colon cancer cells, through inhibition of the Hyaluronan/CD44v6 cell survival pathway. Western blot analysis and qRT-PCR analyses indicated that the di-tert-butyl phenol-based dual inhibitors reduce the expression of COX-2, 5-LOX, and CD44v6 in human colon cancer HCA-7 cells, while the combination of CD44v6shRNA and DTPSAL has an additional inhibitory effect on CD44v6 mRNA expression. The synergistic inhibitory effect of Celecoxib and Licofelone on CD44v6 mRNA expression suggests that the present dual inhibitors down-regulate cyclooxygenase and lipoxygenase enzymes through CD44v6. The compounds also exhibited enhanced antiproliferative potency compared to standard dual COX/LOX inhibitor, viz. Licofelone. Importantly, the HA/CD44v6 antagonist CD44v6shRNA in combination with synthetic compounds had a sensitizing effect on the cancer cells which enhanced their antiproliferative potency, a finding which is crucial for the anti-proliferative potency of the novel synthetic di-tert-butyl phenol based dual COX-LOX inhibitors in colon cancer cells.

  10. Novel di-tertiary-butyl phenylhydrazones as dual cyclooxygenase-2/5-lipoxygenase inhibitors: synthesis, COX/LOX inhibition, molecular modeling, and insights into their cytotoxicities.

    PubMed

    Ghatak, Shibnath; Vyas, Alok; Misra, Suniti; O'Brien, Paul; Zambre, Ajit; Fresco, Victor M; Markwald, Roger R; Swamy, K Venkateshwara; Afrasiabi, Zahra; Choudhury, Amitava; Khetmalas, Madhukar; Padhye, Subhash

    2014-01-01

    Although dual inhibition of Cyclooxygenase-2 (COX-2) and 5-Lipoxygenase (5-LOX) enzymes is highly effective than targeting COX or LOX alone, there are only a few reports of examining such compounds in case of colorectal cancers (CRC). In the present work we report that the novel di-tert-butyl phenol-based dual inhibitors DTPSAL, DTPBHZ, DTPINH, and DTPNHZ exhibit significant cytotoxicity against human CRC cell lines. Molecular docking studies revealed a good fit of these compounds in the COX-2 and 5-LOX protein cavities. The inhibitors show significant inhibition of COX-2 and 5-LOX activities and are effective against a panel of human colon cancer cell lines including HCA-7, HT-29, SW480 and intestinal Apc10.1 cells as well as the hyaluronan synthase-2 (Has2) enzyme over-expressing colon cancer cells, through inhibition of the Hyaluronan/CD44v6 cell survival pathway. Western blot analysis and qRT-PCR analyses indicated that the di-tert-butyl phenol-based dual inhibitors reduce the expression of COX-2, 5-LOX, and CD44v6 in human colon cancer HCA-7 cells, while the combination of CD44v6shRNA and DTPSAL has an additional inhibitory effect on CD44v6 mRNA expression. The synergistic inhibitory effect of Celecoxib and Licofelone on CD44v6 mRNA expression suggests that the present dual inhibitors down-regulate cyclooxygenase and lipoxygenase enzymes through CD44v6. The compounds also exhibited enhanced antiproliferative potency compared to standard dual COX/LOX inhibitor, viz. Licofelone. Importantly, the HA/CD44v6 antagonist CD44v6shRNA in combination with synthetic compounds had a sensitizing effect on the cancer cells which enhanced their antiproliferative potency, a finding which is crucial for the anti-proliferative potency of the novel synthetic di-tert-butyl phenol based dual COX-LOX inhibitors in colon cancer cells. PMID:24295787

  11. MiR-26a and miR-144 inhibit proliferation and metastasis of esophageal squamous cell cancer by inhibiting cyclooxygenase-2

    PubMed Central

    Shao, Ying; Li, Peng; Zhu, Sheng-Tao; Yue, Ji-Ping; Ji, Xiao-Jun; Ma, Dan; Wang, Li; Wang, Yong-Jun; Zong, Ye; Wu, Yong-Dong; Zhang, Shu-Tian

    2016-01-01

    The altered expression of miRNAs is involved in carcinogenesis of esophageal squamous cell carcinoma (ESCC), but whether miRNAs regulate COX-2 expression in ESCC is not clear. To this end, the expression levels of miR-26a and miR-144 in ESCC clinical tissues and cell lines were investigated by qRT-PCR. COX-2 and PEG2 were quantified by western blot and ELISA. Decrease in miR-26a and miR-144 expression in ESCC was found by a comparison between 30 pairs of ESCC tumor and adjacent normal tissues as well as in 11 ESCC cell lines (P < 0.001). Co-transfection of miR-26a and miR-144 in ESCC cell lines more significantly suppressed cell proliferation, migration, and invasion than did either miR-26a or miR-144 alone (all P < 0.001), as shown by assays of CCK8, migration and invasion and flow cytometry. The inhibitory effect of these two miRNAs in vivo was also verified in nude mice xenograft models. COX-2 was confirmed as a target of miR-26a and miR-144. In conclusion, miR-26a and miR-144 expression is downregulated in ESCC. Co-expression of miR-26a and miR-144 in ESCC cells resulted in inhibition of proliferation and metastasis in vitro and in vivo, suggesting that targeting COX-2 may be the mechanism of these two miRNAs. PMID:26959737

  12. Opposing Effects of Cyclooxygenase-2 (COX-2) on Estrogen Receptor β (ERβ) Response to 5α-Reductase Inhibition in Prostate Epithelial Cells.

    PubMed

    Liu, Teresa T; Grubisha, Melanie J; Frahm, Krystle A; Wendell, Stacy G; Liu, Jiayan; Ricke, William A; Auchus, Richard J; DeFranco, Donald B

    2016-07-01

    Current pharmacotherapies for symptomatic benign prostatic hyperplasia (BPH), an androgen receptor-driven, inflammatory disorder affecting elderly men, include 5α-reductase (5AR) inhibitors (i.e. dutasteride and finasteride) to block the conversion of testosterone to the more potent androgen receptor ligand dihydrotestosterone. Because dihydrotestosterone is the precursor for estrogen receptor β (ERβ) ligands, 5AR inhibitors could potentially limit ERβ activation, which maintains prostate tissue homeostasis. We have uncovered signaling pathways in BPH-derived prostate epithelial cells (BPH-1) that are impacted by 5AR inhibition. The induction of apoptosis and repression of the cell adhesion protein E-cadherin by the 5AR inhibitor dutasteride requires both ERβ and TGFβ. Dutasteride also induces cyclooxygenase type 2 (COX-2), which functions in a negative feedback loop in TGFβ and ERβ signaling pathways as evidenced by the potentiation of apoptosis induced by dutasteride or finasteride upon pharmacological inhibition or shRNA-mediated ablation of COX-2. Concurrently, COX-2 positively impacts ERβ action through its effect on the expression of a number of steroidogenic enzymes in the ERβ ligand metabolic pathway. Therefore, effective combination pharmacotherapies, which have included non-steroidal anti-inflammatory drugs, must take into account biochemical pathways affected by 5AR inhibition and opposing effects of COX-2 on the tissue-protective action of ERβ. PMID:27226548

  13. An aqueous extract of Ilex paraguariensis reduces carrageenan-induced edema and inhibits the expression of cyclooxygenase-2 and inducible nitric oxide synthase in animal models of inflammation.

    PubMed

    Schinella, Guillermo; Neyret, Elisa; Cónsole, Gloria; Tournier, Horacio; Prieto, José M; Ríos, José-Luis; Giner, Rosa María

    2014-08-01

    Mate (Ilex paraguariensis) is a highly popular herbal beverage in South America due to its high content of caffeine. Its hypolipidemic and antioxidant properties are of increasing interest in the treatment of cardiovascular disorders and for weight control. In the present study, we show for the first time both the local and systemic anti-inflammatory effects of an aqueous extract of mate in three classic in vivo models, namely acute and chronic 12-O-tetradecanoylphorbol 13-acetate-induced mouse ear edema and acute carrageenan-induced mouse paw edema. Caffeine, rutin, chlorogenic acid, 3,5-dicafeoyl quinic acid, and 4,5-dicafeoyl quinic acid, accompanied by a complex mixture of other simple phenolic acids, were identified in the extract by HPLC-UV analyses. In the acute edema model, mate extract applied topically (1 mg/ear) halved the 12-O-tetradecanoylphorbol 13-acetate-induced acute edema (50 %) and almost suppressed neutrophil infiltration (93 %), while in the 12-O-tetradecanoylphorbol 13-acetate-induced subchronic inflammation, the edema was significantly reduced by 62 % (1 mg/ear/day × seven doses). The oral administration of the mate extract (250 mg/kg) significantly reduced the carrageenan-induced edema at all time points, an effect which was accompanied by a 43 % and 53 % reduction of the expression of cyclooxygenase-2 and inducible nitric oxide synthase, respectively. Histological analyses confirmed a reduction of epithelium thickness, dermis with mild inflammation, hair follicles with some secretory cells of sebaceous glands, and hypodermic adipocytes. In conclusion, mate is endowed with in vivo preventative or therapeutic anti-inflammatory effects in both local and systemic inflammatory processes.

  14. Manassantin B isolated from Saururus chinensis inhibits cyclooxygenase-2-dependent prostaglandin D2 generation by blocking Fyn-mediated nuclear factor-kappaB and mitogen activated protein kinase pathways in bone marrow derived-mast cells.

    PubMed

    Lu, Yue; Hwang, Seung-Lark; Son, Jong Keun; Chang, Hyeun Wook

    2013-01-01

    The authors investigated the effect of manassantin B (Man B) isolated from Saururus chinensis (S. chinensis) on cyclooxygenase-2 (COX-2)-dependent prostaglandin D2 (PGD2) generation in mouse bone marrow derived-mast cells (BMMCs). Man B inhibited the generation of PGD2 dose-dependently by inhibiting COX-2 expression in immunoglobulin E (IgE)/Ag-stimulated BMMCs. To elucidate the mechanism responsible for the inhibition of COX-2 expression by Man B, the effects of Man B on the activation of nuclear factor-kappaB (NF-κB), a transcription factor essential and mitogen-activated protein kinases (MAPKs) for COX-2 induction, were examined. Man B attenuated the nuclear translocation of NF-κB p65 and its DNA-binding activity by inhibiting inhibitors of kappa Bα (IκBα) degradation and concomitantly suppressing IκB kinase (IKK) phosphorylation. In addition, Man B suppressed phosphorylation of MAPKs including extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun NH2-terminal kinase (JNK) and p38. It was also found that Man B suppressed Fyn kinase activation and consequent downstream signaling processes, including those involving Syk, Gab2, and Akt. Taken together, the present results suggest that Man B suppresses COX-2 dependent PGD2 generation by primarily inhibiting Fyn kinase in FcεRI-mediated mast cells.

  15. Berberine, an isoquinoline alkaloid, inhibits melanoma cancer cell migration by reducing the expressions of cyclooxygenase-2, prostaglandin E2 and prostaglandin E2 receptors

    PubMed Central

    Singh, Tripti; Vaid, Mudit; Katiyar, Nandan; Sharma, Samriti; Katiyar, Santosh K.

    2011-01-01

    Melanoma is the leading cause of death from skin disease due, in large part, to its propensity to metastasize. We have examined the effect of berberine, an isoquinoline alkaloid, on human melanoma cancer cell migration and the molecular mechanisms underlying these effects using melanoma cell lines, A375 and Hs294. Using an in vitro cell migration assay, we show that over expression of cyclooxygenase (COX)-2, its metabolite prostaglandin E2 (PGE2) and PGE2 receptors promote the migration of cells. We found that treatment of A375 and Hs294 cells with berberine resulted in concentration-dependent inhibition of migration of these cells, which was associated with a reduction in the levels of COX-2, PGE2 and PGE2 receptors (EP2 and EP4). Treatment of cells with celecoxib, a COX-2 inhibitor, or transient transfection of cells with COX-2 small interfering RNA, also inhibited cell migration. Treatment of the cells with 12-O-tetradecanoylphorbol-13-acetate (TPA), an inducer of COX-2 or PGE2, enhanced cell migration, whereas berberine inhibited TPA- or PGE2-promoted cell migration. Berberine reduced the basal levels as well as PGE2-stimulated expression levels of EP2 and EP4. Treatment of the cells with the EP4 agonist stimulated cell migration and berberine blocked EP4 agonist-induced cell migration activity. Moreover, berberine inhibited the activation of nuclear factor-kappa B (NF-κB), an upstream regulator of COX-2, in A375 cells, and treatment of cells with caffeic acid phenethyl ester, an inhibitor of NF-κB, inhibited cell migration. Together, these results indicate for the first time that berberine inhibits melanoma cell migration, an essential step in invasion and metastasis, by inhibition of COX-2, PGE2 and PGE2 receptors. PMID:20974686

  16. Olive oil compounds inhibit the paracrine regulation of TNF-α-induced endothelial cell migration through reduced glioblastoma cell cyclooxygenase-2 expression.

    PubMed

    Lamy, Sylvie; Ben Saad, Aroua; Zgheib, Alain; Annabi, Borhane

    2016-01-01

    The established causal relationship between the chronic inflammatory microenvironment, tumor development and cancer recurrence has provided leads for developing novel preventive strategies. Accumulating experimental, clinical and epidemiological data has provided support for the chemopreventive properties of olive oil compounds traditionally found within the Mediterranean diet. In this study, we investigated whether tyrosol (Tyr), hydroxytyrosol, oleuropein and oleic acid (OA), four compounds contained in extra virgin olive oil, can prevent tumor necrosis factor (TNF)-α-induced expression of cyclooxygenase (COX)-2 (an inflammation biomarker) in a human glioblastoma cell (U-87 MG) model. We found that Tyr and OA significantly inhibited TNF-α-induced COX-2 gene and protein expression, as well as PGE2 secretion. Both compounds also inhibited TNF-α-induced JNK and ERK phosphorylation, whereas only Tyr inhibited TNF-α-induced NF-κB phosphorylation. Paracrine-regulated migration of human brain microvascular endothelial cells (HBMECs) was assessed using growth factor-enriched conditioned media (CM) isolated from U-87 MG cells. We found that while PGE2 triggered HBMEC migration, the CM isolated from U-87 MG cells, where either COX-2 or NF-κB had been silenced or had been treated with Tyr or OA, exhibited decreased chemotactic properties. These observations demonstrate that olive oil compounds inhibit the effect of the chronic inflammatory microenvironment on glioblastoma progression through TNF-α actions and may be useful in cancer chemoprevention.

  17. Efficient synthesis of apricoxib, CS-706, a selective cyclooxygenase-2 inhibitor, and evaluation of inhibition of prostaglandin E2 production in inflammatory breast cancer cells.

    PubMed

    Mandal, Pijus K; Freiter, Eric M; Bagsby, Allison L; Robertson, Fredika M; McMurray, John S

    2011-10-15

    An efficient synthesis of apricoxib (CS-706), a selective cyclooxygenase inhibitor, was developed using copper catalyzed homoallylic ketone formation from methyl 4-ethoxybenzoate followed by ozonolysis to an aldehyde, and condensation with sulfanilamide. This method provided multi-gram access of aprocoxib in good yield. Apricoxib exhibited potency equal to celecoxib at inhibition of prostaglandin E2 synthesis in two inflammatory breast cancer cell lines. PMID:21903394

  18. Induction of G2/M arrest and inhibition of cyclooxygenase-2 activity by curcumin in human bladder cancer T24 cells.

    PubMed

    Park, Cheol; Kim, Gi Young; Kim, Gun Do; Choi, Byung Tae; Park, Yeong-Min; Choi, Yung Hyun

    2006-05-01

    Curcumin, a polyphenol compound derived from Curcuma longa Linn, has been recognized as a promising anti-cancer drug due to its multiple properties including anti-inflammatory, anti-oxidant and anti-carcinogenic activities. To elucidate the mechanisms by which curcumin inhibits human bladder carcinoma T24 cell proliferation, we tested the effects of curcumin on specific cell cycle pathways and on the expression of cyclooxygenases (COXs). Curcumin inhibited the growth of T24 cells and induced G2/M arrest in a concentration-dependent manner, effects associated with the down-regulation of cyclin A and up-regulation of cyclin-dependent kinase (Cdk) inhibitor p21 (WAF1/CIP1). However, other G2/M regulatory molecules, such as cyclin A, Cdc2, Cdk2, Wee1 and Cdc25C, were not modulated by curcumin treatment. Furthermore, curcumin decreased the levels of COX-2 mRNA and protein expression without significant changes in the levels of COX-1, which correlated with a decrease in prostaglandin E2 (PGE2) synthesis. These observations suggest that curcumin may have therapeutic potential for bladder cancer patients. PMID:16596191

  19. Inhibition of cyclooxygenase-1 and cyclooxygenase-2 impairs Trypanosoma cruzi entry into cardiac cells and promotes differential modulation of the inflammatory response.

    PubMed

    Malvezi, Aparecida D; Panis, Carolina; da Silva, Rosiane V; de Freitas, Rafael Carvalho; Lovo-Martins, Maria I; Tatakihara, Vera L H; Zanluqui, Nágela G; Neto, Edecio Cunha; Goldenberg, Samuel; Bordignon, Juliano; Yamada-Ogatta, Sueli F; Martins-Pinge, Marli C; Cecchini, Rubens; Pinge-Filho, Phileno

    2014-10-01

    The intracellular protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a serious disorder that affects millions of people in Latin America. Cell invasion by T. cruzi and its intracellular replication are essential to the parasite's life cycle and for the development of Chagas disease. Here, we present evidence suggesting the involvement of the host's cyclooxygenase (COX) enzymes during T. cruzi invasion. Pharmacological antagonists for COX-1 (aspirin) and COX-2 (celecoxib) caused marked inhibition of T. cruzi infection when rat cardiac cells were pretreated with these nonsteroidal anti-inflammatory drugs (NSAIDs) for 60 min at 37°C before inoculation. This inhibition was associated with an increase in the production of NO and interleukin-1β and decreased production of transforming growth factor β (TGF-β) by cells. Taken together, these results indicate that COX-1 more than COX-2 is involved in the regulation of anti-T. cruzi activity in cardiac cells, and they provide a better understanding of the influence of TGF-β-interfering therapies on the innate inflammatory response to T. cruzi infection and may represent a very pertinent target for new therapeutic treatments of Chagas disease. PMID:25092706

  20. Inhibition of Cyclooxygenase-1 and Cyclooxygenase-2 Impairs Trypanosoma cruzi Entry into Cardiac Cells and Promotes Differential Modulation of the Inflammatory Response

    PubMed Central

    Malvezi, Aparecida D.; Panis, Carolina; da Silva, Rosiane V.; de Freitas, Rafael Carvalho; Lovo-Martins, Maria I.; Tatakihara, Vera L. H.; Zanluqui, Nágela G.; Neto, Edecio Cunha; Goldenberg, Samuel; Bordignon, Juliano; Yamada-Ogatta, Sueli F.; Martins-Pinge, Marli C.; Cecchini, Rubens

    2014-01-01

    The intracellular protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a serious disorder that affects millions of people in Latin America. Cell invasion by T. cruzi and its intracellular replication are essential to the parasite's life cycle and for the development of Chagas disease. Here, we present evidence suggesting the involvement of the host's cyclooxygenase (COX) enzymes during T. cruzi invasion. Pharmacological antagonists for COX-1 (aspirin) and COX-2 (celecoxib) caused marked inhibition of T. cruzi infection when rat cardiac cells were pretreated with these nonsteroidal anti-inflammatory drugs (NSAIDs) for 60 min at 37°C before inoculation. This inhibition was associated with an increase in the production of NO and interleukin-1β and decreased production of transforming growth factor β (TGF-β) by cells. Taken together, these results indicate that COX-1 more than COX-2 is involved in the regulation of anti-T. cruzi activity in cardiac cells, and they provide a better understanding of the influence of TGF-β-interfering therapies on the innate inflammatory response to T. cruzi infection and may represent a very pertinent target for new therapeutic treatments of Chagas disease. PMID:25092706

  1. [Cyclooxygenase 2 inhibitors and colorectal cancer].

    PubMed

    Bernardeau-Mozer, Marianne; Chaussade, Stanislas

    2004-05-01

    Cyclooxygenase-2 (Cox2) is an inductible isoenzyme of cyclooxygenase undetectable in normal colonic mucosa and overexpressed in 80% colonic tumor. Several works in vitro and in vivo showed that Cox2 plays a key role in the multistep process of colorectal tumorigenesis such apoptosis inhibition of cellular proliferation and angiogenesis induction. So that Cox2 represent a potential molecular target in colorectal management and specific Cox2 inhibitors may be useful as chemopreventive as well as therapeutic agent in humans. In animals study Cox2 inhibitors was shown to be effective and in humans Cox2 inhibitors are approved by the Food and Drug Administration as an adjunct to endoscopic surveillance and surgery in patients with Familial Adenomatous Polyposis (FAP). The purpose of this article is to review the relationship between Cox2/Cox2 inhibitors and differents signaling pathways of colorectal carcinogenesis and to precise their possible molecular mechanisms of action. This work although review clinicals data of their efficacy as chemopreventive agent as well as therapeutic in the differents group at risk for colorectal cancer. PMID:15239336

  2. Inhibition of lipopolysaccharide-induced cyclooxygenase-2 expression and inducible nitric oxide synthase by 4-[(2′-O-acetyl-α-l-rhamnosyloxy)benzyl]isothiocyanate from Moringa oleifera

    PubMed Central

    Park, Eun-Jung; Cheenpracha, Sarot; Chang, Leng Chee; Kondratyuk, Tamara P.; Pezzuto, John M.

    2011-01-01

    Moringa oleifera Lamarack is commonly consumed for nutritional or medicinal properties. We recently reported the isolation and structure elucidation of novel bioactive phenolic glycosides, including 4-[(2′-O-acetyl-α-l-rhamnosyloxy)benzyl]isothiocyanate (RBITC), which was found to suppress inducible nitric oxide synthase (iNOS) expression and nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 mouse macrophage cells. Inhibitors of proteins such as cyclooxygenase-2 (COX-2) and iNOS are potential anti-inflammatory and cancer chemopreventive agents. The inhibitory activity of RBITC on NO production (IC50 = 0.96 ± 0.23 µM) was greater than that mediated by other well-known isothiocyanates such as sulforaphane (IC50 = 2.86 ± 0.39 µM) and benzyl isothiocyanate (IC50 = 2.08 ± 0.28 µM). RBITC inhibited expression of COX-2 and iNOS at both the protein and mRNA levels. Major upstream signaling pathways involved mitogen-activated protein kinases and nuclear factor-κB (NF-κB). RBITC inhibited phosphorylation of extracellular signal regulated kinase and stress-activated protein kinase, as well as ubiquitin-dependent degradation of inhibitor κBα (IκBα). In accordance with IκBα degradation, nuclear accumulation of NF-κB, and subsequent binding to NF-κB cis-acting element, was attenuated by treatment with RBITC. These data suggest RBITC should be included in the dietary armamentarium of isothiocyanates potentially capable of mediating anti-inflammatory or cancer chemopreventive activity. PMID:21774591

  3. Inhibition of fatty acid amide hydrolase and cyclooxygenase-2 increases levels of endocannabinoid related molecules and produces analgesia via peroxisome proliferator-activated receptor-alpha in a model of inflammatory pain.

    PubMed

    Jhaveri, Maulik D; Richardson, Denise; Robinson, Ian; Garle, Michael J; Patel, Annie; Sun, Yan; Sagar, Devi R; Bennett, Andrew J; Alexander, Stephen P H; Kendall, David A; Barrett, David A; Chapman, Victoria

    2008-07-01

    The antinociceptive effects of the endocannabinoids (ECs) are enhanced by inhibiting catabolic enzymes such as fatty acid amide hydrolase (FAAH). The physiological relevance of the metabolism of ECs by other pathways, such as cyclooxygenase-2 (COX2) is less clear. To address this question we compared the effects of local inhibition of FAAH versus COX2 (URB597 and nimesulide, respectively) on inflammatory hyperalgesia and levels of endocannabinoids and related molecules in the hindpaw. Inflammatory hyperalgesia was measured following intraplantar injection of carrageenan. Effects of intraplantar injection of URB597 (25 microg and 100 microg) or nimesulide (50 microg) on hyperalgesia and hindpaw levels of anandamide (AEA), 2-arachidonoylglycerol (2AG) and N-palmitoylethanolamine (PEA) were determined. Although both doses of URB597 increased levels of AEA and 2AG in the carrageenan inflamed hindpaw, only the lower dose of URB597 attenuated hyperalgesia (P<0.05). Nimesulide attenuated both hyperalgesia and hindpaw oedema (P<0.001, P<0.01, respectively) and increased levels of PEA (P<0.05) in the hindpaw. Since both AEA and PEA are ligands for peroxisome proliferator-activated receptor-alpha (PPARalpha), the effects of the PPARalpha antagonist GW6471 on nimesulide- and URB597-mediated effects were studied. GW6471, but not a PPARgamma antagonist, blocked the inhibitory effects of nimesulide and URB597 on hyperalgesia. Our data suggest that both COX2 and FAAH play a role in the metabolism of endocannabinoids and related molecules. The finding that PPARalpha antagonism blocked the inhibitory effects of nimesulide and URB597 suggests that PPARalpha contributes to their antinociceptive effects in the carrageenan model of inflammatory hyperalgesia.

  4. A Revised Mechanism for Human Cyclooxygenase-2.

    PubMed

    Liu, Yi; Roth, Justine P

    2016-01-01

    The mechanism of ω-6 polyunsaturated fatty acid oxidation by wild-type cyclooxygenase 2 and the Y334F variant, lacking a conserved hydrogen bond to the catalytic tyrosyl radical/tyrosine, was examined for the first time under physiologically relevant conditions. The enzymes show apparent bimolecular rate constants and deuterium kinetic isotope effects that increase in proportion to co-substrate concentrations before converging to limiting values. The trends exclude multiple dioxygenase mechanisms as well as the proposal that initial hydrogen atom abstraction from the fatty acid is the first irreversible step in catalysis. Temperature dependent kinetic studies reinforce the novel finding that hydrogen transfer from the reduced catalytic tyrosine to a terminal peroxyl radical is the first irreversible step that controls regio- and stereospecific product formation. PMID:26565028

  5. Cyclooxygenase-2 in newborn hyperoxic lung injury.

    PubMed

    Britt, Rodney D; Velten, Markus; Tipple, Trent E; Nelin, Leif D; Rogers, Lynette K

    2013-08-01

    Supraphysiological O2 concentrations, mechanical ventilation, and inflammation significantly contribute to the development of bronchopulmonary dysplasia (BPD).Exposure of newborn mice to hyperoxia causes inflammation and impaired alveolarization similar to that seen in infants with BPD.Previously, we demonstrated that pulmonary cyclooxygenase-2 (COX-2) protein expression is increased in hyperoxia-exposed newborn mice.The present studies were designed to define the role of COX-2 in newborn hyperoxic lung injury.We tested the hypothesis that attenuation of COX-2 activity would reduce hyperoxia-induced inflammation and improve alveolarization.Newborn C3H/HeN micewere injected daily with vehicle, aspirin (nonselective COX-2 inhibitor), or celecoxib (selective COX-2 inhibitor) for the first 7 days of life.Additional studies utilized wild-type (C57Bl/6, COX-2(+/+)), heterozygous (COX-2(+/-)), and homozygous (COX-2(-/-)) transgenic mice.Micewere exposed to room air (21% O2) or hyperoxia (85% O2) for 14 days.Aspirin-injected and COX-2(-/-) pups had reduced levels of monocyte chemoattractant protein (MCP-1) in bronchoalveolar lavage fluid (BAL).Both aspirin and celecoxib treatment reduced macrophage numbers in the alveolar walls and air spaces.Aspirin and celecoxib treatment attenuated hyperoxia-induced COX activity, including altered levels of prostaglandin (PG)D2 metabolites.Decreased COX activity, however, did not prevent hyperoxia-induced lung developmental deficits.Our data suggest thatincreased COX-2 activity may contribute to proinflammatory responses, including macrophage chemotaxis, during exposure to hyperoxia.Modulation of COX-2 activity may be a useful therapeutic target to limit hyperoxia-induced inflammation in preterm infants at risk of developing BPD. PMID:23624331

  6. Competition and allostery govern substrate selectivity of cyclooxygenase-2.

    PubMed

    Mitchener, Michelle M; Hermanson, Daniel J; Shockley, Erin M; Brown, H Alex; Lindsley, Craig W; Reese, Jeff; Rouzer, Carol A; Lopez, Carlos F; Marnett, Lawrence J

    2015-10-01

    Cyclooxygenase-2 (COX-2) oxygenates arachidonic acid (AA) and its ester analog, 2-arachidonoylglycerol (2-AG), to prostaglandins (PGs) and prostaglandin glyceryl esters (PG-Gs), respectively. Although the efficiency of oxygenation of these substrates by COX-2 in vitro is similar, cellular biosynthesis of PGs far exceeds that of PG-Gs. Evidence that the COX enzymes are functional heterodimers suggests that competitive interaction of AA and 2-AG at the allosteric site of COX-2 might result in differential regulation of the oxygenation of the two substrates when both are present. Modulation of AA levels in RAW264.7 macrophages uncovered an inverse correlation between cellular AA levels and PG-G biosynthesis. In vitro kinetic analysis using purified protein demonstrated that the inhibition of 2-AG oxygenation by high concentrations of AA far exceeded the inhibition of AA oxygenation by high concentrations of 2-AG. An unbiased systems-based mechanistic model of the kinetic data revealed that binding of AA or 2-AG at the allosteric site of COX-2 results in a decreased catalytic efficiency of the enzyme toward 2-AG, whereas 2-AG binding at the allosteric site increases COX-2's efficiency toward AA. The results suggest that substrates interact with COX-2 via multiple potential complexes involving binding to both the catalytic and allosteric sites. Competition between AA and 2-AG for these sites, combined with differential allosteric modulation, gives rise to a complex interplay between the substrates, leading to preferential oxygenation of AA.

  7. [Cyclooxygenase-2: a new therapeutic target in atherosclerosis?].

    PubMed

    Páramo, José A; Beloqui, Oscar; Orbe, Josune

    2006-05-27

    It is now widely accepted that atherosclerosis is a complex chronic inflammatory disorder of the arterial tree associated with several risk factors. From the initial phases to eventual rupture of vulnerable atherosclerotic plaques, a low-grade inflammation, also termed microinflammation, appears to play a key pathogenetic role. Systemic inflammatory markers (C reactive protein, cytokines adhesion molecules) also play a role in this process. Experimental and clinical evidence suggests that cyclooxygenase-2 (COX-2), an enzyme which catalyzes the generation of prostaglandins from arachidonic acid, also contributes to lesion formation. Recent reports by our group have demonstrated increased monocyte COX-2 activity and the production of prostaglandin E2 in relation to cardiovascular risk factors and subclinical atherosclerosis in asymptomatic subjects. Our findings support the notion that the COX-2/prostaglandin E2 axis may have a role, raising the question as to whether its selective inhibition might be an attractive therapeutic target in atherosclerosis. COX-2 inhibitors, collectively called "coxibs" (celecoxib, rofecoxib, valdecoxib, lumiracoxib, etc), held a promise as anti-inflammatory drugs without the some of the side effects of aspirin or non steroidal antiinflammatory agents. However, clinical studies raise several clinically relevant questions as to their beneficial role in atherosclerosis prevention, because of increased thrombogenicity and cardiovascular risk, and therefore coxibs should be restricted in atherosclerosis-prone patients.

  8. Cyclooxygenase-2 Mediates Anandamide Metabolism in the Mouse Brain

    PubMed Central

    Kaczocha, Martin

    2010-01-01

    Cyclooxygenase-2 (COX-2) mediates inflammation and contributes to neurodegeneration. Best known for its pathological up-regulation, COX-2 is also constitutively expressed within the brain and mediates synaptic transmission through prostaglandin synthesis. Along with arachidonic acid, COX-2 oxygenates the endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol in vitro. Inhibition of COX-2 enhances retrograde signaling in the hippocampus, suggesting COX-2 mediates endocannabinoid tone in healthy brain. The degree to which COX-2 may regulate endocannabinoid metabolism in vivo is currently unclear. Therefore, we explored the effect of COX-2 inhibition on [3H]AEA metabolism in mouse brain. Although AEA is hydrolyzed primarily by fatty acid amide hydrolase (FAAH), ex vivo autoradiography revealed that COX-2 inhibition by nimesulide redirected [3H]AEA substrate from COX-2 to FAAH in the cortex, hippocampus, thalamus, and periaqueductal gray. These data indicate that COX-2 possesses the capacity to metabolize AEA in vivo and can compete with FAAH for AEA in several brain regions. Temporal fluctuations in COX-2 expression were observed in the brain, with an increase in COX-2 protein and mRNA in the hippocampus at midnight compared with noon. COX-2 immunolocalization was robust in the hippocampus and several cortical regions. Although most regions exhibited no temporal changes in COX-2 immunolocalization, increased numbers of immunoreactive cells were detected at midnight in layers II and III of the somatosensory and visual cortices. These temporal variations in COX-2 distribution reduced the enzyme's contribution toward [3H]AEA metabolism in the somatosensory cortex at midnight. Taken together, our findings establish COX-2 as a mediator of regional AEA metabolism in mouse brain. PMID:20702753

  9. Cyclooxygenase-2 inhibitors in ginger (Zingiber officinale)

    PubMed Central

    van Breemen, Richard B.; Tao, Yi; Li, Wenkui

    2010-01-01

    Ginger roots have been used to treat inflammation and have been reported to inhibit cyclooxygenase (COX). Ultrafiltration liquid chromatography mass spectrometry was used to screen a chloroform partition of a methanol extract of ginger roots for COX-2 ligands, and 10-gingerol, 12-gingerol, 8-shogaol, 10-shogaol, 6-gingerdione, 8-gingerdione, 10-gingerdione, 6-dehydro-10-gingerol, 6-paradol, and 8-paradol bound to the enzyme active site. Purified 10-gingerol, 8-shogaol and 10-shogaol inhibited COX-2 with IC50 values of 32 μM, 17.5 μM and 7.5 μM, respectively. No inhibition of COX-1 was detected. Therefore, 10-gingerol, 8-shogaol and 10-shogaol inhibit COX-2 but not COX-1, which can explain, in part, anti-inflammatory properties of ginger. PMID:20837112

  10. Competition and allostery govern substrate selectivity of cyclooxygenase-2

    PubMed Central

    Mitchener, Michelle M.; Hermanson, Daniel J.; Shockley, Erin M.; Brown, H. Alex; Lindsley, Craig W.; Reese, Jeff; Rouzer, Carol A.; Lopez, Carlos F.; Marnett, Lawrence J.

    2015-01-01

    Cyclooxygenase-2 (COX-2) oxygenates arachidonic acid (AA) and its ester analog, 2-arachidonoylglycerol (2-AG), to prostaglandins (PGs) and prostaglandin glyceryl esters (PG-Gs), respectively. Although the efficiency of oxygenation of these substrates by COX-2 in vitro is similar, cellular biosynthesis of PGs far exceeds that of PG-Gs. Evidence that the COX enzymes are functional heterodimers suggests that competitive interaction of AA and 2-AG at the allosteric site of COX-2 might result in differential regulation of the oxygenation of the two substrates when both are present. Modulation of AA levels in RAW264.7 macrophages uncovered an inverse correlation between cellular AA levels and PG-G biosynthesis. In vitro kinetic analysis using purified protein demonstrated that the inhibition of 2-AG oxygenation by high concentrations of AA far exceeded the inhibition of AA oxygenation by high concentrations of 2-AG. An unbiased systems-based mechanistic model of the kinetic data revealed that binding of AA or 2-AG at the allosteric site of COX-2 results in a decreased catalytic efficiency of the enzyme toward 2-AG, whereas 2-AG binding at the allosteric site increases COX-2’s efficiency toward AA. The results suggest that substrates interact with COX-2 via multiple potential complexes involving binding to both the catalytic and allosteric sites. Competition between AA and 2-AG for these sites, combined with differential allosteric modulation, gives rise to a complex interplay between the substrates, leading to preferential oxygenation of AA. PMID:26392530

  11. Suppression of cyclooxygenase-2 gene transcription by humulon of beer hop extract studied with reference to glucocorticoid.

    PubMed

    Yamamoto, K; Wang, J; Yamamoto, S; Tobe, H

    2000-01-14

    In murine osteoblastic MC3T3-E1 cells which produced prostaglandin E2 as a bone resorption factor, the cyclooxygenase-2 induction by tumor necrosis factor alpha (TNFalpha) was suppressed by dexamethasone with an IC(50) of 1 nM. Humulon isolated from hop extract for beer brewing was reported previously as an inhibitor of bone resorption [Tobe, H. et al. (1997) Biosci. Biotech. Biochem. 61, 158-159]. We showed that the compound suppressed the TNFalpha-dependent cyclooxygenase-2 induction with an IC(50) of as low as about 30 nM as demonstrated experimentally by catalytic activity assay, Northern blot analysis and promoter analysis. Reporter gene experiments suggested that humulon blocked the cyclooxygenase-2 expression mediated by NFkappaB and NF-IL6, but the intracellular glucocorticoid receptor was not involved. The catalytic activity of cyclooxygenase-2 was inhibited by humulon with an IC(50) of as high as 1.6 microM. These results showed that humulon suppressed cyclooxygenase-2 induction at the step of transcription.

  12. Cyclooxygenase-2 inhibitors: promise or peril?

    PubMed Central

    Mengle-Gaw, Laurel J; Schwartz, Benjamin D

    2002-01-01

    The discovery of two isoforms of the cyclooxygenase enzyme, COX-1 and COX-2, and the development of COX-2-specific inhibitors as anti-inflammatories and analgesics have offered great promise that the therapeutic benefits of NSAIDs could be optimized through inhibition of COX-2, while minimizing their adverse side effect profile associated with inhibition of COX-1. While COX-2 specific inhibitors have proven to be efficacious in a variety of inflammatory conditions, exposure of large numbers of patients to these drugs in postmarketing studies have uncovered potential safety concerns that raise questions about the benefit/risk ratio of COX-2-specific NSAIDs compared to conventional NSAIDs. This article reviews the efficacy and safety profiles of COX-2-specific inhibitors, comparing them with conventional NSDAIDs. PMID:12467519

  13. Specific cyclooxygenase-2 (COX-2) inhibitors.

    PubMed

    Rubin, B R

    1999-06-01

    Nonsteroidal anti-inflammatory drugs (NSAIDs) are currently among the most widely prescribed drugs worldwide. Their therapeutic benefits and their side effects in the gastrointestinal tract and kidney, as well as in hemostasis, are of great importance in modern medicine. Within the past decade, new insights into how NSAIDs produce both their therapeutic benefits and their serious side effects have been discovered. It is now known that there are two froms of the cyclooxygenase (COX) enzyme that metabolize arachidonic acid into prostaglandins. Drugs that specifically inhibit the COX-2 enzyme were formulated and put into clinical trials during the past 5 years. These drugs are now available to treat patients in the United States. Specific COX-2 inhibitors offer the benefit of being able to treat the pain and inflammation of arthritis with potentially little risk of serious gastrointestinal injury.

  14. Endoglin regulates cyclooxygenase-2 expression and activity.

    PubMed

    Jerkic, Mirjana; Rivas-Elena, Juan V; Santibanez, Juan F; Prieto, Marta; Rodríguez-Barbero, Alicia; Perez-Barriocanal, Fernando; Pericacho, Miguel; Arévalo, Miguel; Vary, Calvin P H; Letarte, Michelle; Bernabeu, Carmelo; López-Novoa, Jose M

    2006-08-01

    The endoglin heterozygous (Eng(+/-)) mouse, which serves as a model of hereditary hemorrhagic telangiectasia (HHT), was shown to express reduced levels of endothelial NO synthase (eNOS) with impaired activity. Because of intricate changes in vasomotor function in the Eng(+/-) mice and the potential interactions between the NO- and prostaglandin-producing pathways, we assessed the expression and function of cyclooxygenase (COX) isoforms. A specific upregulation of COX-2 in the vascular endothelium and increased urinary excretion of prostaglandin E(2) were observed in the Eng(+/-) mice. Specific COX-2 inhibition with parecoxib transiently increased arterial pressure in Eng(+/-) but not in Eng(+/+) mice. Transfection of endoglin in L6E9 myoblasts, shown previously to stimulate eNOS expression, led to downregulation of COX-2 with no change in COX-1. In addition, COX-2 promoter activity and protein levels were inversely correlated with endoglin levels, in doxycyclin-inducible endothelial cells. Chronic NO synthesis inhibition with N(omega)-nitro-l-arginine methyl ester induced a marked increase in COX-2 only in the normal Eng(+/+) mice. N(omega)-nitro-l-arginine methyl ester also increased COX-2 expression and promoter activity in doxycyclin-inducible endoglin expressing endothelial cells, but not in control cells. The level of COX-2 expression following transforming growth factor-beta1 treatment was less in endoglin than in mock transfected L6E9 myoblasts and was higher in human endothelial cells silenced for endoglin expression. Our results indicate that endoglin is involved in the regulation of COX-2 activity. Furthermore, reduced endoglin levels and associated impaired NO production may be responsible, at least in part, for augmented COX-2 expression and activity in the Eng(+/-) mice. PMID:16840721

  15. Salidroside suppresses solar ultraviolet-induced skin inflammation by targeting cyclooxygenase-2

    PubMed Central

    Ke, Changshu; Xiong, Hua; Chen, Jingwen; Guo, Jinguang; Lu, Mingmin; Ding, Yanyan; Fan, Xiaoming; Duan, Qiuhong; Shi, Fei; Zhu, Feng

    2016-01-01

    Solar ultraviolet (SUV) irradiation causes skin disorders such as inflammation, photoaging, and carcinogenesis. Cyclooxygenase-2 (COX-2) plays a key role in SUV-induced skin inflammation, and targeting COX-2 may be a strategy to prevent skin disorders. In this study, we found that the expression of COX-2, phosphorylation of p38 or JNKs were increased in human solar dermatitis tissues and SUV-irradiated human skin keratinocyte HaCaT cells and mouse epidermal JB6 Cl41 cells. Knocking down COX-2 inhibited the production of prostaglandin E2 (PGE2), the phosphorylation of p38 or JNKs in SUV-irradiated cells, which indicated that COX-2 is not only the key enzyme for PGs synthesis, but also an upstream regulator of p38 or JNKs after SUV irradiation. The virtual ligand screening assay was used to search for natural drugs in the Chinese Medicine Database, and indicated that salidroside might be a COX-2 inhibitor. Molecule modeling indicated that salidroside can directly bind with COX-2, which was proved by in vitro pull-down binding assay. Ex vivo studies showed that salidroside has no toxicity to cells, and inhibits the production of PGE2, phosphorylation of p38 or JNKs, and secretion of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) caused by SUV irradiation. In vivo studies demonstrated that salidroside attenuates the skin inflammation induced by SUV. In brief, our data provided the evidences for the protective role of salidroside against SUV-induced inflammation by targeting COX-2, and salidroside might be a promising drug for the treatment of SUV-induced skin inflammation. PMID:27028995

  16. Crystallization of recombinant cyclo-oxygenase-2

    NASA Astrophysics Data System (ADS)

    Stevens, Anna M.; Pawlitz, Jennifer L.; Kurumbail, Ravi G.; Gierse, James K.; Moreland, Kirby T.; Stegeman, Roderick A.; Loduca, Jina Y.; Stallings, William C.

    1999-01-01

    The integral membrane protein, prostaglandin H 2 synthase, or cyclo-oxygenase (COX), catalyses the first step in the conversion of arachidonic acid to prostaglandins (PGs) and is the target of nonsteroidal anti-inflammatory drugs (NSAIDs). Two isoforms are known. The constitutive enzyme, COX-1, is present in most tissues and is responsible for the physiological production of PGs. The isoform responsible for the elevated production of PGs during inflammation is COX-2 which is induced specifically at inflammatory sites. Three-dimensional structures of inhibitor complexes of COX-2, and of site variants of COX-2 which mimic COX-1, provide insight into the structural basis for selective inhibition of COX-2. Additionally, structures of COX-2 mutants and complexes with the substrate can provide a clearer understanding of the catalytic mechanism of the reaction. A crystallization protocol has been developed for COX-2 which reproducibly yields diffraction quality crystals. Polyethyleneglycol 550 monomethylether (MMP550) and MgCl 2 were systematically varied and used in conjunction with the detergent β- D-octylglucopyranoside ( β-OG). As a result of many crystallization trials, we determined that the initial β-OG concentration should be held constant, allowing the salt concentration to modulate the critical micelle concentration (CMC) of the detergent. Over 25 crystal structures have been solved using crystals generated from this system. Most crystals belong to the space group P2 12 12, with lattice constants of a=180, b=134, c=120 Å in a pseudo body-centered lattice.

  17. Budesonide epimer R or dexamethasone selectively inhibit platelet-activating factor-induced or interleukin 1β-induced DNA binding activity of cis-acting transcription factors and cyclooxygenase-2 gene expression in human epidermal keratinocytes

    PubMed Central

    Lukiw, Walter J.; Pelaez, Ricardo Palacios; Martinez, Jorge; Bazan, Nicolas G.

    1998-01-01

    To further understand the molecular mechanism of glucocorticoid action on gene expression, DNA-binding activities of the cis-acting transcription factors activator protein 1 (AP1), AP2, Egr1 (zif268), NF-κB, the signal transducers and activators of transcription proteins gamma interferon activation site (GAS), Sis-inducible element, and the TATA binding protein transcription factor II D (TFIID) were examined in human epidermal keratinocytes. The cytokine interleukin 1β (IL-1β) and platelet-activating factor (PAF), both potent mediators of inflammation, were used as triggers for gene expression. Budesonide epimer R (BUDeR) and dexamethasone (DEX) were studied as potential antagonists. BUDeR or DEX before IL-1β- or PAF-mediated gene induction elicited strong inhibition of AP1-, GAS-, and in particular NF-κB-DNA binding (P < 0.001, ANOVA). Only small effects were noted on AP2, Egr1 (zif268), and Sis-inducible element-DNA binding (P > 0.05). No significant effect was noted on the basal transcription factor TFIID recognition of TATA-containing core promoter sequences (P > 0.68). To test the hypothesis that changing cis-acting transcription factor binding activity may be involved in inflammatory-response related gene transcription, RNA message abundance for human cyclooxygenase (COX)-1 and -2 (E.C.1.14.99.1) was assessed in parallel by using reverse transcription–PCR. Although the COX-1 gene was found to be expressed at constitutively low levels, the TATA-containing COX-2 gene, which contains AP1-like, GAS, and NF-κB DNA-binding sites in its immediate promoter, was found to be strongly induced by IL-1β or PAF (P < 0.001). BUDeR and DEX both suppressed COX-2 RNA message generation; however, no correlation was associated with TFIID–DNA binding. These results suggest that on stimulation by mediators of inflammation, although the basal transcription machinery remains intact, modulation of cis-activating transcription factor AP1, GAS, and NF-κB-DNA binding by the

  18. The cyclooxygenase-2 selective inhibitor, etodolac, but not aspirin reduces neovascularization in a murine ischemic hind limb model.

    PubMed

    Tanaka, Kohei; Yamamoto, Yasutaka; Tsujimoto, Shunsuke; Uozumi, Naonori; Kita, Yoshihiro; Yoshida, Akio; Shimizu, Takao; Hisatome, Ichiro

    2010-02-10

    Cyclooxygenase inhibitors are often prescribed to relieve severe ischemic leg pain in critical ischemic limb patients. Prescription of high doses of aspirin and selective cyclooxygenase-2 inhibitors is reported to increase cardiovascular events through suppression of the vasodilative prostanoid prostaglandin I(2) in endothelium. Here, we evaluated the influence of aspirin and etodolac, a selective cyclooxygenase-2 inhibitor, on neovascularization using a murine ischemia hind limb model. C57BL/6J mice were treated with aspirin or etodolac for twenty-eight days after induction of ischemia. We exploited a concentration of the agents that suppressed cyclooxygenase activity efficiently, especially in prostaglandin I(2) production. Recovery of limb blood perfusion and capillary density in ischemic limbs was significantly suppressed by etodolac treatment when compared to the aspirin treated group and untreated group. Production of 6-keto prostaglandin F(1alpha) and prostaglandin E(2) was lower in the aspirin treated group when compared with the etodolac-treated group. Also, these concentrations were lower in both treatment groups compared with the untreated group. Immunohistochemical analysis suggested cyclooxygenase-2 was expressed in endothelium but not in inflammatory cells in ischemic tissue from the acute to chronic phase. Cyclooxygenase-1 was expressed strongly in inflammatory cells in the acute phase. Furthermore, bone marrow-derived mononuclear cell transplantation improved neovascularization, whereas aspirin and etodolac did not inhibit these effects. Production of arachidonic acid metabolites by transplanted cells was independent of the improvement of neovascularization. In conclusion, cyclooxygenase-2 inhibition reduces ischemia-induced neovascularization. PMID:19879866

  19. Ursolic acid from Plantago major, a selective inhibitor of cyclooxygenase-2 catalyzed prostaglandin biosynthesis.

    PubMed

    Ringbom, T; Segura, L; Noreen, Y; Perera, P; Bohlin, L

    1998-10-01

    A hexane extract of Plantago major was investigated by bioactivity-directed fractionation, using an in vitro cyclooxygenase-2 (COX-2) catalyzed prostaglandin biosynthesis inhibition assay, and resulted in the isolation of ursolic acid (1). This triterpenoid showed a significant COX-2 inhibitory effect, directly on the enzyme activity, with an IC50 value of 130 microM and a COX-2/COX-1 selectivity ratio of 0.6. The structural isomer oleanolic acid (2) was found to be less active than 1, with an IC50 value of 295 microM, but showed a similar selectivity ratio (0.8). Furthermore, no significant inhibition on COX-2 or COX-1 was observed by the triterpenoid, 18beta-glycyrrhetinic acid (3). The direct inhibitory effect of 1 and 2 on COX-2 catalyzed prostaglandin biosynthesis increased with preincubation, indicating a time-dependent inhibition, while the effect on COX-1 was found to be independent of preincubation time.

  20. Cyclooxygenase-2 is induced by p38 MAPK and promotes cell survival.

    PubMed

    Parente, Rosanna; Trifirò, Elisabetta; Cuozzo, Francesca; Valia, Sandro; Cirone, Mara; Di Renzo, Livia

    2013-05-01

    The Na+ ionophore monensin affects cellular pH and, depending on its concentration, causes the survival or death of tumor cells. In the present study, we elucidated the survival pathway activated in U937 cells, a human lymphoma-derived cell line. These cells treated with monensin at a concentration of 5 µM were growth-arrested in G1, activated p38 mitogen-activated protein kinase (MAPK) and showed an increased expression of cyclooxygenase-2 (COX-2). The latter two molecular events were linked, as pharmacological inhibition of the MAPK did not allow COX-2 increased expression. Furthermore, we showed that p38 and COX-2 keep monensin-stressed U937 cells alive, as pharmacological inhibition of each enzyme caused cell death. PMID:23446663

  1. Cyclooxygenase-2 (COX-2) expression in canine intracranial meningiomas.

    PubMed

    Rossmeisl, J H; Robertson, J L; Zimmerman, K L; Higgins, M A; Geiger, D A

    2009-09-01

    Meningiomas are the most common canine intracranial tumour. Neurologic disability and death from treatment failure remain problematic despite current surgical and radiotherapeutic treatments for canine intracranial meningiomas. Cyclooxygenase-2 (COX-2) over-expression has been demonstrated in multiple canine malignancies, and COX-2 inhibitory treatment strategies have been shown to have both preventative and therapeutic effects in spontaneous and experimental models of cancer. The purpose of this study was to evaluate COX-2 expression in canine intracranial meningiomas. Immunohistochemical and Western blot (WB) analyses showed COX-2 expression in multiple tissues of the normal canine brain, and 87% (21/24) of intracranial meningiomas studied were immunoreactive to COX-2. No significant associations between COX-2 immunoreactivity and tumour grade were identified. Further studies are required to elucidate the physiologic roles of constitutive COX-2 expression in the central nervous system as well as its participation in meningioma tumourigenesis. PMID:19691646

  2. Targeting Cyclooxygenase-2 in Hematological Malignancies: Rationale and Promise

    PubMed Central

    Bernard, M. P.; Bancos, S.; Sime, P. J.; Phipps, R. P.

    2009-01-01

    There is much interest in the potential use of Cox-2 selective inhibitors in combination with other cancer therapeutics. Malignancies of hematopoietic and non-hematopoietic origin often have increased expression of cyclooxygenase-2 (Cox-2), a key modulator of inflammation. For example, hematological malignancies such as chronic lymphocytic leukemia, chronic myeloid leukemia, Hodgkin’s lymphoma, non-Hodgkin’s lymphoma and multiple myeloma often highly express Cox-2, which correlates with poor patient prognosis. Expression of Cox-2 enhances survival and proliferation of malignant cells, while negatively influencing anti-tumor immunity. Hematological malignancies expressing elevated levels of Cox-2 potentially avoid immune responses by producing factors that enhance angiogenesis and metastases. Cellular immune responses regulated by natural killer cells, cytotoxic T lymphocytes, and T regulatory cells are also influenced by Cox-2 expression. Therefore, Cox-2 selective inhibitors have promising therapeutic potential in patients suffering from certain hematological malignancies. PMID:18691115

  3. Targeting cyclooxygenase-2 in hematological malignancies: rationale and promise.

    PubMed

    Bernard, M P; Bancos, S; Sime, P J; Phipps, R P

    2008-01-01

    There is much interest in the potential use of Cox-2 selective inhibitors in combination with other cancer therapeutics. Malignancies of hematopoietic and non-hematopoietic origin often have increased expression of cyclooxygenase-2 (Cox-2), a key modulator of inflammation. For example, hematological malignancies such as chronic lymphocytic leukemia, chronic myeloid leukemia, Hodgkin's lymphoma, non-Hodgkin's lymphoma and multiple myeloma often highly express Cox-2, which correlates with poor patient prognosis. Expression of Cox-2 enhances survival and proliferation of malignant cells, while negatively influencing anti-tumor immunity. Hematological malignancies expressing elevated levels of Cox-2 potentially avoid immune responses by producing factors that enhance angiogenesis and metastasis. Cellular immune responses regulated by natural killer cells, cytotoxic T lymphocytes, and T regulatory cells are also influenced by Cox-2 expression. Therefore, Cox-2 selective inhibitors have promising therapeutic potential in patients suffering from certain hematological malignancies.

  4. Suppressive effects of the kahweol and cafestol on cyclooxygenase-2 expression in macrophages.

    PubMed

    Kim, Ji Young; Jung, Kyung Sik; Jeong, Hye Gwang

    2004-07-01

    Inducible cyclooxygenase-2 (COX-2) has been suggested to play a role in the processes of inflammation and carcinogenesis. Recent studies have shown the chemoprotective effects of kahweol and cafestol, which are coffee-specific diterpenes. This study investigated the effects of kahweol and cafestol on the expression of COX-2 in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. Kahweol and cafestol significantly suppressed the LPS-induced production of prostaglandin E(2), COX-2 protein and mRNA expression, and COX-2 promoter activity in a dose-dependent manner. Furthermore, kahweol blocked the LPS-induced activation of NF-kappaB by preventing IkappaB degradation and inhibiting IkappaB kinase activity. These results will provide new insights into the anti-inflammatory and anti-carcinogenic properties of kahweol and cafestol. PMID:15225655

  5. Up-regulation of cyclooxygenase-2 by product-prostaglandin E2

    NASA Technical Reports Server (NTRS)

    Tjandrawinata, R. R.; Hughes-Fulford, M.

    1997-01-01

    The development of prostate cancer has been linked to high level of dietary fat intake. Our laboratory investigates the connection between cancer cell growth and fatty acid products. Studying human prostatic carcinoma PC-3 cells, we found that prostaglandin E2 (PGE2) increased cell growth and up-regulated the gene expression of its own synthesizing enzyme, cyclooxygenase-2 (COX-2). PGE2 increased COX-2 mRNA expression dose-dependently with the highest levels of stimulation seen at the 3-hour period following PGE2 addition. The NSAID flurbiprofen (5 microM), in the presence of exogenous PGE2, inhibited the up-regulation of COX-2 mRNA and cell growth. These data suggest that the levels of local intracellular PGE2 play a major role in the growth of prostate cancer cells through an activation of COX-2 gene expression.

  6. Cyclooxygenase-2 blockade can improve efficacy of VEGF-targeting drugs

    PubMed Central

    Ben-Batalla, Isabel; Cubas-Cordova, Miguel; Udonta, Florian; Wroblewski, Mark; Waizenegger, Jonas S.; Janning, Melanie; Sawall, Stefanie; Gensch, Victoria; Zhao, Lin; Martinez-Zubiaurre, Iñigo; Riecken, Kristoffer; Fehse, Boris; Pantel, Klaus; Bokemeyer, Carsten; Loges, Sonja

    2015-01-01

    Anti-angiogenic therapies were approved for different cancers. However, significant primary and secondary resistance hampers efficacy in several tumor types including breast cancer. Thus, we need to develop clinically applicable strategies to enhance efficacy of anti-angiogenic drugs. We report that anti-angiogenic therapies can induce upregulation of cyclooxygenase-2 (Cox-2) and of its product prostaglandin E2 (PGE2) in breast cancer models. Upon Cox-2 inhibition PGE2 levels were normalized and efficacy of anti-vascular endothelial growth factor receptor 2 (anti-VEGFR-2) antibodies and sunitinib was enhanced. Interestingly, both treatments exerted additive anti-angiogenic effects. Following Cox-2 inhibition, we observed reduced infiltration of tumors with cancer-associated fibroblasts (CAFs) and lower levels of pro-angiogenic factors active besides the VEGF axis including hepatocyte growth factor (HGF) and basic fibroblast growth factor (FGF2). Mechanistic studies indicated that Cox-2 inhibition reduced PGE2-induced migration and proliferation of CAFs via inhibiting phosphorylation of Akt. Hence, Cox-2 inhibition can increase efficacy of anti-angiogenic treatments and our findings might pave the road for clinical investigations of concomitant blockade of Cox-2 and VEGF-signaling. PMID:25849942

  7. DNA-PKcs-Dependent Modulation of Cellular Radiosensitivity by a Selective Cyclooxygenase-2 Inhibitor

    SciTech Connect

    Kodym, Elisabeth; Kodym, Reinhard; Chen, Benjamin P.; Chen, David J.; Morotomi-Yano, Keiko; Choy, Hak; Saha, Debabrata

    2007-09-01

    Purpose: Inhibition of cyclooxygenase-2 has been shown to increase radiosensitivity. Recently, the suppression of radiation-induced DNA-dependant protein kinase (DNA-PK) activity by the selective cyclooxygenase-2 inhibitor celecoxib was reported. Given the importance of DNA-PK for repair of radiation-induced DNA double-strand breaks by nonhomologous end-joining and the clinical use of the substance, we investigated the relevance of the DNA-PK catalytic subunit (DNA-PKcs) for the modulation of cellular radiosensitivity by celecoxib. Methods and Materials: We used a syngeneic model of Chinese hamster ovarian cell lines: AA8, possessing a wild-type DNK-PKcs; V3, lacking a functional DNA-PKcs; and V3/WT11, V3 stably transfected with the DNA-PKcs. The cells were treated with celecoxib (50 {mu}M) for 24 h before irradiation. The modulation of radiosensitivity was determined using the colony formation assay. Results: Treatment with celecoxib increased the cellular radiosensitivity in the DNA-PKcs-deficient cell line V3 with a dose-enhancement ratio of 1.3 for a surviving fraction of 0.5. In contrast, clonogenic survival was increased in DNA-PKcs wild-type-expressing AA8 cells and in V3 cells transfected with DNA-PKcs (V3/WT11). The decrease in radiosensitivity was comparable to the radiosensitization in V3 cells, with a dose-enhancement ratio of 0.76 (AA8) and 0.80 (V3/WT11) for a survival of 0.5. Conclusions: We have demonstrated a DNA-PKcs-dependent differential modulation of cellular radiosensitivity by celecoxib. These effects might be attributed to alterations in signaling cascades downstream of DNA-PK toward cell survival. These findings offer an explanation for the poor outcomes in some recently published clinical trials.

  8. Fluorescence quenching analysis of the association and dissociation of a diarylheterocycle to cyclooxygenase-1 and cyclooxygenase-2: dynamic basis of cyclooxygenase-2 selectivity.

    PubMed

    Lanzo, C A; Sutin, J; Rowlinson, S; Talley, J; Marnett, L J

    2000-05-23

    Cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) are the enzymes responsible for the biosynthesis of the precursor to the biologically active prostaglandins, prostacyclin, and thromboxane and are the molecular targets for nonsteroidal antiinflammatory drugs (NSAIDs). Selective COX-2 inhibitors are antiinflammatory and analgesic but lack gastrointestinal toxicity, an undesirable side effect attributed to COX-1 inhibition. Crystallographic analysis of selective COX inhibitors complexed with either isoform provides some information about the molecular determinants of selectivity but does not provide information about the dynamics of inhibitor association/dissociation. We employed rapid-mixing techniques and fluorescence quenching to monitor the association and dissociation of a selective COX-2 inhibitor to COX-1 or COX-2. The association of the fluorescent diaryloxazole, SC299, with both enzymes occurs in a time-dependent fashion. Its binding to COX-2 occurs in three kinetically distinct steps whereas its binding to COX-1 occurs in two steps. In contrast to the relatively rapid association of SC299 with both enzymes, its dissociation from COX-2 is quite slow and occurs over several hours whereas the dissociation from COX-1 is complete in less than 1 min. The selectivity of SC299 as a COX-2 inhibitor correlates to its relative rates of dissociation from the two COX isoforms. A model is proposed for diarylheterocycle binding to COX's that integrates these kinetic data with available structural information.

  9. Cyclooxygenase-2 expression in the hereditary mixed polyposis syndrome.

    PubMed

    Brazowski, Eli; Misonzhnick-Bedny, Faina; Rozen, Paul

    2004-01-01

    Hereditary mixed polyposis syndrome (HMPS), characterized by hyperplastic, juvenile, admixed, serrated adenomas and eventually colorectal cancer, is managed by repeated polypectomy and surgery. We determined if HMPS polyps express cyclooxygenase-2 (COX-2). Nineteen recent HMPS polyps, from five family members, were stained for COX-2. Polyps' epithelium and stroma and comparison tissues (normal colonic mucosa [9], sporadic juvenile polyps [18], colorectal cancers [3]) were quantified for COX-2 by: area of staining (0-3) x intensity (0-3). Epithelial, stromal, and total scores were evaluated in relationship to histology and dysplasia. HMPS polyps COX-2 mean epithelial (5.0+/-3.0), stromal (6.9+/-1.9), and total (11.8+/-4.6) scores were significantly higher (P < 0.01) than sporadic juvenile polyps (0.6+/-0.7, 3.1+/-2.2, and 3.6+/- 2.2 respectively), while colorectal cancer scored 9, 9, and 18. There was a positive association (P < 0.01) among histology, degree of dysplasia, and COX-2 expression. COX-2 expression in HMPS polyps and its association with dysplasia suggest that chemoprevention might be a useful adjunct therapy.

  10. Eugenol suppresses cyclooxygenase-2 expression in lipopolysaccharide-stimulated mouse macrophage RAW264.7 cells.

    PubMed

    Kim, Sun Suk; Oh, O-Jin; Min, Hye-Young; Park, Eun-Jung; Kim, Youngleem; Park, Hyen Joo; Nam Han, Yong; Lee, Sang Kook

    2003-06-01

    Inducible cyclooxygenase (COX-2) has been implicated in the processes of inflammation and carcinogenesis. Thus, the potential COX-2 inhibitors have been considered as anti-inflammatory or cancer chemopreventive agents. In this study, the methanolic extract of the cortex of Eugenia caryophyllata Thunberg (Myrtaceae) was found to potently inhibit the prostaglandin E(2) production in lipopolysaccharide (LPS)-activated mouse macrophage RAW264.7 cells (98.3% inhibition at the test concentration of 10 microg/ml). Further, hexane-soluble layer was the most active partition compared to ethyl acetate, n-butanol, and water-soluble parts. By bioassay-guided fractionation of hexane-soluble partition, eugenol was isolated and exhibited a significant inhibition of PGE(2) production (IC(50) = 0.37 microM). In addition, eugenol suppressed the cyclooxygenase-2 (COX-2) gene expression in LPS-stimulated mouse macrophage cells. On the line of COX-2 playing an important role in colon carcinogenesis further study was designed to investigate the effect of eugenol on the growth and COX-2 expression in HT-29 human colon cancer cells. Eugenol inhibited the proliferation of HT-29 cells and the mRNA expression of COX-2, but not COX-1. This result suggests that eugenol might be a plausible lead candidate for further developing the COX-2 inhibitor as an anti-inflammatory or cancer chemopreventive agent.

  11. Cyclooxygenase-2 Mediates Dialysate-Induced Alterations of the Peritoneal Membrane

    PubMed Central

    Aroeira, Luiz S.; Lara-Pezzi, Enrique; Loureiro, Jesús; Aguilera, Abelardo; Ramírez-Huesca, Marta; González-Mateo, Guadalupe; Pérez-Lozano, M. Luisa; Albar-Vizcaíno, Patricia; Bajo, M-Auxiliadora; del Peso, Gloria; Sánchez-Tomero, José Antonio; Jiménez-Heffernan, José Antonio; Selgas, Rafael; López-Cabrera, Manuel

    2009-01-01

    During peritoneal dialysis (PD), exposure of the peritoneal membrane to nonphysiologic solutions causes inflammation, ultimately leading to altered structure and function. Myofibroblasts, one of the cell types that contribute to dysfunction of the peritoneal membrane, can originate from mesothelial cells (MCs) by epithelial-to-mesenchymal transition (EMT), a process that has been associated with an increased rate of peritoneal transport. Because cyclooxygenase-2 (COX-2) is induced by inflammation, we studied the role of COX-2 in the deterioration of the peritoneal membrane. We observed that nonepithelioid MCs found in peritoneal effluent expressed higher levels of COX-2 than epithelioid MCs. The mass transfer coefficient for creatinine correlated with MC phenotype and with COX-2 levels. Although COX-2 was upregulated during EMT of MCs in vitro, COX-2 inhibition did not prevent EMT. In a mouse model of PD, however, COX-2 inhibition with Celecoxib resulted in reduced fibrosis and in partial recovery of ultrafiltration, outcomes that were associated with a reduction of inflammatory cells. Furthermore, PD fluid with a low content of glucose degradation products did not induce EMT or COX-2; the peritoneal membranes of mice treated with this fluid showed less worsening than mice exposed to standard fluid. In conclusion, upregulation of COX-2 during EMT may mediate peritoneal inflammation, suggesting COX-2 inhibition as a potential strategy to ameliorate peritoneal deterioration in PD patients. PMID:19158357

  12. Selective cyclooxygenase-2 (COX-2) inhibitors reduce anti-Mycobacterium antibodies in adjuvant arthritic rats.

    PubMed

    Turull, A; Queralt, J

    2000-01-01

    Adjuvant arthritis, induced by Mycobacterium butyricum, is an experimental immunopathy that shares many features of human rheumatoid arthritis and, as such, is one of the most widely used models for studying the anti-inflammatory activity of compounds. In rats with adjuvant induced arthritis, IgG antibodies to M. butyricum have been detected and autoantigens that cross react with mycobacteria may be involved in the pathogenesis of adjuvant arthritis. In this study, the anti-inflammatory and immunosuppressive activities of two cyclooxygenase-2 selective inhibitors, flosulide and L-745,337, at doses of 0.1, 1 and 5 mg/kg/day, were examined in adjuvant arthritic rats. After 14 days of treatment, a clear dose-dependent inhibition of plantar edema was seen for both flosulide (ID50 lower than 0.1 mg/kg) and L-745,337 (ID50 = 0.4 mg/kg). Plasma levels of IgG anti-M. butyricum antibodies were also decreased by both drugs. In each case the maximal immunosuppressive effect was observed at doses lower than 5 mg/kg. The non-selective COX-2 inhibitor, indomethacin (1 mg/kg) decreased paw edema by 65% and the levels of IgG anti-M. butyricum by 45%. Neither cyclooxygenase selective inhibitors nor indomethacin decreased the delayed hypersensitivity reaction induced by M. butyricum. Thus, in vivo inhibition of COX-2 inhibited articular swelling and also the humoral immune response to Mycobacterium.

  13. Cyclooxygenase-2 and p53 expressions in endometrial cancer.

    PubMed

    Jeon, Yong-Tark; Kang, Sokbom; Kang, Dae-Hee; Yoo, Keun-Young; Park, In-Ae; Bang, Yung-Jue; Kim, Jae Weon; Park, Noh-Hyun; Kang, Soon-Beom; Lee, Hyo-Pyo; Song, Yong-Sang

    2004-09-01

    Cyclooxygenase-2 (COX-2) has been known to be related with various types of carcinoma, but we have insufficient knowledge about the association between COX-2 and endometrial cancer. Many have reported a close relationship between p53 expression and a poor prognosis in endometrial cancer, but it is unclear whether p53 is an independent prognostic factor. To clarify these uncertainties, we examined the expressions of COX-2 and p53 in endometrial cancer tissues. The study was carried on 152 endometrial cancer patients who had operation at Seoul National University Hospital. Paraffin-embedded tissue blocks were sectioned and immunostained using monoclonal anti-COX-2 and anti-p53 antibodies. Twenty-seven (17.8%) specimens stained as COX-2 positive. COX-2 positivity was more frequently observed in postmenopausal patients than in premenopausal patients (8.8% versus 25.0%; P = 0.009). However, COX-2 positivity did not show a statistically significant association with any other clinicopathologic characteristic (parity, body mass index, histotype, International Federation of Gynecology and Obstetrics stage, grade, lymph node metastasis, deep myometrial invasion, or p53 overexpression). Thirty-one (20.4%) specimens showed p53 overexpression and this was significantly correlated with an advanced stage (P = 0.001), poor differentiation (P < 0.001), lymph node metastasis (P = 0.012), and deep myometrial invasion (P < 0.001). Multivariate Cox regression analysis showed that advanced stage was an independent prognostic factor of survival, but p53 overexpression was not. COX-2 may be associated with endometrial cancer carcinogenesis during the postmenopausal period but not with tumor aggressiveness and p53 overexpression. The p53 overexpression was found to be strongly associated with endometrial cancer aggressiveness.

  14. Paeoniflorin ameliorates rheumatoid arthritis in rat models through oxidative stress, inflammation and cyclooxygenase 2

    PubMed Central

    JIA, ZHILIN; HE, JIAO

    2016-01-01

    Paeoniflorin has anti-inflammatory, anti-allergy, immune regulatory and pain-relieving effects, amongst other roles. However, the mechanisms underlying the protective effects of paeoniflorin on rheumatoid arthritis (RA) remain under investigation; the objective of the current study was to evaluate these protective effects in the context of an RA model. Rats were randomly divided into 5 groups, as follows: The control group, the RA rat model group, and the paeoniflorin groups, in which paeoniflorin was administered at concentrations of 5, 10 and 20 mg/kg for 3 weeks. The pain thresholds and arthritic symptoms of the RA rats were measured. Oxidative stress and inflammatory cytokines were also analyzed and western blot analysis was used to evaluate cyclooxygenase-2 (COX-2) protein expression levels. Paeoniflorin significantly increased the pain threshold and decreased the arthritic symptoms in the RA rat model. Notably, paeoniflorin reduced the malondialdehyde concentration and increased the activity of superoxide dismutase, catalase and glutathione peroxidase. Furthermore, paeoniflorin attenuated the activity of nuclear factor-κB p65 unit, tumor necrosis factor-α, interleukin (IL)-1β and IL-6, and reduced the COX-2 protein expression level. The present study indicates that paeoniflorin ameliorates disease in rat models of RA through oxidative stress, inflammation and alterations to COX-2 expression. PMID:26893662

  15. Targeted imaging of cancer by fluorocoxib C, a near-infrared cyclooxygenase-2 probe

    NASA Astrophysics Data System (ADS)

    Uddin, Md. Jashim; Crews, Brenda C.; Ghebreselasie, Kebreab; Daniel, Cristina K.; Kingsley, Philip J.; Xu, Shu; Marnett, Lawrence J.

    2015-05-01

    Cyclooxygenase-2 (COX-2) is a promising target for the imaging of cancer in a range of diagnostic and therapeutic settings. We report a near-infrared COX-2-targeted probe, fluorocoxib C (FC), for visualization of solid tumors by optical imaging. FC exhibits selective and potent COX-2 inhibition in both purified protein and human cancer cell lines. In vivo optical imaging shows selective accumulation of FC in COX-2-overexpressing human tumor xenografts [1483 head and neck squamous cell carcinoma (HNSCC)] implanted in nude mice, while minimal uptake is detectable in COX-2-negative tumor xenografts (HCT116) or 1483 HNSCC xenografts preblocked with the COX-2-selective inhibitor celecoxib. Time course imaging studies conducted from 3 h to 7-day post-FC injection revealed a marked reduction in nonspecific fluorescent signals with retention of fluorescence in 1483 HNSCC tumors. Thus, use of FC in a delayed imaging protocol offers an approach to improve imaging signal-to-noise that should improve cancer detection in multiple preclinical and clinical settings.

  16. Selective cyclooxygenase-2 (COX-2) inhibitors used for preventing or regressing cancer.

    PubMed

    de Souza Pereira, Ricardo

    2009-06-01

    The current use of antineoplastic drugs in human therapy causes a substancial number of toxic or side effects which consequently lead to a reduction of the amount of drug to be administered, and in some cases to discontinuation of the therapy. A reduction of the amount of drug to be administered or discontinuation of the therapy causes an increase in primary tumour growth and/or the occurrence of tumour metastases. For this reason, the development of new anti-cancer drugs with lower side effects is necessary. This review gives a general idea about the origins of cancer and the importance of cyclooxygenase-2 (COX-2) in oncogenesis. Evidence from clinical and preclinical studies indicates that COX-2-derived prostaglandins participate in carcinogenesis, inflammation, immune response suppression, apoptosis inhibition, angiogenesis, and tumour cell invasion and metastasis. The recent anti-tumour drugs are based on tests of known selective COX-2 inhibitors and on the drawing and synthesis of new potent derivatives. Maybe, this can be the way to obtain new anti-tumour drugs with very low collateral effects. Selective COX-2 inhibitors are being mixtured with new anti-cancer drugs in order to obtain better results in the regression of cancers. Some natural products are selective COX-2 inhibitors and have anti-inflammatory and anti-cancer properties. The relevant patents are discussed.

  17. Study of osteoarthritis treatment with anti-inflammatory drugs: cyclooxygenase-2 inhibitor and steroids.

    PubMed

    Cho, Hongsik; Walker, Andrew; Williams, Jeb; Hasty, Karen A

    2015-01-01

    Patients with osteoarthritis (OA), a condition characterized by cartilage degradation, are often treated with steroids, nonsteroidal anti-inflammatory drugs (NSAIDs), and cyclooxygenase-2 (COX-2) selective NSAIDs. Due to their inhibition of the inflammatory cascade, the drugs affect the balance of matrix metalloproteinases (MMPs) and inflammatory cytokines, resulting in preservation of extracellular matrix (ECM). To compare the effects of these treatments on chondrocyte metabolism, TNF-α was incubated with cultured chondrocytes to mimic a proinflammatory environment with increasing production of MMP-1 and prostaglandin E2 (PGE2). The chondrocytes were then treated with either a steroid (prednisone), a nonspecific COX inhibitor NSAID (piroxicam), or a COX-2 selective NSAID (celecoxib). Both prednisone and celecoxib decreased MMP-1 and PGE-2 production while the nonspecific piroxicam decreased only the latter. Both prednisone and celecoxib decreased gene expression of MMP-1 and increased expression of aggrecan. Increased gene expression of type II collagen was also noted with celecoxib. The nonspecific piroxicam did not show these effects. The efficacy of celecoxib in vivo was investigated using a posttraumatic OA (PTOA) mouse model. In vivo, celecoxib increases aggrecan synthesis and suppresses MMP-1. In conclusion, this study demonstrates that celecoxib and steroids exert similar effects on MMP-1 and PGE2 production in vitro and that celecoxib may demonstrate beneficial effects on anabolic metabolism in vivo.

  18. In vivo glucocorticoids regulate cyclooxygenase-2 but not cyclooxygenase-1 in peritoneal macrophages.

    PubMed

    Masferrer, J L; Reddy, S T; Zweifel, B S; Seibert, K; Needleman, P; Gilbert, R S; Herschman, H R

    1994-09-01

    Acute inflammatory stimuli elevate both the production of prostaglandins and the synthesis and activity of prostaglandin synthase/cyclooxygenase enzyme (COX) in murine peritoneal macrophages. Adrenalectomy also elevates prostaglandin production, COX synthesis and COX activity in these cells. We have utilized cDNA probes and antisera specific for the products of the prostaglandin synthase/cyclooxygenase-1 (COX-1) and TIS10/prostaglandin synthase-2/cyclooxygenase-2 (COX-2) genes to demonstrate that adrenalectomy causes elevation of mRNA and protein from the COX-2 gene, but not from the COX-1 gene, in peritoneal macrophages. Dexamethasone replacement suppressed the elevation of COX-2 mRNA message, COX-2 protein and the increased COX enzyme activity observed in adrenalectomized animals. In contrast, both COX-1 message and COX-1 protein levels were unaffected either by adrenalectomy or by dexamethasone administration. Thus, under normal physiological conditions, tonic glucocorticoid inhibition appears to play a major role in the in vivo regulation of the COX-2 gene. These data are consistent with COX-1 being the constitutive, housekeeping enzyme in macrophages in normal physiological conditions and with the enhanced prostaglandin synthesis seen after an inflammatory stimulus resulting from the rapid induction and activity of COX-2.

  19. A selective inhibitor of cyclooxygenase-2 reverses endotoxin-induced pyretic responses in non-human primates.

    PubMed

    Chan, C C; Panneton, M; Taylor, A M; Therien, M; Rodger, I W

    1997-05-30

    The anti-pyretic effect of a selective cyclooxygenase-2 inhibitor, DFU (5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulfonyl)phenyl-2(5H)-furano ne), was examined in conscious, un-restrained squirrel monkeys (Saimiri sciureus) using a radio telemetric system. Injection of bacterial endotoxin (lipopolysaccharide, 6 microg kg(-1), i.v.) in squirrel monkeys caused a gradual increase in core body temperature reaching a plateau of 2.07 +/- 0.17 degrees C above baseline at 2 h post-injection. Oral administration of DFU (1 mg kg(-1)) reduced, and DFU (3 mg kg(-1)) completely reversed the lipopolysaccharide-induced pyretic responses. The onset of action of DFU (about 30 min) is in good agreement with the pharmacokinetic profile of this compound in squirrel monkeys. The effect of DFU is comparable to that of a conventional non-selective non-steroidal anti-inflammatory drug (NSAID), diclofenac (3 mg kg(-1)). Since the plasma levels achieved for DFU at the dose employed in the present study are below the threshold required for inhibition of cyclooxygenase-1, it is concluded that the anti-pyretic effect of DFU can be attributed predominantly to an inhibitory action on cyclooxygenase-2. Thus, lipopolysaccharide-induced pyresis in squirrel monkeys can be used as a model for evaluation of anti-pyretic activity of cyclooxygenase inhibitors. PMID:9200563

  20. Nonsteroidal antiinflammatory drugs, cyclooxygenase-2, and the kidneys.

    PubMed

    Rahman, Saadur; Malcoun, Anthony

    2014-12-01

    Nonsteroidal antiinflammatory drugs (NSAIDs) are one of the most commonly used classes of medications in the world, which function by inhibiting the cyclooxygenase (COX) enzymes and downregulating the inflammatory pathway. COX enzymes are constitutively expressed in the kidneys and function to maintain a homeostatic environment in terms of maintaining the glomerular filtration rate, blood pressure, sodium, water, and osmotic regulation. When the COX enzymes are inhibited by NSAIDs, a multitude of renal and vascular complications occur. This article aims to enlighten primary care physicians of the complications that arise with NSAIDs from a renal perspective and to present some management strategies.

  1. Activating enhancer-binding protein-2α induces cyclooxygenase-2 expression and promotes nasopharyngeal carcinoma growth

    PubMed Central

    Qin, Lijun; Xie, Fangyun; Sun, Rui; Wang, Jingshu; Li, Wenbin; Liu, Tianze; Xiao, Yao; Yu, Wendan; Guo, Wei; Xiong, Yuqing; Qiu, Huijuan; Kang, Tiebang; Huang, Wenlin; Zhao, Chong; Deng, Wuguo

    2015-01-01

    Activating enhancer-binding protein-2α (AP-2α) regulates the expression of many cancer-related genes. Here, we demonstrated a novel mechanism by which AP-2α up-regulated cyclooxygenase-2 (COX-2) expression to promote the growth of nasopharyngeal carcinomas (NPCs). High expression of AP-2α in NPC cell lines and tumor tissues from NPC patients was detected and significantly correlated with COX-2 expression. Overexpression of AP-2α and COX-2 in tumor tissues was associated with advanced tumor stage, clinical progression, and short survival of patients with NPCs. Knockdown of AP-2α by siRNA markedly inhibited COX-2 expression and PGE2 production in NPC cells. Exogenous expression of AP-2α up-regulated the COX-2 and PGE2. Knockdown of AP-2α also significantly suppressed cell proliferation in NPC cells in vitro and tumor growth in a NPC xenograft mouse model. Moreover, we found that p300 played an important role in the AP-2α/COX-2 pathway. AP-2α could co-localize and interact with p300 in NPC cells. Overexpression of the p300, but not its histone acetyltransferase (HAT) domain deletion mutant, promoted the acetylation of AP-2α and its binding on the COX-2 promoter, thereby up-regulated COX-2 expression. Our results indicate that AP-2α activates COX-2 expression to promote NPC growth and suggest that the AP-2α/COX-2 signaling is a potential therapeutic target for NPC treatment. PMID:25669978

  2. Expression of Cyclooxygenase-2 in Human Transitional Cell Carcinoma of the Urinary Bladder

    PubMed Central

    Ristimäki, Ari; Nieminen, Outi; Saukkonen, Kirsi; Hotakainen, Kristina; Nordling, Stig; Haglund, Caj

    2001-01-01

    Recent studies suggest that expression of cyclooxygenase-2 (Cox-2) is elevated in transitional cell carcinoma (TCC) of the urinary bladder and that inhibition of Cox-2 activity suppresses bladder cancer in experimental animal models. We have investigated the expression of Cox-2 protein in human TCCs (n = 85), in in situ carcinomas (Tis) of the urinary bladder (n = 17), and in nonneoplastic urinary bladder samples (n = 16) using immunohistochemistry. Cox-2 immunoreactivity was detected in 66% (67 of 102) of the carcinomas, whereas only 25% (4 of 16) of the nonneoplastic samples were positive (P < 0.005). Cox-2 immunoreactivity localized to neoplastic cells in the carcinoma samples. The rate of positivity was the same in invasive (T1–3; 70%, n = 40) and in noninvasive (Tis and Ta; 65%, n = 62) carcinomas, but noninvasive tumors had a higher frequency (32%) of homogenous pattern of staining (>90% of the tumor cells positive) than the invasive carcinomas (10%) (P < 0.05). However, several invasive TCCs exhibited the strongest intensity of Cox-2 staining in the invading cells, whereas other parts of the tumor were virtually negative. Finally, strong Cox-2 positivity was also found in nonneoplastic ulcerations (2 of 2) and in inflammatory pseudotumors (2 of 2), in which the immunoreactivity localized to the nonepithelial cells. Taken together, our data suggest that Cox-2 is highly expressed in noninvasive bladder carcinomas, whereas the highest expression of invasive tumors associated with the invading cells, and that Cox-2 may also have a pathophysiological role in nonneoplastic conditions of the urinary bladder, such as ulcerations and inflammatory pseudotumors. PMID:11238034

  3. Interferon-α and cyclooxygenase-2 inhibitor cooperatively mediates TRAIL-induced apoptosis in hepatocellular carcinoma

    SciTech Connect

    Zuo, Chaohui; Qiu, Xiaoxin; Liu, Nianli; Yang, Darong; Xia, Man; Liu, Jingshi; Wang, Xiaohong; and others

    2015-05-01

    Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide. Interferon-alpha (IFN-α) has recently been recognized to harbor therapeutic potential in the prevention and treatment of HCC, but it remains controversial as to whether IFN-α exerts direct cytotoxicity against HCC. Cyclooxygenase-2 (COX-2) is overexpressed in HCC and is considered to play a role in hepatocarcinogenesis. Therefore, we aimed to elucidate the combined effect of a COX-2 inhibitor, celecoxib, and IFN-α on in vitro growth suppression of HCC using the hepatoma cell line HLCZ01 and the in vivo nude mouse xenotransplantation model using HLCZ01 cells. Treatment with celecoxib and IFN-α synergistically inhibited cell proliferation in a dose- and time-dependent manner. Apoptosis was identified by 4',6-diamidino-2-phenylindole dihydrochloride and fluorescent staining. IFN-α upregulated the expression of TRAIL, while celecoxib increased the expression of TRAIL receptors. The combined regimen with celecoxib and IFN-α reduced the growth of xenotransplanted HCCs in nude mice. The regulation of IFN-α- and COX-2 inhibitor-induced cell death is impaired in a subset of TRAIL-resistant cells. The molecular mechanisms of HCC cells resistant to TRAIL-induced apoptosis were explored using molecular biological and immunological methods. Interferon-α and the COX-2 inhibitor celecoxib synergistically increased TRAIL-induced apoptosis in hepatocellular carcinoma. These data suggest that IFN-α and celecoxib may offer a novel role with important implications in designing new therapeutics for TRAIL-resistant tumors. - Highlights: ●The cytotoxic effect of TRAIL on a developed HCC HLCZ01 cells infected with HBV. ●IFN-α and celecoxib induced apoptosis in HLCZ01 cells infected with HBV. ●The combined regime reduced the growth of xenotransplanted HCCs in nude mice model.

  4. Cholesterol affects flow-stimulated cyclooxygenase-2 expression and prostanoid secretion in the cortical collecting duct

    PubMed Central

    Liu, Yu; Flores, Daniel; Carrisoza-Gaytán, Rolando

    2015-01-01

    Essential hypertension (eHTN) is associated with hypercholesterolemia, but how cholesterol contributes to eHTN is unknown. Recent evidence demonstrates that short-term dietary cholesterol ingestion induces epithelial Na channel (ENaC)-dependent Na absorption with a subsequent rise in blood pressure (BP), implicating cholesterol in salt-sensitive HTN. Prostaglandin E2 (PGE2), an autocrine/paracrine molecule, is induced by flow in endothelia to vasodilate the vasculature and inhibit ENaC-dependent Na absorption in the renal collecting duct (CD), which reduce BP. We hypothesize that cholesterol suppresses flow-mediated cyclooxygenase-2 (COX-2) expression and PGE2 release in the CD, which, in turn, affects Na absorption. Cortical CDs (CCDs) were microperfused at 0, 1, and 5 nl·min−1·mm−1, and PGE2 release was measured. Secreted PGE2 was similar between no- and low-flow (151 ± 28 vs. 121 ± 48 pg·ml−1·mm−1) CCDs, but PGE2 was greatest from high-flow (578 ± 146 pg·ml−1·mm−1; P < 0.05) CCDs. Next, mice were fed either a 0 or 1% cholesterol diet, injected with saline to generate high urine flow rates, and CCDs were microdissected for PGE2 secretion. CCDs isolated from cholesterol-fed mice secreted less PGE2 and had a lower PGE2-generating capacity than CCDs isolated from control mice, implying cholesterol repressed flow-induced PGE2 synthesis. Next, cholesterol extraction in a CD cell line induced COX-2 expression and PGE2 release while cholesterol incorporation, conversely, suppressed their expression. Moreover, fluid shear stress (FSS) and cholesterol extraction induced COX-2 protein abundance via p38-dependent activation. Thus cellular cholesterol composition affects biomechanical signaling, which, in turn, affects FSS-mediated COX-2 expression and PGE2 release via a p38-dependent mechanism. PMID:25761882

  5. Resistance of cyclooxygenase-2 expressing pancreatic ductal adenocarcinoma cells against γδ T cell cytotoxicity

    PubMed Central

    Gonnermann, Daniel; Oberg, Hans-Heinrich; Kellner, Christian; Peipp, Matthias; Sebens, Susanne; Kabelitz, Dieter; Wesch, Daniela

    2015-01-01

    The prostaglandin (PG) synthetase cyclooxygenase 2 (Cox-2) promotes tumorigenesis, tumor progression, and metastasis in a variety of human cancer entities including pancreatic ductal adenocarcinoma (PDAC). In this study, we demonstrate that in PDAC cells such as Colo357 cells, enhanced Cox-2 expression and increased release of the Cox-2 metabolite prostaglandin E2 (PGE2) promotes resistance against γδ T cell-mediated lysis. Co-culture with activated γδ T cells induced an upregulation of Cox-2 expression in Colo357 cells, and thereby an enhanced PGE2 release, in response to tumor necrosis factor α (TNFα) secretion from γδ T cells. The PGE2-mediated inhibition of γδ T cell cytotoxicity against Cox-2-expressing PDAC cells can be partially overcome by Cox-2 inhibitors. Our results show that differences between PDAC cells in regards to sensitivity to γδ T-cell cytotoxicity can be due to distinct levels of Cox-2 expression associated with varying amounts of PGE2 release. While γδ T cell cytotoxicity against PDAC cells expressing low levels of Cox-2 can be effectively enhanced by tribody [(Her2)2×Vγ9] with specificity for Vγ9 T cell receptor and HER-2/neu on PDAC cells, a combination of tribody [(Her2)2×Vγ9] and Cox-2 inhibitor is necessary to induce complete lysis of Cox-2 high expressing Colo357. In conclusion, our results suggest that the application of tribody [(Her2)2×Vγ9] that enhances γδ T-cell cytotoxicity and Cox-2 inhibitors that overcome PGE2-mediated resistance of PDAC cells to the cytotoxic activity of γδ T cells might offer a promising combined immunotherapy for pancreatic cancer. PMID:25949900

  6. Role of the cyclooxygenase 2-thromboxane pathway in 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced decrease in mesencephalic vein blood flow in the zebrafish embryo

    SciTech Connect

    Teraoka, Hiroki Kubota, Akira; Dong, Wu; Kawai, Yusuke; Yamazaki, Koji; Mori, Chisato; Harada, Yoshiteru; Peterson, Richard E.; Hiraga, Takeo

    2009-01-01

    Previously, we reported that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) evoked developmental toxicity required activation of aryl hydrocarbon receptor type 2 (AHR2), using zebrafish embryos. However, the downstream molecular targets of AHR2 activation are largely unknown and are the focus of the present investigation. TCDD induces cyclooxygenase 2 (COX2), a rate-limiting enzyme for prostaglandin synthesis in certain cells. In the present study, we investigated the role of the COX2-thromboxane pathway in causing a specific endpoint of TCDD developmental toxicity in the zebrafish embryo, namely, a decrease in regional blood flow in the dorsal midbrain. It was found that the TCDD-induced reduction in mesencephalic vein blood flow was markedly inhibited by selective COX2 inhibitors, NS-398 and SC-236, and by a general COX inhibitor, indomethacin, but not by a selective COX1 inhibitor, SC-560. Gene knock-down of COX2 by two different types of morpholino antisense oligonucleotides, but not by their negative homologs, also protected the zebrafish embryos from mesencephalic vein circulation failure caused by TCDD. This inhibitory effect of TCDD on regional blood flow in the dorsal midbrain was also blocked by selective antagonists of the thromboxane receptor (TP). Treatment of control zebrafish embryos with a TP agonist also caused a reduction in mesencephalic vein blood flow and it too was blocked by a TP antagonist, without any effect on trunk circulation. Finally, gene knock-down of thromboxane A synthase 1 (TBXS) with morpholinos but not by the morpholinos' negative homologs provided significant protection against TCDD-induced mesencephalic circulation failure. Taken together, these results point to a role of the prostanoid synthesis pathway via COX2-TBXS-TP in the local circulation failure induced by TCDD in the dorsal midbrain of the zebrafish embryo.

  7. Prostaglandin E2 EP3 receptor regulates cyclooxygenase-2 expression in the kidney

    PubMed Central

    Quiroz-Munoz, Mariana; Cuevas, Catherina A.; Cespedes, Carlos; Ferreri, Nicholas R.

    2012-01-01

    Cyclooxygenase-2 (COX-2) is constitutively expressed and highly regulated in the thick ascending limb (TAL). As COX-2 inhibitors (Coxibs) increase COX-2 expression, we tested the hypothesis that a negative feedback mechanism involving PGE2 EP3 receptors regulates COX-2 expression in the TAL. Sprague-Dawley rats were treated with a Coxib [celecoxib (20 mg·kg−1·day−1) or rofecoxib (10 mg·kg−1·day−1)], with or without sulprostone (20 μg·kg−1·day−1). Sulprostone was given using two protocols, namely, previous to Coxib treatment (prevention effect; Sulp7-Coxib5 group) and 5 days after initiation of Coxib treatment (regression effect; Coxib10-Sulp5 group). Immunohistochemical and morphometric analysis revealed that the stained area for COX-2-positive TAL cells (μm2/field) increased in Coxib-treated rats (Sham: 412 ± 56.3, Coxib: 794 ± 153.3). The Coxib effect was inhibited when sulprostone was used in either the prevention (285 ± 56.9) or regression (345 ± 51.1) protocols. Western blot analysis revealed a 2.1 ± 0.3-fold increase in COX-2 protein expression in the Coxib-treated group, an effect abolished by sulprostone using either the prevention (1.2 ± 0.3-fold) or regression (0.6 ± 0.4-fold vs. control, P < 0.05) protocols. Similarly, the 6.4 ± 0.6-fold increase in COX-2 mRNA abundance induced by Coxibs (P < 0.05) was inhibited by sulprostone; prevention: 0.9 ± 0.3-fold (P < 0.05) and regression: 0.6 ± 0.1 (P < 0.05). Administration of a selective EP3 receptor antagonist, L-798106, also increased the area for COX-2-stained cells, COX-2 mRNA accumulation, and protein expression in the TAL. Collectively, the data suggest that COX-2 levels are regulated by a novel negative feedback loop mediated by PGE2 acting on its EP3 receptor in the TAL. PMID:22622465

  8. Pharmacological separation between peripheral and central functions of cyclooxygenase-2 with CIAA, a novel cyclooxygenase-2 inhibitor.

    PubMed

    Okumura, Takako; Murata, Yoko; Hizue, Masanori; Matsuura, Tomomi; Naganeo, Rie; Kanai, Yoshihito; Murase, Akio; Sakakibara, Ayano; Fujita, Isami; Nakao, Kazunari

    2006-06-01

    There are many reports concerning the physiological and pathological involvement of cyclooxygenase (COX)-2 in the central nervous system and peripheral tissue cells. Selective COX-2 inhibitors that mainly distribute peripherally have not been reported thus far. Therefore central and peripheral roles of COX-2 remain classified pharmacologically. In this study, in vivo pharmacological profiles of CIAA ([6-chloro-2-(4-chlorobenzoyl)-1H-indol-3-yl]acetic acid), a novel selective COX-2 inhibitor which distributes at higher concentrations in plasma than in brain, were compared with those of well-known selective COX-2 inhibitors, celecoxib and rofecoxib. Additionally, the possibility of pharmacological separation between peripheral and central actions of COX-2 with the inhibitors was investigated. CIAA selectively inhibited COX-2 activity compared with COX-1 in in vitro assays with rat whole blood. The compound exhibited lower brain penetration and higher plasma concentration (the brain/plasma concentration ratio was approximately 0.02) than celecoxib and rofecoxib after oral administration. Therefore, CIAA is mainly expected to act peripherally. Edema and prostaglandin E2 (PGE2) production in Carrageenan-injected rat paws, and pyrexia and PGE2 production in the brain in lipopolysaccharide (LPS)-injected rats were measured in in vivo experiments. CIAA exhibited lower ratios of anti-pyretic/anti-edematous activities and of inhibitory activities of PGE2 production in brain/paw than those of celecoxib and rofecoxib, and these ratios well-reflected brain/plasma concentration ratios. In conclusion, we discovered a novel selective COX-2 inhibitor, CIAA, which distributes at higher concentrations in plasma than in brain, which would make possible the pharmacological separation of the peripheral and central functions of COX-2. PMID:16690052

  9. Modulation of Ionizing Radiation-Induced G{sub 2} Arrest by Cyclooxygenase-2 and its Inhibitor Celecoxib

    SciTech Connect

    Jun, Hyun Jung; Kim, Young Mee; Park, Soo Yeon; Park, Ji Sun; Lee, Eun Jung; Choi, Shin Ae; Pyo, Hongryull

    2009-09-01

    Purpose: Prolongation or attenuation of ionizing radiation (IR)-induced G{sub 2}-M arrest in cyclooxygenase-2 (COX-2) overexpressing or celecoxib-treated cells, respectively, has been previously observed. To better understand the molecular mechanisms involved, we investigated the molecules involved in G{sub 2} checkpoint pathways after treatment with IR {+-} celecoxib. Methods and Materials: Various molecules in the G{sub 2} checkpoint pathways were investigated in HCT-116-Mock and -COX-2 cells. Western blot, reverse transcriptase polymerase chain reaction, confocal microscopy, and fluorescence activated cell sorter (FACS) analyses were performed to investigate whether expression and activity of the ataxia telangiectasia and rad3-related (ATR) could be modulated by COX-2 and its selective inhibitors. Results: COX-2 overexpression increased expression and activity of ATR after IR exposure. Celecoxib downregulated ATR in all tested cell lines independent of COX-2 expression, but downregulation was greater in COX-2 overexpressing cells after cells were irradiated. Celecoxib pretreatment before radiation caused strongly inhibited G{sub 2} arrest. Conclusions: COX-2 appears to prolong IR-induced G{sub 2} arrest by upregulating ATR. Celecoxib downregulated ATR preferentially in irradiated COX-2 overexpressing cells. Celecoxib may radiosensitize cancer cells by inhibiting G{sub 2} arrest through ATR downregulation.

  10. Are cyclooxygenase-2 and nitric oxide involved in the dyskinesia of Parkinson's disease induced by l-DOPA?†

    PubMed Central

    Bortolanza, Mariza; Padovan-Neto, Fernando E.; Cavalcanti-Kiwiatkoski, Roberta; dos Santos-Pereira, Maurício; Mitkovski, Miso; Raisman-Vozari, Rita; Del-Bel, Elaine

    2015-01-01

    Inflammatory mechanisms are proposed to play a role in l-DOPA-induced dyskinesia. Cyclooxygenase-2 (COX2) contributes to inflammation pathways in the periphery and is constitutively expressed in the central nervous system. Considering that inhibition of nitric oxide (NO) formation attenuates l-DOPA-induced dyskinesia, this study aimed at investigating if a NO synthase (NOS) inhibitor would change COX2 brain expression in animals with l-DOPA-induced dyskinesia. To this aim, male Wistar rats received unilateral 6-hydroxydopamine microinjection into the medial forebrain bundle were treated daily with l-DOPA (21 days) combined with 7-nitroindazole or vehicle. All hemi-Parkinsonian rats receiving l-DOPA showed dyskinesia. They also presented increased neuronal COX2 immunoreactivity in the dopamine-depleted dorsal striatum that was directly correlated with dyskinesia severity. Striatal COX2 co-localized with choline-acetyltransferase, calbindin and DARPP-32 (dopamine-cAMP-regulated phosphoprotein-32), neuronal markers of GABAergic neurons. NOS inhibition prevented l-DOPA-induced dyskinesia and COX2 increased expression in the dorsal striatum. These results suggest that increased COX2 expression after l-DOPA long-term treatment in Parkinsonian-like rats could contribute to the development of dyskinesia. PMID:26009769

  11. Mercury induces proliferation and reduces cell size in vascular smooth muscle cells through MAPK, oxidative stress and cyclooxygenase-2 pathways

    SciTech Connect

    Aguado, Andrea; Galán, María; Zhenyukh, Olha; Wiggers, Giulia A.; Roque, Fernanda R.; Redondo, Santiago; Peçanha, Franck; Martín, Angela; Fortuño, Ana; Cachofeiro, Victoria; Tejerina, Teresa; Salaices, Mercedes; and others

    2013-04-15

    Mercury exposure is known to increase cardiovascular risk but the underlying cellular mechanisms remain undetermined. We analyzed whether chronic exposure to HgCl{sub 2} affects vascular structure and the functional properties of vascular smooth muscle cells (VSMC) through oxidative stress/cyclooxygenase-2 dependent pathways. Mesenteric resistance arteries and aortas from Wistar rats treated with HgCl{sub 2} (first dose 4.6 mg kg{sup −1}, subsequent doses 0.07 mg kg{sup −1} day{sup −1}, 30 days) and cultured aortic VSMC stimulated with HgCl{sub 2} (0.05–5 μg/ml) were used. Treatment of rats with HgCl{sub 2} decreased wall thickness of the resistance and conductance vasculature, increased the number of SMC within the media and decreased SMC nucleus size. In VSMCs, exposure to HgCl{sub 2}: 1) induced a proliferative response and a reduction in cell size; 2) increased superoxide anion production, NADPH oxidase activity, gene and/or protein levels of the NADPH oxidase subunit NOX-1, the EC- and Mn-superoxide dismutases and cyclooxygenase-2 (COX-2); 3) induced activation of ERK1/2 and p38 MAPK. Both antioxidants and COX-2 inhibitors normalized the proliferative response and the altered cell size induced by HgCl{sub 2}. Blockade of ERK1/2 and p38 signaling pathways abolished the HgCl{sub 2}-induced Nox1 and COX-2 expression and normalized the alterations induced by mercury in cell proliferation and size. In conclusion, long exposure of VSMC to low doses of mercury activates MAPK signaling pathways that result in activation of inflammatory proteins such as NADPH oxidase and COX-2 that in turn induce proliferation of VSMC and changes in cell size. These findings offer further evidence that mercury might be considered an environmental risk factor for cardiovascular disease. - Highlights: ► Chronic HgCl{sub 2} exposure induces vascular remodeling. ► HgCl{sub 2} induces proliferation and decreased cell size in vascular smooth muscle cells. ► HgCl{sub 2} induces

  12. Anti-inflammatory effects of essential oils from Chamaecyparis obtusa via the cyclooxygenase-2 pathway in rats.

    PubMed

    An, Beum-Soo; Kang, Ji-Houn; Yang, Hyun; Jung, Eui-Man; Kang, Hong-Seok; Choi, In-Gyu; Park, Mi-Jin; Jeung, Eui-Bae

    2013-07-01

    Essential oils are concentrated hydrophobic liquids containing volatile aromatic compounds from plants. In the present study, the essential oil of Chamaecyparis obtusa (C. obtusa), which is commercially used in soap, toothpaste and cosmetics, was extracted. Essential oil extracted from C. obtusa contains several types of terpenes, which have been shown to have anti-oxidative and anti-inflammatory effects. In the present study, we examined the anti-inflammatory effects of C. obtusa essential oil in vivo and in vitro following the induction of inflammation by lipopolysaccharides (LPS) in rats. While LPS induced an inflammatory response through the production of prostaglandin E2 (PGE2) in the blood and peripheral blood mononuclear cells (PMNCs), these levels were reduced when essential oil was pre-administered. Additionally, the mechanism of action underlying the anti-inflammatory effects of C. obtusa essential oil was investigated by measuring the mRNA expression of inflammation‑associated genes. LPS treatment significantly induced the expression of transforming growth factor α (TNFα) and cyclooxygenase-2 (COX-2) in rats, while C. obtusa essential oil inhibited this effect. Taken together, our results demonstrate that C. obtusa essential oil exerts anti‑inflammatory effects by regulating the production of PGE2 and TNFα gene expression through the COX-2 pathway. These findings suggest that C. obtusa essential oil may constitute a novel source of anti-inflammatory drugs.

  13. A Cyclooxygenase-2 Inhibitor Reduces Vascular Wall Thickness and Ameliorates Cognitive Impairment in a Cerebral Small Vessel Diseases Rat Model.

    PubMed

    Tang, Jie; Xiao, Weizhong; Li, Qinghua; Deng, Qiuqiong; Chu, Xinquan; Chen, Yang; Pan, Danhong; Fu, Jianhui

    2015-01-01

    Cerebral small vessel disease (CSVD) is a group of diseases that originate from changes in cerebral small vessels and that cause many conditions, such as cognitive impairment. However, there is no effective therapy for these diseases. Recent studies have suggested that inflammation is associated with this disease. Cyclooxygenase-2 (cox-2) is an inflammatory mediator; however, whether a cox-2 inhibitor could protect against the CSVD progression remains unknown. In the present study, stroke-prone spontaneously hypertensive rats (SHRsp) were used as a model of CSVD, and Sprague Dawley (SD) rats served as the control. SHRsp were treated with the cox-2 inhibitor celecoxib or vehicle. The Morris water maze test was performed, and vascular morphometry and the expression of collagen I and fibronectin were examined in cerebral small vessels and cerebral tissue. The results revealed that thickened small veesel walls, increased expression of collagen I and fibronectin and impaired cognitive function in SHRsp compared with SD rats. Additionally, celecoxib significantly down-regulated the expression of collagen I and fibronectin, attenuated the increase in vascular wall thickness and ameliorates the cognitive impairment. Our study indicated that this cox-2 inhibitor may serve as a promising candidate for the pharmacological intervention of CSVD. PMID:26159203

  14. Role of cyclooxygenase-2 in the development of interstitial fibrosis in kidneys following unilateral ureteral obstruction in mice.

    PubMed

    Kamata, Mariko; Hosono, Kanako; Fujita, Tomoe; Kamata, Kouju; Majima, Masataka

    2015-03-01

    Unilateral ureteral obstruction (UUO) induced tubulointerstitial fibrosis in kidneys mimics the pathogenesis of chronic kidney diseases and is considered a suitable model for studying the mechanisms leading to fibrosis. To study the role of cyclooxygenase-2 (COX-2) in kidney fibrosis, we investigated whether a selective COX-2 inhibitor, celecoxib, affected renal interstitial fibrosis during UUO in mice. To induce UUO, the left proximal ureter was ligated in male C57BL/6 mice. The mice were fed a diet with or without celecoxib from the day of UUO induction. Following UUO, the renal pelvis was observed to be dilated and the kidney cortex was significantly thinner than that of sham-operated mice. Immunofluorescent staining of type I, III, and IV collagen in UUO kidneys revealed that interstitial collagen deposition was significantly increased in the celecoxib-treated group. Expression of type I, III, and IV collagen in UUO kidneys was also significantly higher in the celecoxib-treated group than in the vehicle-treated group. In the celecoxib-treated group, mRNA levels of TGF-β/FGF-2 were also significantly higher than those in the vehicle-treated group. The present study demonstrates that COX-2 plays a protective role against fibrosis in UUO kidneys and suggests that supplementation of COX-2 products, such as PG analogues, will be a good option for preventing interstitial fibrosis. PMID:25776498

  15. Endogenous 2-Arachidonoylglycerol Alleviates Cyclooxygenases-2 Elevation-Mediated Neuronal Injury From SO2 Inhalation via PPARγ Pathway.

    PubMed

    Li, Ben; Chen, Minjun; Guo, Lin; Yun, Yang; Li, Guangke; Sang, Nan

    2015-10-01

    Although the health effects of sulfur dioxide (SO2) pollution in the atmospheric environment are not new, epidemiological studies and parallel experimental investigations indicate that acute SO2 exposure causes glutamate-mediated excitotoxicity and even contributes to the outcome of cerebral ischemia. Additionally, the free radical-related inflammatory responses are responsible for neuronal insults and consequent brain disorders. However, few medications are available for preventing the inflammatory responses and relieving the subsequent harmful insults from SO2 inhalation. Here, we show that endocannabinoid 2-arachidonoylglycerol (2-AG) prevents neurotoxicity from SO2 inhalation by suppressing cyclooxygenase-2 (COX-2) overexpression, and this action appears to be mediated via cannabinoid receptor 1 (CB1)-dependent mitogen-activated protein kinase/nuclear factor κB (NF-κB) signaling pathways. Furthermore, CB1-dependent peroxisome proliferator activated receptor γ (PPARγ) expression was an important modulator of the 2-AG-mediated resolution on NF-κB-coupled COX-2 elevation in response to SO2 neuroinflammation. This finding provides evidence of a possible therapeutic effect of endogenous 2-AG regulation for protecting against neurological dysfunction from SO2 inhalation in polluted areas.

  16. Genetic association of cyclooxygenase-2 gene polymorphisms with Parkinson’s disease susceptibility in Chinese Han population

    PubMed Central

    Dai, Yi; Wu, Yuquan; Li, Yansheng

    2015-01-01

    Objective: The aim of this study was to explore the genetic association of cyclooxygenase-2 (COX2) gene promoter region polymorphisms with Parkinson’s disease (PD) susceptibility in Chinese Han population. Methods: The genotyping of COX2 gene polymorphisms was conducted by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 122 patients with PD and 120 healthy persons. The association strength of gene polymorphism with disease was measured by odds ratio (OR) and 95% confidence interval (95% CI) calculated using χ2 test which also evaluated the Hardy-Weinberg equilibrium (HWE) of gene polymorphism in controls. The linkage disequilibrium and haplotype were also analyzed as evidence in the analysis of association. Results: On condition that the genotypes distributions of COX2 -1290A>G, -1195G>A, -765G>C in the control group all conformed to HWE, however, only the homozygous genotype AA of -1195G>A polymorphism showed an association with PD (OR=0.432, 95% CI=0.196-0.950). In addition, in haplotype analysis, G-A-C haplotype frequency in cases was significantly lower than the controls, compared with the common haplotype A-G-G (P=0.031, OR=0.375, 95% CI=0.149-0.940). Conclusions: COX2 -1195G>A polymorphism might play a protective role in the onset of PD and G-A-C haplotype in this three promoter region polymorphisms also showed a negative association. PMID:26722563

  17. Changes in rates of upper gastrointestinal hemorrhage after the introduction of cyclooxygenase-2 inhibitors in British Columbia and Ontario

    PubMed Central

    Mamdani, Muhammad; Warren, Leanne; Kopp, Alex; Paterson, J. Michael; Laupacis, Andreas; Bassett, Ken; Anderson, Geoffrey M.

    2006-01-01

    Background Population rates of upper gastrointestinal (GI) hemorrhage have been observed to increase with the introduction and rapid uptake of selective cyclooxygenase-2 (COX-2) inhibitors. Changes in COX-2 inhibitor use and upper GI bleeding rates in regions with relatively restrictive drug policies (e.g., British Columbia) have not been compared with changes in regions with relatively less restrictive drug policies (e.g., Ontario). Methods We collected administrative data for about 1.4 million people aged 66 years and older in British Columbia and Ontario for the period January 1996 to November 2002. We examined temporal changes in the prevalence of NSAID use and admissions to hospital because of upper GI hemorrhage in both provinces using cross-sectional time series analysis. Results During the period studied, the prevalence of NSAID use in British Columbia's population of older people increased by 25% (from 8.7% to 10.9%; p < 0.01), as compared with a 51% increase in Ontario (from 10.9% to 16.5%; p < 0.01). Hospital admissions because of upper GI hemorrhage increased significantly in Ontario by about 16% on average, or about 2 admissions per 10 000 elderly people, above expected values (p < 0.01). A similar increase was not observed in British Columbia. Interpretation More restrictive drug coverage policies, although limiting access to drugs and their potential benefits, may protect the population from adverse drug effects. PMID:17146090

  18. Deletion of cyclooxygenase-2 inhibits K-ras–induced lung carcinogenesis

    PubMed Central

    Pan, Yong; Jiang, Yan; Tan, Lin; K. Ravoori, Murali; Gagea, Mihai; Vikas Kundra, Vikus; Fischer, Susan M.; Yang, Peiying

    2015-01-01

    The purpose of this study was to identify the role COX-2 plays in K-ras–induced lung carcinogenesis. We crossed COX-2–homozygous knockout mice with K-rasLA1 (G12D) expressing mice to obtain COX-2–deficient mice with K-ras expression (K-ras/COX-2−/− mice) and COX-2 wild type mice with K-ras expression (K-ras mice). At 3.5 months of age, the K-ras/COX-2−/− mice had significantly fewer lung adenocarcinomas and substantially smaller tumors than K-ras mice. K-ras/COX-2−/− mice also had significantly fewer bronchioalveolar hyperplasias than K-ras mice. Compared with lung tumors from K-Ras mice, the levels of prostaglandin E2 (PGE2) were significantly lower, whereas levels of the PGE2 metabolite 13,14-dihydro-15-keto-PGE2 were significantly higher, in lung tumors from K-ras/COX-2−/− mice. In addition, K-ras/COX-2−/− mice had strikingly lower rates of tumor cell proliferation and expressed less MEK and p-Erk1/2 protein than K-ras mice did. In line with this, knocking down COX-2 in mutant K-ras non-small cell lung cancer A549 cells reduced colony formation, PGE2 synthesis and ERK phosphorylation compared to that of vector control cells. Taken together, these findings suggest that COX-2 deletion contributes to the repression of K-ras–induced lung tumorigenesis by reducing tumor cell proliferation, decreasing the production of PGE2, and increasing the production of 13,14-dihydro-15-keto-PGE2, possibly via the MAPK pathway. Thus, COX-2 is likely important in lung tumorigenesis, and COX-2 and its product, PGE2, are potential targets for lung cancer prevention. PMID:26452035

  19. Anti-inflammatory action of legume isoflavonoid sophoricoside through inhibition on cyclooxygenase-2 activity.

    PubMed

    Kim, Byung Hak; Chung, Eun Yong; Min, Bo-Kyung; Lee, Seung Ho; Kim, Mi-Kyeong; Min, Kyung Rak; Kim, Youngsoo

    2003-05-01

    Soy is a main source of isoflavonoids which are of high dietary intake for the oriental population. In this study, the anti-inflammatory action of sophoricoside, an isoflavone glycoside isolated from immature fruits of Sophora japonica L. (Leguminosae), has been demonstrated. When administered orally at > 100 mg/kg or injected intravenously at > 10 mg/kg, sophoricoside showed significant reduction of carrageenin-induced paw edema in mice. Sophoricoside has been identified as a selective inhibitor of cyclooxygenase (COX)-2 activity with an IC50 value of 3.3 microM. PMID:12802736

  20. Pro-migratory actions of the prostacyclin receptor in human breast cancer cells that over-express cyclooxygenase-2.

    PubMed

    Allison, Sarah E; Petrovic, Nenad; Mackenzie, Peter I; Murray, Michael

    2015-08-15

    Metastasis is the major cause of death in cancer patients. Elevated expression of cyclooxygenase-2 (COX-2) is observed in many human cancers and over-production of downstream prostaglandins (PGs) has been shown to stimulate metastasis. A role for increased PGE2 production has been proposed, but whether other PGs contribute is currently unclear. In this study the pro-migratory actions of individual PGs were evaluated in MDA-MB-468 breast cancer cells that stably over-expressed COX-2 (MDA-COX-2 cells); cell migration was quantified using 3D-matrigel droplet assays. Inhibition of the prostacyclin and PGE synthases, but not alternate prostanoid synthases, prevented the increase in MDA-COX-2 cell migration produced by arachidonic acid (AA); direct treatment of cells with the stable prostacyclin analogue cicaprost also promoted migration. Pharmacological antagonism and knockdown of the IP receptor decreased cell migration, while antagonists of the alternate DP, EP2, FP, and TP prostanoid receptors were inactive. In support of these findings, activation of the IP receptor also enhanced migration in the MDA-MB-468, MDA-MB-231 and A549 cell lines, and IP receptor knock-down in MDA-COX-2 cells decreased the expression of a number of pro-migratory genes. In further studies, the prostacyclin/IP receptor and PGE2/EP4 receptor pathways were found to be functionally independent and the inhibition of phosphatidylinositol 3-kinase (PI3K) and p38 mitogen-activated protein kinase (MAPK) selectively impaired the IP-receptor-dependent migration in MDA-COX-2 cells. Taken together, the prostacyclin/IP/PI3K-p38 MAPK axis has emerged as a novel pro-migratory pathway in breast cancer cells that over-express COX-2. This information could be utilized in novel treatment strategies to minimize tumor metastasis.

  1. Expression of cyclooxygenase-2 in cervical cancer is associated with lymphovascular invasion

    PubMed Central

    Hoellen, Friederike; Waldmann, Annika; Banz-Jansen, Constanze; Rody, Achim; Heide, Maria; Köster, Frank; Ribbat-Idel, Julika; Thorns, Christoph; Gebhard, Maximilian; Oberländer, Martina; Habermann, Jens K.; Thill, Marc

    2016-01-01

    Cyclooxygenase-2 (COX-2) is associated with carcinogenesis and tumor progression. The current study analyzed the effect of COX-2 expression in patients with invasive squamous cervical cancer. Tissue samples from 123 cervical cancer patients were collected for a retrospective analysis using immunohistochemistry (IHC) with an antibody against COX-2. The clinical and survival data of the patients were analyzed. Positive staining for COX-2 (defined as an immunoreactivity score of ≥4) was detected in 28 patients (23%), with significantly higher percentages of staining in tumor cells compared with peritumoral stroma cells (P<0.001). COX-2 expression was significantly associated with lymphovascular space invasion (LVSI; P=0.017). The association of COX-2 expression with LVSI suggests a possible effect of COX-2 on tumor progression in cervical cancer. Further studies including larger patient collectives are required in order to perform analyses of clinical subgroups and patient survival. PMID:27698799

  2. O-desmethylquinine as a cyclooxygenase-2 (COX-2) inhibitors using AutoDock Vina

    NASA Astrophysics Data System (ADS)

    Damayanti, Sophi; Mahardhika, Andhika Bintang; Ibrahim, Slamet; Chong, Wei Lim; Lee, Vannajan Sanghiran; Tjahjono, Daryono Hadi

    2014-10-01

    Computational approach was employed to evaluate the biological activity of novel cyclooxygenase-2 COX-2 inhibitor, O-desmethylquinine, in comparison to quinine as common inhibitor which can also be used an agent of antipyretic, antimalaria, analgesic and antiinflamation. The molecular models of the compound were constructed and optimized with the density function theory with at the B3LYP/6-31G (d,p) level using Gaussian 09 program. Molecular docking studies of the compounds were done to obtain the COX-2 complex structures and their binding energies were analyzed using the AutoDock Vina. The results of docking of the two ligands were comparable and cannot be differentiated from the energy scoring function with AutoDock Vina.

  3. Expression of cyclooxygenase-2 in cervical cancer is associated with lymphovascular invasion

    PubMed Central

    Hoellen, Friederike; Waldmann, Annika; Banz-Jansen, Constanze; Rody, Achim; Heide, Maria; Köster, Frank; Ribbat-Idel, Julika; Thorns, Christoph; Gebhard, Maximilian; Oberländer, Martina; Habermann, Jens K.; Thill, Marc

    2016-01-01

    Cyclooxygenase-2 (COX-2) is associated with carcinogenesis and tumor progression. The current study analyzed the effect of COX-2 expression in patients with invasive squamous cervical cancer. Tissue samples from 123 cervical cancer patients were collected for a retrospective analysis using immunohistochemistry (IHC) with an antibody against COX-2. The clinical and survival data of the patients were analyzed. Positive staining for COX-2 (defined as an immunoreactivity score of ≥4) was detected in 28 patients (23%), with significantly higher percentages of staining in tumor cells compared with peritumoral stroma cells (P<0.001). COX-2 expression was significantly associated with lymphovascular space invasion (LVSI; P=0.017). The association of COX-2 expression with LVSI suggests a possible effect of COX-2 on tumor progression in cervical cancer. Further studies including larger patient collectives are required in order to perform analyses of clinical subgroups and patient survival.

  4. Cyclooxygenase-2 (COX-2) expression in high-risk premalignant oral lesions.

    PubMed

    Sudbø, Jon; Ristimäki, Ari; Sondresen, Jan Erik; Kildal, Wanja; Boysen, Morten; Koppang, Hanna S; Reith, Albrecht; Risberg, Björn; Nesland, Jahn M; Bryne, Magne

    2003-07-01

    Emerging data indicate a link between genetic instability and up-regulation of cyclooxygenase-2 (COX-2). To see if individuals at high risk of oral cancer are candidates for treatment with selective COX-2 inhibitors (coxibs), levels of COX-2 expression in healthy, premalignant and cancerous oral mucosa were compared with the occurrence of DNA ploidy status as a genetic risk marker of oral cancer. COX-2 gene product was evaluated immunohistochemically in 30 healthy persons, in 22 patients with dysplastic lesions without previous or concomitant carcinomas, and in 29 patients with oral carcinomas. The immunohistochemical findings were verified by western blotting. COX-2 expression was correlated to DNA content as a genetic risk marker of oral cancer. COX-2 was up-regulated from healthy to premalignant to cancerous oral mucosa. Thus, COX-2 expression was found in 1 case of healthy oral mucosa (3%). All specimens from healthy mucosa had a normal DNA content. In patients with premalignancies. In 29 patients with oral carcinomas, cyclooxygenase-2 expression was observed in 26 (88%), and aneuploidy was observed in 25 cases (94%, P=0.04). Notably, of 22 patients with dysplastic lesions, COX-2 was exclusively expressed in a subgroup of nine patients (41%) identified to be at high risk of cancer by the aberrant DNA content of their lesions. Seven of these patients were followed for 5 years or more. An oral carcinoma developed in six of them (85%; P=0.02). These findings emphasize the need to determine whether coxibs can reduce the risk of oral cancer in patients with high-risk precancerous lesions. PMID:12747975

  5. c-Jun N-terminal kinase negatively regulates epidermal growth factor-induced cyclooxygenase-2 expression in oral squamous cell carcinoma cell lines.

    PubMed

    Husvik, Camilla; Bryne, Magne; Halstensen, Trond S

    2009-12-01

    Epidermal growth factor (EGF)-induced cyclooxygenase-2 (COX-2) expression in squamous cell carcinomas is mediated through the extracellular signal-regulated kinase 1/2 and p38 pathways. Examination of a basaloid and a conventional oral squamous cell carcinoma cell line revealed that inhibition of c-Jun N-terminal kinase (JNK) with SP600125 increased EGF-induced (but not basal) COX-2 transcription 1.5-1.9-fold in extracellular signal-regulated kinase 1/2 and p38 pathway-dependent manners. Although JNK may phosphorylate the cyclosporine A-sensitive transcription factor, nuclear factor of activated T cells c3, it was seemingly not involved because cyclosporine A did not reduce EGF-induced COX-2 expression. Thus, JNK negatively regulated EGF-induced extracellular signal-regulated kinase 1/2 and/or p38-mediated COX-2 transcription, presumably through activating an unidentified phosphatase. PMID:20121928

  6. Parathyroid hormone induction of cyclooxygenase-2 in murine osteoblasts: role of the calcium-calcineurin-NFAT pathway.

    PubMed

    Huang, Hechang; Chikazu, Daichi; Voznesensky, Olga S; Herschman, Harvey R; Kream, Barbara E; Drissi, Hicham; Pilbeam, Carol C

    2010-04-01

    Murine MC3T3-E1 and MC-4 cells were stably transfected with -371/+70 bp of the murine cyclooxygenase-2 (COX-2) promoter fused to a luciferase reporter (Pluc371) or with Pluc371 carrying site-directed mutations. Mutations were made in (1) the cAMP response element (CRE) at -57/-52 bp, (2) the activating protein-1 (AP-1)-binding site at -69/-63 bp, (3) the nuclear factor of activated T-cells (NFAT)-binding site at -77/-73 bp, and (4) both the AP-1 and NFAT sites, which comprise a composite consensus sequence for NFAT/AP-1. Single mutation of CRE, AP-1, or NFAT sites decreased parathyroid hormone (PTH)-stimulated COX-2 promoter activity 40% to 60%, whereas joint mutation of NFAT and AP-1 abrogated the induction. On electrophoretic mobility shift analysis, PTH stimulated binding of phosphorylated CREB to an oligonucleotide spanning the CRE and binding of NFATc1, c-Fos, and c-Jun to an oligonucleotide spanning the NFAT/AP-1 composite site. Mutation of the NFAT site was less effective than mutation of the AP-1 site in competing binding to the composite element, suggesting that cooperative interactions of NFATc1 and AP-1 are more dependent on NFAT than on AP-1. Both PTH and forskolin, an activator of adenylyl cyclase, stimulated NFATc1 nuclear translocation. PTH- and forskolin-stimulated COX-2 promoter activity was inhibited 56% to 80% by calcium chelation or calcineurin inhibitors and 60% to 98% by protein kinase A (PKA) inhibitors. These results indicate an important role for the calcium-calcineurin-NFAT signaling pathway in the PTH induction of COX-2 and suggest that cross-talk between the cAMP/PKA pathway and the calcium-calcineurin-NFAT pathway may play a role in other functions of PTH in osteoblasts.

  7. Etodolac, a cyclooxygenase-2 inhibitor, attenuates paclitaxel-induced peripheral neuropathy in a mouse model of mechanical allodynia.

    PubMed

    Ito, Sunao; Tajima, Koyuki; Nogawa, Masaki; Inoue, Naoki; Kyoi, Takashi; Takahashi, Yosuke; Sasagawa, Takahiro; Nakamura, Akio; Kotera, Takashi; Ueda, Makoto; Yamashita, Yasuhiro; Banno, Kouji

    2012-07-01

    The effect of the cyclooxygenase-2 (COX-2) inhibitor etodolac on the mechanical allodynia induced by paclitaxel was investigated in mice and compared with the effects of the nonselective COX inhibitors indomethacin and diclofenac, the selective COX-2 inhibitor celecoxib, the calcium channel α(2)δ subunit inhibitor pregabalin, the sodium channel blocker mexiletine, and the serotonin-norepinephrine reuptake inhibitor duloxetine. The decrease in the paw-withdrawal threshold induced by paclitaxel was reversed by oral administration of etodolac at 10 mg/kg but was not affected by indomethacin, diclofenac, or celecoxib. The antiallodynic effect of etodolac gradually increased during repeated administration, and after 2 weeks the paw-withdrawal threshold at the preadministration point was significantly increased. Pregabalin, duloxetine, and mexiletine also showed an antiallodynic effect in this model. Whereas pregabalin had a preadministration effect similar to that of etodolac during repeated administration, mexiletine or duloxetine had no such effect. There was almost no difference in the distribution of etodolac and diclofenac in nervous tissue, indicating that COX inhibition is unlikely to be involved in the antiallodynic effect of etodolac. Etodolac did not show a neuroprotective effect against morphological transformations such as the axonal degeneration induced by paclitaxel. Instead, etodolac probably acts at the level of functional changes accompanying paclitaxel treatment, such as alterations in the activation state of components of the pain transmission pathway. Our findings suggest that etodolac attenuates paclitaxel-induced peripheral neuropathy by a COX-independent pathway and that it might be useful for the treatment of paclitaxel-induced peripheral neuropathy. PMID:22460833

  8. Phosphorylation of STAT3 mediates the induction of cyclooxygenase-2 by cortisol in the human amnion at parturition.

    PubMed

    Wang, Wangsheng; Guo, Chunming; Zhu, Ping; Lu, Jiangwen; Li, Wenjiao; Liu, Chao; Xie, Huiliang; Myatt, Leslie; Chen, Zi-Jiang; Sun, Kang

    2015-10-27

    The induction of cyclooxygenase-2 (COX-2) and subsequent production of prostaglandin E2 (PGE2) by cortisol in the amnion contrast with the effect of cortisol on most other tissues, but this proinflammatory effect of cortisol may be a key event in human parturition (labor). We evaluated the underlying mechanism activated by cortisol in primary human amnion fibroblasts. Exposure of the amnion fibroblasts to cortisol led to the activation of the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway, which induced the phosphorylation of the kinase SRC and STAT3 (signal transducer and activator of transcription 3). STAT3 interacted with the glucocorticoid receptor (GR) and the transcription factor CREB-1 (cAMP response element-binding protein 1) at the promoter of the gene encoding COX-2, which promoted the production of the secreted prostaglandin PGE2. PGE2 activates the prostaglandin receptors EP2 and EP4, which stimulate cAMP-PKA signaling. Thus, cortisol reinforced the activation of cAMP-PKA signaling through an SRC-STAT3-COX-2-PGE2-mediated feedback loop. Inhibiting STAT3, SRC, or the cAMP-PKA pathway attenuated the cortisol-stimulated induction of COX-2 and PGE2 production in amnion fibroblasts. In human amnion tissue, the amount of phosphorylated STAT3 correlated positively with that of cortisol, COX-2, and PGE2, and all were more abundant in tissue obtained after active labor than in tissue obtained from cesarean surgeries in the absence of labor. These results indicated that the coordinated recruitment of STAT3, CREB-1, and GR to the promoter of the gene encoding COX-2 contributes to the feed-forward induction of COX-2 activity and prostaglandin synthesis in the amnion during parturition.

  9. Effect of quercetin on metallothionein, nitric oxide synthases and cyclooxygenase-2 expression on experimental chronic cadmium nephrotoxicity in rats

    SciTech Connect

    Morales, Ana I.; Vicente-Sanchez, Cesar; Jerkic, Mirjana; Santiago, Jose M.; Sanchez-Gonzalez, Penelope D.; Perez-Barriocanal, Fernando; Lopez-Novoa, Jose M. . E-mail: jmlnovoa@usal.es

    2006-01-15

    Inflammation can play a key role in Cd-induced dysfunctions. Quercetin is a potent oxygen free radical scavenger and a metal chelator. Our aim was to study the effect of quercetin on Cd-induced kidney damage and metallothionein expression. The study was performed in Wistar rats that were administered during 9 weeks with either cadmium (1.2 mg Cd/kg/day, s.c.), quercetin (50 mg/kg/day, i.p.) or cadmium + quercetin. Renal toxicity was evaluated by measuring blood urea nitrogen concentration and urinary excretion of enzymes marker of tubular damage. Endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) renal expression were assessed by Western blot. Renal expression of metallothionein 1 and 2 (MT-1, MT-2) and eNOS mRNA was assessed by Northern blot. Our data demonstrated that Cd-induced renal toxicity was markedly reduced in rats that also received quercetin. MT-1 and MT-2 mRNA levels in kidney were substantially increased during treatment with Cd, being even higher when the animals received Cd and quercetin. Renal eNOS expression was significantly higher in rats receiving Cd and quercetin than in animals receiving Cd alone or in control rats. In the group that received Cd, COX-2 and iNOS expression was markedly higher than in control rats. In the group Cd + quercetin, no changes in COX-2 and iNOS expression were observed compared with the control group. Our results demonstrate that quercetin treatment prevents Cd-induced overexpression of iNOS and COX-2, and increases MT expression. These effects can explain the protection by quercetin of Cd-induced nephrotoxicity.

  10. Cyclooxygenase-2 inhibitors and most traditional nonsteroidal anti-inflammatory drugs cause similar moderately increased risks of cardiovascular disease.

    PubMed

    Hennekens, Charles H; Borzak, Steven

    2008-03-01

    Cyclooxygenase-2 inhibitors relieve pain from inflammatory conditions by decreasing the gastrointestinal side effects from traditional nonsteroidal anti-inflammatory drugs. Basic research provided plausible mechanisms and some observational epidemiological studies, case-control and cohort, indicated that patients prescribed with cyclooxygenase-2 inhibitors and nonsteroidal anti-inflammatory drugs had increased risks for myocardial infarction and stroke. Because patients prescribed with cyclooxygenase-2 inhibitors were systematically different, uncontrolled and uncontrollable confounding by indication was as large as the observed risks. Thus, epidemiological studies or their meta-analyses could not discern whether, and if so, how much, the risks were real. A comprehensive meta-analysis of randomized trials indicated that cyclooxygenase-2 inhibitors increased the risk of vascular events by 42%, almost exclusively myocardial infarction, as did high-dose regimens of ibuprofen and diclofenac, but not naproxen. Individual clinical judgments and policy decisions should include cardiovascular disease and noncardiovascular disease risks including gastrointestinal side effects and clinical benefits including improved quality of life from less pain and disability.

  11. Protection from Latent Inhibition Provided by a Conditioned Inhibitor

    PubMed Central

    McConnell, Bridget L.; Wheeler, Daniel S.; Urcelay, Gonzalo P.; Miller, Ralph R.

    2009-01-01

    Two conditioned suppression experiments with rats investigated the influence on latent inhibition of compounding a Pavlovian conditioned inhibitor with the target cue during preexposure treatment. Results were compared to subjects that received conventional latent inhibition training, no preexposure, or preexposure to the target cue in compound with a neutral stimulus. In Experiment 1, greater attenuation of the latent inhibition effect was observed in subjects that received target preexposure in compound with a Pavlovian conditioned inhibitor relative to subjects that received preexposure with a neutral stimulus or to the target alone. In Experiment 2, this protection from latent inhibition was attenuated if the excitor that was used to train the conditioned inhibitor was extinguished between preexposure and target training. The results are consistent with an account offered by the extended comparator hypothesis. PMID:19839702

  12. A prostaglandin E (PGE) receptor EP4 antagonist protects natural killer cells from PGE2-mediated immunosuppression and inhibits breast cancer metastasis.

    PubMed

    Ma, Xinrong; Holt, Dawn; Kundu, Namita; Reader, Jocelyn; Goloubeva, Olga; Take, Yukinori; Fulton, Amy M

    2013-01-01

    Cyclooxygenase-2 is frequently upregulated in epithelial tumors and contributes to poor outcomes in multiple malignancies. The COX-2 product prostaglandin E2 (PGE2) promotes tumor growth and metastasis by acting on a family of four G protein-coupled receptors (EP1-4). Using a novel small molecule EP4 antagonist (RQ-15986) and a syngeneic murine model of metastatic breast cancer, we determined the effect of EP4 blockade on innate immunity and tumor biology. Natural killer (NK)-cell functions are markedly depressed in mice bearing murine mammary tumor 66.1 or 410.4 cells owing to the actions of PGE2 on NK cell EP4 receptors. The EP4 agonist PGE1-OH inhibits NK functions in vitro, and this negative regulation is blocked by RQ-15986. Likewise, the treatment of tumor-bearing mice with RQ-15986 completely protected NK cells from the immunosuppressive effects of the tumor microenvironment in vivo. RQ-15986 also has direct effects on EP4 expressed by tumor cells, inhibiting the PGE2-mediated activation of adenylate cyclase and blocking PGE2-induced tumor cell migration. The pretreatment of tumor cells with a non-cytotoxic concentration of RQ-15986 inhibited lung colonization, a beneficial effect that was lost in mice depleted of NK cells. The oral administration of RQ-15986 inhibited the growth of tumor cells implanted into mammary glands and their spontaneous metastatic colonization to the lungs, resulting in improved survival. Our findings reveal that EP4 antagonism prevents tumor-mediated NK-cell immunosuppression and demonstrates the anti-metastatic activity of a novel EP4 antagonist. These observations support the investigation of EP4 antagonists in clinical trials.

  13. Role of cyclooxygenase-2 in deoxynivalenol-induced immunoglobulin a nephropathy.

    PubMed

    Jia, Qunshan; Pestka, James J

    2005-05-01

    Ingestion of the trichothecene mycotoxin deoxynivalenol (DON) induces serum IgA elevation and kidney mesangial IgA deposition in a manner that mimics the early stages of IgA nephropathy (IgAN), the most common human glomerulonephritis. Previous studies indicate that elevated interleukin-6 (IL-6) expression is crucial for this model and that DON induction of cyclooxygenase-2 (COX-2) might drive IL-6 upregulation. We hypothesized that COX-2 and its metabolites are essential for DON-induced IgAN and thus might be a suitable target for prophylaxis against aberrant IgA upregulation. DON feeding studies using COX-2 knockout mice or the COX-2 specific inhibitor, rofecoxib (Vioxx), were employed to test the hypothesis. Study 1 results demonstrated that DON consumption induced serum IgA and IgA-immune complex (IC) accumulation, IgA kidney deposition and splenic IgA secretion in wild-type mice. COX-2 deficiency did not affect upregulation of these parameters but rather, promoted DON-induced serum IgA elevation. Study 2 demonstrated that rofecoxib could not block DON-induced serum IgA, serum IgA-IC and mesangial IgA accumulation but instead increased enhanced serum IgA upregulation. These corroborating results suggest that COX-2 is not a requisite for DON-induced IgAN and furthermore, that COX-2 inhibitors such as rofecoxib would be contraindicated for the prevention of early stages of IgAN.

  14. Progressive Metaplastic and Dysplastic Changes in Mouse Pancreas Induced by Cyclooxygenase-2 Overexpression1

    PubMed Central

    Colby, Jennifer KL; Klein, Russell D; McArthur, Mark J; Conti, Claudio J; Kiguchi, Kaoru; Kawamoto, Toru; Riggs, Penny K; Pavone, Amy I; Sawicki, Janet; Fischer, Susan M

    2008-01-01

    Cyclooxygenase-2 (COX-2) overexpression is an established factor linking chronic inflammation with metaplastic and neoplastic change in various tissues. We generated transgenic mice (BK5.COX-2) in which elevation of COX-2 and its effectors trigger a metaplasia-dysplasia sequence in exocrine pancreas. Histologic evaluation revealed a chronic pancreatitis-like state characterized by acinar-to-ductal metaplasia and a well-vascularized fibroinflammatory stroma that develops by 3 months. By 6 to 8 months, strongly dysplastic features suggestive of pancreatic ductal adenocarcinoma emerge in the metaplastic ducts. Increased proliferation, cellular atypia, and loss of normal cell/tissue organization are typical features in transgenic pancreata. Alterations in biomarkers associated with human inflammatory and neoplastic pancreatic disease were detected using immunohistochemistry. The abnormal pancreatic phenotype can be completely prevented by maintaining mice on a diet containing celecoxib, a well-characterized COX-2 inhibitor. Despite the high degree of atypia, only limited evidence of invasion to adjacent tissues was observed, with no evidence of distant metastases. However, cell lines derived from spontaneous lesions are aggressively tumorigenic when injected into syngeneic or nude mice. The progressive nature of the metaplastic/dysplastic changes observed in this model make it a valuable tool for examining the transition from chronic inflammation to neoplasia. PMID:18670639

  15. Influenza A viruses suppress cyclooxygenase-2 expression by affecting its mRNA stability

    PubMed Central

    Dudek, Sabine Eva; Nitzsche, Katja; Ludwig, Stephan; Ehrhardt, Christina

    2016-01-01

    Infection with influenza A viruses (IAV) provokes activation of cellular defence mechanisms contributing to the innate immune and inflammatory response. In this process the cyclooxygenase-2 (COX-2) plays an important role in the induction of prostaglandin-dependent inflammation. While it has been reported that COX-2 is induced upon IAV infection, in the present study we observed a down-regulation at later stages of infection suggesting a tight regulation of COX-2 by IAV. Our data indicate the pattern-recognition receptor RIG-I as mediator of the initial IAV-induced COX-2 synthesis. Nonetheless, during on-going IAV replication substantial suppression of COX-2 mRNA and protein synthesis could be detected, accompanied by a decrease in mRNA half-life. Interestingly, COX-2 mRNA stability was not only imbalanced by IAV replication but also by stimulation of cells with viral RNA. Our results reveal tristetraprolin (TTP), which is known to bind COX-2 mRNA and promote its rapid degradation, as regulator of COX-2 expression in IAV infection. During IAV replication and viral RNA accumulation TTP mRNA synthesis was induced, resulting in reduced COX-2 levels. Accordingly, the down-regulation of TTP resulted in increased COX-2 protein expression after IAV infection. These findings indicate a novel IAV-regulated cellular mechanism, contributing to the repression of host defence and therefore facilitating viral replication. PMID:27265729

  16. Expression of the aryl hydrocarbon receptor pathway and cyclooxygenase-2 in dog tumors.

    PubMed

    Giantin, M; Vascellari, M; Lopparelli, R M; Ariani, P; Vercelli, A; Morello, E M; Cristofori, P; Granato, A; Buracco, P; Mutinelli, F; Dacasto, M

    2013-02-01

    In humans, the aryl hydrocarbon receptor (AHR) gene battery constitutes a set of contaminant-responsive genes, which have been recently shown to be involved in the regulation of several patho-physiological conditions, including tumorigenesis. As the domestic dog represents a valuable animal model in comparative oncology, mRNA levels of cytochromes P450 1A1, 1A2 and 1B1 (CYP1A1, 1A2 and 1B1), AHR, AHR nuclear translocator (ARNT), AHR repressor (AHRR, whose partial sequence was here obtained) and cyclooxygenase-2 (COX2) were measured in dog control tissues (liver, skin, mammary gland and bone), in 47 mast cell tumors (MCTs), 32 mammary tumors (MTs), 5 osteosarcoma (OSA) and related surgical margins. Target genes were constitutively expressed in the dog, confirming the available human data. Furthermore, their pattern of expression in tumor biopsies was comparable to that already described in a variety of human cancers; in particular, both AHR and COX2 genes were up-regulated and positively correlated, while CYP1A1 and CYP1A2 mRNAs were generally poorly expressed. This work demonstrated for the first time that target mRNAs are expressed in neoplastic tissues of dogs, thereby increasing the knowledge about dog cancer biology and confirming this species as an useful animal model for comparative studies on human oncology.

  17. Cyclooxygenase-2 Inhibitor Reduces Hepatic Stiffness in Pediatric Chronic Liver Disease Patients Following Kasai Portoenterostomy

    PubMed Central

    Chang, Hye Kyung; Chang, Eun Young; Ryu, Seonae

    2016-01-01

    Purpose The purpose of this study was to define the role of cyclooxygenase-2 inhibitors (COX-2i) in reducing hepatic fibrosis in pediatric patients with chronic liver disease. Materials and Methods From September 2009 to September 2010, patients over 2 years old who visited our outpatient clinic for follow-up to manage their chronic liver disease after Kasai portoenterostomy for biliary atresia, were included in this study. Volunteers were assigned to the study or control groups, according to their preference. A COX-2i was given to only the study group after obtaining consent. The degree of hepatic fibrosis (liver stiffness score, LSS) was prospectively measured using FibroScan, and liver function was examined using serum analysis before and after treatment. After 1 year, changes in LSSs and liver function were compared between the two groups. Results Twenty-five patients (18 females and 7 males) were enrolled in the study group. The control group included 44 patients (26 females and 18 males). After 1 year, the least square mean values for the LSSs were significantly decreased by 3.91±0.98 kPa (p=0.004) only in the study group. Serum total bilirubin did not decrease significantly in either group. Conclusion COX-2i treatment improved the LSS in patients with chronic liver disease after Kasai portoenterostomy for biliary atresia. PMID:27189282

  18. A cyclooxygenase-2 homologue encoded by rhesus cytomegalovirus is a determinant for endothelial cell tropism.

    PubMed

    Rue, Cary A; Jarvis, Michael A; Knoche, Amber J; Meyers, Heather L; DeFilippis, Victor R; Hansen, Scott G; Wagner, Markus; Früh, Klaus; Anders, David G; Wong, Scott W; Barry, Peter A; Nelson, Jay A

    2004-11-01

    Cyclooxygenase-2 (COX-2) is a cellular enzyme in the eicosanoid synthetic pathway that mediates the synthesis of prostaglandins from arachidonic acid. The eicosanoids function as critical regulators of a number of cellular processes, including the acute and chronic inflammatory response, hemostasis, and the innate immune response. Human cytomegalovirus (HCMV), which does not encode a viral COX-2 isoform, has been shown to induce cellular COX-2 expression. Importantly, although the precise role of COX-2 in CMV replication is unknown, COX-2 induction was shown to be critical for normal HCMV replication. In an earlier study, we identified an open reading frame (Rh10) within the rhesus cytomegalovirus (RhCMV) genome that encoded a putative protein (designated vCOX-2) with high homology to cellular COX-2. In the current study, we show that vCOX-2 is expressed with early-gene kinetics during RhCMV infection, resulting in production of a 70-kDa protein. Consistent with the expression of a viral COX-2 isoform, cellular COX-2 expression was not induced during RhCMV infection. Finally, analysis of growth of recombinant RhCMV with vCOX-2 deleted identified vCOX-2 as a critical determinant for replication in endothelial cells. PMID:15507640

  19. A Cyclooxygenase-2 Homologue Encoded by Rhesus Cytomegalovirus Is a Determinant for Endothelial Cell Tropism

    PubMed Central

    Rue, Cary A.; Jarvis, Michael A.; Knoche, Amber J.; Meyers, Heather L.; DeFilippis, Victor R.; Hansen, Scott G.; Wagner, Markus; Früh, Klaus; Anders, David G.; Wong, Scott W.; Barry, Peter A.; Nelson, Jay A.

    2004-01-01

    Cyclooxygenase-2 (COX-2) is a cellular enzyme in the eicosanoid synthetic pathway that mediates the synthesis of prostaglandins from arachidonic acid. The eicosanoids function as critical regulators of a number of cellular processes, including the acute and chronic inflammatory response, hemostasis, and the innate immune response. Human cytomegalovirus (HCMV), which does not encode a viral COX-2 isoform, has been shown to induce cellular COX-2 expression. Importantly, although the precise role of COX-2 in CMV replication is unknown, COX-2 induction was shown to be critical for normal HCMV replication. In an earlier study, we identified an open reading frame (Rh10) within the rhesus cytomegalovirus (RhCMV) genome that encoded a putative protein (designated vCOX-2) with high homology to cellular COX-2. In the current study, we show that vCOX-2 is expressed with early-gene kinetics during RhCMV infection, resulting in production of a 70-kDa protein. Consistent with the expression of a viral COX-2 isoform, cellular COX-2 expression was not induced during RhCMV infection. Finally, analysis of growth of recombinant RhCMV with vCOX-2 deleted identified vCOX-2 as a critical determinant for replication in endothelial cells. PMID:15507640

  20. Follicle-stimulating hormone enhances alveolar bone resorption via upregulation of cyclooxygenase-2

    PubMed Central

    Zhu, Chunxia; Ji, Yaoting; Liu, Shengbo; Bian, Zhuan

    2016-01-01

    This study aimed to investigate whether follicle-stimulating hormone (FSH)-induced alveolar bone resorption was mediated by a cyclooxygenase 2 (COX-2) enzyme related mechanism. Experimental periodontitis was induced in bilateral ovariectomized (OVX) rats, some of which were injected with triptorelin, an FSH inhibitor. After mandibles were collected, we performed micro-computed tomography to evaluate alveolar bone loss and immunohistochemical staining to assess COX-2 expression. As well, human periodontal ligament cells (PDLCs) were treated with FSH (30 ng/ml), and the COX-2 mRNA and protein expression levels were measured by quantitative real-time polymerase chain reaction (qPCR) and Western blotting, respectively; prostaglandin E2 (PGE2) levels were measured by enzyme-linked immunosorbent assay (ELISA). The results indicated that FSH significantly increased alveolar bone resorption and the expression of COX-2 in the bilateral OVX + Ligatured rats compared with the other treatment groups. FSH also increased the mRNA and protein expression of COX-2 and PGE2 (P < 0.01) in human PDLCs. Further, the analysis of signaling pathways revealed the activation of COX-2-mediated pathways including Erk, p38, and Akt. These data suggest that FSH aggravates alveolar bone loss via a COX-2-upregulation mechanism and that the Erk, p38, and Akt pathways are involved in this pathological process. PMID:27725865

  1. Premedication with cyclooxygenase-2 inhibitor meloxicam reduced postoperative pain in patients after oral surgery.

    PubMed

    Aoki, T; Yamaguchi, H; Naito, H; Shiiki, K; Izawa, K; Ota, Y; Sakamoto, H; Kaneko, A

    2006-07-01

    The efficacy of the selective cyclooxygenase-2 (COX-2) inhibitor meloxicam for treatment of postoperative oral surgical pain was assessed in a randomized controlled trial. Patients undergoing unilateral mandibular 3rd molar extraction surgery were allocated to 3 groups, A, B and C. After oral premedication of meloxicam 10 mg in group A, ampiroxicam 27 mg in group B and placebo in group C, surgery was completed within 30 min under local anaesthesia using 2% lidocaine. For postoperative pain relief the patients were allowed to take oral loxoprofen (60 mg per tablet). Postoperative pain was evaluated at the clinic on the 1st, 7th and 14th postoperative day (POD) using a visual analogue scale (VAS), as was the number of loxoprofen tablets consumed, and the results were compared among the 3 groups with statistical significance of P<0.05. VAS scores on 1 POD were significantly lower in group A than in group C. Loxoprofen consumption on the day of surgery and 1 POD was significantly lower in group A than in group C (P<0.01). Total analgesic consumption was significantly lower in groups A and B than in group C (P<0.02). The COX-2 inhibitor, meloxicam 10 mg used for premedication reduced postoperative pain compared with control in oral surgery. PMID:16540287

  2. Selective Visualization of Cyclooxygenase-2 in Inflammation and Cancer by Targeted Fluorescent Imaging Agents†

    PubMed Central

    Uddin, Md. Jashim; Crews, Brenda C.; Blobaum, Anna L.; Kingsley, Philip J.; Gorden, D. Lee; McIntyre, J. Oliver; Matrisian, Lynn M.; Subbaramaiah, Kotha; Dannenberg, Andrew J.; Piston, David W.; Marnett, Lawrence J.

    2010-01-01

    Effective diagnosis of inflammation and cancer by molecular imaging is challenging because of interference from non-selective accumulation of the contrast agents in normal tissues. Here we report a series of novel fluorescence imaging agents that efficiently target cyclooxygenase-2 (COX-2), which is normally absent from cells, but is found at high levels in inflammatory lesions, and in many premalignant and malignant tumors. After either intraperitoneal or intravenous injection, these reagents become highly enriched in inflamed or tumor tissue compared to normal tissue and this accumulation provides sufficient signal for in vivo fluorescence imaging. Further, we show that only the intact parent compound is found in the region of interest. COX-2-specific delivery was unambiguously confirmed using animals bearing targeted deletions of COX-2 and by blocking the COX-2 active site with high affinity inhibitors in both in vitro and in vivo models. Because of their high specificity, contrast, and detectability, these COX-2 beacons are ideal candidates for detection of inflammatory lesions or early-stage COX-2-expressing human cancers, such as those in the esophagus, oropharynx, and colon. PMID:20430759

  3. Assessment of the effects of the cyclooxygenase-2 inhibitor rofecoxib on visuospatial learning and hippocampal cell death following kainate-induced seizures in the rat.

    PubMed

    Kunz, Tina; Marklund, Niklas; Hillered, Lars; Oliw, Ernst H

    2005-12-01

    Kainate-induced seizures result in hippocampal neurodegeneration and spatial learning deficits in rodents. Previous studies show that rofecoxib, a selective cyclooxygenase-2 inhibitor, protects against kainate-induced hippocampal cell death 3 days after seizures. Our aim was to determine whether rofecoxib attenuates visuospatial learning deficits and late neuronal death after kainate-induced seizures. Seizures were induced in Sprague-Dawley rats with kainic acid (10 mg/kg, i.p.). Eight hours later, animals received rofecoxib (10 mg/kg; n = 15) or vehicle (dimethylsulfoxide, n = 11). Animals were then treated daily for additional 2 or 9 days. Visuospatial learning was assessed in the Morris water maze (MWM) on days 5-9 after seizures. Seizure animals learned the MWM task significantly slower than non-seizure controls, but seizure animals showed higher swim speed (P < 0.05). Seizure animals receiving rofecoxib for 2 days showed no significant improvement in acquisition of the task compared to the vehicle group, even though mean latencies in the rofecoxib group were shorter from the third trial day onwards. This tendency was lost when rofecoxib was given for 9 days. TdT-mediated dUTP nick end labelling showed cell death in limbic structures 9 days after seizures. The time course of kainate-induced hippocampal cell death might be delayed by rofecoxib treatment, as the attenuation of cell death observed 3 days after seizures was no longer present after 9 days. We conclude that even though increasing evidence points to an injurious role of cyclooxygenase-2 products in acute brain injury processes, rofecoxib treatment failed to attenuate seizure-induced visuospatial learning deficits and the late phase of hippocampal neurodegeneration. PMID:16263251

  4. miR-144 and targets, c-fos and cyclooxygenase-2 (COX2), modulate synthesis of PGE2 in the amnion during pregnancy and labor

    PubMed Central

    Li, Huanan; Zhou, Jiawei; Wei, Xiajie; Chen, Ran; Geng, Junnan; Zheng, Rong; Chai, Jin; Li, Fenge; Jiang, Siwen

    2016-01-01

    Labor is initiated as a result of hormonal changes that are induced by the activation of the inflammatory response and a series of biochemical events. The amnion, which is the primary source of prostaglandin E2 (PGE2), plays an important role in the process of labor. In the present study, we uncovered a pathway in which c-fos, cyclooxygenase-2 (COX2) and miR-144 function as hormonal modulators in the amnions of pregnant mice and humans. miR-144 down-regulated the synthesis of PGE2 during pregnancy by directly and indirectly inhibiting COX2 expression and by directly inhibiting the expression of c-fos, a transcriptional activator of COX2 and miR-144. Estrogen (E2) activated c-fos, thus promoting the expression of miR-144 and COX2 during labor. However, the increase in COX2 resulted in the partial inhibition of COX2 expression by miR-144, thereby slightly reducing the secretion of PGE2. These observations suggest that miR-144 inhibits PGE2 secretion by section to prevent the initiation of premature labor. Up-regulated expression of miR-144, c-fos and COX2 was also observed both in preterm mice and in mice undergoing normal labor. In summary, miR-144, c-fos and COX2 play important roles in regulating PGE2 secretion in the amnion during pregnancy and labor. PMID:27297132

  5. Targeting cyclooxygenase-2 with sodium butyrate and NSAIDs on colorectal adenoma/carcinoma cells

    PubMed Central

    Zhang, Zhi-Hong; Ouyang, Qin; Gan, Hua-Tian

    2004-01-01

    AIM: The protective effects of sodium butyrate and NSAIDs (especially the highly selective COX-2 inhibitors) have attracted considerable interest recently. In this study, primary adenoma cells and HT-29 were used to investigate whether the above drugs would be effective for reducing proliferation and inducing apoptosis. Additionally, it was investigated whether NSAIDs would strengthen the effects of sodium butyrate and its possible mechanisms. METHODS: In vitro primary cell culture of colorectal adenomas and HT-29 were used for this investigation. PGE2 isolated from HT-29 cell culture supernatants was investigated by ELISA. MTT was employed to detect the anti-proliferative effects on both adenoma and HT-29 culture cells. FCM was used for apoptosis rate and cell cycle analysis. The morphology of apoptotic cells was investigated by means of electromicroscopy. RESULTS: Sodium butyrate could stimulate the secretion of PGE2, while NSAIDs inhibited it to below 30 pg/106 cells. Both butyrate and NSAIDs could inhibit cell proliferation and induce apoptosis. The effects were time- and dose-dependent (P < 0.05). Aspirin and NS-398 could enhance the effects of sodium butyrate. The effects were stronger while sodium butyrate was used in combination with NS-398 than it was used in combination with Aspirin. CONCLUSION: Butyrate and NSAIDs could inhibit cell proliferation and induce apoptosis respectively. NSAIDs could enhance the effects of sodium butyrate by down-regulating COX-2 expression. Selective COX-2 inhibitor is better than traditional NSAIDs. PMID:15378772

  6. Ketamine protects acetylcholinesterase against inhibition by propoxur and phoxim.

    PubMed

    Koutsoviti-Papadopoulou, M; Kounenis, G; Elezoglou, V

    1994-01-01

    In the present study the effect of ketamine on the contractions caused by propoxur and phoxim on the isolated guinea pig ileum was investigated. Ketamine was found able to inhibit in a concentration-dependent manner the contractile responses of the ileum to propoxur and phoxim, while it did not significantly modify the contractions induced by acetylcholine. Propoxur and phoxim augmented the contractile responses induced by acetylcholine in the presence of acetylcholinesterase. This augmentation was prevented by ketamine, in a concentration-dependent manner. These findings suggest that ketamine inhibits the contractile effect of propoxur and phoxim on the guinea pig ileum and this inhibition seems to be associated with the protection of acetylcholinesterase against the action of these two compounds.

  7. Role of cyclooxygenase-2 in deoxynivalenol-induced immunoglobulin a nephropathy.

    PubMed

    Jia, Qunshan; Pestka, James J

    2005-05-01

    Ingestion of the trichothecene mycotoxin deoxynivalenol (DON) induces serum IgA elevation and kidney mesangial IgA deposition in a manner that mimics the early stages of IgA nephropathy (IgAN), the most common human glomerulonephritis. Previous studies indicate that elevated interleukin-6 (IL-6) expression is crucial for this model and that DON induction of cyclooxygenase-2 (COX-2) might drive IL-6 upregulation. We hypothesized that COX-2 and its metabolites are essential for DON-induced IgAN and thus might be a suitable target for prophylaxis against aberrant IgA upregulation. DON feeding studies using COX-2 knockout mice or the COX-2 specific inhibitor, rofecoxib (Vioxx), were employed to test the hypothesis. Study 1 results demonstrated that DON consumption induced serum IgA and IgA-immune complex (IC) accumulation, IgA kidney deposition and splenic IgA secretion in wild-type mice. COX-2 deficiency did not affect upregulation of these parameters but rather, promoted DON-induced serum IgA elevation. Study 2 demonstrated that rofecoxib could not block DON-induced serum IgA, serum IgA-IC and mesangial IgA accumulation but instead increased enhanced serum IgA upregulation. These corroborating results suggest that COX-2 is not a requisite for DON-induced IgAN and furthermore, that COX-2 inhibitors such as rofecoxib would be contraindicated for the prevention of early stages of IgAN. PMID:15778012

  8. Aged garlic extract attenuates cerebral damage and cyclooxygenase-2 induction after ischemia and reperfusion in rats.

    PubMed

    Colín-González, Ana Laura; Ortiz-Plata, Alma; Villeda-Hernández, Juana; Barrera, Diana; Molina-Jijón, Eduardo; Pedraza-Chaverrí, José; Maldonado, Perla D

    2011-11-01

    Different garlic products reduce the cerebral ischemic damage due to their antioxidant properties. In this work, we investigated the effect of aged garlic extract (AGE) on cyclooxygenase-2 (COX-2) protein levels and activity, and its role as a possible mechanism of neuroprotection in a cerebral ischemia model. Animals were subjected to 1 h of ischemia plus 24 h of reperfusion. AGE (1.2 ml/kg weight, i.p.) was administered at onset of reperfusion. To evaluate the damage induced by cerebral ischemia, the neurological deficit, the infarct area, and the histological alterations were measured. As an oxidative stress marker to deoxyribonucleic acid, 8-hydroxy-2-deoxyguanosine (8-OHdG) levels were determined. Finally, as inflammatory markers, TNFα levels and COX-2 protein levels and activity were measured. AGE treatment diminished the neurological alterations (61.6%), the infarct area (54.8%) and the histological damage (37.7%) induced by cerebral ischemia. AGE administration attenuated the increase in 8-OHdG levels (77.8%), in TNFα levels (76.6%), and in COX-2 protein levels (73.6%) and activity (30.7%) induced after 1 h of ischemia plus 24 h of reperfusion. These data suggest that the neuroprotective effect of AGE is associated not only to its antioxidant properties, but also with its capacity to diminish the increase in TNFα levels and COX-2 protein expression and activity. AGE may have the potential to attenuate the cerebral ischemia-induced inflammation.

  9. Interaction between inducible nitric oxide synthase and cyclooxygenase-2 after cerebral ischemia.

    PubMed

    Nogawa, S; Forster, C; Zhang, F; Nagayama, M; Ross, M E; Iadecola, C

    1998-09-01

    Focal cerebral ischemia is associated with expression of both inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), enzymes whose reaction products contribute to the evolution of ischemic brain injury. We tested the hypothesis that, after cerebral ischemia, nitric oxide (NO) produced by iNOS enhances COX-2 activity, thereby increasing the toxic potential of this enzyme. Cerebral ischemia was produced by middle cerebral artery occlusion in rats or mice. Twenty-four hours after ischemia in rats, iNOS-immunoreactive neutrophils were observed in close proximity (<20 micrometer) to COX-2-positive cells at the periphery of the infarct. In the olfactory bulb, only COX-2 positive cells were observed. Cerebral ischemia increased the concentration of the COX-2 reaction product prostaglandin E2 (PGE2) in the ischemic area and in the ipsilateral olfactory bulb. The iNOS inhibitor aminoguanidine reduced PGE2 concentration in the infarct, where both iNOS and COX-2 were expressed, but not in the olfactory bulb, where only COX-2 was expressed. Postischemic PGE2 accumulation was reduced significantly in iNOS null mice compared with wild-type controls (C57BL/6 or SV129). The data provide evidence that NO produced by iNOS influences COX-2 activity after focal cerebral ischemia. Pro-inflammatory prostanoids and reactive oxygen species produced by COX-2 may be a previously unrecognized factor by which NO contributes to ischemic brain injury. The pathogenic effect of the interaction between NO, or a derived specie, and COX-2 is likely to play a role also in other brain diseases associated with inflammation.

  10. Lower cyclooxygenase-2 expression is associated with recurrence of solitary non-muscle invasive bladder carcinoma

    PubMed Central

    2012-01-01

    Background A new modality is necessary to prevent recurrence of superficial bladder cancer after complete transurethral resection because of the high recurrence rate even with current prophylaxis protocols. Methods In order to analyze the predictive value of cyclooxygenase-2 (COX-2) expression and tumor infiltrating lymphocytes (TILs) in recurrence of this disease tumor specimens from 127 patients with solitary papillary non-muscle invasive bladder cancer (NMIBC), 78 with recurrent disease and 49 without recurrence during follow up of minimum 5 years, were retrieved for tissue microarrays construction and immunohistochemical analysis. COX-2 expression was scored according to Allred’s scoring protocol, while presence of TILs was categorized as absent (no) or present (yes) on whole tissue sections. Results COX-2 immunoreactivity was presented in 70 (71%), weak in 16% and strong in 55% of cases, while 29 (29%) tumors were negative. TILs were present in 64 (58%) NMIBC, while 44 cases (41%) did not reveal mononuclear infiltration in tumoral stroma. Statistical analysis demonstrated a higher proportion of patients with recurrence in the group with the COX-2 score 0, and lower in the group with score 2 (p=0.0001, p=0.0101, respectively). In addition, a higher proportion of recurrent patients in the group with no TILs, and lower proportion in the group with TILs were found (p=0.009, p=0.009, respectively). Univariate and multivariate analysis revealed overexpression of COX-2 and presence of TILs as negative predictors. Conclusion Patients with lower COX-2 expression and absence of TILs in NMIBC need to be followed up more vigorously and probably selected for adjuvant therapy. Virtual slide The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1411318819790406 PMID:23126361

  11. Pre-existent asymmetry in the human cyclooxygenase-2 sequence homodimer.

    PubMed

    Dong, Liang; Sharma, Narayan P; Jurban, Brice J; Smith, William L

    2013-10-01

    Prostaglandin endoperoxide H synthase-2 (PGHS-2), also known as cyclooxygenase-2 (COX-2), is a sequence homodimer. However, the enzyme exhibits half-site heme and inhibitor binding and functions as a conformational heterodimer having a catalytic subunit (Ecat) with heme bound and an allosteric subunit (Eallo) lacking heme. Some recombinant heterodimers composed of a COX-deficient mutant subunit and a native subunit (i.e. Mutant/Native PGHS-2) have COX activities similar to native PGHS-2. This suggests that the presence of heme plus substrate leads to the subunits becoming lodged in a semi-stable Eallo-mutant/Ecat-Native∼heme form during catalysis. We examined this concept using human PGHS-2 dimers composed of combinations of Y385F, R120Q, R120A, and S530A mutant or native subunits. With some heterodimers (e.g. Y385F/Native PGHS-2), heme binds with significantly higher affinity to the native subunit. This correlates with near native COX activity for the heterodimer. With other heterodimers (e.g. S530A/Native PGHS-2), heme binds with similar affinities to both subunits, and the COX activity approximates that expected for an enzyme in which each monomer contributes equally to the net COX activity. With or without heme, aspirin acetylates one-half of the subunits of the native PGHS-2 dimer, the Ecat subunits. Subunits having an S530A mutation are refractory to acetylation. Curiously, aspirin acetylates only one-quarter of the monomers of S530A/Native PGHS-2 with or without heme. This implies that there are comparable amounts of two noninterchangeable species of apoenzymes, Eallo-S530A/Ecat-Native and Eallo-Native/Ecat-S530A. These results suggest that native PGHS-2 assumes a reasonably stable, asymmetric Eallo/Ecat form during its folding and processing. PMID:23955344

  12. Epigenetic regulation of cyclooxygenase-2 by methylation of c8orf4 in pulmonary fibrosis.

    PubMed

    Evans, Iona C; Barnes, Josephine L; Garner, Ian M; Pearce, David R; Maher, Toby M; Shiwen, Xu; Renzoni, Elisabetta A; Wells, Athol U; Denton, Christopher P; Laurent, Geoffrey J; Abraham, David J; McAnulty, Robin J

    2016-04-01

    Fibroblasts derived from the lungs of patients with idiopathic pulmonary fibrosis (IPF) and systemic sclerosis (SSc) produce low levels of prostaglandin (PG) E2, due to a limited capacity to up-regulate cyclooxygenase-2 (COX-2). This deficiency contributes functionally to the fibroproliferative state, however the mechanisms responsible are incompletely understood. In the present study, we examined whether the reduced level of COX-2 mRNA expression observed in fibrotic lung fibroblasts is regulated epigenetically. The DNA methylation inhibitor, 5-aza-2'-deoxycytidine (5AZA) restored COX-2 mRNA expression by fibrotic lung fibroblasts dose dependently. Functionally, this resulted in normalization of fibroblast phenotype in terms of PGE2 production, collagen mRNA expression and sensitivity to apoptosis. COX-2 methylation assessed by bisulfite sequencing and methylation microarrays was not different in fibrotic fibroblasts compared with controls. However, further analysis of the methylation array data identified a transcriptional regulator, chromosome 8 open reading frame 4 (thyroid cancer protein 1, TC-1) (c8orf4), which is hypermethylated and down-regulated in fibrotic fibroblasts compared with controls. siRNA knockdown of c8orf4 in control fibroblasts down-regulated COX-2 and PGE2 production generating a phenotype similar to that observed in fibrotic lung fibroblasts. Chromatin immunoprecipitation demonstrated that c8orf4 regulates COX-2 expression in lung fibroblasts through binding of the proximal promoter. We conclude that the decreased capacity of fibrotic lung fibroblasts to up-regulate COX-2 expression and COX-2-derived PGE2 synthesis is due to an indirect epigenetic mechanism involving hypermethylation of the transcriptional regulator, c8orf4.

  13. Aged garlic extract attenuates cerebral damage and cyclooxygenase-2 induction after ischemia and reperfusion in rats.

    PubMed

    Colín-González, Ana Laura; Ortiz-Plata, Alma; Villeda-Hernández, Juana; Barrera, Diana; Molina-Jijón, Eduardo; Pedraza-Chaverrí, José; Maldonado, Perla D

    2011-11-01

    Different garlic products reduce the cerebral ischemic damage due to their antioxidant properties. In this work, we investigated the effect of aged garlic extract (AGE) on cyclooxygenase-2 (COX-2) protein levels and activity, and its role as a possible mechanism of neuroprotection in a cerebral ischemia model. Animals were subjected to 1 h of ischemia plus 24 h of reperfusion. AGE (1.2 ml/kg weight, i.p.) was administered at onset of reperfusion. To evaluate the damage induced by cerebral ischemia, the neurological deficit, the infarct area, and the histological alterations were measured. As an oxidative stress marker to deoxyribonucleic acid, 8-hydroxy-2-deoxyguanosine (8-OHdG) levels were determined. Finally, as inflammatory markers, TNFα levels and COX-2 protein levels and activity were measured. AGE treatment diminished the neurological alterations (61.6%), the infarct area (54.8%) and the histological damage (37.7%) induced by cerebral ischemia. AGE administration attenuated the increase in 8-OHdG levels (77.8%), in TNFα levels (76.6%), and in COX-2 protein levels (73.6%) and activity (30.7%) induced after 1 h of ischemia plus 24 h of reperfusion. These data suggest that the neuroprotective effect of AGE is associated not only to its antioxidant properties, but also with its capacity to diminish the increase in TNFα levels and COX-2 protein expression and activity. AGE may have the potential to attenuate the cerebral ischemia-induced inflammation. PMID:21850441

  14. Cyclooxygenase-2 gene disruption promotes proliferation of murine calvarial osteoblasts in vitro.

    PubMed

    Xu, Zheng; Choudhary, Shilpa; Okada, Yosuke; Voznesensky, Olga; Alander, Cynthia; Raisz, Lawrence; Pilbeam, Carol

    2007-07-01

    Cyclooxygenase-2 (COX-2) is highly expressed in osteoblasts, and COX-2 produced prostaglandins (PGs) can increase osteoblastic differentiation in vitro. The goal of this study was to examine effects of COX-2 expression on calvarial osteoblastic proliferation and apoptosis. Primary osteoblasts (POBs) were cultured from calvariae of COX-2 wild-type (WT) and knockout (KO) mice. POB proliferation was evaluated by (3)H-thymidine incorporation and analysis of cell replication and cell cycle distribution by flow cytometry. POB apoptosis was evaluated by annexin and PI staining on flow cytometry. As expected, PGE(2) production and alkaline phosphatase (ALP) activity were increased in WT cultures compared to KO cultures. In contrast, cell numbers were decreased in WT compared to KO cells by day 4 of culture. Proliferation, measured on days 3-7 of culture, was 2-fold greater in KO than in WT POBs and associated with decreased Go/G1 and increased S cell cycle distribution. There was no significant effect of COX-2 genotype on apoptosis under basal culture conditions on day 5 of culture. Cell growth was decreased in KO POBs by the addition of PGE(2) or a protein kinase A agonist and increased in WT POBs by the addition of NS398, a selective COX-2 inhibitor. In contrast, differentiation and cell growth in marrow stromal cell (MSC) cultures, evaluated by ALP and crystal violet staining respectively, were increased in MSCs from WT mice compared to MSCs from KO mice, and exogenous PGE(2) increased cell growth in KO MSC cultures. We conclude that PGs secondary to COX-2 expression decrease osteoblastic proliferation in cultured calvarial cells but increase growth of osteoblastic precursors in MSC cultures.

  15. Neuronal NOS and cyclooxygenase-2 contribute to DNA damage in a mouse model of Parkinson disease.

    PubMed

    Hoang, Tuan; Choi, Dong-Kug; Nagai, Makiko; Wu, Du-Chu; Nagata, Tetsuya; Prou, Delphine; Wilson, Glenn L; Vila, Miquel; Jackson-Lewis, Vernice; Dawson, Valina L; Dawson, Ted M; Chesselet, Marie-Françoise; Przedborski, Serge

    2009-10-01

    DNA damage is a proposed pathogenic factor in neurodegenerative disorders such as Parkinson disease. To probe the underpinning mechanism of such neuronal perturbation, we sought to produce an experimental model of DNA damage. We thus first assessed DNA damage by in situ nick translation and emulsion autoradiography in the mouse brain after administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 4 x 20 mg/kg, ip, every 2 h), a neurotoxin known to produce a model of Parkinson disease. Here we show that DNA strand breaks occur in vivo in this mouse model of Parkinson disease with kinetics and a topography that parallel the degeneration of substantia nigra neurons, as assessed by FluoroJade labeling. Previously, nitric oxide synthase and cyclooxygenase-2 (Cox-2) were found to modulate MPTP-induced dopaminergic neuronal death. We thus assessed the contribution of these enzymes to DNA damage in mice lacking neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), or Cox-2. We found that the lack of Cox-2 and nNOS activities but not of iNOS activity attenuated MPTP-related DNA damage. We also found that not only nuclear, but also mitochondrial, DNA is a target for the MPTP insult. These results suggest that the loss of genomic integrity can be triggered by the concerted actions of nNOS and Cox-2 and provide further support to the view that DNA damage may contribute to the neurodegenerative process in Parkinson disease. PMID:19616617

  16. Calpain inhibition mediates autophagy-dependent protection against polyglutamine toxicity

    PubMed Central

    Menzies, F M; Garcia-Arencibia, M; Imarisio, S; O'Sullivan, N C; Ricketts, T; Kent, B A; Rao, M V; Lam, W; Green-Thompson, Z W; Nixon, R A; Saksida, L M; Bussey, T J; O'Kane, C J; Rubinsztein, D C

    2015-01-01

    Over recent years, accumulated evidence suggests that autophagy induction is protective in animal models of a number of neurodegenerative diseases. Intense research in the field has elucidated different pathways through which autophagy can be upregulated and it is important to establish how modulation of these pathways impacts upon disease progression in vivo and therefore which, if any, may have further therapeutic relevance. In addition, it is important to understand how alterations in these target pathways may affect normal physiology when constitutively modulated over a long time period, as would be required for treatment of neurodegenerative diseases. Here we evaluate the potential protective effect of downregulation of calpains. We demonstrate, in Drosophila, that calpain knockdown protects against the aggregation and toxicity of proteins, like mutant huntingtin, in an autophagy-dependent fashion. Furthermore, we demonstrate that, overexpression of the calpain inhibitor, calpastatin, increases autophagosome levels and is protective in a mouse model of Huntington's disease, improving motor signs and delaying the onset of tremors. Importantly, long-term inhibition of calpains did not result in any overt deleterious phenotypes in mice. Thus, calpain inhibition, or activation of autophagy pathways downstream of calpains, may be suitable therapeutic targets for diseases like Huntington's disease. PMID:25257175

  17. Tiagabine Protects Dopaminergic Neurons against Neurotoxins by Inhibiting Microglial Activation

    PubMed Central

    Liu, Jie; Huang, Dongping; Xu, Jing; Tong, Jiabin; Wang, Zishan; Huang, Li; Yang, Yufang; Bai, Xiaochen; Wang, Pan; Suo, Haiyun; Ma, Yuanyuan; Yu, Mei; Fei, Jian; Huang, Fang

    2015-01-01

    Microglial activation and inflammation are associated with progressive neuronal apoptosis in neurodegenerative disorders such as Parkinson’s disease (PD). γ-Aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system, has recently been shown to play an inhibitory role in the immune system. Tiagabine, a piperidine derivative, enhances GABAergic transmission by inhibiting GABA transporter 1 (GAT 1). In the present study, we found that tiagabine pretreatment attenuated microglial activation, provided partial protection to the nigrostriatal axis and improved motor deficits in a methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. The protective function of tiagabine was abolished in GAT 1 knockout mice that were challenged with MPTP. In an alternative PD model, induced by intranigral infusion of lipopolysaccharide (LPS), microglial suppression and subsequent neuroprotective effects of tiagabine were demonstrated. Furthermore, the LPS-induced inflammatory activation of BV-2 microglial cells and the toxicity of conditioned medium toward SH-SY5Y cells were inhibited by pretreatment with GABAergic drugs. The attenuation of the nuclear translocation of nuclear factor κB (NF-κB) and the inhibition of the generation of inflammatory mediators were the underlying mechanisms. Our results suggest that tiagabine acts as a brake for nigrostriatal microglial activation and that it might be a novel therapeutic approach for PD. PMID:26499517

  18. Tiagabine Protects Dopaminergic Neurons against Neurotoxins by Inhibiting Microglial Activation.

    PubMed

    Liu, Jie; Huang, Dongping; Xu, Jing; Tong, Jiabin; Wang, Zishan; Huang, Li; Yang, Yufang; Bai, Xiaochen; Wang, Pan; Suo, Haiyun; Ma, Yuanyuan; Yu, Mei; Fei, Jian; Huang, Fang

    2015-10-26

    Microglial activation and inflammation are associated with progressive neuronal apoptosis in neurodegenerative disorders such as Parkinson's disease (PD). γ-Aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system, has recently been shown to play an inhibitory role in the immune system. Tiagabine, a piperidine derivative, enhances GABAergic transmission by inhibiting GABA transporter 1 (GAT 1). In the present study, we found that tiagabine pretreatment attenuated microglial activation, provided partial protection to the nigrostriatal axis and improved motor deficits in a methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. The protective function of tiagabine was abolished in GAT 1 knockout mice that were challenged with MPTP. In an alternative PD model, induced by intranigral infusion of lipopolysaccharide (LPS), microglial suppression and subsequent neuroprotective effects of tiagabine were demonstrated. Furthermore, the LPS-induced inflammatory activation of BV-2 microglial cells and the toxicity of conditioned medium toward SH-SY5Y cells were inhibited by pretreatment with GABAergic drugs. The attenuation of the nuclear translocation of nuclear factor κB (NF-κB) and the inhibition of the generation of inflammatory mediators were the underlying mechanisms. Our results suggest that tiagabine acts as a brake for nigrostriatal microglial activation and that it might be a novel therapeutic approach for PD.

  19. Mesenchymal stem cells alleviate airway inflammation and emphysema in COPD through down-regulation of cyclooxygenase-2 via p38 and ERK MAPK pathways

    PubMed Central

    Gu, Wen; Song, Lin; Li, Xiao-Ming; Wang, Di; Guo, Xue-Jun; Xu, Wei-Guo

    2015-01-01

    Bone marrow-derived mesenchymal stem cells (MSCs) have been identified as one possible strategy for the treatment of chronic obstructive pulmonary disease (COPD). Our previous studies have demonstrated that MSC administration has therapeutic potential in airway inflammation and emphysema via a paracrine mechanism. We proposed that MSCs reverse the inflammatory process and restore impaired lung function through their interaction with macrophages. In our study, the rats were exposed to cigarette smoke (CS), followed by the administration of MSCs into the lungs for 5 weeks. Here we show that MSC administration alleviated airway inflammation and emphysema through the down-regulation of cyclooxygenase-2 (COX-2) and COX-2-mediated prostaglandin E2 (PGE2) production, possibly through the effect on alveolar macrophages. In vitro co-culture experiments provided evidence that MSCs down-regulated COX-2/PGE2 in macrophages through inhibition of the activation-associated phosphorylation of p38 MAPK and ERK. Our data suggest that MSCs may relieve airway inflammation and emphysema in CS-exposed rat models, through the inhibition of COX-2/PGE2 in alveolar macrophages, mediated in part by the p38 MAPK and ERK pathways. This study provides a compelling mechanism for MSC treatment in COPD, in addition to its paracrine mechanism. PMID:25736434

  20. Prognostic significance of cyclooxygenase-2 expression in patients with hepatocellular carcinoma: a meta-analysis

    PubMed Central

    Chen, Guodong; Li, Xiaoyan; Yang, Jing; Li, Jie; Wang, Xia

    2016-01-01

    Introduction Cyclooxygenase-2 (COX-2) is believed to be an important enzyme in the carcinogenesis of hepatocellular carcinoma (HCC). However, it is still controversial whether COX-2 expression can be regarded as a prognostic factor for HCC patients. We performed a systematic review and meta-analysis of studies assessing the clinical and prognostic significance of COX-2 expression in HCC. Material and methods Identification and review of publications assessing clinical or prognostic significance of COX-2 expression in HCC until November 1, 2014. A meta-analysis was performed to clarify the association between COX-2 expression and clinical outcomes. Results A total of 11 publications met the criteria and included 943 cases. Analysis of these data showed that COX-2 expression was not significantly correlated with capsular formation (OR = 0.84, 95% confidence interval (CI): 0.46–1.55, p = 0.58), tumor TNM stage (OR = 0.73, 95% CI: 0.23–2.33, p = 0.59), vascular invasion (OR = 1.04, 95% CI: 0.25–4.35, p = 0.96), tumor size (OR = 0.78, 95% CI: 0.21–2.86, p = 0.71), or tumor differentiation degree (OR = 1.08, 95% CI: 0.42–2.79, p = 0.87). However, in the identified studies, COX-2 expression was strongly associated with high alpha-fetoprotein level (OR = 1.83, 95% CI: 1.01–3.33, p = 0.05), HBsAg status (OR = 1.85, 95% CI: 1.13–3.03, p = 0.01), decreased overall survival (relative risk (RR): 1.54, 95% CI: 1.18–2.02, p = 0.001) and decreased disease-free survival (RR = 1.49, 95% CI: 1.22–1.81, p < 0.001). Conclusions This meta-analysis shows that COX-2 expression in HCC is associated with decreased overall and disease-free survival and thus marks a worse prognosis. Nevertheless, more large sample and well-designed studies are warranted to confirm this finding. PMID:27695503

  1. Pharmacokinetics and safety of JTE-522, a novel selective cyclooxygenase-2 inhibitor, in healthy male volunteers

    PubMed Central

    Ikeda, Yasuhiko; Umemura, Kazuo; Kondo, Kazunao; Nakashima, Mitsuyoshi; Kobayashi, Takuo; Takahashi, Mitsuru

    2002-01-01

    Aims The pharmacokinetics and safety profile of JTE-522, 4-(4-cyclohexyl-2 methyloxazol-5-yl)-2-fluorobenzensulphonamide, a novel selective cyclooxygenase-2 inhibitor were investigated in healthy male volunteers. Methods Initially, as a pilot study, five groups of two subjects were given oral doses of 3–100 mg of JTE-522. After safety assessment, subjects were given 150 and 200 mg of JTE-522. The effect of food-intake on the pharmacokinetics of JTE-522 at a dose of 150 mg was examined. In the multiple-dose study, subjects were given 150 mg of JTE-522 once a day for 7 days. Concentrations of unchanged JTE-522 in plasma, blood and urine were determined by high performance liquid chromatography (h.p.l.c.). Concentrations of metabolites were estimated with h.p.l.c. chromatograms and calibration curves for quantification of unchanged JTE-522. Results In the course of this study, no serious abnormality attributable to the test drug was observed, suggesting that JTE-522 was well tolerated in healthy subjects. In a single-dose study, the concentrations of JTE-522 in blood were much higher than the corresponding concentrations in plasma. JTE-522 was readily distributed to blood cells and percentage distribution into blood cells was more than 99.0%. However, the values of Cmax in blood at doses of 100, 150, 200 mg JTE-522 were 15241, 20445 ± 3918 (16333–24556), 20965 ± 3260 (17544–24386) ng ml−1, respectively. These findings suggest that JTE-522 has a high affinity for blood cells and the distribution into blood cells is limited at the higher doses of over 100 mg. In a multiple dose study, pharmacokinetic parameters including t1/2 and AUC after the fourth administration were comparable with that of the seventh administration. Thus, these findings suggest the absence of accumulation on the multiple-dosing of JTE-522. Conclusions These results indicate that JTE-522 has an acceptable pharmacokinetic profile for clinical use without any serious adverse events as we

  2. Regulation of cyclooxygenase-2 expression by cAMP response element and mRNA stability in a human airway epithelial cell line exposed to zinc

    EPA Science Inventory

    Exposure to zinc-laden particulate matter in ambient and occupational settings has been associated with proinflammatory responses in the lung. Cyclooxygenase 2-derived eicosanoids are important modulators of airway inflammation. In this study, we characterized the transcriptional...

  3. Effects of nimesulide, acetylsalicylic acid, ibuprofen and nabumetone on cyclooxygenase-1- and cyclooxygenase-2-mediated prostanoid production in healthy volunteers ex vivo.

    PubMed

    Kerola, Markku; Vuolteenaho, Katriina; Kosonen, Outi; Kankaanranta, Hannu; Sarna, Seppo; Moilanen, Eeva

    2009-01-01

    : The beneficial actions of non-steroidal anti-inflammatory drugs (NSAIDs) have been associated with inhibition of cyclooxygenase-2 (COX-2), whereas some of their adverse effects are associated mainly with inhibition of COX-1. Selective COX-2 inhibitors reduce the risk of gastrointestinal adverse events, but increase the risk of thromboembolic events pointing to importance of optimal COX-1/COX-2 inhibition in drug safety. We compared the effects of acetylsalicylic acid, ibuprofen, nabumetone and nimesulide on COX-1 and COX-2 pathways in healthy volunteers in an ex vivo set-up using single oral doses commonly used to treat acute pain. In a randomized, double-blind four-phase cross-over study, 15 healthy volunteers were given orally a single dose of either acetylsalicylic acid 500 mg, ibuprofen 400 mg, nabumetone 1 g or nimesulide 100 mg. Blood samples were drawn before and 1, 3, 6, 24 and 48 hr after the drug for the assessment of COX-1 and COX-2 activity. COX-1 activity was measured as thromboxane(2) production during blood clotting and COX-2 activity as endotoxin-induced prostaglandin E(2) synthesis in blood leucocytes. The data show that after a single oral dose these four NSAIDs have different profiles of action on COX-1 and COX-2. As expected, acetylsalicylic acid appeared to be COX-1-selective and ibuprofen effectively inhibited both COX-1 and COX-2. Nabumetone showed only a slight inhibitory effect on COX-1 and COX-2. Nimesulide caused almost complete suppression of COX-2 activity and a partial reduction of COX-1 activity. This confirms the relative COX-2 selectivity of nimesulide.

  4. Radiation Therapy Overcomes Adverse Prognostic Role of Cyclooxygenase-2 Expression on Reed-Sternberg Cells in Early Hodgkin Lymphoma

    SciTech Connect

    Mestre, Francisco; Gutiérrez, Antonio; Rodriguez, Jose; Ramos, Rafael; Garcia, Juan Fernando; Martinez-Serra, Jordi; Casasus, Marta; Nicolau, Cristina; Bento, Leyre; Herraez, Ines; Lopez-Perezagua, Paloma; Daumal, Jaime; Besalduch, Joan

    2015-05-01

    Purpose: To analyze the role of radiation therapy (RT) on the adverse prognostic influence of cyclooxygenase-2 (COX-2) expression on Reed-Sternberg (RS) cells, in the setting of early Hodgkin lymphoma (HL) treated with ABVD (adriamycin, vinblastine, bleomycin, dacarbazine). Methods and Materials: In the present study we retrospectively investigated the prognostic value of COX-2 expression in a large (n=143), uniformly treated early HL population from the Spanish Network of HL using tissue microarrays. Univariate and multivariate analyses were done, including the most recognized clinical variables and the potential role of administration of adjuvant RT. Results: Median age was 31 years; the expression of COX-2 defined a subgroup with significantly worse prognosis. Considering COX-2{sup +} patients, those who received RT had significantly better 5-year progression-free survival (PFS) (80% vs 54% if no RT; P=.008). In contrast, COX-2{sup −} patients only had a modest, nonsignificant benefit from RT in terms of 5-year PFS (90% vs 79%; P=.13). When we compared the outcome of patients receiving RT considering the expression of COX-2 on RS cells, we found a nonsignificant 10% difference in terms of PFS between COX-2{sup +} and COX-2{sup −} patients (P=.09), whereas the difference between the 2 groups was important (25%) in patients not receiving RT (P=.04). Conclusions: Cyclooxygenase-2 RS cell expression is an adverse independent prognostic factor in early HL. Radiation therapy overcomes the worse prognosis associated with COX-2 expression on RS cells, acting in a chemotherapy-independent way. Cyclooxygenase-2 RS cell expression may be useful for determining patient candidates with early HL to receive consolidation with RT.

  5. Caveolin-1-mediated suppression of cyclooxygenase-2 via a beta-catenin-Tcf/Lef-dependent transcriptional mechanism reduced prostaglandin E2 production and survivin expression.

    PubMed

    Rodriguez, Diego A; Tapia, Julio C; Fernandez, Jaime G; Torres, Vicente A; Muñoz, Nicolas; Galleguillos, Daniela; Leyton, Lisette; Quest, Andrew F G

    2009-04-01

    Augmented expression of cyclooxygenase-2 (COX-2) and enhanced production of prostaglandin E(2) (PGE(2)) are associated with increased tumor cell survival and malignancy. Caveolin-1 is a scaffold protein that has been proposed to function as a tumor suppressor in human cancer cells, although mechanisms underlying this ability remain controversial. Intriguingly, the possibility that caveolin-1 regulates the expression of COX-2 has not been explored. Here we show that augmented caveolin-1 expression in cells with low basal levels of this protein, such as human colon cancer (HT29, DLD-1), breast cancer (ZR75), and embryonic kidney (HEK293T) cells reduced COX-2 mRNA and protein levels and beta-catenin-Tcf/Lef and COX-2 gene reporter activity, as well as the production of PGE(2) and cell proliferation. Moreover, COX-2 overexpression or PGE(2) supplementation increased levels of the inhibitor of apoptosis protein survivin by a transcriptional mechanism, as determined by PCR analysis, survivin gene reporter assays and Western blotting. Furthermore, addition of PGE(2) to the medium prevented effects attributed to caveolin-1-mediated inhibition of beta-catenin-Tcf/Lef-dependent transcription. Finally, PGE(2) reduced the coimmunoprecipitation of caveolin-1 with beta-catenin and their colocalization at the plasma membrane. Thus, by reducing COX-2 expression, caveolin-1 interrupts a feedback amplification loop involving PGE(2)-induced signaling events linked to beta-catenin/Tcf/Lef-dependent transcription of tumor survival genes including cox-2 itself and survivin. PMID:19244345

  6. Design, Synthesis, and Biological Evaluation of New 2-Phenyl-4H-chromen-4-one Derivatives as Selective Cyclooxygenase-2 Inhibitors

    PubMed Central

    Zarghi, Afshin; Kakhki, Samaneh

    2015-01-01

    In order to develop new selective COX-2 inhibitors, a new series of 2-phenyl-4H-chromen-4-one derivatives possessing a methylsulfonyl pharmacophore group at the para position of the C-4 phenyl ring were designed, synthesized, and evaluated for cyclooxygenase-2 inhibitory activity. In vitro COX-1/COX-2 isozyme inhibition structure-activity studies identified 3-(benzyloxy)-2-[4-(methylsulfonyl)phenyl]-4H-chromen-4-one (5d) as a potent COX-2 inhibitor (IC50 = 0.07 μM) with a high COX-2 selectivity index (SI = 287.1) comparable to the reference drug celecoxib (COX-2 IC50 = 0.06 μM; COX-2 SI = 405). A molecular modeling study where 3-(benzyloxy)-2-[4-(methylsulfonyl)phenyl]-4H-chromen-4-one (5d) was docked into the active site of COX-2 showed that the p-MeSO2 substituent on the C-4 phenyl ring was well-oriented in the vicinity of the COX-2 secondary pocket (Arg513, Val523, and His90) and the carbonyl group of the chromene ring could interact with Ser530. The structure-activity data acquired indicated that the nature and size of the substituent on the C-3 chromene scaffold are important for COX-2 inhibitory activity. Our results also indicated that the chromene moiety constitutes a suitable template to design new COX-2 inhibitors. PMID:26839798

  7. Design, Synthesis and Biological Evaluation of 5-Oxo-1,4,5,6,7,8 Hexahydroquinoline Derivatives as Selective Cyclooxygenase-2 Inhibitors

    PubMed Central

    Zarghi, Afshin; Sabakhi, Iman; Topuzyan, Vigen; Hajimahdi, Zahra; Daraie, Bahram

    2014-01-01

    A group of regioisomeric 5-oxo-1,4,5,6,7,8 hexahydroquinoline derivatives possessing a COX-2 SO2Me pharmacophore at the para position of the C-2 or C-4 phenyl ring, in conjunction with a C-4 or C-2 phenyl (4-H) or substituted-phenyl ring (4-F,4-Cl,4-Br,4-OMe,4-Me, 4-NO2), were designed for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. These target 5-oxo-1,4,5,6,7,8 hexahydroquinolines were synthesized via a Hansch condensation reaction. In vitro COX-1/COX-2 isozyme inhibition structure-activity studies identified 7,8-dihydro- 7,7-dimethyl-2-(4-methoxyphenyl)-4-(4-(methylsulfonyl)phenyl)quinolin-5(1H,4H,6H)- one (9c) as a potent COX-2 inhibitor (IC50 = 0.17 M) with a high COX-2 selectivity index (S.I. = 97.6) comparable to the reference drug celecoxib (COX-2 IC50 = 0.05 mM; COX-2 S.I= 405). A molecular modeling study where 9c was docked in active site of COX-2 showed that the p-SO2Me substituent on the C-2 phenyl ring is inserted into the secondary COX-2 binding site. The structure activity data acquired indicate that the position of the COX-2 SO2Me pharmacophore and type of substituent are important for COX-2 inhibitory activity. PMID:24711830

  8. USP22 acts as an oncogene by regulating the stability of cyclooxygenase-2 in non-small cell lung cancer

    SciTech Connect

    Xiao, Haibo; Tian, Yue; Yang, Yang; Hu, Fengqing; Xie, Xiao; Mei, Ju; Ding, Fangbao

    2015-05-08

    The histone ubiquitin hydrolase ubiquitin-specific protease 22 (USP22) is an epigenetic modifier and an oncogene that is upregulated in many types of cancer. In non-small cell lung cancer (NSCLC), aberrant expression of USP22 is a predictor of poor survival, as is high expression of cyclooxygenase-2 (COX-2). Despite its oncogenic role, few substrates of USP22 have been identified and its mechanism of action in cancer remains unclear. Here, we identified COX-2 as a direct substrate of USP22 and showed that its levels are modulated by USP22 mediated deubiquitination. Silencing of USP22 downregulated COX-2, decreased its half-life, and inhibited lung carcinoma cell proliferation by directly interacting with and modulating the stability and activity of COX-2 through the regulation of its ubiquitination status. The findings of the present study suggest a potential mechanism underlying the oncogenic role of USP22 mediated by the modulation of the stability and activity of COX-2. - Highlights: • USP22 interacts with COX-2. • USP22 deubiquitinates and stabilizes COX-2. • USP22 is required for COX-2-mediated upregulation of prostaglandin E2.

  9. Celecoxib enhanced the cytotoxic effect of cisplatin in chemo-resistant gastric cancer xenograft mouse models through a cyclooxygenase-2-dependent manner.

    PubMed

    Xu, Hong-Bin; Shen, Fu-Ming; Lv, Qian-Zhou

    2016-04-01

    Our previous study suggested that co-administration of celecoxib increased chemo-sensitivity of multidrug-resistant human gastric cancer SGC-7901/DDP cells to cisplatin (DDP) in vitro. The present study was designed to investigate whether celecoxib had the similar activities in vivo. SGC-7901/DDP and SGC-7901 xenograft mouse models were established. At the end of the experiment, cisplatin treatment alone significantly inhibited tumor growth in SGC-7901 xenograft, as compared with that in SGC-7901/DDP xenograft, suggesting that it maintained cisplatin sensitivity. When cisplatin and celecoxib were co-administrated, their antitumor activities were augmented in SGC-7901/DDP xenograft. The levels of Ki67 and PCNA after combination therapy were significantly decreased in SGC-7901/DDP xenograft, as compared with those of cisplatin treatment alone. Moreover, examining the apoptotic index by TUNEL assay showed similar results. Further studies demonstrated the inhibitory effect of celecoxib on cyclooxygenase-2 and P-glycoprotein expression was the possible reason to increase sensitivity of SGC-7901/DDP cells to cisplatin in vivo. However, the ratio of thromboxane B2 and prostaglandin F1α was elevated after celecoxib treatment in mice. This has been proposed to increase the risk of thrombogenesis. Further studies are required to evaluate the efficacy and safety of celecoxib for reducing chemo-resistance in gastric cancer. PMID:26879869

  10. Cyclooxygenase-2 expression in esophageal epithelium before and after photodynamic therapy for Barrett's esophagus with high-grade dysplasia or intramucosal carcinoma.

    PubMed

    Yachimski, Patrick; Mino-Kenudson, Mari; Sherwood, Margaret E; Puricelli, William P; Nishioka, Norman S; Lauwers, Gregory Y

    2011-12-01

    Cyclooxygenase-2 expression is upregulated in Barrett's esophagus and esophageal adenocarcinoma. Photodynamic therapy using porfimer sodium can result in ablation of dysplasia and intramucosal carcinoma, eradication of Barrett's esophagus, and restitution of squamous epithelium. The aim of this study was to determine the effect of photodynamic therapy on cyclooxygenase-2 expression in esophageal epithelium. Paired pre- and post-photodynamic therapy biopsy samples from the same anatomical levels of 20 individuals who had undergone photodynamic therapy for Barrett's esophagus with high-grade dysplasia and/or intramucosal carcinoma were immunostained using a cyclooxygenase-2 monoclonal antibody. Cyclooxygenase-2 expression was graded in squamous epithelium, Barrett's esophagus, and neoplasia (if present) as follows: grade 0 (no staining), grade 1 (staining in 1-10% of cells), grade 2 (staining in 11-90% of cells), and grade 3 (staining in >90% of cells). Pre-photodynamic therapy median cyclooxygenase-2 expression was grade 2 (range 1-3) in neoplastic foci and grade 1 (range 1-3) in nondysplastic Barrett's esophagus (P=0.0009 for pairwise comparison). With the exception of a few cells staining in the basal epithelial layers, median cyclooxygenase-2 expression was graded as 0 (similar to controls) in both pre-photodynamic therapy squamous epithelium and post-photodynamic therapy neosquamous epithelium. This was significantly lower when compared to either neoplastic foci (P<0.0001) or nondysplastic Barrett's esophagus (P<0.0001) pre-photodynamic therapy. Notably, in four patients with post-photodynamic therapy recurrent neoplasia, cyclooxygenase-2 expression returned to elevated levels. Cyclooxygenase-2 expression is elevated in Barrett's esophagus with high-grade dysplasia or intramucosal carcinoma prior to photodynamic therapy. Following successful photodynamic therapy, cyclooxygenase-2 expression in neosquamous epithelium returns to a low baseline level similar to

  11. Synthesis and crystal structure of N-[(dimethylamino)methylidene]-4-[1-(4-nitrophenyl)-1H-tetrazol-5-yl]-benzenesulfonamide: Molecular docking and bioassay studies as cyclooxygenase-2 inhibitor

    NASA Astrophysics Data System (ADS)

    Jawabrah Al-Hourani, Baker; El-Barghouthi, Musa I.; McDonald, Robert; Al-Awaida, Wajdy; Sharma, Sai Kiran; Wuest, Frank

    2016-09-01

    The synthesis of N-[(dimethylamino)methylidene]-4-[1-(4-nitrophenyl)-1H-tetrazol-5-yl]benzenesulfonamide (3) has been easily approached and the structure has been determined by X-ray crystallography. Tetrazole 3 crystallizes in the monoclinic space group C2/c, with the cell parameters determined as a = 35.5408 (18) Å, b = 7.6972 (4) Å, c = 13.0700 (7) Å3, β = 96.8598 (6)°, V = 3549.9 (3) Å3, and Z = 8. Its structure refines to R1 = 0.0341 (for 2986 observed reflections [I ≥ 2σ(I)]) and wR2 = 0.0990 (for all 3637 unique reflections). The aryl rings at the 1- and 5-positions show no conjugation to the tetrazole group, and the [(Dimethylamino)methylene]aminosulfonyl (Me2NCHNSO2) group is disordered, with the two disorder conformers being related by a pseudo mirror plane. In the crystal, intermolecular interactions between adjacent molecule of 3 are dominated by weak (2.4-2.7 Å) CeH…O and CeH…N hydrogen bonds. The molecular docking studies were carried out to understand the interaction of compound 3 within the active site of the cyclooxygenase-2 enzyme, followed by a comparison study with the celecoxib drug as a reference compound. The in vitro bioassay studies of tetrazole 3 toward cyclooxygenase-1 and cyclooxygenase-2 enzymes showed that compound 3 has no inhibition potency for either enzyme.

  12. Endoplasmic reticulum stress eIF2α-ATF4 pathway-mediated cyclooxygenase-2 induction regulates cadmium-induced autophagy in kidney.

    PubMed

    Luo, B; Lin, Y; Jiang, S; Huang, L; Yao, H; Zhuang, Q; Zhao, R; Liu, H; He, C; Lin, Z

    2016-01-01

    The heavy metal cadmium (Cd) is nephrotoxic. Recent studies show that autophagy plays an essential role in Cd-induced kidney injury. However, the mechanisms of Cd-induced kidney injury accompanied by autophagy are still obscure. In the present study, we first confirmed that Cd induced kidney damage and dysfunction, along with autophagy, both in vivo and in vitro. Then, we observed that cyclooxygenase-2 (COX-2) and the eIF2α-ATF4 pathway of endoplasmic reticulum (ER) stress were induced by Cd in both kidney tissues and cultured cells. Further studies showed that inhibition of COX-2 with celecoxib or RNA interference (RNAi) inhibited the Cd-induced autophagy in kidney cells. In addition, blocking ER stress with 4-phenylbutyrate or RNAi partially counteracted COX-2 overexpression and autophagy induced by Cd, which suggested that ER stress was required for Cd-induced kidney autophagy. Significantly, our results showed that Cd activated ATF4 and induced its translocation to the nucleus. Knockdown of ATF4 inhibited Cd-induced COX-2 overexpression. While COX-2 overexpression is involved in renal dysfunction, there is no prior report on the role of COX-2 in autophagy regulation. The results of the current study suggest a novel molecular mechanism that the ER stress eIF2α-ATF4 pathway-mediated COX-2 overexpression contributes to Cd-induced kidney autophagy and injury. The present study implies that COX-2 may be a potential target for therapy against Cd-induced nephrotoxicity. PMID:27253415

  13. Metformin Inhibits Glutaminase Activity and Protects against Hepatic Encephalopathy

    PubMed Central

    Ampuero, Javier; Ranchal, Isidora; Nuñez, David; Díaz-Herrero, María del Mar; Maraver, Marta; del Campo, José Antonio; Rojas, Ángela; Camacho, Inés; Figueruela, Blanca; Bautista, Juan D.; Romero-Gómez, Manuel

    2012-01-01

    inhibits glutaminase activity in vitro. Therefore, metformin use seems to be protective against hepatic encephalopathy in diabetic cirrhotic patients. PMID:23166628

  14. Regulation of p53, nuclear factor {kappa}B and cyclooxygenase-2 expression by bromelain through targeting mitogen-activated protein kinase pathway in mouse skin

    SciTech Connect

    Kalra, Neetu; Bhui, Kulpreet; Roy, Preeti; Srivastava, Smita; George, Jasmine; Prasad, Sahdeo; Shukla, Yogeshwer

    2008-01-01

    Bromelain is a pharmacologically active compound, present in stems and immature fruits of pineapples (Ananas cosmosus), which has been shown to have anti-edematous, anti-inflammatory, anti-thrombotic and anti-metastatic properties. In the present study, antitumorigenic activity of bromelain was recorded in 7,12-dimethylbenz(a)anthracene (DMBA)-initiated and 12-O-tetradecanoylphorbol-13-acetate (TPA)-promoted 2-stage mouse skin model. Results showed that bromelain application delayed the onset of tumorigenesis and reduced the cumulative number of tumors, tumor volume and the average number of tumors/mouse. To establish a cause and effect relationship, we targeted the proteins involved in the cell death pathway. Bromelain treatment resulted in upregulation of p53 and Bax and subsequent activation of caspase 3 and caspase 9 with concomitant decrease in antiapoptotic protein Bcl-2 in mouse skin. Since persistent induction of cyclooxygenase-2 (Cox-2) is frequently implicated in tumorigenesis and is regulated by nuclear factor-kappa B (NF-{kappa}B), we also investigated the effect of bromelain on Cox-2 and NF-{kappa}B expression. Results showed that bromelain application significantly inhibited Cox-2 and inactivated NF-{kappa}B by blocking phosphorylation and subsequent degradation of I{kappa}B{alpha}. In addition, bromelain treatment attenuated DMBA-TPA-induced phosphorylation of extracellular signal-regulated protein kinase (ERK1/2), mitogen-activated protein kinase (MAPK) and Akt. Taken together, we conclude that bromelain induces apoptosis-related proteins along with inhibition of NF-{kappa}B-driven Cox-2 expression by blocking the MAPK and Akt/protein kinase B signaling in DMBA-TPA-induced mouse skin tumors, which may account for its anti-tumorigenic effects.

  15. Cyclooxygenase-2 knockdown using retinoic acid chalcone (RAC), a promising therapeutic strategy for colon cancer

    PubMed Central

    Jiang, Chao; Wang, Qiong; Xu, Zhe; Li, Wei-Su; Chen, Che; Yao, Xue-Quan; Liu, Fu-Kun

    2015-01-01

    Retinoic acid is an effective agent in the treatment of epithelial and hematological malignancies. The present study demonstrates that retinoic acid chalcone (RAC), an analogue of retinoic acid inhibits cell proliferation and induces apoptosis in HCT-15 and CT26.WT colon cancer cell lines. In HCT-15 cells the percentage of apoptotic cells increased from 32.4 ± 3, 45.0 ± 3 to 72.6 ± 5% respectively at 10, 15 and 20 μg/mL compared to 3.7% in control. Similarly in CT26.WT cells the percentage increased from 28.6 ± 3, 41.2 ± 3 to 65.4 ± 5% on treatment with 10, 15 and 20 μg/mL concentrations of RAC after 72 h compared to 2.9 ± 1% in control. Western blotting, fluorescence-activated cell sorting analysis and reverse transcription-PCR assays were used to investigate these effects. RAC inhibited the overexpression of COX-2, PGE2 and PGE2 receptor (EP1 and EP4) in the colon cancer cell lines. RAC mediated inhibition of cell growth and induction of apoptosis through COX-2 inhibition was also confirmed by treating the HCT-15 and CT26.WT colon cancer cells with COX-2 inhibitor, indomethacin and transfection of cells with COX-2 small interfering RNA. In nude mice with tumor xenografts, treatment with RAC-supplemented diet caused inhibition of COX-2, PGE2, and PGE2 receptors (EP1, EP3, and EP4) in tumors. Thus RAC can be a potential candidate for the treatment of colon cancer through the inhibition of COX-2 expression and subsequent inhibition of PGE2 and PGE2 receptors. PMID:26269760

  16. Protective effect of long-term angiotensin II inhibition.

    PubMed

    Basso, Nidia; Cini, Rosa; Pietrelli, Adriana; Ferder, León; Terragno, Norberto A; Inserra, Felipe

    2007-09-01

    Experimental studies indicate that angiotensin II (ANG II) through its type 1 receptor (AT(1)) promotes cardiovascular hypertrophy and fibrosis. Therefore, the aim of this study was to analyze whether chronic long-term inhibition of the renin-angiotensin system (RAS) can prevent most of the deleterious effects due to aging in the cardiovascular system of the normal rat. The main objective was to compare two strategies of ANG II blockade: a converting enzyme inhibitor (CEI) and an AT(1) receptor blocker (AT(1)RB). A control group remained untreated; treatment was initiated 2 wk after weaning. A CEI, enalapril (10 mg.kg(-1).day(-1)), or an AT(1)RB, losartan (30 mg.kg(-1).day(-1)), was used to inhibit the RAS. Systolic blood pressure, body weight, and water and food intake were recorded over the whole experimental period. Heart, aorta, and mesenteric artery weight as well as histological analysis of cardiovascular structure were performed at 6 and 18 mo. Twenty animals in each of the three experimental groups were allowed to die spontaneously. The results demonstrated a significant protective effect on the function and structure of the cardiovascular system in all treated animals. Changes observed at 18 mo of age in the hearts and aortas were quite significant, but each treatment completely abolished this deterioration. The similarity between the results detected with either enalapril or losartan treatment clearly indicates that most of the effects are exerted through AT(1) receptors. An outstanding finding was the significant and similar prolongation of life span in both groups of treated animals compared with untreated control animals. PMID:17557916

  17. [Prevention of colorectal cancer: acetylsalicyclic acid and cyclo-oxygenase-2 inhibitors are only partially effective].

    PubMed

    Kleibeuker, J H; de Vries, E G

    2003-11-01

    Acetylsalicylic acid was recently shown to inhibit the development of colorectal adenomas in subjects with a moderately increased risk for colorectal cancer. The mechanisms by which acetylsalicylic acid and other NSAIDs, including COX-2 inhibitors, exert this effect include: inhibition of COX-2, induction of apoptosis and induction of the P21 protein that controls the development of crypt cells. For the majority of the population, a healthy lifestyle and healthy eating habits are the best means of preventing colorectal cancer. In addition, population-wide screening should be encouraged. For people with an increased risk of colorectal cancer, acetylsalicylic acid only has a partial effect and therefore endoscopic surveillance is still indicated. Sulindac or celecoxib may be useful for patients with familial adenomatous polyposis and in particular for inhibiting the development of rectal adenomas after subtotal colectomy with ileorectal anastomosis. However, in these cases endoscopic surveillance is also still necessary.

  18. Preclinical pharmacology of robenacoxib: a novel selective inhibitor of cyclooxygenase-2.

    PubMed

    King, J N; Dawson, J; Esser, R E; Fujimoto, R; Kimble, E F; Maniara, W; Marshall, P J; O'Byrne, L; Quadros, E; Toutain, P L; Lees, P

    2009-02-01

    This manuscript reports the results of preclinical studies in the rat with robenacoxib, a novel selective cyclooxygenase (COX)-2 inhibitor. Robenacoxib selectively inhibited COX-2 in vitro as evidenced from COX-1:COX-2 IC50 ratios of 27:1 in purified enzyme preparations and >967:1 in isolated cell assays. Binding to COX-1 was rapid and readily reversible (dissociation t(1/2) < 1 min), whilst COX-2 binding was slowly reversible (t(1/2) = 25 min). In vivo, robenacoxib inhibited PGE2 production (an index of COX-2 inhibition) in lipopolysaccharide (LPS)-stimulated air pouches (ID50 0.3 mg/kg) and for at least 24 h in zymosan-induced inflammatory exudate (at 2 mg/kg). Robenacoxib was COX-1 sparing, as it inhibited serum TxB2 synthesis ex vivo (an index of COX-1 inhibition) only at very high doses (100 mg/kg but not at 2-30 mg/kg). Robenacoxib inhibited carrageenan-induced paw oedema (ID50 0.40-0.48 mg/kg), LPS-induced fever (ID50 1.1 mg/kg) and Randall-Selitto pain (10 mg/kg). Robenacoxib was highly bound to plasma protein (99.9% at 50 ng/mL in vitro). After intravenous dosing, clearance was 2.4 mL/min/kg and volume of distribution at steady-state was 306 mL/kg. Robenacoxib was preferentially distributed into inflammatory exudate; the AUC for exudate was 2.9 times higher than for blood and the MRT in exudate (15.9 h) was three times longer than in blood (5.3 h). Robenacoxib produced significantly less gastric ulceration and intestinal permeability as compared with the reference nonsteroidal anti-inflammatory drug (NSAID), diclofenac, and did not inhibit PGE2 or 6-keto PGF(1alpha) concentrations in the stomach and ileum at 30 mg/kg. Robenacoxib also had no relevant effects on kidney function at 30 mg/kg. In summary, results of preclinical studies in rats studies suggest that robenacoxib has an attractive pharmacological profile for potential use in the intended target species, cats and dogs.

  19. Entamoeba histolytica: inflammatory process during amoebic liver abscess formation involves cyclooxygenase-2 expression in macrophages and trophozoites.

    PubMed

    Gutiérrez-Alarcón, A; Moguel-Torres, M; Mata-Leyva, O; Cuellar-Nevárez, G; Siqueiros-Cendón, T; Erosa, G; Ramos-Martínez, E; Talamás-Rohana, P; Sánchez-Ramírez, B

    2006-11-01

    It has been demonstrated that expression of cyclooxygenase-2 (COX-2) isoform is induced by Entamoeba histolytica in macrophages and polymorphonuclear cells during amoebic liver abscess (ALA) formation in hamsters. Trophozoites present in the lesion were also positive for COX-2 signal. However, no cross reactivity of the anti-COX-2 antibody with protein extract of cultivated trophozoites was found. To clarify if trophozoites are involved in PGE(2) production during ALA development, COX-2 expression was detected by in situ hybridization and RT-PCR in liver tissue from intrahepatically infected hamsters. COX-2 mRNA was in polymorphonuclear cells since 4h postinfection, and subsequently, local macrophages expressed COX-2 mRNA in a similar way. Additionally, a positive signal for COX-2 mRNA expression was detected in E. histolytica trophozoites, suggesting that, in vivo, parasite COX expression may be an important mechanism to promote inflammation.

  20. Temporal and topographic profiles of cyclooxygenase-2 expression during 24 h of focal brain ishemia in rats.

    PubMed

    Yokota, Chiaki; Kaji, Tomohito; Kuge, Yuji; Inoue, Hiroyasu; Tamaki, Nagara; Minematsu, Kazuo

    2004-03-11

    Substantial increases in cyclooxygenase-2 (COX-2) mRNA and protein levels were demonstrated in the peri-infarct and focal ischemic areas after 3-24 and 12-24 h, respectively, in rats. In the ischemic core, significant increases in COX-2 mRNA followed 6 h of ischemia, though the peak level was about one-third of that in the peri-infarct area. Increases in COX-2 protein in the ischemic core were not observed during ischemic periods. Diffuse, neuronal COX-2 staining was found in peri-infarct areas as well as in discrete, immunoreactive neurons in the ischemic core. Robust increases in prostaglandin E2 levels in the peri-infarct area were demonstrated following 24 h of ischemia. Prostaglandin production as well as COX-2 expression in ischemic tissues depended on the degree and duration of the reduction in cerebral blood flow.

  1. Cyclic stretch induces cyclooxygenase-2 gene expression in vascular endothelial cells via activation of nuclear factor kappa-{beta}

    SciTech Connect

    Zhao, Haige; Hiroi, Toyoko; Hansen, Baranda S.; Rade, Jeffrey J.

    2009-11-27

    Vascular endothelial cells respond to biomechanical forces, such as cyclic stretch and shear stress, by altering gene expression. Since endothelial-derived prostanoids, such as prostacyclin and thromboxane A{sub 2}, are key mediators of endothelial function, we investigated the effects of cyclic stretch on the expression of genes in human umbilical vein endothelial cells controlling prostanoid synthesis: cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), prostacyclin synthase (PGIS) and thromboxane A{sub 2} synthase (TXAS). COX-2 and TXAS mRNAs were upregulated by cyclic stretch for 24 h. In contrast, PGIS mRNA was decreased and stretch had no effect on COX-1 mRNA expression. We further show that stretch-induced upregulation of COX-2 is mediated by activation of the NF-{kappa}{beta} signaling pathway.

  2. Lack of association between the cyclooxygenase 2 -765G>C polymorphism and prostate cancer risk: a meta-analysis.

    PubMed

    Feng, Y-Q; Li, Y U; Xiao, W-D; Wang, G-X; Li, Y O

    2015-01-01

    The aim of this study was to investigate the association between the cyclooxygenase 2 (COX2) -765G>C (rs20417) polymorphism and prostate cancer (PC) risk using meta-analysis. A systematic literature search was performed using the PubMed, Embase, Cochrane Library, and Google Scholar databases by using the terms "cyclooxygenase-2/COX-2/PTGs2", "polymorphism" or "variation", and "prostate" and "cancer" or "carcinoma" to identify relevant articles up to June 14, 2014. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were assessed for PC risk associated with COX2 -765G>C polymorphism using fixed- and random-effect models. We identified a total of nine publications, including 5952 cases and 5078 controls, to investigate the effect of COX2 -765G>C on PC risk, and found no significant association in any genetic model tested (CC vs GG: OR = 0.993, 95%CI = 0.923-1.068; GC+CC vs GG: OR = 1.041, 95%CI = 0.931-1.103; CC vs GC+GG: OR = 0.858, 95%CI = 0.689-1.067; CC vs GG: OR = 0.871, 95%CI = 0.689-1.086; GC vs GG: OR = 1.032, 95%CI = 0.945-1.127). Power analysis and tests for publication bias ensured the reliability of our results. This meta-analysis suggested that the functional COX2 -765G>C polymorphism, located in the COX2 gene promoter, is unlikely to be associated with PC risk. However, additional larger, well-designed studies are still required to reach a conclusive result on this issue. PMID:26535654

  3. Clinical significance of cyclooxygenase-2 expression in extranodal natural killer (NK)/T-cell lymphoma, nasal type

    SciTech Connect

    Shim, Su Jung; Yang, Woo-Ick; Shin, Eunah; Koom, Woong Sub; Kim, Yong Bae; Cho, Jae Ho; Suh, Chang Ok; Kim, Joo Hang; Kim, Gwi Eon . E-mail: gekim@yumc.yonsei.ac.kr

    2007-01-01

    Purpose: To determine whether there are any differences in therapeutic response, patterns of systemic recurrence, and prognosis of patients with extranodal natural killer (NK)/T-cell lymphoma, nasal type, by the cyclooxygenase-2 (COX-2) expression. Patients and Methods: Thirty-four patients with Ann Arbor Stage I and II extranodal NK/T-cell lymphoma who underwent chemotherapy or radiotherapy, or both, were retrospectively reviewed. These patients were divided into two groups according to their immunohistochemical staining for COX-2 expressions: a COX-2-negative group (n = 10 patients) and a COX-2-positive group (n = 24 patients). The treatment response, patterns of treatment failure, and survival data for the patients were compared between the COX-2-positive and negative groups. Results: There was no significant difference in the clinical profiles between the COX-2-negative and COX-2-positive groups. All patients (100%) in the COX-2-negative group achieved complete response after initial treatment, whereas only 14 patients (58%) in the COX-2-positive group achieved complete response (p = 0.03). Compared with the patients in the COX-2-negative group, those in the COX-2-positive group had a significantly lower 2-year systemic recurrence-free survival rate (100% for the COX-2-negative group vs. 54% for the COX-2-positive group) (p = 0.02) and a decreased 5-year overall survival rate (70% for the COX-2-negative group vs. 32% for the COX-2-positive group) (p = 0.06). Conclusion: Cyclooxygenase-2 expression can serve as a predictive factor for poor treatment response, higher systemic recurrence, and unfavorable prognosis in patients with extranodal NK/T-cell lymphoma, nasal type.

  4. Silkworm Thorn Stem Extract Targets RSK2 and Suppresses Solar UV-Induced Cyclooxygenase-2 Expression.

    PubMed

    Kim, Jong-Eun; Lee, Ki Won

    2015-01-01

    Excessive exposure to solar UV (sUV) is associated with numerous human skin disorders, such as carcinogenesis, skin photoaging and skin inflammation. Silkworm Thorn (Cudraniatricuspidata, SW) is a plant belonging to the Moraceae family and widely present throughout Korea, China, and Japan. Most parts of the tree (including the fruit, leaf, stem, root, and bark) is consumable as a functional food or tea. In this study, we found that SW extract (SWE) inhibited the elevated expression of sUV-induced cyclooxygenase (COX)-2 levels in both HaCaT and JB6 cells. Levels of nuclear factor-κB and activator protein-1, two crucial transcription factors involved in COX-2 expression, were elevated by sUV treatment. Treatment with SWE abolished this activation. SWE also inhibited sUV-induced histone H3 phosphorylation. However, sUV-induced phosphorylation of Akt, c-Jun N-terminal kinase and p38 kinase remained unchanged in the presence of SWE. SWE inhibited RSK2 activity, and pull-down assays using SWE-Sepharose beads revealed that SWE binds directly with RSK2 in an ATP-competitive manner. These results suggest a potential for SWE to be developed as a cosmeceutical material and functional food constituent for the promotion of skin health. PMID:26506342

  5. Silkworm Thorn Stem Extract Targets RSK2 and Suppresses Solar UV-Induced Cyclooxygenase-2 Expression.

    PubMed

    Kim, Jong-Eun; Lee, Ki Won

    2015-01-01

    Excessive exposure to solar UV (sUV) is associated with numerous human skin disorders, such as carcinogenesis, skin photoaging and skin inflammation. Silkworm Thorn (Cudraniatricuspidata, SW) is a plant belonging to the Moraceae family and widely present throughout Korea, China, and Japan. Most parts of the tree (including the fruit, leaf, stem, root, and bark) is consumable as a functional food or tea. In this study, we found that SW extract (SWE) inhibited the elevated expression of sUV-induced cyclooxygenase (COX)-2 levels in both HaCaT and JB6 cells. Levels of nuclear factor-κB and activator protein-1, two crucial transcription factors involved in COX-2 expression, were elevated by sUV treatment. Treatment with SWE abolished this activation. SWE also inhibited sUV-induced histone H3 phosphorylation. However, sUV-induced phosphorylation of Akt, c-Jun N-terminal kinase and p38 kinase remained unchanged in the presence of SWE. SWE inhibited RSK2 activity, and pull-down assays using SWE-Sepharose beads revealed that SWE binds directly with RSK2 in an ATP-competitive manner. These results suggest a potential for SWE to be developed as a cosmeceutical material and functional food constituent for the promotion of skin health.

  6. Silkworm Thorn Stem Extract Targets RSK2 and Suppresses Solar UV-Induced Cyclooxygenase-2 Expression

    PubMed Central

    Kim, Jong-Eun; Lee, Ki Won

    2015-01-01

    Excessive exposure to solar UV (sUV) is associated with numerous human skin disorders, such as carcinogenesis, skin photoaging and skin inflammation. Silkworm Thorn (Cudraniatricuspidata, SW) is a plant belonging to the Moraceae family and widely present throughout Korea, China, and Japan. Most parts of the tree (including the fruit, leaf, stem, root, and bark) is consumable as a functional food or tea. In this study, we found that SW extract (SWE) inhibited the elevated expression of sUV-induced cyclooxygenase (COX)-2 levels in both HaCaT and JB6 cells. Levels of nuclear factor-κB and activator protein-1, two crucial transcription factors involved in COX-2 expression, were elevated by sUV treatment. Treatment with SWE abolished this activation. SWE also inhibited sUV-induced histone H3 phosphorylation. However, sUV-induced phosphorylation of Akt, c-Jun N-terminal kinase and p38 kinase remained unchanged in the presence of SWE. SWE inhibited RSK2 activity, and pull-down assays using SWE-Sepharose beads revealed that SWE binds directly with RSK2 in an ATP-competitive manner. These results suggest a potential for SWE to be developed as a cosmeceutical material and functional food constituent for the promotion of skin health. PMID:26506342

  7. Regulation of cyclooxygenase-2 expression by cAMP response element and mRNA stability in a human airway epithelial cell line exposed to zinc

    SciTech Connect

    Wu Weidong Silbajoris, Robert A.; Cao Dongsun; Bromberg, Philip A.; Zhang Qiao; Peden, David B.; Samet, James M.

    2008-09-01

    Exposure to zinc-laden particulate matter in ambient and occupational settings has been associated with proinflammatory responses in the lung. Cyclooxygenase 2-derived eicosanoids are important modulators of airway inflammation. In this study, we characterized the transcriptional and posttranscriptional events that regulate COX-2 expression in a human bronchial epithelial cell line BEAS-2B exposed to Zn{sup 2+}. Zn{sup 2+} exposure resulted in pronounced increases in COX-2 mRNA and protein expression, which were prevented by pretreatment with the transcription inhibitor actinomycin D, implying the involvement of transcriptional regulation. This was supported by the observation of increased COX-2 promoter activity in Zn{sup 2+}-treated BEAS-2B cells. Mutation of the cAMP response element (CRE), but not the {kappa}B-binding sites in the COX-2 promoter markedly reduced COX-2 promoter activity induced by Zn{sup 2+}. Inhibition of NF{kappa}B activation did not block Zn{sup 2+}-induced COX-2 expression. Measurement of mRNA stability demonstrated that Zn{sup 2+} exposure impaired the degradation of COX-2 mRNA in BEAS-2B cells. This message stabilization effect of Zn{sup 2+} exposure was shown to be dependent on the integrity of the 3'-untranslated region found in the COX-2 transcript. Taken together, these data demonstrate that the CRE and mRNA stability regulates COX-2 expression induced in BEAS-2B cells exposed to extracellular Zn{sup 2+}.

  8. Functional interaction between acyl-CoA synthetase 4, lipooxygenases and cyclooxygenase-2 in the aggressive phenotype of breast cancer cells.

    PubMed

    Maloberti, Paula M; Duarte, Alejandra B; Orlando, Ulises D; Pasqualini, María E; Solano, Angela R; López-Otín, Carlos; Podestá, Ernesto J

    2010-11-11

    The acyl-CoA synthetase 4 (ACSL4) is increased in breast cancer, colon and hepatocellular carcinoma. ACSL4 mainly esterifies arachidonic acid (AA) into arachidonoyl-CoA, reducing free AA intracellular levels, which is in contradiction with the need for AA metabolites in tumorigenesis. Therefore, the causal role of ACSL4 is still not established. This study was undertaken to determine the role of ACSL4 in AA metabolic pathway in breast cancer cells. The first novel finding is that ACSL4 regulates the expression of cyclooxygenase-2 (COX-2) and the production of prostaglandin in MDA-MB-231 cells. We also found that ACSL4 is significantly up-regulated in the highly aggressive MDA-MB-231 breast cancer cells. In terms of its overexpression and inhibition, ACSL4 plays a causal role in the control of the aggressive phenotype. These results were confirmed by the increase in the aggressive behaviour of MCF-7 cells stably transfected with a Tet-off ACSL4 vector. Concomitantly, another significant finding was that intramitochondrial AA levels are significantly higher in the aggressive cells. Thus, the esterification of AA by ACSL4 compartmentalizes the release of AA in mitochondria, a mechanism that serves to drive the specific lipooxygenase metabolization of the fatty acid. To our knowledge, this is the first report that ACSL4 expression controls both lipooxygenase and cyclooxygenase metabolism of AA. Thus, this functional interaction represents an integrated system that regulates the proliferating and metastatic potential of cancer cells. Therefore, the development of combinatory therapies that profit from the ACSL4, lipooxygenase and COX-2 synergistic action may allow for lower medication doses and avoidance of side effects.

  9. Coordinate up-regulation of low-density lipoprotein receptor and cyclo-oxygenase-2 gene expression in human colorectal cells and in colorectal adenocarcinoma biopsies

    NASA Technical Reports Server (NTRS)

    Lum, D. F.; McQuaid, K. R.; Gilbertson, V. L.; Hughes-Fulford, M.

    1999-01-01

    Many colorectal cancers have high levels of cyclo-oxygenase 2 (COX-2), an enzyme that metabolizes the essential fatty acids into prostaglandins. Since the low-density lipoprotein receptor (LDLr) is involved in the uptake of essential fatty acids, we studied the effect of LDL on growth and gene regulation in colorectal cancer cells. DiFi cells grown in lipoprotein-deficient sera (LPDS) grew more slowly than cells with LDL. LDLr antibody caused significant inhibition of tumor cell growth but did not affect controls. In addition, LDL uptake did not change in the presence of excess LDL, suggesting that ldlr mRNA lacks normal feedback regulation in some colorectal cancers. Analysis of the ldlr mRNA showed that excess LDL in the medium did not cause down-regulation of the message even after 24 hr. The second portion of the study examined the mRNA expression of ldlr and its co-regulation with cox-2 in normal and tumor specimens from patients with colorectal adenocarcinomas. The ratio of tumor:paired normal mucosa of mRNA expression of ldlr and of cox-2 was measured in specimens taken during colonoscopy. ldlr and cox-2 transcripts were apparent in 11 of 11 carcinomas. There was significant coordinate up-regulation both of ldlr and of cox-2 in 6 of 11 (55%) tumors compared with normal colonic mucosa. There was no up-regulation of cox-2 without concomitant up-regulation of ldlr. These data suggest that the LDLr is abnormally regulated in some colorectal tumors and may play a role in the up-regulation of cox-2. Copyright 1999 Wiley-Liss, Inc.

  10. Induction of cyclooxygenase-2 mRNA and protein expression by epoxy resin and zinc oxide-eugenol based root canal sealers in human osteoblastic cells.

    PubMed

    Huang, Fu-Mei; Chou, Ming-Yung; Chang, Yu-Chao

    2003-05-01

    An ideal root canal sealer should be nonirritating to the surrounding tissues. Unfortunately, all histological investigation demonstrated that all types of root canal sealer can induce mild to severe inflammatory alternations. However, there is little information on the precise mechanisms about root canal sealers-induced inflammatory reaction. Cyclooxygenase-2 (COX-2) is an inducible enzyme believed to be responsible for prostaglandin synthesis at site of inflammation. The aim of the present study was to investigate the effects of epoxy resin (AH26) and zinc oxide-eugenol based (Endomethansone and N2) root canal sealers on the expression of COX-2 mRNA gene and protein in cultured human osteoblastic cells. Investigations of the time dependence of COX-2 mRNA expression in root canal sealer-treated human osteoblastic cells revealed a rapid accumulation of the transcript, a significant signal first detectable within 2h and diminished to control level after 24h. In addition, all root canal sealers also induced COX-2 protein expression in human osteoblastic cells. Furthermore, to elucidate whether induction of COX-2 is associated with cytotoxicity, NS-398 (a selective COX-2 inhibitor), was added to test its protective effects. NS-398 at non-cytotoxic dose is not able to prevent root canal sealers-induced cytotoxicity. Taken together, the activation of COX-2 expression may be one of the pathogenesis of root canal sealers-induced periapical inflammation. In addition, root canal sealers-induced cytotoxicity is not directly via the induction of COX-2 expression.

  11. SIRT1 Suppresses Activator Protein-1 Transcriptional Activity and Cyclooxygenase-2 Expression in Macrophages*

    PubMed Central

    Zhang, Ran; Chen, Hou-Zao; Liu, Jin-Jing; Jia, Yu-Yan; Zhang, Zhu-Qin; Yang, Rui-Feng; Zhang, Yuan; Xu, Jing; Wei, Yu-Sheng; Liu, De-Pei; Liang, Chih-Chuan

    2010-01-01

    SIRT1 (Sirtuin type 1), a mammalian orthologue of yeast SIR2 (silent information regulator 2), has been shown to mediate a variety of calorie restriction (CR)-induced physiological events, such as cell fate regulation via deacetylation of the substrate proteins. However, whether SIRT1 deacetylates activator protein-1 (AP-1) to influence its transcriptional activity and target gene expression is still unknown. Here we demonstrate that SIRT1 directly interacts with the basic leucine zipper domains of c-Fos and c-Jun, the major components of AP-1, by which SIRT1 suppressed the transcriptional activity of AP-1. This process requires the deacetylase activity of SIRT1. Notably, SIRT1 reduced the expression of COX-2, a typical AP-1 target gene, and decreased prostaglandin E2 (PGE2) production of peritoneal macrophages (pMΦs). pMΦs with SIRT1 overexpression displayed improved phagocytosis and tumoricidal functions, which are associated with depressed PGE2. Furthermore, SIRT1 protein level was up-regulated in CR mouse pMΦs, whereas elevated SIRT1 decreased COX-2 expression and improved PGE2-related macrophage functions that were reversed following inhibition of SIRT1 deacetylase activity. Thus, our results indicate that SIRT1 may be a mediator of CR-induced macrophage regulation, and its deacetylase activity contributes to the inhibition of AP-1 transcriptional activity and COX-2 expression leading to amelioration of macrophage function. PMID:20042607

  12. P38 AND EGF RECEPTOR KINASE-MEDIATED ACTIVATION OF THE PHOSPHATIDYLINOSITOL 3-KINASE/AKT PATHWAY IS REQUIRED FOR ZN2+INDUCED CYCLOOXYGENASE-2 EXPRESSION

    EPA Science Inventory

    Cyclooxygenase 2 (COX-2) expression is induced by physiological and inflammatory stimuli. Regulation of COX-2 expression is stimulus- and cell type-specific. Exposure to Zn2+ has been associated with activation of multiple intracellular signaling pathways as well as the induction...

  13. The G-765C promoter polymorphism in cyclooxygenase-2 (PTGS2), aspirin utilization and cardiovascular disease risk: the Atherosclerosis Risk in Communities (ARIC) study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cyclooxygenase-2 derived prostaglandins modulate cardiovascular disease risk. We sought to determine if the reduced function G-765C promoter polymorphism in PTGS2 was associated with incident coronary heart disease (CHD) or ischemic stroke risk, and if this was modified by aspirin utilization. Usin...

  14. Cell cycle regulation and apoptotic cell death in experimental colon carcinogenesis: intervening with cyclooxygenase-2 inhibitors.

    PubMed

    Saini, Manpreet Kaur; Sanyal, Sankar Nath

    2015-01-01

    Relative imbalance in the pathways regulating cell cycle, cell proliferation, or cell death marks a prerequisite for neoplasm. C-phycocyanin, a biliprotein from Spirulina platensis and a selective COX-2 inhibitor along with piroxicam, a traditional nonsteroidal antiinflammatory drug was used to investigate the role of cell cycle regulatory proteins and proinflammatory transcription factor NFκB in 1,2-dimethylhydrazine dihydrochloride (DMH)-induced rat colon carcinogenesis. Cell cycle regulators [cyclin D1, cyclin E, cyclin dependent kinase 2 (CDK2), CDK4, and p53], NFκB (p65) pathway, and proliferating cell nuclear antigen (PCNA) were evaluated by gene and protein expression, whereas apoptosis was studied by terminal deoxynucleotidyl transferase dUTP nick end labeling and apoptotic bleb assay. Molecular docking of ligand protein interaction was done to validate the in vivo results. Cyclin D1, cyclin E, CDK2, and CDK4 were overexpressed in DMH, whereas piroxicam and c-phycocyanin promoted the cell cycle arrest by downregulating them. Both drugs mediated apoptosis through p53 activation. Piroxicam and c-phycocyanin also stimulated antiproliferation by restraining PCNA expression and reduced cell survival via inhibiting NFκB (p65) pathway. Molecular docking revealed that phycocyanobilin (a chromophore of c-phycocyanin) interact with DNA binding site of NFκB. Inhibition of cyclin/CDK complex by piroxicam and c-phycocyanin affects the expression of p53 in colon cancer followed by downregulation of NFκB and PCNA levels, thus substantiating the antineoplastic role of these agents. PMID:25825916

  15. Cyclooxygenase-2 in Endothelial and Vascular Smooth Muscle Cells Restrains Atherogenesis in Hyperlipidemic Mice

    PubMed Central

    Tang, Soon Yew; Monslow, James; Todd, Leslie; Lawson, John; Puré, Ellen; FitzGerald, Garret A.

    2014-01-01

    Background Placebo controlled trials of nonsteroidal antinflammatory drugs (NSAIDs) selective for inhibition of COX-2 reveal an emergent cardiovascular hazard in patients selected for low risk of heart disease. Postnatal global deletion of COX-2 accelerates atherogenesis in hyperlipidemic mice, a process delayed by selective enzyme deletion in macrophages. Methods and Results Here, selective depletion of COX-2 in vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) depressed biosynthesis of prostaglandin (PG)I2 and PGE2, elevated blood pressure and accelerated atherogenesis in Ldlr knockout (KO) mice. Deletion of COX-2 in VSMCs and ECs coincided with an increase in COX-2 expression in lesional macrophages and increased biosynthesis of thromboxane. Increased accumulation of less organized intimal collagen, laminin, α-smooth muscle actin and matrix-rich fibrosis was also apparent in lesions of the mutants. Conclusions Although atherogenesis is accelerated in global COX-2 KOs, consistent with evidence of risk transformation during chronic NSAID administration, this masks the contrasting effects of enzyme depletion in macrophages versus VSMCs and ECs. Targeting delivery of COX-2 inhibitors to macrophages may conserve their efficacy while limiting cardiovascular risk. PMID:24519928

  16. Isoorientin, a Selective Inhibitor of Cyclooxygenase-2 (COX-2) from the Tubers of Pueraria tuberosa.

    PubMed

    Sumalatha, Manne; Munikishore, Rachakunta; Rammohan, Aluru; Gunasekar, Duvvuru; Kumar, Kotha Anil; Reddy, Kakularam Kumar; Azad, Rajaram; Reddanna, Pallu; Bodo, Bernard

    2015-10-01

    Bioassay-guided fraction of the methanol extract of the roots of Pueraria tuberose DC yielded puerarin, an isoflavone C-glycoside (PT-1), isoorientin, a flavone C-glycoside (PT-2) and mangiferin, a xanthone C-glycoside (PT-3). The extracts and the isolated compounds were screened for potent anti-inflammatory components inhibiting the cyclooxygenases (COX-1 and COX-2) and 5-lipoxygenase (5-LOX), the target enzymes of inflammation, by employing spectroscopic/polorographic methods. Among these, isoorientin was found to be a potent inhibitor of COX-2with an IC50 value of 39 μM. Docking studies were carried out to understand the interactions of isorientin (PT-2) with COX-2.The structures of the isolates were determined by mass spectrometry and 2D-NMR techniques including HSQC, HMBC, NOESY and 1H-1H COSY experiments. Although isoorientin and mangiferin have been reported from several plant sources, this is the first report of their isolation from a Pueraria species. PMID:26669106

  17. Inhibitory effect of dihydroartemisinin against phorbol ester-induced cyclooxygenase-2 expression in macrophages.

    PubMed

    Kim, Hyung Gyun; Yang, Ji Hye; Han, Eun Hee; Choi, Jae Ho; Khanal, Tilak; Jeong, Myung Ho; Jeong, Tae Cheon; Jeong, Hye Gwang

    2013-06-01

    Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin isolated from the traditional Chinese herb Artemisia annua L., has recently been shown to possess antitumor activity in various cancer cells. However, the effect of anti-inflammatory potentials of DHA in murine macrophage RAW 264.7 cells has not been studied. The present study investigated the effect of COX-2 and molecular mechanisms by DHA in PMA stimulated RAW 264.7 cells. DHA dose-dependently decreased PMA-induced COX-2 expression and PGE2 production, as well as COX-2 promoter-driven luciferase activity. Additionally, DHA decreased luciferase activity of COX-2 regulation-related transcription factors including NF-κB, AP-1, C/EBP and CREB. DHA also remarkably reduced PMA-induced p65, C/EBPβ, c-jun and CREB nuclear translocation. Furthermore, DHA evidently inhibited PMA-induced phosphorylation of AKT and the MAP Kinases, such as ERK, JNK and p38. Taken together, our data indicated that DHA effectively attenuates COX-2 production via down-regulation of AKT and MAPK pathway, revealing partial molecular basis for the anti-inflammatory properties of DHA. PMID:23429041

  18. Synthesis and characterization of novel oxazines and demonstration that they specifically target cyclooxygenase 2.

    PubMed

    Srinivas, V; Mohan, Chakrabhavi Dhananjaya; Baburajeev, C P; Rangappa, Shobith; Jagadish, Swamy; Fuchs, Julian E; Sukhorukov, Alexey Yu; Chandra; Mason, Daniel J; Sharath Kumar, Kothanahally Shivaramu; Madegowda, Mahendra; Bender, Andreas; Basappa; Rangappa, Kanchugarakoppal Subbegowda

    2015-08-01

    In the present study, we used solution combustion synthesis-bismuth oxide (Bi2O3) as catalyst for the simple and efficient synthesis of 1,2-oxazine based derivatives of 6-fluoro-3-(piperidin-4-yl)benzo[d]isoxazoles, 1-arylpiperazine and carbazoles. (4aR,8aR)-4-(4-Methoxyphenyl)-3-((4-(4-methoxyphenyl)piperazin-1-yl)methyl)-4a,5,6,7,8,8a-hexahydro-4H-benzo[e][1,2]oxazine was found to be the most potent compound with a high degree of selectivity in inhibition towards COX2 (1.7 μM) over COX1 (40.4 μM) demonstrating the significance of 1,2-oxazine derivatives in developing COX2 specific inhibitors. Molecular docking analyses demonstrated that an isoleucine residue in the active site of COX1 is responsible for lower affinity to COX1 and increased potency towards COX2. Overall, our study reveals that the new 1,2-oxazine-based small molecules qualify as lead structures in developing COX2-specific inhibitors for anti-inflammatory therapy. PMID:26048794

  19. Clinical pharmacology of lumiracoxib: a selective cyclo-oxygenase-2 inhibitor.

    PubMed

    Rordorf, Christiane M; Choi, Les; Marshall, Paul; Mangold, James B

    2005-01-01

    Lumiracoxib (Prexige) is a selective cyclo-oxygenase (COX)-2 inhibitor developed for the treatment of osteoarthritis, rheumatoid arthritis and acute pain. Lumiracoxib possesses a carboxylic acid group that makes it weakly acidic (acid dissociation constant [pKa] 4.7), distinguishing it from other selective COX-2 inhibitors. Lumiracoxib has good oral bioavailability (74%). It is rapidly absorbed, reaching maximum plasma concentrations 2 hours after dosing, and is highly plasma protein bound. Lumiracoxib has a short elimination half-life from plasma (mean 4 hours) and demonstrates dose-proportional plasma pharmacokinetics with no accumulation during multiple dosing. In patients with rheumatoid arthritis, peak lumiracoxib synovial fluid concentrations occur 3-4 hours later than in plasma and exceed plasma concentrations from 5 hours after dosing to the end of the 24-hour dosing interval. These data suggest that lumiracoxib may be associated with reduced systemic exposure, while still reaching sites where COX-2 inhibition is required for pain relief. Lumiracoxib is metabolised extensively prior to excretion, with only a small amount excreted unchanged in urine or faeces. Lumiracoxib and its metabolites are excreted via renal and faecal routes in approximately equal amounts. The major metabolic pathways identified involve oxidation of the 5-methyl group of lumiracoxib and/or hydroxylation of its dihaloaromatic ring. Major metabolites of lumiracoxib in plasma are the 5-carboxy, 4'-hydroxy and 4'-hydroxy-5-carboxy derivatives, of which only the 4'-hydroxy derivative is active and COX-2 selective. In vitro, the major oxidative pathways are catalysed primarily by cytochrome P450 (CYP) 2C9 with very minor contribution from CYP1A2 and CYP2C19. However, in patients genotyped as poor CYP2C9 metabolisers, exposure to lumiracoxib (area under the plasma concentration-time curve) is not significantly increased compared with control subjects, indicating no requirement for adjustment

  20. Misoprostol Reverse Hippocampal Neuron Cyclooxygenase-2 Downstream Signaling Imbalance in Aluminum-Overload Rats

    PubMed Central

    Guo, Yuanxin; Lei, Wenjuan; Wang, Jianfeng; Hu, Xinyue; Wei, Yuling; Ji, Chaonan; Yang, Junqing

    2016-01-01

    Although COX-2 inhibition in animal models of neurodegenerative diseases has shown neuroprotection, recent studies have revealed some serious side effects (ulcers, bleeding, fatal cerebrovascular diseases etc.) and the limited benefits of COX-2 inhibitors. A more focused approach is necessary to explore the therapeutic effect of the COX downstream signaling pathway in neurological research. The aim of this study was to explore the alterations of the PGES-PGE2-EP signal pathway and the effect of misoprostol on neurodegeneration by chronic aluminum-overload in rats. Adult rats were treated by intragastric administration of aluminum gluconate. The PGE2 content and expression of PGES and EPs in the hippocampi of rats were detected using ELISA, q-PCR and Western blot analysis, respectively. The content of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) in the rat hippocampi were also detected. The misoprostol treatment dose-dependently improved spatial learning and memory function as well as healing after hippocampal neuron damage induced by chronic aluminum-overload in rats. Meanwhile, the administration of misoprostol resulted in a decrease in the PGE2 level and down-regulation of the mPGES-1, EP2 and EP4 expression levels, while there was a dose-dependent up-regulation of EP3 expression. These results suggest that misoprostol possesses a neuroprotective property, and the mechanism involves affecting the EP3 level and reducing the endogenous production of PGE2 through a negative feedback mechanism, increasing the EP3 expression level, decreasing the EP2 and EP4 expression levels, and rebuilding the mPGES-1-PGE2-EP1-4 signal pathway balance. In this way, misoprostol has a counteractive effect on oxidant stress and inflammation in the central nervous system. The PGES-PGE2-EPs signaling pathway is a potential therapeutic strategy for treating neurodegeneration in patients. PMID:27033056

  1. Chronic elevation of IL-1β induces diuresis via a cyclooxygenase 2-mediated mechanism.

    PubMed

    Boesen, E I

    2013-07-15

    Chronic renal inflammation is an increasingly recognized phenomenon in multiple disease states, but the impact of specific cytokines on renal function is unclear. Previously, we found that 14-day interleukin-1β (IL-1β) infusion increased urine flow in mice. To determine the mechanism by which this occurs, the current study tested the possible involvement of three classical prodiuretic pathways. Chronic IL-1β infusion significantly increased urine flow (6.5 ± 1 ml/day at day 14 vs. 2.3 ± 0.3 ml/day in vehicle group; P < 0.05) and expression of cyclooxygenase (COX)-2, all three nitric oxide synthase (NOS) isoforms, and endothelin (ET)-1 in the kidney (P < 0.05 in all cases). Urinary prostaglandin E metabolite (PGEM) excretion was also significantly increased at day 14 of IL-1β infusion (1.21 ± 0.26 vs. 0.29 ± 0.06 ng/day in vehicle-infused mice; P = 0.001). The selective COX-2 inhibitor celecoxib markedly attenuated urinary PGEM excretion and abolished the diuretic response to chronic IL-1β infusion. In contrast, deletion of NOS3, or inhibition of NOS1 with L-VNIO, did not blunt the diuretic effect of IL-1β, nor did pharmacological blockade of endothelin ETA and ETB receptors with A-182086. Consistent with a primary effect on water transport, IL-1β infusion markedly reduced inner medullary aquaporin-2 expression (P < 0.05) and did not alter urinary Na⁺ or K⁺ excretion. These data indicate a critical role for COX-2 in mediating the effects of chronic IL-1β elevation on the kidney.

  2. Misoprostol Reverse Hippocampal Neuron Cyclooxygenase-2 Downstream Signaling Imbalance in Aluminum-Overload Rats.

    PubMed

    Guo, Yuanxin; Lei, Wenjuan; Wang, Jianfeng; Hu, Xinyue; Wei, Yuling; Ji, Chaonan; Yang, Junqing

    2016-01-01

    Although COX-2 inhibition in animal models of neurodegenerative diseases has shown neuroprotection, recent studies have revealed some serious side effects (ulcers, bleeding, fatal cerebrovascular diseases etc.) and the limited benefits of COX-2 inhibitors. A more focused approach is necessary to explore the therapeutic effect of the COX downstream signaling pathway in neurological research. The aim of this study was to explore the alterations of the PGES-PGE2-EP signal pathway and the effect of misoprostol on neurodegeneration by chronic aluminum-overload in rats. Adult rats were treated by intragastric administration of aluminum gluconate. The PGE2 content and expression of PGES and EPs in the hippocampi of rats were detected using ELISA, q-PCR and Western blot analysis, respectively. The content of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) in the rat hippocampi were also detected. The misoprostol treatment dose-dependently improved spatial learning and memory function as well as healing after hippocampal neuron damage induced by chronic aluminum-overload in rats. Meanwhile, the administration of misoprostol resulted in a decrease in the PGE2 level and down-regulation of the mPGES-1, EP2 and EP4 expression levels, while there was a dosedependent up-regulation of EP3 expression. These results suggest that misoprostol possesses a neuroprotective property, and the mechanism involves affecting the EP3 level and reducing the endogenous production of PGE2 through a negative feedback mechanism, increasing the EP3 expression level, decreasing the EP2 and EP4 expression levels, and rebuilding the mPGES-1-PGE2-EP1-4 signal pathway balance. In this way, misoprostol has a counteractive effect on oxidant stress and inflammation in the central nervous system. The PGES-PGE2-EPs signaling pathway is a potential therapeutic strategy for treating neurodegeneration in patients. PMID:27033056

  3. Genetic Variants in Cyclooxygenase- 2 Contribute to Post-treatment Pain among Endodontic Patients

    PubMed Central

    Applebaum, Elizabeth; Nackley, Andrea G.; Bair, Eric; Maixner, William; Khan, Asma A.

    2015-01-01

    Introduction Non-steroidal anti-inflammatory drugs (NSAIDs) have a well-established analgesic efficacy for inflammatory pain. These drugs exert their effect by inhibiting the enzyme cyclooxygenase (COX) and are commonly used for the management of pain following endodontic treatment. There are two distinct isoforms of COX: COX-1, which is constitutively expressed; and COX-2, which is primarily induced by inflammation. Previous studies have shown that functional human genetic variants of the COX-2 gene may explain individual variations in acute pain. The present study extends this work by examining the potential contribution of the two COX isoforms to pain after endodontic treatment. Methods Ninety-four patients treated by endodontic residents at the University of North Carolina School of Dentistry were enrolled into a prospective cohort study. Data on potential predictors of post-treatment pain was collected and all patients submitted saliva samples for genetic analysis. Non-surgical root canal therapy was performed and participants recorded pain levels for five days following. Results In this study, 63% of patients experienced at least mild pain after root canal therapy and 24% experienced moderate to severe pain. Presence of pretreatment pain was correlated with higher post-treatment pain (p=0.01). Elevated heart rate (p=0.02) and higher diastolic blood pressure (p=0.024) were also correlated with decreased post-treatment pain. Finally, we identified genetic variants in COX-2 (haplotype composed of rs2383515 G, rs5277 G, rs5275 T, and rs2206593 A) associated with post-treatment pain following endodontic treatment (p= 0.025). Conclusion Understanding the genetic basis of pain following endodontic treatment will advance its prevention and management. PMID:26081267

  4. Cyclooxygenase 2-implications on maintenance of gastric mucosal integrity and ulcer healing: controversial issues and perspectives.

    PubMed

    Halter, F; Tarnawski, A S; Schmassmann, A; Peskar, B M

    2001-09-01

    Cyclooxygenase (COX), the key enzyme for synthesis of prostaglandins, exists in two isoforms (COX-1 and COX-2). COX-1 is constitutively expressed in the gastrointestinal tract in large quantities and has been suggested to maintain mucosal integrity through continuous generation of prostaglandins. COX-2 is induced predominantly during inflammation. On this premise selective COX-2 inhibitors not affecting COX-1 in the gastrointestinal tract mucosa have been developed as gastrointestinal sparing anti-inflammatory drugs. They appear to be well tolerated by experimental animals and humans following acute and chronic (three or more months) administration. However, there is increasing evidence that COX-2 has a greater physiological role than merely mediating pain and inflammation. Thus gastric and intestinal lesions do not develop when COX-1 is inhibited but only when the activity of both COX-1 and COX-2 is suppressed. Selective COX-2 inhibitors delay the healing of experimental gastric ulcers to the same extent as non-COX-2 specific non-steroidal anti-inflammatory drugs (NSAIDs). Moreover, when given chronically to experimental animals, they can activate experimental colitis and cause intestinal perforation. The direct involvement of COX-2 in ulcer healing has been supported by observations that expression of COX-2 mRNA and protein is upregulated at the ulcer margin in a temporal and spatial relation to enhanced epithelial cell proliferation and increased expression of growth factors. Moreover, there is increasing evidence that upregulation of COX-2 mRNA and protein occurs during exposure of the gastric mucosa to noxious agents or to ischaemia-reperfusion. These observations support the concept that COX-2 represents (in addition to COX-1) a further line of defence for the gastrointestinal mucosa necessary for maintenance of mucosal integrity and ulcer healing.

  5. Rust-inhibition fluids protect OCTGs in storage

    SciTech Connect

    Levesque, C.J.

    1985-03-01

    Here's a quick look at some common misconceptions that can lead to severe tubular goods damage caused by rust. Recommendations are given for correctly using thread compounds, thread protectors, coatings and inhibiting fluids.

  6. The functional interaction between Acyl-CoA synthetase 4, 5-lipooxygenase and cyclooxygenase-2 controls tumor growth: a novel therapeutic target.

    PubMed

    Orlando, Ulises D; Garona, Juan; Ripoll, Giselle V; Maloberti, Paula M; Solano, Ángela R; Avagnina, Alejandra; Gomez, Daniel E; Alonso, Daniel F; Podestá, Ernesto J

    2012-01-01

    The acyl-CoA synthetase 4 (ACSL4), which esterify mainly arachidonic acid (AA) into acyl-CoA, is increased in breast, colon and hepatocellular carcinoma. The transfection of MCF-7 cells with ACSL4 cDNA transforms the cells into a highly aggressive phenotype and controls both lipooxygenase-5 (LOX-5) and cyclooxygenase-2 (COX-2) metabolism of AA, suggesting a causal role of ACSL4 in tumorigenesis. We hypothesized that ACSL4, LOX-5 and COX-2 may constitute potential therapeutic targets for the control of tumor growth. Therefore, the aim of this study was to use a tetracycline Tet-Off system of MCF-7 xenograft model of breast cancer to confirm the effect of ACSL4 overexpression on tumor growth in vivo. We also aim to determine whether a combinatorial inhibition of the ACSL4-LOX-COX-2 pathway affects tumor growth in vivo using a xenograft model based on MDA-MB-231 cells, a highly aggressive breast cancer cell line naturally overexpressing ACSL4. The first novel finding is that stable transfection of MCF-7 cells with ACSL4 using the tetracycline Tet-Off system of MCF-7 cells resulted in development of growing tumors when injected into nude mice. Tumor xenograft development measured in animals that received doxycycline resulted in tumor growth inhibition. The tumors presented marked nuclear polymorphism, high mitotic index and low expression of estrogen and progesterone receptor. These results demonstrate the transformational capacity of ACSL4 overexpression. We examined the effect of a combination of inhibitors of ACSL4, LOX-5 and COX-2 on MDA-MB-231 tumor xenografts. This treatment markedly reduced tumor growth in doses of these inhibitors that were otherwise ineffective when used alone, indicating a synergistic effect of the compounds. Our results suggest that these enzymes interact functionally and form an integrated system that operates in a concerted manner to regulate tumor growth and consequently may be potential therapeutic targets for the control of

  7. Increased cyclooxygenase-2 and thromboxane synthase expression is implicated in diosgenin-induced megakaryocytic differentiation in human erythroleukemia cells.

    PubMed

    Cailleteau, C; Liagre, B; Battu, S; Jayat-Vignoles, C; Beneytout, J L

    2008-09-01

    Differentiation induction as a therapeutic strategy has, so far, the greatest impact in hematopoietic malignancies, most notably leukemia. Diosgenin is a very interesting natural product because, depending on the specific dose used, its biological effect is very different in HEL (human erythroleukemia) cells. For example, at 10 microM, diosgenin induced megakaryocytic differentiation, in contrast to 40 microM diosgenin, which induced apoptosis in HEL cells previously demonstrated using sedimentation field-flow fractionation (SdFFF). The goal of this work focused on the correlation between cyclooxygenase-2 (COX-2) and thromboxane synthase (TxS) and megakaryocytic differentiation induced by diosgenin in HEL cells. Furthermore, the technique of SdFFF, having been validated in our models, was used in this new study as an analytical tool that provided us with more or less enriched differentiated cell fractions that could then be used for further analyses of enzyme protein expression and activity for the first time. In our study, we showed the implication of COX-2 and TxS in diosgenin-induced megakaryocytic differentiation in HEL cells. Furthermore, we showed that the analytical technique of SdFFF may be used as a tool to confirm our results as a function of the degree of cell differentiation.

  8. Flaxseed oil increases aortic reactivity to phenylephrine through reactive oxygen species and the cyclooxygenase-2 pathway in rats

    PubMed Central

    2014-01-01

    Background Flaxseed oil has the highest concentration of omega-3 α-linolenic acid, which has been associated with cardiovascular benefit. However, the mechanism underlying the vascular effects induced through flaxseed oil is not well known. Thus, in the present study, we investigated the effects of flaxseed oil on vascular function in isolated rat aortic rings. Methods Wistar rats were treated daily with flaxseed oil or a control (mineral oil) intramuscular (i.m.) for fifteen days. Isolated aortic segments were used to evaluate cyclooxygenase-2 (COX-2) protein expression, superoxide anion levels and vascular reactivity experiments. Results Flaxseed oil treatment increased the vasoconstrictor response of aortic rings to phenylephrine. Endothelium removal increased the response to phenylephrine in aortic segments isolated from both groups, but the effect was smaller in the treated group. L-NAME incubation similarly increased the phenylephrine response in segments from both groups. The TXA2 synthase inhibitor furegrelate, the selective COX-2 inhibitor NS 398, the TP receptor antagonist SQ 29.548, the reactive oxygen species (ROS) scavenger apocynin, the superoxide anion scavengers tiron and the phospholipase A2 inhibitor dexamethasone partially reversed the flaxseed oil-induced increase in reactivity to phenylephrine. Conclusions These findings suggest that flaxseed oil treatment increased vascular reactivity to phenylephrine through an increase in ROS production and COX-2-derived TXA2 production. The results obtained in the present study provide new insight into the effects of flaxseed oil treatment (i.m.) on vascular function. PMID:24993607

  9. Vascular endothelial growth factor, matrix metalloproteinases, and cyclooxygenase-2 influence prognosis of uterine cervical cancer in young women.

    PubMed

    Noriyuki, Maiko; Sumi, Toshiyuki; Zhi, Xu; Misugi, Fumiko; Nobeyama, Hiroyuki; Yoshida, Hiroyuki; Matsumoto, Yoshinari; Yasui, Tomoyo; Honda, Ken-Ichi; Ishiko, Osamu

    2007-09-01

    Recent changes in the lifestyle of young women have led to an increase in the rate of uterine cervical cancer. We investigated the clinicopathological characteristics of uterine cervical cancer in young women, and examined the expression of vascular endothelial growth factor (VEGF), matrix metalloproteinases (MMPs) and cyclooxygenase-2 (COX-2). Tumor samples from 439 patients with uterine cervical cancer, who were initially treated at Osaka City University Medical School Hospital, Japan between 1995 and 2004, were stained immunohistochemically. The patients were classified into two groups according to age at onset: group Y included women aged < or =35 years, and group O included women aged > or =36 years. Group Y had more cases of squamous cell carcinoma, while group O had more advanced cases (P<0.05). Advanced cases (beyond stage Ib2) had a significantly worse prognosis in group Y than in group O (P<0.05). There were no differences between the two groups in the expressions of VEGF, MMP-2 and COX-2. However, in advanced cases (beyond stage Ib2), the expression of VEGF, MMP-2 and COX-2 was significantly greater in group Y than in group O (P<0.05). The above findings suggest that the expression of VEGF, MMPs and COX-2 is related to a worse prognosis for advanced uterine cervical cancer in young women.

  10. Differences in expression of uroplakin III, cytokeratin 7, and cyclooxygenase-2 in canine proliferative urothelial lesions of the urinary bladder.

    PubMed

    Sledge, D G; Patrick, D J; Fitzgerald, S D; Xie, Y; Kiupel, M

    2015-01-01

    The expression of immunohistochemical markers that have been used in diagnosis and/or prognostication of urothelial tumors in humans (uroplakin III [UPIII], cytokeratin 7 [CK7], cyclooxygenase-2 [COX-2], and activated caspase 3) was evaluated in a series of 99 canine proliferative urothelial lesions of the urinary bladder and compared to the lesion classification and grade as defined by the World Health Organization / International Society of Urologic Pathology consensus system. There were significant associations between tumor classification and overall UPIII pattern (P = 1.49 × 10(-18)), loss of UPIII (P = 1.27 × 10(-4)), overall CK7 pattern (P = 4.34 × 10(-18)), and COX-2 pattern (P = 8.12 × 10(-25)). In addition, there were significant associations between depth of neoplastic cell infiltration into the urinary bladder wall and overall UPIII pattern (P = 1.54 × 10(-14)), loss of UPIII (P = 2.07 × 10(-4)), overall CK7 pattern (P = 1.17 × 10(-13)), loss of CK7 expression (P = .0485), and COX-2 pattern (P = 8.23 × 10(-21)). There were no significant associations between tumor classification or infiltration and caspase 3 expression pattern.

  11. Cyclooxygenase-2 expression is associated with initiation of hepatocellular carcinoma, while prostaglandin receptor-1 expression predicts survival

    PubMed Central

    Yang, Hao-Jie; Jiang, Jing-Hang; Yang, Yu-Ting; Yang, Xiang-Di; Guo, Zhe; Qi, Ya-Peng; Zeng, Feng-Hua; Zhang, Ke-Lan; Chen, Neng-Zhi; Xiang, Bang-De; Li, Le-Qun

    2016-01-01

    AIM To determine whether cyclooxygenase-2 (COX-2) and prostaglandin E1 receptor (EP1) contribute to disease and whether they help predict prognosis. METHODS We retrospectively reviewed the records of 116 patients with hepatocellular carcinoma (HCC) who underwent surgery between 2008 and 2011 at our hospital. Expression of COX-2 and EP1 receptor was examined by immunohistochemistry of formalin-fixed, paraffin-embedded tissues using polyclonal antibodies. Possible associations between immunohistochemical scores and survival were determined. RESULTS Factors associated with poor overall survival (OS) were alpha-fetoprotein > 400 ng/mL, tumor size ≥ 5 cm, and high EP1 receptor expression, but not high COX-2 expression. Disease-free survival was not significantly different between patients with low or high levels of COX-2 or EP1. COX-2 immunoreactivity was significantly higher in well-differentiated HCC tissues (Edmondson grade I-II) than in poorly differentiated tissues (Edmondson grade III-IV) (P = 0.003). EP1 receptor immunoreactivity was significantly higher in poorly differentiated tissue than in well-differentiated tissue (P = 0.001). CONCLUSION COX-2 expression appears to be linked to early HCC events (initiation), while EP1 receptor expression may participate in tumor progression and predict survival.

  12. Expression of prostaglandin synthesizing enzymes (cyclooxygenase 1 and cyclooxygenase 2) in the ovary of the ostrich (Struthio camelus).

    PubMed

    Rodler, Daniela; Sinowatz, Fred

    2015-01-01

    Cyclooxygenase is the rate limiting enzyme in the production of prostaglandins. In birds two isoforms are present: cyclooxygenase 1 (COX-1) and cyclooxygenase 2 (COX-2). Despite evidence implicating that cyclooxygenases and PGs are critical factors in female reproduction in birds, little is known about COX expression in the avian ovary. In birds, cyclooxygenases have been studied in very few species only. In this study we report on the expression of COX-1 and COX-2 in the ovary of the ostrich (Struthio camelus) using immunohistochemistry and non-radioactive in situ hybridization techniques. Our results demonstrate that COX-1 is strongly expressed in the cytoplasm of oocytes of previtellogenic follicles, whereas COX-2 shows the strongest immunostaining in the granulosa cells of previtellogenic follicles. The signals of both isoenzymes fade significantly with increasing diameter and finally nearly vanish in the vitellogenic follicles with a size >1.8 cm. This expression pattern in the ostrich (S. camelus) is, therefore, completely different from the localization of COX-1 and COX-2 in the hen (Gallus gallus), a finding which also suggests different functions of the cyclooxygenases in the ostrich species. Non-radioactive in situ hybridization confirmed that COX-1 is synthesized in the ooplasm and COX-2 in the granulosa layers of early previtellogenic follicles. According to the results of this study it appears unlikely that COX-1 or COX-2 play a major role in ovulation and oviposition in the ostrich. PMID:25528171

  13. K-Ras and cyclooxygenase-2 coactivation augments intraductal papillary mucinous neoplasm and Notch1 mimicking human pancreas lesions

    PubMed Central

    Chiblak, Sara; Steinbauer, Brigitte; Pohl-Arnold, Andrea; Kucher, Dagmar; Abdollahi, Amir; Schwager, Christian; Höft, Birgit; Esposito, Irene; Müller-Decker, Karin

    2016-01-01

    Mutational activation of K-Ras is an initiating event of pancreatic ductal adenocarcinomas (PDAC) that may develop either from pancreatic intraepithelial neoplasia (PanIN) or intraductal papillary mucinous neoplasms (IPMN). Cyclooxygenase-2 (COX-2)-derived prostaglandin E2 (PGE2) is causally related to pancreatic carcinogenesis. Here, we deciphered the impact of COX-2, a key modulator of inflammation, in concert with active mutant K-RasG12D on tumor burden and gene expression signature using compound mutant mouse lines. Concomitant activation of COX-2 and K-RasG12D accelerated the progression of pancreatic intraepithelial lesions predominantly with a cystic papillary phenotype resembling human IPMN. Transcriptomes derived from laser capture microdissected preneoplastic lesions of single and compound mutants revealed a signature that was significantly enriched in Notch1 signaling components. In vitro, Notch1 signaling was COX-2-dependent. In line with these findings, human IPMN stratified into intestinal, gastric and pancreatobillary types displayed Notch1 immunosignals with high prevalence, especially in the gastric lesions. In conclusion, a yet unknown link between activated Ras, protumorigenic COX-2 and Notch1 in IPMN onset was unraveled. PMID:27381829

  14. Spatiotemporal expression of cyclooxygenase 1 and cyclooxygenase 2 during delayed implantation and the periimplantation period in the Western spotted skunk.

    PubMed

    Das, S K; Wang, J; Dey, S K; Mead, R A

    1999-04-01

    Embryonic development in the western spotted skunk is arrested after blastocyst formation for about 200 days. This developmental arrest is believed to be due to insufficiency of uterine conditions to support continuous development. Implantation and decidualization are defective in cyclooxygenase 2 (Cox2)-, but not Cox1-, deficient mice. We therefore used Northern and in situ hybridization to investigate changes in uterine expression of Cox1 and Cox2 genes during various stages of pregnancy in the spotted skunk. Cox1 was constitutively expressed at all stages of pregnancy examined, but it did exhibit localized up-regulation in the trophoblast and necks of uterine glands at early implantation sites. Cox2 expression was highly regulated with little or no expression during delayed implantation. Cox2 expression was first detected in the uterus and trophoblast prior to blastocyst attachment and remained detectable for 5-6 days after blastocyst attachment. Cox2 expression was also localized in the luminal and glandular epithelia of uterine segments located between implantation chambers. Changes in Cox expression were not correlated with the abrupt increase in uterine weight that occurs simultaneously with renewed embryonic development but was correlated with an influx of serum proteins into the uterus observed in a previous study.

  15. Effects of NSAIDs on proliferation of gastric cancer cells in vitro: possible implication of cyclooxygenase-2 in cancer development.

    PubMed

    Sawaoka, H; Kawano, S; Tsuji, S; Tsujii, M; Murata, H; Hori, M

    1998-01-01

    The roles of cyclooxygenase-2 (COX-2) in the development of gastric cancer are unknown. We investigated the effects of nonsteroidal antiinflammatory drugs (NSAIDs), which are specific and nonspecific inhibitors of COX-2, on proliferation of the gastric cancer cell lines KATOIII, MKN28, and MKN45. The protein level of COX-2 was examined in these cell lines by Western analysis, and mRNA levels of COX-1/2 by Northern analysis. These cell lines expressed comparable levels of COX-1 mRNA. However, mRNA and protein expression of COX-2 in these cell lines was different. MKN45 expressed higher levels of COX-2 mRNA and protein than KATOIII and MKN28. We also examined the effects of NS-398 and indomethacin, specific and nonspecific inhibitors of COX-2, on the increase in cell number and [3H]thymidine uptake of these cell lines. NS-398 and indomethacin suppressed proliferation of MKN45 cells that overexpressed COX-2, although they exerted minimal effects on proliferation of KATOIII and MKN28, which expressed lower levels of COX-2. These results are consistent with the hypothesis that COX-2 is expressed in certain groups of gastric cancers and is related to their cell proliferation. It was proposed that COX-2 plays an important role in development of gastric cancer cells. Furthermore, NSAIDs may exert antiproliferative activity against gastric adenocarcinomas that overexpress COX-2. PMID:9872498

  16. Prolactin (PRL) induction of cyclooxygenase 2 (COX2) expression and prostaglandin (PG) production in hamster Leydig cells.

    PubMed

    Matzkin, María Eugenia; Ambao, Verónica; Carino, Mónica Herminia; Rossi, Soledad Paola; González, Lorena; Turyn, Daniel; Campo, Stella; Calandra, Ricardo Saúl; Frungieri, Mónica Beatriz

    2012-01-01

    Serum prolactin (PRL) variations play a crucial role in the photoperiodic-induced testicular regression-recrudescence transition in hamsters. We have previously shown that cyclooxygenase 2 (COX2), a key enzyme in the biosynthesis of prostaglandins (PGs), is expressed mostly in Leydig cells of reproductively active hamsters with considerable circulating and pituitary levels of PRL. In this study, we describe a stimulatory effect of PRL on COX2/PGs in hamster Leydig cells, which is mediated by IL-1β and prevented by P38-MAPK and JAK2 inhibitors. Furthermore, by preparative isoelectric focusing (IEF), we isolated PRL charge analogues from pituitaries of active [isoelectric points (pI): 5.16, 4.61, and 4.34] and regressed (pI: 5.44) hamsters. More acidic PRL charge analogues strongly induced COX2 expression, while less acidic ones had no effect. Our studies suggest that PRL induces COX2/PGs in hamster Leydig cells through IL-1β and activation of P38-MAPK and JAK2. PRL microheterogeneity detected in active/inactive hamsters may be responsible for the photoperiodic variations of COX2 expression in Leydig cells.

  17. Quantitative Assessment of the Association of COX-2 (Cyclooxygenase-2) Immunoexpression with Prognosis in Human Osteosarcoma: A Meta-Analysis

    PubMed Central

    Xiao, Zengming; Wu, Hao; Wu, Yang

    2013-01-01

    Background Numerous studies examining the relationship between Cyclooxygenase-2 (COX-2) immunoexpression and clinical outcome in osteosarcoma patients have yielded inconclusive results. Methods We accordingly conducted a meta-analysis of 9 studies (442 patients) that evaluated the correlation between COX-2 immunoexpression and clinical prognosis (death). Pooled odds ratios (OR) and risk ratios (RR) with 95% confidence intervals (95% CI) were calculated using the random-effects or fixed-effects model. Results Meta–analysis showed no significant association between COX-2 positivity and age, gender, tumor location, histology, stage, metastasis or 90% necrosis. Conversely, COX-2 immunoexpression was associated with overall survival rate (RR=2.12; 95% CI: 1.10–3.74; P=0.009) and disease-free survival rate (RR=1.63; 95% CI: 1.17–2.28; P=0.004) at 2 years. Sensitivity analysis performed by omitting low quality studies showed that the pooled results were stable. Conclusions COX-2 positivity was associated with a lower 2-year overall survival rate and disease-free survival rate. COX-2 expression change is an independent prognostic factor in patients with osteosarcoma. PMID:24358237

  18. Dehydroepiandrosterone and metformin modulate progesterone-induced blocking factor (PIBF), cyclooxygenase 2 (COX2) and cytokines in early pregnant mice.

    PubMed

    Luchetti, C G; Mikó, E; Szekeres-Bartho, J; Paz, D A; Motta, A B

    2008-09-01

    The present study examined the mechanism by which metformin (N,N'-dimethylbiguanide) prevents embryonic resorption induced in mice by dehydroepiandrosterone (DHEA). Treatment with DHEA (60mg/kg, s.c. 24 and 48h post-implantation) induces embryo resorption of early pregnant BALB/c mice while simultaneous treatment with metformin (240mg/kg, oral 24 and 48h post-implantation) prevents it. During pregnancy progesterone-induced blocking factor (PIBF) modulates prostaglandins (PGs) and cytokine production. These findings prompted us to investigate the effect of DHEA and metformin on both PIBF and cyclooxygenase 2 (COX2) expressions at the implantation sites, as well as cytokine production. PIBF and COX2 expression were detected by immunohistochemistry from DHEA and DHEA+ metformin treated 8 days-pregnant mice and serum cytokine levels of these animals were determined by ELISA. DHEA treatment both abolished PIBF expression and increased COX2 expression. Embryo resorption correlates with the lack of PIBF expression, diminished IL-6 levels and increased IL-2 concentration while metformin was able to reverse the effect of DHEA on both PIBF and COX2 expression and IL-6 levels. We concluded that hyperandrogenization induces embryo resorption in early pregnancy diminishing PIBF in implantation sites, having a pro-inflammatory effect. Metformin is able to prevent such effects.

  19. Targeting the prostaglandin E2 EP1 receptor and cyclooxygenase-2 in the amygdala kindling model in mice.

    PubMed

    Fischborn, Sarah Verena; Soerensen, Jonna; Potschka, Heidrun

    2010-09-01

    The prostaglandin E2 EP1 receptor as well as the inflammatory enzyme cyclooxygenase-2 have been suggested as targets for disease modulation, improvement of therapeutic response, and restoration of pharmacosensitivity in epilepsies. Translational development of respective add-on approaches requires careful analysis of putative effects on ictogenesis. Therefore we evaluated the impact of the EP1 receptor antagonist SC-51089, the EP1 receptor agonist misoprostol and the COX-2 inhibitors celecoxib and NS-398 in the mouse amygdala kindling model of temporal lobe epilepsy. Neither celecoxib nor NS-398 affected the generation, spread and termination of seizure activity. Whereas SC-51089 did not affect the seizure threshold, the highest dose (30mg/kg) significantly decreased the seizure severity when administered 60min before stimulation. Moreover, SC-51089 significantly prolonged seizure duration at the highest dose. The EP1 receptor agonist misoprostol exerted contrasting effects on seizure duration with a significant decrease in the duration of motor seizure activity. The data suggest that doses of COX-2 inhibitors and EP1 receptor antagonists which exert disease modulating or antiepileptic drug potentiating effects do not negatively affect seizure control in temporal lobe epilepsy. The contrasting impact of the EP1 receptor antagonist and agonist suggests that EP1 receptors can influence endogenous mechanisms involved in termination of seizure activity.

  20. Hsp90 inhibition protects against inherited retinal degeneration

    PubMed Central

    Aguilà, Mònica; Bevilacqua, Dalila; McCulley, Caroline; Schwarz, Nele; Athanasiou, Dimitra; Kanuga, Naheed; Novoselov, Sergey S.; Lange, Clemens A.K.; Ali, Robin R.; Bainbridge, James W.; Gias, Carlos; Coffey, Peter J.; Garriga, Pere; Cheetham, Michael E.

    2014-01-01

    The molecular chaperone Hsp90 is important for the functional maturation of many client proteins, and inhibitors are in clinical trials for multiple indications in cancer. Hsp90 inhibition activates the heat shock response and can improve viability in a cell model of the P23H misfolding mutation in rhodopsin that causes autosomal dominant retinitis pigmentosa (adRP). Here, we show that a single low dose of the Hsp90 inhibitor HSP990 enhanced visual function and delayed photoreceptor degeneration in a P23H transgenic rat model. This was associated with the induction of heat shock protein expression and reduced rhodopsin aggregation. We then investigated the effect of Hsp90 inhibition on a different type of rod opsin mutant, R135L, which is hyperphosphorylated, binds arrestin and disrupts vesicular traffic. Hsp90 inhibition with 17-AAG reduced the intracellular accumulation of R135L and abolished arrestin binding in cells. Hsf-1−/− cells revealed that the effect of 17-AAG on P23H aggregation was dependent on HSF-1, whereas the effect on R135L was HSF-1 independent. Instead, the effect on R135L was mediated by a requirement of Hsp90 for rhodopsin kinase (GRK1) maturation and function. Importantly, Hsp90 inhibition restored R135L rod opsin localization to wild-type (WT) phenotype in vivo in rat retina. Prolonged Hsp90 inhibition with HSP990 in vivo led to a posttranslational reduction in GRK1 and phosphodiesterase (PDE6) protein levels, identifying them as Hsp90 clients. These data suggest that Hsp90 represents a potential therapeutic target for different types of rhodopsin adRP through distinct mechanisms, but also indicate that sustained Hsp90 inhibition might adversely affect visual function. PMID:24301679

  1. Intraplantar-injected ceramide in rats induces hyperalgesia through an NF-κB- and p38 kinase-dependent cyclooxygenase 2/prostaglandin E2 pathway

    PubMed Central

    Doyle, Tim; Chen, Zhoumou; Muscoli, Carolina; Obeid, Lina M.; Salvemini, Daniela

    2011-01-01

    Inflammatory pain represents an important unmet clinical need with important socioeconomic implications. Ceramide, a potent proinflammatory sphingolipid, has been shown to elicit mechanical hyperalgesia, but the mechanisms remain largely unknown. We now demonstrate that, in addition to mechanical hyperalgesia, intraplantar injection of ceramide (10 μg) led to the development of thermal hyperalgesia that was dependent on induction of the inducible cyclooxygenase (COX-2) and subsequent increase of prostaglandin E2 (PGE2). The development of mechanical and thermal hyperalgesia and increased production of PGE2 was blocked by NS-398 (15–150 ng), a selective COX-2 inhibitor. The importance of the COX-2 to PGE2 pathway in ceramide signaling was underscored by the findings that intraplantar injection of a monoclonal PGE2 antibody (4 μg) blocked the development of hyperalgesia. Our results further revealed that COX-2 induction is regulated by NF-κB and p38 kinase activation, since intraplantar injection of SC-514 (0.1–1 μg) or SB 203580 (1–10 μg), well-characterized inhibitors of NF-κB and p38 kinase activation, respectively, blocked COX-2 induction and increased formation of PGE2 and thermal hyperalgesia in a dose-dependent manner. Moreover, activation of NF-κB was dependent on upstream activation of p38 MAPK, since SB 203580 (10 μg) blocked p65 phosphorylation, whereas p38 kinase phosphorylation was unaffected by NF-κB inhibition by SC-514 (1 μg). Our findings not only provide mechanistic insight into the signaling pathways engaged by ceramide in the development of hyperalgesia, but also provide a potential pharmacological basis for developing inhibitors targeting the ceramide metabolic-to-COX-2 pathway as novel analgesics.—Doyle, T., Chen, Z., Muscoli, C., Obeid, L. M., Salvemini, D. Intraplantar-injected ceramide in rats induces hyperalgesia through an NF-κB- and p38 kinase-dependent cyclooxygenase 2/prostaglandin E2 pathway. PMID:21551240

  2. AIF inhibits tumor metastasis by protecting PTEN from oxidation.

    PubMed

    Shen, Shao-Ming; Guo, Meng; Xiong, Zhong; Yu, Yun; Zhao, Xu-Yun; Zhang, Fei-Fei; Chen, Guo-Qiang

    2015-11-01

    Apoptosis-inducing factor (AIF) exerts dual roles on cell death and survival, but its substrates as a putative oxidoreductase and roles in tumorigenesis remain elusive. Here, we report that AIF physically interacts with and inhibits the oxidation of phosphatase and tensin homolog on chromosome ten (PTEN), a tumor suppressor susceptible for oxidation-mediated inactivation. More intriguingly, we also identify PTEN as a mitochondrial protein and the ectopic expression of mitochondrial targeting sequence-carrying PTEN almost completely inhibits Akt phosphorylation in PTEN-deficient cells. AIF knockdown causes oxidation-mediated inactivation of the lipid phosphatase activity of PTEN, with ensuing activation of Akt kinase, phosphorylation of the Akt substrate GSK-3β, and activation of β-catenin signaling in cancer cells. Through its effect on β-catenin signaling, AIF inhibits epithelial-mesenchymal transition (EMT) and metastasis of cancer cells in vitro and in orthotopically implanted xenografts. Accordingly, the expression of AIF is correlated with the survival of human patients with cancers of multiple origins. These results identify PTEN as the substrate of AIF oxidoreductase and reveal a novel function for AIF in controlling tumor metastasis.

  3. Calmodulin kinase II inhibition protects against structural heart disease.

    PubMed

    Zhang, Rong; Khoo, Michelle S C; Wu, Yuejin; Yang, Yingbo; Grueter, Chad E; Ni, Gemin; Price, Edward E; Thiel, William; Guatimosim, Silvia; Song, Long-Sheng; Madu, Ernest C; Shah, Anisha N; Vishnivetskaya, Tatiana A; Atkinson, James B; Gurevich, Vsevolod V; Salama, Guy; Lederer, W J; Colbran, Roger J; Anderson, Mark E

    2005-04-01

    Beta-adrenergic receptor (betaAR) stimulation increases cytosolic Ca(2+) to physiologically augment cardiac contraction, whereas excessive betaAR activation causes adverse cardiac remodeling, including myocardial hypertrophy, dilation and dysfunction, in individuals with myocardial infarction. The Ca(2+)-calmodulin-dependent protein kinase II (CaMKII) is a recently identified downstream element of the betaAR-initiated signaling cascade that is linked to pathological myocardial remodeling and to regulation of key proteins involved in cardiac excitation-contraction coupling. We developed a genetic mouse model of cardiac CaMKII inhibition to test the role of CaMKII in betaAR signaling in vivo. Here we show CaMKII inhibition substantially prevented maladaptive remodeling from excessive betaAR stimulation and myocardial infarction, and induced balanced changes in excitation-contraction coupling that preserved baseline and betaAR-stimulated physiological increases in cardiac function. These findings mark CaMKII as a determinant of clinically important heart disease phenotypes, and suggest CaMKII inhibition can be a highly selective approach for targeting adverse myocardial remodeling linked to betaAR signaling.

  4. Comparison of nonsteroidal anti-inflammatory drugs and cyclooxygenase-2 (COX-2) inhibitors use in Australia and Nova Scotia (Canada)

    PubMed Central

    Barozzi, Nadia; Sketris, Ingrid; Cooke, Charmaine; Tett, Susan

    2009-01-01

    AIMS Cyclooxygenase-2 (COX-2) inhibitors were marketed aggressively and their rapid uptake caused safety concerns and budgetary challenges in Canada and Australia. The objectives of this study were to compare and contrast COX-2 inhibitors and nonselective nonsteroidal anti-inflammatory drug (ns-NSAID) use in Nova Scotia (Canada) and Australia and to identify lessons learned from the two jurisdictions. METHODS Ns-NSAID and COX-2 inhibitor Australian prescription data (concession beneficiaries) were downloaded from the Medicare Australia website (2001–2006). Similar Pharmacare data were obtained for Nova Scotia (seniors and those receiving Community services). Defined daily doses per 1000 beneficiaries day−1 were calculated. COX-2 inhibitors/all NSAIDs ratios were calculated for Australia and Nova Scotia. Ns-NSAIDs were divided into low, moderate and high risk for gastrointestinal side-effects and the proportions of use in each group were determined. Which drugs accounted for 90% of use was also calculated. RESULTS Overall NSAID use was different in Australia and Nova Scotia. However, ns-NSAID use was similar. COX-2 inhibitor dispensing was higher in Australia. The percentage of COX-2 inhibitor prescriptions over the total NSAID use was different in the two countries. High-risk NSAID use was much higher in Australia. Low-risk NSAID prescribing increased in Nova Scotia over time. The low-risk/high-risk ratio was constant throughout over the period in Australia and increased in Nova Scotia. CONCLUSIONS There are significant differences in Australia and Nova Scotia in use of NSAIDs, mainly due to COX-2 prescribing. Nova Scotia has a higher proportion of low-risk NSAID use. Interventions to provide physicians with information on relative benefits and risks of prescribing specific NSAIDs are needed, including determining their impact. PMID:19660008

  5. Comparison of benefit–risk preferences of patients and physicians regarding cyclooxygenase-2 inhibitors using discrete choice experiments

    PubMed Central

    Byun, Ji-Hye; Kwon, Sun-Hong; Lee, Ji-Eun; Cheon, Ji-Eun; Jang, Eun-Jin; Lee, Eui-Kyung

    2016-01-01

    Purpose To elucidate and compare benefit–risk preferences among Korean patients and physicians concerning cyclooxygenase-2 (Cox-2) inhibitor treatments for arthritis. Materials and methods Subjects included 100 patients with arthritis and 60 board-certified orthopedic surgeon physicians in South Korea. Through a systematic review of the literature, beneficial attributes of using Cox-2 inhibitors were defined as a decrease in the Western Ontario and McMaster Universities Arthritis Index for pain score and improvement in physical function. Likewise, risk attributes included upper gastrointestinal (GI) complications and cardiovascular (CV) adverse events. Discrete choice experiments were used to determine preferences for these four attributes among Korean patients and physicians. Relative importance and maximum acceptable risk for improving beneficial attributes were assessed by analyzing the results of the discrete choice experiment by using a conditional logit model. Results Patients ranked the relative importance of benefit–risk attributes as follows: pain reduction (35.2%); physical function improvement (30.0%); fewer CV adverse events (21.5%); fewer GI complications (13.4%). The physicians’ ranking for the same attributes was as follows: fewer CV (33.5%); pain reduction (32.4%); fewer GI complications (18.1%); physical function improvement (16.0%). Patients were more willing than physicians to accept risks when pain improved from 20% or 45% to 55% and physical function improved from 15% or 35% to 45%. Conclusion We confirmed that patients and physicians had different benefit–risk preferences regarding Cox-2 inhibitors. Patients with arthritis prioritized the benefits of Cox-2 inhibitors over the risks; moreover, in comparison with the physicians, arthritis patients were more willing to accept the trade-off between benefits and risks to achieve the best treatment level. To reduce the preference gap and achieve treatment goals, physicians must better

  6. Regulation of Cyclooxygenase-2 Expression by Heat: A Novel Aspect of Heat Shock Factor 1 Function in Human Cells

    PubMed Central

    Trotta, Edoardo; Angelini, Mara; Santoro, M. Gabriella

    2012-01-01

    The heat-shock response, a fundamental defense mechanism against proteotoxic stress, is regulated by a family of heat-shock transcription factors (HSF). In humans HSF1 is considered the central regulator of heat-induced transcriptional responses. The main targets for HSF1 are specific promoter elements (HSE) located upstream of heat-shock genes encoding cytoprotective heat-shock proteins (HSP) with chaperone function. In addition to its cytoprotective function, HSF1 was recently hypothesized to play a more complex role, regulating the expression of non-HSP genes; however, the non-canonical role of HSF1 is still poorly understood. Herein we report that heat-stress promotes the expression of cyclooxygenase-2 (COX-2), a key regulator of inflammation controlling prostanoid and thromboxane synthesis, resulting in the production of high levels of prostaglandin-E2 in human cells. We show that heat-induced COX-2 expression is regulated at the transcriptional level via HSF1-mediated signaling and identify, by in-vitro reporter gene activity assay and deletion-mutant constructs analysis, the COX-2 heat-responsive promoter region and a new distal cis-acting HSE located at position −2495 from the transcription start site. As shown by ChIP analysis, HSF1 is recruited to the COX-2 promoter rapidly after heat treatment; by using shRNA-mediated HSF1 suppression and HSE-deletion from the COX-2 promoter, we demonstrate that HSF1 plays a central role in the transcriptional control of COX-2 by heat. Finally, COX-2 transcription is also induced at febrile temperatures in endothelial cells, suggesting that HSF1-dependent COX-2 expression could contribute to increasing blood prostaglandin levels during fever. The results identify COX-2 as a human non-classical heat-responsive gene, unveiling a new aspect of HSF1 function. PMID:22347460

  7. Cyclooxygenase-2 Expression as a Predictor of Para-Aortic Lymph Node Recurrence in Uterine Cervical Cancer

    SciTech Connect

    Kim, Jun-Sang Li Shengjin; Kim, Jin-Man; Yeo, Seung-Gu; Kim, Ki-Hwan; Cho, Moon-June

    2008-04-01

    Purpose: The overexpression of cyclooxygenase-2 (COX-2) is associated with a worse prognosis and the development of distant metastases in cervical cancer. This matched-pair analysis examined whether COX-2 expression is associated with para-aortic lymph node (PALN) recurrence in uterine cervical cancer treated with radiotherapy (RT). Methods and Materials: For this study, we matched 20 patients with PALN recurrence after definitive or postoperative RT by stage with 20 others who did not have PALN recurrence. Of the 20 patients with PALN recurrence, definitive or postoperative RT was performed in 11 and 9 patients, respectively. COX-2 expression was assessed immunohistochemically using a mouse monoclonal antibody on formalin-fixed paraffin-embedded tumor specimens taken before RT. A logistic regression model was used to predict for PALN recurrence. Results: COX-2 was expressed in 28 (70%) of the 40 patients. The staining intensity was as follows: weak in 19 (47%), moderate in 6 (15%), and strong in 3 (8%) patients. The patients with PALN recurrence had much greater expression of COX-2 (17 patients, 85%) than did the control group (11 patients, 55%; p = 0.04). Strong staining intensity of COX-2 was seen only in the PALN recurrence group. The statistically significant factors associated with PALN recurrence were positive pelvic lymph nodes (odds ratio, 7.61; 95% confidence interval, 1.55-37.37; p = 0.01) and COX-2 expression (odds ratio, 1.47; 95% confidence interval, 1.04-2.09; p = 0.03). Conclusion: Our findings suggest that COX-2 overexpression in the initial tumor tissue might be associated with PALN recurrence after RT in cervical cancer patients.

  8. An investigation of the rate of cyclooxygenase-2 expression on the surface of adenomatous and colorectal adenocarcinoma polyps

    PubMed Central

    Baghaei, Ramin; Beiraghdar, Mozhdeh; Sobhani, Ahmad; Rafei, Rahmatolah; Kolahi, Leila; Foladi, Lotfolah

    2015-01-01

    Background: Colorectal cancer (CRC) (adenomatous, adenocarcinoma) is one of the major causes of mortality and morbidity in human societies. Considering the importance of cyclooxygenase-2 (COX-2) expression in the incidence of CRC, in this study, the rate of COX-2 gene expression on polyps and CRCs were addressed. Materials and Methods: This is a cross-sectional descriptive analytic study carried out on the blocks of sampled tissue of adenomatous and colorectal adenocarcinoma polyps on 68 patients referred to Digestive Clinic in Isfahan Shariati Hospital in 2013. Patients were divided into two groups of polyps (n = 52) and cancer (n = 16). Given the presence of CRC or polyps by colonoscopy, samples were sent to the laboratory to measure the rate of COX-2 gene expression using immunohistochemistry. Results: In polyp group, 41 individuals (78.8%) had two or <2 polyps, 24 cases (46.2%) had a tubular polyp, and about a third of all patients had a big polyp. The most frequency of the polyp site was related to sigmoid with 19 cases (36.54%), in cancer group, it was related to the rectum with 9 cases (56.25%) that there was no significant difference between two groups (P < 0.05). The overall prevalence of COX-2 expression was positive in 51 cases (75%) and negative in 17 cases (25%). COX-2 gene expression was separately observed in 38 individuals (73.10%) in the polyp group and in 13 cases (81.25%) in the cancer group, and no significant difference was found (P > 0.05). Conclusion: There is no relationship between COX-2 gene expression and the surface of adenomatous and colorectal adenocarcinoma polyps. PMID:26601088

  9. Enhanced cyclooxygenase-2 expression levels and metalloproteinase 2 and 9 activation by Hexachlorobenzene in human endometrial stromal cells.

    PubMed

    Chiappini, Florencia; Bastón, Juan Ignacio; Vaccarezza, Agustina; Singla, José Javier; Pontillo, Carolina; Miret, Noelia; Farina, Mariana; Meresman, Gabriela; Randi, Andrea

    2016-06-01

    Hexachlorobenzene (HCB) is an organochlorine pesticide that induces toxic reproductive effects in laboratory animals. It is a dioxin-like compound and a weak ligand of the aryl hydrocarbon receptor (AhR). Endometriosis is characterized by the presence of functional endometrial tissues outside the uterine cavity. Experimental studies indicate that exposure to organochlorines can interfere with both hormonal regulation and immune function to promote endometriosis. Altered expression of metalloproteinases (MMPs) in patients with endometriosis, suggests that MMPs may play a critical role. In the endometriotic lesions, prostaglandin E2 (PGE2) produced by cyclooxygenase-2 (COX-2), binds to its EP4 receptor (EP4), and via c-Src kinase induces MMPs activation, promoting endometriosis. We examined the HCB action on MMP-2 and MMP-9 activities and expression, COX-2 levels, PGE2 signaling, and the AhR involvement in HCB-induced effects. We have used different in vitro models: (1) human endometrial stromal cell line T-HESC, (2) primary cultures of Human Uterine Fibroblast (HUF), and (3) primary cultures of endometrial stromal cells from eutopic endometrium of control (CESC) and subjects with endometriosis (EESC). Our results show that HCB enhances MMP-2 and MMP-9 activities in T-HESC, HUF and ESC cells. The MMP-9 levels were elevated in all models, while the MMP-2 expression only increased in ESC cells. HCB enhanced COX-2 and EP4 expression, PGE2 secretion and the c-Src kinase activation in T-HESC. Besides, we observed that AhR is implicated in these HCB-induced effects. In conclusion, our results show that HCB exposure could contribute to endometriosis development, affecting inflammation and invasion parameters of human endometrial cells. PMID:27038655

  10. Analgesic Efficacy of Firocoxib, a Selective Inhibitor of Cyclooxygenase 2, in a Mouse Model of Incisional Pain

    PubMed Central

    Reddyjarugu, Balagangadharreddy; Pavek, Todd; Southard, Teresa; Barry, Jason; Singh, Bhupinder

    2015-01-01

    Pain management in laboratory animals is generally accomplished by using opioids and NSAIDs. However, opioid use is hindered by controlled substance requirements and a relatively short duration of action. In this study, we compared the analgesic efficacy of firocoxib (a cyclooxygenase-2-selective NSAID) with that of buprenorphine in the mouse model of plantar incisional pain by objective measurement of mechanical allodynia and thermal hyperalgesia using von Frey and Hargreaves equipment, respectively. Our experimental design included 5 treatment groups: firocoxib at 10 mg/kg IP every 24 h (F10 group); firocoxib at 20 mg/kg IP every 24 h (F20); buprenorphine at 0.2 mg/kg SC every 8 h; intraperitoneal normal saline every 24 h; and sham group (anesthesia, no incision) treated with firocoxib at 20 mg/kg IP every 24 h (sham+F20). All mice underwent nociceptive assays at 24 h before and 4, 24, 48, and 72 h after surgery. Buprenorphine alleviated allodynia at all time points after incision. The F10 treatment alleviated allodynia at 4, 24, and 48 h, whereas F20 alleviated allodynia at 24, 48, and 72 h. None of the treatments alleviated thermal hyperalgesia at 4h. Except for F10 and buprenorphine at 24 h, all treatments alleviated thermal hyperalgesia at 24, 48, and 72 h. No significant differences were noted between the 2 doses of firocoxib and buprenorphine regarding mechanical allodynia and thermal hyperalgesia at all time points. In conclusion, the analgesic efficacy of firocoxib is comparable to that of buprenorphine in this mouse pain model. PMID:26224441

  11. Involvement of cyclooxygenase-1 and cyclooxygenase-2 activity in the therapeutic effect of ghrelin in the course of ethanol-induced gastric ulcers in rats.

    PubMed

    Warzecha, Z; Ceranowicz, P; Dembinski, M; Cieszkowski, J; Ginter, G; Ptak-Belowska, A; Dembinski, A

    2014-02-01

    Previous studies have shown that treatment with ghrelin exhibits protective and therapeutic effects in the gut. Aim of our present investigation was to examine the influence of ghrelin administration on the healing of ethanol-induced gastric ulcers and determine the role of cyclooxygenase-1 and cyclooxygenase-2 in this effect. Our studies were performed on male Wistar rats. Gastric ulcers were induced by intragastric administration of 75% ethanol. Ghrelin alone or in combination with cyclooxygenase inhibitors was administered twice, 1 and 13 hours after ethanol application. Cyclooxygenase-1 (COX-1) inhibitor (SC-560, 10 mg/kg/dose) or COX-2 inhibitor (celecoxib, 10 mg/kg/dose) were given 30 min prior to ghrelin. Twelve or 24 hours after administration of ethanol, rats were anesthetized and experiments were terminated. The study revealed that administration of ethanol induced gastric ulcers in all animals and this effect was accompanied by the reduction in gastric blood flow and mucosal DNA synthesis. Moreover induction of gastric ulcer by ethanol significantly increased mucosal expression of mRNA for COX-2, IL-1β and TNF-α. Treatment with ghrelin significantly accelerated gastric ulcer healing. Therapeutic effect of ghrelin was associated with significant reversion of the ulcer-evoked decrease in mucosal blood flow and DNA synthesis. Ghrelin administration also caused the reduction in mucosal expression of mRNA for IL-1β and TNF-α. Addition of SC-560 slightly reduced the therapeutic effect of ghrelin in the healing of ethanol-induced ulcer and the ulcer area in rats treated SC-560 plus ghrelin was significantly smaller than that observed in rats treated with saline or SC-560 alone. Pretreatment with celecoxib, a COX-2 inhibitor, abolished therapeutic effect of ghrelin. We concluded that treatment with ghrelin increases healing rate of gastric ulcers evoked by ethanol and this effect is related to improvement in mucosal blood flow, an increase in mucosal cell

  12. Inhibiting an epoxide hydrolase virulence strategy protects CFTR**

    PubMed Central

    Bahl, Christopher D.; Hvorecny, Kelli L.; Bomberger, Jennifer M.; Stanton, Bruce A.; Hammock, Bruce D.; Morisseau, Christophe; Madden, Dean R.

    2015-01-01

    Opportunistic pathogens exploit diverse strategies to sabotage host defenses. Pseudomonas aeruginosa secretes the CFTR inhibitory factor Cif and thus triggers loss of CFTR, an ion channel required for airway mucociliary defense. However, Cif's mechanism of action has remained unclear. It catalyzes epoxide hydrolysis, but there is no known role for natural epoxides in CFTR regulation. Here, we show that Cif's hydrolase activity is strictly required for its effects on CFTR. We also uncover a small-molecule inhibitor that protects this key component of the mucociliary defense system. Our results provide a basis for targeting Cif's distinctive virulence chemistry and suggest an unanticipated role of physiological epoxides in intracellular protein trafficking. PMID:26136396

  13. Direct renin inhibition – a promising strategy for renal protection?

    PubMed Central

    Lizakowski, Sławomir; Tylicki, Leszek; Rutkowski, Bolesław

    2013-01-01

    Activation of the renin–angiotensin–aldosterone system (RAAS) plays a key role in the progression of chronic kidney disease (CKD). RAAS inhibitors, such as angiotensin converting enzyme inhibitors (ACEis) and angiotensin II receptor blockers (ARBs), decrease the rate of progression of diabetic and non-diabetic nephropathies and are first-line therapies for CKD. Although these agents are highly effective, current therapeutic strategies are unable to sufficiently suppress the RAAS and stop CKD progression. Aliskiren, the first in a new class of RAAS-inhibiting agents (direct renin inhibitors) has been approved to treat hypertension. Aliskiren exerts renoprotective, cardioprotective, and anti-atherosclerotic effects in animal models that appear to be independent of its blood pressure lowering activity. Early clinical studies using urinary protein excretion as a marker of renal involvement suggest a possibly novel role for aliskiren in treating CKD. This review discusses the antiproteinuric efficacy and safety of aliskiren and considers the evidence for its potential renoprotection. PMID:23756824

  14. Epidermal growth factor-induced cyclooxygenase-2 expression in oral squamous cell carcinoma cell lines is mediated through extracellular signal-regulated kinase 1/2 and p38 but is Src and nuclear factor-kappa B independent.

    PubMed

    Husvik, Camilla; Bryne, Magne; Halstensen, Trond S

    2009-10-01

    The intracellular signalling cascade(s) mediating epidermal growth factor (EGF)-induced cyclooxygenase-2 (COX-2) expression is poorly defined in oral carcinomas. Investigation of two different oral squamous cell carcinoma (OSCC) cell lines with high EGF-induced COX-2 expression revealed, however, that this expression was dependent on two mitogen-activated protein kinase (MAPK) pathways [extracellular signal-regulated kinase 1/2 (ERK1/2) and p38] because combined inhibition of these pathways was needed to abolish EGF-induced COX-2 expression. Surprisingly, inhibition of phosphoinositide-3 kinase (PI3K) increased EGF-induced COX-2 expression in the basaloid OSCC cell line (C12), suggesting a PI3K-controlled, inhibitory COX-2-regulating pathway. Neither the transcription factor nuclear factor-kappaB (NF-kappaB), nor Src, was involved in EGF-induced COX-2 expression. The results suggest that EGF-induced COX-2 expression is regulated by several pathways, and emphasizes that individual tumors use different strategies for intracellular signalling. PMID:19758248

  15. Suppression of cyclooxygenase-2 and inducible nitric oxide synthase expression by epimuqubilin A via IKK/IκB/NF-κB pathways in lipopolysaccharide-stimulated RAW 264.7 cells

    PubMed Central

    Park, Eun-Jung; Cheenpracha, Sarot; Chang, Leng Chee; Pezzuto, John M.

    2011-01-01

    Lipopolysaccharide (LPS)-stimulated RAW 264.7 cells are commonly used as a model for assessing the anti-inflammatory or chemopreventive potential of test compounds. Epimuqubilin A, a norsesterterpene peroxide isolated from marine sponge Latrunculia sp., inhibits nitric oxide production in LPS-stimulated RAW 264.7 cells (IC50 = 7.6 µM). At both the mRNA and protein levels, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) are suppressed in a dose-dependent manner. Mitogen-activated protein kinases (MAPKs), one major upstream signaling pathway involved in the transcription of both COX-2 and iNOS, were not affected by treatment of epimuqubilin A. However, the compound blocked the phosphorylation of inhibitor κB (IκB) kinase (IKKβ), resulting in the stabilization of IκBα, and inhibition of NF-κB p65 nuclear translocation and DNA binding. Levels of phosphorylated IKKα were not affected. This is an unique mechanistic relationship that suggests epimuqubilin A warrants further exploration as a potential therapeutic agent. PMID:22180763

  16. Radiation-enhancement of MDA-MB-231 breast cancer cell invasion prevented by a cyclooxygenase-2 inhibitor

    PubMed Central

    Paquette, B; Therriault, H; Desmarais, G; Wagner, R; Royer, R; Bujold, R

    2011-01-01

    Background: Recent evidences support that radiation can promote the invasion of cancer cells. As interactions between cancer cells and surrounding stromal cells can have an important role in tumour progression, we determined whether an irradiation to fibroblasts can enhance the invasiveness of breast cancer cells. The role of cyclooxygenase-2 (COX-2), an inflammatory enzyme frequently induced by radiotherapy, was investigated. Methods: Irradiated 3T3 fibroblasts were plated in the lower compartment of invasion chambers and used as chemoattractant for non-irradiated human breast cancer cell MDA-MB-231, which are oestrogen receptor negative (ER(−)) and the oestrogen receptor positive (ER(+)) MCF-7 cells. Stimulation of COX-2 expression in irradiated 3T3 cells was measured by a semi-quantitative qPCR and western blot. Capacity of the major product of COX-2, the prostaglandin E2 (PGE2), to stimulate the production of the matrix metalloproteinase-2 (MMP-2) and cancer cell invasion were assessed with a zymography gel and invasion chambers. Results: Irradiation (5 Gy) of 3T3 fibroblasts increased COX-2 expression and enhanced by 5.8-fold the invasiveness of non-irradiated MDA-MB-231 cells, while their migration was not modified. Addition of the COX-2 inhibitor NS-398 completely prevented radiation-enhancement of cancer cell invasion. Further supporting the potential role of COX-2, addition of PGE2 has increased cancer cell invasion and release of MMP-2 from the MDA-MB-231 cells. This effect of radiation was dependant on the expression of membrane type 1 (MT1)–MMP, which is required to activate the MMP-2, but was not associated with the ER status. Although irradiated fibroblasts stimulated the invasiveness of MDA-MB-231 ER(−) cells, no enhancement was measured with the ER(+) cell line MCF-7. Conclusions: Radiation-enhancement of breast cancer cell invasion induced by irradiated 3T3 fibroblasts is not dependant on the ER status, but rather the expression of MT1

  17. MAPK pathway activation by chronic lead-exposure increases vascular reactivity through oxidative stress/cyclooxygenase-2-dependent pathways

    SciTech Connect

    Simões, Maylla Ronacher; Aguado, Andrea; Fiorim, Jonaína; Silveira, Edna Aparecida; Azevedo, Bruna Fernandes; Toscano, Cindy Medice; Zhenyukh, Olha; Briones, Ana María; Alonso, María Jesús; Vassallo, Dalton Valentim; Salaices, Mercedes

    2015-03-01

    Chronic exposure to low lead concentration produces hypertension; however, the underlying mechanisms remain unclear. We analyzed the role of oxidative stress, cyclooxygenase-2-dependent pathways and MAPK in the vascular alterations induced by chronic lead exposure. Aortas from lead-treated Wistar rats (1st dose: 10 μg/100 g; subsequent doses: 0.125 μg/100 g, intramuscular, 30 days) and cultured aortic vascular smooth muscle cells (VSMCs) from Sprague Dawley rats stimulated with lead (20 μg/dL) were used. Lead blood levels of treated rats attained 21.7 ± 2.38 μg/dL. Lead exposure increased systolic blood pressure and aortic ring contractile response to phenylephrine, reduced acetylcholine-induced relaxation and did not affect sodium nitroprusside relaxation. Endothelium removal and L-NAME left-shifted the response to phenylephrine more in untreated than in lead-treated rats. Apocynin and indomethacin decreased more the response to phenylephrine in treated than in untreated rats. Aortic protein expression of gp91(phox), Cu/Zn-SOD, Mn-SOD and COX-2 increased after lead exposure. In cultured VSMCs lead 1) increased superoxide anion production, NADPH oxidase activity and gene and/or protein levels of NOX-1, NOX-4, Mn-SOD, EC-SOD and COX-2 and 2) activated ERK1/2 and p38 MAPK. Both antioxidants and COX-2 inhibitors normalized superoxide anion production, NADPH oxidase activity and mRNA levels of NOX-1, NOX-4 and COX-2. Blockade of the ERK1/2 and p38 signaling pathways abolished lead-induced NOX-1, NOX-4 and COX-2 expression. Results show that lead activation of the MAPK signaling pathways activates inflammatory proteins such as NADPH oxidase and COX-2, suggesting a reciprocal interplay and contribution to vascular dysfunction as an underlying mechanisms for lead-induced hypertension. - Highlights: • Lead-exposure increases oxidative stress, COX-2 expression and vascular reactivity. • Lead exposure activates MAPK signaling pathway. • ROS and COX-2 activation by

  18. Expression of integrin α3β1 and cyclooxygenase-2 (COX2) are positively correlated in human breast cancer

    PubMed Central

    2014-01-01

    Background Expression of integrin α3β1 is associated with tumor progression, metastasis, and poor prognosis in several cancers, including breast cancer. Moreover, preclinical studies have revealed important pro-tumorigenic and pro-metastatic functions for this integrin, including tumor growth, survival, invasion, and paracrine induction of angiogenesis. Our previously published work in a preclinical breast cancer model showed that integrin α3β1 promotes expression of cyclooxygenase-2 (COX2/PTGS2), a known driver of breast cancer progression. However, the clinical significance of this regulation was unknown. The objective of the current study was to assess the clinical relevance of the relationship between integrin α3β1 and COX2 by testing for their correlated expression among various forms of human breast cancer. Methods Immunohistochemistry was performed to assess co-expression of α3 and COX2 in specimens of human invasive ductal carcinoma (IDC), either on a commercial tissue microarray (n = 59 samples) or obtained from Albany Medical Center archives (n = 68 samples). Immunostaining intensity for the integrin α3 subunit or COX2 was scored, and Spearman’s rank correlation coefficient analysis was performed to assess their co-expression across and within different tumor subtypes or clinicopathologic criteria. Results Although expression of integrin α3 or COX2 varied among clinical IDC samples, a statistically significant, positive correlation was detected between α3 and COX2 in both tissue microarrays (rs = 0.49, p < 0.001, n = 59) and archived samples (rs = 0.59, p < 0.0001, n = 68). In both sample sets, this correlation was independent of hormone receptor status, histological grade, or disease stage. Conclusions COX2 and α3 are correlated in IDC independently of hormone receptor status or other clinicopathologic features, supporting the hypothesis that integrin α3β1 is a determinant of COX2 expression in human breast

  19. Altered mRNA editing and expression of ionotropic glutamate receptors after kainic acid exposure in cyclooxygenase-2 deficient mice.

    PubMed

    Caracciolo, Luca; Barbon, Alessandro; Palumbo, Sara; Mora, Cristina; Toscano, Christopher D; Bosetti, Francesca; Barlati, Sergio

    2011-01-01

    Kainic acid (KA) binds to the AMPA/KA receptors and induces seizures that result in inflammation, oxidative damage and neuronal death. We previously showed that cyclooxygenase-2 deficient (COX-2(-/-)) mice are more vulnerable to KA-induced excitotoxicity. Here, we investigated whether the increased susceptibility of COX-2(-/-) mice to KA is associated with altered mRNA expression and editing of glutamate receptors. The expression of AMPA GluR2, GluR3 and KA GluR6 was increased in vehicle-injected COX-2(-/-) mice compared to wild type (WT) mice in hippocampus and cortex, whereas gene expression of NMDA receptors was decreased. KA treatment decreased the expression of AMPA, KA and NMDA receptors in the hippocampus, with a significant effect in COX-2(-/-) mice. Furthermore, we analyzed RNA editing levels and found that the level of GluR3 R/G editing site was selectively increased in the hippocampus and decreased in the cortex in COX-2(-/-) compared with WT mice. After KA, GluR4 R/G editing site, flip form, was increased in the hippocampus of COX-2(-/-) mice. Treatment of WT mice with the COX-2 inhibitor celecoxib for two weeks decreased the expression of AMPA/KA and NMDAR subunits after KA, as observed in COX-2(-/-) mice. After KA exposure, COX-2(-/-) mice showed increased mRNA expression of markers of inflammation and oxidative stress, such as cytokines (TNF-α, IL-1β and IL-6), inducible nitric oxide synthase (iNOS), microglia (CD11b) and astrocyte (GFAP). Thus, COX-2 gene deletion can exacerbate the inflammatory response to KA. We suggest that COX-2 plays a role in attenuating glutamate excitotoxicity by modulating RNA editing of AMPA/KA and mRNA expression of all ionotropic glutamate receptor subunits and, in turn, neuronal excitability. These changes may contribute to the increased vulnerability of COX-2(-/-) mice to KA. The overstimulation of glutamate receptors as a consequence of COX-2 gene deletion suggests a functional coupling between COX-2 and the

  20. Polymorphisms in regulatory regions of Cyclooxygenase-2 gene and breast cancer risk in Brazilians: a case-control study

    PubMed Central

    2010-01-01

    Background Cyclooxygenase-2 (COX-2) is up-regulated in several types of cancer, and it is hypothesized that COX-2 expression may be genetically influenced. Here, we evaluate the association between single-nucleotide polymorphisms (SNPs) in the COX-2 gene (PTGS2) and the occurrence of breast cancer among Brazilian women. Methods The study was conducted prospectively in two steps: First, we screened the promoter region and three fragments of the 3'-untranslated region of PTGS2 from 67 healthy Brazilians to identify SNPs and to select those with a minor allele frequency (MAF) of at least 0.10. The MAF of these selected SNPs was further characterized in 402 healthy volunteers to evaluate potential differences related to heterogeneous racial admixture and to estimate the existence of linkage disequilibrium among the SNPs. The second step was a case-control study with 318 patients and 273 controls designed to evaluate PTGS2 genotype- or haplotype-associated risk of breast cancer. Results The screening analysis indicated nine SNPs with the following MAFs: rs689465 (0.22), rs689466 (0.15), rs20415 (0.007), rs20417 (0.32), rs20419 (0.015), rs5270 (0.02), rs20424 (0.007), rs5275 (0.22) and rs4648298 (0.01). The SNPs rs689465, rs689466, rs20417 and rs5275 were further studied: Their genotypic distributions followed Hardy-Weinberg equilibrium and the MAFs were not affected by gender or skin color. Strong linkage disequilibrium was detected for rs689465, rs20417 and rs5275 in the three possible pairwise combinations. In the case-control study, there was a significant increase of rs5275TC heterozygotes in cases compared to controls (OR = 1.44, 95% CI = 1.01-2.06; P = 0.043), and the haplotype formed by rs689465G, rs689466A, rs20417G and rs5275C was only detected in cases. The apparent association with breast cancer was not confirmed for rs5275CC homozygotes or for the most frequent rs5275C-containing haplotypes. Conclusions Our results indicate no strong association between the

  1. Ketamine Protects Gamma Oscillations by Inhibiting Hippocampal LTD

    PubMed Central

    Huang, Lanting; Yang, Xiu-Juan; Huang, Ying; Sun, Eve Y.

    2016-01-01

    NMDA receptors have been widely reported to be involved in the regulation of synaptic plasticity through effects on long-term potentiation (LTP) and long-term depression (LTD). LTP and LTD have been implicated in learning and memory processes. Besides synaptic plasticity, it is known that the phenomenon of gamma oscillations is critical in cognitive functions. Synaptic plasticity has been widely studied, however it is still not clear, to what degree synaptic plasticity regulates the oscillations of neuronal networks. Two NMDA receptor antagonists, ketamine and memantine, have been shown to regulate LTP and LTD, to promote cognitive functions, and have even been reported to bring therapeutic effects in major depression and Alzheimer’s disease respectively. These compounds allow us to investigate the putative interrelationship between network oscillations and synaptic plasticity and to learn more about the mechanisms of their therapeutic effects. In the present study, we have identified that ketamine and memantine could inhibit LTD, without impairing LTP in the CA1 region of mouse hippocampus, which may underlie the mechanism of these drugs’ therapeutic effects. Our results suggest that NMDA-induced LTD caused a marked loss in the gamma power, and pretreatment with 10 μM ketamine prevented the oscillatory loss via its inhibitory effect on LTD. Our study provides a new understanding of the role of NMDA receptors on hippocampal plasticity and oscillations. PMID:27467732

  2. Ketamine Protects Gamma Oscillations by Inhibiting Hippocampal LTD.

    PubMed

    Huang, Lanting; Yang, Xiu-Juan; Huang, Ying; Sun, Eve Y; Sun, Mu

    2016-01-01

    NMDA receptors have been widely reported to be involved in the regulation of synaptic plasticity through effects on long-term potentiation (LTP) and long-term depression (LTD). LTP and LTD have been implicated in learning and memory processes. Besides synaptic plasticity, it is known that the phenomenon of gamma oscillations is critical in cognitive functions. Synaptic plasticity has been widely studied, however it is still not clear, to what degree synaptic plasticity regulates the oscillations of neuronal networks. Two NMDA receptor antagonists, ketamine and memantine, have been shown to regulate LTP and LTD, to promote cognitive functions, and have even been reported to bring therapeutic effects in major depression and Alzheimer's disease respectively. These compounds allow us to investigate the putative interrelationship between network oscillations and synaptic plasticity and to learn more about the mechanisms of their therapeutic effects. In the present study, we have identified that ketamine and memantine could inhibit LTD, without impairing LTP in the CA1 region of mouse hippocampus, which may underlie the mechanism of these drugs' therapeutic effects. Our results suggest that NMDA-induced LTD caused a marked loss in the gamma power, and pretreatment with 10 μM ketamine prevented the oscillatory loss via its inhibitory effect on LTD. Our study provides a new understanding of the role of NMDA receptors on hippocampal plasticity and oscillations. PMID:27467732

  3. Wall teichoic acid protects Staphylococcus aureus from inhibition by Congo red and other dyes

    PubMed Central

    Suzuki, Takashi; Campbell, Jennifer; Kim, Younghoon; Swoboda, Jonathan G.; Mylonakis, Eleftherios; Walker, Suzanne; Gilmore, Michael S.

    2012-01-01

    Objectives Polyanionic polymers, including lipoteichoic acid and wall teichoic acid, are important determinants of the charged character of the staphylococcal cell wall. This study was designed to investigate the extent to which teichoic acid contributes to protection from anionic azo dyes and to identify barriers to drug penetration for development of new antibiotics for multidrug-resistant Staphylococcus aureus infection. Methods We studied antimicrobial activity of azo dyes against S. aureus strains with or without inhibition of teichoic acid in vitro and in vivo. Results We observed that inhibition of wall teichoic acid expression resulted in an ∼1000-fold increase in susceptibility to azo dyes such as Congo red, reducing its MIC from >1024 to <4 mg/L. Sensitization occurred when the first step in the wall teichoic acid pathway, catalysed by TarO, was inhibited either by mutation or by chemical inhibition. In contrast, genetic blockade of lipoteichoic acid biosynthesis did not confer Congo red susceptibility. Based on this finding, combination therapy was tested using the highly synergistic combination of Congo red plus tunicamycin at sub-MIC concentrations (to inhibit wall teichoic acid biosynthesis). The combination rescued Caenorhabditis elegans from a lethal challenge of S. aureus. Conclusions Our studies show that wall teichoic acid confers protection to S. aureus from anionic azo dyes and related compounds, and its inhibition raises the prospect of development of new combination therapies based on this inhibition. PMID:22615298

  4. HDAC Inhibition Elicits Myocardial Protective Effect through Modulation of MKK3/Akt-1

    PubMed Central

    Zhao, Ting C.; Du, Jianfeng; Zhuang, Shugang; Liu, Paul; Zhang, Ling X.

    2013-01-01

    We and others have demonstrated that HDAC inhibition protects the heart against myocardial injury. It is known that Akt-1 and MAP kinase play an essential role in modulation of myocardial protection and cardiac preconditioning. Our recent observations have shown that Akt-1 was activated in post-myocardial infarction following HDAC inhibition. However, it remains unknown whether MKK3 and Akt-1 are involved in HDAC inhibition-induced myocardial protection in acute myocardial ischemia and reperfusion injury. We sought to investigate whether the genetic disruption of Akt-1 and MKK3 eliminate cardioprotection elicited by HDAC inhibition and whether Akt-1 is associated with MKK3 to ultimately achieve protective effects. Adult wild type and MKK3−/−, Akt-1−/− mice received intraperitoneal injections of trichostatin A (0.1mg/kg), a potent inhibitor of HDACs. The hearts were subjected to 30 min myocardial ischemia/30 min reperfusion in the Langendorff perfused heart after twenty four hours to elicit pharmacologic preconditioning. Left ventricular function was measured, and infarct size was determined. Acetylation and phosphorylation of MKK3 were detected and disruption of Akt-1 abolished both acetylation and phosphorylation of MKK3. HDAC inhibition produces an improvement in left ventricular functional recovery, but these effects were abrogated by disruption of either Akt-1 or MKK3. Disruption of Akt-1 or MKK3 abolished the effects of HDAC inhibition-induced reduction of infarct size. Trichostatin A treatment resulted in an increase in MKK3 phosphorylation or acetylation in myocardium. Taken together, these results indicate that stimulation of the MKK3 and Akt-1 pathway is a novel approach to HDAC inhibition -induced cardioprotection. PMID:23762381

  5. The superoxide anion donor, potassium superoxide, induces pain and inflammation in mice through production of reactive oxygen species and cyclooxygenase-2.

    PubMed

    Maioli, N A; Zarpelon, A C; Mizokami, S S; Calixto-Campos, C; Guazelli, C F S; Hohmann, M S N; Pinho-Ribeiro, F A; Carvalho, T T; Manchope, M F; Ferraz, C R; Casagrande, R; Verri, W A

    2015-04-01

    It is currently accepted that superoxide anion (O2•-) is an important mediator in pain and inflammation. The role of superoxide anion in pain and inflammation has been mainly determined indirectly by modulating its production and inactivation. Direct evidence using potassium superoxide (KO2), a superoxide anion donor, demonstrated that it induced thermal hyperalgesia, as assessed by the Hargreaves method. However, it remains to be determined whether KO2 is capable of inducing other inflammatory and nociceptive responses attributed to superoxide anion. Therefore, in the present study, we investigated the nociceptive and inflammatory effects of KO2. The KO2-induced inflammatory responses evaluated in mice were: mechanical hyperalgesia (electronic version of von Frey filaments), thermal hyperalgesia (hot plate), edema (caliper rule), myeloperoxidase activity (colorimetric assay), overt pain-like behaviors (flinches, time spent licking and writhing score), leukocyte recruitment, oxidative stress, and cyclooxygenase-2 mRNA expression (quantitative PCR). Administration of KO2 induced mechanical hyperalgesia, thermal hyperalgesia, paw edema, leukocyte recruitment, the writhing response, paw flinching, and paw licking in a dose-dependent manner. KO2 also induced time-dependent cyclooxygenase-2 mRNA expression in the paw skin. The nociceptive, inflammatory, and oxidative stress components of KO2-induced responses were responsive to morphine (analgesic opioid), quercetin (antioxidant flavonoid), and/or celecoxib (anti-inflammatory cyclooxygenase-2 inhibitor) treatment. In conclusion, the well-established superoxide anion donor KO2 is a valuable tool for studying the mechanisms and pharmacological susceptibilities of superoxide anion-triggered nociceptive and inflammatory responses ranging from mechanical and thermal hyperalgesia to overt pain-like behaviors, edema, and leukocyte recruitment.

  6. The superoxide anion donor, potassium superoxide, induces pain and inflammation in mice through production of reactive oxygen species and cyclooxygenase-2

    PubMed Central

    Maioli, N.A.; Zarpelon, A.C.; Mizokami, S.S.; Calixto-Campos, C.; Guazelli, C.F.S.; Hohmann, M.S.N.; Pinho-Ribeiro, F.A.; Carvalho, T.T.; Manchope, M.F.; Ferraz, C.R.; Casagrande, R.; Verri, W.A.

    2015-01-01

    It is currently accepted that superoxide anion (O2 •−) is an important mediator in pain and inflammation. The role of superoxide anion in pain and inflammation has been mainly determined indirectly by modulating its production and inactivation. Direct evidence using potassium superoxide (KO2), a superoxide anion donor, demonstrated that it induced thermal hyperalgesia, as assessed by the Hargreaves method. However, it remains to be determined whether KO2 is capable of inducing other inflammatory and nociceptive responses attributed to superoxide anion. Therefore, in the present study, we investigated the nociceptive and inflammatory effects of KO2. The KO2-induced inflammatory responses evaluated in mice were: mechanical hyperalgesia (electronic version of von Frey filaments), thermal hyperalgesia (hot plate), edema (caliper rule), myeloperoxidase activity (colorimetric assay), overt pain-like behaviors (flinches, time spent licking and writhing score), leukocyte recruitment, oxidative stress, and cyclooxygenase-2 mRNA expression (quantitative PCR). Administration of KO2 induced mechanical hyperalgesia, thermal hyperalgesia, paw edema, leukocyte recruitment, the writhing response, paw flinching, and paw licking in a dose-dependent manner. KO2 also induced time-dependent cyclooxygenase-2 mRNA expression in the paw skin. The nociceptive, inflammatory, and oxidative stress components of KO2-induced responses were responsive to morphine (analgesic opioid), quercetin (antioxidant flavonoid), and/or celecoxib (anti-inflammatory cyclooxygenase-2 inhibitor) treatment. In conclusion, the well-established superoxide anion donor KO2 is a valuable tool for studying the mechanisms and pharmacological susceptibilities of superoxide anion-triggered nociceptive and inflammatory responses ranging from mechanical and thermal hyperalgesia to overt pain-like behaviors, edema, and leukocyte recruitment. PMID:25714890

  7. Relationship between epidermal growth factor receptor (EGFR) mutation and serum cyclooxygenase-2 Level, and the synergistic effect of celecoxib and gefitinib on EGFR expression in non-small cell lung cancer cells.

    PubMed

    Li, Na; Li, Huanhuan; Su, Fan; Li, Jing; Ma, Xiaoping; Gong, Ping

    2015-01-01

    Epidermal growth factor receptor (EGFR) mutations occur mostly in patients with lung adenocarcinoma; such patients are also more likely to express cyclooxygenase-2 (COX-2), indicating a possible relationship between EGFR mutation and COX-2. The COX-2 and EGFR pathways mutually enhance their procarcinogenic effects in different tumor types. Therefore, simultaneous EGFR and COX-2 inhibition may be a promising therapeutic approach for patients with lung adenocarcinoma. We obtained tissue and serum samples from patients with non-small cell lung cancer (NSCLC) to detect the relationship between EGFR mutation and serum COX-2 level. Subsequently, gefitinib was combined with celecoxib to investigate the efficacy of inhibition in vitro in two NSCLC cell lines: HCC827 (del E746-A750) and A549 (wild-type EGFR). The cells were treated with gefitinib or celecoxib alone or with gefitinib plus celecoxib. Cell proliferation and apoptosis were assessed and correlated with expression of COX-2 and phosphorylated (p)-EGFR. The EGFR mutation rate of the high-COX-2 patients was significantly higher than that in the low-COX-2 patients. Multivariate analysis showed that high COX-2 levels were independently associated with EGFR mutation. Celecoxib and gefitinib inhibited cell growth in both cell lines. At sufficiently high concentrations, celecoxib plus gefitinib significantly mutually enhanced their anti-proliferative and apoptotic effects in both cell lines. At low concentrations, the combination had no additional effects on A549 cells. There was increased down regulation of COX-2 and p-EGFR when both cell lines were treated with high-concentration celecoxib plus gefitinib compared to either agent alone. This study demonstrates that high serum COX-2 levels may indicate EGFR mutations and that the efficacy of combined celecoxib and gefitinib is significantly greater in NSCLC cells with EGFR mutations; at high concentrations, the combination is efficacious in wild-type NSCLC cells.

  8. Alpha-lipoic acid protects cardiomyocytes against hypoxia/reoxygenation injury by inhibiting autophagy

    SciTech Connect

    Cao, Xueming; Chen, Aihua Yang, Pingzhen; Song, Xudong; Liu, Yingfeng; Li, Zhiliang; Wang, Xianbao; Wang, Lizi; Li, Yunpeng

    2013-11-29

    Highlights: •We observed the cell viability and death subjected to H/R in H9c2 cardiomyocytes. •We observed the degree of autophagy subjected to H/R in H9c2 cardiomyocytes. •LA inhibited the degree of autophagy in parallel to the enhanced cell survival. •LA inhibited the autophagy in parallel to the decreased total cell death. •We concluded that LA protected cardiomyocytes against H/R by inhibiting autophagy. -- Abstract: Hypoxia/reoxygenation (H/R) is an important in vitro model for exploring the molecular mechanisms and functions of autophagy during myocardial ischemia/reperfusion (I/R). Alpha-lipoic acid (LA) plays an important role in the etiology of cardiovascular disease. Autophagy is widely implicated in myocardial I/R injury. We assessed the degree of autophagy by pretreatment with LA exposed to H/R in H9c2 cell based on the expression levels of Beclin-1, LC3II/LC3I, and green fluorescent protein-labeled LC3 fusion proteins. Autophagic vacuoles were confirmed in H9c2 cells exposed to H/R using transmission electron microscopy. Our findings indicated that pretreatment with LA inhibited the degree of autophagy in parallel to the enhanced cell survival and decreased total cell death in H9c2 cells exposed to H/R. We conclude that LA protects cardiomyocytes against H/R injury by inhibiting autophagy.

  9. Sphingosine-1-phosphate protects endothelial glycocalyx by inhibiting syndecan-1 shedding.

    PubMed

    Zeng, Ye; Adamson, Roger H; Curry, Fitz-Roy E; Tarbell, John M

    2014-02-01

    Endothelial cells (ECs) are covered by a surface glycocalyx layer that forms part of the barrier and mechanosensing functions of the blood-tissue interface. Removal of albumin in bathing media induces collapse or shedding of the glycocalyx. The electrostatic interaction between arginine residues on albumin, and negatively charged glycosaminoglycans (GAGs) in the glycocalyx have been hypothesized to stabilize the glycocalyx structure. Because albumin is one of the primary carriers of the phospholipid sphingosine-1-phosphate (S1P), we evaluated the alternate hypothesis that S1P, acting via S1P1 receptors, plays the primary role in stabilizing the endothelial glycocalyx. Using confocal microscopy on rat fat-pad ECs, we demonstrated that heparan sulfate (HS), chondroitin sulfate (CS), and ectodomain of syndecan-1 were shed from the endothelial cell surface after removal of plasma protein but were retained in the presence of S1P at concentrations of >100 nM. S1P1 receptor antagonism abolished the protection of the glycocalyx by S1P and plasma proteins. S1P reduced GAGs released after removal of plasma protein. The mechanism of protection from loss of glycocalyx components by S1P-dependent pathways was shown to be suppression of metalloproteinase (MMP) activity. General inhibition of MMPs protected against loss of CS and syndecan-1. Specific inhibition of MMP-9 and MMP-13 protected against CS loss. We conclude that S1P plays a critical role in protecting the glycocalyx via S1P1 and inhibits the protease activity-dependent shedding of CS, HS, and the syndecan-1 ectodomain. Our results provide new insight into the role for S1P in protecting the glycocalyx and maintaining vascular homeostasis.

  10. Safrole oxide induces human umbilical vein endothelial cell transdifferentiation to 5-hydroxytryptaminergic neuron-like cells through tropomyosin receptor kinase A/cyclooxygenase 2/nuclear factor-kappa B/interleukin 8 signaling.

    PubMed

    Su, Le; Zhao, Jing; Zhao, Bao Xiang; Zhang, Shang Li; Miao, Jun Ying

    2011-10-01

    The phenomenon of endothelial-neural transdifferentiation has been observed for a long time, but the mechanism is not clear. We previously found that safrole oxide induced human umbilical vein endothelial cell transdifferentiation into neuron-like cells. In this study, we first validated that these cells induced by safrole oxide were functional 5-hydroxytryptaminergic neuron-like cells. Then, we performed microarray analysis of safrole oxide-treated and -untreated human umbilical vein endothelial cells. Safrole oxide elevated the levels of cyclooxygenase 2 (COX-2), interleukin-8 (IL-8) and reactive oxygen species (ROS), which was accompanied by nuclear factor-kappa B (NF-κB) nuclear translocation during the transdifferentiation. Blockade of tropomyosin receptor kinase A (TrkA) by an inhibitor or short hairpin RNA inhibited the levels of COX-2/IL-8 and the nuclear translocation of NF-κB but did not suppress the increased ROS level. As a result, cells underwent apoptosis. Therefore, via TrkA, safrole oxide may induce endothelial cell transdifferentiation into functional neuron-like cells. During this process, the increased levels of COX-2/IL-8 and the subsequent elevation of ROS production induced NF-κB nuclear translocation and IL-8 secretion. With the activity of TrkA inhibited, the inactive NF-κB regulated the ROS level in a negative feedback manner. Finally, the transdifferentiation pathway was blocked and cells became apoptotic. The TrkA/COX-2/IL-8 signal pathway may have an important role in endothelial-neural transdifferentiation, and safrole oxide may trigger this process by activating TrkA.

  11. Topoisomerase 1 inhibition suppresses inflammatory genes and protects from death by inflammation.

    PubMed

    Rialdi, Alex; Campisi, Laura; Zhao, Nan; Lagda, Arvin Cesar; Pietzsch, Colette; Ho, Jessica Sook Yuin; Martinez-Gil, Luis; Fenouil, Romain; Chen, Xiaoting; Edwards, Megan; Metreveli, Giorgi; Jordan, Stefan; Peralta, Zuleyma; Munoz-Fontela, Cesar; Bouvier, Nicole; Merad, Miriam; Jin, Jian; Weirauch, Matthew; Heinz, Sven; Benner, Chris; van Bakel, Harm; Basler, Christopher; García-Sastre, Adolfo; Bukreyev, Alexander; Marazzi, Ivan

    2016-05-27

    The host innate immune response is the first line of defense against pathogens and is orchestrated by the concerted expression of genes induced by microbial stimuli. Deregulated expression of these genes is linked to the initiation and progression of diseases associated with exacerbated inflammation. We identified topoisomerase 1 (Top1) as a positive regulator of RNA polymerase II transcriptional activity at pathogen-induced genes. Depletion or chemical inhibition of Top1 suppresses the host response against influenza and Ebola viruses as well as bacterial products. Therapeutic pharmacological inhibition of Top1 protected mice from death in experimental models of lethal inflammation. Our results indicate that Top1 inhibition could be used as therapy against life-threatening infections characterized by an acutely exacerbated immune response. PMID:27127234

  12. N-n-butyl haloperidol iodide protects cardiomyocytes against hypoxia/reoxygenation injury by inhibiting autophagy.

    PubMed

    Wang, Bin; Zhong, Shuping; Zheng, Fuchun; Zhang, Yanmei; Gao, Fenfei; Chen, Yicun; Lu, Binger; Xu, Han; Shi, Ganggang

    2015-09-22

    N-n-butyl haloperidol iodide (F2), a novel compound derived from haloperidol, protects against the damaging effects of ischemia/reperfusion (I/R) injury in vitro and in vivo. In this study, we hypothesized the myocardial protection of F2 on cardiomyocyte hypoxia/reoxygenation (H/R) injury is mediated by inhibiting autophagy in H9c2 cells. The degree of autophagy by treatment with F2 exposed to H/R in H9c2 cell was characterized by monodansylcadaverine, transmission electron microscopy, and expression of autophagy marker protein LC3. Our results indicated that treatment with F2 inhibited autophagy in H9c2 cells exposed to H/R. 3-methyladenine, an inhibitor of autophagy, suppressed H/R-induced autophagy, and decreased apoptosis, whereas rapamycin, a classical autophagy sensitizer, increased autophagy and apoptosis. Mechanistically, macrophage migration inhibitory factor (MIF) was inhibited by F2 treatment after H/R. Accordingly, small interfering RNA (siRNA)-mediated MIF knockdown decreased H/R-induced autophagy. In summary, F2 protects cardiomyocytes during H/R injury through suppressing autophagy activation. Our results provide a new mechanistic insight into a functional role of F2 against H/R-induced cardiomyocyte injury and death.

  13. Inhibition of mitochondrial calcium uniporter protects neurocytes from ischemia/reperfusion injury via the inhibition of excessive mitophagy.

    PubMed

    Yu, Shoushui; Zheng, Shengfa; Leng, Jing; Wang, Shilei; Zhao, Tao; Liu, Jia

    2016-08-15

    Mitophagy plays an important role in mitochondrial quality control and cell survival during the process of ischemia/reperfusion (I/R) injury. Mitochondrial calcium uniporter (MCU) is the most important channel responsible for Ca(2+) influx into mitochondria and Ca(2+) signal plays a potential role in modulating mitophagy. However, the effect of MCU on mitophagy during the process of I/R injury remains unknown. This study constructed an in vitro I/R model by subjecting oxygen and glucose deprivation/reperfusion (OGD/RP) model to SH-SY5Y cells to mimic the cerebral I/R injury and aimed to explore the exact effect of MCU on I/R induced mitophagy. The results showed that OGD/RP induced autophagy and mitophagy in SH-SY5Y cells. Ru360, the inhibitor of MCU, improved mitochondrial morphology and fuctional stability as well as cell viability, significantly reduced OGD/RP induced mitophagy as evidenced by the decrease in Beclin-1 and the increase in Tom20 and P62 expression. Whereas spermine, the agonist of MCU, had no significant impact on the expression of those mitophagy related proteins compared with OGD/RP group. This study indicates that inhibition of MCU can inhibit excessive mitophagy and protect the neurocytes from I/R injury.

  14. Meloxicam, an inhibitor of cyclooxygenase-2, increases the level of serum G-CSF and might be usable as an auxiliary means in G-CSF therapy.

    PubMed

    Hofer, M; Pospísil, M; Znojil, V; Holá, J; Vacek, A; Streitová, D

    2008-01-01

    Hematopoiesis-modulating action of meloxicam, a cyclooxyge-nase-2 inhibitor, has been evaluated in mice. Increased serum level of granulocyte colony-stimulating factor (G-CSF) after meloxicam administration has been found in sublethally gamma-irradiated animals. In further experiments hematopoiesis-stimulating effects of meloxicam and G-CSF given alone or in combination have been investigated. Granulocyte/macrophage progenitor cells counts were used to monitor these effects. Meloxicam and exogenous G-CSF did not act synergistically when given in combination, but could be mutually substituted during their repeated administration. The results suggest a promising possibility of using meloxicam as an auxiliary drug reducing the high costs of G-CSF therapy of myelosuppression.

  15. DNA Sequence Variants in the Five Prime Untranslated Region of the Cyclooxygenase-2 Gene Are Commonly Found in Healthy Dogs and Gray Wolves.

    PubMed

    Safra, Noa; Hayward, Louisa J; Aguilar, Miriam; Sacks, Benjamin N; Westropp, Jodi L; Mohr, F Charles; Mellersh, Cathryn S; Bannasch, Danika L

    2015-01-01

    The aim of this study was to investigate the frequency of regional DNA variants upstream to the translation initiation site of the canine Cyclooxygenase-2 (Cox-2) gene in healthy dogs. Cox-2 plays a role in various disease conditions such as acute and chronic inflammation, osteoarthritis and malignancy. A role for Cox-2 DNA variants in genetic predisposition to canine renal dysplasia has been proposed and dog breeders have been encouraged to select against these DNA variants. We sequenced 272-422 bases in 152 dogs unaffected by renal dysplasia and found 19 different haplotypes including 11 genetic variants which had not been described previously. We genotyped 7 gray wolves to ascertain the wildtype variant and found that the wolves we analyzed had predominantly the second most common DNA variant found in dogs. Our results demonstrate an elevated level of regional polymorphism that appears to be a feature of healthy domesticated dogs.

  16. Bisphenol A-induced epithelial to mesenchymal transition is mediated by cyclooxygenase-2 up-regulation in human endometrial carcinoma cells.

    PubMed

    Wang, Kai-Hung; Kao, An-Pei; Chang, Chia-Cheng; Lin, Ta-Chin; Kuo, Tsung-Cheng

    2015-12-01

    Many studies have highlighted the correlation between the increase of bisphenol A (BPA) level in the environment and the incidence of tumor in humans. In human carcinogenesis, the overexpression of cyclooxygenase-2 (COX-2) and epithelial-mesenchymal transition (EMT) are closely related with tumor development. In this study, human endometrial carcinoma cells line (RL95-2) was used to investigate whether BPA can induce EMT and COX-2 expression. The results show that BPA increased growth rate and colony-forming efficiency in a dose-dependent manner, induced EMT and COX-2 gene expression and promoted the migration and invasion ability of RL95-2 cells. Furthermore, our study showed that the expression of COX-2 was essential for BPA-induced cell migration and invasion. The results of this study provide new insights into the mechanism of endometrial cancer cell growth and invasion and potential therapeutic strategy. PMID:26546977

  17. Cyclooxygenase-2 expression is related to nuclear grade in ductal carcinoma in situ and is increased in its normal adjacent epithelium

    NASA Technical Reports Server (NTRS)

    Shim, Veronica; Gauthier, Mona L.; Sudilovsky, Daniel; Mantei, Kristin; Chew, Karen L.; Moore, Dan H.; Cha, Imok; Tlsty, Thea D.; Esserman, Laura J.

    2003-01-01

    Cyclooxygenase-2 (COX-2) is emerging as an important cancer biomarker and is now an experimental target for solid tumor treatment.However, no study has exclusively focused on COX-2 expression in early lesions such as ductal carcinoma in situ (DCIS). We examined COX-2 expression by immunohistochemistry in 46 cases of women undergoing surgical resection for DCIS. We found that COX-2 expression was detected in 85% of all DCIS specimens, with increased COX-2 staining correlating with higher nuclear grade. Strikingly, COX-2 staining intensity in the normal adjacent epithelium was stronger than in the DCIS lesion itself. Our observations demonstrate that COX-2 is up-regulated in the normal adjacent epithelium and supports the hypothesis that the surrounding epithelial tissue is part of the disease process in DCIS.

  18. DNA Sequence Variants in the Five Prime Untranslated Region of the Cyclooxygenase-2 Gene Are Commonly Found in Healthy Dogs and Gray Wolves

    PubMed Central

    Safra, Noa; Hayward, Louisa J.; Aguilar, Miriam; Sacks, Benjamin N.; Westropp, Jodi L.; Mohr, F. Charles; Mellersh, Cathryn S.; Bannasch, Danika L.

    2015-01-01

    The aim of this study was to investigate the frequency of regional DNA variants upstream to the translation initiation site of the canine Cyclooxygenase-2 (Cox-2) gene in healthy dogs. Cox-2 plays a role in various disease conditions such as acute and chronic inflammation, osteoarthritis and malignancy. A role for Cox-2 DNA variants in genetic predisposition to canine renal dysplasia has been proposed and dog breeders have been encouraged to select against these DNA variants. We sequenced 272–422 bases in 152 dogs unaffected by renal dysplasia and found 19 different haplotypes including 11 genetic variants which had not been described previously. We genotyped 7 gray wolves to ascertain the wildtype variant and found that the wolves we analyzed had predominantly the second most common DNA variant found in dogs. Our results demonstrate an elevated level of regional polymorphism that appears to be a feature of healthy domesticated dogs. PMID:26244515

  19. Nuclear factor-kappaB (NF-kappaB) and cyclooxygenase-2 (COX-2) expression in the oral mucosa following cancer chemotherapy.

    PubMed

    Logan, Richard M; Gibson, Rachel J; Sonis, Stephen T; Keefe, Dorothy M K

    2007-04-01

    Oral mucositis is a serious and debilitating side effect of cancer treatment. Greater understanding of the pathobiology of mucositis has recently led to the advent of targeted treatments for specific patient populations; however the treatment for mucositis remains palliative for most patients. Nuclear factor-kappaB (NF-kappaB) and cyclooxygenase 2 (COX-2) are thought to play important roles in the development of mucositis. In this study, 20 patients undergoing cytotoxic chemotherapy had oral mucosal biopsies taken prior to and following administration of cytotoxic chemotherapy. The samples were stained for NF-kappaB and COX-2 using routine immunohistochemistry. The results from this preliminary study demonstrated statistically significant increased oral mucosal staining for NF-kappaB and COX-2 following cytotoxic chemotherapy and provide further support for the role of NF-kappaB and COX-2 in the pathogenesis of mucositis. PMID:16979925

  20. Spontaneous adenocarcinoma immunoreactive to cyclooxygenase-2 and transforming growth factor-beta1 in the buccal salivary gland of a Richardson's ground squirrel (Spermophilus richardsonii).

    PubMed

    Yamate, Jyoji; Yamamoto, Emi; Nabe, Mikoto; Kuwamura, Mitsuru; Fujita, Daisuke; Sasai, Hiroshi

    2007-10-01

    The ground squirrel is used as an experimental animal because of its unique biological nature. A 3-year-old female Richardson's ground squirrel developed a mass, 1.5 cm in diameter, in the buccal mucosa. The mass consisted of neoplastic epithelial cells showing acinar, ductular, intraductal papillary, solid, and lobular growth patterns; the cells were immunoreactive to cytokeratin, cyclooxygenase-2 (a marker of malignancy) and TGF-beta1. After resection, the tumor recurred with increased area having a solid or lobular pattern with little differentiation. This tumor was diagnosed as an adenocarcinoma arising from the buccal gland, the first case reported in the ground squirrel. A prominent desmoplastic reaction was present. The interstitial cells reacted to alpha-smooth muscle actin and vimentin, indicating a myofibroblastic nature, presumably induced by epithelial TGF-beta1.

  1. Puerarin protects against CCl4-induced liver fibrosis in mice: possible role of PARP-1 inhibition.

    PubMed

    Wang, Shuai; Shi, Xiao-Lei; Feng, Min; Wang, Xun; Zhang, Zhi-Heng; Zhao, Xin; Han, Bing; Ma, Hu-Cheng; Dai, Bo; Ding, Yi-Tao

    2016-09-01

    Liver fibrosis, which is the pathophysiologic process of the liver due to sustained wound healing in response to chronic liver injury, will eventually progress to cirrhosis. Puerarin, a bioactive isoflavone glucoside derived from the traditional Chinese medicine pueraria, has been reported to have many anti-inflammatory and anti-fibrosis properties. However, the detailed mechanisms are not well studied yet. This study aimed to investigate the effects of puerarin on liver function and fibrosis process in mice induced by CCl4. C57BL/6J mice were intraperitoneally injected with 10% CCl4 in olive oil(2mL/kg) with or without puerarin co-administration (100 and 200mg/kg intraperitoneally once daily) for four consecutive weeks. As indicated by the ameliorative serum hepatic enzymes and the reduced histopathologic abnormalities, the data collected showed that puerarin can protect against CCl4-induced chronic liver injury. Moreover, CCl4-induced development of fibrosis, as evidenced by increasing expression of alpha smooth muscle actin(α-SMA), collagen-1, transforming growth factor (TGF)-β and connective tissue growth factor(CTGF) in liver, were suppressed by puerarin. Possible mechanisms related to these suppressive effects were realized by inhibition on NF-κB signaling pathway, reactive oxygen species(ROS) production and mitochondrial dysfunction in vivo. In addition, these protective inhibition mentioned above were driven by down-regulation of PARP-1 due to puerarin because puerarin can attenuate the PARP-1 expression in CCl4-damaged liver and PJ34, a kind of PARP-1 inhibitor, mimicked puerarin's protection. In conclusion, puerarin played a protective role in CCl4-induced liver fibrosis probably through inhibition of PARP-1 and subsequent attenuation of NF-κB, ROS production and mitochondrial dysfunction. PMID:27318789

  2. Pioglitazone Protected against Cardiac Hypertrophy via Inhibiting AKT/GSK3β and MAPK Signaling Pathways

    PubMed Central

    Wei, Wen-Ying; Ma, Zhen-Guo; Xu, Si-Chi; Zhang, Ning; Tang, Qi-Zhu

    2016-01-01

    Peroxisome proliferator activated receptor γ (PPARγ) has been closely involved in the process of cardiovascular diseases. This study was to investigate whether pioglitazone (PIO), a PPARγ agonist, could protect against pressure overload-induced cardiac hypertrophy. Mice were orally given PIO (2.5 mg/kg) from 1 week after aortic banding and continuing for 7 weeks. The morphological examination and biochemical analysis were used to evaluate the effects of PIO. Neonatal rat ventricular cardiomyocytes were also used to verify the protection of PIO against hypertrophy in vitro. The results in our study demonstrated that PIO remarkably inhibited hypertrophic response induced by aortic banding in vivo. Besides, PIO also suppressed cardiac fibrosis in vivo. PIO treatment also inhibited the activation of protein kinase B (AKT)/glycogen synthase kinase-3β (GSK3β) and mitogen-activated protein kinase (MAPK) in the heart. In addition, PIO alleviated angiotensin II-induced hypertrophic response in vitro. In conclusion, PIO could inhibit cardiac hypertrophy via attenuation of AKT/GSK3β and MAPK pathways. PMID:27110236

  3. Astrocyte-Specific Overexpression of Nrf2 Protects Striatal Neurons from Mitochondrial Complex II Inhibition

    PubMed Central

    Calkins, Marcus J.; Vargas, Marcelo R.; Johnson, Delinda A.; Johnson, Jeffrey A.

    2010-01-01

    Nuclear factor E2-related factor 2 (Nrf2) is a transcription factor that is known to regulate a variety of cytoprotective genes through the antioxidant response element (ARE). This endogenous response is one of the major pathways by which cells are protected from xenobiotic or innate oxidative insults. Furthermore, in neural systems, astrocyte-specific activation of Nrf2 is known to protect neurons. In previous work, our laboratory found that Nrf2 protects from intrastriatal injections of the mitochondrial complex II inhibitor malonate. Here, we extend these results to show that multiple methods of astrocyte-specific Nrf2 overexpression provide protection from neurotoxicity in vivo. GFAP-Nrf2 transgenic mice are significantly more resistant to malonate lesioning. This outcome is associated with an increased basal resistance, but more so, an enhanced Nrf2 response to lesioning that attenuated the ensuing neurotoxicity. Furthermore, striatal transplantation of neuroprogenitor cells overexpressing Nrf2 that differentiate into astrocytes after grafting also significantly reduced malonate toxicity. Overall, these data establish that enhanced astrocytic Nrf2 response and Nrf2 preconditioning are both sufficient to protect from acute lesions from mitochondrial complex II inhibition. PMID:20211941

  4. Actin and DNA Protect Histones from Degradation by Bacterial Proteases but Inhibit Their Antimicrobial Activity

    PubMed Central

    Sol, Asaf; Skvirsky, Yaniv; Blotnick, Edna; Bachrach, Gilad; Muhlrad, Andras

    2016-01-01

    Histones are small polycationic proteins located in the cell nucleus. Together, DNA and histones are integral constituents of the nucleosomes. Upon apoptosis, necrosis, and infection – induced cell death, histones are released from the cell. The extracellular histones have strong antimicrobial activity but are also cytotoxic and thought as mediators of cell death in sepsis. The antimicrobial activity of the cationic extracellular histones is inhibited by the polyanionic DNA and F-actin, which also become extracellular upon cell death. DNA and F-actin protect histones from degradation by the proteases of Pseudomonas aeruginosa and Porphyromonas gingivalis. However, though the integrity of the histones is protected, the activity of histones as antibacterial agents is lost. The inhibition of the histone’s antibacterial activity and their protection from proteolysis by DNA and F-actin indicate a tight electrostatic interaction between the positively charged histones and negatively charged DNA and F-actin, which may have physiological significance in maintaining the equilibrium between the beneficial antimicrobial activity of extracellular histones and their cytotoxic effects. PMID:27555840

  5. Actin and DNA Protect Histones from Degradation by Bacterial Proteases but Inhibit Their Antimicrobial Activity.

    PubMed

    Sol, Asaf; Skvirsky, Yaniv; Blotnick, Edna; Bachrach, Gilad; Muhlrad, Andras

    2016-01-01

    Histones are small polycationic proteins located in the cell nucleus. Together, DNA and histones are integral constituents of the nucleosomes. Upon apoptosis, necrosis, and infection - induced cell death, histones are released from the cell. The extracellular histones have strong antimicrobial activity but are also cytotoxic and thought as mediators of cell death in sepsis. The antimicrobial activity of the cationic extracellular histones is inhibited by the polyanionic DNA and F-actin, which also become extracellular upon cell death. DNA and F-actin protect histones from degradation by the proteases of Pseudomonas aeruginosa and Porphyromonas gingivalis. However, though the integrity of the histones is protected, the activity of histones as antibacterial agents is lost. The inhibition of the histone's antibacterial activity and their protection from proteolysis by DNA and F-actin indicate a tight electrostatic interaction between the positively charged histones and negatively charged DNA and F-actin, which may have physiological significance in maintaining the equilibrium between the beneficial antimicrobial activity of extracellular histones and their cytotoxic effects. PMID:27555840

  6. Corosolic acid inhibits the proliferation of glomerular mesangial cells and protects against diabetic renal damage

    PubMed Central

    Li, Xiao-Qiang; Tian, Wen; Liu, Xiao-Xiao; Zhang, Kai; Huo, Jun-Cheng; Liu, Wen-Juan; Li, Ping; Xiao, Xiong; Zhao, Ming-Gao; Cao, Wei

    2016-01-01

    Diabetic nephropathy (DN) is one of the major complications of diabetes mellitus (DM). This study aimed to explore the effects of corosolic acid (CA) on the renal damage of DM and the mechanisms behind these effects. The renoprotective effect of CA was investigated in type 1 diabetic rats and db/db mice. The kidneys and glomerular mesangial cells (GMCs) were used to study the proliferation of GMCs by immunostaining and MTT assay. Further immunoblotting, siRNA, qPCR analysis, and detecting of NADPH oxidase activity and reactive oxygen species (ROS) generation were performed to explore relevant molecular mechanisms. In CA-treated diabetic animals, diabetes-induced albuminuria, increased serum creatinine and blood urea nitrogen were significantly attenuated, and glomerular hypertrophy, mesangial expansion and fibrosis were ameliorated. Furthermore, CA significantly inhibited proliferation of GMCs and phosphorylation of ERK1/2 and p38 MAPK in both diabetic animals and high glucose (HG)-induced GMCs. CA also normalized Δψm and inhibited HG-induced NADPH oxidase activity, ROS generation and NOX4, NOX2, p22phox and p47phox expression. More importantly, CA inhibited GMC proliferation mediated by NADPH/ERK1/2 and p38 MAPK signaling pathways. These findings suggest that CA exert the protective effect on DN by anti-proliferation resulted from inhibition of p38 MAPK- and NADPH-mediated inactivation of ERK1/2. PMID:27229751

  7. Involvement of reactive oxygen intermediates in cyclooxygenase-2 expression induced by interleukin-1, tumor necrosis factor-alpha, and lipopolysaccharide.

    PubMed Central

    Feng, L; Xia, Y; Garcia, G E; Hwang, D; Wilson, C B

    1995-01-01

    Reactive oxygen intermediates (ROIs) play an important role in inflammatory processes as mediators of injury and potentially in signal transduction leading to gene expression. Cyclooxygenase (COX) is a rate-limiting enzyme in prostanoid biosynthesis, and its recently cloned inducible form, COX-2, is induced by proinflammatory cytokines. This study linked ROIs to the signaling pathways that induce COX-2 expression. The hydroxyl radical scavengers DMSO (1%), as well as di- and tetramethylthiourea, inhibited IL-1-, TNF alpha-, and LPS-induced COX-2 expression in rat mesangial cells. The suppression of COX-2 mRNA expression correlated with the COX-2 protein level. In comparison with the prolonged induction of the inducible gene encoding protein-tyrosine phosphatase by hydrogen peroxide, the COX-2 gene was only transiently induced. Protein-tyrosine phosphatase is also induced by heat shock and chemical stress, whereas COX-2 is not. Superoxide was a more potent inducer for COX-2 than hydrogen peroxide. In addition, NADPH stimulated COX-2 expression, and an inhibitor of NADPH oxidase blocked COX-2 expression induced by TNF alpha. COX-2 and KC gene expression costimulated by IL-1 were inhibited differentially by the scavengers. These studies demonstrate that oxidant stress is a specific and important inducer of COX-2 gene expression. This induction may contribute to the deleterious amplification of prostanoids in inflammation and compound the direct effects of ROI production. Images PMID:7706475

  8. Inhibitory effect of etodolac, a selective cyclooxygenase-2 inhibitor, on stomach carcinogenesis in Helicobacter pylori-infected Mongolian gerbils

    SciTech Connect

    Magari, Hirohito; Shimizu, Yasuhito; Inada, Ken-ichi; Enomoto, Shotaro; Tomeki, Tatsuji; Yanaoka, Kimihiko; Tamai, Hideyuki; Arii, Kenji; Nakata, Hiroya; Oka, Masashi; Utsunomiya, Hirotoshi; Tsutsumi, Yutaka; Tsukamoto, Tetsuya; Tatematsu, Masae; Ichinose, Masao E-mail: ichinose@wakayama-med.ac.jp

    2005-08-26

    The effect of the selective COX-2 inhibitor, etodolac, on Helicobacter pylori (Hp)-associated stomach carcinogenesis was investigated in Mongolian gerbils (MGs). Hp-infected MGs were fed for 23 weeks with drinking water containing 10 ppm N-methyl-N-nitrosourea. They were then switched to distilled water and placed on a diet containing 5-30 mg/kg/day etodolac for 30 weeks. We found that etodolac dose-dependently inhibited the development of gastric cancer, and no cancer was detected at a dose of 30 mg/kg/day. Etodolac did not affect the extent of inflammatory cell infiltration or oxidative DNA damage, but it significantly inhibited mucosal cell proliferation and dose-dependently repressed the development of intestinal metaplasia in the stomachs of Hp-infected MGs. These results suggest that COX-2 is a key molecule in inflammation-mediated stomach carcinogenesis and that chemoprevention of stomach cancer should be possible by controlling COX-2 expression or activity.

  9. Activated hepatic stellate cells promote liver cancer by induction of myeloid-derived suppressor cells through cyclooxygenase-2

    PubMed Central

    Xu, Jianfeng; Li, Jie; Hong, Zaifa; Yin, Zhenyu; Wang, Xiaomin

    2016-01-01

    Hepatic stellate cells (HSCs) are critical mediators of immunosuppression and the pathogenesis of hepatocellular carcinoma (HCC). Our previous work indicates that HSCs promote HCC progression by enhancing immunosuppressive cell populations including myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs). MDSCs are induced by inflammatory cytokines (e.g., prostaglandins) and are important in immune suppression. However, how HSCs mediate expansion of MDSCs is uncertain. Thus, we studied activated HSCs that could induce MDSCs from bone marrow cells and noted that HSC-induced MDSCs up-regulated immunosuppressive activity via iNOS, Arg-1, and IL-4Rα. After treating cells with a COX-2 inhibitor or an EP4 antagonist, we established that HSC-induced MDSC accumulation was mediated by the COX2-PGE2-EP4 signaling. Furthermore, in vivo animal studies confirmed that inhibition of HSC-derived PGE2 could inhibit HSC-induced MDSC accumulation and HCC growth. Thus, our data show that HSCs are required for MDSC accumulation mediated by the COX2-PGE2-EP4 pathway, and these data are the first to link HSC and MDSC subsets in HCC immune microenvironment and provide a rationale for targeting PGE2 signaling for HCC therapy. PMID:26758420

  10. Key role for constitutive cyclooxygenase-2 of MDCK cells in basal signaling and response to released ATP.

    PubMed

    Ostrom, R S; Gregorian, C; Drenan, R M; Gabot, K; Rana, B K; Insel, P A

    2001-08-01

    Madin-Darby canine kidney (MDCK) cells release ATP upon mechanical or biochemical activation, initiating P2Y receptor signaling that regulates basal levels of multiple second messengers, including cAMP (J Biol Chem 275: 11735--11739, 2000). Data shown here document inhibition of cAMP formation by Gd(3+) and niflumic acid, channel inhibitors that block ATP release. cAMP production is stimulated via Ca(2+)-dependent activation of cytosolic phospholipase A(2), release of arachidonic acid (AA), and cyclooxygenase (COX)-dependent production of prostaglandins, which activate prostanoid receptors coupled to G(s) and adenylyl cyclase. In the current investigation, we assessed the expression and functional role of the two known isoforms of COX, COX-1 and COX-2. Treatment of cells with either a COX-1-selective inhibitor, SC-560, or COX-2-selective inhibitors, SC-58125 or NS-398, inhibited basal and UTP-stimulated cAMP levels. COX inhibitors also decreased forskolin-stimulated cAMP formation, implying this response is in part attributable to an action of AA metabolites. These findings imply an important role for the inducible form of COX, COX-2, under basal conditions. Indeed, COX-2 expression was readily detectable by immunoblot, and treatments that induce or reduce COX-2 expression in other cells (interleukin-1beta, tumor necrosis factor-alpha, phorbol ester, or dexamethasone) had minimal or no effect on the levels of COX-2 immunoreactivity. RT-PCR using isoform-specific primers detected COX-2 mRNA. We conclude that COX-2 is constitutively expressed in MDCK-D(1) cells and participates in basal and P2Y(2)-mediated signaling, implying a key role for COX-2 in regulation of epithelial cell function. PMID:11443051

  11. Key role for constitutive cyclooxygenase-2 of MDCK cells in basal signaling and response to released ATP.

    PubMed

    Ostrom, R S; Gregorian, C; Drenan, R M; Gabot, K; Rana, B K; Insel, P A

    2001-08-01

    Madin-Darby canine kidney (MDCK) cells release ATP upon mechanical or biochemical activation, initiating P2Y receptor signaling that regulates basal levels of multiple second messengers, including cAMP (J Biol Chem 275: 11735--11739, 2000). Data shown here document inhibition of cAMP formation by Gd(3+) and niflumic acid, channel inhibitors that block ATP release. cAMP production is stimulated via Ca(2+)-dependent activation of cytosolic phospholipase A(2), release of arachidonic acid (AA), and cyclooxygenase (COX)-dependent production of prostaglandins, which activate prostanoid receptors coupled to G(s) and adenylyl cyclase. In the current investigation, we assessed the expression and functional role of the two known isoforms of COX, COX-1 and COX-2. Treatment of cells with either a COX-1-selective inhibitor, SC-560, or COX-2-selective inhibitors, SC-58125 or NS-398, inhibited basal and UTP-stimulated cAMP levels. COX inhibitors also decreased forskolin-stimulated cAMP formation, implying this response is in part attributable to an action of AA metabolites. These findings imply an important role for the inducible form of COX, COX-2, under basal conditions. Indeed, COX-2 expression was readily detectable by immunoblot, and treatments that induce or reduce COX-2 expression in other cells (interleukin-1beta, tumor necrosis factor-alpha, phorbol ester, or dexamethasone) had minimal or no effect on the levels of COX-2 immunoreactivity. RT-PCR using isoform-specific primers detected COX-2 mRNA. We conclude that COX-2 is constitutively expressed in MDCK-D(1) cells and participates in basal and P2Y(2)-mediated signaling, implying a key role for COX-2 in regulation of epithelial cell function.

  12. Protective Effects of Alisma orientale Extract against Hepatic Steatosis via Inhibition of Endoplasmic Reticulum Stress.

    PubMed

    Jang, Min-Kyung; Han, Yu-Ran; Nam, Jeong Soo; Han, Chang Woo; Kim, Byung Joo; Jeong, Han-Sol; Ha, Ki-Tae; Jung, Myeong Ho

    2015-01-01

    Endoplasmic reticulum (ER) stress is associated with the pathogenesis of hepatic steatosis. Alisma orientale Juzepzuk is a traditional medicinal herb for diuretics, diabetes, hepatitis, and inflammation. In this study, we investigated the protective effects of methanol extract of the tuber of Alisma orientale (MEAO) against ER stress-induced hepatic steatosis in vitro and in vivo. MEAO inhibited the tunicamycin-induced increase in luciferase activity of ER stress-reporter constructs containing ER stress response element and ATF6 response element. MEAO significantly inhibited tunicamycin-induced ER stress marker expression including GRP78, CHOP, and XBP-1 in tunicamycin-treated Human hepatocellular carcinoma (HepG2) cells and the livers of tunicamycin-injected mice. It also inhibited tunicamycin-induced accumulation of cellular triglyceride. Similar observations were made under physiological ER stress conditions such as in palmitate (PA)-treated HepG2 cells and the livers of high-fat diet (HFD)-induced obese mice. MEAO repressed hepatic lipogenic gene expression in PA-treated HepG2 cells and the livers of HFD obese mice. Furthermore, MEAO repressed very low-density lipoprotein receptor (VLDLR) expression and improved ApoB secretion in the livers of tunicamycin-injected mice or HFD obese mice as well as in tunicamycin or PA-treated HepG2 cells. Alismol, a guaiane-type sesquiterpenes in Alisma orientale, inhibited GRP78 expression in tunicamycin-treated HepG2 cells. In conclusion, MEAO attenuates ER stress and prevents hepatic steatosis pathogenesis via inhibition of expression of the hepatic lipogenic genes and VLDLR, and enhancement of ApoB secretion. PMID:26540043

  13. Protective Effects of Alisma orientale Extract against Hepatic Steatosis via Inhibition of Endoplasmic Reticulum Stress.

    PubMed

    Jang, Min-Kyung; Han, Yu-Ran; Nam, Jeong Soo; Han, Chang Woo; Kim, Byung Joo; Jeong, Han-Sol; Ha, Ki-Tae; Jung, Myeong Ho

    2015-11-02

    Endoplasmic reticulum (ER) stress is associated with the pathogenesis of hepatic steatosis. Alisma orientale Juzepzuk is a traditional medicinal herb for diuretics, diabetes, hepatitis, and inflammation. In this study, we investigated the protective effects of methanol extract of the tuber of Alisma orientale (MEAO) against ER stress-induced hepatic steatosis in vitro and in vivo. MEAO inhibited the tunicamycin-induced increase in luciferase activity of ER stress-reporter constructs containing ER stress response element and ATF6 response element. MEAO significantly inhibited tunicamycin-induced ER stress marker expression including GRP78, CHOP, and XBP-1 in tunicamycin-treated Human hepatocellular carcinoma (HepG2) cells and the livers of tunicamycin-injected mice. It also inhibited tunicamycin-induced accumulation of cellular triglyceride. Similar observations were made under physiological ER stress conditions such as in palmitate (PA)-treated HepG2 cells and the livers of high-fat diet (HFD)-induced obese mice. MEAO repressed hepatic lipogenic gene expression in PA-treated HepG2 cells and the livers of HFD obese mice. Furthermore, MEAO repressed very low-density lipoprotein receptor (VLDLR) expression and improved ApoB secretion in the livers of tunicamycin-injected mice or HFD obese mice as well as in tunicamycin or PA-treated HepG2 cells. Alismol, a guaiane-type sesquiterpenes in Alisma orientale, inhibited GRP78 expression in tunicamycin-treated HepG2 cells. In conclusion, MEAO attenuates ER stress and prevents hepatic steatosis pathogenesis via inhibition of expression of the hepatic lipogenic genes and VLDLR, and enhancement of ApoB secretion.

  14. Protective Effects of Alisma orientale Extract against Hepatic Steatosis via Inhibition of Endoplasmic Reticulum Stress

    PubMed Central

    Jang, Min-Kyung; Han, Yu-Ran; Nam, Jeong Soo; Han, Chang Woo; Kim, Byung Joo; Jeong, Han-Sol; Ha, Ki-Tae; Jung, Myeong Ho

    2015-01-01

    Endoplasmic reticulum (ER) stress is associated with the pathogenesis of hepatic steatosis. Alisma orientale Juzepzuk is a traditional medicinal herb for diuretics, diabetes, hepatitis, and inflammation. In this study, we investigated the protective effects of methanol extract of the tuber of Alisma orientale (MEAO) against ER stress-induced hepatic steatosis in vitro and in vivo. MEAO inhibited the tunicamycin-induced increase in luciferase activity of ER stress-reporter constructs containing ER stress response element and ATF6 response element. MEAO significantly inhibited tunicamycin-induced ER stress marker expression including GRP78, CHOP, and XBP-1 in tunicamycin-treated Human hepatocellular carcinoma (HepG2) cells and the livers of tunicamycin-injected mice. It also inhibited tunicamycin-induced accumulation of cellular triglyceride. Similar observations were made under physiological ER stress conditions such as in palmitate (PA)-treated HepG2 cells and the livers of high-fat diet (HFD)-induced obese mice. MEAO repressed hepatic lipogenic gene expression in PA-treated HepG2 cells and the livers of HFD obese mice. Furthermore, MEAO repressed very low-density lipoprotein receptor (VLDLR) expression and improved ApoB secretion in the livers of tunicamycin-injected mice or HFD obese mice as well as in tunicamycin or PA-treated HepG2 cells. Alismol, a guaiane-type sesquiterpenes in Alisma orientale, inhibited GRP78 expression in tunicamycin-treated HepG2 cells. In conclusion, MEAO attenuates ER stress and prevents hepatic steatosis pathogenesis via inhibition of expression of the hepatic lipogenic genes and VLDLR, and enhancement of ApoB secretion. PMID:26540043

  15. Angiotensin II activates the calcineurin/NFAT signaling pathway and induces cyclooxygenase-2 expression in rat endometrial stromal cells.

    PubMed

    Abraham, Florencia; Sacerdoti, Flavia; De León, Romina; Gentile, Teresa; Canellada, Andrea

    2012-01-01

    Cyclooxygenase (COX)-2, the inducible isoform of cyclooxygenase, plays a role in the process of uterine decidualization and blastocyst attachment. On the other hand, overexpression of COX-2 is involved in the proliferation of the endometrial tissue during endometriosis. Deregulation of the renin-angiotensin-system plays a role in the pathophysiology of endometriosis and pre-eclampsia. Angiotensin II increases intracellular Ca(2+) concentration by targeting phospholypase C-gamma in endometrial stromal cells (ESC). A key element of the cellular response to Ca(2+) signals is the activity of the Ca(2+)- and calmodulin-dependent phosphatase calcineurin. Our first aim was to study whether angiotensin II stimulated Cox-2 gene expression in rat ESC and to analyze whether calcineurin activity was involved. In cells isolated from non-pregnant uteri, COX-2 expression--both mRNA and protein--was induced by co-stimulation with phorbol ester and calcium ionophore (PIo), as well as by angiotensin II. Pretreatment with the calcineurin inhibitor cyclosporin A inhibited this induction. We further analyzed the role of the calcineurin/NFAT signaling pathway in the induction of Cox-2 gene expression in non-pregnant rat ESC. Cyclosporin A abolished NFATc1 dephosphorylation and translocation to the nucleus. Cyclosporin A also inhibited the transcriptional activity driven by the Cox-2 promoter. Exogenous expression of the peptide VIVIT -specific inhibitor of calcineurin/NFAT binding- blocked the activation of Cox-2 promoter and the up-regulation of COX-2 protein in these cells. Finally we analyzed Cox-2 gene expression in ESC of early-pregnant rats. COX-2 expression--both mRNA and protein--was induced by stimulation with PIo as well as by angiotensin II. This induction appears to be calcineurin independent, since it was not abrogated by cyclosporin A. In conclusion, angiotensin II induced Cox-2 gene expression by activating the calcineurin/NFAT signaling pathway in endometrial stromal

  16. Angiotensin II Activates the Calcineurin/NFAT Signaling Pathway and Induces Cyclooxygenase-2 Expression in Rat Endometrial Stromal Cells

    PubMed Central

    Abraham, Florencia; Sacerdoti, Flavia; De León, Romina; Gentile, Teresa; Canellada, Andrea

    2012-01-01

    Cyclooxygenase (COX)-2, the inducible isoform of cyclooxygenase, plays a role in the process of uterine decidualization and blastocyst attachment. On the other hand, overexpression of COX-2 is involved in the proliferation of the endometrial tissue during endometriosis. Deregulation of the renin-angiotensin-system plays a role in the pathophysiology of endometriosis and pre-eclampsia. Angiotensin II increases intracellular Ca2+ concentration by targeting phospholypase C-gamma in endometrial stromal cells (ESC). A key element of the cellular response to Ca2+ signals is the activity of the Ca2+- and calmodulin-dependent phosphatase calcineurin. Our first aim was to study whether angiotensin II stimulated Cox-2 gene expression in rat ESC and to analyze whether calcineurin activity was involved. In cells isolated from non-pregnant uteri, COX-2 expression -both mRNA and protein- was induced by co-stimulation with phorbol ester and calcium ionophore (PIo), as well as by angiotensin II. Pretreatment with the calcineurin inhibitor cyclosporin A inhibited this induction. We further analyzed the role of the calcineurin/NFAT signaling pathway in the induction of Cox-2 gene expression in non-pregnant rat ESC. Cyclosporin A abolished NFATc1 dephosphorylation and translocation to the nucleus. Cyclosporin A also inhibited the transcriptional activity driven by the Cox-2 promoter. Exogenous expression of the peptide VIVIT -specific inhibitor of calcineurin/NFAT binding- blocked the activation of Cox-2 promoter and the up-regulation of COX-2 protein in these cells. Finally we analyzed Cox-2 gene expression in ESC of early-pregnant rats. COX-2 expression -both mRNA and protein- was induced by stimulation with PIo as well as by angiotensin II. This induction appears to be calcineurin independent, since it was not abrogated by cyclosporin A. In conclusion, angiotensin II induced Cox-2 gene expression by activating the calcineurin/NFAT signaling pathway in endometrial stromal cells of

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

    PubMed Central

    Zhang, Ning; Liang, Hanyu; Farese, Robert V.; Li, Ji

    2015-01-01

    Aims To evaluate whether pharmacological TLR4 inhibition protects against acute and chronic fat-induced insulin resistance in rats. Materials and Methods For the acute experiment, rats received a TLR4 inhibitor [TAK-242 or E5564 (2x5 mg/kg i.v. bolus)] or vehicle, and an 8-h Intralipid (20%, 8.5 mg/kg/min) or saline infusion, followed by a two-step hyperinsulinemic-euglycemic clamp. For the chronic experiment, rats were subcutaneously implanted with a slow-release pellet of TAK-242 (1.5 mg/d) or placebo. Rats then received a high fat diet (HFD) or a low fat control diet (LFD) for 10 weeks, followed by a two-step insulin clamp. Results Acute experiment; the lipid-induced reduction (18%) in insulin-stimulated glucose disposal (Rd) was attenuated by TAK-242 and E5564 (the effect of E5564 was more robust), suggesting improved peripheral insulin action. Insulin was able to suppress hepatic glucose production (HGP) in saline- but not lipid-treated rats. TAK-242, but not E5564, partially restored this effect, suggesting improved HGP. Chronic experiment; insulin-stimulated Rd was reduced ~30% by the HFD, but completely restored by TAK-242. Insulin could not suppress HGP in rats fed a HFD and TAK-242 had no effect on HGP. Conclusions Pharmacological TLR4 inhibition provides partial protection against acute and chronic fat-induced insulin resistance in vivo. PMID:26196892

  18. Ginseng protects against respiratory syncytial virus by modulating multiple immune cells and inhibiting viral replication.

    PubMed

    Lee, Jong Seok; Lee, Yu-Na; Lee, Young-Tae; Hwang, Hye Suk; Kim, Ki-Hye; Ko, Eun-Ju; Kim, Min-Chul; Kang, Sang-Moo

    2015-01-01

    Ginseng has been used in humans for thousands of years but its effects on viral infection have not been well understood. We investigated the effects of red ginseng extract (RGE) on respiratory syncytial virus (RSV) infection using in vitro cell culture and in vivo mouse models. RGE partially protected human epithelial (HEp2) cells from RSV-induced cell death and viral replication. In addition, RGE significantly inhibited the production of RSV-induced pro-inflammatory cytokine (TNF-α) in murine dendritic and macrophage-like cells. More importantly, RGE intranasal pre-treatment prevented loss of mouse body weight after RSV infection. RGE treatment improved lung viral clearance and enhanced the production of interferon (IFN-γ) in bronchoalveolar lavage cells upon RSV infection of mice. Analysis of cellular phenotypes in bronchoalveolar lavage fluids showed that RGE treatment increased the populations of CD8+ T cells and CD11c+ dendritic cells upon RSV infection of mice. Taken together, these results provide evidence that ginseng has protective effects against RSV infection through multiple mechanisms, which include improving cell survival, partial inhibition of viral replication and modulation of cytokine production and types of immune cells migrating into the lung. PMID:25658239

  19. Semicarbazone EGA Inhibits Uptake of Diphtheria Toxin into Human Cells and Protects Cells from Intoxication

    PubMed Central

    Schnell, Leonie; Mittler, Ann-Katrin; Mattarei, Andrea; Tehran, Domenico Azarnia; Montecucco, Cesare; Barth, Holger

    2016-01-01

    Diphtheria toxin is a single-chain protein toxin that invades human cells by receptor-mediated endocytosis. In acidic endosomes, its translocation domain inserts into endosomal membranes and facilitates the transport of the catalytic domain (DTA) from endosomal lumen into the host cell cytosol. Here, DTA ADP-ribosylates elongation factor 2 inhibits protein synthesis and leads to cell death. The compound 4-bromobenzaldehyde N-(2,6-dimethylphenyl)semicarbazone (EGA) has been previously shown to protect cells from various bacterial protein toxins which deliver their enzymatic subunits from acidic endosomes to the cytosol, including Bacillus anthracis lethal toxin and the binary clostridial actin ADP-ribosylating toxins C2, iota and Clostridium difficile binary toxin (CDT). Here, we demonstrate that EGA also protects human cells from diphtheria toxin by inhibiting the pH-dependent translocation of DTA across cell membranes. The results suggest that EGA might serve for treatment and/or prevention of the severe disease diphtheria. PMID:27428999

  20. Semicarbazone EGA Inhibits Uptake of Diphtheria Toxin into Human Cells and Protects Cells Articlefrom Intoxication.

    PubMed

    Schnell, Leonie; Mittler, Ann-Katrin; Mattarei, Andrea; Tehran, Domenico Azarnia; Montecucco, Cesare; Barth, Holger

    2016-01-01

    Diphtheria toxin is a single-chain protein toxin that invades human cells by receptor-mediated endocytosis. In acidic endosomes, its translocation domain inserts into endosomal membranes and facilitates the transport of the catalytic domain (DTA) from endosomal lumen into the host cell cytosol. Here, DTA ADP-ribosylates elongation factor 2 inhibits protein synthesis and leads to cell death. The compound 4-bromobenzaldehyde N-(2,6-dimethylphenyl)semicarbazone (EGA) has been previously shown to protect cells from various bacterial protein toxins which deliver their enzymatic subunits from acidic endosomes to the cytosol, including Bacillus anthracis lethal toxin and the binary clostridial actin ADP-ribosylating toxins C2, iota and Clostridium difficile binary toxin (CDT). Here, we demonstrate that EGA also protects human cells from diphtheria toxin by inhibiting the pH-dependent translocation of DTA across cell membranes. The results suggest that EGA might serve for treatment and/or prevention of the severe disease diphtheria. PMID:27428999

  1. Effect of the major glycosides of Harpagophytum procumbens (Devil's Claw) on epidermal cyclooxygenase-2 (COX-2) in vitro.

    PubMed

    Abdelouahab, Nassima; Heard, Charles

    2008-05-01

    Harpagophytum procumbens, commonly known as Devil's Claw, is indigenous to southern Africa, and extracts of the tubers have been used for centuries in the treatment of a variety of inflammatory disorders. Its major active components, harpagoside (1), harpagide (2), 8-coumaroylharpagide (3), and verbascoside (4), are believed to interact either synergistically or antagonistically in modulating the enzymes responsible for inducing inflammation, although this has not been probed hitherto. In the current work, the ability of these compounds to inhibit the expression of COX-2 following administration to freshly excised porcine skin has been investigated. An ethanol-soluble extract of H. procumbens tubers and two of the pure compounds tested showed promising activity in Western blotting and immunocytochemical assays, with harpagoside (1) and 8-coumaroylharpagide (3) exhibiting greater reductions in COX-2 expression than verbascoside (4). Harpagide (2) caused a significant increase in the levels of COX-2 expression after 6 h of topical application. The data suggest that the efficacy of H. procumbens is dependent upon the ratios of compounds 1-4 present, which is inconsistent with some current official monograph specifications based solely on harpagoside (1) content. PMID:18412394

  2. Advanced glycation end products impair function of late endothelial progenitor cells through effects on protein kinase Akt and cyclooxygenase-2

    SciTech Connect

    Chen Qin; Dong Li; Wang Lian; Kang Lina; Xu Biao

    2009-04-03

    Endothelial progenitor cells (EPCs) exhibit impaired function in the context of diabetes, and advanced glycation end products (AGEs), which accumulate in diabetes, may contribute to this. In the present study, we investigated the mechanism by which AGEs impair late EPC function. EPCs from human umbilical cord blood were isolated, and incubated with AGE-modified albumin (AGE-albumin) at different concentrations found physiologically in plasma. Apoptosis, migration, and tube formation assays were used to evaluate EPC function including capacity for vasculogenesis, and expression of the receptor for AGEs (RAGE), Akt, endothelial nitric oxide synthase (eNOS), and cycloxygenase-2 (COX-2) were determined. Anti-RAGE antibody was used to block RAGE function. AGE-albumin concentration-dependently enhanced apoptosis and depressed migration and tube formation, but did not affect proliferation, of late EPCs. High AGE-albumin increased RAGE mRNA and protein expression, and decreased Akt and COX-2 protein expression, whilst having no effect on eNOS mRNA or protein in these cells. These effects were inhibited by co-incubation with anti-RAGE antibody. These results suggest that RAGE mediates the AGE-induced impairment of late EPC function, through down-regulation of Akt and COX-2 in these cells.

  3. Urethane dimethacrylate induces cytotoxicity and regulates cyclooxygenase-2, hemeoxygenase and carboxylesterase expression in human dental pulp cells.

    PubMed

    Chang, Hsiao-Hua; Chang, Mei-Chi; Wang, Hsin-Hui; Huang, Guay-Fen; Lee, Yuan-Ling; Wang, Yin-Lin; Chan, Chiu-Po; Yeung, Sin-Yuet; Tseng, Shuei-Kuen; Jeng, Jiiang-Huei

    2014-02-01

    The toxic effect of urethane dimethacrylate (UDMA), a major dental resin monomer, on human dental pulp is not fully clear. In this study, we investigated the influence of UDMA on the cytotoxicity, cell cycle distribution, apoptosis and related gene expression of dental pulp cells. The role of reactive oxygen species, hemeoxygenase-1 (HO-1) and carboxylesterase (CES) in UDMA cytotoxicity, was evaluated. UDMA induced morphological changes of pulp cells and decreased cell viability by 29-49% at concentrations of 0.1-0.35 mM. UDMA induced G0/G1, G2/M cell cycle arrest and apoptosis. The expression of cdc2, cyclinB1 and cdc25C was inhibited by UDMA. Moreover, UDMA stimulated COX-2, HO-1 and CES2 mRNA expression of pulp cells. The cytotoxicity of UDMA was attenuated by N-acetyl-l-cysteine, catalase and esterase, but was enhanced by Zn-protoporphyrin (HO-1 inhibitor), BNPP (CES inhibitor) and loperamide (CES2 inhibitor). Exposure of UDMA may potentially induce the inflammation and toxicity of dental pulp. These findings are important for understanding the clinical response of human pulp to resin monomers after operative restoration and pulp capping, and also provide clues for improvement of dental materials. PMID:24140606

  4. Action at a distance: mutations of peripheral residues transform rapid reversible inhibitors to slow, tight binders of cyclooxygenase-2.

    PubMed

    Blobaum, Anna L; Xu, Shu; Rowlinson, Scott W; Duggan, Kelsey C; Banerjee, Surajit; Kudalkar, Shalley N; Birmingham, William R; Ghebreselasie, Kebreab; Marnett, Lawrence J

    2015-05-15

    Cyclooxygenase enzymes (COX-1 and COX-2) catalyze the conversion of arachidonic acid to prostaglandin G2. The inhibitory activity of rapid, reversible COX inhibitors (ibuprofen, naproxen, mefenamic acid, and lumiracoxib) demonstrated a significant increase in potency and time dependence of inhibition against double tryptophan murine COX-2 mutants at the 89/90 and 89/119 positions. In contrast, the slow, time-dependent COX inhibitors (diclofenac, indomethacin, and flurbiprofen) were unaffected by those mutations. Further mutagenesis studies suggested that mutation at position 89 was principally responsible for the changes in inhibitory potency of rapid, reversible inhibitors, whereas mutation at position 90 may exert some effect on the potency of COX-2-selective diarylheterocycle inhibitors; no effect was observed with mutation at position 119. Several crystal structures with or without NSAIDs indicated that placement of a bulky residue at position 89 caused a closure of a gap at the lobby, and alteration of histidine to tryptophan at position 90 changed the electrostatic profile of the side pocket of COX-2. Thus, these two residues, especially Val-89 at the lobby region, are crucial for the entrance and exit of some NSAIDs from the COX active site.

  5. Trefoil peptides as proangiogenic factors in vivo and in vitro: implication of cyclooxygenase-2 and EGF receptor signaling.

    PubMed

    Rodrigues, Sylvie; Van Aken, Elisabeth; Van Bocxlaer, Saskia; Attoub, Samir; Nguyen, Quang-Dé; Bruyneel, Erik; Westley, Bruce R; May, Felicity E B; Thim, Lars; Mareel, Marc; Gespach, Christian; Emami, Shahin

    2003-01-01

    We previously established that the trefoil peptides (TFFs) pS2, spasmolytic polypeptide, and intestinal trefoil factor are involved in cellular scattering and invasion in kidney and colonic cancer cells. Using the chorioallantoic membrane (CAM) assay and the formation of tube-like structures by human umbilical vein endothelial cells (HUVEC) plated on the Matrigel matrix substratum, we report here that TFFs are proangiogenic factors. Angiogenic activity of TFFs is comparable to that induced by vascular endothelial growth factor, leptin, and transforming growth factor-alpha. Stimulation of angiogenesis by pS2 in the CAM assay is blocked by pharmacological inhibitors of cyclooxygenase COX-2 (NS-398) and epidermal growth factor receptor (EGF-R) tyrosine kinase (ZD1839), but is independent of KDR/Flk-1 and thromboxane A2 receptors. In contrast, the morphogenic switch induced by pS2 in HUVEC cells could be inhibited by the specific KDR heptapeptide antagonist ATWLPPR and by inhibitors of COX-2 and EGF-R signaling. These results implicate TFFs in the formation of new blood vessels during normal and pathophysiological processes linked to wound healing, inflammation, and cancer progression in the digestive mucosa and other human solid tumors associated with aberrant expression of TFFs.

  6. IL-15 protects NKT cells from inhibition by tumor-associated macrophages and enhances antimetastatic activity.

    PubMed

    Liu, Daofeng; Song, Liping; Wei, Jie; Courtney, Amy N; Gao, Xiuhua; Marinova, Ekaterina; Guo, Linjie; Heczey, Andras; Asgharzadeh, Shahab; Kim, Eugene; Dotti, Gianpietro; Metelitsa, Leonid S

    2012-06-01

    Vα24-invariant NKT cells inhibit tumor growth by targeting tumor-associated macrophages (TAMs). Tumor progression therefore requires that TAMs evade NKT cell activity through yet-unknown mechanisms. Here we report that a subset of cells in neuroblastoma (NB) cell lines and primary tumors expresses membrane-bound TNF-α (mbTNF-α). These proinflammatory tumor cells induced production of the chemokine CCL20 from TAMs via activation of the NF-κB signaling pathway, an effect that was amplified in hypoxia. Flow cytometry analyses of human primary NB tumors revealed selective accumulation of CCL20 in TAMs. Neutralization of the chemokine inhibited in vitro migration of NKT cells toward tumor-conditioned hypoxic monocytes and localization of NKT cells to NB grafts in mice. We also found that hypoxia impaired NKT cell viability and function. Thus, CCL20-producing TAMs served as a hypoxic trap for tumor-infiltrating NKT cells. IL-15 protected antigen-activated NKT cells from hypoxia, and transgenic expression of IL-15 in adoptively transferred NKT cells dramatically enhanced their antimetastatic activity in mice. Thus, tumor-induced chemokine production in hypoxic TAMs and consequent chemoattraction and inhibition of NKT cells represents a mechanism of immune escape that can be reversed by adoptive immunotherapy with IL-15-transduced NKT cells.

  7. Inhibition of PKR protects against tunicamycin-induced apoptosis in neuroblastoma cells.

    PubMed

    Vaughn, Lauren S; Snee, Brittany; Patel, Rekha C

    2014-02-15

    Endoplasmic reticulum (ER) dysfunction is thought to play a significant role in several neurological disorders, including Alzheimer's disease, Parkinson's disease, Huntington's disease, multiple sclerosis, amyotrophic lateral sclerosis, cerebral ischemia, and the prion diseases. ER dysfunction can be mimicked by cellular stress signals such as disruption of calcium homeostasis, inhibition of protein glycosylation, and reduction of disulfide bonds, which results in accumulation of misfolded proteins in the ER and leads to cell death by apoptosis. Tunicamycin, which is an inhibitor of protein glycosylation, induces ER stress and apoptosis. In this study, we examined the involvement of double stranded (ds) RNA-activated protein kinase PKR in tunicamycin-induced apoptosis. We used overexpression of the trans-dominant negative, catalytically inactive mutant K296R to inhibit PKR activity in neuroblastoma cells. We demonstrate that inhibition of PKR activation in response to tunicamycin protects neuronal cells from undergoing apoptosis. Furthermore, K296R overexpressing cells show defective PKR activation, delayed eIF2α phosphorylation, dramatically delayed ATF4 expression. In addition, both caspase-3 activation and C/EBP homologous protein (CHOP, also known as GADD153) induction, which are markers of apoptotic cells, are absent from K296R overexpression cells in response to tunicamycin. These results establish that PKR activation plays a major regulatory role in induction of apoptosis in response to ER stress and indicates the potential of PKR as possible target for neuroprotective therapeutics.

  8. Oxidative Stress-Dependent Cyclooxygenase-2-Derived Prostaglandin F2α Impairs Endothelial Function in Renovascular Hypertensive Rats

    PubMed Central

    Tian, Xiao Yu; Leung, Fung Ping; Zhang, Yang; Wang, Yi-Xiang; Lee, Hung Kay; Ng, Chi Fai; Chen, Zhen Yu; Yao, Xiaoqiang; Au, Chak Leung; Lau, Chi Wai; Vanhoutte, Paul M.; Cooke, John P.

    2012-01-01

    Abstract Aims: The role of endothelium-derived contracting factors (EDCFs) in regulating renovascular function is yet to be elucidated in renovascular hypertension (RH). The current study investigated whether oxidative stress-dependent cyclooxygenase (COX)-2-derived prostaglandin F2α (PGF2α) impairs endothelial function in renal arteries of renovascular hypertensive rats (RHR). Results: Renal hypertension was induced in rats by renal artery stenosis of both kidneys using the 2-kidney 2-clip model. Acute treatment with reactive oxygen species (ROS) scavengers, COX-2 inhibitors, and thromboxane-prostanoid receptor antagonists, but not COX-1 inhibitors, improved endothelium-dependent relaxations and eliminated endothelium-dependent contractions in RHR renal arteries. Five weeks of treatment with celecoxib or tempol reduced blood pressure, increased renal blood flow, and restored endothelial function in RHRs. Increased ROS production in RHR arteries was inhibited by ROS scavengers, but unaffected by COX-2 inhibitors; whereas increased PGF2α release was reduced by both ROS scavengers and COX-2 inhibitors. ROS also induced COX-2-dependent contraction in RHR renal arteries, which was accompanied by the release of COX-2-derived PGF2α. Further, chronic tempol treatment reduced COX-2 and BMP4 upregulation, p38MAPK phosphorylation, and the nitrotyrosine level in RHR renal arteries. Conclusion: These findings demonstrate the functional importance of oxidative stress, which serves as an initiator of increased COX-2 activity, and that COX-2-derived PGF2α plays an important role in mediating endothelial dysfunction in RH. Innovation: The current study, thus, suggests that drugs targeting oxidative stress-dependent COX-2-derived PGF2α may be useful in the prevention and management of RH. Antioxid. Redox Signal. 16, 363–373. PMID:21951274

  9. Pharmacokinetic–pharmacodynamic modelling of the analgesic effects of lumiracoxib, a selective inhibitor of cyclooxygenase-2, in rats

    PubMed Central

    Vásquez-Bahena, DA; Salazar-Morales, UE; Ortiz, MI; Castañeda-Hernández, G; Trocóniz, IF

    2010-01-01

    Background and purpose: This study establishes a pharmacokinetic/pharmacodynamic (PK/PD) model to describe the time course and in vivo mechanisms of action of the antinociceptive effects of lumiracoxib, evaluated by the thermal hyperalgesia test in rats. Experimental approach: Female Wistar fasted rats were injected s.c. with saline or carrageenan in the right hind paw, followed by either 0, 1, 3, 10 or 30 mg·kg−1 of oral lumiracoxib at the time of carrageenan injection (experiment I), or 0, 10 or 30 mg·kg−1 oral lumiracoxib at 4 h after carrageenan injection (experiment II). Antihyperalgesic responses were measured as latency time (LT) to a thermal stimulus. PK/PD modelling of the antinociceptive response was performed using the population approach with NONMEM VI. Results: A two-compartment model described the plasma disposition. A first-order model, including lag time and decreased relative bioavailability as a function of the dose, described the absorption process. The response model was: LT=LT0/(1 +MED). LT0 is the baseline response, and MED represents the level of inflammatory mediators. The time course of MED was assumed to be equivalent to the predicted profile of COX-2 activity and was modelled according to an indirect response model with a time variant synthesis rate. Drug effects were described as a reversible inhibition of the COX-2 activity. The in vivo estimate of the dissociation equilibrium constant of the COX-2-lumiracoxib complex was 0.24 µg·mL−1. Conclusions: The model developed appropriately described the time course of pharmacological responses to lumiracoxib, in terms of its mechanism of action and pharmacokinetics. PMID:19958362

  10. Induction of cyclo-oxygenase-2 mRNA by prostaglandin E2 in human prostatic carcinoma cells

    NASA Technical Reports Server (NTRS)

    Tjandrawinata, R. R.; Dahiya, R.; Hughes-Fulford, M.

    1997-01-01

    Prostaglandins are synthesized from arachidonic acid by the enzyme cyclo-oxygenase. There are two isoforms of cyclooxygenases: COX-1 (a constitutive form) and COX-2 (an inducible form). COX-2 has recently been categorized as an immediate-early gene and is associated with cellular growth and differentiation. The purpose of this study was to investigate the effects of exogenous dimethylprostaglandin E2 (dmPGE2) on prostate cancer cell growth. Results of these experiments demonstrate that administration of dmPGE2 to growing PC-3 cells significantly increased cellular proliferation (as measured by the cell number), total DNA content and endogenous PGE2 concentration. DmPGE2 also increased the steady-state mRNA levels of its own inducible synthesizing enzyme, COX-2, as well as cellular growth to levels similar to those seen with fetal calf serum and phorbol ester. The same results were observed in other human cancer cell types, such as the androgen-dependent LNCaP cells, breast cancer MDA-MB-134 cells and human colorectal carcinoma DiFi cells. In PC-3 cells, the dmPGE2 regulation of the COX-2 mRNA levels was both time dependent, with maximum stimulation seen 2 h after addition, and dose dependent on dmPGE2 concentration, with maximum stimulation seen at 5 microg ml(-1). The non-steroidal anti-inflammatory drug flurbiprofen (5 microM), in the presence of exogenous dmPGE2, inhibited the up-regulation of COX-2 mRNA and PC-3 cell growth. Taken together, these data suggest that PGE2 has a specific role in the maintenance of human cancer cell growth and that the activation of COX-2 expression depends primarily upon newly synthesized PGE2, perhaps resulting from changes in local cellular PGE2 concentrations.

  11. Dietary spices protect against hydrogen peroxide-induced DNA damage and inhibit nicotine-induced cancer cell migration.

    PubMed

    Jayakumar, R; Kanthimathi, M S

    2012-10-01

    Spices are rich sources of antioxidants due to the presence of phenols and flavonoids. In this study, the DNA protecting activity and inhibition of nicotine-induced cancer cell migration of 9 spices were analysed. Murine fibroblasts (3T3-L1) and human breast cancer (MCF-7) cells were pre-treated with spice extracts and then exposed to H₂O₂ and nicotine. The comet assay was used to analyse the DNA damage. Among the 9 spices, ginger, at 50 μg/ml protected against 68% of DNA damage in 3T3-L1 cells. Caraway, cumin and fennel showed statistically significant (p<0.05) DNA protecting activity. Treatment of MCF-7 cells with nicotine induced cell migration, whereas pre-treatment with spices reduced this migration. Pepper, long pepper and ginger exhibited a high rate of inhibition of cell migration. The results of this study prove that spices protect DNA and inhibit cancer cell migration. PMID:25005983

  12. Hydroxysafflor Yellow A Protects Neurons From Excitotoxic Death through Inhibition of NMDARs

    PubMed Central

    Wang, Xingtao; Ma, Zhiyuan; Fu, Zhongxiao; Gao, Su; Yang, Liu; Jin, Yan; Sun, Hui; Wang, Chaoyun; Fan, Weiming; Chen, Lin; Zheng, Qing-Yin; Bi, Guoqiang

    2016-01-01

    demonstrate for the first time that HSYA protects hippocampal neurons from excitotoxic damage through the inhibition of NMDARs. This novel finding indicates that HSYA may be a promising pharmacological candidate for the treatment of brain ischemia. PMID:27067428

  13. Hydroxysafflor Yellow A Protects Neurons From Excitotoxic Death through Inhibition of NMDARs.

    PubMed

    Wang, Xingtao; Ma, Zhiyuan; Fu, Zhongxiao; Gao, Su; Yang, Liu; Jin, Yan; Sun, Hui; Wang, Chaoyun; Fan, Weiming; Chen, Lin; Zheng, Qing-Yin; Bi, Guoqiang; Ma, Chun-Lei

    2016-01-01

    demonstrate for the first time that HSYA protects hippocampal neurons from excitotoxic damage through the inhibition of NMDARs. This novel finding indicates that HSYA may be a promising pharmacological candidate for the treatment of brain ischemia. PMID:27067428

  14. The secreted glycoprotein lubricin protects cartilage surfaces and inhibits synovial cell overgrowth

    PubMed Central

    Rhee, David K.; Marcelino, Jose; Baker, MacArthur; Gong, Yaoqin; Smits, Patrick; Lefebvre, Véronique; Jay, Gregory D.; Stewart, Matthew; Wang, Hongwei; Warman, Matthew L.; Carpten, John D.

    2005-01-01

    The long-term integrity of an articulating joint is dependent upon the nourishment of its cartilage component and the protection of the cartilage surface from friction-induced wear. Loss-of-function mutations in lubricin (a secreted glycoprotein encoded by the gene PRG4) cause the human autosomal recessive disorder camptodactyly-arthropathy-coxa vara-pericarditis syndrome (CACP). A major feature of CACP is precocious joint failure. In order to delineate the mechanism by which lubricin protects joints, we studied the expression of Prg4 mRNA during mouse joint development, and we created lubricin-mutant mice. Prg4 began to be expressed in surface chondrocytes and synoviocytes after joint cavitation had occurred and remained strongly expressed by these cells postnatally. Mice lacking lubricin were viable and fertile. In the newborn period, their joints appeared normal. As the mice aged, we observed abnormal protein deposits on the cartilage surface and disappearance of underlying superficial zone chondrocytes. In addition to cartilage surface changes and subsequent cartilage deterioration, intimal cells in the synovium surrounding the joint space became hyperplastic, which further contributed to joint failure. Purified or recombinant lubricin inhibited the growth of these synoviocytes in vitro. Tendon and tendon sheath involvement was present in the ankle joints, where morphologic changes and abnormal calcification of these structures were observed. We conclude that lubricin has multiple functions in articulating joints and tendons that include the protection of surfaces and the control of synovial cell growth. PMID:15719068

  15. Pancreatic spasmolytic polypeptide protects the gastric mucosa but does not inhibit acid secretion or motility.

    PubMed

    McKenzie, C; Marchbank, T; Playford, R J; Otto, W; Thim, L; Parsons, M E

    1997-07-01

    The objectives of these studies were to examine whether the trefoil peptide porcine pancreatic spasmolytic polypeptide (PSP) had gastric mucosal protectant properties similar to its human equivalent human spasmolytic polypeptide (hSP) and to confirm the antisecretory and antimotility action of the peptide. PSP and recombinant hSP reduced gastric mucosal damage caused by a combination of subcutaneous indomethacin and restraint stress in the conscious rat. At a dose of 500 micrograms/kg bolus plus 500 micrograms.kg-1.h-1 sc, PSP significantly reduced the total area of damage by 58%. PSP at a dose of 150 micrograms/kg iv had no inhibitory effect on pentagastrin-stimulated gastric acid secretion in the perfused stomachs of anesthetized rats. This lack of antisecretory activity was confirmed in vitro using an isolated stomach preparation from the immature rat. PSP and hSP at concentrations up to 800 nM did not inhibit electrically or chemically evoked contractions of the guinea pig ileum and duodenum in vitro. Thus antisecretory and antimotility actions do not underlie the mucosal protectant properties of PSP. PSP did, however, stimulate cell migration, and this may, at least in part, account for its protectant properties.

  16. Non-steroidal anti-inflammatory drugs and the risk of cardiovascular diseases: are we going to see the revival of cyclooxygenase-2 selective inhibitors?

    PubMed

    Głuszko, Piotr; Bielińska, Aneta

    2009-04-01

    The use of non-steroidal anti-inflammatory drugs (NSAID) is associated with a number of gastrointestinal and other adverse effects. Introduction of selective cyclooxygenase-2 (COX-2) inhibitors at the end of the 20th century raised hopes for a substantial reduction in the rate of serious events such as upper gastrointestinal ulcers, bleeding and perforations. In 2004 and 2005, predictions of some pharmacologists were confirmed when the Adenomatous Polyp Prevention on VIOXX trial (APPROVE) and other randomized, double-blind, placebo-controlled trials with COX-2 inhibitors showed an increased rate of thrombotic vascular events, including myocardial infarction, in patients treated with coxibs. So far, only limited long-term data on cardiovascular risk associated with non-selective NSAID have been available; however, some studies have suggested that both selective COX-2 inhibitors and traditional NSAID increase the risk of cardiovascular events. For patients at high cardiovascular risk, contradictory warnings and recommendations have been published recently by the American Heart Association, Food and Drug Administration, and by independent experts. The current paper reviews these recommendations and discusses the therapeutic challenge to minimize the risk of serious adverse events associated with the use of NSAID.

  17. Memory B cells from older people express normal levels of cyclooxygenase-2 and produce higher levels of IL-6 and IL-10 upon in vitro activation

    PubMed Central

    Bancos, Simona; Phipps, Richard P.

    2010-01-01

    Worldwide the elderly population is increasing. The elderly show deficiencies in immune function. B lymphocytes are essential elements of the immune system responsible for antibody production. This laboratory previously showed that activated human B cells isolated from young adults express cyclooxygenase-2 (Cox-2) and that Cox-2 is essential for optimal antibody responses. Recent data suggests that Cox-2 expression decreases with age in mouse bone tissue. There is no information regarding Cox-2 expression in B cells from older human subjects. We investigated the expression and activity of Cox-2 in naïve and memory B cells from older people. We show that B cells from older subjects show similar Cox-2 protein expression and activity, antibody production and proliferation compared to younger people. However, we found that activated memory B cells from older people produce higher levels of IL-6 and IL-10 compared to young adults. Therefore, the dysregulated cytokine production could contribute to immune senescence in the elderly. PMID:20889146

  18. Memory B cells from older people express normal levels of cyclooxygenase-2 and produce higher levels of IL-6 and IL-10 upon in vitro activation.

    PubMed

    Bancos, Simona; Phipps, Richard P

    2010-01-01

    Worldwide the elderly population is increasing. The elderly show deficiencies in immune function. B lymphocytes are essential elements of the immune system responsible for antibody production. This laboratory previously showed that activated human B cells isolated from young adults express cyclooxygenase-2 (Cox-2) and that Cox-2 is essential for optimal antibody responses. Recent data suggests that Cox-2 expression decreases with age in mouse bone tissue. There is no information regarding Cox-2 expression in B cells from older human subjects. We investigated the expression and activity of Cox-2 in naïve and memory B cells from older people. We show that B cells from older subjects show similar Cox-2 protein expression and activity, antibody production and proliferation compared to younger people. However, we found that activated memory B cells from older people produce higher levels of IL-6 and IL-10 compared to young adults. Therefore, the dysregulated cytokine production could contribute to immune senescence in the elderly.

  19. Gq protein mediates UVB-induced cyclooxygenase-2 expression by stimulating HB-EGF secretion from HaCaT human keratinocytes

    SciTech Connect

    Seo, MiRan; Juhnn, Yong-Sung

    2010-03-05

    Ultraviolet (UV) radiation induces cyclooxygenase-2 expression to produce cellular responses including aging and carcinogenesis in skin. We hypothesised that heterotrimeric G proteins mediate UV-induced COX-2 expression by stimulating secretion of soluble HB-EGF (sHB-EGF). In this study, we aimed to elucidate the role and underlying mechanism of the {alpha} subunit of Gq protein (G{alpha}q) in UVB-induced HB-EGF secretion and COX-2 induction. We found that expression of constitutively active G{alpha}q (G{alpha}qQL) augmented UVB-induced HB-EGF secretion, which was abolished by knockdown of G{alpha}q with shRNA in HaCaT human keratinocytes. G{alpha}q was found to mediate the UVB-induced HB-EGF secretion by sequential activation of phospholipase C (PLC), protein kinase C{delta} (PKC{delta}), and matrix metaloprotease-2 (MMP-2). Moreover, G{alpha}qQL mediated UVB-induced COX-2 expression in an HB-EGF-, EGFR-, and p38-dependent manner. From these results, we concluded that G{alpha}q mediates UV-induced COX-2 expression through activation of EGFR by HB-EGF, of which ectodomain shedding was stimulated through sequential activation of PLC, PKC{delta} and MMP-2 in HaCaT cells.

  20. Localized inflammation in peripheral tissue signals the CNS for sickness response in the absence of interleukin-1 and cyclooxygenase-2 in the blood and brain.

    PubMed

    Zhang, H; Ching, S; Chen, Q; Li, Q; An, Y; Quan, N

    2008-12-10

    The CNS can be activated by both local and systemic inflammation, resulting in the manifestation of sickness symptoms. The pathways by which the CNS is activated under these two conditions, however, may differ. In this study, we injected casein into the peritoneal cavity (i.p.) or into an s.c. air pouch of mice to induce restricted local inflammation. Both routes of casein injection caused fever and reduced locomotor activity. These responses were not accompanied by the statistically significant induction of the inflammatory cytokine interleukin-1 (IL-1) in the blood and brain. Further, these responses were produced without the induction of brain cyclooxygenase-2 (COX-2), which has been implicated as an obligatory step in systemic inflammation-induced activation of the CNS. Induction of IL-1, interleukin-6 (IL-6), and COX-2, however, was found consistently at the sites of casein injection. The local inflammation-induced febrile and locomotor activity responses were blunted in animals deficient in functional Toll-like receptor 4 (TLR4), type I interleukin-1 receptor (IL-1R1), IL-6, or COX-2. Therefore, the observed febrile and locomotor activity effects appear to require local, but not central, IL-1, IL-6, and COX-2. These findings suggest that local inflammation can activate the CNS via pathways distinguishable from those mediating systemic inflammation-induced CNS activation.

  1. Date syrup-derived polyphenols attenuate angiogenic responses and exhibits anti-inflammatory activity mediated by vascular endothelial growth factor and cyclooxygenase-2 expression in endothelial cells.

    PubMed

    Taleb, Hajer; Morris, R Keith; Withycombe, Cathryn E; Maddocks, Sarah E; Kanekanian, Ara D

    2016-07-01

    Bioactive components such as polyphenols, present in many plants, are purported to have anti-inflammatory and antiangiogenic properties. Date syrup, produced from date fruit of the date palm tree, has traditionally been used to treat a wide range of diseases with etiologies involving angiogenesis and inflammation. It was hypothesized that polyphenols in date syrup reduce angiogenic responses such as cell migration, tube formation, and matrix metalloproteinase activity in an inflammatory model by exhibiting anti-inflammatory activity mediated by vascular endothelial growth factor (VEGF) and the prostaglandin enzyme cyclooxygenase-2 (COX-2) in endothelial cells. Date syrup polyphenols at 60 and 600μg/mL reduced inflammation and suppressed several stages of angiogenesis, including endothelial cell migration, invasion, matrix metalloproteinase activity, and tube formation, without evidence of cytotoxicity. VEGF and COX-2 expression induced by tumor necrosis factor-alpha at both gene expression and protein level was significantly reduced by date syrup polyphenols in comparison to untreated cells. In conclusion, polyphenols in date syrup attenuated angiogenic responses and exhibited anti-inflammatory activity mediated by VEGF and COX-2 expression in endothelial cells. PMID:27333954

  2. Expression of cyclooxygenase-2, alpha 1-acid-glycoprotein and inducible nitric oxide synthase in the developing lesions of murine leprosy

    PubMed Central

    Silva Miranda, Mayra; Rodríguez, Kendy Wek; Martínez Cordero, Erasmo; Rojas-Espinosa, Oscar

    2006-01-01

    Murine leprosy is a chronic disease of the mouse, the most popular animal model used in biomedical investigation, which is caused by Mycobacterium lepraemurium (MLM) whose characteristic lesion is the macrophage-made granuloma. From onset to the end of the disease, the granuloma undergoes changes that gradually transform the environment into a more appropriate milieu for the growth of M. lepraemurium. The mechanisms that participate in the formation and maturation of the murine leprosy granulomas are not completely understood; however, microbial and host-factors are believed to participate in their formation. In this study, we analysed the role of various pro-inflammatory and anti-inflammatory proteins in granulomas of murine leprosy after 21 weeks of infection. We assessed the expression of cyclooxygenase-2 (COX-2), alpha acid-glycoprotein (AGP), and inducible nitric oxide synthase (iNOS) at sequential stages of infection. We also looked for the nitric-oxide nitrosylation product, nitrotyrosine (NT) in the granulomatous lesions of murine leprosy. We found that a pro-inflammatory environment predominates in the early granulomas while an anti-inflammatory environment predominates in late granulomas. No obvious signs of bacillary destruction were observed during the entire period of infection, but nitrosylation products and cell alterations were observed in granulomas in the advanced stages of disease. The change from a pro-inflammatory to an anti-inflammatory environment, which is probably driven by the bacillus itself, results in a more conducive environment for both bacillus replication and the disease progression. PMID:17222216

  3. Role of phosphorylated extracellular signal-regulated kinase, calcitonin gene-related peptide and cyclooxygenase-2 in experimental rat models of migraine.

    PubMed

    Dong, Xiaomeng; Hu, Yaozhi; Jing, Long; Chen, Jinbo

    2015-08-01

    Although migraine is a common neurological condition, the pathomechanism is not yet fully understood. Activation of the trigeminovascular system (TVS) has an important function in this disorder and neurogenic inflammation and central sensitization are important mechanisms underlying this condition. Nitroglycerin (NTG) infusion in rats closely mimics a universally accepted human model of migraine. Electrical stimulation of the trigeminal ganglion (ESTG) of rats can also activate TVS during a migraine attack. Numerous studies have revealed that phosphorylated extracellular signal-regulated kinase (p-ERK), calcitonin gene-related peptide (CGRP) and cyclooxygenase-2 (COX-2) are involved in pain and nociceptive pathways. However, few studies have examined whether p-ERK, CGRP and COX-2 are involved in neurogenic inflammation and central sensitization. In the present study, the expression of p-ERK, CGRP and COX-2 was detected in the dura mater, trigeminal ganglion (TG) and spinal trigeminal nucleus caudalis in NTG-induced rats and ESTG models by immunohistochemistry. The three areas considered were crucial components of the TVS. The selective COX-2 inhibitor nimesulide was used in ESTG rats to examine the association between p-ERK, CGRP and COX-2. The results demonstrated that p‑ERK, CGRP and COX-2 mediated neurogenic inflammation and central sensitization in migraine. In addition, the expression of p-ERK and CGRP was attenuated by the COX-2 inhibitor.

  4. Cyclooxygenase-2 expression in lipopolysaccharide-stimulated human monocytes is modulated by cyclic AMP, prostaglandin E(2), and nonsteroidal anti-inflammatory drugs.

    PubMed

    Hinz, B; Brune, K; Pahl, A

    2000-11-30

    Using human blood monocytes (for determination of cyclooxygenase-2 (COX-2) mRNA by RT-PCR) and human whole blood (for prostanoid determination), the present study investigates the influence of the second messenger cAMP on lipopolysaccharide (LPS)-induced COX-2 expression with particular emphasis on the role of prostaglandin E(2) (PGE(2)) in this process. Elevation of intracellular cAMP with a cell-permeable cAMP analogue (dibutyryl cAMP), an adenylyl cyclase activator (cholera toxin), or a phosphodiesterase inhibitor (3-isobutyl-1-methylxanthine) substantially enhanced LPS-induced PGE(2) formation and COX-2 mRNA expression, but did not modify COX-2 enzyme activity. Moreover, up-regulation of LPS-induced COX-2 expression was caused by PGE(2), butaprost (selective agonist of the adenylyl cyclase-coupled EP(2) receptor) and 11-deoxy PGE(1) (EP(2)/EP(4) agonist), whereas sulprostone (EP(3)/EP(1) agonist) left COX-2 expression unaltered. Abrogation of LPS-induced PGE(2) synthesis with the selective COX-2 inhibitor NS-398 caused a decrease in COX-2 mRNA levels that was restored by exogenous PGE(2) and mimicked by S(+)-flurbiprofen and ketoprofen. Overall, these results indicate a modulatory role of cAMP in the regulation of COX-2 expression. PGE(2), a cAMP-elevating final product of the COX-2 pathway, may autoregulate COX-2 expression in human monocytes via a positive feedback mechanism.

  5. Induction of cyclooxygenase-2 by ginsenoside Rd via activation of CCAAT-enhancer binding proteins and cyclic AMP response binding protein

    SciTech Connect

    Jeong, Hye Gwang; Pokharel, Yuba Raj; Han, Eun Hee; Kang, Keon Wook . E-mail: kwkang@chosun.ac.kr

    2007-07-20

    Panax ginseng is a widely used herbal medicine in East Asia and is reported to have a variety of pharmacological effects against cardiovascular diseases and cancers. Here we show a unique effect of ginsenoside Rd (Rd) on cyclooxygenase-2 (COX-2) expression in RAW264.7 macrophages. Rd (100 {mu}g/ml), but not other ginsenosides induced COX-2 and increased prostaglandin E{sub 2} production. Gel shift and Western blot analyses using nuclear fractions revealed that Rd increased both the DNA binding of and the nuclear levels of CCAAT/enhancer binding protein (C/EBP){alpha}/{beta} and cyclic AMP response element binding protein (CREB), but not of p65, in RAW264.7 cells. Moreover, Rd increased the luciferase reporter gene activity in cells transfected with a 574-bp mouse COX-2 promoter construct. Site-specific mutation analyses confirmed that Rd-mediated transcriptional activation of COX-2 gene was regulated by C/EBP and CREB. These results provide evidence that Rd activated C/EBP and CREB, and that the activation of C/EBP and CREB appears to be essential for induction of COX-2 in RAW264.7 cells.

  6. Relationship between the expression of cyclooxygenase 2 and MDR1/P-glycoprotein in invasive breast cancers and their prognostic significance

    PubMed Central

    Surowiak, Pawel; Materna, Verena; Matkowski, Rafal; Szczuraszek, Katarzyna; Kornafel, Jan; Wojnar, Andrzej; Pudelko, Marek; Dietel, Manfred; Denkert, Carsten; Zabel, Maciej; Lage, Hermann

    2005-01-01

    Introduction Recent reports suggest that expression of the cyclooxygenase 2 (COX-2) enzyme may up-regulate expression of MDR1/P-glycoprotein (MDR1/P-gp), an exponent of resistance to cytostatic drugs. The present study aimed at examining the relationship between the expression of COX-2 and of MDR1/P-gp in a group of breast cancer cases. Methods Immunohistochemical reactions were performed using monoclonal antibodies against COX-2 and MDR1/P-gp on samples originating from 104 cases of primary invasive breast cancer. Results COX-2-positive cases were shown to demonstrate higher expression of MDR1/P-gp (P < 0.0001). The studies also demonstrate that COX-2 expression was typical for cases of a higher grade (P = 0.01), a shorter overall survival time (P < 0.0001) and a shorter progression-free time (P < 0.0001). In the case of MDR1/P-gp, its higher expression characterised cases of a higher grade (P < 0001), with lymph node involvement (P < 0001), and shorter overall survival (P < 0.0001) and progression-free time (P < 0.0001). Conclusion Our studies confirmed the unfavourable prognostic significance of COX-2 and MDR1/P-gp. We also document a relationship between COX-2 and MDR1/P-gp, which suggests that COX-2 inhibitors should be investigated in trials as a treatment supplementary to chemotherapy of breast cancers. PMID:16168133

  7. Cyclooxygenase-2 Silencing for the Treatment of Colitis: A Combined In Vivo Strategy Based on RNA Interference and Engineered Escherichia Coli

    PubMed Central

    Spisni, Enzo; Valerii, Maria C; De Fazio, Luigia; Cavazza, Elena; Borsetti, Francesca; Sgromo, Annamaria; Candela, Marco; Centanni, Manuela; Rizello, Fernando; Strillacci, Antonio

    2015-01-01

    Nonpathogenic-invasive Escherichia coli (InvColi) bacteria are suitable for genetic transfer into mammalian cells and may act as a vehicle for RNA Interference (RNAi) in vivo. Cyclooxygenase-2 (COX-2) is overexpressed in ulcerative colitis (UC) and Crohn's disease (CD), two inflammatory conditions of the colon and small intestine grouped as inflammatory bowel disease (IBD). We engineered InvColi strains for anti-COX-2 RNAi (InvColishCOX2), aiming to investigate the in vivo feasibility of a novel COX-2 silencing strategy in a murine model of colitis induced by dextran sulfate sodium (DSS). Enema administrations of InvColishCOX2 in DSS-treated mice led to COX-2 downregulation, colonic mucosa preservation, reduced colitis disease activity index (DAI) and increased mice survival. Moreover, DSS/InvColishCOX2-treated mice showed lower levels of circulating pro-inflammatory cytokines and a reduced colitis-associated shift of gut microbiota. Considering its effectiveness and safety, we propose our InvColishCOX2 strategy as a promising tool for molecular therapy in intestinal inflammatory diseases. PMID:25393372

  8. Nuclear factor {kappa}B (NF{kappa}B) and cyclooxygenase-2 (Cox-2) expression in the irradiated colorectum is associated with subsequent histopathological changes

    SciTech Connect

    Yeoh, Ann S.J. . E-mail: ann.yeoh@imvs.sa.gov.au; Bowen, Joanne M.; Gibson, Rachel J.; Keefe, Dorothy M.K.

    2005-12-01

    Purpose: Recent studies have proposed that mucositis development is the same throughout the gastrointestinal tract (GIT), as it is formed from one structure embryologically. Radiation-induced oral mucositis studies have outlined the key involvement of nuclear factor {kappa}B (NF{kappa}B) and cyclooxygenase-2 (Cox-2) in its pathobiology. The purpose of this study was therefore to investigate the expression of NF{kappa}B and Cox-2 in the irradiated colorectum and to correlate these with the associated histopathologic changes. Methods and Materials: Colorectal tissues from 28 colorectal cancer patients treated with preoperative radiotherapy were analyzed for histopathologic changes using a variety of tissue staining methods. The expression of NF{kappa}B and Cox-2 in these tissues was investigated using immunohistochemistry. Changes in expression of these proteins were then correlated with the histopathologic changes. Results: Radiation therapy caused injury to the normal colorectal tissue surrounding tumor site, particularly around the blood vessels. These changes were reflected in changes in NF{kappa}B and Cox-2 expression. Conclusions: We conclude that different regions of the GIT, the colorectum, and oral cavity have similar underlying mechanisms of radiation-induced mucositis. Understanding these mechanisms will allow new approaches to be developed to specifically target steps in the evolution of alimentary mucositis.

  9. Cyclooxygenase-2 -1195G>A (rs689466) polymorphism and cancer susceptibility: an updated meta-analysis involving 50,672 subjects

    PubMed Central

    Wang, Yafeng; Jiang, Heping; Liu, Tianyun; Tang, Weifeng; Ma, Zhiqiang

    2015-01-01

    The association between cyclooxygenase-2 (COX-2) -1195G>A (rs689466) polymorphism and cancer risk has been extensively explored. However, the results of previous studies remain controversial. To address this gap, we performed an updated meta-analysis of fifty-eight studies involving a total of 50,672 subjects. Searching of PubMed and Embase databases was performed for publications on the association between COX-2 -1195G>A polymorphism and the risk of cancer. Statistical correlation was identified between COX-2 -1195G>A variants and overall cancer risk in five genetic models. In a sub-group analysis based on cancer type, significant association between COX-2 -1195G>A polymorphism and increased risk of gastric cancer, pancreatic cancer, hepatocellular carcinoma and other cancers was found. In a sub-group analysis by ethnicity, increased cancer risk was observed among Asians instead of Caucasians, Africans and mixed populations. Furthermore, in a sub-group analysis based on cancer system, increased cancer risk was found in digestive system cancer and other system cancer. Non-parametric “trim-and-fill” method was harnessed as a sensitivity analysis method and the results suggested our findings reliable. In summary, the results of our meta-analysis highlight that COX-2 -1195G>A polymorphism may be a risk factor for cancer. PMID:26550156

  10. Selective Inhibition of the Mitochondrial Permeability Transition Pore Protects against Neurodegeneration in Experimental Multiple Sclerosis*

    PubMed Central

    Warne, Justin; Pryce, Gareth; Hill, Julia M.; Shi, Xiao; Lennerås, Felicia; Puentes, Fabiola; Kip, Maarten; Hilditch, Laura; Walker, Paul; Simone, Michela I.; Chan, A. W. Edith; Towers, Greg J.; Coker, Alun R.; Duchen, Michael R.; Szabadkai, Gyorgy; Baker, David; Selwood, David L.

    2016-01-01

    The mitochondrial permeability transition pore is a recognized drug target for neurodegenerative conditions such as multiple sclerosis and for ischemia-reperfusion injury in the brain and heart. The peptidylprolyl isomerase, cyclophilin D (CypD, PPIF), is a positive regulator of the pore, and genetic down-regulation or knock-out improves outcomes in disease models. Current inhibitors of peptidylprolyl isomerases show no selectivity between the tightly conserved cyclophilin paralogs and exhibit significant off-target effects, immunosuppression, and toxicity. We therefore designed and synthesized a new mitochondrially targeted CypD inhibitor, JW47, using a quinolinium cation tethered to cyclosporine. X-ray analysis was used to validate the design concept, and biological evaluation revealed selective cellular inhibition of CypD and the permeability transition pore with reduced cellular toxicity compared with cyclosporine. In an experimental autoimmune encephalomyelitis disease model of neurodegeneration in multiple sclerosis, JW47 demonstrated significant protection of axons and improved motor assessments with minimal immunosuppression. These findings suggest that selective CypD inhibition may represent a viable therapeutic strategy for MS and identify quinolinium as a mitochondrial targeting group for in vivo use. PMID:26679998

  11. Selective Inhibition of the Mitochondrial Permeability Transition Pore Protects against Neurodegeneration in Experimental Multiple Sclerosis.

    PubMed

    Warne, Justin; Pryce, Gareth; Hill, Julia M; Shi, Xiao; Lennerås, Felicia; Puentes, Fabiola; Kip, Maarten; Hilditch, Laura; Walker, Paul; Simone, Michela I; Chan, A W Edith; Towers, Greg J; Coker, Alun R; Duchen, Michael R; Szabadkai, Gyorgy; Baker, David; Selwood, David L

    2016-02-26

    The mitochondrial permeability transition pore is a recognized drug target for neurodegenerative conditions such as multiple sclerosis and for ischemia-reperfusion injury in the brain and heart. The peptidylprolyl isomerase, cyclophilin D (CypD, PPIF), is a positive regulator of the pore, and genetic down-regulation or knock-out improves outcomes in disease models. Current inhibitors of peptidylprolyl isomerases show no selectivity between the tightly conserved cyclophilin paralogs and exhibit significant off-target effects, immunosuppression, and toxicity. We therefore designed and synthesized a new mitochondrially targeted CypD inhibitor, JW47, using a quinolinium cation tethered to cyclosporine. X-ray analysis was used to validate the design concept, and biological evaluation revealed selective cellular inhibition of CypD and the permeability transition pore with reduced cellular toxicity compared with cyclosporine. In an experimental autoimmune encephalomyelitis disease model of neurodegeneration in multiple sclerosis, JW47 demonstrated significant protection of axons and improved motor assessments with minimal immunosuppression. These findings suggest that selective CypD inhibition may represent a viable therapeutic strategy for MS and identify quinolinium as a mitochondrial targeting group for in vivo use.

  12. Dipeptidyl-peptidase 4 Inhibition: Linking Metabolic Control to Cardiovascular Protection

    PubMed Central

    Avogaro, Angelo; de Kreutzenberg, Saula; Fadini, Gianpaolo

    2014-01-01

    Dipeptidyl peptidases 4 (DPP4) inhibitors are a new class of oral anti-hyperglycemic drugs for the treatment of type 2 diabetes (T2DM). They are also called “incretins” because they act by inhibiting the degradation of endogenous incretin hormones, in particular GLP-1, that mediates their main metabolic effects. DPP4 is an ubiquitous protease that regulates not only glucose and lipid metabolism, but also exhibits several systemic effects at different site levels. DPP4 inhibition improves endothelial function, reduces the pro-oxidative and the pro-inflammatory state, and exerts renal effects. These actions are mediated by different DPP4 ligands, such as cytokines, growth factors, neuotransmitters etc. Clinical and experimental studies have demonstrated that DPP4 inhibitors are efficient in protecting cardiac, renal and vascular systems, through antiatherosclerotic and vasculoprotective mechanisms. For these reasons DDP4 inhibitors are thought to be “cardiovascular protective” as well as anti-diabetic drugs. Clinical trials aimed to demonstrate the efficacy of DPP4 inhibitors in reducing cardiovascular events, independent of their anti-hyperglycemic action, are ongoing. These trials will also give necessary information on their safety. PMID:23844811

  13. Selective Inhibition of the Mitochondrial Permeability Transition Pore Protects against Neurodegeneration in Experimental Multiple Sclerosis.

    PubMed

    Warne, Justin; Pryce, Gareth; Hill, Julia M; Shi, Xiao; Lennerås, Felicia; Puentes, Fabiola; Kip, Maarten; Hilditch, Laura; Walker, Paul; Simone, Michela I; Chan, A W Edith; Towers, Greg J; Coker, Alun R; Duchen, Michael R; Szabadkai, Gyorgy; Baker, David; Selwood, David L

    2016-02-26

    The mitochondrial permeability transition pore is a recognized drug target for neurodegenerative conditions such as multiple sclerosis and for ischemia-reperfusion injury in the brain and heart. The peptidylprolyl isomerase, cyclophilin D (CypD, PPIF), is a positive regulator of the pore, and genetic down-regulation or knock-out improves outcomes in disease models. Current inhibitors of peptidylprolyl isomerases show no selectivity between the tightly conserved cyclophilin paralogs and exhibit significant off-target effects, immunosuppression, and toxicity. We therefore designed and synthesized a new mitochondrially targeted CypD inhibitor, JW47, using a quinolinium cation tethered to cyclosporine. X-ray analysis was used to validate the design concept, and biological evaluation revealed selective cellular inhibition of CypD and the permeability transition pore with reduced cellular toxicity compared with cyclosporine. In an experimental autoimmune encephalomyelitis disease model of neurodegeneration in multiple sclerosis, JW47 demonstrated significant protection of axons and improved motor assessments with minimal immunosuppression. These findings suggest that selective CypD inhibition may represent a viable therapeutic strategy for MS and identify quinolinium as a mitochondrial targeting group for in vivo use. PMID:26679998

  14. Inhibition of Rho Kinase (ROCK) Leads to Increased Cerebral Blood Flow and Stroke Protection

    PubMed Central

    Rikitake, Yoshiyuki; Kim, Hyung-Hwan; Huang, Zhihong; Seto, Minoru; Yano, Kazuo; Asano, Toshio; Moskowitz, Michael A.; Liao, James K.

    2009-01-01

    Background and Purpose Endothelium-derived nitric oxide (NO) plays a pivotal role in vascular protection. The Rho kinase (ROCK) inhibitor, hydroxyfasudil, prevents the downregulation of endothelial NO synthase (eNOS) under hypoxic conditions. However, it is unknown whether inhibition of ROCK can attenuate ischemia-induced endothelial dysfunction and tissue damage in vivo. Methods Human vascular endothelial cells were treated with increasing concentrations of hydroxyfasudil (0.1 to 100 μmol/L) and eNOS expression and activity were measured. To determine the physiological relevance of eNOS regulation by ROCK, we administered fasudil, which is metabolized to hydroxyfasudil in vivo, to mice for 2 days before subjecting them to middle cerebral artery occlusion. Cerebral blood flow, cerebral infarct size, and neurologic deficit were measured. Results In a concentration-dependent manner, hydroxyfasudil increased eNOS mRNA and protein expression, resulting in a 1.9- and 1.6-fold increase, respectively, at 10 μmol/L (P<0.05 for both). This correlated with a 1.5- and 2.3-fold increase in eNOS activity and NO production, respectively (P<0.05 for both). Fasudil increased cerebral blood flow to both ischemic and nonischemic brain areas, reduced cerebral infarct size by 33%, and improved neurologic deficit score by 37% (P<0.05). This correlated with inhibition of brain and vascular ROCK activity and increased eNOS expression and activity. Another ROCK inhibitor, Y-27632, also showed similar effects. The neuroprotective effects of fasudil were absent in eNOS-deficient mice. Conclusions These findings indicate that the neuroprotective effect of ROCK inhibition is mediated by endothelium-derived NO and suggest that ROCK may be an important therapeutic target for ischemic stroke. PMID:16141422

  15. Inhibition of fungal spore adhesion by zosteric Acid as the basis for a novel, nontoxic crop protection technology.

    PubMed

    Stanley, Michele S; Callow, Maureen E; Perry, Ruth; Alberte, Randall S; Smith, Robert; Callow, James A

    2002-04-01

    ABSTRACT To explore the potential for nontoxic crop protection technologies based on the inhibition of fungal spore adhesion, we have tested the effect of synthetic zosteric acid (p-(sulfo-oxy) cinnamic acid), a naturally occurring phenolic acid in eelgrass (Zostera marina L.) plants, on spore adhesion and infection in two pathosystems: rice blast caused by Magnaporthe grisea and bean anthracnose caused by Colletotrichum lindemuthianum. We have shown that zosteric acid inhibits spore adhesion to model and host leaf surfaces and that any attached spores fail to develop appressoria, and consequently do not infect leaf cells. Low concentrations of zosteric acid that are effective in inhibiting adhesion are not toxic to either fungus or to the host. The inhibition of spore adhesion in the rice blast pathogen is fully reversible. On plants, zosteric acid reduced (rice) or delayed (bean) lesion development. These results suggest that there is potential for novel and environmentally benign crop protection technologies based on manipulating adhesion.

  16. Melanin protects Paracoccidioides brasiliensis from the effects of antimicrobial photodynamic inhibition and antifungal drugs.

    PubMed

    Baltazar, Ludmila Matos; Werneck, Silvia Maria Cordeiro; Soares, Betânia Maria; Ferreira, Marcus Vinicius L; Souza, Danielle G; Pinotti, Marcos; Santos, Daniel Assis; Cisalpino, Patrícia Silva

    2015-07-01

    Paracoccidioidomycosis (PCM) is a public health concern in Latin America and South America that when not correctly treated can lead to patient death. In this study, the influence of melanin produced by Paracoccidioides spp. on the effects of treatment with antimicrobial photodynamic inhibition (aPI) and antifungal drugs was evaluated. aPI was performed using toluidine blue (TBO) as a photosensitizer and a 630-nm light-emitting diode (LED) light. The antifungals tested were itraconazole and amphotericin B. We evaluated the effects of each approach, aPI or antifungals, against nonmelanized and melanized yeast cells by performing susceptibility tests and by quantifying oxidative and nitrosative bursts during the experiments. aPI reduced nonmelanized cells by 3.0 log units and melanized cells by 1.3 log units. The results showed that melanization protects the fungal cell, probably by acting as a scavenger of nitric oxide and reactive oxygen species, but not of peroxynitrite. Melanin also increased the MICs of itraconazole and amphotericin B, and the drugs were fungicidal for nonmelanized and fungistatic for melanized yeast cells. Our study shows that melanin production by Paracoccidioides yeast cells serves a protective function during aPI and treatment with itraconazole and amphotericin B. The results suggest that melanin binds to the drugs, changing their antifungal activities, and also acts as a scavenger of reactive oxygen species and nitric oxide, but not of peroxynitrite, indicating that peroxynitrite is the main radical that is responsible for fungal death after aPI.

  17. Phycocyanin and phycocyanobilin from Spirulina platensis protect against diabetic nephropathy by inhibiting oxidative stress.

    PubMed

    Zheng, Jing; Inoguchi, Toyoshi; Sasaki, Shuji; Maeda, Yasutaka; McCarty, Mark F; Fujii, Masakazu; Ikeda, Noriko; Kobayashi, Kunihisa; Sonoda, Noriyuki; Takayanagi, Ryoichi

    2013-01-15

    We and other investigators have reported that bilirubin and its precursor biliverdin may have beneficial effects on diabetic vascular complications, including nephropathy, via its antioxidant effects. Here, we investigated whether phycocyanin derived from Spirulina platensis, a blue-green algae, and its chromophore phycocyanobilin, which has a chemical structure similar to that of biliverdin, protect against oxidative stress and renal dysfunction in db/db mice, a rodent model for Type 2 diabetes. Oral administration of phycocyanin (300 mg/kg) for 10 wk protected against albuminuria and renal mesangial expansion in db/db mice, and normalized tumor growth factor-β and fibronectin expression. Phycocyanin also normalized urinary and renal oxidative stress markers and the expression of NAD(P)H oxidase components. Similar antioxidant effects were observed following oral administration of phycocyanobilin (15 mg/kg) for 2 wk. Phycocyanobilin, bilirubin, and biliverdin also inhibited NADPH dependent superoxide production in cultured renal mesangial cells. In conclusion, oral administration of phycocyanin and phycocyanobilin may offer a novel and feasible therapeutic approach for preventing diabetic nephropathy. PMID:23115122

  18. Phycocyanin and phycocyanobilin from Spirulina platensis protect against diabetic nephropathy by inhibiting oxidative stress.

    PubMed

    Zheng, Jing; Inoguchi, Toyoshi; Sasaki, Shuji; Maeda, Yasutaka; McCarty, Mark F; Fujii, Masakazu; Ikeda, Noriko; Kobayashi, Kunihisa; Sonoda, Noriyuki; Takayanagi, Ryoichi

    2013-01-15

    We and other investigators have reported that bilirubin and its precursor biliverdin may have beneficial effects on diabetic vascular complications, including nephropathy, via its antioxidant effects. Here, we investigated whether phycocyanin derived from Spirulina platensis, a blue-green algae, and its chromophore phycocyanobilin, which has a chemical structure similar to that of biliverdin, protect against oxidative stress and renal dysfunction in db/db mice, a rodent model for Type 2 diabetes. Oral administration of phycocyanin (300 mg/kg) for 10 wk protected against albuminuria and renal mesangial expansion in db/db mice, and normalized tumor growth factor-β and fibronectin expression. Phycocyanin also normalized urinary and renal oxidative stress markers and the expression of NAD(P)H oxidase components. Similar antioxidant effects were observed following oral administration of phycocyanobilin (15 mg/kg) for 2 wk. Phycocyanobilin, bilirubin, and biliverdin also inhibited NADPH dependent superoxide production in cultured renal mesangial cells. In conclusion, oral administration of phycocyanin and phycocyanobilin may offer a novel and feasible therapeutic approach for preventing diabetic nephropathy.

  19. BDNF/TrkB signaling protects HT-29 human colon cancer cells from EGFR inhibition

    SciTech Connect

    Brunetto de Farias, Caroline; Heinen, Tiago Elias; Pereira dos Santos, Rafael; Abujamra, Ana Lucia; Schwartsmann, Gilberto; and others

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer BDNF protected HT-29 colorectal cancer cells from the antitumor effect of cetuximab. Black-Right-Pointing-Pointer TrkB inhibition potentiated the antitumor effect of cetuximab. Black-Right-Pointing-Pointer BDNF/TrkB signaling might be involved in resistance to anti-EGFR therapy. -- Abstract: The clinical success of targeted treatment of colorectal cancer (CRC) is often limited by resistance to anti-epidermal growth factor receptor (EGFR) therapy. The neurotrophin brain-derived neurotrophic factor (BDNF) and its receptor TrkB have recently emerged as anticancer targets, and we have previously shown increased BDNF levels in CRC tumor samples. Here we report the findings from in vitro experiments suggesting that BDNF/TrkB signaling can protect CRC cells from the antitumor effects of EGFR blockade. The anti-EGFR monoclonal antibody cetuximab reduced both cell proliferation and the mRNA expression of BDNF and TrkB in human HT-29 CRC cells. The inhibitory effect of cetuximab on cell proliferation and survival was counteracted by the addition of human recombinant BDNF. Finally, the Trk inhibitor K252a synergistically enhanced the effect of cetuximab on cell proliferation, and this effect was blocked by BDNF. These results provide the first evidence that increased BDNF/TrkB signaling might play a role in resistance to EGFR blockade. Moreover, it is possible that targeting TrkB could potentiate the anticancer effects of anti-EGFR therapy.

  20. Biofilm, ice recrystallization inhibition and freeze-thaw protection in an epiphyte community.

    PubMed

    Wu, Z; Kan, F W K; She, Y-M; Walker, V K

    2012-01-01

    Microbial communities found on the surface of overwintering plants may be exposed to low temperatures as well as multiple freeze-thaw events. To explore the adaptive mechanisms of these epiphytes, with the objective of identifying products for freeze-protection, enrichment libraries were made from frost-exposed leaves. Of 15 identified bacteria from 60 individual clones, approximately half had ice-association activities, with the great majority showing high freeze-thaw resistance. Isolates with ice nucleation activity and ice recrystallization inhibition activity were recovered. Of the latter, two (Erwinia billingiae J10, and Sphingobacterium kitahiroshimense Y2) showed culture and electron microscopic evidence of motility and/or biofilm production. Mass spectrometric characterization of the E. billingiae extracellular polymeric substance (EPS) identified the major proteins as 35 kDa outer membrane protein A and F, supporting its biofilm character. The addition of the EPS preparation increased the freeze-thaw survival of the more susceptible bacteria 1000-10000 times, and protection was at least partially dependent on the protein component.

  1. Protective role of cyclooxygenase inhibitors in the adverse action of passive cigarette smoking on the initiation of experimental colitis in rats.

    PubMed

    Guo, X; Liu, E S; Ko, J K; Wong, B C; Ye, Y; Lam, S; Cho, C

    2001-01-01

    Clinical and experimental findings had indicated that cigarette smoke exposure, and cyclooxygenase-2, are strongly associated with inflammatory bowel disease. The present study aimed to evaluate the role of cyclooxygenase-2 in the pathogenesis of experimental inflammatory bowel disease as well as in the adverse action of cigarette-smoke exposure. Rats were pretreated with different cyclooxygenase-2 inhibitors (indomethacin, nimesulide, or SC-236 (4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzenesulfonamide)) along with cigarette-smoke exposure before 2,4,6-trinitrobenzenesulfonic acid-enema. Results indicated that pretreatment with cyclooxygenase-2 inhibitors not only protected against 2,4,6-trinitrobenzenesulfonic acid-induced inflammatory bowel disease, but also attenuated the potentiating effect of cigarette-smoke exposure on colonic damage. Furthermore, the colonic cyclooxygenase-2 protein and mRNA expression was markedly induced by 2,4,6-trinitrobenzenesulfonic acid-enema, and it was potentiated further by cigarette-smoke exposure, while the cyclooxygenase-1 expression was not changed. The present study suggests that the highly induced cyclooxygenase-2 expression not only plays a pathogenic role in 2,4,6-trinitrobenzenesulfonic acid-induced inflammatory bowel disease, but also contributes to the adverse action of cigarette-smoke exposure on this disorder.

  2. Role of cyclo-oxygenase-2 induction in interleukin-1β induced attenuation of cultured human airway smooth muscle cell cyclic AMP generation in response to isoprenaline

    PubMed Central

    Pang, Linhua; Holland, Elaine; Knox, Alan J

    1998-01-01

    Airway smooth muscle (ASM) in human asthma shows reduced relaxation and cyclic AMP generation in response to β-adrenoceptor agonists. IL-β attenuates cyclic AMP generation but the underlying mechanism is unclear. We have reported that IL-1β induces cyclo-oxygenase-2 (COX-2) in human ASM cells and results in a marked increase in prostanoid generation with PGE2 and PGI2 as the major products.We investigated the role of COX-2 induction and prostanoid release (measured as PGE2) in IL-1β induced attenuation of cyclic AMP generation in response to the β-adrenoceptor agonist isoprenaline (ISO).Pre-treatment of human ASM cells with IL-1β significantly attenuated cyclic AMP generation in response to high concentrations of ISO (1.0–10.0 μM) in a time- and concentration-dependent manner. The effect was accompanied by a high concentration of PGE2 release. The non-selective COX inhibitor indomethacin (Ind), the selective COX-2 inhibitor NS-398, the protein synthesis inhibitors cycloheximide (CHX) and actinomycin D and the steroid dexamethasone (Dex) all abolished the PGE2 release and prevented the attenuated cyclic AMP generation.COX substrate arachidonic acid time- and concentration-dependently mimicked IL-1β induced attenuation and the effect was prevented by the non-selective COX inhibitors Ind and flurbiprofen, but not by NS-398, CHX and Dex.In contrast to IL-1β, TNFα and IFNγ, which are ineffective in inducing COX-2 and releasing PGE2 from human ASM cells, did not affect the cyclic AMP formation.Our study demonstrates that COX-2 induction and the consequent release of prostanoids plays a crucial role in IL-1β induced attenuation of human ASM cell cyclic AMP response to ISO. PMID:9863663

  3. Arachidonoyl-ethanolamide activates endoplasmic reticulum stress-apoptosis in tumorigenic keratinocytes: Role of cyclooxygenase-2 and novel J-series prostamides.

    PubMed

    Soliman, Eman; Henderson, Kate L; Danell, Allison S; Van Dross, Rukiyah

    2016-02-01

    Non-melanoma skin cancer and other epithelial tumors overexpress cyclooxygenase-2 (COX-2), differentiating them from normal cells. COX-2 metabolizes arachidonic acid to prostaglandins including, the J-series prostaglandins, which induce apoptosis by mechanisms including endoplasmic reticulum (ER) stress. Arachidonoyl-ethanolamide (AEA) is a cannabinoid that causes apoptosis in diverse tumor types. Previous studies from our group demonstrated that AEA was metabolized by COX-2 to J-series prostaglandins. Thus, the current study examines the role of COX-2, J-series prostaglandins, and ER stress in AEA-induced apoptosis. In tumorigenic keratinocytes that overexpress COX-2, AEA activated the PKR-like ER kinase (PERK), inositol requiring kinase-1 (IRE1), and activating transcription factor-6 (ATF6) ER stress pathways and the ER stress apoptosis-associated proteins, C/EBP homologous protein-10 (CHOP10), caspase-12, and caspase-3. Using an ER stress inhibitor, it was determined that ER stress was required for AEA-induced apoptosis. To evaluate the role of COX-2 in ER stress-apoptosis, HaCaT keratinocytes with low endogenous COX-2 expression were transfected with COX-2 cDNA or an empty vector and AEA-induced ER stress-apoptosis occurred only in the presence of COX-2. Moreover, LC-MS analysis showed that the novel prostaglandins, 15-deoxyΔ(12,14) PGJ2 -EA and Δ(12) PGJ2 /PGJ2-EA, were synthesized from AEA. These findings suggest that AEA will be selectively toxic in tumor cells that overexpress COX-2 due to the metabolism of AEA by COX-2 to J-series prostaglandin-ethanolamides (prostamides). Hence, AEA may be an ideal topical agent for the elimination of malignancies that overexpress COX-2.

  4. Estrogen-Dependent Prognostic Significance of Cyclooxygenase-2 Expression in Early-Stage Invasive Breast Cancers Treated With Breast-Conserving Surgery and Radiation

    SciTech Connect

    Haffty, Bruce G. Yang Qifeng; Moran, Meena S.; Tan, Antoinette R.; Reiss, Michael

    2008-07-15

    Purpose: To evaluate the prognostic significance of cyclooxygenase-2 (COX-2) in breast cancer patients treated with conservative surgery and radiation therapy (CS+RT). Methods and Materials: Between 1975 and 2003, we retrieved specimens from 504 breast cancer patients treated with CS+RT. The specimens were constructed into tissue microarrays processed and stained for estrogen receptor (ER), progesterone receptor, Her2/neu, and COX-2. Each core was scored as positive or negative. All data including demographics, clinical, pathologic, staging, and outcome variables were entered into a computerized database. Results: Expression of COX-2 was positive in 58% of cases and correlated with younger age (p = 0.01) and larger tumor size (p 0.001). Expression of COX-2 was predictive of local relapse (relative risk[RR], 3.248; 95% confidence interval [CI], 1.340-7.871; p = 0.0091), distant metastasis (RR, 2.21; 95% CI, 1.259-3.896; p = 0.0058), and decreased survival (RR, 2.321; 95% CI, 1.324-4.071; p = 0.0033). Among ER-positive patients, COX-2 expression was predictive of worse local control (85% vs. 93%, p = 0.04), distant metastasis (75% vs. 95%, p = 0.002) and worse survival (65% vs. 94%, p = 0.002). Among ER-negative tumors COX-2 expression was not significantly correlated with local control (87 vs. 95%, p = 0.12), distant metastasis (73% vs. 78%, p = 0.39), or survival (77% vs. 87%, p 0.15). Conclusions: In breast cancer patients treated with CS+RT, COX-2 expression is associated with younger age, larger tumor size, worse local control, distant metastasis, and worse overall survival. The significance is limited to hormone receptor-positive tumors, consistent with the known effect of COX-2/PGE2 on aromatase activity. Use of COX-2 inhibitors in estrogen-dependent breast cancers warrants further investigation.

  5. Arachidonoyl-ethanolamide activates endoplasmic reticulum stress-apoptosis in tumorigenic keratinocytes: Role of cyclooxygenase-2 and novel J-series prostamides.

    PubMed

    Soliman, Eman; Henderson, Kate L; Danell, Allison S; Van Dross, Rukiyah

    2016-02-01

    Non-melanoma skin cancer and other epithelial tumors overexpress cyclooxygenase-2 (COX-2), differentiating them from normal cells. COX-2 metabolizes arachidonic acid to prostaglandins including, the J-series prostaglandins, which induce apoptosis by mechanisms including endoplasmic reticulum (ER) stress. Arachidonoyl-ethanolamide (AEA) is a cannabinoid that causes apoptosis in diverse tumor types. Previous studies from our group demonstrated that AEA was metabolized by COX-2 to J-series prostaglandins. Thus, the current study examines the role of COX-2, J-series prostaglandins, and ER stress in AEA-induced apoptosis. In tumorigenic keratinocytes that overexpress COX-2, AEA activated the PKR-like ER kinase (PERK), inositol requiring kinase-1 (IRE1), and activating transcription factor-6 (ATF6) ER stress pathways and the ER stress apoptosis-associated proteins, C/EBP homologous protein-10 (CHOP10), caspase-12, and caspase-3. Using an ER stress inhibitor, it was determined that ER stress was required for AEA-induced apoptosis. To evaluate the role of COX-2 in ER stress-apoptosis, HaCaT keratinocytes with low endogenous COX-2 expression were transfected with COX-2 cDNA or an empty vector and AEA-induced ER stress-apoptosis occurred only in the presence of COX-2. Moreover, LC-MS analysis showed that the novel prostaglandins, 15-deoxyΔ(12,14) PGJ2 -EA and Δ(12) PGJ2 /PGJ2-EA, were synthesized from AEA. These findings suggest that AEA will be selectively toxic in tumor cells that overexpress COX-2 due to the metabolism of AEA by COX-2 to J-series prostaglandin-ethanolamides (prostamides). Hence, AEA may be an ideal topical agent for the elimination of malignancies that overexpress COX-2. PMID:25557612

  6. Kainic acid-induced neurodegeneration and activation of inflammatory processes in organotypic hippocampal slice cultures: treatment with cyclooxygenase-2 inhibitor does not prevent neuronal death.

    PubMed

    Järvelä, Juha T; Ruohonen, Saku; Kukko-Lukjanov, Tiina-Kaisa; Plysjuk, Anna; Lopez-Picon, Francisco R; Holopainen, Irma E

    2011-06-01

    In the postnatal rodent hippocampus status epilepticus (SE) leads to age- and region-specific excitotoxic neuronal damage, the precise mechanisms of which are still incompletely known. Recent studies suggest that the activation of inflammatory responses together with glial cell reactivity highly contribute to excitotoxic neuronal damage. However, pharmacological tools to attenuate their activation in the postnatal brain are still poorly elucidated. In this study, we investigated the role of inflammatory mediators in kainic acid (KA)-induced neuronal damage in organotypic hippocampal slice cultures (OHCs). A specific cyclooxygenase-2 (COX-2) inhibitor N-[2-(cyclohexyloxy)-4-nitrophenyl]-methanesulfonamide (NS-398) was used to study whether or not it could ameliorate neuronal death. Our results show that KA treatment (24 h) resulted in a dose-dependent degeneration of CA3a/b pyramidal neurons. Furthermore, COX-2 immunoreactivity was pronouncedly enhanced particularly in CA3c pyramidal neurons, microglial and astrocyte morphology changed from a resting to active appearance, the expression of the microglial specific protein, Iba1, increased, and prostaglandin E₂ (PGE₂) production increased. These indicated the activation of inflammatory processes. However, the expression of neither proinflammatory cytokines, i.e. tumour necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β), nor the anti-inflammatory cytokine IL-10 mRNA was significantly altered by KA treatment as studied by real-time PCR. Despite activation of an array of inflammatory processes, neuronal damage could not be rescued either with the combined pre- and co-treatment with a specific COX-2 inhibitor, NS-398. Our results suggest that KA induces activation of a repertoire of inflammatory processes in immature OHCs, and that the timing of anti-inflammatory treatment to achieve neuroprotection is a challenge due to developmental properties and the complexity of inflammatory processes activated by

  7. Clinical Significance of Hu-Antigen Receptor (HuR) and Cyclooxygenase-2 (COX-2) Expression in Human Malignant and Benign Thyroid Lesions.

    PubMed

    Giaginis, Constantinos; Alexandrou, Paraskevi; Delladetsima, Ioanna; Karavokyros, Ioannis; Danas, Eugene; Giagini, Athina; Patsouris, Efstratios; Theocharis, Stamatios

    2016-01-01

    Hu-antigen R (HuR) is considered to play a crucial role in tumor formation and growth by binding to mRNAs encoding proteins such as Cyclooxygenase-2 (COX-2) and inducing their expression via mRNA stabilization and/or altered translation. The present study aimed to evaluate the clinical significance of HuR and COX-2 proteins’ expression in human benign and malignant thyroid lesions. HuR and COX-2 proteins’ expression was assessed immunohistochemically on paraffin-embedded thyroid tissues obtained from 98 patients with benign (n = 48) and malignant (n = 50) lesions and was statistically analyzed with clinicopathological parameters, follicular cells’ proliferative capacity and recurrence risk rate. Enhanced HuR and COX-2 expression was significantly more frequently observed in malignant compared to benign thyroid lesions (p = 0.0073 and p = 0.0016, respectively), as well as in papillary carcinomas compared to hyperplastic nodules (p = 0.0039 and p = 0.0009, respectively). Positive associations of both HuR and COX-2 expression with follicular cells’ proliferation rate were also noted (p = 0.0087 and p = 0.0127, respectively). In malignant thyroid lesions, elevated COX-2 expression was significantly associated with female patients’ gender (p = 0.0381) and the presence of lymph node metastases (p = 0.0296). The present data support evidence that both HuR and COX-2 may be involved in the malignant state of thyroid neoplasia and may be utilized in the diagnosis of malignant thyroid tumors.

  8. Common polymorphisms of cyclooxygenase-2 and prostaglandin E2 receptor and increased risk for acute coronary syndrome in coronary artery disease.

    PubMed

    Szczeklik, Wojciech; Sanak, Marek; Rostoff, Pawel; Piwowarska, Wieslawa; Jakiela, Bogdan; Szczeklik, Andrew

    2008-11-01

    The arachidonic acid metabolites participate in development of coronary artery disease (CAD) and the plaque's instability. We assessed two common genetic polymorphisms: of cyclooxygenase-2 (COX-2) (COX2.8473, rs5275) and prostaglandin EP2 receptor gene (uS5, rs708494) in patients with CAD. Out of 1,368 patients screened by coronary arteriography, two groups fulfilled the entry criteria and were studied: stable coronary disease (sCAD, n = 125) and acute coronary syndromes (ACS, n = 63). They did not differ in the main characteristics. All patients were on aspirin at least seven days prior to the study. In 70 control subjects, the same genotypes were ascertained, expression of cyclooxygenases in peripheral blood monocytes was assessed by flow cytometry, and in-vitro biosynthesis of PGE(2) was measured by mass spectrometry. COX-2 CC homozygotes (variant allele), were more common, while EP2 GG homozygotes (wild-type) were less common in ACS (p = 0.03 and p = 0.017) than in the sCAD group. A combined genotype characterized by the presence of the wild-type COX2.8743T allele and the wild type homozygous EP2uS5 genotype (TT or CT | GG) decreased risk ratio of ACS in CAD patients (relative risk 0.41; 95% confidence interval 0.21-0.81). COX-2 polymorphism in control subjects did not affect the enzyme expression or PGE(2) production by peripheral blood monocytes, but production of PGE(2) increased by 40.1% in the subjects homozygous for EP2 receptor allele uS5A following lipopolysaccharide stimulation. In conclusion, the combined COX-2 (COX2.8473) and the EP2 receptor (uS5) genotypes seem to influence CAD stability, but in peripheral blood monocytes only EP2 receptor modulates PGE(2) production. PMID:18989535

  9. Up-regulation of cyclooxygenase-2 by cobalt chloride-induced hypoxia is mediated by phospholipase D isozymes in human astroglioma cells.

    PubMed

    Ahn, Bong-Hyun; Park, Mi Hee; Lee, Young Han; Kwon, Taeg Kyu; Min, Do Sik

    2007-12-01

    Cyclooxygenase-2 (COX-2) is an isoform of prostaglandin H synthase induced by hypoxia and has been implicated in the growth and progression of a variety of human cancers. In the present study, we investigated the role of phospholipase D (PLD) isozymes in cobalt chloride (CoCl(2))-induced hypoxia-driven COX-2 expression in U87 MG human astroglioma cells. CoCl(2) stimulated PLD activity and synthesis of COX-2 protein in a dose and time-dependent manner. Moreover, elevated expression of PLD1 and PLD2 increased hypoxia-induced COX-2 expression and prostaglandin E2 (PGE(2)) production. Pretreatment of cells with 1-butanol, but not 3-butanol, suppressed CoCl(2)-induced COX-2 expression and PGE(2) formation. In addition, evidence that PLD activity was involved in the stimulation of COX-2 expression was provided by the observations that overexpression of wild type PLD isozymes, but not catalytically inactive PLD isozymes, stimulated CoCl(2)-induced COX-2 expression and PGE(2) production. PLD1 enhanced COX-2 expression by CoCl(2) via reactive oxygen species (ROS), p38 MAPK kinase, PKC-delta, and PKA, but not ERK, whereas PLD2 enhanced CoCl(2)-induced COX-2 expression via ROS and p38 MAPK, but not ERK, PKC-delta, and PKA. Differential regulation of COX-2 expression mediated through PLD isozymes was comparable with that of CoCl(2)-induced PLD activity in these two PLD isozymes. Taken together, our results demonstrate for the first time that PLD1 and PLD2 isozymes enhance CoCl(2)-induced COX-2 expression through differential signaling pathways in astroglioma cells.

  10. Progestin treatment does not affect expression of cytokines, steroid receptors, oxytocin receptor, and cyclooxygenase 2 in fetal membranes and endometrium from pony mares at parturition.

    PubMed

    Palm, F; Walter, I; Nowotny, N; Budik, S; Helmreich, M; Aurich, C

    2013-01-01

    In most mammalian species, progestins have a major function in maintaining pregnancy. In humans, the physiologic initiation of parturition bears similarities with inflammatory processes and anti-inflammatory effects of progestins have been suggested to postpone birth until term. To examine if comparable effects exist in the horse, mares were treated with the synthetic progestin altrenogest from day 280 of gestation until parturition (N = 5) or were left untreated as controls (N = 7). Tissue from the amnion (AMN), allantochorion (AC), and endometrium (EM) was collected at foaling and mRNA expression of interleukin (IL)-6 and -8, cyclooxygenase 2 (COX2), estrogen receptor (ER) α, progesterone receptor, and oxytocin receptor (OTR) was analyzed. Leukocytes, steroid receptors, COX2, and OTR were also investigated by histology and immunohistochemistry. Expression of mRNA for IL-6 was higher in AMN and EM versus AC (P < 0.01). Expression of IL-8 was higher in AMN than AC and EM (P < 0.001). Steroid receptors and OTR were highly expressed in EM but not in AMN and AC (P < 0.001). Expression of COX2 was most pronounced in AC whereas IL expression was not upregulated in AC. No differences in mRNA expression existed between altrenogest-treated and control animals. Endometrial polymorphonuclear leukocytes were increased in altrenogest-treated mares. Epithelial cells of all tissues, except AC chorionic villi stained progesterone receptor-positive. Staining for ER was more pronounced in the amnion facing epithelium of the AC in altrenogest-treated versus control animals (P < 0.01). In conclusion, COX2 is highly expressed in the AC. The fetal membranes thus might play a role in the onset of labor in the horse. Altrenogest did not affect gene expression in the AMN, AC, and EM but had localized effects on inflammatory cells and ER expression. No anti-inflammatory effects of altrenogest in healthy, late pregnant pony mares could be detected.

  11. Cytokine-mediated induction of cyclo-oxygenase-2 by activation of tyrosine kinase in bovine endothelial cells stimulated by bacterial lipopolysaccharide.

    PubMed Central

    Akarasereenont, P.; Bakhle, Y. S.; Thiemermann, C.; Vane, J. R.

    1995-01-01

    1. The induction of cyclo-oxygenase-2 (COX-2) afforded by bacterial lipopolysaccharide (LPS, endotoxin) in bovine aortic endothelial cells (BAEC) is mediated by tyrosine kinase. LPS also causes the generation of several cytokines including interleukin-1 beta (IL-1 beta), tumour necrosis factor-alpha (TNF-alpha), epidermal growth factor (EGF) and platelet-derived growth factor (PDGF). This study investigates whether endogenous IL-1 beta, TNF-alpha, EGF or PDGF contribute to the induction of COX-2 elicited by LPS in BAEC and if their action is due to activation of tyrosine kinase. Furthermore, we have studied the induction of COX-2 by exogenous cytokines. 2. Accumulation of 6-oxo-prostaglandin (PG) F1 alpha in cultures of BAEC was measured by radioimmunoassay at 24 h after addition of either LPS (1 microgram ml-1) alone or LPS together with a polyclonal antibody to one of the various cytokines. In experiments designed to measure 'COX activity', 6-oxo-PGF1 alpha generated by BAEC activated with recombinant human IL-1 beta, TNF-alpha, EGF or PDGF for 12 h was measured after incubation of washed cells with exogenous arachidonic acid (30 microM for 15 min). Western blot analysis determined the expression of COX-2 protein in BAEC. 3. The accumulation of 6-oxo-PGF1 alpha caused by LPS in BAEC was attenuated by co-incubation with one of the polyclonal antibodies, anti-IL-1 beta, anti-TNF-alpha, anti-EGF, anti-PDGF or with the IL-1 receptor antagonist, in a dose-dependent manner. Exogenous IL-1 beta, TNF-alpha or EGF also caused an increase in COX activity, while PDGF was ineffective.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 4 PMID:7582449

  12. Underwater trauma causes a long-term specific increase in the expression of cyclooxygenase-2 in the ventral CA₁ of the hippocampus.

    PubMed

    Sood, Rapita; Ritov, Gilad; Boltyansky, Boris; Spector-Chotiner, Almog; Richter-Levin, Gal; Barki-Harrington, Liza

    2014-11-01

    The pro-inflammatory enzyme cyclooxygenase-2 (COX-2) is regularly expressed in the hippocampal neurons, but its role in emotional trauma is not known. Here we show that a single acute stress caused by a near-drowning experience results in heightened anxiety-like behavior one month after the trauma. Biochemical analyses of dorsal and ventral hippocampal CA1, CA3 and dentate gyrus revealed decreased ubiquitination and elevated levels of COX-2 in the traumatized animals only in the ventral CA1. To reveal the identity of the ubiquitin E3 ligase that targets COX-2, we tested the effect of several representative E3 ligases on COX-2 expression in vitro. We found that while AIP4 and Nedd4 had no effect, Mdm2 lowered COX-2 expression by nearly 50%, an effect that was not observed by its dominant negative form. To test whether this also occurs in the hippocampus, we immunoprecipitated Mdm2 from dorsal and ventral CA1 of traumatized and control animals and probed for the presence of COX-2. Our results showed that the levels of Mdm2 were not affected by the trauma but there was significantly less COX-2 associated with Mdm2 in the ventral but not dorsal CA1 of the traumatized animals. Together these data propose that an increase in COX-2 expression in ventral CA1 following trauma is likely due to its attenuated degradation. Unraveling the pathways and mechanisms that control hippocampal COX-2 degradation is important to boost the development of novel therapeutic approaches designed to treat stress-related pathologies.

  13. Cervical changes in estrogen receptor alpha, oxytocin receptor, LH receptor, and cyclooxygenase-2 depending on the histologic compartment, longitudinal axis, and day of the ovine estrous cycle.

    PubMed

    Rodríguez-Piñón, M; Gonzalez, R; Tasende, C; Bielli, A; Genovese, P; Garófalo, E G

    2014-04-01

    The aim was to investigate the histologic distribution of estrogen receptor α (ERα), oxytocin receptor (OxR), LH receptor (LHR), and cyclooxygenase-2 (COX-2) in the cervix of the ewe during the estrous cycle. Immunohistochemistry was performed in the cranial and caudal cervix of Corriedale ewes on Day 1 (n = 6), 6 (n = 5), or 13 (n = 6) after estrous detection (Day 0). The ERα proportional score (%ERα nuclei) was lower in the cranial cervix than in the caudal cervix, whereas the OxR and COX-2 immunostaining areas (%areas) were greater in the cranial cervix than in the caudal cervix (P < 0.04). The %ERα nuclei decreased from Days 1 to 13 in luminal epithelia, but increased from Days 1 to 6 or remained unchanged in stromata (P < 0.003). The %OxR area was higher on Day 6 than on Days 1 and 13 in the superficial glandular epithelium, and increased from Days 1 to 13 in the deep glandular epithelium (P < 0.04). The %LHR area increased during the estrous cycle in luminal epithelia and fold stroma (P < 0.004). The %COX-2 area was restricted to epithelia, and it was lower on Day 1 than on Days 6 and 13 in luminal epithelia (P < 0.05). Differences in ERα, OxR, LHR, and COX-2 between cranial and caudal cervical zones indicate different physiological functions, and their cyclic variations in the cervical epithelia, in contrast to little or no variations in the stroma, suggest a hormone-responsive driving role of epithelia in cervical function. PMID:24485556

  14. Inhibition of IκB kinase (IKK) protects against peripheral nerve dysfunction of experimental diabetes.

    PubMed

    Negi, Geeta; Sharma, Shyam S

    2015-04-01

    Nuclear factor-κB (NF-κB) has been reported as a critical component of signalling mechanisms involved in the pathogenesis of a number of inflammatory conditions. Previous reports have shown that anti-inflammatory agents have a protective role in experimental diabetic neuropathy. Here, we assessed whether the inhibition of NF-κB cascade via IκB kinase (IKK) exerts any neuroprotective effect in experimental diabetic neuropathy. IKK inhibitor SC-514 (1 and 3 mg/kg) was administered daily for 2 weeks starting after 6 weeks of streptozotocin-induced diabetes. Nerve conduction and blood flow were determined by Powerlab and LASER Doppler system, respectively. We evaluated the changes in NF-κB, iNOS, and COX-2 expression by Western blotting in sciatic nerve. We found that IKK inhibition with SC-514 increased nerve blood flow and conduction velocity and improved pain threshold in diabetic animals. SC-514 also reduced the expression of NF-κB and phosphorylation of IKKβ in the sciatic nerve. Treatment with SC-514 reduced the elevated levels of pro-inflammatory cytokines (TNF-α and IL-6), iNOS, and COX-2. SC-514 reduces the expression of NF-κB and its downstream inflammatory components which may be involved in the improvement in nerve functions and pain perception in diabetic neuropathy. From the data of the present study, we suggest that diminution in IKK can be exploited as a drug target to significantly reduce the development of long-term complications of diabetes, particularly neuropathy. PMID:24946751

  15. Melanin Protects Paracoccidioides brasiliensis from the Effects of Antimicrobial Photodynamic Inhibition and Antifungal Drugs

    PubMed Central

    Baltazar, Ludmila Matos; Werneck, Silvia Maria Cordeiro; Soares, Betânia Maria; Ferreira, Marcus Vinicius L.; Souza, Danielle G.; Pinotti, Marcos; Santos, Daniel Assis

    2015-01-01

    Paracoccidioidomycosis (PCM) is a public health concern in Latin America and South America that when not correctly treated can lead to patient death. In this study, the influence of melanin produced by Paracoccidioides spp. on the effects of treatment with antimicrobial photodynamic inhibition (aPI) and antifungal drugs was evaluated. aPI was performed using toluidine blue (TBO) as a photosensitizer and a 630-nm light-emitting diode (LED) light. The antifungals tested were itraconazole and amphotericin B. We evaluated the effects of each approach, aPI or antifungals, against nonmelanized and melanized yeast cells by performing susceptibility tests and by quantifying oxidative and nitrosative bursts during the experiments. aPI reduced nonmelanized cells by 3.0 log units and melanized cells by 1.3 log units. The results showed that melanization protects the fungal cell, probably by acting as a scavenger of nitric oxide and reactive oxygen species, but not of peroxynitrite. Melanin also increased the MICs of itraconazole and amphotericin B, and the drugs were fungicidal for nonmelanized and fungistatic for melanized yeast cells. Our study shows that melanin production by Paracoccidioides yeast cells serves a protective function during aPI and treatment with itraconazole and amphotericin B. The results suggest that melanin binds to the drugs, changing their antifungal activities, and also acts as a scavenger of reactive oxygen species and nitric oxide, but not of peroxynitrite, indicating that peroxynitrite is the main radical that is responsible for fungal death after aPI. PMID:25896704

  16. Protection against Experimental Stroke by Ganglioside GM1 Is Associated with the Inhibition of Autophagy

    PubMed Central

    Li, Li; Tian, Jinghua; Long, Mitchell King-Wei; Chen, Yong; Lu, Jianfei; Zhou, Changman; Wang, Tianlong

    2016-01-01

    Ganglioside GM1, which is particularly abundant in the central nervous system (CNS), is closely associated with the protection against several CNS disorders. However, controversial findings have been reported on the role of GM1 following ischemic stroke. In the present study, using a rat middle cerebral artery occlusion (MCAO) model, we investigated whether GM1 can protect against ischemic brain injury and whether it targets the autophagy pathway. GM1 was delivered to Sprague-Dawley male rats at 3 doses (25 mg/kg, 50 mg/kg, 100 mg/kg) by intraperitoneal injection soon after reperfusion and then once daily for 2 days. The same volume of saline was given as a control. Tat–Beclin-1, a specific autophagy inducer, was administered by intraperitoneal injection at 24 and 48 hours post-MCAO. Infarction volume, mortality and neurological function were assessed at 72 hours after ischemic insult. Immunofluorescence and Western blotting were performed to determine the expression of autophagy-related proteins P62, LC3 and Beclin-1 in the penumbra area. No significant changes in mortality and physiological variables (heart rate, blood glucose levels and arterial blood gases) were observed between the different groups. However, MCAO resulted in enhanced conversion of LC3-I into LC3-II, P62 degradation, high levels of Beclin-1, a large area infarction (26.3±3.6%) and serious neurobehavioral deficits. GM1 (50 mg/kg) treatment significantly reduced the autophagy activation, neurobehavioral dysfunctions, and infarction volume (from 26.3% to 19.5%) without causing significant adverse side effects. However, this biological function could be abolished by Tat–Beclin-1. In conclusion: GM1 demonstrated safe and robust neuroprotective effects that are associated with the inhibition of autophagy following experimental stroke. PMID:26751695

  17. NPR3 protects cardiomyocytes from apoptosis through inhibition of cytosolic BRCA1 and TNF-α

    PubMed Central

    Lin, Dong; Chai, Yubo; Izadpanah, Reza; Braun, Stephen E.; Alt, Eckhard

    2016-01-01

    ABSTRACT Natriuretic peptide receptor 3 (NPR3) is a clearance receptor by binding and internalizing natriuretic peptides (NPs) for ultimate degradation. Patients with cardiac failure show elevated NPs. NPs are linked to poor long-term survival because of their apoptotic effects. However, the underling mechanisms have not been identified yet. Here we report the role of NPR3 in anti-apoptosis via the breast cancer type 1 susceptibility protein (BRCA1) and tumor necrosis factor α (TNF-α ). To demonstrate a role for NPR3 in apoptosis, stable H9C2 cardiomyocyte cell lines using shRNA to knockdown NPR3 were generated. The activities of caspase-3, 8, and 9 were significantly increased in NPR3 knockdown H9C2 cardiomyocytes. Knockdown of NPR3 increased the expression of BRCA1. Also NPR3 knockdown remarkably increased the activity of cAMP response element-binding protein (CREB), a positive regulatory element for BRCA1 expression. BRCA1 showed dispersed nuclear localization in non-cardiomyocytes while predominantly cytoplasmic localization in H9C2 cells. Meanwhile, NPR3 knockdown significantly increased TNF-α gene expression. These data show that NPR3 knockdown in H9C2 cells triggered both extrinsic and intrinsic apoptotic pathways. NPR3 protects cardiomyocytes from apoptosis through inhibition of cytosolic BRCA1 and TNF-α, which are regulators of apoptosis. Our studies demonstrate anti-apoptosis role of NPR3 in protecting cardiomyocytes and establish the first molecular link between NP system and programmed cell death. PMID:27494651

  18. Hemagglutination inhibiting antibodies and protection against seasonal and pandemic influenza infection

    PubMed Central

    Fox, Annette; Mai, Le Quynh; Thanh, Le Thi; Wolbers, Marcel; Le Khanh Hang, Nguyen; Thai, Pham Quang; Thu Yen, Nguyen Thi; Minh Hoa, Le Nguyen; Bryant, Juliet E.; Duong, Tran Nhu; Thoang, Dang Dinh; Barr, Ian G.; Wertheim, Heiman; Farrar, Jeremy; Hien, Nguyen Tran; Horby, Peter

    2015-01-01

    Summary Objectives Hemagglutination inhibiting (HI) antibodies correlate with influenza vaccine protection but their association with protection induced by natural infection has received less attention and was studied here. Methods 940 people from 270 unvaccinated households participated in active ILI surveillance spanning 3 influenza seasons. At least 494 provided paired blood samples spanning each season. Influenza infection was confirmed by RT-PCR on nose/throat swabs or serum HI assay conversion. Results Pre-season homologous HI titer was associated with a significantly reduced risk of infection for H3N2 (OR 0.61, 95%CI 0.44–0.84) and B (0.65, 95%CI 0.54–0.80) strains, but not H1N1 strains, whether re-circulated (OR 0.90, 95%CI 0.71–1.15), new seasonal (OR 0.86, 95%CI 0.54–1.36) or pandemic H1N1-2009 (OR 0.77, 95%CI 0.40–1.49). The risk of seasonal and pandemic H1N1 decreased with increasing age (both p < 0.0001), and the risk of pandemic H1N1 decreased with prior seasonal H1N1 (OR 0.23, 95%CI 0.08–0.62) without inducing measurable A/California/04/2009-like titers. Conclusions While H1N1 immunity was apparent with increasing age and prior infection, the effect of pre-season HI titer was at best small, and weak for H1N1 compared to H3N2 and B. Antibodies targeting non-HI epitopes may have been more important mediators of infection-neutralizing immunity for H1N1 compared to other subtypes in this setting. PMID:25224643

  19. Calcium-activated butyrylcholinesterase in human skin protects acetylcholinesterase against suicide inhibition by neurotoxic organophosphates

    SciTech Connect

    Schallreuter, Karin U.; University of Bradford ). E-mail: K.Schallreuter@bradford.ac.uk; Gibbons, Nicholas C.J.; Elwary, Souna M.; Parkin, Susan M.; Wood, John M.

    2007-04-20

    The human epidermis holds an autocrine acetylcholine production and degradation including functioning membrane integrated and cytosolic butyrylcholinesterase (BuchE). Here we show that BuchE activities increase 9-fold in the presence of calcium (0.5 x 10{sup -3}M) via a specific EF-hand calcium binding site, whereas acetylcholinesterase (AchE) is not affected. {sup 45}Calcium labelling and computer simulation confirmed the presence of one EF-hand binding site per subunit which is disrupted by H{sub 2}O{sub 2}-mediated oxidation. Moreover, we confirmed the faster hydrolysis by calcium-activated BuchE using the neurotoxic organophosphate O-ethyl-O-(4-nitrophenyl)-phenylphosphonothioate (EPN). Considering the large size of the human skin with 1.8 m{sup 2} surface area with its calcium gradient in the 10{sup -3}M range, our results implicate calcium-activated BuchE as a major protective mechanism against suicide inhibition of AchE by organophosphates in this non-neuronal tissue.

  20. Ephedrine hydrochloride protects mice from LPS challenge by promoting IL-10 secretion and inhibiting proinflammatory cytokines.

    PubMed

    Zheng, Yuejuan; Guo, Ziyi; He, Weigang; Yang, Yang; Li, Yuhu; Zheng, Aoxiang; Li, Ping; Zhang, Yan; Ma, Jinzhu; Wen, Mingyue; Yang, Muyi; An, Huazhang; Ji, Guang; Yu, Yizhi

    2012-05-01

    Sepsis and its derivative endotoxic shock are still serious conditions with high mortality in the intensive care unit. The mechanisms that ensure the balance of proinflammatory cytokines and anti-inflammatory cytokine production are of particular importance. As an active α- and β-adrenergic agonist, ephedrine hydrochloride (EH) is a widely used agent for cardiovascular diseases, especially boosting blood pressure. Here we demonstrate that EH increased Toll-like receptor 4 (TLR4)-mediated production of interleukin 10 (IL-10) through p38 MAPK activation. Simultaneously, EH negatively regulated the production of proinflammatory cytokines. Consistently, EH increased lipopolysaccharide (LPS)-induced serum IL-10 and inhibited tumor necrotic factor-α (TNFα) production in vivo. As a result, EH treatment protected mice from endotoxic shock by lethal LPS challenge. In brief, our data demonstrated that EH could contribute to immune homeostasis by balancing the production of proinflammatory cytokines and anti-inflammatory cytokine in TLR4 signaling. This study provides a potential usage of EH in autoimmunologic diseases or other severe inflammations.

  1. Protective effects of genetic inhibition of Discoidin Domain Receptor 1 in experimental renal disease

    PubMed Central

    Kerroch, Monique; Alfieri, Carlo; Dorison, Aude; Boffa, Jean-Jacques; Chatziantoniou, Christos; Dussaule, Jean-Claude

    2016-01-01

    Chronic kidney disease is a progressive incurable pathology affecting millions of people. Intensive investigations aim to identify targets for therapy. We have previously demonstrated that abnormal expression of the Discoidin Domain Receptor 1 (DDR1) is a key factor of renal disease by promoting inflammation and fibrosis. The present study investigates whether blocking the expression of DDR1 after the initiation of renal disease can delay or arrest the progression of this pathology. Severe renal disease was induced by either injecting nephrotoxic serum (NTS) or performing unilateral ureteral obstruction in mice, and the expression of DDR1 was inhibited by administering antisense oligodeoxynucleotides either at 4 or 8 days after NTS (corresponding to early or more established phases of disease, respectively), or at day 2 after ligation. DDR1 antisense administration at day 4 stopped the increase of proteinuria and protected animals against the progression of glomeruloneprhitis, as evidenced by functional, structural and cellular indexes. Antisense administration at day 8 delayed progression –but to a smaller degree- of renal disease. Similar beneficial effects on renal structure and inflammation were observed with the antisense administration of DDR1 after ureteral ligation. Thus, targeting DDR1 can be a promising strategy in the treatment of chronic kidney disease. PMID:26880216

  2. KATP channel blocker does not abolish the protective effect of NHE1 inhibition against ischaemia/reperfusion in aged myocardium

    PubMed Central

    Liu, Hong; Moore, Peter G

    2010-01-01

    Background and objective Aging is associated with an increase in myocardial susceptibility to ischaemia/reperfusion (I/R) injury. Na+/H+ exchange (NHE) inhibition and anaesthetic preconditioning (APC) are shown to protect myocardium from I/R injury. We set out to investigate if NHE inhibition can induce protection against I/R injury and whether KATP channel inhibition can enhance this effect in aged rat myocardium. Methods Hearts from 24-month old rats were assigned to 4 groups: (1) Control group; (2) APC group perfused with 2.5% sevoflurane before ischemia; (3) HOE group perfused with (3-methylsulfonyl-4-piperidinobenzoyl) guanidine methanesulfonate (HOE-694) prior to ischaemia; (4) HOE+5HD group perfused with both HOE and 5-hydroxydecanoic acid before ischaemia. We measured intracellular Na+ and Ca++ to quantitate the severity of myocardial injury. Results Both intracellular Na+ and Ca++ were significantly increased at the end of ischaemia and both were attenuated by NHE inhibition. Intracellular Na+ was 134±12 mEq/kg/dry weight in control group and 55±7 in HOE group (p<0.05). Intracellular Ca++ was 1764±142 nM in control group and 694±213 in HOE group (p<0.05). Infarct size was measured at 28±4% in control group vs. 17±2% in HOE group (p<0.05). High-energy phosphates and myocardial function were better preserved in HOE group compared to control (p<0.05). The beneficial effects of HOE on myocardial preservation was not blocked by 5HD nor were there any differences between APC and control groups. Conclusions NHE inhibition was effective in protecting myocardium from I/R injury in aged rats whereas APC was not. 5HD failed to block the protective effect of NHE inhibition. PMID:20216068

  3. Cox-2 Inhibition Protects against Hypoxia/Reoxygenation-Induced Cardiomyocyte Apoptosis via Akt-Dependent Enhancement of iNOS Expression

    PubMed Central

    Cai, Yin; Tang, Eva Hoi Ching; Yan, Dan; Kosuru, Ramoji

    2016-01-01

    The present study explored the potential causal link between ischemia-driven cyclooxygenase-2 (COX-2) expression and enhanced apoptosis during myocardial ischemia/reperfusion (I/R) by using H9C2 cardiomyocytes and primary rat cardiomyocytes subjected to hypoxia/reoxygenation (H/R). The results showed that H/R resulted in higher COX-2 expression than that of controls, which was prevented by pretreatment with Helenalin (NFκB specific inhibitor). Furthermore, pretreatment with NS398 (COX-2 specific inhibitor) significantly attenuated H/R-induced cell injury [lower lactate dehydrogenase (LDH) leakage and enhanced cell viability] and apoptosis (higher Bcl2 expression and lower level of cleaved caspases-3 and TUNEL-positive cells) in cardiomyocytes. The amelioration of posthypoxic apoptotic cell death was paralleled by significant attenuation of H/R-induced increases in proinflammatory cytokines [interleukin 6 (IL6) and tumor necrosis factor (TNFα)] and reactive oxygen species (ROS) production and by higher protein expression of phosphorylated Akt and inducible nitric oxide synthase (iNOS) and enhanced nitric oxide production. Moreover, the application of LY294002 (Akt-specific inhibitor) or 1400W (iNOS-selective inhibitor) cancelled the cellular protective effects of NS398. Findings from the current study suggest that activation of NFκB during cardiomyocyte H/R induces the expression of COX-2 and that higher COX-2 expression during H/R exacerbates cardiomyocyte H/R injury via mechanisms that involve cross talks among inflammation, ROS, and Akt/iNOS/NO signaling. PMID:27795807

  4. Pharmacological Inhibition of Myostatin Protects Against Atrophy and Weakness after ACL Tear

    PubMed Central

    Wolfe, Caroline Nicole; Gumucio, Jonathan P.; Grekin, Jeremy; Khouri, Roger Karl; Bedi, Asheesh; Mendias, Christopher

    2016-01-01

    decreases in the expression of these genes at 7D (Figure 1A). Additionally, IGF-1Ea and IGF-1Eb which are important growth factors that induce muscle protein synthesis, were elevated in the myostatin antibody groups at the 21D time point. For genes related to fibrosis (Figure 1B), although there was no significant difference in MMP-2, there was a significant decrease of MMP-8 expression in the 21D MSTN group when compared to the 21D sham. There were also increases in the expression of TIMP-1 and 2 in the 21D MSTN group. Conclusion: In a preclinical rat model, the targeted inhibition of myostatin protected leg muscles from muscle atrophy and improved force production after ACL tear. While the mechanism of action is not entirely clear, it is possible that the inhibition of myostatin preserves strength by limiting the expression of proteolytic enzymes in the post-acute atrophy phase and increasing protein synthesis in later phases.

  5. Expression of Cyclooxygenase-2 and Transforming Growth Factor-beta1 in HCV-Induced Chronic Liver Disease and Hepatocellular Carcinoma

    PubMed Central

    El-Bassiouny, Azza E.I.; Zoheiry, Mona M.K.; Nosseir, Mona M.F.; El-Ahwany, Eman G.; Ibrahim, Raafat A.; El-Bassiouni, Nora E.I.

    2007-01-01

    Cyclooxygenase-2 (COX-2) and transforming growth factor-beta1 (TGF-beta1) were modulated in a variety of viral infections, but there is a paucity of data about their role in the pathologic process of cirrhosis and/or hepatocellular carcinoma (HCC) following chronic hepatitis C virus (HCV) infection. The material of the current study included 50 cases of chronic hepatitis C (CHC) without cirrhosis, 30 cases of CHC with cirrhosis, and 30 cases of HCC with HCV admitted to the Gastroenterology and Hepatology Department of Theodor Bilharz Research Institute, Giza, Egypt. Fifteen wedge liver biopsies, taken during laparoscopic cholecystectomy, were included in the study as normal controls. Laboratory investigations, serologic markers for viral hepatitis, and serum alpha fetoprotein levels (alpha-FP) were done for all cases of the study. Immunohistochemistry using primary antibodies against both factors revealed weak to faint immunoreactivity to COX-2 and TGF-beta1 in normal hepatic tissue (< 30% and < 50% of the cells, respectively). COX-2 expression was upregulated in patients with CHC with and without cirrhosis, yet 80% of positively stained cirrhotic cases showed marked staining intensity. Higher COX-2 expression was observed in well-differentiated HCC cases (80%) with marked staining intensity (75%) compared with advanced HCC tumors (P < .001). TGF-beta1 was expressed in the hepatocytes of all cases of CHC with and without cirrhosis as well as in 67% of HCC cases. Extensive cytoplasmic expression was detected in 52%, 93.3%, and 46.6% of CHC patients without cirrhosis, patients with cirrhosis, and patients with HCC, respectively. A positive correlation was observed between hepatic expression of COX-2 and TGF-beta1 (r = 0.67, P < .05); however, no correlation was detected between the latter and grade of HCC differentiation (r = 0.33, P > .05). Conclusion These findings may suggest that TGF-beta1 plays a role in hepatic cell damage following HCV infection thus stressing

  6. Opioid-sparing effect of selective cyclooxygenase-2 inhibitors on surgical outcomes after open colorectal surgery within an enhanced recovery after surgery protocol

    PubMed Central

    Lohsiriwat, Varut

    2016-01-01

    AIM: To evaluate the opioid-sparing effect of selective cyclooxygenase-2 (COX-2) inhibitors on short-term surgical outcomes after open colorectal surgery. METHODS: Patients undergoing open colorectal resection within an enhanced recovery after surgery protocol from 2011 to 2015 were reviewed. Patients with combined general anesthesia and epidural anesthesia, and those with acute colonic obstruction or perforation were excluded. Patients receiving selective COX-2 inhibitor were compared with well-matched individuals without such a drug. Outcome measures included numeric pain score and morphine milligram equivalent (MME) consumption on postoperative day (POD) 1-3, gastrointestinal recovery (time to tolerate solid diet and time to defecate), complications and length of postoperative stay. RESULTS: There were 75 patients in each group. Pain score on POD 1-3 was not significantly different between two groups. However, MME consumption and MME consumption per kilogram body weight on POD 1-3 was significantly less in patients receiving a selective COX-2 inhibitor (P < 0.001). Median MME consumption per kilogram body weight on POD 1-3 was 0.09, 0.06 and nil, respectively in patients receiving a selective COX-2 inhibitor and 0.22, 0.25 and 0.07, respectively in the comparative group (P < 0.001), representing at least 59% opioid reduction. Patients prescribing a selective COX-2 inhibitor had a shorter median time to resumption of solid diet [1 (IQR 1-2) d vs 2 (IQR 2-3) d; P < 0.001] and time to first defecation [2 (IQR 2-3) d vs 3 (IQR 3-4) d; P < 0.001]. There was no significant difference in overall postoperative complications between two groups. However, median postoperative stay was significantly 1-d shorter in patients prescribing a selective COX-2 inhibitor [4 (IQR 3-5) d vs 5 (IQR 4-6) d; P < 0.001]. CONCLUSION: Perioperative administration of oral selective COX-2 inhibitors significantly decreased intravenous opioid consumption, shortened time to gastrointestinal

  7. 2,2',4,4'-Tetrachlorobiphenyl upregulates cyclooxygenase-2 in HL-60 cells via p38 mitogen-activated protein kinase and NF-{kappa}B

    SciTech Connect

    Bezdecny, Steven A.; Karmaus, Peer; Roth, Robert A.; Ganey, Patricia E. . E-mail: ganey@msu.edu

    2007-06-15

    Polychlorinated biphenyls (PCBs) are ubiquitous, persistent environmental contaminants that affect a number of cellular systems, including neutrophils. Among the effects caused by the noncoplanar PCB 2,2',4,4'-tetrachlorobiphenyl (2244-TCB) in granulocytic HL-60 cells are increases in superoxide anion production, activation of phospholipase A{sub 2} with subsequent release of arachidonic acid (AA) and upregulation of the inflammatory gene cyclooxygenase-2 (COX-2). The objective of this study was to determine the signal transduction pathways involved in the upregulation of COX-2 by 2244-TCB. Treatment of HL-60 cells with 2244-TCB led to increased expression of COX-2 mRNA. This increase was prevented by the transcriptional inhibitor actinomycin D in cells pretreated with 2244-TCB for 10 min. The increase in COX-2 mRNA was associated with release of {sup 3}H-AA, phosphorylation of p38 and extracellular signal-regulated kinase (ERK) mitogen-activated protein (MAP) kinases, increased levels of nuclear NF-{kappa}B and increased superoxide anion production. Bromoenol lactone, an inhibitor of the calcium-independent phospholipase A{sub 2}, reduced {sup 3}H-AA release but had no effect on COX-2 mRNA, protein or activity. Pretreatment with SB-202190 or SB-203580, inhibitors of the p38 MAP kinase pathway, prevented the 2244-TCB-mediated induction of COX-2 and phosphorylation of p38 and ERK MAP kinases. These inhibitors did not alter {sup 3}H-AA release. Treatment with PD 98059 or U 0126, inhibitors of the MAP/ERK (MEK) pathway, prevented the 2244-TCB-mediated activation of ERK but had no effect on COX-2 induction or p38 phosphorylation. 2244-TCB treatment did not affect c-Jun N-terminal kinase (JNK) phosphorylation. 2244-TCB exposure increased the amount of nuclear NF-{kappa}B. This increase was prevented by pretreatment with p38 MAP kinase inhibitors, but not by pretreatment with MEK inhibitors. Pretreatment with inhibitors of NF-{kappa}B prevented the 2244-TCB

  8. Leptin deficiency-induced obesity exacerbates ultraviolet B radiation-induced cyclooxygenase-2 expression and cell survival signals in ultraviolet B-irradiated mouse skin

    SciTech Connect

    Sharma, Som D.; Katiyar, Santosh K.

    2010-05-01

    Obesity has been implicated in several inflammatory diseases and in different types of cancer. Chronic inflammation induced by exposure to ultraviolet (UV) radiation has been implicated in various skin diseases, including melanoma and nonmelanoma skin cancers. As the relationship between obesity and susceptibility to UV radiation-caused inflammation is not clearly understood, we assessed the role of obesity on UVB-induced inflammation, and mediators of this inflammatory response, using the genetically obese (leptin-deficient) mouse model. Leptin-deficient obese (ob/ob) mice and wild-type counterparts (C57/BL6 mice) were exposed to UVB radiation (120 mJ/cm{sup 2}) on alternate days for 1 month. The mice were then euthanized and skin samples collected for analysis of biomarkers of inflammatory responses using immunohistochemistry, western blotting, ELISA and real-time PCR. Here, we report that the levels of inflammatory responses were higher in the UVB-exposed skin of the ob/ob obese mice than those in the UVB-exposed skin of the wild-type non-obese mice. The levels of UVB-induced cyclooxygenase-2 expression, prostaglandin-E{sub 2} production, proinflammatory cytokines (i.e., tumor necrosis factor-alpha, interleukin-1beta, interleukin-6), and proliferating cell nuclear antigen and cell survival signals (phosphatidylinositol-3-kinase and p-Akt-Ser{sup 473}) were higher in the skin of the ob/ob obese mice than the those in skin of their wild-type non-obese counterparts. Compared with the wild-type non-obese mice, the leptin-deficient obese mice also exhibited greater activation of NF-kappaB/p65 and fewer apoptotic cells in the UVB-irradiated skin. Our study suggests for the first time that obesity in mice is associated with greater susceptibility to UVB-induced inflammatory responses and, therefore, obesity may increase susceptibility to UVB-induced inflammation-associated skin diseases, including the risk of skin cancer.

  9. Regulation of tumorigenic Wnt signaling by cyclooxygenase-2, 5-lipoxygenase and their pharmacological inhibitors: A basis for novel drugs targeting cancer cells?

    PubMed

    Roos, Jessica; Grösch, Sabine; Werz, Oliver; Schröder, Peter; Ziegler, Slava; Fulda, Simone; Paulus, Patrick; Urbschat, Anja; Kühn, Benjamin; Maucher, Isabelle; Fettel, Jasmin; Vorup-Jensen, Thomas; Piesche, Matthias; Matrone, Carmela; Steinhilber, Dieter; Parnham, Michael J; Maier, Thorsten J

    2016-01-01

    Canonical Wnt signaling is a highly conserved pathway with a prominent role in embryogenic development, adult tissue homeostasis, cell polarization, stem cell biology, cell differentiation, and proliferation. Furthermore, canonical Wnt signaling is of pivotal importance in the pathogenesis of a number of cancer types and crucially affects tumor initiation, cancer cell proliferation, cancer cell apoptosis, and metastasis. Reports over the last decade have provided strong evidence for a pathophysiological role of Wnt signaling in non-malignant classical inflammatory and neurodegenerative diseases. Although, several agents suppressing the Wnt pathway at different levels have been identified, the development of clinically relevant Wnt-inhibiting agents remains challenging due to selectivity and toxicity issues. Several studies have shown that long-term administration of non-steroidal anti-inflammatory drugs protects against colon cancer and potentially other tumor types by interfering both with the COX and the Wnt pathway. Our own studies have shown that non-steroidal anti-inflammatory drugs suppress Wnt signaling by targeting the pro-inflammatory enzyme 5-lipoxygenase which is the key enzyme pathophysiologically involved in the synthesis of leukotrienes. Furthermore, we found a direct link between the 5-lipoxygenase and Wnt signaling pathways, which is essential for the maintenance of leukemic stem cells. Accordingly, genetic and pharmacological inhibition of 5-lipoxygenase led to an impairment of Wnt-dependent acute and chronic myeloid leukemic stem cells. We believe that 5-lipoxygenase inhibitors might represent a novel type of Wnt inhibitor activating a potentially naturally occurring novel mechanism of suppression of Wnt signaling that is non-toxic, at least in mice, and is potentially well tolerated in patients.

  10. Protection from hypertension in mice by the Mediterranean diet is mediated by nitro fatty acid inhibition of soluble epoxide hydrolase

    PubMed Central

    Charles, Rebecca L.; Rudyk, Olena; Prysyazhna, Oleksandra; Kamynina, Alisa; Yang, Jun; Morisseau, Christophe; Hammock, Bruce D.; Freeman, Bruce A.; Eaton, Philip

    2014-01-01

    Soluble epoxide hydrolase (sEH) is inhibited by electrophilic lipids by their adduction to Cys521 proximal to its catalytic center. This inhibition prevents hydrolysis of the enzymes’ epoxyeicosatrienoic acid (EET) substrates, so they accumulate inducing vasodilation to lower blood pressure (BP). We generated a Cys521Ser sEH redox-dead knockin (KI) mouse model that was resistant to this mode of inhibition. The electrophilic lipid 10-nitro-oleic acid (NO2-OA) inhibited hydrolase activity and also lowered BP in an angiotensin II-induced hypertension model in wild-type (WT) but not KI mice. Furthermore, EET/dihydroxy-epoxyeicosatrienoic acid isomer ratios were elevated in plasma from WT but not KI mice following NO2-OA treatment, consistent with the redox-dead mutant being resistant to inhibition by lipid electrophiles. sEH was inhibited in WT mice fed linoleic acid and nitrite, key constituents of the Mediterranean diet that elevates electrophilic nitro fatty acid levels, whereas KIs were unaffected. These observations reveal that lipid electrophiles such as NO2-OA mediate antihypertensive signaling actions by inhibiting sEH and suggest a mechanism accounting for protection from hypertension afforded by the Mediterranean diet. PMID:24843165

  11. Mechanism study of endothelial protection and inhibits platelet activation of low molecular weight fucoidan from Laminaria japonica

    NASA Astrophysics Data System (ADS)

    Chen, Anjin; Zhang, Fang; Shi, Jie; Zhao, Xue; Yan, Meixing

    2016-10-01

    Several studies have indicated that fucoidan fractions with low molecular weight and different sulfate content from Laminaria japonica could inhibit the activation of platelets directly by reducing the platelet aggregation. To explore the direct effect of LMW fucoidan on the platelet system furthermore and examine the possible mechanism, the endothelial protection and inhibits platelet activation effects of two LMW fucoidan were investigated. In the present study, Endothelial injury model of rats was made by injection of adrenaline (0.4 mg kg-1) and human umbilical vein endothelial cells were cultured. vWF level was be investigated in vivo and in vitro as an important index of endothelial injury. LMW fucoidan could significantly reduce vWF level in vascular endothelial injury rats and also significantly reduce vWF level in vitro. The number of EMPs was be detected as another important index of endothelial injury. The results showed that LMW fucoidan reduced EMPs stimulated by tumor necrosis factor. In this study, it was found that by inhibiting platelet adhesion, LMW fucoidan played a role in anti-thrombosis and the specific mechanism of action is to inhibit the flow of extracellular Ca2+. All in a word, LMW fucoidan could inhibit the activation of platelets indirectly by reducing the concentration of EMPs and vWF, at the same time; LMW fucoidan inhibited the activation of platelets directly by inhibiting the flow of extracellular Ca2+.

  12. Magnesium isoglycyrrhizinate inhibits inflammatory response through STAT3 pathway to protect remnant liver function

    PubMed Central

    Tang, Guang-Hua; Yang, Hua-Yu; Zhang, Jin-Chun; Ren, Jin-Jun; Sang, Xin-Ting; Lu, Xin; Zhong, Shou-Xian; Mao, Yi-Lei

    2015-01-01

    AIM: To investigate the protective effect of magnesium isoglycyrrhizinate (MgIG) on excessive hepatectomy animal model and its possible mechanism. METHODS: We used the standard 90% hepatectomy model in Sprague-Dawley rats developed using the modified Emond’s method, in which the left, middle, right upper, and right lower lobes of the liver were removed. Rats with 90% liver resection were divided into three groups, and were injected intraperitoneally with 3 mL saline (control group), 30 mg/kg (low-dose group) and 60 mg/kg (high-dose group) of MgIG, respectively. Animals were sacrificed at various time points and blood was drawn from the vena cava. Biochemical tests were performed with an automatic biochemical analyzer for the following items: serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutamyl endopeptidase, total bilirubin (TBil), direct bilirubin (DBil), total protein, albumin, blood glucose (Glu), hyper-sensitivity C-reactive protein, prothrombin time (PT), and thrombin time (TT). Postoperative survival time was observed hourly until death. Hepatocyte regeneration was analyzed by immunohistochemistry. Serum inflammatory cytokines (IL-1, IL-6, IL-10, and iNOS) was analyzed by ELISA. STAT3 protein and mRNA were analyzed by Western blot and quantitative reverse-transcription PCR, respectively. RESULTS: The high-dose group demonstrated a significantly prolonged survival time, compared with both the control and the low-dose groups (22.0 ± 4.7 h vs 8.9 ± 2.0 vs 10.3 ± 3.3 h, P = 0.018). There were significant differences among the groups in ALT, Glu and PT levels starting from 6 h after surgery. The ALT levels were significantly lower in the MgIG treated groups than in the control group. Both Glu and PT levels were significantly higher in the MgIG treated groups than in the control group. At 12 h, ALT, AST, TBil, DBil and TT levels showed significant differences between the MgIG treated groups and the control group. No significant

  13. CBLB502 administration protects gut mucosal tissue in ulcerative colitis by inhibiting inflammation

    PubMed Central

    Xu, Yang; Dong, Hongxia; Ge, Changhui; Gao, Yan; Liu, Haifeng

    2016-01-01

    Background Ulcerative colitis (UC) is a nonspecific inflammatory disease for which medications and therapeutic strategies have only been moderately successful. CBLB502, a toll-like receptor 5 (TLR5) agonist derived from Salmonella flagellin, exhibits anticancer and radioprotective activities via modulation of TLRs and the nuclear factor kappa B (NF-κB) signaling pathway and can protect against acute renal ischemic failure. In this study, we intend to examine the effects of CBLB502 on both TLR responses and the interleukin (IL) and NF-κB signaling pathways in UC treatment. Methods The UC mouse model was prepared in BALB/c mice by administering 2,4,6-trinitrobenzene sulfonic acid (TNBS). CBLB502 was used as the therapeutic drug. After CBLB502 therapy, the IL and tumor necrosis factor-α (TNF-α) levels were measured by ELISA. Total RNA and protein of colon samples was extracted. Results We found that CBLB502 had a distinctive therapeutic effect in the UC model. In control group animals, IL-10 expression in serum was 91.48±24.38 ng/mL; this was higher than in the model group (59.36±14.46 ng/mL, P<0.05) or the treatment group (54.29±5.83 ng/mL, P<0.05). In model group animals, the concentration of TNF-α in serum was 140.11±12.70 ng/mL, which was lower than protein levels in the control group (173.86±29.26 ng/mL, P<0.05). The mRNA levels of TLR1, 2, 3, 4, 6, 7, 8, and 9 in the CBLB502 treatment group were significantly lower than in the model group (P<0.05). Western blot revealed that CBLB502 also reduced NF-κB expression in the mouse colon, but that NF-κB expression was not significantly lower than the model group. Conclusions CBLB502 can reduce mucosal damage induced by TNBS and inhibit inflammation and TLR expression. The inhibition of UC by CBLB502 is strictly TLR-IL-dependent and is dose-dependent within the efficacious dose range. Therefore, our results suggested that CBLB502 might be a candidate drug for the treatment of UC.

  14. CBLB502 administration protects gut mucosal tissue in ulcerative colitis by inhibiting inflammation

    PubMed Central

    Xu, Yang; Dong, Hongxia; Ge, Changhui; Gao, Yan; Liu, Haifeng

    2016-01-01

    Background Ulcerative colitis (UC) is a nonspecific inflammatory disease for which medications and therapeutic strategies have only been moderately successful. CBLB502, a toll-like receptor 5 (TLR5) agonist derived from Salmonella flagellin, exhibits anticancer and radioprotective activities via modulation of TLRs and the nuclear factor kappa B (NF-κB) signaling pathway and can protect against acute renal ischemic failure. In this study, we intend to examine the effects of CBLB502 on both TLR responses and the interleukin (IL) and NF-κB signaling pathways in UC treatment. Methods The UC mouse model was prepared in BALB/c mice by administering 2,4,6-trinitrobenzene sulfonic acid (TNBS). CBLB502 was used as the therapeutic drug. After CBLB502 therapy, the IL and tumor necrosis factor-α (TNF-α) levels were measured by ELISA. Total RNA and protein of colon samples was extracted. Results We found that CBLB502 had a distinctive therapeutic effect in the UC model. In control group animals, IL-10 expression in serum was 91.48±24.38 ng/mL; this was higher than in the model group (59.36±14.46 ng/mL, P<0.05) or the treatment group (54.29±5.83 ng/mL, P<0.05). In model group animals, the concentration of TNF-α in serum was 140.11±12.70 ng/mL, which was lower than protein levels in the control group (173.86±29.26 ng/mL, P<0.05). The mRNA levels of TLR1, 2, 3, 4, 6, 7, 8, and 9 in the CBLB502 treatment group were significantly lower than in the model group (P<0.05). Western blot revealed that CBLB502 also reduced NF-κB expression in the mouse colon, but that NF-κB expression was not significantly lower than the model group. Conclusions CBLB502 can reduce mucosal damage induced by TNBS and inhibit inflammation and TLR expression. The inhibition of UC by CBLB502 is strictly TLR-IL-dependent and is dose-dependent within the efficacious dose range. Therefore, our results suggested that CBLB502 might be a candidate drug for the treatment of UC. PMID:27668221

  15. Inhibition of the NMDA receptor protects the rat sciatic nerve against ischemia/reperfusion injury

    PubMed Central

    KE, TIE; LI, RENBIN; CHEN, WENCHANG

    2016-01-01

    Inhibition of the N-methyl-D-aspartate (NMDA) receptor by MK-801 reduces ischemia/reperfusion (I/R) injury in the central nervous system. However, few previous studies have evaluated the neuroprotective effects of MK-801 against peripheral I/R injury. The present study aimed to investigate the protective effects of MK-801 pretreatment against I/R injury in the rat sciatic nerve (SN). Sprague-Dawley rats were subjected to a sham surgery (n=8) or to a 5-h ischemic insult by femoral artery clamping (I/R and I/R+MK-801 groups; n=48 per group). I/R+MK-801 rats were intraperitoneally injected with MK-801 (0.5 ml or 1 mg/kg) at 15 min prior to reperfusion. The rats were sacrificed at 0, 6, 12, 24, 72 h, or 7 days following reperfusion. Plasma malondialdehyde (MDA) and nitric oxide (NO) concentrations, and SN inducible NO synthase (iNOS) protein expression levels, were measured using colorimetry. In addition, the protein expression levels of tumor necrosis factor-α (TNF-α) were measured using immunohistochemistry, and histological analyses of the rat SN were conducted using light and electron microscopy. Alterations in the mRNA expression levels of TNF-α and TNF-α converting enzyme (TACE) in the rat SN were detected using reverse transcription-quantitative polymerase chain reaction. In the I/R group, plasma concentrations of NO (175.3±4.2 µmol/l) and MDA (16.2±1.9 mmol/l), and the levels of iNOS (2.5±0.3) in the SN, peaked at 24 h post-reperfusion. At 24 h, pretreatment with MK-801 significantly reduced plasma NO (107.3±3.6 µmol/l) and MDA (11.8±1.6 mmol/l), and SN iNOS (1.65±0.2) levels (all P<0.01). The mRNA expression levels of TNF-α and TACE in the SN were significantly reduced in the I/R+MK-801 group, as compared with the I/R group (P<0.05). Furthermore, MK-801 pretreatment was shown to have alleviated histological signs of I/R injury, including immune cell infiltration and axon demyelination. The results of the present study suggested that pretreatment

  16. Taurine protects against methotrexate-induced toxicity and inhibits leukocyte death

    SciTech Connect

    Cetiner, Mustafa; Sener, Goeksel; Sehirli, A. Ozer; Eksioglu-Demiralp, Emel; Ercan, Feriha; Sirvanci, Serap; Gedik, Nursal; Akpulat, Sertac; Tecimer, Tuelay; Yegen, Berrak C. . E-mail: byegen@marmara.edu.tr

    2005-11-15

    The efficacy of methotrexate (MTX), a widely used cytotoxic chemotherapeutic agent, is often limited by severe side effects and toxic sequelae. Regarding the mechanisms of these side effects, several hypotheses have been put forward, among which oxidative stress is noticeable. The present study was undertaken to determine whether taurine, a potent free radical scavenger, could ameliorate MTX-induced oxidative injury and modulate immune response. Following a single dose of methotrexate (20 mg/kg), either saline or taurine (50 mg/kg) was administered for 5 days. After decapitation of the rats, trunk blood was obtained and the ileum, liver, and kidney were removed to measure malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity, and collagen content, as well as histological examination. Our results showed that MTX administration increased the MDA, MPO activity, and collagen contents and decreased GSH levels in all tissues (P < 0.001), while these alterations were reversed in taurine-treated group (P < 0.05-0.01). Elevated (P < 0.001) TNF-{alpha} level observed following MTX treatment was depressed with taurine (P < 0.01). Oxidative burst of neutrophils stimulated by phorbol myristate acetate was reduced in saline-treated MTX group (P < 0.001), while taurine abolished this effect. Similarly, flow cytometric measurements revealed that leukocyte apoptosis and cell death were increased in MTX-treated animals, while taurine reversed these effects (P < 0.05). Reduced cellularity in bone marrow samples of MTX-treated group (P < 0.01) was reversed back to control levels in taurine-treated rats. Severe degeneration of the intestinal mucosa, liver parenchyma, glomerular, and tubular epithelium observed in saline-treated group was improved by taurine treatment. In conclusion, it appears that taurine protects against methotrexate-induced oxidant organ injury and inhibits leukocyte apoptosis and may be of therapeutic potential in alleviating the

  17. Use of dietary rosemary diterpenes to inhibit rancid volatiles in lamb meat packed under protective atmosphere.

    PubMed

    Ortuño, J; Serrano, R; Bañón, S

    2016-08-01

    The objective of the present study was to determine the inhibitory effect of dietary rosemary diterpenes on the formation of the volatile organic compounds (VOCs) responsible for rancid flavour in raw lamb meat. The lamb diet was supplemented during the fattening stage with two levels (200 and 400 mg/kg feed) of a dietary rosemary extract (DRE) containing carnosic acid and carnosol (1 : 1, w/w). The formation of VOCs (determined by headspace solid-phase microextraction at 40°C and MS) and odour deterioration (assessed by quantitative descriptive analysis) were monitored in meat fillets (longissimus dorsi-lumborum muscle) packed in a 70/30 O2/CO2 protective atmosphere and kept at 2°C for up to 14 days. The raw meat odour deteriorated under pro-oxidizing conditions due to the development of an incipient rancidity caused by the formation of volatiles from lipid oxidation. A total of 46 volatile compounds were determined in lamb headspace: 18 aldehydes, seven alcohols, seven organic acids, six ketones, four furan compounds, two benzene compounds, one ester and one terpenoid. The use of DRE contributed to inhibit VOC formation and rancidity. Heptanal, octanal, nonanal and 2-pentyl-furan were the only VOCs affected (P0.75; P<0.001), although similar values were obtained for the coefficients of a large number of carbonyl, alcohols and furan compounds, among other volatiles, which can be considered molecular markers of rancidity in raw lamb meat. Principal component analysis confirmed that the differences in the VOC profile make it possible to identify whether or not samples have been reinforced with dietary rosemary diterpenes. Thus, VOC profiling can be regarded as a useful tool for assessing the dietary treatments used in sheep to improve the oxidative stability of lamb meat.

  18. Use of dietary rosemary diterpenes to inhibit rancid volatiles in lamb meat packed under protective atmosphere.

    PubMed

    Ortuño, J; Serrano, R; Bañón, S

    2016-08-01

    The objective of the present study was to determine the inhibitory effect of dietary rosemary diterpenes on the formation of the volatile organic compounds (VOCs) responsible for rancid flavour in raw lamb meat. The lamb diet was supplemented during the fattening stage with two levels (200 and 400 mg/kg feed) of a dietary rosemary extract (DRE) containing carnosic acid and carnosol (1 : 1, w/w). The formation of VOCs (determined by headspace solid-phase microextraction at 40°C and MS) and odour deterioration (assessed by quantitative descriptive analysis) were monitored in meat fillets (longissimus dorsi-lumborum muscle) packed in a 70/30 O2/CO2 protective atmosphere and kept at 2°C for up to 14 days. The raw meat odour deteriorated under pro-oxidizing conditions due to the development of an incipient rancidity caused by the formation of volatiles from lipid oxidation. A total of 46 volatile compounds were determined in lamb headspace: 18 aldehydes, seven alcohols, seven organic acids, six ketones, four furan compounds, two benzene compounds, one ester and one terpenoid. The use of DRE contributed to inhibit VOC formation and rancidity. Heptanal, octanal, nonanal and 2-pentyl-furan were the only VOCs affected (P0.75; P<0.001), although similar values were obtained for the coefficients of a large number of carbonyl, alcohols and furan compounds, among other volatiles, which can be considered molecular markers of rancidity in raw lamb meat. Principal component analysis confirmed that the differences in the VOC profile make it possible to identify whether or not samples have been reinforced with dietary rosemary diterpenes. Thus, VOC profiling can be regarded as a useful tool for assessing the dietary treatments used in sheep to improve the oxidative stability of lamb meat. PMID:26940773

  19. Mild Hypothermia Protects Pigs’ Gastric Mucosa After Cardiopulmonary Resuscitation via Inhibiting Interleukin 6 (IL-6) Production

    PubMed Central

    Wang, Yan; Song, Jian; Liu, Yuhong; Li, Yaqiang; Liu, Zhengxin

    2016-01-01

    Background The purpose of this study was to determine the effect of mild hypothermia therapy on gastric mucosa after cardiopulmonary resuscitation (CPR) and the underlying mechanism. Material/Methods Ventricular fibrillation was induced in pigs. After CPR, the surviving pigs were divided into mild hypothermia-treated and control groups. The changes in vital signs and hemodynamic parameters were monitored before cardiac arrest and at intervals of 0.5, 1, 2, 4, 6, 12, and 24 h after restoration of spontaneous circulation. Serum IL-6 was determined at the same time, and gastroscopy was performed. The pathologic changes were noted, and the expression of IL-6 was determined by hematoxylin and eosin (HE) staining and immunohistochemistry under light. Results The heart rate, mean arterial blood pressure, and cardiac output in both groups did not differ significantly. The gastric mucosa ulcer index evaluated by gastroscopy 2 h and 24 h after restoration of spontaneous circulation (ROSC) in the mild hypothermic group was lower than that the control group (P<0.05). The inflammatory pathologic score of gastric mucosa in the mild hypothermic group 6–24 h after ROSC was lower than that in the control group (P<0.05). Serum and gastric mucosa IL-6 expression 0.5–4 h and 6, 12, and 24 h after ROSC was lower in the mild hypothermic group than in the control group (P<0.05). Conclusions Mild hypothermia treatment protects gastric mucosa after ROSC via inhibiting IL-6 production and relieving the inflammatory reaction. PMID:27694796

  20. Inhibition of Drp1 mitochondrial translocation provides neural protection in dopaminergic system in a Parkinson's disease model induced by MPTP.

    PubMed

    Filichia, Emily; Hoffer, Barry; Qi, Xin; Luo, Yu

    2016-01-01

    Accumulating evidence suggest mitochondria-mediated pathways play an important role in dopaminergic neuronal cell death in Parkinson's disease (PD). Drp1, a key regulator of mitochondrial fission, has been shown to be activated and translocated to mitochondria under stress, leading to excessive mitochondria fission and dopaminergic neuronal death in vitro. However, whether Drp1 inhibition can lead to long term stable preservation of dopaminergic neurons in PD-related mouse models remains unknown. In this study, using a classical MPTP animal PD model, we showed for the first time Drp1 activation and mitochondrial translocation in vivo after MPTP administration. Inhibition of Drp1 activation by a selective peptide inhibitor P110, blocked MPTP-induced Drp1 mitochondrial translocation and attenuated dopaminergic neuronal loss, dopaminergic nerve terminal damage and behavioral deficits caused by MPTP. MPTP-induced microglial activation and astrogliosis were not affected by P110 treatment. Instead, inhibition of Drp1 mitochondrial translocation diminished MPTP-induced p53, BAX and PUMA mitochondrial translocation. This study demonstrates that inhibition of Drp1 hyperactivation by a Drp1 peptide inhibitor P110 is neuroprotective in a MPTP animal model. Our data also suggest that the protective effects of P110 treatment might be mediated by inhibiting the p53 mediated apoptotic pathways in neurons through inhibition of Drp1-dependent p53 mitochondrial translocation. PMID:27619562

  1. Pterostilbene Is Equally Potent as Resveratrol in Inhibiting 12-O-tetradecanoylphorbol-13-acetate Activated NFkappaB, AP-1, COX-2 and iNOS in Mouse Epidermis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resveratrol, a phytoalexin present in grapes, has been reported to inhibit multistage mouse skin carcinogenesis. Recent studies showed that topically applied resveratrol significantly inhibited cyclooxygenase-2 (COX-2) expression and activation of nuclear factor-kB (NF-kB) induced by tumor promoter...

  2. Emodin-mediated protection from acute myocardial infarction via inhibition of inflammation and apoptosis in local ischemic myocardium.

    PubMed

    Wu, Yanxia; Tu, Xin; Lin, Guosheng; Xia, Hao; Huang, Hao; Wan, Jing; Cheng, Zhide; Liu, Mengyuan; Chen, Gao; Zhang, Haimou; Fu, Jinrong; Liu, Qian; Liu, Dong-Xu

    2007-10-13

    Acute myocardial infarction (AMI) is associated with inflammation and apoptosis. Emodin plays an anti-inflammatory role in several inflammatory diseases. Recent studies have demonstrated that emodin protects against myocardial ischemia/reperfusion injury. However, its mechanism underlying its effects remains unknown. In a murine model of AMI, based on ligation of the left coronary artery, administration of emodin reduced myocardial infarct size (MIS) in a dose-dependent manner. Emodin significantly suppressed TNF-alpha expression and NF-kappaB activation in the local myocardial infarction area. Treatment with emodin inhibited myocardial cell apoptosis by inhibiting caspase-3 activation. Therefore, these studies demonstrate that emodin protects against myocardial cell injury via suppression of local inflammation and apoptosis.

  3. Protective Effect of Isorhamnetin on Lipopolysaccharide-Induced Acute Lung Injury in Mice.

    PubMed

    Yang, Bo; Li, Xiao-Ping; Ni, Yun-Feng; Du, Hong-Yin; Wang, Rong; Li, Ming-Jiang; Wang, Wen-Chen; Li, Ming-Ming; Wang, Xu-Hui; Li, Lei; Zhang, Wei-Dong; Jiang, Tao

    2016-02-01

    Isorhamnetin has been reported to have anti-inflammatory, anti-oxidative, and anti-proliferative effects. The aim of this study was to investigate the protective effect of isorhamnetin on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice by inhibiting the expression of cyclooxygenase-2 (COX-2). The effects of isorhamnetin on LPS-induced lung pathological damage, wet/dry ratios and the total protein level in bronchoalveolar lavage fluid (BALF), inflammatory cytokine release, myeloperoxidase (MPO) and superoxide dismutase (SOD) activities, and malondialdehyde (MDA) level were examined. In addition, the COX-2 activation in lung tissues was detected by Western blot. Isorhamnetin pretreatment improved the mice survival rates. Moreover, isorhamnetin pretreatment significantly attenuated edema and the pathological changes in the lung and inhibited protein extravasation in BALF. Isorhamnetin also significantly decreased the levels of inflammatory cytokines in BALF. In addition, isorhamnetin markedly prevented LPS-induced oxidative stress. Furthermore, isorhamnetin pretreatment significantly suppressed LPS-induced activation of COX-2. Isorhamnetin has been demonstrated to protect mice from LPS-induced ALI by inhibiting the expression of COX-2. PMID:26276127

  4. An update on polygalacturonase-inhibiting protein (PGIP), a leucine-rich repeat protein that protects crop plants against pathogens

    PubMed Central

    Kalunke, Raviraj M.; Tundo, Silvio; Benedetti, Manuel; Cervone, Felice; De Lorenzo, Giulia; D'Ovidio, Renato

    2015-01-01

    Polygalacturonase inhibiting proteins (PGIPs) are cell wall proteins that inhibit the pectin-depolymerizing activity of polygalacturonases secreted by microbial pathogens and insects. These ubiquitous inhibitors have a leucine-rich repeat structure that is strongly conserved in monocot and dicot plants. Previous reviews have summarized the importance of PGIP in plant defense and the structural basis of PG-PGIP interaction; here we update the current knowledge about PGIPs with the recent findings on the composition and evolution of pgip gene families, with a special emphasis on legume and cereal crops. We also update the information about the inhibition properties of single pgip gene products against microbial PGs and the results, including field tests, showing the capacity of PGIP to protect crop plants against fungal, oomycetes and bacterial pathogens. PMID:25852708

  5. An update on polygalacturonase-inhibiting protein (PGIP), a leucine-rich repeat protein that protects crop plants against pathogens.

    PubMed

    Kalunke, Raviraj M; Tundo, Silvio; Benedetti, Manuel; Cervone, Felice; De Lorenzo, Giulia; D'Ovidio, Renato

    2015-01-01

    Polygalacturonase inhibiting proteins (PGIPs) are cell wall proteins that inhibit the pectin-depolymerizing activity of polygalacturonases secreted by microbial pathogens and insects. These ubiquitous inhibitors have a leucine-rich repeat structure that is strongly conserved in monocot and dicot plants. Previous reviews have summarized the importance of PGIP in plant defense and the structural basis of PG-PGIP interaction; here we update the current knowledge about PGIPs with the recent findings on the composition and evolution of pgip gene families, with a special emphasis on legume and cereal crops. We also update the information about the inhibition properties of single pgip gene products against microbial PGs and the results, including field tests, showing the capacity of PGIP to protect crop plants against fungal, oomycetes and bacterial pathogens.

  6. Chemical PARP Inhibition Enhances Growth of Arabidopsis and Reduces Anthocyanin Accumulation and the Activation of Stress Protective Mechanisms

    PubMed Central

    Schulz, Philipp; Neukermans, Jenny; Van Der Kelen, Katrien; Mühlenbock, Per; Van Breusegem, Frank; Noctor, Graham; Teige, Markus; Metzlaff, Michael; Hannah, Matthew A.

    2012-01-01

    Poly-ADP-ribose polymerase (PARP) post-translationally modifies proteins through the addition of ADP-ribose polymers, yet its role in modulating plant development and stress responses is only poorly understood. The experiments presented here address some of the gaps in our understanding of its role in stress tolerance and thereby provide new insights into tolerance mechanisms and growth. Using a combination of chemical and genetic approaches, this study characterized phenotypes associated with PARP inhibition at the physiological level. Molecular analyses including gene expression analysis, measurement of primary metabolites and redox metabolites were used to understand the underlying processes. The analysis revealed that PARP inhibition represses anthocyanin and ascorbate accumulation under stress conditions. The reduction in defense is correlated with enhanced biomass production. Even in unstressed conditions protective genes and molecules are repressed by PARP inhibition. The reduced anthocyanin production was shown to be based on the repression of transcription of key regulatory and biosynthesis genes. PARP is a key factor for understanding growth and stress responses of plants. PARP inhibition allows plants to reduce protection such as anthocyanin, ascorbate or Non-Photochemical-Quenching whilst maintaining high energy levels likely enabling the observed enhancement of biomass production under stress, opening interesting perspectives for increasing crop productivity. PMID:22662141

  7. Inhibition of microglial activation contributes to propofol-induced protection against post-cardiac arrest brain injury in rats.

    PubMed

    Wang, Wei; Lu, Rui; Feng, Da-Yun; Liang, Li-Rong; Liu, Bing; Zhang, Hui

    2015-09-01

    It has been suggested that propofol can modulate microglial activity and hence may have potential roles against neuroinflammation following brain ischemic insult. However, whether and how propofol can inhibit post-cardiac arrest brain injury via inhibition of microglia activation remains unclear. A rat model of asphyxia cardiac arrest (CA) was created followed by cardiopulmonary resuscitation. CA induced marked microglial activation in the hippocampal CA1 region, revealed by increased OX42 and P2 class of purinoceptor 7 (P2X7R) expression, as well as p38 MAPK phosphorylation. Morris water maze showed that learning and memory deficits following CA could be inhibited or alleviated by pre-treatment with the microglial inhibitor minocycline or propofol. Microglial activation was significantly suppressed likely via the P2X7R/p-p38 pathway by propofol. Moreover, hippocampal neuronal injuries after CA were remarkably attenuated by propofol. In vitro experiment showed that propofol pre-treatment inhibited ATP-induced microglial activation and release of tumor necrosis factor-α and interleukin-1β. In addition, propofol protected neurons from injury when co-culturing with ATP-treated microglia. Our data suggest that propofol pre-treatment inhibits CA-induced microglial activation and neuronal injury in the hippocampus and ultimately improves cognitive function. We proposed a possible mechanism of propofol-mediated brain protection after cardiac arrest (CA). CA induces P2X7R upregulation and p38 phosphorylation in microglia, which induces release of TNF-α and IL-1β and consequent neuronal injury. Propofol could inhibit microglial activation and alleviate neuronal damage. Our results suggest propofol-induced anti-inflammatory treatment as a plausible strategy for therapeutic intervention in post-CA brain injury.

  8. Inhibition of H3K4me2 Demethylation Protects Auditory Hair Cells from Neomycin-Induced Apoptosis.

    PubMed

    He, Yingzi; Yu, Huiqian; Cai, Chengfu; Sun, Shan; Chai, Renjie; Li, Huawei

    2015-08-01

    Aminoglycoside-induced hair cell loss is a major cause of hearing impairment in children and deserves more attention in medical research. Epigenetic mechanisms have been shown to protect hair cells from ototoxic drugs. In this study, we focused on the role of dimethylated histone H3K4 (H3K4me2) in hair cell survival. To investigate the effects of lysine-specific demethylase 1 (LSD1)--the histone demethylase primarily responsible for demethylating H3K4me2--on neomycin-induced hair cell loss, isolated cochleae were pretreated with LSD1 inhibitors followed by neomycin exposure. There was a severe loss of hair cells in the organ of Corti after neomycin exposure, and inhibition of LSD1 significantly protected against neomycin-induced hair cell loss. H3K4me2 expression in the nuclei of hair cells decreased after exposure to neomycin, and blocking the decreased expression of H3K4me2 with LSD1 inhibitors prevented hair cell loss. Local delivery of these inhibitors in vivo also protected hair cells from neomycin-induced ototoxicity and maintained the hearing threshold in mice as determined by auditory brain stem response. This inhibition of neomycin-induced apoptosis occurs via reduced caspase-3 activation. Together, our findings demonstrate the protective role for H3K4me2 against neomycin-induced hair cell loss and hearing loss.

  9. Hydrogen sulfide preconditioning protects against myocardial ischemia/reperfusion injury in rats through inhibition of endo/sarcoplasmic reticulum stress

    PubMed Central

    Li, Changyong; Hu, Min; Wang, Yuan; Lu, Huan; Deng, Jing; Yan, Xiaohong

    2015-01-01

    Ischemia reperfusion (I/R) injury is a major cause of myocardial damage. Hydrogen sulfide (H2S), a gaseous signal molecule, has drawn considerable attention for its role in various pathophysiological processes. Multiple lines of evidence reveal the protective effects of H2S in various models of cardiac injury, however, the exact mechanism underlying this protective effect of H2S against myocardial I/R injury is not fully understood. The present study was designed to investigate whether H2S preconditioning attenuates myocardial I/R injury in rats and whether the observed protection is associated with reduced endo/sarcoplasmic reticulum (ER/SR) stress. We found that H2S preconditioning significantly reduced myocardial infarct size, preserved left ventricular function, and inhibited I/R-induced cardiomyocyte apoptosis in vivo. Furthermore, H2S preconditioning significantly attenuated I/R-induced ER/SR stress responses, including the increased expression of glucose-regulated protein 78, C/EBP homologous protein, and activate transcription factor in myocardium. Additionally, we demonstrate that H2S preconditioning attenuates ER/SR stress and inhibits cardiomyocyte apoptosis in an in vitro model of hypoxia/reoxygenation in rat H9c2 cardiac myocytes. In conclusion, these results suggest that H2S-attenuated ER/SR stress plays an important role in its protective effects against I/R-induced myocardial injury. PMID:26339339

  10. FAIM-L is an IAP-binding protein that inhibits XIAP ubiquitinylation and protects from Fas-induced apoptosis.

    PubMed

    Moubarak, Rana S; Planells-Ferrer, Laura; Urresti, Jorge; Reix, Stéphanie; Segura, Miguel F; Carriba, Paulina; Marqués-Fernàndez, Fernando; Sole, Carme; Llecha-Cano, Nuria; Lopez-Soriano, Joaquin; Sanchis, Daniel; Yuste, Victor J; Comella, Joan X

    2013-12-01

    The neuronal long isoform of Fas Apoptotic Inhibitory Molecule (FAIM-L) protects from death receptor (DR)-induced apoptosis, yet its mechanism of protection remains unknown. Here, we show that FAIM-L protects rat neuronal Type II cells from Fas-induced apoptosis. XIAP has previously emerged as a molecular discriminator that is upregulated in Type II and downregulated in Type I apoptotic signaling. We demonstrate that FAIM-L requires sustained endogenous levels of XIAP to protect Type II cells as well as murine cortical neurons from Fas-induced apoptosis. FAIM-L interacts with the BIR2 domain of XIAP through an IAP-binding motif, the mutation of which impairs the antiapoptotic function of FAIM-L. Finally, we report that FAIM-L inhibits XIAP auto-ubiquitinylation and maintains its stability, thus conferring protection from apoptosis. Our results bring new understanding of the regulation of endogenous XIAP by a DR antagonist, pointing out at FAIM-L as a promising therapeutic tool for protection from apoptosis in pathological situations where XIAP levels are decreased.

  11. Inhibition protects acquired song segments during vocal learning in zebra finches

    PubMed Central

    Vallentin, Daniela; Kosche, Georg; Lipkind, Dina; Long, Michael A.

    2016-01-01

    Vocal imitation involves incorporating instructive auditory information into relevant motor circuits through processes that are poorly understood. In zebra finches, we find that exposure to a tutor’s song drives spiking activity within premotor neurons in the juvenile but that inhibition suppresses such responses upon learning in adulthood. We measure inhibitory currents evoked by the tutor song throughout development while simultaneously quantifying each bird’s learning trajectory. Surprisingly, we find that the maturation of synaptic inhibition onto premotor neurons is correlated with learning but not age. We used synthetic tutoring to demonstrate that inhibition is selective for specific song elements that have already been learned and not those still in refinement. Our results suggest that structured inhibition is playing a crucial role during song acquisition, enabling a piece-by-piece mastery of complex tasks. PMID:26816377

  12. Neural circuits. Inhibition protects acquired song segments during vocal learning in zebra finches.

    PubMed

    Vallentin, Daniela; Kosche, Georg; Lipkind, Dina; Long, Michael A

    2016-01-15

    Vocal imitation involves incorporating instructive auditory information into relevant motor circuits through processes that are poorly understood. In zebra finches, we found that exposure to a tutor's song drives spiking activity within premotor neurons in the juvenile, whereas inhibition suppresses such responses upon learning in adulthood. We measured inhibitory currents evoked by the tutor song throughout development while simultaneously quantifying each bird's learning trajectory. Surprisingly, we found that the maturation of synaptic inhibition onto premotor neurons is correlated with learning but not age. We used synthetic tutoring to demonstrate that inhibition is selective for specific song elements that have already been learned and not those still in refinement. Our results suggest that structured inhibition plays a crucial role during song acquisition, enabling a piece-by-piece mastery of complex tasks. PMID:26816377

  13. Acetylcholine Protects against Candida albicans Infection by Inhibiting Biofilm Formation and Promoting Hemocyte Function in a Galleria mellonella Infection Model.

    PubMed

    Rajendran, Ranjith; Borghi, Elisa; Falleni, Monica; Perdoni, Federica; Tosi, Delfina; Lappin, David F; O'Donnell, Lindsay; Greetham, Darren; Ramage, Gordon; Nile, Christopher

    2015-08-01

    Both neuronal acetylcholine and nonneuronal acetylcholine have been demonstrated to modulate inflammatory responses. Studies investigating the role of acetylcholine in the pathogenesis of bacterial infections have revealed contradictory findings with regard to disease outcome. At present, the role of acetylcholine in the pathogenesis of fungal infections is unknown. Therefore, the aim of this study was to determine whether acetylcholine plays a role in fungal biofilm formation and the pathogenesis of Candida albicans infection. The effect of acetylcholine on C. albicans biofilm formation and metabolism in vitro was assessed using a crystal violet assay and phenotypic microarray analysis. Its effect on the outcome of a C. albicans infection, fungal burden, and biofilm formation were investigated in vivo using a Galleria mellonella infection model. In addition, its effect on modulation of host immunity to C. albicans infection was also determined in vivo using hemocyte counts, cytospin analysis, larval histology, lysozyme assays, hemolytic assays, and real-time PCR. Acetylcholine was shown to have the ability to inhibit C. albicans biofilm formation in vitro and in vivo. In addition, acetylcholine protected G. mellonella larvae from C. albicans infection mortality. The in vivo protection occurred through acetylcholine enhancing the function of hemocytes while at the same time inhibiting C. albicans biofilm formation. Furthermore, acetylcholine also inhibited inflammation-induced damage to internal organs. This is the first demonstration of a role for acetylcholine in protection against fungal infections, in addition to being the first report that this molecule can inhibit C. albicans biofilm formation. Therefore, acetylcholine has the capacity to modulate complex host-fungal interactions and plays a role in dictating the pathogenesis of fungal infections.

  14. Acetylcholine Protects against Candida albicans Infection by Inhibiting Biofilm Formation and Promoting Hemocyte Function in a Galleria mellonella Infection Model

    PubMed Central

    Rajendran, Ranjith; Borghi, Elisa; Falleni, Monica; Perdoni, Federica; Tosi, Delfina; Lappin, David F.; O'Donnell, Lindsay; Greetham, Darren; Ramage, Gordon

    2015-01-01

    Both neuronal acetylcholine and nonneuronal acetylcholine have been demonstrated to modulate inflammatory responses. Studies investigating the role of acetylcholine in the pathogenesis of bacterial infections have revealed contradictory findings with regard to disease outcome. At present, the role of acetylcholine in the pathogenesis of fungal infections is unknown. Therefore, the aim of this study was to determine whether acetylcholine plays a role in fungal biofilm formation and the pathogenesis of Candida albicans infection. The effect of acetylcholine on C. albicans biofilm formation and metabolism in vitro was assessed using a crystal violet assay and phenotypic microarray analysis. Its effect on the outcome of a C. albicans infection, fungal burden, and biofilm formation were investigated in vivo using a Galleria mellonella infection model. In addition, its effect on modulation of host immunity to C. albicans infection was also determined in vivo using hemocyte counts, cytospin analysis, larval histology, lysozyme assays, hemolytic assays, and real-time PCR. Acetylcholine was shown to have the ability to inhibit C. albicans biofilm formation in vitro and in vivo. In addition, acetylcholine protected G. mellonella larvae from C. albicans infection mortality. The in vivo protection occurred through acetylcholine enhancing the function of hemocytes while at the same time inhibiting C. albicans biofilm formation. Furthermore, acetylcholine also inhibited inflammation-induced damage to internal organs. This is the first demonstration of a role for acetylcholine in protection against fungal infections, in addition to being the first report that this molecule can inhibit C. albicans biofilm formation. Therefore, acetylcholine has the capacity to modulate complex host-fungal interactions and plays a role in dictating the pathogenesis of fungal infections. PMID:26092919

  15. Heat shock protein 90 inhibition by 17-Dimethylaminoethylamino-17-demethoxygeldanamycin protects blood-brain barrier integrity in cerebral ischemic stroke.

    PubMed

    Qi, Jia; Liu, Yan; Yang, Ping; Chen, Ting; Liu, Xin Zhu; Yin, You; Zhang, Jian; Wang, Feng

    2015-01-01

    Metalloproteinase (MMP)9 plays a pivotal role in ischemic stroke induced blood brain barrier (BBB) disruption. Correlation between HSP90 and MMP9 in several diseases prompted us to evaluate the efficacy of HSP90 inhibition as a novel approach to protect BBB integrity in ischemic stroke. ELISA was used to detect HSP90α and MMP9 in serum samples of stroke patients, which showed that HSP90α significantly correlated with MMP9 among 63 serum samples of stroke patients. Male C57/BL6 mice were pretreated with 17-Dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG) or vehicle before being subjected to transient occlusion of middle cerebral artery and reperfusion (MCAO). Infarction, neurological scores, Evans blue (EB) extravasation, inflammatory responses and tight junction protein expression were examined 24 h after MCAO. We also investigated if 17-DMAG protected BBB integrity by suppressing inflammation and MMP9 activation. Oxygen glucose deprivation (OGD) was performed on bEnd.3 cells to explore the mechanisms of HSP90 inhibition in inhibiting MMP9. The results demonstrated that infarct volume was reduced in 17-DMAG-treated mice compared to control group following MCAO. Neurological outcomes were greatly improved in 17-DMAG-treated mice. Inflammatory responses, MMP9 activity and EB extravasation were decreased by 17-DMAG. In addition, 17-DMAG inhibited nuclear factor kappa B (NF-κB) activation following MCAO. Furthermore, HSP90 inhibition decreased NF-κB dependent MMP9 expression in bEnd.3 after OGD /reoxygenation. These findings suggested that HSP90 could be a novel therapeutic target in BBB breakdown during ischemic stroke. As several HSP90 inhibitors are in clinical trials for cancer, these findings have translational implications. PMID:26692927

  16. Heat shock protein 90 inhibition by 17-Dimethylaminoethylamino-17-demethoxygeldanamycin protects blood-brain barrier integrity in cerebral ischemic stroke

    PubMed Central

    Qi, Jia; Liu, Yan; Yang, Ping; Chen, Ting; Liu, Xin Zhu; Yin, You; Zhang, Jian; Wang, Feng

    2015-01-01

    Metalloproteinase (MMP)9 plays a pivotal role in ischemic stroke induced blood brain barrier (BBB) disruption. Correlation between HSP90 and MMP9 in several diseases prompted us to evaluate the efficacy of HSP90 inhibition as a novel approach to protect BBB integrity in ischemic stroke. ELISA was used to detect HSP90α and MMP9 in serum samples of stroke patients, which showed that HSP90α significantly correlated with MMP9 among 63 serum samples of stroke patients. Male C57/BL6 mice were pretreated with 17-Dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG) or vehicle before being subjected to transient occlusion of middle cerebral artery and reperfusion (MCAO). Infarction, neurological scores, Evans blue (EB) extravasation, inflammatory responses and tight junction protein expression were examined 24 h after MCAO. We also investigated if 17-DMAG protected BBB integrity by suppressing inflammation and MMP9 activation. Oxygen glucose deprivation (OGD) was performed on bEnd.3 cells to explore the mechanisms of HSP90 inhibition in inhibiting MMP9. The results demonstrated that infarct volume was reduced in 17-DMAG-treated mice compared to control group following MCAO. Neurological outcomes were greatly improved in 17-DMAG-treated mice. Inflammatory responses, MMP9 activity and EB extravasation were decreased by 17-DMAG. In addition, 17-DMAG inhibited nuclear factor kappa B (NF-κB) activation following MCAO. Furthermore, HSP90 inhibition decreased NF-κB dependent MMP9 expression in bEnd.3 after OGD /reoxygenation. These findings suggested that HSP90 could be a novel therapeutic target in BBB breakdown during ischemic stroke. As several HSP90 inhibitors are in clinical trials for cancer, these findings have translational implications. PMID:26692927

  17. Schisandrol B protects against acetaminophen-induced hepatotoxicity by inhibition of CYP-mediated bioactivation and regulation of liver regeneration.

    PubMed

    Jiang, Yiming; Fan, Xiaomei; Wang, Ying; Chen, Pan; Zeng, Hang; Tan, Huasen; Gonzalez, Frank J; Huang, Min; Bi, Huichang

    2015-01-01

    Acetaminophen (APAP) overdose is the most frequent cause of drug-induced acute liver failure. Schisandra sphenanthera is a traditional hepato-protective Chinese medicine and Schisandrol B (SolB) is one of its major active constituents. In this study, the protective effect of SolB against APAP-induced acute hepatotoxicity in mice and the involved mechanisms were investigated. Morphological and biochemical assessments clearly demonstrated a protective effect of SolB against APAP-induced liver injury. SolB pretreatment significantly attenuated the increases in alanine aminotransferase and aspartate aminotransferase activity, and prevented elevated hepatic malondialdehyde formation and the depletion of mitochondrial glutathione (GSH) in a dose-dependent manner. SolB also dramatically altered APAP metabolic activation by inhibiting the activities of CYP2E1 and CYP3A11, which was evidenced by significant inhibition of the formation of the oxidized APAP metabolite NAPQI-GSH. A molecular docking model also predicted that SolB had potential to interact with the CYP2E1 and CYP3A4 active sites. In addition, SolB abrogated APAP-induced activation of p53 and p21, and increased expression of liver regeneration and antiapoptotic-related proteins such as cyclin D1 (CCND1), PCNA, and BCL-2. This study demonstrated that SolB exhibited a significant protective effect toward APAP-induced liver injury, potentially through inhibition of CYP-mediated APAP bioactivation and regulation of the p53, p21, CCND1, PCNA, and BCL-2 to promote liver regeneration. PMID:25319358

  18. Schisandrol B protects against acetaminophen-induced hepatotoxicity by inhibition of CYP-mediated bioactivation and regulation of liver regeneration.

    PubMed

    Jiang, Yiming; Fan, Xiaomei; Wang, Ying; Chen, Pan; Zeng, Hang; Tan, Huasen; Gonzalez, Frank J; Huang, Min; Bi, Huichang

    2015-01-01

    Acetaminophen (APAP) overdose is the most frequent cause of drug-induced acute liver failure. Schisandra sphenanthera is a traditional hepato-protective Chinese medicine and Schisandrol B (SolB) is one of its major active constituents. In this study, the protective effect of SolB against APAP-induced acute hepatotoxicity in mice and the involved mechanisms were investigated. Morphological and biochemical assessments clearly demonstrated a protective effect of SolB against APAP-induced liver injury. SolB pretreatment significantly attenuated the increases in alanine aminotransferase and aspartate aminotransferase activity, and prevented elevated hepatic malondialdehyde formation and the depletion of mitochondrial glutathione (GSH) in a dose-dependent manner. SolB also dramatically altered APAP metabolic activation by inhibiting the activities of CYP2E1 and CYP3A11, which was evidenced by significant inhibition of the formation of the oxidized APAP metabolite NAPQI-GSH. A molecular docking model also predicted that SolB had potential to interact with the CYP2E1 and CYP3A4 active sites. In addition, SolB abrogated APAP-induced activation of p53 and p21, and increased expression of liver regeneration and antiapoptotic-related proteins such as cyclin D1 (CCND1), PCNA, and BCL-2. This study demonstrated that SolB exhibited a significant protective effect toward APAP-induced liver injury, potentially through inhibition of CYP-mediated APAP bioactivation and regulation of the p53, p21, CCND1, PCNA, and BCL-2 to promote liver regeneration.

  19. Potent inhibition of peroxynitrite-induced DNA strand breakage by ethanol: possible implications for ethanol-mediated cardiovascular protection.

    PubMed

    Cao, Zhuoxiao; Li, Yunbo

    2004-07-01

    Epidemiological studies have conclusively demonstrated that moderate consumption of ethanol is causally associated with a significant reduction in cardiovascular events. However, the exact mechanisms underlying the ethanol-mediated cardiovascular protection remain to be elucidated. Because peroxynitrite has been extensively implicated in the pathogenesis of various forms of cardiovascular disorders via its cytotoxic effects, this study was undertaken to investigate if ethanol could inhibit peroxynitrite-induced DNA strand breaks, a critical event leading to peroxynitrite-elicited cytotoxicity. Toward this goal, phiX-174 RF I plasmid DNA was used as an in vitro model to determine the protective effects of ethanol on peroxynitrite-induced DNA strand breaks. Incubation of phiX-174 plasmid DNA with the peroxynitrite generator, 3-morpholinosydnonimine (SIN-1) led to the formation of both single- and double-stranded DNA breaks in a concentration- and time-dependent fashion. The presence of ethanol at concentrations ranging from 0.01 to 1% (w/v) resulted in a significant inhibition of SIN-1-induced DNA strand breaks. Ethanol also showed inhibitory effects on SIN-1-induced DNA strand breakage in the presence of bicarbonate. The inhibition of SIN-1-induced DNA strand breaks by ethanol exhibited a concentration-dependent manner. Notably, a marked inhibition of SIN-1-elicited DNA strand breaks was observed with 0.01% ethanol. Ethanol at 0.01-1% was unable to affect SIN-1-mediated oxygen consumption, indicating that ethanol did not affect the auto-oxidation of SIN-1 to form peroxynitrite. Furthermore, incubation of the plasmid DNA with authentic peroxynitrite resulted in a significant formation of DNA strand breaks, which could be dramatically inhibited by the presence of 0.02-0.1% ethanol. Taken together, this study demonstrates for the first time that ethanol at physiologically relevant concentrations can potently inhibit peroxynitrite-induced DNA strand breakage. In view of

  20. Minocycline protects cardiac myocytes against simulated ischemia-reperfusion injury by inhibiting poly(ADP-ribose) polymerase-1

    PubMed Central

    Tao, Rong; Kim, Sun Hee; Honbo, Norman; Karliner, Joel S.; Alano, Conrad C.

    2010-01-01

    There is an increase in reactive oxygen and nitrogen species in cardiomyocytes during myocardial ischemia/reperfusion injury. This leads to oxidative DNA damage and activation of nuclear repair enzymes such as poly(ADP-ribose) polymerase-1 (PARP-1). PARP-1 activation promotes DNA repair under normal conditions. However, excessive activation of PARP-1 leads to cell death. Here we report that PARP-1 enzymatic activity is directly inhibited by minocycline, and we propose that one mechanism of minocycline cardioprotection is due to PARP-1 inhibition. Using cultured adult rat cardiac myocytes, we evaluated the mechanism of minocycline protection in which PARP-1 activation was induced by simulated ischemia/reperfusion (sI/R) injury using oxygen-glucose deprivation. We found an increase in reactive oxygen species production, PARP-1 activation, and PARP-1-mediated cell death after sI/R. Cell death was significantly reduced by the PARP inhibitors DPQ (10 μM) and PJ-34 (500 nM), or by minocycline (500 nM). Cellular NAD+ depletion and poly(ADP-ribose) formation, which are biochemical markers of PARP-1 activation, were also blocked by minocycline. Finally, sI/R led to induction of the mitochondrial permeability transition (MPT), which was prevented by minocycline. Therefore, we propose that the protective effect of minocycline on cardiac myocyte survival is due to inhibition of PARP-1 activity. PMID:20881608

  1. Myofiber-specific inhibition of TGFβ signaling protects skeletal muscle from injury and dystrophic disease in mice

    PubMed Central

    Accornero, Federica; Kanisicak, Onur; Tjondrokoesoemo, Andoria; Attia, Aria C.; McNally, Elizabeth M.; Molkentin, Jeffery D.

    2014-01-01

    Muscular dystrophy (MD) is a disease characterized by skeletal muscle necrosis and the progressive accumulation of fibrotic tissue. While transforming growth factor (TGF)-β has emerged as central effector of MD and fibrotic disease, the cell types in diseased muscle that underlie TGFβ-dependent pathology have not been segregated. Here, we generated transgenic mice with myofiber-specific inhibition of TGFβ signaling owing to expression of a TGFβ type II receptor dominant-negative (dnTGFβRII) truncation mutant. Expression of dnTGFβRII in myofibers mitigated the dystrophic phenotype observed in δ-sarcoglycan-null (Sgcd−/−) mice through a mechanism involving reduced myofiber membrane fragility. The dnTGFβRII transgene also reduced muscle injury and improved muscle regeneration after cardiotoxin injury, as well as increased satellite cell numbers and activity. An unbiased global expression analysis revealed a number of potential mechanisms for dnTGFβRII-mediated protection, one of which was induction of the antioxidant protein metallothionein (Mt). Indeed, TGFβ directly inhibited Mt gene expression in vitro, the dnTGFβRII transgene conferred protection against reactive oxygen species accumulation in dystrophic muscle and treatment with Mt mimetics protected skeletal muscle upon injury in vivo and improved the membrane stability of dystrophic myofibers. Hence, our results show that the myofibers are central mediators of the deleterious effects associated with TGFβ signaling in MD. PMID:25106553

  2. Inhibition of de novo ceramide biosynthesis by FTY720 protects rat retina from light-induced degeneration[S

    PubMed Central

    Chen, Hui; Tran, Julie-Thu A.; Eckerd, Annette; Huynh, Tuan-Phat; Elliott, Michael H.; Brush, Richard S.; Mandal, Nawajes A.

    2013-01-01

    Light-induced retinal degeneration (LIRD) in albino rats causes apoptotic photoreceptor cell death. Ceramide is a second messenger for apoptosis. We tested whether increases in ceramide mediate photoreceptor apoptosis in LIRD and if inhibition of ceramide synthesis protects the retina. Sprague-Dawley rats were exposed to 2,700 lux white light for 6 h, and the retinal levels of ceramide and its intermediary metabolites were measured by GC-MS or electrospray ionization tandem mass spectrometry. Enzymes of the de novo biosynthetic and sphingomyelinase pathways of ceramide generation were assayed, and gene expression was measured. The dosage and temporal effect of the ceramide synthase inhibitor FTY720 on the LIRD retina were measured by histological and functional analyses. Retinal ceramide levels increased coincident with the increase of dihydroceramide at various time points after light stress. Light stress in retina induces ceramide generation predominantly through the de novo pathway, which was prevented by systemic administration of FTY720 (10 mg/kg) leading to the protection of retinal structure and function. The neuroprotection of FTY720 was independent of its immunosuppressive action. We conclude that ceramide increase by de novo biosynthesis mediates photoreceptor apoptosis in the LIRD model and that inhibition of ceramide production protects the retina against light stress. PMID:23468130

  3. Inhibition of Store-Operated Calcium Entry Protects Endothelial Progenitor Cells from H2O2-Induced Apoptosis

    PubMed Central

    Wang, Yan-Wei; Zhang, Ji-Hang; Yu, Yang; Yu, Jie; Huang, Lan

    2016-01-01

    Store-operated calcium entry (SOCE), a major mode of extracellular calcium entry, plays roles in a variety of cell activities. Accumulating evidence indicates that the intracellular calcium ion concentration and calcium signaling are critical for the responses induced by oxidative stress. The present study was designed to investigate the potential effect of SOCE inhibition on H2O2-induced apoptosis in endothelial progenitor cells (EPCs), which are the predominant cells involved in endothelial repair. The results showed that H2O2-induced EPC apoptosis was reversed by SOCE inhibition induced either using the SOCE antagonist ML-9 or via silencing of stromal interaction molecule 1 (STIM1), a component of SOCE. Furthermore, SOCE inhibition repressed the increases in intracellular reactive oxygen species (ROS) levels and endoplasmic reticulum (ER) stress and ameliorated the mitochondrial dysfunction caused by H2O2. Our findings provide evidence that SOCE inhibition exerts a protective effect on EPCs in response to oxidative stress induced by H2O2 and may serve as a potential therapeutic strategy against vascular endothelial injury. PMID:27169819

  4. DNA-AuNP networks on cell membranes as a protective barrier to inhibit viral attachment, entry and budding.

    PubMed

    Li, Chun Mei; Zheng, Lin Ling; Yang, Xiao Xi; Wan, Xiao Yan; Wu, Wen Bi; Zhen, Shu Jun; Li, Yuan Fang; Luo, Ling Fei; Huang, Cheng Zhi

    2016-01-01

    Viral infections have caused numerous diseases and deaths worldwide. Due to the emergence of new viruses and frequent virus variation, conventional antiviral strategies that directly target viral or cellular proteins are limited because of the specificity, drug resistance and rapid clearance from the human body. Therefore, developing safe and potent antiviral agents with activity against viral infection at multiple points in the viral life cycle remains a major challenge. In this report, we propose a new modality to inhibit viral infection by fabricating DNA conjugated gold nanoparticle (DNA-AuNP) networks on cell membranes as a protective barrier. The DNA-AuNPs networks were found, via a plaque formation assay and viral titers, to have potent antiviral ability and protect host cells from human respiratory syncytial virus (RSV). Confocal immunofluorescence image analysis showed 80 ± 3.8% of viral attachment, 91.1 ± 0.9% of viral entry and 87.9 ± 2.8% of viral budding were inhibited by the DNA-AuNP networks, which were further confirmed by real-time fluorescence imaging of the RSV infection process. The antiviral activity of the networks may be attributed to steric effects, the disruption of membrane glycoproteins and limited fusion of cell membrane bilayers, all of which play important roles in viral infection. Therefore, our results suggest that the DNA-AuNP networks have not only prophylactic effects to inhibit virus attachment and entry, but also therapeutic effects to inhibit viral budding and cell-to-cell spread. More importantly, this proof-of-principle study provides a pathway for the development of a universal, broad-spectrum antiviral therapy.

  5. Plant Food Delphinidin-3-Glucoside Significantly Inhibits Platelet Activation and Thrombosis: Novel Protective Roles against Cardiovascular Diseases

    PubMed Central

    Yang, Yan; Shi, Zhenyin; Reheman, Adili; Jin, Joseph W.; Li, Conglei; Wang, Yiming; Andrews, Marc C.; Chen, Pingguo; Zhu, Guangheng; Ling, Wenhua; Ni, Heyu

    2012-01-01

    Delphinidin-3-glucoside (Dp-3-g) is one of the predominant bioactive compounds of anthocyanins in many plant foods. Although several anthocyanin compounds have been reported to be protective against cardiovascular diseases (CVDs), the direct effect of anthocyanins on platelets, the key players in atherothrombosis, has not been studied. The roles of Dp-3-g in platelet function are completely unknown. The present study investigated the effects of Dp-3-g on platelet activation and several thrombosis models in vitro and in vivo. We found that Dp-3-g significantly inhibited human and murine platelet aggregation in both platelet-rich plasma and purified platelets. It also markedly reduced thrombus growth in human and murine blood in perfusion chambers at both low and high shear rates. Using intravital microscopy, we observed that Dp-3-g decreased platelet deposition, destabilized thrombi, and prolonged the time required for vessel occlusion. Dp-3-g also significantly inhibited thrombus growth in a carotid artery thrombosis model. To elucidate the mechanisms, we examined platelet activation markers via flow cytometry and found that Dp-3-g significantly inhibited the expression of P-selectin, CD63, CD40L, which reflect platelet α- and δ-granule release, and cytosol protein secretion, respectively. We further demonstrated that Dp-3-g downregulated the expression of active integrin αIIbβ3 on platelets, and attenuated fibrinogen binding to platelets following agonist treatment, without interfering with the direct interaction between fibrinogen and integrin αIIbβ3. We found that Dp-3-g reduced phosphorylation of adenosine monophosphate-activated protein kinase, which may contribute to the observed inhibitory effects on platelet activation. Thus, Dp-3-g significantly inhibits platelet activation and attenuates thrombus growth at both arterial and venous shear stresses, which likely contributes to its protective roles against thrombosis and CVDs. PMID:22624015

  6. Tankyrase and the canonical Wnt pathway protect lung cancer cells from EGFR inhibition

    PubMed Central

    Casás-Selves, Matias; Kim, Jihye; Zhang, Zhiyong; Helfrich, Barbara A.; Gao, Dexiang; Porter, Christopher C.; Scarborough, Hannah A.; Bunn, Paul A.; Chan, Daniel C.; Tan, Aik Choon; DeGregori, James

    2013-01-01

    Lung cancer is the leading cause of death worldwide. Adenocarcinomas, the most common histological subtype of non-small cell lung cancer (NSCLC), are frequently associated with activating mutations in the epidermal growth factor receptor (EGFR) gene. Although these patients often respond clinically to the EGFR tyrosine kinase inhibitors erlotinib and gefitinib, relapse inevitably occurs, suggesting the development of escape mechanisms that promote cell survival. Using a loss-of-function, whole genome shRNA screen, we identified that the canonical Wnt pathway contributes to the maintenance of NSCLC cells during EGFR inhibition, particularly the poly-ADP-ribosylating enzymes tankyrase 1 and 2 that positively regulate canonical Wnt signaling. Inhibition of tankyrase and various other components of the Wnt pathway with shRNAs or small molecules significantly increased the efficacy of EGFR inhibitors both in vitro and in vivo. Our findings therefore reveal a critical role for tankyrase and the canonical Wnt pathway in maintaining lung cancer cells during EGFR inhibition. Targeting the Wnt-tankyrase-β-catenin pathway together with EGFR inhibition may improve clinical outcome in patients with NSCLC. PMID:22738915

  7. Selective inhibition of class I but not class IIb histone deacetylases exerts cardiac protection from ischemia reperfusion.

    PubMed

    Aune, Sverre E; Herr, Daniel J; Mani, Santhosh K; Menick, Donald R

    2014-07-01

    While inhibition of class I/IIb histone deacetylases (HDACs) protects the mammalian heart from ischemia reperfusion (IR) injury, class selective effects remain unexamined. We hypothesized that selective inhibition of class I HDACs would preserve left ventricular contractile function following IR in isolated hearts. Male Sprague Dawley rats (n=6 per group) were injected with vehicle (dimethylsulfoxide, 0.63mg/kg), the class I/IIb HDAC inhibitor trichostatin A (1mg/kg), the class I HDAC inhibitor entinostat (MS-275, 10mg/kg), or the HDAC6 (class IIb) inhibitor tubastatin A (10mg/kg). After 24h, hearts were isolated and perfused in Langendorff mode for 30min (Sham) or subjected to 30min global ischemia and 120min global reperfusion (IR). A saline filled balloon attached to a pressure transducer was placed in the LV to monitor contractile function. After perfusion, LV tissue was collected for measurements of antioxidant protein levels and infarct area. At the conclusion of IR, MS-275 pretreatment was associated with significant preservation of developed pressure, rate of pressure generation, rate of pressure relaxation and rate pressure product, as compared to vehicle treated hearts. There was significant reduction of infarct area with MS-275 pretreatment. Contractile function was not significantly restored in hearts treated with trichostatin A or tubastatin A. Mitochondrial superoxide dismutase (SOD2) and catalase protein and mRNA in hearts from animals pretreated with MS-275 were increased following IR, as compared to Sham. This was associated with a dramatic enrichment of nuclear FOXO3a transcription factor, which mediates the expression of SOD2 and catalase. Tubastatin A treatment was associated with significantly decreased catalase levels after IR. Class I HDAC inhibition elicits protection of contractile function following IR, which is associated with increased expression of endogenous antioxidant enzymes. Class I/IIb HDAC inhibition with trichostatin A or

  8. Depletion of PHD3 Protects Heart from Ischemia/Reperfusion Injury by Inhibiting Cardiomyocyte Apoptosis

    PubMed Central

    Xie, Liang; Pi, Xinchun; Wang, Zhongjing; He, Jun; Willis, Monte S.; Patterson, Cam

    2015-01-01

    PHD3, a member of a family of Prolyl-4 Hydroxylase Domain (PHD) proteins, has long been considered a pro-apoptotic protein. Although the pro-apoptotic effect of PHD3 requires its prolyl hydroxylase activity, it may be independent of HIF-1α, the common substrate of PHDs. PHD3 is highly expressed in the heart, however, its role in cardiomyocyte apoptosis remains unclear. This study was undertaken to determine whether inhibition or depletion of PHD3 inhibits cardiomyocyte apoptosis and attenuates myocardial injury induced by ischemia-reperfusion (I/R). PHD3 knockout mice and littermate controls were subjected to left anterior descending (LAD) coronary artery ligation for 40 minutes followed by reperfusion. Histochemical analysis using Evan’s Blue, triphenyl-tetrazolium chloride and TUNEL staining, demonstrated that myocardial injury and cardiomyocyte apoptosis induced I/R injury were significantly attenuated in PHD3 knockout mice. PHD3 knockout mice exhibited no changes in HIF-1α protein level, the expression of some HIF target genes or the myocardium capillary density at physiological condition. However, depletion of PHD3 further enhanced the induction of HIF-1α protein at hypoxic condition and increased expression of HIF-1α inhibited cardiomyocyte apoptosis induced by hypoxia. In addition, it has been demonstrated that PHD3 plays an important role in ATR/Chk1/p53 pathway. Consistently, a prolyl hydroxylase inhibitor or depletion of PHD3 significantly inhibits the activation of Chk1 and p53 in cardiomyocytes and the subsequent apoptosis induced by doxorubicin, hydrogen peroxide or hypoxia/re-oxygenation. Taken together, these data suggest that depletion of PHD3 leads to increased stabilization of HIF-1α and inhibition of DNA damage response, both of which may contribute to the cardioprotective effect seen with depletion of PHD3. PMID:25633836

  9. TRPC1 protects human SH-SY5Y cells against salsolinol-induced cytotoxicity by inhibiting apoptosis.

    PubMed

    Bollimuntha, Sunitha; Ebadi, Manuchair; Singh, Brij B

    2006-07-12

    Salsolinol, an endogenous neurotoxin, may be involved in the pathogenesis of Parkinson's disease. In this study, we sought to determine whether salsolinol-induced cytotoxicity in SH-SY5Y human neuroblastoma cells, a cloned cell line which expresses dopaminergic activity, could be prevented by overexpressing a Ca(2+) channel, transient receptor potential (TRPC1) protein. Exposure of SH-SY5Y cells to 500 microM salsolinol for 12 h resulted in a significant decrease in thapsigargin or carbachol-mediated Ca(2+) influx. Consistent with these results, SH-SY5Y cells treated with salsolinol showed approximately 60% reduction in TRPC1 protein levels. Confocal microscopy also showed that SH-SY5Y cells treated with salsolinol had a significant decrease in the plasma membrane staining of the TRPC1 protein. Interestingly, overexpression of TRPC1 increases TRPC1 protein levels and also protected SH-SY5Y neuroblastoma cells against salsolinol-mediated cytotoxicity as determined by 3,[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. The protective effect of TRPC1 was blocked by the addition of TRPC1 blockers lanthanum, or 2APB. Activation of TRPC1 protein by either thapsigargin or carbachol further protected SH-SY5Y cells from salsolinol treatments. Staining of SH-SY5Y cells with an apoptotic marker (YO-PRO-1) showed that TRPC1 protein protects against apoptosis. Furthermore, TRPC1 overexpression also inhibited cytochrome c release and decreased BAX protein levels required for apoptosis. Taken together, these findings suggest that the reduction in cell surface TRPC1 protein expression in response to salsolinol may be a contributory factor in cellular toxicity of the dopaminergic neurons. Furthermore, overexpression of TRPC1 could inhibit apoptotic complex thereby increasing neuronal cell survivability in Parkinson's disease.

  10. Zeaxanthin and Echinenone Protect the Repair of Photosystem II from Inhibition by Singlet Oxygen in Synechocystis sp. PCC 6803.

    PubMed

    Kusama, Yuri; Inoue, Shuhei; Jimbo, Haruhiko; Takaichi, Shinichi; Sonoike, Kintake; Hihara, Yukako; Nishiyama, Yoshitaka

    2015-05-01

    Carotenoids are important components of antioxidative systems in photosynthetic organisms. We investigated the roles of zeaxanthin and echinenone in the protection of PSII from photoinhibition in Synechocystis sp. PCC 6803, using mutants of the cyanobacterium that lack these carotenoids. The activity of PSII in mutant cells deficient in either zeaxanthin or echinenone was more sensitive to strong light than the activity in wild-type cells, and the activity in mutant cells deficient in both carotenoids was hypersensitive to strong light, indicating that the absence of these carotenoids increased the extent of photoinhibition. Nonetheless, the rate of photodamage to PSII, as measured in the presence of chloramphenicol, which blocks the repair of PSII, was unaffected by the absence of either carotenoid, suggesting that these carotenoids might act by protecting the repair of PSII. Knockout of the gene for the so-called orange carotenoid protein (OCP), in which the 3'-hydroxyechinenone cofactor, a derivative of echinenone, is responsible for the thermal dissipation of excitation energy, increased the extent of photoinhibition but did not affect photodamage, suggesting that thermal dissipation also protects the repair of PSII. In mutant cells lacking OCP, as well as those lacking zeaxanthin and echinenone, the production of singlet oxygen was stimulated and the synthesis de novo of various proteins, including the D1 protein, was markedly suppressed under strong light. These observations suggest that the carotenoids and thermal dissipation might protect the repair of photodamaged PSII by depressing the levels of singlet oxygen that inhibits protein synthesis.

  11. Breast milk protects against the development of necrotizing enterocolitis through inhibition of Toll Like Receptor 4 in the intestinal epithelium via activation of the epidermal growth factor receptor

    PubMed Central

    Good, Misty; Sodhi, Chhinder P.; Egan, Charlotte E.; Afrazi, Amin; Jia, Hongpeng; Yamaguchi, Yukihiro; Lu, Peng; Branca, Maria F.; Ma, Congrong; Prindle, Thomas; Mielo, Samantha; Pompa, Anthony; Hodzic, Zerina; Ozolek, John A.; Hackam, David J.

    2015-01-01

    Breast milk is the most effective strategy to protect infants against necrotizing enterocolitis (NEC), a devastating disease which is characterized by severe intestinal necrosis. Previous studies have demonstrated that the lipopolysaccharide receptor toll-like receptor 4 (TLR4) plays a critical role in NEC development via deleterious effects on mucosal injury and repair. We now hypothesize that breast milk protects against NEC by inhibiting TLR4 within the intestinal epithelium, and sought to determine the mechanisms involved. Breast milk protected against NEC and reduced TLR4 signaling in wild-type neonatal mice, but not in mice lacking the epidermal growth factor receptor (EGFR), while selective removal of EGF from breast milk reduced its protective properties, indicating that breast milk inhibits NEC and attenuates TLR4 signaling via EGF/EGFR activation. Over-expression of TLR4 in the intestinal epithelium reversed the protective effects of breast milk. The protective effects of breast milk occurred via inhibition of enterocyte apoptosis and restoration of enterocyte proliferation. Importantly, in IEC-6 enterocytes, breast milk inhibited TLR4 signaling via inhibition of GSK3β. Taken together, these findings offer mechanistic insights into the protective role for breast milk in NEC, and support a link between growth factor and innate immune receptors in NEC pathogenesis. PMID:25899687

  12. Fenamate NSAIDs inhibit the NLRP3 inflammasome and protect against Alzheimer's disease in rodent models

    PubMed Central

    Daniels, Michael J. D.; Rivers-Auty, Jack; Schilling, Tom; Spencer, Nicholas G.; Watremez, William; Fasolino, Victoria; Booth, Sophie J.; White, Claire S.; Baldwin, Alex G.; Freeman, Sally; Wong, Raymond; Latta, Clare; Yu, Shi; Jackson, Joshua; Fischer, Nicolas; Koziel, Violette; Pillot, Thierry; Bagnall, James; Allan, Stuart M.; Paszek, Pawel; Galea, James; Harte, Michael K.; Eder, Claudia; Lawrence, Catherine B.; Brough, David

    2016-01-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenase-1 (COX-1) and COX-2 enzymes. The NLRP3 inflammasome is a multi-protein complex responsible for the processing of the proinflammatory cytokine interleukin-1β and is implicated in many inflammatory diseases. Here we show that several clinically approved and widely used NSAIDs of the fenamate class are effective and selective inhibitors of the NLRP3 inflammasome via inhibition of the volume-regulated anion channel in macrophages, independently of COX enzymes. Flufenamic acid and mefenamic acid are efficacious in NLRP3-dependent rodent models of inflammation in air pouch and peritoneum. We also show therapeutic effects of fenamates using a model of amyloid beta induced memory loss and a transgenic mouse model of Alzheimer's disease. These data suggest that fenamate NSAIDs could be repurposed as NLRP3 inflammasome inhibitors and Alzheimer's disease therapeutics. PMID:27509875

  13. Temporary protection of metals against atmospheric corrosion by saturated straight chain aliphatic monocarboxylates. Mechanisms of inhibition

    SciTech Connect

    Kapin, C.; Steinmetz, P.; Steinmetz, J.

    1998-12-31

    This work was devoted to the investigations of the ability of saturated straight chain aliphatic monocarboxylates to inhibit corrosion of mild steel and zinc in aerated aqueous solutions. Performances of inhibitors were shown to be dependent on their chain length, their concentration and the immersion duration. Both crystallographic parameters and solubilities of iron and zinc carboxylates were determined. Then potential-pH diagrams of iron and zinc in water were built taking the presence of metallic soaps into account. According to these diagrams, the passivation of metals was attributed to the growth of films containing metallic soaps. This model confirms that previously proposed for inhibition of copper and magnesium by the same carboxylates.

  14. Discovery of a potent cyclooxygenase-2 inhibitor, S4, through docking-based pharmacophore screening, in vivo and in vitro estimations.

    PubMed

    Tseng, Tien-Sheng; Chuang, Show-Mei; Hsiao, Nai-Wan; Chen, Yi-Wen; Lee, Yu-Ching; Lin, Chi-Chen; Huang, Cheng; Tsai, Keng-Chang

    2016-07-19

    Cyclooxygenase (COX; EC: 1.14.99.1), the key enzyme in prostaglandin production in the human body, is a major pharmacological target for developing anti-inflammatory agents. Nonsteroidal anti-inflammatory drugs exhibit anti-inflammatory and analgesic activities when inhibiting COX-2 but cause gastrointestinal toxicity and other side effects because of concurrent inhibition of COX-1. Thus, potent and safe inhibitors against COX-2 are urgently required. We constructed a novel docking-based pharmacophore model for screening selective COX-2 inhibitors and discovered compounds S1, S2, S3, and S4, which apparently inhibit COX-2. Particularly, S4 inhibits COX-2 in vitro and shows a potent anti-inflammatory effect in vivo without cytotoxicity. Molecular docking analyses revealed that S4 interacted satisfactorily with the active site of COX-2 but not with that of COX-1. This reveals that S4 more specifically inhibits COX-2 and has potential for application in developing anti-inflammatory and anticancer agents.

  15. Inhibition of histone deacetylase by butyrate protects rat liver from ischemic reperfusion injury.

    PubMed

    Sun, Jie; Wu, Qiujv; Sun, Huiling; Qiao, Yingli

    2014-11-14

    We showed previously that pretreatment of butyrate, which is an endogenous histone deacetylase (HDAC) inhibitor normally fermented from undigested fiber by intestinal microflora, seriously alleviated ischemia reperfusion (I/R)-induced liver injury by inhibiting the nuclear factor κB (NF-κB) pathway. The goal of this study was to investigate the effect of butyrate administrated at the onset of ischemia for HDAC inhibition in hepatic I/R injury. Sprague Dawley rats were subjected to warm ischemia for 60 min followed by 6 and 24 h of reperfusion. Butyrate was administrated at the onset of ischemia. Liver injury was evaluated by serum levels of aminotransferase, inflammatory factors, and histopathology. The levels of acetylated histone H3 and expression of heat shock protein (Hsp) 70 were measured by Western blot. After reperfusion, the levels of acetylated histone H3 significantly decreased. Butyrate treatment markedly prevented the reduction of acetylated histone H3 and upregulated the expression of Hsp70, thereby reducing liver injury. Our study demonstrated that I/R resulted in marked reduction of histone acetylation; butyrate exerted a great hepatoprotective effect through HDAC inhibition and Hsp70 induction.

  16. Chk1 protects against chromatin bridges by constitutively phosphorylating BLM serine 502 to inhibit BLM degradation.

    PubMed

    Petsalaki, Eleni; Dandoulaki, Maria; Morrice, Nick; Zachos, George

    2014-09-15

    Chromatin bridges represent incompletely segregated chromosomal DNA connecting the anaphase poles and can result in chromosome breakage. The Bloom's syndrome protein helicase (BLM, also known as BLMH) suppresses formation of chromatin bridges. Here, we show that cells deficient in checkpoint kinase 1 (Chk1, also known as CHEK1) exhibit higher frequency of chromatin bridges and reduced BLM protein levels compared to controls. Chk1 inhibition leads to BLM ubiquitylation and proteasomal degradation during interphase. Furthermore, Chk1 constitutively phosphorylates human BLM at serine 502 (S502) and phosphorylated BLM localises to chromatin bridges. Mutation of S502 to a non-phosphorylatable alanine residue (BLM-S502A) reduces the stability of BLM, whereas expression of a phospho-mimicking BLM-S502D, in which S502 is mutated to aspartic acid, stabilises BLM and prevents chromatin bridges in Chk1-deficient cells. In addition, wild-type but not BLM-S502D associates with cullin 3, and cullin 3 depletion rescues BLM accumulation and localisation to chromatin bridges after Chk1 inhibition. We propose that Chk1 phosphorylates BLM-S502 to inhibit cullin-3-mediated BLM degradation during interphase. These results suggest that Chk1 prevents deleterious anaphase bridges by stabilising BLM.

  17. Temporal mTOR inhibition protects Fbxw7-deficient mice from radiation-induced tumor development

    PubMed Central

    Liu, Yueyong; Huang, Yurong; Wang, Zeran; Huang, Yong; Li, Xiaohua; Louie, Alexander; Wei, Guangwei; Mao, Jian-Hua

    2013-01-01

    FBXW7 acts as a tumor suppressor in numerous types of human cancers through ubiquitination of different oncoproteins including mTOR. However, how the mutation/loss of Fbxw7 results in tumor development remains largely unknown. Here we report that downregulation of mTOR by radiation is Fbxw7-dependent, and short-term mTOR inhibition by rapamycin after exposure to radiation significantly postpones tumor development in Fbxw7/p53 double heterozygous (Fbxw7+/−p53+/−) mice but not in p53 single heterozygous (p53+/−) mice. Tumor latency of rapamycin treated Fbxw7+/−p53+/− mice is remarkably similar to those of p53+/− mice while placebo treated Fbxw7+/−p53+/− mice develop tumor significantly earlier than placebo treated p53+/− mice. Furthermore, we surprisingly find that, although temporal treatment of rapamycin is given at a young age, the inhibition of mTOR activity sustainably remains in tumors. These results indicate that inhibition of mTOR signaling pathway suppresses the contribution of Fbxw7 loss toward tumor development. PMID:23454868

  18. Puerarin protects mouse liver against nickel-induced oxidative stress and inflammation associated with the TLR4/p38/CREB pathway.

    PubMed

    Liu, Chan-Min; Ma, Jie-Qiong; Liu, Si-Si; Feng, Zhao-Jun; Wang, Ai-Min

    2016-01-01

    Nickel (Ni), one of hazardous environmental chemicals, is known to cause liver injury. Accumulating evidence showed that puerarin (PU) possessed comprehensive biological effects. The purpose of the current study was to test the hypothesis that the puerarin protects against enhanced liver injury caused by Ni in mice. ICR mice received intraperitoneally nickel sulfate (20 mg/kg/body weight, daily) for 20 days, and puerarin (200 and 400 mg/kg/body weight) was applied before Ni exposure. The results indicated that puerarin markedly inhibited Ni-induced liver injury, which was characterized by decreased aminotransferase activities and inflammation. Puerarin also inhibited the oxidative stress and decreased the metallothionein (MT) levels. Puerarin decreased the level of pro-inflammatory cytokines TNF-α and IL-6 in livers. Puerarin significantly inhibited the TLR4 activation and p38 MAPK phosphorylation, which in turn inhibited NF-κB activity. Likewise, Ni-induced inflammatory responses were diminished by puerarin as observed by a remarkable reduction in the levels of phosphorylated CREB. Furthermore, puerarin also reduced inflammatory mediators such as cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2) levels in livers. Data from this study suggested that the inhibition of Ni-induced oxidative stress and inflammatory responses by puerarin is due to its ability to modulate the TLR4/p38/CREB signaling pathway.

  19. cAMP-Inhibits Cytoplasmic Phospholipase A₂ and Protects Neurons against Amyloid-β-Induced Synapse Damage.

    PubMed

    Bate, Clive; Williams, Alun

    2015-01-01

    A key event in Alzheimer's disease (AD) is the production of amyloid-β (Aβ) peptides and the loss of synapses. In cultured neurons Aβ triggered synapse damage as measured by the loss of synaptic proteins. α-synuclein (αSN), aggregates of which accumulate in Parkinson's disease, also caused synapse damage. Synapse damage was associated with activation of cytoplasmic phospholipase A₂ (cPLA₂), an enzyme that regulates synapse function and structure, and the production of prostaglandin (PG) E₂. In synaptosomes PGE₂ increased concentrations of cyclic adenosine monophosphate (cAMP) which suppressed the activation of cPLA₂ demonstrating an inhibitory feedback system. Thus, Aβ/αSN-induced activated cPLA₂ produces PGE₂ which increases cAMP which in turn suppresses cPLA₂ and, hence, its own production. Neurons pre-treated with pentoxifylline and caffeine (broad spectrum phosphodiesterase (PDE) inhibitors) or the PDE4 specific inhibitor rolipram significantly increased the Aβ/αSN-induced increase in cAMP and consequently protected neurons against synapse damage. The addition of cAMP analogues also inhibited cPLA₂ and protected neurons against synapse damage. These results suggest that drugs that inhibit Aβ-induced activation of cPLA₂ and cross the blood-brain barrier may reduce synapse damage in AD. PMID:26389963

  20. cAMP-Inhibits Cytoplasmic Phospholipase A2 and Protects Neurons against Amyloid-β-Induced Synapse Damage

    PubMed Central

    Bate, Clive; Williams, Alun

    2015-01-01

    A key event in Alzheimer’s disease (AD) is the production of amyloid-β (Aβ) peptides and the loss of synapses. In cultured neurons Aβ triggered synapse damage as measured by the loss of synaptic proteins. α-synuclein (αSN), aggregates of which accumulate in Parkinson’s disease, also caused synapse damage. Synapse damage was associated with activation of cytoplasmic phospholipase A2 (cPLA2), an enzyme that regulates synapse function and structure, and the production of prostaglandin (PG) E2. In synaptosomes PGE2 increased concentrations of cyclic adenosine monophosphate (cAMP) which suppressed the activation of cPLA2 demonstrating an inhibitory feedback system. Thus, Aβ/αSN-induced activated cPLA2 produces PGE2 which increases cAMP which in turn suppresses cPLA2 and, hence, its own production. Neurons pre-treated with pentoxifylline and caffeine (broad spectrum phosphodiesterase (PDE) inhibitors) or the PDE4 specific inhibitor rolipram significantly increased the Aβ/αSN-induced increase in cAMP and consequently protected neurons against synapse damage. The addition of cAMP analogues also inhibited cPLA2 and protected neurons against synapse damage. These results suggest that drugs that inhibit Aβ-induced activation of cPLA2 and cross the blood–brain barrier may reduce synapse damage in AD. PMID:26389963

  1. HIF prolyl 4-hydroxylase-2 inhibition improves glucose and lipid metabolism and protects against obesity and metabolic dysfunction.

    PubMed

    Rahtu-Korpela, Lea; Karsikas, Sara; Hörkkö, Sohvi; Blanco Sequeiros, Roberto; Lammentausta, Eveliina; Mäkelä, Kari A; Herzig, Karl-Heinz; Walkinshaw, Gail; Kivirikko, Kari I; Myllyharju, Johanna; Serpi, Raisa; Koivunen, Peppi

    2014-10-01

    Obesity is a major public health problem, predisposing subjects to metabolic syndrome, type 2 diabetes, and cardiovascular diseases. Specific prolyl 4-hydroxylases (P4Hs) regulate the stability of the hypoxia-inducible factor (HIF), a potent governor of metabolism, with isoenzyme 2 being the main regulator. We investigated whether HIF-P4H-2 inhibition could be used to treat obesity and its consequences. Hif-p4h-2-deficient mice, whether fed normal chow or a high-fat diet, had less adipose tissue, smaller adipocytes, and less adipose tissue inflammation than their littermates. They also had improved glucose tolerance and insulin sensitivity. Furthermore, the mRNA levels of the HIF-1 targets glucose transporters, glycolytic enzymes, and pyruvate dehydrogenase kinase-1 were increased in their tissues, whereas acetyl-CoA concentration was decreased. The hepatic mRNA level of the HIF-2 target insulin receptor substrate-2 was higher, whereas that of two key enzymes of fatty acid synthesis was lower. Serum cholesterol levels and de novo lipid synthesis were decreased, and the mice were protected against hepatic steatosis. Oral administration of an HIF-P4H inhibitor, FG-4497, to wild-type mice with metabolic dysfunction phenocopied these beneficial effects. HIF-P4H-2 inhibition may be a novel therapy that not only protects against the development of obesity and its consequences but also reverses these conditions.

  2. PKC{eta} confers protection against apoptosis by inhibiting the pro-apoptotic JNK activity in MCF-7 cells

    SciTech Connect

    Rotem-Dai, Noa; Oberkovitz, Galia; Abu-Ghanem, Sara; Livneh, Etta

    2009-09-10

    Apoptosis is frequently regulated by different protein kinases including protein kinase C family enzymes. Both inhibitory and stimulatory effects were demonstrated for several of the different PKC isoforms. Here we show that the novel PKC isoform, PKC{eta}, confers protection against apoptosis induced by the DNA damaging agents, UVC irradiation and the anti-cancer drug - Camptothecin, of the breast epithelial adenocarcinoma MCF-7 cells. The induced expression of PKC{eta} in MCF-7 cells, under the control of the tetracycline-responsive promoter, resulted in increased cell survival and inhibition of cleavage of the apoptotic marker PARP-1. Activation of caspase-7 and 9 and the release of cytochrome c were also inhibited by the inducible expression of PKC{eta}. Furthermore, JNK activity, required for apoptosis in MCF-7, as indicated by the inhibition of both caspase-7 cleavage and cytochrome c release from the mitochondria in the presence of the JNK inhibitor SP600125, was also suppressed by PKC{eta} expression. Hence, in contrast to most PKC isoforms enhancing JNK activation, our studies show that PKC{eta} is an anti-apoptotic protein, acting as a negative regulator of JNK activity. Thus, PKC{eta} could represent a target for intervention aimed to reduce resistance to anti-cancer treatments.

  3. Identification of small molecules that inhibit the interaction of TEM8 with anthrax protective antigen using a FRET assay.

    PubMed

    Cryan, Lorna M; Habeshian, Kaiane A; Caldwell, Thomas P; Morris, Meredith T; Ackroyd, P Christine; Christensen, Kenneth A; Rogers, Michael S

    2013-07-01

    Tumor marker endothelial 8 (TEM8) is a receptor for the protective antigen (PA) component of anthrax toxin. TEM8 is upregulated on endothelial cells lining the blood vessels within tumors, compared with normal blood vessels. A number of studies have demonstrated a pivotal role for TEM8 in developmental and tumor angiogenesis. We have also shown that targeting the anthrax receptors with a mutated form of PA inhibits angiogenesis and tumor formation in vivo. Here we describe the development and testing of a high-throughput fluorescence resonance energy transfer assay to identify molecules that strongly inhibit the interaction of PA and TEM8. The assay we describe is sensitive and robust, with a Z' value of 0.8. A preliminary screen of 2310 known bioactive library compounds identified ebselen and thimerosal as inhibitors of the TEM8-PA interaction. These molecules each contain a cysteine-reactive transition metal, and complementary studies indicate that their inhibition of interaction is due to modification of a cysteine residue in the TEM8 extracellular domain. This is the first demonstration of a high-throughput screening assay that identifies inhibitors of TEM8, with potential application for antianthrax and antiangiogenic diseases.

  4. Oxymatrine protects against myocardial injury via inhibition of JAK2/STAT3 signaling in rat septic shock.

    PubMed

    Zhang, Minghao; Wang, Xiuyu; Wang, Xiumei; Hou, Xiaolin; Teng, Peng; Jiang, Yideng; Zhang, Linna; Yang, Xiaoling; Tian, Jue; Li, Guizhong; Cao, Jun; Xu, Hua; Li, Yunhong; Wang, Yin

    2013-04-01

    Oxymatrine (OMT), an alkaloid extracted from Sophora japonica (kushen), is used to treat inflammatory diseases and various types of cancer in traditional Chinese medicine. However, the cellular and molecular mechanisms underlying the anti‑inflammatory activity of OMT remain poorly understood. The present study explored the protective effect of OMT on myocardial injury in rats with septic shock by inhibiting the activation of the janus kinase‑signal transducer and activator of transcription (JAK/STAT) signaling pathway. OMT treatment was found to significantly inhibit the activation of JAK2 and STAT3 in myocardial tissue. It also attenuated the expression of pro‑inflammatory cytokines, including interleukin‑1β and tumor necrosis factor‑α. In addition, OMT exhibited anti‑inflammatory properties as heart function and myocardial contractility was improved and pathological and ultrastructural injury was prevented in myocardial tissue induced by septic shock. The results indicate that OMT exhibits substantial therapeutic potential for the treatment of septic shock‑induced myocardial injury through inhibition of the JAK2/STAT3 signaling pathway. PMID:23404057

  5. p53 inhibition provides a pivotal protective effect against ischemia-reperfusion injury in vitro via mTOR signaling.

    PubMed

    Li, Xiaomu; Gu, Shixin; Ling, Yan; Shen, Chao; Cao, Xiaoyun; Xie, Rong

    2015-04-24

    Tumor suppressor p53 has recently been reported to have numerous functions independent of tumorigenesis, including neuronal survival during ischemia. The mammalian target of rapamycin (mTOR) signaling pathway plays a central role in the regulation of metabolism, cell growth, development, and cell survival. Our recent work has demonstrated the neuroprotective effects of the mTOR pathway. Considering that p53 is also an important regulator of mTOR, to further clarify the role of p53 and the mTOR signaling pathway in neuronal ischemic-reperfusion injury, we used mouse primary mixed cultured neurons with an oxygen glucose deprivation (OGD) model to mimic an ischemic-reperfusion injury in vitro. A lentiviral system was also used to inhibit or overexpress p53 to determine whether p53 alteration affects OGD and reperfusion injury. Our results show that activated p53 was induced and it suppressed mTOR expression in primary mixed cultured neurons after OGD and reperfusion. Inhibiting p53, using either a chemical inhibitor or lentiviral-mediated shRNA, exhibited neuroprotective effects in primary cultured neurons against OGD and reperfusion injury through the upregulation of mTOR activity. Such protective effects could be reversed by rapamycin, an mTOR inhibitor. Conversely, p53 overexpression tended to exacerbate the detrimental effects of OGD injury by downregulating mTOR activity. These results suggest that p53 inhibition has a pivotal protective effect against an in vitro ischemia-reperfusion injury via mTOR signaling and provides a potential and promising therapeutic target for stroke treatment. PMID:25681550

  6. Distribution and time-course of 4-hydroxynonenal, heat shock protein 110/105 family members and cyclooxygenase-2 expression in the hippocampus of rat during trimethyltin-induced neurodegeneration.

    PubMed

    Corvino, V; Marchese, E; Zarkovic, N; Zarkovic, K; Cindric, M; Waeg, G; Michetti, F; Geloso, M C

    2011-08-01

    Trimethyltin (TMT), an organotin compound considered a useful tool to obtain an experimental model of neurodegeneration, exhibits neurotoxicant effects selectively localised in the limbic system and especially in the hippocampus, which are different in the rat and in mice. In the rat hippocampus, we investigated the expression of aldehyde 4-hydroxynonenal, a major bioactive marker of membrane lipid peroxidation, heat shock protein (HSP) 110/105 family members, markers of oxidative stress, and the neuroinflammatory marker cyclooxygenase-2 after TMT-intoxication at various time points after treatment. Our data show that TMT-induced neurodegeneration in the rat hippocampus is associated specifically with oxidative stress and lipid peroxidation, but not with HSP expression, indicating species-specific differences in the neurotoxicity of TMT between rats and mice.

  7. Protective effects of berberine against doxorubicin-induced cardiotoxicity in rats by inhibiting metabolism of doxorubicin.

    PubMed

    Hao, Gang; Yu, Yunli; Gu, Bingren; Xing, Yiwen; Xue, Man

    2015-01-01

    1. The clinical use of doxorubicin, an effective anticancer drug, is severely hampered by its cardiotoxicity. Berberine, a botanical alkaloid, has been reported to possess cardioprotective and antitumor effects. In this study, we investigated the cardioprotective effect of berberine on doxorubicin-induced cardiotoxicity and the effect of berberine on the metabolism of doxorubicin. 2. Adult male Sprague-Dawley rats were administered doxorubicin in the presence or absence of berberine for 2 weeks. Administration of berberine effectively prevented doxorubicin-induced body weight reduction and mortality in rats. 3. Berberine reduced the activity of myocardial enzymes, including aspartate aminotransferase (AST), creatine kinase (CK), CK isoenzyme (CK-MB) and lactate dehydrogenase (LDH). Echocardiographic examination further demonstrated that berberine effectively ameliorated cardiac dysfunction induced by doxorubicin. 4. Berberine inhibited the metabolism of doxorubicin in the cytoplasm of rat heart and reduced the accumulation of doxorubicinol (a secondary alcohol metabolite of doxorubicin) in heart. 5. These data showed that berberine alleviated the doxorubicin-induced cardiotoxicity in rats via inhibition of the metabolism of doxorubicin and reduced accumulation of doxorubicinol selectively in hearts.

  8. Micheliolide inhibits LPS-induced inflammatory response and protects mice from LPS challenge

    PubMed Central

    Qin, Xiangyang; Jiang, Xinru; Jiang, Xin; Wang, Yuli; Miao, Zhulei; He, Weigang; Yang, Guizhen; Lv, Zhenhui; Yu, Yizhi; Zheng, Yuejuan

    2016-01-01

    Sepsis is the principal cause of fatality in the intensive care units worldwide. It involves uncontrolled inflammatory response resulting in multi-organ failure and even death. Micheliolide (MCL), a sesquiterpene lactone, was reported to inhibit dextran sodium sulphate (DSS)-induced inflammatory intestinal disease, colitis-associated cancer and rheumatic arthritis. Nevertheless, the role of MCL in microbial infection and sepsis is unclear. We demonstrated that MCL decreased lipopolysaccharide (LPS, the main cell wall component of Gram-negative bacteria)-mediated production of cytokines (IL-6, TNF-α, MCP-1, etc) in Raw264.7 cells, primary macrophages, dendritic cells and human monocytes. MCL plays an anti-inflammatory role by inhibiting LPS-induced activation of NF-κB and PI3K/Akt/p70S6K pathways. It has negligible impact on the activation of mitogen-activated protein kinase (MAPK) pathways. In the acute peritonitis mouse model, MCL reduced the secretion of IL-6, TNF-α, IL-1β, MCP-1, IFN-β and IL-10 in sera, and ameliorated lung and liver damage. MCL down-regulated the high mortality rate caused by lethal LPS challenge. Collectively, our data illustrated that MCL enabled maintenance of immune equilibrium may represent a potentially new anti-inflammatory and immunosuppressive drug candidate in the treatment of sepsis and septic shock. PMID:26984741

  9. A novel pyrazole derivative protects from ovariectomy-induced osteoporosis through the inhibition of NADPH oxidase

    PubMed Central

    Joo, Jung Hee; Huh, Jeong-Eun; Lee, Jee Hyun; Park, Doo Ri; Lee, Yoonji; Lee, Seul Gee; Choi, Sun; Lee, Hwa Jeong; Song, Seong-Won; Jeong, Yongmi; Goo, Ja-Il; Choi, Yongseok; Baek, Hye Kyung; Yi, Sun Shin; Park, Soo Jin; Lee, Ji Eun; Ku, Sae Kwang; Lee, Won Jae; Lee, Kee-In; Lee, Soo Young; Bae, Yun Soo

    2016-01-01

    Osteoclast cells (OCs) are differentiated from bone marrow-derived macrophages (BMMs) by activation of receptor activator of nuclear factor κB (NF-κB) ligand (RANKL). Activation of NADPH oxidase (Nox) isozymes is involved in RANKL-dependent OC differentiation, implicating Nox isozymes as therapeutic targets for treatment of osteoporosis. Here, we show that a novel pyrazole derivative, Ewha-18278 has high inhibitory potency on Nox isozymes. Blocking the activity of Nox with Ewha-18278 inhibited the responses of BMMs to RANKL, including reactive oxygen species (ROS) generation, activation of mitogen-activated protein (MAP) kinases and NF-κB, and OC differentiation. To evaluate the anti-osteoporotic function of Ewha-18278, the derivative was applied to estrogen-deficient ovariectomized (OVX) ddY mice. Oral administration of Ewha-18278 (10 mg/kg/daily, 4 weeks) into the mice recovered bone mineral density, trabecular bone volume, trabecular bone length, number and thickness, compared to control OVX ddY mice. Moreover, treatment of OVX ddY mice with Ewha-18278 increased bone strength by increasing cortical bone thickness. We provide that Ewha-18278 displayed Nox inhibition and blocked the RANKL-dependent cell signaling cascade leading to reduced differentiation of OCs. Our results implicate Ewha-18278 as a novel therapeutic agent for the treatment of osteoporosis. PMID:26975635

  10. Punicic Acid a Conjugated Linolenic Acid Inhibits TNFα-Induced Neutrophil Hyperactivation and Protects from Experimental Colon Inflammation in Rats

    PubMed Central

    Boussetta, Tarek; Raad, Houssam; Lettéron, Philippe; Gougerot-Pocidalo, Marie-Anne; Marie, Jean-Claude

    2009-01-01

    Background Neutrophils play a major role in inflammation by releasing large amounts of ROS produced by NADPH-oxidase and myeloperoxidase (MPO). The proinflammatory cytokine TNFα primes ROS production through phosphorylation of the NADPH-oxidase subunit p47phox on Ser345. Conventional anti-inflammatory therapies remain partially successful and may have side effects. Therefore, regulation of neutrophil activation by natural dietary components represents an alternative therapeutic strategy in inflammatory diseases such as inflammatory bowel diseases. The aim of this study was to assess the effect of punicic acid, a conjugated linolenic fatty acid from pomegranate seed oil on TNFα-induced neutrophil hyperactivation in vitro and on colon inflammation in vivo. Methodology and Principal Findings We analyzed the effect of punicic acid on TNFα-induced neutrophil upregulation of ROS production in vitro and on TNBS-induced rat colon inflammation. Results show that punicic acid inhibited TNFα-induced priming of ROS production in vitro while preserving formyl-methionyl-leucyl-phenylalanine (fMLP)-induced response. This effect was mediated by the inhibition of Ser345-p47phox phosphorylation and upstream kinase p38MAPK. Punicic acid also inhibited fMLP- and TNFα+fMLP-induced MPO extracellular release from neutrophils. In vivo experiments showed that punicic acid and pomegranate seed oil intake decreased neutrophil-activation and ROS/MPO-mediated tissue damage as measured by F2-isoprostane release and protected rats from TNBS-induced colon inflammation. Conclusions/Significance These data show that punicic acid exerts a potent anti-inflammatory effect through inhibition of TNFα-induced priming of NADPH oxidase by targeting the p38MAPKinase/Ser345-p47phox-axis and MPO release. This natural dietary compound may provide a novel alternative therapeutic strategy in inflammatory diseases such as inflammatory bowel diseases. PMID:19649246

  11. Inhibition of the iron-catalysed formation of hydroxyl radicals by nitrosouracil derivatives: protection of mitochondrial membranes against lipid peroxidation.

    PubMed

    Rabion, A; Verlhac, J B; Fraisse, L; Roche, B; Seris, J L

    1993-01-01

    A new series of metal ligands containing the 1,3-dimethyl-6-amino-5- nitrosouracil moiety has been synthesized and they have been studied as potential inhibitors of iron-dependent lipid peroxidation. For this purpose, these new derivatives have been tested in the Fenton induced deoxyribose degradation assay, which allows a quantitative measurement of their inhibitory effect towards hydroxyl radical generation. When iron(II) is complexed by these ligands, a strong inhibition of deoxyribose degradation is observed, especially in the case of tris-[2-(1,3-dimethyl-5-nitrosouracil-6-yl)aminoethyl] amine (5). This inhibitory effect is clearly related to a specific complexation of iron(II) and is not due to the direct scavenging of hydroxyl radical by the ligand. Inhibition of the iron mediated Fenton reaction presumably results from inactivation of the reactivity of the metal center towards hydrogen peroxide. These derivatives, as well as long alkyl chain substituted nitrosouracils were evaluated in the protection of biological membranes against lipid peroxidation (induced by iron(II)/dihydroxyfumaric acid and determined with the 2-thiobarbituric acid test). Ligand 5 inhibited lipid peroxidation at a rate similar to Desferal (desferrioxamine B) and slightly higher than bathophenanthroline sulphonate (BPS), which are respectively good iron(III) and iron(II) chelators. When covalently bound with a long alkyl chain, the increase of lipophilic character of the ligand allows its location near the mitochondrial membrane, where lipid peroxidation occurs. Lower concentrations (IC50 = 4 microM) are then necessary to inhibit lipid peroxidation. This IC50 concentration should be compared to those obtained for Trolox (IC50 = 3 microM) or the 21-aminosteroid U74500A (IC50 = 1 microM) described previously.

  12. Mesenchymal stem cells protect CNS neurons against glutamate excitotoxicity by inhibiting glutamate receptor expression and function.

    PubMed

    Voulgari-Kokota, A; Fairless, R; Karamita, M; Kyrargyri, V; Tseveleki, V; Evangelidou, M; Delorme, B; Charbord, P; Diem, R; Probert, L

    2012-07-01

    Mesenchymal stem cells (MSC) promote functional recovery in experimental models of central nervous system (CNS) pathology and are currently being tested in clinical trials for stroke, multiple sclerosis and CNS injury. Their beneficial effects are attributed to the activation of endogenous CNS protection and repair processes as well as immune regulation but their mechanisms of action are poorly understood. Here we investigated the neuroprotective effects of mouse MSC in rodent MSC-neuron co-cultures and mice using models of glutamate excitotoxicity. A 24h pre-culture of mouse primary cortical neurons with MSC protected them against glutamate (NMDA) receptor-induced death and conditioned medium from MSC (MSC CM) was sufficient for this effect. Protection by MSC CM was associated with reduced mRNA levels of genes encoding NMDA receptor subunits, and increased levels for genes associated with non-neuronal and stem cell types, as shown by RT-PCR and cDNA microarray analyses. Changes in gene expression were not associated with alterations in cell lineage representation within the cultures. Further, MSC CM-mediated neuroprotection in rat retinal ganglion cells was associated with reduced glutamate-induced calcium influx. The adoptive transfer of EGFP(+)MSC in a mouse kainic acid epilepsy model also provided neuroprotection against glutamate excitotoxicity in vivo, as shown by reduced neuron damage and glial cell activation in the hippocampus. These results show that MSC mediate direct neuroprotection by reducing neuronal sensitivity to glutamate receptor ligands and altering gene expression, and suggest a link between the therapeutic effects of MSC and the activation of cell plasticity in the damaged CNS. PMID:22561409

  13. Stimulation or Inhibition: Conflicting evidence for (+/-)-catechin's role as a chemical facilitator and disease protecting agent.

    PubMed

    Bais, Harsh P; Venkatachalam, L; Biedrzycki, Meredith L

    2010-03-01

    The occurrence of plant hormesis is a poorly understood phenomenon, wherein low doses of phytotoxins unusually promote growth responses in higher plants. In contrast, negative plant-plant interactions mediated through secreted small molecular weight compounds initiate growth inhibitory responses. Studies related to (+/-)-catechin mediated allelopathy have transpired both novel information and generated significant controversy. Specifically, studies related to the phytotoxicity responses mediated by (+/-)-catechins have been seriously debated. The pronged opinion that (+/-)-catechin is phytotoxic versus non-phytotoxic relies more on the target plant systems and the conditions used to test phytotoxic responses. It is reported that lower than MIC dosage supplementation of (+/-)-catechin could promote growth responses in the model plant Arabidopsis thaliana. Furthermore, it was shown that sub-MIC levels of (+/-)-catechin supplementation leads to elicitation of disease resistance against Pseudomonas syringae DC3000 (hereafter DC3000). Intrigued by the unique hormesis response observed, we tested whether (+/-)-catechin indeed promotes growth responses in A. thaliana. In our hands, we observed no growth promotion responses of (+/-)-catechin against A. thaliana under in vitro or in soil conditions. We also evaluated the previously reported disease protecting properties of (+/-)-catechin in A. thaliana against DC3000. The systematic observations to evaluate disease protecting properties entailing colony counts, disease incidences and loss of chlorophyll studies showed no disease protecting properties of (+/-)-catechin. The transcriptional response for a marker pathogenesis related PR1 defense gene showed no induction post (+/-)-catechin supplementation. The cell death genes (ACD2 and CAD1) associated with programmed cell death revealed unchanged expression levels in plants treated with sub-MIC levels of (+/-)-catechin. Further, we report supplementation of sub-MIC levels of

  14. Inhibition of enzymatic browning and protection of sulfhydryl enzymes by thiol compounds.

    PubMed

    Negishi, O; Ozawa, T

    2000-06-01

    In a reaction between (-)-epicatechin (EC) and 2-mercaptoethanol (2ME), catalyzed by partially purified polyphenol oxidase (PPO) extracted from the style of Rhododendron mucronatum, 2'-(2-hydroxyethylthio)-(-)-epicatechin (2'-HETEC), 5'-(2-hydroxyethylthio)-(-)-epicatechin (5'-HETEC), and 2',5'-bis(2-hydroxyethylthio)-(-)-epicatechin (2',5'-HETEC) were formed. The rate of formation of 2',5'-HETEC from 5'-HETEC was faster than that from 2'-HETEC. In the absence of 2ME, the concentration of EC decreased rapidly and the reaction mixture turned brown; 2'-, 5'-, and 2',5'-HETEC, especially 2'-substituted HETECs. reacted more slowly. These data indicate that 2ME acts both as an inhibitor of the polymerization of O-quinone, presumably by binding to it and as a reductant involved in the conversion of O-quinone to O-dihydroxyphenol, Inhibition of enzymatic browning by other thiol compounds such as cysteine and dithiothreitol was also investigated.

  15. Prolactin protects retinal pigment epithelium by inhibiting sirtuin 2-dependent cell death.

    PubMed

    Meléndez García, Rodrigo; Arredondo Zamarripa, David; Arnold, Edith; Ruiz-Herrera, Xarubet; Noguez Imm, Ramsés; Baeza Cruz, German; Adán, Norma; Binart, Nadine; Riesgo-Escovar, Juan; Goffin, Vincent; Ordaz, Benito; Peña-Ortega, Fernando; Martínez-Torres, Ataúlfo; Clapp, Carmen; Thebault, Stéphanie

    2016-05-01

    The identification of pathways necessary for retinal pigment epithelium (RPE) function is fundamental to uncover therapies for blindness. Prolactin (PRL) receptors are expressed in the retina, but nothing is known about the role of PRL in RPE. Using the adult RPE 19 (ARPE-19) human cell line and mouse RPE, we identified the presence of PRL receptors and demonstrated that PRL is necessary for RPE cell survival via anti-apoptotic and antioxidant actions. PRL promotes the antioxidant capacity of ARPE-19 cells by reducing glutathione. It also blocks the hydrogen peroxide-induced increase in deacetylase sirtuin 2 (SIRT2) expression, which inhibits the TRPM2-mediated intracellular Ca(2+) rise associated with reduced survival under oxidant conditions. RPE from PRL receptor-null (prlr(-/-)) mice showed increased levels of oxidative stress, Sirt2 expression and apoptosis, effects that were exacerbated in animals with advancing age. These observations identify PRL as a regulator of RPE homeostasis.

  16. The Glucotoxicity Protecting Effect of Ezetimibe in Pancreatic Beta Cells via Inhibition of CD36

    PubMed Central

    2016-01-01

    Inhibition of CD36, a fatty acid transporter, has been reported to prevent glucotoxicity and ameliorate high glucose induced beta cell dysfunction. Ezetimibe is a selective cholesterol absorption inhibitor that blocks Niemann Pick C1-like 1 protein, but may exert its effect through suppression of CD36. We attempted to clarify the beneficial effect of ezetimibe on insulin secreting cells and to determine whether this effect is related to change of CD36 expression. mRNA expression of insulin and CD36, intracellular peroxide level and glucose stimulated insulin secretion (GSIS) under normal (5.6 mM) or high glucose (30 mM) condition in INS-1 cells and primary rat islet cells were compared. Changes of the aforementioned factors with treatment with ezetimibe (20 μM) under normal or high glucose condition were also assessed. mRNA expression of insulin was decreased with high glucose, which was reversed by ezetimibe in both INS-1 cells and primary rat islets. CD36 mRNA expression was increased with high glucose, but decreased by ezetimibe in INS-1 cells and primary rat islets. Three-day treatment with high glucose resulted in an increase in intracellular peroxide level; however, it was decreased by treatment with ezetimibe. Decrease in GSIS by three-day treatment with high glucose was reversed by ezetimibe. Palmitate uptake following exposure to high glucose conditions for three days was significantly elevated, which was reversed by ezetimibe in INS-1 cells. Ezetimibe may prevent glucotoxicity in pancreatic β-cells through a decrease in fatty acid influx via inhibition of CD36. PMID:27051238

  17. Inhibition of KV7 Channels Protects the Rat Heart against Myocardial Ischemia and Reperfusion Injury.

    PubMed

    Hedegaard, Elise R; Johnsen, Jacob; Povlsen, Jonas A; Jespersen, Nichlas R; Shanmuganathan, Jeffrey A; Laursen, Mia R; Kristiansen, Steen B; Simonsen, Ulf; Bøtker, Hans Erik

    2016-04-01

    The voltage-gated KV7 (KCNQ) potassium channels are activated by ischemia and involved in hypoxic vasodilatation. We investigated the effect of KV7 channel modulation on cardiac ischemia and reperfusion injury and its interaction with cardioprotection by ischemic preconditioning (IPC). Reverse-transcription polymerase chain reaction revealed expression of KV7.1, KV7.4, and KV7.5 in the left anterior descending rat coronary artery and all KV7 subtypes (KV7.1-KV7.5) in the left and right ventricles of the heart. Isolated hearts were subjected to no-flow global ischemia and reperfusion with and without IPC. Infarct size was quantified by 2,3,5-triphenyltetrazolium chloride staining. Two blockers of KV7 channels, XE991 [10,10-bis(4-pyridinylmethyl)-9(10H)-anthracenone] (10 µM) and linopirdine (10 µM), reduced infarct size and exerted additive infarct reduction to IPC. An opener of KV7 channels, flupirtine (10 µM) abolished infarct size reduction by IPC. Hemodynamics were measured using a catheter inserted in the left ventricle and postischemic left ventricular recovery improved in accordance with reduction of infarct size and deteriorated with increased infarct size. XE991 (10 µM) reduced coronary flow in the reperfusion phase and inhibited vasodilatation in isolated small branches of the left anterior descending coronary artery during both simulated ischemia and reoxygenation. KV7 channels are expressed in rat coronary arteries and myocardium. Inhibition of KV7 channels exerts cardioprotection and opening of KV7 channels abrogates cardioprotection by IPC. Although safety issues should be further addressed, our findings suggest a potential role for KV7 blockers in the treatment of ischemia-reperfusion injury. PMID:26869667

  18. Trichostatin A Protects Liver against Septic Injury through Inhibiting Toll-Like Receptor Signaling

    PubMed Central

    Kim, So-Jin; Park, Jin-Sook; Lee, Do-Won; Lee, Sun-Mee

    2016-01-01

    Sepsis, a serious clinical problem, is characterized by a systemic inflammatory response to infection and leads to organ failure. Toll-like receptor (TLR) signaling is intimately implicated in hyper-inflammatory responses and tissue injury during sepsis. Histone deacetylase (HDAC) inhibitors have been reported to exhibit anti-inflammatory properties. The aim of this study was to investigate the hepatoprotective mechanisms of trichostatin A (TSA), a HDAC inhibitor, associated with TLR signaling pathway during sepsis. The anti-inflammatory properties of TSA were assayed in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Polymicrobial sepsis was induced in mice by cecal ligation and puncture (CLP), a clinically relevant model of sepsis. The mice were intraperitoneally received TSA (1, 2 or 5 mg/kg) 30 min before CLP. The serum and liver samples were collected 6 and 24-h after CLP. TSA inhibited the increased production of tumor necrosis factor (TNF)-α and interleukin (IL)-6 in LPS-stimulated RAW264.7 cells. TSA improved sepsis-induced mortality, attenuated liver injury and decreased serum TNF-α and IL-6 levels. CLP increased the levels of TLR4, TLR2 and myeloid differentiation primary response protein 88 (MyD88) protein expression and association of MyD88 with TLR4 and TLR2, which were attenuated by TSA. CLP increased nuclear translocation of nuclear factor kappa B and decreased cytosolic inhibitor of kappa B (IκB) protein expression, which were attenuated by TSA. Moreover, CLP decreased acetylation of IκB kinase (IKK) and increased association of IKK with IκB and TSA attenuated these alterations. Our findings suggest that TSA attenuates liver injury by inhibiting TLR-mediated inflammatory response during sepsis. PMID:27068262

  19. Sustained Release of Prostaglandin E2 in Fibroblasts Expressing Ectopically Cyclooxygenase 2 Impairs P2Y-Dependent Ca2+-Mobilization

    PubMed Central

    Pimentel-Santillana, María; Través, Paqui G.; Pérez-Sen, Raquel; Delicado, Esmerilda G.; Martín-Sanz, Paloma; Miras-Portugal, María Teresa; Boscá, Lisardo

    2014-01-01

    The nucleotide uridine trisphosphate (UTP) released to the extracellular milieu acts as a signaling molecule via activation of specific pyrimidine receptors (P2Y). P2Y receptors are G protein-coupled receptors expressed in many cell types. These receptors mediate several cell responses and they are involved in intracellular calcium mobilization. We investigated the role of the prostanoid PGE2 in P2Y signaling in mouse embryonic fibroblasts (MEFs), since these cells are involved in different ontogenic and physiopathological processes, among them is tissue repair following proinflammatory activation. Interestingly, Ca2+-mobilization induced by UTP-dependent P2Y activation was reduced by PGE2 when this prostanoid was produced by MEFs transfected with COX-2 or when PGE2 was added exogenously to the culture medium. This Ca2+-mobilization was important for the activation of different metabolic pathways in fibroblasts. Moreover, inhibition of COX-2 with selective coxibs prevented UTP-dependent P2Y activation in these cells. The inhibition of P2Y responses by PGE2 involves the activation of PKCs and PKD, a response that can be suppressed after pharmacological inhibition of these protein kinases. In addition to this, PGE2 reduces the fibroblast migration induced by P2Y-agonists such as UTP. Taken together, these data demonstrate that PGE2 is involved in the regulation of P2Y signaling in these cells. PMID:25214717

  20. Melatonin-mediated Bim up-regulation and cyclooxygenase-2 (COX-2) down-regulation enhances tunicamycin-induced apoptosis in MDA-MB-231 cells.

    PubMed

    Woo, Seon Min; Min, Kyoung-jin; Kwon, Taeg Kyu

    2015-04-01

    Melatonin is involved in many physiological functions, and it has differential effects on apoptosis in normal and cancer cells. However, the mechanism of its antitumor roles is not well understood. In this study, we show that melatonin enhances tunicamycin-induced apoptosis in human breast carcinoma MDA-MB-231 cells. Melatonin up-regulates pro-apoptotic protein Bim expression at the transcriptional levels in the presence of tunicamycin. Melatonin inhibits tunicamycin-induced COX-2 expression in MDA-MB-231 cells. Furthermore, inhibition of COX-2 activity using the COX-2 inhibitor, NS398, increases tunicamycin-induced apoptosis. Interestingly, these effects were not associated with melatonin receptor signal pathways. Pertussis toxin (a general Gi protein inhibitor) or luzindole (a nonspecific melatonin receptor antagonist) did not reverse the effect of melatonin. In addition, melatonin blocked tunicamycin-induced NF-κB transcriptional activity, p65 nuclear translocation, and p38 MAPK activation. Melatonin-mediated p38 MAPK inhibition contributed to decreased COX-2 mRNA stability. Taken together, our results suggest that melatonin enhances antitumor function through up-regulation of Bim expression and down-regulation of COX-2 expression in tunicamycin-treated MDA-MB-231 cells. PMID:25711465

  1. Structure-activity relationship of novel series of 1,5-disubstituted tetrazoles as cyclooxygenase-2 inhibitors: Design, synthesis, bioassay screening and molecular docking studies.

    PubMed

    Jawabrah Al-Hourani, Baker; Al-Awaida, Wajdy; Matalka, Khalid Z; El-Barghouthi, Musa I; Alsoubani, Fatima; Wuest, Frank

    2016-10-01

    A novel class of modified 1,5-disubstituted tetrazoles was designed and synthesized, their biological activity as cyclooxygenases inhibitors was screened, and their molecular docking studies were performed. The structural modifications of the first category included the 4-methylsulfonyl phenyl at C-1 of the central moiety and the linkers (-OH, -CH2OH, -CH2CH2OH) with different lengths at the para position of the N-1 phenyl group. For the second category, the 4-methylsulfonyl phenyl group at C-1 was replaced with 4-aminosulfonyl phenyl. While for the third category, a methylene unit was inserted between the C-1 of the tetrazole central ring and the 4-(methylsulfonyl)phenyl group, keeping the same linkers of various extensions at the para position of the N-1 phenyl group. Among the screened compounds, tetrazole 4i showed the best inhibition potency and selectivity values for both COX-2 enzyme (IC50=3μM, SI>67) and COX-1 isoenzyme (IC50>200μM). Compounds 4e, 4h, and 4i, which have the highest inhibition potency toward COX-2 were selected for the molecular docking studies to verify their inhibition and selectivity for COX-2 over COX-1 with their modified structure. The obtained theoretical studies are in agreement with the in vitro bioassay screening results, which supports the importance of the structural modifications for our studied compounds. PMID:27567369

  2. Structure-activity relationship of novel series of 1,5-disubstituted tetrazoles as cyclooxygenase-2 inhibitors: Design, synthesis, bioassay screening and molecular docking studies.

    PubMed

    Jawabrah Al-Hourani, Baker; Al-Awaida, Wajdy; Matalka, Khalid Z; El-Barghouthi, Musa I; Alsoubani, Fatima; Wuest, Frank

    2016-10-01

    A novel class of modified 1,5-disubstituted tetrazoles was designed and synthesized, their biological activity as cyclooxygenases inhibitors was screened, and their molecular docking studies were performed. The structural modifications of the first category included the 4-methylsulfonyl phenyl at C-1 of the central moiety and the linkers (-OH, -CH2OH, -CH2CH2OH) with different lengths at the para position of the N-1 phenyl group. For the second category, the 4-methylsulfonyl phenyl group at C-1 was replaced with 4-aminosulfonyl phenyl. While for the third category, a methylene unit was inserted between the C-1 of the tetrazole central ring and the 4-(methylsulfonyl)phenyl group, keeping the same linkers of various extensions at the para position of the N-1 phenyl group. Among the screened compounds, tetrazole 4i showed the best inhibition potency and selectivity values for both COX-2 enzyme (IC50=3μM, SI>67) and COX-1 isoenzyme (IC50>200μM). Compounds 4e, 4h, and 4i, which have the highest inhibition potency toward COX-2 were selected for the molecular docking studies to verify their inhibition and selectivity for COX-2 over COX-1 with their modified structure. The obtained theoretical studies are in agreement with the in vitro bioassay screening results, which supports the importance of the structural modifications for our studied compounds.

  3. Protection of the Transplant Kidney from Preservation Injury by Inhibition of Matrix Metalloproteinases

    PubMed Central

    Arcand, Steve; Lin, Han-Bin; Wojnarowicz, Chris; Sawicka, Jolanta; Banerjee, Tamalina; Luo, Yigang; Beck, Gavin R.; Luke, Patrick P.; Sawicki, Grzegorz

    2016-01-01

    Background Matrix metalloproteinases (MMPs), particularly MMP-2 and MMP-9, play an important role in ischemic injury to the heart, yet it is not known if these MMPs are involved in the injury that occurs to the transplant kidney. We therefore studied the pharmacologic protection of transplant kidneys during machine cold perfusion. Methods Human kidney perfusates were analyzed for the presence of injury markers such as cytochrome c oxidase, lactate dehydrogenase, and neutrophil-gelatinase associated lipocalin (NGAL), and MMP-2 and MMP-9 were measured. The effects of MMP inhibitors MMP-2 siRNA and doxycycline were studied in an animal model of donation after circulatory determination of death (DCDD). Results Markers of injury were present in all analyzed perfusates, with higher levels seen in perfusates from human kidneys donated after controlled DCDD compared to brain death and in perfusate from kidneys with delayed graft function. When rat kidneys were perfused at 4°C for 22 hours with the addition of MMP inhibitors, this resulted in markedly reduced levels of MMP-2, MMP-9 and analyzed injury markers. Conclusions Based on our study, MMPs are involved in preservation injury and the supplementation of preservation solution with MMP inhibitors is a potential novel strategy in protecting the transplant kidney from preservation injury. PMID:27327879

  4. Epalrestat protects against diabetic peripheral neuropathy by alleviating oxidative stress and inhibiting polyol pathway

    PubMed Central

    Li, Qing-rong; Wang, Zhuo; Zhou, Wei; Fan, Shou-rui; Ma, Run; Xue, Li; Yang, Lu; Li, Ya-shan; Tan, Hong-li; Shao, Qing-hua; Yang, Hong-ying

    2016-01-01

    Epalrestat is a noncompetitive and reversible aldose reductase inhibitor used for the treatment of diabetic neuropathy. This study assumed that epalrestat had a protective effect on diabetic peripheral nerve injury by suppressing the expression of aldose reductase in peripheral nerves of diabetes mellitus rats. The high-fat and high-carbohydrate model rats were established by intraperitoneal injection of streptozotocin. Peripheral neuropathy occurred in these rats after sustaining high blood glucose for 8 weeks. At 12 weeks after streptozotocin injection, rats were intragastrically administered epalrestat 100 mg/kg daily for 6 weeks. Transmission electron microscope revealed that the injuries to myelinated nerve fibers, non-myelinated nerve fibers and Schwann cells of rat sciatic nerves had reduced compared to rats without epalrestat administuation. Western blot assay and immunohistochemical results demonstrated that after intervention with epalrestat, the activities of antioxidant enzymes such as superoxide dismutase, catalase and glutathione peroxidase gradually increased, but aldose reductase protein expression gradually diminished. Results confirmed that epalrestat could protect against diabetic peripheral neuropathy by relieving oxidative stress and suppressing the polyol pathway. PMID:27073391

  5. Coenzyme Q10 protects astrocytes from ROS-induced damage through inhibition of mitochondria-mediated cell death pathway.

    PubMed

    Jing, Li; He, Mao-Tao; Chang, Yue; Mehta, Suresh L; He, Qing-Ping; Zhang, Jian-Zhong; Li, P Andy

    2015-01-01

    Coenzyme Q10 (CoQ10) acts by scavenging reactive oxygen species to protect neuronal cells against oxidative stress in neurodegenerative diseases. The present study was designed to examine whether CoQ10 was capable of protecting astrocytes from reactive oxygen species (ROS) mediated damage. For this purpose, ultraviolet B (UVB) irradiation was used as a tool to induce ROS stress to cultured astrocytes. The cells were treated with 10 and 25 μg/ml of CoQ10 for 3 or 24 h prior to the cells being exposed to UVB irradiation and maintained for 24 h post UVB exposure. Cell viability was assessed by MTT conversion assay. Mitochondrial respiration was assessed by respirometer. While superoxide production and mitochondrial membrane potential were measured using fluorescent probes, levels of cytochrome C (cyto-c), cleaved caspase-9, and caspase-8 were detected using Western blotting and/or immunocytochemistry. The results showed that UVB irradiation decreased cell viability and this damaging effect was associated with superoxide accumulation, mitochondrial membrane potential hyperpolarization, mitochondrial respiration suppression, cyto-c release, and the activation of both caspase-9 and -8. Treatment with CoQ10 at two different concentrations started 24 h before UVB exposure significantly increased the cell viability. The protective effect of CoQ10 was associated with reduction in superoxide, normalization of mitochondrial membrane potential, improvement of mitochondrial respiration, inhibition of cyto-c release, suppression of caspase-9. Furthermore, CoQ10 enhanced mitochondrial biogenesis. It is concluded that CoQ10 may protect astrocytes through suppression of oxidative stress, prevention of mitochondrial dysfunction, blockade of mitochondria-mediated cell death pathway, and enhancement of mitochondrial biogenesis. PMID:25552930

  6. A tetracycline derivative, minocycline, reduces inflammation and protects against focal cerebral ischemia with a wide therapeutic window

    PubMed Central

    Yrjänheikki, Juha; Tikka, Tiina; Keinänen, Riitta; Goldsteins, Gundars; Chan, Pak H.; Koistinaho, Jari

    1999-01-01

    The only treatment of patients with acute ischemic stroke is thrombolytic therapy, which benefits only a fraction of stroke patients. Both human and experimental studies indicate that ischemic stroke involves secondary inflammation that significantly contributes to the outcome after ischemic insult. Minocycline is a semisynthetic second-generation tetracycline that exerts antiinflammatory effects that are completely separate from its antimicrobial action. Because tetracycline treatment is clinically well tolerated, we investigated whether minocycline protects against focal brain ischemia with a wide therapeutic window. Using a rat model of transient middle cerebral artery occlusion, we show that daily treatment with minocycline reduces cortical infarction volume by 76 ± 22% when the treatment is started 12 h before ischemia and by 63 ± 35% when started even 4 h after the onset of ischemia. The treatment inhibits morphological activation of microglia in the area adjacent to the infarction, inhibits induction of IL-1β-converting enzyme, and reduces cyclooxygenase-2 expression and prostaglandin E2 production. Minocycline had no effect on astrogliosis or spreading depression, a wave of ionic transients thought to contribute to enlargement of cortical infarction. Treatment with minocycline may act directly on brain cells, because cultured primary neurons were also salvaged from glutamate toxicity. Minocycline may represent a prototype of an antiinflammatory compound that provides protection against ischemic stroke and has a clinically relevant therapeutic window. PMID:10557349

  7. Tanshinones inhibit amyloid aggregation by amyloid-β peptide, disaggregate amyloid fibrils, and protect cultured cells.

    PubMed

    Wang, Qiuming; Yu, Xiang; Patal, Kunal; Hu, Rundong; Chuang, Steven; Zhang, Ge; Zheng, Jie

    2013-06-19

    The misfolding and aggregation of amyloid-β (Aβ) peptides into amyloid fibrils is regarded as one of the causative events in the pathogenesis of Alzheimer's disease (AD). Tanshinones extracted from Chinese herb Danshen (Salvia Miltiorrhiza Bunge) were traditionally used as anti-inflammation and cerebrovascular drugs due to their antioxidation and antiacetylcholinesterase effects. A number of studies have suggested that tanshinones could protect neuronal cells. In this work, we examine the inhibitory activity of tanshinone I (TS1) and tanshinone IIA (TS2), the two major components in the Danshen herb, on the aggregation and toxicity of Aβ1-42 using atomic force microscopy (AFM), thioflavin-T (ThT) fluorescence assay, cell viability assay, and molecular dynamics (MD) simulations. AFM and ThT results show that both TS1 and TS2 exhibit different inhibitory abilities to prevent unseeded amyloid fibril formation and to disaggregate preformed amyloid fibrils, in which TS1 shows better inhibitory potency than TS2. Live/dead assay further confirms that introduction of a very small amount of tanshinones enables protection of cultured SH-SY5Y cells against Aβ-induced cell toxicity. Comparative MD simulation results reveal a general tanshinone binding mode to prevent Aβ peptide association, showing that both TS1 and TS2 preferentially bind to a hydrophobic β-sheet groove formed by the C-terminal residues of I31-M35 and M35-V39 and several aromatic residues. Meanwhile, the differences in binding distribution, residues, sites, population, and affinity between TS1-Aβ and TS2-Aβ systems also interpret different inhibitory effects on Aβ aggregation as observed by in vitro experiments. More importantly, due to nonspecific binding mode of tanshinones, it is expected that tanshinones would have a general inhibitory efficacy of a wide range of amyloid peptides. These findings suggest that tanshinones, particularly TS1 compound, offer promising lead compounds with dual

  8. Inhibiting an Epoxide Hydrolase Virulence Factor from Pseudomonas aeruginosa Protects CFTR.

    PubMed

    Bahl, Christopher D; Hvorecny, Kelli L; Bomberger, Jennifer M; Stanton, Bruce A; Hammock, Bruce D; Morisseau, Christophe; Madden, Dean R

    2015-08-17

    Opportunistic pathogens exploit diverse strategies to sabotage host defenses. Pseudomonas aeruginosa secretes the CFTR inhibitory factor Cif and thus triggers loss of CFTR, an ion channel required for airway mucociliary defense. However, the mechanism of action of Cif has remained unclear. It catalyzes epoxide hydrolysis, but there is no known role for natural epoxides in CFTR regulation. It was demonstrated that the hydrolase activity of Cif is strictly required for its effects on CFTR. A small-molecule inhibitor that protects this key component of the mucociliary defense system was also uncovered. These results provide a basis for targeting the distinctive virulence chemistry of Cif and suggest an unanticipated role of physiological epoxides in intracellular protein trafficking. PMID:26136396

  9. Puerarin protects brain tissue against cerebral ischemia/reperfusion injury by inhibiting the inflammatory response

    PubMed Central

    Zhou, Feng; Wang, Liang; Liu, Panpan; Hu, Weiwei; Zhu, Xiangdong; Shen, Hong; Yao, Yuanyuan

    2014-01-01

    Puerarin, a traditional Chinese medicine, exerts a powerful neuroprotective effect in cerebral ischemia/reperfusion injury, but its mechanism is unknown. Here, we established rat models of middle cerebral artery ischemia/reperfusion injury using the suture method. Puerarin (100 mg/kg) was administered intraperitoneally 30 minutes before middle cerebral artery occlusion and 8 hours after reperfusion. Twenty-four hours after reperfusion, we found that puerarin significantly improved neurological deficit, reduced infarct size and brain water content, and notably diminished the expression of Toll-like receptor-4, myeloid differentiation factor 88, nuclear factor kappa B and tumor necrosis factor-α in the ischemic region. These data indicate that puerarin exerts an anti-inflammatory protective effect on brain tissue with ischemia/reperfusion damage by downregulating the expression of multiple inflammatory factors. PMID:25657724

  10. Inhibition of protein kinase G activity protects neonatal mouse respiratory network from hyperthermic and hypoxic stress.

    PubMed

    Armstrong, Gary A B; López-Guerrero, Juan J; Dawson-Scully, Ken; Peña, Fernando; Robertson, R Meldrum

    2010-01-22

    In spite of considerable research attention focused on clarifying the mechanisms by which the mammalian respiratory rhythm is generated, little attention has been given to examining how this neuronal circuit can be protected from heat stress. Hyperthermia has a profound effect on neuronal circuits including the circuit that generates breathing in mammals. As temperature of the brainstem increases, respiratory frequency concomitantly rises. If temperature continues to increase respiratory arrest (apnea) and death can occur. Previous research has implicated protein kinase G (PKG) activity in regulating neuronal thermosensitivity of neuronal circuits in invertebrates. Here we examine if pharmacological manipulation of PKG activity in a brainstem slice preparation could alter the thermosensitivity of the fictive neonatal mouse respiratory rhythm. We report a striking effect following alteration of PKG activity in the brainstem such that slices treated with the PKG inhibitor KT5823 recovered fictive respiratory rhythm generation significantly faster than control slices and slices treated with a PKG activator (8-Br-cGMP). Furthermore, slices treated with 8-Br-cGMP arrested fictive respiration at a significantly lower temperature than all other treatment groups. In a separate set of experiments we examined if altered PKG activity could regulate the response of slices to hypoxia by altering the protective switch to fictive gasping. Slices treated with 8-Br-cGMP did not switch to the fictive gasp-like pattern following exposure to hypoxia whereas slices treated with KT5823 did display fictive gasping. We propose that PKG activity inversely regulates the amount of stress the neonatal mammalian respiratory rhythm can endure. PMID:19945442

  11. Epigallocatechin-3-gallate protects against cisplatin-induced nephrotoxicity by inhibiting endoplasmic reticulum stress-induced apoptosis

    PubMed Central

    Chen, Binbin; Liu, Guangyi; Zou, Peimei; Li, Xing; Hao, Qiufa; Jiang, Bei; Yang, Xiangdong

    2015-01-01

    Cisplatin (CP)-induced nephrotoxicity hampers its application in clinic. Green tea, particularly its predominant polyphenolic constituent epigallocatechin-3-gallate (EGCG), possesses anti-inflammatory, antioxidant, and anti-apoptotic properties. The present study was designed to investigate the protective effects of EGCG against CP-induced nephrotoxicity in mice. Male C57/BL6 mice in different groups received single injection of CP (20 mg/kg) and EGCG (100 mg/kg) in various sets and kidney tissues and blood were collected after killing. Then, samples were used for biochemical and immunohistochemical assay. Our results showed EGCG decreased biochemical factors and immunohistochemical damage induced by CP. Besides, expression of phosphorylated-extracellular signal-regulated kinase (p-ERK), glucose-regulated protein 78 (GRP78), caspase-12, and apoptosis of kidney were decreased by EGCG via inhibition of endoplasmic reticulum (ER) stress-induced apoptosis. PMID:25716017

  12. C-phycocyanin protects against low fertility by inhibiting reactive oxygen species in aging mice

    PubMed Central

    Li, Yan-Jiao; Han, Zhe; Ge, Lei; Zhou, Cheng-Jie; Zhao, Yue-Fang; Wang, Dong-Hui; Ren, Jing; Niu, Xin-Xin; Liang, Cheng-Guang

    2016-01-01

    Women over 35 have higher rates of infertility, largely due to deterioration of oocyte quality characterized by fragmentation, abnormal meiotic spindle-chromosome complexes, and oxidative stress. C-phycocyanin (PC) is a biliprotein enriched in Spirulina platensis that is known to possess antioxidant, anti-inflammatory, and radical-scavenging properties. D-galactose-induced aging acceleration in mice has been extensively used to study aging mechanisms and for pharmaceutical screening. In this study, adult female B6D2F/1 mice injected with D-galactose were used as a model to test the age-reversing effects of PC on degenerated reproductive ability. Our results show that PC can prevent oocyte fragmentation and aneuploidy by maintaining cytoskeletal integrity. Moreover, PC can reverse the expression of antioxidant genes, increase superoxide dismutase (SOD) activity and decrease methane dicarboxylic aldehyde (MDA) content, and normalize mitochondria distribution. PC exerts its benefit by inhibiting reactive oxygen species (ROS) production, which decreases apoptosis. Finally, we observe a significant increase in litter size after PC administration to D-galactose-induced aging mice. Our study demonstrates for the first time that D-galactose-induced impaired female reproductive capability can be partially rescued by the antioxidant effects of PC. PMID:27008700

  13. C-phycocyanin protects against low fertility by inhibiting reactive oxygen species in aging mice.

    PubMed

    Li, Yan-Jiao; Han, Zhe; Ge, Lei; Zhou, Cheng-Jie; Zhao, Yue-Fang; Wang, Dong-Hui; Ren, Jing; Niu, Xin-Xin; Liang, Cheng-Guang

    2016-04-01

    Women over 35 have higher rates of infertility, largely due to deterioration of oocyte quality characterized by fragmentation, abnormal meiotic spindle-chromosome complexes, and oxidative stress. C-phycocyanin (PC) is a biliprotein enriched in Spirulina platensis that is known to possess antioxidant, anti-inflammatory, and radical-scavenging properties. D-galactose-induced aging acceleration in mice has been extensively used to study aging mechanisms and for pharmaceutical screening. In this study, adult female B6D2F/1 mice injected with D-galactose were used as a model to test the age-reversing effects of PC on degenerated reproductive ability. Our results show that PC can prevent oocyte fragmentation and aneuploidy by maintaining cytoskeletal integrity. Moreover, PC can reverse the expression of antioxidant genes, increase superoxide dismutase (SOD) activity and decrease methane dicarboxylic aldehyde (MDA) content, and normalize mitochondria distribution. PC exerts its benefit by inhibiting reactive oxygen species (ROS) production, which decreases apoptosis. Finally, we observe a significant increase in litter size after PC administration to D-galactose-induced aging mice. Our study demonstrates for the first time that D-galactose-induced impaired female reproductive capability can be partially rescued by the antioxidant effects of PC. PMID:27008700

  14. Inhibition of insulin/IGF-1 receptor signaling protects from mitochondria-mediated kidney failure.

    PubMed

    Ising, Christina; Koehler, Sybille; Brähler, Sebastian; Merkwirth, Carsten; Höhne, Martin; Baris, Olivier R; Hagmann, Henning; Kann, Martin; Fabretti, Francesca; Dafinger, Claudia; Bloch, Wilhelm; Schermer, Bernhard; Linkermann, Andreas; Brüning, Jens C; Kurschat, Christine E; Müller, Roman-Ulrich; Wiesner, Rudolf J; Langer, Thomas; Benzing, Thomas; Brinkkoetter, Paul Thomas

    2015-02-02

    Mitochondrial dysfunction and alterations in energy metabolism have been implicated in a variety of human diseases. Mitochondrial fusion is essential for maintenance of mitochondrial function and requires the prohibitin ring complex subunit prohibitin-2 (PHB2) at the mitochondrial inner membrane. Here, we provide a link between PHB2 deficiency and hyperactive insulin/IGF-1 signaling. Deletion of PHB2 in podocytes of mice, terminally differentiated cells at the kidney filtration barrier, caused progressive proteinuria, kidney failure, and death of the animals and resulted in hyperphosphorylation of S6 ribosomal protein (S6RP), a known mediator of the mTOR signaling pathway. Inhibition of the insulin/IGF-1 signaling system through genetic deletion of the insulin receptor alone or in combination with the IGF-1 receptor or treatment with rapamycin prevented hyperphosphorylation of S6RP without affecting the mitochondrial structural defect, alleviated renal disease, and delayed the onset of kidney failure in PHB2-deficient animals. Evidently, perturbation of insulin/IGF-1 receptor signaling contributes to tissue damage in mitochondrial disease, which may allow therapeutic intervention against a wide spectrum of diseases.

  15. Quercitrin offers protection against brain injury in mice by inhibiting oxidative stress and inflammation.

    PubMed

    Ma, Jie-Qiong; Luo, Rong-Zhen; Jiang, Hai-Xia; Liu, Chan-Min

    2016-01-01

    Quercitrin is one of the primary flavonoid compounds present in vegetables and fruits. The aim of the present study was to evaluate the effects of quercitrin against carbon tetrachloride (CCl4) induced brain injury and further to elucidate its probable mechanisms. ICR mice received CCl4 intraperitoneally with or without quercitrin co-administration for 4 weeks. Our data showed that quercitrin significantly suppressed the elevation of reactive oxygen species (ROS) production and malondialdehyde (MDA) content, reduced tissue plasminogen activator (t-PA) activity, enhanced the antioxidant enzyme activities and abrogated cytochrome P450 2E1 (CYP2E1) induction in mouse brains. Quercitrin also prevented CCl4 induced cerebral function disorders associated with its ability to inhibit the activities of monoamine oxidase (MAO), acetylcholine esterase (AChE) and the N-methyl-d-aspartate receptor 2B subunit (NR2B). In addition, western blot analysis showed that quercitrin suppressed the release of pro-inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6). Taken together, our findings suggested that quercitrin may be a potential candidate to be developed as a neuroprotective agent.

  16. Radiofrequency Renal Denervation Protects the Ischemic Heart via Inhibition of GRK2 and Increased Nitric Oxide Signaling

    PubMed Central

    Polhemus, David J.; Gao, Juan; Scarborough, Amy L.; Trivedi, Rishi; McDonough, Kathleen H.; Goodchild, Traci T.; Smart, Frank

    2016-01-01

    Rationale: Catheter-based renal denervation (RDN) is currently under development for the treatment of resistant hypertension and is thought to reduce blood pressure via interruption of sympathetic pathways that modulate cardiovascular function. The sympathetic nervous system also plays a critical role in the pathogenesis of acute myocardial infarction and heart failure. Objective: We examined whether treatment with radiofrequency (RF)-RDN would protect the heart against subsequent myocardial ischemia/reperfusion injury via direct effects on the myocardium. Methods and Results: Spontaneously hypertensive rats received either bilateral RF-RDN or sham-RDN. At 4 weeks after RF-RDN (n=14) or sham-RDN (n=14) treatment, spontaneously hypertensive rats were subjected to 30 minutes of transient coronary artery occlusion and 24 hours –7 days reperfusion. Four weeks after RF-RDN, myocardial oxidative stress was markedly attenuated, and transcription and translation of antioxidants, superoxide dismutase 1 and glutathione peroxidase-1, were significantly upregulated compared with sham-RDN spontaneously hypertensive rats. RF-RDN also inhibited myocardial G protein–coupled receptor kinase 2 pathological signaling and enhanced myocardial endothelial nitric oxide synthase function and nitric oxide signaling. RF-RDN therapy resulted in a significant reduction in myocardial infarct size per area at risk compared with sham-RDN (26.8 versus 43.9%; P<0.01) at 24 hours postreperfusion and significantly improved left ventricular function at 7 days after myocardial ischemia/reperfusion. Conclusions: RF-RDN reduced oxidative stress, inhibited G protein–coupled receptor kinase 2 signaling, increased nitric oxide bioavailability, and ameliorated myocardial reperfusion injury in the setting of severe hypertension. These findings provide new insights into the remote cardioprotective effects of RF-RDN acting directly on cardiac myocytes to attenuate cell death and protect against ischemic

  17. Mdm2 inhibition confers protection of p53-proficient cells from the cytotoxic effects of Wee1 inhibitors.

    PubMed

    Li, Yizhu; Saini, Priyanka; Sriraman, Anusha; Dobbelstein, Matthias

    2015-10-20

    Pharmacological inhibition of the cell cycle regulatory kinase Wee1 represents a promising strategy to eliminate cancer cells. Wee1 inhibitors cooperate with chemotherapeutics, e. g. nucleoside analogues, pushing malignant cells from S phase towards premature mitosis and death. However, considerable toxicities are observed in preclinical and clinical trials. A high proportion of tumor cells can be distinguished from all other cells of a patient's body by inactivating mutations in the tumor suppressor p53. Here we set out to develop an approach for the selective protection of p53-proficient cells against the cytotoxic effects of Wee1 inhibitors. We pretreated such cells with Nutlin-3a, a prototype inhibitor of the p53-antagonist Mdm2. The resulting transient cell cycle arrest effectively increased the survival of cells that were subsequently treated with combinations of the Wee1 inhibitor MK-1775 and/or the nucleoside analogue gemcitabine. In this constellation, Nutlin-3a reduced caspase activation and diminished the phosphorylation of Histone 2AX, an indicator of the DNA damage response. Both effects were strictly dependent on the presence of p53. Moreover, Nutlin pre-treatment reduced the fraction of cells that were undergoing premature mitosis in response to Wee1 inhibition. We conclude that the pre-activation of p53 through Mdm2 antagonists serves as a viable option to selectively protect p53-proficient cells against the cytotoxic effects of Wee1 inhibitors, especially when combined with a nucleoside analogue. Thus, Mdm2 antagonists might prove useful to avoid unwanted side effects of Wee1 inhibitors. On the other hand, when a tumor contains wild type p53, care should be taken not to induce its activity before applying Wee1 inhibitors. PMID:26431163

  18. Mdm2 inhibition confers protection of p53-proficient cells from the cytotoxic effects of Wee1 inhibitors

    PubMed Central

    Dobbelstein, Matthias

    2015-01-01

    Pharmacological inhibition of the cell cycle regulatory kinase Wee1 represents a promising strategy to eliminate cancer cells. Wee1 inhibitors cooperate with chemotherapeutics, e. g. nucleoside analogues, pushing malignant cells from S phase towards premature mitosis and death. However, considerable toxicities are observed in preclinical and clinical trials. A high proportion of tumor cells can be distinguished from all other cells of a patient's body by inactivating mutations in the tumor suppressor p53. Here we set out to develop an approach for the selective protection of p53-proficient cells against the cytotoxic effects of Wee1 inhibitors. We pretreated such cells with Nutlin-3a, a prototype inhibitor of the p53-antagonist Mdm2. The resulting transient cell cycle arrest effectively increased the survival of cells that were subsequently treated with combinations of the Wee1 inhibitor MK-1775 and/or the nucleoside analogue gemcitabine. In this constellation, Nutlin-3a reduced caspase activation and diminished the phosphorylation of Histone 2AX, an indicator of the DNA damage response. Both effects were strictly dependent on the presence of p53. Moreover, Nutlin pre-treatment reduced the fraction of cells that were undergoing premature mitosis in response to Wee1 inhibition. We conclude that the pre-activation of p53 through Mdm2 antagonists serves as a viable option to selectively protect p53-proficient cells against the cytotoxic effects of Wee1 inhibitors, especially when combined with a nucleoside analogue. Thus, Mdm2 antagonists might prove useful to avoid unwanted side effects of Wee1 inhibitors. On the other hand, when a tumor contains wild type p53, care should be taken not to induce its activity before applying Wee1 inhibitors. PMID:26431163

  19. Protective Effect of Thymoquinone against Cyclophosphamide-Induced Hemorrhagic Cystitis through Inhibiting DNA Damage and Upregulation of Nrf2 Expression.

    PubMed

    Gore, Prashant R; Prajapati, Chaitali P; Mahajan, Umesh B; Goyal, Sameer N; Belemkar, Sateesh; Ojha, Shreesh; Patil, Chandragouda R

    2016-01-01

    Cyclophosphamide (CYP) induced hemorrhagic cystitis is a dose-limiting side effect involving increased oxidative stress, inflammatory cytokines and suppressed activity of nuclear factor related erythroid 2-related factor (Nrf2). Thymoquinone (TQ), an active constituent of Nigella sativa seeds, is reported to increase the expression of Nrf2, exert antioxidant action, and anti-inflammatory effects in the experimental animals. The present study was designed to explore the effects of TQ on CYP-induced hemorrhagic cystitis in Balb/c mice. Cystitis was induced by a single intraperitoneal injection of CYP (200 mg/kg). TQ was administered intraperitoneally at 5, 10 and 20 mg/kg doses twice a day, for three days before and three days after the CYP administration. The efficacy of TQ was determined in terms of the protection against the CYP-induced histological perturbations in the bladder tissue, reduction in the oxidative stress, and inhibition of the DNA fragmentation. Immunohistochemistry was performed to examine the expression of Nrf2. TQ protected against CYP-induced oxidative stress was evident from significant reduction in the lipid peroxidation, restoration of the levels of reduced glutathione, catalase and superoxide dismutase activities. TQ treatment significantly reduced the DNA damage evident as reduced DNA fragmentation. A significant decrease in the cellular infiltration, edema, epithelial denudation and hemorrhage were observed in the histological observations. There was restoration and rise in the Nrf2 expression in the bladder tissues of mice treated with TQ. These results confirm that, TQ ameliorates the CYP-induced hemorrhagic cystitis in mice through reduction in the oxidative stress, inhibition of the DNA damage and through increased expression of Nrf2 in the bladder tissues. PMID:27489498

  20. Protective Effect of Thymoquinone against Cyclophosphamide-Induced Hemorrhagic Cystitis through Inhibiting DNA Damage and Upregulation of Nrf2 Expression

    PubMed Central

    Gore, Prashant R.; Prajapati, Chaitali P.; Mahajan, Umesh B.; Goyal, Sameer N.; Belemkar, Sateesh; Ojha, Shreesh; Patil, Chandragouda R.

    2016-01-01

    Cyclophosphamide (CYP) induced hemorrhagic cystitis is a dose-limiting side effect involving increased oxidative stress, inflammatory cytokines and suppressed activity of nuclear factor related erythroid 2-related factor (Nrf2). Thymoquinone (TQ), an active constituent of Nigella sativa seeds, is reported to increase the expression of Nrf2, exert antioxidant action, and anti-inflammatory effects in the experimental animals. The present study was designed to explore the effects of TQ on CYP-induced hemorrhagic cystitis in Balb/c mice. Cystitis was induced by a single intraperitoneal injection of CYP (200 mg/kg). TQ was administered intraperitoneally at 5, 10 and 20 mg/kg doses twice a day, for three days before and three days after the CYP administration. The efficacy of TQ was determined in terms of the protection against the CYP-induced histological perturbations in the bladder tissue, reduction in the oxidative stress, and inhibition of the DNA fragmentation. Immunohistochemistry was performed to examine the expression of Nrf2. TQ protected against CYP-induced oxidative stress was evident from significant reduction in the lipid peroxidation, restoration of the levels of reduced glutathione, catalase and superoxide dismutase activities. TQ treatment significantly reduced the DNA damage evident as reduced DNA fragmentation. A significant decrease in the cellular infiltration, edema, epithelial denudation and hemorrhage were observed in the histological observations. There was restoration and rise in the Nrf2 expression in the bladder tissues of mice treated with TQ. These results confirm that, TQ ameliorates the CYP-induced hemorrhagic cystitis in mice through reduction in the oxidative stress, inhibition of the DNA damage and through increased expression of Nrf2 in the bladder tissues. PMID:27489498

  1. Rapamycin Protects from Type-I Peritoneal Membrane Failure Inhibiting the Angiogenesis, Lymphangiogenesis, and Endo-MT.

    PubMed

    González-Mateo, Guadalupe Tirma; Aguirre, Anna Rita; Loureiro, Jesús; Abensur, Hugo; Sandoval, Pilar; Sánchez-Tomero, José Antonio; del Peso, Gloria; Jiménez-Heffernan, José Antonio; Ruiz-Carpio, Vicente; Selgas, Rafael; López-Cabrera, Manuel; Aguilera, Abelardo; Liappas, Georgios

    2015-01-01

    Preservation of peritoneal membrane (PM) is essential for long-term survival in peritoneal dialysis (PD). Continuous presence of PD fluids (PDF) in the peritoneal cavity generates chronic inflammation and promotes changes of the PM, such as fibrosis, angiogenesis, and lymphangiogenesis. Mesothelial-to-mesenchymal transition (MMT) and endothelial-to-mesenchymal transition (Endo-MT) seem to play a central role in this pathogenesis. We speculated that Rapamycin, a potent immunosuppressor, could be beneficial by regulating blood and lymphatic vessels proliferation. We demonstrate that mice undergoing a combined PD and Rapamycin treatment (PDF + Rapa group) presented a reduced PM thickness and lower number of submesothelial blood and lymphatic vessels, as well as decreased MMT and Endo-MT, comparing with their counterparts exposed to PD alone (PDF group). Peritoneal water transport in the PDF + Rapa group remained at control level, whereas PD effluent levels of VEGF, TGF-β, and TNF-α were lower than in the PDF group. Moreover, the treatment of mesothelial cells with Rapamycin in vitro significantly decreased VEGF synthesis and selectively inhibited the VEGF-C and VEGF-D release when compared with control cells. Thus, Rapamycin has a protective effect on PM in PD through an antifibrotic and antiproliferative effect on blood and lymphatic vessels. Moreover, it inhibits Endo-MT and, at least partially, MMT. PMID:26688823

  2. A cytosolic protein factor from the naked mole-rat activates proteasomes of other species and protects these from inhibition.

    PubMed

    Rodriguez, Karl A; Osmulski, Pawel A; Pierce, Anson; Weintraub, Susan T; Gaczynska, Maria; Buffenstein, Rochelle

    2014-11-01

    The naked mole-rat maintains robust proteostasis and high levels of proteasome-mediated proteolysis for most of its exceptional (~31years) life span. Here, we report that the highly active proteasome from the naked mole-rat liver resists attenuation by a diverse suite of proteasome-specific small molecule inhibitors. Moreover, mouse, human, and yeast proteasomes exposed to the proteasome-depleted, naked mole-rat cytosolic fractions, recapitulate the observed inhibition resistance, and mammalian proteasomes also show increased activity. Gel filtration coupled with mass spectrometry and atomic force microscopy indicates that these traits are supported by a protein factor that resides in the cytosol. This factor interacts with the proteasome and modulates its activity. Although Heat shock protein 72 kDa (HSP72) and Heat shock protein 40 kDa (Homolog of bacterial DNAJ1) (HSP40(Hdj1)) are among the constituents of this factor, the observed phenomenon, such as increasing peptidase activity and protecting against inhibition cannot be reconciled with any known chaperone functions. This novel function may contribute to the exceptional protein homeostasis in the naked mole-rat and allow it to successfully defy aging.

  3. Rapamycin Protects from Type-I Peritoneal Membrane Failure Inhibiting the Angiogenesis, Lymphangiogenesis, and Endo-MT

    PubMed Central

    Aguirre, Anna Rita; Loureiro, Jesús; Abensur, Hugo; Sandoval, Pilar; Sánchez-Tomero, José Antonio; del Peso, Gloria; Jiménez-Heffernan, José Antonio; Ruiz-Carpio, Vicente; Selgas, Rafael; López-Cabrera, Manuel; Aguilera, Abelardo; Liappas, Georgios

    2015-01-01

    Preservation of peritoneal membrane (PM) is essential for long-term survival in peritoneal dialysis (PD). Continuous presence of PD fluids (PDF) in the peritoneal cavity generates chronic inflammation and promotes changes of the PM, such as fibrosis, angiogenesis, and lymphangiogenesis. Mesothelial-to-mesenchymal transition (MMT) and endothelial-to-mesenchymal transition (Endo-MT) seem to play a central role in this pathogenesis. We speculated that Rapamycin, a potent immunosuppressor, could be beneficial by regulating blood and lymphatic vessels proliferation. We demonstrate that mice undergoing a combined PD and Rapamycin treatment (PDF + Rapa group) presented a reduced PM thickness and lower number of submesothelial blood and lymphatic vessels, as well as decreased MMT and Endo-MT, comparing with their counterparts exposed to PD alone (PDF group). Peritoneal water transport in the PDF + Rapa group remained at control level, whereas PD effluent levels of VEGF, TGF-β, and TNF-α were lower than in the PDF group. Moreover, the treatment of mesothelial cells with Rapamycin in vitro significantly decreased VEGF synthesis and selectively inhibited the VEGF-C and VEGF-D release when compared with control cells. Thus, Rapamycin has a protective effect on PM in PD through an antifibrotic and antiproliferative effect on blood and lymphatic vessels. Moreover, it inhibits Endo-MT and, at least partially, MMT. PMID:26688823

  4. Adjudin protects against cerebral ischemia reperfusion injury by inhibition of neuroinflammation and blood-brain barrier disruption

    PubMed Central

    2014-01-01

    Neuroinflammation mediated by activation of microglia and interruption of the blood-brain barrier (BBB) is an important factor that contributes to neuron death and infarct area diffusion in ischemia reperfusion injury. Finding novel molecules to regulate neuroinflammation is of significant clinical value. We have previously shown that adjudin, a small molecule compound known to possess antispermatogenic function, attenuates microglia activation by suppression of the NF-κB pathway. In this study we continued to explore whether adjudin could be neuroprotective by using the transient middle cerebral artery occlusion (tMCAO) model. Adjudin treatment after reperfusion significantly decreased the infarction volume and neuroscore compared to the vehicle group. Staining of CD11b showed that adjudin markedly inhibited microglial activation in both the cortex and the striatum, accompanied by a reduction in the expression and release of cytokines TNF-α, IL-1β and IL-6. Concomitantly, adjudin noticeably prevented BBB disruption after ischemia and reperfusion, as indicated by the reduction of IgG detection in the brain cortex and striatum versus the vehicle group. This finding was also corroborated by immunofluorescence staining and immunoblotting of tight junction-related proteins ZO-1, JAM-A and Occludin, where the reduction of these proteins could be attenuated by adjudin treatment. Moreover, adjudin obviously inhibited the elevated MMP-9 activity after stroke. Together these data demonstrate that adjudin protects against cerebral ischemia reperfusion injury, and we present an effective neuroinflammation modulator with clinical potential. PMID:24927761

  5. Metalloproteinase Inhibition Protects against Reductions in Circulating Adrenomedullin during Lead-induced Acute Hypertension.

    PubMed

    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. PMID:25308714

  6. Lactoferrin protects against chemical-induced rat liver fibrosis by inhibiting stellate cell activation.

    PubMed

    Tung, Yu-Tang; Tang, Ting-Yu; Chen, Hsiao-Ling; Yang, Shang-Hsun; Chong, Kowit-Yu; Cheng, Winston T K; Chen, Chuan-Mu

    2014-01-01

    Liver diseases, which can be caused by alcohol abuse, chemical intoxication, viral hepatitis infection, and autoimmune disorders, are a significant health issue because they can develop into liver fibrosis and cirrhosis. Lactoferrin (LF), a siderophilic protein with 2 iron-binding sites, has been demonstrated to possess a multitude of biological functions, including antiinflammation, anticancer, and antimicrobial effects, as well as immunomodulatory-enhancing functions. In the current study, we induced hepatotoxicity in rats with dimethylnitrosamine (DMN) to establish a situation that would enable us to evaluate the hepatoprotective effects of LF against hepatic injury. Our results showed that DMN-induced hepatic pathological damage significantly decreased the body weight and liver index, increased the mRNA and protein levels of collagen α-1(I) (ColIα-1) and α-smooth muscle actin, and increased the hydroxyproline content. However, treatment with LF significantly increased body weight and liver index, decreased the mRNA and protein levels of ColIα-1 and α-smooth